JP4434881B2 - toner - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic charge image in an image forming method such as electrophotography or electrostatic printing, or a toner for forming a toner image in a toner jet image forming method, and is particularly formed with toner. The present invention relates to a toner used for a fixing method in which a toner image is fixed to a print sheet such as a transfer material by heating and pressing.

  Conventionally, in order to obtain excellent full-color image reproducibility in image forming methods by electrophotography, electrostatic printing, etc., as a colorant for color toner, in addition to optical characteristics such as hue, coloring power, transparency, light resistance Durability properties such as heat resistance, heat resistance and solvent resistance are required. Therefore, the colorant used is generally preferably a pigment rather than a dye from the viewpoint of durability characteristics, and examples of the yellow pigment include C.I. I. Benzidine-based disazo pigments such as CI Pigment Yellow 12, 13 and 17; I. Condensed azo pigments such as Pigment Yellow 93, 151, 154, and 180 are used.

  However, few of these pigments can satisfy all of the optical characteristics and durability characteristics, and there are merits and demerits, respectively. Furthermore, the pigments used in the toner are limited because they are more expensive than other pigments.

  Therefore, an attempt has been made to use an inexpensive monoazo pigment for the toner, which has a large production amount. The monoazo yellow pigment represented by the general formula (I) has excellent optical properties and sufficient image reproducibility when the primary particle diameter is small. However, it has the disadvantages of poor crystal stability, poor heat resistance and solvent resistance, and aggregation and crystal growth occur in the toner manufacturing process, making it opaque and difficult to use in toner.

  In order to solve these problems, attempts have been made to improve the crystal stability of monoazo pigments. For example, a method of simultaneously producing pigment derivatives similar to the structure of a monoazo pigment at the time of pigment synthesis (see Patent Documents 1 and 2), a method of simultaneously producing two types of monoazo pigments having different structures (see Patent Document 3), and the like.

  However, although improvement is seen in the toner obtained by the kneading pulverization method in the above method, for example, a step of dispersing the pigment composition in an organic solvent, such as a suspension polymerization method or a polymer dissolution suspension method, Furthermore, in the present situation, satisfactory transparency cannot be obtained in a toner having a granulation process or a polymerization process under heating.

Japanese Patent No. 312770 JP 2000-63694 A JP 2001-324837 A

  The present invention has been made in view of the above problems, and suppresses aggregation, crystal growth, and the like in a step of dispersing a monoazo pigment in an organic medium and a granulation (polymerization) step during toner production. An object of the present invention is to provide a toner that can finely disperse a pigment in the toner and has excellent coloring power and transparency.

  As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by mixing a pigment derivative having a specific structure in a desired monoazo pigment at an arbitrary ratio, and have completed the present invention.

  That is, the present invention is as follows.

(1) In the toner containing at least a colorant and a resin, a toner produced by suspension polymerization comprising a step of said toner dispersing the colorant in a polymerizable monomer, the colorant is, A toner comprising at least a monoazo pigment composition in which compounds represented by the following general formulas (I) and (II) are mixed at a molar ratio of 90:10 to 55:45.

（式中、Ｘ₁ 及びＸ ₄ は、ベンゼン環の２位に位置するＯＣＨ ₃ 基、Ｘ ₂ はベンゼン環の４位に位置するＮＯ ₂ 基、Ｘ ₃ ，Ｘ ₅ ，Ｘ ₆ は水素原子を示す。Ｙ ₁ はベンゼン環の２位に位置するＣＯＯＨ基、Ｙ ₄ はベンゼン環の２位に位置するＯＣＨ ₃ 基、Ｙ ₂ ，Ｙ ₃ ，Ｙ ₅ ，Ｙ ₆ は水素原子を示す。）

(Wherein X ₁ and X ₄ are OCH ₃ groups located at the 2-position of the benzene ring , X ₂ is a NO ₂ group located at the 4-position of the benzene ring , and X ₃ , X ₅ and X ₆ are hydrogen atoms. Y ₁ represents a COOH group located at the 2-position of the benzene ring, Y ₄ represents an OCH ₃ group located at the 2-position of the benzene ring , and Y ₂ , Y ₃ , Y ₅ and Y ₆ represent a hydrogen atom .)

  (2) The monoazo pigment composition is characterized in that at least a part of the compound represented by the general formula (II) is contained in the crystal structure of the compound represented by the general formula (I). The toner according to (1).

  (3) The monoazo pigment composition is 90.0 to 55.0 mol% of the compound represented by the general formula (I), and 10.0 to 45.0 of the compound represented by the general formula (II). The toner according to (1) or (2), wherein the toner is synthesized at the same time.

  (4) The monoazo pigment composition comprises a monoazo compound (I) represented by the following general formula (I) and a monoazo compound (II) represented by the general formula (II) in a ratio of 79:21 to 65:35. The toner according to any one of (1) to (3), wherein the toner is a monoazo pigment composition mixed in a molar ratio.

  (5) The toner according to (1) to (4), wherein the monoazo pigment composition is synthesized in the presence of a water-soluble resin or a water-dispersed resin.

  (6) The toner according to (1) to (5), wherein the solvent resistance (toluene warming test) of the monoazo pigment composition is 0.5 or more.

  According to the present invention, a monoazo pigment can be finely dispersed in a toner even after undergoing a dispersion step and a granulation (polymerization) step in an organic medium, and has excellent coloring power and transparency, and is inexpensive and well-balanced. Toner can be provided.

  The present invention is described in further detail below.

  By using the monoazo pigment composition characterized by the present invention described below, the crystal stability of the pigment can be improved, and aggregation and crystal growth are suppressed even when subjected to dispersion and heating in an organic medium, resulting in a monoazo pigment. A toner in which the composition is finely dispersed can be obtained.

Specific examples of the monoazo pigment represented by the monoazo compound (I) include C.I. I. Pigment Yellow1, C.I. I. Pigment Yellow 3, C.I. I. Pigment Yellow 49, C.I. I. Pigment Yellow 65, C.I. I. Pigment Yellow 73, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 98, C.I. I. Pigment Yellow 167, C.I. I. Pigment Yellow 175 and the like. Among these, the monoazo pigment according to the present invention satisfying the substituents X _{1 to} X ₆ in the general formula (I) is C.I. I. Pigment Yellow 74.

  As a method for producing the compound represented by the general formula (I) as described above, an aromatic amino compound having an arbitrary structure represented by the following formula (III) is diazotized as a diazo component, and the following formula: It can be obtained by coupling an acetoacetamide compound having an arbitrary structure represented by (IV) as a coupling component.

（但し、上記式中、Ｘ₁〜Ｘ₆は前記定義の通りである。）

(However, in the above formula, X _{1 to} X ₆ are as defined above.)

  The monoazo pigment composition used in the present invention is characterized by mixing the monoazo compound represented by the general formula (II) in a molar ratio of 90:10 to 55:45 with respect to the above monoazo compound. As a method for producing such a monoazo pigment composition, 10 to 45 mol% of the aromatic amino compound represented by the formula (III) in the method for producing a monoazo pigment described above is represented by the carboxyl represented by the formula (V). Replace with a group-containing aromatic amino compound, or replace 10 to 45 mol% of the acetoacetamide compound represented by formula (IV) with a carboxyl group-containing acetoacetamide compound represented by formula (VI), or both Can be achieved. However, when both are used, the total molar amount of the aromatic amino compound of formula (III) and the acetoacetamide compound of formula (IV), the carboxyl group-containing aromatic amino compound of formula (V) and the carboxyl of formula (VI) The ratio with respect to the total molar amount of the group-containing acetoacetamide compound should be 90:10 to 55:45.

（但し、上記式中、Ｙ₁〜Ｙ₆は前記定義のとおりである。）

(However, in the above formula, Y _{1 to} Y ₆ are as defined above.)

  As mentioned above, the molar ratio of the compounds of formula (I) and formula (II) should be 90:10 to 55:45. When the amount of the compound of the formula (II) is less than 10%, sufficient crystal stability cannot be obtained, and aggregation and crystal growth cannot be suppressed. In order to obtain more remarkable crystal stability, it is preferably 21% or more. However, when the amount of the compound of the formula (II) is too much, it is not preferable to make it 45% or more in order to impair the original color tone and coloring power of the compound of the formula (I). For the above reasons, the molar ratio of the compounds of formula (I) and formula (II) needs to be 90:10 to 55:45, more preferably 79:21 to 55:45, still more preferably, 79: 21-65: 35.

  In order to make the primary particle diameter of the monoazo pigment composition as small as possible and facilitate the fine dispersion, it is preferable that the monoazo pigment composition is produced by coupling in the presence of a water-soluble resin or a water-dispersed resin. The water-soluble resin or water-dispersed resin that can be used in the present invention is not particularly limited, and specific examples include polyester, styrene-acrylic copolymer system, styrene-maleic acid copolymer system, acrylic copolymer system, and alkyd system. And resins having hydrophilic groups such as epoxy, urethane, and hybrids thereof.

  By the above method, the crystal stability of the monoazo pigment composition can be improved, and as a result, the degree of solvent resistance can be made 0.5 or more. When the solvent resistance system is less than 0.5, when the monoazo pigment composition is dispersed in an organic medium and further heated, the influence of aggregation, crystal growth, etc. appears remarkably and it cannot be finely dispersed in the toner. . The method for measuring the solvent resistance in the present invention follows the method described later.

  In order to uniformly disperse the monoazo pigment composition in the toner, the surface hydrophobicity is preferably 2.0 or more. When the surface hydrophobicity is less than 2.0, the pigment is agglomerated in the granulation (polymerization) step or localized on the surface of the toner particles, resulting in a loss of transparency. The procedure for measuring the surface hydrophobicity referred to in the present invention follows the method described later.

  As a method for setting the surface hydrophobicity to 2.0 or more, a known surface treating agent can be used. For example, it can adjust by using 1-15 mass parts of surface treatment agents, such as surfactant, fatty acid ester, oil, a silane coupling agent, and rosin with respect to 100 mass parts of monoazo pigment compositions.

  The method for producing the toner of the present invention preferably includes a polymer dissolution suspension method, suspension polymerization method, dispersion polymerization method, etc., but the effects of the present invention are more apparent when the polymer dissolution suspension method or It is a suspension polymerization method.

  In the toner production method using the polymer dissolution suspension method, first, the binder resin and the pigment composition are dissolved and dispersed in an organic medium, and then uniformly dissolved with a stirrer etc. together with wax and other additives as required. A liquid mixture for toner formation is prepared by mixing or dispersing. In that case, a colorant, wax, or other additives previously melt-kneaded may be added to the organic medium. The liquid mixture thus obtained is added to a dispersion medium (preferably an aqueous medium) containing a dispersion stabilizer, and a toner is prepared using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser as a stirrer. Disperse and suspend to the particle size (granulation step). Then, the organic solvent used to dissolve the binder is removed by heating or reduced pressure, and the organic solvent is completely removed by adding a solvent such as methanol, ethanol, 1-propanol, t-butyl alcohol, acetone, etc. Toner particles can be obtained.

  In the toner production method by suspension polymerization, first, the pigment composition is treated with a disperser using a polymerizable monomer constituting a resin as a toner binder as a dispersion medium to obtain a pigment dispersion paste. The obtained pigment dispersion paste is uniformly dissolved and mixed or dispersed with a stirrer or the like together with a polymerizable monomer and a polymerization initiator, and further with wax and other additives as required, to prepare a monomer composition. . The monomer composition thus obtained is added to a dispersion medium (preferably an aqueous medium) containing a dispersion stabilizer, and a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser is used as a stirrer. Then, it is finely dispersed to the toner particle diameter (granulation step). Then, the monomer composition finely dispersed in the polymerization step is polymerized by light or heat to obtain toner particles.

  The organic medium that can be used in the polymer dissolution suspension method is determined according to the toner binder and is not particularly limited. Specifically, ether alcohols such as methyl cellosolve, cellosolve, isopropyl cellosolve, butyl cellosolve, diethylene glycol, monobutyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone; ethyl acetate, butyl acetate, ethyl propionate, cellosolve acetate, etc. Esters; hydrocarbons such as hexane, octane, petroleum ether, cyclohexane, benzene, toluene, xylene; halogenated hydrocarbons such as trichloroethylene, dichloromethane, chloroform; ethers such as ethyl ether, dimethyl glycol, trioxane tetrahydrofuran; Acetals such as methylal and diethyl acetal; containing sulfur and nitrogen such as nitropropene, nitrobenzene and dimethyl sulfoxide Selected from compounds, and the like.

  The polymerizable monomer that can be used in the present invention as a dispersion medium in the suspension polymerization method is an addition polymerization or condensation polymerization monomer. Preferably, it is an addition polymerization monomer. Specifically, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2 , 4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, p- Styrene such as n-dodecylstyrene and derivatives thereof; Ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; Unsaturated polyenes such as butadiene and isoprene; Vinyl chloride, vinylidene chloride, vinyl bromide and vinyl iodide Vinyl halides such as vinyl acetate, vinyl propionate, benzoic acid Vinyl esters such as Nyl; methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylate-n-octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate Α-methylene fatty acid monocarboxylic acid esters such as diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, acrylic acid-n-butyl, acrylic acid isobutyl, propyl acrylate, acrylic acid-n-octyl, dodecyl acrylate Acrylates such as 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, etc .; vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl Examples thereof include vinyl ethers such as tilether; N-vinyl compounds such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; vinyl naphthalenes; acrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide.

  As a method of dispersing the pigment composition in the organic medium, a known method can be used. For example, if necessary, a resin and a pigment dispersant are dissolved in an organic medium, and the pigment powder is gradually added while being stirred, so that the solvent is sufficiently blended. Further, by applying mechanical shearing force with a dispersing machine such as a ball mill, paint shaker, dissolver, attritor, sand mill, or high speed mill, the pigment can be stably finely dispersed, that is, dispersed into uniform fine particles.

  The resin as a toner binder used in the polymer dissolution suspension method is not particularly limited. For example, styrene resin, acrylic resin, styrene-acrylic resin, polyethylene resin, polyethylene-vinyl acetate resin, vinyl acetate resin, polybutadiene resin, phenol resin, polyurethane resin, polybutyral resin, polyester resin, and the like can be given. Among these, styrenic resins, acrylic resins, styrene-acrylic resins, polyester resins, and the like are desirable in terms of toner characteristics.

  As the polymerizable monomer constituting the resin as the toner binder used in the suspension polymerization method, those similar to the specific examples of the polymerizable monomer can be used.

  The toner of the present invention contains at least the monoazo pigment composition described above, but other colorants may be used in combination. Known pigments and dyes can be used as the colorant. The addition amount of the colorant is preferably 3 to 20 parts by mass per 100 parts by mass of the binder resin or polymerizable monomer.

  The aqueous dispersion medium that can be used in the above production method is mainly determined from the solubility of the toner binder, the organic medium, the monomer, and the polymer. Specifically, for example, water; methyl alcohol, ethyl alcohol, modified ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol, octyl Alcohols such as alcohol, benzyl alcohol and cyclohexanol; ether alcohols such as methyl cellosolve, cellosolve, isopropyl cellosolve, butyl cellosolve and diethylene glycol monobutyl ether; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethyl acetate, butyl acetate and propion Esters such as ethyl acetate and cellosolve acetate; hexane, octane, cyclohexane, benzene, toluene, xyl Hydrocarbons such as ethylene; ethers such as ethyl ether and ethylene glycol; acetals such as methylal and diethyl acetal; acids such as formic acid, acetic acid and propionic acid; nitropropene, nitrobenzene, dimethylamine, monoethanolamine, pyridine, It is selected from sulfur and nitrogen-containing organic compounds such as dimethyl sulfoxide and dimethylformamide, with water or alcohols being particularly preferred. Two or more of these solvents can be mixed and used. The density | concentration of the liquid mixture with respect to a dispersion medium is 1-80 mass% of monomers with respect to a dispersion medium, Preferably it is 10-65 mass%.

  As the toner particle dispersion stabilizer that can be used in the granulation step in an aqueous dispersion medium, known ones can be used. As specific examples, as inorganic compounds, calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like. As the organic compound, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salt, starch and the like can be dispersed in an aqueous phase. The concentration of the dispersion stabilizer is preferably 0.2 to 20% by mass with respect to 100% by mass of the monomer.

  Examples of the polymerization initiator used in the toner of the present invention using the suspension polymerization method include known polymerization initiators. Specifically, as a polymerization initiator, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1) Carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo or diazo polymerization initiators such as azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate , Cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis (4,4-t-butylperoxycyclohexyl) propane , Tris- (t-butylpe Macroinitiator having oxy) triazine such as peroxide initiators and peroxide in the side chain; potassium persulfate, such as ammonium persulfate persulfate; hydrogen peroxide, etc.

  Examples of radical polymerizable tri- or higher functional polymerization initiators include tris (t-butylperoxy) triazine, vinyltris (t-butylperoxy) silane, 2,2-bis (4,4-di-t-butylperoxide. Oxycyclohexyl) propane, 2,2-bis (4,4-di-t-amylperoxycyclohexyl) propane, 2,2-bis (4,4-di-t-octylperoxycyclohexyl) propane, 2,2 And radical polymerizable polyfunctional polymerization initiators such as -bis (4,4-di-t-butylperoxycyclohexyl) butane. The concentration of the polymerization initiator is preferably from 0.1 to 20 mass%, more preferably from 0.1 to 10 mass%, based on the monomer.

  Examples of the chain transfer agent used in the toner of the present invention using the suspension polymerization method include known chain transfer agents.

  Furthermore, in the present invention, for the purpose of imparting various properties to the toner, the following toner additives may be used.

  In order to stabilize the frictional charging characteristics of the toner, a charge control agent may be included. In this case, a charge control agent that has a high toner charging speed and can stably maintain a constant charge amount is preferable. When a toner is produced by a polymerization method, it is particularly preferable to use a charge control agent that does not have polymerization inhibitory properties. Specifically, as the negative control agent, salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid and other metal compounds; sulfonic acid, polymer type compound having carboxylic acid in the side chain; boron compound; urea Compound; silicon compound; calixarene and the like are preferable. The positive control agent is preferably a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, or the like. These charge control agents are preferably added in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  In the toner of the present invention, known additives such as a fluidity imparting agent, an abrasive, a lubricant, and charge control particles may be externally added to the toner particles.

  As the fluidity-imparting agent, metal oxides (silicon oxide, aluminum oxide, titanium oxide, etc.) are preferably used. These are more preferably subjected to a hydrophobic treatment. As polishing agents, metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metal salts (calcium sulfate, barium sulfate, etc.) , Calcium carbonate, etc.) are preferably used. As the lubricant, fluorine resin powder (vinylidene fluoride, polytetrafluoroethylene, etc.) and fatty acid metal salts (zinc stearate, calcium stearate, etc.) are preferably used. As the charge controllable particles, metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide, etc.), carbon black and the like are preferably used.

  These additives are used in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of toner particles. These additives may be used alone or in combination.

  The toner of the present invention can be used as a one-component developer composed only of toner, or can be used as a two-component developer by mixing with a carrier.

The solvent resistance in the present invention refers to a numerical value obtained by the following procedure.
1) Put 1.5 g of a sample into a 50 ml glass bottle, add 20 ml of toluene and 25 g of glass beads, and disperse with a paint shaker for 1 hour.
2) Heat the glass bottle to 60 ° C. and leave it for 1 hour.
3) The obtained pigment dispersion paste is uniformly applied to a slide glass with a wire bar, and then naturally dried.
4) The transmission spectrum of the obtained slide glass is measured with a spectrophotometer and calculated by the following equation.
Solvent resistance = (520 nm transmittance−450 nm transmittance) / 700 nm transmittance

The surface hydrophobicity referred to in the present invention refers to a value obtained by the following procedure.
1) Put 0.2 g of sample into a 100 ml beaker and add 50 ml of pure water.
2) While stirring with a magnetic stirrer, IPA (isopropyl alcohol) is dropped under the liquid level.
3) The end point is the point at which the sample is completely wetted and the sample cannot be found on the liquid surface.
4) The amount of IPA (ml) added up to the end point is defined as the surface hydrophobicity.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, all the parts used in an Example show a mass part.

<Production Example 1 of Monoazo Pigment Composition>
155.3 g of 2-nitro-4-chloro-aniline and 27.4 g of 4-carboxyaniline are added to a mixture of 600 g of water and 1000 g of 10% hydrochloric acid and stirred, then cooled to 0 ° C. and 75 g of sodium nitrite In 100 g is added dropwise over 30 minutes and stirred for 30 minutes to diazotize. To this, excess nitrous acid was eliminated with sulfamic acid, followed by filtration to obtain a diazo solution. Separately, 211.5 g of 2-chloroacetoacetanilide is added to 5000 g of water, 48 g of sodium hydroxide is added and dissolved, and then precipitated by adding a mixture of 120 g of acetic acid and 120 g of water to obtain a coupling component suspension. did. The diazo solution was added dropwise to the coupling component suspension adjusted to 15 ° C. over 90 minutes, and the mixture was further stirred for 30 minutes to complete the coupling reaction. Next, 18.5 g of soybean oil is added as a hydrophobizing agent, stirred for 30 minutes, heated to 90 ° C., aged with stirring for 30 minutes, filtered and washed to remove by-product salts and the like. The pigment cake was loosened and dried at 40 ° C. with a vacuum dryer to obtain a monoazo yellow pigment composition 1 (yield 398.3 g).

<Production Example 2 of Monoazo Pigment Composition>
152 g of 2-nitro-4-methyl-aniline was added to a mixture of 600 g of water and 1000 g of 10% hydrochloric acid, stirred, then cooled to 0 ° C., and dissolved in 100 g of sodium nitrite in 100 g over 30 minutes. Then, the mixture is stirred for 30 minutes and diazotized. To this, excess nitrous acid was eliminated with sulfamic acid, followed by filtration to obtain a diazo solution. Separately, 115.1 g of acetoacetanilide and 77.4 g of 2-carboxyacetoacetanilide are added to 5000 g of water, 48 g of sodium hydroxide is added and dissolved, then water-dispersed polyester (Eastman Chemical Co., Eastek 2140) After adding 200 g of a 20% aqueous dispersion, precipitation was performed by adding a mixture of 120 g of acetic acid and 120 g of water to obtain a coupling component suspension. The diazo solution was added dropwise to the coupling component suspension adjusted to 15 ° C. over 90 minutes, and the mixture was further stirred for 30 minutes to complete the coupling reaction. Next, 35 g of rosin is added as a hydrophobizing agent, stirred for 30 minutes, heated to 90 ° C., aged with stirring for 30 minutes, filtered, washed with water to remove by-product salts, etc. After being loosened, it was dried at 40 ° C. with a vacuum dryer to obtain a monoazo yellow pigment composition 2 (yield 345.1 g).

<Production Example 3 of Monoazo Pigment Composition>
142.8 g of 2-methoxy-4-nitro-aniline and 20.6 g of anthranilic acid are added to a mixture of 600 g of water and 1000 g of 10% hydrochloric acid and stirred, then cooled to 0 ° C. and 100 g of sodium nitrite 75 g The solution dissolved in is added dropwise over 30 minutes and stirred for 30 minutes to diazotize. To this, excess nitrous acid was eliminated with sulfamic acid, followed by filtration to obtain a diazo solution. Separately, 207.0 g of 2-methoxyacetoacetanilide was added to 5000 g of water, 48 g of sodium hydroxide was added and dissolved, and then 200 g of 20% aqueous dispersion of water-dispersed polyester (Eastman Chemical Co., Eastek 1100) was added. The mixture was precipitated by adding a mixture of 120 g of acetic acid and 120 g of water to obtain a coupling component suspension. The diazo solution was added dropwise to the coupling component suspension adjusted to 15 ° C. over 90 minutes, and the mixture was further stirred for 30 minutes to complete the coupling reaction. Next, 18.0 g of methyl stearate as a hydrophobizing agent was added and stirred for 30 minutes, heated to 90 ° C., aged with stirring for 30 minutes, filtered, washed with water to produce by-product salts, etc. After removing and loosening the pigment cake, it was dried at 40 ° C. with a vacuum dryer to obtain a monoazo yellow pigment composition 3 (yield 390.5 g).

<Production Example 4 of Monoazo Pigment Composition>
126.0 g of 2-methoxy-4-nitro-aniline and 34.3 g of anthranilic acid are added to a mixture of 600 g of water and 1000 g of 10% hydrochloric acid and stirred, then cooled to 0 ° C. and 100 g of sodium nitrite 75 g The solution dissolved in is added dropwise over 30 minutes and stirred for 30 minutes to diazotize. To this, excess nitrous acid was eliminated with sulfamic acid, followed by filtration to obtain a diazo solution. Separately, 207.0 g of 2-methoxyacetoacetanilide was added to 5000 g of water, 48 g of sodium hydroxide was added and dissolved, and then 200 g of 20% aqueous dispersion of water-dispersed polyester (Eastman Chemical Co., Eastek 1100) was added. The mixture was precipitated by adding a mixture of 120 g and 120 g of acetic acid to obtain a coupling component suspension. The diazo solution was added dropwise to the coupling component suspension adjusted to 15 ° C. over 90 minutes, and the mixture was further stirred for 30 minutes to complete the coupling reaction. Next, 18.0 g of methyl stearate as a hydrophobizing agent was added and stirred for 30 minutes, heated to 90 ° C. and aged with stirring for 30 minutes, then filtered and washed with water to form by-product salts, etc. After removing and loosening the pigment cake, it was dried at 40 ° C. with a vacuum dryer to obtain a monoazo yellow pigment composition 4 (yield 388.9 g).

<Production Example 5 of monoazo pigment composition>
159.6 g of 2-methoxy-4-nitro-aniline and 6.9 g of anthranilic acid are added to a mixture of 600 g of water and 1000 g of 10% hydrochloric acid and stirred, then cooled to 0 ° C. and 100 g of sodium nitrite 75 g The solution dissolved in is added dropwise over 30 minutes and stirred for 30 minutes to diazotize. To this, excess nitrous acid was eliminated with sulfamic acid, followed by filtration to obtain a diazo solution. Separately, 207.0 g of 2-methoxyacetoacetanilide was added to 5000 g of water, 48 g of sodium hydroxide was added and dissolved, and then 200 g of 20% aqueous dispersion of water-dispersed polyester (Eastman Chemical Co., Eastek 1100) was added. The mixture was precipitated by adding a mixture of 120 g of acetic acid and 120 g of water to obtain a coupling component suspension. The diazo solution was added dropwise to the coupling component suspension adjusted to 15 ° C. over 90 minutes, and the mixture was further stirred for 30 minutes to complete the coupling reaction. Next, 18.0 g of methyl stearate as a hydrophobizing agent was added and stirred for 30 minutes, heated to 90 ° C., aged with stirring for 30 minutes, filtered, washed with water to produce by-product salts, etc. After removing and loosening the pigment cake, it was dried at 40 ° C. with a vacuum dryer to obtain a monoazo yellow pigment composition 5 (yield 390.3 g).

<Production Example 6 of Monoazo Pigment Composition>
168.0 g of 2-methoxy-4-nitro-aniline was added to and stirred in a mixture of 600 g of water and 1000 g of 10% hydrochloric acid, then cooled to 0 ° C., and 30 g of sodium nitrite dissolved in 100 g was cooled to 30 g. The solution is dropped over a period of time and stirred for 30 minutes to diazotize. To this, excess nitrous acid was eliminated with sulfamic acid, followed by filtration to obtain a diazo solution. Separately, 207.0 g of 2-methoxyacetoacetanilide was added to 5000 g of water, 48 g of sodium hydroxide was added and dissolved, and then 200 g of 20% aqueous dispersion of water-dispersed polyester (Eastman Chemical Co., Eastek 1100) was added. The mixture was precipitated by adding a mixture of 120 g of acetic acid and 120 g of water to obtain a coupling component suspension. The diazo solution was added dropwise to the coupling component suspension adjusted to 15 ° C. over 90 minutes, and the mixture was further stirred for 30 minutes to complete the coupling reaction. Next, 18.0 g of methyl stearate as a hydrophobizing agent was added and stirred for 30 minutes, heated to 90 ° C. and aged with stirring for 30 minutes, then filtered and washed with water to form by-product salts, etc. After removing and loosening the pigment cake, it was dried at 40 ° C. with a vacuum dryer to obtain a monoazo yellow pigment composition 6 (yield 391.0 g).

なお、表１は一般式（Ｉ）及び（ＩＩ）の化合物中のＸ₁〜Ｘ₆及びＹ₁〜Ｙ₆に対応する官能基を示しており、例えば、Ｘ₁＝２−ＮＯ₂とは、Ｘ₁としてベンゼン環の２位の位置にＮＯ₂基を有することを意味する。

Incidentally, Table 1 shows the general formula (I) and the corresponding functional groups X ₁ to X ₆ and Y ₁ to Y ₆ in the compound of (II), for example, the X ₁ = _2-NO 2 is , X ₁ means having a NO ₂ group at the 2-position of the benzene ring.

< Reference Example 1>
After thoroughly premixing 320 parts of the styrene monomer and 20 parts of the monoazo yellow pigment composition 1 in a container, it was dispersed in a bead mill for 1 hour while maintaining it at 20 ° C. or lower to prepare a pigment dispersion paste.

The 0.1M-Na ₃ PO ₄ aqueous solution 450 parts was charged into ion-exchanged water 710 parts After warming to 60 ° C., and stirred at 11,000rpm using a TK-type homomixer (manufactured by Tokushu Kika Kogyo) . To this, 70 parts of a 1.0 M CaCl ₂ aqueous solution was gradually added to obtain a dispersion medium containing Ca ₃ (PO ₄ ) ₂ .

Pigment dispersion paste 1 170 parts n-butyl acrylate 40 parts paraffin wax (mp 75 ° C) 25 parts styrene-methacrylic acid-methyl methacrylate copolymer 10 parts di-tert-butylsalicylic acid metal compound 3 parts These were heated to 60 ° C., dissolved and dispersed to obtain a monomer mixture. Further, while maintaining at 60 ° C., 10 parts of 2,2′-azobisisobutyronitrile as a polymerization initiator was added and dissolved to prepare a monomer composition.

The monomer composition was charged into the dispersion medium prepared in the 2-liter flask of the homomixer. The monomer composition was granulated by stirring at 60 ° C. for 20 minutes at 10,000 rpm using a TK homomixer in a nitrogen atmosphere. Thereafter, the mixture was reacted at 60 ° C. for 5 hours while stirring with a paddle stirring blade, and then stirred at 80 ° C. for 5 hours to complete the polymerization. After cooling to room temperature, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) _2, and the toner particles 1 were obtained by filtration, washing with water and drying.

< Reference Example 2, Examples 1 and 2 >
Toner particles 2, 3 and 4 were obtained in the same manner except that the monoazo yellow pigment compositions 2 to 4 were used instead of the monoazo yellow pigment composition 1 of Reference Example 1.

<Comparative Examples 1 and 2>
Toner particles 5 and 6 were obtained in the same manner except that the monoazo yellow pigment composition 5 or 6 was used instead of the monoazo yellow pigment composition 1 of Reference Example 1.

The thus prepared monoazo pigment compositions 1-6, Reference Examples 1 and 2, and Examples 1 and 2 and Comparative Examples 1 and 2 were tested as follows.

[Test of monoazo pigment composition]
(A) Volume average particle size: The particle size distribution of the sample was measured using MicrotracUPA (manufactured by Nikkiso Co., Ltd.) to determine the volume average particle size.
(B) Degree of solvent resistance: According to the procedure in the previous period, the transmission spectrum was measured by a toluene heating test using a spectrophotometer U-3300 (manufactured by Hitachi, Ltd.) to obtain the degree of solvent resistance.
(C) Hydrophobicity: It was determined by IPA enemy test according to the above procedure.

[Evaluation of physical properties of toner particles]
(A) Volume average particle diameter: It was determined using a Coulter counter Multisizer II (manufactured by Coulter). As the electrolyte, ISTON R-II (manufactured by Coulter Scientific Japan) was used.
(B) Glass transition point (Tg): Performed according to ASTM (D3418-82) using DSC-7 (Perkin Elmer) at a heating rate of 10 ° C./min. From the DSC curve when the temperature was increased, the end point of the endothermic peak was defined as Tg.

[Production and evaluation of developer]
Each toner particle was prepared by externally adding 0.7 part of hydrophobic silica having a specific surface area of 200 m ² / g by BET method to 100 parts of each obtained toner particle. 7 parts of these toners were mixed with 93 parts of a ferrite carrier having a particle diameter of 45 μm and surface-coated with a styrene-methyl methacrylate copolymer to prepare each developer.

  The following modification disclosed in Japanese Patent Application Laid-Open No. 6-301242 was made to the Canon full color copier CLC-500. The distance between the developing unit and the photosensitive drum was 400 μm, and the peripheral speed ratio between the developing sleeve and the photosensitive drum was 1.3: 1. In the developing device, the magnetic field strength of the developing pole was 1000 Oersted, the alternating electric field was 2000 Vpp, the frequency was 3000 Hz, and the distance between the developing sleeve and the photosensitive drum was 500 μm.

  Images were printed on the CLC-500 modified machine using each developer. The development conditions were a development contrast of 300 V in an environment of temperature 23 ° C./humidity 60% RH. An image was printed on plain paper to evaluate the coloring power, and an image was similarly printed on an overhead projector (OHP) sheet, and the transparency was evaluated by projecting with OHP.

The visual evaluation of the image is as follows.
5: Appears in a very bright yellow color, has excellent coloring power or transparency, and is excellent as a color toner.
4: Appears in a clear yellow color, has sufficient coloring power or transparency, and can be used as a color toner.
3: Slightly shaded in color, coloring power or transparency is not sufficient, but no problem in practical use.
2: It becomes reddish yellow, coloring power or transparency is poor, and cannot be used as a color toner.
1: It turns brown and the coloring power or transparency is inferior and cannot be used as a color toner.

  The above test results are summarized in Table 2 below.

Claims (6)

In a toner containing at least a colorant and a resin, the toner is a toner produced by a suspension polymerization method having a step of dispersing the colorant in a polymerizable monomer , and the colorant has the following general formula A toner comprising at least a monoazo pigment composition in which the compounds represented by (I) and (II) are mixed in a molar ratio of 90:10 to 55:45.

(Wherein X ₁ and X ₄ are OCH ₃ groups located at the 2-position of the benzene ring , X ₂ is a NO ₂ group located at the 4-position of the benzene ring , and X ₃ , X ₅ and X ₆ are hydrogen atoms. Y ₁ represents a COOH group located at the 2-position of the benzene ring, Y ₄ represents an OCH ₃ group located at the 2-position of the benzene ring , and Y ₂ , Y ₃ , Y ₅ and Y ₆ represent a hydrogen atom .)   2. The monoazo pigment composition, wherein at least a part of the compound represented by the general formula (II) is contained in the crystal structure of the compound represented by the general formula (I). The toner described in 1.   The monoazo pigment composition comprises 90.0 to 55.0 mol% of the compound represented by the general formula (I) and 10.0 to 45.0 mol% of the compound represented by the general formula (II). The toner according to claim 1, wherein the toner is synthesized at the same time.   4. The monoazo pigment composition according to claim 1, wherein the compounds represented by the general formulas (I) and (II) are mixed in a molar ratio of 79:21 to 65:35. Toner.   The toner according to claim 1, wherein the monoazo pigment composition is synthesized in the presence of a water-soluble resin or a water-dispersed resin.   6. The toner according to claim 1, wherein the monoazo pigment composition has a solvent resistance (toluene warming test) of 0.5 or more.