CN104808455B - Electrostatic image developing toner, electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

The invention provides a toner for developing electrostatic images, which has excellent color reproducibility of bright vermilion and light resistance of images. The toner for developing electrostatic images contains toner particles containing a binder resin, a xanthophyll compound, and a xanthophyll compound. The invention also provides a developer containing the electrostatic image developing toner, and a toner cartridge containing the electrostatic image developing toner.

Description

Electrostatic image developing toner, electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method

Technical Field

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

Background

In general, in electrophotographic image formation, toners of 4 colors, i.e., yellow (Y), magenta (M), cyan (C), and black (K), are used to reproduce colors. In order to reproduce a color that is difficult to reproduce only with the 4 color toners (YMCK), a toner of a color other than YMCK is also used.

For example, patent document 1 discloses a magenta toner containing a water-insoluble pigment compound represented by a specific formula (1) and a binder resin.

Patent document 2 discloses a magenta toner containing c.i. pigment red 48-3 and c.i. pigment red 48-1 in a ratio of 8:2 to 5: 5.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open publication No. 2012 and 208496

[ patent document 2] Japanese patent application laid-open No. 2011-

Disclosure of Invention

[ problems to be solved by the invention ]

The invention provides a toner for developing electrostatic images, which has bright vermilion color reproducibility and excellent image light resistance.

[ means for solving the problems ]

The above problems are solved by the following means. That is to say that the first and second electrodes,

The first aspect of the present invention is directed to the invention,

A toner for developing an electrostatic image, comprising toner particles, wherein the toner particles contain a binder resin and xanthophylls.

A second aspect of the present invention is directed to the invention,

The toner for developing electrostatic images according to the first aspect of the present invention, wherein the total amount of the xanthophylls and the xanthophylls is 0.5 mass% or more and 20 mass% or less of the toner particles.

A third aspect of the present invention is directed to the invention,

The electrostatic image developing toner according to the first or second aspect of the present invention, wherein a mass ratio of the xanthophylls to the phylls contained in the toner particles (xanthophylls/phylls) is 0.5 or more and 3.0 or less.

A fourth aspect of the present invention is directed to the invention,

The toner for developing an electrostatic image according to any one of the first to third aspects of the present invention, wherein the xanthophyll is astaxanthin.

A fifth aspect of the present invention is directed to the invention,

The electrostatic image developing toner according to any one of the first to fourth aspects of the present invention, wherein the lycopene is lycopene.

A sixth aspect of the present invention is directed to the invention,

An electrostatic image developer comprising the toner for electrostatic image development according to any one of the first to fifth aspects.

A seventh aspect of the present invention is directed to the invention,

A toner cartridge containing the toner for electrostatic image development according to any one of the first to fifth aspects and being detachable from an image forming apparatus.

An eighth aspect of the present invention is directed to the invention,

A process cartridge having a developing part which contains the electrostatic image developer of the sixth aspect and develops an electrostatic image formed on a surface of an image holding body into a toner image by the electrostatic image developer, and which is detachable from an image forming apparatus.

a ninth aspect of the present invention is directed to the invention,

An image forming apparatus having:

An image holding body;

A charging member that charges a surface of the image holding body;

An electrostatic image forming member that forms an electrostatic image on a surface of the image holding body after charging;

A developing member that contains the electrostatic image developer according to the sixth aspect and develops an electrostatic image formed on a surface of the image holding body into a toner image by the electrostatic image developer;

A transfer member that transfers a toner image formed on a surface of the image holding body onto a surface of a recording medium;

And a fixing member that fixes the toner image transferred onto the surface of the recording medium.

A tenth aspect of the present invention relates to the invention,

An imaging method having:

A step of charging a surface of the image holder;

An electrostatic image forming step of forming an electrostatic image on the surface of the image holder after charging;

A developing step of developing an electrostatic image formed on a surface of the image holding body into a toner image by the electrostatic image developer of the sixth aspect;

A transfer step of transferring the toner image formed on the surface of the image holding body onto a surface of a recording medium;

And a fixing step of fixing the toner image transferred onto the surface of the recording medium.

[ Effect of the invention ]

According to the first aspect of the present invention, it is possible to provide a toner for electrostatic charge image development excellent in color reproducibility of vivid vermillion and light resistance of an image, as compared with a case where toner particles do not satisfy the requirement of containing both xanthophylls and xanthophylls.

According to the second aspect of the present invention, it is possible to provide a toner for electrostatic charge image development which is more excellent in the color reproducibility of vivid vermillion and the light resistance of an image than in the case where the ratio of the total amount of xanthophylls and xanthophylls to the toner particles is not within the range.

According to the third aspect of the present invention, it is possible to provide a toner for electrostatic image development which is more excellent in light resistance of an image than a case where the mass ratio of xanthophylls to xanthophylls contained in toner particles is not within the range.

According to the fourth aspect of the present invention, it is possible to provide a toner for electrostatic image development which is more excellent in light resistance of an image than a case where the xanthophyll is not astaxanthin.

According to the fifth aspect of the present invention, a toner for electrostatic image development, which is more excellent in light resistance of an image, can be provided as compared with the case where the phytoene is not lycopene.

According to the sixth aspect of the present invention, an electrostatic image developer excellent in vivid vermillion color reproducibility and light resistance of an image can be provided as compared with a case where toner particles contained in a toner do not satisfy the requirement of containing both xanthophylls and xanthophylls.

According to the seventh aspect of the present invention, a toner cartridge excellent in color reproducibility of vivid vermillion and light resistance of an image can be provided as compared with a case where toner particles contained in a toner do not satisfy a requirement of containing both xanthophylls and xanthophylls.

According to the eighth aspect of the present invention, as compared with the case where the toner particles contained in the toner in the developer do not satisfy the requirement of containing both xanthophylls and xanthophylls, a process cartridge excellent in color reproducibility of vivid vermillion and light resistance of an image can be provided.

According to the ninth aspect of the present invention, an image forming apparatus excellent in color reproducibility of vivid vermillion and light resistance of an image can be provided as compared with a case where toner particles contained in a toner in a developer do not satisfy the requirement of containing both xanthophylls and xanthophylls.

According to the tenth aspect of the present invention, an image forming method excellent in color reproducibility of vivid vermillion and light resistance of an image can be provided as compared with a case where toner particles contained in a toner in a developer do not satisfy the requirement of containing both xanthophylls and xanthophylls.

Drawings

Fig. 1 is a schematic structural view showing an example of an image forming apparatus of an embodiment of the present invention.

Fig. 2 is a schematic structural view showing an example of a process cartridge of the embodiment of the present invention.

Description of the symbols

10V, 10Y, 10M, 10C, 10K imaging unit

1V, 1Y, 1M, 1C, 1K photoreceptors (example of image holder)

2V, 2Y, 2M, 2C, 2K charging roller (example of charging member)

3V, 3Y, 3M, 3C, 3K exposure device (example of electrostatic image forming member)

4V, 4Y, 4M, 4C, 4K developing devices (examples of developing members)

5V, 5Y, 5M, 5C, 5K primary transfer rollers (examples of primary transfer members)

6V, 6Y, 6M, 6C, 6K photoreceptor cleaning device (example of cleaning member)

8V, 8Y, 8M, 8C, 8K toner cartridge

20 intermediate transfer belt (example of intermediate transfer member)

21 intermediate transfer member cleaning device

22 drive roller

23 support roller

24 opposite roller

26 Secondary transfer roller (example of secondary transfer member)

28 fixing device (example of fixing member)

P recording paper (example of recording medium)

107 photoreceptor (example of image holder)

108 charging roller (example of charging member)

109 Exposure device (example of Electrostatic image Forming Member)

111 developing device (example of developing member)

112 transfer device (example transfer member)

113 photoreceptor cleaning device (example cleaning member)

115 fixing device (example of fixing member)

116 mounting rail

117 shell

118 opening for exposure

200 processing box

300 recording paper (example of recording medium)

Detailed Description

embodiments of the present invention will be explained below. The description and examples are intended to be illustrative of the invention, but not to limit the scope of the invention.

in the present specification, (meth) acryloyl means acryloyl and methacryloyl, (meth) acrylic means acrylic acid and methacrylic acid, and (meth) acryloyl means acryloyl and methacryloyl.

< toner for developing electrostatic image >

The toner for electrostatic image development (also referred to as "toner") according to an embodiment of the present invention includes toner particles, and may further include an external additive. That is, in the embodiment of the present invention, the toner particles may be used as a toner, or may be used as a toner after an external additive is added to the toner particles from the outside.

the toner particles contained in the toner according to the present invention contain a binder resin, and xanthophylls. The toner containing the toner particles having the above-described structure is excellent in vivid vermillion color reproducibility and is excellent in light resistance of an image.

In some cases, a document having a vermilion stamp is copied or an image recording material including a vermilion stamp image is created by an image forming apparatus of an electrophotographic method. Since a document with a stamp is a document or a document that needs to be stored for a long period of time, it is desirable that the image forming toner can satisfactorily reproduce vivid vermillion of a stamp and has excellent image storability.

Conventionally, in image formation of a vermilion seal, a mixture of yellow toner and magenta toner is used, or a toner containing a fluorescent pigment or a lake pigment of red is used. However, the reproducibility of brightness or color saturation is not sufficient for the mixed color of the yellow toner and the magenta toner, and the light fastness of an image is insufficient when a toner containing a fluorescent pigment or a lake pigment of red is used.

In contrast, the toner according to the embodiment of the present invention contains xanthophylls and xanthophylls as colorants. Xanthophylls and xanthophylls are pigments that can reproduce vivid vermillion, and also have an effect of suppressing photodegradation of an image by themselves. That is, when oxygen reactive species are generated in an image by exposure to light such as ultraviolet rays, the xanthophylls and the xanthophylls absorb energy from the oxygen reactive species and release the energy as heat (thermal relaxation), and the oxygen reactive species are eliminated without changing their own chemical structures, and as a result, the photodegradation of the image is suppressed. Further, the effect of eliminating oxygen reactive species is enhanced by the use of both xanthophylls and xanthophylls, and the light fastness of the image is improved as compared with the case of using either one.

The toner according to the embodiment of the present invention preferably has a L value in the CIE1976L a b color system, a value in the range of 55 to 63, a value in the range of 65 to 73, and b value in the range of 47 to 55 in an image formed on paper (e.g., non-coated printing paper having an ISO whiteness of 80% or more) by the toner.

[ toner particles ]

The toner particles contain a binder resin and xanthophylls, and may further contain a releasing agent or other internal additives. Hereinafter, the components contained in the toner particles will be described in detail.

Colorants-

the toner particles contain xanthophylls and xanthophylls.

The total amount of xanthophylls and xanthophylls is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 2.0% by mass or more of the mass of the toner particles, from the viewpoint that the vivid vermillion color reproducibility and the light resistance of the image are more excellent. On the other hand, from the viewpoint of suppressing the decrease in color reproducibility of vermillion due to the decrease in charge maintenance property, it is preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, and still more preferably 8% by mass or less. If the charge retention property is lowered, the reproducibility of vermillion may be lowered.

From the viewpoint of more excellent light resistance of the image, the mass ratio of xanthophylls to xanthophylls contained in the toner particles (xanthophylls/xanthophylls) is preferably 0.5 to 3.0, more preferably 0.5 to 2.5, more preferably 0.75 to 2.25, and still more preferably 1.0 to 2.0.

The content of xanthophylls in the toner particles is preferably 0.2% by mass or more, more preferably 1.0% by mass or more, and still more preferably 2.0% by mass or more, from the viewpoint of further improving the color reproducibility of vivid vermillion and the light resistance of an image. On the other hand, from the viewpoint of charge maintenance, it is preferably 15% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less.

The content of the phytofluenes in the toner particles is preferably 0.2% by mass or more, more preferably 1.0% by mass or more, and still more preferably 1.5% by mass or more, from the viewpoint of further excellence in color reproducibility of vivid vermillion and light fastness of an image. On the other hand, from the viewpoint of charge maintenance, it is preferably 15% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less.

Examples of xanthophylls include astaxanthin, canthaxanthin, zeaxanthin, rhodoxanthin, fucoxanthin, antheraxanthin, violaxanthin, cryptoxanthin, chitin, capsanthin, lutein, echinenone, 3-hydroxyechinenone, cyanophytin, limoxanthin, diadinoxanthin, cudamin, neolutein, rhodoxanthin, rubixanthin, amarocoxanthin A ((3S,5R,6'S) -3,5,6' -trihydroxy-6, 7-didehydro-5, 6,7',8' -tetrahydro- β, ε -lutein-3 ',8' -dione, ア マ ロ ー シ ア キ サ ン チ ン A), Halothianxanthin ((3S,3'S,5' R,6'S) -7, 8-didehydro-5', 6 '-epoxy-5', 6',7',8 '-tetrahydro-8' -oxo- β, β -lutein-3, 3 '-dione, ハ ロ シ ン チ ア キ サ ン チ ン), tuna flavin, polymetaxanthin, Deinochrome (デ イ ノ ク ロ ー ム), 3-hydroxy- β, ε -lutein-3' -one, capsanthin-3, 6-epoxide, capsorubin, erythraea curcin (ピ ト ス ポ ラ ム キ サ ン チ ン), retinol, retinal, retinoic acid, and the like. Among them, astaxanthin, canthaxanthin, and lutein are preferable, and astaxanthin is more preferable, from the viewpoint that the light resistance of the image is more excellent.

Examples of the phytofluenes include lycopene (リ コ ペ ン) (also referred to as "リ コ ピ ン (lycopene)"), rhodotorula, α -phytoene, β -phytoene, γ -phytoene, δ -phytoene, ∈ -phytoene, neurosporene, phytoene, and phytofluene. Among them, lycopene and β -lycopene are preferable, and lycopene is more preferable, from the viewpoint of further excellent light fastness of the image.

In the present embodiment, a case containing both astaxanthin and lycopene is preferable. In this case, the mass ratio of astaxanthin to lycopene (astaxanthin/lycopene) contained in the toner particles is preferably 0.5 or more and 3.0 or less, more preferably 0.5 or more and 2.5 or less, still more preferably 0.75 or more and 2.25 or less, and still more preferably 1.0 or more and 2.0 or less, from the viewpoint of further excellent light resistance of the image.

The toner particles may contain other colorants in addition to the xanthophylls and the xanthophylls. The other colorant may be a pigment or a dye, and a pigment is preferable from the viewpoint of light resistance and water resistance.

Examples of other colorants include: white pigments such as SiO2 (silica), TiO2 (titanium dioxide), and Al2O3 (alumina); red pigments and dyes such as c.i. pigment red 185, c.i. pigment red 122, c.i. pigment red 48:1, c.i. pigment red 48:3, c.i. pigment red 57:1, rose bengal and the like; yellow pigments and dyes such as c.i. pigment yellow 97, c.i. pigment yellow 12, quinoline yellow, and chrome yellow; green pigments and dyes such as malachite green oxalate; blue pigments and dyes such as c.i. pigment blue 15:1, c.i. pigment blue 15:3, aniline blue, copper oil blue, ultramarine, phthalocyanine blue, and chlorinated methylene blue; black pigments and dyes such as carbon black, lamp black, and nigrosine; and the like.

White pigments such as silica, titania, and alumina may be added to the toner particles for purposes other than coloring (for example, for purposes such as charge control of the toner).

from the viewpoint of ease of color reproducibility of vivid vermillion, the total amount of the white pigments in the toner particles is preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, still more preferably 5% by mass or less, and particularly preferably 1% by mass or less.

From the viewpoint of ease of color reproducibility of vivid vermillion, the content of each colorant other than the xanthophylls, and the white pigment in the toner particles is preferably 1% by mass or less, more preferably 0.5% by mass or less, further preferably 0.1% by mass or less, further preferably detection limit or less and substantially not contained, and particularly preferably 0% by mass.

From the viewpoint of easy color reproducibility of vivid vermillion, the total amount of the xanthophylls, and the pigments and white pigments is preferably 85% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 99% by mass or more, and particularly preferably 100% by mass (that is, the total amount of the colorants other than the xanthophylls, and the pigments and white pigments is not included).

From the viewpoint of easy color reproducibility of vivid vermillion, the total amount of the xanthophylls and the phylls in the total amount of the colorants in the toner particles is preferably 30% by mass or more, more preferably 40% by mass or more, further preferably 50% by mass or more, further preferably 60% by mass or more, further preferably 70% by mass or more, further preferably 80% by mass or more, further preferably 90% by mass or more, and particularly preferably 100% by mass (that is, not containing any other colorant than the xanthophylls and the phylls).

Binder resin-

The toner particles contain a binder resin. Examples of the binder resin include: styrenes (e.g., styrene, p-chlorostyrene, alpha-methylstyrene, etc.); (meth) acrylic acid esters (e.g., methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc.); ethylenically unsaturated nitriles (e.g., (meth) acrylonitrile, etc.); vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.); vinyl ketones (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.); homopolymers or copolymers of olefins (e.g., ethylene, propylene, butadiene, etc.) and the like.

Representative examples of the binder resin include polyester resins, epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polystyrene, styrene-alkyl (meth) acrylate copolymers, styrene- (meth) acrylonitrile copolymers, styrene-butadiene copolymers, and styrene-maleic anhydride copolymers.

these resins may be used alone in 1 kind, or may be used in combination in2 or more kinds.

The content of the binder resin in the toner particles is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and further preferably 60% by mass or more and 85% by mass or less.

As the binder resin, polyester resin is suitable. The polyester resin may be used in combination with an amorphous polyester resin and a crystalline polyester resin from the viewpoint of more excellent color reproducibility of vivid vermillion.

Examples of the polyester resin include polycondensates of polycarboxylic acids and polyhydric alcohols. The polyester resin may be commercially available or may be synthesized.

Examples of the polycarboxylic acid include: aliphatic dicarboxylic acids (e.g., oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), anhydrides thereof, or lower (e.g., carbon number of 1 to 5) alkyl esters thereof. Among them, as the polycarboxylic acid, for example, an aromatic dicarboxylic acid is preferable.

as the polycarboxylic acid, a tri or more carboxylic acid having a cross-linking structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the tri-or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters thereof.

the polycarboxylic acid may be used alone in 1 kind, or may be used in combination in2 or more kinds.

Examples of the polyhydric alcohol include aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol a, etc.), and aromatic diols (e.g., ethylene oxide adduct of bisphenol a, propylene oxide adduct of bisphenol a, etc.). Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.

As the polyol, trihydric or higher alcohols having a cross-linked structure or a branched structure may be used in combination with the dihydric alcohol. Examples of the trihydric or higher alcohols include glycerol, trimethylolpropane, pentaerythritol, and the like.

The polyhydric alcohol may be used alone in 1 kind, or may be used in combination in2 or more kinds.

The glass transition temperature (Tg) of the polyester resin is preferably 50 ℃ to 80 ℃ and more preferably 50 ℃ to 65 ℃.

The glass transition temperature is obtained from a Differential Scanning Calorimetry (DSC) curve obtained by DSC. More specifically, it is obtained by "extrapolating the glass transition starting temperature" as described in the method for determining the glass transition temperature according to JIS K7121-1987, "method for measuring the transition temperature of plastics".

The weight average molecular weight (Mw) of the polyester resin is preferably 5,000 to 1,000,000, and more preferably 7,000 to 500,000.

The number average molecular weight (Mn) of the polyester resin is preferably 2,000 to 100,000.

The molecular weight distribution Mw/Mn of the polyester resin is preferably 1.5 to 100, more preferably 2 to 60.

The weight average molecular weight and number average molecular weight of the resin were determined by Gel Permeation Chromatography (GPC). The measurement of the molecular weight by GPC was carried out using HLC-8120 manufactured by Tosoh corporation as a measuring device, TSK gel Super HM-M15cm manufactured by Tosoh corporation as a column, and tetrahydrofuran as a solvent. The weight average molecular weight and the number average molecular weight were calculated using a molecular weight calibration curve prepared from the measurement results by monodisperse polystyrene standard samples.

Anti-sticking agents

Examples of the antiblocking agent include: a hydrocarbon wax; natural waxes such as carnauba wax, rice bran wax, candelilla wax, and the like; synthetic or mineral/petroleum-based waxes such as montan wax; ester-based waxes such as fatty acid esters and montanic acid esters; and the like. The antiblocking agent is not limited to these.

The melting temperature of the antiblocking agent is preferably 50 ℃ to 110 ℃ inclusive, and more preferably 60 ℃ to 100 ℃ inclusive.

The melting temperature of the releasing agent is obtained from a DSC curve obtained by Differential Scanning Calorimetry (DSC) according to the "melting peak temperature" described in the method of determining the melting temperature of JIS K7121-1987, "method of measuring transition temperature of plastics".

The content of the releasing agent in the toner particles is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less.

Inorganic oxide particles

The toner particles may also contain inorganic oxide particles. Examples of the inorganic oxide include metal oxides such as SiO2 (silica), TiO2 (titania), Al2O3 (alumina), CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO — SiO2, K2O · (TiO2) n, Al2O3 · 2SiO2, CaCO3, MgCO3, BaSO4, and MgSO 4.

The surface of the inorganic oxide particles may not be subjected to a hydrophobization treatment in advance, or may be subjected to a hydrophobization treatment in advance.

The content of the inorganic oxide particles in the toner particles is preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, still more preferably 5% by mass or less, and particularly preferably 1% by mass or less, from the viewpoint of not affecting the toner hue.

Other additives

Examples of the other additives include known additives such as magnetic substances, charge control agents, and inorganic powders. These additives are contained as internal additives in the toner particles.

Characteristics of the toner particles

The toner particles may be toner particles having a single-layer structure, or may be toner particles having a so-called core-shell structure composed of a core portion (core particle) and a coating layer (shell layer) covering the core portion. The core-shell structured toner particles may be constituted, for example, by a core portion constituted by containing a binder resin, a colorant, and other additives such as a releasing agent as needed, and a coating layer constituted by containing a binder resin.

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

Various average particle diameters and various particle size distribution indices of toner particles were measured using a Coulter Multisizer II (manufactured by Beckman Coulter Co.), and using ISOTON-II (manufactured by Beckman Coulter Co.) as an electrolyte.

In the measurement, a measurement sample of 0.5mg to 50mg is added to 2ml of an aqueous solution of 5 mass% of a surfactant (preferably sodium alkylbenzenesulfonate) as a dispersant. This is added to 100ml to 150ml of the electrolyte solution.

The electrolyte solution in which the sample was suspended was dispersed and treated with an ultrasonic disperser for 1 minute, and the particle size distribution of particles having a particle size range of 2 μm to 60 μm was measured by a Coulter Multisizer II using pores having a pore diameter of 100 μm. The number of sampling particles was 50000.

For the particle size ranges (channels) divided based on the measured particle size distribution, cumulative distributions of volume and number are respectively drawn from the small diameter side, and the particle size at the cumulative percentage of 16% is defined as a volume particle size D16v and a number particle size D16p, the particle size at the cumulative percentage of 50% is defined as a volume average particle size D50v and a number average particle size D50p, and the particle size at the cumulative percentage of 84% is defined as a volume particle size D84v and a number particle size D84 p.

By using these, the volume average particle size distribution index (GSDv) was calculated in accordance with (D84v/D16v)1/2 and the number average particle size distribution index (GSDp) was calculated in accordance with (D84p/D16p) 1/2.

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

The shape factor SF1 is obtained by the following equation.

The formula is as follows: SF1 ═ ML2/a) × (pi/4) × 100

In the above equation, ML represents the absolute maximum length of the toner, and a represents the projected area of the toner.

specifically, the shape factor SF1 is mainly obtained by analyzing a microscope image or a Scanning Electron Microscope (SEM) image using an image analysis device, digitizing the image, and calculating as follows. Namely, it is obtained by: an optical microscope image of particles scattered on the surface of the slide glass was introduced into a Luzex image analyzer by a video camera to obtain the maximum length and the projected area of 100 particles, and the maximum length and the projected area were calculated by the above formula to find the average value.

[ external additive ]

As the external additive, for example, inorganic particles can be cited. Examples of the inorganic particles include SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO · SiO2, K2O · (TiO2) n, Al2O3 · 2SiO2, CaCO3, MgCO3, BaSO4, and MgSO 4.

The surface of the inorganic particles as the external additive may be subjected to a hydrophobic treatment. For example, the inorganic particles are immersed in a hydrophobizing treatment agent or the like to perform the hydrophobizing treatment. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used alone in 1 kind, or 2 or more kinds may be used in combination.

The amount of the hydrophobizing agent to be used is, for example, 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic particles.

Examples of the external additive include resin particles (resin particles such as polystyrene, PMMA, and melamine), a cleaning activator (for example, a metal salt of a higher fatty acid typified by zinc stearate, and particles of a fluorine-containing high molecular weight polymer).

The amount of the external additive added is, for example, preferably 0.01 to 5 mass%, more preferably 0.01 to 2 mass%, relative to the toner particles. [ method for producing toner ]

The toner according to the embodiment of the present invention may be prepared by preparing toner particles and using the toner particles as a toner, or may be prepared by adding an external additive to the toner particles.

the toner particles can be produced by any of a dry production method (e.g., a kneading and pulverizing method) and a wet production method (e.g., an aggregation coagulation method, a suspension polymerization method, a dissolution suspension method, and the like). These production methods are not particularly limited, and known production methods can be used. Among them, the toner particles are preferably obtained by an aggregation coagulation method.

When the toner particles are produced by the aggregation coagulation method, for example, specifically, the toner particles are produced at least by the steps of:

A step of preparing a resin particle dispersion in which resin particles as a binder resin are dispersed (resin particle dispersion preparation step);

A step of preparing a colorant dispersion in which at least one of xanthophylls and xanthophylls is dispersed (colorant dispersion preparation step);

A step of forming aggregated particles by aggregating the resin particles and the colorant (and other particles if necessary) in a dispersion liquid obtained by mixing the resin particle dispersion liquid and the colorant dispersion liquid (and other particle dispersion liquids if necessary) (aggregated particle forming step);

A step of heating the aggregated particle dispersion liquid in which the aggregated particles are dispersed to fuse and coagulate the aggregated particles, thereby forming toner particles (fusion-coagulation step).

The details of each step of the aggregation coagulation method are described below. In the following description, a method of obtaining toner particles containing a releasing agent is described, but the releasing agent is used as needed. Of course, other additives besides the antiblocking agent can also be used.

Resin particle dispersion preparation step

First, a resin particle dispersion liquid in which resin particles as a binder resin are dispersed is prepared.

The resin particle dispersion liquid is prepared, for example, by: the resin particles are dispersed in the dispersion medium by the surfactant.

The dispersion medium used in the resin particle dispersion liquid may be, for example, an aqueous medium.

Examples of the aqueous medium include: water such as distilled water and ion exchange water; alcohols; and the like. These can be used alone in 1 kind, also can be combined with more than 2 kinds.

Examples of the surfactant include: anionic surfactants such as sulfate salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salt type and quaternary ammonium salt type; nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyols; and the like. Among these, anionic surfactants and cationic surfactants can be specifically mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.

the surfactant may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

examples of the method of dispersing the resin particles in the dispersion medium include general dispersion methods using a rotary shear homogenizer, a ball mill with media, a sand mill, a Dyno mill, and the like. Depending on the kind of the resin particles, for example, the resin particles may be dispersed in the dispersion medium by a phase inversion emulsification method.

the phase inversion emulsification method is a method in which: the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, a base is added to the organic continuous phase (O phase) to neutralize it, and then water (W phase) is added to perform phase inversion from W/O to O/W, thereby dispersing the resin in an aqueous medium in the form of particles.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is 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 still more preferably 0.1 μm or more and 0.6 μm or less, for example.

As for the volume average particle diameter of the resin particles, a particle diameter distribution obtained by measurement with a laser diffraction type particle size distribution meter (for example, LA-700 manufactured by Horiba, ltd.) was used, and a volume cumulative distribution was drawn from the small diameter side based on the divided particle diameter ranges (channels), and the particle diameter at 50% by volume with respect to the entire particles was taken as the volume average particle diameter D50 v. The volume average particle size of the particles in the other dispersions was measured by the same method.

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

Colorant dispersion preparation step

The colorant dispersion liquid in which the colorant particles are dispersed is prepared by the same method as the method for preparing the resin particle dispersion liquid. That is, the dispersion medium, the surfactant, the dispersion method, the volume average particle diameter of the particles, and the particle content of the colorant dispersion are the same as those of the resin particle dispersion. In place of the colorant dispersion liquid, a colorant-containing resin particle dispersion liquid in which a colorant is dispersed in resin particles may be used.

Further, an anti-blocking agent dispersion liquid in which anti-blocking agent particles are dispersed is also prepared by the same method as the preparation method of the resin particle dispersion liquid. That is, the dispersion medium, the surfactant, the dispersion method, the volume average particle diameter of the particles, and the particle content of the anti-blocking agent dispersion are the same as those of the resin particle dispersion. In place of the releasing agent dispersion liquid, a releasing agent-containing resin particle dispersion liquid in which a releasing agent is dispersed in resin particles may be used.

-aggregate particle formation step-

Then, the resin particle dispersion liquid, the colorant dispersion liquid, and the releasing agent dispersion liquid are mixed.

Next, in the mixed dispersion, the resin particles, the colorant particles and the releasing agent particles are heterogeneously aggregated to form aggregated particles having a diameter close to that of the target toner particles and containing the resin particles, the colorant particles and the releasing agent particles.

Specifically, for example, the pH of the mixed dispersion is adjusted to acidity (for example, pH2 or more and 5 or less) while adding a coagulant to the mixed dispersion, and a dispersion stabilizer is added as necessary, followed by heating to a temperature near the glass transition temperature of the resin particles (specifically, for example, glass transition temperature of the resin particles is-30 ℃ or more and glass transition temperature of the resin particles is-10 ℃ or less), to aggregate the particles dispersed in the mixed dispersion, thereby forming aggregated particles.

In the aggregate particle formation step, for example, the mixed dispersion may be stirred in a rotary shear homogenizer at room temperature (e.g., 25 ℃) with a coagulant added thereto to adjust the pH of the mixed dispersion to an acidic pH (e.g., pH2 or more and 5 or less), and if necessary, a dispersion stabilizer may be added thereto and then heated.

Examples of the aggregating agent include surfactants having a polarity opposite to that of the surfactant contained in the mixed dispersion, for example, inorganic metal salts and metal complexes having a valence of 2 or more. When the metal complex is used as a coagulant, the amount of the coagulant used is reduced, and the charging characteristics are improved.

An additive that forms a complex or a similar bond with the metal ion of the agglutinating agent may also be used together with the agglutinating agent. As such an additive, a chelating agent is suitably used.

Examples of the inorganic metal salt include: metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide; and the like.

as the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids (オ キ シ カ ル ボ ン acid) such as tartaric acid, citric acid, and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA); and the like.

The amount of the chelating agent added is, for example, preferably 0.01 to 5.0 parts by mass, more preferably 0.1 to less than 3.0 parts by mass, based on 100 parts by mass of the resin particles.

Fusion coagulation step-

Then, the aggregated particle dispersion liquid in which the aggregated particles are dispersed is heated, for example, to a temperature higher than the glass transition temperature of the resin particles (for example, a temperature higher by 10 ℃ to 30 ℃ than the glass transition temperature of the resin particles) to fuse and coagulate the aggregated particles, forming toner particles.

Through the above steps, toner particles are obtained.

The toner particles can also be produced by: a step of, after obtaining an aggregated particle dispersion liquid in which aggregated particles are dispersed, further mixing the aggregated particle dispersion liquid with a resin particle dispersion liquid in which resin particles are dispersed to perform aggregation in such a manner that the resin particles further adhere to the surfaces of the aggregated particles, thereby forming 2 nd aggregated particles; and a step of heating the 2 nd aggregated particle dispersion liquid in which the 2 nd aggregated particle is dispersed to fuse and coagulate the 2 nd aggregated particle to form a core-shell structured toner particle.

After the completion of the coalescence step, the toner particles formed in the solution are subjected to a known cleaning step, a solid-liquid separation step, and a drying step to obtain toner particles in a dry state.

In the cleaning step, the substitution washing with ion-exchanged water can be sufficiently performed from the viewpoint of charging property. The solid-liquid separation step is not particularly limited, but may be performed by suction filtration, pressure filtration or the like from the viewpoint of productivity. In addition, the method of the drying step is also not particularly limited, but from the viewpoint of productivity, freeze drying, flash drying, fluidized bed drying, vibrated fluidized bed drying, and the like may be performed.

In addition, the toner in the embodiment of the present invention is prepared, for example, by adding an external additive to toner particles in a dry state and mixing. For example, mixing can be performed with a V-blender, Henschel mixer, Loedige mixer, or the like. In addition, coarse particles in the toner may be removed by a vibration sieve, a wind sieve, or the like as necessary. < Electrostatic image developer >

The electrostatic image developer according to an embodiment of the present invention contains at least the toner according to an embodiment of the present invention. The electrostatic image developer according to the embodiment of the present invention may be a one-component developer containing only the toner according to the embodiment of the present invention, or may be a two-component developer obtained by mixing the toner with a carrier.

The carrier is not particularly limited, and known carriers can be used. Examples of the carrier include: a coated carrier in which a surface of a core material made of magnetic powder is coated with a resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; a resin-impregnated carrier in which a porous magnetic powder is impregnated with a resin; and the like. The magnetic powder dispersion type carrier and the resin-impregnated type carrier may be those in which constituent particles of the carrier are a core material and a resin is coated on the surface thereof.

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

As the conductive particles, there can be mentioned: metals such as gold, silver, and copper; particles of carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, potassium titanate, and the like; and the like.

Examples of the coating resin and the 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 copolymer, linear silicone resin containing an organosiloxane bond or a modified product thereof, fluororesin, polyester, polycarbonate, phenol resin, epoxy resin, and the like. The coating resin and the matrix resin may contain an additive such as a conductive material.

