Process for preparing foamed structures
US3993609A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1975 |
| Grant date | Nov 23, 1976 |
| Priority date | — |
| Expiry date | Feb 11, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/05
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Shaped cellular structures formed from media which are polmerizable and/or cross-linkable by free radical initiation to either a thermoplastic or thermosetting solid, process for production of such structures and the composition therefor. Process comprises preparation of composition by mixing an acid sensitive azo compound with an acidulous or acidic polymerizable medium, after which the composition is permitted to foam into a cellular structure of the desired shape. Acid sensitive azo compounds are those mono- and poly- azo compounds containing the group ##EQU1## wherein Y is monovalent or divalent acid sensitive group which in the presence of an acidulous or acidic polymerizable medium causes sufficient decomposition of the azo compound that gas is released in the medium and during said decomposition said mono- or poly- azo compounds promote polymerization and/or crosslinking to provide a matrix that is sufficiently polymerized and/or crosslinked that the generated gases cause the matrix to expand, the remaining valences in the group being satisfied by organic radicals; provided that any carbon atom that is directly linked to an azo nitrogen (except that of a carbonyl group) has …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.