JPH11338175A - Endless belt for electrophotographic device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt for an electrophotographic device capable of rapidly and accurately executing an adhesion stage and stably traveling even in long-term use by rapidly obtaining required initial adhesive strength; and a method for producing the endless belt with good productivity. SOLUTION: In the method for producing the endless belt 1 by forming flexible film-like base material 2 in an annular state and providing a guiding rib 3 made of elastic material along the side edge of the inner periphery of the material 2; a recessed part is formed on the adhesive surface of the rib 3 so as to obtain rugged structure, and the rugged part is coated with reaction type adhesive so as to be stuck, whereby the endless belt is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless belt used in an electrophotographic apparatus and a method for manufacturing the same. More specifically, the present invention relates to an endless belt for an electrophotographic apparatus having a rib for preventing meandering and capable of running stably for a long period of time, and a method for manufacturing the same with high productivity.

[0002]

2. Description of the Related Art In recent years, electrophotographic image forming methods have been widely used in copiers, printers and the like, since high quality images can be obtained immediately. As the core photoreceptor, an endless belt-shaped electrophotographic photoreceptor is widely used because it has a flexible property and a high degree of freedom in arrangement in an apparatus. The endless belt-shaped photoreceptor 20 is formed by laminating a metal layer on a synthetic resin film and forming a photoreceptor sheet on which a photoreceptor layer such as a charge generation layer and a charge transport layer is formed into predetermined dimensions. As shown in FIG. 5, both ends are fused and formed into an annular shape using an ultrasonic sealing machine or the like, and used as an image forming mechanism. Reference numeral 21 denotes a charging device, 22 denotes an exposure optical system, 23 denotes a developing device, 24 denotes a cleaner, 25 denotes a transfer charger, and 26 denotes a transfer sheet.

In an electrophotographic apparatus, an intermediate transfer belt 30 is used as shown in FIG. The intermediate transfer belt 30 is for temporarily transferring an image developed by the developing device 23 onto the photosensitive drum 20a onto the intermediate transfer belt 30 and transferring the image to the paper 26 again. Thus, the endless belt-shaped electrophotographic photosensitive member 20 or the intermediate transfer belt 30 has a problem that meandering occurs during traveling. For this reason, as shown in FIG. 7, the endless belt such as the endless belt-shaped photoreceptor 20 is joined with a rib material made of a rubber-like flexible material along a side edge of the back surface of the annular base material 20 for guiding. The ribs 31 are formed, and the ribs 31 are fitted into the grooves 33 of the roll 32 and run to prevent meandering.

However, the guide rib 31 is made of a soft material because it is repeatedly bent every time around the outer periphery of the drive roll 32. To improve the productivity, the soft material is used for the base material. A technique for efficiently forming the ribs on the side edges is required. Conventionally, as a method for forming a rib, a mold plate having a long groove-shaped mold recess penetrating on the front and back sides is stacked on the back surface of the film-like base material, and the long groove is filled with silicon rubber or the like and the rib-like material is directly formed on the film-like material Is formed.

However, when the rib-like body is directly formed,
Until the filled rib material is hardened, the template must be fixed so as not to move, so that the production efficiency cannot be increased. Further, a method of separately forming a rib body and joining the formed rib body to a film-like body using a double-sided pressure-sensitive adhesive tape or an adhesive is also adopted. But,
When a double-sided pressure-sensitive adhesive tape is used, there is a problem that the adhesive strength is apt to be reduced due to long-term use.

When bonding is performed using a reaction-curable adhesive such as a room-temperature-curable silicone rubber-based adhesive, it is necessary to increase the thickness of the adhesive layer in order to obtain adhesive strength. When the adhesive layer is made thicker, the curing reaction progresses slowly, and it is necessary to hold the initial adhesive strength so as not to cause a shift until the adhesive strength reaches a predetermined value, which is about the same as when a rib body is directly formed on a film-like body. There is a problem that time is required and production efficiency is low.

[0007]

SUMMARY OF THE INVENTION The present invention makes it possible to quickly and accurately perform a bonding step by quickly obtaining a required initial bonding strength in bonding a film body and a rib body. An object of the present invention is to provide an endless belt for an electrophotographic apparatus which runs stably even during long-term use, and a method for manufacturing the same with high productivity.

