JPH0363663A - Resin composition for toner and toner - Google Patents

Abstract

PURPOSE:To improve the anti-offsetting property, fixability and blocking resistance of a toner over a wide fixing temp. range by incorporating specified two kinds of resins. CONSTITUTION:This compsn. contains 100 pts. wt. resin (A) and 1-30 pts. wt. resin (B). The resin A has >=40 deg.C glass transition point and residual carboxyl groups and is obtd. by allowing a copolymer of a styrene monomer with a (meth)acrylic ester monomer and a vinyl monomer having a carboxyl group to react with a compd. of a multivalent metal such as ZnO. The resin B is a copolymer of >=50 wt.% vinyl monomer having a (beta-methyl)glycidyl group, e.g., glycidyl methacrylate with other vinyl monomer and has >=50,000 wt. average mol. wt.

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 a wide fixing temperature range, offset resistance (toner does not adhere to heating rollers or other cleaning rollers), fixing properties (toner firmly adheres to paper), and blocking resistance (toner particles do not adhere to the paper). performance such as non-agglomeration) is required.

Conventionally, as this type of toner resin composition and toner,
It has been proposed to use a metal ion crosslinked resin obtained by reacting a polymer having a carboxyl group with a polyvalent metal compound (see JP-A-57-178250 and JP-A-61-110155).

(Intelligence to be Solved by the Invention) Although such conventional toner resin compositions and toners have relatively good performance as described above, they still have insufficient anti-offset properties particularly over a wide fixing temperature range. In particular, in order to more effectively prevent offset, a cleaning roller may be attached to the heating roller for fixing.
There is a problem in that toner accumulates on this cleaning roller, causing a so-called roller stain phenomenon.

The present invention solves the above problems, and aims to have excellent offset resistance over a wide fixing temperature range, as well as good fixing and blocking resistance, and to reduce the roller fouling phenomenon. An object of the present invention is to provide a resin composition for a toner and a toner that are significantly improved.

(Means for Solving the Problems) The resin composition for toner of the present invention comprises a styrene monomer and (
It is obtained by reacting a polyvalent metal compound with a copolymer of a meth)acrylic acid ester monomer and a vinyl monomer having a carboxyl group, and when the glass transition point is 40°C or higher, the residual carboxyl group is removed. Resin (A) with 100m! 1
A copolymer of a vinyl monomer having a glycidyl group or a β-methylglycidyl group and another vinyl monomer, the vinyl monomer having a glycidyl group or a β-methylglycidyl group. Body component content is 50% by weight
Resin (B) whose weight average molecular weight is 50,000 or more 1 to
30 parts by weight as a main component.

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

In the present invention, the styrene monomer used in the resin (A) includes styrene, O-methylstyrene, m-dimethylstyrene p-methylstyrene, α-methylstyrene,
p-ethylstyrene, 2,4-dimethylstyrene, p-
n-butylstyrene, p4ert-butylstyrene, p
-n-hexylstyrene, p-n-octylstyrene,
pn-nonylstyrene, Pn-decylstyrene, p-
Examples include n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, and the like.

Among these, styrene is preferred.

In addition, as the <meth)acrylic acid ester monomer,
Methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, (meth)acrylic acid n
-butyl, isobutyl (meth)acrylate, n-octyl (meth)acrylate, dodecyl (meth)acrylate,
Examples include 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethyla-ternoethyl (meth)acrylate, and methyl α-chloroacrylate. It will be done. Among these, methyl methacrylate, n-butyl (meth)acrylate, and 2-ethylhexyl acrylate are preferred.

In addition, examples of vinyl monomers having a carboxyl group include (meth)acrylic acid, α-ethyl acrylic acid, crotonic acid, isocrotonic acid, β-methyl crotonic acid, fumaric acid, maleic acid, itaconic acid, and the following: Examples include half ester compounds represented by the general 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 RI 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. 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.

In addition, as the metal of the polyvalent metal compound, Cu, Ag5B
e,, Mg, Ca5Sr, Ba, Zn, Cd5A
j! , Ti, Ge5Sn, V, Cr.

Examples include Mo, Mn, Fe5Co, Ni, and the like.

Among these metals, alkaline earth metals and zinc group metals are preferred, with Mg and Zn being particularly preferred.

These polyvalent metal compounds include fluorides, chlorides, chlorates, bromides, iodides, oxides, hydroxides, sulfides,
sulfites, sulfates, selenides, tellurides, nitrides,
Examples include lower alkyl metal compounds such as nitrates, phosphides, phosphinates, phosphates, carbonates, orthosilicates, acetates, oxalates, and methylated and ethylated compounds.

Among these, acetates and oxides are preferred.

In the resin (A), the copolymer of a styrene monomer, a (meth)acrylic acid ester monomer, and a vinyl monomer having a carboxyl group can be polymerized by solution polymerization, suspension polymerization, emulsion polymerization, or bulk polymerization. It can be obtained by a conventionally known one-step polymerization method or two-step polymerization method such as polymerization. in this case,
- In general, the content of the styrene monomer component is 40 to 95% by weight, preferably 60 to 90% by weight, and the content of the (meth)acrylic acid ester monomer component is 4 to 40% by weight, preferably is copolymerized so that the content of the vinyl monomer component having a carboxyl group is 1 to 20% by weight, preferably 2 to 10% by weight.

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 a carboxyl group is less than 1% by weight, the reaction with the polyvalent metal compound and resin (B) will be insufficient, and the effect of improving the offset resistance of the toner will be reduced. It may not occur. On the other hand, if the content of the vinyl monomer component having a carboxyl group exceeds 20% by weight, the environmental dependence of the toner may deteriorate (for example, the charging stability and blocking resistance under high temperature and high humidity may deteriorate). ).

In order to react the polyvalent metal compound with the copolymer, preferably, the copolymer is solution-polymerized, and then the polyvalent metal compound dispersed in an organic solvent is added to the system as necessary. The reaction is carried out by heating to a certain temperature, and then the solvent is distilled off to produce the resin (A). In some cases, the polyvalent metal compound may be dispersed in the system together with an organic solvent before starting the polymerization reaction of the copolymer.

In addition, a polyvalent metal compound is mixed with the copolymer obtained by solution polymerizing the copolymer and then distilling off the solvent.
The resin (A) may be produced by melt-kneading at an appropriate temperature using a kneader-1 extruder or the like.

It is preferable to react the polyvalent metal compound in an amount such that the molar ratio to the vinyl monomer component having a carboxyl group is 0.1 to 1.

If the molar ratio of the polyvalent metal compound is less than 0.1, the reaction with the carboxyl group-containing vinyl monomer component may be insufficient, and the effect of improving the offset resistance of the toner may not be exhibited. Moreover, the heating reaction temperature is generally preferably 100 to 200°C.

In the present invention, the vinyl monomer having a glycidyl group or β-methylglycidyl group used in the resin (B) includes glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, allyl glycidyl ether, etc. Can be mentioned.

In addition, other vinyl monomers to be copolymerized with the vinyl monomer having a glycidyl group or β-methylglycidyl group include the styrene monomer used in the resin (A), (meth)acrylic acid, Other examples include ester monomers, vinyl acetate, vinyl propionate, vinyl chloride, ethylene, propylene, and the like. Among these, it is preferable to use a styrene monomer or both a styrene monomer and a (meth)acrylic acid ester monomer.

In the resin (B), a copolymer of a vinyl monomer having a glycidyl group or a β-methylglycidyl group and another vinyl monomer can be prepared by conventional methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization. It can be produced by a known one-step polymerization method or two-step polymerization method. In this case, it is preferable to copolymerize so that the content of the vinyl monomer component having a glycidyl group or β-methylglycidyl group is 50% by weight or more. The content of the vinyl monomer component having a glycidyl group or β-methylglycidyl group is 50
If the amount is less than 1% by weight, the reaction with the resin (A) may be insufficient and the effect of improving the offset resistance of the toner may not be exhibited.

It is preferable that the resin (A) and resin (B) produced by the above method both have a glass transition temperature of 40"C or higher. If the glass transition temperature is lower than 40"C, the toner It may cause deterioration of quenching resistance and fluidity. In addition, the weight average molecular weight of the resin (A) is 50,000 to 5
The weight average molecular weight of the resin (B) is preferably 50,000 or more, and more preferably 50,000 to 300,000.

When the weight average molecular weight of the resin (B) is less than 50,000, the effect of improving roller staining becomes small.

In the present invention, a resin composition for toner is prepared by mixing or kneading the resin (A) and resin (B). The blending ratio of resin (A) and resin (B) varies depending on the amount of residual carboxyl groups, glycidyl groups or β-methylglycidyl groups, but generally resin (B) is mixed with 100 parts by weight of resin (A). Resin (B) preferably in a range of 1 to 30 parts by weight, more preferably in a range of 2 to 10 parts by weight.
If the amount is less than 1 part by weight, the reaction with the resin (A) may be insufficient and the effect of improving the offset resistance of the toner may not be exhibited. On the other hand, when the amount of resin (B) exceeds 30 parts by weight, the effect of improving roller staining becomes small.

In particular, the weight average molecular weight of the resin (B) is relatively large, the content of the vinyl monomer component having a glycidyl group or β-methylglycidyl group in the resin (B) is relatively high, and the composition of the resin (B) is A relatively small amount is effective for anti-offset properties and prevention of roller fouling.

To mix or knead resin (A) and resin (B),
Resin (A) and resin (B) are finely pulverized and mixed using a ribbon blender, Hensel [mixer, etc.], or resin (A) and resin (B) are mixed using a roll mill, kneader-1 extruder, etc. For example, the resin (A) and the resin (
After dissolving and mixing B) in an organic solvent, the solvent may be distilled off to form a fine powder. In this way, the resin composition for toner of the present invention is produced.

The toner resin composition of the present invention may contain polystyrene, polyvinyl acetate, polyvinyl chloride, boria resin, polyethylene, polypropylene, polyester resin, acrylic resin, Resins such as epoxy resins and other additives may be mixed.

In order to produce a toner using the resin composition for toner of the present invention, a finely pulverized product of the resin (A) and resin (B) is added to the resin composition.
A coloring agent such as carbon black and other conventional toner additives may be mixed as necessary with a ribbon blender, Hensel mixer, etc., or a coloring agent such as carbon black or other additive may be added to the resin (A) and resin (B). If necessary, conventionally known toner additives are mixed, and the mixture is melt-kneaded using a roll mill, kneader-1 extruder, etc. at a temperature of, for example, 100 to 200°C, cooled, and pulverized. In this way, the toner of the present invention is produced.

(Function) The toner resin composition and toner of the present invention contain, as constituent components, a copolymer of a styrene monomer, a (meth)acrylic acid ester monomer, and a vinyl monomer having a carboxyl group. The toner is obtained by reacting (metal ion crosslinking) with a polyvalent metal compound and contains a resin (A) having a glass transition point of 40°C or higher and a residual carboxyl group, so it has good durability like the conventional toner. It has offset properties, fixing properties, and anti-blocking properties.

Furthermore, a copolymer of a vinyl monomer having a glycidyl group or a β-methylglycidyl group and another vinyl monomer as a constituent component, the vinyl having the above-mentioned glycidyl group or β-methylglycidyl group. It contains 1 to 30 parts by weight of a resin (B) having a content of monomer components of 50% by weight or more and a weight average molecular weight of 50,000 or more per 100 parts by weight of the resin (A). The glycidyl group or β-methylglycidyl group of the resin (B) is the same as that of the resin (A).
) reacts well with the remaining carboxyl groups (crosslinking reaction) when heated. Therefore, it is presumed that this is because the (crosslinking) reaction between resin (A) and resin (B) progresses during the toner manufacturing process and toner usage process, increasing the molecular weight of the resin. In comparison, offset resistance is improved and roller fouling is significantly improved.

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

1'1 of A: 100 parts by weight of a copolymer consisting of 75% by weight of a styrene component, 10% by weight of a butyl acrylate component, 10% by weight of a methyl methacrylate component, and 5% by weight of a monomethacryloyloxyethyl succinate component; Zinc oxide 0.7! After stirring and reacting the toluene with reflux for 2 hours, the toluene was distilled off and the weight average molecular weight was 210,000 and the glass transition point was 6.
Resin (A)-1 having a residual carboxyl group at 2°C was produced.

The weight average molecular weight was determined by gel permeation chromatography (
GPC). Further, the glass transition point was measured using a differential scanning calorimeter (DSC).

Raw production including styrene component 80% by weight and butyl methacrylate component 18%
Copolymer 1 consisting of % by weight and 2% by weight of acrylic acid component
00 parts by weight and 0.7 parts by weight of calcium acetate were reacted in the same manner as in Production Example 1 to obtain a resin (A
)-2 was produced.

(A)゛3 Copolymer 1 consisting of 85% by weight of styrene component, 12% by weight of butyl acrylate component, and 3% by weight of methacrylic acid component
00 parts by weight and 0.6 parts by weight of magnesium oxide were reacted in the same manner as in Production Example 1 to obtain a weight average molecular weight of 180,000,
Resin (A)-3 having a residual carboxyl group and having a glass transition point of 61°C was produced.

B'1 After polymerizing glycidyl methacrylate, styrene, and butyl acrylate in the presence of a polymerization initiator azoisobutyronitrile under refluxing toluene for 2.5 hours, toluene was distilled off and methacrylate A copolymer consisting of 55% by weight of a glycidyl acid component, 35% by weight of a styrene component, and 10% by weight of a butyl acrylate component, a resin having a glycidyl group with a weight average molecular weight of 220,000 and a glass transition point of 52°C (B>-
1 was manufactured.

1 Glycidyl methacrylate, styrene, and butyl methacrylate are polymerized in the same manner as in Production Example 1 to form 60% by weight of the glycidyl methacrylate component, 25% by weight of the styrene component, and butyl methacrylate. A copolymer consisting of 15% by weight of components, weight average molecular weight 1,70,000, glass transition point 55°C
Resin (B)-2 having a glycidyl group was produced.

B-3 Glycidyl acrylate and styrene are polymerized in the same manner as in Production Example 1 to obtain a copolymer consisting of 70% by weight of glycidyl acrylate component and 30% by weight of styrene component,
Resin (B)-3 having a glycidyl group with a weight average molecular weight of 120,000 and a glass transition point of 50°C was produced.

``Ih1'' of ``B'' Glycidyl methacrylate, styrene, and butyl acrylate were polymerized in the same manner as in Production Example 1, and 30% by weight of the glycidyl methacrylate component, 55% by weight of the styrene component, and 15 butyl acrylate components were added. A glycidyl group-containing resin (B')-1 having a weight average molecular weight of 20,000 and a glass transition point of 57 DEG C. was produced from a copolymer consisting of % by weight.

[2] Glycidyl methacrylate, styrene, methyl methacrylate, and butyl acrylate were polymerized in the same manner as in Production Example 1, and 5% by weight of the glycidyl methacrylate component, 75% by weight of the styrene component, and methyl methacrylate were obtained. Resin (B')-2 having a glycidyl group and having a weight average molecular weight of 150,000 and a glass transition point of 68° C. was produced from a copolymer consisting of 10% by weight and 10% by weight of a butyl acrylate component.

