JPH0564341B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a toner used when developing electrostatic latent images such as electrophotography or electrostatic recording. Methods for developing electrostatic latent images using toner include the magnetic brush method, which uses developer powder containing carrier particles, mainly iron powder, and the cascade method, which uses developer powder containing glass particles as carrier particles. It has been known. The developing powders used in these development methods include fine powders in which dyes or pigments are dispersed in thermoplastic resins, and developing powders to which a third substance is added as described in Japanese Patent Publication No. 44-6398, etc. is also known. However, since the above developer powder alone does not have desirable charging properties, dyes or pigments that impart charging properties are added, and currently in practical use, when imparting a negative charge to toner, When a metal-containing dye imparts a positive charge, there is a nigrosine dye. These dyes are charge control agents with excellent properties, but because they are colored substances, they cannot be used in color electrophotography, which has been particularly in demand in recent years. In addition, toners containing nigrosine dyes used in plastic toners exhibit good development characteristics initially, but have the disadvantage of short lifespans. There is a strong demand for colorless or light-colored charge control agents. However, no charge control agent satisfying the above characteristics has yet been found. An object of the present invention is to provide a plastic toner having good development characteristics and a long life. That is, the present invention provides a toner for use in developing an electrostatic image, which has the general formula () [In the formula, R ₁ , R ₂ , R ₃ , R ₄ have 1 to 6 carbon atoms
an alkyl group, R ₅ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ₆ is a hydrogen atom, and an alkyl group having 3 carbon atoms
It represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 3 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms, and n represents an integer of 1 to 4. ^R7 represents an acyl group or an N-substituted carbamoyl group when n=1, a diacyl group, dicarbamoyl group or a carbonyl group when n=2, a triacyl group when n=3, and a tetraacyl group when n=4. ] A toner for developing an electrostatic image is characterized by containing a piperidine compound represented by the following. In the general formula (), R ₁ , R ₂ , R ₃ , and R ₄ are optionally branched alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl, and R ₅ is hydrogen. Atom, methyl group, ethyl group,
An optionally branched alkyl group such as a propyl group, butyl group, or pentyl group; R ₆ is a hydrogen atom; _R7 is an acetyl group, a propionyl group, an acryloyl group, a crotonoyl group, an alkenyl group such as an allyl group, a methallyl group, a butenyl group, an aralkyl group such as a benzyl group, a phenylethyl group, or a phenylpropyl group. Enylacetyl group, benzoyl group, ethoxycarbonyl group, propoxycarbonyl group, dodecyloxycarbonyl group, benzyloxycarbonyl group, phenoxycarbonyl group, methylcarbamoyl group, butylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group, diacyl group The following groups, -COCH ₂ CH ₂ -CO-, -CO(CH ₂ ) ₃ -CO-, -
CO−(CH ₂ ) ₄ −CO−, −CO(CH ₂ ) ₆ −CO−, −CO
(CH ₂ ) ₈ CO−,

【formula】

[Formula] The dicarbamoyl group includes the following groups, -CONH-(CH ₂ ) ₆ -NHCO-, Carbonyl groups and triacyl groups include the following groups,

【formula】

【formula】

[Formula] Tetraacyl groups include the following groups: are listed as typical substituents. The piperidine compound represented by the general formula () is produced by a method similar to that described in JP-A-46-42618. The toner contains a thermoplastic resin and a coloring substance in addition to the charge control agent. Examples of thermoplastic resins include monopolymers or copolymers such as styrene, p-chlorostyrene, and vinyltoluene, styrene-propylene copolymers, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate, ethyl, and butyl acrylate. or octyl copolymer, styrene-methyl methacrylate, ethyl or butyl copolymer, styrene-acrylonitrile copolymer, styrene-isobutylene copolymer, styrene-butadiene copolymer, polyvinyl chloride, polyvinyl acetate, polyethylene , polypropylene, epoxy resin, polyester, etc. are used singly or in combination. Further, as the coloring agent, dyes having no water-soluble groups such as sulfone groups such as azo dyes, anthraquinone dyes, nitro dyes, and quinophthalone dyes, and pigments such as quinacridone and phthalocyanine are used. By mixing the piperidine compound represented by the general formula () of the present invention into a toner, the toner can be positively charged, and a toner with good development characteristics and a long life can be produced. The amount of the charge control agent of the compound of the present invention mixed in the toner is usually 10% by weight or less, preferably 0.5 to 5% by weight. The toner of the present invention is mixed with a carrier to form a developer, and is used after being positively charged. As the carrier, for example, iron powder, glass beads, and those whose surfaces are treated with resin are used. The present invention will be explained in detail below with reference to Examples.
In the text, parts represent parts by weight. Example 1 100 parts of styrene-butyl acrylate copolymer,
3 parts of copper phthalocyanine and 1 part of the piperidine compound represented by the following structural formula (1) were uniformly premixed in a ball mill for 20 hours, then sufficiently kneaded in a heated roll mill, and finely pulverized to 1 to 40 μm to obtain a powder toner. A developer was prepared by mixing 5 parts of the obtained toner and 95 parts of iron powder, and copies were made using a dry electronic copying machine.
Good images were obtained and the lifespan was also good. Example 2 In Example 1, a styrene-butadiene copolymer, an epoxy resin, a polyester resin, a styrene oligomer, or a styrene-octyl acrylate copolymer was used instead of the styrene-butyl acrylate copolymer, and the other examples were as follows. Copying was carried out in the same manner as in Example 1. As a result, good images were obtained in each case. Example 3 Copying was carried out in the same manner as in Example 1, except that the piperidine compound (1) used in Example 1 was replaced with compounds of the following structural formulas (2) to (14). As a result, good images were obtained in each case.

Claims (1)

[Scope of Claims] 1. A toner for developing an electrostatic image, characterized in that the toner used for developing an electrostatic image contains a piperidine compound represented by the general formula (). [In the formula, R ₁ , R ₂ , R ₃ , R ₄ have 1 to 6 carbon atoms
an alkyl group, R ₅ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ₅ is a hydrogen atom, and an alkyl group having 1 to 5 carbon atoms
It represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 3 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms, and n represents an integer of 1 to 4. _R7 is
When n=1, it represents an acyl group or an N-substituted carbamoyl group; when n=2, it represents a diacyl group, dicarbamoyl group or carbonyl group; when n=3, it represents a triacyl group; when n=4, it represents a tetraacyl group. ]