JP6911366B2 - Toner for static charge image development, static charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

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

In electrophotographic image formation, toner is used as an image forming material, and for example, a toner containing toner particles containing a binder resin and a colorant and an external additive added to the toner particles is used. It is widely used.

For example, Patent Document 1 states, "In the endothermic curve obtained by DSC measurement, the peak temperature of the maximum endothermic peak in the temperature range of 40 to 75 ° C. is set to A, and the toner is stored in a constant temperature bath at 40 ° C. for 72 hours. The endothermic curve obtained by at least DSC measurement is 5 ≦ BA ≦ 13 when the peak temperature of the maximum endothermic peak in the temperature range of 40 to 75 ° C. is B. ” Is disclosed.
Further, Patent Document 1 describes that the control of 5 ≦ BA ≦ 13 is controlled by the ratio of the compatible state of the crystalline polyester resin with the amorphous resin.

Japanese Unexamined Patent Publication No. 2007-072333

An object of the present invention is that a toner for static charge image development having toner particles containing an amorphous resin and a crystalline resin is faster in a high temperature and high humidity environment than in the case of satisfying the formula: 0.9> a / b. Provided is a static charge image developing toner that suppresses the occurrence of a phenomenon in which toner adheres to a film (hereinafter, also referred to as "toner filming") that occurs when an image is formed at a process speed (conveyance speed of a recording medium). That is.

The above problem is solved by the following means. That is,

The invention according to <1 > is
It has toner particles containing amorphous resin and crystalline resin, and has
When the toner particles are heated at a temperature of 50 ° C. and a humidity of 50% RH for 3 days, the area ratio a (%) of the crystalline resin present in the cross section of the toner particles before heating and the toner particles after heating Toner for static charge image development in which the relationship with the area ratio b (%) of the crystalline resin existing in the cross section of the above satisfies the formula (1): 0.9 ≦ a / b ≦ 1.0.

The invention according to <2 > is the toner for developing an electrostatic charge image according to < 1 > , wherein the toner particles contain a bright pigment.

The invention according to <3 > is
A static charge image developer containing the toner for static charge image development according to < 1 > or < 2 >.

The invention according to <4 > is
The toner for static charge image development according to <1 > or < 2 > is accommodated, and the toner is accommodated.
A toner cartridge that is attached to and detached from the image forming device.

The invention according to <5 > is
A developing means for accommodating the electrostatic charge image developing agent according to < 3 > 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 <6 > 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 < 3 > 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 <7 > 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 developing agent according to < 3 >.
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 > or 2 > , a static charge image developing toner having toner particles containing an amorphous resin and a crystalline resin is compared with the case where the formula: 0.9> a / b is satisfied. Provided are a toner for static charge image development that suppresses the occurrence of toner filming that occurs when an image is formed at a high process speed (conveyance speed of a recording medium) in a high temperature and high humidity environment.

According to the invention according to < 3 > , < 4 > , < 5 > , < 6 > , or < 7 > , in a toner for static charge image development having toner particles containing an amorphous resin and a crystalline resin, the formula is used. : Toner fill that occurs when an image is formed at a high process speed (conveyance speed of recording medium) in a high temperature and high humidity environment compared to the case where a toner for static charge image development satisfying 0.9> a / b is applied. An electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method for suppressing the occurrence of ming is provided.

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

Hereinafter, the present invention will be described in detail by showing an embodiment as an example.

<Toner for static charge image development>
The toner for static charge image development according to the present embodiment (also simply referred to as “toner”) has toner particles containing an amorphous resin and a crystalline resin. When the toner particles are heated at a temperature of 50 ° C. and a humidity of 50% RH for 3 days, the area ratio a (%) of the crystalline resin existing in the cross section of the toner particles before heating and the cross section of the toner particles after heating The relationship with the area ratio b (%) of the crystalline resin existing in the above satisfies the formula (1): 0.9 ≦ a / b ≦ 1.0.
The area ratio of the crystalline resin indicates the area ratio of the crystalline resin that is phase-separated from the amorphous resin and is distinguished from the amorphous resin by ruthenium tetroxide dyeing described later.

According to the above configuration, the toner according to the present embodiment has a high temperature and high humidity environment (for example, an environment of a temperature of 35 ° C. and a humidity of 85% RH) and a high process speed (for example, a transport speed of a recording medium of 445 mm / sec or more). It suppresses the occurrence of toner filming (a phenomenon in which toner sticks in a film) that occurs when an image is formed. The reason is presumed as follows.

In recent years, in response to the demand for energy saving, a technique for improving low temperature fixability of toner has been known for the purpose of reducing power consumption when fixing a toner image. As one of them, a toner in which toner particles contain a crystalline resin together with an amorphous resin is known. On the other hand, from the viewpoint of ensuring heat resistance, a technique for forming an appropriately phase-separated structure (sea-island structure) of an amorphous resin and a crystalline resin in the toner particles is known (for example, Patent Document 1). etc).

However, even if the amorphous resin and the crystalline resin are appropriately phase-separated, if the amorphous resin and the crystalline resin are compatible with each other, the environment is high temperature and high humidity (for example, temperature 35 ° C., humidity). When an image is formed at a high process speed (for example, a transport speed of a recording medium of 445 mm / sec or more) under an environment of 85% RH), for example, the surface of an image holder, charging means (for example, charging roll), intermediate transfer. A phenomenon (toner forming) in which toner adheres to the surface of a body (for example, an intermediate belt) in the form of a film may occur. When toner filming occurs, it often appears as streaky image defects in the image.
When an image is formed in a high temperature and high humidity environment at a high process speed, a recording medium having a normal process speed (224 mm / sec or more and 308 mm / sec or less) in a room temperature environment (for example, an environment of a temperature of 22 ° C. and a humidity of 55% RH) is used. Compared to when an image is formed at (conveyance speed), the toner is subjected to stronger heat or mechanical load on the surface of the image holder, charging means (for example, charging roll), intermediate transfer body (for example, intermediate belt), etc. , It is considered that toner filming is likely to occur because the toner particles are easily deformed or broken.

Therefore, in the toner according to the present embodiment, the amount of phase separation of the crystalline resin with respect to the amorphous resin is large in the toner particles, and the amount of compatibility of the crystalline resin is reduced. That is, when the toner particles are heated at a temperature of 50 ° C. and a humidity of 50% RH for 3 days, the area ratio a (%) of the crystalline resin existing in the cross section of the toner particles before heating and the cross section of the toner particles after heating The relationship with the area ratio b (%) of the crystalline resin present in is satisfied with the formula (1): 0.9 ≦ a / b ≦ 1.0.

Here, when the toner particles are heated at a temperature of 50 ° C. and a humidity of 50% RH for 3 days, phase separation between the amorphous resin and the crystalline resin proceeds in the toner particles, and the crystalline resin with respect to the amorphous resin The amount of compatibility is zero or close to zero. Then, as the phase separation progresses from the compatible state, the area ratio of the crystalline resin present in the cross section of the toner particles increases.
That is, the relationship between the area ratio a (%) of the crystalline resin present in the cross section of the toner particles before heating and the area ratio b (%) of the crystalline resin existing in the cross section of the toner particles after heating is expressed by the formula. (1): Satisfying 0.9 ≦ a / b ≦ 1.0 means that the area ratio of the crystalline resin present in the cross section of the toner particles does not change or is small due to heating. This means that in the toner particles before heating, the phase separation amount of the crystalline resin with respect to the amorphous resin is large, and the phase separation amount of the crystalline resin is zero or reduced. In addition, "a / b" = 1.0 means a state in which the compatible amount of the crystalline resin is zero in the toner particles.

On the other hand, among the toner particles, the larger the phase separation amount of the crystalline resin with respect to the amorphous resin (that is, the amount of islands in the sea-island structure), the higher the strength of the toner particles and the less likely it is that the toner particles are deformed or damaged. Become. It is considered that this is because the filler effect (filler effect) of the crystalline resin constituting the island portion of the sea-island structure is enhanced.

That is, a state in which "a / b" in the above formula (1) is set to 0.9 or more and the amount of phase separation of the crystalline resin from the amorphous resin is increased (a state in which the amount of islands in the sea-island structure is increased). ), Since the filler effect (filler effect) of the crystalline resin is enhanced, the process speed is high (for example, 445 mm /) under a high temperature and high humidity environment (for example, an environment of a temperature of 35 ° C. and a humidity of 85% RH). An image is formed at a recording medium transport speed of sec or more), and a strong heat or mechanical load on the toner is applied to the surface of the image holder, charging means (for example, charging roll), intermediate transfer body (for example, intermediate belt), etc. Even if the toner particles are applied, the toner particles are less likely to be deformed or damaged, and the occurrence of toner crystallization is suppressed.

From the above, it is presumed that the toner according to the present embodiment suppresses the occurrence of toner filming that occurs when an image is formed at a high process speed in a high temperature and high humidity environment.

For example, even if inorganic particles or organic particles having a high glass transition temperature Tg are added to the toner particles, the strength of the toner particles is improved by the filler effect, but the melt viscosity of the toner particles themselves is increased. Therefore, when image formation with a high process speed is performed, the toner particles are not completely melted at the time of fixing, resulting in poor fixing (for example, a decrease in bending strength of the image). On the other hand, in the toner according to the present embodiment, since the strength of the toner particles is increased by utilizing the filler effect of the crystalline resin, fixing defects are unlikely to occur and fixability is also ensured.

