JP5866791B2 - Toner for developing electrostatic image and method for producing the same, developer for electrostatic image, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic image and a method for producing the same, an electrostatic image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

  In recent years, image forming apparatuses such as printers and copiers have been widely used, and technologies relating to various elements constituting the image forming apparatus have also been widely used. Among image forming apparatuses that employ an electrophotographic system, a photosensitive member (image holding member) is charged using a charging device, and the electrostatic potential on the charged photosensitive member is different from the surrounding potential. A pattern to be printed is often formed by forming a latent image, and the electrostatic latent image formed in this way is developed with toner, and finally is formed on a recording medium such as recording paper. Transcribed.

  For example, Patent Document 1 states that “a step of forming resin fine particles by a wet method, at least the resin fine particles and the colorant fine particles are aggregated in an aqueous medium or after being aggregated, and then fixed by heating to form core particles. And an electrostatic latent image developing toner produced by a method including a step of forming a shell layer on the surface of a core particle by interfacial polymerization.

  Patent Document 2 states that “a step of mixing and aggregating a colorant dispersion and a latex solution to form a core of toner particles, a monomer after adding a polymerization initiator to the core, And a step of polymerizing the monomer on the surface of the core to form a shell on the core.

  Patent Document 3 states that “at least one unsaturated polyester resin is composed of carboxylic acid, carboxylic anhydride, styrene, α-methylstyrene, alkyl ester of acrylic acid, alkyl ester of methacrylic acid, and combinations thereof. Contacting with at least one graft monomer selected from the group and polymerizing the graft monomer and the unsaturated polyester resin to provide an acid number of from about 10 milligram equivalents to about 1000 milligram equivalents of potassium hydroxide per gram of resin. Forming a graft copolymer, and contacting the graft copolymer with an optional colorant, at least one surfactant, and an optional wax to form small particles in the dispersion; Agglomerating and fusing the agglomerated small particles to form toner particles; Recovered, the process characterized in that it comprises a step. "Has been proposed.

  Further, Patent Document 4 states that “in a toner production method including a step of suspending fine particles containing a resin and a colorant in water, using this as a core particle, and adsorbing a vinyl resin monomer to grow the core particle. In addition, the vinyl resin monomer has hydrophilicity equivalent to and / or equal to or higher than the resin contained in the core particle, and the Tg when the vinyl resin monomer is polymerized is greater than the Tg of the resin in the core particle. A method for producing a toner characterized by being high is proposed.

  Patent Document 5 states that “in a toner composition containing a binder resin and a colorant, the binder resin has a durometer D hardness of 20 or more at room temperature, a melting point of 40 to 120 ° C.,” And a toner composition comprising a crystalline resin having a rubber-like region in the range of melt viscosity of 102 to 106 Pa · s as a main component, and toner particles having a surface layer ”,“ surface layer , "Toner composition formed by emulsion graft polymerization", "Toner composition in which surface layer is chemically modified. Toner in which surface layer is chemically modified and polar group is introduced" Has been.

  Patent Document 6 discloses, in claim 1, “an electrophotographic toner comprising at least a binder resin having an unsaturated double bond, a reactive monomer, and a radical polymerization catalyst”. Item 5 states that “the toner particles containing at least a binder resin having an unsaturated double bond, a reactive monomer, and a radical polymerization catalyst are subjected to heat treatment or a mechanical impact force toward the surface of the toner particles. And a method of producing a toner for electrophotography, wherein the toner is cured so as to increase the crosslinking density in a stepwise manner, and “to the surface of toner particles containing a binder resin having at least an unsaturated double bond”. After the reactive monomer and the radical polymerization catalyst are attached, it is cured by applying a heat treatment or mechanical impact force so as to gradually increase the crosslinking density toward the surface of the toner particles. Method for producing a toner for electrophotography according to claim 5, wherein. "Is proposed.

  Patent Document 7 states that “manufacturing a toner having a step of polymerizing a polymerizable monomer in the presence of a base particle containing a binder resin to enlarge and / or modify the surface of the base particle. In the method, a method for producing a toner is proposed in which a polymerization initiator having a hydrophilic part, a hydrophobic part, and a reactive part in the molecule is used in the polymerization. Yes.

JP 2004-294839 A Japanese Patent Application Laid-Open No. 2006-119652 JP 2010-26515 A Japanese Patent Laid-Open No. 61-118758 Japanese Patent Laid-Open No. 9-218535 JP-A-8-30026 JP 2003-43747 A

  An object of the present invention is to provide a toner for developing an electrostatic image that realizes low-temperature fixability.

The above problem is solved by the following means. That is,
The invention according to claim 1
A crystalline polyester resin and an amorphous polyester resin having an unsaturated polyester component, wherein the surface layer portion includes a cross-linked product of the unsaturated polyester component and a vinyl monomer, and the inside is the crystalline polyester. 15. A resin and an amorphous polyester resin having an unsaturated polyester component are included, the composition does not contain the crosslinked product, and the tetrahydrofuran (THF) insoluble content derived from the crosslinked product exceeds 2.0% by mass. An electrostatic image developing toner having toner particles of 0% by mass or less.

The invention according to claim 2
2. The electrostatic image developing toner according to claim 1, wherein the unsaturated polyester component is a component derived from at least one polycarboxylic acid selected from fumaric acid, maleic acid, and maleic anhydride.

The invention according to claim 3
The electrostatic charge image developing toner according to claim 1, wherein the vinyl monomer is at least one selected from styrene monomers, acrylic acid esters, and methacrylic acid esters.

The invention according to claim 4
An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1.

The invention according to claim 5
Containing the toner for developing an electrostatic charge image according to any one of claims 1 to 3,
A toner cartridge to be attached to and detached from the image forming apparatus.

The invention according to claim 6
A developing means for accommodating the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus.

The invention according to claim 7 provides:
An image carrier,
Charging means for charging the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic image developer according to claim 4 and developing the electrostatic image formed on the image carrier as a toner image by the electrostatic image developer;
Transfer means for transferring a toner image formed on the image carrier onto a transfer target;
Fixing means for fixing the toner image transferred onto the transfer medium;
Image forming apparatus comprising

The invention according to claim 8 provides:
A charging step for charging the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing the electrostatic image formed on the image carrier as a toner image with the electrostatic image developer according to claim 4;
A transfer step of transferring a toner image formed on the image carrier onto a transfer target;
A fixing step of fixing the toner image transferred onto the transfer medium;
An image forming method comprising:

The invention according to claim 9 is:
Preparing at least a polyester resin particle dispersion in which crystalline polyester resin particles and amorphous polyester resin particles having an unsaturated polyester component are dispersed, at least the crystalline polyester resin particles and the amorphous polyester resin A step of agglomerating the particles to form first agglomerated particles;
A first aggregated particle dispersion in which the first aggregated particles are dispersed and a polyester resin particle dispersion in which amorphous polyester resin particles having an unsaturated polyester component are dispersed are mixed, and the first aggregated particles are mixed. A step of aggregating the amorphous polyester resin particles on the surface thereof to form second agglomerated particles,
Heating the second aggregated particle dispersion in which the second aggregated particles are dispersed, fusing and coalescing the second aggregated particles to form toner particles;
A vinyl monomer and a polymerization initiator are added to the toner particle dispersion in which the toner particles are dispersed, and the unsaturated polyester component of the amorphous polyester resin and the vinyl present in the surface layer portion of the toner particles. Cross-linking with a monomer, and forming a cross-linked product by the cross-linking on the surface layer of the toner particles;
The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 3 .

According to the first aspect of the present invention, the unsaturated polyester component and the vinyl monomer are formed on the surface layer portion of the toner particle including the crystalline polyester resin and the amorphous polyester resin having the unsaturated polyester component. The toner for developing an electrostatic image that realizes low-temperature fixability can be provided as compared with the case where no crosslinked product is contained and the THF-insoluble content is outside the above range.
According to the invention of claim 2, the unsaturated polyester component of the amorphous polyester resin is a component derived from a dicarboxylic acid other than selected from fumaric acid, maleic acid, and maleic anhydride. An electrostatic charge image developing toner that achieves low-temperature fixability can be provided.
According to the invention according to claim 3, compared with the case where the vinyl monomer is a vinyl monomer other than a styrene monomer, an acrylic acid ester, and a methacrylic acid ester, An electrostatic charge image developing toner that achieves low-temperature fixability can be provided.

  According to the inventions according to claims 4, 5, 6, 7, and 8, the electrostatic charge in which the surface layer portion of the toner particles does not contain a cross-linked product of the unsaturated polyester component of the amorphous polyester resin and the vinyl monomer. As compared with the case where an image developing toner is applied, an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method that realize low-temperature fixability can be provided.

  According to the ninth aspect of the invention, the unsaturated polyester component of the toner particles comprising the crystalline polyester resin and the amorphous polyester resin having the unsaturated polyester component are cross-linked with the vinyl monomer. As compared with the case where the surface layer portion of the toner particle does not have a step of forming a cross-linked product by cross-linking, it is possible to provide a method for producing an electrostatic image developing toner that obtains an electrostatic image developing toner that achieves low-temperature fixability.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

  Hereinafter, an embodiment which is an example of the present invention will be described in detail.

