JPH0816808B2 - Toner for electrophotography - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toner which is a developer for electrophotography.

(Prior Art) In electrophotography, an electrostatic latent image is formed on a photoconductor made of a photoconductive substance, developed with a powder developer, visualized, and then fixed with heat or a solvent. The method is common.

As a developer for such electrophotography, a mixture of fine particle powder made of a resin called a toner and a colorant and fine glass beads or iron powder called a carrier is used.

The photoconductor layer can be positively or negatively charged, so that exposure under the original gives a positive or negative electrostatic latent image. Therefore, when the negative electrostatic latent image is developed with the positively charged developing powder, a positive-positive image corresponding to the original is produced. However, when development is performed on the positive electrostatic latent image with negatively charged developing powder, the black and white tones are reversed and the original negative or positive-negative image is obtained.

Generally, the developing powder is a fine particle powder obtained by mixing a coloring agent such as a dye or a pigment with a synthetic resin.

The charging property of the developing powder is governed by the resin as its main component, but normally, the desired triboelectric charging property is obtained by adding a charge control agent.

(Problems to be solved by the invention) As charge control agents, dyes and pigments such as oil black, nigrosine (Japanese Patent Publication No. Sho 48-25669), aniline black, crystal violet, and metal-containing azo dyes have been known. Has been. Known colorless charge control agents include quaternary ammonium salts (JP-A-57-119364), metal soaps, and the like. However, these control agents are apt to decompose or deteriorate due to humidity, temperature, light, or mechanical impact, and when used in a toner, the charging characteristics of the control agent may change due to environmental changes or long-term use. Has a drawback that the developed image is adversely affected.

(Means for Solving Problems) The present invention solves the drawbacks described above. Special
Has higher thermal stability than conventional quaternary ammonium salts
By discovering a new compound,
Providing extremely stable toner in the heating process such as heat fixing
be able to. That is, the electrophotographic toner of the present invention
Is the following general formula as a charge control agent in the binder resin.
(1)(Where R₁, R₂Are each independently an alky having 1 to 20 carbon atoms.
Represents the radical R and also R₁And R₂May form a ring. R₃branch
Represents an alkyl group having 1 to 20 carbon atoms which may be separated,
X Represents an anion. ) Contains a compound
It is characterized by doing.

 Examples of specific compounds used in the present invention will be given. General formula
In (1), as an onium part, And so on. Anion X as,
F , Cl , Br , I , 1 / 2CO₃ ² , CN , NO₃ , 1 /
2SO_Four ² , CH₃SO_Four ,PF₆ , BF_Four , ClO₃ , ClO_Four , R_Five−COO (R_FiveIs C₁~ C₁₈Of saturated and unsaturated alkyl groups of
I forgot. ) Or phosphomolybdic acid, silico molybdenum
Acid, phosphotungstic acid, silicotungstic acid, etc.
Lopoly acid, molybdic acid, paratungsten
Examples thereof include acids and metatungstic acid.

Examples of the binder resin include polystyrene, styrene monomers such as polyvinyltoluene and its substituted monomers, styrene-substituted styrene copolymers, styrene-acrylic acid ester-based copolymers, and styrene-methacrylic acid ester-based copolymers. Examples thereof include polymers, styrene-acrylonitrile copolymers, polyvinyl chlorides, polyethylenes, silicone resins, polyesters, polyurethanes and polyamides.

The developing powder of the present invention is prepared by melt-blending the compound of formula (1) with respect to the synthetic resin in a polymerization ratio of 1 to 50%, solidifying the mixture, and then pulverizing it with a ball mill or other pulverizer, or polymerizing the synthetic resin monomer. It can be produced by adding an initiator, adding the compound of the formula (1) in the range of 1 to 50% by weight relative to the monomer, and polymerizing the mixture while suspending it in water. At this time, other coloring agents or carbon black may be added as a dye. The developer powder thus produced gives a charge amount suitable for developing an electrostatic image due to friction with the carrier, and the charge amount is kept constant even after repeated development, and the charge distribution is uniform. Holds constant. In addition, the charge control agent of the present invention,
The so-called one-component toner containing magnetic iron powder also provides excellent charging characteristics.

(Example) Hereinafter, the present invention will be illustrated by examples. Parts means parts by weight.

Example 1 1 part of the compound represented by and 5 parts of carbon black are kneaded with 100 parts of a styrene-n-butyl methacrylate copolymer by heating. After cooling, the mixture was roughly pulverized with a mixer, then pulverized with a jet powder pulverization and classified to obtain a powder having a particle size of 10 to 20 μm.
When this black powder was mixed with an iron powder carrier at a weight ratio of 5 to 100, the positively charged amount of the charge was 20 μC / g. When an image was produced with a commercially available copying machine, a clear image was obtained at the initial stage and after 10,000 copies.

Example 2 Instead of the compound shown in Example 1 Using the same procedure as in Example 1, a toner was obtained. The charge amount was 13 μC / g.

 Example 3 The following are summarized in Table 1.

The toner preparation method is the same except that only the charge control agent is changed.
According to Example 1.

Example 17 1 part of the compound represented by the formula (1) and 2 parts of copper phthalocyanine were kneaded with 120 parts of a styrene-ethylhexyl methacrylate copolymer by heating and finely ground to 10 to 20 μm to obtain a toner. 5 parts of this toner and 100 parts of iron powder carrier were mixed to prepare a developer. I made a copy with a commercially available copy machine. as a result,
A clear image was obtained and the life was good.

Claims (4)

[Claims] 1. The following general formula (1)(Where R₁, R₂Are each independently an alky having 1 to 20 carbon atoms.
Represents the radical R and also R₁And R₂May form a ring. R₃Is
Represents an alkyl group having 1 to 20 carbon atoms which may be branched.
Then X Represents an anion. )
An electrophotographic toner containing the toner. 2. A compound represented by the general formula (1), wherein R ₁ ,
Both R ₂ are -n-C ₄ H ₉ , and R ₃ is The electrophotographic toner according to claim 1. 3. A compound represented by the general formula (1), wherein R ₁ and R _{2 are}
Is but both _{-n-C 6 H 13, R} 3 The electrophotographic toner according to claim 1. 4. A compound represented by the general formula (1), wherein R ₁ and R _{2 are}
so And R ₃ The electrophotographic toner according to claim 1.