Polycarbonate resin composition having excellent optical properties and long-term heat resistance, and molded article comprising same

Abstract

The present invention relates to a polycarbonate resin composition and a molded article comprising same and, more specifically, to a polycarbonate resin composition and a molded article comprising same, the composition comprising: polycarbonate as a base resin; as a plasticizer component, a polyalkylene glycol adduct of anhydrosugar alcohol, which is a biomass-derived substance; a phosphorus-based heat stabilizer; and an epoxy-based stabilizer, and having excellent processability and mechanical properties such as tensile strength while exhibiting excellent long-term heat resistance and optical properties.

Description

Polycarbonate resin composition with excellent optical properties and long-term heat resistance and molded article comprising the same

[0001] The present invention relates to a polycarbonate resin composition and a molded article comprising the same, and more particularly, to a polycarbonate resin composition comprising polycarbonate as a base resin, a polyalkylene glycol adduct of anhydrous sugar alcohol, which is a biomass-derived material, as a plasticizer component, a phosphorus-based heat stabilizer, and an epoxy-based stabilizer, which exhibits excellent long-term heat resistance and optical properties, as well as excellent mechanical properties such as tensile strength and processability, and a molded article comprising the same.

[0002] Light guides used in automobile headlamps, lighting components for various electronic devices, and housings require resins with a high melting index to ensure uniform thickness. These resins must also possess excellent permeability, a low yellowing index, and impact resistance. Furthermore, with the growing emphasis on environmental friendliness, there is a growing need for the development of eco-friendly resins that simultaneously satisfy the aforementioned properties and offer improved transparency.

[0003] Korean Patent No. 10-2234098 discloses a composition containing a carboxylic acid ester of polycarbonate and isosorbide with improved rheological and optical properties. However, the material has a transmittance of only 89% at a thickness of 4 mm, and a YI value exceeding 2, which means that the material has insufficient properties for use as a light guide.

[0004] In addition, in the case of Korean Patent Registration No. 10-1608411, an eco-friendly [poly(isosorbide carbonate and aromatic carbonate-aromatic carbonate)]-[polycarbonate] block copolymer with a high content of biomass-derived materials and an excellent balance of physical properties such as color, moldability, heat resistance, and impact resistance is disclosed, but this does not aim to implement physical properties for use as a light guide, such as long-term heat resistance and improved optical properties.

[0005] Therefore, there is a need for the development of a resin composition that overcomes the problems of the above existing technologies, is environmentally friendly, exhibits excellent long-term heat resistance and optical properties (i.e., high transmittance and low yellowness index), and at the same time has excellent mechanical properties such as tensile strength and processability, making it particularly suitable for use as a light guide.

[0006] The present invention is intended to solve the problems of the prior art as described above, and has as its technical task the provision of a polycarbonate resin composition which is environmentally friendly and exhibits superior long-term heat resistance and optical properties (i.e., high transmittance and low yellowness index) compared to the conventional polycarbonate resin composition, while also having superior mechanical properties such as tensile strength and processability, and a molded article (particularly, a light guide) comprising the same.

[0007] In order to solve the above technical problem, 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 anhydrous sugar alcohol as a plasticizer component; (3) a phosphorus-based heat stabilizer; and (4) an epoxy-based stabilizer.

[0008] Another aspect of the present invention provides a molded article, preferably a light guide, comprising a thermoplastic resin composition according to the present invention.

[0009] The thermoplastic resin composition according to the present invention is environmentally friendly and exhibits excellent long-term heat resistance and optical properties (i.e., high transmittance and low yellowness index) compared to conventional polycarbonate resin compositions, while also having excellent mechanical properties such as tensile strength and processability, so that a molded article including the same can be suitably used for optical purposes in various industries, and in particular, can be very suitably used as a light guide (more specifically, a light guide for an automobile, and even more specifically, a light guide for an automobile headlamp).

[0010] Hereinafter, the present invention will be described in more detail.

[0011] The thermoplastic resin composition of the present invention comprises (1) a polycarbonate resin as a base resin; (2) a polyalkylene glycol adduct of anhydrous sugar alcohol as a plasticizer component; (3) a phosphorus-based heat stabilizer; and (4) an epoxy-based stabilizer.

[0012] (1) Base resin: polycarbonate resin

[0013] As a polycarbonate resin included as a base resin in the thermoplastic resin composition of the present invention, an aromatic polycarbonate resin may be used. However, as long as it can implement the technical idea of ​​the present invention, the type thereof is not particularly limited, and a thermoplastic aromatic polycarbonate resin commonly used in the relevant field may be used.

