JP2007025038A - Electrophotographic black toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic black toner using a dye with good dispersion stability, exhibiting a high blackening degree, excellent in transparency and light resistance, and excellent also in heat resistance, charging property, offset resistance and thin line reproducibility. <P>SOLUTION: The electrophotographic black toner is obtained by fusion-bonding resin particles and colorant-containing resin particles at least in an aqueous medium, wherein the colorant contained in the colorant-containing resin particles contains at least one oil-soluble dye represented by the formula (1): A-(N=N-B<SB>m</SB>)<SB>n</SB>-N=N-C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a black toner for electrophotography containing a novel dye.

  As a method for producing toner used in electrophotography, conventionally, a coloring agent and other additives used as necessary are added to a thermoplastic resin as a binder, and these are melt-kneaded and then pulverized and classified. So-called pulverization methods for producing toner are known. In this pulverization method, it is practically difficult to produce a toner having a small particle diameter of, for example, a volume average particle diameter of about 1 to 5 μm, for example, for preventing generation of fine powder due to brittle fracture of the resin. The volume average particle size is about 10 μm. However, such a toner having a large particle size cannot meet the recent demand for higher image quality, and has a problem of poor fine line reproducibility.

  Under such circumstances, in recent years, a method for producing a toner by a suspension polymerization method has been proposed. For example, a technique using a nigrosine dye has been proposed in order to enhance the dispersibility of carbon black in a polymerizable monomer when a toner is produced by a suspension polymerization method (see Patent Document 1). In addition, a technique using hydrophobic carbon black has been proposed in order to improve the dispersibility of carbon black with respect to a polymerizable monomer when a toner is produced by a suspension polymerization method (see Patent Document 2).

  Recent copiers and printers are becoming increasingly demanding in terms of size reduction, weight reduction and high reliability, and demands on toner performance are becoming strict. The blackness of the toner is also a major factor that determines the image quality. In general, the blackness of the toner depends on the colorant used, for example, a magnetic material or carbon black. In the above-described polymerization toner, the carbon black is uniformly contained in the polymerizable monomer. It is difficult to reduce the particle size and disperse, for example, there is a problem that carbon black is liberated and particles of resin only are formed, and as a result, the degree of blackening is low.

  Therefore, a technique using a carbon black dispersion aid or a hydrophobic carbon black has been proposed (see Patent Documents 3 and 4), but it is not yet satisfactory and an improvement is desired. There is a need for improved or alternative black pigment development.

  In addition, toners using pigments other than carbon black include those in which blue pigments, yellow pigments, and red pigments are mixed (see Patent Document 5) and toners in which azomethine black organic pigments are used (see Patent Document 6). The color tone and the triboelectric chargeability are not satisfactory, and improvements are desired.

Besides the toner, non-heterocyclic compounds such as phenol and naphthol are widely used as black dyes as disazo dyes and trisazo dyes as raw materials, and disazo dyes obtained from these are also known (see Patent Document 7). ). On the other hand, disazo dyes containing two or more heterocycles, disperse dyes and reactive dyes for dyeing fibers as trisazo dyes are known (see Patent Document 8). In addition to these disazo dyes, disazo dyes containing two or more heterocycles for toners are also known (see Patent Document 9), but there is no description of fine line reproducibility and further improvements are desired. Yes.
JP-A-1-145664 JP 60-117253 A JP-A-5-70511 JP 60-117253 A JP-A-5-27481 JP 2003-316072 A European Patent No. 0761771 JP 59-133259 A JP 2004-231945 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a black toner for electrophotography having a high degree of blackening using a dye having good dispersion stability. Furthermore, it is an object of the present invention to provide an electrophotographic toner excellent in transparency and light resistance, and excellent in heat resistance, chargeability, offset resistance and fine line reproducibility.

  The above object of the present invention can be achieved by the following constitution.

(Claim 1)
In a black toner for electrophotography obtained by fusing resin particles and colorant-containing resin particles at least in an aqueous medium, the colorant contained in the colorant-containing resin particles is represented by the following general formula (1). A black toner for electrophotography, comprising at least one oil-soluble dye.

General formula (1)
A- (N = N- _Bm ) _n- N = N-C
[Wherein, A, B and C each independently represent an optionally substituted aromatic group or heterocyclic group, at least one represents a heterocyclic group, and m and n are 1 or 2; is there. ]
(Claim 2)
The black toner for electrophotography according to claim 1, wherein the oil-soluble dye represented by the general formula (1) is represented by the following general formula (2).

[Wherein, A and B each independently represents an optionally substituted aromatic group or heterocyclic group, and B ₁ and B ₂ each represent ═CR ₁ — and —CR ₂ ═, Or one of them represents a nitrogen atom and the other represents = CR ₁ -or -CR ₂ =. G, R ₁ and R ₂ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, heterocyclic oxy Carbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (anilino group, heterocyclic ring) Amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, nitro group, alkyl or arylthio group, Heterocycle It represents a thio group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, and each group may be further substituted. R ₅ and R ₆ each independently represents a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group or sulfamoyl group. Each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. R ₁ and R ₅ , or R ₅ and R ₆ may be bonded to form a 5- to 6-membered ring. ]
(Claim 3)
The black toner for electrophotography according to claim 1, wherein the oil-soluble dye represented by the general formula (1) is represented by the following general formula (3).

[Wherein, A represents an optionally substituted aromatic group or heterocyclic group, and B ₁ and B ₂ each represent ═CR ₁ — and —CR ₂ ═, or one of them represents The nitrogen atom and the other represents = CR ₁ -or -CR ₂ =. G, R ₁ , R ₂ , R ₇ and R ₈ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carbamoyl group, alkoxycarbonyl group, aryloxy Carbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (Including anilino group and heterocyclic amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, nitro group , Alkyl or arylthio Represents an o group, a heterocyclic thio group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, and each group may be further substituted. R ₅ and R ₆ each independently represents a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group or sulfamoyl group. Each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. R ₁ and R ₅ , or R ₅ and R ₆ may be bonded to form a 5- to 6-membered ring. ]
(Claim 4)
The black toner for electrophotography according to claim 1, wherein the oil-soluble dye represented by the general formula (1) is represented by the following general formula (5).

[Wherein, A represents an optionally substituted aromatic group or heterocyclic group, and R ₁ and R ₂ each independently represents a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a hetero group, Ring group, cyano group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy Group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (including anilino group and heterocyclic amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, Alkyl or arylsulfonylamino group, heterocyclic sulfoni Represents a ruamino group, a nitro group, an alkyl or arylthio group, a heterocyclic thio group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, and each group is further substituted. May be. R ₃ and R ₄ are each independently a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group, or sulfamoyl group Represents. R ₅ and R ₆ each independently represents a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group or sulfamoyl group. Each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. R ₁ and R ₅ , or R ₅ and R ₆ may be bonded to form a 5- to 6-membered ring. Z ₁ represents an electron-withdrawing group having a Hammett's substituent constant σp value of 0.20 or more. ]
(Claim 5)
The oil-soluble dye A represented by the general formulas (1) to (3) or (5) is represented by the following general formulas (Cp-1) to (Cp-9). The black toner for electrophotography of any one of -4.

[Wherein, R _{20 to} R ₃₅ represent a hydrogen atom or a substituent, and are bonded to an azo group at the * mark. ]
(Claim 6)
At least one oil-soluble dye represented by the general formulas (1) to (3) or (5) and at least one yellow dye represented by the following general formulas (Y-1) to (Y-10) The black toner for electrophotography according to any one of claims 1 to 5, comprising:

[Wherein R ₄₁ , R ₄₂ , R ₄₂ ′ R ₄₄ , R ₄₈ and R ₄₈ ′ are each independently hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carbamoyl. Group, alkoxycarbonyl group, aryloxycarbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, Aryloxycarbonyloxy group, amino group (including anilino group and heterocyclic amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, Heterocyclic sulfonylamino group, nitro group, alkyl And arylthio groups, heterocyclic thio group, an alkyl- or arylsulfonyl group, heterocyclic sulfonyl group, an alkyl- or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, may each group further substituted. R ₄₃ represents an aliphatic group, and R ₄₇ , R ₄₇ ′ and R ₄₉ represent an aliphatic group, an aromatic group, a heterocyclic group or an acyl group. W represents —OH or —NR ₄₅ R ₄₆ . R ₄₅ , R ₄₆ , R ₄₅ ′ and R ₄₆ ′ are each independently a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or It represents an arylsulfonyl group or a sulfamoyl group, and each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. p represents an integer of 0 to 5, q represents an integer of 0 to 2, and r represents an integer of 0 to 4. ]
(Claim 7)
In an electrophotographic toner comprising a thermoplastic resin in which colored fine particles containing a resin having a composition different from that of the thermoplastic resin and a colorant are dispersed, the colorant is represented by the general formulas (1) to ( The black toner for electrophotography according to claim 1, comprising at least one oil-soluble dye represented by 3) or (5).

  According to the present invention, it is possible to provide a black toner for electrophotography having a high degree of blackening using a dye having good dispersion stability. Moreover, it is possible to provide an electrophotographic toner that is excellent in transparency and light resistance, and excellent in heat resistance, chargeability, offset resistance and fine line reproducibility.

  Hereinafter, although the best mode for carrying out the present invention will be described, the present invention is not limited to these.

  Hereinafter, the present invention will be described in detail.

  As a result of intensive studies to solve the above problems, the present inventors have described the oils represented by the general formulas (1) to (3) or (5) described in claims 1 to 7, respectively. It has been found that a black toner using a dye having a specific structure as represented by a soluble dye exhibits an excellent degree of blackening.

  Hereinafter, the oil-soluble dye represented by the general formula (1) to (3) or (5) (hereinafter, the dye represented by the general formula (1) to (3) or (5), or the general formula ( The compound represented by 1) to (3) or (5) is also described.

  In the general formula (1), A, B and C each independently represent an optionally substituted aromatic group or heterocyclic group. m and n are 1 or 2.

  The pigment (azo dye) represented by the general formula (1) is particularly preferably the pigment (dye) represented by the general formula (2).

In the general formula (2), B ₁ and B ₂ each represent = CR ₁ -and -CR ₂ =, or either one represents a nitrogen atom and the other represents = CR ₁ -or -CR ₂ =. . G, R ₁ and R ₂ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, heterocyclic oxy Carbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (anilino group, heterocyclic ring) Amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, nitro group, alkyl and arylthio group, Heterocyclic thio Represents a group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, and each group may be further substituted.

R ₅ and R ₆ each independently represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkyl or arylsulfonyl group, or a sulfamoyl group. Each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. R ₁ and R ₅ , or R ₅ and R ₆ may be bonded to form a 5- to 6-membered ring.

  The pigment (azo dye) represented by the general formula (2) is preferably a pigment (dye) represented by the general formula (3).

In Formula (3), R ₇ and R ₈ has the same meaning as R ₁ in formula (2). Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. An aliphatic group means an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an aralkyl group, and a substituted aralkyl group. The aliphatic group may have a branch and may form a ring. The number of carbon atoms in the aliphatic group is preferably 1-20, and more preferably 1-16. The aryl part of the aralkyl group and the substituted aralkyl group is preferably phenyl or naphthyl, particularly preferably phenyl. Examples of aliphatic groups are methyl, ethyl, butyl, isopropyl, t-butyl, hydroxyethyl, methoxyethyl, cyanoethyl, trifluoromethyl, 3-sulfopropyl, 4-sulfobutyl, cyclohexyl, benzyl, 2-phenethyl, vinyl And each group such as allyl.

  As an aromatic group, a monovalent aromatic group means an aryl group and a substituted aryl group. The aryl group is preferably a phenyl group or a naphthyl group, and particularly preferably a phenyl group. The monovalent aromatic group preferably has 6 to 20 carbon atoms, more preferably 6 to 16. Examples of the monovalent aromatic group include groups such as phenyl, p-tolyl, p-methoxyphenyl, o-chlorophenyl, m- (3-sulfopropylamino) phenyl and the like. The divalent aromatic group is a divalent version of these monovalent aromatic groups. Examples thereof include phenylene, p-tolylene, p-methoxyphenylene, o-chlorophenylene, and m- (3 -Sulfopropylamino) phenylene, naphthylene and the like.

  The heterocyclic group includes a heterocyclic group having a substituent and an unsubstituted heterocyclic group. The heterocyclic ring may be condensed with an aliphatic ring, an aromatic ring or another heterocyclic ring. As the heterocyclic group, a 5- or 6-membered heterocyclic group is preferable, and N, O, and S can be exemplified as the hetero atom of the heterocyclic ring. Examples of the substituent include an aliphatic group, a halogen atom, an alkyl or arylsulfonyl group, an acyl group, an acylamino group, a sulfamoyl group, a carbamoyl group, and the like. Examples of the heterocyclic group include 2-pyridyl group, 2-thienyl group, 2-thiazolyl group, 2-benzothiazolyl group, 2-benzoxazolyl group and 2-furyl group.

  The carbamoyl group includes a carbamoyl group having a substituent and an unsubstituted carbamoyl group. Examples of the substituent include an alkyl group. Examples of the carbamoyl group include a methylcarbamoyl group and a dimethylcarbamoyl group.

  The alkoxycarbonyl group includes an alkoxycarbonyl group having a substituent and an unsubstituted alkoxycarbonyl group. As the alkoxycarbonyl group, an alkoxycarbonyl group having 2 to 20 carbon atoms is preferable. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

  The aryloxycarbonyl group includes an aryloxycarbonyl group having a substituent and an unsubstituted aryloxycarbonyl group. As the aryloxycarbonyl group, an aryloxycarbonyl group having 7 to 20 carbon atoms is preferable. Examples of the aryloxycarbonyl group include a phenoxycarbonyl group.

