JPH08272145A - Electrostatic charge controlling agent - Google Patents

Abstract

PURPOSE: To provide an electrostatic charge controlling agent for preparing a toner having good dispersiveness in a binder resin and also having an excellent gradation property. CONSTITUTION: An electrostatic charge controlling agent is composed of a compound given in the formula and a metal soap. In the formula X is either of Cl, Br, SO2 NH2 , SO2 CH3 , and SO2 C2 H5 while [A]<+> is hydrogen ion, ammonium ion, or alkyl ammonium in straight chain or branching having the number of carbons between 8-28 which may be intercepted by the oxygen atom.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a charge control agent.

[0002]

2. Description of the Related Art Image forming processes such as electrostatic recording and electrostatic photography using static electricity are performed on a photoreceptor obtained by applying selenium, cadmium sulfide, amorphous silicon, etc. onto a substrate such as Al. The process of forming an electrostatic latent image by an optical signal and the colored fine particles of 10 to 50 μm, which is called toner, are contact-charged by a carrier (iron powder, ferrite powder, etc.) and acted on the electrostatic latent image. It consists of the process of imaging.

Colored fine particles generally called a toner are mainly composed of a binder resin and are composed of a charge control agent, a colorant, and the like. Among them, the charge retention by triboelectric charging with a carrier and the charge characteristic of the toner are controlled. The charge control agent having a function is a particularly important component in the toner components.

The toner is required to have excellent chargeability, fluidity, fixability, etc. as the quality characteristics required, but these characteristics are greatly influenced by the charge control agent used in the toner. Is.

As the charge control agent used in the conventional toner, (1) as a negative charge control agent, a 2: 1 type metal-containing complex salt dye (Japanese Patent Publication Nos. 45-26478, 59-7385 and 41-20153). , Phthalocyanine pigments (JP-A-52-45931), (2) as positive charge control agents, nigrosine dyes and various quaternary ammonium salts (Journal of Electrostatic Society, Vol. 4, No. 3, p-144, 1980) are known. However, toners using these as charge control agents are
It does not sufficiently satisfy the quality characteristics required for the toner such as chargeability and stability over time. For example, those using a 2: 1 type metal-containing complex salt dye known as a negative charge control agent have a tentative level of charging property, but have poor dispersibility in a binder resin. Due to the drawback that it was not uniformly distributed in the binder resin, the distribution of charge amount of the toner obtained was also extremely lacking in sharpness. As a result, the image obtained using such toner is inferior to the image formation with low gradation.

[0006]

It is desired to develop a toner having a good dispersibility of a charge control agent in a binder resin and an excellent gradation.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made diligent efforts to improve the above-mentioned problems, and as a result, the compound of formula (1)

[0008]

Embedded image

(In the formula (1), X is Cl, Br, SO ₂ N
The _{H 2, SO 2 CH 3,} SO 2 C 2 H 5, A + is hydrogen ion, ammonium ion, and a straight-chain or branched in one carbon atoms which may be interrupted by oxygen atoms from 8 to 28 Represents a good alkylammonium. ) And a metallic soap in the toner, especially in the toner particles, the dispersibility of the compound of formula (1) in the binder resin is improved, the charge amount distribution of the toner becomes sharp, and the charging characteristics are improved. The present invention has been completed by discovering that the above is significantly improved.

Specific examples of the compound of the formula (1) used in the present invention include the compounds shown in Table 1. In Table 1, X and A represent X and A of the compound of formula (1).

[0011]

[Table 1] Table 1

Specific examples of the metallic soap are as follows: lithium stearate, magnesium stearate, aluminum stearate, calcium stearate, calcium laurate, zinc stearate, barium stearate, barium laurate, Examples include zinc laurate.

