JPH0816807B2 - Color toner for electrophotography - Google Patents

Description

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

(Prior Art) In recent years, an electrostatic latent image of a document exposed by spectral light is formed, and this is developed with color toner of each color to obtain a colored copy image, or the copy image of each color is superposed. Practical use of a color copying method to obtain full-color copied images
As a color toner used for this, a yellow color obtained by dispersing dyes and / or pigments of each color in a binder resin,
Color toners such as magenta and cyan are manufactured.

(Problems to be Solved by the Invention) However, the conventional color toners do not always sufficiently satisfy various performances required for the color toners.

In other words, with conventional color toners: ・ Because of insufficient light transmission, color reproduction becomes difficult when multicolor overprinting is performed.
A good transmission image cannot be obtained when creating the Transparency for P).

・ Because of the poor spectral reflection characteristics, good hue and color cannot be obtained.

・ Due to lack of fastness to light and heat, the copy image fades while left unattended.

・ Due to the low affinity between the dye and pigment and the binder resin, the dye and pigment migrate to the photoconductor and the like, which deteriorates the performance.

Since the charging characteristics are not good, the color balance is lost as the number of copies is increased, and defects such as a change in fog density occur on the image.

There were problems such as.

(Means for Solving the Problems) As a result of intensive studies made by the present inventors in order to solve such problems, an excellent toner in which the above problems have been solved by using a colorant having a specific structure is obtained. As a result, the present invention has been reached.

That is, the gist of the present invention is an electrophotographic color toner containing an anthraquinone derivative represented by the general formula (I) as the colorant in an electrophotographic color toner containing a colorant and a binder resin. Exists in toner.

(In the formula, R represents hydrogen or a lower alkyl group, and X represents a halogen atom.) (Operation) Hereinafter, the present invention will be described in detail.

As the binder resin for toner, it is possible to widely use including known ones, but colorless and transparent ones are preferable, for example, 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 acid ester copolymer (for example, 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 copolymer (for example, styrene-
Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.),
Styrene resins such as styrene-α-chloromethyl acrylate copolymer and styrene-acrylonitrile-acrylic ester copolymer (styrene and / or styrene-substituted homopolymer or copolymer), vinyl chloride resin, styrene -Vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene,
Although there are ionomer resins, polyurethane resins, silicone resins, ketone resins, ethylene-ethyl acrylate copolymers, xylene resins, polyvinyl butyral resins, etc., styrene resins, polyester resins, silicone resins are particularly preferable in the practice of the present invention. , Epoxy resin, and the like. Further, the above resins are not limited to being used alone, but may be used in combination of two or more kinds.

In the compound represented by the general formula (I) used as a colorant in the present invention, R represents a hydrogen atom or a lower alkyl group such as methyl and ethyl, X represents a halogen atom such as chlorine, bromine and iodine, and The specific examples of the anthraquinone derivative are as follows.

The present invention is not limited to the compounds of the above specific examples, and it is also possible to use a mixture of two or more of them.

Further, the compound represented by the general formula (I) can be used as a main component of the colorant of the magenta toner, but in the case of a toner of another color, the compound of (I) may be added for improving the color. It is possible.

In addition, the amount of colorant added to the toner is the binder resin.
0.1 to 30 parts by weight per 100 parts by weight is desirable, especially 0.5
~ 10 parts by weight is desirable. If the addition amount is too small, the coloring effect as magenta will be poor, and if it is too large, the fixability will be inferior, which is not preferable.

The charge control of the toner may be performed by the binder resin and the dye / pigment itself, but if necessary, a charge control agent that does not cause a problem in color reproduction may be used together. Use a quaternary ammonium salt, a basic / electron-donating organic substance as the positive charge control agent, and a metal chelate, a metal-containing dye, an acidic or electron-withdrawing organic substance, etc. as the negative charge control agent. You can

The addition amount of the charge control agent can be determined in consideration of the chargeability of the binder resin, the manufacturing method including the addition amount / dispersion method of the colorant, and the chargeability of other additives. 0.1 to 10 parts by weight is suitable.

