JP2002351140A - Method for producing electrostatic image developing toner and image forming method using the toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel production method for producing a chemical toner using a polyester resin having a high particle size distribution and a sharp particle size distribution as a binder resin without emulsification loss. Further, the present invention provides a novel production method which does not use an organic solvent for eliminating residual volatile components in a toner. A toner raw material containing at least a polyester resin is heated and melted to obtain a melt of the toner raw material. And then emulsifying the melt in an aqueous medium to form fine resin particles, then aggregating the fine resin particles and further fusing to produce an aggregate of the fine resin particles. The method for producing a toner for developing an electrostatic image described above is a means for solving the problem.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner for developing an electrostatic image, which is suitably used for an electrophotographic copying machine, a printer, a facsimile and the like, and is also used for a toner jet printer and the like. The present invention relates to an image forming method.

[0002]

2. Description of the Related Art In recent years, in electrophotographic copiers, printers, and fax machines, toners have been used to further improve the quality of printed images or to reduce machine cost, downsizing, power saving, and resource saving. The following needs are increasing. (1) Smaller toner particle size for improving the resolution and gradation of printed images, thinning the toner layer, reducing the amount of waste toner, reducing the amount of toner consumed per page, etc. Lowering the fixing temperature to reduce power consumption (3) Oil-less fixing for simplification of machines, etc. (4) Improvement of hue, transparency and gloss in full-color images (5) Adverse effects on human health VOC (volatile organic compound) reduction at the time of fixing, which may give rise to such problems.

[0003] It is basically possible to reduce the particle size of the powder toner by a pulverization method which has been used for a long time.
As the particle size decreases, the ratio of a release agent such as a colorant or wax exposed on the surface of the toner particles increases, so that charge control becomes difficult. Due to the irregular shape of the toner particles, powder fluidity deteriorates. In addition, problems such as an increase in the energy cost required for production occur, and it is practically difficult to sufficiently satisfy the above-mentioned needs with the toner obtained by the pulverization method.

[0004] From such a background, a toner conventionally produced by a polymerization method or an emulsion dispersion method (hereinafter referred to as a chemical toner).
Has been actively developed. Various methods are known for the toner obtained by the polymerization method. Among them, among them, a monomer, a polymerization initiator, a colorant, a charge control agent, and the like are added to an aqueous medium containing a dispersion stabilizer while stirring to obtain oil droplets. A suspension polymerization method for forming toner particles and then performing a polymerization reaction by raising the temperature to obtain toner particles is widely known. Alternatively, an association method has been proposed in which fine particles are formed by emulsion polymerization or suspension polymerization, the fine particles are aggregated, and the aggregated fine particles are fused to obtain toner particles. However, in such a polymerization method or an association method using fine particles produced by the polymerization method, although there is no problem in reducing the particle diameter of the toner particles, the main component of the binder resin is limited to a vinyl polymer capable of radical polymerization. Therefore, it is not possible to produce a toner using a polyester resin or an epoxy resin suitable for a color toner or the like. In the polymerization method,
There is also a problem that it is difficult to reduce VOCs (volatile organic compounds composed of unreacted monomers and the like), and improvement is desired.

On the other hand, a method for producing a toner by the emulsification dispersion method is as follows.
JP-A-5-66600 and JP-A-8-21655
As disclosed in Japanese Unexamined Patent Application Publication No. H10-163, a method in which a mixture of a binder resin and a colorant and the like is mixed with an aqueous medium and emulsified to obtain toner particles. In addition to easily adapting to diameter and spheroidization, the range of choice of binder resin is wider than that of the polymerization method, it is easy to reduce residual monomer, and the concentration of colorants etc. from low to high concentration It has the advantage that it can be changed arbitrarily.

Incidentally, as a binder resin for toner having a relatively low fixing temperature and which tends to be sharply melted at the time of fixing and the image surface is likely to be smooth, a polyester resin is preferable to a styrene-acrylic resin. Is preferably a polyester resin having excellent flexibility. However, as described above, the polymerization method cannot produce toner particles containing a polyester resin as a main component of the binder resin. Therefore, in recent years, attention has been focused on producing a small particle size toner using a polyester resin as a binder resin by an emulsion dispersion method.

However, in each of the publications for producing a toner by the above-mentioned emulsification dispersion method, there is a technical improvement as described below. Since a solvent is used, a process for removing and recovering the organic solvent is newly required, and a load is imposed on wastewater treatment measures. Since the generation of fine particles is inevitable and the loss of emulsification occurs, the yield of the toner is reduced and the productivity is deteriorated.

[0008] As a production method for solving such problems, for example, in Japanese Patent Application Laid-Open Nos. 10-020552 and 11-007156, after emulsifying and dispersing using a polyester resin as a binder resin, A method of producing toner particles by aggregating the obtained fine particles and further fusing them is proposed. According to such a production method, it is considered that ultrafine particles are not generated, and therefore, there is no emulsification loss, and it is possible to produce a classification-free toner having a sharp particle size distribution. Is an essential component,
New measures or equipment investment are required, such as removal and recovery of organic solvents, load on wastewater, removal of residual solvents in toner particles, and the like, resulting in high toner production costs.

As a method for fixing a toner image, a heat roll fixing method is widely and generally used. In this case, good fixing properties and offset resistance are also important characteristics required for the toner. . In recent copiers and printers, the processing speed has been increased, so that the fixing temperature has become lower and the fixing time has become shorter. Furthermore, in order to achieve simplification of the machine structure and ease of maintenance, an oil-less fixing method in which oil for preventing offset is not applied to the fixing heat roll has been developed, and a demand for a toner suitable for this has been growing. . The prior arts described so far do not sufficiently disclose techniques for lowering the fixing temperature or widening the anti-offset temperature range. Therefore, at present, there is no technique for producing a chemical toner which has no emulsification loss, has a sharp particle size distribution, and can provide a toner suitable for an oilless fixing system.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to bind a polyester resin having no emulsification loss, a high yield, and a sharp particle size distribution. It is an object of the present invention to provide a novel production method for producing a resinous chemical toner. Another object of the present invention is to provide a novel production method that does not use an organic solvent for eliminating residual volatile components in a toner. Another object of the present invention is to produce a novel chemical toner suitable for a so-called oilless fixing method, which has a good fixing / offset temperature range without using an offset prevention liquid, as a toner used in a heat roll fixing method. It is to provide a method. Another object of the present invention is to provide an image forming method using the electrostatic image developing toner obtained by the manufacturing method which solves the above-mentioned problems.

[0011]

Means for Solving the Problems The present inventors formed resin fine particles by emulsifying a resin melt composed of a toner raw material containing at least a polyester resin in an aqueous medium without using any organic solvent. The present inventors have found that the above problems can be solved by aggregating and further fusing the obtained resin fine particles, thereby completing the present invention.

That is, according to the present invention, a toner raw material containing at least a polyester resin is heated and melted to produce a melt of the toner raw material, and then the melt is emulsified in an aqueous medium to obtain fine resin particles. The method of manufacturing a toner for developing an electrostatic image is characterized in that an aggregate of the resin fine particles is manufactured by agglomerating and further fusing the resin fine particles. .

Further, the present invention provides a method for forming an electrostatic charge image on an electrostatic image holding member, and using the electrostatic charge image with a developer comprising an electrostatic charge image developing toner carried on a developer carrying member. Developing, transferring the toner image formed on the electrostatic image holding member onto a transfer material, and thermally fixing the toner image on the transfer material with a heat roll to thereby thermally fix the toner image on the transfer material. In an image forming method for forming an image, an image forming method using the electrostatic image developing toner manufactured by the above manufacturing method is provided as a means for solving the above problem.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The electrostatic image developing toner of the present invention contains at least a binder and a colorant, and the binder resin is a polyester resin. The polyester resin used as the binder resin is synthesized by dehydrating and condensing a polybasic acid and a polyhydric alcohol.

