Thermoplastic resin composition and molded article therefrom

Abstract

A thermoplastic resin composition according to the present invention comprises: about 100 parts by weight of a polycarbonate resin; about 5 to about 100 parts by weight of an inorganic filler; about 0.1 to about 2 parts by weight of a maleic anhydride-modified olefin-based copolymer; and about 0.1 to about 2 parts by weight of a phosphite compound represented by chemical formula 1. The thermoplastic resin composition is excellent in terms of chemical resistance, impact resistance, rigidity, physical property balance thereof, and the like.

Claims

1. A thermoplastic resin composition comprising: about 100 parts by weight of a polycarbonate resin; about 5 to about 100 parts by weight of inorganic fillers; about 0.1 to about 2 parts by weight of a maleic anhydride modified olefin copolymer; and about 0.1 to about 2 parts by weight of a phosphite compound represented by the following Formula 1: ##STR00008## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are each independently a hydrogen atom or a C.sub.1 to C.sub.10 alkyl group, and A is a sulfur atom or an oxygen atom.

2. The thermoplastic resin composition according to claim 1, wherein the inorganic fillers include glass fiber, talc, wollastonite, whisker, silica, mica and/or basalt fiber.

3. The thermoplastic resin composition according to claim 1, wherein the maleic anhydride modified olefin copolymer comprises a maleic anhydride modified alkylene-α-olefin copolymer obtained by graft copolymerization of maleic anhydride to an alkylene-α-olefin copolymer.

4. The thermoplastic resin composition according to claim 1, wherein the maleic anhydride modified olefin copolymer comprises a maleic anhydride modified ethylene-butene copolymer and/or a maleic anhydride modified ethylene-octene copolymer.

5. The thermoplastic resin composition according to claim 1, wherein one or more of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 comprises a C.sub.4 to C.sub.10 branched alkyl group and one or more of R.sub.5, R.sub.6, R.sub.7 and R.sub.8 comprises a C.sub.4 to C.sub.10 branched alkyl group.

6. The thermoplastic resin composition according to claim 1, wherein the phosphite compound comprises a compound represented by the following Formula 1a: ##STR00009##

7. The thermoplastic resin composition according to claim 1, wherein the maleic anhydride modified olefin copolymer and the phosphite compound are present in a weight ratio of about 1:0.1 to about 1:3.

8. The thermoplastic resin composition according to 1, wherein the thermoplastic resin composition further comprises a modified polyolefin having a repeat unit represented by Formula 2 and a repeat unit represented by Formula 3: ##STR00010## wherein in Formula 3, R.sub.1 is a hydrogen atom or a methyl group and Y is —COOR.sub.2 wherein R.sub.2 is a C.sub.1 to C.sub.12 alkyl group, a glycidyl-modified ester group, an arylate group, or a nitrile group (—CN).

9. The thermoplastic resin composition according to claim 8, wherein the modified polyolefin is present in an amount of about 1 to about 10 parts by weight, relative to about 100 parts by weight of the polycarbonate resin.

10. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition has a fracture height of about 60 cm to about 90 cm, as measured on a 1 mm thick specimen using a drop impact tester in accordance with the DuPont drop test by dipping the specimen in a thinner solution for 2.5 minutes, drying the specimen at 80° C. for 20 minutes, allowing the specimen to be left at room temperature for 24 hours, and measuring a height, at which dropping a 1 kg dart results in breakage of the specimen.

11. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition has a notched Izod impact strength of about 10 kgf.Math.cm/cm to about 30 kgf.Math.cm/cm, as measured on a ⅛″ thick specimen in accordance with ASTM D256.

12. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition has a flexural modulus of about 30,000 kgf/cm.sup.2 or more, as measured on a ¼″ thick specimen at a rate of 2.8 mm/min in accordance with ASTM D790.

13. A molded article formed of the thermoplastic resin composition according to claim 1.

Description

MODE FOR INVENTION

(1) Next, the present invention will be described in more detail with reference to some examples. It should be understood that these examples are provided for illustration only and are not to be in any way construed as limiting the present invention.

Example

(2) Details of components used in Examples and Comparative Examples are as follows:

(3) (A) Polycarbonate Resin

(4) A bisphenol-A polycarbonate resin (weight average molecular weight: 22,000 g/mol) was used.

(5) (B) Inorganic Fillers

(6) (B1) Glass fiber (flat type, Manufacturer: NITTOBO, Product Name: CSG 3PA-832) was used.

(7) (B2) Glass fiber (round type, Manufacturer: Owens Corning, Product Name: 183F) was used.

(8) (C) Modified Olefin Copolymer

(9) (C1) Maleic anhydride modified ethylene-butene copolymer (Manufacturer: Mitsui Chemicals, Product Name: TAFMER MH-7020) was used.

(10) (C2) Glycidyl methacrylate modified ethylene-butyl acrylate copolymer (Manufacturer: DuPont, Product Name: Elvaroy PTW) was used.

(11) (D) Phosphite Compound

(12) (D1) Phosphite compound represented by Formula 1a was used.

