Thermoplastic Resin Composition

• US 20190330461A1
• Filed: 12/20/2017
• Published: 10/31/2019
• Est. Priority Date: 12/30/2016
• Status: Active Grant

• Current Assignee: Lotte Advanced Materials Co., Ltd. (Lotte Chemical Corporation)
• Original Assignee: Lotte Advanced Materials Co., Ltd. (Lotte Chemical Corporation)
• Inventors: KIM, Gi Sun, LEE, Seon Ae
• Granted Patent: US 11,136,449 B2
• Time in Patent Office: Days
• CPC Class Codes: C08K 2003/2296 of zinc
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08L 2201/08 Stabilised against heat, light or radiation or oxydation
• CPC Class Codes: C08L 2205/025 containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 2205/03 containing three or more polymers in a blend
• CPC Class Codes: C08L 25/12 with unsaturated nitriles
• CPC Class Codes: C08L 25/16 Homopolymers or copolymers of alkyl-substituted styrenes
• CPC Class Codes: C08L 55/02 ABS [Acrylonitrile-Butadiene-Styrene] polymers

Abstract

A thermoplastic resin composition of the present invention comprises: (A) 100 parts by weight of a thermoplastic resin comprising (A1) a rubber-modified aromatic vinyl-based graft copolymer, (A2) an aromatic vinyl-based copolymer resin having a flow index of about 5 g/10 min to about 8 g/10 min as measured by the ASTM D 1238 standard, and (A3) an α-methylstyrene copolymer; and (B) about 0.1 to about 10 parts by weight of zinc oxide, wherein the zinc oxide has a size ratio (B/A) of peak A in the region of 370 nm to 390 nm to peak B in the region of 450 nm to 600 nm of about 0.01 to about 1 in photoluminescence measurement, and has a BET surface area of about 10 m²/g or less as measured by a BET analyzer.

Claims

1. A thermoplastic resin composition comprising:

100 parts by weight of (A) a thermoplastic resin comprising (A1) a rubber-modified aromatic vinyl graft copolymer, (A2) an aromatic vinyl copolymer resin having a melt index (MI) of about 5 g/10 min to about 8 g/10 min, as measured in accordance with ASTM D 1238, and (A3) an α

-methylstyrene copolymer;

about 0.1 parts by weight to about 10 parts by weight of (B) zinc oxide,

wherein the zinc oxide has a peak intensity ratio (B/A) of about 0.01 to about 1, where A indicates a peak in the wavelength range of 370 nm to 390 nm and B indicates a peak in the wavelength range of 450 nm to 600 nm in photoluminescence measurement, and a BET surface area of about 10 m²/g or less, as measured using a BET analyzer.

2. The thermoplastic resin composition according to claim 1, wherein the (A2) aromatic vinyl copolymer resin has a weight average molecular weight of about 85,000 g/mol to about 150,000 g/mol.

3. The thermoplastic resin composition according to claim 1, wherein the (A3) α

-methylstyrene copolymer is a copolymer of about 65 wt % to about 80 wt % of α

-methylstyrene and about 20 wt % to about 35 wt % of acrylonitrile.

4. The thermoplastic resin composition according to claim 1, wherein the (A3) α

-methylstyrene copolymer has a weight average molecular weight of about 130,000 g/mol to about 180,000 g/mol.

5. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition satisfies Equation 1:

M_A2<

M_A3, 

 

[Equation 1]

where M_A2 is the weight average molecular weight of the (A2) aromatic vinyl copolymer resin and M_A3 is the weight average molecular weight of the (A3) α

-methylstyrene copolymer.

6. The thermoplastic resin composition according to claim 1, wherein the (A2) aromatic vinyl copolymer resin and the (A3) α

-methylstyrene copolymer are present in a weight ratio ((A2);

(A3)) of about 5;

1 to about 15;

1.

7. The thermoplastic resin composition according to claim 1, wherein the (A) thermoplastic resin comprises about 20 wt % to about 45 wt % of the (A1) rubber-modified aromatic vinyl graft copolymer;

about 40 wt % to about 75 wt % of the (A2) aromatic vinyl copolymer resin; and

about 3 wt % to about 15 wt % of the (A3) α

-methylstyrene copolymer.

8. The thermoplastic resin composition according to claim 1, wherein the zinc oxide has an average particle diameter (D50) of about 0.2 μ

m to about 3 μ

m.

9. The thermoplastic resin composition according to claim 1, wherein the zinc oxide has a peak position (2θ

) in the range of 35°

to 370 in X-ray diffraction (XRD) analysis and a crystallite size of about 1,000 Å

to about 2,000 Å

, as calculated by Equation 2;

10. The thermoplastic resin composition according to claim 1, wherein the zinc oxide has a peak intensity ratio (B/A) of about 0.01 to about 0.5, where A indicates a peak in the wavelength range of 370 nm to 390 nm and B indicates a peak in the wavelength range of 450 nm to 600 nm in measurement of photoluminescence.

11. The thermoplastic resin composition according to claim 1, wherein the (A3) α

-methylstyrene copolymer and the (B) zinc oxide are present in a weight ratio of about 1.5;

1 to about 15;

1.

12. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition has a total volatile organic compound (TVOC) of about 1,780 Area/g or less at 120°

C. for 5 hours, an impact strength of about 18 kgf cm/cm or more, as measured on a ⅛

″

thick specimen in accordance with ASTMD256, and an antibacterial activity against Staphylococcus aureus of about 2.0 to about 7.0 and an antibacterial activity against Escherichia coli of about 2.0 to about 7.5, as measured on 5 cm×

5 cm specimens inoculated with Staphylococcus aureus and Escherichia coli, respectively, in accordance with JIS Z 2801 and calculated according to Equation 3;

Antibacterial activity=log(M1/M2), 

 

[Equation 3]

wherein M1 is the number of bacteria as measured on a blank specimen after incubation under conditions of 35°

C. and 90% RH for 24 hours, and M2 is the number of bacteria as measured on a specimen of the thermoplastic resin composition after incubation under conditions of 35°

C. and 90% RH for 24 hours.

13. A molded article produced from the thermoplastic resin composition according to claim 1.