JP2013195926A - Toner for electrostatic charge image development, developer for electrostatic charge image development, toner cartridge, developer 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 and an image forming method which form an image which is superior in strength and flexibility.SOLUTION: A toner for electrostatic charge image development which contains a binder resin, an aromatic compound having not less than 2 rings, a coloring agent, a mold lubricant and a polymerization initiator, and an image forming method including a process fixing an image formed by the toner are provided. The binder resin contains unsaturated polyester resin having ethylenic unsaturation coupling. The aromatic compound is a compound chosen from a group consisting of benzophenone compound, bisacylphosphine oxide compound, diphenyl compound, terphenyl compound and quaterphenyl compound. The polymerization initiator is an aliphatic azo-based thermal polymerization initiator or bisacylphosphine-based photopolymerization initiator.

Description

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

A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic latent image is formed on an image carrier by a charging and exposure process (latent image forming process), and a static image developing toner (hereinafter also simply referred to as “toner”) is included. The electrostatic latent image is developed with a developer for developing a charge image (hereinafter also simply referred to as “developer”) (development process), and an image is formed on a recording medium through a transfer process and a fixing process. The developer used here includes a two-component developer composed of a toner and a carrier, and a one-component developer using a magnetic toner or a nonmagnetic toner alone.
Also, the image forming method using the electrophotographic method has been widely used in the on-demand printing area from the conventional use in the office, and high-speed colorization with high image quality and high reliability is demanded. From the viewpoint of low energy fixing, a toner using a crystalline or non-crystalline polyester resin has been proposed.

As a conventionally known toner, toner for developing an electrostatic image using an unsaturated polyester resin as a polyester resin is disclosed (Patent Documents 1 to 3).
Patent Document 1 discloses a toner for developing an electrostatic charge image, which contains a crystalline polyester resin or the like, a colorant, and a terphenyl compound.
Patent Document 2 discloses an electrostatic recording apparatus that cures and fixes an emulsion aggregation toner by light. Specifically, after developing to a toner accumulation height in a specific range using a toner having an average particle size in a specific range and containing a crystalline polyester resin, an amorphous polyester resin, and a photoinitiator, the toner is irradiated with light. Is disclosed.
Patent Document 3 discloses a toner containing a polymeric or oligomeric hydroxyketone photoinitiator capable of initiating crosslinking of an unsaturated polyester resin in an emulsion aggregation toner containing an unsaturated polyester resin.

JP 2006-330278 A JP 2010-262300 A JP 2011-085935 A

In the above-described known electrostatic charge image developing toner, the present inventor generally has excellent toner image strength by crosslinking unsaturated groups of the unsaturated polyester resin, but tends to lack image flexibility. I found something.
SUMMARY An advantage of some aspects of the invention is to provide a toner for developing an electrostatic image that is excellent in both image strength and image flexibility. Another object of the present invention is to provide an image forming method that gives a toner image having excellent image strength and flexibility.

  The above problems of the present embodiment have been solved by the following means <1>, <7> to <11>, and <13>. It is listed below together with <2> to <6>, <12>, <14> and <15> which are preferred embodiments.

<1> Binder resin, containing an aromatic compound having two or more aromatic rings, a colorant, a release agent, and a polymerization initiator, wherein the binder resin contains an unsaturated polyester resin having an ethylenically unsaturated group The aromatic compound having two or more aromatic rings is a compound selected from the group consisting of a benzophenone compound, a bisacylphosphine oxide compound, a diphenyl compound, a terphenyl compound, and a quarterphenyl compound; An electrostatic charge image developing toner, characterized in that the agent is an aliphatic azo thermal polymerization initiator or a bisacylphosphine oxide photopolymerization initiator,
<2> The electrostatic image developing toner according to <1>, which contains a bisacylphosphine oxide compound as the aromatic compound,
<3> The electrostatic image developing toner according to <1> or <2>, comprising a compound selected from the group consisting of a diphenyl compound, a terphenyl compound, and a quaterphenyl compound as the aromatic compound,
<4> The electrostatic image developing toner according to any one of <1> to <3>, which contains m-terphenyl as the aromatic compound.
<5> The electrostatic image developing toner according to any one of <1> to <4>, wherein the unsaturated polyester resin is an amorphous polyester resin and / or a crystalline polyester resin.
<6> The toner for developing an electrostatic charge image according to any one of <1> to <5>, wherein the content of the unsaturated polyester resin in the binder resin is 50 to 80% by weight,
<7> An electrostatic charge image developing developer comprising the electrostatic charge image developing toner according to any one of <1> to <6>,
<8> A toner cartridge comprising the electrostatic image developing toner according to any one of <1> to <6>,
<9> A developer cartridge comprising the developer for developing an electrostatic image according to <7>,
<10> an image carrier, and a developing unit that develops the electrostatic latent image formed on the surface of the image carrier using a developer to form a toner image, and the developer includes <8 A process cartridge, wherein the developer is an electrostatic charge image developing developer
<11> An image carrier, a charging unit that charges the surface of the image carrier, a latent image forming unit that forms an electrostatic latent image on the surface of the image carrier, and a surface of the image carrier. A developing unit that develops the electrostatic latent image using a developer to form a toner image, a transfer unit that transfers the developed toner image to a transfer target, and a fixing that fixes the transferred toner image An image forming apparatus, wherein the developer is the developer for developing an electrostatic charge image according to <7>.
<12> The image forming apparatus according to <11>, further comprising an ultraviolet irradiation unit that irradiates the transferred toner image with ultraviolet rays.
<13> A charging step for charging the surface of the image carrier, a latent image forming step for forming an electrostatic latent image on the surface of the image carrier, and an electrostatic latent image formed on the surface of the image carrier. A development step of developing with a developer to form a toner image; a transfer step of transferring the developed toner image to a transfer target; and a fixing step of fixing the transferred toner image; The image forming method, wherein the developer is the developer for developing an electrostatic charge image according to <7>,
<14> The image forming method according to <13>, further comprising an ultraviolet irradiation step of irradiating the transferred toner image with ultraviolet rays.
<15> The image forming method according to <14>, wherein a fixing step of heating and fixing the transferred toner image and an ultraviolet irradiation step are simultaneously performed.

According to the invention described in <1>, an electrostatic charge image developing toner excellent in strength and flexibility of an image obtained is provided as compared with the case where the present configuration is not provided.
According to the invention described in <2> above, the toner for developing an electrostatic charge image, which is superior in strength and flexibility of the obtained image as compared with the case where the aromatic compound is other than a bisacylphosphine oxide compound. Is provided.
According to the invention described in <3> above, a toner for developing an electrostatic image that is superior in strength and flexibility of an obtained image is provided as compared with the case of using another aromatic compound.
According to the invention described in <4> above, there is provided an electrostatic image developing toner that is particularly excellent in the strength and flexibility of the resulting image as compared to cases other than m-terphenyl.
According to the invention described in <5> above, there is provided an electrostatic charge image developing toner that is excellent in strength and flexibility of an image obtained and can be fixed at a low temperature as compared with the case without this configuration. Provided.
According to the invention described in <6> above, an electrostatic charge image developing toner excellent in strength and flexibility of an obtained image is provided as compared with the case where the present configuration is not provided.
According to the invention described in <7> above, development for developing an electrostatic charge image that is superior in strength and flexibility of an image obtained as compared with a case where the amount of the unsaturated polyester resin is out of this numerical range. An agent is provided.
According to the invention described in <8> above, a toner cartridge excellent in strength and flexibility of an image to be obtained is provided as compared with the case where the present configuration is not provided.
According to the invention described in <9> above, a developer cartridge excellent in strength and flexibility of an image obtained is provided as compared with the case where the present configuration is not provided.
According to the invention described in <10> above, a process cartridge excellent in strength and flexibility of an image to be obtained is provided as compared with the case where the present configuration is not provided.
According to the invention described in <11> above, an image forming apparatus excellent in strength and flexibility of an image to be obtained is provided as compared with the case where the present configuration is not provided.
According to the invention described in <12> above, an image forming apparatus that is superior in strength and flexibility of an image to be obtained can be provided as compared with a case where no ultraviolet irradiation unit is provided.
According to the invention described in <13> above, an image forming method excellent in strength and flexibility of an obtained image is provided as compared with the case where the present configuration is not provided.
According to the invention described in <14> above, an image forming method superior in strength and flexibility of an image obtained is provided as compared with a case where an ultraviolet irradiation step is not provided.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. It is a schematic structure figure showing an example of a process cartridge concerning an embodiment of the present invention. It is a conceptual diagram which shows an example of the fixing device which performs heat fixing and ultraviolet irradiation simultaneously.

Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.
In the present specification, the description of “lower limit to upper limit” representing a numerical range represents “lower limit or higher and lower limit or lower”, and the description of “upper limit to lower limit” represents “lower limit or higher and lower limit or higher”. That is, it represents a numerical range including an upper limit and a lower limit.

1. Toner for developing electrostatic charge The toner for developing an electrostatic image of this embodiment comprises a binder resin, an aromatic compound having two or more aromatic rings, a colorant, a release agent, and a polymerization initiator, and the binder resin. Contains an unsaturated polyester resin having an ethylenically unsaturated group, and the aromatic compound is selected from the group consisting of a benzophenone compound, a bisacylphosphine oxide compound, a diphenyl compound, a terphenyl compound, and a quarterphenyl compound. The polymerization initiator is an aliphatic azo thermal polymerization initiator or a bisacylphosphine oxide photopolymerization initiator.
Hereinafter, the above embodiment will be described in detail.

<Binder resin>
(Unsaturated polyester resin)
The toner for developing an electrostatic charge image (hereinafter also simply referred to as “toner”) of the present embodiment is an unsaturated polyester resin having an ethylenically unsaturated group (hereinafter simply referred to as “unsaturated polyester resin”) as a binder resin. Contain).
The unsaturated polyester resin is synthesized by polycondensation from a polyol (also referred to as “polyhydric alcohol” in this embodiment) component and a polycarboxylic acid (“polycarboxylic acid” in this embodiment) component. There is no particular limitation as to which monomer unit the ethylenically unsaturated group that the unsaturated polyester resin has, but from the viewpoint of cost and reactivity, the residue derived from the polycarboxylic acid is an ethylenically unsaturated group. It is preferable to contain.
In addition, a commercial item may be used as said unsaturated polyester resin, and what was synthesize | combined suitably may be used.
The unsaturated polyester resin is a non-crystalline polyester resin and / or a non-crystalline polyester resin, as long as it is contained in at least one of the crystalline polyester resin or the non-crystalline resin. Is preferred.

  As the polycarboxylic acid used for polycondensation of the unsaturated polyester resin, an aliphatic unsaturated polycarboxylic acid is preferably used. Such an unsaturated polycarboxylic acid includes maleic acid, fumaric acid, Examples include itaconic acid, citraconic acid, 3-hexenedioic acid, 3-octenedioic acid, dodecenyl succinic acid, their lower esters, acid anhydrides and the like. Among them, the aliphatic unsaturated polycarboxylic acid preferably includes an aliphatic polycarboxylic acid having 4 or 5 carbon atoms having an ethylenically unsaturated group, and maleic acid, fumaric acid, or maleic anhydride is preferable. Particularly preferred is mentioned.

Examples of other polyvalent carboxylic acid components include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1 , 12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, aliphatic dicarboxylic acid such as 1,18-octadecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, And aromatic dicarboxylic acids such as dibasic acids such as mesaconic acid. Furthermore, these anhydrides and these lower alkyl esters are also exemplified, but not limited thereto.
Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, anhydrides thereof, and the like. And lower alkyl esters. Here, “lower alkyl swell” means swell with alcohol having 1 to 5 carbon atoms.
These may be used individually by 1 type and may use 2 or more types together.

As the polyhydric alcohol component, divalent polyhydric alcohol is preferably used, and polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2. , 2-bis (4-hydroxyphenyl) propane and other bisphenol A alkylene (2 to 4 carbon) oxide adducts (average addition mole number 1.5 to 6), ethylene glycol, propylene glycol, neopentyl glycol, 1 1, 4-butanediol, 1,3-butanediol, 1,6-hexanediol.
Examples of the trihydric or higher polyhydric alcohol include sorbitol, pentaerythritol, glycerol, trimethylolpropane and the like.

(Crystalline polyester resin)
In this embodiment, an amorphous polyester resin may be used alone as the polyester resin, and it is also preferable to use the crystalline polyester resin in combination with the amorphous polyester resin.
Further, by using a crystalline polyester resin as a part of the binder resin, low temperature fixability can be imparted to the toner.
In the present embodiment, it is preferable to use an amorphous polyester resin having an ethylenically unsaturated group and a crystalline polyester resin as the binder resin. In this case, it is preferable that the compounding quantity with respect to the amorphous polyester resin of a crystalline polyester resin is 2-20 weight with respect to the whole quantity of an amorphous polyester resin.
Hereinafter, the crystalline polyester resin and the amorphous polyester resin will be described in detail.

“Crystalline polyester resin” refers to a resin having a clear endothermic peak in differential scanning calorimetry (DSC). That is, in differential scanning calorimetry (DSC), it indicates that it has a clear endothermic peak. Specifically, the half-value width of the endothermic peak when measured at a heating rate of 10 ° C./min is within 6 ° C. Means. On the other hand, a resin in which the half-value width of the endothermic peak exceeds 6 ° C. or a resin in which no clear endothermic peak is observed is regarded as non-crystalline. When the crystalline resin shows a plurality of melting peaks, the maximum peak is regarded as the melting point.
Moreover, the glass transition temperature of an amorphous resin means the value measured by the method (DSC method) prescribed | regulated to ASTMD3418-82.

The endothermic peak temperature of the crystalline polyester resin is preferably 50 to 120 ° C, and more preferably 55 to 100 ° C. When the endothermic peak temperature is 50 ° C. or higher, the cohesive force of the binder resin itself is good even in a high temperature range, the peelability during fixing is excellent, and hot offset can be suppressed. Further, when the endothermic peak temperature is 120 ° C. or lower, sufficient melting can be obtained and the minimum fixing temperature can be lowered.
The glass transition temperature Tg of the amorphous polyester resin is preferably 40 to 80 ° C, and more preferably 50 to 65 ° C. When Tg is 40 ° C. or higher, the cohesive force of the binder resin itself is maintained even in a high temperature range, and hot offset can be suppressed during fixing. Further, when Tg is 80 ° C. or lower, sufficient melting can be obtained, and the minimum fixing temperature can be lowered.

  The crystalline polyester resin is preferably composed of an aliphatic dicarboxylic acid and an aliphatic diol, and more preferably a linear dicarboxylic acid or a linear aliphatic diol having 4 to 20 carbon atoms in the main chain portion. The linear type is excellent in the crystallinity of the polyester resin and has an appropriate crystal melting point, and thus is excellent in toner blocking resistance, image storage stability, and low-temperature fixability. Further, when the carbon number is 4 or more, the ester bond concentration is low, the electric resistance is moderate, and the toner charging property is excellent. Further, when it is 20 or less, it is easy to obtain practical materials. The carbon number is more preferably 14 or less.

Examples of the aliphatic dicarboxylic acid suitably used for the synthesis of the crystalline polyester include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelinic acid, sebacic acid, 1,9-nonane. Dicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid An acid, 1,18-octadecanedicarboxylic acid or the like, or a lower alkyl ester or an acid anhydride thereof may be mentioned, but not limited thereto. Among these, considering availability, sebacic acid and 1,10-decanedicarboxylic acid are preferable.
Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol 1,18-octadecanediol, 1,14-eicosandecanediol and the like, but are not limited thereto. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.
Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

Among the polyvalent carboxylic acid components, the content of the aliphatic dicarboxylic acid is preferably 80 mol% or more, and more preferably 90 mol% or more. When the content of the aliphatic dicarboxylic acid is 80 mol% or more, the polyester resin is excellent in crystallinity and has an appropriate melting point, and therefore toner blocking resistance and image storage stability. And it is excellent in low-temperature fixability.
Among the polyhydric alcohol components, the content of the aliphatic diol component is preferably 80 mol% or more, and more preferably 90 mol% or more. When the content of the aliphatic diol component is 80 mol% or more, the polyester resin is excellent in crystallinity and has an appropriate melting point, and therefore excellent in toner blocking resistance, image storage stability, and low-temperature fixability.

