Patent ID: 6417293
Filing Date: 2002-07-09
Classification: C08G,C08K,C08L

Abstract:
A method for preparing a thermoplastic elastomer, said method comprising:(I) mixing (A) a thermoplastic resin comprising more than 50 percent by volume of a polyester resin other than poly(butylene terephthalate), said thermoplastic resin having a softening point of 23Â° C. to 300Â° C., (B) a silicone elastomer comprising (Bâ€²) 100 parts by weight of a diorganopolysiloxane gum having a williams plasticity number of at least 30 and having an average of at least 2 alkenyl groups in its molecule and, optionally, (Bâ€³) up to 200 parts by weight of a reinforcing filler, the weight ratio of said silicone elastomer to said thermoplastic resin being greater than 35:65 to 85:15, (C) 0.02 to 5 parts by weight of a stabilizer for each 100 parts by weight of said thermoplastic resin and said silicone elastomer, said stabilizer being selected from hindered phenols; thioesters; hindered amines; 2,2â€²-(1,4-phenylene)bis(4H-3, 1-benzoxazin-4-one); or 3,5-di-tert-butyl-4-hydroxybenzoic acid, hexadecyl ester, (D) an organohydrido silicon compound which contains an average of at least 2 silicon-bonded hydrogen groups in its molecule and (E) a hydrosilation catalyst, components (D) and (E) being present in an amount sufficient to cure said diorganopolysiloxane (Bâ€²); and (II) dynamically curing said diorganopolysiloxane (Bâ€²), wherein at least one property of the thermoplastic elastomer selected from tensile strength or elongation is at least 25% greater than the respective property for a corresponding simple blend wherein said diorganopolysiloxane is not cured and said thermoplastic elastomer has an elongation of at least 30%.