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

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 .