(Non-crystalline polyester resin)
In an amorphous polyester resin (also referred to as “amorphous polyester resin”), a dihydric or higher secondary alcohol and / or a divalent or higher aromatic carboxylic acid compound is preferable as a raw material monomer. Examples of the dihydric or higher secondary alcohol include a propylene oxide adduct of bisphenol A, propylene glycol, 1,3-butanediol, and glycerol. In these, the propylene oxide adduct of bisphenol A is preferable.
As the divalent or higher aromatic carboxylic acid compound, terephthalic acid, isophthalic acid, phthalic acid and trimellitic acid are preferable, and terephthalic acid and trimellitic acid are more preferable.

There are no particular limitations on the method for producing the polyester resin, regardless of crystallinity and non-crystallinity, and the polyester resin can be produced by a general polyester polymerization method in which a polyol component and a polycarboxylic acid component are reacted. Examples include polycondensation, transesterification, and the like. Further, it is preferable to use a polycondensation catalyst such as a metal catalyst or a Bronsted acid catalyst.
When the polyester resin directly polycondenses the polyol and the polycarboxylic acid, for example, the polyol and the polycarboxylic acid, a catalyst as necessary, a reaction vessel equipped with a thermometer, a stirrer, and a flow-down condenser When heated at 150 ° C. to 250 ° C. in the presence of an inert gas (nitrogen gas, etc.), continuously removes by-product low-molecular compounds out of the reaction system, and reaches a predetermined acid value The reaction is stopped by cooling, cooled, and the desired reactant is obtained.

The hydroxyl value of the binder resin in the toner of the exemplary embodiment is preferably 0 to 10 mgKOH / g, more preferably 0 to 8 mgKOH / g, and still more preferably 0 to 5 mgKOH / g. Within the above range, the chargeability is more excellent.
The acid value of the binder resin in the toner of the exemplary embodiment is preferably 2 to 20 mgKOH / g, more preferably 2 to 15 mgKOH / g, and further preferably 5 to 12 mgKOH / g. Within the above range, the toner is excellent in granulation properties and more excellent in charge amount environment dependency.
In addition, the measurement of the acid value and hydroxyl value in this embodiment is performed with the following method.
As the acid value and the hydroxyl value, values measured according to a method (potentiometric titration method) defined in JIS K0070-1992 are adopted. However, if the sample does not dissolve, a solvent such as dioxane or tetrahydrofuran is used as the solvent.

  Moreover, it is preferable that the weight average molecular weights of the polyester resin used for this embodiment are 4,000-100,000, and it is more preferable that it is 6,000-80,000. When the weight average molecular weight is 4,000 or more, a good cohesive force can be obtained as a binder resin, and the hot offset property is excellent. Further, when the weight average molecular weight is 100,000 or less, good hot offset property and a suitable minimum fixing temperature can be obtained.

  In addition to polyester resins, binder resins include copolymers of styrene and acrylic acid or methacrylic acid, polyvinyl chloride resins, phenol resins, acrylic resins, methacrylic resins, polyvinyl acetate, silicone resins, polyurethane resins, polyamides Resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumarone indene resins, petroleum resins, polyether polyol resins, and the like may be used in combination as necessary.

  Further, the content of the binder resin in the toner in the toner of the present embodiment is not particularly limited, but is preferably 30 to 99% by weight, and preferably 40 to 98% by weight with respect to the total weight of the toner particles. It is more preferable that it is 50 to 96% by weight. Within the above range, the fixing property, storage property, powder property, charging property and the like are excellent.

<Aromatic compound having two or more aromatic rings>
The toner according to the exemplary embodiment includes at least one aromatic compound having two or more aromatic rings. Specifically, the aromatic compound includes a benzophenone compound, a bisacylphosphine oxide compound, a diphenyl compound, and a terphenyl. Selected from the group consisting of compounds and quaterphenyl compounds.
These compound groups will be described in the following order.

(Benzophenone compound)
Benzophenone compounds include benzophenone and its derivatives. That is, unsubstituted benzophenone and derivatives having at least one substituent on the phenyl group of benzophenone are included. Here, the permissible substituent is preferably an inert substituent, and examples thereof include a halogen atom, a hydroxyl group, an amino group, and a substituted amino group (including mono- or di-lower alkyl substituents).
The benzophenone compound preferably does not have a peroxy group. Moreover, it is preferable that it does not have chemical reactivity like benzophenone tetracarboxylic acid anhydride.
As the benzophenone compound, unsubstituted benzophenone is preferable.
In addition to functioning as a plasticizer in the toner, this compound functions as a sensitizer for generating photo radicals, and is used in combination with a photopolymerization initiator to contribute to addition polymerization of ethylenically unsaturated bonds in unsaturated polyesters. To do.

(Bisacylphosphine oxide compound)
The bisacylphosphine oxide compound is preferably represented by the following formula (1).
In addition to functioning as a plasticizer in the toner, this compound is a photo radical generator that initiates addition polymerization of ethylenically unsaturated bonds in unsaturated polyesters.

  There is no restriction | limiting in particular as a bisacyl phosphine oxide compound, Although a well-known thing can be used, It is preferable that it is a compound represented by following formula (1).

（式（１）中、Ｒ^1E、Ｒ^2E及びＲ^3Eはそれぞれ独立に、メチル基又はエチル基を置換基として有していてもよい芳香族炭化水素基を表す。）

(In formula (1), R ^1E , R ^2E and R ^3E each independently represents an aromatic hydrocarbon group optionally having a methyl group or an ethyl group as a substituent.)

A known bisacylphosphine oxide compound can be used as the bisacylphosphine oxide compound. Examples thereof include bisacylphosphine oxide compounds described in JP-A-3-101686, JP-A-5-345790, and JP-A-6-298818.
Specific examples include bis (2,6-dichlorobenzoyl) phenylphosphine oxide, bis (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis (2,6-dichlorobenzoyl) -4-ethoxy. Phenylphosphine oxide, bis (2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis (2,6-dichlorobenzoyl) -2-naphthylphosphine oxide, bis (2,6-dichlorobenzoyl) -1-naphthyl Phosphine oxide, bis (2,6-dichlorobenzoyl) -4-chlorophenylphosphine oxide, bis (2,6-dichlorobenzoyl) -2,4-dimethoxyphenylphosphine oxide, bis (2,6-dichlorobenzoyl) decylphosphite Oxide, bis (2,6-dichlorobenzoyl) -4-octylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,5- Dimethylphenylphosphine oxide, bis (2,6-dichloro3,4,5-trimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis (2,6-dichloro-3,4,5-trimethoxybenzoyl) -4-ethoxyphenylphosphine oxide, bis (2-methyl-1-naphthoyl) -2,5-dimethylphenylphosphine oxide, bis (2-methyl-1-naphthoyl) -4-ethoxyphenylphosphine oxide, bis (2- Methyl-1-naphthoyl) -2-naphthy Phosphine oxide, bis (2-methyl-1-naphthoyl) -4-propylphenylphosphine oxide, bis (2-methyl-1-naphthoyl) -2,5-dimethylphenylphosphine oxide, bis (2-methoxy-1-naphthoyl) ) -4-Ethoxyphenylphosphine oxide, bis (2-chloro-1-naphthoyl) -2,5-dimethylphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, etc. Is mentioned.

  Among these, as the bisacylphosphine oxide compound, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (LUCIRIN TPO, manufactured by BASF), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (IRGACURE 819: Ciba Specialty Chemicals), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphenylphosphine oxide, and the like are preferable.

(Diphenyl compound)
A diphenyl compound is synonymous with a biphenyl compound.
The diphenyl compound is a compound in which two phenyl groups are directly bonded, and includes a compound substituted with one or more substituents. Here, the permissible substituent is preferably a chemically inert substituent, and examples thereof include a halogen atom, a hydroxyl group, an amino group, and a substituted amino group (including mono- or di-lower alkyl substituents).
As the diphenyl compound, unsubstituted diphenyl (biphenyl) is preferable.
The diphenyl compound preferably does not have a peroxy group.

(Terphenyl compound)
A terphenyl compound is a compound in which three phenyl groups are directly bonded, and includes a compound substituted with one or more substituents. Here, the permissible substituent is preferably a chemically inert substituent, and examples thereof include a halogen atom, a hydroxyl group, an amino group, and a substituted amino group (including mono- or di-lower alkyl substituents).
As the terphenyl compound, unsubstituted terphenyl is preferable, m-terphenyl and o-terphenyl are preferable, and m-terphenyl is particularly preferable. Any compound can be obtained as a commercial product.

  The o-terphenyl preferably used below is preferred, and m-terphenyl is shown as general formula (1) and general formula (2).

ただし、一般式（１）及び一般式（２）中、Ｒ¹、Ｒ²、Ｒ³は、水素原子、塩素原子、臭素原子、又は、メチル基を意味する。
ターフェニル化合物の詳細な説明は、特開２００６−３３０２７８号公報に一般式（１）及び（２）として記載されている。

However, in general formula (1) and general formula (2), R < ¹ >, R < ² >, R < ³ > means a hydrogen atom, a chlorine atom, a bromine atom, or a methyl group.
A detailed description of the terphenyl compound is described in JP-A-2006-330278 as general formulas (1) and (2).

(Quarterphenyl compound)
Quarterphenyl is synonymous with quaterphenyl and is a compound in which four phenyl groups are bonded directly in a linear form. Although there are various structural isomers in the quarterphenyl compound, p-quarterphenyl is preferred, and it is represented by the following formula (3). This compound is available as a commercial product.

  The total content of the aromatic compound in the electrostatic image developing toner is preferably 1 to 20% by weight, and more preferably 2 to 10% by weight, based on the total weight of the toner.

In this embodiment, the aspect which uses together a terphenyl compound and either a thermal-polymerization initiator or a photoinitiator is preferable. The thermal polymerization initiator used in combination is preferably an azo thermal polymerization initiator, and the photopolymerization initiator is preferably the bisacylphosphine oxide photopolymerization initiator described above.
In addition, the combined use of the aforementioned bisacylphosphine oxide photopolymerization initiator and azo thermal polymerization initiator is also a preferred embodiment.

<Polymerization initiator>
In this embodiment, the toner contains a polymerization initiator. The polymerization initiator has a function of addition polymerization of an ethylenically unsaturated group of the unsaturated polyester, and is roughly classified into a thermal polymerization initiator and a photopolymerization initiator. In this embodiment, it is an aliphatic azo thermal polymerization initiator or a bisacylphosphine oxide photopolymerization initiator.
As described above, when a bisacylphosphine oxide compound is used as an aromatic compound having two or more aromatic rings, this compound also serves as a photopolymerization initiator.
(Thermal polymerization initiator)
In this embodiment, the electrostatic image developing toner contains a thermal polymerization initiator or a photopolymerization initiator. As the thermal polymerization initiator, a thermal radical polymerization initiator is used, and an aliphatic azo thermal polymerization initiator is used. However, this does not prevent the combined use of other thermal polymerization initiators.
Other thermal radical polymerization initiators are preferably exemplified by organic peroxides.

(Aliphatic azo thermal polymerization initiator)
The aliphatic azo thermal polymerization initiator is a compound that does not contain an aromatic group and contains an azo group, and a known compound is used as the thermal polymerization initiator. Specific examples thereof include 2,2′-azobisisobutyronitrile, 2,2′-azobispropionitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis. (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 4,4′- Azobis (4-cyanovaleric acid), dimethyl 2,2′-azobisisobutyrate, 2,2′-azobis (2-methylpropionamidooxime), 2,2′-azobis [2- (2-imidazolin-2-yl) ) Propane], 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2'-azobis [2-methyl-N- (2-hydroxy Ethyl) propionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis (N-cyclohexyl-2-methylpropionamide), 2,2′-azobis [N -(2-propenyl) -2-methylpropionamide], 2,2′-azobis (2,4,4-trimethylpentane).

The thermal polymerization initiator in this embodiment may be used individually by 1 type, and can also use 2 or more types together.
The content of the thermal polymerization initiator in the electrostatic image developing toner is preferably from 0.01 to 10% by weight, more preferably from 0.1 to 3% by weight, based on the total weight of the toner.

  The radical polymerization initiator that can be used in combination with the present embodiment is preferably an organic peroxide. Specific examples of the organic peroxide include 3,3′4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra (t-amylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra (t-hexylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra (t-octylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra Peroxide esters such as (cumylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra (p-isopropylcumylperoxycarbonyl) benzophenone, di-t-butyldiperoxyisophthalate are included.

(Bisacylphosphine oxide photopolymerization initiator)
Since it is the same as the content described as the aromatic compound having two or more aromatic rings, overlapping is omitted.
It is preferable that the aromatic compound having two or more aromatic rings and the polymerization initiator are dissolved in an organic solvent together with the binder resin, and water is dropped into this solution to perform phase inversion emulsification.

<Colorant>
The toner base particles contain a colorant.
Examples of the colorant used in the toner of the exemplary embodiment include magnetic powders such as magnetite and ferrite, carbon black, lamp black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, permanent orange GTR, and pyrazolone orange. , Vulcan Orange, Watch Young Red, Permanent Red, Brilliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Rizor Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue , Ultramarine blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxalate, etc. Or acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, Various dyes such as triphenylmethane, diphenylmethane, thiazine, thiazole, and xanthene can be used singly or in combination of two or more.
In addition, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. And CI Pigment Blue 15: 3.

  The content of the colorant in the toner base particles is preferably in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the binder resin in the toner base particles. It is also effective to use a surface-treated colorant or a pigment dispersant as necessary. By appropriately selecting the type of the colorant, it is possible to obtain toners having various colors such as yellow toner, magenta toner, cyan toner, and black toner.

<Release agent>
The toner base particles contain a release agent.
There is no restriction | limiting in particular in the mold release agent used for this embodiment, A well-known thing is used and the following waxes are preferable.
Examples thereof include paraffin wax and derivatives thereof, montan wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, and polyolefin wax and derivatives thereof. Derivatives include oxides, polymers with vinyl monomers, and graft modified products. In addition, alcohols, fatty acids, plant waxes, animal waxes, mineral waxes, ester waxes, acid amides and the like are also used.

The wax used as a release agent is preferably melted at any temperature of 70 to 140 ° C. and exhibits a melt viscosity of 1 to 200 centipoise, more preferably 1 to 100 centipoise. When the melting temperature is 70 ° C. or higher, the change temperature of the wax is sufficiently high, and the blocking resistance and the developability are excellent when the temperature in the copying machine is increased. When the temperature is 140 ° C. or lower, the change temperature of the wax is sufficiently low, it is not necessary to perform fixing at a high temperature, and energy saving is excellent. Further, when the melt viscosity is 200 centipoises or less, the elution from the toner is appropriate and the fixing peelability is excellent.
In the toner of the present exemplary embodiment, the release agent is selected from the viewpoints of fixing properties, toner blocking properties, toner strength, and the like. The amount of the release agent added is not particularly limited, but is preferably in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the binder resin contained in the toner base particles.

<Other additives>
In addition to the above-described components, various components such as an internal additive and a charge control agent may be added to the colored particles as necessary.
Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel and manganese, alloys, and magnetic materials such as compounds containing these metals.
Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments.

In the toner used in the exemplary embodiment, an external additive is appropriately used in combination with the toner base particles. The method for producing the toner base particles is not particularly limited, and a known method can be used. Specific examples include the following methods.
The production of the toner mother particles is, for example, kneading a binder resin, an aromatic compound having two or more aromatic rings, a colorant, a release agent, a polymerization initiator, and a charge control agent if necessary. A kneading and pulverizing method for pulverizing and classifying; a method for changing the shape of particles obtained by the kneading and pulverizing method by mechanical impact force or thermal energy; a dispersion obtained by emulsifying and dispersing a binder resin, and two or more aromas An emulsion aggregation method for obtaining toner particles by mixing a ring-containing aromatic compound, a colorant, a release agent, and, if necessary, a dispersion such as a charge control agent, and agglomerating and heat-fusing; a binder resin; A dispersion formed by emulsion polymerization of the polymerizable monomer, and a dispersion of an aromatic compound having two or more aromatic rings, a colorant, a release agent, and, if necessary, a charge control agent Are mixed, agglomerated and heat-fused to obtain toner particles; an emulsion polymerization aggregation method; Polymerization is carried out by suspending a polymerizable monomer for the reaction and a solution of an aromatic compound having two or more aromatic rings, a colorant, a release agent, and, if necessary, a charge control agent in an aqueous solvent. Suspension polymerization method: a suspension method in which a binder resin, a colorant, a release agent, and, if necessary, a solution such as a charge control agent are suspended in an aqueous solvent and granulated can be used. . In addition, a manufacturing method may be performed in which the toner base particles obtained by the above method are used as a core, and aggregated particles are further adhered and heat-fused to have a core-shell structure.
Among these, the toner of the exemplary embodiment is preferably a toner (emulsion aggregation toner) obtained by an emulsion aggregation method or an emulsion polymerization aggregation method.
Furthermore, a method of encapsulating a polymerization initiator in a resin during phase inversion emulsification is preferable. Specifically, emulsion particles containing a polymerization initiator can be obtained by adding a resin and a polymerization initiator into a solvent and then adding water dropwise.

  The toner base particles produced as described above preferably have a volume average particle diameter in the range of 2 to 8 μm, and more preferably in the range of 3 to 7 μm. When the volume average particle size is 2 μm or more, the fluidity of the toner is good and sufficient charging ability is imparted from the carrier, so that fogging in the background portion and density reproducibility are unlikely to occur. . Further, when the volume average particle size is 8 μm or less, the effect of improving the reproducibility, gradation and graininess of fine dots is good, and a high-quality image can be obtained. The volume average particle diameter is measured with a measuring machine such as Coulter Multisizer II (manufactured by Beckman Coulter, Inc.).

  The toner base particles are preferably pseudo-spherical from the viewpoint of improving developability and transfer efficiency and improving image quality. The sphericity of the toner base particles can be expressed by using the shape factor SF1 of the following formula, but the average value (average shape factor) of the shape factor SF1 of the toner base particles used in this embodiment is 145. Is preferably in the range of 115 or more and less than 140, more preferably in the range of 120 or more and less than 140. When the average value of the shape factor SF1 is less than 145, good transfer efficiency is obtained and the image quality is excellent.

In the above formula, ML represents the maximum length of each toner base particle, and A represents the projected area of each toner base particle.
The average value of the shape factor SF1 (average shape factor) is obtained by taking 1,000 toner images magnified 250 times from an optical microscope to an image analyzer (LUZEX III, manufactured by Nireco Corporation), and the maximum From the length and the projected area, the value of the SF1 is obtained for each particle and averaged.

2. The developer for developing an electrostatic charge image The toner for developing an electrostatic charge image of the present embodiment is suitably used as a developer for developing an electrostatic charge image.
The developer for developing an electrostatic charge image of this embodiment is not particularly limited except that it contains the toner for developing an electrostatic charge image of this embodiment, and can take an appropriate component composition according to the purpose. When the electrostatic image developing toner of this embodiment is used alone, it is prepared as a one-component electrostatic image developing developer, and when used in combination with a carrier, a two-component electrostatic image developing developer is used. As prepared.
As a one-component developer, a method in which a charged toner is formed by frictional charging with a developing sleeve or a charging member, and development is performed according to an electrostatic latent image is also applied.

  In the present embodiment, the development method is not particularly defined, but the two-component development method is preferable. Further, the carrier is not particularly defined as long as the above conditions are satisfied. Examples of the carrier core material include magnetic metals such as iron, steel, nickel, and cobalt, alloys of these with manganese, chromium, rare earth, and the like, and Magnetic oxides such as ferrite and magnetite are mentioned, and from the viewpoint of core material surface properties and core material resistance, ferrite, particularly alloys with manganese, lithium, strontium, magnesium and the like are preferably mentioned.

The carrier used in this embodiment is preferably formed by coating the surface of the core material with a resin. There is no restriction | limiting in particular as said resin, According to the objective, it selects suitably. For example, polyolefin resins such as polyethylene and polypropylene; polyvinyl resins and polyvinylidene resins such as polystyrene, acrylic resins, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone Vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; straight silicone resin composed of organosiloxane bond or modified product thereof; polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, etc. Fluorine resin; Silicone resin; Polyester; Polyurethane; Polycarbonate; Phenol resin; Urea-formaldehyde resin, Melamine tree , Benzoguanamine resins, urea resins, amino resins such as polyamide resins, epoxy resins, per se known resins and the like. These may be used individually by 1 type and may use 2 or more types together. In the present embodiment, among these resins, it is preferable to use at least a fluorine resin and / or a silicone resin. The use of at least a fluorine-based resin and / or a silicone resin as the resin is advantageous in that the effect of preventing carrier contamination (impaction) due to toner and external additives is high.
In the resin coating, it is preferable that resin particles and / or conductive particles are dispersed in the resin. Examples of the resin particles include thermoplastic resin particles and thermosetting resin particles. Among these, thermosetting resins are preferable from the viewpoint of relatively easily increasing the hardness, and resin particles made of nitrogen-containing resin containing N atoms are preferable from the viewpoint of imparting negative chargeability to the toner. In addition, these resin particles may be used individually by 1 type, and may use 2 or more types together. The average particle size of the resin particles is preferably 0.1 to 2 μm, and more preferably 0.2 to 1 μm. When the average particle size of the resin particles is 0.1 μm or more, the resin particles are excellent in dispersibility in the coating, whereas when the average particle size is 2 μm or less, the resin particles are not easily dropped from the coating.

  Examples of the conductive particles include metal particles such as gold, silver, and copper, carbon black particles, and surfaces of titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate powder, tin oxide, carbon black, metal And particles covered with the like. These may be used individually by 1 type and may use 2 or more types together. Among these, carbon black particles are preferable in terms of good production stability, cost, conductivity and the like. The type of carbon black is not particularly limited, but carbon black having a DBP oil absorption of 50 to 250 ml / 100 g is preferable because of excellent production stability. The coating amount of the resin, the resin particles, and the conductive particles on the surface of the core material is preferably 0.5 to 5.0% by weight, and preferably 0.7 to 3.0% by weight. More preferred.

The method for forming the coating is not particularly limited. For example, the resin particles such as crosslinkable resin particles and / or the conductive particles, and a styrene acrylic resin, a fluorine resin, a silicone resin as a matrix resin, etc. And a method of using a film-forming solution containing the above resin in a solvent.
Specifically, the carrier core material is immersed in the film forming liquid, a spray method in which the film forming liquid is sprayed on the surface of the carrier core material, and the carrier core material is floated by flowing air And kneader coater method in which the film forming solution is mixed and the solvent is removed. Among these, the kneader coater method is preferable in the present embodiment.

  The solvent used for the film-forming liquid is not particularly limited as long as it can dissolve only the resin as a matrix resin, and is selected from known solvents such as toluene, Aromatic hydrocarbons such as xylene, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, and the like. When the resin particles are dispersed in the coating, since the resin particles and the particles as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface, the carrier is used for a long time. Even when the coating is worn, it is possible to always maintain the same surface formation as when it is not used, and to maintain a good charge imparting ability for the toner over a long period of time. In the case where the conductive particles are dispersed in the coating, the conductive particles and the resin as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface. Even if the coating is worn out over a long period of time, the same surface formation as when not in use can be maintained, and carrier deterioration is prevented for a long period of time. In addition, when the said resin particle and the said electroconductive particle are disperse | distributed to the said film, the above-mentioned effect is exhibited simultaneously.

