This invention relates to a process for making a vulcanized rubber article comprising
the steps of (1) kneading at a temperature within the range of about 70 C.
to about 190 C. in a bulk thermomechanical mixer (a) an amino group containing
rubbery polymer, wherein said amino group containing rubbery polymer contains from
about 0.1 weight percent to about 20 weight percent monomer units containing an
amino group, (b) from 0.1 to about 25 phr of an organophilic 2:1 layered silicate
clay selected from the group consisting of montmorillonite clays, bentonite clays,
hectorite clays, saponite clays, nontronite clays, beidellite clays, fluorohectorite
clays, stevensite clays, volkonskoite clays, sauconite clays, and laponite clays,
and (c) at least one conventional rubber compounding ingredient selected from the
group consisting of curing agents, cure accelerators, cure activators, processing
aids, reinforcing fillers, oils, cure retarders, resins, and antidegradants, to
produce a mixed compound; (2) discharging the said mixed compound from the bulk
thermomechanical mixer; (3) forming the mixed compound into an article; and (4)
vulcanizing the article.
