JPS6076752A - Resin composition for toner - Google Patents

Abstract

PURPOSE:To obtain a resin for a superior toner having uniform electrostatic chargeability and a low minimum fixing temp. by using a styrene monomer, a (meth)acrylate monomer and a hemiester compound prepd. from a (meth)acrylic acid deriv. and dicarboxylic acid as the principal components of a copolymer. CONSTITUTION:A copolymer consisting of a hemiester compound represented by formula I , II, III or IV (where each of R1-R6 is H or CH3, each of (m) and (h) is 1-14, each of (n) and (k) is 0-8, each of (j) and (l) is 3-6, and each of X and Y is H, halogen, lower alkyl or alkoxy), a styrene monomer and a (meth)acrylate monomer is blended with a pigment such as carbon black to obtain a toner. This toner can be provided uniformly and stably with negative chargeability, and it has a low fixing temp. and high blocking resistance. The pigment is well dispersed in the toner, and the toner is suitable for high-speed copying.

Description

[Detailed description of the invention] Final F3AI′i ta4 for toner used in electrophotography, etc.
The invention relates to resins, and more specifically to toner resins used in the so-called dry developing method, which is a method for developing electrostatic images.

In the dry development method, the toner is normally charged by friction with a carrier called iron powder or glass beads, which adheres to the electrostatic latent image on the photoreceptor due to electrical attraction, and is then transferred to paper. The image is then fixed using a heat roll or the like to form a permanent visible image.

Generally, a charge control agent such as a gold metal dye is added to a toner in order to adjust the amount of charge during friction, for example, when imparting a negative charge.However, most of these charge control agents are compatible with resins. Due to poor release and purging properties, toner with non-uniform components was often produced.

In order to overcome this drawback, it is known to introduce acrylic acid or methacrylic acid as a total copolymer IiE component into the resin constituting the toner. However, this resin is presumed to be based on its strong intermolecular force, but (mek)acrylic p!
It has the disadvantage that the softening temperature is lower than that of resins that do not contain wo, and the minimum temperature at which the resulting toner can be fixed is relatively high. There is an increasing demand for toner with a low minimum fixing temperature for reasons such as shortening the waiting time.

The present invention takes into consideration the current state of toners and solves the drawbacks of the toner resins, can uniformly and stably impart negative chargeability, has a low minimum fixing temperature, and has excellent blocking resistance and pigment dispersion. These were also developed with the aim of providing toner resins that can provide toners without any problems.

That is, the gist of the present invention is to obtain a styrene monomer, an acrylic acid/methacrylic acid ester monomer, and an acrylic/methacrylic acid-based conductor containing a hydroxyl group by an esterification reaction with a dicarboxylic acid. A resin composition for a toner, characterized in that the main component is a co-M combination having a half-ester compound as a structural unit;
J1 styrene monomer, acrylic acid or methacrylic acid ester monomer, and 3m of the above half ester compound
The main component is a copolymer whose essential constituent units are different types of components.

Specific examples of the styrene monomer used in the present invention include 0-methylstyrene, m-
Methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, pn- Octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-90lustyrene, 31
Examples include 4-dichlorostyrene.

The toner resin needs to have appropriate pulverizability during toner production, and the proportion of steel in the copolymer is 40% by weight or more.

Specific examples of the acrylic acid or methacrylic acid ester monomer used in the present invention include methyl acrylate,
Ethyl acrylate, propyl acrylate, acrylic acid n
-Gutyl, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylate ,
In addition to alkyl esters of acrylic acid or methacrylic acid such as n-octyl acrylate, dodacil methacrylate, and stearyl methacrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, phenyl methacrylate, and dimethylamino methacrylate Ethyl, diethylaminoethyl methacrylate, etc. can be mentioned, and ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, etc. are particularly preferably used.

The above-mentioned styrene monomer and ester monomer of acrylic acid or methacrylic acid are usually contained in the above copolymer.
Contains about 99.5% by weight.

The half-ester compound moiety and carboxyl group-containing compound used in the present invention are, for example, aliphatic dicarboxylic acids such as malonic acid, succinic acid, and glucuric acid, or aromatic dicarboxylic acids such as phthalic acid, and acrylic acid containing a hydroxyl group. Alternatively, it can be obtained by an esterification reaction with a methacrylic acid derivative. The dicarboxylic acid may have a hydrogen atom substituted with a halogen group element, a lower alkyl group, an alkoxy group, etc., or may be an acid anhydride.

The hydroxyl group-containing acrylic acid or methacrylic acid derivative may be one in which 1 or 2 moles or more of an alkylene oxide such as ethylene oxide or propylene oxide is added to acrylic acid or methacrylic acid, or acrylic acid or methacrylic acid. It may also be a hydroxyalkyl ester obtained by subjecting a dihydric alcohol such as propylene glycol to a dihydric alcohol reaction.

The l1fJ half-ester compound is represented by the following general formulas (11 to (4)), for example.

(l　R　R+ CH,=CR.

10 (Rs, Rs H or VicH,, m 1-14.n represents 0 to 8.) (Rs, R4 digits H or CH,, h represents 1 to 14. X represents H
.

Represents a halogen group element, lower alkyl group, or alkoxy group. ) (Represents 3111°CH,=C.) fi R1 1v (R, #-iH and CH3, t represents 3-6.Y and H, a norogen group element, a lower alkyl group, or an alkoxy group.) and Preferred specific examples of half-ester compounds include mono(meth)acryloyloxyethyl succinate, mono(meth)acryloyloxypropyl succinate, mono(meth)acryloyloxyethyl glutarate, and mono(meth)acryloyl phthalate. Oxyethyl ester, heptacuric acid mono(meth)acryloyloxypropyl ester, etc. are used.

The content of these half-ester compounds in the copolymer is:
If the amount is too small, low-temperature fixing properties, negative chargeability, pigment dispersibility, etc. will not be sufficiently expressed, and if it is too large, the toner loading fl amount will be easily affected by temperature, resulting in copolymerization of ester single F and half-ester compounds. The method for producing the coalescence is not specified in any way; for example, known methods such as suspension polymerization, solution polymerization, emulsion polymerization, and block polymerization are employed, but suspension polymerization and solution polymerization are particularly suitable. is often used.

Vinyl acetate, vinyl propionate, vinyl chloride, ethylene, etc. may be introduced into the toner resin of the present invention as a copolymer component within a range that can achieve the object of the present invention, and the polymer of the above monomers may be incorporated into the resin for toner of the present invention. There is no problem even if it is blended.

Further, polyester resin or epoxy resin may be mixed.

The toner resin of the present invention has the above-mentioned structure, and contains as a main component a copolymer having the above-mentioned unique half-ester compound as a constituent unit along with the entire styrene monomer, acrylic acid or methacrylic acid ester spinning wheel. Therefore, conventional P containing acrylic acid or methacrylic acid as a copolymerization component
Compared to electrically charged resins, it has a practically extremely useful effect of having a lower fixable Iυ temperature, and also has blocking resistance and pigment dispersibility that are equivalent to or better than conventional products as toner resins.

Examples of the present invention are shown below. An anonymous number or simply "parts" refers to parts by weight (tcft).

Example 1 21 (!, (Put toluene 4002 in a rubble flask, replace the air with nitrogen gas, and then heat the system to the boiling point of toluene and add styrene 7501i while stirring.
', 200 y of n-butyl acrylate, 50 y of monoacryloyloxyethyl succinate, and 10 y of benzoyl peroxide as a polymerization initiator were dissolved in a mixture of 2.5 y.
Uranami polymerization was carried out while dropping the solution over time.

After the dropwise addition of the mixture was completed, the mixture was further stirred at the boiling point temperature of toluene for 1 hour, and then the temperature of the system was further increased to 18 °C.
Toluene was removed from the solvent under reduced pressure while gradually raising the temperature to 0° C. to obtain a styrene-n-butyl acrylate-monoacryloyloxyethyl succinate copolymer. This copolymer resin was cooled and pulverized to obtain flaky resin A of the present invention. The softening point of this resin was measured by the ring and ball method and was found to be about 104°C.

