JP2002278139A - Electrostatic charge image developer and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developer capable of stably forming images having no image stain and high image quality over a long period of time and to provide an image forming method using the developer. SOLUTION: The electrostatic charge image developer comprises a toner obtained by subjecting resin particles containing a specified crystalline ester compound as a release agent in a bonding resin and colorant particles to salting- out/fusion and a carrier obtained by dispersing magnetic powdery particles in a resin. The image forming method includes a step in which a recording material with a toner image formed by development with the electrostatic charge image developer is passed between a heating roller and a pressing roller to fix the toner image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developer used for, for example, a copying machine, a printer, and the like, and an image forming method using the same.

[0002]

2. Description of the Related Art At present, a two-component developer composed of a carrier and a toner is widely used as an electrostatic image developer used in, for example, electrophotography. Examples of the carrier constituting such a two-component developer include a carrier made of a magnetic material such as iron, magnetite, and ferrite, and a resin-coated carrier in which a resin coating layer is formed on core particles made of these magnetic materials. Have been.

On the other hand, as toner, there is a demand for a reduction in particle size in order to improve the quality of a toner image. Conventionally, pulverized toner produced by a pulverization method has been widely used. In comparison, the energy required to reduce the particle size of the toner is small, and there is no problem such as generation of fine powder due to pulverization. Therefore, a so-called polymerized toner manufactured by a polymerization method is considered to be useful. ing. Here, as the polymerization method toner, for example, a suspension polymerization toner and an associative toner are known, and the associative toner is preferable because its shape can be easily controlled.

However, the associative particles (colored particles) obtained by associating the resin particles with the colorant particles are irregular and have a smooth surface. There is a problem that the chargeability of the toner becomes non-uniform and, as a result, a stable image cannot be formed over a long period of time.

On the other hand, as a method of fixing a toner image formed on a recording material such as transfer paper, a method of fixing a toner image by forming a recording material on which the toner image is formed is passed between a heating roller and a pressure roller. Roll fixing systems are widely used.

However, the heat roll fixing method has a drawback that an image is easily stained due to an offset phenomenon in which a toner in a molten state adheres to a heating roller. For this reason, it has been widely practiced to add a release agent to the toner to impart releasability to the toner itself and improve fixability. When the release agent is added, it is necessary to add the release agent in a large amount or in a finely dispersed state since the release agent is hardly unevenly distributed on the surface of the toner particles. As a method of adding a release agent to a toner obtained by a polymerization method, a method of associating resin particles with release agent particles is known.

However, according to this method, the release agent is released from the associated particles of the resin particles and the release agent particles, and the release agent is fused to a triboelectric charging member such as a carrier to lower the chargeability. In addition, a sufficient amount of release agent cannot be introduced into the obtained associated particles, and the content of the release agent varies between the associated particles to be formed. There is a problem that the releasability cannot be exhibited. In particular, crystalline ester compounds,
When a so-called ester wax is used as a release agent, such a problem is conspicuous because the ester wax itself has a low molecular structure and less entanglement of molecular chains as compared with a so-called polyolefin wax. Appears in

[0008] Further, the image forming method using the toner has problems such as a demand for high image quality of the initial image and prevention of deterioration of image quality and occurrence of image defects due to repeated use. For example, a decrease in gradation, a decrease in fine line reproducibility,
It is necessary to solve problems such as image density change, density unevenness, fog, and the like. The major causes of these problems include difficulty in controlling the toner charge amount and instability. Since the toner charge uses frictional charging, it is extremely difficult to control and stabilize the toner charge. To address these problems, numerous proposals have been made with a binder resin for a toner, a charge control agent, an external additive, other additives, and the like, and the list is complete. However, with the improvement of the performance and reliability of each image forming process using toner, higher image quality and higher durability of the developer have been pursued.

In recent years, the electrophotographic system has been used in various fields. For example, it is used not only in monochrome copying machines but also in fields such as printers that are output terminals of computers, color copying machines, color printers, and the like. As their use advances, the demands on image quality are increasing. In particular, in a multicolor image forming method in which an image is formed by superposing a plurality of toner images using color toners, a slight change in developability (amount of developed toner) due to a minute change in chargeability or the like, and a change in transferability of halftone, The change in the hue of the secondary color due to the superposition is large, and therefore, the requirements for stability such as chargeability are extremely severe.

Conventionally, a resin-dispersed carrier in which magnetic particles are dispersed and contained in binder resin particles as a carrier is known, but this carrier is liable to adhere to a component of toner particles. Therefore, spent toner tends to be generated, and this tendency is clear when the particle size of the toner is small. In particular, when the toner is produced by being melt-kneaded with a binder resin and other components such as a colorant and a release agent, and then pulverized, toner fine powder is inevitably contained, which is a carrier. Due to the high adhesion of the particles to the surface, the above tendency is remarkable, and as a result, a developer having excellent durability cannot be obtained.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to
An object of the present invention is to provide an electrostatic image developer capable of stably forming a high-quality image free of image stains over a long period of time. Another object of the present invention is to provide an image forming method capable of stably forming a high-quality image free from image contamination for a long period of time.

[0012]

According to the present invention, there is provided an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier.
The toner is obtained by salting out / fusing resin particles containing a release agent into a binder resin and colorant particles,
The release agent comprises a crystalline ester compound represented by the following general formula (1), and the carrier is characterized in that at least magnetic powder particles are dispersed in a resin.

[0013]

Embedded image

The electrostatic image developer of the present invention is an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier. Wherein the release agent comprises a crystalline ester compound represented by the above general formula (1). And a toner particle having a shape coefficient of variation coefficient of 16% or less and a number variation coefficient of 27% or less in a number particle size distribution.
It is characterized in that at least magnetic powder particles are dispersed in a resin.

The electrostatic image developer of the present invention is an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier. Wherein the release agent comprises a crystalline ester compound represented by the above general formula (1). And the ratio of toner particles having no corners is 50
It is composed of toner particles having a number variation of at least 27% and a number variation coefficient of 27% or less in a number particle size distribution, and the carrier is characterized in that at least magnetic powder particles are dispersed in a resin. .

The electrostatic image developer of the present invention is an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier. Wherein the release agent comprises a crystalline ester compound represented by the above general formula (1). In addition, the ratio of the toner particles having a shape coefficient in the range of 1.2 to 1.6 is 65% by number or more, and the coefficient of variation of the shape coefficient is 16% or less. , Characterized in that at least the magnetic powder particles are dispersed in a resin.

According to the image forming method of the present invention, a recording material on which a toner image developed by an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier is heated. In an image forming method including a step of fixing by passing between a roller and a pressure roller, the toner is obtained by salting out / fusing resin particles containing a release agent and colorant particles in a binder resin. Wherein the release agent comprises a crystalline ester compound represented by the following general formula (1), and the carrier comprises at least magnetic powder particles dispersed in a resin. There is a feature.

[0018]

Embedded image

According to the image forming method of the present invention, a recording material having a toner image developed by an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier is heated. In an image forming method including a step of fixing by passing between a roller and a pressure roller, the toner is obtained by salting out / fusing resin particles containing a release agent and colorant particles in a binder resin. Wherein the release agent comprises the crystalline ester compound represented by the general formula (1), and the coefficient of variation of the shape factor is 16% or less; The carrier is composed of toner particles having a number variation coefficient of 27% or less in distribution, and the carrier is characterized in that at least magnetic powder particles are dispersed in a resin.

According to the image forming method of the present invention, a recording material on which a toner image developed by an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier is heated. In an image forming method including a step of fixing by passing between a roller and a pressure roller, the toner is obtained by salting out / fusing resin particles containing a release agent and colorant particles in a binder resin. Wherein the release agent comprises the crystalline ester compound represented by the general formula (1), and the ratio of the toner particles having no corners is 50% by number or more. The carrier is composed of toner particles having a number variation coefficient of 27% or less in the number particle size distribution, and the carrier is characterized in that at least magnetic powder particles are dispersed in a resin.

According to the image forming method of the present invention, a recording material on which a toner image developed by an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier is formed. In an image forming method including a step of fixing by passing between a heating roller and a pressure roller, the toner salt-outs / fuses resin particles containing a release agent and colorant particles in a binder resin. Wherein the release agent comprises the crystalline ester compound represented by the general formula (1), and the shape factor falls within a range of 1.2 to 1.6. The percentage of certain toner particles is 65
It is composed of toner particles having a number% or more and a variation coefficient of a shape coefficient of 16% or less, and the carrier is characterized in that at least magnetic powder particles are dispersed in a resin.

[0022]

According to the developer of the present invention, an association type toner obtained by salting out / fusing resin particles containing a release agent and colorant particles, and a specific carrier are provided. In addition, migration and release of the release agent to the carrier are suppressed, and stable chargeability is obtained. As a result, a high-quality image free from image contamination is formed.

According to the present invention, a specific associative toner obtained by salting out / fusing resin particles containing a release agent into a binder resin together with colorant particles in an aqueous medium is used. The above object can be achieved by combining at least a carrier in which magnetic powder particles are dispersed in a resin.

That is, according to this specific associative toner, since the release agent is present in the toner particles (associative particles) in a fine domain structure, the adhesion of the release agent (ester-based wax) itself is reduced. , The adhesion of the release agent to the carrier can be suppressed, and the chargeability can be further stabilized. In addition, since the dispersion of the release agent (dispersion area / dispersion amount) and the surface state among the toner particles can be reduced, sufficient releasability is ensured, and a high-quality image free from image contamination can be obtained. Obtainable.

Further, by using toner composed of toner particles having a shape coefficient variation coefficient of 16% or less and a number variation coefficient in the number particle size distribution of 27% or less, the chargeability of the toner is stabilized. And a high-quality image can be formed over a long period of time.

Further, the ratio of toner particles having no corners is set to 50% by number or more, and the number variation coefficient in the number particle size distribution is 2%.
By using a toner composed of toner particles controlled to 7% or less, the chargeability of the toner can be stabilized, and a high-quality image can be formed for a long period of time.

Further, by using a toner in which the proportion of toner particles having a shape coefficient in the range of 1.2 to 1.6 is 65% by number or more and the variation coefficient of the shape coefficient is 16% or less, The chargeability of the toner can be stabilized, and a high-quality image can be formed for a long period of time.

In a multicolor image forming method of forming an image by superposing a plurality of toner images using color toners, stable charging properties can be obtained between toner particles of each color, so that transfer characteristics are stable and secondary The change in color hue is reduced, and a high-quality color image can be formed.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The developer of the present invention is a two-component developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier. The carrier is formed by dispersing at least magnetic powder particles in a resin.

