JP2012133192A - Cyan toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide cyan toner that provides high reflection density to a printed material, as well as high fixing strength and glossiness.SOLUTION: Cyan toner contains a binder resin, a mold release agent, and cyan colorant. The cyan colorant contains pigment with a copper phthalocyanine derivative represented by the following formula (1) or the following formula (2).

Description

  The present invention relates to a cyan toner (hereinafter sometimes simply referred to as “toner”) used for developing an electrostatic latent image in an electrophotographic apparatus, an electrostatic recording method, an electrostatic printing method, or the like.

In an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus, an electrostatic latent image formed on a photoreceptor is first developed with toner. Next, the formed toner image is transferred onto a transfer material such as paper as necessary, and then fixed by various methods such as heating, pressurization, or solvent vapor.
In such image forming apparatuses, digital full-color copiers and digital full-color printers have been put into practical use. The digital full-color copying machine separates a color image original with blue, green and red filters, and then converts an electrostatic latent image having a dot diameter of 20 to 70 μm corresponding to the original color original into yellow, magenta, Development is performed using cyan and black toners, and a full-color image is formed using a subtractive color mixing effect.

In recent years, the demand for higher image quality and higher definition of this full-color image has been increasing. In particular, in order to improve color reproducibility, it is desired that printing can be performed with a hue equivalent to printing with ink.
Conventionally, as a colorant for cyan toner, an anthraquinone compound, a copper phthalocyanine compound and derivatives thereof are known, but in recent years, a cyan toner capable of obtaining a high printing density has been demanded from the viewpoint of low cost.

In Patent Document 1, when wet-grinding crude copper phthalocyanine, a salt of sulfonated copper phthalocyanine and an amine having an alkylene group having 10 or more carbon atoms is added to 1 to 20% of the crude copper phthalocyanine. A method for producing a copper phthalocyanine pigment is disclosed.
Patent Document 2 discloses a color toner containing, as a cyan colorant, an unsubstituted copper phthalocyanine pigment and a polyhalocopper phthalocyanine pigment having an average of 9 to 11 halogen atoms in one molecule.

Japanese Patent Laid-Open No. 7-53889 JP-A-11-160912

In paragraph [0001] of the specification of Patent Document 1, the pigment obtained by the method described in the document is used dispersed in a printing ink such as gravure ink or offset ink, or a vehicle such as paint. In some cases, the vehicle has a high fluidity and the resulting coating is glossy. However, as a result of studies by the present inventors, it has been found that the toner using the pigment described in Patent Document 1 as a cyan colorant in the binder resin still has insufficient print density.
Further, the toner disclosed in Patent Document 2 does not have sufficient fixing strength, and the gloss of the printed matter obtained tends to be low.
SUMMARY OF THE INVENTION An object of the present invention is to provide a cyan toner having a high reflection density of printed matter and a high fixing strength and gloss.

  As a result of intensive studies to solve the above problems, the present inventor has obtained a cyan toner containing a binder resin, a release agent and a cyan colorant, wherein the cyan colorant is a copper phthalocyanine derivative pigment having a specific structure. It has been found that the above-mentioned problems can be solved by using a cyan toner characterized by containing the cyan toner.

  That is, the cyan toner of the present invention is a cyan toner containing a binder resin, a release agent and a cyan colorant, and the cyan colorant is a copper phthalocyanine represented by the following formula (1) or the following formula (2). It contains a derivative pigment.

（上記式（１）及び式（２）中、ＣｕＰｃは銅フタロシアニン残基であり、ｎは１〜４の整数である。また、上記式（１）中、Ｒ^１及びＲ^２はそれぞれ独立に、水素原子及び炭素数１〜６のアルキル基からなる群より選ばれる原子又は基である。）

(In the above formulas (1) and (2), CuPc is a copper phthalocyanine residue, and n is an integer of 1 to 4. In the above formula (1), R ¹ and R ² are each independently , An atom or group selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 6 carbon atoms.)

  In the present invention, the cyan colorant preferably contains 1 to 20% by mass of the copper phthalocyanine derivative pigment.

  In this invention, it is preferable that the said mold release agent contains ester wax.

  In the present invention, the ester wax is preferably a polyfunctional ester wax having an acid value of 2 mgKOH / g or less and a hydroxyl value of 15 mgKOH / g or less.

  In the present invention, the release agent preferably contains a hydrocarbon wax.

  In the present invention, the copper phthalocyanine derivative pigment is surface-treated with a (co) polymer obtained by polymerizing at least one polymerizable monomer selected from the group consisting of styrene and alkyl (meth) acrylate. Copper phthalocyanine derivative pigments are preferred.

  According to the present invention as described above, by containing a copper phthalocyanine derivative pigment having a specific structure as a cyan colorant in the colored resin particles, the reflection density of the printed matter is high, the fixing strength is high, and the printing surface is smooth. Thus, a cyan toner that provides a high gloss print is provided.

  The cyan toner of the present invention is a cyan toner containing a binder resin, a release agent, and a cyan colorant, and the cyan colorant is a copper phthalocyanine derivative pigment represented by the following formula (1) or the following formula (2): It is characterized by containing.

（上記式（１）及び式（２）中、ＣｕＰｃは銅フタロシアニン残基であり、ｎは１〜４の整数である。また、上記式（１）中、Ｒ^１及びＲ^２はそれぞれ独立に、水素原子及び炭素数１〜６のアルキル基からなる群より選ばれる原子又は基である。）

(In the above formulas (1) and (2), CuPc is a copper phthalocyanine residue, and n is an integer of 1 to 4. In the above formula (1), R ¹ and R ² are each independently , An atom or group selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 6 carbon atoms.)

The cyan toner of the present invention (hereinafter sometimes simply referred to as “toner”) will be described below.
The cyan toner of the present invention contains a copper phthalocyanine derivative pigment having a predetermined structure as a binder resin, a release agent, and a cyan colorant.
Hereinafter, the manufacturing method of the colored resin particles used in the present invention, the colored resin particles obtained by the manufacturing method, the manufacturing method of the cyan toner of the present invention using the colored resin particles, and the cyan toner of the present invention will be described in order. To do.

1. Production method of colored resin particles Generally, the production method of colored resin particles is roughly classified into dry methods such as a pulverization method, and wet methods such as an emulsion polymerization aggregation method, a suspension polymerization method, and a dissolution suspension method. The wet method is preferable because it is easy to obtain a toner excellent in printing characteristics such as the property. Among wet methods, a polymerization method such as an emulsion polymerization aggregation method and a suspension polymerization method is preferable because a toner having a relatively small particle size distribution on the order of microns is preferable. A suspension polymerization method is more preferable among polymerization methods. preferable.

  In the emulsion polymerization aggregation method, an emulsified polymerizable monomer is polymerized to obtain a resin fine particle emulsion, which is aggregated with a colorant dispersion or the like to produce colored resin particles. The dissolution suspension method produces droplets of a solution in which toner components such as a binder resin and a colorant are dissolved or dispersed in an organic solvent in an aqueous medium, and the organic solvent is removed to produce colored resin particles. Each of which is a known method.

  The colored resin particles of the present invention can be produced by employing a wet method or a dry method. Among the wet methods, a preferred suspension polymerization method is adopted, and the following process is performed.

(A) Suspension polymerization method (A-1) Preparation step of polymerizable monomer composition First, a polymerizable monomer, a release agent, a cyan colorant, and a charge control agent added as necessary. These other additives are mixed to prepare a polymerizable monomer composition. The mixing at the time of preparing the polymerizable monomer composition is performed using, for example, a media type dispersing machine.

  In the present invention, the polymerizable monomer means a monomer having a polymerizable functional group, and the polymerizable monomer is polymerized to become a binder resin. It is preferable to use a monovinyl monomer as the main component of the polymerizable monomer. Examples of the monovinyl monomer include styrene; styrene derivatives such as vinyl toluene and α-methylstyrene; acrylic acid and methacrylic acid; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, acrylic acid 2 Acrylic esters such as ethylhexyl and dimethylaminoethyl acrylate; methacrylic esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and dimethylaminoethyl methacrylate; acrylonitrile And nitrile compounds such as methacrylonitrile; amide compounds such as acrylamide and methacrylamide; olefins such as ethylene, propylene, and butylene. These monovinyl monomers can be used alone or in combination of two or more. Of these, styrene, styrene derivatives, and acrylic esters or methacrylic esters are preferably used as monovinyl monomers.

In order to improve hot offset and storage stability, it is preferable to use any crosslinkable polymerizable monomer together with the monovinyl monomer. A crosslinkable polymerizable monomer means a monomer having two or more polymerizable functional groups. Examples of the crosslinkable polymerizable monomer include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; alcohols having two or more hydroxyl groups such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate; Examples include ester compounds in which two or more carboxylic acids are ester-bonded; other divinyl compounds such as N, N-divinylaniline and divinyl ether; compounds having three or more vinyl groups. These crosslinkable polymerizable monomers can be used alone or in combination of two or more.
In the present invention, the crosslinkable polymerizable monomer is usually used at a ratio of 0.1 to 5 parts by mass, preferably 0.3 to 2 parts by mass with respect to 100 parts by mass of the monovinyl monomer. desirable.

  Furthermore, it is preferable to use a macromonomer as a part of the polymerizable monomer because the balance between the storage stability of the obtained toner and the fixing property at low temperature is improved. The macromonomer has a polymerizable carbon-carbon unsaturated double bond at the end of the molecular chain, and is a reactive oligomer or polymer having a number average molecular weight of usually 1,000 to 30,000. The macromonomer is preferably one that gives a polymer having a higher Tg than the glass transition temperature of the polymer obtained by polymerizing the monovinyl monomer (hereinafter sometimes referred to as “Tg”). The macromonomer is preferably used in an amount of 0.03 to 5 parts by mass, more preferably 0.05 to 1 part by mass, with respect to 100 parts by mass of the monovinyl monomer.

  The copper phthalocyanine derivative pigment contained in the cyan colorant used in the cyan toner of the present invention has a structure represented by the following formula (1) or formula (2).

In the above formulas (1) and (2), CuPc is a copper phthalocyanine residue, and n is an integer of 1 to 4. In the formula (1), R ¹ and R ² are each independently an atom or group selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. R ¹ and R ² are preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and still more preferably an ethyl group. n is preferably 2 to 4, and more preferably 2.

  The copper phthalocyanine derivative pigment is prepared by adding a salt-forming amine to a reaction product obtained by a known phthalic anhydride method or a phthalonitrile method. It can be produced by pigmentation by the method. Of these production methods, grinding by a solvent milling method is preferred. Specifically, the reaction is carried out using phthalic anhydride or phthalonitrile having a sulfo group at the 4-position, and 2- (diethylamino) acetonitrile or 1,4-diazabicyclo [2,2,2] octane is added. An ammonium salt is produced, and the ammonium salt is pigmented by a sulfuric acid method, a solvent milling method, or the like. As described above, n is particularly preferably 2. In this case, 1: 1 is used for phthalic anhydride or phthalonitrile having a sulfo group at the 4-position and unsubstituted tetraphthalic anhydride or phthalonitrile. It will be made to react by molar ratio. Since the production of a copper phthalocyanine pigment requires 4 molecules of phthalic anhydride and the like, even if they are reacted in equimolar amounts, the average is n = 2. It is considered that the mixture is probably a mixture of 1 to 3.

The grinding by the solvent milling method is a method in which a crude copper phthalocyanine derivative pigment is wet-ground in an organic liquid using a grinding device, and a grinding aid is preferably used. As the grinding aid, for example, at least one selected from water-soluble inorganic salts such as sodium chloride, sodium sulfate and calcium chloride can be used. It is preferable to use a grinding aid previously pulverized by a pulverizer. The usage-amount is 2-10 mass times with respect to a crude copper phthalocyanine derivative pigment, Preferably it is 3-8 mass times.
The organic liquid is preferably at least slightly water-soluble. For example, at least one selected from liquid alcohols and liquid polyols can be suitably used. Examples of liquid alcohols include n-propyl alcohol, n-butyl alcohol, isopropyl alcohol, and isobutyl alcohol. Examples of liquid polyols include liquid polyols, liquid polyol ethers, liquid polyol esters, and the like. Examples thereof include chlorinated derivatives. For example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapyrene glycol and the like can be used. The usage-amount of an organic liquid is 0.1-2.0 mass times with respect to a crude copper phthalocyanine derivative pigment, Preferably it is 0.3-1.5 mass times.

As the wet milling apparatus, kneaders that have been used in conventional wet milling methods such as various mixers and kneaders can be used as they are.
The wet grinding time varies depending on the amount of the apparatus, grinding aid and organic liquid, but is 1 to 15 hours, preferably 2 to 10 hours. Although it may be longer than 15 hours, it is not preferable because the quality of the pigment is hardly changed and the energy efficiency is deteriorated. The wet grinding temperature varies depending on the amount of the apparatus, the grinding aid and the organic liquid, and further the grinding time, but is usually 20 to 150 ° C, preferably 80 to 130 ° C. When the temperature is higher than 150 ° C., crystals grow large and it is necessary to shorten the wet milling for a short time. Since the temperature gradually rises and equilibrates at 90 to 120 ° C. after the start of wet grinding, heating or cooling is performed as necessary.
The copper phthalocyanine pigment after wet milling is processed by a conventional method. That is, the grinding mixture is treated with water or dilute acid, the grinding aid and the organic liquid are removed by filtration and washing with water, and the pigment is isolated. The pigment can be used in a wet state as it is or in a powder state by drying. If necessary, a resin, a surfactant, and other additives may be added after wet grinding.

  In the present invention, the effect of the present invention can be obtained if the copper phthalocyanine derivative pigment is 1 to 20% by mass of the cyan colorant, but 5 to 15% by mass is preferable, and 8 to 12% by mass is more preferable. As other cyan colorants, for example, anthraquinone compounds, copper phthalocyanine compounds other than the copper phthalocyanine derivative pigments described above, and derivatives thereof can be used. Specifically, C.I. I. Pigment Blue 2, 3, 6, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 17: 1, 60 and the like. I. Pigment Blue 15: 3 and 15: 4 are preferable.

The cyan colorant containing the copper phthalocyanine derivative pigment used in the cyan toner of the present invention is surface-treated with a polymer and / or copolymer (hereinafter sometimes referred to as (co) polymer). preferable. By performing the surface treatment with the (co) polymer, the reflection density of the printed matter is improved and the gloss is also improved. Hereinafter, the surface treatment using a copolymer will be described.
The surface treatment method is not particularly limited as long as the copolymer can be adsorbed on the surface of the cyan colorant containing the copper phthalocyanine derivative pigment, and the cyan coloration containing the copper phthalocyanine derivative pigment in the solution in which the copolymer is dissolved. An agent may be added, or a solution in which a copolymer is dissolved in a cyan colorant containing a copper phthalocyanine derivative pigment may be sprayed. Thereafter, the surface treatment is terminated by evaporating the solvent used.
The solvent used for the surface treatment is not particularly limited as long as the (co) polymer can be dissolved. However, since it is easy to dissolve the (co) polymer obtained by polymerizing a preferable polymerizable monomer described later, a hydrocarbon solvent. An ester solvent and an ether solvent are preferable, and among them, toluene, tetrahydrofuran, and ethyl acetate are preferable.

As the polymerizable monomer constituting the (co) polymer, the same polymerizable monomer that can be used for the polymerization of the binder resin can be used. From the viewpoint that the (co) polymer is preferably part of the binder resin, the polymerizable monomer constituting the (co) polymer is a preferred polymerizable monomer constituting the binder resin. A homopolymer or copolymer obtained by polymerizing at least one polymerizable monomer selected from the group consisting of styrene and alkyl (meth) acrylate is preferred. In the present specification, the expression “(meth) acrylic acid” is a generic term for both acrylic acid and methacrylic acid.
The (co) polymer preferably has a glass transition temperature close to that of the binder resin. Specifically, it is preferably 20 to 80 ° C, more preferably 30 to 75 ° C, still more preferably 40 to 70 ° C, and particularly preferably 50 to 65 ° C. When the glass transition temperature is lower than the above range, the storage stability may be deteriorated, whereas when it is high, the fixability may be deteriorated.

The number average molecular weight (Mn) of the (co) polymer is preferably 3,000 to 20,000, more preferably 5,000 to 15,000, and 8,000 to 12,000. It is particularly preferred. The molecular weight distribution (Mw / Mn), which is the ratio of the number average molecular weight and the weight average molecular weight (Mw) of the (co) polymer, is preferably 1.0 to 2.0, and preferably 1.0 to 1. 5 is more preferable, and 1.0 to 1.3 is still more preferable.
The amount of the (co) polymer used is preferably 1 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of the cyan colorant containing a copper phthalocyanine derivative pigment. It is especially preferable that it is -12 mass parts.

  From the viewpoint of improving the releasability of the toner from the fixing roll during fixing, a release agent is added to the polymerizable monomer composition. Any releasing agent can be used without particular limitation as long as it is generally used as a releasing agent for toner.

In the present invention, the release agent preferably contains an ester wax and / or a hydrocarbon wax, and the ester wax is a polyfunctional ester wax having an acid value of 2 mgKOH / g or less and a hydroxyl value of 15 mgKOH / g or less. It is preferable that The hydrocarbon wax is preferably paraffin wax. By using these waxes as a release agent, the balance between low-temperature fixability and storage stability can be made suitable.
The ester wax suitably used as a release agent in the present invention is more preferably a polyfunctional ester wax, such as pentaerythrole tetrapalinate, pentaerythrole tetrabehenate, pentaerythrole tetrastearate, etc. Pentaerythritol ester compound; hexaglycerin tetrabehenate tetrapalinate, hexaglycerin octabehenate, pentaglycerin heptabehenate, tetraglycerin hexabehenate, triglycerin pentabehenate, diglycerin tetrabehenate, Glycerin ester compounds such as glycerin tribehenate; dipentaerythritol ester compounds such as dipentaerystol hexamilitate and dipentaerystol hexapalinate; Glycerin ester compounds are preferred, hexaglycerin tetrabehenate tetrapalinate, hexaglycerin octabehenate, tetraglycerin hexabehenate, and triglycerin pentabehenate are more preferred, and hexaglycerin octabehenate is particularly preferred. preferable.

  The acid value of the ester wax is preferably 2 mgKOH / g or less, more preferably 1 mgKOH / g or less, and further preferably 0.5 mgKOH / g or less. In addition, the acid value of ester wax is a value measured based on JOCS 2.3.1-96 using the standard oil-fat analysis method established by Japan Oil Chemical Association (JOCS).

  When the acid value of the ester wax exceeds the upper limit, more unreacted monovalent fatty acid-derived carboxylic acid groups remain in the ester wax. It becomes difficult to stably form droplets of the monomer composition, adversely affects the particle size characteristics of the colored resin particles, easily deteriorates the image quality due to fog, etc., and generates volatile substances during fixing. May cause odor.

  In the present invention, the hydroxyl value of the ester wax is preferably 15 mgKOH / g or less, more preferably 10 mgKOH / g or less, and further preferably 5 mgKOH / g or less. In addition, the hydroxyl value of ester wax is a value measured based on JOCS 2.3.6.2-96, using the standard oil analysis test method established by Japan Oil Chemical Association (JOCS).

  When the hydroxyl value of the ester wax exceeds the upper limit, more hydroxyl groups derived from unreacted raw materials remain in the ester wax. It may be difficult to stably form droplets, adversely affect the particle size characteristics of the colored resin particles, and image quality may be deteriorated due to fog or the like.

Examples of the hydrocarbon wax suitably used as a release agent in the present invention include polyethylene wax, polypropylene wax, Fischer-Tropsch wax, petroleum-based wax, etc. Among them, Fischer-Tropsch wax and petroleum-based wax are preferable, and petroleum-based wax. Is more preferable.
The number average molecular weight of the hydrocarbon wax is preferably 300 to 800, more preferably 400 to 600. Moreover, the penetration of the hydrocarbon wax measured by JIS K2235 5.4 is preferably 1 to 10, and more preferably 2 to 7.

  The above-mentioned petroleum-based wax refers to a solid that is produced from a petroleum refining process and is solid at room temperature mainly composed of a saturated hydrocarbon having a side chain. In JIS K 2235, paraffin wax, microstalline wax, and petratum are used. There are three main types. In the present invention, it is preferable to select at least one of these three types and use it as a component of the release agent. Among petroleum waxes, paraffin wax and microstalline wax are more preferable from the viewpoint of achieving a good balance between low-temperature fixability and storage stability of the toner.

In addition to the mold release agent, for example, natural wax such as jojoba; mineral wax such as ozokerite;
The mold release agent may be used in combination with one or more waxes as described above.
The release agent is preferably used in an amount of 0.1 to 30 parts by mass, and more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the monovinyl monomer.

As other additives, a positively or negatively chargeable charge control agent can be used to improve the chargeability of the toner.
The charge control agent is not particularly limited as long as it is generally used as a charge control agent for toner, but among charge control agents, the compatibility with the polymerizable monomer is high, and stable chargeability. (Charge stability) can be imparted to the toner particles, and therefore a positively or negatively chargeable charge control resin is preferred. Further, from the viewpoint of obtaining a positively chargeable toner, a positively chargeable charge control resin is preferred. More preferably used.
Examples of positively chargeable charge control agents include nigrosine dyes, quaternary ammonium salts, triaminotriphenylmethane compounds and imidazole compounds, polyamine resins as charge control resins that are preferably used, and quaternary ammonium group-containing copolymers. , And quaternary ammonium base-containing copolymers.
Negatively chargeable charge control agents include azo dyes containing metals such as Cr, Co, Al, and Fe, salicylic acid metal compounds and alkylsalicylic acid metal compounds, and sulfonic acid group containing charge control resins that are preferably used Examples thereof include a copolymer, a sulfonate group-containing copolymer, a carboxylic acid group-containing copolymer, and a carboxylic acid group-containing copolymer.
In the present invention, the charge control agent is usually used in a proportion of 0.01 to 10 parts by mass, preferably 0.03 to 8 parts by mass, with respect to 100 parts by mass of the monovinyl monomer. If the addition amount of the charge control agent is less than 0.01 parts by mass, fog may occur. On the other hand, when the addition amount of the charge control agent exceeds 10 parts by mass, printing stains may occur.

As other additives, it is preferable to use a molecular weight modifier when polymerizing a polymerizable monomer that is polymerized to become a binder resin.
The molecular weight modifier is not particularly limited as long as it is generally used as a molecular weight modifier for toner. For example, t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, and 2,2, Mercaptans such as 4,6,6-pentamethylheptane-4-thiol; tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, N, N′-dimethyl-N, N′-diphenylthiuram disulfide, N, And thiuram disulfides such as N′-dioctadecyl-N, N′-diisopropylthiuram disulfide; These molecular weight modifiers may be used alone or in combination of two or more.
In this invention, it is desirable to use a molecular weight modifier in the ratio of 0.01-10 mass parts normally with respect to 100 mass parts of monovinyl monomers, Preferably it is 0.1-5 mass parts.

(A-2) Suspension step for obtaining a suspension (droplet formation step)
In the present invention, a polymerizable monomer composition containing at least a polymerizable monomer, a releasing agent, and a cyan colorant containing a copper phthalocyanine pigment derivative is dispersed in an aqueous medium containing a dispersion stabilizer, and polymerization is performed. After the initiator is added, droplet formation of the polymerizable monomer composition is performed. The method for forming droplets is not particularly limited. For example, (in-line type) emulsifying disperser (trade name “Milder” manufactured by Ebara Manufacturing Co., Ltd.), high-speed emulsifying disperser (made by Tokushu Kika Kogyo Co., Ltd., trade name “T. K. Homomixer MARK Type II ") or the like capable of strong stirring.

  As a polymerization initiator, persulfates such as potassium persulfate and ammonium persulfate: 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-methyl-N- (2- Hydroxyethyl) propionamide), 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (2,4-dimethylvaleronitrile), and 2,2′-azobisisobutyronitrile Di-t-butyl peroxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylbutanoate, diisopropylperoxydicarbonate, di- Organic peroxides such as -t-butylperoxyisophthalate and t-butylperoxyisobutyrate It is. These can be used alone or in combination of two or more. Among these, it is preferable to use an organic peroxide because residual polymerizable monomers can be reduced and printing durability is excellent.

  Among organic peroxides, peroxyesters are preferable because non-aromatic peroxyesters, that is, peroxyesters having no aromatic ring, are preferable because initiator efficiency is good and the amount of remaining polymerizable monomers can be reduced. More preferred.

  As described above, the polymerization initiator may be added before the droplet formation after the polymerizable monomer composition is dispersed in the aqueous medium. However, the polymerization initiator is not dispersed in the aqueous medium. It may be added to the monomer composition.

  The addition amount of the polymerization initiator used for the polymerization of the polymerizable monomer composition is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 100 parts by mass of the monovinyl monomer. It is -15 mass parts, Most preferably, it is 1-10 mass parts.

  In the present invention, the aqueous medium refers to a medium containing water as a main component.

  In the present invention, the aqueous medium preferably contains a dispersion stabilizer. Examples of the dispersion stabilizer include sulfates such as barium sulfate and calcium sulfate; carbonates such as barium carbonate, calcium carbonate and magnesium carbonate; phosphates such as calcium phosphate; metals such as aluminum oxide and titanium oxide. Oxides; metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and ferric hydroxide; inorganic compounds such as; water-soluble polymers such as polyvinyl alcohol, methylcellulose, and gelatin; anionic surfactants; Organic compounds such as nonionic surfactants; amphoteric surfactants; The said dispersion stabilizer can be used 1 type or in combination of 2 or more types.

  Among the above dispersion stabilizers, inorganic compounds, particularly colloids of poorly water-soluble metal hydroxides are preferred. By using a colloid of an inorganic compound, particularly a poorly water-soluble metal hydroxide, the particle size distribution of the colored resin particles can be narrowed, and the residual amount of the dispersion stabilizer after washing can be reduced. The polymerized toner can reproduce an image clearly and does not deteriorate environmental stability.

(A-3) Polymerization step As in (A-2) above, droplet formation is performed, the resulting aqueous dispersion medium is heated to initiate polymerization, and an aqueous dispersion of colored resin particles is formed.
The polymerization temperature of the polymerizable monomer composition is preferably 50 ° C. or higher, more preferably 60 to 95 ° C. The polymerization reaction time is preferably 1 to 20 hours, more preferably 2 to 15 hours.

  The colored resin particles may be used as a polymerized toner by adding an external additive as it is, but the so-called core-shell type obtained by using the colored resin particles as a core layer and forming a shell layer different from the core layer on the outside thereof. It is preferable to use colored resin particles (also referred to as “capsule type”). The core-shell type colored resin particles balance the reduction of the fixing temperature and the prevention of aggregation during storage by coating the core layer made of a material having a low softening point with a material having a higher softening point. be able to.

  There is no restriction | limiting in particular as a method of manufacturing a core shell type colored resin particle using the said colored resin particle mentioned above, It can manufacture by a conventionally well-known method. An in situ polymerization method and a phase separation method are preferable from the viewpoint of production efficiency.

A method for producing core-shell type colored resin particles by in situ polymerization will be described below.
Addition of a polymerizable monomer (polymerizable monomer for shell) and a polymerization initiator to form a shell layer into an aqueous medium in which colored resin particles are dispersed, and then polymerize to form a core-shell type color. Resin particles can be obtained.

  As the polymerizable monomer for the shell, the same monomers as the aforementioned polymerizable monomers can be used. Among them, it is preferable to use monomers such as styrene, acrylonitrile, and methyl methacrylate, which can obtain a polymer having a Tg exceeding 80 ° C., alone or in combination of two or more.

  As a polymerization initiator used for polymerization of the polymerizable monomer for shell, persulfate metal salts such as potassium persulfate and ammonium persulfate; 2,2′-azobis (2-methyl-N- (2-hydroxyethyl) Water-soluble such as azo initiators such as) propionamide) and 2,2′-azobis- (2-methyl-N- (1,1-bis (hydroxymethyl) 2-hydroxyethyl) propionamide); A polymerization initiator can be mentioned. These can be used alone or in combination of two or more. The amount of the polymerization initiator is preferably 0.1 to 30 parts by mass, and more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer for shell.

  The polymerization temperature of the shell layer is preferably 50 ° C. or higher, more preferably 60 to 95 ° C. The polymerization reaction time is preferably 1 to 20 hours, more preferably 2 to 15 hours.

(A-4) Washing, filtration, dehydration, and drying steps The aqueous dispersion of colored resin particles obtained by polymerization is washed, dehydrated, and filtered to remove the dispersion stabilizer according to a conventional method after completion of the polymerization. The drying operation is preferably repeated several times as necessary.

  As the above washing method, when an inorganic compound is used as the dispersion stabilizer, the dispersion stabilizer can be dissolved in water and removed by adding an acid or alkali to the aqueous dispersion of colored resin particles. preferable. When a colloid of a poorly water-soluble inorganic hydroxide is used as the dispersion stabilizer, it is preferable to adjust the pH of the colored resin particle aqueous dispersion to 6.5 or less by adding an acid. As the acid to be added, inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid, and organic acids such as formic acid and acetic acid can be used. Particularly, since the removal efficiency is large and the burden on the manufacturing equipment is small, Sulfuric acid is preferred.

  Various known methods and the like can be used as the method of dehydration and filtration, and there is no particular limitation. Examples thereof include a centrifugal filtration method, a vacuum filtration method, and a pressure filtration method. Also, the drying method is not particularly limited, and various methods can be used.

(B) Pulverization method When the pulverization method is used to produce colored resin particles, the following process is performed.
First, a binder, a release agent, a cyan colorant containing a copper phthalocyanine pigment derivative, and other additives such as a charge control agent added as necessary are mixed in a mixer such as a ball mill or V-type mixer. Mix using a machine, Henschel mixer (trade name), high-speed dissolver, internal mixer, Fallberg, etc. Next, the mixture obtained as described above is kneaded while being heated using a pressure kneader, a twin-screw extrusion kneader, a roller or the like. The obtained kneaded material is coarsely pulverized using a pulverizer such as a hammer mill, a cutter mill, or a roller mill. Furthermore, after finely pulverizing using a pulverizer such as a jet mill or a high-speed rotary pulverizer, it is classified into a desired particle size by a classifier such as an air classifier or an airflow classifier, and colored resin particles obtained by a pulverization method. Get.

  In addition, other additives such as the binder resin used in the pulverization method, the mold release agent, the cyan colorant, and the charge control agent added as necessary are listed in the above (A) suspension polymerization method. Things can be used. Further, the colored resin particles obtained by the pulverization method can be made into core-shell type colored resin particles by a method such as an in situ polymerization method in the same manner as the colored resin particles obtained by the suspension polymerization method (A) described above.

  As the binder resin, other resins that have been widely used for toners can be used. Specific examples of the binder resin used in the pulverization method include polystyrene, styrene-butyl acrylate copolymer, polyester resin, and epoxy resin.

2. Colored resin particles Colored resin particles are obtained by a production method such as the above-described (A) suspension polymerization method or (B) pulverization method.
Hereinafter, the colored resin particles constituting the cyan toner will be described. The colored resin particles described below include both core-shell type and non-core type.

  The volume average particle diameter (Dv) of the colored resin particles is preferably 4 to 12 μm, and more preferably 5 to 10 μm. When Dv is less than 4 μm, the fluidity of the polymerized toner is lowered, and transferability may be deteriorated or the image density may be lowered. When Dv exceeds 12 μm, the resolution of the image may decrease.

  The colored resin particles have a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of preferably 1.0 to 1.3, more preferably 1. 0-1.2. If Dv / Dn exceeds 1.3, transferability, image density, and resolution may decrease. The volume average particle diameter and the number average particle diameter of the colored resin particles can be measured using, for example, a particle size analyzer (trade name “Multisizer” manufactured by Beckman Coulter).

The average circularity of the colored resin particles used in the present invention is preferably 0.96 to 1.00, more preferably 0.97 to 1.00, from the viewpoint of image reproducibility. More preferably, it is .98-1.00.
When the average circularity of the colored resin particles is less than 0.96, the fine line reproducibility of printing may be deteriorated.

  In the present invention, the circularity is defined as a value obtained by dividing the circumference of a circle having the same projected area as the particle image by the circumference of the projected image of the particle. The average circularity in the present invention is used as a simple method for quantitatively expressing the shape of the particles, and is an index indicating the degree of unevenness of the colored resin particles. The average circularity is determined by the colored resin particles. 1 is shown in the case of a perfect sphere, and the value becomes smaller as the surface shape of the colored resin particles becomes more complicated.

  The colored resin particles preferably exhibit positive chargeability. If negatively charged colored resin particles are used, the charge amount of the toner may be reduced and fogging may occur easily.

3. Method for Producing Cyan Toner of the Present Invention In the present invention, the colored resin particles can be used as they are as a cyan toner. However, from the viewpoint of adjusting the chargeability, fluidity, storage stability, etc. of the toner, It is preferable that the resin particles are mixed and stirred together with the external additive to perform an external addition treatment, thereby attaching the external additive to the surface of the colored resin particles to obtain a one-component cyan toner (developer).
The one-component cyan toner may be further mixed and stirred together with carrier particles to form a two-component developer.

  The stirrer that performs the external addition treatment is not particularly limited as long as the stirrer can attach the external additive to the surface of the colored resin particles. For example, an FM mixer (trade name, manufactured by Nippon Coke Kogyo Co., Ltd.), Super Mixer (: trade name, manufactured by Kawada Seisakusho Co., Ltd.), Q mixer (: trade name, manufactured by Nihon Coke Kogyo Co., Ltd.), mechano-fusion system (: trade name, manufactured by Hosokawa Micron Co., Ltd.), and mechano mill (: trade name, Okada Seiko Co., Ltd.) The external addition treatment can be performed using a stirrer capable of mixing and stirring such as (made).

Examples of the external additive include inorganic fine particles composed of silica, titanium oxide, aluminum oxide, zinc oxide, tin oxide, calcium carbonate, calcium phosphate, and / or cerium oxide; polymethyl methacrylate resin, silicone resin, and / or melamine Organic fine particles made of a resin or the like; Among these, inorganic fine particles are preferable, and among inorganic fine particles, silica and / or titanium oxide are preferable, and fine particles made of silica are particularly preferable.
These external additives can be used alone or in combination of two or more. Among these, it is preferable to use two or more types of silica having different particle diameters in combination.

  In the present invention, the external additive is usually used in a proportion of 0.05 to 6 parts by mass, preferably 0.2 to 5 parts by mass with respect to 100 parts by mass of the colored resin particles. When the added amount of the external additive is less than 0.05 parts by mass, a transfer residue may occur. If the amount of the external additive exceeds 6 parts by mass, fog may occur.

4). Cyan Toner of the Present Invention The cyan toner of the present invention obtained through the above steps has a high reflection density of printed matter and a fixing strength by containing a copper phthalocyanine derivative pigment having a specific structure as a cyan colorant in the colored resin particles. Is a cyan toner which gives a high gloss print with a high print density and a smooth printing surface.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited only to these examples. Parts and% are based on mass unless otherwise specified.
The test methods performed in the examples and comparative examples are as follows.

1. Synthesis of copolymer 70 parts of styrene as a monovinyl monomer, 20 parts of n-butyl acrylate, 10 parts of methyl methacrylate, and 1.2 parts of t-dodecyl mercaptan as a molecular weight modifier are mixed to obtain a polymerizable monomer. A body composition was obtained.
On the other hand, in a stirring tank, an aqueous solution in which 7.4 parts of magnesium chloride was dissolved in 250 parts of ion-exchanged water and an aqueous solution in which 4.1 parts of sodium hydroxide were dissolved in 50 parts of ion-exchanged water were stirred at room temperature. The mixture was gradually added to prepare a magnesium hydroxide colloid dispersion (magnesium hydroxide 3.0 parts).

The above-described polymerizable monomer composition is charged into the magnesium hydroxide colloid dispersion obtained as described above at room temperature, and stirred until the droplets are stabilized, where t-butyl peroxy- is used as a polymerization initiator. After adding 5 parts of 2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perbutyl O), using an in-line type emulsifying disperser (trade name: Ebara Milder, manufactured by Ebara Seisakusho), 15,000 rpm High-shear stirring was performed at a rotational speed to form droplets of the polymerizable monomer composition.
A suspension (polymerizable monomer composition dispersion) in which droplets of the polymerizable monomer composition obtained as described above are dispersed is charged into a reactor equipped with a stirring blade and heated to 90 ° C. Warm to initiate the polymerization reaction. Sulfuric acid was added dropwise to the aqueous dispersion of resin particles while stirring at room temperature, and acid washing was performed until the pH became 6.5 or lower. Subsequently, filtration separation was performed, 500 parts of ion-exchanged water was added to the obtained solid content to make a slurry again, and water washing treatment (washing, filtration, dehydration) was repeated several times. Subsequently, filtration separation was performed, and the obtained solid content was put in a container of a dryer and dried at 45 ° C. for 48 hours to obtain a copolymer of styrene, n-butyl acrylate and methyl methacrylate.

2. Evaluation of properties of copolymer The number average molecular weight and glass transition temperature of the copolymer of styrene, n-butyl acrylate and methyl methacrylate synthesized by the above method were measured. Details are as follows.

2-1. Measurement of number average molecular weight (Mn) The number average molecular weight (Mn) was measured under the following conditions.
1) After 0.1 g of the precisely weighed copolymer is put into a 100 mL glass sample bottle, 49.9 g of THF is added.
2) Next, a stirrer chip was put and stirred for 1 hour at room temperature using a magnetic stirrer to dissolve the binder resin and the like to obtain a dispersion.
3) The dispersion is filtered through a 0.2 μm PTFE filter to obtain a THF solution.
4) 100 μL of each THF solution is injected into a GPC measuring apparatus and measured. The molecular weight was obtained by converting the obtained GPC elution curve from a calibration curve obtained from commercially available monodisperse standard polystyrene.
(Measurement condition)
GPC: HLC-8220 (manufactured by Tosoh Corporation)
Column: TSK-GEL MULTIPORE HXL-M 2 directly connected (manufactured by Tosoh Corporation)
Eluent: THF
Flow rate: 1.0 mL / min
Temperature: 40 ° C
When measured under the above conditions, the number average molecular weight (Mn) of the copolymer was 12,000.

2-2. Measurement of glass transition temperature (° C.) In accordance with ASTM D3418-82, the maximum endothermic peak temperature of the copolymer used in the surface treatment of the pigment was measured. More specifically, the temperature of the sample was raised at a rate of temperature rise of 10 ° C./min using a differential scanning calorimeter, and the temperature indicating the glass transition temperature of the DSC curve obtained in the process was measured. As a differential scanning calorimeter, “SSC5200” manufactured by Seiko Denshi Kogyo Co., Ltd. was used.
When measured under the above conditions, the glass transition temperature of the copolymer was 54 ° C.

3. Synthesis of copper phthalocyanine derivative pigment [Production Example 1 of copper phthalocyanine derivative pigment]
100 parts of phthalic anhydride, 154 parts of 4-sulfophthalic acid, 204 parts of urea, 35 parts of cuprous chloride and 1 part of ammonium molybdate are suspended in 400 parts of diisopropyl toluene and stirred at 200 ° C. under normal pressure for 4 hours. A heating reaction was performed.
Thereafter, the temperature was cooled to 80 ° C., 100 parts of 2- (diethylamino) acetonitrile was added, and the mixture was reacted at that temperature for 2 hours. After completion of the reaction, the reaction product diisopropyltoluene and unreacted 2- (diethylamino) acetonitrile are distilled off by distillation under reduced pressure, followed by hot water washing, then acid washing, and finally further water washing and drying. As a result, 232 parts of a crude copper phthalocyanine derivative was obtained.
100 parts of the crude copper phthalocyanine derivative obtained above, 500 parts of crushed sodium chloride, and 80 parts of diethylene glycol were charged into a 1000-volume part double-arm kneader and kneaded for 8 hours while maintaining a dense lump at 100-110 ° C. The grinding was done. After grinding, the mixture was taken out into 1300 parts of a 1% aqueous sulfuric acid solution at 70 ° C., stirred for 1 hour, filtered, washed with water and dried to obtain a copper phthalocyanine derivative pigment 1.

[Production Example 2 of copper phthalocyanine derivative pigment]
In Production Example 1 of the copper phthalocyanine derivative pigment, the same procedure as in Production Example 1 except that 100 parts of 2- (diethylamino) acetonitrile was changed to 100 parts of 1,4-diazabicyclo [2,2,2] octane. A copper phthalocyanine derivative pigment 2 was obtained.

4). Preparation of Cyan Pigment Composition [Cyan Pigment Composition Production Example 1]
10 parts of the copolymer of styrene, n-butyl acrylate and methyl methacrylate described in the above section “1. Synthesis of copolymer” was dissolved in 50 parts of ethyl acetate. While stirring the copolymer solution, C.I. I. 90 parts of Pigment Blue 15 and 10 parts of copper phthalocyanine derivative pigment 1 obtained in Production Example 1 of copper phthalocyanine derivative pigment were added to the copolymer solution. After stirring the solution for 1 hour, ethyl acetate in the solution was removed and the pigment was subjected to a surface treatment to obtain a cyan pigment composition 1 containing a copper phthalocyanine derivative pigment.

[Production Example 2 of Cyan Pigment Composition]
In Production Example 1 of the cyan pigment composition, 10 parts of the copper phthalocyanine derivative pigment 1 were changed to 10 parts of the copper phthalocyanine derivative pigment 2, and the addition amount of the copolymer of styrene, n-butyl acrylate and methyl methacrylate was 10 parts. A cyan pigment composition 2 was obtained in the same manner as in Cyan Pigment Production Example 1 except that the amount was changed to 6 parts.

5. Preparation of cyan toner [Example 1]
As a monovinyl monomer, 65 parts of styrene, 25 parts of butyl acrylate, and 5 parts of the cyan pigment composition 1 are added and stirred to prepare a polymerizable monomer mixture. And finely dispersed to obtain a polymerizable monomer dispersion.

  Next, 10 parts of styrene as a monovinyl monomer and 5 parts of a charge control agent (styrene / acrylic resin, manufactured by Fujikura Kasei Co., Ltd., trade name “FCA-207P”) are added to 95.5 parts of the polymerizable monomer dispersion. 2 parts hexaglycerin octabehenate as release agent, 5 parts paraffin wax (manufactured by Nippon Seiwa Co., Ltd., trade name “HNP-11”) and 1.0 part t-dodecyl mercaptan as molecular weight regulator and crosslinking As a polymerizable monomer, 0.4 part of divinylbenzene was added and dissolved by stirring to prepare a polymerizable monomer composition.

  On the other hand, to an aqueous solution in which 8.5 parts of magnesium chloride is dissolved in 250 parts of ion-exchanged water, an aqueous solution in which 6 parts of sodium hydroxide is dissolved in 50 parts of ion-exchanged water is gradually added with stirring. A slightly water-soluble metal hydroxide colloid) aqueous dispersion medium was prepared.

  The polymerizable monomer composition is added to the magnesium hydroxide colloidal aqueous dispersion medium obtained as described above, and after stirring, t-butylperoxy-2-ethylhexanoate (Nippon Yushi Co., Ltd.) is used as a polymerization initiator. And 5 parts of the product name “Perbutyl O”) was added, and using an in-line type emulsifying disperser, high shear stirring was performed at a peripheral speed of 40 m / s and a circulation number θ of 10 times. Droplets of the monomer composition were formed.

  The aqueous dispersion medium liquid in which droplets of the polymerizable monomer composition were dispersed was put into a reactor equipped with a stirring blade, and a polymerization reaction was started at 90 ° C. After the polymerization conversion rate reached almost 100%, the polymerization temperature was kept as it was, and 2 parts of 2,2′-azobis (2- (2) dissolved in 2 parts of methyl methacrylate as a polymerizable monomer for shell and 10 parts of ion-exchanged water. 0.1 part of methyl-N- (2-hydroxyethyl) propionamide) (manufactured by Wako Pure Chemical Industries, Ltd., trade name “VA086”) was added and the reaction was continued at 90 ° C. for 3 hours, and then the reaction was stopped. Thus, an aqueous dispersion of cyan colored resin particles having a core-shell structure was obtained. The pH of the aqueous dispersion was 9.5.

  While stirring the aqueous dispersion of cyan colored resin particles obtained above, the pH of the aqueous dispersion was adjusted to 6 or less with sulfuric acid, and the aqueous phase was separated by filtration. Thereafter, 500 parts of ion-exchanged water was newly added to reslurry, and the mixture was stirred for 10 minutes and washed with water. Filtration, dehydration, and water washing were repeated several times, and then the cyan colored resin particles were separated by filtration to obtain wet cyan colored resin particles. The wet cyan colored resin particles were vacuum dried at a temperature of 45 ° C. to obtain cyan colored resin particles.

  To 100 parts of the cyan colored resin particles obtained as described above, 0.7 part of silica fine particles having an average primary particle diameter of 7 nm hydrophobized and 1.5 parts of silica fine particles having an average primary particle diameter of 35 nm hydrophobized. The cyan toner of Example 1 was prepared by adding a part and mixing using an FM mixer.

[Example 2]
A cyan toner of Example 2 was produced in the same manner as in Example 1 except that 5 parts of cyan pigment composition 1 was changed to 5 parts of cyan pigment composition 2 in Example 1.

[Example 3]
In Example 1, 5 parts of cyan pigment composition 1 were mixed with 0.5 part of copper phthalocyanine derivative pigment 1 and C.I. I. Pigment Blue 15: 3 A cyan toner of Example 3 was produced in the same manner as in Example 1 except that the amount was changed to 4.5 parts.

[Comparative Example 1]
In Example 1, 5 parts of cyan pigment composition 1 were added to C.I. I. Pigment Blue 15: 3 (copper phthalocyanine) A cyan toner of Comparative Example 1 was prepared in the same manner as in Example 1 except that the amount was changed to 5 parts.

[Comparative Example 2]
In Example 1, 5 parts of the cyan pigment composition 1 were mixed with C.I. I. Pigment Blue 17: A cyan toner of Comparative Example 2 was produced in the same manner as in Example 1 except that the amount was changed to 15 parts.
_{^{CuPc- (SO 3 -) 2 Ba}} 2+ formula (3)
(In the above formula (3), CuPc represents a copper phthalocyanine residue.)

6). Evaluation of particle size characteristics of cyan colored resin particles The particle size characteristics of the cyan colored resin particles used in the cyan toners of Examples 1 to 3 and Comparative Examples 1 and 2 were examined. Details are as follows.

6-1. Volume average particle size (Dv), number average particle size (Dn), and particle size distribution (Dv / Dn)
About 0.1 g of cyan colored resin particles were weighed and taken in a beaker, and 0.1 mL of an alkylbenzenesulfonic acid aqueous solution (manufactured by Fuji Film, trade name: Drywell) was added as a dispersant. To the beaker, 10-30 mL of a special electrolyte (Beckman Coulter, trade name: Isoton II-PC) was further added and dispersed for 3 minutes with a 20 W ultrasonic disperser. A volume average particle diameter (Dv) of cyan colored resin particles under the conditions of aperture diameter: 100 μm, medium: Isoton II-PC, number of measured particles: 100,000. ) And the number average particle size (Dn) were measured, and the particle size distribution (Dv / Dn) was calculated.

6-2. Average circularity Into a container, 10 mL of ion-exchanged water is put in advance, 0.02 g of a surfactant (alkyl benzene sulfonic acid) as a dispersant is added therein, 0.02 g of cyan colored resin particles are further added, and ultrasonic dispersion is performed. The dispersion treatment was carried out at 60 W for 3 minutes. The cyan colored resin particle concentration at the time of measurement is adjusted to 3,000 to 10,000 particles / μL, and the flow equation is used for 1,000 to 10,000 cyan colored resin particles having an equivalent circle diameter of 0.4 μm or more. Measurement was performed using a particle image analyzer (trade name: FPIA-2100, manufactured by Simex Corporation). The average circularity was determined from the measured value.
The circularity is shown in the following calculation formula 1, and the average circularity is the number average.
Formula 1:
(Circularity) = (Perimeter of circle equal to projected area of particle) / (Perimeter of particle projection image)

7). Evaluation of cyan toner The toner characteristics of the cyan toners of Examples 1 to 3 and Comparative Examples 1 and 2 were examined. Details are as follows.

7-1. Fixing strength After using a printer modified so that the temperature of the fixing roll of a commercially available non-magnetic one-component developing printer can be changed, a toner cartridge in the developing device of the printer is charged with 100 g of cyan toner, and then a copying machine A normal paper (80 g / m ² ) transfer material was set, and a fixing test was performed as follows.
In the fixing test, solid (printing density 100%) is printed, and the temperature of the fixing roll of the modified printer is changed by 10 ° C. in the range of 170 to 200 ° C., and the fixing ratio of cyan toner at each temperature is measured. The relationship between temperature and fixing rate was obtained.
Note that, at each temperature changed by 10 ° C., the temperature state was maintained for 5 minutes or more in order to stabilize the temperature of the fixing roll.
The fixing rate was calculated from the ratio of the image density before and after the tape was peeled off in the solid printing area (printing density 100%). That is, when the image density before tape peeling (Image Density) is ID (front) and the image density after tape peeling is ID (back), the fixing ratio can be calculated by the following formula 2.
Formula 2:
Fixing rate (= fixing strength) (%) = (ID (back) / ID (front)) × 100
Here, the density was adjusted so that the reflection density of the printed matter before tape peeling was 1.30 ± 0.01. In addition, the tape peeling operation is a method in which an adhesive tape (manufactured by Sumitomo 3M, trade name: Scotch Mending Tape 810-3-18) is applied to the measurement part of a test paper, and a disk-shaped metal roll (diameter 15 cm × thickness 2 cm) , Weight: 1 kg), a series of operations of pressing and adhering at a constant pressure and then peeling the adhesive tape in a direction along the paper at a constant speed. The image density was measured using a reflection type image densitometer (manufactured by Macbeth, trade name: RD914).
In this fixing test, the fixing rate was defined as fixing strength.

7-2. Print Density Using the above printer, after adjusting the printer so that the amount of cyan toner on the paper surface of the solid image is 0.37 (mg / cm ² ), the temperature of the fixing roll (fixing temperature) is set to 170 to 200. By changing the temperature to 0 ° C., a solid image of 5 cm square was printed on plain paper for copying machines (80 g / m ² ). The obtained 5 cm square solid image was measured using a reflection image densitometer (manufactured by Macbeth, trade name: RD914).

7-3. Gloss After using the above printer and adjusting the printer so that the amount of cyan toner on the paper surface of the solid image is 0.37 (mg / cm ² ), the temperature of the fixing roll (fixing temperature) is set to 170 to 200 ° C. The solid image of 5 cm square was printed on paper (manufactured by HammerMill, trade name “Laser Print Paper 24”). Using the gloss meter (trade name “VGS-SENSOR” manufactured by Nippon Denshoku Industries Co., Ltd.), the gloss value of the obtained solid image of 5 cm square was measured at an incident angle of 60 °. In addition, it shows that there is glossiness, so that the value of gloss is large.

  The compositions of cyan pigment compositions 1 and 2 and copper phthalocyanine derivative pigments 1 and 2 are shown in Table 1, and the compositions, measurement and evaluation results of the cyan toners of Examples 1 to 3 and Comparative Examples 1 and 2 are shown. Table 2 shows the results. In Tables 1 and 2, “PB15: 3” is C.I. I. Pigment Blue 15: 3, “PB17: 1” is C.I. I. Pigment Blue 17: 1 is shown respectively. In Table 2, “cyan colorant” means cyan pigment compositions 1 and 2, copper phthalocyanine derivative pigments 1 and 2, and C.I. I. It is a general term for pigment blue 15: 3 and 17: 1.

8). Summary of Toner Evaluation Hereinafter, cyan toner evaluation will be examined with reference to Tables 1 and 2.
First, the cyan toner of Comparative Example 1 is examined. From Table 2, the cyan toner of Comparative Example 1 is a known cyan pigment, C.I. I. This toner contains only CI Pigment Blue 15: 3 as a cyan colorant.
From Table 2, the cyan toner of Comparative Example 1 has a fixing strength of 92% or higher at a fixing temperature of 180 ° C. or higher. Therefore, for the cyan toner of Comparative Example 1, there is no problem with fixability at least at a relatively high temperature.
However, the cyan toner of Comparative Example 1 has a low fixing strength of 82% at a fixing temperature of 170 ° C. Further, the cyan toner of Comparative Example 1 has a reflection density ID value as low as 1.22 or less at each temperature of 170 to 200 ° C. Further, the cyan toner of Comparative Example 1 has a low gloss value at each temperature of 170 to 200 ° C. In particular, the gloss value of the cyan toner of Comparative Example 1 is less than 50% of the gloss value of Examples 1 to 3 at the corresponding temperatures. Therefore, it can be seen that the cyan toner of Comparative Example 1 has a low fixing strength at a relatively low fixing temperature, a low print density in the entire temperature range of 170 to 200 ° C., and particularly inferior glossiness.

Next, the cyan toner of Comparative Example 2 will be examined. From Table 2, the cyan toner of Comparative Example 2 is a known cyan pigment, C.I. I. This toner contains only CI Pigment Blue 17: 1 as a cyan colorant.
From Table 2, the cyan toner of Comparative Example 2 has a fixing strength of 90% or more at a fixing temperature of 190 ° C. or higher. Therefore, for the cyan toner of Comparative Example 2, there is no problem with fixability at least at a relatively high temperature.
However, the cyan toner of Comparative Example 2 has a low fixing strength of 80% or less at a fixing temperature of 180 ° C. or lower. The cyan toner of Comparative Example 2 has a low reflection density ID value of 1.20 or less at each temperature of 170 to 200 ° C. Further, the cyan toner of Comparative Example 2 has a low gloss value at each temperature of 170 to 200 ° C. In particular, the gloss value of the cyan toner of Comparative Example 2 is less than 50% of the gloss value of Examples 1 to 3 at each corresponding temperature. Therefore, it can be seen that the cyan toner of Comparative Example 2 has a low fixing strength at a relatively low fixing temperature, a low print density in the entire temperature range of 170 to 200 ° C., and particularly inferior glossiness.

On the other hand, the cyan toner of Example 1 contains the cyan pigment composition 1 surface-treated with a copolymer as shown in Tables 1 and 2. Further, from Tables 1 and 2, the cyan toner of Example 2 contains the cyan pigment composition 2 surface-treated with a copolymer. Further, from Tables 1 and 2, the cyan toner of Example 3 contains a copper phthalocyanine derivative pigment 1 that has not been surface-treated with a (co) polymer.
From Table 2, all of the cyan toners of Examples 1 to 3 have a fixing strength as high as 88 or more in the fixing temperature range of 170 to 200 ° C., and the value of the reflection density ID in the temperature range is 1. .25 or higher, and the gloss value in the temperature range is as high as 7.0 or higher.
Therefore, the cyan toner of the present invention in which the cyan colorant contains the copper phthalocyanine derivative pigment represented by the above formula (1) or formula (2) has a high reflection density of printed matter, excellent fixing strength, and a printed surface. It turns out that it becomes smooth and gives a high gloss print.
In addition, among the cyan toners of Examples 1 to 3, in particular, the cyan toners of Example 1 and Example 2 containing the cyan pigment composition 1 or 2 surface-treated with a copolymer are both The fixing strength in the fixing temperature range of 170 to 200 ° C. is as high as 92 or more, the reflection density ID value in the temperature range is as high as 1.30 or more, and the gloss value in the temperature range is 7. 2 or higher.

Claims (6)

A cyan toner containing a binder resin, a release agent and a cyan colorant,
A cyan toner, wherein the cyan colorant contains a copper phthalocyanine derivative pigment represented by the following formula (1) or the following formula (2).

(In the above formulas (1) and (2), CuPc is a copper phthalocyanine residue, and n is an integer of 1 to 4. In the above formula (1), R ¹ and R ² are each independently , An atom or group selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 6 carbon atoms.)   The cyan toner according to claim 1, wherein the cyan colorant contains 1 to 20% by mass of the copper phthalocyanine derivative pigment.   The cyan toner according to claim 1, wherein the release agent contains an ester wax.   The cyan toner according to claim 3, wherein the ester wax is a polyfunctional ester wax having an acid value of 2 mgKOH / g or less and a hydroxyl value of 15 mgKOH / g or less.   The cyan toner according to claim 1, wherein the release agent contains a hydrocarbon wax.   The copper phthalocyanine derivative pigment is surface-treated with a (co) polymer obtained by polymerizing at least one polymerizable monomer selected from the group consisting of styrene and alkyl (meth) acrylate. The cyan toner according to claim 1, wherein the cyan toner is a toner.