JP2017075256A - Thermoplastic resin, and optical molding comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin having excellent properties such as heat resistance, optical properties, mechanical properties, and melting workability, and an optical molding comprising the same.SOLUTION: A polycondensed thermoplastic resin comprises at least a specific structural unit and satisfies both of the following conditions (A) and (B): (A) in a stretched film comprising the resin, a birefringence at a wavelength of 550 nm is -0.0015 or less; and (B) a glass-transition temperature of the resin is 120°C or more and 180°C or less.SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic resin that exhibits negative birefringence and is excellent in transparency, heat resistance, and melt processability, and an optical molded body comprising the same.

  In recent years, with the advancement of optoelectronics, the demand for transparent polymers for optics has increased. Among them, resin films having various functions are used in several layers in image display devices such as liquid crystal displays and organic EL displays. When such a display is viewed obliquely with respect to the screen, there is a problem that the contrast is lowered or the display color looks different depending on the viewing direction. When viewed obliquely, the optical path length of a birefringent member such as a retardation film disposed in the panel changes, and the member also has birefringence in the thickness direction. This is considered to be a cause of the above problem.

In order to solve such a problem, when the slow axis x direction refractive index n _x, the fast axis y direction refractive index n _y, the refractive index in the thickness z direction is n _z, n _z> positive B plate satisfying the relation of n _x ≧ n _y, or a positive C plate, it is proposed to use in combination with other retardation film. One method for producing a positive B plate or a positive C plate is a method of stretching a resin having negative intrinsic birefringence (see, for example, Patent Document 1 and Patent Document 2).

  Patent Document 3 discloses a polyester having divalent fluorene as a repeating structural unit. This resin has negative intrinsic birefringence, and its application to uses such as a brightness enhancement film has been studied. However, a material design policy that takes into account balance with other required physical properties such as heat resistance and photoelastic coefficient has not been shown.

JP2015-1111236A JP 2014-149508 A US Patent Application Publication No. 2012/0170118

  In recent years, in the field of optical films, not only improvements in optical properties to improve image display quality, but also thinning of components, processes involving heating during panel assembly processes, and usage environments with high temperatures and high humidity, etc. However, there is also a demand for improving the heat resistance of the material so that the optical properties and dimensions of the member do not change. In order to meet such requirements, the intrinsic birefringence is large, the toughness is excellent (it is possible to develop a large birefringence by stretching), the physical properties are suitable for molding, and the heat resistance is high. Physical properties such as high, high transparency, and low photoelastic coefficient are required for the resin used for the member. Similarly, in the use of optical lenses, there is a demand for improved heat resistance as well as a high refractive index and a low Abbe number. However, in general, when the heat resistance (glass transition temperature) of a resin is increased, the resin becomes brittle and tends to become difficult to stretch. These physical properties are also in a trade-off relationship. It is necessary to devise the molecular design and material design of the resin so as to achieve a balance.

The object of the present invention is to solve the above-mentioned various problems, and to provide a thermoplastic resin excellent in various physical properties such as optical properties, heat resistance, mechanical properties and melt processability, and an optical molded body comprising the same. It is in.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a resin composition containing a polymer having a specific divalent oligofluorene as a repeating unit and having specific optical properties has physical properties. The inventors have found that the object of exhibiting excellent optical properties and excellent mechanical properties when formed into a film can be achieved, and the present invention has been achieved.
That is, the gist of the present invention is as follows.
[1] A thermoplastic resin containing a structural unit represented by the following formula (1) or (2) and satisfying the following (A) and (B).
(A) The orientation birefringence of the stretched film made of the resin at a wavelength of 550 nm is −0.0015 or less.
(B) The glass transition temperature of the resin is 120 ° C. or higher and 180 ° C. or lower.

(In Formula (1) and (2), R < ¹ > -R < ³ > is a C1-C4 alkylene group which may have a direct bond and a substituent each independently, R < ⁴ > -R < ⁹ >. 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 silicon having a substituent. Atom, a halogen atom, a nitro group, or a cyano group. However, they may form a ring adjacent the at least two groups are bonded to each other among the R ⁴ to R ^9.)
[2] A thermoplastic resin containing a structural unit represented by the following formula (3).

(In the formula ^(3), R 1 to R ⁹ are the same .Ar ¹ and ^R 1 to R ⁹ in the formula (1) and (2) is a structural unit derived from the dihydric phenol compound.)
[3] A thermoplastic resin containing the structural unit represented by the formula (1) or (2) and the structural unit represented by the following formula (4).

(In the formula (4), R ^{10 to} R ¹¹ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or 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, Ar ² and Ar ³ each independently represents a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and X is substituted or unsubstituted. It represents a substituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, wherein m and n are each independent. (It is an integer of 0 to 5.)
[4] 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 formula (1) or (2) is contained by 50% by weight or more. The thermoplastic resin according to any one of [1] to [3].
[5] The thermoplastic resin according to any one of [1] to [4], wherein the thermoplastic resin is polyester.
[6] The thermoplastic resin according to any one of [1] to [5], which contains a structural unit represented by the following formula (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 formula (2) is contained by 50% by weight or more, and Polyester containing structural units derived from cyclic dihydroxy compounds.
[8] The polyester according to [7], wherein the structural unit derived from the alicyclic dihydroxy compound is a structural unit represented by the following formula (5).

[9] A transparent film formed by molding the thermoplastic resin according to any one of [1] to [4]. [10] A transparent film formed by molding the polyester according to any one of [5] to [9].
[11] An injection molded product obtained by injection molding the thermoplastic resin according to any one of [1] to [4].
[12] An injection molded product obtained by injection molding the polyester according to any one of [5] to [9].
[13] A method for producing a polyester, comprising subjecting a compound represented by the following formula (6) and a dihydroxy compound to melt polycondensation in the presence of a polymerization catalyst.

(In the formula ^(6), R 1 to R ⁹ is the formula (1) and (2) of ^R 1 to R ⁹ equal .Ar ⁴ and Ar ⁵ aromatic may have a substituent, respectively carbide It is a hydrogen group, and Ar ⁴ and Ar ⁵ may be the same or different.)
[14] The method for producing a polyester according to [13], wherein the dihydroxy compound is a dihydroxy compound represented by the following formula (7) or a divalent phenol compound.

  When the thermoplastic resin of the present invention is formed into a film, it exhibits excellent optical properties, and even if the proportion in the resin is low, the use of a repeating unit that efficiently expresses desired optical properties allows freedom of resin design. It is useful as a material for optical applications, particularly for retardation films, because it has various physical properties such as heat resistance, melt processability, and mechanical strength. Moreover, the suitable manufacturing method of (thermoplastic) resin which has the said effect can be provided.

DESCRIPTION OF EMBODIMENTS Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is as follows unless it exceeds the gist. 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. The linking group means a carbonate bond portion (carbonate group) and an ester bond portion (ester group).

Further, in the present invention, the polyester carbonate resin refers to a resin containing both a portion in which structural units constituting the resin are linked by a carbonate bond and a portion linked by an ester bond.
A first aspect of the present invention is a thermoplastic resin that contains a structural unit represented by the following formula (1) or (2) and satisfies the following (A) and (B).
(A) The birefringence of the stretched film made of the resin at a wavelength of 550 nm is −0.0015 or less.
(C) The glass transition temperature of the resin is 120 ° C. or higher and 180 ° C. or lower.

(In Formula (1) and (2), R < ¹ > -R < ³ > is a C1-C4 alkylene group which may have a direct bond and a substituent each independently, R < ⁴ > -R < ⁹ >. 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 silicon having a substituent. Atom, a halogen atom, a nitro group, or a cyano group. However, they may form a ring adjacent the at least two groups are bonded to each other among the R ⁴ to R ^9.)
The birefringence at a wavelength of 550 nm of the stretched film in the item (A) is −0.0015 or less, that the in-plane slow axis direction of the stretched film made of the resin is a direction perpendicular to the stretched direction. Is negative birefringence, it means that when the birefringence in the orthogonal direction is larger, the value becomes smaller.

The birefringence is more preferably −0.0020 or less, and particularly preferably −0.0025 or less. When this birefringence is larger than the above range, it is considered that the film thickness required to develop a desired phase difference becomes large and it is difficult to incorporate the film into a display panel. The stretched film production method and birefringence measurement method will be described later.
In the first aspect of the present invention, the upper limit of the glass transition temperature of the item (B) is more preferably 175 ° C. or less, and particularly preferably 170 ° C. or less. When the glass transition temperature is higher than the above upper limit, it is necessary to carry out melt processing at a high temperature, so that the molecular weight of the resin is greatly reduced due to thermal decomposition, decomposition gas is generated, and the appearance of the molded product is impaired. There is a risk of Moreover, since the obtained resin becomes brittle and the film is easily broken at the time of stretching, there is a possibility that the high orientation which is the object of the present invention cannot be obtained. On the other hand, the lower limit of the glass transition temperature is preferably 155 ° C or higher, particularly preferably 160 ° C or higher. When the glass transition temperature is lower than the lower limit, it is difficult to apply to applications that require durability and reliability in a high-temperature and high-humidity environment.
The second aspect of the present invention is a thermoplastic resin containing a structural unit represented by the following formula (3).

(In the formula ^(3), R 1 to R ⁹ are the same .Ar ¹ and ^R 1 to R ⁹ in the formula (1) and (2) is a structural unit derived from the dihydric phenol compound.)
Since the polyester using a dihydric phenol compound can greatly improve the heat resistance as compared with the polyester using an aliphatic dihydroxy compound, it can be suitably used in a field requiring heat resistance.

In the second aspect, as the divalent phenol compound, 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 3-methylphenyl) sulfide, bis (4-hydroxyphenyl) disulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dichlorodiphenyl ether, 6,6′-dihydroxy-3,3 3 ′, 3′-tetramethyl-1,1′-spirobiindane, 7,7′-dimethyl-6,6′-dihydroxy-3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene, 9,9 -Bis (2-hydroxynaphthyl) fluorene and the like.

  Among the dihydric phenol compounds, 6,6′-dihydroxy-3,3,3 ′, 3′-tetramethyl-1, from the viewpoint of balance of various physical properties such as optical properties, heat resistance, and mechanical properties. 1'-spirobiindane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) It is particularly preferable to use fluorene or 9,9-bis (2-hydroxynaphthyl) fluorene.

  The upper limit of the content of the structural unit derived from the divalent phenol compound in the resin is 50% by weight or less when the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight. Is preferable, 40% by weight or less is more preferable, and 30% by weight or less is particularly preferable. Heat resistance can be improved by having a structural unit derived from a dihydric phenol compound, but when the content of the structural unit derived from the dihydric phenol compound in the resin is greater than the upper limit, Heat resistance may become excessively high and workability may be impaired. Moreover, since the ratio of the other copolymerization component in resin becomes small, it becomes difficult to adjust the balance of physical properties, such as an optical characteristic and a mechanical physical property. In addition, since the dihydric phenol compound is inferior in polymerization reactivity as compared with the aliphatic dihydroxy compound, the resin obtained when the content of the structural unit derived from the dihydric phenol compound in the resin is too high can be reduced to a desired molecular weight. It becomes difficult to advance the reaction. On the other hand, the lower limit of the content of the structural unit derived from the divalent phenol compound in the resin is preferably 1% by weight or more, more preferably 3% by weight or more, and particularly preferably 5% by weight or more. When the content of the structural unit derived from the divalent phenol compound in the resin is less than the above range, the effect of improving the heat resistance cannot be sufficiently obtained.

Since the resin of the second aspect of the present invention contains many structural units derived from an aromatic compound, the refractive index can be increased. Therefore, it can be suitably used not only for the retardation film but also for the optical lens.
A third aspect of the present invention is a thermoplastic resin containing the structural unit represented by the formula (1) or (2) and the structural unit represented by the following formula (4).

(In the formula (4), R ^{10 to} R ¹¹ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or 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, Ar ² and Ar ³ each independently represents a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and X is substituted or unsubstituted. It represents a substituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, wherein m and n are each independent. (It is an integer of 0 to 5.)

Similarly to the structural unit represented by the formula (1) or (2), the structural unit represented by the formula (4) is a component that develops negative birefringence in the resin, and the resin has heat resistance and mechanical properties. Can be imparted in a well-balanced manner.
As the dihydroxy compound containing the structural unit represented by the formula (4), for example, the following dihydroxy compounds can be used.

  9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-tert-butylphenyl) fluorene, 9 , 9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dimethylphenyl) Fluorene, 9,9-bis (2-hydroxynaphthyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-hydroxypropoxy) phenyl) fluorene 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- 2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-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 (2- (2-hydroxyethoxy) naphthyl) fluorene, and the like.

  In the third aspect of the present invention, the upper limit of the content of the structural unit represented by the formula (4) in the resin is 100 weights of the total weight of all the structural units constituting the resin and the linking group. % Is preferably 60% by weight or less, more preferably 55% by weight or less, and particularly preferably 50% by weight or less. Since the structural unit represented by the formula (4) has a smaller negative intrinsic birefringence than the structural unit represented by the formula (1) or (2), the structural unit represented by the formula (4) When the content in the resin is larger than the above upper limit, the high orientation of the resin that is the object of the present invention may not be obtained. On the other hand, the lower limit of the content of the structural unit represented by the formula (4) in the resin is 1 when the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight. % By weight or more is preferable, 5% by weight or more is more preferable, and 10% by weight or more is particularly preferable. When the content of the structural unit represented by the formula (4) in the resin is smaller than the lower limit, the advantages of the structural unit represented by the formula (4) such as heat resistance and high refractive index are sufficient. Cannot be applied to resin.

Since the thermoplastic resin of the third aspect of the present invention contains many structural units derived from an aromatic compound, the refractive index of the resin can be increased. Therefore, it can be suitably used not only for the retardation film but also for the optical lens.
In a fourth aspect of the present invention, 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 formula (2) is 50% by weight. It is polyester which contains above and contains at least a structural unit derived from an alicyclic dihydroxy compound.

Compared to linear aliphatic dihydroxy compounds, cycloaliphatic dihydroxy compounds can impart heat resistance and mechanical properties to the resin in a well-balanced manner, and also have excellent optical properties such as a low photoelastic coefficient. And is suitably used for the thermoplastic resin of the present invention.
In the fourth aspect, 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 thereof 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. A dihydroxy compound which is a primary alcohol of an alicyclic hydrocarbon.

Fats exemplified by 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantanediol, hydrogenated bisphenol A, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc. Dihydroxy compounds that are secondary alcohols and tertiary alcohols of cyclic hydrocarbons.
A dihydroxy compound containing a condensed ring structure represented by the following formula (7), exemplified by isosorbide (ISB), isomannide, isoidet and the like.

  Acetal ring exemplified by spiroglycol represented by the following structural formula (8), dioxane glycol represented by the following structural formula (9), dihydroxy compound derived from inositol represented by the following structural formula (10), etc. A dihydroxy compound containing

(In the above formula (10), R ¹² and R ¹³ each independently represents an organic group having 1 to 30 carbon atoms. These organic groups may have an arbitrary substituent.)
In the formula (10), R ¹² and R ¹³ are preferably an organic group having 1 to 30 carbon atoms which may have a substituent. Examples of the organic group having 1 to 30 carbon atoms of R ¹² and R ¹³ 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, 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 Alkynyl groups such as ethynyl group, methylethynyl group, 1-propionyl group, aryl groups such as phenyl group, naphthyl group, toluyl group, alkoxyphenyl groups such as methoxyphenyl group, aralkyl groups such as benzyl group, phenylethyl group, Heterocyclic groups such as thienyl group, pyridyl group, furyl group and the like can be mentioned. Among these, from the viewpoint of the stability of the resin 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 properties and weather resistance of the resin, heat resistance and mechanical properties, the alkyl group A cycloalkyl group is particularly preferred.

Among the alicyclic dihydroxy compounds, isosorbide, tricyclodecane dimethanol, 2,6-decalin dimethanol, 2,2,4,4-tetramethyl having high heat resistance and low photoelastic coefficient It is preferable to use -1,3-cyclobutanediol or spiroglycol, and isosorbide is particularly preferable.
A fifth aspect of the present invention is a method for producing a polyester, in which a compound represented by the following formula (6) and a dihydroxy compound are melt polycondensed in the presence of a polymerization catalyst.

