JPH06102788A - Production of fixing roll - Google Patents

Abstract

PURPOSE:To obtain excellent softness and heat conductivity and to obtain high picture quality of copy images without impairing smoothness of the surface of the fixing roll. CONSTITUTION:The production process of a fixing roll includes processes of a process to prepare a silicone rubber compsn. essentially consisting of silicone rubber, a process to prepare fluorine contained rubber compsn. containing 3-45 pts.wt. filler based on 100 pts.wt. of fluorine-contained rubber, a process to make a filler in the fluorine-contg. rubber compsn. <=1mum average particle size, a process to form a first elastic layer 2 by using the silicone rubber compsn. on the outer peripheral surface of a core body 1, and a process to form a second elastic layer 3 by using the fluorine-contained rubber compsn. on the outer peripheral surface of the first elastic layer 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a fixing roll used in electrophotographic copying machines, printers and the like.

[0002]

2. Description of the Related Art Conventionally, a fixing roll used in an electrophotographic copying machine, a printer or the like has a silicon rubber layer formed on the outer peripheral surface of a core metal (shaft), and a filler on the outer peripheral surface of the silicon rubber layer. A material having a fluororubber layer formed of a fluororubber material in which is dispersed is used.

[0003]

In the above fixing roll, in order to improve the image quality of the copied image, the fixing roll is provided with flexibility so that the contact area between the copy paper and the fixing roll is increased, and It has been attempted to improve the fixing property on copy paper. Therefore, the fluorine rubber layer of the fixing roll has a higher hardness than that of silicone rubber, and therefore it is desired to be formed into a thin film. In addition, since a heater is arranged on the core metal and the toner is heated and pressure-bonded by the heat, from the viewpoint of thermal conductivity from the core metal to the fixing roll surface,
It is desired to form the fluororubber layer into a thin film. However, when the fluororubber layer is formed into a thin film, the filler dispersed in the fluororubber layer affects the surface of the fixing roll, impairs the smoothness of the surface of the fixing roll, and as a result, the obtained copy image quality deteriorates. There is a problem.

The present invention has been made in view of the above circumstances, and does not impair the smoothness of the fixing roll surface.
It is an object of the present invention to provide a method for producing a fixing roll which has excellent flexibility and thermal conductivity and is capable of imparting a high quality copied image.

[0005]

In order to achieve the above object,
The method of manufacturing the fixing roll of the present invention includes a step of preparing a silicon rubber composition containing silicon rubber as a main component, and 3 to 65 parts by weight per 100 parts by weight of fluororubber (hereinafter abbreviated as "part").
Part of the fluororubber composition containing a filler in a ratio of 1 part, a step of refining the filler in the fluororubber composition to an average particle size of 1 μm or less, and the silicone rubber on the outer peripheral surface of the shaft body. A step of forming a first elastic layer using the composition; and a step of forming a second elastic layer using the fluororubber composition on the outer peripheral surface of the first elastic layer. Take the configuration of being.

[0006]

That is, the present inventors have aimed to develop a method for producing a fixing roll capable of forming a thin film of a fluororubber layer, which is the outermost layer of the fixing roll, without impairing the smoothness of the surface of the fixing roll. Repeated research. As a result, as the outermost layer forming material, when the filler dispersed in fluororubber was made finer to have an average particle size of 1 μm or less and the content ratio of the filler was set to a specific ratio, the fluororubber layer was formed into a thin film. Also found that a fixing roll having a smooth surface can be produced without being affected by the above-mentioned filler and reached the present invention.

Next, the present invention will be described in detail.

In the method of manufacturing the fixing roll of the present invention, the shaft body, the silicon rubber composition containing silicon rubber as the main component which is the first elastic body layer forming material, and the filling which is the second elastic body layer forming material. A fluororubber composition containing an agent is used.

The shaft body is not particularly limited, and a core metal made of a solid metal body or a metal cylindrical body having a hollow hollow inside is used.

