JPH111679A - Gasket material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gasket material which is excellent in sealing properties and rich in sound-and vibrationproofness by bonding a reclaimed rubber obtd. by reclaiming a rubber molding flash to a nonwoven fabric with an adhesive and subjecting the bonding product to molding and vulcanization under heating and pressure to give a laminate. SOLUTION: A rubber molding flash which is a scrap in an undervulcanized or semivulcanized state and discharged from molds during synthetic rubber molding is charged into a kneading machine and kneaded and plasticized to give a reclaimed rubber 1. Then, a nonwoven fabric 2 coated with an adhesive 3 adaptable to the reclamied rubber 1 is placed on the reclaimed rubber 1, and they are subjected to vulcanization under heating and pressure to give a gasket material A. A rubber material having physical properties improvable by secondary vulcanization is suitable as the base material for the rubber molding flash. A nonwoven fabric prepd. from synthetic fibers such as polyester, polyamide, polypropylene, acrylic, or aramid fibers and having a thickness of 10-200 μm, a basis wt. of 20-100 g/m<2> , and a tensile strength of 1-10 kg/cm<2> is pref.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasket material which is interposed between two members having an opening and seals the members, and more specifically, has a sealing property, a soundproofing property, a vibrationproofing property and the like. It relates to a gasket material which is excellent.

[0002]

2. Description of the Related Art Conventionally, in the recycling of vulcanized or semi-vulcanized rubber materials (hereinafter referred to as rubber burrs) generated in the molding of synthetic rubber, reduction of material costs and reuse of resources or environmental problems, etc., have been attempted. In view of the above, various measures have been tried, and various measures have been carried out. Among them, the following are currently used in rubber burrs reused for gasket materials. In other words, rubber burrs generated during molding of synthetic rubber are put into a pulverizer or kneader to be crushed or kneaded and regenerated, and the regenerated rubber dough is used alone or mixed with a new rubber material in an appropriate amount. The recycled gasket material was formed by vulcanization molding under heating conditions.

[0003]

However, in the case of a reclaimed gasket material obtained by vulcanizing and molding such a rubber burr alone or kneaded with a new rubber material, it is absolutely necessary to return the rubber burr to a perfect smooth state. Because it is not possible to leave small lumps, when molding this, the small lumps appear on the molding surface of the gasket material or the small lumps are in the vicinity of the surface and adversely affect the surface to have an uneven shape, It has a major drawback that deteriorates sealing performance and appearance. An object of the present invention is to eliminate such disadvantages and to provide a gasket material which is excellent in sealing performance and has excellent soundproofing and vibration-proofing properties.

[0004]

The present invention is described in detail with reference to the drawings. As shown in FIG. 1, the present invention relates to a gasket material (A) used for a gasket for an internal combustion engine or a gasket for a refrigerator. Vulcanized or semi-vulcanized rubber burrs generated after molding the rubber are put into a kneading machine, kneaded and regenerated, and the regenerated regenerated rubber (1) and the nonwoven fabric (2) are pressed through an adhesive (3). Vulcanization molding under heating conditions,
It is characterized by being integrated in layers. FIG. 2 shows a reclaimed rubber (1) and a nonwoven fabric (2), which is a gasket material (A '), in which the above-described vulcanized or semi-vulcanized rubber burr is put into a kneading machine and kneaded and regenerated. As shown in the figure, a plurality of sheets are alternately stacked, and these are vulcanized and molded under pressure and heating conditions via an adhesive (3) to be integrated into a plurality of layers.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The rubber burr of the gasket material (A or A ') of the present invention refers to surplus material discharged from a mold at the time of molding of synthetic rubber, which is in a state of insufficient vulcanization or half vulcanization. It is an imperfect vulcanizate in terms of sulfur state,
This is put into a kneading machine, kneaded and plasticized to form a recycled rubber (1). A nonwoven fabric (2) coated with an adhesive (3) compatible with the recycled rubber (1) and the recycled rubber fabric (1) are overlapped, and are pressurized and heated with a mold or the like to perform vulcanization bonding. In this vulcanization-mold bonding, the reclaimed rubber (1) plasticizes and flows into the fibers of the nonwoven fabric (2) by the heat compression of a press machine, and is entangled with the fibers. Further, the adhesive (3) applied to the nonwoven fabric (2) Causes the remaining vulcanization reaction to proceed and at the same time to form a chemical bond. By these two actions, a strong bond is formed and the gasket material (A) having high strength is obtained. At this time, due to the filter effect of the non-woven fabric (2), the small lumps of rubber burrs are not allowed to be caught in the fiber and pass through to the surface of the fiber, so that the surface of the formed gasket material (A or A ') is A smooth surface can be maintained like a new rubber material.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a base material of rubber burrs to be used as a recycled rubber (1) of the gasket material (A) of the present invention, nitrile rubber, acrylic rubber, styrene butadiene rubber, chlorobutadiene rubber, butyl rubber, silicone rubber, fluorine rubber, etc. Among them, a rubber material whose physical properties can be improved by secondary vulcanization, such as peroxide vulcanization of nitrile rubber or acrylic rubber, is particularly suitable. Examples of the nonwoven fabric (2) include synthetic fibers such as polyester fiber, polyamide fiber, polypropylene fiber, acrylic fiber, and aramid fiber.
Those having a size of 00 μm, weighing about 20 to 100 g / m ² , and having a tensile strength of about 1 to 10 kg / cm ² are used.

According to the present invention, a burr rubber material is kneaded and recycled to form a recycled rubber (1), and the recycled rubber (1) and the nonwoven fabric (2) are vulcanized and molded via an adhesive (3) to form a gasket. A material (A) is formed. Further, in order to form a plurality of layered gasket materials (A '), a plurality of incompletely vulcanized reclaimed rubbers (1) and nonwoven fabrics (2) are alternately laminated as shown in FIG. These are vulcanized and molded via an adhesive (3) to form a multilayer gasket material (A ').

The following Table 1 shows a comparison of characteristics between the gasket material of the present invention and the conventional gasket material. (1) Compared with the vulcanized product, the hardness of the recycled rubber is extremely low and the mechanical strength is also reduced. (2) In the type A, the hardness becomes (68) from the rubber side and (80) from the nonwoven fabric side, forming a hard layer and a soft layer. The mechanical strength is also slightly improved. (3) In the A 'type, the surface layer is hard (83) and the intermediate layer is soft (68), forming a sandwich structure, and providing functions such as vibration isolation.

[0009]

According to the present invention, the hardness and strength which cannot be satisfied by the conventional gasket material which plasticizes and simply re-vulcanizes the rubber burrs can be obtained by vulcanization molding in combination with the nonwoven fabric (2). A gasket material (A, A ') having hardness and strength is obtained, and the characteristics (heat resistance, oil resistance, etc.) of the base rubber composition are exhibited as they are. Further, the gasket material of the present invention also has the property of suppressing the occurrence of scratches or settling of the regenerated rubber burr, and of reducing the amount of lateral flow of the rubber layer in the compressed state when mounted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 A gasket material A 'multilayer gasket material 1 recycled rubber 2 nonwoven fabric 3 adhesive

Claims (2)

[Claims] 1. A vulcanized or semi-vulcanized rubber material generated after molding of synthetic rubber is put into a kneading machine, kneaded and regenerated, and the regenerated rubber and the nonwoven fabric are pressurized and heated via an adhesive. A gasket material characterized by being vulcanized below and integrated into a layer. 2. The vulcanized or semi-vulcanized rubber material is put into a kneading machine and kneaded and regenerated, and a plurality of formed reclaimed rubbers and nonwoven fabrics are alternately overlapped, and these are vulcanized via an adhesive. A gasket material characterized by being vulcanized under pressure heating conditions and integrated into a plurality of layers.