The electric resistance of the magnetic carrier formed as described above in the state of a magnetic brush under an electric field of 10 ⁴ V / cm is preferably 10 ⁸ to 10 ¹³ Ωcm. When the electric resistance of the magnetic carrier is 10 ⁸ Ωcm or more, the adhesion of the carrier to the image portion on the image carrier is suppressed, and the brush mark is difficult to appear. On the other hand, when the electrical resistance of the magnetic carrier is 10 ¹³ Ωcm or less, the generation of the edge effect is suppressed and a good image quality is obtained.
The electrical resistance (volume specific resistance) is measured as follows.
A measuring jig comprising a pair of 20 cm ² circular electrode plates (made of steel) connected to an electrometer (manufactured by KEITHLEY, trade name: KEITHLEY 610C) and a high-voltage power supply (trade name: FLUKE 415B). The sample is placed on the lower electrode plate so as to form a flat layer having a thickness of about 1 mm to 3 mm. Next, after the upper electrode plate is placed on the sample, a weight of 4 kg is placed on the upper electrode plate in order to eliminate the gap between the samples. In this state, the thickness of the sample layer is measured. Next, the current value is measured by applying a voltage to the bipolar plate, and the volume resistivity is calculated based on the following equation.
Volume resistivity = applied voltage × 20 ÷ (current value−initial current value) ÷ sample thickness In the above formula, the initial current is the current value when the applied voltage is 0, and the current value indicates the measured current value.

  In the two-component electrostatic charge image developer, the mixing ratio of the toner and the carrier of this embodiment is preferably 2 to 10 parts by weight of the toner with respect to 100 parts by weight of the carrier. Moreover, the preparation method of a developing agent is not specifically limited, For example, the method of mixing with a V blender etc. is mentioned.

3. Image Forming Apparatus and Image Forming Method Next, an image forming apparatus and an image forming method according to this embodiment using the electrostatic image developing toner according to this embodiment will be described.
The image forming apparatus according to the present embodiment includes an image carrier (photosensitive member), a charging unit that charges the surface of the image carrier, and a latent image forming unit that forms an electrostatic latent image on the surface of the image carrier. And developing means for developing the electrostatic latent image formed on the surface of the image carrier using a developer to form a toner image, and transfer means for transferring the developed toner image to the transfer target. And a fixing means for fixing the transferred toner image, wherein the developer is the developer for developing an electrostatic charge image of the present embodiment.
The image forming method according to the present embodiment includes a charging step for charging the surface of the image carrier, a latent image forming step for forming an electrostatic latent image on the surface of the image carrier, and the surface of the image carrier. The electrostatic latent image formed on the substrate is developed using a developer to form a toner image, the transfer step of transferring the developed toner image to a transfer target, and the transferred toner image A fixing step for fixing, and the developer is the developer for developing an electrostatic image according to the exemplary embodiment.

In this image forming apparatus, for example, the part including the developing unit may have a cartridge structure (process cartridge) that can be attached to and detached from the image forming apparatus main body. As the process cartridge, a developer holding body is used. A process cartridge according to this embodiment that is provided at least and that accommodates the developer of this embodiment 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. 1 is a schematic configuration diagram showing a four-tandem color image forming apparatus. The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the main body of the image forming apparatus.

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

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

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

The electrostatic charge image (electrostatic latent 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, so that the surface of the photoreceptor 1Y On the other hand, this is a so-called negative latent image formed by the flow of the charged electric charge while the electric charge in the portion not irradiated with the laser beam 3Y remains.
The electrostatic charge image formed on the photoreceptor 1Y in this way is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) by the developing device 4Y.

In the developing device 4Y, for example, an electrostatic charge image developer 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 a developer roll (developer holder). Is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. .
From the viewpoint of development efficiency, image graininess, gradation reproducibility, and the like, a bias potential (development bias) in which an AC component is superimposed on a DC component may be applied to the developer holder. Specifically, when the developer holder DC applied voltage Vdc is −300 to −700 V, the developer holder AC voltage peak width Vp-p may be in the range of 0.5 to 2.0 kV.
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 position, a primary transfer bias is applied to the primary transfer roller 5Y, and electrostatic force directed from the photoreceptor 1Y to the primary transfer roller 5Y is applied to the toner image. As a result, the toner image on the photoreceptor 1 </ b> Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is a (+) polarity opposite to the polarity (−) of the toner, and is controlled to about +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the cleaning device 6Y.

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

  The intermediate transfer belt 20 onto which the four color toner images have been transferred through the first to fourth units is arranged on the image transfer surface side of the intermediate transfer belt 20, the support roller 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer means) 26 is connected to a secondary transfer portion. On the other hand, the recording paper (transfer object) P is fed at a predetermined timing to the gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other via the supply mechanism, and the secondary transfer bias is supported. Applied to the roller 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied to the intermediate transfer belt 20. 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 to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (roll-type fixing means) 28, the toner image is heated, and the color-superposed toner image is melted to record the recording paper. Fixed onto P.

Next, the toner image fixed on the recording paper P is irradiated with ultraviolet rays from the ultraviolet irradiation means 32. Thereby, the unsaturated bond contained in the specific polyester resin constituting the toner image causes a polymerization reaction by the action of the photopolymerization initiator, and the specific polyester resin is cured. In order to accelerate the polymerization reaction, the viscosity of the toner image when the toner image is irradiated with ultraviolet rays is preferably low. For this reason, it is desirable that the toner image is irradiated with ultraviolet rays from the ultraviolet irradiation means 32 during the fixing by the fixing device 28 or immediately after the fixing.
In the toner containing the thermal polymerization initiator, the unsaturated polyester resin is cured in the heat fixing step.

As the wavelength of the ultraviolet rays irradiated by the ultraviolet irradiation means 32, a wavelength that allows the photopolymerization initiator contained in the toner to cause a polymerization reaction is selected, for example, from 280 nm to 440 nm.
The ultraviolet irradiation means 32 is not particularly limited as long as it can irradiate ultraviolet rays having a wavelength capable of causing a polymerization reaction by a photopolymerization initiator. For example, a metal halide lamp (wavelength range: 200 nm to 600 nm), Or, in the case of LED-UV, the selected wavelength may be any of 365/375/385 nm.
In FIG. 2, at least one of the pair of heating rolls of the fixing unit 115 may be UV transmissive, and the UV irradiation unit 120 may be incorporated in this roll.

  As shown in FIG. 3, the fixing device 28 includes a heating unit 29 and an ultraviolet irradiation unit 34, and at the same time, heat and ultraviolet rays can be applied to the toner image. In this case, the toner image is heated and fixed by a heating means such as a heater, and at the same time, ultraviolet rays are irradiated from an ultraviolet irradiation means 32 such as an LED-UV lamp to add unsaturated double bonds in the unsaturated polyester resin by an addition reaction. Harden.

When the electrostatic image developing toner of this embodiment contains a photopolymerization initiator, particularly a bisacylphosphine oxide compound, the fixing step of fixing the image formed with the toner includes a step of irradiating the image with ultraviolet rays. It is preferable to include.
In the present embodiment, when the toner contains a photopolymerization initiator, it is preferable to simultaneously perform the step of heat-fixing the transferred toner image and the ultraviolet irradiation step.
The wavelength of the ultraviolet rays to be irradiated preferably includes light in the wavelength range absorbed by the bisacylphosphine oxide, more preferably contains a component of 200 to 600 nm, and particularly preferably contains a wavelength component of 350 to 450 nm. preferable.
Although there is no restriction | limiting in particular as a light source which can be used for the said exposure process, A mercury lamp, a metal halide lamp, and LED-UV light source can illustrate preferably.
The exposure amount of light in the exposure step may be an amount that the unsaturated polyester resin is cured, but is preferably 10~4,000mJ / cm ^2, is 20~2,500mJ / cm ² It is more preferable.

  Examples of the transfer target to which the toner image is transferred include plain paper and OHP sheet used for electrophotographic copying machines, printers, and the like.

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

4). Process Cartridge FIG. 2 is a schematic configuration diagram showing a preferred example embodiment of a process cartridge containing an electrostatic charge image developer according to this embodiment. The process cartridge 200 combines the developing device 111 with the photosensitive member 107, the charging roller 108, the photosensitive member cleaning device 113, the opening 118 for exposure, and the opening 117 for static elimination exposure using the mounting rail 116. , And integrated. In FIG. 2, reference numeral 300 denotes a transfer target.
The process cartridge 200 is detachable from an image forming apparatus main body including a transfer device 112, a fixing device 115, an ultraviolet irradiation unit 120, and other components not shown. The image forming apparatus is configured together with the image forming apparatus main body.

