Terminal-modified block copolymer and compositions containing the same

A composition which comprises:

• (a) 2 to 98 parts by weight of a terminal-modified block copolymer having a terminal-treating agent bonded to the polymer terminal which is obtained by treating an active terminal of a block copolymer which comprises conjugated dienes and vinylaromatic hydrocarbon compounds and which is obtained by use of at least one member selected from the group consisting of alkali metals and organo-alkali metals as a polymerization initiator and has a vinylaromatic hydrocarbon content of 5 to 95% by weight and a least one terminal-treating agent selected from the compounds containing at least one functional group represented by the following general formula ##STR17## wherein R is hydrogen, an alkyl group of 1 to 22 carbon atoms, cycloalkyl group of 4 to 22 carbon atoms, aryl group of 6 to 22 carbons, or arylalkyl group, R' is the same as R or is an alkoxy group;
• M is silicon or tin;
• X is a halogen;
• Y is sulfur, Z is oxygen, sulfur or nitrogen, and n is an integer of 1 to 3, or compounds represented by the following general formula ##STR18## wherein R'' is an alkyl group of 1 to 22 atoms, cycloalkyl group, arylalkyl group, aryl group, or substituted aryl group;
• and n is an integer of 0 to 6, and
• (b) 98 to 2 parts by weight of a resinous substance which comprises (1) at least one highly water-absorbing crosslinking resin selected from the group consisting of the crosslinking product of the reaction product of a copolymer of maleic acid or the anhydride thereof and .alpha.-olefin with an alkali metal compound, alkaline earth metal compound, ammonia or amine;
• the crosslinking product of the reaction product of a copolymer of maleic acid or the derivative thereof and a vinyl of vinylidene compound with an alkali metal compound, alkaline earth metal compound, ammonia or amine;
• and the crosslinking product of the reaction product of a copolymer of acrylic or methacrylic acid and a vinyl or vinylidene compound with an alkali metal compound, alkaline earth metal compound, ammonia or amine;
• or (2) at least one polar thermoplastic polymer selected from the group consisting of aliphatic unsaturated carboxylic acid-containing polymer, polyamide polymer, polyester polymer, thermoplastic polyurethane polymer, vinyl alcohol polymer, polyoxymethylene polymer, polycarbonate polymer, polysulfone polymer, polyphenylene ether polymer, polyarylene sulfide polymer and polyvinyl chloride polymer.