JPH0667466A - Dye for post-dyeing color toner and color toner - Google Patents

Abstract

PURPOSE:To obtain bright and transparent picture image and to improve light resistance by using a color toner dyed with a specified color toner dye for copying. CONSTITUTION:An azo dye expressed by formula is used as the dye for a post-dyeing color toner. In formula, an aromatic ring A is a phenyl group which may have substituents, an aromatic ring B is a phenylene group which may have substituents, and R1 and R2 are same or different hydrogen atoms or alkyl groups or allyl group which may have substituents. The color toner using this dye is obtd. by dyeing a toner resin with the dye expressed by formula and a nonionic or anionic dispersant. The obtd. color toner has excellent transparency without influence of temp. on the triboelectric characteristics. Picture images in continuous copies obtd. by repetition of development are stable and the copy has good light resistance and rigidity.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a color toner for electrophotography.

[0002]

2. Description of the Related Art As a method of developing an electric latent image with a color toner to form a visible image, an electrostatic charge printing method, an electrophotographic method and the like are well known. These are those in which a photoconductive substance is used to form an electric latent image on a photoconductive member having photoconductivity by various means, and then the latent image is developed with toner and transferred to paper or the like. It is a method of obtaining a visible image by fixing with heat, pressure, solvent vapor or the like. To obtain a color multicolor image, the original is exposed using a color separation filter,
The above steps are repeated a plurality of times using color toners such as yellow, magenta and cyan to form a color image.

As a toner for developing an electric latent image, particles in which a colorant is dispersed in a polyester resin and pulverized to about 1 to 50 .mu. Are conventionally used.
This is called a pulverized toner. This color toner is usually mixed with a carrier material such as glass beads or iron powder and used for developing an electric latent image.

Generally, in order to reproduce a precise image, it is necessary for the toner to have a small particle size, but it is difficult to manufacture a small particle size toner with the conventional pulverized color toner, so that the particle size is not uniform. However, there are problems that fog is caused, a precise image cannot be obtained, and the light resistance of the copy is poor. Therefore, in recent years, post-dyeing type color toner has been developed as an alternative to the pulverization method toner.
In this method, toner particles having a spherical shape and a small particle size are obtained in advance by a polymerization method such as an emulsion polymerization method, a suspension polymerization method and a lead polymerization method, and then colored with each dye.

These color toners are required to have various physical and chemical characteristics shown below. (1) The triboelectric characteristics of the color toner are not affected by the temperature change. (2) Due to collision between color toner particles and carrier particles due to repeated development for continuous use, and mutual deterioration of those particles and photosensitive plate, the obtained density may change or the background density may increase, resulting in a copy copy. Do not reduce the quality. (3) When the color toner is attached to the surface of the photosensitive plate having the latent image, the particle size distribution of the toner particle size is uniform so that the fog phenomenon due to the uneven particle size of the toner does not occur. (4) Transparency must not be lost due to multicolor overlapping. (5) Spectral reflection characteristics are good in order to accurately reproduce the original.

Many of the known color toners cannot be said to sufficiently satisfy the above required characteristics, and there is a strong demand for improvement. Therefore, an object of the present invention is to provide a post-dyeing type color toner in which the above-mentioned properties are improved.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that the following general formula (1)
(Chemical formula 2)

[0008]

[Chemical 2]

[In the formula, the aromatic ring A represents a phenyl group which may have a substituent, and the aromatic ring B represents a phenylene group which may have a substituent. R ₁ and R ₂ may be the same or different from each other and represent a hydrogen atom, an alkyl group which may have a substituent, or an allyl group. ] The azo dye represented by the following is very suitable as a dye for a post-dyeing type color toner, that is, the obtained color toner has excellent transparency, and an image obtained by continuous copying by a repeated phenomenon is The present invention has been completed by finding out that the color toner is stable and has good light fastness of a copy, and has solved the above problems. That is, the present invention is represented by the following general formula (1)

[0010]

[Chemical 3]

[In the formula, the aromatic ring A represents a phenyl group which may have a substituent, and the aromatic ring B represents a phenylene group which may have a substituent. R ₁ and R ₂ may be the same or different from each other and represent a hydrogen atom, an alkyl group which may have a substituent, or an allyl group. ] A dye and color toner for post-dyeing type color toner represented by the following formula.

