JP2002067050A - Method for manufacturing composite layer of rubber material and fluorine-containing coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a composite layer of a rubber material and fluorine-containing coating capable of reducing an energy consumption without giving a heat aging to a layer of the rubber material without reducing adhesive properties of the layer of the rubber material and a film of the coating without increasing a man-hour. SOLUTION: The method for manufacturing the composite layer of the rubber material and the fluorine-containing coating comprises the steps of coating the fluorine-containing coating on a surface of the layer of an unvulcanized rubber material, heating to vulcanize the rubber material, and curing the fluorine-containing coating to manufacture the composite layer of the rubber material and the fluorine-containing coating. Thus, the vulcanizing of the rubber material and the curing of the fluorine-containing coating can simultaneously be conducted by one time heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite layer of a rubber material and a fluorine-based paint used in an intermediate transfer member of an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic technique, such as an electronic copying machine, a facsimile, a laser printer, etc., a toner image on the surface of an electrostatic latent image holding member is transferred to paper or the like via an intermediate transfer member. As a result, printing is performed.

FIG. 1 shows an example of an electrophotographic image forming apparatus in which an electrostatic latent image holding member 1 formed by a drum having a photoconductor layer on the surface is charged around a charging roll or the like. Means 2, an exposure optical system 3 using a semiconductor laser or the like as a light source,
A developing device 4 containing a toner, a cleaner 7, an eraser lamp 8, and the like are arranged. The intermediate transfer member 11 is formed by an intermediate transfer belt 11a stretched between a plurality of rolls 5. The intermediate transfer belt 11a is configured to contact the outer periphery of the electrostatic latent image holding member 1 and to be driven to travel. It is.

In this electrophotographic image forming apparatus, first, the surface of the electrostatic latent image holding member 1 is uniformly charged by the charging means 2 while rotating the electrostatic latent image holding member 1, and is used for copying. By irradiating the surface of the electrostatic latent image holder 1 with laser light by the exposure optical system 3 in accordance with an image signal from a document or the like, an electrostatic latent image is formed on the surface of the electrostatic latent image holder 1.
Next, toner is supplied from the developing device 4 to the electrostatic latent image formed on the surface of the electrostatic latent image holding member 1, and the electrostatic latent image is converted into a toner image. At this time, in the case of a color copying machine, the number of developing devices 4 corresponding to the color of the toner is used. Then, the toner image on the surface of the electrostatic latent image holding member 1 is electrostatically transferred to the surface of the intermediate transfer belt 11a, and finally,
The toner image is transferred onto a transfer material 6 such as paper fed while being in contact with the surface of the intermediate transfer belt 11a, and then the toner image is fixed on the surface of the transfer material 6 through a fixing process. Excess toner remaining on the surface of the electrostatic latent image holder 1 is removed by the cleaner 7, and the electrostatic latent image holder 1 is finally discharged and initialized by being irradiated with the eraser lamp 8. It is prepared for a series of operations as described above.

FIG. 2 shows another example of the electrophotographic image forming apparatus. An intermediate transfer member 11 has a composite layer composed of a rubber layer 13 of a rubber material and a coating 14 of a fluorine-based paint on the outer periphery of a metal core 12. 15 are formed by an intermediate transfer roll 11b in which the layers 15 are stacked. Other configurations are the same as those in FIG. 1 described above. The outer periphery of the intermediate transfer roll 11b is formed as a composite layer 15 in which the surface of a rubber layer 13 of a rubber material is coated with a coating 14 of a fluorine-based paint. The intermediate transfer belt 11a in FIG. The entire belt is formed as a composite layer in which the surface of the belt body is coated with a film of a fluorine-based paint.

By forming the intermediate transfer member as a composite layer having a rubber material layer and a fluorine-based coating film, elastic deformation can be obtained by the rubber material layer and the surface of the intermediate transfer member can be obtained. The releasability of the electrostatically attached toner, that is, good toner releasability, can be obtained by coating with a fluorine-based paint having a small surface friction coefficient, thereby improving the transfer efficiency to the transfer-receiving material. Such an intermediate transfer member is disclosed in JP-A-7-149448, JP-A-7-234592, JP-A-11-212374, and the like.

[0007]

In producing a composite layer of a layer of a rubber material and a coating of a fluorine-based paint as described above, conventionally, generally, a rubber material is first molded and then vulcanized to form a rubber material. After forming a layer, apply a fluorine-based paint to the surface of this rubber material layer by spraying, brushing, dipping, etc., air-dry at room temperature, preliminary drying, and then heat to cure the fluorine-based paint. By doing so, a film of a fluorine-based paint is laminated and integrated on the surface of the rubber material layer.

