Methods for preparing a formed cellular plastic material pattern employed in metal casting
US4790367A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1988 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Jan 28, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22C7/023
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units are disclosed. These materials when expanded have a volume expansion of at least 60 and maintain that volume expansion for a period of at least 30 minutes under expansion conditions after reaching the volume expansion of 60. Expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units and an inhibitor for the monomer(s) and a crosslinker incorporated into the plastic material upon monomer polymerization are also disclosed. Also disclosed are expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units with blowing agents of 2,2-dimethylbutane, 2,3-dimethylbutane or mixtures of one or both with 1-chloro-1,1-difluoroethane or mixtures of at least 30 percent of one or both with other volatile blowing agents. These specific types of formed patterns and core assemblies, wholly or partially formed from the destructible expanded closed-cell cellular plastic materials of the present invention have a decreased tendency to form nonvolatile residue during the casting of metals such as iron. Superior castings are th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.