  The process cartridge 200 shown in FIG. 2 includes a photosensitive member 107, a charging device 108, a developing device 111, a cleaning device 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. The devices may be selectively combined. In the process cartridge of the present embodiment, in addition to the developing device 111, the photosensitive member 107, the charging device 108, the cleaning device (cleaning means) 113, the opening 118 for exposure, and the opening 117 for static elimination exposure. You may provide at least 1 sort (s) selected from the group comprised from these.

  The image forming method of the present embodiment may further include a recycling step. The recycling step is a step of transferring the electrostatic charge image developing toner collected in the cleaning step to a developer layer. The image forming method including the recycling process is performed using an image forming apparatus such as a toner recycling system type copying machine or facsimile machine. Further, the present invention may be applied to a recycling system in which the cleaning process is omitted and toner is collected simultaneously with development.

  Hereinafter, although this embodiment is described based on an Example, these Examples do not limit this embodiment at all. In the following description, “parts” and “%” mean “parts by weight” and “% by weight”, respectively, unless otherwise specified.

(Preparation example of amorphous unsaturated polyester resin particle dispersion A)
In a heat-dried two-necked flask, 25 mol parts of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2,2) -2,2-bis (4- Hydroxyphenyl) propane 25 mol part, terephthalic acid 6.4 mol part, fumaric acid 32.1 mol part, n-dodecenyl succinic acid 11.5 mol part, acid component (total mol of terephthalic acid, fumaric acid, n-dodecenyl succinic acid 0.05 mol part of dibutyltin oxide with respect to several 50 mol), nitrogen gas was introduced into the container and the temperature was maintained in an inert atmosphere, and the temperature was increased at 150 ° C. to 230 ° C. for 12 hours to 20 hours. A polymerization reaction was performed, and then the pressure was gradually reduced at 210 ° C. to 250 ° C. to synthesize an amorphous unsaturated polyester resin.
The resulting amorphous unsaturated polyester resin 3,000 parts by weight, thermal polymerization initiator V-40 90 parts by weight, biphenyl (DP) 60 parts by weight, ion-exchanged water 10,000 parts by weight, sodium dodecylbenzenesulfonate 90 Part by weight is put into an emulsification tank of a high-temperature, high-pressure emulsifier (Cabitron CD1010), heated and melted to 130 ° C, dispersed at 110 ° C for 30 minutes at a flow rate of 3 L / m, 10,000 rpm, and passed through a cooling tank. Thus, an amorphous unsaturated polyester resin particle dispersion A containing V-40 and biphenyl having a solid content of 30% and a volume average particle diameter D _50v of 120 nm was prepared.
Here, V-40 is 1,1′-azobis (cyclohexane-1-carbonitrile) (10 hour half-life temperature 88 ° C.) (manufactured by Wako Pure Chemical Industries, Ltd.).

(Preparation example of crystalline polyester resin particle dispersion)
In a heat-dried three-necked flask, 230 parts of 1,10-dodecanedioic acid, 160 parts of 1,9-nonanediol, and 0.2 part of dibutyltin oxide as a catalyst were added, and then the pressure in the three-necked flask was reduced by a vacuum operation. The reaction was allowed to proceed under an inert atmosphere by substituting with nitrogen at 180 ° C. for 5 hours by mechanical stirring and refluxed. During the reaction, water produced in the reaction system was distilled off. Thereafter, the temperature was gradually raised to 235 ° C. under reduced pressure, and after stirring for 2 hours, the molecular weight was confirmed by GPC. When the weight average molecular weight reached 28,500, vacuum distillation was stopped. A crystalline polyester resin was obtained.
After putting 100 parts of this crystalline polyester resin, 3.0 parts of polymerization initiator V-40, 35 parts of ethyl acetate, and 35 parts of isopropyl alcohol into a separable flask, this was sufficiently mixed and dissolved at 75 ° C. 5.5 parts of a 10% aqueous ammonia solution was added dropwise. The heating temperature is lowered to 60 ° C., and ion-exchanged water is added dropwise with stirring using a liquid feed pump at a liquid feed speed of 6 g / min. After the liquid becomes cloudy, the liquid feed speed is increased to 25 g / min. When the amount reached 400 parts, dropping of ion-exchanged water was stopped. Thereafter, the solvent was removed under reduced pressure to obtain a crystalline polyester resin particle dispersion B. The obtained crystalline polyester resin particles had a volume average particle size of 140 nm, and then distilled water was added to adjust the solid content concentration of the polyester resin particles to 25%. In Examples 17 to 24, it was used as polyester dispersion B.
Further, in the above phase inversion emulsification, instead of using 3.0 parts of the polymerization initiator V-40, a dispersion obtained by using 3.0 parts of IRG819 was used as the polyester dispersion B. Used in 32.

(Example of preparation of pigment dispersion)
Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika Kogyo Co., Ltd.) 45 parts by weight ionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by weight ion-exchanged water 200 parts by weight or more It melt | dissolved and disperse | distributed for 10 minutes with the homogenizer (IKA company ultra turrax), and the colorant dispersion liquid 1 with a center diameter of 170 nm was obtained.

(Example of preparation of release agent dispersion 1)
Polyalkylene FNP0092 (melting temperature 92 ° C, manufactured by Nippon Seiwa Co., Ltd.) 45 parts by weight Cationic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by weight Ion-exchanged water 200 parts by weight Then, the mixture was sufficiently dispersed with an Ultra Turrax T50 manufactured by IKA, and then dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion 1 having a center diameter of 180 nm and a solid content of 25%.

The compounds used in the examples are described below.
V40: 1,1′-azobis (cyclohexane-1-carbonitrile) (manufactured by Wako Pure Chemical Industries, Ltd.)
IRG819: Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (IRGACURE819, manufactured by Ciba Japan)

Example 1
(Preparation of Toner 1)
-Ion exchange water: 290 parts-Amorphous unsaturated polyester resin particle dispersion A: 547 parts by weight-Colorant dispersion: 85 parts by weight-Release agent dispersion 1: 94 parts by weight-Anionic surfactant ( Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK, 20% by weight): 2.8 parts The above components are placed in a reaction vessel equipped with a thermometer, pH meter, and stirrer, and the temperature is controlled with a mantle heater from the outside. The temperature was maintained at 30 ° C. and a stirring speed of 150 rpm for 30 minutes. Thereafter, a 0.3N nitric acid aqueous solution was added to adjust the pH in the aggregation process to 3.0.
A PAC aqueous solution in which 0.7 part of PAC (polyaluminum chloride, manufactured by Asada Chemical Industry Co., Ltd .: # 100) was dissolved in 7 parts of ion-exchanged water while being dispersed with a homogenizer (manufactured by IKA Japan: Ultra Tarax T50). Was added. Thereafter, while stirring, the temperature was raised to 50 ° C., the particle size was measured with Coulter Multisizer II (aperture diameter: 50 μm, manufactured by Coulter, Inc.), and the volume average particle size was set to 5.0 μm. Thereafter, 93 parts of an amorphous unsaturated polyester resin dispersion A93 was additionally added to allow the resin particles to adhere to the surface of the aggregated particles (shell structure).
Subsequently, 20 parts by weight of a 10 wt% NTA (nitrilotriacetic acid) metal salt aqueous solution (Cyrest 70: manufactured by Cylest Co., Ltd.) was added, and then the pH was adjusted to 9.0 using a 1N aqueous sodium hydroxide solution. Thereafter, the temperature was raised to 75 ° C. at a rate of temperature rise of 1.0 ° C./min, held at 75 ° C. for 3 hours, then cooled and filtered to obtain coarse toner particles. This was further re-dispersed with ion-exchanged water and filtered, 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. Toner particles were obtained.
To 100 parts by weight of the toner particles obtained, 1.5 parts by weight of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 weight of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) Were mixed and blended at 10,000 rpm for 30 seconds using a sample mill. Thereafter, the toner (1) was prepared by sieving with a vibration sieve having an opening of 45 μm. The toner (1) obtained had a volume average particle diameter of 6.1 μm.

