Process for the manufacture of heat resistant multicellular materials
Abstract
Abstract Multicellular materials having excellent heat-resistance are provided by preparing granules of 1. a prepolymer obtained from: A. a product containing an imide group, which is A. a bis-imide of the formula: ##STR1## in which D represents a radical of the formula: ##STR2## WHEREIN Y represents H, CH 3 or Cl, m is 0 or 1, and A represents a divalent organic radical containing 2 to 30 carbon atoms, or B. a mixture comprising a bis-imide of formula (I) and a mono-imide of the formula: ##STR3## in which D is as defined above and R represents a hydrogen atom or a monovalent organic radical containing 1 to 20 carbon atoms, and B. an amine product which is A. one or more polyamines containing from 2 to 5 primary or secondary amino groups, at least one of these groups being primary, or B. a mixture comprising one or more polyamines as defined under a) and one or more primary and/or secondary monoamines and/or one or more secondary polyamines, 2. a pore-forming agent and 3. a cell-forming agent, the degree of expansion (as hereinbefore defined) of which is a maximum of 90%, placing these granules in a mould, and effecting complete expansion and thermo-setting of the polymer by heating.
Inventors
- 👤 Rene Angleraud
- 👤 Pierre Ledru
Bibliographic Details
Claims Analysis
Total Claims: 10References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-07 | 1981-05-09 | 1981-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-07 | 1985-05-09 | 1985-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-07 | 1989-05-09 | 1989-11-08 | $7700.00 | Window Closed / Lapsed |