JP2015129304A - Polycarbonate resin and transparent film comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarbonate resin excellent in toughness and melt film-forming property, and a transparent film.SOLUTION: The polycarbonate resin comprises: a structural unit (A) derived from a dihydroxy compound represented by formula (1), by 15 to 50 mol% with respect to the total of (A) and the following structural unit (B); a structural unit (B) derived from a dihydroxy compound having an ether ring including a plurality of oxygen atoms in the same ring, by 50 to 85 mol% with respect to the total of (A) and (B); and a structural unit (C) derived from a dihydroxy compound represented by formula (2):H-(O-R)-OH, by 0.01 to 30 parts by weight with respect to 100 parts by weight of the total of (A) and (B). A film is obtained by using the above polycarbonate resin.

Description

  The present invention relates to a polycarbonate resin and a transparent film comprising the same.

  Polycarbonate resin has characteristics such as transparency, heat resistance, and toughness. Therefore, a polycarbonate resin film that has been stretched in a uniaxial direction and optically uniaxial anisotropy has been developed as an optical film for optical compensation used in, for example, an STN mode liquid crystal display.

  In a liquid crystal display such as a transmissive color liquid crystal display device and a transflective or reflective color liquid crystal display device, an optical film capable of optical compensation at a wavelength in the visible light range that is visible to humans is required.

  Thus, in order to perform optical compensation in the entire visible light region, a retardation film is known in which the phase difference increases as the wavelength increases. For example, Patent Document 1 proposes a polycarbonate resin composed of a copolymer of a bisphenol A skeleton and a bisphenol fluorene skeleton. Patent Documents 2 and 3 propose a polycarbonate resin containing a fluorene-containing dihydroxy compound and spiroglycol. Patent Document 4 proposes a polycarbonate resin in which an aliphatic diol is copolymerized with fluorene-containing bisphenol and spiroglycol.

Japanese Patent No. 3325560 International Publication No. 2006/41190 Pamphlet International Publication 2008/156186 Pamphlet JP 2011-148942 A

  In recent years, in the field of transparent films including optical films such as retardation films used for video devices such as televisions and mobile devices such as mobile phones equipped with various liquid crystal display devices and EL display devices, cost In order to reduce the residual solvent and reduce the residual solvent, it is desired that the film be formed by a melt film forming method in which a resin is heated and melted without using a solvent, instead of using a conventional solution cast film forming method using a solvent. . In addition, it is desired to reduce the thickness of the film for weight reduction and cost reduction.

  However, since the polycarbonate resin disclosed in Patent Document 1 has a rigid polymer chain, the glass transition temperature is 230 ° C. or higher. Therefore, in order to form a polycarbonate resin into a film, a solvent casting method has to be used. Further, the polycarbonate resins disclosed in Patent Documents 2 and 3 have a high melt viscosity, inferior melt film-forming properties, and a drawback that the film is brittle.

  In addition, some of the polycarbonate resins disclosed in Patent Document 4 can be melt-cast, but the toughness of the film was not sufficient for further film thinning.

  An object of the present invention is to solve the above-described conventional problems and provide a polycarbonate resin excellent in toughness and a transparent film made of the polycarbonate resin.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors include a structural unit (A) derived from a dihydroxy compound represented by the following general formula (1) and a plurality of oxygen atoms in the same ring. The above-mentioned conventional problems are solved by a polycarbonate resin containing a specific amount of a structural unit (B) derived from a dihydroxy compound having an ether ring and a structural unit (C) derived from a dihydroxy compound represented by the following general formula (2). The inventors have found that this can be solved and have reached the present invention.

In the general formula (1), R ^{1 to} R ⁴ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted 6 to 20 carbon atoms. Represents a cycloalkyl group or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and X represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, substituted or unsubstituted 6 carbon atoms. Represents a cycloalkylene group having 20 carbon atoms or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and m and n are each independently an integer of 0 to 5.

H— (O—R ⁵ ) _p —OH (2)

In the general formula (2), R ⁵ represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, and p is an integer of 2 to 50.

That is, the gist of the present invention resides in the following [1] to [8].
[1] A structural unit (A) derived from the dihydroxy compound represented by the general formula (1), a structural unit (B) derived from a dihydroxy compound having an ether ring containing a plurality of oxygen atoms in the same ring, and And the structural unit (C) derived from the dihydroxy compound represented by the general formula (2), wherein the structural unit (A) is a total of the structural unit (A) and the structural unit (B). 15 mol% or more and 50 mol% or less, the structural unit (B) is 50 mol% or more and 85 mol% or less, and the structure is based on a total of 100 parts by weight of the structural unit (A) and the structural unit (B). A polycarbonate resin containing 0.01 to 30 parts by weight of the unit (C).

[2] The polycarbonate resin according to [1], wherein the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin is 2.5% by volume or more and 25% by volume or less.

[3] The polycarbonate resin according to [1] or [2], wherein the polycarbonate resin has a glass transition temperature of 90 ° C. or higher and 200 ° C. or lower.

[4] The polycarbonate resin according to any one of [1] to [3], wherein the reduced viscosity of the polycarbonate resin is 0.2 to 0.6 dl / g.

[5] A structural unit (A) derived from a dihydroxy compound represented by the following general formula (3), a structural unit (B) derived from a dihydroxy compound having an ether ring containing a plurality of oxygen atoms in the same ring, A structural unit (D) derived from one or more dihydroxy compounds selected from the group consisting of the dihydroxy compound represented by the general formula (2) and the dihydroxy compound represented by the following general formula (4), A polycarbonate resin having a volume fraction of the —OCH ₂ CH ₂ — structure of 2.5% by volume to 25% by volume.

In the general formula (3), R ^{6 to} R ⁹ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon atom having 6 to 20 carbon atoms. It represents a cycloalkyl group or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

HO—R ¹⁰ —OH (4)

In the general formula (4), R ¹⁰ represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms.

[6] A transparent film obtained by melt-molding the polycarbonate resin according to any one of [1] to [5] or a composition containing the polycarbonate resin.

[7] The transparent film according to [6], wherein the ratio of the retardation R450 measured at a wavelength of 450 nm and the retardation R550 measured at a wavelength of 550 nm satisfies the following formula (I).
0.5 <R450 / R550 <1.0 (I)

[8] A stretched film obtained by stretching the transparent film according to [6] or [7] in at least one direction.

  The polycarbonate resin of the present invention has the above specific composition. Therefore, the film formed from the polycarbonate resin has excellent toughness. In addition, the polycarbonate resin is excellent in melt film forming compatibility because it has a small increase in defects due to generation of foreign matters and bubbles due to heat during film formation, and coloration of the film is small even when the film is formed by a melt film forming method.

