Polycarbonate resin composition containing benzotriazole polymer

Abstract

To provide a polycarbonate resin composition exhibiting heat resistance while ensuring superior compatibility with polycarbonate resin.SOLUTION: A benzotriazole-based polymer comprises at least one chemical structure in which the following benzotriazole derivative structure and bisphenol derivative structure are linked through a carbonyl group, as its constitutional unit.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a novel benzotriazole-based polymer, and further to an ultraviolet absorber using the benzotriazole-based polymer, and a polycarbonate resin composition containing the benzotriazole-based polymer. [Background technology]

[0002] Polycarbonate resin is a material with excellent transparency, impact resistance, heat resistance, and flame retardancy, and is used in various fields such as automobile parts, building materials, electronic devices, medical instruments, eyeglass lenses, and films. Polycarbonate resin is deteriorated by the action of ultraviolet rays from natural light, resulting in a decrease in performance and discoloration. In order to prevent such deterioration due to ultraviolet rays, various ultraviolet absorbents have been added and used during the processing of the resin. As the ultraviolet absorbents used for polycarbonate resin, for example, various organic compounds such as benzophenone, benzotriazole, and triazine are known.

[0003] However, the ultraviolet absorbents commonly used in polycarbonate resins volatilize and decompose themselves at high temperatures during resin processing, resulting in problems such as contamination of resin molding dies due to volatilization of the ultraviolet absorbent during resin processing and discoloration of the resin due to thermal decomposition of the ultraviolet absorbent.

[0004] In order to solve these problems during processing of polycarbonate resin, Patent Documents 1 and 2 propose ultraviolet absorbers in which two benzotriazole compounds are linked with a methylene group to dimerize them, thereby increasing the molecular weight and improving heat resistance. However, due to the effect of dimerization, the absorption spectrum of these ultraviolet absorbers becomes longer in wavelength and absorbs visible light, so when these are added to polycarbonate resin, the polycarbonate resin takes on a yellowish tinge, limiting the uses.

[0005] In addition, Patent Document 3 proposes an ultraviolet absorber having improved heat resistance by increasing the molecular weight through the addition of a bulky substituent to a benzotriazole compound. However, when the present inventors evaluated the heat resistance of the ultraviolet absorber described in Patent Document 3, they found that although it was improved compared to general ultraviolet absorbers, it could not be said that it exhibited sufficient heat resistance, and there were problems such as contamination of a resin molding die and coloring of the resin due to thermal decomposition.

[0006] Patent Documents 4 and 5 propose a polymeric ultraviolet absorber obtained by copolymerizing a benzotriazole derivative containing a (meth)acryloyl group with a (meth)acrylic acid ester, and propose that by incorporating an ultraviolet absorbing structure as a component of the polymer, it is possible to prevent the volatilization and decomposition of the ultraviolet absorbing component at high temperatures during processing, and the bleed-out of the ultraviolet absorbing component after processing.

[0007] The polymeric ultraviolet absorbents described in these documents are used in contact lenses, films, coatings, etc. However, the polymeric ultraviolet absorbents in all of these documents are molded or formed into films by themselves, so their compatibility with other resins is considered to be insufficient. For this reason, it is difficult to use these polymeric ultraviolet absorbents by adding them to polycarbonate resin. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 61-118373 [Patent Document 2] Japanese Patent Publication No. 61-118374 [Patent Document 3] Japanese Patent Publication No. 51-21587 [Patent Document 4] Japanese Patent Publication No. 60-38411 [Patent Document 5] Patent Publication No. 2012-25811 Summary of the Invention [Problem to be solved by the invention]

[0009] Under these circumstances, an object of the present invention is to synthesize a novel benzotriazole-based polymer and to provide a polycarbonate resin composition using the same, which contains an ultraviolet absorber that has heat resistance and excellent compatibility with polycarbonate resins. [Means for solving the problem]

[0010] The most important feature of the polycarbonate resin composition of the present invention is that a benzotriazole-based polymer containing, as a constituent unit, one or more chemical structures in which a benzotriazole derivative structure represented by the following general formula (1) and a bisphenol derivative structure represented by the following general formula (2) are linked via a carbonyl group is blended with a polycarbonate resin.

