JPS6194060A - Color toner - Google Patents

Abstract

PURPOSE:To improve the triboelectrifiability and the color developability of a toner and to prevent the scattering of it by incorporating a cross-linked aromatic carboxylic acid resin and a copper phthalocyanine in a binary toner composed essentially of the colorant and a wax or the like. CONSTITUTION:The color toner is composed of the copper phthalocyanine to be used as the colorant, and paraffin, and a styrene resin contg. cross-linked acid component obtained by polymerizing and cross-linking a styrene type monomer, such as styrene or methylstyrene, acrylate type monomer, such as methyl acrylate of ethyl methacrylate, an acid component, such as acrylic acid or cinnamic acid, and a cross-linking agent, such as aromatic divinyl compd. diethyl carboxylic acid. The use of such a styrene resin permits the copper phthalocyanine to be enhanced in dispersibility, the color toner to be improved in triboelectrifiability and image quality to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a color toner for two-component development in electrophotography.

[Technical background of the invention and its problems]

Generally, as shown in the drawings, in an electrophotographic apparatus, a charging device 2. Exposure device 3, development device 4. Transfer device 5, peeling device 6, cleaning device 7. The static eliminators 8 are sequentially arranged, and the fixing device 11 is arranged at the end of the paper transport path IO, which is formed to pass through the image transfer section 9 between the photoconductor l and the transfer device 5. .

Then, a charging device 2 places a potential on the photoreceptor I using an optical semiconductor in advance by corona discharge or the like.

Next, the exposure device 3 forms an image of the document through an optical lens, or by applying an optical signal from a laser beam, a potential drop corresponding to the irradiated light is caused, and a so-called static state is created. Forms an electrolatent image.

Next, the developing device t14 brings the charged developer (toner) into contact with or in close proximity to create an electrostatic latent image.The developing side a of the throat is placed on the photoreceptor according to the strength of the electric field! The latent image is visualized by being attracted to the top.

Further, the transfer device 5 transfers the developer a on the photoreceptor I onto the paper P by the force of an electric field 1~, and then the peeling device 6 peels the paper P from the photoreceptor I, and the fixing device 11 Here, energy such as heat, pressure, and light is applied to fix the material.

As described above, a copied image can be obtained through the processes of charging, exposure, development, transfer, and fixing.

The surface of the photoreceptor I after the developer image has been transferred is cleaned and neutralized by a cleaning device 7 and a static eliminating device 8 in preparation for the next copying. In these processes, toner and developer greatly influence development, transfer, fixing, and cleaning, and occupy an important position in electrophotography. As a developing method, a cascade developing method, a magnetic brush method, a powder cloud method, a fur brush developing method, a jumping developing method, etc. are known. Broadly speaking, there are methods that use magnetic force to transport the developer to the supplied part of the photoreceptor and methods that do not. Among the methods that use magnetic force, there are methods that use magnetic force to transport the developer to the supplied part of the photoreceptor. There are two methods: one method is to mix the toner with a magnetic carrier such as iron powder or ferrite powder. In the case of the magnetic component method, a clear color image cannot be obtained because a large amount of magnetic powder such as iron oxide powder is mixed in. In the magnetic two-component system, the developer is made by kneading resin, colored pigments, etc., pulverizing them and classifying them into particles of about 1 to 5 to 30 μm]. Consists of carriers. Toner and carrier are triboelectrically charged by mixing and stirring [7, each has a quasi-ambiguous atmosphere of positive and negative opposites. band'!
The amount of ta'm is roughly determined by 1) the difference in the triboelectric charging system between the toner and the carrier, and 11) the electrical resistance of the toner or carrier. This is one of the most important things in design. For example, the amount of charge is 1)ll! Il image density, 11)
Fogging, IL+)) toner scattering, I This affects transfer efficiency, etc., and if the charge amount is too low, the mirror image force (■square of the charge amount) that binds the toner and carrier becomes weak, resulting in increased fogging and toner scattering. On the other hand, if the amount of charge is too high, the density of one image will decrease and the transfer efficiency will decrease. Regarding fog 1, toner scattering, etc., it is also necessary to pay attention to how the amount of charge increases when the toner and carrier are mixed and rubbed. The amount of charge must always be controlled within a certain appropriate range, but as a practical matter, it gradually changes as continuous copying continues. The amount of charge is generally controlled by improving the toner. Although it may be controlled by the carrier, there are limitations due to the relatively limited materials, the structure of the developing device, and the image quality.
In particular, this is not common because the electrical resistance is predetermined from the viewpoint of gradation reproducibility. In the case of black monochrome toner, the method of controlling the amount of charge is relatively well known.

For example, the triboelectric charging series of the toner can be changed by adding a certain type of dye, and the electrical resistance of the toner can be adjusted by changing the type and amount of carbon black in the colorant [71]. It is also possible to control. However, most of these are colored and cannot be used to obtain color toners with vivid colors.

Furthermore, in the case of colored pigments used in color toners, particularly azo organic pigments, electrical resistance is generally higher than that of carbon black, and therefore toner resistance and developer resistance become higher. Therefore, a phenomenon occurs in which the frictional charges generated as the developer is stirred are difficult to dissipate and the amount of charges increases, resulting in a decrease in image density. Therefore, as copies are made, the electrical characteristics change and the image quality changes.
Additionally, along with this, the developer deteriorates due to spent toner and the like, and the optical system becomes dirty due to toner scattering, etc., and the life performance is generally quite low. Furthermore, since color pigments have poor dispersibility in resin, the liberated pigments, which cause non-uniform charging, tend to have adverse effects such as contaminating carrier particles and the surface of the photoreceptor. Poor dispersibility is often the cause of poor color development and skin tone.

Furthermore, there are problems with color tone reproducibility, heat resistance, light resistance, etc., and it is difficult to maintain image quality.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its purpose is to provide 1iIIIi quality that has uniform electrical characteristics, poor developer quality, little toner scattering, good color development, and less fading. The aim is to provide stable color toner.

[Summary of the invention]

In order to achieve the above object, the present invention uses a cross-linked resin with an acid value to form a colorant (pigment).
If the above problems are solved, the dispersibility is good and the above problems are solved.

A feature of the present invention is that in a two-component developing toner whose main components are a colorant resin and a wax, the resin is polymerized together with a crosslinking agent during production, and at the same time a crosslinked polymer is created and an aromatic carbonaceous By reacting with acid, it becomes a crosslinked resin with an acid value.

The above-mentioned crosslinked resin having an acid value facilitates the dispersion of colored pigments, particularly azo pigments commonly used in color toners, and phthalocyanine pigments into resins, particularly styrene resins. Therefore, the surface of the carrier is less likely to be contaminated with pigment, and deterioration of the developer can be prevented. This makes it possible to provide color toners that do not adversely affect moisture resistance.

[Embodiments of the invention]

An embodiment of the present invention will be described below. Copper phthalocyanine, which is a blue pigment, has a positive charge due to its structure, and toner containing copper phthalocyanine has a low charge amount and is likely to cause fogging, toner scattering, etc. [1. Therefore, by containing electron-attracting -COOH, it is possible to maintain a good charge amount.

Further, depending on the content of --COOH, the amount of charge can be adjusted to the 5T node, and a range of about 01 to 5.0 mol % exhibits good charging stability.

Another advantage of the crosslinked type is that by improving the dispersion of the pigment, the carrier surface is less likely to be contaminated with the pigment, less likely to cause spent, and whitening with better image quality can be achieved.

Examples of the styrene monomer for the above resin include styrene, methylstyrene, ethylstyrene, butylstyrene, dimethylstyrene, chlorostyrene, and dichlorostyrene.

The acrylic monomers include methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, 2-ethylexyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate.

Further, examples of the acid component include acrylic acid, cinnamic acid, protonic acid, anhydrous protonic acid, and methacrylic acid.

In addition, crosslinking agents and 1- are mainly compounds with two or more polymerizable double bonds, and all divinyl compounds such as aromatic divinyl compounds and diethyl carboxylic acid esters and compounds with three or more vinyl groups are used alone. , or added as a mixture.

(1 row of K bodies 1) Partially cross-linked styrene-acrylic copolymer resin.

Almatex After premixing 6.0 parts by weight (manufactured by Dainichiseika), the mixture was kneaded in a pressure kneader for 30 minutes, cooled, coarsely crushed, and then finely crushed to obtain an average particle size of 12.0 parts by weight. (A blue toner of 1 μm was obtained. This was transferred to the ferrite carrier TFC-38 (TDK
) and mix it 1° to make a developer, then use RheoDry BD781.
1 (next summer), we tested 10,000 sheets of 1. Even after this, there was no decrease in image density or blurring. Further, even after being left in an environment of 30° C. and 85% RH for 24 hours, no increase in fogging or toner scattering was observed.

(Comparative Example 1) Styrene-butadiene copolymer resin Nipole 2007J
(Product name: manufactured by Nippon Zeon, acid film does not mix) 90 parts by weight,
Polypropylene Waxheimer 550P (product name; manufactured by Sanyo Kasei) 4 military cap, blue pigment phthalocyanine blue 4
920G (trade name; manufactured by Dainichiseika) in the same manner as in Example 1.
7. When a blue toner was prepared and tested using BD 7811 (trade name: next summer), the band iJi amount decreased from 1 to 1 after passing 5,000 sheets of paper, and fogging toner scattering was observed.

〔Effect of the invention〕

Based on the above explanations 1 to 1, according to the present invention, a color toner with good dispersibility and stable chargeability can be obtained, and image density decreases and fog increases.

It is possible to provide stable image quality with no toner scattering or the like.

[Brief explanation of drawings]

The drawing is an explanatory diagram of the basic configuration of an electrophotographic apparatus. a...Developer.

Claims (2)

[Claims] (1) a styrene monomer and a monomer selected from acrylic acid, cinnamic acid, protonic acid, protonic acid anhydride, and methacrylic acid; an acrylic monomer and a molecular weight regulator;
A color toner characterized by using a resin containing a crosslinking agent as a copolymerization component and copper phthalocyanine as a coloring agent. (2) Styrene monomer 60-90 mol%, monomer selected from acrylic acid, cinnamic acid, protonic acid, protonic acid anhydride, methacrylic acid 0.1-5 mol%, and acrylic monomer 10-40 mol%. A color toner according to claim 1.