JP2006267248A - Electrostatic charge image developing toner and method for manufacturing the same, electrostatic charge image developer, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner which is excellent in peelability and fixing characteristics in a contact heat fixing system, provides satisfactory image quality, and is excellent in toner storage property and blocking resistance particularly in a high temperature and high humidity environment, and a method for manufacturing the same, and further, an electrostatic charge image developer and image forming method using the electrostatic charge image developing toner. <P>SOLUTION: The electrostatic charge image developing toner containing at least a binder resin, a colorant, and a release agent contains, as the release agent, an ethylene-vinyl acetate copolymer and polyalkylene. The maximal value of the endothermic peak determined from the differential scanning thermal analysis of the ethylene-vinyl acetate copolymer and the polyalkylene is 75 to 100°C and the difference between the degree of the aggregation after storage for 20 hours at the temperature 55°C and humidity 60% of the toner particles and the degree of the aggregation at ordinary temperature is 10 to 35%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrostatic charge image developing toner used when developing an electrostatic charge image formed by an electrophotographic method or an electrostatic recording method with a developer, and a method for producing the same.

  In electrophotography, a two-component development method comprising a toner and a carrier and a one-component developer method containing a magnetic material are known as methods for visualizing an electric latent image. The agent method has become mainstream. Due to recent energy savings and high-speed suitability, toners with sufficient fixability at lower temperatures are required. However, the contact heating fixing method tends to cause offset to the heat roll, and there is a problem of compatibility between fixability and offset resistance. It has become.

To solve the above problems, a toner using a resin having a maximum value in a region having a low molecular weight and a high molecular weight as a binder resin (see Patent Document 1), and a desorbed fatty acid carbana wax as a release agent A toner containing an oxidized rice wax having an acid value of 10 to 30 has been disclosed (see Patent Document 2), but has not yet achieved both offset resistance and blocking resistance.
Further, as a toner resin excellent in offset resistance and blocking resistance in a wide fixing temperature range, a copolymer containing styrene, methyl methacrylate, n-butyl acrylate as a monomer, and p-toluenesulfonic acid are used. In addition, a toner has been disclosed which has a cross-linking reaction inside the resin at the time of heat-fixing to improve offset resistance (see Patent Document 3). In this case, although the offset resistance is improved, the toner fluidity under high temperature and high humidity is not always at a satisfactory level.
Furthermore, a polymerized toner containing a polyethylene wax having a crystallinity of 80% or more has been proposed (see Patent Document 4), but the blocking resistance is at a level that is not a problem in practical use. It is not always sufficient for application in high speed machines.
At present, there is no toner that solves the above problems.

JP-A-56-16144 JP-A-4-362953 Japanese Patent Laid-Open No. 5-18839 JP-A-6-130723

The present invention provides a toner for developing an electrostatic image that solves the above-mentioned problems in the conventional toner and a method for producing the same.
That is, an object of the present invention is to provide a static heat excellent in toner storage and blocking resistance, particularly in a high temperature and high humidity environment, in a contact heating fixing system, which is excellent in releasability and fixing characteristics, provides good image quality. An object is to provide a toner for developing a charge image and a method for producing the same.
Furthermore, an object of the present invention is to provide an electrostatic image developer and an image forming method using the toner for developing an electrostatic image.

As a result of intensive studies to overcome the problems in the prior art, the present inventors have solved the above problems by means described in (1). It describes below with (2)-(5) which is a preferable embodiment.
(1) An electrostatic charge image developing toner containing a binder resin, a colorant and a release agent, which contains an ethylene-vinyl acetate copolymer and a polyalkylene as the release agent, and the ethylene-vinyl acetate The maximum value of the endothermic peak obtained by differential scanning calorimetry of the copolymer and the polyalkylene is 75 ° C. to 100 ° C., the degree of aggregation after storage for 20 hours at 55 ° C. and 60% humidity of the toner particles, A toner for developing an electrostatic charge image, characterized in that the difference from the degree of aggregation is 10 to 35%;
(2) The ethylene having a degree of crystallinity determined by X-ray diffraction of the ethylene-vinyl acetate copolymer of 25% to 50% and a vinyl acetate content described in JIS K7192 of 5 to 20%. -The electrostatic image developing toner according to (1), wherein the toner contains 0.3 to 5 wt% of vinyl acetate copolymer,
(3) The method for producing a toner for developing an electrostatic charge image according to (1) or (2), wherein a binder resin particle dispersion in which at least 1 μm or less of binder resin particles are dispersed, a colorant dispersion, and a release agent. Mixing with the mold agent dispersion, aggregating the binder resin particles, the colorant and the release agent to form an aggregated particle dispersion, and heating to a temperature equal to or higher than the glass transition point of the binder resin particles. A method for producing a toner for developing an electrostatic charge image, comprising a step of fusing and coalescing to form toner particles,
(4) An electrostatic charge image developer containing a carrier and a toner, wherein the toner is the electrostatic charge image developing toner according to (1) or (2),
(5) an electrostatic charge image forming step of forming an electrostatic charge image on the electrostatic charge image carrier, a developing step of developing the electrostatic charge image with a developer on the developer carrier to form a toner image, and the toner An image forming method including a transfer step of transferring an image onto a transfer target, wherein the developer is the electrostatic charge image developing toner according to (1) or (2) or the electrostatic charge image according to (4). An image forming method, which is a developer.

  According to the present invention, excellent fixability and offset resistance can be obtained, the fixing temperature in a low temperature range is widened, and blocking resistance and storage stability under high temperature and high humidity are improved.

  The electrostatic image developing toner (hereinafter, also simply referred to as “toner”) of the present invention is an electrostatic image developing toner containing at least a binder resin, a colorant, and a release agent, and the release agent. Containing ethylene-vinyl acetate copolymer and polyalkylene, the maximum value of the endothermic peak determined by differential scanning calorimetry of the ethylene-vinyl acetate copolymer and the polyalkylene is 75 ° C to 100 ° C, The difference between the degree of aggregation after storage for 20 hours at a temperature of 55 ° C. and a humidity of 60% of the toner particles is from 10 to 35%.