(Static image developing toner)
The electrostatic charge image developing toner according to the exemplary embodiment (hereinafter, sometimes referred to as “toner”) includes a crystalline polyester resin and an amorphous polyester resin having an unsaturated polyester component (hereinafter referred to as “amorphous unsaturated”). And may be referred to as a “polyester resin”.
The surface layer portion of the toner particles includes a cross-linked product of the unsaturated polyester component of the amorphous unsaturated polyester resin and the vinyl monomer.
The tetrahydrofuran (THF) insoluble matter derived from the crosslinked toner particles is more than 2.0% by mass and 15.0% by mass or less.

Here, conventionally, in order to realize low-temperature fixability of toner, it is known to use a crystalline polyester resin together with an amorphous unsaturated polyester resin as a binder resin.
However, a crystalline polyester resin having a low melting temperature is exposed on the surface of the toner (toner particles), heat resistance (heat blocking property: phenomenon in which toner particles are welded to each other), fluidity is reduced, and hot offset (Phenomenon that adheres to the fixing member when the fixing temperature is too high) often occurs.

On the other hand, it is known that a coating layer is formed on the surface of toner particles by radical polymerization of a polymerizable monomer, graft polymerization, or seed polymerization (see, for example, the above-mentioned patent document).
When a coating layer is formed on the surface of the toner particles, the heat storage property and fluidity are lowered and the occurrence of hot offset is suppressed, but the low-temperature fixability tends to be hindered. This is because the penetration property to the transfer medium (for example, paper) is lowered due to the rise of the melting start temperature, and at the same time, the adhesiveness between the toners is lowered.

Therefore, in the toner according to the exemplary embodiment, the unsaturated polyester component of the amorphous unsaturated polyester resin and the vinyl are formed on the surface layer portion of the toner particles including the crystalline polyester resin and the amorphous unsaturated polyester resin. The toner particles are configured to contain a cross-linked product with the system monomer, and the THF-insoluble content of the toner particles is set in the above range.
As a result, the toner according to the exemplary embodiment achieves low-temperature fixability (for example, fixing at 135 ° C. or higher and 145 ° C. or lower (minimum fixing temperature)).
The reason for this is not clear, but is presumed to be as follows.

First, the cross-linked product constituting the surface layer portion of the toner particles is a reaction product of the unsaturated polyester component of the amorphous unsaturated polyester resin and the vinyl monomer, and corresponds to the tetrahydrofuran (THF) insoluble content of the toner particles. To do.
The amount of the cross-linked product constituting the surface layer portion of the toner particle, that is, the THF-insoluble content of the toner particle is in the above range means that the toner particle is entirely covered with the cross-linked film as the surface layer portion. It is thought that it is in a state.

On the other hand, the film of the cross-linked product constituting the surface layer portion of the toner particles is not a polymer obtained by polymerizing vinyl monomers, but an unsaturated polyester component of an amorphous unsaturated polyester resin exposed on the surface of the toner particles. Since it is a cross-linked product with a vinyl monomer, it is considered to be thinner than a coating layer formed by radical polymerization, graft polymerization, or seed polymerization of a conventional polymerizable monomer.
For this reason, although the surface layer portion of the toner particles has a structure harder than the inside, it is easily broken by the pressure at the time of fixing, and the binder resin (particularly crystalline polyester resin) contained in the toner particle oozes out. It is thought to be realized.

Therefore, it is considered that the toner according to the exemplary embodiment achieves low-temperature fixability.
In the toner according to the exemplary embodiment, the surface layer portion (cross-linked product) of the toner particles suppresses the exposure of the crystalline polyester resin to the surface of the toner particles. It is considered that a decrease in chargeability is also suppressed and a decrease in chargeability is also suppressed.
As a result, it is possible to obtain an image that achieves low-temperature fixability and suppresses image defects (for example, image density reduction and image fogging) even after thermal storage.
In addition, since the embedding of the external additive is suppressed by the surface layer portion (crosslinked product) of the toner particles, it is considered that the heat resistance blocking property and fluidity deterioration due to the embedding are also suppressed.

In addition, the toner according to the present exemplary embodiment, even when a release agent is included in the toner particles, the surface layer portion of the toner particles is easily broken due to the pressure during fixing, and the release agent contained in the toner particles oozes out. Is realized, and releasability with respect to the fixing member is also ensured.
Further, since the surface layer portion (crosslinked product) of the toner particles suppresses the exposure of the release agent to the toner particle surfaces, the heat storage property (heat blocking property: phenomenon in which toner particles are welded to each other) resulting from this. In addition, it is considered that a decrease in fluidity and a decrease in chargeability are also suppressed.

Hereinafter, the configuration of the toner according to the exemplary embodiment will be described in detail.
The toner according to the exemplary embodiment includes toner particles and, if necessary, an external additive.

First, toner particles will be described.
The toner particles include a crystalline polyester resin and an amorphous unsaturated polyester resin as a binder resin, and, if necessary, a colorant, a release agent, and other additives.

Further, the toner particles have a surface layer portion containing a crosslinked product of an unsaturated polyester component of an amorphous unsaturated polyester resin and a vinyl monomer.
The THF-insoluble matter derived from the crosslinked product of the toner is, for example, more than 2.0% by mass and 15.0% by mass or less (preferably 3.0 to 10.0% by mass, more preferably 4.0%. Mass% or more and 7.0 mass% or less).

The cross-linked product constituting the surface layer portion of the toner particles is a reaction product of the unsaturated polyester component of the amorphous unsaturated polyester resin and the vinyl monomer, and becomes a tetrahydrofuran (THF) insoluble content of the toner particles. That is, the THF insoluble matter corresponds to the amount of the cross-linked product.
If the THF-insoluble content is too small, the crystalline polyester resin is exposed, resulting in a decrease in heat storage (heat blocking property: phenomenon in which toner particles are welded together), fluidity and chargeability. It becomes easy.
On the other hand, if there is too much THF-insoluble matter, the surface layer portion (cross-linked product) of the toner particles will not easily be destroyed by the pressure during fixing, and the binder resin (especially crystalline polyester resin) will not exude and low temperature fixing will occur. Sex is difficult to be realized.

Here, the THF insoluble matter derived from the crosslinked product of the unsaturated polyester component of the amorphous unsaturated polyester resin and the vinyl monomer is measured as follows.
(1) 0.5 g to 1.0 g of toner particles are directly weighed into a 100 ml Erlenmeyer flask, sealed with 50 ml of THF, and ultrasonically dispersed.
(2) Weigh the membrane filter (mesh size 0.20 μm).
(3) Attach a membrane filter to the suction bottle and filter the solution of (1).
(4) The membrane filter in which the residue remains is placed in a vacuum dryer at 80 ° C. and left to dry for 30 minutes, and then allowed to cool and dry in a desiccator, and the filter is precisely weighed.
(5) The numerical value obtained by the following formula is defined as the THF-insoluble matter in the toner.
Formula: THF insoluble matter in toner = (B−A) ÷ S
A: Weight of membrane filter before filtration B: Weight of membrane filter after filtration S: Amount of sample collected

In addition, the amount of THF-insoluble matter derived from the cross-linked product of the unsaturated polyester component of the crystalline unsaturated polyester resin and the vinyl monomer can be determined by, for example, pyrolysis gas chromatography mass spectrometry ( It is also possible to calculate and measure from the peak area analyzed by pyrolysis GC / MS) and detected by a mass spectrometer.

The vinyl monomer will be described.
Examples of vinyl monomers include styrene monomers, acrylic esters, methacrylic esters, vinyl toluene, vinyl carbazole, vinyl chloride, and vinyl acetate.
Among these, it is at least one selected from a tyrene monomer, acrylic acid esters, and methacrylic acid esters because of its high reactivity with the unsaturated polyester component of the amorphous unsaturated polyester resin. It is good.
If the reactivity of the amorphous unsaturated polyester resin with the unsaturated polyester component is too low, a polymerization reaction occurs between the vinyl monomers without causing a crosslinking reaction with the unsaturated polyester component, and the toner particles It tends to form a vinyl polymer layer on the surface.

Here, as the styrene monomer, for example, styrene, alkyl-substituted styrene (for example, α-methylstyrene, vinylnaphthalene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, etc.), halogen-substituted styrene (for example, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, etc.), divinylbenzene and the like.
Of these, styrene is preferable.

Examples of the acrylate esters include alkyl acrylate esters (for example, n-methyl acrylate, n-ethyl acrylate, n-propyl acrylate, n-butyl acrylate, n-pentyl acrylate, n-acrylate). Hexyl, n-heptyl acrylate, n-octyl acrylate, n-decyl acrylate, n-dodecyl acrylate, n-lauryl acrylate, n-tetradecyl acrylate, n-hexadecyl acrylate, n-octadecyl acrylate, Isopropyl acrylate, isobutyl acrylate, t-butyl acrylate, isopentyl acrylate, amyl acrylate, neopentyl acrylate, isohexyl acrylate, isoheptyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, cycloacrylate Xyl, tert-butylcyclohexyl acrylate, etc.), aryl esters of alkyl acid (eg phenyl acrylate, biphenyl acrylate, diphenylethyl acrylate, t-butylphenyl acrylate, terphenyl acrylate, etc.), dimethylaminoethyl acrylate, Examples include diethylaminoethyl acrylate, methoxyethyl acrylate, 2-hydroxyethyl acrylate, β-carboxyethyl acrylate, acrylonitrile, acrylamide, and the like.
Among these, methyl acrylate or cyclohexyl acrylate is preferable.

Examples of the methacrylic acid ester monomers include methacrylic acid alkyl esters (for example, n-methyl methacrylate, n-ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, n-pentyl methacrylate, methacrylic acid). n-hexyl, n-heptyl methacrylate, n-octyl methacrylate, n-decyl methacrylate, n-dodecyl methacrylate, n-lauryl methacrylate, n-tetradecyl methacrylate, n-hexadecyl methacrylate, n-methacrylate Octadecyl, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, isopentyl methacrylate, amyl methacrylate, neopentyl methacrylate, isohexyl methacrylate, isoheptyl methacrylate, isoio methacrylate Chill, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, t-butyl cyclohexyl methacrylate, etc., aryl methacrylates (eg phenyl methacrylate, biphenyl methacrylate, diphenylethyl methacrylate, t-butylphenyl methacrylate, methacrylic acid terephthalate) Phenyl), dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, β-carboxyethyl methacrylate, acrylonitrile, methacrylamide and the like.
Among these, methyl methacrylate or cyclohexyl methacrylate is preferable.

The binder resin will be described.
As the binder resin, at least a crystalline polyester resin and an amorphous unsaturated polyester resin are applied.
The binder resin may be used in combination with other binder resins.

Here, the amorphous resin (amorphous unsaturated polyester resin) has only a stepwise endothermic change, not a clear endothermic peak in thermal analysis measurement using differential scanning calorimetry (DSC). It is a solid at normal temperature and is thermoplasticized at a temperature above the glass transition temperature. On the other hand, the crystalline resin (crystalline polyester resin) refers to a resin having a clear endothermic peak instead of a stepwise endothermic amount change in differential scanning calorimetry (DSC).
Specifically, for example. The crystalline resin (crystalline polyester resin) means that the half-value width of the endothermic peak when measured at a temperature rising rate of 10 ° C./min is within 10 ° C., and the amorphous resin (amorphous polyester resin) ) Means a resin having a full width at half maximum exceeding 10 ° C. or a resin in which no clear endothermic peak is observed.

The amorphous unsaturated polyester resin will be described.
The amorphous unsaturated polyester resin is, for example, an amorphous polyester resin having an unsaturated group (for example, a vinyl group) as an unsaturated polyester component.
Specifically, for example, the amorphous unsaturated polyester resin is a polycondensation product of a polyvalent carboxylic acid and a polyhydric alcohol, and an unsaturated polyester component is used as at least one of the polyvalent carboxylic acid and the polyhydric alcohol. It is preferable to use a monomer having an unsaturated group (for example, vinyl group).
In particular, from the viewpoint of forming a crosslinked structure with a vinyl monomer, the amorphous unsaturated polyester resin preferably includes a polyvalent carboxylic acid having an unsaturated group (for example, a vinyl group), and preferably a polyhydric alcohol. The non-crystalline unsaturated polyester resin may be a polycondensation product of a divalent carboxylic acid having an unsaturated group (for example, a vinyl group) and a divalent alcohol ( That is, it may be a linear polyester resin).

Examples of the divalent carboxylic acid having an unsaturated group (eg, vinyl group) include fumaric acid, maleic acid, maleic anhydride, citraconic acid, mesaconic acid, 2-pentenedioic acid, methylene succinic acid, and lower (C1-C5) Alkyl ester is mentioned.
These polyvalent carboxylic acids may be used alone or in combination of two or more.

Examples of the divalent alcohol include bisphenol A, hydrogenated bisphenol A, ethylene oxide and / or propylene oxide adduct of bisphenol A, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, propylene Examples include glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and neopentyl glycol.
Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
In addition to polyhydric alcohols, monovalent acids such as acetic acid and benzoic acid, and monohydric alcohols such as cyclohexanol and benzyl alcohol are also used together for the purpose of adjusting the acid value and hydroxyl value, if necessary. May be.
These polyhydric alcohols may be used alone or in combination of two or more.

Among the amorphous unsaturated polyester resins that are condensation polymers of these polycarboxylic acids and polyhydric alcohols, in particular, at least one divalent selected from fumaric acid, maleic acid, and maleic anhydride A polycondensation product of a carboxylic acid and a divalent alcohol is preferable.
That is, the unsaturated polyester component of the amorphous unsaturated polyester resin is preferably a component derived from at least one divalent carboxylic acid selected from fumaric acid, maleic acid, and maleic anhydride.

A component derived from at least one divalent carboxylic acid selected from fumaric acid, maleic acid, and maleic anhydride is highly reactive with a vinyl monomer and crosslinks with the vinyl monomer. It reacts and it becomes easy to form a crosslinked product on the surface layer portion of the toner particles. For this reason, it becomes easy to improve the glossiness of a fixed image.
If the unsaturated polyester component has a low reactivity with the vinyl monomer, it is difficult for the unsaturated polyester component and the vinyl monomer to form a cross-linked product on the surface layer portion of the toner particles, and the vinyl particles are formed on the surface of the toner particles. It becomes easy to form a polymer layer (vinyl polymer layer) of a single monomer.

  The method for producing the amorphous unsaturated polyester resin is not particularly limited, and is produced by a general polyester polymerization method in which a polycarboxylic acid and a polyhydric alcohol are reacted. For example, direct polycondensation, transesterification method, etc. These are manufactured separately depending on the type of monomer.

The weight average molecular weight (Mw) of the amorphous unsaturated polyester resin is, for example, preferably from 30,000 to 300,000, preferably from 30,000 to 200,000, more preferably from 35,000 to 150. , 000 or less.
The weight average molecular weight is measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC was performed with a THF solvent using a Tosoh column / TSKgel Super HM-M (15 cm) using a Tosoh GPC / HLC-8120 as a measuring device. The weight average molecular weight and the number average molecular weight are calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample from this measurement result. The same applies hereinafter.

The glass transition temperature (Tg) of the amorphous unsaturated polyester resin is, for example, preferably from 50 ° C. to 80 ° C., and more preferably from 50 ° C. to 65 ° C.
The glass transition temperature is a value obtained as the peak temperature of the endothermic peak obtained by differential scanning calorimetry (DSC). The same applies hereinafter.

  The content of the amorphous unsaturated polyester resin is, for example, preferably 40% to 95% by mass, desirably 50% to 90% by mass, and more desirably 60% to 85% by mass. It is as follows.

The crystalline polyester resin will be described.
Examples of the crystalline polyester resin include condensation polymers of polyvalent carboxylic acids and polyhydric alcohols.
Here, among the polycondensation products of polyvalent carboxylic acid and polyhydric alcohol exemplified below, from the viewpoint of realizing low-temperature fixability, the crystalline polyester resin is a polycondensation product of an aliphatic dicarboxylic acid and an aliphatic diol. It is good that it is.

Examples of the dicarboxylic acid (divalent carboxylic acid) include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. Aliphatic dicarboxylic acids such as 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malon Aromatic dicarboxylic acids such as acids and dibasic acids such as mesaconic acid; and the like, and anhydrides and lower alkyl esters thereof are also included, but not limited thereto.
Examples of the trivalent or higher carboxylic acid include specific aromatic carboxylic acids such as 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like. These anhydrides and their lower (1 to 3 carbon atoms) alkyl esters are exemplified.
Moreover, as polyvalent carboxylic acid, you may use together dicarboxylic acid which has a sulfonic acid group other than the said aliphatic carboxylic acid and aromatic carboxylic acid.
Furthermore, as the polyvalent carboxylic acid, in addition to the aliphatic carboxylic acid and the aromatic carboxylic acid, a dicarboxylic acid having a double bond may be used in combination.
These polyvalent carboxylic acids may be used alone or in combination of two or more.

  As the polyhydric alcohol, an aliphatic diol is desirable, and a linear aliphatic diol having a main chain portion having 7 to 20 carbon atoms is more desirable. When the aliphatic diol is branched, the crystallinity of the polyester resin is lowered and the melting temperature may be lowered. Further, when the main chain portion has less than 7 carbon atoms, when the polycondensation with the aromatic dicarboxylic acid is performed, the melting temperature becomes high and low temperature fixing may be difficult. On the other hand, when the number of carbons in the main chain portion exceeds 20, it is difficult to obtain practical materials. The number of carbon atoms in the main chain portion is more preferably 14 or less.

  Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol 1,18-octadecanediol, 1,14-eicosandecanediol and the like, but are not limited thereto. Among these, considering availability, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are desirable.

  Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

Among polyhydric alcohols, the amount of aliphatic diol used is desirably 80 mol% or more, and more desirably 90 mol% or more.
When the amount of the aliphatic diol used is too low, the crystallinity of the crystalline polyester resin is lowered and the melting temperature may be lowered.

  The method for producing the crystalline polyester resin is not particularly limited, and is produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification. Produced separately for different types.

If necessary, a polycarboxylic acid or a polyhydric alcohol may be further added at the final stage of the synthesis for the purpose of adjusting the acid value or the hydroxyl value.
Examples of the polyvalent carboxylic acid include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, Aliphatic carboxylic acids such as alkenyl succinic anhydride and adipic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid; 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4 -Aromatic carboxylic acids having at least three carboxyl groups in one molecule such as naphthalene tricarboxylic acid.
Examples of the polyhydric alcohol include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentylglycol, glycerin; cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A And aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct.

  The weight average molecular weight (Mw) of the crystalline polyester resin is preferably, for example, 6,000 or more and 35,000 or less.

The melting temperature of the crystalline polyester resin is, for example, preferably from 50 ° C. to 100 ° C., and preferably from 60 ° C. to 80 ° C.
In addition, melting temperature is the value calculated | required as the peak temperature of the endothermic peak obtained by the said differential scanning calorimetry (DSC). The crystalline polyester resin may show a plurality of melting peaks, but in the present embodiment, the maximum peak is regarded as the melting temperature.

  As content of crystalline polyester resin, the range of 3 mass% or more and 20 mass% or less is good, for example, It is 5 mass% or more and 18 mass% or less, More desirably, it is 7 mass% or more and 16 mass% or less. is there.

Other binder resins will be described.
Other binder resins include other crystalline resins (crystalline vinyl resins), other amorphous resins (for example, styrene / acrylic resins, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins). , Known amorphous resins such as polyether resins and polyolefin resins).
These other binder resins are blended within a range that does not affect the toner characteristics.

The colorant will be described.
The colorant is not particularly limited as long as it is a known colorant. For example, carbon black such as furnace black, channel black, acetylene black, and thermal black, inorganic pigments such as bengara, bitumen, and titanium oxide, fast yellow, disazo Azo pigments such as yellow, pyrazolone red, chelate red, brilliant carmine, para brown, phthalocyanine pigments such as copper phthalocyanine, metal-free phthalocyanine, flavantron yellow, dibromoanthrone orange, perylene red, quinacridone red, dioxazine violet Examples thereof include cyclic pigments.

  As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant. A plurality of colorants may be used in combination.

  As content of a coloring agent, the range of 1 to 30 mass parts is desirable with respect to 100 mass parts of binder resin.

The release agent will be described.
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester types such as fatty acid esters and montanic acid esters. Wax; and the like, but is not limited thereto.

  The melting point of the release agent is preferably 50 ° C. or higher, and more preferably 60 ° C. or higher, from the viewpoint of storage stability. Further, from the viewpoint of offset resistance, the temperature is desirably 110 ° C. or less, and more desirably 100 ° C. or less.

  As content of a mold release agent, it is with respect to 100 mass parts of binder resin, for example. A range of 2 parts by weight to 30 parts by weight is desirable.

Other additives will be described.
Examples of other additives include magnetic substances, charge control agents, inorganic powders, and the like.

The characteristics of the toner particles will be described.
The toner particles may be toner particles having a single layer structure, or toner particles having a so-called core / shell structure including a core (core particle) and a coating layer (shell layer) covering the core. May be.
In the case of toner particles having a core / shell structure, the coating layer (shell layer) includes an amorphous unsaturated polyester resin, while the core (core particle) includes a crystalline polyester resin and an amorphous non-crystalline polyester resin. Along with the saturated polyester resin, if necessary, a colorant, a release agent, and other additives may be included.
Note that the amorphous unsaturated polyester resin is not necessarily applied as the binder resin constituting the core (core particle), and other amorphous resin may be applied instead.

The toner particles have a glass transition temperature of the surface layer portion (portion constituted by a crosslinked product of the unsaturated polyester component of the amorphous unsaturated polyester resin and the vinyl monomer) inside (other than the surface layer portion). It is preferable that the glass transition temperature is higher than the glass transition temperature.
As a result, improvement in glossiness of the fixed image (that is, suppression of aggregation of toner particles in the toner image) and low temperature fixability are realized.

The toner particles preferably have two or more endothermic peaks at 60 ° C. or more and 90 ° C. or less in a DSC curve measured by a differential scanning calorimeter (DSC).
That is, the toner particles may be configured to contain a release agent together with the crystalline polyester resin and the amorphous unsaturated polyester resin, and the two or more endothermic peaks are derived from the crystalline resin and the release agent. This corresponds to the endothermic peak.
Thereby, both the low-temperature fixability of the toner and the releasability of the toner are realized.

The toner particles have a total content ratio of the crystalline resin (crystalline polyester) and the release agent (if included) on the surface of the toner particles after storage at 50 ° C. for 48 hours at a temperature of 20% or less (preferably 10% or less, more desirably 5% or less).
As a result, a decrease in heat storage property and fluidity is suppressed, and a decrease in chargeability is easily suppressed.
Here, the present abundance ratio is a value measured as follows.
The heat-treated toner is dyed with ruthenium, and the toner surface is observed with FE-SEM (scanning electron microscope). From the contrast and shape of the toner surface, the crystalline resin (crystalline polyester) and release The type agent was judged and the toner surface abundance ratio was calculated by image analysis. For the dyeing, a 0.5% aqueous solution of ruthenium tetroxide is used, and as a discrimination method, since the release agent and the crystalline resin are dyed with ruthenium, the crystalline resin and the release agent can be discriminated.

The volume average particle diameter of the toner particles is, for example, 2.0 μm or more and 10 μm or less, and preferably 4.0 μm or more and 8.0 μm or less.
As a method for measuring the volume average particle diameter of the toner particles, 0.5 mg to 50 mg of a measurement sample is added to 2 ml of a 5% by weight aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant. The electrolyte was added to 100 ml to 150 ml. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the above-mentioned Coulter Multisizer II type (manufactured by Beckman-Coulter) is used to produce particles using an aperture having an aperture diameter of 100 μm. The particle size distribution of particles having a diameter in the range of 2.0 μm to 60 μm is measured. The number of particles to be measured is 50,000.
For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volume cumulative distribution is subtracted from the small particle size side, and the particle size that becomes 50% cumulative is defined as the volume average particle size D50v.

The external additive will be described.
Examples of the external additive include inorganic particles. Examples of the inorganic particles include SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, and CaO. , K ₂ O, Na ₂ O, ZrO ₂ , CaO.SiO ₂ , K ₂ O. (TiO ₂ ) _n , Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO _{4 and the} like. .

The surface of the external additive may be hydrophobized in advance. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is usually about 1 part by mass or more and about 10 parts by mass with respect to 100 parts by mass of the inorganic particles, for example.

  The external addition amount of the external additive is preferably 0.5 parts by mass or more and 2.5 parts by mass or less with respect to 100 parts by mass of the toner particles.

A toner manufacturing method according to this embodiment will be described.
First, toner particles may be produced by a dry process (for example, a kneading and pulverization method), a wet process (for example, an aggregation coalescence method, a suspension polymerization method, a solution suspension granulation method, a solution suspension method, a solution emulsion aggregation method, or the like. ). There is no restriction | limiting in particular in these manufacturing methods, A well-known manufacturing method is employ | adopted.
Then, the unsaturated polyester component of the amorphous unsaturated polyester resin present in the surface layer portion of the obtained toner particles and the vinyl monomer are cross-linked to form a cross-linked product on the surface layer portion of the toner particles.

Specifically, for example, when toner particles are produced by an aggregation coalescence method,
Prepare at least a polyester resin particle dispersion in which crystalline polyester resin particles and amorphous polyester resin particles having an unsaturated polyester component are dispersed, and agglomerate at least the crystalline polyester resin particles and the amorphous polyester resin particles. A step of forming the first aggregated particles (first aggregation step);
The first aggregated particle dispersion in which the first aggregated particles are dispersed and the polyester resin particle dispersion in which the amorphous polyester resin particles having an unsaturated polyester component are dispersed are mixed, and the surface of the first aggregated particles is mixed. A step of aggregating the amorphous polyester resin particles to adhere to form second agglomerated particles (second agglomeration step);
Heating the second agglomerated particle dispersion in which the second agglomerated particles are dispersed, fusing and coalescing the second agglomerated particles to form toner particles (fusing and coalescing step);
A vinyl monomer and a polymerization initiator are added to the toner particle dispersion in which the toner particles are dispersed, and the unsaturated polyester component of the amorphous polyester resin and the vinyl monomer present in the surface layer portion of the toner particles. A step of forming a cross-linked product by cross-linking on the surface layer portion of the toner particles (cross-linked product forming step);
A method for producing a toner for developing an electrostatic charge image.

Details of each step will be described below.
In the following description, a method of obtaining toner particles containing a colorant and a release agent will be described. However, the colorant and the release agent are used as necessary. Of course, you may use other additives other than a coloring agent and a mold release agent.

-First aggregated particle forming step-
First, together with a resin particle dispersion in which resin particles are dispersed, for example, a colorant particle dispersion in which colorant particles are dispersed and a release agent dispersion in which release agent particles are dispersed are prepared.

