JPH01306861A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain a colorless electrophotographic toner having high heat stability and being chargeable negatively as well as having superior dispersibility into a resin component by incorporating a specified compd. as charge controller. CONSTITUTION:A compd. expressed by the formula I is incorported as charge controller. In hte formula I, R is an H atom, alkyl group, etc.; each m and n is 1-4; X' is an H ion, alkali metal ion, aliphatic ammonium ion, etc. The compd. expressed by the formula I is incorporated into a toner component in a proportion of generally 0.1-10, more pref. 0.5-5 pts.wt. per 100 pts.wt. of a resin. Thus, a colorless elecetrophotographic toner capable of providing distinct picture images and durable against continuous use is obtd. because a colorless charge controller having high stability against mechanical friction, mechanical shock, temp., and moisture is used therein.

Description

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

(Conventional technology) Electrophotography consists of photoconductive materials, etc.
'The general method is to form a latent image on a photoconductor, develop it with a powder developer to make it visible, and then fix it on paper using heat, a solvent, or in some cases pressure. In this type of electrophotography, the agent is a two-component system consisting of a mixture of a toner in which a coloring agent, a charge control agent, a fluidizing agent, etc. are dispersed in a natural or synthetic resin, and a carrier of iron powder or ferrite powder. Developers can be broadly classified into one-component developers, which are composed of natural υl fats or synthetic resins, colorants, charge control agents, fluidizing agents, and magnetic materials.

A two-component developer achieves development by causing charged toner to adhere to an electrostatic latent image through friction with a carrier. Toners that are charged by friction with brush-like or plate-like friction members that have the same function as carriers (1) are known as substitutes for carriers. A toner that is charged by mutual friction with the fine magnetic powder has 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, the main component of the toner (
(It has also been proposed to utilize the triboelectricity of fat, but in this method, the toner has a small charge and a high 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, it has been attempted to add charge-imparting dyes, pigments, and even charge control agents, and this technique is currently being put into practical use in this 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. Decomposes or changes in quality due to impact or light irradiation, resulting in a charge of 8! L adjustment is likely to be lost. One essential flaw is that since it is a colored material, it violates the requirement that toners with a specific hue require a charge control agent that can be considered colorless or substantially colorless. At the point.

(Means for Solving the Problems) The present inventors have developed a toner material that has good dispersibility with the resin component, has thermal stability up to a temperature that allows sufficient melt-kneading, and is colorless. By giving a negative charge to g
They discovered a compound that could achieve this and invented an excellent toner.

That is, the present invention is based on the general formula (1) (wherein R represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, n and n are 1, Φ 2.3 or 4, and x is a hydrogen ion, Containing a compound represented by an alkali metal ion, an aliphatic ammonium ion (including substituted aliphatic ammonium ions), an alicyclic ammonium ion, or a heterocyclic ammonium ion as a charge control agent is considered to be a vf characteristic. This is a toner for electrophotography.

Specific examples of the anion of the compound represented by general formula (1) are shown below.

Anion No., Structural formula anion No.,
In addition, the alkali metal ion as a cation of the compound represented by the structural formula ([) is L
+, Na, K, etc. Examples of aliphatic and alicyclic ammonium ions include ammonium ions represented by formula (n), and specific examples of R1, R2, R1 and R are shown in Table 1.

R2-N-R, (H) Specific examples of heterocyclic ammonium ions are shown below.

Ammonium ion No. Structural formula % Formula % The method for producing the compound (1) used as the charge control agent of the present invention is described in US Pat. No. 3,539,614 and the like. For example, ammonium borodisalicylate can be obtained by adding salicylic acid to an aqueous solution of boric acid and an amine and allowing the reaction to occur.

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.

The toner of the present invention includes a pond of the compound of the above-mentioned removal allowance (1),
Considering adhesiveness, storage stability, fluidity, crushability, etc., styrene (5 (fat), styrene-acrylic resin, styrene-butadiene resin, epoxy resin, polyester + 111R
, paraffin wax, and other known resins for toners, or a mixture of several types thereof may be used. In addition, as a coloring agent,
Although many known dyes and pigments can be used, some that are particularly excellent as toners for color copying include benzidine yellow, quinacridine, copper phthalocyanine blue, and copper 7 thalocyanine green.

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

(Example 1) A mixture of 100 parts of styrene resin, 6 parts of carbon black, and 2 parts of dimethylammonium boron salicylate is uniformly premixed in a ball mill to prepare a premix. Next, the mixture was heated and melted and kneaded, and after cooling, it was coarsely pulverized using a vibrating mill, and further finely pulverized using a shedding mill to obtain a black toner. The particle size of this black toner was 8 to 15 μIff.

A developer was prepared by mixing 95 parts of iron powder carrier with 5 parts of the obtained toner. The initial blow-off charge amount of this developer was -25.9 μC/g.

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. With this toner, no deterioration in copy quality was observed even after continuous copying of 100 sheets.

(Example 2) 100 parts of styrene-acrylic copolymer resin, yellow dye (C
, 1, Disbirds Yellow 33) 6 copies, bottle
'Robimata (3,5-not-tert-butylsalicylic acid)
A formulation of 2 parts dimethylammonium was processed as in Example 1 to obtain a yellow toner. The obtained yellow toner 1)
The initial blow-off charge amount of the developer prepared in the same manner as in Example 1 was -23.6 μC/8.

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.

(Example 3) Styrene-n-butyl methacrylate copolymer resin 10
A mixture of 0 parts of red dye (C, I, pigment red), 8 parts of red dye (C, I, pigment red), and 2 parts of tri-butyl)ammonium borodisalicylate was processed in the same manner as in Example 1 to obtain a red toner. The initial blow-off charge amount of the developer prepared from the obtained red toner in the same manner as in Example 1 was -23.7 μC/g.
Met.

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 10,000 continuous copies were made.

(Example 4) Polyester resin 1. O0 parts, blue dye (C, I.

Pigment Blue 15) 616 and 2 parts of diethylammonium borodisalicylate were treated in the same manner as in Example 1 to obtain a blue toner. The developer prepared from the obtained blue toner in the same manner as in Example 1 had an initial blow-off charge amount of -29.1 μC/g.

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

(Effects of the Invention) The charge control agent used in the present invention has excellent mechanical friction and impact stability, temperature and humidity stability, and is colorless, so it is an electrophotographic toner that provides clear images and can be used continuously. was gotten.

Patent applicant Nippon Carlit Co., Ltd.

Claims (1)

[Claims] The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, 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
and represents a hydrogen ion, an alkali metal ion, an aliphatic ammonium ion (including substituted aliphatic ammonium ions), an alicyclic ammonium ion, or a heterocyclic ammonium ion. ) A toner for electrophotography, characterized in that it contains a compound represented by the following formula as a charge control agent.