In the toner according to the present embodiment, the formula (1): 0.9 ≦ a / b ≦ 1.0 is satisfied, but from the viewpoint of suppressing the occurrence of toner filming, the formula (12): 0.92 ≦ a / b It is preferable to satisfy ≦ 1.0, and the formula (13): 0.94 ≦ a / b ≦ 1.0 is more preferable.
In addition, "a / b" can be adjusted, for example, by the cooling rate after forming the toner particles, the conditions of the annealing treatment, and the like.

Here, the toner particles are heated from an environment of a temperature of 25 ° C. and a humidity of 50% RH to a temperature of 50 ° C. and a humidity of 50% RH, and the temperature is maintained for 3 days.

On the other hand, the area ratio of the crystalline resin existing in the cross section of the toner particles is that the cross section of the toner particles is stained with ruthenium and then the cross section of the toner particles is observed with a magnified image of 30,000 times by a scanning electron microscope (SEM). Measure with.
Specifically, the toner particles are mixed with the epoxy resin and embedded to solidify the epoxy resin. The obtained solidified product is cut by an ultramicrotome device (UltracutUCT manufactured by Leica) to prepare a flaky sample having a thickness of 80 nm or more and 130 nm or less. Next, the obtained flaky sample is stained with ruthenium tetroxide in a desiccator at 30 ° C. for 3 hours. Then, an ultra-high resolution field emission scanning electron microscope (FE-SEM; S-4800 manufactured by Hitachi High-Technologies Co., Ltd.) is used to obtain a STEM observation image of the stained flaky sample in the transmission image mode. In the toner, the crystalline polyester resin and the mold release agent were judged from the contrast and the shape. In the SEM image, the ruthenium-stained crystalline resin has more double-bonded portions and is dyed with ruthenium tetraoxide as compared with the amorphous resin and the release agent. , The release agent part and the resin part other than the release agent are distinguished. That is, it is the domain in which the release agent is dyed the thinnest by ruthenium dyeing, then the crystalline resin (for example, crystalline polyester resin) is dyed, and the amorphous resin (for example, amorphous polyester resin) is dyed. It is dyed the deepest. By adjusting the contrast, it can be judged that the release agent is white, the amorphous resin is black, and the crystalline resin is a light gray color. By image analysis of the ruthenium-stained crystalline resin region, the ratio of the area of the crystalline resin region to the cross-sectional area of the toner particles is calculated. Then, the average value of the ratio obtained by performing this operation on 100 toner particles is taken as the area ratio of the crystalline resin existing in the cross section of the toner particles.

In the case of toner particles externally added with an external additive, the toner particles externally added with an external additive are targeted for heating and for measuring the area ratio of the crystalline resin.

In the toner according to the present embodiment, the toner particles have a sea-island structure of a sea part containing an amorphous resin and an island part containing a crystalline resin.
From the viewpoint of suppressing the occurrence of toner filming, the domain diameter of the island portion (that is, the domain of the crystalline resin) containing the crystalline resin is preferably 5 nm or more and 500 nm or less, and 10 nm or more and 300 nm or less in the cross section of the toner particles. Is more preferable.

The domain diameter of the island part (domain of the crystalline resin) containing the crystalline resin is the same as the area ratio of the crystalline resin, after the cross section of the toner particles is stained with ruthenium, and then the scanning electron microscope (SEM) is used. It is measured by observing the cross section of the toner particles with a magnified image of 30,000 times.
That is, in the obtained SEM image, the major axis diameter of the ruthenium-stained crystalline resin region (crystalline resin domain) is measured. This major axis diameter is measured for 50 crystalline resin domains per cross section of one toner particle. Then, the average value of the major axis diameters of the domains of the crystalline resin obtained by performing this operation on 100 toner particles is taken as the domain diameter of the crystalline resin.

Further, from the viewpoint of suppressing the occurrence of toner filming, the number of islands containing the crystalline resin (that is, the number of domains of the crystalline resin) in the cross section of the toner particles is 10 per unit area (1 μm × 1 μm). More than 200 pieces are preferable, and 20 pieces or more and 100 pieces or less are more preferable.

The number of islands containing the crystalline resin (the number of domains of the crystalline resin) is determined by scanning electron microscopy (SEM) after the cross section of the toner particles is ruthenium-stained in the same manner as the area ratio of the crystalline resin. It is measured by observing the cross section of the toner particles with a magnified image of 30,000 times.
That is, in the obtained SEM image, the number of ruthenium-stained crystalline resin regions (crystalline resin domains) in the cross section of one toner particle is counted. Then, this operation is carried out for 100 toner particles, and the average value of the number of domains of the crystalline resin per unit area (1 μm × 1 μm) is taken as the number of domains of the crystalline resin.

Hereinafter, the details of the toner according to this embodiment will be described.
The toner according to the present embodiment has, for example, toner particles and an external additive.

(Toner particles)
The toner particles include a binder resin. The toner particles may contain a colorant, a mold release agent, and other additives, if necessary.

-Bound resin-
Amorphous resin and crystalline resin are applied as the binder resin.
However, the mass ratio of the amorphous resin to the crystalline resin (amorphous resin / crystalline resin) is preferably 50/50 or more and 97/3 or less, and more preferably 70/30 or more and 93/7 or less.
The content of the entire binder resin is 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 further preferably 60% by mass or more and 85% by mass or less with respect to the toner particles. preferable.

Here, the "crystallinity" of the resin means that the resin has a clear endothermic peak instead of a stepwise endothermic change in differential scanning calorimetry (DSC) based on ASTMD3418-8. It means that the half width of the endothermic peak when measured at a heating rate of 10 (° C./min) is within 10 ° C.
On the other hand, "amorphous" of the resin means that the half width exceeds 10 ° C., shows a stepwise endothermic amount change, or does not show a clear endothermic peak.

Amorphous resin will be described.
Examples of the amorphous resin include known amorphous resins such as an amorphous polyester resin, an amorphous vinyl resin (for example, styrene / acrylic resin), an epoxy resin, a polycarbonate resin, and a polyurethane resin. Among these, amorphous polyester resin and amorphous vinyl resin (particularly styrene / acrylic resin) are preferable, and amorphous polyester resin is more preferable, from the viewpoint of low temperature fixability and chargeability of the toner.

Examples of the amorphous polyester resin include a condensed polymer of a multivalent carboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.). , Alicyclic dicarboxylic acid (eg cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), these anhydrides, or their lower grades (eg, 1 or more carbon atoms). 5 or less) Alkyl ester can be mentioned. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (eg ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (eg cyclohexanediol, cyclohexanedimethanol, etc.). Hydrogenated bisphenol A, etc.), aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.) can be mentioned. Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
The polyhydric alcohol may be used alone or in combination of two or more.

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

Here, as the amorphous polyester resin, in addition to the above-mentioned unmodified amorphous polyester resin, a modified amorphous polyester resin can also be mentioned. The modified amorphous polyester resin is an amorphous polyester resin having a bonding group other than an ester bond, and an amorphous resin in which a resin component different from the amorphous polyester resin component is covalently bonded or ionic bonded. It is a polyester resin. Examples of the modified amorphous polyester resin include an amorphous polyester resin in which a functional group such as an isocyanate group that reacts with an acid group or a hydroxyl group is introduced at the terminal, and a resin whose terminal is modified by reacting with an active hydrogen compound. Can be mentioned.

As the modified amorphous polyester resin, a urea-modified amorphous polyester resin (hereinafter, also simply referred to as “urea-modified polyester resin”) is preferable.

The urea-modified polyester resin is preferably a urea-modified polyester resin obtained by reacting an amorphous polyester resin having an isocyanate group (acrystalline polyester prepolymer) with an amine compound (at least one reaction of a cross-linking reaction and an elongation reaction). .. The urea-modified polyester resin may contain a urethane bond as well as a urea bond.

The amorphous polyester prepolymer having an isocyanate group is an amorphous polyester resin which is a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol, and is a polyvalent isocyanate in an amorphous polyester resin having active hydrogen. Examples thereof include an amorphous polyester prepolymer obtained by reacting a compound. Examples of the group having active hydrogen contained in the amorphous polyester resin include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups and the like, and alcoholic hydroxyl groups are preferable.

In the amorphous polyester prepolymer having an isocyanate group, examples of the polyvalent carboxylic acid and the polyhydric alcohol include compounds similar to the polyvalent carboxylic acid and the polyhydric alcohol described in the amorphous polyester resin.

Polyisocyanate compounds include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatics. Diisocyanate (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); aromatic aliphatic diisocyanate (α, α, α', α'-tetramethylxylylene diisocyanate, etc.); isocyanurates; Examples include those blocked with a blocking agent.
The polyisocyanate compound may be used alone or in combination of two or more.

The ratio of the polyisocyanate compound is preferably 1/1 or more and 5/1 as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the amorphous polyester prepolymer having a hydroxyl group. Hereinafter, it is more preferably 1.2 / 1 or more and 4/1 or less, and further preferably 1.5 / 1 or more and 2.5 / 1 or less.

In the amorphous polyester prepolymer having an isocyanate group, the content of the component derived from the polyvalent isocyanate compound is preferably 0.5% by mass or more and 40 mass by mass with respect to the entire amorphous polyester prepolymer having an isocyanate group. % Or less, more preferably 1% by mass or more and 30% by mass or less, still more preferably 2% by mass or more and 20% by mass or less.