The resin particles dispersed in the resin particle dispersion are crystalline polyester resin particles and amorphous unsaturated polyester resin particles.
In the case of applying two or more kinds of resin particles, the resin particle dispersion may be prepared as a single resin particle dispersion by preparing each resin particle dispersion and mixing each resin particle. Mixing may be performed when the dispersion swimming is mixed with the colorant particle dispersion and the release agent particle dispersion.

  The resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

Examples of the dispersion medium used for the resin particle dispersion include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together.

The surfactant is not particularly limited. For example, anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; amine salt type, quaternary ammonium salt type Nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based, and the like. Among these, an anionic surfactant and a cationic surfactant are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
Surfactant may be used individually by 1 type and may use 2 or more types together.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion include general dispersion methods such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of resin particles used, the resin particles may be dispersed in the resin particle dispersion using, for example, a phase inversion emulsification method.
The phase inversion emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to the organic continuous phase (O phase) to neutralize the aqueous medium. (W phase) is added to convert the resin from W / O to O / W (so-called phase inversion) to form a discontinuous phase and disperse the resin in an aqueous medium in the form of particles. It is.

Examples of the volume average particle diameter of the resin particles dispersed in the resin particle dispersion include a range of 0.01 μm to 1 μm, and may be 0.08 μm to 0.8 μm, or 0.1 μm to 0 μm. It may be 6 μm.
The volume average particle diameter of the resin particles is measured with a laser diffraction particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.). Hereinafter, unless otherwise specified, the volume average particle diameter of the particles is measured in the same manner.

  As content of the resin particle contained in a resin particle dispersion liquid, 5 mass% or more and 50 mass% or less are mentioned, for example, and 10 mass% or more and 40 mass% or less may be sufficient.

  In addition, similarly to resin particle dispersion, for example, a colorant dispersion and a release agent dispersion are also prepared. In other words, regarding the volume average particle size of the particles in the resin particle dispersion, the dispersion medium, the dispersion method, and the content of the particles, the colorant particles dispersed in the colorant dispersion and the release agent dispersed in the release agent dispersion are used. The same applies to the mold agent particles.

Next, the colorant particle dispersion and the release agent dispersion are mixed together with the resin particle dispersion.
In the mixed dispersion, the resin particles, the colorant particles, and the release agent particles are hetero-aggregated, and the resin particles, the colorant particles, and the release agent particles have a diameter close to the diameter of the desired toner particles. First aggregated particles (core aggregated particles) are formed.

Specifically, for example, a flocculant is added to the mixed dispersion, and the pH of the mixed dispersion is adjusted to acidic (for example, pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. After that, the resin particles are heated to a glass transition temperature (specifically, for example, the glass transition temperature of the resin particles −30 ° C. or higher and the Vicat softening temperature −10 ° C. or lower) to aggregate the particles dispersed in the mixed dispersion liquid To form first agglomerated particles.
In the first agglomerated particle forming step, for example, the flocculant is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is acidic (for example, pH is 2 or more). 5 or less) and, if necessary, after adding a dispersion stabilizer, the heating may be performed.

Examples of the flocculant include surfactants having a polarity opposite to that of the surfactant used as the dispersant added to the mixed dispersion, for example, inorganic metal salts and divalent or higher-valent metal complexes. In particular, when a metal complex is used as the flocculant, the amount of the surfactant used is reduced, and the charging characteristics are improved.
If necessary, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include metal salt polymers.
A water-soluble chelating agent may be used as the chelating agent. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid, iminodiacid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), and the like.
Examples of the addition amount of the chelating agent include a range of 0.01 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the resin particles, and 0.1 parts by mass or more and less than 3.0 parts by mass. There may be.

-Second aggregated particle forming step-
Next, the obtained first aggregated particle dispersion in which the first aggregated particles are dispersed and the amorphous unsaturated polyester resin particle dispersion in which the amorphous unsaturated polyester resin particles are dispersed are mixed.
And in this mixed dispersion liquid, it aggregates so that the particle | grains of an amorphous unsaturated polyester resin may adhere to the surface of a 1st aggregation particle, and an amorphous unsaturated polyester resin particle | grain is on the surface of a 1st aggregation particle. The attached second aggregated particles are formed.

Specifically, for example, in the first aggregated particle forming step, the first aggregated particles reach the target particle size (for example, the volume average particle size is 1.5 μm or more, desirably 2.5 μm or more and 6.5 μm or less). When the first agglomerated particle dispersion is mixed with the amorphous unsaturated polyester resin particle dispersion, the glass transition of the first agglomerated particles and the amorphous unsaturated polyester resin particles is mixed with the mixed dispersion. Heating is performed below the lower glass transition temperature of the temperature.
Then, the progress of aggregation is stopped by setting the pH of the mixed dispersion to a range of, for example, about 6.5 to 8.5.

  Here, in the amorphous unsaturated polyester resin particle dispersion, the volume average particle diameter of the amorphous unsaturated polyester resin particles to be dispersed includes, for example, a range of 0.01 μm or more and 1 μm or less, and 0.05 μm or more. It may be 0.8 μm or less, and may be 0.1 μm or more and 0.6 μm, but is particularly preferably less than 0.3 μm (300 nm).

  Thereby, the 2nd aggregated particle aggregated so that the amorphous unsaturated polyester resin particle may adhere to the surface of the 1st aggregated particle is obtained.

-Fusion / unification process-
Next, the second aggregated particle dispersion in which the second aggregated particles are dispersed is, for example, not less than the glass transition temperature of the amorphous unsaturated polyester resin (for example, 10 from the glass transition temperature of the amorphous unsaturated polyester resin). To 30 ° C. or higher) to fuse and coalesce the second aggregated particles to form toner particles.

-Crosslinked product forming step-
A vinyl monomer and a polymerization initiator are added to the toner particle dispersion in which the toner particles are dispersed, and the unsaturated polyester component of the amorphous unsaturated polyester resin and the vinyl single monomer existing on the surface layer of the toner particles. The polymer is cross-linked to form a cross-linked product by cross-linking in the surface layer portion of the toner particles. In other words, the toner particles are seed-polymerized with a vinyl monomer, so that the amorphous unsaturated polyester resin (its unsaturated polyester component) and the vinyl monomer present in the surface layer of the toner particles To form a crosslinked product.

  For example, the cross-linked product is formed under the conditions that the reaction temperature is 50 ° C. or higher and 100 ° C. or lower (desirably 60 ° C. or higher and 90 ° C. or lower), and the reaction time is 1 hour or longer and 7 hours or shorter (preferably 2 hours or longer and 5 hours or shorter). Good to do.

The polymerization initiator is preferably one that dissolves in the solvent of the toner particle dispersion (water is preferably used as the solvent), and a typical example is a water-soluble polymerization initiator. select.
Examples of the water-soluble polymerization initiator include hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, and bromomethyl peroxide. Benzoyl, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, tert-butyl hydroperoxide pertriphenylacetate, Tert-butyl formate, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl per-N- (3-toluyl) carbamate, ammonium bisulfate Um, sodium bisulfate, peroxides and the like; and others as mentioned, not limited to these.
Of these, persulfate initiators such as ammonium persulfate, potassium persulfate, and sodium persulfate are desirable. These free radical initiators may be used alone or in combination of two or more.

  Here, the addition amount of the vinyl monomer to the toner particle dispersion (its solid content) is, for example, 2.0% by mass or more and 15.0% by mass or less (preferably 4.0% by mass or more and 7.0% by mass). In the following, the addition amount of the polymerization initiator is preferably 0.3% by mass or more and 10.0% by mass or less (desirably 0.5% by mass or more and 7.0% by mass or less).

Through the above steps, a core material containing a mixed resin (mixed resin in which resin particles are fused and united) composed of crystalline polyester resin and amorphous unsaturated polyester resin particles, and amorphous unsaturated coating the core material. Toner particles (core / shell) comprising an amorphous unsaturated polyester resin composed of polyester resin particles (amorphous unsaturated polyester resin in which amorphous unsaturated polyester resin particles are fused and combined) Structural toner particles) are obtained.
In the surface layer portion of the toner particles, a crosslinked product of the unsaturated polyester component of the amorphous unsaturated polyester resin and the vinyl monomer is formed.

After the fusion and coalescence process, toner particles formed in the solution are dried through a known washing process, solid-liquid separation process, and drying process to obtain toner particles.
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.

  The toner according to the exemplary embodiment is manufactured, for example, by adding an external additive to the obtained dry toner particles and mixing them. Mixing is preferably performed by, for example, a V blender, a Henschel mixer, or a ladyge mixer. Further, if necessary, coarse toner particles may be removed using a vibration classifier, a wind classifier, or the like.

(Electrostatic image developer)
The electrostatic charge image developer according to the exemplary embodiment includes at least the toner according to the exemplary embodiment.
The electrostatic image developer according to this embodiment may be a one-component developer including only the toner according to this embodiment, or may be a two-component developer mixed with the toner and a carrier.

  There is no restriction | limiting in particular as a carrier, A well-known carrier is mentioned. Examples of the carrier include a resin-coated carrier, a magnetic dispersion carrier, a resin dispersion carrier, and the like.

