JP3028463B2 - Positively chargeable toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positively chargeable toner among electrostatic image developing toners used for electrophotography, electrostatic recording, electrostatic printing and the like.

[0002]

2. Description of the Related Art Conventionally, as a method of developing an electrostatic image using toner in electrophotography, electrostatic recording, electrostatic printing, and the like, a method of developing a toner by using a carrier (two-component developing method) or a charging blade (single-component developing) Method), the toner is charged by friction, and an electrostatic image having the opposite polarity to that of the charged toner is visualized. The developed toner is transferred onto a support such as paper or polyester film, and fixed using a contact heating type fixing device (for example, a method described in JP-A-4-70688 and JP-A-4-12558). Is widely adopted. In the fixing method using this fixing device, it is desirable that the minimum fixing temperature is low (low-temperature fixing property) and that the temperature at which hot offset occurs on the fixing device surface is high (hot offset resistance). Further, since heat is generated from a fixing device or the like in the apparatus, heat resistance storage stability must be satisfied so that the toner is not aggregated by heat and the fluidity is not deteriorated. When the toner is charged by the above method,
In the component development method, it is required that the toner does not deteriorate even when mixed with a carrier for a long time. In the one-component development method, it is required that the toner does not adhere to the charging blade. further,
The charged amount of the charged toner is required to be appropriate, and it is desirable that the charged amount between the toner particles is uniform (the charge amount distribution is narrow). Further, from the viewpoint of color reproducibility, it is desired that the toner after the fixing is smooth (smoothness) and the transparency of the toner is high.

Hitherto, polystyrene resins, styrene acrylic resins, polyester resins, and epoxy resins have been generally used as the toner binder among the components of the dry toner. Among them, styrene acrylic resins are preferred from the viewpoints of chargeability, pulverizability and cost. However, polyester resins are widely used from the viewpoints of low-temperature fixability, durability and smoothness.
On the other hand, a charge control agent has conventionally been used for the purpose of controlling the chargeability of the toner. Among the charge control agents, there are known positively chargeable ones such as a nigrosine dye, a triphenylmethane derivative, and a quaternary ammonium salt compound. Therefore, when low-temperature fixability and durability are important as in a high-speed copying machine, and when it is important that toner hardly adheres to a blade as in a printer, it is better to use a polyester resin as the toner binder. Advantageously, polyester resins are widely used in negatively chargeable toners. However, a toner using a polyester resin has a strong negative charge property of the toner binder itself, so it is difficult to make the toner charge a positive charge, and any of the polyester-based positive charge toners using the charge control agent is There is a problem that the charge amount is insufficient and a large amount of oppositely charged toner particles are present (the charge amount distribution is wide). As a result, when the toner is developed using the present toner, a lot of fog occurs. However, there is a problem that image quality is deteriorated during long-term copying. In addition, when the above-described conventional charge control agent is used for a color toner, the nigrosine dye and the triphenylmethane derivative are colored, and adversely affect the color tone. Although the quaternary ammonium salt compound is colorless, it has a problem that the transparency of the toner is deteriorated due to poor dispersibility. On the other hand, when a styrene acrylic resin-based toner binder is used as the toner binder, there is no charging problem, but the low-temperature fixability, durability, and smoothness are insufficient as described above.

In order to improve the above-mentioned problems, from the viewpoint of improving the chargeability when a polyester resin is used, a polyester resin using a block copolymer of poly (t-butylaziridine) and a polyester as a charge control agent. Toner (JP-A-3-15079) and the like have been proposed. On the other hand, from the viewpoint of improving the low-temperature fixability of a styrene acrylic resin, many methods have been proposed for increasing the molecular weight distribution of the resin. As a method for broadening the molecular weight distribution, a method using a crosslinking agent (JP-A-61-2155)
No. 58) and a binder having two peaks in a high molecular weight portion and a low molecular weight portion (JP-B-63-32180, JP-B-63-32382).

[0005]

However, although the problem of color reproducibility in the case of a color toner has been solved in the positively chargeable toner disclosed in the above, a large amount of a charge control agent is added to the toner. Because of the necessity, the low-temperature fixability and durability inherent in the polyester-based toner binder cannot be sufficiently exhibited, and it is not economical. Further, in the method of improving the low-temperature fixability using a styrene acrylic resin disclosed in and,
The durability and the smoothness are insufficient, and it cannot be said that it is satisfactory for use in a high-speed copying machine, a one-component developing system printer and a color copying machine.

[0006]

Means for Solving the Problems The present inventors have intensively studied to develop a positively chargeable toner having excellent durability, low-temperature fixability, and excellent chargeability, and reached the present invention. That is, the present invention relates to a toner for developing an electrostatic image containing a toner binder (α), a charge control agent (β) and a coloring material (γ), wherein the toner binder (α) has a weight average molecular weight of 200,000 to 3,000,000. (1) a resin having a nitrile group containing 5 to 40% by weight of (meth) acrylonitrile as a constituent unit, and a weight average molecular weight of 1,000
100,000 to 100,000 (meth) acrylonitrile 5 to 40% by weight
It contains a resin (2) containing a nitrile group contained as a constituent unit, and further contains a polymer (A) composed of a monomer unit having a quaternary ammonium group as a charge control agent (β). Positively chargeable toner.

The nitrile group-containing resin (1) constituting the toner binder (α) used in the present invention includes a nitrile group-containing vinyl polymer and a nitrile group-containing polyester resin. Examples of the nitrile group-containing vinyl polymer include acrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-propylacrylonitrile, α-butylacrylonitrile, α-isobutylacrylonitrile, α-cyano-3-hydroxycinnamic acid, α-cyano-4 -A polymer of a vinyl monomer containing a nitrile group such as hydroxycinnamic acid, and a copolymer of these with other vinyl monomers. As the nitrile group-containing polyester resin, α-cyano-3
And polycondensates of a component containing a hydroxyl group and a carboxyl group, such as -hydroxycinnamic acid and α-cyano-4-hydroxycinnamic acid, with other glycol components and dicarboxylic acid components. Of these (1), preferred is a nitrile group-containing vinyl polymer, and more preferred is a copolymer (1-1) of (meth) acrylonitrile and another vinyl monomer.

Other vinyl monomers copolymerized with (meth) acrylonitrile include styrene monomers such as styrene, α-methylstyrene, p-methoxystyrene, p-hydroxystyrene and p-acetoxystyrene;
Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid 2
An alkyl (meth) acrylate having 1 to 18 carbon atoms in an alkyl group such as ethylhexyl, lauryl (meth) acrylate, stearyl (meth) acrylate; a hydroxyl group-containing (meth) acrylate such as hydroxyethyl (meth) acrylate; Dimethylaminoethyl (meth)
Amino group-containing (meth) acrylates such as acrylate and diethylaminoethyl (meth) acrylate; dienes such as butadiene and isoprene; vinyl esters such as vinyl acetate; vinyl ethers such as vinyl ethyl ether; aliphatics such as α-olefin and isoprene Hydrocarbon vinyl; (meth) acrylic acid, maleic anhydride,
Examples include unsaturated carboxylic acids such as itaconic anhydride and anhydrides thereof. Of these other copolymerizable vinyl monomers, styrene monomers, alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl group, and unsaturated carboxylic acids are preferred, and styrene is particularly preferred. Therefore, a particularly preferred copolymer (1-1) of (meth) acrylonitrile and another vinyl monomer is a copolymer of (meth) acrylonitrile and styrene, (meth)
It is a copolymer of acrylonitrile, styrene and small amounts of other vinyl monomers.

The ratio of each constituent monomer of the copolymer (1-1) is described below. (Meth) acrylonitrile is usually 3 to 100% by weight, preferably 3 to 60% by weight, more preferably 5 to 40% by weight. It is. Styrene is usually 0
９７97% by weight, preferably 30-95% by weight, more preferably 40-80% by weight. Other vinyl monomers are usually 0 to 97% by weight, preferably 0 to 50% by weight,
More preferably, it is 3 to 20% by weight.

In order to increase the molecular weight during the polymerization of the copolymer (1-1), a polyfunctional monomer having at least two polymerizable double bonds is added in an amount that does not cause gelation (usually 0.1%). % By weight). Polyfunctional monomers include di- or polyvinyl compounds (eg, divinylbenzene, ethylene glycol diacrylate,
1,6-hexanediol diacrylate, divinyltoluene) and the like. Of these, preferred are divinylbenzene, 1,6-hexanediol diacrylate, divinyltoluene) and the like.

The weight average molecular weight of (1) is usually 100,000 to 1
100,000, preferably 150,000 to 5,000,000, more preferably 200,000 to 3,000,000. When the weight average molecular weight of (1) is 100,000 or less, the hot offset resistance deteriorates. 1
If it is more than 10,000,000, kneading becomes difficult during the production of the toner, and the dispersibility of the coloring material and the charge control agent deteriorates.
The number average molecular weight of (1) is usually 30,000 to 3,000,000, preferably 50,000 to 1.5,000,000, more preferably 70,000 to 1,000,000. The glass transition point (Tg) of (1) is usually 30 to 100.
° C, preferably 35 to 90 ° C, more preferably 40 to 90 ° C.
85 ° C. If the Tg is lower than 30 ° C., the heat-resistant storage stability of the toner is deteriorated.

In the toner binder used in the present invention, the content of (1) is usually 3 to 50% by weight, preferably 5 to 40% by weight, and more preferably 7 to 30% by weight.
It is. When the content of (1) is less than 3% by weight, the hot offset resistance becomes poor. If it exceeds 50% by weight, the pulverizability during the production of the toner is deteriorated, and the low-temperature fixability is deteriorated.

As another resin (2) constituting the toner binder (α) used in the present invention, a resin (2-1) containing a nitrile group, a polyester resin (2-2), and a styrene acrylic resin (2) -3), polyurethane resin (2-
4), epoxy resin (2-5), polyamide resin (2-6)
And the like. Of these, preferred is (2)
-1), (2-2), (2-3) and mixtures thereof, and particularly preferred are (2-1), (2-2) and mixtures thereof.

Examples of the resin (2-1) containing a nitrile group include those having the same composition as in the above (1). Also,
The same applies to the preferred composition.

Examples of the polyester resin (2-2) include polycondensates of polyhydric alcohols and polybasic acids (polybasic acids, anhydrides, lower esterified products). Examples of the polyhydric alcohol include a dihydric alcohol and a trihydric or higher alcohol. Preferred among these are dihydric alcohols and mixtures of these with small amounts of trihydric or higher alcohols. Examples of the polybasic acids include dibasic acids and tricarboxylic or higher polycarboxylic acids. Preferred among these are dibasic acids and mixtures of these with small amounts of trivalent or higher polycarboxylic acids.