The number of isocyanate groups contained in each molecule of the amorphous polyester prepolymer having an isocyanate group is preferably 1 or more on average, more preferably 1.5 or more and 3 or less on average, and further preferably 1.8 on average. More than 2.5 pieces or less.

Examples of the amine compound that reacts with the amorphous polyester prepolymer having an isocyanate group include diamine, trivalent or higher polyamine, aminoalcohol, aminomercaptan, amino acid, and a compound in which these amino groups are blocked.

Examples of the diamine include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4'diaminodiphenylmethane, etc.); alicyclic diamines (4,4'-diamino-3,3'dimethyldicyclohexylmethane, diaminecyclohexane, isophoronediamine, etc.) ); And aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like.
Examples of the triamine or higher polyamine include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of amino acids include aminopropionic acid and aminocaproic acid.
Blocking these amino groups includes amine compounds such as diamines, trivalent or higher polyamines, aminoalcohols, aminomercaptans, and amino acids, and ketimine compounds obtained from ketone compounds (acetone, methylethylketone, methylisobutylketone, etc.). Examples include oxazoline compounds.
Of these amine compounds, ketimine compounds are preferred.
The amine compound may be used alone or in combination of two or more.

The urea-modified polyester resin is an amorphous polyester resin (non-crystalline) having an isocyanate group by a terminator that terminates at least one of the crosslinking reaction and the elongation reaction (hereinafter, also referred to as “crosslinking / elongation reaction terminator”). The resin may have an adjusted molecular weight after the reaction by adjusting the reaction (at least one reaction of the cross-linking reaction and the extension reaction) with the (polyester prepolymer) and the amine compound.
Examples of the cross-linking / extension reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.) and those that block them (ketimine compounds).

The ratio of the amine compound is preferably 1 / as the equivalent ratio [NCO] / [NHx] of the isocyanate group [NCO] in the amorphous polyester prepolymer having an isocyanate group and the amino group [NHx] in the amines. It is 2 or more and 2/1 or less, more preferably 1 / 1.5 or more and 1.5 / 1 or less, and further preferably 1 / 1.2 or more and 1.2 / 1 or less.

The urea-modified polyester resin is preferably a urea-modified polyester resin obtained by reacting a polyester resin having an isocyanate group (hereinafter referred to as "polyester prepolymer") with an amine compound (at least one reaction of a cross-linking reaction and an extension reaction). .. Urethane bonds may be present in the urea-modified polyester together with the urea bonds.

Examples of the polyester prepolymer include a reaction product of a polyester having a group having active hydrogen and a polyisocyanate compound. Examples of the group having active hydrogen include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups and the like, and alcoholic hydroxyl groups are preferable. Polyisocyanate compounds include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatics. Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); aromatic aliphatic diisocyanates (α, α, α', α'-tetramethylxylylene diisocyanate, etc.); isocyanurates; polyisocyanates blocked from phenol derivatives, oximes, caprolactam, etc. Compounds blocked with an agent: include. One type of polyisocyanate compound may be used alone, or two or more types may be used in combination.

The content of the portion derived from the polyvalent isocyanate compound in the polyester prepolymer is preferably 0.5% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 30% by mass or less, based on the entire polyester prepolymer. More preferably, it is 2% by mass or more and 20% by mass or less. The average number of isocyanate groups per molecule of the polyester prepolymer is preferably 1 or more, more preferably 1.5 or more and 3 or less, and further preferably 1.8 or more and 2.5 or less.

Examples of the amine compound that reacts with the polyester prepolymer include diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, and a compound in which the amino group of these amine compounds is blocked.

Examples of the diamine include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4'diaminodiphenylmethane, etc.); alicyclic diamines (4,4'-diamino-3,3'dimethyldicyclohexylmethane, diaminecyclohexane, isophoronediamine, etc.) ); An aliphatic diamine (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.); and the like. Examples of the triamine or higher polyamine include diethylenetriamine and triethylenetetramine. Examples of the amino alcohol include ethanolamine, hydroxyethylaniline and the like. Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan. Examples of amino acids include aminopropionic acid and aminocaproic acid.
Examples of the compound in which the amino group of the amine compound is blocked include a ketimine compound and an oxazoline compound derived from the amine compound and a ketone compound (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.).
As the amine compound, a ketimine compound is preferable. One type of amine compound may be used alone, or two or more types may be used in combination.

The urea-modified polyester resin is prepared by adjusting the reaction between the polyester prepolymer and the amine compound with a terminator that terminates at least one of the cross-linking reaction and the extension reaction (hereinafter referred to as “cross-linking / extension reaction terminator”). , The resin may have an adjusted molecular weight after the reaction. Examples of the cross-linking / extension reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), compounds in which the amino group of monoamines is blocked (ketimine compounds), and the like.

The characteristics of the amorphous resin will be described.
The glass transition temperature (Tg) of the amorphous resin is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower.
The glass transition temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in JIS K 7121-1987 "Method for measuring transition temperature of plastics". It is obtained by the "external glass transition start temperature" of.

The weight average molecular weight (Mw) of the amorphous resin is preferably 5000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.
The number average molecular weight (Mn) of the amorphous resin is preferably 2000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the amorphous resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out using a Tosoh GPC / HLC-8120GPC as a measuring device, a Tosoh column / TSKgel SuperHM-M (15 cm), and a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The crystalline resin will be described.
Examples of the crystalline resin include known crystalline resins such as a crystalline polyester resin and a crystalline vinyl resin (for example, a polyalkylene resin, a long-chain alkyl (meth) acrylate resin, etc.). Among these, a crystalline polyester resin is preferable from the viewpoint of the mechanical strength of the toner and the low-temperature fixability.

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

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

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

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

The crystalline polyester resin can be obtained by a well-known manufacturing method, like, for example, an amorphous polyester.

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

The weight average molecular weight (Mw) of the crystalline resin is preferably 6,000 or more and 35,000 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 malakite green oxalate, or aclysine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black Examples thereof include various dyes such as system, polymethine type, triphenylmethane type, diphenylmethane type and thiazole type.
The colorant may be used alone or in combination of two or more.

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.

-Characteristics of toner particles, etc.-
The toner particles may be toner particles having a single layer structure, or may be toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) covering the core portion. You may.
Here, the toner particles having a core-shell structure include, for example, a core portion composed of a binder resin and, if necessary, other additives such as a colorant and a mold release agent, and a binder resin. It is preferably composed of a composed coating layer.

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

The various average particle sizes and various particle size distribution indexes of the toner particles were measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte 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. Measure. The number of particles to be sampled is 50,000.
Cumulative distribution of volume and number is drawn from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the cumulative 16% particle size is volume particle size D16v and number particle size. The particle size having D16p and a cumulative 50% is defined as the volume average particle size D50v and the cumulative number average particle size D50p, and the particle size having a cumulative number of 84% is defined as the volume particle size D84v and the number particle size D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 , and the number particle size distribution index (GSDp) is calculated as ^{(D84p / D16p) 1/2.}

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

The average circularity of the toner particles is obtained by (perimeter equivalent to a circle) / (perimeter) [(perimeter of a circle having the same projected area as the particle image) / (perimeter of the projected particle image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Cysmex) that captures a particle image as a still image by sucking and collecting toner particles to be measured, forming a flat flow, and instantly emitting strobe light, and analyzing the particle image. Obtained by FPIA-2100) 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. ..

(Glittering toner particles)
Here, the toner particles may be bright toner particles containing a bright pigment. If necessary, the brilliant toner particles may contain a colorant in addition to the brilliant pigment.
Hereinafter, the description of the components and characteristics of the brilliant toner particles having the same composition and characteristics as those of the toner particles will be omitted.

-Glittering pigment-
Examples of the brilliant pigment include pigments (brilliant pigments) that can impart a brilliant feeling such as metallic luster. Specifically, as the brilliant pigment, for example, metal powders such as aluminum (metal of Al alone), brass, bronze, nickel, stainless steel, zinc and the like; mica coated with titanium oxide, yellow iron oxide and the like; barium sulfate, layered silicate. Coated flaky inorganic crystal substrate such as acid salt, layered aluminum silicate; monocrystal plate-shaped titanium oxide; basic carbonate; bismuth acid oxychloride; natural guanine; flaky glass powder; metal-deposited flaky glass There is no particular limitation as long as it has a brilliant property such as powder.
Among the bright pigments, metal powder is preferable, and aluminum is most preferable, particularly from the viewpoint of specular reflection intensity. Aluminum has a high effect on filming due to the above-mentioned filler effect in addition to high brilliance.

The shape of the bright pigment is preferably flat (scaly).
The average length of the bright pigment in the major axis direction is preferably 1 μm or more and 30 μm or less, more preferably 3 μm or more and 20 μm or less, and further preferably 5 μm or more and 15 μm or less.
The ratio (aspect ratio) of the average length in the major axis direction when the average length in the thickness direction of the bright pigment is 1, is preferably 5 or more and 200 or less, and more preferably 10 or more and 100 or less. More preferably, it is 30 or more and 70 or less.

Each average length and aspect ratio of the glitter pigment is measured by the following method. Using a scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Co., Ltd.), a photograph of the pigment particles is taken at a measurable magnification (300 to 100,000 times), and the obtained image of the pigment particles is two-dimensional. In this state, the length in the major axis direction and the length in the thickness direction of each particle are measured, and the average length and aspect ratio in the major axis direction of the brilliant pigment are calculated.