100 parts of resin A and carbon black (dia black S
H: Mitsubishi Kasei! ! After cooling, the toner was melt-blended with part S, cooled, coarsely pulverized, and then finely pulverized with a jet mill to prepare a toner having an average particle size of about 13 to 15 microns, which was used as a sample.

This toner was left at a temperature of 60° C. for 2 hours, and the blocking resistance was evaluated based on the presence or absence of coalescence of particles.

Further, a developer was prepared by mixing 4 parts of this toner with 96 parts of iron powder carrier having an average particle size of about 50 to 80 μm to 90 μm, and after shaking and stirring according to a conventional method, a glow-off powder charge amount measuring device was used.

Furthermore, after developing the electrostatic charge image formed by ordinary electrophotography using the above developer, the toner image is transferred onto transfer paper and heated at a temperature of 90 to 140°C using a heated roller whose surface is coated with silicone resin. The low temperature at which fixing was possible was investigated.

On the other hand, the toner was observed using an optical microscope to observe the dispersion state of carbon black.

The above results are shown in Table 1.

From these results, it is clear that when resin A of the present invention was used, a toner with excellent fixing properties at low temperatures, good anti-blocking properties, excellent charging properties, and good dispersibility of carbon black was obtained.

1 Example 2 In Example I, 7-talic acid monoacryloyloxyethyl ester was modified to succinic acid monoacryloyloxyethyl ester, and 1- m Ill M I + 1- Δ
I'm m al I L F'l M+ If l
'-r -k fi llrl shoulder (-Resin B was obtained.The softening point of this resin by the ring relief method was about 10
The temperature was 5°C.

Next, a toner was prepared in the same manner as in Example 1 except that Resin B was used, and various physical properties were measured, and the results were as shown in Table 1 of Vi.

Examples 3 to 6 Fi Example 1 except for using the monomer composition shown in Table 1
Each of the resins C, D, E, and F was obtained in the same manner as in Example 1, and a toner was prepared in the same manner as in Example 1. The physical properties of the toner were examined, and the results were as shown in Table 1.

The weight average molecular weight of Resin C was approximately 40,000.

Comparative Examples 1 to 5 Resins G, H, I, and J were obtained in the same manner as in Example 1 except that monomers having the compositions shown in Table 1 were used, and toner resins were obtained in the same manner as in Example 1 (!- The results were as shown in Table 1 of Fi.The weight average molecular weight of Resin G was about 40.000.

As is clear from Table 1, Resin G of Comparative Example 1 has low-temperature fixing properties, but has poor blocking resistance, low charge amount, and poor dispersibility of carbon black.

Resins H and I have good anti-blocking properties, but have a high minimum fixable temperature and are not suitable for toner KVi, which requires low-temperature fixing.

Resin J has poor blocking resistance.

Vγ1 Agency et al.

Claims (1)

[Scope of Claims] L A styrenic monomer, an acrylic acid or meccrylic acid ester monomer, and a half-structure obtained by an esterification reaction between an acrylic acid or meccrylic acid derivative containing a hydroxyl group and a dicarboxylic acid. A resin composition for a toner, characterized in that the main component is a copolymer having an ester compound as an acceptance unit. 2. The resin composition according to item 1, wherein the half-ester compound is represented by the general formula %. 3. The half-ester compound has the general formula %, and represents a lower alkyl group or an alkoxy group. ) The resin composition 0 of item 1 is represented by 4, and the half ester compound is represented by the general formula % formula %) 1f! 5. The resin composition according to item 2, wherein the half-ester compound is monoacryloyloxyethyl cono-phosphate or monomethacryloyloxyethyl succinate. 6. The resin composition according to item 3, wherein the half-ester compound is monoacryloyloxyethyl fucuric acid ester. 7. The content of half ester compound in the copolymer is 0°5
The wood-oh composition according to any one of Items 1 to 6, which has a content of ~20% by weight. 8. The tree according to item 1, which is any of items 1 to 7, wherein the content of styrenic monomer in the copolymer is 30 or more molecules.
No I is a thing.