The resin-dispersed carrier can be prepared by melt-kneading an appropriate resin and magnetic powder and pulverizing the mixture. This carrier itself has a low specific gravity due to its high resin content compared to a normal ferrite carrier, and therefore can reduce the stress acting on the toner due to agitation of the developing device. In this case, a developer having excellent durability can be obtained. Further, the resin-dispersed carrier prepared by the pulverization method has a problem that since the magnetic powder is exposed on the surface thereof, the toner component adheres to that portion to cause spent. Particularly, in the case of the toner prepared by the pulverization method, the protrusions and fine particles formed by the pulverization are apt to adhere to the part, which eventually contaminates the carrier, and from this point, there is a problem that the durability is reduced. .

However, in the present invention, since the salting-out / fusing-type toner is used as the toner, the toner has excellent durability as a developer because it has a uniform shape, no large projections, and no fine particles. And a long service life. Furthermore, if the toner has a high uniformity in shape and particle size, the chargeability is also stable.

In general, a resin-dispersed carrier has a non-uniform surface itself, but the charge amount distribution can be narrowed by making the toner-side charge characteristics highly uniform. Also, when an ester wax is used as a release agent, the release agent itself is a compound having a low molecular structure, so unlike a so-called polyolefin wax, there is little entanglement of molecular chains, and the wax itself transfers to a carrier. However, the use of a resin-dispersed carrier can reduce the stress and suppress the transfer of the release agent.

The resin constituting the carrier particles is not particularly limited, and examples thereof include a styrene acrylic resin, a polyester resin, and a phenol resin.

The resin-dispersed carrier can be prepared, for example, by a method in which a resin and a magnetic powder are melt-kneaded and pulverized, as described in, for example, JP-A-8-6303 and JP-A-11-24622. The so-called polymerization method shown can also be used. For example, when obtaining a carrier obtained by dispersing a magnetic powder in a phenolic resin, the magnetic powder, a phenol and an aldehyde are mixed in an aqueous medium in the presence of a basic catalyst while stirring and mixing the powder in an aqueous medium.
By raising the temperature to 90 ° C., phenol aldehyde resin particles are formed, and a spherical carrier in which the magnetic powder is dispersed in the resin particles is obtained. Further, a carrier having a laminated structure can be formed by adding a non-magnetic component at an intermediate stage in this manufacturing method, that is, at a time of a gel state.

The content ratio of the magnetic powder in the resin-dispersed carrier is generally 50 to 90% by mass, though it depends on the desired magnetic susceptibility. The saturation magnetization of this magnetic material is determined when the measured magnetic field is 300
30 to 80 Am when 0 (1000 / 4π · A / m)
² / kg, and if it exceeds this range,
Since the magnetization is strong, the spike of the developer becomes hard, and the rubbing force in the development becomes excessive, so that the developer is easily deteriorated. In addition, when it is less than this range, the obtained magnetic force is too small, so that the carrier is scattered, so that image defects and scratches on the photoreceptor due to carrier adhesion are likely to occur.

The residual magnetization of the magnetic powder is 10 A when the measured magnetic field is 3000 (1000 / 4π · A / m).
It is preferably at most m ² / kg. If the remanent magnetization is high, the carrier becomes poor due to paramagnetization, which causes uneven development and the like.

In the present invention, the carrier has a volume average particle size of 20 to 80 μm, preferably 20 to 60 μm.
m, more preferably 25 to 55 μm. In addition, the ratio (Dv / Dn) of the number average particle diameter (Dn) to the volume average particle diameter (Dv) is preferably 1.5 or less, more preferably 1.3 or less. As described above, according to the carrier having a sharp particle size distribution, the uniformity of the chargeability is improved, and a stable image can be formed over a long period of time.

The particle size of the carrier can be measured by using a laser diffraction type particle size distribution analyzer. Specific examples of such a measuring device include HELOS (manufactured by Sympathic). it can.

The magnetic powder used for the construction of the carrier is not particularly limited, and those conventionally used for this type of application can be used as they are. The magnetic material is a ferromagnetic element or an alloy or compound containing them, and examples thereof include compounds such as magnetite, maghemite, and ferrite; metals such as iron, cobalt, nickel, and manganese; and alloys thereof.

The shape of the magnetic powder itself may be spherical, octahedral, cubic, or the like. In the present invention, spherical magnetic powder can be suitably used. Dispersibility is obtained. Here, the spherical magnetic powder refers to a powder having a ratio of a major axis to a minor axis of 0.9 or more measured using a scanning electron microscope or a transmission electron microscope. The particles of the magnetic powder preferably have a number average primary particle diameter of 0.01 to 1 μm, more preferably 0.1 to 0.5 μm. This particle size is a value measured by a transmission electron microscope. Specific examples of the magnetic powder that can be preferably used in the present invention include, for example, EPT-5.
00, EPT-1000, MAT-305 (manufactured by Toda Kogyo), BL-100, BL-500, RB-BL, BL
-SP (manufactured by Titanium Industry Co., Ltd.) and others.

The particle size of the carrier obtained as described above is preferably from 10 to 100 μm, more preferably from 25 to 80 μm, even more preferably from 35 to 70 μm in terms of volume average particle size. When the volume average particle size is smaller than 10 μm, the carrier particles tend to adhere to the photoreceptor, making it difficult to form a high quality image.
On the other hand, when the volume average particle size is larger than 100 μm, the magnetic brush formed on the developing sleeve becomes coarse, and it becomes difficult to form a high quality image. Here, the volume average particle diameter of the carrier was determined by taking a photograph of the carrier particles enlarged 250 times with a scanning electron microscope, measuring the maximum major axis diameter of the carrier particles based on the photograph, and measuring this measurement by 500 times. For each carrier particle,
It is obtained by calculating their average value.

The particle size distribution of the carrier particles is such that the carrier particles having a particle size of less than 25 μm are 15% by mass or less,
m is 1 to 35% by mass, and carrier particles of 37 μm or more and less than 44 μm are 3 to 70% by mass, 44 μm.
m to less than 63 μm, 2 to 70% by mass of carrier particles;
45% by mass of carrier particles of 63 μm or more and less than 75 μm
Hereinafter, it is preferable that the carrier particles having a size of 75 μm or more be 20% by mass or less. When the particle size distribution satisfies the above range, variations in chargeability and magnetic properties among carrier particles can be reduced, and a high-quality image can be stably formed for a long period of time. This particle size distribution has an opening of 25 μm, 37 μm, 44 μm,
Using standard sieves of 63 μm and 75 μm, the sieves are stacked in the order of the opening size, and 100.0 g of the carrier is placed at the top. Then, the number of horizontal turns = 285 times /
The number of vibrations is 150 minutes / minute. The sieve is obtained by measuring the remaining amount of each sieve and the mass flowing out from the lowermost layer.

The resistance of the carrier is preferably 10 ⁶ Ωcm or more, more preferably 10 ⁸ Ωcm to 1 Ωcm.
0 ¹³ Ωcm. When the resistance of the carrier is less than 10 ⁶ Ωcm, carrier adhesion due to injection of electric charge from the photoreceptor surface to carrier particles is likely to occur,
It is difficult to form a high quality image. here,
The method for measuring the resistance of the carrier is as follows. That is, the cross-sectional area of the measurement cell was set to 1 cm ² , 1 g of the carrier was placed in the measurement cell as a measurement sample, the height (h) was measured, and a load of 1 kg was applied to the cell filled with the measurement sample. A voltage (V) was applied between the electrode and the lower electrode, a flowing current (i) was measured, and a resistance was obtained by using the following equation. The current value is 3 after applying the voltage.
The value after 0 seconds was used. Further, the measurement environment condition is a normal temperature and normal humidity environment (20 ° C./50% RH).

[0044]

## EQU1 ## Carrier resistance [Ωcm] = V / (i × h)

The toner constituting the developer of the present invention is a toner containing a binder resin, a colorant, and a release agent, and includes resin particles containing a release agent in the binder resin, It is composed of associative toner particles obtained by salting out / fusing the particles.

The release agent constituting the toner is composed of a crystalline ester compound represented by the above general formula (I) (hereinafter referred to as a “specific ester compound”). It can be suitably synthesized by a dehydration condensation reaction.

Formula (I) representing a specific ester compound
In the above, R ¹ and R ² each represent a hydrocarbon group which may have a substituent. The number of carbon atoms in the hydrocarbon radical R ¹ is 1 to 40, preferably 1 to 20, more preferably 2 to 5. The hydrocarbon group R2 has 1 to 40 carbon atoms, preferably 16 to 30, more preferably 18 to ² carbon atoms.
6 is assumed. Further, the hydrocarbon group R ¹ and the hydrocarbon group R
² may be the same or different. In the general formula (I), n is an integer of 1 to 4,
It is preferably 2 to 4, more preferably 3 to 4, and particularly preferably 4.

Specific examples of the specific ester compound include:
Compounds represented by the following formulas (W1) to (W22) can be exemplified.

[0049]

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[0050]

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The content of the release agent is usually 1 to 30% by mass.
And preferably 2 to 20% by mass, more preferably 3 to 15% by mass.

In the present invention, the “resin particles containing a release agent” are obtained by dissolving a release agent in a monomer for obtaining a binder resin and dispersing the obtained monomer solution in an aqueous medium. By subjecting this system to a polymerization treatment, it can be obtained as latex particles.

As a preferred polymerization method for obtaining resin particles containing a release agent, the release agent is contained in a monomer in an aqueous medium in which a surfactant having a concentration equal to or lower than the critical micelle concentration is dissolved. The monomer solution obtained by dissolution is formed into oil droplets (10 to 1000 nm) using mechanical energy to prepare a dispersion, and a water-soluble polymerization initiator is added to the obtained dispersion, A method of radical polymerization (hereinafter, referred to as “mini-emulsion method” in this specification) can be exemplified. Instead of adding the water-soluble polymerization initiator, or together with the addition of the water-soluble polymerization initiator, an oil-soluble polymerization initiator may be added to the monomer solution.

Here, the disperser for dispersing oil droplets by mechanical energy is not particularly limited, and a stirrer “CLEARMIX” (M Technic) equipped with a high-speed rotating rotor (Trade name), an ultrasonic disperser, a mechanical homogenizer, a Menton-Gaulin and a pressure homogenizer. Further, the dispersed particle diameter is 10 to 1
000 nm, preferably 30 to 300 nm.

The binder resin constituting the toner has a molecular weight distribution of 150,000 to 1,000 as measured by GPC.
It is preferable that the resin contains a high molecular weight component having a peak or a shoulder in a region of 0000 and a low molecular weight component having a peak or a shoulder in a region of 1,000 to 20,000. In addition, 50,000 to 1
It is preferable to contain an intermediate molecular weight component having a peak or shoulder in the region of 40,000. As described above, by using the high molecular weight component and the low molecular weight component together, it is possible to achieve both the improvement of the offset resistance and the fixing property (adhesion to the recording material).

