Tris-tetrazoles as chemical blowing agents
US4127718A · kind A · utility
8Cited by
1References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1977 |
| Grant date | Nov 28, 1978 |
| Priority date | — |
| Expiry date | Oct 5, 1997 |
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 to 300.degree. C, the resulting foamed articles have a fine and homogenous cellular structure. The tris-tetrazoles I can be sythesized 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.