US-12624205-B2 - Polycarbonate resin composition and optical molded article comprising the same

US12624205B2US 12624205 B2US12624205 B2US 12624205B2US-12624205-B2

Abstract

The present disclosure relates to a polycarbonate resin composition exhibiting excellent heat stability and optical properties, and an optical molded article comprising the same. The polycarbonate resin composition includes polycarbonate resin; and [[4-(dimethylamino)phenyl]methylene] propanedioic acid dimethyl ester as a hindered amine UV absorber that selectively absorbs UVA having a wavelength of 420 nm or less.

Inventors

Byoungkue JEON
Young In Yang
Daehyeon HWANG
Mooho Hong
Ki Jae Lee
Youngwook SON

Assignees

LG CHEM, LTD.

Dates

Publication Date: 20260512
Application Date: 20190819
Priority Date: 20180820

Claims (7)

1 . A polycarbonate resin composition comprising: 95 to 99.99 wt % of polycarbonate resin having a melt flow rate (MFR) according to ASTM D1238 of 5 to 15 g/10 min; and 0.02 to 0.1 wt % of [[4-(dimethylamino)phenyl]methylene] propanedioic acid dimethyl ester as a hindered amine UV absorber that selectively absorbs ultraviolet ray A (UVA) having a wavelength of 420 nm or less, wherein the polycarbonate resin is a linear polycarbonate homopolymer consisting essentially of repeating units derived from bisphenol A, wherein the polycarbonate resin has a weight average molecular weight of 32,000 g/mol to 60,000 g/mol, wherein the polycarbonate resin composition has a transmittance of UV having a wavelength of 420 nm measured according to ASTM D1003 of 26% or less, and wherein the polycarbonate resin composition has a yellow index change value (ΔYI) represented by General Formula 1 of 0.32 or less: Δ YI=YI (340° C.)− YI (285° C.) [General Formula 1] wherein YI (X° C.) denotes a yellow index value measured at a corresponding temperature X ° C. according to ASTM D1925, and a temperature rise time from 285° C. to 340° C. is 20 minutes.
2 . The polycarbonate resin composition according to claim 1 , further comprising one or more additives selected from the group consisting of an antioxidant, a heat stabilizer, a chain extender, a nucleating agent, a flame retardant, a lubricant, an impact modifier, and a fluorescent whitening agent.
3 . The polycarbonate resin composition according to claim 1 , wherein the yellow index value (YI) measured at 20° C. is 5 to 10.
4 . An optical molded article comprising the polycarbonate resin composition of claim 1 .
5 . The optical molded article according to claim 4 , wherein the optical molded article is lens.
6 . An optical molded article comprising the polycarbonate resin composition of claim 3 .
7 . The optical molded article according to claim 6 , wherein the optical molded article is lens.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a National Phase entry pursuant to 35 U.S.C. § 371 of International Application No. PCT/KR2019/010497, filed on Aug. 19, 2019, and claims priority to and the benefit of Korean Patent Application No. 10-2018-0096966 filed on Aug. 20, 2018 with the Korean Intellectual Property Office, the disclosures of which are hereby incorporated by reference in their entirety for all purposes as if fully set forth herein. TECHNICAL FIELD The present invention relates to a polycarbonate resin composition exhibiting excellent heat stability and optical properties, and an optical molded article comprising the same. BACKGROUND Polycarbonate is applied in various fields such as exterior material of electric and electronic products, automobile parts, building material, optical parts, and the like, due to excellent impact strength, numerical stability, heat resistance and transparency, and the like. With recent expansion of the application fields of polycarbonate, there is a need to develop novel polycarbonate maintaining unique properties of polycarbonate but having improved heat stability and optical properties. Particularly, in case applied for optical products, it is important to maintain optical properties of an aimed degree (excellent shield effect or transmittance) without deformation of products even under a high temperature condition, and thus, there is a need to develop technology for simultaneously improving heat stability and optical properties. Thus, there are attempts to copolymerize aromatic diols of different structures to introduce monomers having a different structure into the main chain of polycarbonate, or use additional additives to obtain desired properties. However, most of the technologies have limitations in that the production cost is high, and if chemical resistance or heat resistance is increased, optical properties may be deteriorated to the contrary, and if optical properties are improved, chemical resistance or heat resistance may be deteriorated, and the like. And, there is a need to control the transparency of polycarbonate according to the product group applied, and for example, when applied for optical products (for example, lens), there is a need to lower transmittance in the specific wavelength region according to the purpose of use. Therefore, there is still a need to study and develop novel polycarbonate that not only fulfills aimed optical properties according to the applied products (excellent shield effect or low transmittance of specific wavelength light, and the like) but also has excellent heat resistance. SUMMARY OF THE INVENTION Brief Description Thus, it is an object of the present invention to provide a polycarbonate resin composition exhibiting excellent heat stability and optical properties, more specifically, excellent properties of inhibiting discoloration and controlling transmission of light having a wavelength of 420 nm, and an optical molded article comprising the same. The present invention provides a polycarbonate resin composition comprising polycarbonate resin; and [[4-(dimethylamino)phenyl]methylene] propanedioic acid dimethyl ester as a hindered amine UV absorber that selectively absorbs UVA having a wavelength of 420 nm or less. The present invention also provides an optical molded article comprising the above polycarbonate resin composition. Hereinafter, a polycarbonate resin composition and an optical molded article comprising the same according to specific embodiments of the invention will be explained. First, technical terms in the present specification are only for mentioning specific embodiments, and they are not intended to restrict the present invention. A singular expression includes a plural expression thereof, unless it is expressly stated or obvious from the context that such is not intended. As used herein, the term “comprise” is intended to designate the existence of practiced characteristic, number, step, constructional element or combinations thereof, and it is not intended to preclude the possibility of existence or addition of one or more other characteristics, numbers, steps, constructional elements or combinations thereof. And, as used herein, the terms including ordinal numbers such as “a first” and “a second” are used only to distinguish one constructional element from other constructional elements, and the present invention is not limited to the ordinal numbers. For example, within the scope of the right of the present invention, a first constructional element can be named as a second construction element, and similarly, a second constructional element can be named as a first constructional element. According to one embodiment of the invention, a polycarbonate resin composition is provided, which comprises: polycarbonate resin; and [[4-(dimethylamino)phenyl]methylene] propanedioic acid dimethyl ester as a hindered amine UV absorber that selectively absorbs UVA having a wavelength of 42