阅读说明：本技术 黄色调色剂 (Yellow toner ) 是由 赤崎浩二朗 于 2018-12-21 设计创作，主要内容包括：本发明可提供一种黄色调色剂,其以少的调色剂量呈现比现有调色剂更鲜明的色彩和更明亮的光泽,反射密度高,且具有优异的耐光性。该黄色调色剂的特征在于,含有粘结树脂和黄色着色剂,作为上述黄色着色剂,包含下述通式(1)表示的化合物A和下述通式(2)表示的化合物B中的至少任一种,以及下述式(3)表示的化合物C。<Image he="855" wi="700" file="DDA0002554406980000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The present invention can provide a yellow toner which exhibits a clearer color and brighter gloss with a small toner amount than conventional toners, has a high reflection density, and has excellent light resistance. The yellow toner is characterized by containing a binder resin and a yellow colorant, and containing a compound A represented by the following general formula (1) and a compound represented by the following general formula (2) as the yellow colorantAt least one of the compounds B, and a compound C represented by the following formula (3).)

1. A yellow toner is characterized by containing a binder resin and a yellow colorant,

the yellow colorant comprises at least 1 of a compound A represented by the following general formula (1) and a compound B represented by the following general formula (2), and a compound C represented by the following general formula (3),

general formula (1)

In the general formula (1), R^1A、R^1B、R^2AAnd R^2BEach independently represents a halogen atom, an alkyl group, an alkoxy group, an amino group, a nitro group, or an acetamido group, i.e., -NHCOCH₃Carbomethoxy, i.e., -COOCH₃Primary amide group, i.e. -CONH₂Or an aromatic amide group, i.e., -CONHAR,

R^3Aand R^3BEach independently represents a halogen atom or an alkyl group,

R⁴and R⁵Each independently represents a halogen atom, an alkyl group, a methoxy group, an amino group, a nitro group, or an acetamido group, i.e., -NHCOCH₃Acetyl group or-COCH₃Carbomethoxy, i.e., -COOCH₃Or primary amide groups, i.e. -CONH₂，

The sum of a1 and b1 is a non-negative integer of 1 or more and 3 or less,

the sum of a2 and b2 is a non-negative integer of 1 or more and 3 or less,

the sum of c1 and c2 is a non-negative integer of 0 or more and 3 or less,

d and e are each independently 1 or 2,

wherein Ar represents an aryl group having 6 to 10 carbon atoms which may have a substituent,

general formula (2)

In the general formula (2), R^6AAnd R^6BEach independently represents a halogen atom, an alkyl group, an alkoxy group, an amino group, a nitro group, or an acetamido group, i.e., -NHCOCH₃Carbomethoxy, i.e., -COOCH₃Primary amide group, i.e. -CONH₂Or an aromatic amide group, i.e., -CONHAR,

R⁷and R⁸Each independently represents a halogen atom, an alkyl group, a methoxy group, an amino group, a nitro group, or an acetamido group, i.e., -NHCOCH₃Acetyl group or-COCH₃Carbomethoxy, i.e., -COOCH₃Or primary amide groups, i.e. -CONH₂，

The sum of f1 and f2 is a non-negative integer of 1 or more and 3 or less,

g represents an integer of 0 to 3 inclusive,

h is 1 or 2, and h is a linear alkyl group,

wherein Ar represents an aryl group having 6 to 10 carbon atoms which may have a substituent,

formula (3)

2. The yellow toner according to claim 1, wherein the compound a and the compound B are yellow pigments, and the compound C is a yellow dye.

3. The yellow toner according to claim 1 or 2, wherein the total content of the compound a and the compound B is 1 to 15 parts by mass, and the content of the compound C is 0.1 to 8.0 parts by mass, with respect to 100 parts by mass of the binder resin.

4. The yellow toner according to any one of claims 1 to 3, wherein a mass ratio of the total content of the compound A and the compound B to the content of the compound C, that is, (compound A + compound B)/compound C, is 0.1 to 10.

Technical Field

The present invention relates to a yellow toner which exhibits a clearer color and brighter gloss with a small toner amount than conventional toners, has a high reflection density, and has excellent light resistance.

Background

In an image forming apparatus such as an electrophotographic apparatus and an electrostatic recording apparatus, an electrostatic latent image formed on a photoreceptor is first developed with toner. The formed toner image is then transferred to a transfer material such as paper, and then fixed by various means such as heating, pressurization, or solvent evaporation.

In such image forming apparatuses, digital full-color copiers and digital full-color printers are being put into practical use. The digital full-color copier decomposes a color image document using blue, green, and red color filters, develops an electrostatic latent image formed with a dot diameter of 20 to 70 μm corresponding to the original color document using yellow, magenta, cyan, and black toners, and forms a full-color image by subtractive color mixing.

In recent years, there has been an increasing demand for high image quality and high definition of the full-color image. In particular, in order to improve color reproducibility, it is desirable to be able to perform printing with the same color tone as ink printing.

As a conventional coloring pigment for yellow toner, a disazo pigment represented by c.i. pigment yellow 12, 13, and 17, a monoazo pigment represented by c.i. pigment yellow 97 and 98, or the like is generally used.

Patent document 1 discloses a yellow toner containing c.i. pigment yellow 155 (azo pigment) and c.i. pigment yellow 110 as yellow colorants at a predetermined ratio. Patent document 1 describes the following: by using such a colorant, the overprint ink can have excellent high-temperature offset resistance even in a heat-and-pressure fixing method in which oil is not used or the amount of oil used is reduced, and can achieve both long-term storage stability in a high-temperature environment and low-temperature fixability, and can cover the color tone (color reproduction range) of the overprint ink.

