JP6864828B2 - Toner for static charge image development, static charge image developer, toner cartridge, process cartridge, image forming apparatus and image forming method - Google Patents

Description

The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developing agent, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

Methods for visualizing image information, such as electrophotographic methods, are currently used in various fields. In the electrophotographic method, an electrostatic charge image is formed as image information on the surface of an image holder by forming an electrostatic charge and an electrostatic charge image. Then, a toner image is formed on the surface of the image holder with a developer containing toner, the toner image is transferred to a recording medium, and then the toner image is fixed on the recording medium. Through these steps, the image information is visualized as an image.

For example, Patent Document 1 states, "In a toner for static charge image development containing toner particles having a core-shell structure in which a shell layer is provided on the surface of the core particles, the core particles have a styrene acrylic resin and a mold release agent. , Toner for electrostatic charge image development in which the shell layer contains a styrene acrylic modified polyester resin. "

Patent Document 2 states, "In a toner for static charge image development containing toner particles having a core-shell structure in which a shell layer is provided on the surface of the core particles, the core particles contain a styrene-acrylic resin and a polyester resin. A toner for static charge image development in which the shell layer contains a styrene-acrylic modified polyester resin. ”Is disclosed.

Patent Document 3 states that "a toner for developing an electrostatic charge image, which is composed of toner particles containing a binder resin having at least a polyester resin and a styrene acrylic resin, a colorant and a mold release agent, and the toner particles are made of a polyester resin. The styrene acrylic resin and the release agent are dispersed as domain phases in the matrix phase, and the domain phase composed of the styrene acrylic resin and the domain phase formed by the release agent are present adjacent to each other. Toner for developing an electrostatic charge image. ”Is disclosed.

Japanese Unexamined Patent Publication No. 2012-247655 Japanese Unexamined Patent Publication No. 2013-109246 Japanese Unexamined Patent Publication No. 2016-53677

An object of the present invention is to have a core portion containing only a styrene (meth) acrylic resin as a binder resin and a shell layer covering the core portion and containing a mold release agent containing a non-crystalline resin and a hydrocarbon wax. It has toner particles or toner particles that cover a core portion containing only an unmodified polyester resin as a binder resin and a shell layer containing a release agent containing a non-crystalline resin and a hydrocarbon wax. Compared to the toner for electrostatic charge image development, the deterioration of thermal storage property is suppressed, and when the recording media on which the toner image is fixed are stacked, the fixed image after fixing on the recording medium is transferred to another recording medium (hereinafter referred to as the phenomenon). , Also referred to as “set-off of fixed image”), to provide a toner for developing an electrostatic charge image.

The above problem is solved by the following means.

The invention according to <1 > is
A core portion containing at least a non-crystalline resin (A) containing a styrene (meth) acrylic resin and a styrene (meth) acrylic-modified polyester resin, and the core portion are coated with at least the non-crystalline resin (B) and a hydrocarbon. It has a shell layer containing a mold release agent containing a styrene wax, and has toner particles having
A toner for static charge image development in which 70% or more of the release agents are present within 1000 nm from the surface of the toner particles.

The invention according to <2 > is
The toner for static charge image development according to < 1 > , wherein the exposure rate of the release agent on the surface of the toner particles is 1% or more and 6% or less.

The invention according to <3 > is
The release agent is a release agent having at least one endothermic peak obtained in the second heating process by a differential scanning calorimeter (DSC) in the range of 60 ° C. or higher and 100 ° C. or lower < 1 > or < 2. > The toner for developing an electrostatic charge image.

The invention according to <4 > is
The toner for static charge image development according to any one of < 1 > to < 3 > , wherein the toner particles contain a metal having a divalent ionic valence.

The invention according to <5 > is
The toner for developing an electrostatic charge image according to < 4 > , wherein the metal contains at least Mg.

The invention according to <6 > is
The mass ratio of the styrene (meth) acrylic resin to the styrene (meth) acrylic-modified polyester resin (styrene (meth) acrylic resin / styrene (meth) acrylic-modified polyester resin) is 80/20 or more and 95/5 or less. The toner for static charge image development according to any one of <1 > to < 5 >.

The invention according to <7 > is
In the styrene (meth) acrylic-modified polyester resin, the mass ratio of the styrene (meth) acrylic segment to the polyester segment (styrene (meth) acrylic segment / polyester segment) is 5/95 or more and 30/70 or less < 1 > ~. The toner for developing an electrostatic charge image according to any one of <6 >.

The invention according to <8 > is
A static charge image developer containing the toner for static charge image development according to any one of < 1 > to < 7 >.

The invention according to <9 > is
The toner for static charge image development according to any one of <1 > to < 7 > is housed,
A toner cartridge that is attached to and detached from the image forming device.

The invention according to <10 > is
A developing means for accommodating the electrostatic charge image developer according to < 8 > and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer is provided.
A process cartridge that is attached to and detached from the image forming device.

The invention according to <11 > is
Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means for accommodating the electrostatic charge image developer according to < 8 > and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus comprising.

The invention according to <12 > is
The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to < 8 >.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.

According to the invention according to < 1 > , a shell containing a core portion containing only a styrene (meth) acrylic resin as a binder resin and a core portion, and containing a release agent containing a non-crystalline resin and a hydrocarbon wax. It has a toner particle with a layer, or a core portion containing only an unmodified polyester resin as a binder resin, and a shell layer containing a mold release agent containing a non-crystalline resin and a hydrocarbon wax. A static charge image development toner that suppresses deterioration of heat storage property and suppresses the occurrence of set-off of a fixed image as compared with a static charge image development toner having toner particles is provided.
According to the invention according to < 2 > , as compared with the case where the exposure rate of the release agent on the surface of the toner particles exceeds 6%, the set-off of the fixed image occurs while obtaining better heat storage property. A toner for developing an electrostatic charge image, which is effective in suppressing the above-mentioned effects, is provided.
According to the invention according to < 3 > , the release agent is a release agent having one or more endothermic peaks obtained in the second heating process by a differential scanning calorimeter (DSC) only in the range exceeding 100 ° C. A toner for developing an electrostatic charge image, which is superior in low-temperature fixability as compared with a certain case, is provided.
According to the invention according to < 4 > or < 5 > , a toner for electrostatic charge image development having excellent low-temperature fixability as compared with the case where the toner particles contain only a metal having an ionic valence of trivalent or higher as a metal. Is provided.
According to the invention according to < 6 > , the mass ratio of the styrene (meth) acrylic resin to the styrene (meth) acrylic-modified polyester resin (styrene (meth) acrylic resin / styrene (meth) acrylic-modified polyester resin) is 80. Provided is a static charge image developing toner that is effective in suppressing the occurrence of set-off of a fixed image while obtaining better heat storage property than in the case of less than / 20 or more than 95/5.
According to the invention according to < 7 > , in the styrene (meth) acrylic modified polyester resin, the mass ratio of the styrene (meth) acrylic segment to the polyester segment (styrene (meth) acrylic segment / polyester segment) is less than 5/95 or Provided is a toner for static charge image development which is effective in suppressing the occurrence of set-off of a fixed image while obtaining better heat storage property as compared with the case where the amount exceeds 30/70.
According to the invention according to < 8 > , < 9 > , < 10 > , < 11 > , or < 12 > , the core part and the core part containing only styrene (meth) acrylic resin as a binder resin are covered and non-coated. A non-crystalline resin and a core portion containing only a toner particle having a shell layer containing a release agent containing a crystalline resin and a hydrocarbon wax, or a core portion containing only an unmodified polyester resin as a binder resin, and a non-crystalline resin and Compared to the case where a toner for static charge image development having toner particles having a shell layer containing a mold release agent containing a hydrocarbon wax is applied, the toner has heat storage property and the fixed image is set off. An electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method for suppressing generation is provided.

It is a schematic block diagram which shows an example of the image forming apparatus which concerns on this embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

Hereinafter, embodiments that are an example of the present invention will be described.

<Toner for static charge image development>
The toner for static charge image development according to the present embodiment (hereinafter, also referred to as “toner”) is a core containing at least a non-crystalline resin (A) containing a styrene (meth) acrylic resin and a styrene (meth) acrylic-modified polyester resin. It has a toner particle having a portion, a shell layer that covers the core portion and contains at least a non-crystalline resin (B) and a mold release agent containing a hydrocarbon wax.
Then, 70% or more of the total release agents are present within 1000 nm from the surface of the toner particles.

Here, in recent years, in the field of toners for developing electrostatic charge images, toners having excellent low-temperature fixing have been demanded in response to demands from the market. As one of the low-temperature fixing techniques, a technique of using a styrene (meth) acrylic-modified polyester resin together with a styrene (meth) acrylic resin as a binder resin for toner particles is known.

However, with toner using a styrene (meth) acrylic-modified polyester resin, set-off of the fixed image may occur. The set-off of the fixed image is a phenomenon in which when the recording media on which the toner image is fixed are stacked, the fixed image after fixing on the recording medium is transferred to another recording medium. Specifically, for example, when a large amount of a recording medium on which a fixed image is formed (hereinafter, also referred to as “printed matter”) is output in a short time and stacked in a discharge container called a finisher tray, the fixed image of the printed matter is displayed. A load is applied due to the heat of the printed matter and its own weight. Therefore, after that, in the stacked printed matter, the fixed image of the printed matter in the lower layer may be lost and adhere to the back surface of the printed matter in the upper layer. In particular, a printed matter having a fixed image formed on both sides tends to receive heat and accumulate heat as compared with a printed matter having a fixed image formed on one side of a recording medium, so that the fixed image tends to set off.
In the fixing image using the toner using the styrene (meth) acrylic resin and the styrene (meth) acrylic-modified polyester resin, the styrene (meth) acrylic portion and the polyester portion have a sea-island structure. As for the set-off of the fixed image, it is considered that the styrene (meth) acrylic portion of the fixed image is likely to be set-off.

On the other hand, a technique of unevenly distributing the release agent on the surface layer side of the toner particles is also known. In this respect, if the release agent is unevenly distributed on the surface layer side of the toner particles, the release agent easily exudes from the toner particles, and the release agent also easily exudes from the fixed image. Therefore, it is considered that the set-off of the fixed image is suppressed by the exudation of the release agent from the fixed image.

However, if the release agent is unevenly distributed on the surface layer side of the toner particles, the proportion of the release agent exposed on the surface of the toner particles increases, and the thermal storage property of the toner tends to decrease. Specifically, for example, in a high-temperature and high-humidity environment, the toner particles filled in the toner cartridge are blocked from each other, causing problems such as a decrease in toner discharge.

On the other hand, the toner according to the present embodiment can suppress the deterioration of heat storage property and the occurrence of set-off of the fixed image by the above configuration. The reason is presumed as follows.

In the toner particles having a core-shell structure, the shell layer is impregnated with a binder resin and a mold release agent, and 70% or more of the mold release agents are present within 1000 nm from the surface of the toner particles. .. As a result, the release agent is unevenly distributed on the surface layer side of the toner particles, and the release agent easily exudes from the toner particles.

The core portion contains a styrene (meth) acrylic resin and a styrene (meth) acrylic-modified polyester resin. Here, the styrene acrylic (meth) acrylic resin has a particularly high affinity with the hydrocarbon wax among the release agents, so that the release agent domains contained in the shell layer are relatively unevenly distributed on the core portion side. It becomes easier and the tendency to be dispersed in a nearly uniform state over the entire surface of the core portion increases. That is, the release agent is unevenly distributed on the surface layer (shell layer) of the toner particles, and although it exists in a nearly uniform state over the entire surface of the toner particles, it tends to be difficult to be exposed on the surface of the toner particles. .. As a result, deterioration of the thermal storage property of the toner is suppressed.

