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US 6,649,666 B1Granted
Propylene polymer coupling and foams
AssigneeDow Global Technologies LLC
InventorsMichael D. Read, Kevin R. Hughes, Jin Zhao, Thomas J. Styranec, Eung Kyu Kim
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Abstract
The invention includes a process for providing a coupled propylene polymer foam. The invention also includes any composition comprising a product formed by the process of the invention and any article formed from such a composition.
Claims22
A process for preparing a foam comprising the steps of:
- (i) introducing into a melt processing device:
- (a) a propylene polymer and
- (b) a coupling amount of a poly(sulfonyl azide), forming a propylene polymer admixture,
- (ii) exposing the propylene polymer admixture to a temperature sufficient to result in coupling of the propylene polymer forming a molten coupled propylene polymer composition,
- (iii) introducing a blowing agent before, during or after the coupling of the propylene polymer under a first pressure which maintains the blowing agent in the molten coupled propylene polymer composition,
- (iv) cooling the molten coupled propylene polymer composition comprising the blowing agent,
- (v) processing the molten coupled propylene polymer composition comprising the blowing agent into a zone having a second pressure which allows for the blowing agent to escape from the molten coupled propylene polymer composition and
- (vi) forming a resulting foam.
5 more elements
Dependencies are inferred from the claim text.