Further, an example is known in which an attempt is made to improve the toner characteristics by combining a yellow pigment and a yellow dye in addition to the combination of the yellow pigments with each other.

Patent document 2 discloses a yellow toner containing an azo condensation pigment such as c.i. pigment yellow 93 and the like and c.i. solvent yellow 162. Patent document 2 describes the following: by using the c.i. solvent yellow 162, the coagulation of the azo condensation pigment such as the c.i. pigment yellow 93 can be suppressed, the dispersibility of the azo condensation pigment can be improved, and more uniform triboelectrification can be obtained.

Patent document 3 discloses a yellow toner containing c.i. pigment yellow 74 and c.i. solvent yellow 162. Patent document 3 describes the following: by containing these colorants, good hue of the toner in the case of containing c.i. pigment yellow 74 alone and high tinctorial strength of c.i. solvent yellow 162 can be obtained.

Disclosure of Invention

Problems to be solved by the invention

As an image forming apparatus of an electrophotographic system, applications thereof have been expanded from a general copying machine and a printer used for printing and simple copying of documents in offices to a field of manufacturing printed matters for use in offices, specifically, from a field of enabling variable information to be easily printed from electronic data to a field of on-demand Printing (POD) market as a field of rapid printing. Therefore, in recent years, the level of the demand for chroma, gloss, and reflection density of printed matter has been rapidly increasing.

However, the yellow toners disclosed in patent documents 1 to 3 cannot be applied to the above-described various applications for various reasons described below.

First, the combination of colorants described in patent document 1 (c.i. pigment yellow 155, c.i. pigment yellow 110, etc.) has a problem that the coloring power of these 2 pigments is low and the reflection density is low, and further, the individual pigments have a problem that the color difference is large and the color becomes dull when combined.

In addition, dyes, unlike pigments, are soluble in solvents and have the property of being not light-fast. Therefore, in the case of combining a dye and a pigment, there is a problem that light fastness of the toner is lowered depending on the kind of combination. The combination of colorants described in patent document 2 (c.i. pigment yellow 93 and the like and c.i. solvent yellow 162) and the combination of colorants described in patent document 3 (c.i. pigment yellow 74 and c.i. solvent yellow 162) cannot solve such a problem of light resistance reduction.

Further, in the case of combining a pigment and a dye, it is known that the dye mainly plays a role of compensating for a short portion of the pigment (for example, a role of assisting a dispersion state of the pigment, or the like). Therefore, in the prior art of a toner combining a pigment and a dye, the dye itself improves, for example, gloss and the like as coloring characteristics of the toner, and has not been known so far.

From the viewpoint of downsizing and energy saving of the image forming apparatus, it is desirable to reduce the amount of toner consumed during printing. However, when printing with a smaller toner amount, there is a problem that chroma decreases and the color gamut becomes narrow. The toners described in patent documents 1 to 3 cannot ensure a sufficiently wide color gamut even when the toner is small.

In recent years, in order to apply the above-described various applications, the required levels of chroma, gloss, and reflection density of printed matter have been rapidly increased in recent years. In order to meet such a high level of demand, the present invention aims to provide a yellow toner which exhibits a clearer color and brighter gloss with a smaller amount of toner than conventional toners, has a high reflection density, and has excellent light resistance.

Means for solving the problems

The present inventors have conducted intensive studies in order to achieve the above object and, as a result, have found that a yellow toner having higher glossiness, reflection density and chroma than conventional toners and excellent light resistance can be obtained even with a small amount of toner by using a plurality of compounds having specific chemical structures in combination as a yellow colorant, thereby completing the present invention.

Specifically, the yellow toner of the present invention contains a binder resin and a yellow colorant, and the yellow colorant contains at least 1 of a compound a represented by the following general formula (1) and a compound B represented by the following general formula (2), and a compound C represented by the following general formula (3).

[ chemical formula 1]

General formula (1)

[ in the general formula (1), R^1A、R^1B、R^2AAnd R^2BEach independently represents a halogen atom, an alkyl group, an alkoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Methyl ester group (-COOCH)₃) Primary amide (-CONH)₂) Or an aromatic amide group (-CONHAR),

R^3Aand R^3BEach independently represents a halogen atom or an alkyl group,

R⁴and R⁵Each independently represents a halogen atom, an alkyl group, a methoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Acetyl (-COCH)₃) Methyl ester group (-COOCH)₃) Or primary amide group (-CONH)₂)，

a1 and b1 represent nonnegative integers whose sum is 1 or more and 3 or less,

a2 and b2 represent nonnegative integers whose sum is 1 or more and 3 or less,

c1 and c2 represent nonnegative integers whose sum is 0 or more and 3 or less,

d and e are each independently 1 or 2.

Wherein Ar represents an aryl group having 6 to 10 carbon atoms which may have a substituent. ]

[ chemical formula 2]

General formula (2)

[ in the general formula (2), R^6AAnd R^6BEach independently represents a halogen atom, an alkyl group, an alkoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Methyl ester group (-COOCH)₃) Primary amide (-CONH)₂) Or an aromatic amide group (-CONHAR),

R⁷and R⁸Each independently represents a halogen atom, an alkyl group, a methoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Acetyl (-COCH)₃) Methyl ester group (-COOCH)₃) Or primary amide group (-CONH)₂)，

f1 and f2 represent non-negative integers whose sum is 1 or more and 3 or less,

g represents an integer of 0 to 3 inclusive,

h is 1 or 2.

Wherein Ar represents an aryl group having 6 to 10 carbon atoms which may have a substituent. ]

[ chemical formula 3]

Formula (3)

In the present invention, the compound a and the compound B may be yellow pigments, and the compound C may be yellow dyes.

In the present invention, the total content of the compound a and the compound B may be 1 to 15 parts by mass and the content of the compound C may be 0.1 to 8.0 parts by mass, based on 100 parts by mass of the binder resin.

In the present invention, the mass ratio of the total content of the compound a and the compound B to the content of the compound C ((compound a + compound B)/compound C) may be 0.1 to 10.

Effects of the invention

According to the present invention as described above, by using at least any one of the compound a and the compound B and the compound C in combination, a yellow toner can be provided which is higher in glossiness, reflection density and chroma than conventional toners and is excellent in light resistance even if the toner amount is small.

Detailed Description

The yellow toner of the present invention contains a binder resin and a yellow colorant, and the yellow colorant contains at least 1 of a compound A represented by the following general formula (1) and a compound B represented by the following general formula (2), and a compound C represented by the following general formula (3).

[ chemical formula 4]

General formula (1)

[ in the general formula (1), R^1A、R^1B、R^2AAnd R^2BEach independently represents a halogen atom, an alkyl group, an alkoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Methyl ester group (-COOCH)₃) Primary amide (-CONH)₂) Or an aromatic amide group (-CONHAR),

R^3Aand R^3BEach independently represents a halogen atom or an alkyl group,

R⁴and R⁵Each independently represents a halogen atom, an alkyl group, a methoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Acetyl (-COCH)₃) Methyl ester group (-COOCH)₃) Or primary amide group (-CONH)₂)，

a1 and b1 represent nonnegative integers whose sum is 1 or more and 3 or less,

a2 and b2 represent nonnegative integers whose sum is 1 or more and 3 or less,

c1 and c2 represent nonnegative integers whose sum is 0 or more and 3 or less,

d and e are each independently 1 or 2.

Wherein Ar represents an aryl group having 6 to 10 carbon atoms which may have a substituent. ]

[ chemical formula 5]

General formula (2)

[ in the general formula (2), R^6AAnd R^6BEach independently represents a halogen atom, an alkyl group, an alkoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Methyl ester group (-COOCH)₃) Primary amide (-CONH)₂) Or an aromatic amide group (-CONHAR),

R⁷and R⁸Each independently represents a halogen atom, an alkyl group, a methoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Acetyl (-COCH)₃) Methyl ester group (-COOCH)₃) Or primary amide group (-CONH)₂)，

f1 and f2 represent non-negative integers whose sum is 1 or more and 3 or less,

g represents an integer of 0 to 3 inclusive,

h is 1 or 2.

Wherein Ar represents an aryl group having 6 to 10 carbon atoms which may have a substituent. ]

[ chemical formula 6]

Formula (3)

Hereinafter, the yellow toner of the present invention may be simply referred to as "toner".

Hereinafter, a method for producing yellow colored resin particles (hereinafter, sometimes simply referred to as "colored resin particles") preferably used in the present invention, yellow colored resin particles obtained by the production method, a method for producing yellow toner using the yellow colored resin particles, and the yellow toner of the present invention will be described in order.

1. Method for producing colored resin particles

In general, methods for producing colored resin particles are roughly classified into dry methods such as a pulverization method and wet methods such as an emulsion polymerization aggregation method, a suspension polymerization method, and a dissolution suspension method, and a wet method is preferable because a toner having excellent printing characteristics such as image reproducibility can be easily obtained. Among the wet methods, polymerization methods such as emulsion polymerization coagulation and suspension polymerization are preferred, and among the polymerization methods, suspension polymerization is more preferred, because toners having a small particle size distribution in the order of micrometers are easily obtained.

In the emulsion polymerization aggregation method, an emulsified polymerizable monomer is polymerized to obtain a resin fine particle emulsion, and the resin fine particle emulsion is aggregated with a colorant dispersion liquid or the like to produce colored resin particles. The above-mentioned dissolution suspension method is a method of producing colored resin particles by forming droplets from a solution in which toner components such as a binder resin and a colorant are dissolved or dispersed in an organic solvent in an aqueous medium and removing the organic solvent, and various known methods can be used.

The colored resin particles used in the present invention can be produced by a wet method or a dry method, preferably by a wet method, and particularly preferably by a suspension polymerization method among the wet methods, by the following process.

(A) Suspension polymerization process

(A-1) Process for producing polymerizable monomer composition

First, a polymerizable monomer, a yellow colorant, and further, if necessary, other additives such as a charge control agent and a release agent are mixed to prepare a polymerizable monomer composition. The mixing in the preparation of the polymerizable monomer composition is carried out using, for example, a medium-type disperser.

In the present invention, the polymerizable monomer means a monomer having a polymerizable functional group, and the polymerizable monomer is polymerized to form the binder resin. As the main component of the polymerizable monomer, a monovinyl monomer is preferably used. Examples of the monovinyl monomer include styrene; styrene derivatives such as vinyl toluene and α -methylstyrene; acrylic acid and methacrylic acid; acrylic esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and dimethylaminoethyl acrylate; methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and dimethylaminoethyl methacrylate; nitrile compounds such as acrylonitrile and methacrylonitrile; amide compounds such as acrylamide and methacrylamide; olefins such as ethylene, propylene and butylene. These monovinylic monomers can be used alone or in combination of 2 or more. Among these, as the monovinyl monomer, styrene derivatives, and derivatives of acrylic acid or methacrylic acid can be preferably used.

In order to improve the thermal offset and improve the storage stability, it is preferable to use an optional crosslinkable polymerizable monomer together with the monovinyl monomer. The crosslinkable polymerizable monomer is a monomer having 2 or more polymerizable functional groups. Examples of the crosslinkable polymerizable monomer include: aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; ester compounds in which an alcohol having 2 or more hydroxyl groups such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate is ester-bonded to 2 or more carboxylic acids; other divinyl compounds such as N, N-divinylaniline and divinyl ether; compounds having 3 or more vinyl groups, and the like. These crosslinkable polymerizable monomers may be used alone or in combination of 2 or more.

In the present invention, it is desirable to use the crosslinkable polymerizable monomer in a proportion of usually 0.1 to 5 parts by mass, preferably 0.3 to 2 parts by mass, based on 100 parts by mass of the monovinyl monomer.

Further, when a macromonomer is further used as a part of the polymerizable monomer, the balance between the storage stability and the fixability at low temperatures of the obtained toner becomes good, and therefore, it is preferable. The macromonomer is a reactive oligomer or polymer having a polymerizable carbon-carbon unsaturated double bond at the end of the molecular chain and having a number average molecular weight of usually 1000 to 30000. The macromers preferably provide the following polymers: the polymer has a Tg higher than the glass transition temperature (hereinafter sometimes referred to as "Tg") of a polymer obtained by polymerizing a monovinyl monomer. The macromonomer is preferably used in an amount of 0.03 to 5 parts by mass, more preferably 0.05 to 1 part by mass, per 100 parts by mass of the monovinyl monomer.

In the present invention, the yellow colorant contains at least any one 1 of the compound a and the compound B, and the compound C.

The compound A of the present invention is a bisazo compound represented by the following general formula (1).

[ chemical formula 7]

General formula (1)

In the above general formula (1), R^1A、R^1B、R^2AAnd R^2BEach independently represents a halogen atom, an alkyl group, an alkoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Methyl ester group (-COOCH)₃) Primary amide (-CONH)₂) Or an arylamide group (-CONHAR). Wherein Ar represents an aryl group having 6 to 10 carbon atoms which may have a substituent. R^1A、R^1B、R^2AAnd R^2BPreferably each independently represents a chlorine atom, a methyl group, a methoxy group, an amino group, a nitro group, an acetamido group, a carbomethoxy group, a primary amide group or an arylamide group. More preferably R^1AAnd R^2ARepresents a chlorine atom, a methyl group or a carbomethoxy group, R^1BAnd R^2BRepresents a carbomethoxy group, a primary amide group or an aromatic amide group. The arylamido group is preferably a phenyl group or a naphthyl group which may have a substituent, more preferably a phenyl group in which a hydrogen atom is substituted with a chlorine atom and/or an alkyl group, and still more preferably a phenyl group in which a hydrogen atom is substituted with a chlorine atom and a methyl group one by one.

R^1A、R^1B、R^2AAnd R^2BMay be added to any carbon atom on the benzene ring (except for the carbon atom on the benzene ring bonded to the azo group (-N ═ N-). R^1AAnd R^2AAddition to carbon at the ortho position relative to the carbon atom on the benzene ring bonded to the azo group (-N-) is preferred. R^1BAnd R^2BIt is preferably added to a carbon in a meta position with respect to a carbon atom on the benzene ring bonded to the azo group (-N-).

In the above general formula (1), a1 and b1 represent non-negative integers whose sum is 1 or more and 3 or less, and a2 and b2 represent non-negative integers whose sum is 1 or more and 3 or less. a1, b1, a2 and b2 are preferably all 1.

In the above general formula (1), R^3AAnd R^3BEach independently represents a halogen atom or an alkyl group. R^3AAnd R^3BMay each independently represent a chlorine atom or a methyl group.

R^3AAnd R^3BMay be added to any of the carbons on the phenyl ring (except the carbon on the phenyl ring that is bonded to the amido (-CO-NH-)).

In the general formula (1), c1 and c2 represent non-negative integers in which the sum is 0 or more and 3 or less. Further, the case where the sum of c1 and c2 is 0 means that both c1 and c2 are 0, i.e., the substituent R^3AAnd R^3BIs absent. c1 and c2 are independent of each other and may be 0 or 1.

In the above general formula (1), R⁴And R⁵Each independently represents a halogen atom, an alkyl group, a methoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Acetyl (-COCH)₃) Methyl ester group (-COOCH)₃) Or primary amide group (-CONH)₂)。R⁴And R⁵Preferably an acetyl or carbomethoxy group.

In the above general formula (1), d and e are each independently 1 or 2. d and e are preferably both 1.

Specific examples of the compound A are as follows. The compound represented by the formula (1A) is C.I. pigment yellow 155(CASNO.68516-73-4, hue angle: 95 ℃). The compound represented by the formula (1B) was C.I. pigment yellow 214(CAS No.254430-12-5, hue angle: 97 ℃). The compound represented by the formula (1C) is C.I. pigment yellow 93(CAS No.5580-57-4, hue angle: 95 ℃). The compound represented by the formula (1D) was C.I. pigment yellow 219(CAS No.347174-87-2, hue angle: 96 ℃).

[ chemical formula 8]

Formula (1A)

Formula (1B)

Formula (1C)

Formula (1D)

The compound A is not limited to the compounds represented by the above formulae (1A) to (1D). Furthermore, tautomers of the compounds represented by the above formulas (1A) to (1D) can also be preferably used as the compound a.

As the compound A, a commercially available compound or a previously synthesized compound can be used.

As a method for synthesizing the compound A, for example, a method of coupling 1 equivalent of an N, N' -1, 4-diacetylphenylenediamine derivative represented by the following general formula (a) with 2 equivalents of a benzenediazonium salt derivative represented by the following general formula (b) can be mentioned (see Japanese patent application laid-open No. 48-13692).

[ chemical formula 9]

General formula (a)

R of the general formula (a)^3A、R^3B、R⁴And R⁵R represents a group represented by the general formula (1)^3A、R^3B、R⁴Or R⁵The same groups, c1, c2, d and e of formula (a) represent the same numbers as c1, c2, d and e of formula (1).]

[ chemical formula 10]

General formula (b)

R of the general formula (b)^1A’R represents a group represented by the general formula (1)^1AOr R^2AThe same group, R of the formula (b)^1B’R represents the same as the above-mentioned R of the general formula (1)^1BOr R^2BThe same groups. Further, a1 'of the general formula (b) represents the same number as a1 or a2 of the general formula (1), and b 1' of the general formula (b) represents the same number asB1 or b2 in formula (1) are the same number.]

The compound B of the present invention is a monoazo compound represented by the following general formula (2).

[ chemical formula 11]

General formula (2)

In the above general formula (2), R^6AAnd R^6BEach independently represents a halogen atom, an alkyl group, an alkoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Methyl ester group (-COOCH)₃) Primary amide (-CONH)₂) Or an arylamide group (-CONHAR). Wherein Ar represents an aryl group having 6 to 10 carbon atoms which may have a substituent. R^6AAnd R^6BPreferably each independently represents a chlorine atom, a methyl group, a methoxy group, an amino group, a nitro group, an acetamido group, a carbomethoxy group, a primary amide group or an arylamide group. More preferably R^6ARepresents a methyl, methoxy or carbomethoxy group, R^6BRepresents a nitro group or a primary amide group.

R^6AAnd R^6BMay be added to any carbon atom on the phenyl ring (except for the carbon atom on the phenyl ring bonded to the azo group (-N ═ N-). R^6AThe addition to the carbon at the ortho position to the carbon atom on the benzene ring bonded to the azo group (-N-) is preferred. R^6BAddition to the carbon at the para-position relative to the carbon atom on the benzene ring bonded to the azo group (-N-) is preferred.

In the general formula (2), f1 and f2 represent non-negative integers whose sum is 1 to 3 inclusive. Both f1 and f2 are preferably 1.

In the above general formula (2), R⁷And R⁸Each independently represents a halogen atom, an alkyl group, a methoxy group, an amino group, a nitro group, or an acetamido group (-NHCOCH)₃) Acetyl (-COCH)₃) Methyl ester group (-COOCH)₃) Or primary amide group (-CONH)₂)。

Wherein R is⁷May represent a halogen atom or an alkyl group, or may represent a chlorine atom or a methyl group. R⁷Can be added to any carbon of the benzene ring (but with amide (-CO-)Except for the carbon on the phenyl ring to which NH-) is bonded).

Furthermore, R⁸May represent an acetyl group.

In the general formula (2), g represents an integer of 0 to 3. In addition, the case where g is 0 means that the substituent R⁷Is absent.

In the general formula (2), h is 1 or 2. h is preferably 1.

As the compound B, a commercially available compound or a previously synthesized compound can be used.

An example of the method for synthesizing the compound B is a method of coupling 1 equivalent of N-acetanilide represented by the following general formula (c) with 1 equivalent of a benzenediazonium salt derivative represented by the following general formula (d).

[ chemical formula 12]

General formula (c)

R of the general formula (c)⁷And R⁸R represents a group represented by the general formula (2)⁷Or R⁸The same groups, g and h of formula (c) represent the same numbers as g or h of formula (2).]

[ chemical formula 13]

General formula (d)

R of the general formula (d)^6AAnd R^6BR represents a group represented by the general formula (2)^6AOr R^6BThe same groups. Further, f1 and f2 of the general formula (d) represent the same number as f1 or f2 of the general formula (2).]

Specific examples of the compound B are given below. The compound represented by the formula (2A) is C.I. pigment yellow 74 (the following formula (2A), CAS No.6358-31-2, hue angle: 93-91 ℃).

[ chemical formula 14]

Formula (2A)

The compound B is not limited to the compound represented by the above formula (2A), and other c.i. pigment yellow 73, c.i. pigment yellow 75, and the like can be used as the compound B. Furthermore, tautomers of the compounds represented by the above formula (2A) can also be preferably used as the compound B.

Compound a and compound B may be yellow pigments. The yellow toner of the present invention can be improved in light resistance by using a yellow pigment together with a yellow dye (compound C) described later.

The total content of the compound a and the compound B is preferably 1 to 15 parts by mass, more preferably 3 to 13 parts by mass, further preferably 5 to 12 parts by mass, and particularly preferably 8 to 10 parts by mass, relative to 100 parts by mass of the binder resin. When the total content of the compound a and the compound B is within the above range, the reflection density, chroma, glossiness, light resistance and coloring power of the toner are further improved, and a clear image having excellent hue and transparency can be obtained. In addition, in the case where either of the compound a or the compound B is used, the "total content of the compound a and the compound B" means the content of the compound used.

In the present invention, in addition to the above-mentioned compound A and/or compound B, a compound C represented by the following formula (3) (C.I. solvent yellow 179, CAS No.54079-53-7, hue angle: 100 ℃) is contained as a yellow colorant.

[ chemical formula 15]

Formula (3)

The compound C is a yellow dye, but when combined with the compound a and/or the compound B, the compound C has an effect of improving the glossiness of the yellow toner in particular and further improving the reflection density of the yellow toner even when the toner amount is small. In this way, combining the yellow dye with another colorant (yellow pigment or the like) and thereby the yellow dye itself improves the color development characteristics of the toner, which is an unexpected effect compared to the prior art.

The content of the compound C is preferably 0.1 to 8.0 parts by mass, more preferably 0.5 to 7.0 parts by mass, and still more preferably 1.0 to 6.0 parts by mass, per 100 parts by mass of the binder resin. When the content of the compound C is within the above range, the reflection density, chroma, glossiness, light resistance and coloring power of the toner are further improved, and a vivid image having excellent color and transparency can be obtained.

In the present invention, the mass ratio of the total content of the compound a and the compound B to the content of the compound C ((compound a + compound B)/compound C) is preferably 0.1 to 10, more preferably 0.7 to 7.0, even more preferably 1.7 to 6.0, and even more preferably 2.0 to 5.0. When the mass ratio is within the above range, the reflection density, chroma, glossiness, light resistance and coloring power of the toner are further improved, and a vivid image having excellent hue and transparency can be obtained.

The total content of the compound a, the compound B and the compound C is preferably 1.0 to 23 parts by mass, more preferably 5 to 16 parts by mass, and still more preferably 8 to 13 parts by mass, relative to 100 parts by mass of the binder resin.

In the case where the total content of the compound a, the compound B, and the compound C is within the above range, the chroma and yellow color developability of the toner are further improved, and the dispersibility of the compound a in the toner is further improved. In addition, in the case where any one of the compound a or the compound B is used in combination with the compound C, "the total content of the compound a, the compound B, and the compound C" means the sum of the content of any one of the compound a or the compound B and the total content of the compound C.

The principle of the effect obtained by using the compound a and/or the compound B in combination with the compound C is not clear. However, it can be considered that: by using these compounds in combination, the presence of the compound a and/or the compound B having a specific chemical structure improves the dispersion stability of the compound C in the polymerizable monomer composition or in the binder resin, and as a result, even a small amount of the toner can exhibit higher chroma and higher gloss than those of conventional toners, and has a high reflection density and excellent light resistance. In particular, when the compound a and/or the compound B is a yellow pigment and the compound C is a yellow dye, the advantages of both the pigment and the dye can be exhibited.

As other additives, positively or negatively chargeable charge control agents can be used in order to improve the chargeability of the toner.

The charge control agent is not particularly limited as long as it is a charge control agent that can be generally used as a charge control agent for toner, but among the charge control agents, positively or negatively chargeable charge control resins are preferable from the viewpoint of improving the dispersibility of the compound a and the compound B of the present invention, having high compatibility with polymerizable monomers, and imparting stable chargeability (charge stability) to toner particles, and further, positively chargeable charge control resins are more preferably used from the viewpoint of obtaining positively chargeable toner.

Examples of the positively chargeable charge control agent include: nigrosine dyes, quaternary ammonium salts, triaminotriphenylmethane compounds, imidazole compounds, polyamine resins as charge control resins preferably used, quaternary ammonium group-containing copolymers, and the like.

Examples of the negatively chargeable charge control agent include: azo dyes containing metals such as Cr, Co, Al, and Fe, metal salicylate compounds, metal alkylsalicylate compounds, and sulfonic acid group-containing copolymers, carboxylic acid group-containing copolymers, and carboxylic acid group-containing copolymers, which are charge control resins preferably used.

In the present invention, it is desirable to use the charge control agent in a proportion of usually 0.01 to 10 parts by mass, preferably 0.03 to 8 parts by mass, relative to 100 parts by mass of the monovinyl monomer. When the amount of the charge control agent is in the range of 0.01 to 10 parts by mass, both the risk of fogging and the risk of printing stain generation are small.

In addition, as another additive, a molecular weight regulator is preferably used when polymerizing a polymerizable monomer that is polymerized to become a binder resin.

The molecular weight regulator is not particularly limited as long as it is generally used as a molecular weight regulator for toner, and examples thereof include: mercaptans such as t-dodecylmercaptan, n-octylmercaptan, and 2,2,4,6, 6-pentamethylheptane-4-mercaptan; thiuram disulfides such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, N '-dimethyl-N, N' -diphenylthiuram disulfide, and N, N '-dioctadecyl-N, N' -diisopropylthiuram disulfide. These molecular weight regulators may be used each alone or in combination of 2 or more.

In the present invention, it is desirable to use the molecular weight modifier in a proportion of usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the monovinyl monomer.

Further, as another additive, a release agent is preferably added. By adding the release agent, the releasability of the toner from the fixing roller at the time of fixing can be improved. The releasing agent is not particularly limited as long as it is generally used as a releasing agent for toner. Examples thereof include low molecular weight polyolefin waxes and modified waxes thereof; petroleum waxes such as paraffin wax; mineral waxes such as ozokerite; synthetic waxes such as Fischer-Tropsch (Fischer-Tropsch) waxes; ester waxes such as dipentaerythritol ester and carnauba wax. From the viewpoint of achieving a balance between the storage stability and the low-temperature fixing property of the toner, an ester wax is preferable, a synthetic ester wax obtained by esterifying an alcohol with a carboxylic acid is more preferable, and a synthetic ester wax in which the alcohol is a polyhydric alcohol and the carboxylic acid is a monocarboxylic acid is particularly more preferable. These may be used in 1 kind, or in combination of 2 or more kinds.

The releasing agent is preferably used in an amount of 1 to 30 parts by mass, more preferably 5 to 20 parts by mass, based on 100 parts by mass of the monovinyl monomer.

(A-2) suspension step (droplet formation step) for obtaining a suspension

In the present invention, a polymerizable monomer composition containing a polymerizable monomer and a yellow colorant is dispersed in an aqueous medium containing a dispersion stabilizer, and a polymerization initiator is added to form droplets of the polymerizable monomer composition. The method of forming the droplets is not particularly limited, and the droplet formation is carried out using a device capable of strong stirring, such as a (inline) type emulsion disperser (manufactured by Pacific Machinery & Engineering co., Ltd., trade name: mill), a high-speed emulsion disperser (manufactured by Ltd., trade name: t.k. hommizer MARK II), and the like.

Examples of the polymerization initiator include: persulfates such as potassium persulfate and ammonium persulfate; azo compounds such as 4,4 ' -azobis (4-cyanovaleric acid), 2 ' -azobis (2-methyl-N- (2-hydroxyethyl) propionamide), 2 ' -azobis (2-amidinopropane) dihydrochloride, 2 ' -azobis (2, 4-dimethylvaleronitrile), and 2,2 ' -azobisisobutyronitrile; organic peroxides such as di-t-butyl peroxide, benzoyl peroxide, t-butyl peroxy-2-ethylhexanoate, t-hexyl peroxy-2-ethylbutyrate, diisopropyl peroxydicarbonate, di-t-butyl peroxyisophthalate, and t-butyl peroxyisobutyrate. These can be used alone or in combination of 2 or more. Among these, organic peroxides are preferably used because residual polymerizable monomers can be reduced and printing durability is also excellent.

Among the organic peroxides, peroxyesters are preferred, and non-aromatic peroxyesters, i.e., peroxyesters having no aromatic ring, are more preferred, because they have good initiator efficiency and can also reduce the amount of residual polymerizable monomers.

The polymerization initiator may be added after the polymerizable monomer composition is dispersed in the aqueous medium and before the droplets are formed, or may be added to the polymerizable monomer composition before the polymerizable monomer composition is dispersed in the aqueous medium, as described above.

The amount of the polymerization initiator used for polymerization of the polymerizable monomer composition is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 15 parts by mass, and particularly preferably 1 to 10 parts by mass, based on 100 parts by mass of the monovinyl monomer.

In the present invention, an aqueous medium refers to a medium containing water as a main component.

In the present invention, the aqueous medium preferably contains a dispersion stabilizer. 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; inorganic compounds such as metal hydroxides including aluminum hydroxide, magnesium hydroxide, and iron hydroxide; water-soluble polymers such as polyvinyl alcohol, methyl cellulose and gelatin; an anionic surfactant; a nonionic surfactant; organic compounds such as amphoteric surfactants. The dispersion stabilizer can be used in 1 or 2 or more in combination.

Among the above dispersion stabilizers, inorganic compounds, particularly colloids of metal hydroxides which are hardly soluble in water, are preferred. By using an inorganic compound, particularly a colloid of a metal hydroxide which is hardly soluble in water, the particle size distribution of the colored resin particles can be narrowed, and the remaining amount of the dispersion stabilizer after washing can be reduced, so that the obtained polymerized toner can reproduce images clearly without deteriorating environmental stability.

(A-3) polymerization step

The aqueous dispersion medium obtained by forming droplets as in (A-2) above was heated to initiate polymerization, thereby forming an aqueous dispersion of colored resin particles containing a yellow colorant.

The polymerization temperature of the polymerizable monomer composition is preferably 50 ℃ or higher, and more preferably 60 to 95 ℃. The reaction time for the polymerization is preferably 1 to 20 hours, and more preferably 2 to 15 hours.

The colored resin particles can be used as they are or as a polymerized toner with an external additive added thereto, and preferably, the colored resin particles are formed into a so-called core-shell type (or also called "capsule type") colored resin particles in which the colored resin particles are used as a core layer and a shell layer different from the core layer is formed on the outer side of the core layer. The core-shell type colored resin particles can be coated with a substance having a higher softening point than a core layer formed of a substance having a low softening point, thereby achieving a balance between the reduction in the fixing temperature and the prevention of aggregation during storage.

The method for producing the core-shell type colored resin particles using the colored resin particles is not particularly limited, and the core-shell type colored resin particles can be produced by a conventionally known method. In-situ (in situ) polymerization and phase separation are preferred from the viewpoint of production efficiency.

The following describes a method for producing core-shell colored resin particles by in-situ polymerization.

The core-shell type colored resin particles can be obtained by adding a polymerizable monomer for forming the shell layer (polymerizable monomer for the shell) and a polymerization initiator to an aqueous medium in which the colored resin particles are dispersed, and polymerizing the mixture.

As the shell polymerizable monomer, the same monomers as those mentioned above can be used. Among them, monomers which can give a polymer having a Tg of more than 80 ℃ such as styrene, acrylonitrile and methyl methacrylate are preferably used singly or in combination of 2 or more.

Examples of the polymerization initiator used for polymerization of the shell polymerizable monomer include: metal persulfates such as potassium persulfate and ammonium persulfate; and water-soluble polymerization initiators such as azo initiators including 2,2 '-azobis (2-methyl-N- (2-hydroxyethyl) propionamide) and 2, 2' -azobis- (2-methyl-N- (1, 1-bis (hydroxymethyl) 2-hydroxyethyl) propionamide). These can be used alone or in combination of 2 or more. The amount of the polymerization initiator is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the shell polymerizable monomer.

The polymerization temperature of the shell layer is preferably 50 ℃ or higher, and more preferably 60 to 95 ℃. The reaction time for the polymerization is preferably 1 to 20 hours, and more preferably 2 to 15 hours.

(A-4) washing, filtration, dehydration and drying step

The aqueous dispersion of colored resin particles obtained by polymerization is preferably subjected to filtration, washing for removing the dispersion stabilizer, dehydration and drying as many times as necessary according to a conventional method after the termination of polymerization.

In the case where an inorganic compound is used as the dispersion stabilizer as the above-mentioned cleaning method, it is preferable to remove the dispersion stabilizer by dissolving the dispersion stabilizer in water by adding an acid or an alkali to the aqueous dispersion of the colored resin particles. When a colloid of an inorganic hydroxide that is hardly soluble in water is used as a dispersion stabilizer, it is preferable to adjust the pH of the aqueous dispersion of the colored resin particles to 6.5 or less by adding an acid. As the acid to be added, sulfuric acid, inorganic acids such as hydrochloric acid and nitric acid, and organic acids such as formic acid and acetic acid can be used, and sulfuric acid is particularly preferable in terms of high removal efficiency and small load on production facilities.

The method of dehydration and filtration is not particularly limited, and various known methods can be used. Examples thereof include centrifugal filtration, vacuum filtration, and pressure filtration. The method of drying is also not particularly limited, and various methods can be used.

(B) Crushing method

In the case of producing colored resin particles by the pulverization method, the following procedure is used.

First, a binder resin, a yellow colorant, and further other additives such as a charge control agent and a release agent added as needed are mixed using a Mixer, for example, a ball mill, a V-type Mixer, an FM Mixer (trade name: Nippon Coke & Engineering co., ltd., inc.), a high-speed dissolver, an internal Mixer, a Falburg, or the like. Next, the mixture obtained by the above is heated and kneaded using a pressure kneader, a twin-screw extruder, a roll, or the like. The obtained kneaded material is coarsely pulverized using a pulverizer such as a hammer mill, a chopper, a roll mill or the like. Further, the colored resin particles are finely pulverized by a pulverizer such as a jet pulverizer or a high-speed rotary pulverizer, and then classified into a desired particle size by a classifier such as an air classifier or an air classifier, thereby obtaining colored resin particles produced by the pulverization method.

The binder resin and the yellow colorant used in the pulverization method, and further, other additives such as a charge control agent and a release agent added as needed may be used as exemplified in the suspension polymerization method (a). The colored resin particles obtained by the pulverization method can be made into core-shell type colored resin particles by an in-situ polymerization method or the like, similarly to the colored resin particles obtained by the suspension polymerization method (a) described above.

As the binder resin, resins which have been widely used in toners in the past can be used. As the binder resin used in the pulverization method, specifically, polystyrene, a styrene-butyl acrylate copolymer, a polyester resin, an epoxy resin, and the like can be exemplified.

2. Colored resin particle

The colored resin particles containing a yellow colorant can be obtained by the above-mentioned production method such as the suspension polymerization method (a) or the pulverization method (B).

The colored resin particles constituting the toner will be described below. In addition, the colored resin particles described below include both core-shell type colored resin particles and non-core-shell type colored resin particles.

The volume average particle diameter (Dv) of the colored resin particles is preferably 3 to 15 μm, and more preferably 4 to 12 μm. When Dv is 3 to 15 μm, the risk of the reduction of the fluidity of the toner, the deterioration of the transferability, the reduction of the image density, and the reduction of the resolution of the image is small.

The ratio (Dv/Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of the colored resin particles is preferably 1.0 to 1.3, and more preferably 1.0 to 1.2. When Dv/Dn is 1.0 to 1.3, the risk of occurrence of a decrease in transferability, image density, and resolution is small. The volume average particle diameter and the number average particle diameter of the colored resin particles can be measured using, for example, a particle size analyzer (BECKMAN COULTER co., ltd., product name: Multisizer).

From the viewpoint of image reproducibility, the average circularity of the colored resin particles of the present invention is preferably 0.96 to 1.00, more preferably 0.97 to 1.00, and even more preferably 0.98 to 1.00.

When the average circularity of the colored resin particles is 0.96 to 1.00, the printed fine line reproducibility is excellent.

The toner of the present invention can be obtained by directly using the colored resin particles containing the yellow colorant as a toner, but from the viewpoint of adjusting the chargeability, fluidity, storage stability, and the like of the toner, the colored resin particles may be mixed and stirred with an external additive to be subjected to an external addition treatment, whereby the external additive is attached to the surface of the colored resin particles to prepare a one-component toner.

Further, the one-component toner may be further mixed and stirred with carrier particles to prepare a 2-component developer.

The stirrer to be subjected to the external addition treatment is not particularly limited as long as it is a stirring device capable of adhering the external additive to the surface of the colored resin particles, and for example, FM Mixer (trade name, Nippon Coke & Engineering co., lttd., ltd.) or Super Mixer (trade name, product of kayowa corporation) can be used

Manufactured by Nippon Coke & Engineering co., ltd., manufactured by ltd.), a mechanofusion system (manufactured by HOSOKAWA MICRON CORPORATION), and a mechanomil (manufactured by okada seikagaku CORPORATION) capable of mixing and stirring.

Examples of the external additive include: inorganic fine particles containing silica, titanium dioxide, alumina, zinc oxide, tin oxide, calcium carbonate, calcium phosphate, cerium oxide, and/or the like; organic fine particles containing polymethyl methacrylate resin, silicone resin, melamine resin, and the like. Among these, inorganic fine particles are preferable, and among the inorganic fine particles, silica and/or titania are preferable, and silica-containing fine particles are particularly preferable.

These external additives may be used alone, but it is preferable to use 2 or more kinds in combination.

In the present invention, it is desirable to use the external additive in a proportion of usually 0.05 to 6 parts by mass, preferably 0.2 to 5 parts by mass, relative to 100 parts by mass of the colored resin particles. When the amount of the external additive is 0.05 to 6 parts by mass, transfer residue and fogging are reduced.

4. Toner of the present invention

The toner of the present invention obtained by using the compound a and/or the compound B in combination with the compound C as a yellow colorant through the above-described steps is a yellow color modifier having higher glossiness, reflection density and chroma than conventional toners and excellent light resistance even when the toner amount is small.