(19)
(11)EP 3 187 542 A1

(12)EUROPEAN PATENT APPLICATION

(43)Date of publication:
05.07.2017 Bulletin 2017/27

(21)Application number: 16207036.1

(22)Date of filing:  28.12.2016
(51)International Patent Classification (IPC): 
C08L 69/00(2006.01)
(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME
Designated Validation States:
MA MD

(30)Priority: 31.12.2015 KR 20150191436

(71)Applicant: Lotte Advanced Materials Co., Ltd.
Jeollanam-do 59616 (KR)

(72)Inventors:
  • CHOI, Ki Hong
    Uiwang-si, Gyeonggi-do (KR)
  • SHIN, Seung Shik
    Uiwang-si, Gyeonggi-do (KR)
  • LEE, Hyun Ho
    Uiwang-si, Gyeonggi-do (KR)
  • CHIN, Kyuong Sik
    Uiwang-si, Gyeonggi-do (KR)
  • CHOI, Sung Hun
    Uiwang-si, Gyeonggi-do (KR)
  • HA, Dong In
    Uiwang-si, Gyeonggi-do (KR)

(74)Representative: Michalski Hüttermann & Partner Patentanwälte mbB 
Speditionstraße 21
40221 Düsseldorf
40221 Düsseldorf (DE)

  


(54)THERMOPLASTIC RESIN COMPOSITION AND ARTICLE PRODUCED THEREFORM


(57) Disclosed herein are a thermoplastic resin composition and a molded article produced from the thermoplastic resin composition. The thermoplastic resin composition includes: a polycarbonate resin; a rubber-modified vinyl graft copolymer; inorganic fillers comprising talc and wollastonite; maleic anhydride-modified olefin wax; and a phosphorus compound represented by Formula 1, wherein a weight ratio of the talc to the wollastonite ranges from 1:0.1 to 1:0.9, and a weight ratio of the talc to the phosphorus compound ranges from 1:0.005 to 1:0.05,

wherein R1 and R2 are each independently a hydrogen atom or a C1 to C10 alkyl group and R3 is a C10 to C30 alkyl group.
The thermoplastic resin composition has excellent properties in terms of impact resistance, stiffness, dimensional stability, appearance, and balance therebetween.


Description

Field of the Invention



[0001] The present invention relates to a thermoplastic resin composition and a molded article produced from the same. More particularly, the present invention relates to a thermoplastic resin composition which has excellent properties in terms of impact resistance, stiffness, dimensional stability, appearance, and balance therebetween, and a molded article produced from the same.

Description of the Related Art



[0002] Polycarbonate resins are engineering plastics with excellent impact resistance, heat resistance, dimensional stability, weatherability, chemical resistance, electrical properties, transparency, and the like, and thus have been applied to various fields such as office automation, electrical/electronic products, and automotive parts.

[0003] In addition, a polycarbonate resin may be used in the form of a thermoplastic resin composition including additives such as reinforcing fillers, impact modifiers, and antioxidants to further improve stiffness and impact resistance and to reduce production costs, depending on application.

[0004] However, when reinforcing fillers such as glass fiber are blended with a polycarbonate resin, fluidity (moldability) and impact resistance of the resin composition can deteriorate, and the reinforcing fillers can protrude from a surface of a molded article, causing deterioration in appearance characteristics. In addition, when flake-type talc is used as a reinforcing filler, there is a limit to improvement in dimensional stability and mechanical properties of the resin composition, such as impact resistance, can deteriorate due to brittleness of the talc, although appearance characteristics of the resin composition can be improved.

[0005] Therefore, there is a need for a polycarbonate-based thermoplastic resin composition which can provide excellent properties in terms of impact resistance, stiffness, dimensional stability, appearance, and balance therebetween.

[0006] One example of the related art is disclosed in Korean Patent Publication No. 2011-0059886.

Summary of the Invention



[0007] It is an aspect of the present invention to provide a thermoplastic resin composition which can have excellent properties in terms of impact resistance, stiffness, dimensional stability, appearance, and balance therebetween, and a molded article produced from the same.

[0008] One aspect of the present invention relates to a thermoplastic resin composition. The thermoplastic resin composition includes: a polycarbonate resin; a rubber-modified vinyl graft copolymer; inorganic fillers comprising talc and wollastonite; a maleic anhydride-modified olefin wax; and a phosphorus compound represented by Formula 1, wherein a weight ratio of the talc to the wollastonite ranges from 1:0.1 to 1:0.9, and a weight ratio of the talc to the phosphorus compound ranges from 1:0.005 to 1:0.05,

wherein R1 and R2 are each independently a hydrogen atom or a C1 to C10 alkyl group and R3 is a C10 to C30 alkyl group.

[0009] In exemplary embodiments, the thermoplastic resin composition may include 100 parts by weight of the polycarbonate resin, 5 parts by weight to 20 parts by weight of the rubber-modified vinyl graft copolymer, 10 parts by weight to 40 parts by weight of the inorganic fillers, 0.1 parts by weight to 5 parts by weight of the maleic anhydride-modified olefin wax, and 0.1 parts by weight to 5 parts by weight of the phosphorus compound.

[0010] In exemplary embodiments, the rubber-modified vinyl graft copolymer may be prepared by grafting an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer to a rubbery polymer.

[0011] In exemplary embodiments, the maleic anhydride-modified olefin wax may be a polymer of 80 wt% to 99 wt% of olefin and 1 wt% to 20 wt% of maleic anhydride.

[0012] In exemplary embodiments, the maleic anhydride-modified olefin wax may have a weight average molecular weight of 5,000 g/mol to 100,000 g/mol.

[0013] In exemplary embodiments, the thermoplastic resin composition may further include at least one additive selected from among flame retardants, UV stabilizers, fluorescent whitening agents, release agents, nucleating agents, lubricants, antistatic agents, stabilizers, reinforcing agents, pigments, and dyes.

[0014] In exemplary embodiments, the thermoplastic resin composition may have a notched Izod impact strength of 4.5 kgf·cm/cm or more, as measured on a 1/8" thick Izod specimen in accordance with ASTM D256.

[0015] In exemplary embodiments, the thermoplastic resin composition may have a welded Izod impact strength of 3.5 kgf·cm/cm or more, as measured on a 1/8" thick Izod specimen having a weld line at a center thereof in accordance with ASTM D256.

[0016] In exemplary embodiments, the thermoplastic resin composition may have a coefficient of linear expansion of 30 µm/°C to 60 µm/°C, as measured on a 6.4 mm bent specimen at a temperature of 10°C to 90°C in accordance with ASTM D696.

[0017] In exemplary embodiments, the thermoplastic resin composition may have a degree of warpage of 5 mm to 17 mm, as obtained by measuring a distance (height) from the ground to one comer of an injection molded specimen having a size of 15 cm×40 cm×15 mm, with other three corners of the specimen attached to the ground, after leaving the specimen at 23°C and 50% RH for 24 hours.

[0018] Another aspect of the present invention relates to a molded article produced from the thermoplastic resin composition as set forth above.

Detailed Description of the Invention



[0019] Hereinafter, embodiments of the present invention will be described in detail.

[0020] A thermoplastic resin composition according to the present invention includes: (A) a polycarbonate resin; (B) a rubber-modified vinyl graft copolymer; (C) inorganic fillers including talc and wollastonite; (D) maleic anhydride-modified olefin wax; and (E) a phosphorus compound.

(A) Polycarbonate resin



[0021] The polycarbonate resin is a typical thermoplastic polycarbonate resin. For example, the polycarbonate resin may be an aromatic polycarbonate resin prepared by reacting an aromatic diol compound (diphenols) with a carbonate precursor, such as phosgene, halogen formate, or carbonate diester.

[0022] Examples of the aromatic diol compound may include 4,4'-biphenol, 2,2-bis-(4-hydroxyphenyl)-propane, 2,4-bis-(4-hydroxyphenyl)-2-methylbutane, 1,1-bis-(4-hydroxyphenyl)-cyclohexane, 2,2-bis-(3-chloro-4-hydroxyphenyl)-propane, and 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane, without being limited thereto. For example, the aromatic diol compound may be 2,2-bis-(4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane, or 1,1-bis-(4-hydroxyphenyl)-cyclohexane, specifically 2,2-bis-(4-hydroxyphenyl)-propane, which is also referred to as bisphenol A.

[0023] In some embodiments, the polycarbonate resin may be a branched polycarbonate resin. For example, the polycarbonate resin may be prepared by adding a tri- or more polyfunctional compound, for example, a tri- or more valent phenol group-containing compound in an amount of 0.05 mol% to 2 mol% based on the total number of moles of the aromatic diol compound used in polymerization.

