JPH0720654A - Resin composition for cross-linkable toner and cross-linkable toner - Google Patents

Abstract

PURPOSE:To provide a resin compsn. for a cross-linkable toner and a cross- linkable toner fixable at a relatively low temp. in a wide temp. range and excellent in fixability, anti-offsetting property and blocking resistance in a well-balanced state. CONSTITUTION:Fine powder of a copolymer contg. a styrene monomer and a vinyl monomer having an org. functional group such as glycidyl, beta- methylglycidyl, carboxyl, carboxylic anhydride, amino or hydroxyl as constituent components and having 3,000-150,000 wt. average mol.wt. is prepd. and fine powder of a cross-linkable compd. which reacts with the org. functional compd. under heating is added to the prepd. fine powder. They are uniformly mixed and dispersed in the form of fine powder to obtain the objective resin compsn. for a cross-linkable toner. The objective cross-linkable toner is obtd. using the fine powdery resin compsn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a crosslinkable toner used for developing an electrostatic image in electrophotography and the like, and a crosslinkable toner using the resin composition.

[0002]

2. Description of the Related Art In electrophotography, a dry developing system is often used as a system for developing an electrostatic image. In this dry developing method, a triboelectric chargeable fine powder developer called a toner in which a binder resin contains a colorant such as carbon black dispersed therein is used.

Usually, toner charged by friction adheres to an electrostatic latent image on a photoconductor by an electric attraction to form a toner image, and then this toner image is transferred onto a sheet,
It is fixed by a hot pressing roller having a releasing property for the toner.

Such toner is mainly composed of fixability (toner firmly adheres to a sheet at a low temperature and has a wide fixing temperature range), offset resistance (toner adheres to a heat pressure roller, and this is the sheet. It is required to have various performances such as re-transferring to the toner to prevent the image from being stained) and blocking resistance (the toner particles do not aggregate during storage of the toner).

Conventionally, as a toner of this type, for example, in JP-A-55-12903, a copolymer containing a vinyl-based monomer having a glycidyl group or a β-methylglycidyl group and another vinyl-based monomer as constituent components is used. A toner has been proposed in which a crosslinkable compound that reacts with a glycidyl group or a β-methylglycidyl group is mixed with the coalesced product, both are melt-kneaded to crosslink the copolymer, and this is finely pulverized.

[0006] Further, for example, JP-A-58-173752
The publication discloses a toner containing a polymer obtained by crosslinking a polymer containing a vinyl-based monomer having a carboxyl group as a constituent with a specific diamine compound.

However, these conventional toners are relatively good in the above-mentioned various performances, but the melting start temperature of the resin after crosslinking rises, and it is required in response to the recent increase in speed of electronic copying machines. It has not reached the point where the performance is fully satisfied.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and an object thereof is to provide fixability, offset resistance and blocking resistance in a relatively low temperature and a wide fixing temperature range. (EN) It is intended to provide a resin composition for a crosslinkable toner and a crosslinkable toner which are excellent in balance in any of the above properties.

[0009]

The resin composition for a crosslinkable toner according to the present invention comprises a vinyl-based monomer having an organic functional group and a styrene-based monomer as constituent components, and has a weight average molecular weight of 3,000 to 3,000. A crosslinkable compound that reacts with the above-mentioned organic functional group upon heating is post-added to the copolymer of 150,000 (this post-addition is sometimes called external addition).

Examples of the vinyl monomer having an organic functional group include vinyl monomers having a glycidyl group or β-methylglycidyl group, vinyl monomers having a carboxyl group or an acid anhydride thereof, and amino groups. A vinyl-based monomer having, a vinyl-based monomer having a hydroxyl group, or the like is used.

Examples of the vinyl monomer having a glycidyl group or a β-methylglycidyl group include, for example, glycidyl acrylate (meth), β-methylglycidyl (meth) acrylate, allyl glycidyl ether, and allyl β.
-Methyl glycidyl ether and the like.