Here, as a method of measuring the molecular weight of the resin by GPC, tetrahydrofuran (THF) is added to 0.5 to 5.0 mg (specifically, 1 mg) of a measurement sample.
Add cc and stir at room temperature using a magnetic stirrer or the like to dissolve sufficiently. Next, after treating with a membrane filter having a pore size of 0.45 to 0.50 μm, the mixture is injected into GPC. The GPC measurement conditions were as follows: the column was stabilized at 40 ° C., and THF was set to 1 c / min.
c at a flow rate of 1 mg / cc,
Inject μl and measure. The column is preferably used in combination with a commercially available polystyrene gel column.
For example, Shodex GPC KF-
801,802,803,804,805,806,8
07 combination or TSKgelG1000 manufactured by Tosoh Corporation
H, G2000H, G3000H, G4000H, G5
000H, G6000H, G7000H, TSK gu
ard column and the like. As the detector, a refractive index detector (IR detector) or a UV detector may be used. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve created using monodispersed polystyrene standard particles.
It is preferable to use about 10 polystyrenes for preparing a calibration curve.

Hereinafter, the constituent materials of the resin particles and the preparation method (polymerization method) will be described. As the polymerizable monomer used to obtain the resin particles, a radical polymerizable monomer is an essential component, and a crosslinking agent can be used as necessary. It is preferable that at least one of the following radical polymerizable monomers having an acidic group or a radical polymerizable monomer having a basic group is contained.

(1) Radical polymerizable monomer: The radical polymerizable monomer is not particularly limited, and a conventionally known radical polymerizable monomer can be used.
Further, one kind or a combination of two or more kinds can be used so as to satisfy required characteristics. Specifically, aromatic vinyl monomers, (meth) acrylate monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers And halogenated olefin monomers.

As the aromatic vinyl monomer, for example,
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- Styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

Examples of the (meth) acrylate-based monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, and ethyl methacrylate. Butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl benzoate and the like.

Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like. Monoolefin monomers include ethylene, propylene, isobutylene, 1-butene, 1-pentene,
-Methyl-1-pentene and the like.

Examples of the diolefin-based monomer include butadiene, isoprene and chloroprene.

Examples of the halogenated olefin monomer include:
Vinyl chloride, vinylidene chloride, vinyl bromide and the like.

(2) Crosslinking agent: As a crosslinking agent, a radical polymerizable crosslinking agent may be added in order to improve the properties of the toner. Examples of the radical polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinylether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

(3) Radical polymerizable monomer having an acidic group or a basic group: Examples of the radical polymerizable monomer having an acidic group or the radical polymerizable monomer having a basic group include a carboxyl group. Amine-containing compounds, sulfonic acid group-containing monomers, amine compounds such as primary amines, secondary amines, tertiary amines, and quaternary ammonium salts can be used. As the radical polymerizable monomer having an acidic group, as a carboxylic acid group-containing monomer, acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monomer Octyl ester and the like. Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate, and the like. These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.

Examples of the radical polymerizable monomer having a basic group include amine compounds, such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary of the above four compounds. Ammonium salt, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide,
Piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide; vinylpyridine, vinylpyrrolidone; vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diallylmethylammonium chloride, N, N- Diallylethylammonium chloride and the like can be mentioned.

In the present invention, as the radical polymerizable monomer, a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group is used in an amount of 0.1 to 15% of the whole monomer. It is preferable to use at a ratio of mass%,
The radical polymerizable cross-linking agent is preferably used in the range of 0.1 to 10% by mass based on the total radical polymerizable monomer, depending on its properties.

For the purpose of adjusting the molecular weight of the resin particles, a generally used chain transfer agent can be used. The chain transfer agent is not particularly limited. For example, mercaptans such as octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, n-octyl-3-mercaptopropionate, terpinolene, carbon tetrabromide and α-methyl Styrene dimer or the like is used.

In the present invention, any suitable radical polymerization initiator can be used as long as it is water-soluble. For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4'-azobis4
-Cyanovaleric acid and its salt, 2,2'-azobis (2-
Amidinopropane) salts), peroxide compounds and the like. Further, the radical polymerization initiator can be used as a redox initiator in combination with a reducing agent, if necessary. The use of the redox initiator increases the polymerization activity, so that the polymerization temperature can be lowered and the polymerization time can be further reduced. As the polymerization temperature, any temperature may be selected as long as it is equal to or higher than the minimum radical generation temperature of the polymerization initiator.
A range of ° C is used. However, polymerization initiator started at room temperature,
For example, when a combination of hydrogen peroxide and a reducing agent (such as ascorbic acid) is used, the polymerization can be performed at room temperature or higher.

In order to carry out polymerization using the above-mentioned radical polymerizable monomer, it is necessary to disperse oil droplets in an aqueous medium using a surfactant. The surfactant that can be used here is not particularly limited, but the following ionic surfactants can be mentioned as preferred examples.

Examples of the ionic surfactant include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-
Sodium disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline,
2,2,5,5-tetramethyl-triphenylmethane-
4,4-diazo-bis-β-naphthol-6-sulfonate, etc.), sulfates (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, laurin) Sodium, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, etc.). Further, a nonionic surfactant can also be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, an ester of polyethylene glycol and higher fatty acid, an alkylphenol polyethylene oxide, an ester of higher fatty acid and polyethylene glycol, an ester of higher fatty acid and polypropylene oxide, a sorbitan ester And the like.

As a colorant constituting the toner, carbon black, a magnetic substance, a dye, a pigment and the like can be arbitrarily used. Examples of the carbon black include channel black, furnace black, acetylene black, thermal black, lamp black and the like. Is used. As the magnetic material, ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys which do not contain ferromagnetic metals but show ferromagnetism by heat treatment, For example, alloys of a type called a Heusler alloy such as manganese-copper-aluminum and manganese-copper-tin, chromium dioxide, and the like can be used.

As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 1
22, C.I. I. Solvent Yellow 19, 44, 7
7, 79, 81, 82, 93, 98, 1
03, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95, etc., and mixtures thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122,
139, 144, 149, 166, 177,
178, 222, C.I. I. Pigment Orange 3
1, 43, C.I. I. Pigment Yellow 14, 1
7, 93, 94, 138, 155, 156,
180, 185, C.I. I. Pigment Green 7,
C. I. Pigment Blue 15: 3, 60 and the like, and mixtures thereof can also be used. Although the number average primary particle diameter varies depending on the type, it is generally about 10 to 2
It is preferably about 00 nm.

As the coloring agent, a surface-modified coloring agent may be used. As the surface modifier, a conventionally known one can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used.

To the toner, a so-called external additive can be added for the purpose of improving fluidity, chargeability and cleaning property. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles, and lubricants can be used. As the inorganic fine particles, it is preferable to use inorganic oxide particles such as silica, titania, and alumina. Further, it is preferable that these inorganic fine particles have been subjected to a hydrophobic treatment with a silane coupling agent, a titanium coupling agent, or the like. . The degree of the hydrophobic treatment is not particularly limited,
Those having a methanol wettability of 40 to 95 are preferred. Here, methanol wettability is
This is to evaluate the wettability to methanol. In this method, 0.2 g of the inorganic fine particles to be measured is weighed and added to 50 ml of distilled water placed in a 250 ml beaker. Methanol is slowly dropped from a burette whose tip is immersed in the liquid until the whole of the inorganic fine particles is wet with slow stirring. The amount of methanol required to completely wet the inorganic fine particles is a (ml)
In this case, the degree of hydrophobicity is calculated by the following equation.

[0077]

## EQU2 ## Degree of hydrophobicity = [a / (a + 50)] × 100

As the organic fine particles, spherical organic particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As the organic fine particles, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used. As the lubricant, for example, salts of zinc, aluminum, copper, magnesium, calcium and the like of stearic acid, zinc, manganese, iron, copper of oleic acid,
Metal salts of higher fatty acids such as salts of magnesium and the like, salts of zinc, copper, magnesium and calcium of palmitic acid, salts of zinc and calcium of linoleic acid, and salts of zinc and calcium of ricinoleic acid.

The ratio of addition of these external additives is 0.1 to 5.0% by mass, preferably 0.5 to 4.0% in the toner.
It is the ratio that results in mass%. Various external additives may be used in combination.

Examples of the method for producing the toner of the present invention include: (1) a dissolving step of dissolving a release agent in a monomer to prepare a monomer solution; and (2) a monomer solution obtained. Is dispersed in an aqueous medium, (3) a polymerization step of preparing a dispersion (latex) of resin particles containing a release agent by polymerizing the aqueous dispersion of the resulting monomer solution, (4) a salting-out / fusion step of salting out / fusing the obtained resin particles and the colorant particles in an aqueous medium to obtain associated particles (toner particles); A filtration / washing step of filtering and removing a surfactant or the like from the associated particles by filtration from the medium, (6) a drying step of the washed associated particles, and (7) drying the associated particles. An external additive adding step of adding an external additive may be included.

(1) Dissolution step: The method for dissolving the release agent in the monomer is not particularly limited. As the amount of the release agent dissolved in the monomer, the content of the release agent in the finally obtained toner is 1 to 30% by mass, preferably 2 to 20% by mass, and more preferably 3 to 15% by mass. And the amount Incidentally, an oil-soluble polymerization initiator and other oil-soluble components can be added to the monomer solution.

(2) Dispersing step: The method of dispersing the monomer solution in the aqueous medium is not particularly limited, but a method of dispersing the monomer solution by mechanical energy is preferable. Preferably, the monomer solution is dispersed in oil droplets using mechanical energy in an aqueous medium obtained by dissolving a concentration of a surfactant.
This is an essential aspect in the miniemulsion method. Here, the disperser for performing oil droplet dispersion by mechanical energy is not particularly limited, for example, “Clear Mix”, an ultrasonic disperser, a mechanical homogenizer, a Mentongorin and a pressure homogenizer, and the like. Can be mentioned. Also, as the dispersed particle diameter,
10 to 1000 nm, preferably 30 to 300 n
m.

(3) Polymerization step: In the polymerization step, basically, a conventionally known polymerization method (emulsion polymerization method, suspension polymerization method,
Granulation polymerization such as seed polymerization) can be employed. An example of a preferable polymerization method is a mini-emulsion method, that is, a monomer solution is dispersed in oil droplets using mechanical energy in an aqueous medium in which a surfactant having a concentration equal to or lower than the critical micelle concentration is dissolved. A method in which a water-soluble polymerization initiator is added to the resulting dispersion to cause radical polymerization.

(4) Salting-out / fusion step: In the salting-out / fusion step, a dispersion of colorant particles is added to a dispersion of resin particles obtained by the above-mentioned polymerization step.
The colorant particles are salted out / fused in an aqueous medium. In addition, in the salting-out / fusion step, resin particles and colorant particles may be fused together with internal additive particles such as a charge control agent.

Further, in the salting out / fusing step,
Along with the resin particles containing a release agent, resin particles not containing these can also be fused. Here, as a preferred embodiment, a resin particle having an intermediate molecular weight (MP) containing a release agent, a resin particle having a low molecular weight (LP), a resin particle having a high molecular weight (HP), and a colorant particle are mixed with a salt. Deposition / fusion.

By including the release agent only in the intermediate molecular weight resin particles (MP), excellent offset resistance / fixing property is exhibited by the intermediate molecular weight resin particles (MP), and the high molecular weight resin is obtained. The offset resistance and anti-winding properties provided by the particles (HP) and the suitable fixing properties provided by the low molecular weight resin particles (LP) are not impaired.

The “aqueous medium” in the salting-out / fusion step refers to a medium whose main component (50% by mass or more) is water. Here, examples of the component other than water include an organic solvent soluble in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran.
Of these, alcohol-based organic solvents such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the resin, are particularly preferable.

The colorant particles used in the salting out / fusion step can be prepared by dispersing the colorant in an aqueous medium. The colorant dispersion treatment is performed in a state where the surfactant concentration is equal to or higher than the critical micelle concentration (CMC) in water. The dispersing machine used for the dispersion treatment of the colorant is not particularly limited, but preferably, "Clear Mix", an ultrasonic dispersing machine, a mechanical homogenizer, a pressure dispersing machine such as Menton Gorin or a pressure homogenizer, a sand grinder, a getzman mill. And a media type disperser such as a diamond fine mill. Examples of the surfactant used include the same surfactants as described above.

The colorant (particle) may be surface-modified. In the surface modification method of the colorant, the colorant is dispersed in a solvent, the surface modifier is added to the dispersion, and the system is reacted by raising the temperature of the system. After completion of the reaction, the colorant is separated by filtration, washed and filtered repeatedly with the same solvent, and then dried to obtain a colorant (pigment) treated with a surface modifier.
Is obtained.

In the salting out / fusion method, an alkali metal salt and / or a colorant are mixed in an aqueous medium in which resin particles and colorant particles are present.
Alternatively, a salting-out agent composed of an alkaline earth metal salt or the like is added as a coagulant having a critical coagulation concentration or higher, and then heated to a temperature equal to or higher than the glass transition point of the resin particles, thereby promoting salting-out and simultaneously fusing. This is the step to be performed. In this step,
An organic solvent that is infinitely soluble in water may be added.

Here, the alkali metal salt and alkaline earth metal salt as salting-out agents include lithium, potassium, sodium and the like as alkali metals, and magnesium, calcium, strontium, barium and the like as alkaline earth metals. And preferably potassium, sodium, magnesium, calcium and barium. Examples of the salt include chloride, bromide, iodine, carbonate, sulfate and the like.

Further, the organic solvent infinitely soluble in water includes methanol, ethanol, 1-propanol,
2-propanol, ethylene glycol, glycerin,
Acetone and the like can be mentioned, and alcohols of methanol, ethanol, 1-propanol and 2-propanol having 3 or less carbon atoms are preferable, and 2-propanol is particularly preferable.

In the salting-out / fusion step, it is preferable to minimize the time for which the salting-out agent is left after the addition of the salting-out agent (the time until the start of heating). That is, it is preferable that the heating of the dispersion of the resin particles and the colorant particles is started as soon as possible after the addition of the salting-out agent, so that the temperature is equal to or higher than the glass transition temperature of the resin particles. Although the reason for this is not clear, the aggregation state of the particles fluctuates due to the elapse of the standing time after salting out, and the particle size distribution becomes unstable, or the surface properties of the fused toner fluctuate. This is because a problem occurs. The time until heating starts (leaving time)
It is usually within 30 minutes, preferably within 10 minutes.
The temperature at which the salting-out agent is added is not particularly limited, but is preferably equal to or lower than the glass transition temperature of the resin particles.

In the salting out / fusing step, it is necessary to rapidly raise the temperature by heating.
Minutes or more. The upper limit of the heating rate is not particularly limited, but is preferably 15 ° C./min or less from the viewpoint of suppressing generation of coarse particles due to rapid salting out / fusion. Further, after the dispersion of the resin particles and the colorant particles reaches the temperature equal to or higher than the glass transition temperature, it is important to maintain the temperature of the dispersion for a certain period of time to continue the salting-out / fusion. . Thereby, the growth of the toner particles (aggregation of the resin particles and the colorant particles) and the fusion (the disappearance of the interface between the particles) can effectively proceed, and the durability of the finally obtained toner can be improved. Can be improved. Also, after stopping the growth of the associated particles,
The fusion by heating may be continued.

(5) Filtration / Washing Step: In this filtration / washing step, a filtration treatment for filtering out the toner particles from the dispersion liquid of the toner particles obtained in the above step, Cleaning treatment for removing extraneous matter such as a surfactant and a salting-out agent from the aggregate in the form of a liquid. here,
Examples of the filtration method include, but are not particularly limited to, a centrifugal separation method, a vacuum filtration method using a Nutsche method, a filtration method using a filter press, and the like.

(6) Drying step: This step is a step of drying the washed toner particles. Dryers used in this step include spray dryers, vacuum freeze dryers, vacuum dryers and the like, stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, rotary dryers It is preferable to use a stirring dryer. The moisture content of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less.

Incidentally, the dried toner particles are
In the case where the aggregates are aggregated by a weak attraction between particles, the aggregates may be crushed. Here, as the crushing device,
A mechanical pulverizer such as a jet mill, a Henschel mixer, a coffee mill, and a food processor can be used.

(7) Step of adding an external additive: This step is a step of adding an external additive to the dried toner particles. The equipment used to add the external additives includes
Various known mixing devices such as a turbular mixer, a Hensiel mixer, a Nauta mixer, and a V-type mixer can be used.

The toner used in the present invention may be one in which a material capable of imparting various functions as a toner material is added in addition to the colorant and the release agent. Specific examples include a charge control agent. These components can be added simultaneously with the resin particles and the colorant particles in the above-mentioned salting-out / fusion step, and can be added by various methods such as a method of including in the toner and a method of adding to the resin particles themselves. Similarly, various known charge control agents, which can be dispersed in water, can be used. In particular,
Nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.

As described above, the toner used in the present invention is an associative toner obtained by salting out / fusing resin particles containing a release agent and colorant particles in an aqueous medium. Yes, salting out the resin particles containing the release agent and the colorant particles /
By fusing, the release agent can be present in the toner particles (associative particles) with a fine domain structure, and the dispersion state (dispersion area / dispersion amount) and surface state of the release agent between the toner particles , The transfer of the release agent to the carrier is suppressed, and a stable charging property is obtained. Further, the toner used in the present invention has a shape having irregularities on the surface from the time of its production, and further, an association type obtained by fusing resin particles and colorant particles in an aqueous medium. Since the toner is a toner, the difference in shape and surface properties between toner particles is extremely small, and as a result, the surface properties tend to be uniform.
For this reason, there is little difference in fixability between toners, and good fixability can be maintained.

The toner used in the present invention has a shape coefficient variation coefficient of 16% or less, and the number of toner particles having a number variation coefficient of 27% or less in the number particle size distribution and the ratio of toner particles having no corners are 50 or less. % Or more, and the proportion of toner particles having a number variation coefficient of 27% or less in the number particle size distribution or toner particles having a shape coefficient in the range of 1.2 to 1.6 is 65 number% or more, and the shape coefficient Is 16% or less.

The shape factor of the toner is represented by the following equation, and indicates the degree of roundness of the toner particles.

[0103]

[Formula 3] Shape factor = {(maximum diameter / 2) ² × π} / projected area

Here, the maximum diameter refers to the width of a particle at which the distance between the parallel lines becomes maximum when the projected image of the toner particles on the plane is sandwiched between two parallel lines. The projection area refers to the area of the projected image of the toner particles on the plane. In the present invention, this shape factor is determined by a scanning electron microscope.
A photograph in which the toner particles were magnified by a factor of 00 was taken, and then based on the photograph, "SCANNING IMAGE A
The measurement was performed by analyzing photographic images using "NALYZER" (manufactured by JEOL Ltd.). In this case, the shape factor of the present invention was measured by using the above formula using 100 toner particles.

In the toner used in the present invention, the ratio of the toner particles having the shape factor in the range of 1.2 to 1.6 is preferably at least 65% by number, more preferably at least 70% by number. It is. When the ratio of the toner particles having the shape factor in the range of 1.2 to 1.6 is 65% by number or more, the packing density of the toner particles in the transferred toner layer is increased, and the fixing property is improved.
Offset is less likely to occur. Further, the toner particles are less likely to be crushed, so that contamination of the charging member such as a carrier is reduced, and the charging property of the toner is easily stabilized.

The method for controlling the shape factor is not particularly limited. For example, a method of spraying toner particles in a hot air flow, a method of repeatedly applying mechanical energy by an impact force in a gaseous phase in a gas phase, a method of adding a toner in a solvent that does not dissolve a toner and imparting a swirling flow, etc. There is a method in which toner particles having a shape factor of 1.2 to 1.6 are prepared and added to a normal toner so as to fall within the range of the present invention. Further, there is a method in which the overall shape is controlled at the stage of preparing a so-called polymerization toner, and the toner particles whose shape factor is adjusted to 1.2 to 1.6 are similarly added to a normal toner for adjustment. Among the above methods, a polymerization toner is preferred because it is simple as a production method and has excellent surface uniformity as compared with a pulverized toner.

The variation coefficient of the shape factor of the toner is calculated from the following equation.

[0108]

## EQU4 ## Coefficient of variation of shape coefficient = (S ₁ / K) × 100
(%)

[Wherein, S ₁ represents the standard deviation of the shape factor of 100 toner particles, and K represents the average value of the shape factors. ]

In the toner used in the present invention, the coefficient of variation of the shape factor is preferably 16% or less, more preferably 14% or less. When the variation coefficient of the shape factor is 16% or less, the gap of the transferred toner layer (powder layer) is reduced, the fixing property is improved, and the offset is less likely to occur. Further, the charge amount distribution can be made sharper, and the image quality is improved.

In order to uniformly control the shape factor and the variation coefficient of the shape factor of the toner so as not to vary between lots, resin particles (polymer particles) containing a release agent are fused and shaped. In the controlling step, it is preferable to determine an appropriate process end time while monitoring the characteristics of the toner particles (colored particles) being formed. Monitoring means that a measuring device is incorporated in-line and process conditions are controlled based on the measurement result. In other words, the measurement of the shape and the like is incorporated in-line, and the shape and the particle size are measured while sequentially sampling in the fusion step when the resin particles are salted out / fused in the aqueous medium with the colorant particles. The reaction is stopped when the shape becomes Although the monitoring method is not particularly limited, a flow type particle image analyzer FPI
A-2000 (made by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid. That is, a pump or the like is used from the reaction field to constantly monitor and measure the shape and the like, and stop the reaction when the desired shape and the like are obtained.

