JP2001302906A - Elastic rubber member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elastic rubber member having an increased Young's modulus of elasticity and yet keeping a low hardness. SOLUTION: Provided is an elastic rubber member made from a filler compounded rubber material, wherein one side in the direction of thickness is a low-hardness layer 12A which is relatively lowly hard because it is substantially free from the filler, and the other side is a high-hardness aggregation layer 11A which is contiguous to the low-hardness layer and is relatively hard because the filler is aggregated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to a cleaning blade used for charging, removing and cleaning a transfer drum and a transfer belt of an electronic copying machine or the like, and a transfer belt used for transferring a recording medium. The present invention relates to an elastic rubber member used for the like.

[0002]

2. Description of the Related Art Conventionally, an elastic rubber member is used for a cleaning blade and a transport belt of an image forming apparatus, for example, a copying machine, a printer, or a composite OA apparatus having these functions.

Here, the conventional cleaning blade for an electronic copying machine must be slid on a photoreceptor at a predetermined pressure. For example, a structure in which an elastic rubber member is joined to the tip of a metal leaf spring material with an adhesive and pressed by the spring force of the leaf spring material, or a structure in which a spring that presses the cleaning blade toward the photoconductor is provided. Are known.

With such a structure, a pressing force higher than a predetermined value can be obtained. However, there is a problem that even if the pressing force is too large, the photosensitive member is damaged, and there is a problem that the installation of the blade becomes complicated.

There is also a proposal to increase the contact force by increasing the Young's modulus of the elastic rubber member. However, if the Young's modulus is to be increased, the rubber hardness also increases, and there is a problem that desired cleaning characteristics cannot be obtained.

[0006]

In order to obtain desired rubber hardness and Young's modulus by bonding a low-hardness rubber layer and a high-hardness rubber layer, a PET film or the like is used as a sheet of an elastic rubber member. Backed by a higher Young's modulus,
Alternatively, an elastic rubber member in which a core is inserted to increase the Young's modulus has been proposed. However, any of these methods has a problem in that the manufacturing process is troublesome and the cost is increased.

On the other hand, a conventional conveying belt for an electronic copying machine is for conveying a recording medium such as paper, and an elastic rubber member having a ring shape has been used. The durability of such a conveyor belt needs to be improved due to the complicated and high-speed conveyance route accompanying the downsizing of the apparatus.

For this reason, there has been proposed an elastic rubber member formed of a high-hardness rubber material to improve the Young's modulus and increase the durability. However, such a high-hardness elastic rubber member has a friction coefficient. Therefore, there is a problem that the transfer force is lowered and the transfer force is reduced.

In view of such circumstances, an object of the present invention is to provide an elastic rubber member having a high Young's modulus while maintaining low hardness.

[0010]

According to a first aspect of the present invention, there is provided an elastic rubber member made of a rubber material containing a filler, wherein the filler is provided on one side in the thickness direction. It becomes a low hardness layer of relatively low hardness that is not substantially contained, and the other side is formed continuously with the low hardness layer, and the filler aggregates to form a relatively high hardness aggregate layer. The elastic rubber member.

A second aspect of the present invention is the elastic rubber member according to the first aspect, wherein the rubber material is a thermosetting rubber.

A third aspect of the present invention is the elastic rubber member according to the second aspect, wherein the rubber material is formed of polyurethane or silicone rubber.

A fourth aspect of the present invention is the elastic rubber member according to any one of the first to third aspects, wherein the elastic rubber member is formed by centrifugal molding.

According to a fifth aspect of the present invention, in the fourth aspect, the filler has a higher true density than the rubber material, and forms an agglomerated layer outside in a centrifugal molding die. Elastic rubber member.

According to a sixth aspect of the present invention, in the fifth aspect, the filler is carbon black, carbon fiber,
The elastic rubber member is at least one selected from the group consisting of metal particles, metal fibers, resin particles, and resin fibers.

According to a seventh aspect of the present invention, in the fourth aspect, the filler has a lower true density than the rubber material and forms an agglomeration layer inside a centrifugal molding die. Elastic rubber member.

