JP2017155187A - Polycarbonate resin, method for producing the polycarbonate resin, method for producing a transparent film comprising the polycarbonate resin, and retardation film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarbonate resin that is excellent in various characteristics such as heat resistance, optical properties and melt processability.SOLUTION: A polycarbonate resin containing at least a structural unit represented by the following formula. An oriented film prepared from said resin.SELECTED DRAWING: None

Description

  The present invention relates to a polycarbonate resin excellent in optical properties, heat resistance, melt processability, and the like, and a transparent film and a retardation film comprising the polycarbonate resin.

  In recent years, the demand for transparent resins used for optical applications such as optical lenses, optical films, and optical recording media has increased. Among them, thin flat panel displays (FPDs) represented by liquid crystal displays and organic EL displays are particularly widespread, improving display quality such as improving contrast and coloring, widening the viewing angle, and preventing external light reflection. Various optical films have been developed and used for the purpose.

  For example, in an organic EL display, a quarter wavelength plate for preventing reflection of external light is used. The retardation film used for the quarter-wave plate suppresses coloring and enables a clear black display, so that it is possible to obtain ideal retardation characteristics at each wavelength in the visible region. Is required. Corresponding to this, for example, a retardation film is disclosed which comprises a polycarbonate copolymer containing a bisphenol structure having a fluorene ring in the side chain, and exhibits reverse wavelength dispersion with a smaller retardation at shorter wavelengths ( For example, see Patent Documents 1 and 2).

  Conventional polycarbonate resins have been mainly used with bisphenol A as a monomer, but in recent years, polycarbonate resins having isosorbide (ISB) as a monomer component have been developed. Polycarbonate resins using ISB are excellent in various properties such as heat resistance and optical properties, and are being studied for use in optical applications such as retardation films and glass substitute applications (see, for example, Patent Documents 3 and 4). ). In addition, ISB is a dihydroxy compound obtained from biomass resources, and is also interested in being a carbon-neutral material that does not contribute to an increase in carbon dioxide emissions even when incinerated.

  Inositol is a cyclic polyhydric alcohol obtained from biomass resources, and is expected to form a polymer by linking with a compound that reacts with a hydroxy group. Non-Patent Documents 1 and 2 report that polyurethane was synthesized from an inositol derivative, and that heat resistance was improved.

Japanese Patent No. 3325560 Japanese Patent No. 5119250 Japanese Patent No. 5346449 JP 2012-214666 A

Journal of Polymer Science Part A 51.3956 (2013) Proceedings of the Society of Polymer Science 2013, 62, 396-398

  In recent years, in optical film applications such as retardation films, the optical properties and dimensions of the film should not change in processes involving heating during the assembly process of polarizing plates and displays, or in high-temperature and high-humidity environments. There is a demand for improved heat resistance of materials. In addition, there are also demands for further improvement of optical characteristics and quality, cost reduction, productivity improvement in each process such as film formation, stretching, and lamination. In order to satisfy these requirements, various characteristics are simultaneously improved. It needs to be excellent. Specifically, it improves heat resistance by improving the glass transition temperature, optical properties such as retardation wavelength dispersion, photoelastic coefficient, mechanical properties such as film toughness, and physical properties such as melt processability. There is a demand for the development of materials with excellent balance at a high level.

  An object of the present invention is to solve the above-mentioned various problems and to provide a polycarbonate resin excellent in various properties such as heat resistance, optical properties, melt processability, a method for producing the polycarbonate resin, and a transparent film comprising the polycarbonate resin. It is in providing a manufacturing method and retardation film.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention contain a specific structure and control the ratio with various copolymerization components, so that heat resistance, optical properties, melt processability, etc. The present inventors have found that a polycarbonate resin having excellent physical properties can be obtained, and have reached the present invention. That is, the gist of the present invention is as follows.

[1] A polycarbonate resin containing at least a structural unit represented by any of the following formulas (1) to (3), and a retardation (R450) and a wavelength at a wavelength of 450 nm of a stretched film made from the resin A polycarbonate resin having a wavelength dispersion (R450 / R550) value of 0.50 or more and 1.03 or less, which is a ratio to a phase difference (R550) at 550 nm.

(In the above formulas (1) to (3), R ^{1 to} R ⁴ each independently represents an organic group having 1 to 30 carbon atoms. These organic groups may have any substituent. Any two or more of R ^{1 to} R ⁴ may be bonded to each other to form a ring.)

[2] The polycarbonate resin according to [1], wherein R ¹ and R ² , R ³ and R ^{4 in the} formulas (1) to (3) each form a ring with an acetal bond.

[3] The polycarbonate resin according to [1] or [2], wherein the cyclohexane ring in the formulas (1) to (3) is an inositol residue derived from myo-inositol.

[4] The polycarbonate resin according to any one of [1] to [3], which includes at least a structural unit represented by the following formula (4).

[5] The polycarbonate resin according to any one of [1] to [4], which has a glass transition temperature of 100 ° C. or higher and 180 ° C. or lower.

[6] When the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight, the structural unit represented by any one of the formulas (1) to (3) is 1 weight. % Or more and 70% by weight or less of the polycarbonate resin according to any one of [1] to [5].

[7] When the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight, the structural unit represented by the following formula (5) is 1% by weight or more and 70% by weight or less. The polycarbonate resin according to any one of [1] to [6].

[8] When the total amount of all structural units constituting the resin and the weight of the linking group is 100% by weight, at least one structural unit selected from the following formulas (6) to (8) is 1% by weight. The polycarbonate resin according to any one of [1] to [7], which is contained in an amount of 70% by weight or less.

(In the above formula (6), R ^{5 to} R ⁸ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, wherein X is a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6 to 20 carbon atoms, or Represents 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).

(In formula (7) and (8), R < ⁹ > -R < ¹¹ > is a C1-C4 alkylene group which may have a direct bond and a substituent each independently, R < ¹² > -R < ¹⁷ >. Each independently has a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 4 to 10 carbon atoms, and a substituent. An optionally substituted acyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms which may have a substituent, an aryloxy group having 1 to 10 carbon atoms which may have a substituent, An optionally substituted acyloxy group having 1 to 10 carbon atoms, an amino group optionally having substituents, a vinyl group having 1 to 10 carbon atoms optionally having substituents, and a substituent An ethynyl group having 1 to 10 carbon atoms, a sulfur atom having a substituent, and a substituent. A silicon atom, a halogen atom, a nitro group, or a cyano group. However, may form a ring adjacent the at least two groups are bonded to each other among the R ¹² to R ^17.)

[9] Aliphatic dihydroxy compound, alicyclic dihydroxy compound, dihydroxy compound containing acetal ring, and oxy when the total amount of all structural units constituting the resin and the weight of the linking group is 100% by weight The polycarbonate resin according to any one of [1] to [8], which contains 0.1 wt% or more and 50 wt% or less of a structural unit derived from at least one compound selected from alkylene glycol.

[10] Aromatic structural units other than the structural units represented by the formulas (6) to (8) when the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight. The polycarbonate resin according to any one of [1] to [9], containing 5% by weight or less.

[11] The polycarbonate resin according to any one of [1] to [10], wherein the melt viscosity at a measurement temperature of 240 ° C. and a shear rate of 91.2 sec ⁻¹ is 1000 Pa · s or more and 7000 Pa · s or less.

[12] Residual amount of carbonic acid diester in the resin is 1 to 300 ppm by weight, and content of monohydroxy compound derived from carbonic acid diester is 1 to 1000 ppm by weight [1 ] To [11].

[13] A method for producing the polycarbonate resin according to any one of [1] to [12] by a melt polymerization reaction, wherein a maximum temperature of the melt polymerization reaction is 200 ° C. or more and 260 ° C. or less. A method for producing a polycarbonate resin.

[14] A transparent film formed by molding the polycarbonate resin according to any one of [1] to [12].

[15] A method for producing the transparent film according to [14], wherein the polycarbonate resin according to any one of [1] to [12] is molded by a melt film-forming method at a molding temperature of 280 ° C. or lower. Manufacturing method.

[16] A retardation film which is a unidirectional or bi-directional stretched film according to [14].

  According to the present invention, a polycarbonate resin excellent in various properties such as heat resistance, optical properties, and melt processability, and a transparent film and a retardation film comprising the polycarbonate resin are provided.

  DESCRIPTION OF EMBODIMENTS Embodiments of the present invention will be described in detail below. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention. The content is not limited.

  In the present invention, the “structural unit” means a partial structure sandwiched between adjacent linking groups in the polymer, a polymerization reactive group present at the terminal portion of the polymer, and the polymerization reactive group. A partial structure sandwiched between matching linking groups.

  In the present invention, the carbon number of various substituents refers to the total number of carbon atoms including the carbon number of the substituent when the substituent further has a substituent.

  In the present invention, the polycarbonate resin includes a polyester carbonate resin. The polyester carbonate resin refers to a polymer including a portion in which the structural unit constituting the polymer is linked not only by a carbonate bond but also by an ester bond.

  The polycarbonate resin of the present invention is a polycarbonate resin containing at least a structural unit represented by any of the following formulas (1) to (3), and has a retardation at a wavelength of 450 nm (R450) and a retardation at a wavelength of 550 nm (R550). Is a polycarbonate resin having a chromatic dispersion (R450 / R550) value of 0.50 or more and 1.03 or less.

(In the above formulas (1) to (3), R ^{1 to} R ⁴ each independently represents an organic group having 1 to 30 carbon atoms. These organic groups may have any substituent. Any two or more of R ^{1 to} R ⁴ may be bonded to each other to form a ring.)

[Structure and raw material of polycarbonate resin of the present invention]
(Dihydroxy Compound A)
In the polycarbonate resin of the present invention, when the total amount of all structural units constituting the polycarbonate resin and the weight of the linking group is 100% by weight, it is represented by any one of the above formulas (1) to (3). The content of the structural unit is preferably 1% by weight or more and 70% by weight or less. This ratio is more preferably 3% by weight or more and 60% by weight or less, further preferably 5% by weight or more and 50% by weight or less, and particularly preferably 8% by weight or more and 40% by weight or less. The structural units represented by the formulas (1) to (3) may be referred to as the structure (1), the structure (2), and the structure (3), respectively.

  When the content of the structures (1) to (3) is more than the above range, the heat resistance may be excessively increased or the resulting resin may be brittle. In addition, it is necessary to increase the reaction temperature and the reaction time in order to advance the polymerization reaction to a sufficient molecular weight, so that the polymer is thermally deteriorated, the color tone is significantly deteriorated, and the crosslinking proceeds. There is a risk of gelation. On the other hand, when the content of the structures (1) to (3) is less than the above range, the effect of improving heat resistance, which is a feature of the polycarbonate resin of the present invention, cannot be obtained sufficiently.

In the formula ^{(1) ~ (3),} R 1 ~R 4 are each independently a substituent having an optionally organic group having 1 to 30 carbon atoms also. Examples of the organic group having 1 to 30 carbon atoms of R ^{1 to} R ⁴ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, and an undecyl group. , Alkyl groups such as dodecyl group, cycloalkyl groups such as cyclopentyl group and cyclohexyl group, linear or branched chain alkenyl groups such as vinyl group, propenyl group and hexenyl group, cyclic alkenyl groups such as cyclopentenyl group and cyclohexenyl group Group, ethynyl group, methylethynyl group, alkynyl group such as 1-propionyl group, aryl group such as phenyl group, naphthyl group and toluyl group, alkoxyphenyl group such as methoxyphenyl group, aralkyl group such as benzyl group and phenylethyl group , Heterocyclic groups such as thienyl group, pyridyl group and furyl group. Among these, from the viewpoint of the stability of the polymer itself, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and the like are preferable. From the viewpoint of the balance between the optical characteristics and weather resistance of the polymer, heat resistance and mechanical properties, the alkyl group A cycloalkyl group is particularly preferred.

