Abstract: zs An amino group-containing copolymer which is composed of (A) butadiene, isoprene or both of them, (B) acrylonitrile and (C) a (meth)acrylate represented by the general formula (I): ##STR1## wherein R is H or CH.sub.3, R.sub.1 and R.sub.2 are independently alkyl groups having 2 to 8 carbon atoms, and X is an alkylene group having 2 to 4 carbon atoms, and has a polymer composition (weight %) of (A):(B):(C) of 30 to 89.9:10 to 50:0.1 to 20. Said multi-component copolymer is used as oil-resistant rubber, and is particularly excellent in resistance to growth of crack by solvent.

Abstract: An aqueous dispersion of polymer particles each consisting essentially of (a) a syndiotactic 1,2-polybutadiene having 70% or more of unsaturated hydrocarbon groups in the side chains and having a melting point of 70.degree. C. or higher, (b) a polymer mixture of said polybutadiene (a) and other polymer in the form that (a) and (b) co-exist in the same particle, or (c) a copolymer obtained by graft-polymerizing a conjugated diene and/or other polymerizable monomer on said polybutadiene (a), each of said particles having an average diameter of 10 .mu.m or less.

Abstract: A rubber laminate of a fluororubber layer and an NBR layer firmly bonded through vulcanization is provided. The fluororubber layer is made of a fluororubber compound containing a peroxide vulcanizing agent, polyol vulcanizing agent, or polyamine vulcanizing agent. In the case where the fluororubber compound contains a peroxide vulcanizing agent, it further contains a metal oxide. The NBR layer is made of a functional NBR having a specific functional group which is determined according to the vulcanizing agent contained in the fluororubber compound. In the case where the fluororubber compound contains a peroxide vulcanizing agent or polyol vulcanizing agent, the NBR compound further contains a metal oxide. The two layers are firmly bonded through vulcanization. This rubber laminate is used for automotive fuel hoses and fuel pump diaphragms.

Abstract: A diene polymer produced by polymerizing a conjugated diene monomer in a solvent solution of an active lithium-terminated polymer in the presence of a catalyst consisting of (A) a cobalt compound and (B) carbon disulfide and/or phenylisothiocyanic acid. The diene polymer comprises a 1,2-polybutadiene portion having a high percentage of vinyl conformation. The diene polymer has substantially no mercaptan compound.

Abstract: A process for preparing conjugated diene polymers by either polymerization of one or more monomers selected from a group of conjugated diene compounds or copolymerization of a conjugated diene compound with an alkenyl aromatic compound, using an organolithium initiator in a hydrocarbon solvent, characterized in that the polymerization is carried out in the presence of(1) one or more anionic surface active agent having a group --SO.sub.3 M or --OSO.sub.3 M (where M is an alkali metal) and(2) one or more Lewis bases.