  In the two-component developer, the mixing ratio (mass ratio) of the toner according to the exemplary embodiment and the carrier is preferably in the range of toner: carrier = 1: 100 to 30: 100, and about 3: 100 to 20: 100. The range of is more desirable.

(Image forming apparatus / image forming method)
Next, the image forming apparatus / image forming method according to the present embodiment will be described.
An image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and an electrostatic image development. A developing means for accommodating the developer and developing the electrostatic image formed on the image carrier as a toner image by the electrostatic image developer, and transferring the toner image formed on the image carrier onto the transfer target And a fixing unit that fixes the toner image transferred onto the transfer target. The electrostatic image developer according to the present embodiment is applied as the electrostatic image developer.

  In the image forming apparatus according to the present embodiment, for example, the part including the developing unit may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, A process cartridge that accommodates the electrostatic charge image developer according to the exemplary embodiment and includes a developing unit is preferably used.

  The image forming method according to the present embodiment contains a charging step for charging the image carrier, an electrostatic charge image forming step for forming an electrostatic charge image on the surface of the charged image carrier, and an electrostatic charge image developer. A developing step of developing the electrostatic image formed on the image carrier as a toner image with an electrostatic charge image developer, and a transfer step of transferring the toner image formed on the image carrier onto the transfer target; And a fixing step of fixing the toner image transferred onto the transfer medium. And as the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

  FIG. 1 is a schematic configuration diagram showing a four-tandem color image forming apparatus. The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the main body of the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a driving roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other from the left to the right in the drawing. The vehicle travels in the direction toward the unit 10K. A force is applied to the support roller 24 in a direction away from the drive roller 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the both. Further, an intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the driving roller 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K has yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The toner including the four color toners can be supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K described above have the same configuration, here, the first image that forms the yellow image disposed on the upstream side in the intermediate transfer belt traveling direction is formed. The unit 10Y will be described as a representative. Note that the second to fourth components are denoted by reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y) in the same parts as the first unit 10Y. Description of the units 10M, 10C, and 10K will be omitted.

The first unit 10Y includes a photoreceptor 1Y that functions as an image holding member. Around the photosensitive member 1Y, a charging roller 2Y for charging the surface of the photosensitive member 1Y to a predetermined potential, and the charged surface is exposed by a laser beam 3Y based on the color-separated image signal to form an electrostatic charge image. An exposure device (electrostatic image forming means) 3 for forming, a developing device (developing means) 4Y for supplying the charged toner to the electrostatic image and developing the electrostatic image, and transferring the developed toner image onto the intermediate transfer belt 20 A primary transfer roller 5Y (primary transfer unit) that performs the transfer and a photoconductor cleaning device (cleaning unit) 6Y that removes toner remaining on the surface of the photoconductor 1Y after the primary transfer are sequentially arranged.
The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roller under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described. First, prior to the operation, the surface of the photoreceptor 1Y is charged to a potential of about −600V to −800V by the charging roller 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate (volume resistivity at 20 ° C .: 1 × 10 ⁻⁶ Ωcm or less). This photosensitive layer usually has a high resistance (a resistance equivalent to that of a general resin), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image of a yellow print pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoreceptor 1Y in this way is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) by the developing device 4Y.

  In the developing device 4Y, for example, an electrostatic charge image developer according to the present embodiment including at least yellow toner and a carrier is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charged charge on the photoreceptor 1Y, and a developer roll (developer holder). Is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a primary transfer bias is applied to the primary transfer roller 5Y, and an electrostatic force from the photoreceptor 1Y toward the primary transfer roller 5Y acts on the toner image. Then, the toner image on the photoreceptor 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is a (+) polarity opposite to the polarity (−) of the toner, and is controlled to about +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner. The

  The intermediate transfer belt 20 onto which the four color toner images have been transferred in multiple layers through the first to fourth units is arranged on the image transfer surface side of the intermediate transfer belt 20, the support roller 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer means) 26 is connected to a secondary transfer portion. On the other hand, the recording paper (transfer object) P is fed at a predetermined timing to the gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other via the supply mechanism, and the secondary transfer bias is supported. Applied to the roller 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, so The toner image is transferred onto the recording paper P. Note that the secondary transfer bias at this time is determined according to the resistance detected by a resistance detecting means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

Thereafter, the recording paper P is sent to the pressure contact portions (nip portions) of the pair of fixing rolls in the fixing device (roll-type fixing unit) 28, and the toner image is fixed on the recording paper P, thereby forming a fixed image.
Examples of the transfer target 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, it is desirable that the surface of the transfer target is as smooth as possible. For example, coated paper in which the surface of plain paper is coated with resin, art for printing Paper or the like is preferably used.

The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.
The image forming apparatus exemplified above is configured to transfer the toner image onto the recording paper P via the intermediate transfer belt 20, but is not limited to this configuration, and the toner image is directly transferred from the photoreceptor. It may be a structure that is transferred to a recording sheet.

<Process cartridge, toner cartridge>
FIG. 2 is a schematic configuration diagram showing an embodiment of a preferred example of a process cartridge containing an electrostatic charge image developer according to this embodiment. In the process cartridge 200, a charging roller 108, a developing device 111, a photoconductor cleaning device 113, an opening 118 for exposure, and an opening 117 for static elimination exposure are combined using a mounting rail 116 together with the photoconductor 107. , And integrated. In FIG. 2, reference numeral 300 denotes a transfer target.
The process cartridge 200 is detachable from an image forming apparatus including a transfer device 112, a fixing device 115, and other components not shown.

  The process cartridge 200 shown in FIG. 2 includes a charging device 108, a developing device 111, a cleaning device 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. Can be combined. In the process cartridge according to the present embodiment, in addition to the photosensitive member 107, the charging device 108, the developing device 111, the cleaning device (cleaning means) 113, the opening 118 for exposure, and the opening 117 for static elimination exposure. At least one selected from the group consisting of:

  Next, the toner cartridge according to this embodiment will be described. The toner cartridge according to the present exemplary embodiment is a toner cartridge that is detachably attached to the image forming apparatus and stores at least a replenishment electrostatic image developing toner to be supplied to a developing unit provided in the image forming apparatus.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K can be attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are respectively the developing devices ( And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, although an embodiment explains this embodiment in detail, this embodiment is not limited to these examples at all. In the following description, “part” and “%” are all based on mass unless otherwise specified.

[Preparation of resin particle dispersion]
(Preparation of amorphous unsaturated polyester resin particle dispersion A)
In a heat-dried two-necked flask, 10 mol parts of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2,2) -2,2-bis (4- Hydroxyphenyl) propane 90 mol, terephthalic acid 10 mol, fumaric acid 65 mol, n-dodecenyl succinic acid 3 mol, acid component (total mol of terephthalic acid, fumaric acid, n-dodecenyl succinic acid) 0 .05 mol part of dibutyltin oxide is added, nitrogen gas is introduced into the container and heated in an inert atmosphere, and then subjected to a copolycondensation reaction at 150 ° C. to 230 ° C. for 12 to 20 hours. The pressure was gradually reduced at 250 ° C. to synthesize amorphous unsaturated polyester resin A.
The obtained amorphous unsaturated polyester resin A 3000 parts by mass, ion exchanged water 10000 parts by mass, and sodium dodecylbenzenesulfonate 90 parts by mass were charged into an emulsification tank of a high-temperature, high-pressure emulsifier (Cavitron CD1010), and then 130 ° C. After being heated and melted, it was dispersed at 110 ° C. at a flow rate of 3 L / m at 10,000 rpm for 30 minutes, passed through a cooling tank, and 30% solid content and an amorphous unsaturated polyester resin particle dispersion A having a volume average particle diameter D50v of 115 nm. Was made.

(Preparation of amorphous unsaturated polyester resin particle dispersion B)
Amorphous unsaturated polyester resin B was synthesized in the same manner as in preparation of amorphous unsaturated polyester resin particle dispersion A except that 65 mol parts of fumaric acid was changed to 65 mol parts of maleic acid, and the solid content was 30. %, An amorphous unsaturated polyester resin particle dispersion B having a volume average particle diameter D50v of 140 nm was obtained.

(Preparation of amorphous saturated polyester resin particle dispersion C)
Amorphous unsaturated polyester resin C was synthesized in the same manner as in preparation of amorphous unsaturated polyester resin particle dispersion A, except that 65 mol parts of fumaric acid was changed to 65 mol parts of n-dodecenyl succinic acid. An amorphous unsaturated polyester resin particle dispersion C having a 30% content and a volume average particle diameter D50v of 119 nm was obtained.

(Preparation of amorphous saturated polyester resin particle dispersion D)
The amorphous saturated polyester resin D was prepared in the same manner as in the preparation of the amorphous saturated polyester resin particle dispersion A except that 65 mol parts of fumaric acid and 3 mol parts of n-dodecenyl succinic acid were changed to 68 mol parts of terephthalic acid. Thus, an amorphous saturated polyester resin particle dispersion D having a solid content of 30% and a volume average particle diameter D50v of 140 nm was obtained.

