JP2006003390A - Image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method by which oilless fixing at a low temperature can be performed, the occurrence of a mark of roll contact is suppressed and images with high glossiness can be formed. <P>SOLUTION: When an image is formed by the image forming method, including a fixing step of fixing a toner image formed using toner including a binder resin, a colorant and a release agent on a fixing substrate with a fixing device to form an image, and a discharge step of discharging the fixing substrate, on which the image has been formed to the outside of the fixing device by conveying the fixing substrate, in a state where a surface of the fixing substrate on which the image has been formed and a discharge roll are kept in contact with each other, the expressions (1): 10%≤Ha≤30%, (2): 10%≤Hb≤30%, and (3) 0.3%≤¾Ha-Hb¾≤8% are satisfied, wherein Ha represents the haze of an image area brought into contact with the discharge roll; and Hb represents the haze of an image area not brought into contact with the discharge roll. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming method for forming an image by transferring and fixing a toner image obtained by developing an electrostatic latent image formed by an electrophotographic method or an electrostatic recording method with a developer onto paper or the like.

A method for visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic charge image is formed on a photoreceptor by charging and exposure processes, the electrostatic latent image is developed with a developer containing toner, and visualized through transfer and fixing process steps.
As the developer used here, a two-component developer composed of a toner and a carrier and a one-component developer using a magnetic toner or a non-magnetic toner alone are known. As a method for producing these toners, a kneading and pulverizing method is generally used in which a thermoplastic resin is melt-kneaded together with a release agent such as a pigment, a charge control agent, and a wax, and after cooling, pulverized and classified. Further, if necessary, inorganic and organic fine particles may be added to the toner particle surface to improve fluidity and cleaning properties. These methods can produce very good toners, but have some problems as described below.

  First, in an ordinary kneading and pulverizing method, the shape of the toner is indeterminate, and the surface structure of the toner is easily pulverized at the interface of resin-release agent-pigment or the like during pulverization, and therefore is not uniform. Although it changes slightly depending on the pulverization property of the material used and the conditions of the pulverization process, it is difficult to control the toner shape and surface structure intentionally. In the kneading and pulverizing method, the range of material selection is limited. Specifically, the resin colorant dispersion must be sufficiently brittle and capable of being finely pulverized by an economically possible production apparatus.

  However, if the resin colorant dispersion is made brittle to satisfy these requirements, the resulting toner may further generate fine powder or change in toner shape due to mechanical shearing force applied in the developing machine. There is. Due to these effects, for example, in a two-component developer, the charging deterioration of the developer due to the adhesion of the fine powder to the carrier surface is accelerated, and in the one-component developer, toner scattering occurs due to the expansion of the particle size distribution. Deterioration in image quality is likely to occur due to a decrease in developability due to a change in shape.

  In addition, when a toner is formed by adding a large amount of a release agent such as wax, exposure to the release agent on the surface is often affected by the combination with a thermoplastic resin. In particular, in the case of a combination of a resin having increased elasticity due to a high molecular weight component and slightly pulverized resin and a brittle wax such as polyethylene, polyethylene is often exposed on the toner surface. Although this is advantageous for toner releasability at the time of fixing and cleaning of untransferred toner from the surface of the photoreceptor, since the polyethylene on the toner surface layer is easily transferred by mechanical force, the developing roll, photoreceptor and carrier are contaminated. Is likely to occur, leading to a decrease in reliability.

  Furthermore, due to the irregular shape of the toner, the flowability may not be sufficient even with the addition of a flow aid, and the mechanical shear force during use causes the fine particles to move to the concave portions of the toner surface over time. The flowability is lowered, and the flowability aid is buried in the toner, whereby developability, transferability, and cleaning properties are deteriorated. Further, when the toner collected by cleaning is returned to the developing machine and used again, the image quality is likely to further deteriorate. If the flow aid is further increased in order to prevent them, black spots are generated on the photoreceptor and the aid particles are scattered.

  In recent years, a toner production method using an emulsion polymerization aggregation method has been proposed as means for intentionally controlling the toner shape and surface structure (see, for example, Patent Documents 1 and 2). In this technique, a resin dispersion is generally prepared by emulsion polymerization or the like, while a colorant dispersion in which a colorant is dispersed in a solvent is prepared, and then these are mixed to form an aggregate corresponding to the toner particle size. This is a method for producing toner by fusing and coalescing by heating.

  Although this method can control the shape to some extent and improve the chargeability and durability, the internal structure is almost uniform, which may reduce the elution of the release agent component during fixing. However, there are problems in the deterioration of the oilless peelability of the fixing substrate and the stabilization of transparency in the image when output using an OHP film.

  On the other hand, in order to reduce the amount of energy used in copying machines and printers, a technology for fixing toner with lower energy is desired, and there is a strong demand for toner for electrophotography that can be fixed at a lower temperature. As a means for lowering the toner fixing temperature, a technique for lowering the glass transition point of a toner resin (binder resin) is generally performed. However, if the glass transition point is too low, powder aggregation is likely to occur (blocking), and the storage stability of the toner on the image is lost, so 50 ° C. is practically the lower limit.

  This glass transition point is a design point of many resin for toners currently on the market, and there is a problem that a toner capable of fixing at a low temperature cannot be obtained by the method of lowering the glass transition point. Further, for the purpose of preventing offset (see, for example, Patent Document 3) and pressure fixing (for example, see, for example, Patent Document 4), a technique using a crystalline resin as a binder resin for toner has been known for a long time. However, the toner containing these crystalline resins has a problem that the fixing performance to paper is not sufficient.

  As a crystalline resin that is expected to improve the fixability to paper, a polyester resin is exemplified, and a technique using the crystalline polyester resin for a toner has been proposed (for example, see Patent Document 5). This toner contains a non-crystalline polyester resin having a glass transition temperature of 40 ° C. or higher and a crystalline polyester resin having a melting point of 130 to 200 ° C. as a binder resin. However, this toner has excellent fine pulverization properties and blocking resistance. However, since the crystalline polyester resin has a high melting point, it has a problem in that it cannot achieve low-temperature fixability.

  In order to solve this problem, a technique using a toner in which a crystalline resin having a melting point of 110 ° C. or less and a non-crystalline resin is mixed has been proposed (for example, Patent Document 6). However, when an amorphous resin is mixed with a crystalline resin, there are practical problems such as a drop in the melting point of the toner, toner blocking, and deterioration in image storage stability. In addition, when the amount of the amorphous resin component is large, the characteristics of the amorphous resin component are largely reflected, so that it is difficult to lower the fixing temperature than the conventional one. For this reason, if a crystalline resin is used alone as a binder resin for toner, or if a non-crystalline resin is mixed in a very small amount, there is a problem in practical use.

Various techniques other than the above have been proposed as techniques using a crystalline polyester resin as a binder resin (see, for example, Patent Documents 7 to 9).
However, in these techniques, the crystalline polyester resin is a resin using alkylene glycol or alicyclic alcohol having a small number of carbon atoms with respect to the carboxylic acid component of terephthalic acid. Although these polyester resins are described as crystalline polyester resins in the above-mentioned document, they are substantially partially crystalline polyester resins, so the viscosity change with respect to the temperature of the toner (resin) is not steep, and the blocking property / Although there is no problem in image storability, stable peelability is not obtained.

  On the other hand, as a technique for achieving both blocking properties / image storage stability and low-temperature fixability, a toner containing a crystalline polyester resin having a crosslinked structure as a main component has been proposed (see Patent Document 10). However, in a developer using a toner having a crosslinked structure, particularly a two-component developer composed of a toner and a carrier, the charging characteristics are slightly insufficient, and the fixing latitude is not sufficient.

  In order to stabilize the peelability, it is necessary to make it easy to elute a release agent component such as Wax during fixing. Such securing of the elution property at the time of fixing has been realized conventionally by lowering the melting point of the release agent component or by reducing the molecular weight. However, although the elution property can be improved to some extent by the above method, the ratio of the low molecular weight component inevitably increases, and as a result, the binder resin component and the low molecular weight component of the release agent are compatible, and the toner itself The spinnability at the time of melting may deteriorate, and the hot offset property at high temperatures may deteriorate. Further, when the paper on which the image is formed by fixing is discharged to the outside of the apparatus, a contact mark is generated due to the contact between the image forming surface of the paper and the discharge roll, and it is difficult to obtain a high-quality image. . This is particularly noticeable when an image with a high glossiness is formed.

  On the other hand, a mold release agent using a metallocene catalyst has been proposed as a method for increasing the melting point and lowering the viscosity of the mold release agent (see Patent Document 11). However, the viscosity of the acid anhydride itself generally used as a copolymer is relatively high, and although it is certainly preferable for a high pressure and low speed fixing system such as two-roll fixing, an energy saving type fixing system (for example, patent In Document 12 etc., sufficient release of the release agent cannot be obtained, and as a result, a good quality image cannot be obtained.

  Furthermore, it has been proposed to use an ester release agent having low crystallinity in order to improve the transparency of roll contact marks and OHP images (see Patent Document 13). However, in this case, plasticity due to the compatibility between the binder resin component and the ester release agent occurs, so that the hot offset property in a high temperature range is likely to deteriorate. In order to cope with this, plasticity can be suppressed by a method such as introducing a crosslinked structure into the binder resin, and the transparency problem caused by the release agent can be improved to some extent. However, since the melt fluidity of the toner itself at the time of toner fixing becomes high, it becomes difficult to apply to the case of forming a high gloss image.

  As described above, in the electrophotographic process, in order to stably maintain the performance of the toner even under various mechanical stresses, the surface hardness can be maintained without suppressing the exposure of the release agent to the surface or the fixing property. In addition, it is necessary to improve the mechanical strength of the toner itself and to achieve both sufficient charging and fixing properties.

  In recent years, there has been a growing demand for higher image quality, and in particular in color image formation, there is a significant tendency for toner diameter to be reduced in order to achieve high-definition images. However, with the simple reduction in size while maintaining the conventional particle size distribution, the presence of fine powder side toner causes significant problems of carrier and photoconductor contamination and toner scattering, making it difficult to achieve high image quality and high reliability at the same time. It is. For this purpose, it is necessary that the particle size distribution can be sharpened and the particle size can be reduced.

Further, in recent years, in digital full-color copiers and printers, color image originals are separated by B (blue), R (red), and G (green) filters, and then a dot diameter of 20 to 70 μm corresponding to the original original is used. The latent image is developed using Y (yellow), M (magenta), C (cyan), and Bk (black) developers using the subtractive color mixing action.
Therefore, it is necessary to transfer a larger amount of developer than conventional black-and-white machines, and since it is necessary to cope with a small dot diameter, uniform chargeability, durability, toner strength, and sharpness of particle size distribution are increasing. It is becoming important.

In view of speeding up and energy saving of these machines, further low-temperature fixability of the toner is required. Also from these points, the agglomeration / fusion coalesced toner having a sharp particle size distribution and suitable for production of a small particle diameter has excellent characteristics.
On the other hand, for a toner mounted on a full-color machine, it is necessary to mix a large amount of toner sufficiently, and improvement of color reproducibility and OHP transparency at this time are essential.

  In general, a polyolefin-based wax is internally added to the release agent component for the purpose of preventing low-temperature offset during fixing. Along with this, a small amount of silicone oil is uniformly applied to the fixing roller to improve the high temperature offset property. For this reason, there is a problem that silicone oil adheres to the output transfer material that is output, and there is a sticky discomfort when handling it.

  Therefore, an oilless fixing toner in which a large amount of a release agent component is included in the toner has been proposed (see Patent Document 14). However, in this case, the releasability can be improved to some extent by adding a large amount of a release agent. However, since the binder resin component and the release agent are compatible, the release that elutes from the inside of the toner during fixing. The exudation of the form is not uniform and stable peelability is difficult to obtain. Further, since the means for controlling the cohesive force of the binder resin of the toner depends on the weight average molecular weight Mw of the binder resin and the glass transition temperature Tg, the spinnability and cohesiveness at the time of fixing the toner are directly controlled. It is difficult. Furthermore, the free component of the release agent may cause charging inhibition.

Further, when the image is fixed, a large amount of the release agent dissolves on the image to form a film, so that the pinch roll or discharge roll for discharging the paper on which the image is formed contacts the image forming surface of the paper. The image quality may be impaired due to contact marks (hereinafter, also referred to as “roll contact marks”) that are image defects caused by the image quality.
Japanese Patent Laid-Open No. 63-282275 JP-A-6-250439 Japanese Examined Patent Publication No.62-39428 Japanese Patent Publication No. 63-25335 Japanese Examined Patent Publication No.62-39428 Japanese Patent Publication No. 4-30014 Japanese Patent Laid-Open No. 4-120554 JP-A-4-239021 JP-A-5-165252 JP 2001-117268 A Japanese Patent Laid-Open No. 08-248671 JP 2001-75392 A JP-A-6-337541 JP-A-5-061239

  An object of the present invention is to solve the above problems. That is, an object of the present invention is to provide an image forming method capable of forming an image with high glossiness while being capable of oilless fixing at a low temperature, suppressing the occurrence of a roll contact mark.

  In order to achieve the above-mentioned problems, the present inventors have intensively studied about the process by which roll contact marks are generated when oilless fixing is performed using toner containing a release agent. At the same time, we examined the problems when dealing with low-temperature fixing.

Therefore, first, the present inventors examined a process of generating a roll contact mark. First, in the so-called oil-less fixing, a fixing substrate such as a paper on which a toner image formed with a toner containing a release agent such as wax is transferred, or a transparent sheet such as an OHP sheet is placed between a pair of fixing members. The toner is melted and pressed by passing through (abutting portion (nip portion) between the heating member and the pressure member) to fix the toner image on the surface of the fixing substrate.
Here, the contact time (passage time) between the fixing base material and the fixing member at the time of fixing is the contact width (nip width) of the nip portion in the direction in which the paper passes and the fixing base material passing through the nip portion. It can be obtained from the passing speed, and specifically can be obtained based on the following equation (1).
Formula (1) Contact time = nip width / fixed substrate nip passing speed.

  For example, when the nip width is 6 mm and the passing speed of the fixing substrate is 180 mm / second, the contact time is 6/180 = 0.0333 seconds. The contact time may be referred to as nip time, fixing time, or heating time.

