JP2011112899A - Method for producing polymerization toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently produce a polymerization toner having a good balance in fixing property, hot offset property, durability and weatherability. <P>SOLUTION: This method includes a polymerization step and an external additive addition step. In the polymerization step, a polymerizable monomer which is radical-polymerizable in an aqueous medium containing a dispersion stabilizer is polymerized with a polymerizable monomer composition containing a compound expressed by formula (1) and/or formula (2). In formulae (1) and (2), R<SP>1</SP>to R<SP>3</SP>, R<SP>6</SP>to R<SP>8</SP>, and R<SP>13</SP>to R<SP>15</SP>each independently represent one selected from a group consisting of a hydrogen atom, 1-6C straight-chain or branched alkyl group and phenyl group; R<SP>4</SP>and R<SP>5</SP>each independently represent a 3-12C straight-chain or branched alkyl group which may have a substituent, wherein the substituent is one selected from a group consisting of a phenyl group which may have a substituent, dialkylphosphono group having a 1-6C alkyl group, and trialkylsilyl group having a 1-6C alkyl group; and R<SP>9</SP>to R<SP>12</SP>each independently represent a 2-12C straight-chain or branched alkyl group which may have a substituent, wherein the substituent is one selected from a group consisting of a phenyl group, dialkylphosphono group having a 1-6C alkyl group, and trialkylsilyl group having a 1-6C alkyl group, and R<SP>9</SP>and R<SP>10</SP>, or R<SP>11</SP>and R<SP>12</SP>may form a spiro ring; and X represents one selected from a group consisting of CR<SP>13</SP>R<SP>14</SP>, C=O, NR<SP>15</SP>, O and S. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a polymerized toner, and more particularly to a method for producing a polymerized toner for developing an electrostatic latent image formed by electrophotography, electrostatic recording, or the like.

  In an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus, an electrostatic latent image formed on a photoreceptor is first developed with toner. Next, the formed toner image is transferred onto a transfer material such as paper as necessary, and then fixed by a method such as heating or pressing.

  In recent years, with the increase in speed and color of image forming apparatuses, toners are required to have low-temperature fixability and durability. In addition, since the fixed image (printed material) is sometimes exposed to the outdoors, weather resistance has also been required.

  The toner as a developer used in such an image forming apparatus is classified into a pulverized toner and a polymerized toner according to a manufacturing method. Polymerized toners produced using polymer particles obtained by the polymerization reaction can be reduced in particle size, have a narrow particle size distribution, and have excellent image reproducibility, as well as encapsulating release agents and capsules. Today, it is generally used in high-speed models because it is easy to implement. Polymerized toners are roughly classified into emulsion polymerization toners and suspension polymerization toners depending on the polymerization method.

  In the suspension polymerization toner, a polymerizable monomer composition is prepared by dissolving or dispersing a colorant, a charge control agent, a release agent, and the like in a polymerizable monomer as a binder resin raw material, if necessary. After being obtained, the monomer composition is suspended in an aqueous dispersion medium containing a dispersion stabilizer, a polymerization initiator and the like, and heated to a predetermined temperature to initiate polymerization. It is known to obtain polymer particles by filtering, washing, dehydrating and drying the particles, and then adding an external additive to the polymer particles.

  The emulsion polymerization toner is obtained by associating particles of a binder resin containing a polar group obtained by emulsion polymerization with particles containing a colorant, a charge control agent and the like, and then aggregating polymer particles. It is known that polymer particles are obtained by filtering, washing, dehydrating and drying, and then adding an external additive to the polymer particles to obtain a polymer toner.

  As a fixing method used in the image forming apparatus, there are fixing methods such as pressure roller fixing, heating roller fixing, and oven heating fixing. Among these, a heating roller fixing method in which a toner image on a transfer medium such as paper is passed between heating rollers is preferably employed from the viewpoint of image quality or thermal efficiency. In the heating roller fixing method, since electric power is used to heat the roller, low temperature fixing property (low toner fixing temperature) is required from the viewpoint of energy saving. At the same time, high temperature hot offset property (offset width is low). Wide) and printing durability (capable of continuous printing) are also required. Conventionally, it has been difficult to efficiently produce a polymerized toner that simultaneously satisfies these requirements.

  Patent Document 1 discloses a toner and a toner manufacturing method in which a binder resin composed of resin particles containing at least crosslinked resin fine particles and colorant particles are granulated in an aqueous medium. Patent Document 2 includes an amorphous polyester resin, a crystalline polyester resin, a release agent, and a colorant. The specific amount of the crystalline polyester resin is contained, and the amount of components dissolved in methanol is based on the total amount of toner. An electrostatic charge image developing toner having a content of 1% by mass or less is disclosed. These toners are disclosed to have a low fixing temperature and excellent hot offset resistance. However, as the printing speed becomes higher, their properties are insufficient, and in a high-temperature and high-humidity environment. It was found that the durability was insufficient.

  Patent Document 3 discloses a binder obtained by polymerizing a polymerizable monomer composition in an aqueous medium in the presence of (1) a thiazolethio compound, (2) a thiuram compound, or (3) a dithiocarbamic acid compound. Disclosed are a toner containing a resin, a colorant and a charge control agent, and a thiazolyl disulfide compound or thiuram disulfide compound, and a method for producing the toner. The toner has a low fixing temperature and excellent hot offset resistance. Is disclosed. However, from the study by the present inventors, it has been found that this toner has insufficient durability under a high temperature and high humidity environment.

JP 2005-91704 A JP 2008-209489 A International Publication No. 02/0777717

  The present inventors have earnestly considered that the molecular weight and molecular weight distribution of the binder resin constituting the polymer particles obtained by the polymerization reaction have a great influence on the performance of the polymerized toner. We proceeded with the examination. The polymerization reaction of radically polymerizable monomers in aqueous media is affected by various factors such as the chemical structure of the polymerization initiator used, radical generating ability, and affinity with polymerizable monomers and aqueous media. Therefore, the mechanism of action of the radical polymerization initiator including the search for a polymerization initiator having a novel structure was examined, and the control of the molecular weight and molecular weight distribution of the binder resin constituting the polymer particles was studied.

  As a result, polymer particles are formed in the presence of a specific nitrogen-containing compound, thereby efficiently producing a polymer toner that has a high balance of low-temperature fixability, high-temperature hot offset property, printing durability, and weather resistance. Based on this finding, the present inventors have found that the present invention can be manufactured.

  Thus, the method for producing a polymerized toner of the present invention comprises a polymerizable monomer capable of radical polymerization, a compound represented by formula (1), and a formula (2) in an aqueous medium containing a dispersion stabilizer or an emulsifier. A polymerization step of polymerizing a polymerizable monomer composition containing at least one compound selected from the group consisting of the compounds represented by the above to form polymer particles, and external addition to the resulting polymer particles A method for producing a polymerized toner including an external additive adding step of adding an additive.

(Here, R ^{1 to} R ³ are each independently one selected from the group consisting of a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a phenyl group,
R ⁴ and R ⁵ are each independently a C 3-12 linear or branched alkyl group which may have a substituent, and the substituent may have a substituent. It is one selected from the group consisting of a phenyl group, a dialkylphosphono group having 1 to 6 carbon atoms in the alkyl group, and a trialkylsilyl group having 1 to 6 carbon atoms in the alkyl group. )

(Here, R ^{6 to} R ⁸ are each independently one selected from the group consisting of a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a phenyl group,
R ^{9 to} R ¹² are each independently a linear or branched alkyl group having 2 to 12 carbon atoms which may have a substituent, and the substituent has a carbon number of a phenyl group or an alkyl group. 1 to 6 dialkylphosphono groups and one selected from the group consisting of trialkylsilyl groups having 1 to 6 carbon atoms in the alkyl group, R ⁹ and R ¹⁰ , or R ¹¹ and R ¹² are May form a spiro ring,
X is one selected from the group consisting of CR ¹³ R ¹⁴ , C═O, NR ¹⁵ , O and S, and each of R ^{13 to} R ¹⁵ independently represents a hydrogen atom, or a carbon number of 1 to 6 A linear or branched alkyl group, and a phenyl group. )

In the method for producing a polymerized toner of the present invention, in Formula (1), R ^{1 to} R ³ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ⁴ and R ⁵ are Each independently a branched alkyl group having 3 to 7 carbon atoms which may have a substituent, wherein the substituent is a phenyl group or a dialkylphosphono group having 1 to 6 carbon atoms in the alkyl group. And a method for producing a polymerized toner, wherein the alkyl group is one selected from the group consisting of trialkylsilyl groups having 1 to 6 carbon atoms.

Furthermore, the method for producing the polymerized toner of the present invention includes the following formula (2):
R ^{6 to} R ⁸ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
R ^{9 to} R ¹² are each independently a linear or branched alkyl group having 2 to 4 carbon atoms, and R ⁹ and R ¹⁰ , or R ¹¹ and R ¹² may form a spiro ring,
A method for producing a polymerized toner, wherein X is one selected from the group consisting of CH ₂ , C═O, NR ¹⁵ , and O, and R ¹⁵ is a linear or branched alkyl group having 1 to 6 carbon atoms. It is.

  Furthermore, the method for producing a polymerized toner of the present invention is a method for producing a polymerized toner, wherein the polymerizable monomer capable of radical polymerization contains 50% by mass or more of a styrene monomer.

  Further, in the method for producing a polymerized toner according to the present invention, the polymerizable monomer capable of radical polymerization contains 60 to 95% by mass of a styrene monomer and 5 to 40% by mass of a (meth) acrylic acid derivative. This is a method for producing a polymerized toner.

  Furthermore, the method for producing a polymerized toner of the present invention is a method for producing a polymerized toner in which the polymer particles have a core-shell structure.

  Furthermore, the method for producing a polymerized toner of the present invention has a weight average molecular weight Mw of 5,000 to 30,000 of the polymer particles, and is represented by a ratio Mw / Mn between the weight average molecular weight Mw and the number average molecular weight Mn. In this method, the molecular weight distribution of the polymer particles is 1.60 or less.

  Furthermore, the method for producing a polymerized toner of the present invention is a method for producing a polymerized toner, wherein the polymerizable monomer composition contains a colorant or a release agent.

  According to the method for producing a polymerized toner of the present invention, it is possible to efficiently produce a polymerized toner with a high balance of low-temperature fixability, high-temperature hot offset property, printing durability, and weather resistance. In the heating roller fixing method used, the power used for heating the roller can be saved, so that it is possible to contribute to energy saving.

  The method for producing a polymerized toner of the present invention is represented by a polymerizable monomer capable of radical polymerization, a compound represented by formula (1), and a formula (2) in an aqueous medium containing a dispersion stabilizer or an emulsifier. A polymerization step of polymerizing a polymerizable monomer composition containing at least one compound selected from the group consisting of compounds to form polymer particles, and adding an external additive to the resulting polymer particles And a method for producing a polymerized toner including an external additive adding step.

(Here, R ^{1 to} R ³ are each independently one selected from the group consisting of a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a phenyl group,
R ⁴ and R ⁵ are each independently a C 3-12 linear or branched alkyl group which may have a substituent, and the substituent may have a substituent. It is one selected from the group consisting of a phenyl group, a dialkylphosphono group having 1 to 6 carbon atoms in the alkyl group, and a trialkylsilyl group having 1 to 6 carbon atoms in the alkyl group. )

(Here, R ^{6 to} R ⁸ are each independently one selected from the group consisting of a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a phenyl group,
R ^{9 to} R ¹² are each independently a linear or branched alkyl group having 2 to 12 carbon atoms which may have a substituent, and the substituent has a carbon number of a phenyl group or an alkyl group. 1 to 6 dialkylphosphono groups and one selected from the group consisting of trialkylsilyl groups having 1 to 6 carbon atoms in the alkyl group, R ⁹ and R ¹⁰ , or R ¹¹ and R ¹² are May form a spiro ring,
X is one selected from the group consisting of CR ¹³ R ¹⁴ , C═O, NR ¹⁵ , O and S, and each of R ^{13 to} R ¹⁵ independently represents a hydrogen atom, or a carbon number of 1 to 6 A linear or branched alkyl group, and a phenyl group. )

I. Polymerizable monomer composition The polymerizable monomer composition includes the following components.

1. Polymerizable monomer capable of radical polymerization The polymerizable monomer capable of radical polymerization is not particularly limited as long as it is a polymerizable monomer that can be polymerized using a radical polymerization initiator. A monomer is preferred. Specifically, styrene monomers such as styrene, vinyl toluene, α-methyl styrene; acrylic acid, methacrylic acid; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, Acrylic acid or methacrylic such as dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, dimethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide Acid derivatives (collectively referred to as “(meth) acrylic acid derivatives”); ethylenically unsaturated monoolefins such as ethylene, propylene, butylene; vinyl chloride, vinylidene chloride, vinyl fluoride Vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone and methyl isopropenyl ketone; 2-vinyl pyridine and 4-vinyl pyridine And nitrogen-containing vinyl compounds such as N-vinylpyrrolidone; Monovinyl monomers can be used alone or in combination of a plurality of monomers. Preferably, the polymerizable monomer contains 50% by mass or more of a styrene monomer. More preferably, the polymerizable monomer contains 60 to 95% by mass of a styrenic monomer and 40 to 5% by mass of a (meth) acrylic acid derivative, and particularly preferably a polymerizable monomer. As a styrene-type monomer, it contains 60-80 mass% and (meth) acrylic acid derivatives 40-20 mass%.

  Use of a crosslinkable monomer or a crosslinkable polymer together with the polymerizable monomer is effective in improving the high temperature hot offset property.

  The crosslinkable monomer is a monomer having two or more polymerizable carbon-carbon unsaturated double bonds, and examples thereof include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; Diethylenically unsaturated carboxylic acid esters such as methacrylate and diethylene glycol dimethacrylate; di (meth) acrylates derived from aliphatic terminal alcohols such as 1,4-butanediol and 1,9-nonanediol; N, N-divinylaniline; Divinyl compounds such as divinyl ether; compounds having 3 or more vinyl groups;

  Examples of the crosslinkable polymer include polyethylene, polypropylene, and polyester having two or more hydroxyl groups in the molecule, and polyfunctional (meth) acrylate derived from polysiloxane. These crosslinkable monomers and crosslinkable polymers can be used alone or in combination of two or more.

  In the crosslinkable monomer or the crosslinkable polymer, one or both of the crosslinkable monomer or the crosslinkable polymer is usually 10 parts by mass or less, preferably 0. It is used in a proportion of 01 to 5 parts by mass, more preferably 0.1 to 2 parts by mass.

  When a macromonomer is used together with a polymerizable monomer, the balance of low-temperature fixability, hot offset prevention property and printing durability can be improved. A macromonomer is a relatively long linear molecule having a polymerizable functional group (for example, an unsaturated group such as a carbon-carbon double bond) at the end of a molecular chain. As the macromonomer, an oligomer or polymer having a number average molecular weight of usually 1,000 to 30,000 is preferable. When a macromonomer having a small number average molecular weight is used, the surface portion of the polymer particles becomes soft and the storage stability as a toner is lowered. On the other hand, if a macromonomer having a large number average molecular weight is used, the meltability of the macromonomer is poor and the fixing property of the toner is lowered.

  Specific examples of the macromonomer include styrene, a styrene derivative, a methacrylic acid ester, an acrylic acid ester, acrylonitrile, a methacrylonitrile, a polymer obtained by polymerizing two or more kinds alone, and a macromonomer having a polysiloxane skeleton. Etc. When using a macromonomer, the blending ratio is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 100 parts by mass with respect to 100 parts by mass of the polymerizable monomer. 1 part by mass. When the proportion of the macromonomer used is too high, the fixability tends to decrease.

2. The compound represented by the formula (1) and the compound represented by the formula (2) The present invention comprises a polymerizable monomer capable of radical polymerization, a compound represented by the formula (1) and a compound represented by the formula (2). It includes a polymerization step of polymerizing a polymerizable monomer composition containing at least one compound selected from the group to form polymer particles.

(Here, R ^{1 to} R ³ are each independently one selected from the group consisting of a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a phenyl group,
R ⁴ and R ⁵ are each independently a C 3-12 linear or branched alkyl group which may have a substituent, and the substituent may have a substituent. It is one selected from the group consisting of a phenyl group, a dialkylphosphono group having 1 to 6 carbon atoms in the alkyl group, and a trialkylsilyl group having 1 to 6 carbon atoms in the alkyl group. )

(Here, R ^{6 to} R ⁸ are each independently one selected from the group consisting of a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a phenyl group,
R ^{9 to} R ¹² are each independently a linear or branched alkyl group having 2 to 12 carbon atoms which may have a substituent, and the substituent has a carbon number of a phenyl group or an alkyl group. 1 to 6 dialkylphosphono groups and one selected from the group consisting of trialkylsilyl groups having 1 to 6 carbon atoms in the alkyl group, R ⁹ and R ¹⁰ , or R ¹¹ and R ¹² are May form a spiro ring,
X is one selected from the group consisting of CR ¹³ R ¹⁴ , C═O, NR ¹⁵ , O and S, and each of R ^{13 to} R ¹⁵ independently represents a hydrogen atom, or a carbon number of 1 to 6 A linear or branched alkyl group, and a phenyl group. )

  Low temperature fixability by polymerizing the polymerizable monomer composition in the presence of at least one compound selected from the group consisting of the compound represented by the formula (1) and the compound represented by the formula (2); It is considered that the morphology of polymer particles is controlled because a polymer toner having a high balance between hot offset resistance and durability is obtained, but the detailed reason is not yet clear. In the method for producing a polymerized toner of the present invention, it is not necessary to use another ordinary radical polymerization initiator in order to carry out the polymerization reaction. Rather, when other ordinary radical polymerization initiator is used in combination, the polymerization reaction is inhibited. Therefore, it is understood that the compound represented by the formula (1) or the compound represented by the formula (2) functions as a polymerization initiator.

  In other words, the method for producing a polymerized toner of the present invention uses, for example, 2,2′-azobis (2-methyl-N- (2-hydroxyethyl) -propionamide) in a polymerization reaction for obtaining polymer particles. Even if a conventionally known radical polymerization initiator is not used, at least one compound selected from the group consisting of the compound represented by the formula (1) and the compound represented by the formula (2) exists. It is characterized in that the polymerization reaction of a polymerizable monomer capable of radical polymerization proceeds suitably. In particular, when a polymerizable monomer having lipophilicity occupies a dominant amount, specifically, when the polymerizable monomer capable of radical polymerization contains 50% by mass or more of a styrene monomer, As a more preferable aspect, when 60 to 95 mass% of styrene-type monomers and 5 to 40 mass% of (meth) acrylic acid derivatives are contained, the reaction proceeds more suitably.

  Such characteristics of the compound represented by the formula (1) or the compound represented by the formula (2) were found for the first time in the present invention, and are presumed to be derived from the chemical structure of these compounds. .

In the compound represented by the formula (1), R ^{1 to} R ³ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ⁴ and R ⁵ are each independently a substituent. A branched alkyl group having 3 to 7 carbon atoms which may have a phenyl group, a dialkylphosphono group having 1 to 6 carbon atoms in the alkyl group, and an alkyl group having 1 to 3 carbon atoms. The compound is preferably one selected from the group consisting of 6 trialkylsilyl groups. As the branched alkyl group having 3 to 7 carbon atoms which may have a substituent in R ⁴ and R ⁵ , a tert-butyl group and an isobutyl group are particularly preferable. Further, as the dialkylphosphono group having 1 to 6 carbon atoms in the alkyl group as a substituent in R ⁴ and R ⁵ , a diethylphosphono group is particularly preferable, and similarly, the carbon number of the alkyl group as a substituent is As the trialkylsilyl group of 1 to 6, a trimethylsilyl group is particularly preferable.

In the compound represented by the formula (2), R ^{6 to} R ⁸ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ^{9 to} R ¹² are each independently 2 carbon atoms. -4 linear or branched alkyl groups, wherein R ⁹ and R ¹⁰ , or R ¹¹ and R ¹² may form a spiro ring, and X is CH ₂ , C═O, NR ¹⁵ , and It is preferably one selected from the group consisting of O, and R ¹⁵ is preferably a linear or branched alkyl group having 1 to 6 carbon atoms.

  A particularly preferred compound is 2-methyl-2- [N- (tertiarybutyl) -N- (1-diethylphosphono-2,2-dimethylpropyl) aminoxy] propane as the compound represented by the formula (1). Acid, methyl 2- [N- (tertiarybutyl) -N- (1-diethylphosphono-2,2-dimethylpropyl) aminoxy] propanoate, 2,2,5-trimethyl-3-[(2-methyl -2-carboxylic acid) -ethoxy] -4-p-carboxyphenyl-3-azahexane and 2,2,5-trimethyl-3-[(2-methyl-2-ethoxycarbonyl) -ethoxy] -4-p -Methylbenzoate-3-azahexane and the like. As the compound represented by the formula (2), 2- [trans-2,6-bis (tertiarybutyldimethylsiloxymethyl) -2 , 6-Diethyl-1-piperidinoxy] -propanoic acid butyl ester and the like.

  The amount of the compound represented by the formula (1) or the compound represented by the formula (2) is 0.1 to 10 parts by mass with respect to 100 parts by mass of the radically polymerizable monomer, preferably It is 0.5-8 mass parts, More preferably, it is 1-7 mass parts, Most preferably, it is 2-6 mass parts. Any one of the compound represented by the formula (1) or the compound represented by the formula (2) may be used, and the compound represented by the formula (1) and the compound represented by the formula (2) When using together, what is necessary is just to adjust so that those total usage-amount may be contained in the previous range.

3. Polymerization accelerator In the method for producing a polymerized toner of the present invention, at least one selected from the group consisting of a polymerizable monomer capable of radical polymerization, a compound represented by formula (1), and a compound represented by formula (2) A polymerization accelerator can be added to the polymerizable monomer composition containing the compound. Specifically, camphorsulfonic acid, acetic anhydride, acetylacetone, trifluoroacetic anhydride, ethyl acetylacetate, diethyl malonate, biscyanomethane, chloroacetic acid, bromoacetic acid, trinitrophenol, N-benzoic acid succinimide, etc. Can be mentioned. By using these polymerization accelerators, the polymerization rate can be improved. The polymerization accelerator to be used causes homo-cleavage of the carbon-oxygen bond by electrostatic interaction with at least one compound selected from the group consisting of the compound represented by formula (1) and the compound represented by formula (2). It is understood to promote. The addition amount is not particularly limited, but is preferably 0.05 to 10 equivalents and more preferably 0.1 to 5 equivalents in terms of molar ratio to the compound represented by formula (1) or (2). . If the addition amount is too small, the polymerization promoting effect cannot be obtained, and if it is too large, the polymerization may be inhibited.

4). Colorant In the method for producing a polymerized toner of the present invention, it is preferable that a colorant is contained in the polymerizable monomer composition.

  As the colorant, various pigments and dyes used in the toner field such as carbon black and titanium white can be used, and any of the black colorant and the color toner colorant can be used.

  Examples of the black colorant include carbon black and nigrosine-based dyes and pigments; magnetic particles such as cobalt, nickel, iron tetroxide, manganese iron oxide, zinc iron oxide, and nickel iron oxide. When carbon black is used, it is preferable to use carbon black having a primary particle size of 20 to 40 nm because good image quality can be obtained and the safety of the toner to the environment is enhanced.

  As a color toner colorant, a yellow colorant, a magenta colorant, a cyan colorant, or the like can be used.

  Examples of the yellow colorant include C.I. I. Pigment Yellow 3, 12, 13, 14, 15, 17, 62, 65, 73, 83, 90, 93, 97, 120, 138, 155, 180, 181; Nephthol Yellow S, Hansa Yellow G, C.I. I. Examples thereof include bat yellow.

  Examples of the magenta colorant include azo pigments and condensed polycyclic pigments. More specifically, for example, C.I. I. Pigment Red 48, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 149, 163, 170, 184, 185, 187, 202, 206, 207, 209, 251; C.I. I. Pigment violet 19 and the like.

  Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and the like. I. Pigment blue 2, 3, 6, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 17, 60; phthalocyanine blue, C.I. I. Bat Blue, C.I. I. Acid blue and so on.

  These colorants are generally 0.1 to 50 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the polymerizable monomer that forms the binder resin or the binder resin. Used in Moreover, each coloring agent can be used individually or in combination of multiple things.

  Lubricants such as fatty acids such as oleic acid and stearic acid, and fatty acid metal salts composed of fatty acids and metals such as Na, K, Ca, Mg, Zn; silane-based, aluminum-based or titanium-based for uniform dispersion of the colorant A dispersion aid such as a coupling agent can be used. The lubricant and the dispersant are usually used in a ratio of about 1/1000 to 1/1 based on the mass of the colorant.

5. Release Agent In the method for producing a polymerized toner of the present invention, it is preferable that a release agent is contained in the polymerizable monomer composition.

  The release agent is not particularly limited as long as it is generally used as a release agent for toner. For example, polyolefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and low molecular weight polybutylene; candelilla, carnauba Natural wax such as paraffin, microcrystalline and petrolatum; mineral wax such as montan, ceresin and ozokerite; synthetic wax such as Fischer-Tropsch wax; pentaerythritol tetramyristate; Pentaerythritol esters such as pentaerythritol tetrapalmitate, pentaerythritol tetrastearate, and pentaerythritol tetralaurate, and dipentaerythritol hexami State, dipentaerythritol hexa palmitate, and polyhydric alcohol ester compounds such as dipentaerythritol esters such as dipentaerythritol hexa laurate; and the like.

  These release agents may be used alone or in combination of two or more. When these mold release agents are used, it is preferably used at a rate of 0.1 to 20 parts by mass, and at a rate of 1 to 15 parts by mass with respect to 100 parts by mass of the polymerizable monomer capable of radical polymerization. More preferably it is used.

6). Molecular weight regulator In the method for producing a polymerized toner of the present invention, a molecular weight regulator can be contained in the polymerizable monomer composition.

  Examples of the molecular weight modifier include mercaptans such as tert-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride and carbon tetrabromide; These molecular weight modifiers can be added before the polymerization starts or during the polymerization. The molecular weight modifier is preferably used in a proportion of 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymerizable monomer capable of radical polymerization.

7). Charge Control Agent In the method for producing a polymerized toner of the present invention, it is preferable to use various positively chargeable or negatively chargeable charge control agents in order to improve the chargeability of the toner.

  Examples of the charge control agent include Bontron N01 (manufactured by Orient Chemical Co., Ltd.), Nigrosine Base EX (manufactured by Orient Chemical Co., Ltd.), Spiro Black TRH (manufactured by Hodogaya Chemical Co., Ltd.), and T-77 (Hodogaya). Chemical Industries, Ltd.), Bontron S-34 (Orient Chemical Industries, Ltd.), Bontron E-81 (Orient Chemical Industries, Ltd.), Bontron E-84 (Orient Chemical Industries, Ltd.), Bontron E-89 (Orient Chemical Industries, Ltd.), Bontron F-21 (Orient Chemical Industries, Ltd.), COPY CHRGE NX VP434 (Clariant), COPY CHRGE NEG VP2036 (Clariant), TNS-4-1 (Hodogaya) Chemical Industry Co., Ltd.), TNS-4-2 (Hodogaya Chemical) Charge control agent such as LR-147 (manufactured by Nippon Carlit Co., Ltd.); grade 4 described in JP-A-11-15192, JP-A-3-175456, JP-A-3-243594, etc. Charging of ammonium (salt) group-containing copolymers, sulfonic acid (salt) group-containing copolymers described in JP-A-3-243955, JP-A-1-217464, JP-A-3-15858 and the like A control resin such as FCA626N (manufactured by Fujikura Kasei Co., Ltd.) can be used.

  The charge control agent is usually 0.01 to 10 parts by weight, preferably 0.1 to 7 parts by weight with respect to 100 parts by weight of the polymerizable monomer that forms the binder resin or the binder resin. Used in proportions.

8). Other Additives The polymerizable monomer composition may contain other additives that are usually blended in the production method of the polymerized toner.

  However, other so-called radical polymerization initiators may be used in combination in the polymerization step of the production method of the polymerized toner of the present invention, but it is preferable not to use them together. When a normal radical polymerization initiator is used in combination, efficient production of a polymerized toner with a high balance of low-temperature fixability, high-temperature hot offset property, printing durability, and weather resistance may be hindered.

II. 1. an aqueous medium containing a dispersion stabilizer or emulsifier Dispersion Stabilizer or Emulsifier The method for producing the polymerized toner of the present invention comprises a radically polymerizable polymerizable monomer, a compound represented by formula (1), and a formula, in an aqueous medium containing the dispersion stabilizer or emulsifier. A polymerization step of polymerizing a polymerizable monomer composition containing at least one compound selected from the group consisting of compounds represented by (2) to form polymer particles;

  A dispersion stabilizer is used in suspension polymerization. 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; water Metal hydroxides such as aluminum oxide, magnesium hydroxide, and ferric hydroxide; water-soluble polymers such as polyvinyl alcohol, methylcellulose, and gelatin; anionic surfactants, cationic surfactants And organic compounds such as surfactants such as surfactants, nonionic surfactants, and amphoteric surfactants. The said dispersion stabilizer can be used 1 type or in combination of 2 or more types. Among them, the dispersion stabilizer containing a metal compound, particularly a colloid of a poorly water-soluble metal hydroxide, can narrow the particle size distribution of the colored resin particles, and the residual amount of the dispersion stabilizer after washing is small. The obtained toner is preferable because an image can be clearly reproduced and environmental stability is not deteriorated.

  The emulsifier is used in emulsion polymerization. A surfactant is used as the emulsifier. Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; And nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols.

  The dispersion stabilizer or the emulsifier is preferably used in a proportion of 0.1 to 20 parts by mass, more preferably 0.3 to 10 parts by mass with respect to 100 parts by mass of the polymerizable monomer capable of radical polymerization. When this use ratio is too low, it becomes difficult to obtain sufficient polymerization stability, and polymerized aggregates are easily generated. On the other hand, when the use ratio is too high, the particle size distribution of the polymer particles is broadened due to the increase in fine particles, or the viscosity of the aqueous solution is increased, resulting in a decrease in polymerization stability.

2. Aqueous medium In the polymerization step of the method for producing a polymerized toner of the present invention, a radically polymerizable polymerizable monomer, a compound represented by the formula (1), and a formula in an aqueous medium containing a dispersion stabilizer or an emulsifier A polymerizable monomer composition containing at least one compound selected from the group consisting of compounds represented by (2) is polymerized to form polymer particles.

  The aqueous medium used in the method for producing a polymerized toner of the present invention may be water alone, but a solvent that is soluble in water such as lower alcohol and lower ketone may be used in combination. As water, it is preferable to use ultrapure water, ion-exchanged water, distilled water or the like.

III. Production method of polymerized toner Polymerization Reaction The method for producing a polymerized toner of the present invention comprises a polymerizable monomer capable of radical polymerization, a compound represented by formula (1), and a formula (2) in an aqueous medium containing a dispersion stabilizer or an emulsifier. And a polymerization step of polymerizing a polymerizable monomer composition containing at least one compound selected from the group consisting of compounds represented by formula (I) to form polymer particles. As the polymerization method, a suspension polymerization method or an emulsion polymerization method is usually employed.

  In the suspension polymerization method, first, a polymerizable monomer capable of radical polymerization, a compound represented by formula (1), and a compound represented by formula (2) in an aqueous dispersion medium containing a dispersion stabilizer. A polymerizable monomer composition containing at least one compound selected from the group consisting of the above is added to prepare an aqueous dispersion of the polymerizable monomer composition. Subsequently, the method of heating this, performing a polymerization reaction, and producing | generating a polymer particle is employable.

  In the emulsion polymerization method, first, a radically polymerizable polymerizable monomer, a compound represented by the formula (1), and a compound represented by the formula (2) are selected from the aqueous dispersion medium containing the emulsifier. The polymerizable monomer composition containing at least one kind of compound is added to prepare an emulsion of the polymerizable monomer composition, and this is heated to conduct a polymerization reaction, thereby emulsifying the polymer particles. After obtaining the dispersion, the pH is made alkaline with a base, and an alkali metal salt or alkaline earth metal salt is used as a flocculant or heated to a temperature higher than the glass transition point of the polymer particles. It is possible to adopt a method in which precipitation and aggregation are advanced to produce polymer particles.

  The polymerization temperature is usually 50 ° C. or higher, preferably 60 to 95 ° C. in both suspension polymerization method and emulsion polymerization method. The reaction time of the polymerization is usually 1 to 150 hours, preferably 5 to 100 hours. The aqueous dispersion containing the produced polymer particles is filtered, and then the polymer particles are recovered through the steps of washing, dehydration, and drying.

  The polymerizable monomer capable of radical polymerization used for forming the polymer particles has a glass transition temperature Tg of a polymer obtained by polymerizing it of usually 80 ° C. or lower, preferably 40 to 80 ° C., more preferably It is desirable to select so that it may become 50-70 degreeC. By using a polymerizable monomer capable of radical polymerization alone or in combination of two or more, the glass transition temperature of the polymer to be produced can be adjusted to a desired range.

  Moreover, in order not to reduce the activity of at least one compound selected from the group consisting of the compound represented by the formula (1) and the compound represented by the formula (2), the above-described polymerization reaction may be performed using nitrogen, helium or argon. It is preferably carried out in an inert gas atmosphere, and the oxygen concentration in the gas phase of the reactor is preferably 1000 ppm or less, more preferably 500 ppm or less, and even more preferably 100 ppm or less. When the oxygen concentration is higher than 1000 ppm, the molecular weight distribution of the obtained polymer particles becomes wide, and hot offset may easily occur. Furthermore, the radically polymerizable monomer or aqueous medium used for the polymerization is preferably bubbled with an inert gas such as nitrogen or argon so that the dissolved oxygen concentration is preferably 10 ppm or less, and 5 ppm or less. More preferred is 1 ppm or less.

2. Recovery of polymer particles An aqueous dispersion containing polymer particles produced by polymerization contains a dispersion stabilizer or an emulsifier. In particular, when a dispersion stabilizer is used, the polymer particles contain a large number of dispersion stabilizer fine particles. When an inorganic compound such as an inorganic hydroxide that is soluble in acid is used as the dispersion stabilizer, acid is added to the aqueous dispersion containing the produced polymer particles, and the dispersion stabilizer is added to water. Dissolve and remove. When the dispersion stabilizer is an alkali-soluble inorganic compound, alkali is added to the aqueous dispersion containing the produced polymer particles, and the dispersion stabilizer is dissolved in water and removed.

  For example, when a colloid of a poorly water-soluble metal hydroxide such as magnesium hydroxide colloid is used as the dispersion stabilizer, an acid such as sulfuric acid is added to the aqueous dispersion to solubilize the dispersion stabilizer in water. By washing with this acid, the pH of the aqueous dispersion is usually adjusted to 6.5 or less, preferably 2 to 6.5, more preferably 3 to 6.0. As the acid to be added, inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid; organic acids such as formic acid and acetic acid can be used.

  The aqueous dispersion obtained after washing with acid or alkali is filtered to separate the polymer particles. Next, the colored polymer particles separated by filtration are washed with water, and the washing water is filtered. In the water washing step, it is preferable to wash with water until the electrical conductivity of the filtrate (filtered washing water) becomes 1,000 μS / cm or less, and to filter the washing water. The water washing step may be repeated batchwise or continuously using a belt filter or the like. As a cleaning apparatus used for water cleaning, for example, it is preferable to use any one of a belt filter, a rotary filter, and a filter press, or a combination thereof. After the washing step, the wet polymer particles are dehydrated and dried by the dehydration step.

3. Production of Polymer Particles Having Core-Shell Structure According to the method for producing a polymerized toner of the present invention, micron-order polymer particles can be directly obtained with a relatively small particle size distribution in the polymerization step. However, the polymer particles for obtaining the polymerized toner of the present invention may be polymer particles having a core-shell structure in which a resin coating layer (polymer layer) is further formed on the surface of the core particles. -When polymer particles having a shell structure are used, a core-shell type toner (capsule toner) can be obtained.

  When polymer particles having a core-shell structure are produced, they can be produced by methods such as a spray drying method, an interfacial reaction method, an in situ polymerization method, and a phase separation method. In particular, the in situ polymerization method and the phase separation method are preferable because of high production efficiency. Specifically, a group comprising a polymerizable monomer capable of radical polymerization, a compound represented by formula (1), and a compound represented by formula (2) in an aqueous dispersion medium containing a dispersion stabilizer or an emulsifier. Resin particles obtained by subjecting a polymerizable monomer composition containing at least one compound selected from suspension polymerization or emulsion polymerization to core particles, and polymerization for shells in the presence of the core particles By subjecting the polymerizable monomer to suspension polymerization or emulsion polymerization in the presence of a polymerization initiator, the shell polymerizable monomer is polymerized to form a shell. In the course of the polymerization reaction of the shell polymerizable monomer for forming the shell, the core particle polymerization reaction may be continued.

  As a polymerization initiator for polymerizing the polymerizable monomer for shell, at least one compound selected from the group consisting of the compound represented by the formula (1) and the compound represented by the formula (2) of the present invention is used. However, a normal radical polymerization initiator can also be used.

  The average thickness of the shell in the polymer particles having a core-shell structure is usually 0.001 to 2 μm, preferably 0.003 to 1 μm, more preferably 0.005 to 0.5 μm, and particularly preferably 0.01 to 0. .3 μm (10-300 nm). If the shell thickness is too large, the fixability of the resulting polymerized toner will decrease, and if it is too small, the storage stability will decrease. If the core particle diameter and the shell thickness of the polymer particles can be observed with an electron microscope, they can be obtained by directly measuring the particle size and shell thickness randomly selected from the observation photograph. If it is difficult to distinguish and observe the core particle and the shell with an electron microscope, calculate the thickness of the shell from the volume average particle diameter of the core particle and the amount of polymerizable monomer used to form the shell. Can do.

  In the case of polymer particles having a core-shell structure, the glass transition temperature of the polymer constituting the shell is preferably higher than the glass transition temperature of the polymer constituting the core particle, more preferably 5 ° C or higher, It is particularly preferable that the temperature is 10 ° C. or higher. As the polymerizable monomer for the shell, styrene, methyl methacrylate, acrylonitrile, or a mixture thereof capable of forming a polymer having a high glass transition temperature exceeding 80 ° C. is preferable.

  Radical polymerization initiators used for polymerization of the polymerizable monomer for shell include persulfates such as potassium persulfate and ammonium persulfate; 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propion Amido], 2,2′-azobis- [2-methyl-N- [1,1-bis (hydroxymethyl) 2-hydroxyethyl] propionamide] and other azo-based initiators; And water-soluble azo initiators are preferred. The addition amount of the polymerization initiator is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer for shell. The polymerization temperature of the shell layer is preferably 50 ° C. or higher, more preferably 60 to 95 ° C. The polymerization reaction time is preferably 1 to 20 hours, more preferably 2 to 15 hours.

  In the case of producing a colored polymerized toner, a colorant is usually contained in the polymerizable monomer composition forming the core particles.

4). Physical Properties of Polymer Particles 1) Molecular Weight of Polymer Particles In the production method of the polymerized toner of the present invention, the weight average molecular weight Mw of the polymer particles obtained in the polymerization step is preferably 5,000 to 30,000, More preferably, it is 8,000 to 20,000, particularly preferably 10,000 to 16,000, and the molecular weight distribution of the polymer particles represented by the ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn. Is preferably 1.60 or less, more preferably 1.50 or less, and particularly preferably 1.40 or less. When the weight average molecular weight Mw of the polymer particles exceeds 30,000, the low-temperature fixability is inferior. On the other hand, when the Mw is less than 5,000, the heat resistance and durability of the obtained polymerized toner are lowered. Further, when the molecular weight distribution of the polymer particles exceeds 1.60, the heat resistance of the obtained polymerized toner may be lowered or discoloration may easily occur.

2) Particle size of polymer particles The volume average particle size (Dv) of the polymer particles (including polymer particles having a core-shell structure) obtained in the polymerization step in the present invention is usually 3 to 12 μm, preferably 5 to 5 μm. It is 11 micrometers, More preferably, it is 6-10 micrometers. The particle size distribution represented by the ratio (Dv / Dn) of the volume average particle size (Dv) to the number average particle size (Dn) of the polymer particles in the present invention is usually 1.5 or less, preferably 1.4. Below, more preferably 1.3 or less. If the volume average particle size of the polymer particles is too large, the resolution of the resulting polymerized toner tends to be lowered. When the particle size distribution of the polymer particles is large, the ratio of the large particle size increases, and the resolution of the obtained polymerized toner tends to decrease.

5. Addition of External Additive The polymer toner of the present invention is obtained through an external additive addition step of adding an external additive to polymer particles. The polymerized toner of the present invention can be used as a one-component developer.

  Examples of the external additive include inorganic particles and organic resin particles that act as a fluidizing agent and an abrasive. Examples of the inorganic particles include silicon dioxide (silica), aluminum oxide (alumina), titanium oxide, zinc oxide, tin oxide, barium titanate, and strontium titanate.

  As organic resin particles, methacrylic acid ester polymer particles, acrylic acid ester polymer particles, styrene-methacrylic acid ester copolymer particles, styrene-acrylic acid ester copolymer particles, a core is a methacrylic acid ester copolymer, and a shell And particles having a core-shell structure formed of a styrene polymer.

  Among these, inorganic oxide particles are preferable, and silicon dioxide (silica) is particularly preferable. The surface of the inorganic fine particles can be hydrophobized, and silicon dioxide particles that have been hydrophobized are particularly suitable. Two or more types of external additives may be used in combination. In the case of using a combination of external additives, a method of combining inorganic particles having different average particle sizes or a combination of inorganic particles and organic resin particles is preferable. . Although the quantity of an external additive is not specifically limited, It is 0.1-6 mass parts normally with respect to 100 mass parts of polymer particles. In order to attach the external additive to the polymer particles, the polymer particles and the external additive are usually placed in a mixer such as a Henschel mixer and stirred.

  The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. Parts and% are based on mass unless otherwise specified.

  At least one compound selected from the group consisting of the compound represented by formula (1) and the compound represented by formula (2) used in Examples was Macromolecules 2004, 37, 4453-4463, Macromolecules 2004, 40, 6067- Synthesized according to 6075, J. Am. Chem. Soc. 2003, 125, 16327-16333 and WO 04/014926.

  Moreover, the radically polymerizable monomer and ion-exchanged water used for the polymerization were subjected to nitrogen bubbling so that the dissolved oxygen concentration was 1 ppm or less.

  The compounds used as polymerization initiators in Examples and Comparative Examples are shown in Table 1.

  A method for measuring physical properties and characteristics of the polymerized toner produced in the present invention is as follows.

(1) Number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn)
The number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) of the polymer particles were determined in terms of polystyrene by gel permeation chromatography. Specifically, the following method was used.

1) Sample preparation Approximately 10 mg of polymer particles were dissolved in 5 ml of tetrahydrofuran solvent, allowed to stand at 25 ° C. for 16 hours, and then passed through a 0.45 μm membrane filter as a sample.

2) Measurement conditions Temperature: 35 ° C., solvent: tetrahydrofuran, flow rate: 1.0 ml / min, concentration: 0.2 wt%, sample injection amount: 100 μl.

3) Column Tosoh Corporation make and GPC TSKgel MultiporeHXL-M (30 cm x 2 pieces) were used. The molecular weight Mw was measured under the condition that the primary correlation of Log (Mw) -elution time between 1,000 and 300,000 was 0.98 or more.

(2) Volume average particle size (Dv), number average particle size (Dn), and particle size distribution (Dv / Dn)
About 0.1 g of a measurement sample (polymer particles) was weighed and taken in a beaker, and 0.1 ml of an alkylbenzenesulfonic acid aqueous solution (manufactured by Fuji Film Co., Ltd., trade name: Drywell) was added as a dispersant. Add 10-30 mL of Isoton II to the beaker and disperse with a 20 W ultrasonic disperser for 3 minutes. Then, use a particle size analyzer (trade name: Multisizer, manufactured by Beckman Coulter, Inc.) to determine the aperture diameter. The volume average particle diameter (Dv) and the number average particle diameter (Dn) of the polymer particles were measured under the conditions of 100 μm, medium; Isoton II, the number of measured particles; 100,000 particles, and the particle size distribution (Dv / Dn) was calculated.

  Since the amount of the external additive added to the polymer particles is small, the particle size (volume average particle size (dv) and number average particle size (dn)) of the polymerized toner is measured instead of the particle size of the polymer particles. Thus, it can be regarded as the particle size of the polymer particles.

(3) Minimum fixing temperature and hot offset generation temperature A commercially available non-magnetic one-component development type printer (24-sheet machine (printing speed: A4 size 24 sheets / min)) can change the temperature of the fixing roll section. The toner was modified to change the temperature of the fixing roll, and the fixing rate of the toner at each temperature was measured in increments of 5 ° C., and a fixing test was performed to obtain the relationship between the temperature and the fixing rate.

When the temperature of the fixing roll is stabilized, solid fixing is performed on the printing paper using the above-described modified printer, and the black solid (printing density 100%) of the printed paper is printed before and after the tape peeling operation. Calculated from the ratio of print density. That is, the fixing ratio was calculated from the following equation, where the image density before tape peeling was ID (front) and the image density after tape peeling was ID (back).
Fixing rate (%) = (ID (back) / ID (front)) × 100

  Here, the tape peeling operation means that an adhesive tape (manufactured by Sumitomo 3M Co., Ltd., Scotch (registered trademark) mending tape 810-3-18) is applied to the measurement part of the test paper, and pressed and adhered at a constant pressure. Then, it is a series of operations for peeling the adhesive tape in a direction along the paper at a constant speed. In this fixing test, the lowest temperature among the temperatures of the fixing roll at which the fixing rate becomes 90% or more was set as the minimum fixing temperature of the toner. The minimum fixing temperature of the polymerized toner is preferably 160 ° C. or lower for handling.

  Next, the temperature was further increased, and the temperature until hot offset occurred was measured.

  A hot offset test was performed using a modified printer similar to the measurement of the minimum fixing temperature. In the hot offset test, the temperature of the fixing roll section is changed from 150 ° C. to 220 ° C. in 5 ° C., and a print pattern having a black solid (print density 100%) and white solid (print density 0%) print area is obtained. When printing, at each temperature, the presence or absence of print stains in the solid white print area (print density 0%) or the occurrence of toner fusing (hot offset phenomenon) on the fixing roll is visually observed. Observed.

  In this hot offset test, the lowest set temperature at which printing contamination or toner fusing occurred on the fixing roll was taken as the hot offset temperature. The hot offset temperature of the polymerized toner is preferably 205 ° C. or higher from the viewpoint of heat resistance.

  If no hot offset phenomenon occurs even when the temperature of the fixing roll is 220 ° C., the hot offset temperature is expressed as “220 <”.

(4) Durability printing test (N / N environment, H / H environment)
For the durability printing test, a commercially available non-magnetic one-component development type printer [negatively charged organic photoconductor developing drum, 24-sheet machine (printing speed = 24 sheets / min)] was used. After filling, printing paper was set.

  After standing for 24 hours in a normal temperature and normal humidity (N / N) environment (temperature: 23 ° C, humidity: 50%), continuous printing is performed up to 10,000 sheets at a 5% print density in the same environment. I did it.

  Black solid printing (printing density 100%) was performed every 500 sheets, and the printing density of the black solid image was measured using a reflection type image densitometer (product name: RD918, manufactured by Gretag Macbeth). After that, white solid printing (printing density 0%) is performed, the printer is stopped in the middle of white solid printing, and the toner in the non-image area on the developed photosensitive member is adhesive tape (manufactured by Sumitomo 3M Ltd., product) Name: Scotch mending tape 810-3-18), and then peeled off and affixed to printing paper.

  Next, the whiteness (B) of the printing paper on which the adhesive tape is affixed is measured with a whiteness meter (manufactured by Nippon Denshoku Co., Ltd., model name: NDW-1D). The whiteness (A) was measured and the whiteness difference (B−A) was defined as the fog value ΔE. Smaller values indicate better fogging. The number of continuously printed sheets capable of maintaining an image quality with a print density of 1.3 or more and a fog value ΔE of 0.7 or less was examined.

  The same durable printing test was also performed in a high temperature and high humidity (H / H) environment (temperature: 35 ° C., humidity: 80%).

  In addition, even at the time of 10,000 sheets, when the print density is 1.3 or more and the image quality with the fog value ΔE is 0.7 or less can be maintained, “10,000 <” is described.

  The durability required for practical use is 10,000 <under a normal temperature and normal humidity (N / N) environment, and is 8,500 or more under a high temperature and high humidity (H / H) environment.

(5) Discoloration test For the discoloration test, a printer similar to that described above was used so that the temperature of the fixing roll portion could be changed, and M / A (toner loading amount on the printing paper) 0.3-0. Adjustment was made to be in the range of 45 mg / cm ² , solid (print density 100%) was printed, and fixing was performed at 180 ° C.

  To reproduce the outdoor exposure test in the accelerated state, the solid print sample was exposed for 120 minutes at a black panel temperature of about 63 ° C. and a humidity of 75% according to ASTM G 26-Type B Method A using a water-cooled xenon arc apparatus. .

L * a * b * table using photochromimeter (Nippon Denshoku Co., Ltd., trade name: SE-2000) with chromaticity coordinates before and after exposure in reflection mode in solid (print density 100%) print area. The chromaticity coordinates in the color system were measured. From the measured value, the color difference value ΔE * before and after exposure was obtained by the following equation.
ΔE * = √ ((ΔL *) ² + (Δa *) ² + (Δb *) ² )

[Example 1]
77 parts of styrene, 23 parts of n-butyl acrylate, C.I. I. 5 parts of Pigment Yellow (PY74) and a charge control resin as a charge control agent (manufactured by Fujikura Kasei Co., Ltd., trade name “FCA626N (7% sulfonic acid group-containing monomer content); weight average molecular weight 26,800, 1 part of glass transition temperature 58 ° C.) and 10 parts of dipentaerythritol hexamyristate were dispersed with a bead mill at room temperature to obtain a uniform mixed solution. Thereafter, 3.8 parts of initiator (1) and 1.0 part of acetylacetone were added to obtain a polymerizable monomer composition for core.

  On the other hand, in an aqueous solution in which 9.8 parts of magnesium chloride (water-soluble polyvalent metal salt) was dissolved in 250 parts of ion-exchanged water, an aqueous solution in which 6.9 parts of sodium hydroxide was dissolved in 50 parts of ion-exchanged water was stirred. Gradually added to prepare a magnesium hydroxide colloidal dispersion. The above-described monomer composition is charged into the magnesium hydroxide colloidal dispersion obtained as described above, and stirred and mixed using a propeller-type stirrer. It is supplied to a granulator operating at 21,000 rpm (manufactured by MTechnic Co., Ltd., model name “CLEARMIX CLM-0.8S”) using a pump to form droplets of a monomer composition for toner. Grained. The granulated composition aqueous dispersion was transferred to a reactor equipped with a stirring blade, and then the inside of the reactor was degassed and purged with nitrogen.

  The composition aqueous dispersion was heated under a nitrogen stream to initiate polymerization. At this time, the polymerization reactor jacket temperature and the polymerization reaction solution internal temperature were measured so that the aqueous dispersion temperature was constant at 90 ° C., and the jacket temperature was controlled by using a cascade control method or the like. At this time, the oxygen concentration in the gas phase in the reactor was 50 ppm.

  A water-soluble polymerization initiator dissolved in 1 part of methyl methacrylate and 10 parts of ion-exchanged water as a polymerizable monomer for the shell after confirming that the polymerization conversion is 95% or more after polymerization at 90 ° C. for 12 hours. 2,2′-azobis (2-methyl-N- (2-hydroxyethyl) -propionamide) (trade name: VA-086, water-soluble) manufactured by Wako Pure Chemical Industries, Ltd. is added. did. Further, the temperature was maintained at 90 ° C. for 3 hours, and after confirming that the polymerization conversion reached almost 100%, the aqueous dispersion was cooled to stop the polymerization, and an aqueous dispersion of polymer particles was obtained. . The polymerization time was 15 hours in total. The polymer particles were dehydrated, washed and dried to obtain polymer particles. When the molecular weight of the obtained polymer particles was measured, the number average molecular weight was 11,500, the weight average molecular weight was 13,000, and the molecular weight distribution (Mw / Mn) was 1.13.

  To 100 parts of the polymer particles thus obtained, 0.6 part of hydrophobized fumed silica (trade name “RX-300” manufactured by Nippon Aerosil Co., Ltd.) is added, and a Henschel mixer is used. A polymerized toner was produced by mixing.

  Then, the peripheral speed of the rotary blade of the high-speed stirrer (Mitsui Mining Co., Ltd. Henschel mixer) was set to 30 m / sec and mixed for 25 minutes. Thereafter, coarse particles were removed using a sieve having an opening of 45 μm to prepare a polymerized toner.

  The volume average particle diameter (dv) of the polymerized toner was 7.3 μm, and the volume average particle diameter (dv) / number average particle diameter (dn) was 1.22. Table 2 shows the results of the above evaluation on the obtained toner.

[Example 2]
In Example 1, polymer particles were produced in the same manner as in Example 1 except that 3.8 parts of initiator (1) was changed to 3.8 parts of initiator (2). When the molecular weight of the obtained polymer particles was measured, the number average molecular weight was 11,300, the weight average molecular weight was 13,900, and the molecular weight distribution (Mw / Mn) was 1.23. The volume average particle diameter (dv) of the toner is 7.0 μm, and the volume average particle diameter (dv) / number average particle diameter (dn) is 1.25. Table 2 shows the results of the above evaluation on the obtained toner.

[Example 3]
In Example 1, polymer particles were produced in the same manner as in Example 1 except that 3.8 parts of initiator (1) was changed to 3.5 parts of initiator (3). When the molecular weight of the obtained polymer particles was measured, the number average molecular weight was 11,600, the weight average molecular weight was 14,500, and the molecular weight distribution (Mw / Mn) was 1.25. The volume average particle diameter (dv) of the toner is 7.7 μm, and the volume average particle diameter (dv) / number average particle diameter (dn) is 1.26. Table 2 shows the results of the above evaluation on the obtained toner.

[Example 4]
In Example 1, polymer particles were produced in the same manner as in Example 1 except that 3.8 parts of initiator (1) was changed to 3.9 parts of initiator (4). When the molecular weight of the obtained polymer particles was measured, the number average molecular weight was 11,200, the weight average molecular weight was 13,600, and the molecular weight distribution (Mw / Mn) was 1.21. The volume average particle diameter (dv) of the toner is 7.3 μm, and the volume average particle diameter (dv) / number average particle diameter (dn) is 1.22. Table 2 shows the results of the above evaluation on the obtained toner.

[Example 5]
In Example 1, 3.8 parts of initiator (1) was changed to 5.7 parts of initiator (5), and the polymer was the same as in Example 1 except that the reaction time was changed from 15 hours to 96 hours. Particles were produced. When the molecular weight of the obtained polymer particles was measured, the number average molecular weight was 10,800, the weight average molecular weight was 12,500, and the molecular weight distribution (Mw / Mn) was 1.16. The volume average particle diameter (dv) of the toner is 7.5 μm, and the volume average particle diameter (dv) / number average particle diameter (dn) is 1.22. Table 2 shows the results of the above evaluation on the obtained toner.

[Example 6]
In Example 1, after the granulated composition dispersion was transferred to the reactor, the inside of the reactor was depressurized and degassed, and polymerization was started without flowing nitrogen, and the reaction time was 15 hours to 96 hours. The polymer particles were produced in the same manner as in Example 1 except that the change was made. When the molecular weight of the obtained polymer particles was measured, the number average molecular weight was 10,000, the weight average molecular weight was 15,000, and the molecular weight distribution (Mw / Mn) was 1.50. The volume average particle diameter (dv) of the toner is 7.4 μm, and the volume average particle diameter (dv) / number average particle diameter (dn) is 1.23. Table 2 shows the results of the above evaluation on the obtained toner.

[Comparative Example 1]
In Example 1, the polymer was the same as in Example 1 except that 3.8 parts of initiator (1) was changed to 7.0 parts of initiator (6) and the reaction time was changed from 15 hours to 96 hours. Particles were produced. When the molecular weight of the obtained polymer particles was measured, the number average molecular weight was 7,500, the weight average molecular weight was 14,500, and the molecular weight distribution (Mw / Mn) was 1.93. The volume average particle diameter of the toner is 6.9 μm, and the volume average particle diameter (dv) / number average particle diameter (dn) is 1.27. Table 2 shows the results of the above evaluation on the obtained toner.

[Comparative Example 2]
In Example 1, 3.8 parts of initiator (1) was changed to 2.6 parts of initiator (7) (TEMPO) which is a well-known initiator, and the reaction time was changed from 15 hours to 96 hours. In the same manner as in Example 1, polymer particles were produced. When the molecular weight of the obtained polymer particles was measured, the number average molecular weight was 1,500, the weight average molecular weight was 1,950, and the molecular weight distribution (Mw / Mn) was 1.3. 20%. An attempt was made to evaluate the polymer particles as a toner, but the toner could not be obtained.

  The results of Examples and Comparative Examples are shown in Table 2.

  From the results of Examples 1 to 6, the polymerized toner of the present invention in which at least one compound selected from the group consisting of the compound represented by formula (1) and the compound represented by formula (2) is subjected to a polymerization reaction as a polymerization initiator is used. The polymerized toner obtained by the production method has a sufficiently low minimum fixing temperature (160 ° C. or lower), a sufficiently high hot offset generation temperature (205 ° C. or higher), and excellent durability printing test results in an H / H environment (8500 sheets). In addition, in the discoloration test reproducing the outdoor exposure test, it can be seen that the color difference value ΔE * before and after the exposure is small and the weather resistance is excellent.

  On the other hand, in Comparative Example 1 in which a compound different from the specific compound represented by formula (1) or formula (2) used in the present invention is used as a polymerization initiator, the minimum fixing temperature is 160 ° C., Although the endurance printing test result in the H / H environment is 8500 sheets, the hot offset generation temperature is 200 ° C. and the heat resistance is slightly inferior, and in the color change test reproducing the outdoor exposure test, the color difference value ΔE before and after exposure * Was 0.4, and only those having practical problems were obtained.

  In Comparative Example 2 using 2,2,6,6-tetramethyl-1-piperidinyloxy radical (TEMPO), which is a well-known living radical polymerization initiator, the polymerization conversion rate is 20%. The weight average molecular weight and the number average molecular weight did not reach 2000, and a toner could not be obtained.

  As shown in Table 2, the method for producing a polymerized toner of the present invention was able to efficiently produce a polymerized toner having a high balance of low-temperature fixability, high-temperature hot offset property, printing durability, and weather resistance. I understand.

  According to the method for producing a polymerized toner of the present invention, it is possible to efficiently produce a polymerized toner having a high balance between low-temperature fixability, high-temperature hot offset property, printing durability, and weather resistance.

Claims (9)

In an aqueous medium containing a dispersion stabilizer or an emulsifier, at least one selected from the group consisting of a polymerizable monomer capable of radical polymerization, a compound represented by formula (1), and a compound represented by formula (2) Polymerized toner comprising a polymerization step of polymerizing a polymerizable monomer composition containing the above compound to form polymer particles, and an external additive addition step of adding an external additive to the obtained polymer particles Manufacturing method.

(Here, R ^{1 to} R ³ are each independently one selected from the group consisting of a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a phenyl group,
R ⁴ and R ⁵ are each independently a C 3-12 linear or branched alkyl group which may have a substituent, and the substituent may have a substituent. It is one selected from the group consisting of a phenyl group, a dialkylphosphono group having 1 to 6 carbon atoms in the alkyl group, and a trialkylsilyl group having 1 to 6 carbon atoms in the alkyl group. )

(Here, R ^{6 to} R ⁸ are each independently one selected from the group consisting of a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and a phenyl group,
R ^{9 to} R ¹² are each independently a linear or branched alkyl group having 2 to 12 carbon atoms which may have a substituent, and the substituent has a carbon number of a phenyl group or an alkyl group. 1 to 6 dialkylphosphono groups and one selected from the group consisting of trialkylsilyl groups having 1 to 6 carbon atoms in the alkyl group, R ⁹ and R ¹⁰ , or R ¹¹ and R ¹² are May form a spiro ring,
X is one selected from the group consisting of CR ¹³ R ¹⁴ , C═O, NR ¹⁵ , O and S, and each of R ^{13 to} R ¹⁵ independently represents a hydrogen atom, or a carbon number of 1 to 6 A linear or branched alkyl group, and a phenyl group. ) In equation (1),
R ^{1 to} R ³ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,
R ⁴ and R ⁵ are each independently a branched alkyl group having 3 to 7 carbon atoms which may have a substituent, and the substituent is a phenyl group or an alkyl group having 1 to 6 carbon atoms. The dialkylphosphono group and the alkyl group are selected from the group consisting of trialkylsilyl groups having 1 to 6 carbon atoms,
The method for producing a polymerized toner according to claim 1. In equation (2),
R ^{6 to} R ⁸ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
R ^{9 to} R ¹² are each independently a linear or branched alkyl group having 2 to 4 carbon atoms, and R ⁹ and R ¹⁰ , or R ¹¹ and R ¹² may form a spiro ring,
X is one selected from the group consisting of CH ₂ , C═O, NR ¹⁵ , and O, and R ¹⁵ is a linear or branched alkyl group having 1 to 6 carbon atoms,
The method for producing a polymerized toner according to claim 1. The polymerizable monomer capable of radical polymerization contains 50% by mass or more of a styrene monomer.
The method for producing a polymerized toner according to any one of claims 1 to 3. The polymerizable monomer capable of radical polymerization contains 60 to 95% by mass of a styrene monomer and 5 to 40% by mass of a (meth) acrylic acid derivative.
The method for producing a polymerized toner according to claim 4. The polymer particles have a core-shell structure;
The method for producing a polymerized toner according to claim 1. The weight average molecular weight Mw of the polymer particles is 5,000 to 30,000, and the molecular weight distribution of the polymer particles represented by the ratio Mw / Mn between the weight average molecular weight Mw and the number average molecular weight Mn is 1.60 or less. is there,
The method for producing a polymerized toner according to claim 1.   The method for producing a polymerized toner according to claim 1, wherein a colorant is contained in the polymerizable monomer composition.   The method for producing a polymerized toner according to any one of claims 1 to 8, wherein a release agent is contained in the polymerizable monomer composition.