[0014] In one specific example, the aromatic polycarbonate resin can be prepared from a dihydric phenol, a carbonate precursor, and a molecular weight modifier.

[0015] The above divalent phenols are one of the monomers constituting the aromatic polycarbonate resin and may be represented by the following chemical formula 1.

[0016] [Chemical Formula 1]

[0017]

[0018] In the above chemical formula 1,

[0019] X represents a linear, branched or cyclic alkylene group having no functional group; or a linear, branched or cyclic alkylene group including 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 (e.g., a linear alkylene group having 1 to 10 carbon atoms, or a branched or cyclic alkylene group having 3 to 10 carbon atoms),

[0020] 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),

[0021] n and m independently represent integers from 0 to 4.

[0022] Non-limiting examples of the above diphenols 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, Examples include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), and bisphenol A is preferably used.

[0023] The above carbonate precursor is another monomer constituting the aromatic polycarbonate resin, and non-limiting examples thereof include carbonyl chloride (phosgene), carbonyl bromide, bishalo formate, diphenyl carbonate, dimethyl carbonate, etc., and carbonyl chloride (phosgene) can be preferably used.

[0024] The molecular weight modifier may be a material already known in the art, i.e., a monofunctional compound similar to a monomer used in the production of thermoplastic aromatic polycarbonate resin. Non-limiting examples of the molecular weight modifier include phenol-based derivatives (e.g., para-isopropylphenol, para-tert-butylphenol (PTBP), para-cumylphenol, para-isooctylphenol, para-isononylphenol, etc.), aliphatic alcohols, etc. Preferably, para-tert-butylphenol (PTBP) may be used.

[0025] Examples of aromatic polycarbonate resins manufactured from such divalent phenols, carbonate precursors and molecular weight modifiers include linear polycarbonate resins, branched polycarbonate resins, copolycarbonate resins and polyester carbonate resins, and these may be used alone or in combination of two or more.

[0026] In one specific example, the viscosity average molecular weight (Mv, measured in a 25°C methylene chloride solution) of the aromatic polycarbonate resin may be 15,000 to 40,000, more specifically 17,000 to 30,000, and even more specifically 20,000 to 30,000. If the viscosity average molecular weight of the aromatic polycarbonate resin is less than 15,000, mechanical properties such as impact strength and tensile strength may deteriorate, and if it exceeds 40,000, the melt viscosity may increase, causing problems in processing the resin.

[0027] In one specific example, within the total 100 parts by weight of the thermoplastic resin composition of the present invention, the polycarbonate base resin may be included in an amount of, for example, 89 parts by weight or more, 90 parts by weight or more, 91 parts by weight or more, 92 parts by weight or more, 93 parts by weight or more, 94 parts by weight or more, 95 parts by weight or more, 96 parts by weight or more, or 97 parts by weight or more, and may also be included in an amount of 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.

[0028] (2) Plasticizer component: Polyalkylene glycol adduct of anhydrous sugar alcohol

[0029] The polyalkylene glycol adduct of anhydrous sugar alcohol included 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 hydroxyl group of anhydrous sugar alcohol.

[0030] The above anhydrous sugar alcohol can be produced by dehydration of hydrogenated sugars derived from natural products. Hydrogenated sugar (also called “sugar alcohol”) refers to a compound obtained by adding hydrogen to the reducing terminal group of a sugar, and is generally expressed as HOCH2(CHOH). n It has the chemical formula CH2OH (where n is an integer from 2 to 5) and is classified into tetrintol, pentitol, hexitol, and heptitol (having 4, 5, 6, and 7 carbon atoms, respectively) depending on the number of carbon atoms. Among them, hexitols with 6 carbon atoms include sorbitol, mannitol, iditol, galactitol, etc., and sorbitol and mannitol are particularly useful substances.

[0031] The above anhydrous alcohol may be monoanhydrous alcohol, dianhydrous alcohol or a mixture thereof, and although not particularly limited, dianhydrous alcohol may be used.