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

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

Furthermore, solid electrolytes, polymer electrolytes, charge transfer complexes, conductors such as metal oxides such as tin oxide, semiconductors and / or
Alternatively, the electrical properties of the toner can be controlled by adding a ferroelectric substance, a magnetic substance, or the like.

In addition, auxiliary agents such as various plasticizers and release agents may be added to the toner for the purpose of adjusting thermal characteristics and physical characteristics. The appropriate amount of addition is 0.1 to 10 parts by weight.

Furthermore, for the toner particles, TiO ₂ , Al ₂ O ₃ and / or
Alternatively, by adding fine powder such as SiO ₂ and coating the surface of the toner particles with these, the fluidity and aggregation resistance of the toner can be improved. The addition amount is preferably 0.1 to 10 parts by weight.

Various conventionally used toner production methods can be applied to the toner production method of the present invention. For example, the following examples can be given as general production methods.

First, a resin and a colorant (such as a charge control agent in some cases) are uniformly dispersed with a ball mill, a V-type mixer, an S-type mixer, a Henschel mixer, or the like. The dispersion is then double-armed kneader,
Melt and knead with a pressure kneader. The mixture is crushed by a crusher such as a hammer mill, a jet mill or a ball mill, and the obtained powder is classified by an air classifier or the like.

The obtained color toner can be mixed with a carrier to form an electrophotographic developer, and can be used for copying by a conventionally practiced electrophotographic method. As the carrier, it is preferable to use 10 to 100 parts of a magnetic substance such as a known iron powder-based or ferrite-based carrier or a material coated on the surface thereof with respect to 1 part of the toner.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded. In addition, "part" in an Example represents a "weight part."

(Example 1) Unsaturated polyester resin 100 parts The above compound 3 parts Zinc salicylate complex compound 1 part is melt-kneaded with a hot roll mill, cooled and coarsely pulverized with a hammer mill, and then finely pulverized with an air jet pulverizer. Crushed. Particle size 5-25
μm was selected and used as a toner. 6 parts of this toner was added to 100 parts of iron powder and mixed by a V-type mixer to obtain a developer.

When this developer was used to make a copy on a dry plain paper electrophotographic copying machine, there was no fog, the spectral reflection characteristics were good, and a clear image was obtained. Further, using this developer, 20,000 sheets were continuously copied, but the quality of the copied image was not deteriorated. The image densities after the initial copy and after copying 20,000 sheets are 1.46 and 1.43, respectively, and the charge amounts of this toner are -15.7 μc / g and -16.8 μc / g at the beginning of copying and after copying 20,000 sheets, respectively. , The charge amount was stable.

(Example 2) Except that a styrene-n-butyl acrylate copolymer was used instead of the unsaturated polyester resin, the same procedure as in Example 1 was carried out, and a clear image was obtained with good spectral reflection characteristics. .

(Example 3) The same operation as in Example 1 was carried out except that the above compound was used in place of the above compound as a colorant, and a clear image having good spectral reflection characteristics was obtained.

(Example 4) The same operation as in Example 1 was carried out except that the above compound was used in place of the above compound as a coloring agent, and a clear image having good spectral reflection characteristics was obtained.

(Example 5) The same operation as in Example 1 was carried out except that the above compound was used instead of the above compound as a colorant, and a clear image having good spectral reflection characteristics was obtained.

(Effects of the Invention) As described above, the color toner of the present invention has excellent spectral reflection characteristics, good charging characteristics, and stably gives a clear image.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiko Yanagibori 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd. (56) Reference JP 61-167954 (JP, A) JP 59-220750 (JP, A) JP 63-96667 (JP, A) JP 63-141073 (JP, A)

Claims (1)

[Claims] 1. An electrophotographic color toner comprising a colorant and a binder resin, wherein the colorant comprises an anthraquinone derivative represented by the general formula (I). (In the formula, R represents a hydrogen atom or a lower alkyl group, X
Represents a halogen atom. )