JP2015041073A - Toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development that suppresses, when a recording medium to which a toner image is fixed is stacked on another recording medium, set-off of the toner image on the another recording medium.SOLUTION: There is provided a toner for electrostatic charge image development containing an amorphous polyester resin and a crystalline polyester resin, where the amorphous polyester resin includes an amorphous polyester resin having an ethylenically unsaturated bond and a crosslinked product of the amorphous polyester resin having the ethylenically unsaturated bond in a surface layer; the maximum value of tanδ falls within a range of 50°C or more and 70°C or less; the maximum value of tanδ is 1 or more; and an average inclination the value of tanδ with respect to temperature is 0.10°Cwithin a range from a temperature lower than a temperature indicating the maximum value of tanδ by 10°C to a temperature lower than the temperature by 4°C.

Description

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

  In recent years, image forming apparatuses such as printers and copiers have been widely used, and technologies relating to various elements constituting the image forming apparatus have also been widely used. In an image forming apparatus adopting an electrophotographic method among image forming apparatuses, a photosensitive member (image holding member) is charged by using a charging device, and the electrostatic potential on the charged photosensitive member is different from the surrounding potential. In many cases, a pattern to be printed is formed by forming a charge image. The electrostatic image formed in this way is developed with a developer containing toner, and is finally transferred onto a recording medium such as recording paper.

  Here, it is possible to form a high-quality image, and furthermore, it has heat-resistant storage stability and excellent high-temperature offset resistance while having excellent low-temperature fixability, and has an appropriate gloss on the formed image. In order to provide a method for producing an electrostatic charge image developing toner capable of stably producing a toner that can be applied, an electrostatic charge comprising toner particles containing a binder resin containing at least a polyester resin having a crosslinked structure. A method for producing a toner for developing a charge image, comprising: (a-1) a step of producing an aqueous medium dispersion of fine particles of a crystalline polyester resin; (a-2) a non-containing composition containing a polymerizable unsaturated double bond. A step of producing an aqueous medium dispersion of fine particles from the crystalline polyester resin, (b) in the aqueous medium, at least the fine particles from the crystalline polyester resin and the polymerizable unsaturated After passing through the step of agglomerating fine particles of an amorphous polyester resin containing a bond to form aggregated particles, (c) a radical polymerization reaction is performed by causing a radical polymerization initiator to act on the aggregated particles to form a crosslinked structure A method for producing a toner for developing an electrostatic charge image, which is characterized by undergoing a step of producing a polyester resin having a toner (see, for example, Patent Document 1).

JP 2012-141523 A

  According to the present invention, after the toner image is fixed on the recording medium and before the recording medium is cooled, the back-off of the toner image to the recording medium when the recording medium on which the toner image is fixed is stacked is suppressed. An object is to provide a toner for developing an electrostatic image.

Specific means for achieving the above object are as follows.
That is, the invention according to claim 1
Containing an amorphous polyester resin and a crystalline polyester resin,
The amorphous polyester resin includes an amorphous polyester resin having an ethylenically unsaturated bond,
The surface layer portion includes a crosslinked product of the amorphous polyester resin having the ethylenically unsaturated bond,
the maximum value of tan δ is in the range of 50 ° C. or higher and 70 ° C. or lower,
The maximum value of tan δ is 1 or more,
Wherein a toner for developing electrostatic images average slope is 0.10 ° C. ^-1 or more for the temperature of the tan [delta values in the range of from 10 ° C. lower temperature to 4 ° C. lower than the temperature showing the maximum value of the tan [delta.

The invention according to claim 2
The melting temperature of the crystalline polyester resin is 70 ° C. or higher,
2. The electrostatic image developing toner according to claim 1, wherein the ratio of the structural unit derived from fumaric acid to the total amount of the structural unit derived from the carboxylic acid component constituting the crystalline polyester resin is 30 mol% or more.

The invention according to claim 3
An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1.

The invention according to claim 4
Containing the toner for developing an electrostatic image according to claim 1;
The toner cartridge is detachable from the image forming apparatus.

The invention according to claim 5
A developing unit that contains the electrostatic charge image developer according to claim 3 and that develops the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer.
It is a process cartridge that can be attached to and detached from the image forming apparatus.

The invention according to claim 6
An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
A developing means for containing the electrostatic charge image developer according to claim 3 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
An image forming apparatus.

The invention according to claim 7 provides:
A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 3;
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image transferred to the surface of the recording medium;
Is an image forming method.

According to the first or second aspect of the invention, the toner image is fixed after the toner image is fixed to the recording medium and before the recording medium is cooled, as compared with the case without this configuration. There is provided a toner for developing an electrostatic charge image, in which the transfer of toner images to the recording medium when the recording media are stacked is suppressed.
According to the third aspect of the present invention, the recording medium on which the toner image is fixed is fixed after the toner image is fixed on the recording medium and before the recording medium is cooled, as compared with the case where this configuration is not provided. Provided is an electrostatic charge image developer that suppresses the transfer of toner images to a recording medium when stacked.
According to the fourth aspect of the present invention, the recording medium on which the toner image is fixed is fixed after the fixing of the toner image to the recording medium and before the recording medium is cooled, as compared with the case without this configuration. Provided is a toner cartridge that accommodates toner for developing an electrostatic charge image that prevents the toner images from being transferred to the recording medium when stacked.
According to the fifth aspect of the present invention, the recording medium on which the toner image is fixed is fixed after the fixing of the toner image to the recording medium and before the recording medium is cooled, as compared with the case without this configuration. The handling of the electrostatic image developer, in which the toner image is prevented from being transferred to the recording medium when stacked, makes it easy to handle the image forming apparatus having various configurations.
According to the sixth aspect of the present invention, the recording medium on which the toner image is fixed is fixed after the fixing of the toner image onto the recording medium and before the recording medium is cooled, as compared with the case without this configuration. There is provided an image forming apparatus using an electrostatic charge image developer that suppresses the back-off of toner images to a recording medium when stacked.
According to the seventh aspect of the present invention, compared to the case without this configuration, the recording medium on which the toner image is fixed after the fixing of the toner image to the recording medium and before the recording medium cools down. Provided is an image forming method using an electrostatic charge image developer that prevents the toner image from being transferred to the recording medium when stacked.

It is a figure which shows an example of the measurement result of tan-delta about a toner. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

  Hereinafter, embodiments of an electrostatic image developing toner, an electrostatic image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method of the present invention will be described in detail.

<Toner for electrostatic image development>
The electrostatic image developing toner according to the exemplary embodiment (hereinafter sometimes simply referred to as “toner”) contains an amorphous polyester resin and a crystalline polyester resin, and the amorphous polyester resin is , Including an amorphous polyester resin having an ethylenically unsaturated bond, the surface layer portion including a crosslinked product of the amorphous polyester resin having the ethylenically unsaturated bond, and the maximum value of tan δ is 50 ° C. or higher and 70 ° C. or lower. In which the maximum value of tan δ is 1 or more, and the average slope of the tan δ value with respect to the temperature in the range from a temperature 10 ° C. to a temperature 4 ° C. lower than the temperature at which the maximum value of tan δ is 0. 10 ° C. ⁻¹ or higher.

  Conventionally, in order to achieve low-temperature fixability of toner, a crystalline resin such as a crystalline polyester resin has been used as a fixing aid. By incorporating a crystalline polyester resin in the toner, low temperature fixability is obtained. However, in fanless machines (printers and copiers without a cooling fan mechanism) that are also being developed from the viewpoint of energy saving and the environment, the internal temperature rises during continuous printing, and the toner on the recording medium is accordingly accompanied. When the recording medium discharged after fixing the image becomes high temperature and the recording medium on which the toner image is fixed is stacked before the recording medium cools down, the toner image may fall to the recording medium. It was.

The toner according to the present embodiment is the back of the toner image on the recording medium when the recording medium on which the toner image is fixed is stacked after the fixing of the toner image onto the recording medium and before the recording medium cools down. Transfer is suppressed. The reason is not clear, but is presumed as follows.
The tan δ of the toner can be cited as one of the indices indicating the physical properties of the toner at the temperature at which tan δ is measured. When tan δ is 1 or more, the physical properties of the toner are dominant in viscosity, and when tan δ is 1 or less, the physical properties of the toner are elastic. Further, the temperature at which the tan δ of the toner exhibits a maximum value can be cited as one index indicating the glass transition temperature of the toner. If the average slope with respect to the temperature of the tan δ value in the range from a temperature lower by 10 ° C. to a temperature lower by 4 ° C. than the temperature at which tan δ exhibits the maximum value is 0.10 ° C. ⁻¹ or more, the recording medium is cooled after fixing the toner image When this is done, the temperature range at which the physical properties of the toner are converted from viscosity-dominated to elastic-dominated is reduced. For this reason, it is presumed that the toner physical properties that are viscous in cooling after fixing of the toner image are likely to become quickly and elastic. Furthermore, although the surface layer portion of the toner according to the exemplary embodiment includes a crosslinked product of an amorphous polyester resin having an ethylenically unsaturated bond, it is assumed that the presence of the crosslinked product tends to make the toner physical properties elastic. It is assumed that the physical property of the toner becomes elastic, thereby preventing the toner image from being transferred to the recording medium.

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

  The toner according to the exemplary embodiment includes toner particles and, if necessary, external additives.

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

-Binder resin-
In the present embodiment, an amorphous polyester resin and a crystalline polyester resin are used in combination as the binder resin. Further, the amorphous polyester resin includes an amorphous polyester resin having an ethylenically unsaturated bond (hereinafter sometimes referred to as an amorphous unsaturated polyester resin). In this embodiment, an amorphous unsaturated polyester resin is used as at least a part of the amorphous polyester resin. In this embodiment, in order to distinguish from an amorphous unsaturated polyester resin, the bond does not have an ethylenically unsaturated bond or the bond is reactive even if it has an ethylenically unsaturated bond. An amorphous polyester resin that is not used may be referred to as an amorphous saturated polyester resin.

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

-Amorphous saturated polyester resin As an amorphous saturated polyester resin, the condensation polymer of polyhydric carboxylic acid and polyhydric alcohol is mentioned, for example. In addition, as an amorphous saturated polyester resin, a commercial item may be used and what was synthesize | combined may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (for example, cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids ( For example, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or lower (for example, having 1 to 5 carbon atoms) alkyl esters thereof. Among these, as polyvalent carboxylic acid, aromatic dicarboxylic acid is preferable, for example.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (for example, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (for example, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). 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 together with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

The glass transition temperature (Tg) of the amorphous saturated polyester 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 determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, described in the method for determining the glass transition temperature in JIS K7121-1987 “Method for Measuring Transition Temperature of Plastic”. It is determined by “extrapolated glass transition start temperature”.

The weight average molecular weight (Mw) of the amorphous saturated polyester resin is preferably from 5,000 to 1,000,000, more preferably from 7,000 to 500,000.
The number average molecular weight (Mn) of the amorphous saturated polyester resin is preferably from 2,000 to 100,000.
The molecular weight distribution Mw / Mn of the amorphous saturated polyester 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 performed with a THF solvent using a Tosoh GPC / HLC-8120 as a measuring device and a Tosoh column / TSKgel Super HM-M (15 cm). The weight average molecular weight and the number average molecular weight are calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample from this measurement result.

The amorphous saturated polyester resin is obtained by a known production method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure in the reaction system is reduced as necessary, and the reaction is performed while removing water and alcohol generated during the condensation.
In addition, when the monomer of the raw material is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added and dissolved as a solubilizing agent. In this case, the polycondensation reaction is performed while distilling off the solubilizer. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polymerized together with the main component. It is good to condense.

Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. In addition, as a crystalline polyester resin, a commercial item may be used and what was synthesize | combined may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic group is preferable to a polymerizable monomer having an aromatic group.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, fumaric acid, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1, 10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acids (eg phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2) , 6-dicarboxylic acid and the like), their anhydrides, or lower (for example, having 1 to 5 carbon atoms) alkyl esters.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. 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.), these Examples thereof include anhydrides and lower (for example, having 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group or a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

  In the present embodiment, the proportion of the structural unit derived from fumaric acid in the total amount of the structural unit derived from the carboxylic acid component constituting the crystalline polyester resin is preferably 30 mol% or more, and 60 mol% or more. More preferably, it is more preferably 70 mol% or more, and it is extremely preferable that it contains substantially no structural unit derived from other carboxylic acid components other than the structural unit derived from fumaric acid, and constitutes a crystalline polyester resin. It is particularly preferable that the ratio of the structural unit derived from fumaric acid in the total amount of the structural unit derived from the carboxylic acid component is 100 mol%.

Examples of the polyhydric alcohol include aliphatic diols (for example, linear aliphatic diols having a main chain portion having 7 to 20 carbon atoms). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples include octadecanediol and 1,14-eicosandecanediol. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable as the aliphatic diol.
The polyhydric alcohol may be used in combination with a diol and a trivalent or higher alcohol having a crosslinked structure or a branched structure. Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

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

The melting temperature of the crystalline polyester resin is preferably 70 ° C. or higher, more preferably 75 ° C. or higher, and still more preferably 80 ° C. or higher. Moreover, it is preferable that the melting temperature of crystalline polyester resin is 130 degrees C or less.
The melting temperature is determined from the “melting peak temperature” described in the method for determining the melting temperature of JIS K7121-1987 “Method for measuring the transition temperature of plastic” from the DSC curve obtained by differential scanning calorimetry (DSC).

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

  The crystalline polyester resin can be obtained by a known production method, for example, similarly to the amorphous saturated polyester resin.

-Amorphous unsaturated polyester resin The amorphous unsaturated polyester resin used in the present embodiment is not particularly limited as long as it has an ethylenically unsaturated bond having reactivity in the molecule. However, the reactivity referred to in this embodiment means that the resin is heated to 80 ° C. while stirring the 30 mass% aqueous dispersion as fine particles of about 200 nm, and a 5 mass% polymerization initiator (APS) (APS). , Manufactured by Mitsubishi Chemical Co., Ltd.) and reacted for 2 hours, and the gel content (THF insoluble content) of the resin particles solid-separated by a freeze dryer increased by 3% by mass or more before and after the reaction. Hereinafter, the ethylenically unsaturated bond having reactivity may be simply referred to as an ethylenically unsaturated bond or an unsaturated bond.
The unsaturated bond equivalent of the amorphous unsaturated polyester resin used in the present embodiment is preferably 4000 g / eq or less, more preferably 1500 g / eq or less, and particularly preferably 1000 g / eq or less. desirable.

In the present embodiment, the unsaturated bond equivalent of the resin refers to a value measured by the following method.
The NMR analysis (H analysis) of the resin is performed, the monomer type and composition ratio are identified, and the molecular weight per unsaturated bond is calculated by determining the proportion of the monomer having an unsaturated bond.

The amorphous unsaturated polyester resin is an amorphous polyester resin having an ethylenically unsaturated bond (for example, vinyl group or vinylene group) in the molecule.
Specifically, for example, the amorphous unsaturated polyester resin is a polycondensation product of a polyvalent carboxylic acid and a polyhydric alcohol, and an unsaturated polyester component is used as at least one of the polyvalent carboxylic acid and the polyhydric alcohol. It is preferable to use a monomer having an ethylenically unsaturated bond (for example, vinyl group or vinylene group).
In particular, from the viewpoint of stability, the amorphous unsaturated polyester resin is preferably a polyvalent carboxylic acid having an ethylenically unsaturated bond (for example, a vinyl group or vinylene group), and preferably a polyhydric alcohol. It is preferable that the polymer is a condensation polymer, and the amorphous unsaturated polyester resin includes a degeneration of a divalent carboxylic acid having an ethylenically unsaturated bond (for example, a vinyl group or vinylene group) and a divalent alcohol. It is good that it is a coalescence (that is, a linear polyester resin).
When the amorphous unsaturated polyester resin is a polycondensation product of a polyvalent carboxylic acid having an ethylenically unsaturated bond and a polyhydric alcohol, a polyvalent carboxylic acid having no ethylenically unsaturated bond may be added as necessary. , And may be used as part of a polyvalent carboxylic acid. Specific examples of the polyvalent carboxylic acid having no ethylenically unsaturated bond include the polyvalent carboxylic acids mentioned in the section of the amorphous saturated polyester resin.

Examples of the divalent carboxylic acid having an ethylenically unsaturated bond (for example, vinyl group or vinylene group) include fumaric acid, maleic acid, maleic anhydride, citraconic acid, mesaconic acid, itaconic acid, glutaconic acid, and allylmalonic acid. Acetylene dicarboxylic acid, and lower (1 to 4 carbon atoms) alkyl esters thereof. In view of reactivity, the ethylenically unsaturated bond is preferably located in the main chain or a portion close to the main chain when condensed into a polyester, and the alkenyl succinic acid has an unsaturated bond in the side chain far from the main chain. Since such a monomer has poor reactivity, it is not treated here as a polyvalent carboxylic acid having an unsaturated bond.
Examples of the trivalent or higher carboxylic acid having an ethylenically unsaturated bond (for example, vinyl group or vinylene group) include aconitic acid, 3-butene-1,2,3-tricarboxylic acid, 4-pentene-1,2,4, -Tricarboxylic acid, 1-pentene-1,1,4,4, -tetracarboxylic acid, and these lower (C1-C4) alkylesters are mentioned.
These polyvalent carboxylic acids may be used alone or in combination of two or more.

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

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

  The proportion of the monomer having an ethylenically unsaturated bond in the total of the polyvalent carboxylic acid and polyhydric alcohol constituting the amorphous unsaturated polyester resin is preferably 5 mol% or more and 25 mol% or less, 7.5 More preferably, it is more than mol% and less than 22.5 mol%.

  There is no restriction | limiting in particular as a manufacturing method of an amorphous unsaturated polyester resin, You may use the method according to the case of the said amorphous saturated polyester resin.

  The weight average molecular weight (Mw) of the amorphous unsaturated polyester resin is, for example, preferably from 30,000 to 300,000, preferably from 30,000 to 200,000, more preferably from 35,000 to 150. , 000 or less.

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

The content of the binder resin is, for example, preferably 40% by weight to 95% by weight, more preferably 50% by weight to 90% by weight, and more preferably 60% by weight to 85% by weight with respect to the entire toner particles. Further preferred.
The ratio of the crystalline polyester resin in the entire binder resin is such that the content is in the range of 2% by mass to 40% by mass (preferably 2% by mass to 20% by mass) with respect to the total binder resin. Is good.
The proportion of the amorphous unsaturated polyester resin in the entire amorphous polyester resin is such that the content is 25% by mass or more and 100% by mass or less (preferably 45% by mass or more and 100% by mass) with respect to the total amorphous polyester resin. The following range is preferable.

-Colorant-
Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliantamine 3B, brilliant. Carmine 6B, Dupont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or acridine series, xanthene series, azo series Various dyes such as benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, and thiazole Can be mentioned.
A colorant may be used individually by 1 type and may use 2 or more types together.

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

  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 mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester types such as fatty acid esters and montanic acid esters Wax; and the like. 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 “melting peak temperature” described in the method for determining the melting temperature of JIS K7121-1987 “Method for measuring the transition temperature of plastic” from the DSC curve obtained by differential scanning calorimetry (DSC).

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

-Other additives-
Examples of other additives include known additives such as a magnetic material, a charge control agent, and inorganic powder. These additives are contained in the toner particles as internal additives.

-Toner particle characteristics-
The toner particles may be toner particles having a single layer structure, or toner particles having a so-called core / shell structure composed of a core (core particle) and a coating layer (shell layer) covering the core. May be.
Here, the core / shell structure toner particles include, for example, a core portion including a binder resin and, if necessary, other additives such as a colorant and a release agent, and a binder resin. It is good to be comprised with the comprised coating layer.

  In the toner according to the exemplary embodiment, the surface layer portion includes a crosslinked product of an amorphous unsaturated polyester resin. The toner according to the exemplary embodiment including the toner particles and, if necessary, the external additive, is configured such that the surface layer portion of the toner particles includes a crosslinked product of the amorphous unsaturated polyester resin. The

Whether or not the toner (toner particles) according to the exemplary embodiment includes a cross-linked product is confirmed by the following method.
To 2 g of toner or toner particles, 100 mL of dimethyl sulfoxide and 10 mL of a 5 mol / L sodium hydroxide-methanol solution are added and dispersed, and the hydrolysis reaction is allowed to proceed for 12 hours at room temperature (for example, 25 ° C.). Neutralize with. Thereafter, dimethylformamide is added to prepare a 0.5 mass% solution, and the molecular weight (number average molecular weight) of the hydrolyzed toner dispersion is measured by GPC. If the toner or toner particles contain a cross-linked product, a gentle peak appears in the region where the number average molecular weight is 3000 or more. The peak is derived from a crosslinked product of an amorphous unsaturated polyester resin formed by a polymerization reaction of an ethylenically unsaturated bond contained in the molecule of the amorphous unsaturated polyester resin. Whether or not the toner (toner particles) according to the exemplary embodiment includes a cross-linked product is determined based on the presence or absence of a gradual peak in a region where the number average molecular weight is 3000 or more.

Further, whether or not a cross-linked product is contained on the surface of the toner (toner particles) according to the present embodiment is confirmed by the following method.
A C-K shell NEXAFS (Near Edge X-Ray Absorption Fine Structure) spectrum of the toner surface layer portion and the central portion is obtained by STXM (Scanning Transmission X-ray Microscope). Next, for the peak in the vicinity of 288.7 eV derived from the ethylenically unsaturated bond, the background was subtracted at 288 eV and 290 eV to obtain the peak area, which was used as the C2p peak, and the C2p peak at the toner surface layer portion and the central portion was obtained. The abundance ratio of the ethylenically unsaturated bond between the surface layer portion and the central portion can be determined.
As a result of comparison, when the C2p peak of the toner surface layer portion is reduced as compared with the central portion, it can be said that the surface layer portion of the toner (toner particles) includes a cross-linked product.

  The volume average particle diameter (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.

In addition, various average particle diameters and various particle size distribution indexes of the toner particles are measured using Coulter Multisizer II (manufactured by Beckman-Coulter), and the electrolyte is measured using ISOTON-II (manufactured by Beckman-Coulter). The
In the measurement, 0.5 mg to 50 mg of a measurement sample is added as a dispersant to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate). This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolyte 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 to 60 μm is obtained using a 100 μm aperture with a Coulter Multisizer II. taking measurement. The number of particles to be sampled is 50,000.
A cumulative distribution is drawn from the smaller diameter side to the particle size range (channel) divided based on the measured particle size distribution, and the cumulative particle size of 16% is the volume particle size D16v. D16p, a particle size that is 50% cumulative is defined as a volume average particle size D50v, a cumulative number average particle size D50p, and a particle size that is 84% cumulative is defined as a volume particle size D84v and a number particle size D84p.
Using these, the volume average particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 and the number average particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

  The shape factor SF1 of the toner particles is preferably 110 or more and 150 or less, and more preferably 120 or more and 140 or less.

The shape factor SF1 is obtained by the following formula.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML represents the absolute maximum length of the toner, and A represents the projected area of the toner.
Specifically, the shape factor SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows. That is, by capturing an optical microscope image of particles dispersed on the surface of a slide glass into a Luzex image analyzer using a video camera, obtaining the maximum length and projected area of 100 particles, calculating by the above formula, and obtaining the average value can get.

The maximum value of tan δ for the toner according to the present embodiment is in the range of 50 ° C. or higher and 70 ° C. or lower. When the maximum value of tan δ is less than 50 ° C., toner blocking may occur. On the other hand, if the maximum value exceeds 70 ° C., the amount of heat energy required for fixing the toner image increases, and the low-temperature fixability may not be achieved.
One maximum value of tan δ may be present in the range of 50 ° C. or higher and 70 ° C. or lower. Further, when the maximum value of tan δ is 2 or more in the range of 50 ° C. or more and 70 ° C. or less, the binder resin in the toner is plural and incompatible. The image may become brittle and may not be practically usable. No toner that can withstand practical use has a maximum value of tan δ of 2 or more in the range of 50 ° C. or more and 70 ° C. or less.
The maximum value of tan δ for the toner according to the exemplary embodiment is 1 or more, but is preferably 1 or more and 2 or less, and more preferably 1.2 or more and 1.6 or less. If the maximum value of tan δ is less than 1, the toner may be excessively elastic and may cause problems such as weak adhesion to paper.
In the toner according to the present exemplary embodiment, the average slope of the tan δ value with respect to the temperature in the range from a temperature lower by 10 ° C. to a temperature lower by 4 ° C. than the temperature showing the maximum value of tan δ is 0.10 ° C. ⁻¹ or more. 0.12 ° C. ⁻¹ or more is preferable, and 0.13 ° C. ⁻¹ or more is more preferable. When the average slope of the tan δ value with respect to the temperature is less than 0.10 ° C.− ¹ , it may be difficult to prevent the toner image from being transferred to the recording medium.

  In the present embodiment, tan δ (tan Delta: dynamic loss tangent of dynamic viscoelasticity) is obtained by measuring storage elastic modulus G ′ and loss elastic modulus G ″ by dynamic viscoelastic temperature dependence measurement. / G ′. Here, G ′ is an elastic response component of an elastic modulus in the relationship of stress generated with respect to strain at the time of deformation, and energy for deformation work is stored. The viscosity response component of the elastic modulus is G ″. Further, tan δ defined by G ″ / G ′ is a measure of the ratio of energy loss to storage work and storage.

  The storage elastic modulus G ′ and the loss elastic modulus G ″ can be measured using, for example, a rotating plate rheometer (manufactured by TA Instruments: ARES). As an example of the measurement, a rheometer (manufactured by Rheometric Scientific Co., Ltd .: ARES rheometer) is used, and a temperature rise measurement is performed under the condition of a frequency of 1 [Hz] using a parallel plate. The sample set was performed at about 120 [° C.] to 140 [° C.], cooled to room temperature (30 ° C. or lower), held at 30 ° C. for 3 hours, and then heated at a heating rate of 2 [° C./min]. For each [° C.], the storage elastic modulus G ′, loss elastic modulus G ″, and tan δ at the time of temperature increase are measured.

A sample subjected to tan δ measurement is prepared by the following method.
By molding the toner or toner particles to be measured into a tablet mold at room temperature (for example, 25 ° C.) using a press molding machine, a sample having almost no voids between the toner particles can be produced. Using this, tan δ measurement is performed.

FIG. 1 is a diagram illustrating an example of a measurement result of tan δ for toner. In the figure, the temperature showing the maximum value of tan δ is approximately 55 ° C. In FIG. 1, the average slope of the tan δ value with respect to the temperature in the range from a temperature lower by 10 ° C. to a temperature lower by 4 ° C. than the temperature showing the maximum value of tan δ (approximately 55 ° C.) is 0.13 ° C.- ¹ .

A method of calculating the average slope of the tan δ value with respect to the temperature in the range from the temperature 10 ° C. to the temperature 4 ° C. lower than the temperature at which the maximum value of tan δ is obtained from the measurement result of tan δ is as follows.
For the measured temperature [° C.] and tan δ, by applying the least squares method to a data set ranging from a temperature 10 ° C. to a temperature 4 ° C. lower than the temperature at which the maximum value of tan δ is exhibited, The slope of the approximate straight line can be obtained. This slope is the average slope.

In this embodiment, as a method for adjusting the tan δ of the toner, for example, the melting temperature is 70 ° C. or higher, and the proportion of the structural unit derived from fumaric acid in the total amount of structural units derived from the carboxylic acid component is 30 mol% or higher. By using a certain crystalline polyester resin, the inclination of tan δ with respect to the temperature is adjusted to be 0.10 ° C. ⁻¹ or more. In addition, by adjusting the glass transition temperature of the amorphous unsaturated polyester resin or the amorphous saturated polyester resin, or by controlling the compatibility of the amorphous polyester resin with the crystalline polyester resin, the maximum of tan δ is achieved. The temperature that reaches the value is adjusted.

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

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

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

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

  Specifically, for example, when toner particles are produced by an aggregation and coalescence method, a step of preparing a resin particle dispersion in which resin particles serving as a binder resin are dispersed (resin particle dispersion preparation step), and resin particles Step of agglomerating resin particles (other particles as required) to form aggregated particles in the dispersion (if necessary after mixing with other particle dispersions) (aggregated particle formation) Step) and heating the agglomerated particle dispersion in which the agglomerated particles are dispersed, and fusing and coalescing the agglomerated particles to form toner particles (fusing and coalescing step). Manufacturing.

In the production of toner particles, a cross-linking step or a toner in which the amorphous unsaturated polyester resin present in the surface layer portion of the toner particles is crosslinked so that the surface layer portion of the toner particles contains a cross-linked product of the amorphous unsaturated polyester resin. You may implement the adhesion process which adheres the resin particle containing the crosslinked material of an amorphous unsaturated polyester resin to the surface of particle | grains.
In the cross-linking step, for example, an amorphous unsaturated polyester resin present on the surface of the toner particles by adding a polymerization initiator to the toner particle dispersion containing the toner particles before cross-linking after the fusion and coalescence step. A crosslinked product of an amorphous unsaturated polyester resin may be formed on the surface of the toner particles by polymerizing.
On the other hand, in the attaching step, for example, a step of forming second agglomerated particles described later using a resin particle dispersion containing crosslinked particles obtained by crosslinking an amorphous unsaturated polyester resin is performed on the surface of the toner particles. You may make the resin particle containing the crosslinked material of an amorphous unsaturated polyester resin adhere.
By performing the above-described crosslinking step or adhesion step, the toner surface layer portion according to the exemplary embodiment may be configured to include a crosslinked product of an amorphous unsaturated polyester resin.
When toner particles are produced by the kneading and pulverizing method, the toner particles produced by the kneading and pulverizing method are dispersed in an aqueous medium, and a polymerization initiator is added to the medium so that the amorphous particles present on the surface of the toner particles. A cross-linked product of the amorphous unsaturated polyester resin may be formed on the surface of the toner particles by polymerizing the polymerizable unsaturated polyester resin.

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

-Preparation step of resin particle dispersion-
First, together with a resin particle dispersion in which resin particles to be a binder resin are dispersed, for example, a colorant particle dispersion in which colorant particles are dispersed and a release agent dispersion in which release agent particles are dispersed are prepared. .

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

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

Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an anionic surfactant and a cationic surfactant are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
Surfactant may be used individually by 1 type and may use 2 or more types together.

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

The volume average particle size 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. .
In addition, the volume average particle diameter of the resin particles is based on the particle size range (channel) divided by using the particle size distribution obtained by measurement with a laser diffraction particle size distribution measuring apparatus (for example, LA-700 manufactured by Horiba, Ltd.). The cumulative distribution is subtracted from the small particle diameter side with respect to the volume, and the particle diameter that becomes 50% cumulative with respect to all the particles is measured as the volume average particle diameter D50v. The volume average particle size of particles in other dispersions is also measured in the same manner.

  As content of the resin particle contained in a resin particle dispersion liquid, 5 to 50 mass% is preferable, for example, and 10 to 40 mass% is more preferable.

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

-Aggregated particle formation process-
Next, the colorant particle dispersion and the release agent dispersion are mixed together with the resin particle dispersion.
Then, in the mixed dispersion, resin particles, colorant particles, and release agent particles are hetero-aggregated to have resin particles, colorant particles, and release agent particles having a diameter close to the diameter of the target toner particles. Aggregated particles are formed.

Specifically, for example, the flocculant is added to the mixed dispersion, and 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 glass transition temperature (specifically, for example, the glass transition temperature of the resin particles −30 ° C. or more and the glass transition temperature −10 ° C. or less), and the particles dispersed in the mixed dispersion liquid are aggregated. , Forming aggregated particles.
In the agglomerated particle forming step, for example, the aggregating agent is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is acidic (for example, the pH is 2 or more and 5 or less). ), And after adding a dispersion stabilizer as necessary, the heating may be performed.

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

Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic substances such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include metal salt polymers.
A water-soluble chelating agent may be used as the chelating agent. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid, iminodiacid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), and the like.
The addition amount of the chelating agent 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 aggregated particle dispersion in which the aggregated particles are dispersed is heated to, for example, a glass transition temperature or higher of the resin particles (for example, a temperature of 10 to 30 ° C. higher than the glass transition temperature of the resin particles). Are fused and united to form toner particles.

Through the above steps, toner particles are obtained.
In addition, after obtaining the aggregated particle dispersion liquid in which the aggregated particles are dispersed, the aggregated 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 aggregated particles. A process of aggregating to adhere to form second aggregated particles, and heating the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and coalesce the second aggregated particles. The toner particles may be manufactured through a step of forming toner particles having a core / shell structure.

Here, after the fusion / unification process is completed, the above-described crosslinking process is performed as necessary, and then the toner particles formed in the solution are subjected to a known washing process, solid-liquid separation process, and drying process. Dry toner particles are obtained.
In the washing step, it is preferable to sufficiently carry out substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, etc. are preferably performed from the viewpoint of productivity. Also, the drying process is not particularly limited, but from the viewpoint of productivity, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying, or the like is preferably performed.

The polymerization initiator used in the crosslinking step is not particularly limited.
Examples of the polymerization initiator used in the present embodiment include, as a water-soluble polymerization initiator, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, and chloroperoxide. Benzoyl, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, Tert-butyl hydroperoxide pertriphenyl acetate, tert-butyl performate, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenyl acetate, tert-butyl permethoxyacetate, per-N- (3-toluyl) ) Vammin acid tert- butyl, ammonium bisulfate, sodium bisulfate, peroxides and the like; and others as mentioned, not limited to these.
Examples of the oil-soluble polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 1,1′-azobis (cyclohexane-1). -Carbonitrile), and azo polymerization initiators such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile.

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

Next, a method for producing toner particles by the dissolution suspension method will be described in detail.
In the dissolution suspension method, a binder resin and a material containing other components such as a colorant and a release agent used as necessary are dissolved or dispersed in a solvent in which the binder resin can be dissolved. In this method, the liquid is granulated in an aqueous medium containing an inorganic dispersant, and then the solvent is removed to obtain toner particles.
Other components used in the dissolution suspension method include various components such as an internal additive, a charge control agent, inorganic powder (inorganic particles), and organic particles, in addition to the colorant and the release agent.

  In this embodiment, these binder resins and other components used as necessary are dissolved or dispersed in a solvent in which the binder resin can be dissolved. Whether or not the binder resin can be dissolved depends on the components of the binder resin, the molecular chain length, the degree of three-dimensionalization, etc., so it cannot be generally stated, but in general, toluene, xylene, hexane, etc. Halogenated hydrocarbons such as hydrocarbons, methylene chloride, chloroform, dichloroethane, dichloroethylene, alcohols or ethers such as ethanol, butanol, benzyl alcohol ethyl ether, benzyl alcohol isopropyl ether, tetrahydrofuran, tetrahydropyran, methyl acetate, ethyl acetate, butyl acetate Esters such as isopropyl acetate, ketones such as acetone, methyl ethyl ketone, diisobutyl ketone, dimethyl oxide, diacetone alcohol, cyclohexanone, methylcyclohexanone, or acetals are used.

  These solvents dissolve the binder resin and do not need to dissolve other components such as a colorant and a release agent. Other components such as a colorant and a release agent may be dispersed in the binder resin solution. Although there is no restriction | limiting in the usage-amount of a solvent, What is necessary is just a viscosity which can be granulated in an aqueous medium. 10/90 to 50/50 (the mass ratio of the former / the latter) is granulated in the ratio of the material (the former) containing the other components such as the binder resin, the colorant and the release agent to the solvent (the latter). It is preferable in terms of easiness and final toner particle yield.

  The liquid (toner mother liquid) of other components such as a binder resin, a colorant, and a release agent dissolved or dispersed in a solvent has a predetermined particle size in an aqueous medium containing an inorganic dispersant. Granulated. As the aqueous medium, water is mainly used. The mixing ratio of the aqueous medium and the toner mother liquid is preferably aqueous medium / mother liquid = 90/10 to 50/50 (mass ratio). The inorganic dispersant is preferably selected from tricalcium phosphate, hydroxyapatite, calcium carbonate, titanium oxide and silica powder. The amount of the inorganic dispersant used is determined according to the particle size of the granulated particles, but generally it is preferably used in the range of 0.1% by mass to 15% by mass with respect to the toner mother liquor. . When the content is 0.1% by mass or more, granulation is performed satisfactorily, and when the content is 15% by mass or less, generation of unnecessary fine particles is suppressed and target particles are obtained in a high yield.

In order to granulate the toner mother liquor in an aqueous medium containing an inorganic dispersant, an auxiliary agent may be added to the aqueous medium. Such auxiliaries include known cationic type, anionic type and nonionic type surfactants, and those of the anionic type are particularly preferred. For example, there are sodium alkylbenzene sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfonate, etc., and these are used in the range of 1 × 10 ⁻⁴ mass% to 0.1 mass% with respect to the toner mother liquor. preferable.

Granulation of the toner mother liquor in an aqueous medium containing an inorganic dispersant is preferably performed under shear. The toner mother liquid dispersed in the aqueous medium is desirably granulated to have an average particle size of 9 μm or less. Particularly, it is preferably 3.5 μm or more and 7 μm or less.
There are various dispersers as the apparatus provided with the shearing mechanism, and among them, a homogenizer is preferable. By using a homogenizer, a substance that is incompatible with each other (in this embodiment, an aqueous medium containing an inorganic dispersant and a toner mother liquor) is passed through a gap between the casing and the rotating rotor so that the liquid is contained in a liquid. And incompatible substances can be dispersed in the form of particles. As such a homogenizer, TK homomixer, line flow homomixer, auto homomixer (manufactured by Special Machine Industries Co., Ltd.), Silverson homogenizer (manufactured by Silverson), polytron homogenizer (manufactured by KINEMATICA AG), etc. There is.

  The stirring condition using the homogenizer is preferably 2 m / sec or more in terms of the peripheral speed of the rotor blades. If it is more than this, it will be easy to granulate. In the present embodiment, the solvent is removed after the toner mother liquor is granulated in an aqueous medium containing an inorganic dispersant. The removal of the solvent may be performed at room temperature (25 ° C.) and normal pressure, but since it takes a long time to remove, the removal is performed under a temperature condition that is lower than the boiling point of the solvent and has a difference from the boiling point of 80 ° C. or less. Is preferred. The pressure may be normal pressure or reduced pressure, but when reducing the pressure, it is preferably 20 mmHg or more and 150 mmHg or less.

The toner particles obtained by the dissolution suspension method are preferably washed with hydrochloric acid after removing the solvent. As a result, the inorganic dispersant remaining on the surface of the toner particles can be removed to obtain the original composition of the toner particles and improve the characteristics. Next, after carrying out a crosslinking step of crosslinking the amorphous unsaturated polyester resin present in the surface layer portion of the toner particles so that the surface layer portion of the toner particles contains a crosslinked product of the amorphous unsaturated polyester resin, dehydration, When dried, powder toner particles can be obtained.
The toner particles obtained by the dissolution suspension method are subjected to inorganic oxidation represented by silica, titania, and aluminum oxide for the purpose of charge adjustment, fluidity provision, charge exchangeability and the like, as in the case of the aggregation and coalescence method. An article or the like may be added and adhered as an external additive. In addition to the inorganic oxides described above, other components (particles) such as a charge control agent, organic particles, a lubricant, and an abrasive may be added as external additives.

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

There is no restriction | limiting in particular as a carrier, A well-known carrier is mentioned. As a carrier, for example, a coated carrier in which the surface of a core made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and mixed in a matrix resin; a porous magnetic powder is impregnated with a resin And a resin-dispersed carrier in which conductive particles are dispersed and blended in a matrix resin.
The magnetic powder dispersion type carrier, the resin impregnated type carrier, and the conductive particle dispersion type carrier may be a carrier 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 oxide, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

  Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

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, styrene-acrylic acid copolymer. Examples thereof include a polymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
Note that the coating resin and the matrix resin may contain other additives such as a conductive material.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating layer forming solution obtained by dissolving the coating resin and, if necessary, various additives in an appropriate solvent may 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 the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the surface of the core material, 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 the 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 Apparatus / 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 carrier, a charging unit that charges the surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and an electrostatic charge. Development means for containing an image developer and developing the electrostatic image formed on the surface of the image carrier as a toner image with the electrostatic image developer, and the toner image formed on the surface of the image carrier as a recording medium Transfer means for transferring to the surface of the recording medium, and fixing means for fixing the toner image transferred to the surface of the recording medium. The electrostatic charge image developer according to this embodiment is applied as the electrostatic charge image developer.

  In the image forming apparatus according to this embodiment, a charging process for charging the surface of the image carrier, an electrostatic charge image forming process for forming an electrostatic image on the surface of the charged image carrier, and an electrostatic charge according to this embodiment. A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with an image developer; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of the recording medium; An image forming method (an image forming method according to the present embodiment) including a fixing step of fixing the toner image transferred onto the surface of the recording medium is performed.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers a toner image formed on the surface of an image carrier to a recording medium; the toner image formed on the surface of the image carrier is transferred to an intermediate transfer member An intermediate transfer type apparatus that primarily transfers the toner image transferred to the surface of the intermediate transfer body and then secondary transfer the toner image to the surface of the recording medium; after the toner image is transferred, the surface of the image carrier before charging is cleaned. An apparatus provided with a cleaning unit; a known image forming apparatus such as an apparatus provided with a charge removing unit that discharges the surface of an image holding member by irradiating a discharge light after charging a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer unit includes, for example, an intermediate transfer body on which a toner image is transferred to the surface and a primary transfer that primarily transfers the toner image formed on the surface of the image holding body to the surface of the intermediate transfer body And a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto the surface of the recording medium.

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

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

FIG. 2 is a schematic configuration diagram illustrating the image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 2 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 and a support roll 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other in the left to right direction in the drawing. The vehicle travels in the direction toward the unit 10K. The support roll 24 is applied with a force 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. An intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K has yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The toner including the four color toners is supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. It should be noted that reference numerals with magenta (M), cyan (C), and black (K) are attached to the same parts as those of the first unit 10Y instead of yellow (Y). Description of the units 10M, 10C, and 10K will be omitted.

The first unit 10Y includes a photoreceptor 1Y that functions as an image holding member. Around the photoreceptor 1Y, a charging roll (an example of a charging unit) 2Y for charging the surface of the photoreceptor 1Y to a predetermined potential, and the charged surface is exposed by a laser beam 3Y based on a color-separated image signal. Then, an exposure device (an example of an electrostatic image forming unit) 3 that forms an electrostatic image, and a developing device (an example of a developing unit) 4Y that develops the electrostatic image by supplying toner charged to the electrostatic image, developed A primary transfer roll 5Y (an example of a primary transfer unit) that transfers a toner image onto the intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning unit) 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 disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described.
First, prior to operation, the surface of the photoreceptor 1Y is charged to a potential of −600V to −800V by the charging roll 2Y.
The photoreceptor 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 resistance (general resin resistance), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image having a yellow image pattern is formed on the surface of the photoreceptor 1Y.

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

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

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

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

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

  Thereafter, the recording paper P is fed into the pressure contact portions (nip portions) of a pair of fixing rolls in a fixing device (an example of a fixing unit) 28, and the toner image is fixed on the recording paper P to form a fixed image.

Examples of the recording paper P to which the toner image is transferred include plain paper used in electrophotographic copying machines, printers, and the like. In addition to the recording paper P, the recording medium may be an OHP sheet.
In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is also preferably smooth. For example, coated paper with the surface of plain paper coated with resin, art paper for printing, etc. are preferably used. Is done.

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

<Process cartridge / toner cartridge>
The process cartridge according to this embodiment will be described.
The process cartridge according to the present embodiment accommodates the electrostatic image developer according to the present embodiment, and develops the electrostatic image formed on the surface of the image carrier as a toner image by the electrostatic image developer. And a process cartridge that can be attached to and detached from the image forming apparatus.

  Note that the process cartridge according to the present embodiment is not limited to the above-described configuration, and other means such as a developing device and other units such as an image carrier, a charging unit, an electrostatic charge image forming unit, and a transfer unit, if necessary. And at least one selected from the above.

  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 description of the other parts will be omitted.

FIG. 3 is a schematic configuration diagram showing a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 3 is provided around the photosensitive member 107 and the photosensitive member 107 by, for example, a housing 117 provided with an attachment rail 116 and an opening 118 for exposure. A charging roller 108 (an example of a charging unit), a developing device 111 (an example of a developing unit), and a photoconductor cleaning device 113 (an example of a cleaning unit) are integrally combined and held to form a cartridge. Yes.
In FIG. 3, reference numeral 109 denotes an exposure device (an example of an electrostatic charge image forming unit), 112 denotes a transfer device (an example of a transfer unit), 115 denotes a fixing device (an example of a fixing unit), and 300 denotes a recording paper (a recording medium). An example).

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present exemplary embodiment is a toner cartridge that accommodates the toner according to the present exemplary embodiment and is detachable from the image forming apparatus. The toner cartridge contains toner for replenishment to be supplied to the developing means provided in the image forming apparatus.

  The image forming apparatus shown in FIG. 2 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K are attached and detached. The developing devices 4Y, 4M, 4C, and 4K each have their respective developing devices (colors). And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to the following examples.

(Each measurement method)
<Measuring method of particle size>
A method for measuring the particle diameter will be described.
When the particle diameter to be measured was 2 μm or more, Coulter-Multisizer-II type (manufactured by Coulter) was used as the measuring apparatus, and Isoton II (manufactured by Coulter) was used as the electrolyte.
Moreover, when the particle diameter to measure was less than 2 micrometers, it measured using the laser diffraction type particle size distribution measuring apparatus (LA-700, the Horiba make).

<Measurement method of molecular weight>
The molecular weight was measured under the following conditions. GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)” apparatus, and two columns use “TSKgel, SuperHM-H (manufactured by Tosoh Corporation, 6.0 mm ID × 15 cm)”. , THF (tetrahydrofuran) was used as an eluent. As experimental conditions, an experiment was performed using a sample concentration of 0.5 mass%, a flow rate of 0.6 mL / min, a sample injection amount of 10 μL, a measurement temperature of 40 ° C., and an RI detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

<Measuring method of glass transition temperature>
The glass transition temperature was measured by a DSC (Differential Scanning Calorimeter) measurement method, and a main maximum peak measured in accordance with ASTM D3418-8 was obtained to obtain a glass transition temperature.

  DSC-7 manufactured by PerkinElmer was used for measurement of the main maximum peak. The temperature correction of the detection part of this apparatus was performed using the melting temperature of indium and zinc, and the heat amount was corrected using the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.

<Confirmation of whether or not the surface layer portion contains a cross-linked product>
Whether or not the surface layer portion of the toner (toner particles) contains a crosslinked product was confirmed by the above-described method.

<Measurement of tan δ>
The tan δ of the toner was measured by the method described above. Based on the obtained measurement results, the peak temperature of tan δ, the maximum value of tan δ, and the average slope of the tan δ value with respect to the temperature were obtained.

(Synthesis of amorphous polyester resin)
-Polyester resin having an ethylenically unsaturated double bond-
80 mol parts of bisphenol A propylene oxide 2 mol adduct, 20 mol parts of bisphenol A ethylene oxide 2 mol adduct, 10 mol parts of terephthalic acid, 30 mol parts of dodecenyl succinic acid, 40 mol parts of fumaric acid, 0.1 mol part of dibutyltin oxide, Was put into a heat-dried three-necked flask, and the air in the container was depressurized by a depressurization operation. Further, the atmosphere was inerted with nitrogen gas, and mechanical stirring was performed at 230 ° C. and normal pressure (101.3 kPa) for 10 hours. The reaction was further continued at 8 kPa for 1 hour. After cooling to 210 ° C. and adding 10 mole parts of trimellitic anhydride and reacting for 1 hour, the reaction was continued at 8 kPa until the softening temperature was 115 ° C. to obtain an amorphous polyester resin.
The glass transition temperature of the amorphous polyester resin was 60 ° C.

(Preparation of amorphous polyester resin particle dispersion)
500 parts by mass of an amorphous polyester resin, 320 parts by mass of methyl ethyl ketone, 125 parts by mass of isopropyl alcohol, and 5.0 parts by mass of a 10% by mass ammonia aqueous solution are placed in a separable flask, mixed, dissolved, and heated at 50 ° C. While stirring, ion-exchanged water was dropped with a liquid feed pump. Thereafter, the solvent was removed under reduced pressure. After adding 50 parts by mass of a 20% by mass aqueous sodium dodecylbenzenesulfonate solution to the solvent-removed amorphous polyester resin particle dispersion, ion-exchanged water is added to adjust the solid content concentration to 40% by mass. A resin particle dispersion was obtained. The obtained polyester resin particles had a volume average particle size of 190 nm.

