A fine-particle, free-flowing rubber powder containing silicatic fillers,
one or more organosilanes having trialkoxysilyl groups, and a rubber
prepared by solution polymerization is prepared by a process that starts
from a two-phase system: 1) filler in water, and 2) rubber in organic
solvent. A rubber/silicatic filler/silane composite is formed during
transfer, under gentle conditions, of the various reactants into a single
phase. The process features a high degree of freedom in selecting forms of
filler and in selecting the organosilane and gives a finished rubber
powder in which a silicatic filler and an organosilane have undergone
complete chemical reaction.