The toner for developing an electrostatic charge image of the present invention contains at least a binder resin, a colorant and a release agent. Hereinafter, each component will be described in detail.
(Release agent)
The release agent used in the present invention contains an ethylene-vinyl acetate copolymer and a polyalkylene. Another mold release agent can be further contained.
The maximum value of the endothermic peak obtained by differential scanning calorimetry (DCS) of the ethylene-vinyl acetate copolymer and polyalkylene is 75 to 100 ° C, and preferably 78 to 93 ° C. When the maximum value of the endothermic peak is less than 75 ° C., the melt viscosity becomes low, and when the toner is produced by the hetero-aggregation method, the release agent is melted. Damage. Furthermore, since the amount of the surface release agent increases, the blocking resistance of the toner is impaired. On the other hand, when the temperature exceeds 100 ° C., the production stability is improved, but the melt viscosity is increased, and the elution property of the release agent in the toner in the heat fixing is decreased.

  In the present invention, the measurement of the maximum peak by differential scanning calorimetry uses, for example, DSC-7 manufactured by PerkinElmer. For the temperature correction of the detection part of the apparatus, the melting points of indium and zinc are used, and for the heat quantity correction, the heat of fusion of indium is used. 8 mg of sample is weighed in an aluminum pan, an empty pan is set for control, the temperature is raised between 20 ° C. and 180 ° C. at 10 ° C./min, and then rapidly cooled from 180 ° C. to 20 ° C. After erasing, the temperature is increased again at 10 ° C./min, and the maximum peak of the absorbed heat amount curve at that time is obtained.

  In the present invention, the release agent is preferably present as one or more independent dispersed particles encapsulated in the toner particles. That is, the toner preferably has a release agent domain. It can be observed from a transmission electron microscope (TEM) photograph that the release agent has a domain. Specifically, a sample obtained by slicing toner particles with a microtome is prepared, and a cross section of the toner is observed with a transmission electron microscope (TEM) photograph (approximately 5000 times), whereby the release agent has a domain in the toner. You can confirm that

<Ethylene-vinyl acetate copolymer>
The ethylene-vinyl acetate copolymer used in the present invention preferably has a crystallinity determined by X-ray diffraction of 25% to 50%, more preferably 30 to 45%. When the crystallinity of the ethylene-vinyl acetate copolymer is within the above range, the toner has good fluidity under high temperature and high humidity and is excellent in blocking resistance. Further, it is preferable because the releasability at the time of toner fixing is good and no offset occurs even at high temperature fixing.

The crystallinity of the ethylene-vinyl acetate copolymer is measured by the X-ray diffraction method with an X-ray diffractometer (MXP21 manufactured by Mac Science) under the following conditions.
X-ray: Cu-Kα ray (single color with graphite monochromator)
Wavelength λ = 1.54 Å Output 35 kV, 35 mA
Optical system: reflection method, slit DS, SS = 1 °, RS = 0.3 mm
Measurement range: 2θ = 5 ° -35 °
Step interval: 0.02 ° S
Scanning speed: 2θ / θ continuous scan 1.00 ° / min

  Measurement is performed under the above conditions, and the X-ray diffraction profile of the sample is separated into a crystal peak and amorphous scattering, and is calculated from the area by the following equation.

Crystallinity (%) = Ic / (Ic + Ia) × 100
Ic: Sum of each crystal peak area Ia: Sum of amorphous scattering area

The vinyl acetate content described in JIS K7192 in the ethylene-vinyl acetate copolymer is preferably 5 to 20%, and more preferably 10 to 20%. Within the above range, the fluidity is good even in a high-temperature and high-humidity environment, and an offset does not occur.
In the present invention, the vinyl acetate content is measured by “saponification and potentiometric titration” which is a standard test method defined in JIS K7192, or “acid titration method” which is a control test method.

  Further, the content of the ethylene-vinyl acetate copolymer in the toner is preferably in the range of 0.3 to 5% by weight, and more preferably 0.5 to 4% by weight. Within the above range, the toner has good fluidity under high temperature and high humidity, which is preferable.

  Examples of the ethylene-vinyl acetate copolymer include Luwax EVA3 (manufactured by BASF), Ultrasen 0A52A (manufactured by Tosoh Corporation), EVAFLEX P-1907 (manufactured by Mitsui DuPont Chemical Co., Ltd.), and the like.

The number average molecular weight of the ethylene-vinyl acetate copolymer used as a release agent in the present invention is preferably from 500 to 5,000, more preferably from 1,000 to 4,000.
It is preferable that the molecular weight is within the above-mentioned range since both the storage stability of the toner and the suppression of offset generation at high temperature fixing can be achieved.

<Polyalkylene>
Examples of the polyalkylene that can be used as a release agent in the present invention include paraffin wax, microcrystalline wax, microcrystalline wax, Fischer-Tropsch wax, etc. whose maximum value of endothermic peak obtained by differential scanning calorimetry is 75 to 100 ° C. And minerals such as the above, petroleum-based waxes, and modified products thereof.

  The ethylene-vinyl acetate copolymer does not have releasability by itself because the ethylene part having releasability and the highly polar vinyl acetate part coexist, but when used simultaneously with polyalkylene The ethylene part is compatible with the polyalkylene, and the vinyl acetate part is easily compatible with the binder resin. As a result, the release agent can be arranged in an appropriate size in the toner. Therefore, it is presumed that the characteristics of the toner powder can be maintained.

These release agents are dispersed in water together with ionic surfactants, polymer electrolytes such as polymer acids and polymer bases, and heated with a homogenizer or pressure discharge type disperser that can be heated to the melting point or higher and subjected to strong shearing. A dispersion liquid of particles having an average volume particle diameter D ₅₀ of 1 μm or less is prepared and used.
The average volume particle diameter D ₅₀ size of the resulting release agent particle dispersion liquid, for example, a laser diffraction particle size distribution measuring device: is measured by (LA-700 manufactured by Horiba, Ltd.).

(Binder resin)
The polymer used in the binder resin and binder resin particles used in the present invention is not particularly limited, and examples thereof include vinyl resins, and styrenes such as styrene, parachlorostyrene, and α-methylstyrene, Methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, methacrylic acid (Meth) acrylic acid esters having a vinyl group such as 2-ethylhexyl, vinyl nitriles such as acrylonitrile and methacrylonitrile, vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether, vinyl methyl ketone, vinyl ethyl ketone and vinyl iso Propenylke Vinyl ketones such as emissions, ethylene, propylene, monomers such as polyolefins such as butadiene, beta CEA (beta-carboxyethyl acrylate) may be used polymers such as.

  Further, for example, acrylic acid esters such as pentanediol diacrylate, hexanediol diacrylate, decanediol diacrylate, and nonanediol diacrylate can be used as the crosslinking component. In addition, polymers such as these monomers, copolymers obtained by combining two or more of these, or mixtures thereof, as well as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyethers Examples thereof include a resin, a non-vinyl condensation resin, a mixture of these with the vinyl resin, and a graft polymer obtained when a vinyl monomer is polymerized in the presence of these.

  When an ethylenically unsaturated monomer is used, a binder resin particle dispersion can be prepared by carrying out emulsion polymerization using an ionic surfactant or the like. In the case of other resins, if they are oily and can be dissolved in a solvent with a relatively low solubility in water, the resin is dissolved in those solvents and dispersed in water together with an ionic surfactant or polymer electrolyte, such as a homogenizer. The binder resin particle dispersion can be prepared by dispersing the particles in water using a machine and then heating or reducing the pressure to evaporate the solvent.

The number average molecular weight of the binder resin is preferably 10,000 to 300,000, and more preferably 20,000 to 100,000.
When the molecular weight is within the above range, it is preferable because the powder characteristics of the toner at normal temperature can be kept good and offset of the fixed image can be prevented at high temperature fixing.

The glass transition point of the binder resin is preferably 45 to 65 ° C, and more preferably 50 to 65 ° C.
When the glass transition point is within the above range, it is preferable because deterioration of the powder characteristics due to the release agent can be prevented, and bleeding of the release agent during fixing can be facilitated.

(Coloring agent)
In the present invention, known colorants can be used. For example, examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite.
Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, and permanent yellow NCG. Is given.
Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, benzidine orange G, indanthrene brilliant orange RK, indanthrene brilliant orange GK and the like.
Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watch young red, permanent red 4R, risor red, brilliantamine 3B, brilliantamine 6B, dapon oil red, pyrazolone red, rhodamine B rake, lake red C Rose Bengal, Eoxin Red, Alizarin Lake and the like.

Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, induslen blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate.
Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.
Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.
Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.
Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.
Examples of the dye include various dyes such as basic, acidic, dispersed, and direct dyes, such as nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

  Moreover, these can be used individually or in mixture, and also in the state of a solid solution. These colorants are dispersed by a known method, and for example, a rotary shear type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high-pressure opposed collision type dispersing machine, or the like is preferably used. Further, these colorants are dispersed in an aqueous system by the homogenizer using a polar surfactant.

The colorant is preferably added in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of the binder resin, and the volume average particle diameter D ₅₀ is preferably dispersed to ₅₀ to 250 nm. Further, it is preferable that the toner for developing an electrostatic charge image is contained in the range of 3 to 10% by weight because not only the color developability but also the OHP permeability is excellent. It is preferable that the volume average particle diameter D ₅₀ is in the above range since the ratio of the surface area to the colorant volume is appropriate and is well dispersed. As a result, the storage stability of the colorant dispersion is improved, and abnormal aggregation does not occur due to a shock when mixed with other raw materials at the time of toner production. Furthermore, it is preferable because the transparency and color developability of the toner are improved.

The volume average particle size D ₅₀ can be measured with a Doppler scattering type particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., Microtrac UPA 9340) or a laser diffraction type particle size distribution measuring device (manufactured by Horiba, Ltd., LA-700). .

(Static image developing toner)
In the present invention, the toner particles have a difference between the aggregation degree after storage for 20 hours at a temperature of 55 ° C. and a humidity of 60% and a normal temperature aggregation degree of 10 to 35%. It is preferably 10 to 30%, and more preferably 10 to 25%.
If the difference between the degree of aggregation after storage for 20 hours at 55 ° C. and 60% humidity is less than 10%, the blocking resistance is improved, but the minimum fixing temperature in the low temperature range is increased, When the difference between the degree of aggregation after storage for 20 hours at 55 ° C. and humidity of 60% exceeds the degree of room temperature aggregation, the toner fluidity in a high-temperature and high-humidity environment deteriorates and blocking resistance is undesirably reduced.

The degree of aggregation is determined by measuring the degree of aggregation after storage for 20 hours at 55 ° C. and 60% humidity, and the degree of room temperature aggregation at 25 ° C. and humidity of 50% RH. Here, the normal temperature aggregation degree is the aggregation degree of toner particles stored at 25 ° C. and a humidity of 50% RH for 20 hours.
Using a powder tester (manufactured by Hosokawa Micron Co., Ltd.), set sieves with openings of 56 μm, 45 μm, and 37 μm on the vibrating table so that they overlap in the order of narrow openings, place 2 g of sample on the set sieve, The input voltage is set to 15 V, the vibration table amplitude is adjusted to be in the range of 70 to 90 μm, and vibration is applied for 90 seconds. Thereafter, the mass of the sample remaining on each sieve was measured and calculated from the following formula.
Cohesion (%) = [W _56/2] × 100 + [W ₄₅ /2〕×100×0.6Tasu〔W ₃₈ /2G〕×100×0.2
(W56 represents the sample mass (g) remaining on the sieve having an aperture of ₅₆ μm, W45 represents the sample mass (g) remaining on the sieve having an aperture of 45 μm, and W38 represents an aperture of 38 μm. Represents the sample mass (g) remaining on the sieve.)

The volume average particle diameter D ₅₀ of the toner in the present invention is preferably 2 to 9 μm, and more preferably 4 to 7 μm. It is preferable that the volume average particle size is in the above range since good chargeability can be obtained and developability is good. Furthermore, it is preferable because the resolution of the image is good.
The particle size distribution index of the toner of the present invention is preferably such that the volume average particle size distribution index GSDv is 1.30 or less, and the ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp is 0. .95 or more is preferable.
It is preferable that the volume distribution index GSDv is 1.30 or less because the resolution is good. Further, it is preferable that the ratio of the volume average particle size distribution index GSDv and the number average particle size distribution index is 0.95 or more because good chargeability is obtained and image loss such as scattering and fogging does not occur.

Here, the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp are obtained as follows. First, the average particle size distribution is, for example, a particle size range divided based on the particle size distribution measured with a measuring instrument such as Coulter Counter Multisizer II (manufactured by Beckman-Coulter) (Division method: 1.26 to 50). The measurement particle size range up to .8 μm was divided into 16 channels so that the logarithmic scale was 0.1 intervals, specifically, channel 1 was 1.26 μm or more and less than 1.59 μm, and channel 2 was 1.59 μm or more. Less than 2.00 μm, channel 3 is greater than or equal to 2.00 μm and less than 2.52 μm, etc. Is divided into 0.3,..., 1.6), and a cumulative distribution is drawn from the small particle size side for each of the volume and the number, and the particle size that becomes 16% cumulative is the volume D. 6v, number D16p, cumulative 50% become volume particle diameter D50v, the number D50p, volume particle size at a cumulative 84% D84v, defined as the number D84p.
The volume particle size distribution index GSDv and the number average particle size distribution index GSDp are given by the following equations.
GSDv = (D84v / D16v) ^1/2
GSDp = (D84p / D16p) ^1/2
The particle size measurement range of this measuring machine is determined by the aperture diameter. For example, in the case of an aperture of 100 μm, it is 2 to 60 μm. In this case, it is needless to say that the calculation is not made for the channel 2 or less which is less than 2 μm.

  The toner for electrophotography of the present invention can be used in any form from an irregular shape to a spherical shape. However, by setting the shape factor SF1 of the toner of the present invention in the range of 105 to 140, the developability and transfer can be improved. The toner for developing an electrostatic image having excellent properties can be provided, which is preferable. A more preferable range of the shape factor SF1 is 110 to 135. The shape factor SF1 is an average value of the shape factors, and is calculated by the following method. That is, an optical microscopic image of toner spread on a slide glass is taken into a Luzex image analyzer through a video camera, and SF1 is obtained from the peripheral length and projected area for 50 or more toners by the following formula, and an average value is obtained. Is.

  In the formula, ML represents the maximum length of toner particles, and A represents the projected area of the particles.

(Surfactant)
Examples of surfactants used in the present invention for emulsion polymerization, colorant dispersion, binder resin particles, release agent dispersion, aggregation, or stabilization thereof include sulfate ester salts, sulfonate salts, and phosphate esters. -Based, soap-based anionic surfactants, amine salt-based, quaternary ammonium salt-based cationic surfactants, polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based nonionic interfaces An active agent is mentioned, and it is also effective to use these together. As a means for dispersion, general means such as a rotary shear type homogenizer, a ball mill having a media, a sand mill, a dyno mill, and the like can be used.

(Method for producing toner for developing electrostatic image)
Hereinafter, the method for producing the toner for developing an electrostatic charge image of the present invention will be described in detail.
The electrostatic image developing toner of the present invention can be produced by any method, but is preferably produced by the following method.
That is, a binder resin particle dispersion in which at least 1 μm or less of binder resin particles are dispersed, a colorant dispersion, and a release agent dispersion are mixed, and the binder resin particles, the colorant, and the release agent are aggregated. A step of forming an agglomerated particle dispersion (hereinafter sometimes referred to as an “aggregation step of the mother agglomerated particles”), fusing and coalescing by heating to a temperature equal to or higher than the glass transition point of the binder resin particles; A method for producing a toner for developing an electrostatic image including a step of forming particles (hereinafter sometimes referred to as a “fusion step”) is preferable.

  Further, between the agglomeration step and the fusion step, a step of adding and mixing a particle dispersion in which particles are dispersed in an agglomerated particle dispersion to adhere the particles to the agglomerated particles to form adhered particles (attachment) Step) can also be provided.

  In the adhering step, the particle dispersion is added to and mixed with the aggregated particle dispersion prepared in the aggregating step, and the particles are adhered to the aggregated particles to form the adhering particles. Since this corresponds to newly added particles as seen from the aggregated particles, it may be referred to as “additional particles” in this specification. As the additional particles, in addition to the binder resin particles, release agent particles, colorant particles and the like may be used alone or in combination. There is no restriction | limiting in particular as a method of adding and mixing a particle dispersion liquid, For example, you may carry out gradually continuously and may carry out in steps divided | segmented into multiple times. In this way, by adding and mixing particles (additional particles), the generation of fine particles can be suppressed, and the particle size distribution of the resulting toner for developing electrostatic images can be sharpened, contributing to higher image quality. To do.

  In addition, by providing an adhesion step, a pseudo shell structure can be formed, and the toner surface exposure of internal additives such as colorants and release agents can be reduced, resulting in improved chargeability and life. Can do. Furthermore, at the time of fusing in the fusing process, the particle size distribution can be maintained and fluctuations thereof can be suppressed, and addition of a surfactant or a stabilizer such as a base or an acid to enhance the stability at the time of fusing becomes unnecessary. It is advantageous in that the amount of addition can be suppressed to the minimum, and the cost can be reduced and the quality can be improved. In particular, in the present invention, since a release agent is used, it is preferable to add additional particles mainly composed of binder resin particles in the attaching step. Furthermore, if this method is used, the toner shape can be easily controlled by adjusting the temperature, the number of stirring, the pH and the like in the fusing step.

The binder resin particles are generally produced by emulsion polymerization or the like.
In the aggregation step of the mother agglomerated particles and / or the attachment step of various particles, the type and amount of the ionic surfactant that adjusts the polarity of the dispersion are selected to control the degree of aggregation and / or adhesion. be able to. For example, by dispersing the binder resin particles in a solution containing an anionic surfactant, dispersing the colorant in a solution containing a cationic surfactant, and mixing both, the binder resin particles and Colorant particles and the like can be aggregated.
Thereafter, the toner is heated to a temperature above the glass transition point of the binder resin to fuse and coalesce the aggregates, and is washed and dried. The toner shape is preferably from irregular to spherical.

  In addition, even if the process is performed by mixing and agglomerating all at once, in the agglomeration step, the initial balance of the amount of the ionic dispersant of each polarity is shifted in advance, for example, an inorganic material such as calcium nitrate. This is ionically neutralized by using a metal salt or a polymer of inorganic metal salt such as polyaluminum chloride to form a first-stage matrix aggregation below the glass transition point, and after stabilization, as a second stage Add a particle dispersion treated with a dispersing agent of polarity and quantity that compensates for the balance deviation, and if necessary, slightly heat below the glass transition point of the binder resin contained in the base or additional particles, After stabilization at a higher temperature, the particles added in the second stage of agglomeration by heating to a temperature above the glass transition point may be combined together while adhering to the surface of the base agglomerated particles. Furthermore, the stepwise operation of aggregation may be repeated several times.

  Aggregation of the mother agglomerated particles may be performed by mixing the binder resin particle dispersion, the colorant particle dispersion, and the release agent particle dispersion having different polarities to form aggregated particles, the binder resin particles, the colorant, In addition, a method of forming aggregated particles by adding a surfactant having a polarity different from that of the dispersion to the dispersion obtained by mixing the release agent with the release agent may be employed.

(Other additives)
In the electrostatic charge image developing toner of the present invention, a charge control agent can be used in order to further improve and stabilize the chargeability. As the charge control agent, various commonly used charge control agents such as quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments can be used. It is preferable to use a material that is difficult to dissolve in water from the viewpoint of controllability of ionic strength that affects the stability at the time of toner formation due to aggregation and melting, and prevention of wastewater contamination.
In the electrostatic image developing toner of the present invention, inorganic particles can be added in a wet manner in order to stabilize the chargeability. Examples of inorganic particles to be added include silica, alumina, titania, calcium carbonate, magnesium carbonate, and tricalcium phosphate, which are usually used as external additives on the toner surface, such as ionic surfactants, polymer acids, and high It can be used after being dispersed with a molecular base or the like.
In addition, for the purpose of imparting toner fluidity and improving cleaning properties, after the toner drying step, as in normal toners, inorganic particles such as silica, alumina, titania, calcium carbonate, vinyl resin, polyester, silicone, etc. The resin particles can also be added to the toner surface by applying a shearing force in a dry state.

  After completion of the aggregation and fusion, a desired toner is obtained through an arbitrary washing step, solid-liquid separation step, and drying step. In the washing step, it is preferable to sufficiently perform substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

(Static charge image developer)
Next, the electrostatic charge image developer of the present invention will be described.
The electrostatic image developer of the present invention contains the toner for developing an electrostatic image of the present invention, and other components can be blended depending on the purpose. The electrostatic image developer of the present invention can be used as a one-component electrostatic image developer using the electrostatic image developing toner of the present invention alone, but is a two-component electrostatic image developer used in combination with a carrier. It is preferably used as a charge image developer. There are no particular limitations on the carrier, and examples include known carriers. For example, known carriers such as resin-coated carriers described in JP-A Nos. 62-39879 and 56-11461 can be used. Can be used.

<Career>
Examples of the core particles of the resin-coated carrier include moldings such as iron powder, ferrite, and magnetite, and the average diameter is about 30 to 200 μm. Examples of the coating resin include styrenes such as styrene, parachlorostyrene, and α-methylstyrene, methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, Α-methylene fatty acid monocarboxylic acids such as n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate, nitrogen-containing acrylics such as dimethylaminoethyl methacrylate, vinyl nitriles such as acrylonitrile and methacrylonitrile, 2-vinyl Vinyl pyridines such as pyridine and 4-vinyl pyridine, vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; Homopolymers such as olefins such as tylene and propylene, vinyl-type fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene, or copolymers comprising two or more monomers, methyl silicone, methylphenyl silicone And the like, polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like. These resins may be used alone or in combination of two or more.

  The amount of the coating resin is preferably in the range of 0.1 to 10 parts by weight and more preferably in the range of 0.5 to 3.0 parts by weight with respect to 100 parts by weight of the core particles. For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used. The mixing ratio of the toner and the carrier in the electrostatic image developer is not particularly limited, and can be appropriately selected according to the purpose.

(Image forming method)
The image forming method of the present invention will be described in detail below. An electrostatic charge image forming step of forming an electrostatic charge image on the electrostatic charge image bearing member; a developing step of developing the electrostatic charge image with a developer on the developer bearing member to form a toner image; An image forming method including a transfer step of transferring onto a transfer body, wherein the developer for developing an electrostatic charge image of the present invention or an electrostatic charge image developer using the same is used as the developer.