The toner is melted by heating within this contact time, the viscosity decreases, and is fixed on the fixing substrate, but when obtaining a high gloss image, the viscosity of the toner is reduced within this contact time to form It is necessary to improve the smoothness of the image to be displayed.
On the other hand, when the viscosity is lowered, the cohesiveness of the binder resin constituting the toner is lowered, so that a part of the toner is transferred to the fixing member, and so-called hot offset occurs.

  In order to prevent this, a release agent such as wax is added, and the release agent is melted before the viscosity of the toner is excessively lowered by the contact time, and from inside the toner, between the toner image and the fixing member. A method of preventing the offset by improving the releasability of the toner image by causing the toner image to exude and widening the fixable region is common. For this reason, when a large amount of toner adheres to the fixing substrate as in a full-color image and a high gloss image is formed, a toner containing a large amount of a release agent is used. The release agent spreads over the entire surface.

  On the other hand, since the release agent usually has crystallinity, the viscosity rapidly decreases at a temperature equal to or higher than the melting point, thereby improving the releasability between the fixing member and the image formed on the fixing substrate. For this reason, after the fixing substrate passes through the nip portion, the heat used for fixing the toner image is dissipated in the air and / or to the fixing substrate, and when the image is cooled, the heat spreads on the image. The mold is crystallized again to form a layer made of a release agent (hereinafter sometimes referred to as “release agent layer”) on the image surface.

  Since a release agent generally contains many low molecular weight components, when fixing is performed using a toner containing a crystalline polyester resin and a release agent, immediately after fixing, the low molecular components of the release agent are: In addition to being compatible with the crystalline polyester resin, the fixing substrate is transferred to the surface of the discharge roll in the process of being discharged out of the machine by the discharge roll. For this reason, when the fixing substrate on which the image is formed by the discharge roll is discharged, the release agent once spread on the image surface adheres to the discharge roll, and the release agent layer exists on the image surface. Unevenness occurs in the

That is, since the surface smoothness is lost in the area where the image and the discharge roll abut compared to other areas, there is a difference in glossiness in the image forming surface of the fixing substrate, which is the roll contact. It is thought that it appears as a mark.
Therefore, the roll contact mark originally appears under the conditions for forming an image with a high glossiness, and when an image is formed under such conditions, it appears regardless of the fixing substrate used. .
For this reason, the present inventors considered that it is important to maintain the smoothness of the image surface even after the fixing substrate on which the image is formed is discharged out of the apparatus by the discharge roll.

  On the other hand, in order to cope with low-temperature fixing, it is common to use a crystalline resin as a binder resin component of the toner. However, the crystalline resin tends to promote the occurrence of a roll contact mark. Accordingly, the present inventors have the advantage of using a crystalline resin (low temperature fixability) in addition to maintaining the smoothness of the image surface after the fixing substrate is discharged out of the machine by the discharge roll. While securing, it was considered important to compensate for the demerit (deterioration of roll contact trace) using crystalline resin by some means.

Based on the above findings, the present inventors have found the following present invention. That is, the present invention
<1>
A fixing step in which a toner image formed using a toner containing at least a binder resin, a colorant, and a release agent is fixed on a fixing substrate by a fixing device to form an image;
A discharging step of discharging the fixing substrate on which the image has been formed to the outside of the fixing device by conveying at least a surface of the fixing substrate on which the image is formed and a discharge roll; In an image forming method including:
In the image forming method, the binder resin includes a crystalline resin, and the following formulas (2) to (4) are satisfied when an image is formed using a transparent sheet as the fixing base.
Formula (2) 10% ≦ Ha ≦ 30%
Formula (3) 10% ≦ Hb ≦ 30%
Formula (4) 0.3% ≦ | Ha−Hb | ≦ 8%
However, in the formulas (2) to (4), Ha represents the haze (cloudiness) of the area in contact with the discharge roll in the image forming area of the transparent sheet after the discharge step, and Hb The haze (cloudiness) of the area | region which did not contact | abut the said discharge roll in the image formation area of the said transparent sheet after passing through a discharge process is represented.

<2>
[1] The endothermic maximum value obtained from the differential thermal analysis of the release agent is in the range of 85 to 105 ° C., and [2] the ratio of the endothermic amount based on the endothermic peak area obtained by the differential thermal analysis ( The endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) is in the range of 5 to 15%, and [3] based on the maximum intensity of the endothermic peak. The image forming method according to <1>, wherein the required content of the release agent contained in the toner is in the range of 6 to 15% by weight.

<3>
In the toner, a coagulant is added to a mixed solution in which at least a resin fine particle dispersion in which crystalline resin fine particles of 1 μm or less are dispersed, a colorant dispersion, and a release agent dispersion are mixed to form aggregated particles. <1> or <2>, which is produced through an aggregation step to be formed and a fusion step in which the aggregated particles are heated to a melting point or higher of the crystalline resin fine particles to fuse and coalesce. This is an image forming method.

<4>
The viscosity ηs140 of the release agent at 140 ° C. measured using an E-type viscometer equipped with a cone plate with a cone angle of 1.34 ° is in the range of 1.5 to 5.0 mPa · s. The image forming method according to any one of <1> to <3>, wherein:

<5>
Any one of <1> to <4>, wherein the amount of the release agent present on the toner surface determined by X-ray photoelectron spectroscopy (XPS) is within a range of 11 to 40 atm%. The image forming method described in 1.

  As described above, according to the present invention, it is possible to provide an image forming method capable of oilless fixing at a low temperature, suppressing the occurrence of a roll contact mark, and forming a high gloss image. it can.

The image forming method of the present invention includes a fixing step in which a toner image formed using a toner containing at least a binder resin, a colorant, and a release agent is fixed on a fixing substrate by a fixing device to form an image. And a discharging step of discharging the fixing substrate on which the image has been formed to the outside of the fixing device by transporting at least a surface of the fixing substrate on which the image is formed and a discharging roll. And the binder resin contains a crystalline resin, and satisfies the following formulas (2) to (4) when an image is formed using a transparent sheet as the fixing substrate: And
Formula (2) 10% ≦ Ha ≦ 30%
Formula (3) 10% ≦ Hb ≦ 30%
Formula (4) 0.3% ≦ | Ha−Hb | ≦ 8%
However, in the formulas (2) to (4), Ha is a region in contact with the discharge roll in the image forming region of the transparent sheet after the discharge step (hereinafter abbreviated as “roll contact region”). Hb represents the haze (cloudiness) of the transparent sheet in the image forming area of the transparent sheet after the discharge process (hereinafter referred to as “roll non-contact area”). It may be abbreviated).

  Therefore, according to the present invention, it is possible to perform oilless fixing at a low temperature, to suppress the occurrence of a roll contact mark, and to form an image with high glossiness.

In the present invention, a transparent sheet (a so-called OHP sheet using V507 manufactured by Fuji Xerox Co., Ltd.) is used for the measurement of Ha and Hb, which are parameters defining the above formulas (2) to (4). Yes.
The reason for this is that the transparent sheet has a longer contact time with the fixing member than other fixing members such as paper in order to improve the transparency of the image formed on the transparent sheet as compared with other fixing substrates. This is because the roll contact mark is most likely to be generated most significantly because the temperature difference between the roll contact area and the roll non-contact area is large.
In addition, generally, the surface of the fixing substrate is smooth like a transparent sheet, and the paper with a higher basis weight is more likely to have a roll contact mark. That is, a smoother fixing substrate such as a transparent sheet is more likely to obtain a high glossiness, and at the same time, a difference in glossiness between the joint part and the non-joint part of the roll is likely to occur.

  In addition, the longer the contact time during fixing, the easier it is to obtain high glossiness, so the roll contact mark is likely to appear, and the roll contact mark is generated out of the nip width and the fixing substrate passing speed for controlling the contact time. It is the passing speed of the fixing substrate that tends to be a factor. This is presumably because the faster the passing speed is, the shorter the contact time with the discharge roll after the fixing substrate is released from the fixing member, and thus the difference in glossiness tends to occur.

As described above, when measuring Ha and Hb, a fixing base material (that is, a transparent sheet) that easily causes roll contact marks is used, and a transparent film is used so that roll contact marks are more likely to be generated. An image was formed with the fixing conditions set so that the contact time was about twice the normal fixing conditions.
For this reason, when an image can be formed on the transparent sheet under the conditions satisfying the formulas (2) to (4), the roll contact mark is surely formed even if another fixing base material such as paper other than the transparent sheet is used. Occurrence can be suppressed.

In the image forming method of the present invention, a crystalline resin is always used as a toner binder resin in order to cope with low-temperature fixing, and an amorphous resin can be used in combination as necessary. In this case, in order to sufficiently cope with low-temperature fixing, the ratio of the crystalline resin in the binder resin is preferably in the range of 75 to 100% by weight, and in the range of 85 to 100% by weight. Is more preferable.
When the ratio of the crystalline resin in the binder resin is less than 75% by weight, low-temperature fixing may be difficult.

  As described above, in the image forming method of the present invention, since the crystalline resin is used as the binder resin for the toner, low-temperature fixing is possible. Specifically, the fixing temperature is set in a temperature range of about 90 to 120 ° C. And can be fixed.

Various means for satisfying the above-described formulas (2) to (4) can be mentioned as described later, and the most suitable means is to use a release agent having a low low molecular weight component.
By using a release agent with a low low molecular weight component, when the fixing substrate on which the image is formed is discharged out of the machine by the discharge roll, the release agent once spread on the image surface is combined with the discharge roll. Since it can melt | dissolve and it can prevent that a mold release agent adheres to a roll, generation | occurrence | production of a roll contact | abutting trace can be suppressed and an image with high glossiness can be formed.
Moreover, by using such a release agent with a low low molecular weight component, the tendency that roll contact traces are likely to occur when a crystalline resin is used is counteracted, and roll contact traces are more reliably suppressed. be able to. The details of the release agent having a low low molecular weight component will be described later.

  The thickness of the release agent layer that covers the image surface after fixing is preferably in the range of 0.5 to 2.0 μm, and more preferably in the range of 0.8 to 1.5 μm. If the thickness of the release agent layer is less than 0.5 μm, stable peeling may not be obtained, and a high gloss image may not be obtained. Further, if the thickness is 2.0 μm or more, roll contact traces may be easily generated. The fixing conditions for measuring the thickness of the release agent layer will be described later.

  The thickness of the release agent layer can be obtained from SEM (scanning electron microscope) observation of the cross section of the image formed on the fixing substrate. Specifically, a portion of the fixing substrate on which the image is formed is cut, and a cross-sectional observation sample is prepared by depositing the obtained cross-sectional portion with gold or the like by a conventional method. In some cases, wax may be dyed with ruthenium or the like. The measurement of the sample for cross-sectional observation can be performed at a magnification that can be appropriately observed, but is preferably around 10,000 times. At the time of SEM observation, the cross section of the image part was observed at intervals of 3 μm in the paper surface direction, the thickness of the release agent layer at each measurement point was measured, and the average value was obtained.

  The thickness of the release agent layer covering the image surface is determined by the layer structure of toner particles used for image formation (for example, a so-called core shell structure provided with a core layer and a shell layer covering the core layer). By controlling the polarity, crosslinkability, etc. of the surface, it is possible to adjust to a desired value by controlling the release property of the release agent from the inside of the toner at the time of fixing.

<Toner and production method thereof>
Next, a constituent material of the toner used in the present invention, a manufacturing method thereof, and the like will be described. The toner used in the present invention is not particularly limited as long as it contains at least a binder resin, a colorant, and a release agent, and at least a crystalline resin is used as the binder resin. Agents can also be added. Moreover, although the manufacturing method can use a well-known method regardless of a wet method and a dry method, it is preferable to utilize wet methods, such as an emulsion polymerization aggregation method.
Hereinafter, the constituent material and the production method of the toner used in the present invention will be described on the assumption that the toner is produced mainly using an emulsion polymerization aggregation method. The toner production method used in the present invention is based on emulsion polymerization. The toner is not limited to the agglomeration method, and the toner constituent materials exemplified below can of course also be used when a toner is produced by another production method.

-Binder resin-
Since at least a crystalline resin is used as the binder resin for the toner, good low-temperature fixability can be ensured. In the present invention, the “crystalline resin” refers to a resin having a clear endothermic peak rather than a stepwise endothermic amount change in differential scanning calorimetry (DSC).
The toner binder resin used in the present invention uses only a crystalline resin or a crystalline resin as a main component in order to ensure low-temperature fixability. Amorphous resin can be used together. Below, the detail of crystalline resin is demonstrated.

  The number average molecular weight (Mn) of the crystalline resin is preferably 1500 or more, and more preferably 4000 or more. If the number average molecular weight (Mn) is less than 1500, the strength of the image against bending resistance may be reduced. In addition, when paper is used as the fixing substrate, toner may permeate into the surface of the fixing substrate (paper) at the time of fixing to cause uneven fixing.

  The crystalline resin is not particularly limited as long as it is a crystalline resin, and specific examples include crystalline polyester resins and crystalline vinyl resins. From the viewpoint of adjusting the melting point within a preferable range, a crystalline polyester resin is preferable. An aliphatic crystalline polyester resin having an appropriate melting point is more preferable.

Examples of the crystalline vinyl resin include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, and decyl (meth) acrylate. , Undecyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, oleyl (meth) acrylate, behenyl (meth) acrylate, etc. And vinyl resins using long-chain alkyl and alkenyl (meth) acrylic acid esters.
In the present specification, the description “(meth) acryl” means that both “acryl” and “methacryl” are included.

On the other hand, the crystalline polyester resin may be referred to as an acid (dicarboxylic acid) component (hereinafter sometimes referred to as “acid-derived constituent component”) and an alcohol (diol) component (hereinafter referred to as “alcohol-derived constituent component”). A).
Hereinafter, the acid-derived constituent component and the alcohol-derived constituent component will be described in more detail. In the present invention, a copolymer obtained by copolymerizing other components in a proportion of 50% by mass or less with respect to the crystalline polyester main chain is also a crystalline polyester.

-Acid-derived components-
The acid-derived constituent component is preferably an aliphatic dicarboxylic acid, and particularly preferably a linear carboxylic acid.
For example, succinic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid Acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc., or lower alkyl esters thereof Acid anhydrides can be mentioned but are not limited to these.

