JP-2026074495-A - Polycarbonate resin composition

Abstract

[Problem] A polycarbonate resin composition that has excellent impact resistance and metallic appearance, and does not produce flow streaks during molding. [Solution] A polycarbonate resin composition comprising 100 parts by mass of (A) and (B) in total, containing 50 to 100 parts by mass of polycarbonate resin (A) and 0 to 50 parts by mass of polyester resin (B), wherein the composition contains 2.0 to 5.0 parts by mass of a metal pigment (C) mainly composed of aluminum, 6.0 to 15.0 parts by mass of thermoplastic elastomer (D), and 0.5 to 1.5 parts by mass of organic particles (E), wherein the metal pigment (C) contains a metal pigment (c1) with an average particle diameter of 1 μm or more and less than 13 μm, and a metal pigment (c2) with an average particle diameter of 13 μm or more and 30 μm or less. [Selection Diagram] None

Inventors

• 鈴木 健太郎
• 西林 豊

Assignees

• 三菱エンジニアリングプラスチックス株式会社

Dates

Publication Date

20260507

Application Date

20241021

Claims (6)

1. A polycarbonate resin composition comprising 50 to 100 parts by mass of polycarbonate resin (A) and 0 to 50 parts by mass of polyester resin (B), totaling 100 parts by mass of (A) and (B), wherein the composition contains 2.0 to 5.0 parts by mass of a metal pigment (C) mainly composed of aluminum, 6.0 to 15.0 parts by mass of thermoplastic elastomer (D), and 0.5 to 1.5 parts by mass of organic particles (E), characterized in that the metal pigment (C) contains a metal pigment (c1) with an average particle diameter of 1 μm or more and less than 13 μm, and a metal pigment (c2) with an average particle diameter of 13 μm or more and 30 μm or less.
2. The polycarbonate resin composition according to claim 1, wherein the mass ratio (c1)/(c2) of the content of metal pigments (c1) and (c2) is greater than 1.0.
3. Furthermore, the polycarbonate resin composition according to claim 1 or 2, further containing 0.005 to 0.5 parts by mass of hydrogen siloxane (F) per 100 parts by mass of the total of the polycarbonate resin (A) and the polyester resin (B).
4. A molded article obtained by molding the polycarbonate resin composition according to claim 1 or 2.
5. Pellets of the polycarbonate resin composition according to claim 1 or 2.
6. A molded article obtained by molding the polycarbonate resin composition pellets described in claim 5.

Description

This invention relates to a polycarbonate resin composition, and more specifically, to a polycarbonate resin composition and molded articles thereof that exhibit excellent impact resistance and metallic appearance, and that do not produce flow streaks during molding. Polycarbonate resin possesses excellent mechanical, electrical, and heat-resistant properties, and is used in a wide range of fields, including automobiles, office automation equipment, electrical and electronic components, building materials, and household goods. Furthermore, when polycarbonate resin is used as a metal substitute material, a polycarbonate resin composition having a metallic appearance is preferred. Molded articles having a metallic appearance include those made from a polycarbonate resin composition that does not have a metallic appearance and is then metallic painted or metal-plated, and molded articles made from a polycarbonate resin composition that has a metallic appearance. Among these, from the viewpoint of manufacturing efficiency and other factors, molded articles made from a polycarbonate resin composition that has a metallic appearance are preferable. Polycarbonate resin compositions having a metallic appearance generally contain particles with metallic luster. For example, Patent Document 1 describes a polycarbonate resin composition in which metal-coated glass flakes are blended with polycarbonate resin in a predetermined ratio. However, resin compositions containing metallic pigments or the like tend to experience a decrease in the molecular weight of the polycarbonate resin during melting and mixing, leading to a decrease in impact resistance. Furthermore, Patent Document 2 by the present applicant proposes a polycarbonate resin composition containing an organic phosphate ester compound and a plate-shaped pigment mainly composed of aluminum, with specified material, average particle size, aspect ratio, and iron content, which can be used to produce molded articles with a metallic appearance and excellent resistance to moisture and heat, and which exhibits excellent heat retention stability. However, the specifications required for metallic finishes in recent years have become extremely sophisticated. For example, to create a more luxurious feel, such as a satin finish, there is a demand for a deep metallic look with excellent luster and high gloss. Even if a metallic finish is present, a strong grainy texture from the metallic pigments, i.e., a highly granular texture, is undesirable. Furthermore, in the case of products with a metallic appearance, such as automotive interior parts, bosses and other features are usually provided on the back side. However, these areas present a problem in that metallic pigments appear in streaks during molding, making them prone to flow streaks. Japanese Patent Publication No. 2002-038000Japanese Patent Publication No. 2013-139516 The present invention will be described in detail below with reference to embodiments and examples. In this specification, unless otherwise specified, "~" means that the numbers before and after it are included as the lower and upper limits, respectively. The polycarbonate resin composition of the present invention contains 50 to 100 parts by mass of polycarbonate resin (A) and 0 to 50 parts by mass of polyester resin (B), totaling 100 parts by mass of (A) and (B). It also contains 2.0 to 5.0 parts by mass of a metal pigment (C) mainly composed of aluminum, 6.0 to 15.0 parts by mass of thermoplastic elastomer (D), and 0.5 to 1.5 parts by mass of organic particles (E). The metal pigment (C) is characterized by containing a metal pigment (c1) with an average particle diameter of 1 μm or more and less than 13 μm, and a metal pigment (c2) with an average particle diameter of 13 μm or more and 30 μm or less. [Polycarbonate resin (A)] The polycarbonate resin (A) used in the present invention is not particularly limited, and various types can be used. Polycarbonate resins can be classified into aromatic polycarbonate resins, in which the carbons directly bonded to the carbonate bonds are aromatic carbons, and aliphatic polycarbonate resins, in which the carbons are aliphatic carbons, and either can be used. Among these, aromatic polycarbonate resin is preferred as the polycarbonate resin (A) from the viewpoint of heat resistance, mechanical properties, electrical properties, etc. Examples of aromatic dihydroxy compounds among the monomers used as raw materials for aromatic polycarbonate resins include: Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e., resorcinol), and 1,4-dihydroxybenzene; Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl; Dihydroxynaphthalene compounds such as 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphth