JPS61185753A - Electrophotographic sensitive endless belt - Google Patents

Abstract

PURPOSE:To reduce friction on the surface at the joint of an endless belt and to enhance durability by forming a protective film including a specified solid lubricant on the surface of the joint for joining both ends of a photosensitive belt. CONSTITUTION:The protective film 4 contg. at least one of solid lubricants of graphite, MoS2, WS2, graphite fluoride, polytetrafluoroethylene, polytrifluoroethylene, polyamide, polyacetal, and polyethylene, is formed on the surface of the joint 3 of the photosensitive endless belt 1, 2 formed by joining both ends of the photosensitive sheet. Such a protective film 4 is pre pared by dispersing said solid lubricant particles into a solvent soln. of resin or rubber, and coating the surface of the joint 3 with the obtained coating fluid, and drying it. Since the protective film 4 contg. such a solid lubricant is formed on the surface of the joint 3 of the electrophotographic endless belt to reduce friction, friction between the belt and each kind of members arranged around the photosensitive belt at the time of sliding contact with each other is weakened, and its durability can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an endless belt photoreceptor for electrophotography.

[Prior art]

With the miniaturization of electrophotographic copying machines, those in which a sheet-like photoreceptor is looped (endless belt-like) have become widely adopted. Further, when flash exposure is employed in a high-speed electrophotographic copying machine, the use of a belt-shaped photoreceptor is advantageous since a flat area is required at the exposed area.

By the way, the ideal belt-shaped photoreceptor (usually made of an organic semiconductor) is seamless (non-bonded type), but in general, photoreceptors are formed on a conductive-treated support (including those carrying a photoconductive layer). An endless belt is used by cutting and joining a photoreceptor sheet provided with a conductive layer. However, the reality is that such photoreceptors have not yet been satisfied in terms of strength, flatness, cost, and the like.

That is, the above-mentioned bonding is usually performed by adhesive 31 as shown in FIG. 2 or by high-frequency bonding (welding) 32 as shown in FIG. Although strength is obtained, some protrusions are unavoidable in this joint 3 (31, 32), and therefore l) cleaning members, sealing members, etc. that come into sliding contact with the surface of the photoreceptor are This is because the stiff particles constantly hit the joint, causing damage to each other, and (ii) Damage to the joint may lead to undesirable situations such as linear peeling of the photosensitive layer itself in the driving direction. .

Since such a situation is a fatal problem for electrophotographic photoreceptors, sometimes measures are taken to cover the joint surface with resin (protective layer 41), as shown in FIG. However, even with these measures, the tendency to damage cleaning members, sealing members, etc. has not been significantly reduced.

In FIG. 2, l represents a conductive support, 2 represents a photosensitive layer, and the arrow represents the direction of movement of the electrophotographic photoreceptor during copying.

〔the purpose〕

The present invention provides an endless belt electrophotographic photoreceptor in which the occurrence of the above-mentioned disadvantages is minimized.

[Horizontal]

The present invention provides an endless belt electrophotographic photoreceptor formed by joining both ends of a sheet-like photoreceptor, in which the surface of the joint 3 contains graphite, molybdenum disulfide, tungsten disulfide, graphite fluoride, polytetrafluoroethylene, It is characterized by forming a protective film containing at least one solid lubricant selected from trifluoroethylene, polyamide, polyacetal, and polyethylene.

Incidentally, as a result of various studies on the above-mentioned problems of conventional endless belt electrophotographic photoreceptors, the present inventor found that
It has been found that good results can be obtained if the protective layer on the surface of the joint 3 (31, 32) is formed of a resin containing a specific solid lubricant. The present invention was completed based on this knowledge.

The conductive support 1 and the photoconductive layer (photosensitive layer) 2 are exactly the same as conventional ones. For example, for the photosensitive layer 2, an organic photoconductive substance is used since the photoreceptor of the present invention is an endless belt.

The protective film 3 is composed of a resin or rubber in which a solid lubricant is added and dispersed.

The resin or rubber is not particularly limited as long as it is solvent soluble, but from the viewpoint of strength, polyester 5 polycarbonate 1, polyamide.

Preference is given to using phthyral, polyurethane, cellulose, butylene-styrene copolymer, butadiene rubber, 21-lyl rubber. Two or more of these may be used in combination if necessary.

Solid lubricants include graphite and molybdenum disulfide.

Tungsten disulfide, graphite fluoride, polytetrafluoroethylene,
Examples include polytrifluoroethylene, polyamide (nylon (3, nylon 66), polyacetal, and polyethylene. Among them, the former five types (・P) are particularly preferable in terms of friction resistance and strength. This solid lubricant is It is of the form
The particle size is 01 to 14 m (04 to 0.6 m is particularly suitable for leprosy).

The mixing ratio of these solid lubricants and resins is 5/100.
~50/100 or so, preferably 10/100~30/
100 is appropriate.

Therefore, in the photoreceptor of the present invention, a protective film forming liquid prepared by adding solid lubricant particles to a solution of the above resin in a solvent and stirring and dispersing the mixture is applied to the joints of the electrophotographic photoreceptor. 3. It can be easily created by applying it to the surface and drying it. The thickness of the protective film may be adjusted as necessary.

Smooth endless belt conveyance by coating with a protective film can also be applied to continuously driven endless belts 1 in general (e.g., paper conveyance belts of electrophotographic copying machines and other paper conveyance belts). .

[Effect] According to the present invention, the joint surface of the Entresspel 1-electrophotographic photoreceptor, in which both ends of the helical photoreceptor of the sheet 1 are brought into contact with each other, is made low in f or 1, so that the electrophotographic photoreceptor The force of sliding contact with various surrounding members is weakened, and durability is significantly improved.

[Brief explanation of drawings]

FIG. 1 shows an enlarged cross-sectional view of the joint portion of an endless belt electrophotographic photoreceptor in which both ends of a sheet 1 ribbon-shaped photoreceptor are joined together according to the present invention, and FIGS.
The figure is an enlarged sectional view of a joint portion of a conventional electrophotographic photoreceptor. 1... Conductive support 2... Photosensitive layer 3... Joining part 4... Protective film amount 1 Figure 2 Figure 4 (4)

Claims (1)

[Claims] 1. In an endless belt photoreceptor formed by joining both ends of a sheet-like photoreceptor, graphite, molybdenum disulfide, tungsten disulfide, graphite fluoride, polytetrafluoroethylene, polytrifluoroethylene are added to the surface of the joint. 1. An endless belt photoreceptor for electrophotography, comprising a protective film containing at least one solid lubricant selected from polyamide, polyacetal, and polyethylene.