JPH0248676A - Yellow color toner composition - Google Patents

Abstract

PURPOSE:To eliminate the fogging of the image obtd. by copying and to obtain the sharp yellow color image by incorporating the anthraquinone dye expressed by the general formula I into the binder resin of the yellow dye color toner compsn. for electrostatic charge development. CONSTITUTION:This compsn. contains the anthraquinone dye expressed by the general formula I into the binder resin of the yellow color toner. In this formula, R denotes a hydrogen atom, halogen atom, alkyl group, alkoxy group, alkoxy alkyl group, alkoxycarbonyl group or alkylcarboxy group. The dye of the excellent melt miscibility of the toner compsn. is provided and the copying is executed by the developer consisting of such compsn., by which the sharp yellow color image having no fogging is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a color toner, particularly a negatively charged color toner composition for electrostatic charge development.

Conventionally, electrostatic printing, electrophotography, and the like are well-known methods for forming visible images by developing electrical latent images with color toners. Generally, a photoconductive material is used to form an electrical latent image on a photoconductive photoreceptor by various means, and the latent image is then developed with toner to obtain a visible image; After transferring the powder image to paper or the like as necessary, it is fixed by heating, pressure, solvent vapor, etc. to obtain a visible image.

To obtain a multicolor image, a document is exposed to light using a color separation filter, and the above steps are repeated multiple times using color toners such as yellow, magenta, and cyan to create a color image.

As a toner for developing an electrical latent image, conventionally used particles are particles obtained by dispersing a coloring agent in a binder resin such as polystyrene and pulverizing the particles to about 0.1 to 50 microns. This color toner is usually mixed with a carrier material such as glass beads or iron powder and used to develop an electrical latent image.

(Prior Art and Problems to be Solved by the Invention) These color toners are required to have various physical and chemical properties as shown below.

(I) Friction characteristics of color toners are not affected by temperature changes.

(2) The density obtained changes due to collision between color toner particles and carrier particles due to repeated development for continuous use, and mutual deterioration of those particles and the photosensitive plate, or
The background density must not increase and reduce the quality of the copy.

(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 the photosensitive plate having a latent image, the background density will usually increase, so the so-called fog phenomenon must not occur.

(4) Do not lose transparency when layering multiple colors.

(5) Each color toner needs to have excellent melt compatibility.

(6) In order to accurately reproduce the original, it is necessary to have good spectral reflection characteristics.

At present, many of the known color toners do not fully satisfy the above-mentioned required characteristics, and improvements are currently desired.

(Means for Solving the Problems) The present invention has been made through intensive studies to solve the problems of the above-mentioned color toners, and has been developed to have excellent melt compatibility, and furthermore, to provide an image density that can be obtained by continuous copying through repeated development. The present invention was completed by discovering a stable yellow colorant with good light fastness.

That is, in the present invention, the following general formula N) (wherein 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 charge development.

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

-S Compounds of formula (I) can be easily obtained by reacting 1,8-dinitroanthraquinone or 1,8-dichloroanthraquinone with hydroxythiophenols in a polar organic solvent in the presence of a base such as potassium carbonate. can get.

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

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

Particularly important constituent components of color toners are anthraquinone compounds represented by the above-mentioned general formula (I).

The amount of these yellow color toner pigments to be added depends on the chargeability of the binder resin, the chargeability of the auxiliary colorant or additive, the compatibility with the binder resin, or the dispersion method. etc., so it is not uniformly limited, but generally speaking, it is approximately 0 for the binder resin.
．． It is desirable to use it in the range of 1 to 10 (wt%).

All known binder resins can be used as the binder resin for the color toner of the present invention, such as polystyrene,
Monopolymers of styrene and its substituted products such as polyP-chlorostyrene and polyvinyltoluene, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, 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 Polymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-
Styrenic copolymers such as 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, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. They can be used alone or in combination.

Further, as a carrier agent for a developer, for example, iron,
Magnetic substances such as cobalt and nickel, alloys and mixtures thereof, or coatings on the surfaces thereof.

(Function) Conventional toners have had problems such as poor light resistance of copies, occurrence of fogging phenomenon, and poor melt compatibility, but the toner composition of the present invention has excellent melt compatibility. However, it is a dye with a stable yellow color and good light fastness, and is extremely valuable in practical use, since the image density obtained by continuous copying through repeated development is stable.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples. The compounds used were produced by conventional methods.

The light resistance of Examples 1 to 17 and Comparative Example 1.2 was determined after 60 hours of irradiation using a fetometer (carbon arc lamp) at 63°C.

For 10 parts of this toner, carrier iron powder (trade name, E
F V 250/400. 90 parts (Japanese iron powder type) were uniformly mixed to prepare a developer. Using this developer, a dry plain paper electrophotographic copying machine (product name, NP-5000, Canon)
When copying was carried out using a copying machine (manufactured by K. K.), a clear yellow image with no fog was obtained. Moreover, the light resistance of the copy was also good and was grade 7.

Examples 2 to 17 Using the dyes shown in Table 1, in exactly the same manner as in Example 1,
A high performance color toner composition was obtained.

5 parts of 1+8-(p-hydroxyphenylthio)anthraquinone, toner resin [styrene-acrylic acid ester copolymer; trade name) 1 imer TB1000F
(manufactured by Sanyo Chemical)] After mixing and pulverizing 95 parts in a ball mill,
The mixture is heated to 150°C, melt-mixed, cooled, and then coarsely ground using a hammer mill, and then finely ground using an air jet type pulverizer.

The toner is further classified to select 1 to 20 microns.

(Margin below) Example table General formula (I) Substitution position of hydroxyl group -CI 9-C*Hs p-C11,0 m-CH30CHt p-c! H.

p-C1HsOC1H40 o-CJsCHlCHx o-CH3COO -Br -CH- CH3on-C3 H2CO-CH30 CJ4. HgCl2 m-CHzOCo Lightfastness (Comparative Example 1) The yellow color toner pigment in the toner composition of Example 1 was replaced with 5.0 parts of a compound of the following formula (If), and the rest was the same as in Example 1. As a result, a lemon yellow color was obtained, but its light resistance was poor and grade 3.

(Comparative Example 2) The procedure was carried out in the same manner as in Example 1 except that the yellow color toner pigment in the toner composition of Example 1 was replaced with 5.0 parts of the compound υ of the following formula (I[I). Although a reddish yellow color was obtained, the compatibility with the toner resin was poor, fog development occurred, and the light resistance was poor, being 4th to 5th grade.

(Effect of the invention) When copying was performed using the developer using each dye in the examples, a clear yellow image without fogging was obtained, and the light resistance was also good. It can be seen that images copied using developers using the respective dyes have poor light fastness, and furthermore, the compatibility between toner and resin is poor, resulting in fogging.

In addition, the dye of formula (I) can be used as a polymerizable dye by reacting with vinyl isocyanate, for example, and copolymerized with styrene, methyl acrylate, etc., to produce a dye resin covalently bonded in the resin. can be easily carried out, and an excellent color toner composition can be obtained.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] In the binder resin, there are general formulas (I) ▲mathematical formulas, chemical formulas, tables, etc.▼(I) (wherein R is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkoxyalkyl A yellow color toner composition for electrostatic charge development, characterized in that it contains an anthraquinone dye represented by the following formula: alkoxyalkoxy group, alkoxyalkoxy group, aralkyl group, alkoxycarbonyl group, or alkylcarboxy group.