Process for producing coated styrenic polymer beads for heat resistant foams
US4385156A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1982 |
| Grant date | May 24, 1983 |
| Priority date | — |
| Expiry date | Apr 1, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2998
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Styrenic polymer expandable beads that are useful in forming heat-resistant foamed articles are prepared by forming an aqueous suspension of initial styrenic polymer beads and adding thereto a portion of a comonomer solution of styrenic monomer and methacrylic acid, which solution also contains a polymerization regulator, forming an emulsion of catalyst, monomer solution and polyvinyl alcohol suspending agent, adding portions of the emulsion to the suspension and then adding the remainder of the comonomer solution to the suspension, and the suspension with added monomers is heated to copolymerize the styrenic monomer and methacrylic acid about the initial beads and form a coating about the beads.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.