As the acid-derived constituent component, in addition to the above-mentioned aliphatic dicarboxylic acid-derived constituent component, constituent components such as a dicarboxylic acid-derived constituent component having a double bond and a dicarboxylic acid-derived constituent component having a sulfonic acid group are included. It is preferable.
The component derived from a dicarboxylic acid having a double bond is derived from a lower alkyl ester or acid anhydride of a dicarboxylic acid having a double bond, in addition to a component derived from a dicarboxylic acid having a double bond. Components are also included. The dicarboxylic acid-derived component having a sulfonic acid group is derived from a dicarboxylic acid having a sulfonic acid group, a lower alkyl ester of a dicarboxylic acid having a sulfonic acid group, or an acid anhydride. Components are also included.

  The dicarboxylic acid having a double bond can be suitably used to prevent hot offset at the time of fixing because the entire resin can be crosslinked using the double bond. Examples of such dicarboxylic acids include, but are not limited to, fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, fumaric acid, maleic acid and the like are preferable in terms of cost.

  The dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Further, if a sulfonic acid group is present when the entire resin is emulsified or suspended in water to produce fine particles, it can be emulsified or suspended without using a surfactant, as will be described later. Examples of the dicarboxylic acid having a sulfonic acid group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, 5-sulfoisophthalic acid sodium salt and the like are preferable in terms of cost.

  The content of acid-derived components other than these aliphatic dicarboxylic acid-derived components (dicarboxylic acid-derived component having a double bond and / or dicarboxylic acid-derived component having a sulfonic acid group) in the acid-derived component Is preferably 1 to 20 mol%, more preferably 2 to 10 mol%.

  When the content is less than 1 component mol%, pigment dispersion may not be good, the emulsified particle diameter may be large, and adjustment of the toner diameter by aggregation may be difficult. On the other hand, if it exceeds 20 component mol%, the crystallinity of the polyester resin is lowered, the melting point is lowered, the image storage stability is deteriorated, or the emulsion particle size is too small to dissolve in water, and no latex is produced. There is a case. In the present invention, “constituent mol%” refers to the percentage when each constituent component (acid-derived constituent component, alcohol-derived constituent component) in the polyester resin is 1 unit (mol).

-Alcohol-derived components-
The alcohol component is preferably an aliphatic diol, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol and the like are exemplified, but not limited thereto.

  The alcohol-derived constituent component preferably has an aliphatic diol-derived constituent component content of 80 constituent mol% or more, and includes other components as necessary. As the alcohol-derived constituent component, the content of the aliphatic diol-derived constituent component is more preferably 90 constituent mol% or more.

  When the content is less than 80 mol%, the crystallinity of the polyester resin is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability and low-temperature fixability may be deteriorated. On the other hand, examples of other components included as necessary include components such as a diol-derived component having a double bond and a diol-derived component having a sulfonic acid group.

  Examples of the diol having a double bond include 2-butene-1,4-diol, 3-butene-1,6-diol, 4-butene-1,8-diol and the like. On the other hand, as the diol having a sulfonic acid group, 1,4-dihydroxy-2-sulfonic acid benzene sodium salt, 1,3-dihydroxymethyl-5-sulfonic acid benzene sodium salt, 2-sulfo-1,4-butane Examples include diol sodium salt.

  Alcohol-derived components in the case of adding alcohol-derived components other than these linear aliphatic diol-derived components (diol-derived component having a double bond and / or diol-derived component having a sulfonic acid group) As content in a component, 1-20 structural mol% is preferable and 2-10 structural mol% is more preferable. When the content is less than 1 constituent mol%, pigment dispersion may be poor, the emulsified particle diameter may be large, and adjustment of the toner diameter by aggregation may be difficult. On the other hand, if it exceeds 20 component mol%, the crystallinity of the polyester resin is lowered, the melting point is lowered, the image storage stability is deteriorated, or the emulsion particle size is too small to dissolve in water, and no latex is produced. There is a case.

Further, the crystalline polyester resin preferably has an ester concentration M defined by the following formula (5) of 0.01 or more and 0.2 or less.
Formula (5) M = K / A
In the formula (5), M represents the ester concentration, K represents the number of ester groups in the crystalline polyester resin, and A represents the number of atoms constituting the polymer chain of the crystalline polyester resin.

  Here, the “ester concentration M” is one index indicating the content ratio of the ester group in the crystalline polyester resin. The “number of ester groups in the crystalline polyester resin” represented by K in the formula (5) refers to the number of ester bonds contained in the entire crystalline polyester resin molecule.

  The “number of atoms constituting the polymer chain of the crystalline polyester resin” represented by A in the above formula is the total number of atoms constituting the polymer chain of the crystalline polyester resin molecule, and is an atom involved in the ester bond All numbers are included, but do not include the number of atoms of branched parts in other constituent parts. That is, carbon atoms and oxygen atoms derived from carboxyl groups and alcohol groups involved in ester bonds (two oxygen atoms in one ester bond) and the six carbons constituting the polymer chain, for example, in the aromatic ring, Although included in the calculation of the number of atoms, for example, a hydrogen atom in an aromatic ring or an alkyl group, or an atom or atomic group of a substituent thereof constituting the polymer chain is not included in the calculation of the number of atoms.

  Explaining with a specific example, among the total of 10 atoms of 6 carbon atoms and 4 hydrogen atoms in the arylene group constituting the polymer chain, “the number of atoms constituting the polymer chain of the crystalline polyester resin” What is included in “A” is only six carbon atoms, and even if the hydrogen is substituted by any substituent, the atoms constituting the substituent are the above-mentioned “polymer of crystalline polyester resin”. It is not included in the number of atoms A ”constituting the chain.

The crystalline polyester resin has one repeating unit (for example, when the polymer is represented by H— [OCOR ₁ COOR ₂ O—] n—H, the one repeating unit is represented in []). In the case of a single polymer consisting of only two ester bonds in one repeating unit (that is, the number of ester groups K ′ = 2 in the repeating unit), the ester concentration M in this case is The following equation (6) can be obtained.
Formula (6) M = 2 / A ′
In formula (6), M represents the ester concentration, and A ′ represents the number of atoms constituting the polymer chain in one repeating unit.

Further, when the crystalline polyester resin is a copolymer composed of a plurality of copolymerized units, the number of ester groups KX and the number of atoms AX constituting the polymer chain are obtained for each copolymerized unit, and the copolymerization ratio is obtained. Can be obtained by summing each of them and substituting them into equation (5).
For example, a compound [(Xa) a (Xb) b (Xc)] having three copolymerized units of Xa, Xb and Xc and a copolymerization ratio of a: b: c (where a + b + c = 1) The ester concentration M for c] can be determined by the following equation (7).
Formula (7) M = {KXa × a + KXb × b + KXc × c} / {AXa × a + AXb × b + AXc × c}
In the formula (7), M represents an ester concentration, KXa represents a copolymer unit Xa, KXb represents a copolymer unit Xb, KXc represents the number of each ester group in the copolymer unit Xc, AXa represents a copolymer unit Xa, AXb represents the copolymer unit Xb, and AXc represents the number of atoms constituting each polymer chain in the copolymer unit Xc.

  When a crystalline polyester resin is used as the binder resin of the toner used in the present invention, the ester concentration M defined by the formulas (5) to (7) is set within the range of 0.01 to 0.2. As a result, the adhesion of the toner to the fixing substrate during fixing can be further enhanced.

  The method for producing the polyester resin is not particularly limited and can be produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification methods. Produced separately depending on the type of monomer. The molar ratio (acid component / alcohol component) when the acid component reacts with the alcohol component varies depending on the reaction conditions and the like, and cannot be generally stated, but is usually about 1/1.

  The production of the polyester resin can be carried out at a polymerization temperature of 180 to 230 ° C., and the reaction system is reacted under reduced pressure as necessary to remove water and alcohol generated during condensation. When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. In the case where a monomer having poor compatibility exists in the copolymerization reaction, it is preferable that the monomer having poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

  Catalysts usable in the production of the polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metal compounds such as zinc, manganese, antimony, titanium, tin, zirconium and germanium. A phosphorous acid compound, a phosphoric acid compound, an amine compound, etc., specifically, the following compounds are mentioned.

  For example, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxide, titanium Tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetrabutoxide, naphthene Zirconate, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octylate, germanium oxide, triphenyl Phosphite, tris (2,4-di -t- butyl-phenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

  In the present invention, the melting point of the crystalline resin is measured by using a differential scanning calorimeter (DSC) and measured at a rate of temperature increase of 10 ° C./min from room temperature to 150 ° C. It can be obtained as the melting peak temperature of the input compensation differential scanning calorimetry shown in −7121. The crystalline resin may show a plurality of melting peaks, but in the present invention, the maximum melting peak is regarded as the melting point.

  As melting | fusing point of crystalline resin, Preferably it is 50-120 degreeC, More preferably, it is 60-110 degreeC. When the melting point is lower than 50 ° C., toner storage stability and storage stability of a fixed image may become a problem. When the melting point is higher than 120 ° C., low-temperature fixing may be difficult.

In addition to the above polymerizable monomer, a compound having a shorter chain alkyl group, alkenyl group, aromatic ring or the like may be used for the purpose of adjusting the melting point, molecular weight, etc. of the crystalline resin.
Specific examples include dicarboxylic acids, alkyl dicarboxylic acids such as succinic acid, malonic acid, and oxalic acid, and phthalic acid, isophthalic acid, terephthalic acid, homophthalic acid, 4,4′-bibenzoic acid, 2,6- Examples include aromatic dicarboxylic acids such as naphthalenedicarboxylic acid and 1,4-naphthalenedicarboxylic acid, and nitrogen-containing aromatic dicarboxylic acids such as dipicolinic acid, dinicotinic acid, quinolinic acid, and 2,3-pyrazinedicarboxylic acid. Short chain alkyl diols such as succinic acid, malonic acid, acetone dicarboxylic acid, diglycolic acid, etc. In the case of short chain alkyl vinyl polymerizable monomers, methyl (meth) acrylate, (meth) Short chain alkyls such as ethyl acrylate, propyl (meth) acrylate, butyl (meth) acrylate, alkenyl (meth) Acrylic esters, vinyl nitriles such as acrylonitrile and methacrylonitrile, vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether, vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketones, ethylene, propylene, butadiene, isoprene, etc. Olefins and the like. These polymerizable monomers may be used individually by 1 type, and may use 2 or more types together.

In the present invention, a compound having a hydrophilic polar group can be used as long as it is copolymerizable as a binder resin for the toner.
As a specific example, when the resin used is a polyester, a dicarboxylic acid compound in which an aromatic ring such as sulfonyl-terephthalic acid sodium salt or 3-sulfonylisophthalic acid sodium salt is directly substituted with a sulfonyl group is used. In the case of a resin, unsaturated aliphatic carboxylic acids such as (meth) acrylic acid and itaconic acid, glycerin mono (meth) acrylate, fatty acid-modified glycidyl (meth) acrylate, zinc mono (meth) acrylate, zinc di (meth) acrylate, Esters of (meth) acrylic acid and alcohols such as 2-hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, and polypropylene glycol (meth) acrylate, sulfonyl groups at any of the ortho, meta, and para positions Have Derivatives of styrene, sulfonyl group-substituted aromatic vinyl such as sulfonyl group-containing vinyl naphthalene.

-Colorant-
Known colorants can be used as the colorant contained in the toner used in the present invention.
For example, examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite.
Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, and permanent yellow NCG. Is given.

Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, benzidine orange G, indanthrene brilliant orange RK, indanthrene brilliant orange GK and the like.
Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watch young red, permanent red 4R, risor red, brilliantamine 3B, brilliantamine 6B, dapon oil red, pyrazolone red, rhodamine B rake, lake red C Rose Bengal, Eoxin Red, Alizarin Lake and the like.

Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, induslen blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate.
Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.

Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.
Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.
Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.

  Moreover, dye can also be used as needed. Examples of the dye include various dyes such as basic, acidic, dispersed, and direct dyes, such as nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue. Moreover, these can be used individually or in mixture, and also in the state of a solid solution.

  These colorants are dispersed by a known method, and for example, a rotary shear type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high-pressure opposed collision type dispersing machine, or the like is preferably used. In addition, these colorants use polar surfactants and are dispersed in an aqueous system by the homogenizer.

The colorant used in the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The added amount of the colorant is 1 to 20 parts by weight with respect to 100 parts by weight of the binder resin.
When a magnetic material is used for the black colorant, 30 to 100 parts by weight is added unlike other colorants.

Moreover, when using toner as magnetism, you may contain a magnetic powder. As such magnetic powder, a substance magnetized in a magnetic field is used, and it is a ferromagnetic powder such as iron, cobalt, or nickel, or a compound such as ferrite or magnetite.
In particular, when the toner is obtained in the aqueous layer, it is necessary to pay attention to the water layer transferability of the magnetic material, and it is preferable that the surface of the magnetic material is previously subjected to surface modification, for example, a hydrophobic treatment.

-Surface layer components-
The surface of the toner used in the present invention may be covered with a surface layer. It is desirable that the surface layer does not greatly affect the mechanical properties and melt viscoelastic properties of the entire toner. Specifically, the thickness of the surface layer is preferably in the range of 0.001 to 0.5 μm, and more preferably 0.1 to 0.3 μm. When the thickness is less than 0.001 μm, unevenness in the thickness of the surface layer of the toner tends to occur, and the storage stability and fixing performance of the toner tend to vary. Further, if it is 0.5 μm or more, the low-temperature fixability due to the use of a crystalline resin such as a crystalline polyester resin may not be sufficiently exhibited.

In order to form a thin surface layer in the above-described range, a method of chemically treating the surface of particles containing a binder resin, a colorant, inorganic fine particles added as necessary, and other materials is preferable. Used for.
Examples of the component constituting the surface layer include silane coupling agents, isocyanates, vinyl monomers, and the like. In addition, a polar group is preferably introduced into the component constituting these surface layers, and the chemical affinity of the polar group increases the adhesive force between the toner and a fixing substrate such as paper.
The polar group may be any polar functional group such as carboxyl group, carbonyl group, epoxy group, ether group, hydroxyl group, amino group, imino group, cyano group, amide group, imide group. , Ester groups, sulfone groups and the like.

  Examples of the method for introducing the polar group into the component constituting the surface layer include a method of oxidizing by a strong oxidizing substance such as peroxide, ozone oxidation, plasma oxidation or the like, and bonding a polymerizable monomer containing the polar group by graft polymerization. And the like. By such chemical treatment, the polar group is firmly bonded to the component constituting the surface layer.

