JPH0381779A - Resin composition for toner and toner - Google Patents

Abstract

PURPOSE:To improve the anti-offsetting property, fixability and blocking resistance of a toner in a wide fixing temp. range by incorporating a resin modified by the action of an org. sulfonic acid compd. CONSTITUTION:This resin compsn. contains a resin component obtd. by modifying a copolymer of a styrene monomer and/or a (meth)acrylate monomer with a vinyl monomer (A) having an acid group by the action of an org. sulfonic acid compd. (B). Mono(meth)acryloyloxyethyl ester of succinic acid may be used as the monomer A and p-toluene-sulfonic acid as the compd. Bk. The modification may be carried out by dissolving the compd. B together with the monomers before copolymn. or treating the copolymer with the compd. B added after copolymn.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resin composition for a toner used for developing electrostatic images in electrophotography and the like, and a toner using this resin composition.

(Prior art) As a method for developing electrostatic images in electrophotography,
Dry development method is often used. This dry development method uses a triboelectrically charged fine powder developer called toner, which is a resin containing a colorant such as carbon black dispersed therein.

Normally, toner charged by friction adheres to an electrostatic latent image on a photoreceptor due to electrical attraction, forming a toner image.
This toner image is then transferred onto a sheet of paper and fixed using a heated roller that has releasability to the toner.

These toners have various properties such as offset resistance (toner does not adhere to heating rollers and other cleaning rollers), fixing properties (toner firmly adheres to paper), blocking resistance (toner particles do not aggregate), etc. performance is required. In particular, a toner is required that has excellent offset resistance over a wide fixing temperature range.

Conventionally, as this type of toner resin composition and toner,
Resins made of (co)polymers whose constituent units are styrene monomers and/or (meth)acrylic acid ester monomers are widely used. In addition, resins modified by introducing carboxyl groups into such (co)polymers, reacting them with polyvalent metal compounds, and crosslinking the (co)polymers with metal ions are also used (specially Kaisho 57-1782
50 and JP-A-61-10155).

(Problems to be Solved by the Invention) An object of the present invention is to use a resin modified by a method different from the conventional modification method as described above, to achieve durability over a wide fixing temperature range. It is an object of the present invention to provide a resin composition for a toner and a toner having excellent offset properties, as well as good fixing properties and anti-blocking properties.

(Means for Solving the Problems) The toner resin m or product of the present invention is a combination of a styrene monomer or/and (meth)acrylic acid ester monomer and a vinyl monomer having an acid group. It is characterized by containing a resin obtained by modifying a copolymer by the action of an organic sulfonic acid compound as a main resin component.

Further, the toner of the present invention is characterized in that it contains the above resin composition for toner.

In the present invention, styrene monomers serving as structural units of the copolymer include styrene, 0-methylstyrene, m-
Methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- Octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, P-phenylstyrene, p-chlorostyrene, 3.
Examples include 4-dichlorostyrene. Among these, styrene is preferred.

In addition, as the (meth)acrylic acid ester monomer that becomes the structural unit of the copolymer, methyl (meth)acrylate,
Ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-octyl (meth)acrylate, dodecyl (meth)acrylate, (meth)acrylate 2-ethylhexyl acid, lauryl (meth)acrylate, stearyl (meth)acrylate, dimethylacrylate (meth)acrylate, diethylaminoethyl (meth)acrylate,
Examples include methyl α-chloroacrylate. Among these, methyl methacrylate, (meth)acrylic acid n
-butyl and 2-ethylhexyl acrylate are preferred.

In addition, as the acid group of the vinyl monomer having an acid group which is a constituent unit of the copolymer, one or more of the groups constituting carboxylic acid, sulfonic acid, sulfinic acid, phosphonic acid, boric acid, etc. Among these, carboxyl groups are preferred from the viewpoint of acid strength and ease of copolymerization.

Examples of such vinyl monomers having a carboxyl group include (meth)acrylic acid, α-ethyl acrylic acid, crotonic acid, isocrotonic acid, β-methylcrotonic acid, fumaric acid, maleic acid, itaconic acid, and the following general acids. Examples include half ester compounds represented by the formula.

