Low friability polyisocyanurate foams
AssigneeTexaco Development Corporation
InventorsThomas H. Austin, George P. Speranza
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Abstract
Covers novel urethane-modified polyisocyanurate rigid foams comprising a reaction product obtained by bringing together in the presence of a blowing agent, an aromatic polyisocyanate, an isocyanurate group formation catalyst and a polyol comprising an alkylene oxide adduct of a novolak resin containing 5-25 weight percent of free phenol or substituted phenol based on the weight of said resin. Said foams are particularly characterized by their low friability, good flammability resistance and excellent thermal stability. The novel foams are useful in preparing rigid foam materials, such as, panels, slabs or sprayed foam surfaces.
Claims12
A urethane-modified polyisocyanurate rigid foam comprising a reaction product obtained by bringing together in the presence of a blowing agent, an aromatic polyisocyanurate, an isocyanurate group formation catalyst and a polyol comprising the addition product of an alkylene oxide to a mixture of a novolak resin and excess phenol or phenolic derivative wherein said phenol or phenolic derivative is present in an amount of 5-25 weight percent based on the weight of said resin.
A process for preparing a urethane-modified polyisocyanurate rigid foam comprising the steps of mixing and reacting in the presence of a blowing agent and an isocyanurate group formation catalyst, an aromatic polyisocyanate and a polyol comprising the addition product of an alkylene oxide to a mixture of a novolak resin and excess phenol or phenolic derivative wherein said phenol or phenolic derivative is present in an amount of 5-25 weight percent based on the weight of said resin.
Dependencies are inferred from the claim text.