-Release agent-
As the release agent contained in the toner used in the image forming method of the present invention, a substance having a main maximum peak measured in accordance with ASTM D3418-8 at 85 to 105 ° C. is preferable.
If the main maximum peak is less than 85 ° C., the release amount of the release agent increases at the time of fixing, and roll contact traces are likely to occur. On the other hand, when the temperature exceeds 105 ° C., the amount of the release agent eluted decreases, so that the peelability from the fixing substrate deteriorates, and the smoothness of the image cannot be obtained, so that the glossiness may be impaired.

  For example, DSC-7 manufactured by Perkin Elmer is used for measurement of the main maximum peak. The temperature correction of the detection part of the apparatus uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan is used, an empty pan is set as a control, and the measurement is performed at a heating rate of 10 ° C./min.

Moreover, 85-105 degreeC is preferable and the maximum value of the endotherm calculated | required from the differential thermal analysis of a mold release agent, More preferably, it is 87-96 degreeC.
When the endothermic maximum value is less than 85 ° C., the melt viscosity of the release agent becomes low and the elution property at the time of oilless fixing is improved, but when the toner is produced by the emulsion polymerization aggregation method described above, the release agent is released. Since the mold material melts, it may be difficult to encapsulate the release agent in the toner during toner production. In this case, not only the particle size controllability of the toner is impaired, but also the amount of the releasing agent exposed on the toner surface increases, so that the powder flowability of the toner may be impaired.
Further, if the maximum value of endotherm exceeds 105 ° C., the production stability in the case of producing a toner by the emulsion polymerization aggregation method is good, but since the melt viscosity of the release agent is increased, In some cases, the releasability of the mold release agent is lowered, so that the peelability is lowered.

Further, the ratio of the endothermic amount based on the endothermic peak area obtained by differential thermal analysis (endothermic amount of 85 ° C. or less based on the endothermic peak area / total endothermic amount based on the endothermic peak area) is in the range of 5 to 15%. It is preferably within the range, and more preferably within the range of 7 to 13%. The ratio of the endothermic amount based on the area of the endothermic peak means the ratio of the endothermic amount due to the low melting point component (low molecular weight component) that is likely to transfer to the discharge roll in the release agent. .
Here, if the ratio of the endothermic amount due to the low melting point component is less than 5%, the compatibility between the release agent component and the binder resin is poor, and the fixability may be lowered. On the other hand, if it exceeds 15%, the binder resin is plasticized, and the elution property of the release agent at the time of fixing is lowered, and as a result, the oilless peelability may be impaired.

  Note that “endothermic amount of 85 ° C. or less based on endothermic peak area (hereinafter abbreviated as“ low melting point component endothermic amount ”)” and “total endothermic amount based on endothermic peak area (hereinafter“ total endothermic amount ”). "Means a value obtained based on a graph obtained when a differential thermal analysis is performed. Hereinafter, it will be specifically described with reference to the drawings.

FIG. 1 is a schematic diagram for explaining an analysis method of a graph obtained by differential thermal analysis of a release agent.
In FIG. 1, the horizontal axis represents temperature (° C.), the vertical axis represents the amount of heat, the direction toward the origin means heat absorption, and the direction away from the origin means heat generation. In addition, a solid line (endothermic peak) that draws a curve with respect to an increase in temperature in the graph indicates a change in endotherm / exotherm with respect to the temperature when the release agent is subjected to differential thermal analysis, and the temperature is lower than 85 ° C. The endotherm begins in the region, exceeds 85 ° C, and the endothermic peak shows a maximum value at the temperature Tmax (° C). When the temperature rises beyond the temperature Tmax (° C), the endotherm decreases and finally the endotherm ends. Is shown.

  Here, a state in which no endotherm / exotherm has occurred is defined as a standard (two straight line portions separated by a solid line endothermic peak in the graph, and a dotted line provided on an extension line of the two straight line portions), and a curve and a dotted line The region surrounded by is defined as “total endotherm”, and among the regions surrounded by the curve and dotted line, the region having a temperature of 85 ° C. or lower (the hatched portion in FIG. 1) was determined as “low melting point component endotherm”. .

Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak in the differential thermal analysis is preferably in the range of 6 to 15% by weight. More preferably, it is in the range of 7 to 10% by weight.
When the content of the release agent is less than 6% by weight, an elution amount sufficient for peeling between the fixing member and the fixing base material cannot be obtained at the time of oilless fixing, and the peelability is deteriorated. Since surface roughness occurs, the glossiness of the image may be lowered. On the other hand, if it exceeds 15% by weight, the releasability will be good, but the amount of the release agent on the image will increase. May exude and reduce the powder fluidity of the toner.

The maximum intensity of the endothermic peak means the endothermic peak height at the temperature Tmax (endothermic maximum value) in FIG. 1, and specifically, the solid line and the dotted line indicating the change in the heat quantity at the temperature Tmax are perpendicular It means the height to tie. Here, the content of the release agent in the toner can be easily determined from the height of the endothermic peak and a calibration curve prepared in advance using a standard sample.
In addition, when obtaining the release agent content in the toner using differential thermal analysis, it is necessary to use a toner containing the release agent as a sample. However, the heat of the release agent itself as described above is required. When evaluating the mechanical characteristics, the release agent can be evaluated alone.

Furthermore, the viscosity ηs140 of the release agent at 140 ° C. measured with an E-type viscometer equipped with a cone plate with a cone angle of 1.34 ° is in the range of 1.5 to 5.0 mPa · s. It is preferable that it is in the range of 2.5 to 4.0 mPa · s.
If the viscosity ηs140 of the release agent is lower than 1.5 mPa · s, the elution property at the time of fixing is good, but the release agent layer formed on the image becomes non-uniform, causing peeling unevenness and visible. Specifically, image gloss unevenness may occur, and roll contact traces may easily occur. In addition, when the viscosity is higher than 5.0 mPa · s, the elution property is lowered, so that at the time of oilless fixing, a sufficient release agent is not supplied between the image and the fixing member, resulting in poor peeling and sufficient High glossiness may not be obtained.

The viscosity ηs140 of the release agent is measured with an E-type viscometer. For the measurement, an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) equipped with an oil circulation type thermostat is used. Here, a cone plate having a cone angle of 1.34 ° is used.
Specifically, the measurement is performed as follows. First, the temperature of the circulating thermostat is set to 140 ° C., an empty sample measuring cup and a cone are set in a measuring device, and the temperature is kept constant while circulating oil. Next, when the temperature was stabilized, 1 g of the sample was put into the sample measuring cup, and the cone was allowed to stand still for 5 minutes. After stabilization, rotate the cone and measure. The rotational speed of the cone was 60 rpm. The measurement was performed three times, and the average value was determined as the viscosity η140.

In the toner used in the present invention, the amount of the release agent present on the toner surface determined by X-ray photoelectron spectroscopy (XPS) is preferably 11 to 40 atm%, more preferably 15 to 40 atm%.
If the amount of the release agent present on the surface of the toner is less than 11 atm%, the releasability at the time of oilless fixing may be impaired. May decrease.

The amount of the release agent present on the toner surface using XPS was determined using an X-ray electron spectrometer (JPS-9000MX: manufactured by JEOL Ltd.). Specifically, the toner surface is measured and quantified based on the following formula (8) from the total detected amount of carbon derived from components other than the release agent and the detected amount of carbon derived from the release agent. be able to.
Formula (8) Amount of release agent present on toner surface (atm%) = peak area derived from 1s orbital of carbon atoms in release agent / peak area derived from 1s orbital of carbon atoms on toner surface

Specific examples of releasing agents that can be used include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones having a softening point; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide. ; Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. Mineral / petroleum waxes; ester waxes of higher alcohols with higher fatty acids such as stearyl stearate and behenyl behenate; butyl stearate, propyl oleate, glyceryl monostearate, diste Ester waxes of higher fatty acids such as phosphate glycerides and pentaerythritol tetrabehenate and unit price or polyhydric lower alcohols; Examples include ester waxes composed of fatty acids and polyhydric alcohol multimers; higher sorbitan fatty acid ester waxes such as sorbitan monostearate; higher cholesterol fatty acid ester waxes such as cholesteryl stearate.
In the present invention, these release agents may be used alone or in combination of two or more.

  Of these, minerals such as paraffin wax, microcrystalline wax, and Fischer-Tropsch wax, petroleum wax, and polyalkylene, which is a modified product thereof, are uniformly eluted on the image surface at the time of fixing, and appropriate release It is excellent in that the thickness of the agent layer can be obtained.

-Additives-
Further, various additives can be internally or externally added to the toner used in the present invention as required.
For example, the toner used in the present invention preferably has at least one or more metal oxide particles externally added to the surface thereof. These metal oxide particles not only improve the fluidity of the toner, but also make the metal oxide particles compatible with the roll and the release agent at the stage of recrystallization of the release agent on the image surface after fixing. It has the effect of obstructing and making the roll contact mark less noticeable.

  Specific examples of the metal oxide particles include silica, titania, zinc oxide, strontium oxide, aluminum oxide, calcium oxide, magnesium oxide, cerium oxide, or a composite oxide thereof. Of these, silica and titania are preferably used from the viewpoints of particle size, particle size distribution, and manufacturability.

Further, these metal oxide particles produced by a wet method are preferable. The reason is that these metal oxide particles produced by a wet method have a large surface area, which makes it easier to inhibit compatibilization with the roll.
The average particle diameter of the metal oxide particles is preferably in the range of 1 to 40 nm and more preferably in the range of 5 to 20 nm in terms of the primary particle diameter.

  These metal oxide particles and metal nitride particles may be used alone or as a mixture of a plurality of types. The amount added to these toners is not particularly limited, but is preferably used in the range of 0.1 to 10% by mass. More specifically, it is in the range of about 0.2 to 8% by mass.

When the addition amount is less than 0.1% by mass, it is difficult to obtain the effect of the added metal oxide or the like, and when it exceeds 10% by mass, the required high glossiness may not be obtained.
These metal oxide particles are preferably subjected to surface modification such as hydrophobization because they are easily mixed in the release agent layer at the time of fixing, and the compatibilization between the release agent and the roll can be inhibited. A conventionally known method can be used as the surface modification means. Specific examples include coupling treatments such as silane, titanate, and aluminate.

  The coupling agent used for the coupling treatment is not particularly limited. For example, methyltrimethoxysilane, phenyltrimethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, vinyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ -Chloropropyltrimethoxysilane, γ-bromopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, fluoroalkyltrimethoxysilane, hexamethyldi Silane coupling agents such as silazane; titanate coupling agents; aluminate coupling agents;

In the present invention, in addition to the resin, the colorant, and the release agent, other components (particles) such as an internal additive, a charge control agent, an organic granule, a lubricant, and an abrasive are used depending on the purpose. It is possible to add.
Examples of the internal additive include ferrite, magnetite, reduced iron, cobalt, manganese, nickel, and other metals, alloys, and magnetic materials such as compounds containing these metals. A small amount can be used.

  The charge control agent is not particularly limited, but when a color toner is used, a colorless or light-colored agent can be preferably used. Examples thereof include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments.

  Examples of the organic particles include all particles usually used as external additives on the toner surface, such as vinyl resins, polyester resins, and silicone resins. These inorganic particles and organic particles can be used as fluidity aids, cleaning aids, and the like.

Examples of the lubricant include fatty acid amides such as ethylene bisstearylamide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate.
As an abrasive | polishing agent, the above-mentioned silica, alumina, cerium oxide etc. are mentioned, for example.

When the resin, the colorant, and the release agent are mixed, the content of the colorant may be 50% by mass or less, and is preferably in the range of about 2 to 40% by mass. .
Moreover, as content of the said other component, what is necessary is just a grade which does not inhibit the objective of this invention, generally it is a very small amount, Specifically, it is the range of 0.01-5 mass%, Preferably it is the range of 0.5-2 mass%.

-Toner production method-
The method for producing the toner used in the present invention is not particularly limited, but wet granulation is preferred. Suitable examples of the wet granulation method include known melt suspension methods, emulsion aggregation methods, and dissolution suspension methods. Hereinafter, the emulsion aggregation method will be described as an example.
When the toner is prepared using an emulsion polymerization aggregation method, specifically, the toner can be prepared as follows.
That is, an aggregating agent is added to a mixed solution in which at least a resin fine particle dispersion in which crystalline resin fine particles of 1 μm or less are dispersed, a colorant dispersion, and a release agent dispersion are mixed to form aggregated particles. The toner can be produced using a production method including an aggregating step and a fusing step in which the agglomerated particles are heated to a melting point or higher of the crystalline resin fine particles to be fused and united. Details of such a process will be described later.
Here, the crystalline resin fine particles can be produced by a method such as emulsion polymerization. For example, in emulsion polymerization, micelles are dispersed in a dispersion medium by adding several polymerizable monomers that do not dissolve in a solvent having a relatively high polarity, such as water, together with a dispersion stabilizer such as a surfactant. Then, polymerization can be started with a water-soluble polymerization initiator to produce crystalline resin fine particles.

  At this time, the polymerizable monomer in the micelle stabilizes the inside of the micelle by being more hydrophilic or highly polar on the surface of the micelle, in other words, on the contact surface with the solvent. The polymerization is initiated by the polymerization initiator. At this time, the polymerization tends to start from a polymerizable monomer having low polarity. The reason for this is considered to be that the polymerizable monomer with high polarity is deteriorated because π electrons in the polymerizable monomer having a polymerizable property are attracted by the electron attracting property of the polar group.

By utilizing this property, a highly polar polymerizable monomer in the micelle can be provided in the vicinity of the surface of the resin fine particles, and furthermore, by using this highly polar polymerizable monomer having crosslinkability. Crystalline resin fine particles can be obtained.
In the aggregation step, the particles in the resin fine particle dispersion, the colorant dispersion, and the release agent dispersion mixed with each other aggregate to form aggregated particles. Aggregated particles are formed by hetero-aggregation or the like, and have a monovalent or higher charge such as an ionic surfactant or metal salt having a polarity different from that of the aggregated particles for the purpose of stabilizing the aggregated particles and controlling the particle size / size distribution. Compound is added.

