JPH07209912A - Dye and composition for magenta color toner - Google Patents

Abstract

PURPOSE:To enhance melt mixability, to stabilize image density obtained by successive copying by repeating development, and to improve lightfastness by using the dye for a specified magenta color toner. CONSTITUTION:This dye and composition for the magenta color toner contains at least one of dye represented by the formula, in which R is alkyl, alkoxyalkyl, aralkyl, or an optionally substituted containing >=1 N, 0, or S atoms. The color toner containing this dye can be obtained by adding a suitable amount of this dye into a binder resin, and a negatively chargeable color toner is obtained by this method. As the carrier to be used together with this toner, a magnetic material, such as iron, cobalt, or nickel, or each alloy, or each mixture coated on the surface can be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to color toners, and more particularly to dyes and color toners for negatively charged color toners for electrostatic charge development.

[0002]

2. Description of the Related Art Conventionally, as a method of developing an electric latent image with color toner to form a visible image, an electrostatic printing method or an electrophotographic method is well known. Generally, a photoconductive substance is used to form an electrical latent image on a photoconductive photoconductor by various means, and then the latent image is developed with toner to obtain a visible image, or According to the method, a powder image is transferred onto paper or the like and then fixed by heating, pressurizing, solvent vapor or the like to obtain a visible image.

In order to obtain a multicolor image in color, the original is exposed using a color separation filter, and the above steps are performed in yellow.
A plurality of color toners such as magenta and cyan are used to form a color image.

As a toner for developing an electric latent image, particles in which a colorant is dispersed in a binder resin such as polystyrene and pulverized to about 0.1 to 50 .mu. Are conventionally used. This color toner is usually glass beads,
It is mixed with a carrier material such as iron powder and used for developing an electrical latent image.

These color toners are required to have various physical and chemical characteristics. However, many known color toners have the following drawbacks. (1) The triboelectric properties of color toners are adversely affected by temperature changes. (2) Collision between color toner particles and carrier particles due to repeated development for continuous use and change in density due to mutual deterioration of those particles and photosensitive plate, or deterioration of copy quality due to increase in background density occurs. (3) When an attempt is made to increase the density of a copied image by increasing the amount of color toner adhered to the surface of the photosensitive plate having a latent image, the background density is usually increased and a so-called fog phenomenon occurs. (4) Insufficient transparency required for multicolor overlapping. (5) The melt miscibility of the dye in the toner with the toner is poor. (6) The spectral reflection characteristic for accurately reproducing the original is poor. (7) Since it has solubility in the release agent (silicon oil), it stains the silicone oil and consequently the copy image.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a dye for color toner and a color toner composition which do not have the above-mentioned drawbacks.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the problems of the above color toners, the present inventors have found that the dye represented by the general formula (1) is excellent in melt mixing. The present invention has been completed by finding that a color toner composition having the property of containing this dye has a stable magenta color in the image density obtained by continuous copying by repeated development, and has good light fastness. did. That is, the present invention provides the following general formula (1)

[0008]

[Chemical 2] [In the formula, R represents an alkyl group, an alkoxyalkyl group, an aralkyl group, or a substituted or unsubstituted heterocyclic group containing at least one nitrogen atom, oxygen atom or sulfur atom. ] A magenta color toner composition containing at least one kind of the dye for magenta color toner represented by the above formula and the dye represented by the general formula (1).

The present invention will be described in detail below. In the compound of the general formula (1) in the present invention, R represents an alkyl group, an alkoxyalkyl group, an aralkyl group, or a substituted or unsubstituted heterocyclic group containing at least one nitrogen atom, oxygen atom or sulfur atom. Examples of the alkyl group include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl,
Examples include n-pentyl, n-hexyl, n-heptyl, n-octyl and the like. As an alkoxyalkyl group,
Methoxyethyl, ethoxyethyl, n-propoxyethyl, iso-propoxyethyl, n-butoxyethyl,
Examples thereof include iso-butoxyethyl, tert-butoxyethyl and the like. Examples of the aralkyl group include benzyl and phenethyl. As the heterocyclic group containing at least one nitrogen atom, oxygen atom or sulfur atom, thiazole,
Examples thereof include benzothiazole, thiadiazole, thiazoline, oxazole, benzoxazole, oxadiazole, oxazoline, imidazole, benzimidazole, imidazoline, pyridine and pyrimidine. When the heterocyclic group has a substituent, examples of the substituent include an alkyl group such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and tert-butyl, a hydroxy group, Alkylcarboxy groups such as methylcarboxy, ethylcarboxy, n-propylcarboxy, iso-propylcarboxy, n-butylcarboxy, iso-butylcarboxy, tert-butylcarboxy, amino groups, methylcarbonylamino, ethylcarbonylamino, n-propyl Examples thereof include alkylcarbonylamino groups such as carbonylamino, iso-propylcarbonylamino, n-butylcarbonylamino, iso-butylcarbonylamino, tert-butylcarbonylamino and the like.

The dye of the present invention represented by the general formula (1) can be produced by a conventional method, for example, by reacting an anthraquinone derivative with a mercaptan derivative as shown below.

[0011]

[Chemical 3] [In the formula, X represents a chlorine atom or a bromine atom, and R represents the same meaning as in formula (1). These dyes exhibit a magenta color with a vivid blue color, and can be used alone or in combination with other dyes as a coloring dye for a magenta color toner.

