JP6950906B2 - Manufacturing method of toner for electrophotographic - Google Patents

Description

The present invention relates to a method for producing an electrophotographic toner.

In recent years, with the increase in speed and energy saving of printers and copiers, there is an increasing need for toner that can meet these demands.
In Patent Document 1, in a toner whose low-temperature fixing performance is improved by adding a crystalline resin, the toner particles have sufficient low-temperature fixing performance and have excellent fluidity in order to cope with a high-speed development process. The manufacturing method of is described. The document describes a method for producing toner particles containing a binder resin containing a styrene acrylic resin as a main component, a colorant, and a crystalline resin. After producing the resin particles by a specific method, the resin particles are used. A method for producing toner particles, which comprises a step of heating and holding the binder resin at a temperature equal to or higher than the intermediate glass transition temperature of the binder resin and lower than the melting start temperature of the crystalline resin for 0.5 hours or longer in an aqueous medium. Is described.

Japanese Unexamined Patent Publication No. 2013-80112

However, in the electrophotographic toner described in Patent Document 1, the dispersibility of the colorant becomes insufficient at the time of polymerization, and the color-developing property of the toner tends to decrease.
Therefore, the present invention relates to a method for producing an electrophotographic toner that exhibits excellent color development.

〔式中、Ｒ¹は、水素原子、炭素数１以上５以下のアルキル基、又は炭素数１以上５以下のヒドロキシアルキル基を示し、Ｒ²は、水素原子、炭素数１以上６以下のアルキル基、又は炭素数１以上５以下のヒドロキシアルキル基を示し、Ｒ³及びＲ⁴は、炭素数１以上５以下のアルカンジイル基を示す。Ｒ³及びＲ⁴は、同一でも異なっていてもよい。〕 By using a specific polyhydroxyamine compound in the step of obtaining a suspension, the present inventors can enhance the dispersibility of the colorant in the emulsified droplets, so that the toner for electrophotographic photography has excellent color-developing property. Was found to be obtained.
The present invention comprises a step of obtaining a suspension containing a polymerizable monomer, a polyhydroxyamine compound represented by the following formula (1), a colorant and a polymerization initiator in an aqueous medium.
The present invention relates to a method for producing an electrophotographic toner, which comprises a step of polymerizing a polymerizable monomer in the suspension.

[In the formula, R ¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a hydroxyalkyl group having 1 to 5 ^{carbon atoms, and R 2} is a hydrogen atom, an alkyl having 1 to 6 carbon atoms. It represents a group or a hydroxyalkyl group having 1 or more and 5 or less carbon atoms, and R ^{3 and R 4} represent an alcandiyl group having 1 or more and 5 or less carbon atoms. R ³ and R ⁴ may be the same or different. ]

According to the present invention, it is possible to provide a method for producing an electrophotographic toner exhibiting excellent color development.
In addition, according to the present invention, it is possible to provide a manufacturing method for obtaining an electrophotographic toner having a suppressed odor.

〔式中、Ｒ¹は、水素原子、炭素数１以上５以下のアルキル基、又は炭素数１以上５以下のヒドロキシアルキル基を示し、Ｒ²は、水素原子、炭素数１以上６以下のアルキル基、又は炭素数１以上５以下のヒドロキシアルキル基を示し、Ｒ³及びＲ⁴は、炭素数１以上５以下のアルカンジイル基を示す。Ｒ³及びＲ⁴は、同一でも異なっていてもよい。〕
上記の製造方法によれば、優れた発色性を示すトナーが得られる。 [Manufacturing method of toner for electrophotographic]
The method for producing an electrophotographic toner of the present invention (hereinafter, also simply referred to as "toner") is
A suspension containing a polymerizable monomer, a polyhydroxyamine compound represented by the following formula (1) (hereinafter, also simply referred to as “polyhydroxyamine compound”), a colorant, and a polymerization initiator in an aqueous medium. The process of obtaining (hereinafter, also referred to as "process 1") and
The suspension includes a step of polymerizing a polymerizable monomer (hereinafter, also referred to as “step 2”).

[In the formula, R ¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a hydroxyalkyl group having 1 to 5 ^{carbon atoms, and R 2} is a hydrogen atom, an alkyl having 1 to 6 carbon atoms. It represents a group or a hydroxyalkyl group having 1 or more and 5 or less carbon atoms, and R ^{3 and R 4} represent an alcandiyl group having 1 or more and 5 or less carbon atoms. R ³ and R ⁴ may be the same or different. ]
According to the above manufacturing method, a toner exhibiting excellent color development property can be obtained.

The reason why such an effect is obtained is not clear, but it is considered as follows.
Toner particles are obtained by polymerizing the polymerizable monomer in the suspension. At this time, if the dispersibility of the colorant in the polymerizable monomer is impaired, excellent color development cannot be obtained due to the aggregation of the colorant. On the other hand, the polyhydroxyamine compound has an excellent affinity with a colorant in the polymerizable monomer. Further, the polyhydroxyamine compound has excellent solubility in a polymerizable monomer. Since the polyhydroxyamine compound showed an effect as a dispersant for the colorant, a part of the polyhydroxyamine compound was partially polymerized during the polymerization of the polymerization monomer, and the polyhydroxyamine-polymerizable polymer composite was formed. It is considered that the formation of the body suppressed the reaggregation of the colorant and improved the color development property of the toner.

<Step 1>
In step 1, a suspension containing a polymerizable monomer, a polyhydroxyamine compound, a colorant and a polymerization initiator is obtained in an aqueous medium.
The suspension is, for example, a polyester resin, a charge control agent, a mold release agent, a magnetic powder, a fluidity improver, a conductivity adjusting agent, a reinforcing filler such as a fibrous substance, an antioxidant, an antiaging agent, and a cleaning property. It may contain an improver.

[Aqueous medium]
As the water-based medium, those containing water as a main component are preferable.
The content of water in the aqueous medium is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and 100% by mass or less. Yes, and even more preferably 100% by mass. As the water, deionized water or distilled water is preferable.
Examples of components other than water that can be contained in the aqueous medium include alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone; and soluble in water such as cyclic ethers such as tetrahydrofuran. Examples include organic solvents.

[Polymerizable monomer]
The polymerizable monomer is preferably a polymerizable monomer having an unsaturated double bond.
The suspension preferably contains, for example, a styrene compound and a (meth) acrylic acid ester as the polymerizable monomer.

Examples of the styrene compound include unsubstituted or substituted styrene. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group or a salt thereof and the like.
Examples of the styrene compound include styrenes such as styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid or a salt thereof. .. Of these, styrene is preferable.
The amount of the styrene compound is preferably 50% by mass or more, more preferably 65% by mass or more, still more preferably 70% by mass or more, and more preferably 70% by mass or more in the polymerizable monomer from the viewpoint of further improving the color development property of the toner. It is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less.

The (meth) acrylic acid ester is preferably a (meth) acrylic acid ester having an aliphatic hydrocarbon group.
The aliphatic hydrocarbon group of the (meth) acrylic acid ester having an aliphatic hydrocarbon group preferably has 1 or more carbon atoms, more preferably 2 or more, still more preferably 3 or more, still more preferably 4 or more, and It is preferably 22 or less, more preferably 18 or less, still more preferably 12 or less, still more preferably 8 or less, still more preferably 6 or less.

Examples of the aliphatic hydrocarbon group include an alkyl group, an alkenyl group and an alkynyl group. Among these, an alkyl group and an alkenyl group are preferable, and an alkyl group is more preferable. The aliphatic hydrocarbon group may be either branched or linear.
Examples of the (meth) acrylic acid ester include (meth) acrylic acid (iso) propyl, (meth) acrylic acid (iso) butyl, (meth) acrylic acid (iso) hexyl, (meth) acrylic acid cyclohexyl, and (meth) acrylic acid ester. ) Acrylic acid (iso) octyl, (meth) acrylic acid (iso) decyl, (meth) acrylic acid (iso) dodecyl, (meth) acrylic acid (iso) palmityl, (meth) acrylic acid (iso) stearyl, (meth) ) Acrylic acid (iso) behenyl can be mentioned. Among these, butyl (meth) acrylate is preferable.
Here, "(meth) acrylic acid" means acrylic acid or methacrylic acid. Further, with respect to the alkyl moiety, "(iso)" means normal alkyl or isoalkyl.

The amount of the (meth) acrylic acid alkyl ester is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and preferably 50% by mass or more in the polymerizable monomer. Hereinafter, it is more preferably 45% by mass or less, still more preferably 30% by mass or less.

Examples of other raw material monomers include ethylenically unsaturated monoolefins such as ethylene and propylene; conjugated dienes such as butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; (meth). ) (Meta) acrylic acid aminoalkyl esters such as dimethylaminoethyl acrylate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinylpyrrolidone.

The total amount of the styrene compound and the (meth) acrylic acid ester in the polymerizable monomer is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and 100. It is not more than mass%, preferably 100% by mass.

〔式中、Ｒ¹は、水素原子、炭素数１以上５以下のアルキル基、又は炭素数１以上５以下のヒドロキシアルキル基を示し、Ｒ²は、水素原子、炭素数１以上６以下のアルキル基、又は炭素数１以上５以下のヒドロキシアルキル基を示し、Ｒ³及びＲ⁴は、炭素数1以上5以下のアルカンジイル基を示す。Ｒ³及びＲ⁴は、同一でも異なっていてもよい。〕 [Polyhydroxyamine compound]
The polyhydroxyamine compound is a compound represented by the following formula (1) from the viewpoint of obtaining a toner exhibiting excellent color development.

[In the formula, R ¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a hydroxyalkyl group having 1 to 5 ^{carbon atoms, and R 2} is a hydrogen atom, an alkyl having 1 to 6 carbon atoms. It represents a group or a hydroxyalkyl group having 1 or more and 5 or less carbon atoms, and R ^{3 and R 4} represent an alcandiyl group having 1 or more and 5 or less carbon atoms. R ³ and R ⁴ may be the same or different. ]

The alkyl group of R ¹ preferably has 4 or less carbon atoms, more preferably 3 or less carbon atoms, still more preferably 2 or less carbon atoms, and even more preferably 1.
The alkyl group of R ¹ may be either a linear group or a branched chain, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, and various pentyl groups, and methyl is preferable. It is at least one selected from a group and an ethyl group, and more preferably a methyl group.

The ^{number of carbon atoms of the hydroxyalkyl group of R 1} is preferably 4 or less, more preferably 3 or less, still more preferably 2 or less, still more preferably 1 from the viewpoint of further improving the color development property of the toner.
Examples of the hydroxyalkyl group of R ¹ include a hydroxymethyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, and a 4-hydroxybutyl group. , And preferably at least one selected from a hydroxymethyl group and a 2-hydroxyethyl group, and more preferably a hydroxymethyl group.

Among these, R ¹ is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyalkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom, a methyl group, an ethyl group, and the like. At least one selected from a hydroxymethyl group and a hydroxyethyl group, more preferably a hydrogen atom, and at least one selected from a hydroxymethyl group, still more preferably a hydroxymethyl group.

The alkyl group of R ² preferably has 3 or less carbon atoms, more preferably 2 or less carbon atoms, and preferably 1 or more carbon atoms.
The alkyl group of R ² may be linear, branched or cyclic, and may be, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, or various hexyl groups. Examples include a group, a cyclopentyl group, and a cyclohexyl group.
The hydroxyalkyl group of R ² preferably has 3 or less carbon atoms, more preferably 2 or less carbon atoms, and preferably 1 or more carbon atoms. Examples of the hydroxyalkyl group of R ² include the same as those ^{of R 1 described above.}
Among these, R ² is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyalkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom.

