THICKENING GROWTH OF RUBBER LATEX PARTICLE

摘要

PURPOSE: To economically obtain large particles rubber useful as a rubber component without occurrence of coagulated product by maintaining a rubber latex containing an emulsifier of sodium salt of a saturated fatty acid at a certain temperature for several hours. CONSTITUTION: A rubber latex containing an emulsifier comprising more than 50wt.% of a sodium salt of a 14-18C saturated fatty acid is maintained at 0-10 deg.C for more than 5 hours to thicken the rubber particles. The rubber latex is preferably a butadiene rubber containing more than 50wt.% of butadiene. The particle size of the latex is 0.05-0.2μm on the average and the solid content is 20-50wt.%. The polymerization system is kept at 8 or higher pH. The latex is statically held for 5-30 hours to effect thickening and the particles are stored, as they are stirred. The thickened particles have 0.3-0.6μm average size.