[0011] [ka] General formula (1)

[0012] [ka] General formula (2) Effect of the Invention

[0013] The benzotriazole-based polymer constituting the polycarbonate resin composition of the present invention is less susceptible to volatilization and decomposition even at high temperatures and has high compatibility with polycarbonate resins, so that bleeding out is less likely to occur. [Brief description of the drawings]

[0014] [Figure 1] This is the 1H-NMR spectrum of polymer (a). [Diagram 2] 1 is an ultraviolet to visible absorption spectrum of polymer (a). [Diagram 3] This is the 1H-NMR spectrum of the polymer (b). [Figure 4]This is an ultraviolet to visible absorption spectrum of the polymer (b). BEST MODE FOR CARRYING OUT THEINVENTION

[0015] (Benzotriazole-based polymers) The present invention will be described in detail below. The benzotriazole-based polymer constituting the polycarbonate resin composition of the present invention is a polymer containing, as a constituent unit, at least one chemical structure in which a benzotriazole derivative structure represented by the above general formula (1) and a bisphenol derivative structure represented by the above general formula (2) are linked via a carbonyl group.

[0016] The benzotriazole derivative compound of the present invention, represented by formula (1), will be described in more detail below.

[0017] [ka] General formula (1)

[0018] The benzotriazole derivative structure represented by the above general formula (1), which constitutes the benzotriazole-based polymer of the present invention, is obtained from compound (a) represented by the following [Chemical Formula 3]; 5-hydroxy-2-(2,4-dihydroxyphenyl)-2H-benzotriazole.

[0019] [ka] compound (a)

[0020] The method for synthesizing compound (a) is not particularly limited, and a wide variety of conventionally known reaction principles can be used. For example, compound (a) can be synthesized via the reaction formulae shown in Chemical Formulas 4 to 8 below. [ka] [ka] [ka] [ka] [ka]

[0021] The bisphenol derivative structure represented by the general formula (2) constituting the present invention will be described in more detail below. [ka] General formula (2)

[0022] (Synthesis method 1) The benzotriazole-based polymer of the present invention can be synthesized by an ester exchange reaction using the compound (a) represented by the above [Chemical formula 3] and a polycarbonate, which is a polymer having a bisphenol derivative structure represented by [Chemical formula 2].

[0023] The polycarbonate may be a general polycarbonate using 2,2-bis(4-hydroxyphenyl)propane. In addition, it is also possible to add special polycarbonates using 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, etc. together with 2,2-bis(4-hydroxyphenyl)propane to form a polycarbonate copolymer using two or more kinds of bisphenol derivative compounds.

[0024] The method for synthesizing the benzotriazole-based polymer of the present invention by transesterification using polycarbonate is not particularly limited, and any conventionally known method can be used.

[0025] In the transesterification reaction using polycarbonate, the following catalysts can be used: inorganic acids such as hydrochloric acid, sulfuric acid, and hydrobromic acid; organic acids such as trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; bases such as sodium methoxide, sodium ethoxide, and 4-dimethylaminopyridine; Lewis acids such as aluminum trichloride, aluminum ethoxide, aluminum isopropoxide, boron trifluoride, boron trichloride, zinc chloride, zinc bromide, zinc iodide, titanium tetrachloride, titanium tetrabromide, titanium (IV) methoxide, titanium (IV) ethoxide, and titanium (IV) isopropoxide. These catalysts may be used alone or in combination as necessary. The amount of the catalyst used is preferably 0.001 to 1.0 mol, more preferably 0.005 to 0.25 mol, per mol of the compound (a) used.

[0026] In the transesterification reaction using polycarbonate, the reaction may be carried out without a solvent, but a solvent may be used. Examples of solvents that can be used include the following: aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as pentane, hexane, heptane, octane, nonane, decane, cyclohexane, and cyclooctane; halogenated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, carbon tetrachloride, chlorobenzene, and trifluoromethylbenzene; ethers such as diethyl ether, diisopropyl ether, dibutyl ether, anisole, tetrahydrofuran, and dioxane; ketones such as methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone; nitriles such as acetonitrile, amides such as dimethylformamide and N-methylpyrrolidone; sulfoxides such as dimethyl sulfoxide, and the like. These solvents may be used alone or in combination as necessary.

[0027] When the transesterification reaction using polycarbonate is carried out without a solvent, the reaction temperature is preferably in the range of 100 to 350° C., more preferably in the range of 150 to 300° C. Depending on the reaction temperature and the type of raw materials used, the reaction may be carried out under reduced pressure. The reaction time may be appropriately set depending on the reaction temperature and the type of raw materials used so that the reaction is completed.

[0028] When the transesterification reaction using polycarbonate is carried out in a solvent, the reaction temperature is preferably in the range of room temperature to 200° C., more preferably in the range of 100 to 200° C. Depending on the reaction temperature, the type of solvent and raw materials used, etc., the reaction may be carried out under reduced pressure. The reaction time may be appropriately set depending on the reaction temperature, the type of solvent and raw materials used, etc., so that the reaction is completed.

[0029] (Synthesis method 2) The benzotriazole-based polymer constituting the polycarbonate resin composition of the present invention can also be synthesized by a polymerization reaction of the compound (a) represented by the above [Chemical formula 3], a compound having a bisphenol derivative structure represented by the above [Chemical formula 2], and a compound having a carbonyl group.

[0030] An example of a compound having a bisphenol derivative structure represented by Chemical Formula 2, which is used in the polymerization reaction, is 2,2-bis(4-hydroxyphenyl)propane. In addition to 2,2-bis(4-hydroxyphenyl)propane, two or more kinds of bisphenol derivative compounds, such as 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, and 2,2-bis(4-hydroxyphenyl)-4-methylpentane, may be used.

[0031] Examples of compounds having a carbonyl group that can be used in the polymerization reaction include carbonates such as dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and diphenyl carbonate; and phosgenes such as phosgene and triphosgene.

[0032] The method for synthesizing the benzotriazole-based polymer of the present invention by polymerization reaction is not particularly limited, and any conventionally known method for synthesizing polycarbonates can be widely used. For example, a polymerization reaction by ester exchange using carbonates or a polycondensation reaction using phosgenes can be used.

[0033] The polymerization reaction by transesterification using the carbonates can be carried out by the same means as the transesterification reaction using polycarbonate shown in the synthesis method 1 above.

[0034] In the polycondensation reaction using the phosgenes, specifically, a method can be used in which a mixture of the compound (a) represented by the above [Chemical formula 3], a compound having a bisphenol derivative structure represented by the above [Chemical formula 2], alkaline water, and a water-insoluble organic solvent is reacted with the phosgenes.

[0035] Examples of the alkali that can be used in the polycondensation reaction using the phosgenes include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide.

[0036] Examples of the non-water-soluble organic solvent used in the polycondensation reaction using the phosgenes include chlorine-based organic solvents such as dichloromethane, dichloroethane, chloroform, chlorobenzene, and carbon tetrachloride.

[0037] The benzotriazole derivative structure represented by the above general formula (1) contained in the benzotriazole-based polymer of the present invention is preferably contained in an amount of 0.1 to 50% by weight, and more preferably in an amount of 0.2 to 25% by weight.

[0038] (Other components) The benzotriazole-based polymer of the present invention may contain a benzotriazole derivative structure represented by the following general formula (3).

[0039] [ka] General formula (3)

[0040] In general formula (3), R 5 represents a hydrogen atom; a chlorine atom; a linear or branched alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a hexyl group, an octyl group, or a 2-ethylhexyl group; or a linear or branched alkoxy group having 1 to 8 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a hexyloxy group, an octyloxy group, or a 2-ethylhexyloxy group.

[0041] When synthesizing a benzotriazole-based polymer containing the above general formula (3), a reaction is carried out using a benzotriazole derivative compound having a hydroxyl group at the 4-position of the phenyl group. Examples of the benzotriazole derivative compound having a hydroxyl group at the 4-position of the phenyl group include the following. 2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 5-chloro-2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 2-(2,4-dihydroxyphenyl)-5-methyl-2H-benzotriazole, 5-ethyl-2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 2-(2,4-dihydroxyphenyl)-5-octyl-2H-benzotriazole, 2-(2,4-dihydroxyphenyl)-5-methoxy-2H-benzotriazole, 5-ethoxy-2-(2,4-dihydroxyphenyl)-2H-benzotriazole, 2-(2,4-dihydroxyphenyl)-5-octyloxy-2H-benzotriazole, etc. These benzotriazole derivative compounds having a hydroxy group at the 4-position of the phenyl group may be used alone or in combination as required.

