JP4742987B2 - Toner for electrophotography and image forming method - Google Patents

Description

  The present invention relates to an electrophotographic toner and an image forming method using the electrophotographic toner.

The electrophotographic method generally forms an electrostatic latent image of an electrostatic charge on a photoconductor containing a photoconductive substance by various means, and then develops the latent image as a powder image with toner and applies it to paper as necessary. After transferring the powder image, the powder image is fixed by heating, pressing, or solvent vapor. (See U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, etc.)
In recent years, an electrostatic latent image of an original is formed by exposure with spectral light, and this is developed with each color toner to obtain a colored copy image, or each color copy image is superimposed to obtain a full color copy image. A color copying method for obtaining the above has been put into practical use, and color toners of yellow, magenta, cyan, etc., in which pigments and / or dyes of various colors are dispersed in a binder resin, have been produced as color toners used for this.

  Conventionally known organic pigments and dyes have been used as colorants used in electrophotographic toners, but each has various drawbacks. For example, organic pigments are generally superior in heat resistance and light resistance compared to dyes. However, since they exist in the form of particles dispersed in the toner, the hiding power is increased and the transparency is lowered. Further, since the dispersibility of the pigment is generally poor, the transparency is impaired, the saturation is lowered, and the color reproducibility of the image is hindered.

  In addition, in order to make it possible to visually confirm the color of the toner in the lowermost layer, the lowermost toner in the color-superposed toner is not hidden by the upper layer, and is fixed. In addition, the transparency of the toner is required, and in order to maintain the color reproducibility of the original, the dispersibility of the colorant and the coloring power are required.

  As a method of eliminating the disadvantages of the pigment, for example, by using a flushing method as a pigment dispersion method, the transparency of the pigment is improved by achieving a pigment dispersion diameter on the order of submicron with primary particles without aggregated secondary particles. Means for improving the charging property, fixing property and image uniformity by coating the pigment particles with a binder resin and an outer shell resin (Japanese Patent Laid-Open No. 11-160914). No. gazette) has been proposed. However, even in the case of outputting with the toner proposed in these cases, it is still difficult to obtain sufficient transparency in the case of the toner using pigment.

  In color image forming apparatuses, in principle, all color reproduction can be performed by subtractive color mixing using the three primary colors of yellow, magenta, and cyan. However, in reality, the spectrum when a pigment is dispersed in a thermoplastic resin is used. The range of color reproducibility and saturation are reduced by the color mixing characteristics when toners of different colors are superimposed on each other, so there are still many issues remaining to faithfully reproduce the color of the document. Yes.

  On the other hand, a toner using a dye (see Patent Document 1) and a toner in which a dye and a pigment are mixed (see Patent Document 2) are publicly disclosed. Since it exists in a dissolved state in the resin, it has excellent transparency and saturation, but has the disadvantage that its light resistance and heat resistance are greatly inferior to those of pigments.

  Concerning heat resistance, in addition to the decrease in density due to the decomposition of the dye, when the toner image is fixed with a heat roller, the dye tends to sublime and cause contamination inside the machine, and the dye dissolves in the silicone oil used for fixing. In the end, however, there is a problem of causing an offset phenomenon by fusing to a heating roll. As a proposal for eliminating these disadvantages of dyes, for example, means for achieving both light resistance, sublimation and color reproducibility by using a specific anthraquinone dye or chelate dye as magenta toner (see Patent Documents 3 and 4) And an encapsulated toner in which a core containing a polymer resin and a color dye is coated with a polymer has been proposed (see Patent Document 5).

However, even in the case of outputting with the toners proposed in these cases, it is still difficult to obtain sufficient heat resistance (sublimation) and light resistance in the case of toners using dyes. Many of these have safety problems (nickel and cobalt), and development of toners that satisfy these conditions is desired.
JP-A-5-11504 JP-A-5-34980 JP-A-8-69128 Japanese Patent Laid-Open No. 10-20559 Japanese Patent Laid-Open No. 5-72792

  The object of the present invention has been made to solve the above-mentioned problems, enables favorable coloring of thermoplastic resins, excellent light resistance, transparency and color reproducibility, and excellent charging properties. Another object of the present invention is to provide an electrophotographic toner and an image forming method.

  The object of the present invention is achieved by the following configurations.

1. In the electrophotographic toner containing a dye as a coloring component, the dye is a metal chelate dye containing a compound represented by the following general formula (1) and a copper compound having an enolate anion as at least one ligand. An electrophotographic toner characterized by the above.

(.A wherein _{R 1} represents an aromatic carbocyclic or aromatic heterocyclic, _{Z 1} is -N =, _{Z 2} is -C _(R 2) = represents, _{R 2} is representing a hydrogen atom or a substituent ₁ represents a monocyclic 5- to 6-membered aromatic carbocyclic ring or aromatic heterocyclic ring, and these aromatic carbocyclic ring or aromatic heterocyclic ring may further have a substituent.
2. _2. The electrophotographic toner according to 1 above, wherein in the general formula (1) , R ₂ is a 5- or 6-membered aromatic carbocyclic ring or aromatic heterocyclic ring.

3 . 3. The electrophotographic apparatus as described in 1 or 2 above, wherein the thermoplastic resin contains a metal chelate dye having at least one ligand of the compound represented by the general formula (1) as a solid dispersion. toner.

4 . In step and at least includes an image forming method step of transferring onto a transfer material a toner image formed by development for developing an electrostatic image formed on an electrostatic image bearing member with toner, any of the 1-3 as the toner An image forming method using the electrophotographic toner according to claim 1.

  That is, as a result of intensive studies to solve the above problems, the present inventors have found that the metal chelate dye has a compound having a specific structure represented by the general formula (1) as at least one ligand. An electrophotographic toner containing a coloring component, and with these constitutions, an electrophotographic toner and an image forming method exhibiting excellent color reproducibility, transparency, chargeability and particularly excellent light resistance can be obtained. I found it.

  The electrophotographic toner and the image forming method according to the present invention enable good coloring of a thermoplastic resin, have excellent light resistance, transparency, color reproducibility, and excellent charging properties.

  Hereinafter, the present invention will be described in detail.

  First, the compound represented by the general formula (1) will be described.