However, in this method, heating when curing the fluorine-based paint acts on the rubber material layer after vulcanization, and the rubber material layer may have an unnecessary heat aging effect. In addition, heating is required for vulcanization of the rubber material and curing of the fluorine-based paint, and there is a problem that energy consumption is large.

On the other hand, an intermediate transfer roll 11a as shown in FIG.
In the case of (1), after a rubber layer 13 of a rubber material is formed and vulcanized on the outer periphery of the cored bar 12, a fluororesin tube prepared in another step is covered on the outer periphery of the rubber layer 13 and shrunk by heating to obtain a rubber material. There is also a method of forming a composite layer 15 by laminating a coating 14 of a fluororesin tube on the layer 13 of FIG.

However, in this method, the number of steps is increased, such as the necessity of manufacturing a fluororesin tube in a separate step, which is disadvantageous in terms of cost, and the adhesion between the rubber material layer 13 and the fluororesin coating 14 is low. There was also a problem.

The present invention has been made in view of the above points, and has been made without increasing the number of steps, without reducing the adhesion between the rubber material layer and the fluorine-based paint film, and without reducing the rubber material layer. It is an object of the present invention to provide a method for manufacturing a composite layer of a rubber material and a fluorine-based paint, which can reduce energy consumption without giving a heat aging effect to the rubber.

[0012]

According to a first aspect of the present invention, there is provided a method for producing a composite layer of a rubber material and a fluorine-based paint, wherein a fluorine-based paint is applied to the surface of an unvulcanized rubber material layer and heated. And vulcanizing the rubber material and curing the fluorine-based paint.

The invention of claim 2 is characterized in that, in claim 1, an aqueous paint containing a copolymer of a fluororesin and a fluororubber is used as the fluoro paint.

A third aspect of the present invention is characterized in that, in the first or second aspect, a fluorine-based paint having a curing temperature of 200 ° C. or less is used.

The invention of claim 4 is characterized in that in any one of claims 1 to 3, chloroprene rubber or urethane rubber is used as the rubber material.

[0016]

Embodiments of the present invention will be described below.

In the present invention, chloroprene rubber, epichlorohydrin rubber, urethane rubber,
Silicone rubber, butadiene rubber, acrylonitrile
Butadiene rubber, styrene-butadiene rubber, and the like can be used. However, when the present invention is used for an intermediate transfer member of an electrophotographic image forming apparatus, chloroprene rubber often used as such an intermediate transfer member is suitable. Alternatively, urethane rubber is preferred. This rubber material can be used by adding ordinary additives. For example, sulfur, organic peroxides, crosslinking agents such as zinc oxide, aging inhibitors such as phenols, carbon black, reinforcing agents such as white carbon,
Fillers such as calcium carbonate and diatomaceous earth; plasticizers such as dioctyl sepate and dioctyl phthalate; and process oils such as paraffinic and naphthenic.

On the other hand, in the present invention, a fluorine-based aqueous latex paint obtained by dispersing a copolymer of a fluororubber and a fluororesin in water and / or alcohol to form a water-based dispersion can be used as the fluorine-based paint. Examples of the fluorine rubber used in the fluorine-based paint include copolymers of a fluorine-containing ethylenically unsaturated monomer and vinylidene fluoride, and examples of the fluorine resin include ethylene tetrafluoride and ethylene tetrafluoride-6 A fluorinated propylene copolymer or the like can be used. In the present invention, it is particularly preferable that the fluorine-based coating material is cured by heating at a relatively low temperature of 200 ° C. or less, for example, at a temperature of about 150 ° C. The curing temperature of a fluororesin alone is relatively high at 200 to 350 ° C., but by mixing a fluororubber with the fluororesin, the curing temperature can be set to a relatively low temperature of 200 ° C. or lower. Although the lower limit of the curing temperature is not particularly set, about 100 ° C. is a practical lower limit. The fluorine-based paint used in the present invention is preferably an aqueous paint as described above in consideration of environmental problems.

