Process for the production of objects made of a rigid expanded material based on polyvinyl chloride, objects obtained by said process, and uses therefor
US4469819A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1982 |
| Grant date | Sep 4, 1984 |
| Priority date | — |
| Expiry date | Sep 13, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/03
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A continuous process for making rigid PVC foam objects by extruding a preform from an initial PVC mixture, optionally cutting the preform into blanks, and expanding the preform or the blanks in water heated to a temperature above 70.degree. C. The initial mixture contains polyvinyl chloride, at least a first blowing agent capable of generating a gas, for example an isocyanate or a polyisocyanate, and at least one organic anhydride (and does not contain any added inert particles finely divided therein). The initial mixture may also contain less than one weight percent of a second blowing agent, for example azobisisobutyronitrile or azodicarbonamide. The objects produced possess heat- and sound-insulating properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.