JP6935678B2 - Pressure fixing toner for static charge image development, electrostatic 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 to the recording medium. Through these steps, the image information is visualized as an image.

For example, Patent Document 1 states, "A toner obtained by aggregating resin particles having a core-shell structure, in which the resin constituting the core and the shell is both an amorphous resin and the glass of the resin constituting the core. The transition temperature and the glass transition temperature of the resin constituting the shell differ by 20 ° C. or more, and the resin constituting the shell contains an acidic or basic polar group or an alcoholic hydroxyl group to fix the pressure for static charge image development. "Toner for plastic" is disclosed.

Further, Patent Document 2 states that "the difference between the glass transition temperature of the resin that forms the sea-island structure and the sea phase and the glass transition temperature of the resin that forms the island phase is 30 ° C. or more. , The glass transition temperature of the resin is less than 55 ° C., and the major axis of the island phase is 150 nm or less.

Further, Patent Document 3 discloses "a pressure-fluid toner containing a block copolymer having at least two types of blocks having a glass transition temperature difference of 50 to 200 ° C.".

Further, Patent Document 4, "oxidative-polymerizable monomer and / or polymer having an ethylenically unsaturated bond, and contains an oxidation polymerization catalyst, and a viscosity in a flow tester applied pressure 10MPa is 10 ⁴ Pa - temperature at which becomes s T and (10 MPa), the temperature T (1 MPa) Togashiki (1) when the viscosity becomes ¹⁰ 4 Pa · s at a flow tester applied pressure 1MPa: 20 ℃ ≦ T (1MPa ) - Toner for developing an electrostatic charge image that satisfies T (10 MPa) ≦ 120 ° C. ”is disclosed.

Japanese Unexamined Patent Publication No. 2009-053318 Japanese Unexamined Patent Publication No. 2009-244857 Japanese Unexamined Patent Publication No. 2011-017915 JP-A-2010-175734

The subject of the present invention is a sea-island structure containing a styrene resin and a (meth) acrylic acid ester resin, which is composed of a sea part containing a styrene resin and an island part containing a (meth) acrylic acid ester resin, and is more than a styrene resin. In the pressure fixing toner for static charge image development in which the glass transition temperature of the (meth) acrylic acid ester resin is lower than 30 ° C., the recording medium in which the fixed image is fixed is stacked as compared with the case where the oxidative polymerizable compound is not contained. Pressure for static charge image development that suppresses the phenomenon that the fixed image of the lower recording medium is settled to the back surface of the upper recording medium (hereinafter, also referred to as "pen offset") when characters or the like are drawn with a writing tool. It is to provide a fixing toner.

The above problem is solved by the following means.

The invention according to <1 > is
It contains a styrene resin, a (meth) acrylic acid ester resin and an oxidatively polymerizable compound, and has a sea-island structure composed of a sea portion containing the styrene resin and an island portion containing the (meth) acrylic acid ester resin, and the styrene. A pressure fixing toner for static charge image development in which the glass transition temperature of the (meth) acrylic acid ester resin is lower than that of the resin by 30 ° C. or more.

The invention according to <2 > is
The pressure fixing toner for static charge image development according to < 1 > , wherein at least one of the styrene resin and the (meth) acrylic acid ester resin is a resin having an allyl group.

The invention according to <3 > is
The pressure fixing toner for developing an electrostatic charge image according to < 2 > , wherein the (meth) acrylic acid ester resin is a resin having an allyl group.

The invention according to <4 > is
A core portion containing the styrene resin, the (meth) acrylic acid ester resin, and the oxidatively polymerizable compound and having the sea-island structure, and the core portion.
A coating layer that covers the core portion and contains a resin having a glass transition temperature of 50 ° C. or higher,
The pressure fixing toner for developing an electrostatic charge image according to any one of < 1 > to < 3 >.

The invention according to <5 > is
The pressure fixing toner for developing an electrostatic charge image according to < 4 > , wherein the resin of the coating layer is a styrene resin and has an allyl group.

The invention according to <6 > is
The oxidatively polymerizable compound is at least one selected from the group consisting of a phenol derivative having an aliphatic hydrocarbon group having an ethylenic double bond bonded to phenol and a drying oil < 1 > to < 5. > The pressure fixing toner for developing an electrostatic charge image according to any one of the above items.

The invention according to <7 > is
The pressure fixing toner for developing an electrostatic charge image according to any one of < 1 > to < 6 > , wherein the iodine value of the oxidatively polymerizable compound is 130 g / 100 g or more.

The invention according to <8 > is
An electrostatic charge image developer containing the pressure fixing toner for developing an electrostatic charge image according to any one of < 1 > to < 7 >.

The invention according to <9 > is
The pressure fixing toner for developing an electrostatic charge image according to any one of <1 > to < 7 > is housed in the toner.
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 developing agent according to < 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.

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 >, it has a sea-island structure containing a styrene resin and a (meth) acrylic acid ester resin, and is composed of a sea part containing a styrene resin and an island part containing a (meth) acrylic acid ester resin. , A static charge image that suppresses pen offset in a pressure fixing toner for static charge image development in which the glass transition temperature of the (meth) acrylic acid ester resin is 30 ° C. or more lower than that of the styrene resin, as compared with the case where the oxidative polymerizable compound is not contained. A pressure fixing toner for development is provided.
According to the invention according to < 2 > , both the styrene resin and the (meth) acrylic acid ester resin are static charge image development that suppresses pen offset as compared with the case where the resin does not have an allyl group. Pressure fixing toner for use is provided.
According to the invention according to < 3 > , a pressure fixing toner for static charge image development that suppresses pen offset is provided as compared with the case where only the styrene resin is a resin having an allyl group.
According to the invention of < 4 > , a pressure fixing toner for static charge image development that suppresses deformation of the toner is provided as compared with the case of a single layer type toner having no coating layer.
According to the invention of < 5 > , a pressure fixing toner for static charge image development that suppresses pen offset is provided as compared with the case where only the styrene resin in the core portion is a resin having an allyl group.
According to the invention according to < 6 > , a pressure fixing toner for developing an electrostatic charge image that suppresses pen offset is provided as compared with the case where the oxidatively polymerizable compound is not contained.

According to the invention of < 7 > , a pressure fixing toner for static charge image development that suppresses pen offset is provided as compared with the case where the iodine value of the oxidatively polymerizable compound is less than 130 g / 100 g.
According to the invention according to < 8 > , < 9 > , < 10 > , < 11 > , or < 12 > , the sea part containing styrene resin and (meth) acrylic acid ester resin, and the sea part containing styrene resin and (meth) acrylic. Oxidation polymerization in a pressure fixing toner for static charge image development, which has a sea-island structure composed of islands containing an acid ester resin and has a glass transition temperature of a (meth) acrylic acid ester resin lower than that of a styrene resin by 30 ° C. or more. It is possible to provide an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method that suppresses pen offset as compared with the case where no sex compound is contained.

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 in detail.

<Toner for static charge image development>
The pressure-fixing toner for static charge image development (hereinafter, also referred to as “toner” or “pressure-fixing toner”) according to the present embodiment includes a styrene resin, a (meth) acrylic acid ester resin, and an oxidatively polymerizable compound. Specifically, the pressure fixing toner is a toner having a structure having toner particles containing these components.
The pressure-fixing toner (the toner particles thereof) has a sea-island structure composed of a sea part containing a styrene resin and an island part containing a (meth) acrylic acid ester resin. However, the glass transition temperature of the (meth) acrylic acid ester resin is lower than that of the styrene resin by 30 ° C. or more.

According to the above configuration, the pressure fixing toner according to the present embodiment has a pen offset (when characters or the like are drawn with a writing instrument in a state where the recording media on which the fixing image is fixed are overlapped, the fixing image of the lower recording medium is formed. The phenomenon of set-off to the back surface of the upper recording medium) is suppressed. The reason is presumed as follows.

The pressure fixing toner is a toner that exhibits plasticity by pressurization. As one of them, a styrene resin and a (meth) acrylic acid ester resin having a glass transition temperature lower than that of the styrene resin by 30 ° C. or more are included, and the sea part containing the styrene resin and the island part containing the (meth) acrylic acid ester resin. A pressure-fixing toner having toner particles having a constructed sea-island structure is known.