  The heterocyclic oxycarbonyl group includes a heterocyclic oxycarbonyl group having a substituent and an unsubstituted heterocyclic oxycarbonyl group. The heterocyclic oxycarbonyl group is preferably a heterocyclic oxycarbonyl group having 2 to 20 carbon atoms. Examples of the heterocyclic oxycarbonyl group include a 2-pyridyloxycarbonyl group.

  The acyl group includes an acyl group having a substituent and an unsubstituted acyl group. The acyl group is preferably an acyl group having 1 to 20 carbon atoms. Examples of the acyl group include an acetyl group and a benzoyl group.

  The alkoxy group includes an alkoxy group having a substituent and an unsubstituted alkoxy group. As an alkoxy group, a C1-C20 alkoxy group is preferable. Examples of the substituent include an alkoxy group and a hydroxyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, a methoxyethoxy group, a hydroxyethoxy group, and a 3-carboxypropoxy group.

  The aryloxy group includes an aryloxy group having a substituent and an unsubstituted aryloxy group. The aryloxy group is preferably an aryloxy group having 6 to 20 carbon atoms. Examples of the substituent include an alkoxy group. Examples of the aryloxy group include a phenoxy group, a p-methoxyphenoxy group, and an o-methoxyphenoxy group.

  The heterocyclic oxy group includes a heterocyclic oxy group having a substituent and an unsubstituted heterocyclic oxy group. The heterocyclic oxy group is preferably a heterocyclic oxy group having 2 to 20 carbon atoms. Examples of the substituent include an alkyl group and an alkoxy group. Examples of the heterocyclic oxy group include a 3-pyridyloxy group and a 3-thienyloxy group.

  The silyloxy group is preferably a silyloxy group substituted with an aliphatic group or aromatic group having 1 to 20 carbon atoms. Examples of the silyloxy group include a trimethylsilyloxy group and a diphenylmethylsilyloxy group.

  The acyloxy group includes an acyloxy group having a substituent and an unsubstituted acyloxy group. As the acyloxy group, an acyloxy group having 1 to 20 carbon atoms is preferable. Examples of the acyloxy group include an acetoxy group and a benzoyloxy group.

  The carbamoyloxy group includes a carbamoyloxy group having a substituent and an unsubstituted carbamoyloxy group. Examples of the substituent include an alkyl group. Examples of the carbamoyloxy group include an N-methylcarbamoyloxy group.

  The alkoxycarbonyloxy group includes an alkoxycarbonyloxy group having a substituent and an unsubstituted alkoxycarbonyloxy group. As the alkoxycarbonyloxy group, an alkoxycarbonyloxy group having 2 to 20 carbon atoms is preferable. Examples of the alkoxycarbonyloxy group include a methoxycarbonyloxy group and an isopropoxycarbonyloxy group.

  The aryloxycarbonyloxy group includes an aryloxycarbonyloxy group having a substituent and an unsubstituted aryloxycarbonyloxy group. The aryloxycarbonyloxy group is preferably an aryloxycarbonyloxy group having 7 to 20 carbon atoms. Examples of the aryloxycarbonyloxy group include a phenoxycarbonyloxy group.

  The amino group includes an amino group substituted with an alkyl group, an aryl group or a heterocyclic group, and the alkyl group, aryl group and heterocyclic group may further have a substituent. As the alkylamino group, an alkylamino group having 1 to 20 carbon atoms is preferable. Examples of the alkylamino group include a methylamino group and a diethylamino group.

  The arylamino group includes an arylamino group having a substituent, an unsubstituted arylamino group, and an anilino group. The arylamino group is preferably an arylamino group having 6 to 20 carbon atoms. Examples of the substituent include a halogen atom. Examples of the arylamino group include a phenylamino group and a 2-chlorophenylamino group.

  The heterocyclic amino group includes a heterocyclic amino group having a substituent and an unsubstituted heterocyclic amino group. As the heterocyclic amino group, a heterocyclic amino group having 2 to 20 carbon atoms is preferable. Examples of the substituent include an alkyl group and a halogen atom.

  The acylamino group includes an acylamino group having a substituent and an unsubstituted acylamino group. The acylamino group is preferably an acylamino group having 2 to 20 carbon atoms. Examples of the acylamino group include an acetylamino group, a propionylamino group, a benzoylamino group, an N-phenylacetylamino group, and a 3,5-disulfobenzoylamino group.

  The ureido group includes a ureido group having a substituent and an unsubstituted ureido group. The ureido group is preferably a ureido group having 1 to 20 carbon atoms. Examples of the substituent include an alkyl group and an aryl group. Examples of the ureido group include a 3-methylureido group, a 3,3-dimethylureido group, and a 3-phenylureido group.

  The sulfamoylamino group includes a sulfamoylamino group having a substituent and an unsubstituted sulfamoylamino group. Examples of the substituent include an alkyl group. Examples of the sulfamoylamino group include an N, N-dipropylsulfamoylamino group.

  The alkoxycarbonylamino group includes an alkoxycarbonylamino group having a substituent and an unsubstituted alkoxycarbonylamino group. As the alkoxycarbonylamino group, an alkoxycarbonylamino group having 2 to 20 carbon atoms is preferable. Examples of the alkoxycarbonylamino group include an ethoxycarbonylamino group.

  The aryloxycarbonylamino group includes an aryloxycarbonylamino group having a substituent and an unsubstituted aryloxycarbonylamino group. The aryloxycarbonylamino group is preferably an aryloxycarbonylamino group having 7 to 20 carbon atoms. Examples of the aryloxycarbonylamino group include a phenoxycarbonylamino group.

  The alkyl and arylsulfonylamino groups include substituted alkyl and arylsulfonylamino groups, and unsubstituted alkyl and arylsulfonylamino groups. As the sulfonylamino group, a sulfonylamino group having 1 to 20 carbon atoms is preferable. Examples of these sulfonylamino groups include a methylsulfonylamino group, an N-phenyl-methylsulfonylamino group, a phenylsulfonylamino group, and a 3-carboxyphenylsulfonylamino group.

  The heterocyclic sulfonylamino group includes a heterocyclic sulfonylamino group having a substituent and an unsubstituted heterocyclic sulfonylamino group. The heterocyclic sulfonylamino group is preferably a heterocyclic sulfonylamino group having 1 to 12 carbon atoms. Examples of the heterocyclic sulfonylamino group include a 2-thiophenesulfonylamino group and a 3-pyridinesulfonylamino group.

  The heterocyclic sulfinyl group includes a heterocyclic sulfinyl group having a substituent and an unsubstituted heterocyclic sulfinyl group. The heterocyclic sulfinyl group is preferably a heterocyclic sulfinyl group having 1 to 20 carbon atoms. Examples of the heterocyclic sulfinyl group include a 4-pyridinesulfinyl group.

  The alkyl, aryl or heterocyclic thio group includes an alkyl, aryl or heterocyclic thio group having a substituent and an unsubstituted alkyl, aryl or heterocyclic thio group. As the alkyl, aryl or heterocyclic thio group, those having 1 to 20 carbon atoms are preferable. Examples of the alkyl, aryl or heterocyclic thio group include a methylthio group, a phenylthio group, and a 2-pyridylthio group.

  The alkyl or arylsulfonyl group includes an alkyl or arylsulfonyl group having a substituent and an unsubstituted alkyl or arylsulfonyl group. Examples of the alkyl or arylsulfonyl group include a methylsulfonyl group and a phenylsulfonyl group, respectively.

  The heterocyclic sulfonyl group includes a heterocyclic sulfonyl group having a substituent and an unsubstituted heterocyclic sulfonyl group. The heterocyclic sulfonyl group is preferably a heterocyclic sulfonyl group having 1 to 20 carbon atoms. Examples of the heterocyclic sulfonyl group include a 2-thiophenesulfonyl group and a 3-pyridinesulfonyl group.

  The alkyl or arylsulfinyl group includes a substituted alkyl or arylsulfinyl group, an unsubstituted alkyl or arylsulfinyl group. Examples of the alkyl or arylsulfinyl group include a methylsulfinyl group and a phenylsulfinyl group, respectively.

  The sulfamoyl group includes a sulfamoyl group having a substituent and an unsubstituted sulfamoyl group. Examples of the substituent include an alkyl group. Examples of the sulfamoyl group include a dimethylsulfamoyl group and a di- (2-hydroxyethyl) sulfamoyl group.

  Next, the general formulas (1), (2), and (3) will be described in more detail. However, in the following description, the above description is applied to groups and substituents.

  In the general formula (1), A, B and C are each independently an optionally substituted aromatic group (A and C are monovalent aromatic groups such as aryl groups; B is a divalent aromatic group) A group such as an arylene group) or an optionally substituted heterocyclic group (A and C are monovalent heterocyclic groups; B is a divalent heterocyclic group). Examples of the aromatic ring include a benzene ring and a naphthalene ring, and examples of the hetero atom of the heterocyclic ring include N, O, and S. The heterocyclic ring may be condensed with an aliphatic ring, an aromatic ring or another heterocyclic ring. The substituent may be an arylazo group or a heterocyclic azo group. Moreover, at least two of A, B, and C are preferably heterocyclic rings.

  A preferable heterocyclic group for C includes an aromatic nitrogen-containing 6-membered heterocyclic group represented by the following general formula (4). When C is an aromatic nitrogen-containing 6-membered heterocyclic group represented by the following general formula (4), the general formula (1) corresponds to the general formula (2).

In the general formula (4), B ₁ and B ₂ each represent = CR ₁ -and -CR ₂ =, or either one represents a nitrogen atom and the other represents = CR ₁ -or -CR ₂ =. More preferably, each represents = CR _1- , -CR ₂ =. R ₅ and R ₆ are each independently a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group or sulfamoyl group. Each group may further have a substituent. Preferable substituents represented by R ₅ and R ₆ include a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkyl or arylsulfonyl group. More preferred are a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an alkyl or arylsulfonyl group. Most preferably, they are a hydrogen atom, an aliphatic group, and an aromatic group. Each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms.

G, R ₁ and R ₂ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carboxyl group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, Heterocyclic oxycarbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (anilino group) A heterocyclic amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, nitro group, alkyl or Arylthio , A heterocyclic thio group, an alkyl- or arylsulfonyl group, heterocyclic sulfonyl group, an alkyl- or arylsulfinyl group, heterocyclic sulfinyl group, a sulfamoyl group or a sulfo group, and each group may be further substituted.

  Examples of the substituent represented by G include a hydrogen atom, halogen atom, aliphatic group, aromatic group, hydroxy group, alkoxy group, aryloxy group, acyloxy group, heterocyclic oxy group, amino group (anilino group, heterocyclic ring). (Including amino groups), acylamino groups, ureido groups, sulfamoylamino groups, alkoxycarbonylamino groups, aryloxycarbonylamino groups, alkyl or arylthio groups, or heterocyclic thio groups, more preferably hydrogen atoms or halogen atoms. , An alkyl group, a hydroxy group, an alkoxy group, an aryloxy group, an acyloxy group, an amino group (including an anilino group and a heterocyclic amino group) or an acylamino group, among which a hydrogen atom, an anilino group and an acylamino group are most preferable. Each group may further have a substituent.

Preferable substituents represented by R ₁ and R ₂ include a hydrogen atom, an alkyl group, a halogen atom, an alkoxycarbonyl group, a carbamoyl group, a hydroxy group, an alkoxy group, and a cyano group. Each group may further have a substituent. R ₁ and R ₅ , or R ₅ and R ₆ may combine to form a 5- to 6-membered ring. Examples of the substituent in the case where each of the substituents represented by R ₁ , R ₂ , R ₅ , R ₆ and G further has a substituent include the substituents mentioned in the above G, R ₁ and R _2. it can.

  Preferred heterocycles when B is a ring structure include thiophene rings, thiazole rings, imidazole rings, benzothiazole rings, and thienothiazole rings. Each heterocyclic group may further have a substituent. Of these, thiophene rings, thiazole rings, imidazole rings, benzothiazole rings, and thienothiazole rings represented by the following general formulas (a) to (e) are preferable. In addition, when B is a thiophene ring represented by (a) and C is a structure represented by the general formula (4), the general formula (1) corresponds to the general formula (3). Become.

In the general formulas (a) to (e), R ₉ to R ₁₇ represent a substituent having the same meaning as G, R ₁ and R ₂ in the general formula (2).

  In the present invention, a particularly preferred structure is represented by the general formula (5).

In the general formula (5), Z ₁ represents an electron-withdrawing group having a Hammett's substituent constant σp value of 0.20 or more. Z ₁ is preferably an electron-withdrawing group having a σp value of 0.30 or more, more preferably an electron-withdrawing group of 0.45 or more, and particularly preferably an electron-withdrawing group of 0.60 or more. It is desirable not to exceed 0.0. Specific examples of the preferred substituent include an electron-withdrawing substituent described later. Among them, an acyl group having 2 to 20 carbon atoms, an alkyloxycarbonyl group having 2 to 20 carbon atoms, a nitro group, a cyano group, An alkylsulfonyl group having 1 to 20 carbon atoms, an arylsulfonyl group having 6 to 20 carbon atoms, a carbamoyl group having 1 to 20 carbon atoms, and a halogenated alkyl group having 1 to 20 carbon atoms are preferable. Particularly preferred are a cyano group, an alkylsulfonyl group having 1 to 20 carbon atoms, and an arylsulfonyl group having 6 to 20 carbon atoms, and most preferred is a cyano group.

