JP2019120866A - Method for manufacturing photoluminescent toner for electrophotography - Google Patents

Abstract

To provide a method with which a photoluminescent toner for electrophotography excellent in brightness can be obtained even when the toner is manufactured by using a photoluminescent pigment in a fusing and mixing method.SOLUTION: A method for manufacturing a photoluminescent toner for electrophotography by a method including: a step of fusing and mixing at least a binder resin and a photoluminescent pigment (fusing and mixing step); a step of pulverizing an obtained mixture (pulverization step); and a step of classifying an obtained pulverized product (classification step), wherein the softening point of the binder resin is 100°C or more and 135°C or less; the content of the photoluminescent pigment is 30 pts.mass or more based on 100 pts.mass of the binder resin; the fusing and mixing step is performed at a mixing temperature higher by 20°C or more than the softening point of the binder resin.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a photoluminescent toner for electrophotography used for developing a latent image formed in electrophotography, electrostatic recording, electrostatic printing and the like.

  Patent Document 1 discloses, in a binder resin, a coloring component composed of at least a coloring agent consisting of yellow, magenta and cyan and a pearl pigment having a thin layer of titanium dioxide coated on a flaky inorganic crystal substrate. SUMMARY OF THE INVENTION An electrophotographic gloss toner is disclosed.

JP 2008-139464 A

  When a bright toner is produced by a melt-kneading method such as a twin-screw kneader, there is a problem that the bright pigment is destroyed at the time of melt-kneading and the brightness is lost.

  The present invention relates to a method for producing a bright toner for electrophotography, which is excellent in photovolatility, even when the toner is produced using a photochromic pigment by a melt-kneading method.

  The present invention comprises the steps of melt-kneading at least the binder resin and the luster pigment (melt-kneading step), the step of grinding the obtained kneaded material (pulverizing step), and the step of classifying the obtained pulverized material (classifying step C.), and the softening point of the binder resin is 100.degree. C. or more and 135.degree. C. or less, and the content of the photo-volatile pigment is 100% or more of the binder resin 100. The present invention relates to a method for producing a photoluminescent toner for electrophotography, which is 30 parts by mass or more with respect to parts by mass, and the melting and kneading step is performed at a kneading temperature higher by 20 ° C. or more than the softening point of the binder resin.

  According to the method of the present invention, even if the toner is produced using the photo-volatilizing pigment by the melt-kneading method, a photoluminescent toner for electrophotography having excellent photo-volatility can be obtained.

  The present invention comprises the steps of melt-kneading at least the binder resin and the luster pigment (melt-kneading step), the step of grinding the obtained kneaded material (pulverizing step), and the step of classifying the obtained pulverized material (classifying step A method for producing a photoluminescent toner for electrophotography by a method comprising When producing a bright toner by the melt-kneading method, as a cause that the bright pigment is destroyed and the brightness is lost at the time of melt-kneading, as a result of focusing on the share given to the bright pigment at the time of melt-kneading It has been found that by controlling the relationship between the softening point of the resin and the kneading temperature, a pulverized toner having excellent luster can be obtained. In the present invention, the "glitter toner" refers to a toner having a metallic gloss on a fixed image or the like by the toner.

  The binder resin used as the raw material is not particularly limited, and examples thereof include polyester resins, vinyl resins such as styrene-acrylic resins, epoxy resins, polycarbonates, polyurethanes, and composite resins containing two or more of these resins. In the present invention, it is preferable to contain a polyester resin from the viewpoint of coexistence of low temperature fixability, durability and storage stability. Furthermore, in the present invention, by controlling the relationship between the softening point of the binder resin and the kneading temperature, the glitter pigment is difficult to be destroyed and the glitter is improved, while the glitter condition is hard to be destroyed. Due to the decrease in the dispersibility of the internal additive, particularly the wax, the durability of the toner tends to decrease. Therefore, when a wax is further used in the melt-kneading process, it is more preferable to use a composite resin having excellent wax dispersibility, in particular, a composite resin having a polyester resin and a styrene resin as a binder resin.

  The polyester resin is preferably a polycondensate of an alcohol component containing a dihydric or higher alcohol and a carboxylic acid component containing a dihydric or higher carboxylic acid compound.

  Examples of the divalent alcohol include aliphatic diols, preferably aliphatic diols having 2 to 20 carbon atoms, and more preferably aliphatic diols having 2 to 15 carbon atoms, and Formula (I):

(Wherein, OR and RO are oxyalkylene groups, R is ethylene and / or propylene groups, x and y indicate the average addition mole number of alkylene oxide, and each is a positive number, and x and y are The sum value is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 6 or less, further preferably 4 or less)
The alkylene oxide adduct of bisphenol A represented by these, bisphenol A, hydrogenated bisphenol A etc. are mentioned. Specific examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and the like.

  The alcohol component is preferably an alkylene oxide adduct of bisphenol A represented by the formula (I), from the viewpoint of coexistence of low temperature fixability, durability and storage stability. The content of the alkylene oxide adduct of bisphenol A represented by the formula (I) is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, still more preferably in the alcohol component. It is 95 mol% or more, more preferably 100 mol%.

  The divalent carboxylic acid compounds include, for example, dicarboxylic acids having 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms, and more preferably 3 to 10 carbon atoms, their anhydrides, or alkyl groups. Derivatives such as alkyl esters having 1 or more and 3 or less carbon atoms can be mentioned. Specific examples of dicarboxylic acids include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid, fumaric acid, maleic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, alkyl having 1 to 20 carbon atoms Aliphatic dicarboxylic acids such as succinic acid substituted with a group or an alkenyl group having 2 to 20 carbon atoms can be mentioned.

  The carboxylic acid component preferably contains terephthalic acid and / or fumaric acid from the viewpoint of achieving low temperature fixability, durability and storage stability. The content of terephthalic acid or fumaric acid in the carboxylic acid component is preferably 40 mol% or more, more preferably 50 mol% or more, and still more preferably 70 mol% or more. When terephthalic acid and fumaric acid are used in combination, the total content of both is preferably within the above range.

  The trivalent or higher carboxylic acid compound includes, for example, 4 to 20 carbon atoms, preferably 6 to 20 carbon atoms, more preferably 7 to 15 carbon atoms, and still more preferably 8 to 12 carbon atoms, and more preferably Preferably, trivalent or higher carboxylic acids having 9 to 10 carbon atoms, their anhydrides, or derivatives such as alkyl esters having 1 to 3 carbon atoms in the alkyl group can be mentioned. Specifically, 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), or their acid anhydrides and the like can be mentioned.

  The content of the trivalent or higher carboxylic acid compound is preferably 1 mol% or more, more preferably 3 mol% or more, and still more preferably 5 mol% or more in the carboxylic acid component from the viewpoint of high-temperature offset resistance. And, from the viewpoint of low-temperature fixability, it is preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 15 mol% or less.

  The alcohol component may contain a monovalent alcohol, and the carboxylic acid component may contain a monovalent carboxylic acid compound as appropriate from the viewpoint of adjusting the molecular weight and the softening point of the polyester resin.

  The equivalent ratio of the carboxylic acid component to the alcohol component (COOH group / OH group) is preferably 0.6 or more, more preferably 0.7 or more, and still more preferably 0.75 or more, from the viewpoint of adjusting the softening point of the polyester resin. Preferably, it is 1.1 or less, more preferably 1.05 or less.

  The polyester resin is preferably, for example, an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and, if necessary, in the presence of an esterification promoter, a polymerization inhibitor, etc. It can be produced by polycondensation at a temperature of 130 ° C. or more, more preferably 170 ° C. or more, and preferably 250 ° C. or less, more preferably 240 ° C. or less.

  Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bis triethanol aminate, and the like, with preference given to tin compounds. The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, based on 100 parts by mass of the total of the alcohol component and the carboxylic acid component. Preferably it is 1 mass part or less. Examples of the esterification promoter include gallic acid and the like. The amount of the esterification promoter is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, based on 100 parts by mass of the total of the alcohol component and the carboxylic acid component. More preferably, it is 0.1 parts by mass or less. Examples of the polymerization inhibitor include t-butyl catechol and the like. The amount of the polymerization inhibitor used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, based on 100 parts by mass of the total of the alcohol component and the carboxylic acid component. Preferably it is 0.1 mass part or less.

  In the present invention, the polyester resin may be a polyester resin which has been modified to such an extent that the properties thereof are not substantially impaired. As the modified polyester resin, for example, grafting or blocking with phenol, urethane, epoxy or the like according to the method described in JP-A-11-1336668, JP-A-10-239903, JP-A-8-20636, etc. Among the modified polyester resins, a urethane-modified polyester resin in which the polyester resin is urethane-stretched with a polyisocyanate compound is preferable.

  The styrene-based resin is an addition polymer of a raw material monomer containing at least styrene or a styrene derivative such as α-methylstyrene or vinyltoluene (hereinafter, styrene and a styrene derivative are collectively referred to as “styrene compound”).

  The content of the styrene compound, preferably styrene, is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more, from the viewpoint of improving the dispersibility of the wax in the raw material monomer of styrene resin. And from the viewpoint of improving the low-temperature fixability of the toner, it is preferably 95% by mass or less, more preferably 93% by mass or less, and still more preferably 90% by mass or less.

  In addition, the styrenic resin may contain, as a raw material monomer, a (meth) acrylic acid alkyl ester having 7 or more carbon atoms in the alkyl ester. Examples of the (meth) acrylic acid alkyl ester include 2-ethylhexyl (meth) acrylate, (meth) acrylic acid (iso) octyl, (meth) acrylic acid (iso) decyl, (meth) acrylic acid (iso) stearyl and the like It can be mentioned. It is preferable to use one or more of these. In the present specification, "(iso)" is meant to include both cases where this group is present and cases where this group is not present, and when these groups are not present, they are normal. Indicates that. Moreover, "(meth) acrylic acid" shows acrylic acid, methacrylic acid, or both.

  The carbon number of the alkyl ester in the (meth) acrylic acid alkyl ester as a raw material monomer of the styrenic resin is preferably 7 or more, more preferably 8 or more, from the viewpoint of improving the low-temperature fixability of the toner From the viewpoint of stability, it is preferably 12 or less, more preferably 10 or less. In addition, carbon number of this alkyl ester says carbon number derived from the alcohol component which comprises ester.

  The content of the (meth) acrylic acid alkyl ester is preferably 5% by mass or more, more preferably 7% by mass or more, and still more preferably 10% by mass from the viewpoint of improving the low-temperature fixability of the toner in the raw material monomer of styrene resin. From the viewpoint of improving the dispersibility of the wax, the content is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less.

  Raw material monomers of styrene resin include raw material monomers other than styrene compound and alkyl ester of (meth) acrylic acid, for example, ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; halovinyl such as vinyl chloride ; Vinyl esters such as vinyl acetate and vinyl propionate; ethylenic monocarboxylic acid esters such as dimethylaminoethyl (meth) acrylate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; N-vinylpyrrolidone And N-vinyl compounds such as H, may be contained.

  The addition polymerization reaction of the raw material monomer of the styrene resin can be carried out in the presence of an organic solvent or in the absence of a solvent, for example, in the presence of a polymerization initiator such as dicumyl peroxide, a polymerization inhibitor, a crosslinking agent, etc. The temperature condition is preferably 110 ° C. or more, more preferably 140 ° C. or more, and preferably 200 ° C. or less, more preferably 170 ° C. or less.

  When an organic solvent is used in the addition polymerization reaction, xylene, toluene, methyl ethyl ketone, acetone or the like can be used. The amount of the organic solvent used is preferably 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the raw material monomer of the styrene resin.

  In the present invention, the composite resin can react with any of the raw material monomer of the polyester resin and the raw material monomer of the styrenic resin from the viewpoint of coexistence of low temperature fixing property, durability, and storage property, through both reactive monomers. A resin in which a polyester resin and a styrene resin are chemically bonded is preferable.

  The dual reactive monomer has at least one functional group selected from the group consisting of a hydroxyl group, a carboxy group, an epoxy group, a primary amino group and a secondary amino group in the molecule, preferably a hydroxyl group and / or a carboxy group. Group, more preferably a compound having a carboxy group and an ethylenically unsaturated bond is preferable, and at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid and maleic anhydride is more preferable, From the viewpoint of the reactivity of the polycondensation reaction and the addition polymerization reaction, at least one selected from the group consisting of acrylic acid, methacrylic acid and fumaric acid is more preferable. However, when used together with a polymerization inhibitor, a polyvalent carboxylic acid compound having an ethylenically unsaturated bond such as fumaric acid functions as a raw material monomer of the polyester resin. In this case, fumaric acid or the like is not a bireactive monomer but a raw material monomer of a polyester resin.

  In addition, the bireactive monomer may be one or two or more (meth) acrylic esters selected from acrylic esters and methacrylic esters each having 6 or less carbon atoms in the alkyl group.

  The (meth) acrylic acid ester is preferably a (meth) acrylic acid alkyl ester from the viewpoint of reactivity to transesterification, and the carbon number of the alkyl group is preferably 2 or more, more preferably 3 or more, and preferably Is 6 or less, more preferably 4 or less. The alkyl group may have a substituent such as a hydroxyl group.

The amount of the dual reactive monomer used is preferably 1 mole or more from the viewpoint of enhancing the dispersibility of the styrene resin and the polyester resin and improving the durability of the toner with respect to 100 moles in total of the alcohol component of the polyester resin. It is more preferably 2 mol or more, and preferably 30 mol or less, more preferably 20 mol or less, still more preferably 10 mol or less from the viewpoint of low-temperature fixability.
Further, the amount of the bireactive monomer used is preferably from the viewpoint of enhancing the dispersibility of the styrenic resin and the polyester resin with respect to the total of 100 parts by mass of the raw material monomer of the styrenic resin to improve the durability of the toner. Is 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 30 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less from the viewpoint of low temperature fixability. Here, the polymerization initiator is included in the total of the raw material monomers of the styrenic resin.

  Specifically, it is preferable to produce the composite resin obtained by using the dual reactive monomer by the following method. The dual reactive monomer is preferably used for the addition polymerization reaction together with the raw material monomer of the styrenic resin from the viewpoint of improving the durability of the toner, and the viewpoint of improving the low temperature fixability and heat resistant storage stability of the toner.

The composite resin is produced, for example, by a method including a step (A) of polycondensation reaction with a raw material monomer of polyester resin, and a step (B) of an addition polymerization reaction with a raw material monomer of styrenic resin and both reactive monomers. Can.
Step (B) may be performed after step (A), step (A) may be performed after step (B), or step (A) and step (B) may be performed simultaneously.
In the step (A), a portion of the carboxylic acid component is subjected to a polycondensation reaction, and then the step (B) is carried out, and then the remainder of the carboxylic acid component is added to the polymerization system to carry out the polycondensation reaction of the step (A) and The method of further advancing the reaction with the bireactive monomer is more preferable, if necessary. Moreover, it is preferable to perform a process (A) and a process (B) in the same container.

  Moreover, you may use the polycondensation type-resin which superposed | polymerized previously instead of the process (A) which performs a polycondensation reaction. When the step (A) and the step (B) proceed in parallel, the mixture containing the raw material monomer of the styrenic resin may be dropped and reacted in the mixture containing the raw material monomer of the polyester resin. .

  Furthermore, in the toner of the present invention, the composite resin is more preferably a wax internally added composite resin in which a wax is previously contained in the composite resin from the viewpoint of durability. The internally wax-incorporated composite resin is obtained by carrying out a polycondensation reaction of a raw material monomer of a polyester resin and / or an addition polymerization reaction of a raw material monomer of a styrenic resin in the presence of a wax.

  As the wax, although the same one as the below-described releasing agent can be used, paraffin wax is preferable from the viewpoint of low temperature fixability.

  The internal addition amount of the wax is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, more preferably 100 parts by mass in total of the raw material monomer of the polyester resin and the raw material monomer of the styrene resin and the bireactive monomer. Is 1.5 parts by mass or more, and preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and still more preferably 7 parts by mass or less.

  When a wax is used in the production step of the composite resin, it is preferable to carry out the polycondensation reaction in the presence of the wax. For example, in step (A), the wax is added together with the raw material monomer of the polyester resin to carry out the polycondensation reaction. The method to do is mentioned.

  The mass ratio of the styrene resin to the polyester resin (styrene resin / polyester resin) in the composite resin is preferably 3/97 or more, more preferably 7/93 or more, still more preferably 10/90, from the viewpoint of wax dispersibility. From the viewpoint of achieving both the low temperature fixability, the durability, and the storage stability, it is preferably 45/55 or less, more preferably 40/60 or less, still more preferably 35/65 or less, further preferably 30 / It is 70 or less, more preferably 25/75 or less. In the above calculation, the mass of the polyester resin is the total amount of the raw material monomers of the polyester resin used, and the amount of the bireactive monomer is included in the raw material amount of the polyester resin. Further, the amount of the styrene resin is the total amount of the raw material monomer of the styrene resin and the polymerization initiator.

  The content of the polyester resin, preferably the composite resin, in the binder resin is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 100% by mass. .

  The softening point of the binder resin is 100 ° C. or more and 135 ° C. or less. The softening point of the binder resin is 100 ° C. or more, preferably 105 ° C. or more, more preferably 110 ° C. or more, from the viewpoint of durability and high-temperature offset resistance, and breaks the bright pigment during melt-kneading It is 135 degrees C or less, preferably 130 degrees C or less, more preferably 125 degrees C or less from a viewpoint which is not made to carry out.

  The glass transition temperature of the binder resin is preferably 40 ° C. or more, more preferably 50 ° C. or more from the viewpoint of storage stability, and preferably 80 ° C. or less, more preferably 70 ° C. or less from the viewpoint of low temperature fixability. It is less than ° C.

  The acid value of the binder resin is preferably 1 mg KOH / g or more, more preferably 5 mg KOH / g or more, still more preferably 10 mg KOH / g or more from the viewpoint of charge buildup, and preferably from the viewpoint of hygroscopicity. Is 25 mg KOH / g or less, more preferably 22 mg KOH / g or less.

  When the binder resin is composed of a plurality of resins, it is preferable that the weighted average value of the physical properties of each resin be in the above range.

  Examples of the photo-volatilizing pigment include pearl-like pigments, effect pigments and the like, and it is possible to use pigments which are not limited to toners and which are used as photo-volatilizing pigments.

  The pearlescent pigment may, for example, be a pigment obtained by coating a metal oxide on the surface of a ground product of mica, a bismuth type pigment in which bismuth oxychloride is dispersed in various vehicles with a solvent, and the like.

  As an effect pigment, the pigment etc. which coated the metal oxide in the surface are mentioned using the flakes manufactured artificially, such as an alumina flake, a silica flake, flake-like glass, as a base material.

  The amount of use of the photo-volatilized pigment is 30 parts by mass or more, preferably 40 parts by mass or more, more preferably 60 parts by mass or more, more preferably 100 parts by mass of the binder resin, from the viewpoint of expression of glitter Is 70 parts by mass or more, and preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and still more preferably 120 parts by mass or less from the viewpoint of low-temperature fixability.

  The average particle diameter of the glitter pigment dispersed in the toner obtained is preferably 8 μm or more, more preferably 10 μm or more from the viewpoint of glitter expression, and from the viewpoint of uniformly dispersing the glitter pigment in the toner Therefore, it is preferably 50 μm or less, more preferably 30 μm or less.

  Reinforcing fillers such as mold release agents (waxes), charge control agents, magnetic powders, flow improvers, conductivity adjusters, fibrous substances, etc. as raw materials to be used for melt-kneading, in addition to binder resins and photo-volatile pigments Additives such as antioxidants and cleanability improvers may be used.

  As a mold release agent (wax), hydrocarbon wax such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, Sazol wax, and oxides thereof Waxes, montan waxes and ester-based waxes such as deacidified waxes and fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts and the like, which may be used alone or in combination of two or more Can. Among these, carnauba wax is preferred from the viewpoint of durability.

  The melting point of the releasing agent is preferably 60 ° C. or more, more preferably 70 ° C. or more from the viewpoint of transferability of the toner, and preferably 160 ° C. or less, more preferably 140 ° C. from the viewpoint of low temperature fixability. The temperature is more preferably 130 ° C. or less, further preferably 120 ° C. or less.

  The amount of the releasing agent used is preferably 0.5 parts by mass or more, more preferably 100 parts by mass of the binder resin, from the viewpoints of low-temperature fixability and offset resistance of the toner and the dispersibility in the binder resin. The amount is preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, and preferably 15 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 7 parts by mass or less.

  The charge control agent is not particularly limited, and may contain any of a positively chargeable charge control agent and a negatively chargeable charge control agent.

  As positively chargeable charge control agents, nigrosine dyes such as "Nigrosine Base EX", "Oil Black BS", "Oil Black SO", "Bontron N-01", "Bontron N-04", "Bontron N-07" “Bontron N-09”, “Bontron N-11” (all, manufactured by Orient Chemical Industries Ltd.), etc .; Triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salt compounds, eg, "Bontron P-51" (Orient Chemical Industry Co., Ltd.), cetyltrimethyl ammonium bromide, "COPY CHARGE PX VP 435" (Clariant Co., Ltd.), etc .; Polyamine resin such as "AFP-B" (Orient Chemical Industry Co., Ltd.) Imidazole derivatives, such as “PLZ-2001”, “PLZ-8001” (above, made by Shikoku Kasei Kogyo Co., Ltd.), etc .; styrene-acrylic resins, such as “FCA-701PT” (Fujikura Kasei Co., Ltd.) ), And the like.

  In addition, as a negatively chargeable charge control agent, metal-containing azo dyes such as "VALIFAST BLACK 3804", "BONTRON S-31", "BONTRON S-32", "BONTRON S-34", "BONTRON S-36" (Above, Orient Chemical Industry Co., Ltd.), “Eisenspirone Black TRH”, “T-77” (Hodogaya Chemical Industry Co., Ltd.), etc .; metal compounds of benzyl acid compounds, for example, “LR- 147 "," LR-297 "(above, manufactured by Nippon Carlit Co., Ltd., etc.); metal compounds of salicylic acid compounds, for example," Bontron E-81 "," Bontron E-84 "," Bontron E-88 "," Bontron E-304 "(above, made by Orient Chemical Industry Co., Ltd.)," TN-105 "(made by Hodogaya Chemical Co., Ltd.), etc .; copper phthalocyanine dye; quaternary ammonium salt, such as" COPY CHARGE NX VP434 " (Manufactured by Clariant), nitroimidazole derivatives, etc .; organic gold And compounds of the genus.

  The amount of the charge control agent used is preferably 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, and preferably 10 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of charge stability of the toner. It is preferably at most 5 parts by mass, more preferably at most 3 parts by mass, further preferably at most 2 parts by mass.

  The raw material to be subjected to melt-kneading containing at least the binder resin and the photo-volatile pigment may be subjected to kneading at one time or separately for kneading, but after being mixed beforehand by a mixer such as a Henschel mixer or ball mill , It is preferable to supply to the kneader.

  The melt-kneading can be performed using a known kneader such as a closed kneader, a single-screw or twin-screw extruder, or an open roll kneader.

  In the present invention, the melt-kneading step is performed at a kneading temperature which is 20 ° C. or more higher than the softening point of the binder resin. By kneading the raw material under this temperature condition, it is possible to mix it with the binder resin without destroying the light volatile pigment. Here, the kneading temperature is the temperature of the kneaded material measured in the discharge part of the kneading machine. Therefore, the kneader to be used is preferably a single-screw extruder or a twin-screw extruder in which control of the temperature of the kneaded material is easy, and a twin-screw extruder is more preferable.

  The difference between the kneading temperature and the softening point of the binder resin is preferably 25 ° C. or more, more preferably 30 ° C. or more, preferably 70 ° C. or less, more preferably 60 ° C. or less.

  After the melt-kneading step, it is preferable that the kneaded material is appropriately cooled until the hardness which can be crushed is reached, and the grinding step and the classification step are carried out to obtain toner particles. Here, cooling means cooling the kneaded material to 0 ° C. or more and 50 ° C. or less, or cooling to a temperature equal to or less than the glass transition temperature of the binder resin in the kneaded material.

  The pulverizing step is a step of pulverizing the obtained kneaded product to obtain toner particles. The kneaded material may be ground at one time to a desired particle size or may be ground stepwise, but from the viewpoint of grinding efficiently and more uniformly, it may be performed in two stages of coarse grinding and fine grinding. preferable.

  The grinder used for the coarse grinding includes a hammer mill, a cutter mill, an atomizer, a rotoplex and the like.

  In the coarse grinding, it is preferable to grind until the maximum diameter is 3 mm or less. A ground product with a maximum diameter of 3 mm or less is obtained as a ground product having a mesh size of 3 mm after passing through a sieve having an opening of 3 mm after appropriately grinding the kneaded product until the particle size becomes about 0.05 mm or more and 3 mm or less. Can.

  Examples of a pulverizer used for pulverization include a fluidized bed jet mill, a jet mill such as a collision plate jet mill, and a mechanical mill.

  The degree of pulverization is preferably adjusted appropriately in accordance with the target particle size of the toner.

  Examples of classifiers used in the classification process include pneumatic classifiers, inertial classifiers, and sieve classifiers.

  In the present invention, it is preferable to further have an external addition step of mixing the toner particles obtained by the classification step with an external additive.

  In the toner of the present invention, an external additive is preferably used in order to improve the transferability. Examples of the external additive include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide and zinc oxide, and organic fine particles such as resin particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles, and the like. The above may be used in combination. Among these, silica is preferable, and from the viewpoint of the transferability of the toner, hydrophobic silica treated with hydrophobic treatment is more preferable.

  Examples of hydrophobizing agents for hydrophobizing the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, octyltriethoxysilane (OTES), methyltriethoxysilane, etc. Be

  The average particle size of the external additive is preferably 10 nm or more, more preferably 15 nm or more, and preferably 250 nm or less, more preferably 200 nm or less, from the viewpoint of chargeability, flowability and transferability of the toner. Preferably it is 90 nm or less.

  The amount of the external additive used is preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass with respect to 100 parts by mass of the toner before being treated with the external additive, from the viewpoints of chargeability, flowability and transferability of the toner. The amount is preferably at least 0.3 parts by mass, and more preferably at most 5 parts by mass, more preferably at most 3 parts by mass.

  The coverage of the toner particles with the external additive is preferably 50% or more, more preferably 80% or more, still more preferably 90% or more, and still more preferably 95% or more from the viewpoint of toner flowability and durability. And, from the viewpoint of preventing migration of the external additive to the photosensitive member, it is preferably 200% or less, more preferably 170% or less, and still more preferably 150% or less.

The volume median particle size (D ₅₀ ) of the toner of the present invention is preferably 5 μm or more, more preferably 10 μm or more, still more preferably 12 μm or more, and preferably 50 μm or less, more preferably 30 μm or less. In the present specification, the volume median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by volume fraction is 50% as calculated from the smaller particle size. When the toner is treated with an external additive, the volume median particle size of the toner particles before being treated with the external additive is taken as the volume median particle size of the toner.

  The toner obtained by the method of the present invention can be used as a one-component developing toner or as a two-component developer mixed with a carrier.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. Physical properties of the resin and the like were measured by the following methods.

[Softening point (Tm) of resin]
Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating a 1 g sample at a heating rate of 6 ° C./min, a load of 1.96 MPa is applied by a plunger, diameter 1 mm, length 1 mm Push out of the nozzle. The plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flowed out is taken as the softening point.

[Glass transition temperature of resin]
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), measure 0.01 to 0.02 g of a sample in an aluminum pan, raise the temperature to 200 ° C, and decrease the temperature decrease rate from that temperature Cool to 0 ° C. at 10 ° C./min. Next, the sample is heated at a temperature rising rate of 10 ° C./min to measure an endothermic peak. The temperature at the intersection of the extension of the baseline below the highest endothermic peak temperature and the tangent showing the maximum slope from the rising portion of the peak to the peak of the peak is taken as the glass transition temperature.

[Acid value of resin]
It measures based on the method of JISK0070. However, only the measurement solvent is changed to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)) from a mixed solvent of ethanol and ether defined in JIS K0070.

Melting point of mold release agent
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan), measure 0.01 to 0.02 g of a sample on an aluminum pan and raise the temperature to 200 ° C. at a heating rate of 10 ° C./min. Warm and cool from that temperature to -10 ° C at a temperature decrease rate of 5 ° C / min. Next, the sample is heated to 180 ° C. at a heating rate of 10 ° C./min and measured. The highest endothermic peak temperature observed from the melting endothermic curve obtained there is taken as the melting point of the release agent.

[Toner volume median particle size (D ₅₀ )]
Measuring machine: Coulter Multisizer II (manufactured by Beckman Coulter Co., Ltd.)
Aperture diameter: 100 μm
Analysis software: Coulter multisizer Accucomp version 1.19 (manufactured by Beckman Coulter Co., Ltd.)
Electrolyte: Isoton II (manufactured by Beckman Coulter Co., Ltd.)
Dispersion solution: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB (glyphin): 13.6) dissolved in electrolyte to adjust to 5% by mass Dispersion conditions: 10 mg of measurement sample in 5 mL of the dispersion Is added, and dispersed for 1 minute with an ultrasonic disperser (machine name: US-1, manufactured by SND Co., Ltd., output: 80 W), and then 25 mL of the electrolyte is added, and further, to the ultrasonic disperser Disperse for 1 minute to prepare a sample dispersion.
Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte so that the particle size of 30,000 particles can be measured in 20 seconds, 30,000 particles are measured, and the volume is determined from the particle size distribution. Determine the median particle size (D ₅₀ ).

[Average particle size of external additive]
The average particle size refers to a number average particle size, and the particle size (average value of the major axis and the minor axis) of 500 particles is measured from a scanning electron microscope (SEM) photograph, and the number average value is taken.

[Coverage by external additive]
Calculated from the following equation.
Coverage (%) = √3 / 2π × (D · ρt) / (d · ρs) × C × 100
(Wherein, D is the volume median particle diameter (D ₅₀ ) (μm) of the toner particles before the external addition step, d is the average particle diameter of the external additive (μm), ρ t is the specific gravity of the toner particles, ρs is the external The specific gravity of the additive, C represents the mass ratio of the toner particles to the external additive (external additive / toner particles)
The total coverage of the external additive is the sum of the coverages calculated for the respective external additives. In all of the examples and comparative examples, the specific gravity of toner particles is determined to be 1.2, and the specific gravity of silica to be 2.2.

Resin production example 1
Raw material monomers for polyester resins other than fumaric acid and trimellitic anhydride shown in Table 1, 40 g of tin (II) 2-ethylhexanoate, and 1 g of gallic acid were equipped with a nitrogen introducing pipe, a dewatering pipe, a stirrer and a thermocouple. The mixture was placed in a 10 liter four-necked flask and reacted at 230 ° C. for 8 hours. After the reaction, the reaction was performed at 8.3 kPa for 1 hour. Furthermore, the temperature was lowered to 210 ° C., 5 g of trimellitic acid anhydride, fumaric acid and tertiary butyl catechol were added, and the reaction was carried out until the desired softening point was reached, to obtain polyester resins (Resins A and B).

Resin production example 2
Raw material monomers for polyester resins other than fumaric acid and trimellitic anhydride shown in Table 1, 40 g of tin (II) 2-ethylhexanoate, and 1 g of gallic acid were equipped with a nitrogen introducing pipe, a dewatering pipe, a stirrer and a thermocouple. The mixture was placed in a 10-liter four-necked flask, reacted at 230 ° C. for 8 hours, and then reacted at 8.3 kPa for 1 hour.
The temperature was lowered to 170 ° C., and a mixture of a styrene-based resin raw material monomer, a bireactive monomer, and dicumyl peroxide was added dropwise over 1 hour by a dropping funnel. After aging the addition polymerization reaction while maintaining at 170 ° C. for 1 hour, raise the temperature to 210 ° C., remove the raw material monomer of styrenic resin for 1 hour at 8.3 kPa, and react the reaction between the bireactive monomer and the polyester portion went. Furthermore, trimellitic anhydride, fumaric acid, and 5 g of tertiary butyl catechol were added at 210 ° C., and the reaction was performed until the desired softening point was reached, to obtain a composite resin (Resin C).

Resin production example 3
Raw material monomers of polyester resin other than fumaric acid and trimellitic anhydride shown in Table 1, 40 g of tin (II) 2-ethylhexanoate, 1 g of gallic acid, and wax were introduced with a nitrogen introducing pipe, a dewatering pipe, a stirrer and a thermocouple The reaction mixture was placed in a 10 L four-necked flask equipped and reacted at 230 ° C. for 8 hours, and then reacted at 8.3 kPa for 1 hour.
Thereafter, in the same manner as in Resin Production Example 2, a composite resin (Resin D) was obtained.

Examples 1 to 10 and Comparative Examples 1 to 4
Binder resin shown in Table 2, luster pigment "Xirallic-NXT 260-30" (manufactured by Merck & Co., effect pigment), charge control agent "Bontron E-304" (Orient Chemical Co., Ltd., negatively chargeable) Charge control agent) and wax “HNP-9” (Nippon Seiwa Co., Ltd., paraffin wax, melting point: 79 ° C.) are premixed for 1 minute using a Henschel mixer, and then twin screw extruder “PCM-87” It melt-kneaded using (made by Ikegai Iron Works Co., Ltd.). Melt-kneading conditions were set such that the feed amount of the raw material was 3.0 kg / min, the screw rotation speed of the kneading part was set to the speed shown in Table 2, and the temperature of the kneaded material measured in the discharge part of the kneaded material was shown in Table 2. The barrel set temperature was adjusted to the temperature shown in Table 2 to obtain a kneaded product. The obtained kneaded product was cooled to 20 ° C. or less while rolling with a cooling roll, and the cooled melt-kneaded product was roughly pulverized to about 3 mm with Rotoplex (manufactured by Toa Kikai Co., Ltd.).
The crude material obtained is roughly crushed to a volume median particle size (D ₅₀ ) of 1.5 to 2.5 mm using a cutter mill (manufactured by Nara Machinery Co., Ltd.), and then a collision plate type jet mill “I-20 type” (Nippon New Co., Ltd.) It was finely pulverized by Matic Industrial Co., Ltd.).
Furthermore, the pulverized material obtained was classified by an air flow classifier “DSF type” (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain toner particles having a volume median particle diameter (D ₅₀ ) shown in Table 2.
100 parts by mass of the obtained toner particles, hydrophobic silica "R 972" (Nippon Aerosil Co., Ltd., hydrophobizing agent: DMDS, average particle diameter: 16 nm) as external additive, hydrophobic silica "RY-50" (Nippon Aerosil) Hydrophobic treatment agent: silicone oil (average particle diameter 40 nm) was added in the amount shown in Table 2 and mixed for 3 minutes with a Henschel mixer to obtain a toner.

  The obtained toner was melted on a slide glass and the average particle size of the pigment was measured by an optical microscope. The average particle size is an average value of the particle sizes of the top 30 particles among the 100 largest pigment particles observed with an optical microscope, and when the pigment has a minor axis and a major axis, the major axis is the major particle size. Adopted as particle size. The results are shown in Table 2.

Test Example 1 [Glittering]
(1) Preparation of reference sample [reference A]
A sample prepared by mixing 100 parts by mass of the resin A and 30 parts by mass of the brilliance pigment "Xirallic-NXT260-30" was placed on a slide glass, and heated and melted for 10 seconds with a hot plate set at 200 ° C. The brightness of the melted sample was taken as reference A.
[Standard C]
A sample of 100 parts by mass of resin A and 15 parts by mass of the brilliance pigment “Xirallic-NXT260-30” mixed with 15 parts by mass of the brilliance pigment “Xirallic-NXT260-30” sufficiently ground in a mortar is placed on a slide glass And heated for 10 seconds on a hot plate set at 200 ° C. The brightness of the melted sample was taken as reference C.
[Standard E]
A sample prepared by mixing 100 parts by mass of the resin A and 30 parts of the bright pigment “Xirallic-NXT260-30” sufficiently ground in a mortar was placed on a slide glass, and heated and melted for 10 seconds on a hot plate set at 200 ° C. The brightness of the melted sample was taken as reference E.

(2) Evaluation of High Volatility 0.01 g of each toner obtained in Examples and Comparative Examples was placed on a slide glass and heated at 200 ° C. for 10 seconds on a hot plate to melt the toner. The brilliance of the melted toner was visually observed, and was evaluated in five steps in comparison with the lightness of the reference sample (reference A, reference C, and reference E). The results are shown in Table 2.
〔Evaluation criteria〕
A: Glow very good B: Glow good C: Glow reduction D: Large Glow reduction E: Almost no brightness

Test Example 2 (Durability)
The toner is mounted on the ID cartridge of the non-magnetic one-component developing device "OKI COREFIDO B 431 dn" (manufactured by Oki Data Corporation), and the temperature is 25 ° C and the relative humidity is 50%. The idle operation was performed, and the surface of the developing roll was visually observed every one hour, and the time until occurrence of uneven streaks was measured, which was used as an indicator of durability. The experiment is conducted for up to 10 hours, and the larger the value, the better the durability. The results are shown in Table 2.
The uneven streaks refer to a state in which variation occurs in the amount of toner adhering on the developing roll, and the occurrence of the uneven streaks causes density in the image density at the time of printing.

From the above results, it can be seen that the toners obtained in Examples 1 to 10 are excellent in light volatility. Above all, it is understood from the comparison between Example 1 and Examples 9 and 10 that the durability is improved by using a composite resin, in particular, a wax internal addition composite resin as a binder resin.
On the other hand, as in Comparative Examples 1 and 2, if the difference between the softening point of the binder resin and the kneading temperature is too large or too small, the pigment is broken at the time of melt-kneading, so that it lacks photovolatility. . Further, even in Comparative Example 3 in which the amount of pigment is too small and Comparative Example 4 in which the softening point of the binder resin is too high, a toner excellent in photovolatility is not obtained.

  The bright toner for electrophotography obtained by the method of the present invention is suitably used for developing a latent image formed by an electrostatic charge image developing method, electrostatic recording method, electrostatic printing method or the like.

Claims (5)

  Method comprising at least a step of melt-kneading binder resin and luster pigment (melt-kneading step), a step of grinding the obtained kneaded material (pulverizing step), and a step of classifying the obtained ground material (classifying step) And the softening point of the binder resin is 100.degree. C. or more and 135.degree. C. or less, and the content of the photo-volatile pigment is 100 parts by mass to 100 parts by mass of the binder resin. And 30 parts by mass or more, and the melt-kneading step is performed at a kneading temperature higher by 20 ° C. or more than the softening point of the binder resin.   The manufacturing method according to claim 1, wherein the volume median particle diameter of the obtained toner is 5 μm or more.   The method according to claim 1 or 2, further comprising an external addition step of mixing the toner particles obtained by the classification step with an external additive, and the coverage of the toner particles by the external additive is 50% or more. .   The method according to any one of claims 1 to 3, wherein in the melt-kneading step, a wax is further used, and the binder resin contains a composite resin having a polyester resin and a styrene resin.   The manufacturing method according to any one of claims 1 to 3, wherein the binder resin contains a wax internally added composite resin having a polyester resin and a styrene resin.