The content of the brilliant pigment is, for example, preferably 1 part by mass or more and 50 parts by mass or less, and more preferably 15 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the toner particles.

-Characteristics of brilliant toner particles-
-Glittering In the brilliant toner particles, "brilliant" means having a brilliance such as metallic luster when an image formed by a toner containing the brilliant toner particles (hereinafter, also referred to as "brilliant toner") is visually recognized. Represents that.
Specifically, the brilliant toner reflects at a light receiving angle of + 30 °, which is measured when a solid image is formed and the image is irradiated with incident light at an incident angle of −45 ° by a variable angle photometer. The ratio (X / Y) of the rate X to the reflectance Y at the light receiving angle −30 ° is preferably 2 or more and 100 or less.

A ratio (X / Y) of 2 or more means that the incident light is reflected more on the opposite side (angle + side) than on the incident side (angle-side). That is, it means that the diffused reflection of the incident light is suppressed. When diffuse reflection occurs in which the incident light is reflected in various directions, the color looks dull when the reflected light is visually confirmed. Therefore, when the ratio (X / Y) is less than 2, the gloss may not be confirmed even when the reflected light is visually recognized, and the brilliance may be inferior.
On the other hand, when the ratio (X / Y) exceeds 100, the viewing angle at which the reflected light can be visually recognized becomes too narrow, and the specularly reflected light component is large, so that the reflected light may appear blackish depending on the viewing angle.

The ratio (X / Y) is more preferably 4 or more and 50 or less, still more preferably 6 or more and 20 or less, from the viewpoint of the brilliance of the image and the manufacturability of the brilliant toner particles. It is particularly preferable that the amount is 15 or more.

-Measurement of ratio (X / Y) with a variable angle photometer Here, the incident angle and the light receiving angle will be described first. When measuring with a variable-angle photometer, the incident angle is set to -45 ° because the measurement sensitivity is high for images in a wide range of glossiness.
Further, the light receiving angles are set to −30 ° and + 30 ° because the measurement sensitivity is the highest for evaluating an image with a brilliant feeling and an image without a shining feeling.

Next, a method of measuring the ratio (X / Y) will be described.
A spectroscopic variable angle color difference meter GC5000L manufactured by Nippon Denshoku Kogyo Co., Ltd. is used as a variable angle photometer for the image to be measured (brightness image), and incident light with an incident angle of −45 ° is incident on the image. Then, the reflectance X at the light receiving angle + 30 ° and the reflectance Y at the light receiving angle −30 ° are measured. The reflectance X and the reflectance Y were measured at intervals of 20 nm for light having a wavelength in the range of 400 nm to 700 nm, and were taken as the average value of the reflectance at each wavelength. The ratio (X / Y) is calculated from these measurement results.

The glittering toner particles preferably satisfy the following requirements (1) and (2) from the viewpoint of satisfying the above-mentioned ratio (X / Y).
(1) The average circle equivalent diameter D is longer than the average maximum thickness C of the brilliant toner particles.
(2) When observing a cross section of the brilliant toner particles in the thickness direction, the angle between the long axis direction of the brilliant toner particles and the long axis direction of the brilliant pigment is -30 ° to + 30 °. The proportion of brilliant pigments in the range is 60% or more of the total brilliant pigments observed.

When the brilliant toner particles have a flat shape having a diameter equivalent to a circle longer than the thickness, the flat surface side of the brilliant toner particles becomes the surface of the recording medium due to the pressure at the time of fixing in the fixing step of image formation. It is thought that they are lined up so as to face each other.
Therefore, among the flat (scaly) bright pigments contained in the bright toner particles, the "long-axis direction in the cross section of the toner and the long-axis direction of the bright pigment" shown in (2) above It is considered that the bright pigments satisfying the requirement that the angle is in the range of −30 ° to + 30 ° are arranged so that the surface side having the maximum area faces the surface of the recording medium. When the image formed in this way is irradiated with light, it is considered that the above-mentioned ratio (X / Y) range is achieved because the ratio of the bright pigment that diffusely reflects the incident light is suppressed. Be done.

-Average maximum thickness C and average circle equivalent diameter D of brilliant toner particles
It is preferable that the brilliant toner particles are flat and have an average circle-equivalent diameter D longer than the average maximum thickness C. The ratio (C / D) of the average maximum thickness C to the average circle equivalent diameter D is more preferably in the range of 0.001 or more and 0.500 or less, and further in the range of 0.010 or more and 0.200 or less. The range of 0.050 or more and 0.100 or less is particularly preferable.
When the ratio (C / D) is 0.001 or more, the strength of the toner is ensured, fracture due to stress during image formation is suppressed, charge is reduced due to exposure of the pigment, and fog is generated as a result. Is suppressed. On the other hand, when it is 0.500 or less, excellent brilliance can be obtained.

The average maximum thickness C and the average circle equivalent diameter D of the brilliant toner particles are measured by the following methods.
Glittering toner particles are placed on a smooth surface and vibrated to disperse them evenly. The maximum thickness C of the brilliant toner particles and the equivalent circle diameter D of the surface seen from above were magnified 1000 times by the color laser microscope "VK-9700" (manufactured by KEYENCE) for 1000 brilliant toner particles. Is measured, and it is calculated by calculating the arithmetic mean value of them.

Angle between the major axis direction in the cross section of the brilliant toner particles and the major axis direction of the brilliant pigment When observing the cross section in the thickness direction of the brilliant toner particles, the major axis direction in the cross section of the brilliant toner particles. It is preferable that the ratio (number basis) of the brilliant pigment in which the angle between the brilliant pigment and the major axis direction is in the range of -30 ° to + 30 ° is 60% or more of the observed total brilliant pigments. .. Furthermore, the above ratio is more preferably 70% or more and 95% or less, and particularly preferably 80% or more and 90% or less.
When the above ratio is 60% or more, excellent brilliance can be obtained.

Here, a method of observing the cross section of the brilliant toner particles will be described.
After embedding the glittering toner particles with a bisphenol A type liquid epoxy resin and a curing agent, a sample for cutting is prepared. Next, a cutting machine using a diamond knife, for example, an ultramicrotome device (UltracutUCT, manufactured by Leica) is used to cut the cutting sample at −100 ° C. to prepare an observation sample. The observation sample is observed with an ultra-high resolution field emission scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation) at a magnification in which about 1 to 10 bright toner particles can be seen in one field of view.
Specifically, the cross section of the brilliant toner particles (the cross section along the thickness direction of the brilliant toner particles) is observed, and for the observed 100 brilliant toner particles, the long axis direction in the cross section of the brilliant toner particles. The number of bright pigments whose angle between the and the long axis direction of the bright pigment is in the range of -30 ° to + 30 ° can be determined by image analysis software such as image analysis software (Win ROOF) manufactured by Mitani Shoji Co., Ltd. or observation. Count using the image output sample and the divider to calculate the ratio.

The "long-axis direction in the cross section of the brilliant toner particles" represents a direction orthogonal to the thickness direction of the brilliant toner particles having an average circle equivalent diameter D longer than the above-mentioned average maximum thickness C. The "long-axis direction of the brilliant pigment" represents the length direction of the brilliant pigment.

-Volume average particle size of the brilliant toner particles The volume average particle size of the brilliant toner particles is preferably 1 μm or more and 30 μm or less, and more preferably 3 μm or more and 20 μm or less.

(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, fluoropolymers). Particles) and the like.

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

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

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

First, a method for producing toner particles by the aggregation and coalescence method will be described.
A step of preparing a resin particle dispersion liquid in which resin particles to be a binder resin are dispersed (resin particle dispersion liquid preparation step) and a step of preparing the resin particle dispersion liquid (after mixing other particle dispersion liquids as necessary). (In the dispersion), resin particles (other particles if necessary) are agglomerated to form agglomerated particles (aggregated particle forming step), and the agglomerated particle dispersion in which the agglomerated particles are dispersed is heated. Toner particles are manufactured through a step of fusing and coalescing agglomerated particles to form toner particles (fusing and coalescing step).
Here, as the resin particle dispersion liquid, an amorphous resin particle dispersion liquid in which amorphous resin particles are dispersed and a crystalline resin particle dispersion liquid in which crystalline resin particles are dispersed are applied. As the resin particle dispersion liquid, an amorphous resin particle dispersion liquid in which resin particles containing an amorphous resin and a crystalline resin are dispersed may be applied.

The details of each step will be described below.
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 colorants and mold release agents may be used.

-Resin particle dispersion liquid preparation process-
First, together with the resin particle dispersion liquid in which the resin particles to be the binder resin are dispersed, for example, a colorant particle dispersion liquid in which the colorant particles are dispersed and a release agent particle dispersion liquid in which the release agent particles are dispersed are prepared. do.

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

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

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Examples thereof include nonionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols. 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.
The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include general dispersion methods such as a rotary shear homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of the resin particles, the resin particles may be dispersed in the resin particle dispersion liquid by using, for example, 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, and a base is added to the organic continuous phase (O phase) to neutralize the resin, and then the aqueous medium is used. A method in which the (W phase) is charged to convert the resin from W / O to O / W (so-called phase inversion) to discontinue the phase, and the resin is dispersed in an aqueous medium in the form of particles. Is.

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

The content of the resin particles contained in the resin particle dispersion is, for example, 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.