Examples of the vinyl monomer having a carboxyl group or an acid anhydride thereof include (meth) acrylic acid, α-methylacrylic acid, crotonic acid,
Unsaturated monocarboxylic acids such as isocrotonic acid and β-methylcrotonic acid; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid; succinic acid mono (meth) acryloyloxyethyl ester, phthalic acid mono (meth ) Unsaturated dicarboxylic acid monoesters such as acryloyloxyethyl ester; acid anhydrides such as succinic anhydride, maleic anhydride, and phthalic anhydride.

Examples of the vinyl monomer having an amino group include (meth) acrylamide and the like, and examples of the vinyl monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate and (meth ) Hydroxypropyl acrylate and the like can be mentioned.

When the content of any of these vinyl-based monomer components having an organic functional group is small, the offset resistance of the resulting crosslinkable toner is lowered, and when the content is high, the fixation of the obtained crosslinkable toner is fixed. Therefore, 5 to 60% by weight based on the total monomer components is preferable because
It is more preferably 10 to 30% by weight.

In addition to the above, other vinyl-based monomers may be contained, if desired. However,
The other vinyl-based monomer must be one that does not react with the organic functional group of the vinyl-based monomer having the above organic functional group.

As the other vinyl-based monomer,
For example, (meth) methyl acrylate, (meth) ethyl acrylate, (meth) propyl acrylate, (meth) n-butyl acrylate, (meth) isobutyl acrylate,
(Meth) acrylic acid esters such as (meth) acrylic acid n-octyl and (meth) acrylic acid 2-ethylhexyl;
Vinyl esters such as vinyl acetate and vinyl propionate,
Examples thereof include nitrogen-containing monomers such as (meth) acrylonitrile and vinylpyrrolidone.

Examples of the styrene-based monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, 2,4.
-Dimethylstyrene, p-phenylstyrene, p-chlorostyrene and the like can be mentioned.

When the weight average molecular weight of the copolymer used in the invention of claim 1 is small, the offset resistance of the obtained crosslinkable toner is lowered, and when it is large, the fixability of the obtained crosslinkable toner is lowered. Therefore, 3000-
Limited to 150,000, preferably 5000-500
00. The weight average molecular weight of the copolymer is
It is a value measured by gel permeation chromatography (GPC).

As the method for producing the above copolymer, for example, a vinyl monomer having an organic functional group and a styrene monomer are prepared by a conventionally known method such as solution polymerization, suspension polymerization, emulsion polymerization or bulk polymerization. Examples thereof include a method of copolymerizing.

Further, when the melting start temperature of the resin composition for crosslinkable toner according to claim 1 measured by a flow tester becomes higher, the fixability of the obtained crosslinkable toner decreases, so that it is preferably 120 ° C. or less. , Differential scanning calorimeter (D
If the glass transition temperature measured by SC) becomes low, the blocking resistance of the obtained crosslinkable toner decreases,
It is preferably 50 ° C. or higher.

The resin composition for a crosslinkable toner according to the first aspect of the invention is obtained by post-adding a cross-linkable compound to the above-mentioned copolymer (this post-addition is sometimes called external addition). In the case of the post-addition, when a vinyl monomer having a glycidyl group or a β-methylglycidyl group as an organic functional group and a copolymer containing a styrene monomer as a constituent are used, the glycidyl group or β- A crosslinkable compound that reacts with the methylglycidyl group when heated is used.

Examples of the crosslinkable compound that reacts with the glycidyl group or β-methylglycidyl group when heated include, for example, succinic acid, adipic acid, sebacic acid and dodecane 2
Acid, hexadecane diacid, phthalic acid, phthalic anhydride, trimellitic anhydride, and other polybasic acids; polyamino amines such as diaminodiphenylmethane, diaminodiphenylsulfone, diaminobenzene; p-aminobenzoic acid, aspartic acid, glutamic acid, etc. Aminocarboxylic acids; polymers containing these in the structure, and the like.

Further, a vinyl monomer having a carboxyl group as an organic functional group or an acid anhydride thereof,
When a copolymer containing a styrene-based monomer as a constituent is used, a crosslinking compound that reacts with the carboxyl group or its acid anhydride upon heating is added later.