Examples of polybasic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, and naphthalenedicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, Aliphatic carboxylic acids such as alkenylsuccinic anhydride and adipic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid; These polybasic acids can be used alone or in combination of two or more. Among these polybasic acids, it is preferable to use aromatic carboxylic acids.

Examples of the polyhydric alcohol include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane, and pentaerythritol; cyclohexanediol And alicyclic diols such as cyclohexanedimethanol and hydrogenated bisphenol A; and aromatic diols such as ethylene oxide adduct of bisphenol A and propylene oxide adduct of bisphenol A. These polyhydric alcohols can be used alone or in combination of two or more. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.

Incidentally, a monocarboxylic acid and / or a monoalcohol is further added to the polyester resin obtained by polycondensation of the polyvalent carboxylic acid and the polyhydric alcohol,
The hydroxyl value and / or carboxyl group at the polymerization end can be esterified to adjust the acid value of the polyester resin. Examples of the monocarboxylic acid used for such a purpose include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, and propionic anhydride. Further, as the monoalcohol, for example, methanol, ethanol, propanol, octanol,
Examples include 2-ethylhexanol, trifluoroethanol, trichloroethanol, hexafluoroisopropanol, and phenol.

The polyester resin can be produced by subjecting the above-mentioned polyhydric alcohol and polyvalent carboxylic acid to a condensation reaction according to a conventional method. For example, the polyhydric alcohol and the polyhydric carboxylic acid are blended in a thermometer, a stirrer, a reaction vessel equipped with a falling condenser, and heated at 150 to 250 ° C. in the presence of an inert gas such as nitrogen. By continuously removing low-molecular compounds produced as by-products from the reaction system, stopping the reaction when a predetermined physical property value is reached, and cooling,
The desired reactant can be obtained.

The synthesis of such a polyester resin can be carried out by adding a catalyst. Examples of the esterification catalyst used include organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. When the carboxylic acid component used is a lower alkyl ester, a transesterification catalyst can be used. Examples of the transesterification catalyst include metal acetates such as zinc acetate, lead acetate and magnesium acetate; metal oxides such as zinc oxide and antimony oxide; and metal alkoxides such as tetrabutyl titanate. The addition amount of the catalyst is preferably in the range of 0.01 to 1% by weight based on the total amount of the raw materials.

In order to produce a branched or crosslinked polyester resin in such a polycondensation reaction, a polybasic acid having three or more carboxyl groups in one molecule or an anhydride thereof, and / or A polyhydric alcohol having three or more hydroxyl groups in one molecule may be used as an essential raw material for synthesis.

The polyester resin thus obtained preferably has a value measured by a constant load extrusion type capillary rheometer (hereinafter referred to as a flow tester) in the following range. That is, the outflow starting temperature Tfb by the flow tester is in the range of 80 ° C. to 120 ° C., T1 / 2
Temperature range from 120 ° C to 180 ° C, outflow end temperature Tend
Is in the range of 130 ° C to 210 ° C. By using a polyester resin having such a flow tester value, the toner for developing an electrostatic image of the present invention has good oil-less fixability. Further, the glass transition temperature (Tg) is preferably from 40 to 75 ° C.

Outflow starting temperature Tfb by flow tester,
In the present invention, the T1 / 2 temperature and the outflow end temperature Tend are determined using a flow tester (CFT-500) manufactured by Shimadzu Corporation. As shown in FIG. 1A, this flow tester has a cylinder 2 having a nozzle 1 having a nozzle diameter D of 1.0 mmΦ and a nozzle length (depth) L of 1.0 mm.
Is filled with resin 3 (weight 1.5 g), a load of 10 kg per unit area (cm ² ) is applied from the side opposite to the nozzle 1, and heated at a rate of 6 ° C./min. ,
It is obtained by measuring the stroke S of the load surface 4 (the sink value of the load surface 4). That is, the relationship between the temperature and the stroke S is determined as shown in FIG. 1 (b), and when the flow of the resin 3 from the nozzle 1 starts, the stroke S suddenly increases and the curve rises. Let Tfb be the temperature, and let Tend be the temperature at which the outflow of the resin 3 from the nozzle 1 is almost finished and the curve is bent. The temperature at S1 / 2, which is an intermediate value between the stroke Sfb at Tfb and the stroke Send at Tend, is defined as T1 / 2 temperature.

In the measurement by the temperature raising method using this apparatus, the test is carried out while raising the temperature at a constant rate with the passage of the test time, so that the sample goes from the solid region to the transition region, through the rubbery elastic region to the flow region. The process leading up to this can be measured continuously. With this device, the shear rate and the viscosity at each temperature in the flow region can be easily measured.

The outflow starting temperature Tfb is an index of the sharp melt property and the low-temperature fixability of the polyester resin.
If the temperature is too high, the low-temperature fixability deteriorates, and cold offset easily occurs. Further, if the temperature is too low, the storage stability decreases, and hot offset easily occurs. Therefore, the outflow start temperature Tfb of the toner for developing an electrostatic image of the present invention is more preferably from 90 ° C to 115 ° C, and particularly preferably from 90 ° C to 110 ° C.

Further, the melting temperature T of the toner by the 1/2 method
The 1/2 and the outflow end temperature Tend are indicators of the hot offset resistance. If both are too high, the solution viscosity increases, and the particle size distribution during particle formation deteriorates. In addition, if both are too low in temperature, offset tends to occur and the practicability is reduced. Therefore, 1/2
The melting temperature T1 / 2 by the method is preferably 120 ° C. to 180 ° C., more preferably 130 ° C. to 160 ° C., and the outflow end temperature Tend is preferably 130 ° C. to 210 ° C.
30 ° C to 180 ° C is more preferred. Tfb, T1 / 2,
By setting Tend within the above range, fixing can be performed in a wide temperature range.

The above-mentioned polyester resin contains a crosslinked polyester resin, and the binder resin has a tetrahydrofuran-insoluble content in the range of 0.1 to 20% by weight, more preferably 0.2 to 10% by weight. Good hot offset resistance can be obtained by using a polyester resin having a tetrahydrofuran-insoluble content of 0.1 to 20% by weight as the binder resin. It can be secured and is preferable. 0.
If it is less than 1% by weight, the effect of improving hot offset resistance is insufficient, which is not preferable. If the content is more than 20% by weight, the solution viscosity becomes too high, the fixing start temperature becomes high, and the balance of fixing property is lost, which is not preferable. Also,
Since the sharp melt property is impaired, the transparency, color reproducibility, and gloss of a color image are poor, which is not preferable.

The tetrahydrofuran-insoluble content of the binder resin was precisely weighed, 1 g of the resin was added to 40 ml of tetrahydrofuran, completely dissolved, and a funnel (diameter) on which Kiriyama filter paper (No. 3) was placed. 2 g of radiolite (# 700, manufactured by Showa Chemical Co., Ltd.) is spread evenly on a 40 mm) and filtered. The cake is placed on an aluminum Petri dish, and then dried at 140 ° C. for 1 hour, and the dry weight is measured. Then, a value obtained by dividing the amount of the residual resin in the dry weight by the amount of the first resin sample is calculated as a percentage, and this value is defined as the insoluble content.

It is more preferable that the binder resin contains a low-viscosity branched or linear polyester resin. That is, in the polyester resin of the present invention, the binder resin may be composed of one kind of polyester resin, but generally, a high molecular weight and high viscosity crosslinked polyester resin (crosslinked polyester resin)
And a low molecular weight, low viscosity, branched or straight-chain polyester resin can be blended and used for the production of the resin, and also to obtain good fixing start temperature and hot offset resistance. And preferred. In the case of blending, the flow tester value of the blended resin may be within the above numerical range. In the present invention, a crosslinked polyester resin refers to a resin having a component insoluble in tetrahydrofuran, and a branched or linear polyester resin refers to a resin in which an insoluble component is not detected in the above-described method for measuring tetrahydrofuran insoluble component.

