JPH032301B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a developing powder for electrophotography. Electrophotography generally involves forming an electrostatic latent image on a photoconductor made of a photoconductive substance, developing this image with a powder developer to make it visible, and then fixing it with heat or a solvent. be. As a developer for such electrophotography, a mixture of a fine particle powder called a toner, which is made of a resin and a colorant, and microscopic glass beads or iron powder, called a carrier, is used. The present invention relates to this developing powder called toner. The photoconductor layer can be positively or negatively charged so that exposure under the original produces a positive or negative electrostatic latent image. Therefore, if the negative electrostatic latent image is developed with positively charged developer powder, a positive image matching the original is generated. However, when a positively electrostatic latent image is developed with negatively charged developer powder, the black and white tones are reversed and a negative image of the original, that is, a positive negative image is obtained. As described above, there are two types of developer powder for electrophotography: positively charged developer powder and negatively charged developer powder. Among these, the present invention relates to positively charged developer powder. Generally, developer powder is a fine powder made by mixing synthetic resin with coloring agents such as dyes and pigments. In order to positively charge the developer powder, the dye mixed therein plays an important role not only in coloring but also in its electrostatic properties as a charge control agent. Basic dyes such as nigrosine have been used as positive charge control agents, but the conventionally used dyes such as nigrosine have large variations in charging characteristics between production lots, and when made into toner, It has drawbacks such as poor durability against repeated continuous copying of toner. The present inventors have conducted extensive research to solve the above problems, and have discovered a metal complex compound that has positive charge control properties and good compatibility with resins, and has improved all of the above problems. , led to the invention of an excellent toner. That is, the present invention is based on the following general formula (1) (In the formula, R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and an alkyl group having 2 to 4 carbon atoms.
4 alkoxycarbonyl group, aminosulfonyl group, acylamino group, aminocarbonyl group, alkylaminocarbonyl group having 2 to 4 carbon atoms, alkylsulfonyl group having 1 to 3 carbon atoms, nitro group, cyano group, halogen atom, m is 1, 2, 3 or 4, and when m is 2 or more, R can be different substituents, and Y has 1 to 1 carbon atoms.
4 represents an alkylene group, Z represents a quaternary ammonium group, M represents a chromium atom or a cobalt atom, and X represents an anion. This is an electrophotographic toner containing a 2:1 type metal complex salt compound represented by ) as a charge control agent and a colorant. The dye represented by general formula (1) used in the toner of the present invention is represented by general formula (2). (where R and m are as defined above.)
The diazo component represented by is diazotized by a conventional method, and this diazo compound is expressed by the following general formula (3). (In the formula, Y, X, and Z are as defined above.) By coupling with the azo component represented by (In the formula, R, Y, It can be obtained by treatment with a cobaltization imparting agent or a cobaltization imparting agent. The dye according to the present invention obtained in this way has a positive chargeability and is made of a resin, such as polystyrene,
Monomers of styrene and its substituted products such as polyvinyltoluene, styrene-substituted styrene copolymers,
Styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer,
Dispersed in styrene-acrylonitrile copolymers, polyvinyl chloride, polyethylene, silicone resins, polyesters, polyurethanes, polyamides, epoxy resins, modified rosins, phenolic resins, etc., and further made into fine powders also exhibit positive chargeability. Furthermore, this dye has good compatibility with the resins mentioned above and can be uniformly and finely dispersed in the resin. On the other hand, this dye has extremely low solubility in water, and therefore is not affected by environmental humidity and can maintain stable positive chargeability. The developing powder of the present invention is prepared by melting and blending the dye of formula (1) in a weight ratio of 1 to 50% based on the synthetic resin, solidifying it, and then pulverizing it with a ball mill or other pulverizer, or by adding it to the synthetic resin monomer. It can be produced by adding a polymerization initiator, adding thereto a dye in a weight ratio of 1 to 50% based on the monomer, and polymerizing the mixture while suspending it in water. At this time, other colorants or carbon black may be added as a dye. The developer powder produced in this way provides an amount of charge suitable for developing an electrostatic image through friction with the carrier, and the amount of charge remains constant even after repeated development, and the charge distribution is uniform. held constant. Therefore, images developed using this developing powder have uniform and constant density, and are much clearer than conventional positive developing powders. Hereinafter, the present invention will be explained in detail with reference to Examples.
In the examples, parts represent parts by weight. Example 1 Add 100 parts of styrene-n-butyl methacrylate copolymer and 5 parts of carbon black to 5 parts of the dye represented by , mix well, knead while heating and melting, cool, coarsely pulverize with a mixer, and then centrifuge at high speed. The toner was pulverized using a type pulverizer to obtain a fine, positively charged toner. Apply the above toner to a commercially available copying machine using a zinc oxide photoreceptor at a weight ratio of 5:100 and a diameter of 100~
When mixed with 150 μm iron powder, clear images with no fog were obtained. The amount of charge on the toner was measured using the blow-off method, and on average it was
22μc/g, and the charge distribution is 22~23μc/g
It was almost uniform. Examples 2 to 13 According to Example 1, toners containing a metal complex compound were obtained with the compositions shown in the following table. The measurement results of the charging characteristics of these toners are also summarized in the table.

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Claims (1)

[Claims] 1 The following general formula (1) (In the formula, R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and an alkyl group having 2 to 4 carbon atoms.
5 alkoxycarbonyl group, aminosulfonyl group, acylamino group, aminocarbonyl group, alkylaminocarbonyl group having 2 to 5 carbon atoms, alkylsulfonyl group having 1 to 3 carbon atoms, nitro group, cyano group, halogen atom, m is 1, 2, 3 or 4, and when m is 2 or more, R can be different substituents, and Y has 1 carbon number
~4 alkylene group, Z represents a quaternary ammonium group, M represents a chromium atom or a cobalt atom, and X represents an anion. )
An electrophotographic toner comprising a 2:1 type metal complex salt compound represented by the following as a charge control agent and a colorant.