JPH0514829B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an asbestos-free gasket having a metal plate with a hook, such as a cylinder head gasket for an engine or an exhaust manifold gasket. BACKGROUND ART Compositions containing large amounts of asbestos have traditionally been used to manufacture gaskets, such as cylinder head gaskets, which prevent leakage of high-pressure gas while being subjected to high heat. Asbestos is heat resistant,
Although asbestos has extremely excellent characteristics as a gasket in terms of flexibility and strength, in recent years it has been pointed out that asbestos is harmful to the human body, and the development of asbestos-free gaskets is urgently needed. It's summery. A gasket having a metal plate with a hook generally has a structure in which a composition mainly composed of fiber material, filler, and rubber is bonded to the hook surface of the metal plate with a hook, and its manufacturing method is mainly as follows. There are two methods. (1) A method of separately forming a sheet of the composition using the above-mentioned composition, and then binding the obtained sheet to the hook surface of a metal plate with a hook. (2) A sheet layer of the above-mentioned composition previously formed on a roll is directly pressed onto the hook surface of a metal plate with a hook, or the composition lump 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). Problems that need to be solved Conventionally used asbestos-based compositions have excellent entanglement properties due to asbestos's fine structure, and at the same time have good compatibility with fillers and rubber. It is extremely easy to process,
Sealing properties were also good. On the other hand, fibers other than asbestos generally have poor entangling properties themselves, and also have poor compatibility with fillers, rubber, etc., and their compositions have poor processability, resulting in the above-mentioned (1) and (2) Regardless of the method used, it has become difficult to manufacture high-quality gaskets with excellent sealing properties and stress relaxation properties at a high yield, and the development of technology that makes full use of asbestos-free compositions is currently an important issue. There is. Means for Solving the Problems The present invention aims to provide an asbestos-free gasket with a novel structure as a means for solving the above-mentioned problems. Note that the fibrous material used in the present invention refers to materials excluding asbestos. Therefore, the present invention has the following features: 1. The hook surface of the metal plate with a hook contains 1 to 50% by weight of non-asbestos fiber material, 5 to 20% by weight of rubber as a binder, and 20 to 90% by weight of filler. 2. A gasket comprising: a first layer formed by a direct pressure bonding method using a composition; and at least a second layer formed from the above composition by a direct pressure bonding method on the first layer; and 2. As a composition used to form one layer,
5-50% by weight of non-asbestos fiber material, 5-20% by weight of rubber as a binder, 20-80% of filler.
The composition used for forming the second layer includes 1 to 20% by weight of non-asbestos fiber material, 5 to 20% by weight of rubber as a binder, and a filler. This gasket is characterized in that it contains 40 to 90% by weight of Effect of the Invention The feature of the present invention is to form a layer of a composition based on a non-asbestos fiber material on the hook surface of a metal plate with a hook by the direct pressure bonding method described in (2) above, and to repeat this process to at least The purpose is to form 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. DETAILED DESCRIPTION OF THE INVENTION 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 fibrous material, 5 to 20% by weight of rubber as a binder, and filler. 20
~90% by weight, and as long as it is within the conceptual range of the composition, the compositions forming the first layer and the second layer may have the same composition, or may have different compositions. It's okay. Non-asbestos fiber materials include inorganic fibers and organic fibers. Examples of inorganic fibers include ceramic fibers such as alumina-silicate fibers, alumina fibers, zirconia fibers, rock wool and sepiolite fibers, glass fibers such as quartz glass fibers and high silicate glass fibers, carbon fibers, phosphate fibers,
Commercially available products include non-shot mineral fiber manufactured by Nippon Cement Co., Ltd., ``Lock Fiber'' manufactured by Nittobo Kenzai Co., Ltd., ``Kao Wool'' manufactured by Isolite Kogyo Co., Ltd., ``Innofil'' manufactured by Laxoburg Co., Ltd., and ``Innofil'' manufactured by Toshiba Ceramics Co., Ltd. "Fiber Flux", "Chopped Strand" manufactured by Unitika Um Glass, "Glaslon" manufactured by Asahi Fiber Glass, "Carboron Z" manufactured by Nippon Carbon Co., Ltd.
"Yarn", "Kureha Carbon Fiber" manufactured by Kureha Chemical Industry Co., Ltd., "Naslon" manufactured by Nippon Seisen Co., Ltd., "Suzlon" manufactured by Suzuki Metal Co., Ltd., potassium titanate fiber manufactured by Otsuka Chemical 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 μm and the aspect ratio (ratio of length to thickness) is about 20 to 700. Examples of organic fibers include aromatic polyamide fibers, phenolic resin fibers, aromatic polyester fibers, aromatic polyimide fibers, aromatic polybenzimidazole fibers, and cellulose fibers. Kynor”,
"Kepler 29-Pulp" manufactured by DuPont, "Twaron Pulp" manufactured by Enka, "Vectron" manufactured by Kuraray
etc. One or more types of these organic fibers can be used. There are no particular restrictions on the thickness or aspect ratio of organic fibers, but the thickness should be 1 to 50 μm, especially 5 to 35 μm.
and the aspect ratio is 10-1000, especially 20-500