[0008]

SUMMARY OF THE INVENTION The present invention has been made as a result of intensive studies from such a viewpoint, and a flexible film-shaped substrate is formed in a ring shape.
In an endless belt in which a guide rib made of a flexible material is joined along a side edge of an inner periphery thereof, a concave portion is formed on a bonding surface of the guide rib to form an uneven structure, and a reactive adhesive is formed on the uneven structure portion. An endless belt for an electrophotographic device, characterized by being coated and adhered, and a flexible film-shaped substrate formed in a ring shape,
In a method of manufacturing an endless belt in which a guide rib made of a flexible material is joined along a side edge of an inner periphery thereof, a concave portion is formed in an adhesive surface of the guide rib to form a concave-convex structure, and a reactive mold is formed on the concave-convex structure portion. An object of the present invention is to provide a method for producing an endless belt for an electrophotographic apparatus, wherein an adhesive is applied and adhered.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An endless belt 1 of the present invention is formed by forming a flexible film-shaped substrate 2 in a ring shape as shown in FIG.
Note that, in the present invention, a sheet and a film are used as synonyms, and identification by a film thickness is not performed. To describe an example in which the endless belt 1 is used for an electrophotographic photoreceptor, a photoreceptor sheet is used as a flexible film-shaped substrate 2, and the photoreceptor sheet has a photosensitive layer formed on a conductive support. As the conductive support, those obtained by laminating a metal layer on a biaxially stretched film are preferable. As the material of the biaxially stretched film, linear polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and polyolefin resins such as polyethylene and polypropylene And polyvinyl chloride resin, but a linear polyester resin, particularly polyethylene terephthalate, is preferred from the viewpoint of mechanical strength and dimensional stability.

[0010] The thickness of the resin film is usually 50
About 150 μm. Examples of the metal of the metal deposition layer constituting the conductive support include copper, nickel, zinc, and aluminum, and among them, aluminum is preferable. The thickness of the metal deposition layer is usually 400 to
About 1000 °, and the vapor deposition on the resin film is:
The metal is heated and melted by electrothermal heating, in-beam evaporation,
This is performed by a known vapor deposition method such as an ion plating method.
Further, as the metal layer, a metal foil such as an aluminum foil and a nickel foil, or a laminated film in which these metals are laminated can be used. In this case, the metal foil is preferably 5 μm or less.

A known barrier layer, which is usually used, can be provided between the conductive support and the photosensitive layer.
As the barrier layer, for example, polyvinyl alcohol,
An organic layer such as casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide and polyamide is used, and if necessary, inorganic particles such as titanium oxide and aluminum oxide may be added. The photoreceptor layer may be a single-layer type containing a charge generating substance and a charge transporting substance, or may be a function-separated type in which a charge generating layer and a charge transporting layer are laminated. Hereinafter, a function-separated type photoconductor will be described as an example.

As the charge generating substance used in the charge generating layer, any of known charge generating substances can be used. Examples include various organic pigments such as pyranthrone and cyanine, dyes, and the like. Among them, metals such as metal-free phthalocyanine, copper indium chloride, gallium chloride, tin, oxytitanium, zinc, and vanadium, or oxides and chlorides of phthalocyanines are preferred.

Examples of the binder for the charge generation layer include polyacetals such as polyvinyl butyral, polyvinyl acetate,
A resin such as a phenoxy resin can be used. The thickness of the charge generation layer is usually 0.1 μm to 1 μm, preferably 0.15 μm to 0.6 μm. The content of the charge generating substance used here is in the range of 20 to 300 parts by weight, preferably 50 to 200 parts by weight, based on 100 parts by weight of the binder resin. As the charge transporting material in the charge transporting layer, various low-molecular compounds such as various pyrazoline derivatives, oxazole derivatives, hydrazone derivatives, stilbene derivatives, and arylamines can be used.

A binder resin is blended with these charge transporting materials. Preferred binder resins include, for example, polymethyl methacrylate, polystyrene, vinyl polymers such as polyvinyl chloride, and copolymers thereof, polycarbonate, polyester, polysulfone, polyether, polyketone, phenoxy, epoxy, silicone resin, and the like. These partially crosslinked cured products are also used. Further, the charge transport layer may contain various additives such as an antioxidant and a sensitizer. The thickness of the charge transport layer is
It is good to use with a thickness of 10 to 40 μm, preferably 10 to 30 μm.

The photosensitive sheet thus obtained is cut into a predetermined size and then joined at both ends. As a joining method,
Even in the case of bonding with an adhesive, a heat sealing bar or a fusion device using ultrasonic waves can be used. As will be described later, a guide rib may be provided before joining both ends. When the endless belt of the present invention is used as an intermediate transfer belt, the resin composition of the flexible film-shaped substrate 2 is not limited to any of a thermoplastic resin, a thermosetting resin, or rubber. Since a thermoplastic resin or a thermoplastic elastomer can be continuously extruded, it is desirable in terms of production cost.

As the thermoplastic resin, polyethylene (high density, medium density, low density, linear low density), propylene ethylene block or random copolymer, rubber or latex component such as ethylene / propylene copolymer rubber, styrene -Butadiene rubber, styrene-butadiene-styrene block copolymer or its hydrogenated derivative, polybutadiene, polyisobutylene, polyamide,
Polyamide imide, polyacetal, polyarylate,
Polycarbonate, polyphenylene ether, modified polyphenylene ether, polyimide, liquid crystalline polyester, polyethylene terephthalate, polysulfone, polyethersulfone, polyphenylene sulfide,
Polybisamide triazole, polybutylene terephthalate, polyetherimide, polyetheretherketone, acryl, polyvinylidene fluoride, polyvinyl fluoride, ethylene tetrafluoroethylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer , Tetrafluoroethylene perfluoroalkyl vinyl ether copolymer, polytetrafluoroethylene, fluororubber, alkyl acrylate copolymer, polyester ester copolymer, polyether ester copolymer, polyether amide copolymer, olefin copolymer Polymers, polyurethane copolymers, or a mixture thereof are used.

Particularly preferred resins for the intermediate transfer belt are polyvinylidene fluoride, polyvinyl fluoride, ethylene tetrafluoroethylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer, and tetrafluoroethylene perfluoropolymer. Alkyl vinyl ether copolymers, fluororesins such as polytetrafluoroethylene and fluororubbers are also preferred to prevent contamination from toner and the like, and polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyester ester copolymers, polyethers An ester-based thermoplastic resin or a thermoplastic elastomer such as an ester copolymer is preferable because the electric resistance value of the electric resistance is stable with little change in electric resistance.

Further, a conductive filler may be added to these materials to adjust the electric resistance. As conductive filler, carbon black, graphite, carbon fiber,
It is preferable to use at least one selected from metal powders, conductive metal oxides, organometallic oxides, organometallic compounds, organometallic salts, conductive polymers, and the like, or a mixture of several kinds of these. Among them, carbon black is particularly preferred.
Examples of the carbon black include carbon black such as acetylene black, furnace black, and channel black. Acetylene black excellent in dispersibility is preferable so as not to impair the appearance of the film.

The amount of carbon black varies depending on the type of carbon black. In the case of acetylene black, it is preferably 3 to 25 parts by weight based on 100 parts by weight of the thermoplastic resin, and in the case of Ketjen black, it is 1 to 10 parts by weight. Parts by weight are preferred. If it is less than the above range, the conductivity is poor, and if it is more than the above range, the appearance of the product is deteriorated and the material strength is unfavorably reduced. The resin composition may contain various additional components to be added to a usual resin composition as long as the object of the present invention is not impaired. Such components include antioxidants, lubricants, release agents, and the like.

These intermediate transfer belt materials can be obtained by forming a flat sheet using a T-die or an annular die, cutting the flat sheet into predetermined dimensions, and joining both ends. For the joining, the means described for the endless belt-shaped photoconductor can be used. Alternatively, a seamless tube can be formed by forming a cylindrical shape by an internal mandrel method using an annular die and cutting the cylindrical shape into a predetermined length. As shown in FIG. 1 along the side edge on the inner peripheral surface of the base material 2 having a predetermined width thus obtained,
The narrow strips formed in advance are joined to form the guide ribs 3.

The material of the guide rib 3 is flexible,
There is no particular limitation as long as the material has bending resistance.
Elastomers having a hardness of 60 degrees or less, preferably 50 degrees or less according to K7215 (A type) are preferable, and specifically, neoprene rubber, urethane rubber, butyl rubber, silicone rubber and the like are preferable. Among them, silicone rubber is preferable because of its adhesiveness to the base material 2, electric insulation, environmental resistance such as moisture resistance, solvent resistance, ozone resistance and heat resistance. As silicone rubber,
One-component cold curing type is desirable from the viewpoint of workability, shapeability, damage to the substrate, etc., and further, from the dimensional accuracy of the obtained guide,
It is preferable that the material has a semi-fluidity such that it is not deformed by gravity in a shaped state before curing. As a solvent capable of dissolving the silicone rubber before curing, an alcohol-based solvent is desirable because it does not damage the belt substrate in terms of safety. Specifically, ethyl alcohol and isopropanol are used.

The cross-sectional shape of the guide rib 3 is not particularly limited, but is generally square, rectangular, triangular, or trapezoidal as shown in FIG. Thus, in the present invention, the convex portion 3a and the concave portion 3b are formed on the bonding surface of the guide rib 3, and the bonding surface has an uneven structure. Recess 3b
The cross-sectional structure can be any cross-sectional shape without any particular limitation, and can be a rectangular, rectangular, triangular, or concave portion enlarged inside as shown in FIG. 2 (D). Recess 3b
Is generally 0.1 mm or more, preferably 0.2 to
It is about 3 mm. The recess 3b is generally formed in a groove shape continuous in the length direction, but may be formed in an intermittent shape according to the purpose. Also, as shown in FIG.
More than this can be provided.

As shown in FIG. 3, it is also preferable to attach a double-sided pressure-sensitive adhesive tape 4 to the bonding surface of the convex portion 3a of the guide rib 3 because the bonding strength can be increased. The double-sided pressure-sensitive adhesive tape 4 may be attached to the entire surface of the projections 3a, 3a of the guide rib 3 as shown in FIG. 3 (A), or may be partially attached as shown in FIG. 3 (B). You may stick it. When joining the guide ribs 3 to the film-shaped base material 2, a reactive adhesive 5 is applied to the bonding surface of the guide ribs 3 as shown in FIG. 4, and the concave portions 3b are filled with the adhesive 5. And at the same time apply to the adhesive surface of the projection 3a.

As the adhesive, a reactive adhesive is used, and a urethane adhesive, an acrylic adhesive, a silicone adhesive, an epoxy adhesive, or the like can be used. The guide ribs 3 filled with the adhesive 5 are adhered along both side edges of the back surface of the film-shaped base material 2 to form the guide ribs 3 by curing the adhesive. Substrate 2
The guide ribs 3 may be joined to the base member 2 after joining both ends of the base member 2 to form an annular shape. Alternatively, the guide ribs 3 may be attached to the flat base member 2 before joining the two end portions. After joining, both ends of the base material 2 may be joined to form an annular shape.

According to the present invention, since the adhesive is applied to the concave portion 3b of the guide rib 3 in a state filled with the adhesive, the adhesion becomes strong, and the adhesive on the surface of the convex portion 3a has a small film thickness. Therefore, a predetermined initial adhesive strength can be quickly obtained. When the double-sided pressure-sensitive adhesive tape 4 is applied as shown in FIGS. 3A and 3B, even before the adhesive is cured, the base material 2 and the ribs for the guide are bonded by the double-sided pressure-sensitive adhesive tape 4. Since the guide ribs 3 are fixed, the guide ribs 3 can be joined at an accurate position without being shifted. The endless belt 1 of the present invention includes an endless belt-shaped photoconductor 20 shown in FIG.
6, or as the intermediate transfer belt 30 shown in FIG. 6, and can be driven by using a roll 32 having a groove 33 shown in FIG. 7, or a roll 35 having tapered rings 34, 34 as shown in FIG. .

[0026]

The present invention will be described in more detail with reference to the following examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. In the following examples, “parts” means “parts by weight”. Example 1 In 1.6 parts of oxytitanium phthalocyanine showing the strongest peak at 27.3 ° at a flag angle (2θ ± 0.2 °) of powder X-ray diffraction spectrum by Cu-Kα ray, 1.6 parts of oxytitanium phthalocyanine was added.
-30 parts of propanol was added, and the mixture was pulverized by a sand grind mill for 6 hours and subjected to a fine dispersion treatment. The dispersion obtained here was mixed with 8 parts of a 5% methanol solution of polyvinyl butyral (trade name: # 6000-C, manufactured by Denka Co., Ltd.) and the exemplified polyester resin (2) (weight average molecular weight 7.8 × 1).
0 ³ ) was added to a mixed solution of 8 parts of a 5% methanol solution, and further diluted with methanol to finally prepare a dispersion having a solid content of 3.0%.

