JPH07286669A - Composite gasket - Google Patents

Abstract

PURPOSE:To provide a highly durable composite gasket which is provided with a high sealing property by low fastening force and relieves compression force due to high surface pressure. CONSTITUTION:In a gasket sheet 1, in which a fiber material sheet punched according to a shape of a flange or a metal thin plate is used as a base material, the front and back faces of the gasket sheet 1, a bolt hole 4, and the inside of an opening part 5 are coated with liquid gasket material 2, while the circumference part of the gasket sheet 1, the opening part 5, and the outer edge part, coating layer of the bolt hole 4 are unevenly coated thicker in comparison with the coating layer of other gasket sheet faces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasket sheet having a fibrous material sheet or a metal thin plate as a base material, which is inserted into a joint surface of a flange, and a liquid gasket material which is cured to develop a rubber elastic body. It relates to a coated composite gasket.

[0002]

2. Description of the Related Art Many proposals have been made for a composite gasket in which a sheet or a metal thin plate made of a fibrous material excellent in durability and toughness is combined with an elastic rubber. For example, JP-A-50-139186, JP-A-51-148
146, JP-A-54-148952, JP-A-54-14
8953, JP-A-62-67370, JP-A-63-57.
967 and the like.

[0003] The gasket sheet is required to have a restoring force that returns to its original shape and thickness without causing a settling, even if the gasket sheet is compressed for a long time by the surface pressure caused by tightening the bolts on the flange portion. However, a gasket sheet using a fibrous material sheet or a thin metal sheet as a base material sheet is tough and has excellent durability such as high temperature and chemical resistance, but has a drawback that it is easily plastically deformed and its restoring force is poor.

Since the rubber material is an elastic body, the restoring force required as a gasket sheet is excellent. However, under high temperature conditions and high compressive forces, this restoring force may be lost, and it has the drawbacks of poor toughness and durability.

Therefore, by combining a sheet or a metal thin plate of a fibrous material having excellent durability and toughness with a rubber elastic body, a sealing effect is excellent even at a low surface pressure, and durability and toughness are provided. In addition, a gasket sheet that retains the restoring force for a long time can be obtained.

[0006]

However, compounding a gasket sheet made of a fibrous material sheet or a metal thin plate with a rubber elastic body requires a complicated manufacturing process or a special shape in terms of structure. There are drawbacks such as

For example, in the composite gaskets proposed in JP-A-51-148146 and JP-A-51-151442, press molding is required after the elastic material is arranged at a predetermined position on the thin metal gasket sheet. Also,
In the composite gasket proposed in Japanese Patent Laid-Open No. 63-57967, it is necessary to previously provide a large number of small projections on the metal thin plate so that the metal thin plate can be joined to the surface of the elastic sheet.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a gasket sheet having a fibrous material sheet punched in accordance with the shape of a flange to be inserted or a thin metal sheet as a base material. And the inside of the opening is coated in a thin film with a liquid gasket material containing chlorosulfonated polyethylene rubber as a main component.

Further, in the case where the front and back surfaces of the gasket sheet are coated with a liquid gasket material, a liquid gasket material containing chlorosulfonated polyretylene rubber as a main component is applied to the peripheral edge and the opening of the gasket sheet and the outer edge of the bolt hole. 2. The composite according to claim 1, wherein the thickness of the membrane layer is coated to be thicker than the thickness of the coating layer at other locations to make the thickness of the liquid gasket material on the front and back surfaces of the gasket sheet non-uniform. It is a gasket.

In the present invention, the coating of the front and back surfaces of the gasket sheet and the inside of the bolt holes and openings with a liquid gasket material containing chlorosulfonated polyethylene rubber as a main component has the following effects.

The coating film of chlorosulfonated polyethylene rubber coated on the front and back surfaces of the gasket sheet has thermal expansion, vibration, loosening of bolts, etc. after the base gasket sheet is subjected to compressive force due to surface pressure for a long time. In the case where the gasket sheet is released from the compressive force due to the influence of, the restoring force can be imparted to the gasket sheet, which quickly recovers the original thickness without causing the settling. Further, even if the surface accuracy of the inserted flange surface is rough, it is possible to increase the sealing effect by following the surface roughness of the flange surface due to the flexibility peculiar to rubber.

In the case of a gasket sheet made of a fibrous material, the coating film of the liquid gasket material coated on the inner side of the opening prevents gas and liquid from penetrating into the gasket sheet itself by a capillary phenomenon, and In the case of a thin gasket sheet, it works to prevent corrosion by liquid or gas. Also, the coating film inside the bolt hole is
It works to relieve excessive surface pressure from the flange surface that occurs when bolts are tightened too much.

In the present invention, the thickness of the coating layer of the liquid gasket material containing chlorosulfonated poly (ethylene rubber) as the main component at the peripheral edge portion of the gasket sheet and the outer edge portion of the bolt hole is the same as the coating layer at other locations. Coating thicker than the film thickness of, as in the case of the coating film inside the bolt hole described above,
It works to relieve excessive surface pressure and prevent the gasket sheet from settling. In addition, the thick film thickness of the coating film on the outer edge of the opening serves to further enhance the sealing effect.

In the present invention, the fibrous material base sheet is, for example, paper or non-woven fabric in which short fibers or long fibers such as pulp, rayon, polyacrylic, polyester, carbon and graphite are connected by a colloid. In addition, chlorosulfonated polyethylene (trade name: Hypalon, manufactured by Du Pont, manufactured by Showa Neoprene) has excellent chemical resistance and durability in rubber properties, and is very suitable as a material for liquid gaskets. Further, to the liquid gasket material, an inorganic filler such as talc, calcium carbonate or silica powder may be added to the rubber in order to further enhance chemical resistance and heat resistance.

According to the present invention, a gasket sheet punched into a flange shape is coated with a liquid gasket material by a usual automatic coating system such as spray coating, roll coating and curtain flow coating to obtain the composite gasket of the present invention.
In particular, spray coating or curtain flow coating is suitable for coating the opening of the gasket sheet and the inside of the bolt hole. Regarding the application of the liquid gasket to the base material sheet by the curtain flow method, JP-A-62-6737.
As described in No. 0, there is an advantage that the base material sheet can be uniformly and continuously applied to the bolt holes and openings.

The coating film of the liquid gasket material of the present invention having a non-uniform thickness is formed by applying an excessive amount of the chlorosulfonated polyethylene rubber solution on the gasket sheet surface, and then applying an excessive amount of the chlorosulfonated polyethylene rubber solution to the surface. After wrapping around from the peripheral edge of the gasket sheet and the outer edges of the bolt holes and openings to the back side and adhering it to the back side, the chlorosulfonated polyethylene rubber solution is dried and cured. Then, the gasket sheet is turned over, and an excess amount of chlorosulfonated polyethylene rubber is applied in the same manner. Further, in the present invention, this coating operation may of course be repeated.

[0017]

In the composite gasket of the present invention, since the base material sheet is coated in a thin film with the cured coating film of the liquid gasket material containing chlorosulfonated polyethylene rubber as the main component, the sheet of fibrous material or the thin metal plate is It is possible to impart the resilience and elasticity, which are the characteristics of the rubber elastic body, while having the characteristics of toughness and durability. Even if the surface accuracy of the flange surface is rough, the flexibility of the chlorosulfonated polyethylene on the surface of the gasket sheet can follow the surface roughness to enhance the sealing effect.

Since a coating film of chlorosulfonated polyethylene rubber is also applied to the inside of the opening of the gasket sheet, in the case of a gasket sheet of fibrous material, gas and liquid are prevented from permeating due to capillary action, and In the case of a thin plate, the punched section can be prevented from being corroded by gas or liquid. In the case of a gasket sheet made of fibrous material, part of the chlorosulfonated polyethylene rubber component of the liquid gasket material penetrates from the sheet surface to form a coating film, so a strong coating film is not required for baking. Can be formed. Therefore, even if the flange is disassembled and the gasket is removed, it can be reused a plurality of times.

Further, the film thickness of the liquid gasket material at the peripheral portion of the gasket sheet and the outer edge portions of the bolt holes and the openings punched out in accordance with the shape of the flange is increased so that the liquid gasket material on the gasket sheet surface is By making the film thickness non-uniform, the compressive force can be relaxed even if an excessive surface pressure is applied to the gasket sheet, and the durability of the gasket sheet with respect to plastic deformation can be enhanced. Moreover,
By increasing the thickness of the liquid gasket at the outer edge of the opening, a high sealing effect can be obtained even at low surface pressure.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a manufacturing method in which a gasket sheet punched into a predetermined shape is coated with a liquid gasket of chlorosulfonated polyethylene rubber solution (trade name: ThreeBond 1104, manufactured by ThreeBond Co., Ltd.) by a curtain flow coating method. In the curtain flow coating method, the upper surface of the sheet and the openings and the inner portions of the bolt holes can be coated simply by flying the gasket sheet in the film of the liquid gasket material that is continuously dropped. A nonwoven fabric sheet made of rayon and polyacrylic was used as the base material sheet.

In the curtain flow type coating apparatus, when the amount of the liquid gasket material dropped is increased, an excessive amount of the liquid gasket material wraps around from the upper surface to the back side of the gasket sheet. After the gasket sheet was dried, the front and rear sides were reversed and turned over, and the liquid gasket material was applied again. As a result, the gasket sheet has an average film thickness of 1
With a 00 micron chlorosulfonated polyethylene coating,
At the peripheral edge of the gasket sheet and the opening and the outer edge of the bolt hole, an average thickness of 140 μm is applied to the front and back surfaces of the coating which are not evenly coated, and a composite gasket with the inside of the opening and the bolt hole is obtained. It was FIG. 2 shows the composite gasket obtained in this example.

[0023]

According to the present invention, it is possible to obtain a composite gasket having a high sealing property with a low tightening force and relaxing a compressive force due to a high surface pressure and having an excellent durability.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a composite gasket of the present invention by applying a liquid gasket material to a gasket sheet by a curtain flow applying method.

FIG. 2 is a perspective view of a composite gasket of the present invention.

FIG. 3 is a cross-sectional view of a gasket showing a manufacturing process of the composite gasket of the present invention in the case of a curtain flow coating method.

[Explanation of symbols]

 1 Gasket sheet 2 Liquid casket 3 Curtain flow type applicator 4 Bolt hole 5 Opening 6 Excess liquid gasket wraps around the back side

Claims (2)

[Claims] 1. A gasket sheet comprising a fibrous material sheet or a metal thin plate as a base material, which is punched out according to the shape of a flange to be inserted, on the front and back surfaces of the gasket sheet, and inside the bolt holes and openings. A composite gasket characterized by being coated in a thin film with a liquid gasket material containing chlorosulfonated polyethylene rubber as a main component. 2. When the front and back surfaces of a gasket sheet are coated with a liquid gasket material, the periphery of the gasket sheet, the opening and the outer edge of the bolt hole are coated with a liquid gasket material containing chlorosulfonated polyretylene rubber as a main component. 2. The composite according to claim 1, wherein the thickness of the membrane layer is coated to be thicker than the thickness of the coating layer at other locations to make the thickness of the liquid gasket material on the front and back surfaces of the gasket sheet non-uniform. gasket.