Polycarbonate resin composition having excellent mechanical properties and improved optical properties, and molded article containing the same

Abstract

The present invention relates to a polycarbonate resin composition and a molded article containing the same. More specifically, the present invention relates to a polycarbonate resin composition that contains polycarbonate as a base resin and a polyalkylene glycol adduct of an anhydrosugar alcohol, which is a biomass-derived substance, as a plasticizer component, and that exhibits improved optical properties while retaining excellent mechanical properties such as tensile strength, processability, and heat resistance, and a molded article containing the same.

Description

[Technical Field]

[0001] The present invention relates to a polycarbonate resin composition and a molded article containing the same. More specifically, the present invention relates to a polycarbonate resin composition that contains polycarbonate as a base resin and a polyalkylene glycol adduct of an anhydrosugar alcohol, which is a biomass-derived substance, and a polyalkylene glycol as plasticizer components, and that exhibits improved optical properties while retaining excellent mechanical properties such as tensile strength, processability, and heat resistance, and a molded article containing the same. [Background technology]

[0002] In order to produce light guides used in automobile headlamps, lighting components and housings of various electronic devices with a uniform thickness, resins with a high melt index are required, and they must also have excellent transmittance, low yellowness index properties, good impact resistance, etc. Furthermore, with the recent increase in the importance of environmental considerations, there is a demand for the development of resins that are environmentally friendly, satisfy the above physical properties, and have improved transparency.

[0003] Patent Document 1 discloses a composition containing a polycarbonate and a carboxylic acid ester of isosorbide, which has improved rheological and optical properties. However, the disclosed material has a transmittance of only 89% at a thickness of 4 mm and a YI value of more than 2, so its physical properties are insufficient for use as a light guide.

[0004] Furthermore, Patent Document 2 discloses a block copolymer of [poly(isosorbide carbonate and aromatic carbonate-aromatic carbonate)]-[polycarbonate], which is environmentally friendly, has a high content of biomass-derived materials, and has a good balance of physical properties such as color, moldability, heat resistance, and impact resistance. However, the disclosed material is not intended to achieve physical properties for use as a light guide, such as improved optical properties. Therefore, in order to overcome the problems of the conventional techniques, there is a need to develop a resin composition that is environmentally friendly, has high transmittance, a low yellowness index, moldability, excellent mechanical properties such as tensile strength, and excellent heat resistance, and is particularly suitable for use in light guides. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent No. 10-2234098 [Patent Document 2] Korean Patent No. 10-1608411 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention solves the problems of the prior art and aims to provide a polycarbonate resin composition that is environmentally friendly, has improved optical properties (i.e., high transmittance and low yellowness index) compared to conventional polycarbonate resin compositions, and is also excellent in mechanical properties such as tensile strength, processability, and heat resistance, and a molded article (particularly, a light guide) containing the same. [Means for solving the problem]

[0007] In order to achieve the above object, one aspect of the present invention provides a thermoplastic resin composition comprising: (1) a polycarbonate resin as a base resin; (2) a polyalkylene glycol adduct of an anhydrosugar alcohol as a plasticizer component; and (3) a polyalkylene glycol; wherein, per 100 parts by weight of the total amount of the composition, the content of the polyalkylene glycol adduct of anhydrosugar alcohol is more than 0.5 parts by weight but less than 3 parts by weight, and the content of the polyalkylene glycol is less than 3 parts by weight. Another aspect of the present invention provides a molded article, preferably a light guide, comprising a thermoplastic resin composition according to the present invention. [Effects of the Invention]

[0008] The thermoplastic resin composition of the present invention is more environmentally friendly than conventional polycarbonate resin compositions, has improved optical properties (high transmittance and low yellowness index), and is also excellent in mechanical properties such as tensile strength, processability, and heat resistance. Therefore, molded articles containing the thermoplastic resin composition can be suitably used for optical applications in various industries, and can be particularly suitably used as light guides (more specifically, automotive light guides, and even more specifically, light guides for automotive headlamps). BEST MODE FOR CARRYING OUT THE INVENTION

[0009] The present invention will now be described in more detail. The thermoplastic resin composition of the present invention comprises a polycarbonate resin as a base resin; and a polyalkylene glycol adduct of an anhydrosugar alcohol as a plasticizer component.

[0010] (1) Base resin: Polycarbonate resin The polycarbonate resin contained as a base resin in the thermoplastic resin composition of the present invention may be an aromatic polycarbonate resin, but there are no particular limitations on the type of polycarbonate resin as long as the technical idea of ​​the present invention can be realized, and any thermoplastic aromatic polycarbonate resin conventionally used in this field can be used. In one embodiment, the aromatic polycarbonate resin can be prepared from a dihydric phenol, a carbonate precursor, and a molecular weight regulator.

[0011] The dihydric phenol is one of the monomers constituting the aromatic polycarbonate resin, and is represented by the following formula (1): [ka] [In the formula, X represents a linear, branched, or cyclic alkylene group having no functional group; or a linear, branched, or cyclic alkylene group containing one or more functional groups selected from the group consisting of a sulfide group, an ether group, a sulfoxide group, a sulfone group, a ketone group, a naphthyl group, and an isobutylphenyl group (for example, a linear alkylene group having 1 to 10 carbon atoms, or a branched or cyclic alkylene group having 3 to 10 carbon atoms), R1 and R2 each independently represent a halogen atom (e.g., Cl or Br), or a linear, branched, or cyclic alkyl group (e.g., a linear alkyl group having 1 to 20 carbon atoms (more specifically, 1 to 10), a branched alkyl group having 3 to 20 carbon atoms (more specifically, 3 to 10), or a cyclic alkyl group having 3 to 20 carbon atoms (more specifically, 3 to 6)); n and m independently represent an integer of 0 to 4.].

[0012] Non-limiting examples of the dihydric phenols include bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)phenylmethane, bis(4-hydroxyphenyl)naphthylmethane, bis(4-hydroxyphenyl)-(4-isobutylphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1-ethyl-1,1-bis(4-hydroxyphenyl)propane, 1-phenyl-1,1-bis(4-hydroxyphenyl)ethane, 1-naphthyl-1,1-bis(4-hydroxyphenyl)ethane, 1,2-bis(4-hydroxyphenyl)ethane, 1,10-bis(4-hydroxyphenyl)decane, 2-methyl-1,1-bis(4-hydroxyphenyl)propane, and 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), of which bisphenol A is preferred.

[0013] The carbonate precursor is another monomer that constitutes an aromatic polycarbonate resin, and non-limiting examples thereof include carbonyl chloride (phosgene), carbonyl bromide, bishaloformate, diphenyl carbonate, and dimethyl carbonate, with carbonyl chloride (phosgene) being preferred.

[0014] The molecular weight regulator may be a conventionally known compound, i.e., a monofunctional compound similar to the monomer used in the production of thermoplastic aromatic polycarbonate resins. Non-limiting examples of the molecular weight regulator include phenol derivatives (e.g., p-isopropylphenol, p-tert-butylphenol (PTBP), p-cumylphenol, p-isooctylphenol, p-isononylphenol, etc.), aliphatic alcohols, etc. Preferably, p-tert-butylphenol (PTBP) may be used. Examples of aromatic polycarbonate resins produced from such dihydric phenols, carbonate precursors, and molecular weight modifiers include linear polycarbonate resins, branched polycarbonate resins, copolycarbonate resins, and polyester carbonate resins. In the present invention, these resins can be used alone or in combination of two or more.

[0015] In one embodiment, the aromatic polycarbonate resin may have a viscosity average molecular weight (Mv, as measured in a methylene chloride solution at 25°C) of 15,000 to 40,000, more specifically 17,000 to 30,000, and even more specifically 20,000 to 30,000. If the aromatic polycarbonate resin has a viscosity average molecular weight of less than 15,000, mechanical properties such as impact strength and tensile strength may be reduced. Conversely, if it exceeds 40,000, the solution viscosity may increase, causing problems in resin processing.