  Hereinafter, the present invention will be described in detail. The present invention is not limited to the embodiments described below, and can be implemented with various modifications within the scope of the gist thereof.

[Polycarbonate resin]
One aspect of the polycarbonate resin in the present invention is derived from a structural unit (A) derived from the dihydroxy compound represented by the general formula (1) and a dihydroxy compound having an ether ring containing a plurality of oxygen atoms in the same ring. And a structural unit (C) derived from the dihydroxy compound represented by the general formula (2).

  The ratio of the structural unit (A) to the structural unit (B) is such that the structural unit (A) is not less than 15 mol% and not more than 50% with respect to the total of the structural unit (A) and the structural unit (B). The structural unit (B) is 50 mol% or more and 85 mol% or less. If the structural ratio of the structural unit (A) and the structural unit (B) in the polycarbonate resin is within the specific range, the retardation film made of the polycarbonate resin is optically compensated at a wavelength in the visible light region. If this retardation film is used, a display with excellent display quality can be obtained.

  When the structural unit (A) is less than 15 mol% and the structural unit (B) exceeds 85 mol%, the retardation film made of the polycarbonate resin performs optical compensation at a wavelength in the visible light region. It becomes difficult to obtain a display with excellent display quality. On the other hand, when the structural unit (A) exceeds 50 mol% and the structural unit (B) is less than 50 mol%, the heat resistance may be lowered, and a dimensional change after coloring a transparent film or coloring may occur. May cause problems. Therefore, the ratio of the structural unit (A) to the structural unit (B) is such that the structural unit (A) is 15 mol% to 50 mol%, and the structural unit (B) is 50 mol% to 85 mol%. More preferably, the structural unit (A) is 20 mol% or more and 45 mol% or less, and the structural unit (B) is 55 mol% or more and 80 mol% or less.

  The polycarbonate resin contains 0.01 to 30 parts by weight of the structural unit (C) with respect to 100 parts by weight of the structural unit (A) and the structural unit (B) in total. When the content of the structural unit (C) is within the specific range, flexibility can be imparted to the polycarbonate resin, and a film excellent in toughness can be easily obtained.

  When the content of the structural unit (C) is less than 0.01 part by weight, the flexibility of the polycarbonate resin becomes insufficient, and there is a possibility that the toughness is inferior when formed into a film. Therefore, the content of the structural unit (C) is 0.01 parts by weight or more, and more preferably 0.1 parts by weight or more. On the other hand, when the content of the structural unit (C) exceeds 30 parts by weight, various physical properties such as a decrease in heat resistance of the polycarbonate resin and an increase in temperature dependency of retardation of the obtained film are obtained. May decrease. Therefore, the content of the structural unit (C) is 30 parts by weight or less, and more preferably 25 parts by weight or less.

Further, the polycarbonate resin of the -OCH ₂ CH ₂ - is preferably volume fraction of structure is 25 vol% 2.5 vol% or more. When the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin is within the specific range, the polycarbonate resin becomes more flexible, and a film having excellent toughness can be obtained more easily. Here, -OCH 2 _CH 2 _- volume fraction of structures, a dihydroxy compound comprising a structural unit of the polycarbonate resin of the present invention -OCH 2 _CH 2 _- employ dihydroxy compound having a structure, appropriately adjusting the amount By doing so, it can be controlled within the specific range. The dihydroxy compound having a —OCH ₂ CH ₂ — structure is not particularly limited. For example, among the dihydroxy compounds represented by the general formula (1), X is an alkylene group having 2 carbon atoms, and m or n is 1 The above-mentioned dihydroxy compound, the dihydroxy compound represented by the general formula (2), and the like can be employed.

Here, the volume fraction is calculated as the ratio of the occupied volume of the —OCH ₂ CH ₂ —structure to the total occupied volume of the structural unit (A), the structural unit (B), and the structural unit (C). be able to. In addition, although the occupied volume per 1 mol in each of these structural units (hereinafter sometimes referred to as molecular volume) will be described later, polymer property estimation software (Polymer-Design Tools (TM)) Version 1.1 is used. This is a value calculated under the temperature condition of 298K by the Bicerano method.

When the volume fraction of the —OCH ₂ CH ₂ — structure is less than 2.5% by volume, the effect of imparting flexibility due to the —OCH ₂ CH ₂ — structure may be difficult to be exhibited. Therefore, the volume fraction of the —OCH ₂ CH ₂ — structure is preferably 2.5% by volume or more, more preferably 5% by volume or more, and particularly preferably 10% by volume or more. On the other hand, when the volume fraction of the —OCH ₂ CH ₂ — structure exceeds 25% by volume, the effect of imparting flexibility due to the —OCH ₂ CH ₂ — structure starts to saturate, which is commensurate with the content. It becomes difficult to obtain the effect. In this case, the heat resistance is lowered, and the temperature dependence of the retardation of the obtained film may be increased. Therefore, the volume fraction of the —OCH ₂ CH ₂ — structure is preferably 25% by volume or less, and more preferably 20% by volume or less.

Another aspect of the polycarbonate resin of the present invention is a dihydroxy having a structural unit (A) derived from the dihydroxy compound represented by the general formula (3) and an ether ring containing a plurality of oxygen atoms in the same ring. Derived from a structural unit (B) derived from a compound, one or more dihydroxy compounds selected from the group consisting of the dihydroxy compound represented by the general formula (2) and the dihydroxy compound represented by the general formula (4) And a structural unit (D), and a volume fraction of the —OCH ₂ CH ₂ — structure is 2.5% by volume or more and 25% by volume or less.

  In another aspect of the polycarbonate resin of the present invention, the ratio between the structural unit (A) and the structural unit (B) is not particularly limited. For example, as in the above aspect, the structural unit (A) and the structural unit (B) The structural unit (A) may be 15 mol% or more and 50 mol% or less, and the structural unit (B) may be 50 mol% or more and 85 mol% or less with respect to the total with the structural unit (B). The ratio of the structural unit (A) to the structural unit (B) is such that the structural unit (A) is 20 mol% to 45 mol%, and the structural unit (B) is 55 mol% to 80 mol%. The following is more preferable.

  In another aspect of the polycarbonate resin of the present invention, the content of the structural unit (D) is not particularly limited. For example, similar to the above-described aspect, the total of the structural units (A) and (B) is 100. 0.01-30 weight part of said structural units (D) may be contained with respect to the weight part. Since the structural unit (D) has the same effect as the structural unit (C), if the content of the structural unit (D) is within the specific range, flexibility can be imparted to the polycarbonate resin, A film excellent in toughness can be easily obtained. The content of the structural unit (D) is preferably 0.01 parts by weight or more, and more preferably 0.1 parts by weight or more. On the other hand, the content of the structural unit (D) is preferably 30 parts by weight or less, and more preferably 25 parts by weight or less.

