Open celled low density foam and method of making such an open celled foam
US5786404A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 1997 |
| Grant date | Jul 28, 1998 |
| Priority date | — |
| Expiry date | Aug 20, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2205/05
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A lightweight open celled foam, having a density no greater than 0.5 pounds per cubic foot (pcf), preferably between 0.1 and 0.4 pcf, and a ratio of imide to amide groups greater than 1 to 1 and no greater than 19 to 1, is the reaction product made from an organic polyisocyanate having at least two functional groups per molecule and a mixture of a difunctional acid and a difunctional anhydride in the presence of a tertiary amine catalyst and a surfactant, with the reactants generating carbon dioxide during the manufacturing process. The reaction is interrupted when the amount of carbon dioxide generated from the reactants is from about 1% to about 8% by weight of the total mass of the reactants. The reaction mass is transferred after the interruption step to a second stage to complete the generation of carbon dioxide and the formation of the low density foam product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.