(Synthesis of crystalline polyester resin)
Into a heat-dried three-necked flask, 45 mol parts of 1,9-nonanediol, 55 mol parts of fumaric acid, and 0.05 mol parts of dibutyltin oxide were introduced, and nitrogen gas was introduced into the container to keep it in an inert atmosphere. After heating, the polycondensation reaction is carried out at 150 ° C. to 230 ° C. for 2 hours, and then the temperature is gradually raised to 230 ° C. and stirred for 5 hours. When a viscous state is obtained, the reaction is stopped and the crystallinity is stopped. A polyester resin was synthesized.

(Preparation of crystalline polyester resin particle dispersion)
3000 parts by mass of the obtained crystalline polyester resin, 10000 parts by mass of ion-exchanged water, and 60 parts by mass of sodium dodecylbenzenesulfonate were charged into an emulsification tank of a high-temperature, high-pressure emulsification apparatus (Cabitron CD1010), and then heated and melted to 130 ° C. Thereafter, the mixture was dispersed at 110 ° C. at a flow rate of 3 L / m and 10,000 rpm for 30 minutes, and passed through a cooling tank to prepare a crystalline polyester resin particle dispersion having a solid content of 40 mass% and a volume average particle diameter D50v of 125 nm.

(Preparation of colorant dispersion)
50 parts by mass of carbon black (Regal 330 Cabot), 2.5 parts by mass of ionic surfactant Neogen R (Daiichi Kogyo Seiyaku), and 150 parts by mass of ion-exchanged water were mixed, and 10 by a homogenizer (IKA Ultra Tarrax). After dispersing for a minute and then using an optimizer, the solid content was adjusted to 30% by mass with ion-exchanged water to obtain a colorant dispersion having a central particle size of 245 nm.

(Preparation of release agent dispersion)
50 parts by weight of paraffin wax (manufactured by Nippon Seiki Co., Ltd., HNP9), 2.5 parts by weight of ionic surfactant Neogen R (Daiichi Kogyo Seiyaku) and 150 parts by weight of ion-exchanged water are heated to 120 ° C. After dispersing with a gorin homogenizer, the solid content was adjusted to 30% by mass with ion-exchanged water to obtain a release agent dispersion having a center particle size of 219 nm.

[Example 1]
(Preparation of Toner 1)
Amorphous polyester resin particle dispersion 638 parts by weight, crystalline polyester resin particle dispersion 128 parts by weight, colorant dispersion 88 parts by weight, release agent dispersion 175 parts by weight, aluminum sulfate (manufactured by Wako Pure Chemical Industries) 2 .5 parts by mass, 50 parts by mass of 0.3M nitric acid aqueous solution, and 2050 parts by mass of ion-exchanged water are placed in a 3 liter reaction vessel equipped with a thermometer, pH meter, and stirrer, and the temperature is controlled from the outside with a mantle heater. And kept at a temperature of 30 ° C. and a stirring rotational speed of 150 rpm for 30 minutes.
25 mass parts of 10 mass% aluminum sulfate aqueous solution was added, disperse | distributing with a homogenizer (IKA Japan company_made: Ultra Tarax T50). Thereafter, a 0.3N aqueous nitric acid solution was added to adjust the pH in the aggregation process to 3.5. The temperature was raised to 50 ° C., and the particle size was measured with Coulter Multisizer II (aperture diameter: 100 μm, manufactured by Coulter, Inc.) to obtain an aggregate having a volume average particle size of 5.5 μm.
Next, 255 parts by mass of an additional amorphous polyester resin particle dispersion was added.

  Subsequently, after adding 40 parts by mass of a 10% by mass NTA (nitrilotriacetic acid) metal salt aqueous solution (Cyrest 70: manufactured by Crest Co., Ltd.), the pH was adjusted to 9.0 using a 1N aqueous sodium hydroxide solution. . Thereafter, the temperature was increased to 80 ° C. at a rate of temperature increase of 0.05 ° C./min and held at 80 ° C. for 3 hours.

  Next, nitrogen bubbling was carried out for 1 hour with the system maintained at 80 ° C., and the system was put under an inert atmosphere. Thereafter, 2 parts by mass of a polymerization initiator VA-057 (trade name of Wako Pure Chemical Industries, Ltd.) was added to 100 parts by mass of the fused particles in the obtained fused particle dispersion. Thereafter, polymerization was carried out at 80 ° C. for 5 hours, followed by cooling and filtration to obtain coarse toner particles (crosslinking step). This was further re-dispersed with ion-exchanged water and filtered, and washed until the electrical conductivity of the filtrate was 20 μS / cm or less, and then vacuum-dried in an oven at 40 ° C. for 5 hours. Thus, toner particles were obtained.

1.5 parts by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part by weight of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) with respect to 100 parts by weight of the obtained toner particles Were mixed for 30 seconds at 10,000 rpm using a sample mill (external addition step). Thereafter, toner 1 was prepared by sieving with a vibrating sieve having an opening of 45 μm.
Toner 1 had a volume average particle diameter of 5.6 μm and SF1 of 123. Further, the surface layer of the toner particles according to the toner 1 contained a crosslinked product of an amorphous polyester resin.
Table 1 shows the measurement results of toner tan δ.

(Development of developer)
100 parts by mass of ferrite particles (Powder Tech, volume average particle size 50 μm) and 1.5 parts by mass of a methyl methacrylate resin (Mitsubishi Rayon, molecular weight 95000) are placed in a pressure kneader together with 500 parts by mass of toluene. The mixture was stirred and mixed at 30 ° C. for 15 minutes, then heated to 70 ° C. while mixing under reduced pressure to distill off toluene, then cooled, and classified using a 105 μm sieve to obtain a resin-coated ferrite carrier.
This resin-coated ferrite carrier and the above-described toner 1 were mixed to prepare a two-component developer 1 having a toner concentration of 7% by mass.

(Evaluation)
Using a remodeling machine of Satera LBP5050 (manufactured by Canon), the toner in the toner cartridge and the developer in the developing device are respectively replaced with the toner 1 and the two-component developer 1 to form a solid image 1 of 5 cm × 4 cm, and the internal parameters Was adjusted so that the applied toner amount per area was 10 [g / m ² ].
Next, C2 paper (manufactured by Fuji Xerox) was used as the paper, and 100 images for evaluation were discharged by continuous printing. Within 10 seconds after the 100th paper was discharged, the 100 sheets of paper were discharged. An additional 2900 unprinted C2 papers were placed from above and allowed to stand for 17 hours or more.
100 sheets of printed paper were taken out from the stationary paper and peeled off, and the degree of set-off was evaluated by observing how much the paper and paper were adhered to each other by toner.
The obtained evaluation results are shown in Table 1.

(Evaluation criteria)
A: The paper is not adhered, the paper is peeled off without resistance, and there is no image loss.
○: When the paper is peeled off, there is no resistance or slight resistance, and there is no defect in the image or there is no practical problem.
X: When the paper is peeled off, a clear resistance is felt, or image loss due to an offset or the like becomes a practical problem.

[Example 2]
After stirring 50 parts by mass of the crystalline polyester resin and 255 parts by mass of the amorphous polyester resin, 34 parts by mass of the pigment dispersion, and 56 parts by mass of ethyl acetate used in Example 1, 75 parts by mass of the wax dispersion was added to the mixture. The resulting mixture was stirred well until uniform (this solution was designated as solution A). On the other hand, 100 parts by mass of a calcium carbonate dispersion in which 40 parts by mass of calcium carbonate is dispersed in 60 parts by mass of water, 99 parts by mass of a 2% by weight aqueous solution of Serogen BS-H (Daiichi Kogyo Seiyaku Co., Ltd.), and 157 parts by mass of water. Was stirred for 5 minutes using a homogenizer (Ultra Turrax: manufactured by IKA) (this liquid was designated as B liquid).
Furthermore, 345 parts by mass of the B liquid and 250 parts by mass of the A liquid were stirred using a homogenizer (Ultra Turrax: manufactured by IKA) to suspend the mixed liquid. The mixture was stirred with a propeller-type stirrer at room temperature (for example, 25 ° C.) and normal pressure for 48 hours to remove the solvent. Next, hydrochloric acid was added to the mixture to remove calcium carbonate, and the reaction mixture was washed with water.
Next, the mixture was again heated to 80 ° C. while stirring, 15 parts by mass of a polymerization initiator (sodium persulfate: manufactured by Mitsubishi Gas Chemical) was added, and the mixture was held at 80 ° C. for 30 minutes with stirring. Thereafter, it was washed with water, dried and classified to obtain toner particles. The average particle size of the toner particles was 6 μm.
After the external addition process, the same processing as in Example 1 was performed to obtain a toner, and the same evaluation was performed.
The obtained evaluation results are shown in Table 1.

