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US-12624203-B2 - Thermoplastic resin composition, method of preparing the same, and molded article manufactured using the same

US12624203B2US 12624203 B2US12624203 B2US 12624203B2US-12624203-B2

Abstract

A thermoplastic resin composition including an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) including a polymer seed including 70 to 85% by weight of an alkyl (meth)acrylate and 15 to 30% by weight of an aromatic vinyl compound, a rubber core surrounding the polymer seed and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl (meth)acrylate; and a non-graft copolymer (B) including an alkyl (meth)acrylate, an aromatic vinyl compound, and a vinyl cyanide compound. The present disclosure also relates to a preparation method and a molded article.

Inventors

  • Jangwon PARK
  • Bong Keun Ahn
  • Min Jung Kim
  • Jiyoon JEON
  • Eunji Lee
  • Seyong Kim

Assignees

  • LG CHEM, LTD.

Dates

Publication Date
20260512
Application Date
20220801
Priority Date
20211022

Claims (20)

  1. 1 . A thermoplastic resin composition, comprising: an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) comprising: a polymer seed comprising: 70 to 85% by weight of a first alkyl (meth)acrylate and 15 to 30% by weight of a first aromatic vinyl compound, a rubber core surrounding the polymer seed and comprising: 78 to 90% by weight of a first alkyl acrylate and 10 to 22% by weight of a second aromatic vinyl compound, and a graft shell surrounding the rubber core and comprising: 65 to 80% by weight of a third aromatic vinyl compound, 14 to 25% by weight of a first vinyl cyanide compound, and 3 to 15% by weight of a second alkyl acrylate; and a non-graft copolymer (B) comprising: a second alkyl (meth)acrylate, a fourth aromatic vinyl compound, and a second vinyl cyanide compound, wherein the graft copolymer (A) satisfies both Equations 1 and 2 below: 200 ≤ 2 ⨯ r ⁢ 2 ≤ 300 Equation ⁢ 1 25 ≤ r ⁢ 2 - r ⁢ 1 ≤ 45 , Equation ⁢ 2 wherein r1 represents an average radius (nm) from a center of the graft copolymer to a surface of the polymer seed facing the rubber core, and r2 represents an average radius (nm) from the center of the graft copolymer to a surface of the rubber core facing the graft shell.
  2. 2 . The thermoplastic resin composition according to claim 1 , wherein, in the graft copolymer (A), a difference between a refractive index of the rubber core and a refractive index of the graft shell is 0.08 to 0.09.
  3. 3 . The thermoplastic resin composition according to claim 1 , wherein a difference between a refractive index of the polymer seed of the graft copolymer (A) and a refractive index of the non-graft copolymer (B) is 0.007 or less.
  4. 4 . The thermoplastic resin composition according to claim 1 , wherein, based on 100% by weight in total of the graft copolymer (A), the graft copolymer (A) comprises: 5 to 35% by weight of the polymer seed, 25 to 55% by weight of the rubber core, and 25 to 55% by weight of the graft shell.
  5. 5 . The thermoplastic resin composition according to claim 1 , wherein the non-graft copolymer (B) comprises: 55 to 85% by weight of the second alkyl (meth)acrylate, 10 to 35% by weight of the fourth aromatic vinyl compound, and 1 to 20% by weight of the second vinyl cyanide compound.
  6. 6 . The thermoplastic resin composition according to claim 1 , wherein the thermoplastic resin composition comprises: 10 to 90% by weight of the graft copolymer (A), and 10 to 90% by weight of the non-graft copolymer (B), based on a total weight of the graft copolymer (A) and the non-graft copolymer (B).
  7. 7 . The thermoplastic resin composition according to claim 1 , further comprising an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (C) containing a rubber core having an average particle diameter of 50 to 150 nm.
  8. 8 . The thermoplastic resin composition according to claim 1 , wherein, a difference between a refractive index of a sol of the thermoplastic resin composition and a refractive index of a gel of the thermoplastic resin composition is 0.01 or less, and the refractive indexes are obtained by adding acetone to the thermoplastic resin composition, performing stirring and centrifugation to obtain an insoluble gel and a soluble sol, and then refractive indexes thereof are measured.
  9. 9 . The thermoplastic resin composition according to claim 1 , wherein the thermoplastic resin composition possesses a haze of 5% or less as measured using an injection specimen having a thickness of 3 mm according to ASTM D1003.
  10. 10 . The thermoplastic resin composition according to claim 1 , wherein the thermoplastic resin composition possesses a gloss of 120 or more as measured at 45° using an injection specimen having a thickness of 3 mm according to ASTM D2457.
  11. 11 . The thermoplastic resin composition according to claim 1 , wherein the thermoplastic resin composition possesses an Izod impact strength of 13 kgf·cm/cm or more as measured at room temperature using a specimen having a thickness of ¼″ according to ASTM D256.
  12. 12 . A molded article, comprising the thermoplastic resin composition according to claim 1 .
  13. 13 . The thermoplastic resin composition according to claim 1 , wherein: the first alkyl (meth)acrylate includes methyl methacrylate, and the first aromatic vinyl compound includes styrene.
  14. 14 . The thermoplastic resin composition according to claim 1 , wherein: the first alkyl acrylate includes butyl acrylate, and the second aromatic vinyl compound includes styrene.
  15. 15 . The thermoplastic resin composition according to claim 1 , wherein: the third aromatic vinyl compound includes styrene, the first vinyl cyanide compound includes acrylonitrile, and the second alkyl acrylate includes butyl acrylate.
  16. 16 . The thermoplastic resin composition according to claim 1 , wherein: the second alkyl (meth)acrylate includes methyl methacrylate, the fourth aromatic vinyl compound includes styrene, and the second vinyl cyanide compound includes acrylonitrile.
  17. 17 . The thermoplastic resin composition according to claim 1 , wherein: in the graft copolymer (A), a difference between a refractive index of the rubber core and a refractive index of the graft shell is 0.08 to 0.09, a difference between a refractive index of the polymer seed of the graft copolymer (A) and a refractive index of the non-graft copolymer (B) is 0.007 or less, the non-graft copolymer (B) comprises: 55 to 85% by weight of the second alkyl (meth)acrylate, 10 to 35% by weight of the fourth aromatic vinyl compound, and 1 to 20% by weight of the second vinyl cyanide compound, and a difference between a refractive index of a sol of the thermoplastic resin composition and a refractive index of a gel of the thermoplastic resin composition is 0.01 or less, and the refractive indexes are obtained by adding acetone to the thermoplastic resin composition, performing stirring and centrifugation to obtain an insoluble gel and a soluble sol, and then refractive indexes thereof are measured.
  18. 18 . The thermoplastic resin composition according to claim 17 , wherein: the first alkyl (meth)acrylate includes methyl methacrylate, the first aromatic vinyl compound includes styrene, the first alkyl acrylate includes butyl acrylate, the second aromatic vinyl compound includes styrene, the third aromatic vinyl compound includes styrene, the first vinyl cyanide compound includes acrylonitrile, the second alkyl acrylate includes butyl acrylate, the second alkyl (meth)acrylate includes methyl methacrylate, the fourth aromatic vinyl compound includes styrene, and the second vinyl cyanide compound includes acrylonitrile.
  19. 19 . A method of preparing a thermoplastic resin composition, comprising kneading and extruding, at 180 to 300° C. and 80 to 400 rpm: an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) comprising: a polymer seed comprising: 70 to 85% by weight of a first alkyl (meth)acrylate and 15 to 30% by weight of a first aromatic vinyl compound, a rubber core surrounding the polymer seed and comprising: 78 to 90% by weight of a first alkyl acrylate and 10 to 22% by weight of a second aromatic vinyl compound, and a graft shell surrounding the rubber core and comprising: 65 to 80% by weight of a third aromatic vinyl compound, 14 to 25% by weight of a first vinyl cyanide compound, and 3 to 15% by weight of a second alkyl acrylate; and a non-graft copolymer (B) comprising: a second alkyl (meth)acrylate, a fourth aromatic vinyl compound, and a second vinyl cyanide compound, wherein the graft copolymer (A) satisfies both Equations 1 and 2 below: 200 ≤ 2 ⨯ r ⁢ 2 ≤ 300 Equation ⁢ 1 25 ≤ r ⁢ 2 - r ⁢ 1 ≤ 45 , Equation ⁢ 2 wherein: r1 represents an average radius (nm) from a center of the graft copolymer to a surface of the polymer seed facing the rubber core, and r2 represents an average radius (nm) from the center of the graft copolymer to a surface of the rubber core facing the graft shell.
  20. 20 . The method according to claim 19 , wherein the kneading and extruding includes kneading and extruding an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (C) containing a rubber core having an average particle diameter of 50 to 150 nm, the graft copolymer (A), and the non-graft copolymer (B).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Korean Patent Application No. 10-2021-0141871, filed on Oct. 22, 2021, and Korean Patent Application No. 10-2022-0093137, re-filed on Jul. 27, 2022, based on the priority of the above patent, in the Korean Intellectual Property Office, the disclosures of each of which are incorporated herein by reference. TECHNICAL FIELD The present invention relates to a thermoplastic resin composition, a method of preparing the same, and a molded article manufactured using the same. More particularly, the present invention relates to a thermoplastic resin composition having excellent transparency, gloss, weather resistance, and impact resistance prepared by adjusting the composition and composition ratio of each layer of a graft copolymer having a structure consisting of a polymer seed, a rubber core surrounding the seed, and a graft shell surrounding the core, adjusting the morphology of the rubber core, and adjusting the refractive index difference with a matrix polymer; a method of preparing the thermoplastic resin composition; and a molded article manufactured using the thermoplastic resin composition. BACKGROUND ART Acrylate-styrene-acrylonitrile graft copolymers (hereinafter referred to as “ASA resins”) do not contain an unstable double bond, and thus have very excellent weather resistance. Accordingly, ASA resins are widely used in various fields such as electric/electronic parts, building materials (e.g., vinyl siding, etc.), extrusion profiles, and automobile parts. In recent years, in the field of outdoor products, market demand for high value-added products having properties such as unpainted, transparent, high chroma, and special color is continuously increasing. To impart transparency to a graft copolymer including a rubber core, the refractive indexes of the rubber core, a graft shell, and a matrix resin should be similar to each other. In addition, in a resin composition including a graft copolymer and a matrix resin, when the difference in refractive index between a rubber core and the matrix resin is small, refraction and reflection of light do not occur at the interface of the graft copolymer, so that the resin composition becomes transparent. In the case of an ASA resin including a butyl acrylate rubber core and a styrene-acrylonitrile copolymer shell, the refractive index of the butyl acrylate rubber is 1.46, and the refractive index of the styrene-acrylonitrile copolymer is 1.56 to 1.58. Due to the large difference in refractive index between the core and the shell, the resin is opaque. In addition, when an ASA resin is prepared using a styrene-acrylonitrile copolymer (hereinafter referred to as “SAN resin”) as a matrix resin, due to the large difference in refractive index between the SAN resin (refractive index: 1.56 to 1.58) and the core of the ASA resin, the resin composition is opaque. Therefore, it is necessary to develop a resin composition having excellent gloss, weather resistance, and mechanical properties while realizing transparency by reducing the difference between the refractive index of each of a seed, a core, and a shell constituting an ASA resin and the refractive index of a matrix resin. RELATED ART DOCUMENTS Patent Documents KR 2006-0118156 A DISCLOSURE Technical Problem Therefore, the present invention has been made in view of the above problems, and it is one object of the present invention to provide a thermoplastic resin composition having excellent transparency, gloss, weather resistance, and impact resistance, a method of preparing the same, and a molded article manufactured using the same. The above and other objects can be accomplished by the present invention described below. Technical Solution In accordance with one aspect of the present invention, provided is a thermoplastic resin composition including an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) including a polymer seed including 70 to 85% by weight of an alkyl (meth)acrylate and 15 to 30% by weight of an aromatic vinyl compound, a rubber core surrounding the polymer seed and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl (meth)acrylate; and a non-graft copolymer (B) including an alkyl (meth)acrylate, an aromatic vinyl compound, and a vinyl cyanide compound, wherein the graft copolymer (A) satisfies both Equations 1 and 2 below: 200≤2⋆r⁢2≤300[Equation⁢ 1]25≤r⁢2-r⁢1≤45,[Equation⁢ 2]wherein r1 represents an average radius (nm) from a center of the graft copolymer to the polymer seed, and r2 represents an average radius (nm) from the center of the graft copolymer to the rubber core. In the graft copolymer (A), a difference between a refractive index