[0016] In one embodiment, the polycarbonate base resin may be contained in an amount of, for example, 15 parts by weight or more, 20 parts by weight or more, 30 parts by weight or more, 40 parts by weight or more, 45 parts by weight or more, 50 parts by weight or more, 55 parts by weight or more, 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, or 90 parts by weight or more, relative to 100 parts by weight of the total amount of the thermoplastic resin composition of the present invention, and may be contained in an amount of 99.9 parts by weight or less, 99.8 parts by weight or less, 99.7 parts by weight or less, 99.6 parts by weight or less, 99.5 parts by weight or less, 99.4 parts by weight or less, 99.3 parts by weight or less, 99.2 parts by weight or less, 99.1 parts by weight or less, or 99 parts by weight or less.

[0017] (2) Plasticizer component: Polyalkylene glycol adduct of anhydrosugar alcohol The polyalkylene glycol adduct of anhydrosugar alcohol contained as a plasticizer component in the thermoplastic resin composition of the present invention is a compound in which a polyalkylene glycol substituent is attached to the terminal hydroxy group of an anhydrosugar alcohol.

[0018] The anhydrosugar alcohols can be produced by dehydrating hydrogenated sugars derived from natural products. Hydrogenated sugars (also called "sugar alcohols") are compounds obtained by adding hydrogen to the reducing end groups of sugars, and are generally referred to as HOCH2(CHOH). n It has the chemical formula CH2OH (where n is an integer between 2 and 5). Depending on the number of carbon atoms, hydrogenated sugars are classified into tetritols, pentitols, hexitols, and heptitols (4, 5, 6, and 7 carbon atoms, respectively). Among these, hexitols with 6 carbon atoms include sorbitol, mannitol, iditol, and galactitol, with sorbitol and mannitol being particularly useful materials. The anhydrosugar alcohol may be any of monoanhydrosugar alcohol, dianhydrosugar alcohol, or a mixture thereof, and although there is no particular limitation, dianhydrosugar alcohol can be used.

[0019] Monoanhydrosugar alcohols are anhydrosugar alcohols formed by removing one molecule of water from a hydrogenated sugar, and have a tetraol form with four hydroxy groups in the molecule. In the present invention, the type of monoanhydrosugar alcohol is not particularly limited, and is preferably a monoanhydrosugar hexitol, more specifically, 1,4-anhydrohexitol, 3,6-anhydrohexitol, 2,5-anhydrohexitol, 1,5-anhydrohexitol, 2,6-anhydrohexitol, or a mixture of two or more thereof.

[0020] Dianhydrosugar alcohols are anhydrosugar alcohols formed by removing two water molecules from hydrogenated sugars. They are diols with two hydroxyl groups per molecule and can be produced using starch-derived hexitol. Dianhydrosugar alcohols have long been attracting attention as environmentally friendly materials derived from renewable natural resources, and research into their production has been ongoing. Among these dianhydrosugar alcohols, isosorbide, produced from sorbitol, is currently the most widely used industrially.

[0021] The type of the dianhydrosugar alcohol is not particularly limited, but is preferably a dianhydrosugar hexitol, more specifically, 1,4:3,6-dianhydrohexitol. The 1,4:3,6-dianhydrohexitol may be isosorbide, isomannide, isoidide, or a mixture of two or more thereof. In one preferred embodiment of the present invention, the anhydrosugar alcohol may be isosorbide. In one embodiment, the polyalkylene glycol may be polyethylene glycol, polypropylene glycol, polybutylene glycol, or a combination thereof. In one embodiment, the molecular weight (weight average molecular weight) of the polyalkylene glycol may be, but is not limited to, 500 to 5000 g / mol, more specifically 1000 to 4000 g / mol.

[0022] In one embodiment, the polyalkylene glycol adduct of an anhydrosugar alcohol is represented by the following formula (2): [ka] (In the formula, [OAO] is a moiety derived from an anhydrosugar alcohol obtained by removing hydrogen atoms from both terminal hydroxy groups of the anhydrosugar alcohol, and H-[X] p are independently H-[O-alkylene] p and [X'] q -H independently represents an alkylene-O group. q -H, and p and q each independently represent an integer of 2 to 15. More specifically, in the formula (2), the anhydrosugar alcohol is isosorbide, the alkylene is a linear alkylene having 2 to 8 carbon atoms or a branched alkylene having 3 to 8 carbon atoms, more specifically, ethylene, propylene, butylene, or a combination thereof, and p and q each independently represent an integer of 2 to 12.

[0023] In one embodiment, the polyalkylene glycol adduct of an anhydrosugar alcohol is represented by the following formula (3): [ka] (In the formula, R 1 and R 2 each independently represents a linear alkylene group having 2 to 8 carbon atoms or a branched alkylene group having 3 to 8 carbon atoms, and m and n each independently represent an integer of 2 to 15. More specifically, in the formula (3), R 1 and R 2 each independently represents an ethylene group, a propylene group, an isopropylene group, or a butylene group, and preferably R 1 and R 2 are the same, m and n each independently represent an integer of 2 to 12.

[0024] In one embodiment, for example, as shown in the following reaction scheme, the polyalkylene glycol adduct of the anhydrosugar alcohol can be produced by reacting hydroxy groups at both ends or one end (preferably both ends) of the anhydrosugar alcohol with an alkylene oxide in the presence of a catalyst (e.g., a base catalyst), and the resulting compound is in a form in which the hydrogen atoms of the hydroxy groups at both ends or one end (preferably both ends) of the anhydrosugar alcohol are substituted with hydroxyalkyl groups that are in the ring-opened form of alkylene oxide. [ka]

[0025] In one embodiment, the alkylene oxide may be a linear alkylene oxide having 2 to 8 carbon atoms or a branched alkylene oxide having 3 to 8 carbon atoms, and more specifically, may be ethylene oxide, propylene oxide, butylene oxide, or a combination thereof.

[0026] In one embodiment, the anhydrosugar alcohol may be treated with an acid component before reaction with the alkylene oxide. The reaction between the acid-treated anhydrosugar alcohol and the alkylene oxide may be carried out, for example, in a high-pressure reactor capable of applying pressure (e.g., pressure of 3 MPa or more) in the presence of a base catalyst (e.g., an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, or an alkaline earth metal hydroxide such as calcium hydroxide) at a high temperature (e.g., 100°C to 180°C, or 120°C to 160°C) for, for example, 1 hour to 8 hours or 2 hours to 4 hours, but is not limited thereto. The reaction molar ratio of alkylene oxide to 1 mole of anhydrosugar alcohol may be, for example, 1 mole or more, 2 moles or more, or 3 moles or more, and may be 30 moles or less, 20 moles or less, 15 moles or less, or 12 moles or less, and may be, for example, 1 mole to 30 moles, preferably 2 to 20 moles, and more preferably 3 to 15 moles, but is not limited thereto.

[0027] The amount of the polyalkylene glycol adduct of anhydrosugar alcohol as a plasticizer component in the thermoplastic resin composition of the present invention is more than 0.5 parts by weight and less than 3 parts by weight, based on 100 parts by weight of the total amount of the thermoplastic resin composition. If the content of the polyalkylene glycol adduct of anhydrosugar alcohol is 0.5 parts by weight or less, based on 100 parts by weight of the total amount of the thermoplastic resin composition, the yellowness index of the composition increases. Conversely, if the content is 3 parts by weight or more, the plasticizer in the composition crystallizes, resulting in a decrease in transmittance.

[0028] In one embodiment, the amount of the polyalkylene glycol adduct of anhydrosugar alcohol as a plasticizer component in the resin composition, relative to 100 parts by weight of the total amount of the thermoplastic resin composition of the present invention, may be, for example, more than 0.5 parts by weight, 0.6 parts by weight or more, 0.7 parts by weight or more, 0.8 parts by weight or more, 0.9 parts by weight or more, or 1 part by weight or more, or may be less than 3 parts by weight, 2.9 parts by weight or less, 2.8 parts by weight or less, 2.7 parts by weight or less, 2.6 parts by weight or less, 2.5 parts by weight or less, 2.4 parts by weight or less, 2.1 parts by weight or less, 2 parts by weight or less, 1.9 parts by weight or less, 1.8 parts by weight or less, 1.7 parts by weight or less, 1.6 parts by weight or less, or 1.5 parts by weight or less.

[0029] (3) Polyalkylene glycol The polyalkylene glycol contained in the thermoplastic resin composition of the present invention is an independent component that is different from the polyalkylene glycol moiety in the polyalkylene glycol adduct of the anhydrosugar alcohol. The polyalkylene glycol is an ether polymer composed of units derived from alkylene glycol, and the alkylene group may be a linear alkylene group or a branched alkylene group.

[0030] In one embodiment, the polyalkylene glycol may be a polymer composed of units derived from an alkylene glycol having 2 to 6 carbon atoms. More specifically, such alkylene glycol is selected from, for example, ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, neopentyl glycol, 3-methyltetramethylene glycol, hexamethylene glycol, and combinations thereof. It is preferable that the alkylene glycol having 3 to 6 carbon atoms is selected from, for example, propylene glycol, butylene glycol, trimethylene glycol, tetramethylene glycol, and combinations thereof.

[0031] In one embodiment, the polyalkylene glycol may be a homopolymer of a single alkylene glycol or a random copolymer or block copolymer of two or more alkylene glycols. More specifically, the polyalkylene glycol may be, for example, polyethylene glycol, polypropylene glycol, polybutylene glycol, polypentylene glycol, polyhexylene glycol, polytrimethylene glycol, polytetramethylene glycol, Poly Pentamethylene Gri Ko - The polyol is selected from polypropylene glycol, polybutylene glycol, polytrimethylene glycol, polytetramethylene glycol, and combinations thereof, and is preferably selected from polypropylene glycol, polybutylene glycol, polytrimethylene glycol, polytetramethylene glycol, and combinations thereof.

[0032] In one embodiment, the polyalkylene glycol may be capped at one or both ends with an alkyl ether, an aryl ether, an aralkyl ether, a fatty acid ester, an aryl ester, an aralkyl ester, or the like, and an ether or ester form may also be used without any adverse effect.

[0033] The alkyl group constituting the alkyl ether may be a linear and / or branched alkyl group, and more specifically, may be an alkyl group having 1 to 22 carbon atoms, such as a methyl group, ethyl group, propyl group, butyl group, octyl group, lauroyl group, stearyl group, etc. That is, in one embodiment, the polyalkylene glycol capped with an alkyl ether may be a methyl ether, ethyl ether, butyl ether, lauryl ether, stearyl ether, etc. of a polyalkylene glycol.

[0034] Specific examples of the aryl group constituting the aryl ether include aryl groups having 6 to 22 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group, with a phenyl group, a tolyl group, and the like being preferred.

[0035] Specific examples of the aralkyl group constituting the aralkyl ether include aralkyl groups having 7 to 23 carbon atoms, 7 to 13 carbon atoms, and 7 to 11 carbon atoms, such as benzyl and phenethyl groups, with benzyl being preferred.

[0036] The fatty acid constituting the fatty acid ester may be a linear and / or branched fatty acid, and may be a saturated or unsaturated fatty acid. More specifically, it may be a monovalent or divalent saturated or unsaturated fatty acid having 1 to 22 carbon atoms. Even more specifically, it may be a monovalent saturated fatty acid (e.g., formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, etc.), a monovalent unsaturated fatty acid (e.g., oleic acid, elaidic acid, linoleic acid, linolenic acid, arachidonic acid, etc.), or a divalent fatty acid having 10 or more carbon atoms (e.g., sebacic acid, undecanedioic acid, dodecanedioic acid, tetradecanedioic acid, taphciaic acid, etc.). acid) and decenedioic acid, undecenedioic acid, dodecenedioic acid, etc.

[0037] Specific examples of the aryl group constituting the aryl ester include aryl groups having 6 to 22 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group, with a phenyl group and a tolyl group being preferred.

[0038] Specific examples of the aralkyl group constituting the aralkyl ester include aralkyl groups having 7 to 23 carbon atoms, 7 to 13 carbon atoms, or 7 to 11 carbon atoms, such as a benzyl group and a phenethyl group, with a benzyl group being preferred.

[0039] In one embodiment, the number average molecular weight (Mn, g / mol) of the polyalkylene glycol may be 700 or more or 800 or more, and may be 4,000 or less or 3,000 or less. If the number average molecular weight of the polyalkylene glycol is too high, compatibility may decrease, while if it is too low, gas may be generated during molding.

[0040] The number average molecular weight of the polyalkylene glycol may be a number average molecular weight calculated based on a hydroxyl value measured in accordance with JIS K1577. The content of the polyalkylene glycol in the resin composition of the present invention is less than 3 parts by weight per 100 parts by weight of the total amount of the thermoplastic resin composition. If the content of polyalkylene glycol per 100 parts by weight of the total amount of the thermoplastic resin composition is 3 parts by weight or more, the yellowness index of the composition increases, the resin becomes cloudy, the transmittance decreases, and the amount of deposits on the mold increases due to gas derived from the polyalkylene glycol. There is no particular lower limit for the content of the polyalkylene glycol, but if the amount used is too small, the improvement in color tone and yellowing may be insufficient, and the effect of reducing gas generation may be insufficient.

[0041] In one embodiment, the content of the polyalkylene glycol, relative to 100 parts by weight of the total amount of the thermoplastic resin composition of the present invention, may be, for example, 0.01 parts by weight or more, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.15 parts by weight or more, 0.2 parts by weight or more, or 0.25 parts by weight or more, or may be less than 3 parts by weight, 2.9 parts by weight or less, 2.5 parts by weight or less, 2 parts by weight or less, 1.5 parts by weight or less, 1 part by weight or less, or 0.75 parts by weight or less.

[0042] Phosphorus-based heat stabilizer The polycarbonate resin composition of the present invention may further contain a phosphorus-based heat stabilizer in order to improve the color tone of the composition and enhance the heat resistance and discoloration resistance. Any known phosphorus-based heat stabilizer may be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal acid pyrophosphates such as sodium acid pyrophosphate, potassium acid pyrophosphate, and calcium acid pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; phosphate compounds, phosphite compounds, and phosphonite compounds. Phosphite compounds are preferably used in terms of discoloration resistance and continuous productivity, but the present invention is not limited to these.

[0043] In one embodiment, the phosphite compound may be a trivalent phosphorus compound represented by the formula: P(OR)3, where R represents a monovalent or divalent organic group. More specifically, the phosphite compound may be, for example, triphenyl phosphite, tris(mononylphenyl)phosphite, tris(mononyl / dinonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, monooctyldiphenyl phosphite, dioctylmonophenyl phosphite, monodecyldiphenyl phosphite, didecylmonophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)phosphite, butyl-4-methylphenyl)pentaerythritol phosphite, bis(2,6-di-tert-butylphenyl)octyl phosphate, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphate, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene-diphosphite, 6-[3-(3-tert-butyl-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]-dioxaphosphepine, and the like. The phosphorus-based heat stabilizers may be used alone or in combination of two or more.

[0044] In one embodiment, the content of the phosphorus-based heat stabilizer in the composition may be 0.05 to 0.5 parts by weight, relative to 100 parts by weight of the total amount of the thermoplastic resin composition of the present invention. If the content of the phosphorus-based heat stabilizer in the composition is too low below this range, the effect of improving color and yellowing may be insufficient. Conversely, if the content is too high above this range, the heat resistance and color fastness tend to decrease, and stability against moisture and heat also tends to decrease.

[0045] More specifically, the content of the phosphorus-based heat stabilizer may be, for example, 0.05 parts by weight or more, 0.07 parts by weight or more, 0.1 parts by weight or more, 0.12 parts by weight or more, or 0.15 parts by weight or more, relative to 100 parts by weight of the total amount of the thermoplastic resin composition of the present invention, or may be 0.5 parts by weight or less, 0.45 parts by weight or less, 0.4 parts by weight or less, 0.35 parts by weight or less, 0.3 parts by weight or less, or 0.25 parts by weight or less.