The number particle size distribution and the number variation coefficient of the toner used in the present invention are measured with a Coulter Counter TA-II or a Coulter Multisizer (manufactured by Coulter Inc.). In the present invention, a Coulter Multisizer was used, connected to an interface (manufactured by Nikkaki) for outputting a particle size distribution and a personal computer. The particle size distribution and the average particle size were calculated by measuring the volume and the number of toner particles having a size of 2 μm or more by using a 100 μm aperture as the aperture used in the Coulter Multisizer. The number particle size distribution represents the relative frequency of the toner particles with respect to the particle size, and the number average particle size represents the median size in the number particle size distribution. The “number variation coefficient in the number particle size distribution” of the toner is calculated from the following equation.

[0113]

## EQU5 ## Number variation coefficient = [S ₂ / D _n ] × 100
(%)

[Wherein, S ₂ represents the standard deviation in the number particle size distribution, and D _n represents the number average particle size (μm). ]

The number variation coefficient of the toner used in the present invention is preferably 27% or less, more preferably 2%.
5% or less. When the number variation coefficient is 27% or less, the gap of the transferred toner layer (powder layer) is reduced, the fixing property is improved, and the offset hardly occurs. Further, the charge amount distribution becomes sharper, the transfer efficiency is increased, and the image quality is improved.

The method of controlling the number variation coefficient of the toner is not particularly limited. For example, a method of classifying toner particles by wind force can be used, but classification in a liquid is effective for further reducing the number variation coefficient. As a method of classifying in a liquid, there is a method of separating and collecting toner particles according to a sedimentation speed difference caused by a difference in toner particle diameter by controlling a rotation speed by using a centrifugal separator.

The proportion of toner particles having no corners in the toner particles constituting the toner used in the present invention is preferably at least 50% by number, more preferably at least 70% by number. When the ratio of the toner particles having no corners is 50% by number or more, the gap of the transferred toner layer (powder layer) is reduced, the fixing property is improved, and the offset hardly occurs. In addition, the amount of toner particles that are liable to be worn or broken and the number of toner particles having a portion where charges are concentrated are reduced, the charge amount distribution becomes sharper, the chargeability is stabilized, and good image quality is formed over a long period of time. it can.

Here, “toner particles having no corners” refers to toner particles having substantially no projections on which electric charges are concentrated or projections which are easily worn by stress.
Specifically, the following toner particles are referred to as toner particles having no corners. That is, as shown in FIG.
When the major axis is L, a circle C having a radius (L / 10)
A case where the circle C does not substantially extend outside the toner particle T when the inside is rolled while being in contact with the peripheral line of the toner particle T at one point is referred to as a “toner particle having no corner”. . “Cases that do not substantially protrude” refer to cases where there are no more than one protrusion having a protruding circle. Also,
The “longer diameter of the toner particle” refers to the width of the particle at which the interval between the parallel lines is the largest when the projected image of the toner particle on the plane is sandwiched between two parallel lines. FIGS. 1B and 1C show projected images of toner particles having corners, respectively.

The measurement of the ratio of the toner particles having no corners was performed as follows. First, a photograph in which the toner particles were enlarged by a scanning electron microscope was taken, and further enlarged to 15.0.
Obtain a 00x photographic image. Next, the presence or absence of the corners is measured for this photographic image. This measurement was performed for 100 toner particles.

The method for obtaining a toner having no corners is not particularly limited. For example, as described above, as a method of controlling the shape coefficient, a method of spraying toner particles into a hot air flow, a method of repeatedly applying mechanical energy by an impact force in a gas phase, or a method of dissolving a toner It can be obtained by a method of imparting a swirling flow by adding to a solvent which is not used. In addition, in the step of stopping fusion when salting out / fusing the resin particles, there are many irregularities on the surface of the fused particles and the surface is not smooth, but the temperature in the shape control step, the number of rotations of the stirring blade and the stirring By making conditions such as time appropriate, a toner having no corners can be obtained. These conditions vary depending on the physical properties of the resin particles. For example, by setting the rotation speed higher than the glass transition temperature of the resin particles, the surface becomes smooth and a toner having no corners can be formed.

The particle diameter of the toner used in the present invention is preferably 3 to 8 μm in number average particle diameter. In the case where toner particles are formed by a polymerization method, the particle size is determined by the concentration of the coagulant, the amount of the organic solvent added, or the fusing time, and the composition of the polymer itself, in the toner manufacturing method described in detail below. Can be controlled by When the number average particle size is 3 to 8 μm, in the fixing step, toner particles having a large adhesive force that fly and adhere to the heating member to generate offset are reduced, and the transfer efficiency is increased, and the halftone The image quality is improved, and the image quality of fine lines, dots, and the like is improved.

When the particle diameter of the toner particles is D (μm), the natural logarithm lnD is plotted on the horizontal axis, and the horizontal axis is 0.23.
In the histogram showing the number-based particle size distribution divided into a plurality of classes at intervals, the relative frequency (m1) of the toner particles included in the most frequent class and the toner particles included in the class having the second highest frequency after the most frequent class Is preferably 70% or more with respect to the relative frequency (m2).

When the sum (M) of the relative frequency (m1) and the relative frequency (m2) is 70% or more, the dispersion of the particle size distribution of the toner particles becomes narrower. Thus, the occurrence of selective development can be reliably suppressed. In the present invention, the histogram showing the number-based particle size distribution includes a natural logarithm lnD (D: particle size of individual toner particles) in a plurality of classes (0 to 0.23: 0.23 to 0.23) at intervals of 0.23. 0.46: 0.46-0.
69: 0.69-0.92: 0.92-1.15: 1.
15-1.38: 1.38-1.61: 1.61-1.
84: 1.84 to 2.07: 2.07 to 2.30: 2.
30 to 2.53: 2.53 to 2.76...) Is a histogram showing the number-based particle size distribution, which is based on the following conditions. Diameter data is
The data is transferred to a computer via the / O unit, and is created by the computer using a particle size distribution analysis program.

[Measurement Conditions] (1) Aperture: 100 μm (2) Sample preparation method: electrolytic solution [ISOTON R-1
1 (manufactured by Coulter Scientific Japan)
An appropriate amount of a surfactant (neutral detergent) is added to 50 to 100 ml, and the mixture is stirred, and 10 to 20 mg of a measurement sample is added thereto. This system is prepared by subjecting it to a dispersion treatment with an ultrasonic disperser for 1 minute.

FIG. 2 is an explanatory view showing an example of the constitution of a reaction apparatus (stirring apparatus) suitably used in producing a polymerization toner for salting out / fusing resin particles. 2, a stirring tank, 3 a rotating shaft, 7 an upper material inlet, 8 a lower material inlet, and 46 and 56 stirring blades. This reaction device (stirring device) is characterized in that no obstacle such as a baffle plate that forms a turbulent flow is provided in the stirring tank 2. Regarding the configuration of the stirring blades, it is preferable that the upper-stage stirring blades have a multi-stage configuration in which the lower-stage stirring blades are disposed with an intersection angle α that precedes the rotation direction.

The shape of the stirring blade is not particularly limited as long as it does not form a turbulent flow.
As shown in (d) to (d), those formed of continuous surfaces, such as a rectangular plate, are preferable. The stirring blade 5a shown in FIG. 3 (a) has no hole, and the stirring blade 5b shown in FIG. 3 (b) has a large hole 6b in the center, and FIG. 3 (c).
The stirring blade 5c shown in FIG. 5 has a horizontally elongated middle hole 6c (slit), and the stirring blade 5d shown in FIG.
There is d (slit). Further, it may have a curved surface. Furthermore, a three-stage stirring blade may be provided, and in this case, the middle hole formed in the upper stirring blade and the middle hole formed in the lower stirring blade may be different from each other. , May be the same.

According to such a reaction apparatus, by controlling the temperature, the number of revolutions, and the time in the fusing step and the shape control step, it is possible to form a toner having a desired shape coefficient and a uniform shape distribution. Can be. The reason for this is that when fusion is performed in a place where a laminar flow is formed, strong stress is not applied to the particles that are undergoing aggregation and fusion (association or aggregated particles) and the flow is accelerated in a laminar flow. It is presumed that as a result of the uniform temperature distribution in the stirring tank, the shape distribution of the fused particles becomes uniform. Further, the fused particles gradually become spherical by heating and stirring in the subsequent shape control step, and the shape of the toner particles can be arbitrarily controlled.

The developer of the present invention comprises an image forming method including the step of fixing a recording material on which a toner image is formed by passing the recording material between a heating roller and a pressure roller constituting a fixing device. Image forming method). As a suitable fixing method used in the present invention, a so-called contact heating method can be used. In particular, examples of the contact heating method include a heat and pressure fixing method, a heat roll fixing method, and a pressure contact heat fixing method in which fixing is performed by a rotating pressing member including a fixedly disposed heating element.

FIG. 4 is a sectional view showing an example of a fixing device used in the present invention. This fixing device includes a heating roller 10 and a pressure roller 20 that comes into contact with the heating roller 10. In FIG. 4, T is a toner image formed on a recording material (also referred to as an image support, typically a transfer paper).

The heating roller 10 has a core metal 11 on the surface of which a coating layer 12 made of a fluororesin is formed, and includes a heating member 13 made of a linear heater.

The core metal 11 is made of a metal or an alloy thereof, and has an inner diameter of 10 to 70 mm. The material constituting the metal core 11 is not particularly limited, but examples thereof include metals such as iron, aluminum, and copper, and alloys thereof. The thickness of the cored bar 11 is set to 0.1 to 2 mm, and demand for energy saving (thinning)
And the strength (depending on the constituent material). For example, in order to maintain a strength equivalent to that of a 0.57 mm iron core with an aluminum core, the wall thickness must be 0.8 mm.

The fluororesin constituting the coating layer 12 includes PTFE (polytetrafluoroethylene) and P
FA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) and the like can be exemplified. The thickness of the coating layer 12 made of fluororesin is 10 to 50
0 μm, preferably 20 to 200 μm.
If the thickness of the coating layer 12 made of fluororesin is less than 10 μm, the function as the coating layer cannot be sufficiently exhibited, and the durability as a fixing device cannot be secured. On the other hand, there is a problem that the surface of the coating layer having a thickness of more than 500 μm is easily scratched by paper dust, and toner or the like adheres to the scratched portion, thereby causing image stains.

As the elastic material constituting the coating layer 12, it is preferable to use silicone rubber and silicone sponge rubber having good heat resistance such as LTV, RTV, HTV and the like. The thickness of the coating layer 12 made of an elastic body is 0.1 to 30 mm, preferably 0.1 to 20 mm.
It is said. The Asker C hardness of the elastic body constituting the coating layer 12 is less than 80 °, preferably less than 60 °. When the thickness of the coating layer 12 is less than 0.1 mm and when the Asker C hardness of the elastic body constituting the coating layer 12 exceeds 80 °, the fixing nip cannot be increased, and It is difficult to exhibit the effect of soft fixing such as the effect of improving color reproducibility by the toner layer at the interface.

