JP3621231B2 - Gasket material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gasket material that is interposed between two members having openings and seals between the members, and more specifically, relates to a gasket material that is excellent in sealability, soundproofing properties, vibration-proofing properties, and the like.
[0002]
[Prior art]
Conventionally, in a gasket material that is installed between necessary sealing members to achieve the sealing, a synthetic rubber material excellent in compressibility and moldability, or cork grains pulverized and formed to an appropriate particle size in this synthetic rubber material is used. Synthetic rubber material containing cork grains formed by kneading has been adopted, but with the recent reduction in weight, heat and rotation of engines, high compressibility, high strength, heat resistance, etc. are required. In order to cope with this, it is disadvantageous in terms of cost and molding, but many acrylic rubbers having excellent material properties have come to be adopted, and the gasket material is now mainstream.
[0003]
[Problems to be solved by the invention]
However, as the engine becomes more compact and has higher output, higher compressibility and higher strength are desired, and gaskets made of high-performance materials are being studied.
Under such circumstances, silicone rubber, fluorosilicone rubber, or fluoro rubber is known as a cost-effective gasket material that satisfies the required performance, but silicone rubber is poor in engine oil resistance. Fluorine rubber has a negative aspect such as extreme cost increase.
[0004]
In addition, blend rubbers obtained by blending various kinds of acrylic rubber, silicone rubber, fluorine rubber, and the like, and new rubber materials that satisfy the various requirements such as heat resistance and low cost have not been developed yet.
On the other hand, in the cork material, it is used as a compressible material as a gasket material with little cross flow, but because it generates settling, a large load cannot be applied, and the strength is weak, so a thin plate product is formed I can't.
The present invention is intended to eliminate such drawbacks and to provide a gasket material that is excellent in sealing performance and rich in soundproofing and vibrationproofing.
[0005]
[Means to solve the problem]
The present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a gasket material (A) used for a gasket for an internal combustion engine or a gasket for a refrigerator, etc. The rubber sheet (3) is formed by kneading the synthetic rubber (1) and the cork granules (2) pulverized and refined to a particle size of about 5 to 30 mesh, and an adhesive is applied to both sides of the formed rubber sheet (3). A non-woven fabric (4) made of natural fiber or synthetic fiber is placed and vulcanized and molded under pressure and heating conditions to form a cork rich cork layer (5) in the middle layer, and a non-woven fabric layer on both sides (6) is disposed, the cork particles (2) are entangled in the nonwoven fabric layer (6), and the rubber layer (7) is formed by exuding the synthetic rubber (1) on both outer surfaces thereof. It is said.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 2, the gasket material (A) of the present invention was coated with a rubber sheet (3) in which cork grains (2) were kneaded with a synthetic rubber (1) and an adhesive suitable for the rubber sheet (3). The non-woven fabric (4) is superposed on both side surfaces, and this is vulcanized and bonded with a press or the like to form the gasket material (A).
At the time of this vulcanization adhesion, when the rubber sheet (3) is compressed together with the nonwoven fabric (4), the rubber sheet (3) tends to flow into the low density nonwoven fabric (4) side. ) The intricately intertwined fiber filter action prevents the migration and outflow of the fiber, leaving it as it is, and conversely, part of the synthetic rubber (1), which has excellent penetration and permeability, permeates the nonwoven fabric (4) and bleeds to the surface side. It is vulcanized and cured.
Here, a cork-rich cork layer (5) is formed in the middle part, and this is sandwiched between the nonwoven fabric layers (6) from both sides to form a rubber layer (7).
At the time of this vulcanization molding, the gasket material (A) which is firmly integrated by forming a chemical bond with the adhesive applied to the nonwoven fabric (4) at the same time as the vulcanization reaction of the synthetic rubber (1) proceeds. A stronger bond is formed by such an action.
[0007]
【Example】
Examples of the synthetic rubber (1) of the gasket material (A) of the present invention include nitrile rubber, acrylic rubber, styrene butadiene rubber, chlorobutadiene rubber, butyl rubber, silicone rubber, and fluorine rubber.
Next, as the cork grain (2), natural cork bark is put into a pulverizer and finely pulverized, then refined to a particle size of about 5 to 30 mesh, and its characteristics are lightweight and strong. It has elasticity and high compression recovery, and has excellent heat insulation, vibration absorption, and sound insulation.
Examples of the nonwoven fabric (4) include synthetic fibers such as polyester fibers, polyamide fibers, polypropylene fibers, acrylic fibers, and aramid fibers, or glass fibers, ceramic fibers, and carbon fibers, and the thickness is about 10 to 200 μm. The one having a weight of about 20 to 100 g / m ² and a tensile strength of about 1 to 10 kg / cm ² is used.
[0008]
The present invention is a gasket material (A) comprising a rubber sheet (3) obtained by kneading cork grains (2) to a synthetic rubber (1) shown in FIG. 1 and a plurality of nonwoven fabrics (4) coated with an adhesive. When this is vulcanized and integrated, depending on the type of rubber material used, for example, a temperature of 150 ° C. to 250 ° C., a clamping pressure of 0.5 to 40 kg / cm ² , a molding time of 1 to 60 If vulcanization molding is performed under pressure and heating conditions for a minute, a gasket material (A) consisting of a cork layer (5), a non-woven fabric layer (6) and a rubber layer (7) that are clearly formed in layers can be obtained. .
[0009]
In the present invention, as described above, the surface is covered with the rubber layer (7) by the exudation of the inner synthetic rubber, but due to the combination of the synthetic rubber (1) and the nonwoven fabric (4), the hardness is relatively high and does not flow laterally. Forms a high-strength layer and exhibits high sealing performance that can withstand severe sealing conditions due to satisfactory compressibility of the middle cork layer (5) and good adhesion of the rubber layer located on the surface side. It is supposed to be.
[0010]
Table 1 below shows a characteristic comparison between the gasket material of the present invention and a conventional rubber material containing cork particles.
Table 1
[0011]
【The invention's effect】
In the present invention, the cork material is mixed into the rubber material and formed into a multilayer with the nonwoven fabric (4), so that when the compression property of the rubber material is removed, the shape of the cork material is reduced to the basic shape immediately after compression. Good restoring properties to restore are brought out, and mechanical properties such as tensile strength are improved by entanglement of the nonwoven fabric (4) and the synthetic rubber (1). This high mechanical strength can increase the tightening surface pressure and dramatically improve the sealing performance. In addition, a high mechanical strength enables a thin gasket material to be formed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing another embodiment of the present invention.
[Explanation of symbols]
A Gasket material 1 Synthetic rubber 2 Cork grain 3 Rubber sheet 4 Non-woven fabric 5 Cork layer 6 Non-woven fabric layer 7 Rubber layer

Claims (1)

A rubber sheet is formed by kneading unvulcanized synthetic rubber and cork granules refined to a particle size of about 5 to 30 mesh,
A non-woven fabric with adhesive applied on both sides of the formed rubber sheet is placed and vulcanized and molded under pressure and heating conditions.
A cork rich cork layer in the middle layer, and a non-woven fabric layer on both sides,
A gasket material, wherein a rubber layer is formed by extruding synthetic rubber from the nonwoven fabric layer on both outer surfaces.