JPH02264966A - Electrophotographic color toner - Google Patents

Abstract

PURPOSE:To enhance light resistance of a color toner and to stabilize an image by incorporating a specified compound. CONSTITUTION:The color toner contains the binder resin, such as polyester, a colorant, and the compound represented by formula I in which R<1> is H or hydroxy or lower alkyl; R<2> is H, hydroxy, or carboxy; R<3> is hydroxy, lower alkoxy, or halogen; and R<4> is H or sulfonic acid group. As the compound of formula I, the compound of formula II and the like can be used and an electrostatic charge controller and the like can be added to the toner, when needed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color toner for electrophotography, and more particularly to a color toner for electrophotography containing a specific compound.

(Prior art) Electrophotography is described in U.S. Patent No. 22971st/No.
Publication No. 72-23910 and Special Publication Sho tI3-. 2f7
As disclosed in various publications such as No. 4'ff, generally, an electrical latent image of electrostatic charge is formed on a photoreceptor containing a photoconductive material by various means, and then the latent image is converted into a powder image using toner. After developing and transferring the powder image to paper or the like as necessary, it is fixed by heating, pressure, or solvent vapor.In recent years, it is also possible to improve the electromagnetic density of originals by exposing them to separated light. A method of copying has been put into practical use, in which the images are formed and developed with color toners of each color to obtain a colored copy image, or the copy images of each color are superimposed to obtain a full-color copy image. Color toners such as yellow, magenta, and cyan are produced by dispersing dyes and/or pigments of various colors in a binder resin.

The toner used is particles made by dispersing coloring agents such as dyes and pigments in a resin such as polyester and finely pulverized to about 30 μm. It is used by mixing with a carrier material such as.

(Problems to be Solved by the Invention) However, in conventional color toners, the dyes and pigments used as colorants do not have sufficient light resistance, and if the copy sample is left undisturbed, the color may change, and each color Problems such as a decrease in color reproducibility have arisen due to changes in color balance due to discoloration of the toner.

(Means for Solving the Problems) As a result of intensive studies to solve these problems, the present inventors have found an excellent method that solves the above problems by incorporating a compound represented by a specific structural formula. The present invention was achieved by learning that a toner can be obtained.

That is, the gist of the present invention resides in a color toner for electrophotography characterized by containing a binder resin, a colorant, and a compound represented by the following general formula (1).

(In the formula, R1 represents a hydrogen atom, a hydroxyl group, or a lower alkoxy group, R2 represents a hydrogen atom, a hydroxyl group, or a carboxyl group, R3 represents a hydroxyl group, a lower alkoxy group, or a halogen atom, and R4 represents a hydrogen atom or a sulfonic acid group. ) (Function) The present invention will be described in detail below.

The binder resin for toner can be selected from a wide range including known ones, but colorless and transparent ones are preferable, such as polystyrene, chloropolystyrene,
Poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-
butadiene copolymer, styrene-vinyl chloride copolymer,
Styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer) styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-
Methacrylic acid ester copolymers (styrene-methyl methacrylate copolymer, stene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.), styrene-α-chlor Styrenic resins (unipolymers or copolymers containing styrene or styrene substitutes) such as methyl acrylate copolymer and styrene-acrylonitrile-acrylic ester copolymer, vinyl chloride resin, rosin-modified maleic acid resin, phenol resins, epoxy resins, saturated or unsaturated polyester resins, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resins, polyurethane resins, silicone resins, ketone resins, ethylene-ethyl acrylate copolymers, xylene resins, and polyvinyl butyral resins. Particularly preferred resins for use in the present invention include styrene resins, saturated or unsaturated polyester resins, and epoxy resins. Moreover, the above resins are not limited to being used alone, but can also be used in combination of two or more.

Furthermore, as a colorant, any known dye or pigment used in color toners can be used without any particular restrictions, and it goes without saying that the above colorants are not limited to being used alone, but can also be used in combination of two or more. .

The amount of colorant added to the toner is 0.00 parts by weight per 100 parts by weight of the binder resin. /~30@fi part is desirable, especially O
, S~/θ heavy view area is desirable. If the amount added is too small, the coloring effect will be poor, and if it is too large, the fixing properties will be poor, which is an undesirable tendency.

The charge control of the toner may be performed using the binder resin or dye/pigment itself, but if necessary, a charge control agent that does not cause problems in color reproduction may be used in combination. As the positive charge control agent, a basic/electron-donating substance such as a double ammonium salt may be used, and as the negative charge control agent, an acidic/electron-withdrawing substance such as metal chelates or metal-containing dyes may be appropriately selected and used. good.

The amount of the charge control agent to be added should be determined after considering conditions such as the chargeability of the binder resin, the manufacturing method including the amount and dispersion method of the colorant, and the chargeability of other additives. On the other hand, o and i to 10 parts by weight are suitable.

In addition, inorganic particles such as metal oxides or inorganic substances surface-treated with the above-mentioned organic substances may be used.

These charge control agents may be used by being mixed into the binder resin, or may be used in the form of being attached to the surface of the toner particles.