First, an unvulcanized rubber material is formed. At this time, if the intermediate transfer member is a roll, a rubber material is molded around the outer periphery of a core such as aluminum. When the intermediate transfer member is a belt, a rubber material sheet is wound around the outer periphery of a cylindrical mold in a cylindrical shape. Thereafter, a fluorine-based paint is applied to the outer peripheral surface of the unvulcanized rubber material. Methods for applying a fluorine-based paint to the surface of an unvulcanized rubber material include spray coating, brush coating, and dipping methods. However, since coating film unevenness directly affects the volume resistivity on the surface of the intermediate transfer body. It is preferable to apply uniformly. Spray coating is particularly preferred to obtain a uniform coating. The thickness of the film of the fluorine-based paint is preferably from 10 to 90 μm, more preferably from 10 to 30 μm, as a dry thickness.

After the fluorine-based paint is applied to the surface of the unvulcanized rubber material in this manner, the unvulcanized rubber material is vulcanized by heating. Standard vulcanization conditions for the rubber material are, for example, 153 ° C. × 20 minutes for chloroprene rubber and 160 minutes for urethane rubber.
C. x 20 minutes, and the temperature in the production line reaches 170C or more. Therefore, by heating when vulcanizing this unvulcanized rubber material, drying and curing of the fluorine-based paint can be performed at the same time. The curing process can be performed simultaneously, and the process can be simplified while sufficiently curing the fluorine-based paint, and the energy consumption can be reduced. As a result, the vulcanization of the rubber material and the drying / curing of the fluorine-based paint can be performed simultaneously. Does not needlessly act on the vulcanized rubber layer, and the rubber material layer is not aged by heat.

When the fluorine-based paint is cured at the same time as the rubber material is vulcanized, the functional group of the fluororesin portion of the fluorine-based paint reacts with the rubber material and adheres to the rubber material by a so-called pendant effect. And a composite layer in which a vulcanized layer of a rubber material and a film of a fluorine-based paint are laminated and integrated. Here, by using a mixture of a fluorine resin and a fluorine rubber as the fluorine-based paint, the curing temperature of the fluorine-based paint is set to 200 ° C.
Since the following relatively low temperatures can be set, the heating temperature for vulcanizing the rubber material and curing the fluorine-based paint is set to 200.
C. or less, and can prevent thermal deterioration of the rubber material due to heating at a high temperature. Further, by this heating, the surface modification effect of the coating film of the fluorine-based paint becomes more remarkable, and the effect of lowering the friction coefficient of the composite layer can be enhanced.

[0022]

Next, the present invention will be described specifically with reference to examples.

Example 1 A chloroprene polymer was masticated, and a vulcanizing agent, carbon black, a plasticizer, a processing aid, an antioxidant, etc. were added to 100 parts by mass of the chloroprene polymer, and the mixture was thoroughly kneaded. After that, using an extruder, a thickness of 1 m of A4 size based on chloroprene rubber was used.
m of unvulcanized rubber sheets.

Next, as a fluorine-based coating material, "DAIL latex G" manufactured by Daikin Industries, Ltd., which is a water-based coating material containing a copolymer of a fluorine resin and a fluorine rubber and having a solid content of 51% by mass.
Using "LS-213", the unvulcanized rubber sheet was applied to the surface of the unvulcanized rubber sheet by a spray method so that the dry film thickness became about 20 μm.

Thereafter, this is heated at 153 ° C. for 20 minutes, thereby vulcanizing the unvulcanized rubber sheet and drying and curing the fluorine-based paint film, and laminating the rubber layer and the fluorine-based paint film. An integrated composite layer was obtained.

(Example 2) An unvulcanized rubber sheet using a urethane rubber as a base material was produced in the same manner as in Example 1 except that a millable urethane polymer was used instead of the chloroprene polymer. And after that, after applying a fluorine-based paint in the same manner as in Example 1, by heating at 160 ° C. for 20 minutes, the unvulcanized rubber sheet is vulcanized and the film of the fluorine-based paint is dried and cured, A composite layer in which a rubber layer and a fluorine-based paint film were laminated and integrated was obtained.

Comparative Example 1 An unvulcanized rubber sheet based on chloroprene rubber was prepared in the same manner as in Example 1, and the unvulcanized rubber sheet was vulcanized by heating at 153 ° C. for 20 minutes. . Then, after applying the fluorine-based paint in the same manner as in Example 1, the coating of the fluorine-based paint is dried and cured by heating at 150 ° C. for 20 minutes,
A composite layer in which a rubber layer and a fluorine-based paint film were laminated and integrated was obtained.

(Comparative Example 2) An unvulcanized rubber sheet based on urethane rubber was prepared in the same manner as in Example 1, and the unvulcanized rubber sheet was vulcanized by heating at 160 ° C for 20 minutes. . After that, after applying the fluorine-based paint in the same manner as in Example 1, the coating of the fluorine-based paint is dried and cured by heating at 150 ° C. for 20 minutes, and the rubber layer and the fluorine-based paint film are laminated. An integrated composite layer was obtained.

With respect to the composite layers obtained in Examples 1 and 2 and Comparative Examples 1 and 2 as described above, the adhesion of the fluorine-based paint film and the coefficient of friction of the fluorine-based paint film were measured as follows. .

(Evaluation of Adhesive Strength of Fluorine Paint Film by Crosscut Tape Method)
After forming 100 squares and sticking an adhesive tape over the entire area of the squares and peeling it off, the layer of the fluorine-based paint-coated rubber material is determined by the residual ratio of the fluorine-based paint-coated squares. Was evaluated for adhesion to the surface. Table 1 shows the results.

(Measurement of the coefficient of friction of the surface of the fluorine paint film)
Stainless steel indenter (shape: w63mm x h63mm x t
6.3 mm, load 196 g) at a moving speed of 10 mm / sec
c and the coefficient of friction was measured by a detector. Table 1 shows the results.

[0032]

[Table 1]

As shown in Table 1, in each of the examples, a composite material having the same adhesive strength and surface friction coefficient of a fluorine-based paint film as in the conventional method was obtained.

[0034]

As described above, according to the method for producing a composite layer of a rubber material and a fluorine-based paint according to the first aspect of the present invention, a fluorine-based paint is applied to the surface of an unvulcanized rubber material layer and heated. And vulcanize the rubber material and cure the fluorine-based paint, so that the vulcanization of the rubber material and the curing of the fluorine-based paint can be performed simultaneously with a single heating, and the heat-aging of the rubber material layer The composite layer can be produced without giving any effect and with reduced energy consumption. Further, unlike the case where a fluororesin tube is separately formed and then covered with a rubber material layer, the number of steps is not increased, and the adhesion between the rubber material layer and the fluorine-based paint film is reduced. There is no one.

According to the second aspect of the present invention, since a water-based paint containing a copolymer of a fluorine resin and a fluorine rubber is used as the fluorine-based paint, the curing temperature of the fluorine-based paint can be lowered. It is possible to prevent the occurrence of environmental problems due to the use of a paint that does not use an organic solvent.

According to the third aspect of the present invention, as the above-mentioned fluorine-based paint, a curing temperature of 200 ° C. or less is used, so that the heating temperature for vulcanizing the rubber material and curing the fluorine-based paint is reduced. The temperature can be set to 200 ° C. or lower, and deterioration of the rubber material due to high-temperature heating can be prevented beforehand.

Further, according to the invention of claim 4, as the rubber material,
Since chloroprene rubber or urethane rubber is used, a composite layer suitable for an intermediate transfer member of an electrophotographic image forming apparatus can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating an example of an electrophotographic image forming apparatus.

FIG. 2 is a schematic view illustrating another example of the electrophotographic image forming apparatus.

[Explanation of symbols]

 Reference Signs List 11 intermediate transfer body 13 layer of rubber material 14 coating of fluorine-based paint 15 composite layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 7/04 CEQ C08J 7/04 CEQZ G03G 15/16 G03G 15/16 // B29K 19:00 B29K 19: 00 B29L 31:32 B29L 31:32 C08L 21:00 C08L 21:00 F-term (reference) 2H032 AA05 BA08 BA09 BA23 4D075 BB26Z DA15 DA20 DB35 DC27 EA06 EB16 EB53 4F006 AA04 AB19 BA11 CA01 DA04 EA05 4F100 AK17A AN02A BA02 CA03 CA04 CA06 CA13 EH46B EJ06 EJ08 EJ42 GB41 JB15A JL02 JM01B 4F203 AA16 AA45 AA46 AD18 AH04 DA11 DB01 DC01

Claims (4)

[Claims] 1. A rubber material and a fluorine-based paint, wherein a fluorine-based paint is applied to the surface of an unvulcanized rubber material layer, and the rubber material is cured by heating to cure the fluorine-based paint. A method for producing a composite layer. 2. The method for producing a composite layer of a rubber material and a fluorine-based paint according to claim 1, wherein an aqueous paint containing a copolymer of a fluorine resin and a fluorine rubber is used as the fluorine-based paint. 3. A fluorine-based paint having a curing temperature of 200
3. The method according to claim 1, wherein the temperature is less than or equal to ℃.
A method for producing a composite layer of a rubber material and a fluorine-based paint according to the above. 4. The method according to claim 1, wherein chloroprene rubber or urethane rubber is used as the rubber material.