The disclosure relates to rubber latex formed from any of: branched block copolymers derived from alkenyl aromatic hydrocarbon1,3-diene monomer system, and branched polyisoprene homopolymers derived from isoprene. The polymers in embodiments are obtained by polymerization in the presence of an anionic initiator; at a temperature from 0? C. to 100? C.; followed by coupling with a multifunctional coupling agent of formula (R.sup.1O).sub.3SiYSi(OR.sup.2).sub.3, wherein R.sub.1 and R.sub.2 are independently C.sub.1-C.sub.6 alkyl groups; and Y is a C.sub.2-C.sub.8 alkylene group. The polymers are obtained as rubber cements having high solids content and low zero shear viscosities. The rubber cements are valuable for making latices for further applications.

The disclosure relates to rubber latex formed from any of: branched block copolymers derived from alkenyl aromatic hydrocarbon1,3-diene monomer system, and branched polyisoprene homopolymers derived from isoprene. The polymers in embodiments are obtained by polymerization in the presence of an anionic initiator; at a temperature from 0? C. to 100? C.; followed by coupling with a multifunctional coupling agent of formula (R.sup.1O).sub.3SiYSi(OR.sup.2).sub.3, wherein R.sub.1 and R.sub.2 are independently C.sub.1-C.sub.6 alkyl groups; and Y is a C.sub.2-C.sub.8 alkylene group. The polymers are obtained as rubber cements having high solids content and low zero shear viscosities. The rubber cements are valuable for making latices for further applications.

The present invention relates to amine-containing vinyldisiloxane compounds which are useful in the manufacture of elastomeric polymers that can be used in rubber articles such as tires. The present invention further relates to a process for preparing an elastomeric polymer in the presence of vinyldisiloxane compounds, an elastomeric polymer obtainable by such process, non-vulcanized and vulcanized polymer compositions comprising the elastomeric polymer and articles comprising one or more components formed from the vulcanized polymer composition, such as tires or components thereof.

The present invention relates to amine-containing vinyldisiloxane compounds which are useful in the manufacture of elastomeric polymers that can be used in rubber articles such as tires. The present invention further relates to a process for preparing an elastomeric polymer in the presence of vinyldisiloxane compounds, an elastomeric polymer obtainable by such process, non-vulcanized and vulcanized polymer compositions comprising the elastomeric polymer and articles comprising one or more components formed from the vulcanized polymer composition, such as tires or components thereof.

A bimetallic catalytic system consists of the metallic components of formulae RLi and Ca(AR.sub.y).sub.2(L).sub.x in which: R represents a substituted or unsubstituted C.sub.1-C.sub.10 aliphatic radical, a substituted or unsubstituted C.sub.6-C.sub.20 aromatic radical or a substituted or unsubstituted C.sub.1-C.sub.10 heteroaliphatic radical; A denotes N or C; y has the value 2 when A is N and the value 3 when A is C; each R represents a hydrogen atom, a substituted or unsubstituted C.sub.5-C.sub.10 aliphatic radical, a substituted or unsubstituted C.sub.6-C.sub.20 aromatic radical, a substituted or unsubstituted silyl radical, a C.sub.1-C.sub.10 aliphatic radical substituted by at least one substituted or unsubstituted silyl radical, a C.sub.6-C.sub.20 aromatic radical substituted by at least one substituted or unsubstituted silyl radical; L represents a ligand; and x is a number ranging from 0 to 4.