In the general formula (1), R ₁ represents an aromatic carbocyclic ring or an aromatic heterocyclic ring.
Specific examples of the aromatic carbocycle or aromatic heterocycle represented by R ₁ include, for example, a benzene ring, naphthalene ring, pyridine ring, pyrazole ring, imidazole ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, Thiazole ring, isothiazole ring, thiadiazole, oxazole ring, isoxazole ring, oxadiazole ring, triazole ring, tetrazole ring, quinoline ring, isoquinoline ring, benzothiazole ring, benzoisothiazole ring, benzoxazole ring, benzoisoxazole ring Benzopyrazole ring, benzimidazole ring and the like. Preferred are a benzene ring, a pyridine ring, a thiazole ring, an imidazole ring, a thiophene ring, and a furan ring, and most preferred is a benzene ring.

These rings may have a halogen atom and a substituent, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, a chlorine atom is preferable.
The substituent represented by R ₁ is not particularly limited, and examples thereof include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group). Group, dodecyl group, trifluoromethyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), aromatic carbocyclic group (eg, phenyl group, naphthyl group, etc.), acylamino group (eg, acetylamino group) , Benzoylamino group, etc.), alkylthio group (eg, methylthio group, ethylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkenyl group (eg, 2-propenyl group, 3-butenyl group, 1- Methyl-3-propenyl group, 3-pentenyl group, 1-methyl-3-butenyl group, 4-hexenyl group Group, cyclohexenyl group, etc.), halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom etc.), alkynyl group (eg propargyl group etc.), heterocyclic group (eg pyridyl group, thiazolyl group, oxazolyl group, Imidazolyl group etc.), alkylsulfonyl group (eg methylsulfonyl group, ethylsulfonyl group etc.), arylsulfonyl group (eg phenylsulfonyl group, naphthylsulfonyl group etc.), alkylsulfinyl group (eg methylsulfinyl group etc.), aryl Sulfinyl group (eg, phenylsulfinyl group), phosphono group, acyl group (acetyl group, pivaloyl group, benzoyl group, etc.), carbamoyl group (eg, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, butylaminocarbonyl) Group, cyclohexylaminocarbonyl group, phenylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexyl) Aminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), sulfonamide groups (for example, methanesulfonamide group, benzenesulfonamide group, etc.), cyano Group, alkoxy group (for example, methoxy group, ethoxy group, propoxy group, etc.), aryloxy group (for example, phenoxy group, naphthyloxy group, etc.), heterocyclic oxy group Siloxy group, acyloxy group (eg, acetyloxy group, benzoyloxy group, etc.), sulfonic acid group, sulfonic acid salt, aminocarbonyloxy group, amino group (eg, amino group, ethylamino group, dimethylamino group, butylamino) Group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, etc.), anilino group (for example, phenylamino group, chlorophenylamino group, toluidino group, anisidino group, naphthylamino group, 2-pyridylamino group, etc.), imide group Ureido groups (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), alkoxycarbonyl Amino group (for example, methoxycarbonylamino group, benzenesulfonamide group, etc.), alkoxycarbonyl group (for example, methoxycarbonyl group, ethoxycarbonyl group, phenoxycarbonyl, etc.), aryloxycarbonyl group (for example, phenoxycarbonyl group, etc.), heterocyclic ring Examples thereof include thio group, thioureido group, carboxyl group, carboxylic acid salt, hydroxyl group, mercapto group, nitro group and the like.

  As the substituent, an alkyl group, an alkoxy group, an amino group, an acylamino group, a carbamoyl group, an acyloxy group, and an alkoxycarbonyl group are preferable, and an alkyl group and an alkoxy group are more preferable.

Z ₁ is -N =, _{Z 2} is -C _(R 2) = represents, _{R 2} represents a hydrogen atom or a substituent. Examples of the substituent represented by R ₂ include the same groups as the substituent that R ₁ can substitute, and may be further substituted with the same substituent.

R ₂ is, for example, preferably an alkyl group, a cycloalkyl group, an aromatic carbocyclic group, an alkenyl group and a heterocyclic group, more preferably an aromatic carbocyclic group, an alkyl group or a heterocyclic group, most preferably an aromatic group. A carbocyclic group and a heterocyclic group;

  As aromatic carbocyclic group and heterocyclic group, for example, benzene ring, naphthalene ring, pyridine ring, pyrazole ring, imidazole ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, thiazole ring, isothiazole ring, thiadiazole, oxazole Ring, isoxazole ring, oxadiazole ring, triazole ring, tetrazole ring, quinoline ring, isoquinoline ring, benzothiazole ring, benzoisothiazole ring, benzoxazole ring, benzoisoxazole ring, benzopyrazole ring, benzimidazole ring, etc. Among them, preferred are a benzene ring, a pyridine ring, a thiazole ring, an imidazole ring, a thiophene ring and a furan ring, and most preferred is a benzene ring.

Further, in the general formula (1), _{Z 1} is -N =, _{Z 2} is -C _(R 2) is =.

In the general formula (1), A ₁ represents a monocyclic 5 to 6-membered aromatic carbocycle or aromatic heterocycle, and these aromatic carbocycle or aromatic heterocycle further has a substituent. It may be.

Specific examples of the aromatic carbocycle and aromatic heterocycle include, for example, benzene ring, pyridine ring, pyrazole ring, imidazole ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, thiazole ring, isothiazole ring, thiadiazole, oxazole. And a ring, an isoxazole ring, an oxadiazole ring, a triazole ring, a tetrazole ring, a quinoline ring, an isoquinoline ring, a thiophene ring, and a furan ring. A benzene ring, a pyridine ring, a thiophene ring, a furan ring and a thiazole ring are preferred, and a thiophene ring is most preferred. These rings may have a substituent, and examples of the substituent include the same groups as R ₁ described above, preferably an amino group, and most preferably a dialkylamino group.

In order for the general formula (1) to be a ligand of a metal chelate dye, it is preferable that at least one of R ₁ , A ₁ and R ₂ has a chelatable group, and among them, R ₂ is a chelatable group. More preferably, it has. Examples of the chelatable group include a hydroxyl group, an alkoxy group, an aryloxy group, a mercapto group, an alkylthio group, an arylthio group, an amino group, an anilino group, an alkoxycarbonyl group, an acyloxy group, a sulfamoyl group, a sulfonamido group, a carbamoyl group, Examples thereof include amide groups, carboxy groups, and heterocyclic groups.

