Foamed polymer blends
US5114987A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1990 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Oct 15, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2421/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for preparing foamed polymer blends of thermoplastic polymers with elastomeric polymers comprises mixing the elastomeric polymers with a chemical blowing agent and compounding additives. The mixture is then combined with a thermoplastic polymer to form a blend, and thereafter mixed with a curing system and a blowing agent activator. The curable composition thus prepared can subsequently be blown in either a one or two-step process. The two-step process entails partially curing the elastomer in the composition at a lower temperature, and then blowing the composition at a higher temperature. The one-step process involves (a) heating the composition to the higher temperature initially, thereby initiating curing, and after an activating induction period of the blowing agent, producing blowing; or (b) curing and blowing the composition by extruding it through an extruder. In both processes, the elastomer present in the blend is sufficiently cured prior to blowing to prevent the escape of the blowing bubbles, but not to the extent that bubble formation is prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.