[0032] Monoanhydrosugar alcohol is an anhydrosugar alcohol formed by removing one water molecule from the interior of a hydrogenated sugar, and has a tetraol form with four hydroxyl groups in the molecule. In the present invention, the type of monoanhydrosugar alcohol is not particularly limited, but preferably, it may be monoanhydrosugar hexitol, and more specifically, it may be 1,4-anhydrohexitol, 3,6-anhydrohexitol, 2,5-anhydrohexitol, 1,5-anhydrohexitol, 2,6-anhydrohexitol, or a mixture of two or more thereof.

[0033] Anhydrosugar alcohols are anhydrosugar alcohols formed by the removal of two water molecules from the interior of hydrogenated sugars. They have a diol structure with two hydroxyl groups within the molecule and can be manufactured using hexitols derived from starch. Anhydrosugar alcohols have long been the subject of considerable interest and research into their manufacturing methods, as they are environmentally friendly substances derived from renewable natural resources. Among these dianhydrosugar alcohols, isosorbide, manufactured from sorbitol, currently has the widest range of industrial applications.

[0034] The type of the above-mentioned dianhydrosugar alcohol is not particularly limited, but preferably it may be a dianhydrosugar hexitol, and more specifically, it may be 1,4:3,6-dianhydrohexitol. The above-mentioned 1,4:3,6-dianhydrohexitol may be isosorbide, isomannide, isoidide, or a mixture of two or more thereof.

[0035] In a preferred embodiment of the present invention, the anhydrous sugar alcohol may be isosorbide.

[0036] In one specific example, the polyalkylene glycol may be polypropylene glycol, polybutylene glycol, or a combination thereof.

[0037] In one specific example, the molecular weight (weight average molecular weight) of the polyalkylene glycol may be 500 to 5000 g / mol, more specifically 1000 to 4000 g / mol, but is not limited thereto.

[0038] In one specific example, the polyalkylene glycol adduct of the anhydrous sugar alcohol may be represented by the following chemical formula 2.

[0039] [Chemical Formula 2]

[0040] H-[X] p -[OAO]-[X'] q -H

[0041] In the above chemical formula 2,

[0042] [OAO] is a moiety derived from anhydrosugar alcohol in which a hydrogen atom is removed from the terminal hydroxyl group of anhydrosugar alcohol.

[0043] H-[X] p is independently H-[O-alkylene] p And,

[0044] [X'] q -H is independently [alkylene-O] q -H and,

[0045] p and q each independently represent an integer from 2 to 15.

[0046] More specifically, in the above chemical formula 2,

[0047] Anhydrous alcohol may be isosorbide.

[0048] In addition, the above alkylene may be a linear or branched alkylene having 3 to 8 carbon atoms, and more specifically, may be propylene, butylene, or a combination thereof,

[0049] p and q can each independently represent an integer from 2 to 12.

[0050] In one specific example, the polyalkylene glycol adduct of the anhydrous sugar alcohol may be a compound represented by the following chemical formula 3.

[0051] [Chemical Formula 3]

[0052]

[0053] In the above chemical formula 3,

[0054] R 3 and R 4 Each independently represents a linear or branched alkylene group having 3 to 8 carbon atoms,

[0055] m and n each independently represent an integer from 2 to 15.

[0056] More specifically, in the above chemical formula 3,

[0057] R 3 and R 4 Each independently represents a propylene group or a butylene group, preferably R 3 and R 4 are identical to each other,

[0058] m and n each independently represent an integer from 2 to 12.

[0059] In one specific example, the polyalkylene glycol adduct of the anhydrous sugar alcohol can be obtained as a compound in which the hydrogen of the hydroxyl groups at both terminals or one terminal (preferably both terminals) of the anhydrous sugar alcohol is substituted with a hydroxyalkyl group, which is a ring-opened form of the alkylene oxide, by reacting the hydroxyl groups at both terminals or one terminal (preferably both terminals) of the anhydrous sugar alcohol with an alkylene oxide in the presence of a catalyst (e.g., a base catalyst), as shown in the reaction schematic below.

[0060]

[0061] In one specific embodiment, the alkylene oxide may be a linear or branched alkylene oxide having 3 to 8 carbon atoms, and more specifically, may be propylene oxide, butylene oxide, or a combination thereof.

[0062] In one specific embodiment, the anhydrous sugar alcohol may be treated with an acid component before reacting with the alkylene oxide, and the reaction of the anhydrous sugar alcohol treated with the acid component with the alkylene oxide may be performed, for example, in a high-pressure reactor capable of pressurization (for example, a pressure of 3 MPa or more), in the presence of a base catalyst (for example, a hydroxide of an alkali metal such as sodium hydroxide or potassium hydroxide, or a hydroxide of an alkaline earth metal such as calcium hydroxide), at an elevated temperature (for example, 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 the anhydrous sugar alcohol and the alkylene oxide is, for example, 1 mol or more, 2 mol or more, or 3 mol or more of the alkylene oxide per 1 mol of the anhydrous sugar alcohol, and also 30 mol or less, 20 mol or less, 15 mol or less, or 12 mol or less, and may be, for example, 1 mol to 30 mol, preferably 2 mol to 20 mol, and more preferably 3 mol to 15 mol, but is not limited thereto.

[0063] In one specific example, the thermoplastic resin composition of the present invention may contain a polyalkylene glycol adduct of the anhydrous sugar alcohol as a plasticizer component in an amount of more than 0.3 parts by weight and less than 5 parts by weight within a total of 100 parts by weight. If the content of the polyalkylene glycol adduct of the anhydrous sugar alcohol within the total of 100 parts by weight of the thermoplastic resin composition is 0.3 parts by weight or less or 5 parts by weight or more, the mechanical properties, long-term heat resistance, and optical properties of the composition may deteriorate.

[0064] In one specific example, the thermoplastic resin composition of the present invention may contain, in a total of 100 parts by weight, a polyalkylene glycol adduct of the anhydrous sugar alcohol as a plasticizer component in an amount of, for example, more than 0.3 parts by weight, 0.4 parts by weight or more, 0.5 parts by weight or more, 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, and may also contain, but is not limited to, an amount of less than 5 parts by weight, 4.9 parts by weight or less, 4.5 parts by weight or less, 4 parts by weight or less, 3.5 parts by weight or less, 3 parts by weight or less, or 2.5 parts by weight or less.

[0065] In one specific embodiment, the thermoplastic resin composition of the present invention may not contain polyalkylene glycol as an independent component different from the polyalkylene glycol moiety in the polyalkylene glycol adduct of the anhydrous sugar alcohol, or may contain it in an amount of less than 0.5 parts by weight (e.g., 0.001 to less than 0.5 parts by weight) based on 100 parts by weight of the total composition, and preferably, the thermoplastic resin composition of the present invention does not contain polyalkylene glycol. Here, the polyalkylene glycol may be, for example, polyethylene glycol, polypropylene glycol, polybutylene glycol, polypentylene glycol, polyhexylene glycol, polytrimethylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene glycol, or a combination thereof.

[0066] (3) Heat stabilizer

[0067] The polycarbonate resin composition of the present invention includes a phosphorus-based heat stabilizer to improve the color and heat and discoloration resistance of the composition. By using the phosphorus-based heat stabilizer of the present invention, transmittance, heat resistance, and discoloration resistance can be improved simultaneously.

[0068] The above-mentioned heat stabilizer may be a pentaerythritol diphosphite-based heat stabilizer. For example, it may be a pentaerythritol diphosphite-based heat stabilizer containing four or more benzene rings (e.g., 4 to 8), more specifically, five or more benzene rings (e.g., 5 to 7).

[0069] In one specific example, the phosphorus heat stabilizer may be a compound represented by the following chemical formula 4.

[0070] [Chemical Formula 4]

[0071]

[0072] In the above chemical formula 4,

[0073] R 5 , R 6 , R 7 and R 8 are each independently C2~C9 alkyl or cumyl, and R 5 Inland R 8 At least two of them are cumil.

[0074] In one specific example, the phosphorus heat stabilizer may be a phosphorus heat stabilizer containing a dicumylphenyl group, and more specifically, may be bis(2,4-dicumylphenyl)pentaerythritol diphosphite having the following structure:

[0075]

[0076] In one specific example, the phosphorus-based heat stabilizer may be included in an amount of more than 0.01 parts by weight and less than 5 parts by weight within a total of 100 parts by weight of the thermoplastic resin composition of the present invention. If the content of the phosphorus-based heat stabilizer within a total of 100 parts by weight of the thermoplastic resin composition is 0.01 parts by weight or less or 5 parts by weight or more, the mechanical properties, long-term heat resistance, and optical properties of the composition may deteriorate.