1 Dankan 1 Roll 1,100 parts by weight of resin (A), 1.6 parts by weight of resin (B), and 5 parts by weight of carbon black (Diablack sH: manufactured by Mitsubishi Chemical Corporation) at 170°C for 10 minutes. The mixture was kneaded, cooled, coarsely pulverized, and further finely pulverized with a jet mill to produce a toner having an average particle size of 11 μm.

10 g of this toner was placed in a 100-degree beaker and left in a constant temperature bath at 60° C. for 24 hours, and blocking resistance was evaluated based on whether or not the particles coalesced. As a result, the blocking resistance was good.

A fine powder developer using this toner is transferred to an electrophotographic copying machine (
11-Bix 2500 (manufactured by Konica) was installed on a modified machine to measure the fixing temperature range. This fixing temperature range is
The set temperature of the heating roller for fixing was changed to show the set temperature that allows good fixing without causing offset. As a result, the fixing temperature range was 160° C. to 240° C., and good fixing was possible over a wide temperature range.

Furthermore, the fixability of images obtained by setting the temperature of the heating roller for fixing at 170° C. was measured. The fixability was determined by rubbing the image with a fastness tester and using a Macbeth densitometer to show the image retention rate. As a result, the fixability was 9
It was good at 3%.

Furthermore, after 20,000 copies were made in succession, the cleaning roller was visually evaluated for dirtiness on a five-point scale from 1 (best) to 5 (worst), and the evaluation result was 2, which was good. Furthermore, the charged state of the toner particles was stable, and the resulting images were clear and free of fog.

The above results are summarized in Table 1. In the resin composition shown in the table, the polyvalent metal ion (polyvalent metal compound) is the polyvalent metal compound relative to 100 parts by weight of the copolymer constituting the resin (A). It is indicated by the number of parts.

Example 1 was carried out in the same manner as in Example 1, except that 2,100 parts by weight of resin (A) and 2,7 parts by weight of resin (B) were used.

The results are summarized in Table 1.

1Ken JLI Resin (A) - 3,100 parts by weight and Resin (B) - 3,15
The same procedure as in Example 1 was conducted except that parts by weight were used. The results are summarized in Table 1.

1 Indigo 1 1,100 parts by weight of resin (A) and 1,6 parts by weight of resin (B')
The same procedure as in Example 1 was conducted except that parts by weight were used.

The results are summarized in Table 1.

Resin (AL2.100 parts by weight and resin (B') -2.15
The same procedure as in Example 1 was conducted except that parts by weight were used.

The results are summarized in Table 1.

Except that only 1100 parts by weight of resin (A) was used.
The same procedure as in Example 1 was carried out.

The results are summarized in Table 1.

(Effects of the Invention) As described above, the toner resin composition and toner of the present invention contain a specific resin (A) having a residual carboxyl group and a specific resin (B) having a glycidyl group or a β-methylglycidyl group. As a result, it has excellent anti-offset properties over a wide fixing temperature range, good fixing properties and anti-blocking properties, and furthermore, the roller staining phenomenon is greatly improved. Furthermore, the charged state of the toner particles is stable, and the resulting images are clear and free of fog.

Therefore, the resin composite for toner and toner of the present invention can be suitably used in electrophotographic copying machines of a heated roller fixing system ranging from low speeds to high speeds.

Claims (1)

[Scope of Claims] 1. Obtained by reacting a polyvalent metal compound with a copolymer of a styrene monomer, a (meth)acrylic acid ester monomer, and a vinyl monomer having a carboxyl group. , a resin (A) whose glass transition point is 40°C or higher and has a residual carboxyl group, a copolymer of a vinyl monomer having a glycidyl group or a β-methylglycidyl group and another vinyl monomer. a resin (B) in which the content of the vinyl monomer component having a glycidyl group or β-methylglycidyl group is 50% by weight or more and a weight average molecular weight of 50,000 or more; 100 parts by weight of the resin (A); and 1 to 30 parts by weight of a resin (B) as main components. 2. A toner comprising the toner resin composition according to claim 1.