Improvements in or relating to cellular materials

Abstract

Abstract In forming cellular material as described in Specification 578,838 by heating a resinous condensation product to a temperature below the setting point to transform it into a rubbery gel and heating the gel, generating gas or vapour and transforming it into a rigid mass, thermoplastic material, e.g. colophony, shellac, bitumen, cellulosic plastics, vinyl derivatives, or casein is added, as by milling it into the rubbery mass with the p aid of a solvent. Additional gas- or vapour-forming ingredients may be added, or inert gas, e.g. nitrogen at 5000 lbs. per sq. in. may be supplied.ALSO:In forming cellular material as described in Specification 578,838, [Group IV], by heating an aqueous syrup of a resinous condensation product to a temperature below the setting point to transform it into a rubbery gel and heating the gel, generating gas or vapour and transforming it into a rigid mass, thermoplastic material is added to the rubbery mass before the heating and expansion. The thermoplastic material may be colophony, shellac, bitumen, cellulosic plastics such as cellulose nitrate or acetate or ethyl cellulose, vinyl derivatives such as polyvinyl chloride, polyvinylacetal, polystyrene. polymethylmethacrylate, or polyisobutylene or casein, and may be milled into the rubbery mass with the aid of a solvent. Additional gas- or vapour-forming ingredients may be added or the mass may, before the final heating, be submitted to an inert gas under pressure, e.g., nitrogen at 5000 lbs. per sq. in.

Inventors

No inventors recorded.

Bibliographic Details