In the present invention, a plurality of polyester resins having different melt viscosities can be used as the binder resin.
For example, when using a mixture of a low-viscosity branched or linear polyester resin and a crosslinked polyester resin,
It is more preferable to use a mixture of a branched or linear polyester resin (A) and a crosslinked or branched polyester resin (B) under the following conditions. At this time, the flow tester value of the blended resin preferably falls within the above numerical range.

That is, as the polyester resin (A), the T1 / 2 temperature by a flow tester is 80 ° C. or more,
A glass transition temperature Tg of less than 20 ° C.
° C branched or linear polyester resin, and polyester resin (B) as T1 by flow tester
/ 2 A crosslinked or branched polyester resin having a temperature of 120 ° C. or more and 210 ° C. or less and a glass transition temperature Tg of 50 to 75 ° C., and the weight of the polyester resin (A) and the polyester resin (B) The ratio is
(A) / (B) = 20/80 to 80/20, and the T1 / 2 temperatures were set to T1 / 2 (A) and T1 /
When 2 (B) is used, those having a relationship of 20 ° C. <T1 / 2 (B) −T1 / 2 (A) <100 ° C. are preferably used.

Considering each temperature characteristic by the flow tester, the melting temperature T1 / 2 of the resin (A) by the 1/2 method is considered.
(A) is an index for imparting a sharp melt property and a low-temperature fixing property, and T1 / 2 (A) is 80 to 115 ° C.
Is more preferable, and it is particularly preferable that it is in the range of 90 to 110 ° C.

Resin (A) defined by these properties
Has a low softening temperature.In the fixing process using a heat roll, even if the applied heat energy is reduced by lowering the temperature of the heat roll or increasing the process speed, it sufficiently melts and achieves cold offset resistance and low-temperature fixability. Demonstrates excellent performance.

The melting temperature T1 / of the resin (B) by the 1/2 method
If both 2 (B) and the end-of-flow temperature Tend (B) are too low, hot offset is likely to occur, and if too high, the particle size distribution during particle formation deteriorates and productivity decreases. Therefore, T1 / 2 (B) is 125 ° C. to 2 ° C.
More preferably 10 ° C, 130 ° C to 200 ° C
Is particularly preferred.

Resin (B) defined by these properties
Has a strong rubber elasticity and a high melt viscosity, so the internal cohesive force of the melted toner layer is maintained even during heating and melting in the fixing process, hot offset hardly occurs, and its toughness after fixing Demonstrates excellent friction resistance.

By blending the resin (A) and the resin (B) in a well-balanced manner, it is possible to provide a toner which sufficiently satisfies the anti-offset performance and the low-temperature fixing performance in a wide temperature range.

The weight ratio of resin (A) to resin (B) (A) /
If (B) is too small, it affects the fixability. If (B) is too large, it affects the anti-offset property, so it is preferably 20/80 to 80/20.
The ratio is more preferably 30/70 to 70/30.

The melting temperatures of the resin (A) and the resin (B) according to the を method are T1 / 2 (A) and T1 / 2 (B), respectively.
In order to make it easy to mix uniformly from the viewpoint of compatibility between low-temperature fixing property and anti-offset property, and without causing a problem caused by a difference in viscosity between resins, T1 / 2 (B)
The range of -T1 / 2 (A) is more than 20 ° C, more preferably 90 ° C or less, and particularly preferably more than 20 to 80 ° C or less.

Glass transition temperature (Tg) in the present invention
In the present invention, a differential scanning calorimeter (D
This is a value obtained by using the second run method at a heating rate of 10 ° C. per minute using SC-50).

When the Tg of the polyester resin (A) is less than 40 ° C. or the Tg of the polyester resin (B) is less than 50 ° C., the obtained toner blocks during storage or in a developing machine (the toner particles are aggregated). Phenomenon
This is not preferable because it is easy to cause a problem. On the other hand, if the Tg of the polyester resin (A) exceeds 70 ° C., or if the Tg of the polyester resin (B) exceeds 75 ° C., the fixing temperature of the toner becomes undesirably high. As described above, by using the polyester resin (A) and the polyester resin (B) having the above relationship as the polyester resin serving as the binder resin, the obtained toner has better fixability, and is preferable. .

Further, the binder resin composed of a polyester resin has a weight average molecular weight of 30,000 or more, preferably 37,000 or more, as determined by gel permeation chromatography (GPC) of a tetrahydrofuran (THF) -soluble component. 000 or more, weight average molecular weight (Mw)
/ The number ratio of components having a number average molecular weight (Mn) of 12 or more, preferably 15 or more, and a molecular weight of 600,000 or more is 0.1% or less.
The area ratio of the component having a molecular weight of 3% or more, preferably 0.5% or more and 10,000 or less is 20 to 80%, preferably 30 to 7%.
It is preferable to satisfy the condition of 0% in order to obtain good fixability. When a plurality of resins are blended, the final GPC measurement result of the resin mixture may be within the above numerical range.

In the polyester resin used in the production method of the present invention, a high molecular weight component having a molecular weight of 600,000 or more has a function of securing hot offset resistance. On the other hand, a low molecular weight component having a molecular weight of 10,000 or less is effective for lowering the melt viscosity of the resin, developing a sharp melt property and lowering the fixing start temperature, and may contain a resin component having a molecular weight of 10,000 or less. preferable. In order to obtain good thermal characteristics such as low-temperature fixing, hot offset resistance and transparency in the oilless fixing system, it is preferable that the binder resin has such a broad molecular weight distribution. In addition, in granulation of fine particles by an emulsification dispersion method without using a solvent, it is preferable to include a low molecular weight component from the viewpoint of lowering the melt viscosity of the resin.

Here, the molecular weight of the THF-soluble matter of the binder resin is determined by filtering the THF-soluble matter through a 0.2 μm filter, and then using GPC HLC-8120 manufactured by Tosoh and column “TSKgel SuperHM-M” manufactured by Tosoh. (15cm)
Are used in a THF solvent (flow rate 0.6 ml / min,
At a temperature of 40 ° C.), and the molecular weight was calculated by using a molecular weight calibration curve prepared with a monodispersed polystyrene standard sample.

The acid value of the polyester resin (1 g of resin)
(The number of mg of KOH required to neutralize the toner) is such that the molecular weight distribution as described above is easily obtained, the granulation of fine particles is easily ensured by emulsification and dispersion with no solvent, and the environmental stability of the obtained toner. (Stability of the charging property when the temperature and humidity are changed) is easy to maintain, and the range of 1 to 20 mgKOH / g is preferable. In addition,
As described above, the acid value of the polyester resin may vary depending on the number of raw materials other than adding a monocarboxylic acid and / or a monoalcohol to the polyester resin obtained by polycondensation of a polycarboxylic acid and a polyhydric alcohol. It can be adjusted by controlling the carboxyl group at the terminal of the polyester by the mixing ratio and the reaction rate of the basic acid and the polyhydric alcohol. Alternatively, a polyester having a carboxyl group in the main chain can be formed by using trimellitic anhydride as the polybasic acid component.

In the production method of the present invention, it is preferable to contain a release agent. In this case, the release agent may be a hydrocarbon wax such as polypropylene wax, polyethylene wax, Fischer-Tropsch wax, or a synthetic ester wax. , A wax selected from the group of natural ester waxes such as carnauba wax and rice wax. Specially, it is obtained from natural ester waxes such as carnauba wax and rice wax, polyhydric alcohols and long-chain monocarboxylic acids. If it is less than 1% by weight, the releasability tends to be insufficient, and if it exceeds 40% by weight, the wax tends to be exposed on the surface of the toner particles, and the chargeability and storage stability tend to decrease.

The production method of the present invention preferably contains a charge control agent. The positively chargeable charge control agent is not particularly limited, and a known and commonly used nigrosine dye, a quaternary ammonium compound, an onium compound, a triphenylmethane compound and the like can be used for toner. In addition, compounds containing a basic group such as an amino group, an imino group, or an N-hetero ring, such as a styrene acrylic resin containing a tertiary amino group, also have an effect as a positively chargeable charge controlling agent. The control agent can be used alone or in combination with the positively chargeable charge control agent. Depending on the application, a small amount of a negative charge control agent such as an azo dye metal complex or a salicylic acid derivative metal complex salt may be used in combination with these positively chargeable charge control agents. Examples of the negatively chargeable charge control agent include heavy metals such as trimethylethane dyes, salicylic acid metal complex salts, benzylic acid metal complex salts, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex salt azo dyes, and azochrome complexes. Acidic dyes, phenol-based condensates of calixarene type, cyclic polysaccharides, resins containing a carboxyl group and / or a sulfonyl group, and the like.

The content of the charge control agent is preferably from 0.01 to 10% by weight. In particular, it is preferably 0.1 to 6% by weight.

The colorant used in the production method of the present invention is not particularly limited, and known and commonly used colorants are used, and pigments are particularly preferably used. As a black pigment,
For example, carbon black, cyanine black, aniline black, ferrite, magnetite and the like can be mentioned. In addition, a mixture of the following chromatic pigments so as to be black can also be used.

Examples of the yellow pigment include, for example, graphite, zinc yellow, cadmium yellow, yellow iron oxide, loess, titanium yellow, naphthol yellow S, Hansa yellow 10G, Hansa yellow 5G, Hansa yellow G, Hansa yellow GR, Hansa yellow. A, Hansa Yellow RN, Hansa Yellow R, Pigment Yellow L, Benzidine Yellow, Benzidine Yellow G, Benzidine Yellow GR,
Permanent Yellow NCG, Vulcan First Yellow 5G, Vulcan First Yellow R, Quinoline Yellow Lake, Anslagen Yellow 6GL, Permanent Yellow FGL, Permanent Yellow H10G,
Permanent yellow HR, anthrapyrimidine yellow, other isoindolinone yellow, chromophtal yellow, novo palm yellow H2G, condensed azo yellow, nickel azo yellow, copper azomethine yellow and the like.

Examples of the red pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indaslen brilliant orange RK, indaslen brilliant orange GK, benzidine orange G, permanent red 4R, and permanent red BL. , Permanent red F
5RK, Risor Red, Pyrazolone Red, Watching Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Brilliant Carmine 3B, Rhodamine Lake B, Alizarin Lake, Permanent Carmine FBB, Verinone Orange, Isoindolinone Orange, Ansuanthrone Orange Pyranthrone orange, quinacridone red, quinacridone magenta, quinacridone scarlet, perylene red and the like.

Examples of the blue pigment include cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, fanatone blue 6G, Victoria blue lake, metal-free phthalocyanine blue, copper phthalocyanine blue, fast sky blue, and induslen blue RS. , Indaslen Blue BC, Indico and the like.

The amount of these coloring agents used is 100
The range of 1 to 50 parts by weight per part by weight is preferable,
A range of 5 parts by weight is particularly preferred.

Next, the manufacturing method of the present invention will be described. The production method of the present invention comprises the following steps. First step: A toner raw material containing at least a polyester resin is melt-kneaded, and a melt obtained by heating and melting the kneaded product and an aqueous medium heated to a temperature equal to or higher than the softening point of the resin are optionally applied under pressurized conditions. A second step: dispersing a mixture of the melt and a high-temperature aqueous medium in an aqueous medium by mechanical means while maintaining a temperature equal to or higher than the softening point of the resin to generate fine particles of the melt. A third step: producing resin fine particles by cooling the resin to a temperature lower than the softening point of the resin and lower than the boiling point of water while preventing fusion of the fine particles of the melt under atmospheric pressure. Fourth step: a step of producing an aggregate of the fine resin particles by aggregating and further fusing the fine resin particles. Fifth step: separating and washing the aggregate of the fine resin particles from the aqueous medium, drying and producing a toner Step (in the present invention) The toner in the present invention refers to a dried product of the aggregate of resin fine particles produced in the fourth step).

The melt of the toner raw material in the first step can be obtained by heating the toner raw material containing the polyester resin to a temperature higher than the softening point of the resin.
In this case, as the toner raw material, one or more selected from various colorants, release agents or charge control agents, or other additives can be used together with the polyester resin. In that case, the melt may be produced by heating and melting a material obtained by simply mixing the powdery raw materials, but the polyester used by using a pressure kneader, a heated twin roll, a twin-screw extruder or the like may be used. It is preferable to use a resin which is heated and melted at a temperature higher than the softening point of the resin and lower than the thermal decomposition temperature and kneaded. Raw materials other than the polyester resin, such as a coloring agent, may be melt-kneaded with the polyester resin in advance as a master batch.

The polyester resin used in the present invention is preferably an acidic group-containing polyester resin. A polyester resin which becomes self-water dispersible by neutralizing the acidic group (hereinafter referred to as a self-water dispersible resin). ) Is preferable. The resin having self-water dispersibility increases hydrophilicity by the acidic group being anionic, and can be stably dispersed in an aqueous medium without using a dispersion stabilizer or a surfactant. Examples of the acidic group include acidic groups such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Among them, the carboxyl group is preferable from the viewpoint of the charging characteristics of the toner. Further, the basic substance for neutralization is not particularly limited, for example, sodium hydroxide, potassium hydroxide,
Inorganic bases such as ammonia and organic bases such as diethylamine, triethylamine and isopropylamine are used. Among them, inorganic bases such as ammonia and sodium hydroxide are preferred. In order to stably disperse the colored resin melt in an aqueous medium, fine particles can also be obtained by adding a suspension stabilizer or a surfactant.
However, when used as a toner, the self-water dispersible resin is preferably used because the charging characteristics tend to deteriorate due to the influence of the dispersion stabilizer and the emulsifier.

The aqueous medium used is preferably water, more preferably deionized water.

A dispersion stabilizer, a surfactant or a basic substance may be added to the melt and dispersed in water, but is added to an aqueous medium in consideration of the stability of the resin.

In the second step, the mixture of the melt obtained in the first step and the high-temperature aqueous medium is dispersed in the aqueous medium by mechanical means while maintaining the temperature at or above the softening point of the resin,
This is a step of generating fine particles of the melt. As an apparatus for dispersing the melt in an aqueous medium by mechanical means while maintaining the temperature at or above the softening point of the resin to form fine particles of the melt, for example, a ring-shaped stator having a slit And a ring-shaped rotor having slits, it is preferable to use a high-speed rotation type continuous emulsifying and dispersing machine in which the stator and the rotor are coaxially engaged with each other while maintaining a small interval. . An example of such an apparatus is Cavitron (Eurotech Co., Ltd.). The details of this apparatus and the mechanism of producing resin fine particles by the apparatus are described in JP-A-09-31.
No. 1502, it is possible to obtain the fine particles of the melt without using a solvent by using the apparatus.

In the third step, the aqueous dispersion of the fine particles of the melt obtained from the outlet of the high-speed rotation type continuous emulsifying and dispersing machine as described above collides with the fine particles of the melt produced. While no agglomerates are formed, the mixture is rapidly cooled to a temperature below the boiling point of water and below the glass transition temperature of the resin as quickly as possible.

