JPS5893065A - Binder for electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain storage stability suited for high speed fixing by causing a copolymer of a vinyl monomer contg, glycidyl groups and an other vinyl monomer and a cross-linkable compd. having functional group that can react with the glycidyl groups when heated to react thereby forming a binder. CONSTITUTION:The material obtd. by compounding a copolymer prepd. by copolymerization of 0.1-5.0wt% a vinyl monomer contg. glycidyl groups or a vinyl monomer contg. beta-methyl glycidyl groups and 95-99wt% an another vinyl monomer and having >=30 deg.C Tg, and a cross-linkable compd. having at least 1 kind and >=2 pieces of functional groups that can react with the above-mentioned glycidyl groups and beta-methyl glycidyl groups when heated in one molecule in such a way that the above-mentioned functional groups is contained at 0.3- 1.5 equiv. based on the glycidyl groups and beta-methyl glycidyl groups in the above-described copolymer and causing both to react is used as a binder.

Description

[Detailed description of the invention] The present invention relates to a binder for electrophotographic toner.

In recent years, electrophotography has required high-speed recording, and high-speed fixing using heat rolls has become necessary.
At present, a binder resin that simultaneously satisfies storage stability, offset resistance, and fixing properties suitable for such high-speed fixing has not been obtained.

However, the inventors of the present invention have conducted extensive studies in view of these actual circumstances, and have found that a specific vinyl copolymer containing (β-methyl)glycidyl groups and a functional group that can react with these groups when heated. It has been discovered that a resin obtained by reacting with a crosslinking compound containing two or more of the same or different types of compounds can simultaneously satisfy the various required properties as described above. As a result, we have completed the present invention.

That is, the present invention provides a glass transition method obtained from a vinyl monomer containing a glycidyl group and/or a vinyl monomer containing a β-methylglycidyl group, and another vinyl monomer that is copolymerizable with the vinyl monomer. A copolymer (4) having a point (hereinafter abbreviated as Tg) of 30°C or higher, and the copolymer (4)
4) A crosslinkable compound having one or more functional groups and having two or more functional groups that reacts well with the glycidyl group and/or β-methylglycidyl group contained in B) upon heating.
are blended in such a way that the amount of these functional groups is 13 to 15 equivalents to the glycidyl group and/or β-methylglycidyl group in the copolymer (4), and (4), (
The present invention provides a binder for electrophotographic toner, which is made by reacting both of B) and is suitable for high-speed fixing with a heat roll and has excellent storage stability and offset resistance.

Here, the above-mentioned copolymerization is a copolymer of a vinyl monomer containing a glycidyl group and/or a vinyl monomer containing a glycidyl group and another vinyl monomer that can be copolymerized with it. It refers to a copolymer with a Tg of 66°C or higher that can be obtained by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization. Typical monomers containing a glycidyl group or vinyl monomers containing a β-methylglycidyl group include glycidyl (meth)acrylate 1. β-methylglycidyl (
Examples include meth)acrylate or allyl glycidyl ether, but the amount used is 11% of the total monomers.
~5.0% by weight. When this amount is less than 0.1%, a sufficient effect can be obtained;
: When exceeding 1, toner reacts with carbon black and the like during toner production, making toner of stable quality no longer superior. In addition, other typical monomers used to obtain the copolymer (4) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and (meth)acrylate. ) butyl acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, furfuryl (meth)acrylate, (meth)acrylate Tetrahydrofurfuryl acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate or (
(meth) such as diethylaminoethyl acrylate
Acrylic compounds such as esters of acrylic acid and (meth)acrylonitrile or (meth)acrylamide;
Aromatic vinyl monomers such as styrene, vinyltoluene or α-methylstyrene; unsaturated dibasic acid nosialkyl esters such as maleic acid, fumaric acid or itaconic acid; vinegar 11 vinyl (also includes vinyl alcohol).
, vinyl propionate, vinyl chloride, vinylpyrrolidone, ethylene, propylene or butylene, etc. can be used. T
It is appropriate that g is 30°C or higher, preferably 50°C or higher. If the temperature is lower than 60°C, storage stability will deteriorate, which is not preferable.

On the other hand, the above-mentioned structural compound (B) is selected from carboxyl groups, amino groups, aromatic hydroxyl groups, etc. that can react with the glycidyl group and /l or β-methylglycidyl group present in the copolymer compound. It refers to a compound having at least one type of functional group with a total of two or more functional groups, and representative examples include succinic acid, adipic acid, pimelic acid, sebacic acid, azelaic acid, and dodecane acid. acids such as brassylic acid, hexadecanniic acid, icosanniic acid, phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, trimellitic anhydride, biamellitic acid or butanetetracarboxylic acid. Basic acids polyhydric amines such as diamino diphenylmethane, diaminodiphenylsulfone or diaminobenzene; polyhydric phenols such as bisphenol A, paraisopropylphenol dimer or novolac; oxycarboxylic acids such as paraoxybenzoic acid, malic acid, tartaric acid or citric acid. Acids; aminocarboxylic acids such as para-aminobenzoic acid, aspartic acid, glutamic acid, lysine or aminoundecanoic acid; niaminophenols; or an average of 2 to 6 carboxyl groups per molecule at the end of the molecule, aromatic hydroxyl groups and/or Examples include polyester resins, polyamide resins, polyurethane resins, and polyvinyl resins containing amino groups.

The blending ratio of the compound (B) to the copolymer M34C is determined based on the proportion of the copolymer (glycidyl group and/or β-methylglycidyl group contained in N) (here, the glycidyl group and β-methylglycidyl group When both of these coexist, the ratio is such that the functional group in the compound-B) that can react with the (β-methyl)glycidyl group is 13 to 15 equivalents to the total amount of both). .

If this ratio is less than 0.3 equivalent, excess (β
-Methyl)glycidyl group reacts with carbon black etc., making stable toners less desirable, and conversely, 1.5
If the amount exceeds the equivalent amount, sharp images cannot be obtained, so both are not preferred.

The binder of the present invention comprises each of the above-mentioned copolymers (
4) and the structural compound (B), but within the scope that does not impair the purpose of the present invention,
Prior to or after this reaction, a well-known and commonly used resin such as polyester resin, acrylic resin, coumaron resin, xylene resin, epoxy resin, polyester resin, polyamide resin, rosin-modified maleic acid resin, polyvinyl chloride or waxes may be used. Of course, various additives such as a pigment dispersant, a charge control agent, or a fluidity control agent can be mixed therein, and there is no hindrance to the mixing of such resins or additives.

Next, the present invention will be specifically described with reference to Examples, where all parts and parts are based on weight unless otherwise specified.

Example 1 A mixture of glycidyl methacrylate, n-butyl methacrylate, and styrene was copolymerized in the presence of a polymerization initiator, azobisisobutyronitrile, to complete the reaction. Afterwards, kijiroru was removed under reduced pressure to obtain an excellent Tg of 75°C, and
After sufficiently mixing 100 parts of a solid copolymer with an average molecular weight of 8,000 with 6 parts of adipic acid Q and 10 parts of carbon black in a Henschel mixer, the mixture was heated at 150°C using a hot roll. After reacting with kneaded meat for 10 minutes,
It was cooled and ground to produce a toner.

Using this toner, a high-speed copying machine (manufactured by Fuji Xerox Co., Ltd. [
As a result of copying at 4000 J), clear images with no staining were obtained even after 24 hours of continuous use.

Moreover, both offset resistance and storage stability were good.

Example 2 The composition of the monomer mixture was changed to methacrylic acid glycidyl ester to-, methacrylic acid β-methylambda glycidyl ester Q
, 5-, 35 liters of methyl methacrylate, 45% styrene, and diethyl fumarate 1&5- A polymer was obtained. 10 of this copolymer
After thoroughly mixing 0 parts of isophthalic acid with 10 parts of isophthalic acid using a Henschel mixer, the mixture was reacted for 15 minutes at 160°C using a hot roll, and further 10 parts of carbon black was added and kneaded at 150°C for 10 minutes, and then cooled. After nine months, it was crushed to produce toner.

Copying was carried out in the same manner as in Example 1, except that this toner was used, and as a result, even after 24 hours of continuous use, clear copies with no contamination were obtained. Moreover, both offset resistance and storage stability were good.

Example 3 5 parts of hexamethylene diamine were added to 100 parts of the solid copolymer obtained in Example 1 and 4 moles of adipic acid.
2.0 parts of a polyamide resin with a number average molecular weight of t000 obtained by a condensation reaction in a molar ratio were mixed and reacted at 150°C for 10 minutes using a hot roll, and further 10 parts of carbon black was added and heated. After kneading with a roll for 10 minutes, it is cooled and crushed to obtain toner.

Example 1 except that this toner was used.
As a result of copying in the same manner as above, clear images with no contamination were obtained even after 24 hours of continuous use.
oooII, vinyl acetate λooooy, vinyl benzoate λ
000I, glycidyl methacrylate) 19011. Colloidal palladium (Q, 1-aqueous solution) 21[1,,ir emal 0'' (sodium lauryl sulfate manufactured by Daiichi Kogyo Seiyaku ■) 120JI and hydroxyethyl cellulose 20J
', then blow in propylene twice to remove air, and then reduce the propylene pressure to 100 kll.
It was heated to 40°C as d. Then potassium persulfate 2
A catalyst solution in which 0I was dissolved in 500j' of ion-exchanged water was mixed with 6
By carrying out the reaction while dropping over a period of time, vinyl acetate 3
An emulsion of a copolymer consisting of 52% vinyl 6-1 benzoate, 54% propylene and 2% glycidyl methacrylate was obtained.

Next, a saline solution was added to this emulsion to precipitate the copolymer, which was washed with water and dried to obtain a solid copolymer having a Tg of 52°C.

16 parts of adipic acid and 10 parts of carbon black were blended with 100 parts of this copolymer, thoroughly mixed in a Henschel mixer, and subjected to kneading reaction at 150°C for 15 minutes using a hot roll, and then cooled. The powder was crushed to produce a toner.

Copying was carried out in the same manner as in Example 1, except that this toner was used, and as a result, a clear image with no staining was obtained even after 24 hours of continuous use.

Claims (1)

[Claims] (g) Vinyl monomer containing a glycidyl group and/or vinyl monomer containing a β-methylglycidyl group 8
．． A copolymer having a glass transition point of 60° C. or higher obtained by copolymerizing 1 to 5.0 weight of vinyl monomer with 95 to 999 weight of another vinyl monomer copolymerizable with the above. Contains at least one type of functional group in one molecule and two or more functional groups that can react with the glycidyl group and /l or β-methylglycidyl group contained in the copolymer (conversion) during heating. The crosslinkable compound is added to the copolymer (g) so that the amount of the functional group is the glycidyl group and/or
Alternatively, a binder for an electrophotographic toner obtained by reacting both of the above c) and (J3) in an amount of 13 to 115 equivalents relative to the β-methylglycidyl group.