  The electrostatic charge image forming step includes a charging step for charging the photosensitive member and an exposure step for exposing the charged photosensitive member to produce an electrostatic charge image on the photosensitive member. Specifically, the surface of the photoreceptor, which is an electrostatic charge image carrier, is uniformly charged by a charging means, and then exposed to the electrostatic charge image carrier with a laser optical system or LED array to form an electrostatic charge image. It is a process to do. As the charging means, the surface of the electrostatic charge image carrier is charged by applying a voltage to a non-contact type charger such as corotron or scorotron and a conductive member in contact with the surface of the electrostatic charge image carrier. A contact-type charger may be mentioned, and any type of charger may be used. However, a contact charging type charger is preferable from the viewpoint that the amount of ozone generated is small and the effect of excellent printing durability is exhibited. In the contact charging type charger, the shape of the conductive member may be any of a brush shape, a blade shape, a pin electrode shape, a roller shape, and the like, but a roller-like member is preferable. The image forming method of the present invention is not subject to any particular limitation in the electrostatic charge image forming process.

  The developing step refers to an electrostatic charge image on the surface of the electrostatic charge image carrier by bringing a developer carrier having a developer layer containing at least toner on the surface thereof into contact with or close to the surface of the electrostatic charge image carrier. In this step, toner particles are attached to form a toner image (development image) on the surface of the electrostatic image carrier. The development method can be performed using a known method, but examples of the development method using a two-component developer include a cascade method and a magnetic brush method. The image forming method of the present invention is not particularly limited with respect to the developing method.

  The transfer step is a step of transferring a toner image formed on the surface of the electrostatic charge image carrier to form a transfer image. As a transfer device for transferring a toner image from an electrostatic charge image carrier onto paper or the like, a conventional corotron or scorotron transfer can be used, but a conductive bias transfer roll made of an elastic material with less generation of ozone or the like is used. A method is mentioned. As a transfer roll, a metal roll whose surface is covered with a rubber layer and this surface rubber layer is fluorine treated is often used. Further, in order to effectively avoid the situation where residual toner or the like adheres to this type of transfer roll, a cleaning device is provided in which a cleaning blade is placed in contact with the transfer roll. Here, as the cleaning blade, for example, an elastic body such as urethane rubber is used so as not to damage the fluorine-treated film that is the surface coating layer of the transfer roll. However, the transfer blade member and the roll cleaning means are particularly limited. It is not a thing. In transferring, it is also preferable to perform contact transfer in which the bias transfer roll is brought into pressure contact with the electrostatic charge image carrier with a linear pressure of 5 g / cm or more to transfer the toner image onto the paper.

The image forming method of the present invention preferably further includes a fixing step after the transfer step.
The fixing step is a step of fixing the toner image transferred to the surface of the recording medium with a fixing device. As the fixing device, a heat fixing device using a heat roll is preferably used. The heat fixing device includes a heater roller for heating inside a cylindrical metal core, a fixing roller in which a so-called release layer is formed by a heat resistant resin coating layer or a heat resistant rubber coating layer on the outer peripheral surface thereof, and the fixing roller. The pressure roller or the pressure belt is disposed in pressure contact with the roller and has a heat-resistant elastic layer formed on the outer peripheral surface of the cylindrical metal core or the surface of the belt-like base material. The fixing process of the unfixed toner image is performed by inserting a recording medium on which an unfixed toner image is formed between a fixing roller and a pressure roller or a pressure belt, so that a binder resin, an additive, etc. Fix by heat melting. In the image forming method of the present invention, the fixing method is not particularly limited.

  In the image forming method of the present invention, when a full-color image is produced, each of the plurality of electrostatic charge image carriers has a developer carrier for each color, and the plurality of electrostatic image carriers and development. Each color toner image for each step is sequentially laminated on the same recording medium surface by a series of steps consisting of an electrostatic charge image forming step, a developing step, and a transfer step by each agent carrier, and the full color toner thus laminated An image forming method in which an image is thermally fixed in a fixing step is preferably used. Then, by using the electrostatic image developing toner or electrostatic image developer of the present invention in the above image forming method, for example, even in a tandem system suitable for downsizing and color speeding, stable development, transfer, Fixing performance can be obtained.

  Examples of the recording material to which the toner image is transferred include plain paper, OHP sheet, and the like used for electrophotographic copying machines and printers. In order to further improve the smoothness of the image surface after fixing, the surface of the recording medium is preferably as smooth as possible. For example, coated paper in which the surface of plain paper is coated with a resin or the like, art paper for printing Etc. can be used suitably.

  According to the image forming method of the present invention, it is possible to obtain a high-quality image over a long period of time without causing image quality defects such as image unevenness and high transfer efficiency.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

(Preparation of binder resin particle dispersion)
Styrene (manufactured by Wako Pure Chemical Industries, Ltd.) 325 parts by weight n-butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 75 parts by weight β-carboxyethyl acrylate (manufactured by Rhodia Nikka) 9 parts by weight 1,10 decanediol Diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) 1.5 parts by weight dodecanethiol (manufactured by Wako Pure Chemical Industries, Ltd.) 2.7 parts by weight Ion-exchanged water 50 in which 6 parts by weight of ammonium persulfate was dissolved while being slowly stirred and mixed for 10 minutes with 4 parts by weight dissolved in 550 parts by weight of ion-exchanged water in a flask. Part by weight was added.
Then, after sufficiently replacing the nitrogen in the system, the flask was heated with an oil bath while stirring until the system reached 70 ° C., and emulsion polymerization was continued for 5 hours.
As a result, a binder resin particle dispersion having a volume average particle size of 195 nm, a solid content of 42%, a glass transition point of 51.5 ° C., and a Mw of 31,000 was obtained.

(Preparation of mold release agent dispersion 1)
38 parts by weight of paraffin HNP0085 (mp 85 ° C., viscosity 2.3 mPas (180 ° C.): manufactured by Nippon Seiwa Co., Ltd.)
7 parts by weight of ethylene-vinyl acetate copolymer Luwax EVA3 (vinyl acetate content 14%, melting point 93 ° C., crystallinity 33%: manufactured by BASF)
Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by weight Ion-exchanged water 200 parts by weight The above is heated to 95 ° C. and sufficiently dispersed with IKA Ultra Turrax T50, followed by pressure discharge A release agent dispersion 1 having a volume average particle size of 205 nm and a solid content of 25.1% was obtained by dispersing with a type gorin homogenizer.

(Preparation of release agent dispersion 2)
Dispersing the mold release agent, except for using Ultrasen 0A52A (vinyl acetate content 8%, melting point 97 ° C., crystallinity 42%: manufactured by Tosoh Corporation) instead of the ethylene-vinyl acetate copolymer Luwax EVA3 The same procedure as in Preparation 1 was performed to obtain a release agent dispersion 2 having a volume average particle size of 208 nm and a solid content of 25%.

(Preparation of release agent dispersion 3)
Mold release agent, except that EVAFLEX P-1907 (vinyl acetate content 19%, melting point 84 ° C., crystallinity 26%, manufactured by Mitsui DuPont Chemical Co., Ltd.) was used in place of the ethylene-vinyl acetate copolymer Luwax EVA3. By operating in the same manner as in Preparation 1 of the dispersion, a wax dispersion having a volume average particle size of 203 nm and a solid content of 25% was obtained.

(Preparation of colorant dispersion 1)
Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika Kogyo Co., Ltd.) 40 parts by weight nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Industries, Ltd.) 5 parts by weight of ion-exchanged water 200 parts by weight of the above components Were mixed and dissolved, and dispersed for 10 minutes with a homogenizer (manufactured by IKA, Ultra Tarrax) to obtain a colorant dispersion 1 having a volume average particle size of 168 nm.

(Preparation of colorant dispersion 2)
Yellow pigment (PY74: manufactured by Clariant) 40 parts by weight nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Industries, Ltd.) 5 parts by weight ion-exchanged water 200 parts by weight The above components are mixed and dissolved, and homogenizer (IKA, Ultra Turrax) was dispersed for 10 minutes to obtain a colorant dispersion 2 having a volume average particle size of 148 nm.

(Preparation of colorant dispersion 3)
Magenta pigment (R122: manufactured by Dainichi Seika Kogyo Co., Ltd.) 40 parts by weight nonionic surfactant (Nonipol 400: manufactured by Sanyo Kasei Kogyo Co., Ltd.) 5 parts by weight ion-exchanged water 200 parts by weight It melt | dissolved and disperse | distributed for 10 minutes with the homogenizer (the product made by IKA, ultra turrax), and the colorant dispersion liquid 3 with a volume average particle diameter of 176 nm was obtained.

(Production Example 1 of toner for developing electrostatic image)
Binder resin particle dispersion 80 parts by weight Colorant dispersion 1 40 parts by weight Inorganic particle A dispersion 6.5 parts by weight (manufactured by Nissan Chemical Industries, Ltd., ST-OS; volume average particle diameter = 8 nm)
Inorganic particle B dispersion 6.5 parts by weight (manufactured by Nissan Chemical Industries, Ltd., ST-OL; volume average particle size = 4 nm)
Release agent dispersion 1 40 parts by weight
(Ethylene-vinyl acetate copolymer content 16%)
Polyaluminum chloride 0.41 parts by weight

After thoroughly mixing and dispersing 173.43 parts by weight of the above components in a round stainless steel flask with a homogenizer (manufactured by IKA, Ultra Tarrax T50), the flask was heated to 47 ° C. with stirring in an oil bath for heating. The aggregated particle dispersion was prepared by holding at 47 ° C. for 60 minutes. To this aggregated particle dispersion, 31 parts by weight of the above binder resin particle dispersion was gently added.
Thereafter, 0.5 mol / liter sodium hydroxide aqueous solution was added to adjust the pH in the system to 5.4, and then the flask was sealed and heated to 96 ° C. while continuing stirring using a magnetic seal. For 5 hours. After completion of the reaction, the mixture was cooled, filtered, thoroughly washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 3 liters of ion-exchanged water at 40 ° C. and stirred for 15 minutes at 300 rpm for washing. This was repeated five more times, and when the pH of the filtrate was 7.01, the electric conductivity was 9.8 μS / cm, and the surface tension was 71.1 Nm, No. 3 was obtained by Nutsche suction filtration. Solid-liquid separation was performed using 5A filter paper, and then vacuum drying was continued for 12 hours to obtain toner particles 1.

When the particle diameter of the toner particles 1 was measured with a Coulter counter, the volume average particle diameter D ₅₀ was 5.6 μm, and the volume average particle size distribution index GSDv was 1.21. Further, the shape factor SF1 obtained from the shape observation by Luzex was 118.0 and spherical, and the content of the ethylene-vinyl acetate copolymer contained in the toner was 2.5%.
Further, the difference between the aggregation degree after storage for 20 hours at a temperature of 55 ° C. and a humidity of 50% of the obtained toner particles 1 was 14%.

(Production Example 2 of toner for developing electrostatic image)
Except for using the colorant dispersion 2 in place of the colorant dispersion 1 and using the release agent dispersion 2 in place of the release agent dispersion 1, the same as in Production Example 1 of the electrostatic charge image developing toner Thus, toner particles 2 were obtained.
When the particle size of the toner particles 2 was measured with a Coulter counter, the volume average particle size D ₅₀ was 5.7 μm, and the volume average particle size distribution index GSDv was 1.22. Further, the shape factor SF1 obtained from the shape observation by Luzex was 117.0 and spherical, and the content of the ethylene-vinyl acetate copolymer contained in the toner was 2.2%.
Further, the difference between the aggregation degree after storage for 20 hours at a temperature of 55 ° C. and a humidity of 50% of the obtained toner particles 2 was 16%.