Further, when these organic groups have a substituent, there is no particular limitation as long as the excellent physical properties of the polycarbonate resin of the present invention are not significantly impaired. In addition to the groups, alkoxy groups, hydroxyl groups, amino groups, carboxyl groups, ester groups, halogen atoms, thiol groups, thioether groups, organosilicon groups, and the like can be given. The organic group of R ^{1 to} R ⁴ may have two or more of these substituents, and in this case, the two or more substituents may be the same or different.

Two or more, preferably two or three of R ^{1 to} R ⁴ may be bonded to each other to form a ring, and in particular, R ¹ and R ² , R ³ and R ⁴ are It is preferable from the viewpoint of improving the heat resistance of the polycarbonate resin that a ring is formed by an acetal bond.

In particular, among the structures (1) to (3), the structure (1) is preferable from the viewpoint of the heat resistance and optical properties of the polycarbonate resin. In particular, in the formula (1), R ¹ and R ² , It is preferable that R ³ and R ⁴ each form a ring with an acetal bond.

Examples of structures in which R ¹ and R ² , R ³ and R ⁴ form an acetal bond, and a structure in which an acetal bond forms a ring, are preferably represented by the following structural formula group Among these, a cyclohexylidene group is particularly preferable from the viewpoint of heat resistance and optical properties.

In particular, the structural unit contained in the polycarbonate resin of the present invention is the structure (1), and in the formula (1), R ¹ and R ² , R ³ and R ⁴ are acetal bonds of a cyclohexylidene group. And the structure represented by the following formula (4), which is a combination of inositol residues derived from myo-inositol with the cyclohexane ring of the main chain being easy to procure raw materials, heat resistance, etc. From the viewpoint of various physical properties, it is preferable.

The polycarbonate resin of the present invention may have only the structure (1), may have only the structure (2), may have only the structure (3), Any two of 1) to (3) may be included, and three structures (1) to (3) may be included at the same time. In the structures (1) to (3) of the polycarbonate resin of the present invention, R ^{1 to} R ^{4 in} each structure may be the same or different.

  The above structures (1) to (3) are dihydroxy compounds represented by the following formulas (1A), (2A) and (3A) as raw material dihydroxy compounds, respectively, in the method for producing a polycarbonate resin of the present invention described later. (Hereinafter, these may be referred to as “dihydroxy compound A”) can be introduced into the polycarbonate resin.

(In the formulas (1A) to (3A), R ^{1 to} R ⁴ have the same meanings as in the formulas (1) to (3), respectively.

  In the polycarbonate resin of the present invention, in particular, the cyclohexane ring in the structures (1) to (3) is preferably an inositol residue derived from inositol. Specific examples of the inositol include all-cis-inositol, epi-inositol, allo-inositol, muco-inositol, myo-inositol, neo-inositol, chiro-D-inositol, chiro-L-inositol, scyllo-inositol. However, from the viewpoint of easy availability of raw materials, it is an inositol residue derived from myo-inositol, that is, the structures (1) to (3) in the polycarbonate resin of the present invention are the polycarbonates of the present invention described later. In the resin production method, it is preferable to introduce myo-inositol and / or a derivative thereof as a raw material dihydroxy compound.

(Dihydroxy compound B)
The polycarbonate resin of the present invention preferably contains a structural unit represented by the following formula (5).

  The content of the structural unit represented by the formula (5) is 1% by weight or more and 70% by weight when the total amount of all the structural units constituting the polycarbonate resin and the weight of the linking group is 100% by weight. % Or less is preferable. This ratio is more preferably 10% by weight or more and 65% by weight or less, and particularly preferably 20% by weight or more and 60% by weight or less.

  When the content of the structural unit represented by the formula (5) is more than the above range, the heat resistance becomes excessively high, and the mechanical properties and melt processability are deteriorated. Further, since the structural unit represented by the formula (5) has a highly hygroscopic structure, when the content is excessively large, the water absorption rate of the resin becomes high, and the optical properties of the molded product in a high humidity environment are high. There is a concern that the physical properties may change or deformation or cracking may occur. On the other hand, when the content of the structural unit represented by the formula (5) is less than the above range, the heat resistance becomes insufficient, the high transmittance and the low photoelastic coefficient, which are the features of the polycarbonate resin of the present invention, and the like. The optical characteristics cannot be obtained.

  Examples of the dihydroxy compound capable of introducing the structural unit represented by the formula (5) include isosorbide (ISB), isomannide, and isoidet (hereinafter referred to as “dihydroxy compound B”) having a stereoisomeric relationship. There is). These may be used individually by 1 type and may be used in combination of 2 or more type. Among these, it is most preferable to use ISB from the viewpoint of availability and polymerization reactivity.

  The dihydroxy compound B may contain a stabilizer such as a reducing agent, an antioxidant, an oxygen scavenger, a light stabilizer, an antacid, a pH stabilizer or a heat stabilizer. In particular, since the dihydroxy compound B is easily altered under acidic conditions, it is preferable to include a basic stabilizer.

  Examples of the basic stabilizer include hydroxides, carbonates, phosphates, phosphites, hypophosphites of group 1 or group 2 metals in the long-period periodic table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). Acid salts, borates and fatty acid salts; tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium Basic ammonium compounds such as dimethylhydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide and butyltriphenylammonium hydroxide; Butylamine, triethylamine, morpholine, N-methylmorpholine, pyrrolidine, piperidine, 3-amino-1-propanol, ethylenediamine, N-methyldiethanolamine, diethylethanolamine, diethanolamine, triethanolamine, 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like; amine compounds, and di- ( tert-butyl) amine and hindered amine compounds such as 2,2,6,6-tetramethylpiperidine.

  The content of these basic stabilizers in the dihydroxy compound B is not particularly limited. However, since the dihydroxy compound B is unstable in an acidic state, the pH of the aqueous solution of the dihydroxy compound B containing the stabilizer is about 7. It is preferable to add a stabilizer.

  If the amount of the stabilizer is too small, the effect of preventing the alteration of the dihydroxy compound B may not be obtained. If the amount is too large, the modification of the dihydroxy compound B may be caused. The content is preferably 0001 to 0.1% by weight, more preferably 0.001 to 0.05% by weight.

  In addition, since the dihydroxy compound B easily absorbs moisture and gradually deteriorates due to oxygen, water should not be mixed in during storage or handling during manufacture, and a deoxygenating agent or a nitrogen atmosphere should be used. Is preferable.

(Fluorene monomer)
The polycarbonate resin of the present invention may contain a structural unit selected from structural units represented by the following formulas (6) to (8). In addition, the bifunctional monomer containing the structural unit represented by the following formulas (6) to (8) may be referred to as “fluorene monomer”. The structural units represented by the following formulas (7) and (8) may be referred to as “oligofluorene structural units”.

(In the above formula (6), R ^{5 to} R ⁸ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, wherein X is a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6 to 20 carbon atoms, or Represents 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).

(In formula (7) and (8), R < ⁹ > -R < ¹¹ > is a C1-C4 alkylene group which may have a direct bond and a substituent each independently, R < ¹² > -R < ¹⁷ >. Each independently has a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 4 to 10 carbon atoms, and a substituent. An optionally substituted acyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms which may have a substituent, an aryloxy group having 1 to 10 carbon atoms which may have a substituent, An optionally substituted acyloxy group having 1 to 10 carbon atoms, an amino group optionally having substituents, a vinyl group having 1 to 10 carbon atoms optionally having substituents, and a substituent An ethynyl group having 1 to 10 carbon atoms, a sulfur atom having a substituent, and a substituent. A silicon atom, a halogen atom, a nitro group, or a cyano group. However, may form a ring adjacent the at least two groups are bonded to each other among the R ¹² to R ^17.)

  By introducing these structural units, it becomes possible to adjust the wavelength dispersion (wavelength dependence) of the phase difference. Many polymers have a positive wavelength dispersion in which the phase difference increases as the wavelength decreases. However, the structural units represented by the above formulas (6) to (8) have a reverse wavelength that decreases as the wavelength decreases. Since it has dispersibility, it can be adjusted from flat wavelength dispersibility to reverse wavelength dispersibility according to the content of the structural units represented by the formulas (6) to (8).

  Although the expression of reverse wavelength dispersion by the structural units represented by the formulas (6) to (8) varies depending on the structure, in order to obtain the optimum wavelength dispersion characteristics as a retardation film, the formulas (6) to ( 8) The content of the structural unit represented by 8) is 1% by weight or more and 70% by weight or less when the total weight of all the structural units constituting the polycarbonate resin and the linking group is 100% by weight. Preferably, the content is 3% by weight or more and 60% by weight or less, more preferably 5% by weight or more and 50% by weight or less.

  If the content of the structural units represented by the formulas (6) to (8) in the resin is too small, the above-described effect due to the inclusion of these structural units cannot be sufficiently obtained. ) To (8) have a negative birefringence, so if the content in the resin is greater than the above range, the birefringence becomes too small and a desired phase difference is obtained. There is a risk of being lost. Moreover, since the ratio of other copolymerization components decreases, it may be difficult to adjust the balance of other properties such as heat resistance and mechanical properties.

  Specific examples of the dihydroxy compound used for introducing the structural unit represented by the formula (6) include 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-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.

  Among the above-mentioned dihydroxy compounds, 9,9-bis (4- (2-hydroxyethoxy) phenyl) from the viewpoint of excellent various properties such as heat resistance, optical physical properties, mechanical properties, and availability. Fluorene and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene are particularly preferred.

In R ⁹ and R ¹⁰ in the formulas (7) and (8), as the “optionally substituted alkylene group having 1 to 4 carbon atoms”, for example, the following alkylene groups may be employed. it can.
Linear alkylene group such as methylene group, ethylene group, n-propylene group, n-butylene group; methylmethylene group, dimethylmethylene group, ethylmethylene group, propylmethylene group, (1-methylethyl) methylene group, 1 -Methylethylene group, 2-methylethylene group, 1-ethylethylene group, 2-ethylethylene group, 1-methylpropylene group, 2-methylpropylene group, 1,1-dimethylethylene group, 2,2-dimethylpropylene group An alkylene group having a branched chain, such as 3-methylpropylene group. Here, the position of the branched chain in R ⁹ and R ¹⁰ is indicated by a number assigned so that the carbon on the fluorene ring side is in the first position.

The selection of R ⁹ and R ¹⁰ has a particularly important influence on the development of reverse wavelength dispersion. In the state where the fluorene ring in the fluorene-based monomer structure is oriented perpendicular to the main chain direction (stretching direction), the strongest reverse wavelength dispersion is exhibited. In order to bring the orientation state of the fluorene ring closer to the above state and to exhibit strong reverse wavelength dispersion, it is preferable to employ R ⁹ and R ¹⁰ having 2 to 3 carbon atoms on the main chain of the alkylene group. . When the number of carbon atoms is 1, surprisingly, reverse wavelength dispersion may not be exhibited. This may be because the orientation of the fluorene ring is fixed in a direction that is not perpendicular to the main chain direction due to the steric hindrance of the carbonate group or ester group that is the linking group of the oligofluorene structural unit. . On the other hand, when the number of carbon atoms is too large, the reverse wavelength dispersibility may be weakened due to weak fixation of the orientation of the fluorene ring. In addition, the heat resistance of the resin tends to decrease.