R ₁ , R ₂ , R ₅ , and R ₆ have the same meaning as in general formula (2). R ₃ and R ₄ are each independently a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group, or sulfamoyl group. Represents. Among these, a hydrogen atom, an aromatic group, a heterocyclic group, an acyl group, an alkyl or arylsulfonyl group is preferable, and a hydrogen atom, an aromatic group, and a heterocyclic group are particularly preferable.

Each group described in the general formula (5) may further have a substituent. When each of these groups further has a substituent, examples of the substituent include the substituents described in the general formula (2) and the groups exemplified for G, R ₁ and R ₂ . Here, Hammett's substituent constant σp value used in this specification will be described. Hammett's rule was found in 1935 by L. L. in order to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. Substituent constants determined by Hammett's rule include a σp value and a σm value, and these values can be found in many general books. A. Dean, “Lange's Handbook of Chemistry”, 12th edition, 1979 (Mc Graw-Hill) and “Chemicals” special edition, 122, 96-103, 1979 (Nankodo). In the present invention, each substituent is limited or explained by Hammett's substituent constant σp, which means that it can be found in the above-mentioned book and is limited only to a substituent having a known value in the literature. However, it goes without saying that even if the value is unknown, it also includes a substituent that would be included in the range when measured based on Hammett's rule. In addition, the general formula (1) or (2) of the present invention includes those that are not benzene derivatives, but the σp value is used as a scale indicating the electronic effect of the substituent regardless of the substitution position. In the present invention, the σp value is used in this sense.

  Examples of the electron-withdrawing group having a Hammett substituent constant σp value of 0.60 or more include a cyano group, a nitro group, an alkylsulfonyl group (for example, methanesulfonyl group), and an arylsulfonyl group (for example, benzenesulfonyl group). it can. Examples of the electron-withdrawing group having a Hammett σp value of 0.45 or more include an acyl group (for example, acetyl group), an alkoxycarbonyl group (for example, dodecyloxycarbonyl group), an aryloxycarbonyl group (for example, m-chlorophenoxycarbonyl) in addition to the above. ), An alkylsulfinyl group (for example, n-propylsulfinyl), an arylsulfinyl group (for example, phenylsulfinyl), a sulfamoyl group (for example, N-ethylsulfamoyl, N, N-dimethylsulfamoyl), a halogenated alkyl group ( For example, trifluoromethyl) can be mentioned. As the electron-withdrawing group having a Hammett substituent constant σp value of 0.30 or more, in addition to the above, an acyloxy group (for example, acetoxy), a carbamoyl group (for example, N-ethylcarbamoyl, N, N-dibutylcarbamoyl), halogen Alkoxy group (for example, trifluoromethyloxy), halogenated aryloxy group (for example, pentafluorophenyloxy), sulfonyloxy group (for example, methylsulfonyloxy group), halogenated alkylthio group (for example, difluoromethylthio), 2 An aryl group (eg, 2,4-dinitrophenyl, pentachlorophenyl) substituted with one or more electron-withdrawing groups having a σp value of 0.15 or more, and a heterocycle (eg, 2-benzoxazolyl, 2- Benzothiazolyl, 1-phenyl-2-benzimidazolyl) be able to. Specific examples of the electron-withdrawing group having a σp value of 0.20 or more include a halogen atom in addition to the above.

A particularly preferred combination of substituents as the dye (azo dye) represented by the general formula (3) is preferably a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a sulfonyl group, or acyl as R ₅ and R _6. More preferably a hydrogen atom, an aryl group, a heterocyclic group or a sulfonyl group, and most preferably a hydrogen atom, an aryl group or a heterocyclic group. However, R ₅ and R ₆ are not both hydrogen atoms. G is preferably a hydrogen atom, a halogen atom, an alkyl group, a hydroxyl group, an amino group, or an acylamino group, more preferably a hydrogen atom, a halogen atom, an amino group, or an acylamino group, most preferably a hydrogen atom, an amino group. Group, an acylamino group. Among A, a pyrazole ring, an imidazole ring, an isothiazole ring, a thiadiazole ring, a benzothiazole ring and the like are preferable, but will be described in more detail later. B ₁ and B ₂ are preferably ═CR ₁ — and —CR ₂ ═, and R ₁ and R ₂ are preferably a hydrogen atom, an alkyl group, a halogen atom, a cyano group, a carbamoyl group, a hydroxyl group, an alkoxy group, respectively. Group, an alkoxycarbonyl group, and more preferably a hydrogen atom, an alkyl group, a cyano group, and a carbamoyl group.

  In the general formulas (1) to (3) or (5), the heterocyclic ring represented by A is preferably the above general formulas (Cp-1) to (Cp-9) in addition to the above.

In the general formulas (Cp-1) to (Cp-9), R _{20 to} R ₃₅ represent a hydrogen atom or a substituent.

In the formula, the substituent represented by R _{20 to} R ₃₅ is not particularly limited as long as it can be substituted, but a halogen atom, an alkyl group (an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, Butyl group, isopropyl group, t-butyl group, hydroxyethyl group, methoxyethyl group, cyanoethyl group, trifluoromethyl group, 3-sulfopropyl group, 4-sulfobutyl group, etc.), cycloalkyl group (for example, cyclohexyl group, cyclopentyl group) Etc.), aralkyl group (eg benzyl group, 2-phenethyl group etc.), aryl group (eg phenyl group, p-tolyl group, p-methoxyphenyl group, o-chlorophenyl group, m- (3-sulfopropylamino) phenyl) Group), a heterocyclic group (for example, 2-pyridyl group, 2-thienyl group, 2-furyl group, etc.), an alkoxy group (having 1 to 12 carbon atoms). Alkoxy groups such as methoxy group, ethoxy group, isopropoxy group, methoxyethoxy group, hydroxyethoxy group, 3-carboxypropoxy group, etc.), aryloxy groups (eg phenoxy group, p-methoxyphenyl group, o-methoxyphenoxy group, etc.) ), Acylamino groups (eg acetylamino group, propionylamino group, benzoylamino group, 3,5-disulfobenzoylamino group etc.), sulfonylamino groups (eg methanesulfonylamino group, benzenesulfonylamino group, 3-carboxybenzenesulfonyl) Amino group etc.), ureido group (eg 3-methylureido group, 3,3-dimethylureido group, 3-phenylureido group etc.), alkoxycarbonylamino group (eg ethoxycarbonylamino group etc.), alkylthio group (eg methyl) Thio group, ethylthio group, etc.), arylthio group (eg, phenylthio group, p-tolylthio group, etc.), alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, etc.), carbamoyl group (eg, methylcarbamoyl group, dimethylcarbamoyl group, etc.) , Sulfamoyl group (eg dimethylsulfamoyl group, di- (2-hydroxyethyl) sulfamoyl group etc.), sulfonyl group (eg methanesulfonyl group, phenylsulfamoyl group etc.), acyl group (acetyl group, benzoyl group etc.) , A cyano group, and an amino group (for example, a methylamino group, a diethylamino group, etc.). They may further have a substituent. Preferred examples of the substituent include an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an amino group, an acylamino group, a carbamoyl group, a sulfamoyl group, a cyano group, and a halogen atom.

R _{20 to} R ₃₂ , R ₃₄ and R ₃₅ are preferably an alkyl group, an aromatic group, a heterocyclic group, an alkoxy group, a carbamoyl group or an alkoxycarbonyl group, more preferably an alkyl group, an aromatic group, a carbamoyl group or an alkoxycarbonyl group. It is a group.

R ₃₃ is preferably an alkyl group, an aryl group or a cyano group, but most preferably a cyano group.

  In the general formulas (Cp-1) to (Cp-9), preferably (Cp-1), (Cp-3), (Cp-4), (Cp-5), (Cp-6), (Cp- 8) and (Cp-9), more preferably (Cp-1), (Cp-3), (Cp-4), (Cp-6), and (Cp-8).

  In addition, about the preferable combination of a substituent of the pigment | dye (compound) represented by the said General formula (1)-(3) or (5), the compound whose at least 1 of various substituents is the said preferable group is preferable. More preferred are compounds in which more various substituents are the preferred groups, and most preferred are compounds in which all substituents are the preferred groups.

  Specific examples of the azo dyes represented by the dyes represented by the general formulas (1) to (3) or (5) are shown below, but the azo dyes used in the present invention are limited to the following examples. It is not a thing.

  The dye represented by the dye of the general formula (1) to (3) or (5) can be synthesized by a coupling reaction between a diazo component and another component. As the main synthesis method, synthesis can be performed with reference to JP-A-2-24191, JP-A-2001-279145, JP-A-9-176532, JP-A-2003-201412, JP-A-2003-183545 and the like.

  The pigment of the above general formulas (1) to (3) or (5) alone has a high image quality “black”, that is, a color tone of any one of B, G, and R irrespective of the observation light source This dye can be used alone as a black dye, but it is generally used in combination with a dye that covers areas where absorption of this dye is low. is there. Usually, a preferable black is realized in combination with a dye or pigment having a main absorption in the yellow region. As a yellow dye, a direct dye or an acid dye represented by a commonly used azo dye or azomethine dye can be used. As the pigment, an aqueous dispersion of a general pigment having a pigment number can be used in combination. Among them, it is particularly preferable to use yellow pigments (dyes) represented by the above general formulas (Y-1) to (Y-10).

In the general formula (Y-1), R ₄₁ , R ₄₂ and R ₄₂ ′ have the same meaning as R1 described above, p represents an integer of 0 to 5, and when p is 2 or more, a plurality of R ₄₂ and R _{42 are present.} 'May be the same or different.

In the general formula (Y-2), R ₄₁ , R ₄₂ and R ₄₂ ′ are as defined above, p represents an integer of 0 to 5, and when p is 2 or more, a plurality of R ₄₂ and R ₄₂ ′ are It can be the same or different.

In the general formula (Y-3), W is —OH or —NR ₄₅ R ₄₆ , R ₄₄ has the same meaning as R ₁ described above, and R ₄₅ and R ₄₆ have the same meanings as R ₅ and R ₆ described above. B ₁ and B ₂ are as defined above. q represents an integer of 0 to 2, and when q is 2 or more, a plurality of R ₄₄ may be the same or different.

In general formula (Y-4), _R42 and p are as defined above. R ₄₃ represents an aliphatic group, and R ₄₇ represents an aliphatic group, an aromatic group, a heterocyclic group, or an acyl group.

In the general formula (Y-5), R ₄₈ and R ₄₈ ′ have the same meaning as R ₁ described above, r represents an integer of 0 to 4, and when r is 2 or more, a plurality of R ₄₈ and R ₄₈ ′ are It can be the same or different.

In the general formula (Y-6), R ₄₂ , R ₄₈ , R ₄₈ ′, W, p, and r are as defined above.

In the general formula (Y-7), R ₄₇ , R ₄₈ , W and r are as defined above, and are the same as R ₄₅ ′ and R ₄₆ ′ R ₄₅ and R ₄₆ .

In the general formula (Y-8), R _{45 to} R ₄₈ and r are as defined above, and R ₄₇ ′ is as defined above for R ₄₇ .

In the general formula (Y-9), R ₄₁ , R ₄₂ and p are as defined above, and R ₄₉ is as defined above for R ₄₇ .

In the general formula (Y-10), R ₄₁ , R ₄₂ , R ₄₄ , B ₁ , B ₂ , W, p, and q are as defined above.

In the general formulas (Y-1) to (Y-10), R ₄₁ is preferably an aliphatic group, an aromatic group or an alkoxy group. R ₄₂ and R ₄₂ ′ are preferably a halogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group or an acylamino group. R ₄₅ and R ₄₆ are preferably an aliphatic group, B ₁ is preferably ═CR ₁ —, and R ₄₄ is preferably a halogen atom, an aliphatic group, an acylamino group or an alkoxy group. R47 is preferably an aliphatic group, an aromatic group or an acyl group. R ₄₈ and R ₄₈ ′ are preferably a halogen atom, an aliphatic group, an alkoxy group, an acylamino group or an amino group.

  In the general formulas (Y-1) to (Y-10), preferably (Y-1), (Y-2), (Y-4), (Y-6), (Y-7), (Y-9) ), (Y-10), more preferably (Y-2), (Y-4), (Y-9), (Y-10).

  Specific examples of the dyes represented by the general formulas (Y-1) to (Y-10) are shown below, but the present invention is not limited thereto.

  Examples of the yellow dyes (compounds) represented by the general formulas (Y-1) to (Y-10) according to the present invention include, for example, JP-A-6-301136, JP-A-10-60296, JP-A-10-193807, JP-A-7-132680, JP-A-8-134369, JP-A-9-277693, JP-A-2001-342364, Japanese Patent No. 3078308, “The Cyanine Dyes and Related Compounds”, F.A. It can be synthesized with reference to a conventionally known method described in Hamer, Interscience Publishers, 1964 (Thecyanin Soybean and Relaided Compounds, F. Harmer, Interscience Publishers, 1964).

  Conventionally, a widely used toner manufacturing method is a so-called pulverization method, in which a resin and a colorant, and, if necessary, a release agent, a charge control agent, etc. are mixed with powder, and then sufficient heat is applied. To melt the resin and apply shearing force to disperse the additive in the resin (melt kneading), and then cool, pulverize and disperse the melt kneaded product to obtain the desired particle size and particle size distribution Get toner. The shape of the toner obtained by the pulverization method is indefinite.