Examples of the divalent alcohol include aliphatic glycols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butanediol, neopentyl glycol and 1,6-hexanediol. Aromatic glycols such as hydroquinone, catechol, resorcin, pyrogallol, bisphenols (bisphenol A, bisphenol AD, bisphenol F, bisphenol S, etc.); alicyclic glycols such as 1,4-cyclohexanedimethanol, hydrogenated bisphenols And alkylene oxides thereof (ethylene oxide,
Propylene oxide) and the like.
Of these, preferred are alkylene oxide adducts of aliphatic glycols, alicyclic glycols, and aromatic glycols, and mixtures of two or more thereof. Particularly preferred are alkylene oxides of bisphenol A. Adducts and mixtures thereof with one or more other aromatic glycols, aliphatic glycols and alicyclic glycols. Examples of dibasic acids include succinic acid, maleic acid, fumaric acid, itaconic acid, azelaic acid, mesaconic acid, citraconic acid, sebacic acid, glutaconic acid, adipic acid, malonic acid, phthalic acid, isophthalic acid, terephthalic acid, and cyclohexanedicarboxylic acid. , Nadic acid, methylnadic acid, octylsuccinic acid, dodecenylsuccinic acid and the like, and anhydrides and lower alkyl (methyl, ethyl) esters of these acids. In addition, polymerized fatty acids such as dimer and trimer of linoleic acid can be used. The dibasic acids can be used alone or as a mixture of two or more. Among these, alkyl or alkenyl (C 4 to C 1) represented by succinic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, octylsuccinic acid and dodecenylsuccinic acid.
8) Succinic acid is preferred. Specific examples of polycarboxylic acids having 3 or more valences include aliphatic polycarboxylic acids having 7 to 20 carbon atoms (1,2,4-butanetricarboxylic acid, 1,2,5
-Hexanetricarboxylic acid and the like); an alicyclic polycarboxylic acid having 9 to 20 carbon atoms (such as 1,2,4-cyclohexanetricarboxylic acid); and an aromatic polycarboxylic acid having 9 to 20 carbon atoms (1,2,4- Benzenetricarboxylic acid, 1,2,2
5-benzenetricarboxylic acid, pyromellitic acid, etc.);
And anhydrides and lower alkyl (methyl, butyl, etc.) esters thereof. Among them, preferred are aromatic polycarboxylic acids having 9 to 20 carbon atoms and anhydrides and lower alkyl esters thereof. Specific examples of the trihydric or higher alcohols include aliphatic polyhydric alcohols having 3 to 20 carbon atoms (sorbitol, 1,4-sorbitan, pentaerythritol, trimethylolethane, trimethylolpropane, glycerol, etc.); To 20 aromatic polyhydric alcohols (such as 1,3,5-trihydroxylmethylbenzene); and their alkylene oxide adducts; oxyalkylene ethers of novolak-type phenolic resins; Oxyalkylene ethers of heterocyclic compounds having active hydrogen and the like can be mentioned. Among them, carbon number 3
Preferred are aliphatic polyhydric alcohols of 20 to 20, oxyalkylene ethers of novolak type phenol resins, and oxyalkylene ethers of heterocyclic compounds having two or more active hydrogens in the molecule.

The molar ratio of the polyhydric alcohol to the polybasic acid is usually 0.5 to 2, preferably 0.6 to 1.5,
More preferably, it is 0.7 to 1.4. The acid value of (2-2) is usually 0.2 to 200, preferably 0.5 to 150.
mg KOH / g. The hydroxyl value is usually 0.2
~ 200, preferably 0.5-150 mgKOH / g
It is.

Further, a monoalcohol or a monocarboxylic acid may be used in combination for blocking the terminal carboxylic acid or terminal hydroxyl group, or for adjusting the molecular weight or controlling the reaction. Specific examples of monoalcohols and monocarboxylic acids include monocarboxylic acids such as benzoic acid, paraoxybenzoic acid, toluenecarboxylic acid, salicylic acid, acetic acid, propionic acid, and stearic acid; benzyl alcohol, toluene-4-methaneanol and cyclohexane Monoalcohols such as methanol are mentioned.

As the styrene acrylic resin (2-3),
Copolymers of styrene and an alkyl (meth) acrylate having an alkyl group of 1 to 18 carbon atoms, and copolymers of these with a small amount of another vinyl monomer, and the like, are mentioned.

Examples of the polyurethane resin (2-4) include polyaddition products of polyisocyanate and polyol. Examples of the polyisocyanate include aromatic polyisocyanates {tolylene diisocyanate (TDI), dimethyldiphenylmethane diisocyanate (MDI), modified MDI, naphthylene diisocyanate, xylylene diisocyanate, etc.}; polymers of aromatic polyisocyanates (TDI, MDI, etc.). NC, dimer, trimer, etc.)
O-terminal urethane prepolymer {low molecular polyol (such as trimethylolpropane) and excess aromatic isocyanate (TDI) etc.}; aliphatic polyisocyanate {tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate (IPDI),
Dicyclohexylmethane diisocyanate, etc .; and multimers of aliphatic polyisocyanates (eg, trimers of IPDI). Of these, TDI, MDI and IPDI are preferred. Examples of the polyol include the above-described dihydric alcohols and trihydric or higher alcohols. As other polyol components, a molecular weight of 500 to
3000 polyether diols (polytetramethylene glycol, polyethylene glycol, polypropylene glycol, etc.); polyester diols having a molecular weight of 500 to 3000 dicarboxylic acid (adipic acid, maleic acid, phthalic acid, etc.) and low molecular diols (ethylene glycol, diethylene glycol 1,4-butanediol, 1,6-hexanediol, etc.). Of these, an alkylene oxide adduct of bisphenol A is preferred.

The molar ratio of the polyisocyanate to the polyol is usually 0.5 to 1.5, preferably 0.6 to 1.5.
To 1.4, more preferably 0.7 to 1.3. Also, to seal the terminal isocyanate and terminal OH,
Monoalcohols and monoisocyanates can be used in combination.

Examples of the epoxy resin (2-5) include bisphenol A type, bisphenol F type epoxy resin, novolak type epoxy resin, polyphenol type epoxy, polyglycidyl type epoxy resin, and these epoxy resins and the dicarboxylic acid and / or Reaction products with a monocarboxylic acid can be mentioned.

Examples of the polyamide resin (2-6) include polycondensates of divalent or higher carboxylic acids and divalent or higher amines, and if necessary, monocarboxylic acids and / or monoamines. Specific examples of the divalent or higher carboxylic acids include polymerized fatty acids obtained by polymerizing unsaturated fatty acids such as oleic acid and linoleic acid, which are generally called dimer acids, and the above-mentioned divalent carboxylic acids. Specific examples of divalent or higher amines include aliphatic polyamines (ethylenediamine, diethylenetriamine, triethylenetetramine, 1,2-diaminopropane, 1,3-diaminopropane, hexamethylenediamine, etc.); alicyclic polyamines (iso- Polondiamine, cyclohexylenediamine, etc.); aromatic polyamines (xylylenediamine, diaminodiphenylmethane, etc.). Of these, aliphatic polyamines are preferred. Specific examples of the monocarboxylic acid include the above-described monocarboxylic acids, and other examples include mixed fatty acids (palm oil fatty acid, tall oil fatty acid, soybean oil fatty acid, tallow fatty acid, and the like). Specific examples of the monoamine include n-propylamine, stearylamine, oleylamine, and monoethanolamine. The ratio of the carboxylic acid to the polyamine is such that the carboxyl group equivalent / amino group equivalent is usually 0.5 to 1.5, preferably 0.6 to 1.4, and more preferably 0.7 to 1.3.

The weight average molecular weight of (2) is usually from 1,000 to
100,000, preferably 1500 to 50,000, more preferably 2
000 to 30,000. When the weight average molecular weight is less than 1,000, Tg is lowered, and the heat resistance storage stability of the toner is deteriorated. If it exceeds 100,000, the low-temperature fixability deteriorates. (2)
Tg is usually 20 to 85 ° C, preferably 35 to 80 ° C,
More preferably, it is 45 to 75 ° C. If the Tg is lower than 20 ° C., the heat-resistant storage stability of the toner becomes poor, and if the Tg exceeds 85 ° C., the low-temperature fixability deteriorates.

Hereinafter, a method for synthesizing the toner binder (α) used in the present invention will be exemplified. The method of blending (1) and (2) is not particularly limited, but a method of kneading the two in a heated and molten state, a method of devolatilizing after blending in the presence of a solvent, and a method of polymerizing the other in the presence of one And the like. As the polymerization method (1), known methods such as solution polymerization, bulk polymerization, and suspension polymerization can be selected. Also,
Known polymerization initiators can be used. The polymerization method (2) can be synthesized by a known solution polymerization method in a solvent such as toluene or xylene when (2) is (2-1) or (2-3). (2-2) and (2-6) may be used in the presence of a catalyst (for example, dibutyltin oxide, stannous oxide and tetrabutyltitanate) if necessary at 150 ° C to 300 ° C.
To obtain a polycondensation reaction. (2-4), (2-5)
Can be obtained by a polyaddition reaction according to a conventional method.

In the present invention, the polymer (A) comprising a monomer unit having a quaternary ammonium group constituting the charge control agent (β) is a polymer (A1) represented by the following general formula (I): And a polymer of a quaternary ammonium group-containing vinyl monomer (A2). Of these, preferred is (A1). General formula (I):

[0027]

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Wherein R 1 is hydrogen or a C 1 -C 21 hydrocarbon group, and R 2 and R 3 are each independently hydrogen or C 1
It may be a hydrocarbon group of -C8, or R2 and R3 may be mutually connected to form an aromatic ring. R4 represents a C1 to C12 alkylene group which may contain an ether bond in the group, X- represents an anion, and n represents an integer of 2 to 100. )

In the general formula (I), the C1-C21 hydrocarbon group of R1 includes an alkyl group (methyl, ethyl, butyl, cyclohexyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl) Group, hexadecyl group, heptadecyl group, etc.), alkenyl group (undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, etc.), alkylphenyl group (pentylphenyl group, hexylphenyl group, heptylphenyl) Group, octylphenyl group, nonylphenyl group,
Decylphenyl group, undecylphenyl group, etc.). Of these, preferred are C11 to C21 alkyl groups and alkenyl groups, and particularly preferred are C11 to C21 alkyl groups.

R 2 and R 3 are hydrogen or a C 1 -C 8 hydrocarbon group. Examples of the hydrocarbon group include alkyl groups (methyl, ethyl, propyl, butyl, hexyl,
Octyl group and the like), aryl group (phenyl group and the like), aralkyl group (benzyl group and the like) and the like.
Examples of the aromatic ring in which R2 and R3 are linked to each other include a benzo group. Preferred of these are hydrogen,
A methyl group, an ethyl group and a benzo group.

Among R 4, the C 1 -C 12 alkylene group includes a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, an octamethylene group, and a dodecamethylene group. Examples of the alkylene group C1~C12 containing an ether bond among _{R4, -CH 2 CH 2 OCH 2} CH 2 - -CH 2 CH 2 OCH 2 OCH 2 CH 2 - -CH 2 CH 2 OCH 2 CH 2 OCH 2 CH ₂ − and the like. Among these, preferred are an ethylene group, trimethylene group, tetramethylene group, hexamethylene group, dodecamethylene _{group, -CH 2 CH 2 OCH 2 CH} 2
- and _{-CH 2 CH 2 OCH 2 OCH 2} CH 2 - is preferable, and more preferable ones are a trimethylene group, tetramethylene group, hexamethylene group, dodecamethylene group and,
—CH ₂ CH ₂ OCH ₂ CH ₂ —.

As the anion of X-, halogen ion (chlorine ion, bromine ion, iodine ion, etc.), sulfate ion, nitrate ion, phosphate ion, sulfonate ion (p-ion
Toluenesulfonate, methylsulfonate, hydroxynaphthosulfonate, etc.), borate (tetrafluoroborate, tetraphenylborate, metaborate, metaborate-glycerin complex, etc.), oxoate (Molybdate ion,
And carboxylate ions (such as acetate ions). Among these, preferred are a halogen ion, a sulfonate ion, a borate ion and an oxo acid ion.

The average degree of polymerization n of (A1) is usually from 2 to 10.
0, preferably 3 to 50, more preferably 4 to
30.

Examples of the quaternary ammonium group-containing vinyl monomer constituting (A2) include quaternized products of a tertiary amino group-containing vinyl monomer with a quaternizing agent. Examples of tertiary amino group-containing vinyl monomers include aminoalkyl (meth) acrylamides [dimethylaminopropyl (meth) acrylamide and the like], aminoalkyl (meth) acrylates [dimethylaminoethyl (meth) acrylate, morpholinoethyl (meth) Acrylate etc.],
And vinyl pyridines (eg, vinyl pyridine). Examples of the quaternizing agent include alkyl halides (eg, methyl chloride, butyl chloride, lauryl chloride, benzyl chloride), dialkyl sulfates (eg, dimethyl sulfate), and alkyl tosylates (eg, methyl tosylate). Further, the counter ion of the quaternary compound can be replaced with a tetraphenyl borate ion, a terafluoroborate ion, a molybdate ion, a toluenesulfonic acid ion, an acetate ion, or the like. (A2)
May be a homopolymer of the above quaternary ammonium salt group-containing vinyl monomer, or may be a copolymer with another copolymerizable vinyl monomer. Other vinyl monomers include styrene, alkyl (meth) acrylate [methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, etc.].

Further, as the charge control agent (β) in the present invention, a part or all of the polymer (A)
A polymer in which a styrene-based polymer portion (b) is grafted or block-bonded to a polymer portion (a) having the same configuration as that of (A) can also be used.
Replacing (A) with (AB) is particularly preferable in that the dispersed particle size in the toner (a) can be easily reduced and the charge amount distribution can be sharpened. Examples of (AB) of the present invention include copolymers described in JP-A-3-15079 and JP-A-5-165259 by the present inventors. Among (A) constituting (a), preferable ones are the same as those described in the above (A1) and (A2). Preferred as the styrene polymer portion (b) are a homopolymer of styrene, a copolymer of styrene and an alkyl (meth) acrylate having 1 to 18 carbon atoms in an alkyl group, and a copolymer of styrene and (meth) acrylonitrile. Styrene and butadiene, and copolymers of these with small amounts of other copolymerizable monomers. The copolymerization ratio of styrene and other monomers is usually 40 mol% styrene.
Or more, preferably 60 mol% or more. (A)
Examples of the method of bonding the copolymer (AB) in which (b) and (b) are bonded in a graft form and / or a block form include the following. Graft copolymer in which the branch polymer of (b) is grafted on the backbone polymer of (a) Graft copolymer in which the branch polymer of (a) is grafted on the backbone polymer of (b) The block copolymer of (a) and (b) Preferred among these are:

Compounds (1) to (19) are illustrated as specific examples of the charge control agent used in the present invention. Compound (1) Polymer represented by Formula 3

[0037]

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Compound (2) Polymer represented by Formula 4

[0039]

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Compound (3) Polymer represented by Formula 5

[0041]

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Compound (4) Polymer represented by Formula 6

[0043]

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Compound (5) Polymer represented by formula 7

[0045]

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Compound (6) Polymer represented by Formula 8

[0047]

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Compound (7) Polymer represented by Chemical formula 9

[0049]

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Compound (8) Polymer represented by formula (10)

[0051]

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Compound (9) Polymer represented by Formula 11

[0053]

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Compound (10) Methyl tosylate quaternized dimethylaminoethyl methacrylate / styrene (15/85) copolymer Compound (11) Lauryl bromide quaternized vinyl pyridine / styrene (20/80) copolymer Compound (12) Copolymer obtained by grafting a polymer portion represented by Chemical Formula 12 to a styrene polymer portion

[0055]

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Compound (13) Copolymer of styrene / butyl acrylate (95/5) copolymer grafted with polymer of formula (13)

[0057]

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Compound (14) Copolymer of styrene / butyl acrylate (98/2) copolymer grafted with polymer of formula (14)

[0059]

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Compound (15) Copolymer obtained by grafting the styrene / butyl acrylate (90/10) copolymer portion with the polymer portion represented by Chemical Formula 15

[0061]

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Compound (16) Copolymer of styrene / butyl methacrylate (85/15) copolymer grafted with polymer of formula (16)

[0063]

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Compound (17) Copolymer of styrene / butyl methacrylate (80/20) copolymer grafted with polymer of formula 17

[0065]

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Compound (18) Copolymer obtained by grafting the styrene / butadiene copolymer portion with the polymer portion represented by Chemical Formula 18

[0067]

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Compound (19) Copolymer of methacryloyloxyethyltrimethylammonium tetrafluoroborate polymer grafted with styrene polymer

(A) and (AB) used in the present invention are produced by known methods such as those described in JP-A-3-15079, JP-A-5-165258 and JP-A-5-165259. it can.

As the charge control agent (β), another charge control agent (a nigrosine compound, a triphenylmethane compound, or a quaternary ammonium salt compound) is used together with (A) or (AB). Molecular compound) can also be used in combination. Furthermore, (A) and (AB) can be used together. By using these low-molecular charge control agents in combination, it is easy to adjust the required charge amount.

The coloring material (γ) used in the present invention includes:
Known pigments and dyes can be used. In particular,
Carbon Black, Iron Black, Sudan Black SM, Fast Yellow-G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgasin Red, Baranitoaniline Red, Toluidine Red, Carmine FB, Pigment Orange R, Lake Red 2G,
Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue, Priliant Green, Phthalocyanine Green,
Oil Yellow GG, Kayaset YG, Orazole Brown B, Oil Pink OP and the like.

The composition ratio of the toner of the present invention is usually 30 to 95% by weight of the toner binder (α), 0.1 to 20% by weight of the charge control agent (β), and the coloring material (γ) based on the weight of the toner. ) Is from 0 to 15% by weight, and if necessary, a magnetic powder (a powder of a ferromagnetic metal such as iron, cobalt or nickel or a compound such as magnetite, hematite, or ferrite) also functions as a coloring material and is 60% by weight or less. It may be contained. Further, as various additives, a lubricant (eg, polytetrafluoroethylene, low molecular weight polyolefin, fatty acid, or a metal salt or amide thereof) and the like can be contained. Further, hydrophobic colloidal silica fine powder or the like can be used to improve the fluidity of the toner. The amount of these additives is usually 10% by weight or less based on the weight of the toner.

The method for obtaining the toner of the present invention is not particularly limited, but can be obtained by the following method. Kneading / Pulverizing Method After dry-blending the components constituting the toner, they are melt-kneaded, then coarsely pulverized, and finally pulverized using a jet pulverizer or the like. After further classification, the toner is obtained as fine particles having a particle size of usually 5 to 20 microns. External Addition Method After dry-blending a charge control agent to particles having a particle size of 5 to 20 microns comprising a toner binder, a coloring material, and, if necessary, a lubricant and a magnetic powder, the mixture is strongly mixed by a mixer while heating as necessary. In addition, a toner is obtained.

The toner for developing an electrostatic image of the present invention may contain, if necessary, carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and ferrite whose surface is coated with a resin (acrylic resin, silicone resin, etc.). And used as a developer for an electric latent image. In addition, instead of the carrier particles, friction with a member such as a charging blade can be performed to form an electric latent image. The electrostatic image developing toner of the present invention is fixed on a support (paper, polyester film, or the like) by a copying machine, a printer, or the like to form a recording material. As a method for fixing to a support, a known hot roll fixing method, flash fixing method, or the like can be applied.

[0075]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. Hereinafter, "part" indicates "part by weight". Further, the exemplified compounds described in the examples are compounds (1) to (19) exemplified as specific examples of the charge control agent.

[0076]

【Example】

Example 1 100 parts of toner binder (TB1) (However, a mixture of the following polymer component and low-molecular component) Polymer component (15% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20/52 / 2
8) Copolymer Weight average molecular weight: 900,000, number average molecular weight: 300,000, T
g: 60 ° C. Low molecular weight component (85% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20/69/11) copolymer Weight average molecular weight: 4700, number average molecular weight: 2300,
Tg: 55 ° C. Charge control agent Exemplified compound (3) 2 parts Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Biscol 660P {manufactured by Sanyo Chemical Industry Co., Ltd.} After preliminary mixing using a Henschel mixer (FM10B, manufactured by Mitsui Miike Kakoki Co., Ltd.), the mixture was kneaded with a twin-screw kneader (PCM-30, Ikegai Co., Ltd.). Then, after crushing finely using a supersonic jet crusher LabJet (manufactured by Nippon Pneumatic Industries Co., Ltd.), airflow classifier MD
SI, classified by Nippon Pneumatic Industrial Co., Ltd.
A powder having a particle size of about 20 μm was obtained, and the toner (1) of the present invention was obtained.
I got Table 1 shows the evaluation results.

Example 2 100 parts of toner binder (TB2) (However, a mixture of the following high molecular components and low molecular components) High molecular component (55% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20 / 52/2
8) Copolymer Weight average molecular weight: 900,000, number average molecular weight: 300,000, T
g: 60 ° C. Low molecular weight component (45% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20/69/1)
1) Copolymer Weight average molecular weight: 4700, number average molecular weight: 2300,
Tg: 55 ° C. Charge control agent Exemplified compound (17) 4 parts Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Biscol 660P {manufactured by Sanyo Chemical Industry Co., Ltd.> The toner was converted into a toner in the same manner as in Example 1 to obtain a toner (2) of the present invention. Table 1 shows the evaluation results.

Reference Example 3 100 parts of toner binder (TB3) (However, a mixture of the following polymer component and low-molecular component) Polymer component (30% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20 / 52/28) Copolymer Weight average molecular weight: 900,000, number average molecular weight: 300,000, T
g: 60 ° C. Low molecular component (70% by weight): Isophthalic acid / bisphenol A propylene oxide 2 mol adduct (27/73) polycondensate Weight average molecular weight: 5400, number average molecular weight: 2600,
Tg: 57 ° C. Charge control agent Exemplified compound (16) 5 parts Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Biscol 660P {manufactured by Sanyo Chemical Industries, Ltd.} The toner was converted into a toner in the same manner as in Example 1 to obtain a toner (3) of the present invention. Table 1 shows the evaluation results.

REFERENCE EXAMPLE 4 100 parts of toner binder (TB4) (However, a mixture of the following high molecular components and low molecular components) High molecular component (20% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20 / 52/28) Copolymer Weight average molecular weight: 900,000, number average molecular weight: 300,000, T
g: 60 ° C. Low molecular component (80% by weight): Terephthalic acid / bisphenol A propylene oxide 2 mol adduct / dodecenyl succinic acid (23/70 /
7) Polycondensate Weight average molecular weight: 7300, number average molecular weight: 3800,
Tg: 61 ° C. Charge control agent Exemplified compound (12) 5 parts Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Biscol 660P {manufactured by Sanyo Chemical Industries, Ltd.} The toner was converted into a toner in the same manner as in Example 1 to obtain a toner (4) of the present invention. Table 1 shows the evaluation results. Also,
The resin pieces kneaded in the same manner as in Example 1 without adding carbon black and low molecular weight polypropylene were pale yellow and transparent.

Example 5 100 parts of toner binder (TB5) (However, a mixture of the following high molecular components and low molecular components 1 and 2) High molecular component (15% by weight): acrylonitrile / styrene / acrylic acid-2 Ethylhexyl (20/52/2
8) Copolymer Weight average molecular weight: 900,000, number average molecular weight: 300,000, T
g: 60 ° C. Low molecular component 1 (80% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20/69/1)
1) Copolymer Weight average molecular weight: 4700, number average molecular weight: 2300,
Tg: 55 ° C. Low molecular component 2 (5% by weight): 4,4′-diphenylmethane diisocyanate / bisphenol A ethylene oxide 2 mol adduct (29/71) polyadduct Weight average molecular weight: 2700, number average molecular weight: 1300 ,
Tg: 49 ° C. Charge control agent Exemplified compound (16) 4 parts Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Biscol 660P {manufactured by Sanyo Chemical Industries, Ltd.} The toner was converted into a toner in the same manner as in Example 1 to obtain a toner (5) of the present invention. Table 1 shows the evaluation results.

Example 6 100 parts of toner binder (TB6) (However, a mixture of the following high molecular components and low molecular components 1 and 2) High molecular component (15% by weight): acrylonitrile / styrene / acrylic acid-2 Ethylhexyl (20/52/2
8) Copolymer Weight average molecular weight: 900,000, number average molecular weight: 300,000, T
g: 60 ° C. Low molecular weight component 1 (65% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20/69/1)
1) Copolymer Weight average molecular weight: 4700, number average molecular weight: 2300,
Tg: 55 ° C. Low molecular component 2 (20% by weight): 2 mol of propylene oxide adduct of isophthalic acid / bisphenol A (27 /
73) Polycondensate Weight average molecular weight: 5400, number average molecular weight: 2600,
Tg: 57 ° C. Charge control agent Exemplified compound (12) 4 parts Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Biscol 660P {manufactured by Sanyo Chemical Industries, Ltd.} The toner was converted into a toner in the same manner as in Example 1 to obtain a toner (6) of the present invention. Table 1 shows the evaluation results.

Example 7 100 parts of toner binder (TB7) (However, a mixture of the following high molecular components and low molecular components 1 and 2) High molecular component (15% by weight): acrylonitrile / styrene / acrylic acid-2 Ethylhexyl (20/52/2
8) Copolymer Weight average molecular weight: 900,000, number average molecular weight: 300,000, T
g: 60 ° C. Low molecular component 1 (20% by weight): acrylonitrile / styrene / 2-ethylhexyl acrylate (20/69/1)
1) Copolymer Weight average molecular weight: 4700, number average molecular weight: 2300,
Tg: 55 ° C. Low molecular component 2 (65% by weight): terephthalic acid / bisphenol A ethylene oxide 2 mol adduct (28/7
2) Polycondensate Weight average molecular weight: 4000, number average molecular weight: 2200,
Tg: 49 ° C. Charge control agent Exemplified compound (12) 3 parts Nigrosine dye 1 part Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Biscol 660P {manufactured by Sanyo Chemical Industries, Ltd.} The ingredients of the formulation were converted to toners in the same manner as in Example 1 to obtain the toner (7) of the present invention. Table 1 shows the evaluation results.

Comparative Example 1 Toner binder (CTB1) (However, a mixture of the following high molecular components and low molecular components) High molecular component (15% by weight): styrene / acrylic acid-2
Ethylhexyl (81.5 / 18.5) copolymer Weight average molecular weight: 7,000,000, number average molecular weight: 260,000, T
g: 62 ° C. Low molecular weight component (85% by weight): styrene / acrylic acid-2
Ethylhexyl (96/4) copolymer Weight average molecular weight: 4600, number average molecular weight: 2260,
Tg: 56 ° C. Charge control agent Exemplified compound (12) 4 parts Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Biscol 660P {manufactured by Sanyo Chemical Industries, Ltd.} A toner was prepared in the same manner as in Example 1 to obtain a comparative toner (C1). Table 1 shows the evaluation results.

Comparative Example 2 Toner binder (CTB2) Terephthalic acid / dodecenyl succinic acid / bisphenol A
Propylene oxide 2 mol adduct / phenol novolak propylene oxide 2 mol adduct (20/5
9/14/7) Polycondensate Peak molecular weight: 5100, gel content 35%, Tg: 59
° C Charge control agent Exemplified compound (12) 4 parts Carbon black 5 parts # 40, manufactured by Mitsubishi Chemical Corporation Low molecular weight polypropylene 4 parts Viscol 660P {manufactured by Sanyo Chemical Industry Co., Ltd.} In the same manner as in the above, a toner was obtained to obtain a comparative toner (C2). Table 1 shows the evaluation results.

Comparative Example 3 A toner was prepared in the same manner as in Example 4 except that the charge control agent was changed to 2 parts of benzyltributylammonium hydroxynaphthalenesulfonate to obtain a comparative toner (C3). Table 1 shows the evaluation results. The resin piece kneaded in the same manner as in Example 4 without adding carbon black and low molecular weight polypropylene was pale yellow but cloudy.

Comparative Example 4 A toner was prepared in the same manner as in Example 4 except that the charge control agent was changed to 2 parts of nigrosine dye to obtain a comparative toner (C4). Table 1 shows the evaluation results. The resin piece kneaded in the same manner as in Example 4 without adding carbon black and low molecular weight polypropylene was black purple.

[0087]

[Table 1] Evaluation results------------------------------------------------------------------tonton No. Charge amount (° C) (° C) (μC / g) Rise Distribution −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1) 140> 220 B +10 A B (2) 142> 220 A +13 A A (3) 133> 220 A +10 A A (4) 132> 220 A +11 A A (5) 135> 220 B +12 A A (6) 132> 220 B +13 A A (7) 130> 220 A +14 A A −−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−− (C1) 140 180 C +12 A A (C2) 142 210 A +5 A B (C3) 132> 220 A +7 AC (C4) 132> 220 A +15 C C ------------------------------ MTF: Minimum fixing temperature ** HOT: Hot Offset occurrence temperature

(Evaluation Method) Preparation of Developer One part of the toner and 24 parts of a silicone resin-coated ferrite carrier were mixed to prepare a developer. Fixing test (lower fixing temperature and hot offset resistance) A commercially available copying machine (SF84, manufactured by Sharp Corp.)
00A) using a modified machine from which the fixing section has been removed,
An unfixed image was obtained. The unfixed image was subjected to a fixing test at a speed of 35 sheets / minute of A4 paper using a fixing tester in which a fixing unit of a commercial copying machine (SF8400A manufactured by Sharp Corporation) was modified. A black solid portion having an image density of 1.2 was rubbed with a Gakushin-type fastness tester (friction portion = paper) by five reciprocations, and the image density of the solid portion after rubbing remained at 70% or more. The minimum heat-fixing temperature (MFT) was the heat roll temperature at the time when the toner was obtained. The hot roll occurrence temperature (HOT) was defined as the heat roll temperature at the time of hot offset of the toner. Durability 100% of the above developer with a tumbler shaker mixer
The mixture was stirred at rpm × 12 hours, and the change in particle size distribution of the toner before and after stirring was measured using a Coulter counter. Measurement of Saturated Charge Amount (Charge Amount) H. And humidify for 8 hours or more, then use a tumbler shaker mixer at 25 rpm.
× 1, 3, 7, 20, 60 and 120 minutes of friction stirring, and the charge amount was measured at each time. The charge amount during the friction time when the increase in the charge amount was stopped was defined as the saturation charge amount. Measuring device: Blow-off charge amount measuring device @ Toshiba Chemical
Evaluation standard for rising (rising) of charging The following criteria were used for evaluation based on the results of measuring the amount of charging. A: Friction time to reach a charge amount of 80% of the saturated charge amount is less than 7 minutes B: Friction time to reach a charge amount of 80% of the saturated charge amount is 7 to 20 minutes C: Saturation charge amount The friction time to reach 80% of the charge amount exceeds 20 minutes. Measurement of charge amount distribution H. After adjusting the humidity for 8 hours or more, use a tumbler shaker mixer at 50 rpm.
The mixture was friction-stirred for 20 minutes, and the charge amount distribution was measured. Apparatus: Particle charge amount distribution measuring apparatus (EST-1, manufactured by Hosokawa Micron Corporation)

The following can be seen from the results in Table 1. The positively chargeable toner of the present invention, while maintaining sufficient hot offset resistance, is excellent in low-temperature fixability, durability, and has an appropriate charge amount, and has a fast charge rise, The quantity distribution is also sharp. On the other hand, the comparative toner (C1) using a styrene acrylic resin as a toner binder has excellent chargeability, but has poor durability. In addition, the fixing temperature range (MFT
And the difference between HOT). The comparative toner (C2) using a polyester resin as a toner binder has excellent durability,
There is a problem that the charge amount is low. Comparative toner using low molecular compound charge control agent (C
3) and (C4) have a problem that the charge amount distribution is wide. Similarly, the comparative toners (C3) and (C4) have poor transparency or coloring and are expected to have an adverse effect on color tone when used in color toners.

[0090]

The positively chargeable toner of the present invention has the following effects. 1. It has an appropriate charge amount and is excellent in both low-temperature fixability and durability. 2. Excellent charging rise, and reaches a certain amount of charge by short-time friction. 3. The dispersibility of the charge control agent is high and the charge amount distribution is sharp. 4. The coloring of the charge control agent is weak, the transparency of the toner is high, and the color tone of a color toner is excellent.

Continuation of front page (56) References JP-A-5-34973 (JP, A) JP-A-3-101749 (JP, A) JP-A-7-56394 (JP, A) JP-A-3-158866 (JP) JP-A-4-202305 (JP, A) JP-A-62-264066 (JP, A) JP-A-5-165258 (JP, A) JP-A-3-15079 (JP, A) JP-A-2-87165 (JP, A) JP-A-3-217854 (JP, A) JP-A-3-217855 (JP, A) JP-A-4-101164 (JP, A) A) JP-A-6-27731 (JP, A) JP-A-58-1444836 (JP, A) JP-A-63-113559 (JP, A) JP-A-63-231360 (JP, A) -264960 (JP, A) JP-A-3-182768 (JP, A) JP-B-63-32382 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08

Claims (7)

(57) [Claims] 1. An electrostatic image developing toner containing a toner binder (α), a charge controlling agent (β) and a coloring material (γ), wherein the toner binder (α) has a weight average molecular weight of 200,000 to 3,000,000. Nitrile group-containing resin (1) containing (meth) acrylonitrile as a constituent unit in an amount of 5 to 40% by weight, and a weight average molecular weight of 1000
100,000 to 100,000 (meth) acrylonitrile 5 to 40% by weight
It contains a resin (2) containing a nitrile group contained as a constituent unit, and further contains a polymer (A) composed of a monomer unit having a quaternary ammonium group as a charge control agent (β). Positively chargeable toner. 2. The positively chargeable toner according to claim 1, wherein the polymer (A) is a polymer represented by the following general formula (I). General formula (I): Wherein R 1 is hydrogen or a C 1 -C 21 hydrocarbon group;
2 and R3 are each independently hydrogen or a C1 to C8 hydrocarbon group, or R2 and R3 may be mutually connected to form an aromatic ring. R4 represents a C1 to C12 alkylene group which may contain an ether bond in the group, X- represents an anion, and n represents an integer of 2 to 100. ) 3. The charge control agent (β) according to claim 1 or 2,
The polymer portion (a) having the same constitution as the polymer (A) described in (a).
The styrenic polymer portion (b) is grafted and / or
2. The positively chargeable toner according to claim 1, which is a copolymer (AB) bonded in a block shape. 4. A nigrosine compound together with (A) and / or (AB) as a charge control agent (β).
The positively chargeable toner according to any one of claims 1 to 3, wherein a low molecular weight compound selected from the group consisting of a triphenylmethane compound and a quaternary ammonium salt compound is used in combination. 5. A copolymer comprising (1) 5 to 40% by weight of (meth) acrylonitrile, 40 to 80% by weight of styrene, and 3 to 20% by weight of another vinyl monomer. The positively chargeable toner according to claim 1, wherein: 6. The positively chargeable toner according to claim 1, wherein (1) is contained in the toner binder (α) in an amount of 3 to 50% by weight. 7. A copolymer comprising (2) 5 to 40% by weight of (meth) acrylonitrile, 40 to 80% by weight of styrene and 3 to 20% by weight of another vinyl monomer. The positively chargeable toner according to any one of claims 1 to 6, wherein