Examples of the crosslinkable compound which reacts with the above-mentioned carboxyl group or its acid anhydride upon heating include polyfunctional amines such as diaminodiphenylmethane; Epoxy compounds; polyfunctional isocyanate compounds such as ε-caprolactam block isophorone diisocyanate, cresol block xylylene diisocyanate, and phenol block tolylene diisocyanate; polymers containing these in the structure.

When a copolymer containing a vinyl-based monomer having an amino group as an organic functional group and a styrene-based monomer is used as a constituent, a crosslinking compound that reacts with the amino group when heated is added later. To be done. Examples of the crosslinkable compound that reacts with such an amino group when heated include the above-mentioned polybasic acids, polyfunctional epoxy compounds, and polymers containing these in the structure.

When a copolymer containing a vinyl-based monomer having a hydroxyl group as an organic functional group and a styrene-based monomer is used, a crosslinkable compound that reacts with the hydroxyl group after heating is added later. To be done. Examples of the crosslinkable compound that reacts with such a hydroxyl group upon heating include the above-mentioned polybasic acids, polyfunctional isocyanate compounds, and polymers containing these in the structure.

When the post-addition amount of these cross-linking compounds decreases, the offset resistance of the cross-linking toner obtained decreases, and when the post-addition amount of the cross-linking toner increases, the fixing strength of the cross-linking toner decreases. 0.0 parts by weight
1 to 5 parts by weight is preferable.

The resin composition for a crosslinkable toner according to the first aspect of the invention is produced, for example, by the following method. First, a colorant such as carbon black; other charge control agents such as nigrosine and spirone black; and conventional additives such as release agents such as polyethylene wax and polypropylene wax are mixed with the above-mentioned copolymer, if necessary. ,this,
Using a roll mill, kneader, extruder, etc., generally 10
Melt kneading at 0-200 ° C, fine pulverization and classification,
A fine powder of a resin composition having a particle size of about 5 to 20 μm is used.

Then, to the fine powder of the resin composition, fine powder of the crosslinkable compound previously finely pulverized in a mortar or the like is post-added so as to have a particle size of the fine powder of the resin composition or less, and this is added. Is uniformly mixed and dispersed in a fine powder form at a low temperature of about room temperature with a dry powder surface reforming device or a ribbon blender, and the fine powder of the crosslinkable compound is attached to the surface of the fine powder of the resin composition. . Thus, the resin composition for crosslinkable toner is obtained.

The crosslinkable toner according to the second aspect of the invention is obtained by using the resin composition for crosslinkable toner according to the first aspect. To produce the crosslinkable toner, for example, a fine powder of the resin composition for the crosslinkable toner, a carrier such as iron powder or glass beads, and, if necessary, a fluidity improver such as hydrophobic silica. Etc. are added and uniformly mixed and dispersed in the form of fine powder. In this way, a crosslinkable toner is obtained.

[0031]

The copolymer containing a vinyl-based monomer having an organic functional group and a styrene-based monomer as constituents and having a weight average molecular weight of 3,000 to 150,000 has a cross-linking compound which reacts with the above organic functional group after heating. Resin composition for crosslinkable toner, which is added (the invention according to claim 1)
In the crosslinkable toner using (1), the crosslinkable compound is mixed and dispersed by the post-addition method, so that the copolymer has not yet been crosslinked before use.

The crosslinkable toner obtained by using the above-mentioned resin composition for crosslinkable toner is easily melted by heating at the time of fixing using an electronic copying machine or the like, and exhibits excellent fixability. Then, by heating thereafter, the copolymer and the crosslinkable compound react with each other to cause crosslinking in the copolymer, thereby exhibiting excellent offset resistance.

As described above, the reason why the excellent anti-offset property is exhibited is that the organic functional group of the copolymer and the crosslinkable compound are present at the interface between the toner and the hot pressing roller when the toner is fixed using an electronic copying machine or the like. It is inferred that and react instantaneously, the cohesive force in the vicinity of the interface of the toner remarkably increases, and the adhesion to the hot pressing roller is prevented.

[0034]

EXAMPLES Examples and comparative examples of the present invention will be shown below. Example 1 Glycidyl methacrylate and styrene were reacted in toluene in the presence of benzoyl peroxide, and after the reaction, toluene was distilled off to obtain a copolymer. The obtained copolymer had a glycidyl methacrylate component content of 30% by weight and a styrene component content of 7%.
It was composed of 0% by weight, and its weight average molecular weight was 10,000. The weight average molecular weight was measured by GPC.

To 90 parts by weight of the obtained copolymer, 6 parts by weight of carbon black (Dia Black SH: manufactured by Mitsubishi Kasei Co.) and polyethylene wax (Sunwax 131P:
2 parts by weight (manufactured by Sanyo Kasei Co., Ltd.) are roll-kneaded at 200 ° C. for 30 minutes, cooled, coarsely pulverized, and then finely pulverized by a jet mill to obtain fine powder of a resin composition before addition having an average particle diameter of 10 to 15 μm. It was The melting start temperature of the obtained fine powder of the resin composition after addition by a flow tester is 104 ° C.
The glass transition temperature by C was 56 ° C.

Using a dry powder surface modification device, 100 parts by weight of the fine powder of the resin composition after addition obtained, 2 parts by weight of fine powder of sebacic acid (average particle size 3 μm) and fine powder of hydrophobic silica were used. (R-972: manufactured by Nippon Aerosil Co., Ltd.) 0.3 part by weight was post-added to obtain a fine powder of the resin composition for a crosslinkable toner. The fine powder of the resin composition for a crosslinkable toner thus obtained,
There was no coalescence of particles and the blocking resistance was good.

Next, 4 parts by weight of the fine powder of the resin composition for a crosslinkable toner thus obtained was mixed with 96 parts by weight of an iron powder carrier having an average particle size of about 50 to 80 μm to obtain a crosslinkable toner. The obtained crosslinkable toner was subjected to a copy test using a high-speed copying machine while changing the temperature of the hot pressing roller. As a result, offset was not caused at a relatively low temperature of 160 to 200 ° C. and a wide range of temperatures. The image obtained was good with no fog.

The melting start temperature is measured by the above flow tester by the Koka type flow tester (CFT-500).
0: Orifice (1mmΦ × 1m) using Shimadzu
m) was attached and precisely weighed in a cylinder at a temperature rising start temperature (80 ° C.), and then fine powder of the resin composition before addition 1.
00g is filled, a plunger is inserted, and pre-heated for about 5 minutes so that the fine powder becomes a uniform temperature under the condition of being lightly pressed, and after pre-heating, a load of 20 kg / cm ² is applied, and the speed is constant (6 ° C).
/ Min) and the cylinder was heated to measure.

Example 2 Acrylic acid, n-butyl acrylate and styrene were reacted in toluene in the presence of benzoyl peroxide, and after the reaction, toluene was distilled off to obtain a copolymer. The obtained copolymer consisted of 20% by weight of acrylic acid component, 20% by weight of n-butyl acrylate component and 60% by weight of styrene component, and had a weight average molecular weight of 10,000.

To 90 parts by weight of the obtained copolymer, 6 parts by weight of carbon black (Diablack SH: manufactured by Mitsubishi Kasei Co.) and polyethylene wax (Sunwax 131P:
2 parts by weight (manufactured by Sanyo Kasei Co., Ltd.) are roll-kneaded at 200 ° C. for 30 minutes, cooled, coarsely pulverized, further finely pulverized by a jet mill, and fine powder of a resin composition before addition having an average particle diameter of 10 to 15 μm. Got The melting start temperature of the obtained fine powder of the resin composition after addition by a flow tester was 100 ° C., and the glass transition temperature by DSC was 54 ° C.

Using a dry powder surface modification device, 100 parts by weight of the fine powder of the resin composition thus obtained before addition, 2 parts by weight of triglycidyl isocyanurate fine powder (average particle size 3 μm) and hydrophobic silica were used. 0.3 part by weight of fine powder (R-972: manufactured by Nippon Aerosil Co., Ltd.) was post-added to obtain fine powder of the resin composition for crosslinkable toner. The obtained fine powder of the resin composition for a crosslinkable toner had no coalescence of particles and had good blocking resistance.