Preferably. Regardless of whether it is an inorganic fiber or an 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 for use in the first layer 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 100. There are 300 of them. On the other hand, especially preferable fiber materials for the second layer are inorganic fibers with a thickness of 1 to 1.
20 μm and an aspect ratio of 30 to 80; organic fibers have a thickness of 3 to 20 μm and an aspect ratio of 50.
~100 things. Rubber is a binder for fiber materials, and includes natural rubber, styrene-butadiene-copolymer rubber, acrylonitrile-butadiene-copolymer rubber, acrylic rubber, silicone rubber, fluorine rubber, and other synthetic or natural rubbers. One or more types of latex and solid rubber can be used. Examples of filler types include clay, talc,
Heavy calcium carbonate, light calcium carbonate,
These include silica, mica, barium sulfate, carbon black, alumina, vermiculite, etc., and one or more of these can be used. The above materials are 1 to 50% by weight of fiber material, 5 to 20% of rubber as a binder, and 20 to 90% of filler.
used in the ratio of 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 too much rubber is used, the stress relaxation properties of the gasket will be poor, and if too little is used, it will be difficult to form a sheet and the sealing performance will be poor. Regarding the usage ratio of organic fibers and inorganic fibers,
The amount of inorganic fiber is 0 to 50 parts by weight, preferably 1 to 35 parts by weight, per 1 part by weight of organic fiber. In particular, when used in the first layer, 2 parts by weight of inorganic fibers per 1 part by weight of organic fibers.
~30 parts by weight is preferred, but when used in the second layer, only organic fibers or only inorganic fibers may be used.
Further, both fibers may be mixed and used in any ratio. The amount of rubber used is preferably 7 to 15% by weight, especially 8 to 12% by weight, and the amount of filler used is preferably 30 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 contain other additives that have been conventionally added to this type of composition, such as a vulcanizing agent, a vulcanizing aid,
Antioxidants, coupling agents, coloring agents, etc. may be added in normal amounts, and the product can be kneaded using a normal kneading machine. The hook-equipped metal plate 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 are conventionally used. First, the first layer is crimped by the above-mentioned direct crimping method according to a conventional method using
Next, a second layer is similarly pressure-bonded thereon,
Furthermore, if necessary, more layers can be formed in a similar manner and then all the layers can be vulcanized to produce the gasket of the present invention. The total thickness of all the layers formed on one side of the metal plate with a hook is about 0.3 to 1.0 mm, and in the case of two layers, the first layer and the second layer, the thickness ratio of both layers is It is appropriate that the second layer has a thickness of about 0.5 to 5 with respect to the layer 10. Examples Hereinafter, 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 O shown in Table 1 were manufactured using a kneader, and then a iron plate with hooks (thickness: 0.2 mm) having hooks on both sides was prepared using a calender roll. ) in the combinations shown in Table 2, first apply the composition for forming the lower layer (first layer), then apply the composition for forming the upper layer (second layer).
Layer) forming composition is rubbed one after another, and finally at 150℃
A steel vest-type gasket (thickness: 1.2 mm) was manufactured by vulcanizing the mixture. In both Examples and Comparative Examples, the total thickness of both sides of the lower layer is approximately 0.8
mm, and the total thickness of the second layer on both sides was about 0.2 mm. Notes 1 to 15 in Table 1 are as follows. Note 1: Product name “Perbunan 2818” manufactured by Bayer, Note 2: Product name “Nitupol” manufactured by Nippon Zeon
"LX513", Note 3: Product name "Noxtite A1095" manufactured by Nippon Mektron Co., Ltd., Note 4: Product name "CMF-150" manufactured by Nippon Cement Co., Ltd., Note 5: Product name "Ibi Wool" manufactured by IBIDEN Corporation, Note 6: Product name “Innofil” manufactured by Luxoburg, Note 7: Product name “Kevlar 29 Pulp” manufactured by Dupont, Note 8: Product name “Twaron Pulp” manufactured by Enka, Note 9: Product name manufactured by Gunei Chemical Co., Ltd. "Kynol", Note 10: Product name "Soft Neocaria K" manufactured by Asada Seifun Co., Ltd., Note 11: Product name "Translink Clay 37" manufactured by Engelhardt Co., Ltd., Note 12: Product name "Talc" manufactured by Nippon Talc Co., Ltd. "SW5", Note 13: Product name "Nipsil VN-" manufactured by Nippon Silica Co., Ltd.
3'', Note 14: Trade name of vulcanizing agent manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., Note 15: Trade name of vulcanizing agent manufactured by Nippon Mectron Co., Ltd. The characteristics of the obtained gasket were evaluated by the method shown below, and the results are shown in Table 2. Compression rate and recovery rate: Measured according to ASTM F36 method A. Stress relaxation properties: According to ASTM F38 method B,
Measurement was performed under the conditions of temperature 150°C, pressure 210 Kg/cm ² , and time 22 hrs. Water sealability: 50 for a 90-74mm ring-shaped specimen
Apply a tightening force of Kg/cm ² and apply water pressure inside. Start with an internal pressure of 0.5Kg/ ^cm2 , increase the pressure in 0.5Kg/ ^cm2 steps, hold each internal pressure for 15 minutes, visually check for leaks, and measure the internal pressure at which leakage begins.

【table】

【table】

[Table] Effects of the Invention The gasket of the present invention has high performance comparable to conventional asbestos-based gaskets in terms of properties such as sealing properties and stress relaxation properties.

Claims (1)

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