Next, this dispersion was applied on a biaxially stretched polyester film having a thickness of 75 μm on a vapor-deposited aluminum surface by a bar coater so that the film thickness after drying was 0.4 μm. Was provided. Next, on this charge generation layer, 60 parts by weight of a hydrazone compound [A] shown below as a charge transport material was added.

[0028]

Embedded image

0.5 parts by weight of the following cyano compound:

[0030]

Embedded image

8 parts by weight of 2,6-ditert-butylhydroxytoluene (BHT) and, as a binder,
A solution prepared by dissolving 100 parts by weight of a polycarbonate resin (“NOVAREX” (trademark) 7030A, manufactured by Mitsubishi Chemical Corporation) in 1,000 parts by weight of 1,4-dioxane is applied by a film applicator, and the film thickness after drying is 17 μm. The charge transport layer was provided so that On the other hand, the cross section is shown in FIG.
3 mm × 1 mm rectangular parallelepiped as shown in FIG.
A mold plate having a mold recess having two parallel 2 mm concave portions was filled with silicone rubber (SE9155 manufactured by Toray Dow Corning Silicone Co., Ltd.) and cured to form a narrow strip-shaped guide rib. The same silicone rubber as described above was applied to the adhesive surface, filled in the recesses, and applied to the adhesive surface.

This was adhered along both side edges of the photoreceptor sheet. After standing for 10 minutes, the adhesive hardened, and it did not slip off with a slight force. The photosensitive member sheet to which the guide ribs were bonded was fused at both ends by an ultrasonic sealing machine to obtain an endless belt-like photosensitive member. This was filled in a commercially available color electronic copier and subjected to a copy test of 60,000 sheets, but no color shift occurred.

COMPARATIVE EXAMPLE 1 The same operation as in Example 1 was performed except that a flat surface was formed without forming a concave portion on the joining surface of the guide rib. As a result, 20 minutes after the guide ribs were attached to the substrate, the adhesive was still insufficiently cured, and peeling and displacement occurred with a slight force. It took 35 minutes to cure to the extent that no displacement occurred.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of an endless belt of the present invention.

FIG. 2 is a longitudinal sectional view showing various examples of guide ribs used in the present invention.

FIG. 3 is a longitudinal sectional view showing another example of a guide rib used in the present invention.

FIG. 4 is a longitudinal sectional view of a guide rib when an adhesive is applied.

FIG. 5 is a side view showing an endless belt-shaped photoconductor.

FIG. 6 is a side view showing the intermediate transfer belt.

FIG. 7 is a partially cutaway perspective view showing a roll for driving an endless belt.

FIG. 8 shows another example of a roll for driving an endless belt.
Part notch side view.

[Explanation of symbols]

 Reference Signs List 1 endless belt 2 base material 3 guide rib 3a convex portion 3b concave portion 4 double-sided pressure-sensitive adhesive tape 5 adhesive 20 endless belt-shaped electrophotographic photosensitive member 30 intermediate transfer belt 32, 35 roll

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 21/00 352 G03G 21/00 352

Claims (6)

[Claims] 1. An endless belt in which a flexible film-shaped base material is formed in an annular shape and guide ribs made of a flexible material are joined along side edges of an inner periphery thereof. A concave portion is formed in the concave and convex portion to form a concave-convex structure, and a reactive adhesive is applied to and bonded to the concave-convex structure portion. 2. The endless belt for an electrophotographic apparatus according to claim 1, wherein the endless belt is an endless belt-shaped electrophotographic photosensitive member. 3. The endless belt for an electrophotographic apparatus according to claim 1, wherein the endless belt is an intermediate transfer belt of an electrophotographic apparatus. 4. A method for manufacturing an endless belt in which a flexible film-shaped base material is formed in a ring shape and guide ribs made of a flexible material are joined along side edges of an inner periphery thereof. A method for producing an endless belt for an electrophotographic apparatus, characterized in that a concave portion is formed on an adhesive surface of (1) to form an uneven structure, and a reactive adhesive is applied to the uneven structure portion and bonded. 5. The method according to claim 4, wherein the reactive adhesive is a silicon-based adhesive. 6. The method for producing an endless belt for an electrophotographic apparatus according to claim 4, wherein the double-sided pressure-sensitive adhesive tape is attached to at least a part of the convex portion of the guide rib bonding surface.