In another aspect of the polycarbonate resin of the present invention, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin is 2.5% by volume or more and 25% by volume or less. When the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin is within the specific range, the polycarbonate resin becomes more flexible and a film having excellent toughness can be easily obtained. Incidentally, -OCH 2 _CH 2 _- structure, for example, may be introduced as a structure derived from the structural unit (D), but is not limited thereto.

Here, as described above, the volume fraction is the occupied volume of the —OCH ₂ CH ₂ — structure relative to the total occupied volume of the structural unit (A), the structural unit (B), and the structural unit (D). The ratio can be calculated as

<Dihydroxy compound represented by the general formula (1)>
Examples of the dihydroxy compound represented by the general formula (1) include 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, -Bis (4-hydroxy-3-ethylphenyl) fluorene, 9,9-bis (4-hydroxy-3-n-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-isopropylphenyl) fluorene, 9,9-bis (4-hydroxy-3-n-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3- tert-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, 9,9-bis ( -Hydroxy-3-phenylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isobutylphenyl) fluorene, 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, 9,9-bis (4- (3-hydroxy-2,2- Dimethylpropoxy) phenyl) fluorene and the like, preferably 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis ( 4- (2-hydroxyethoxy) phenyl) fluorene and 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, particularly preferably 9,9-bis (4-hydroxyphenyl) ) Fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxye) Toxi) phenyl) fluorene.

<Dihydroxy compound represented by the general formula (3)>
Examples of the dihydroxy compound represented by the general formula (3) include 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, -Bis (4-hydroxy-3-ethylphenyl) fluorene, 9,9-bis (4-hydroxy-3-n-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-isopropylphenyl) fluorene, 9,9-bis (4-hydroxy-3-n-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3- tert-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, 9,9-bis ( -Hydroxy-3-phenylphenyl) fluorene and the like are exemplified, and preferably 9,9-bis (4-hydroxyphenyl) fluorene and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, particularly Preferred is 9,9-bis (4-hydroxy-3-methylphenyl) fluorene.

<Dihydroxy compound having an ether ring containing a plurality of oxygen atoms in the same ring>
Examples of the dihydroxy compound having an ether ring containing a plurality of oxygen atoms in the same ring include 2- (1,1-dimethyl-2-hydroxyethyl) -5-ethyl-5-hydroxymethyl-1,3. -Dioxane (hereinafter sometimes abbreviated as dioxane glycol), 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro- [5.5 ] A compound containing a dioxane skeleton such as -undecane (hereinafter sometimes abbreviated as spiroglycol), a compound containing a dioxolane skeleton, or the like can be used. Of these, dioxane glycol and spiroglycol are preferable, and spiroglycol is particularly preferable. The “ether ring” of the “dihydroxy compound having an ether ring” means a compound having an ether group in a cyclic structure and a structure in which the carbon constituting the cyclic chain is an aliphatic carbon.

<Dihydroxy compound represented by the general formula (2)>
Examples of the dihydroxy compound represented by the general formula (2) include polyoxyalkylene glycols such as diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, and polytrimethylene glycol. . The dihydroxy compound represented by the general formula (2) has excellent reactivity during polymerization, and by using the dihydroxy compound, the toughness of the resulting polycarbonate resin as a film can be improved. . Of the dihydroxy compounds represented by the general formula (2), it is preferable to use diethylene glycol, triethylene glycol, or polyethylene glycol having a number average molecular weight of 150 to 2000, and more preferably diethylene glycol. In addition, the dihydroxy compound represented by the said General formula (2) may be used individually by 1 type, and 2 or more types may be mixed and used for it.

<Dihydroxy compound represented by the general formula (4)>
Specific examples of the dihydroxy compound represented by the general formula (4) include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol. Of these, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol are preferable. In addition, the dihydroxy compound represented with the said General formula (4) may be used individually by 1 type, and 2 or more types may be mixed and used for it.

[Production method of polycarbonate resin]
The polycarbonate resin of the present invention can be produced by a generally used polymerization method, and the polymerization method may be either a solution polymerization method using phosgene or a melt polymerization method in which it reacts with a carbonic acid diester. A melt polymerization method in which no solvent residue remains is preferred.

[Physical properties of polycarbonate resin]
<Glass transition temperature>
The glass transition temperature of the polycarbonate resin of the present invention is preferably 90 ° C. or higher and 200 ° C. or lower, more preferably 100 ° C. or higher and 160 ° C. or lower, and particularly preferably 110 ° C. or higher and 150 ° C. or lower. If the glass transition temperature is excessively low, the heat resistance tends to deteriorate, and there is a possibility of causing a dimensional change after film formation. Also, as a retardation film, the image quality may be lowered when laminated with a polarizing plate. is there. If the glass transition temperature is excessively high, melt molding stability during film molding may be deteriorated, and transparency of the film may be impaired. The glass transition temperature of the polycarbonate resin of the present invention is measured by the method described in the Examples section below.

<Reduced viscosity>
The molecular weight of the polycarbonate resin of the present invention can be represented by a reduced viscosity. As described in the Examples section below, the reduced viscosity of the polycarbonate resin of the present invention was prepared by using methylene chloride as a solvent and precisely preparing a solution having a polycarbonate resin concentration of 0.6 g / dL. It is measured using an Ubbelohde viscosity tube at 20.0 ° C. ± 0.1 ° C. The reduced viscosity of the polycarbonate resin of the present invention is preferably 0.20 dL / g or more, more preferably 0.30 dL / g or more, and further preferably 0.35 dL / g or more. If the reduced viscosity of the polycarbonate resin is less than 0.20 dL / g, there may be a problem that the mechanical strength of the molded product is reduced.

  The reduced viscosity is preferably 0.60 dL / g or less, and more preferably 0.55 dL / g or less. If the reduced viscosity is larger than 0.60 dL / g, the fluidity during molding is lowered, resulting in a problem that productivity is lowered, or it is difficult to remove foreign matters in the polycarbonate resin by filtration. There is a possibility that the reduction of the quality of the molded product may be reduced due to difficulty in reduction or mixing of bubbles during molding.

<Melt viscosity>
The melt viscosity in the polycarbonate resin of the present invention is not particularly limited, but the melt viscosity at a temperature of 240 ° C. and a shear rate of 91.2 sec ⁻¹ is preferably 500 Pa · sec to 2500 Pa · sec, and preferably 800 Pa · sec to 2300 Pa ·. It is more preferable that it is sec or less, and it is more preferable that it is 900 Pa · sec or more and 2000 Pa · sec or less.

  If the melt viscosity of the polycarbonate resin is smaller than the above lower limit, there may be a problem that the mechanical strength of the molded product is reduced. On the other hand, if the melt viscosity is larger than the above upper limit value, the fluidity during molding is lowered and the productivity is lowered, or the molded product has an appearance due to air bubbles mixed in the molded product. There is a possibility that the problem may be reduced or it may be difficult to remove foreign matters in the polycarbonate resin by filtration or the like. The melt viscosity of the polycarbonate resin is measured by the method described in the Examples section below.

[Other additives]
<Ultraviolet absorber>
In order to further improve the weather resistance of the polycarbonate resin and transparent film of the present invention, an ultraviolet absorber can be blended. Examples of such UV absorbers include 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole and 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzo. Triazole, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2,2′- Examples include methylene bis (4-cumyl-6-benzotriazolephenyl), 2,2′-p-phenylenebis (1,3-benzoxazin-4-one) and the like. The melting point of the ultraviolet absorber is particularly preferably in the range of 120 to 250 ° C. When an ultraviolet absorber having a melting point of 120 ° C. or higher is used, fogging due to gas on the surface of the molded article is reduced and improved. Specifically, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- [2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl] benzotriazole, 2,2-methylenebis [4- (1,1 , 3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2-hydroxy-3,5-dicumylphenyl) benzotriazole, and other benzotriazole ultraviolet absorbers Among these, among them, in particular, 2- (2-hydroxy-3,5-dicumylphenyl) benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethyl) Tylbutyl) -6- (2H-benzotriazol-2-yl) phenol] is preferred. These ultraviolet absorbers may be used alone or in combination of two or more. The blending amount of the UV absorber is preferably 0.0001 parts by weight or more and 1 part by weight or less, based on 100 parts by weight of the polycarbonate resin used in the present invention. It is more preferable to mix | blend in the ratio of 0.5 weight part or less, and it is further more preferable to mix | blend in the ratio of 0.001 weight part or more and 0.2 weight part or less. If it is this range, a weather resistance can be improved, without producing the bleeding out to the surface of the ultraviolet absorber of a transparent film, and a mechanical characteristic fall.

<Hindered amine light stabilizer>
Moreover, a hindered amine light stabilizer can be mix | blended in order to further improve the weather resistance of the polycarbonate resin and the transparent film of the present invention. Such hindered amine light stabilizers include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis- (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, poly [[6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) Imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]], N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N -(1,2,2,6,6-pentamethyl-4-piperidylamino) -6-chloro-1,3,5-triazine condensate, dibutylamine, 1,3,5-triazine, N, N'- Bis (2,2,6,6) -tetrame Le 4-piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl) polycondensate butylamine, and the like. Of these, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis- (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate are preferred.

  The amount of the hindered amine light stabilizer is preferably 0.001 part by weight or more and 1 part by weight or less, based on 100 parts by weight of the polycarbonate resin used in the present invention, and 0.005 part by weight or more. More preferably, it is blended in a proportion of 0.5 parts by weight or less, particularly preferably in a proportion of 0.01 parts by weight or more and 0.2 parts by weight or less. By blending the hindered amine light stabilizer in such a range, the composition containing the polycarbonate resin of the present invention can be produced without causing bleed of the hindered amine light stabilizer to the polycarbonate resin surface and deterioration of mechanical properties of various molded products. The weather resistance of the molded product formed by molding can be improved.

  The polycarbonate resin and various additives of the present invention are produced by mixing the additive components simultaneously or in any order with a mixer such as a tumbler, V-type blender, Nauta mixer, Banbury mixer, kneading roll, or extruder. be able to. Furthermore, a nucleating agent, a flame retardant, an inorganic filler, an impact modifier, a foaming agent, a dye / pigment and the like that are usually used in the resin composition may be contained within a range not impairing the object of the present invention.

In the present embodiment, a molded product obtained by molding the above-described polycarbonate resin or a composition containing the polycarbonate resin is obtained. The molding method of the molded product is not particularly limited, but a melt molding method is preferable.
[Transparent film]
The transparent film of the present invention is formed by molding the polycarbonate resin or a composition containing the polycarbonate resin into a film shape.
[Method for producing transparent film]

<Method for forming transparent film>
In the present invention, a method for producing a transparent film using the polycarbonate resin or the composition containing the polycarbonate resin is not particularly limited, and a melt film-forming method such as a T-die molding method or an inflation molding method, cast Various film forming methods such as a coating method, a calendering method, a heat pressing method, a co-extrusion method, a co-melting method, and a multilayer extrusion method can be used. Among these film forming methods, it is preferable to use a melt film forming method from the viewpoint of productivity and reduction of residual solvent, and among the melt film forming methods, it is more preferable to use a T-die forming method or an inflation forming method.

When the transparent film of the present invention is formed by a melt film forming method, the forming temperature is preferably 265 ° C. or lower, more preferably 260 ° C. or lower, and further preferably 258 ° C. or lower. If the molding temperature is too high, there is a risk that defects due to the generation of foreign matters and bubbles in the transparent film will increase or the transparent film will be colored. However, if the molding temperature is too low, it becomes difficult to mold a transparent film and it may be difficult to produce a transparent film having a uniform thickness. Therefore, the lower limit of the molding temperature is usually preferably 200 ° C or higher, and 210 ° C or higher. Is more preferable, and 220 ° C. or higher is more preferable.
Here, the molding temperature of the transparent film is a temperature at the time of molding in the melt film-forming method, and is usually a value obtained by measuring the resin temperature at the die outlet for extruding the molten resin.

<Stretching method>
As described above, the transparent film of the present invention is preferably stretched in at least one direction. Any appropriate stretching method can be adopted as the method of stretching the transparent film depending on the purpose, and various stretching methods such as free end stretching / fixed end stretching / free end contraction / fixed end contraction are used alone. It can also be used simultaneously or sequentially. Preferably, a transverse uniaxial stretching method, a longitudinal and transverse simultaneous biaxial stretching method, a longitudinal and transverse sequential biaxial stretching method, and the like can be mentioned. As a means for stretching, any suitable stretching machine such as a tenter stretching machine or a biaxial stretching machine can be used.
As the stretching temperature of the transparent film, an appropriate value can be appropriately selected according to the purpose. The stretching of the transparent film is preferably performed in the range of Tg−20 ° C. to Tg + 30 ° C. with respect to the glass transition temperature (Tg) of the transparent film. By selecting such conditions, the phase difference value is likely to be uniform. Specifically, the stretching temperature is preferably 70 ° C to 230 ° C, more preferably 90 ° C to 200 ° C, and particularly preferably 100 ° C to 180 ° C.
The draw ratio of the transparent film can be appropriately selected according to the purpose. The draw ratio is preferably more than 1 time and 6 times or less, more preferably more than 1.5 times and 4 times or less, and particularly preferably more than 2.0 times and 3 times or less.