Here, in the core portion of the toner particles, a sea-island structure is formed in which the styrene (meth) acrylic-modified polyester resin forms a dispersed phase (island portion) and the styrene (meth) acrylic resin forms a continuous phase (sea portion). Further, the styrene (meth) acrylic-modified polyester resin has a higher affinity with the styrene (meth) acrylic resin than the unmodified polyester resin, and is easily dispersed uniformly by the styrene (meth) acrylic resin which is the main resin. Therefore, on the surface of the core portion, that is, near the interface with the shell layer, the tendency of the styrene (meth) acrylic-modified polyester resin to form an island portion in a nearly uniform state increases.

Therefore, in the shell layer, the domains of the hydrocarbon wax having a high affinity with the styrene (meth) acrylic resin are likely to be unevenly distributed on the core portion side, and are dispersed in a nearly uniform state over the entire surface of the core portion. It is thought that the tendency to become will increase. That is, the release agent containing the hydrocarbon wax is unevenly distributed on the surface layer (shell layer) of the toner particles, and although it exists in a nearly uniform state over the entire surface of the toner particles, it is difficult to be exposed on the surface of the toner particles. It is thought that the tendency to become a state will increase.

In this state, the toner particles (toner) containing the release agent are less likely to be exposed to the surface of the release agent, and it is possible to suppress deterioration of heat storage property. On the other hand, since the release agent is unevenly distributed on the surface layer side of the toner particles and exists in a nearly uniform state over the entire surface layer side of the toner particles, the release agent easily exudes from the fixing image, and the fixing image is described above. Set-off is suppressed.

In the case of the core portion containing styrene (meth) acrylic resin alone as the binder resin, the domain of the release agent tends to be unevenly distributed on the core portion side, but the uniformity over the entire surface of the core portion tends to decrease. is there. The reason is that when styrene (meth) acrylic modified polyester resin is contained, this has a nearly uniform island-like structure on the surface side of the core part, and the release agent is styrene (meth) in the sea part, which has a higher affinity than the island part. There is an increasing tendency for the core to be evenly distributed and arranged on the acrylic resin side, but when the entire surface of the core is made of styrene (meth) acrylic resin, there is no sea-island structure, so the surface side of the core This is because there is an increasing tendency for the dispersion of the release agent to be biased. Therefore, it becomes difficult for the release agent to partially exude from the fixed image, and the tendency for the fixed image to set off increases. On the other hand, in the case of the core portion containing the unmodified polyester resin alone as the binder resin, the domain of the release agent having a low affinity with the unmodified polyester resin tends to be exposed on the surface of the toner particles. Therefore, the thermal storage property of the toner tends to decrease.

From the above, the toner according to the present embodiment can suppress the deterioration of heat storage property and suppress the occurrence of set-off of the fixed image.
Further, as the toner according to the present embodiment, by applying toner particles having a core portion containing at least a non-crystalline resin (A) containing a styrene (meth) acrylic resin and a styrene (meth) acrylic-modified polyester resin, the toner is applied. Low temperature fixability is also realized.

Hereinafter, the details of the toner according to this embodiment will be described.

The toner according to the present embodiment is composed of toner particles and, if necessary, an external additive.

[Toner particles]
The toner particles have a core portion and a shell layer that covers the core portion.

(Core part)
The core portion contains at least a non-crystalline resin (A) containing a styrene (meth) acrylic resin and a styrene (meth) acrylic-modified polyester resin as a binder resin. If necessary, the core portion may contain at least one of a non-crystalline resin (A) other than the styrene (meth) acrylic resin and the styrene (meth) acrylic-modified polyester resin, and the other binder resin. Further, the core portion may contain a colorant and other additives, if necessary.

-Styrene (meth) acrylic resin-
The styrene (meth) acrylic resin is a copolymer obtained by at least copolymerizing a monomer having a styrene skeleton and a monomer having a (meth) acryloyl group.
Here, "(meth) acrylic acid" is an expression including both "acrylic acid" and "methacrylic acid". Further, the "(meth) acryloyl group" is an expression including both "acryloyl group" and "methacryloyl group".

Examples of the monomer having a styrene skeleton (hereinafter referred to as “styrene-based monomer”) include styrene and alkyl-substituted styrene (for example, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene). Examples thereof include methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, etc.), halogen-substituted styrene (for example, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, etc.), vinylnaphthalene and the like. The styrene-based monomer may be used alone or in combination of two or more.
Among these, as the styrene-based monomer, styrene is preferable in terms of ease of reaction, ease of control of the reaction, and availability.

Examples of the monomer having a (meth) acryloyl group (hereinafter, referred to as “(meth) acrylic monomer”) include (meth) acrylic acid and (meth) acrylic acid ester. Examples of the (meth) acrylic acid ester include (meth) acrylic acid alkyl ester (for example, (meth) acrylic acid n-methyl, (meth) acrylic acid n-ethyl, (meth) acrylic acid n-propyl, and (meth) acrylic acid ester. ) N-butyl acrylate, n-pentyl (meth) acrylate, n-hexyl acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, ( N-dodecyl acrylate, n-lauryl acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, isopropyl (meth) acrylate , (Meta) isobutyl acrylate, (meth) t-butyl acrylate, (meth) isopentyl acrylate, (meth) amyl acrylate, (meth) neopentyl acrylate, (meth) isohexyl acrylate, (meth) acrylate Isoheptyl, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, etc.), aryl (meth) acrylate (eg, (meth)) Phenyl acrylate, biphenyl (meth) acrylate, diphenylethyl (meth) acrylate, t-butylphenyl (meth) acrylate, tarphenyl (meth) acrylate, etc.), dimethylaminoethyl (meth) acrylate, (meth) ) Diethylaminoethyl acrylate, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, β-carboxyethyl (meth) acrylate, (meth) acrylamide and the like. The (meth) acrylic acid-based monomer may be used alone or in combination of two or more.

The copolymerization ratio (mass basis, styrene-based monomer / (meth) acrylic-based monomer) of the styrene-based monomer and the (meth) acrylic-based monomer is, for example, 85/15 to 70/30. That is good.

The styrene (meth) acrylic resin may have a crosslinked structure. By adopting a crosslinked structure, the molecular structure becomes stronger, and it is possible to suppress defects such as cracking and peeling of the toner image when stress such as heat is applied. The styrene (meth) acrylic resin having a crosslinked structure is, for example, crosslinked by at least copolymerizing a monomer having a styrene skeleton, a monomer having a (meth) acrylic acid skeleton, and a crosslinkable monomer. Things can be mentioned.

Examples of the crosslinkable monomer include a bifunctional or higher functional crosslinker.
Examples of the bifunctional cross-linking agent include divinylbenzene, divinylnaphthalene, and di (meth) acrylate compounds (for example, diethylene glycol di (meth) acrylate, methylenebis (meth) acrylamide, decanediol diacrylate, glycidyl (meth) acrylate, etc.). , Polyester type di (meth) acrylate, 2-([1'-methylpropylideneamino] carboxyamino) ethyl methacrylate and the like.
Examples of the polyfunctional cross-linking agent include tri (meth) acrylate compounds (for example, pentaerythritol tri (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc.) and tetra (meth) acrylate. Compounds (eg, tetramethylolmethanetetra (meth) acrylate, oligoester (meth) acrylate, etc.), 2,2-bis (4-methacryloxy, polyethoxyphenyl) propane, diallylphthalate, triallyl cyanurate, triallyl assocyanurate. , Triallyl isocyanurate, triallyl trimellitate, diallyl chlorendate and the like.

The copolymerization ratio of the crosslinkable monomer to all the monomers (mass basis, crosslinkable monomer / total monomer) is preferably, for example, 2/1000 to 30/1000.

The weight average molecular weight of the styrene (meth) acrylic resin is preferably 30,000 or more and 200,000 or less. This makes it possible to suppress defects such as cracks and peeling of the toner image when a load such as heat is applied.
The weight average molecular weight of the styrene (meth) acrylic resin is preferably 40,000 or more and 100,000 or less, and more preferably 50,000 or more and 80,000 or less.

Here, in the present specification, the weight average molecular weight and the number average molecular weight of the resin are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using a Tosoh GPC / HLC-8120GPC as a measuring device, a Tosoh column / TSKgel SuperHM-M (15 cm), and a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The content of the styrene (meth) acrylic resin is preferably 80% by mass or more and 95% by mass or less with respect to the toner particles. As a result, the domain of the release agent is likely to be unevenly distributed on the core portion side, the exposure of the release agent on the toner surface is suppressed, and good heat storage property is obtained. The content of the styrene (meth) acrylic resin is preferably 83% by mass or more and 90% by mass or less, and more preferably 85% by mass or more and 90% by mass or less.
When a styrene (meth) acrylic resin is applied as the resin of the shell layer, the content of the styrene (meth) acrylic resin means the total content of the core portion and the shell layer.

-Styrene (meth) acrylic modified polyester resin-
The styrene (meth) acrylic-modified polyester resin is a resin having a styrene (meth) acrylic segment and a polyester segment.

-Polyester segment The polyester segment is the main chain of a styrene (meth) acrylic-modified polyester resin, and is a segment obtained by polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol. In addition, polyvalent carboxylic acid and polyhydric alcohol are also referred to as "raw material monomer of polyester segment".

The polyvalent carboxylic acid, which is one of the raw material monomers of the polyester segment, has a non-aromatic carbon-carbon unsaturated bond and has carboxy groups at both ends thereof (for example, unsaturated aliphatic dicarboxylic acid and At least one selected from the group consisting of unsaturated alicyclic dicarboxylic acids) may be included.

Here, the non-aromatic carbon-carbon unsaturated bond portion is preferably a bond portion with the styrene (meth) acrylic segment in the styrene (meth) acrylic-modified polyester resin. In that case, the unsaturated bond becomes a saturated bond. By using a dicarboxylic acid having a non-aromatic carbon-carbon unsaturated bond and having carboxy groups at both ends thereof, a carbon-carbon unsaturated bond can be introduced into the main chain of the obtained polyester.

Examples of the dicarboxylic acid (unsaturated aliphatic dicarboxylic acid, unsaturated alicyclic dicarboxylic acid) having a non-aromatic carbon-carbon unsaturated bond and having carboxy groups at both ends thereof include fumaric acid and maleic acid. Unsaturated aliphatic dicarboxylic acid; An unsaturated alicyclic dicarboxylic acid such as tetrahydrophthalic acid can be mentioned. From the viewpoint of reactivity, the dicarboxylic acid is preferably fumaric acid, maleic acid, or tetrahydrophthalic acid, and more preferably fumaric acid.

The dicarboxylic acid having a non-aromatic carbon-carbon unsaturated bond and having carboxy groups at both ends thereof is preferably contained in the polyvalent carboxylic acid in an amount of more than 0 mol% and less than 20 mol%. It is more preferably contained in an amount of 5 mol% or more and 15 mol% or less, further preferably 1 mol% or more and 5 mol% or less, and even more preferably 1 mol% or more and 3 mol% or less.

Other polyvalent carboxylic acids include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, anhydrides of these polyvalent carboxylic acids, and alkyl of these polyvalent carboxylic acids. Esters and the like can be mentioned.
Among these, aromatic dicarboxylic acids and trivalent or higher polyvalent carboxylic acids are examples of other polyvalent carboxylic acids from the viewpoint of improving the storage stability of toner and the charge retention performance in a high temperature and high humidity environment. It is preferable to use these in combination.

Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid and the like, and terephthalic acid is preferable.
Examples of the aliphatic dicarboxylic acid include adipic acid, succinic acid, succinic acid having an alkyl group and an alkenyl group, and the like.
Examples of the alicyclic dicarboxylic acid include cyclohexanedicarboxylic acids and decalindicarboxylic acids.
Examples of the trivalent or higher valent carboxylic acid include trimellitic acid and pyromellitic acid, and trimellitic acid is preferable.

Here, examples of the polyvalent carboxylic acid include an anhydride of the polyvalent carboxylic acid, a lower (for example, 1 to 5 carbon atoms) alkyl ester of each polyvalent carboxylic acid, and the like.

Each polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol which is one of the raw material monomers of the polyester segment include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.) and alicyclic type. Examples thereof include diols (for example, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc.) and aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.). Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.

Here, the polyhydric alcohol may contain an alkylene oxide adduct of 2,2-bis (4-hydroxyphenyl) propane.

The alkylene oxide adduct of 2,2-bis (4-hydroxyphenyl) propane is preferably a compound represented by the following general formula (BPA). The alkylene oxide adduct means the entire structure in which an oxyalkylene group is added to 2,2-bis (4-hydroxyphenyl) propane.

In the general formula (BPA), R ¹ O and R ² O both represent an oxyalkylene group. Independently, R ¹ O and R ² O are preferably an oxyalkylene group having 1 or more and 4 or less carbon atoms, and preferably an oxyethylene group or an oxypropylene group.

x and y correspond to the number of moles of alkylene oxide added, and are positive numbers, respectively. Further, from the viewpoint of enhancing the reactivity with the polyvalent carboxylic acid, the average value of the sum of x and y is preferably 2 or more and 7 or less, more preferably 2 or more and 5 or less, and further preferably 2 or more and 3 or less.
The x R ¹ O or y R ² O may be the same or different, but both are preferably the same group, and both are more preferably oxypropylene groups.

Here, the content of the oxypropylene group is preferably 50 mol% or more and 100 mol% or less, more preferably 60 mol% or more and 100 mol% or less, and further preferably 70 mol% or more and 100 mol% or less among the oxyalkylene groups. , 100 mol% is particularly preferred.
As the oxyalkylene group other than the oxypropylene group, an oxyethylene group and an oxytrimethylene group are preferable, and an oxyethylene group is more preferable.

The alkylene oxide adduct of 2,2-bis (4-hydroxyphenyl) propane is preferably contained in the polyhydric alcohol in an amount of 40 mol% or more and 100 mol% or less, and preferably 60 mol% or more and 100 mol% or less. More preferably, it is further preferably contained in an amount of 80 mol% or more and 100 mol% or less, and particularly preferably 100 mol% or less.

Each polyhydric alcohol may be used alone or in combination of two or more.

The acid value of the polyester segment is preferably 5 mgKOH / g or more and 40 mgKOH / g or less, more preferably 5 mgKOH / g or more and 35 mgKOH / g or less, still more preferably 10 mgKOH / g or more and 30 mgKOH / g or less, and particularly. It is preferably 15 mgKOH / g or more and 25 mgKOH / g or less.
The acid value of the polyester segment is based on the "test method for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponified product of chemical products" specified in JIS-K0070 (1992). , Measured.

The number average molecular weight of the polyester segment is preferably 1,000 or more and 10,000 or less, and more preferably 1,500 or more and 5,000 or less.

The acid group of the polyester segment preferably contains 90 mol% or more of a carboxy group, and more preferably 100 mol%.

-Styrene (meth) acrylic segment The styrene (meth) acrylic segment constituting the styrene (meth) acrylic-modified polyester resin is addition-polymerized with an addition-polymerizable monomer containing a styrene-based monomer and a (meth) acrylic-based monomer. A segment containing an addition polymer. The styrene (meth) acrylic segment is a side chain in the styrene (meth) acrylic modified polyester resin.

Among the addition-polymerizable monomers, the styrene-based monomer and the (meth) acrylic-based monomer are the same as the styrene-based monomer and the (meth) acrylic-based monomer referred to in the above-mentioned styrene (meth) acrylic resin. Monomers are exemplified.
On the other hand, other monomers include olefins such as ethylene, propylene and butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as vinyl methyl ether; halogens such as vinylidene chloride. Vinylidene compound; N-vinyl compounds such as N-vinylpyrrolidone are exemplified.

-Ratio of each segment.
The mass ratio of the polyester segment to the styrene (meth) acrylic segment [styrene (meth) acrylic segment / polyester segment)] is preferably 5/95 or more and 30/70 or less, preferably 10/90 or more and 30/70 or less, and 10 More preferably, it is / 90 or more and 25/75 or less. Within the above range, the strength of the toner is increased, and the resistance to heat and its own weight when the recording medium is stacked in the discharge container called the finisher tray is improved. In addition, from the viewpoint of heat storage, it is easy to take a more uniform sea-island structure and suppress excessive exposure of the release agent to the surface of the toner particles.

Characteristics of Styrene (Meta) Acrylic Modified Polyester Resin The softening temperature of the styrene (meth) acrylic modified polyester resin is preferably 80 ° C. or higher and 140 ° C. or lower, and more preferably 95 ° C. or higher and 120 ° C. or lower.
The softening temperature is measured by the following method. Using a high-grade flow tester CFT-500 (manufactured by Shimadzu Corporation), the diameter of the pores of the die is 1 mm, the pressurizing load is 196 N (20 kg / cm ² ), the starting temperature is 60 ° C, and the heating rate is 6 ° C /. The softening temperature is determined as a temperature corresponding to 1/2 of the height from the outflow start point to the end point when a ^{1 cm 3} sample is melted and outflowed under the condition of minutes.

-Synthesis of styrene (meth) acrylic-modified polyester resin As a method for synthesizing styrene (meth) acrylic-modified polyester resin, for example, a polyester resin (polyester segment) is prepared by polymerization polymerization of polyvalent carboxylic acid and polyhydric alcohol. , A method of addition-polymerizing an addition-polymerizable monomer containing a styrene-based monomer and a (meth) acrylic-based monomer in the presence of a polyester segment is preferable.

Specifically, for example, a method in which a polyester resin (polyester segment) and an addition-polymerizable monomer are directly mixed and polymerized, and a method in which a polyester resin (polyester segment) and an addition-polymerizable monomer are dissolved in an organic solvent and polymerized. , A step of preparing a polyester resin (polyester segment) and mixing the polyester resin with an aqueous medium to obtain an aqueous dispersion of the polyester resin, and adding an addition polymerizable monomer to the aqueous dispersion and polymerizing the styrene ( Meta) Examples thereof include a method including a step of obtaining an acrylic-modified polyester resin.

-Content of styrene (meth) acrylic-modified polyester resin The content of the styrene (meth) acrylic-modified polyester resin is preferably 2% by mass or more and 8% by mass or less, preferably 4% by mass or more and 8% by mass or less, based on the toner particles. Hereinafter, it is more preferably 6% by mass or more and 8% by mass or less. Within the above range, the strength of the toner is increased, and the resistance to heat and its own weight when the recording medium is stacked in the discharge container called the finisher tray is improved. In addition, from the viewpoint of heat storage, it is easy to take a more uniform sea-island structure and suppress excessive exposure of the release agent to the surface of the toner particles.
When a styrene (meth) acrylic-modified polyester resin is applied as the resin of the shell layer, the content of the styrene (meth) acrylic-modified polyester resin means the total content of the core portion and the shell layer.

Here, the mass ratio of the styrene (meth) acrylic resin to the styrene (meth) acrylic-modified polyester resin (styrene (meth) acrylic resin / styrene (meth) acrylic-modified polyester resin) is 80/20 or more and 95/5 or less. Is preferable, 83/17 or more and 92/8 or less is more preferable, and 85/15 or more and 90/10 or less is further preferable. Within the above range, the strength of the toner is increased, and the resistance to heat and its own weight when the recording medium is stacked in the discharge container called the finisher tray is improved. In addition, from the viewpoint of heat storage, it is easy to obtain a more uniform sea-island structure, and excessive exposure of the release agent to the surface of the toner particles is suppressed.

-Other amorphous resin (A)-
Examples of the other amorphous resin (A) include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, methylacrylic acid, ethylacrylic acid, acrylic acid). n-propyl, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated Nitrives (eg acrylic nitrile, methacrylic nitrile, etc.), vinyl ethers (eg vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg ethylene, A vinyl-based resin composed of a homopolymer of a monomer such as propylene, butadiene, etc., or a copolymer obtained by combining two or more of these monomers (however, a vinyl-based resin excluding styrene (meth) acrylic resin) Can be mentioned.
As the other amorphous resin (A), examples of the binder resin include epoxy resin, polyester resin (polyester resin other than styrene (meth) acrylic-modified polyester resin), polyurethane resin, polyamide resin, cellulose resin, and poly. Examples thereof include non-vinyl resins such as ether resins and modified rosins, and mixtures of these with the vinyl resins.

-Crystalline resin-
The binder resin may contain a crystalline resin in addition to the amorphous resin (A).
As the crystalline resin, a crystalline polyester resin is preferable. Crystalline polyester does not show a clear glass transition temperature due to the arrangement of molecular chains and is difficult to soften to the melting temperature, but it melts rapidly near the glass transition temperature. It is possible to achieve both fixability.

-Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the crystalline polyester resin, a commercially available product may be used, or a synthetic resin may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic is preferable to a polymerizable monomer having an aromatic.

The "crystallinity" of the resin means that the resin has a clear endothermic peak rather than a stepwise endothermic change in differential scanning calorimetry (DSC). Specifically, the temperature rise rate is 10 (° C.). / Min) indicates that the half-value width of the endothermic peak is within 10 ° C. On the other hand, "amorphous" of the resin means that the half width exceeds 10 ° C., shows a stepwise endothermic amount change, or does not show a clear endothermic peak.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonandicarboxylic acid, and 1,10-decandicarboxylic acid. Acids, 1,12-dodecanedicarboxylic acids, 1,14-tetradecanedicarboxylic acids, 1,18-octadecanedicarboxylic acids, etc., aromatic dicarboxylic acids (eg, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Examples thereof include dibasic acids such as acids), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (for example, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.). Anhydrides or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof can be mentioned.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include an aliphatic diol (for example, a linear aliphatic diol having 7 or more and 20 or less carbon atoms in the main chain portion). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-. Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples thereof include octadecanediol and 1,14-eicosanedecanediol. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable.
As the polyhydric alcohol, a trihydric or higher alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
The polyhydric alcohol may be used alone or in combination of two or more.

Here, the polyhydric alcohol preferably has an aliphatic diol content of 80 mol% or more, preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 55 ° C. or higher and 90 ° C. or lower, and further preferably 60 ° C. or higher and 85 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperature of plastics".

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

The crystalline polyester resin is obtained by a well-known production method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the raw material. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility, the monomer, and the acid or alcohol to be polycondensed are condensed in advance, and then weighted together with the main component. It is good to condense.

The content of the crystalline polyester resin is preferably 10% by mass or more and 30% by mass or less, more preferably 15% by mass or more and 25% by mass or less, and further preferably 18% by mass or more and 23% by mass or less with respect to the total binder resin. .. As a result, the binder becomes a sharp melt of the toner as compared with the case where the binder resin contains the amorphous resin alone, the melting temperature of the toner is lowered, and the fixability is improved.

-Colorant-
Examples of colorants include carbon black, chrome yellow, Hansa yellow, benzine yellow, slene yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmin 6B, Dupont Oil Red, Pyrazolon Red, Resole Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultra Marine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malakite green oxalate, or aclysine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black Examples thereof include various dyes such as system, polymethine type, triphenylmethane type, diphenylmethane type and thiazole type.
One type of colorant may be used alone, or two or more types may be used in combination.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. Further, a plurality of kinds of colorants may be used in combination.

