JPH08305081A - Electrophotographic toner binder - Google Patents

Abstract

PURPOSE: To obtain a toner binder giving a toner having satisfactory heat resistance, preservability and electrical characteristics, causing hot offsetting at higher temp. and excellent in low-temp. fixability by introducing nitrile groups into a resin of a toner binder consisting of two kinds of resins each having a specified modulus of storage elasticity at a specified temp. CONSTITUTION: This toner binder consists of resins (A), (B). The modulus of storage elasticity of the resin A at 170 deg.C is >=500,000dyn/cm<2> , preferably >=1,000,000dyn/cm<2> , especially preferably >=2,000,000dyn/cm<2> . In the case of <500,000dyn/cm<2> , hot offsetting is caused at lower temp. The modulus of storage elasticity of the resin B at 170 deg.C is <=100,000dyn/cm<2> , preferably <=10,000dyn/cm<2> , especially preferably <=1,000dyn/cm<2> . In the case of >100,000dyn/cm<2> , the min. fixing temp. is increased. The resin A is a resin having nitrile groups.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a toner binder for electrophotography.

[0002]

2. Description of the Related Art In an electrophotographic process using powder dry toner, a contact heating type fixing device (a method of using a heat roll, a method of using a heat roller and a paper or the like) is used to fix the toner transferred onto the paper or the like. Method using a film or belt (for example, JP-A-4-70688 and JP-A-4-70688).
No. 12558) is widely adopted. In this method, it is desirable that the minimum fixing temperature (hereinafter abbreviated as MFT) is low (low temperature fixing property), and the temperature at which hot offset occurs on the heat roll surface, film or belt (hereinafter abbreviated as HOT) is high. Is preferable (hot offset resistance). In addition, heat is generated from a fixing device or the like in the machine of the electrophotographic process, so that heat-resistant storage stability must be satisfied so that the toner does not agglomerate due to heat and the fluidity is deteriorated.

Conventionally, polystyrene resins, styrene-acrylic copolymers, polyester resins, epoxy resins and the like have been generally used as the binder component of this dry toner. Among them, polystyrene is preferable from the viewpoints of performance such as pulverizability and chargeability, and cost. Along with the increase in processing speed of copying machines, polyester resins having good fixing properties are widely used. In order to satisfy the low-temperature fixability, hot offset resistance, and heat resistant storage stability, there have been proposed many methods of improving the resin by widening the molecular weight distribution. As a method for broadening the molecular weight distribution, for vinyl resins, a method using a vinyl crosslinking agent (Japanese Patent Laid-Open No. 215558/1986) or a molecular weight distribution having two peaks in a high molecular weight portion and a low molecular weight portion is used. Binder (Japanese public Sho 63-3
No. 2180, Japanese Patent Publication No. 63-32382) are proposed. As the polyester resin, a polyester resin using an oxyalkylene ether of a novolac type phenol resin (Japanese Patent Laid-Open No. 5-2747).
No. 8) or a method using a heating reaction product of a vinyl copolymer resin having a hydroxyl group and an amorphous polyester resin (for example, JP-A-2-277074).

[0004]

However, as described above, in the case of a binder having a crosslinked structure, or a binder simply composed of a high molecular weight substance and a low molecular weight substance, in order to maintain the hot offset resistance, a crosslinking component or a high molecular weight component is used. Many molecular weight components will be used. Therefore, the resin becomes hard and the pulverizability at the time of toner production is lowered. Further, the melt viscosity of the resin increases, and the low temperature fixing property of the toner becomes insufficient. As described above, in the conventional technology, due to the recent increase in the speed of copying machines and facsimiles, there is a trend toward lower temperature fixing ability, and due to the downsizing of printers, there is a trend toward higher heat-resistant storage stability and hot offset resistance. Therefore, it is hard to say that the trend of improving pulverizability at the time of toner production is sufficiently dealt with.
The present invention is to solve the above problems, good pulverizability at the time of toner production, no problem in heat resistant storage stability and electrical characteristics when made into a toner, high hot offset generation temperature, and low temperature. The purpose is to obtain a toner binder having excellent fixability.

[0005]

The present inventors have found that the pulverizability at the time of toner production is good, there is no problem in heat resistant storage stability and electrical characteristics when made into a toner, the hot offset generation temperature is high, and The present invention has been achieved as a result of extensive studies aimed at obtaining a toner binder having excellent low-temperature fixability.
That is, the present invention has a storage elastic modulus at 170 ° C. of 500,000 d.
A toner binder for electrophotography comprising a resin (A) having a yn / cm ² or more and a resin (B) having a storage elastic modulus at 170 ° C. of 100,000 dyn / cm ² or less, wherein (A) contains a nitrile group. It is a resin that does.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. In the toner binder of the present invention, the storage elastic modulus of the resin (A) at 170 ° C. is 500,000 dyn / cm ² or more. It is preferably 1 million dyn / cm ² or more, and more preferably 2 million dyn / cm ² or more. 500,000 dy
If it is smaller than n / cm ² , HOT becomes low. Resin (B)
The storage elastic modulus at 170 ° C. is 100,000 dyn / cm ² or less. It is preferably 10,000 dyn / cm ² or less,
More preferably, it is 1000 dyn / cm ² or less. 1
If it is larger than 0,000 dyn / cm ² , MFT will be high. In the toner binder of the present invention, the resin (A) is a resin containing a nitrile group. Usually the toner binder is
Components with high storage modulus (usually high molecular weight component or cross-linking component) and components with low storage modulus (usually low molecular weight component)
In order to increase the HOT, it is necessary to increase the storage elastic modulus of the binder. Therefore, usually, a method of using a large proportion of a component having a large storage elastic modulus is adopted. However, if the amount of the component having a large storage elastic modulus is too large, the MFT becomes high, and the resin becomes hard, so that the pulverizability at the time of toner production also deteriorates. However, as in the present invention, by introducing a nitrile group into the resin,
The resin (A) has a very large storage elastic modulus at a high temperature as compared with a resin having no nitrile group, which is smaller than the amount of the component having a large storage elastic modulus used in a usual toner binder in an amount smaller than that of the binder. The storage elastic modulus can be maintained. That is, the HOT when used as toner is high, and the MF
A binder having a low T and good pulverizability during toner production can be obtained.

The resin containing a nitrile group is not particularly limited, but the methyl group of acrylonitrile, methacrylonitrile or methacrylonitrile is substituted with a lower alkyl group such as an ethyl group, a propyl group, an isopropyl group, a butyl group or an isobutyl group. Vinyl monomer, α-
Copolymers of vinyl monomers containing a nitrile group such as cyano-3-hydroxycinnamic acid and α-cyano-4-hydroxycinnamic acid with other vinyl monomers, and α-cyano-3-hydroxycinnamic acid , Α-cyano-4-hydroxycinnamic acid and the like, and a polyester resin in which a nitrile group is introduced by reacting a component containing a nitrile group with a hydroxyl group and a carboxyl group during polycondensation of the polyester resin. Among these, preferred are copolymers of (meth) acrylonitrile and other vinyl monomers. Other vinyl-based monomers used in the copolymer (A) of (meth) acrylonitrile and other vinyl-based monomers are not particularly limited, but include styrene, α-methylstyrene, p-methoxystyrene, p -Styrene-based monomers such as hydroxystyrene and p-acetoxystyrene; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate , An alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms such as stearyl (meth) acrylate; a hydroxyl group-containing (meth) acrylate such as hydroxyethyl (meth) acrylate; dimethylaminoethyl (meth) acrylate; Contains amino groups such as diethylaminoethyl (meth) acrylate ) Acrylate; vinyl esters such as vinyl acetate; vinyl ethers such as vinyl ethyl ether; aliphatic hydrocarbon vinyls such as α-olefin and isoprene; (meth) acrylic acid, maleic anhydride, itaconic anhydride, maleic anhydride Unsaturated carboxylic acids such as monoesters thereof or their anhydrides can be mentioned. Of these, styrene-based monomers, alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl group, unsaturated carboxylic acids are preferable, and styrene, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic Butyl acid, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and (meth) acrylic acid are more preferable. The proportion of (meth) acrylonitrile in (A) is usually 3 to 60% by weight (5% as a nitrile group).
6-1132 mmol / 100 g polymer). Preferably, 5 to 40% by weight (94 to 75 as a nitrile group)
5 mmol / 100 g polymer). More preferably, it is 10 to 20% by weight (188 to 37 as a nitrile group.
7 mmol / 100 g polymer).

As the polymerization method (A), any method such as solution polymerization, bulk polymerization and suspension polymerization can be selected. The polymerization initiator is not particularly limited, but for example, azo-based initiators such as azobisisobutyronitrile and azobisisovaleronitrile; benzoyl peroxide, di-t
-Butyl peroxide, lauroyl peroxide,
Peroxide initiators such as dicumyl peroxide; 2,
2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, di-t-
Butyl peroxyhexahydroterephthalate etc. 1
Polyfunctional polymerization initiator having two or more peroxide groups in the molecule; 1 in one molecule such as diallyl peroxydicarbonate and t-butyl peroxyallyl carbonate
Examples thereof include polyfunctional polymerization initiators having one or more peroxide groups and one or more polymerizable unsaturated groups. Among these, preferred are polyfunctional polymerization initiators having two or more peroxide groups in one molecule.

The solvent for obtaining (A) by solution polymerization is not particularly limited, but toluene, xylene,
Aromatic solvents such as ethylbenzene, ester solvents such as ethyl acetate and butyl acetate, dimethylformamide,
Examples thereof include dimethyl sulfoxide and methyl ethyl ketone. Preferred are dimethylformamide, xylene, and toluene.

When (A) is obtained by suspension polymerization,
Polymerization can be carried out in water using an inorganic salt dispersant such as calcium carbonate or calcium phosphate, or an organic dispersant such as polyvinyl alcohol or methylated cellulose.
The polymerization temperature of (A) is usually 50 to 160 ° C., preferably 6
It is 0 to 140 ° C. The atmosphere during the (co) polymerization is preferably carried out in the presence of an inert gas such as nitrogen.

In order to make the molecular weight higher during the polymerization of (A), a polyfunctional monomer having at least two polymerizable double bonds is added in an amount such that gelation does not occur (usually 0.1).
% Or less) may be added. Examples of polyfunctional monomers include di- or polyvinyl compounds (for example, divinylbenzene, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, divinyltoluene) and the like. Of these, divinylbenzene, 1,6-hexanediol diacrylate, divinyltoluene) and the like are preferable.

The weight average molecular weight of (A) is usually 100,000 to 1
It is 10,000,000, preferably 150,000 to 5,000,000, and more preferably 200,000 to 3,000,000. When the weight average molecular weight of (A) is 100,000 or less, the storage elastic modulus at 170 ° C. of (A) becomes small, and the HOT when used as a toner tends to be low. If it is 10 million or more, the pulverizability during toner production may be deteriorated, and the MFT when used as a toner tends to be high. The number average molecular weight of (A) is usually 30,000 to 3
, 000,000, preferably 50,000 to 1,500,000, more preferably 7
10,000 to 1 million. The glass transition point (Tg) of (A) is usually 30 to 100 ° C, preferably 35 to 90 ° C, and more preferably 40 to 85 ° C. If the Tg is less than 30 ° C, the heat-resistant storage stability of the toner may deteriorate.
If the Tg exceeds 100 ° C., the MFT of the toner may increase.

In the toner binder of the present invention,
The content of (A) is usually 3 to 50% by weight, preferably 5
-40% by weight, more preferably 7-30% by weight. When the content of (A) is less than 3% by weight, the storage elastic modulus of the toner binder at high temperature becomes small, and the HOT when used as a toner may become low. If it exceeds 50% by weight, the pulverizability during toner production may be deteriorated, and the MFT of the toner may be increased.

In the toner binder of the present invention,
(B) is not particularly limited, for example, vinyl resin, polyester (B2), polyurethane (B3), epoxy resin (B4), polyamide (B5), coumarone resin, ketone resin, xylene resin, terpene resin, phenol resin, etc. Is mentioned. Among these, vinyl resin, polyester (B2), polyurethane (B
3), epoxy resin (B4) and polyamide (B5).

Specific examples of the vinyl-based resin include a vinyl-based resin obtained by (co) polymerizing at least one selected from the vinyl-based monomers described above, (meth) acrylonitrile and the vinyl-based resin described above. Copolymer of polymer (B1)
And the like. Among these, a copolymer (B) of (meth) acrylonitrile and the vinyl monomer described above (B
1) is preferred. Among the vinyl-based monomers described above, styrene-based monomers, alkyl (meth) acrylates having an alkyl group having 1 to 18 carbon atoms, unsaturated carboxylic acids are preferable, and styrene, methyl (meth) acrylate, (meth)
Ethyl acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and (meth) acrylic acid are more preferable.
The proportion of (meth) acrylonitrile in (B1) is usually 3 to 60% by weight (56 to 1132 mmol of nitrile group / 100 g polymer). Preferably, 5-4
0% by weight (94 to 755 mmol / 1 as nitrile group / 1
00g polymer). More preferably, 10 to 20% by weight (188 to 377 mmol / 10 as nitrile group / 10
0 g polymer).

As the polymerization method of (B1), solution polymerization,
Any method such as bulk polymerization and suspension polymerization can be selected, but solution polymerization is preferable from the viewpoint of lowering the molecular weight. The polymerization initiator is not particularly limited, and examples thereof include the above-mentioned polymerization initiators. Among these, preferred are azo initiators (azobisisobutyronitrile, azobisisovaleronitrile, etc.) and peroxide initiators (benzoyl peroxide, di-t-butyl peroxide, lauroyl peroxide). , Dicumyl peroxide, etc.) and the like. The solvent for obtaining (B1) by solution polymerization is not particularly limited, and examples thereof include the solvents described above. Of these, dimethylformamide, xylene and toluene are preferable. The polymerization temperature of (B1) is usually 80 to 210 ° C., preferably 140 to 205.
° C. The atmosphere during the (co) polymerization is preferably carried out in the presence of an inert gas such as nitrogen.

The weight average molecular weight of (B1) is usually 1000.
˜50,000, preferably 2,000 to 30,000, more preferably 3
000 to 20,000. If the weight average molecular weight is less than 1000, the Tg of (B1) becomes low, and the heat-resistant storage stability of the toner may deteriorate. When it exceeds 50,000,
The pulverizability at the time of toner production may be deteriorated, and the MFT of the toner may be increased. (B
The Tg of 1) is usually 20 to 85 ° C., preferably 35 to 80.
C., more preferably 45 to 75.degree. Tg is 20
If the temperature is less than ℃, the heat-resistant storage stability of the toner may be deteriorated.
FT can be high. To restate the difference between the polymerization methods of (A) and (B1), it is preferable to carry out (B1) at a temperature relatively higher than the polymerization temperature of (A). Further, (A) preferably uses a polyfunctional initiator, while (B1)
Is preferably a monofunctional initiator.

The polyester (B2) used in the present invention is
For example, it can be obtained by polycondensing a dihydric alcohol and a dibasic acid (dibasic acid, anhydride, lower esterified product) and, if necessary, a tricarboxylic or higher polycarboxylic acid and / or a trihydric or higher alcohol. A monoalcohol or a monocarboxylic acid may be used in combination for the purpose of sealing the terminal carboxylic acid or the terminal hydroxyl group, or for the purpose of adjusting the molecular weight or controlling the reaction. As the divalent alcohol, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4
-Butanediol, neopentyl glycol, 1,6-
Aliphatic glycols such as hexanediol and their alkylene oxide adducts; hydroquinone,
Catechol, resorcin, pyrogallol, bisphenols (bisphenol A, bisphenol AD, bisphenol F, bisphenol sulfone, etc.) and hydrogenated bisphenols and phenolic glycols obtained by adding alkylene oxide to these; and mixtures of two or more of these Can be mentioned. Examples of the alkylene oxide include ethylene oxide and propylene oxide. When a mixture of these is added, block addition or random addition may be performed. Among these, preferred are ethylene glycol, neopentyl glycol and bisphenols (particularly bisphenol A) to which 2 to 3 mol of alkylene oxide is added, and a mixture thereof, and particularly preferred are neopentyl glycol and bisphenol. It is a compound obtained by adding 2 to 3 mol of alkylene oxide of A, and a mixture of two or more kinds thereof.

As the dibasic acid, 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, cyclohexanedicarboxylic acid, nadic acid, methyl nadic acid, octyl succinic acid, dodecenyl succinic acid, etc., and anhydrides of these acids , Lower alkyl (methyl, ethyl) esters and the like. In addition, polymerized fatty acids such as dimers and trimers of linoleic acid can also be used. The dibasic acid can be used alone or as a mixture of two or more kinds. Among these, alkyl or alkenyl (having 4 to 18 carbon atoms) succinic acids represented by succinic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, octylsuccinic acid and dodecenylsuccinic acid are preferable.

Specific examples of tricarboxylic or higher polycarboxylic acids include (1) aliphatic polycarboxylic acids having 7 to 20 carbon atoms (1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid). Etc.); (2) C9-20 alicyclic polycarboxylic acid (1,2,4-cyclohexanetricarboxylic acid etc.); (3) C9-20 aromatic polycarboxylic acid (1,2, 4-benzenetricarboxylic acid,
1,2,5-benzenetricarboxylic acid, pyromellitic acid, etc.); and their anhydrides and lower alkyl (methyl, butyl, etc.) esters. Among these, (3) and its anhydrides and lower alkyl esters are preferable. Specific examples of trihydric or higher alcohols include:
(1) Aliphatic polyhydric alcohol having 3 to 20 carbon atoms (sorbitol, 1,4-sorbitan, pentaerythritol,
(Trimethylolethane, trimethylolpropane, glycerol, etc.); (2) Aromatic polyhydric alcohols having 6 to 20 carbon atoms (1,3,5-trihydroxylmethylbenzene, etc.); and their alkylene oxide adducts; (3 ) Novolak type phenolic resin oxyalkylene ether; (4) 2 in the molecule of isocyanuric acid, etc.
Examples thereof include oxyalkylene ether of a heterocyclic compound having one or more active hydrogens. Among these,
The compounds of (1), (3) and (4) are preferred,
(3) and (4) are more preferable. Monoalcohol,
Specific examples of the monocarboxylic acid include benzoic acid, paraoxybenzoic acid, toluenecarboxylic acid, salicylic acid, acetic acid,
Monocarboxylic acids such as propionic acid and stearic acid; monoalcohols such as benzyl alcohol, toluene-4-methanol and cyclohexanemethanol. The ratio of carboxylic acids and alcohols constituting the polyester resin of the present invention is such that alcoholic hydroxyl group equivalent / carboxyl group equivalent is usually 0.5 to 2.0,
Preferably 0.6-1.6, more preferably 0.7-
The ratio may be 1.4. In addition, when a carboxylic acid having a valence of 3 or more and / or an alcohol having a valence of 3 or more is used if necessary, the amount is usually 35% by weight or less, preferably 25% by weight or less. If the content of trivalent or higher carboxylic acids and / or trivalent or higher alcohols exceeds 35% by weight, the low temperature fixability of the toner is insufficient.

In the polycondensation reaction, a catalyst (for example, dibutyltin oxide, stannous oxide and tetrabutyl titanate) can be used if necessary, and usually 150 ° C. to 30 ° C.
It can be carried out at any temperature of 0 ° C. Further, this reaction can be carried out under normal pressure or reduced pressure, and in the presence or absence of an inert gas or solvent.

(B2) is usually 0.2 to 200, preferably 0.5 to 150 mg KOH / g and an acid value of usually 0.2.
~ 200, preferably 0.5-150 mg KOH / g
It has a hydroxyl value of. The weight average molecular weight of (B2) is usually 1000 to 100,000, preferably 1500 to 50,000, and more preferably 2000 to 30,000. The Tg of (B2) is usually 20 to 85 ° C, preferably 35 to 80 ° C, more preferably 45 to 75 ° C. If the Tg is less than 20 ° C, the heat-resistant storage stability of the toner may deteriorate, and if the Tg exceeds 85 ° C, the MFT of the toner may increase.

Polyurethane (B3) used in the present invention
Are obtained from polyisocyanates and polyols. To seal the terminal isocyanate and terminal OH,
A monoalcohol and a monoisocyanate can be used together. Specific examples of the polyisocyanate include (1)
Aromatic polyisocyanates {Tolylene diisocyanate (TDI), dimethyldiphenylmethane diisocyanate (MDI), modified MDI, naphthylene diisocyanate, xylylene diisocyanate, etc .; (2) Multimers of aromatic polyisocyanates (TDI, dimer such as MDI Body, trimer, etc.); (3) NCO-terminated urethane prepolymer {low-molecular-weight polyol (such as trimethylolpropane) and excess aromatic isocyanate (TDI)};
(4) Aliphatic polyisocyanates {tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate, etc.); (5) Aliphatic polyisocyanate multimers (IPDI trimers, etc.) are mentioned. Of these, TDI, MDI, and IPDI
Is preferred. Specific examples of the polyol include 2 described above.
Examples include polyhydric alcohols and trihydric or higher alcohols.
Other polyol components include (1) molecular weight 500
-3000 polyether diols (polytetramethylene glycol, polyethylene glycol, polypropylene glycol, etc.); (2) polyester diols having a molecular weight of 500-3000 {dicarboxylic acids (adipic acid, maleic acid, phthalic acid, etc.) and low-molecular diols (ethylene Glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.). Of these, EO and / or 2 to 4 mol of PO of bisphenol A are preferable.

The molar ratio of polyisocyanate to polyol is usually 0.5 to 1.5, preferably 0.6.
The ratio may be in the range of ~ 1.4, more preferably 0.7-1.3. The reaction temperature is usually 40 to 130 ° C. In the reaction, a catalyst used in the urethanization reaction (dibutyltin lurate, stannas octoate, etc.) can also be used.

The weight average molecular weight of (B3) is usually 1000.
100 to 100,000, preferably 1500 to 50,000, and more preferably 2000 to 30,000. Tg of (B3) is usually 2
It is 0 to 85 ° C, preferably 35 to 80 ° C, and more preferably 45 to 75 ° C. If the Tg is less than 20 ° C, the heat-resistant storage stability of the toner may deteriorate, and if the Tg exceeds 85 ° C, the MFT of the toner may increase.

Specific examples of the epoxy resin (B4) used in the present invention include bisphenol A type, bisphenol F type epoxy resin, novolac type epoxy resin, polyphenol type epoxy, polyglycidyl type epoxy resin and these epoxy resins and the above-mentioned epoxy resins. Reaction products with dicarboxylic acids and / or monocarboxylic acids are mentioned.
The weight average molecular weight of (B4) is usually 1,000 to 100,000, preferably 1,500 to 50,000, and more preferably 200.
It is 0 to 30,000. Tg of (B4) is usually 20 to 85 ° C,
Preferably 35 to 80 ° C., more preferably 45 to 75
° C. If the Tg is less than 20 ° C, the heat-resistant storage stability of the toner may deteriorate, and if the Tg exceeds 85 ° C, the MFT of the toner may increase.

The polyamide (B5) used in the present invention is
Although not particularly limited, it can be obtained from a carboxylic acid having a valence of 2 or more, an amine having a valence of 2 or more, and optionally a monocarboxylic acid and / or a monoamine. Specific examples of 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 divalent carboxylic acids described above. Specific examples of divalent or higher amines include (1)
Aliphatic polyamines (ethylenediamine, diethylenetriamine, triethylenetetramine, 1,2-diaminopropane, 1,3-diaminopropane, hexamethylenediamine, etc.); (2) Alicyclic polyamines (isoporonediamine, cyclohexylenediamine, etc.); (3) Aromatic polyamines (such as xylylenediamine and diaminodiphenylmethane). Of these, (1) is preferable. Specific examples of the monocarboxylic acid include the above-mentioned monocarboxylic acids, and other examples include mixed fatty acids (palm oil fatty acid, tall oil fatty acid, soybean oil fatty acid, beef tallow fatty acid, etc.). Specific examples of monoamines include n
-Propylamine, stearylamine, oleylamine, monoethanolamine and the like.

The ratio of carboxylic acids to polyamines is such that the carboxyl group equivalent / amino group equivalent is usually 0.5 to 1.
5, preferably 0.6 to 1.4, more preferably 0.7.
It may be any ratio as long as it is about 1.3. The reaction is usually
The temperature is 140 to 250 ° C., preferably 180 to 230 ° C. The reaction is preferably carried out in an inert gas such as nitrogen gas in order to prevent coloration. (B
The melting point of 5) is usually 20 to 150 ° C., preferably 40 to 1
The temperature is 40 ° C, and more preferably 60 to 120 ° C.
If the melting point is lower than 20 ° C, the heat-resistant storage stability of the toner may be poor, and if the melting point exceeds 150 ° C, the MFT of the toner may be high.

The type (B) may be one kind or may be composed of two or more kinds of resins. However, from the viewpoint of hot offset resistance, (A) is preferably substantially compatible with the continuous phase of the toner binder. Preferred among these (B) are at least one selected from the group consisting of (B1) and (B2) to (B5), (B1) and [(B2).
To at least one selected from the group of (B5)].
More preferably, the combination of (B1) and (B2) is used. (B
The ratio of 1) to (B2) is preferably such that (B2) is larger than (B1) when low temperature fixability is emphasized. When the hot offset resistance is emphasized, it is preferable that (B1) is larger than (B2). When two or more kinds of (B) are used, any of (B) may be dispersed in the continuous phase of the toner binder.

The method of blending (A) and (B) is not particularly limited, but a method of kneading both in a heat-melted state,
Examples include a method of devolatilizing after blending in the presence of a solvent and a method of polymerizing the other in the presence of one. Whether (A) is substantially compatible with the continuous phase of the toner binder can be generally judged by the appearance of the toner binder being transparent. When two or more kinds of (B) are used and (B) is dispersed, the toner binder may be cloudy. If it is difficult to make a judgment based on the appearance alone, scan the cross section of the toner binder with a scanning electron microscope (for example, Hitachi S
-800) or a transmission electron microscope (for example, H-7100 manufactured by Hitachi, Ltd.) at a magnification of about 1000 to 30000, and the dispersed state can be confirmed. Also,
The type of dispersed resin can be determined by comparing micrographs of samples with different ratios of the resin forming the toner binder.

The weight average molecular weight Mw of the toner binder of the present invention is usually 10,000 to 1,000,000, and the number average molecular weight Mn is
Is 1,000 to 50,000 and Mw / Mn is 10 to 1,000. Preferably, Mw is 50,000 to 800,000 and Mn is 2
It is 1,000 to 40,000, and Mw / Mn is 15 to 500. More preferably, Mw is 100,000 to 500,000 and Mn is 2
It is 500 to 30,000 and Mw / Mn is 20 to 100. A low molecular weight polyolefin (polyethylene, polypropylene, etc.) usually added to improve the hot offset resistance during the production of toner may be added to the toner binder of the present invention in advance. By adding it to the toner binder in advance, the low molecular weight polyolefin is more uniformly dispersed in the toner, and the heat resistant storage stability of the toner is improved. The addition amount of the low molecular weight polyolefin is usually 0.1 to 10% by weight based on the whole toner binder. Preferably 0.5 to 8% by weight, more preferably 1
~ 6% by weight. The method of addition is the method of adding when blending (A) and (B), and the method of polymerizing (B).
There is a method of adding a low molecular weight olefin and producing (B) in the presence thereof, and a method of further adding a low molecular weight polyolefin when blending (B) and (A) produced by the method. The number average molecular weight of the low molecular weight polyolefin is usually 1,000 to 10,000, and the weight average molecular weight is usually 3,000 to 50,000. However, since the appearance of the toner binder to which the low molecular weight polyolefin is added is not transparent, it is preferable to confirm the compatibility state of (A) and (B) by the method described above without adding the toner binder. Further, the measurement of the molecular weight of the toner binder is performed in a state where the low molecular weight polyolefin is not included.

An example of a method for producing an electrophotographic toner which is an application of the toner binder of the present invention will be described. The toner binder is usually 45 to 95% by weight based on the weight of the toner, and a known coloring agent (carbon black, iron black, (Benzidine yellow, quinacdrine, rhodamine B, phthalocyanine, etc.)
Is usually used in an amount of 5 to 10% by weight, and magnetic powder (a compound such as iron, cobalt, nickel, hematite, and ferrite) is usually used in an amount of 0 to 50% by weight, and various additives [charge adjusting agent (metal complex, nigrosine Etc.), lubricants such as polytetrafluoroethylene, low molecular weight polyolefins, fatty acids, or metal salts or amides thereof, etc.] can be added. The amount of these additives is usually 0 to 10% by weight based on the weight of the toner. The toner for electrophotography is dry-blended with the above components, melt-kneaded, coarsely pulverized, and finally finely pulverized by using a jet pulverizer to obtain fine particles having a particle size of 5 to 20 μm. The electrophotographic toner, if necessary, iron powder, glass beads,
It is used as a developer for an electric latent image by mixing with carrier particles such as nickel powder and ferrite. Further, hydrophobic colloidal silica fine powder can be used to improve the fluidity of the powder. The electrophotographic toner is a support (paper,
It is used after being fixed on a polyester film). The fixing method is as described above.

[0033]

The present invention will be further described with reference to the following examples, but the present invention is not limited thereto. Hereinafter, parts are parts by weight. The methods for measuring the properties of the resins obtained in the synthesis examples, examples and comparative examples are shown below.

Molecular Weight Measuring Device: Showa Denko KK SYSTEM-11 Conditions: Column Tosoh KK TSK ge
l GMHXL 2 pieces Measurement temperature: 40 ° C. Sample solution: 0.25 wt% tetrahydrofuran solution Injection amount: 100 μl Detector: Refractive index detector The molecular weight calibration curve was created using standard polystyrene.

Glass transition point (Tg) measurement device: Seiko Electronics Co., Ltd. DSC20, SS
C / 580 condition: ASTM (D3418-2) method

Storage elastic modulus measuring device: Rheometrics Inc.
USA) RDS-II Dynamics Spectrometer Test Fix Chair: 25 mmφ cone plate used Measurement frequency: 20 Hz (125.6 rad / sec) Distortion rate: 5% fixed

Production Example 1 1425 parts of water and 9 parts of polyvinyl alcohol were placed in a reaction vessel equipped with a thermometer, a stirrer, a condenser and a nitrogen inlet tube, and after sufficiently dissolving, 200 parts of acrylonitrile, 516 parts of styrene, acrylic acid -2 ethylhexyl 284
Part of the mixed monomer and 2.3 parts of di-t-butylperoxyhexahydroterephthalate were placed in a reaction vessel and subjected to suspension polymerization in a nitrogen stream at 85 ° C. for 10 hours and then at 98 ° C. for 3 hours. After cooling, the reaction product was filtered, washed with water, and dried at 55 ° C to obtain the resin (A-1) of the present invention. (A-1) has a weight average molecular weight of 900,000, a number average molecular weight of 300,000, a glass transition point of 60 ° C., and a storage elastic modulus at 170 ° C. of 3.2.
It was × 10 ⁶ dyn / cm ² .

Production Example 2 Resin (C-1) was obtained in the same manner as in Production Example 1 except that 815 parts of styrene and 185 parts of 2-ethylhexyl acrylate were used as mixed monomers. The weight average molecular weight of (C-1) is 70.
10,000, number average molecular weight 260,000, glass transition temperature 62 ℃, 1
Storage elastic modulus at 70 ° C. is 1.1 × 10 ⁶ dyn / cm ²
Met.

Production Example 3 2033 parts of water and 2.6 parts of polyvinyl alcohol were placed in a reaction vessel equipped with a thermometer, a stirrer, a condenser and a nitrogen inlet tube, and after sufficiently dissolving, 140 parts of acrylonitrile,
A mixed monomer of 677 parts of styrene and 183 parts of lauryl methacrylate, 2.8 parts of di-t-butylperoxyhexahydroterephthalate, and benzoyl peroxide of 0.2.
Six parts were placed in a reaction vessel, and suspension polymerization was carried out at 77 ° C. for 10 hours and then at 98 ° C. for 3 hours in a nitrogen stream. After cooling, the reaction product was filtered, washed with water, and dried at 55 ° C to obtain the resin (A-2) of the present invention. The weight average molecular weight of (A-2) is 10
30,000, number average molecular weight 380,000, glass transition point 70 ° C,
Storage elastic modulus at 170 ° C. is 4.0 × 10 ⁶ dyn / c
m ² . Production Example 4 400 parts of xylene and 140 acrylonitrile were placed in an autoclave reaction tank equipped with a thermometer, a stirrer, and a nitrogen introducing tube.
Parts, 677 parts of styrene, 183 lauryl methacrylate
Part, 1,6-hexanediol diacrylate 0.2
1 part, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 2 parts, and after nitrogen substitution,
Polymerization was carried out at 0 ° C. for 2 hours and further at 110 ° C. for 3 hours. Further at 150 ° C., di-t-butyl peroxide 1
And 30 parts of xylene were added dropwise over 30 minutes and the solvent was removed to obtain a resin (A-3) of the present invention. (A-3) has a weight average molecular weight of 550,000, a number average molecular weight of 70,000, a glass transition point of 64 ° C., and a storage elastic modulus at 170 ° C. of 1.0 ×.
It was 10 ⁶ dyn / cm ² . Production Example 5 646 parts of xylene was placed in an autoclave reaction tank equipped with a thermometer, a stirrer and a nitrogen introducing tube, and after substitution with nitrogen, 200 parts of acrylonitrile, 686 parts of styrene, and acrylic acid-2.
114 parts of ethylhexyl mixed monomer and xylene 1
A thermoplastic resin (B1-1) of the present invention was obtained by dropping an initiator solution of 18 parts and 52 parts of di-t-butyl peroxide at 170 ° C. for 3 hours and removing the solvent. (B
1-1) had a weight average molecular weight of 4,700, a number average molecular weight of 2,300, a glass transition point of 55 ° C., and a storage elastic modulus at 170 ° C. of 1,000 dyn / cm ² or less.

Production Example 6 The mixed monomer was 720 parts of styrene, 110 parts of lauryl methacrylate, 160 parts of acrylonitrile and 10 parts of acrylic acid, and the initiator was di-t-butyl peroxide 3
6 parts, and in the same manner as in Production Example 5, the thermoplastic resin (B1
-2) was obtained. The weight average molecular weight of (B1-2) is 630.
0, number average molecular weight 2800, glass transition point 58 ℃,
Acid value is 8mgKOH / g, storage elastic modulus at 170 ℃ is 1
It was 000 dyn / cm ² or less.

Production Example 7 Production Example 5 in which 730 parts of styrene, 110 parts of lauryl methacrylate and 160 parts of acrylonitrile were used as mixed monomers, and 36 parts of di-t-butyl peroxide was used as an initiator.
A thermoplastic resin (B1-3) was obtained in the same manner as. (B
The weight average molecular weight of 1-3) was 6,800, the number average molecular weight was 2,870, the glass transition point was 57 ° C., and the storage elastic modulus at 170 ° C. was 1,000 dyn / cm ² or less. Production Example 8 960 parts of styrene, acrylic acid-2-
Using 40 parts of ethylhexyl, a thermoplastic resin (B6) was obtained in the same manner as in Production Example 5. (B6) has a weight average molecular weight of 4,600, a number average molecular weight of 2,260, a glass transition point of 56 ° C., and a storage elastic modulus at 170 ° C. of 1000 dyn / c.
It was less than m ² . Production Example 9 367 parts of isophthalic acid and 1,000 parts of a 2 mol propylene oxide adduct of bisphenol A were polycondensed at 230 ° C. to obtain a polyester resin (B2-1). (B2-
The weight average molecular weight of 1) is 5400 and the number average molecular weight is 26.
00, the glass transition point was 57 ° C., and the storage elastic modulus at 170 ° C. was 1000 dyn / cm ² or less.

Production Example 10 386 parts of terephthalic acid and 1,000 parts of an ethylene oxide 2 mol adduct of bisphenol A were polycondensed at 230 ° C. to obtain a polyester resin (B2-2). (B2-
The weight average molecular weight of 2) is 4000 and the number average molecular weight is 22.
00, the glass transition point was 49 ° C., and the storage elastic modulus at 170 ° C. was 1000 dyn / cm ² or less.

Production Example 11 236 parts of terephthalic acid, 697 parts of a 2 mol propylene oxide adduct of bisphenol A and 67 parts of dodecenylsuccinic acid were polycondensed at 230 ° C. to give a polyester resin (B2
-3) was obtained. The weight average molecular weight of (B2-3) is 730.
0, number average molecular weight of 3800, glass transition point of 61 ℃,
The storage elastic modulus at 170 ° C. was 1000 dyn / cm ² or less.

Production Example 12 406 parts of 4,4'-diphenylmethane diisocyanate was reacted with 1,000 parts of an ethylene oxide 2 mol adduct of bisphenol A at 150 ° C to obtain a polyurethane resin (B3). (B3) weight average molecular weight 2700,
Number average molecular weight 1300, glass transition point 49 ° C, 170 ° C
The storage elastic modulus at was 1000 dyn / cm ² or less. Production Example 13 831 parts of Epicoat 1002 (manufactured by Yuka Shell Epoxy Co., Ltd.) as an epoxy resin, 169 parts of benzoic acid, 2 parts of tetrabutylammonium bromide and 120 parts of xylene were reacted at 150 ° C. for 4 hours, and then the solvent was removed. , Epoxy resin (B4) was obtained. Weight average molecular weight of (B4) 350
0, number average molecular weight 2040, glass transition point 52 ° C, 17
The storage elastic modulus at 0 ° C. was 1000 dyn / cm ² or less. Production Example 14 Polyamide resin (B5) was obtained by polycondensing 246 parts of dimer acid, 9 parts of acetic acid, 18 parts of benzoic acid and 60 parts of ethylenediamine with 230. The melting point of (B5) was 110 ° C. Storage modulus at 170 ° C is 1000 dyn / c
It was less than m ² .

Examples 1 to 10 A DMF 120 part was charged in a cooling pipe and a Kolben equipped with a stirrer.
The components shown in Table 1 were added, and after nitrogen replacement, the mixture was stirred at 150 ° C. for 2 hours with stirring and dissolved in DMF. After that, it was devolatilized at 180 ° C., and the toner binder (TB-
1) to (TB-10) were obtained.

[0046]

[Table 1] Resins (A) and (B) -------------------------------------- 1 TB-1 A-1 15 parts B1-1 85 copies Actual 2 TB-2 A-2 10 copies B1-2 90 copies 3 TB-3 A-2 15 copies B1-3 55 copies, B2-1 30 copies 4 TB-4 A-2 15 copies B1-3 25 parts, B2-3 60 parts 5 TB-5 A-3 35 parts B2-3 65 parts, example 6 TB-6 A-2 25 parts B1-2 45 parts, B2-3 30 parts 7 TB- 7 A-2 15 parts B1-2 55 parts, B3 30 parts 8 TB-8 A-2 15 parts B1-2 55 parts, B4 30 parts 9 TB-9 A-2 15 parts B1-2 55 parts, B5 30 Part 10 TB-10 A-2 10 parts B1-2 90 parts, low molecular weight polyolefin 3.4 parts Note) As low molecular weight polyolefin, VISCOL 550P (manufactured by Sanyo Kasei Co., Ltd.) is used.

Comparative Examples 1 to 6 The components in Table 2 were treated in the same manner as in Example 1 to obtain comparative toner binders (TB-11 to TB-16).

[0048]

[Table 2] Resins (A) and (B) ----------------------------------- Ratio 1 TB-11 C-1 15 Part B6 85 parts Comparison 2 TB-12 C-1 35 parts B6 65 parts 3 TB-13 C-1 15 parts B1-1 85 parts Example 4 TB-14 C-1 15 parts B1-3 55 parts, B2-1 30 parts 5 TB-15 C-1 35 parts B2-3 65 parts 6 TB-16 C-1 15 parts B1-2 55 parts, B-3 30 parts Obtained toner binder (TB-1 to TB-16) The analytical values of are shown in Table 3.

[0049]

[Table 3] Toner binder Mw Mn Mw / Mn Tg (° C) -------------------- TB-1 143000 2770 51.6 56 TB-2 100000 2500 40.0 59 TB-3 146000 2980 49.0 59 TB-4 150000 3000 50.0 61 TB-5 185000 3440 53.8 62 TB-6 270000 3700 73.0 61 TB-7 141000 2590 54.4 57 TB-8 140000 2610 53.6 58 TB-9 143000 2600 55.0 60 TB-10 178000 2950 60.3 59 TB-11 105000 2600 40.4 57 TB-12 245000 3500 70.0 58 TB-13 103000 2620 39.3 56 TB-14 110000 2560 43.0 57 TB-15 250000 4240 59.0 61 TB-16 104000 2680 38.8 56

Use Examples and Comparative Use Examples 7 parts of carbon black (MA100 manufactured by Mitsubishi Kasei Co., Ltd.) and 88 parts of each of the toner binders of the present invention of Examples 1 to 9 and the toner binders of Comparative Examples 1 to 6 were used. Polypropylene (manufactured by Sanyo Kasei Co., Ltd. Viscole 5
50P) and 3 parts of a charge control agent (Hodogaya Chemical Co., Ltd., Spiron Black TRH) are uniformly mixed, and then kneaded by a twin-screw extruder having an internal temperature of 150 ° C., and the cooled material is finely pulverized by a jet mill. Then, the particles were classified by a dispersion separator to obtain toners a to o having an average particle diameter of 12 μm. Further, 91 parts of the toner binder of the present invention in Example 10 was uniformly mixed with 7 parts of carbon black (MA100 manufactured by Mitsubishi Kasei Co., Ltd.) and 2 parts of a charge control agent (Spiron Black TRH manufactured by Hodogaya Chemical Co., Ltd.). After mixing, a toner p having an average particle size of 12 μm was obtained in the same manner.

Test Example 1 Coarse pulverized toner (8.6 me) was kneaded and cooled by a twin-screw extruder.
sh pass-30mesh on) was finely pulverized by a jet mill under a constant condition, and the average particle size was measured by a Coulter counter without classification, and used as a pulverization test. The results are shown in Table 4.

Test Example 2 97 parts of a ferrite carrier (F-100 manufactured by Powder Tech Co., Ltd.) was uniformly mixed with 3 parts of each of the toners a to p.
A commercially available copier (BD-7720 manufactured by Toshiba Corp.) is used to transfer the toner image onto the paper, and the transferred toner is remodeled in the fixing unit of the commercial copier (SF8400A manufactured by Sharp Co.). A fixing test was performed at a speed of 35 sheets of A4 paper / minute. The test results are as shown in Table 4.

Test Example 3 Toners a to p were placed in polyethylene bottles,
After keeping it in a constant temperature water bath at 45 ° C for 8 hours, transfer it to a 42 mesh sieve and shake it for 10 seconds using a powder tester manufactured by Hosokawa Micron Co., Ltd., measure the weight% of the toner remaining on the sieve, and store it under heat resistance. It was a sex test.
The smaller the number, the better the heat resistant storage stability. Table 4 shows the results
Shown in

Test Example 4 To 3 parts of each of toners a to p, 97 parts of a ferrite carrier (F-100 manufactured by Powder Tech Co., Ltd.) was placed in a 50 CC glass bottle, and 1 part was placed in a temperature / humidity control chamber at 25 ° C. and 50% RH.
After standing for 2 hours, the mixture was stirred at 100 rpm for 30 minutes with a Turbula shaker mixer under the conditions of 25 ° C. and 50% RH to be frictionally charged. Then, Table 4 shows the results of measurement with a blow-off charge amount measuring device manufactured by Toshiba Corporation.

[0055]

[Table 4] Toner Toner MFT HOT Heat resistance Friction Grindability Painter (℃) (℃) Storability Charge amount Average particle size * 1 * 2 (%) (μc / g) (μm) ---------- −−−−−−−−−−−−−−−−−−−−−−−−−− Actual a TB-1 140> 220 31 -21 11 b TB-2 138> 220 28 -21 9 c TB-3 136 ＞ 220 28 -20 11 d TB-4 135 ＞ 220 27 -20 11 Example e TB-5 140 ＞ 220 26 -22 12 f TB-6 138 ＞ 220 27 -22 11 g TB-7 136 > 220 30 -22 11 h TB-8 137> 220 29 -21 11 i TB-9 138> 220 27 -22 11 p TB-10 137> 220 27 -22 12 −−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−− Ratio j TB-11 140 180 30 -21 11 k TB-12 147> 220 30 -21 15 Comparison l TB- 13 140 150 31 -20 11 m TB-14 140 160 30 -20 11 Example n TB-15 140 150 27 -20 11 o TB-16 138 160 32 -20 11 −−−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−− * 1 Image density 1.2 The black solid part was rubbed by the Gakushin type robustness tester (rubbing part = paper) 5 times, and the image density of the solid part after rubbing was 70% or more. Roll temperature. * 2 Heat roll temperature when toner is hot offset

Toners a to which the binder of the present invention is used
Both i and p have an excellent balance of low-temperature fixability, hot offset resistance, and pulverizability as compared with toners j to o using comparative binders. Further, all of a to i and p showed good heat-resistant storage stability and good charging characteristics.

[0057]

INDUSTRIAL APPLICABILITY The toner binder of the present invention can have a storage elastic modulus at a high temperature larger than that of a conventional high molecular weight resin by incorporating a nitrile group into the high molecular weight resin, and the use of a smaller amount of the high molecular weight resin than before. Thus, it is possible to prevent the hot offset of the toner. At the same time, since the proportion of the low molecular weight resin is increased, the low-temperature fixability and the pulverizability at the time of toner production are improved more than ever before.

Claims (9)

[Claims] 1. A storage elastic modulus at 170 ° C. of 500,000 dyn.
/ Cm ² or more at which the resin (A) and the storage modulus at 170 ° C. is in the electrophotographic toner binder consisting of 100,000 dyn / cm ² or less is a resin (B), containing (A) is a nitrile group A toner binder for electrophotography, which is a resin. 2. A weight average molecular weight M of the toner binder.
w is 10,000 to 1,000,000 and the number average molecular weight Mn is 1,000 to
The toner binder according to claim 1, which has a Mw / Mn of 10 to 1,000. 3. The toner binder according to claim 1, wherein (A) is a copolymer of (meth) acrylonitrile and another vinyl monomer. 4. The toner binder containing 3 to 5 of (A).
The toner binder according to claim 1, which contains 0% by weight. 5. (B) is a copolymer (B1) of (meth) acrylonitrile and another vinyl monomer.
4. The toner binder according to any one of 4 above. 6. The toner according to claim 1, wherein (B) is at least one selected from the group consisting of polyester (B2), polyurethane (B3), epoxy resin (B4) and polyamide (B5). binder. 7. (B) is a copolymer (B1) of (meth) acrylonitrile and another vinyl monomer, polyester (B2), polyurethane (B3), epoxy resin (B).
The toner binder according to any one of claims 1 to 4, which is at least one selected from the group consisting of 4) and polyamide (B5). 8. The toner binder according to claim 5, wherein (B1) contains a carboxyl group. 9. The toner binder according to claim 1, wherein the toner binder contains a low molecular weight polyolefin in an amount of 0.1 to 10% by weight.