Porous sheet material and its production
AssigneeKuraray Co., Ltd.
InventorOsamu Fukushima
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Abstract
A porous sheet material made of a polymeric material comprising mainly a polyurethane elastomer, which comprises a base layer of vertically penetrating vesicular structure and a surface layer of microporous structure integrally provided on at least one of the surfaces of the said base layer, which is suitable for the manufacture of a leather-like sheet product.
Claims8
A process for producing a porous sheet material made of a polymeric material consisting essentially of a polyurethane elastomer, which comprises applying a polymer composition in solution consisting essentially of a polyurethane elastomer and a cellular structure regulating agent, in an amount of from 3 to 25% by weight based on the weight of the polymer composition, on a support material and treating the resulting sheet material in a first stage coagulation bath at 35.degree. to 65.degree. C to coagulate the surface of said sheet material and then in a second stage coagulation bath at a temperature not less than 5.degree. C lower than the temperature of the said first stage coagulation bath to complete the coagulation to obtain the porous sheet material comprising a base layer of vertically penetrating vesicular structure and a surface layer of microporous structure integrally provided on one of the surfaces of the said base layer.
A process for producing a porous sheet material made of a polymeric material consisting essentially of a polyurethane elastomer, which comprises applying a polymer composition in solution consisting essentially of a polyurethane elastomer and a cellular structure regulating agent, in an amount of from 3 to 25% by weight based on the weight of the polymer composition, on a support material on which is previously provided a solid or solution film of a polymeric material soluble in the said polymer composition in slution and treating the resulting sheet material in a first stage coagulation bath at 35.degree. to 65.degree. C to coagulate the surface of the said sheet material and then in a second stage coagulation bath at a temperature not less than 5.degree. C lower than the temperature of the said first stage coagulation bath to complete the coagulation to obtain the porous sheet material comprising a base layer of vertically penetrating vesicular structure and a surface layer of microporous structure integrally provided on each of the surfaces of the said base layer.
Dependencies are inferred from the claim text.