As a device for rapidly cooling, a commercially available heat exchanger can be used, and cooling is performed while exchanging heat with cooling water. The cooling rate is not particularly limited, but is preferably 10 ° C./sec or more in order to prevent generation of aggregates.

After the polyester resin is rapidly cooled to around the glass transition temperature, the pressure is returned to the atmospheric pressure by a pressure control valve, whereby the fine particles of the melt are solidified and a slurry of resin fine particles is obtained.

The 50% volume average particle size of the resin fine particles is 0.1%.
It is in the range of 1 to 6 μm, more preferably more than 1 μm and 4 μm. Particularly preferred is a range of more than 1 μm and 3 μm. If the thickness is less than 0.1 μm, when a colorant or a release agent is used, the resin is not sufficiently encapsulated by a resin, so that charging characteristics and development characteristics are adversely affected, which is not preferable. Also, if the particle size is large, the particle size of the aggregate of the resin fine particles finally obtained becomes large, so it is necessary to be 6 μm or less. On the other hand, if it is larger than 6 μm, coarse particles are likely to be generated, which is not preferable.

The particle size of the resin fine particles before association in the present invention is a value measured using a 15 μm aperture tube of Multisizer TAII type manufactured by Coulter Inc., USA.

In the fourth step, the resin fine particles obtained in the steps up to the third step are aggregated and further fused to form an aggregate of the resin fine particles to form toner particles having a desired particle diameter. Coagulation / fusion operation is performed by temperature, salt concentration, PH,
By appropriately controlling the stirring conditions and the like, an aggregated / fused body can be obtained.

In the fourth step of the present invention, for example, when resin particles consisting only of a polyester resin are produced by the above steps, a colorant dispersion, a charge control agent dispersion, a release agent dispersion and the like are separately produced. Then, one or more of these dispersions can be added to a slurry in which resin fine particles consisting of only the polyester resin are suspended, and thereafter, an agglomeration / fusion operation can be performed.

Alternatively, even when resin particles comprising a polyester resin and one or more other raw materials for a toner, such as a combination of a polyester resin and a colorant, are produced by the above-described steps, the above-mentioned various dispersions are added to the resin particles. Four steps can be performed. By doing so, it becomes possible to manufacture toner while exposing various additives such as a charge control agent to the surface of the aggregated particles manufactured in the fourth step, and control the surface properties of the toner according to various uses. can do.

The various dispersions used here can be obtained as follows. For example, a nonionic surfactant represented by a polyoxyethylene alkylphenyl ether, an anionic surfactant represented by an alkylbenzene sulfonate, or a cationic surfactant represented by a quaternary ammonium salt is used for each substance. And a surfactant can be added to water and prepared by a mechanical pulverization method using a medium. Alternatively, instead of a surfactant,
Using a self-water dispersible polyester resin, a dispersion can be prepared by the same dispersion means in the presence of a basic neutralizing agent. Also, the coloring pigment, release agent, and charge control agent used here are:
What has been melt-kneaded with a polyester resin in advance may be used. In this case, the degree of exposure of various materials to the particle surface is reduced by the adsorption of the resin, and preferable characteristics in charging characteristics and developing characteristics are provided.

As described above, in the present invention, various embodiments can be taken without departing from the spirit of the invention. Among them, preferred embodiments include the following. Polyester resin and coloring pigment, release agent if necessary,
A method in which the charge control agent is melt-kneaded to produce resin fine particles by the above-described first to third steps, and the aggregation / fusion step is performed. Manufactured by a dispersion of a color pigment, and
If necessary, one or more of the dispersion liquids of the release agent and the charge control agent are separately prepared, and after mixing them, the coagulation
A method of performing a fusion step, melt-kneading a polyester resin and a release agent, producing resin fine particles by the above first to third steps, a dispersion of a colorant, and a dispersion of a charge control agent as necessary. Mix the liquid,
A method of performing the aggregation / fusion process,

In order to maintain good triboelectric charging performance, it is effective to prevent the colorant and the like from being exposed on the surface of the toner particles, that is, to have a toner structure in which the colorant and the like are included in the toner particles. It is. The deterioration of the chargeability due to the reduction in the particle size of the toner is also caused by the fact that a part of the contained colorant and other additives (such as wax) is exposed on the surface of the toner particles. That is, even if the content (% by weight) of the colorant or the like is the same, the surface area of the toner particles increases due to the reduction in the particle size, and the ratio of the colorant or wax exposed on the surface of the toner particles increases. As a result, the composition of the surface of the toner particles changes greatly, and the frictional charging performance of the toner particles changes greatly, making it difficult to obtain proper charging properties.

It is desirable that the resin fine particles of the present invention contain a colorant, a wax, and the like in the binder resin, and a good printed image can be obtained by having such a structure. Whether the colorant, the wax, or the like is not exposed on the surface of the toner particles can be easily determined by, for example, observing the cross section of the particles with a TEM (transmission electron microscope). More specifically, a section obtained by embedding the toner particles in a resin and cutting with a microtome is dyed with ruthenium oxide or the like, if necessary, and observed with a TEM. Can be confirmed.

Therefore, in order to positively include the colorant and the release agent, the above-mentioned method is preferable. However, the fogging method is preferred from the viewpoint of saving labor such as cleaning work by changing colors of manufacturing equipment such as a kneading apparatus. Which method is used, or what combination is used, may be appropriately selected in view of the type of pigment or the required characteristics of the toner.

The resin fine particles formed from the self-water-dispersible resin obtained up to the third step are stably dispersed in the aqueous medium by the action of the electric double layer by the carboxylate. Aggregation can be achieved by adding an acidic substance that breaks the electric double layer or an electrolyte that reduces the electric double layer to an aqueous medium in which resin fine particles are dispersed. Examples of the acidic substance include hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid,
An acid such as oxalic acid is used. Examples of the electrolyte include water-soluble organic and inorganic salts such as sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, sodium chloride, potassium chloride, ammonium chloride, calcium chloride, and sodium acetate. Is used. These substances added for coagulation may be used alone or as a mixture of two or more. Further, the fusion can be performed by heating the aqueous medium to a temperature equal to or higher than the glass transition temperature of the resin.

At this time, in order to prevent the aggregates of the resin fine particles generated by the acidic substance from fusing together to form an aggregate having a target particle diameter or more, an inorganic material represented by hydroxyapatite is used. A dispersion stabilizer or a surfactant may be added. As the surfactant, ionic or nonionic surfactants can be used. Among them, nonionic surfactants are preferable. For example, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene Ethylene sorbitan fatty acid esters and the like can be used. These surfactants may be used alone or in combination of two or more. The nonionic surfactant preferably has a cloud point of 60 ° C. or higher.

Stirring is important for promoting uniform coagulation and fusion. For example, a stirring device, an anchor blade, a turbine blade, and the like as disclosed in Japanese Patent Application Laid-Open No. Hei 9-114135.
Faudler wing, full zone wing, max blend wing,
A corn wing, a helical wing, a double helical wing, a half moon wing, or the like is appropriately selected and used.

The shape of the aggregate of the resin fine particles obtained in the fourth step can be changed from an irregular shape to a spherical shape depending on the degree of fusion. For example, if expressed in average circularity,
It is possible to change from 0.85 to 0.99.
The average circularity can be determined by taking an SEM (scanning electron microscope) photograph of the toner particles obtained by drying the aggregate of the colored resin fine particles, and measuring and calculating the photograph. Since it can be easily obtained by using a flow-type particle image analyzer FPIP-1000 manufactured by Toa Medical Electronics Co., Ltd., in the present invention, the value measured by this apparatus is defined as the average circularity.