(However, in formula (1), L represents a divalent bonding group having 3 or more carbon atoms and having an ester bond in the molecular chain, and R1 represents a hydrogen atom or a methyl group.) The above half-ester compound is It is obtained by an esterification reaction between a (meth)acrylic acid derivative having a hydroxyl group and an aliphatic dicarboxylic acid such as succinic acid, malonic acid, or glutaric acid or an aromatic dicarboxylic acid such as phthalic acid. Note that the dicarboxylic acid may have a hydrogen atom substituted with a halogen atom, a lower alkyl group, an alkoxy group, or the like, or may be an acid anhydride.

Such half-ester compounds include succinic acid mono(meth)acryloyloxyethyl ester and succinic acid mono(meth)acryloyloxyethyl ester.
Examples include meth)acryloyloxypropyl ester, glutaric acid mono(meth)acryloyloxyethyl ester, phthalic acid mono(meth)acryloyloxyethyl ester, phthalic acid mono(meth)acryloyloxypropyl ester, and the like.

Copolymers of the above styrene monomers and/or (meth)acrylic acid ester monomers and vinyl monomers having acid groups can be produced by solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, etc. It can be obtained by a conventionally known one-step polymerization method or two-step polymerization method.

In the present invention, the content of the styrene monomer component is 4
0 to 95% by weight, the content of (meth)acrylic acid ester monomer components is 4 to 40% by weight, and the content of vinyl monomers having acid groups is determined by the acid value of the copolymer. is 3-10
It is preferable to set the value to 0. Here, the acid value refers to 1 g of the copolymer before modification with the organic sulfonic acid compound.
This is the value expressed in the number of potassium hydroxide required to neutralize the acid groups contained in it.

If the content of the styrene monomer component is less than 40% by weight, the pulverizability of the toner may deteriorate. Furthermore, if the content of the (meth)acrylic acid ester monomer component is less than 4% by weight, the fixing properties of the toner may deteriorate. Furthermore, if the content of the vinyl monomer component having an acid group is less than 3 in acid value, the modification by the action of the organic sulfonic acid compound may not be sufficient, and the effect of improving the offset resistance of the toner may not be expressed. be. On the other hand, if the content of the vinyl monomer component having an acid group exceeds 100 in terms of acid value, the blocking resistance and fluidity of the toner may deteriorate.

Examples of organic sulfonic acid compounds that act on the copolymer include aromatic sulfonic acids such as toluenesulfonic acid, benzenesulfonic acid, and naphthalenesulfonic acid, and their metal chlorides; methanesulfonic acid, ethanesulfonic acid, and n-butanesulfonic acid. , alkylsulfonic acids such as isobutanesulfonic acid and octanesulfonic acid, and metal chlorides thereof; substituted products such as aminoethanesulfonic acid, taurine, sulfanilic acid, naphthylsulfonic acid, and sulfobenzoic acid.

In order to modify the copolymer by acting with the above-mentioned organic sulfonic acid compound, (1) when copolymerizing the above-mentioned monomers, dissolve the organic sulfonic acid compound in these monomers in advance. put. (2) After copolymerizing the monomers, an organic sulfonic acid compound is added to the system and maintained at an appropriate temperature. (
3) Add an organic sulfonic acid compound to the copolymer and knead at an appropriate temperature. The above three methods are mainly adopted.

In particular, methods (1) and (2) above are preferred from the viewpoint of uniform modification. In this case, the organic sulfonic acid compound is used at 10 mol per 1 mol of the vinyl monomer having an acid group. Hereinafter, it is particularly preferable to use it in the range of 1X10-'mol-1 mol.

In addition, the treatment temperature for modification is generally 100 to 20
0°C is preferred.

The copolymer resin obtained by the above treatment has an increased molecular weight and melt viscosity compared to the untreated copolymer resin, which indicates that the copolymer has been modified. The modified resin preferably has a glass transition temperature of 40° C. or higher. Glass transition temperature is 40
If the temperature is lower than °C, the blocking resistance and fluidity of the toner may deteriorate. The number average molecular weight of the modified resin is preferably in the range of 30,000 to 300,000. Thus, the toner resin composition of the present invention is produced.

The toner resin composition of the present invention may contain polystyrene, polyvinyl acetate, polyvinyl chloride, polyamide resin, polyethylene, polypropylene, polyester resin, acrylic resin, styrene resin, etc. within the range that can achieve the object of the present invention. Resins such as butadiene copolymer resins and epoxy resins and other additives may be mixed.

To produce a toner using the resin composition for toner of the present invention, for example, a colorant such as carbon black and other conventional toner additives may be added to the resin composition using a ribbon blender, Hensel 5, etc. A method of mixing in a mixer etc., melting and kneading this using a roll mill, a kneader 1 extruder, etc. at a temperature of, for example, 100 to 200°C, cooling and pulverizing, or the above-mentioned (1) to In the modification method (3), when adding the organic sulfonic acid compound, a colorant such as carbon black and other toner additives are mixed,
Mainly employed is a method in which the obtained composition is melt-kneaded, cooled, and pulverized. In this way, the toner of the present invention is manufactured.

(Function) According to the present invention, the styrenic monomer or/and (meth)
A copolymer of an acrylic acid ester monomer and a vinyl monomer having an acid group is modified by the action of an organic sulfonic acid compound, resulting in an increase in molecular weight and melt viscosity compared to an unmodified copolymer. do. Although the mechanism by which the copolymer is modified in this way is not yet fully clear, the organic sulfonic acid compound acts catalytically to modify the acid group portion of the copolymer, or the acid group portion and the ester bond portion. It is presumed that crosslinking occurs in this step, thereby resulting in good anti-offset properties, fixing properties, and anti-blocking properties.

(Example) Examples and comparative examples of the present invention are shown below.

1 yen 1 62.5 parts by weight of styrene, 15 parts by weight of methyl methacrylate, 15 parts by weight of n-butyl acrylate, 7 parts by weight of methacrylic acid
．． 5 parts by weight, and benzoyl peroxide (
A mixture of 1.5 parts by weight of BPO) and 0.1 parts by weight of p-toluenesulfonic acid was added dropwise to 50 parts by weight of toluene under reflux over 2.5 hours to carry out solution polymerization. went.

After the addition was completed, the mixture was further aged for 1 hour while stirring at the boiling temperature of toluene.

Then, while gradually increasing the temperature of the system to 180°C,
Toluene was removed under reduced pressure to obtain a resin.

This resin was cooled and pulverized to produce a flaky toner resin composition. This toner resin composition had a number average molecular weight of 13,000 and a glass transition temperature of 78°C. The acid value of the copolymer before modification (copolymer polymerized without adding p-toluenesulfonic acid separately) is 45.
Met.

100 parts by weight of this resin composite for toner and 5 parts by weight of carbon black (Diablack SH: manufactured by Mitsubishi Kasei Corporation) were roll-kneaded at 170°C for 10 minutes, and after cooling, coarsely pulverized.
Furthermore, it is finely pulverized with a jet mill to an average particle size of 13 to 15.
μ, and 0.5 parts by weight of hydrophobic silica fine powder was mixed therein to produce a toner.

Take 10g of this toner in a 100d beaker and
The sample was left in a constant temperature bath at °C for 3 hours, and the blocking resistance was evaluated based on the presence or absence of particle coalescence. As a result, the blocking resistance was good.

A fine powder developer is prepared by mixing 4 parts by weight of this toner with 96 parts by weight of an iron powder carrier having an average particle size of 50 to 80 μm.
The fixing temperature range was measured by attaching the fixing device to a modified machine (X 2500). This fixing temperature range was determined by changing the temperature setting of the heating roller for fixing, and was determined by setting the temperature at which good fixing was achieved without causing offset. As a result, the fixing temperature range is 170
Good fixing was possible over a wide temperature range from °C to 205 °C. Further, the charged state of the toner particles was stable, and the copied image was clear without any fogging.

1JI 80 parts by weight of styrene, 16 parts by weight of n-butyl acrylate, 4 parts by weight of methacryloyloxyethyl succinate, and 1 part by weight of benzoyl peroxide (BPO) as a polymerization initiator.
．． Solution polymerization was carried out by dropping a mixture of 5 parts by weight into 50 parts by weight of toluene under reflux over 2.5 hours. After dropping, add 0 p-toluenesulfonic acid to this.
．． 5 parts by weight were added and further aged for 1 hour while stirring at the boiling temperature of toluene. The subsequent steps were carried out in the same manner as in Example 1.

In this case, the number average molecular weight of the toner resin composition is 12,
500, and the glass transition temperature was 68°C.

Note that the acid value of the copolymer before modification (a copolymer polymerized without adding p-)luenesulfonic acid separately) was 8.

Further, the toner had good anti-blocking properties, and the fixing temperature range using the fine powder developer was 170'C to 205°C, and good fixing was possible over a wide temperature range. Further, the charged state of the toner particles was stable, and the copied image was clear without any fogging.

1 liter 78 parts by weight of styrene, 20 parts by weight of n-butyl acrylate, 2 parts by weight of acryloyloxyethyl succinate, and 2.0 parts of benzoyl peroxide (BPO) as a polymerization initiator.
Dissolve 1.5 parts by weight of p-toluenesulfonic acid and add 1.5 parts by weight of p-toluenesulfonic acid.
Solution polymerization was carried out in the same manner as in Example 1 using a mixture in which parts by weight were dissolved.

The number average molecular weight of the obtained toner resin composition was 9.80.
0, the glass transition temperature was 84°C. Note that the acid value of the copolymer before modification (a copolymer polymerized without adding p-)luenesulfonic acid separately) was 5.

In addition, the toner obtained in the same manner as in Example 1 had good anti-blocking properties, and the fixing temperature range using the fine powder developer was 170°C to 210"C, and good fixing was possible over a wide temperature range. Further, the charged state of the toner particles was stable, and the image of the copy was clear without any fogging.

60 parts by weight of fruit 1 eye ustyrene, 20 parts by weight of methyl methacrylate,
10 parts by weight of n-butyl methacrylate, 10 parts by weight of acrylic acid, and benzoyl peroxide (BPO) as a polymerization initiator.
Solution polymerization was performed in the same manner as in Example 2 using a mixture in which 2.0 parts by weight of p-toluenesulfonic acid was dissolved, and 0.05 parts by weight of p-toluenesulfonic acid was added to the system. processed.

The number average molecular weight of the obtained toner resin composition was 10.7.
00, the glass transition temperature was 81'C. Note that the acid value of the copolymer before modification (a copolymer polymerized without separately adding p4 luenesulfonic acid) was 62.

Furthermore, the toner obtained in the same manner as in Example 1 had good anti-blocking properties, and the fixing temperature range using the fine powder developer was 170°C to 210°C, and good fixing was possible over a wide temperature range. Ta. Further, the charged state of the toner particles was stable, and the copied image was clear without any fogging.

The same procedure as in Example 1 was carried out except that 0.1 part by weight of p-toluenesulfonic acid was not added.

In this case, the fixing temperature range was 160°C to 185°C, which was narrower than in Example 1.

History Apparatus 1 The same procedure as in Example 2 was carried out except that 0.5 parts by weight of p-toluenesulfonic acid was not added.

In this case, the fixing temperature range is 160'C-185°C
It was narrower than in Example 2.

(Effects of the Invention) As described above, the toner resin composition and toner of the present invention contain a styrene monomer or/and a (meth)acrylic acid ester monomer and a vinyl monomer having an acid group. The copolymer has been modified by the action of an organic sulfonic acid compound, and as a result has excellent offset resistance over a wide fixing temperature range, as well as good fixing and blocking resistance. Furthermore, the charged state of the toner particles is stable, and the resulting images are clear and free of fog.

Therefore, the toner resin composition and toner of the present invention can be suitably used in an electrophotographic copying machine using a heating roller fixing method ranging from low speed to high speed.

Claims (1)

[Claims] 1. A copolymer of a styrene monomer or/and (meth)acrylic acid ester monomer and a vinyl monomer having an acid group is modified by the action of an organic sulfonic acid compound. 1. A resin composition for a toner, characterized in that it contains a resin produced by a synthetic resin as a main resin component. 2. A toner comprising the toner resin composition according to claim 1.