| 摘要 |
The present invention is at least a two-component thermoplastic elastomeric composition comprising at least one block copolymer wherein the composition has essentially the same comparative elasticity, high temperature serviceability and hardness as the unmodified, undiluted (neat) block copolymer portion of the composition. The composition also shows enhanced thermal stability and processibility and is well suited for fabricating elastic moldings, films and fibers as well as for formulating with asphalts, adhesives and sealants. The novel thermoplastic elastomeric composition comprises (a) from about 50 to about 99 percent by weight of at least one block copolymer and (b) about 1 to about 50 percent by weight of at least one ethylene interpolymer having a density from about 0.855 g/cc to about 0.905 g/cc, wherein the ethylene interpolymer in the amount employed is a substantially inert extender of the block copolymer and the composition is further characterized as having:i. storage moduli throughout the range of -26° C. to 24° C. of less than about 3.5x109 dynes/cm2,ii. a ratio of storage modulus at -26° C. to storage modulus at 24° C. of less than about 4, andiii. storage moduli at -26° C. and 24° C. about 0.2 to about 3 times higher than the storage moduli at -26° C. and 24° C., respectively, of the neat block copolymer portion of the composition. |
