JPH01281457A - Electrophotographic developing agent - Google Patents

Abstract

PURPOSE:To prevent sticking of components contained in transfer paper to the surface of a photosensitive body by arranging to cause sticking of colorless and transparent particles or white particles in a toner to a nonimaged part of the transfer paper. CONSTITUTION:A toner constituted of colored particles which stick to visualized parts, and colorless and transparent particles or white particles which are charged to reverse polarity to the colored particles and stick to unvisualized parts, is used. When an electrostatic latent image formed on the surface of a photosensitive body is developed with an electrophotographic developing agent contg. such toner, the colored particles in the toner stick to the visualized parts on the photosensitive body, and, on the other hand, colorless and transparent particles or white particles in the toner stick to unvisualized parts since they are charged to a reverse polarity to colored particles. Thus, the photosensitive body is prevented from direct contact with the transfer paper, and components in the transfer paper are prevented from sticking to the surface of the photosensitive body.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developer used for developing electrostatic latent images in electrophotography and electrostatic recording.

Conventional technology Conventionally, as an electrophotographic method, the US patent 2.297°6
Various methods are described in Japanese Patent Publication No. 91, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, etc., but in general, photoconductive substances are used to form a photoreceptor on a photoreceptor by various means. An electrostatic latent image is formed on the surface, and then the electrostatic latent image is developed using toner, and if necessary, the powder image is transferred to paper, etc., and then fixed by heating or, in some cases, solvent vapor, etc., to make a copy. ).

Examples of methods for visualizing electrostatic latent images using toner include the magnetic brush method described in U.S. Pat. No. 2,874,083, and the magnetic brush method described in U.S. Pat. Cascade development method and 2.22 of the same
The powder cloud method described in No. 1.776 is known.

As an electrophotographic developer, a pigment or dye such as carbon black or phthalocyanine blue is used as a coloring agent in a resin such as polystyrene, styrene-butadiene copolymer, or polyester.
The average particle size of the toner obtained by pulverizing to 1n is approximately the same as the toner particle size or 500/! Generally used are particles of glass steel, iron, nickel, ferrite, etc., or a mixture thereof with a carrier coated with various resins.

Problems to be Solved by the Invention However, with conventionally used developers, if the copying operation is continued for a long time, the photoreceptor and the transfer paper come into direct contact in areas that are not visible during transfer, causing the transfer paper to deteriorate. There is a problem in that the components inside stick to the surface of the photoreceptor and cause image disturbance.

The present invention was made with the aim of solving the above-mentioned problems in conventional developers. Therefore, an object of the present invention is to establish direct contact between the photoreceptor and the transfer paper, occupying the non-visualized area; : By avoiding the components in the transfer paper on the surface of the photoconductor, it is possible to create a stable () and clear image without any disturbance even after long-term use. It is necessary to provide the following.

Means for Solving the Problems The above-mentioned object of the present invention is to use colored particles as a toner to be attached to visible areas, and toner particles that are charged to the opposite polarity to the colored particles and to be attached to non-visualized areas and non-image areas. )
This can be achieved by using colorless transparent or white particles for adhesion to the surface.

To explain the present invention in detail, the aged particles, which are the first component of the toner, are used to convert an electrostatic latent image formed on a photoconductor or an electrostatic recording medium (hereinafter referred to as a photoconductor) into a visible image. Toners commonly used in electrophotographic developers can be used, and there are no particular limitations on these toners.

The colored particles are mainly composed of a coloring agent and a binder resin. As the binder resin, any general thermoplastic resin can be used, but specifically, styrene such as styrene and chlorostyrene; ethylene, butylene, butylene, isobutylene, etc. Monoolefins; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate; methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate , butyl methacrylate, butyl methacrylate, esters of α-methylene aliphatic monocarboxylic acids such as dodecyl methacrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; vinyl methyl ketone, vinyl hexyl getone, vinyl Isobropenylke 1
Examples include homopolymers or copolymers of vinyl ketones such as . Polymers such as styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene, and polypropylene can be used. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin, and waxes.