Furthermore, the electrical properties of the toner can be controlled by adding solid electrolytes, polymer electrolytes, charge transfer complexes, conductors such as metal oxides such as tin oxide, semiconductors, ferroelectric materials, magnetic materials, etc. 0 In addition, it is also possible to add various auxiliary agents such as plasticizers and release agents to the toner for the purpose of adjusting thermal properties, physical properties, etc. The appropriate addition amount is o, i to 10 parts by weight.

Furthermore, toner particles include TiO□, Al2O3, and SiO2.
By adding fine powders such as these and coating the surfaces of toner particles, it is possible to improve the fluidity and agglomeration resistance of the toner. The amount added is preferably 0.1 to 70 parts by weight per 100 parts by weight of toner particles.

Various conventional toner manufacturing methods can be applied to the toner manufacturing method of the present invention. For example, the following example can be given as a boat fishing manufacturing method.

First, the resin and colorant (additives such as a charge control agent may be added depending on the case) are mixed in a ball mill, a V-type mixer,
Uniformly disperse using an S-type mixer, Henschel mixer, etc.

Next, the dispersion is melt-kneaded using a dual-arm kneader, 1 pressure kneader, extruder roll mill, or the like. The mixed material is pulverized using a pulverizer such as a hammer mill, cutter mill, shet mill, or ball mill, and the resulting powder is further classified using an air classifier or the like.

The resulting color toner can be mixed with a carrier and used as a developer for electrophotographic copying. As the carrier, it is preferable to use a magnetic material such as a known iron powder carrier or a ferrite carrier, or a carrier coated on the surface thereof in an amount of IO parts to /θθ parts with respect to 1 part of the toner.

In the compound of general formula (1) contained in the electrophotographic color toner of the present invention, R' represents a hydrogen atom, a hydroxyl group, or a lower alkoxy group such as a methoxy group or an ethoxy group, and R2 represents a hydrogen atom, a hydroxyl group, or a carboxyl group. R3 represents a hydroxyl group, a lower alkoxy group such as methoxy group or ethoxy, or a halogen, and R4
represents a hydrogen atom or a sulfonic acid group. Specific examples of the compound are shown below.However, among the compounds, the compounds that can be used in the present invention are not limited to these, and the compound represented by the general formula (I) is You may use a mixture of two or more species.

H Yellow By incorporating the compound represented by the general formula (I) into color toners of various colors such as magenta and cyan, the light resistance of the color toners is significantly improved.

The amount of the compound to be added is preferably 0.0/-20 g, particularly preferably 0.7 to 5 parts by weight, per 100 parts by weight of the binder resin.

(Examples) The present invention will be explained in more detail by Examples below, but the present invention is not limited by the Examples unless it exceeds the gist thereof. In each of the Examples and Comparative Examples, "1 part" means "1 part by weight".

(Example 1) Saturated polyester resin ioo part Compound 7
Part 3 C, L Pigment Red g t
Part s: Zinc Salicylate Complex Compound / Part The above materials were melt-kneaded in a hot roll mill, cooled, coarsely ground using a hammer mill, and then finely ground using an air jet type pulverizer.

The obtained fine powder was classified to select particles having a particle size of 5 to 231 parts m to obtain a 7-color toner. 6 parts of this color toner was added to 700 parts of iron powder and mixed in a V-type mixer to form a developer.

Using this developer, a document copied using a dry plain paper electrophotographic copying machine was exposed to a carbon arc fade meter (carbon arc auto fade meter manufactured by Suga Test Instruments Co., Ltd.) for several hours, and then the color difference was measured.ΔE' a When b = /, J b , there was little change in color.

(Comparative Example/) The same procedure as in Example 1 was carried out except that the compound 1 was not used as a material. ΔE'ab −,7,? ff, and the change in color was remarkable.

(Example 1) The same procedure as in Example 1 was performed except that C, 1, Pigment Red I/W was used as Pigment Yellow /J as the material, and the color change was ΔE'ab = /,, 2A. There weren't many.

(Comparative Example 2) When the same procedure as in Example 1 was carried out except that the above-mentioned compound / was not used as a material, ΔE'ab=3.7 g, and the color change was remarkable.

(Example 3) When the same procedure as in Example 1 was carried out except that the above compound was used as the material, there was little change in color with ΔE'ab = /, ni/.

(Example 1) The same procedure as in Example 1 was performed except that the compound 3 was used instead of the compound 3 as the material. ΔE'ab=7.gl, and there was little change in color.

(Effects of the Invention) The color toner for electrophotography of the present invention has particularly excellent light resistance,
It always gives stable and good images.

Claims (1)

[Claims] (1) Binder resin, colorant and the following general formula (I
) A color toner for electrophotography, characterized by containing a compound represented by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・( I
) (In the formula, R^1 represents a hydrogen atom, a hydroxyl group or a lower alkoxy group, R^2 represents a hydrogen atom, a hydroxyl group or a carboxyl group, R^3 represents a hydroxyl group, a lower alkoxy group or a halogen atom, R ^4 represents a hydrogen atom or a sulfonic acid group.)