As a method for producing a color toner using the dye of the present invention, a binder resin may be contained in an appropriate amount of the compound of the formula (1), whereby a negatively charged color toner can be obtained. it can.

The addition amount of the magenta color dye applied to the color toner composition of the present invention is determined by the chargeability of the binder resin, the chargeability of the colorant or additive which is supplementarily added, and the dye and the binder resin. Since it is determined by the compatibility with or the dispersion method and the like, it is not limited in a uniform manner, but generally speaking, it may be used in the range of about 0.1 to 10% by weight with respect to the binder resin. desirable.

As the binder resin, all known resins can be used. For example, a homopolymer of styrene such as polyethylene, poly-p-chlorostyrene, polyvinyltoluene and the like, or a substitution product thereof, or a styrene-vinylnaphthalene copolymer. , Styrene-methyl acrylate copolymer, styrene-
Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer,
Styrene-methylmethacrylate copolymer, styrene-ethylmethacrylate copolymer, styrene-butylmethacrylate copolymer, styrene-α-chloromethylmethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinylmethyl Ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid Copolymers, styrene copolymers such as styrene-maleic acid ester copolymers, 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 the like can be used alone or in combination.

As the carrier agent as the developer, for example, magnetic substances such as iron, cobalt and nickel, their alloys and mixtures, or those whose surfaces are coated can be used.

[0016]

The present invention will be described in more detail with reference to the following examples. "Parts" in the examples indicate parts by weight. Incidentally, Examples 1 to 12
The light resistance of Comparative Examples 1 and 2 was evaluated by a blue scale after irradiation with a fade meter (carbon arc lamp) at 63 ° C. for 60 hours, and was determined according to JIS standard (L 0842-197).
Expressed by the series according to 1).

Example 1 10 parts of 1-amino-2-bromo-4-hydroxyanthraquinone and 5.1 parts of potassium carbonate were added to 70 parts of sulfolane, and the temperature was raised to 70 ° C. under aeration of nitrogen. Next, 4.1 parts of 2-mercaptopyridine was added, and the mixture was reacted at 70 ° C. for 1 hour. After completion of the reaction, the mixture was cooled to room temperature, 30 parts of methanol was added, filtered, washed with water, dried and purified by column chromatography to obtain a compound of the following formula (2) 8.
I got 0 copies.

[Chemical 4]

5 parts of this compound, a resin for toner [styrene-acrylic acid ester copolymer; trade name Heimer TB
-1000F (manufactured by Sanyo Kasei)] 95 parts by ball mill, pulverize, heat to 150 ° C. to melt and mix, cool and coarsely pulverize with hammer mill, then finely pulverize with air jet type fine pulverizer did. Further classify 1-2
0 micro was selected as a toner. To 10 parts of this toner, carrier iron powder (trade name EFV250 / 40
0: made by Nippon Iron Powder) 900 parts were uniformly mixed to obtain a developer. When this developer was used to perform copying with a dry plain paper electrophotographic copying machine [trade name: NP-5000; manufactured by Canon Inc.], a clear magenta image free from fog was obtained. Further, since the compound represented by the formula (2) has a low solubility in silicone oil, the contamination of the silicone oil is very small, the contamination of the copied image is not recognized, and the light resistance of the duplicate is 6th grade. It was good.

Examples 2 to 12 Using the dyes having the structures shown in Table 1, color toner compositions were obtained in the same manner as in Example 1. Further, a developer was prepared from these toners and copying was carried out in the same manner as in Example 1. As a result, a clear magenta image free from fog was obtained. Further, no contamination of the copied image was observed, and the light resistance of the copies was 6 as shown in Table 1 and good.

[0020]

[Table 1]

[0021]

[Table 2]

Comparative Example 1 The dye for the magenta color toner in the toner composition of Example 1 is represented by the following formula (3).

[Chemical 5] A developer was prepared in the same manner as in Example 1 except that 5 parts of the compound shown in was used and copying was carried out. As a result, the copy had a poor light resistance of grade 3, and was poor.

Comparative Example 2 The dye for the magenta color toner in the toner composition of Example 1 is represented by the following formula (4).

[Chemical 6] A developer was prepared in the same manner as in Example 1 except for replacing 5 parts of the compound represented by, and copying was carried out. As a result, a magenta color was obtained, but the compatibility with the toner resin was poor and fog was observed. Phenomenon occurred, and the light resistance of the copied product was 3 grade and poor.

[0024]

The conventional toner has a poor light resistance of the copy.
Although the toner composition of the present invention had problems such as occurrence of fog phenomenon and poor melt-miscibility, the toner composition of the present invention has excellent melt-miscibility, and the image density obtained by continuous copying due to repeated phenomena is stable. In addition, it has good light fastness and is extremely valuable in practical use.

Claims (2)

[Claims] 1. The following general formula (1): [In the formula, R represents an alkyl group, an alkoxyalkyl group, an aralkyl group, or a substituted or unsubstituted heterocyclic group containing at least one nitrogen atom, oxygen atom or sulfur atom. ] A dye for magenta color toner represented by the following formula. 2. A magenta color toner composition containing at least one kind of the dye represented by the general formula (1) according to claim 1.