In addition, the colorant is not particularly limited,
Any known material can be used. For example, carbon black, nigrosine dye, aniline blue, calcoyl blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oki (narrate, lamp black, rose bengal, C, 1, Pigment Red 48.1, C, 1, Pigment Red 122, C,
L Pigment Red 57; 1, C, 1, to Pigment 1 Yellow 97, C, I, Pigment Yellow 12
, C0■, Pigment Blue 15.1, C,1, Pigment Blue 153 chopsticks are representative examples.

The colored particles used in the present invention have an average particle diameter of less than about 309M, preferably 3 to 20#l.
It is marketed in the range of .

Fine silica powder or the like can also be externally added to the colored particles. Silica (more specifically, silica fine particles or 1 to 3 organic groups directly bonded to silicon through a silicon-carbon bond as described in Japanese Patent Publication No. 16219/1983) Examples include silicon disulfide particles having surface silicon atoms, in which silicon atoms are chemically bonded via silicon-dispersion-silicon bonds.The silica fine particles may be subjected to a hydrophobic surface treatment.

Additionally, a cleaning aid may be externally added.

Examples of cleaning aids include, but are not limited to, polyvinylidene fluoride powder and polymethyl methacrylate powder.

As the colorless transparent or white particles necessary for the second component of the toner, a colorless transparent or white fine powder exhibiting a chargeability opposite in polarity to that of the colored particles may be used. Specifically, for example, particles made of only the resins exemplified in the binder resin used for the colored particles, or colorless and transparent charged particles to impart the resin with the property of being charged in the opposite polarity to the colored particles. Examples include those in which a control agent is added internally or externally. As such a colorless and transparent charging agent, known agents can be used, such as quaternary ammonium salts such as cetylpyridium chloride, organic boron compounds such as tetraphenylboron salts, and hydrophobic agents. Fine silica powder or the like can be used.

Furthermore, as colorless transparent or white particles, 5102, Al
103, Tl01ZrlO, CaCO3, BaSO4
Particles consisting only of white metal oxides or metal salts can be used.

The particle size of the colorless transparent to white particles in the present invention is:
It is set in the range of 0.1 to 30 μm, preferably 0.5 to 20 #l.

In the developer of the present invention, the blending ratio of colored particles, which is the first component of the toner, and colorless transparent or white particles, which are the second component of the toner, is such that the latter is from 0.1 to 1 toner.
It is preferable to set it within a range of 20i♀%.

If the latter blending ratio is lower than 0.1% by weight, a sufficient effect will not be exhibited, and if it is higher than 20%, the image density may be lowered, which is not preferable.

The developer of the present invention can be produced by mixing the above-mentioned colored particles and the colorless transparent to white particles, which are vinyl chloride copolymers, in a suitable mixing vessel such as a blender.

The developer of the present invention is used as a so-called two-component developer that uses a toner and a carrier. That is, the developer prepared as described above is mixed with carrier particles to form a two-component developer.

As the carrier particles, particles having an average particle size of up to 500 JIJTi are used, and various known particles such as iron, niragel, cobalt, iron oxide, ferrite, glass beads, and granular silicone are used.

Further, it is also possible to use particles whose surfaces are coated with a coating agent such as a polyester resin, an acrylic resin, or a silicone resin.

Function: When an electrostatic latent image formed on the surface of a photoreceptor is developed using the electrophotographic developer of the present invention, colored particles in the toner are visualized on the photoreceptor in correspondence with the electrostatic latent image. On the other hand, since the colorless transparent or white particles in the toner are charged to the opposite polarity to the colored particles, they will adhere to the non-image areas. Therefore, if development is performed using the electrophotographic developer of the present invention, direct contact between the photoreceptor and the transfer paper can be avoided, and components in the transfer paper can be prevented from adhering to the surface of the photoreceptor. . When transferring and fixing the visualized toner image on the surface of the photoreceptor, the colorless transparent or white particles have opposite polarity to the colored particles, so they are transferred from the non-image area. There is no. Further, even if a portion of the image is transferred and fixed, it will not have any adverse effect on the image quality because it is colorless and transparent or white.