An eighth aspect of the present invention is the elastic rubber member according to the seventh aspect, wherein the filler is at least one selected from the group consisting of resin particles and resin fibers. .

According to a ninth aspect of the present invention, there is provided a cleaning blade formed using the elastic rubber member according to any one of the first to eighth aspects.

According to a tenth aspect of the present invention, there is provided a transport belt using the elastic rubber member according to any one of the first to eighth aspects.

Since the elastic rubber member of the present invention has a cohesive layer in which the filler is coagulated on one side in the thickness direction, the elastic rubber member can increase the Young's modulus without making the whole high hardness.

Further, by using an elastic rubber member for the cleaning blade and the conveyor belt, the cleaning blade can be produced at a low cost while being brought into contact with a high pressure without damaging the mating member. Strength can be improved.

The elastic rubber member of the present invention is preferably formed by centrifugal molding. In this case, the distribution state of the filler can be adjusted by appropriately selecting the true density of the filler to be used. . That is, in order for the filler to coagulate well on one side of the elastic rubber member, the true density of the filler may be different from that of the rubber material. An agglomerated layer can be formed on the outside of the molding die, and if a material having a true density smaller than that of the rubber material is used, an agglomerated layer can be formed on the inner side of the centrifugal mold.

Further, the elastic rubber member of the present invention also has a cohesive layer in which the filler is coagulated on one surface side in a single structure by pressing and molding two kinds of materials into a mold in a laminated state. In addition, it is possible to obtain an elastic rubber member having a low hardness rubber layer having almost no filler on the other side.

When formed by press molding in this way, the difference in the true density between the rubber material and the filler is not relevant. In press molding, it is preferable that the surface of the mold in contact with the surface of the low-hardness rubber layer used for the cleaning blade and the transport belt is mirror-finished in advance. Thus, the cleaning blade can be brought into contact with a high pressing force without damaging the partner member, and can be manufactured at low cost. Further, in the transport belt, the friction coefficient of the transport surface can be increased, and the transport force can be improved.

The rubber material used for the elastic rubber member of the present invention is preferably a thermosetting rubber material such as polyurethane or silicone rubber, especially in the case of centrifugal molding.
Thermoplastic rubber materials can also be used.

The filler in the present invention is not particularly limited as long as it forms a layer having a high Young's modulus while improving the rubber hardness by forming an aggregate layer as described above. The filler may be conductive or non-conductive, but if conductive, a desired conductivity can be imparted to the elastic rubber member.

Examples of such fillers include carbon black, carbon fibers, metal particles, metal fibers, resin particles, and resin fibers. Examples of the resin particles and resin fibers include ethylene-propylene copolymer. Coalescing,
Examples thereof include polypropylene, polyethylene, nylon 6, nylon 66, polyacetal, and polyvinylidene chloride.

When the elastic rubber member of the present invention is subjected to centrifugal molding, there is a difference in the true density from the rubber material, and a material which agglomerates outward or inward in the molding die by centrifugal molding is used.
The specific filler may be appropriately selected from those described above according to the true density of the rubber material to be used.

That is, when the true density of the filler is higher than the true density of the rubber material, the filler can be coagulated radially outward in the mold by centrifugal molding. Thereby, a low-altitude layer having relatively low hardness can be formed on the inner side in the radial direction in the molding die without substantially containing the filler.

When the true density of the filler is lower than the true density of the rubber material, the filler can be agglomerated radially in the molding die by centrifugal molding. Thereby, the filler is not substantially contained on the radially outer side in the mold, and a relatively low hardness low-altitude layer can be formed.

In any case, the formed elastic rubber member can increase the Young's modulus without making the whole high hardness, and when used for a cleaning blade and a transport belt, the cleaning blade damages the partner member. It is possible to make the contact with a high pressing force without any cost and to manufacture at low cost, and to improve the conveying force with the conveying belt.

For example, when the rubber material is polyurethane, the true density of the polyurethane is about 1.0 to 1.3, and therefore, fillers having a higher true density include carbon black, carbon fiber, and metal. In addition to particles and metal fibers, resin particles or fibers made of polyacetal or polyvinylidene chloride can be mentioned. Examples of the filler having a low true density include ethylene-propylene copolymer, polypropylene, polyethylene, nylon 6, nylon 66, and the like. And resin particles or fibers consisting of

When the rubber material is silicone rubber, since the true density of the silicone rubber is about 0.95 to 0.98, the filler having a higher true density may be carbon black, carbon fiber or metal. In addition to particles and metal fibers, resin particles or fibers composed of polycarbonate, nylon 6, nylon 66, polyacetal, polyvinylidene chloride, and the like can be given. Examples of the filler having a low true density include ethylene-propylene copolymer and polypropylene. And resin particles or fibers made of polyethylene or the like.

The amount of the filler is not particularly limited.
What is necessary is just to select suitably according to the state of aggregation, the required Young's modulus, etc.
What is necessary is just to select in the range of 0 weight part.

Here, a method for producing the elastic rubber member of the present invention by a centrifugal molding machine will be described in detail. First, a mixture of a rubber material and a filler is charged into a cylindrical drum, and the drum is set to a predetermined shape. Forming while rotating at the rotation speed. After a base layer for forming a mold surface is formed in the drum, a molding material may be charged.

When a filler having a relatively large true density is used due to centrifugal force due to rotation, the filler agglomerates radially outward to form an aggregated layer.
A rubber layer with almost no filler is formed inside. When a filler having a relatively low true density is used, the filler agglomerates radially inward to form an aggregated layer, and a rubber layer having almost no filler is formed outside. In this case, since the surface formed by the mold surface is used as the surface to be used, it is preferable that the inner surface of the mold is mirror-finished.

Here, the agglomerated layer and the rubber layer are formed integrally, and the agglomerated layer has a large rubber hardness and a large Young's modulus due to the aggregation of the filler, but the rubber layer has a small rubber hardness. When the elastic rubber member is cured, after stopping the rotation of the drum, one end is cut into a sheet shape, and after aging as necessary, particularly, if the longitudinal direction is cut along the circumferential direction, A blade member having a uniform thickness can be obtained. Further, when the cylindrical molded body is cut into a circle as it is, it can be used as a transport belt.

In the centrifugal molding method, a material containing a relatively large amount of filler is charged as a first layer, and a material in a semi-cured state with relatively little or no filler is charged. In addition, it is possible to obtain an elastic rubber member having a single structure, having an aggregated layer in which the filler is aggregated on one surface side, and having a low-hardness rubber layer on the other side with almost no filler.

The blade made of the elastic rubber member according to the present invention is used so that the surface on the low hardness rubber layer side where there is almost no filler is brought into contact with the photoreceptor or the like in a state of being adhered to a holder made of metal or resin. However, it is preferable that the surface to be adhered to the holder is a surface on which the adhered surface is hardly peeled off depending on how the blade is used.

Further, in the transport belt made of the elastic rubber member of the present invention, the aggregated layer may be used as the transport surface, but it may be turned upside down and the low hardness rubber layer may be used as the transport surface.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

FIG. 1 shows an example of the elastic rubber member of the present invention. The elastic rubber member 10A has a blade shape of a thin plate, and has a cohesive layer 11A on one surface side where the filler is aggregated, and a low-hardness rubber layer 12 on the other surface side where almost no filler is present.
A, and the cohesive layer 11A and the low hardness rubber layer 12A
Are integrally formed.

FIG. 2 shows an elastic rubber member 10B in the form of an endless belt.
1B and a low-hardness rubber layer 12B with little filler on the inner surface side, and the cohesive layer 11B and the low-hardness rubber layer 12B are integrally formed. This is, for example, a case where the filler is formed by centrifugal molding, and the filler is agglomerated on the outside of the mold, so that the filler having a relatively large true density is used.

On the other hand, FIG. 3 shows an endless belt-shaped elastic rubber member 10C, in which an agglomeration layer 1 in which the filler on the inner side is agglomerated.
1C and a low-hardness rubber layer 12C with almost no filler on the outer surface side, and the cohesive layer 11C and the low-hardness rubber layer 12C are integrally formed. In this case, for example, it is manufactured by centrifugal molding using a filler having a relatively low true density.

It is needless to say that the blade shown in FIG. 1 can be obtained by cutting the centrifugally formed sheet before forming the belt as shown in FIGS. 2 and 3.

(Examples 1 and 2) Carbon black or carbon fiber having a particle diameter or a fiber diameter shown in Table 1 below was blended with a caprolactone-based polyurethane in a composition shown below, and centrifuged (at 150 ° C., The sheet was rotated at 1400 rpm (about 350 G), and the demolded cylindrical sheet was cut to obtain a sheet having a thickness of 2.0 mm. After aging, it was cut into test pieces, and the hardness (by a Wallace hardness tester) and rebound resilience of the front and back surfaces and the whole Young's modulus were measured. In addition, the front surface was the air surface (low hardness rubber layer) side, and the back surface was the mold surface (agglomeration layer) side. Table 2 shows the results.

(Examples 3 and 4) The same procedure as described in Example 1 was carried out except that the caprolactone-based polyurethane was blended with polyethylene particles and polyethylene fibers having the particle diameters or fiber diameters shown in Table 1 below in the following proportions. And 2. In addition, the front was the air surface (agglomeration layer) side, and the back was the mold surface (low hardness rubber layer) side. Table 2 shows the results.

(Comparative Example) For comparison, a test piece was obtained in the same manner as in the example except that no carbon black or carbon fiber was added, and the same test was conducted. In the table, the air surface and the back surface are mold surfaces.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

The elastic rubber member of the present invention has an aggregated layer on one surface side where the filler is aggregated, and a low-hardness rubber layer on the other surface side where the filler is almost absent. Since the low-hardness rubber layer is integrally formed, the elastic rubber member can increase the Young's modulus without making the whole high-hardness. With the blade, the mating member can be brought into contact with a high pressing force without damaging the member, and the blade can be manufactured at low cost. With the conveyor belt, the conveying force can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing an example of an elastic rubber member of the present invention.

FIG. 2 is a view showing another example of the elastic rubber member of the present invention.

FIG. 3 is a view showing another example of the elastic rubber member of the present invention.

[Explanation of symbols]

 10A, 10B, 10C Elastic rubber member 11A, 11B, 11C Cohesive layer 12A, 12B, 12C Low hardness rubber layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 3/04 C08K 3/04 3/08 3/08 7/02 7/02 C08L 83/04 C08L 83 / 04 F16C 13/00 F16C 13/00 ABZ G03G 15/16 G03G 15/16 21/10 B29K 21:00 // B29K 21:00 B29L 29:00 B29L 29:00 31:00 31:00 G03G 21 / 00 318

Claims (10)

[Claims] 1. An elastic rubber member made of a rubber material mixed with a filler, wherein one side in a thickness direction becomes a low hardness layer having a relatively low hardness without substantially containing the filler. An elastic rubber member, wherein the other side is formed continuously with the low hardness layer, and the filler is aggregated to form an aggregate layer having relatively high hardness. 2. The elastic rubber member according to claim 1, wherein the rubber material is a thermosetting rubber. 3. The elastic rubber member according to claim 2, wherein said rubber material is formed of polyurethane or silicone rubber. 4. The elastic rubber member according to claim 1, wherein the elastic rubber member is formed by centrifugal molding. 5. The elastic rubber member according to claim 4, wherein the filler has a higher true density than the rubber material, and forms a cohesive layer outside in a centrifugal molding die. 6. The elastic material according to claim 5, wherein the filler is at least one selected from the group consisting of carbon black, carbon fiber, metal particles, metal fibers, resin particles, and resin fibers. Rubber member. 7. The elastic rubber member according to claim 4, wherein the filler has a lower true density than the rubber material, and forms a cohesive layer inside a centrifugal molding die. 8. The elastic rubber member according to claim 7, wherein the filler is at least one selected from the group consisting of resin particles and resin fibers. 9. A cleaning blade formed by using the elastic rubber member according to claim 1. 10. A transport belt using the elastic rubber member according to claim 1.