JPH0355563A - Yellow toner for electrophotography - Google Patents

Abstract

PURPOSE:To obtain good spectral reflection characteristics and good electrostatic charge characteristics and to obtain always stable images by incorporating a specific compd. into a binder resin. CONSTITUTION:This toner contains the compd. expressed by formula I in the binder resin. In the formula, X denotes a halogen atom. The halogen atom is exemplified by a chlorine atom, bromine atom, etc. The amt. of the coloring agent to be added into the toner is preferably 0.1 to 30pts.wt., more particularly 0.5 to 10pts.wt. per 100pts.wt. binder resin in total. The coloring effect as a yellow color is poor if the amt. of the compd. to be added is too low and the fixability is poor if the amt. is conversely too high. An undesirable tendency is exhibited in such a case. The characteristics required as the color toner are satisfied with good balance in this way; above all, the excellent spectral reflection characteristics and the good electrostatic charge characteristics are obtd. and the always stable images are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an electrophotographic yellow toner, and more particularly to an electrophotographic yellow toner containing a specific compound.

(Prior art) The electrophotographic method is described in U.S. Patent No. 2297691,
As disclosed in various publications such as Japanese Patent Publication No. 23910 and Japanese Patent Publication No. 43-24748, generally an electrical latent image of electrostatic charges is formed on a photoreceptor containing a photoconductive material by various means, and then the electrostatic latent image is formed. The latent image is developed as a powder image with toner, and the powder image is transferred to paper or the like as required, and then fixed by heating, pressure, solvent vapor, or the like.

In addition, in recent years, the electrostatic latent image of a document is exposed by being exposed to spectral light, and this is developed with colored toner to obtain a colored copy image, or the copy images of each color are superimposed. A color copying method for obtaining full-color copied images has been put into practical use, and color toners such as yellow, magenta, and cyan, which are made by dispersing each color of dye and lubricant or pigment in a binder resin, have been manufactured. There is.

The toner used is particles made by dispersing coloring agents such as dyes and pigments in resin such as polyester, and finely pulverizing the particles to about 1 to 30 pm. It is used by mixing with a carrier material such as.

(Problems to be Solved by the Invention) However, it has been difficult for conventional color toners to satisfy various performances required of color toners. In other words, conventional color toners: (1) lack light transparency, which makes color reproduction difficult when overprinting multiple colors; and when creating transparency for overhead projects (OHP); A transparent image cannot be obtained.

(2) Good hue and color cannot be obtained because the spectral reflection characteristics are not good.

(3) Due to insufficient fastness to light and heat, the color of the copied image fades during storage.

(4) Due to the low affinity between dyes and pigments and binder resin,
The dyes and pigments migrate to the photoreceptor, reducing its performance.

(5) Due to poor charging characteristics, the color balance deteriorates as the number of copies is increased, and problems such as fogging and density changes occur on images.

As a result of intensive studies to solve these problems, the present inventors have found that by using a compound represented by a specific structural formula, the above problems can be solved and an excellent toner that satisfies various required characteristics in a well-balanced manner can be created. The present invention was achieved by learning that the following can be obtained.

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

Y (In the formula, X represents a halogen atom.) (Function) The present invention will be explained in detail below. The quinophthalone yellow compound represented by the general formula (1) used in the present invention will be explained.

Examples of the halogen atom represented by X in general formula (1) include chlorine atom and bromine atom, and specific compounds include those shown in Table 1.

These compounds were prepared by 2. using known methods. Methyl. 3. Hydroxy-4. Carboxyquinoline and naphthalene2,3
- dicarboxylic acid anhydrides in an inert solvent, and further halogenation.

The colorant to be contained in the yellow toner of the present invention is not limited to the specific examples listed above, but it is also possible to use a mixture of two or more compounds represented by the general formula (1) above. It is. Further, it is permissible to use compounds other than these compounds as colorants as long as the desirable effects produced by using the compounds in Table 1 are not impaired. Furthermore, the compound can be mixed with toners of other colors and used for color improvement.