The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Other additives-
Examples of other additives include well-known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

(Shell layer)
The shell layer contains at least a non-crystalline resin (B) and a mold release agent containing a hydrocarbon wax.

-Bundling resin-
As the binder resin, a well-known non-crystalline resin (B) is applied.
Examples of the non-crystalline resin (B) include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, methyl acrylate, ethyl acrylate, n-acrylic acid, etc.). Propyl, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (For example, acrylonitrile, methacrylic acid, etc.), vinyl ethers (for example, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (for example, ethylene, propylene, etc.) Examples thereof include homopolymers of monomers such as butadiene) and vinyl-based resins composed of copolymers in which two or more of these monomers are combined.
Examples of the well-known non-crystalline resin (B) include non-vinyl resins such as epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, and modified rosin, and these and the vinyl resin. Examples thereof include a mixture or a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence of these.
As the non-crystalline resin (B), a styrene (meth) acrylic-modified polyester resin may be applied.
These non-crystalline resins (B) may be used alone or in combination of two or more.

Among these, as the amorphous resin (B) contained in the shell layer, a styrene (meth) acrylic resin and an amorphous polyester resin are preferable.

-Release agent-
At least a hydrocarbon wax is applied as the release agent.
The hydrocarbon-based wax is a wax having a hydrocarbon as a skeleton. Wax having), microcrystallin wax and the like. Of these, paraffin wax is more preferable from the viewpoint of fixability. Further, the wax may contain a plurality of types of hydrocarbon-based waxes in the toner particles.
Hydrocarbon waxes are not limited to this. Further, these hydrocarbon waxes may be used alone or in combination of two or more.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K 7121-1987 "Method for measuring transition temperature of plastics". ..

Here, the release agent has one or more endothermic peaks obtained in the second heating process by the differential scanning calorimeter (DSC) in the range of 60 ° C. or higher and 100 ° C. or lower (preferably 65 ° C. or higher and 90 or lower). It is preferably a release agent. A mold release agent having an endothermic peak only in the range of less than 60 ° C. or in the range of more than 100 ° C. tends to deteriorate the exudability of the mold release agent, and the toner fixability and heat storage property tend to deteriorate.
Here, having one or more endothermic peaks of the release agent within the above temperature range means that the endothermic peak temperature of the release agent (the apex temperature of the endothermic peak) has one or more within the above temperature range. .. Hereinafter, the endothermic peak temperature of this release agent will be referred to as "the 2nd endothermic peak temperature of the release agent".

The measurement of the 2nd endothermic peak temperature of the release agent is carried out in accordance with ASTMD3418-8.
Specifically, 10 mg of toner particles to be measured (or toner particles externally added with an external additive) are set in a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-60 type) equipped with an automatic tangential processing system. It is heated from room temperature (25 ° C.) to 150 ° C. at a heating rate of 10 ° C./min (first heating process), and cooled to 0 ° C. at a temperature lowering rate of −10 ° C./min.
Next, the heating is performed again from 0 ° C. to 150 ° C. at a heating rate of 10 ° C./min (second heating process) to obtain a DSC curve.
It is held at 0 ° C. and 150 ° C. for 10 minutes each.

From the DSC curve obtained in the second temperature rise process, the 2nd endothermic peak temperature from which the release agent is derived is specified. To specify the endothermic peak temperature derived from the release agent, first, the toner is dissolved in toluene heated to 180 ° C., and then only the crystallized release agent is separated by cooling. The obtained mold release agent is heated twice by a differential scanning calorimeter in the same manner as described above, and the endothermic peak temperature in the second temperature raising process is obtained. At this time, if the endothermic peak of the toner particles and the endothermic peak of only the release agent match, it is determined that the toner particles are derived from the release agent.

As a release agent having at least one heat absorption peak obtained in the second heating process by the differential scanning calorimeter (DSC) in the range of 70 ° C. or higher and 100 ° C. or lower, low molecular weight polyethylene wax, low molecular weight polypropylene wax, and micro Examples thereof include hydrocarbon waxes such as crystallin wax and paraffin wax.

As for the release agent, 70% or more of the total release agent is present within 1000 nm from the surface of the toner particles. (Hereinafter, the abundance ratio of the release agent present within 1000 nm from the surface of the toner particles is also referred to as "presence rate of the release agent").
The abundance rate of the release agent is 70% or more, but at the time of fixing, the release agent easily exudes from the toner particles in a state closer to uniform, and in order to effectively suppress the set-off of the fixed image, it is necessary. 80% or more is preferable. The upper limit of the abundance rate of the release agent is preferably 100%.

The average diameter of the domain of the release agent (hereinafter, also referred to as “domain diameter”) is 0.3 μm or more and 1.2 μm or less, preferably 0.3 μm or more and 1.0 μm or less, and 0.3 μm or more and 0.7 μm or less. More preferred. As a result, the release agent is likely to seep out from the toner particles in a more uniform state at the time of fixing, and it is possible to effectively suppress the set-off of the fixed image.

Here, a method for measuring the abundance of the release agent and the domain diameter (average diameter of the domain) of the release agent will be described.

Samples and images for measurement are prepared by the following methods.
Toner is mixed with epoxy resin and embedded to solidify the epoxy resin. The obtained solidified product is cut by an ultramicrotome device (UltracutUCT manufactured by Leica) to prepare a flaky sample having a thickness of 80 nm or more and 130 nm or less. Next, the obtained flaky sample is stained with ruthenium tetroxide in a desiccator at 30 ° C. for 3 hours. Then, an SEM image of the stained flaky sample is obtained with an ultra-high resolution field emission scanning electron microscope (FE-SEM. S-4800 manufactured by Hitachi High-Technologies Co., Ltd.). Since the release agent, the styrene (meth) acrylic resin, and the polyester resin are easily dyed with ruthenium tetroxide in this order, each component is identified by the shade depending on the degree of dyeing. If it is difficult to distinguish the shade due to the condition of the sample, adjust the staining time.
In the cross section of the toner particles, the domain of the colorant is smaller than the domain of the release agent, so that it can be distinguished by the size. In addition, the domain of the colorant can be distinguished by the shade of dyeing with the domain of the release agent and the domain of the styrene (meth) acrylic resin.

The abundance of the release agent is a value measured by the following method.
In the SEM image, a toner particle cross section having a maximum length of 85% or more of the volume average particle diameter of the toner particles is selected, the domain of the dyed release agent is observed, and the area of the release agent of the entire toner particles is used. , The area of the release agent existing in the region within 1000 nm from the surface of the toner particles is obtained, and the ratio of the two areas (the area of the release agent existing in the region within 1000 nm from the surface of the toner particles / the separation of the entire toner particles). (Area of mold) is calculated. Then, this calculation is performed for 100 toner particles, and the average value thereof is taken as the abundance rate of the release agent.
The reason for selecting a toner particle cross section having a maximum length of 85% or more of the volume average particle size of the toner particles is that a cross section having a volume average particle size of less than 85% is expected to be a cross section of the toner particle end, and the toner particle end. This is because the state of the domain in the toner particles is not well reflected in the cross section of.

The domain diameter (average diameter of the domain) of the release agent is a value measured by the following method.
In the SEM image, 30 toner particle cross sections having a maximum length of 85% or more of the volume average particle diameter of the toner particles are selected, and a total of 100 stained release agent domains are observed. The maximum length of each domain is measured, the maximum length is defined as the diameter of the domain, and the arithmetic mean thereof is defined as the average diameter.

Examples of the control method for setting the abundance rate of the release agent to 70% or more include a method in which the release agent is used only when forming the shell layer in the production of toner particles.

For the average diameter of the release agent domain, for example, the volume average particle diameter of the release agent particles contained in the release agent particle dispersion liquid used in the production by producing the toner particles by the aggregation and coalescence method is adjusted. It can be controlled by preparing a plurality of release agent particle dispersions having different volume average particle diameters and using them in combination; etc.

On the other hand, the exposure rate of the release agent (exposure rate of the release agent on the surface of the toner particles) is preferably 1% or more and 6% or less, more preferably 1% or more and 5% or less, and further preferably 1% or more and 4% or less. preferable. This prevents the toner particles from fusing together under high temperature and high humidity, and makes it easy to obtain good heat storage properties.

Here, the exposure rate of the release agent is a value obtained by XPS (X-ray photoelectron spectroscopy) measurement. As the XPS measuring device, JPS-9000MX manufactured by JEOL Ltd. is used, and for the measurement, MgKα ray is used as the X-ray source, the acceleration voltage is 10 kV, and the emission current is 30 mA. Here, the amount of mold release agent on the toner surface is quantified by the peak separation method of the C1S spectrum. In the peak separation method, the measured C1S spectrum is separated into each component by using curve fitting by the least squares method. Of the separated peaks, the exposure rate is calculated from the peak area and composition ratio derived from the release agent. For the component spectrum that is the base of separation, the C1S spectrum obtained by independently measuring the release agent and the binder resin used for producing the toner particles is used.
When the toner particles to be measured are external toner, ultrasonic treatment is performed for 20 minutes together with a mixed solution of ion-exchanged water and a surfactant to remove the external additive, and the surfactant is removed and the toner particles are removed. Measurements are taken after drying and recovery. The removal treatment of the external additive can be repeated until the external additive is removed.

The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Thickness of shell layer-
The thickness of the shell layer is preferably 0.2 μm or more and 4 μm or less, and more preferably 0.3 μm or more and 3 μm or less.
The thickness of the shell layer is measured by the following method. Thin sections are prepared by embedding toner particles in epoxy resin or the like and cutting them with a diamond knife or the like. This thin section is observed with a transmission electron microscope (TEM) or the like, and cross-sectional images of a plurality of toner particles are taken. The thickness of the shell layer is measured at 20 points from the cross-sectional image of the toner particles, and the average value is adopted. When it is difficult to observe the shell layer in the cross-sectional image, it is possible to facilitate the measurement by observing the shell layer by staining.

(Other components of toner particles)
The toner particles may contain a metal having a divalent ionic valence. The metal may contain at least magnesium. This metal is a component contained in both the core portion and the shell portion of the toner particles.

It is considered that the "metal having a divalent ionic valence" contained in the toner particles exists as a metal ion. Then, the metal ion forms an ionic bond inside the toner particle (in the case of a divalent metal ion, an ionic crosslink is formed). For example, as the binder resin, the carboxyl group or hydroxyl group of the styrene (meth) acrylic resin and the styrene (meth) acrylic-modified polyester resin interacts with the metal ion to form an ion crosslink. This ion cross-linking increases the viscoelasticity of the toner and strengthens the toner strength. In general, the larger the ionic valence, the easier it is to form ion bridges, and the more viscoelastic the toner tends to be. Therefore, in the case of trivalent or higher metal ions, the toner image is higher than that of divalent metal ions. When fixing the toner particles, the toner particles tend to be difficult to dissolve in a state close to uniform on the recording medium, which is disadvantageous for low temperature fixability. However, in the case of monovalent ions, it is difficult to form ion crosslinks, and the toner strength is insufficient. Therefore, from the viewpoint of low-temperature fixability and suppression of image set-off, it is preferable that the toner particles contain a metal having a divalent ionic valence.

Specific examples of the metal having a divalent ionic valence include metals such as magnesium, zinc, calcium and copper.

