摘要 |
<p>PURPOSE: To bleach wood pulp using an oxidative bleaching agent under a low-toxic condition at a low cost without any scale trouble by using a specific water-soluble copolymer as an auxiliary. CONSTITUTION: Wood pulp is bleached using a peroxide together with, as a bleaching-promotive auxiliary, 0.05-1 wt.%, based on the dry pulp, of a water-soluble copolymer 1,000-80,000 in molecular weight made from (A) 50-99.9 mol% of an unsaturated monocarboxylic acid-based monomer selected from acrylic acid, methacrylic acid and salts thereof and (B) 0.1-50 mol% of an unsaturated sulfonic acid-based monomer selected from sulfonic acid group-contg. monomers and salts thereof.</p> |