Next, 4 parts by weight of the fine powder of the resin composition for a crosslinkable toner thus obtained was mixed with 96 parts by weight of an iron powder carrier having an average particle size of about 50 to 80 μm to obtain a crosslinkable toner. The obtained crosslinkable toner was subjected to a copy test using a high-speed copying machine while changing the temperature of the hot pressing roller. As a result, offset was not caused at a relatively low temperature of 160 to 200 ° C. and a wide range of temperatures. The image obtained was good with no fog.

Example 3 Acrylamide, n-butyl acrylate and styrene were reacted in toluene in the presence of benzoyl peroxide, and after the reaction, toluene was distilled off to obtain a copolymer. The obtained copolymer consisted of 20% by weight of acrylamide component, 20% by weight of n-butyl acrylate component and 60% by weight of styrene component, and had a weight average molecular weight of 10,000.

To 90 parts by weight of the obtained copolymer, 6 parts by weight of carbon black (Dia Black SH: manufactured by Mitsubishi Kasei) and 2 parts by weight of polyethylene wax (Sunwax 131P: manufactured by Sanyo Chemical Co., Ltd.) were added at 200 ° C. Roll-kneading for 30 minutes, cooling, coarse pulverization, and fine pulverization with a jet mill to obtain fine powder of the resin composition before post-addition having an average particle size of 10 to 15 μm. The melting start temperature of the obtained fine powder of the resin composition after addition by a flow tester was 108 ° C., and the glass transition temperature by DSC was 57 ° C.

Using a dry powder surface modification device, 100 parts by weight of the fine powder of the resin composition obtained after addition and 2 parts by weight of fine powder of sebacic acid (average particle size 3 μm) and fine powder of hydrophobic silica were added. (R-972: manufactured by Nippon Aerosil Co., Ltd.) 0.3 part by weight was post-added to obtain a fine powder of the resin composition for a crosslinkable toner. The fine powder of the resin composition for a crosslinkable toner thus obtained,
There was no coalescence of particles and the blocking resistance was good.

Next, 4 parts by weight of the fine powder of the resin composition for a crosslinkable toner thus obtained was mixed with 96 parts by weight of an iron powder carrier having an average particle diameter of about 50 to 80 μm to obtain a crosslinkable toner. The obtained crosslinkable toner was subjected to a copy test using a high-speed copying machine while changing the temperature of the hot pressing roller. As a result, offset was not caused at a relatively low temperature of 160 to 200 ° C. and a wide range of temperatures. The image obtained was good with no fog.

COMPARATIVE EXAMPLE 1 Copolymer 90 without adding sebacic acid fine powder afterwards
Fine powder of a resin composition for toner was obtained in the same manner as in Example 1 except that 6 parts by weight of carbon black and 2 parts by weight of polyethylene wax were mixed with 2 parts by weight of fine powder of sebacic acid by pre-addition. . The copolymer in the obtained resin composition for toner was already crosslinked, and the melting start temperature by the flow tester was 134 ° C., which was higher than that in Example 1.

Next, using the obtained fine powder of the resin composition for a toner, a toner was obtained in the same manner as in Example 1, and a copy test was conducted in the same manner as in Example 1 using the obtained toner. It was As a result, the temperature range showing good fixability without causing offset was 200 to 220 ° C., which was a higher temperature and a narrower range of temperature than in Example 1. The obtained image was relatively good.

Comparative Example 2 2 parts by weight of triglycidyl isocyanurate fine powder was added to 90 parts by weight of copolymer, together with 6 parts by weight of carbon black and 2 parts by weight of polyethylene wax, without post-adding fine powder of triglycidyl isocyanurate. Fine powder of a resin composition for toner was obtained in the same manner as in Example 2 except that the powder was mixed by pre-addition. The copolymer in the obtained resin composition for toner was already crosslinked, and the melting start temperature by the flow tester was 133 ° C., which was higher than that in Example 2.

