JPS63182499A - Production of non-asbestos type beater sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing beater sheets, specifically for use as various gasket materials for automobile engines or other general industries, particularly for cylinder heads of automobile engines. The present invention relates to a method of manufacturing a non-asbestos beater sheet suitable as a gasket material.

Be sure to read the ′′, as well as the ′′”. Since beater sheet gaskets can be mass-produced, they are generally inexpensive, and conventionally used asbestos-based beater sheet gaskets have satisfactory performance reflecting the characteristics of asbestos, so they have been used for various purposes in the past. Although it boasted a long history of use, due to the recent movement to ban asbestos from health concerns, non-asbestos beaters have been introduced.
Seat development has been highlighted as an important issue.

Stakeholders are actively investigating the manufacture of beater sheet gaskets using non-asbestos fibers such as ceramic fibers in place of asbestos, but the reality is that no product with sufficient performance has yet been obtained. .

The present invention was completed based on the results of research conducted in consideration of the above-mentioned circumstances, and its gist is that 0.5 to 10 parts by weight of cellulose fiber, 10 to 50 overlapping parts of asbestos-based heat-resistant fibers, 2 to 2 organic polymer binders
This is a method for producing a non-asbestos beater sheet, which is characterized by forming an aqueous dispersion of a component ratio composition consisting of 15 parts by weight and 30 to 90 parts by weight of an inorganic filler.

From the research of the present inventors, it has been found that the fiber material uses cellulose fibers and non-asbestos heat-resistant fibers in a specific ratio, and that a mixture of these fibers and the above-mentioned specific amounts of organic polymer bonds and inorganic fillers are used. It has been found that beater sheets with excellent heat resistance, water sealing properties, and stress relaxation properties can be obtained at low cost by paper-making using an aqueous dispersion of the composition.

Dairantan cellulose fibers include wood, hemp, ring fibers, etc.
Various plants obtained by shredding, cooking, beating, etc. can be used.

In the present invention, since the target product is manufactured by papermaking,
It is practical to use the cellulose fiber in the form of cellulose pulp, and it is preferable to use sulfite pulp, sulfuric acid pulp, soda pulp, chlorine pulp, etc., and sulfuric acid pulp, which has high mechanical strength, is particularly preferable.

Non-asbestos heat-resistant fibers include rock wool,
Heat-resistant inorganic fibers such as ceramic fibers, alumina fibers, silica fibers, surface-treated ceramic fibers (product names such as Innofil), glass fibers, natural inorganic fibers (such as Seviolite), aromatic polyamide fibers (product names such as Kevlar, Heat-resistant organic fibers such as Twaron (Twaron, etc.) and phenolic resin fibers (trade name: Kynol) are used. The heat-resistant inorganic fibers and the heat-resistant organic fibers may be used in combination. The thickness of the heat-resistant fiber is about 0.3 to 100 μm, preferably about 1 to 30 μm, and the length is about 1 to 501, preferably about 2 to 1 ore. Among the non-asbestos heat-resistant fibers mentioned above, heat-resistant inorganic fibers, particularly rock wool and ceramic fibers, are preferred.

As the organic polymer binder, latexes of various organic polymers are used, and examples of the organic polymer include rubbers such as fluororubber, acrylonitrile-butadiene rubber, acrylic rubber, and styrene-butadiene rubber.

Inorganic fillers include talc, clay, graphite,
Kaolin, magnesium silicate, calcium silicate, vermiculite, diatomaceous earth/wollastonite, zeolite, ceolide, expanded graphite, etc. are used.

In the present invention, the cellulose fibers, non-asbestos heat-resistant fibers, organic polymer binders, and inorganic fillers described above are mixed and used in the following quantitative ratios.

Cellulose fiber: 0.5 to 10 parts by weight, preferably 3 to 10 parts by weight
7 parts by weight (when pulp is used as the cellulose fiber, the amount of pulp corresponding to the dry weight of the cellulose fiber is used), non-asbestos heat-resistant fiber: 10 to 50 parts by weight, preferably 20 to 40 parts by weight Part, organic polymeric binder (as solid content in latex):
2 to 15 parts by weight, preferably 3 to IO parts by weight, inorganic filler; 30 to 90 parts by weight, preferably 50 to 70 parts by weight
Weight part.

If the amount of cellulose fiber used is less than 0.5 parts by weight, the sheet formability will be poor, while if it is more than 10 parts by weight, the heat resistance will be considerably poor. If the amount of non-asbestos heat-resistant fiber used is less than 10 parts by weight, elasticity at high temperatures will be poor, while if it is more than 50 parts by weight, water sealing properties will be poor. If the amount of the organic polymer binder used is less than 2 parts by weight, water sealing properties will be poor, while if it is more than 15 parts by weight, stress relaxation properties will be poor. In addition, the amount of inorganic filler used is 30
If it is less than 90 parts by weight, the water sealing property will be poor;
If the amount is more than parts by weight, the elasticity will deteriorate.

The objects of the present invention are cellulose fibers, non-asbestos heat-resistant fibers, organic polymer binders, inorganic fillers, and other agents added as necessary, such as anti-aging agents for organic polymer binders, Manufactured by dispersing a vulcanizing agent or other materials commonly used in beater sheets in water, making paper using a normal paper making method such as a fourdrinier paper machine or a circular wire paper machine, and then drying the paper sheet. can do.

■ Although the sheet manufactured by the method of the present invention is non-asbestos-based, it is inexpensive and has excellent heat resistance, water sealing properties, and stress relaxation properties, and is superior to conventional asbestos-based beater sheets. Shows sealing performance comparable to that of

Therefore, the sheet can be suitably used as various gasket materials for automobile engines or other general industries, particularly as gasket materials for cylinder heads of automobile engines.

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

Example 1 5 parts by weight of cellulose fiber, rock wool (average fiber diameter 5
μm, average fiber length 5tm) 15 parts by weight, ceramic fiber (average fiber diameter 2 μm, average fiber length Low) 15 parts by weight,
From 62 parts by weight of clay (product that passed 300 sesh) and 8 parts by weight of acrylic rubber (self-crosslinking acrylic acid ester copolymer emulsion).

A sheet having a thickness of 0.8 mm was obtained using a fourdrinier paper machine using a conventional paper making method. This sheet is 0.25■■
Pasted on both sides of a thick hook stand iron plate, 1.25m■
A thick sheet was prepared, and this sheet was impregnated with silicone resin and heat-treated to obtain a gasket sheet.

Example 2 5 parts by weight of cellulose fiber, rock wool (average fiber diameter 5
μM, average fiber length 5n+) 30 parts by weight, clay (300
A gasket sheet was obtained in the same manner as in Example 1, except that a composition consisting of 62 parts by weight of acrylic rubber (self-crosslinking acrylic ester copolymer emulsion) and 8 parts by weight of acrylic rubber (self-crosslinking acrylic ester copolymer emulsion) was used.

Example 3 5 parts by weight of cellulose fiber, rock wool (average fiber diameter 5
μm, average fiber length 5w) 15 parts by weight, ceramic fiber (
average fiber diameter 2 μm, average fiber length 108 m) 15 parts by weight,
42 parts by weight of clay (product passing through 300 mesh), talc (
A gasket sheet was obtained in the same manner as in Example 1, except that a composition consisting of 20 parts by weight of acrylic rubber (self-crosslinking type acrylic acid ester 7L4i11 combined emulsion) was used.

Comparative Example 1 15 parts by weight of cellulose fiber, 25 parts by weight of rock wool (average fiber diameter 5μ, average fiber length 5fl), 25 parts by weight of ceramic fiber (average fiber diameter 2μ steel, average fiber length ioms), clay (3Q O+AeshA) 25 parts by weight,
A gasket sheet was obtained in the same manner as in Example 1, except that a composition consisting of 8 parts by weight of acrylic rubber (self-crosslinking acrylic ester copolymer emulsion) was used.

The following tests were conducted on the gas get sheets obtained in Examples 1 to 3 and Comparative Example 1, and the results are shown in the table.

Stress Relaxation: A test was conducted at a test temperature of 150° C. according to the test method of JIS R3453-1985, and the ratio of residual stress to initial stress was determined.

Water sealability: A punched test piece 90-74φ was set between jigs in a test device according to ASTM F37 (Sealability test method).
Apply a tightening surface pressure of 50 kg/cJ, increase the internal water pressure in steps from 0.5 kg/ad to 0.5 kir/-, maintain it for 15 minutes for each increase in water pressure, and check the internal water pressure at which water leakage occurs. Visually check for water leakage.

Heat resistance: 20 m* x 50 mvs test piece at 200℃ x 1
After being heat-treated for 6 hours and left to stand at room temperature after being taken out, the compression rate, recovery rate, weight reduction rate, and thickness reduction rate were measured.

[Margin below]

Patent applicant: Nihon Reinz Co., Ltd. Awa Paper Co., Ltd.

Claims (1)

[Claims] 1. 0.5 to 10 parts by weight of cellulose fiber, 10 to 50 parts by weight of non-asbestos heat-resistant fiber, 2 to 5 parts by weight of organic polymer binder.
1. A method for producing a non-asbestos beater sheet, which comprises producing an aqueous dispersion of a component ratio composition comprising 15 parts by weight of an inorganic filler and 30 to 90 parts by weight of an inorganic filler. 2. The manufacturing method according to claim 1, wherein the non-asbestos heat-resistant fiber is an inorganic fiber.