As shown in the above formulas (7) and (8), R ⁹ and R ¹⁰ are either an oxygen atom bonded to the fluorene ring at one end of the alkylene group and an oxygen atom or carbonyl carbon included in the linking group at the other end. Are connected. From the viewpoints of thermal stability, heat resistance, and reverse wavelength dispersion, it is preferable that the other end of the alkylene group is bonded to the carbonyl carbon. As will be described later, as the monomer having an oligofluorene structure, specifically, a diol or diester structure (hereinafter, the diester also includes a dicarboxylic acid) can be considered, but polymerization is preferably performed using the diester as a raw material. Further, from the viewpoint of facilitating production, it is preferable to employ the same alkylene group for R ⁹ and R ¹⁰ .

In R ¹¹ , as the “optionally substituted alkylene group having 1 to 4 carbon atoms”, for example, the following alkylene groups can be employed.
Linear alkylene group such as methylene group, ethylene group, n-propylene group, n-butylene group; methylmethylene group, dimethylmethylene group, ethylmethylene group, propylmethylene group, (1-methylethyl) methylene group, 1 -Methylethylene group, 2-methylethylene group, 1-ethylethylene group, 2-ethylethylene group, 1-methylpropylene group, 2-methylpropylene group, 1,1-dimethylethylene group, 2,2-dimethylpropylene group , An alkylene group having a branched chain such as a 3-methylpropylene group.

R ¹¹ preferably has 1 to 2 carbon atoms on the main chain of the alkylene group, and particularly preferably 1 carbon atom. When R ¹¹ having too many carbons on the main chain is employed, the fixation of the fluorene ring is weakened similarly to R ⁹ and R ¹⁰ , the reverse wavelength dispersion is decreased, the photoelastic coefficient is increased, and the heat resistance is decreased. Etc. may be caused. On the other hand, the smaller the number of carbons on the main chain, the better the optical properties and heat resistance, but the thermal stability deteriorates when the 9-positions of the two fluorene rings are connected by a direct bond.

The fluorene ring contained in the oligofluorene structural unit has a configuration in which all of R ^{12 to} R ¹⁷ are hydrogen atoms, or R ¹² and / or R ¹⁷ are a halogen atom, an acyl group, a nitro group, a cyano group, and a sulfo group. It is preferably any one selected from the group consisting of groups, and R ^{13 to} R ¹⁶ are any of hydrogen atoms. In the case of having the former configuration, the compound containing the oligofluorene structural unit can be derived from fluorene which is industrially inexpensive. In addition, in the case of having the latter configuration, the reactivity at the 9-position of the fluorene ring is improved, so that various induction reactions tend to be adaptable in the process of synthesizing the compound containing the oligofluorene structural unit. The fluorene ring is more preferably selected from the group in which all of R ^{12 to} R ¹⁷ are hydrogen atoms, or R ¹² and / or R ¹⁷ is a group consisting of a fluorine atom, a chlorine atom, a bromine atom, and a nitro group. It is more preferable that R ^{13 to} R ¹⁶ are any of hydrogen atoms, and a structure in which all of R ^{12 to} R ¹⁷ are hydrogen atoms is particularly preferable. By adopting the above-described configuration, the fluorene ratio can be increased, steric hindrance between fluorene rings hardly occurs, and desired optical characteristics derived from the fluorene ring tend to be obtained.

  Of the divalent oligofluorene structural units represented by the formulas (7) and (8), preferred structures are specifically represented by the formulas (A1) to (A6) exemplified in the following [A] group. And a structure having a skeleton.

  Examples of the monomer having an oligofluorene structural unit include a specific dihydroxy compound represented by the following formula (7A) and a specific diester represented by the following formula (8A).

(In the formulas (7A) and (8A), R ^{9 to} R ¹⁷ have the same meanings as in the formulas (7) and (8), respectively. A ¹ and A ² have a hydrogen atom or a substituent. An aliphatic hydrocarbon group having 1 to 18 carbon atoms which may be present, or an aromatic hydrocarbon group which may have a substituent, and A ¹ and A ² may be the same or different. Good.)

  As the monomer having a divalent oligofluorene structural unit, it is preferable to use a specific diester represented by the formula (8A). The specific diester has relatively better thermal stability than the specific dihydroxy compound represented by the formula (7A), and the fluorene ring in the polymer is oriented in a preferred direction, resulting in stronger reverse wavelength dispersion. There is a tendency to show sex. When the polycarbonate resin contains a diester structural unit, this resin is referred to as a polyester carbonate resin.

When A ¹ and A ^{2 in} the formula (8A) are a hydrogen atom or an aliphatic hydrocarbon group such as a methyl group or an ethyl group, the polymerization reaction may hardly occur under the polymerization conditions of the polycarbonate usually used. is there. Therefore, A ¹ and A ^{2 in} the formula (8A) are preferably aromatic hydrocarbon groups.

(Monomers having other structural units)
In the polycarbonate resin of the present invention, structural units other than the structural units described above may be included (hereinafter sometimes referred to as “other structural units”), and the monomer containing the other structural units includes: Examples include aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, dihydroxy compounds containing an acetal ring, oxyalkylene glycols, dihydroxy compounds containing aromatic components, diester compounds, and the like. Among these, from the viewpoint of increasing reaction efficiency, aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, dihydroxy compounds containing an acetal ring, oxyalkylene glycols, and dihydroxy compounds containing an aromatic component are preferable.

As the aliphatic dihydroxy compound, for example, the following dihydroxy compounds can be used.
Ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-heptanediol, 1,6-hexane Dihydroxy compounds of linear aliphatic hydrocarbons such as diol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol; dihydroxy compounds of branched aliphatic hydrocarbons such as neopentyl glycol and hexylene glycol Compound.

As the alicyclic dihydroxy compound, for example, the following dihydroxy compounds can be used.
1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, pentacyclopentadecane dimethanol, 2,6-decalin dimethanol, 1,5-decalindi Examples include dihydroxy compounds derived from terpene compounds such as methanol, 2,3-decalin dimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol, 1,3-adamantane dimethanol and limonene. Dihydroxy compounds that are primary alcohols of alicyclic hydrocarbons; 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantanediol, hydrogenated bisphenol A, 2,2,4,4- Tetramethyl-1,3-cyclobutane Illustrated in ol, dihydroxy compound is a secondary alcohol and tertiary alcohol alicyclic hydrocarbon.

  As the dihydroxy compound containing an acetal ring, for example, spiro glycol represented by the following structural formula (9), dioxane glycol represented by the following structural formula (10), and the like can be used.

As the oxyalkylene glycols, for example, the following dihydroxy compounds can be used.
Diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol.

As the dihydroxy compound containing an aromatic component, 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, 1,1-bis (4-hydroxyphenyl) -2-ethylhexane, 1,1-bis (4-hydroxyphenyl) decane, bis (4-hydroxy-3-nitro Phenyl) methane, 3,3-bis (4-hydroxyphenyl) pentane, 1,3-bis (2- (4-hydroxyphenyl) -2-propyl) benzene, 1,3-bis (2- (4-hydroxy) Phenyl) -2-propyl) benzene, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) sulfone, 2,4 ′ -Dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxy Aromatic bisphenol compounds such as 3-methylphenyl) sulfide, bis (4-hydroxyphenyl) disulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dichlorodiphenyl ether; 2,2-bis (4- (2-hydroxyethoxy) phenyl) propane, 2,2-bis (4- (2-hydroxypropoxy) phenyl) propane, 1,3-bis (2-hydroxyethoxy) benzene, 4,4′-bis A dihydroxy compound having an ether group bonded to an aromatic group such as (2-hydroxyethoxy) biphenyl and bis (4- (2-hydroxyethoxy) phenyl) sulfone.

As the diester compound, for example, the following dicarboxylic acids can be used.
Terephthalic acid, phthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-benzophenone dicarboxylic acid, 4,4'-diphenoxyethanedicarboxylic acid, 4,4 '-Diphenylsulfone dicarboxylic acid, aromatic dicarboxylic acid such as 2,6-naphthalenedicarboxylic acid; 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, decalin-2,6 -Alicyclic dicarboxylic acids such as dicarboxylic acids; aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and the like. These dicarboxylic acid components can be used as raw materials for polyester carbonate as the dicarboxylic acid itself, but depending on the production method, dicarboxylic acid esters such as methyl ester and phenyl ester, and dicarboxylic acids such as dicarboxylic acid halides. Derivatives can also be used as raw materials.

  From the viewpoint of optical properties, it is preferable to use the other structural units listed above that do not contain an aromatic component, but in order to balance the heat resistance and mechanical properties while ensuring the optical properties. In addition, it may be effective to incorporate an aromatic component into the main chain or side chain of the polymer. In this case, for example, an aromatic component can be introduced into the polymer by the other structural unit containing an aromatic structure. However, these structural units in the polycarbonate resin of the present invention, that is, the above formula ( The content of the aromatic structural unit other than the structural units represented by 6) to (8) is 100% by weight when the total amount of all the structural units constituting the polycarbonate resin and the weight of the linking group is 100% by weight. 5% by weight or less is preferable. When the amount of other structural units containing an aromatic structure increases, the photoelastic coefficient may be deteriorated.

  Monomers having other structural units listed above include 1,6-hexanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1,4-cyclohexanedimethanol, and tricyclodehydride. It is particularly preferable to use candimethanol, spiroglycol, 1,4-cyclohexanedicarboxylic acid, decalin-2,6-dicarboxylic acid (and its derivatives). Resins containing structural units derived from these monomers have an excellent balance of optical properties, heat resistance, mechanical properties, and the like.

  Since the polymerization reactivity of the diester compound is relatively low, it is more preferable not to use a diester compound other than the diester compound having an oligofluorene structural unit from the viewpoint of increasing the reaction efficiency.

  The dihydroxy compound and diester compound for introducing other structural units may be used alone or in combination of two or more according to the required performance of the resin to be obtained. The content of other structural units in the resin is 0.1% by weight or more and 50% by weight or less when the total amount of all the structural units constituting the polycarbonate resin and the weight of the linking group is 100% by weight. 1 wt% or more and 45 wt% or less is more preferable, and 3 wt% or more and 40 wt% or less is particularly preferable. The other structural units mainly play a role in adjusting the heat resistance of the resin and imparting flexibility and toughness. If the content is too small, the mechanical properties and melt processability of the resin will deteriorate, and the content will be high. If it is too high, heat resistance and optical properties may be deteriorated.

(Carbonated diester)
The linking group of the structural unit contained in the polycarbonate resin of the present invention is introduced by polymerizing a carbonic acid diester represented by the following formula (11).

(In Formula (11), A ³ and A ⁴ are each an aliphatic hydrocarbon group having 1 to 18 carbon atoms that may have a substituent, or an aromatic hydrocarbon group that may have a substituent. And A ³ and A ⁴ may be the same or different.)

A ³ and A ⁴ are preferably a substituted or unsubstituted aromatic hydrocarbon group, and more preferably an unsubstituted aromatic hydrocarbon group. Examples of the substituent of the aliphatic hydrocarbon group include an ester group, an ether group, an amide group, and a halogen atom. Examples of the substituent of the aromatic hydrocarbon group include an alkyl group such as a methyl group and an ethyl group. It is done.

  Examples of the carbonic acid diester represented by the formula (11) include diphenyl carbonate (hereinafter sometimes abbreviated as DPC), substituted diphenyl carbonate such as ditolyl carbonate, dimethyl carbonate, diethyl carbonate, and di-tert-. Dialkyl carbonates such as butyl carbonate are exemplified, but preferred are diphenyl carbonate and substituted diphenyl carbonate, and particularly preferred is diphenyl carbonate.

