JPS6126666B2 - - Google Patents

Description

Detailed Description of the Invention The present invention is used in electrophotography to transfer a toner image on a photoconductor obtained by development onto a transfer paper by applying pressure from behind the transfer paper overlaid on the toner image. Concerning the pressure transfer method.

A binder is required for effective pressure transfer. In the conventional pressure transfer method, a pressure-sensitive binder is coated on one side of the transfer paper.
The toner was embedded in this binder layer. The binder must have a tackiness that does not adhere to the surface of the photoreceptor and that can attract the toner. Therefore, transfer paper coated with such a binder becomes expensive.

The pressure transfer method according to the present invention uses a photoreceptor with a non-adhesive layer such as a thermoplastic transparent film on the surface of the photoconductive layer, and the non-adhesive layer is different from the toner by using a non-melting wax or the like as a binder. The toner is mixed in with the toner, and the visible image developed with this toner is transferred to transfer paper by applying pressure.

According to the method of the present invention, ordinary transfer paper can be used as the transfer paper, and fixing can be performed at the same time as the transfer, and the transfer is completed completely.
There is no need to clean the photoreceptor, and furthermore, a constant transferred image can be obtained regardless of the conductivity or magnetism of the toner, thus eliminating transfer defects, especially in times of high humidity.

It is therefore an object of this invention to provide an improved pressure transfer method using conventional transfer paper.

Hereinafter, one embodiment of the present invention will be described with reference to the attached drawings. The photosensitive drum 1 is formed by coating a conductive cylindrical body 2 made of aluminum or the like with a photoconductive layer 3, and then coating a non-adhesive layer 4 thereon. The photoconductive layer 3 is preferably made of an organic semiconductor or selenium, and zinc oxide is not preferable because the photoreceptor characteristics change due to pressurization. The non-adhesive layer 4 is preferably a thermoplastic transparent film made of polyester, polypropylene, polyethylene, or the like. Further, although the thickness of the non-adhesive layer 4 does not affect transfer, it does affect image formation to some extent, so a thinner one is preferable.

The surface of the photosensitive drum 1 is uniformly charged by a corona charger 5, and an original image is irradiated onto this surface by an exposure optical system 6, thereby forming an electrostatic latent image thereon. The formed electrostatic latent image is visualized by the developing device 7. A developer 8 is stored in the developing device, and is attracted to a rotating magnetic roller 9, so that the surface of the photoreceptor is rubbed by this developer layer. Developers include two-component developers consisting of a carrier and toner, and one-component developers consisting only of toner. In either case, in this invention, the toner that forms a visible image Adhesive is mixed in. As the binder, a binder that is insoluble or incompatible with the non-adhesive layer on the surface of the photoreceptor is used, and wax-based binders are particularly preferred.

The toner image on the photoreceptor obtained by development is transferred by inserting a transfer paper 10 between the surface of the photoreceptor 1 and a pressure roller 11 made of metal or hard resin that rotates in pressure contact with the surface of the photoreceptor 1. It is superimposed on the transfer paper 10. At the same time, when the toner containing the binder is pressurized by the pressure roller 11, the binder becomes pressure-sensitive and becomes sticky. One side facing the toner is a plain transfer paper, and the other side is a non-adhesive layer that does not melt the toner's binder, so all sticky toner is easily transferred. It adheres to the paper 10 and is embedded in the surface of the transfer paper 10 by the pressure of the pressure roller 11. In this way, the toner image is transferred and fixed simultaneously.

Almost all of the toner on the photoreceptor is transferred to the transfer paper, so there is no residual toner on the photoreceptor. Removes charge.

Example An organic semiconductor was used for the photoconductive layer of the photoreceptor, and a polyester layer with a thickness of 100 μm was provided thereon. A one-component magnetic toner was used as the developer. The particle size is 20 μm, 100 parts by weight of polyethylene wax is used as a binder, and the particle size is 0.2 μm as magnetic powder.
100 parts by weight of triiron tetroxide (m) and 10 parts by weight of carbon black as a coloring agent were used.

When the present invention was carried out using such a photoreceptor and toner, the toner was completely transferred. By the way, when we investigated the reflection density (Macbeth value) of the photoreceptor surface before development, after development, and after transfer, we found that they were 0.20, 1.70, and 0.20, respectively.
This numerically demonstrated complete toner transfer.

Since this invention is a pressure transfer method that focuses on the configuration of a photoreceptor and toner, there are no particular limitations on the electrostatic latent image forming process and the developing process.

[Brief explanation of the drawing]

The figure is a schematic diagram for explaining the method according to the invention. DESCRIPTION OF SYMBOLS 1... Photoreceptor, 3... Photoconductive layer, 4... Non-adhesive layer, 11... Pressure roller.

Claims (1)

[Claims] 1. An electrostatic latent image is formed on a photoreceptor having a transparent non-adhesive layer on the surface of the photoconductive layer, and the electrostatic latent image is formed using a toner to which a non-melting binder is added. A pressure transfer method characterized in that a transfer paper is placed on the visible image on the photoreceptor, and pressure is applied from behind with a pressure roller to transfer the visible image onto the transfer paper. .