The carbon number of the alkanediyl group of R ³ and R ⁴ is preferably 4 or less, more preferably 3 or less, still more preferably 2 or less, still more preferably 1.
Examples of the alkanediyl group of R ³ and R ⁴ include a methylene group, an ethylene group, a trimethylene group, a propane-1,2-diyl group and a tetramethylene group, and a methylene group is preferable.

Examples of the polyhydroxyamine compound include 2-amino-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, and the like. 2-Amino-2-hydroxymethyl-1,3-propanediol, 2-amino-2-hydroxyethyl-1,3-propanediol, 4-amino-4-hydroxypropyl-1,7-heptanediol, 2- (N-ethyl) amino-1,3-propanediol, 2- (N-ethyl) amino-2-hydroxymethyl-1,3-propanediol, 2- (N-decyl) amino-1,3-propanediol , 2- (N-decyl) amino-2-hydroxymethyl-1,3-propanediol.
Among these, 2-amino-2-hydroxymethyl-1,3-propanediol and 2-amino-2 are used from the viewpoint of further improving the chargeability of the toner and removing the residual organic solvent more efficiently. -Hydroxyethyl-1,3-propanediol, 2-amino-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-ethyl-1,3- At least one selected from propanediol is preferable, and at least one selected from 2-amino-2-hydroxymethyl-1,3-propanediol and 2-amino-1,3-propanediol is more preferable, and 2-. Amino-2-hydroxymethyl-1,3-propanediol is more preferred.
As the above polyhydroxyamine compound, one kind or two or more kinds can be used. The polyhydroxyamine compound can be produced by a conventional method.

The amount of the polyhydroxyamine compound is preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more, based on 100 parts by mass of the polymerizable monomer, from the viewpoint of further improving the color development property of the toner. It is more preferably 0.1 parts by mass or more, and preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, still more preferably 1 part by mass or less, still more preferably 0.8 parts by mass or less, and further. It is preferably 0.5 parts by mass or less.

[Colorant]
As the colorant, pigments and dyes are used, and pigments are preferable from the viewpoint of further improving the effect of color development. As the pigment, either an inorganic pigment or an organic pigment can be used, but an organic pigment is preferable.
Examples of the inorganic pigment include carbon black and an inorganic composite oxide.
Examples of the organic pigment include a yellow pigment, a magenta pigment, and a cyan pigment.
Examples of magenta organic pigments include monoazo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, base dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, C.I. 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, C.I. I. Pigment Bio Red 19. Among these, the naphthol compound is preferable, and C.I. I. Pigment Red 269 is more preferred.

Examples of the cyan organic pigment include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds. More specifically, C.I. I. Pigment Blue 1,7,15,15: 1,15: 2,15: 3,15: 4,60,62,66. Among these, copper phthalocyanine compounds are preferable, and C.I. I. Pigment Blue 15: 3 is more preferred.

Examples of the yellow organic pigment include monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, isoindolin compounds, benzimidazolone compounds, anthraquinone compounds, azo metal complexes, and methine compounds, and more specifically. , C.I. I. Pigment Yellow 17, 74, 93, 95, 109, 111, 128, 139, 151, 154, 155, 174, 180, 185. Among these, monoazo compounds are preferable, and C.I. I. Pigment Yellow 74 is more preferred.
Examples of the dye include acridine-based, azo-based, benzoquinone-based, azine-based, anthraquinone-based, indigo-based, phthalocyanine-based, and aniline black-based dyes. One or more of these may be used.

The amount of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 3 parts by mass or more with respect to 100 parts by mass of the polymerizable monomer from the viewpoint of improving the color development property of the toner. And preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less.

[Polymerization initiator]
Examples of the polymerization initiator include known polymerization initiators, and examples thereof include azo compounds, organic peroxides, inorganic peroxides, organic metal compounds, and photopolymerization initiators.
Examples of the polymerization initiator include 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2-methylbutyronitrile), and 2,2'-azobis (4-methoxy-2,4). -Dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis (isobutyrate) and other azo-based polymerization initiators, dilauryl peroxide and other aliphatic diacyl peroxides Initiation of organic peroxide-based polymerization such as oxide-based polymerization initiator, benzoyl peroxide, ditert-butyl peroxide, tert-butylperoxyisopropyl monocarbonate, tert-hexylperoxybenzoate, and tert-butylperoxybenzoate. Agents, inorganic peroxide-based polymerization initiators such as potassium persulfate and ammonium persulfate, hydrogen peroxide-ferrous iron-based, BPO-dimethylaniline-based, cerium (IV) salt-alcohol-based redox initiators, etc. Be done. Examples of the photopolymerization initiator include acetophenone-based, benzoin ether-based, and ketal-based agents. One or more of these may be used.
Among these, an azo-based polymerization initiator and an aliphatic diacyl peroxide-based polymerization initiator are preferable, and 2,2'-azobis (2,4-dimethylvaleronitrile) and dilauryl peroxide are more preferable.

The amount of the polymerization initiator is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, still more preferably 0.5 part by mass or more, based on 100 parts by mass of the polymerizable monomer, from the viewpoint of improving the color development property of the toner. Is 1 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, still more preferably 5 parts by mass or less.

[Polyester resin]
The suspension preferably contains a polyester resin from the viewpoint of further improving the color development property. The polyester resin is, for example, a polycondensate of an alcohol component and a carboxylic acid component.

〔式中、ＲＯ及びＯＲはオキシアルキレン基であり、Ｒはエチレン基及びプロピレン基から選ばれる少なくとも１種であり、ｘ及びｙはアルキレンオキサイドの平均付加モル数を示し、それぞれ正の数であり、ｘとｙの和の値は、１以上であり、好ましくは１．５以上であり、そして、１６以下であり、好ましくは８以下、より好ましくは４以下である。〕で表されるビスフェノールＡのアルキレンオキサイド付加物である。 Examples of the alcohol component include aromatic polyols and aliphatic polyols.
The aromatic polyol is preferably an alkylene oxide adduct of bisphenol A, more preferably of the formula (I) :.

[In the formula, RO and OR are oxyalkylene groups, R is at least one selected from an ethylene group and a propylene group, and x and y indicate the average number of moles of alkylene oxide added, each of which is 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 4 or less. ] Is an alkylene oxide adduct of bisphenol A.

Examples of the alkylene oxide adduct of bisphenol A represented by the formula (I) include a propylene oxide adduct of 2,2-bis (4-hydroxyphenyl) propane and 2,2-bis (4-hydroxyphenyl) propane. Ethylene oxide adducts of. One or more of these may be used.

The content of the alkylene oxide adduct of bisphenol A represented by the formula (I) is preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, still more preferably 80 mol% or more in the alcohol component. 90 mol% or more, more preferably 95 mol% or more, and 100 mol% or less, and preferably 100 mol%.

Examples of the aliphatic polyol include trivalent or higher aliphatic alcohols such as aliphatic diols having 2 or more and 20 or less carbon atoms and glycerin.
Examples of the aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-. Examples thereof include butenediol, 1,3-butanediol, neopentyl glycol, 1,10-decanediol, and 1,12-dodecanediol.

The carboxylic acid component preferably contains a dicarboxylic acid. The dicarboxylic acid may be an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid.
Hereinafter, examples of carboxylic acids include not only the compounds, but also anhydrides that decompose to produce acids during the reaction, and alkyl esters of each carboxylic acid having 1 or more and 3 or less carbon atoms.

Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid. Among these, terephthalic acid or isophthalic acid is more preferable, and terephthalic acid is further preferable. These can be used alone or in combination of two or more.
The content of the aromatic dicarboxylic acid is preferably 10 mol% or more, more preferably 30 mol% or more, still more preferably 50 mol% or more, and 100 mol% or less, preferably 95 mol% or more in the carboxylic acid component. % Or less, more preferably 90 mol% or less.

Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, dodecanedioic acid, dodecenyl succinic acid, and octylsuccinic acid. Examples thereof include aliphatic dicarboxylic acids such as succinic acid substituted with an alkyl group having 1 or more and 20 or less or an alkenyl group having 2 to 20 carbon atoms. These can be used alone or in combination of two or more.
The content of the aliphatic dicarboxylic acid is preferably 10 mol% or more, more preferably 15 mol% or more, still more preferably 20 mol% or more, and preferably 90 mol% or less, more preferably 90 mol% or more, in the carboxylic acid component. It is 70 mol% or less, more preferably 50 mol% or less.

Further, the carboxylic acid component preferably contains a carboxylic acid having a valence of 3 or more from the viewpoint of productivity.
Examples of trivalent or higher valent carboxylic acids include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, and pyromellitic acid. Of these, trimellitic acid or an acid anhydride thereof is preferable.

The content of the trivalent or higher carboxylic acid is preferably 1 mol% or more, more preferably 3 mol% or more, further preferably 5 mol% or more, and preferably 50 mol% or less, among the carboxylic acid components. It is more preferably 40 mol% or less, still more preferably 20 mol% or less, still more preferably 10 mol% or less.

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

The equivalent ratio (COOH group / OH group) of the carboxylic acid component to the alcohol component is preferably 0.7 or more, more preferably 0.8 or more, and preferably 1. It is 3 or less, more preferably 1.2 or less.

The polycondensation of the alcohol component and the carboxylic acid component should be carried out, for example, in an inert gas atmosphere at a temperature of about 180 ° C. or higher and 250 ° C. or lower in the presence of an esterification catalyst, a polymerization inhibitor, etc., if necessary. Can be done. Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropyrate bistriethanol aminated. Examples of the esterification co-catalyst that can be used together with the esterification catalyst include gallic acid and the like. 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 part by mass with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Parts or less, more preferably 0.6 parts by mass or less. The amount of the esterification co-catalyst used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. It is 5.5 parts by mass or less, more preferably 0.1 parts by mass or less.

The softening point of the polyester resin is preferably 80 ° C. or higher, more preferably 85 ° C. or higher, further preferably 90 ° C. or higher, and preferably 120 ° C. or lower, more preferably 110 ° C. or lower, still more preferably 100 ° C. or lower. Is.

The glass transition temperature of the polyester resin is preferably 42 ° C. or higher, more preferably 45 ° C. or higher, and preferably 80 ° C. or lower, more preferably 70 ° C. or lower, further, from the viewpoint of further improving the color development property of the toner. It is preferably 60 ° C. or lower, more preferably 55 ° C. or lower, still more preferably 50 ° C. or lower.

The acid value of the polyester resin is preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, still more preferably 10 mgKOH / g or less, and preferably 1 mgKOH / g, from the viewpoint of further improving the color development property of the toner. Above, more preferably 3 mgKOH / g or more.

The hydroxyl value of the polyester resin is preferably 60 mgKOH / g or less, more preferably 40 mgKOH / g or less, still more preferably 30 mgKOH / g or less, still more preferably 20 mgKOH / g or less, from the viewpoint of further improving the color development property of the toner. And, preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, still more preferably 14 mgKOH / g or more.

The weight average molecular weight of the polyester resin is preferably 3,000 or more, more preferably 5,000 or more, still more preferably 8,000 or more, still more preferably 10,000 or more, from the viewpoint of further improving the color development property of the toner. Yes, and preferably 100,000 or less, more preferably 50,000 or less, still more preferably 20,000 or less, still more preferably 17,000 or less.

The method for measuring the softening point, the glass transition temperature, the acid value, the hydroxyl value, and the weight average molecular weight is as described in Examples. When two or more kinds of resins are contained, it is preferable that the weighted average values of the softening point, the glass transition temperature, the acid value, the hydroxyl value, and the weight average molecular weight are in the above ranges.

The amount of the polyester resin is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 3 parts by mass or more with respect to 100 parts by mass of the polymerizable monomer from the viewpoint of improving the color development property of the toner. It is more preferably 5 parts by mass or more, further preferably 10 parts by mass or more, and preferably 25 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less.

[Charge control agent]
The suspension may contain a charge control agent.
The charge control agent may contain either a positive charge control agent or a negative charge control agent.
Positive charge control agents include niglosin dyes such as "niglosin base EX", "oil black BS", "oil black SO", "bontron N-01", "bontron N-04", and "bontron N-07". , "Bontron N-09", "Bontron N-11" (all manufactured by Orient Chemical Industries Co., Ltd.), etc .; Triphenylmethane dyes containing a tertiary amine as a side chain, for example, a quaternary ammonium salt compound, for example, " Bontron P-51 "(manufactured by Orient Chemical Industries Co., Ltd.), cetyltrimethylammonium bromide," COPY CHARGE PX VP435 "(manufactured by Clariant), etc .; Imidazole derivatives such as "PLZ-2001" and "PLZ-8001" (manufactured by Shikoku Kasei Kogyo Co., Ltd.); styrene-acrylic resins such as "FCA-701PT" (manufactured by Fujikura Kasei Co., Ltd.) Be done.

Examples of the negative charge control agent include metal-containing azo dyes such as "Varifast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", and "Bontron S-36" ( (Manufactured by Orient Chemical Industry Co., Ltd.), "Eisenspiron Black TRH", "T-77" (manufactured by Hodoya Chemical Industry Co., Ltd.), etc .; Metal compounds of benzylic acid compounds, for example, "LR-147", " LR-297 "(above, manufactured by Nippon Carlit Co., Ltd.); metal compounds of salicylic acid compounds, for example," Bontron E-81 "," Bontron E-84 "," Bontron E-88 "," Bontron E-304 " (The above is manufactured by Orient Chemical Industry Co., Ltd.), "TN-105" (manufactured by Hodoya Chemical Industry Co., Ltd.), etc .; Copper phthalocyanine dye; Quadruple ammonium salt, for example, "CompY CHARGE NX VP434" (manufactured by Clariant), Nitro Imidazole derivatives and the like; organic metal compounds and the like can be mentioned.
These may be used alone or in combination of two or more.
Among the charge control agents, a negative charge control agent is preferable, and a metal compound of a benzylic acid compound or a metal compound of a salicylic acid compound is more preferable.

The content of the charge control agent is preferably 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, and preferably 10 parts by mass or less, based on 100 parts by mass of the polymerizable monomer. It is more preferably 5 parts by mass or less, further preferably 3 parts by mass or less, still more preferably 2 parts by mass or less.

〔Release agent〕
The suspension may contain a release agent.
Examples of the release agent include wax.
Examples of the wax include hydrocarbon wax, ester wax, silicone wax, and fatty acid amide wax.
Examples of the hydrocarbon wax include mineral or petroleum hydrocarbon wax such as paraffin wax and Fishertroph wax; and synthetic hydrocarbon wax such as polyolefin wax such as polyethylene wax, polypropylene wax and polybutene wax.
Examples of the ester wax include mineral or petroleum ester wax such as Montan wax; plant-based ester wax such as carnauba wax, rice wax and candelilla wax; and animal-based ester wax such as honey wax.
Examples of the fatty acid amide wax include oleic acid amide and stearic acid amide.
Among these, from the viewpoint of toner releasability, hydrocarbon wax or ester wax is preferable, hydrocarbon wax is more preferable, paraffin wax, Fishertropch wax, and polyolefin wax are more preferable, and paraffin wax is further preferable.

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 from the viewpoint of toner releasability, 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.
The melting point of the release agent is determined by the method described in Examples.

From the viewpoint of mold release property of the toner, the amount of the release agent is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 3 parts by mass or more with respect to 100 parts by mass of the polymerizable monomer. And preferably 25 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less.

In step 1, from the viewpoint of further improving the color development property, it is preferable to mix the polyhydroxyamine compound and the polymerizable monomer before obtaining the suspension.
More specifically, step 1 is preferably a step including the following steps 1-1 and 1-2.
Step 1-1: A step of obtaining a mixed solution containing a polymerizable monomer, a polyhydroxyamine compound, a colorant and a polymerization initiator Step 1-2: The mixed solution is put into an aqueous medium and suspended. Step to get

In step 1-1, the mixed solution is preferably a mixed solution in which the polymerizable monomer, the polyhydroxyamine compound, and the colorant are heated and mixed to uniformly dissolve each component.
Here, it is preferable to mix the polyester resin, the charge control agent, and the mold release agent.
The mixing temperature is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, still more preferably 50 ° C. or higher, and preferably 80 ° C. or lower, more preferably 70 ° C. or lower, still more preferably 65 ° C. or lower.
After obtaining the dissolved mixed solution, it is preferable to add a polymerization initiator and mix.

In step 1-2, the aqueous medium may be a mixed aqueous medium mixed with a dispersion stabilizer and a surfactant.
(Dispersion stabilizer)
Examples of the dispersion stabilizer include carbonates, metal phosphates, sulfates, and metal hydroxides. Examples of the carbonate include barium carbonate, calcium carbonate, and magnesium carbonate. Examples of the metal phosphate salt include aluminum phosphate, magnesium phosphate, calcium phosphate, barium phosphate, and zinc phosphate. Examples of the sulfate include barium sulfate and calcium sulfate. Examples of the metal hydroxide include calcium hydroxide, aluminum hydroxide, magnesium hydroxide, and ferric hydroxide. Among these, a metal phosphate salt is preferable, and calcium phosphate is more preferable.
The amount of the dispersion stabilizer is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or more in the mixed aqueous medium. It is mass% or less, more preferably 10 mass% or less.

(Surfactant)
As the surfactant, various surfactants such as anionic surfactant, cationic surfactant, and nonionic surfactant can be used. Of these, anionic surfactants are preferred.
Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl sulfate, and polyoxyalkylene alkyl ether sulfate.
Examples of the alkylbenzene sulfonate include dodecylbenzene sulfonate. Examples of the alkyl sulfate include dodecyl sulfate. The polyoxyalkylene alkyl ether sulfate is preferably a polyoxyethylene alkyl ether sulfate, and examples thereof include polyoxyethylene lauryl ether sulfate. One or more of these may be used. As the salt, an alkali metal salt is preferable, and a sodium salt is more preferable.
Among these, alkylbenzene sulfonate and polyoxyalkylene alkyl ether sulfate are preferable, dodecylbenzene sulfonate and polyoxyethylene lauryl ether sulfate are more preferable, and sodium dodecylbenzene sulfonate is further preferable.
The amount of the surfactant is preferably 1 mass ppm or more, more preferably 3 mass ppm or more, further preferably 5 mass ppm or more, and preferably 30 mass ppm or less, more preferably 20 mass ppm or more in the mixed aqueous medium. It is mass ppm or less, more preferably 10 mass ppm or less.

In step 1-2, the temperature at which the mixed liquid is put into the aqueous medium is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, still more preferably 50 ° C. or higher, and preferably 80 ° C. or lower. It is preferably 70 ° C. or lower, more preferably 65 ° C. or lower.

It is preferable to mix by stirring at the time of charging.
As the device used in this step, for example, it can be performed in a vertical stirring tank equipped with a stirring machine having a high shearing force. Commercially available products of agitators with high shearing force include, for example, "High Share Mixer" (manufactured by IKA), "TK Homomixer", and "TK Fillmix" (above, Special Machinery Industrial Co., Ltd.). (Manufactured by the company) and Clairemix (manufactured by M Technique Co., Ltd.).
The stirring speed is preferably 1,000 r / min or more, more preferably 5,000 r / min or more, further preferably 8,000 r / min or more, and preferably 30,000 r / min or less, more preferably 20. It is 000 r / min or less, more preferably 15,000 r / min or less.

<Process 2>
In step 2, the polymerizable monomer is polymerized in the suspension.
The polymerization temperature is preferably 50 ° C. or higher, more preferably 55 ° C. or higher, further preferably 60 ° C. or higher, and preferably 90 ° C. or lower, more preferably 80 ° C. or lower, still more preferably 75 ° C. or lower. ..
The polymerization is preferably carried out with stirring. The device used is not particularly limited.
The stirring speed is preferably 50 r / min or more, more preferably 100 r / min or more, still more preferably 150 r / min or more, and preferably 1,000 r / min or less, more preferably 500 r / min or less, still more preferably. Is 300 r / min or less.

After the polymerization, it is preferable to add a mineral acid from the viewpoint of dissolving the dispersion stabilizer and facilitating the separation of the toner particles.
Examples of the mineral acid include hydrochloric acid, sulfuric acid and the like.
After the polymerization, it is preferable to obtain toner particles by solid-liquid separation. After solid-liquid separation, it may be washed and dried. Examples of the drying method include a vacuum low temperature drying method, a vibration type fluid drying method, a spray drying method, a freeze drying method, and a flash jet method.

The volume medium particle size (D ₅₀ ) of the obtained toner particles is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more, and preferably 20 μm or less from the viewpoint of obtaining a high-quality image. , More preferably 15 μm or less, still more preferably 10 μm or less.
The CV value of the toner particles is preferably 12% or more, more preferably 15% or more, further preferably 20% or more, and preferably 35% or less, more preferably 30 from the viewpoint of obtaining a high-quality image. % Or less.
The volume median particle size (D ₅₀ ) and CV value are measured by the methods described in the Examples.

The glass transition temperature of the toner particles is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, and preferably 80 ° C. or lower, more preferably 75 ° C. or lower, still more preferably 70 ° C. or lower, still more preferably 65 ° C. It is as follows.
The glass transition temperature of the toner particles is measured by the method described in Examples.

<Step 3>
The method for producing toner may further include a step of mixing the obtained toner particles with an external additive.
Examples of the external additive include inorganic fine particles such as hydrophobic silica, titanium oxide, alumina, cerium oxide and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate and silicone. Among these, hydrophobic silica is preferable.
The average particle size of the external additive is preferably 1 nm or more, more preferably 5 nm or more, further preferably 10 nm or more, and preferably 500 nm or less, more preferably 300 nm or less, still more preferably 100 nm or less.
When surface treatment of toner particles is performed using an external additive, the amount of the external additive added is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, based on 100 parts by mass of the toner particles. It is more preferably 1 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.

The toner is used for developing a latent image formed by an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or the like. In addition, the toner can be used as a one-component developer or mixed with a carrier and used as a two-component developer.

Each physical property value of the resin and the like was measured and evaluated by the following method.

[Measuring method]
[Acid value and hydroxyl value of resin]
The acid value and hydroxyl value of the resin and the hydrocarbon wax are measured based on the method of JIS K 0070: 1992. However, only the measurement solvent is changed from the mixed solvent of ethanol and ether specified in JIS K 0070: 1992 to the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Maximum endothermic temperature, melting point, glass transition temperature, and crystallinity index of resin and toner particles]
Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 to 0.02 g of a sample into an aluminum pan, and cool from room temperature (20 ° C) to a temperature lowering rate of 10 ° C / Cool to 0 ° C. in min and hold for 1 minute. Then, the temperature rise rate was measured at 50 ° C./min. Of the observed endothermic peaks, the temperature of the peak that appears on the highest temperature side is defined as the maximum endothermic temperature of the resin. The ratio of the softening point of the resin to the maximum endothermic peak temperature (softening point (° C.) / maximum endothermic peak temperature (° C.)) is defined as the crystallinity index. If the maximum endothermic peak temperature is within 20 ° C. from the softening point, the melting point is used, and if the difference exceeds 20 ° C., the glass transition temperature is used.
The glass transition temperature of the toner particles was calculated from the peak derived from the addition polymer of the polymerizable monomer in the toner particles.

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

[Weight average molecular weight of resin]
The molecular weight distribution is measured by the gel permeation chromatography (GPC) method by the following method, and the weight average molecular weight of the resin is determined.
(1) Preparation of sample solution Dissolve the sample in tetrahydrofuran at 25 ° C. so that the concentration becomes 0.5 g / 100 mL. Next, this solution is filtered using a fluororesin filter "DISMIC-25JP" (manufactured by ADVANTEC) having a pore size of 0.2 μm to remove insoluble components, and the solution is used as a sample solution.
(2) Molecular weight measurement Using the following measuring device and analytical column, tetrahydrofuran is flowed as an eluent at a flow rate of 1 mL per minute to stabilize the column in a constant temperature bath at 40 ° C. 100 μL of the sample solution is injected therein and the measurement is performed. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. At this time, the calibration curve includes several types of monodisperse polystyrene (“A-500” (5.0 × 10 ² ), “A-1000” (1.01 × 10 ³ ), “A-2500” (2. 63 × 10 ³ ), “A-5000” (5.97 × 10 ³ ), “F-1” (1.02 × 10 ⁴ ), “F-2” (1.81 × 10 ⁴ ), “F” -4 ”(3.97 × 10 ⁴ ),“ F-10 ”(9.64 × 10 ⁴ ),“ F-20 ”(1.90 × 10 ⁵ ),“ F-40 ”(4.27 ×) 10 ^5), "F-80" (7.06 × 10 ^5), "F-128" (1.09 × 10 ⁶⁾ (manufactured by Tosoh Corporation)) and used was developed as a standard sample.
Measuring device: "HLC-8220GPC" (manufactured by Tosoh Corporation)
Analytical column: "GMHXL" + "G3000HXL" (all manufactured by Tosoh Corporation)

[Melting point of mold release agent]
Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.02 g of a sample into an aluminum pan, raise the temperature to 200 ° C, and then lower the temperature from 200 ° C to 10 ° C. Cool to 0 ° C. at / min. Next, the sample is heated at a heating rate of 10 ° C./min, the amount of heat is measured, and the maximum peak temperature of endotherm is taken as the melting point.

[Volume medium particle size (D ₅₀ ) and CV value of toner particles]
The volume median particle diameter (D ₅₀ ) of the toner particles was measured by the following method.
Measuring machine: Coulter Multisizer II (manufactured by Beckman Coulter)
Aperture diameter: 50 μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (manufactured by Beckman Coulter)
Electrolyte: Isoton II (manufactured by Beckman Coulter)
Dispersion: Emargen 109P (manufactured by Kao Co., Ltd., polyoxyethylene lauryl ether, HLB: 13.6) 5% by mass electrolyte Dispersion condition: Add 10 mg of the measurement sample to 5 mL of the dispersion and use an ultrasonic disperser for 1 minute. After dispersion, 25 mL of the electrolytic solution is added, and the mixture is further dispersed with an ultrasonic disperser for 1 minute.
Measurement conditions: Add 100 mL of electrolytic solution and dispersion to a beaker, measure 30,000 particles at a concentration that can measure the particle size of 30,000 particles in 20 seconds, and measure the particle size of 30,000 particles from the particle size distribution. D ₅₀ ) is calculated.
The CV value (%) was calculated according to the following formula.
CV value (%) = (standard deviation of particle size distribution / volume average particle size) x 100

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

[Evaluation method]
[Color development]
Toner was mounted on a copying machine "AR-505" (manufactured by Sharp Corporation), and an image was output without fixing (printing area: 2 cm x 12 cm, adhesion amount: 0.5 mg / cm ² ). The unfixed image was fixed at 160 ° C. and 50 mm / sec using a fixing machine that was removed from the copying machine "CX7700" (manufactured by Sharp Corporation) and whose temperature and speed could be controlled. As the fixing paper, "CopyBondo SF-70NA" (manufactured by Sharp Corporation, 75 g / m2) was used.
The obtained image was placed on top of 20 sheets of A4 copy paper (RPCA4R), and L ^* a ^* b ^* was measured with a color difference meter (manufactured by ^{Gretag), and √ ((a *} ) ² + ( b ^* ) ^{The value of 2} ) was calculated, and here, the color development property was evaluated according to the following evaluation criteria. The larger the value, the better the color reproducibility.
<Evaluation criteria>
A: 55 or more B: 53 or more and less than 55 C: 51 or more and less than 53 D: 49 or more and less than 51 E: less than 49

[Manufacturing of polyester resin]
Production Examples A1 to A6 (resins A-1 to A-6)
The alcohol components and terephthalic acid shown in Table 1 are placed in a dehydration tube equipped with a nitrogen introduction tube, a 10 L volume four-necked flask equipped with a stirrer and a thermocouple, and di (2-ethyl) at 140 ° C. under a nitrogen atmosphere. After adding hexanoic acid) tin (II) and gallic acid, the temperature was raised to 235 ° C. and a polycondensation reaction was carried out for 6 hours, and the reaction was further carried out at 235 ° C. and 8.0 kPa for 1 hour. After cooling to 180 ° C., the remaining acid components other than terephthalic acid are added, the temperature is raised from 180 ° C. to 210 ° C. at 10 ° C./hour, the reaction is carried out at 210 ° C. for 1 hour, and the temperature is 210 ° C. and 10 kPa. The reaction was carried out up to the softening point shown in the table to obtain resins A-1 to A-6.

[Manufacturing of toner]
Example 1, Comparative Example 1 (Manufacturing of Toners 1, 51)
In a 300 mL glass beaker, the polymerizable monomer shown in Table 2, the colorant "Pigment Blue 15: 3" (manufactured by Dainichiseika Kogyo Co., Ltd.) 5 g, and the charge control agent "Bontron E-88" (Orient Chemical Industries Co., Ltd.) Add 1 g of aluminum salicylate (manufactured by Nippon Seiwa Co., Ltd.), 10 g of mold release agent "HNP-9" (paraffin wax manufactured by Nippon Seiwa Co., Ltd., melting point: 75.5 ° C.) and the polyhydroxyamine shown in the table, and stir and mix. Then, the temperature was raised to 60 ° C. to prepare a uniform solution. After that, 3 g of the polymerization initiator "V-65" (manufactured by Wako Pure Chemical Industries, Ltd., 2,2'-azobis (2,4-dimethylvaleronitrile)) and the polymerization initiator "Parloyl L" (manufactured by NOF CORPORATION) ) 1 g was added to prepare a resin solution. In a 1 L glass beaker, 150 g of ion-exchanged water, calcium phosphate tricalcium (3 [Ca ₃ (PO ₄ ) ₂ ], Ca (OH) ₂ ) 10 mass% slurry "TCP-10, U" (Taipei Chemical Industry Co., Ltd.) (Manufactured by) 500 g and 0.004 g of anionic surfactant "Neoperex G-15" (manufactured by Kao Co., Ltd., sodium dodecylbenzene sulfonate) were added and stirred to prepare an aqueous medium. The aqueous medium is heated to 60 ° C., the resin solution is added all at once while maintaining 60 ° C., and the mixture is stirred with "Homomixer MARKII 2.5 type" (manufactured by Primix Corporation) at 12,000 r / min for 4 minutes. A suspension was obtained.

The suspension was transferred to a separable flask and polymerized for 8 hours with stirring at 70 ° C. and 200 r / min. Then, the temperature was raised to 80 ° C., and the residual monomer was distilled off under reduced pressure. The mixture was cooled to 20 ° C. while continuing stirring, and hydrochloric acid was added until the pH in the system became 1 or less. After washing and drying, toner particles having a volume medium particle size (D ₅₀ ) of 8.0 μm were obtained.

<External process>
To 100 parts by mass of the obtained toner particles, 1.0 part by mass of hydrophobic silica "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd., average particle size: 16 nm) was added as an external additive, and 3600 r / with a Henschel mixer. By mixing for min and 5 minutes, an external additive treatment was performed to obtain toners 1,51. The obtained toner was evaluated and shown in Table 2.

Examples 2 to 12 and Comparative Example 2 (manufacturing of toners 2 to 12, 52)
Toners 2 to 12, 52 were obtained in the same manner as in Example 1 except that the monomer was changed to the polymerizable monomer shown in Table 2 and the polyester resin shown in Table 2 was further added together with the raw material monomer. The obtained toner was evaluated and shown in Table 2.

As shown in Examples and Comparative Examples, it can be seen that the toner of Examples is excellent in color development by using a suspension containing a polyhydroxyamine compound.

Claims (7)

A step of obtaining a suspension containing a polymerizable monomer, a polyhydroxyamine compound represented by the following formula (1), a colorant, and a polymerization initiator in an aqueous medium.
A method for producing an electrophotographic toner, which comprises a step of polymerizing a polymerizable monomer in the suspension .
A method for producing an electrophotographic toner, wherein the polyhydroxyamine compound is 2-amino-2-hydroxymethyl-1,3-propanediol .

Wherein, R ¹ represents a hydroxyalkyl group having a carbon number of 1, R ² represents a hydrogen atom, R ³ and R ⁴ represents an alkanediyl group having one carbon atom. ] In the step of obtaining the suspension,
A step of obtaining a mixed solution containing the polymerizable monomer, the polyhydroxyamine compound, the colorant and the polymerization initiator, and a step of putting the mixed solution into an aqueous medium to obtain a suspension. The method for producing an electrophotographic toner according to claim 1. The method for producing an electrophotographic toner according to claim 1 or 2 , wherein the suspension contains a styrene compound and a (meth) acrylic acid ester as the polymerizable monomer. The production of the electrophotographic toner according to any one of claims 1 to 3 , wherein the amount of the polyhydroxyamine compound is 0.01 part by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. Method. The method for producing an electrophotographic toner according to any one of claims 1 to 4 , wherein the suspension contains a polyester resin which is a polycondensate of an alcohol component and a carboxylic acid component. The method for producing an electrophotographic toner according to claim 5 , wherein the polyester resin is a polycondensate of an alcohol component containing 80 mol% or more of an alkylene oxide adduct of bisphenol A and a carboxylic acid component. The polyester resin has an acid value of 1 mgKOH / g or more 30 mgKOH / g or less, the hydroxyl value 5 mgKOH / g or higher 60 mg KOH / g or less, and a glass transition temperature of 80 ° C. or less 42 ° C. or higher, according to claim 5 Alternatively, the method for producing an electrophotographic toner according to 6.