JPS6396359A - Gasket material - Google Patents

Abstract

PURPOSE:To improve the sealing property, by coating a metal plate with a compound of a base material fiber which consists of a compressible inorganic fiber other than asbestos, and a rubber material. CONSTITUTION:A layer 1 of a compound is spread on both sides of a SPCC steel plate 3 coated with a heatproof adhesive beforehand, and the surface of the compound layer 1 is processed with graphite, to form a gasket material. The compound layer 1 consists of a base material fiber of a compressible inorganic or organic fiber other than asbestos and a rubber material. Therefore, the heatproof property is improved compared with a conventional rubber-coated gasket, and the sealing property can be maintained for long.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a gasket material used as a base material for various gaskets, and particularly to a type of gasket material in which a layer of compressible material is coated on the surface of a metal plate. .

[Problems to be solved by conventional technology and invention]

SPCC has traditionally been used as one of this type of gasket materials.
(hereinafter referred to as rubber coating gasket material)
This type of gasket material has been widely used because it has various advantages such as:

(b) Can be embossed (embossing refers to forming a continuous convex part with a semicircular cross section on the gasket material, and such a convex part can be formed around the seal part by embossing as necessary) By doing so, the sealing performance of the gasket can be further improved).

(b) Since the base material is a metal plate, it has great strength, and even in areas where the gasket width is narrow, the gasket will not break and will not be blown away.

(c) Since it does not have a fibrous structure like asbestos joint sheets, there is no substance leakage or oozing from the gasket itself.

(d) Excellent torque retention, with extremely little torque down.

(e) Good thickness accuracy.

(f) Dimensional accuracy is good because centering can be performed using a mold.

(G) Since it is mainly made of metal plates, workability is good,
Easy to incorporate into seal parts of various machines.

(h) Since it is mainly made of metal plates, it has excellent aging resistance against heat.

(S) Unlike asbestos joint sheets, there is no inconvenience caused by fluffing of asbestos fibers.

However, the gasket material coated with a layer of synthetic rubber alone as described above has the following drawbacks because the coating layer is made of synthetic rubber.

(a) The heat resistance temperature is usually as low as about 150°C.

(b) If the load is excessive during tightening, the surface rubber layer will flow sideways and the rubber layer will easily peel off. In particular, if there is a part that receives excessive stress during embossing, the rubber layer tends to flow sideways in that part and peel off.

When this kind of peeling of the rubber layer occurs, kudzu naturally tends to leak as a gasket.

(C) If excessive stress is applied, the torque of the bolt tends to decrease due to the lateral flow of the rubber.

(d) As the layer of synthetic rubber becomes thicker, its lateral flow increases and embossing becomes impossible due to the elasticity of the rubber (i.e., even if the convex part of the mold presses against the gasket material, (It is absorbed by the deformation of the rubber and cannot deform the metal plate portion sufficiently.) Therefore, the thickness of the rubber layer is limited to about 100 μm on one side, and it is impossible to make it thicker than that.

In order to eliminate the drawbacks of the above-mentioned rubber coating gasket materials, we have developed a gasket material in which the surface of the metal plate is coated with a rubber asbestos compound containing asbestos at a ratio of 60 to 80% by weight, instead of using synthetic rubber alone. below,
Rubber, asbestos, compounds, coatings, and gasket materials have also been developed and used in recent years.

However, recently, it has been pointed out that asbestos has an adverse effect on the human body, and banning the use of asbestos has become an imminent issue.

For this reason, it has become necessary to compose compounds using fiber base materials instead of asbestos, but until now it has been impossible to create compounds due to reasons such as the asbestos substitute fibers not being uniformly dispersed in the rubber material. Problems such as coating on a metal plate, insufficient heat resistance, and deterioration of sealing properties have occurred, and satisfactory results have not been obtained.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned conventional problems, and can not only eliminate the drawbacks of conventional rubber coating gasket materials without using asbestos, but also be able to solve the problems of rubber, asbestos, compound coating, The purpose of the present invention is to provide a gasket material that can obtain performance equivalent to that of gasket materials.

(Means for Solving the Problems) The gasket material according to the present invention has a base made of compressible inorganic fibers other than asbestos, compressible organic fibers, or both, on the surface of a metal plate coated with a heat-resistant adhesive in advance. It is coated with a layer of compound containing material fibers, rubber material, rubber chemicals, and inorganic fillers.

[Effect]

In the present invention, the metal plate is coated not with rubber alone, but with a compound of base fibers made of compressible inorganic fibers other than asbestos, compressible organic fibers, or both, and rubber material, so that the metal plate is not coated with rubber alone.・Higher heat resistance than gasket materials.

Further, the coating layer becomes less prone to cross flow and peeling, and torque retention characteristics are also improved.

Furthermore, the thickness of the coating layer can be increased to about 200 μm on one side.

In this way, it not only eliminates the drawbacks of conventional rubber coatings and gasket materials, but also has various physical properties and sealing properties that are equivalent to or even superior to rubber, asbestos, compound coatings, and gasket materials. performance.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

A compound having the following composition was prepared.

(i>Glass fiber...30% by weight (
ii) Fibrillated aromatic polyamide fiber (trade name: Kevlar Pulp, manufactured by DuPont)...10% by weight (iii
) Nitrile rubber (NBR)...16% by weight (
iV) Rubber chemicals...4% by weight (V
) Inorganic filler...40% by weight As shown in Figure 1, layer 1 of the compound having the above composition.
was coated on both sides of a 5 pcc steel plate 3 that had been previously coated with a heat-resistant adhesive 2, and after rough graphite treatment was applied to the surface of the compound layer 1 (4 indicates the graphite layer), the mixture was heated at 140°C to 160°C. A gasket material was formed by performing heat treatment at a temperature of 30 to 40 minutes.

Note that the heat treatment is performed using the rubber, rubber chemicals, and the synthetic resin mixed in the graphite layer 4 (this synthetic resin is mixed in the graphite layer 4 because it is impossible to coat the compound layer 1 with graphite alone). This is done in order to cause crosslinking by reacting the following compounds:

Further, in this embodiment, the plate thickness t1 of the steel plate 3 is 0.3
M, the total thickness t2 of the graphite layer 4 and the compound layer 1 is 100μ for each side of the steel plate 3, and 20μ for both sides.
0μ, and the thickness of the graphite layer 4 is 2 to 3μ.

In this gasket, the metal plate is coated with a compound layer 1 of glass fibers, aromatic polyamide fibers, and rubber material instead of rubber alone, so the heat resistance is improved compared to conventional rubber-coated gasket materials.

Further, the compound layer 1 is less likely to cause cross-flow or peeling, and the torque retention characteristics are also improved.

Furthermore, the thickness of the compound layer 1 can be increased to about 200 μm on one side.

Further, Table 1 shows the gasket of the above embodiment and the spcc
Conventional rubber, asbestos, compound,
Various physical properties were tested and compared with a coating gasket material (the thickness of the SPCI plate and the thickness of the compound layer were the same as in the previous example). As is clear from this table, the gasket material of the present invention has various physical properties equivalent to those of the gasket material using asbestos. Particularly heat resistant at 200℃-16
The compressibility after IR heating shows very little change compared to the compressibility at room temperature, indicating that this gasket has excellent heat resistance. In addition, the stress relaxation rate, which is a substitute characteristic for torque reduction, is extremely low, and in terms of heat resistance and torque retention, the properties are rather improved compared to conventional gasket materials using asbestos.

Furthermore, although not shown in Table 1 above, according to a separate leakage property test, the gasket material of the above example was found to be superior to conventional rubber, asbestos, compound coating, and sealing properties. Equivalent to gasket material. In this way, the gasket material of the present invention not only eliminates the drawbacks of the conventionally widely used rubber coating gasket materials without using asbestos, but also can be compared with rubber, asbestos, compound coatings, and gasket materials. However, they are equivalent in various physical properties and sealing properties, and even have superior performance in terms of shelf life.

In the above embodiments, a steel plate is used as the metal plate, but other metal plates such as an aluminum plate, a stainless steel plate, etc. can also be used in the present invention.

In addition, in the above embodiment, inorganic I other than asbestos! Although glass fiber is used as the i-fiber, other inorganic fibers such as ceramic fiber, rock wool, mineral wool, fused silica fiber, chemically treated high silica fiber, fused alumina silicate fiber, alumina continuous fiber, Stabilized zirconia tIA fibers, boron nitride fibers, alkali titanate fibers, whiskers, boron fibers, carbon fibers, metal II, etc. can also be used.

Further, in the above embodiments, aromatic polyamide fibers are used as the organic fibers, but in the present invention, other organic fibers such as polyamide fibers, polyolefin fibers, polyester fibers, polyacrylonitrile fibers,
polyvinyl alcohol fiber, polyvinyl chloride fiber,
Polyurea fibers, polyurethane fibers, polyfluorocarbon fibers, phenol fibers, cellulose fibers, etc. can also be used.

Further, in the above embodiments, NBR is used as the rubber material, but in the present invention, other rubber materials such as styrene butadiene rubber (SBR), isoprene rubber (IRE
, chloroprene rubber (CR), butadiene rubber (BR)
, butyl rubber (IIR), ethylene-propylene rubber (EPM), fluororubber (FPM), silicone rubber (
S i >, chlorosulfonated polyethylene (C3
M), ethylene vinegar rubber (EVA), chlorinated polyethylene (CPE), butyl chloride rubber (CIR), epichlorohydrin rubber (ECO), nitrile isoprene rubber (NR), natural rubber (NR), etc. can also be used. Furthermore, oil-extended rubber obtained by adding naphthenic process oil to these rubber materials, such as 5i3R, can also be used as the rubber material.

In addition, rubber chemicals include sulfur, zinc oxide, magnesium oxide, peroxide, vulcanizing agents such as dinitrolibenzene, thiazole compounds, polyamine compounds, sulfenamide compounds, dithiocarbamate compounds, and aldehyde amines. Vulcanization accelerators such as vulcanization compounds, guanidine compounds, thiourea compounds, and xanthate compounds can be used.

Further, as the filler, clay, talc, barium sulfate, sodium bicarbonate, graphite, lead sulfate, tripolite, wollastonite, etc. can be used.

〔Effect of the invention〕

As described above, according to the present invention, not only can the drawbacks of conventional rubber coating gasket materials be overcome without using asbestos, but also compared to rubber, asbestos compound coating gasket materials, Equivalent or even superior performance can be obtained in various physical and sealing properties.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the gasket material according to the present invention. 1... Compound layer, 2... Adhesive material, 3.-3P
CC steel plate. Patent applicant: Agent of Nisan Gasket Co., Ltd.
Patent Attorney Daigaric Izumi Figure 1

Claims (1)

[Claims] A base fiber made of compressible inorganic fibers other than asbestos, compressible organic fibers, or both, a rubber material, a rubber chemical, and an inorganic filler are applied to the surface of a metal plate coated with a heat-resistant adhesive in advance. A gasket material coated with a layer of compound.