In addition, in the same manner as the resin particle dispersion liquid, for example, a colorant particle dispersion liquid and a release agent particle dispersion liquid are also prepared. That is, regarding the volume average particle size, dispersion medium, dispersion method, and particle content of the particles in the resin particle dispersion, the colorant particles dispersed in the colorant particle dispersion and the release agent particle dispersion are used. The same applies to the disperse of the release agent particles.

-Agglomerated particle formation process-
Next, the colorant particle dispersion liquid and the release agent particle dispersion liquid are mixed together with the resin particle dispersion liquid.
Then, in the mixed dispersion, the resin particles, the colorant particles, and the release agent particles are heteroaggregated to form the resin particles, the colorant particles, and the release agent particles having a diameter close to the diameter of the target toner particles. Form agglomerated particles containing.

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

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

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

-Fusion / unification process-
Next, the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed is heated to, for example, a temperature equal to or higher than the glass transition temperature of the resin particles (for example, a temperature 10 to 30 ° C. higher than the glass transition temperature of the resin particles) to obtain the agglomerated particles. Are fused and united to form toner particles.

Toner particles are obtained through the above steps.
After obtaining the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed, the agglomerated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles are dispersed are further mixed, and the resin particles are further added to the surface of the agglomerated particles. The step of aggregating so as to adhere to form the second agglomerated particles and the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed are heated to fuse and unite the second agglomerated particles. , Toner particles may be produced through a step of forming toner particles having a core / shell structure.
However, the resin particles adhering to the surface of the agglomerated particles are preferably amorphous resin particles.

Here, after the fusion / coalescence step is completed, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain toner particles in a dried state.
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.

Next, a case where toner particles containing a urea-modified polyester resin (urea-modified amorphous polyester resin) is produced will be described.
Toner particles containing a urea-modified polyester resin may be obtained by the following dissolution / suspension method. A method for obtaining toner particles containing a urea-modified polyester resin (amorphous polyester resin modified with urea) and an unmodified crystalline polyester resin as a binder resin will be described. The toner particles are unmodified as a binder resin. Amorphous polyester resin of the above may be contained. Further, a method for obtaining toner particles containing a colorant and releasability will be described. The colorant and releasability are components contained in the toner particles, if necessary.

[Oil phase liquid preparation process]
An organic solvent for a toner particle material containing an unmodified crystalline polyester resin (hereinafter, also simply referred to as “crystalline polyester resin”), an amorphous polyester prepolymer having an isocyanate group, an amine compound, a colorant, and a mold release agent. The oil phase liquid dissolved or dispersed in the mixture is prepared (oil phase liquid preparation step). This oil phase liquid preparation step is a step of dissolving or dispersing the toner particle material in an organic solvent to obtain a mixed liquid of the toner material.

The oil phase liquid is prepared by 1) a method of preparing by dissolving or dispersing the toner material in an organic solvent all at once, and 2) kneading the toner material in advance and then dissolving or dispersing this kneaded product in an organic solvent. 3) A crystalline polyester resin, an amorphous polyester prepolymer having an isocyanate group, and an amine compound are dissolved in an organic solvent, and then a colorant and a mold release agent are dispersed in the organic solvent to prepare the mixture. 4) After dispersing the colorant and the release agent in an organic solvent, a crystalline polyester resin, an amorphous polyester prepolymer having an isocyanate group, and an amine compound are dissolved in the organic solvent to prepare the mixture. Method 5) Toner particle materials (crystalline polyester resin, colorant, and mold release agent) other than the amorphous polyester prepolymer having an isocyanate group and the amine compound are dissolved or dispersed in an organic solvent, and then the organic solvent is used. A method for preparing by dissolving an amorphous polyester prepolymer having an isocyanate group and an amine compound in 6) Toner particle material other than the amorphous polyester prepolymer having an isocyanate group or an amine compound (crystalline polyester resin, coloring). An agent and a mold release agent) are dissolved or dispersed in an organic solvent, and then an amorphous polyester prepolymer having an isocyanate group or an amine compound is dissolved in the organic solvent to prepare the agent. The method for preparing the oil phase liquid is not limited to these.

Examples of the organic solvent of the oil phase liquid include ester solvents such as methyl acetate and ethyl acetate; ketone solvents such as methyl ethyl ketone and methyl isopropyl ketone; aliphatic hydrocarbon solvents such as hexane and cyclohexane; dichloromethane, chloroform, trichloroethylene and the like. Examples thereof include halogenated hydrocarbon solvents. These organic solvents preferably dissolve the binder resin, dissolve in water at a rate of 0% by mass or more and 30% by mass or less, and have a boiling point of 100 ° C. or less. Among these organic solvents, ethyl acetate is preferable.

-Suspension preparation process-
Next, the obtained oil phase liquid is dispersed in the aqueous phase liquid to prepare a suspension (suspension preparation step).
Then, along with the preparation of the suspension, the amorphous polyester prepolymer having an isocyanate group and the amine compound are reacted. Then, a urea-modified polyester resin is produced by this reaction. This reaction involves at least one of a molecular chain cross-linking reaction and an extension reaction. The reaction between the amorphous polyester prepolymer having an isocyanate group and the amine compound may be carried out together with the organic solvent removing step described later.
Here, the reaction conditions are selected based on the reactivity between the isocyanate group structure of the amorphous polyester prepolymer and the amine compound. As an example, the reaction time is preferably 10 minutes or more and 40 hours or less, and preferably 2 hours or more and 24 hours or less. The reaction temperature is preferably 0 ° C. or higher and 150 ° C. or lower, and preferably 40 ° C. or higher and 98 ° C. or lower. If necessary, a known catalyst (dibutyltin laurate, dioctyltin laurate, etc.) may be used to produce the urea-modified polyester resin. That is, the catalyst may be added to the oil phase liquid or the suspension.

Examples of the aqueous phase liquid include an aqueous phase liquid in which a particle dispersant such as an organic particle dispersant and an inorganic particle dispersant is dispersed in an aqueous solvent. Further, as the aqueous phase liquid, an aqueous phase liquid in which a particle dispersant is dispersed in an aqueous solvent and a polymer dispersant is dissolved in an aqueous solvent can also be mentioned. A well-known additive such as a surfactant may be added to the aqueous phase liquid.

Examples of the aqueous solvent include water (for example, usually ion-exchanged water, distilled water, pure water). The aqueous solvent is a solvent containing water and an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellsolves (methylcellsolve, etc.), lower ketones (acetone, methylethylketone, etc.). There may be.

Examples of the organic particle dispersant include hydrophilic organic particle dispersants. Examples of the organic particle dispersant include particles such as poly (meth) acrylic acid alkyl ester resin (for example, polymethyl methacrylate resin), polystyrene resin, and poly (styrene-acrylonitrile) resin. Examples of the organic particle dispersant include particles of styrene acrylic resin.

Examples of the inorganic particle dispersant include hydrophilic inorganic particle dispersants. Specific examples of the inorganic particle dispersant include particles such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, clay, diatomaceous earth, and bentonite, and calcium carbonate particles are preferable. As the inorganic particle dispersant, one type may be used alone, or two or more types may be used in combination.

The surface of the particle dispersant may be surface-treated with a polymer having a carboxyl group.
As the polymer having a carboxyl group, the carboxyl group of α, β-monoethylene unsaturated carboxylic acid or α, β-monoethylene unsaturated carboxylic acid is made of alkali metal, alkaline earth metal, ammonium, amine or the like. Examples include a copolymer of at least one selected from neutralized salts (alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc.) and α, β-monoethylene unsaturated carboxylic acid esters. Be done. As the polymer having a carboxyl group, the carboxyl group of the copolymer of α, β-monoethylene unsaturated carboxylic acid and α, β-monoethylene unsaturated carboxylic acid ester is an alkali metal or an alkaline earth metal. , Alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc., which are neutralized with ammonium, amines and the like. As the polymer having a carboxyl group, one type may be used alone, or two or more types may be used in combination.

Typical examples of α, β-monoethylene unsaturated carboxylic acid are α, β-unsaturated monocarboxylic acid (acrylic acid, methacrylic acid, crotonic acid, etc.) and α, β-unsaturated dicarboxylic acid (maleic acid). Acid, fumaric acid, itaconic acid, etc.) and the like. Typical examples of α, β-monoethyl unsaturated carboxylic acid esters include alkyl esters of (meth) acrylic acid, (meth) acrylates having an alkoxy group, and (meth) acrylates having a cyclohexyl group. Examples thereof include (meth) acrylate having a hydroxy group and polyalkylene glycol mono (meth) acrylate.

Examples of the polymer dispersant include hydrophilic polymer dispersants. Specific examples of the polymer dispersant include water-soluble polymer dispersants (for example, carboxymethyl cellulose, carboxyethyl cellulose, etc.) having a carboxyl group and no parent oil group (hydroxypropoxy group, methoxy group, etc.). Sexual cellulose ether).

-Solvent removal process-
Next, the organic solvent is removed from the obtained suspension to obtain a toner particle dispersion (solvent removal step). This solvent removing step is a step of removing the organic solvent contained in the droplets of the aqueous phase liquid dispersed in the suspension to generate toner particles. The removal of the organic solvent from the suspension may be carried out immediately after the suspension preparation step, or may be carried out one minute or more after the completion of the suspension preparation step.
In the solvent removal step, it is preferable to remove the organic solvent from the suspension by cooling or heating the obtained suspension to, for example, 0 ° C. or higher and 100 ° C. or lower.