As the heating member 13, for example, a halogen heater can be suitably used. The number of the heating members 13 is not particularly limited, and a configuration in which a plurality of heating members are included and the heat distribution area can be changed according to the size (width) of the transfer paper passing therethrough can be employed. For example, a configuration in which a central region heating halogen heater for heating a central region on the surface of the heating roller, and an end region heating halogen heater for heating an end region on the surface of the heating roller are provided. can do. In the heating roller having such a configuration, for example, when a narrow transfer paper is passed, only the central area heating halogen heater needs to be energized. It is sufficient to energize the halogen heater for heating the region.

The pressure roller 20 has a coating layer 22 made of an elastic material formed on the surface of a metal core 21. Coating layer 22
The elastic body is not particularly limited, and includes various soft rubbers such as urethane rubber and silicone rubber and sponge rubber.
It is preferable to use the silicone rubber and the silicone sponge rubber exemplified as those constituting the first coating layer 12.

The thickness of the coating layer 22 is 0.1 to 30 mm, preferably 0.1 to 20 mm. The Asker C hardness of the elastic body constituting the coating layer 22 is less than 70 °, preferably less than 60 °. Coating layer 22
Is less than 0.1 mm, and the coating layer 22
When the Asker C hardness of the elastic body constituting 70 ° exceeds 70 °, the fixing nip cannot be increased, and for example, soft fixing such as an effect of improving color reproducibility by a smoothed interface toner layer is achieved. It cannot be effective.

The material forming the core 21 is not particularly limited, but may be a metal such as aluminum, iron, copper or the like, or an alloy thereof.

The contact load (total load) between the heating roller 10 and the pressure roller 20 is usually 40 to 350 N, preferably 50 to 300 N, more preferably 50 to 300 N.
２５０250N. This contact load is applied to the heating roller 1
It is defined in consideration of the strength of 0 (thickness of the metal core 11). For example, in the case of a heating roller having a metal core of 0.3 mm, it is preferably 250 N or less.

Further, from the viewpoint of offset resistance and fixing property, the nip width is preferably 4 to 10 mm.
The surface pressure of the nip is 0.6 × 10 ⁵ Pa to 1.5 × 10 ⁵
It is preferably ⁵ Pa.

An example of the fixing condition by the fixing device shown in FIG. 4 is as follows. Fixing temperature (surface temperature of heating roller 10)
Is 150 to 210 ° C., and the fixing linear velocity is 80 to 640 m.
m / sec.

The fixing device used in the present invention may be provided with a cleaning mechanism as needed. In this case, as a method of supplying the silicone oil to the upper roller (heating roller) of the fixing unit, a method of supplying and cleaning with a pad, a roller, a web, or the like impregnated with the silicone oil can be used. As the silicone oil, those having high heat resistance are used, and polydimethyl silicone, polyphenylmethyl silicone, polydiphenyl silicone and the like are used. Since those with low viscosity have a large outflow during use, the viscosity at 20 ° C. is 1%.
Those having a pressure of １００100 Pa · s are preferably used.

[0142]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following, “parts” means “parts by mass”.

Carrier Production Example 1 300 parts of magnetic powder (spherical magnetic powder having a number average primary particle diameter of 0.2 μm) was added to 100 parts of styrene-acryl resin, melt-kneaded, and then crushed and classified to obtain a volume. Average particle size (Dv) of 46
μm, a carrier having a number average particle diameter (Dn) of 34 μm and a Dv / Dn of 1.35 were obtained. This is referred to as “carrier 1”.

Carrier Production Example 2 Polyester Resin 100
Parts magnetic powder (number average primary particle diameter is 0.1
5 μm cubic magnetic powder), melt-kneaded, and then pulverized and classified to obtain a volume average particle diameter (Dv) of 35 μm.
m, a carrier having a number average particle size (Dn) of 28 μm and a Dv / Dn of 1.25 was obtained. This is called “carrier 2”.

Carrier Production Example 3 The number-average primary particle diameter was 0.1%.
A treated magnetic powder was obtained by treating 100 parts of a 16 μm spherical magnetic powder with 1 part of trimethoxyoctylsilane.
400 parts of this treated magnetic powder and 37% formalin 7
Put 5 parts and 50 parts of phenol in a four-necked flask,
Further, 15 parts of 25% aqueous ammonia and 50 parts of water are added, and the temperature is raised to 85 ° C. for 60 minutes with stirring, and then a curing reaction is performed at 85 ° C. for 120 minutes, whereby the spherical magnetic powder is dispersed in the phenol resin. I got a career. This is called “carrier 3”. This carrier 3
Had a volume average particle size (Dv) of 33 μm, a number average particle size (Dn) of 29 μm, and Dv / Dn of 1.14.

Carrier Production Example 4 Volume average particle size (Dv) is 60 μm, number average particle size (Dn) is 39 μm, Dv / D
A solution obtained by dissolving 2 parts of a styrene-acrylic resin in toluene was spray-dried to 100 parts of a copper-zinc ferrite carrier core having an n of 1.54 to obtain a carrier coated with a styrene-acrylic resin. This is called “carrier 4”.

<Production of Toner> [Preparation Example of High Molecular Weight Latex HP-1] 500 equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device.
In a 0 ml separable flask, anionic surfactant (sodium dodecyl sulfonate: SDS) 7.08 was added.
g of a surfactant solution (aqueous medium) in 2760 g of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.
A polymerization initiator (potassium persulfate:
An initiator solution in which 0.42 g of KPS (KPS) was dissolved in 200 g of ion-exchanged water was added and the temperature was adjusted to 75 ° C. Then, a simple solution composed of 115.1 g of styrene, 42.0 g of n-butyl acrylate and 10.9 g of methacrylic acid was added. 1-mer mixture
Latex was added thereto over a period of time, and the system was heated and stirred at 75 ° C. for 2 hours to prepare a latex (a dispersion of resin particles having a high molecular weight). This is called "latex (HP
-1) ". The peak molecular weight of the resin particles constituting this latex (HP-1) was 518,000.

[Preparation Example of High Molecular Weight Latex HP-2]
A latex was prepared in the same manner as in Preparation Example HP-1, except that the reaction temperature was changed to 85 ° C in Preparation Example HP-1. This is designated as "latex (HP-2)". The peak molecular weight of the resin particles constituting the latex (HP-2) was 421,000.

[Preparation Example of High Molecular Weight Latex HP-3]
A latex was prepared in the same manner as in Preparation Example HP-1, except that the amount of the polymerization initiator (KPS) added was changed to 0.84 g in Preparation Example HP-1. This is designated as "latex (HP-3)". The peak molecular weight of the resin particles constituting the latex (HP-3) was 316,000.

[Preparation Example of High Molecular Weight Latex HP-4]
Latex (high molecular weight resin) was prepared in the same manner as in Preparation Example HP-1, except that the amount of potassium persulfate (KPS) was changed to 0.84 g and the reaction temperature was changed to 90 ° C. A dispersion of particles) was prepared. This is designated as "latex (HP-4)". The peak molecular weight of the resin particles constituting this latex (HP-4) is 19
It was 3,000.

[Example of Preparation of Intermediate Molecular Weight Latex MP-1] The above formula (W1
9) (hereinafter referred to as “exemplified compound (W1
9) ". 72.0 g of styrene 383.6
g, 140.0 g of n-butyl acrylate, 36.4 g of methacrylic acid and 5.6 g of dodecyl mercaptan, and the mixture was heated to 80 ° C. and dissolved to prepare a monomer solution. On the other hand, an anionic surfactant (SD) was placed in a 5000 ml separable flask equipped with a stirring device, a temperature sensor, a cooling pipe, and a nitrogen introducing device.
S) A surfactant solution (aqueous medium) in which 1.6 g was dissolved in 2000 g of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C.

Next, the monomer solution (80 ° C.) was added to the surfactant solution (80 ° C.) using a mechanical dispersing machine “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path. The emulsion was mixed and dispersed to prepare an emulsion in which emulsified particles (oil droplets) having a uniform dispersed particle diameter were dispersed. Next, 19.1 g of a polymerization initiator (KPS) was added to the dispersion.
Was dissolved in 240 g of ion-exchanged water, and 750 g of ion-exchanged water were added.
The polymerization reaction was carried out by heating and stirring over time to prepare a latex (a dispersion of resin particles having an intermediate molecular weight and containing the exemplified compound (W19)). This is designated as "latex (MP-1)". This latex (MP-
The peak molecular weight of the resin particles constituting 1) is 103,00.
It was 0.

[Preparation Example of Intermediate Molecular Weight Latex MP-2] Same as Preparation Example MP-1, except that the amount of dodecyl mercaptan constituting the monomer mixture was changed to 8.3 g in Preparation Example MP-1. To prepare a latex (a dispersion of resin particles of intermediate molecular weight containing the exemplified compound (W19)). This is designated as "latex (MP-2)". The peak molecular weight of the resin particles constituting the latex (MP-2) was 81,000.

[Preparation Example of Intermediate Molecular Weight Latex MP-3] In Preparation Example MP-1, the amount of Exemplified Compound (19) added to the monomer mixture was changed to 144.0 g, and n was replaced with n instead of dodecyl mercaptan. Latex (dispersion liquid of intermediate molecular weight resin particles containing Exemplified Compound (W19)) in the same manner as in Preparation Example MP-1 except that 5.6 g of -octyl-3-mercaptopropionate was used.
Was prepared. This is designated as "latex (MP-3)". The peak molecular weight of the resin particles constituting the latex (MP-3) was 103,000.

[Preparation Example of Intermediate Molecular Weight Latex MP-4] In Preparation Example MP-1, a compound represented by the above formula (W21) (hereinafter referred to as “W21”) is used instead of Exemplified Compound (W19).
It is referred to as "exemplary compound (W21)." A latex (dispersion liquid of intermediate molecular weight resin particles containing Exemplified Compound (W21)) was prepared in the same manner as in Preparation Example MP-1, except that 72.0 g was added to the monomer mixture. This is designated as "latex (MP-4)". This latex (MP
-4), the peak molecular weight of the resin particles is 102,0
00.

[Preparation Example of Intermediate Molecular Weight Latex MP-5] In Preparation Example MP-1, a compound represented by the above formula (W18) (hereinafter referred to as “W18”) is used instead of Exemplified Compound (W19).
It is referred to as "exemplary compound (W18)". A latex (dispersion liquid of intermediate molecular weight resin particles containing exemplified compound (W18)) was prepared in the same manner as in Preparation Example MP-1, except that 72.0 g was added to the monomer mixture. This is designated as “latex (MP-5)”. This latex (MP
The peak molecular weight of the resin particles constituting -5) is 102,0.
00.