[0077] In one specific example, in the total 100 parts by weight of the thermoplastic resin composition of the present invention, the phosphorus-based heat stabilizer may be included in an amount of, for example, more than 0.01 parts by weight, 0.02 parts by weight or more, 0.03 parts by weight or more, 0.04 parts by weight or more, 0.05 parts by weight or more, 0.06 parts by weight or more, 0.07 parts by weight or more, 0.08 parts by weight or more, 0.09 parts by weight or more, 0.1 parts by weight or more, 0.11 parts by weight or more, 0.12 parts by weight or more, 0.13 parts by weight or more, 0.14 parts by weight or more, or 0.15 parts by weight or more, and also less than 5 parts by weight, 4.9 parts by weight or less, 4.5 parts by weight or less, 4 parts by weight or less, 3.5 parts by weight or less, 3 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, or 1 part by weight or less. or may be included in an amount of 0.5 parts by weight or less, but is not limited thereto.

[0078] (4) Epoxy stabilizer

[0079] The polycarbonate resin composition of the present invention includes an epoxy stabilizer to improve the mechanical properties of the composition and enhance heat and discoloration resistance. By using the epoxy stabilizer of the present invention, transmittance, heat resistance, and discoloration resistance can be improved simultaneously.

[0080] As the above epoxy stabilizer, a known one can be used, and for example, an alicyclic epoxy compound that does not contain an aromatic group can be used, but is not limited thereto.

[0081] In one embodiment, the epoxy stabilizer may be an alicyclic diepoxy compound, for example, selected from the group consisting of diethylene glycol bis(3,4-epoxycyclohexane-carboxylate), bis(3,4-epoxycyclohexylmethyl) oxalate, bis(3,4-epoxycyclohexylmethyl) succinate, 1-methyl-3,4-epoxycyclohexylmethyl 1-methyl-3,4-epoxycyclohexane-carboxylate, or combinations thereof.

[0082] In one specific example, the epoxy stabilizer may be 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate having the following structure:

[0083]

[0084] In one specific example, the epoxy stabilizer may be included in an amount of more than 0.03 parts by weight and less than 1 part by weight within a total of 100 parts by weight of the thermoplastic resin composition of the present invention. If the content of the epoxy stabilizer within a total of 100 parts by weight of the thermoplastic resin composition is 0.01 parts by weight or less or 1 part by weight or more, the mechanical properties, long-term heat resistance, and / or optical properties of the composition may deteriorate.

[0085] In one specific example, the epoxy stabilizer may be included in an amount of, for example, more than 0.01 part by weight, 0.02 part by weight or more, 0.03 part by weight or more, 0.04 part by weight or more, or 0.05 part by weight or more, and may also be included in an amount of less than 1 part by weight, 0.9 part by weight or less, 0.8 part by weight or less, 0.7 part by weight or less, 0.6 part by weight or less, 0.5 part by weight or less, 0.4 part by weight or less, or 0.3 part by weight or less, but is not limited thereto.

[0086] Any additional additives

[0087] In addition to the components described above, the thermoplastic resin composition of the present invention may further include additional additives as needed within a range that can achieve the purpose of the present invention.

[0088] The types and contents of the above-described additional additives can be easily selected by those skilled in the art according to various purposes. As a specific example, inorganic fillers, lubricants, antioxidants, light stabilizers, hydrolysis stabilizers, release agents, colorants, UV stabilizers, antistatic agents, conductivity-imparting agents, magnetic-imparting agents, crosslinking agents, antibacterial agents, processing aids, antifriction agents, antiwear agents, and coupling agents can be added to the composition alone or in combination of two or more.

[0089] As the antioxidant, a phenol-type, phosphite-type, thioether-type or amine-type antioxidant can be used, and as the release agent, a fluorine-containing polymer, silicone oil, a metal salt of stearic acid, a metal salt of montanic acid, a montanic acid ester wax or polyethylene wax can be used. In addition, as the UV stabilizer, benzophenone or benzotriazole and an amine-type UV stabilizer can be used, and as the colorant, a dye or pigment can be used.

[0090] In addition, other additional additives can be used that are generally commercially available. The content of the additional additive is not particularly limited, and depending on the purpose and use, it can be used in an amount of, for example, 0.1 to 5 parts by weight, more specifically, 0.2 to 5 parts by weight, based on 100 parts by weight of the total composition of the present invention, but is not limited thereto.

[0091] The thermoplastic resin composition according to the present invention is environmentally friendly because it utilizes anhydrous sugar alcohol, which is a biomass-derived material, and exhibits excellent long-term heat resistance and optical properties (i.e., high transmittance and low yellowness index) compared to conventional polycarbonate resin compositions, while also exhibiting excellent mechanical properties such as tensile strength and processability, so that a molded article including the same can be suitably used for optical purposes in various industries, and in particular, can be very suitably used as a light guide (more specifically, a light guide for an automobile, and even more specifically, a light guide for an automobile headlamp).

[0092] In one specific example, the thermoplastic resin composition of the present invention can exhibit a transmittance of 91% or more.

[0093] In one specific example, the thermoplastic resin composition of the present invention may exhibit a yellowness index (YI) of less than 1.2.

[0094] In one specific example, the thermoplastic resin composition of the present invention can exhibit a transmittance of 90% or more even after being left at a temperature of 100°C for 1000 hours.

[0095] In one specific example, the thermoplastic resin composition of the present invention can exhibit a yellowness index of less than 1.3 even after being left at a temperature of 100°C for 1000 hours.

[0096] As such, the thermoplastic resin composition of the present invention can exhibit a transmittance of 91% or more and a yellowness index of less than 1.2, and has excellent long-term heat resistance and optical properties to the extent that it can exhibit a transmittance of 90% or more and a YI of less than 1.3 even after a heat resistance test of 1000 hours at a temperature of 100°C.

[0097] Accordingly, according to another aspect of the present invention, a molded article comprising the thermoplastic resin composition of the present invention is provided.

[0098] The above molded product may be an extrusion molded product or an injection molded product of the thermoplastic resin composition of the present invention.

[0099] In a preferred embodiment, the molded article may be a light guide.

[0100] Hereinafter, the present invention will be described in more detail through examples and comparative examples. However, the scope of the present invention is not limited to these examples.

[0101] [Example]

[0102] The ingredients used in the examples and comparative examples are as follows.

[0103] (A) Polycarbonate resin: Samyang Corporation's 3017 PJ

[0104] (B) Polypropylene glycol adduct of isosorbide

[0105] (B-1) PI-1000 (polypropylene glycol molecular weight: 1000 g / mol)

[0106] (B-2) PI-2000 (polypropylene glycol molecular weight: 2000 g / mol)

[0107] (B-3) PI-4000 (polypropylene glycol molecular weight: 4000 g / mol)

[0108] (C) Polybutylene glycol adduct of isosorbide

[0109] (C-1) BI-1000 (polybutylene glycol molecular weight: 1000 g / mol)

[0110] (C-2) BI-2000 (polybutylene glycol molecular weight: 2000 g / mol)

[0111] (C-3) BI-4000 (polybutylene glycol molecular weight: 4000 g / mol)

[0112] (D) Heat stabilizer: Bis(2,4-dicumylphenyl)pentaerythritol diphosphate (S9228PC, Dover)

[0113] (E) Epoxy stabilizer: 7-oxabicyclo[4.1.0]heptan-4-yl 2-(7-oxabicyclo[4.1.0]heptan-4-yl)acetate (2021P)

[0114] (F) polyalkylene glycol

[0115] (F-1) Polypropylene glycol (molecular weight: 2000 g / mol)

[0116] (F-2) Polyethylene glycol (molecular weight: 2000 g / mol)

[0117] (F-3) Polybutylene glycol (molecular weight: 4000 g / mol)

[0118] (G) Phenolic heat stabilizer: Tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane (Song1010, Songwon Industrial)

[0119] The polypropylene glycol adducts of the above isosorbide were manufactured by adding acid-treated isosorbide and propylene oxide in the presence of a KOH catalyst at 100°C to 140°C, cooling and filtering the resultant, and then purifying it using an ion exchange resin. The polybutylene glycol adducts of the above isosorbide were manufactured in the same manner using butylene oxide.

[0120] After preparing a resin composition with the components and contents of each example shown in Table 1 below and each comparative example shown in Table 2 below, it was extruded in a twin-screw melt mixing extruder with L / D=48 and Φ under the 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-feeding speed of 20 kg / h. After cooling the extruded strand in water, it was cut with a rotary cutter to prepare pellets.

[0121] The manufactured pellets were dried with hot air at 80°C to 100°C for 4 hours, and then injection molded at a cylinder temperature of 250°C to 280°C and a mold temperature of 80°C to manufacture specimens. The physical properties of each manufactured specimen were measured using the methods specified below, and the results are shown in Tables 1 and 2 below.

[0122] The physical properties of each manufactured specimen were measured by the following method.