When the surface of the core material is coated with a resin, a method of coating with a coating layer forming solution in which a coating resin and various additives (if necessary) are dissolved in an appropriate solvent, and the like can be cited. The solvent is not particularly limited, and may be selected according to the kind of the resin to be used, coating suitability, and the like. Specific examples of the resin coating method include: an immersion method in which the core material is immersed in a coating layer forming solution; a spray method of spraying the coating layer forming solution onto the surface of the core material; a fluidized bed method in which a solution for forming a coating layer is sprayed by flowing air while the core material is in a floating state; a kneader coating method in which the core material of the carrier and the coating layer-forming solution are mixed in a kneader coater and then the solvent is removed; and the like.

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

< image Forming apparatus/image Forming method >

The following explains an image forming apparatus and an image forming method according to an embodiment of the present invention.

An image forming apparatus of an embodiment of the present invention has: an image holding body; a charging member that charges a surface of the image holding body; an electrostatic image forming member for forming an electrostatic image on a surface of the charged image holding body; a developing member that contains an electrostatic image developer and develops an electrostatic image formed on a surface of the image holding body into a toner image by the electrostatic image developer; a transfer member that transfers the toner image formed on the surface of the image holding member to the surface of a recording medium; and a fixing member that fixes the toner image transferred onto the surface of the recording medium. In addition, as the electrostatic image developer, the electrostatic image developer according to the embodiment of the present invention is used.

In the image forming apparatus according to the embodiment of the present invention, an image forming method (an image forming method according to the embodiment of the present invention) including the steps of: a charging step of charging a surface of the image holding body; an electrostatic image forming step of forming an electrostatic image on the surface of the charged image holding body; a developing step of developing the electrostatic image formed on the surface of the image holding body into a toner image with the electrostatic image developer of the embodiment of the present invention; a transfer step of transferring the toner image formed on the surface of the image holder onto the surface of a recording medium; and a fixing step of fixing the toner image transferred onto the surface of the recording medium.

The image forming apparatus of the embodiment of the present invention employs the following known image forming apparatuses: a direct transfer type device that directly transfers a toner image formed on a surface of an image holder onto a recording medium; an intermediate transfer system device that primarily transfers a toner image formed on a surface of an image holding member onto a surface of an intermediate transfer member and secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto a surface of a recording medium; a device having a cleaning member that cleans the surface of the image holding body before charging after the toner image is transferred; a device having a charge removing member that irradiates a surface of the image holding body with charge removing light to remove charge before charging after the toner image is transferred; and the like.

In the case where the image forming apparatus according to the embodiment of the present invention is an intermediate transfer type apparatus, the transfer member (for example) adopts a configuration having: an intermediate transfer member having a toner image transferred on a surface thereof; a primary transfer member that primarily transfers a toner image formed on a surface of an image holder onto a surface of an intermediate transfer member; and a secondary transfer member that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto a surface of a recording medium.

in the image forming apparatus of the embodiment of the present invention, for example, the portion including the developing member may be a cartridge structure (process cartridge) detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge containing the electrostatic image developer according to the embodiment of the present invention and having a developing member is preferably used.

An example of an image forming apparatus according to an embodiment of the present invention will be described below, but is not limited thereto. In the following description, main portions shown in the drawings are described, and descriptions of other portions are omitted.

fig. 1 is a schematic view showing the configuration of an image forming apparatus according to an embodiment of the present invention, which is a view showing an image forming apparatus of a 5-line series system with an intermediate transfer system.

The image forming apparatus shown in fig. 1 has 1 st to 5 th image forming units 10V, 10Y, 10M, 10C, and 10K (image forming means) in such a manner as to output respective color images of vermilion (V), yellow (Y), magenta (M), cyan (C), and black (K), respectively, according to color-separated image data. These image forming units (hereinafter sometimes simply referred to as "units") 10V, 10Y, 10M, 10C, and 10K are arranged side by side at predetermined distance intervals in the horizontal direction. These units 10V, 10Y, 10M, 10C, and 10K may be process cartridges detachable from the image forming apparatus.

Below each of the units 10V, 10Y, 10M, 10C, and 10K, an intermediate transfer belt (an example of an intermediate transfer body) 20 is extended through each unit. The intermediate transfer belt 20 is wound around a drive roller 22, a support roller 23, and a counter roller 24 that are in contact with the inner surface of the intermediate transfer belt 20, and runs in a direction from the first unit 10V toward the fifth unit 10K. On the image holding surface side of the intermediate transfer belt 20, an intermediate transfer member cleaning device 21 is disposed opposite to the driving roller 22.

The respective toners of vermilion, yellow, magenta, cyan, and black accommodated in the toner cartridges 8V, 8Y, 8M, 8C, and 8K are supplied to the developing devices (examples of developing means) 4V, 4Y, 4M, 4C, and 4K of the respective units 10V, 10Y, 10M, 10C, and 10K, respectively.

Since the 1 st to 5 th units 10V, 10Y, 10M, 10C, and 10K have the same configuration, operation, and action, description is made here with the first unit 10V for forming a vermilion image disposed on the upstream side in the running direction of the intermediate transfer belt as a representative.

The first unit 10V has a photoconductor 1V serving as an image holder. The photoreceptor 1V is provided with: a charging roller (an example of a charging member) 2V that charges the surface of the photoreceptor 1V to a predetermined potential; an exposure device (an example of an electrostatic image forming means) 3V that forms an electrostatic image by exposing the charged surface with a laser beam based on color-separated image signals; a developing device (one example of a developing member) 4V that supplies toner onto the electrostatic image to develop the electrostatic image; a primary transfer roller (an example of a primary transfer member) 5V that transfers the developed toner image onto the intermediate transfer belt 20; and a photoreceptor cleaning device (an example of a cleaning member) 6V that removes toner remaining on the surface of the photoreceptor 1V after the primary transfer.

The primary transfer roller 5V is disposed inside the intermediate transfer belt 20 and at a position opposing the photoconductor 1V. Bias power supplies (not shown) for applying primary transfer biases are connected to the primary transfer rollers 5V, 5Y, 5M, 5C, and 5K of the respective units, respectively. The bias power source changes the transfer bias applied to each primary transfer roller by the control of an unillustrated control section.

the operation of forming a vermilion image in the first unit 10V will be described below.

first, the surface of the photoreceptor 1V is charged to a potential of-600V to-800V by the charging roller 2V before the start of the operation.

The photoreceptor 1V is formed by laminating a photosensitive layer on a conductive substrate (for example, having a volume resistivity at 20 ℃ of 1X 10-6. omega. cm or less). The photosensitive layer is generally high in resistance (resistance of common resins), but has such properties that: when irradiated with a laser beam, the specific resistance of the portion irradiated with the laser beam changes. Therefore, a laser beam is irradiated from the exposure device 3V onto the surface of the charged photoreceptor 1V according to the image data for vermilion sent from the control unit not shown in the figure. Thereby, an electrostatic image of a vermilion image pattern is formed on the surface of the photoreceptor 1V.

The electrostatic image is an image formed on the surface of the photoreceptor 1V by charging, which is a so-called negative latent image formed by: the laser beam from the exposure device 3V lowers the specific resistance of the irradiated portion of the photosensitive layer, and the charged charges on the surface of the photoreceptor 1V flow, while the charges of the portion not irradiated with the laser beam remain.

As the photoreceptor 1V operates, the electrostatic image formed on the photoreceptor 1V is rotated to a predetermined development position. Then, at the development position, the electrostatic image on the photoconductor body 1V is developed as a toner image by the developing device 4V to be visualized.

The developing device 4V contains, for example, an electrostatic image developer containing at least the toner and the carrier according to the embodiment of the present invention. The toner according to the embodiment of the present invention is frictionally charged by stirring it inside the developing device 4V, and has a charge of the same polarity (negative polarity) as that of the charge carried on the photoreceptor 1V, and is held on a developer roller (an example of a developer holding member). Then, by passing the surface of the photoreceptor 1V through the developing device 4V, the toner according to the embodiment of the present invention is electrostatically attached to the charge-removed latent image portion on the surface of the photoreceptor 1V, and the latent image is developed by the toner. The photoreceptor 1V on which the vermilion toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1V is conveyed to a predetermined primary transfer position.

When the vermilion toner image on the photoconductor 1V is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5V, an electrostatic force from the photoconductor 1V toward the primary transfer roller 5V acts on the toner image, and thereby the toner image on the photoconductor 1V is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is of a polarity (+) opposite to the toner polarity (-) and is controlled to, for example, +10 μ a in the first unit 10V by a control portion (not shown).

On the other hand, the toner remaining on the photoreceptor 1V is removed and recovered by the photoreceptor cleaning device 6V.

The primary transfer biases applied to the primary transfer rollers 5Y, 5M, 5C, and 5K subsequent to the second unit 10Y are controlled similarly to the first unit.

