Polycarbonate resin composition, molded article, lens and film

Abstract

To provide a polycarbonate resin composition which has high total light transmittance, low photoelastic coefficient, and is excellent in heat resistance and low moisture absorption.SOLUTION: A polycarbonate resin composition is provided, including: a polycarbonate resin including a structural unit (A) derived from a predetermined dihydroxy compound; and an aromatic polycarbonate resin including a predetermined structural unit (B).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polycarbonate resin composition, a molded article, a lens, and a film.

[0002] A method for obtaining polycarbonate resins using isosorbide (hereinafter sometimes abbreviated as ISB) obtained from biomass resources as a monomer component has been proposed and disclosed for use in optical films (see, for example, Patent Document 1). Meanwhile, aromatic polycarbonate resins using 2,2-bis(4-hydroxyphenyl)propane (hereinafter sometimes abbreviated as bisphenol A) as a monomer component are widely used in various fields, such as automotive parts, medical parts, and building materials, taking advantage of their transparency and mechanical strength. Resins with excellent transparency have also been disclosed in some compositions by blending these components (see, for example, Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 171194 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-21171 [Patent Document 3] International Publication No. 2011 / 071162 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as disclosed in Patent Document 1, ISB-containing polycarbonate resins contain many oxygen atoms and are more polar than polycarbonate resins obtained from diols that do not contain ether moieties, such as aromatic bisphenol-containing polycarbonate resins. Therefore, ISB-containing polycarbonate resins have the disadvantage of being more water-absorbent than aromatic bisphenol-containing polycarbonate resins, which can lead to a decrease in the dimensional stability of molded articles and films due to water absorption and a decrease in heat resistance under humid conditions. On the other hand, reducing the ISB content reduces water absorption, but also reduces heat resistance, resulting in molded articles deforming and being unable to maintain their intended shape under high-temperature conditions.

[0005] As disclosed in Patent Document 2 or Patent Document 3, a composition of a polycarbonate resin containing only bisphenol A as the diol monomer component and an ISB-containing polycarbonate resin has a high photoelastic coefficient and is therefore unsuitable for use in optical applications.

[0006] The present invention is intended to solve the above problems and provides a polycarbonate resin composition that solves these problems.

[0007] Means for Solving the Problems The present inventors have conducted extensive research to solve the above problems, and as a result have found that a polycarbonate resin composition containing a polycarbonate resin having specific structural units and an aromatic polycarbonate resin having specific structural units has high transparency, excellent optical properties, heat resistance, and low moisture absorption, and have arrived at the present invention as described below.

[0008] That is, the gist of the present invention lies in the following [1] to

[17] .

[0009] [1] A polycarbonate resin containing a structural unit (A) derived from a dihydroxy compound having a moiety represented by the following formula (1): and an aromatic polycarbonate resin containing a structural unit (B) represented by the following formula (2):

[0010] [ka]

[0011] (However, this does not include the case where the moiety represented by the above formula (1) is part of —CH—OH.)

[0012] [ka]

[0013] (However, R in the above formula (2) 1 ~R 8 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, and X represents a direct bond, a substituted or unsubstituted chain alkylene group having 1 to 20 carbon atoms other than -C(CH3)2-, a substituted or unsubstituted cyclic alkylene group having 6 to 20 carbon atoms, or an arylene group having 6 to 20 carbon atoms other than a fluorene skeleton.

[0014] [2] The polycarbonate resin composition according to [1], wherein the structural unit (A) is a structural unit represented by the following formula (3):

[0015] [ka]

[0016] [3] The polycarbonate resin composition according to [1] or [2], wherein the structural unit (B) is a structural unit represented by the following formula (4):

[0017] [ka]

[0018] [4] The polycarbonate resin composition according to any one of [1] to [3], wherein the polycarbonate resin composition has one glass transition temperature. [5] The polycarbonate resin composition according to any one of [1] to [4], which contains an ultraviolet absorber in an amount of 0.01 to 3.0% by mass.

[0019] [6] The polycarbonate resin composition according to any one of [1] to [5], which has a reduced viscosity at 20°C of 0.30 or more and 0.53 or less. [7] A molded article obtained by molding the polycarbonate resin composition according to any one of [1] to [6].

[0020] [8] The molded article according to [7], having a total light transmittance of 85% or more. [9] The molded article according to [7] or [8], which has a light transmittance of 95% or less at a wavelength of 380 nm.

[0021]

[10] Photoelastic coefficient is 60 -12 Pa -1 The molded article according to any one of [7] to [9] below.

[11] A lens obtained by molding the polycarbonate resin composition according to any one of [1] to [6].

[0022]

[12] A film obtained by molding the polycarbonate resin composition according to any one of [1] to [6].

[13] An optical film comprising the film according to

[12] .

[0023]

[14] A protective film comprising the film according to

[12] .

[15] A retardation film comprising the film according to

[12] .

[0024]

[16] The retardation film according to

[15] , wherein the in-plane retardation Re(550) is 100 nm to 600 nm.

[17] The retardation film according to

[15] or

[16] , wherein the ratio of the retardation R450 measured at a wavelength of 450 nm to the retardation R550 measured at a wavelength of 550 nm satisfies the following formula (I): 0.98≦R450 / R550≦1.05 (I) [Effects of the Invention]

[0025] According to the present invention, by preparing a polycarbonate resin composition containing a polycarbonate resin having a specific structural unit (A) and an aromatic polycarbonate resin having a specific structural unit (B), it is possible to provide a polycarbonate resin composition that has high total light transmittance, a low photoelastic coefficient, excellent heat resistance, and low moisture absorption. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will be described in detail below, but the present invention is not limited to the following description and can be practiced with any modifications within the scope of the gist of the present invention. In this specification, when "to" is used with a numerical value or physical property value between the two sides, the values ​​before and after the "to" are used to include the values ​​before and after the "to." Furthermore, numerical values ​​or physical values ​​described as upper and lower limits, other than those described as "greater than" or "less than," are used to include the values. Furthermore, unless otherwise specified, "%" means "% by mass." Furthermore, "parts by weight" and "parts by mass," and "% by weight" and "% by mass" are essentially synonymous.

[0027] In the present disclosure, the term "polycarbonate resin" refers to a polymer in which the structural units constituting the polymer include not only carbonate bonds but also moieties linked by ester bonds.

[0028] The term "structural unit" refers to a partial structure constituting a resin, and refers to a specific partial structure contained in a repeating structural unit. For example, in the case of a polycarbonate resin, it refers to a partial structure sandwiched between adjacent linking groups in the resin, or a partial structure sandwiched between a polymerization reactive group present at the terminal portion of a polymer and a linking group adjacent to the polymerization reactive group. More specifically, in the case of a polycarbonate resin, a carbonyl group is the linking group, and a partial structure sandwiched between adjacent carbonyl groups is referred to as a structural unit. In this specification, the mass ratio of each structural unit in the resin is calculated assuming that the total mass of all structural units and linking groups is 100 mass %.

[0029] The following describes in detail the embodiments of the present invention. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to the following content as long as it does not exceed the gist of the present invention.

[0030] [Polycarbonate resin composition] The polycarbonate resin composition of the present invention is a polycarbonate resin composition containing a polycarbonate resin containing a specific structural unit (A) and an aromatic polycarbonate resin containing a specific structural unit (B).

[0031] Hereinafter, a polycarbonate resin containing the specific structural unit (A) may be abbreviated as a "polycarbonate resin," and an aromatic polycarbonate resin containing the specific structural unit (B) may be abbreviated as an "aromatic polycarbonate resin."

[0032] <Polycarbonate resin> The polycarbonate resin in the present invention is a polycarbonate resin containing a structural unit (A) derived from a dihydroxy compound having at least one moiety represented by the following formula (1).

[0033] [ka] (However, this does not include the case where the moiety represented by the above formula (1) is part of -CH2-OH.)

[0034] Dihydroxy compounds having a moiety represented by formula (1) include isosorbide (ISB), isomannide, and isoidet, which are stereoisomers. These may be used alone or in combination of two or more. Among these, isosorbide, which is obtained by dehydration condensation of sorbitol, which is produced from various starches that are abundant and easily available as plant-derived resources, is most preferred in terms of availability, ease of production, and the properties of the resulting molded products (e.g., heat resistance, impact resistance, surface hardness). Furthermore, isosorbide is preferably used from the viewpoint of carbon neutrality.

[0035] The structural unit (A) is preferably a structural unit represented by the following formula (3).

[0036] [ka]

[0037] The mass ratio of the structural unit (A) in the polycarbonate resin is preferably 5% by mass or more, more preferably 15% by mass or more, and even more preferably 25% by mass or more, based on 100% by mass of all structural units constituting the polycarbonate resin. At or above the lower limit, the solidification temperature of the resulting polycarbonate resin can be set to room temperature or higher, preventing fusion of the pellets when the polycarbonate resin is pelletized and handled. Furthermore, the mass ratio of the structural unit (A) is preferably 95% by mass or less, more preferably 75% by mass or less, and even more preferably 55% by mass or less. At or below the upper limit, the water absorption rate of the polycarbonate resin can be suppressed, improving compatibility with aromatic polycarbonate resins containing the structural unit (B) represented by the above formula (2).

[0038] Furthermore, examples of dihydroxy compounds having a moiety represented by the formula (1) include spiroglycol (also known as 3,9-bis(1,1-dimethyl-2-hydroxyethyl-2,4,8,10-tetraoxaspiro[5,5]undecane) and dioxane glycol (also known as 2-(1,1-dimethyl-2-hydroxyethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane). Of these, spiroglycol is more preferred. Furthermore, the structural unit (A) derived from a dihydroxy compound having a moiety represented by the formula (1) is preferably a structural unit represented by the following formula (5).

[0039] [ka]

[0040] Examples of dihydroxy compounds having a moiety represented by formula (1) include ether-containing dihydroxy compounds of oxyalkylene glycols, such as diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, and polypropylene glycol.

[0041] From the viewpoint of a balance between optical properties, heat resistance, mechanical properties, etc., the polycarbonate resin preferably contains a structural unit (C) in addition to the structural unit (A). Examples of dihydroxy compounds that form the structural unit (C) include aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, ether-containing dihydroxy compounds, aromatic-containing dihydroxy compounds, and diester compounds. Among these, from the viewpoints of weather resistance and moist heat resistance, alicyclic dihydroxy compounds are preferred.

[0042] Examples of aliphatic hydrocarbon dihydroxy compounds include straight-chain aliphatic dihydroxy compounds such as ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,5-heptanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol; and branched-chain aliphatic dihydroxy compounds such as 1,3-butanediol, 1,2-butanediol, neopentyl glycol, and hexylene glycol. Of these, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol are preferred.

[0043] Examples of dihydroxy compounds of alicyclic hydrocarbons include dihydroxy compounds which are primary alcohols of alicyclic hydrocarbons, such as 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, pentacyclopentadecanedimethanol, 2,6-decalindimethanol, 1,5-decalindimethanol, 2,3-decalindimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, 1,3-adamantanedimethanol, and dihydroxy compounds derived from terpene compounds such as limonene; and dihydroxy compounds which are secondary or tertiary alcohols of alicyclic hydrocarbons, such as 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantanediol, hydrogenated bisphenol A, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Among these, tricyclodecane dimethanol and 1,4-cyclohexanedimethanol are more preferred. The structural unit (C) derived from an alicyclic dihydroxy compound is preferably a structural unit represented by the following formula (6).

[0044] [ka]

[0045] Examples of aromatic-containing dihydroxy compounds that can be used include the following dihydroxy compounds: 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-diethylphenyl)propane, 2,2-bis(4-hydroxy-(3-phenyl)phenyl)propane, 2,2-bis(4-hydroxy-(3,5-diphenyl)phenyl)propane, and 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane. Pan, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)decane, bis(4-hydroxy-3-nitrophenyl) )methane, 3,3-bis(4-hydroxyphenyl)pentane, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane aromatic bisphenol compounds such as cyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, and 4,4'-(α-methylbenzylidene)bisphenol; dihydroxy compounds having an ether group bonded to an aromatic group such as 2,2-bis(4-(2-hydroxyethoxy)phenyl)propane, 2,2-bis(4-(2-hydroxypropoxy)phenyl)propane, 1,3-bis(2-hydroxyethoxy)benzene, and 4,4'-bis(2-hydroxyethoxy)biphenyl;9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxypropoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxypropoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylphenyl)fluorene, 9,9 and dihydroxy compounds having a fluorene ring, such as 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-cyclohexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butyl-6-methylphenyl)fluorene, and 9,9-bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl)fluorene. Preferably, the dihydroxy compound from which the structural unit (B) is derived is 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, 4,4'-(α-methylbenzylidene)bisphenol, or 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;

[0046] Examples of diester compounds include the following dicarboxylic acids: aromatic dicarboxylic acids such as terephthalic acid, phthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-benzophenonedicarboxylic acid, 4,4'-diphenoxyethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; and aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. These dicarboxylic acid components can be used as raw materials for polyester carbonate resins as dicarboxylic acids themselves, but depending on the production method, dicarboxylic acid esters such as methyl esters and phenyl esters, or dicarboxylic acid derivatives such as dicarboxylic acid halides can also be used as raw materials.

[0047] The mass ratio of the structural unit (C) in the polycarbonate resin is preferably 5% by mass or more, more preferably 25% by mass or more, and even more preferably 55% by mass or more, based on 100% by mass of all structural units constituting the polycarbonate resin. The mass ratio of the structural unit (C) is preferably 95% by mass or less, more preferably 85% by mass or less, and even more preferably 75% by mass or less. In these cases, the balance of other physical properties such as melt processability can be adjusted.

[0048] (carbonate diester) The polycarbonate resin of the present invention can be obtained by polycondensing a dihydroxy compound containing the specific dihydroxy compound described above and a carbonic acid diester as raw materials through an ester exchange reaction. The carbonic acid diester used is typically one represented by the following formula (7). These carbonic acid diesters may be used alone or in combination of two or more.

[0049] [ka]

[0050] (In formula (7), R 9 and R 10 are each an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, or an aromatic hydrocarbon group which may have a substituent, and R 9 and R 10 may be the same or different.)

[0051] R 9 and R 10 is preferably a substituted or unsubstituted aromatic hydrocarbon group, more preferably an unsubstituted aromatic hydrocarbon group. Examples of the substituent on the aliphatic hydrocarbon group include an ester group, an ether group, an amide group, and a halogen atom, and examples of the substituent on the aromatic hydrocarbon group include alkyl groups such as a methyl group and an ethyl group.

[0052] Examples of the carbonic acid diester represented by the formula (7) include diphenyl carbonate (hereinafter sometimes abbreviated as DPC), substituted diphenyl carbonates such as ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-tert-butyl carbonate, with diphenyl carbonate and substituted diphenyl carbonate being preferred, and diphenyl carbonate being particularly preferred.

[0053] The carbonate diester may contain impurities such as chloride ions, and these impurities may inhibit the polymerization reaction or deteriorate the hue of the resulting resin. Therefore, it is preferable to use a diester that has been purified by distillation or the like, as necessary.

[0054] The polycarbonate resin of the present invention can be synthesized by a process of polycondensation by transesterification using as raw materials a dihydroxy compound forming at least the structural unit represented by structural unit (A) and a carbonate diester. More specifically, the polycarbonate resin can be obtained by removing from the system, during polycondensation, the monohydroxy compound and other by-products produced in the transesterification reaction.

[0055] <Manufacturing method of polycarbonate resin> The transesterification reaction proceeds in the presence of a transesterification catalyst (hereinafter, the transesterification catalyst will be referred to as a "polymerization catalyst.") The type of polymerization catalyst can have a significant effect on the reaction rate of the transesterification reaction and the quality of the resulting polycarbonate resin.

[0056] The polymerization catalyst is not particularly limited as long as it can satisfy the transparency, color tone, heat resistance, weather resistance, and mechanical properties of the resulting polycarbonate resin. Examples of the polymerization catalyst that can be used include metal compounds of Group I or Group II (hereinafter simply referred to as "Group 1" and "Group 2") in the long periodic table, as well as basic compounds such as basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds, with Group 1 metal compounds and / or Group 2 metal compounds being preferred.

[0057] Examples of Group 1 metal compounds include the following compounds: sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, cesium borohydride, sodium phenylborohydride, and boron phenylide. Examples of the Group 1 metal compound include potassium, lithium boron phenylide, cesium boron phenylide, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, dicesium hydrogen phosphate, disodium phenylphosphate, dipotassium phenylphosphate, dilithium phenylphosphate, dicesium phenylphosphate, alcoholates and phenolates of sodium, potassium, lithium and cesium, and disodium salt, dipotassium salt, dilithium salt and dicesium salt of bisphenol A. As the Group 1 metal compound, lithium compounds are preferred from the viewpoints of polymerization activity and the color tone of the resulting polycarbonate resin.

[0058] Examples of Group 2 metal compounds include the following compounds: calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate. As the Group 2 metal compound, magnesium compounds, calcium compounds, or barium compounds are preferred, and from the viewpoints of polymerization activity and the color tone of the resulting polycarbonate resin, barium compounds, magnesium compounds, and / or calcium compounds are more preferred, and calcium compounds are most preferred.

[0059] Although it is possible to use a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound in combination with the Group 1 metal compound and / or Group 2 metal compound, it is more preferable to use only a Group 1 metal compound and / or a Group 2 metal compound, and most preferably, from the viewpoint of the color tone of the resulting polycarbonate resin, to use only a Group 2 metal compound.

[0060] The amount of the polymerization catalyst used is preferably 1 μmol or more, more preferably 3 μmol or more, and particularly preferably 5 μmol or more per mol of the total dihydroxy compounds used in the reaction, and is preferably 300 μmol or less, more preferably 200 μmol or less, and particularly preferably 100 μmol or less per mol of the total dihydroxy compounds used in the reaction.

[0061] By adjusting the amount of polymerization catalyst used within the above-mentioned range, the polymerization rate can be increased, making it possible to obtain a polycarbonate resin with a desired molecular weight without necessarily increasing the polymerization temperature, thereby suppressing deterioration in the color tone of the polycarbonate resin. Furthermore, it is possible to prevent unreacted raw materials from volatilizing during the polymerization, which would cause the molar ratio of the dihydroxy compound and the carbonate diester to be disrupted, thereby more reliably obtaining a resin with a desired molecular weight and copolymerization ratio. Furthermore, it is possible to suppress the occurrence of side reactions, thereby further preventing deterioration in the color tone of the polycarbonate resin or discoloration during molding.

[0062] The polycondensation of a dihydroxy compound and a carbonate diester is carried out in multiple stages using multiple reactors in the presence of the above-mentioned catalyst. The reaction may be carried out in a batchwise manner, a continuous manner, or a combination of a batchwise manner and a continuous manner, but it is preferable to adopt a continuous manner, which allows the production of a polycarbonate resin with less thermal history and is therefore excellent in productivity.

[0063] The dihydroxy compound and carbonate diester raw materials are preferably melted separately or uniformly mixed prior to the transesterification reaction. The melting or mixing temperature is typically 80°C or higher, preferably 90°C or higher, and typically 200°C or lower, preferably 160°C or lower, and particularly preferably 120°C or lower. In this case, the dissolution rate can be increased, the solubility can be sufficiently improved, and problems such as solidification can be sufficiently avoided. Furthermore, in this case, thermal degradation of the dihydroxy compound can be sufficiently suppressed, and the quality, typified by the color tone, of the resulting polycarbonate resin can be further improved.

[0064] From the viewpoint of controlling the polymerization rate and the quality of the resulting polycarbonate resin, it is important to appropriately select the jacket temperature, internal temperature, and pressure in the reaction system according to the reaction stage. Specifically, it is preferable to obtain a prepolymer at a relatively low temperature and low vacuum in the early stage of the polycondensation reaction, and to increase the molecular weight to a predetermined value at a relatively high temperature and high vacuum in the later stage of the reaction. In this case, distillation of unreacted monomers is suppressed, and it becomes easier to adjust the molar ratio of the dihydroxy compound to the carbonate diester to the desired ratio. As a result, a decrease in the polymerization rate can be suppressed. Furthermore, it becomes possible to more reliably obtain a polymer with the desired molecular weight and terminal groups.

[0065] Adjusting the temperature of the polycondensation reaction can improve productivity and prevent the product from being subjected to increased heat history. Furthermore, it is possible to further prevent volatilization of the monomer and decomposition and discoloration of the polycarbonate resin. Specifically, the following reaction conditions can be adopted for the first-stage reaction. The maximum internal temperature of the polymerization reactor is set within the range of usually 160 to 230°C, preferably 170 to 220°C, and more preferably 180 to 210°C. The pressure of the polymerization reactor (hereinafter, "pressure" refers to absolute pressure) is set within the range of usually 1 to 110 kPa, preferably 5 to 50 kPa, and more preferably 7 to 30 kPa. The reaction time is set within the range of usually 0.1 to 10 hours, preferably 1 to 5 hours. The first-stage reaction is preferably carried out while distilling off the generated monohydroxy compound from the reaction system.

[0066] From the second stage onwards, it is preferable to gradually reduce the pressure of the reaction system from the pressure of the first stage, and ultimately reduce the pressure (absolute pressure) of the reaction system to 1 kPa or less while continuously removing the generated monohydroxy compound from the reaction system. The maximum internal temperature of the polymerization reactor in the final stage is set within the range of usually 200 to 265°C, preferably 210 to 250°C, and particularly preferably 215 to 245°C. The reaction time in the final stage is usually 0.1 to 20 hours, preferably 0.5 to 15 hours.

[0067] It is preferable that the polycarbonate resin contains as little foreign matter as possible. In order to remove foreign matter such as discoloration and gel from the polycarbonate resin obtained by melt polycondensation, it is preferable to perform filtration using a filter. In particular, it is preferable to remove residual monomers, by-product phenol, etc. by devolatilization under reduced pressure, and to mix additives such as a heat stabilizer and a mold release agent, by melt-extruding the polycarbonate resin using a vented twin-screw extruder and then filtering it using a filter.

[0068] The filter can be in any known form, such as a candle type, pleated type, or leaf disc type. The filter mesh size, in terms of 99% filtration accuracy, is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 20 μm or less. When it is particularly important to reduce foreign matter, the filter mesh size is preferably 10 μm or less. However, smaller mesh sizes increase pressure loss in the filter, potentially leading to filter damage or deterioration of the polycarbonate resin due to shear heating. Therefore, in terms of 99% filtration accuracy, the filter mesh size is preferably 1 μm or more. The filter mesh size referred to here is determined in accordance with ISO 16889.

[0069] The polycarbonate resin filtered through the filter is discharged from a die head in the form of strands, cooled and solidified, and pelletized using a rotary cutter or the like. However, when stranding or pelletizing the polycarbonate resin, which comes into direct contact with the outside air, it is desirable to carry out this process in a clean room that is preferably Class 7, more preferably Class 6, as defined in JIS B 9920-1 (2019), in order to prevent the inclusion of foreign matter from the outside air.

[0070] During pelletization, cooling methods such as air cooling or water cooling are preferably used. The air used during air cooling should be freed of foreign matter using a HEPA filter or similar to prevent re-adhesion of the airborne foreign matter. When using water cooling, it is desirable to remove metals from the water using an ion-exchange polycarbonate resin or similar, and then use water from which foreign matter has been removed using a water filter. The mesh size of the water filter used is preferably 10 to 0.45 μm, providing a filtration accuracy of 99% removal.

[0071] In the method for producing the polycarbonate resin constituting the resin composition of the present invention, after polymerization as described above, the polycarbonate resin can usually be cooled and solidified, and pelletized using a rotary cutter, etc. The pelletization method is not limited, and examples include a method in which the polycarbonate resin is withdrawn in a molten state from the final polymerization reactor and cooled and solidified in the form of strands to be pelletized, a method in which the polycarbonate resin is fed in a molten state from the final polymerization reactor to a single-screw or twin-screw extruder, melt-extruded, and then cooled and solidified to be pelletized, and a method in which the polycarbonate resin is withdrawn in a molten state from the final polymerization reactor, cooled and solidified in the form of strands to be pelletized, and then fed again to a single-screw or twin-screw extruder, melt-extruded, and then cooled and solidified to be pelletized.

[0072] (Various additives) The polycarbonate resin may be blended with additives such as catalyst deactivators, antioxidants, heat stabilizers, neutralizing agents, light stabilizers, mold release agents, colorants, antistatic agents, lubricants, plasticizers, compatibilizers, flame retardants, and fillers, as needed. The additives may also be mixed using a tumbler, super mixer, floater, V-type blender, Nauta mixer, Banbury mixer, extruder, or the like. The blending of additives will be described with respect to the polycarbonate resin constituting the resin composition of the present invention, but the additives may be blended during the polymerization or production of the aromatic polycarbonate resin constituting the resin composition of the present invention, or may be blended during kneading of the polycarbonate resin constituting the resin composition of the present invention and the aromatic polycarbonate resin constituting the resin composition of the present invention.

[0073] Catalyst deactivator Adding an acidic compound to a polycarbonate resin to neutralize and deactivate the catalyst used in the polymerization reaction can improve color tone and thermal stability. The acidic compound used as a catalyst deactivator can be a compound having a carboxylic acid group, a phosphoric acid group, or a sulfonic acid group, or an ester thereof, but it is particularly preferable to use a phosphorus-based compound containing a partial structure represented by the following formula (8) or (9).

[0074] [ka]

[0075] [ka]

[0076] Examples of the phosphorus-based compound represented by the formula (8) or (9) include phosphoric acid, phosphonic acids, hypophosphorous acid, polyphosphoric acid, phosphonate esters, acidic phosphate esters, etc. Among the above, phosphonic acids and phosphonate esters are more effective in deactivating the catalyst and inhibiting coloration, and phosphonic acid (phosphorous acid), which is a phosphonic acid, is particularly preferred.

[0077] Examples of the phosphonic acids include phosphonic acid (phosphorous acid), methylphosphonic acid, ethylphosphonic acid, vinylphosphonic acid, decylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, aminomethylphosphonic acid, methylenediphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, 4-methoxyphenylphosphonic acid, nitrilotris(methylenephosphonic acid), and propylphosphonic anhydride.

[0078] Examples of the phosphonate esters include dimethyl phosphonate, diethyl phosphonate, bis(2-ethylhexyl) phosphonate, dilauryl phosphonate, dioleyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate, dimethyl methylphosphonate, diphenyl methylphosphonate, diethyl ethylphosphonate, diethyl benzylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, dipropyl phenylphosphonate, diethyl (methoxymethyl)phosphonate, diethyl vinylphosphonate, hydroxymethyl diethyl phosphonate, dimethyl (2-hydroxyethyl)phosphonate, diethyl p-methylbenzylphosphonate, diethyl phosphonoacetic acid, ethyl diethylphosphonoacetate, tert-butyl diethylphosphonoacetate, diethyl (4-chlorobenzyl)phosphonate, diethyl cyanophosphonate, diethyl cyanomethylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl phosphonoacetaldehyde diethyl acetal, and diethyl (methylthiomethyl)phosphonate.

[0079] Examples of the acidic phosphate ester include phosphate diesters such as dimethyl phosphate, diethyl phosphate, divinyl phosphate, dipropyl phosphate, dibutyl phosphate, bis(butoxyethyl) phosphate, bis(2-ethylhexyl) phosphate, diisotridecyl phosphate, dioleyl phosphate, distearyl phosphate, diphenyl phosphate, and dibenzyl phosphate, or mixtures of diesters and monoesters, diethyl chlorophosphate, and zinc stearyl phosphate.

[0080] These may be used alone or in any combination and ratio of two or more.

[0081] If the amount of the phosphorus-based compound added to the polycarbonate resin is too small, the catalyst deactivation and discoloration suppression effects will be insufficient, while if the amount is too large, the resin will discolor, especially in durability tests under high temperature and high humidity. The amount of the phosphorus-based compound added corresponds to the amount of catalyst used in the polymerization reaction. The amount of phosphorus-based compound added is preferably 0.5 to 5 times the molar amount of phosphorus atoms per 1 mole of the metal catalyst used in the polymerization reaction, more preferably 0.7 to 4 times the molar amount, and particularly preferably 0.8 to 3 times the molar amount.

[0082] Heat stabilizer If necessary, a heat stabilizer can be blended into the polycarbonate resin to prevent a decrease in molecular weight or deterioration in color during melt processing, etc. Examples of such heat stabilizers include commonly known hindered phenol-based heat stabilizers and / or phosphorus-based heat stabilizers.

[0083] Examples of the hindered phenol-based heat stabilizer include 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,5-di-tert-butylhydroquinone, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl

[0043] Examples of suitable esters include 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(6-cyclohexyl-4-methylphenol), 2,2'-ethylidene-bis-(2,4-di-tert-butylphenol), tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]-methane, and 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene. Among these, it is preferable to use tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]-methane, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, and 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0084] As the phosphorus-based heat stabilizer, for example, phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof shown below can be used, but phosphorus-based compounds other than these compounds can also be used. For example, triphenyl phosphite, tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite Examples of the heat stabilizers include bis(nonylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, triphenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, tetrakis(2,4-di-tert-butylphenyl)4,4'-biphenylenediphosphinate, dimethyl benzenephosphonate, diethyl benzenephosphonate, and dipropyl benzenephosphonate. These heat stabilizers may be used alone or in combination of two or more.

[0085] Such a heat stabilizer may be added to the reaction liquid during melt polymerization, or may be added to the resin using an extruder and kneaded. When a film is produced by melt extrusion, the heat stabilizer or the like may be added to the extruder to produce a film, or the heat stabilizer or the like may be added to the resin in advance using an extruder and formed into pellets or the like before use.

[0086] The amount of these heat stabilizers added is preferably 0.0001 parts by mass or more, more preferably 0.0005 parts by mass or more, and even more preferably 0.001 parts by mass or more, and is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.3 parts by mass or less, based on 100 parts by mass of polycarbonate resin.

[0087] Light stabilizers Examples of light stabilizers include 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(3-tert-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2,2'-methylenebis(4-cumyl-6-benzotriazolephenyl), and 2,2'-p-phenylenebis(1,3-benzoxazin-4-one).

[0088] These light stabilizers may be used alone or in combination of two or more. The blending amount of such light stabilizers is preferably 0.01 to 2 parts by mass, based on 100 parts by mass of the polycarbonate resin. Furthermore, a bluing agent can be blended into the polycarbonate resin according to the present invention to counteract the yellowish color due to the polymer or ultraviolet absorber. As the bluing agent, any agent that is used for polycarbonate resins can be used without any particular problems. In general, anthraquinone dyes are easily available and are therefore preferred.

[0089] Specific examples of bluing agents include Solvent Violet 13 (CA No. (Color Index No.) 60725), Solvent Violet 31 (CA No. 68210), Solvent Violet 33 (CA No. 60725), Solvent Blue 94 (CA No. 61500), Solvent Violet 36 (CA No. 68210), Solvent Blue 97 (Bayer's "Macrolex Violet RR"), and Solvent Blue 45 (CA No. 61110).

[0090] These bluing agents may be used alone or in combination of two or more. These bluing agents are usually used in an amount of 0.1 × 10 -4 ~2×10 -4 It is blended in a ratio of parts by mass.

[0091] <Aromatic polycarbonate resin> (Structural unit (B)) The aromatic polycarbonate resin in the present invention contains a structural unit (B) represented by the following formula (2).

[0092] [ka]

[0093] R in the above formula (2) 1 ~R 8 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, and X represents a direct bond, or a substituted or unsubstituted chain alkylene group having 1 to 20 carbon atoms excluding -C(CH3)2-, a substituted or unsubstituted cyclic alkylene group having 6 to 20 carbon atoms, or an arylene group having 6 to 20 carbon atoms excluding a fluorene skeleton.

[0094] Examples of chain alkylene groups and cyclic alkylene groups include -CH2-, -CH(CH3)-, -CH(Ph)-, -C(CH3)Ph-, -CPh2-, 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,1-cyclopropylene, 1,1-cyclobutylene, 1,1-cyclopentylene, 1,1-cyclohexylene, 3,3,5-trimethyl-1,1-cyclohexylene, 1,1-cyclododecylene, 1,2-cyclopropylene, 1,2-cyclobutylene, 1,2-cyclopentylene, 1,2-cyclohexylene, 1,3-cyclobutylene, 1,3-cyclopentylene, 1,3-cyclohexylene, and 1,4-cyclohexylene, where Ph is an unsubstituted phenyl group. Incidentally, -C(CH3)2- is not preferred because it has a high photoelastic coefficient and a low glass transition temperature, which results in low heat resistance.

[0095] Examples of the arylene group include a 1,2-phenylene group, a 1,3-phenylene group, and a 1,4-phenylene group. A fluorenylene group is not preferred because it exhibits negative birefringence and does not provide orientation as a retardation film. Furthermore, when X is a divalent hydrocarbon group having 1 to 20 carbon atoms, the bonding position on the benzene ring in the above formula (2) may be any of the 2,2'-position, 2,3'-position, 2,4'-position, 3,3'-position, 3,4'-position, and 4,4'-position, but is preferably the 4,4'-position, which further improves the mechanical properties.

[0096] On the other hand, when X is a direct bond, the biphenyl skeleton in the above formula (2) may be any one of a 2,2'-biphenyl skeleton, a 2,3'-biphenyl skeleton, a 2,4'-biphenyl skeleton, a 3,3'-biphenyl skeleton, a 3,4'-biphenyl skeleton, and a 4,4'-biphenyl skeleton, but is preferably a 4,4'-biphenyl skeleton. From the viewpoint of further improving the moist heat resistance of the polycarbonate resin composition, X in the above formula (2) is even more preferably -CH2-, -CH(CH3)-, -CH(Ph)-, -C(CH3)Ph-, -CPh2-, a 1,1-cyclohexylene group, a 3,3,5-trimethyl-1,1-cyclohexylene group, or a 1,1-cyclododecylene group.

[0097] In the above formula (2), R 1 ~R 8 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group. The substituted or unsubstituted alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and may have a substituent such as a phenyl group, and examples thereof include the following: Examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, an n-hexyl group, an isohexyl group, a cyclohexyl group, an n-heptyl group, a cycloheptyl group, a methylcyclohexyl group, an n-octyl group, a cyclooctyl group, an n-nonyl group, a 3,3,5-trimethylcyclohexyl group, an n-decyl group, a cyclodecyl group, an n-undecyl group, an n-dodecyl group, a cyclododecyl group, a benzyl group, a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, a naphthylmethyl group, a phenethyl group, and a 2-phenylisopropyl group. Examples of the substituted or unsubstituted aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, an ethylphenyl group, a styryl group, a xylyl group, an n-propylphenyl group, an isopropylphenyl group, a mesityl group, an ethynylphenyl group, a naphthyl group, and a vinylnaphthyl group, which may have a substituent such as an alkyl group, and a naphthyl group. R 1 ~R 8 is even more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.

[0098] Dihydroxy compounds from which the structural unit (B) is derived (i.e., dihydroxy compounds that constitute the structural unit (B)) include 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)decane, bis(4-hydroxy-3-nitrophenyl)methane, 3,3-bis(4-hydroxyphenyl) aromatic bisphenol compounds such as 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)pentane, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, and 4,4'-(α-methylbenzylidene)bisphenol; Preferably, the dihydroxy compound from which the structural unit (B) is derived is 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (sometimes abbreviated as BPTMC), 1,1-bis(4-hydroxyphenyl)cyclohexane, and 4,4'-(cyclododecane-1,1-diyl)diphenol, and more preferably 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

[0099] Particularly preferred specific examples of the structural unit (B) are represented by the following formulae (4), (10), and (11). The structural unit (B) is preferably at least one selected from the group consisting of the following formulae (4), (10), and (11), and more preferably a structural unit represented by the following formula (4). In this case, even if the content of the structural unit (B) in the aromatic polycarbonate resin is low, the heat resistance of the resin composition can be improved and the water absorption rate can be reduced. In other words, the heat resistance can be efficiently improved and the water absorption rate can be efficiently reduced. Furthermore, in this case, the photoelastic coefficient can be reduced.

[0100] [ka]

[0101] [ka]

[0102] [ka]

[0103] The mass ratio of the structural unit (B) in the aromatic polycarbonate is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, based on 100% by mass of all structural units constituting the aromatic polycarbonate resin. When the mass ratio is above the lower limit, heat resistance can be imparted. Furthermore, the mass ratio of the structural unit (B) is preferably 100% by mass or less, more preferably 98% by mass or less, and even more preferably 96% by mass or less. When the mass ratio is below the upper limit, flexibility can be imparted.

[0104] (Other structural units (E)) The aromatic polycarbonate resin may contain one or more structural units (E) different from the structural unit (B) within the scope of the present invention. As the structural unit (E), an aromatic-containing dihydroxy compound is preferred, and for example, the following dihydroxy compounds can be used. 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-diethylphenyl)propane, 2,2-bis(4-hydroxy-(3-phenyl)phenyl)propane, 2,2-bis(4-hydroxy-(3,5-diphenyl)phenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 1 aromatic bisphenol compounds such as 1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)decane, bis(4-hydroxy-3-nitrophenyl)methane, 3,3-bis(4-hydroxyphenyl)pentane, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, and 4,4'-(α-methylbenzylidene)bisphenol;Dihydroxy compounds having an ether group bonded to an aromatic group, such as 2,2-bis(4-(2-hydroxyethoxy)phenyl)propane, 2,2-bis(4-(2-hydroxypropoxy)phenyl)propane, 1,3-bis(2-hydroxyethoxy)benzene, and 4,4'-bis(2-hydroxyethoxy)biphenyl;9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxypropoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxypropoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylphenyl)fluorene, 9,9 and dihydroxy compounds having a fluorene ring, such as 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-cyclohexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butyl-6-methylphenyl)fluorene, and 9,9-bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl)fluorene. Preferably, the dihydroxy compound from which the structural unit (E) is derived is 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-(cyclododecane-1,1-diyl)diphenol, 4,4'-(α-methylbenzylidene)bisphenol, or 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, and more preferably 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, or 4,4'-(cyclododecane-1,1-diyl)diphenol;

[0105] The ratio of the structural unit (B) to the structural unit (E) is not particularly limited, but from the viewpoint of improving heat resistance and reducing the photoelastic coefficient, the structural unit (B) preferably accounts for 5 mol % or more of the sum of the contents of the structural unit (B) and the structural unit (E), more preferably 10 mol % or more, even more preferably 15 mol % or more, and particularly preferably 20 mol % or more.

[0106] <Method for producing aromatic polycarbonate resin> The aromatic polycarbonate resin of the present invention may be produced by any of the conventionally known methods, such as the phosgene method, the ester exchange method, the pyridine method, etc. As an example, the method for producing an aromatic polycarbonate resin by the ester exchange method will be described below.

[0107] The transesterification method is a production method in which a dihydroxy compound and a carbonic acid diester constituting the structural unit (B) are subjected to melt transesterification polycondensation in the presence of a basic catalyst and an acidic substance that neutralizes the basic catalyst.

[0108] Typical examples of carbonate diesters include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(biphenyl) carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, etc. Of these, diphenyl carbonate is particularly preferred.

[0109] The carbonyl group of the aromatic polycarbonate resin is a linking group; for example, when bisphenol A is used as the diol monomer, the resin is called bisphenol A resin, and when BPTMC and bisphenol A are used as the diol monomers, the resin is sometimes abbreviated as BPTMC / bisphenol A resin and expressed in terms of the diol monomer.

[0110] <Other Components and Compositions in Polycarbonate Resin Composition> (Other resins) The polycarbonate resin composition of the present invention may further contain other resins (hereinafter, sometimes referred to as "other resins"). Examples of other resins include aromatic polyesters, aliphatic polyesters, polycarbonate resins different from the polycarbonate resin and aromatic polycarbonate resin of the present invention, synthetic resins such as polyamide, polystyrene, polyolefin, polycycloolefin, acrylic, amorphous polyolefin, ABS, and AS, biodegradable resins such as polylactic acid and polybutylene succinate, and rubber. Among these, aromatic polycarbonate resins and polymethyl methacrylate resins containing 2,2-bis(4-hydroxyphenyl)propane as a monomer component are preferred from the viewpoint of versatility.

[0111] The content of the other resin is preferably 80% by mass or less, more preferably 50% by mass or less, and particularly preferably 30% by mass or less, based on the total mass of the resin components in the polycarbonate resin composition of the present invention. Within this range, the balance of other physical properties such as heat resistance and melt processability can be adjusted without significantly impairing the properties of the polycarbonate resin composition of the present invention.

[0112] (Composition of the composition) The polycarbonate resin composition of the present invention preferably has a mass ratio of polycarbonate resin to aromatic polycarbonate constituting the composition of 99:1 to 1:99, more preferably 90:10 to 10:90, and even more preferably 80:20 to 20:80. If the mass ratio is within the above upper and lower limits, the composition can be used for molded articles or films.

[0113] (ultraviolet absorber) The composition of the present invention can be used as an optical film to be mounted on a display. Examples of optical films include a surface protection film, a polarizer protection film, and a retardation film. Films used for these applications need to have UV-blocking properties to prevent deterioration of liquid crystal molecules and the polarizer (PVA) in the polarizing plate due to UV rays entering from the outside or contained in backlight light. From this perspective, the polycarbonate resin composition of the present invention preferably contains an UV absorber.

[0114] When kneading the polycarbonate resin and aromatic polycarbonate resin constituting the polycarbonate resin composition of the present invention, it is preferable to mix an ultraviolet absorber with a tumbler, super mixer, floater, V-blender, Nauta mixer, Banbury mixer, extruder, etc. The ultraviolet absorbers used in the present invention may be used alone or in combination of two or more.

[0115] The amount of the ultraviolet absorber used in the present invention is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, relative to 100% by mass of the polycarbonate resin composition. At or above the lower limit, transmittance in the visible light region around 430 nm is increased, making it easier to obtain transparency. Also, the amount is preferably 3.0% by mass or less, more preferably 2.5% by mass or less, and even more preferably 2.0% by mass or less. At or below the upper limit, heat resistance can be maintained and an increase in foreign matter due to aggregation of the ultraviolet absorber can be prevented. As long as the content in the finally obtained polycarbonate resin composition is within the above range, the ultraviolet absorber may be added to the polycarbonate resin or aromatic polycarbonate resin constituting the polycarbonate resin composition.

[0116] Preferred ultraviolet absorbers include triazines, benzotriazoles, benzophenones, quinolinones, benzoates, cyanoacrylates, and benzoxazoles, and from the viewpoint of weather resistance and long wavelength absorption, triazines, benzotriazoles, and benzoxazoles are preferred.

[0117] Triazine-based UV absorbers Examples of triazine-based ultraviolet absorbers include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, and 2,6-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine. Phenyl-4-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy- 4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, 2, 4,6-tris(2-hydroxy-4-ethoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-propoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-methoxycarbonylpropyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-ethoxycarbonylethyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-4-(1-(2-ethoxyhexyloxy)-1-oxopropan-2-yloxy)phenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-propoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyphenyl)-1,3,5-triazine 2,4,6-tris(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-octyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-dodecyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-benzyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxyphenyl)-1,3,5-triazine 2,4,6-tris(2-hydroxy-3-methyl-4-butoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-propoxyethoxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-methoxycarbonylpropyloxyphenyl)-1,3,5-triazine, 2,4,6-tris(2-hydroxy-3-methyl-4-ethoxycarbonylethyloxyphenyl)-1,3,5-triazine, Examples include 2,4,6-tris(2-hydroxy-3-methyl-4-(1-(2-ethoxyhexyloxy)-1-oxopropan-2-yloxyphenyl)-1,3,5-triazine, 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-N-octyloxyphenyl)-1,3,5-triazine, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(2-(2-ethylhexanoyloxy)ethoxy)phenol, and 2,4,6-tris(4-butoxy-2-hydroxyphenyl)-triazine.

[0118] Among them, a commercially available product is 2,4,6-tris(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine ("ADEKA STAB LA-F70" manufactured by ADEKA Corporation).

[0119] Benzotriazole-based UV absorbers Examples of the benzotriazole-based ultraviolet absorber include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-[2'-hydroxy-3',2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 5'-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)- 2-(2-hydroxy-3',5'-di-tert-amylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-(3",4",5",6"-tetrahydrophthalimidomethyl)-5'-methylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-pentylphenyl), 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], and the like.

[0120] Among these, a commercially available product is 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol] ("ADEKA STAB LA-31" manufactured by ADEKA Corporation).

[0121] Benzoxazoles Fluorescent brighteners such as 7-(dimethylamino)-4-methylcoumarin, 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene (BASF Japan Ltd. "TINOPAL OB CO"), and 4,4'-bis(2-benzoxazolyl)stilbene are also available as benzoxazole-based fluorescent brighteners.

[0122] The 5% weight loss temperature of the ultraviolet absorber used in the present invention is preferably higher than 230°C. Furthermore, it is more preferably higher than 250°C, and even more preferably higher than 280°C. By having a temperature equal to or higher than this lower limit, the ultraviolet absorber can be prevented from decomposing or volatilizing during melt-kneading. This not only allows the ultraviolet absorber to fully exhibit its capabilities, but also prevents decomposition products from accumulating in the extrusion vent, which would hinder continuous operation, or from accumulating on the T-die, rolls, etc., which would impair the appearance of the film.

[0123] From the viewpoint of heat resistance, the molecular weight of the ultraviolet absorber used in the present invention is preferably 350 or more, more preferably 400 or more, and even more preferably 450 or more. If the molecular weight is above this lower limit, volatilization can be prevented when the resin produced by melt polymerization is kneaded in an extruder. This not only allows the ultraviolet absorber to fully exhibit its capabilities, but also prevents decomposition products from accumulating in the extrusion vent, which would hinder continuous operation, and prevents volatile materials from accumulating on the T-die, rolls, etc., which would impair the appearance of the film.

[0124] <Method for producing polycarbonate resin composition> The polycarbonate resin composition of the present invention can be produced, for example, by a method of mechanically melt-kneading the above-mentioned components constituting the polycarbonate resin composition. Examples of melt-kneading machines that can be used include single-screw extruders, twin-screw extruders, Brabender mixers, Banbury mixers, kneader blenders, and roll mills. During kneading, the components may be kneaded all at once, or a multi-stage division kneading method may be used in which an optional component is kneaded and then the remaining components are added and kneaded. Among these, a method in which the components are continuously added to a twin-screw extruder equipped with a vacuum vent to continuously obtain a polycarbonate resin composition is preferred from the viewpoints of productivity and quality uniformity. The lower limit of the kneading temperature is usually 150°C or higher, preferably 180°C or higher, and more preferably 200°C or higher. The upper limit of the kneading temperature is usually 290°C or lower, preferably 280°C or lower, and more preferably 270°C or lower. Within this range, productivity (the kneading processing speed) can be increased while suppressing thermal degradation due to heating by the kneader and shear heat generation.

[0125] [Molded products] The polycarbonate resin composition of the present invention can be processed into various molded articles by molding methods such as injection molding (insert molding, two-color molding, sandwich molding, gas injection molding, etc.), extrusion molding, inflation molding, T-die film molding, lamination molding, blow molding, hollow molding, compression molding, and calendar molding. Among these, injection molding is preferred in terms of productivity and the degree of freedom in design of the molded article. The shape of the molded article is not particularly limited, and examples include sheets, films, plates, particles, lumps, fibers, rods, porous bodies, and foams. Sheets, films, and plates are preferred, and plate-shaped molded articles are particularly preferred because they are suited to the properties of the polycarbonate resin composition of the present invention. The molded film can also be stretched uniaxially or biaxially. Examples of stretching methods include a roll method, a tenter method, and a tubular method. Furthermore, surface treatments commonly used in industry, such as corona discharge treatment, flame treatment, plasma treatment, and ozone treatment, can also be applied.

[0126] [lens] The polycarbonate resin composition of the present invention can be used for optical lenses such as eyeglass lenses, cameras, telescopes, binoculars, and television projectors, and the Abbe number and refractive index can be easily adjusted to a desired value by changing the blending ratio. The composition of the present invention combines the respective advantages of the polycarbonate resin and aromatic polycarbonate resin that constitute the composition, thereby providing well-balanced and excellent optical properties. The Abbe number is preferably in the range of 33 to 55, more preferably 35 to 55. The refractive index is preferably in the range of 1.52 to 1.57, more preferably 1.53 to 1.56.

[0127] [film] A film made of the polycarbonate resin composition of the present invention can be used as an optical film such as a protective film, a retardation film, a polarizing film, a brightness enhancing film, a diffusion film, etc. The terms film and sheet are essentially synonymous.

[0128] (protective film) The film made of the polycarbonate resin composition of the present invention can be used as a protective film such as a surface protective film or a polarizer protective film. The in-plane retardation Re(550) of the protective film is 30 nm or less, preferably 20 nm or less, and more preferably 15 nm or less. The smaller the in-plane retardation Re(550), the better.

[0129] When used as a protective film, it may be unstretched or stretched. If it is too thick, thickness unevenness is likely to occur, and if it is too thin, it may break during transportation or stretching, so it is usually 5 μm or more, preferably 20 μm or more. Also, it is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 120 μm or less. If it is within the above upper and lower limit range, it can be suitably used for optical products such as surface protective films and polarizer protective films, and for electric and electronic components.

[0130] When used as a protective film, the film may be subjected to a hard coat layer, anti-reflection treatment, anti-sticking treatment, or treatment for diffusion or anti-glare, or may be subjected to a surface treatment such as corona discharge treatment or ultraviolet irradiation treatment before bonding. Also, an anti-blocking agent such as silica or a crosslinked acrylic resin may be formulated.

[0131] (Method of manufacturing unstretched film) As a method for forming an unstretched film using the polycarbonate resin composition of the present invention, a casting method in which the polycarbonate resin composition of the present invention is dissolved in a solvent and cast, and then the solvent is removed, or a melt film-forming method in which the resin is melted without using a solvent to form a film can be used. Specific examples of melt film-forming methods include melt extrusion using a T-die, calendar molding, heat pressing, co-extrusion, co-melting, multilayer extrusion, inflation molding, etc. The method for producing an unstretched film is not particularly limited, but since casting methods can cause problems due to residual solvent, melt film-forming methods are preferred, and in particular, melt extrusion using a T-die is preferred because of the ease of subsequent stretching treatment.

[0132] When forming an unstretched film by a melt-casting method, the forming temperature is preferably 280° C. or lower, more preferably 270° C. or lower, and particularly preferably 265° C. or lower. If the forming temperature is too high, the resulting film may have more defects due to the generation of foreign matter or bubbles, or the film may become discolored.

[0133] However, if the molding temperature is too low, the melt viscosity of the resin becomes too high, making it difficult to mold the raw film and producing an unstretched film with a uniform thickness, so the lower limit of the molding temperature is usually 200° C. or higher, preferably 210° C. or higher, and more preferably 220° C. or higher. Here, the molding temperature of the unstretched film refers to the temperature during molding in a melt film-forming method, and is usually the value measured by measuring the resin temperature at the outlet of a die from which the molten resin is extruded.

[0134] Furthermore, the presence of foreign matter in the film can result in defects such as light leakage when used as a polarizing plate. To remove foreign matter from the resin, a preferred method is to attach a polymer filter after the extruder, filter the resin, and then extrude it through a die to form a film. In this process, the extruder, polymer filter, and die must be connected by piping to transport the molten resin. However, to minimize thermal degradation within the piping, it is important to arrange each piece of equipment so that the residence time is minimized. Furthermore, the film transport and winding process after extrusion must be carried out in a clean room, and utmost care must be taken to prevent foreign matter from adhering to the film.

[0135] If the thickness of the unstretched film is too thin, it becomes difficult to handle and wrinkles or breaks may occur during production, so the lower limit of the thickness is preferably 10 μm or more, more preferably 15 μm or more, even more preferably 25 μm or more, and particularly preferably 30 μm or more, and is preferably 450 μm or less, more preferably 300 μm or less, even more preferably 200 μm or less, and particularly preferably 160 μm or less.

[0136] Furthermore, if an unstretched film has uneven thickness, it will cause uneven retardation when stretched and used as a retardation film. Therefore, the thickness of the portion to be used as a retardation film is preferably the set thickness ±3 μm or less, more preferably the set thickness ±2 μm or less, and particularly preferably the set thickness ±1 μm or less.

[0137] The length of the unstretched film in the longitudinal direction is preferably 500 m or more, more preferably 1000 m or more, and even more preferably 1500 m or more. From the viewpoints of productivity and quality, continuous stretching is preferred when producing the retardation film of the present invention. However, conditions usually need to be adjusted at the start of stretching to achieve a predetermined retardation, and if the film length is too short, the amount of product obtainable after condition adjustment decreases.

[0138] (Method of manufacturing phase difference film) A retardation film can be obtained by stretching and orienting an unstretched film. As the stretching method, known methods such as longitudinal uniaxial stretching, transverse uniaxial stretching using a tenter or the like, or a combination thereof, such as simultaneous biaxial stretching or sequential biaxial stretching, can be used. The stretching may be performed in a batch system, but continuous stretching is preferred in terms of productivity. Furthermore, compared with the batch system, a continuous system can produce a retardation film with less variation in the in-plane retardation of the film.

[0139] The stretching temperature is in the range of (Tg-20°C) to (Tg+30°C), preferably (Tg-10°C) to (Tg+20°C), and more preferably (Tg-5°C) to (Tg+15°C), relative to the glass transition temperature (Tg) of the polycarbonate resin composition used as the raw material.

[0140] The stretching ratio is determined depending on the desired retardation value, and is preferably 1.1 to 4 times, more preferably 1.2 to 3.5 times, in both the longitudinal and transverse directions. If the stretching ratio is too small, the effective range for obtaining the desired degree of orientation and orientation angle becomes narrow. On the other hand, if the stretching ratio is too large, the film may break or wrinkle during stretching. When used as a protective film, a stretching ratio of 1:1 is desirable.

[0141] The stretching speed is also appropriately selected depending on the purpose, but can be selected so that the strain rate represented by the following formula is preferably 50% to 2000%, more preferably 100% to 1500%, even more preferably 200% to 1000%, and particularly preferably 250% to 500%.

[0142] An excessively high stretching speed may cause breakage during stretching or may result in significant fluctuations in optical properties due to long-term use under high-temperature conditions.An excessively low stretching speed may not only reduce productivity but also require an excessively high stretch ratio to obtain a desired retardation. Strain rate (% / min) = {stretching rate (mm / min) / length of original film (mm)} x 100

[0143] After stretching the film, a heat setting treatment may be performed in a heating furnace as needed, or a relaxation step may be performed by controlling the tenter width or adjusting the roll peripheral speed. The heat setting temperature is in the range of 60°C to (Tg), preferably 70°C to (Tg-5°C) relative to the glass transition temperature (Tg) of the resin composition used in the unstretched film. If the heat treatment temperature is too high, the molecular orientation obtained by stretching may be disturbed, resulting in a significant decrease in the desired retardation. Note that when a polycarbonate resin composition has multiple Tgs, the average Tg value is used as the standard for judgment.

[0144] Furthermore, when a relaxation step is performed, the stress generated in the stretched film can be removed by shrinking the film to 95% to 99% of the width expanded by stretching. The treatment temperature applied to the film in this case is the same as the heat setting temperature. By performing the heat setting and relaxation steps as described above, it is possible to suppress fluctuations in optical properties due to long-term use under high temperature conditions.

[0145] The retardation film of the present invention can be produced by appropriately selecting and adjusting the processing conditions in such a stretching step.

[0146] The retardation film of the present invention preferably has an in-plane birefringence (Δn) at a wavelength of 550 nm of 0.001 or more, more preferably 0.002 or more, and particularly preferably 0.0025 or more. Since the retardation is proportional to the film thickness (d) and birefringence (Δn), by setting the birefringence within the above-mentioned specific range, it becomes possible to achieve the designed retardation in a thin film, and a film suitable for thin devices can be easily produced.

[0147] The retardation film exhibits flat wavelength dispersion characteristics in which the retardation value hardly changes depending on the wavelength of the measuring light. The Re(450) / Re(550) of the retardation film is preferably 0.98 to 1.05, and more preferably 0.98 to 1.04.

[0148] The retardation film of the present invention preferably has an in-plane retardation Re(550) of 100 nm to 600 nm at a wavelength of 550 nm. When the in-plane retardation Re(550) value is within this range, the film can be suitably used as a 1 / 4λ plate, a 1 / 2λ plate, etc.

[0149] Furthermore, in the case of displays using a general polarizing plate, light passing through the polarizing plate is linearly polarized, and therefore, when the display is viewed through polarized sunglasses, blackout may occur depending on the angle. To solve this problem, a retardation film may be used as the surface layer of an optical display. The composition of the present invention can also be suitably used in these retardation films.

[0150] In order to achieve high birefringence, the degree of orientation of the polymer molecules must be increased by lowering the stretching temperature, increasing the stretching ratio, etc., but since such stretching conditions make the film more susceptible to breakage, it is advantageous to use a resin with better toughness.

[0151] The retardation film of the present invention preferably has a thickness of 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less, although this depends on the design value of the retardation.

[0152] On the other hand, if the thickness is too thin, the film becomes difficult to handle, and wrinkles or breakage occurs during production. Therefore, the lower limit of the thickness of the retardation film of the present invention is preferably 10 μm or more, more preferably 15 μm or more.

[0153] <Characteristics of molded products> A molded article made using the polycarbonate resin composition of the present invention preferably has the following physical properties.

[0154] (Total light transmittance) The total light transmittance of a molded article using the polycarbonate resin composition of the present invention is preferably 85% or more, more preferably 87% or more, and even more preferably 89% or more. If the total light transmittance is equal to or greater than the above lower limit, a colorant can be blended into the resin to produce a coloring material that develops sharp colors, and the resin can be used for components that require transparency, such as optical films.

[0155] (photoelastic coefficient) The molded article using the polycarbonate resin composition of the present invention has a photoelastic coefficient of 60×10 -12 Pa -1 It is preferable that the photoelastic coefficient is 60×10 or less. -12 Pa -1 If the photoelastic coefficient is larger than 55×10, when the film is bonded to a polarizing plate as a retardation film and the polarizing plate is then mounted on a display device, stress at the time of bonding will cause partial stress to be applied to the retardation film due to the viewing environment or heat from the backlight, resulting in non-uniform retardation change and a significant deterioration in image quality. -12 Pa -1 More preferably, it is 50×10 -12 Pa -1 It is even more preferable that:

[0156] (average molecular weight) The average molecular weight of the polycarbonate resin composition of the present invention can be expressed by reduced viscosity. This reduced viscosity is preferably 0.30 dL / g or more, more preferably 0.40 dL / g or more. Below the lower limit, the mechanical strength of the molded product is weak. The upper limit of the reduced viscosity is preferably 0.53 dL / g or less, more preferably 0.50 dL / g or less. Above the upper limit, the fluidity during molding decreases, the cycle characteristics decrease, and the molding cycle becomes longer. The reduced viscosity of the polycarbonate resin composition can be measured by the method described in the Examples below. The reduced viscosity was measured at 20°C, and the fluctuation range was adjusted within a range of ±1°C.

[0157] (saturated water absorption rate) The saturated water absorption of a molded article made from the polycarbonate resin composition of the present invention is preferably 0.8 wt% or less, more preferably 0.75 wt% or less. If it is below the upper limit, the amount of deformation of the molded article in a humid and hot environment can be reduced.

[0158] (Refractive index / Abbe number) The refractive index and Abbe number can be adjusted as desired by adjusting the mass ratio of the polycarbonate resin and aromatic polycarbonate resin that constitute the polycarbonate resin composition of the present invention. The refractive index at a wavelength of 589 nm is preferably in the range of 1.52 to 1.57, more preferably 1.53 to 1.56. The Abbe number is preferably in the range of 33 to 55, more preferably 35 to 55.

[0159] (glass transition temperature (Tg)) The polycarbonate resin composition of the present invention preferably has a single glass transition temperature. Generally, a polymer blend composition having a single glass transition temperature means that the mixed resins are in a compatible state at the molecular level, and is recognized as a compatible system. This allows the composition to be used to suppress delamination in molded products and as a retardation film by stretching. Furthermore, a glass transition temperature of 105°C or higher has been evaluated as having heat resistance. A glass transition temperature of 110°C or higher is more preferable.

[0160] (Wavelength 380nm transmittance) The light transmittance at a wavelength of 380 nm of a molded article using the polycarbonate resin composition of the present invention is preferably 95% or less, more preferably 80% or less, and particularly preferably 60% or less. When the light transmittance is equal to or less than the upper limit, the optical film used has good visibility and can block ultraviolet light. The transmittance of the resin composition can be measured by the method described in the following examples. [Example]

[0161] Examples of the resin composition are shown below, but the present invention is not limited to these examples as long as they do not depart from the gist of the invention. The methods for measuring each property are as follows.

[0162] <Preparation of unstretched film> Each resin composition pellet or each resin pellet was dried at 100°C for 12 hours or more under a reduced pressure of 200 Pa or less. Next, 3 to 5 g of the dried pellets were placed in a small heat press (AS ONE Corporation, AH-2003C AH-1TC) in a 14 cm long x 14 cm wide format, with or without a spacer depending on the thickness. Polyimide films were placed on the top and bottom of the sample, and the sample was preheated at a temperature of 200 to 260°C depending on the glass transition temperature for 3 minutes, pressed at a pressure of 7 MPa for 5 minutes, then removed together with the spacers, cooled, and the polyimide films were peeled off to produce an unstretched film. The higher the temperature and the thinner the spacer, the thinner the film thickness can be, making it possible to adjust the film thickness to the desired value. Film thickness was measured using a constant-pressure thickness gauge conforming to JIS K6250, and was 90±3 μm in Table 1 (Examples 1-6, Comparative Examples 1-6), 150±5 μm in Table 2 (Examples 7 and 8), and various film thicknesses were adjusted by varying the temperature conditions and the presence or absence of spacers in Table 3 (Examples 11, 13-15). In Table 3, films produced using a small heat press are referred to as "pressed."

[0163] <Production of molded product (Example 9)> Polycarbonate resin composition pellets vacuum dried at 90°C for 5 hours or more were used to produce molded articles measuring 25 mm square and 3.2 mm thick at a molding temperature of 210 to 260°C using a small injection molding machine C, Mobile-0813 (manufactured by Shinko Selvic Co., Ltd.). The molded articles obtained in this manner are referred to as "extrusion molded" in Table 3.

[0164] <Preparation of Solution-Cast Film (Example 10)> Approximately 1 g of the resulting resin pellets was placed in a screw bottle with a lid, followed by approximately 10 ml of methylene chloride, which was then capped and left to stand for 12 hours. The solution containing the dissolved resin pellets was gently shaken to homogenize it, then poured into a round-bottom aluminum dish approximately 60 mm in diameter and 20 mm in height and air-dried for 24 hours. The solution was then dried at 40°C for 6 hours in a temperature-controlled vacuum dryer to volatilize traces of methylene chloride, and the film was removed from the aluminum dish. The solution-cast film obtained in this manner is referred to as "solution cast" in Table 3.

[0165] <Preparation of Membrane Film (Example 12)> Polycarbonate resin composition pellets were vacuum-dried at 90°C for 5 hours or more, and the polycarbonate resin was extruded into a film form from a T-die (width: 400 mm, set temperature: 200-270°C) using a single-screw extruder (screw diameter: 30 mm, cylinder set temperature: 220-270°C) manufactured by Technovel Co., Ltd. by melt extrusion. The extruded film was wound into a roll using a winder while being cooled with a chill roll (set temperature: 100-170°C). The molded product obtained in this manner is referred to as "extrusion film" in Table 3.

[0166] <Total light transmittance> The total light transmittance was measured for the unstretched film or molded product prepared by the above method using a spectral color maze meter COH7700 (manufactured by Nippon Denshoku Industries Co., Ltd.) according to the method of JIS K7136. The higher the total light transmittance, the better the transparency.

[0167] <Photoelastic coefficient> (Sample production) A 4.0 g sample of each resin composition pellet or resin pellet, which had been vacuum-dried at 80°C for 5 hours, was placed in a heat press using a spacer 8 cm wide, 8 cm long, and 0.5 mm thick at 200-260°C for 1-3 minutes of preheating and a pressure of 20 MPa for 1 minute. The sample was then removed from the heat press with the spacer and cooled under pressure at 20 MPa for 3 minutes in a water-tube-cooled press to produce a sheet. A sample 5 mm wide and 20 mm long was cut from this sheet.

[0168] (measurement) Measurements were made using a device that combines a birefringence measuring device consisting of a He-Ne laser, polarizer, compensator, analyzer, and photodetector with a vibration-type viscoelasticity measuring device (Rheology Co., Ltd. "DVE-3"). (For details, see Journal of the Rheological Society of Japan, Vol. 19, pp. 93-97 (1991).)

[0169] The cut sample was fixed to a viscoelasticity measuring device, and the storage modulus E' was measured at a frequency of 96 Hz at a room temperature of 25°C. Simultaneously, the emitted laser light was passed through a polarizer, sample, compensator, and analyzer in that order, and picked up by a photodetector (photodiode). The amplitude and phase difference relative to strain were measured for waveforms with angular frequencies ω or 2ω via a lock-in amplifier, and the strain-optical coefficient O' was calculated. The polarizer and analyzer were aligned perpendicular to each other and at an angle of π / 4 relative to the stretching direction of the sample. The photoelastic coefficient was calculated using the storage modulus E' and strain-optical coefficient O' from the following equation: Photoelastic coefficient = 0´ / E´

[0170] <Reduced viscosity> Using methylene chloride as a solvent, a solution of each resin composition or resin with a concentration of 0.6 g / dL was prepared. Measurements were carried out at a temperature of 20.0°C ± 0.1°C using an Ubbelohde viscometer manufactured by Moritomo Rika Kogyo Co., Ltd., and the relative viscosity ηrel was calculated from the solvent transit time t0 and the solution transit time t using the following formula: ηrel=t / t0 Next, the specific viscosity ηsp was calculated from the obtained relative viscosity ηrel using the following formula. ηsp=(η-η0) / η0=ηrel-1 (η0 is the viscosity of the solvent.) The specific viscosity was then divided by the concentration c (g / dL) to determine the reduced viscosity (ηsp / c). The higher this value, the greater the molecular weight.

[0171] <Measurement of saturated water absorption> Square test pieces measuring 10 cm long and 10 cm wide were cut from the unstretched films and molded articles prepared by the above-mentioned method. The test pieces were dried for at least 24 hours under a reduced pressure of 200 Pa or less at a temperature equal to the glass transition temperature of the resin constituting the test piece or the lowest glass transition temperature of the resin composition minus 10°C (Tg - 10°C). The mass of the dried test piece was measured to the nearest 0.1 mg, and this value was recorded as the dry weight. The dried sample was then immersed in demineralized water maintained at 23°C for at least 72 hours. After immersion, the test piece was removed from the demineralized water, and all surface moisture was wiped off with a clean, dry cloth or filter paper. The weight of the test piece was then measured to the nearest 0.1 mg, and this value was recorded as the water absorption weight. The water absorption weight was measured within 30 seconds of removal from the water. The saturated water absorption (wt%) was calculated from the water absorption weight and dry weight using the following formula. The calculated water absorption is the saturated water absorption. (Water absorption weight - dry weight) / dry weight x 100 = saturated water absorption rate

[0172] <Refractive index / Abbe number> Approximately 5 g of each resin composition pellet or resin pellet was placed inside a 14 cm x 14 cm x 0.1 mm thick stainless steel spacer. Polyimide films were placed on the top and bottom of the sample. The sample was preheated at 200-260°C for 3 minutes, then pressurized at 7 MPa for 5 minutes. The sample was then removed from the spacer and cooled to produce an unstretched film. Rectangular test pieces measuring 90 μm ± 3 μm, 40 mm long, and 8 mm wide were cut from the unstretched film to serve as measurement samples. The refractive indices were measured at wavelengths of 486 nm, 589 nm, and 656 nm using a multi-wavelength Abbe refractometer DR-M4 / 1550 (manufactured by Atago Co., Ltd.). Measurements were performed at 20°C using monobromonaphthalene as the interface liquid. Furthermore, the Abbe number (ν) was calculated using the following formula. ν=(nD-1) / (nF-nC) nD: Refractive index at a wavelength of 589 nm nC: Refractive index at a wavelength of 656 nm nF: Refractive index at a wavelength of 486 nm

[0173] <Glass transition temperature (Tg)> Glass transition temperatures (Tg) were measured using a Hitachi High-Tech Science Corporation NEXTA DSC200 differential scanning calorimeter. Approximately 10 mg of each resin composition pellet or resin pellet was placed in a Hitachi High-Tech Science aluminum pan, sealed, and heated from 30°C to 200°C at a heating rate of 20°C / min under a 50 mL / min nitrogen stream. After holding the temperature for 3 minutes, the sample was cooled to 30°C at a rate of 20°C / min. The sample was then held at 30°C for 3 minutes and heated again to 200°C at a rate of 20°C / min. From the DSC data obtained during the second heating run, the extrapolated glass transition onset temperature was determined as the temperature at the intersection of a line extending the low-temperature baseline toward the high-temperature side and a tangent drawn at the point where the gradient of the stepwise change in the glass transition curve is maximized. This was taken as the glass transition temperature. A glass transition temperature of 105°C or higher was considered to have excellent heat resistance.

[0174] <Forming of Retardation Film (Examples 7 and 8)> A length of 145 mm and a width of 95 mm was cut out from the unstretched film obtained by the above method, and fixed-end uniaxial stretching was performed using a batch-type biaxial stretching device (Island Industrial Co., Ltd. biaxial stretching device BIX-277-AL) at a stretching speed of 400% / min and a stretch ratio of 2.2 or 2.6 to obtain a retardation film. The stretching temperature was the predetermined stretching temperature shown in Method 2.

[0175] (Measurement of birefringence (Δn) and wavelength dispersion (R450 / R550)) The central portion of the obtained retardation film was cut into a length of 4 cm and a width of 4 cm, and the retardation was measured at wavelengths of 450, 500, 550, 590, 630, and 750 nm using a retardation measuring device KOBRA-WPR manufactured by Oji Scientific Instruments, and the wavelength dispersion was measured. The wavelength dispersion was expressed as the ratio (R450 / R550) of the retardation R450 measured at 450 nm and R550 measured at 550 nm.

[0176] Further, the birefringence Δn was calculated from the retardation R550 at 550 nm and the film thickness of the retardation film using the following formula. Birefringence (Δn) = R550 [nm] / (film thickness [mm] × 10 6 )

[0177] <Wavelength 380nm transmittance> Using a UV-Vis-NIR spectrophotometer (JASCO Corporation, V-730), the unstretched film or molded product prepared by each of the above methods was set so that the film thickness measurement portion was in the light path, and measurements were performed in transmittance (%) mode, with a response time of 0.015 sec, at wavelengths of 190 to 1100 nm, and in 1 nm intervals across the bandwidth. From the transmittance data obtained at each wavelength, the transmittance (%) at a wavelength of 380 nm was read.

[0178] <Raw materials used> In the following Production Examples, Examples and Comparative Examples, various compounds and resins are represented by abbreviations as follows:

[0179] (monomer) ISB: Isosorbide (manufactured by Rocket Fleuret) TCDDM: Tricyclodecane dimethanol (OQ Chemicals) DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation) BPTMC: 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (Honshu Chemical Industry Co., Ltd.)

[0180] (aromatic polycarbonate resin) Resin-2: APEC1895 (BPTMC / bisphenol A resin) (Covestro) Resin-3: APEC2095 (BPTMC / bisphenol A resin) (Covestro) Resin-5: 7022J (bisphenol A resin) (Mitsubishi Chemical Corporation)

[0181] (ultraviolet absorber) UV absorber: LA-F70 (ADEKA)

[0182] <Production Example 1: Resin-1> Polymerization was carried out using a batch polymerization apparatus consisting of two vertical stirred reactors equipped with a stirring blade and a reflux condenser. The polymerization mixture contained 28.91 parts by mass (0.198 mol) of ISB, 58.24 parts by mass (0.294 mol), 106.25 parts by mass (0.496 mol), and 8.7 × 10 calcium acetate monohydrate as a catalyst. -4 Part of mass (4.94×10 -6 mol) was charged into a reactor. After purging the reactor with nitrogen under reduced pressure, the raw materials were dissolved at 150°C for approximately 10 minutes while stirring. As the first stage of the reaction, the internal temperature was raised to 210°C after 40 minutes, and this temperature was maintained while simultaneously reducing the pressure. After reaching 210°C, nitrogen was introduced into the first reactor and the pressure was restored to 13.3 kPa in 90 minutes. After the pressure reached 210°C, nitrogen was introduced into the first reactor and the pressure was restored to atmospheric pressure. The oligomerized reaction liquid in the first reactor was then transferred to the second reactor. Next, the temperature and pressure were increased in the second reactor, and the internal temperature and pressure were increased to 220°C and 20 kPa in 40 minutes. The pressure was then further reduced to 2 kPa, and polymerization was allowed to proceed until the specified stirring power was reached. Once the specified power was reached, nitrogen was introduced into the reactor to restore the pressure. The resulting polycarbonate resin was extruded into water, and strands were cut to obtain pellets. This resin is designated "Resin-1." The mass ratio of the structural units derived from each monomer was ISB / TCDDM / DPC=28.5 / 57.7 / 13.9.

[0183] <Production Example 2: Resin-4> Polymerization was carried out using a batch polymerization apparatus consisting of two vertical stirred reactors equipped with stirring blades and reflux condensers. The polymerization mixture contained 91.67 parts by mass (0.297 mol) of BPTMC, 66.86 parts by mass (0.312 mol) of DPC, and 39.68 × 10 mol of CsCO as a catalyst. -4 Part of mass (2.97×10 -6mol) was charged into a reactor. The raw materials were dissolved with stirring at 150°C for approximately 10 minutes. As the first stage of the reaction, the internal temperature was raised to 220°C after 40 minutes, and this temperature was maintained while simultaneously depressurizing. After reaching 220°C, nitrogen was introduced into the first reactor and the pressure was restored to 13.3 kPa in 90 minutes. After the pressure reached 220°C, the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Next, the temperature and pressure in the second reactor were increased and the pressure was reduced to 250°C and 20 kPa in 40 minutes. The pressure was then further reduced, and polymerization proceeded until the specified stirring power was reached. Once the specified power was reached, nitrogen was introduced into the reactor to restore the pressure. The resulting aromatic polycarbonate resin was extruded into water, and the strands were cut to obtain pellets. This resin is designated "Resin-4." The mass ratio of structural units derived from each monomer was BPTMC / DPC = 91.7 / 8.3.

[0184] Example 1 700 parts by weight of pellets of Resin-1 obtained in Production Example 1, dried at 80°C for 12 hours, were blended with 300 parts by weight of Resin-2 pellets. The blend was then extrusion-kneaded using a vacuum-vented twin-screw extruder TEX30HSS (manufactured by The Japan Steel Works, Ltd.) at a cylinder temperature of 245-270°C and an extrusion rate of 10 kg / hr. The resulting resin was extruded into water, and the strands were cut at a speed of 290 r / min using an Isuzu Chemical Engineering Co., Ltd. SCR-100 plastics processing machine to obtain pellets of a polycarbonate resin composition. The resulting polycarbonate resin composition was subjected to the various evaluations described above. The results are shown in Table 1.

[0185] <Examples 2 to 6, Comparative Examples 1 to 6> The same operations as in Example 1 were carried out except that the composition was changed as shown in Table 1. Various properties were evaluated using the methods described above. The results are shown in Table 1. However, since PC10 in Comparative Example 4 was very brittle and could not be molded, evaluation items that could not be measured are marked as "unmeasurable."

[0186] [Table 1]

[0187] <Examples 7 and 8> A retardation film was produced by the above-mentioned method using the polycarbonate resin composition (PC1) produced in Example 1, and various evaluations were carried out. The results are shown in Table 2.

[0188] [Table 2]

[0189] <Examples 9 to 15> The polycarbonate resin compositions (PC1 and PC2) prepared in Examples 1 and 2 were used to prepare unstretched films or molded articles by the methods described above, and various evaluations were carried out. The results are shown in Table 3.

[0190] [Table 3]

[0191] As is clear from Tables 1 to 3, the polycarbonate resin compositions of the present invention (Examples 1 to 15) are excellent in transparency, optical properties, and heat resistance, and can be used in a variety of applications such as optical films and lenses.

Claims

1. a polycarbonate resin containing a structural unit (A) derived from a dihydroxy compound having a moiety represented by the following formula (1); and an aromatic polycarbonate resin containing a structural unit (B) represented by the following formula (2): 【Chemical 1】 (However, the moiety represented by the above formula (1) is —CH 2 -Except when it is part of O-H.) 【Chemistry 2】 (However, R in the above formula (2) １ ~R ８ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, and X is —C(CH ３ ) ２ represents a direct bond, a substituted or unsubstituted chain alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cyclic alkylene group having 6 to 20 carbon atoms, or an arylene group having 6 to 20 carbon atoms excluding a fluorene skeleton.

2. The polycarbonate resin composition according to claim 1, wherein the structural unit (A) is a structural unit represented by the following formula (3): 【Chemistry 3】

3. The polycarbonate resin composition according to claim 1, wherein the structural unit (B) is a structural unit represented by the following formula (4): 【Chemistry 4】

4. 2. The polycarbonate resin composition according to claim 1, wherein the polycarbonate resin composition has one glass transition temperature.

5. 2. The polycarbonate resin composition according to claim 1, further comprising 0.01 to 3.0% by mass of an ultraviolet absorber.

6. 2. The polycarbonate resin composition according to claim 1, which has a reduced viscosity at 20°C of 0.30 or more and 0.53 or less.

7. A molded article obtained by molding the polycarbonate resin composition according to any one of claims 1 to 6.

8. 8. The molded article according to claim 7, which has a total light transmittance of 85% or more.

9. The molded article according to claim 7, which has a light transmittance of 95% or less at a wavelength of 380 nm.

10. Photoelastic coefficient is 60 －１２ Pa －１ 8. The molded article according to claim 7, wherein:

11. A lens obtained by molding the polycarbonate resin composition according to any one of claims 1 to 6.

12. A film obtained by molding the polycarbonate resin composition according to any one of claims 1 to 6.

13. An optical film comprising the film of claim 12 .

14. A protective film comprising the film of claim 12.

15. A retardation film comprising the film according to claim 12.

16. The retardation film according to claim 15, wherein the in-plane retardation Re(550) is 100 nm to 600 nm.

17. 16. The retardation film according to claim 15, wherein the ratio of a retardation R450 measured at a wavelength of 450 nm to a retardation R550 measured at a wavelength of 550 nm satisfies the following formula (I): 0.98≦R450 / R550≦1.05 (I)

Images