  When a polyester resin is used as the crystalline resin, the dispersion containing emulsified particles (droplets) of the polyester resin is a mixed solution (polymer solution) containing an aqueous medium, a sulfonated polyester resin, and if necessary, a colorant. Are formed by applying a shearing force to the mixed solution (hereinafter referred to as “emulsification step”). At that time, the viscosity of the polymer liquid can be lowered to form emulsified particles by heating or dissolving the polyester resin in an organic solvent. Moreover, a dispersing agent can also be used for stabilization of emulsified particles and thickening of the aqueous medium.

  Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, and sodium polyacrylate; sodium dodecylbenzenesulfonate, sodium octadecyl sulfate, sodium oleate, sodium laurate, and potassium stearate. Anionic surfactants; cationic surfactants such as laurylamine acetate and lauryltrimethylammonium chloride; zwitterionic surfactants such as lauryldimethylamine oxide; polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxy Surfactants such as nonionic surfactants such as ethylene alkylamine; tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate Include inorganic compounds such as barium carbonate.

  When an inorganic compound is used as the dispersant, a commercially available product may be used as it is. However, for the purpose of obtaining fine particles, a method of producing fine particles of an inorganic compound in the dispersant may be employed. As the usage-amount of the said dispersing agent, 0.01-20 weight part is preferable with respect to 100 weight part of said polyester resins (binder resin).

In the emulsification step, the polyester resin is copolymerized with a dicarboxylic acid having a sulfonic acid group (that is, a suitable amount of a dicarboxylic acid-derived component having a sulfonic acid group is included in the acid-derived component). ) And dispersion stabilizers such as surfactants can be reduced, or emulsified particles can be formed without using them.
Examples of the organic solvent include ethyl acetate and toluene, which are appropriately selected according to the polyester resin.

  The organic solvent is used in an amount of 50 to 5000 weights with respect to 100 parts by weight of the total amount of the polyester resin and other monomers used as necessary (hereinafter sometimes referred to simply as “polymer”). Part is preferable, and 120 to 1000 parts by weight are more preferable. In addition, a colorant can be mixed before forming the emulsified particles. As the colorant used, the colorants described above can be used.

Examples of the dispersion medium in the resin fine particle dispersion, the colorant dispersion, the release agent dispersion, and the dispersion of the other components include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohol. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the emulsifier used when forming the emulsified particles include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser. The size of the emulsified particles (droplets) of the polyester resin is preferably 0.01 to 1 μm, more preferably 0.03 to 0.4 μm, in terms of the average particle size (volume average particle size).

  As a method for dispersing the colorant, an arbitrary method, for example, a general dispersion method such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, or a dyno mill can be used. Furthermore, if necessary, an aqueous dispersion of these colorants can be prepared using a surfactant, or an organic solvent dispersion of these colorants can be prepared using a dispersant. As the surfactant and the dispersing agent used for dispersion, the same dispersing agents that can be used when dispersing the polyester resin can be used.

  When the colorant is mixed in the emulsification step, the crystalline resin and the colorant are mixed by mixing the colorant or the organic solvent dispersion of the colorant with the polymer organic solvent solution. In addition, a colorant can be mixed in the crystalline resin before forming the emulsified particles. As a method of mixing the colorant into the crystalline resin, melt dispersion using a disperser or the like can be mentioned.

  The emulsion aggregation method is a method in which a crystalline resin is produced by emulsion polymerization, heteroaggregated with a dispersion of a colorant, a release agent, etc., and fused at a temperature equal to or higher than the melting point to obtain a toner. For example, colored resin fine particles obtained by means such as seed polymerization using a colorant or a release agent as a nucleus, or release agent-containing resin fine particles may be heteroaggregated and fused.

  In the aggregation step, the fine particles in the resin fine particle dispersion, the colorant dispersion, and the release agent dispersion mixed with each other are aggregated to form aggregated particles. At this time, it is desirable that the particles be aggregated by heating at a temperature in the vicinity of the melting point of the crystalline resin in the resin fine particle dispersion and at a temperature below the melting point to form aggregated particles.

Aggregated particles are formed by making the pH of the mixed solution mixed with the dispersion acidic while stirring. As pH in this case, 2-6 are preferable and 2.5-5 are more preferable. Aggregated particles are formed by hetero-aggregation or the like, and have a monovalent or higher charge such as an ionic surfactant or metal salt having a polarity different from that of the aggregated particles for the purpose of stabilizing the aggregated particles and controlling the particle size / size distribution. Formed by adding a compound.
In the fusing step, melting is performed under temperature conditions equal to or higher than the melting point of the crystalline resin constituting the aggregated particles. In the fusing step, the crystalline resin in the aggregated particles melts and fuses with other components to form toner particles.

  In the fusion step, under the same agitation as in the aggregation step, the pH of the mixed solution containing the aggregated particles is set in the range of 3 to 7 to stop the progress of aggregation and heating at a temperature equal to or higher than the melting point of the crystalline resin. By doing so, the agglomerated particles are fused. There is no problem if the heating temperature is equal to or higher than the melting point of the crystalline resin. The heating time may be performed so that the fusion is sufficiently performed, and may be performed for about 0.5 to 10 hours.

  The particles fused in the fusing step can be obtained through a solid-liquid separation step such as filtration and, if necessary, a washing step and a drying step. In this case, in order to ensure sufficient charging characteristics and reliability as a toner, it is preferable to sufficiently wash in the washing step.

In addition, the aggregation process and the fusion process may be performed as follows, although various dispersions may be mixed together as described above to form aggregated particles and then fused and united. .
First, it has a monovalent or higher charge such as an ionic surfactant or a metal salt in a state in which the balance of the amount of each ionic dispersant contained in the mixed solution in which each dispersion is mixed is shifted in advance. This is ionically neutralized with a compound to form and stabilize the first stage aggregated particles (core aggregated particles) at a temperature below the melting point of the crystalline resin fine particles.

  Subsequently, a resin particle dispersion in which amorphous resin particles or crystalline resin particles treated with a dispersant having a polarity and an amount of a dispersant to compensate for a deviation in the balance of the amount of the ionic dispersant is added, Amorphous particles having a core-shell structure are formed by forming amorphous or crystalline resin fine particles on the surface of the core aggregate particles to form a coating layer. At this time, if necessary, the aggregated particles having the core-shell structure formed can be further stabilized by heating below the melting point (or glass transition temperature) of the resin contained in the core aggregated particles or the coating layer.

  Thereafter, the aggregated particles having a core-shell structure may be fused and united by heating to a temperature equal to or higher than the melting point (or glass transition temperature) of the resin contained in the core aggregated particles or the coating layer. It should be noted that the toner may be produced by repeatedly performing such agglomeration and fusion / unification stepwise operations a plurality of times. By utilizing such a method, various layer configurations such as a toner having a so-called core-shell structure in which the surface of the core layer containing a crystalline resin, a colorant, and a release agent is coated with a shell layer made of an amorphous resin. Toner can be obtained.

In addition to the emulsion polymerization aggregation method, a suspension polymerization method can be preferably used as a method for producing the toner used in the present invention.
In the suspension polymerization method, colorant particles, release agent particles and the like are suspended in an aqueous medium to which a dispersion stabilizer and the like are added together with a polymerizable monomer as required, and a desired particle size and particle size distribution are obtained. In this method, the polymerizable monomer is polymerized by means of heating or the like, and then the polymer is separated from the aqueous medium, and washed and dried as necessary to form toner particles.
Also in the case of the suspension polymerization method, there is a step of adding a polymerizable monomer into the aqueous medium as described above. At this time, a highly polar polymerizable monomer, and further a highly crosslinkable polymerizable monomer. The same effect can be obtained by using.

  Specific examples of the polymerizable monomer include homopolymers or copolymers of styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic Homopolymers of esters having vinyl groups such as n-butyl acid, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate Or copolymers; homopolymers or copolymers of vinyl nitriles such as acrylonitrile and methacrylonitrile; homopolymers or copolymers of vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl Ketone, vinyl isoprop Homopolymers or copolymers of ketone compounds, ethylene, propylene, butadiene, homopolymers or copolymers of olefins such as isoprene; and the like.

Further, silicone resins including methylsilicone, methylphenylsilicone, etc., polyesters containing bisphenol, glycols, epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins, and the like may be used.
These resins may be used alone or in combination of two or more.

  Specifically, among the polymerizable monomers, styrenes such as styrene, parachlorostyrene, and α-methylstyrene; short-chain alkyl acrylates such as methyl acrylate and methyl methacrylate; and acrylic acid n It is preferable to use a copolymer obtained by combining -propyl, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, or the like.

  Specific examples of the crosslinking agent include aromatic polyvinyl compounds such as divinylbenzene and divinylnaphthalene; divinyl phthalate, divinyl isophthalate, divinyl terephthalate, divinyl homophthalate, divinyl trimesate / trivinyl, divinyl naphthalenedicarboxylate, Polyvinyl esters of aromatic polyvalent carboxylic acids such as divinyl biphenyl carboxylate; divinyl esters of nitrogen-containing aromatic compounds such as divinyl pyridine dicarboxylate; vinyl pyromunate, vinyl furan carboxylate, vinyl pyrrole-2-carboxylate , Vinyl esters of unsaturated heterocyclic compounds such as vinyl thiophenecarboxylate; butanediol methacrylate, hexanediol acrylate, octanediol methacrylate, decanediol acrylate, dodeca (Meth) acrylic acid esters of linear polyhydric alcohols such as diol methacrylate; branches such as neopentyl glycol dimethacrylate and 2-hydroxy-1,3-diaacryloxypropane, (meth) acrylic of substituted polyhydric alcohols Acid esters; polyethylene glycol di (meth) acrylate, polypropylene polyethylene glycol di (meth) acrylates; divinyl succinate, divinyl fumarate, vinyl / divinyl maleate, divinyl diglycolate, vinyl / divinyl itaconate, acetone dicarboxylic acid Divinyl, divinyl glutarate, divinyl 3,3′-thiodipropionate, trans-divinyl aconitate / trivinyl, divinyl adipate, divinyl pimelate, divinyl suberate, divinyl azelate, Parent acid divinyl, dodecanedioic acid divinyl, the polyvinyl esters of polycarboxylic acids such as oxalic acid, divinyl; and the like.

These crosslinking agents may be used alone or in combination of two or more. In addition, since the polymerization is required to be slower than that of a normal polymerizable monomer, linear polyhydric alcohols such as butanediol methacrylate, hexanediol acrylate, octanediol methacrylate, decanediol acrylate, and dodecanediol methacrylate are used. (Meth) acrylic acid esters; Branched and substituted polyhydric alcohols such as neopentyl glycol dimethacrylate and 2-hydroxy-1,3-diacryloxypropane; polyethylene glycol di (meth) It is preferable to use acrylate, polypropylene polyethylene glycol di (meth) acrylates and the like.
The content of the crosslinking agent is preferably in the range of 0.05 to 5% by mass, more preferably in the range of 0.1 to 1.0% by mass, based on the total amount of polymerizable monomers.

In particular, when the crystalline resin is polyester, unsaturated polycarboxylic acids such as fumaric acid, maleic acid, itaconic acid, and trans-aconitic acid are copolymerized in the polyester, and then are multiplexed in the binder resin. You may use the method of bridge | crosslinking using bonding parts or another vinyl type compound. These crosslinking agents may be used alone or in combination of two or more.
As a method of cross-linking with these cross-linking agents, a method of polymerizing and cross-linking with a cross-linking agent at the time of polymerization of the polymerizable monomer may be used, or after the unsaturated portion remains in the resin and the resin is polymerized, or a toner is produced Thereafter, a method of crosslinking the unsaturated portion by a crosslinking reaction may be used.

  When the binder resin is polyester, the polymerizable monomer can be polymerized by condensation polymerization. As the polycondensation catalyst, known ones can be used. Specific examples include titanium tetrabutoxide, dibutyltin oxide, germanium dioxide, antimony trioxide, tin acetate, zinc acetate, tin disulfide and the like. Can be mentioned. When the resin to be used is a vinyl resin, the polymerizable monomer can be polymerized by radical polymerization.

Examples of the polymerization initiator when the toner binder resin is produced by radical polymerization of a polymerizable monomer include the following.
There is no restriction | limiting in particular as an initiator for radical polymerization used here. Specifically, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide Ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, tert-butyl hydroperoxide pertriphenyl acetate, tert-butyl formate, Peroxides such as tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl perN- (3-toluyl) carbamate, 2,2 '-Azobispro Bread, 2,2′-dichloro-2,2′-azobispropane, 1,1′-azo (methylethyl) diacetate, 2,2′-azobis (2-amidinopropane) hydrochloride, 2,2 ′ -Azobis (2-amidinopropane) nitrate, 2,2'-azobisisobutane, 2,2'-azobisisobutyramide, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2- Methyl methylpropionate, 2,2′-dichloro-2,2′-azobisbutane, 2,2′-azobis-2-methylbutyronitrile, dimethyl 2,2′-azobisisobutyrate, 1,1′-azobis (1 -Methylbutyronitrile-3-sodium sulfonate), 2- (4-methylphenylazo) -2-methylmalonodinitrile, 4,4'-azobis-4-cyanovaleric acid, 3,5-dihydroxymethylphenyl Zo-2-methylmalonodinitrile, 2- (4-bromophenylazo) -2-allylmalonodinitrile, 2,2'-azobis-2-methylvaleronitrile, 4,4'-azobis-4-cyanoyoshi Dimethyl herbate, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobiscyclohexanenitrile, 2,2′-azobis-2-propylbutyronitrile, 1,1′-azobis-1 -Chlorophenylethane, 1,1'-azobis-1-cyclohexanecarbonitrile, 1,1'-azobis-1-cycloheptanenitrile, 1,1'-azobis-1-phenylethane, 1,1'-azobiscumene, 4-Nitrophenylazobenzylcyanoacetate, phenylazodiphenylmethane, phenylazotriphenylmethane, 4-nitrophenylazotrif Nylmethane, 1,1′-azobis-1,2-diphenylethane, poly (bisphenol A-4,4′-azobis-4-cyanopentanoate), poly (tetraethylene glycol-2,2′-azobisiso) Azo compounds such as butyrate), 1,4-bis (pentaethylene) -2-tetrazene, 1,4-dimethoxycarbonyl-1,4-diphenyl-2-tetrazene and the like.

  Among these, preferred are water-soluble compounds, specifically hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, peroxide. Examples thereof include dichlorobenzoyl, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, and diisopropyl peroxycarbonate.

