JPS58102949A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To enhance the mechanical strength, cleanability, etc. by forming an insulating layer having 1X10<11>-5X10<14>OMEGA.cm surface resistance value and made of thermoplastic resin contg. a lubricant and a surfactant contg. fluorine on the photoconductive layer. CONSTITUTION:Thermoplastic resin contg. 0.5-90wt% lubricant such as polyethylene, polytetrafluoroethylene, polyvinyl chloride or talc and 0.5-50wt% surfactant contg. fluorine is prepared. An insulating layer made of said thermoplastic resin and having 1X10<11>-5X10<14>OMEGA.cm surface resistance value and 2- 40mum thickness is formed on a photoconductive layer to obtain a receptor. The preferred primary particle size of the lubricant is <=10mum, especially <=5mum. The surfactant contg. fluorine is a surfactant having a highly fluorinated long- chain alkyl group in the molecule.

Description

[Detailed description of the invention] The present invention relates to an electrophotographic photoreceptor.

Electrophotographic photoreceptors have various configurations in order to obtain predetermined characteristics or depending on the type of electrophotographic process to which they are applied. Typical electrophotographic photoreceptors include a photoreceptor in which a photoconductive layer 1- is formed as an image-retaining layer on a support, and a lamination of a photoconductive layer and an insulating layer thereon as a support 1-. Photoreceptors are widely used.

The photoconductor, which is composed of a support and a photoconductive layer, is used for image formation by the most common electrophotographic process, that is, charging, one-time exposure, development, and, if necessary, transfer. In addition, regarding the photoreceptor equipped with insulation 1-, this insulation 1-
is provided for the purpose of protecting the photoconductive layer, improving the mechanical strength of the photoreceptor, improving the dark decay characteristics, or being applied to a specific electrophotographic process.

No. 15446, Japanese Patent Publication No. 46-3713, Japanese Patent Publication No. 42-2391, which describe a photoreceptor having such an insulating layer or an electrophotographic process using a photoreceptor having an insulating layer.
Publication No. 0, Special Publication No. 43-24748, Special Publication No. 42-
It is described in Japanese Patent Publication No. 19747, Japanese Patent Publication No. 36-4121, etc.

As an electrophotographic photoreceptor, the IIjIgl contrast tends to be low immediately after the start of copying due to the applied electrophotographic method, and there is a phenomenon in which the density gradually increases, or conversely, a phenomenon in which the density is initially high and then gradually decreases. This depends on the charging polarity of the surface of the photoreceptor and the environment, especially humidity, after the previous coffee finish. Further, the surface of the photoreceptor is required to have good cleaning properties, mechanical strength, developer adhesion, mold releasability, ozone resistance, and the like.

The main object of the present invention is to provide a photoreceptor that satisfies the above-mentioned drawbacks and the conditions required for a photoreceptor surface layer.

The present invention is characterized in that the surface resistance value of the photoreceptor having an insulating layer on the photoconductive layer is in the range of 1X10'' to 5X1014 Ω·1.The resistance value limit of the insulating layer is determined by the surface resistance of the previous copy. The electrical charge is reduced quickly.The insulating layer contains a surfactant that disperses the lubricant.As the lubricant, a powder with a lubricating effect is appropriately used.Typical lubricants include e-yu, polyethylene, and polyethylene. tetrafluoroethylene,
Examples include polyethylene terephthalate, polyvinylidene fluoride, polyvinyl chloride, and gold stearate that are generally insoluble in solvents. The particle size of the lubricant is 10μ in -order particle size.
Below, those in the range of 5μ or less are particularly good. Jun I
The amount of the 'll agent added is set appropriately, but is usually 0.5~
90% by weight, particularly 5 to 50% by weight is preferred.

As the surfactant, a heptadium surfactant is used. Fluorine surfactants are surfactants that contain highly fluorinated long-chain alkyl groups in their molecules. Typical examples of fluorosurfactants include C, F, 80.・N RCHtCooKC, Fty
80. , NRCH,CH,0(cH,C1-1,0)
nH (n-5, 10, 15) Cm Fty 80t N (CHmCHsOHs O
I() *C@FB RO((J(ICHIO) n)
I n = 5~20CI8Fms(RO)n n
=5-20CB1FBB(R-0)nRn=5-20, etc.

R represents an alkyl group such as methyl, ethyl, globyl, butyl, or an alkyl group such as phenyl, naphthyl, or the like.

The fluorosurfactant is preferably contained in an amount of 0.5 to 50% by weight, particularly 1 to 30% by weight.

The thickness of the insulating layer is set appropriately, but is usually 40 to 2μ,
In particular, a range of t120 to 4μ is suitable.

? A suitable thermoplastic resin for forming the layer is polyethylene acrylic acid. Polyethylene acrylic acid is usually made into an aqueous solution in which the H of the carboxylic acid is NLKi6[ with ammonia water, and after coating, it is replaced with H again during heat drying to form a stable film.

Vinegar-vinyl copolymer (product name: UMCH, manufactured by UCC)
15 parts of the mixture was dispersed in a methyl ethyl ketone solvent, coated by a dipping method onto a raw aluminum cylinder which had been finely dispersed by roll milling, and dried at 80° C. for 15 minutes to form a photoconductive layer with a thickness of 40 μm. I made two other drums using the same method.

Each drum is marked as ``H'' and ``Q''.

First (8) The surface of the drum is covered with polyester film 25.
A μ-thick heat shrink tube was treated with hot water at 95° C. for 15 seconds to form an insulating layer. Next, the (El drum) was immersed in an anhydrous solution of polyethylene acrylic 1!Il (trade name: EAA, UCC 1#), pulled up at a rate of 5 min/min, and
A heat treatment was performed at .degree. C. for 20 minutes to form an insulating layer with a thickness of 25 .mu.m.

Ni (for q drum polyethylene acrylic acid 10
0 parts of polytetrafluoroethylene (trade name: Lublon L2.Daikin Industries IEi), 1 part of a fluorine surfactant (trade name: FC431, manufactured by Sumitomo 3M) were dispersed in ammonia water, and further finely powdered with a sand mill. After dispersing, apply by dipping method and heat treat at 80℃ for 20 minutes.
9. Form and form an insulating layer with a thickness of 5#. Obtained Prisoner, (Dragon, (
Regarding the Q photoconductor VC, - Suita DC charging, secondary AC static electricity removal, simultaneous self-lighting, then full-surface irradiation, development transfer, and cleaning are repeated, and then at the end of copying, AC static electricity removal is performed, and the surface is O charged to remove the previous latent charge. Apply electrophotographic method to erase scratches, wait 1 hour, and repeat 20 copies in a row.
When the images were taken, the image density was low on the first sheet of the prison drum, but a proper image was obtained on the 20th sheet. The surface resistance was 5 x 10'' Ω4 or more. (B), (C) The surface resistance of the drums was 8 x 10'', and there was no difference in density between the 1st and 20th sheets, and proper images were obtained.

This result is due to the fact that the amount of charge retention in the insulating layer of the drum is not sufficient, whereas (B), (Q), the Ill charge retention force is small, so the 0 surface position immediately attenuates. Also, (BJ had surface scratches after 10,000 sheets of durability, and black lines were seen on the image) (Q drum rfiso
Even oooo sheets were good.

Sender: Canon Co., Ltd.

Claims (1)

[Claims] (1) An electrophotographic photoreceptor having an insulating layer on a photoconductive layer and having a surface resistance value in the range of 1X10" to 5X10" Ω·1.