On the other hand, the binder resin for the yellow toner of the present invention can be selected from a wide range including known ones, but colorless and transparent ones are preferable, such as polystyrene,
Chloroboristyrene, 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 (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer) and styrene-phenyl acrylate copolymer), styrene-methacrylate ester copolymer (
styrene. Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacnolate copolymer, and styrene. phenyl methacrylate copolymers, etc.), styrenic resins such as styrene-10-methyl chloroacrylate copolymers, and styrene-acrylonitrile-acrylic ester copolymers (styrene or monopolymers or copolymers containing styrene or styrene substitutes) ), vinyl chloride resin, rosin-modified maleic acid resin, phenolic resin, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin,
Polyurethane resin, silicone resin, ketone resin, ethylene. Examples include ethyl acrylate copolymers, xylene resins, and polyvinyl butyral resins, and 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.

The total amount of the colorant added to the toner is preferably 0.1 to 30 parts by weight, particularly preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the binder resin. If the amount added is too small, the yellow 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 quaternary ammonium salt is used, and as the negative charge control agent, an acidic or electron-withdrawing substance such as metal chelates or metal-containing dyes is 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. A suitable amount is 0.1 to 10 parts by weight.

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. . 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 amount added is suitably 0.1 to 10 parts by weight per 100 parts by weight of the binder resin. Furthermore, toner particles include Ti02 and AI203.
By adding special powders such as , Si02, etc. 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 10 parts by weight per 100 parts by weight of the binder resin.

Various conventional toner manufacturing methods can be applied to the toner manufacturing method of the present invention, and examples of general manufacturing methods include the following.

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 ■ type mixer,
Uniformly disperse using an S-type mixer, Henschel mixer, etc.

Next, the dispersion is melt-kneaded using a double-arm kneader, pressure kneader, extruder, roll mill, or the like. The mixed material is pulverized using a pulverizer such as a hammer mill, cutter mill, jet 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 10 to 100 parts of a magnetic material such as a known iron powder carrier or ferrite carrier, or a carrier coated on the surface thereof, based on 1 part of the toner.

(Examples) The present invention will be explained in more detail by Examples below, but the present invention is not limited by the Examples unless the gist thereof is exceeded. In addition, in each example and comparative example, "part"
The term "parts by weight" refers to "parts by weight."

(Example 1) 100 parts of unsaturated polyester resin No. 1 in Table 1 above. 3 parts of the compound of No. 1 1 part of the zinc salicylate complex compound The above materials were melt-kneaded in a hot roll mill, cooled, and then coarsely ground using a hammer mill, and then finely ground using a pulverizer using an air-jet system. The obtained fine powder was classified to select particles having a particle size of 5 to 25 llm to obtain a yellow toner. 6 parts of this yellow toner was added to 100 parts of iron powder and mixed in a V-type mixer to prepare a developer.

When this developer was used for copying with a dry plain paper electrophotographic copying machine, there was no capri, the spectral reflection characteristics were good, and clear images were obtained. Further, when 20,000 copies were continuously made using this developer, there was no deterioration in the quality of the copied images. The image densities of the initial copy and after 20,000 copies are 1.45 and 1.43, and the Teiden amount of this toner is -15.9 pC/g and -16.21 lC at the initial copy and after 20,000 copies. /g, and the amount of charge was stable.

(Example 2) Styrene-acrylic acid n. When the same procedure as in Example 1 was carried out except that a butyl copolymer was used, the same results as in Example 1 were obtained.

(Example 3) No. 3 in Table 1 above. No. 1 in Table 1 above instead of compound No. 1. When the same procedure as in Example 1 was carried out except that compound No. 2 was used, the same results as in Example 1 were obtained.

(Example 4) No. in Table 1 above. No. 1 in Table 1 above instead of compound No. 1. When the same procedure as in Example 1 was carried out except that compound No. 3 was used, the same results as in Example 1 were obtained.

(Effects of the Invention) As explained above, the yellow toner for electrophotography of the present invention has
It satisfies the properties required of a color toner in a well-balanced manner, and among others, has excellent spectral reflection properties and good charging properties, so that stable images can always be obtained.

Claims (1)

[Claims] (1) A yellow toner for electrophotography, which contains a compound represented by the following general formula (I) in a binder resin. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, X represents a halogen atom.)