Microporous elastomeric material and method of manufacture

A method of making a microporous elastomeric article having increased liquid take-up and dispensing capability comprising the steps of preparing an elastomeric matrix material by admixing an elastomeric material, from about 0.5 to 80 volume percent of sized particles of hydrated magnesium sulfate, from about 1 to about 100 parts by weight per 100 parts by weight of said elastomeric material of discrete fibers and vulcanizing ingredients, forming said matrix material into a desired shape, curing the resulting shaped matrix material while simultaneously causing liberation of waters of crystallization from said hydrated magnesium sulfate which provides a blowing effect providing the formation of interconnecting passages between said particles, leaching said particles from said matrix material and thereafter recovering the cured microporous article having said fibers dispersed therethrough, wherein said fibers increase the liquid take-up and dispensing capability of said cured articles.

A composition vulcanizable to form a microporous vulcanizate comprising an elastomeric material having substantially uniformly dispersed throughout from 0.5 to about 80 volume percent of hydrated magnesium sulfate particles and from 1 to about 100 parts of discrete fibers per 100 parts by weight of said elastomeric material, said fibers having a diameter in the range of about 0.0005 to about 0.004 inch and a length in the range of about 0.005 to about 0.250 inch, together with vulcanizing ingredients including sulfur sufficient to convert the unvulcanized composition on curing to said vulcanizate, wherein said fibers increase the liquid take-up and dispersing capability of the resulting vulcanizate.