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

Patent metadata

Field	Value
Publication number	US-9803082-B2
Application number	US-201615220808-A
Country	US
Kind code	B2
Filing date	Jul 27, 2016
Priority date	Oct 31, 2012
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

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 powder comprising a polyorganosiloxane-containing graft copolymer (G2) obtained by graft polymerizing one or more vinyl monomers on a polyorganosiloxane-based rubber, wherein a particle diameter of the polyorganosiloxane-containing graft copolymer (G2) measured with absorptiometry is 300 nm to 2000 nm, an alkali metal content of the powder is 0 ppm to 20 ppm, and an alkaline earth metal content of the powder is 0 ppm to 150 ppm,
wherein a resin composition comprising the polyorganosiloxane-containing graft copolymer (G2) is prepared under production condition 11 and has a number of generated silver streaks measured under an evaluation condition 12 of 0,
wherein the production condition 11 for the resin composition and a test piece comprises:
mixing the following (1)-(5):
(1) 4 mass parts of the powder of the polyorganosiloxane-containing graft copolymer (G2);
(2) 96 mass parts of an aromatic polycarbonate resin having a viscosity average molecular weight of 22,000;
(3) 0.1 mass part of octadecyl 3,5-di-t-butyl-4-hydroxylbenzene propionate;
(4) 0.1 mass part of tris(2,4-di-t-butylphenyl)phosphite; and
(5) 0.1 mass part of carbon black having primary particle size of 16 nm, nitrogen absorption surface area of 260 m 2 /g, tinting strength of 147%, and powder oil absorption of 69 cm 3 /100 g;

providing the mixture to a devolatilizing extruder heated to a barrel temperature of 280° C.;
kneading the mixture under a condition of a screw speed of 150 rpm to obtain particles of the resin composition;
molding the particles under conditions of a material cylinder temperature of 310° C., a hot runner temperature of 310° C., and a mold temperature of 90° C. using a 100 ton injection molding machine and a mold having a hot runner (test piece dimensions: longitude: 100 mm×transverse: 100 mm×thickness: 2 mm, pin gate) to produce an injection molded article of a first shot; and
molding after the first-shot molding of the injection molding machine and after the resin composition is kept in the injection molding machine for 6 min to perform another shot of molding to obtain a test piece 11;
wherein the evaluation condition 12 comprises:
visually confirming a number of silver streaks generated near a gate of the test piece 11.

2. The powder of claim 1 , wherein a sulfur content of the powder is 0 ppm to 200 ppm.

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

4. The powder of claim 1 , wherein the vinyl monomers form a monomer mixture containing an aromatic vinyl monomer.

5. The powder of claim 1 , wherein an sp value of the graft part of the polyorganosiloxane-containing graft copolymer (G2) calculated with the Fedors method is 20.15 to 21.00.

6. The powder of claim 1 , wherein the vinyl monomers form a monomer mixture containing a crosslinking monomer.

7. The powder of claim 1 , wherein the resin composition prepared under the production condition 11 has 20 or less of an L* value measured under evaluation condition 13,
wherein the evaluation condition 13 comprises:
molding the particles of the resin composition under conditions of a material cylinder temperature of 310° C. and a mold temperature of 90° C. to obtain a test piece 13 (length: 100 mm, width: 50 mm, thickness: 2 mm) in a 100 ton injection molding machine,
measuring in accordance with JIS Z 8729 (a display method for an object color in a L*a*b* color system) an object color of the test piece 13 based on JISZ8722 below using a spectroscopic colorimeter under conditions of
an apparatus of a spectroscopic colorimeter (with after-sample light splitting of 0°-45°),
a measurement range of 380 nm to 780 nm, and
a measurement light source of C light (2° field of view),
wherein the L* value is calculated according to tristimulus values (XYZ) using a CIE color difference formula.

8. A resin composition containing the powder of claim 1 and a resin.

9. The resin composition of claim 8 , wherein in 100 mass % of the resin composition, the content of the powder of the polyorganosiloxane-containing graft copolymer (G2) is 0.5 mass % to 90 mass %.

10. The resin composition of claim 8 , wherein the resin is a thermoplastic resin.

11. The resin composition of claim 10 , wherein the thermoplastic resin is an aromatic polycarbonate resin.

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

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

14. A molded article obtained by molding the resin composition of claim 10 .

15. The powder of claim 1 , wherein the vinyl monomers form a monomer mixture containing an aromatic vinyl monomer, an alkali metal content of the powder is 0 ppm to 20 ppm, and an alkaline earth metal content of the powder is 0 ppm to 150 ppm.

16. The powder of claim 15 , wherein a sulfur content of the powder is 0 ppm to 200 ppm.

Assignees

• Mitsubishi Rayon Co
• Mitsubishi Chem Corp

Inventors

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

Classifications

• C08K3/016

  Flame-proofing or flame-retarding additives · CPC title

• C08L27/12

  containing fluorine atoms · CPC title

• C08L2201/02

  Flame or fire retardant/resistant · CPC title

• C08L51/085

  on to polysiloxanes · CPC title

• C08G2261/62

  Mechanical aspects · CPC title