PAPER PRODUCTION WITH MODIFIED SILICA GELS AS MICROPARTICLES

摘要

Use is claimed of sulfonic acid- or mercapto-group-containing silica sols as microparticles in papermaking, especially in paper retention. Independent claims are also included for (1) sulfonic acid- or mercapto-group-containing silica sols having a TEM average particle size of 2-45 (especially 2-20) nm or having a sulfur content (based on SiO 2) of 0.1-30 (especially 1-50) mol%; and (2) preparation of these silica sols.