Examples of the metal supply source (compound to be contained in the toner particles as an additive) include metal salts, inorganic metal salt polymers, metal complexes and the like. The metal salt, the inorganic metal salt polymer, and the metal complex are added to the toner particles as a coagulant, for example, when the toner particles are produced by the coagulation-union method.
Examples of the metal salt include magnesium chloride, magnesium sulfate, iron (II) chloride, zinc chloride, calcium chloride, calcium sulfate and the like.
Examples of the inorganic metal salt polymer include polyiron sulfate (II) and calcium polysulfide.
Examples of the metal complex include a metal salt of an aminocarboxylic acid. Specific examples of the metal complex include known chelate-based metal salts such as ethylenediaminetetraacetic acid, propanediaminetetraacetic acid, nitrile triacetic acid, triethylenetetramine 6 acetic acid, and diethylenetriamine pentaacetic acid (eg, calcium salt, etc.). Magnesium salt) and the like.

The source of these metals may be added as a mere additive, not as a coagulant.

The content of the metal capable of having a divalent ionic valence is preferably 0.002% by mass or more and 0.4% by mass or less with respect to the entire toner particles from the viewpoint of easiness of forming an ionic bridge, and is 0.01. More preferably, it is by mass% or more and 0.3% by mass or less.

The content of the metal (metal ion) that can have a divalent ion valence is quantitatively analyzed by the fluorescent X-ray intensity (fluorescent X-ray analyzer (scanning fluorescent X-ray analyzer, ZSX PrimusII)) of the powder particles. Measured by Specifically, for example, first, a resin and a metal source are mixed to obtain a resin mixture having a known metal (metal ion) concentration. A pellet sample of 200 mg of this resin mixture is obtained using a tablet molding machine having a diameter of 13 mm. The mass of this pellet sample is precisely weighed, and the fluorescence X-ray intensity of the pellet sample is measured to obtain the peak intensity. Similarly, the pellet sample in which the amount of the metal source added is changed is also measured, and a calibration curve is prepared from these results. When the toner particles to be measured are external toner, ultrasonic treatment is performed for 20 minutes together with a mixed solution of ion-exchanged water and a surfactant to remove the external additive, and the surfactant is removed and the toner particles are removed. Measurements are taken after drying and recovery. The removal treatment of the external additive can be repeated until the external additive is removed. Then, using the calibration curve, the content of "metal (metal ion) having a divalent ionic valence" of the toner particles to be measured is quantitatively analyzed.

Examples of the method for adjusting the content of the metal having a divalent ionic valence include 1) adjusting the amount of the metal source added, and 2) agglomeration when the toner particles are produced by the agglomeration and coalescence method. In the process, after adding a flocculant (eg, a metal salt or metal salt polymer) as a metal source, at the end of the flocculation step, a chelating agent (eg, EDTA (ethylenediamine tetraacetic acid), DTPA (diethylenetriamine pentaacetic acid), NTA (Nitrilotriacetic acid) etc.) is added to form a complex with the metal with a chelating agent, and the complex salt formed in the subsequent washing step or the like is removed to adjust the metal content.

-Characteristics of toner particles, etc.-
The volume average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

The various average particle sizes and various particle size distribution indexes of the toner particles were measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution was measured using ISOTON-II (manufactured by Beckman Coulter). Toner.
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm or more and 60 μm or less is obtained by using a Coulter Multisizer II with an aperture of 100 μm. Measure. The number of particles to be sampled is 50,000.
Cumulative distribution of volume and number is drawn from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the cumulative 16% particle size is volume particle size D16v and number particle size. The particle size having D16p and a cumulative 50% is defined as the volume average particle size D50v and the cumulative number average particle size D50p, and the particle size having a cumulative number of 84% is defined as the volume particle size D84v and the number particle size D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 , and the number particle size distribution index (GSDp) is calculated as ^{(D84p / D16p) 1/2.}

The average circularity of the toner particles is preferably 0.94 or more and 1.00 or less, and more preferably 0.95 or more and 0.98 or less.

The average circularity of the toner particles is obtained by (perimeter equivalent to a circle) / (perimeter) [(perimeter of a circle having the same projected area as the particle image) / (perimeter of the projected particle image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Cysmex) that captures a particle image as a still image by sucking and collecting toner particles to be measured, forming a flat flow, and instantly causing strobe light emission to analyze the particle image. Obtained by FPIA-3000) manufactured by the company. Then, the number of samplings when calculating the average circularity is set to 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed. ..

[External agent]
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, 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 inorganic particles as an external additive should be hydrophobized. The hydrophobizing treatment is performed, for example, by immersing inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

Examples of the resin particles of the external additive include resin particles such as polystyrene, polymethylmethacrylate (PMMA), and melamine resin.
Examples of the cleaning activator for the external additive include metal salts of higher fatty acids typified by zinc stearate, particles of fluorine-based high molecular weight substances, and the like.

The amount of the external additive added is preferably, for example, 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2.0% by mass or less with respect to the toner particles.

[Toner manufacturing method]
Next, a method for producing toner according to this embodiment will be described.
The toner according to the present embodiment can be obtained by externally adding an external additive to the toner particles after producing the toner particles.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method, etc.) and a wet production method (for example, an agglomeration coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The method for producing the toner particles is not particularly limited to these production methods, and a well-known production method is adopted.
Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

Specifically, for example, when the toner particles are produced by the aggregation and coalescence method,
A step of preparing a resin particle dispersion for the core in which resin particles for the core, which is a binding resin for the core, are dispersed (a resin particle dispersion preparation step for the core);
A step of preparing a resin particle dispersion for the shell layer in which resin particles for the shell layer, which is a binding resin for the shell layer, are dispersed (a resin particle dispersion preparation step for the shell layer), and a step of preparing the resin particle dispersion for the shell layer.
A step of preparing a release agent particle dispersion liquid in which mold release agent particles are dispersed (a step of preparing a release agent particle dispersion liquid);
Aggregate the resin particles for the core part (and other particles if necessary) in the resin particle dispersion liquid for the core part (in the dispersion liquid mixed with other particle dispersion liquid such as a colorant if necessary). And the step of forming the first agglomerated particles (first agglomerated particle forming step);
The first agglomerated particle dispersion liquid in which the first agglomerated particles are dispersed, the resin particle dispersion liquid for the shell layer, and the release agent particle dispersion liquid are mixed, and the resin particles for the shell layer and the release on the surface of the first agglomerated particles. A step of forming second agglomerated particles by aggregating the mold particles so as to adhere to them (second agglomerated particle forming step)
A step of heating the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed and fusing and coalescing the second agglomerated particles to form toner particles (fusion and coalescence step);
Toner particles are manufactured through the above.

Hereinafter, details of each step of the aggregation and coalescence method will be described. In the following description, a method for obtaining toner particles containing a colorant will be described, but the colorant is used as needed. Of course, other additives other than the colorant may be used.

-Dispersion preparation process-
First, a resin particle dispersion for the core (styrene (meth) acrylic resin particle dispersion, styrene (meth) acrylic-modified polyester resin particle dispersion), a resin particle dispersion for the shell layer, a colorant particle dispersion, and a mold release agent. Prepare a particle dispersion.
Hereinafter, each resin particle dispersion liquid in which each resin particle is dispersed will be referred to as a “resin particle dispersion liquid” and will be described.

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

Examples of the dispersion medium used in the resin particle dispersion liquid include an aqueous medium.
Examples of the aqueous medium include distilled water, water such as ion-exchanged water; alcohols; and the like. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Non-ionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols; and the like. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
One type of surfactant may be used alone, or two or more types may be used in combination.

Examples of the method for dispersing the resin particles in the dispersion medium include a general dispersion method using a rotary shear homogenizer, a ball mill having a medium, a sand mill, a dyno mill, and the like. Alternatively, the resin particles may be dispersed in the dispersion medium by a phase inversion emulsification method. In the phase inversion emulsification method, the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, neutralized by adding a base to the organic continuous phase (O phase), and then water (W phase). This is a method in which the phase is changed from W / O to O / W by charging the resin, and the resin is dispersed in the aqueous medium in the form of particles.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and further preferably 0.1 μm or more and 0.6 μm or less. ..
The volume average particle size of the resin particles is the volume with respect to the divided particle size range (channel) using the particle size distribution obtained by the measurement of a laser diffraction type particle size distribution measuring device (for example, manufactured by Horiba Seisakusho, LA-700). The cumulative distribution is drawn from the small particle size side, and the particle size that is 50% of the total particle size is defined as the volume average particle size D50v. The volume average particle diameter of the particles in the other dispersion is also measured in the same manner.

The content of the resin particles contained in the resin particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

A colorant dispersion and a release agent particle dispersion are also prepared in the same manner as the resin particle dispersion. That is, the dispersion medium, the dispersion method, the volume average particle size of the particles, and the content of the particles in the resin particle dispersion are the same in the colorant dispersion and the release agent particle dispersion.

-First agglomerated particle forming step-
Next, the resin particle dispersion liquid for the core portion and the colorant dispersion liquid are mixed.
Then, in the mixed dispersion, the core resin particles (styrene (meth) acrylic resin particles and styrene (meth) acrylic-modified polyester resin particles) and the colorant particles are hetero-aggregated to have a target diameter. The first agglomerated particles containing the resin particles for the part and the colorant particles are formed.
If necessary, a release agent particle dispersion liquid may also be mixed, and the release agent particles may be contained in the first agglomerated particles.

Specifically, for example, a flocculant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to acidic (for example, pH 2 or more and 5 or less), a dispersion stabilizer is added as necessary, and then the core portion is used. Heat to a temperature close to the glass transition temperature of the resin particles for glass (specifically, for example, -30 ° C or higher of the glass transition temperature of the core resin and -10 ° C or lower of the glass transition temperature) and disperse in the mixed dispersion. The agglomerated particles are aggregated to form a first agglomerated particle.
In the first agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear homogenizer, a flocculant is added at room temperature (for example, 25 ° C.), and the pH of the mixed dispersion is acidic (for example, pH 2 or more and 5 or less). And if necessary, a dispersion stabilizer may be added, and then heating may be performed.

As the flocculant, for example, a surfactant having the opposite polarity to the surfactant used as the dispersant added to the mixed dispersion, an inorganic metal salt, a metal complex, or the like is used. 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.
When an inorganic metal salt, a metal complex, or the like is used as the aggregating agent, an additive that forms a complex or a similar bond with the metal (metal ion) of the aggregating agent is added after the aggregation is completed. As this additive, a chelating agent is preferably used. By adding this chelating agent, the flocculant is removed from the core portion to be formed, and the metal concentration in the core portion of the toner particles to be formed is adjusted.

Here, the metal salt, the metal salt polymer, and the metal complex as the flocculant are used as a metal supply source. These examples are as described above.

As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid and gluconic acid, iminodic acid (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA).
The amount of the chelating agent added is, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

-Second aggregate particle formation step-
After obtaining the first agglomerated particle dispersion liquid in which the first agglomerated particles are dispersed, the first agglomerated particle dispersion liquid, the resin particle dispersion liquid for the shell layer, and the release agent particle dispersion liquid are further mixed. The resin particle dispersion liquid for the shell layer and the release agent particle dispersion liquid may be mixed in advance, and this mixed liquid may be mixed with the first agglomerated particle dispersion liquid.

Then, in the mixed dispersion, the second agglomerated particles having a diameter close to the target toner particle size are hetero-aggregated so that the resin particles for the shell layer and the release agent particles adhere to the surface of the first agglomerated particles. Form.

Specifically, for example, in the first agglomerated particle forming step, when the first agglomerated particles reach the target particle size, the resin particles for the shell layer and the release agent particles are added to the first agglomerated particle dispersion liquid. The dispersion liquid in which the particles are dispersed is mixed. Next, the mixed dispersion is heated below the glass transition temperature of the resin particles for the shell layer, the pH of the mixed dispersion is adjusted to, for example, 6.5 or more and 8.5 or less, and the progress of aggregation is stopped. ..

As a result, the second agglomerated particles that are agglomerated so that the resin particles for the shell layer and the release agent particles adhere to the surface of the first agglomerated particles can be obtained.

-Fusion / unification process-
Next, the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed is, for example, a temperature equal to or higher than the glass transition temperature of the shell layer resin (for example, 10 ° C. to 50 ° C. higher than the glass transition temperature of the shell layer resin). ) To fuse and coalesce the second agglomerated particles to form toner particles.

Toner particles are obtained through the above steps.
After obtaining the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed, the second agglomerated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles to be the binding resin are dispersed are further mixed. Then, the step of forming the third agglomerated particles by further aggregating the resin particles so as to adhere to the surface of the second agglomerated particles, and heating the third agglomerated particle dispersion liquid in which the third agglomerated particles are dispersed. Then, the toner particles may be produced through the steps of fusing and coalescing the third agglomerated particles to form the toner particles.

After completion of the fusion / coalescence step, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain a dried toner particle.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning 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 may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, air-flow drying, fluid drying, vibration-type fluid drying and the like may be performed.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive to the toner particles in a dry state and mixing them. The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like. Further, if necessary, coarse particles of toner may be removed by using a vibrating master separator, a wind sieving machine, or the like.

<Static charge image developer>
The electrostatic charge image developer according to the present embodiment contains at least the toner according to the present embodiment.
The electrostatic charge image developer according to the present embodiment may be a one-component developer containing only the toner according to the present embodiment, or a two-component developer mixed with the toner and a carrier.

The carrier is not particularly limited, and examples thereof include known carriers. As the carrier, for example, a coating carrier in which the surface of a core material made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; Resin-impregnated carrier; etc.
The magnetic powder dispersion type carrier and the resin impregnated type carrier may be carriers in which the constituent particles of the carrier are used as a core material and coated with a coating resin.

Examples of the magnetic powder include magnetic metals such as iron, nickel and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylic acid ester. Examples thereof include a copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polypropylene, a phenol resin, an epoxy resin and the like.
The coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include metals such as gold, silver and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating resin and, if necessary, a coating layer forming solution in which various additives are dissolved in an appropriate solvent and the like can be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include a dipping method in which the core material is immersed in a coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the core material surface, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and a solvent is removed.

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

<Image forming device / Image forming method>
The image forming apparatus / image forming method according to the present embodiment will be described.
The image forming apparatus according to the present embodiment includes an image holder, a charging means for charging the surface of the image holder, a static charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge. A developing means that accommodates an image developer and develops an electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer, and a recording medium that records the toner image formed on the surface of the image holder. It is provided with a transfer means for transferring to the surface of the recording medium and a fixing means for fixing the toner image transferred to the surface of the recording medium. Then, as the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

In the image forming apparatus according to the present embodiment, a charging step of charging the surface of the image holder, a static charge image forming step of forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge according to the present embodiment. A development step of developing an electrostatic charge image formed on the surface of an image holder as a toner image with an image developer, and a transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium. An image forming method (image forming method according to the present embodiment) having a fixing step of fixing a toner image transferred to the surface of a recording medium is carried out.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image holder to the recording medium; the toner image formed on the surface of the image holder is transferred to the intermediate transfer body. An intermediate transfer type device that first transfers the toner image to the surface and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium; after transferring the toner image, cleans the surface of the image holder before charging. A device provided with a cleaning means; a well-known image forming device such as a device provided with a static elimination means for irradiating the surface of an image holder with static elimination light after transfer of a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer means is, for example, an intermediate transfer body in which a toner image is transferred to the surface and a primary transfer in which a toner image formed on the surface of an image holder is primarily transferred to the surface of the intermediate transfer body. A configuration comprising means and secondary transfer means for secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium is applied.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) that is attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge including a developing means containing the electrostatic charge image developer according to the present embodiment is preferably used.

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

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is an electrophotographic first to output images of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. A fourth image forming unit 10Y, 10M, 10C, 10K (image forming means) is provided. These image forming units (hereinafter, may be simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

An intermediate transfer belt 20 as an intermediate transfer body is extended through each unit above the drawings of each unit 10Y, 10M, 10C, and 10K. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 arranged apart from each other from the left to the right in the drawing and a support roll 24 in contact with the inner surface of the intermediate transfer belt 20, and the first unit 10Y to the fourth unit 10Y to the fourth. It is designed to run in the direction toward the unit 10K. A force is applied to the support roll 24 in a direction away from the drive roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the support roll 24. Further, an intermediate transfer body cleaning device 30 is provided on the side surface of the image holder of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, the developing devices (development means) 4Y, 4M, 4C, and 4K of each unit 10Y, 10M, 10C, and 10K have yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K, respectively. Toner containing the four colors of toner is supplied.

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit forming a yellow image arranged on the upstream side in the traveling direction of the intermediate transfer belt. 10Y will be described as a representative. The second to fourth units are provided with reference numerals having magenta (M), cyan (C), and black (K) instead of yellow (Y) in the portion equivalent to the first unit 10Y. The description of the units 10M, 10C, and 10K of the above is omitted.

The first unit 10Y has a photoconductor 1Y that acts as an image holder. Around the photoconductor 1Y, a charging roll (an example of charging means) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and a laser beam 3Y based on a color-separated image signal expose the charged surface. An exposure device (an example of a static charge image forming means) 3 for forming an electrostatic charge image, and a developing device (an example of a developing means) 4Y for developing a static charge image by supplying a charged toner to the static charge image. A primary transfer roll 5Y (an example of a primary transfer means) that transfers a toner image onto an intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning means) 6Y that removes toner remaining on the surface of the photoconductor 1Y after the primary transfer. Are arranged in order.
The primary transfer roll 5Y is arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoconductor 1Y. Further, a bias power supply (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power supply changes the transfer bias applied to each primary transfer roll by control by a control unit (not shown).

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

The electrostatic charge image is an image formed on the surface of the photoconductor 1Y by charging. The laser beam 3Y reduces the specific resistance of the irradiated portion of the photosensitive layer, and the charged charge on the surface of the photoconductor 1Y flows. On the other hand, it is a so-called negative latent image formed by the residual charge of the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoconductor 1Y is rotated to a predetermined development position as the photoconductor 1Y travels. Then, at this developing position, the electrostatic charge image on the photoconductor 1Y is converted into a visible image (developed image) as a toner image by the developing device 4Y.

In the developing apparatus 4Y, for example, a static charge image developing agent containing at least yellow toner and a carrier is housed. The yellow toner is triboelectrically charged by being agitated inside the developing apparatus 4Y, and has a charge having the same polarity (negative electrode property) as the charged charge on the photoconductor 1Y, and is a developer roll (developing agent holder). Example) It is held on. Then, as the surface of the photoconductor 1Y passes through the developing device 4Y, the yellow toner is electrostatically adhered to the statically eliminated latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. .. The photoconductor 1Y on which the yellow toner image is formed is continuously traveled at a predetermined speed, and the toner image developed on the photoconductor 1Y is conveyed to a predetermined primary transfer position.

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

Further, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
In this way, the intermediate transfer belt 20 to which the yellow toner image is transferred in the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of each color are superimposed and multiple transferred. Toner.

The intermediate transfer belt 20 on which four color toner images are multiplex-transferred through the first to fourth units is arranged on the image holding surface side of the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt, and the intermediate transfer belt 20. It leads to a secondary transfer unit composed of the secondary transfer roll (an example of the secondary transfer means) 26. On the other hand, the recording paper (an example of the recording medium) P is fed through the supply mechanism into the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact with each other at a predetermined timing, and the secondary transfer bias is supported by the support roll. It is applied to 24. The transfer bias applied at this time is (-) polarity, which is the same polarity as the toner polarity (-), and the electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied on the intermediate transfer belt 20. The toner image of is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by the resistance detecting means (not shown) for detecting the resistance of the secondary transfer unit, and is voltage controlled.

After that, the recording paper P is sent to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (an example of the fixing means) 28, and the toner image is fixed on the recording paper P to form the fixing image.

Examples of the recording paper P for transferring the toner image include plain paper used in electrophotographic copiers, printers, and the like. Examples of the recording medium include an OHP sheet and the like in addition to the recording paper P.
In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is also preferably smooth, and for example, coated paper in which the surface of plain paper is coated with resin or the like, art paper for printing, or the like is preferably used. Will be done.

The recording paper P for which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.

<Process Cartridge / Toner Cartridge>
The process cartridge according to this embodiment will be described.
The process cartridge according to the present embodiment contains the electrostatic charge image developer according to the present embodiment, and is a developing means for developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developer. It is a process cartridge that is attached to and detached from the image forming apparatus.

The process cartridge according to the present embodiment is not limited to the above configuration, and includes a developing device and other means such as an image holder, a charging means, an electrostatic charge image forming means, and a transfer means, if necessary. It may be configured to include at least one selected from.

Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited to this. The main parts shown in the figure will be described, and the other parts will be omitted.

FIG. 2 is a schematic configuration diagram showing a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 2 is provided around the photoconductor 107 (an example of an image holder) and the photoconductor 107 by, for example, a housing 117 provided with a mounting rail 116 and an opening 118 for exposure. The charged roll 108 (an example of the charging means), the developing device 111 (an example of the developing means), and the photoconductor cleaning device 113 (an example of the cleaning means) are integrally combined and held and configured to form a cartridge. There is.
In FIG. 2, 109 is an exposure device (an example of an electrostatic charge image forming means), 112 is a transfer device (an example of a transfer means), 115 is a fixing device (an example of a fixing means), and 300 is a recording paper (an example of a recording medium). An example) is shown.

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present embodiment is a toner cartridge that houses the toner according to the present embodiment and is attached to and detached from the image forming apparatus. The toner cartridge accommodates a replenishing toner for supplying to the developing means provided in the image forming apparatus.

The image forming apparatus shown in FIG. 1 is an image forming apparatus having a structure in which the toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing apparatus 4Y, 4M, 4C, and 4K are each developing apparatus (color). ) Is connected to a toner cartridge (not shown). When the amount of toner contained in the toner cartridge is low, the toner cartridge is replaced.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited to the following Examples. Unless otherwise specified, "parts" and "%" are based on mass.

<Preparation of styrene (meth) acrylic resin particle dispersion>
[Preparation of styrene acrylic resin particle dispersion (StAc1)]
-Styrene: 77 parts-n-butyl acrylate: 23 parts-1,10-decanediol diacrylate: 0.4 parts-Dodecanthiol: 0.7 parts Anionic surfactant in a mixture of the above materials. (Dowfax manufactured by Dow Chemical Co., Ltd.) A solution prepared by dissolving 1.0 part in 60 parts of ion-exchanged water was added and dispersed and emulsified in a flask to prepare a monomer emulsion.
Subsequently, 2.0 parts of an anionic surfactant (Dowfax manufactured by Dow Chemical Co., Ltd.) was dissolved in 90 parts of ion-exchanged water, 2.0 parts of the emulsion of the monomer was added thereto, and ammonium persulfate was further added. 10 parts of ion-exchanged water in which 1.0 part was dissolved was added.
Then, the rest of the emulsion of the monomer was added over 3 hours to replace nitrogen in the flask, and then the solution in the flask was heated in an oil bath to 65 ° C. while stirring, and then emulsified as it was for 5 hours. The polymerization was continued to obtain a styrene acrylic resin particle dispersion (StAc1). The solid content of the styrene acrylic resin particle dispersion (StAc1) was adjusted to 20% by adding ion-exchanged water.
The volume average particle size of the particles in the styrene acrylic resin particle dispersion (StAc1) was 102 nm, and the weight average molecular weight was 55,000.