[Preparation Example of Low Molecular Weight Latex LP-1]
An anionic surfactant (SDS) 6 was added to a flask equipped with a stirrer, temperature sensor, cooling tube, and nitrogen introduction device.
A surfactant solution (aqueous medium) in which 0 g was dissolved in 5000 g of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.
To this surfactant solution was added a polymerization initiator (KPS) 22.8.
g of ion-exchanged water in 200 g of an initiator solution, and while maintaining the temperature at 80 ° C., styrene 850
g, butyl acrylate 252 g, methacrylic acid 98 g
And a monomer mixture comprising 32 g of n-octyl-3-mercaptopropionate was added dropwise over 1 hour, and the system was heated and stirred at 80 ° C. for 2 hours to obtain a latex (low molecular weight resin particles). Dispersion)
Was prepared. This is designated as "latex (LP-1)". The peak molecular weight of the resin particles constituting the latex (LP-1) was 18,000.

[Production Example of Colorant Dispersion Bk] 90 g of sodium n-dodecyl sulfate was dissolved in 1600 ml of ion-exchanged water with stirring. While stirring the solution, 200 g of carbon black “Mogal L” (manufactured by Cabot) was gradually added, and then a stirring device “CLEARMIX” equipped with a high-speed rotating rotor (manufactured by M Technic Co., Ltd.)
To prepare a dispersion of colorant particles (hereinafter referred to as “colorant dispersion (Bk)”). When the particle size of the colorant particles in the colorant dispersion liquid (Bk) was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the weight average particle size was 101 nm. .

[Production of colored particles 1Bk] 3000 g of the above high molecular weight latex (HP-1), 2500 g of the intermediate molecular weight latex (MP-1), 6000 g of the low molecular weight latex (LP-1), and 2,000 g of ion-exchanged water
And 1800 g of the colorant dispersion liquid (Bk) were stirred in a reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. After adjusting the internal temperature to 30 ° C., a 5N aqueous solution of sodium hydroxide was added to the solution to adjust the pH to 1.
Adjusted to 1.0. Next, an aqueous solution in which 526 g of magnesium chloride hexahydrate was dissolved in 720 ml of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, heating was started, and the system was cooled to 9 for 6 minutes.
The temperature was raised to 0 ° C. at a rate of 10 ° C./min.

In this state, the "Coulter counter TA-
II ", the particle diameter of the associated particles was measured, and the volume average particle diameter was 6.
At 5 μm, particle growth was stopped by adding an aqueous solution in which 1150 g of sodium chloride was dissolved in 7000 ml of ion-exchanged water.
The salting out / fusion was continued by heating and stirring over time. Thereafter, the mixture was cooled to 30 ° C. under the condition of 8 ° C./min, pH was adjusted to 2.0 by adding hydrochloric acid, and stirring was stopped. The formed associated particles were filtered, washed repeatedly with ion-exchanged water, and then dried with warm air at 40 ° C. to obtain colored particles. The colored particles thus obtained are referred to as “colored particles 1Bk”.

[Production of colored particles 2Bk to 11Bk] According to the formulation shown in Table 1 below, except that at least one of the type of latex used (the amount used is the same), the aging temperature and the aging time was changed. Colored particles containing a release agent were obtained in the same manner as in Example 1Bk. The thus obtained colored particles are referred to as “colored particles 2Bk” to “colored particles 1”.
1Bk "and" comparative colored particles 1bk ".

[Production of comparative colored particles 1Bk] 0.5 g of anionic surfactant (SDS) was added to 400 parts of ion-exchanged water.
140 g of the exemplary compound (W19) dissolved by heating was ultrasonically dispersed under a temperature condition of 85 ° C. in a surfactant solution dissolved in g. This dispersion is referred to as “release agent dispersion”. Colored particles containing a release agent were obtained by treating in the same manner as in the production of the colored particles 1Bk, except that this release agent dispersion was used simultaneously with the colorant dispersion (Bk).
The colored particles are referred to as “comparative colored particles 1Bk”.

[0163]

[Table 1]

As shown in Table 2, the above colored particles 1Bk
In the preparation of the colorant dispersion, the dye C.I. I. Solvent Yellow 9
Colored particles obtained in the same manner as those described above except that pigment No. 3 was used were referred to as “colored particles Y”, and similarly, colored particles obtained using a pigment (CI Pigment Red 122) were referred to as “colored particles M”. And a pigment (CI Pigment Blue 1)
The colored particles obtained using 5: 3) are referred to as “colored particles C”.

[0165]

[Table 2]

The colored particles 1Bk obtained as described above
-11Bk, comparative colored particles 1bk, colored particles 1Y, colored particles 1M, colored particles 1C, comparative colored particles 1y, comparative colored particles 1m, and comparative colored particles 1c, respectively.
Shape characteristics and particle size distribution characteristics were measured. The results are shown in Table 3 below. The comparative coloring particles 1Y to 1C are obtained by simultaneously adding a release agent dispersion, similarly to the comparative coloring particles 1Bk.

[0167]

[Table 3]

Table 4 shows the status of each of the colored particles.

[0169]

[Table 4]

To each of the above colored particles and comparative colored particles, hydrophobic silica (having a number average primary particle diameter of 10 nm and a degree of hydrophobicity of 63) was added at a ratio of 1.0% by mass. Hydrophobic titanium oxide (having a number average primary particle diameter of 25 nm and a degree of hydrophobicity of 60) was added at a ratio of 1.2% by mass, and mixed with a Henschel mixer to obtain toner particles. The shape and particle size of these toner particles were not changed by the addition of hydrophobic silica and hydrophobic titanium oxide.

Next, according to the formulation shown in Table 5 below, each of the colored particles to which the hydrophobic silica and the hydrophobic titanium oxide were added and one of the above carriers 1 to 4 were mixed, so that the toner concentration was 5 mass%. % Developer was prepared.

[0172]

[Table 5]

<Examples 1 to 13 and Comparative Examples 1 and 2> The black developers 1 to 13 thus obtained, the Y developer,
A digital copying machine “7075” having a toner recycling system in which, for each of the M developer, the C developer, and the comparative developer, the toner collected by cleaning is returned to the developing device by the recycling system and reused.
(Manufactured by Konica Corporation) at a temperature of 32 ° C. and a relative humidity of 85
% In a high-temperature and high-humidity environment.
Perform a live-action test to print 200,000 sheets intermittently.
The image density was evaluated for the image formed on the 1st sheet and the image formed on the 150,000th sheet, and the fog density was evaluated for the image formed on the first sheet and the image formed on the 200,000th sheet. Was evaluated. Table 6 shows the results.

Method for Measuring Image Density and Fog Density The image density was evaluated by measuring the image density of a solid black portion of a fixed image with a Macbeth reflection densitometer “RD-918” and evaluating the absolute density. The fog density is measured by measuring the image density of a white background portion of a fixed image with a Macbeth reflection densitometer “RD-918”,
It was evaluated by the relative concentration to 0).

In the digital copying machine used in the above-described actual copying test, the photosensitive member is cleaned by a blade system. The fixing device is a pressure fixing type heat fixing device as shown in FIG. 4, and its specific configuration is as follows. The surface of a core metal (inner diameter 40 mm, wall thickness 1.0 mm, overall width 310 mm) made of a cylindrical aluminum alloy is coated with a PFA (tetrafluoroethylene-perfluoroalkylvinyl ether copolymer) tube (thickness 12).
0 μm), a heating roller having a built-in heater in the center, and a core metal (inner diameter of 40 m) made of cylindrical iron.
m, a thickness of 2.0 mm) and a pressure roller having a sponge-like silicone rubber (Asker C hardness of 48 °, thickness of 2 mm) covered with a total load of 150 N to make a 5.8 mm width. Nip is formed.

The fixing temperature of the fixing device was controlled to a set temperature of 175 ° C. by the surface temperature of the heating roller, and the fixing device was used under the condition that the printing linear velocity was set to 250 mm / sec. Further, this fixing device has a silicone oil supply mechanism based on a web-type supply system impregnated with silicone oil. Polydiphenyl silicone oil (having a viscosity of 10 Pa · s at 20 ° C.) of 0.2 mg / A4 The conditions were such that the coating amount was supplied.

[0177]

[Table 6]

As is clear from the results in Table 6, the developer according to the present invention can obtain excellent image forming properties, whereas the comparative black developer 1 in Comparative Example 1 has no pause. Fixing offset stain on back side of first sheet 4
It occurred after 10,000 sheets, and furthermore, it was found that the toner was stained on the paper when the paper was rubbed, which was not practical. Further, in the comparative black developer 1, the image density was considerably reduced in the 150,000th sheet image, and the fogging occurred in the 200,000th image. In this case, the image density is remarkably reduced and fogging is frequently generated.

<Example 14 and Comparative Examples 3 and 4> In these examples, the following combinations of developers were used. Example 14 Combination of Black Developer 1, Y Developer 1, M Developer 1 and C Developer 1 Comparative Example 3 Comparative Black Developer 1, Comparative Y Developer 1, Comparative M Developer Combination of 1 and Comparative C Developer 1 Comparative Example 4 Combination of Comparative Black Developer 2, Comparative Y Developer 2, Comparative M Developer 2 and Comparative C Developer 2 Using a color copying machine of the intermediate transfer method, a real-life test to print 50,000 sheets of a document with a full-color pixel rate of 25% continuously in a normal temperature and high humidity environment at a temperature of 25 ° C and a relative humidity of 80%. The color difference was evaluated for the image formed on the first sheet and the image formed on the 50,000 sheet. Table 7 shows the results. The evaluation of the color difference was performed by comparing the color of the solid image portion of the secondary color (red, blue, green) in each of the first formed image and the 50,000-th formed image with “Macbeth Color-E”.
ye7000 ", and the color difference was calculated using the CMC (2: 1) color difference equation. If the color difference obtained by the CMC (2: 1) color difference equation is 5 or less, it can be said that the change in the tint of the formed image is acceptable.

Here, the color copier is Y / M / C / B
k is arranged around the stacked photoreceptor, and after developing each color on the photoreceptor, transferring each color onto the intermediate transfer body, forming a color toner image on the intermediate transfer body, and then using the recording material. It has an intermediate transfer member for transferring to a certain transfer paper. The photoconductor was cleaned by a blade cleaning method. As the fixing method, a pressure fixing type heat fixing device as shown in FIG. 4 was used. The specific configuration is as follows. A core made of a cylindrical aluminum alloy (inner diameter 40 mm, wall thickness 1.0 mm, overall width 310 m
m) is coated with a tube of PFA (tetrafluoroethylene-perfluoroalkylvinyl ether copolymer) (thickness: 120 μm), and comprises a heating roller with a built-in heater in the center and a cylindrical iron. The surface of the core metal (inner diameter 40 mm, wall thickness 2.0 mm) is sponge-like silicone rubber (Asker C hardness 48 °, thickness 2 m)
The nip having a width of 5.8 mm is formed by contacting the pressure roller coated with m) with a total load of 150 N.

The fixing temperature of this fixing device was controlled at a set temperature of 175 ° C. by the surface temperature of the heating roller, and the printing was performed under the condition that the linear velocity of printing was set at 250 mm / sec. Further, this fixing device has a silicone oil supply mechanism based on a web-type supply system impregnated with silicone oil, and is prepared by adding 0.6 mg / A4 of polydiphenyl silicone oil (having a viscosity at 20 ° C. of 10 Pa · s). The conditions were such that the coating amount was supplied.