[0046] Any other additives The thermoplastic resin composition of the present invention may further contain other additives, if necessary, in addition to the above-mentioned components, within the scope of achieving the object of the present invention. The types and contents of the other additives can be easily selected by those skilled in the art depending on various purposes. In one embodiment, inorganic fillers, lubricants, antioxidants, light stabilizers, hydrolysis stabilizers, release agents, colorants, UV stabilizers, antistatic agents, conductivity-imparting agents, magnetism-imparting agents, crosslinking agents, antibacterial agents, processing aids, antifriction agents, antiwear agents, and coupling agents can be added to the composition alone or as a mixture of two or more.

[0047] The antioxidant may be a phenol-based, phosphite-based, thioether-based, or amine-based antioxidant; the release agent may be a fluorine-containing polymer, silicone oil, metal salt of stearic acid, metal salt of montanic acid, montanic acid ester wax, or polyethylene wax; the UV stabilizer may be a benzophenone-based, benzotriazole-based, or amine-based UV stabilizer; and the colorant may be a dye or pigment. In addition, as additives other than those described above, commercially available general additives can be used, and the amount of additives to be added is not particularly limited, and can be, for example, 0.1 to 5 parts by weight, more specifically 0.2 to 5 parts by weight, relative to 100 parts by weight of the total amount of the composition of the present invention, but is not limited thereto.

[0048] The thermoplastic resin composition according to the present invention is environmentally friendly because it uses an anhydrosugar alcohol, which is a biomass-derived material, and has improved optical properties (i.e., high transmittance and low yellowness index) compared to conventional polycarbonate resin compositions. It also has excellent mechanical properties such as tensile strength, processability, and heat resistance. Therefore, molded articles containing the composition can be suitably used for optical applications in various industries, and can be particularly suitably used as light guides (more specifically, automotive light guides, and even more specifically, light guides for automotive headlamps). Therefore, according to another aspect of the present invention, there is provided a molded article comprising the thermoplastic resin composition of the present invention. The molded article may be an extrusion molded or injection molded article of the thermoplastic resin composition of the present invention. In a preferred embodiment, the molded article may be a light guide. The present invention will be described in more detail with reference to the following examples and comparative examples, but the scope of the present invention is not limited thereto. [Example]

[0049] The components used in the examples and comparative examples are as follows. (A) Polycarbonate resin: 3017 PJ manufactured by SAMYANG CORPORATION. (B) Polypropylene glycol adduct of isosorbide (B-1) PI-1000 (polypropylene glycol molecular weight: 1000 g / mol) (B-2) PI-2000 (polypropylene glycol molecular weight: 2000 g / mol) (B-3) PI-4000 (polypropylene glycol molecular weight: 4000 g / mol) (C) Polypropylene glycol (PPG) (C-1)PPG-1000 (molecular weight: 1000g / mol) (C-2)PPG-2000 (molecular weight: 2000g / mol) (C-3)PPG-4000 (molecular weight: 4000g / mol) (D) Phosphorus-based heat stabilizer (S9228PC, manufactured by Dover)

[0050] The polypropylene glycol adduct of isosorbide was produced by subjecting acid-treated isosorbide to an addition reaction with the corresponding propylene oxide in the presence of a KOH catalyst at 100 to 140°C, cooling the product, filtering it, and purifying it using an ion exchange resin.

[0051] Resin compositions were prepared using the components and amounts of each of the examples and comparative examples shown in Table 1 below, and extruded using a twin-screw melt kneading extruder with L / D=48 and Φ=25 mm under conditions of a melt temperature of 240 to 260°C, a screw rotation speed of 150 rpm, a first vent pressure of about -600 mmHg, and a self-feed rate of 20 kg / h. The extruded strand was cooled with water and then cut with a rotary cutter to prepare pellets. The produced pellets were dried with hot air at 80-100°C for 4 hours, and then injection molded at a cylinder temperature of 250-280°C and a molding temperature of 80°C to produce specimens. The physical properties of each produced specimen were measured by the methods described below, and the results are shown in Table 1 below.

[0052] The physical properties of each specimen were measured by the following methods. (1) Tensile strength: Evaluated according to ASTM D638 (2) Flexural strength and flexural modulus: Evaluated according to ASTM D790 (3) Impact Strength: Evaluated according to ASTM D256 (1 / 8 inch thick, notched Izod) (4) Heat distortion temperature: 18.6 kg / cm according to ASTM D648 2 Evaluated under load (5) Melt index: Measured according to ASTM D1238 at a temperature of 300°C and a load of 1.2 kgf. (6) Transmittance: Using a Gardner Haze Meter manufactured by BYK, the transmittance (%) of a square specimen (90 x 80 x 6.4 mm) was measured in accordance with ASTM D1003. (7) YI (Yellowness Index): The YI value of a square specimen (90 x 80 x 6.4 mm) was measured using a spectrophotometer CI 7800SE manufactured by X-rite. [Table 1]

[0053] [Table 2]

[0054] As shown in Table 1, all of Examples 1 to 6 according to the present invention were excellent in optical properties (i.e., high transmittance and low yellowness index), and at the same time, were excellent in processability (high melting index), mechanical properties such as tensile strength, flexural strength, flexural modulus and impact strength, and heat resistance, ensuring well-balanced physical properties, and were suitable for use as light guides for automobile headlights. However, as shown in Table 2, the comparative examples had inferior optical properties compared to the examples (ie, low transmittance and high yellowness index).

Claims

1. A thermoplastic resin composition, (1) Polycarbonate resin as the base resin; (2) a polyalkylene glycol adduct of an anhydrosugar alcohol as a plasticizer component; and (3) polyalkylene glycol; Including, A thermoplastic resin composition, wherein the content of the polyalkylene glycol adduct of the anhydrosugar alcohol is 1 part by weight or more and 2 parts by weight or less, and the content of the polyalkylene glycol is 0.75 parts by weight or less, relative to 100 parts by weight of the total amount of the composition.

2. 2. The thermoplastic resin composition according to claim 1, wherein the polycarbonate resin (1) is a thermoplastic aromatic polycarbonate resin.

3. 2. The thermoplastic resin composition according to claim 1, wherein the anhydrosugar alcohol in the (2) polyalkylene glycol adduct of anhydrosugar alcohol is isosorbide.

4. 2. The thermoplastic resin composition according to claim 1, wherein the polyalkylene glycol in the (2) polyalkylene glycol adduct of an anhydrosugar alcohol is polyethylene glycol, polypropylene glycol, polybutylene glycol, or a combination thereof.

5. The (2) polyalkylene glycol adduct of anhydrosugar alcohol is represented by the following formula (2): 【Chemistry 1】 (In the formula, [O-A-O] is a moiety derived from an anhydrosugar alcohol obtained by removing hydrogen atoms from both terminal hydroxy groups of the anhydrosugar alcohol, and H-[X] p are independently H-[O-alkylene] p and [X'] q -H is independently [alkylene-O] q 2. The thermoplastic resin composition according to claim 1, wherein p and q each independently represent an integer of 2 to 15.

6. The polyalkylene glycol adduct of anhydrosugar alcohol (2) is represented by the following formula (3): 【Chemistry 2】 (In the formula, R 1 and R 2 each independently represent a linear alkylene group having 2 to 8 carbon atoms or a branched alkylene group having 3 to 8 carbon atoms, and m and n each independently represent an integer of 2 to 15.

7. The thermoplastic resin composition according to claim 1, wherein the (3) polyalkylene glycol is selected from the group consisting of polyethylene glycol, polypropylene glycol, polybutylene glycol, polypentylene glycol, polyhexylene glycol, polytrimethylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene glycol, and combinations thereof.

8. The thermoplastic resin composition according to claim 1, further comprising a phosphorus-based heat stabilizer.

9. A molded article comprising the thermoplastic resin composition according to any one of claims 1 to 8.

10. 10. The molded article according to claim 9, which is a light guide.

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