JPH0363664A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To form sharp images and to allow the continuous use of the toner by incorporating a specific charge control agent into the toner. CONSTITUTION:The compd. expressed by formula I is incorporated as the charge control agent into this toner. In the formula, R denotes H, alkyl, halogen, etc.; m, n denote 1 to 4; X denotes Mg, Ca, Zn, etc. The more specific example of the charge control agent expressed by the formula includes the compd. expressed by formula II, etc. This charge control agent has the good dispersibility with resin components, is stable and colorless up to the temp. at the time of melt kneading and imparts a negative charge to the toner and, therefore, the toner which forms the sharp images and is continuously usable is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toner for developing electrostatic latent images in electrophotography.

(Prior art) In electrophotography, a latent image is formed on a photoconductor made of a photoconductive substance, and this is developed with a powder developer to make it visible. The common method is to fix it on paper using pressure. Developers for such electrophotography include natural resins or synthetic resins, colorants,
A 2R/separate developer consisting of a mixture of a toner with a charge control agent, a fluidizing agent, etc. dispersed therein and a carrier of iron powder or ferrite powder, and a natural resin or synthetic resin with a coloring agent, a charge controlling agent, a fluidizing agent, etc. Developers can be roughly divided into two types: one-power type developers, which are more powerful than magnetic materials.

2r! A split-thread developer achieves development by adhering charged toner to an electrostatic latent image through friction with a carrier, and as a 1r & split-thread developer, conventionally this is used instead of a carrier. Toner that is charged by friction with a brush-like or plate-like friction member that has a similar function is known, and recently, toner that is charged by friction with a brush-like or plate-like friction member has been developed. Toners that are loaded by mutual friction have become known. The photoconductor layer can be positively or negatively charged so that exposure under the original produces a positive or negative electrostatic latent image.

Depending on the polarity of this electrostatic latent image, the developing toner remains positive or negative.

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 large solid surface resistance value, so The resulting image is prone to fogging and becomes unclear. Therefore, in order to impart the desired triboelectric charging properties to the toner, dyes, pigments, and even electric charges that impart an electric charge are used.
The addition of a conditioner has been practiced and is now in practical use in the technical field.

(Problems to be Solved by the Invention) However, these dyes and pigments used as charge control agents have complex structures and lack stability, such as mechanical friction and impact, changes in temperature and humidity conditions, and electrical resistance. It easily decomposes or changes in quality due to impact or light irradiation, resulting in a loss of charge adjustment ability.One essential defect is that it is a colored substance, so for toners with a specific hue, colorless or substantially This is in violation of the requirement that a charge control agent that can be considered colorless be used.

(Means for Solving the Problems) The present inventors have developed a toner material that has good dispersibility with the resin component, is thermally stable up to a temperature that allows sufficient melting and mixing, and is colorless. They discovered a compound that can impart a negative charge to the toner and invented an excellent toner.

That is, the present invention relates to the general formula (I) (I) (wherein R represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, and m and n are 1.2.3 or 4.
The electrophotographic toner is characterized in that it contains, as a charge control agent, a compound represented by 1, where X2Φ represents a divalent metal ion.

The compound represented by general formula (I) will be explained in detail. Examples of the alkyl group of the anion R include methyl group, ethyl group, ■-butyl group, tert-butyl group, 1so-7mil group, 1so-octyl group, n-dodecyl group, nniophtadecyl group, etc. The groups include methoxy group, 1so-propoxy group, n-butyloxy group, n-
Examples include octyloxy groups, and halogen atoms include
Examples include F%CI, Br, I, etc. In addition, divalent metal ions include M g 2 @, Cs2Φ, Zn2
Examples include Φ.

Specific examples of the compound represented by general formula (I) are shown below.
Note that compound No. is also commonly used in the following examples.

Compound no.

Structure Construction formula Compound no.

Structural Formula A method for producing compound (I) used as a charge control agent in the present invention is described in US Pat. No. 3,539,614 and the like. For example, magnesium borodisalicylate can be obtained by adding salicylic acid to an aqueous solution of boric acid and magnesium hydroxide and causing a reaction. Incidentally, the amount of the compound represented by general formula (I) added to the toner component is generally 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the resin. Make it contain.

In addition to the compound of the above general formula (I), the toner of the present invention includes:
One or more of known toner resins such as styrene resin, styrene-acrylic resin, styrene-butadiene resin, epoxy resin, polyester ml paraffin wax, etc. in consideration of adhesiveness, storage stability, fluidity, pulverizability, etc. A mixture of seeds is used. As the coloring agent, many known dyes and pigments can be used, but those that are particularly excellent as toners for color copying include benzodine yellow, quinacridine, copper 7 talocyanine blue, copper 7 thalocyanine green, etc. can be mentioned.

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

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

Note that parts in the examples represent parts by weight.

Oimine Salmon L 100 parts of styrene resin, 6 parts of carbon black, No.
A mixture of 2 parts of compound 1 is uniformly premixed using a ball mill to prepare a premix. Next, heat melt kneading,
After cooling, it was coarsely ground using a vibration mill and further finely ground using a jet mill to obtain black horse chestnut. The particle size of this black toner was 8 to 15 μm. A developer was prepared by mixing 95 parts of iron carrier with 5 parts of the resulting toner. The initial blow-off charge amount of this developer is -20.5μC/g
Met.

When a toner image was formed using this developer on a commercially available selenium drum using a magnetic brush development method, a clear image without fogging was obtained. No deterioration in copy quality was observed even after continuous copying of 100 copies using this toner 1±.

100 parts of styrene-acrylic copolymer resin, yellow dye (c
, r, Disbirds Yellow 33) (6 parts) and 2 parts of compound No. 3 were treated in the same manner as in Example 1 to obtain a yellow toner. The initial blow-off charge amount of the developer prepared from the obtained yellow toner in the same manner as in Example 1 was -25.7.
It was μC/g.

When copies were made using this developer in the same manner as in Example 1, clear yellow images without fog were obtained. With this toner, no deterioration in copy quality was observed even after 10,000 continuous copies were made.

Styrene-〇-butyl methacrylate copolymer resin 10
0 parts, red dye (C, I, Pigment Red 12) 8
A blend of 2 parts of compound No. 4 was treated in the same manner as in Example 1 to obtain a red toner. The developer prepared from the obtained red toner in the same manner as in Example 1 had an initial blow-off charge amount of -22.4 μC/g.

When copies were made using this developer in the same manner as in Example 1, clear red images without fog were obtained. With this toner, no deterioration in copy quality was observed even after continuous copying of 100 sheets.

Tomokame Salmon E 100 parts of polyester resin, blue dye (c, r.

A blend of 6 parts of Pigment Blue 15) and 2 parts of compound No. 5 was treated in the same manner as in Example 1 to obtain a blue toner.

The initial blow-off charge amount of the developer prepared from the obtained blue toner in the same manner as in Example 1 was -27.3 μC/g.
Met.

When this developer was used for copying in the same manner as in Example 1, no deterioration in copy quality was observed even after 100 copies of continuous copying were made using the 0 toner, which produced clear blue images without fog.

(Effects of the Invention) The charge control agent used in the present invention has excellent mechanical friction and impact stability, temperature and humidity stability, etc., and is colorless, so it can be used in electrophotography with clear images and continuous use. A toner for use was obtained.

Claims (1)

[Claims] The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (I) (In the formula, R represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, and m and n is 1, 2, 3 or 4, and X^2^■ represents a divalent metal ion.