JP2618427B2 - Yellow color toner composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a color toner, particularly to a dye for a negatively chargeable color toner for an electrostatic charge phenomenon, and a color toner.

As a method for forming a visible image by developing an electric latent image with a color toner, a conventional electrostatic charge printing method, an electrophotographic method, and the like are well known. Generally, an electric latent image is formed on a photoconductor showing photoconductivity by various means using a photoconductive substance, and then the latent image is developed with toner to obtain a visible image, or If necessary, a powder image is transferred onto paper or the like, and then fixed by heating, pressurizing, or solvent vapor to obtain a visible image.

In order to obtain a color multicolor image, a document is exposed using a color separation filter, and the above process is repeated a plurality of times using a color toner such as yellow, magenta, and cyan to form a color image.

As a toner for developing an electric latent image, conventionally, particles obtained by pulverizing a dispersion of a colorant in a binder resin such as polystyrene into about 0.1 to 50 μm have been used. This color toner is usually mixed with a carrier substance such as glass beads or iron powder and used for developing a latent image of an electric latent image.

(Problems to be Solved by the Prior Art and the Invention) These color toners are required to have various physical and chemical properties. However, many of the known color toners have some defects as described below.

(1) The temperature change adversely affects the triboelectric properties of the color toner.

(2) The density obtained by the collision of the color toner particles and the carrier particles due to the repeated development for continuous use and the mutual deterioration of the particles and the photosensitive plate changes, or the background density increases, and the quality of the copy is reduced. Lower.

(3) If an attempt is made to increase the density of a copied image by increasing the amount of color toner adhering to the surface of a photosensitive plate having a latent image,
Usually, the background density increases, and a so-called fog phenomenon occurs.

(4) Transparency may be lost due to multicolor superposition.

(5) Each color toner may be inferior in melt miscibility.

(6) Spectral reflection characteristics for accurately reproducing an original may be poor.

As many of the known color toners have one or more of the above defects, improvements are needed.

(Means for Solving the Problems) The present inventors have conducted intensive studies to solve the above-described problems of the color toner, and have excellent melt miscibility,
Furthermore, a dye having a stable image density obtained by continuous copying by repeated development and having good yellowness and light fastness was found, and the present invention was completed.

That is, the present invention relates to the following general formula (I) (Wherein, R ₁ , R ₂ , R ₃ and R ₄ are the same or each independently represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.) A yellow color toner containing an anthraquinone dye represented by the formula: A composition.

Specific examples of R ₁ , R ₂ , R ₃ and R _{4 in} the formula (I) include:
Hydrogen atom, fluorine atom, chlorine atom, halogen atom such as bromine atom, methyl group, ethyl group, isopropyl group, n-hexyl group, n-octyl group, n-hexadecyl group, 3,5,
Examples include an alkyl group such as a 5-trimethylhexyl group, and an alkoxy group such as a methoxy group, an ethoxy group, an n-propoxy group, and an n-hexadecyloxy group.

The dye of the formula (I) can be easily obtained by reacting 1,8-dinitroanthraquinone or 1,8-dichloroanthraquinone with thiophenols in the presence of a base such as potassium carbonate by a conventional method. Can be.

As a method for producing a color toner using the coloring matter, the compound of the formula (I) is preferably contained in the binder resin in an amount of 0.1 to 1%.
It can be obtained by containing 0% by weight.

Hereinafter, the components of the color toner of the present invention will be described in detail.

Particularly important components of the color toner are:
It is a compound represented by the aforementioned general formula (I). These compounds are contained in the binder resin and give excellent chargeability as a toner.

The addition amount of these dyes for yellow color toner is
The chargeability of the binder resin, or a colorant added as an auxiliary,
Alternatively, the chargeability of the additive, and furthermore the compatibility with the binder resin,
Alternatively, since it is determined by a dispersion method or the like, it is not limited uniformly, but generally speaking, about
It is desirable to use it in the range of 0.1 to 10% by weight.

As the binder resin applied to the color toner of the present invention,
All known ones are possible, for example, polystyrene, poly p-chlorostyrene, a monomer of styrene such as polyvinyltoluene and a substituted product thereof, a styrene-vinylnaphthalene copolymer, a styrene-methyl acrylate copolymer, Styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate Copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, Styrene-butadiene copolymer, polystyrene Styrene copolymers such as isobrene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride , Polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, Chlorinated paraffin, paraffin wax or the like can be used alone or as a mixture.

Examples of the carrier as a developer include magnetic substances such as iron, cobalt, and nickel, alloys and mixtures thereof, and coatings on the surfaces thereof.

(Operation) The conventional toner has problems such as poor light fastness of a copy, occurrence of a fogging phenomenon, and poor melt miscibility. However, the toner composition of the present invention has excellent melt miscibility. However, it is a dye having a stable yellow color and good light fastness, which is obtained in continuous copying by repeated development, and is extremely valuable in practical use.

(Examples) Hereinafter, the present invention will be described in more detail with reference to examples. “Parts” in the examples represent parts by weight. The compound used was manufactured by a conventional method.

The light resistance of Examples 1 to 15 and Comparative Examples 1 and 2 was determined by blue scale after irradiation with a fade meter (carbon arc lamp) at 63 ° C. for 60 hours.

Example 1 1,8-dithiophenoxyanthraquinone 5 represented by
Parts, toner resin [styrene-acrylic acid ester copolymer; trade name: Hymer TB-1000F (manufactured by Sanyo Chemical)] 95 parts are mixed and pulverized by a ball mill, heated to 150 ° C., melt-mixed, cooled, and then cooled by a hammer mill. And then coarsely pulverized by an air jet type pulverizer. After further classification, 1 to 20 μm is selected to obtain a toner.

For 10 parts of this toner, use carrier iron powder (trade name, EFV2
90/50; Nippon Iron Powder Co., Ltd. 90 parts were uniformly mixed to obtain a developer. Using this developer, copying was performed with a dry plain paper electrophotographic copying machine (trade name, NP-5000; manufactured by Canon KK), and a clear yellow image without fog was obtained.
In addition, the light resistance of the copy was good and it was grade 7.

Example 2-15 The same procedures as in Example 1 were carried out, except that the dyes shown in Table 1 were used instead of 1,8-dithiophenoxyanthraquinone, and the results were as good as in Example 1. Results were obtained. Table 1 also shows the results.

Comparative Example 1 The dye for yellow color toner in the toner composition of Example 1 was a compound of the following formula (II) The procedure of Example 1 was repeated, except that 5.0 parts were used, to give a yellow lemon yellow, but the light fastness was poor and the grade was tertiary.

Comparative Example 2 The dye for yellow color toner in the toner composition of Example 1 was a compound of the following formula (III) The procedure of Example 1 was repeated, except that 5.0 parts were used. As a result, a reddish yellow color was obtained. However, the compatibility with the toner resin was poor, and the phenomenon of fogging occurred, and the light resistance was poor. It was grade 5.

(Effect of the Invention) With the developer using each dye in the example, the one obtained by copying can obtain a clear yellow image without fog,
In addition, although the light fastness is also good, the image obtained by copying with the developer using each dye in the comparative example has poor light fastness,
Further, it is found that the compatibility between the toner and the resin is poor, and fogging occurs.

 ──────────────────────────────────────────────────続 き Continuation of the front page Examiner Seiji Matsumoto (56) References JP-A-61-51156 (JP, A) JP-A-60-15991 (JP, A)

Claims (1)

(57) [Claims] 1. The compound of the formula (I) in a binder resin (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are the same or each independently represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.) Yellow color toner composition.