The present invention will be described in detail below. Specific examples of the substituent on the phenyl group or the phenylene group represented by the aromatic ring A or B in the general formula (1) of the dye for post-dyeing type color toner according to the present invention include a hydrogen atom, a hydroxyl group, a methyl group, Ethyl group, n-propyl group, i-propyl group, n
-Butyl group, i-butyl group, t-butyl group, n-pentyl group, 2-methylbutyl group, n-hexyl group, 2-methylpentyl group, cyclohexyl group and other alkyl groups, methoxy group, ethoxy group, n- Propoxy group, i-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, alkoxy group such as cyclohexyloxy group, trifluoromethyl group, fluorine atom, chlorine atom,
Halogen atom such as bromine atom, cyano group, nitro group, methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-
Butoxycarbonyl group, i-butoxycarbonyl group, n
-Hexyloxycarbonyl group, alkoxycarbonyl group such as cyclohexyloxycarbonyl group, methoxyethoxycarbonyl group, ethoxyethoxycarbonyl group,
Alkoxyalkoxycarbonyl groups such as n-butoxyethoxycarbonyl group and (3-ethoxypropoxy) carbonyl group, alkylamino groups such as methylaminocarbonyl group, ethylaminocarbonyl group, n-butylaminocarbonyl group, dimethylaminocarbonyl group and diethylaminocarbonyl group. Aminocarbonyl group, acetylamino group, ethylcarbonylamino group, n-propylcarbonylamino group, n-butylcarbonylamino group, alkylcarbonylamino group such as i-butylcarbonylamino group, methylsulfonylamino group, ethylsulfonylamino group, n-
An alkylsulfonylamino group such as a propylsulfonylamino group and an n-butylsulfonylamino group, a benzyl group,
Examples thereof include, but are not limited to, aralkyl groups such as a phenethyl group.

Specific examples of R ₁ and R ₂ include a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group and an i-butyl group, 2
-Hydroxyethyl group, 3-hydroxy-n-propyl group, 2-cyanoethyl group, 4-cyano-n-butyl group,
Acetyloxyethyl group, ethylcarbonyloxyethyl group, n-butylcarbonyloxyethyl group, benzyl group, 4-methylbenzyl group, 4-methoxybenzyl group,
Examples thereof include an optionally substituted alkyl group such as a 2-chlorobenzyl group, a methoxyethyl group, an ethoxyethyl group, a 2-chloroethyl group, and a 3-chloro-n-butyl group, and an allyl group. These dyes can be easily produced by a usual method. For example, the following general formula (2)

[0014]

[Chemical 4]

[In the formula, A represents the same as in the general formula (1) (formula 2). ] The substituted aniline compound represented by the formula [3]

[0016]

[Chemical 5]

[In the formula, R ₁ and R ₂ and B are the same as those in the general formula (1) (formula 2). ] It can obtain by carrying out a coupling reaction with the compound represented by these.

The method for producing a color toner according to the present invention is obtained by dyeing a toner resin with a dye represented by the general formula (1) and a nonionic or anionic dispersant.

The dyeing concentration of these color toner dyes varies depending on the dyeability of the toner resin and the required coloring concentration of the color toner, but is 0.1-10.0% by weight.
The concentration.

As the dyeing aid, a nonionic or anionic dispersant is used. As the dispersant used in the post-dyeing type color toner dyeing method of the present invention, if the dispersant itself is colored, there is a washing step etc., but it is not completely bleached, so that the dispersant is colorless or slightly colored. Must be an agent.

Specifically, the nonionic dispersant may be a dispersant having a small degree of coloring which is usually used for water-insoluble dyes such as disperse dyes, and among them, polyoxyethylene alkyl ether type, polyethylene glycol ether type, A dialkyl sulfosuccinate type nonionic dispersant is effective.

As with the nonionic dispersants, the anionic dispersant may be any dispersant that is usually used for disperse dyes, etc., as long as it has little coloration. A system dispersant is effective. These nonionic and anionic dispersants may be used alone or in combination. Further, the amount used is 10 to 100 times the weight of the dye, although it depends on the dyeability of the dye.

As the dyeing solvent, known polar solvents such as water, alcohols and ketones, or a single solvent or a mixture of these solvents can be used.

The alcohols are C ₁ -C ₁₀ alcohols, and among them, particularly preferable ones are, for example, methanol, ethanol, n-propanol, i-propanol, 1-butanol, 2-butanol, i-butanol. And lower alcohols. Particularly preferable examples of the ketones include acetone and methyl ethyl ketone. Examples of the other solvent include polar solvents such as N, N'-dimethylformamide, dimethyl sulfoxide, N, N'-dimethylimidazolidinone.

The dyeing temperature and time vary depending on the desired concentration, but the dyeing temperature is 50 to 100 ° C. and the dyeing time is 5 to 5.
It is advisable to perform it within a range of 60 minutes.

In the present invention, specific examples of the resin for the toner to be dyed are not particularly limited as long as they can be used as the resin for the post-dyeing type color toner, and examples thereof include polystyrene and poly-P-chlorostyrene. A homopolymer of styrene such as polyvinyltoluene and a substitution product thereof, a styrene-vinylnaphthalene copolymer, a styrene-methyl acrylate copolymer, a 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-isobrene 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, chlorinated paraffin, paraffin wax, or a mixture of these resins, etc. Is mentioned.

Examples of the carrier agent as a developing solution include magnetic substances such as iron, cobalt and nickel and alloys and mixtures thereof, or those whose surface is coated.

[0028]

EXAMPLES The present invention will be described in more detail below with reference to examples. The compound used was prepared by a conventional method. In addition, the light resistance of the following Examples and Comparative Examples was evaluated after irradiation with a fade meter (carbon arc lamp) at 63 ° C. for 60 hours. Furthermore, “parts” shown below represent “parts by weight”. Example 1 Formula (4) (Formula 6)

[0029]

[Chemical 6]

5 parts of an azo dye represented by, 2 parts of a PEG polypropylene glycol type nonionic activator (trade name, Epan 785, manufactured by Daiichi Kogyo Co., Ltd.), resin for toner (polyester derivative resin, glass transition point: 40 ° C.) 20 parts of the above / spherical toner having an average particle diameter of 5 to 10 μm) is added to 1000 parts of water, and the temperature is gradually raised from room temperature to 80 ° C. (1 ° C./1 min) and dyeing is performed for 1 hour. After dyeing, water: acetone =
Wash with 1: 1 mixed solvent and air dry. Carrier iron powder (trade name, E
90 parts of FV250 / 400, made by Nippon Iron Powder Co., Ltd. were uniformly mixed to obtain a developer. Dry-type plain paper electrophotographic copying machine (trade name, NP-5000, manufactured by Canon KK) using this developer
After copying, a clear red image without fog was obtained. Also, the light resistance of the copy is good, and 6
It was class.

Examples 2 to 11 Using the dyes shown in Table 1 (Tables 1 and 2), high performance color toners were obtained in exactly the same manner as in Example 1.

[0032]

[Table 1]

[0033]

[Table 2]

Examples 12 to 15 High-performance color toners were obtained in the same manner as in Example 1 except that the dispersants shown in Table 2 (Table 3) were used.

[0035]

[Table 3]

Examples 16 to 20 High-performance color toners were obtained in exactly the same manner as in Example 1 except that the dyeing solvents shown in Table 3 (Table 4) were used.

[0037]

[Table 4]

Comparative Example 1 The dye of Example 1 was prepared according to the following formula (5)

[0039]

[Chemical 7]

A red image was obtained when the same procedure as in Example 1 was carried out in place of 5.0 parts, but the light resistance was poor and the grade was 3.

[0041]

When copying is performed with the color toner dyed with the color toner dye according to the present invention, a clear and transparent image free from fog is obtained and its light resistance is also good.

Claims (2)

[Claims] 1. General formula (1) (Chemical formula 1) [In the formula, aromatic ring A represents a phenyl group which may have a substituent, and aromatic ring B represents a phenylene group which may have a substituent. R ₁ and R ₂ may be the same or different from each other and represent a hydrogen atom, an alkyl group which may have a substituent, or an allyl group. ] A dye for post-dyeing type color toner represented by the following formula. 2. A color toner dyed with at least one of the dyes represented by the general formula (1) according to claim 1.