  Carbonic acid diesters may contain impurities such as chloride ions, and these impurities may inhibit the polymerization reaction or deteriorate the hue of the resulting resin. It is preferable to use a purified one.

Also, when performing polymerization reaction by using both the carbonic acid diester represented by formula wherein the diester monomer represented by (8A) Formula (11), A ^1, A ² and the of the formula (8A) When A ³ and A ^{4 in} formula (11) all have the same structure, the components that are eliminated during the polymerization reaction are the same, and the components can be easily recovered and reused. From the viewpoint of usefulness in the polymerization reaction and reuse, it is particularly preferred A ¹ to A ⁴ is a phenyl group. When A ^{1 to} A ⁴ are phenyl groups, the component that is eliminated during the polymerization reaction is phenol.

[Production conditions for polycarbonate resin of the present invention]
The polycarbonate resin of the present invention can be produced by a generally used polymerization method. For example, it can be produced using a solution polymerization method or an interfacial polymerization method using phosgene or a carboxylic acid halide, or a melt polymerization method in which a reaction is performed without using a solvent. Among these production methods, it is preferable to produce by a melt polymerization method that can reduce environmental burden because it does not use a solvent or a highly toxic compound, and is excellent in productivity.

  In addition, when a solvent is used for polymerization, the solvent may remain in the resin, and the plastic transition effect lowers the glass transition temperature of the resin, which causes quality fluctuations in processing steps such as molding and stretching described later. obtain. In addition, a halogen-based organic solvent such as methylene chloride is often used as the solvent. When the halogen-based solvent remains in the resin, the metal part is formed when a molded body using the resin is incorporated into an electronic device or the like. It can also cause corrosion. Since the resin obtained by the melt polymerization method does not contain a solvent, it is advantageous for stabilization of processing steps and product quality.

  When producing a polycarbonate resin by the melt polymerization method, the monomer having the above-mentioned structural unit, a carbonic acid diester, and a polymerization catalyst are mixed and subjected to an ester exchange reaction (also referred to as a polycondensation reaction) under melting. The reaction rate is increased while removing the desorbed components out of the system. At the end of the polymerization, the reaction proceeds to the target molecular weight under conditions of high temperature and high vacuum. When the reaction is completed, the molten resin is extracted from the reactor, and the polycarbonate resin of the present invention is obtained.

  In the polycondensation reaction, the reaction rate and the molecular weight of the resulting resin can be controlled by strictly adjusting the molar ratio of all dihydroxy compounds and all diester compounds used in the reaction. In the case of polycarbonate resin, the molar ratio of carbonic acid diester to the total dihydroxy compound is preferably adjusted to 0.90 to 1.10, more preferably 0.96 to 1.05, and 0.98 to 1 It is particularly preferable to adjust to 0.03. In the case of polyester carbonate resin, it is preferable to adjust the molar ratio of the total amount of carbonic diester and all diester compounds to all dihydroxy compounds to 0.90 to 1.10, and 0.96 to 1.05. It is more preferable to adjust to 0.98 to 1.03.

  If the molar ratio deviates greatly in the vertical direction, a resin having a desired molecular weight cannot be produced. Moreover, when the said molar ratio becomes small too much, the hydroxyl-group terminal of manufactured resin will increase and the thermal stability of resin may deteriorate. In addition, a large amount of unreacted dihydroxy compound remains in the resin, which may cause dirt on the molding machine and poor appearance of the molded product in the subsequent molding process. On the other hand, if the molar ratio becomes too large, the rate of transesterification reaction decreases under the same conditions, or the residual amount of carbonic acid diester or diester compound in the produced resin increases. Similarly, there may be a problem in the molding process.

  The melt polymerization method is usually performed in a multistage process of two or more stages. The polycondensation reaction may be carried out in two or more steps by changing the conditions sequentially using one polymerization reactor, or two or more steps by changing the respective conditions using two or more reactors. However, from the viewpoint of production efficiency, it is carried out using two or more, preferably three or more reactors. The polycondensation reaction may be any of a batch system, a continuous system, or a combination of a batch system and a continuous system, but a continuous system is preferred from the viewpoint of production efficiency and quality stability.

  In the polycondensation reaction, it is important to appropriately control the balance between temperature and pressure in the reaction system. If either one of the temperature and pressure is changed too quickly, unreacted monomers may be distilled out of the reaction system. As a result, the molar ratio between the dihydroxy compound and the diester compound changes, and a resin having a desired molecular weight may not be obtained.

  In addition, the polymerization rate of the polycondensation reaction is controlled by the balance between the hydroxy group end and the ester group end or carbonate group end. Therefore, particularly in the case of performing polymerization in a continuous manner, if the balance of the end groups varies due to the distillation of unreacted monomers, it is difficult to control the polymerization rate to be constant, and the variation in the molecular weight of the resulting resin may increase. There is. Since the molecular weight of the resin correlates with the melt viscosity, when the obtained resin is molded, the melt viscosity fluctuates, and there is a possibility that a molded product having a uniform dimension cannot be obtained.

  Further, when the unreacted monomer is distilled, not only the balance of the end groups but also the copolymer composition of the resin may be out of the desired composition, which may affect the mechanical properties and optical characteristics. In the retardation film obtained from the polycarbonate resin of the present invention, the wavelength dispersion of the retardation is controlled by the ratio of the fluorene-based monomer and other copolymerization components in the resin. There is a possibility that the same optical characteristics cannot be obtained.

  Hereinafter, the steps of the melt polycondensation reaction include a stage in which monomers are consumed to produce oligomers (first stage reaction), and a stage in which polymerization is advanced to a desired molecular weight to produce polymers (second stage). (Reaction)

  Specifically, the following conditions can be adopted as reaction conditions in the first stage reaction. That is, the internal temperature of the polymerization reactor is usually 130 ° C. or higher, preferably 150 ° C. or higher, more preferably 170 ° C. or higher, and usually 250 ° C. or lower, preferably 240 ° C. or lower, more preferably 230 ° C. or lower. Set. The pressure in the polymerization reactor (hereinafter, the pressure represents an absolute pressure) is usually 70 kPa or less, preferably 50 kPa or less, more preferably 30 kPa or less, and usually 1 kPa or more, preferably 3 kPa or more, more preferably. Set in the range of 5 kPa or more. The reaction time is usually set in the range of 0.1 hour or longer, preferably 0.5 hour or longer, and usually 10 hours or shorter, preferably 5 hours or shorter, more preferably 3 hours or shorter.

  The first-stage reaction is carried out while distilling out the generated monohydroxy compound derived from the diester compound to the outside of the reaction system. For example, when diphenyl carbonate is used as the carbonic acid diester, the monohydroxy compound distilled out of the reaction system in the first stage reaction is phenol.

  In the first stage reaction, the lower the reaction pressure, the more the polymerization reaction can be promoted. On the other hand, the unreacted monomer is increased in distillation. In order to achieve both suppression of distillation of unreacted monomer and promotion of reaction by reduced pressure, it is effective to use a reactor equipped with a reflux condenser. In particular, it is preferable to use a reflux condenser at the beginning of the reaction with a large amount of unreacted monomers.

  In the second stage reaction, the pressure of the reaction system is gradually decreased from the pressure of the first stage, and the monohydroxy compound generated subsequently is removed from the reaction system. Preferably it is 3 kPa or less, more preferably 1 kPa or less. The internal temperature is usually set in the range of 210 ° C. or higher, preferably 220 ° C. or higher, and usually 260 ° C. or lower, preferably 255 ° C. or lower. The reaction time is usually 0.1 hours or longer, preferably 0.5 hours or longer, more preferably 1 hour or longer, and usually 10 hours or shorter, preferably 5 hours or shorter, more preferably 3 hours or shorter. Set. In order to suppress side reactions such as coloring, thermal deterioration, and crosslinking, and to obtain a resin having good hue and thermal stability, the maximum internal temperature in all reaction stages is 260 ° C. or lower, preferably 255 ° C. or lower, more preferably Is preferably 250 ° C. or lower. In particular, when the dihydroxy compound A used in the present invention undergoes a polymerization reaction at an excessively high temperature, there is a concern that the polymer is decomposed to generate a branched component, and the resulting polymer is crosslinked and gelled. When the gel is generated, the mechanical properties of the obtained resin may be deteriorated, and when used in an optical application, it becomes a foreign substance and deteriorates the appearance quality of the product.

  The transesterification catalyst that can be used at the time of polymerization (hereinafter sometimes simply referred to as “catalyst” or “polymerization catalyst”) is very effective in the reaction rate and the color tone and thermal stability of the resin obtained by polycondensation. Can have a big impact. The catalyst is not limited as long as it can satisfy the transparency, hue, heat resistance, thermal stability, and mechanical strength of the produced resin. And basic compounds such as metal compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, amine compounds, and the like. Preferably, at least one metal compound selected from the group consisting of a metal of Group 2 of the long-period periodic table and lithium is used.

As the group 1 metal compound, for example, the following compounds can be employed, but other group 1 metal compounds can also be employed.
Sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, cesium bicarbonate, 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 tetraphenylborate, tetraphenyl Potassium borate, lithium tetraphenylborate, cesium tetraphenylborate, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, disodium hydrogen phosphate, hydrogen phosphate Potassium, 2 lithium hydrogen phosphate, 2 cesium hydrogen phosphate, 2 sodium phenyl phosphate, 2 potassium phenyl phosphate, 2 lithium phenyl phosphate, 2 cesium phenyl phosphate, sodium, potassium, lithium, cesium alcoholate, pheno Rate, disodium salt of bisphenol A, 2 potassium salt, 2 lithium salt, 2 cesium salt.
Among these, it is preferable to use a lithium compound from the viewpoint of polymerization activity and the hue of the resulting resin.

As the group 2 metal compound, for example, the following compounds can be employed, but other group 2 metal compounds can also be employed.
Calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, Magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate.
Among these, it is preferable to use a magnesium compound, a calcium compound, and a barium compound. From the viewpoint of polymerization activity and the hue of the resulting resin, it is more preferable to use a magnesium compound and / or a calcium compound, and to use a calcium compound. Most preferred.

  In addition, it is also possible to use a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, and an amine compound in combination with the above-mentioned Group 1 metal compound and / or Group 2 metal compound. However, it is particularly preferable to use at least one metal compound selected from the group consisting of a metal of Group 2 of the long-period periodic table and lithium.

  The amount of the polymerization catalyst used is usually 0.1 μmol to 300 μmol, preferably 0.5 μmol to 100 μmol, per 1 mol of all dihydroxy compounds used in the polymerization, as a metal amount. As the polymerization catalyst, when using at least one metal compound selected from the group consisting of metals of Group 2 of the long-period periodic table and lithium, particularly when using a magnesium compound and / or a calcium compound, the amount of metal is The polymerization catalyst is usually used in an amount of 0.1 μmol or more, preferably 0.3 μmol or more, particularly preferably 0.5 μmol or more, per 1 mol of the total dihydroxy compound. The amount of the polymerization catalyst used is preferably 30 μmol or less, preferably 20 μmol or less, particularly preferably 10 μmol or less, as the amount of metal.

  In addition, when a polyester carbonate resin is produced using a diester compound as a monomer, a titanium compound, a tin compound, a germanium compound, an antimony compound, a zirconium compound, lead, with or without the use of the basic compound. A transesterification catalyst such as a compound, an osmium compound, a zinc compound, or a manganese compound can also be used. The amount of these transesterification catalysts used is usually in the range of 1 μmol to 1 mmol, preferably in the range of 5 μmol to 800 μmol, particularly preferably in terms of the amount of metal with respect to 1 mol of all dihydroxy compounds used in the reaction. It is in the range of 10 μmol to 500 μmol.