These polymerization initiators may be mixed in advance in the resin fine particles in the resin fine particle dispersion, or may be incorporated into the aggregated particles formed in the aggregation step. Further, it may be introduced after the fusion step or after the fusion step.
When the polymerization initiator is introduced after the fusing step or the fusing step, a solution obtained by dissolving the polymerization initiator in an organic solvent is added to a particle dispersion (resin fine particle dispersion or the like). These polymerization initiators may be added with known crosslinking agents, chain transfer agents, polymerization inhibitors and the like for the purpose of controlling the degree of polymerization.

  In the production of the toner used in the image forming method of the present invention, for example, stabilization during dispersion in the suspension polymerization method, resin fine particle dispersion, colorant dispersion, and release agent dispersion in the emulsion polymerization aggregation method A surfactant can be used for the purpose of stabilizing the dispersion of the composition.

  Examples of the surfactant include anionic surfactants such as sulfate, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an ionic surfactant is preferable, and an anionic surfactant and a cationic surfactant are more preferable.

When preparing a toner in a liquid phase such as an emulsion polymerization aggregation method, various surfactants are used to improve the dispersibility in the liquid phase of resin fine particles, colorant particles, and release agent particles. In this case, it is advantageous to use an anionic surfactant having a strong dispersion power.
The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may be used in combination of 2 or more type.

  Specific examples of anionic surfactants include fatty acid soaps such as potassium laurate, sodium oleate, and castor oil sodium; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate, and nonyl phenyl ether sulfate; lauryl sulfonate , Sodium alkylnaphthalene sulfonate such as dodecylbenzene sulfonate, triisopropyl naphthalene sulfonate, dibutyl naphthalene sulfonate; sulfone such as naphthalene sulfonate formalin condensate, monooctyl sulfosuccinate, dioctyl sulfosuccinate, lauric acid amide sulfonate, oleic acid amide sulfonate Acid salts; lauryl phosphate, isopropyl phosphate, nonylphenyl ether Phosphoric acid esters such as Sufeto; dialkyl sulfosuccinate salts such as sodium dioctyl sulfosuccinate; sulfosuccinate salts such as sulfosuccinate lauryl disodium; and the like.

  Specific examples of the cationic surfactant include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate, and other amine salts; lauryltrimethylammonium chloride, dilauryldimethylammonium Chloride, distearyldimethylammonium chloride, distearyldimethylammonium chloride, lauryldihydroxyethylmethylammonium chloride, oleylbispolyoxyethylenemethylammonium chloride, lauroylaminopropyldimethylethylammonium ethosulphate, lauroylaminopropyldimethylhydroxyethylammonium perchlorate, alkylbenzene Trimethylammonium chloride, Quaternary ammonium salts such as quilts trimethyl ammonium chloride; and the like.

  Specific examples of the nonionic surfactant include alkyl ethers such as polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxy Alkyl phenyl ethers such as ethylene nonyl phenyl ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxyethylene Alkylamines such as oleyl amino ether, polyoxyethylene soybean amino ether, polyoxyethylene beef tallow amino ether; Alkyl amides such as ethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether and polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearic acid Alkanolamides such as diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate And so on.

The content of the surfactant in each dispersion is generally in the range of about 0.01 to 10% by mass, more preferably in the range of 0.05 to 5% by mass, and still more preferably 0. .About 1-2 mass%.
When the content is less than 0.01% by mass, each dispersion liquid such as a resin fine particle dispersion, a colorant dispersion, and a release agent dispersion becomes unstable. There is a problem such as the release of specific particles due to the difference in stability between them, and when the amount exceeds 10% by mass, the particle size distribution of the particles becomes wide and the control of the particle size becomes difficult There is. In general, a suspension-polymerized toner dispersion having a large particle size is stable even if the amount of the surfactant used is small.

  Further, as the dispersion stabilizer used in the suspension polymerization method, a slightly water-soluble and hydrophilic inorganic fine powder can be used. Examples of the inorganic fine powder that can be used include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate (hydroxyapatite), clay, diatomaceous earth, bentonite and the like. Among these, calcium carbonate, tricalcium phosphate, and the like are preferable from the viewpoints of easy particle size formation and easy removal.

  Also, a room temperature solid aqueous polymer or the like can be used. Specifically, cellulose compounds such as carboxymethyl cellulose and hydroxypropyl cellulose, polyvinyl alcohol, gelatin, starch, gum arabic and the like can be used.

  The amount of these flocculants to be added varies depending on the valence of the charge, but they are all small, in the case of monovalent, about 3% by mass or less, in the case of divalent, about 1% by mass or less, in the case of trivalent Is about 0.5 mass% or less. Since the amount of the flocculant is preferably small, it is preferable to use a compound having a large valence.

Examples of the dispersion medium in the resin fine particle dispersion, the colorant dispersion, the release agent dispersion, and other components used in the wet manufacturing method described above include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, alcohol, and the like. These may be used individually by 1 type and may use 2 or more types together.

-Toner shape-
The toner shape factor SF1 of the toner is preferably in the range of 120 to 140.
When the toner shape factor SF1 is less than 120, the blade cleaning property of the transfer residual toner on the photosensitive member is impaired, and when it exceeds 140, the fluidity of the toner is lowered, and the transfer property may be adversely affected from the beginning.
The toner shape factor SF1 is a value represented by the following expression (9).
Formula (9) Toner shape factor SF1 = (π / 4) × (L ² / A) × 100
In Equation (9), L represents the maximum length of toner particles, and A represents the projected area of toner particles.

  The particle size distribution index of the toner used in the present invention is a volume average particle size distribution index GSDv of at most 1.30, and the ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp <GSDp / GSDv> is preferably 0.95 or more.

  When the volume distribution index GSDv exceeds 1.30, the unevenness of the image becomes large, resulting in uneven glossiness, and roll contact traces are likely to occur in an image portion with high glossiness. Further, when the ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index is less than 0.95, it means that the amount of the small particle size toner increases, and as described above, the mold release contained per toner. The amount of the agent is likely to be uneven, and as a result, sufficient glossiness may not be obtained due to poor peeling.

The surface area of the toner used in the present invention is not particularly limited, and any toner can be used as long as it can be used for a normal toner. Specifically, when the BET method is used, a range of 0.5 to 10 m ² / g is preferable, preferably a range of 1.0 to 7 m ² / g, more preferably about 1.2 to ⁵ m ² / g. It is a range. Furthermore, the range of about 1.2-3 m < ² > / g is preferable.

<Developer>
In the present invention, the toner described above can be used as a one-component developer composed only of toner, or can be used as a two-component developer in combination with a carrier.
For example, when a carrier is used, the carrier is not particularly limited, and examples thereof include known carriers, for example, described in JP-A Nos. 62-39879 and 56-11461. Known carriers such as a resin-coated carrier can be used.

  Specific examples of the carrier include the following resin-coated carriers. Examples of the core particle of the carrier include ordinary iron powder, ferrite, and magnetite granulated product, and the volume average particle size is in the range of about 30 to 200 μm.

  Examples of the coating resin for the resin-coated carrier include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, acrylic acid 2 -Α-methylene fatty acid monocarboxylic acids such as ethylhexyl, methyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, etc. Vinyl nitriles; vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl Homopolymers such as vinyl ketones such as ketones; olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; and copolymers composed of two or more types of monomers Furthermore, silicone resins containing methylsilicone, methylphenylsilicone, etc., polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like can be mentioned. These resins may be used alone or in combination of two or more. The coating amount of the coating resin is preferably in the range of about 0.1 to 10 parts by weight and more preferably in the range of 0.5 to 3.0 parts by weight with respect to 100 parts by weight of the core particles.

For manufacturing the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used. .
The mixing ratio of the toner and carrier contained in the developer is not particularly limited and can be appropriately selected depending on the purpose.

<Image forming method>
The image forming method of the present invention includes a fixing step in which a toner image formed using the above-described toner (developer) is fixed on a fixing substrate by a fixing device to form an image, and the image is formed. A discharging step of discharging the fixed base material out of the fixing device by transporting at least the surface of the fixing base material on which the image is formed and a discharge roll in contact with each other. Although it will not specifically limit if there is, you may have other processes as needed.

As a result of studies by the present inventors, it has been confirmed that roll contact marks are likely to occur when an image having a 75-degree specular gloss measured in accordance with JIS Z8741 is 80 to 120%. did. On the other hand, in general, the glossiness of an image and fixing conditions vary depending on the fixing equipment used, the contact time during fixing, and the like, in addition to the binder resin and release agent characteristics of the toner used.
As described above, various factors are involved in the occurrence of the roll contact trace. However, when the image is formed by using the image forming method of the present invention, the above-mentioned 75 degree specular gloss is 80 to 120%. Even in the case of forming such an image, the occurrence of a roll contact mark can be suppressed.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.
<Measuring method of various characteristics>
First, the measurement method and evaluation method of the toner and developer used in the following examples and comparative examples will be described.
(Haze measurement method)
Haze (cloudiness) is represented by a ratio (Td / Tt) of diffuse light transmittance (Td) and total light transmittance (Tt), and based on the measurement method of JISK7136, a transparent sheet (Fuji Xerox Co., Ltd .: V507). ) The image formed above was prepared on a square test piece having a side of 50 mm, and measured using a single beam type haze computer (model HZ-1, manufactured by Suga Test Instruments Co., Ltd.). The image forming conditions used for the haze measurement will be described later.

(Method for measuring viscosity of release agent)
The viscosity of the release agent was measured with an E-type viscometer. In the measurement, an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) equipped with an oil circulation type thermostatic bath was used.
In the measurement, a cone plate having a cone angle of 1.34 ° was used. First, a sample is put into a cup, the temperature of the thermostatic bath is set to 140 ° C., an empty measuring cup and cone are set in a measuring device, and the temperature is kept constant while circulating oil. When the temperature is stabilized, 1 g of the sample is put in the measuring cup, and the cone is allowed to stand for 10 minutes in a stationary state. After stabilization, rotate the cone and measure. The rotational speed of the cone was 60 rpm. The measurement was performed three times, and the average value was determined as the viscosity ηs140.

(Method for measuring particle diameter of resin fine particles, colorant particles, release agent particles)
The particle diameters of the resin fine particles, the colorant particles, and the release agent particles in various dispersions used for the production of the toner are measured with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.).

(Measurement method of toner particle size and particle size distribution)
The particle size and particle size distribution index of the toner were Coulter Counter TA-II (Beckman-Coulter), and the electrolyte was ISOTON-II (Beckman-Coulter).
First, 0.5 to 50 mg of a measurement sample was added to 2 ml of a surfactant, preferably a 5% by weight aqueous solution of sodium alkylbenzenesulfonate as a dispersant, and a sample was prepared by adding this to 100 to 150 ml of the electrolytic solution.

Subsequently, the electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and by the Coulter counter TA-II type, an aperture having an aperture diameter of 100 μm is used. The particle size distribution of the particles was measured to obtain a volume average distribution and a number average distribution.
For the particle size range (channel) obtained by dividing the measured particle size distribution, a cumulative distribution is drawn from the smaller diameter side to each of the volume and the number, and the particle size that becomes 16% cumulative is the volume D16% and / or several 16%. And the particle size at which 50% accumulated was defined as volume D50% or several D50%. Furthermore, the volume D84% and / or the number D84% were defined. Using each parameter determined based on these definitions, the volume average particle size distribution index (GSDv) was calculated from D84v / D16v, and the number average particle size index (GSDp) was calculated from D84p / D16p.

(Toner shape factor measurement method)
The toner shape factor SF1 is obtained by taking an optical microscope image of toner dispersed on a slide glass into a Luzex image analyzer through a video camera, measuring the maximum length of toner particles and the projected area of toner particles for each toner, and using the formula (9 ), And an average value of 50 or more samples.

(Method for measuring molecular weight distribution of toner constituents)
The molecular weight distribution of the binder resin constituting the toner is measured under the following conditions using a GPC (gel permeation chromatography) method.
First, “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corp.)” is used as a measuring device, and “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corp.)” is used as a column. Two were used, and THF (tetrahydrofuran) was used as an eluent.
The measurement conditions were set to a sample concentration of 0.5%, a flow rate of 0.6 ml / min, a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector was used. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

(Releasing agent layer thickness and external additive particle size (metal oxide particle size))
A Hitachi scanning electron microscope S-4100 (manufactured by Hitachi, Ltd.) was used to measure the thickness of the release agent layer on the surface of the image and the particle size of the metal oxide externally added to the toner surface.
In the case of an image, a section cut with a fixing substrate with a diamond cutter or the like, and in the case of a toner, vapor deposition is performed for 180 seconds under an ion sputtering (E-1030: manufactured by Hitachi Instruments Service Co., Ltd.) under a condition of 15 Pa or less. went. A platinum-palladium target was used as a target for vapor deposition. The method for measuring the thickness of the release agent layer of the image is as described above. Further, 100 metal oxide particles are arbitrarily selected from the SEM image of the toner surface photographed at an arbitrary particle size of the metal oxide on the toner surface from 30000 times, and based on the particle size of these metal oxides and the photographing magnification. Asked.

(Calculation method of release agent content and viscosity measurement method of release agent)
The measurement of the content of the release agent contained in the toner was obtained as follows.
First, the toner was dissolved in an organic solvent such as acetone, dissolved in an organic solvent such as acetone, and centrifugal separation was repeated to separate the release agent from the toner. Subsequently, the separated release agent was dried by heating and / or reduced pressure or the like, measured according to ASTM D3418-8, and after accurately weighing the release agent, the absorption peak and endothermic amount were measured. Subsequently, the same measurement was performed for samples with different release agent amounts, and a calibration curve was created from the relationship between the release agent amount and the endothermic amount.
Next, the content of the release agent in the toner was calculated from the endothermic peak height obtained by measuring the toner sample whose release agent content is to be measured and the calibration curve.
Further, the viscosity of the release agent contained in the toner was obtained by measuring the release agent separated from the toner with an E-type viscometer in the same manner as when preparing a calibration curve for obtaining the release agent content.

<Preparation of toner (developer)>
The toner (developer) used in Examples and Comparative Examples was prepared using the above-described wet manufacturing method. A method for preparing various dispersions and a method for producing toner using these dispersions will be described in detail below.

(Preparation of crystalline polyester resin dispersion (resin fine particle dispersion 1))
-Dodecanedioic acid: 92.5 mol%,
-Sodium dimethyl-5-sulfonate isophthalate: 3 mol%
-5-t-butylisophthalic acid: 4.5 mol%
10 decanediol: 100 mol%
Ti (OBu) ₄ : 0.014 mol%
The above compound was put into a heat-dried three-necked flask, and the air in the container was decompressed by a depressurization operation. The atmosphere was then inerted with nitrogen gas, and refluxed at 180 ° C. for 6 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 220 ° C. by vacuum distillation and stirred for 2.5 hours. When the mixture became viscous, the molecular weight was confirmed by GPC. When the weight average molecular weight reached 11,000, vacuum distillation was performed. After stopping and air cooling, crystalline polyester was obtained.

  The melting point of the obtained crystalline polyester was measured using a thermal analyzer of a differential scanning calorimeter (manufactured by Mac Science: DSC3110, thermal analysis system 001) (hereinafter abbreviated as “DSC”). The measurement was performed from room temperature to 150 ° C. at a heating rate of 10 ° C. per minute, and the melting point was obtained by analyzing according to JIS standards (see JIS K-7121). When measured by this method, the melting point was 80 ° C. The ester concentration was 0.078.

  Next, 80 g of this crystalline polyester and 587 g of deionized water are placed in a stainless beaker, placed in a warm bath and heated to 95 ° C. When the crystalline polyester resin is melted, the mixture is stirred at 8000 rpm using a homogenizer (manufactured by IKA: Ultra Turrax T50). At the same time, dilute aqueous ammonia is added to adjust the pH to 7.0. Subsequently, emulsification dispersion was performed while dropping 20 g of an aqueous solution obtained by diluting 0.8 g of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK).

The obtained resin fine particles were 210 nm when the number average particle diameter D _50n of the resin fine particles was measured with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.), and a differential scanning calorimeter (manufactured by Mac Science Co., Ltd.). The melting point of the resin was measured at a temperature rising rate of 10 ° C./min using DSC 3110, thermal analysis system 001), and had a clear peak, which was 80 ° C., and a molecular weight measuring instrument (HLC-8020, manufactured by Tosoh Corporation) was used. It was 28000 when the weight average molecular weight (polystyrene conversion) was measured using THF as a solvent. The ester concentration was 0.078.
As a result, a crystalline polyester resin dispersion 1 having a center diameter of 210 nm, a solid content of 20%, a melting point of 80 ° C., and an Mw of 25000 was obtained.

(Preparation of amorphous resin dispersion (resin fine particle dispersion 2))
<Oil layer>
-Styrene (Wako Pure Chemical Industries, Ltd.): 30 parts by weight-n-butyl acrylate (Wako Pure Chemical Industries, Ltd.): 10 parts by weight-β-carboethyl acrylate (Rodia Nikka Co., Ltd.): 1.1 parts by weight-Acrylic acid: 0.2 part by weight / dodecanethiol (manufactured by Wako Pure Chemical Industries): 0.4 part by weight <aqueous layer 1>
-Ion exchange water: 17.0 parts by weight-Anionic surfactant (manufactured by Rhodia): 0.39 parts by weight <Water layer 2>
-Ion exchange water: 40 parts by weight-Anionic surfactant (manufactured by Rhodia): 0.06 parts by weight-Potassium persulfate (manufactured by Wako Pure Chemical Industries): 0.30 parts by weight-Ammonium persulfate (Wako Pure Chemical Industries, Ltd.) Manufactured): 0.10 parts by weight

  The oil layer component and the water layer 1 component were placed in a flask and mixed with stirring to obtain a monomer emulsified dispersion. Furthermore, the components of the aqueous layer 2 were charged into the reaction vessel, and the flask was sufficiently substituted with nitrogen and stirred, and heated in an oil bath until the temperature in the flask reached 75 ° C. The monomer emulsion dispersion was gradually dropped into the flask over 3 hours to carry out emulsion polymerization. After completion of the dropping, the polymerization was further continued at 75 ° C., and the polymerization was terminated after 3 hours to obtain a binder resin fine particle dispersion.

With respect to the obtained binder resin fine particles, the number average particle diameter D _50n was measured in the same manner as described above, and it was 250 nm. The glass transition point was measured, and it was 51.5 ° C. It was 30000 when measured.
As a result, an anionic binder resin fine particle dispersion 2 having a center diameter: 250 nm, a solid content: 42%, a glass transition point: 51.5 ° C., and a weight average molecular weight (Mw): 30000 was obtained.

(Preparation of colorant dispersion 1)
Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika Co., Ltd.): 45 parts by weight The mixture was dissolved and dispersed with a homogenizer (manufactured by IKA, Ultra Tarrax) for 10 minutes to obtain a colorant dispersion having a central particle size of 170 nm.

(Preparation of colorant dispersion 2)
-Magenta pigment (PR238: Sanyo Dye): 45 parts by weight-Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.): 5 parts by weight-Ion exchange water: 200 parts by weight (IKA, Ultra Turrax) was dispersed for 10 minutes to obtain a colorant dispersion having a central particle size of 155 nm.

(Preparation of colorant dispersion 3)
-Magenta pigment (PR122: manufactured by Dainichi Seika Co., Ltd.): 45 parts by weight-Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.): 5 parts by weight-Ion exchange water: 200 parts by weight The mixture was dispersed for 10 minutes with a homogenizer (manufactured by IKA, Ultra Tarrax) to obtain a colorant dispersion having a central particle size of 180 nm.

(Preparation of colorant dispersion 4)
-Yellow pigment (PY74: Clariant): 45 parts by weight-Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.): 5 parts by weight-Ion-exchanged water: 200 parts by weight The mixture was dispersed for 10 minutes by IKA (Ultra Turrax) to obtain a colorant dispersion having a center particle size of 172 nm.

(Preparation of mold release agent dispersion 1)
・ Polyalkylene wax FNP0092 (melting point: 91 ° C., manufactured by Nippon Seiwa Co., Ltd.): 45 parts by weight ・ Cationic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 5 parts by weight The mixture was heated to 95 ° C. and sufficiently dispersed with an Ultra-Turrax T50 manufactured by IKA, and then dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion having a center diameter of 200 nm and a solid content of 24.3%.
The viscosity ηs140 of the release agent measured using an E-type viscometer was 3.2 mPa · s. In addition, the temperature at the maximum value of endotherm obtained by suggestion thermal analysis is 90 ° C., and further, the endothermic area due to the low molecular weight component (the endothermic amount of 85 ° C. or less / endothermic peak area based on the endothermic peak area). The total endothermic value was 12%.

(Preparation of release agent dispersion 2)
Paraffin wax HNP0190 (melting point 89 ° C., Nippon Seiwa Co., Ltd.): 45 parts by weight Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.): 5 parts by weight ion-exchanged water: 200 parts by weight The mixture was heated to 0 ° C. and sufficiently dispersed with IKA Ultra Turrax T50, and then dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion having a center diameter of 215 nm and a solid content of 25.2%.
The viscosity ηs140 of the release agent measured using an E-type viscometer was 3.8 mPa · s. Further, the temperature at the maximum value of the endotherm obtained by suggestion thermal analysis is 89.0 ° C., and further, the endothermic area due to the low molecular weight component (the endothermic amount / endothermic peak of 85 ° C. or less based on the endothermic peak area The total endothermic value based on area) was 16%.

(Preparation of release agent dispersion 3)
Paraffin wax PW725 (melting point 104 ° C., manufactured by Toyo Petrolite Co., Ltd.): 45 parts by weight Cationic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by ion exchange water: 200 parts by weight And then sufficiently dispersed with an Ultra-Turrax T50 manufactured by IKA, and then dispersed with a pressure discharge type gorin homogenizer to obtain a solid content of 25.4. % Release agent dispersion.
The viscosity ηs140 of the release agent measured using an E-type viscometer was 3.5 mPa · s. Further, the temperature at the maximum value of the endotherm obtained by suggestive thermal analysis is 103.8 ° C., and the endothermic area due to the low molecular weight component (the endothermic amount of 85 ° C. or less / endothermic peak based on the endothermic peak area). The total endothermic value based on area was 4%.

(Preparation of release agent dispersion 4)
Polyalkylene FT100 (melting point 110 ° C., manufactured by Nippon Seiwa Co., Ltd.): 45 parts by weight Cationic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku): 5 parts by weight Ion-exchanged water: 200 parts by weight The mixture was heated to 0 ° C. and sufficiently dispersed with IKA Ultra Turrax T50, and then dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion having a center diameter of 195 nm and a solid content of 25.1%.
The viscosity ηs140 of the release agent measured using an E-type viscometer was 5.3 mPa · s. Further, the temperature at the maximum value of the endotherm obtained by suggestion thermal analysis is 109.5 ° C., and the endothermic area due to the low molecular weight component (the endothermic amount / endothermic peak of 85 ° C. or less based on the endothermic peak area). The total endothermic value based on area was 3%.

(Preparation of release agent dispersion 5)
・ Polyalkylene wax FNP0080 (melting point 77 ° C., Nippon Seiwa Co., Ltd.): 45 parts by weight ・ Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku): 5 parts by weight ・ Ion-exchanged water: 200 parts by weight Above 85 ° C. Then, the mixture was sufficiently dispersed with an Ultra Turrax T50 manufactured by IKA, and then dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion having a center diameter of 180 nm and a solid content of 26.5%.
The viscosity ηs140 of the release agent measured using an E-type viscometer was 1.2 mPa · s. Moreover, the temperature at the maximum value of the endotherm obtained by suggestive thermal analysis is 77.5 ° C., and the endothermic area due to the low molecular weight component (the endothermic amount / endothermic peak of 85 ° C. or less based on the endothermic peak area). The total endothermic value based on area was 87%.

(Toner Production Example 1)
-Resin fine particle dispersion 1: 360 parts by weight-Colorant dispersion 1: 18 parts by weight-Release agent dispersion 1: 24 parts by weight Nonionic surfactant (IGEPAL CA897, manufactured by Rhône-Poulenc): 1 part by weight Ion exchange water was added to prepare a solid content of 15%. The above was thoroughly mixed and dispersed with Ultra Turrax T50 in a round stainless steel flask. Next, 1.0 part by weight of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. Further, the flask was heated to 50 ° C. with stirring in an oil bath for heating. After maintaining at 50 ° C. for 60 minutes, the pH of the system was adjusted to 10.0 with a 0.5 mol / L sodium hydroxide aqueous solution, and then the stainless steel flask was sealed, and stirring was continued using a magnetic seal. Heat to 0 ° C. and hold for 3 hours.

After completion of the reaction, ice water was added and quenched at a rate of temperature decrease of 100 ° C./min. After sufficiently washing with filtration and ion-exchanged water, solid-liquid separation was performed by Nutsche suction filtration. This was further redispersed in 3 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes.
This was repeated five more times, and when the pH of the filtrate was 7.01, the electric conductivity was 9.7 μS / cm, and the surface tension was 71.2 Nm, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. It was. Next, vacuum drying was continued for 12 hours to produce toner 1.

  When the particle size of the toner 1 was measured with a Coulter counter, the volume average particle size was 5.89 μm, the volume average particle size distribution index GSDv was 1.24, the number average particle size distribution index GSDp was 1.25, and the volume average particle size distribution index GSDv. The ratio <GSDp / GSDv> to the number average particle size distribution index GSDp was 1.01. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 22 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 9%, and the maximum endothermic value of the release agent contained in the toner is 91.1. Furthermore, the value of the endothermic area due to the low molecular weight component (endothermic amount of 85 ° C. or less based on the endothermic peak area / total endothermic amount based on the endothermic peak area) was 11%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 3.2 mPa · s.

(Toner Production Example 2)
-Resin fine particle dispersion 1: 358 parts by weight-Colorant dispersion 2: 2: 10 parts by weight-Colorant dispersion 3: 10 parts by weight Except that the resin fine particle dispersion and the colorant dispersion are changed to the above components and amounts. The toner 2 was obtained in the same manner as in Toner Production Example 1.
The particle diameter of the toner 2 was measured with a Coulter counter. The ratio <GSDp / GSDv> to the number average particle size distribution index GSDp was 1.02. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 24.8 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 9.5%, and the maximum endothermic value of the release agent contained in the toner is 91. The endothermic area attributable to the low molecular weight component (endothermic amount of 85 ° C. or less based on the endothermic peak area / total endothermic amount based on the endothermic peak area) was 11%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 3.4 mPa · s.

(Toner Production Example 3)
-Resin fine particle dispersion 1: 359 parts by weight-Colorant dispersion 4: 19 parts by weight Toner production example 1 except that the resin fine particle dispersion and the colorant dispersion are changed to the above components and blending amounts. The toner 3 was obtained in the same manner as described above.
The particle size of the toner 3 was measured with a Coulter counter. The volume average particle size was 5.88 μm, the volume average particle size distribution index GSDv was 1.25, the number average particle size distribution index GSDp was 1.26, The ratio <GSDp / GSDv> to the number average particle size distribution index GSDp was 1.01. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 22 atm%. The content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 9.2%, and the maximum endothermic value of the release agent contained in the toner is 91. The endothermic area due to the low molecular weight component (endothermic amount of 85 ° C. or less based on the endothermic peak area / total endothermic amount based on the endothermic peak area) was 12.5%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 3.4 mPa · s.

(Toner Production Example 4)
-Resin fine particle dispersion 1: 360 parts by weight-Release agent dispersion 2: 24 parts by weight Toner Production Example 1 except that the resin fine particle dispersion and the release agent dispersion were changed to the above components and amounts. The toner 4 was obtained in the same manner as described above.
When the particle size of the toner 4 was measured with a Coulter counter, the volume average particle size was 5.92 μm, the volume average particle size distribution index GSDv was 1.26, the number average particle size distribution index GSDp was 1.27, and the volume average particle size distribution index GSDv. The ratio <GSDp / GSDv> to the number average particle size distribution index GSDp was 1.01. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopy, and found to be 26 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 9.2%, and the maximum endothermic value of the release agent contained in the toner is 88%. The endothermic area attributable to the low molecular weight component (the endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) was 15.8%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 3.9 mPa · s.

(Toner Production Example 5)
-Resin fine particle dispersion 1: 360 parts by weight-Release agent dispersion 3: 24 parts by weight Toner production example 1 except that the resin fine particle dispersion and the release agent dispersion were changed to the above components and amounts. The toner 5 was obtained in the same manner as described above.
The particle diameter of the toner 5 was measured with a Coulter counter. The ratio <GSDp / GSDv> to the number average particle size distribution index GSDp was 1.02. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 24 atm%. The content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 9.3%, and the maximum endothermic value of the release agent contained in the toner is 104%. The endothermic area attributable to the low molecular weight component (the endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) was 3.8%. Further, the viscosity ηs140 of the release agent in the toner measured with an E-type viscometer was 3.5 mPa · s.