Specific methods for removing the organic solvent include the following methods.
(1) A method of forcibly updating the gas phase on the suspension surface by blowing an air flow on the suspension. In this case, gas may be blown into the suspension.
(2) A method of reducing the pressure. In this case, the gas phase on the suspension surface may be forcibly renewed by filling with gas, or gas may be further blown into the suspension.

Toner particles are obtained through the above steps.
Here, after the solvent removal step is completed, the toner particles formed in the toner particle dispersion liquid are subjected to a known cleaning step, solid-liquid separation step, and drying step to obtain toner particles in a dried state.
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.

Next, the annealing step will be described.
In the production of toner particles, for example, it is preferable to perform an annealing treatment (heat treatment) on the toner particles obtained through the above steps.

Specifically, for example, the obtained toner particles are heated to a temperature of 40 ° C. or higher and 70 ° C. or lower, and held at that temperature within a range of 0.5 hour or longer and 15 hours or lower. By this treatment, the phase separation between the crystalline resin and the amorphous resin can be sufficiently advanced in the obtained toner particles. Therefore, the toner easily satisfies the above formula (1): 0.9 ≦ a / b ≦ 1.0.

The timing of the annealing step is a process in which the "solvent state of the amorphous resin and the crystalline resin" in the toner particles is excessively changed after the annealing step (the toner is the above formula (1): formula (1): 0. .9 ≤ a / b ≤ 1.0) is not limited to the above, for example, in a dispersion liquid in which toner particles are formed or in a slurry state in which the amount of solvent in the dispersion liquid is reduced. It may be carried out.

In addition, for example, the following processing may be performed. First, the obtained toner particles are redispersed in a dispersion medium (for example, water or the like) to form a dispersion liquid. In the toner particle dispersion, the temperature is equal to or higher than the glass transition temperature of the amorphous polyester resin (specifically, the glass transition temperature of the amorphous polyester resin is + 5 ° C. or higher, and more preferably + 10 ° C. of the amorphous polyester resin. After heating to the above temperature, the temperature is maintained at that temperature for 0.5 hours or more and 10 hours or less (preferably 2 hours or more and 8 hours or less). Then, the toner particles are rapidly cooled (for example, preferably 3 ° C./min or more and 30 ° C./min or less, preferably 5 ° C./min or more and 20 ° C./min or less). By this treatment, toner particles in which the compatibility between the amorphous resin and the crystalline resin has progressed excessively are once obtained. After that, when annealing treatment is performed under the above conditions, phase separation between the crystalline resin and the amorphous resin proceeds in the obtained toner particles, and the phase-separated crystalline resin domain is highly dispersible (toner particles). That is, toner particles having an enhanced filler effect of the crystalline resin) can be easily obtained, and the occurrence of toner filming can be easily suppressed.

When the toner particles are produced by the agglomeration and coalescence method, they are held at the agglomeration and coalescence temperature for 0.5 hours or more and 20 hours or less (preferably 5 hours or more and 15 hours or less) in the agglomeration / coalescence step. After that, by quenching under the above conditions, it is possible to obtain toner particles in which the compatibility between the amorphous resin and the crystalline resin has progressed excessively. After that, if annealing treatment is performed under the above conditions, phase separation between the crystalline resin and the amorphous resin proceeds in the obtained toner particles, and the phase-separated crystalline resin domain is highly dispersible. (That is, toner particles having an enhanced filler effect of the crystalline resin) can be easily obtained, and the occurrence of toner filming can be easily suppressed.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive to the obtained dry toner particles 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.

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

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

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

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

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

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

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

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

The 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 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 multiple 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 is (-) polarity, which is the same polarity as the polarity (-) of the toner, and the electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied on the intermediate transfer belt 20. The toner image of is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by the resistance detecting means (not shown) for detecting the resistance of the secondary transfer unit, and is voltage controlled.

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

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

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

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

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

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

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

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present embodiment is a toner cartridge that houses the toner according to the present embodiment and is attached to and detached from the image forming apparatus. The toner cartridge contains 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 "%" are based on mass unless otherwise specified.

<Preparation of toner particles (A1)>
(Preparation of Amorphous Polyester Resin Particle Dispersion Liquid (A1))
・ Telephthalic acid: 30 mol parts ・ Fumaric acid: 70 mol parts ・ Bisphenol A ethylene oxide adduct: 10 mol parts ・ Bisphenol A propylene oxide adduct: 90 mol parts Stirrer, nitrogen introduction tube, temperature sensor, and rectification tower The above-mentioned material was placed in a flask having a content of 5 liters, the temperature was raised to 220 ° C. over 1 hour, and 1 part of titanium tetraethoxydo was added to 100 parts of the above-mentioned material. The temperature was raised to 230 ° C. over 0.5 hours while distilling off the generated water, and the dehydration condensation reaction was continued at that temperature for 1 hour, and then the reaction product was cooled. In this way, an amorphous polyester resin (A1) having a weight average molecular weight of 20,000, an acid value of 13 mgKOH / g, and a glass transition temperature of 60 ° C. was synthesized.

Next, 40 parts of ethyl acetate and 25 parts of 2-butanol were put into a container equipped with a temperature control means and a nitrogen substitution means to prepare a mixed solvent, and then 100 parts of an amorphous polyester resin (A1) was gradually put into the container. To dissolve the mixture, a 10 mass% aqueous ammonia solution (equivalent to 3 times the molar ratio of the acid value of the resin) was added thereto, and the mixture was stirred for 30 minutes.

Next, the inside of the container was replaced with dry nitrogen, the temperature was maintained at 40 ° C., and 400 parts of ion-exchanged water was added dropwise at a rate of 2 parts / minute while stirring the mixture to emulsify. After completion of the dropping, the emulsion was returned to room temperature (20 ° C to 25 ° C) and bubbling with dry nitrogen for 48 hours with stirring to reduce ethyl acetate and 2-butanol to 1,000 ppm or less, and the volume average particles were obtained. A resin particle dispersion liquid in which resin particles having a diameter of 200 nm were dispersed was obtained. Ion-exchanged water was added to the resin particle dispersion liquid to adjust the solid content to 20% by mass to obtain an amorphous polyester resin particle dispersion liquid (A1).

(Preparation of crystalline polyester resin particle dispersion liquid (A1))
・ 1,10-Dodecane diic acid: 50 mol parts ・ 1,9-Nonanediol: 50 mol parts Put the above monomer components in a reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas introduction tube, and put the above monomer components in the reaction vessel. Was replaced with dry nitrogen gas, and then 0.25 part of titanium tetrabutoxide (reagent) was added to 100 parts of the monomer component. After a stirring reaction at 170 ° C. for 3 hours under a nitrogen gas stream, the temperature was further raised to 210 ° C. over 1 hour, the inside of the reaction vessel was reduced to 3 kPa, and the reaction was stirred under reduced pressure for 13 hours to crystallize. A sex polyester resin (A1) was obtained.
The obtained crystalline polyester resin (A1) has a melting temperature of 73.6 ° C. by DSC, a mass average molecular weight Mw of 25,000 by GPC, a number average molecular weight of Mn of 10,500, and an acid value of AV of 10.1 mgKOH /. It was g.

Next, in a 3-liter reaction tank with a jacket (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dropping device, and an anchor wing, 300 parts of crystalline polyester resin (1) and methyl ethyl ketone were added. 160 parts of (solvent) and 100 parts of isopropyl alcohol (solvent) were added, and the resin was dissolved while stirring and mixing at 100 rpm while maintaining the temperature at 70 ° C. in a water circulation type constant temperature bath (dissolution solution preparation step).
After that, the stirring rotation speed was set to 150 rpm, the water circulation type constant temperature bath was set to 66 ° C., 17 parts of 10% ammonia water (reagent) was added over 10 minutes, and then 7 parts of ion-exchanged water kept at 66 ° C./ A total of 900 parts were added dropwise at a rate of 1 minute to invert the phase to obtain an emulsion.

Immediately, 800 parts of the obtained emulsion and 700 parts of ion-exchanged water were placed in a 2 liter eggplant flask and set in an evaporator (Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. While rotating the eggplant flask, it was heated in a hot water bath at 60 ° C., and the pressure was reduced to 7 kPa while paying attention to sudden boiling to remove the solvent. When the amount of solvent recovered reached 1,100 parts, the pressure was returned to normal pressure, and the eggplant flask was water-cooled to obtain a dispersion liquid. The obtained dispersion had no solvent odor. The volume average particle diameter D50v of the resin particles in this dispersion was 130 nm. Then, ion-exchanged water was added to prepare the solid content concentration to 20%, and this was used as a crystalline polyester resin particle dispersion liquid (A1).

(Preparation of colorant particle dispersion liquid (A1))
-Cyan pigment: C.I. I. PigmentBlue 15: 3 (Dainichiseika Co., Ltd., ECB301): 70 parts-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts-Ion-exchanged water: 200 parts Mix the above materials. Dispersion was performed for 10 minutes using a homogenizer (Ultra Tarax T50 manufactured by IKA). Ion-exchanged water was added so that the solid content in the dispersion was 20% by mass to obtain a colorant particle dispersion (A1) in which colorant particles having a volume average particle diameter of 140 nm were dispersed.

(Preparation of release agent particle dispersion liquid (A1))
・ Paraffin wax (HNP-9 manufactured by Nippon Seiwa Co., Ltd.) 100 parts ・ Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 part ・ Ion exchange water 350 parts Mix the above materials After heating to 100 ° C. and dispersing using a homogenizer (Ultratarax T50 manufactured by IKA), dispersion treatment is performed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin) to disperse the release agent particles having a volume average particle size of 200 nm. A release agent particle dispersion (A1) (solid content: 20% by mass) was obtained.

