Process for the production of a lightfast and colorfast composite plastic part
US4539166A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1983 |
| Grant date | Sep 3, 1985 |
| Priority date | — |
| Expiry date | May 5, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/83
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A first reaction mixture, prepared from (a) aromatic isocyanates with isocyanate contents of from 5 to 50%, and (b) compounds with molecular weights of from 32 to 10,000 which contain at least two isocyanate-reactive hydrogen atoms, in an equivalent ratio of component "a" to component "b" of 0.8:1 to 5:1, from 0.1 to 20% of a blowing agent and, optionally, other known additives, is introduced into a closed mold with a rigid cavity. After this mixture has become resistant to permeation, but is still compressible, a second reaction mixture, prepared from (c) aliphatic and/or cycloaliphatic polyisocyanates having isocyanate contents of from 5 to 50% and (d) compounds with molecular weights of from 32 to 10,000 which contain at least two isocyanate-reactive hydrogen atoms, in an equivalent ratio of component "c" to component "d" of from 0.8:1 to 5:1, an internal mold release agent and optionally blowing agents and other additives, is introduced into the mold, such that the second mixture surrounds the first mixture and compresses it. A third, optional, reaction mixture, the same as or different from the second mixture, may also be employed in a manner similar to the introduction of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.