In this way, the intermediate transfer belt 20 on which the vermilion toner image is transferred in the first unit 10V is sequentially conveyed through the 2 nd to 5 th units 10Y, 10M, 10C, and 10K, whereby the toner images of the respective colors are superimposed to be transferred a plurality of times.

The intermediate transfer belt 20, on which 5-color toner images have been transferred a plurality of times by the 1 st to 5 th units, reaches a secondary transfer portion constituted by the intermediate transfer belt 20, a counter roller 24 in contact with an inner surface of the intermediate transfer belt, and a secondary transfer roller (an example of a secondary transfer member) 26 disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, by the feeding mechanism, a recording paper (one example of a recording medium) P is fed into a gap where the secondary transfer roller 26 is in contact with the intermediate transfer belt 20 at a predetermined timing, and a secondary transfer bias is applied to the counter roller 24. The transfer bias applied at this time is the same (-) polarity as the polarity (-) of the toner, and thus the electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, thereby transferring the toner image on the intermediate transfer belt 20 onto the recording paper P. Note that the secondary transfer bias at this time is determined based on the resistance detected by a resistance detecting member (not shown) for detecting the resistance of the secondary transfer portion, and the voltage is controlled.

Thereafter, the recording paper P is fed to a pressure contact portion (nip portion) between a pair of fixing rollers in a fixing device (an example of a fixing member) 28, and the toner image is fixed onto the recording paper P, thereby forming a fixed image.

As the recording paper P for transferring the toner image, plain paper used in an electrophotographic copying machine, a printer, and the like can be cited, for example. As the recording medium, an OHP sheet or the like may be mentioned in addition to the recording sheet P.

In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is preferably smooth, and for example, a copperplate paper obtained by coating the surface of plain paper with a resin or the like, an art paper for printing, or the like is suitably used.

The recording paper P after the fixing of the color image is completed is conveyed to the discharge section, thereby completing a series of color image forming operations.

< Process Cartridge/toner Cartridge >

A process cartridge according to an embodiment of the present invention will be explained.

The process cartridge according to the embodiment of the present invention is provided with a developing member which contains the electrostatic image developer according to the embodiment of the present invention and develops an electrostatic image formed on a surface of an image holding body into a toner image by using the electrostatic image developer, and is detachable from an image forming apparatus.

The process cartridge of the embodiment of the present invention is not limited to the above configuration, and may also be a configuration in which: the developing device and at least one of other components selected from, for example, an image holding member, a charging member, an electrostatic image forming member, and a transfer member as needed are provided.

The following shows an example of a process cartridge of an embodiment of the present invention, however, it is not limited thereto. In the following description, main portions shown in the drawings are described, and descriptions of other portions are omitted.

Fig. 2 is a schematic view showing the configuration of a process cartridge according to an embodiment of the present invention.

The process cartridge 200 shown in fig. 2 is integrally held by a housing 117 provided with a mounting rail 116 and an exposure opening 118 (for example): the photosensitive body 107 (an example of an image holder), a charging roller 108 (an example of a charging member) provided around the photosensitive body 107, a developing device 111 (an example of a developing member), and a photosensitive body cleaning device 113 (an example of a cleaning member) are formed in a box shape.

In fig. 2, 109 denotes an exposure device (an example of an electrostatic image forming member), 112 denotes a transfer device (an example of a transfer member), 115 denotes a fixing device (an example of a fixing member), and 300 denotes a recording sheet (an example of a recording medium).

Next, a toner cartridge of an embodiment of the present invention will be described.

The toner cartridge of the embodiment of the present invention is a toner cartridge that contains the toner of the embodiment of the present invention and is detachable from an image forming apparatus. The toner cartridge contains a supply toner for supplying to a developing part mounted in the image forming apparatus.

The image forming apparatus shown in fig. 1 is an image forming apparatus having a configuration in which toner cartridges 8V, 8Y, 8M, 8C, and 8K are detachable therefrom, and developing devices 4V, 4Y, 4M, 4C, and 4K are connected to the toner cartridges corresponding to the respective colors through toner supply pipes not shown in the drawing. In addition, when the toner contained in the toner cartridge becomes low, the toner cartridge can be replaced.

[ examples ]

The present invention will be described more specifically by way of examples hereinafter, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.

Hereinafter, "parts" are by mass unless otherwise specified.

The volume average particle diameter of each particle prepared in the following examples and toner particles was measured by the following method.

The particle diameter is 2 μm or more

measurement samples: the aqueous solution of sodium dodecylbenzenesulfonate (surfactant) 5 mass% in 2mL is added with particles of 0.5mg to 50mg, and the mixture is added to an electrolyte (ISOTON-II, product of Beckman Coulter) of 100mL to 150mL and dispersed in an ultrasonic disperser for 1 minute.

A measurement device: coulter Multisizer II (manufactured by Beckman Coulter Co., Ltd.) had a pore diameter of 100. mu.m.

50,000 particles of 2 μm to 60 μm were measured by using the above measurement sample and the above measurement apparatus, and the volume average particle size distribution was determined from the particle size distribution.

For the particle size range (channel) divided based on the particle size distribution, the volume cumulative distribution is plotted from the small diameter side, and the particle size at the cumulative percentage of 50% is taken as the volume average particle size.

The particle diameter of less than 2 μm-

Measurement samples: ion-exchanged water was added to the particle dispersion to adjust the solid content to about 10 mass%.

A measurement device: a laser diffraction type particle size distribution measuring instrument (LS 13320 manufactured by Beckman Coulter).

The measurement sample is put into a sample cell until a suitable concentration is reached, and measurement is performed when the scattering intensity reaches a sufficient value. For the particle size range (channel) divided based on the obtained particle size distribution, the volume cumulative distribution is drawn from the small diameter side, and the particle size at the cumulative percentage of 50% is taken as the volume average particle size.

< preparation of lutein Dispersion liquid >

[ preparation of astaxanthin Dispersion ]

200 parts of astaxanthin (ASTOTS-S manufactured by Wuta paper products, Ltd., astaxanthin concentration: 20%)

2 parts of an anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

200 parts of ion-exchanged water

The above materials were mixed and heated to 100 ℃ and dispersed by a homogenizer (Ultra Turrax T50, IKA) and then dispersed by a Menton-Gaulin high pressure homogenizer (Gaulin) to obtain an astaxanthin dispersion (astaxanthin content: 10% by mass). The volume average particle diameter of the particles in the dispersion was 150 nm.

[ preparation of canthaxanthin dispersion ]

Canthaxanthin (Canthaxanthin 20% LF, 20% Canthaxanthin concentration) 200 parts by weight

2 parts of an anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

200 parts of ion-exchanged water

The above materials were mixed and heated to 100 ℃ and dispersed by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation) and then dispersed by a Menton-Gaulin high pressure homogenizer (manufactured by Gaulin corporation) to obtain a canthaxanthin dispersion (canthaxanthin amount 10 mass%). The volume average particle diameter of the particles in the dispersion was 150 nm.

[ preparation of lutein Dispersion ]

Lutein (Lutein 20% LF from Divis Nutraceuticals, Lutein concentration 20%)

200 portions of

2 parts of an anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

200 parts of ion-exchanged water

The above materials were mixed and heated to 100 ℃ and dispersed by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation) and then dispersed by a Menton-Gaulin high pressure homogenizer (manufactured by Gaulin corporation) to obtain a lutein dispersion (10% by mass of lutein). The volume average particle diameter of the particles in the dispersion was 150 nm.

< preparation of Dispersion of bilirubins >

[ preparation of lycopene Dispersion ]

222 parts of lycopene (18 parts of lycopene prepared by synergistic fermentation Bio, the lycopene concentration is 18%)

2 parts of an anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

178 parts of ion-exchanged water

The above materials were mixed and heated to 100 ℃ and dispersed by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation) and then dispersed by a Menton-Gaulin high pressure homogenizer (manufactured by Gaulin corporation) to obtain a lycopene dispersion (10% by mass of lycopene). The volume average particle diameter of the particles in the dispersion was 150 nm.

[ preparation of beta-Phytoserine Dispersion ]

182 parts of Beta-Carotene (Beta-Carotene 22% LF, Beta-Carotene concentration 22% from Divis Nutraceuticals)

2 parts of an anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

218 parts of ion-exchanged water

The above materials were mixed and heated to 100 ℃ and dispersed by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation) and then dispersed by a Menton-Gaulin high pressure homogenizer (manufactured by Gaulin corporation) to obtain a β -lycopene dispersion (β -lycopene content 10 mass%). The volume average particle diameter of the particles in the dispersion was 150 nm.

< example 1>

[ preparation of resin particle Dispersion (1) ]

Polyester resin (1) (ethylene oxide adduct of terephthalic acid/fumaric acid/bisphenol a/propylene oxide adduct of bisphenol a ═ 30 mol/70 mol/5 mol/95 mol, weight average molecular weight 18,000, glass transition temperature 60 ℃) 160 parts by weight

233 parts of ethyl acetate

0.1 part of 0.3N aqueous sodium hydroxide solution

The above materials were put in a separable flask, heated at 70 ℃ and stirred by a stirrer (three-in-one motor manufactured by new eastern science corporation) to prepare a mixed solution. While stirring the mixture, 373 parts of ion-exchanged water was gradually added to emulsify the mixture in a phase inversion, and then the solvent was removed to obtain a resin particle dispersion (1) (solid content concentration 30 mass%). The volume average particle diameter of the resin particles in the dispersion was 180 nm.

[ preparation of anti-tackiness agent Dispersion (1) ]

100 parts of paraffin wax (HNP-9, manufactured by Japan wax Kogyo Co., Ltd.)

1 part of anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

350 parts of ion-exchanged water

The above materials were mixed and heated to 100 ℃ and dispersed by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation) and then dispersed by a Menton-Gaulin high pressure homogenizer (manufactured by Gaulin corporation) to obtain an anti-tackiness agent dispersion liquid (1) (solid content: 20 mass%). The volume average particle diameter of the releasing agent particles in the dispersion liquid was 200 nm.

[ preparation of toner particles ]

The above-mentioned material was put in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and 30 parts of an aqueous solution of nitric acid having a polyaluminum chloride concentration of 10 mass% was added. Then, the mixture was dispersed at 30 ℃ by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation), and then heated to 45 ℃ in a heating oil bath and held for 30 minutes. Then, 96.7 parts of resin particle dispersion (1) was added slowly and held for 1 hour, and a 0.1N aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, followed by heating to 85 ℃ with continued stirring and holding for 5 hours. Then, the resultant was cooled to 20 ℃ at a rate of 20 ℃ per minute, filtered, washed thoroughly with ion-exchanged water, and dried to obtain toner particles having a volume average particle diameter of 7.4. mu.m.

[ preparation of externally-added toner ]

100 parts of the toner particles and 0.7 part of the silica particles treated with dimethylsilicone oil (RY 200, manufactured by AEROSIL corporation, Japan) were mixed by a Henschel mixer to obtain a toner.

[ preparation of developer ]

The above components except for the ferrite particles were dispersed with a sand mill to prepare a dispersion, and the dispersion was put into a vacuum degassing type kneader together with the ferrite particles, and dried under reduced pressure with stirring, thereby obtaining a support.

A developer was obtained by mixing 5 parts of a toner with 100 parts of the above carrier.

< examples 2 to 40>

An externally added toner and a developer were prepared in the same manner as in example 1, except that the kind and the mixing ratio of the materials were changed in such a manner that the content of the colorant was as in table 1 or table 2, thereby preparing toner particles.

< example 41>

[ preparation of toner particles ]

The above materials were kneaded with an extruder, pulverized with a pulverizer of a surface pulverizing type, and then classified into fine particles and coarse particles with a wind power classifier, thereby obtaining toner particles having a volume average particle diameter of 7.5 μm.

Using the above toner particles, an externally added toner and a developer were prepared in the same manner as in example 1.

< example 42>

[ preparation of toner particles ]

The above materials were kneaded with an extruder, pulverized with a pulverizer of a surface pulverizing type, and then classified into fine particles and coarse particles with a wind power classifier, thereby obtaining toner particles having a volume average particle diameter of 7.5 μm.

using the above toner particles, an externally added toner and a developer were prepared in the same manner as in example 1.

< example 43>

[ preparation of pigment Dispersion (1) ]

70 parts of pigment yellow 180 (NovopermYellowp-HG manufactured by Clariant Co., Ltd.)

1 part of anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

200 parts of ion-exchanged water

The above materials were mixed and dispersed for 10 minutes by a homogenizer (Ultra Turrax T50, IKA). Ion-exchanged water was added so that the solid content in the dispersion was 20% by mass, to obtain a pigment dispersion (1) in which particles having a volume average particle diameter of 190nm were dispersed.

[ preparation of toner particles ]

The above-mentioned material was put in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and 30 parts of an aqueous solution of nitric acid having a polyaluminum chloride concentration of 10 mass% was added. Then, the mixture was dispersed at 30 ℃ by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation), and then heated to 45 ℃ in a heating oil bath and held for 30 minutes. Then, 94.7 parts of resin particle dispersion (1) was added slowly and held for 1 hour, and a 0.1N aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, followed by heating to 85 ℃ with continued stirring and holding for 5 hours. Then, the resultant was cooled to 20 ℃ at a rate of 20 ℃ per minute, filtered, washed thoroughly with ion-exchanged water, and dried to obtain toner particles having a volume average particle diameter of 7.3 μm.

Using the above toner particles, an externally added toner and a developer were prepared in the same manner as in example 1.

< example 44>

[ preparation of pigment Dispersion (2) ]

70 parts of pigment Red 122 (FASTOGEN Super Magenta RTS, DIC Co., Ltd.)

1 part of anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

200 parts of ion-exchanged water

The above materials were mixed and dispersed for 10 minutes by a homogenizer (Ultra Turrax T50, IKA). Ion-exchanged water was added so that the solid content in the dispersion was 20% by mass, to obtain a pigment dispersion (2) in which particles having a volume average particle diameter of 120nm were dispersed.

[ preparation of toner particles ]

The above-mentioned material was put in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and 30 parts of an aqueous solution of nitric acid having a polyaluminum chloride concentration of 10 mass% was added. Then, the mixture was dispersed at 30 ℃ by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation), and then heated to 45 ℃ in a heating oil bath and held for 30 minutes. Then, 95.1 parts of resin particle dispersion (1) was added slowly and held for 1 hour, and a 0.1N aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, followed by heating to 85 ℃ with continued stirring and holding for 5 hours. Then, the resultant was cooled to 20 ℃ at a rate of 20 ℃ per minute, filtered, washed thoroughly with ion-exchanged water, and dried to obtain toner particles having a volume average particle diameter of 7.5 μm.

Using the above toner particles, an externally added toner and a developer were prepared in the same manner as in example 1.

< example 45>

[ preparation of resin particle Dispersion (2) ]

Styrene-acrylic resin (1) (styrene/n-butyl acrylate/β -carboxyethyl acrylate/1, 10-decanediol diacrylate: 310 parts/100 parts/9 parts/1.5 parts (input amount during polymerization), weight average molecular weight 33,000, glass transition temperature 53 ℃) 160 parts

233 parts of ethyl acetate

0.1 part of 0.3N aqueous sodium hydroxide solution

The above materials were put in a separable flask, heated at 70 ℃ and stirred by a stirrer (three-in-one motor manufactured by new eastern science corporation) to prepare a mixed solution. While stirring the mixture, 373 parts of ion-exchanged water was gradually added to emulsify the mixture in a phase inversion, and then the solvent was removed to obtain a resin particle dispersion (2) (solid content concentration 30 mass%). The volume average particle diameter of the resin particles in the dispersion was 180 nm.

[ preparation of toner particles ]

The above-mentioned material was put in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and 30 parts of an aqueous solution of nitric acid having a polyaluminum chloride concentration of 10 mass% was added. Then, the mixture was dispersed at 30 ℃ by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation), and then heated to 45 ℃ in a heating oil bath and held for 30 minutes. Then, 96.7 parts of resin particle dispersion (2) was added slowly and held for 1 hour, and a 0.1N aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, followed by heating to 85 ℃ with continued stirring and holding for 5 hours. Then, the resultant was cooled to 20 ℃ at a rate of 20 ℃ per minute, filtered, washed thoroughly with ion-exchanged water, and dried to obtain toner particles having a volume average particle diameter of 7.4. mu.m.

Using the above toner particles, an externally added toner and a developer were prepared in the same manner as in example 1.

< comparative examples 1 to 7>

an externally added toner and a developer were prepared in the same manner as in example 1, except that the kind and the mixing ratio of the materials were changed in such a manner that the content of the colorant was as shown in table 3, thereby preparing toner particles.

< comparative example 8>

[ preparation of toner particles ]

The above-mentioned material was put in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and 30 parts of an aqueous solution of nitric acid having a polyaluminum chloride concentration of 10 mass% was added. Then, the mixture was dispersed at 30 ℃ by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation), and then heated to 45 ℃ in a heating oil bath and held for 30 minutes. Then, 96.3 parts of resin particle dispersion (1) was added slowly and held for 1 hour, and a 0.1N aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, followed by heating to 85 ℃ with continued stirring and holding for 5 hours. Then, the resultant was cooled to 20 ℃ at a rate of 20 ℃ per minute, filtered, washed thoroughly with ion-exchanged water, and dried to obtain toner particles having a volume average particle diameter of 7.5 μm.

Using the above toner particles, an externally added toner and a developer were prepared in the same manner as in example 1.

< comparative example 9>

[ preparation of fluorescent pigment Dispersion (1) ]

70 parts of a fluorescent pigment (SF-5013 Red manufactured by シ ン ロ イ ヒ Co.)

1 part of anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

200 parts of ion-exchanged water

the above materials were mixed and dispersed for 10 minutes by a homogenizer (Ultra Turrax T50, IKA). Ion-exchanged water was added so that the solid content in the dispersion was 20% by mass, to obtain a fluorescent pigment dispersion (1) in which particles having a volume average particle diameter of 130nm were dispersed.

[ preparation of fluorescent pigment Dispersion (2) ]

The dispersion was carried out in the same manner as in the fluorescent pigment dispersion (1) except that the fluorescent pigment was changed to SF-5014 Orange (manufactured by シ ン ロ イ ヒ Co., Ltd.), to thereby obtain a fluorescent pigment dispersion (2) in which particles having a volume average particle diameter of 130nm were dispersed.

[ preparation of toner particles ]

The above-mentioned material was put in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and 30 parts of an aqueous solution of nitric acid having a polyaluminum chloride concentration of 10 mass% was added. Then, the mixture was dispersed at 30 ℃ by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation), and then heated to 45 ℃ in a heating oil bath and held for 30 minutes. Then, 97.9 parts of resin particle dispersion (1) was added slowly and held for 1 hour, and a 0.1N aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, followed by heating to 85 ℃ with continued stirring and holding for 5 hours. Then, the resultant was cooled to 20 ℃ at a rate of 20 ℃ per minute, filtered, washed thoroughly with ion-exchanged water, and dried to obtain toner particles having a volume average particle diameter of 7.7 μm.

Using the above toner particles, an externally added toner and a developer were prepared in the same manner as in example 1.

< comparative example 10>

[ preparation of pigment Dispersion (3) ]

70 parts of pigment Red 48:1 (Fuji Red K manufactured by Fuji pigment Co., Ltd.)

1 part of anionic surfactant (Neogenin RK, first Industrial pharmaceutical Co., Ltd.)

200 parts of ion-exchanged water

The above materials were mixed and dispersed for 10 minutes by a homogenizer (Ultra Turrax T50, IKA). Ion-exchanged water was added so that the solid content in the dispersion was 20% by mass, to obtain a pigment dispersion (3) in which particles having a volume average particle diameter of 70nm were dispersed.

[ preparation of toner particles ]

The above-mentioned material was put in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and 30 parts of an aqueous solution of nitric acid having a polyaluminum chloride concentration of 10 mass% was added. Then, the mixture was dispersed at 30 ℃ by a homogenizer (Ultra Turrax T50 manufactured by IKA corporation), and then heated to 45 ℃ in a heating oil bath and held for 30 minutes. Then, 96.4 parts of resin particle dispersion (1) was added slowly and held for 1 hour, and a 0.1N aqueous solution of sodium hydroxide was added to adjust the pH to 8.5, followed by heating to 85 ℃ with continued stirring and holding for 5 hours. Then, the resultant was cooled to 20 ℃ at a rate of 20 ℃ per minute, filtered, washed thoroughly with ion-exchanged water, and dried to obtain toner particles having a volume average particle diameter of 7.3 μm.

Using the above toner particles, an externally added toner and a developer were prepared in the same manner as in example 1.

< evaluation >

[ color reproducibility ]

The following procedures, imaging, and measurement were all performed at a temperature of 25 deg.C/humidity of 60%.

as an image forming apparatus for forming an image for evaluation, a DocuCentre Color 400CP manufactured by fuji schle co was prepared, and the developers of the examples and comparative examples were charged into a developing device, and the toner was charged into a toner cartridge. Then, an image (5 cm. times.5 cm in size, 4.8g/m2 in toner amount) having a monochrome density of 100% was formed on paper (J paper manufactured by Fuji-Skel corporation, ISO whiteness 89%).

The mean values of L, a and b values were calculated at 10 arbitrary locations on CIE1976L a b color system of the formed image using X-Rite939 (pore diameter 4mm) from X-Rite.

Then, the color difference Δ E between the formed image and the vermillion index (panonce Warm Red C) is calculated based on the following formula, and the color reproducibility is determined according to the following criterion. The results are shown in tables 1 to 3.

[ mathematical formula 1]

L1, a1, b1 are the L, a, b values of the vermilion index, L1 ═ 59, a1 ═ 69, and b1 ═ 51. L2, a2, b2 are the L, a, b values of the formed image.

-a criterion-

AA: delta E is less than 4

A: delta E is 4 or more and less than 7

B: delta E is 7 or more and less than 10

C: delta E is 10 or more and less than 15

D: delta E is 15 or more

Wherein, the range up to C is an allowable range.

[ light resistance ]

An image formed under the same conditions as described above was irradiated with ultraviolet rays (illuminance 99k lux) for 240 hours in an environment of 25 ℃ (± 5 ℃) and 50% humidity using a weather resistance acceleration tester (Ci 4000, ATLAS co.). The color difference Δ E of the image before and after the ultraviolet irradiation was calculated, and the light resistance was determined according to the following criteria. The results are shown in tables 1 to 3.

-a criterion-

AA: delta E is less than 5

A: delta E is 5 or more and less than 10

B: delta E is 10 or more and less than 15

C: delta E is 15 or more and less than 20

D: delta E is not less than 20 and less than 25

E: delta E of 25 or more and less than 30

F: delta E of 30 or more and less than 40

g: delta E is 40 or more

Wherein, the range up to F is an allowable range.

Claims (18)

1. A toner for developing an electrostatic image, comprising toner particles, wherein the toner particles contain a binder resin, a xanthophyll compound and a xanthophyll compound,

The content of the xanthophylls in the toner particles is 0.2 to 15 mass%,

The content of the bilirubin in the toner particles is 0.2 mass% or more and 15 mass% or less.

2. The electrostatic image developing toner according to claim 1, wherein a total amount of the xanthophylls and the xanthophylls is 0.5% by mass or more and 20% by mass or less of the toner particles.

3. The electrostatic image developing toner according to claim 1, wherein a mass ratio of the xanthophylls to the xanthophylls contained in the toner particles is: the xanthophyll/xanthophyll is 0.5-3.0.

4. The electrostatic image developing toner according to claim 1, wherein the xanthophyll compound is astaxanthin and the xanthophyll compound is lycopene.

5. The electrostatic image developing toner according to claim 4, wherein a mass ratio of the astaxanthin based substance to the lycopene based substance contained in the toner particles is: the astaxanthin and lycopene are 0.5-3.0.

6. The electrostatic image developing toner according to claim 4, wherein a total amount of the xanthophylls and the xanthophylls is 30% by mass or more of a total amount of the colorant in the toner particles.

7. The electrostatic image developing toner according to claim 1, wherein the toner particles contain a white pigment.

8. The electrostatic image developing toner according to claim 7, wherein the white pigment is at least one selected from the group consisting of silica, titania, and alumina.

9. The electrostatic image developing toner according to claim 5, wherein a total amount of the xanthophylls, and the white pigment accounts for 85% by mass or more of a total amount of the colorant in the toner particles.

10. The electrostatic image developing toner according to claim 1, wherein the binder resin contains a polyester resin.

11. The electrostatic image developing toner according to claim 10, wherein the polyester resin has a weight average molecular weight Mw of 5,000 or more and 1,000,000 or less.

12. The electrostatic image developing toner according to claim 10, wherein the polyester resin has a molecular weight distribution Mw/Mn of 1.5 or more and 100 or less.

13. The electrostatic image developing toner according to claim 1, wherein the toner particles contain a releasing agent having a melting temperature of 50 ℃ or higher and 110 ℃ or lower.

14. The electrostatic image developing toner according to claim 13, wherein a content of the releasing agent in the toner particles is 1% by mass or more and 20% by mass or less.

15. The electrostatic image developing toner according to claim 1, wherein the toner particles have a shape factor SF1 of 110 to 150.

16. An electrostatic image developer comprising the toner for developing an electrostatic image according to claim 1.

17. The electrostatic image developer according to claim 16, which contains a carrier, and the carrier is a resin-coated carrier containing carbon black.

18. A toner cartridge containing the electrostatic image developing toner according to claim 1 and being detachable from an image forming apparatus.