[0123] (1) Tensile strength: Evaluated according to ASTM D638.

[0124] (2) Flexural strength and elastic modulus: Evaluated according to ASTM D790.

[0125] (3) Impact strength: Evaluated according to ASTM D256 (1 / 8 inch thickness, notched-Izod).

[0126] (4) Heat deflection temperature: 18.6 kg / cm according to ASTM D648 2 It was evaluated by the load.

[0127] (5) Melting index: Measured at a temperature of 300℃ and a load of 1.2 kgf according to ASTM D1238.

[0128] (6) Transmittance: Transmittance (%) values ​​were measured using a Gardner i Haze Meter from BYK for square specimens (90 x 80 x 6.4 mm) according to ASTM D1003.

[0129] (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 from X-rite.

[0130] (8) Transmittance after heat resistance test: The transmittance (%) value was measured for the specimen left at a temperature of 100℃ for 1000 hours using the same method as above.

[0131] (9) YI after heat resistance test: The YI value was measured using the same method as above for the specimen left at a temperature of 100℃ for 1000 hours.

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138] As shown in Table 1 above, all of the examples according to the present invention exhibited excellent long-term heat resistance and optical properties (i.e., high transmittance and low yellowness index maintained even after a heat resistance test) compared to conventional polycarbonate resin compositions, while also securing excellently balanced mechanical properties such as processability (high melt index), tensile strength, flexural strength, flexural modulus, and impact strength, making them suitable for use as automotive light guides.

[0139] On the other hand, as shown in Table 2 above, in the case of the comparative examples, the long-term heat resistance and optical properties were inferior to those of the examples (in particular, the transmittance was lowered and the yellowness index was higher after the heat resistance test), and the mechanical properties were also generally poor.

Claims

1. (1) Polycarbonate resin as base resin; (2) Polyalkylene glycol adduct of anhydrous sugar alcohol as a plasticizer component; (3) Heat stabilizer; and (4) Containing an epoxy stabilizer; Thermoplastic resin composition.

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

3. A thermoplastic resin composition in paragraph 1, wherein the anhydrous sugar alcohol in the polyalkylene glycol adduct of the anhydrous sugar alcohol (2) is isosorbide.

4. A thermoplastic resin composition in the first paragraph, wherein the polyalkylene glycol in the polyalkylene glycol adduct of the anhydrous sugar alcohol (2) is polyethylene glycol, polypropylene glycol, polybutylene glycol or a combination thereof.

5. A thermoplastic resin composition comprising, in paragraph 1, a polyalkylene glycol adduct of the anhydrous sugar alcohol (2) in an amount of more than 0.3 parts by weight and less than 5 parts by weight based on 100 parts by weight of the total thermoplastic resin composition.

6. A thermoplastic resin composition, wherein the composition does not contain polyalkylene glycol as an independent component different from the polyalkylene glycol moiety in the polyalkylene glycol adduct of the anhydrous sugar alcohol in the first paragraph, or contains it in an amount of less than 0.5 parts by weight based on 100 parts by weight of the total composition.

7. A thermoplastic resin composition in the first paragraph, wherein the (3) phosphorus heat stabilizer is a pentaerythritol diphosphite heat stabilizer containing four or more benzene rings.

8. A thermoplastic resin composition comprising the (3) phosphorus heat stabilizer in an amount of more than 0.01 parts by weight and less than 5 parts by weight based on 100 parts by weight of the total thermoplastic resin composition.

9. A thermoplastic resin composition in paragraph 1, wherein the (4) epoxy stabilizer is an alicyclic epoxy compound that does not contain an aromatic group.

10. A thermoplastic resin composition comprising the epoxy stabilizer (4) in an amount of more than 0.03 part by weight and less than 1 part by weight based on 100 parts by weight of the total thermoplastic resin composition.

11. A thermoplastic resin composition having a transmittance of 91% or more in the first paragraph.

12. A thermoplastic resin composition having a yellowness index of less than 1.2 in the first paragraph.

13. A thermoplastic resin composition according to claim 1, which exhibits a transmittance of 90% or more even after being left at a temperature of 100°C for 1,000 hours.

14. A thermoplastic resin composition according to claim 1, which exhibits a yellowness index of less than 1.3 even after being left at a temperature of 100°C for 1,000 hours.

15. A molded product comprising a thermoplastic resin composition according to any one of claims 1 to 14.

16. A molded product which is a light guide in Article 15.

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