[Example 3]
70 parts by mass of the amorphous polyester resin used in Example 1, 10 parts by mass of the crystalline polyester resin, 6 parts by mass of the colorant, and 3 parts by mass of WEP-5 (manufactured by NOF) as the release agent The obtained composition was kneaded with a Banbury mixer and then finely pulverized with a jet mill to obtain toner particles having an average particle diameter of 7.6 μm and a number average fraction of 10.0% of 5 μm or less.
200 parts by mass of the toner particles are dispersed in 1500 parts by mass of water in which 0.05% by mass of a nonionic surfactant polyoxyethylene nonylphenyl ether is dissolved, and a stirrer (three-one motor manufactured by Shinto Kagaku Co., Ltd.) is obtained until it is uniformly wet. ) For 30 minutes to prepare a toner particle dispersion.
The toner particle dispersion is heated to 80 ° C. while stirring, and 10 parts by mass of sodium persulfate (manufactured by Mitsubishi Gas Chemical) is added as a polymerization initiator to advance the crosslinking reaction on the toner particle surface. After being held for a period of time, it was quenched with cold water to obtain a crosslinked toner particle dispersion.
The toner particle dispersion liquid after the crosslinking treatment is filtered, redispersed with ion-exchanged water, and filtered repeatedly. After washing until the electric conductivity of the filtrate becomes 20 μS / cm or less, 40 The resultant was dried in a vacuum at 5 ° C. for 5 hours to obtain toner particles after the crosslinking treatment. The average particle size of the toner particles was 7.2 μm.
After the external addition process, the same processing as in Example 1 was performed to obtain a toner, and the same evaluation was performed.
The obtained evaluation results are shown in Table 1.

[Example 4]
An amorphous polyester resin was synthesized by changing the alcohol monomer composition ratio of the amorphous polyester resin of Example 1 to 10 mol parts of bisphenol A propylene oxide 2 mol adduct and 90 mol parts of bisphenol A ethylene oxide 2 mol adduct. Further, after cooling after the crosslinking step of the toner production process of Example 1, the temperature was raised again to 50 ° C. while stirring, held for 2 hours, and then rapidly cooled. In the processes after the rapid cooling step, the same treatment as in Example 1 was performed to obtain a toner, and the same evaluation was performed.
The obtained evaluation results are shown in Table 1.

[Example 5]
A toner was obtained in the same manner as in Example 1 except that the fumaric acid used in the synthesis of the amorphous polyester resin of Example 1 was replaced with maleic acid, and the same evaluation was performed.
The obtained evaluation results are shown in Table 1.

[Example 6]
Example 3 except that the crystalline polyester resin synthesized in the same manner as the monomer constituting the crystalline polyester resin of Example 1 except that 1,9-nonanediol was replaced with 1,6-hexanediol was used. The same operation was performed to obtain a toner, and the same evaluation was performed.
The obtained evaluation results are shown in Table 1.

[Comparative Example 1]
Among the operations of Example 1, a toner was obtained by carrying out the same operations as in Example 1 except that nitrogen bubbling, initiator addition and polymerization were not carried out, and the same evaluation was carried out.
The obtained evaluation results are shown in Table 1.

[Comparative Example 2]
A toner was obtained in the same manner as in Example 1 except that the amorphous polyester resin particle dispersion liquid of Example 1 was changed to 766 parts by mass, and the crystalline polyester resin particle dispersion liquid was not used. did.
The obtained evaluation results are shown in Table 1.

[Comparative Example 3]
The same operation as in Example 1 is performed except that the ratio of the acid monomer constituting the amorphous polyester resin of Example 1 is changed to 10 mol parts of terephthalic acid, 40 mol parts of dodecenyl succinic acid, and 40 mol parts of fumaric acid. The toner was obtained in the same manner as above, and the same evaluation was performed. However, since the setback was severe and the developer aggregated during the evaluation, it was determined that the toner was not practical.
The obtained evaluation results are shown in Table 1.

[Comparative Example 4]
Of the acid monomers constituting the amorphous polyester resin of Example 1, the same operation as in Example 1 was carried out except that terephthalic acid was changed to 60 mol parts, dodecenyl succinic acid was changed to 5 mol parts, and fumaric acid was changed to 30 mol parts. Thus, a toner was obtained and the same evaluation was performed.
The obtained evaluation results are shown in Table 1.

[Comparative Example 5]
(Preparation of amorphous resin dispersion)
Add 480 parts by mass of styrene, 120 parts by mass of butyl acrylate and 6 parts by mass of carboxyethyl acrylate into a dispersion medium in which 6 parts by mass of a surfactant (sodium diphenyloxide disulfonate) is dissolved in 250 parts by mass of ion-exchanged water. The monomer emulsion was obtained by dispersing for 5 minutes at a rotation speed of 5000 rpm with a homogenizer (IKA Ultra Tarrax).
Next, 50 parts by mass of the monomer emulsion, 550 parts by mass of ion-exchanged water, and 1 part by mass of a surfactant (sodium diphenyloxide disulfonate) are charged into a vessel equipped with a stirrer that has been warmed to 80 ° C., and polymerization is started. 10 parts by mass of ammonium persulfate (Mitsubishi Gas Chemical Co., Ltd.) was added as an agent, and stirring at 200 rpm and a warm bath were maintained for 1 hour and 10 minutes.
Further, the remaining monomer emulsion is charged into a container at a rate of 3 parts by mass per minute, and after completion of the addition, stirring and a warm bath are further maintained for 5 hours, and 1M sodium hydroxide aqueous solution is added to adjust the pH to 4. As a result, an amorphous resin dispersion was obtained.
The resulting amorphous resin dispersion had a solid content concentration of 40% by mass, and the volume average particle size of the resin particles was 200 nm.
Among the operations in Example 1, a toner was obtained by using an amorphous resin dispersion instead of the amorphous polyester resin particle dispersion, and the same evaluation was performed.
The obtained evaluation results are shown in Table 1.

1Y, 1M, 1C, 1K, photoconductor (an example of an image carrier)
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 beams 4Y, 4M, 4C, 4K Developing device (an example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (an example of primary transfer means)
6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt (an example of an intermediate transfer member)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photosensitive member (an example of an image holding member)
108 Charging roll (an example of charging means)
109 Exposure apparatus (an example of electrostatic charge image forming means)
111 Developing device (an example of developing means)
112 Transfer device (an example of transfer means)
113 photoconductor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Mounting rail 117 Housing 118 Opening 200 for exposure Process cartridge 300 Recording paper (an example of a recording medium)
P Recording paper (an example of a recording medium)

Claims (7)

Containing an amorphous polyester resin and a crystalline polyester resin,
The amorphous polyester resin includes an amorphous polyester resin having an ethylenically unsaturated bond,
The surface layer portion includes a crosslinked product of the amorphous polyester resin having the ethylenically unsaturated bond,
the maximum value of tan δ is in the range of 50 ° C. or higher and 70 ° C. or lower,
The maximum value of tan δ is 1 or more,
An electrostatic charge image developing toner having an average slope with respect to the temperature of the tan δ value in a range from a temperature lower by 10 ° C. to a temperature lower by 4 ° C. than a temperature at which the maximum value of tan δ is 0.10 ° C. ⁻¹ or more. The melting temperature of the crystalline polyester resin is 70 ° C. or higher,
The toner for developing an electrostatic charge image according to claim 1, wherein the proportion of the structural unit derived from fumaric acid in the total amount of the structural unit derived from the carboxylic acid component constituting the crystalline polyester resin is 30 mol% or more.   An electrostatic charge image developer comprising the toner for developing an electrostatic charge image according to claim 1. Containing the toner for developing an electrostatic image according to claim 1;
A toner cartridge to be attached to and detached from the image forming apparatus. A developing unit that contains the electrostatic charge image developer according to claim 3 and that develops the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer.
A process cartridge attached to and detached from the image forming apparatus. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
A developing means for containing the electrostatic charge image developer according to claim 3 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
An image forming apparatus comprising: A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 3;
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image transferred to the surface of the recording medium;
An image forming method comprising: