Thermal stability and the block copolymer constituent null which is superior in resistance discoloration Characteristic of the long-term storage

摘要

PURPOSE: To obtain the subject composition having excellent thermal stability and color change resistance during long-term storage by blending a block copolymer comprising a monoalkenyl aromatic compound and a conjugated diene with specific two kinds of phenolic stabilizers. ;CONSTITUTION: (A) 100 pts.wt. of a block copolymer comprising a polymer segment consisting essentially of a monoalkenyl aromatic compound and a polymer segment consisting essentially of a conjugated diene, having 5-95wt.% of a monoalkenyl aromatic compound content or a mixture of the copolymer, a thermoplastic resin and/or a rubber-like polymer are blended with (B) 0.005-0.2 pt.wt. of a phenolic stabilizer of formula I [R₁ and R₃ are CH₂-S-R₅ (R₅ is 1-18C alkyl); R₂ is H or methyl; R₄ is 1-8C alkyl or 5-12C cycloalkyl] and (C) 0.05-2 pts.wt. of a stabilizer selected from phenolic compounds of formula II and formula III (R₆ is R₅; R₇ is tert-amyl, cyclohexyl, etc.; R₈ to R₁₁ are H or 1-18C alkyl) to give the objective composition.;COPYRIGHT: (C)1994,JPO