However, the fixing image by the pressure fixing toner containing the styrene resin and the (meth) acrylic acid ester resin having a glass transition temperature lower than that of the styrene resin by 30 ° C. or more in the toner particles contains the resin having a low glass transition temperature. Tends to decrease in strength. Further, the (meth) acrylic acid ester resin having a low glass transition temperature is unevenly distributed on the surface layer of the fixed image, and the adhesiveness of the surface of the fixed image tends to be developed. Therefore, when characters or the like are drawn with a writing instrument in a state where the recording media on which the fixed image is fixed are overlapped, the fixed image of the lower recording medium may be set off on the back surface of the upper recording medium. That is, a pen offset may occur.

On the other hand, when the pressure-fixing toner contains an oxidatively polymerizable compound, the oxidatively polymerizable compound existing inside the toner comes into contact with oxygen in the air in the fixed image by the pressure-fixing toner, and a polymerization reaction occurs. As a result, the strength of the fixed image is increased, and the development of stickiness is less likely to occur. Therefore, even if pressure is applied by the writing tool, the fixed image of the lower recording medium is less likely to set off on the back surface of the upper recording medium.

From the above, it is presumed that the pressure fixing toner according to the present embodiment suppresses the pen offset.

Here, the pressure fixing toner according to the present embodiment may be a single-layer type toner or a core-shell toner having a core portion and a shell layer covering the core portion. That is, the pressure-fixing toner may have a configuration having single-layer type toner particles, or may have a configuration having core-shell toner particles having a core portion and a shell layer.
In the case of core-shell toner (core-shell toner particles), the core portion has the above-mentioned sea-island structure. That is, the core portion has a sea-island structure containing a styrene resin, a (meth) acrylic acid ester resin and an oxidatively polymerizable compound, and is composed of a sea portion containing the styrene resin and an island portion containing the (meth) acrylic acid ester resin. ..
Here, the oxidatively polymerizable compound may be contained in the shell layer, but it is preferable that the oxidatively polymerizable compound is not contained in the shell layer from the viewpoint of suppressing the oxidative polymerization of the oxidatively polymerizable compound on the surface of the toner (toner particles).

In the pressure fixing toner according to the present embodiment, at least one resin of the styrene resin, the (meth) acrylic acid ester resin, and the resin of the shell layer is preferably a resin having an allyl group from the viewpoint of suppressing pen offset. .. That is, it is preferable that at least one of these resins has an allyl group. The resin of the coating layer is preferably a styrene resin having an allyl group.
When a resin having an allyl group is applied, the allyl group of the resin reacts with the oxidatively polymerizable compound in the fixed image with the pressure fixing toner, so that the strength of the fixed image is further increased and the adhesiveness is also lowered. Therefore, the pen offset is easily suppressed.

When a resin having an allyl group is applied as the (meth) acrylic acid ester resin among the above three types of resins, the pen offset is more likely to be suppressed. In particular, when the (meth) acrylic acid ester resin is a resin having an allyl group, the (meth) acrylic acid ester resin unevenly distributed on the surface layer of the fixed image reacts with the oxidatively polymerizable compound, so that the strength of the fixed image is further increased. , The adhesiveness is also reduced. Therefore, it is preferable that the (meth) acrylic acid ester resin is a resin having an allyl group.

In order to introduce an allyl group into the above three types of resins, for example, a monomer having an allyl group is used together with a monomer for synthesizing each of them. The monomer having an allyl group will be described later.

The content of the allyl group in the resin is preferably 1 mmol% or more and 20 mmol% or less, more preferably 3 mmol% or more and 15 mmol% or less, and further preferably 5 mmol% or more and 15 mmol% or less from the viewpoint of achieving both pen offset suppression and fixability.

Hereinafter, the pressure fixing toner according to the present embodiment will be described in detail.

The pressure fixing toner according to this embodiment has toner particles. The toner may have an external additive that is externally added to the toner particles.
The core-shell toner particles having a core portion and a shell layer will be described as the toner particles, but the present invention is not limited to this, and the toner particles may be single-layer type toner particles.

[Toner particles]
The toner particles have a core portion containing a styrene resin, a (meth) acrylic acid ester resin, and an oxidatively polymerizable compound, and a shell layer covering the core portion and containing a resin having a glass transition temperature of 50 ° C. or higher.

In addition to the styrene resin and the (meth) acrylic acid ester resin, the core portion may contain a colorant, a mold release agent, and other additives as the binder resin.

(Core part)
-Sea island structure-
The sea-island structure of the core portion shows a structure in which the sea portion containing the styrene resin is a continuous phase and the island portion containing the (meth) acrylic acid ester resin is dispersed as a dispersed phase.
The sea part may contain other components (other binding resins, etc.) together with the styrene resin. Similarly, Shimabe may also contain other components (release agent, etc.) together with the meta) acrylic acid ester resin. Further, the islands may be a mixture of islands of (meth) acrylic ester resin alone and islands of other components (release agent, etc.) alone.
Here, the oxidatively polymerizable compound may be contained in either the sea part or the island part.

The smaller the major axis of the island part of the sea-island structure, the higher the pressure plasticity and the pressure fixing property, while the toner particles tend to be deformed easily. The larger the diameter, the lower the pressure plasticity and the lower the pressure fixing property. On the other hand, the toner particles tend to be deformed easily. Therefore, the major axis of the island portion of the sea island structure is preferably 200 nm or more and 500 nm or less. The major axis of the island portion of the sea-island structure is more preferably 200 nm or more and 450 nm or less, and further preferably 250 nm or more and 400 nm or less, from the viewpoint of suppressing toner deformation and pressure fixability.
However, when giving priority to pressure fixability, the major axis of the island portion may be less than 200 nm (for example, in the range of 150 nm or less, 5 nm or more and 150 nm or less, 50 nm or more and 140 nm or less, 100 nm or more and 130 nm or less).

As a method for setting the major axis of the island portion of the sea-island structure in the range of 200 nm or more and 500 nm or less, for example, in the production of toner by the emulsion aggregation method, styrene resin particles in which a plurality of (meth) acrylic ester resin domains are dispersed inside. (That is, a method using a styrene resin as a base material and resin particles in which a plurality of (meth) acrylic ester resin domains are dispersed in the base material) can be mentioned.

Confirmation of the sea-island structure and measurement of the major axis of the islands are carried out by the following methods.
After embedding the toner in epoxy resin, a section is prepared with a diamond knife or the like, the prepared section is stained with osmium tetroxide or ruthenium tetroxide in a desiccator, and the stained section is stained with a transmission electron microscope. Observe. Then, the sea part and the island part of the sea-island structure are distinguished by the shade due to the degree of dyeing of the resin by osmium tetroxide, and the presence or absence of the sea-island structure is confirmed by using this. Even when a release agent is included, it can be distinguished by the shade due to the degree of staining with osmium tetroxide. The degree of dyeing of the styrene resin, the (meth) acrylic acid ester resin, and the mold release agent is deeply dyed in the order of the (meth) acrylic acid ester resin, the styrene resin, and the mold release agent.
Further, 100 islands are selected using a Luzex image analyzer, and the average value of the major axis thereof is calculated as the major axis of the islands.

-Bound resin-
As the binder resin, a styrene resin and a (meth) acrylic acid ester resin are applied.
The glass transition temperature of the (meth) acrylic acid ester resin is lower than that of the styrene resin by 30 ° C. or more. That is, the difference in glass transition temperature between the styrene resin and the (meth) acrylic acid ester resin is 30 ° C. or more, and the glass transition temperature of the (meth) acrylic acid ester resin is lower than that of the styrene resin.
In the specification, the styrene resin is also referred to as "high Tg styrene resin", and the (meth) acrylic acid ester resin is also referred to as "low Tg (meth) acrylic acid ester resin".

The difference in glass transition temperature between the styrene resin and the (meth) acrylic acid ester resin is preferably 35 ° C. or higher from the viewpoint of improving pressure fixability.

The glass transition temperature of the styrene resin is preferably 40 ° C. or higher, more preferably 40 ° C. or higher and lower than 60 ° C., and further preferably 40 ° C. or higher and lower than 55 ° C. from the viewpoint of improving pressure fixability.
On the other hand, the glass transition temperature of the (meth) acrylic ester resin is preferably less than 10 ° C., more preferably -100 ° C. or higher and lower than 10 ° C., and further preferably -80 ° C. or higher and lower than 10 ° C. from the viewpoint of improving pressure fixability. ..

The glass transition temperature of each resin can be controlled mainly by the density of rigid units such as an aromatic ring and a cyclohexane ring in the main chain of the resin. That is, the glass transition temperature tends to decrease as the density of flexible units such as methylene group, ethylene group, and oxyethylene group in the main chain increases, and increase as the number of rigid units such as aromatic ring and cyclohexane ring increases. There is. Further, when the density of side chains such as aliphatics is increased, the glass transition temperature tends to decrease. By considering these, resins having various glass transition temperatures can be obtained.

Here, in the present specification, the glass transition temperature of each resin is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, in JIS K7121-1987 "Method for measuring transition temperature of plastics". It is obtained by the "external glass transition start temperature" described in How to obtain the glass transition temperature.

Next, the composition of the styrene resin will be described.
The styrene resin is a resin obtained by at least polymerizing a styrene-based monomer (a monomer having a styrene skeleton).
The styrene resin may be a styrene-based monomer homopolymer or a copolymer of a styrene-based monomer and another monomer.
As long as the styrene resin and the (meth) acrylic acid ester resin have a glass transition temperature difference of 30 ° C. or more, even if they are the same type of resin (copolymer obtained by polymerizing the same monomer). good. That is, both the styrene resin and the (meth) acrylic acid ester resin may be a copolymer obtained by at least polymerizing the styrene-based monomer and the (meth) acrylic acid ester.

Examples of the styrene-based monomer include styrene; vinylnaphthalene; α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn. Alkyl-substituted styrenes such as -butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, and pn-dodecyl styrene. Aryl-substituted styrenes such as p-phenylstyrene; alkoxy-substituted styrenes such as p-methoxystyrene; halogen-substituted styrenes such as p-chlorostyrene, 3,4-dichlorostyrene, 4-fluorostyrene, 2,5-difluorostyrene; Examples thereof include nitro-substituted styrenes such as m-nitrostyrene, o-nitrostyrene, and p-nitrostyrene.
Among these, styrene, p-ethyl styrene, pn-butyl styrene and the like are preferable, and styrene is more preferable.

The ratio of the styrene-based monomer to all the monomer components (that is, the ratio of the constituent units derived from the styrene-based monomer to the styrene resin) is preferably 15% by mass or more and 95% by mass or less, preferably 40% by mass or more. More preferably, it is 90% by mass or less.

These monomers may be used alone or in combination of two or more.

Next, the composition of the (meth) acrylic ester resin will be described.
The (meth) acrylic acid ester resin is a polymer obtained by at least polymerizing the (meth) acrylic acid ester.
The (meth) acrylic acid ester resin may be a (meth) acrylic acid ester homopolymer or a copolymer obtained by polymerizing a (meth) acrylic acid ester and another resin.

Examples of the (meth) acrylic acid ester include (meth) acrylic acid alkyl ester, di (meth) acrylic acid ester, (meth) acrylic acid carboxy-substituted alkyl ester, and (meth) acrylic acid alkoxy-substituted alkyl ester.

Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid, (meth) acrylic acid n-methyl, (meth) acrylic acid n-ethyl, (meth) acrylic acid n-propyl, and (meth) acrylic acid n-. Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, (meth) N-dodecyl acrylate, n-lauryl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, isopropyl (meth) acrylate, ( Isobutyl acrylate, t-butyl (meth) acrylate, isopentyl (meth) acrylate, amyl (meth) acrylate, neopentyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, Isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate , (Meta) dicyclopentanyl acrylate, isobornyl (meth) acrylate and the like.

Examples of the di (meth) acrylic acid ester include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, and pentanediol di (meth) acrylate. Examples thereof include hexanediol di (meth) acrylate, nonanediol di (meth) acrylate, and decanediol di (meth) acrylate.
Examples of the (meth) acrylic acid carboxy-substituted alkyl ester include β-carboxyethyl (meth) acrylic acid.
Examples of the (meth) acrylic acid hydroxy-substituted alkyl ester include (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylic acid 3-hydroxypropyl, and (meth) acrylic acid 2-hydroxy. Examples thereof include butyl, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.
Examples of the (meth) acrylic acid alkoxy-substituted alkyl ester include 2-methoxyethyl (meth) acrylic acid.

Among these, as the (meth) acrylic acid ester, a (meth) acrylic acid alkyl ester having an alkyl group having 2 or more and 22 or less carbon atoms is preferable.

The ratio of the (meth) acrylic acid ester to all the monomer components (that is, the ratio of the constituent units derived from the (meth) acrylic acid ester to the (meth) acrylic acid ester resin) is 10% by mass or more and 100% by mass or less. Is preferable, and 20% by mass or more and 100% by mass or less is more preferable.

Next, other monomers of the styrene resin and the (meth) acrylic ester resin will be described.
Examples of other monomers include ethylenically unsaturated nitriles such as acrylonitrile and methacrylonitrile; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; vinyl methyl ether and vinyl isobutyl ether. Vinyl ethers; vinyl ketones such as vinyl methyl ketones, vinyl ethyl ketones, vinyl isopropenyl ketones; olefins such as isoprene, butene, butadiene and the like.
Examples of the styrene resin include the above-mentioned (meth) acrylic acid ester. On the other hand, as another monomer of the (meth) acrylic acid ester resin, the above-mentioned styrene-based monomer can also be mentioned.

Here, the styrene resin and the (meth) acrylic acid ester resin include acidic polar groups (carboxy group, sulfonic acid group, acid anhydride, etc.), basic polar groups (amino group, amide group, hydrazide group, etc.), alcohol. It may have a sex hydroxyl group.
Therefore, examples of the other monomer include a monomer having an acidic polar group, a monomer having a basic group, and a monomer having an alcoholic hydroxyl group.

Examples of the monomer having an acidic polar group include α, β-ethylenically unsaturated compounds (acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, sulfonated styrene, allylsulfosuccinic acid, etc.). Can be mentioned.

Preferred examples of the monomer having a basic polar group include a monomer having the nitrogen atom (for example, a (meth) acrylic acid amide compound, a (meth) acrylic acid hydrazide compound, or a (meth) acrylic acid aminoalkyl. ..
Examples of the (meth) acrylic acid amide compound include acrylic acid amide, methacrylic acid amide, acrylic acid methyl amide, methacrylic acid methyl amide, acrylic acid dimethyl amide, acrylic acid diethyl amide, acrylic acid phenyl amide, and acrylic acid benzyl amide.
Examples of the (meth) acrylic acid hydrazide compound include acrylic acid hydrazide, methacrylic acid hydrazide, methyl acrylate hydrazide, methyl methacrylate hydrazide, dimethyl hydrazide acrylate, and phenyl hydrazide acrylate.
Examples of the (meth) acrylate aminoalkyl include (meth) acrylate monoalkylaminoalkyl (for example, 2-aminoethyl acrylate, 2-aminoethyl methacrylate, etc.) and meta) dialkylaminoalkyl acrylate (for example, (meth)). 2- (Diethylamino) ethyl acrylate, etc.) and the like can be mentioned.

Examples of the monomer having an alcoholic hydroxyl group include (meth) acrylic acid hydroxy-substituted alkyl esters exemplified by (meth) acrylic acid esters.

Further, as another monomer, a monomer having an allyl group can also be mentioned.
Examples of the monomer having an allyl group include allyl (meth) acrylate, N-allyl (meth) acrylamide, N, N-diallyl (meth) acrylamide, and N-alkyl-N-allyl (meth) acrylamide (for example, N-). "N-alkyl having an alkyl group having 1 to 10 carbon atoms" such as methyl-N-allyl (meth) acrylamide, N-ethyl-N-allyl (meth) acrylamide, N-butyl-N-allyl (meth) acrylamide, etc. -N-allyl (meth) acrylamide "), N-phenyl-N-allyl (meth) acrylamide, N-substituted phenyl-N-allyl (meth) acrylamide (eg, N- (2-tert-butylphenyl) -N Examples thereof include phenyl groups substituted with alkyl groups having 1 or more and 5 or less carbon atoms, such as −allylacrylamide and N- (2,5-di-tert-butylphenyl) -N-allylacrylamide.
Among these, allyl methacrylate is preferable as the monomer having an allyl group from the viewpoint of suppressing pen offset.

Each of the monomers described above may be used alone or in combination of two or more.

Next, the contents of the styrene resin and the (meth) acrylic acid ester and other properties will be described.
The total ratio of the styrene resin and the (meth) acrylic acid ester resin (ratio to the total binder resin) is, for example, preferably 85% by mass or more, preferably 95% by mass or more, and more preferably 100% by mass.

The mass ratio of (meth) acrylic acid ester resin to styrene resin "(meth) acrylic acid ester resin / styrene resin)" is preferably 0.25 or more, preferably 0, from the viewpoint of suppressing toner deformation and pressure fixability. .3 or more is more preferable, 0.4 or more is further preferable, and 0.5 or more is particularly preferable. However, this mass ratio is preferably less than 1.5 from the viewpoint of suppressing the plasticization of the toner at room temperature (for example, 25 ° C.).

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.

The weight average molecular weight of the styrene resin is preferably 3,000 to 50,000, more preferably 5,000 to 40,000 from the viewpoint of pressure fixability and the strength of the fixed image.
The weight average molecular weight of the (meth) acrylic ester resin is 3,000 to more from the viewpoint of pressure fixability and suppression of toner filming (development in which toner adheres to the surface of the image holder in the form of a thin film) of the image holder. 50,000 is preferable, and 5,000 to 40,000 is more preferable.

The weight average molecular weight of the resin is 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 is calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

Next, a binder resin other than the styrene resin and the (meth) acrylic acid ester resin will be described.
As the binder resin, other binder resins may be used in combination with the styrene resin and the (meth) acrylic acid ester resin.
Examples of other binder resins include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.), (meth) acrylic acid esters (eg, methyl acrylate, ethyl acrylate, n-propyl acrylate, etc.). N-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (eg, 2-ethylhexyl methacrylate) Acrylonitrile, methacrylonitrile, 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, propylene, butadiene, etc.) ) Or a homopolymer of a monomer such as), or a vinyl-based resin composed of a copolymer obtained by combining two or more kinds of these monomers.
Examples of other binder resins include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence of these.
These other binder resins may be used alone or in combination of two or more.

The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and 60% by mass or more and 85% by mass or less with respect to the entire toner particles. More preferred.

-Oxidative polymerizable compound-
The oxidatively polymerizable compound is a compound in which an oxidative polymerization reaction proceeds by a reaction with oxygen in the air.
Examples of the oxidatively polymerizable compound include a phenol derivative in which an aliphatic hydrocarbon group having an ethylenic double bond is bonded to phenol, a drying oil, and a fatty acid having an aliphatic hydrocarbon group having an ethylenic double bond. Be done.
Among these, the oxidatively polymerizable compound is at least one selected from the group consisting of a phenol derivative in which an aliphatic hydrocarbon group having an ethylenic double bond is bonded to phenol, and a drying oil. preferable.

Examples of the phenol derivative include anacardic acid, anagiganic acid, perangic acid, ginkgo acid, ginkgophosphate, cardanol, cardol, methyl cardol, urushiol, thithiol, rengor, laccol and the like.

The drying oil is an oil containing a fatty acid having an aliphatic hydrocarbon group having an ethylenic double bond (palmitoleic acid, oleic acid, linoleic acid, linolenic acid, etc.).
Examples of the dry oil include flaxseed oil, tung oil, safflower oil, poppy oil, perilla oil, sesame oil, sunflower oil, safflower oil, soybean oil, rice bran oil, cottonseed oil, and sesame oil.

These oxidatively polymerizable compounds may be used alone or in combination of two or more.

The iodine value of the oxidatively polymerizable compound is preferably 130 g / 100 g or more, more preferably 170 g / 100 g or more, from the viewpoint of suppressing pen offset.
Oxidative polymerizable compounds having an iodine value of 130 g / 100 g or more include phenol derivatives such as cardanol and ursiol; flaxseed oil, tung oil, safflower oil, poppy oil, perilla oil, egoma oil, sunflower oil, saflower oil and the like. Examples include safflower oil.

From the viewpoint of suppressing pen offset, the content of the oxidatively polymerizable compound is preferably 1% by mass or more and 25% by mass or less, more preferably 1% by mass or more and 20% by mass or less, and 3% by mass with respect to the toner (toner particles). It is more preferably 15% by mass or less.

-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 malachite 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.

-Release agent-
Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester waxes such as fatty acid esters and montanic acid esters. ; And so on. The release agent is not limited to this.

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". ..

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.

-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 is a resin layer. Specifically, the shell layer preferably contains a resin having a glass transition temperature of 50 ° C. or higher from the viewpoint of suppressing toner deformation.
The glass transition temperature of the resin in the shell layer is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 50 ° C. or higher and 90 ° C. or lower, from the viewpoint of suppressing toner deformation and pressure fixability.

Examples of the resin of the coating layer include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic). N-butyl acid acid, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (eg, acrylonitrile) , Methacronitrile, 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, propylene, butadiene, etc.) Examples thereof include homopolymers of the above-mentioned monomers, and vinyl-based resins composed of copolymers in which two or more kinds of these monomers are combined.
Well-known binding resins include, for example, non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence of these.
These binder resins may be used alone or in combination of two or more.

In particular, as the resin of the coating layer, it is preferable to apply the styrene resin of the core portion from the viewpoint of suppressing deformation of the toner and pressure fixability.

The thickness of the shell layer is preferably 140 nm or more and 550 nm or less, more preferably 140 nm or more and 500 nm or less, and more preferably 140 nm or more and 400 nm or less from the viewpoint of suppressing toner deformation and fixing at low temperature.

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. If it is difficult to observe the coating layer in the cross-sectional image, it may be observed by dyeing.

(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 of the toner particles and various particle size distribution indexes were measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution was measured using ISOTON-II (manufactured by Beckman Coulter). NS.
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. taking measurement. 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 (circumferential peripheral length) / (peripheral length) [(circumferential length of a circle having the same projected area as the particle image) / (peripheral length of the particle projected image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Sysmex) that sucks and collects toner particles to be measured, forms a flat flow, and instantly emits strobe light to capture a particle image as a still image and 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. ..

Toner particles (toner) exhibit a thermoplastic behavior with respect to pressure even in an unheated state, and exhibit fluidity under a pressure of a predetermined pressure or higher. Specifically, the toner particles preferably satisfy the following formula.
Formula 1: 20 ° C. ≤ T (1 MPa) -T (10 MPa)
In Equation 1, T (1 MPa) represents the temperature at which the viscosity reaches 104 Pa · s at an applied pressure of 1 MPa measured using a flow tester, and T (10 MPa) represents the temperature measured using a flow tester. It represents the temperature at which the viscosity at pressure 10MPa becomes ¹⁰ 4 Pa · s.

The temperature difference represented by T (1 MPa) −T (10 MPa) (hereinafter, also referred to as “temperature difference ΔT”) is preferably 20 ° C. or higher, more preferably 40 ° C. or higher, further preferably 60 ° C. or higher, and 60 ° C. or higher. Is particularly preferable. When the temperature difference ΔT is 20 ° C. or higher, the plastic behavior with respect to pressure becomes sufficient and the pressure fixability is improved.
The temperature difference ΔT is preferably 120 ° C. or lower, more preferably 100 ° C. or lower. When the temperature difference ΔT is 120 ° C. or less, the toner particles are not too soft and the generation of stains on the fixing member is suppressed.

The value of T (10 MPa) is preferably 140 ° C. or lower, more preferably 130 ° C. or lower, and even more preferably 120 ° C. or lower. When the value of T (10 MPa) is 140 ° C. or lower, pressure fixing becomes easy without applying excessive pressure.
The value of T (10 MPa) is preferably 60 ° C. or higher, preferably 65 ° C. or higher, and more preferably 70 ° C. or higher. When the value of T (10 MPa) is 60 ° C. or higher, the adhesion to the recording medium is enhanced.

The temperature difference ΔT is measured by a method using a flow tester. Examples of the flow tester include a flow tester CFT-500 manufactured by Shimadzu Corporation.
The specific method for measuring the temperature difference ΔT is as follows.
Toner particles (toner) are compressed and solidified to prepare a pellet-shaped sample. Conditions under which the prepared sample was set in a flow tester, the measurement temperature was gradually heated from 50 ° C. in the range of 50 ° C. or higher and 150 ° C. or lower (+ 1 ° C./min heating rate), and a specified extrusion pressure was applied. Below, the viscosity of the sample is measured. The applied pressure is fixed at 1 MPa, and the viscosity with respect to the temperature at 1 MPa is measured. From the graph of the resulting viscosity, at an applied pressure 1MPa to determine the temperature T (1MPa) of when it comes to ¹⁰ 4 Pa · s. T (10 MPa) is determined by the same method as T (1 MPa) except that the applied pressure of 1 MPa is set to 10 MPa. The temperature difference ΔT (T (1 MPa) −T (10 MPa)) is calculated by taking a difference from the obtained T (1 MPa) and T (10 MPa).

[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 the 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 external additive include resin particles (resin particles such as polystyrene, polymethylmethacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, and fluoropolymers). Particles) and the like.

The amount of the external additive added is, for example, preferably 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 having the core-shell structure having the above structure are produced by the aggregation and coalescence method,
A step of preparing a resin particle dispersion liquid for a core portion in which resin particles for a core portion, which is a binding resin for the core portion, are dispersed (a resin particle dispersion liquid preparation step for the core portion);
A step of preparing a resin particle dispersion liquid for the shell layer in which resin particles for the shell layer to be the resin of the shell layer are dispersed (a resin particle dispersion liquid preparation step for the shell layer) and
In the core resin particle dispersion (in a dispersion mixed with other particle dispersions such as a colorant and a mold release agent as needed), the core resin particles (if necessary, other particles are mixed). With the step of agglomerating (particles) to form the first agglomerated particles (first agglomerated particle forming step);
The first agglomerated particle dispersion liquid in which the first agglomerated particles are dispersed and the resin particle dispersion liquid for the shell layer are mixed, and the first agglomerated particles are agglomerated so as to adhere the resin particles for the shell layer to the surface of the first agglomerated particles. 2 A step of forming agglomerated particles (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);
It is preferable to produce toner particles through the above.

Then, as the resin particle dispersion liquid for the core portion, styrene resin particles in which a plurality of (meth) acrylic acid ester resin domains are dispersed inside (that is, styrene resin is used as a base material, and (meth) acrylic acid ester is contained in the base material. A resin particle dispersion liquid in which (resin particles in which a plurality of resin domains are dispersed) is dispersed is used.
On the other hand, as the resin particles for the shell layer, a resin particle dispersion liquid in which the resin particles having a glass transition temperature of 50 ° C. or higher are dispersed is used.

Here, the oxidatively polymerizable compound is added to the dispersion liquid in any of the above steps. However, since the oxidatively polymerizable compound may be contained in the core portion, it may be added to the resin particle dispersion liquid in the resin particle dispersion liquid preparation step for the core portion, or it may be added to the resin particle dispersion liquid in the first agglomerated particle forming step before aggregation. It may be added to the dispersion.

Hereinafter, details of each step of the aggregation and coalescence method will be described. In the following description, a method of obtaining toner particles containing a colorant and a mold release agent will be described, but the colorant and the mold release agent are 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, a resin particle dispersion for the shell layer, a colorant particle dispersion, and a release agent particle dispersion are prepared.
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 for the core portion is prepared, for example, as follows. First, among the core resin (core binding resin), the styrene resin particles are dispersed in the dispersion medium by a surfactant.

Examples of the dispersion medium used for the styrene 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 styrene 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 styrene 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 an aqueous medium in the form of particles.

Next, components such as a monomer for synthesizing the (meth) acrylic acid ester resin and a polymerization initiator are added to the dispersion liquid in which the styrene resin particles are dispersed. Then, the dispersion liquid is stirred. This stirring is performed for a long time in the range of 1 hour or more and 15 hours or less, for example.
Then, the styrene resin particles are impregnated with components such as a monomer for synthesizing the (meth) acrylic acid ester resin and a polymerization initiator. In that state, a monomer for synthesizing a (meth) acrylic acid ester resin is polymerized.
Then, styrene resin particles in which a plurality of (meth) acrylic acid ester resin domains are dispersed inside (that is, resin particles in which a styrene resin is used as a base material and a plurality of (meth) acrylic acid ester resin domains are dispersed in the base material). ) Is dispersed to obtain a resin particle dispersion. Then, this resin particle dispersion liquid is used as the resin particle dispersion liquid for the core portion.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion liquid for the core portion 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 0.1 μm or more and 0.6 μm or less. Is more preferable.
The volume average particle size of the resin particle dispersion for the core is divided into particle size ranges (channels) using the particle size distribution obtained by measurement with a laser diffraction type particle size distribution measuring device (for example, LA-700 manufactured by Horiba Seisakusho). ), The cumulative distribution of the volume is drawn from the small particle size side, and the particle size that is 50% of the total particles 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 liquid for the core portion 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.

Similar to the styrene resin obtained in the process of producing the resin particle dispersion liquid for the core portion, the resin particle dispersion liquid for the shell portion, the colorant dispersion liquid, and the release agent particle dispersion liquid are also prepared. Further, the dispersion medium, the dispersion method, the volume average particle diameter of the particles, and the content of the particles in the resin particle dispersion liquid for the core portion are the same in the colorant dispersion liquid and the release agent particle dispersion liquid.

-First aggregate particle formation step-
Next, the resin particle dispersion liquid for the core portion and the colorant dispersion liquid are mixed.
Then, in the mixed dispersion liquid, the first resin particles for the core portion, the colorant particles, and the release agent particle dispersion liquid, which have a target diameter by hetero-aggregating the resin particles for the core portion and the colorant particles, are contained. Form 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. Heat the resin particles to a temperature close to the glass transition temperature (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.

Examples of the flocculant include a surfactant having a polarity opposite to that of the surfactant contained in the mixed dispersion, such as an inorganic metal salt and a divalent or higher valent metal complex. When a metal complex is used as the flocculant, the amount of the flocculant used is reduced and the charging characteristics are improved.
Along with the flocculant, an additive that forms a complex or similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride and aluminum sulfate; and inorganic metal salts such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide. Polymer; and the like.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartrate acid, citric acid and gluconic acid; aminocarboxylic acids such as iminodiacetic 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 and the resin particle dispersion liquid for the shell layer are further mixed.

Then, in the mixed dispersion liquid, the resin particles for the shell layer are heteroaggregated so as to adhere to the surface of the first aggregated particles to form the second aggregated particles having a diameter close to the target toner particle diameter.

Specifically, for example, in the first agglomerated particle forming step, when the first agglomerated particles reach the target particle size, the resin particle dispersion liquid for the shell layer is mixed with the first agglomerated particle dispersion liquid. Next, this 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, at 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 having a glass transition temperature of 50 ° C. or higher are dispersed. To form the third agglomerated particles by further mixing and aggregating the resin particles so as to further adhere to the surface of the second agglomerated particles, and to the third agglomerated particle dispersion liquid in which the third agglomerated particles are dispersed. The toner particles may be produced through the steps of forming the toner particles by fusing and coalescing the third agglomerated particles.

After the 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-flow 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 vibration sieving machine, 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; a porous magnetic powder is impregnated with 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 polycarbonate, 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 static charge 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.

Here, in the image forming apparatus according to the present embodiment, the fixing means includes means for fixing the toner image by the pressure fixing toner on the recording medium by the pressure between the pair of fixing members (roll / roll, belt / roll). Be done. The fixing means may additionally have a heating source for heating the toner image by the pressure fixing toner for the purpose of improving the pressure fixing property. However, the fixing means may be a device that does not have a heating source (that is, does not heat) and fixes only by pressure.
The fact that there is no heating source (that is, without heating) does not mean that the temperature inside the machine is prevented from becoming higher than the ambient temperature due to heat generated by power other than the fixing means.

In the fixing means, the fixing pressure is preferably 1.5 MPa or more and 10 MPa or less, preferably 2 MPa or more and 8 MPa or less, and more preferably 3 MPa or more and 7 MPa or less.
When the fixing pressure is 1.5 MPa or more, sufficient fixability can be easily obtained. Further, when the fixing pressure is 10 MPa or less, image stains, fixing roll contamination, paper wrapping, and recording medium after fixing due to offset (current state in which a part of the toner image is transferred to the fixing member) occur. Curl (a phenomenon in which the recording medium bends) is easily suppressed.

The fixing pressure means the maximum fixing pressure at the time of pressure fixing.
Here, the pressure distribution between the pair of fixing members can be measured by a commercially available pressure distribution measuring sensor. Specifically, it can be measured by a pressure measuring system between rollers manufactured by Kamata Industry Co., Ltd. The maximum pressure at the time of pressure fixing represents the maximum value in the change in pressure from the inlet to the outlet of the contact portion (nip) of the pair of fixing members in the traveling direction of the recording medium.

When heating is also performed during fixing, the fixing temperature is preferably 15 ° C. or higher and 50 ° C. or lower, more preferably 15 ° C. or higher and 45 ° C. or lower, and further preferably 15 ° C. or higher and 40 ° C. or lower. When the fixing temperature is within the above range, good fixing property can be obtained, which is preferable.

As the fixing member, for example, a conventionally known fixing member is appropriately selected and used within a range in which the fixing pressure in the above range can be applied to the toner image.
For example, among the fixing members, the fixing member on the side that comes into contact with the toner image is a resin such as a fluorine-based resin (for example, Teflon (registered trademark)), a silicon-based resin, or a perfluoroalkylate resin on a cylindrical core metal. Examples include fixing rolls coated with a layer. Further, in order to obtain a high fixing pressure, a fixing roll having a base material made of SUS is suitable.

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.

Here, as the cleaning means, for example, a means of a method of cleaning the surface of the image holder with a cleaning blade, a cleaning brush, or the like can be mentioned.
However, in cleaning with a cleaning blade, the pressure fixing toner remaining on the surface of the image holder may be plasticized by the pressure of the cleaning blade and adhere to the surface of the image holder in the form of a film. Therefore, the cleaning means is preferably a means of a method of cleaning the surface of the image holder with a cleaning brush having less stress on each pressure fixing toner.
Examples of the cleaning brush include a fixed brush such as a brush and a rotating brush in which fibers are arranged in a cylindrical shape. There is also a conductive brush that uses conductive fibers and electrostatically cleans the toner by applying a voltage.

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 type first to output an image 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 figure 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) for forming an electrostatic charge image (an example of a static charge image forming means) 3, a developing device (an example of a developing means) for developing a static charge image by supplying a charged toner to the static charge image, and developing the 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 static 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 photosensitizer 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 a 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 that 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 multiplex transferred. NS.

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 has a (-) polarity that is the same as the polarity (-) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, 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 copying machines, 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 ejection 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 these Examples. In addition, "part" and "%" indicating an amount are based on mass unless otherwise specified.

<Preparation of resin particles for core part>
(Preparation of resin particle dispersion liquid (A1) for core part)
-Styrene: 450 parts-n-Butyl acrylate: 135 parts-Acrylic acid: 12 parts-Dodecanethiol: 9 parts The above components were mixed and dissolved to prepare a solution.
On the other hand, 10 parts of anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 250 parts of ion-exchanged water, the solution was added, dispersed in a flask, and emulsified (monomer emulsified liquid A).
Further, 1 part of the same anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 555 parts of ion-exchanged water and charged into a polymerization flask.
A reflux tube was placed in the polymerization flask, and the polymerization flask was heated to 75 ° C. in a water bath and held while slowly stirring while injecting nitrogen.
After dissolving 9 parts of ammonium persulfate in 43 parts of ion-exchanged water and dropping it into a polymerization flask over 20 minutes via a metering pump, the monomeric emulsion A was added over 200 minutes via a metering pump. Dropped.
Then, the polymerization flask was held at 75 ° C. for 3 hours while continuing stirring to complete the first-stage polymerization. As a result, a resin particle dispersion (A1) precursor for the core portion having a volume average particle size of 190 nm, a glass transition temperature of 53 ° C., and a weight average molecular weight of 33,000 was obtained.
Next, after the temperature was lowered to room temperature, 600 parts of 2-ethylhexyl acrylate and 850 parts of ion-exchanged water were added to the polymerization flask, and the mixture was slowly stirred for 2 hours. Then, the temperature was raised to 70 ° C. while continuing stirring, and 4.5 parts of ammonium persulfate was added dropwise over 20 minutes via a metering pump with 110 parts of ion-exchanged water. Then, the polymerization was completed by holding for 3 hours while continuing stirring. Through the above steps, a resin particle dispersion liquid (A1) for a core portion having a volume average particle size of 260 nm, a weight average molecular weight of 200,000, and a solid content of 33% was obtained.

The resin particles of the obtained resin particle dispersion for the core portion were dried, and a sample was prepared in which the dried resin particles were embedded in an epoxy resin. Then, the sample was cut with a diamond knife to prepare a cross-sectional section of the resin particles. Then, the cut surface of the sample was stained with ruthenium tetroxide vapor, and then confirmed by observation with a transmission electron microscope. As a result of observing the cross section of the resin particles, it was confirmed that the resin particles have a configuration in which a plurality of domains of the low Tg (meth) acrylic acid ester resin are dispersed in the high Tg styrene resin as the base material.
Further, when the glass transition temperature Tg behavior of the dried resin particles was analyzed from -150 ° C by a differential scanning calorimeter (DSC) manufactured by Shimadzu Corporation, the glass was made of low Tg (meth) acrylic acid ester resin at -70 ° C. A transition was observed. In addition, a glass transition due to a high Tg styrene resin was observed at 53 ° C (glass transition temperature difference: 123 ° C).

(Preparation of resin particle dispersion liquid (A2) for core part)
Similar to the resin particle dispersion for the core (A1), except that 600 g of n-butyl acrylate was used instead of 600 parts of 2-ethylhexyl acrylate, the core had a volume average particle size of 265 nm and a solid content of 33%. Resin particle dispersion liquid (A2) for use was obtained.
Regarding the resin particles of the obtained core resin particle dispersion liquid, the cross-sectional observation of the resin particles was carried out in the same manner as in the core resin particle dispersion liquid (A1). It was confirmed that the configuration was such that a plurality of domains of the low Tg (meth) acrylic acid ester resin were dispersed therein.
Further, when the glass transition temperature Tg behavior of the dried resin particles was analyzed from -150 ° C by a differential scanning calorimeter (DSC) manufactured by Shimadzu Corporation, the glass with a low Tg (meth) acrylic acid ester resin was analyzed at -55 ° C. A transition was observed. In addition, a glass transition due to a high Tg styrene resin was observed at 53 ° C (glass transition temperature difference: 108 ° C).

(Preparation of resin particle dispersion liquid (A3) for core part)
For core parts with a volume average particle size of 268 nm and a solid content of 33%, similar to the resin particle dispersion for core parts (A1), except that 600 g of ethyl acrylate was used instead of 600 parts of 2-ethylhexyl acrylate. A resin particle dispersion liquid (A2) was obtained.
Regarding the resin particles of the obtained core resin particle dispersion liquid, the cross-sectional observation of the resin particles was carried out in the same manner as in the core resin particle dispersion liquid (A1). It was confirmed that the configuration was such that a plurality of domains of the low Tg (meth) acrylic acid ester resin were dispersed therein.
Further, when the glass transition temperature Tg behavior of the dried resin particles was analyzed from -150 ° C by a differential scanning calorimeter (DSC) manufactured by Shimadzu Corporation, the glass with a low Tg (meth) acrylic acid ester resin was analyzed at -20 ° C. A transition was observed. In addition, a glass transition due to a high Tg styrene resin was observed at 53 ° C (glass transition temperature difference: 73 ° C).

(Preparation of resin particle dispersion liquid (A4) for core part)
-Styrene: 450 parts-n-Butyl acrylate: 135 parts-Acrylic acid: 12 parts-Dodecane thiol: 9 parts-Allyl methacrylate 20 parts The above components were mixed and dissolved to prepare a solution.
On the other hand, 10 parts of anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 250 parts of ion-exchanged water, the solution was added, dispersed in a flask, and emulsified (monomer emulsified liquid A).
Further, 1 part of the same anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 555 parts of ion-exchanged water and charged into a polymerization flask.
A reflux tube was placed in the polymerization flask, and the polymerization flask was heated to 75 ° C. in a water bath and held while slowly stirring while injecting nitrogen.
After dissolving 9 parts of ammonium persulfate in 43 parts of ion-exchanged water and dropping it into a polymerization flask over 20 minutes via a metering pump, the monomeric emulsion A was added over 200 minutes via a metering pump. Dropped.
Then, the polymerization flask was held at 75 ° C. for 3 hours while continuing stirring to complete the first-stage polymerization. As a result, a resin particle dispersion (A1) precursor for the core portion having a volume average particle size of 190 nm, a glass transition temperature of 58 ° C., and a weight average molecular weight of 33,000 was obtained.
Next, after the temperature was lowered to room temperature, 600 parts of 2-ethylhexyl acrylate and 850 parts of ion-exchanged water were added to the polymerization flask, and the mixture was slowly stirred for 2 hours. Then, the temperature was raised to 70 ° C. while continuing stirring, and 4.5 parts of ammonium persulfate was added dropwise over 20 minutes via a metering pump with 110 parts of ion-exchanged water. Then, the polymerization was completed by holding for 3 hours while continuing stirring. Through the above steps, a resin particle dispersion liquid (A4) for a core portion having a volume average particle size of 260 nm, a weight average molecular weight of 180,000, and a solid content of 33% was obtained.
Regarding the resin particles of the obtained core resin particle dispersion liquid, the cross-sectional observation of the resin particles was carried out in the same manner as in the core resin particle dispersion liquid (A1). It was confirmed that the configuration was such that a plurality of domains of the low Tg (meth) acrylic acid ester resin were dispersed therein.
Further, when the glass transition temperature Tg behavior of the dried resin particles was analyzed from -150 ° C by a differential scanning calorimeter (DSC) manufactured by Shimadzu Corporation, the glass was made of low Tg (meth) acrylic acid ester resin at -70 ° C. A transition was observed. In addition, a glass transition due to a high Tg styrene resin was observed at 56 ° C (glass transition temperature difference: 126 ° C).

(Preparation of resin particle dispersion liquid (A5) for core part)
Similar to the resin particle dispersion for the core part (A1), the volume average particle size was 250 nm, except that 600 parts of 2-ethylhexyl acrylate and 20 parts of allyl methacrylate were used instead of 600 parts of 2-ethylhexyl acrylate. A resin particle dispersion liquid (A2) for a core portion having a solid content of 33% was obtained.
Regarding the resin particles of the obtained core resin particle dispersion liquid, the cross-sectional observation of the resin particles was carried out in the same manner as in the core resin particle dispersion liquid (A1). It was confirmed that the configuration was such that a plurality of domains of the low Tg (meth) acrylic acid ester resin were dispersed therein.
Further, when the glass transition temperature Tg behavior of the dried resin particles was analyzed from -150 ° C by a differential scanning calorimeter (DSC) manufactured by Shimadzu Corporation, the glass was made of a low Tg (meth) acrylic acid ester resin at -50 ° C. A transition was observed. In addition, a glass transition due to a high Tg styrene resin was observed at 53 ° C (glass transition temperature difference: 103 ° C).

<Preparation of resin particle dispersion for shell>
(Preparation of resin particle dispersion liquid (B1) for shell part)
-Styrene: 450 parts-n-Butyl acrylate: 135 parts-Allyl methacrylate: 18 parts-Acrylic acid: 12 parts-Dodecanethiol: 9 parts The above components were mixed and dissolved to prepare a solution.
On the other hand, 10 parts of anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 250 parts of ion-exchanged water, the solution was added, dispersed in a flask, and emulsified (monomer emulsified liquid A).
Further, 1 part of the same anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 555 parts of ion-exchanged water and charged into a polymerization flask.
A reflux tube was placed in the polymerization flask, and the polymerization flask was heated to 75 ° C. in a water bath and held while slowly stirring while injecting nitrogen.
After dissolving 9 parts of ammonium persulfate in 43 parts of ion-exchanged water and dropping it into a polymerization flask over 20 minutes via a metering pump, the monomeric emulsion A was added over 200 minutes via a metering pump. Dropped.
Then, the polymerization flask was held at 75 ° C. for 3 hours while continuing stirring to complete the first-stage polymerization. As a result, a resin particle dispersion liquid (B1) for a shell portion having a volume average particle size of 190 nm, a glass transition temperature of 53 ° C., a weight average molecular weight of 33,000, and a solid content of 42% was obtained.

(Preparation of resin particle dispersion liquid (B2) for shell part)
-Styrene: 450 parts-n-Butyl acrylate: 90 parts-Acrylic acid: 12 parts-Dodecanethiol: 9 parts The above components were mixed and dissolved to prepare a solution.
On the other hand, 10 parts of anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 250 parts of ion-exchanged water, the solution was added, dispersed in a flask, and emulsified (monomer emulsified liquid A).
Further, 1 part of the same anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 555 parts of ion-exchanged water and charged into a polymerization flask.
A reflux tube was placed in the polymerization flask, and the polymerization flask was heated to 75 ° C. in a water bath and held while slowly stirring while injecting nitrogen.
After dissolving 9 parts of ammonium persulfate in 43 parts of ion-exchanged water and dropping it into a polymerization flask over 20 minutes via a metering pump, the monomeric emulsion A was added over 200 minutes via a metering pump. Dropped.
Then, the polymerization flask was held at 75 ° C. for 3 hours while continuing stirring to complete the first-stage polymerization. As a result, a resin particle dispersion liquid (B2) for a shell portion having a volume average particle diameter of 190 nm, a glass transition temperature of 85 ° C., a weight average molecular weight of 36,000, and a solid content of 42% was obtained.

(Preparation of resin particle dispersion liquid (B3) for shell part)
A shell having a volume average particle size of 200 nm, a glass transition temperature of 62 ° C., a weight average molecular weight of Mw38000, and a solid content of 42% in the same manner as the resin particle dispersion liquid (B1) for the shell part except that 37 parts of allyl methacrylate was used. A resin particle dispersion liquid (B3) for parts was obtained.

(Preparation of resin particle dispersion liquid (B4) for shell part)
-Styrene: 450 parts-n-Butyl acrylate: 150 parts-Acrylic acid: 12 parts-Dodecane thiol: 9 parts The above components were mixed and dissolved to prepare a solution.
On the other hand, 10 parts of anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 250 parts of ion-exchanged water, the solution was added, dispersed in a flask, and emulsified (monomer emulsified liquid A).
Further, 1 part of the same anionic surfactant (DOWFAX2A1 manufactured by Dow Chemical Co., Ltd.) was dissolved in 555 parts of ion-exchanged water and charged into a polymerization flask.
A reflux tube was placed in the polymerization flask, and the polymerization flask was heated to 75 ° C. in a water bath and held while slowly stirring while injecting nitrogen.
After dissolving 9 parts of ammonium persulfate in 43 parts of ion-exchanged water and dropping it into a polymerization flask over 20 minutes via a metering pump, the monomeric emulsion A was added over 200 minutes via a metering pump. Dropped.
Then, the polymerization flask was held at 75 ° C. for 3 hours while continuing stirring to complete the first-stage polymerization. As a result, a resin particle dispersion liquid (B4) for a shell portion having a volume average particle size of 190 nm, a glass transition temperature of 49 ° C., a weight average molecular weight of 31,000, and a solid content of 40% was obtained.

<Preparation of colorant particle dispersion>
-Cyan pigment: 1000 parts (manufactured by Dainichiseika Co., Ltd., Pigment Blue 15: 3 (copper phthalocyanine)
-Anionic surfactant: 15 parts (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen R)
-Ion-exchanged water: 9000 parts The above components are mixed and dispersed for 1 hour using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Limited, HJP30006) to disperse a colorant (cyan pigment). A colorant particle dispersion was prepared. The volume average particle size of the colorant (cyan pigment) in the colorant particle dispersion was 160 nm, and the solid content concentration was 20%.

<Preparation of mold release agent particle dispersion>
-Polyethylene wax: 50 parts (manufactured by Toyo Adre Co., Ltd., PW725, melting temperature: 100 ° C)
-Anionic surfactant: 0.5 parts (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK)
-Ion-exchanged water: 200 parts The above components were mixed, heated to 95 ° C., and dispersed using a homogenizer (Ultratarax T50 manufactured by IKA). Then, it was dispersed with a manton gorin high-pressure homogenizer (manufactured by Gorlin) to prepare a release agent particle dispersion (solid content concentration: 20%) in which the release agent was dispersed. The volume average particle size of the release agent was 230 nm.

<Example 1>
-Resin particle dispersion for core (A1): 504 parts-Colorant particle dispersion: 63 parts-Ion-exchanged water: 710 parts-Anionic surfactant: 1 part (Dowfax2A1 manufactured by Dow Chemical Co., Ltd.)
-Oxidation-polymerizable compound (linseed oil): 25 parts As a material for forming the core part, the above components were placed in a 3 liter reaction vessel equipped with a thermometer, a pH meter and a stirrer, and 1.0 at a temperature of 25 ° C. After adding% nitric acid to adjust the pH to 3.0, add 23 parts of the prepared aluminum sulfate aqueous solution while dispersing at 5,000 rpm with a homogenizer (manufactured by IKA Japan Co., Ltd .: Ultratarax T50). Dispersed for 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. After the temperature exceeded ° C., the temperature was raised at a heating rate of 0.05 ° C./min, and the particle size was measured every 10 minutes with a multisizer II (aperture diameter: 50 μm, manufactured by Coulter). The temperature was maintained when the volume average particle diameter reached 5.0 μm, and 170 parts of the resin particle dispersion liquid (B1) for the shell portion was added as a material for forming the shell portion over 5 minutes. After holding for 30 minutes, the pH was adjusted to 9.0 using a 1% aqueous sodium hydroxide solution. Then, while adjusting the pH to 9.0 at every 5 ° C., the temperature was raised to 90 ° C. at a heating rate of 1 ° C./min and maintained at 98 ° C. When the particle shape and surface properties were observed with an optical microscope and a scanning electron microscope (FE-SEM), the coalescence of the particles was confirmed at 10.0 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 ejector. The toner remaining on the filter paper was crushed as finely as possible by hand, poured into ion-exchanged water at a temperature of 30 ° C., which was 10 times the amount of the toner, and stirred and mixed for 30 minutes. Subsequently, the toner is filtered under reduced pressure with an ejector, the toner remaining on the filter paper is crushed as finely as possible by hand, poured into ion-exchanged water at a temperature of 30 ° C., which is 10 times the amount of toner, stirred and mixed for 30 minutes, and then the pressure is reduced again with an ejector. It was filtered 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 toner was washed. The washed toner was finely crushed with a wet dry granulator (comil) and then vacuum dried in an oven at 35 ° C. for 36 hours to obtain toner particles. The obtained toner particles had a volume average particle size of 5.8 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 11, Comparative Example 1>
The toner of Example 1 except that the type and number of core-forming materials (core resin particles, oxidatively polymerizable compound) and shell-forming material (shell-forming resin particle dispersion) were changed according to Table 1. Toners of each example were obtained in the same manner as in the above.

<Measurement>
For the toners obtained in each example, the presence or absence of a sea-island structure, the major axis of the island portion, and the thickness of the shell layer were measured according to the methods described above.
It was confirmed that the toner of the example had a sea-island structure composed of a sea part containing a high Tg styrene resin and an island part containing a low Tg (meth) acrylic acid ester resin.

<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 for each example. 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 resin coating layer forming solution. 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.

(Preparation of evaluation machine)
The developer of each example was housed in the developing apparatus of the DocuPrint C2425 modified machine manufactured by Fuji Xerox Co., Ltd. In this modified machine, the 2-roll type fixing machine was modified so that the maximum fixing pressure was 5 MPa (50 kgf / cm ² ), and the process speed was adjusted to 180 mm / sec. The modified machine does not have a heating source in the fixing device. In addition, a brush cleaner for cleaning the transfer residual toner on the photoconductor was provided.
This modified machine was used as an evaluation machine, and the following evaluation was carried out. The results are shown in Table 1.

(Evaluation of toner deformation)
Using an evaluation machine, A4 size C2 paper was used, and a solid image having a toner weight of 4 mg / cm ² per unit area at the time of a solid image and an image density of 100% was passed through, and 100 sheets were continuously printed. Then, the developer was collected, the shape of the toner particles was observed with a scanning electron microscope (SEM), and the toner particles were compared with the unused toner particles for sensory evaluation. Then, the deformation of the toner was evaluated according to the following evaluation criteria.
-Evaluation criteria-
A: A change in shape was observed in less than 5% compared to the unused toner.
B: Shape change or crushing is observed in the toner of 5% or more and 20% or less.
C: Shape change or crushing is observed in toner exceeding 20%. Unacceptable in actual use.

(Evaluation of pressure fixability)
Using an evaluation machine, A4 size C2 paper was used, and a solid image having a toner weight of 4 mg / cm ² per unit area at the time of a solid image and an image density of 100% was passed through, and 100 sheets were continuously printed. Then, cloth rubbing was performed, and the image density before and after rubbing was measured using a spectroscopic densitometer (X-Rite). The closer the image density ratio is to 1.0, the stronger the fixing strength and the better the pressure fixing property. Then, the pressure fixability was evaluated according to the following evaluation criteria.
-Evaluation criteria-
A: Image density ratio is 0.9 or more and B: Image density ratio is 0.8 or more and less than 0.9 C: Image density ratio is 0.7 or more and less than 0.8 D: Image density ratio is less than 0.7. Unacceptable in actual use.

(Evaluation of pen offset (set-off of fixed image))
Using an evaluation machine, a solid image with an image density of 50% is continuously printed on one side of ^{A4 size paper (thin paper with a basis weight of 52 g / m 2) under a high temperature environment (temperature 40 ° C., humidity 50% RH environment).} One sheet was output. Another A4 paper was superposed on the image forming surface of the A4 paper on which the image was formed. Then, in the stacked state, characters (ABC) were drawn on the surface of another A4 paper using a pencil.
Then, after peeling off the other A4 paper and the A4 paper on which the image was formed, the back surface of the other A4 paper was observed, and the pen offset was evaluated according to the following evaluation criteria.
-Evaluation criteria-
A: No set-off of the fixed image was confirmed, and a good image was obtained.
B: A slight set-off of the fixed image occurs along the line drawn with a pencil, but there is no image defect and a good image is obtained.
C: There is a slight set-off of the fixed image along the line drawn with a pencil, but there is no image defect and it is acceptable in actual use.
D: Set-off of the fixed image occurs along the entire line drawn with a pencil, which is unacceptable in actual use.

The details of each example are listed below in Tables 1 and 2. In Tables 1 and 2, the abbreviations and the like are as follows.

-Remarks column-
-High Tg-Allyl: The high Tg styrene resin has an allyl group. The numerical value in parentheses indicates the content (mmol%) of the allyl group with respect to the resin.
-Low Tg-Allyl: The low Tg (meth) acrylic acid ester resin has an allyl group. The numerical value in parentheses indicates the content (mmol%) of the allyl group with respect to the resin.
-Allyl: The resin of the shell layer has an allyl group. The numerical value in parentheses indicates the content (mmol%) of the allyl group with respect to the resin.

-Column of oxidatively polymerizable compounds-
-OPC1: Linseed oil-OPC2: Safflower oil-OPC3: Urushiol-OPC4: Cardanol The numerical values in parentheses in the column of oxidatively polymerizable compounds indicate the content (mass%) of the oxidatively polymerizable compound with respect to the toner particles. ..

From the above results, it can be seen that the pen offset is suppressed in this embodiment as compared with the comparative example.
Further, it can be seen that in this embodiment, the deformation of the toner is suppressed and the pressure fixability is also good.
Further, it can be seen that the pen offset can be suppressed in the example in which the resin having an allyl group is applied as compared with the other examples.

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 electrostatic 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 (11)

Contains styrene resin, (meth) acrylic acid ester resin and oxidatively polymerizable compounds
It has a sea-island structure composed of a sea part containing the styrene resin and an island part containing the (meth) acrylic acid ester resin.
The glass transition temperature of the (meth) acrylic acid ester resin is 30 ° C. or higher lower than that of the styrene resin.
A pressure fixing toner for static charge image development in which at least one of the styrene resin and the (meth) acrylic acid ester resin is a resin using a monomer having an allyl group. The pressure-fixing toner for static charge image development according to claim 1 , wherein the (meth) acrylic acid ester-based resin is a resin using a monomer having an allyl group. A core portion containing the styrene resin, the (meth) acrylic acid ester resin, and the oxidatively polymerizable compound and having the sea-island structure, and the core portion.
A coating layer that covers the core portion and contains a resin having a glass transition temperature of 50 ° C. or higher,
The pressure fixing toner for developing an electrostatic charge image according to claim 1 or 2. The pressure-fixing toner for static charge image development according to claim 3 , wherein the resin of the coating layer is a styrene resin and a resin using a monomer having an allyl group. Claims 1 to claim that the oxidatively polymerizable compound is at least one selected from the group consisting of a phenol derivative in which an aliphatic hydrocarbon group having an ethylenic double bond is bonded to phenol, and a drying oil. The pressure fixing toner for developing an electrostatic charge image according to any one of No. 4. The pressure-fixing toner for static charge image development according to any one of claims 1 to 5 , wherein the iodine value of the oxidatively polymerizable compound is 130 g / 100 g or more. An electrostatic charge image developing agent containing the pressure fixing toner for developing an electrostatic charge image according to any one of claims 1 to 6. The pressure fixing toner for developing an electrostatic charge image according to any one of claims 1 to 6 is accommodated.
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 7 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 7 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 7.
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.

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