Method of manufacturing polystyrene foam with polymer processing additives
US10059822B2 · kind B2 · utility
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23References
8Claims
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Key dates
| Filing date | Mar 7, 2014 |
| Grant date | Aug 28, 2018 |
| Priority date | — |
| Expiry date | Apr 27, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2325/06
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a method for making polystyrene foam which utilizes one or more atmospheric gases, particularly CO2, as the blowing agent in combination with a polymer processing aid (PPA), typically an ester that is relatively non-volatile at the extrusion temperature range. The blowing agent and the PPA may both be introduced into the molten thermoplastic polystyrene resin or the PPA may be incorporated in the solid source polystyrene resins. The resulting foam will be substantially free of residual blowing agent and dimensionally stable at ambient temperatures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.