Polycarbonate-siloxane copolymer flame retarded with a silicone based core shell modifier

Patent metadata

Field	Value
Publication number	US-9309407-B2
Application number	US-201414261133-A
Country	US
Kind code	B2
Filing date	Apr 24, 2014
Priority date	May 2, 2013
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

Disclosed herein are compositions including a polycarbonate-siloxane copolymer and a silicone-based graft copolymer. The compositions may include one or more additional polymers, such as a bisphenol-A polycarbonate. The compositions may include additional components, such as anti-drip agents, and/or flame retardant salt additives. Also disclosed herein are articles including the compositions, methods of using the compositions, and processes for preparing the compositions.

First claim

What is claimed is:

1. A composition comprising:
a polycarbonate-siloxane copolymer having a weight average molecular weight of 28,000 Daltons to 32,000 Daltons and a siloxane content of 18 wt % to 22 wt %, the polycarbonate-siloxane copolymer present in the composition in an amount of about 25 wt %, based on the polycarbonate content of the composition;
one or more bisphenol-A polycarbonates having a weight average molecular weight of 17,000 Daltons to 31,000 Daltons, the one or more bisphenol-A polycarbonates present in the composition in an amount of about 75 wt %, based on the polycarbonate content of the composition;
a silicone-based graft copolymer comprising (a) 60% to 80% by weight of a silicone core component, and (b) a graft polymer shell derived from at least methacrylic ester monomer, the silicone-based graft copolymer present in the composition in an amount of about 2 wt % to about 4 wt %, based on the polycarbonate content of the composition;
styrene-acrylonitrile copolymer encapsulated polytetrafluoroethylene (TSAN), present in the composition in an amount of about 0.3 wt % to about 0.5 wt %, based on the polycarbonate content of the composition;
potassium diphenyl sulfone-3-sulfonate (KSS), present in the composition in an amount of about 0.25 wt % to about 0.35 wt %, based on the polycarbonate content of the composition; and
titanium dioxide, present in the composition in an amount of about 0.8 wt % to about 3.0 wt %, based on the polycarbonate content of the composition;
wherein a flame bar comprising the composition achieves a UL94 V0 rating at a thickness of 1.2 mm or 1.0 mm;
wherein the composition has a notched Izod impact strength (NII) of greater than or equal to 500 J/m, measured at −40° C. according to ASTM D 256; and
wherein the composition does not include aliphatic polyester-polycarbonate copolymers.

2. An article comprising the composition of claim 1 , the article selected from: components and housings for cell phones and other portable electronic devices, housings for medical devices, telecommunication enclosures, housings for outdoor electronics devices, solar collector components, and housings for scanners.

Assignees

• Sabic Innovative Plastics Ip
• Sabic Global Technologies Bv

Inventors

• Rosenquist Niles Richard

Classifications

• C08L83/10 Primary

  Block- or graft-copolymers containing polysiloxane sequences (obtained by polymerising a compound having a carbon-to-carbon double bond on to a polysiloxane C08L51/08, C08L53/00) · CPC title

• C08L2201/02

  Flame or fire retardant/resistant · CPC title

• C08L2666/02

  Organic macromolecular compounds, natural resins, waxes or and bituminous materials · CPC title

• C08L2666/24

  Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof · CPC title

• C08K5/0066

  Flame-proofing or flame-retarding additives · CPC title