(Preparation of toner particles)
・ Amorphous polyester resin particle dispersion (A1): 425 parts ・ Crystalline polyester resin particle dispersion (A1): 32 parts ・ Colorant dispersion (A1): 20 parts ・ Release agent dispersion (A1): 50 parts ・ Anionic surfactant (TaycaPower manufactured by Teika Co., Ltd.): 30 parts After putting the above-prepared material in a round stainless steel flask and adding 0.1N nitrate to adjust the pH to 3.5. , 30 parts of a nitrate aqueous solution having a polyamorphous aluminum chloride concentration of 10% by mass was added. Subsequently, after dispersing at 30 ° C. using a homogenizer (Ultra Tarax T50 manufactured by IKA), the mixture was heated to 40 ° C. in a heating oil bath and held for 30 minutes. Then, 100 parts of the amorphous polyester resin particle dispersion (A1) was gently added and held for 1 hour, and 0.1 N sodium hydroxide aqueous solution was added to adjust the pH to 8.5, and then stirring was continued. While heating to 100 ° C., the mixture was kept for 10 hours. Then, after cooling to 20 ° C. at a rate of 20 ° C./min, the mixture was reheated (annealed) to 55 ° C. and held for 6 hours. Then, it was cooled to 20 ° C. at a rate of 20 ° C./min. Then, it was filtered, thoroughly washed with ion-exchanged water, and dried to obtain toner particles having a volume average particle size of 4.0 μm. Then, the obtained toner particles were designated as toner particles (A1).

<Preparation of toner particles (A2)>
Toner particles (A2) were obtained in the same manner as the toner particles (A1) except that the conditions for the reheating treatment (annealing treatment) at 55 ° C. were left for 0.5 hours.

<Preparation of toner particles (A3)>
Toner particles (A3) were obtained in the same manner as the toner particles (A1) except that the conditions for the reheating treatment (annealing treatment) at 55 ° C. were left for 10 hours.

<Preparation of toner particles (A4)>
The toner particles (A4) are the same as the toner particles (A1) except that the number of copies of the prepared amorphous polyester resin particle dispersion (A1) and the crystalline polyester resin particle dispersion (A1) is changed according to Table 1. Got

<Preparation of toner particles (A5)>
According to Table 1, the number of copies of the prepared amorphous polyester resin particle dispersion (A1) and the crystalline polyester resin particle dispersion (A1) was changed, and the conditions for reheating treatment (annealing treatment) at 55 ° C. were set for 7 hours. Toner particles (A5) were obtained in the same manner as the toner particles (A1) except that they were left to stand.

<Preparation of toner particles (P1)>
(Synthesis of crystalline polyester resin (P1))
The above material (fumaric acid) in a flask with a content of 5 liters equipped with a stirrer, a nitrogen introduction tube, a temperature sensor, and a rectification column, together with 80.9 parts of fumaric acid and 46.3 parts of 1,10-decanediol. And 1,10-decanediol), 1 part of titanium tetraethoxydo was added to 100 parts. The reaction was carried out at 150 ° C. for 4 hours while removing the water to be produced, then the temperature was raised to 180 ° C. over 6 hours under a nitrogen stream, and the reaction was carried out at 180 ° C. for 6 hours. Then, the reaction was carried out under reduced pressure for 1 hour and cooled to obtain an unmodified crystalline polyester resin (P1).

(Synthesis of amorphous polyester resin (P1))
Addition of 30 parts of isophthalic acid, 70 parts of fumaric acid, 5 mol of bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct to a 5 liter flask equipped with a stirrer, nitrogen introduction tube, temperature sensor, and rectification tower. 95 parts of the product was charged, the temperature was raised to 220 ° C. in 1 hour, and titanium tetra was added to 100 parts of the above materials (isophthalic acid, fumaric acid, bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct). One part of ethoxydo was added. The temperature was raised to 230 ° C. over 0.5 hours while distilling off the generated water, and the dehydration condensation reaction was continued at that temperature for 1 hour, and then the reaction product was cooled. Then, isophorone diisocyanate is added to 1 part of this resin so as to form 2 parts, 5 parts of ethyl acetate is added to dissolve the resin, and the reaction is carried out at 200 ° C. for 3 hours and then cooled. A crystalline polyester resin (P1) was obtained.

(Preparation of release agent particle dispersion)
Mix 100 parts of paraffin wax (HNP-9 manufactured by Nippon Seiwa Co., Ltd.), 1 part of anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and 350 parts of ion-exchanged water to 100 ° C. After heating and dispersing using a homogenizer (Ultratarax T50 manufactured by IKA), dispersion treatment was performed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin), and mold release agent particles having a volume average particle size of 200 nm were dispersed. An agent particle dispersion (solid content 20% by mass) was obtained.

(Making a masterbatch)
150 parts of amorphous polyester resin (P1), 80 parts of cyan pigment (pigment15: 3, manufactured by Dainichiseika), and 20 parts of ion-exchanged water were mixed using a Henschel mixer. A masterbatch was prepared by pulverizing the obtained mixture.

(Preparation of oil phase (A) / aqueous phase)
Add 107 parts of amorphous polyester resin (P1), 75 parts of release agent dispersion, 18 parts of masterbatch, and 73 parts of ethyl acetate, and stir with a homogenizer (Ultra Tarax T50 manufactured by IKA) to dissolve and disperse. The oil phase (A) was obtained. Further, 990 parts of ion-exchanged water, 100 parts of anionic surfactant, and 100 parts of ethyl acetate were mixed and stirred in another flask to obtain an aqueous phase.

(Emulsification dispersion)
To 450 parts of the oil phase (A), 100 parts of a solution (solid content concentration of 10%) in which crystalline polyester resin (P1) was dissolved with ethyl acetate and 3 parts of isophorone diamine were added, and a homogenizer (Ultrata manufactured by IKA) was added. The mixture was stirred with Lux T50), dissolved and dispersed at 50 ° C. to obtain an oil phase (B). Next, 400 parts of the aqueous phase was placed in another container, and the mixture was stirred with a homogenizer (Ultra Tarax T50 manufactured by IKA) at 50 ° C. To this aqueous phase, 50 parts of the oil phase (B) was added, and the mixture was stirred at 50 ° C. using a homogenizer (Ultratarax T50 manufactured by IKA) for 5 minutes to obtain an emulsified slurry. A toner slurry was obtained by removing the solvent from this emulsified slurry at 50 ° C. for 15 hours. The toner slurry was filtered under reduced pressure and then washed to obtain toner particles.

Then, after washing, the dispersion liquid added to 50 parts of toner particles and 500 parts of ion-exchanged water was stirred in a flask having an internal volume of 5 liters equipped with a stirrer, a nitrogen introduction tube, a temperature sensor, and a rectification tower. , The temperature was raised to 85 ° C. After the temperature was raised, the dispersion was stirred for 24 hours while maintaining the temperature rise. As a result, the toner particles were heated at 85 ° C. for 24 hours. Then, liquid nitrogen was added to the dispersion, and the toner particles were cooled (quenched) at 20 ° C./min to room temperature (25 ° C.). Then, it was reheated to 55 ° C. and held for 7 hours. Then, it was cooled to 20 ° C. at a rate of 20 ° C./min.

(Drying, sieving)
The obtained toner particles were dried and sieved to prepare toner particles having a volume average particle size of 7 μm.

Through the above steps, toner particles (P1) were obtained.

<Preparation of brilliant toner particles (B1)>
(Preparation of bright pigment dispersion)
-Aluminum pigment (manufactured by Showa Aluminum Powder Co., Ltd., 2173EA 6 μm): 100 parts-Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen R): 1.5 parts-Ion exchange water: 400 parts Aluminum pigment paste The solvent was removed from the mixture, and the pigment was mechanically pulverized to 5.2 μm and classified using a star mill (LMZ, manufactured by Ashizawa Finetech Co., Ltd.). After that, it was mixed with the above-mentioned surfactant and ion-exchanged water and dispersed for about 1 hour using an emulsification disperser Cavitron (manufactured by Pacific Kiko Co., Ltd., CR1010) to disperse bright pigment particles (aluminum pigment). A bright pigment dispersion was prepared (solid content concentration: 20% by mass). The pigment dispersion diameter was 5.2 μm.

(Preparation of brilliant toner particles)
-Glittering pigment dispersion: 150 parts-Amorphous polyester resin particle dispersion (A1): 380 parts-Crystalline polyester resin particle dispersion (A1): 75 parts-Release agent dispersion (A1): 75 parts The above components were placed in a 2 L cylindrical stainless steel container, and dispersed and mixed for 10 minutes while applying a shearing force at 4000 rpm with a homogenizer (Ultratalax T50 manufactured by IKA). Next, 1.75 parts of a 10% aqueous nitric acid solution of polyaluminum chloride was gradually added dropwise as a coagulant, and the homogenizer was dispersed at 5000 rpm for 15 minutes to prepare a raw material dispersion.
After that, the dispersion liquid was transferred to a polymerization kettle equipped with a stirring device using a stirring blade of four paddles and a thermometer, the stirring speed was set to 1000 rpm, and heating was started with a mantle heater, and the aggregated particles were heated at 54 ° C. Promoted growth. At this time, the pH of the dispersion was controlled in the range of 2.2 to 3.5 by using 0.3 mol / L nitric acid or 1 mol / L sodium hydroxide aqueous solution. It was kept in the above pH range for about 2 hours to form aggregated particles.

Next, 70 parts of the amorphous polyester resin dispersion liquid (A1) was additionally added to attach the amorphous polyester resin particles to the surface of the aggregated particles. The temperature was further raised to 56 ° C., and the aggregated particles were prepared while checking the size and morphology of the particles with an optical microscope and Multisizer II. Then, 3.25 parts of a chelating agent (HIDS, manufactured by Nippon Shokubai Co., Ltd.) was added, and then the pH was adjusted to 7.8 with a 5% aqueous sodium hydroxide solution and held for 15 minutes. Then, the pH was raised to 8.0 in order to fuse the agglomerated particles, and then the temperature was raised to 67.5 ° C. After confirming that the agglomerated particles were fused with an optical microscope, the pH was lowered to 6.0 while maintaining the temperature at 67.5 ° C., heating was stopped after 1 hour, and the mixture was cooled at a temperature lowering rate of 1.0 ° C./min. Then, it was reheated (annealed) to 55 ° C. and held for 6 hours, and then cooled at a temperature lowering rate of 1.0 ° C./min. Then, it was sieved with a 40 μm mesh, washed with water repeatedly, and then dried with a vacuum dryer to obtain toner particles. The volume average particle diameter of the obtained toner particles was 11.5 μm. Then, the obtained toner particles were designated as brilliant toner particles (B1).

<Preparation of toner particles (C1)>
Toner particles (C1) were obtained in the same manner as the toner particles (A1) except that the toner particles (A1) were not reheated to 55 ° C.

<Preparation of toner particles (C2)>
In the preparation of the toner particles (A1), after adjusting the pH to 8.5, the mixture was heated to 100 ° C. while continuing stirring, held for 10 hours, and then cooled to 20 ° C. at a rate of 1 ° C./min to 55 ° C. Toner particles (C2) were obtained in the same manner as the toner particles (A1) except that the mixture was reheated to 20 ° C., held for 0.2 hours, and cooled to 20 ° C. at a rate of 20 ° C./min.

<Preparation of toner particles (C3)>
Toner particles (C3) in the same manner as the toner particles (A1) except that the following silica particle dispersion (inorganic filler dispersion): 30 parts was used instead of the crystalline resin particle dispersion (A1): 32 parts. ) Was obtained.
In the toner particles (C3), the content of the silica particles with respect to the amorphous resin was 7% by mass.

(Preparation of silica particle dispersion)
-Silica particles (manufactured by Shin-Etsu Chemical Co., Ltd., QSG-100): 70 parts-Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts-Ion-exchanged water: 200 parts Mixing the above materials Then, the particles were dispersed for 10 minutes using a homogenizer (Ultratarax T50 manufactured by IKA). Ion-exchanged water was added so that the solid content in the dispersion was 20% by mass to obtain a silica particle dispersion in which silica particles having a volume average particle diameter of 110 nm were dispersed.

<Preparation of toner particles (C4)>
Crystalline resin particle dispersion (A1): Similar to toner particles (A1) except that 32 parts of the following PMMA particle dispersion (organic filler dispersion with high glass transition temperature) was used instead of 32 parts. , Toner particles (C4) were obtained.
In the toner particles (C4), the content of PMMA particles with respect to the amorphous resin was 7% by mass.

(Preparation of PMMA particle dispersion)
-PMMA (polymethylmethacrylate) particles (Soken Kagaku Co., Ltd., MP-1451, Tg128): 70 parts-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 30 parts-Ion-exchanged water: 200 parts Parts The above materials were mixed and dispersed for 10 minutes using a homogenizer (Ultratalax T50 manufactured by IKA). Ion-exchanged water was added so that the solid content in the dispersion was 20% by mass to obtain a PMMA particle dispersion in which PMMA particles having a volume average particle size of 150 nm were dispersed.

<Examples 1 to 7, Comparative Examples 1 to 4>
100 parts of each obtained toner particle and 0.7 part of dimethyl silicone oil-treated silica particle (RY200 manufactured by Nippon Aerosil Co., Ltd.) were mixed by a Henshell mixer to obtain the toner of each example.
Then, 8 parts of each obtained toner and 100 parts of the following carriers were mixed to obtain a developer of each example.

-Creation of carriers-
・ Ferrite particles (average particle size 50 μm) 100 parts ・ Toluene 14 parts ・ Styrene / methyl methacrylate copolymer (copolymerization ratio 15/85) 3 parts ・ Carbon black 0.2 parts The above components excluding ferrite particles are sand milled. A dispersion was prepared by dispersing, and the dispersion was placed in a vacuum degassing type kneader together with ferrite particles, and the pressure was reduced while stirring to dry the mixture to obtain a carrier.

<Measurement>
For the toner of the developer of each example, the area ratio a (%) of the crystalline resin existing in the cross section of the toner particles before heating according to the method described above [“Area ratio a of the crystalline resin before heating” in the table. ] And the area ratio b (%) of the crystalline resin existing in the cross section of the toner particles after heating [indicated as "the area ratio b of the crystalline resin after heating" in the table].
Further, according to the method described above, the domain diameter of the crystalline resin and the number of domains of the crystalline resin per unit area in the cross section of the toner particles were also determined.
These results are shown in Table 2.

<Evaluation>
The following evaluation was performed using the obtained developer. The results are shown in Table 2. The evaluation work and the image formation were performed in an environment of a temperature of 33 ° C. and a humidity of 90%.

[Evaluation of image defects by toner filming]
ApeosPort IV C4470 manufactured by Fuji Xerox Co., Ltd. was prepared as an image forming apparatus for forming an image for evaluation, the obtained developer was put into a developing device, and replenishing toner (the same toner as the toner contained in the developing agent) was put into a toner cartridge. I put it in. Subsequently, by an image forming apparatus, at a process speed of 445 mm / sec, high quality paper (P paper, manufactured by Fuji Xerox Co., Ltd., product name P, basis weight 64 g / m ² , paper thickness: 88 μm, temperature 33 ° C./humidity 90%). For 1 week), 25,000 5 cm × 5 cm halftone images having an image area ratio of 50% and 5 cm × 5 cm solid images having an image area ratio of 100% were continuously output. Then, the 10000th halftone image is visually evaluated for image quality defects due to toner filming, the 25000th halftone image is visually evaluated for image quality defects due to toner filming, and the solid image is bent. The strength was evaluated. The evaluation criteria are as follows.
Here, the image quality defect due to toner filming was evaluated for color unevenness in a halftone image due to toner filming on the surface of the charging roll.

The evaluation criteria are as follows. In addition, A and B were accepted.
A: No image quality defects due to toner filming.
B: Image quality defects (color unevenness) occur due to slight toner filming in a fractional manner (range less than 10% in a halftone image).
C: Image quality defects (color unevenness) occur partially (in the range of 10 to 50% of the halftone image) due to toner filming.
D: Image quality defects (color unevenness) occur due to toner filming on the entire surface (range exceeding 50% in the halftone image).

[Fixability evaluation]
As an evaluation of fixability, the image surface of the solid image part is bent using a weight with a constant load, the fold part is rubbed with gauze, and the degree of image defect caused by the rubbing is visually observed, and the image is imaged according to the following criteria. The bending strength of the was evaluated. In addition, G4 and G5 were accepted.
G1: At the same time as rubbing with gauze, the image is lost in the part other than the bent part, and it is almost not fixed.
G2: When rubbed with gauze, the bent portion and its surroundings become wide white streaks and the image is lost.
G3: When rubbed with gauze, the bent portion becomes a white streak and the image is lost, and the peripheral portion also cracks or the like.
G4: When rubbed with gauze, only the image defect of very thin white streaks occurs only in the bent portion. There is no problem in practical use.
G5: Even if rubbed with gauze, there is almost no image loss, and the history of bending can be seen.

From the above results, in this example, the occurrence of toner filming is suppressed even when an image is formed at a high process speed (conveyance speed of the recording medium) in a high temperature and high humidity environment as compared with the comparative example. It can be seen that the occurrence of image defects caused by this is also suppressed. It can also be seen that in this example, good fixing results were obtained.
However, in Comparative Examples 3 and 4, the occurrence of toner filming is suppressed, and the occurrence of image defects caused by the suppression is also suppressed, because silica particles or PMMA particles are mixed in the toner particles. , It can be seen that the fixability has deteriorated.

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 (7)

It has toner particles containing amorphous resin and crystalline resin, and has
When the toner particles are heated at a temperature of 50 ° C. and a humidity of 50% RH for 3 days, the area ratio a (%) of the crystalline resin present in the cross section of the toner particles before heating and the toner particles after heating relationship between the area ratio b (%) of the crystalline resin in the presence of the cross-section, the formula (1): meets 0.9 ≦ a / b ≦ 1.0,
The domain diameter of the crystalline resin is 5 nm or more and 15 nm or less.
Number of domains of the crystalline resin: 20 or more and 200 or less toners for static charge image development per unit area (1 μm × 1 μm). The toner for developing an electrostatic charge image according to claim 1, wherein the toner particles contain a bright pigment. A static charge image developer containing the toner for static charge image development according to claim 1 or 2. The toner for developing an electrostatic charge image according to claim 1 or 2 is accommodated and used.
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 3 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 that accommodates the electrostatic charge image developer according to claim 3 and develops 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 3.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.

Images