JPS61110157A - Toner for electrostatic charge image development - Google Patents

Abstract

PURPOSE:To improve separability from a resin component and to improve thermal stability by compounding the thiourea deriv. expressed by the specific chemical formula as an electric charge controlling agent with a resin component thereby preparing a toner for electrostatic charge image development. CONSTITUTION:The thiourea deriv. expressed by the formula (R1, R2, R3, R4 denote hydrogen an alkyl group 1-6C and phenyl group) is compounded as the charge controlling agent at about 0.1-10pts.wt.with 100pts.wt. resin such as styrene resin, styrene-acrylic resin or styprene-butadiene resin by which the toner for electrostatic charge image development is prepd. The embodiment of the thiourea deriv. expressed by the formula includes thiourea, dimethylthiourea, phenylthiourea, 1,1-diphenylthiourea, etc. A coloring agent such as benzidine yellow or quinacridone is adequately used in the case of a color toner.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel dry negatively charged toner for developing electrostatic latent images in electrophotography, electrostatic recording, electrostatic printing, etc.
It is related to.

Originally, an electrostatic latent image can be developed and visualized by adhering toner due to its electrostatic attraction, but as a developer for this electrostatic latent image, other than liquid developer can be used. Powder developers are widely used.

This powder developer is a natural resin or synthetic resin with a coloring agent,
A two-component developer consisting of a mixture of a toner with an average particle size of 15μ in which a charge control agent, a fluidizing agent, etc. are dispersed, and a carrier of 100 to 20 QJI Otori iron powder ferrite powder, and a natural resin or synthetic resin. Coloring agents, charge control agents, fluidizing agents,
It can be roughly divided into one-component developers made of magnetic materials.

A two-component developer achieves development by adhering charged toner to an electrostatic latent image through friction with a carrier1.As a one-component developer, conventionally, it has been used instead of a carrier. A brush-like, plate-like brush with a similar function to this:! A toner that is charged by friction with JW5 material is known, and recently, a toner that is charged by mutual friction with magnetic fine powder by keeping magnetic fine powder in a dispersed state has been known. Became. These developing toners are kept positively or negatively charged depending on the polarity of the electrostatic latent image to be developed.

In order to keep the toner charged, it has been proposed to utilize the triboelectricity of the resin, which is the main component of the toner, but this method has a small charge on the toner and a high solid surface resistance value. , the resulting image is likely to be foggy and unclear. Therefore, in order to impart the desired triboelectric charging properties to the toner, it has been attempted to add charge-imparting dyes, # materials, and even charge control agents, and these techniques are widely used in this technical field today. In the case of imparting a positive charge to the toner, there is a nigrosine-based oil-soluble dye shown in Japanese Patent Publication No. 41-2427, etc., and in the case of imparting a negative charge, there is There are metal-containing complex salt dyes as shown in Japanese Patent No. 26478 and the like.

However, dyes and pigments used as charge control agents have complex structures and lack stability, and are susceptible to decomposition or change due to mechanical friction and impact, poor temperature and humidity conditions, electrical impact, light irradiation, etc. charge controllability is likely to be lost. One essential flaw is that since it is a colored substance, it violates the requirement that toners with a specific hue require a charge control agent that can be matted to be colorless or substantially colorless. .

Recently, Japanese Patent Application Laid-open No. 5
3-127726, JP 57-104940, JP 57-111541, JP 111157-124
Although various gold-g complex compounds are disclosed in Japanese Patent Application No. 357, etc., these complex compounds cannot avoid being slightly colored.

The present inventors have found that it has good dispersibility with the resin component, and
As a result of intensive research on compound Iζ, which has thermal stability up to a temperature that is sufficient to form s-melted meat, is a colorless substance, and can impart a negative charge to toner without containing any metal.
General formula (wherein R1, R2, R3 and R6 are hydrogen,
Indicates an alkyl group (01-C6) or a phenyl group which may have a t substituent. Also, R work, R2, R3 and R4
may be the same or different. ) It was discovered that the thiourea derivative represented by ' is particularly excellent, and the present invention was completed.

Specific examples of the thiourea 5ti4 conductor according to the present invention include thiourea, dimethylthiourea, diethylthiourea, phenylthiourea, 1.1-diphenylthiourea, 1.3
-diphenylthiourea91.3-ditolylthiourea, 1
-Ethyl-3-p-tolylthiourea, 1-yneamyl-
3-p-Tolylthiourea, 1-(3-nitro7enyl)
-3-p-tolylthiuria.

Incidentally, the compound represented by the general formula tIl added to the toner component is added in an amount of 0.1 to 1 to 100 parts by weight of the resin.
It is added in an amount of 0 parts by weight, preferably 0.5 to 5 parts by weight.

In addition to the compound represented by the above general formula (11), the toner of the present invention is made of styrene resin, styrene-acrylic resin, etc. , styrene-butadiene resin, epoxy resin, polyester resin, paraffin wax, etc., or a mixture of several of them.Also, as the coloring agent, many known dyes and pigments can be used, but color copying Examples of particularly excellent toners include benzidine yellow, quinacridone, copper phthalocyanine blue, and copper phthalocyanine green.

The toner of the present invention is mixed with a carrier to provide a two-component developer, but it can of course also be used as a one-component developer.

Hereinafter, the present invention will be explained in detail with reference to Examples.

In addition, in the examples, parts by weight are abbreviated as parts.

Example 1 Styrene-n-butyl methacrylate copolymer resin (65
/35) ...... 100 parts carbon black ■・16 parts 1.1-diphenylthiourea φ@ψ・・2 parts Premix the upper metal parts uniformly in a ball mill to prepare a premix 0 Next, the mixture was melted and mixed with a heated roll, cooled, coarsely ground using a vibration mill, and further finely ground using an air jet mill. The obtained fine powder was classified to obtain a black toner having a particle size of 10 to 20 μm.

A developer was prepared by mixing 97 parts of iron powder carrier (Hon Tetsuko Co., 'x EF Ma 200/300) with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -28.3 μO/g. When a toner image was formed using this developer using a magnetic brush development method on a commercially available toner drum, a clear black image without capri was obtained, and even after repeated use over a long period of time (10,000 sheets), It was possible to obtain a copied image with no change. Example 2 Polyester resin 100 parts (manufactured by Kao Soap Co., Ltd., Mu'l'R-2010) Blue dye
Part 2 (Orient Chemical Industry Co., Ltd. $1.
Valifast Blue 2606) Blue pigment (copper phthalocyanine) 3 parts 1.3-diphenylthiourea φ.@0 2 parts The above-mentioned material was treated in the same manner as in Example 1 to produce a blue toner ffl.

A developer was prepared by mixing 97 parts of iron powder carrier with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -32, lxO/g. When this developer was copied in the same manner as in Example 1, a clear blue image with no capri was obtained, and even after repeated use over a long period of time (10,000 sheets), a copied image remained unchanged. I was able to do it.

Example 3 Epoxy resin...100 parts (manufactured by Shell Chemical Co., Ltd., Epicoat 1oo4) Blue dye
...3 parts (manufactured by Orient Chemical Industry Co., Ltd.,
7alifast Blue 2606) Blue *fee(
jl phthalocyanine)...3 parts 1-ethyl-3-
p-Tolylthiourea...■@3 parts Upper part The above animal was treated in the same manner as in Example 1 to prepare a blue toner.

A developer was prepared by mixing 97 parts of iron powder carrier with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -30.1 μO/g. When this developer was copied in the same manner as in Example 1, a clear blue image with no capri was obtained, and even after repeated use over a long period of time (10,000 sheets), it was possible to obtain a copied image with no change. done.

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. Indicates a phenyl group. Also, R_1, R_2, R_3
and R_4 may be the same or different. ) A toner for developing an electrostatic image, comprising a thiourea derivative represented by the following formula as a charge control agent. 2. The thiourea derivative is 0 per 100 parts by weight of the resin.
．． The toner for developing an electrostatic image according to claim 1, wherein the amount is 5 to 5 parts by weight.