Therefore, it becomes possible to stably obtain images without disturbance for a long time.

Example Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 Graft polymer of propylene polymer and styrene-n-butyl methacrylate copolymer 34 parts styrene-n-
Butyl methacrylate chestnut 1 polymer 36 parts Rhodamine dye 10 parts by weight The above components were melt-kneaded, then finely pulverized and classified to obtain particles with an average particle size of 12 μm. To 100 parts by weight of these particles, 2.0 parts by weight of sensitized fine aluminum powder with a particle size of 0.02Ni was added and mixed in a Henschel mixer to form red particles (η.(Toner first component) Styrene- n-Butyl methacrylate copolymer 98 parts by weight Bontron E-
84 (manufactured by Orient Co., Ltd.) 2 parts by weight After melt-kneading the above components, finely pulverize and classify to obtain an average particle size of 10 thr
White particles of r were obtained. (Second Toner Component) 97 parts by weight of the first toner component and 3 parts by weight of the second toner component were mixed using a V-type mixer, and the toner was mixed.

Styrene-n- in a ferrite core with an average particle size of 100#l
A developer was prepared by mixing 100 parts by weight of the butyl methacrylate copolymer coated carrier with 3.5 parts of the above toner.

Using this developer, an electrophotographic copying machine (FX-2700 modified machine, manufactured by Fuji Xerox 11) was used at 30°C and 80°C.
When I did a copy test under %Rtl environment, 20
．． Even after continuous copying of 000 sheets, no image disturbance occurred.

Comparative Example 1 A developer was prepared in exactly the same manner as in Example 1, except that the second toner component was omitted. Using this developer, images were distorted in a continuous copy test of 20,000 sheets in an environment of 30℃, 80%R by an electrophotographic copying machine (FX-2700 modified machine, manufactured by Fuji Xerox). occurred.

Example 2 Styrene-n-butyl methacrylate copolymer 93 parts by weight Carbon black 5 parts by weight Cetylpyridinium chloride 2 parts by weight After melt-kneading the above components, finely pulverize,
It was classified and black particles with an average particle size of 12
First component> Polyester with an acid value of 10 is finely pulverized, and the average particle size is 10.
A powder of pm was obtained. (Toner second component) The above toner first component
The components and the second toner component were mixed in the same manner as in Example 1 to obtain a toner, and a developer was prepared in the same manner as in Example 1 using a carrier.

Using this developer, an electrophotographic developing agent ("X-2700 modified machine") was used for 25 minutes at 30°C and 80% R11.
When a continuous copy test of 000 sheets was conducted, it was possible to obtain clear images with no image disturbance.

Example 3 A developer was prepared in the same manner as in Example 1 using 98 parts by weight of the red particles in Actual Dust Example 1 and 1 part by weight of 2 parts of silicon oxide powder having an average particle size of 3 mm.

Using this developer, an electrophotographic copying machine (FX-2700 modified machine) was used for 20.
When a continuous copy test of 000 sheets was conducted, it was possible to obtain clear images with no image disturbance.

Effects of the Invention Since the electrophotographic developer of the present invention has the above structure,
The colorless transparent or white particles in the gutter adhere to the non-image area, and as a result, the photoreceptor and transfer paper no longer come into direct contact, which prevents components in the transfer paper from adhering to the photoreceptor surface. It can be prevented.

In addition, when transferring and fixing the toner particles visualized on the surface of the photoreceptor, the colorless transparent or white particles have the opposite polarity to the colored particles, so they are not transferred from the non-image area. Even if some of the particles are transferred and fixed, since the particles are colorless and transparent or white, there will be no adverse effect on the quality of the copied image.

Therefore, when the electrophotographic agent of the present invention is used for a long time, it is possible to produce 1 q of stable and clear images without disturbance.

Claims (2)

[Claims] (1) For electrophotography, characterized by comprising colored particles to be attached to areas to be visualized, and colorless transparent or white particles charged to the opposite polarity to the colored particles and to be attached to non-image areas. developer. (2) The electrophotographic developer according to claim 1, wherein the colorless transparent or white particles have a particle size of 0.1 μm or more and 30 μm or less.