Bis-tetrazoles as chemical blowing agents for foaming thermoplastic resins
US4142029A · kind A · utility
31Cited by
3References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 12, 1977 |
| Grant date | Feb 27, 1979 |
| Priority date | — |
| Expiry date | Jul 12, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J9/108
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Bis-tetrazoles wherein the two tetrazole rings are bridged by a direct bond or a divalent organic residue in 5,5'-position or in 1,1'-position have been found to be suitable as blowing agents for thermoplastic resins. They decompose at temperatures of about 230 to 300.degree. C. and therefore can be used for the expansion of resins which are processed at such temperatures, for instance polypropylene, polycarbonates, polyphenyleneoxides or polyamides. Preferred are bis-tetrazoles bridges by aliphatic or araliphatic residues. The expansion can be carried out in an extruder or an injection moulding device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.