JPH0296183A - Electrophotographic magenta toner - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic magenta toner having high chargeability, superior spectral reflection characteristics, and high color miscibility by incorporating a specified compd. as charge controlling agent and a quinacridone pigment as coloring pigment into a polyester or acrylic resin. CONSTITUTION:A compd. classified into C.I. Solvent Red 84 as charge controlling agent and a quinacridone pigment as coloring pigment are incorporated into a polyester or acrylic resin. The materials are melted and kneaded, and granulated. Thus, a distribution of the charge controlling agent component in individual fine toner particles is made uniform, causing no unevenness of charge. Thus, uniform chargeability, superior spectral reflection characteristics, and high color miscibility, are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a color toner for electrophotography, and particularly to a magenta toner for electrophotography that provides a clear colored image.

(Prior Art) Conventionally, in a copying machine using an electrophotographic method, an electrostatic latent image formed on a photoreceptor having a photosensitive layer containing an inorganic or organic photoconductive substance is visualized by a dry developing method. Various powder toners containing colorants, binder resins, etc. are used.

In the electrophotographic method, an electrostatic latent image formed on the photoreceptor by charging and exposure to light is developed with the toner, and a toner image formed corresponding to the electrostatic latent image is transferred to a support such as transfer paper. At the same time as the transfer, the toner image is fixed on the support by a fixing means such as a heating roller or a pressure roller, thereby making the electrostatic latent image visible. Further, after the toner image is transferred to the support, the residual toner on the photoreceptor is removed by a cleaning blade in order to clean the toner remaining on the photoreceptor.

Currently, a black toner whose main components are a black pigment and a fixing binder resin is generally used as the toner.
Furthermore, various color toners are manufactured by using chromatic pigments as pigments. The color toner, like the black toner, must have excellent charging properties, and a method that utilizes frictional charging of a resin, which is a component of the toner, has been known as a method for imparting an electric charge to the toner during the development. ing. However, in such a method, since the amount of charge on the toner is small, C,! , Solvent Red 177 ('lI11865
4), 1-(2-hydroxy-3,5-dinitrophenylazo)-3-phenylcarbamoyl-2-naphthol l: from dyes and pigments such as type 2 chromium complex salts, naphthenic acid metal salts and fatty acid metal soaps. A toner has been proposed in which a charge control agent consisting of the following is added to a toner as an additive that imparts chargeability.

On the other hand, as properties specific to the color toner, it is necessary to have excellent spectral reflection characteristics and color mixing properties, and conventionally C.
61, Pigment-Red48 and C.61. I. Pi
Toner containing gment-Red81 (Japanese Unexamined Patent Application Publication No. 62
As shown in Japanese Patent Publication No. 49359), various types of materials using limited materials such as coloring agents have been proposed.

(Problems to be Solved by the Invention) However, many of the dyes and pigments conventionally used as charge control agents have low compatibility with resins, and all require dispersion in a binder resin. There were problems with the dispersion method, stability of the dispersion, etc.

That is, it is difficult to uniformly disperse insoluble pigments and dyes with low compatibility in the binder resin, which complicates the dispersion process. Moreover, due to the low compatibility with the resin, the components in the individual toner particles produced become non-uniform, and the charge imparted to the toner varies. Large or small particles may be formed, and in some cases, fine particles consisting only of dyes or pigments may also be present.

As a result, the image obtained by development may become foggy and unclear, or even if it shows good developability at the beginning of use, the developing ability may deteriorate with continued use, or the copying may become difficult due to increased toner scattering. There were problems such as contamination inside the aircraft.

Furthermore, since pigments are aggregates, differences in the conditions of the pigment manufacturing process greatly affect the characteristics of the manufactured toner, and it is extremely difficult to control the physical properties of pigments to solve this problem.

In addition, in color toners, the color of the charge control agent itself greatly affects the color mixing properties, spectral reflection characteristics, etc. of the toner even when the amount contained in the toner is small. Therefore, there is a continuing need for a suitable combination of color pigments and charge control agents, which are constituent components of color toners, with respect to the hue of the toner.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of conventional electrophotographic toners, and to provide electrophotographic toners that are uniformly charged, have excellent charging ability, and have good spectral reflection characteristics and color mixing properties. The aim is to provide magenta toner.

(Means and effects for solving the problems) The present invention has the following features:
By composing a magenta toner for electrophotography containing a compound classified as C, I, and Solvent Red 84 as a charge control agent and a quinacridone pigment as a coloring pigment in a polyester resin or an acrylic resin, the above 1. achieved.

As a result of intensive research, the present inventors found that the above C. I. It was discovered that an oil-soluble dye classified as Solvent Red 84 dissolves extremely well in polyester resin or acrylic resin, and a compound classified as a quinacridone pigment has extremely good spectral reflection properties as magenta. It has been found that this method gives a vivid magenta color with a high degree of color.

Furthermore, as a result of intensive research, the above-mentioned C0I, Solvent Red 84, which dissolves extremely well in polyester resin or acrylic resin as a component of electrophotographic toner
It has been discovered that a vivid magenta toner with particularly excellent color mixing properties can be obtained by combining a compound classified as a quinacridone pigment.

Therefore, since the magenta toner for electrophotography of the present invention uses the above-mentioned components, the charge control agent component in each fine toner particle produced by melt-kneading and granulating the same becomes uniform. As a result, it is possible to obtain a magenta toner for electrophotography which has extremely uniform charging properties without uneven charging, and also has good spectral reflectivity and color mixing properties.

Furthermore, even when the humidity is changed, the amount of moisture absorbed by this C, I, Solvent Red 84 does not change much, and the relationship between the moisture absorption conditions and the moisture content is as shown in the following C. I. Solvent Red 84 Handling - "" E - Water shearing rate 1M) 20°C 160% RH 1,0392 35°C 85% RH 1,8339, and the moisture content in the dye has very little dependence on humidity. I understand that. This means that the toner using the above-mentioned oil-soluble dye has little variation in moisture content that affects the properties of the toner, regardless of changes in humidity, temperature, etc. during standby, and in other words, this toner does not tend to deteriorate over time. This means that stable development characteristics can be obtained.

Furthermore, the charge amount of C01, Solvent Red 84, when measured by blow-off after mixing with a ferrite carrier, is on the order of about -34.7 μc/g, and the above C9], Solvent Red 84 is on the order of about -34.7 μc/g. It can be seen that it functions satisfactorily.

(Preferred Embodiment of the Invention) Any polyester resin can be used as the binder resin in the present invention, but from the viewpoint of non-offset property and fixing property, the following - Saito, CH.

(In the formula, R is an ethylene group or a propylene group, m
and n is a positive integer) and a polyhydric carboxylic acid, its acid anhydride, or its derivative as an acid component. .

The diol component represented by the above-mentioned shipman includes polyoxypropylene-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane, and polyoxypropylene-2,2-bis(4-hydroxyphenyl)propane.
Examples include polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane.

Carboxylic acid components include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sepacic acid, malonic acid, Riluic acid, 1,2.4 benzenetricarboxylic acid, 1.2.5 benzenetricarboxylic acid, 1.
2. 4 cyclohexanetricarboxylic acid, 2,5.7
naphthalenetricarboxylic acid, 1,2.4 naphthalenetricarboxylic acid, 1,2.5 hexanetricarboxylic acid, l,
2.4-butanetricarboxylic acid, 1,3-dicarboxy-
2-methylcarboxypropane, 1,3-dicarboxy-2-methyl-2-methylcarboxypropane tetra(
Methylenecarboxy)methane, 1,2,7.8 octane tetracarboxylic acid, embol trimer and acid anhydrides thereof can be mentioned.

This polyester resin is produced by condensation polymerization of the diol component and polyhydric carboxylic acid component,
At this time, the number of carboxyl groups in the carboxylic acid component is 1.2 to 0.0 relative to the number of hydroxyl groups in the diol component.
8, especially 1. 1 to 0.9, and as a catalyst, tin oxide, zinc oxide, titanium oxide,
Dibutyltin oxide, dibutyltin diurarate, etc. are used. Furthermore, in addition to the etherified bisphenol shown in the above-mentioned ``Shipin'', other diol components such as ethylene glycol and bisphenol A can be used in combination within a range of 10 mol%.

Further, any acrylic resin can be used as the binder resin in the present invention, but from the viewpoint of transparency, which is effective in color toners for electrophotography, etc.
An example is a methacrylate-acrylate copolymer.

This methacrylate-acrylate copolymer includes methyl methacrylate (MMA), ethyl methacrylate,
The main monomer components are methacrylic acid esters such as butyl methacrylate and acrylic acid esters such as methyl acrylate, ethyl acrylate, and butyl acrylate, and optionally acrylic acid, methacrylic acid, crotonic acid, fumaric acid, and maleic anhydride. It is a copolymer containing a small amount of ethylenically unsaturated carboxylic acid such as itaconic acid or its anhydride as a copolymerization component.

The copolymerization ratio of methacrylate and acrylate can be varied within a range that satisfies transparency, refractive index, melting properties, melt leveling properties, etc., but generally the former is 60%
95% by weight, especially 70% to 90% by weight, the latter being 5% by weight.
A range of from 10 to 30% by weight is preferred, particularly from 10 to 30% by weight. As the methacrylate, methyl methacrylate (MMA) is optimal from the viewpoint of economy and transparency, and as the acrylate, ethyl acrylate (EA) is optimal from the viewpoint of melt leveling properties.

The quinacridone pigment that is a component of the present invention includes:
Any one can be used, but for example, the following - Shipman (wherein R, to R8 are the same or different and hydrogen atoms,
quinacridone pigments represented by halogen atoms, alkyl groups, alkoxy groups, allyl groups), specifically unsubstituted quinacridone, 2.9 dichloroquinacridone, 3.1
0 dichloroquinacridone, 4.11 dichloroquinacridone, 2,9 dimethylquinacridone, 3,10 dimethylquinacridone, 4.11 dimethylquinacridone, 2.9 dimethyl-1-xyquinacridone, 2,4,9,11 tetramethylquinacridone, 1, 2, 4.8, 9.11, hexachlorquinacridone, etc.

The above-mentioned color pigment is used in an amount of 1 to 15 parts by weight per 100 parts by weight of the toner binder resin. If the amount is less than the above range, the color tone of the magenta toner will not be maintained, and if the amount is more than the above range, the chargeability will be seriously affected, which is not preferable.

In the present invention, C is used as a charge control agent together with a color pigment.
．． I. It is preferable to use Solvent Red 84 in an amount of 0.5 to 10% by weight, especially 1 to 5% by weight, based on the binder resin for toner. If it is less than the above range, there is no charge control effect; If the amount exceeds 1, the stability of the toner deteriorates and problems such as carrier contamination occur.

In the electrophotographic toner of the present invention, toner compounding agents known per se can be blended according to known formulations.

The toner is manufactured by blending a predetermined amount of the above-mentioned composition, melting and kneading it in a roll mill, and granulating the mixture. For molding, the above-mentioned kneaded composition is cooled, then coarsely pulverized with a hammer mill, and further finely pulverized with a jet mill. Of course, rapid mechanical stirring may be used to round off irregularly shaped particles. The particle size of the toner particles may be related to resolution, etc., but is generally preferably within the range of 5 to 35 microns.

(Effects of the Invention) The toner of the present invention uses a polyester resin or an acrylic resin as a toner binder resin, and uses C.I. I. By having Solvent Red 84, the charge in the toner is uniformly applied, and it has stable chargeability even after repeated development due to continuous use.Furthermore, by combining quinacridone pigment as a coloring pigment, it has good spectral properties. It has reflective properties and color mixing properties and can maintain clear images.

(Example) Hereinafter, the present invention will be explained in Examples.

100 parts by weight of polyester resin as a binder on the actual thimble 8.5 parts by weight of C9I, Pigment-Red122 (quinacridone pigment) as a coloring agent C1I, Solvent Red 84 (manufactured by Hodogaya Chemical Industries, Ltd.) as a charge control agent , Product name 5PILONYELLOW 3RH)
A mixture of 2 parts by weight of the above toner materials is melt-kneaded, cooled, pulverized, and further classified to produce the toner of the present invention, and further 5 parts by weight of the above toner and a carrier (manufactured by Nippon Tetsuko Co., Ltd., trade name 5FC150) 95 A developer sample was prepared by mixing parts by weight.

Tsumeiban I Example 1 except that MMA+EA copolymer was used as the binder resin in place of the polyester resin used in Example 1.
A developer sample was produced in the same manner.

Northern Captain C0I used in Example 1 as a charge control agent.

Instead of Solvent Red 84 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name 5PILON RED GEH), C.I. I
．． A developer sample was produced in the same manner as in Example 1 except that Solvent Red 135 (trade name: 0PLAS RED339, manufactured by Orient Kagaku Kogyo Co., Ltd.) was used.

Dokan Lieutenant I c and r used in Example 2 as charge control agents.

C01 in place of Solvent Red 84 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name 5PILON RED GEH)
A developer sample was produced in the same manner as in Example 2, except that Solvent Red 135 (manufactured by Orient Chemical Industry Co., Ltd., trade name: PLAS RED339) was used.

, history comparison 1 - C, I, Pigment used in Example 1 as a colorant
-Instead of Red122 (quinacridone pigment), C
．． I. Pigment-Red57 (Azo lake pigment)
A developer sample was produced in the same manner as in Example 1 except that .

C, I, Pig used in Example 2 using Hokkaipan as a coloring agent
ment-Red122 (quinacridone pigment), C.I. I. A developer sample was produced in the same manner as in Example 2 except that Pigment-Red 57 (Azo Lake pigment) was used.

Each developer obtained in the above example was used as a copy aDC manufactured by Sandako Co., Ltd.
-A2L'Nieto i Copied 20,000 sheets continuously. As a result, when the developers of Examples 1 and 2 were used, yellow images with very good spectral reflection characteristics without fog were obtained, and there was almost no image deterioration through 20,000 sheets, and there was almost no toner scattering. I couldn't see it. On the other hand, when the developers of Comparative Examples 1 and 2 were used, significant fogging occurred and clear images could not be obtained. Further, when the developers of Comparative Examples 3 and 4 were used, the color tone was dull and the copy quality was dull.

Table 1 shows the types of dyes and binder resins used in the experiment and the results of measuring their solubility.

Table 1 ○: Dissolves in resin ×: Does not dissolve in resin

Claims (1)

[Claims] C.I. as a charge control agent in polyester resin or acrylic resin. I. A magenta toner for electrophotography characterized by containing a compound classified as Solvent Red 84 and a quinacridone pigment as a coloring pigment.