JP2008065299A - Toner for electrostatic latent image development, image forming method and method for evaluating the toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a melt kneaded toner for electrostatic latent image development in which the dispersibility of a colorant is excellent and an image forming method. <P>SOLUTION: The toner is obtained by heating and kneading toner materials including a binder resin, a colorant, a charge control agent and a compound represented by general formula (1). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner for developing an electrostatic latent image used for image formation in a copying machine, a printer, a facsimile, and the like, and an image forming method using the toner. The present invention also relates to a method for evaluating the dispersion state of the wax contained in the toner.

  In recent years, the development of electrophotography has been remarkable and widely used in image forming units such as copying machines, printers, and facsimiles. The reason for this is that high-quality images can be formed at high speed, and that analog images as well as color images and digital images can be formed, and that the degree of completeness is high and the stability and durability of performance are high. However, the demand for higher image quality for this method is strong, and further improvement is required. As the countermeasure, the most effective measure is to make the toner used as small as possible and to narrow the particle size distribution as much as possible.

  The electrophotographic color toner used for forming such a color image is generally constituted by dispersing a dye or pigment for coloring in a binder resin, but it is not easy to make the colorant fine particles. Even if the particles are pulverized to the secondary particles, they are easily re-agglomerated and coarsened to secondary particles. In addition, metal chelate pigments are often used as color toner colorants. In metal chelate pigments, dyes that act as ligands are coordinated by surrounding metal in bidentate, tridentate, and tetradentate, and pigmentation proceeds. However, although the light fastness increases, there is a problem that the color of the pigment becomes cloudy due to the broad light absorption. Further, the metal chelate pigment has a problem in that the toner adheres to the surface of the rotary heating member of the fixing device at the time of heat fixing and contaminates the rotary heating member.

  As prior art for such a problem, the inventions disclosed in Patent Documents 1 to 4 are known. For example, Patent Document 1 can produce a fine pigment that is not easily affected by heat during salt milling by using a naphthol pigment mixed with a coupler or base having an acidic group during salt milling. (Patent Document 1, paragraph 0055). Further, Patent Document 2 describes that even when naphthol AS dye is used as a colorant for a polymerized toner, it is possible to provide a toner that does not change in color during heat fixing (paragraph 0159 of Patent Document 2). ).

  Furthermore, Patent Document 3 describes that in a toner using a pigment-based colorant, the dispersibility of the pigment can be improved without using a low-boiling organic solvent (Patent Document 3). Paragraph 0043). Further, Patent Document 4 describes the state of dispersion of the colorant in the toner particles by allowing a specific metal phthalocyanine and a specific polymer ligand capable of coordinating with the metal phthalocyanine to coexist in the toner. It is described that a significantly improved toner can be obtained (paragraph 0030 of Patent Document 4).

  On the other hand, from the viewpoint of the environment, there is an increasing demand for multifunctional toners including a release agent such as oilless toners in order to promote low-temperature fixing. However, the influence of the dispersibility of the release agent, such as the size of the wax particles, is large. When the wax particles are about 4 μm in size, there are many toner particles in which the wax particles are not added internally. Particles may be mixed, and quality problems such as filming may occur. Therefore, in order to obtain a toner having excellent low-temperature fixability, a means for evaluating the size and dispersion state of the wax particles contained in the kneaded product is necessary.

As a prior art regarding such a problem, there are inventions disclosed in Patent Documents 5 to 7. For example, Patent Document 1 describes a method in which a toner after kneading and pulverization is placed on a heating plate, heated from below and observed with a television camera (paragraphs 0016 to 0017 in Patent Document 5). Further, in Patent Document 6, the micro Vickers hardness of the solid material obtained by melting and kneading the toner raw material and then cooling and solidifying has a correlation with the pulverization property. By defining the hardness, the solid material can be easily reduced to a small particle size. It is described that it can be crushed (paragraphs 0031 to 0032 of Patent Document 6). Further, Patent Document 7 discloses that after electrostatic charge image developing toner containing at least a colorant, wax, and binder resin is neutralized, the toner surface is further charged to a surface potential of an absolute value of 300 to 2,000 V. A method for evaluating the dispersibility of the wax in the toner by measuring a thermally stimulated current in the temperature rising process by a contact method in which the toner is brought into contact is described (eg, 0053 of Patent Document 7).
Japanese Patent No. 3550969 JP 2002-99116 A JP 2003-98747 A JP 2004-295117 A Japanese Patent Laid-Open No. 05-23320 JP 2002-268276 A Japanese Patent Laying-Open No. 2005-043851

  The present invention has been made in view of the above problems, and is a toner for developing an electrostatic latent image obtained by containing a compound represented by the following general formula (1) in a toner raw material mixture, and an image using the toner. The object is to provide a forming method.

  Another object of the present invention is to provide a method for evaluating the dispersion state of the wax contained in the toner, thereby providing a toner that is less likely to adhere to the heating member during heat fixing.

  In order to achieve such an object, the invention according to claim 1, after cooling a kneaded material obtained by heating and kneading a toner raw material mixture having at least a binder resin, a colorant, and a charge control agent, A toner for developing an electrostatic latent image obtained by microparticulation, wherein the toner raw material mixture contains a compound represented by the following general formula (1).

  According to a second aspect of the present invention, in the electrostatic latent image developing toner according to the first aspect, the binder resin is a polyester resin.

  According to a third aspect of the invention, in the electrostatic latent image developing toner according to the first or second aspect, the colorant is at least one of phthalocyanine or metal phthalocyanine.

  According to a fourth aspect of the present invention, in the electrostatic latent image developing toner according to the first or second aspect, the colorant is carbon black.

  According to a fifth aspect of the present invention, the toner for developing an electrostatic latent image according to any one of the first to fourth aspects further includes an external additive.

  According to the sixth aspect of the present invention, a toner image obtained by developing an electrostatic latent image formed on an electrostatic latent image carrier with toner is recorded with or without an intermediate transfer member. An image forming method of transferring onto a material and thermally fixing the toner image on the recording material by a heating and pressing means, wherein the toner described in claim 5 is used.

  The invention according to claim 7 is obtained by heating and kneading a toner raw material mixture having at least a binder resin, a colorant, a wax, and a charge control agent in the method for evaluating a toner for developing an electrostatic latent image. After cooling the kneaded product, the toner for developing an electrostatic latent image obtained by microparticulation is molded to a predetermined pressure density, the molded product is attached to a rheometer, and the temperature is raised to a melt outflow temperature under a load. The ratio of the area occupied by the wax component on the surface of the core melt that has flowed out of the core is measured.

The invention of claim 8, wherein, in the electrostatic latent image evaluation method of developing toner according to claim 7, the load exerted on the molded article, characterized in that it is a 5kgf / cm ² ~30kgf / cm ² .

  The invention according to claim 9 is the method for evaluating a toner for developing an electrostatic latent image according to claim 7 or 8, wherein the rate of temperature rise is 3 ° C./min to 5 ° C./min. .

  According to a tenth aspect of the present invention, in the method for evaluating a toner for developing an electrostatic latent image according to any one of the seventh to ninth aspects, the core melt after flowing out of the thin tube has a diameter after cooling of 0. .5 mm to 0.7 mm.

  According to the eleventh aspect of the present invention, the electrostatic latent image developing toner is caused to flow out in the range of 92 ° C. to 117 ° C. using the evaluation method according to any one of the seventh to tenth aspects. The ratio of the area occupied by the wax component on the surface of the core melt is 50% to 90%.

  According to the twelfth aspect of the present invention, the electrostatic latent image developing toner is caused to flow out in the range of 92 ° C. to 117 ° C. using the evaluation method according to any one of the seventh to tenth aspects. The glossiness of the core melt is 20% or less.

  The invention described in claim 13 is the electrostatic latent image developing toner according to claim 11 or 12, wherein the toner raw material mixture further contains a compound represented by the following general formula (1). To do.

In the present invention, the powdered toner is weighed to a constant weight molded at a pressure density of 0.642 ± 0.100 g / ml, heated to a starting temperature at a predetermined heating rate under a predetermined load, and then discharged. The obtained melt was cooled, a die diameter having a diameter within a predetermined range was selected, a plurality of sample surfaces were collected with a microtome from the air cooled sample, stained with ruthenium oxide, and photographed with SEM or TEM. The invention also includes an invention for a toner for electrophotography, wherein the toner occupies an area occupied by wax in the range of 60 to 90%. Such toner is preferably the toner according to any one of claims 1 to 6. Furthermore, the present invention is preferably the predetermined load is ^{5kgf / cm 2 ~30kgf / cm 2} , also preferably the predetermined heating rate is 3 ℃ / min~5 ℃ / min, the predetermined The die diameter in the range is preferably 0.5 mm to 0.7 mm.

  According to the present invention, it is possible to provide a toner for developing an electrostatic latent image that has excellent dispersibility of a colorant, does not cause toner fixation to a heating member, and has high color tone stability, and an image forming method using the toner. it can. In addition, according to the present invention, it is possible to provide a method for evaluating the dispersion state of the wax contained in the toner, thereby providing a toner that is excellent in wax dispersion and that does not cause the toner to adhere to the heating member. can do.

  In the present embodiment, the toner obtained by the melt-kneading method provides a toner having excellent dispersibility of the colorant and capable of obtaining a high-quality image. Further, in heat fixing, the toner to the rotating heating member of the fixing device An object of the present invention is to provide a toner that does not cause fixation and has high color stability before and after fixing, and an image forming method using the toner. Furthermore, the present embodiment provides a method for evaluating the dispersion state of the wax contained in the toner, thereby providing a toner that is less likely to adhere to the heating member during heat fixing. .

  For this purpose, the present embodiment is a mixture obtained by heat-kneading a toner raw material mixture having at least a binder resin, a colorant, and a charge control agent, cooling the obtained kneaded material, and then microparticulating it. It has been found that a toner for developing an electrostatic latent image, wherein the toner raw material mixture contains a compound represented by the following general formula (1) as a coloring aid, whereby the dispersion of the coloring agent is extremely good. It is a thing.

  In addition, for this purpose, the present embodiment is a method in which a toner raw material mixture having at least a binder resin, a colorant, a wax, and a charge control agent is heated and kneaded, and the obtained kneaded material is cooled, and then fine particles. The toner for developing an electrostatic latent image obtained by converting into a predetermined pressure density is mounted on a rheometer, and the molded product is heated to a melt outflow temperature under a load to flow out from a capillary tube. The method for evaluating the dispersion state of the wax contained in the toner by measuring the ratio of the area occupied by the wax component on the surface of the toner.

  In the present embodiment, in the toner obtained by the melt-kneading method, a toner having extremely high dispersibility of the colorant can be obtained by using a specific naphthol AS azo compound together with the colorant. Naphthol AS has been used as a colorant so far, but the inventor is not aware of any example of melt-kneading using a colorant and a specific naphthol AS azo compound as in this embodiment.

  The raw materials used for the electrostatic latent image developing toner of this embodiment will be described below. The compound represented by the following general formula (1) used in the present embodiment is a compound belonging to the naphthol AS system of an azo pigment, and has a structure in which a morpholine ring is substituted at the p-position of the azo group. This compound has sharper light absorption than the alkyl-substituted product of Patent Document 1 described above, and has a cyan color in which λMAX (the wavelength of the maximum peak value) is shifted to the longer wavelength side.

  For the powder of the colorant or monomer that has a metal salt in the molecule in the polyester resin powder that is the binder resin, set the temperature rise time and observe the molten state with a local microscope, or from the temperature rise with a rheometer By measuring the melt rheology, the dispersion state of the binder resin and the colorant or monomer can be observed. It can be seen that the dispersibility of pigments such as phthalocyanine and / or metal phthalocyanine and carbon black becomes extremely high when such naphthol AS-based azo pigments coexist. These comparison results and the like will be described by showing specific data in the section of Examples and Comparative Examples.

  The naphthol AS azo dye can be synthesized through a coupling reaction from a diazonium salt in an organic solvent. Examples of such an organic solvent include methylene chloride, chloroform, ethyl acetate, methyl acetate, carbon tetrachloride, cyclohexane, dioxane, hexane, toluene and the like. The branched chain aliphatic hydrocarbon type is an isoparaffin type hydrocarbon, and includes Isopar G, H, K, L, M, V and the like. Particularly desirable as the normal paraffin hydrocarbons are Norpearl 12, Norpar 13, Norpar 15 (made by Exxon), etc., but in some cases, alcohol solvents (methyl alcohol, ethyl alcohol, isopropyl alcohol, etc.) may be mixed. preferable. In particular, in the synthesis of the naphthol AS azo dye used in the present embodiment, it is preferable to use a nonpolar organic solvent as the organic solvent because it is advantageous for extraction of the obtained pigment.

  Examples of the diazonium salt include p-morpholino-2,5-butoxybenzenediazonium tetrafluoride, p-morpholino-2,5-ethoxybenzenediazonium tetrafluoride, p-morpholino-2,5-propoxybenzenediazonium tetrafluoride, p -Morpholino-2,5-isopropoxybenzenediazonium tetrafluoride, p-morpholino-2,5-t-butoxybenzenediazonium tetrafluoride and the like.

  Examples of the coupler component include naphthol AS and naphthol AS-SW. The above components are dissolved in the above-mentioned organic solvent in an equimolar amount to a coupler component in an amount of about 1.3 mol, and the temperature of the solvent is kept at about 20 ° C. while the alcohol amine is added dropwise. As the coupling reaction proceeds, the color of the solution changes to blue, and an azo dye is produced. After adding to about 10% alcohol aqueous solution and filtering, the azo dye of this embodiment can be obtained. When the elemental analysis of CHN is performed and the purity becomes 98% or more, the compound of the present embodiment is obtained. In some cases, it is possible to verify the -carboxamide group and the stretching vibration wavelength of the alkoxy group by infrared spectroscopic analysis.

  A synthesis example is shown below. While dissolving 0.1 mol of p-morpholino-2,5-butoxybenzene diazonium 1/2 zinc chloride in 1 L of 0.2% citric acid solution, 0.1 mol of commercially available hydrofluoric acid was added dropwise. Stir. The liquid temperature is kept at 20 ° C. The decomposition product and the like are removed, and a yellow precipitate is formed. This is filtered and dried. A three-necked flask that dissolves 0.11 mol of commercially available naphthol AS in 1.4-dioxane and dissolves the diazonium salt in place of the double salt described above (light length: 300 nm to 420 nm) uses a shaded color. Next, when 5 ml of alcoholamine is dropped and the solution is stirred, the coupling reaction proceeds and a blue pigment is precipitated. After filtration, it is filtered and dried while partially washing with an aqueous solution. Recrystallization with ethanol solvent, analysis of CHN element, and purity of 99% or more (ie, 1- (p-morpholino-2,5-butoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide The structural formula is a theoretical value, and the purity obtained by calculation from the value of the elemental analysis CHN, for example, from the numerical value of carbon number) is not a problem. In this way, a coloring aid 1- (p-morpholino-2,5-butoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide was obtained.

Further, the following compounds (coloring aids or dispersion aids) were synthesized using the diazonium compounds and coupler compounds described in the text.
1- (p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide 1- (p-morpholino-2,5-diethoxyazobenzene) -2-hydroxynaphthalene-3 -Phenylnaphthamide. 1- (p-morpholino-2,5-diisopropoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide. 1- (p-morpholino-2,5-dimethoxyazobenzene) -2- Hydroxynaphthalene-3-phenylnaphthamide. 1- (p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-carboamidonaphthalene

  Re-aggregation of the colorant is suppressed by allowing the naphthol AS-based azo dye of the present embodiment obtained as described above to coexist with 5 wt% to 20 wt% of the phthalocyanine and / or metal phthalocyanine dye or carbon black. Is done.

  Next, the binder resin will be described. As the binder resin in the present embodiment, a polyester resin, a styrene- (meth) acrylate copolymer resin, or the like is mainly used.

  When using a polyester resin, dicarboxylic acid and diol, and further, if necessary, trivalent or higher monomer (polyhydric carboxylic acid and polyhydric alcohol component) are added, followed by dehydration condensation (dehydration (or dehydration (or dehydration)). Dealcoholization) and polycondensation).

  Examples of the dicarboxylic acid include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, hexahydrophthalic anhydride, and tetrahydrophthalic anhydride. Examples thereof include dicarboxylic acids such as acid, cyclohexanedicarboxylic acid, succinic acid, malonic acid, glutaric acid, azelaic acid and sebacic acid, derivatives thereof or ester compounds thereof.

  Examples of the diol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, bisphenol A, polyoxyethylene- (2.0 ) -2,2-bis (4-hydroxyphenyl) propane and derivatives thereof, polyoxypropylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -Polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- ( 2.2) -2, -Bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.4) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (3.3) -2,2-bis (4 -Hydroxyphenyl) propane and derivatives thereof, polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-propylene oxide block copolymer diol, ethylene oxide-tetrahydrofuran copolymer diol, polycaprolactone Diol etc. are mentioned.

  Examples of the trivalent or higher polyvalent monomer include trifunctional or higher polyvalent carboxylic acids such as trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, and derivatives or esterified products thereof. (Above, acid component) or sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol Glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trimethylolbenzene (hereinafter, alcohol component) and the like.

  The polyester resin that can be used in the present embodiment can be obtained by performing a dehydration condensation reaction or a transesterification reaction using the above raw material components in the presence of a catalyst. The reaction temperature and reaction time at this time are not particularly limited, but are usually 150 to 300 ° C. and 2 to 24 hours.

  As a catalyst for performing the above reaction, for example, zinc oxide, stannous oxide, tetrabutyl titanate, monobutyltin oxide, dibutyltin oxide, dibutyltin dilaurate, paratoluenesulfonic acid, and the like can be used as appropriate.

  The polyester resin used in the present embodiment only needs to have an appropriate glass transition point as a toner, and the glass transition temperature (Tg) is preferably 40 ° C. or higher, and in particular, the Tg is 45 to 85 ° C. More preferred is 50 to 80 ° C. The acid value is preferably 30 or less, more preferably 15 or less, and particularly preferably 10 or less. If the acid value is too high, the charge amount is lowered and the desired charge amount cannot be obtained.

  Examples of the styrene monomer used in the monofunctional styrene- (meth) acrylate copolymer resin that can be suitably used in the present embodiment include styrene, α-methylstyrene, vinyltoluene, and p-sulfone. Examples include styrene and dimethylaminomethylstyrene.

  Monofunctional (meth) acrylic acid ester monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( Alkyl (meth) acrylates such as meth) acrylate, tertiary butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; cyclohexyl (meth) acrylate Alicyclic (meth) acrylates such as: aromatic (meth) acrylates such as benzyl (meth) acrylate; hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate; Phosphoric acid group-containing compounds such as (meth) acryloxyethyl phosphate (methacrylate; halogen atoms such as 2-chloroethyl (meth) acrylate, 2-hydroxy3-chloropropyl (meth) acrylate, and 2,3-dibromopropyl (meth) acrylate) Containing (meth) acrylate; Epoxy group-containing (meth) acrylate such as glycidyl (meth) acrylate; Ether group-containing (meth) acrylate such as 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate; Dimethylamino And a basic nitrogen atom or amide group-containing (meth) acrylate such as ethyl (meth) acrylate and diethylaminoethyl (meth) acrylate.

  Moreover, the monofunctional unsaturated compound which can be polymerized with these can also be used as needed. For example, a carboxyl group-containing vinyl monomer such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid; a sulfo group-containing vinyl monomer such as sulfoethylacrylamide; a nitrile group-containing vinyl monomer such as (meth) acrylonitrile; Ketone group-containing vinyl monomers such as vinyl methyl ketone and vinyl isopropenyl ketone; basic such as N-vinyl imidazole, 1-vinyl pyrrole, 2-vinyl quinoline, 4-vinyl pyridine, N-vinyl 2-pyrrolidone, N-vinyl piperidone Nitrogen atom or amide group-containing vinyl monomers can be used.

  When a styrene- (meth) acrylic acid ester copolymer is used as a binder resin, a normal polymerization method can be adopted as a production method thereof, such as solution polymerization, suspension polymerization, bulk polymerization, etc. The method of performing a polymerization reaction in presence is mentioned.

  Examples of the polymerization catalyst include 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), Examples thereof include benzoyl peroxide, dibutyl peroxide, butyl peroxybenzoate, and the amount used is preferably 0.1 to 10.0% by weight of the vinyl monomer component.

  The resin having a high melting temperature in the styrene (meth) acrylic resin is desirably used in combination with the above monofunctional monomer and the above crosslinking agent. The second resin having a melting temperature lower than that of the resin is preferably produced using the above monofunctional monomer, but is produced by appropriately adding a bifunctional or higher polyvalent monomer as necessary. You can also

  The copolymer resin of styrene- (meth) acrylic acid ester used in this embodiment may have an appropriate glass transition point as a toner, and the glass transition temperature (Tg) is preferably 40 ° C. or higher. Among them, those having a Tg of 45 to 85 ° C are more preferable, and 50 to 80 ° C is particularly desirable. The acid value is preferably 30 or less, more preferably 15 or less, and particularly preferably 10 or less. If the acid value is too high, the charge amount is lowered and the desired charge amount cannot be obtained.

  In addition, the binder resin used in the toner of the exemplary embodiment can be used by adding a wax as a release agent to the resin in part or in whole. The amount used is preferably 3% by weight or more, particularly preferably about 10% by weight of the total resin.

  There is no particular limitation on the means for internally adding the wax to the resin, but the temperature is higher than the temperature at which the wax melts, and the normal conditions under which the monomer for producing the resin reacts, for example, the heating conditions of 120 to 250 ° C Below, a wax-added resin can be obtained by adding a predetermined amount of wax and proceeding the polymerization reaction of the monomer. Further, the timing of adding the predetermined amount of wax may be in the initial stage of the polymerization reaction of the resin, or in the middle thereof, or may be immediately before the polymerization reaction is completed and the resin is removed from the reaction vessel. . In addition, when adding a wax after completion | finish of superposition | polymerization, it is necessary to take out resin, after fully stirring so that the added wax may disperse | distribute uniformly in resin.

  Next, examples of the colorant that can be used in the present embodiment include phthalocyanine and / or metal phthalocyanine, as well as known ones. Carbon blacks such as furnace black, channel black, acetylene black, thermal black, lamp black, etc. classified by the production method are used as black colorants, and phthalocyanine C.I. I. Pigment Blue 15-3, Indanthrone C.I. I. Pigment Blue 60 and the like are quinacridone C.I. I. Pigment Red 122, an azo-based C.I. I. Pigment Red 22, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 48: 3, C.I. I. Pigment Red 57: 1 and the like are azo-based C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 155, an isoindolinone-based C.I. I. Pigment Yellow 110, a benzimidazolone-based C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 154, C.I. I. Pigment Yellow 180, and the like. The content of the colorant is in the range of 1 to 20 parts by weight. These colorants can be used alone or in combination of two or more.

  In the toner of the present exemplary embodiment, a charge control agent is used in addition to the binder resin, the colorant, and the color auxiliary agent.

  The positive charge control agent is not particularly limited as long as it is a compound that imparts positive charge to the toner, but it is not limited to triphenylmethane dyes, nigrosine dyes, quaternary ammonium salts, quaternary ammonium groups and / or Or it is preferable that it is resin containing an amino group. These compounds can be used alone or in combination with two or more charge control agents. Examples of the positive charge control agent include the following products, but are not limited to those exemplified.

  Examples of the triphenylmethane dye include “OIL BLUE” (Orient Chemical Co., Ltd., “Copy Blue PR” (Clariant Co., Ltd.), etc. Examples of the nigrosine dye include “NIGROSINE BASE EX”, “OIL BLACK BS "," BONTORON N-01 "," BONTORON N-04 "," BONTORON N-07 "," BONTORON N-21 "(above Orient Chemical Co., Ltd.), etc. Examples of quaternary ammonium salt compounds "BONTRON P-51" (Orient Chemical Co., Ltd.), "TP-302", "TP-610", "TP-415" (above Hodogaya Chemical Co., Ltd.), "COPY CHARGE PSY" (Clariant) Quaternary ammonium group and the like. Examples of the resin containing amino groups and / or amino groups include “FCA-201-PS” (Fujikura Kasei Co., Ltd.).

  The negatively chargeable charge control agent used in the exemplary embodiment is not particularly limited as long as it is a compound that imparts negative chargeability to the toner. However, an azo metal complex (salt), a salicylic acid metal complex (salt) ), Benzylic acid metal complexes (salts), tetraphenyl metal complexes (salts), calixarene type phenol condensates, cyclic polysaccharides, and resin charge control agents.

  Examples of the salicylic acid-based metal complex include “BONTORON E-81”, “BONTORON E-84”, “BONTORON E-88” (above Orient Chemical Co., Ltd.) and the like. Examples of the benzyl acid metal complex include “LR-147” (Nippon Carlit Co., Ltd.). Examples of the tetraphenyl-based metal complex include “COPY CHARGENX” (Clariant). Examples of the calixarene-type compound include “BONTORON E-89” and “BONTORON F-21” (Orient Chemical Co., Ltd.). Examples of the cyclic polysaccharide include “COPY CHARGE NCA” (Clariant Co., Ltd.). Examples of the resin charge control agent include “FCA-1001-NS” (Fujikura Kasei Co., Ltd.), “COPY LEVEL NCS” (Clariant Co., Ltd.), and the like.

  The content of the charge control agent is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 8 parts by weight per 100 parts by weight of the binder resin. More preferably, it is 0.5 to 6 parts by weight.

  As the release agent, known polypropylene wax, polyethylene wax, modified polyolefin wax, higher fatty acid ester, Fischer-Tropsch wax, graft polymerization wax, higher aliphatic alcohol, amide wax, natural wax, etc. can be used. A release agent mainly composed of a higher fatty acid ester compound and / or an aliphatic alcohol compound is preferable because of good dispersibility in the polyester resin and good release properties and sliding properties. When the higher fatty acid ester wax and / or aliphatic alcohol is added to the toner, better hot offset resistance and fixing strength can be obtained as compared with the same amount of polyolefin wax such as polypropylene wax and polyethylene wax.

  Among the waxes composed mainly of higher fatty acid ester compounds, natural waxes include carnauba wax, montan wax, candelilla wax, rice wax, ibota wax, etc., and these waxes are refined and pulverized in the resin. The dispersion in is further improved. Examples of the synthetic ester wax include higher fatty acid esters such as pentaerythritol. Examples of the higher fatty acid ester include “WEP-5”, “WEP-6” (Nippon Yushi Co., Ltd.) and the like. Examples of the release agent mainly composed of an aliphatic alcohol compound include those mainly composed of a higher alcohol obtained by an oxidation reaction of paraffin, olefin and the like.

  For example, “Unilin 425”, “Unilin 550” (above Petrolite Co., Ltd.), “NPS-9210”, “Parakol 5070” (above Nippon Seiwa Co., Ltd.) )) And the like.

  Among mold release agents mainly composed of higher fatty acid ester compounds or aliphatic alcohol compounds, those having a melting point in the range of 65 ° C. to 130 ° C. are particularly preferable because they contribute greatly to offset resistance.

  The release agent may be used alone or in combination. Good fixing offset performance can be obtained by adding 0.3 to 15 parts by weight, preferably 1 to 5 parts by weight with respect to the binder resin. . When the amount is less than 0.3 part by weight, the offset resistance is impaired. When the amount is more than 15 parts by weight, the fluidity of the toner is deteriorated.

  As described above, the toner according to the exemplary embodiment includes the binder resin, the colorant, the release agent, and the charge control agent as essential components, but may include other additives. For example, a lubricant such as metal soap or zinc stearate can be used, and cerium oxide, silicon carbide, or the like can be used as an abrasive.

  Prior to melt-kneading the above toner materials, they are uniformly mixed in advance by a Henschel mixer or the like. The mixing conditions are not particularly limited, but may be mixed so as to obtain desired uniformity. For example, the mixing time can be changed, the temperature at the time of mixing can be changed, the number of rotations of stirring can be changed, and the shape and combination of the stirring blades can be changed. In addition, various raw materials may be added in order to perform multistage mixing. The coloring agent, coloring auxiliary agent and / or charge control agent used here may be a flashing treatment or a master batch which is melt-kneaded with the resin at a high concentration so as to be uniformly dispersed in the resin.

  The above mixture is mixed by a kneading means such as a two-roll, a three-roll, a pressure kneader, or a twin screw extruder. At this time, the colorant or the like may be uniformly dispersed in the resin, and the melt-kneading conditions are not particularly limited, but are usually 80 to 200 ° C. for 30 seconds to 2 hours. The kneaded product is usually cooled by a cooling belt, a roller, or the like. Since the dispersion state of the release agent changes depending on the cooling condition, the cooling condition can be set so as to obtain a desired dispersion state.

  If necessary, rough pulverization is performed for the purpose of reducing the load and improving the pulverization efficiency in the fine pulverization step. The apparatus and conditions used for coarse pulverization are not particularly limited, but it is general to coarsely pulverize to a particle size of 3 mm mesh pass or less with a rotoplex or a pulverizer.

  Next, a method of finely pulverizing with a mechanical pulverizer such as a turbo mill or a kryptron, an air pulverizer such as a spiral jet mill, a counter jet mill or a collision plate jet mill, and classifying with a wind classifier or the like can be mentioned. The pulverization and classification devices and conditions may be selected and set so as to obtain a desired particle size, particle size distribution, and particle shape. The volume average particle diameter of the particles constituting the toner is not particularly limited, but is usually adjusted to 5 to 15 μm.

  Usually, an external additive is mixed with the toner thus obtained using a mixer such as a Henschel mixer.

  In the present exemplary embodiment, various additives (referred to as external additives) can be used for the surface modification of the toner such as improvement of toner fluidity and charging characteristics. Examples of external additives that can be used in the present embodiment include inorganic fine powders such as silicon dioxide, titanium oxide, and alumina, and those surface-treated with a hydrophobizing agent such as silicone oil, resin fine powders, and the like. It is done.

  Among these, those suitably used as an external additive include those obtained by surface-treating inorganic fine powder of silicon dioxide with various polyorganosiloxanes, silane coupling agents, and the like (preferably silica subjected to hydrophobic treatment).

  Specifically, there are those marketed under the following trade names. AEROSIL; R972, R974, R202, R805, R812, RX200, RY200, R809, RX50, RA200HS, RA200H [Japan Aerosil Co., Ltd.] WACKER; HDK H2000, H2050, H3050, HVK2150 [Wacker Chemicals Co., Ltd.], Nippon; SS-10, SS-15, SS-20, SS-50, SS-60, SS-100, SS-50B, SS-50F, SS-10F, SS-40, SS-70, SS-72F, [Japan Silica Industry Co., Ltd.], CABOSIL; TS-500, TS-530, TS-610, TS-720, TG-308F, TG-709 F, TG-810G, TG-811F, TG820F [Cabot Specialty Chemicals・ Ink] etc. It is possible.

  The titanium oxide may be a hydrophilic grade or a hydrophobic grade that is surface-treated with octylsilane or the like. For example, there are those marketed under the following trade names. Titanium oxide T805 [Degussa Co., Ltd.], titanium oxide P25 [Nippon Aerosil Co., Ltd.] and the like. Examples of alumina include aluminum oxide C [Degussa Co., Ltd.].

  The particle size of these external additives is preferably 1/3 or less of the diameter of the toner, and particularly preferably 1/10 or less. These external additives may be used in combination of two or more of different average particle sizes. The proportion of silica used is usually 0.05 to 5% by weight, preferably 0.1 to 3% by weight, based on the toner.

  When the toner of this embodiment is used in the two-component development method, a carrier as shown below can be used. Iron powder, magnetite, ferrite, etc. used in the usual two-component development system can be used as the carrier core agent, but the true specific gravity is low, the resistance is high, the environment is stable, and it is easy to make a spherical shape. Is preferably used. The shape of the core agent can be used without any problem, such as a spherical shape or an indefinite shape. The average particle diameter is generally 10 to 500 μm, but 30 to 80 μm is preferable for printing a high resolution image.

  Examples of the coating resin for coating these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether polyvinyl ketone, vinyl chloride / vinyl acetate. Copolymers, styrene / acrylic copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluororesins, (meth) acrylic resins, polyesters, polyurethanes, polycarbonates, phenol resins, amino resins, melamine resins, benzoguanamine resins Urea resin, amide resin, epoxy resin, acrylic polyol resin and the like can be used. Among these, silicone resin, fluororesin, and (meth) acrylic resin are particularly excellent in charging stability and coating strength, and can be used more suitably. That is, the resin-coated carrier used in the present embodiment is a resin-coated magnetic carrier that uses ferrite or magnetite as a core agent and is coated with one or more kinds of resins selected from silicone resins, fluororesins, and (meth) acrylic resins. Preferably there is.

  In addition, as a non-magnetic one-component developing method, the non-magnetic toner conveyed by the toner carrier is frictionally charged by the layer thickness regulating member and the layer thickness is regulated to reduce the thickness on the toner carrier. In general, the electrostatic latent image is developed in such a manner that the electrostatic latent image bearing member is opposed to or not in contact with the electrostatic latent image carrier.

  Next, an image forming method in which the toner of this embodiment is preferably used will be described. The image forming method used in the present embodiment includes a charging process in which a voltage is applied to a charging member from the outside to charge the electrostatic latent image carrier, and a latent image forming an electrostatic latent image on the charged electrostatic latent image carrier. An image forming step, a developing step of developing the electrostatic latent image with the toner of the present embodiment to form a toner image on the electrostatic latent image carrier, and an intermediate transfer of the toner image on the electrostatic latent image carrier An image having a transfer step of transferring onto a recording material with or without a body, and a fixing step of forming a fixed image on the recording material by heating and pressurizing and fixing a toner image on the recording material by a heating and pressing means. It is a forming method.

  The heating and pressing means in the fixing step includes a rotary heating member having at least a heating body and a rotary pressure member that forms a nip by mutual pressure contact with the rotary heating member. The offset preventing liquid is applied to the contact surface with the toner image, and the toner image on the recording material is heated and pressed by the rotating heating member and the rotating pressure member while the recording material is nipped and conveyed at the nip portion.

  The rotary heating member is for applying heat for fixing the toner image on the recording material, and is used for a heat roller type heating and pressurizing unit to heat the toner image. The rotary pressing member forms a nip by mutual pressure contact with the rotary heating member, and heats the toner image on the recording material while sandwiching the recording material at the nip portion. It is a roller to pressurize.

  According to the toner for developing an electrostatic latent image of the present embodiment, in the toner by heat kneading, a colorant and a specific compound classified into the naphthol AS represented by the general formula (1) are used in combination as a color aid. Therefore, the dispersibility of the pigment is extremely good, the image density is high, a high-quality image without image fogging or white spots is obtained, the fixing part is not contaminated in heat fixing, and the color tone before and after fixing is stable. High-quality images can be obtained.

  Further, according to the electrostatic latent image developing toner of the present embodiment, since the polyester resin is used as the binder resin, the dispersion miscibility with the colorant and the color auxiliary agent is high, and the spectral absorption of the colorant after fixing is high. Not only did the characteristics not be affected, but no fouling occurred during fixing.

  Further, according to the toner for developing an electrostatic latent image of the present embodiment, since at least one of phthalocyanine or metal phthalocyanine or carbon black is used as a colorant, the dispersion miscibility is high, and the colorant after fixing is used. Spectral absorption characteristics are not affected.

  Further, according to the electrostatic latent image developing toner of the present embodiment, since the toner is mixed with an external additive, not only the fluidity is improved, but also the effect of suppressing the deterioration of the toner with time is obtained. .

  Further, according to the image forming method using the toner for developing an electrostatic latent image of the present embodiment, since the toner of the present embodiment is used, the heating member is not contaminated and heat fixing is performed. An image having an image quality can be formed.

  Next, a method for evaluating the dispersion state of the wax contained in the toner will be described. This evaluation is based on the electrostatic latent image obtained by heating and kneading a toner raw material mixture having at least a binder resin, a colorant, a wax, and a charge control agent, cooling the obtained kneaded material, and then microparticulating the mixture. Molding the developing toner to a predetermined pressure density, mounting the molded product on a rheometer, raising the temperature to the melting outflow temperature under load, and occupying the area of the wax component on the surface of the core melt discharged from the narrow tube This is done by measuring the ratio.

In the present invention, the powdered toner is weighed to a constant weight molded at a pressure density of 0.642 ± 0.100 g / ml, heated to a flow start temperature at a predetermined heating rate under a predetermined load, and melted out. A photograph obtained by cooling a material and selecting a die diameter having a diameter within a predetermined range and collecting a plurality of locations on the sample surface with a microtome, dyeing with ruthenium oxide and photographing with SEM or TEM The invention also includes a toner for electrophotography, wherein the area occupied by wax of the toner is in the range of 60 to 90%. Such a toner preferably has an area occupied by the wax of the toner in the range of 60 to 90% by the evaluation method described below. In such an evaluation method, it is preferable that the predetermined load is ^{5kgf / cm 2 ~30kgf / cm 2} , also preferably the predetermined heating rate is 3 ℃ / min~5 ℃ / min, the The die diameter in the predetermined range is preferably 0.5 mm to 0.7 mm.

  As is apparent from the above, this evaluation method measures the ratio of the wax component on the surface of the toner melt at the outflow start temperature. After cooling the melt, the surface portion is sampled and the metal oxide is used. After dyeing, the occupation ratio of the wax component in the toner surface is measured by a transmission electron microscope (TEM) and a scanning electron microscope (SEM). According to this method, compared to the conventional method of evaluating a kneaded product before fixing and a toner particle after pulverization classification, heat, pressure and density are added, and evaluation can be performed in a state close to the actual state.

In practice, the toner is molded to a pressure density of 0.5 g / ml to 0.7 g / ml, injected into a syringe under pressure, and then heated at a rate of temperature rise of 3 ° C./min under a load of 10 kgf / cm ^2. Then, a sample is prepared in the range of 0.5 mm to 0.7 mm in the diameter of the core shape from which the toner powder has melted and flowed out. A surface portion is collected from this sample with a microtome, dyed with a metal oxide, the state of the wax on the surface is photographed with TEM and SEM, and the occupied area of the wax at 50 μm ² is calculated.

Measurement conditions are that the load exerted on the molded article is ^{5kgf / cm 2 ~30kgf / cm 2} , said heating rate is 3 ℃ / min~5 ℃ / min, melt drained from said capillary The diameter after cooling is preferably 0.5 mm to 0.7 mm. Except for these conditions, the fixing conditions in the actual copying machine do not match.

  According to this evaluation method, it is preferable that the occupation ratio of the wax at the start temperature (92 ° C. to 117 ° C.) of the toner powder when receiving heat is 50% to 90%. Adherence to the surface occurs, which is not preferable. Further, the glossiness of the core melt at this time is 20% or less.

  Further, since the toner raw material mixture further contains the compound represented by the general formula (1), not only the dispersibility of the colorant is excellent, but also the area occupied by the wax on the surface at the time of heat melting. It is possible to obtain a high toner with excellent wax dispersion.

  Hereinafter, the present embodiment will be described more specifically with reference to examples and comparative examples, but the present embodiment is not limited to the following examples and comparative examples. In the following, “part” represents “part by weight”.

[Example 1]
<Toner prescription>
・ Polyester resin A (weight average molecular weight 2,000, Tg (glass transition temperature) 62 ° C., acid value 25 mgKOH / g) 45 parts ・ Polyester resin B (weight average molecular weight 15,500, Tg 50 ° C., acid value 15 mgKOH / g) 53 parts 1- (p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide (dispersing aid) 3 parts Carbon black (# 44: manufactured by Mitsubishi Kasei) 7 parts -Charge control agent (salicylic acid metal complex (Orient Chemical Co., Ltd.)) 2 parts

  The above material mixture was charged into a kneader, heated to 150 ° C., and sequentially charged in a predetermined cutout amount to obtain a colored resin. At this time, the first kneading zone temperature was set at 110 ° C., the second kneading zone at 90 ° C., the third and fourth kneading zone temperatures at 100 ° C., and the fifth kneading zone at 90 ° C. From the above conditions, a toner kneaded product was produced at a rate of 150 kg per hour.

  The kneaded product was pulverized and classified with a commercially available jet pulverizer, and measured with a Coulter Multisizer (manufactured by Coulter Inc.) to obtain a toner having a volume average particle diameter of 10.5 μm. To 100 parts of this toner, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 1.

[Example 2]
<Toner prescription>
Polyester resin A (weight average molecular weight 2,000, Tg 62 ° C., acid value 25 mgKOH / g) 35 parts Polyester resin B (weight average molecular weight 15,500, Tg 50 ° C., acid value 15 mg KOH / g) 43 parts 1- ( p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenyl naphthamide (dispersing aid) 3 parts, charge control agent (salicylic acid metal complex (manufactured by Orient Chemical)) 2 parts, copper phthalocyanine Pigment metal complex type dye (manufactured by Dainichi Seika Co., Ltd.) 7 parts ・ Oxidized polyethylene wax 5 parts

  The toner mixture material mixture was kneaded with a kneader in the same manner as in Example 1. The kneaded product was pulverized by a jet pulverizer and then classified to obtain a toner having a volume average particle diameter of 10.5 μm. To 100 parts of this toner, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 2.

[Example 3]
A toner of Example 3 was obtained in the same manner as in Example 2 except that the same amount of carnauba wax was used instead of the oxidized polyethylene wax in the formulation of Example 2. A scanning electron micrograph of the obtained toner is shown in FIG.

[Example 4]
<Toner prescription>
-Polyester resin A (weight average molecular weight 2,000, Tg 62 ° C, acid value 25 mgKOH / g) 45 parts-Polyester resin B (weight average molecular weight 15,500, Tg 50 ° C, acid value 15 mgKOH / g) 53 parts-1- ( p-morpholino-2,5-diisopropropoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide (dispersing aid) 0.2 part C.I. I. Pigment Red 3 and CI Pigment Red 6 53: 1 7 parts Charge control agent (salicylic acid metal complex (made by Orient Chemical)) 2 parts

  The material mixture of the toner formulation was kneaded with a kneader in the same manner as in Example 1. The kneaded product was pulverized by a jet pulverizer and then classified to obtain a toner having a volume average particle diameter of 10.5 μm. To 100 parts of this toner, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain a toner of Example 4.

[Example 5]
<Toner prescription>
Polyester resin (A) (weight average molecular weight 15,000, Tg 59 ° C., acid value 25 mgKOH / g) 40 parts Polyester resin (B) (weight average molecular weight 4,500, Tg 49 ° C., acid value 5 mg KOH / g) 38 parts -Carnauba wax 60%, rice wax 40% mixed product 5 parts-1- (p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide (dispersing aid) 0.3 Part ・ C. I. Pigment Yellow 180 10 parts Charge control agent (salicylic acid metal complex (manufactured by Orient Chemical)) 2 parts

  The toner mixture material mixture was kneaded with a kneader in the same manner as in Example 1. The kneaded product was pulverized by a jet pulverizer and then classified to obtain a toner having a volume average particle diameter of 10.5 μm. To 100 parts of this toner, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 5.

[Example 6]
<Toner prescription>
Polyester resin (A) (weight average molecular weight 21,000, Tg 63 ° C., acid value 5 mgKOH / g) 40 parts Polyester resin (B) (weight average molecular weight 4,500, Tg 49 ° C., acid value 5 mg KOH / g) 38 parts -Carnauba wax 60%, rice wax 40% mixed product 5 parts-1- (p-morpholino-2,5-dibutoxyazobenzene) -2-hydroxynaphthalene-3-phenylnaphthamide (dispersing aid) 0.3 Part ・ Carbon black (# 44: manufactured by Mitsubishi Kasei Co., Ltd.) 10 parts ・ Charge control agent (salicylic acid metal complex (manufactured by Orient Chemical)) 2 parts

  The toner mixture material mixture was kneaded with a kneader in the same manner as in Example 1. The kneaded product was pulverized by a jet pulverizer and then classified to obtain a toner having a volume average particle diameter of 10.5 μm. To 100 parts of this toner, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Example 6.

[Comparative Example 1]
<Toner prescription>
・ Polyester resin (A) (weight average molecular weight 8,500, Tg 55 ° C., acid value 20 mgKOH / g) 42 parts ・ Polyester resin (B) (weight average molecular weight 8,000, Tg 63 ° C., acid value 15 mg KOH / g) 41 parts・ Low molecular weight polyethylene wax (Biscol 550P: manufactured by Sanyo Chemical Co., Ltd.) 5 parts ・ Carbon black (# 44: manufactured by Mitsubishi Kasei Co., Ltd.) 10 parts ・ Charge control agent (salcylic acid metal complex (produced by Orient Chemical Co., Ltd.)) 2 parts

  A mixture of the toner formulation materials was kneaded in a kneader in the same manner as in Example 1. The kneaded product was pulverized with a jet pulverizer and then classified to obtain a toner having a volume average diameter of 10.5 μm. To 100 parts of this toner, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain the toner of Comparative Example 1.

[Comparative Example 2]
After kneading in the same manner as in Example 2 except that the dispersion aid used in Example 2 was not used, the mixture was pulverized with a jet mill pulverizer and classified with a classifier to obtain a volume average particle size of 10.5 μm. A toner was obtained. To 100 parts of this toner, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain a toner of Comparative Example 2.

[Comparative Example 3]
A blue toner having a volume average particle diameter of 10.5 μm was obtained by kneading, pulverizing, and classifying in the same manner as in Example 3 except that the dispersing aid used in Example 3 was not used. To 100 parts of this toner, 0.5 part of silicon dioxide (R-972: manufactured by Nippon Aerosil Co., Ltd.) was mixed with a Henschel mixer to obtain a toner of Comparative Example 3.

(Measurement of volume average particle diameter)
The volume average particle diameter of the toner is measured with a Coulter Counter TA-IIC or Coulter Multisizer (manufactured by Coulter Inc.). In the present embodiment, a Coulter multisizer is used, and an interface (manufactured by Nikkaki Co., Ltd.) that outputs a particle size distribution and a personal computer are used. The aperture used in the Coulter Multisizer was 100 μm, and the volume distribution of toner of 2 μm or more and less than 60 μm was measured to calculate the particle size distribution and average particle size.

Measurement condition (1) Aperture: 100 μm
(2) Sample preparation method: Electrolyte [ISOTON] Coulter Counter TA-IIC Coulter Multisizer (manufactured by Coulter), an appropriate amount of 50 to 100 ml of surfactant (neutral detergent) was added and stirred, and measurement sample 10 was added thereto. Add ~ 20 mg. This system was prepared by dispersing for 1 minute using an ultrasonic disperser.

  Each toner was mixed with a ferrite carrier having a volume average particle diameter of 50 μm coated with a silicone resin to prepare a developer having a toner concentration of 6%.

  Using the developer prepared here, evaluation of toner quality, image quality, and fixing quality by heating and pressing means was performed using a digital color printer IPSIO CX8200. Each evaluation item, evaluation contents and evaluation criteria are shown below. The fixing temperature was controlled by the surface temperature of the upper roll and was set to a set temperature of 175 ° C.

(Toner coloring power)
A solid image was prepared so that the toner amount on the transfer paper was 0.95 to 1.05 mg / cm ² and the gloss of the image surface after heat and pressure fixing was 20 to 30, and the reflection density of the obtained image was adjusted. Measurement was carried out by X-Rite 508. The obtained measured values were evaluated according to the following evaluation criteria.
A: 1.20 or more B: 1.05 or more and less than 1.20 C: 0.90 or more and less than 1.05 D: Less than 0.90

(Image density)
A square solid image having a side of 5 mm was printed out on a recording paper (transfer paper) (62 g / m @ 2), and the reflection density of the printed out image was measured by "Macbeth reflection densitometer RD918" (manufactured by Macbeth). The obtained measured values were evaluated according to the following evaluation criteria.
A: 1.40 or more B: 1.35 or more and less than 1.40 C: 1.00 or more and less than 1.35 D: less than 1.00

(Image fog)
When a solid white image is formed, the toner existing on the photosensitive drum is removed by taping with Mylar tape during the transition from the development step to the transfer step, and the reflection density of the toner stuck on the paper is measured by X-Rite. Measured with 508 manufactured. Evaluation was performed according to the following evaluation criteria using a numerical value obtained by subtracting the reflection density when the Mylar tape was directly applied to paper from the obtained reflection density. The smaller the numerical value, the more image fog is suppressed.
A: Less than 0.03 B: 0.03 or more and less than 0.07 C: 0.07 or more and less than 1.00 D: 1.00 or more

(Dot reproducibility)
Although the electric field is easy to close due to the latent image electric field, it is difficult to reproduce, but an image of an isolated dot pattern with a small diameter (40 μm) is printed on an area of 100 x 100 mm on A4 size general quality paper, and the dot reproduction status at that time is as follows Evaluation was performed according to the evaluation criteria.
A: 2 or less defects in 100 B: 3 to 5 defects in 100 C: 6 to 10 defects in 100 D: 11 or more defects in 100

(Image is missing)
An image in which a circular image (diameter 20 mm) was arranged at five locations was printed out, and the occurrence of a white spot of 100 μm or more generated on the image was measured and evaluated according to the following evaluation criteria.
A: Not generated B: Image blank is 5 or less C: 6 to 10 D: 11 or more

(Image vertical stripe)
A halftone image was printed out, and the number of vertical stripe-shaped image density unevenness generated on the image was measured and evaluated according to the following evaluation criteria.
A: Not generated B: One minor vertical line is generated C: 2 to 4 D: 5 or more

(Surface contamination of rotating heating member)
After completion of the 7,000 printout test for an image pattern with an image area ratio of 50, the appearance of residual toner adhering to the surface of the rotary heating member and the effect on the printout image were visually evaluated according to the following evaluation criteria.
A: No toner adherence B: Contamination of the rotating heating member with paper dust and toner adhering to the end of the rotating heating member were observed, but the influence on the fixed image was slight. C: Paper dust Although there is slight toner contamination on the back surface of the printout image due to contamination of the rotary heating member due to the toner and toner adhering to the end of the rotary heating member, there is almost no effect on the fixed image. D: Toner Effect on fixing image due to fixing and wrapping of printout image during printout test

(Fixed tone stability)
This evaluation measures the change in color after fixing from the color before fixing held by the toner itself. A Macbeth color eye 7000 was used, and the light source was ASTM-D65, the observation field of view was 2 °, and the SCE mode was used.

  The change in color was evaluated based on the fluctuation range before and after fixing b *. If this fluctuation range is large, a desired color cannot be obtained, and color matching is displaced. Practically, the fluctuation range needs to be less than 2.0, preferably less than 1.0. The above b * represents the b value of Lab.

  The above evaluation results are shown in Table 1.

  From Table 1, it can be seen that the toners of the examples have good toner quality, image quality, and fixing quality. On the other hand, the toner of the comparative example that does not contain the coloring aid according to the present embodiment has image fogging and dot reproducibility is not good. Further, it can be seen that the fixing portion is contaminated and the variation range of the color tone before and after fixing is large.

  Viscosity characteristics in the kneading were compared between the toner of this embodiment and the toner without a dispersion aid. The results are shown in Tables 2 and 3.

In the example shown in Table 2, the result obtained by comparing the melt viscosity characteristics of the toner obtained in Example 2 and the toner obtained in Comparative Example 2 is shown. As shown in this table, in the toner shown in Example 2, the outflow start temperature is less than 120 ° C., whereas in the toner of Comparative Example 2, it is about 125 ° C., and at 125 ° C., the toner of Example 2 is While the melt viscosity was about 10 × 10 ³ pa · s, the viscosity of the toner of Comparative Example 2 was about 27 × 10 ³ pa · s, which was more than double the viscosity. From Table 2, it can be seen that the toner of this embodiment has a low outflow start temperature and a low melt viscosity characteristic due to the addition of a naphthol compound having a morpholino group.

Similarly, the example shown in Table 3 shows the result of comparing the melt viscosity characteristics of the toner obtained in Example 3 and the toner obtained in Comparative Example 3. As shown in this table, in the toner shown in Example 3, the outflow start temperature is less than 120 ° C., whereas in the toner of Comparative Example 3, it is about 125 ° C. Even at 125 ° C., the toner of Example 3 is While the melt viscosity was about 10 × 10 ³ pa · s, the viscosity of the toner of Comparative Example 3 was about 20 to 22 × 10 ³ pa · s, which is more than double the viscosity. Table 3 also shows that the toner of this embodiment has a low outflow start temperature and a low melt viscosity characteristic due to the addition of a naphthol compound having a morpholino group.

  Further, scanning electron micrographs of the toners obtained in Example 3 and Comparative Examples 2 and 3 are shown in FIGS.

  From these electron micrographs, in FIG. 1 (Example 3), which is an example of the toner obtained by the manufacturing method of the present embodiment, white particles are wax particles and small black dots are pigments. It can be seen that these are uniformly dispersed and there is no undispersed portion. On the other hand, as can be seen from the electron micrographs shown in FIG. 2 (Comparative Example 2) and FIG. 3 (Comparative Example 3), both are undispersed regions that are only the binder resin portion as indicated by the arrow. The area was found to exist.

  As described above, the toner according to the present embodiment can lower both the outflow start temperature and the melt viscosity characteristic as compared with the conventional toner, and is a toner that is nearly uniformly dispersed. As described above, in this embodiment, the compound having hydroxy naphthalene having a similar skeleton to the pigment compound is a toner having a more uniform dispersibility by assisting the dispersion of the naphthol pigment, and the outflow start temperature and the melt viscosity characteristic. It is clear from the fact that rheological properties such as As in the present embodiment, in the toner containing the naphthol pigment with improved rheological properties, the melting start temperature can be reduced by about 5 degrees even when the base resin is the same as that of the conventional toner. It can be seen that rheological analysis is important from the viewpoint of providing low temperature toner. Such a toner having excellent rheological properties is a useful technology for the global environment.

  In addition, the naphthol compound for improving the dispersibility of the pigment used in the toner of the exemplary embodiment has excellent image quality and excellent fixing quality as shown in Table 1 above. Recognize. That is, it can be said that the toner of the present embodiment prevents thermal deterioration in the fixing process and maintains the image quality to the same level as the toner image before fixing. Even if some residual toner is generated after fixing, the residual toner is excellent in cleaning property because it is resistant to thermal degradation. Also from this point, it can be said that the toner of the present embodiment is excellent in maintainability.

  In the examples and comparative examples, the ratio of the occupied area of wax on the toner surface and the glossiness are shown below for Examples 2, 3, 5, 6 and Comparative Examples 1, 2, and 3 using wax in the toner formulation. It measured by the measuring method. Table 4 shows the measurement results.

(Percentage of wax occupied area on toner surface)
(1) The toner powder is molded to a pressure density of 0.642 ± 0.100 g / ml and weighed in the range of 1.0 g ± 0.025 g. Next, the sample is mounted on a measurement part of a commercially available thin tube rheometer (500C manufactured by Shimadzu Corporation), and the temperature is raised from 50 ° C. to the outflow start temperature at a heating rate of 3 ° C./min under a load of 10 kgf / cm ^2. .
(2) Since it melts out from around 105 ° C., the die diameter is selected so that the diameter of the melt that has flowed out is 0.5 mm to 0.7 mm after cooling, and air-cooled to prepare a sample.
(3) Three surfaces are collected from the prepared sample with a microtome, stained with ruthenium oxide, photographed with SEM and TEM, and the ratio of the occupied area of the wax is calculated from the ratio with the binder from the photograph.

(Glossiness of toner surface)
The sample prepared in (2) above is projected using a commercially available gloss tester (Nippon Denshoku Co., Ltd. VGS-1D), the light receiving slit is adjusted to 60 °, and the incident angle and light receiving angle are also adjusted to 60 °. Measure the value on the numerical display.

  From Table 4, the ratio of the occupied area of the wax on the surface of the toner melt at the outflow start temperature is in the range of 60% to 90%, and the glossiness is lower than 20%. On the other hand, in the toner of the comparative example, the ratio of the occupied area of the wax is 50% or less, and the glossiness is higher than 20%. On the other hand, according to observation with an electron microscope, the toner particles of the examples have a fine wax particle size, and the maximum particle size is 2 μm and the minimum particle size is 0.5 μm. From these results, it can be seen that the toner of the example has a high occupied area ratio of wax at the time of heat melting, and is excellent in wax dispersion.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

3 is a scanning electron micrograph showing a dispersion state of toner according to an embodiment of the present invention. 6 is a scanning electron micrograph showing a dispersion state of a toner of a comparative example. 6 is a scanning electron micrograph showing a dispersion state of a toner of a comparative example.

Claims (13)

An electrostatic latent image developing toner obtained by cooling a kneaded product obtained by heating and kneading a toner raw material mixture having at least a binder resin, a colorant, and a charge control agent,
The toner raw material mixture contains a compound represented by the following general formula (1).

  The electrostatic latent image developing toner according to claim 1, wherein the binder resin is a polyester resin.   The electrostatic latent image developing toner according to claim 1, wherein the colorant is at least one of phthalocyanine or metal phthalocyanine.   The electrostatic latent image developing toner according to claim 1, wherein the colorant is carbon black.   The electrostatic latent image developing toner according to claim 1, further comprising an external additive. A toner image obtained by developing the electrostatic latent image formed on the electrostatic latent image carrier with toner is transferred onto a recording material with or without an intermediate transfer member, and the recording is performed. An image forming method in which a toner image on a material is thermally fixed by a heating and pressing unit,
An image forming method, wherein the toner according to claim 5 is used as the toner.   A toner raw material mixture having at least a binder resin, a colorant, a wax, and a charge control agent is heated and kneaded, and the obtained kneaded product is cooled and then finely divided to obtain an electrostatic latent image developing toner. Molded to a specified pressure density, mounted on the rheometer, heated to the melt outflow temperature under load, and measured the ratio of the area occupied by the wax component on the surface of the core melt that had flowed out of the capillary tube A method for evaluating an electrostatic latent image developing toner. The load applied to the molded article, 5kgf / cm ² ~30kgf / electrostatic latent image evaluation method of developing toner according to claim 7, wherein the cm ^2.   The method for evaluating a toner for developing an electrostatic latent image according to claim 7, wherein the rate of temperature rise is 3 ° C./min to 5 ° C./min.   10. The electrostatic latent image developing toner according to claim 7, wherein a diameter of the core-like melt that has flowed out of the thin tube after cooling is 0.5 mm to 0.7 mm. Evaluation method.   Using the evaluation method according to any one of claims 7 to 10, the ratio of the area occupied by the wax component on the surface of the core melt that has flowed out in the range of 92 ° C to 117 ° C of the hot melt temperature is 50%. To 90% of the toner for developing an electrostatic latent image.   The glossiness of the core melt discharged by using the evaluation method according to any one of claims 7 to 10 in a range of a heat melting temperature of 92 ° C to 117 ° C is 20% or less. Toner for developing electrostatic latent image. 13. The electrostatic latent image developing toner according to claim 11, wherein the toner raw material mixture further contains a compound represented by the following general formula (1).

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