[0182]

[Table 7]

As is clear from the results in Table 7, Example 1
4, it was confirmed that the color developer of the present invention can stably form a high-quality color image with a small color difference over a long period of time. On the other hand, in the comparative color developers of Comparative Examples 3 and 4, the color difference was large, and the formed color image was inferior in color reproducibility. In particular, in Comparative Example 4, when the number of sheets exceeded 10,000 sheets, stains of the fixing offset began to occur on the back surface of the first sheet after the pause, and the toner was transferred to the transfer sheet in a state where the sheet was rubbed. It is apparent that this is not practical due to the occurrence of dirt in the image.

[0184]

According to the developer of the present invention, it is composed of an associative toner obtained by salting out / fusing resin particles containing a release agent and colorant particles, and a specific carrier. As a result, transfer of the release agent to the carrier and adhesion thereof are suppressed, and stable charging properties are obtained. As a result, a high-quality image free from image contamination can be stably formed for a long period of time. According to the image forming method of the present invention, a high-quality image free from image contamination can be stably formed for a long period of time.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram showing a projected image of a toner particle having no corner, and FIGS. 1B and 1C are explanatory diagrams showing a projected image of a toner particle having a corner.

FIG. 2 is an explanatory diagram showing an example of a configuration of a reaction apparatus used for forming a laminar flow.

FIG. 3 is an explanatory view showing a specific example of the shape of a stirring blade.

FIG. 4 is an explanatory cross-sectional view illustrating a configuration example of a fixing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchange jacket 2 Stirring tank 3 Rotating shaft 7 Upper material input port 8 Lower material input port 46, 56 Stirrer blades 5a, 5b, 5c, 5d Stirrer blades 6b, 6c, 6d Inside hole (slit) α intersection angle DESCRIPTION OF SYMBOLS 10 Heating roller 11 Core 12 Coating layer 13 Heating member 20 Pressure roller 21 Core 22 Coating layer T Toner image

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Meisho Shirase 2970, Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Hiroshi Yamazaki 2970, Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Invention Person Hiroyuki Yamada 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation In-house F-term (reference) 2H005 AA06 AA15 AB03 BA03 CA14 CA30 EA05 EA10

Claims (28)

[Claims] 1. An electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier, wherein the toner comprises resin particles containing a release agent in a binder resin and a colorant. Which is obtained by salting out / fusing the particles and
The release agent comprises a crystalline ester compound represented by the following general formula (1), wherein the carrier comprises at least magnetic powder particles dispersed in a resin. Developer. Embedded image 2. An electrostatic image developer comprising: a toner containing at least a resin, a release agent and a colorant; and a carrier, wherein the toner comprises a resin particle containing a release agent in a binder resin and a colorant. Which is obtained by salting out / fusing the particles and
The release agent comprises a crystalline ester compound represented by the general formula (1) according to claim 1, and has a shape coefficient of variation coefficient of 16% or less, and a number variation coefficient in a number particle size distribution. Wherein the carrier is at least magnetic powder particles dispersed in a resin. 3. The toner has a shape factor of 1.2 to 1.
3. The electrostatic image developer according to claim 2, wherein the ratio of the toner particles in the range of 6 is 65% by number or more. 4. The electrostatic image developer according to claim 2, wherein the toner has a ratio of toner particles having no corners of 50% by number or more. 5. The electrostatic image developer according to claim 2, wherein the toner has a number average particle diameter of the toner particles of 3 to 8 μm. 6. The toner according to claim 1, wherein the particle diameter of the toner particles is D.
(Μm), the natural logarithm lnD is defined as the horizontal axis, and the horizontal axis indicates the number-based particle size distribution obtained by dividing the horizontal axis into a plurality of classes at intervals of 0.23. And the sum (M) of the relative frequency (m1) of the toner particles and the relative frequency (m2) of the toner particles included in the class having the second highest frequency after the mode is 70% or more. The electrostatic image developer according to claim 2. 7. An electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier, wherein the toner comprises resin particles containing a release agent in a binder resin and a colorant. Which is obtained by salting out / fusing the particles and
The release agent is composed of the crystalline ester compound represented by the general formula (1) according to claim 1, and the ratio of toner particles having no corners is 50% by number or more, and An electrostatic image developer comprising: toner particles having a number variation coefficient of 27% or less; and a carrier in which at least magnetic powder particles are dispersed in a resin. 8. The toner has a shape factor of 1.2 to 1.
8. The electrostatic image developer according to claim 7, wherein the toner has a ratio of the toner particles in the range of 6 to 65% by number or more. 9. The electrostatic image developer according to claim 7, wherein the toner has a number average particle diameter of the toner particles of 3 to 8 μm. 10. The toner according to claim 1, wherein the particle diameter of the toner particles is D.
(Μm), the natural logarithm lnD is defined as the horizontal axis, and the horizontal axis indicates the number-based particle size distribution obtained by dividing the horizontal axis into a plurality of classes at intervals of 0.23. And the sum (M) of the relative frequency (m1) of the toner particles and the relative frequency (m2) of the toner particles included in the class having the second highest frequency after the mode is 70% or more. The electrostatic image developer according to claim 7. 11. An electrostatic image developer comprising a toner containing at least a resin, a release agent and a colorant, and a carrier, wherein the toner comprises resin particles containing a release agent in a binder resin and a colorant. Which is obtained by salting out / fusing the particles and
The release agent comprises the crystalline ester compound represented by the general formula (1) according to claim 1, and the ratio of the toner particles having a shape factor in the range of 1.2 to 1.6 is determined. It is composed of toner particles having a number coefficient of 65% or more and a variation coefficient of the shape coefficient of 16% or less, and the carrier is at least magnetic powder particles dispersed in a resin. Charge image developer. 12. The electrostatic image developer according to claim 11, wherein the toner has a ratio of toner particles having no corners of 50% by number or more. 13. The electrostatic image developer according to claim 11, wherein the toner has a number average particle diameter of the toner particles of 3 to 8 μm. 14. The toner according to claim 1, wherein the particle diameter of the toner particles is D.
(Μm), the natural logarithm lnD is defined as the horizontal axis, and the horizontal axis indicates the number-based particle size distribution obtained by dividing the horizontal axis into a plurality of classes at intervals of 0.23. And the sum (M) of the relative frequency (m1) of the toner particles and the relative frequency (m2) of the toner particles included in the class having the second highest frequency after the mode is 70% or more. An electrostatic image developer according to any one of claims 11 to 13. 15. A recording material on which a toner image developed by an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier is formed by a heating roller and a pressure roller. The toner is obtained by salting out / fusing resin particles containing a release agent and colorant particles into a binder resin. So,
The image forming method, wherein the release agent comprises a crystalline ester compound represented by the following general formula (1), and the carrier comprises at least magnetic powder particles dispersed in a resin. . Embedded image 16. A recording material on which a toner image developed by an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant and a carrier is formed by a heating roller and a pressure roller. The toner is obtained by salting out / fusing resin particles containing a release agent and colorant particles into a binder resin. So,
The release agent comprises a crystalline ester compound represented by the general formula (1) according to claim 1, and has a shape coefficient of variation coefficient of 16% or less, and a number variation coefficient in a number particle size distribution. Wherein the carrier is at least magnetic powder particles dispersed in a resin. 17. The toner having a shape factor of 1.2 to 1.2.
17. The image forming method according to claim 16, wherein the ratio of toner particles in the range of 1.6 is 65% by number or more. 18. The image forming method according to claim 16, wherein the toner has a ratio of toner particles having no corners of 50% by number or more. 19. The image forming method according to claim 16, wherein the toner has a number average particle diameter of toner particles of 3 to 8 μm. 20. The toner according to claim 1, wherein the particle diameter of the toner particles is D.
(Μm), the natural logarithm lnD is set as the horizontal axis, and the horizontal axis indicates the number-based particle size distribution obtained by dividing the horizontal axis into a plurality of classes at intervals of 0.23. Is a toner having a sum (M) of 70% or more of the relative frequency (m1) of the toner particles and the relative frequency (m2) of the toner particles included in the class having the second highest frequency after the mode. The image forming method according to claim 16. 21. A recording material on which a toner image developed by an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant, and a carrier is formed by a heating roller and a pressure roller. The toner is obtained by salting out / fusing resin particles containing a release agent and colorant particles into a binder resin. So,
The release agent is composed of the crystalline ester compound represented by the general formula (1) according to claim 1, and the ratio of toner particles having no corners is 50% by number or more, and An image forming method comprising: toner particles having a number variation coefficient of 27% or less; and a carrier in which at least magnetic powder particles are dispersed in a resin. 22. The toner having a shape factor of 1.2 to
22. The image forming method according to claim 21, wherein the toner is a toner in which the ratio of toner particles in the range of 1.6 is 65% by number or more. 23. The image forming method according to claim 21, wherein the toner has a number average particle diameter of the toner particles of 3 to 8 μm. 24. The toner according to claim 1, wherein the particle diameter of the toner particles is D.
(Μm), the natural logarithm lnD is defined as the horizontal axis, and the horizontal axis indicates the number-based particle size distribution obtained by dividing the horizontal axis into a plurality of classes at intervals of 0.23. And the sum (M) of the relative frequency (m1) of the toner particles and the relative frequency (m2) of the toner particles included in the class having the second highest frequency after the mode is 70% or more. The image forming method according to any one of claims 21 to 23. 25. A recording material on which a toner image developed by an electrostatic image developer comprising at least a toner containing a resin, a release agent and a colorant and a carrier is formed.
In an image forming method including a step of fixing by passing between a heating roller and a pressure roller, the toner salt-outs / fuses resin particles containing a release agent and colorant particles in a binder resin. Is obtained by letting
The release agent comprises the crystalline ester compound represented by the general formula (1) according to claim 1, and the ratio of the toner particles having a shape factor in the range of 1.2 to 1.6 is determined. An image characterized by comprising toner particles having a number coefficient of 65% or more and a coefficient of variation of a shape coefficient of 16% or less, wherein the carrier is at least magnetic powder particles dispersed in a resin. Forming method. 26. The image forming method according to claim 25, wherein the toner has a ratio of toner particles having no corners of 50% by number or more. 27. The image forming method according to claim 25, wherein the toner has a number average particle diameter of the toner particles of 3 to 8 μm. 28. The toner according to claim 18, wherein the particle diameter of the toner particles is D.
(Μm), the natural logarithm lnD is defined as the horizontal axis, and the horizontal axis indicates the number-based particle size distribution obtained by dividing the horizontal axis into a plurality of classes at intervals of 0.23. And the sum (M) of the relative frequency (m1) of the toner particles and the relative frequency (m2) of the toner particles included in the class having the second highest frequency after the mode is 70% or more. The image forming method according to any one of claims 25 to 27.