(Toner Production Example 6)
-Resin fine particle dispersion 1: 344 parts by weight-Release agent dispersion 1:40 parts by weight Toner production example 1 except that the resin fine particle dispersion and the release agent dispersion were changed to the above components and amounts. The toner 6 was obtained in the same manner as described above.
When the particle size of the toner 6 was measured with a Coulter counter, the volume average particle size was 5.85 μm, the volume average particle size distribution index GSDv was 1.23, the number average particle size distribution index GSDp was 1.24, and the volume average particle size distribution index GSDv. The ratio <GSDp / GSDv> to the number average particle size distribution index GSDp was 1.01. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 42 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 16.2%, and the maximum endothermic value of the release agent contained in the toner is 91. Further, the endothermic area attributable to the low molecular weight component (the endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) was 12.2%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 3.1 mPa · s.

(Toner Production Example 7)
-Resin fine particle dispersion 1: 376 parts by weight-Release agent dispersion 1:14 parts by weight Toner production example 1 except that the resin fine particle dispersion and the release agent dispersion were changed to the above components and amounts. The toner 7 was obtained in the same manner as described above.
When the particle size of the toner 7 was measured with a Coulter counter, the volume average particle size was 5.95 μm, the volume average particle size distribution index GSDv was 1.25, the number average particle size distribution index GSDp was 1.25, and the volume average particle size distribution index GSDv The ratio <GSDp / GSDv> to the number average particle size distribution index GSDp was 1.00. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 10 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 5.2%, and the maximum endothermic value of the release agent contained in the toner is 91%. Further, the value of the endothermic area due to the low molecular weight component (the endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) was 12%. Further, the viscosity ηs140 of the release agent in the toner measured with an E-type viscometer was 3.3 mPa · s.

(Toner Production Example 8)
-Resin fine particle dispersion 1: 270 parts by weight Toner Production Example 1 except that the resin fine particle dispersion was changed to the above-mentioned components and blending amounts, held at 50 ° C for 60 minutes, and then added 45 parts by weight of the resin fine particle dispersion 2 . The toner 8 was obtained in the same manner as described above.
The particle diameter of the toner 8 was measured with a Coulter counter. The ratio <GSDp / GSDv> to the number average particle size distribution index GSDp was 1.00. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 15 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 9.3%, and the maximum endothermic value of the release agent contained in the toner is 91%. Further, the value of the endothermic area due to the low molecular weight component (the endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) was 12.3%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 3.3 mPa · s.

(Toner Production Example 9)
-Resin fine particle dispersion 1: 376 parts by weight-Release agent dispersion 4: 14 parts by weight Toner production example 1 except that the resin fine particle dispersion and the release agent dispersion were changed to the above components and amounts. The toner 9 was obtained in the same manner as described above.
The particle diameter of the toner 9 was measured with a Coulter counter. The ratio <GSDp / GSDv> to the particle size distribution index GSDp was 1.00. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 9 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 5.8%, and the maximum endothermic value of the release agent contained in the toner is 109. Further, the value of the endothermic area due to the low molecular weight component (the endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) was 3.2%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 5.2 mPa · s.

(Toner Production Example 10)
-Resin fine particle dispersion 1: 344 parts by weight-Release agent dispersion 5: 40 parts by weight Toner production example 1 except that the resin fine particle dispersion and the release agent dispersion were changed to the above components and amounts. The toner 10 was obtained in the same manner as described above.
The particle diameter of the toner 10 was measured with a Coulter counter. The ratio <GSDp / GSDv> to the average particle size distribution index GSDp was 1.0. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopy, and found to be 41 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 16.1%, and the maximum endothermic value of the release agent contained in the toner is 77. The endothermic area due to the low molecular weight component (the endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) was 88%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 1.3 mPa · s.

(Toner Production Example 11)
Resin fine particle dispersion 2: 180 parts by weight Toner production example 1 except that the resin fine particle dispersion was changed to the above components and blending amounts. The toner 11 was obtained in the same manner as described above.
When the particle diameter of the toner 10 was measured with a Coulter counter, the volume average particle diameter was 5.96 μm, the volume average particle size distribution index GSDv was 1.25, the number average particle size distribution index GSDp was 1.25, and the volume average particle size distribution index GSDv was a number. The ratio <GSDp / GSDv> to the average particle size distribution index GSDp was 1.0. Further, the amount of the release agent present on the toner surface was measured by X-ray photoelectron spectroscopic analysis and found to be 23 atm%. Further, the content of the release agent contained in the toner obtained based on the maximum intensity of the endothermic peak obtained by differential thermal analysis is 9.0%, and the maximum endothermic value of the release agent contained in the toner is 91%. Further, the value of the endothermic area due to the low molecular weight component (the endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) was 12.1%. Further, the viscosity ηs140 of the release agent in the toner measured using an E-type viscometer was 3.1 mPa · s.

-Addition of external additives and preparation of developer-
To 50 parts by weight of the prepared toner, 1.0 part by weight of hydrophobic silica (TS720: manufactured by Cabot) and 2.0 parts by weight of hydrophobic silica (X24: manufactured by Shin-Etsu Chemical) are added and blended in a sample mill. did. This is weighed so that the toner concentration is 5% by weight with respect to a ferrite carrier having an average particle diameter of 50 μm coated with 1% by weight of methacrylate (manufactured by Soken Chemical Co., Ltd.), and stirred and mixed in a ball mill for 5 minutes to adjust the developer. Thus, developers 1 to 11 were obtained.

<Example 1>
Using an image forming apparatus (manufactured by Fuji Xerox Co., Ltd., DocuCenter Color 400 modified machine), an OHP sheet (Fuji Xerox Co., Ltd., V507) is used as a fixing substrate, developer 1 is used as a developer, and toner loading is 13.0 g / The toner image was transferred onto the OHP sheet after adjusting to m ² .
Next, the OHP sheet on which the toner image was transferred was fixed using an external fixing device capable of oilless fixing, with a nip width of 6.5 mm, a fixing temperature of 110 ° C., and a passing speed of 50 mm / sec.

The release agent layer thickness on the image formed on the OHP sheet determined by SEM observation with the magnification set to 500 times is 1.3 μm, and the surface of the image formed on the OHP sheet determined from the Gloss meter The gloss was 107%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 24%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 21%, | Ha−Hb | Was 3%.

Moreover, as a result of evaluating the contact marks of the pinch rolls and the like at the time of discharge by the following four evaluation criteria of G1 to G4, it was G4, and it was confirmed that no roll contact marks were generated. Further, it was confirmed that the fixing machine had good peelability and peeled without any resistance.
In addition, the evaluation criteria of the roll contact trace are as follows, and G2 or more was set as an allowable range.
-Evaluation criteria for roll contact marks-
G4: No roll contact trace is observed when | Ha-Hb | is in the range of 0-4. G3: | Ha-Hb | Roll contact traces are slightly observed when Ha-Hb | is greater than 6 and less than or equal to 8 G1: | Ha-Hb | exceeds 8 and roll contact traces are remarkably observed.

<Example 2>
Fixing was performed in the same manner as in Example 1 except that Developer 2 was used instead of Developer 1. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 1.2 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The gloss was 104%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 25%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 22%, | Ha−Hb | Was 3%, and it was confirmed that contact marks such as pinch rolls at the time of discharge were G4 in a four-step evaluation and did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance.

<Example 3>
Fixing was performed in the same manner as in Example 1 except that Developer 3 was used instead of Developer 1. The release agent layer thickness on the image formed on the OHP sheet determined by SEM observation with the magnification set to 500 times is 1.4 μm, and the surface of the image formed on the OHP sheet determined from the Gloss meter The gloss was 106%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 20%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 18%, | Ha−Hb | Was 2%, and the contact mark of the pinch roll or the like at the time of discharge was G4 in a four-step evaluation, and it was confirmed that it did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance.

<Example 4>
Fixing was performed in the same manner as in Example 1 except that the fixing temperature was 100 ° C. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 0.8 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The gloss was 100%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 22%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 17%, | Ha−Hb | Was 5%, and the contact traces of pinch rolls and the like during discharge were G3 in a four-step evaluation, and it was confirmed that they did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance.

<Example 5>
Fixing was performed in the same manner as in Example 1 except that the fixing temperature was 90 ° C. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 0.6 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The gloss was 86%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 26%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 19%, | Ha−Hb | Was 7%, and it was confirmed that contact marks such as pinch rolls at the time of discharge were G2 in a four-step evaluation and did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance.

<Example 6>
Fixing was performed in the same manner as in Example 1 except that Developer 4 was used instead of Developer 1. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 0.9 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The gloss was 103%.
The haze (cloudiness) Ha of the area in contact with the discharge roll obtained from the haze meter is 16%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 11%, | Ha−Hb | Was 5%, and the contact mark of the pinch roll or the like at the time of discharge was G3 in a four-step evaluation, and it was confirmed that it did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance.

<Example 7>
Fixing was performed in the same manner as in Example 1 except that Developer 5 was used instead of Developer 1. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 1.5 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The gloss was 99%.
The haze (cloudiness) Ha of the area in contact with the discharge roll obtained from the haze meter is 29%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 23%, | Ha−Hb | Was 6%, and the contact traces of pinch rolls and the like during discharge were G3 in a four-step evaluation, and it was confirmed that they did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance.

<Example 8>
Fixing was performed in the same manner as in Example 1 except that Developer 6 was used instead of Developer 1. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 2.4 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The gloss was 101%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 27%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 20%, | Ha−Hb | Was 7%, and it was confirmed that contact marks such as pinch rolls at the time of discharge were G2 in a four-step evaluation and did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance.

<Example 9>
Fixing was performed in the same manner as in Example 1 except that Developer 7 was used instead of Developer 1. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 0.3 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The glossiness was 113%.
The haze (cloudiness) Ha of the area in contact with the discharge roll obtained from the haze meter is 17%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 11%, | Ha−Hb | Was 6%, and the contact traces of pinch rolls and the like during discharge were G3 in a four-step evaluation, and it was confirmed that they did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance.

<Example 10>
Fixing was performed in the same manner as in Example 1 except that Developer 8 was used instead of Developer 1. The release agent layer thickness on the image formed on the OHP sheet determined by SEM observation with the magnification set to 500 times is 1.0 μm, and the surface of the image formed on the OHP sheet determined from the Gloss meter The gloss was 95%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 23%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 16%, | Ha−Hb | Was 7%, and the contact traces of pinch rolls and the like during discharge were G2 in a four-step evaluation, and it was confirmed that they did not occur. Further, the releasability of this fixing machine was good, and it was confirmed that the fixing machine peeled off without any resistance. Furthermore, the transparency of the image formed on the OHP sheet was excellent, and a transmission image without turbidity was confirmed.

<Comparative Example 1>
Fixing was performed in the same manner as in Example 1 except that Developer 9 was used instead of Developer 1. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 0.4 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The gloss was 94%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 33%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 24%, | Ha−Hb | Was 9%, and the contact mark of the pinch roll or the like at the time of discharge was G1 in a four-step evaluation, and it was confirmed that this occurred.

<Comparative example 2>
Fixing was performed in the same manner as in Example 1 except that the developer 10 was used instead of the developer 1. The release agent layer thickness on the image formed on the OHP sheet obtained by SEM observation with the magnification set to 500 times is 2.3 μm, and the surface of the image formed on the OHP sheet obtained from the Gloss meter The gloss was 116%.
The haze (cloudiness) Ha of the area in contact with the discharge roll determined from the haze meter is 20%, and the haze (cloudiness) Hb of the area not in contact with the discharge roll is 9%, | Ha−Hb | Was 11%, and the contact mark of the pinch roll or the like at the time of discharge was G1 in a four-step evaluation, and it was confirmed that this occurred.
<Comparative Example 3>
Fixing was attempted in the same manner as in Example 1 except that the developer 11 was used in place of the developer 1, but a cold offset was caused and an evaluable fixed image could not be obtained.

  The results are shown in Table 1.

It is a schematic diagram for demonstrating the analysis method of the graph obtained by the differential thermal analysis of a mold release agent.

Claims (3)

A fixing step in which a toner image formed using a toner containing at least a binder resin, a colorant, and a release agent is fixed on a fixing substrate by a fixing device to form an image;
A discharging step of discharging the fixing substrate on which the image has been formed to the outside of the fixing device by conveying at least a surface of the fixing substrate on which the image is formed and a discharge roll; In an image forming method including:
An image forming method characterized in that the binder resin contains a crystalline resin and satisfies the following formulas (1) to (3) when an image is formed using a transparent sheet as the fixing substrate.
Formula (1) 10% ≦ Ha ≦ 30%
Formula (2) 10% ≦ Hb ≦ 30%
Formula (3) 0.3% ≦ | Ha−Hb | ≦ 8%
[In the formulas (1) to (3), Ha represents the haze (cloudiness) of the area in contact with the discharge roll in the image forming area of the transparent sheet after the discharge step, and Hb The haze (cloudiness) of the area | region which did not contact | abut the said discharge roll in the image formation area of the said transparent sheet after passing through the said discharge process is represented. ]   [1] The endothermic maximum value obtained from the differential thermal analysis of the release agent is in the range of 85 to 105 ° C., and [2] the ratio of the endothermic amount based on the area of the endothermic peak obtained by the differential thermal analysis ( The endothermic amount of 85 ° C. or less based on the endothermic peak area / the total endothermic amount based on the endothermic peak area) is in the range of 5 to 15%, and [3] based on the maximum intensity of the endothermic peak. 2. The image forming method according to claim 1, wherein the required content of the release agent contained in the toner is in the range of 6 to 15% by weight.   In the toner, a flocculant is added to a mixed solution in which at least a resin fine particle dispersion in which crystalline resin fine particles of 1 μm or less are dispersed, a colorant dispersion, and a release agent dispersion are mixed to form agglomerated particles. 3. The image according to claim 1, wherein the image is produced through an aggregation step to be formed and a fusion step in which the aggregated particles are heated to a melting point or higher of the crystalline resin fine particles to be fused and united. Forming method.

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