(13) ##STR00007##

(14) (D2) Triphenyl phosphite compound was used.

(15) (D3) Tri(2,4-di-tert-butylphenyl)phosphite compound was used.

(16) (D4) Tri(4-methoxyphenyl)phosphite compound was used.

(17) (E) Modified Polyolefin

(18) Ethylene/methyl acrylate copolymer (Manufacturer: Dupont, Product Name: Elvaloy AC1330) was used.

Examples 1 to 6 and Comparative Examples 1 to 8

(19) The aforementioned components were mixed in amounts as listed in Tables 1 and 2, followed by extrusion at 250° C., thereby preparing a thermoplastic resin composition in pellet form. Here, extrusion was performed using a twin-screw extruder (L/D: 36, Φ: 45 mm). The prepared pellets were dried at 100° C. for 4 hours or more and then subjected to injection molding using a 10 oz. injection machine (molding temperature: 300° C.), thereby preparing a specimen. The prepared specimen was evaluated as to the following properties. Results are shown in Tables 1 and 2.

(20) Property Evaluation

(21) (1) Chemical resistance (post-painting impact resistance): 1 mm thick specimen was dipped in a thinner solution for 2.5 minutes, dried at 80° C. for 20 minutes, and left at room temperature for 24 hours, followed by measurement of a height (unit: cm), at which dropping a 1 kg dart resulted in breakage of the specimen, using a drop impact tester in accordance with the DuPont drop test.

(22) (2) Notched Izod impact strength (unit: kgf.Math.cm/cm): Notched Izod impact strength was measured on a ⅛″ thick Izod specimen in accordance with ASTM D256.

(23) (3) Flexural modulus (FM, unit: kgf/cm.sup.2): flexural modulus was measured on a ¼″ thick specimen at a rate of 2.8 mm/min in accordance with ASTM D790.

(24) TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 6 (A) (parts by weight) 100 100 100 100 100 100 (B1) (parts by weight) 10 10 10 10 10 — (B2) (parts by weight) — — — — — 10 (C1) (parts by weight) 0.7 0.5 1.0 0.5 0.5 0.5 (C2) (parts by weight) — — — — — — (D1) (parts by weight) 0.6 0.6 0.6 0.2 1.0 0.6 (D2) (parts by weight) — — — — — — (D3) (parts by weight) — — — — — — (D4) (parts by weight) — — — — — — (E) (parts by weight) 3 3 3 3 3 3 Fracture height (cm) 75 72 75 70 70 75 Notched Izod impact 17 15 17 16 15 18 strength (kgf .Math. cm/cm) Flexural modulus 31,200 32,500 31,000 32,000 33,000 33,500 (kgf/cm.sup.2)

(25) TABLE-US-00002 TABLE 2 Comparative Example 1 2 3 4 5 6 7 8 (A) (parts by weight) 100 100 100 100 100 100 100 100 (B1) (parts by weight) 10 10 10 10 10 10 10 10 (B2) (parts by weight) — — — — — — — — (C1) (parts by weight) 0.05 2.5 — 0.5 0.5 0.5 0.5 0.5 (C2) (parts by weight) — — 0.5 — — — — — (D1) (parts by weight) 0.6 0.6 0.6 0.05 2.5 — — — (D2) (parts by weight) — — — — — 0.6 — — (D3) (parts by weight) — — — — — — 0.6 — (D4) (parts by weight) — — — — — — — 0.6 (E) (parts by weight) 3 3 3 3 3 3 3 3 Fracture height (cm) 57 78 55 48 55 42 45 42 Notched Izod impact 15 17 15 17 12 16 15 17 strength (kgf .Math. cm/cm) Flexural modulus 33,500 28,500 32,500 32,000 32,000 32,500 32,500 32,000 (kgf/cm.sup.2)

(26) From the results shown in Table 1, it can be seen that the thermoplastic resin composition according to the present invention had good properties in terms of chemical resistance (post-painting impact resistance), impact resistance, rigidity and balance therebetween.

(27) In contrast, it could be seen that the composition of Comparative Example 1 prepared using a smaller amount of the maleic anhydride modified olefin copolymer suffered from deterioration in chemical resistance and the like; the composition of Comparative Example 2 prepared using an excess of the maleic anhydride modified olefin copolymer suffered from deterioration in rigidity, and the like; and the composition of Comparative Example 3 prepared using the glycidyl methacrylate modified ethylene-butyl acrylate copolymer (C2) instead of the maleic anhydride modified olefin copolymer suffered from deterioration in chemical resistance and the like. It could be seen that the composition of Comparative Example 4 prepared using a small amount of the phosphite compound suffered from deterioration in chemical resistance and the like; the composition of Comparative Example 5 prepared using an excess of the phosphite compound suffered from deterioration in chemical resistance and exhibited relatively low impact resistance; and the compositions of Comparative Examples 6, 7 or 8 prepared using the phosphite compound (D2), (D3) or (D4) instead of the phosphite compound according to the present invention suffered from deterioration in chemical resistance, and the like.

(28) It should be understood that various modifications, changes, alterations, and equivalent embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention.