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US 5,308,883 AGranted
Catalyst for polyisocyanurate foams made with alternative blowing agents
AssigneeThe Celotex Corporation
InventorsMichael E. Londrigan, Kenneth G. Trout
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AssigneeThe Celotex Corporation
InventorsMichael E. Londrigan, Kenneth G. Trout
Estimating the term…
Rigid, closed cell polyisocyanurate foams are prepared by reacting together a polyisocyanate and a polyester polyol or a mixture of a polyester polyol and at least one other isocyanate-reactive compound in the presence of (a) a hydrogen-containing blowing agent or a mixture of a hydrogen-containing blowing agent and at least one co-blowing agent and (b) a catalyst mixture comprising (i) a carboxylate salt of an alkali metal or an alkaline earth metal or mixtures thereof, (ii) a tertiary amine, and (iii) a quaternary ammonium carboxylate salt, wherein the equivalent ratio of carboxylate metal salt: tertiary amine is a value less than about 3:1, and the quaternary ammonium carboxylate salt is present in an amount which enhances the char structure of polyisocyanurate foams made with the catalyst mixture and subjected to flammability char tests.
A process for producing a closed cell, rigid polyisocyanurate foam which comprises bringing together a foam-forming composition comprising (1) a polyisocyanate and (2) a polyester polyol or a mixture of a polyester polyol and at least one other isocyanate-reactive compound int he presence of (a) a hydrogen-containing blowing agent or a mixture of a hydrogen-containing blowing agent and at least one co-blowing agent, and (b) a catalystically effective amount of a catalyst mixture comprising (i) a salt of a carboxylic acid selected from the group consisting of an alkali metal salt and an alkaline earth metal salt and mixtures thereof, (ii) a tertiary amine, and (iii) a quaternary ammonium carboxylate salt, wherein the equivalent ratio of carboxylate metal salt:
Dependencies are inferred from the claim text.