| 摘要 |
Method of preparing solvent-resistant polymer beads sizing 0.5-5 mu m and having a glass transition temperature of at least 40 DEG 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 DEG 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. |