An alkoxy group, an amino group, a heterocyclic group, and a sulfonamide group are preferable, and an alkoxy group is most preferable. Examples of heterocyclic groups that can be chelated include imidazole ring, pyrazole ring, isothiazole ring, isoxazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, quinoline ring, isoquinoline ring, quinazolone ring, benzothiazole. Ring, benzoxazole ring, benzimidazole ring, tetrahydroquinoline ring, chroman ring, thiochroman ring, benzoquinazolone ring, benzothiadiazine ring and the like. Of these, a pyridine ring and a pyrazine ring are preferable. These heterocyclic groups may have a substituent, and examples of the substituent include the same groups as the substituent that R ₁ can be substituted, and may be further substituted with the same substituent. .

  The metal chelate dye having the compound represented by the general formula (1) as at least one ligand is preferably represented by the following general formula (2).

In the general formula (2), M represents a metal ion, L represents an anion, m represents an integer of 1 to 3, and n represents an integer of 0 to 3. _{R 1, Z 1, Z 2} , A 1 has the same meaning as _{R 1, Z 1, Z 2} , A 1 in the general formula (1).

  In the general formula (2), the metal ion represented by M is selected from metal atoms of Group VIII, Group Ib, Group IIb, Group IIIa, Group IVa, Group Va, Group VIa, Group VIIa, preferably 2 It is a valent transition metal ion. Specific examples include divalent metal ions of Ni, Cu, Co, Cr, Zn, Fe, Pd, and Pt, more preferably divalent metal ions of Cu, Co, and Zn, and particularly preferably. It is a divalent metal ion of Cu.

In the present invention, in order to obtain a metal chelate dye represented by the general formula (2), a metal-containing compound represented by M (L) n and a compound represented by the general formula (1), It can be obtained by dissolving and mixing in a solution. In the general formula (2), examples of the anion represented by L include enolate (acetylacetonate, hexafluoroacetylacetonate), halogen ion (fluoride, Chloride, bromide, iodide, etc.), hydroxide ion, sulfite ion, sulfate ion, alkylsulfonate ion, arylsulfonate ion, nitrate ion, nitrite ion, carbonate ion, perchlorate ion, alkylcarboxylate ion, arylcarboxyl acid ion, tetraalkyl borate, Sarishineto, _{benzoate, PF 6 -, BF 4 -} , bF ₆ - and others as mentioned, is preferably a enolate anion, and most preferably enolate anion represented by the following general formula (3).

In the general formula (3), E ₁ and E ₂ each represent an electron-withdrawing group having a Hammett's substituent constant (σp value) of 0.1 or more and 0.9 or less, and R ₅ represents an alkyl group, an aryl group, or a heterocyclic ring. Represents a group, an alkoxy group, or an amino group, and may have a substituent.

A substituent having a σp value represented by E ₁ and E ₂ of 0.1 or more and 0.9 or less will be described. As the value of Hammett's substituent constant σp here, Hansch, C .; It is preferable to use the values described in the report of Leo et al. (For example, J. Med. Chem. 16, 1207 (1973); ibid. 20, 304 (1977)).

For example, as a substituent or atom having a value of σp of 0.10 or more, a chlorine atom, a bromine atom, an iodine atom, a carboxyl group, a cyano group, a nitro group, a halogen-substituted alkyl group (for example, trichloromethyl, trifluoromethyl, Chloromethyl, trifluoromethylthiomethyl, trifluoromethanesulfonylmethyl, perfluorobutyl), aliphatic / aromatic or heterocyclic acyl groups (eg formyl, acetyl, benzoyl), aliphatic / aromatic or heterocyclic sulfonyl groups (eg , Trifluoromethanesulfonyl, methanesulfonyl, benzenesulfonyl), a carbamoyl group (eg, carbamoyl, methylcarbamoyl, phenylcarbamoyl, 2-chlorophenylcarbamoyl), an alkoxycarbonyl group (eg, methoxycarbonyl, Xyloxycarbonyl, diphenylmethylcarbonyl), substituted aromatic groups (eg, pentachlorophenyl, pentafluorophenyl, 2,4-dimethanesulfonylphenyl, 2-trifluoromethylphenyl), heterocyclic residues (eg, 2-benzooxa Zolyl, 2-benzthiazolyl, 1-phenyl-2-benzimidazolyl, 1-tetrazolyl), azo group (eg, phenylazo), ditrifluoromethylamino group, trifluoromethoxy group, alkylsulfonyloxy group (eg, methanesulfonyloxy) ), Acyloxy groups (eg acetyloxy, benzoyloxy), arylsulfonyloxy groups (eg benzenesulfonyloxy), phosphoryl groups (eg dimethoxyphosphonyl, diphenylphosphoryl), sulfamoyl groups (eg For example, N-ethylsulfamoyl, N, N-dipropylsulfamoyl, N- (2-dodecyloxyethyl) sulfamoyl, N-ethyl-N-dodecylsulfamoyl, N, N-diethylsulfamoyl) Is mentioned.

  Examples of the substituent having a σp value of 0.35 or more include a cyano group, a nitro group, a carboxyl group, a fluorine-substituted alkyl group (for example, trifluoromethyl, perfluorobutyl), an aliphatic / aromatic or heterocyclic acyl group. (Eg, acetyl, benzoyl, formyl), aliphatic / aromatic or heterocyclic sulfonyl groups (eg, trifluoromethanesulfonyl, methanesulfonyl, benzenesulfonyl), carbamoyl groups (eg, carbamoyl, methylcarbamoyl, phenylcarbamoyl, 2-chloro) -Phenylcarbamoyl), alkoxycarbonyl group (eg methoxycarbonyl, ethoxycarbonyl, diphenylmethylcarbonyl), fluorine or sulfonyl group substituted aromatic group (eg pentafluorophenyl, 2,4-dimethanesulfonyl) Phenyl), heterocyclic residues (eg 1-tetrazolyl), azo groups (eg phenylazo), alkylsulfonyloxy groups (eg methanesulfonyloxy), phosphoryl groups (eg dimethoxyphosphoryl, diphenylphosphoryl), sulfamoyl groups, etc. Is mentioned.

  Examples of the substituent having a value of σp of 0.60 or more include a cyano group, a nitro group, an aliphatic / aromatic or heterocyclic sulfonyl group (for example, trifluoromethanesulfonyl, difluoromethanesulfonyl, methanesulfonyl, benzenesulfonyl) and the like. It is done.

E ₁ and E ₂ are preferably a halogenated alkyl group (particularly a fluorine-substituted alkyl group), a carbonyl group, a cyano group, an alkoxycarbonyl group, an alkylsulfonyl group, an alkylsulfonyloxy group, and the like. Preferable substituents for R include an alkyl group, an alkoxy group, and an amino group, and more preferably an alkyl group or an alkoxy group.

  Specific examples of the enolate anion are shown below, but the present invention is not limited thereto.

  Hereinafter, although the specific example of a compound represented by the said General formula (1) is shown, this invention is not limited by the following specific examples.

  Examples of the compound represented by the general formula (1) according to the present invention include, for example, JP-A Nos. 10-265690 and 6-250357, JP-A No. 64-63194, JP-A No. 2-208094, Conventional methods described in JP-A-3-205189, JP-A-2-265911, JP-A-2-310087, JP-A-4-91987, JP-A-4-13774, JP-A-3-275767, etc. The metal chelate dye that can be synthesized with reference to the compound represented by the general formula (1) as a ligand is referred to a conventionally known method described in JP-A No. 2000-191934. Can be synthesized.

  Specific examples of the metal chelate dye represented by the general formula (2) according to the present invention are shown below, but the present invention is not limited to the following specific examples.

Specific examples of the method for synthesizing the dye ligand according to the present invention represented by the general formula (1) and the metal chelate dye represented by the general formula (2) are shown below. Can be synthesized in the same manner, and the synthesis method is not limited thereto.
[Synthesis Example 1]
(Synthesis of D-83)

To an intermediate 1: 1.10 g and an intermediate 2: 1.45 g, toluene: 50 ml and piperidine: 0.51 g are added with stirring, heated to reflux, and reacted for 4 hours while dehydrating through an ester tube. After completion of the reaction, the reaction solution was concentrated, purified by column chromatography, and recrystallized from acetonitrile to obtain D-83: 1.92 g. The product was identified by MASS, ¹ H-NMR, and IR spectrum, and confirmed to be the target product.

[Synthesis Example 2]
(Synthesis of D-29)

Intermediate 3: 1.76 g, Intermediate 2: 1.45 g, toluene: 50 ml and piperidine: 0.51 g are added with stirring, heated to reflux, and reacted for 4 hours while dehydrating through an ester tube. After completion of the reaction, the reaction solution was concentrated, purified by column chromatography, and recrystallized from acetonitrile to obtain D-29: 2.21 g. The product was identified by MASS, ¹ H-NMR, and IR spectrum, and confirmed to be the target product.

[Synthesis Example 3]
(Synthesis of D-30)

Intermediate 3: 1.76 g and Intermediate 4: 1.60 g are added with toluene: 50 ml and piperidine: 0.51 g with stirring, heated to reflux, and reacted for 4 hours while dehydrating through an ester tube. After completion of the reaction, the reaction solution was concentrated, purified by column chromatography, and recrystallized from acetonitrile to obtain D-30: 2.13 g. The product was identified by MASS, ¹ H-NMR, and IR spectrum, and confirmed to be the target product.

[Synthesis Example 4]
(Synthesis of D-84)

To an intermediate of 1.10 g and an intermediate of 5: 1.35 g, toluene: 50 ml and piperidine: 0.51 g are added with stirring, heated to reflux, and reacted for 4 hours while dehydrating through an ester tube. After completion of the reaction, the reaction solution was concentrated, purified by column chromatography, and recrystallized from acetonitrile to obtain D-84: 1.96 g. The product was identified by MASS, ¹ H-NMR, and IR spectrum, and confirmed to be the target product.

  The metal chelate dye used in the toner of the present invention is preferably an oil-soluble dye. The oil-soluble dye is usually soluble in water and soluble in an organic solvent having no water-soluble group such as carboxylic acid or sulfonic acid. Although it is an insoluble dye, in the present invention, a dye that exhibits oil solubility by forming a water-soluble dye with a long-chain base is also included. When the metal chelate dye is an oil-soluble dye, the dye is added at a stage where a solid dispersion of the dye is prepared by drying in liquid and contained in the toner, or the emulsion polymer is aggregated with a flocculant. The toner can be produced using various methods such as adding a color to the toner and adding a dye at the stage of polymerizing the monomer and polymerizing the toner.

  Further, when the compatibility between the thermoplastic resin and the dye in the toner is sufficient, the dye diffuses in the thermoplastic resin and a colored portion having a size larger than the original particle size of the dye particles ( Dye cloud) is formed in the thermoplastic resin, so that it is considered that the transparency of the single color of the toner and the transparency in the superposition are also improved.

  The metal chelate compound having the compound represented by the general formula (1) used in the electrophotographic toner of the present invention as a ligand may be used alone or in a different structure. You may mix and use multiple types.

  In addition, a metal chelate having a ligand represented by the compound represented by the general formula (1) in the present invention as a dye that can be used in a conventional electrophotographic toner within a range that does not affect the effects of the present invention. You may use together with dye.

(Description of dye dispersion)
The electrophotographic toner of the present invention preferably contains a metal chelate dye having a compound represented by the general formula (1) as at least one ligand as a solid dispersion in a thermoplastic resin. In order to contain the metal chelate dye in the resin as a solid dispersion, for example, the metal chelate dye alone or the metal chelate dye and the resin are dissolved (or dispersed) in a water-immiscible organic solvent such as ethyl acetate or toluene. ), And after emulsifying and dispersing in water, the colored fine particle dispersion obtained by a submerged drying method for removing the organic solvent can be obtained by agglomerating with a (thermoplastic) latex resin. Although the emulsifying disperser is not limited, for example, an ultrasonic disperser, a high-speed stirring disperser or the like is used.

  The solid dispersion of the metal chelate dye is preferably a small particle having a particle size of 10 nm to 100 nm, and more preferably a small particle having a particle size of 10 nm to 80 nm. When the solid dispersion has a small particle size and monodispersion, light scattering is suppressed, and concealing particles that block light can be eliminated. With these effects, the transparency of the single color of the toner is improved, and it is possible to greatly improve the saturation with respect to the amount of attached dye.

On the other hand, a colored fine particle dispersion obtained by mixing a dye solid with a surfactant and atomizing with a medium type stirrer can be obtained by agglomerating with a (thermoplastic) latex resin.
A solid dispersion obtained by a submerged drying method has a shape close to a sphere, and is more preferable because it has improved adhesion to a binder and can suppress interfacial scattering.

  The colored fine particle dispersion referred to in the present invention may be fine particles consisting of only a colored component, or a colored component and a surfactant, or a colored component and a surfactant, as long as it contains a dye as a colored component. And fine particles containing resin, and other additives. By simultaneously using a resin and an additive in addition to a dye as a coloring component, colored fine particles having various performances can be obtained.

  Further, when the colored fine particles as shown in FIG. 1 are coated with an outer shell resin (shell), for example, a resin dissolved in an organic solvent is gradually dropped into the colored fine particles, and the resin is added simultaneously with the precipitation. By adsorbing to the core surface, colored fine particles having a core-shell structure can be obtained. Alternatively, for example, an aqueous dispersion of resin fine particles is formed in advance by emulsion polymerization, an organic solvent solution in which a dye is dissolved is mixed with the aqueous dispersion of resin fine particles, and the resin fine particles are impregnated with the dye afterwards. It can be obtained by various methods such as a method of forming a shell using colored fine particles as a core.

  In the present invention, the core-shell structure means a form in which two or more kinds of resins or dyes having different compositions are present in phase separation in the particles. Therefore, the shell portion may not only cover the core portion completely, but may cover a portion of the core portion. Further, a part of the resin forming the shell may form a domain or the like in the core particle. Furthermore, it may have a multilayer structure of three or more layers including another layer having a different composition in the middle between the core part and the shell part.

(Surfactant)
In emulsifying the metal chelate dye, a normal anionic emulsifier (surfactant) and / or a nonionic emulsifier (surfactant) can be used as necessary.

  Examples of the normal nonionic emulsifier include, for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether, polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonylphenyl ether, and sorbitan monolaurate. Sorbitan higher fatty acid esters such as sorbitan monostearate and sorbitan trioleate, polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene monolaurate, polyoxyethylene monostearate, etc. Higher fatty acid esters of glycerin such as polyoxyethylene higher fatty acid esters, oleic acid monoglyceride, stearic acid monoglyceride Class, polyoxyethylene - polyoxypropylene - and the like block copolymer.

  Examples of the usual anionic emulsifier include higher fatty acid salts such as sodium oleate, alkylaryl sulfonates such as sodium dodecylbenzene sulfonate, alkyl sulfates such as sodium lauryl sulfate, polyethoxyethylene lauryl ether sulfate. Polyoxyethylene alkyl ether sulfates such as sodium, polyoxyethylene alkyl aryl ether sulfates such as sodium polyoxyethylene nonylphenyl ether sulfate, sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene lauryl sulfosuccinate And alkylsulfosuccinic acid ester salts, and derivatives thereof.

  The metal chelate dye in the electrophotographic toner of the present invention is preferably a small particle having a particle size of 10 nm to 100 nm. Light scattering is suppressed and the light is blocked by the small particle size and monodispersion. It is possible to eliminate the concealing particles.

  Further, in the present invention, migration is suppressed when the dye is not in a molecular state but in a solid state in which some particles are aggregated. There is no worry of sublimation or oil contamination.

(Thermoplastic latex resin)
The thermoplastic latex resin is preferably a metal chelate dye or a thermoplastic resin that has high adhesion to colored fine particles, and is particularly preferably a solvent-soluble one. Further, if the polymer precursor is soluble in a solvent, a curable resin that forms a three-dimensional structure can also be used. As the thermoplastic resin, those generally used as a binder resin for a toner are used without particular limitation. For example, styrene resins, acrylic resins such as alkyl acrylates and alkyl methacrylates, and styrene acrylic copolymer resins. Polyester resin, silicon resin, olefin resin, amide resin, epoxy resin, etc. are preferably used, but in order to improve transparency and color reproducibility of superimposed images, transparency is high and melting characteristics are high. Resins with low viscosity and high sharp melt properties are required. As the thermoplastic resin having such characteristics, a styrene resin, an acrylic resin, and a polyester resin are suitable.

  The number average molecular weight (Mn) is 3000 to 6000, preferably 3500 to 5500, and the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 6, preferably 2.5 to 5. 5. It is desirable to use a resin having a glass transition point of 50 to 70 ° C., preferably 55 to 70 ° C. and a softening temperature of 90 to 110 ° C., preferably 90 to 105 ° C.

  If the number average molecular weight of the thermoplastic resin is less than 3000, the image portion is peeled off when a full-color solid image is folded, resulting in an image defect (bending fixability is deteriorated). And the fixing strength decreases.

  If Mw / Mn is less than 2, high temperature offset is likely to occur. If Mw / Mn is greater than 6, sharp melt characteristics at the time of fixing deteriorate, and the translucency of toner and color mixing at the time of full color image formation decrease. End up. Further, if the glass transition point is lower than 50 ° C., the heat resistance of the toner becomes insufficient, and toner aggregation tends to occur during storage. Color mixing at the time of image formation is reduced. Further, when the softening temperature is lower than 90 ° C., high temperature offset tends to occur. When the softening temperature is higher than 110 ° C., fixing strength, translucency, color mixing property, and gloss of a full color image are deteriorated.

(toner)
In the electrophotographic toner of the present invention, a metal chelate dye having at least one ligand of the above-described thermoplastic latex resin and the compound represented by the general formula (1), or a color containing the metal chelate dye In addition to the fine particles, known charge control agents, offset preventive agents, and the like can be used. The charge control agent is not particularly limited.

  As the negative charge control agent used for the color toner, a colorless, white or light color charge control agent that does not adversely affect the color tone and translucency of the color toner can be used. For example, a zinc or chromium metal complex of a salicylic acid derivative, A calixarene compound, an organic boron compound, a fluorine-containing quaternary ammonium salt compound or the like is preferably used. Examples of the salicylic acid metal complex include those described in JP-A Nos. 53-127726 and 62-145255, and examples of calixarene compounds include those described in JP-A No. 2-201378. However, as the organic boron compound, for example, those described in JP-A-2-221967 can be used, and as the organic boron compound, for example, those described in JP-A-3-1162 can be used. When such a charge control agent is used, it is desirable to use 0.1 to 10 parts by mass, preferably 0.5 to 5.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin (binder resin).

  There are no particular restrictions on the anti-offset agent. For example, polyethylene wax, oxidized polyethylene wax, polypropylene wax, oxidized polypropylene wax, carnauba wax, sazol wax, rice wax, candelilla wax, jojoba oil wax, honey Wax wax or the like can be used. The added amount of such wax is 0.5 to 5 parts by mass, preferably 1 to 3 parts by mass with respect to 100 parts by mass of the thermoplastic resin (binder resin). This is because if the addition amount is less than 0.5 parts by mass, the effect of the addition is insufficient, and if it exceeds 5 parts by mass, the translucency and color reproducibility deteriorate.

  The toner of the present invention uses the above-described thermoplastic resin (binder resin), a metal chelate dye having the compound represented by the general formula (1) as at least one ligand, and other desired additives, It can be produced by other known methods such as kneading / pulverization method, suspension polymerization method, emulsion polymerization method, emulsion dispersion granulation method, encapsulation method and the like.

  Among these production methods, the emulsion polymerization method is preferred from the viewpoints of production cost and production stability in consideration of the reduction in the toner particle size accompanying the increase in image quality.

  In the emulsion polymerization method, the thermoplastic resin emulsion produced by emulsion polymerization is mixed with a dispersion of toner particle components such as other colored fine particles, and the repulsive force of the particle surface generated by pH adjustment and the cohesive force due to the addition of an electrolyte are added. Toner particles are produced by slowly agglomerating while maintaining a balance, performing aggregation while controlling the particle size and particle size distribution, and simultaneously controlling the fusion and shape between the fine particles by heating and stirring. The toner particles of the present invention preferably have a volume average particle diameter of 4 to 10 μm, preferably 6 to 9 μm, from the viewpoint of high-definition image reproducibility.

  In the toner of the present invention, a post-treatment agent can be added and mixed from the viewpoint of imparting toner fluidity and improving cleaning properties, and is not particularly limited. Examples of such post-treatment agents include inorganic oxide fine particles such as silica fine particles, alumina fine particles, and titania fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, and strontium titanate and titanium. Inorganic titanate compound fine particles such as zinc oxide can be used, and it is possible to use single or different additives in combination. These fine particles are desirably used after being surface-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil, etc. from the viewpoints of environmental stability and heat-resistant storage stability. On the other hand, it is desirable to use 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass.

  The toner of the present invention can be used as a two-component developing toner used by mixing with a carrier, or as a one-component developing toner not using a carrier.

  As the carrier used in combination with the toner of the present invention, conventionally known carriers can be used as a carrier for two-component development. For example, a carrier made of magnetic particles such as iron or ferrite, such a magnetic material. A resin-coated carrier in which particles are coated with a resin, a binder-type carrier in which magnetic fine powder is dispersed in a binder resin, or the like can be used.

  Among these carriers, a silicone resin, a copolymer resin (graft resin) of an organopolysiloxane and a vinyl monomer, or a resin-coated carrier using a polyester resin can be used as a coating resin, such as toner spent. From the viewpoint, a carrier coated with a resin obtained by reacting an isocyanate with a copolymer resin of an organopolysiloxane and a vinyl monomer is particularly preferable from the viewpoint of durability, environmental stability, and spent resistance. . As the vinyl monomer, it is necessary to use a monomer having a substituent such as a hydroxyl group reactive with isocyanate. In addition, it is preferable to use a carrier having a volume average particle size of 20 to 100 μm, preferably 20 to 60 μm from the viewpoint of ensuring high image quality and preventing carrier fogging.

(Image forming method)
Next, an image forming method using the toner of the present invention will be described.

  In the present invention, the image forming method is not particularly limited. For example, a method of forming a plurality of images on a photosensitive member and transferring them in a batch, a method of sequentially transferring images formed on the photosensitive member to a transfer belt, etc. are not particularly limited, but more preferably a plurality of images on the photosensitive member. This image is formed and transferred at once.

  In this method, the photosensitive member is uniformly charged and exposed according to the first image, and then the first development is performed to form a first toner image on the photosensitive member.

  Next, the photosensitive member on which the first image is formed is uniformly charged, and exposure according to the second image is given, and second development is performed to form a second toner image on the photosensitive member.

  Further, the photosensitive member on which the first and second images are formed is uniformly charged, exposed according to the third image, and subjected to the third development to form a third toner image on the photosensitive member. .

  Further, the photosensitive member on which the first, second, and third images are formed is uniformly charged to give exposure according to the fourth image, and the fourth development is performed, and the fourth toner image is formed on the photosensitive member. To form.

  For example, a full color toner image is formed on the photosensitive member by developing the first time with yellow, the second time with magenta, the third time with cyan, and the fourth time with black toner.

  Thereafter, the image formed on the photoreceptor is collectively transferred to an image support such as paper, and further fixed on the image support to form an image.

  In this method, the images formed on the photoconductor are collectively transferred to paper or the like to form an image. Therefore, unlike the so-called intermediate transfer method, the number of times of transfer that causes image disturbance is one. The image quality can be improved by using only once.

As a method for developing on the photoreceptor, non-contact development is preferable because a plurality of developments are necessary. In addition, a method in which an alternating electric field is applied during development is also a preferable method.
Further, as described above, the non-contact development method is preferable as the development method for forming a superimposed color image on the image forming body and transferring it collectively.

  The volume average particle size of the carrier that can be used as the two-component developer is 15 to 100 μm, more preferably 25 to 60 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  The carrier is preferably further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in the resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene / acrylic resin, silicone resin, ester resin, or fluorine-containing polymer resin is used.

  The resin for constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. For example, styrene / acrylic resin, polyester resin, fluorine resin, phenol resin, etc. are used. Can do.

  A preferred fixing method used in the present invention is a so-called contact heating method. In particular, typical examples of the contact heating method include a heat roll fixing method and a pressure contact heating fixing method in which fixing is performed by a rotating pressure member including a heating element fixedly arranged.

(image)
In image formation in which development, transfer, and fixing are performed using the toner of the present invention, the state of transfer to fixing is such that the toner of the present invention transferred onto a transfer material is discolored even after fixing. Without being adhered to the surface of the paper in a state of being dispersed in the toner particles.

In the present invention, since the colored fine particles are dispersed in the toner particles as described above, the toner particles contain a high concentration of the dye, but the dye is not released to the surface of the toner particles (does not migrate). This is a problem of a toner in which a dye obtained by dispersing or dissolving a dye as it is in a thermoplastic resin (toner binder resin) as in the past is exposed on the surface of the toner particles.
1. Low charge,
2. Large difference in charge between high temperature and high humidity and low temperature and low humidity (environment-dependent)
3. For example, it is possible to eliminate the variation in the charge amount of each color toner when using pigments of cyan, magenta, yellow, and black as in the case of full color image recording.

  In addition, when heat-fixing to a transfer material, the dye as a colorant does not migrate out of the colored fine particles (exposed to the surface of the colored fine particles). There is no dye sublimation or oil contamination during fixing.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, the embodiment of this invention is not limited to these. In the text, “part” means “part by mass”.

<Production of toner>
Using the colorants shown in Table 1 below, toners were prepared using the toner production methods shown below.

(Manufacturing method 1)
Pulverization method 100 parts of a polyester resin, 8 parts of a colorant, and 3 parts of a polypropylene resin (Biscol 550P, manufactured by Sanyo Kasei) were mixed, kneaded, pulverized and classified to obtain a powder. Further, 100 parts of this powder and 1.0 part of silica fine particles R805 (particle size 12 nm, hydrophobization degree 60, manufactured by Nippon Aerosil Co., Ltd.) were mixed with a Henschel mixer to obtain a pulverized toner.

(Production Method 2) Polymerization Method 1- (Conventional Method)
20 g of a colorant is added to a solution obtained by dissolving 5 g of sodium dodecyl sulfate in 200 ml of pure water, and an aqueous dispersion of the colorant and a low molecular weight polypropylene (number average molecular weight = 3200) are obtained by applying stirring and ultrasonic waves. An emulsified dispersion was prepared by emulsifying in water with a surfactant so that the solid concentration was 30% by mass.

  60 g of low molecular weight polypropylene emulsified dispersion is mixed with the above colorant dispersion, 220 g of styrene, 40 g of n-butyl acrylate, 12 g of methacrylic acid, 5.4 g of t-dodecyl mercaptan as a chain transfer agent, 2000 ml of degassed pure water Then, the emulsion polymerization was carried out by maintaining at 70 ° C. for 3 hours while stirring under a nitrogen stream.

  To 1000 ml of the resulting dispersion of the colorant-containing resin fine particles, sodium hydroxide was added to adjust the pH to 7.0, and then 270 ml of a 2.7 mol% aqueous potassium chloride solution was added. Further, 160 ml of isopropyl alcohol and ethylene 9.0 g of polyoxyethylene octylphenyl ether having an average degree of polymerization of oxide of 10 was added after being dissolved in 67 ml of pure water, and the reaction was carried out by stirring for 6 hours while maintaining at 75 ° C. The obtained reaction liquid was filtered and washed with water, and further dried and crushed to obtain colored particles.

  The colored particles and silica fine particles R805 (particle size 12 nm, hydrophobicity 60, manufactured by Nippon Aerosil Co., Ltd.) 1.0 part were mixed with a Henschel mixer to obtain a polymerization method toner.

(Production Method 3) Polymerization Method 2
(Dye dispersion)
An interface in which 7.08 g of an anionic surfactant (sodium dodecylbenzenesulfonate: SDS) was previously dissolved in 2760 g of ion-exchanged water in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device. The activator solution (aqueous medium) was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. On the other hand, 72.0 g of a compound represented by the following as a release agent is added to a monomer mixture composed of 115.1 g of styrene, 42.0 g of n-butyl acrylate and 10.9 g of methacrylic acid, and heated to 80 ° C. A monomer solution was prepared by warming and dissolving. The monomer solution (80 ° C.) is mixed and dispersed in the surfactant solution (80 ° C.) by a mechanical disperser, and then the polymerization initiator (potassium persulfate: KPS) 0 is added to the dispersion. An initiator solution prepared by dissolving .84 g in 200 g of ion-exchanged water was added, and polymerization (first stage polymerization) was performed by heating and stirring at 80 ° C. for 3 hours to prepare a latex.

  Next, an initiator solution prepared by dissolving 7.73 g of a polymerization initiator (KPS) in 240 ml of ion exchange water was added to this latex, and after 15 minutes, at 80 ° C., 383.6 g of styrene and n-butyl acrylate 140 A monomer mixture composed of 0.0 g, methacrylic acid 36.4 g, and tert-dodecyl mercaptan 13.7 g was added dropwise over 126 minutes. After completion of dropping, the mixture was heated and stirred for 60 minutes to perform polymerization (second stage polymerization), and then cooled to 40 ° C. to obtain a latex.

  Next, 18.0 g of the colorant and 720.0 g of ethyl acetate were placed in a separable flask, the inside of the flask was replaced with nitrogen gas, and the mixture was stirred to completely dissolve the colorant. Next, 1200 g of an aqueous solution containing 5.94 g of E-27C was added dropwise and stirred, and then emulsified for 300 seconds using Clearmix W Motion CLM-0.8W (M Technique). Thereafter, ethyl acetate was removed under reduced pressure to obtain a dye dispersion.

  The dye dispersion obtained as described above, 1250 g of latex, and 2000 ml of ion-exchanged water were placed in a 5-liter four-necked flask equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device and stirred.

  After adjusting the internal temperature to 30 ° C., a 5 mol / L aqueous sodium hydroxide solution was added to this solution to adjust the pH to 10.0. Next, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, temperature increase was started, and the system was heated to 90 ° C. over 6 minutes (temperature increase rate = 10 ° C./min). In this state, the particle size of the associated particles was measured with “Coulter Counter TA-II”, and when the volume average particle size reached 6.5 μm, an aqueous solution in which 115 g of sodium chloride was dissolved in 700 ml of ion-exchanged water was added. Then, the particle growth was stopped, and the fusion was continued by heating and stirring at a liquid temperature of 90 ° C. ± 2 ° C. for 6 hours.

  Then, it cooled to 30 degreeC on the conditions of 6 degreeC / min. Then, the associated particles are filtered from the dispersion liquid of the associated particles, and after being redispersed in ion exchange water (pH = 3) in an amount 10 times the mass ratio of the entire associated particles, After the process of filtering the associated particles from the washing water was repeated twice, the washing treatment was performed only with ion-exchanged water and dried with hot air at 40 ° C. to obtain colored particles. The colored particles thus obtained were mixed with 1% by mass of hydrophobic silica (number average primary particle size = 12 nm, degree of hydrophobicity = 68), hydrophobic titanium oxide (number average primary particle size = 20 nm, degree of hydrophobicity = 63) After each addition at a ratio of 1.2% by mass, the mixture was mixed with a ferrite carrier having a volume average particle diameter of 60 μm coated with a silicone resin so that the concentration of the mixture was 6%, to obtain a polymerization method toner. .

<< Evaluation equipment and conditions >>
In each of the examples, each of the toners 1 to 10 obtained as described above was evaluated for actual photographs using a color copying machine (KL-2010: manufactured by Konica Corporation) as an image forming apparatus.

  As the fixing device, a commonly used heat roll fixing type was used. Specifically, a cylindrical (made of an inner diameter = 40 mm, wall thickness = 1.0 mm, total width = 310 mm) cored bar made of an aluminum alloy with a built-in heater in the center is coated with tetrafluoroethylene-perfluoroalkyl vinyl ether. A heating roller is formed by coating with a 120 μm thick tube of coalescence (PFA), and the surface of a cylindrical core made of iron (inner diameter = 40 mm, wall thickness = 2.0 mm) is made of sponge silicone rubber (Asker C The pressure roller was configured by coating with a hardness of 48 and a thickness of 2 mm, and the heating roller and the pressure roller were brought into contact with each other with a load of 150 N to form a 5.8 mm wide nip. Using this fixing device, the linear velocity of printing was set to 480 mm / sec. Note that a web type supply system impregnated with polydiphenyl silicone (having a viscosity of 10 Pa · s at 20 ° C.) was used as a cleaning mechanism of the fixing device. The fixing temperature was controlled by the surface temperature of the heating roller (set temperature 175 ° C.). The amount of silicone oil applied was 0.1 mg / A4.

<Evaluation items and methods>
In the test, a reflection image (an image on paper) and a transmission image (an OHP image) were prepared on the paper and the OHP, respectively, using the image forming apparatus described above with the developer using the color toner of the present invention. (1) Color gamut, (2) Transparency, (3) Chargeability, and (4) Light resistance were evaluated by the methods shown in (1). The toner adhesion amount was evaluated in the range of 0.7 ± 0.05 (mg / cm ² ).

(Characteristic evaluation)
(1) Color reproducibility The color reproducibility of a single color image on copy paper was evaluated according to the following evaluation criteria by visual evaluation using 10 monitors.

(Evaluation criteria)
A: Color reproducibility is particularly excellent.

  ○: Excellent color reproducibility.

  (Triangle | delta): Although there is some color contamination, it is a level which is satisfactory practically.

  ×: Color contamination is large and there is a problem in image quality.

(2) Transparency Concerning the transparency of the image, a transparent image (OHP image) was prepared, and for the fixed image, a reference is made to an OHP sheet on which toner is not supported by a “330 type automatic spectrophotometer” manufactured by Hitachi, Ltd. The visible spectral transmittance of the image was measured, the difference in spectral transmittance between 650 nm and 550 nm was determined, and the transparency of the OHP image was evaluated as follows. When this value is 70% or more, it can be determined that the film has good permeability.

(Evaluation criteria)
◎: 90% or more ○: 70% to less than 90% ×: less than 70% (3) Change in charge amount over time Qa is the charge amount when a developer is set and the first image is displayed, 1 million sheets The amount of charge when the image was taken was Qb, and the value of Qb / Qa was evaluated according to the following evaluation criteria.

(Evaluation criteria)
◎: 0.9 or more and less than 1.1 ○: 0.8 or more and less than 0.9, or 1.1 or more and less than 1.2 Δ: 0.7 or more and less than 0.8, or 1.2 or more and less than 1.3 X: Less than 0.7 or 1.3 or more (4) Light resistance A 7-day exposure test was performed using “Xenon Long Life Weather Meter” (Xenon Arc Lamp, 70000 Lux, 24.0 ° C.) manufactured by Suga Test Instruments Co., Ltd. Thereafter, the residual ratio of the dye with the image before the test was measured and compared with Macbeth Color-Eye7000.

(Evaluation criteria)
A: 90% or more B: 80% or more and less than 90% B: 70% or more and less than 80% X: less than 70% The results are shown in Table 2 below.

  As described above, according to the toners 1 to 10 of the present invention, excellent color reproducibility, transparency, and chargeability can be obtained, and a high-quality image with particularly excellent light resistance can be formed. .

The figure which represented typically the cross section of the colored fine particle of a core-shell structure formed by coat | covering an inside (core) with outer shell resin (shell).

Explanation of symbols

3 Colored fine particles 4 Resin 5 Dye 6 Inside (core)
7 Outer shell resin (shell)

Claims (4)

In the electrophotographic toner containing a dye as a coloring component, the dye is a metal chelate dye containing a compound represented by the following general formula (1) and a copper compound having an enolate anion as at least one ligand. An electrophotographic toner characterized by the above.

(.A wherein _{R 1} represents an aromatic carbocyclic or aromatic heterocyclic, _{Z 1} is -N =, _{Z 2} is -C _(R 2) = represents, _{R 2} is representing a hydrogen atom or a substituent ₁ represents a monocyclic 5- to 6-membered aromatic carbocyclic ring or aromatic heterocyclic ring, and these aromatic carbocyclic ring or aromatic heterocyclic ring may further have a substituent. _2. The electrophotographic toner according to claim 1, wherein in the general formula (1) , R ₂ is a 5- or 6-membered aromatic carbocyclic ring or aromatic heterocyclic ring. 3. The electrophotographic image according to claim 1, wherein a metal chelate dye having at least one ligand of the compound represented by the general formula (1) as a solid dispersion is contained in the thermoplastic resin. Toner. An image forming method comprising at least a step of developing an electrostatic charge image formed on an electrostatic image bearing member with toner and a step of transferring a toner image formed by development onto a transfer material. An image forming method comprising using the electrophotographic toner according to any one of the items .

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