[0024] In some embodiments, the polycarbonate resin may be a homopolycarbonate resin, a copolycarbonate resin, or a blend thereof. In addition, the polycarbonate resin may be partly or completely replaced by an aromatic polyester-carbonate resin obtained by polymerization in the presence of an ester precursor, for example, a bifunctional carboxylic acid.

[0025] In some embodiments, the polycarbonate resin the polycarbonate resin may have a weight average molecular weight (Mw) of 10,000 g/mol to 200,000 g/mol, for example, 15,000 g/mol to 40,000 g/mol, as measured by gel permeation chromatography (GPC). Within this range, the thermoplastic resin composition can have excellent properties in terms of impact resistance, scratch resistance, and heat resistance.

(B) Rubber-modified vinyl graft copolymer



[0026] The rubber-modified vinyl graft copolymer serves to improve impact resistance and fluidity of the thermoplastic resin composition and may be prepared by grafting an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer to a rubbery polymer.

[0027] Examples of the rubbery polymer may include: diene rubbers such as polybutadiene, poly(styrene-butadiene), poly(acrylonitrile-butadiene); acrylic rubbers such as saturated rubbers obtained by adding hydrogen to the diene rubbers, isoprene rubbers, and poly(butyl acrylate); and ethylene-propylene-diene monomer terpolymers (EPDM), without being limited thereto. For example, the rubbery polymer may be a diene rubber, specifically a butadiene rubber. The rubbery polymer (rubber particles) may have an average (z-average) particle size of 0.05 µm to 6 µm, for example, 0.15 µm to 4 µm, specifically 0.25 µm to 3.5 µm. Within this range, the thermoplastic resin composition can have excellent properties in terms of impact resistance and appearance. The rubbery polymer may be present in an amount of 5 wt% to 65 wt%, for example, 10 wt% to 60 wt%, specifically 20 wt% to 50 wt% based on the total weight of the rubber-modified vinyl graft copolymer. In some embodiments, the rubber-modified vinyl graft copolymer can include the rubbery polymer in an amount of about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 5051, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, or 65 wt%. Further, according to some embodiments, the amount of the rubbery polymer can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent properties in terms of impact resistance, stiffness, and the like.

[0028] The aromatic vinyl monomer is graft-copolymerizable with the rubbery copolymer and may include, for example, styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, p-t-butylstyrene, ethylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, and vinyl naphthalene, without being limited thereto. For example, the aromatic vinyl monomer may be styrene. The aromatic vinyl monomer may be present in an amount of 15 wt% to 94 wt%, for example, 20 wt% to 80 wt%, specifically 30 wt% to 60 wt% based on the total weight of the rubber-modified vinyl graft copolymer. In some embodiments, the rubber-modified vinyl graft copolymer can include the aromatic vinyl monomer in an amount of about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, or 94 wt%. Further, according to some embodiments, the amount of the aromatic vinyl monomer can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent properties in terms of impact resistance, stiffness, and the like.

[0029] Examples of the monomer copolymerizable with the aromatic vinyl monomer may include: vinyl cyanide compounds, such as acrylonitrile, methacrylonitrile, or ethacrylonitrile; and monomers for providing processability and heat resistance such as acrylic acid, methacrylic acid, maleic anhydride, or N-substituted maleimide, without being limited thereto. These monomers may be used alone or as a mixture thereof. The monomer copolymerizable with the aromatic vinyl monomer may be present in an amount of 1 wt% to 50 wt%, for example, 5 wt% to 45 wt%, specifically 10 wt% to 30 wt%, based on the total weight of the rubber-modified vinyl graft copolymer. In some embodiments, the rubber-modified vinyl graft copolymer can include the monomer copolymerizable with the aromatic vinyl monomer in an amount of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 wt%. Further, according to some embodiments, the amount of the monomer copolymerizable with the aromatic vinyl monomer can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent properties in terms of impact resistance, heat resistance, processability, and the like.

[0030] Examples of the rubber-modified vinyl graft copolymer may include an acrylonitrile-butadiene-styrene graft copolymer (g-ABS), acrylonitrile-ethylene/propylene rubber-styrene graft copolymer (g-AES), and an acrylic rubber-styrene-acrylonitrile graft copolymer (g-ASA), without being limited thereto.

[0031] In some embodiments, the rubber-modified vinyl graft copolymer may be present in an amount of 5 parts by weight to 20 parts by weight, for example, 8 parts by weight to 15 parts by weight, based on 100 parts by weight of the polycarbonate resin. In some embodiments, the thermoplastic resin composition can include the rubber-modified vinyl graft copolymer in an amount of about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts by weight. Further, according to some embodiments, the amount of the rubber-modified vinyl graft copolymer can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent properties in terms of impact resistance, stiffness, appearance, and balance therebetween.

(C) Inorganic fillers



[0032] The inorganic fillers serve to improve impact resistance, stiffness and dimensional stability of the thermoplastic resin composition and include talc and wollastonite.

[0033] In some embodiments, flake-like talc may be used as the talc. The talc may have an average particle size of 2 µm to 7 µm, for example, 3 µm to 5 µm. Within this range, the thermoplastic resin composition can have excellent properties in terms of stiffness and dimensional stability.

[0034] In some embodiments, the wollastonite is a calcium-based mineral that is white and has a needle-like shape. The wollastonite may have an average particle size of 1 µm to 60 µm, for example, 3 µm to 40 µm and an average aspect ratio of 6 or greater, for example, 7 to 20. As used herein, the average aspect ratio refers to a ratio of the average length (long length) (a) of the wollastonite to the average diameter (b) of the wollastonite (a/b). Within this range, the thermoplastic resin composition can have excellent properties in terms of stiffness, impact resistance, and dimensional stability.

[0035] In some embodiments, a weight ratio of the talc to the wollastonite (talc:wollastonite) may range from 1:0.1 to 1:0.9, for example, 1:0.3 to 1:0.7. In exemplary embodiments, a weight ratio of the talc to the wollastonite (talc:wollastonite) may be about 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, or 1:0.9. If the weight ratio of the talc to the wollastonite is less than 1:0.1, impact resistance of the thermoplastic resin composition is likely to deteriorate, whereas, if the weight ratio of the talc to the wollastonite exceeds 1:0.9, stiffness (warpage properties) of the thermoplastic resin composition is likely to deteriorate.

[0036] In some embodiments, the inorganic fillers may be present in an amount of 10 parts by weight to 40 parts by weight, for example, 15 parts by weight to 35 parts by weight, based on 100 parts by weight of the polycarbonate resin. In some embodiments, the thermoplastic resin composition can include the inorganic fillers in an amount of about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 parts by weight. Further, according to some embodiments, the amount of the inorganic fillers can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent properties in terms of impact resistance, stiffness, dimensional stability, appearance, and balance therebetween.

(D) Maleic anhydride-modified olefin wax



[0037] The maleic anhydride-modified olefin wax serves to improve bonding strength between the polycarbonate resin and the inorganic fillers and impact resistance of the thermoplastic resin composition and may include a polymer of olefin and maleic anhydride.

[0038] In some embodiments, the olefin may be C10 to C500 α-olefin and may be present in an amount of 80 wt% to 99 wt%, for example, 90 wt% to 99 wt%, based on the total weight of the olefin wax. In some embodiments, the olefin wax can include the olefin in an amount of about 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99 wt%. Further, according to some embodiments, the amount of the olefin can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent impact resistance.

[0039] In some embodiments, the maleic anhydride may be present in an amount of 1 wt% to 20 wt%, for example, 1 wt% to 10 wt%, based on the total weight of the olefin wax. In some embodiments, the olefin wax can include the maleic anhydride in an amount of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 wt%. Further, according to some embodiments, the amount of the maleic anhydride can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent impact resistance.

[0040] In some embodiments, the maleic anhydride-modified olefin wax may have a weight average molecular weight (Mw) of 5,000 g/mol to 100,000 g/mol, for example, 10,000 g/mol to 50,000 g/mol, as measured by gel permeation chromatography (GPC). Within this range, bonding strength between the polycarbonate resin and the inorganic fillers can be improved, and the thermoplastic resin composition can have excellent impact resistance.

[0041] In some embodiments, the maleic anhydride-modified olefin wax may be present in an amount of 0.1 parts by weight to 5 parts by weight, for example, 0.3 parts by weight to 1 part by weight, based on 100 parts by weight of the polycarbonate resin. In some embodiments, the thermoplastic resin composition can include the maleic anhydride-modified olefin wax in an amount of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, or 5 parts by weight. Further, according to some embodiments, the amount of the maleic anhydride-modified olefin wax can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent impact resistance.

(E) Phosphorus compound



[0042] The phosphorus compound serves to chelate metal ions from the talc and adjust pH of the thermoplastic resin composition to 5.0 to 8.0, thereby reducing decomposition of the polycarbonate resin when the thermoplastic resin composition is processed. The phosphorus compound may be represented by Formula 1,



wherein R1 and R2 are each independently a hydrogen atom or a C1 to C10 alkyl group and R3 is a C10 to C30 alkyl group.

[0043] Examples of the phosphorus compound may include octadecyl dihydrogen phosphate and stearyl dihydrogen phosphate, without being limited thereto.

[0044] In some embodiments, the weight ratio of the talc to the phosphorus compound (talc:phosphorus compound) may range from 1:0.005 to 1: 0.05, for example, 1:0.007 to 1:0.03. In exemplary embodiments, a weight ratio of the talc to the phosphorus compound (talc:phosphorus compound) may be about 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, 1:0.01, 1:0.02, 1:0.03, 1:0.04, or 1:0.05. If the weight ratio of the talc to the phosphorus compound is less than 1:0.005, impact resistance of the thermoplastic resin composition is likely to deteriorate due to decomposition of the polycarbonate resin when the thermoplastic resin composition is processed, whereas, if the weight ratio of the talc to the phosphorus compound exceeds 1:0.05, appearance characteristics of the thermoplastic resin composition are likely to deteriorate.

[0045] In some embodiments, the phosphorus compound may be present in an amount of 0.1 parts by weight to 5 parts by weight, for example, 0.2 parts by weight to 1.0 part by weight, based on 100 parts by weight of the polycarbonate resin. In some embodiments, the thermoplastic resin composition can include the phosphorus compound in an amount of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, or 5 parts by weight. Further, according to some embodiments, the amount of the phosphorus compound can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts. Within this range, the thermoplastic resin composition can have excellent properties in terms of impact resistance and appearance.

[0046] The thermoplastic resin composition according to one embodiment of the invention may further include typical additives, as needed. Examples of the additives may include flame retardants, antioxidants, drip inhibitors, lubricants, release agents, nucleating agents, antistatic agents, stabilizers, pigments, dyes, and mixtures thereof, without being limited thereto. When the additives are used, the additives may be present in an amount of 0.001 parts by weight to 20 parts by weight based on 100 parts by weight of the base resin, without being limited thereto. In some embodiments, the thermoplastic resin composition can include the additive(s) in an amount of about 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts by weight. Further, according to some embodiments, the amount of the additive(s) can be in a range from about any of the foregoing amounts to about any other of the foregoing amounts.

[0047] Examples of the flame retardants may include phosphorus flame retardants such as aromatic phosphoric ester compounds, without being limited thereto. For example, the flame retardants may include aromatic phosphoric ester compounds such as diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tri(2,6-dimethylphenyl)phosphate, tri(2,4,6-trimethylphenyl)phosphate, tri(2,4-ditertiarybutylphenyl)phosphate, tri(2,6-dimethylphenyl)phosphate, bisphenol-A bis(diphenylphosphate), resorcinol bis(diphenylphosphate), and resorcinol bis(2,4-ditertiarybutylphenylphosphate).

[0048] The thermoplastic resin composition according to the embodiment of the invention may have a notched Izod impact strength of 4.5 kgf·cm/cm or more, for example, 5kgf·cm/cm to 10 kgf·cm/cm, as measured on a 1/8" thick Izod specimen in accordance with ASTM D256 and a welded Izod impact strength of 3.5 kgf·cm/cm or more, for example, 3.5 kgf·cm/cm to 6 kgf·cm/cm, as measured on a 1/8" thick Izod specimen having a weld line at the center thereof in accordance with ASTM D256.

[0049] In some embodiments, the thermoplastic resin composition may have a coefficient of linear expansion of 30 µm/°C to 60 µm/°C, for example, 40 µm/°C to 50 µm/°C, as measured on a 6.4 mm bent specimen at a temperature of 10°C to 90°C in accordance with ASTM D696.

[0050] In some embodiments, the thermoplastic resin composition may have a degree of warpage of 5 mm to 17 mm, for example, 10 mm to 15 mm, as obtained by measuring a distance (height) from the ground to one corner of an injection molded specimen having a size of 15 cm×40 cm×15 mm, with other three corners of the specimen attached to the ground, after leaving the specimen at 23°C and 50% RH for 24 hours.

[0051] In accordance with another aspect of the present invention, a molded article is produced from the thermoplastic resin composition as set forth above. The thermoplastic resin composition according to the present invention may be prepared by a method of preparing a thermoplastic resin composition known in the art. For example, the above components and, optionally, other additives are mixed, followed by melt extrusion in an extruder, thereby preparing a resin composition in pellet form. The prepared pellets may be produced into various molded articles (products) through various molding methods, such as injection molding, extrusion, vacuum molding, and casting. Such molding methods are well known to those skilled in the art. Since the molded article exhibits excellent properties in terms of impact resistance, stiffness, dimensional stability, appearance, and balance therebetween, the molded article is useful as an interior/exterior material for automobile parts or electrical/electronic products.

[0052] 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 construed in any way as limiting the present invention.

EXAMPLE



[0053] Details of components used in the following Examples and Comparative Examples are as follows:

(A) Polycarbonate resin
A bisphenol-A polycarbonate resin (weight average molecular weight: 25,000 g/mol)

(B) Rubber-modified vinyl graft copolymer
A g-ABS resin prepared by grafting 52 wt% of styrene and acrylonitrile (weight ratio (SM/AN): 73/27) to 48 wt% of polybutadiene rubber (PBR, average particle diameter (Z-average): 310 nm).

(C) Inorganic fillers

(C1) Talc (KCM-6300C, Haicheng Xinda Mining Industry Co., Ltd.)

(C2) Wollastonite (4W, NYCO Minerals)

(C3) Glass fiber (CS321 EC10-3, KCC Co., Ltd.)

(D) Maleic anhydride-modified olefin wax
A copolymer of α-olefin and maleic anhydride (DIACARNA™, Mitsubishi Chemical Corporation)

(E) Phosphorus compound
Octadecyl dihydrogen phosphate


Examples 1 to 3 and Comparative Examples 1 to 3: Preparation of thermoplastic resin composition



[0054] The above components were placed in a 44 L/D twin-screw extruder having a diameter of 45 mm in amounts as listed in Table 1, followed by melt extrusion at an extrusion temperature of 250°C and a stirring speed of 250 rpm, thereby preparing a thermoplastic resin composition in pellet form. The prepared pellets were dried at 90°C for 3 hours or more, followed by injection molding using a screw-type injection machine (150 ton single injection machine) at 240°C to 280°C, thereby preparing a specimen for property evaluation. The prepared specimen was evaluated as the following properties, and results are shown in Table 1.

Property evaluation



[0055] (1) Notched Izod impact strength (unit: kgf·cm/cm): Notched Izod impact strength was measured on a 1/8" thick notched Izod specimen in accordance with ASTM D256.
(2) Welded Izod impact strength (unit: kgf·cm/cm): Welded Izod impact strength was measured on a 1/8" thick Izod specimen having a weld line at a center thereof in accordance with ASTM D256.
(3) Coefficient of linear expansion (CTE, unit: µm/°C): Coefficient of linear expansion was measured on a 6.4 mm bent specimen at 10°C to 90°C in accordance with ASTM D696.
(4) Warpage (unit: mm): Warpage was evaluated by measuring a distance (height) from the ground to one corner of an injection molded specimen having a size of 15 cm×40 cm×15 mm, with other three corners of the specimen attached to the ground, after leaving the specimen at 23°C and 50% RH for 24 hours.
Table 1
 ExampleComparative Example
123123456
(A) (parts by weight) 100 100 100 100 100 100 100 100 100
(B) (parts by weight) 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5 9.5
(C) (parts by weight) (C1) 21.6 24.9 19.1 21.6 30.9 16.2 21.6 21.6 21.6
(C2) 10.8 7.5 13.3 - 1.5 16.2 10.8 10.8 10.8
(C3) - - - 10.8 - - - - -
(D) (parts by weight) 0.41 0.41 0.41 0.41 0.41 0.41 0.41 0.41 -
(E) (parts by weight) 0.41 0.5 0.38 0.41 0.41 0.41 0.09 1.3 0.41
Notched Izod impact strength 5.4 5.1 5.8 6.0 4.1 4.5 4.0 4.1 3.9
Welded Izod impact strength 3.8 3.5 4.0 4.5 3.0 3.3 2.9 3.2 3.0
Coefficient of linear expansion 43 46 41 35 57 40 44 42 40
Warpage 14.7 12.1 15.0 25.1 10.7 17.1 14.8 15.0 13.9


[0056] From the above results, it can be seen that the thermoplastic resin compositions according to the present invention had excellent properties in terms of impact resistance (notched Izod impact strength, welded Izod impact strength), stiffness (warpage properties), and dimensional stability (coefficient of linear expansion).

[0057] Conversely, the thermoplastic resin composition of Comparative Example 1 not using wollastonite suffered from severe deformation in warpage evaluation and thus exhibited poor stiffness; the thermoplastic resin compositions of Comparative Examples 2 and 3 in which the weight ratio of talc to wollastonite did not fall within the range of the present invention exhibited poor properties in terms of impact resistance and stiffness; the thermoplastic resin compositions of Comparative Examples 2 and 3 in which the weight ratio of talc to a phosphorus compound did not fall within the range of the present invention exhibited poor impact resistance; and the thermoplastic resin composition of Comparative Example 6 not using wax exhibited poor impact resistance.

[0058] 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 present invention.


Claims

1. A thermoplastic resin composition, comprising:

a polycarbonate resin;

a rubber-modified vinyl graft copolymer;

inorganic fillers comprising talc and wollastonite;

a maleic anhydride-modified olefin wax; and

a phosphorus compound represented by Formula 1,

wherein a weight ratio of the talc to the wollastonite ranges from 1:0.1 to 1:0.9, and a weight ratio of the talc to the phosphorus compound ranges from 1:0.005 to 1:0.05,

wherein R1 and R2 are each independently a hydrogen atom or a C1 to C10 alkyl group and R3 is a C10 to C30 alkyl group.
 
2. The thermoplastic resin composition according to claim 1, comprising: 100 parts by weight of the polycarbonate resin, 5 parts by weight to 20 parts by weight of the rubber-modified vinyl graft copolymer, 10 parts by weight to 40 parts by weight of the inorganic fillers, 0.1 parts by weight to 5 parts by weight of the maleic anhydride-modified olefin wax, and 0.1 parts by weight to 5 parts by weight of the phosphorus compound.
 
3. The thermoplastic resin composition according to claim 1 or 2, wherein the rubber-modified vinyl graft copolymer is prepared by grafting an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer to a rubbery polymer.
 
4. The thermoplastic resin composition according to claims 1 to 3, wherein the maleic anhydride-modified olefin wax is a polymer of 80 wt% to 99 wt% of olefin and 1 wt% to 20 wt% of maleic anhydride.
 
5. The thermoplastic resin composition according to claims 1 to 4, wherein the maleic anhydride-modified olefin wax has a weight average molecular weight of 5,000 g/mol to 100,000 g/mol.
 
6. The thermoplastic resin composition according to claims 1 to 5, further comprising at least one additive selected from among flame retardants, UV stabilizers, fluorescent whitening agents, release agents, nucleating agents, lubricants, antistatic agents, stabilizers, reinforcing agents, pigments, and dyes.
 
7. The thermoplastic resin composition according to claims 1 to 6, wherein the thermoplastic resin composition has a notched Izod impact strength of 4.5 kgf·cm/cm or more, as measured on a 1/8" thick Izod specimen in accordance with ASTM D256.
 
8. The thermoplastic resin composition according to claims 1 to 7, wherein the thermoplastic resin composition has a welded Izod impact strength of 3.5 kgf·cm/cm or more, as measured on a 1/8" thick Izod specimen having a weld line at a center thereof in accordance with ASTM D256.
 
9. The thermoplastic resin composition according to claims 1 to 8, wherein the thermoplastic resin composition has a coefficient of linear expansion of 30 µm/°C to 60 µm/°C, as measured on a 6.4 mm bent specimen at a temperature of 10°C to 90°C in accordance with ASTM D696.
 
10. The thermoplastic resin composition according to claims 1 to 9, wherein the thermoplastic resin composition has a degree of warpage of 5 mm to 17 mm, as obtained by measuring a distance (height) from the ground to one corner of an injection molded specimen having a size of 15 cm×40 cm×15 mm, with other three corners of the specimen attached to the ground, after leaving the specimen at 23°C and 50% RH for 24 hours.
 
11. A molded article produced from the thermoplastic resin composition according to any one of claims 1 to 10.
 





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Cited references

REFERENCES CITED IN THE DESCRIPTION



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Patent documents cited in the description