  On the other hand, the polymerization method is a method in which independent polymer particles are formed from monomers, and a colorant or the like is included or combined in the polymer particles to form toner particles, and suspension polymerization and emulsion polymerization association methods are representative. Is.

  Regarding the production method for obtaining the toner of the present invention, a method of preparing by a so-called polymerization method is preferably used.

  That is, in order to stabilize the shape, for example, a uniform shape can be formed by preparing by a polymerization method, and further, the shape of the toner particles can be further rounded by drying in a fluid state at the time of drying. it can.

  As a polymerization method, a toner component such as a colorant and a release agent is dispersed in a polymerizable monomer for preparing a resin, and then suspended in water, and then the suspended particles are polymerized to obtain a toner. Any of the so-called emulsion association type prepared by preparing resin particles by suspension polymerization or emulsion polymerization, and mixing the resin particles with a dispersion of toner constituents such as a colorant to combine the particles. Good.

  In general, the emulsion association type is more preferable. In the suspension polymerization method, since the shape of the particles is spherical, a step such as pulverization is required after that, and the problem that the roundness of the shape is impaired by the impact force at that time may occur.

  In order to obtain the configuration of the present invention, particularly when the particles prepared by the polymerization method are dried, it is possible to better achieve the configuration of the present invention by adopting a method of heating and drying the particles in an air stream. it can.

  The reason for this is not clear, but heat drying in an air flow in the presence of excessive moisture, and a shape change occurs due to heating of the swollen portion with moisture in a very small region, resulting in a slight shape. It is estimated that it will be rounded. In the case of performing this heating, it is preferable to perform heat treatment in an air stream in the reduction rate drying stage.

  At this time, it is more preferable that 10% by mass or more of water is present with respect to the polymer particles. The reason for this is that since the heating is performed in an air stream, if the particles themselves reach a high temperature, the shape may become spherical, or the surface composition may change. It is preferable to use a material containing 10% by mass or more of moisture in order to prevent the temperature from becoming so high as to soften. This method does not reach the temperature at which the particles themselves soften, and the spheroidization of the entire shape of the toner particles itself is not promoted.

  In addition, although it does not specifically limit as an upper limit of moisture content, it is 50 mass%. If there is too much water than this amount, heat transfer is insufficient and it may be difficult to make the shape uniform.

  Examples of the airflow drying apparatus that can be preferably used in the present invention include a so-called spray drying apparatus, a vibrating fluidized bed dryer, a high-speed fluidized dryer, and a flash jet dryer. In this case, the temperature of the airflow is preferably 30 to 200 ° C.

  Hereinafter, the present invention will be further described including related technologies.

1. Toner for electrostatic charge development of the present invention The toner of the present invention contains at least a resin and a colorant, but may contain a release agent, a charge control agent, etc., which are fixing improvers, if necessary. . Further, an external additive composed of inorganic fine particles or organic fine particles may be added to the toner particles containing the resin and the colorant as main components. A toner added with an external additive is called a toner, and a toner before addition is sometimes called a colored particle.

  The toner of the present invention is preferably prepared by a production method in which resin particles are associated in an aqueous medium. In this case, for example, the monomer is emulsion-polymerized in a liquid to which the necessary additive emulsion is added to produce fine polymer particles, and then an organic solvent, an aggregating agent, and the like are added to associate. It can be manufactured by the method. A method of preparing by mixing with a dispersion liquid such as a release agent and a colorant necessary for the composition of the toner at the time of association, and a toner component such as a release agent and a colorant dispersed in the monomer And a method of emulsion polymerization. Here, the term “association” means that a plurality of resin particles are fused.

  Furthermore, it can also be prepared by a suspension polymerization method, but in that case, since it is necessary to make the shape amorphous, after applying mechanical impact force to the polymer particles and making it amorphous. It is necessary to control the shape.

  The method for producing the toner of the present invention is not particularly limited as described above, but preferably disclosed in JP-A-5-265252, JP-A-6-329947, and JP-A-9-15904. The method of heat-processing after forming particle | grains by the method shown is preferable. That is, a method of associating a plurality of fine particles composed of a resin, a colorant, and the like, in particular, after dispersing them in water using an emulsifier, adding a flocculant of a critical aggregation concentration or higher and salting out, and at the same time The toner of the present invention can be formed by heating and fusing at a temperature equal to or higher than the glass transition temperature of the polymer itself, and heating and drying the particles in a fluid state while containing water. Here, an organic solvent that is infinitely soluble in water may be added simultaneously with the flocculant.

  Specifically, those used as monomers constituting the resin are styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4- Dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, p- styrene or styrene derivatives such as n-decylstyrene, pn-dodecylstyrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-methacrylate -Octyl, 2-ethylhexyl methacrylate, stearyl methacrylate, Methacrylic acid ester derivatives such as lauryl tacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, acrylic Isobutyl acid, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, acrylic acid ester derivatives such as phenyl acrylate, olefins such as ethylene, propylene, isobutylene, vinyl chloride, vinylidene chloride, odor Halogenated vinyls such as vinyl fluoride, vinyl fluoride, vinylidene fluoride, vinyl esters such as vinyl propionate, vinyl acetate, vinyl benzoate, vinyl methyl ether, vinyl ethyl ether Vinyl ethers such as vinyl, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, vinyl naphthalene, vinyl pyridine, etc. There are acrylic acid or methacrylic acid derivatives such as vinyl compounds, acrylonitrile, methacrylonitrile, acrylamide and the like. These vinyl monomers can be used alone or in combination.

  Further, it is more preferable to use a combination of monomers having an ionic dissociation group as monomers constituting the resin. For example, it has a substituent such as a carboxyl group, a sulfonic acid group, a phosphoric acid group as a constituent group of the monomer, specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumar Acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrene sulfonic acid, allyl sulfosuccinic acid, 2-acrylamido-2-methylpropane sulfonic acid, acid phosphooxyethyl methacrylate, 3-chloro-2-acid phosphooxy And propyl methacrylate.

  Furthermore, polyfunctionality such as divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, etc. It is also possible to use a crosslinkable resin by using a functional vinyl.

  These monomers can be polymerized using a radical polymerization initiator. In this case, an oil-soluble polymerization initiator can be used in the suspension polymerization method. As this oil-soluble polymerization initiator, azoisobutyronitrile, lauryl peroxide, benzoyl peroxide, or the like can be used. Moreover, when using an emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, hydrogen peroxide and the like.

  As the resin excellent in the present invention, those having a glass transition point of 20 to 90 ° C. are preferred, and those having a softening point of 80 to 220 ° C. are preferred. The glass transition point is measured by a differential calorimetric analysis method, and the softening point can be measured by a Koka flow tester. Further, these resins preferably have a molecular weight measured by gel permeation chromatography of 1,000 to 100,000 in terms of number average molecular weight (Mn) and 2000 to 1,000,000 in terms of weight average molecular weight (Mw). Further, the molecular weight distribution is preferably such that Mw / Mn is 1.5 to 100, particularly 1.8 to 70.

  The flocculant used is not particularly limited, but those selected from metal salts are preferably used. Specifically, as a monovalent metal, for example, an alkali metal salt such as sodium, potassium or lithium, as a divalent metal, for example, an alkaline earth metal salt such as calcium or magnesium, or a divalent metal such as manganese or copper. And salts of trivalent metals such as iron and aluminum, and specific salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, etc. Can be mentioned. These may be used in combination.

  These flocculants are preferably added in an amount equal to or higher than the critical aggregation concentration. The critical flocculation concentration is an index relating to the stability of the aqueous dispersion, and indicates a concentration at which flocculation occurs when a flocculant is added. This critical aggregation concentration varies greatly depending on the emulsified components and the dispersant itself. For example, it is described in Seizo Okamura et al., “Polymer Chemistry 17, 601 (1960) edited by Japan Society of Polymer Science”, and the like, and a detailed critical aggregation concentration can be obtained. As another method, a desired salt is added to the target particle dispersion at different concentrations, the ζ (zeta) potential of the dispersion is measured, and the salt concentration at which this value changes is obtained as the critical aggregation concentration. You can also.

  The addition amount of the flocculant of the present invention may be not less than the critical aggregation concentration, but is preferably 1.2 times or more, more preferably 1.5 times or more the critical aggregation concentration.

  The infinitely soluble solvent means a solvent that is infinitely soluble in water, and this solvent is selected so as not to dissolve the formed resin in the present invention. Specific examples include alcohols such as methanol, ethanol, propanol, isopropanol, t-butanol, methoxyethanol, and butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. In particular, ethanol, propanol, and isopropyl alcohol are preferable.

  The addition amount of the infinitely soluble solvent is preferably 1 to 300% by volume with respect to the polymer-containing dispersion added with the flocculant.

  In order to make the shape uniform, it is preferable to fluidly dry a slurry in which 10% by mass or more of water is present after preparing and filtering colored particles. Those having a polar group are preferred. The reason for this is considered to be that it is particularly easy to make the shape uniform, since the water present in the polymer in which the polar group is present swells somewhat.

  As the colorant used in the toner of the present invention, in addition to the azo dye of the present invention, a magnetic material, a dye, a pigment and the like can be arbitrarily used, and the magnetic material is a ferromagnetic metal such as iron, nickel, cobalt, etc. , Alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys that do not contain ferromagnetic metals but exhibit ferromagnetism by heat treatment, such as manganese-copper-aluminum, manganese-copper-tin, etc. A kind of alloy called Heusler alloy, chromium dioxide or the like can be used.

  The coloring matter (azo coloring matter) of the present invention may be used alone or in combination with other dyes. Examples of dyes that can be used in combination include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 etc. can be used, and a mixture thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122, 139, 144, 149, 166, 177, 178, 222, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment yellow 14, 17, 93, 94, 138, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 60, etc. can be used, and yellow dyes represented by the general formulas (Y-1) to (Y-10) according to the present invention are preferably used. Mixtures of these can also be used. The number average primary particle diameter varies depending on the type, but is preferably about 10 to 200 nm.

  As a method for adding the colorant, the polymer particles prepared by the emulsion polymerization method are added at the stage of agglomerating by adding an aggregating agent, and the polymer is colored, or at the stage of polymerizing the monomer. The method of adding, polymerizing, and making it a colored particle etc. can be used. In addition, when adding a coloring agent in the step which prepares a polymer, it is preferable to use it, treating the surface with a coupling agent etc. so that radical polymerization property may not be inhibited.

  The addition amount of the pigment | dye of this invention is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.

  Further, a low molecular weight polypropylene (number average molecular weight = 1500 to 9000), a low molecular weight polyethylene, or the like as a fixing property improving agent may be added.

  An azo metal complex, a quaternary ammonium salt, or the like may be used as a charge control agent.

  Further, from the viewpoint of imparting fluidity, particles obtained by polymerizing inorganic fine particles and organic fine particles may be externally added to toner particles (colored particles). In this case, the use of inorganic fine particles is preferable, the use of inorganic oxide particles such as silica, titania, and alumina is preferable, and these inorganic fine particles are hydrophobized with a silane coupling agent, a titanium coupling agent, or the like. Is preferred.

  The toner of the present invention has a volume average particle diameter of 3 to 9 μm. This particle size can be controlled by the concentration of the flocculant, the amount of organic solvent added, and the composition of the polymer itself. The volume average particle diameter of the toner particles (colored particles) is measured with a Coulter Counter TA-II or Coulter Multisizer.

  The toner of the present invention may be used, for example, as a one-component magnetic toner containing a magnetic material, as a two-component developer mixed with a so-called carrier, or as a non-magnetic toner alone. However, in the present invention, it is more preferable to use as a two-component developer used by mixing with a carrier.

  As the carrier constituting the two-component developer, either an uncoated carrier composed only of magnetic material particles such as iron or ferrite, or a resin-coated carrier whose magnetic material particle surface is coated with a resin or the like may be used. The average particle size of the carrier is preferably 30 to 150 μm in terms of volume average particle size. The resin for coating is not particularly limited, and examples thereof include styrene-acrylic resins and silicone resins.

2. Image Forming Method The developing method in which the toner of the present invention can be used is not particularly limited. It can be suitably used for a contact development system or a non-contact development system. In particular, the toner of the present invention has a high charge rising property and is useful for a non-contact development method. That is, in the non-contact development method, the change in the development electric field is large, so that a slight change in charging acts on the development itself. However, since the toner of the present invention has a high charge rising property, there is little change in charge, and a stable charge amount can be secured, so that a stable image can be formed over a long period of time even with a non-contact development method. it can.

  For contact-type development, the layer thickness of the developer having the toner of the present invention is preferably 0.1 to 8 mm, particularly 0.4 to 5 mm in the development region. The gap between the photosensitive member and the developer carrying member is preferably 0.15 to 7 mm, particularly preferably 0.2 to 4 mm.

Further, as a non-contact type development method, the developer layer formed on the developer carrying member and the photoreceptor are not in contact with each other, and the developer layer is formed as a thin layer in order to constitute this development method. It is preferable. In this method, a developer layer having a thickness of 20 to 500 μm is formed in the developing region on the surface of the developer carrying member, and the gap between the photosensitive member and the developer carrying member is larger than the developer layer. The thin layer is formed by a magnetic blade using magnetic force, a method of pressing a developer layer regulating rod on the surface of the developer carrying member, or the like. Further, there is a method of regulating the developer layer by bringing a urethane blade, a phosphor bronze plate or the like into contact with the surface of the developer carrying member. The pressing force of the pressing restricting member is preferably 1 × 9.8 × 10 ⁻³ to 15 × 9.8 × 10 ⁻³ N / mm. When the pressing force is small, the regulation force is insufficient, and thus the conveyance is likely to be unstable. On the other hand, when the pressing force is large, the stress on the developer is increased, and the durability of the developer is likely to be lowered. A preferred range is 3 × 9.8 × 10 ⁻³ to 10 × 9.8 × 10 ⁻³ N / mm. The gap between the developer carrying member and the photoreceptor surface must be larger than the developer layer. Further, when a developing bias is applied during development, either a method of applying only a DC component or a method of applying an AC bias may be used.

  The developer carrying member preferably has a diameter of 10 to 40 mm. When the diameter is small, mixing of the developer is insufficient, making it difficult to ensure sufficient mixing to impart sufficient charge to the toner, and when the diameter is large, the centrifugal force on the developer increases. Prone to toner scattering problem.

  Hereinafter, an example of the non-contact development method will be described with reference to FIG.

  FIG. 1 is a schematic view of a developing portion of a non-contact developing system that can be suitably used for image formation using the toner of the present invention, wherein 1 is a photoreceptor, 2 is a developer carrier, and 3 is a toner of the present invention. 2 is a developer layer regulating member, 5 is a developing region, 6 is a developer layer, and 7 is a power source for forming an alternating electric field.

  The two-component developer containing the toner of the present invention is carried by a magnetic force on the developer carrying member 2 having a magnet 2B therein, and is conveyed to the developing region 5 by the movement of the developing sleeve 2A. During the conveyance, the thickness of the developer layer 6 is regulated by the developer layer regulating member 4 so that the developer layer 6 does not come into contact with the photoreceptor 1 in the development region 5.

  The minimum gap (Dsd) of the development region 5 is larger than the thickness (preferably 20 to 500 μm) of the developer layer 6 conveyed to that region, for example, about 100 to 1000 μm. The power source 7 for forming the alternating electric field is preferably an alternating current having a frequency of 1 to 10 kHz and a voltage of 1 to 3 kVp-p. The power supply 7 may have a configuration in which direct current is added in series with alternating current as necessary. In that case, the DC voltage is preferably 300 to 800V.

  When the toner of the present invention is applied to a color image forming system, a system that sequentially transfers a single color image onto a photoconductor while transferring it to an image support (this is a sequential transfer system, shown in FIG. 2), or a photoconductor Examples thereof include a system in which a single color image is developed a plurality of times and a color image is formed and then transferred to an image support in a lump (this is referred to as a lump transfer system and shown in FIG. 3).

  2 and 3, 11 is a charger, 12 is a developing device (developing unit), and 13 is a cleaning unit. Reference numeral 14 denotes a photosensitive drum, 15 denotes a transfer drum, 16 denotes a conveyance unit, 17 denotes an adsorption electrode, 18 denotes a transfer electrode, 19 denotes a peeling electrode, 20 denotes a removal electrode, and 21 denotes a conveyance unit.

  As the developer carrying member used in the present invention, those having a magnet built in the carrying member are often used, and as the developer carrying member surface, aluminum or aluminum or stainless steel whose surface is oxidized is used. The product made from is used.

  The toner image formed on the photoreceptor by the various methods described above is transferred to a transfer material such as paper by a transfer process. The transfer method is not particularly limited, and various methods such as a so-called corona transfer method and a roller transfer method can be employed.

  After the toner image is transferred to the transfer material, the toner remaining on the photoconductor is removed by cleaning, and the photoconductor is repeatedly used in the next process.

  In the present invention, the cleaning mechanism is not particularly limited, and a known cleaning mechanism such as a blade cleaning system, a magnetic brush cleaning system, and a fur brush cleaning system can be arbitrarily used. A preferable cleaning mechanism is a blade cleaning system using a so-called cleaning blade.

  A suitable fixing method used in the present invention is a heat roll fixing method.

  In this fixing method, in many cases, an upper roller having a heat source inside a metal cylinder composed of iron, aluminum or the like whose surface is coated with tetrafluoroethylene or polytetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer, silicone, and silicone And a lower roller made of rubber or the like. A typical example of the heat source is one that has a linear heater and heats the surface temperature of the upper roller to about 120 to 200 ° C. In the fixing unit, pressure is applied between the upper roller and the lower roller to deform the lower roller to form a so-called nip. The nip width is 1 to 10 mm, preferably 1.5 to 7 mm. The fixing linear velocity is preferably 40 mm / sec to 400 mm / sec. If the nip is narrow, heat cannot be uniformly applied to the toner, and uneven fixing occurs. On the other hand, when the nip width is wide, the melting of the resin is promoted, and the problem of excessive fixing offset occurs.

  A fixing cleaning mechanism may be provided for use. As this method, a method of supplying silicone oil to the upper roller or film for fixing, or a method of cleaning with a pad, roller, web or the like impregnated with silicone oil can be used.

  Next, an electrophotographic toner obtained by dispersing colored fine particles containing a resin having a composition different from that of the thermoplastic resin and a dye in the thermoplastic resin will be described.

(Colored fine particles)
The electrophotographic toner of the present invention is formed by dispersing at least colored fine particles in a thermoplastic resin, and the colored fine particles preferably contain a resin and a dye having a composition different from that of the thermoplastic resin. Instead of directly dispersing or dissolving a dye in a toner binder resin, which is generally known as a toner using a dye, a composition different from colored fine particles, that is, a thermoplastic resin (hereinafter also referred to as a binder resin). It is also preferable to disperse colored fine particles containing a resin and a dye in a thermoplastic resin.

  Since the dye in the colored fine particles dissolves at the molecular level in the resin, it becomes possible to eliminate components such as concealing particles that block light in the toner, and the transparency of each toner in a single color is improved. It is considered that transparency in the superimposed color is also improved. FIG. 4 schematically shows a cross section of the toner particles of the present invention in which colored fine particles are dispersed in a thermoplastic resin. Further, as shown in FIG. 5, in the toner of the present invention, the colored fine particles may be coated with an outer shell resin (shell). In this case, the resin and the thermoplastic resin constituting the inside (core) of the colored fine particles If there are no restrictions on the combination of (binder resin), the degree of freedom of material is large, and only the outer shell resin (shell) is the same for the four color toners (yellow, magenta, cyan, black), the same Since it can be manufactured under manufacturing conditions, there is a great cost advantage. In addition, since the dye that is the colorant does not migrate out of the colored fine particles (exposure to the surface of the colored fine particles), dye sublimation or oil during heat fixing, which is generally regarded as a problem in toners using dyes There is no concern about contamination.

(Production method of particles)
Next, a method for producing colored fine particles according to the present invention will be described.

  The colored fine particles of the present invention can be obtained, for example, by dissolving (or dispersing) a resin and a dye in an organic solvent, emulsifying and dispersing in water, and then removing the organic solvent. ), A monomer having a polymerizable unsaturated double bond is added to the colored fine particles, emulsion polymerization is performed in the presence of an activator, and a core-shell structure is formed by depositing on the core surface simultaneously with the polymerization. Colored fine particles can be obtained. Alternatively, for example, an aqueous dispersion of resin fine particles is formed in advance by emulsion polymerization, an organic solvent solution in which a dye is dissolved is mixed with the aqueous dispersion of resin fine particles, and then the resin fine particles are impregnated with the dye. It can be obtained by various methods such as a method of forming a shell using colored fine particles as a core.

  The shell is preferably made of an organic resin, and as a method of forming the shell, there is a method in which a resin dissolved in an organic solvent is gradually dropped and the resin is adsorbed on the surface of the colored fine particle core simultaneously with precipitation. In the invention, after forming colored fine particles as a core containing a colorant and a resin, a monomer having a polymerizable unsaturated double bond is added and emulsion polymerization is performed in the presence of an activator. A method of forming a shell by depositing on is preferable.

(Core shell structure)
In the present invention, the core-shell structure means a form in which two or more kinds of resins or dyes having different compositions are present in phase separation in the particles. Therefore, the shell portion may not only cover the core portion completely, but may cover a portion of the core portion. Further, a part of the resin forming the shell may form a domain or the like in the core particle. Further, it may have a multilayer structure of three or more layers including another layer having a different composition between the core part and the shell part.

  In the present invention, the colored fine particles form a core-shell structure, and the colored portion formed by the resin and the dye in the colored fine particles is used as a core, which is further coated with an outer shell resin to form a core-shell structure. It is preferable.

(Thermoplastic Resin) Binder Resin The thermoplastic resin contained in the toner of the present invention is preferably a thermoplastic resin that has high adhesion to colored fine particles, and particularly preferably a solvent-soluble one. Further, if the polymer precursor is soluble in a solvent, a curable resin that forms a three-dimensional structure can also be used. As the thermoplastic resin, those generally used as a binder resin for a toner are used without particular limitation. For example, styrene resins, acrylic resins such as alkyl acrylates and alkyl methacrylates, and styrene acrylic copolymer resins. Polyester resin, silicon resin, olefin resin, amide resin, epoxy resin, etc. are preferably used, but in order to improve transparency and color reproducibility of superimposed images, transparency is high and melting characteristics are high. Resins with low viscosity and high sharp melt properties are required. As the binder resin having such characteristics, styrene resin, acrylic resin, and polyester resin are suitable.

  As the binder resin, the number average molecular weight (Mn) is 3000 to 6000, preferably 3500 to 5500, and the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 6, preferably It is desirable to use a resin having a glass transition point of 2.5 to 5.5, a glass transition point of 50 to 70 ° C, preferably 55 to 70 ° C, and a softening temperature of 90 to 110 ° C, preferably 90 to 105 ° C.

  When the number average molecular weight of the binder resin is smaller than 3000, the image portion is peeled off when a full-color solid image is folded, and image defect occurs (folding fixability deteriorates). And the fixing strength decreases. If Mw / Mn is less than 2, high temperature offset is likely to occur. If Mw / Mn is greater than 6, sharp melt characteristics at the time of fixing deteriorate, and the translucency of toner and color mixing at the time of full color image formation decrease. End up. Further, if the glass transition point is lower than 50 ° C., the heat resistance of the toner becomes insufficient, and toner aggregation tends to occur during storage. Color mixing at the time of image formation is reduced. Further, when the softening temperature is lower than 90 ° C., high temperature offset tends to occur. When the softening temperature is higher than 110 ° C., fixing strength, translucency, color mixing property, and gloss of a full color image are deteriorated.

(Core resin)
The resin that forms the inside (core) of the colored fine particles of the present invention will be described.

  The resin used in the interior (core) of the colored fine particles of the present invention is not particularly limited as long as it has a composition different from that of the thermoplastic resin. For example, a (meth) acrylate resin, a polyester resin, a polyamide resin is used. Resin, polyimide resin, polystyrene resin, polyepoxy resin, polyester resin, amino resin, fluorine resin, phenol resin, polyurethane resin, polyethylene resin, polyvinyl chloride resin, polyvinyl alcohol resin, Examples include polyether resins, polyether ketone resins, polyphenylene sulfide resins, polycarbonate resins, and aramid resins, but (meth) acrylate resins, polystyrene resins, polyethylene resins, polyvinyl chloride resins are preferable. , Such as polyvinyl alcohol resin Resin obtained by polymerizing sexual ethylenically unsaturated double bond is preferred. Most preferred are (meth) acrylate resins and polystyrene resins.

  The (meth) acrylate resin is synthesized by homopolymerizing or copolymerizing various methacrylate monomers or acrylate monomers, and by changing the monomer species and the monomer composition ratio, the desired (meth) An acrylate resin can be obtained. Further, in the present invention, it can be used together with a (meth) acrylate monomer and also with a copolymerizable monomer having an unsaturated double bond other than the (meth) acrylate monomer, In the present invention, a plurality of other resins may be mixed together with the poly (meth) acrylate resin.

  Examples of the monomer component forming the (meth) acrylate resin used in the present invention include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. , Isopropyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, acetoacetoxyethyl (meth) acrylate, dimethylaminoethyl (meth) Acrylate, 2-hydroxypropyl (meth) acrylate, di (ethylene glycol) ethyl ether (meth) acrylate, ethylene glycol methyl ether (meth) acrylate, isobonyl (meth) acrylate Ethyltrimethylammonium chloride (meth) acrylate, trifluoroethyl (meth) acrylate, octafluoropentyl (meth) acrylate, 2-acetamidomethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-dimethylaminoethyl (Meth) acrylate, 3-trimethoxysilanepropyl (meth) acrylate, benzyl (meth) acrylate, tridecyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dodecyl (meth) acrylate , Octadecyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (Meth) acrylate, glycidyl (meth) acrylate and the like can be mentioned, but (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, stearyl are preferable. (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, acetoacetoxyethyl (meth) acrylate, benzyl (meth) acrylate, tridecyl (meth) acrylate, dodecyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

  Polystyrene resins include homopolymers of styrene monomers or random copolymers, block copolymers, and graft copolymers obtained by copolymerizing monomers with other unsaturated double bonds that can be copolymerized with styrene monomers. Can be mentioned. Furthermore, blends and polymer alloys obtained by blending such polymers with other polymers are also included. Examples of the styrene monomer include nuclear alkyl substitution such as styrene, α-methylstyrene, α-ethylstyrene, α-methylstyrene-p-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, etc. Examples thereof include nuclear halogenated styrenes such as styrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-bromostyrene, dichlorostyrene, dibromostyrene, trichlorostyrene, and tribromostyrene. Styrene and α-methylstyrene are preferred.

  Resins used in the present invention are synthesized by homopolymerizing or copolymerizing them, for example, copolymer resins such as benzyl methacrylate / ethyl acrylate or butyl acrylate, methyl methacrylate / 2-ethylhexyl methacrylate, etc. A copolymer resin of methyl methacrylate / methacrylic acid / stearyl methacrylate / acetoacetoxyethyl methacrylate, a copolymer resin of styrene / acetoacetoxyethyl methacrylate / stearyl methacrylate, and styrene / 2- Examples include copolymers of hydroxyethyl methacrylate / stearyl methacrylate, and copolymer resins such as 2-ethylhexyl methacrylate / 2-hydroxyethyl methacrylate. It is.

  The resin used in the present invention preferably has a number average molecular weight of 500 to 100,000, particularly 1,000 to 30,000 from the viewpoint of durability and fine particle formability.

(Outer shell resin)
In the present invention, the outer shell resin that covers the outer shell of the colored fine particles to form the shell is not particularly limited. For example, poly (meth) acrylate resin, polyester resin, polyamide resin, polyimide resin, Polystyrene resins, polyepoxy resins, polyester resins, amino resins, fluorine resins, phenol resins, polyurethane resins, polyethylene resins, polyvinyl chloride resins, polyvinyl alcohol resins, polyarylate resins, poly Examples thereof include ether resins, polyether ketone resins, polyphenylene sulfide resins, polycarbonate resins, and aramid resins. In particular, from the viewpoint of combination with a toner binder resin (thermoplastic resin), poly (meta ) Acrylate resin.

  Poly (meth) acrylate resin is synthesized by homopolymerization or copolymerization of various (meth) acrylate monomers, and the desired poly (meth) acrylate can be changed by changing monomer species and monomer composition ratios. Based resin can be obtained. In the present invention, a plurality of other resins can be mixed together with the poly (meth) acrylate resin.

  Examples of the monomer component forming the poly (meth) acrylate resin used in the present invention include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth). Acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, acetoacetoxyethyl (meth) acrylate, dimethylaminoethyl (meta ) Acrylate, 2-hydroxypropyl (meth) acrylate, di (ethylene glycol) ethyl ether (meth) acrylate, ethylene glycol methyl ether (meth) acrylate, isobornyl (meth) acrylate Rate, ethyltrimethylammonium chloride (meth) acrylate, trifluoroethyl (meth) acrylate, octafluoropentyl (meth) acrylate, 2-acetamidomethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-dimethylaminoethyl (Meth) acrylate, 3-trimethoxysilanepropyl (meth) acrylate, benzyl (meth) acrylate, tridecyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dodecyl (meth) acrylate , Octadecyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, Nyl (meth) acrylate, glycidyl (meth) acrylate, etc. are mentioned, but (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, Stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, acetoacetoxyethyl (meth) acrylate, benzyl (meth) acrylate, tridecyl (meth) acrylate, dodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate . Preferred are methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate.

  Further, the outer shell resin in the present invention may be a copolymer with a reactive emulsifier.

(Reactive emulsifier)
The reactive emulsifier preferably used in the present invention may be either an anionic or nonionic reactive emulsifier, but a compound having the following A, B, or C substituent is preferable.

  A: A linear alkyl group, a branched alkyl group, or a substituted or unsubstituted aromatic group, and a substituent having a total carbon number of 6 or more.

  B: Nonionic substituent or anionic substituent that speaks for surface activity.

C: Polymerizable group capable of radical polymerization Examples of the linear alkyl group described in item A include a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, and the like, and examples of the branched alkyl group include: 2-ethylhexyl group etc. are mentioned, As an aromatic group, a phenyl group, nonylphenyl group, a naphthyl group etc. are mentioned, for example.

  Examples of the nonionic substituent or anionic substituent that expresses the emulsifying ability (surfactant ability) described in Item B include polyethylene oxide, polypropylene oxide, polyalkylene oxide of a copolymer thereof, and the like. Specific examples of the anionic substituent include carboxylic acid, phosphoric acid, sulfonic acid, and salts thereof. Moreover, it is one of the specific examples of an anionic group that the above-mentioned anionic group was substituted at the terminal of alkylene oxide. The substituent represented by the item B is preferably an anionic group, and more preferably a terminal terminal is a salt.

  The polymerizable group capable of radical polymerization described in Section C is a group that undergoes polymerization or crosslinking reaction depending on the radical active species. For example, a vinyl group having an ethylenically unsaturated bond, an allyl group, a 1-propenyl group, Examples thereof include an isopropenyl group, an acrylic group, a methacryl group, a maleimide group, an acrylamide group, and a styryl group.

  As the reactive emulsifier used in the present invention, compounds represented by the following general formulas (A) to (C) are preferable.

In the general formula (A), R ₁ represents a linear alkyl group having 6 to 20 carbon atoms, a branched alkyl group, or a substituted or unsubstituted aromatic group. For example, heptyl group or octyl group described in the above section A Group, nonyl group, decyl group, linear alkyl group such as dodecyl group, branched alkyl group such as 2-ethylhexyl group, aromatic group such as phenyl group, nonylphenyl group, naphthyl group, and the like.

R ₂ represents a substituent having a polymerizable group capable of radical polymerization, and examples thereof include an acryl group, a methacryl group, and a maleimide group that are ethylenically unsaturated bonds described in the above section C. Y ₁ represents a sulfonic acid, a carboxylic acid, or a salt thereof.

  The compound represented by the general formula (A) can be synthesized by a person skilled in the art by a known method. Moreover, it can obtain easily from a commercial item, for example, "Ramtel S-120" and "Ramtel S-120A" by Kao Corporation. Examples thereof include “Ramtel S-180”, “Ramtel S-180A” and “Eleminol JS-2” manufactured by Sanyo Chemical Industries.

In the general formula (B), R ₃ has the same meaning as R _{1 in the} general formula (A), and R ₄ in the general formula (B) is the same as R _{2 in the} general formula (A). It is synonymous. Y ₂ represents a hydrogen atom, a sulfonic acid, a carboxylic acid, or a salt thereof. AO represents an alkylene oxide.

  The compound represented by the general formula (B) can be synthesized by a person skilled in the art by a known method. Moreover, it can obtain easily from a commercial item, for example, NE such as "Adekaria soap NE-10", "Adekaria soap NE-20", "Adekaria soap NE-30" made by Asahi Denka Kogyo Co., Ltd. Series, “Adekaria Soap SE-10N”, “Adekaria Soap SE-20N”, “Adekaria Soap SE-30N”, etc., “Aqualon RN-10”, “Aquaron RN” manufactured by Daiichi Kogyo Seiyaku Co., Ltd. -20 series such as “AQUALON RN-30”, “AQUALON RN-50”, “AQUALON HS-05”, “AQUALON HS-10”, “AQUALON HS-20”, “AQUALON HS-30”, etc. HS series or Aqualon BC series.

In the general formula (C), R ₅ has the same meaning as R _{1 in the} general formula (A), R _{6 in the} general formula (C) has the same meaning as R _{2 in the} general formula (A), and Y _{3 in the} general formula (C) has the same meaning as Y _{1 in the} general formula (A), and AO in the general formula (C) has the same meaning as AO in the general formula (B).

  The compound represented by the general formula (C) can be synthesized by a person skilled in the art by a known method. Moreover, it can obtain easily from a commercial item, for example, "AQUALON KH-05", "AQUALON KH-10", "AQUALON KH-20", etc. by Dai-ichi Kogyo Seiyaku Co., Ltd. can be mentioned.

  In the general formulas (B) and (C), the average polymerization degree n of the alkylene oxide chain (AO) is preferably 1 to 10, for example, “AQUALON KH-05” manufactured by Daiichi Kogyo Seiyaku Co., Ltd. , “AQUALON KH-10”, “AQUALON HS-05”, “AQUALON HS-10”, and the like.

In the present invention, the reactive emulsifier is preferably anionic. For example, the above-mentioned “ADEKA rear soap SE series” (manufactured by Asahi Denka Kogyo Co., Ltd.), “AQUALON HS series” (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ), “Latemul S Series” (Kao Corporation), “Eleminol JS Series” (manufactured by Sanyo Chemical Industries), and the like.
In the present invention, the reaction emulsifier is used in a total amount of about 100 parts by mass of the resin forming the colored fine particles of the present invention, generally 0.1 to 80 parts by mass, preferably 1 to 70 parts by mass. Particularly preferably, 10 to 60 parts by mass are used.

(Normal surfactant)
In emulsification when preparing the colored fine particles of the present invention, a normal anionic emulsifier (surfactant) and / or a nonionic emulsifier (surfactant) can be used as necessary.
Examples of the normal nonionic emulsifier include, for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether, polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonylphenyl ether, and sorbitan monolaurate. Sorbitan higher fatty acid esters such as sorbitan monostearate and sorbitan trioleate, polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene monolaurate, polyoxyethylene monostearate, etc. Higher fatty acid esters of glycerin such as polyoxyethylene higher fatty acid esters, oleic acid monoglyceride, stearic acid monoglyceride Class, polyoxyethylene - polyoxypropylene - and the like block copolymer.

  Examples of the usual anionic emulsifier include higher fatty acid salts such as sodium oleate, alkylaryl sulfonates such as sodium dodecylbenzene sulfonate, alkyl sulfates such as sodium lauryl sulfate, polyethoxyethylene lauryl ether sulfate. Polyoxyethylene alkyl ether sulfates such as sodium, polyoxyethylene alkyl aryl ether sulfates such as sodium polyoxyethylene nonylphenyl ether sulfate, sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene lauryl sulfosuccinate And alkylsulfosuccinic acid ester salts, and derivatives thereof.

(Particle size)
In the present invention, the colored fine particles preferably have a volume average particle size in the range of 10 nm to 1 μm. When the volume average particle size is 10 nm or less, the surface area per unit volume becomes very large. The effect of encapsulating in the polymer is reduced, and the stability of the colored fine particles is likely to be deteriorated, and the storage stability is likely to be deteriorated. On the other hand, when the particle size is larger than 1 μm, sedimentation is likely to occur during the production of the fine particle, and the stagnation stability is deteriorated. In addition, when the toner is used, the glossiness is deteriorated and the transparency is remarkably deteriorated. Accordingly, the average particle size of the colored fine particles is preferably 10 to 1 μm, more preferably 20 to 500 nm.

  The volume average particle diameter can be obtained by using a dynamic light scattering method, a laser diffraction method, a centrifugal sedimentation method, an FFF method, an electrical detector method, etc. In the present invention, a Zetasizer manufactured by Malvern is used. It is preferable to use the dynamic light scattering method.

(Dye content)
The colored fine particles of the present invention preferably have a dye content in the range of 10 to 70% by mass. By containing the dye in an amount of 10 to 70% by mass, a sufficient concentration can be obtained, and the colorant can be protected by the resin. Since it is expressed and is excellent in storage stability as a fine particle dispersion, an increase in particle diameter due to aggregation or the like can be prevented.

(toner)
In the toner of the present invention, a known charge control agent, offset preventive agent and the like can be used in addition to the above-described thermoplastic resin and colored fine particles. The charge control agent is not particularly limited. As the negative charge control agent used for the color toner, a colorless, white or light color charge control agent that does not adversely affect the color tone and translucency of the color toner can be used. For example, a zinc or chromium metal complex of a salicylic acid derivative, A calixarene compound, an organic boron compound, a fluorine-containing quaternary ammonium salt compound or the like is preferably used. Examples of the salicylic acid metal complex include those described in JP-A Nos. 53-127726 and 62-145255, and examples of calixarene compounds include those described in JP-A No. 2-201378. However, as the organic boron compound, for example, those described in JP-A-2-221967 can be used, and as the organic boron compound, for example, those described in JP-A-3-1162 can be used. When such a charge control agent is used, it is desirable to use 0.1 to 10 parts by mass, preferably 0.5 to 5.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin (binder resin).

  There are no particular restrictions on the anti-offset agent. For example, polyethylene wax, oxidized polyethylene wax, polypropylene wax, oxidized polypropylene wax, carnauba wax, sazol wax, rice wax, candelilla wax, jojoba oil wax, honey Wax wax or the like can be used. The added amount of such wax is 0.5 to 5 parts by mass, preferably 1 to 3 parts by mass with respect to 100 parts by mass of the thermoplastic resin (binder resin). This is because if the addition amount is less than 0.5 parts by mass, the effect of the addition is insufficient, and if it exceeds 5 parts by mass, the translucency and color reproducibility deteriorate.

  The toner of the present invention uses the above-described thermoplastic resin (binder resin), colored fine particles and other desired additives, and other methods such as suspension polymerization, emulsion polymerization, emulsion dispersion granulation, encapsulation, etc. It can be produced by a known method. Among these production methods, the emulsion polymerization method is preferred from the viewpoints of production cost and production stability in consideration of the reduction in the toner particle size accompanying the increase in image quality.

  In the emulsion polymerization method, a thermoplastic resin emulsion produced by emulsion polymerization is mixed with a dispersion of toner particle components such as other colored fine particles. Toner particles are produced by slowly agglomerating while maintaining a balance, performing aggregation while controlling the particle size and particle size distribution, and simultaneously controlling the fusion and shape between the fine particles by heating and stirring. The toner particles of the present invention preferably have a volume average particle diameter of 4 to 10 μm, preferably 6 to 9 μm, from the viewpoint of high-definition image reproducibility.

  In the toner of the present invention, a post-treatment agent can be added and mixed from the viewpoint of imparting toner fluidity and improving cleaning properties, and is not particularly limited. Examples of such post-treatment agents include inorganic oxide fine particles such as silica fine particles, alumina fine particles, and titania fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, and strontium titanate and titanium. Inorganic titanate compound fine particles such as zinc oxide can be used, and it is possible to use single or different additives in combination. These fine particles are desirably used after being surface-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil, etc. from the viewpoints of environmental stability and heat-resistant storage stability. On the other hand, it is desirable to use 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass.

  The toner of the present invention can be used as a two-component developing toner used by mixing with a carrier, or as a one-component developing toner not using a carrier.

  As the carrier used in combination with the toner of the present invention, conventionally known carriers can be used as a carrier for two-component development. For example, a carrier made of magnetic particles such as iron or ferrite, such a magnetic material. A resin-coated carrier in which particles are coated with a resin, a binder-type carrier in which magnetic fine powder is dispersed in a binder resin, or the like can be used. Among these carriers, a silicone resin, a copolymer resin (graft resin) of an organopolysiloxane and a vinyl monomer, or a resin-coated carrier using a polyester resin can be used as a coating resin, such as toner spent. From the viewpoint, a carrier coated with a resin obtained by reacting an isocyanate with a copolymer resin of an organopolysiloxane and a vinyl monomer is particularly preferable from the viewpoint of durability, environmental stability, and spent resistance. . As the vinyl monomer, it is necessary to use a monomer having a substituent such as a hydroxyl group reactive with isocyanate. In addition, it is preferable to use a carrier having a volume average particle size of 20 to 100 μm, preferably 20 to 60 μm from the viewpoint of ensuring high image quality and preventing carrier fogging.

(Image forming method)
Next, an image forming method using the toner of the present invention will be described.
In the present invention, the image forming method is not particularly limited. For example, a method of forming a plurality of images on a photosensitive member and transferring them in a batch, a method of sequentially transferring images formed on the photosensitive member to a transfer belt, etc. are not particularly limited, but more preferably a plurality of images on the photosensitive member. This image is formed and transferred at once.

  In this method, the photosensitive member is uniformly charged and exposed according to the first image, and then the first development is performed to form a first toner image on the photosensitive member. Next, the photosensitive member on which the first image is formed is uniformly charged, and exposure according to the second image is given, and second development is performed to form a second toner image on the photosensitive member. Further, the photosensitive member on which the first and second images are formed is uniformly charged, exposed according to the third image, and subjected to the third development to form a third toner image on the photosensitive member. . Further, the photosensitive member on which the first, second, and third images are formed is uniformly charged to give exposure according to the fourth image, and the fourth development is performed, and the fourth toner image is formed on the photosensitive member. To form.

For example, a full color toner image is formed on the photosensitive member by developing the first time with yellow, the second time with magenta, the third time with cyan, and the fourth time with black toner.
Thereafter, the image formed on the photoreceptor is collectively transferred to an image support such as paper, and further fixed on the image support to form an image.

  In this method, the images formed on the photoconductor are collectively transferred to paper or the like to form an image. Therefore, unlike the so-called intermediate transfer method, the number of times of transfer that causes image disturbance is one. The image quality can be improved by using only once.

  As a method for developing on the photoreceptor, non-contact development is preferable because a plurality of developments are necessary. In addition, a method in which an alternating electric field is applied during development is also a preferable method.

  Further, as described above, the non-contact development method is preferable as the development method for forming a superimposed color image on the image forming body and transferring it collectively.

  The volume average particle size of the carrier that can be used as the two-component developer is 15 to 100 μm, more preferably 25 to 60 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  The carrier is preferably further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in the resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene / acrylic resin, silicone resin, ester resin, or fluorine-containing polymer resin is used. The resin for constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. For example, styrene / acrylic resin, polyester resin, fluorine resin, phenol resin, etc. are used. Can do.

  A preferred fixing method used in the present invention is a so-called contact heating method. In particular, typical examples of the contact heating method include a heat roll fixing method and a pressure heating fixing method in which fixing is performed by a rotating pressure member including a fixedly arranged heating body.

(image)
In image formation in which development, transfer, and fixing are performed using the toner of the present invention, the state of transfer to fixing is such that the toner of the present invention transferred onto a transfer material is discolored even after fixing. Without being adhered to the surface of the paper in a state of being dispersed in the toner particles.

  In the present invention, since the colored fine particles are dispersed in the toner particles as described above, the toner particles contain a high concentration of the dye, but the dye is not released to the surface of the toner particles (does not migrate). (1) Charge amount, which is a problem of a toner in which a dye obtained by dispersing or dissolving a dye in a thermoplastic resin (toner binder resin) as it is conventionally is exposed on the surface of the toner particles. (2) Large difference in charge amount between high temperature and high humidity and low temperature and low humidity (environment-dependent), (3) Colorant types such as cyan, magenta, yellow and black as in full color image recording When the pigments are used, the charge amount of each color toner varies, and the like can be wiped out. In addition, when heat-fixing to a transfer material, the dye as a colorant does not migrate out of the colored fine particles (exposed to the surface of the colored fine particles). There is no dye sublimation or oil contamination during fixing.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. In addition, unless otherwise indicated, "part" in an Example shows a "mass part".

Example 1
<Production of Color Toner-1 (Crushing Method)>
100 parts of a polyester resin, 8 parts by weight of a dye described in Table 1 (the dyes of the general formulas (1) to (3) or (5)), 4 parts by weight of a combined yellow dye described in Table 1 when used in combination with a yellow dye, Three parts of polypropylene were mixed, minced, pulverized, and classified to obtain a powder having an average particle size of 8.5 μm. Further, 100 parts of this powder and 1.0 part of silica fine particles (particle diameter 12 nm, hydrophobization degree 60) were mixed with a Henschel mixer to obtain color toners, that is, black toners 1 to 7 (pulverization method).

  To 10 parts by mass of the toner obtained above, 900 parts by mass of carrier iron powder (trade name: EFV250 / 400; manufactured by Nippon Iron Powder) was uniformly mixed to prepare a developer.

<Production of color toner-2 (polymerization method)>
Pure water: 20 g of a dye (general formula (1) to (3) or (5) or the like) shown in Table 1 is added to an aqueous solution in which 5 g of sodium dodecyl sulfate is dissolved in 200 ml. In combination, 10 g of the combined yellow pigment described in Table 1 was added, and an aqueous dispersion of a black colorant was prepared in advance by stirring and applying ultrasonic waves. Further, a surfactant (a solution in which 7.08 g of sodium dodecylbenzenesulfonate is dissolved in 2760 g of ion-exchanged water) is added while heating low molecular weight polypropylene (number average molecular weight = 3200), so that the solid content concentration is 30 mass. An emulsified dispersion emulsified in water so as to be% was prepared in advance.

  60 g of a low molecular weight polypropylene emulsion dispersion is mixed with the above pigment (dye) dispersion, and further, styrene monomer 220 g, n-butyl acrylate monomer 40 g, methacrylic acid monomer 12 g, and t-dodecyl mercaptan as a chain transfer agent. After adding 4 g, 5.1 g of a polymerization initiator (KPS: potassium persulfate), and 2000 ml of degassed pure water, emulsion polymerization was carried out by maintaining at 70 ° C. for 3 hours while stirring in a nitrogen stream. .

  To 1000 ml of the resulting dispersion of black dye-containing resin fine particles and resin particles, sodium hydroxide was added to adjust the pH to 7.0, 270 ml of a 2.7 mol% aqueous potassium chloride solution was added, and isopropyl was further added. 160 ml of alcohol and 9.0 g of polyoxyethylene octylphenyl ether having an average degree of polymerization of ethylene oxide of 10 are added after being dissolved in 67 ml of pure water, and the reaction (association) is carried out by maintaining at 75 ° C. for 6 hours. went.

  The obtained reaction solution is filtered, washed with water, dried and pulverized to obtain colored particles. The colored particles and 1.0 part of silica fine particles (particle diameter 12 nm, hydrophobization degree 60) are mixed with a Henschel mixer. By mixing, color toners, that is, black toners 8 to 32 (polymerization method) were obtained.

  To 10 parts by mass of the toner obtained above, 900 parts by mass of carrier iron powder (trade name: EFV250 / 400; manufactured by Nippon Iron Powder) was uniformly mixed to prepare a developer.

<Production of color toner-3 (polymerization method)>
<Preparation of colored fine particle dispersion>
(Preparation Example 1: Preparation of colored fine particle dispersion 33 (core type))
13.5 g of the polymer (P-1), 16.0 g of the dye 43 of the general formula (1) to (3) or (5) of the present invention, and 123.5 g of ethyl acetate were placed in a separable flask. After the inside was replaced with nitrogen gas, the dye was completely dissolved by stirring. Next, 238 g of an aqueous solution containing 8.0 g of Aqualon KH-05 (Daiichi Kogyo Seiyaku Co., Ltd.) was added dropwise and stirred, and then emulsified for 300 seconds using Clearmix W Motion CLM-0.8W (M Technique). did. Thereafter, ethyl acetate was removed under reduced pressure to obtain a core type colored fine particle dispersion 33 (core type) impregnated with the dye. The average particle diameter of the colored fine particles in the obtained colored fine particle dispersion was 48 nm. The average particle diameter is a volume average particle diameter measured using a Zetasizer manufactured by Malvern.

P-1: St / HEMA / SMA = 30/40/30
St: Styrene HEMA: 2-Hydroxyethyl methacrylate SMA: Stearyl methacrylate KH-05: Aqualon KH-05 (Daiichi Kogyo Seiyaku)
(Preparation Example 2: Preparation of colored fine particle dispersion 34 (core-shell type))
To the core-type colored fine particle dispersion 32 impregnated with the dye prepared in Preparation Example 1 above, 0.5 g of potassium persulfate is further added, heated to 70 ° C. with a heater, and then 10.0 g of The core shell type colored fine particle dispersion 34 (core shell type) was obtained by reacting for 5 hours while dropping methyl methacrylate. The average particle diameter of the colored fine particles in the obtained colored fine particle dispersion was 54 nm. The average particle diameter is a volume average particle diameter measured using a Zetasizer manufactured by Malvern.

(Preparation Examples 3 and 4: Preparation of colored fine particle dispersions 35 and 36 (core-shell type))
In the preparation of (Preparation Example 2: Colored Fine Particle Dispersion 34), the core-shell type coloring is similarly performed except that the dye 43 of the present invention is changed to the dye described in Table 1 and 8 g of the combined yellow dye described in Table 1 is added. Fine particle dispersions 35 and 36 were obtained. The average particle diameter of the colored fine particles in the obtained colored fine particle dispersion was 52 and 56 nm.

(Preparation of colored fine particle dispersion 37 (core shell type) (comparative example))
In the preparation of the above (Preparation Example 2: Colored fine particle dispersion 34), the same procedure was followed except that the dye 43 of the present invention was changed to the comparative dye (* 1 (10 g) + * 2 (10 g)) shown in Table 1. A core-shell type colored fine particle dispersion 37 was obtained. The average particle diameter of the colored fine particles in the obtained colored fine particle dispersion was 86 nm, and the distribution range was wide.

(Preparation of colored fine particle dispersion 38 (core-shell type) (comparative example))
In the preparation of (Preparation Example 2: Colored Fine Particle Dispersion 34), a core-shell colored fine particle dispersion was similarly prepared except that the same amount of the dye pigment 43 was changed to the comparative pigment (* 3) shown in Table 1. 38 was produced, but the dye separated from the resulting colored fine particle dispersion and settled.

<Preparation of colored particles>
(Preparation of thermoplastic resin (latex))
An interface in which 7.08 g of an anionic surfactant (sodium dodecylbenzenesulfonate: SDS) was previously dissolved in 2760 g of ion-exchanged water in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device. The activator solution (aqueous medium) was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. On the other hand, 72.0 g of a compound R represented by the following structural formula as a mold release agent was added to a monomer mixture composed of 115.1 g of styrene, 42.0 g of n-butyl acrylate, and 10.9 g of methacrylic acid, and 80 ° C. The monomer solution was prepared by heating and dissolving. The monomer solution (80 ° C.) is mixed and dispersed in the surfactant solution (80 ° C.) by a mechanical disperser having a circulation path to obtain emulsified particles (oil droplets) having a uniform dispersed particle size. A dispersion was prepared. Next, an initiator solution prepared by dissolving 0.84 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water is added to the dispersion, and the system is heated and stirred at 80 ° C. for 3 hours. Polymerization (first stage polymerization) was performed to prepare a latex. Next, an initiator solution prepared by dissolving 7.73 g of a polymerization initiator (KPS) in 240 ml of ion exchange water was added to this latex, and after 15 minutes, at 80 ° C., 383.6 g of styrene and n-butyl acrylate 140 A monomer mixture composed of 0.0 g, methacrylic acid 36.4 g, and tert-dodecyl mercaptan 13.7 g was added dropwise over 126 minutes. After completion of dropping, the mixture was heated and stirred for 60 minutes to perform polymerization (second stage polymerization), and then cooled to 40 ° C. to obtain a latex. This latex is referred to as “latex (1)”.

(Preparation of colored particles 33)
1250 g of the latex (1) obtained in the thermoplastic resin (latex) preparation example, 2000 ml of ion-exchanged water, and the colored fine particle dispersion 33 (dispersion) are mixed with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. The mixture was stirred in a 5-liter four-necked flask equipped with a device. After adjusting the internal temperature to 30 ° C., 5 (mol / liter) aqueous sodium hydroxide solution was added to this solution to adjust the pH to 10.0. Next, an aqueous solution in which 52.6 g of magnesium chloride hexahydrate was dissolved in 72 ml of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, temperature increase was started, and the system was heated to 90 ° C. over 6 minutes (temperature increase rate = 10 ° C./min). In this state, the particle size of the associated particles was measured with “Coulter Counter TA-II”, and when the volume average particle size reached 6.5 μm, an aqueous solution in which 115 g of sodium chloride was dissolved in 700 ml of ion-exchanged water was added. Then, the particle growth was stopped, and the fusion was continued by heating and stirring at a liquid temperature of 90 ° C. ± 2 ° C. for 6 hours. Then, it cooled to 30 degreeC on the conditions of 6 degreeC / min. Then, the associated particles are filtered from the dispersion of the associated particles, and after being redispersed in ion exchange water (PH = 3) in an amount 10 times the mass ratio with respect to the entire associated particles, After the process of filtering the associated particles from the washing water was repeated twice, the washing treatment was performed only with ion-exchanged water and dried with hot air at 40 ° C. to obtain colored particles. The colored particles thus obtained are referred to as “colored particles 33”.

(Preparation of colored particles 34 to 37)
In the production of the colored particles 33, the colored particles 34 to 37 were similarly produced except that the colored fine particle dispersion 33 was changed to the colored fine particle dispersions 34 to 37, respectively.

(Development of developer)
Hydrophobic silica (number average primary particle size = 12 nm, hydrophobicity = 68) is added to each of the colored particles 33 to 37 obtained as described above at a ratio of 1% by mass, and hydrophobic oxidation is performed. Titanium (number average primary particle size = 20 nm, degree of hydrophobicity = 63) was added at a ratio of 1.2% by mass and mixed by a Henschel mixer to obtain a color toner, that is, a black toner. These toners are referred to as “toner 33” to “toner 37” corresponding to the colored particles, respectively.

  Each of the toners obtained as described above and a ferrite carrier having a volume average particle diameter of 60 μm coated with a silicone resin were mixed to produce developers each having a toner concentration of 6% by mass.

For the developer produced above, Konica digital copying machine Konica “Sitios 7075” (corona charging, laser exposure, reversal development, electrostatic transfer, nail separation, blade cleaning, cleaning auxiliary brush roller adoption process as an evaluation machine. , A printing speed of 75 sheets / min) was used to produce a reflection image on paper by the following image forming method. The toner adhesion amount was evaluated in the range of 0.7 ± 0.05 (mg / cm ² ).

(Charging conditions)
Charger: Scorotron charger, initial charge potential of -750V
(Exposure conditions)
Set the exposure amount so that the potential of the exposed area is -50V.

(Development conditions)
DC bias; -550V
(Transfer conditions)
Transfer pole; corona charging method (cleaning conditions)
A cleaning blade having a hardness of 70 °, a rebound resilience of 65%, a thickness of 2 (mm), and a free length of 9 mm was brought into contact with the cleaning portion by a weight load method so that the linear pressure was 18 (N / m) in the counter direction.

  The obtained image was evaluated for color tone, degree of blackening, light resistance and fine line reproducibility.

<Color tone>
Regarding the color tone, the average score of the four-stage evaluation was calculated by visual evaluation with 10 monitors for each sample. If the average score is 2.3 or more, there is no practical problem. The evaluation results are shown in Table 1 below.
3 points: feels dark black 2 points: feels black 1 point: feels yellowish, reddish, blueish, etc. 0 point: cannot be recognized as black <Blackening degree>
The degree of blackening was measured by measuring the neutral reflection density with a PDA-65 densitometer manufactured by Konica Corporation. If the concentration is 1.4 to 1.5 or more, there is virtually no problem.

<Light resistance>
For light resistance, after measuring the image density Ci immediately after recording, the image was irradiated with xenon light (85,000 lux) for 5 days using a weather meter (Atlas C.165), and the image density again. Cf was measured, and the dye residual ratio ({(Ci-Cf) / Ci} × 100%) was calculated from the difference in image density before and after the xenon light irradiation and evaluated. The image density was measured using a reflection densitometer (X-Rite 310TR). The evaluation results are shown in Table 1 below. In Table 1 below,
When the dye residual ratio is 95% or more
○ If it is 90% or more and less than 95%
△ 80% or more and less than 90%
× less than 80%
As shown.

<Reproducibility of thin lines>
For fine line reproducibility, the line width of a line image corresponding to an image signal of 2 dot lines was measured by a print evaluation system “RT2000” (manufactured by Yarman). If the line width of the first formed image and the line width of the 20000th formed image are both 200 μm or less and the change in the line width is less than 10 μm, it can be said that fine line reproducibility is not a problem.
◎: Change in line width is 7 μm or less ○: Change in line width exceeds 7 μm but less than 10 μm ×: Change in line width is 10 μm or more <Ozone gas resistance>
For ozone gas resistance, the photo glossy paper on which the image is formed is left in a box where the ozone gas concentration is set to 0.5 ppm for 7 days, and the image density before and after being left under ozone gas is measured using a reflection densitometer (X-Rite 310TR). And measured as a residual ratio of the dye. The reflection density was measured at three points near 1.0. The ozone gas concentration in the box was set using an ozone gas monitor (model: OZG-EM-01) manufactured by APPLICS.
A: When the dye residual ratio is 80% or more at any point, ○: 1 or 2 points is less than 80% ×: Less than 70% at all points. “◯” or more is a practical level.

  The results are shown in Table 1.

CB: Carbon black YA: C.I. I Solvent Yellow 19
* 1: Phthalocyanine C.I. I Pigment Red 27
C. I Pigment Yellow 33
* 2: Perylene colorant compound (1)

* 3: Black organic pigment (chromofine black A-1103 (primary particle size D ₅₀ 30 (nm)) manufactured by Daiichi Seika Kogyo Co., Ltd.)
* 4: Azo dye (a-2) described in JP-A No. 2004-231945

  * 1: Black toner (pulverization method) produced in Example 1 of JP-A-5-27481 (Patent Document 5).

  * 2: Black toner produced in Example 1 of JP-A-2003-316072 (Patent Document 6) (pulverization method).

  As can be seen from Table 1, the black toner for electrophotography of the present invention can faithfully reproduce the color by using the black toner using the coloring matter of the general formulas (1) to (3) or (5) of the present invention ( It exhibits a preferable color tone close to true black) and the degree of blackening, and is suitable for use as a black toner. Moreover, it turns out that a more preferable color tone is obtained by using together yellow pigment | dye, especially the yellow pigment | dye of general formula (Y-1)-(Y-9). Furthermore, since the light resistance and ozone gas resistance are good, it is possible to provide an image that can be stored for a long time. It can also be seen that the degree of blackening and color tone, particularly the reproducibility of fine lines, is improved by using the polymerization method as compared with the pulverization method. The black toner for electrophotography of the present invention was at a level with no problem with respect to heat resistance, chargeability, and offset resistance.

FIG. 2 is a schematic diagram illustrating an example of a non-contact developing type developing unit that can be suitably used in the present invention. Schematic which shows an example of a sequential transfer system. Schematic which shows an example of a batch transfer system. FIG. 3 is a diagram schematically showing a cross section of colored particles (toner particles) in which colored fine particles are dispersed in a thermoplastic resin. It is the figure which represented typically the cross section of the colored fine particle of the core shell structure formed by coat | covering an inside (core) with outer shell resin (shell).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Developer carrying body 2A Developing sleeve 2B Magnet 3 Two-component developer containing toner of the present invention 4 Developer layer regulating member 5 Development area 6 Developer layer 7 Power source 11 Charger 12 Developer (development unit)
DESCRIPTION OF SYMBOLS 13 Cleaning unit 14 Photosensitive drum 15 Transfer drum 16 Conveyance unit 17 Adsorption electrode 18 Transfer electrode 19 Peeling electrode 20 Electrode removal 21 Conveying part 41 Colored particle (toner particle)
42 Thermoplastic resin 43 Colored fine particles 44 Resin 45 Dye 46 Inside (core)
47 Outer shell resin (shell)

Claims (7)

In a black toner for electrophotography obtained by fusing resin particles and colorant-containing resin particles at least in an aqueous medium, the colorant contained in the colorant-containing resin particles is represented by the following general formula (1). A black toner for electrophotography, comprising at least one oil-soluble dye.
General formula (1)
A- (N = N- _Bm ) _n- N = N-C
[Wherein, A, B and C each independently represent an optionally substituted aromatic group or heterocyclic group, at least one represents a heterocyclic group, and m and n are 1 or 2; is there. ] The black toner for electrophotography according to claim 1, wherein the oil-soluble dye represented by the general formula (1) is represented by the following general formula (2).

[Wherein, A and B each independently represents an optionally substituted aromatic group or heterocyclic group, and B ₁ and B ₂ each represent ═CR ₁ — and —CR ₂ ═, Or one of them represents a nitrogen atom and the other represents = CR ₁ -or -CR ₂ =. G, R ₁ and R ₂ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, heterocyclic oxy Carbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (anilino group, heterocyclic ring) Amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, nitro group, alkyl or arylthio group, Heterocycle It represents a thio group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, and each group may be further substituted. R ₅ and R ₆ each independently represents a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group or sulfamoyl group. Each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. R ₁ and R ₅ , or R ₅ and R ₆ may be bonded to form a 5- to 6-membered ring. ] 2. The black toner for electrophotography according to claim 1, wherein the oil-soluble dye represented by the general formula (1) is represented by the following general formula (3).

[Wherein, A represents an optionally substituted aromatic group or heterocyclic group, and B ₁ and B ₂ each represent ═CR ₁ — and —CR ₂ ═, or one of them represents The nitrogen atom and the other represents = CR ₁ -or -CR ₂ =. G, R ₁ , R ₂ , R ₇ and R ₈ are each independently a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carbamoyl group, alkoxycarbonyl group, aryloxy Carbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (Including anilino group and heterocyclic amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, heterocyclic sulfonylamino group, nitro group , Alkyl or arylthio Represents an o group, a heterocyclic thio group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, and each group may be further substituted. R ₅ and R ₆ each independently represents a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group or sulfamoyl group. Each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. R ₁ and R ₅ , or R ₅ and R ₆ may be bonded to form a 5- to 6-membered ring. ] The black toner for electrophotography according to claim 1, wherein the oil-soluble dye represented by the general formula (1) is represented by the following general formula (5).

[Wherein, A represents an optionally substituted aromatic group or heterocyclic group, and R ₁ and R ₂ each independently represents a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a hetero group, Ring group, cyano group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy Group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (including anilino group and heterocyclic amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, Alkyl or arylsulfonylamino group, heterocyclic sulfoni Represents a ruamino group, a nitro group, an alkyl or arylthio group, a heterocyclic thio group, an alkyl or arylsulfonyl group, a heterocyclic sulfonyl group, an alkyl or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, and each group is further substituted. May be. R ₃ and R ₄ are each independently a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group, or sulfamoyl group Represents. R ₅ and R ₆ each independently represents a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or arylsulfonyl group or sulfamoyl group. Each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. R ₁ and R ₅ , or R ₅ and R ₆ may be bonded to form a 5- to 6-membered ring. Z ₁ represents an electron-withdrawing group having a Hammett's substituent constant σp value of 0.20 or more. ] The oil-soluble dye A represented by the general formulas (1) to (3) or (5) is represented by the following general formulas (Cp-1) to (Cp-9). The black toner for electrophotography of any one of -4.

[Wherein, R _{20 to} R ₃₅ represent a hydrogen atom or a substituent, and are bonded to an azo group at the * mark. ] At least one oil-soluble dye represented by the general formulas (1) to (3) or (5) and at least one yellow dye represented by the following general formulas (Y-1) to (Y-10) The black toner for electrophotography according to any one of claims 1 to 5, comprising:

[Wherein R ₄₁ , R ₄₂ , R ₄₂ ′ R ₄₄ , R ₄₈ and R ₄₈ ′ are each independently hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carbamoyl. Group, alkoxycarbonyl group, aryloxycarbonyl group, heterocyclic oxycarbonyl group, acyl group, hydroxy group, alkoxy group, aryloxy group, heterocyclic oxy group, silyloxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, Aryloxycarbonyloxy group, amino group (including anilino group and heterocyclic amino group), acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkyl or arylsulfonylamino group, Heterocyclic sulfonylamino group, nitro group, alkyl And arylthio groups, heterocyclic thio group, an alkyl- or arylsulfonyl group, heterocyclic sulfonyl group, an alkyl- or arylsulfinyl group, a heterocyclic sulfinyl group, or a sulfamoyl group, may each group further substituted. R ₄₃ represents an aliphatic group, and R ₄₇ , R ₄₇ ′ and R ₄₉ represent an aliphatic group, an aromatic group, a heterocyclic group or an acyl group. W represents —OH or —NR ₄₅ R ₄₆ . R ₄₅ , R ₄₆ , R ₄₅ ′ and R ₄₆ ′ are each independently a hydrogen atom, aliphatic group, aromatic group, heterocyclic group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkyl or It represents an arylsulfonyl group or a sulfamoyl group, and each group may further have a substituent. However, R ₅ and R ₆ are not simultaneously hydrogen atoms. p represents an integer of 0 to 5, q represents an integer of 0 to 2, and r represents an integer of 0 to 4. ] In an electrophotographic toner comprising a thermoplastic resin in which colored fine particles containing a resin having a composition different from that of the thermoplastic resin and a colorant are dispersed, the colorant is represented by the general formulas (1) to ( The black toner for electrophotography according to claim 1, comprising at least one oil-soluble dye represented by 3) or (5).

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