(Preparation of amorphous saturated polyester resin particle dispersion E)
Amorphous unsaturated polyester resin B was synthesized in the same manner as in preparation of amorphous unsaturated polyester resin particle dispersion A, except that 65 mol parts of fumaric acid was changed to 65 mol parts of maleic anhydride. An amorphous unsaturated polyester resin particle dispersion E having 30% volume average particle diameter D50v of 140 nm was obtained.

(Preparation of amorphous unsaturated polyester resin particle dispersion F)
Amorphous unsaturated polyester resin F was synthesized in the same manner as in preparation of amorphous unsaturated polyester resin particle dispersion A, except that 65 mol parts of fumaric acid was changed to 65 mol parts of methylene succinic acid. An amorphous unsaturated polyester resin particle dispersion F having 30% and a volume average particle diameter D50v of 147 nm was obtained.

(Preparation of crystalline polyester resin particle dispersion)
Into a heat-dried three-necked flask, 45 mol parts of 1,9-nonanediol, 55 mol parts of dodecanedicarboxylic acid, and 0.05 mol parts of dibutyltin oxide were introduced, and nitrogen gas was introduced into the container to maintain an inert atmosphere. After the temperature was raised, the copolycondensation reaction was carried out at 150 ° C. to 230 ° C. for 2 hours, and then the temperature was gradually raised to 230 ° C. and stirred for 10 hours. When the mixture became viscous, it was air-cooled to stop the reaction. A crystalline polyester resin was synthesized. 3000 parts by mass of the obtained crystalline polyester resin, 10000 parts by mass of ion-exchanged water, and 90 parts by mass of sodium dodecylbenzenesulfonate are charged into an emulsification tank of a high-temperature, high-pressure emulsifier (Cavitron CD1010), and then heated to 130 ° C. Then, it was dispersed at 110 ° C. and a flow rate of 3 L / m at 10,000 rpm for 30 minutes and passed through a cooling tank to prepare a crystalline polyester resin particle dispersion having a solid content of 30% and a volume average particle diameter D50v of 125 nm.

[Preparation of colorant dispersion]
Carbon black (Regal 330 Cabot) 45 parts by mass, ionic surfactant Neogen R (Daiichi Kogyo Seiyaku) 5 parts by mass, ion-exchanged water 200 parts by mass are mixed and dissolved, and homogenizer (IKA Ultra Tarrax) is used for 10 minutes. Dispersion was then performed using an optimizer to obtain a colorant dispersion having a solid content of 20% and a center particle size of 245 nm.

[Preparation of release agent dispersion]
Paraffin wax (manufactured by Nippon Seiki Co., Ltd., HNP0190) 45 parts by mass of ionic surfactant Neogen R (Daiichi Kogyo Seiyaku) and 200 parts by mass of ion-exchanged water are heated to 120 ° C., and pressure discharge type gorin homogenizer Dispersion treatment was performed to obtain a release agent dispersion having a solid content of 20% and a center particle size of 219 nm.

[Preparation of styrene-containing resin particle dispersion]
70 parts by mass of styrene, 30 parts by mass of methyl methacrylate, 2 parts by mass of a nonionic surfactant (manufactured by Sanyo Kasei, Nonibol 400), and 3 parts by mass of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku, Neogen R) The emulsion was polymerized in a reaction kettle dissolved in 510 parts by mass of ion-exchanged water, and 50 parts by mass of ion-exchanged water in which 4 parts by mass of ammonium persulfate was dissolved was added while stirring and mixing for 20 minutes. Thereafter, the reaction kettle was purged with nitrogen, and then the kettle was heated to 70 ° C. and emulsion polymerization was continued for 5 hours. As a result, a styrene-containing resin particle dispersion (St-containing resin particle dispersion) having a solid content of 20% and a volume average particle diameter D50 of 220 nm was obtained.

[Production of styrene-containing resin particles]
The styrene-containing resin particle dispersion was separated with a centrifuge at 14000 rpm over 4 hours, so that the resin particle precipitate and the supernatant were separated. After adding ion-exchanged water to this precipitate and stirring and mixing it, it was again separated into a precipitate and a supernatant liquid at 14,000 rpm for 4 hours by a centrifuge. After repeating this operation 5 times, the obtained precipitate was dried by a vacuum dryer to obtain styrene-containing resin particles (St-containing resin particles).

[Production of toner particles]
(Preparation of toner particles A1)
Amorphous unsaturated polyester resin particle dispersion A 500 parts by mass, crystalline polyester resin particle dispersion 47 parts by mass, pigment dispersion 85 parts by mass, release agent dispersion 94 parts by mass, aluminum sulfate (manufactured by Wako Pure Chemical Industries, Ltd.) 5 parts by mass, 10 parts by mass of sodium dodecylbenzenesulfonate, 50 parts by mass of 0.3M nitric acid aqueous solution, and 500 parts by mass of ion-exchanged water were placed in a round stainless steel flask, and homogenizer (Ultra Turrax T-manufactured by IKA). 50) and then heated to 50 ° C. with stirring in an oil bath for heating. After maintaining at 50 ° C. and confirming that aggregated particles having a volume average particle size of about 5.5 μm are formed, an additional 30 parts by weight of amorphous unsaturated polyester resin particle dispersion A233 is added, and further 30 Held for a minute.
Subsequently, a 1N aqueous sodium hydroxide solution was slowly added until pH 7.0 was reached, and then the mixture was heated to 85 ° C. and kept for 3 hours while stirring was continued. A solution prepared by dissolving 1.0 part by mass of ammonium persulfate (APS) in 10 parts by mass of ion-exchanged water was added to the resulting dispersion, and 5.5 parts by mass of styrene (St) was added at a temperature of 8 ° C. A mixed solution mixed with 50 parts by mass and further mixed with 3 parts by mass of sodium dodecylbenzenesulfonate was added dropwise over 30 minutes and polymerized at 80 ° C. for 2 hours. The reaction product was filtered, washed with ion exchange water, and then dried using a vacuum dryer to obtain toner particles A1.

(Preparation of toner particles A2)
Except that the vinyl monomer to be added is changed from 5.5 parts by mass of styrene (St) to 4.95 parts by mass of styrene (St) and 0.55 parts by mass of butyl acrylate (BA). In the same manner as in the production, toner particles A2 were obtained.

(Preparation of toner particles A3)
A toner particle A3 was obtained in the same manner as in the preparation of the toner particle A2, except that the amorphous unsaturated polyester resin particle dispersion A was changed to the dispersion B.

(Preparation of toner particles A4)
Preparation of toner particles A3 except that the vinyl monomer to be added is changed from 4.95 parts by mass of styrene (St) and 0.55 parts by mass of butyl acrylate to 5.5 parts by mass of methyl methacrylate (MMA). In the same manner, toner particles A4 were obtained.

(Preparation of toner particles A5)
Toner particles A5 were obtained in the same manner as in the preparation of toner particles A1, except that the vinyl monomer to be added was changed from 5.5 parts by mass of styrene (St) to 4.125 parts by mass of styrene (St).

(Preparation of toner particles A6)
Toner particles A6 were obtained in the same manner as in the preparation of toner particles A1, except that the vinyl monomer to be added was changed from 5.5 parts by mass of styrene (St) to 1.375 parts by mass of styrene (St).

(Preparation of toner particles A7)
A toner particle A7 was obtained in the same manner as in the preparation of the toner particle A1, except that the amorphous unsaturated polyester resin particle dispersion A was changed to the dispersion E.

(Preparation of toner particles A8)
Except that the amorphous unsaturated polyester resin particle dispersion A was changed to the dispersion F, toner particles A8 were obtained in the same manner as in the preparation of the toner particles A1.

(Preparation of toner particles A9)
Toner particles A9 were obtained in the same manner as in the preparation of toner particles A1, except that the vinyl monomer to be added was changed from 5.5 parts by mass of styrene (St) to 5.5 parts by mass of divinylbenzene.

(Preparation of toner particles A10)
Toner particles A10 were obtained in the same manner as in the preparation of toner particles A1, except that the vinyl monomer to be added was changed from 5.5 parts by mass of styrene (St) to 5.5 parts by mass of cyclohexyl acrylate.

(Preparation of toner particles A11)
Toner particles A11 were obtained in the same manner as in the preparation of toner particles A1, except that the step of adding a vinyl monomer to the obtained dispersion was not performed.

(Preparation of toner particles A12)
Except for changing the amorphous unsaturated polyester resin particle dispersion A to the dispersion D, toner particles A12 were obtained in the same manner as in the preparation of the toner particles A1.

(Preparation of toner particles A13)
Except that the amorphous unsaturated polyester resin particle dispersion A was changed to the dispersion C, toner particles A13 were obtained in the same manner as in the preparation of the toner particles A1.

(Preparation of toner particles A14)
Toner particles A14 were obtained in the same manner as in the preparation of toner particles A1, except that the vinyl monomer to be added was changed from 5.5 parts by mass of styrene (St) to 13.75 parts by mass of styrene (St).

(Preparation of toner particles A15)
Along with the additional amorphous unsaturated polyester resin particle dispersion, 5.5 parts by mass of a styrene-containing resin fine particle dispersion (St-containing resin particles) is added, and a vinyl monomer, ammonium persulfate, Toner particles A15 were obtained in the same manner as in the preparation of toner particles A1, except that the step of adding ion-exchanged water was not performed.

