JPH0755540B2 - Method for manufacturing open cell sponge body - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an open-cell sponge body.

[Conventional technology and its problems] Conventionally, a so-called micro sponge, which is an open cell and has a cell size of about 5 to 10 μm, is used as a method for producing a sponge body having a stable porosity. The law is taking place. The elution method has the drawbacks that the number of manufacturing steps is large and that processing of the eluted eluate is expensive. Further, it takes much labor to completely remove the solute to be eluted, and if it is not completely removed, there is a problem that the solute remaining in the product stains a machine or the like during use. On the other hand, by the sintering method, open cells have good open cell properties, and it is possible to manufacture fine cells with stable porosity, but since a thermoplastic resin is used, the hardness changes greatly with temperature and the compression strain is large. There is. Therefore, the applicable range of application is extremely narrow.

The present invention has been made in view of such a point, hardness change due to temperature is small, compression resistance strain is small, moreover, open cell property is good, fine cells can be easily manufactured with stable porosity. The present invention provides a method for producing an open cell sponge body.

[Means for Solving Problems] The present invention relates to a step of mixing a vulcanized rubber powder or a thermoplastic resin powder with a thermoplastic resin and sintering the mixture to obtain a sintered body, and a crosslinking agent for the sintered body. A mixed latex of rubber, a mixed solution of a liquid rubber diluted with a solvent and a cross-linking agent, or a rubber solution prepared by dissolving a rubber compound in a solvent, and a step of impregnating the sintered body with water. Or a step of forming a sponge body by drying the solvent and heating / crosslinking the solvent to form a sponge body.

[Operation] According to the method for producing an open-cell sponge body of the present invention, a vulcanized rubber powder or a thermoplastic resin powder is mixed and sintered with a thermoplastic resin in advance to form a sintered body. Since a sponge body is formed by impregnating latex mixed with a cross-linking agent and heating / cross-linking, hardness change with temperature is small and compression resistance strain is small. Is stable and can be easily manufactured.

[Examples] Examples of the present invention will be described below.

Example 1 20 parts by weight of polyvinyl chloride (PVC) resin of 0.5 to 5 μm and 10 parts by weight of a plasticizer DBP (dibutyl phthalate) per 100 parts by weight of a vulcanized rubber powder composed of NBR (acrylonitrile butadiene rubber) compound. The parts are mixed and stirred to form a uniformly mixed powder. Then add this powder to a size of 200x20
It was filled in a female mold of 0 mm and a depth of 3 mm, and was capped with a male mold of 1.5 mm and pushed in, and pressed by a hot press for 10 minutes. This was released from the mold to obtain an open-cell sintered body having a thickness of 1.5 mm and a size of 200 × 200 mm.

Next, this sintered body is formed into a sheet, and NBR latex and colloidal sulfur as its cross-linking agent, zinc white No. 1 and vulcanization accelerator BZ are mixed and stirred to be impregnated, and then at room temperature or 80 ° C. After drying in the oven of 30
The latex was vulcanized by heating for a minute to produce a sponge body having a porosity of 45%.

A 50% compression of the obtained sponge body was carried out for 4 days and a compression set test was carried out. The reduction in wall thickness after the test was 5 to 7%, but in the case of a sintered body not impregnated with latex, A 20-25% reduction in wall thickness was observed, and Example 1
It was found that the material of No. 1 had sufficiently improved compression set characteristics. It was also found that the physical strength was improved 20 to 30 times, and the low temperature and high temperature characteristics were also sufficiently improved.

Example 2 The sintered body obtained in Example 1 was impregnated with a compound obtained by mixing NBR raw rubber and a vulcanizing agent with toluene and stirring the mixture to obtain a solution. Vulcanization was performed by heating in an oven at ℃ for 30 minutes to obtain a sponge body having open cells.

The compression set characteristics, physical strength, and low temperature / high temperature characteristics of the obtained sponge body were examined in the same manner as in Example 1. As a result, the sponge body was far better than the sintered body not impregnated with NBR raw material. I found that it was improved.

Example 3 The sintered body obtained in Example 1 was impregnated with a solution prepared by mixing and stirring liquid polyurethane rubber and a cross-linking agent and diluting with toluene, and then removing toluene from the solution, followed by 60 minutes in an oven at 120 ° C. It was heated and vulcanized to obtain a sponge body having open cells.

The obtained sponge body was examined for compression set characteristics, physical strength, low temperature and high temperature characteristics in the same manner as in Example 1, and it was found that the sponge bodies were far superior to those of the sintered body not impregnated with liquid polyurethane rubber or the like. I found that it has been improved.

Example 4 A sintered body obtained by using NR (natural rubber) in the same manner as in Example 1 was impregnated with a mixture of NR latex and its cross-linking agent and stirring, and then water was removed by drying. , 150 ℃
This was heated in the oven for 30 minutes for vulcanization to obtain an open-cell sponge body.

The obtained sponge body was examined for compression set characteristics, physical strength, low temperature and high temperature characteristics in the same manner as in Example 1, and it was found that they were far better than those of the sintered body not impregnated with natural rubber raw material. I found that it has been improved.

Example 5 A sintered body obtained by using a fluororubber compound in the same manner as in Example 1 was impregnated with a mixture of fluororubber latex and a crosslinking agent thereof and stirring, and then moisture was removed by drying. Then, it was heated in an oven at 150 ° C. for 30 minutes for vulcanization to obtain an open-cell sponge body.

The resulting sponge body was examined for compression set characteristics, physical strength, low temperature and high temperature characteristics in the same manner as in Example 1. As a result, in comparison with a sintered body not impregnated with a fluororubber compound, etc. I found that it has been improved much.

[Effects of the Invention] As described above, according to the method for producing an open-cell sponge body of the present invention, the change in curing due to temperature is small, the compression strain is small, the open-cell property is good, and the fine cells are fine. Can be easily manufactured with stable porosity.

Claims (1)

[Claims] 1. A step of mixing and sintering a vulcanized rubber powder or a thermoplastic resin powder with a thermoplastic resin to obtain a sintered body, and diluting the sintered body with a latex containing a crosslinking agent and a solvent. A step of impregnating either a mixed solution of liquid rubber and a cross-linking agent or a rubber solution obtained by making a rubber compound into a solution with a solvent, and drying water or a solvent from the impregnated material of the sintered body and heating.
And a step of forming a sponge body by crosslinking the sponge body.