Tris-tetrazoles as chemical blowing agents
US4158724A · kind A · utility
10Cited by
2References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1978 |
| Grant date | Jun 19, 1979 |
| Priority date | — |
| Expiry date | Sep 11, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J9/108
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Tris-tetrazoles of formula I, ##STR1## wherein A is alkylene and R is hydrogen, alkyl or phenyl, are suitable blowing agents for thermoplastic resins, especially for polycarbonates and aromatic polyethers. The foaming process can be carried out at a temperature range of 230.degree. to 300.degree. C., the resulting foamed articles have a fine and homogeneous cellular structure. The tris-tetrazoles I can be synthesized from the corresponding tris-nitriles or tris-imidchlorides by reaction with an alkali azide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.