<Manufacturing of styrene (meth) acrylic modified polyester resin>
[Preparation of Styrene Acrylic Modified Polyester Resin Particle Dispersion Liquid (SPE1)]
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 5670 parts of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane was used. , Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane 585 parts, terephthalic acid 2450 parts and di (2-ethylhexanoic acid) 44 parts, and while stirring in a nitrogen atmosphere. The temperature was raised to 235 ° C. and maintained for 5 hours, then the pressure in the flask was further reduced, and the temperature was maintained at 8.0 kPa for 1 hour. After returning to atmospheric pressure, the mixture was cooled to 190 ° C., 42 parts of fumaric acid and 207 parts of trimellitic acid were added, maintained at a temperature of 190 ° C. for 2 hours, and then heated to 210 ° C. over 2 hours. Further, the pressure in the flask was lowered and maintained at 8.0 kPa for 4 hours to obtain an amorphous polyester resin A (polyester segment).

Next, 857 parts of amorphous polyester resin A was added to a four-necked flask having an internal volume of 2 liters equipped with a cooling tube, a stirrer and a thermocouple, and the mixture was stirred under a nitrogen atmosphere at a stirring speed of 200 rpm. Then, 60 parts of styrene, 60 parts of ethyl acrylate and 500 parts of ethyl acetate were added as addition-polymerizable monomers, and the mixture was further mixed for 30 minutes.
Furthermore, 6 parts of polyoxyethylene alkyl ether (nonionic surfactant, trade name: Emargen 430, manufactured by Kao Co., Ltd.), 15% aqueous solution of sodium dodecylbenzene sulfonate (anionic surfactant, trade name: Neoperex) Add 40 parts of G-15 (manufactured by Kao Co., Ltd.) and 233 parts of 5% potassium hydroxide, heat the temperature to 95 ° C. to melt, and mix at 95 ° C. for 2 hours to prepare a resin mixture solution. Obtained.
Next, while stirring the resin mixture solution, 1145 parts of deionized water was added dropwise at a rate of 6 parts / minute to obtain an emulsion. Next, the obtained emulsion was cooled to 25 ° C., passed through a 200 mesh wire mesh, deionized water was added to adjust the solid content to 20%, and the styrene acrylic modified polyester resin particle dispersion liquid (SPE1) was used. Got
The "mass ratio of styrene (meth) acrylic segment to polyester segment (styrene (meth) acrylic segment / polyester segment)" of the synthesized styrene-acrylic modified polyester resin was 10/90.

[Preparation of Styrene Acrylic Modified Polyester Resin Particle Dispersion Liquid (SPE2)]
Styrene was the same as the styrene acrylic modified polyester resin particle dispersion (SPE1) except that the non-crystalline polyester resin A was changed to 800 parts, the styrene was changed to 110 parts, the ethyl acrylate was changed to 110 parts, and the ethyl acetate was changed to 600 parts. An acrylic-modified polyester resin particle dispersion (SPE2) was obtained.
The “mass ratio of styrene (meth) acrylic segment to polyester segment (styrene (meth) acrylic segment / polyester segment)” of the synthesized styrene-acrylic modified polyester resin was 20/80.

[Preparation of Styrene Acrylic Modified Polyester Resin Particle Dispersion Liquid (SPE3)]
Styrene was the same as the styrene acrylic modified polyester resin particle dispersion (SPE1) except that the non-crystalline polyester resin A was changed to 650 parts, the styrene was changed to 110 parts, the ethyl acrylate was changed to 110 parts, and the ethyl acetate was changed to 600 parts. An acrylic-modified polyester resin particle dispersion (SPE3) was obtained.
The “mass ratio of styrene (meth) acrylic segment to polyester segment (styrene (meth) acrylic segment / polyester segment)” of the synthesized styrene-acrylic modified polyester resin was 35/65.

<Preparation of amorphous polyester resin dispersion>
[Preparation of amorphous polyester resin dispersion (APE1)]
-Bisphenol A ethylene oxide 2.2 mol additive: 40 mol parts-Bisphenol A propylene oxide 2.2 mol additive: 60 mol part-Dimethyl terephthalate: 60 mol part-Dimethyl fumarate: 15 mol part-Dodecenyl succinate anhydride Product: 20 mol parts, trimellitic anhydride: 5 mol parts In a reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas introduction tube, among the above monomers, other than dimethyl fumarate and trimellitic acid anhydride, 0.25 part of tin dioctanoate was added to a total of 100 parts of the above-mentioned monomer. After reacting at 235 ° C. for 6 hours under a nitrogen gas stream, the temperature was lowered to 200 ° C., dimethyl fumarate and trimellitic acid anhydride were added, and the reaction was carried out for 1 hour. The temperature was raised to 220 ° C. over 5 hours and polymerized under a pressure of 10 kPa until the desired molecular weight was obtained to obtain a pale yellow transparent amorphous polyester resin.
The amorphous polyester resin had a weight average molecular weight of 35,000, a number average molecular weight of 8,000, and a glass transition temperature of 59 ° C.
Next, the obtained amorphous polyester resin was dispersed using a disperser obtained by modifying Cavitron CD1010 (manufactured by Eurotec Ltd.) into a high-temperature and high-pressure type. With a composition ratio of 80% ion-exchanged water and 20% polyester resin concentration, the pH is adjusted to 8.5 with ammonia, the rotation speed of the rotor is 60 Hz, the pressure is 5 kg / cm ² , and heating by a heat exchanger is 140. The Cavitron was operated under the condition of ° C. to obtain an amorphous polyester resin dispersion.
The volume average particle diameter of the resin particles in this dispersion was 130 nm. Ion-exchanged water was added to the dispersion to adjust the solid content to 20%, and this was used as an amorphous polyester resin dispersion (APE1).

<Preparation of crystalline polyester resin particle dispersion>
[Preparation of crystalline polyester resin particle dispersion (CPE1)]
・ 1,10-decandycarboxylic acid: 350 parts ・ 1,9-nonanediol: 170 parts Put the above-mentioned monomer component into a reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas introduction tube, and put the monomer component in the reaction vessel. Was replaced with dry nitrogen gas, and then 0.3 part of tin dioctanoate was added to 100 parts of the monomer component. After stirring and reacting at 160 ° C. for 3 hours under a nitrogen gas stream, the temperature is further raised to 180 ° C. over 1.5 hours, the temperature inside the reaction vessel is reduced to 3 kPa, and the reaction occurs when the desired molecular weight is reached. Was completed to obtain a crystalline polyester resin 1. The obtained crystalline polyester resin had a melting temperature of 73 ° C., a weight average molecular weight of 28,000, and an acid value of 7.5 mgKOH / g.
Next, 100 parts of crystalline polyester resin, 60 parts of ethyl acetate, and 15 parts of isopropyl alcohol were put into a reaction vessel equipped with a stirrer and dissolved at 65 ° C. After confirming the dissolution, the reaction vessel was cooled to 60 ° C., and then 5 parts of a 10% aqueous ammonia solution was added. Next, 300 parts of ion-exchanged water was added dropwise to the reaction vessel over 3 hours to prepare a resin dispersion. Next, ethyl acetate and isopropyl alcohol were removed from the resin dispersion with an evaporator, and then ion-exchanged water was added to prepare the resin dispersion so that the solid content concentration was 20%. This was prepared as a crystalline polyester resin dispersion. It was designated as (CPE1).

<Preparation of colorant particle dispersion>
・ Cyan pigment (manufactured by Dainichiseika Co., Ltd., Pigment Blue 15: 3 (copper phthalocyanine)) 45 parts ・ Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 2 parts ・ Ion-exchanged water 250 parts or more The mixture was mixed, dissolved, and dispersed for about 1 hour using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) to obtain a cyan colorant particle dispersion. The volume average particle diameter D50v of the particles in the colorant particle dispersion was 150 nm. Then, ion-exchanged water was added to prepare the solid content concentration to 20.0%.

<Preparation of mold release agent particle dispersion>
[Preparation of release agent particle dispersion (WAX1)]
-Paraffin wax (hydrocarbon wax, HNP9 manufactured by Nippon Seiwa, melting temperature 75 ° C, 2nd endothermic peak temperature of wax (1 2nd endothermic peak) 84 ° C): 270 parts-Anionic surfactant (Daiichi Kogyo) Pharmaceutical Neogen RK): 13.5 parts (60% active ingredient, 3% relative to mold release agent)
-Ion-exchanged water: 21.6 parts After mixing the above materials and dissolving the mold release agent with a pressure discharge type homogenizer (Gorin homogenizer manufactured by Gorin) at an internal liquid temperature of 120 ° C, the dispersion pressure is 5 MPa for 120 minutes. Subsequently, the dispersion treatment was carried out at 40 MPa for 360 minutes and cooled to obtain a dispersion liquid. Ion-exchanged water was added to adjust the solid content to 20%, and this was used as a release agent particle dispersion (WAX1). The volume average particle size of the particles in the release agent particle dispersion liquid (WAX1) was 225 nm.

[Preparation of release agent particle dispersion (WAX2)]
Paraffin wax to terminal carboxylic acid synthetic ester wax (ester wax, Nihon Kasei Crovacs 300-6S, melting temperature 95 ° C, 2nd heat absorption peak temperature of mold release agent (1 2nd heat absorption peak) 95 ° C) A release agent particle dispersion (WAX2) was obtained in the same manner as in the preparation method of the release agent particle dispersion (WAX1) except for the modification.

[Preparation of release agent particle dispersion (WAX3)]
Except for changing the paraffin wax to a polyethylene wax (hydrocarbon wax, Baker Petrolite poly wax 725, melting temperature 104 ° C, 2nd heat absorption peak temperature of mold release agent (1 2nd heat absorption peak) 100 ° C) , A release agent particle dispersion (WAX3) was obtained in the same manner as in the preparation method of the release agent particle dispersion (WAX1).

[Preparation of release agent particle dispersion (WAX4)]
Release agent except that paraffin wax was changed to carnauba wax (vegetable wax (Toa Kasei RC160, melting temperature 85 ° C, 2nd endothermic peak temperature of mold release agent (1 2nd endothermic peak) 86 ° C)). A release agent particle dispersion (WAX4) was obtained in the same manner as in the method for preparing the particle dispersion (WAX1).

<Preparation of mixed particle dispersion>
[Preparation of mixed particle dispersion (RW1)]
After mixing 400 parts of the non-crystalline polyester resin particle dispersion liquid (APE1), 60 parts of the release agent particle dispersion liquid (WAX1), and 2.9 parts of the anionic surfactant (Dowfax2A1 manufactured by Dow Chemical Co., Ltd.), 1.0% nitrate was added at a temperature of 25 ° C. to adjust the pH to 3.0, and a mixed particle dispersion (RW1) was obtained.

[Preparation of mixed particle dispersion liquids (RW2) to (RW4)]
The mixed particle dispersion liquid (RW2) to the same as the mixed particle dispersion liquid (RW1) except that the release agent particle dispersion liquid (WAX1) was changed to the release agent particle dispersion liquid (WAX2) to (WAX4), respectively. (RW4) was obtained.

<Example 1>
-Stylic acrylic resin particle dispersion (StAc1): 375 parts-Stylic acrylic modified polyester resin particle dispersion (SPE1): 42 parts-Crystalline polyester resin particle dispersion (CPE1): 67 parts-Colorant particle dispersion: 75 Part-Ion-exchanged water: 750 parts-Anionic surfactant (Doufax2A1 manufactured by Dow Chemical Co., Ltd.): 3.2 parts In a 3-liter reaction vessel equipped with a thermometer, pH meter, and stirrer, as a material for forming the core part After adding the above materials and adding 1.0% nitrate at a temperature of 25 ° C. to adjust the pH to 3.0, agglomerate while dispersing at 5,000 rpm with a homogenizer (Ultratarax T50 manufactured by IKA). As an agent, 100 parts of a 2.0% aqueous magnesium chloride solution was added and dispersed for 6 minutes.

After that, a stirrer and a mantle heater are installed in the reaction vessel, and while adjusting the rotation speed of the stirrer so that the slurry is sufficiently agitated, the temperature rise rate is 0.2 ° C./min up to a temperature of 40 ° C., 40. The temperature was raised from above ° C. to 53 ° C. at a heating rate of 0.05 ° C./min, and the particle size was measured every 10 minutes with Multisizer II (aperture diameter 50 μm, manufactured by Beckman-Coulter). The temperature was maintained when the volume average particle diameter reached 5.0 μm, and 205 parts of the mixed particle dispersion liquid (RW1) was added as a material for forming the shell layer over 5 minutes.
When the core particle size of the toner particles is 6.6 μm as the central particle size and the core / shell ratio is adjusted in the range of 68/32 or more and 72/28 or less, the core / shell ratio of the toner particles is 7 :. Get 3.

After holding at 50 ° C. for 30 minutes, 8 parts of a 20% solution of EDTA (ethylenediaminetetraacetic acid) was added to the reaction vessel, and then a 1 mol / L sodium hydroxide aqueous solution was added to adjust the pH of the raw material dispersion to 9.0. Controlled. Then, while adjusting the pH to 9.0 every 5 ° C., the temperature was raised to 90 ° C. at a heating rate of 1 ° C./min and maintained at 90 ° C. When the particle shape and surface properties were observed with an optical microscope and a field emission scanning electron microscope (FE-SEM), the coalescence of the particles was confirmed at 6 hours, so the container was heated to 30 ° C. for 5 minutes with cooling water. It was cooled over.

The cooled slurry was passed through a nylon mesh having an opening of 15 μm to remove coarse powder, and the toner slurry that had passed through the mesh was filtered under reduced pressure with an aspirator. The solid content remaining on the filter paper was crushed as finely as possible by hand, poured into ion-exchanged water having a temperature of 30 ° C., which was 10 times the solid content, and stirred and mixed for 30 minutes. Next, the mixture is vacuum-filtered with an ejector, the solid content remaining on the filter paper is crushed by hand as finely as possible, poured into ion-exchanged water having a temperature of 30 ° C., which is 10 times the solid content, stirred and mixed for 30 minutes, and then again with an ejector. The filtrate was filtered under reduced pressure, and the electrical conductivity of the filtrate was measured. This operation was repeated until the electrical conductivity of the filtrate became 10 μS / cm or less, and the solid content was washed.
The washed solid content was finely crushed with a wet dry granulator (comil) and vacuum dried in an oven at 35 ° C. for 36 hours to obtain toner particles. The toner particles had a volume average particle size of 6.6 μm.

Next, 1.5 parts of hydrophobic silica (RY50 manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts of the obtained toner particles, and the mixture was mixed at 13000 rpm for 30 seconds using a sample mill. Then, the toner was sieved with a vibrating sieve having a mesh size of 45 μm to obtain the toner of Example 1.

<Examples 2 to 10>
The toners of each example were used in the same manner as the toner of Example 1 except that the types of the material for forming the core portion (resin particle dispersion liquid), the coagulant, and the material for the shell layer (resin particle dispersion liquid) were changed. Obtained.
In Example 6, a toner was obtained in the same manner as in Example 1 except that the type of coagulant was changed to an aqueous aluminum sulfate solution.

<Comparative Examples 1 to 3>
The toners of each example were used in the same manner as the toner of Example 1 except that the types of the material for forming the core portion (resin particle dispersion liquid), the coagulant, and the material for the shell layer (resin particle dispersion liquid) were changed. Obtained.

<Measurement>
For the toners obtained in each example, the abundance rate of the release agent, the domain diameter of the release agent (average diameter of the domain), and the exposure rate of the release agent were measured according to the methods described above.

<Evaluation>
(Preparation of developer)
36 parts of the toner and 414 parts of the carrier of each example were placed in a 2 liter V blender, stirred for 20 minutes, and then sieved at 212 μm to prepare a developer. However, the following resin-coated carrier was used as the carrier.

-Preparation of resin-coated carrier-
-Mn-Mg-Sr-based ferrite particles (average particle size 40 μm): 100 parts-Toluene: 14 parts-Polymethyl methacrylate: 2.0 parts-Carbon black (VXC72: manufactured by Cabot): 0.12 parts Ferrite particles The above components and glass beads (φ1 mm, the same amount as toluene) to be removed were stirred at 1200 rpm for 30 minutes using a sand mill manufactured by Kansai Paint Co., Ltd. to obtain a solution for forming a resin coating layer. Further, the resin coating layer forming solution and the ferrite particles were placed in a vacuum degassing type kneader, depressurized, and toluene was distilled off and dried to prepare a resin coating carrier.

(Evaluation of heat storage)
2 g of the toner obtained in each example was stored in an environment of 55 ° C. and 50% RH for 12 hours, and the toner state after storage was visually observed and evaluated based on the following evaluation criteria.
-A: Almost no toner aggregates are observed even after storage at 55 ° C, and the heat storage property is excellent.
-B: Toner aggregates are slightly observed after storage at 55 ° C., and the heat storage property is slightly inferior to that of A.
-C: Toner agglomerates are observed after storage at 55 ° C., which is inferior in heat storage property to A.
-D: Toner is agglomerated after storage at 55 ° C. and does not have heat storage property.
It is assumed that there is no practical problem in the above A to C.

(Evaluation of set-off of fixed image)
The developer of each example was filled in the developer of "Color MFP ApeosPort-IV C5570" manufactured by Fuji Xerox Co., Ltd.
In a high temperature environment (temperature 40 ° C., humidity 50% RH environment), using this image forming device, images with an image density of 50% are continuously printed on A4 size paper (basis weight 52 g) at a process speed of 225 mm / sec. 50 sheets were output on both sides of (/ m ² thin paper), and A4 paper on which an image was formed was overlaid. Then, after 5 hours had passed, the portion of the second output sheet that was in contact with the image of the first sheet was observed, and document blocking was evaluated.
A: No set-off of the fixed image was confirmed, and a very good image was obtained.
B: Although a slight set-off of the fixed image occurs on the paper, there is no image defect and a good image is obtained.
C: There is a slight set-off of the fixed image on the entire surface of the paper, but there is no image loss and it is acceptable in actual use.
D: Set-off of the fixed image occurs and image loss occurs, which is unacceptable in actual use.

(Evaluation of low temperature fixability)
The developer obtained in each example was filled in the developer of the experimental remodeling machine of ApeosPort-IV C5570 from which the fixing device was taken out, and the toner loading amount was ^{adjusted to 0.45 mg / cm 2} and unfixed. The image was output. As a recording medium, P paper (A4 paper, manufactured by Fuji Xerox Co., Ltd.) was used to form an unfixed image having an image density of 100% and a size of 50 mm × 50 mm on one side. As the fixing evaluation device, a fixing device of ApeosPortIV C5570 manufactured by Fuji Xerox Co., Ltd. was removed and modified so that the fixing temperature could be changed. The nip width of the fuser was 6 mm, the nip pressure was 1.6 kgf / cm ² , the Dwell-time (fixing time: nip passage time) was 34.7 ms, and the process speed was 175 mm / sec. The unfixed image was fixed at intervals of 100 ° C. to 5 ° C., and the presence or absence of cold offset was visually confirmed, and the temperature at which the cold offset disappeared was evaluated as the cold offset disappearance temperature. This was used as an index of low temperature fixability.
-Evaluation criteria-
A: 145 ° C or less B: 145 ° C or more and 150 ° C or less C: 150 ° C or more and 160 ° C or less D: 160 ° C or less

The details of each example are listed below in Tables 1 and 2.
The abbreviations of Tables 1 and 2 are as follows.
-Collector column-
-Al2 (SO4) 3: Aluminum sulfate aqueous solution with a concentration of 2.0% -MgCl2: Magnesium chloride aqueous solution with a concentration of 2.0% -Toner characteristics column-
St / PE segment ratio of SPEC: Mass ratio of styrene (meth) acrylic segment and polyester segment in styrene (meth) acrylic modified polyester resin ・ StAc / SPEC mass ratio: styrene (meth) acrylic resin and styrene (meth) acrylic modified Mass ratio with polyester resin (styrene (meth) acrylic resin / styrene (meth) acrylic modified polyester resin)

From the above results, it can be seen that the toner of this example has heat storage property and suppresses set-off of the fixed image as compared with the toner of the comparative example.
It can also be seen that the toner of this example has low temperature fixability.

1Y, 1M, 1C, 1K photoconductor (example of image holder)
2Y, 2M, 2C, 2K charging roll (an example of charging means)
3 Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K laser beam 4Y, 4M, 4C, 4K developing device (example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (example of primary transfer means)
6Y, 6M, 6C, 6K Photoreceptor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner Cartridge 10Y, 10M, 10C, 10K Image Forming Unit 20 Intermediate Transfer Belt (Example of Intermediate Transfer)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photoreceptor (example of image holder)
108 Charging roll (an example of charging means)
109 Exposure device (an example of static charge image forming means)
111 Developing equipment (an example of developing means)
112 Transfer device (an example of transfer means)
113 Photoreceptor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Mounting rail 118 Opening for exposure 117 Housing 200 Process cartridge 300 Recording paper (an example of recording medium)
P Recording paper (an example of recording medium)

Claims (12)

A core portion containing at least a non-crystalline resin (A) containing a styrene (meth) acrylic resin and a styrene (meth) acrylic-modified polyester resin, and the core portion are coated with at least the non-crystalline resin (B) and a hydrocarbon. It has a shell layer containing a mold release agent containing a styrene wax, and has toner particles having
The content of the styrene (meth) acrylic resin is 80% by mass or more and 95% by mass or less with respect to the toner particles.
A toner for static charge image development in which 70% or more of the release agents are present within 1000 nm from the surface of the toner particles. The toner for static charge image development according to claim 1, wherein the exposure rate of the release agent on the surface of the toner particles is 1% or more and 6% or less. Claim 1 or claim, wherein the release agent is a release agent having at least one endothermic peak obtained in the second heating process by a differential scanning calorimeter (DSC) in the range of 60 ° C. or higher and 100 ° C. or lower. 2. The toner for developing an electrostatic charge image according to 2. The toner for developing an electrostatic charge image according to any one of claims 1 to 3, wherein the toner particles contain a metal having a divalent ionic valence. The toner for developing an electrostatic charge image according to claim 4, wherein the metal contains at least Mg. The mass ratio of the styrene (meth) acrylic resin to the styrene (meth) acrylic-modified polyester resin (styrene (meth) acrylic resin / styrene (meth) acrylic-modified polyester resin) is 80/20 or more and 95/5 or less. The toner for developing an electrostatic charge image according to any one of claims 1 to 5. In the styrene (meth) acrylic-modified polyester resin, the mass ratio of the styrene (meth) acrylic segment to the polyester segment (styrene (meth) acrylic segment / polyester segment) is 5/95 or more and 30/70 or less. The toner for developing an electrostatic charge image according to any one of claim 6. A static charge image developer containing the toner for static charge image development according to any one of claims 1 to 7. The toner for developing an electrostatic charge image according to any one of claims 1 to 7 is accommodated in the toner.
A toner cartridge that is attached to and detached from the image forming device. A developing means for accommodating the electrostatic charge image developing agent according to claim 8 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided.
A process cartridge that is attached to and detached from the image forming device. Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means for accommodating the electrostatic charge image developer according to claim 8 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus comprising. The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to claim 8.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.

Images