  If the amount of the catalyst is too small, the polymerization rate is slowed down. Therefore, in order to obtain a resin having a desired molecular weight, the polymerization temperature must be increased accordingly. For this reason, there is a high possibility that the hue of the resulting resin will deteriorate, and the unreacted raw material may volatilize during the polymerization, causing the molar ratio of the dihydroxy compound and the diester compound to collapse and not reaching the desired molecular weight. There is. On the other hand, if the amount of the polymerization catalyst used is too large, undesirable side reactions may occur, which may lead to deterioration of the hue of the resulting resin and coloring or decomposition of the resin during molding.

  Among the group 1 metals, sodium, potassium, and cesium may adversely affect the hue when contained in the resin. And these metals may mix not only from the catalyst to be used but from a raw material or a reaction apparatus. Regardless of the source, the total amount of these metal compounds in the resin is preferably 2 μmol or less, preferably 1 μmol or less, more preferably 0.5 μmol or less, per 1 mol of the total dihydroxy compound as the metal amount.

  After the polycarbonate resin of the present invention is polymerized as described above, it is usually cooled and solidified, and pelletized with a rotary cutter or the like. The method of pelletization is not limited, but the polycarbonate resin is withdrawn from the final stage polymerization reactor in a molten state, cooled and solidified in the form of a strand to be pelletized, and melted from the final stage polymerization reactor. In the method of supplying polycarbonate resin to a single-screw or twin-screw extruder and melt-extruding, then cooling and solidifying to pelletize, or extracting the polycarbonate resin in a molten state from the polymerization reactor in the final stage, in the form of a strand For example, after cooling and solidifying and once pelletizing, a polycarbonate resin is again supplied to a single-screw or twin-screw extruder, melt-extruding, and then cooling and solidifying to pelletize.

[Preferable physical properties of the polycarbonate resin of the present invention]
The molecular weight of the polycarbonate resin of the present invention thus obtained can be represented by reduced viscosity. If the reduced viscosity of the resin is too low, the mechanical strength of the resulting molded product may be reduced. Therefore, the reduced viscosity is usually 0.20 dL / g or more, and preferably 0.25 dL / g or more. On the other hand, if the reduced viscosity of the resin is too large, the fluidity during molding decreases, and the productivity and moldability tend to decrease. Therefore, the reduced viscosity is usually 0.80 dL / g or less, preferably 0.70 dL / g or less, and more preferably 0.60 dL / g or less. The reduced viscosity is measured using a Ubbelohde viscometer at a temperature of 20.0 ° C. ± 0.1 ° C. with a sample concentration precisely adjusted to 0.6 g / dL using methylene chloride as a solvent.

  Since the reduced viscosity has a correlation with the melt viscosity of the resin, normally, the stirring power of the polymerization reactor, the discharge pressure of the gear pump that transfers the molten resin, and the like can be used as indicators for operation management. That is, when the indicated value of the operating device reaches the target value, the polymerization reaction is stopped by returning the pressure of the reactor to normal pressure or by extracting the resin from the reactor.

The melt viscosity of the polycarbonate resin of the present invention is preferably 1000 Pa · s or more and 7000 Pa · s or less under measurement conditions of a temperature of 240 ° C. and a shear rate of 91.2 sec ⁻¹ . The melt viscosity is further preferably 1500 Pa · s or more and 6500 Pa · s or less, and particularly preferably 2000 Pa · s or more and 6000 Pa · s or less. The melt viscosity is measured using a capillary rheometer (manufactured by Toyo Seiki Seisakusho). When the melt viscosity is within the above range, melt processing is possible in a temperature range that has sufficient mechanical properties and can suppress thermal degradation of the resin.

  The glass transition temperature of the polycarbonate resin of the present invention is preferably 100 ° C. or higher and 180 ° C. or lower. The glass transition temperature is more preferably 120 ° C. or higher and 175 ° C. or lower, and particularly preferably 130 ° C. or higher and 170 ° C. or lower. The glass transition temperature of the polycarbonate resin can be adjusted by the copolymerization ratio of the structural units used in the present invention and other structural units. If the glass transition temperature is excessively low, the heat resistance tends to deteriorate, and the reliability of various physical properties (optical properties, mechanical properties, dimensions, etc.) of the molded product in the use environment may be deteriorated. On the other hand, if the glass transition temperature is excessively high, the resin may become brittle, the melt processability may deteriorate, the dimensional accuracy of the molded product may deteriorate, or the transparency may be impaired.

  Specific measuring methods of the reduced viscosity, melt viscosity, and glass transition temperature of the polycarbonate resin of the present invention are as described in the Examples section below.

  When diester compounds are used in the polycondensation reaction, unreacted diester compounds and by-product monohydroxy compounds remain in the resin, so they volatilize during melt processing and become odors, deteriorating the working environment, and molding. It may contaminate the machine and impair the appearance of the molded product. When diphenyl carbonate (DPC), which is a particularly useful carbonic acid diester, is used, the by-produced phenol has a relatively high boiling point and is not sufficiently removed even by a reaction under reduced pressure, and tends to remain in the resin.

  The monohydroxy compound derived from a carbonic acid diester contained in the polycarbonate resin of the present invention is preferably 1000 ppm by weight or less, more preferably 700 ppm by weight or less, and particularly preferably 500 ppm by weight or less. The residual amount of carbonic acid diester in the polycarbonate resin of the present invention is preferably 300 ppm by weight or less, more preferably 200 ppm by weight or less, and particularly preferably 150 ppm by weight or less. In order to solve the above problems, the monohydroxy compound and the carbonic acid diester are preferably as low as possible, but it is difficult to make the residual amount in the resin zero by the melt polymerization method. Requires excessive effort. Usually, the above problems can be sufficiently suppressed by reducing the contents of the monohydroxy compound and the carbonic acid diester to 1 ppm by weight, respectively.

  In order to reduce low molecular components such as monohydroxy compounds derived from carbonic acid diester and carbonic acid diester remaining in the resin, the resin is devolatilized with an extruder, the pressure at the end of polymerization is 3 kPa or less, It is preferably 2 kPa or less, more preferably 1 kPa or less.

  When reducing the pressure at the end of the polymerization, if the pressure of the reaction is too low, the molecular weight will increase rapidly, making it difficult to control the reaction. It is preferable to produce by making the base end excessive and biasing the end group balance. The end group balance can be adjusted by the molar ratio of the total dihydroxy compound and the total diester compound.

  Specific methods for measuring the content of the monohydroxy compound derived from the carbonic acid diester of the polycarbonate resin of the present invention and the residual amount of the carbonic acid diester are as described in the Examples section below.

The polycarbonate resin of the present invention preferably has a refractive index (n _D ) of 1.48 to 1.56 at the sodium d line (589 nm). The refractive index (n _D ) is more preferably 1.49 to 1.55, and particularly preferably 1.50 to 1.54. The smaller the refractive index, the more the surface reflection of the retardation film can be suppressed, the total light transmittance can be improved, and the optical compensation effect is enhanced. When the polycarbonate resin of the present invention contains an aromatic structural unit in order to impart reverse wavelength dispersion, the refractive index is higher than that of a polycarbonate resin composed only of an aliphatic structural unit. The refractive index can be kept within the above range by minimizing the content of the group structural unit.

The photoelastic coefficient of the polycarbonate resin of the present invention is preferably 30 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 20 × 10 ⁻¹² Pa ⁻¹ or less, and 15 × 10 ⁻¹² Pa ⁻¹ or less. It is particularly preferred that When the photoelastic coefficient is excessively large, there is a possibility that the image quality is deteriorated such that the periphery of the screen is blurred white when the retardation film is bonded to the polarizing plate. This problem is particularly noticeable when used in large display devices and flexible displays. The photoelastic coefficient of the polycarbonate resin of the present invention is preferably 7 × 10 ⁻¹² Pa ⁻¹ or more from the viewpoint of increasing the degree of freedom in controlling other physical properties of the polycarbonate resin.

  By constituting the polycarbonate resin of the present invention with a structural unit represented by any one of the above formulas (1) to (3) and an aliphatic structural unit, and not using any other aromatic structural unit. As described above, the photoelastic coefficient can be kept low.

  Further, the polycarbonate resin of the present invention is a value of wavelength dispersion (R450 / R550) which is a ratio of a retardation (R450) at a wavelength of 450 nm and a retardation (R550) at a wavelength of 550 nm of a stretched film made from the resin. Is 0.50 or more and 1.03 or less. This wavelength dispersion (R450 / R550) will be described in the section of retardation film.

The specific measurement methods of the refractive index (n _D ), photoelastic coefficient, and wavelength dispersion (R450 / R550) of the polycarbonate resin of the present invention are as described in the Examples section below.

[Additive]
In the polycarbonate resin of the present invention, a heat stabilizer, an antioxidant, a catalyst deactivator, an ultraviolet absorber, a light stabilizer, a release agent, a dye, and an impact improvement which are usually used within the range not impairing the object of the present invention. An agent, an antistatic agent, a lubricant, a lubricant, a plasticizer, a compatibilizing agent, a nucleating agent, a flame retardant, an inorganic filler, a foaming agent and the like may be included.

(Heat stabilizer)
If necessary, the polycarbonate resin of the present invention can be blended with a heat stabilizer in order to prevent a decrease in molecular weight and a deterioration in hue during melt processing. Examples of such heat stabilizers include conventionally known hindered phenol heat stabilizers and / or phosphorus heat stabilizers.

As the hindered phenol compound, for example, the following compounds can be employed.
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-2′-hydroxybenzyl) -4-methylphenyl acrylate, 2,2 ′ -Methylene-bis- (4-methyl-6-tert-butylphenol), 2,2'-methylene-bis- (6-cyclohexyl-4-me Ruphenol), 2,2′-ethylidene-bis- (2,4-di-tert-butylphenol), tetrakis- [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) ) Propionate] -methane, 1,3,5-trimethyl-2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) benzene and the like. Among them, tetrakis- [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] -methane, n-octadecyl-3- (3 ′, 5′-di-tert- Butyl-4'-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) benzene is preferably used.

As the phosphorus compound, for example, the following phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof can be adopted, but phosphorus compounds other than these compounds can also be adopted. Is possible.
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, bis (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di tert-butylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, triphenyl phosphate, diphenyl monoorxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, 4, 4'-Biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl), dimethyl benzenephosphonate, diethyl benzenephosphonate, dipropyl benzenephosphonate.

  These heat stabilizers may be used alone or in combination of two or more.

  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 forming a film by the melt extrusion method, the heat stabilizer or the like may be added to the extruder to form a film, or the extruder may be used in advance to add the heat stabilizer or the like into the resin. Alternatively, a pellet or the like may be used.

  The amount of these heat stabilizers is preferably 0.0001 parts by weight or more, more preferably 0.0005 parts by weight or more, even more preferably 0.001 parts by weight or more, when the resin is 100 parts by weight. 1 part by weight or less is preferable, 0.5 part by weight or less is more preferable, and 0.2 part by weight or less is more preferable.

(Catalyst deactivator)
By adding an acidic compound to the polycarbonate resin of the present invention to neutralize and deactivate the catalyst used in the polymerization reaction, the color tone and thermal stability can be improved. As the acidic compound used as the catalyst deactivator, a compound having a carboxylic acid group, a phosphoric acid group, or a sulfonic acid group, or an ester thereof can be used. In particular, the following formula (12) or (13) It is preferable to use a phosphorus compound containing a partial structure represented by

  Examples of the phosphorus compound represented by the formula (12) or (13) include phosphoric acid, phosphorous acid, phosphonic acid, hypophosphorous acid, polyphosphoric acid, phosphonic acid ester, and acidic phosphoric acid ester. Among them, phosphorous acid, phosphonic acid, and phosphonic acid ester are more excellent in catalyst deactivation and coloring suppression effects, and phosphorous acid is particularly preferable.

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

  Examples of phosphonates include dimethyl phosphonate, diethyl phosphonate, bis (2-ethylhexyl) phosphonate, dilauryl phosphonate, dioleyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate, dimethyl methylphosphonate, diphenyl methylphosphonate, and ethylphosphonic acid. Diethyl, diethyl benzylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, dipropyl phenylphosphonate, diethyl (methoxymethyl) phosphonate, diethyl vinylphosphonate, diethyl hydroxymethylphosphonate, dimethyl (2-hydroxyethyl) phosphonate, p-methylbenzylphosphonate diethyl, diethylphosphonoacetic acid, diethylphosphonoacetic acid ethyl, diethylphosphonoacetic acid tert-butyl, (Robenzyl) diethyl phosphonate, diethyl cyanophosphonate, diethyl cyanomethylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethylphosphonoacetaldehyde diethyl acetal, diethyl (methylthiomethyl) phosphonate Can be mentioned.

  Acid phosphate esters include dimethyl phosphate, diethyl phosphate, divinyl phosphate, dipropyl phosphate, dibutyl phosphate, bis (butoxyethyl) phosphate, bis (2-ethylhexyl) phosphate, diisotridecyl phosphate, phosphate Examples include phosphoric acid diesters such as dioleyl, distearyl phosphate, diphenyl phosphate and dibenzyl phosphate, mixtures of diesters and monoesters, diethyl chlorophosphate, and zinc stearyl phosphate.

  These may be used alone or in a combination of two or more in any combination and ratio.

  If the amount of the phosphorus compound added to the resin is too small, the effects of catalyst deactivation and coloring suppression are insufficient, and if it is too much, the resin may be colored, or a durability test particularly under high temperature and high humidity. In this case, the resin is easily colored. The phosphorus compound is added in an amount corresponding to the amount of catalyst used in the polymerization reaction. The phosphorus compound is preferably 0.5 times mol or more and 5 times mol or less, and more preferably 0.7 times mol or more and 4 times mol or less with respect to 1 mol of the metal of the catalyst used in the polymerization reaction. Particularly preferred is 0.8 times mol or more and 3 times mol or less.

(Polymer alloy)
The polycarbonate resin of the present invention is an aromatic polycarbonate, aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic, amorphous polyolefin, ABS, AS, for the purpose of modifying properties such as mechanical properties and solvent resistance. It is good also as a polymer alloy formed by kneading | mixing with 1 type (s) or 2 or more types, such as synthetic resins, rubbers, etc., such as polylactic acid and polybutylene succinate.

  The additives and modifiers may be added to the resin used in the present invention simultaneously or in any order by a mixer such as a tumbler, V-type blender, nauter mixer, Banbury mixer, kneading roll, or extruder. Although it can manufacture by mixing, it is preferable to knead | mix by an extruder, especially a twin-screw extruder especially from a viewpoint of a dispersibility improvement.

[Transparent film and retardation film]
The transparent film of the present invention is formed by molding the polycarbonate resin of the present invention.
The retardation film of the present invention is formed by stretching the transparent film of the present invention in at least one direction.
Hereinafter, the transparent film of the present invention may be referred to as “unstretched film”.

(Method for producing unstretched film)
As a method of forming an unstretched film using the polycarbonate resin of the present invention, the resin is dissolved in a solvent and cast, and then the casting method for removing the solvent or the resin is melted without using the solvent. A melt film-forming method for forming a film can be employed. Specific examples of the melt film forming method include a melt extrusion method using a T-die, a calender molding method, a heat press method, a co-extrusion method, a co-melting method, a multilayer extrusion method, and an inflation molding method. The method for forming an unstretched film is not particularly limited. However, the casting method may cause a problem due to the residual solvent. Therefore, a T-die is preferably used because of the melt film-forming method, particularly ease of subsequent stretching treatment. The melt extrusion method used is preferred.

  When an unstretched film is formed by the melt film forming method, the forming temperature is preferably 280 ° C. or less, more preferably 270 ° C. or less, and particularly preferably 265 ° C. or less. When the molding temperature is too high, defects due to generation of foreign matters and bubbles in the obtained film may increase or the film may be colored. However, if the molding temperature is too low, the melt viscosity of the resin becomes too high, making it difficult to mold the original film, and it may be difficult to produce an unstretched film with a uniform thickness. The lower limit is usually 200 ° C. or higher, preferably 210 ° C. or higher, more preferably 220 ° C. or higher. In the present invention, the molding temperature is a temperature at the time of molding in the melt film-forming method, and is a value obtained by measuring the resin temperature at the die outlet for extruding the molten resin.

  Moreover, when a foreign material exists in a film, when it is used as a polarizing plate, it will be recognized as a defect such as light leakage. In order to remove foreign substances in the resin, a method in which a polymer filter is attached after the extruder, the resin is filtered, and then extruded from a die to form a film is preferable. At that time, it is necessary to connect the extruder, polymer filter, and die with piping and transfer the molten resin, but in order to suppress thermal deterioration in the piping as much as possible, arrange each facility so that the residence time is minimized. This is very important. Further, the steps of conveying and winding the film after extrusion are performed in a clean room, and the best care is required so that no foreign matter adheres to the film.

  The thickness of the unstretched film is determined according to the design of the film thickness of the retardation film after stretching and stretching conditions such as the stretching ratio. Is usually 30 μm or more, preferably 40 μm or more, more preferably 50 μm or more, and usually 200 μm or less, preferably 160 μm or less, more preferably 120 μm or less. In addition, if there is unevenness in the thickness of the unstretched film, it causes retardation in the retardation film. Therefore, the thickness of the portion used as the retardation film is preferably set thickness ± 3 μm or less, and set thickness ± 2 μm or less. It is more preferable that the thickness is set to be ± 1 μm or less.

  The length of the unstretched film in the longitudinal direction is preferably 500 m or more, more preferably 1000 m or more, and particularly preferably 1500 m or more. From the viewpoint of productivity and quality, when producing the retardation film of the present invention, it is preferable to continuously stretch, but usually it is necessary to adjust the conditions to match the predetermined retardation at the start of stretching. If the length of the film is too short, the amount of product that can be obtained after adjusting the conditions is reduced. In the present specification, the term “long” means that the dimension in the longitudinal direction is sufficiently larger than the width direction of the film, and is substantially capable of being coiled by being wound in the longitudinal direction. means. More specifically, it means that the dimension in the longitudinal direction of the film is 10 times or more larger than the dimension in the width direction.

  The unstretched film obtained as described above preferably has an internal haze of 3% or less, more preferably 2% or less, and particularly preferably 1% or less. If the internal haze of the unstretched film is larger than the upper limit, light scattering occurs, which may cause depolarization when laminated with a polarizer, for example. The lower limit value of the internal haze is not particularly defined, but is usually 0.1% or more. For the measurement of internal haze, the transparent film with adhesive that had been previously measured for haze was attached to both sides of the unstretched film, and the sample with the effect of external haze removed was used. The value obtained by subtracting the haze value from the measured value of the sample is defined as the internal haze value.

  Further, the b * value of the unstretched film is preferably 3 or less. If the b * value of the film is too large, problems such as coloring occur. The b * value is more preferably 2 or less, particularly preferably 1 or less. The b * value is measured using a spectrocolorimeter CM-2600d manufactured by Konica Minolta.

The unstretched film preferably has a total light transmittance of 80% or more, more preferably 85% or more, and particularly preferably 90% or more, regardless of the thickness. If the total light transmittance is equal to or higher than the lower limit, a film with little coloration is obtained, and when bonded to a polarizing plate, it becomes a circularly polarizing plate having a high degree of polarization and transmittance, and is high when used in an image display device. Display quality can be realized. The upper limit of the total light transmittance of the unstretched film is not particularly limited, but is usually 99% or less.
A specific method for measuring the total light transmittance of the unstretched film is as described in the Examples section below.

(Method for producing retardation film)
A retardation film can be obtained by stretching and orienting the unstretched film in at least one direction. As the stretching method, a known method such as longitudinal uniaxial stretching, lateral uniaxial stretching using a tenter or the like, or simultaneous biaxial stretching and sequential biaxial stretching in combination thereof can be used. Stretching may be performed batchwise, but it is preferable in terms of productivity to be performed continuously. Further, a continuous retardation film with less variation in retardation within the film surface can be obtained compared to a batch system.

  The stretching temperature is usually in the range of (Tg-20 ° C) to (Tg + 30 ° C), preferably (Tg-10 ° C) to (Tg + 20 ° C), with respect to the glass transition temperature (Tg) of the resin used as a raw material. More preferably, it exists in the range of (Tg-5 degreeC)-(Tg + 15 degreeC). Although the draw ratio is determined by the target retardation value, it is 1.2 to 4 times, more preferably 1.5 to 3.5 times, and more preferably 2 to 3 times in the longitudinal and lateral directions. . When the draw ratio is too small, the effective range in which the desired degree of orientation and orientation angle can be obtained becomes narrow. On the other hand, if the stretch ratio is too large, the film may be broken or wrinkles may occur during stretching.

The stretching speed is also appropriately selected according to the purpose, but is usually 50% to 2000%, preferably 100% to 1500%, more preferably 200% to 1000%, and particularly preferably 250 at the strain rate represented by the following mathematical formula. % To 500% can be selected. If the stretching speed is excessively high, breakage during stretching may be caused, or fluctuations in optical characteristics due to long-term use under high temperature conditions may increase. Further, when the stretching speed is excessively low, not only the productivity is lowered, but also the stretching ratio may have to be excessively increased in order to obtain a desired phase difference.
Strain rate (% / min) = {Stretching rate (mm / min) /
Original film length (mm)} × 100

  After stretching the film, a heat setting treatment may be performed by a heating furnace as necessary, or the relaxation step may be performed by controlling the width of the tenter or adjusting the roll peripheral speed. The temperature of the heat setting treatment is usually 60 ° C. to (Tg), preferably 70 ° C. to (Tg−5 ° C.) with respect to the glass transition temperature (Tg) of the resin used for the unstretched film. If the heat treatment temperature is too high, the orientation of the molecules obtained by stretching is disturbed, and there is a possibility that the desired retardation will be greatly reduced. Moreover, when providing a relaxation process, the stress which arose in the stretched film can be removed by shrink | contracting to 95%-99% with respect to the width | variety of the film expanded by extending | stretching. The treatment temperature applied to the film at this time is the same as the heat setting treatment temperature. By performing the heat setting process and the relaxation process as described above, it is possible to suppress fluctuations in optical characteristics due to long-term use under high temperature conditions.

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

  A specific method for measuring the birefringence (Δn) of the retardation film is as described in the section of Examples described later.

  The retardation film of the present invention preferably has a thickness of 70 μm or less, although it depends on the design value of the retardation. Further, the thickness of the retardation film is more preferably 60 μm or less, further preferably 55 μm or less, and particularly preferably 50 μm or less. On the other hand, if the thickness is excessively thin, handling of the film becomes difficult, wrinkles occur during production, or breakage occurs. Therefore, the lower limit of the thickness of the retardation film of the present invention is preferably 10 μm or more, More preferably, it is 15 μm or more.

  The retardation film of the present invention, which is a stretched film made using the polycarbonate resin of the present invention, has a wavelength that is a ratio of a retardation measured at a wavelength of 450 nm (R450) to a retardation measured at a wavelength of 550 nm (R550). The value of dispersion (R450 / R550) is 0.50 or more and 1.03 or less. In applications where flat wavelength dispersion is suitably used, the value of wavelength dispersion (R450 / R550) is more preferably 0.98 or more and 1.02 or less, and 0.99 or more and 1.01 or less. It is particularly preferred. When used for a quarter-wave plate, the value of wavelength dispersion (R450 / R550) is more preferably 0.70 or more and 0.96 or less, and 0.75 or more and 0.94 or less. More preferably, it is 0.78 or more and 0.92 or less.

  If the value of the chromatic dispersion (R450 / R550) is within this range, an ideal phase difference characteristic can be obtained in a wide wavelength range in the visible region. For example, a retardation film having such wavelength dependency is prepared as a quarter wavelength plate, and a circularly polarizing plate or the like can be manufactured by laminating with a polarizing plate, and polarization with less hue wavelength dependency. A board and a display device can be realized. On the other hand, when the chromatic dispersion (R450 / R550) is out of this range, the wavelength dependence of the hue becomes large, optical compensation is not performed at all wavelengths in the visible region, and light passes through the polarizing plate and the display device. This causes problems such as coloring and a decrease in contrast.

[Usage]
The use of the transparent film of the present invention is not particularly limited, but the phase difference used in various liquid crystal display devices, mobile devices, etc. by taking advantage of excellent physical properties such as heat resistance, optical properties, and melt processability. Suitable for optical films such as films.

  For example, the retardation film of the present invention obtained by stretching the transparent film of the present invention is laminated and pasted with a known polarizing film and cut into a desired dimension to form a circularly polarizing plate. Such circularly polarizing plates are used, for example, for viewing angle compensation of various displays (liquid crystal display devices, organic EL display devices, plasma display devices, FED field emission display devices, SED surface field display devices), antireflection of external light, color Can be used for compensation, conversion of linearly polarized light into circularly polarized light, etc.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited by a following example, unless the summary is exceeded. The properties of the resin, transparent film (unstretched film) and retardation film of the present invention were evaluated by the following methods. The characteristic evaluation method is not limited to the following method and can be appropriately selected by those skilled in the art.

(1) Measurement of reduced viscosity A resin sample was dissolved in methylene chloride to prepare a resin solution having a concentration of 0.6 g / dL precisely. Measurement was performed at a temperature of 20.0 ° C. ± 0.1 ° C. using an Ubbelohde viscometer manufactured by Moriyu Rika Kogyo Co., Ltd., and a solvent passage time t ₀ and a solution passage time t were measured. The relative viscosity η _rel was obtained from the following equation (i) using the obtained values t ₀ and t, and the specific viscosity η _sp was obtained from the following equation (ii) using the obtained relative viscosity η _rel . .
η _rel = t / t ₀ (i)
η _sp = (η−η ₀ ) / η ₀ = η _rel −1 (ii)
Thereafter, the reduced viscosity η _sp / c was determined by dividing the obtained specific viscosity η _sp by the concentration c [g / dL].

(2) Measurement of melt viscosity The pellet-shaped resin sample was vacuum-dried at 90 ° C for 5 hours or more. Measurement was performed using a capillary rheometer manufactured by Toyo Seiki Seisakusho, using the dried pellets. Measurement temperature was 240 ° C., measured melt viscosity between shear rate 9.12~1824sec ^-1, using a value of melt viscosity at 91.2sec ^-1. An orifice having a die diameter of φ1 mm × 10 mmL was used.

(3) Measurement of glass transition temperature (Tg) It measured using differential scanning calorimeter DSC6220 by SII Nanotechnology. About 10 mg of a resin sample was put in an aluminum pan manufactured by the same company, sealed, and heated from 30 ° C. to 250 ° C. at a temperature rising rate of 20 ° C./min in 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. A resin having a high glass transition temperature is excellent from the viewpoint of heat resistance.

(4) Measurement of content of monohydroxy compound and carbonic acid diester in polycarbonate resin About 1 g of resin sample is precisely weighed and dissolved in 5 mL of methylene chloride to form a solution, and then acetone is added so that the total amount becomes 25 mL. The reprecipitation process was performed. Next, the treatment liquid was measured by liquid chromatography.
The equipment and conditions used are as follows.
・ Device: manufactured by Shimadzu Corporation System controller: CBM-20A
Pump: LC-10AD
Column oven: CTO-10ASvp
Detector: SPD-M20A
Analysis column: Cadenza CD-18 4.6 mmφ × 250 mm
Oven temperature: 60 ° C
・ Detection wavelength: 220 nm
Eluent: A solution: 0.1% phosphoric acid aqueous solution, B solution: acetonitrile A / B = 50/50 (vol%) to A / B = 0/100 (vol%) gradient in 10 minutes, A / Hold for 5 minutes at B = 0/100 (vol%) Flow rate: 1 mL / min
Sample injection volume: 10 μL
The content of each compound in the resin was prepared by preparing solutions with different concentrations for each compound, creating a calibration curve by performing measurement under the same conditions as the above liquid chromatography, and calculating by the absolute calibration curve method .

(5) Molding of unstretched film Resin pellets that had been vacuum-dried at 90 ° C. for 5 hours or longer were subjected to a single screw extruder (screw diameter 25 mm, cylinder set temperature: 220 ° C. to 260 ° C.) manufactured by Isuzu Chemical Industries, Ltd. Used and extruded from a T die (width 200 mm, set temperature: 200 to 260 ° C.). The extruded film was rolled by a winder while being cooled by a chill roll (set temperature: 120 to 170 ° C.), and an unstretched film having a thickness of 100 μm was produced. The preset temperature was adjusted within the preset temperature range according to the glass transition temperature and melt viscosity of the resin to be molded.

(6) Measurement of Refractive Index A rectangular test piece having a length of 40 mm and a width of 8 mm was cut out from the unstretched film produced by the above-described method to obtain a measurement sample. The refractive index (n _D ) was measured with a multi-wavelength Abbe refractometer DR-M4 / 1550 manufactured by Atago Co., Ltd., using an interference filter with a wavelength of 589 nm (sodium d line). The measurement was performed at 20 ° C. using monobromonaphthalene as the interfacial liquid.

(7) Measurement of total light transmittance About the unstretched film produced by the above-mentioned method, the total light transmittance was measured using Nippon Denshoku Industries Co., Ltd. turbidimeter COH400. A film having a high total light transmittance is excellent in terms of transparency.

(8) Measurement of photoelastic coefficient A device combining a birefringence measuring device comprising a He-Ne laser, a polarizer, a compensation plate, an analyzer and a photodetector and a vibration type viscoelasticity measuring device (DVE-3 manufactured by Rheology). (For details, see Journal of the Japan Rheological Society, Vol. 19, p93-97 (1991)). A resin having a low photoelastic coefficient has a small influence on the optical characteristics of a change in the shape of the film due to a change in temperature or humidity, and is excellent in terms of performance stability with respect to the environment.

A sample having a width of 5 mm and a length of 20 mm was cut out from the unstretched film produced by the method described above, fixed to a viscoelasticity measuring apparatus, and the storage elastic modulus E ′ was measured at a room temperature of 25 ° C. at a frequency of 96 Hz. At the same time, the emitted laser light is passed through the polarizer, sample, compensator, and analyzer in this order, picked up by a photodetector (photodiode), and passed through a lock-in amplifier with respect to the amplitude and distortion of the waveform of angular frequency ω or 2ω. The phase difference was determined, and the strain optical coefficient O ′ was determined. At this time, the directions of the polarizer and the analyzer were orthogonal to each other, and each was adjusted so as to form an angle of π / 4 with respect to the extending direction of the sample. The photoelastic coefficient C was obtained from the following equation using the storage elastic modulus E ′ and the strain optical coefficient O ′.
C = O '/ E'

(9) Measurement of birefringence (Δn) and wavelength dispersion (R450 / R550) A film piece having a width of 50 mm and a length of 125 mm was cut out from the unstretched film produced by the method described above. Using a batch-type biaxial stretching apparatus (biaxial stretching apparatus BIX-277-AL manufactured by Island Kogyo Co., Ltd.), the glass transition temperature of the resin + stretching temperature of 15 ° C., stretching speed of 300% / min, and 1.5 times The film piece was subjected to free end uniaxial stretching at a stretching ratio to obtain a retardation film. The center part of the stretched film obtained by the above method is cut into a width of 4 cm and a length of 4 cm, and measured using a phase difference measuring device KOBRA-WPR manufactured by Oji Scientific Instruments Co., Ltd., measurement wavelengths 450, 500, 550, 590, The phase difference was measured at 630 nm, and the wavelength dispersion was measured. The wavelength dispersion was shown by the ratio of the phase differences R450 and R550 measured at 450 nm and 550 nm (R450 / R550). When R450 / R550 is greater than 1, chromatic dispersion is positive, and when R450 / R550 is less than 1, chromatic dispersion is reversed. When used as a quarter wave plate, the ideal value of R450 / R550 is 0.818 (450/550 = 0.818).

Moreover, birefringence (DELTA) n was calculated | required from following Formula from phase difference R550 of 550 nm and the film thickness of a stretched film.
Birefringence = R550 [nm] / (film thickness [mm] × 10 ⁶ )
In this measurement, if Δn has a positive value, it can be used as a retardation film.

[Example of monomer synthesis]
<Synthesis Example 1>
DL-2,3: 5,6-di-O-cyclohexylidene-myo-inositol (hereinafter abbreviated as “DCMI”)
A 500 mL reaction vessel equipped with a Dimroth was purged with nitrogen, and then myo-inositol 30 g (167 mmol), DMF 200 mL, p-toluenesulfonic acid monohydrate 863 mg, and dimethoxycyclohexane 75 mL were added and stirred at 100 ° C. for 3 hours. After cooling to 40 ° C., 2.5 mL of triethylamine was added, and DMF as a reaction solvent was distilled off under reduced pressure. Thereafter, 250 mL of ethyl acetate was added, and liquid separation was performed with 300 mL of a 5% aqueous sodium carbonate solution, followed by washing once with 300 mL of ion-exchanged water. The obtained organic phase was distilled off under reduced pressure, crystallization was carried out with 50 mL of ethyl acetate / 70 mL of n-hexane, and the resulting white precipitate was filtered. Thereafter, crystallization was performed again with 50 mL of ethyl acetate / 70 mL of n-hexane. The obtained solid was vacuum-dried at 60 ° C. for 5 hours to obtain 9.8 g (yield: 17.2%) of DCMI as the target compound.

[Synthesis Example 2]
Bis [9- (2-phenoxycarbonylethyl) fluoren-9-yl] methane (hereinafter abbreviated as “BPFM”)
BPFM was synthesized by the method described in WO2014-061677.

[Synthesis example and characteristic evaluation of polycarbonate resin]
Abbreviations and the like of compounds used in the following examples and comparative examples are as follows.
DCMI: DL-2, 3: 5, 6-di-O-cyclohexylidene-myo-inositol ISB: Isosorbide (Rocket Fleure, trade name: POLYSORB)
CHDM: 1,4-cyclohexanedimethanol (cis, trans mixture, manufactured by SK Chemical Company)
BPA: 2,2-bis [4-hydroxyphenyl] propane (manufactured by Mitsubishi Chemical Corporation)
BHEPF: 9,9-bis [4- (2-hydroxyethoxy) phenyl] -fluorene (manufactured by Osaka Gas Chemical Co., Ltd.)
BisZ: 1,1-bis (4-hydroxyphenyl) cyclohexane (manufactured by Honshu Chemical Industry Co., Ltd.)
BPFM: bis [9- (2-phenoxycarbonylethyl) fluoren-9-yl] methane DPC: diphenyl carbonate (manufactured by Mitsubishi Chemical Corporation)

  The structural formula of each raw material compound is shown below.

[Example 1]
DCMI 18.58 parts by weight (0.055 mol), ISB 42.45 parts by weight (0.2908 mol), CHDM 25.42 parts by weight (0.176 mol), DPC 112.79 parts by weight (0.527 mol), and catalyst As a result, 4.59 × 10 ⁻⁴ parts by weight (2.61 × 10 ⁻⁶ mol) of calcium acetate monohydrate was charged into the reactor, and the inside of the reactor was purged with nitrogen under reduced pressure. In a nitrogen atmosphere, the raw materials were dissolved while stirring at 150 ° C. for about 10 minutes. As the first step of the reaction, the temperature was raised to 220 ° C. over 30 minutes, and the reaction was performed at normal pressure for 60 minutes. Next, the pressure was reduced from normal pressure to 13.3 kPa over 90 minutes, maintained at 13.3 kPa for 30 minutes, and the generated phenol was extracted out of the reaction system. Next, as the second step of the reaction, the temperature of the heating medium was raised to 240 ° C. over 15 minutes, the pressure was reduced to 0.10 kPa or less over 15 minutes, and the generated phenol was extracted out of the reaction system. After reaching a predetermined stirring torque, the reaction was stopped by returning the pressure to normal pressure with nitrogen, the produced polycarbonate resin was extruded into water, and the strand was cut to obtain pellets. Using the obtained polycarbonate resin pellets, the various evaluations described above were performed. The evaluation results are shown in Table 1.

  The wavelength dispersion of this polycarbonate resin showed a flat characteristic. Compared with Comparative Example 1, the heat resistance (glass transition temperature) could be improved at the same time while having a low refractive index, a low photoelastic coefficient, and a high total light transmittance.

<Reference Example 1>
When the polymerization reaction was carried out in the same manner as in Example 1 except that the final polymerization temperature was changed to 270 ° C., the resin was wound around the stirring shaft at the end of the reaction, and the molten resin could not be extracted. It was found that when methylene chloride was added to a small amount of collected resin, insoluble components were formed and the polymer was gelled. It is conceivable that the structures (1) to (3) of the present invention are decomposed when reacted at an excessively high temperature to produce a crosslinking component.

<Comparative Example 1>
ISB 42.45 parts by weight (0.290 mol), BPA 17.96 parts by weight (0.079 mol), CHDM 25.42 parts by weight (0.176 mol), DPC 119.17 parts by weight (0.556 mol), and catalyst As in Example 1 except that 9.61 × 10 ⁻⁴ parts by weight (5.45 × 10 ⁻⁶ mol) of calcium acetate monohydrate was used, a polycarbonate resin pellet was obtained. Using the obtained polycarbonate resin pellets, the various evaluations described above were performed. The evaluation results are shown in Table 1.

<Example 2>
DCMI 10.06 parts by weight (0.030 mol), ISB 60.17 parts by weight (0.412 mol), BPFM 27.49 parts by weight (0.043 mol), DPC 85.34 parts by weight (0.398 mol), and catalyst And using 1.55 × 10 ⁻³ parts by weight of calcium acetate monohydrate (8.83 × 10 ⁻⁶ mol), and carrying out the polymerization reaction in the same manner as in Example 1 except that the final polymerization temperature was 250 ° C. Polycarbonate resin pellets were obtained. Using the obtained polycarbonate resin pellets, the various evaluations described above were performed. The evaluation results are shown in Table 2.

  The wavelength dispersion of this polycarbonate resin showed reverse wavelength dispersion. Compared with Comparative Examples 2 and 3, the heat resistance (glass transition temperature) could be improved at the same time while having a low refractive index, a low photoelastic coefficient, and a high total light transmittance.

<Comparative example 2>
ISB 64.27 parts by weight (0.440 mol), BPFM 36.51 parts by weight (0.057 mol), DPC 81.52 parts by weight (0.381 mol), and calcium acetate monohydrate as catalyst 7.75 × 10 ^A polymerization reaction was carried out in the same manner as in Example 2 except that ^-4 parts by weight (4.40 × 10 ⁻⁶ mol) was used, and polyester carbonate resin pellets were obtained. Various evaluations described above were performed using the obtained polyester carbonate resin pellets. The evaluation results are shown in Table 2.

<Comparative Example 3>
ISB 45.42 parts by weight (0.311 mol), BPFM 36.65 parts by weight (0.057 mol), BisZ 20.15 parts by weight (0.075 mol), DPC 70.41 parts by weight (0.329 mol), and catalyst The polymerization reaction was carried out in the same manner as in Example 2 except that 6.80 × 10 ⁻⁴ parts by weight (3.86 × 10 ⁻⁶ mol) of calcium acetate monohydrate was used to obtain polyester carbonate resin pellets. . Various evaluations described above were performed using the obtained polyester carbonate resin pellets. The evaluation results are shown in Table 2.

<Example 3>
DCMI 9.29 parts by weight (0.027 mol), ISB 22.92 parts by weight (0.157 mol), BHEPF 59.47 parts by weight (0.136 mol), DPC 68.50 parts by weight (0.320 mol), and catalyst The polymerization reaction was carried out in the same manner as in Example 2 except that 1.69 × 10 ⁻³ parts by weight (9.59 × 10 ⁻⁶ mol) of calcium acetate monohydrate was used to obtain polycarbonate resin pellets. Using the obtained polycarbonate resin pellets, the various evaluations described above were performed. The evaluation results are shown in Table 2.

  The wavelength dispersion of this polycarbonate resin showed reverse wavelength dispersion. Compared with Comparative Examples 4 and 5, the heat resistance (glass transition temperature) could be improved at the same time while having a low refractive index, a low photoelastic coefficient, and a high total light transmittance.

<Comparative Example 4>
ISB 31.41 parts by weight (0.215 mol), BHEPF 59.47 parts by weight (0.136 mol), DPC 75.85 (0.354 mol), and calcium acetate monohydrate 1.24 × 10 ⁻³ as a catalyst. A polymerization reaction was carried out in the same manner as in Example 2 except that parts by weight (7.01 × 10 ⁻⁶ mol) were used to obtain polycarbonate resin pellets. Using the obtained polycarbonate resin pellets, the various evaluations described above were performed. The evaluation results are shown in Table 2.

<Comparative Example 5>
BHEPF 80.49 parts by mass (0.184 mol), BPA 13.23 parts by mass (0.058 mol), DPC 53.29 parts by mass (0.249 mol), and calcium acetate monohydrate 2.13 × 10 6 as a catalyst ^A polymerization reaction was performed in the same manner as in Example 2 except that ⁻³ parts by mass (1.21 × 10 ⁻⁵ mol) was used, and the final polymerization temperature was 260 ° C., to obtain polycarbonate resin pellets. Using the obtained polycarbonate resin pellets, the various evaluations described above were performed. The evaluation results are shown in Table 2.

Claims (16)

A polycarbonate resin comprising at least a structural unit represented by any one of the following formulas (1) to (3), wherein a stretched film prepared from the resin has a retardation (R450) at a wavelength of 450 nm and a position at a wavelength of 550 nm. A polycarbonate resin having a wavelength dispersion (R450 / R550) value of 0.50 or more and 1.03 or less, which is a ratio to the phase difference (R550).

(In the above formulas (1) to (3), R ^{1 to} R ⁴ each independently represents an organic group having 1 to 30 carbon atoms. These organic groups may have any substituent. Any two or more of R ^{1 to} R ⁴ may be bonded to each other to form a ring.) The polycarbonate resin according to claim 1, wherein R ¹ and R ² , R ³ and R ^{4 in the} formulas (1) to (3) each form a ring with an acetal bond.   The polycarbonate resin according to claim 1 or 2, wherein the cyclohexane ring in the formulas (1) to (3) is an inositol residue derived from myo-inositol. The polycarbonate resin according to any one of claims 1 to 3, comprising at least a structural unit represented by the following formula (4).

  The polycarbonate resin according to any one of claims 1 to 4, which has a glass transition temperature of 100 ° C or higher and 180 ° C or lower.   When the total amount of all structural units constituting the resin and the weight of the linking group is 100% by weight, the structural unit represented by any one of the formulas (1) to (3) is 1% by weight or more, The polycarbonate resin according to any one of claims 1 to 5, which is contained in an amount of 70% by weight or less. Claims containing 1% by weight or more and 70% by weight or less of structural units represented by the following formula (5) when the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight. Item 7. The polycarbonate resin according to any one of Items 1 to 6.

When the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight, at least one structural unit selected from the following formulas (6) to (8) is 1% by weight or more, 70 The polycarbonate resin according to any one of claims 1 to 7, which is contained in an amount of not more than% by weight.

(In the above formula (6), R ^{5 to} R ⁸ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 20 carbon atoms, Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, wherein X is a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6 to 20 carbon atoms, or Represents 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).

(In formula (7) and (8), R < ⁹ > -R < ¹¹ > is a C1-C4 alkylene group which may have a direct bond and a substituent each independently, R < ¹² > -R < ¹⁷ >. Each independently has a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 4 to 10 carbon atoms, and a substituent. An optionally substituted acyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms which may have a substituent, an aryloxy group having 1 to 10 carbon atoms which may have a substituent, An optionally substituted acyloxy group having 1 to 10 carbon atoms, an amino group optionally having substituents, a vinyl group having 1 to 10 carbon atoms optionally having substituents, and a substituent An ethynyl group having 1 to 10 carbon atoms, a sulfur atom having a substituent, and a substituent. A silicon atom, a halogen atom, a nitro group, or a cyano group. However, may form a ring adjacent the at least two groups are bonded to each other among the R ¹² to R ^17.)   When the total amount of all structural units constituting the resin and the weight of the linking group is 100% by weight, from an aliphatic dihydroxy compound, an alicyclic dihydroxy compound, a dihydroxy compound containing an acetal ring, and an oxyalkylene glycol The polycarbonate resin according to any one of claims 1 to 8, comprising a structural unit derived from at least one selected compound from 0.1% by weight to 50% by weight.   When the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight, the aromatic structural unit other than the structural units represented by the formulas (6) to (8) is 5% by weight. % Or less of the polycarbonate resin according to any one of claims 1 to 9. 11. The polycarbonate resin according to claim 1, having a melt viscosity at a measurement temperature of 240 ° C. and a shear rate of 91.2 sec ⁻¹ of 1000 Pa · s to 7000 Pa · s.   The residual amount of carbonic acid diester in the resin is 1 ppm by weight to 300 ppm by weight, and the content of the monohydroxy compound derived from the carbonic acid diester is 1 ppm by weight to 1000 ppm by weight. The polycarbonate resin according to any one of the above.   A method for producing the polycarbonate resin according to any one of claims 1 to 12 by a melt polymerization reaction, wherein a maximum temperature of the melt polymerization reaction is 200 ° C or higher and 260 ° C or lower. Manufacturing method of resin.   A transparent film formed by molding the polycarbonate resin according to any one of claims 1 to 12.   A method for producing the transparent film according to claim 14, wherein the polycarbonate resin according to any one of claims 1 to 12 is molded by a melt film-forming method at a molding temperature of 280 ° C or lower. .   The retardation film which is a unidirectional or bi-directional stretched film of the transparent film according to claim 14.