(Preparation of toner particle A16)
To 100 parts by mass of untreated toner particles A11 with respect to the toner surface, 5.5 parts by mass of styrene-containing resin fine particles (St-containing resin particles) are added, and blended at 700 rpm for 12 minutes by a hybridizer, thereby producing toner particles A16. Got.

(Preparation of toner particle A17)
A toner particle A17 was obtained in the same manner as in the preparation of the toner particle A1, except that the crystalline polyester resin particle dispersion was not used.

(Preparation of toner particles A18)
Toner particles A18 are obtained in the same manner as in the preparation of toner particles A1, except that ammonium persulfate (APS) is changed to 1.0 part by mass of a hydrophobic polymerization initiator (compound name: azobisisobutyronitrile (AIBN)). It was.

[Production of toner]
(Preparation of Toners A1 to A18)
1.5 parts by mass of hydrophobic silica (manufactured by Cabot, TS720) was added to 50 parts by mass of each toner particle A (A1 to A18), and blended with a sample mill to obtain toners A1 to A18.

[Production of developer]
A pressure kneader with 500 parts of toluene together with 100 parts of ferrite particles (manufactured by Powder Tech Co., Ltd., average particle size 50 μm) and 1.5 parts of methyl methacrylate resin (manufactured by Mitsubishi Rayon Co., Ltd., molecular weight 95,000, component ratio of 10,000 or less). The mixture was stirred and mixed at room temperature for 15 minutes, then heated to 70 ° C. while mixing under reduced pressure to distill off toluene, then cooled, and classified using a 105 μm sieve to obtain a resin-coated ferrite carrier.
This resin-coated ferrite carrier and the above-described externally added toners A1 to A13 were mixed to prepare two-component electrostatic charge image developers A1 to A13 having a toner concentration of 7% by weight.

[Examples 1 to 10, Comparative Examples 1 to 8]
The obtained toners and developers were used as toners and developers of Examples 1 to 10 and Comparative Examples 1 to 8, and the following evaluations were performed. The results are shown in Tables 1 to 3.

(Evaluation)
-THF insoluble matter in toner-
The THF-insoluble matter (cross-linked product) of the toner was determined as described above by using the MS part of the ion trap type GC-MS (POLALIS Q) manufactured by Thermo Fisher and the direct sample introduction method as a measuring instrument.

-Presence ratio of crystalline resin and release agent on toner particle surface after heat storage-
The abundance ratio of the crystalline resin and the release agent on the surface of the toner particles after heat storage was determined as described above.

-Number of endothermic peaks in DSC curve-
Differential scanning calorimeter (DSC) [Apparatus name: manufactured by Mac Science: DSC3110, thermal analysis system 001, temperature: 10 ° C / min from 0 ° C to 150 ° C, hold at 150 ° C for 5 minutes, 150 ° C In the DSC curve obtained by decreasing the temperature from -10 to 0 ° C. using liquid nitrogen at −10 / min, holding at 0 ° C. for 5 minutes, and increasing the temperature from 0 ° C. to 150 ° C. at 10 ° C./min. The endothermic peak number at 60 ° C. or higher and 90 ° C. or lower was examined.

-Heat resistance blocking property of toner-
10 g of each toner was weighed on a propylene cup and allowed to stand in an environment of 50 ° C. and 50% RH for 17 hours, and the blocking (aggregation) state was evaluated according to the following criteria.
◎: When the cup is tilted, the toner flows more smoothly. ○: When the cup is moved, the toner gradually collapses and begins to flow. Δ: A block body is generated. When the tip is sharp, it collapses. ×: The block body It occurs, and it is hard to collapse even if it hits with a pointed object.

-Image density-
The image density was evaluated as follows. Measurement was performed with an X-rite 404 densitometer. If the image density is 1.40 or more, there is no problem in actual use.

-Image fog-
In an environmental room at room temperature of 32 ° C. and humidity of 75%, the obtained developer is set in a developer of a modified Docucolor 500 manufactured by Fuji Xerox Co., Ltd., and 5,000 continuous printouts are performed. Density, fogging in the background area and character image were evaluated. The fog was evaluated by visually observing the non-image area, and graded from G1 (no fog) to G5 (image fog was evaluated as follows). Usually, if it is G2 or less, it can be determined that there is no problem in image quality.

-Low temperature fixability (minimum fixing temperature)-
Low temperature fixability (minimum fixing temperature) was evaluated as follows.
Each developer is applied to Fuji Xerox Co. Color Paper (J paper) using Fuji Xerox Co., Ltd. DocuCentreColor 500 remodeling machine (modified using an external fixing machine with variable fusing temperature). A solid toner image was formed by adjusting to 13.5 g / m ² . After the toner image was produced, the toner image was fixed using an external fixing machine at a fixing speed of 150 mm / sec under Nip 6.5 mm.
Fix the toner image by increasing the fixing temperature in steps of 130 ° C to 5 ° C, crease the inside of the solid part of the fixed image on the paper, crease inside, and wipe the part where the fixed image is destroyed with tissue paper The white line width was measured and evaluated according to the following evaluation criteria.
The fixing temperature at which the circle is marked is the minimum fixing temperature, and the minimum fixing temperature is preferably less than 150 ° C.
◎: The white line width is less than 0.2 mm. ○: The white line width is 0.2 mm or more and less than 0.4 mm. Δ: The white line width is 0.4 mm or more and 0.8 mm or less. X: The white line width exceeds 0.8 mm

From the above results, it can be seen that in this example, better results were obtained with respect to image strength (low temperature fixability) than in the comparative example.
In addition, it can be seen that in this example, better results were obtained for evaluation of heat blocking resistance, image density, and image fog as well as image strength (low temperature fixability) as compared with the comparative example.

1Y, 1M, 1C, 1K, 107 photoconductor (image carrier)
2Y, 2M, 2C, 2K, 108 Charging roller 3Y, 3M, 3C, 3K Laser beam 3, 110 Exposure device 4Y, 4M, 4C, 4K, 111 Developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer rollers 6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K Developer cartridge 10Y, 10M, 10C, 10K Unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller (transfer means)
28, 115 Fixing device (fixing means)
30 Intermediate transfer member cleaning device 112 Transfer device 116 Mounting rail 117 Opening 118 for static elimination exposure Opening 200 for exposure Process cartridge,
P, 300 Recording paper (transfer object)

Claims (9)

A crystalline polyester resin and an amorphous polyester resin having an unsaturated polyester component, wherein the surface layer portion includes a cross-linked product of the unsaturated polyester component and a vinyl monomer, and the inside is the crystalline polyester. 15. A resin and an amorphous polyester resin having an unsaturated polyester component are included, the composition does not contain the crosslinked product, and the tetrahydrofuran (THF) insoluble content derived from the crosslinked product exceeds 2.0% by mass. An electrostatic image developing toner having toner particles of 0% by mass or less.   2. The electrostatic image developing toner according to claim 1, wherein the unsaturated polyester component is a component derived from at least one polycarboxylic acid selected from fumaric acid, maleic acid, and maleic anhydride.   The electrostatic charge image developing toner according to claim 1, wherein the vinyl monomer is at least one selected from styrene monomers, acrylic acid esters, and methacrylic acid esters.   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1. Containing the toner for developing an electrostatic charge image according to any one of claims 1 to 3,
A toner cartridge to be attached to and detached from the image forming apparatus. A developing means for accommodating the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus. An image carrier,
Charging means for charging the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic image developer according to claim 4 and developing the electrostatic image formed on the image carrier as a toner image by the electrostatic image developer;
Transfer means for transferring a toner image formed on the image carrier onto a transfer target;
Fixing means for fixing the toner image transferred onto the transfer medium;
An image forming apparatus including a. A charging step for charging the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing the electrostatic image formed on the image carrier as a toner image with the electrostatic image developer according to claim 4;
A transfer step of transferring a toner image formed on the image carrier onto a transfer target;
A fixing step of fixing the toner image transferred onto the transfer medium;
An image forming method comprising: Preparing at least a polyester resin particle dispersion in which crystalline polyester resin particles and amorphous polyester resin particles having an unsaturated polyester component are dispersed, at least the crystalline polyester resin particles and the amorphous polyester resin A step of agglomerating the particles to form first agglomerated particles;
A first aggregated particle dispersion in which the first aggregated particles are dispersed and a polyester resin particle dispersion in which amorphous polyester resin particles having an unsaturated polyester component are dispersed are mixed, and the first aggregated particles are mixed. A step of aggregating the amorphous polyester resin particles on the surface thereof to form second agglomerated particles,
Heating the second aggregated particle dispersion in which the second aggregated particles are dispersed, fusing and coalescing the second aggregated particles to form toner particles;
A vinyl monomer and a polymerization initiator are added to the toner particle dispersion in which the toner particles are dispersed, and the unsaturated polyester component of the amorphous polyester resin and the vinyl present in the surface layer portion of the toner particles. Cross-linking with a monomer, and forming a cross-linked product by the cross-linking on the surface layer of the toner particles;
The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 3.