US 6,281,286 B1 · Toughened thermoplastic resins

Abstract

A thermoplastic composition having a high impact strength is disclosed, said composition being prepared by (I) mixing (A) a thermoplastic selected from a polyester resin or a polyamide resin, (B) a silicone component comprising (B′) a diorganopolysiloxane gum having a plasticity of at least 30 and having an average of at least 2 alkenyl radicals in its molecule and (B″) a fumed silica filler, (C) an organohydrido silicon compound which contains an average of at least 2 silicon-bonded hydrogen groups in its molecule, and (D) a hydrosilation catalyst, components (C) and (D) being present in an amount sufficient to cure said diorganopolysiloxane; and (II) dynamically curing said diorganopolysiloxane gum. When the above composition is based on preferred poly(butylene terephthalate) resins, molded components thereof exhibit an Izod impact strength of at least 14 ft-lb (747 J/m), this high impact strength also being realized by blending the poly(butylene terephthalate) resin with a polycarbonate resin, the fumed silica then being an optional component.

Claims32

Dependent claims

A thermoplastic composition prepared by

(I) mixing components (A), (B), (C) and (D) and
(II) dynamically curing component (B), wherein the weight ratio of component (B) to component (A) in said thermoplastic composition is 10:90 to 35:65, and wherein
(A) is a thermoplastic resin selected from a poly(butylene terephthalate) resin, a blend of said poly(butylene terephthalate) resin and a polycarbonate resin, a polyester other than said poly(butylene terephthalate) resin or a polyamide resin;
(B) is a silicone component comprising
(i) a diorganopolysiloxane gum having a plasticity of at least 30 and having an average of at least 2 alkenyl radicals in its molecule and
(ii) a fumed silica filler, the weight ratio of said filler to said diorganopolysiloxane being 10:90 to 55:45,
with the proviso that said fumed silica filler is optional when (A) is said blend of poly(butylene terephthalate) resin and polycarbonate resin;
(C) is an organohydrido silicon compound which contains an average of at least 2 silicon-bonded hydrogen groups in its molecule;
and
(D) is a hydrosilation catalyst, components (C) and (D) being present in an amount sufficient to cure said diorganopolysiloxane,
with the proviso that when (A) is said poly(butylene terephthalate) resin said thermoplastic composition has an Izod impact strength of at least 747 J/m.

8 more elements

Dependencies are inferred from the claim text.

Toughened thermoplastic resins

Life of this patent

Toughened thermoplastic resins

Life of this patent

Abstract

Claims32