Silicon rubber, which is a material for forming the first elastic body layer formed on the outer peripheral surface of the shaft body, is not particularly limited, and conventionally known ones can be used.

As a material for forming the first elastic body layer, heat resistant rubber such as ethylene propylene rubber, acrylic rubber, or fluorosilicone rubber can be used, if necessary, in addition to silicone rubber.

As a material for forming the second elastic body layer formed on the outer peripheral surface of the first elastic body layer, fluorocarbon rubber and carbon black as a filler having an average particle size of 1.0 μm or less and a receiving material are used. A fluororubber composition containing an acid agent dispersed therein is used.

Examples of the above-mentioned fluororubber include binary vinylidene fluoride type rubber, ternary vinylidene fluoride type rubber, tetrafluoroethylene-propylene type rubber, fluorophosphazene type rubber and the like, which may be used alone or in combination of two or more kinds. Used.

The carbon black dispersed in the second elastic layer-forming material is not particularly limited, and conventionally known ones can be used. Fluorine rubber 1
It is preferable to set the range of 0 to 50 parts with respect to 00 parts.

Examples of the acid acceptor dispersed in the second elastic layer forming material are MgO, PbO, Ca (OH) ₂ ,
Examples thereof include ZnO and CaO, which may be used alone or in combination of two or more. Fluorine rubber 100
It is preferable to set the range of 3 to 15 parts with respect to the parts.

The total amount of the carbon black and the acid acceptor mixed in the filler is 3 to 65 relative to 100 parts of the fluororubber.
It is necessary to set within the range of the section. That is, when the compounding amount of the filler is less than 3 parts, vulcanization is inhibited and a satisfactory vulcanization degree cannot be obtained, and when it exceeds 65 parts, the amount of the filler is too large and the smoothness of the roll cannot be maintained. Is.

Further, as the material for forming the second elastic layer, a vulcanizing agent in addition to the fluororubber and the filler having a specific particle size,
A vulcanization accelerator and a vulcanization accelerator activator can be appropriately mixed.

The vulcanizing agent is bisphenol AF.
And the like, and amine-based vulcanizing agents such as N, N′-dicinnaminilidene-1,6-hexanediamine and the like.

Examples of the vulcanization accelerator include organic phosphonium salts and the like.

The method for producing the fixing roll of the present invention is carried out using the above materials, for example, as follows. That is, first, a vulcanizing agent and a coloring agent are mixed with silicon rubber, and they are mixed and stirred using a roll, a kneader, etc. to prepare a silicon rubber composition. Next, the first elastic layer is formed on the surface of the metal shaft (core bar) by extrusion molding using the above silicone rubber composition. The surface of the obtained first elastic body layer is preferably smoothed by polishing to have a surface roughness of 1 μm or less. On the other hand, fluorocarbon rubber, carbon black, acid acceptor, vulcanizing agent,
If necessary, a vulcanization accelerator is mixed and kneaded with a roll, a kneader, etc., and a solvent is added to this mixture, which is mixed and stirred to prepare a coating solution of the fluororubber composition. In this case, the concentration is preferably set in the range of 5 to 25% by weight (hereinafter abbreviated as "%"). The obtained coating liquid is dispersed by a fine pulverizer to make the average particle diameter of the above filler finer to 1 μm or less. The coating solution in which the filler is made fine is
To uniformly coat the surface of the elastic layer by dipping, roll coating, spray coating, etc. and dry it, and heat vulcanize it to obtain a fixing roll having a structure as shown in FIG. You can In the figure, 1 is a core metal, 2 is a first elastic layer, and 3 is a second elastic layer.

Examples of the fine pulverizer used for the fine treatment of the above filler include a sand mill and a three roll mill. The conditions for the refining treatment are appropriately determined depending on the fine pulverizer to be used, and when a sand mill is used, for example, 3
Filler has an average particle size of 1 after processing at 000 rpm for 5 hours.
It is miniaturized to less than μm.

Examples of the solvent used for preparing the coating solution of the fluororubber composition include methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), methyl acetate, ethyl acetate and isoamyl acetate.
Used alone or in combination of two or more.

As described above, the filler dispersed in the fluororubber layer which is the second elastic layer 3 is made finer to have an average particle size of 1 μm or less, and the content ratio of the filler is set to 10%.
By setting it to 3 to 65 parts with respect to 0 part, it becomes possible to form the above-mentioned fluororubber layer into a thin film having a thickness of, for example, 30 μm or less without impairing the smoothness of the surface of the fixing roll. Thermal conductivity is imparted to the fuser roll. Specifically, the first elastic layer 2 has a thickness of 1 to
Within the range of 5 mm, the second elastic layer 3 has a thickness of 10 to 30 μ.
It is preferably set within the range of m.

[0024]

As described above, according to the method of manufacturing the fixing roll of the present invention, the step of preparing a silicone rubber composition containing silicon rubber as a main component and 3 to 100 parts of fluororubber are used.
A step of preparing a fluororubber composition containing a filler at a ratio of 45 parts, a step of refining the filler in the fluororubber composition to an average particle size of 1 μm or less, and the above silicon on the outer peripheral surface of the shaft body. The method further comprises a step of forming a first elastic body layer using the rubber composition, and a step of forming a second elastic body layer using the fluororubber composition on the outer peripheral surface of the first elastic body layer. It takes the structure of. Therefore, the fluororubber layer, which is the second elastic layer, can be formed into a thin film having a thickness of 30 μm or less, for example, without impairing the smoothness of the surface of the fixing roll. That is, the fixing roll manufactured by the manufacturing method of the fixing roll of the present invention has excellent smoothness,
Since it has flexibility and thermal conductivity, it is excellent in the fixing property of the toner to the copy paper, and a high quality copy image can be obtained. Also, it is not easily scratched by passing the paper and has excellent durability. Furthermore, by forming the fluororubber layer in a thin film, it is possible to suppress the amount of expensive fluororubber used,
Cost reduction can be achieved.

Next, examples will be described together with comparative examples.

[0026]

Examples 1 to 7 and Comparative Examples 1 to 3 An aluminum cored bar was used as the shaft body. The silicon rubber layer which is the first elastic layer was formed according to the method described above. That is, first, a vulcanizing agent and a coloring agent are mixed with silicon rubber, and the roll,
A silicone rubber composition was prepared by mixing and stirring using a kneader or the like. Next, using the obtained silicon rubber composition, a silicon rubber layer having a thickness of 3 mm was formed on the outer peripheral surface of the aluminum cored bar by extrusion molding.

The fluororubber layer, which is the second elastic layer, was formed according to the above-mentioned method with the materials and the compounding ratios shown in Tables 1 and 2 below. First, fluororubber, acid acceptor,
Add carbon black and vulcanizing agent in the ratio shown in the table,
It was kneaded using a roll, a kneader, or the like. MEK / MIBK mixed solvent [mixing ratio (weight ratio) 8/2] was added to this mixture so as to have a concentration of 10%, mixed and stirred, and the results are shown in Tables 3 and 4 below by a sand mill (3000 rpm). Dispersion was carried out at the indicated time to prepare a fluororubber composition coating liquid. Then, the cored bar on which the silicone rubber layer is formed is dipped in the obtained coating liquid for coating, then pulled up and dried, and then heat vulcanized to form a fluororubber layer having a thickness of 20 μm. A fixing roll as shown in was prepared.

[0028]

[Table 1]

[0029]

[Table 2]

With respect to each fixing roll thus obtained, the smoothness of the surface of the fixing roll, the vulcanization degree of the fluororubber and the average particle size of the filler were measured and evaluated. The results are shown in Tables 3 and 4. The relationship between the roll gloss and the average particle size of the filler is shown in FIG. The above characteristics were measured and evaluated according to the following methods.

[Smoothness of Fixing Roll Surface] In order to evaluate the smoothness of the fixing roll surface, the glossiness of the fixing roll surface (hereinafter abbreviated as “roll gloss”) was measured. The roll gloss is obtained by fixing the glossiness of the surface of the fixing roll to the fixing roll 6 by fixing the glossiness measuring device 4 to the fixing roll 6 with a fixing jig 5 as shown in FIG. The reflectance was measured and expressed as a percentage (%) when the glossiness of the mirror surface was 100. In addition, the glossiness measuring device shown in FIG.
Shown in. In FIG. 3, 7 is a light source, 8 is a fixing roll surface, and 9 is a light receiver. In the above-mentioned glossiness measuring device, it is assumed that the opening S _{1 of the} light source 7 is at the focal position of the lens L ₁ ,
When a mirror surface is placed at the position of the fixing roll surface 8, the image of S ₁ forms a clear image at the center of the opening S ₂ of the light receiver 9. The incident angle θ ₁ is an angle formed by a line connecting the center of the opening S _{1 and} the center of the lens L ₁ (principal point of the lens) and the normal line of the fixing roll surface 8. The acceptance angle θ ₂ is an angle formed by a line connecting the center of the opening S _{2 and} the center of the lens L ₂ (principal point of the lens) and the normal line of the fixing roll surface 8. Opening angle α ₁ , α ₂
Is an angle extending the openings S ₁ and S ₂ at the positions of the lenses L ₁ and L ₂ . The optical axes of the incident side and the light receiving side are the surface 8 of the fixing roll.
Shall intersect. Since the roll gloss has a correlation with the image quality of the obtained copy image, it is possible to evaluate the image quality of the copy image obtained by measuring the roll gloss, and if the roll gloss is 60% or more. If
The obtained copy image has high image quality.

[Vulcanization Degree of Fluorine Rubber] Since a roll having a low degree of vulcanization dissolves in MEK, the surface of the roll was wiped with a white cloth soaked with MEK, and the degree of contamination of the cloth was judged. ◯ indicates that the cloth is not stained, and x indicates that the cloth is soiled.

[Average Particle Size of Filler] The average particle size of the filler was measured using a laser diffraction type particle size distribution measuring device (LA-500 manufactured by Horiba, Ltd.).

[0034]

[Table 3]

[0035]

[Table 4]

From Table 3 above, the average particle size of the filler is 1 μm.
The roll gloss of the fixing rolls of the following example products are all 60% or more, and it can be seen that a high quality copied image can be obtained. On the other hand, the roll gloss of the fixing roll of the comparative example in which the average particle size of the filler exceeds 1 μm is 60%.
It can be seen that the obtained copy image is bad.

[Brief description of drawings]

FIG. 1 is a sectional view of a fixing roll manufactured by a manufacturing method of a fixing roll of the present invention.

FIG. 2 is a schematic view of a state in which the glossiness measuring device is fixed on a fixing roll by a fixing jig.

FIG. 3 is a schematic view showing a glossiness measuring device for measuring roll gloss.

FIG. 4 is a curve diagram showing the relationship between the average particle size of the filler and roll gloss.

[Explanation of symbols]

 1 core metal 2 1st elastic body layer 3 2nd elastic body layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location B29K 83:00 (72) Inventor Kazunori Toyama 3600 Tokai Rubber Industry, Tohoku, Toyama Rubber, Komaki City, Aichi Prefecture Within the corporation

Claims (1)

[Claims] 1. A step of preparing a silicon rubber composition containing silicon rubber as a main component and a fluororubber composition containing a filler in a proportion of 3 to 65 parts by weight relative to 100 parts by weight of the fluororubber. A step of refining the filler in the fluororubber composition to an average particle size of 1 μm or less, and a step of forming a first elastic layer on the outer peripheral surface of the shaft body using the silicon rubber composition. And a step of forming a second elastic layer using the fluororubber composition on the outer peripheral surface of the first elastic layer.