<Creation of carrier>
-Toluene: 14 parts-Styrene-methyl methacrylate copolymer (component ratio: 80/20 (weight ratio), weight average molecular weight: 70,000): 2 parts-MZ500 (zinc oxide, Titanium Industry Co., Ltd.): 0 .6 parts The above components were mixed and stirred with a stirrer for 10 minutes to prepare a coating layer forming solution in which zinc oxide was dispersed. Next, this coating solution and 100 parts of ferrite particles (volume average particle size: 38 μm) are put in a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes, and then degassed by further reducing pressure while heating. The carrier was prepared by drying.

<Preparation of developer>
The obtained carrier and toner (1) were mixed with a V blender at a ratio of 100 parts: 8 parts, respectively, to prepare developer (1). The dimethylacrylamide content in the toner (1) was measured and found to be 1.8%.

(Production of toners 2 to 8 and developers 2 to 8 in Examples 2 to 8)
The thermal polymerization initiator is used as it is, and the aromatic compound having two or more aromatic rings is changed as shown in Examples 2 to 8 in Table 1, and the same parts by weight as in Example 1 are blended. In the same manner as in Example 1, toners 2 to 8 were prepared and subsequently used in Examples 2 to 8 as developers 2 to 8 in the same manner as in Example 1.

(Production of toners 9 to 16 and developers 9 to 16 in Examples 9 to 16)
Except for using the same weight part of the photopolymerization initiator IRGACURE819 in place of the thermal polymerization initiator V-40 and further blending aromatic compounds having two or more aromatic rings as shown in Examples 9 to 16 of Table 1. In the same manner as in Example 1, toners 9 to 16 were prepared and used in Examples 9 to 16.

(Production of Toners 17 to 32 and Developers 17 to 32 of Examples 17 to 32)
In toner particles 1 to 16, instead of using amorphous polyester particle dispersion A, a mixture of 91 parts by weight of amorphous polyester particle dispersion A and 9 parts by weight of crystalline polyester particle dispersion B is used. Except that, toners 17 to 32 and developers 17 to 32 were produced in the same manner. In dispersion A and dispersion B, V-40 or IRG819 was blended as a common initiator.

(Preparation of Comparative Toner 1 and Comparative Developer 1 of Comparative Example 1)
In the preparation example of the amorphous unsaturated polyester resin particle dispersion A, an amorphous unsaturated polyester resin particle dispersion C containing only biphenyl was prepared without using the thermal polymerization initiator V-40. Comparative toner 1 and comparative developer 1 were prepared in the same manner as toner 1 except that the same amount was used instead of dispersion A.

<Evaluation of fixed image quality>
For the evaluation of the image quality of the fixed image, the above-mentioned developers A1 to A32 and comparative developer 1 are used. In the modified machine of Docu Center Color f450 manufactured by Fuji Xerox Co., Ltd., a two-roll type fixing machine is modified. Then, the fixing roll temperature was set to 130 ° C., and the process speed was adjusted to 60 mm / sec. In toners 9 to 16 and 25 to 32 containing a photopolymerization initiator, ultraviolet rays were irradiated for 1 second from a UV-LED lamp (NCCU033: manufactured by Nichia Corporation) (illuminance: 350 mW / cm ² ). .

The obtained image was subjected to a flexibility test and a pencil hardness test, and the following five-level evaluation was performed.
(Flexibility test)
The test was conducted according to the mandrel method described in ISO-1594.
(1) As a bending test device, a device for bending by hand was used.
(2) Mandrel The diameter of the mandrel was 2 mm.
(3) Test plate A rectangle of about 100 mm × 50 mm and a thickness of 0.3 mm or 1 mm.
(4) Measurement The apparatus was filled with a mandrel having a diameter of 2 mm (because the diameter was small, it was a great stress condition). The test piece was fixed so that the image surface was opposite to the mandrel. The handle was pulled over 1-2 seconds and tilted 180 °. Check for cracks and cracks on the coating surface. If necessary, test with a smaller diameter. Visual observation was performed. The coating surface within 10 mm from the end of the test piece was ignored, and cracking of the image and peeling from the substrate were confirmed.
The evaluation criteria were as follows.
5: There is no visual defect at all and there is no problem in actual use. 4: A slight image defect is confirmed by visual observation, but there is no problem in actual use. 3: Image defect is confirmed by visual observation, but in actual use. acceptable.
2: The image defect is visually confirmed and is not acceptable.

(Pencil hardness test)
A cyan solid image was printed on A4 paper using the cyan developer prepared in Examples 1 to 32, and then a pencil hardness test was performed by the method described in ISO-15184. The results obtained are summarized in Table 1.
In addition, the pencil hardness test evaluation was judged by scratching the image with a pencil of 9H to 6B and determining whether the image could be scraped. Specific evaluation criteria were as follows.
5: Image part cannot be sharpened with 4H pencil 4: Image part cannot be sharpened with pencil HB-3H 3: Image part cannot be sharpened with pencil 2B-6B 2: Image part can be sharpened with 6B pencil Things or images that were not fixed

1Y, 1M, 1C, 1K, 107 photoconductor (image carrier)
2Y, 2M, 2C, 2K, 108 Charging roller 3Y, 3M, 3C, 3K Laser beam 3, 110 Exposure device 4Y, 4M, 4C, 4K, 111 Developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer rollers 6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller (transfer means)
28, 115 Fixing device (fixing means)
29 Heating means (heater)
30 Intermediate transfer member cleaning device 32, 120 UV irradiation means 34 Conveying belt 112 Transfer device 116 Mounting rail 117 Opening portion 118 for static elimination exposure Opening portion 200 for exposure Process cartridge,
P, 300 Recording paper (transfer object)

Claims (14)

A binder resin, an aromatic compound having two or more aromatic rings, a colorant, a release agent and a polymerization initiator,
The binder resin contains an unsaturated polyester resin having an ethylenically unsaturated group,
The aromatic compound having two or more aromatic rings is a compound selected from the group consisting of a benzophenone compound, a bisacylphosphine oxide compound, a diphenyl compound, a terphenyl compound, and a quarterphenyl compound;
The polymerization initiator is an aliphatic azo thermal polymerization initiator or a bisacylphosphine oxide photopolymerization initiator,
Toner for developing electrostatic images.   The electrostatic image developing toner according to claim 1, comprising a bisacylphosphine oxide compound as the aromatic compound.   The electrostatic image developing toner according to claim 1, wherein the aromatic compound includes a compound selected from the group consisting of a diphenyl compound, a terphenyl compound, and a quaterphenyl compound.   The electrostatic image developing toner according to claim 1, wherein m-terphenyl is included as the aromatic compound.   The electrostatic image developing toner according to claim 1, wherein the unsaturated polyester resin is an amorphous polyester resin and / or a crystalline polyester resin.   The toner for developing an electrostatic charge image according to any one of claims 1 to 5, wherein the content of the unsaturated polyester resin in the binder resin is 50 to 80% by mass.   A developer for developing an electrostatic charge image, comprising the toner for developing an electrostatic charge image according to claim 1.   A toner cartridge comprising the electrostatic image developing toner according to claim 1.   A developer cartridge comprising the developer for developing an electrostatic charge image according to claim 7.   An image carrier, and a developing unit that develops an electrostatic latent image formed on the surface of the image carrier using a developer to form a toner image, wherein the developer is described in claim 7. And a developer for developing an electrostatic image. An image carrier,
Charging means for charging the surface of the image carrier;
Latent image forming means for forming an electrostatic latent image on the surface of the image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier using a developer to form a toner image;
Transfer means for transferring the developed toner image to a transfer medium;
Fixing means for fixing the transferred toner image,
The image forming apparatus, wherein the developer is the developer for developing an electrostatic image according to claim 7.   The image forming apparatus according to claim 11, further comprising an ultraviolet irradiation unit configured to irradiate the transferred toner image with ultraviolet rays. A charging step for charging the surface of the image carrier;
A latent image forming step of forming an electrostatic latent image on the surface of the image carrier;
A developing step of developing the electrostatic latent image formed on the surface of the image carrier using a developer to form a toner image;
A transfer step of transferring the developed toner image to a transfer target;
Fixing the transferred toner image, and
An image forming method, wherein the developer is the developer for developing an electrostatic image according to claim 7.   The image forming method according to claim 13, further comprising an ultraviolet irradiation step of irradiating the transferred toner image with ultraviolet rays.

Images