Next, using the obtained fine powder of the resin composition for toner, a toner was obtained in the same manner as in Example 2, and a copy test was conducted in the same manner as in Example 2 using the obtained toner. It was As a result, the temperature range showing good fixability without causing offset was 200 to 220 ° C., which was a higher temperature and a narrower range of temperature than in Example 1. The obtained image was relatively good.

COMPARATIVE EXAMPLE 3 Copolymer 90 was prepared without the addition of fine powder of sebacic acid.
Fine powder of a resin composition for toner was obtained in the same manner as in Example 3 except that 6 parts by weight of carbon black and 2 parts by weight of polyethylene wax were mixed with 2 parts by weight of fine powder of sebacic acid by pre-addition. . The copolymer in the obtained resin composition for toner was already crosslinked, and the melting start temperature by the flow tester was 140 ° C., which was higher than that in Example 3.

Next, using the obtained fine powder of the resin composition for a toner, a toner was obtained in the same manner as in Example 3, and a copy test was conducted in the same manner as in Example 3 using the obtained toner. It was As a result, the temperature range showing good fixability without causing offset was 200 to 220 ° C., which was a higher temperature and a narrower range of temperature than in Example 3. The obtained image was relatively good.

Comparative Example 4 A fine powder of a resin composition for toner was obtained in the same manner as in Example 1 except that sebacic acid was not added at all. The melting start temperature of the obtained fine powder of the resin composition for toner obtained by a flow tester was 103 ° C., which was about the same as in Example 1.

Next, using the obtained fine powder of the resin composition for a toner, a toner was obtained in the same manner as in Example 1, and a copy test was conducted in the same manner as in Example 1 using the obtained toner. It was As a result, the temperature range showing good fixability without causing offset was 160 to 170 ° C., which was a narrower range of temperature than in Example 1. The obtained image was relatively good.

Comparative Example 5 A fine powder of a toner resin composition was obtained in the same manner as in Example 2 except that triglycidyl isocyanurate was not added at all. The melting start temperature of the obtained fine powder of the resin composition for toner by a flow tester was 101 ° C., which was about the same as in Example 2.

Next, using the obtained fine powder of the resin composition for toner, a toner was obtained in the same manner as in Example 2, and a copy test was conducted in the same manner as in Example 2 using the obtained toner. It was As a result, the temperature range showing good fixability without causing offset was 160 to 170 ° C., which was a narrower range of temperature than in Example 2. The obtained image was relatively good.

Comparative Example 6 A fine powder of a resin composition for toner was obtained in the same manner as in Example 3 except that sebacic acid was not added at all. The melting start temperature of the resulting fine powder of the resin composition for toner obtained by a flow tester was 107 ° C., which was about the same as in Example 3.

Next, using the obtained fine powder of the resin composition for a toner, a toner was obtained in the same manner as in Example 3, and a copy test was conducted in the same manner as in Example 3 using the obtained toner. It was As a result, the temperature range showing good fixability without causing offset was 160 to 170 ° C., which was a narrower range of temperature than in Example 3. The obtained image was relatively good.

[0059]

As described above, the resin composition for crosslinkable toner of the present invention contains a vinyl-based monomer having an organic functional group and a styrene-based monomer as constituent components, and has a weight average molecular weight of 3,000 to 150,000. A crosslinkable compound obtained by post-adding a crosslinkable compound that reacts with the above organic functional group upon heating to a polymer and obtained by using the resin composition for crosslinkable toner has a relatively low temperature in a wide fixing temperature range. Excellent balance, excellent performance in fixing property, offset resistance and blocking resistance. Further, the charged state of the toner particles is stable, and the obtained image is clear without fogging.

Therefore, the resin composition for a crosslinkable toner and the crosslinkable toner of the present invention can be suitably used as a toner for a heating roller fixing type electrophotographic copying machine from low speed to high speed.

Claims (2)

[Claims] 1. A cross-linking compound which reacts with the above organic functional group when heated to a copolymer containing a vinyl monomer having an organic functional group and a styrene monomer as constituents and having a weight average molecular weight of 3,000 to 150,000. A resin composition for a crosslinkable toner, characterized in that 2. A crosslinkable toner obtained by using the resin composition for crosslinkable toner according to claim 1.