Transparent supermicrocellular polymer foams from high Tg polymers and method for manufacture
OwnerSeng C. Taninventor
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Abstract
A novel class of transparent polymeric foams from high Tg polymers comprising submicron cells and a process for their production is described. The polymers are preferably high glass transition materials and the process comprises saturating a consolidated polymer shape with an inert gas at a temperature above the glass transition temperature of the polymer and under a pressure of at least 9000 psi for a period adequate to dissolve the gas in the polymer shape and then controllably cooling the polymer shape to produce the submicron cell structure.
Claims16
A process for the production of microcellular polymeric foams having cell sizes below about 1 μ comprising:
- a) saturating a consolidated polymer shape comprised of a polymer having a glass transition temperature above about 200° C. with a gas in an inert atmosphere at a temperature above said polymer glass transition temperature and at an elevated pressure of at least about 9000 psi;
- and
- b) controllably cooling said polymer to a temperature below the glass transition temperature of said polymer.
A polymeric foam of a polymer having a Tg above about 200° C. comprising individual cells less than about 0.7 μm in diameter produced from a polymer selected from the group consisting of biphenyl endcapped poly(arylene ether), 6F-polybenzoxazoles, polymer blends of polyetherketone with polyethersulfone, miscible sulfonated polyetherketone with polyetherimide, melt blends of phenylene ether phosphine oxide based hydroquinone and bisphenol with polyetherketone, and aromatic polybensoxaxoles in trimethyl polyphosphate.
A microcellular polymeric foam having a cell size below about 1 μ made by a process comprising:
- a) saturating a consolidated polymer shape comprised of a polymer having a glass transition temperature above about 200° C. with a gas in an inert atmosphere at a temperature above said polymer glass transition temperature and at an elevated pressure of at least about 9000 psi;
- b) controllably cooling said polymer to a temperature below the glass transition temperature of said polymer;
- and
- c) reducing said temperature to ambient.
Dependencies are inferred from the claim text.