In the fifth step, the dispersion liquid of the aggregate of resin fine particles obtained in the fourth step is passed through a wet vibrating sieve to remove dust and coarse particles such as resin pieces and the like.
Alternatively, solid-liquid separation can be performed by a known and commonly used means such as a filter press and a belt filter. Then, the toner particles can be obtained by drying the particles. It is preferable that the toner particles produced by using an emulsifier or a dispersion stabilizer are more thoroughly washed. Since the waste liquid discharged at this time does not contain an organic solvent, the burden of waste liquid treatment is extremely reduced.

As the drying method, any of the well-known and commonly used methods can be employed. For example, a method of drying under normal pressure or reduced pressure at a temperature at which the toner particles do not fuse or agglomerate, a method of freeze-drying, And the like. Further, a method of simultaneously separating and drying the toner particles from the aqueous medium by using a spray drier or the like may also be used. In particular, a method of agitating and drying the powder under reduced pressure while heating at a temperature at which the toner particles do not thermally fuse or agglomerate, or a flash jet drier that instantaneously dries using a heated drying air flow (Seishin Enterprise) Is more efficient and preferable. In the drying process,
Basically, only moisture between particles is removed, and there is no residual monomer or residual solvent such as a polymerized toner in the particles, so that extremely safe toner particles can be easily obtained. In addition, since the unreacted acidic components present in the polyester resin usually flow out (wash) into the aqueous medium, the content of the unreacted components in the toner is reduced, and the toner is safer than the pulverized toner. It is advantageous in terms of sex.

With respect to the particle size distribution of the toner obtained by the production method of the present invention, 50% volume particle diameter / 50% number particle diameter was 1.50 as measured by a Coulter Multisizer TAII type.
25 or less, more preferably 1.20.
It is as follows. When the ratio is 1.25 or less, a good image can be easily obtained, which is preferable. The GSD is preferably 1.30 or less, more preferably 1.25 or less. GSD is a Coulter Multisizer TAII
As measured by a mold, (16% volume particle size / 84% volume particle size)
Is the value determined by the square root of. The smaller the GSD value, the sharper the particle size distribution, and a better image is obtained.

The toner obtained by the production method of the present invention includes
The volume average particle diameter is preferably in the range of 1 to 13 μm from the viewpoint of the obtained image quality and the like, and is preferably 3 to 10 μm.
A thickness of about μm is more preferable because it is easy to obtain matching with a current machine. For color toner,
The volume average particle size is preferably about 3 to 8 μm. When the volume average particle diameter is small, not only the resolution and the gradation are improved, but also the effect that the thickness of the toner layer for forming the printed image is reduced and the toner consumption per page is reduced is preferable.

The dried toner particles can be used as a developer as they are, but a known external additive such as inorganic oxide fine particles or organic polymer fine particles is added to the surface of the toner particles. Is preferred. Hydrophobic silica, inorganic fine particles such as titanium oxide, or organic fine particles are externally added to toner particles to improve physical properties such as fluidity and chargeability when used as a dry developer by an electrostatic printing method. effective. As the type of the external additive, hydrophobic silica or the like treated with various silicone oils is suitably used. Examples include hydrophobic silica treated with dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil, olefin-modified silicone oil, and the like.
The external addition method is processed using a known and commonly used model.

By mixing a carrier with the above toner particles, an electrostatic image developer can be obtained. The developer for developing an electrostatic image of the present invention comprises the toner of the present invention and a magnetic carrier, preferably a magnetic carrier whose surface is coated with a resin.

As the core agent (magnetic carrier) of the carrier used in the present invention, iron powder, magnetite, ferrite and the like used in a usual two-component developing system can be used. Among them, the true specific gravity is low, the resistance is high, and Ferrite or magnetite, which has excellent stability and is easy to form into a sphere and has good fluidity, are preferably used. The shape of the core agent can be used without any particular problem, such as spherical or amorphous. The average particle size is generally from 10 to 200 μm, but is preferably from 30 to 110 μm for printing a high-resolution image.

Examples of the coating resin for covering these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether polyvinyl ketone, and vinyl chloride. / Vinyl acetate copolymer, styrene / acrylic copolymer, straight silicone resin comprising organosiloxane bond or its modified product, fluororesin, (meth) acrylic resin, polyester, polyurethane, polycarbonate, phenolic resin, amino resin, melamine resin , Benzoguanamine resin, urea resin, amide resin, epoxy resin and the like can be used.

Among these, silicone resin and (meth) acrylic resin are particularly excellent in charge stability and coating strength, and can be more preferably used. Further, the charging characteristics of the developer composed of the toner particles and the carrier can be adjusted by adjusting the coating amount of a coating agent such as silicon, adding a charge control agent, and adding a conductive substance represented by carbon. In other words, the resin-coated carrier used in the present invention is a resin-coated magnetic carrier coated with at least one resin selected from silicon resin and (meth) acrylic resin using ferrite or magnetite as a core agent. It is preferable to add a charge control agent, carbon or the like during coating to adjust charging characteristics.

The method for coating the surface of the carrier core material with the resin is not particularly limited, but may be any of the following methods: an immersion method in which the carrier resin is immersed in a solution of the coating resin; Fluidized bed method in which the carrier is sprayed while being floated by flowing air, a kneader coater method in which a carrier core material and a coating resin solution are mixed in a kneader coater, and a solvent is removed.

The solvent used in the coating resin solution is not particularly limited as long as it dissolves the coating resin. For example, toluene, xylene, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane and the like can be used. The thickness of the coating layer on the carrier surface is usually 0.1
〜3.0 μm.

The carrier suitably used in the present invention, which is coated with a resin, is subjected to a heat treatment as required. In particular, when coated with a resin containing a cross-linking component, the film is reinforced by a heat cross-linking reaction, so that a more durable carrier is preferable.

When the heat treatment is performed, the charge amount when mixed with the toner can be controlled by the temperature condition. Generally, the higher the heating temperature, the higher the charge amount tends to be. Usually, the heat treatment is performed at a temperature of 100 ° C to 300 ° C for 10 minutes to 5 hours.

After the heat treatment, the carriers may adhere to each other, so that stress may be applied to loosen the carrier particles.

The weight ratio of the hydrophobic silica treated with silicone oil to the resin-coated magnetic carrier is not particularly limited, but is usually 1 to 5 parts by weight of toner particles per 100 parts by weight of the carrier. When the amount is less than 1 part by weight, triboelectric charging becomes advantageous, so that the charge amount increases and the number of differently charged particles decreases, but the transfer amount decreases,
Not preferred. On the other hand, when the content is more than 5% by weight, triboelectric charging becomes insufficient, tending to lower the rise of charging and increasing the number of differently charged particles, which is not preferable.

The toner of the present invention can be used in a normal non-magnetic one-component developing system printing device, a two-component developing system printing device, a magnetic one-component developing system printing device, and the like. Further, a non-magnetic one-component developing device or the like having a developer carrying roll and a layer regulating member is used to transfer a frictionally charged powder toner onto a flexible printed circuit board having an electrode having a function of adjusting the amount of toner passing therethrough. It can also be suitably used in a so-called toner-jet type printer or the like, in which an image is formed by directly spraying the paper on the back electrode through the hole. The toner of the present invention forms an electrostatic charge image on a latent image holding member, and develops the obtained electrostatic charge image using a developer carried on a developer carrying member. Transfer the toner image formed on the transfer material such as paper or film,
Printing can be performed by an image forming method in which the toner image on the transfer material is thermally fixed by a heat roll.

It is preferable that the heat roll used here does not use an anti-offset liquid. Further, the release layer of the heat roll preferably contains a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer. If an anti-offset liquid is used, in addition to the problem of maintenance, since silicone oil or the like is transferred to the printing paper or OHP sheet, there is a problem in that writing after printing is hindered and oil stickiness occurs. ,
Preferably, no anti-offset liquid is used. Also,
When the release layer of the heat roll contains the tetrafluoroethylene perfluoroalkyl vinyl ether copolymer, the deterioration of the fixing roll due to fatigue can be prevented, and the life of the fixing device itself can be prolonged. In addition, since the releasability is high, an offset does not occur even without the use of an anti-offset liquid, and good fixing can be achieved.

[0092]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In addition,
In Examples and Comparative Examples, parts are parts by weight and water is deionized water unless otherwise specified.

(Synthesis Example of Polyester Resin) Trimellitic anhydride (TMA) as a polycarboxylic acid and terephthalic acid (TPA) and isophthalic acid (IP as dicarboxylic acids)
A), polyoxypropylene (2.4) -2,2-bis (4-hydroxyphenyl) as an aromatic diol
Propane (BPA-PO), polyoxyethylene (2.
4) Using 2,2-bis (4-hydroxyphenyl) propane (BPA-EO) and ethylene glycol (EG) as an aliphatic diol at each molar composition shown in Table 1,
As a polymerization catalyst, tetrabutyl titanate was charged into a separable fresco at 0.3% by weight based on the total amount of monomers, and a thermometer, a stir bar, a condenser, and a nitrogen inlet tube were attached to the upper part of the flask, and a normal pressure nitrogen gas was heated in an electric heating mantle heater. After reacting at 220 ° C. for 15 hours under an air flow, the pressure was sequentially reduced, and the reaction was continued at 10 mmHg. The reaction is ASTM
-Pursuit was performed by the softening point according to E28-517, and when the softening point reached a predetermined temperature, the vacuum was stopped to terminate the reaction. Table 1 shows the composition and physical properties (characteristics) of the synthesized resin.
Shown in

[0094]

[Table 1] >600,000; area ratio of components having a molecular weight of 600,000 or more <10,000; area ratio of components having a molecular weight of 10,000 or less TMA; trimellitic anhydride TPA; terephthalic acid IPA; isophthalic acid BPA-PO; polyoxypropylene (2. 4) -2,
2-bis (4-hydroxyphenyl) propane BPA-EO; polyoxyethylene (2.4) -2,2
-Bis (4-hydroxyphenyl) propane EG; ethylene glycol BA: benzoic acid TMP; trimethylolpropane FT value; flow tester value

In Table 1, "T1 / 2 temperature" refers to a flow tester (CFT-50) manufactured by Shimadzu Corporation as described above.
0), a value measured at a heating rate of 6 ° C. per minute at a load of 10 kg per unit area (cm ² ), with a nozzle diameter of 1.0 mmΦ × 1.0 mm. The glass transition temperature “Tg” (° C.) was measured by a second run method using a differential scanning calorimeter (DSC-50) manufactured by Shimadzu Corporation.
It is a value measured at a heating rate of 0 ° C.

(Preparation of Melt-Kneaded Material) After premixing the resin, the colorant and the release agent, the mixture was kneaded with a twin-screw kneading extruder to prepare a melt-kneaded material. Regarding the color pigment, a master batch that had been made into a resin (R1) / pigment = 1/1 weight ratio with two rolls in advance was crushed and used. Table 2 shows the composition of the produced melt-kneaded product.

[0097]

[Table 2]

The releasing agents and coloring agents shown in Table 2 are as follows. Carnauba: "Carnauba wax 1" (imported by Yoko Kato) Carbon: "ELFTEX-8" (manufactured by Cabot) Pigment used for cyan master: First Gen Blue TGR (manufactured by Dainippon Ink and Chemicals) Used for yellow master Pigment: Shimla First Yellow 8GR (Dai Nippon Ink & Chemicals, Inc.) Pigment used for magenta master: First Gen Super Magenta R (Dai Nippon Ink & Chemicals, Inc.)

[0099]

[Table 3] >600,000; area ratio of components having a molecular weight of 600,000 or more <10,000; area ratio of components having a molecular weight of 10,000 or less

The properties of the blend resins used in Table 2 are shown in Table 3. As for the resin blend, resin particles having passed through 200 mesh were blended at the above-mentioned weight ratio, and each physical property value was measured.

Example 1 A melt-kneaded product MB1 was heated to 190 ° C. and fed into a Cavitron CD1010 (Eurotech Co., Ltd.) at a rate of 60 g / min. The aqueous medium is 0.
5% by weight of dilute aqueous ammonia was fed into the Cavitron at a rate of 1 L / min while heating to 160 ° C. with a heat exchanger. The rotor was operated at a speed of 9000 rpm and a pressure of 7 kg / cm ² , and the obtained slurry was cooled to 60 ° C. and taken out. Further, the solid content is reduced to 2 by diluting with deionized water.
It was adjusted to 0%.

2 parts were added to 400 parts of the obtained resin fine particle dispersion.
60 parts of 0% saline was added, the temperature was raised to 65 ° C., and the mixture was stirred for 30 minutes to cause aggregation. Thereafter, fusion was performed by stirring at 85 ° C. for 3 hours. The obtained slurry was subjected to solid-liquid separation and washing by a centrifugal separator, and then dried by a vacuum dryer to obtain toner particles. By the same operation, toner particles were prepared using MB2 to MB6. Table 4 shows the properties of the obtained toner particles.

(Example 2) The melt-kneaded material MB1 was heated to 190 ° C and fed to the Cavitron CD1010 at a rate of 60 g / min. As the aqueous medium, 0.5% by weight of dilute aqueous ammonia was fed to the cabin at a rate of 1 L / min while heating to 160 ° C. with a heat exchanger. Rotor speed is 9000
The slurry was operated at a rpm of 7 kg / cm ² and the obtained slurry was cooled to 60 ° C. and taken out. Further, the solid content was adjusted to 20% by dilution with deionized water.

2 parts were added to 400 parts of the obtained resin fine particle dispersion.
60 parts of 0% saline was added, the temperature was raised to 65 ° C., and the mixture was stirred for 30 minutes to cause aggregation. Thereafter, fusion was performed by stirring at 85 ° C. for 6 hours. The obtained slurry was subjected to solid-liquid separation and washing with a centrifuge, and then dried with a vacuum drier to obtain toner particles. By the same operation, toner particles were prepared using MB2 to MB6. In all the toner particles, particles having a volume average particle diameter of 3 μm or less were 3% (number) or less, and classification was not required. Table 4 shows the properties of the obtained toner particles.

[0105]

[Table 4] * The particle size before fusion is a value measured using a 15 μm aperture tube of Multisizer TAII type manufactured by Coulter, USA. * The particle size after fusion is a value measured using a 100 μm aperture tube of Multisizer TAII type manufactured by Coulter, USA.

Each of the obtained toner particles was embedded in a resin, cut with a microtome, and a section stained with ruthenate tetroxide was observed with a TEM (transmission electron microscope). And a state of being substantially uniformly dispersed in the particles was observed. Thereafter, using a Henschel mixer, 0.5 part of hydrophobic silica and 0.5 part of titanium oxide were externally added to 100 parts of the obtained toner particles to obtain a powder toner (toner for developing an electrostatic image). .

<Evaluation of Toner> Regarding the fixing temperature range,
The fixing temperature was determined by the following fixability test, and was indicated by the range between the upper limit and the lower limit.

(Fixing property test) Using the powder toners of Examples and Comparative Examples, a printing paper was produced at a speed of 90 mm / sec.
Ricoh Imagio DA-250 is fixed by passing it through a heat roll (the surface of the upper heat roll is coated with a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer), and the fixed image is coated with Cellotape (registered trademark). The surface temperature of the heat roll when the ID (image density) after pasting and peeling is 90% or more of the original ID and no occurrence of offset is observed is referred to as “fixing temperature”.
And From the results shown in Table 5, it was confirmed that the examples of the present invention exhibited good fixing start temperature and hot offset resistance under oil-less fixing conditions in which oil was not applied.

(Image Output Test) Further, with respect to the powder toner of each example, image output was performed using a commercially available non-magnetic two-component developing type copying machine and non-magnetic one-component printer, and fog and resolution were measured. The properties and the gradation were evaluated, and good images were obtained in each case.

Regarding the OHP permeability, the following OH
It was evaluated by the evaluation method of P definition. (Method of Evaluating OHP Clearness (Color Transparency)) An unfixed image was formed on a OHP sheet using a color toner, and the unfixed image was fixed using a separately prepared fixing tester.
The fixing was performed by passing through a heat roll (oil-less type: coated with a tetrafluoroethylene perfluoroalkylvinyl ether copolymer) of Ricoh Imagio DA-250 at a heat roll temperature of 160 ° C. and a speed of 90 mm / sec. The OHP sheet printed in black was placed on the OHP sheet created in the above procedure, projected on a screen by an overhead projector, and the sharpness of characters was visually evaluated. The evaluation results are shown as “○” when the characters are clearly visible, “△” when the characters are blurred, and “×” when the characters are not distinguishable. The sample using the crosslinked resin is slightly inferior in sharpness, but the other samples have good OH
It showed P permeability.

(Evaluation of Heat Resistance Storage Stability) Further, when the heat resistance blocking test of the toners of the examples was conducted at 50 ° C. for 3 days, no aggregation was observed in any of the toners.

(Measurement of Charge Amount) The charge amount was measured by preparing a developer by mixing 3/97 of an externally added toner and a ferrite carrier (particle size: 90 μm) coated with a silicone resin.
After stirring by a ball mill for 30 minutes, measurement was performed by a blow-off method. All the samples show almost the same charge amount, and it can be seen that the difference between the colors is small.

[0113]

[Table 5]

(Comparative Example 1) 89 parts of R1 as a resin, 6 parts of carbon as a coloring agent, and 5 parts of carnauba wax as a release agent were premixed, and then kneaded with a biaxial kneading extruder to prepare a melt-kneaded product. . The obtained melt-kneaded material was
The mixture was heated to 0 ° C. and fed to Cavitron CD1010 (Eurotech Co., Ltd.) at a rate of 100 g / min. 0.5% by weight of dilute aqueous ammonia is used as an aqueous medium in a heat exchanger.
While heating to 60 ° C., the mixture was fed into the Cavitron at a rate of 1 L per minute. Rotor speed is 8000 rpm, pressure is 7
Operating at Kg / cm ² , the resulting slurry was cooled to 60 ° C. and removed. Further, the solid content was adjusted to 20% by dilution with deionized water. Thereafter, solid-liquid separation was performed by a centrifugal separator, washed and washed with water, and dried by a vacuum dryer to obtain toner particles. The resulting toner particles have a Dv50 of 6.
7 μm, Dv50 / Dn50 1.38, GSD 1.40, average circularity 0.
980, 11% of particles having a volume average particle diameter of 3 μm or less
(Number). Without classifying 100 parts of the toner, 0.5 parts of hydrophobic silica and 0.5 parts of titanium oxide were externally added using a Henschel mixer to obtain a powder toner (toner for developing an electrostatic image). When an image output test was performed using this toner in the same manner as the toner of the example, fog, resolution,
The printed matter was inferior in any gradation.

[0115]

As described above, according to the method for producing a toner for developing an electrostatic image of the present invention, in a spherical or irregular toner having a polyester resin as a binder resin, a solvent-free and fine powder having a small particle size distribution can be obtained. Good toner can be manufactured efficiently. Also, no residual solvent is contained in the toner, and COD
Will also be lower. Further, the obtained toner has good fixability by an oilless fixing heat roll.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining how to determine a flow tester value, where (a) is a side sectional view showing an outline of a measuring device,
(B) is a graph for explaining a method of obtaining each flow tester value from a measured value.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinji Amagaya 1-4-604 Minamiurawa, Saitama-shi, Saitama F-term (reference) 2H005 AA01 AA06 AB03 CA08 CA14 EA03 EA05 EA06 EA10 2H033 AA09 BA25 BA58 BB01 BB04

Claims (14)

[Claims] 1. A toner raw material containing at least a polyester resin is heated and melted to produce a melt of the toner raw material, and then the melt is emulsified in an aqueous medium to form resin fine particles. Thereafter, the resin fine particles are agglomerated and further fused to produce an aggregate of the resin fine particles, thereby producing a toner for developing an electrostatic image. 2. The electrostatic charge according to claim 1, wherein the polyester resin is a polyester resin containing an acidic group, and the polyester resin is emulsified in an aqueous medium in the presence of a basic neutralizing agent. A method for producing an image developing toner. 3. The method according to claim 1, wherein the acidic group is a carboxyl group, and the acid value of the polyester resin containing the carboxyl group is 1 to 3.
3. The method according to claim 2, wherein the amount is in the range of 20 KOH mg / g. 4. The polyester resin has a T1 / 2 temperature of 120 to 18 measured by a constant load extrusion type capillary rheometer.
0 ° C., glass transition temperature (Tg) of 40 to 75 ° C., ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw /
2. The method of claim 1, wherein Mn) is 12 or more. 5. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the polyester resin contains a plurality of polyester resins having different T1 / 2 temperatures. 6. The polyester resin having a (A) T1 / 2 temperature of 80 measured by a constant load extrusion type capillary rheometer.
° C or higher and lower than 120 ° C, and the glass transition temperature is 40 to
A linear or branched polyester resin having a temperature range of 70 ° C., (B) a T1 / 2 temperature of 120 ° C. or more and 210 ° C. or less with a constant load extrusion type capillary rheometer, and a glass transition temperature of 50 to 50 ° C. It contains a crosslinked or branched polyester resin in the range of 75 ° C., and the weight ratio of the resin (A) to the resin (B) is (A) / (B) = 2.
0/80 to 80/20, and assuming that the T1 / 2 temperature is T1 / 2 (A) and T1 / 2 (B), respectively, 20 ° C. <T1 / 2 (B) −T1 / 2 (A) < The method for producing a toner for developing an electrostatic image according to claim 1, wherein the relationship is 100 ° C. 7. The method for producing a toner for developing electrostatic images according to claim 1, wherein the 50% volume average particle diameter of the resin fine particles is 0.1 μm to 6 μm. 8. When emulsifying the resin fine particles, the ring-shaped stator having the slit and the ring-shaped rotor having the slit are kept at a small interval, and the stator and the rotor mesh with each other. 2. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein a high-speed rotation type continuous emulsifying and dispersing machine arranged coaxially is used. 9. The method according to claim 1, wherein the melt is a melt obtained by heating and melting a toner raw material containing at least a polyester resin and a colorant. Method. 10. The method for producing a toner for developing an electrostatic image according to claim 9, wherein the raw material for toner further contains a release agent. 11. The method for producing a toner for developing an electrostatic image according to claim 10, wherein the release agent contains a synthetic ester wax and / or a natural ester wax. 12. An electrostatic image is formed on an electrostatic image holding member, and the electrostatic image is developed using a developer composed of an electrostatic image developing toner carried on a developer carrying member. The toner image formed on the electrostatic image holder is transferred onto a transfer material, and the toner image on the transfer material is heat-fixed by a heat roll to form a heat-fixed toner image on the transfer material. An image forming method, comprising using the electrostatic image developing toner manufactured by the manufacturing method according to claim 1. 13. The image forming method according to claim 12, wherein no offset preventing liquid is used for said heat roll. 14. The image forming method according to claim 12, wherein the release layer of the heat roll contains a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer.