Electrostatic image developing toner set

Abstract

To provide an electrostatic image developing toner set that offers superior low-temperature fixability during high-speed printing and suppresses fogging on paper, and a method of preparing the same.SOLUTION: An electrostatic image developing toner set is provided, comprising a binder resin, colorant, and release agent and including a yellow toner, cyan toner, magenta toner, and black toner. In comparison of content of the release agent per 100 pts.mass of the binder resin, content of the release agent in the black toner is the highest among the yellow toner, cyan toner, magenta toner, and black toner. A method for preparing the toner set is also provided.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an electrostatic charge image developing toner set used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, etc., and a method for preparing the toner set.

Background Art

[0002] When performing full-color printing using an electrophotographic image forming apparatus, generally, a toner set composed of four colors, namely, yellow, cyan, and magenta toners, which are so-called primary colors of colors, plus black toner, is used (see Patent Documents 1 to 3).

[0003] On the other hand, with the development of electrophotographic systems, there is a demand for the development of electrostatic charge image developing toners corresponding to higher image quality in further color printing, and there is also a demand for toners having low-temperature fixability that can support high-speed printing, for example, high-speed printing at about 0.5 to 1.0 seconds per sheet in the A4 vertical direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, although various studies have been made to improve the low-temperature fixability during high-speed printing, it is difficult to achieve compatibility with fogging on the paper surface.

[0006] The present invention relates to an electrostatic charge image developing toner set excellent in low-temperature fixing property during high-speed printing and capable of suppressing fogging on the paper surface, and a method for preparing the toner set.

Means for Solving the Problems

[0007] The present invention is 〔1〕 An electrostatic charge image developing toner set containing a yellow toner, a cyan toner, a magenta toner, and a black toner, which contains a binder resin, a colorant, and a release agent. In the comparison of the content of the release agent with respect to 100 parts by mass of the binder resin, among the above yellow toner, cyan toner, magenta toner, and black toner, the content of the release agent in the black toner is the largest. The electrostatic charge image developing toner set, and 〔2〕 A method for preparing an electrostatic charge image developing toner set by combining at least a yellow toner, a cyan toner, a magenta toner, and a black toner, which contains a binder resin, a colorant, and a release agent. In the comparison of the content of the release agent with respect to 100 parts by mass of the binder resin, among the above yellow toner, cyan toner, magenta toner, and black toner, the content of the release agent in the black toner is the largest. A method for preparing an electrostatic charge image developing toner set relates to.

Effects of the Invention

[0008] The electrostatic charge image developing toner set of the present invention exhibits excellent effects in improving the low-temperature fixing property during high-speed printing and suppressing fogging on the paper surface.

Modes for Carrying Out the Invention

[0009] The toner set for electrostatic charge image development of the present invention is a toner set for electrostatic charge image development containing a binder resin, a colorant, and a release agent, including yellow toner, cyan toner, magenta toner, and black toner. Among the yellow toner, cyan toner, magenta toner, and black toner, it is a major feature that the content of the release agent in the black toner is the highest. Although the reason why the toner excellent in low-temperature fixability during high-speed printing and fogging on the paper surface can be obtained by the method of the present invention is not clear, it is presumed as follows. Note that the following mechanism is an estimation and is not limited thereto.

[0010] Since the black toner has many conductive paths derived from the black colorant, its chargeability is low, and since the difference in charge amount from the yellow toner, cyan toner, and magenta toner is large, fogging on the paper surface is likely to occur. As a result of intensive studies by the present inventors, it has been found that when the content of the release agent in the black toner is increased, the dispersibility of the black colorant is improved by the release agent and the conductive paths are reduced, thereby improving the chargeability. Generally, it is the common technical knowledge of those skilled in the art that increasing the amount of a release agent with low chargeability decreases the chargeability. Therefore, the finding that the chargeability is improved by increasing the amount of the release agent can be said to be a novel and surprising effect even for those skilled in the art. Therefore, in the present invention, by increasing the content of the release agent in the black toner more than that in the yellow toner, cyan toner, and magenta toner, it is considered that the difference in charge amount for each color becomes smaller and fogging on the paper surface is suppressed. In addition, the black colorant used in the black toner has a stronger filler effect than other yellow colorants, cyan colorants, and magenta colorants, and is particularly inferior in low-temperature fixability during high-speed printing. However, in the present invention, by increasing the content of the release agent in the black toner more than that in the yellow toner, cyan toner, and magenta toner, it is considered that the black toner, which was most disadvantageous in fixability, is sufficiently plasticized, so that the low-temperature fixability during high-speed printing can be improved, and it has been found that both low-temperature fixability and suppression of fogging on the paper surface can be achieved.

[0011] In the comparison of the content of the release agent with respect to 100 parts by mass of the binder resin, as described above, among the yellow toner, cyan toner, magenta toner, and black toner, the content of the release agent in the black toner is the highest.

[0012] As the content of the release agent with respect to 100 parts by mass of the binder resin, the difference between the content of the release agent in the black toner and the maximum content of the release agent in the yellow toner, cyan toner, and magenta toner is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less. Note that the binder resin of the toner obtained by the suspension polymerization method includes all components incorporated into the polymer by polymerization such as polymerizable monomers, polymerization initiators, and chain transfer agents, and in the case of core-shell type toner, the shell resin is also included in the binder resin.

[0013] The toner set of the present invention is prepared by combining at least a yellow toner, a cyan toner, a magenta toner, and a black toner, and other color toners may be combined as necessary. All of the toners (hereinafter also referred to as toners of each color) included in the toner set of the present invention contain a binder resin, a colorant, and a release agent, and it is preferable that the yellow toner, cyan toner, magenta toner, and black toner are the same except that the colorant and the release agent are different.

[0014] The yellow toner, cyan toner, magenta toner, and black toner, preferably the toners of each color, may be either polymerized toners obtained by a suspension polymerization method, an emulsion aggregation method, etc., or pulverized toners obtained by a melt kneading method. However, in the present invention, from the viewpoint of suppressing fogging on the paper surface, toners obtained by the suspension polymerization method are preferable, and core-shell type toners in which core particles are coated with a shell layer are also preferable.

[0015] When obtaining toner by the suspension polymerization method, for example, a toner can be obtained by a method of suspension polymerizing a polymerizable monomer composition containing a polymerizable monomer, a colorant, and a release agent in an aqueous medium in the presence of a polymerization initiator. Specifically, a method of granulating the polymerizable monomer composition in an aqueous medium in the presence of a polymerization initiator and then performing suspension polymerization is preferred.

[0016] The polymerizable monomer preferably has a monovinyl monomer as the main component.

[0017] Examples of the monovinyl monomer include styrene; styrene derivatives such as vinyltoluene and α-methylstyrene; (meth)acrylic acid; (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate; derivatives of (meth)acrylic acid such as (meth)acrylonitrile and (meth)acrylamide; olefins such as ethylene, propylene, and butylene; vinyl halides and vinylidene halides such as vinyl chloride, vinylidene chloride, and vinyl fluoride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; vinyl ketones such as methyl vinyl ketone and methyl isopropenyl ketone; nitrogen-containing vinyl compounds such as 2-vinylpyridine, 4-vinylpyridine, and N-vinylpyrrolidone. These monovinyl monomers may be used alone or in combination of two or more. Among these, styrene, styrene derivatives, and (meth)acrylic acid esters are preferred among the monovinyl monomers.

[0018] The content of the monovinyl monomer in the polymerizable monomer is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more, and preferably 100% by mass or less, more preferably 99% by mass or less.

[0019] Also, the content of the monovinyl monomer in the polymerizable monomer composition is preferably 60% by mass or more, more preferably 65% by mass or more, still more preferably 70% by mass or more, and is preferably 100% by mass or less, more preferably 95% by mass or less, still more preferably 90% by mass or less.

[0020] From the viewpoint of hot offset resistance, the polymerizable monomer preferably contains a crosslinkable polymerizable monomer together with the monovinyl monomer. The crosslinkable polymerizable monomer refers to a monomer having two or more polymerizable functional groups. As the crosslinkable polymerizable monomer, a divinyl monomer is preferable. For example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and their derivatives; di(meth)acrylic acid esters such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate; and other divinyl compounds such as N,N-divinylaniline and divinyl ether. These crosslinkable polymerizable monomers can be used alone or in combination of two or more. The content of the crosslinkable polymerizable monomer is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, with respect to 100 parts by mass of the monovinyl monomer, and is preferably 5 parts by mass or less, more preferably 2 parts by mass or less.

[0021] Also, in the present invention, from the viewpoints of storage stability and low-temperature fixability, the polymerizable monomer preferably further contains a macromonomer. The macromonomer is a reactive oligomer or a reactive polymer having a polymerizable carbon-carbon unsaturated double bond at the end of the molecular chain.

[0022] The number average molecular weight of the macromonomer is preferably 1,000 or more, more preferably 3,000 or more, and is preferably 30,000 or less, more preferably 20,000 or less, still more preferably 10,000 or less.

[0023] The content of the macromonomer is preferably 0.01 part by mass or more, more preferably 0.03 part by mass or more, still more preferably 0.05 part by mass or more, based on 100 parts by mass of the monovinyl monomer, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 1 part by mass or less.

[0024] As the colorant, a pigment and a dye are used, and a pigment is preferred from the viewpoint of further improving the coloring effect. As the pigment, either an inorganic pigment or an organic pigment can be used, but an organic pigment is preferred.

[0025] As the colorant for the yellow toner, organic pigments such as monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, isoindoline compounds, benzimidazolone compounds, anthraquinone compounds, azo metal complexes, and methine compounds, and dyes such as azo-based and anthraquinone-based dyes can be mentioned. Specific examples of the organic pigment include C.I. Pigment Yellow 17, 74, 93, 95, 109, 111, 128, 139, 151, 154, 155, 174, 180, 185, 214, etc. Among these, condensed azo compounds are preferred, and C.I. Pigment Yellow 93 and C.I. Pigment Yellow 214 are more preferred.

[0026] As the colorant for the cyan toner, organic pigments such as copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds, and dyes such as benzoquinone-based, anthraquinone-based, indigo-based, and phthalocyanine-based dyes can be mentioned. Specific examples of the organic pigment include C.I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, 66, etc. Among these, copper phthalocyanine compounds are preferred, and C.I. Pigment Blue 15 is more preferred.

[0027] Examples of colorants for magenta toner include organic pigments such as monoazo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds, and dyes such as benzoquinone-based, anthraquinone-based, and indigo-based dyes. Specific examples of organic pigments include C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48:1, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, and C.I. Pigment Violet Red 19. Among these, quinacridone compounds are preferred, and C.I. Pigment Red 122 and C.I. Pigment Violet Red 19 are more preferred.

[0028] Examples of colorants for black toner include inorganic pigments such as carbon black and inorganic composite oxides, and dyes such as azine-based and aniline black-based dyes.

[0029] From the viewpoint of improving the color developability of the toner, the content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and preferably 15 parts by mass or less, more preferably 13 parts by mass or less, still more preferably 10 parts by mass or less, based on 100 parts by mass of the binder resin.

[0030] Examples of the release agent include hydrocarbon waxes, ester waxes, silicone waxes, fatty acid amide waxes, and the like. Examples of hydrocarbon waxes include mineral or petroleum-based hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax; and synthetic hydrocarbon waxes such as polyolefin waxes such as polyethylene wax, polypropylene wax, and polybutene wax. Examples of ester waxes include mineral or petroleum-based ester waxes such as montan wax; plant-based ester waxes such as carnauba wax, rice wax, candelilla wax; animal-based ester waxes such as beeswax, and synthetic ester waxes obtained by condensing carboxylic acids such as fatty acids and alcohols such as aliphatic alcohols. Examples of fatty acid amide waxes include oleic acid amide, stearic acid amide, etc. Among these, from the viewpoint of the releasability of the toner, hydrocarbon wax or ester wax is preferable, and ester wax is more preferable.

[0031] From the viewpoint of the releasability of the toner, the melting point of the release agent is preferably 60°C or higher, more preferably 65°C or higher, still more preferably 70°C or higher, and from the viewpoint of improving the low-temperature fixability of the toner, it is preferably 100°C or lower, more preferably 90°C or lower, still more preferably 85°C or lower, still more preferably 80°C or lower.

[0032] The content of the release agent in the yellow toner, cyan toner, and magenta toner is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 7 parts by mass or more, and preferably 15 parts by mass or less, more preferably 13 parts by mass or less, still more preferably 11 parts by mass or less, based on 100 parts by mass of the binder resin.

[0033] On the other hand, the content of the release agent in the black toner is preferably 5 parts by mass or more, more preferably 7 parts by mass or more, still more preferably 9 parts by mass or more, and preferably 25 parts by mass or less, more preferably 22 parts by mass or less, still more preferably 18 parts by mass or less, still more preferably 16 parts by mass or less, still more preferably 14 parts by mass or less, based on 100 parts by mass of the binder resin.

[0034] The coincidence monomer composition may further contain a charge control agent, a chain transfer agent, inorganic fine particles such as silica, aluminum oxide, titanium oxide, zinc oxide, tin oxide, etc., magnetic powder, a fluidity improver, a conductivity regulator, a reinforcing filler such as a fibrous substance, an antioxidant, an anti-aging agent, a cleaning property improver, etc.

[0035] The charge control agent may contain either a positive charge control agent or a negative charge control agent.

[0036] Examples of the positive charge control agent include 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" (manufactured by Orient Chemical Industries Co., Ltd., etc.); triphenylmethane dyes containing a tertiary amine as a side chain, quaternary ammonium salt compounds such as "Bontron P-51" (manufactured by Orient Chemical Industries Co., Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PX VP435" (manufactured by Clariant, etc.); polyamine resins such as "AFP-B" (manufactured by Orient Chemical Industries Co., Ltd., etc.); imidazole derivatives such as "PLZ-2001", "PLZ-8001" (manufactured by Shikoku Kasei Kogyo Co., Ltd., etc.); styrene-acrylic resins such as "FCA-161P", "FCA-201-PS", "FCA-701PT" (manufactured by Fujikura Kasei Co., Ltd., etc.).

[0037] Examples of the negative charge control agent include metal-containing azo dyes such as "Vari Fast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", "Bontron S-36" (manufactured by Orient Chemical Industries, Ltd.), "Eisen Spilon Black TRH", "T-77" (manufactured by Hodogaya Chemical Co., Ltd.), etc.; metal compounds of benzoic acid compounds such as "LR-147", "LR-297" (manufactured by Nippon Carlit Co., Ltd.), etc.; metal compounds of salicylic acid compounds such as "Bontron E-81", "Bontron E-84", "Bontron E-88", "Bontron E-304" (manufactured by Orient Chemical Industries, Ltd.), "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.), etc.; copper phthalocyanine dyes; quaternary ammonium salts such as "COPY CHARGE NX VP434" (manufactured by Clariant), nitroimidazole derivatives, etc.; and organometallic compounds, etc. These may be used alone or in combination of two or more.

[0038] In the present invention, from the viewpoint of paper surface fogging, yellow toner, cyan toner, magenta toner, and black toner, preferably each color toner, is preferably a positive chargeable toner. Therefore, as the charge control agent, it is preferably contained a positive charge control agent, more preferably contained a polymer type charge control resin, and even more preferably contained a quaternary ammonium salt-containing resin.

[0039] As the quaternary ammonium salt-containing resin, a quaternary ammonium salt-containing styrene resin is preferred.

[0040] The quaternary ammonium salt-containing styrene resin is not particularly limited, but is preferably a copolymer of a styrene monomer (M1) and / or a (meth)acrylic acid alkyl ester monomer (M2) and a quaternary ammonium salt (M3) of a dialkylaminoalkyl (meth)acrylate monomer.

[0041] The styrene monomer (M1) is styrene and does not include derivatives of styrene such as α-methylstyrene, p-methylstyrene, and p-chlorostyrene.

[0042] Examples of the alkyl (meth)acrylate monomer (M2) include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, propyl (meth)acrylate, amyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, etc. The number of carbon atoms in the alkyl group is preferably 4 or more and 12 or less. Among these, butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate is preferred, and butyl (meth)acrylate is more preferred.

[0043] The quaternary ammonium salt (M3) of the dialkylaminoalkyl (meth)acrylate monomer is represented by the formula (I):

[0044] [Chemical formula]

[0045] (In the formula, R 1 is a hydrogen atom or a methyl group, R 2 is an alkylene group having 1 or more and 5 or less carbon atoms, and R 3 to R 5 each independently represents an alkyl group having 1 or more and 5 or less carbon atoms) The compound represented by the formula is preferred.

[0046] In the formula (I), R 1 is preferably a methyl group. Examples of R 2 include a methylene group, an ethylene group, a propylene group, a butylene group, etc. Among these, an ethylene group is preferred. R 3 to R 5Examples include a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. Among these, a methyl group or an ethyl group is preferred, and an ethyl group is more preferred.

[0047] Examples of the dialkylaminoalkyl (meth)acrylate include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dipropylaminoethyl (meth)acrylate, dibutylaminoethyl (meth)acrylate, etc. Among these, diethylaminoethyl (meth)acrylate is preferred because it is inexpensive.

[0048] As a method for producing a quaternary ammonium salt-containing styrene resin, for example, a dialkylaminoalkyl (meth)acrylate is quaternized using an alkyl p-toluenesulfonate according to a conventional method to obtain a quaternary ammonium salt (M3) of the dialkylaminoalkyl (meth)acrylate monomer. Then, this is mixed with a styrene monomer (M1) and / or an alkyl (meth)acrylate monomer (M2) and copolymerized in the presence of a polymerization initiator.

[0049] Examples of the alkyl p-toluenesulfonate include methyl p-toluenesulfonate, ethyl p-toluenesulfonate, propyl p-toluenesulfonate, etc. Among these, methyl p-toluenesulfonate is preferred because quaternization is easy.

[0050] The amount of the alkyl p-toluenesulfonate used is preferably 0.8 mol or more, more preferably 1 mol or more, and preferably 1.5 mol or less, more preferably 1.2 mol or less, per 1 mol of the dialkylaminoalkyl (meth)acrylate to be reacted therewith.

[0051] As the copolymerization method, any method such as solution polymerization, suspension polymerization, bulk polymerization, emulsion polymerization, etc. may be used, but solution polymerization is preferred because the mass average molecular weight of the resulting copolymer can be relatively easily controlled and the reaction operation is easy.

[0052] Examples of the solvent used in solution polymerization include ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, alcohol solvents such as normal butanol and isobutanol, ester solvents such as ethyl acetate and isobutyl acetate, and aromatic hydrocarbon solvents such as toluene and xylene. Among these, from the viewpoint of the solubility of the copolymer, ketone solvents or alcohol solvents are preferred.

[0053] As the polymerization initiator, peroxide initiators such as tert-butyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, 1,1-di(tert-butylperoxy)cyclohexane, and dibenzoyl peroxide, and azo initiators such as 2,2'-azobis(2-methylbutyronitrile) are used.

[0054] The amount of the polymerization initiator used is preferably 0.5 parts by mass or more and 10 parts by mass or less based on 100 parts by mass in total of the monomers.

[0055] In the quaternary ammonium salt-containing styrene resin, the content of the styrene monomer (M1) unit in the total amount of the styrene monomer (M1) unit, the (meth)acrylic acid alkyl ester monomer (M2) unit, and the quaternary ammonium salt (M3) unit of dialkylaminoalkyl (meth)acrylate is preferably 40% by mass or more, more preferably 50% by mass or more, and preferably 80% by mass or less, more preferably 75% by mass or less.

[0056] In the quaternary ammonium salt-containing styrene resin, the content of the (meth)acrylic acid alkyl ester monomer (M2) unit in the total amount of the styrene monomer (M1) unit, the (meth)acrylic acid alkyl ester monomer (M2) unit, and the quaternary ammonium salt (M3) unit of dialkylaminoalkyl (meth)acrylate is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less.

[0057] In the quaternary ammonium salt-containing styrene resin, the content of the quaternary ammonium salt (M3) unit of dialkylaminoalkyl (meth)acrylate in the total amount of the styrene monomer (M1) unit, the (meth)acrylic acid alkyl ester monomer (M2) unit, and the quaternary ammonium salt (M3) unit of dialkylaminoalkyl (meth)acrylate is preferably 0.5% by mass or more, more preferably 1% by mass or more, and preferably 35% by mass or less, more preferably 30% by mass or less.

[0058] Examples of commercially available products of the quaternary ammonium salt-containing styrene resin include "FCA-161P", "FCA-201-PS", and "FCA-701-PT" (all manufactured by Fujikura Kasei Co., Ltd.).

[0059] From the viewpoint of storage stability, the softening point of the quaternary ammonium salt-containing resin is preferably 90°C or higher, more preferably 95°C or higher, still more preferably 100°C or higher, and from the viewpoint of low-temperature fixability, it is preferably 140°C or lower, more preferably 135°C or lower, still more preferably 130°C or lower.

[0060] From the viewpoint of storage stability, the glass transition temperature of the quaternary ammonium salt-containing resin is preferably 35°C or higher, more preferably 40°C or higher, still more preferably 45°C or higher, and from the viewpoint of low-temperature fixability, it is preferably 90°C or lower, more preferably 85°C or lower, still more preferably 80°C or lower.

[0061] The content of the charge control agent is preferably 0.01 part by mass or more, more preferably 0.2 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, and still more preferably 2 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0062] Examples of the chain transfer agent include mercaptans such as tert-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, and 2,2,4,6,6-pentamethylheptane-4-thiol. The chain transfer agent can be added before the start of polymerization or during the polymerization.

[0063] The content of the chain transfer agent is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

[0064] The polymerizable monomer, colorant, release agent, and other additives as required are mixed, and each component is dissolved to obtain a polymerizable monomer composition.

[0065] As the aqueous medium, those mainly composed of water are preferred. The content of water in the aqueous medium 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 98% by mass or more, and 100% by mass or less. As the water, deionized water or distilled water is preferred.

[0066] Examples of components other than water that can be contained in the aqueous medium include organic solvents soluble in water such as alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran.

[0067] The aqueous medium preferably contains a dispersion stabilizer.

[0068] Examples of the dispersion stabilizer include sulfates such as barium sulfate and calcium sulfate; carbonates such as barium carbonate, calcium carbonate, and magnesium carbonate; phosphates such as calcium phosphate; metal oxides such as aluminum oxide and titanium oxide; metal compounds such as metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and ferric hydroxide, water-soluble polymers such as polyvinyl alcohol, methyl cellulose, and gelatin; anionic surfactants; nonionic surfactants; and organic polymer compounds such as amphoteric surfactants. The dispersion stabilizer can be used alone or in combination of two or more kinds.

[0069] Among the dispersion stabilizers, a dispersion stabilizer containing a colloid of a metal compound, particularly a hardly water-soluble metal hydroxide, can narrow the particle size distribution of the colored polymer particles, and since the remaining amount of the dispersion stabilizer after washing is small, the image can be reproduced clearly and the environmental stability is not deteriorated, which is preferable.

[0070] The content of the dispersion stabilizer is preferably 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

[0071] Examples of the polymerization initiator used for the polymerization of the polymerizable monomer composition include persulfates such as potassium persulfate and ammonium persulfate; azo compounds such as 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobisisobutyronitrile; peroxides such as di-tert-butyl peroxide, benzoyl peroxide, tert-butyl peroxy-2-ethylbutanoate, tert-butyl peroxy-2-ethylhexanoate, tert-hexyl peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, di-tert-butyl peroxyisophthalate, and tert-butyl peroxyisobutyrate. Further, a redox initiator combining the above polymerization initiator and a reducing agent may be used.

[0072] The amount of the polymerization initiator is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, still more preferably 0.5 part by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less, based on 100 parts by mass of the polymerizable monomer.

[0073] The polymerizable monomer composition can be put into an aqueous medium and granulated in the presence of a polymerization initiator. The polymerization initiator may be added to the aqueous medium before granulation after dispersing the polymerizable monomer composition in the aqueous medium, or may be added in advance to the polymerizable monomer composition before dispersing it in the aqueous medium.

[0074] The granulation method is not particularly limited. For example, it is preferably carried out using a device capable of strong stirring, such as an (in-line type) emulsifying and dispersing machine (trade name: Mildar MDN303V (manufactured by Taiheiyo Kiko Co., Ltd.)), trade name "Ebara Mildar" (manufactured by Ebara Corporation)), a high-speed emulsifying and dispersing machine (trade name "T.K. Homomixer MARK II type" (manufactured by Primix Corporation)).

[0075] After granulation, the aqueous medium in which the granulated polymerizable monomer composition is dispersed is heated to initiate polymerization.

[0076] The polymerization temperature of the polymerizable monomer composition is preferably 50°C or higher, more preferably 60°C or higher, and preferably 95°C or lower. Also, the reaction time of the polymerization is preferably 1 hour or longer, more preferably 2 hours or longer, and preferably 20 hours or shorter, more preferably 15 hours or shorter.

[0077] After completion of the polymerization, the colored polymer particles can be separated as toner particles from the aqueous dispersion of the colored polymer particles by operations of filtration, washing to remove the dispersion stabilizer, dehydration, and drying according to a conventional method. The operations of filtration, washing, dehydration, and drying are preferably repeated several times as necessary.

[0078] As a cleaning method, when an inorganic compound such as an inorganic hydroxide is used as a dispersion stabilizer, it is preferable to dissolve and remove the dispersion stabilizer in water by adding an acid or an alkali to the aqueous dispersion of toner particles. When a colloid of a hardly water-soluble inorganic hydroxide is used as the dispersion stabilizer, it is preferable to add an acid to adjust the pH of the toner particle aqueous dispersion to 6.5 or less. As the acid to be added, inorganic acids such as sulfuric acid, hydrochloric acid, and nitric acid, and organic acids such as formic acid and acetic acid can be used. However, sulfuric acid is preferable because of its high removal efficiency and low burden on manufacturing equipment.

[0079] For the methods of dehydration and filtration, various known methods and the like can be used and are not particularly limited. For example, centrifugal filtration method, vacuum filtration method, pressure filtration method, etc. can be mentioned.

[0080] In the present invention, the colored polymer particles obtained by the suspension polymerization method can be used as toner as they are. However, by using the colored polymer particles as core particles and forming a shell layer on the outside thereof, a core-shell type toner (capsule toner) can be obtained. For example, by coating core particles containing a resin with a low softening point with a shell layer containing a resin having a higher softening point, a balance can be achieved between lowering the fixing temperature and preventing aggregation during storage.

[0081] There is no particular limitation on the method for producing a core-shell type toner using the colored polymer particles as core particles, and it can be produced by a conventionally known method. The in-situ polymerization method and the phase separation method are preferable from the viewpoint of production efficiency.

[0082] The core-shell type toner by the in-situ polymerization method can be produced, for example, by the following method. A polymerizable monomer for a resin forming a shell layer (shell resin) (shell polymerizable monomer) and, if necessary, other additives for the shell are dissolved or dispersed in deionized water to form an aqueous dispersion of the shell polymerizable monomer. To this aqueous dispersion of the shell polymerizable monomer, a polymerization initiator for polymerizing the shell polymerizable monomer or the like is added, and the mixture is placed in an aqueous medium in which colored polymer particles are dispersed and polymerized to obtain core-shell type toner.

[0083] As the shell polymerizable monomer, those similar to the aforementioned polymerizable monomers can be used, but from the viewpoint of storage stability, the shell layer preferably contains polymethyl methacrylate (PMMA). Therefore, methyl methacrylate is preferable as the shell polymerizable monomer.

[0084] The content of methyl methacrylate in the shell polymerizable monomer is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more, and still more preferably 100 mol% in the shell polymerizable monomer.

[0085] As other additives for the shell, it may contain inorganic fine particles such as silica, aluminum oxide, titanium oxide, zinc oxide, tin oxide, and a crosslinkable polymer having two or more polymerizable functional groups such as a urethane acrylate polymer.

[0086] Examples of the polymerization initiator used for polymerizing the shell polymerizable monomer include water-soluble polymerization initiators such as metal persulfates such as potassium persulfate and ammonium persulfate; azo-based initiators such as 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide] and 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide].

[0087] The amount of the polymerization initiator is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, and preferably 30 parts by mass or less, more preferably 20 parts by mass or less with respect to 100 parts by mass of the shell polymerizable monomer.

[0088] The polymerization temperature of the shell layer is preferably 50°C or higher, more preferably 60°C or higher, and preferably 95°C or lower. Further, the reaction time of the polymerization is preferably 1 hour or longer, more preferably 2 hours or longer, and preferably 20 hours or shorter, more preferably 15 hours or shorter.

[0089] After the completion of the polymerization, in accordance with the conventional method, through operations such as filtration, washing to remove the dispersion stabilizer, dehydration, and drying, the core-shell type toner can be separated from the aqueous dispersion of the core-shell type toner in the same manner as the colored polymer particles.

[0090] The circularity of the toner obtained by the suspension polymerization method is preferably 0.975 or higher, more preferably 0.978 or higher, still more preferably 0.980 or higher, and preferably 0.995 or lower, more preferably 0.992 or lower, still more preferably 0.990 or lower.

[0091] When manufacturing the pulverized toner by the melt-kneading method, for example, after uniformly mixing raw materials containing a binder resin, a colorant, and a release agent with a mixer such as a Henschel mixer, it can be manufactured by melt-kneading with a closed kneader, a single-screw or twin-screw extruder, an open roll type kneader, etc., followed by cooling, pulverization, and classification.

[0092] Examples of the binder resin include vinyl resins such as polyester resins and styrene-acrylic resins, epoxy resins, polycarbonates, polyurethanes, and composite resins containing two or more of these resins. Among these, from the viewpoint of low-temperature fixability, polyester resins are preferred.

[0093] The polyester resin is a polycondensate of an alcohol component and a carboxylic acid component. From the viewpoint of storage stability, the alcohol component preferably contains an alkylene oxide adduct of bisphenol A.

[0094] Examples of the alkylene oxide adduct of bisphenol A include polyoxypropylene adducts of 2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene adducts of 2,2-bis(4-hydroxyphenyl)propane, etc., and the formula (II):

[0095] [Chemical formula]

[0096] (In the formula, OR 6 and R 6 O is an oxyalkylene group, R 6 is an ethylene group and / or a propylene group, x and y represent the average number of moles of alkylene oxide added, and are each a positive number. The value of the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 6 or less, still more preferably 4 or less, and even more preferably 2.5 or less) The compound represented by is preferred.

[0097] The content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and 100 mol% or less.

[0098] Examples of other alcohol components include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, and polyhydric alcohols with 3 or more valences such as bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0099] Examples of the carboxylic acid component include aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and carboxylic acid compounds having three or more valences.

[0100] Examples of the aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0101] Examples of the aliphatic dicarboxylic acid compounds include fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with hydrocarbon groups, glutaric acid, adipic acid, sebacic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0102] Examples of the carboxylic acid compounds having three or more valences include trimellitic acid, pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0103] The alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monohydric carboxylic acid compound.

[0104] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol component and the carboxylic acid component.

[0105] The equivalent ratio (COOH group / OH group) of the carboxy group of the carboxylic acid component to the hydroxy group of the alcohol component is preferably 0.6 or more, more preferably 0.7 or more, still more preferably 0.8 or more, and preferably 1.3 or less, more preferably 1.2 or less.

[0106] The polyester resin can be produced, for example, by polycondensing an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and further, if necessary, in the presence of a cocatalyst, a polymerization inhibitor, etc., preferably at a temperature of 160°C or higher, more preferably 200°C or higher, and preferably 250°C or lower, more preferably 240°C or lower.

[0107] Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropoxybis(triethanolamineate). The amount of the esterification catalyst used is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and preferably 1.5 parts by mass or less, more preferably 1 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the co-catalyst for the esterification catalyst include gallic acid. The amount of the co-catalyst used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the polymerization inhibitor include tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component.

[0108] In the present invention, the polyester resin may be a polyester resin modified to such an extent that its properties are not substantially impaired. Examples of the modified polyester resin include polyester resins grafted or blocked with phenol, urethane, epoxy, etc. by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, etc. Among the modified polyester resins, a urethane-modified polyester resin obtained by extending a polyester resin with a polyisocyanate compound is preferred.

[0109] From the viewpoint of charge stability, the softening point of the polyester resin is preferably 70°C or higher, more preferably 90°C or higher, still more preferably 100°C or higher, and from the viewpoint of low-temperature fixability, it is preferably 170°C or lower, more preferably 160°C or lower, still more preferably 150°C or lower.

[0110] Note that the polyester resin may be composed of resins having different softening points from the viewpoints of low-temperature fixability and fixing width. The difference in the softening points of the two resins is preferably 10°C or more, more preferably 20°C or more, and preferably 60°C or less, more preferably 40°C or less.

[0111] From the viewpoint of the fixing width, the softening point of the polyester resin with a higher softening point (resin AH) is preferably 100°C or more, more preferably 110°C or more, still more preferably 120°C or more, and from the viewpoint of low-temperature fixability, it is preferably 170°C or less, more preferably 160°C or less, still more preferably 150°C or less.

[0112] Also, from the viewpoint of charge stability, the softening point of the polyester resin with a lower softening point (resin AL) is preferably 70°C or more, more preferably 90°C or more, still more preferably 100°C or more, and from the viewpoint of low-temperature fixability, it is preferably 130°C or less, more preferably 125°C or less, still more preferably 120°C or less.

[0113] The mass ratio of resin AH to resin AL (resin AH / resin AL) is preferably 10 / 90 or more, more preferably 20 / 80 or more, still more preferably 30 / 70 or more, and preferably 90 / 10 or less, more preferably 80 / 20 or less, still more preferably 75 / 25 or less.

[0114] From the viewpoint of storage stability, the glass transition temperature of the polyester resin is preferably 40°C or more, more preferably 50°C or more, and from the viewpoint of charge stability, it is preferably 80°C or less, more preferably 70°C or less.

[0115] From the viewpoint of low-temperature fixability, the acid value of the polyester resin is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, and from the viewpoint of charge stability, it is preferably 15 mgKOH / g or less, more preferably 10 mgKOH / g or less.

[0116] The content of the polyester resin is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and 100 mol% or less in the binder resin.

[0117] Also, the content of the binder resin is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 75% by mass or more, and preferably less than 100% by mass, more preferably 98% by mass or less, still more preferably 95% by mass or less in the toner.

[0118] Regarding the types and amounts of the colorant and the release agent, they are the same as those described for the suspension polymerization method.

[0119] The raw materials to be melt-kneaded may contain, in addition to the binder resin, the colorant, and the release agent, charge control agents, magnetic powders, fluidity improvers, conductivity adjusters, reinforcing fillers such as fibrous substances, antioxidants, additives such as cleaning property improvers, etc.

[0120] Regarding the types of the charge control agents, they are the same as those described for the suspension polymerization method.

[0121] From the viewpoint of the charging stability of the toner, the content of the charge control agent is preferably 0.01 part by mass or more, more preferably 0.2 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, still more preferably 2 parts by mass or less with respect to 100 parts by mass of the binder resin. When the charge control agent is a resin (polymeric type), it is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0122] The roundness of the pulverized toner obtained by the melt-kneading method is preferably 0.920 or more, more preferably 0.925 or more, still more preferably 0.930 or more, and preferably 0.980 or less, more preferably 0.975 or less, still more preferably 0.970 or less.

[0123] In the toner of the present invention, in order to improve transferability, it is preferable that an external additive is externally added. 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 melamine resin fine particles and polytetrafluoroethylene resin fine particles, and two or more kinds may be used in combination. Among these, silica is preferable, and from the viewpoint of the transferability of the toner, hydrophobic silica that has been hydrophobically treated is more preferable.

[0124] Examples of the hydrophobizing agent for hydrophobizing the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazane, silicone oil, aminosilane, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0125] From the viewpoints of the chargeability, fluidity, and transferability of the toner, the average particle diameter of the external additive is preferably 5 nm or more, and preferably 250 nm or less, more preferably 200 nm or less, and still more preferably 90 nm or less.

[0126] The external addition treatment by mixing toner particles and an external additive can be performed according to a conventional method, and a mixer such as a Henschel mixer can be used.

[0127] From the viewpoints of the chargeability, fluidity, and transferability of the toner, the content of the external additive is preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more, still more preferably 0.3 part by mass or more, based on 100 parts by mass of the toner particles before being treated with the external additive, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less.

[0128] The volume median particle diameter (D 50 ) is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. In this specification, the volume median particle diameter (D 50It means the particle size at which the cumulative volume frequency calculated by volume fraction reaches 50% when calculated from the smaller particle sizes. When the toner is treated with an external additive, the volume median particle size of the toner particles before treatment with the external additive is defined as the volume median particle size of the toner.

[0129] As described above, at least a combination of yellow toner, cyan toner, magenta toner, and black toner can be used as it is in a single-component development type image forming apparatus, or each color toner can be mixed with a carrier and used in a two-component development type image forming apparatus, respectively.

Examples

[0130] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. Physical properties such as those of resins can be measured by the following methods.

[0131] 〔Number average molecular weight of macromonomer〕 The number average molecular weight is determined by gel permeation chromatography (GPC) method according to the following method. (1) Preparation of sample solution Dissolve the resin in tetrahydrofuran so that the concentration becomes 0.5 g / 100 mL. Then, filter this solution using a fluororesin filter with a pore size of 2 μm (manufactured by Sumitomo Electric Industries, Ltd., trade name: FP-200) to remove insoluble components and obtain a sample solution. (2) Molecular weight measurement Using the following measuring device and analytical column, flow tetrahydrofuran as the eluent at a flow rate of 1 mL per minute and stabilize the column in a thermostat at 40°C. Inject 100 μL of the sample solution there and perform the measurement. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. For the calibration curve at this time, several monodisperse polystyrenes with known molecular weights (manufactured by Tosoh Corporation; 2.63×10 3 、2.06×10 4 、1.02×10 5 、manufactured by GL Sciences Inc.; 2.10×10 3 、7.00×10 3 、5.04×104 Use the one prepared with [[ID=]]) as the standard sample. Measuring device: CO-8010 (trade name, manufactured by Tosoh Corporation) Analysis column: GMH XL +G3000H XL (Both are trade names, manufactured by Tosoh Corporation)

[0132] [Softening point of resin] Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating 1 g of the sample at a heating rate of 6 °C / min, apply a load of 1.96 MPa with a plunger and extrude it from a nozzle with a diameter of 1 mm and a length of 1 mm. Plot the plunger descent amount of the flow tester against the temperature, and take the temperature at which half of the sample has flowed out as the softening point.

[0133] [Maximum peak temperature of endotherm of resin] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 - 0.02 g of the sample into an aluminum pan, cool it from room temperature (25 °C) to 0 °C at a cooling rate of 10 °C / min, and maintain it at 0 °C for 1 minute. Then, measure while heating it from 0 °C to 180 °C at a heating rate of 10 °C / min. Among the observed endothermic peaks, take the temperature of the peak with the largest peak area as the maximum peak temperature of endotherm. In the case of a crystalline resin, take the maximum peak temperature of endotherm as the melting point.

[0134] [Glass transition temperature of resin] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 - 0.02 g of the sample into an aluminum pan, heat it to 200 °C, and then cool it from that temperature to 0 °C at a cooling rate of 10 °C / min. Next, heat the sample from 0 °C to 150 °C at a heating rate of 10 °C / min and measure the endothermic peak. Take the temperature at the intersection of the extension line of the baseline below the maximum peak temperature of endotherm and the tangent line showing the maximum slope from the rising part of the peak to the peak apex as the glass transition temperature.

[0135] [Acid value of resin] Measure in accordance with the method of JIS K 0070:1992. However, only change the measurement solvent from the mixed solvent of ethanol and ether specified in JIS K 0070 to a mixed solvent of acetone and toluene (acetone:toluene = 1:1 (volume ratio)).

[0136] 〔Melting point of release agent〕 Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.02 g of the sample into an aluminum pan, heat it up to 200 °C, and then cool it from 200 °C to 0 °C at a cooling rate of 10 °C / min. Next, heat the sample at a heating rate of 10 °C / min, measure the heat quantity, and take the maximum peak temperature of endotherm as the melting point.

[0137] 〔Average particle diameter of external additive〕 The average particle diameter refers to the number average particle diameter. Measure the particle diameters (average value of major axis and minor axis) of 500 particles from a scanning electron microscope (SEM) photograph, and take their number average value.

[0138] 〔Volume median diameter (D 50 ) of toner〕 · Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) · Aperture diameter: 50 μm · Analysis software: "Multisizer (registered trademark) III Version 3.51" (manufactured by Beckman Coulter, Inc.) · Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) · Dispersion liquid: Prepared by dissolving polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" [manufactured by Kao Corporation, HLB (Griffin) = 13.6] in the electrolyte to adjust to 5% by mass · Dispersion conditions: Add 10 mg of the measurement sample to 5 mL of the above dispersion liquid, disperse it with a ultrasonic disperser (machine name: US-1 manufactured by SND Co., Ltd., output: 80 W) for 1 minute, then add 25 mL of the electrolyte, and further disperse it with the ultrasonic disperser for 1 minute to prepare a sample dispersion liquid. ·Measurement conditions: After adjusting the concentration of the sample dispersion added to 100 mL of the electrolyte so that the particle sizes of 30,000 particles can be measured in 20 seconds, 30,000 particles are measured, and the volume median particle size (D 50 ) is determined from the particle size distribution.

[0139] 〔Circularity of toner particles〕 Measure the circularity of toner particles under the following conditions. ·Measuring device: Flow-type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) ·Dispersion liquid: A solution prepared by dissolving polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Griffin) = 13.6) in deionized water to a concentration of 5% by mass ·Dispersion conditions: Add 10 mg of the measurement sample to 5 mL of the dispersion liquid, disperse it for 1 minute with an ultrasonic disperser (machine name: US-1 manufactured by SND Co., Ltd., output: 80 W), then add 25 mL of deionized water, and further disperse it for 1 minute with an ultrasonic disperser to prepare a sample dispersion liquid. ·Measurement mode: HPF measurement mode

[0140] Production example 1 of alkenyl succinic anhydride (1) Using propylene tetramer (manufactured by Nippon Oil Corporation, trade name: "Light Tetramer"), fractional distillation was carried out under heating conditions of 183 to 208 °C to obtain an alkylene compound (a). The obtained alkylene compound (a) had 40 peaks in the gas chromatography-mass spectrometry described below. The distribution of the alkylene compound was measured according to the analysis by gas chromatography-mass spectrometry of alkylene compound A in JP-A-2014-013384, and C9H 18 : 0.5% by mass, C 10 H 20 : 4% by mass, C 11 H 22 : 20% by mass, C 12 H 24 : 66% by mass, C 13 H 26 : 9% by mass, C 14 H 28: It was 0.5 mass% (the number of peaks corresponding to an alkylene compound having 9 to 14 carbon atoms was 6).

[0141] (2) 542.4 g of alkylene compound (a), 157.2 g of maleic anhydride, 0.4 g of antioxidant “Chellex - O” (manufactured by Sakai Chemical Industry Co., Ltd., Triisooctyl phosphite), and 0.1 g of butylhydroquinone as a polymerization inhibitor were charged into a 1 L autoclave manufactured by Nitto Koki Co., Ltd. Pressurized nitrogen substitution (0.2 MPaG) was repeated 3 times. After starting stirring at 60°C, the temperature was raised to 230°C over 1 hour and reacted for 6 hours. The pressure at the time of reaching the reaction temperature was 0.3 MPaG. After completion of the reaction, it was cooled to 80°C, returned to normal pressure (101.3 kPa), and transferred to a 1 - liter four - necked flask. The temperature was raised to 180°C with stirring, and the remaining alkylene compound was distilled off at 1.3 kPa over 1 hour. Subsequently, after cooling to room temperature (25°C) and returning to normal pressure (101.3 kPa), 406.1 g of the target alkenyl succinic anhydride A was obtained. The average molecular weight of alkenyl succinic anhydride A determined from the acid value was 268.

[0142] Resin Production Example 1 The alcohol component, carboxylic acid component other than trimellitic anhydride, esterification catalyst, and co - catalyst shown in Table 1 were placed in a 5 - liter four - necked flask equipped with a nitrogen inlet tube, a down - flow condenser having a water removal tube, a stirrer, and a thermocouple. After raising the temperature to 235°C under a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. Then, the temperature was lowered to 210°C, trimellitic anhydride shown in Table 1 was added, reacted at 210°C for 1 hour, and further reacted at 210°C under a reduced pressure of 10 kPa until the softening point shown in Table 1 was reached to obtain a polyester resin (Resin A1). The physical properties are shown in Table 1.

[0143] Resin Production Example 2 The alcohol component, carboxylic acid component, esterification catalyst and co-catalyst shown in Table 1 were placed in a 5-liter four-necked flask equipped with a nitrogen inlet tube, a downflow condenser having a water removal tube, a stirrer and a thermocouple. After heating to 235°C under a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. Further, the reaction was carried out at 235°C under a reduced pressure of 10 kPa until the softening point described in Table 1 was reached to obtain a polyester resin (resin A2). The physical properties are shown in Table 1.

[0144]

Table 1

[0145] Production Example 1 of Yellow Toner (1) Preparation of Polymerizable Monomer Composition for Core 75 parts by mass of styrene and 25 parts by mass of n-butyl acrylate as polymerizable monomers, and 7 parts by mass of C.I. Pigment Yellow 93 (manufactured by Sankyo Chemical Co., Ltd., trade name: CROMOPHTAL YELLOW D1040) as a colorant were dispersed using a media type emulsifying and dispersing machine to obtain a polymerizable monomer mixture. To the obtained polymerizable monomer mixture, 0.75 parts by mass of a polymer type positive charge control agent (manufactured by Fujikura Kasei Co., Ltd., trade name: ACRIVEST FCA-161P, a quaternary ammonium salt-containing resin, softening point: 110°C, glass transition temperature: 60°C), 8 parts by mass of ester wax "WEP-8" (manufactured by NOF Corporation, pentaerythritol tetrabehenate, melting point: 80°C) as a release agent, 0.3 parts by mass of a polymethacrylic acid ester macromonomer (manufactured by Toagosei Co., Ltd., trade name: AA6, number average molecular weight: 6,000) as a macromonomer, 0.6 parts by mass of divinylbenzene as a crosslinkable polymerizable monomer, and 1.6 parts by mass of tert-dodecyl mercaptan as a chain transfer agent were added, followed by mixing and dissolving to prepare a polymerizable monomer composition.

[0146] (2) Preparation of Aqueous Dispersion Medium An aqueous solution prepared by dissolving 10.4 parts by mass of magnesium chloride in 280 parts by mass of deionized water was gradually added with stirring to an aqueous solution prepared by dissolving 7.3 parts by mass of sodium hydroxide in 50 parts by mass of deionized water to prepare a magnesium hydroxide colloid dispersion.

[0147] (3) Preparation of the polymerizable monomer for the shell 2 parts by mass of methyl methacrylate and 130 parts by mass of deionized water were finely dispersed using an ultrasonic emulsifier to prepare an aqueous dispersion of the polymerizable monomer for the shell.

[0148] (4) Granulation process The polymerizable monomer composition obtained in (1) was charged into the magnesium hydroxide colloid dispersion obtained in (2) at room temperature, and the mixture was further stirred until the droplets were stable. Then, 4.4 parts by mass of tert-butyl peroxy-2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perbutyl O), used as a polymerization initiator, was added thereto. The dispersion to which the polymerization initiator was added was subjected to high-shear stirring at a rotational speed of 15,000 r / min using an in-line emulsifying disperser (manufactured by Taiheiyo Kiko Co., Ltd., trade name: Mildar MDN303V) to form droplets of the polymerizable monomer composition.

[0149] (5) Suspension polymerization process: The dispersion containing the droplets of the polymerizable monomer composition obtained in (4) was placed in a reactor, and the temperature was raised to 90 °C to carry out a polymerization reaction. After the polymerization conversion rate reached almost 100%, a solution prepared by dissolving 0.1 part by mass of 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide] (manufactured by Fujifilm Wako Pure Chemical Corporation, trade name: VA-086, water-soluble initiator), used as a polymerization initiator for the shell, in the aqueous dispersion of the polymerizable monomer for the shell obtained in (3) was added to the reactor. Subsequently, the mixture was held at 95 °C for 4 hours to continue the polymerization, and then cooled with water to stop the reaction, obtaining an aqueous dispersion of toner particles.

[0150] (6) Post-treatment process The aqueous dispersion of toner particles obtained in (5) was stirred at room temperature while sulfuric acid was added dropwise until the pH reached 6.0 or lower for acid washing. Subsequently, filtration separation was performed, 500 parts by mass of deionized water was added to the obtained solid content to re-slurry it, and the water washing treatment (washing, filtration, and dehydration) was repeated several times. Subsequently, filtration separation was performed, the obtained solid content was placed in a container of a dryer, and drying was performed at 40 °C for 24 hours to obtain toner particles with a volume average particle diameter (D 50 ) of 6.3 μm and a circularity of 0.985.

[0151] (7) External addition step To 100 parts by mass of the toner particles obtained in (6), 1 part by mass of hydrophobic silica (manufactured by Cabot Corporation, product name "TG820F", hydrophobizing agent: HMDS and cyclic silazane, average particle diameter: 8 nm) and 1 part by mass of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., product name "NA50H", hydrophobizing agent: HMDS and aminosilane, average particle diameter: 30 nm) were added, and they were mixed for 3 minutes at a rotational speed of 3000 r / min (peripheral speed 32 m / sec) using a Henschel mixer (manufactured by Nippon Coke Industry Co., Ltd.) to obtain core-shell type yellow toner (Y1).

[0152] Production Example 2 of Yellow Toner As a release agent, instead of ester wax "WEP-8", 8 parts by mass of ester wax "WEP-6" (manufactured by NOF Corporation, pentaerythritol tetrastearate, melting point: 76 °C) was used, and yellow toner (Y2) was obtained in the same manner as in Production Example 1.

[0153] Production Example 3 of Yellow Toner As a release agent, instead of ester wax "WEP-8", 8 parts by mass of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point: 75 °C) was used, and yellow toner (Y3) was obtained in the same manner as in Production Example 1.

[0154] Production Example 4 of Yellow Toner (1) Preparation of polymerizable monomer composition 75 parts by mass of styrene and 25 parts by mass of n-butyl acrylate as the coincident monomer, and 7 parts by mass of C.I. Pigment Yellow 93 (manufactured by Sankyo Chemical Co., Ltd., trade name: CROMOPHTAL YELLOW D1040) as the colorant were dispersed using a media-type emulsifying and dispersing machine to obtain a polymerizable monomer mixture. To the obtained polymerizable monomer mixture, 0.75 parts by mass of a polymer-type positive charge control agent (manufactured by Fujikura Kasei Co., Ltd., trade name: ACRABASE FCA-161P, a quaternary ammonium salt-containing resin, softening point: 110 °C, glass transition temperature: 60 °C), 8 parts by mass of ester wax "WEP-8" (manufactured by NOF Corporation, pentaerythritol tetrabehenate, melting point: 80 °C) as a release agent, 0.3 parts by mass of a polymethacrylic acid ester macromonomer (manufactured by Toagosei Co., Ltd., trade name: AA6, number average molecular weight: 6,000) as a macromonomer, 0.6 parts by mass of divinylbenzene as a crosslinkable polymerizable monomer, and 1.6 parts by mass of tert-dodecyl mercaptan as a chain transfer agent were added, and then mixed and dissolved to prepare a polymerizable monomer composition.

[0155] (2) Preparation of aqueous dispersion medium An aqueous solution in which 10.4 parts by mass of magnesium chloride was dissolved in 280 parts by mass of deionized water was gradually added with an aqueous solution in which 7.3 parts by mass of sodium hydroxide was dissolved in 50 parts by mass of deionized water with stirring to prepare a magnesium hydroxide colloid dispersion.

[0156] (3) Granulation process The polymerizable monomer composition obtained in (1) was charged into the magnesium hydroxide colloid dispersion obtained in (2) at room temperature, and further stirred until the droplets were stabilized. Then, 4.4 parts by mass of tert-butyl peroxy-2-ethylhexanoate (manufactured by NOF Corporation, trade name: PERBUTYL O) was added thereto as a polymerization initiator. The dispersion to which the polymerization initiator was added was subjected to high-shear stirring at a rotational speed of 15,000 r / min using an in-line type emulsifying and dispersing machine (manufactured by Taiheiyo Kiko Co., Ltd., trade name: MYLDER MDN303V) to form droplets of the polymerizable monomer composition.

[0157] (4) Suspension polymerization process The dispersion containing droplets of the polymerizable monomer composition obtained in (3) was placed in a reactor, heated to 90 °C, and subjected to a polymerization reaction. Subsequently, it was maintained at 95 °C for 4 hours to further continue the polymerization, and then cooled with water to stop the reaction, obtaining an aqueous dispersion of toner particles.

[0158] (5) Post-treatment step To the aqueous dispersion of toner particles obtained in (4), sulfuric acid was added dropwise with stirring at room temperature, and acid washing was performed until the pH became 6.0 or less. Subsequently, filtration separation was carried out, 500 parts by mass of deionized water was added to the obtained solid content to re-slurry it, and the water washing treatment (washing, filtration, and dehydration) was repeated several times. Then, filtration separation was carried out, the obtained solid content was put into a container of a dryer, and dried at 40 °C for 24 hours. The toner particles having a volume average particle diameter (D 50 ) of 6.2 μm and a circularity of 0.984 were obtained.

[0159] (6) External addition step To 100 parts by mass of the toner particles obtained in (5), 1 part by mass of hydrophobic silica (manufactured by Cabot Corporation, product name "TG820F", hydrophobizing agent: HMDS and cyclic silazane, average particle diameter: 8 nm) and 1 part by mass of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., product name "NA50H", hydrophobizing agent: HMDS and aminosilane, average particle diameter: 30 nm) were added, and mixed using a Henschel mixer (manufactured by Nippon Coke Industry Co., Ltd.) at a rotation speed of 3000 r / min (peripheral speed 32 m / sec) for 3 minutes to obtain yellow toner (Y4).

[0160] Production Example 5 of Yellow Toner 60 parts by mass of Resin A1 and 40 parts by mass of Resin A2 as a binder resin, 7 parts by mass of C.I. Pigment Yellow 93 (manufactured by Sankyo Chemical Co., Ltd., product name: CROMOPHTAL YELLOW D1040) as a colorant, 8 parts by mass of ester wax "WEP-8" (manufactured by NOF Corporation, pentaerythritol tetrabehenate, melting point: 80 °C) as a release agent, and 10 parts by mass of a polymer type positive charge control agent (manufactured by Fujikura Kasei Co., Ltd., product name: FCA-201-PS, a resin containing a quaternary ammonium salt, softening point: 119 °C, glass transition temperature: 65 °C) were mixed using a Henschel mixer.

[0161] The obtained mixture was melt-kneaded at a screw rotation speed of 200 r / min and a barrel set temperature of 100°C using a co-rotating twin-screw extruder with a total length of the kneading section of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm to obtain a melt-kneaded product. The supply rate of the mixture was 20 kg / h, and the average residence time was about 18 seconds.

[0162] After cooling and coarsely pulverizing the obtained melt-kneaded product, it was finely pulverized with a jet mill and classified using an air classifier (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain toner particles with a volume median diameter (D 50 ) of 6.3 μm and a circularity of 0.945.

[0163] To 100 parts by mass of the obtained toner particles, 1 part by mass of hydrophobic silica (manufactured by Cabot Corporation, product name "TG820F", hydrophobizing agent: HMDS and cyclic silazane, average particle diameter: 8 nm) and 1 part by mass of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., product name "NA50H", hydrophobizing agent: HMDS and aminosilane, average particle diameter: 30 nm) were added as external additives, and they were mixed for 3 minutes at a rotation speed of 3000 r / min (peripheral speed 32 m / sec) using a Henschel mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) to obtain yellow toner (Y5).

[0164] Production Example 6 of Yellow Toner Yellow toner (Y6) shown in Table 2 was obtained in the same manner as in Production Example 1 of yellow toner, except that 7 parts by mass of C.I. Pigment Yellow 214 (manufactured by Hoechst Color Japan Co., Ltd., trade name: PV FAST Yellow H9G) was used instead of C.I. Pigment Yellow 93 as the colorant.

[0165] Production Example 7 of Yellow Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of C.I. Pigment Yellow 214 (manufactured by Hoechst Japan Ltd., trade name: PV FAST Yellow H9G) was used, and as a release agent, instead of ester wax "WEP-8", 8 parts by mass of ester wax "WEP-3" (manufactured by NOF Corporation, behenyl behenate, melting point: 70 °C) was used. Otherwise, in the same manner as in Production Example 1 of the yellow toner, the yellow toner (Y7) shown in Table 2 was obtained.

[0166] Production Example 1 of Magenta Toner As a colorant, instead of C.I. Pigment Yellow 93, 3 parts by mass of C.I. Pigment Red 122 (manufactured by Clariant, trade name: Toner Magenta E) and 3 parts by mass of C.I. Pigment Violet 19 (manufactured by Clariant, trade name: Ink Jet Magenta E5B02) were used. Otherwise, in the same manner as in Production Example 1 of the yellow toner, the magenta toner (M1) shown in Table 2 was obtained.

[0167] Production Example 2 of Magenta Toner As a colorant, instead of C.I. Pigment Yellow 93, 3 parts by mass of C.I. Pigment Red 122 (manufactured by Clariant, trade name: Toner Magenta E) and 3 parts by mass of C.I. Pigment Violet 19 (manufactured by Clariant, trade name: Ink Jet Magenta E5B02) were used. Otherwise, in the same manner as in Production Example 2 of the yellow toner, the magenta toner (M2) shown in Table 2 was obtained.

[0168] Production Example 3 of Magenta Toner As a colorant, instead of C.I. Pigment Yellow 93, 3 parts by mass of C.I. Pigment Red 122 (manufactured by Clariant, trade name: Toner Magenta E) and 3 parts by mass of C.I. Pigment Violet 19 (manufactured by Clariant, trade name: Ink Jet Magenta E5B02) were used. Otherwise, in the same manner as in Production Example 3 of the yellow toner, the magenta toner (M3) shown in Table 2 was obtained.

[0169] Production Example 4 of Magenta Toner As the colorant, instead of C.I. Pigment Yellow 93, 3 parts by mass of C.I. Pigment Red 122 (manufactured by Clariant, trade name: Toner Magenta E) and 3 parts by mass of C.I. Pigment Violet 19 (manufactured by Clariant, trade name: Ink Jet Magenta E5B02) were used. Otherwise, in the same manner as in Production Example 4 of Yellow Toner, the magenta toner (M4) shown in Table 2 was obtained.

[0170] Production Example 5 of Magenta Toner As the colorant, instead of C.I. Pigment Yellow 93, 3 parts by mass of C.I. Pigment Red 122 (manufactured by Clariant, trade name: Toner Magenta E) and 3 parts by mass of C.I. Pigment Violet 19 (manufactured by Clariant, trade name: Ink Jet Magenta E5B02) were used. Otherwise, in the same manner as in Production Example 5 of Yellow Toner, the magenta toner (M5) shown in Table 2 was obtained.

[0171] Production Example 6 of Magenta Toner As the colorant, instead of C.I. Pigment Yellow 93, 3 parts by mass of C.I. Pigment Red 122 (manufactured by Clariant, trade name: Toner Magenta E) and 3 parts by mass of C.I. Pigment Violet 19 (manufactured by Clariant, trade name: Ink Jet Magenta E5B02) were used. As the release agent, instead of ester wax "WEP - 8", 8 parts by mass of ester wax "WEP - 3" (manufactured by NOF Corporation, behenyl behenate, melting point: 70°C) were used. Otherwise, in the same manner as in Production Example 1 of Yellow Toner, the magenta toner (M6) shown in Table 2 was obtained.

[0172] Production Example 1 of Cyan Toner As the colorant, instead of C.I. Pigment Yellow 93, 5 parts by mass of C.I. Pigment Blue 15 (manufactured by DIC Corporation, trade name "Fastogen Blue GCTF") were used. Otherwise, in the same manner as in Production Example 1 of Yellow Toner, the cyan toner (C1) shown in Table 2 was obtained.

[0173] Production Example 2 of Cyan Toner As the colorant, instead of C.I. Pigment Yellow 93, 5 parts by mass of C.I. Pigment Blue 15 (manufactured by DIC Corporation, trade name "Fastogen Blue GCTF") was used. Otherwise, in the same manner as in Production Example 2 of Yellow Toner, the cyan toner (C2) shown in Table 2 was obtained.

[0174] Production Example 3 of Cyan Toner As the colorant, instead of C.I. Pigment Yellow 93, 5 parts by mass of C.I. Pigment Blue 15 (manufactured by DIC Corporation, trade name "Fastogen Blue GCTF") was used. Otherwise, in the same manner as in Production Example 3 of Yellow Toner, the cyan toner (C3) shown in Table 2 was obtained.

[0175] Production Example 4 of Cyan Toner As the colorant, instead of C.I. Pigment Yellow 93, 5 parts by mass of C.I. Pigment Blue 15 (manufactured by DIC Corporation, trade name "Fastogen Blue GCTF") was used. Otherwise, in the same manner as in Production Example 4 of Yellow Toner, the cyan toner (C4) shown in Table 2 was obtained.

[0176] Production Example 5 of Cyan Toner As the colorant, instead of C.I. Pigment Yellow 93, 5 parts by mass of C.I. Pigment Blue 15 (manufactured by DIC Corporation, trade name "Fastogen Blue GCTF") was used. Otherwise, in the same manner as in Production Example 5 of Yellow Toner, the cyan toner (C5) shown in Table 2 was obtained.

[0177] Production Example 6 of Cyan Toner As the colorant, instead of C.I. Pigment Yellow 93, 5 parts by mass of C.I. Pigment Blue 15 (manufactured by DIC Corporation, trade name "Fastogen Blue GCTF") was used, and the amount of the mold release agent used was changed to 12 parts by mass. Otherwise, in the same manner as in Production Example 1 of Yellow Toner, the cyan toner (C6) shown in Table 2 was obtained.

[0178] Production Example 7 of Cyan Toner As a colorant, instead of C.I. Pigment Yellow 93, 5 parts by mass of C.I. Pigment Blue 15 (manufactured by DIC Corporation, trade name "Fastogen Blue GCTF") was used. As a release agent, instead of ester wax "WEP-8", 8 parts by mass of ester wax "WEP-3" (manufactured by NOF Corporation, behenyl behenate, melting point: 70°C) was used. Otherwise, in the same manner as in Production Example 1 of the yellow toner, the cyan toner (C7) shown in Table 2 was obtained.

[0179] Production Example 1 of Black Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "#25B") was used. Otherwise, in the same manner as in Production Example 1 of the yellow toner, except that the amount of the release agent used was changed to 12 parts by mass, the black toner (K1) shown in Table 2 was obtained.

[0180] Production Example 2 of Black Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "#25B") was used. Otherwise, in the same manner as in Production Example 2 of the yellow toner, except that the amount of the release agent used was changed to 12 parts by mass, the black toner (K2) shown in Table 2 was obtained.

[0181] Production Example 3 of Black Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "#25B") was used. Otherwise, in the same manner as in Production Example 3 of the yellow toner, except that the amount of the release agent used was changed to 12 parts by mass, the black toner (K3) shown in Table 2 was obtained.

[0182] Production Example 4 of Black Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "#25B") was used. Otherwise, in the same manner as in Production Example 4 of the yellow toner, except that the amount of the release agent used was changed to 12 parts by mass, the black toner (K4) shown in Table 2 was obtained.

[0183] Production Example 5 of Black Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "#25B") was used, and the amount of the release agent was changed to 12 parts by mass. Otherwise, in the same manner as in Production Example 5 of Yellow Toner, the black toner (K5) shown in Table 2 was obtained.

[0184] Production Example 6 of Black Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "#25B") was used, and the amount of the release agent was changed to 15 parts by mass. Otherwise, in the same manner as in Production Example 1 of Yellow Toner, the black toner (K6) shown in Table 2 was obtained.

[0185] Production Example 7 of Black Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "#25B") was used. Otherwise, in the same manner as in Production Example 1 of Yellow Toner, the black toner (K7) shown in Table 2 was obtained.

[0186] Production Example 8 of Black Toner As a colorant, instead of C.I. Pigment Yellow 93, 7 parts by mass of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name "#25B") was used. As a release agent, instead of 7 parts by mass of ester wax "WEP - 8", 15 parts by mass of ester wax "WEP - 3" (manufactured by NOF Corporation, behenyl behenate, melting point: 70°C) was used. Otherwise, in the same manner as in Production Example 1 of Yellow Toner, the black toner (K8) shown in Table 2 was obtained.

[0187] [Table 2]

[0188] Examples 1 to 11 and Comparative Examples 1 and 2 A toner set was prepared by combining the yellow toner, magenta toner, cyan toner, and black toner shown in Table 3.

[0189] Test Example 1 [Low-temperature Fixing Property] (1) Low-temperature Fixing Property at High Speed A commercially available non-magnetic one-component color printer (manufactured by Brother Industries, Ltd., HL-3240CDW) was modified so that an unfixed image could be taken out, and a solid image was printed so that the yellow toner was 0.30 to 0.40 mg / cm on the paper surface. 2 The same paper was repeatedly printed with three colors of toner (magenta toner, cyan toner, and black toner) to obtain an unfixed image with four colors of toner overlapped.

[0190] Next, a printer with the fuser modified to be temperature-variable and printing-speed-variable was prepared. The temperature of the fuser was set to 150°C, and the toner was fixed at a speed of 0.8 seconds per sheet in the vertical A4 direction to obtain a printed matter. In the same way, the temperature of the fuser was increased by 5°C each time to fix the toner and obtain a printed matter.

[0191] Regarding the fixed image, after the image part (solid patch part) of the paper was bent by hand, the paper was opened and the peeling width of the toner when the part was rubbed with a finger was measured. The lowest temperature at which the peeling width of the toner was 1 mm or less was taken as the minimum fixing temperature, and the low-temperature fixing property was evaluated. The results are shown in Table 3.

[0192] (2) Low-temperature Fixing Property at Normal Speed The low-temperature fixing property at normal speed was evaluated in the same manner as in (1), except that the fixing speed was changed to 2.0 seconds per sheet in the vertical A4 direction. The results are shown in Table 3.

[0193] Test Example 2 [Mottle on Paper Surface] A toner set of yellow toner, cyan toner, magenta toner, and black toner was installed in a modified color printer for non-magnetic one-component (manufactured by Brother Industries, Ltd., HL-3240CDW) used in Test Example 1, and it was left standing in an environment of 25°C / 50%RH for 15 hours. Then, 1,000 images with a printing rate of 1% for each color were printed in the same environment. Next, white solid printing (printing rate 0%) was performed, and the whiteness of the paper surface before printing and the paper surface printed with white solid was measured with an X-Rite eXact (manufactured by X-Rite), and ΔE (whiteness of white solid printed paper surface - whiteness of paper surface before printing) was calculated to evaluate the fogging on the paper surface. The results are shown in Table 3. The closer ΔE is to 0, the better.

[0194]

Table 3

[0195] From the above results, by comparing Examples 1 to 5, 8 to 11 with Comparative Examples 1 and 2, it can be seen that by combining black toner with a large amount of release agent, low-temperature fixability and suppression of fogging on the paper surface are improved. In particular, regarding low-temperature fixability, it can be seen that even if it is the same level at normal speed, it is improved by using the toner set of the examples under high-speed conditions. Also, from the comparison between Example 1 and Example 6, it can be seen that among polymer toners, when it is of the core-shell type, the effect of suppressing fogging on the paper surface is particularly remarkable. Further, from the comparison between Example 1 and Example 7, it can be seen that not only polymer toners but also crushed toners have good low-temperature fixability and fogging on the paper surface is also suppressed.

Industrial Applicability

[0196] The toner set for developing electrostatic latent images of the present invention is suitably used for developing latent images formed in electrophotography, electrostatic recording, electrostatographic printing, etc.

Claims

1. An electrostatic charge image developing toner set including yellow toner, cyan toner, magenta toner, and black toner, which contains a binder resin, a colorant, and a release agent, and in the comparison of the content of the release agent with respect to 100 parts by mass of the binder resin, among the above-mentioned yellow toner, cyan toner, magenta toner, and black toner, the content of the release agent in the black toner is the highest. An electrostatic charge image developing toner set.

2. The electrostatic charge image developing toner set according to claim 1, wherein the difference between the content of the release agent in the black toner and the maximum content of the release agent in the yellow toner, cyan toner, and magenta toner is 1 part by mass or more and 20 parts by mass or less as the content of the release agent with respect to 100 parts by mass of the binder resin.

3. The electrostatic charge image developing toner set according to claim 1 or 2, wherein the yellow toner, cyan toner, magenta toner, and black toner are positively chargeable toners.

4. The electrostatic charge image developing toner set according to claim 1 or 2, wherein the release agent contains an ester wax.

5. The electrostatic charge image developing toner set according to claim 1 or 2, wherein the yellow toner, cyan toner, magenta toner, and black toner are core-shell type toners in which core particles are coated with a shell layer.

6. The electrostatic charge image developing toner set according to claim 5, wherein the shell layer contains methyl polymethacrylate.

7. The electrostatic charge image developing toner set according to claim 1 or 2, wherein the yellow toner, cyan toner, magenta toner, and black toner are toners obtained by a suspension polymerization method.

8. A method for preparing an electrostatic charge image developing toner set by combining at least yellow toner, cyan toner, magenta toner, and black toner, which contains a binder resin, a colorant, and a release agent, and in the comparison of the content of the release agent with respect to 100 parts by mass of the binder resin, among the above-mentioned yellow toner, cyan toner, magenta toner, and black toner, the content of the release agent in the black toner is the highest. A method for preparing an electrostatic charge image developing toner set.

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