Patent ID: 6204298
Filing Date: 2001-03-20
Classification: C08F,C08J

Abstract:
A process for the preparation of a polymeric foam material which comprises the steps of:A) forming a water-in-oil emulsion from:1) an oil phase comprising:a) from about 85 to about 99% by weight of a monomer component capable of forming a copolymer having a Tg value of below about 90.degree. C. or lower, the monomer component comprising:i) from about 5 to about 80% by weight of a substantially water-insoluble, monofunctional monomer capable of forming a polymer having a Tg of about 35.degree. C. or less;ii) from about 0 to about 70% by weight of a substantially water-insoluble, monofunctional comonomer capable of imparting other desired properties to the foam;iii) about 5 to about 80% by weight of a first substantially water-insoluble, polyfunctional crosslinking agent; andb) from about 1 to about 20% by weight of a n emulsifier component which is soluble in the oil phase and which is suitable for forming a stable water-in-oil emulsion; and2) a water phase comprising an aqueous solution containing: (a) from about 0.2 to about 40% by weight of a water-soluble electrolyte; and (b) an effective amount of a polymerization initiator;wherein the emulsion has a volume to weight ratio of water phase to oil phase in the range of from about 8:1 to about 140:1;B) confining the emulsion in a curing chamber so as to minimize volatilization of the components of the emulsion; andC) curing the monomer component in the oil phase of the water-in-oil emulsion using a polymerization reaction that is conducted within the curing chamber for a time period ranging from about 20 seconds to about 1 hour at a curing temperature, the curing temperature being between about 90.degree. C. and about 250.degree. C. to form the polymeric foam material.