[Thickness of transparent film]
The thickness of the transparent film of the present invention varies depending on the use, but is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less. If the thickness is large, the amount of material used increases and it becomes difficult to control uniformity, and it cannot be adapted to equipment that requires precision, thinness, and homogeneity.
The lower limit of the thickness of the transparent film of the present invention is preferably 20 μm or more, more preferably 30 μm or more. If the thickness is too thin, handling of the film will be difficult, wrinkles may occur during production, and it may be difficult to bond with other films and sheets such as protective films, etc. If the film is thick, more resin is required, which may be inefficient and may increase the thickness of the product using the film.

[Physical properties of transparent film]
<Birefringence>
In the transparent film formed by molding the polycarbonate resin of the present invention, the birefringence is preferably 0.001 or more. In order to design a very thin film to be molded using the polycarbonate resin, it is preferable that the birefringence is high. Therefore, the birefringence is more preferably 0.002 or more. If the birefringence is less than 0.001, it is necessary to increase the thickness of the film excessively, so the amount of material used increases, and it becomes difficult to control homogeneity in terms of thickness, transparency, and phase difference. . Therefore, when the birefringence is less than 0.001, there is a possibility that the transparent film produced using the polycarbonate resin cannot be adapted to equipment that requires precision, thinness, and homogeneity.

<Refractive index>
In the transparent film formed by molding the polycarbonate resin of the present invention, the refractive index at the sodium d line (589 nm) is preferably 1.57 to 1.60. When this refractive index is less than 1.57, it may not have sufficient optical characteristics as a retardation film. On the other hand, when the refractive index exceeds 1.60, the reflectance increases and the light transmittance may be reduced.

In the transparent film of the present invention, it is preferable that the relationship between the refractive indexes nx and ny in two directions in the plane and the refractive index nz in the thickness direction satisfy any of the following formulas (II) to (IV).
nx> ny = nz (II)
nx>ny> nz (III)
nx>nz> ny (IV)

If the refractive index relationship is nx> ny = nz, a uniaxial retardation film such as a λ plate, λ / 2 plate, or λ / 4 can be obtained. It can be used for reflection hue correction of a transmissive display or an organic EL display.
If nx>ny> nz, it can be used as a viewing angle compensator for a liquid crystal display, particularly as a viewing angle compensator in the VA mode, for a type that compensates by one sheet or a type that compensates by two sheets. Further, similarly to the above, it can also be used as a reflection hue correction film.
If nx>nz> ny, it can be used as a viewing angle correction film for a polarizing plate or a viewing angle correction film for a circularly polarizing plate, and can also be used as a reflection hue correction film as described above. Further, not only the front but also the viewing angle can be compensated.

In the transparent film of the present invention, it is preferable that the relationship between the refractive indexes nx and ny in two directions in the plane and the refractive index nz and thickness d in the thickness direction satisfy the following formulas (V) and (VI).
NZ coefficient = (nx-nz) / (nx-ny) = 0.2-8 (V)
Δnd = (nx−ny) · d = 30 to 400 nm (VI)
By setting the NZ coefficient to the specific range, it is possible to produce various viewing angle compensation phase difference films and hue correction phase difference films.
On the other hand, when the NZ coefficient is less than 0.2, a very special manufacturing method is required, which may cause a problem that the accuracy of the NZ coefficient is poor and the productivity is lowered.
When the NZ coefficient exceeds 8, Rth = (nx−nz) · d becomes very large, and it is necessary to increase the thickness of the material in order to obtain desired optical characteristics. For this reason, there are disadvantages that the material cost is increased and the thickness and weight of a display panel using an optical film made of this material is increased.

Further, by setting Δnd in the above range, a λ / 2 or λ / 4 plate can be easily made.
On the other hand, when Δnd is less than 30 nm, a C-plate region which is a so-called negative uniaxial retardation film is formed. C-plate alone cannot be used to compensate the viewing angle of the display and requires another retardation film, which increases the total number of retardation films, making it difficult to reduce the thickness and cost. There is a risk that the problem of becoming.
On the other hand, when Δnd exceeds 400 nm, it is necessary to increase the thickness in order to obtain a high phase difference, which may cause a reduction in productivity and reliability.

<Phase difference>
In the transparent film of the present invention, the ratio (R450 / R550) of the retardation R450 measured at a wavelength of 450 nm and the retardation R550 measured at a wavelength of 550 nm preferably satisfies the following formula (I), and R450 / R550 is It is more preferably 0.7 or more and less than 1.0, and particularly preferably 0.75 or more and less than 0.97.
0.5 <R450 / R550 <1.0 (I)

  If the value of R450 / R550 is within the above specific range, the so-called reverse wavelength dispersion characteristic that the phase difference becomes smaller as the light with a shorter wavelength is developed, and an ideal phase difference characteristic is obtained at each wavelength in the visible region. be able to. For example, a retardation film having such a wavelength dependency as a ¼λ plate is manufactured and bonded to a polarizing plate, whereby a circularly polarizing plate or the like can be manufactured. A polarizing plate and a display device can be realized. On the other hand, when the ratio is out of this range, the wavelength dependency of the hue becomes large, and coloring problems occur in the polarizing plate and the display device.

<Transmissivity>
The transparent film of the present invention preferably has a total light transmittance of 80% or more, more preferably 90% or more, regardless of the thickness. If the transmittance is not less than the above lower limit, a transparent film with little coloring is obtained, and when it is bonded to a polarizing plate, it becomes a polarizing plate with a high degree of polarization and transmittance, and when it is combined with a display device, it has a high display quality. Can be realized. In addition, although the upper limit of the transmittance | permeability of the transparent film of this invention does not have a restriction | limiting in particular, The transmittance | permeability of the transparent film obtained using a substantial manufacturing facility is 99% or less normally.

[Usage]
There are no particular restrictions on the use of the transparent film of the present invention, but various liquid crystal display devices and liquid crystal display devices can be used by taking advantage of the fact that the phase difference is small even when used for a long time under high temperature conditions and the stability to temperature is excellent. It can be suitably used as an optical film such as a retardation film used in a video device such as a television or a mobile device such as a mobile phone equipped with an EL display device.
For example, a polarizing plate can be comprised by laminating | stacking the transparent film of this invention with a polarizer.
As the polarizer, various known configurations can be adopted. For example, a film prepared by adsorbing a dichroic substance such as iodine or a dichroic dye on various films by a conventionally known method, dyeing, crosslinking, stretching, and drying can be used.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by a following example, unless the summary is exceeded.
Below, the characteristic evaluation of polycarbonate resin and a transparent film was performed with the following method. The characteristic evaluation method is not limited to the following method and can be appropriately selected by those skilled in the art.

The abbreviations of the compounds used in the description of the following examples are as follows.
BCF: 9,9-bis (4-hydroxy-3-methylphenyl) fluorene [Osaka Gas Chemical Co., Ltd.]
・ SPG: Spiroglycol [Mitsubishi Gas Chemical Co., Ltd.]
・ 1,6-HDO: 1,6-hexanediol [manufactured by BASF]
・ 1,12-DDO: 1,12-dodecanediol [Wako Pure Chemical Industries, Ltd.]
CHDM: 1,4-cyclohexanedimethanol [New Nippon Rika Co., Ltd., trade name: SKY CHDM]
・ DEG: Diethylene glycol [Mitsubishi Chemical Corporation]
・ 1,4-BG: 1,4-Butanediol [Mitsubishi Chemical Corporation]
・ TEG: Triethylene glycol [Mitsubishi Chemical Corporation]
・ DPC: Diphenyl carbonate [Mitsubishi Chemical Corporation]

[Evaluation of polycarbonate resin]
(1) Glass transition temperature (Tig)
The measurement was performed using a differential scanning calorimeter (DSC 6220 manufactured by SII Nano Technology). About 10 mg of a polycarbonate resin sample was put in an aluminum pan manufactured by the same company and sealed, and the temperature was raised from room temperature to 250 ° C. at a temperature rising rate of 20 ° C./min under a nitrogen stream of 50 mL / min. After maintaining the temperature for 3 minutes, it was cooled to 30 ° C. at a rate of 20 ° C./min. The temperature was maintained at 30 ° C for 3 minutes, and the temperature was increased again to 200 ° C at a rate of 20 ° C / min. From the DSC data obtained at the second temperature increase, a straight line obtained by extending the base line on the low temperature side to the high temperature side, and a tangent line drawn at a point where the slope of the step change portion of the glass transition becomes maximum The extrapolated glass transition start temperature, which is the temperature of the intersection point, was determined and used as the glass transition temperature.

(2) Reduced Viscosity The reduced viscosity of the polycarbonate resin was measured at a temperature of 20.0 ° C. ± 0.1 ° C. using an Ubbelohde viscometer manufactured by Mori Yuri Chemical Co., Ltd., using methylene chloride as a solvent. The concentration was precisely adjusted to 0.6 g / dL.
From the passage time t _{0 of the} solvent and the passage time t of the solution, the following formula:
η _rel = t / t ₀
More seek relative viscosity eta _rel, from the relative viscosity eta _rel, the formula:
η _sp = (η−η ₀ ) / η ₀ = η _rel −1
The specific viscosity η _sp was determined.
By dividing the specific viscosity η _sp by the concentration c (g / dL), the following formula:
η _red = η _sp / c
From this, the reduced viscosity (converted viscosity) η _red was determined.
The higher this number, the greater the molecular weight.

(3) Volume fraction of —OCH ₂ CH ₂ — structure in polycarbonate resin Each structural unit at a temperature condition of 298 K using a polymer physical property estimation software (Polymer-Design Tools (TM)) Version 1.1 by Bicerano method The molecular volume of was calculated. As a result, molecular volume of the structural unit derived from BCF is 335cm ³ / mol, SPG molecular volume of the structural unit derived from the 277cm ³ / mol, molecular volume of the structural unit derived from the DEG 103cm ³ / mol, structural units derived from TEG Has a molecular volume of 142 cm ³ / mol, 1,6-HDO-derived structural unit has a molecular volume of 128 cm ³ / mol, 1,12-DDO-derived structural unit has a molecular volume of 251 cm ³ / mol, 1,4-BG The molecular volume of the derived structural unit was 87 cm ³ / mol, and the molecular volume of the —OCH ₂ CH ₂ — structure was 39 cm ³ / mol. Using these values and the composition of the polycarbonate resin, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin was calculated.

(4) Melt Viscosity Melt viscosity was measured using a Capillograph manufactured by Toyo Seiki Co., Ltd., model name CAPiroGRAPH1B, at a temperature of 250 ° C. and a shear rate of 91.2 sec ⁻¹ under conditions of an orifice length of 10 mm and an orifice hole diameter of 1 mm. .

[Evaluation of transparent film]
(1) Film thickness The thickness of the transparent film was measured using a contact-type thickness measuring device (product name “Dial Thickness Gauge SM-1201” manufactured by Teclock Co., Ltd.).

(2) Retardation Polycarbonate resin which has been vacuum-dried at 80 ° C. for 5 hours is formed into a film by a hot press molding machine to produce a film having a thickness of 150 μm ± 20 μm. In addition, the molding conditions of the hot press molding machine were appropriately adjusted in the range of a temperature of 200 to 250 ° C. and a pressure of 10 to 15 MPa. From this film, an unstretched film having a length of 125 mm and a width of 50 mm was cut out, and free end uniaxial stretching with a stretch ratio of 1.5 times was performed with a batch type biaxial stretching apparatus (manufactured by Island Kogyo Co., Ltd., strain rate of 1000% / min) Went. The stretching temperature is described in each example.

  For a sample obtained by cutting a uniaxially stretched transparent film into a width of 4 cm and a length of 4 cm, using a phase difference measuring device (product name “KOBRA WRXY2020” manufactured by Oji Scientific Instruments), a phase difference of 450 nm in a room at 23 ° C. R450 and retardation R550 at a wavelength of 550 nm were measured, and a ratio (R450 / R550) of the measured retardation R450 and retardation R550 was calculated, and the retardation R590 measured at a wavelength of 590 nm was calculated from the stretched film. Dividing by the thickness, birefringence Δn (590) was determined.

(3) Bending test As in the above (2), a polycarbonate resin that was vacuum dried at 80 ° C. for 5 hours was molded by a hot press molding machine to produce a film having a thickness of 150 μm ± 20 μm. A rectangular test piece having a length of 40 mm and a width of 10 mm was cut out.
The space between the left and right joint surfaces of the vise was opened to 40 mm, and both ends of the test piece were fixed in the joint surface. Next, the distance between the left and right joint surfaces is reduced at a speed of 2 mm / second or less, and the entire bent test piece is compressed within the joint surface while preventing the test piece from protruding outside the vise joint surface. did.
And when the test piece is bent into two pieces (or more than three pieces) at the bent part until the joint surfaces are completely in close contact, the movement of the joint surface of the vise is stopped and the distance between the joint surfaces is measured. did. Further, when the test piece was bent without breaking even when the joint surfaces were completely adhered, the thickness was set to 0 mm.
The same type of film was repeatedly tested 5 times, and the average value was adopted as a result of the bending test.

Example 1
Polymerization was carried out using a batch polymerization apparatus comprising two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100 ° C. BCF and SPG, DEG, DPC, and calcium acetate in a molar ratio of BCF / SPG / DEG / DPC / calcium acetate = 0.260 / 0.333 / 0.407 / 1.03 / 1.00 × 10 ⁻⁴ It was prepared to become. After sufficiently replacing the inside of the reactor with nitrogen (oxygen concentration 0.0005 to 0.001 vol%), heating was performed with a heating medium, and stirring was started when the internal temperature reached 100 ° C. After 40 minutes from the start of temperature increase, the internal temperature was reached to 220 ° C., and control was performed so as to maintain this temperature. At the same time, pressure reduction was started, and after reaching 220 ° C., the pressure reached 13.3 kPa in 90 minutes. The phenol vapor produced as a by-product with the polymerization reaction was led to a reflux condenser at 100 ° C., and a monomer component contained in a small amount in the phenol vapor was returned to the reactor, and the phenol vapor not condensed was led to a condenser at 45 ° C. and recovered.
Nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, and then the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Subsequently, the temperature increase and pressure reduction in the second reactor were started, and the internal temperature was changed to 255 ° C. and the pressure to 0.2 kPa in 50 minutes. Thereafter, polymerization was allowed to proceed until a predetermined stirring power was obtained. When a predetermined power was reached, nitrogen was introduced into the reactor and the pressure was restored. The reaction solution was extracted in the form of a strand and pelletized with a rotary cutter to obtain polycarbonate resin A.

The composition of the polycarbonate resin A is the structural unit derived from BCF / the structural unit derived from SPG = 43.8 mol% / 56.2 mol%, and the structural unit derived from BCF and the structural unit derived from SPG The content of the structural unit derived from DEG relative to 100 parts by weight in total was 21.6 parts by weight. Further, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin A was 18.9% by volume. Table 1 shows various physical property values such as glass transition temperature in the polycarbonate resin A having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. The stretching temperature of the stretched film used for measuring the phase difference was glass transition temperature + 12 ° C. The physical properties of the film are shown in Table 1.

(Example 2)
In Example 1, BCF, SPG, DEG, DPC, and calcium acetate were mixed at a molar ratio of BCF / SPG / DEG / DPC / calcium acetate = 0.280 / 0.395 / 0.325 / 1.05 / 1. It implemented like Example 1 except having prepared so that it might become 00 * 10 < ^-4 >.

The composition of the polycarbonate resin B obtained in this way is structural unit derived from BCF / structural unit derived from SPG = 41.5 mol% / 58.5 mol%, derived from the structural unit derived from BCF and SPG. The content of the structural unit derived from DEG with respect to 100 parts by weight in total with the structural unit to be 15.2 parts by weight. Further, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin B was 14.1% by volume. Table 1 shows various physical property values of the polycarbonate resin B having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. The stretching temperature of the stretched film used for measuring the phase difference was glass transition temperature + 12 ° C. The physical properties of the film are shown in Table 1.

(Example 3)
In Example 1, BCF, SPG, 1,6-HDO, DPC, and calcium acetate were mixed at a molar ratio of BCF / SPG / 1,6-HDO / DPC / calcium acetate = 0.300 / 0.410 / 0. It implemented like Example 1 except having prepared so that it might become 290 / 1.04 / 1.00 * 10 < ^-4 >.

The composition of the polycarbonate resin C obtained in this way is the structural unit derived from BCF / the structural unit derived from SPG = 42.3 mol% / 57.7 mol%, derived from the structural unit derived from BCF and SPG. The content of structural units derived from 1,6-HDO was 14.4 parts by weight with respect to a total of 100 parts by weight of the structural units. Further, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin C was 9.0% by volume. Table 1 shows various physical property values and measured values of the polycarbonate resin C having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. In addition, since this polycarbonate resin C was very fragile and cracked, a stretched film for measuring the phase difference could not be produced.

Example 4
In Example 1, BCF, SPG, TEG, DPC, and calcium acetate were mixed at a molar ratio of BCF / SPG / TEG / DPC / calcium acetate = 0.340 / 0.460 / 0.200 / 1.02 / 5. It implemented like Example 1 except having prepared so that it might become 00 * 10 < ^-4 >.

The composition of the polycarbonate resin F thus obtained is structural unit derived from BCF / structural unit derived from SPG = 42.5 mol% / 57.5 mol%, derived from the structural unit derived from BCF and SPG. The content of the structural unit derived from TEG with respect to 100 parts by weight in total with the structural unit to be 11.1 parts by weight. The volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin F was 8.7% by volume. Table 1 shows various physical property values and measured values of the polycarbonate resin F having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. The stretching temperature of the stretched film used for measuring the phase difference was glass transition temperature + 12 ° C. The physical properties of the film are shown in Table 1.

(Example 5)
In Example 1, BCF, SPG, 1,12-DDO, DPC, and calcium acetate were mixed at a molar ratio of BCF / SPG / 1,12-DDO / DPC / calcium acetate = 0.330 / 0.570 / 0. It implemented like Example 1 except having prepared so that it might become 100 / 1.02 / 5.00 * 10 < ^-4 >.

The composition of the polycarbonate resin G obtained in this way is structural unit derived from BCF / structural unit derived from SPG = 36.7 mol% / 63.3 mol%, derived from the structural unit derived from BCF and SPG. The content of the structural unit derived from 1,12-DDO was 6.8 parts by weight based on 100 parts by weight of the total structural unit. The volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin G was 2.7% by volume. Table 1 shows various physical property values and measured values in the polycarbonate resin G having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. The stretching temperature of the stretched film used for measuring the phase difference was glass transition temperature + 12 ° C. The physical properties of the film are shown in Table 1.

(Comparative Example 1)
In Example 1, BCF and SPG, DPC, and calcium acetate are mixed so that the molar ratio is BCF / SPG / DPC / calcium acetate = 0.340 / 0.660 / 1.05 / 1.00 × 10 ^−4. The same procedure as in Example 1 was performed except that the above was charged.

The composition of the polycarbonate resin D thus obtained was BCF-derived structural unit / SPG-derived structural unit = 34.0 mol% / 66.0 mol%. Further, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin D was 0.0% by volume. Table 1 shows various physical property values and measured values of the polycarbonate resin D having such a composition. In addition, since this polycarbonate resin D was very brittle, when producing a film using the hot press molding machine used for a bending test, the film was cracked and a test piece could not be produced in some cases. Therefore, the test piece which can be used for a bending test was selected from among the repeated productions, and the bending test was performed using this. Moreover, the stretched film for measuring a phase difference was not able to be manufactured.

(Comparative Example 2)
In Example 1, BCF and SPG, CHDM, DPC, and calcium acetate were mixed at a molar ratio of BCF / SPG / CHDM / DPC / calcium acetate = 0.340 / 0.310 / 0.350 / 1.05 / 1. It implemented like Example 1 except having prepared so that it might become 00 * 10 < ^-4 >.

The composition of the polycarbonate resin E thus obtained is structural unit derived from BCF / structural unit derived from SPG = 52.3 mol% / 47.7 mol%, derived from the structural unit derived from BCF and SPG. The content of the structural unit derived from CHDM was 22.6 parts by weight based on 100 parts by weight of the total structural unit. Further, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin E was 0.0% by volume. Table 1 shows various physical property values and measured values in the polycarbonate resin E having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. The stretched temperature of the stretched film used for measuring the phase difference was glass transition temperature + 14 ° C. The physical properties of the film are shown in Table 1.

(Comparative Example 3)
In Example 1, BCF, SPG, CHDM, DPC, and calcium acetate were mixed at a molar ratio of BCF / SPG / CHDM / DPC / calcium acetate = 0.340 / 0.610 / 0.050 / 1.02 / 5. It implemented like Example 1 except having prepared so that it might become 00 * 10 < ^-4 >.

The composition of the polycarbonate resin H obtained in this way is structural unit derived from BCF / structural unit derived from SPG = 35.8 mol% / 64.2 mol%, derived from the structural unit derived from BCF and SPG. The content of the structural unit derived from CHDM was 2.3 parts by weight with respect to 100 parts by weight in total with the structural unit. Further, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin H was 0.0% by volume. Table 1 shows various physical property values and measured values of the polycarbonate resin H having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. The stretching temperature of the stretched film used for measuring the phase difference was glass transition temperature + 12 ° C. The physical properties of the film are shown in Table 1.

(Comparative Example 4)
In Example 1, BCF, SPG, 1,4-BG, DPC, and calcium acetate were mixed at a molar ratio of BCF / SPG / 1,4-BG / DPC / calcium acetate = 0.340 / 0.580 / 0. It implemented like Example 1 except having prepared so that it might become 080 / 1.02 / 5.00 * 10 < ^-4 >.

The composition of the polycarbonate resin I obtained in this manner is the structural unit derived from BCF / the structural unit derived from SPG = 36.7 mol% / 63.0 mol%, derived from the structural unit derived from BCF and SPG. The content of structural units derived from 1,4-BG relative to 100 parts by weight in total with the structural units to be obtained was 2.4 parts by weight. Further, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin I was 2.2% by volume. Table 1 shows various physical property values and measured values of the polycarbonate resin I having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. In addition, since this polycarbonate resin I was very brittle and cracked, it was not possible to produce a stretched film for measuring the phase difference.

(Comparative Example 5)
In Example 1, BCF, SPG, 1,12-DDO, DPC, and calcium acetate were mixed at a molar ratio of BCF / SPG / 1,12-DDO / DPC / calcium acetate = 0.340 / 0.620 / 0. It implemented like Example 1 except having prepared so that it might become 040 / 1.02 / 5.00 * 10 < ^-4 >.

The composition of the polycarbonate resin J thus obtained is structural unit derived from BCF / structural unit derived from SPG = 35.4 mol% / 64.6 mol%, derived from the structural unit derived from BCF and SPG. The content of the structural unit derived from 1,12-DDO was 2.5 parts by weight with respect to 100 parts by weight in total with the structural unit. Further, the volume fraction of the —OCH ₂ CH ₂ — structure in the polycarbonate resin J was 1.4% by volume. Table 1 shows various physical property values and measured values of the polycarbonate resin J having such a composition. Furthermore, the transparent film was evaluated regarding the transparent film using this resin. The stretching temperature of the stretched film used for measuring the phase difference was glass transition temperature + 12 ° C. The physical properties of the film are shown in Table 1.

  In addition, the symbol “-” in Table 1 is a symbol indicating that the material is not used or has no unit.

  From the results shown in Table 1, it is clear that the transparent film made of the polycarbonate resin having the composition in the specific range is excellent in toughness.

Claims (8)

A structural unit (A) derived from a dihydroxy compound represented by the following general formula (1), a structural unit (B) derived from a dihydroxy compound having an ether ring containing a plurality of oxygen atoms in the same ring, Including the structural unit (C) derived from the dihydroxy compound represented by the formula (2), and the structural unit (A) is 15 mol% in the total of the structural unit (A) and the structural unit (B). 50 mol% or less, the structural unit (B) is 50 mol% or more and 85 mol% or less, and the structural unit (C) with respect to a total of 100 parts by weight of the structural unit (A) and the structural unit (B). ) In an amount of 0.01 to 30 parts by weight.

(In the general formula (1), R ^{1 to} R ⁴ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon atom having 6 to 20 carbon atoms. Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, X is a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, substituted or unsubstituted carbon number A cycloalkylene group having 6 to 20 carbon atoms or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, m and n are each independently an integer of 0 to 5).
H— (O—R ⁵ ) _p —OH (2)
(In the general formula (2), R ⁵ represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, and p is an integer of 2 to 50.) The polycarbonate resin of the -OCH ₂ CH ₂ - volume fraction of the structure is not more than 25 vol% 2.5 vol% or more, the polycarbonate resin of claim 1.   The polycarbonate resin according to claim 1, wherein the polycarbonate resin has a glass transition temperature of 90 ° C. or higher and 200 ° C. or lower.   The polycarbonate resin according to any one of claims 1 to 3, wherein the reduced viscosity of the polycarbonate resin is 0.2 to 0.6 dl / g. Structural unit (A) derived from a dihydroxy compound represented by the following general formula (3), structural unit (B) derived from a dihydroxy compound having an ether ring containing a plurality of oxygen atoms in the same ring, A structural unit (D) derived from one or more dihydroxy compounds selected from the group consisting of a dihydroxy compound represented by the formula (2) and a dihydroxy compound represented by the following general formula (4), -OCH ₂ A polycarbonate resin having a volume fraction of CH ₂ -structure of 2.5 vol% or more and 25 vol% or less.

(In said general formula (3), R < ⁶ > -R < ⁹ > is respectively independently a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C20. And a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.)
H— (O—R ⁵ ) _p —OH (2)
(In the general formula (2), R ⁵ represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, and p is an integer of 2 to 50.)
HO—R ¹⁰ —OH (4)
(In the general formula (4), R ¹⁰ represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms.)   A transparent film obtained by melt-molding the polycarbonate resin according to any one of claims 1 to 5 or a composition containing the polycarbonate resin. The transparent film according to claim 6, wherein the ratio of the retardation R450 measured at a wavelength of 450 nm and the retardation R550 measured at a wavelength of 550 nm satisfies the following formula (I).
0.5 <R450 / R550 <1.0 (I)   A stretched film obtained by stretching the transparent film according to claim 6 or 7 in at least one direction.