JPH02120865A - Color toner particles - Google Patents

Abstract

PURPOSE:To obtain color toner particles high in stability even against changes of environment by incorporating fine conductive particles made of polyaniline. CONSTITUTION:The color toner particles are made substantially of a white, gray, or transparent resin containing a chromatic colorant in the insides or on the surfaces and further, the fine conductive particles made of the polyaniline, and this is a p-type organic semiconductor and its conductivity almost does not change even when it is left in the air for a long period of time, and when it is added to the toner, stable electric characteristics can be obtained and it is substantially colorless and transparent, and when it is used together with a desired colorant, it does not hinder the coloring action of the colorant, thus permitting the obtained toner to maintain a good color tone even if the environment changes, and to form a sharp color image high in stability.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to color toner particles for developing electrostatic images formed in electrophotography, electrostatic printing, electrostatic recording, etc. In particular, it relates to color toner particles having electrical conductivity.

[Conventional technology]

Conventionally, in electrophotography, the surface of a photoreceptor is uniformly charged using, for example, a photoconductive substance.

An electrostatic charge image is selectively formed on the surface of the photoconductor by exposure corresponding to the image information, and a developer to which a predetermined electrostatic charge has been applied via a separate triboelectric charging means is brought into contact with the electrostatic charge image, and the electrostatic charge image in the developer is brought into contact with the electrostatic charge image. toner is deposited on the electrostatic charge image to form a visualized toner image. Next, this toner image is transferred onto recording paper and then fixed using heat or pressure means to obtain a visible image. In this case, the toner particles contain 1
By containing ~10% by weight of a chromatic colorant,
Colors are added to visible images (for example,
No. 6017, JP-A-60-173553, JP-A No. 61-1
No. 24953, Publication No. 61-213859, etc.).

The above toners are broadly classified into insulating toners and conductive toners. First, in the case of development using the former insulating toner, since this insulating toner has a true charge of opposite polarity to that of the electrostatic charge image, development proceeds due to electrical attraction between the two. However, since the true charge of the insulating toner constantly changes depending on the humidity, there is a drawback that the developability changes in accordance with changes in the environment. On the other hand, in the latter case of development using conductive toner, development proceeds based on electrostatic induction of an electrostatic charge image.

There is no need to impart a true charge to the toner, and since the induced charge does not fluctuate due to humidity, there is an advantage that the developability is relatively stable.

[Problem to be solved by the invention]

In order to impart electrical conductivity to the toner and adjust electrical properties such as charging properties, conductive fine particles are contained in the toner (two-component toner).

The most common method is to adhere to the surface of toner particles (-component toner), and carbon blanks are commonly used as the conductive fine particles. This carbon black also has a coloring function in regular toner,
It is added or contained in order to obtain a black visible image as a toner image. For this reason, when used as an electrical property adjusting agent in color toner particles, there is a problem that the color tone of the color toner is significantly inhibited since it originally has a black coloring function. Furthermore, since carbon black is highly hygroscopic, there is also the problem that the electrical resistance of the color toner changes due to changes in the environment, which impairs developability.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems existing in the above-mentioned prior art and to provide color toner particles that have a good color tone and are highly stable against environmental changes.

(Means for Solving the Problems) In order to achieve the above object, in the first invention of the present application, a chromatic colorant is applied inside or on the surface of toner particles made of substantially white, gray or transparent resin. In the color toner particles contained.

Contains conductive fine particles made of polyaniline.

A technical method was adopted.

The polyaniline used in the present invention is 10-' to 10'
It is a P-type organic semiconductor with a conductivity of S/cm, and its conductivity hardly changes even if it is left in the atmosphere for a long period of time. Therefore, when polyaniline is added to a toner, it performs the same function as carbon black, and moreover, provides more stable electrical characteristics than a carbon blank. Furthermore, since polyaniline is substantially colorless and transparent, when used in combination with a desired coloring agent, its coloring action is not hindered. Furthermore, polyaniline can be easily obtained in the form of a fine powder.

0.01-1.0p for uniform dispersion in toner
Those having a particle size of m are preferred.

Note that polyacetylene, for example, is known as a conductive polymer material other than polyaniline, but this polyacetylene has a large change in conductivity in the atmosphere, so it is not suitable for the purpose of the present invention.

In the present invention, the content of conductive fine particles is preferably 5 to 20% by weight.

Further, in the second invention, color toner particles containing magnetic particles or attached to the surface and containing a chromatic colorant inside or on the surface of the toner particles made of substantially white, gray or transparent resin, Conductive fine particles made of polyaniline are attached to the surface. A technical method was adopted.

In the above invention, the adhesion amount of conductive fine particles is 0.1 to 4.
It is preferable to set it as Juyo %.

In the invention of the present application, examples of the resin used as the binder include acrylic resin. Acrylic resins are obtained by polymerizing acrylic acid, methacrylic acid, and their esters. Typical acrylic esters include methyl acrylate, ethyl acrylate, tert-butyl acrylate, neopentyl acrylate, and acrylic esters. Isobonyl acrylate, cyclohexyl acrylate, dodecyl acrylate, hexyldecyl acrylate.

Examples include isopropyl acrylate, tetradecyl acrylate, and unyl acrylate. Typical methacrylate esters include methyl methacrylate, ethyl methacrylate, 2-butyl methacrylate, glycidyl meccrylate, 2-chloroethyl methacrylate, 2-ethylhexyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and methacrylic acid. Examples include isopropyl.

Further, the chromatic colorant may be contained inside the toner particles or may be attached to the surface of the toner particles to form a coating layer, but the amount of the chromatic colorant is 1 weight of the toner particles. If it is less than 10% by weight, the color tone will be insufficient, and if it exceeds 10% by weight, the chromatic colorant released from the surface of the toner particles will appear, causing background fog, which is disadvantageous.

Moreover, the above-mentioned chromatic coloring agent may be of a single color, or may be a mixture or mixture of a plurality of colors. It goes without saying that there is no problem even if the above-mentioned chromatic coloring agent has other functions, such as an electric resistance adjustment function and a charge control function, in addition to the original chromatic coloring agent.

The above coloring agents include rose red iron, cadmium rend, resol and ndrodamine lake Y (red pigments), cobalt blue, alkali blue lake, phthalocyanine blue (blue pigments), chrome green, phthalocyanine green, and malachite green lake. , (the above-mentioned green pigments) and other known pigments, and known dyes such as monoazo dyes and anthraquinone dyes can be used.

The toner of the present invention can also be obtained by, for example, dry heating mixing the resin particles of a predetermined particle size and a colorant, and then coating the surface of the resin particles with the colorant.

Further, as the magnetic particles in the second invention, alloys or compounds containing ferromagnetic elements such as iron, cobalt, nickel, etc. including ferrite and magnetite can be used. It is desirable that the average particle size is 0.1 to 3 μm.

Next, in addition to the above-mentioned resins, examples of resins used as a binder in the second invention include styrene resins, acrylic ester resins, methacrylic ester resins, polyester resins, petroleum resins, nitrocellulose, polyvinyl alcohol, rosin, etc. alone or singly. There are mixtures of these.

In order to create toner particles formed by mixing the above-mentioned magnetic particles and resin, physical methods such as transfer granulation method, melt granulation method, spray drying method, fluid coating method, Pii
Stirring granulation method etc. can be used. Chemical methods include suspension polymerization and interfacial polymerization.

An in-liquid curing coating method, a phase separation method from an aqueous solution system, a phase separation method from an organic solution system, an in-liquid drying method, a melt dispersion cooling method, a capsule inclusion exchange method, a powder bed method, etc. can be used.

Furthermore, various additives can be added to the color toner particles of the present invention, if necessary. Examples of additives include a charge control agent, a mold release agent, a fluidity improver, and a cleaning agent.

〔Example〕

Example 1 Styrene acrylic copolymer 32 parts by weight (SBM-600 manufactured by Sanyo Chemical Co., Ltd.) Magnetic particles 60 parts by weight (T
Fet03. average particle size 0.3μm) polypropylene
3 parts by weight (Viscol 5 manufactured by Sanyo Chemical Co., Ltd.
50 P) Red dye 5 parts by weight (Orient chemical type RED-RR) After mixing the above raw materials and kneading with heat, cool and solidify.
After pulverization and classification, 3 parts by weight of polyaniline was added and mixed to obtain a magnetic color toner having a particle size of 4 to 44 μm. The electrical resistances are D and C.

It was 104Ω·1 at 100V/cm. Using the above magnetic color toner, a commercially available copier (Mita Kogyo Mae)
Copying was performed using CopyStar 600D), and a clear red image was obtained.

Example 2 Styrene acrylic copolymer 37 parts by weight (SBM-600 manufactured by Sanyo Chemical Co., Ltd.) Magnetic particles 55 parts by weight (r
Fe403. average particle size 0.3μm) polypropylene
3 parts by weight (Viscol 5 manufactured by Sanyo Chemical Co., Ltd.
50 P) Red dye 5 parts by weight (Orient chemical type RED-RR) After treating and classifying the above raw material in the same manner as in Example 1,
Add and mix 0.4 parts by weight of polyaniline to obtain a particle size of 5 to 20.
A μm magnetic color toner was obtained. In addition, electric resistance beam,
C, 4000V/cm and 10'4Ω・CWI. When copying was performed using a commercially available copying machine (FT4700 manufactured by Ricoh) using the above magnetic color toner, a clear red image was obtained.

Example 3 Styrene acrylic copolymer 82 parts by weight (SBM-600 manufactured by Sanyo Chemical) Polypropylene 3 parts by weight (Viscol 550P manufactured by Sanyo Chemical) Red dye 5 parts by weight (Orient Chemical RED-RR) Polyaniline 10 parts by weight Above materials was treated and classified in the same manner as in Example 1.2, and one particle size was 5 to 5.
A color toner of 15 μm was obtained.

The blow-off charge amount was -15 pc/g.

The above color toner was transferred to a ferrite carrier (manufactured by Hitachi Metals).
KBN-100 (particle size: 74 to 149 μm) was mixed to prepare a developer having a toner concentration of 4%.

Using this developer, use a commercially available copying machine (Konica UBix).
3000).

A clear red image was obtained.

In this example, an example was shown in which the toner particles were created using mechanical mixing and stirring means, but it is also possible to adopt a fluidized bed coating method in which the toner particles are made into a fluidized state and the surface is coated with a chromatic colorant. good.

In addition, in this example, r -Fe2 is used as the magnetic particle.
Although an example using O2 and magnetite is shown, magnetic particles other than those mentioned above may be used (or core particles containing or coated with magnetic particles may be used).

〔Effect of the invention〕

Since the present invention has the structure and operation as described above,
This has the advantage that it is possible to obtain clear color images with good color tone and high stability even when the environment changes.

Claims (1)

[Claims] (1) Color toner particles containing a chromatic colorant inside or on the surface of toner particles made of substantially white, gray or transparent resin, containing conductive fine particles made of polyaniline. Color toner particles characterized by: (2) The color toner particles according to claim (1), containing 5 to 20% by weight of conductive fine particles. (3) In color toner particles containing magnetic particles or attached to the surface, and containing a chromatic coloring agent inside or on the surface of the toner particles made of substantially white, gray, or transparent resin, electrically conductive material made of polyaniline Color toner particles characterized by having fine particles attached to their surfaces. (4) The color toner particles according to claim (3), wherein 0.1 to 4% by weight of conductive fine particles are attached.