[0042] When the benzotriazole-based polymer of the present invention contains a benzotriazole derivative structure represented by the above general formula (3), it is preferably contained in an amount of 0.1 to 10% by weight, and more preferably in an amount of 0.2 to 5% by weight.

[0043] (Polycarbonate resin composition) Examples of polycarbonate resin materials to which the benzotriazole polymer of the present invention can be added include the following: general polycarbonates using 2,2-bis(4-hydroxyphenyl)propane; special polycarbonates using 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, etc.; polycarbonate copolymers using two or more of the above bisphenol derivative compounds, etc.

[0044] When the benzotriazole-based polymer of the present invention is added to a polycarbonate resin material, the benzotriazole-based polymer alone can be used as an ultraviolet absorbent, but the benzotriazole-based polymer can also be used in combination with other ultraviolet absorbents. The ultraviolet absorbent other than the benzotriazole-based polymer is not particularly limited as long as it is generally available on the market and can absorb ultraviolet light. For example, benzophenone-based, benzotriazole-based or triazine-based compounds can be used. These ultraviolet absorbents may be used alone or in a suitable mixture of two or more.

[0045] When the benzotriazole-based polymer of the present invention is added to a polycarbonate resin material, the benzotriazole derivative structure represented by the above general formula (1) contained in the benzotriazole-based polymer of the present invention is preferably contained in an amount of 0.01 to 20% by weight, and more preferably 0.1 to 5% by weight, based on the polycarbonate resin composition. EXAMPLES

[0046] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these embodiments. (Intermediate Synthesis Example 1) [Synthesis of compound (a); 5-hydroxy-2-(2,4-dihydroxyphenyl)-2H-benzotriazole] [ka] compound (a)

[0047] A 2000ml four-neck flask was fitted with a ball condenser, a thermometer and a stirrer, 200g (1.189 mol) of 4-methoxy-2-nitroaniline, 550ml of water and 329g (2.097 mol) of 62.5% sulfuric acid were mixed, 236g (1.231 mol) of 36% aqueous sodium nitrite solution was added dropwise at 5-11°C, and the mixture was stirred at the same temperature for 2 hours to obtain an aqueous diazonium salt solution. A 5000ml four-neck flask was fitted with a ball condenser, a thermometer and a stirrer, 137.8g (1.251 mol) of resorcinol, 1800ml of isopropyl alcohol and 760ml of water were dissolved, and the aqueous diazonium salt solution was added dropwise at 5-10°C and stirred at the same temperature for 15 hours. The mixture was adjusted to pH 4 by adding 396 g of 32% aqueous sodium hydroxide solution, and then allowed to stand at 60°C to remove the lower aqueous layer by liquid separation to obtain a slurry of 4-(4-methoxy-2-nitrophenylazo)resorcinol. Next, 350 g (2.800 mol) of 32% aqueous sodium hydroxide solution and 1.78 g (0.0162 mol) of hydroquinone were added, and 71.1 g (0.852 mol) of 60% hydrazine monohydrate was added dropwise at 45-50°C over 30 minutes, followed by stirring at 40-50°C for 3 hours. 245 g of 62.5% sulfuric acid was added to adjust the pH to 6, 500 ml of water was added, the mixture was allowed to stand at 60°C, the lower aqueous layer was removed by separation, 100 ml of isopropyl alcohol and 100 ml of water were added, and the mixture was cooled to 20°C. The precipitated crystals were filtered, washed with 200 ml of isopropyl alcohol and 300 ml of water, and dried to obtain 312.7 g of 2-(2,4-dihydroxyphenyl)-5-methoxy-2H-benzotriazole N-oxide.

[0048] A 2000 ml four-neck flask was equipped with a ball condenser, a thermometer, and a stirrer, and 281.5 g (1.030 mol) of 2-(2,4-dihydroxyphenyl)-5-methoxy-2H-benzotriazole N-oxide, 740 ml of methyl isobutyl ketone, 360 ml of water, and 91.6 g (1.400 mol) of zinc powder were added thereto. 250.7 g (1.598 mol) of 62.5% sulfuric acid was added dropwise at 40°C, and the mixture was stirred at 73 to 90°C for 4 hours. The mixture was then allowed to stand, the lower aqueous layer was separated and removed, 130 ml of water was added, the mixture was allowed to stand at 70°C, and the lower aqueous layer was removed by separation. This process was repeated twice, and the solvent was recovered under reduced pressure, after which 350 ml of toluene was added. The resulting precipitate was filtered at 7°C, washed with 120 ml of toluene, and dried to obtain 193.6 g of 2-(2,4-dihydroxyphenyl)-5-methoxy-2H-benzotriazole.

[0049] A 2000ml four-neck flask was equipped with a ball condenser, a thermometer, and a stirrer, and 190.0g (0.739 mol) of 2-(2,4-dihydroxyphenyl)-5-methoxy-2H-benzotriazole, 1000ml of acetic acid, 97ml of water, and 119.7g (0.763 mol) of 95% sulfuric acid were added, and the mixture was stirred at 105-110°C for 28 hours. The mixture was then cooled to 10°C, and the precipitated crystals were filtered, washed with 400ml of water, and dried to obtain 162.3g of crude crystals of compound (a). 140.0g (0.576 mol) of crude crystals of compound (a) were recrystallized with methyl isobutyl ketone to obtain 126.2g (0.519 mol) of compound (a). The yield was 60% (from 4-methoxy-2-nitroaniline). Melting point: 261°C.

[0050] In addition, the purity of compound (a) was measured by HPLC analysis. <Measurement conditions> Equipment: Chromaster-5110 (Hitachi High-Technologies Corporation) Column: SUMIPAX ODS A-212 6 x 150 mm 5 μm Column temperature: 40℃ Mobile phase: Methanol / water = 95 / 5 (phosphoric acid 3ml / L) Flow rate: 1.0ml / min <Measurement results> HPLC surface purity: 99.0%

[0051] Furthermore, when the ultraviolet to visible absorption spectrum of the compound (a) was measured, the maximum absorption wavelength λmax was 350 nm, and the molar absorption coefficient ε at this time was 23500. The conditions for measuring the spectrum were as follows. <Measurement conditions> Equipment: UV-1850 (Shimadzu Corporation) Measurement wavelength: 250~450nm Solvent: Methanol Concentration: 10ppm Cell: 1cm quartz

[0052] In addition, NMR analysis of compound (a) was performed, and the results supported the above structure. The measurement conditions were as follows: <Measurement conditions> Equipment: ECX-500II (manufactured by JEOL Ltd.) Resonance frequency: 500MHz (1H-NMR) Solvent: Dimethylsulfoxide - d6 Tetramethylsilane was used as the internal standard for 1H-NMR, and the chemical shift value was expressed in δ (ppm), and the coupling constant was expressed in Hertz. s stands for singlet, and d stands for doublet. The contents of the obtained 1H-NMR spectrum are as follows. δ=10.5(s,1H,OH),10.0(s,1H,OH),9.95(s,1H,OH),7.82(d,1H,J=9.0Hz,benzotriazole-H),7.61(d,1H,J=9.0Hz,benzotriazole-H), 7.08(d,1H,J=10.0Hz,resorcinol-H),7.06(s,1H,benzotriazole-H),6.50(s,1H,resorcinol-H),6.41(d,1H,J=9.5Hz,resorcinol-H)

[0053] Example 1 [Polymer (a); Polymer obtained by transesterification of compound (a) with general polycarbonate] [ka] Polymer (a)

[0054] In a 200 ml eggplant flask, 4.99 g (19.6 mmol / repeating unit equivalent) of polycarbonate (TARFLON IR2200 manufactured by FORMOSA IDEMITSU PETROCHEMICAL CORPORATION), 1.91 g (7.86 mmol) of compound (a), and 0.0165 g (0.14 mmol) of 4-aminodimethylpyridine were added, and a Liebig condenser was attached, and the mixture was stirred at 210 to 280 ° C for 4 hours under a reduced pressure of 0.4 to 1.0 torr. The mixture was cooled to room temperature, 50 ml of chloroform was added, and the mixture was filtered to obtain a chloroform solution of polymer (a). A stir bar and 500 ml of methanol were added to a 1000 ml beaker, and the chloroform solution was dropped to perform reprecipitation, and the precipitated crystals were filtered and dried in vacuum to obtain 6.25 g of polymer (a).

[0055] The molecular weight of the polymer (a) was measured, and the weight average molecular weight (Mw) was 8560, the number average molecular weight (Mn) was 2270, and the polydispersity (Mw / Mn) was 3.77. The measurement conditions were as follows: <Measurement conditions> Equipment: LC-10AD (Shimadzu Corporation) Eluent: Chloroform Columns: Shodex K-807L, Shodex K805L, Shodex K-804L (Showa Denko Co., Ltd.)

[0056] Furthermore, NMR analysis of polymer (a) was performed, and the results supported the above structure. The spectrum is shown in Figure 1. The measurement conditions were as follows: <Measurement conditions> Equipment: ECX-500II (manufactured by JEOL Ltd.) Resonance frequency: 500MHz (1H-NMR) Solvent: Chloroform-d The 1H-NMR spectrum of the following polymer (b) was also measured under the same measurement conditions as those for the polymer (a).

[0057] The content of the ultraviolet absorbing component derived from the compound (a) contained in the polymer (a) was measured by the absorbance at the maximum absorption wavelength in the ultraviolet to visible absorption spectrum. The measurement conditions were as follows. <Measurement conditions> Equipment: U-3900H (Hitachi High-Technologies Corporation) Solvent: Tetrahydrofuran (compound (a)), chloroform (polymer (a)) Concentration: 5ppm (compound (a)), 5ppm (polymer (a)) Cell: 1cm quartz <Measurement results> Content: 16wt%

[0058] The maximum absorption wavelength λmax of the polymer (a) was 339 nm. The spectrum is shown in Figure 2. The conditions for measuring the spectrum are as follows: <Measurement conditions> Equipment: UV-1850 (Shimadzu Corporation) Measurement wavelength: 250~450nm Solvent: Chloroform UV absorbing component concentration: 10ppm Cell: 1cm quartz The ultraviolet to visible absorption spectrum of the following polymer (b) was also measured under the same measurement conditions as those for the polymer (a).

[0059] (Reference example) [Polymer (b); Polymer obtained by copolymerization of compound (a) with 2,2-bis(4-hydroxy-3-methylphenyl)propane and diphenyl carbonate] [ka] Polymer (b)

[0060] In a 200 ml eggplant flask, 3.08 g (12.0 mmol) of 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2.70 g (0.0126 mmol), 0.584 g (2.40 mmol) of compound (a), and 0.0730 g (6.00 mmol) of 4-aminodimethylpyridine were added, and a rotor was inserted and a Liebig condenser was attached, and the mixture was stirred at 210 to 270 ° C for 3 hours under a reduced pressure of 17 to 20 torr. The mixture was cooled to room temperature, 60 ml of chloroform was added, and the mixture was filtered to obtain a chloroform solution of polymer (b). A thermometer and a stirrer were attached to a 500 ml four-neck flask, 350 ml of methanol was added, and the chloroform solution was dropped over 30 minutes to perform reprecipitation, and the precipitated crystals were filtered at 20 ° C, washed with 40 ml of methanol, and dried to obtain 2.62 g of polymer (b).

[0061] The molecular weight of the polymer (b) was measured, and as a result, the weight average molecular weight (Mw) was 10270, the number average molecular weight (Mn) was 5800, and the polydispersity (Mw / Mn) was 1.77. The measurement conditions were as follows: <Measurement conditions> Equipment: LC-20AD (Shimadzu Corporation) Eluent: Chloroform Column: Shodex KF-804L (Showa Denko Co., Ltd.)

[0062] Furthermore, NMR analysis of polymer (b) provided results supporting the above structure. The spectrum is shown in Figure 3.

[0063] The content of the ultraviolet absorbing component derived from the compound (a) contained in the polymer (b) was measured by the absorbance at the maximum absorption wavelength in the ultraviolet to visible absorption spectrum under the following measurement conditions. <Measurement conditions> Equipment: UV-1850 (Shimadzu Corporation) Measurement wavelength: 250~450nm Solvent: Tetrahydrofuran Concentration: 5ppm (compound (a)), 10ppm (polymer (b)), Cell: 1cm quartz <Measurement results> Content: 10wt%

[0064] The maximum absorption wavelength λmax of the polymer (b) was 341 nm. The spectrum is shown in FIG.

[0065] [Heat resistance measurement] The heat resistance of the polymers (a) and (b) obtained in Example 1 and Reference Example, and, as comparative examples, compound (b), a conventional UV absorber for polycarbonate; 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole, and compound (c), a conventional highly heat-resistant UV absorber for polycarbonate; 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidylmethyl)phenol, were measured using a simultaneous differential thermal and thermogravimetric analyzer. The results are shown in Table 1.

[0066] [Table 1]

[0067] [Preparation of polycarbonate resin composition] The polymers (a) and (b) obtained in Example 1 and Reference Example, and the compounds (b) and (c) of Comparative Example were mixed with various polycarbonate resin materials and dichloromethane in the ratios shown in Table 2 to obtain a solution of a polycarbonate resin composition containing an ultraviolet absorber. 20 ml of the obtained solution of the polycarbonate resin composition containing an ultraviolet absorber was transferred to a petri dish with a diameter of 12 cm, and the solvent was removed by drying at 25°C under normal pressure for 48 hours to obtain a polycarbonate resin composition having a film thickness of 0.05 mm and containing 1 wt% of an ultraviolet absorbing component. As the polycarbonate resin material, a polymer using a general polycarbonate (a): TARFLON IR2200 manufactured by FORMOSA IDEMITSU PETROCHEMICAL CORPORATION, and a special polycarbonate (a): 2,2-bis(4-hydroxy-3-methylphenyl)propane was used.

[0068] [Table 2]

[0069] [Gloss measurement] The gloss of the surface of the polycarbonate resin composition containing 1 wt% of the ultraviolet absorbing component obtained above is shown in Table 3. If the compatibility between the polycarbonate resin material and the ultraviolet absorber is insufficient, the ultraviolet absorber will bleed out onto the surface of the polycarbonate resin composition, causing the surface of the polycarbonate resin composition to become rough and the gloss to decrease. Therefore, the gloss is an index of the compatibility between the polycarbonate resin material and the ultraviolet absorber.

[0070] [Table 3]

[0071] From Table 1, it can be seen that the benzotriazole-based polymers (a) and (b) have a high 5% weight loss temperature and high heat resistance that is less likely to volatilize or decompose at high temperatures compared to the compounds (b) and (c) that are conventional ultraviolet absorbers used in polycarbonate. Also, from Table 3, it can be seen that the polycarbonate resin composition containing the polymers (a) and (b) has excellent gloss compared to the polycarbonate resin composition containing the compounds (b) and (c) that are conventional ultraviolet absorbers used in polycarbonate, and therefore has high compatibility with polycarbonate resin materials and is less likely to bleed out, making it a useful polycarbonate resin composition. The measurement conditions for heat resistance and gloss are as follows.

[0072] <Heat resistance measurement conditions> Equipment: TG / DTA STA7200RV (Hitachi High-Technologies Corporation) Measurement temperature: 50~500℃ Heating rate: 10℃ / min Measurement atmosphere: Nitrogen

[0073] <Glossiness measurement conditions> Equipment: UNI GLOSS60 (Konica Minolta Sensing, Inc.) Measurement angle: 60° [Industrial Applicability]

[0074] The benzotriazole-based polymer constituting the polycarbonate resin composition of the present invention has high heat resistance, and therefore does not volatilize or decompose in the processing step of the polymer containing an ultraviolet absorbing component. Furthermore, since the compatibility between the polycarbonate resin material and the polymer is high, bleeding out is unlikely to occur, and therefore the benzotriazole-based polymer can be suitably used as an ultraviolet absorber for polycarbonate resin.

Claims

[Claim 1] A polycarbonate resin composition comprising a benzotriazole-based polymer containing, as a constituent unit, at least one chemical structure in which a benzotriazole derivative structure represented by the following general formula (1) and a bisphenol derivative structure represented by the following general formula (2) are linked via a carbonyl group, and the benzotriazole-based polymer is blended with another polycarbonate resin. 【Chemistry 1】 General formula (1) 【Chemistry 2】 General formula (2)

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