JP2644298B2 - Yellow color toner composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color toner, and more particularly to a composition for a negatively chargeable color toner for electrostatic charge development.

As a method for forming a visible image by developing an electric latent image with a color toner, a conventional electrostatic printing method, an electrophotographic method, and the like are well known. In general, by various means using a photoconductive substance, an electric latent image is formed on a photoconductor showing photoconductivity, and then the latent image is developed with toner to obtain a visible image, or After the powder image is transferred to paper or the like, if necessary, it is 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 color toners such as yellow, magenta, and cyan to form a color image.

Conventionally, as a toner for developing an electric latent image, 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 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 described below.

(1) The triboelectric properties of the color toner are not affected by the temperature change.

(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, or
The background density must not increase and degrade the quality of the copy.

(3) When 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, the background density generally increases, so that the so-called fogging phenomenon must not occur.

(4) Transparency must not be lost in order to perform multicolor superposition.

(5) Each color toner needs to be excellent in melt miscibility.

(6) Spectral reflection characteristics must be good for accurately reproducing an original.

Many of the known color toners cannot be said to sufficiently satisfy the above-mentioned required characteristics, and at present, improvement is demanded.

(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 resin represented by the following general formula (I): (In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkoxyalkyl group, an alkoxyalkoxy group, an aralkyl group, an alkoxycarbonyl group, or an alkylcarboxy group.) This is a yellow color toner composition for electrostatic charge development.

Specific examples of R in the formula (I) include a halogen atom such as a hydrogen atom, a chlorine atom, a fluorine atom and a bromine atom, and an alkyl such as a methyl group, an ethyl group, a propyl group, an isobutyl group and an n-octyl group. Group, methoxy group, ethoxy group, n
-Alkoxy groups such as propoxy group, n-hexyloxy group, methoxymethyl group, methoxyethyl group, ethoxyethyl group, alkoxyalkyl groups such as n-propoxyethyl group, n-butoxyethyl group, methoxymethoxy group, ethoxymethoxy group , An alkoxyalkoxy group such as ethoxyethoxy group, benzyl group, phenethyl group, aralkyl group such as γ-phenylpropyl group, methoxycarbonyl group, ethoxycarbonyl group, alkoxycarbonyl group such as n-propoxycarbonyl group, acetyloxy group, ethyl Examples thereof include an alkylcarboxy group such as a carboxy group and an n-propylcarboxy group.

The compound of the general formula (I) can be prepared in the presence of a base such as 1,8-dinitroanthraquinone or 1,8-dichloroanthraquinone and potassium carbonate of hydroxythiophenols.
It is easily obtained by reacting in a polar organic solvent.

As a method for producing a color toner using the yellow dye of the present invention, a color toner is obtained by preferably containing 0.1 to 10 parts by weight of a compound of the formula (I) in a binder resin. Can be.

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

Particularly important components of the color toner are:
An anthraquinone compound represented by the above general formula (I).

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,
Although all known ones are possible, for example, polystyrene, poly p-chlorostyrene, a homopolymer 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, styrene Down - isoprene copolymer, styrene - acrylonitrile - indene copolymer, styrene -
Maleic acid copolymer, styrene-based copolymers such as 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, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorine Paraffin, paraffin wax and the like can be used alone or in combination.

As the carrier agent as a developer, for example, a magnetic substance such as iron, cobalt, nickel or the like, an alloy or a mixture thereof, or a coating on the surface thereof is provided.

(Operation) The conventional toner composition has problems such as poor light fastness of a copy, occurrence of fogging phenomenon, and poor melt miscibility, but the toner composition of the present invention has excellent melt miscibility. Having an image density obtained by continuous copying by repeated development, a stable yellow color with a good light fastness dye,
It is extremely valuable in practice.

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

In addition, the light resistance of Examples 1 to 17 and Comparative Examples 1 and 2 was determined after irradiation for 60 hours at 63 ° C. with a fedometer (carbon arc lamp).

Example 1 5 parts of 1,8-p- (hydroxyphenylthio) anthraquinone and 95 parts of a resin for toner [styrene-acrylate copolymer; trade name Hymer TB-1000F (manufactured by Sanyo Chemical)] are mixed and pulverized by a ball mill. Thereafter, the mixture is heated to 150 ° C., melt-mixed, cooled, and coarsely pulverized using a hammer mill, and then finely 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. Copying was performed using a dry plain paper electrophotographic copier (trade name, NP-5000; manufactured by Canon KK) using this developer.
A clear yellow image without fog was obtained. or,
The light resistance of the copy was good and was 7th grade.

Examples 2 to 17 In the same manner as in Example 1 except that the dyes shown in Table 1 were used, high-performance color toner compositions were obtained.

(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) A 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. 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, the light resistance is good, but the image obtained by copying with the developer using each dye in the comparative example has poor light resistance, and further has poor compatibility with the toner and the resin, and may cause fogging. I understand.

The dye of the formula (I) is used, for example, as a polymerizable dye by reacting with vinyl isocyanate. By copolymerizing styrene, methyl acrylate, or the like, it is possible to prepare a dye resin having a covalent bond in the resin. And an excellent color toner composition can be obtained.

Claims (1)

(57) [Claims] 1. A compound of the formula (I) in a binder resin (In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkoxyalkyl group, an alkoxyalkoxy group, an aralkyl group, an alkoxycarbonyl group, or an alkylcarboxy group.) A yellow color toner composition for electrostatic charge development.