JPH01312272A - Gasket - Google Patents

Abstract

PURPOSE:To make it possible to produce a gasket without using asbestos by forming the same, through provision of a first layer which is formed with, on a hook face of a metal plate equipped with hook, a composite including specified percents by weight of nonasbestos fiber material, rubber as a bonding agent and a filling agent, by a direct force-bonding method, and through provision of a same layer on the first layer. CONSTITUTION:On a hook face of a metal plate equipped with a hook, there are provided a first layer which is formed, by a direct force-bonding method, from a composite including 1-50 percents by weight of nonasbestors fiber material, 5-20 percents by weight of rubber used as a bonding agent and 20-90 percents by weight of filling agent, and from a second layer which is formed on the first layer form this composition by the direct force-bonding method. It is thus possible to form a composite layer having smooth surface as well as being formed neatly over the whole even is the composite using nonasbestos fiber material as its base.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an asbestos-free gasket having a metal plate with a hook, such as a cylinder head gasket or an exhaust manifold gasket for an engine.

Traditionally, compositions containing a large amount of asbestos have been used to manufacture gaskets such as cylinder head gaskets that prevent the leakage of high-pressure gas while being exposed to high heat. Asbestos has extremely excellent properties as a gasket in terms of heat resistance, flexibility, strength, etc.
In recent years, it has been pointed out that asbestos is harmful to the human body, and there is an urgent need to develop asbestos-free gaskets.

The gasket having a metal plate with hooks has a structure in which -i is bound to the hook surface of the metal plate with hooks, and a composition containing fiber material, filler, and rubber as main components, and the manufacturing method thereof is as follows: There are mainly two methods below.

(1) A method of separately forming a sheet of the composition using the above composition, and then binding the obtained sheet to the hook surface of a hooked metal plate.

(2) A sheet layer of the above composition previously formed on a roll is directly pressed onto the hook surface of a metal plate with hooks, or the composition layer is rubbed directly onto the hook surface using a calender roll or the like to form a composition layer. (In the present invention, the method (2) is hereinafter collectively referred to as the direct compression bonding method of the composition or simply the compression bonding method).

In conventional asbestos-based compositions, asbestos itself has excellent entanglement properties due to its fine MI structure, and at the same time, it has good compatibility with fillers and rubber. Therefore, it was extremely easy to process and had good sealing properties.

On the other hand, fibers other than asbestos have poor entanglement with -S, and also have poor compatibility with fillers, rubber, etc., and their compositions have poor processability.
2) Regardless of the method used, it is difficult to manufacture high-quality gaskets with excellent sealing properties, stress relaxation properties, etc. with a high yield, and the development of technology that makes full use of asbestos-free compositions is currently an important issue. It has become.

- and 7 The present invention, as a means for solving the above-mentioned problems,
The aim is to provide an asbestos-free gasket with a new structure. Note that the fibrous material used in the present invention refers to materials excluding asbestos.

Therefore, the present invention has the following features: 1. On the hook surface of the metal plate with a hook, 1 to 503H% of non-asbestos fiber material and 5 to 20% of rubber as a binder are added.
a first layer formed by a direct compression method using a composition containing 20 to 90% by weight of a filler; and at least a second layer formed by a direct compression method using the above composition on the first layer.
2. The composition used for forming the first layer includes 5 to 50% by weight of non-asbestos fiber material and 5 to 20% by weight of rubber as a binder. The composition used for forming the second layer includes 1 to 20% by weight of non-asbestos fiber material, and rubber as a binder. 5-20% by weight, filler 40-90%
This gasket is characterized in that it uses a gasket that weighs 0 to 90%.

One feature of the present invention is that a layer of a composition based on a non-asbestos fiber material is formed on the hook surface of a hooked metal plate by the direct pressure bonding method described in (2) above, and that this process is repeated. The purpose is to form at least two layers, a first layer and a second layer. In this way, even if a composition based on a non-asbestos fiber material is used, it is possible to form a layer of the composition which is dense as a whole and has a smooth surface.

In the present invention, the composition used to form the first layer and the second layer includes 1 to 50% by weight of non-asbestos fiber material, 5 to 20% by weight of rubber as a binder, Filler 20-900-90
The compositions forming the first layer and the second layer may have the same composition or different compositions, as long as they are within the conceptual scope of the composition.

Non-asbestos fiber materials include inorganic fibers and organic fibers.

Examples of the types of inorganic fibers include ceramic fibers such as alumina-silicate fibers, alumina fibers, zirconia fibers, rock wool, and Seviolite fibers, glass fibers such as quartz glass fibers and high silicate glass fibers, carbon fibers,
These include phosphate fibers and metal fibers, and commercially available products include non-shot mineral fiber products manufactured by Nippon Cement Co., Ltd., "Rock Fiber" manufactured by Nittobo Kenzai Co., Ltd., "Kao Wool" manufactured by Isolite Kogyo Co., Ltd., and "Innofil" manufactured by Laxoburg Co., Ltd. , "Fiber Fransco" manufactured by Toshiba Ceramics, "Chopped Strand" manufactured by Unitika UMG, "Glaslon" manufactured by Asahi Fiberglass, "Carbon Black" manufactured by Nippon Carbon, "Kureha Carbon Fiber" manufactured by Kureha Chemical Industry Co., Ltd. , Nippon Seisen Shasei “Naslon”
, "Suzlon" manufactured by Lead Metals Co., Ltd., potassium titanate fiber manufactured by Jinure Kagaku Co., Ltd., and gypsum fiber manufactured by Onoda Cement Co., Ltd. One or more types of these inorganic fibers can be used.

There are no particular restrictions on the thickness or length of the inorganic fibers, but preferably the thickness is about 1 to 50 μI and the aspect ratio (ratio of length to thickness) is about 20 to 700.

Examples of organic fibers include aromatic polyamide fibers,
Phenolic resin fiber, aromatic polyester fiber, aromatic polyimide fiber, aromatic polybenzimidazole fiber,
These organic fibers include cellulose fibers, etc., and commercially available products include ``Kynol'' manufactured by Gun-ei Chemical Industry Co., Ltd., ``Kevlar 29-Valve'' manufactured by DuPont, ``Twaron Valve'' manufactured by Enka, and ``Pectron J'' manufactured by Kuraray. 1 or 2 of
More than one species can be used.

There are no particular restrictions on the thickness or aspect ratio of the organic fibers, but the thickness is 1 to 50 μm, especially 5 to 35 μm,
Those having an aspect ratio of 10 to 1000, particularly 20 to 500 are preferred.

Regardless of whether it is inorganic fiber or organic fiber, it is generally preferable that the fiber material used for the first layer is long, and conversely, the fiber material used for the second layer is preferably short. Particularly preferable fiber materials to be used are inorganic fibers with a thickness of 1 to 20 μm and an aspect ratio of 100 to 500, and organic fibers with a thickness of 3 to 20 μm and an aspect ratio of 100 to 300. be. On the other hand, especially preferable fiber materials for use in the second N are inorganic fibers with a thickness of 1 to 20 μI and an aspect ratio of 30 to 80, and organic fibers with a thickness of 3 to 20 μI and an aspect ratio of 30 to 80. 50 to 100.

Rubber is a binder for fiber materials, and includes natural rubber, styrene-butadiene copolymer rubber, acrylonitrile-
One or more types of butadiene copolymer rubber, acrylic rubber, silicone rubber, fluororubber, or other synthetic or natural rubber latex or solid rubber can be used.

Examples of the types of fillers include clay, talc, heavy calcium carbonate, light calcium carbonate, silica, mica, barium sulfate, carbon black, alumina, vermiculite, etc., and one or more of these can be used. .

The above materials are used in a ratio of 1 to 50% by weight of fiber material, 5 to 20% by weight of rubber as a binder, and 20 to 90% by weight of filler. If the amount of fiber material or filler used is too small, the stress relaxation properties of the gasket will be poor, and if the amount used is too large, it will be difficult to form a sheet. On the other hand, if the amount of rubber used is too large, the stress relaxation properties of the gasket will be poor, and if the amount used is too little, it will be difficult to form a sheet and the sealing performance will be poor.

The ratio of organic fiber to inorganic fiber used is 0 to 50 parts by weight, preferably 1 to 35 parts by weight of inorganic fiber per 1 part by weight of organic fiber. In particular, when used in the first layer, it is preferable to use 2 to 30 parts by weight of inorganic fibers per 1 part by weight of organic fibers.
When used as the 211th fiber, only organic fibers or only inorganic fibers may be used, or both fibers may be mixed in any ratio.

The amount of rubber used is preferably 7 to 15% by weight, especially 8 to 15% by weight.
12% by weight, and the amount of filler used is preferably 3% by weight.
0 to 70% by weight, especially 45 to 65% by weight.

Each of the compositions used to form the first layer and the second layer may include other compounding agents that have been conventionally added to this type of composition, such as a vulcanizing agent, a vulcanizing aid, an antioxidant, A coupling agent, a coloring agent, etc. may be added in ordinary amounts, and the mixture can be kneaded and manufactured using an ordinary mixing machine.

The metal plate with hooks used in the gasket of the present invention can be made of iron or other metals with hooks protruding from one or both sides, which have been used in the past. The first layer is first crimped by the above-described direct crimping method using a conventional method, then the second layer is crimped thereon in the same manner, and further multiple layers are formed by the same method if necessary. gaskets of the present invention can be manufactured by forming and then vulcanizing all layers.

The total thickness of all the layers formed on one side of the hooked metal plate is about 0.3 to 1.0 mm, and the thickness of the first layer and the second layer is approximately 0.3 to 1.0 mm.
In the case of layers, it is appropriate that the thickness ratio of the second layer to the first layer 10 be about 0.5 to 5.

Major Hemorrhage Below, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Examples 1 to 7, Comparative Examples 1 to 3 Compositions A to 0 shown in Table 1 were manufactured using a kneading machine, and then a hooked iron plate (thickness: 0.5 mm) having hooks on both sides was prepared using a calender roll. 2m) in the combinations shown in Table 2, first rub the composition for forming the lower layer (first layer), then the composition for forming the upper N (second layer), and finally heat at 150°C. A steel heath type gasket (thickness: 1.2 mm) was manufactured by vulcanization. In all Examples and Comparative Examples, the total thickness of both sides of the lower layer is approximately 0.
．． The total thickness of the second layer on both sides was approximately 0.2 μl. Notes 1 to 15 in Table 1 are as follows.

Note 1: Product name “Belbunan 2818 J” manufactured by Bayer
, Note 2: Product name “Nirapol LX51” manufactured by Nippon Zeon Co., Ltd.
3", Note 3: Product name "Noxtite A" manufactured by Nippon Mectron Co., Ltd.
1095J, Note 4 Nippon Cement Co., Ltd. trade name rcMF-150J,
Note 5: Product name “Ibiwool” manufactured by Ibiden, Note 6; Product name “Inofel” manufactured by Laxoburg, Note 7: Product name “Kevlar 29 Pulp” manufactured by Dupont, Note 8: Product name manufactured by Enca. “Twaron Vulp”, Note 9: Product name “Kynol” manufactured by Gunei Kagaku Co., Ltd. Note 10: Product name “Soft Neo Carrier ni” manufactured by Asada Seifun Co., Ltd. Attention: Product name “Translink Clay 37” manufactured by Engelhardt Co., Ltd. ”, Note 12: Product name “Talc S-5” manufactured by Nippon Talc Co., Ltd., Note 13 Product name “Nibsil VN-3J” manufactured by Nippon Silica Co., Ltd.
.

Note 14 - Vulcanizing agent trade name manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., Note 15
: Trade name of vulcanizing agent manufactured by Nippon Mectron.

The properties of the obtained gasket were evaluated by the method shown below, and the results are shown in Table 2.

Compression ratio and restoration ratio: Measured according to ASTM F36 method A.

Stress relaxation properties: AST? According to method B of IF38, temperature 150°C, pressure 210 kg/c+d, time 22
It was measured under the conditions of hrs.

Water sealing property: 50% for a ring-shaped test piece of 90-74mmφ
Apply a tightening force of kg/- and apply water pressure inside. Internal pressure 0
．． Starting from 5 kg/-, increase the pressure in 0.5 kg/cd steps, hold each internal pressure for 15 minutes, visually check for leakage, and measure the internal pressure at which leakage begins.

[Margin below]

The gasket of the present invention has properties such as sealing properties and stress relaxation properties that are comparable to conventional asbestos-based gaskets.

Patent applicant: Nihon Reinz Co., Ltd.

Claims (1)

[Claims] 1. 1 to 50% by weight of non-asbestos fiber material and 5 to 20% of rubber as a binder on the hook surface of the metal plate with a hook.
a first layer formed by a direct compression method using a composition containing 20 to 90% by weight of a filler; and at least a second layer formed by a direct compression method using the above composition on the first layer.
A gasket characterized by comprising a layer. 2. The composition used to form the first layer includes 5 to 50% by weight of non-asbestos fiber material and 5% by weight of rubber as a binder.
-20% by weight, 20-80% by weight of filler, 1-20% by weight of non-asbestos fibrous material as a composition used to form the second layer, and rubber as a binder. The gasket according to claim 1, which contains 5 to 20% by weight of filler and 40 to 90% by weight of filler.