(Production Example 3 of toner for developing electrostatic image)
Except for using the colorant dispersion 3 instead of the colorant dispersion 1, and using the release agent dispersion 3 instead of the release agent dispersion 1, the same as in Production Example 1 of the electrostatic charge image developing toner In this way, toner particles 3 were obtained.
When the particle size of the toner particles 3 was measured with a Coulter counter, the volume average particle size D ₅₀ was 5.65 μm, and the volume average particle size distribution index GSDv was 1.22. Further, the shape factor SF1 obtained from the shape observation by Luzex was 119.0 and spherical, and the content of the ethylene-vinyl acetate copolymer contained in the toner was 2.8%.
In addition, the difference between the aggregation degree after storage for 20 hours at a temperature of 55 ° C. and a humidity of 50% of the obtained toner particles 3 was 15%.

(Comparative Preparation Example 1 of Release Agent Dispersion)
45 parts by weight of paraffin HNP085 (mp 85 ° C., viscosity 2.3 mPas (180 ° C.): manufactured by Nippon Seiwa Co., Ltd.)
Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by weight ion-exchanged water 200 parts by weight The above was heated to 95 ° C. and sufficiently dispersed with IKA Ultra Turrax T50, then pressure Dispersion treatment was performed with a discharge type gorin homogenizer to obtain a release agent dispersion 4 having a volume average particle size of 200 nm and a solid content of 25.0%.

(Production Example 4 of toner for developing electrostatic image)
Toner particles 4 were obtained in the same manner as in Production Example 1 of toner for developing an electrostatic charge image except that the release agent dispersion 4 was used instead of the release agent dispersion 1.
When the particle diameter of the toner particles 4 was measured with a Coulter counter, the volume average particle diameter D ₅₀ was 5.72 μm, and the volume average particle size distribution index GSDv was 1.23. Further, the shape factor SF1 obtained from the shape observation by Luzex was 118.0 and was spherical.
Further, the difference between the aggregation degree after storage for 20 hours at a temperature of 55 ° C. and a humidity of 50% of the obtained toner particles 4 was 48%.

(Production Examples 1 to 4 of electrostatic image developer)
1.5 parts by weight of hydrophobic silica (TS720: manufactured by Cabot) was added to 1 to 4 parts by weight of the toner particles 1 to 4, and blended by a sample mill to obtain externally added toners 1 to 4. Further, a coated carrier in which a ferrite core having a volume average particle diameter of 50 μm was coated with 1% of polymethyl methacrylate resin (manufactured by Soken Chemical Co., Ltd., Mw: 75,000) was obtained. Then, the externally added toner and the coat carrier were weighed so that the concentration of the externally added toner was 5%, and stirred and mixed with a ball mill for 5 minutes to obtain developers 1 to 4.

(Examples 1-3)
The fixability of the produced developers 1 to 3 was adjusted to a toner applied amount of 14.0 g / m ² using a modified DocuCenter Color 400 (manufactured by Fuji Xerox Co., Ltd.), and an unfixed image was printed. Was fixed at a fixing speed of 180 mm / sec under Nip 6.5 mm.
The fixing device had good peelability, and it was confirmed that the fixing device was peeled without any resistance, and the occurrence of offset was not confirmed up to a temperature of 220 ° C. Also, no image defect was observed when the fixed image was folded in two and stretched again.

  Further, 30 g of toner was taken in a 100 ml beaker, and left for 10 days in a constant temperature and humidity room where the temperature and humidity were controlled at 50 ° C. and a humidity of 50%. When blocking resistance was confirmed, slight aggregation was observed. Although it did not stick, the fluidity was recovered immediately and good blocking resistance was exhibited.

(Comparative Example 1)
The fixability of developer 4 was evaluated in the same manner as in Examples 1 to 3.
The fixing device had good peelability, but offset slightly occurred at 210 ° C., and 30 g of toner was taken in a 100 ml beaker, and the temperature and humidity were controlled at 50 ° C. and 50% humidity in a constant temperature and humidity room. When the blocking resistance was confirmed by standing for 10 days, aggregation was observed on the upper surface, and even when the beaker was shaken strongly, the aggregation was in a state that was not easily loosened.

Claims (5)

An electrostatic charge image developing toner containing a binder resin, a colorant and a release agent,
Containing an ethylene-vinyl acetate copolymer and a polyalkylene as the release agent,
The maximum value of the endothermic peak determined by differential scanning calorimetry of the ethylene-vinyl acetate copolymer and the polyalkylene is 75 ° C to 100 ° C,
A toner for developing an electrostatic charge image, characterized in that a difference between an aggregation degree after storage for 20 hours at a temperature of 55 ° C. and a humidity of 60% of the toner particles is 10 to 35%. The ethylene-vinyl acetate copolymer having a crystallinity determined by X-ray diffraction of 25% to 50% and a vinyl acetate content described in JIS K7192 of 5 to 20%. The electrostatic image developing toner according to claim 1, wherein the toner contains 0.3 to 5 wt% of a copolymer. A method for producing an electrostatic charge image developing toner according to claim 1, wherein
A binder resin particle dispersion in which at least 1 μm or less of binder resin particles are dispersed, a colorant dispersion, and a release agent dispersion are mixed, and the binder resin particles, the colorant, and the release agent are aggregated to form aggregated particles. Forming a dispersion; and
A method for producing a toner for developing an electrostatic charge image, comprising a step of heating and fusing and coalescing to a temperature equal to or higher than a glass transition point of the binder resin particles to form toner particles. An electrostatic charge image developer containing a carrier and a toner,
The electrostatic image developer according to claim 1, wherein the toner is the electrostatic image developing toner according to claim 1. An electrostatic charge image forming step of forming an electrostatic charge image on the electrostatic charge image carrier,
An image forming method comprising: a developing step of developing the electrostatic image with a developer on a developer carrying member to form a toner image; and a transferring step of transferring the toner image onto a transfer target,
An image forming method, wherein the developer is the electrostatic image developing toner according to claim 1 or 2 or the electrostatic image developer according to claim 4.