Polyorganosiloxane-containing graft copolymer, resin composition, and molded article

Patent metadata

Field	Value
Publication number	US-9527997-B2
Application number	US-201314439745-A
Country	US
Kind code	B2
Filing date	Jun 28, 2013
Priority date	Oct 31, 2012
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A graft copolymer capable of providing impact resistance, flame retardance, and color rendering properties to a thermoplastic resin is described. The graft copolymer contains a polyorganosiloxane, and is obtained by graft-polymerizing vinyl monomers including a (meth)acrylate ester (b 1 ) having an alkyl group or an aromatic group and an aromatic vinyl monomer (b 2 ) on a polyorganosiloxane-based rubber. The graft copolymer has a volume average particle diameter of 200-2000 nm, and contains 0.1-69 mass % of polyorganosiloxane. A thermoplastic resin composition is also described, containing a thermoplastic resin (A), the graft copolymer, a fluorine resin (C) and a flame retardant (D). A molded article is also described, which is obtained by molding the thermoplastic resin composition.

First claim

The invention claimed is:

1. A polyorganosiloxane-containing graft copolymer, which is a polyorganosiloxane-containing graft copolymer (G1) formed by graft polymerizing a vinyl monomer mixture on a polyorganosiloxane-based rubber,
wherein
the vinyl monomer mixture contains a (meth)acrylate ester (b 1 ) and an aromatic vinyl monomer (b 2 ),
the (meth)acrylate ester (b 1 ) has an alkyl group or an aromatic group, a volume average particle diameter of the graft copolymer (G1) is 200 nm to 2000 nm, and
a content of the polyorganosiloxane is 0.1 mass % to 69 mass % based on 100 mass % of the graft copolymer (G1),

wherein
regarding test pieces produced under production condition 1 below, a Charpy impact strength [kJ/m 2 ], a total light transmittance [%], and a flame retardance measured under evaluation condition 2 below meet performance conditions 1) to 3):
1) 15≦Charpy impact strength≦70,
2) 60≦Charpy impact strength+total light transmittance×1.36, and
3) the flame retardance of a thickness of 1/16 inch in a vertical flame test of UL94 standard being “V-1” or above,

wherein
the production condition 1 for the test pieces comprises:
providing a resin composition obtained by mixing
1) an aromatic polycarbonate resin having a viscosity average molecular weight of 22,000 in 100 mass parts,
2) the polyorganosiloxane-containing graft copolymer (G1) in 5.5 mass parts,
3) an acrylic acid-modified polytetrafluoroethylene in 0.5 mass part, and
4) an aromatic phosphate-based flame retardant in 5.5 mass parts
to a devolatilizing extruder heated to a barrel temperature of 280° C.,
performing kneading under a condition of a screw speed of 150 rpm to obtain particles,
providing the particles to a 100 ton injection molding machine, and
performing molding under conditions of a material cylinder temperature of 280° C. and a mold temperature of 90° C. to obtain the following test pieces:
i) a test piece 1 (length: 80.0 mm, width: 10.0 mm, thickness: 4 mm, provided with a V-shaped notch) provided with a Charpy notch for the impact strength evaluation,
ii) a test piece 2 (length: 100 mm, width: 50 mm, thickness: 2 mm) for the total light transmittance evaluation, and
iii) a test piece 3 (length: 127 mm, width: 12.7 mm, thickness: 1.6 mm) having a thickness of 1/16 inch for the flame retardance evaluation;
and the evaluation condition 2 comprises:
measuring the Charpy impact strength (kJ/m 2 ) of the test piece 1 according to JIS K 7111-1/1eA at a temperature of −30° C.,
measuring the total light transmittance (%) of the test piece 2 to a D65 light source using a hazemeter based on JIS K 7375, and
measuring, for the flame retardance, a total burn time of five test pieces 3 according to a vertical flame test method of a UL94V test.

2. The polyorganosiloxane-containing graft copolymer of claim 1 , wherein the vinyl monomer mixture contains 2 to 95 mass % of the aromatic vinyl monomer (b 2 ).

3. The polyorganosiloxane-containing graft copolymer of claim 1 , wherein the polyorganosiloxane-based rubber is a composite rubber containing the polyorganosiloxane and a polyalkyl(meth)acrylate (PA).

4. A thermoplastic resin composition, containing: a thermoplastic resin (A), the polyorganosiloxane-containing graft copolymer (G1) of claim 1 , a fluorine resin (C), and a flame retardant (D).

5. The thermoplastic resin composition of claim 4 , wherein the thermoplastic resin (A) is a thermoplastic resin having at least one bond selected from a carbonate bond, an ester bond, and an amide bond.

6. The thermoplastic resin composition of claim 4 , wherein the thermoplastic resin (A) is a polycarbonate-based resin.

7. The thermoplastic resin composition of claim 4 , wherein the flame retardant (D) contains at least one flame retardant selected from a phosphorus-based flame retardant and an organic metal salt-based flame retardant.

8. A molded article obtained by molding the thermoplastic resin composition of claim 4 .

9. A molded article obtained by molding the thermoplastic resin composition of claim 7 .

Assignees

• Mitsubishi Rayon Co

Inventors

• Wakita Ayaka
• Fujikawa Yuichiro
• Ueki Sohei
• Matsuoka Shinji

Classifications

• C08L27/12

  containing fluorine atoms · CPC title

• C08K3/016

  Flame-proofing or flame-retarding additives · CPC title

• C08L69/00 Primary

  Compositions of polycarbonates; Compositions of derivatives of polycarbonates · CPC title

• C08G77/445

  containing polyester sequences · CPC title

• C08L51/085

  on to polysiloxanes · CPC title