The compound of formula (1) is a 4-chloro-aminophenol, 4-sulfoamido-2-aminophenol, 4-bromo-2-aminophenol, 4-sulfomethyl-2-aminophenol, or 4-sulfoethyl-.
Diazotization of amines such as 2-aminophenol by a known method, and complexing of a monoazo compound obtained by coupling to β-naphthol with a chromium complex by a known method, an alkali metal salt of the obtained chromium complex salt is converted into hydrochloric acid, sulfuric acid, When treated with a proton donating agent such as acetic acid, A ⁺ in Formula (1) is hydrogen ion. When this is further treated with aqueous ammonia, A ⁺ becomes ammonium ion in the formula (1), and the change of aqueous ammonia is octylamine, decylamine, laurylamine, cyristylamine, palmitylamine, cetylamine, 2-ethylhexyloxypropylamine, Treatment with lauroxypropylamine, caproxypropylamine and stearylamine gives the formula (1) in which A ⁺ is alkylammonium.

The method of incorporating the charge control agent of the present invention comprising the compound of the formula (1) and metallic soap into the toner for electrophotography, in particular, the particles of the toner, may be prepared in advance by using the compound of the formula (1) and metallic soap. Is mixed to obtain a charge control agent of the present invention, which is attached to a binder resin. A more preferable method is to obtain a mixed pulverized product of the compound of the formula (1) and metallic soap, which is used in the present invention. It is a method of adding it as a charge control agent to the binder resin. As a method of obtaining a mixed pulverized product, for example, a method of mixing the compound of the formula (1) and metallic soap and further pulverizing with a yarn pulverizer can be mentioned. Ratio of compound of formula (1) and metallic soap (weight ratio)
Is a metal soap 0.1-1 ..
It is more preferably 5 to 0.2.

In producing an electrophotographic toner using the charge control agent of the present invention comprising a compound of the formula (1) and a metal soap or a compound of the formula (1) and a metal soap, a colorant and a binder resin It is said that and are kneaded under the melting of the binder resin by a device capable of heating and mixing treatment such as a heating kneader and two rolls, and cooled and solidified, and are pulverized by a pulverizer such as a jet mill and a pole mill to a particle size of 1 to 50 μm. Is the most convenient method. In the above, as the binder resin, acrylic resin, polystyrene resin, styrene-methacrylate copolymer, epoxy resin, polyester resin and the like, and as the colorant, carbon black, pigments and the like, but are not limited to these is not. The amount of the charge control agent of the present invention used is such that the compound of formula (1) is 0.5 to 30 parts, preferably 0.5 to 10 parts, relative to 100 parts by weight of the binder. If necessary, a flow agent such as silicon oxide and an antifoggant such as mineral oil may be added to the electrophotographic toner using the charge control agent of the present invention.

The electrophotographic toner using the charge control agent of the present invention is mixed with a carrier prepared from iron powder or the like in a conventional manner in a ratio of 3:97 to 50:50 (toner: carrier weight ratio) to obtain an electrophotographic toner. Used as a developer. This electrophotographic toner has a characteristic that it has a sharp charge amount distribution as compared with a toner using a conventional charge control agent, and as a result, an image with extremely high gradation is obtained and the image forming ability is extremely high. It is characterized by being good.

[0017]

The present invention will be described in more detail with reference to the following examples. In the examples, “parts” means parts by weight unless otherwise specified.

Example 1. By treating 60 parts of the compound of formula (2) and 40 parts of zinc stearate with a compounding machine for 30 minutes and then pulverizing with a yarn mill, the compound of formula (2)
A mixture of the above compound and zinc stearate (mixing ratio 60: 4
A charge control agent of the present invention consisting of 0) was obtained.

[0019]

Embedded image

Styrene methacrylate copolymer 10
0 part, carbon black 4 parts, 6.7 parts of the charge control agent of the present invention (a mixture of the compound of formula (2) and zinc stearate) obtained above was styrene-methacrylate copolymer (in a heating kneader ( (Binder resin) is melted and the whole is mixed, then cooled, coarsely crushed with a hammer mill,
Then, it was finely pulverized with a jet mill. The obtained fine powder was classified by an airflow type precision classifier to obtain an electrophotographic toner containing 10 to 12 μ of the charge control agent of the present invention in the particles. The obtained toner was mixed with an iron powder carrier of about 200 mesh in a weight ratio of 4:96 (toner: iron powder carrier),
A developer was obtained, and the initial specific charge of this developer was measured by a blow-off device. As a result, it was −26 μc / g.
Further, when copying was performed with a copying machine using the above-mentioned developer, a clear image having excellent gradation was obtained.

Example 2 In the same manner as in Example 1, a charge control agent of the present invention comprising a mixture of the compound of formula (3) and Mg stearate (mixing ratio 80:20) was obtained.

[0022]

[Chemical 4]

100 parts of styrene oligomer resin, 4 parts of carbon black, the charge control agent of the present invention obtained above (mixture of compound of formula (3) and Mg stearate)
3.75 parts were mixed with a two-roll with the styrene oligomer resin being melted, and after cooling, coarsely crushed with a hammer mill,
Then, it was finely pulverized with a jet mill. The obtained powder was classified by an airflow type precision classifier to obtain an electrophotographic toner containing 10 to 15 μ of the charge control agent of the present invention in the particles. With respect to the obtained toner, a developer was prepared in the same manner as in Example 1 and the initial specific charge was measured to be −25.6 μc / g.
Met. Further, when copying was performed in the same manner as in Example 1, a clear image with high gradation was obtained.

Example 3 In the same manner as in Example 1, a charge control agent of the present invention comprising a mixture of the compound of the formula (4) and Ca stearate (mixing ratio 70:30) was obtained.

[0025]

Embedded image

Polyester resin 100 parts, carbon black 5 parts, charge control agent of the present invention obtained above (mixture of compound of formula (4) and Ca stearate) 7.2
Parts were mixed in a heating kneader while the polyester resin was melted, cooled, coarsely pulverized with a hammer mill, and then finely pulverized with a ball mill. The obtained powder was classified by an airflow type precision classifier to obtain an electrophotographic toner containing 10 to 15 μ of the charge control agent of the present invention in the particles. A developer was prepared for the obtained toner in the same manner as in Example 1 and the initial specific charge was measured and found to be −23.8 μc / g. Further, when copying was performed with a copying machine as in Example 1, a clear image with high gradation was obtained.

Examples 4 to 10 In the same manner as in Example 1, a charge control agent of the present invention comprising a mixture of the compound of formula (1) as shown in Table 2 and metallic soap was prepared and used for electrophotography. A toner is prepared (however, the composition ratio of the charge control agent in Table 2 is the composition ratio with respect to 100 parts of the binder resin used in Example 1), and a developer is prepared in the same manner as in Example 1, and the specific charge amount is changed. The measurement was performed, and the results are also shown in Table 2. Developers prepared from toners obtained with any of the charge control agents of the present invention gave copies with sharp images with high gradation.

COMPARATIVE EXAMPLE 1 Instead of the mixture of the compound of formula (2) and zinc stearate in Example 1, only the compound of formula (2) was used (however, the amount used was 4.02 parts). A developer was prepared in the same manner as in (1). When the specific charge amount of this product was measured, it was at a low level as shown in Table 2. When a copy was made in the same manner as in Example 1 using this developer,
Only an unclear image was obtained.

Comparative Example 2 The same as Example 2 except that only the compound of formula (3) was used in place of the mixture of the compound of formula (3) and Mg stearate used in Example 2 (however, the amount used was 3 parts). And the developer was prepared. When the specific charge amount of this product was measured, it was as shown in Table 2. Further, using this developer, Example 1
When copied in the same manner as described above, only an image having significantly poorer gradation than the image obtained in Example 2 was obtained.

[0030]

[Table 2] Table 2

[0031]

The toner for electrophotography using the charge control agent of the present invention is excellent in specificity of charge, and therefore provides a copy having an image with excellent gradation and high gradation in electrophotographic copying.

Claims (1)

[Claims] 1. A charge control agent comprising a compound of formula (1) and metallic soap. Embedded image (In the formula (1), X is Cl, Br, SO ₂ NH ₂ , SO ₂
CH ₃ or SO ₂ C ₂ H ₅ [A] ⁺ is a hydrogen ion, an ammonium ion, a linear or branched alkylammonium having 8 to 28 carbon atoms which may be interrupted by one oxygen atom. Represents )