Element containing solvent-resistant polymer beads
US5252445A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1991 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Jul 16, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31797
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Method of preparing solvent-resistant polymer beads sizing 0.5-5 pm and having a glass transition temperature of at least 40.degree. C. by dissolving in a solvent mixture of water and water-miscible polar organic solvent an Alpha, Beta-ethylenically unsaturated monomer (1) capable of forming a polymer that is soluble in the monomer(s) present in said solvent mixture but which is insoluble in said solvent mixture, a monomer (2) carrying COOH group(s), a monomer (3) carrying halogen atom(s), a free radical-forming polymerization initiator, and a graft-polymerizable polymer containing hydrophilic groups, heating the solution obtained to a temperature from 50.degree. C. to the reflux temperature thereof with stirring to form said beads, converting said COOH group(s) by reaction with a hydroxide into a carboxylic acid salt group, and causing said carboxylic acid salt group to react with said halogen atom to form ester cross-linkages. The beads can be used as spacing agents in a sheet or web material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.