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US-20260125537-A1 - POLYCARBONATE RESIN COMPOSITION

US20260125537A1US 20260125537 A1US20260125537 A1US 20260125537A1US-20260125537-A1

Abstract

A polycarbonate resin composition including: a 55 to 90 mass % polycarbonate resin (A) having a viscosity-average molecular weight of 17500 to 30000; a 10 to 45 mass % graft copolymer (B) containing an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene rubber polymer component (b3); and, relative to a total mass of (A) and (B) being 100 parts by mass, 0.001 to 0.3 parts by mass of a triaryl phosphate (C) given by specific general formula (1); and 0.001 to 0.3 parts by mass of a phenolic structure-bearing compound (D), wherein the phenolic structure-bearing compound (D) contains at least one of 4-t-butylphenol, 2,4-di-t-butylphenol, 4-α-cumylphenol, and bisphenol A.

Inventors

  • Satoshi Mochida

Assignees

  • MITSUBISHI ENGINEERING-PLASTICS CORPORATION

Dates

Publication Date
20260507
Application Date
20230905
Priority Date
20220929

Claims (9)

  1. 1 : A polycarbonate resin composition, comprising: 55 to 90 mass % of a polycarbonate resin (A) having a viscosity-average molecular weight of 17500 to 30000; 10 to 45 mass % of a graft copolymer (B) comprising an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene rubber polymer component (b3); and, relative to a total mass of (A) and (B) being 100 parts by mass, 0.001 to 0.3 parts by mass of a triaryl phosphate (C) given by formula (1); and 0.001 to 0.3 parts by mass of a phenolic structure-bearing compound (D) comprising at least one of 4-t-butylphenol, 2,4-di-t-butylphenol, 4-α-cumylphenol, and bisphenol A: where R 1 to R 5 on each of aromatic rings are independently a hydrogen atom or a C 1-12 alkyl group.
  2. 2 : The polycarbonate resin composition of claim 1 , wherein at least one of the R 1 to R 5 on each of the aromatic rings in the formula (1) is a C 1-12 alkyl group.
  3. 3 : The polycarbonate resin composition of claim 1 , wherein the R 1 and R 3 on each of the aromatic rings in the formula (1) are a C 1-12 alkyl group, and the R 2 , R 4 and R 5 on each of the aromatic rings are hydrogen atoms.
  4. 4 : The polycarbonate resin composition of claim 3 , wherein the R 1 and R 3 on each of the aromatic rings in the formula (1) are a t-butyl group.
  5. 5 : The polycarbonate resin composition of claim 1 , wherein the triaryl phosphate (C) comprises at least one of triphenyl phosphate, tris-2,4-di-t-butylphenylphosphate, and tris-4-t-butylphenylphosphate.
  6. 6 : The polycarbonate resin composition of claim 1 , further comprising: 0.001 to 0.3 parts by mass of a triaryl phosphite (E) relative to the total mass of (A) and (B) being 100 parts by mass.
  7. 7 : A pellet, comprising the polycarbonate resin composition of claim 1 .
  8. 8 : A molded article, comprising the polycarbonate resin composition of claim 1 .
  9. 9 : A molded article, comprising the pellet of claim 7 .

Description

TECHNICAL FIELD The present invention relates to a polycarbonate resin composition and more particularly to a polycarbonate resin composition with excellent weathering resistance, and to a molded article of this polycarbonate resin composition. BACKGROUND ART Polycarbonate resin has excellent mechanical properties, e.g., impact resistance and so forth, and also has excellent heat resistance, excellent transparency and so forth, and as a result is widely used in numerous applications, e.g., various optical components, components in electric and electronic equipment, automotive interior and exterior trim components, OA equipment components, sheets, mechanical components, building materials and so forth. However, polycarbonate resin has a somewhat limited use due to its poor weathering resistance. For example, its outdoor use or indoor use under fluorescent lights causes discoloration or strength reduction of the product. To solve this problem, various light stabilizers have conventionally been used alone or in combination. A known example of such light stabilizers is a benzotriazole-based ultraviolet absorber. However, blending such an ultraviolet absorber with polycarbonate resin causes another problem, that is, a decreased hue of a polycarbonate resin composition, which is induced by heat deterioration during melt kneading and molding operations. Further, there have been attempts to blend various additives with polycarbonate resin to impart high functionality. For example, PTL 1 describes that fiber-reinforced polycarbonate resin compositions excellent in dimensional stability, mechanical strength and fluidity can be obtained by the admixture of 5 to 15 mass % triphenyl phosphate in 85 to 95 mass % polycarbonate resin. With the rapid development in recent years of greater functionality and higher performance by various devices and equipment, an improvement in particular in the weathering resistance of polycarbonate resin is strongly desired. CITATION LIST Patent Literature [PTL 1] Japanese Patent No. 3308657 SUMMARY OF INVENTION Technical Problem An object of (problem for) the present invention is to provide a polycarbonate resin composition that exhibits excellent weathering resistance, favorable impact and heat resistance, and good fluidity (moldability). Solution to Problem As a result of extensive and intensive investigations in order to address this problem, the present inventor has made the present invention upon discovering that excellent weathering resistance as well as favorable impact and heat resistance is exhibited by a polycarbonate resin composition that contains a prescribed triaryl phosphate compound in a small amount relative to an polymer alloy of polycarbonate and a graft polymer such as an ABS resin. The present invention relates to a polycarbonate resin composition and a molded article described below. 1. A polycarbonate resin composition, comprising: 55 to 90 mass % of a polycarbonate resin (A) having a viscosity-average molecular weight of 17500 to 30000; 10 to 45 mass % of a graft copolymer (B) comprising an aromatic vinyl monomer component (b1), a vinyl cyanide monomer component (b2), and a diene rubber polymer component (b3); and, relative to a total mass of (A) and (B) being 100 parts by mass,0.001 to 0.3 parts by mass of a triaryl phosphate (C) given by general formula (1); and 0.001 to 0.3 parts by mass of a phenolic structure-bearing compound (D),wherein the phenolic structure-bearing compound (D) comprises at least one of 4-t-butylphenol, 2,4-di-t-butylphenol, 4-α-cumylphenol, and bisphenol A. [C1] (In formula (1), R1 to R5 are independently a hydrogen atom or a C1-12 alkyl group.) 2. The polycarbonate resin composition of the above 1, wherein at least one of the R1 to R5 on each of aromatic rings in formula (1) is a C1-12 alkyl group.3. The polycarbonate resin composition of the above 1, wherein the R1 and R3 on each of the aromatic rings in formula (1) are a C1-12 alkyl group, and the R2, R4 and R5 on each of the aromatic rings are a hydrogen atom.4. The polycarbonate resin composition of the above 3, wherein the R1 and R3 on each of the aromatic rings in formula (1) are a t-butyl group, and the R2, R4 and R5 on each of the aromatic rings are a hydrogen atom.5. The polycarbonate resin composition of the above 1, wherein the triaryl phosphate (C) contains at least one of triphenyl phosphate, tris(2,4-di-t-butylphenyl)phosphate, and tris(4-t-butylphenyl)phosphate.6. The polycarbonate resin composition of the above 1, further including 0.001 to 0.3 parts by mass of a triaryl phosphite (E) relative to the total mass of (A) and (B) being 100 parts by mass.7. A pellet comprising the polycarbonate resin composition of any one of the above 1 to 6.8. A molded article comprising the polycarbonate resin composition of any one of the above 1 to 6.9. A molded article comprising the pellet of the polycarbonate resin composition of the above 7. Advantageous Effects of Invention The polycar