JPS6245064B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention consists of a layer of transparent, translucent, or colored opaque polyurethane polymer on a release paper that is smooth or has an arbitrary uneven pattern as required, and is coated with sulfur- or peroxide-crosslinkable natural rubber or synthetic rubber. A composite film coated with one layer of a rubber graft polymer made by the manufacturing method according to Patent No. 256705 invented by the present inventor consisting of various vinyl monomers and dried, and a non-foamed unvulcanized rubber or a foamed unvulcanized rubber. This invention relates to a rubber-polyurethane composite obtained by simultaneous vulcanization and a method for producing the same. Conventionally, for the above composition, it is also possible to utilize the surface treatment method for vulcanized rubber disclosed in Japanese Patent No. 1045714, which was invented by the present inventor. That is,
The surface of the vulcanized rubber or foamed vulcanized rubber is buffed, and an appropriate amount of polyisocyanate (for example, Bonatite PC-70, Bonatite RP-700 manufactured by Kaku Kogyo Co., Ltd.) is added to a commercially available chloroprene rubber graft polymer for polyurethane bonding. For example, an adhesive containing DESMODIUR RF (manufactured by Bayer, West Germany) is applied as a primer, and then an appropriate amount of polyisocyanate is added to a commercially available polyurethane adhesive, or depending on the conditions, it is overcoated without any addition. do. On the other hand, a similar polyurethane adhesive is applied to the polyurethane polymer layer and the two are bonded together under heating, and this can be said to be a known method. The present invention, unlike the above-mentioned known method, can produce the above-mentioned rubber-polyurethane composite at the same time as the rubber vulcanization, and is significant in that it simplifies the process and significantly reduces the production cost. The adhesion between the rubber graft polymer and the intermediate layer, and the rubber graft polymer and the vulcanized rubber layer is strong, and has sufficient strength even at high vulcanization temperatures. That is, the adhesion mechanism according to the present invention is based on the polar effect of the vinyl monomer grafted to the rubber and the presence of DMF (DMF), which accounts for at least 10% of the total solvent, between the polyurethane layer on the release paper and the grafted rubber. This is thought to be due to the use of methylformamide) to dissolve the surface of the polyurethane layer and bring the distances between the respective molecules closer together, and also due to the intermolecular crosslinking effect due to the appropriate amount of isocyanate added. Furthermore, by adding an appropriate amount of radical generators such as sulfur, tetraethylthiuram disulfide (TET), or peroxide to the rubber graft polymer, it is possible to prevent the migration from unvulcanized rubber during the heat vulcanization stage of the rubber. The synergistic effect with the radicals increases the adhesion between the unvulcanized rubber and graft rubber, the graft rubber and polyurethane, and the cohesive force of the graft rubber itself, resulting in complete bonding between the polyurethane layer, graft rubber intermediate layer, and vulcanized rubber. It seems possible that this could have been achieved. Due to the chemical synergistic effect described above, the adhesion between the polyurethane layer, the rubber graft polymer, and the vulcanized rubber becomes strong, and an integral composite can be formed. Especially in the case of foam rubber,
After vulcanization, the rubber portion naturally expands when the pressure is removed, so it will be subjected to a large shearing force at the vulcanization temperature. Therefore, the adhesive force between each layer is
Sufficient chemical bonding is required to withstand these large deformations at high temperatures. The present invention has been able to exhibit sufficient adhesion to withstand these demands and satisfy the function as a composite material. The composite according to the present invention can generally be used as a floor material and a sole material for footwear, but its use is not limited thereto. Example 1 A film was coated on the surface of a release paper that was smooth or had an arbitrary uneven pattern so that the thickness of the dry film was 0.02 to 0.05 mm.
A polyurethane solution of any of Prescriptions 1 to 2 is applied and dried, and a rubber graft polymer solution of any of Prescriptions 3 to 4 is applied onto this polyurethane film so that the dry film has a thickness of 0.01.
Apply multiple coats to a thickness of ~0.03mm and allow to dry thoroughly. Next, the foaming unvulcanized rubber sheets of Formulation 5 are stacked so that no air remains in the film, and the sheets are inserted into a mold on a hot platen of a vulcanizing press, and vulcanized under pressure. Vulcanization conditions can be chosen arbitrarily, but as an example, complete vulcanization adhesion is achieved at 135°C for 30 minutes, and complete chemical adhesion is achieved by immediately taking out the contents and removing the release paper. A rubber-polyurethane composite was obtained. In this case, the foaming rate of the rubber affects the thickness of the polyurethane layer, so
It is preferable that it is not larger than necessary. Example 2 Simultaneous vulcanization was carried out in the same manner as in Example 1, using a non-foaming rubber fabric without the foaming agent instead of the unvulcanized foaming rubber fabric in Example 1. A rubber-polyurethane composite was obtained by chemical adhesion. Note that in Examples 1 and 2, the shape of the composite film on the release paper side is not particularly limited, and it goes without saying that it can be implemented in any size and shape.

【table】

[Table] Kiside
DMF 150
Desmodille RF 35

Claims (1)

[Claims] 1. Apply an outer skin layer made of colored polyurethane onto a release paper that is smooth or has an arbitrary uneven pattern,
On the outer skin layer, an appropriate amount of a polyisocyanate compound and a radical generator generated at the crosslinking temperature of the rubber, and a rubber graft polymer containing at least 10% of the total solvent, DMF, pigment, and filler are overcoated. After completing chemical bonding, two layers are formed on the release paper: a skin urethane layer and an intermediate layer of rubber graft polymer, and non-foamed unvulcanized rubber or foamed unvulcanized rubber is formed on the two layers. A method for producing a rubber-polyurethane composite, which is characterized by strongly adhering the composite by pressurizing, heating and simultaneously vulcanizing it in a mold, and then taking it out and peeling off the release paper.