(In the formula ^(6), R 1 to R ⁹ is the formula (1) and (2) of ^R 1 to R ⁹ equal .Ar ⁴ and Ar ⁵ aromatic may have a substituent, respectively carbide It is a hydrogen group, and Ar ⁴ and Ar ⁵ may be the same or different.)
Since the compound represented by the formula (6) is more excellent in polymerization reactivity than the corresponding dialkyl ester or dicarboxylic acid, it is usually possible to use a dihydroxy compound that does not easily react with the dialkyl ester in the polymerization reaction. Moreover, it has the outstanding feature that the addition amount of the polymerization catalyst used for the polymerization reaction can be reduced.

  In the fifth aspect, it is particularly effective to use a dihydroxy compound represented by the following formula (7) or a dihydric phenol compound as the dihydroxy compound. Although the two dihydroxy compounds are difficult to polymerize with a dialkyl ester, a polyester can be obtained by reacting with the compound represented by the formula (6).

  In addition, since the polymerization catalyst remaining in the resin often becomes a foreign matter in the molded product, particularly in a resin used for optical applications, the foreign matter in the molded product can be reduced by reducing the amount of the polymerization catalyst added during the polymerization reaction. Can be reduced.

[Structure and raw material of thermoplastic resin]
(Thermoplastic resin)
The thermoplastic resin of the present invention is a polycondensation resin, and examples of the polycondensation resin include polycarbonate, polyester, polyester carbonate, polyamide, and polyimide. The thermoplastic resin of the present invention is preferably at least one resin selected from the group consisting of polycarbonate, polyester, and polyester carbonate, and particularly preferably polyester. The above resin can incorporate the oligofluorene structural unit of the present invention, and is easily rendered amorphous by copolymerizing various monomers. Moreover, according to the required physical property, it is mentioned as an advantage that each physical property such as optical properties, mechanical properties, and heat resistance can be easily adjusted to a preferable range.

(Oligofluorene structural unit)
The thermoplastic resin of the present invention contains a structural unit selected from structural units represented by the following formula (1) or (2). The structural units represented by the following formulas (1) and (2) may be referred to as “oligofluorene structural units”.

(In Formula (1) and (2), R < ¹ > -R < ³ > is a C1-C4 alkylene group which may have a direct bond and a substituent each independently, R < ⁴ > -R < ⁹ >. 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 silicon having a substituent. Atom, a halogen atom, a nitro group, or a cyano group. However, they may form a ring adjacent the at least two groups are bonded to each other among the R ⁴ to R ^9.)

  Many polymers have positive intrinsic birefringence, while oligofluorene structural units have negative intrinsic birefringence. The oligofluorene structural unit also has a characteristic that the photoelastic coefficient is relatively small, and a resin having a low photoelastic coefficient can be obtained. Furthermore, since this oligofluorene structural unit has an aromatic structure at a high density, it can be suitably used even when a high refractive index is required in applications such as optical lenses.

The structural units represented by the formulas (1) and (2) differ in the magnitude of negative intrinsic birefringence depending on the structures of R ^{1 to} R ⁹ , but the content in these resins constitutes the resin. When the total amount of all structural units and linking groups is 100% by weight, it is preferably contained in an amount of 50% by weight or more, more preferably 60% by weight or more, and particularly preferably 70% by weight or more.
In R ¹ and R ² in the above formulas (1) and (2), 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 ¹ and R ² is indicated by a number assigned so that the carbon on the fluorene ring side is in the first position.

The selection of R ¹ and R ² has a particularly important influence on the development of optical properties such as negative birefringence and photoelastic coefficient. In the state where the fluorene ring in the oligofluorene structural unit is oriented perpendicular to the main chain direction (stretching direction), the greatest negative birefringence is expressed. In order to bring the orientation state of the fluorene ring close to the above state and to express a large negative birefringence, it is preferable to employ R ¹ and R ² having ² to 3 carbon atoms on the main chain of the alkylene group. . When the number of carbon atoms is 1, there may be unexpectedly no negative birefringence. 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 fixation of the orientation of the fluorene ring is weakened, which may weaken the negative birefringence. In addition, the heat resistance of the resin tends to decrease.

As shown in the formulas (1) and (2), R ¹ and R ² are either an oxygen atom in which one end of an alkylene group is bonded to a fluorene ring and the other end is an oxygen atom or carbonyl carbon contained in the linking group. Are connected. From the viewpoints of thermal stability, heat resistance, and negative birefringence, the other end of the alkylene group is preferably 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 ¹ and R ² .

In R ³ , 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 ³ preferably has 1 to 2 carbon atoms on the main chain of the alkylene group, and particularly preferably 1 carbon atom. When R ³ having too many carbons on the main chain is employed, the fixation of the fluorene ring is weakened similarly to R ¹ and R ² , the negative birefringence 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 ^{4 to} R ⁹ are hydrogen atoms, or R ⁴ and / or R ⁹ are halogen atoms, acyl groups, nitro groups, cyano groups, and sulfo groups. It is preferably any one selected from the group consisting of groups, and any structure in which R ^{5 to} R ⁸ are 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. Further, in the case of having the latter configuration, the reactivity at the 9th position of fluorene 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 ^{4 to} R ⁹ are hydrogen atoms, or R ⁴ and / or R ⁹ are selected from the group consisting of a fluorine atom, a chlorine atom, a bromine atom, and a nitro group. It is more preferable that R ^{5 to} R ⁸ are any of hydrogen atoms, and a structure in which all of R ^{4 to} R ⁹ 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.

Among the divalent oligofluorene structural units represented by the above formulas (1) and (2), preferred structures include structures having a skeleton specifically exemplified in the following group [A].
[A]

  Examples of the monomer having an oligofluorene structural unit include a specific dihydroxy compound represented by the following formula (11) and a specific diester represented by the following formula (6).

(Yes in the formula (11) and ^(12), R 1 to R ⁹ is the formula (1) and (2 same .A ¹ and ^{A 2} and ^R 1 to R ⁹ in) is hydrogen atom, or a substituent An aliphatic hydrocarbon group having 1 to 18 carbon atoms which may be substituted, 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 compound having a divalent oligofluorene structural unit, it is particularly preferable to use a specific diester represented by the formula (12). The specific diester is relatively better in thermal stability than the specific dihydroxy compound represented by the formula (11), and the fluorene ring in the resin is oriented in a preferred direction, resulting in a larger negative compound. There is a tendency to develop refraction. Therefore, it is particularly preferable that the thermoplastic resin of the present invention is polyester so that the content of the diester structural unit represented by the formula (12) can be increased.

When A ¹ and A ^{2 in} the formula (12) are hydrogen atoms or aliphatic hydrocarbon groups such as a methyl group or an ethyl group, the polymerization reaction hardly occurs under the polymerization conditions of polycarbonates and polyesters that are usually used. Sometimes. Therefore, A ¹ and A ^{2 in} the formula (12) are preferably aromatic hydrocarbon groups.
(Dihydroxy compound)
The thermoplastic resin of the present invention preferably contains a structural unit represented by the following formula (5).

The upper limit of the content of the structural unit represented by the formula (5) in the thermoplastic resin is 70 when the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight. % By weight or less is preferable, 65% by weight or less is more preferable, and 60% by weight or less is particularly preferable. When content of the structural unit represented by said Formula (5) is larger than the said upper limit, the heat resistance of resin will become high too much, and a mechanical characteristic and melt processability will deteriorate. Moreover, since the structural unit represented by the formula (5) has a highly hygroscopic structure, the resin has a high water absorption when the content of the structural unit represented by the formula (5) is excessively high. Therefore, there is a possibility that the optical physical properties of the molded product may change or a deformation or a crack may occur in a high humidity environment.

  On the other hand, the lower limit of the content of the structural unit represented by the formula (5) in the thermoplastic resin is when the total weight of all the structural units constituting the resin and the linking group is 100% by weight. It is preferably 10% by weight or more, more preferably 15% by weight or more, and particularly preferably 20% by weight or more. If it is smaller than the lower limit, the heat resistance of the resin may be insufficient, or optical characteristics such as high transmittance and low photoelastic coefficient, which are characteristics of the structural unit represented by the formula (5), may not be obtained. there is a possibility.

  Examples of the dihydroxy compound into which the structural unit represented by the formula (5) can be introduced include isosorbide (ISB), isomannide and isoidet which are in a stereoisomeric relationship. 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 containing the structural unit of the formula (5) may be referred to as “dihydroxy compound A”.

The dihydroxy compound A may contain a stabilizer such as a reducing agent, antioxidant, oxygen scavenger, light stabilizer, antacid, pH stabilizer or heat stabilizer. In particular, since the dihydroxy compound A 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 droxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide and butyltriphenylammonium hydroxide; diethylamine, di 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 A is not particularly limited. However, since the dihydroxy compound A is unstable in an acidic state, the pH of the aqueous solution of the dihydroxy compound A containing the stabilizer is around 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 A may not be obtained. If the amount is too large, the modification of the dihydroxy compound A 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 A is easy to absorb moisture and is gradually oxidized by oxygen, it should not be mixed with moisture during handling during storage or manufacturing. Or the like.
The thermoplastic resin of the present invention may contain structural units other than the structural units described above (hereinafter, may be referred to as “other structural units”), and the compound containing other structural units is Examples thereof include aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, dihydroxy compounds containing acetal rings, oxyalkylene glycols, dihydroxy compounds containing aromatic components, diester compounds, and the like.

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 thereof 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 which are primary alcohols of alicyclic hydrocarbons; 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantanediol, hydrogenated bisphenol A, 2,2,4,4-tetra Methyl-1,3-cyclobutane Illustrated in Lumpur like, dihydroxy compound which is a secondary alcohol and tertiary alcohol alicyclic hydrocarbon.

  Examples of the dihydroxy compound containing an acetal ring include spiro glycol represented by the following structural formula (8), dioxane glycol represented by the following structural formula (9), and inositol represented by the following structural formula (10). Induced dihydroxy compounds and the like can be used.

(In the above formula (10), R ¹² and R ¹³ each independently represents an organic group having 1 to 30 carbon atoms. These organic groups may have an arbitrary substituent.)
In the formula (10), R ¹² and R ¹³ are preferably an organic group having 1 to 30 carbon atoms which may have a substituent. Examples of the organic group having 1 to 30 carbon atoms of R ¹² and R ¹³ 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, 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 Alkynyl groups such as ethynyl group, methylethynyl group, 1-propionyl group, aryl groups such as phenyl group, naphthyl group, toluyl group, alkoxyphenyl groups such as methoxyphenyl group, aralkyl groups such as benzyl group, phenylethyl group, Heterocyclic groups such as thienyl group, pyridyl group, furyl group and the like can be mentioned. 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 properties and weather resistance of the resin, heat resistance and mechanical properties, the alkyl group A cycloalkyl group is particularly preferred.

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 3-methylphenyl) sulfide, bis (4-hydroxyphenyl) disulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dichlorodiphenyl ether, 6,6′-dihydroxy-3,3 3 ′, 3′-tetramethyl-1,1′-spirobiindane, 7,7′-dimethyl-6,6′-dihydroxy-3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene, 9,9 -Aromatic bisphenol compounds such as bis (2-hydroxynaphthyl) fluorene; 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 (2-hydroxyethoxy) biphenyl, bis (4 -(2-hydroxyethoxy) phenyl) sulfone, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene A dihydroxy compound having an ether group bonded to an aromatic group such as 9,9-bis (2- (2-hydroxyethoxy) naphthyl) fluorene.

  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 Aromatic dicarboxylic acids such as' -diphenylsulfone dicarboxylic acid and 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 other than the dihydroxy compound containing an aromatic component as the other structural units listed above. However, while ensuring the optical properties, the balance with heat resistance, mechanical properties, etc. Therefore, it may be effective to incorporate an aromatic component into the main chain or side chain of the resin. In this case, structural units derived from a dihydroxy compound containing an aromatic component can be introduced into the resin, but the content of these structural units in the thermoplastic resin of the present invention is all that constitutes the resin. When the total amount of the structural unit and the linking group is 100% by weight, it is preferably 50% by weight or less, more preferably 40% by weight or less, and particularly preferably 30% by weight or less. When the amount of other structural units containing an aromatic structure increases, the photoelastic coefficient may be deteriorated.

Examples of the compound containing other structural units listed above include 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, spiroglycol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, It is particularly preferable to use 1,4-cyclohexanedicarboxylic acid and decalin-2,6-dicarboxylic acid (and derivatives thereof). For the purpose of improving the heat resistance while satisfying the optical properties of the resulting resin, 6,6′-
It is particularly preferable to use a dihydroxy compound derived from dihydroxy-3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane or inositol represented by the formula (10). Resins containing structural units derived from these compounds 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 upper limit of the content of other structural units in the resin is preferably 50% by weight or less, when the total amount of all the structural units constituting the resin and the weight of the linking group is 100% by weight, and 45% by weight. The following is more preferable, and 40% by weight or less is particularly preferable.

  On the other hand, the lower limit of the content of other structural units in the thermoplastic resin is preferably 0.1% by weight or more, more preferably 1% by weight or more, and particularly preferably 3% by weight or more. 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)
A carbonate bond, which is a linking group contained in polycarbonate or polyester carbonate, which is a preferred form of the thermoplastic resin of the present invention, is introduced by polymerizing a carbonic acid diester represented by the following formula (13).

(In Formula (13), A ³ and A ⁴ are each an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms or an optionally substituted aromatic hydrocarbon group. 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, a carboxylic acid, an amide group, and a halogen. Examples of the substituent of the aromatic hydrocarbon group include an alkyl group such as a methyl group and an ethyl group. Is mentioned.

  Examples of the carbonic acid diester represented by the formula (13) 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, which may hinder the polymerization reaction or deteriorate the hue of the resulting resin. It is preferable to use it.
Further, when the above formula (12) using both the diester monomer carbonic acid diester represented by formula (13) represented by the polymerization reaction, A ^1, A ² and the of the formula (12) When A ³ and A ^{4 in} formula (13) all have the same structure, the components that are eliminated during the polymerization reaction are the same, and the components are 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 thermoplastic resin]
Polycarbonate, polyester, and polyester carbonate, which are preferred forms of the thermoplastic resin of the present invention, can be produced by a commonly 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.

  If a solvent is used for the polymerization, the solvent may remain in the resin, and the glass transition temperature of the resin decreases due to its plasticizing effect, which may cause quality fluctuations in processing steps such as molding and stretching described later. 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 the resin is produced by the melt polymerization method, the monomer having the above-mentioned structural unit, a carbonic acid diester, and a polymerization catalyst are mixed, and an ester exchange reaction (also referred to as a polycondensation reaction) is performed under melting, followed by desorption. The reaction rate is increased while removing the separated 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 to obtain the thermoplastic resin of the present invention.

  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, the molar ratio of the 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 03. In the case of polyester or polyester carbonate, the molar ratio of the total amount of carbonic diester and all diester compounds to all dihydroxy compounds is preferably adjusted to 0.90 to 1.10, and adjusted to 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 stains 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 of the present invention, the wavelength dispersion of the retardation is controlled by the ratio of the fluorene-based monomer in the resin and other copolymerization components, so if the ratio collapses during polymerization, the optical characteristics as designed May not be obtained.

Hereinafter, the process of the melt polycondensation reaction will be described by dividing it into a stage in which monomers are consumed to produce oligomers and a stage in which polymerization is advanced to a desired molecular weight to produce polymers.
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 is usually 70 kPa or less (hereinafter, pressure represents an absolute pressure), 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 270 ° C. or lower, preferably 260 ° 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 coloring and thermal deterioration and obtain a resin having good hue and thermal stability, the maximum internal temperature in all reaction stages is 270 ° C. or lower, preferably 265 ° C. or lower, more preferably 260 ° C. or lower. Good.

  A transesterification catalyst that can be used at the time of polymerization (hereinafter sometimes simply referred to as a catalyst or a polymerization catalyst) can have a great influence on the reaction rate and the color tone and thermal stability of a resin obtained by polycondensation. . The catalyst used is not limited as long as it can satisfy the transparency, hue, heat resistance, thermal stability, and mechanical strength of the produced resin, but it is not limited to Group 1 or Group 2 in the long-period periodic table. (Hereinafter, simply referred to as “Group 1” and “Group 2”) include basic compounds such as metal compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds. Preferably, at least one metal compound selected from the group consisting of a long-period periodic table group 2 metal 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 metals 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 the polymerization catalyst, when using at least one metal compound selected from the group consisting of a metal 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.

In addition, when a polyester or polyester carbonate is produced using a diester compound as a monomer, a titanium compound, a tin compound, a germanium compound, an antimony compound, a zirconium compound, in combination with or without using the basic compound, Transesterification catalysts such as lead compounds, osmium compounds, zinc compounds and manganese compounds 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 relative to 1 mol of all dihydroxy compounds used in the reaction. It is 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 a large amount 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.

  The thermoplastic resin of the present invention can be polymerized as described above, and then usually cooled and solidified, and pelletized with a rotary cutter or the like. The method of pelletization is not limited, but it is extracted from the final stage polymerization reactor in a molten state, cooled and solidified in the form of a strand and pelletized, uniaxially or in a molten state from the final stage polymerization reactor. The resin is supplied to a twin-screw extruder, melt-extruded, cooled and solidified into pellets, or extracted from the polymerization reactor in the final stage in a molten state, cooled and solidified in the form of strands, and pelletized once. Examples thereof include a method in which the resin is supplied again to the single-screw or twin-screw extruder, melt-extruded, and then cooled, solidified, and pelletized.

  Since the thermoplastic resin of the present invention is suitably used for optical applications, it is preferable that the resin contains little foreign matter. In order to remove foreign matters such as burns and gels in the resin obtained by melt polycondensation, it is preferable to perform filtration using a filter. Among them, the residual monomer and by-product phenol etc. are removed by devolatilization under reduced pressure, and after the resin is melt-extruded with the vent type twin screw extruder in order to mix additives such as a heat stabilizer and a release agent, It is preferable to filter with a filter.

  As a form of this filter, a known type such as a candle type, a pleat type, a leaf disk type, or the like can be used. The opening of the filter is preferably 50 μm or less, more preferably 40 μm or less, and still more preferably 20 μm or less as 99% filtration accuracy. The filter aperture is preferably 10 μm or less to reduce the amount of foreign matter. However, if the aperture is small, the pressure loss in the filter increases and the filter is damaged or the resin is deteriorated by shearing heat generation. Therefore, the filtration accuracy of 99% is preferably 1 μm or more. The aperture of the filter referred to here is determined in accordance with ISO16889.

The resin filtered by the filter is discharged from the die head in the form of a strand, cooled and solidified, and pelletized by a rotary cutter or the like. In order to prevent foreign matter from entering from outside air, preferably JISB
It is desirable to implement in a clean room having a higher degree of cleanliness than Class 7 defined in 9920 (2002), more preferably Class 6.

  When pelletizing, it is preferable to use a cooling method such as air cooling or water cooling. The air used for air cooling is air obtained by removing foreign substances in the air in advance with a hepa filter or the like. It is desirable to prevent reattachment of foreign matter inside. When using water cooling, it is desirable to use water from which metal in water has been removed with an ion exchange resin or the like, and further, foreign matter in water has been removed with a water filter. The aperture of the water filter to be used is preferably 10 to 0.45 μm as the filtration accuracy for 99% removal.

[Additive]
In the thermoplastic resin of the present invention, a heat stabilizer, an antioxidant, a catalyst deactivator, an ultraviolet absorber, a light stabilizer, a mold release agent, a dye, an impact, which are usually used, as long as the object of the present invention is not impaired. An improving 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 thermoplastic resin of the present invention can be blended with a thermal stabilizer in order to prevent a decrease in molecular weight and a deterioration in hue during melt processing. Examples of such heat stabilizers include generally 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 thermoplastic resin of the present invention to neutralize and deactivate the catalyst used in the polymerization reaction, it is possible to improve color tone and thermal stability. As an acidic compound used as a 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 (14) or (15) It is preferable to use a phosphorus compound containing a partial structure represented by

Examples of the phosphorus compound represented by the formula (14) or (15) 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 too large, the resin may be colored instead. In particular, in the durability test under high temperature and high humidity, 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 thermoplastic 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. Further, a polymer alloy formed by kneading with one or more of synthetic resins such as polylactic acid and polybutylene succinate, rubber, elastomer and the like may be used.
The above additives and modifiers are mixed in the thermoplastic resin used in the present invention simultaneously or in any order with a tumbler, V-type blender, nauter mixer, Banbury mixer, kneading roll, extruder, etc. It can be produced by mixing with an extruder, but among them, kneading with an extruder, particularly a twin screw extruder is preferable from the viewpoint of improving dispersibility.

[Physical properties of thermoplastic resin]
The molecular weight of the thermoplastic resin of the present invention thus obtained can be represented by a reduced viscosity. If the reduced viscosity of the resin is too low, the mechanical strength of the 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.
ADVANTAGE OF THE INVENTION According to this invention, the polycarbonate resin of the viscosity range which enables easy melt processing can be obtained in the temperature range which can suppress the thermal deterioration of polycarbonate resin, having sufficient mechanical properties. The preferable range of the viscosity which is the effect of the present invention is specifically that the melt viscosity is 2000 Pa · s or more and 6000 Pa · s or less under the measurement conditions of a temperature of 240 ° C. and a shear rate of 91.2 sec ⁻¹ . More preferably, it is 2300 Pa · s or more, and 2500 Pa · s or more is particularly preferable. On the other hand, the upper limit is more preferably 5300 Pa · s or less, and particularly preferably 5000 Pa · s or less. The melt viscosity is measured using a capillary rheometer (manufactured by Toyo Seiki Seisakusho).

  The glass transition temperature of the thermoplastic resin of the present invention is preferably 120 ° C. or higher and 180 ° C. or lower. When the thermoplastic resin of the present invention is used for applications requiring durability and reliability at high temperature and high humidity, the lower limit of the glass transition temperature is preferably 150 ° C or higher, more preferably 155 ° C or higher, and 160 ° C. The above is particularly preferable. On the other hand, the upper limit of the glass transition temperature is preferably 180 ° C. or lower, more preferably 175 ° C. or lower, and particularly preferably 170 ° C. or lower. The glass transition temperature 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 article 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.

  When diester compounds are used in the polycondensation reaction, by-product monohydroxy compounds remain in the resin, so they volatilize during melt processing and become odors, worsening the working environment, and contaminating the molding machine. The appearance of the product may be damaged. 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.

  Therefore, the monohydroxy compound contained in the resin is preferably 1000 ppm by weight or less. Further, it is preferably 600 ppm by weight or less, and particularly preferably 450 ppm by weight or less. In order to solve the above problems, the monohydroxy compound should have a lower content. However, it is difficult to eliminate the monohydroxy compound remaining in the resin by the melt polymerization method. Requires excessive effort. Usually, the above-mentioned problem can be sufficiently suppressed by reducing the content of the monohydroxy compound to 1 ppm by weight.

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

In addition to the above monohydroxy compound, unreacted monomer components in the resin may become residual low molecular components. In particular, carbonic acid diester tends to remain. As with the remaining monohydroxy compounds, these components can be reduced to a specific amount or less by controlling the end group balance and reaction pressure at the end of the polymerization, or by devolatilizing the resin with an extruder. Become. In the resin of the present invention, the residual amount of carbonic acid diester 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 content of the carbonic acid diester is preferably as low as possible. However, in the melt polymerization method, it is difficult to make the carbonic acid diester remaining in the resin zero. Requires a lot of effort. Usually, the above problem can be sufficiently suppressed by reducing the content of carbonic acid diester to 1 ppm by weight.

If the photoelastic coefficient of the thermoplastic resin is excessively large, there is a possibility that when the retardation film is bonded to the polarizing plate, the image quality is deteriorated such that the periphery of the screen is blurred in white. This problem is particularly noticeable when used in large display devices and flexible displays. The thermoplastic resin of the present invention is composed of the structural unit represented by the formula (1) or (2), has a glass transition temperature of 120 ° C. or higher and 180 ° C. or lower, and has a wavelength of 550 nm when used as a stretched film. When the orientation birefringence is −0.0015 or less, the photoelastic coefficient can be kept low.
Specifically, for example, the photoelastic coefficient of the thermoplastic resin of the present invention can take a value of 30 × 10 ⁻¹² Pa ⁻¹ or less, and more preferably 20 × 10 ⁻¹² Pa ⁻¹ or less. It is possible to take a value, and more preferably, it is possible to take a value of 10 × 10 ⁻¹² Pa ⁻¹ or less.

  When the thermoplastic resin of the present invention is used for applications requiring a high refractive index and a low Abbe number such as an optical lens, it is possible to obtain a resin having a refractive index of 1.55 or more at the sodium D line of the resin, More preferably 1.60 or more, still more preferably 1.62 or more. . In general, when the refractive index of the optical material is high, it is possible to reduce the number of lenses, reduce the eccentric sensitivity of the lens, and reduce the size and weight of the lens system by reducing the lens thickness.

[Use of thermoplastic resin]
The thermoplastic resin of the present invention and the resin composition containing the thermoplastic resin can be formed into a molded article by a generally known method such as an injection molding method, an extrusion molding method, a compression molding method, optical properties, heat resistance, A molded product having excellent mechanical strength can be obtained.

(Film or sheet forming method)
As a method for forming a film or a sheet using the thermoplastic 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. It is possible to employ a melt film-forming method for forming a film. 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 coextrusion method, a comelting 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. Here, the molding temperature of the unstretched film is a temperature at the time of molding in the melt film-forming method, and is usually a value obtained by measuring the resin temperature at the die outlet for extruding the molten resin.

The presence of foreign matter in the film is recognized as a defect such as light leakage when used inside an image display device. 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.

  Regardless of the thickness of the film or sheet, the total light transmittance of the film itself is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. When the transmittance is equal to or higher than the lower limit, high display quality can be realized when used in an image display apparatus. The upper limit of the total light transmittance of the film of the present invention is not particularly limited, but is usually 99% or less.

  By stretching the film made of the thermoplastic resin of the present invention, the area of the film can be expanded without developing birefringence. 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.

  The stretching temperature is in the range of (Tg-20 ° C) to (Tg + 30 ° C), preferably in the range of (Tg-10 ° C) to (Tg + 20 ° C) with respect to the glass transition temperature (Tg) of the resin used as the raw material. Is within. The draw ratio is 1.2 to 4 times, more preferably 1.5 to 3.5 times, and still more preferably 2 to 3 times in the longitudinal and lateral directions. 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% / min, preferably 100 to 1500% / min, more preferably 200 to 1000% / min, especially at the strain rate represented by the following formula. Preferably, it can be selected to be 250 to 500% / min. 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) / length of original film (mm)} × 100

  After stretching the film, if necessary, a heat setting treatment may be performed by a heating furnace, or a relaxation treatment may be performed by controlling the width of the tenter or adjusting the roll peripheral speed. The temperature of the heat setting treatment is 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. In the case of providing a relaxation step, the stress generated in the stretched film can be removed by shrinking to 95% to 99% with respect to the width of the film spread by 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.

(Molding method of injection molded product)
The molding method of the injection molded body is not particularly limited, and for example, an injection molding method such as a general injection molding method for a thermoplastic resin, a gas assist molding method, and an injection compression molding method can be employed. In addition to the above methods, an in-mold molding method, a gas press molding method, a two-color molding method, a sandwich molding method, or the like can be employed in accordance with other purposes.

  As with the aforementioned extrusion molding, in order to improve the appearance of the molded product, the cylinder temperature is preferably 280 ° C. or lower, more preferably 270 ° C. or lower, and particularly preferably 265 ° C. or lower. . On the other hand, when particularly low birefringence is required, such as an optical lens, it is preferable to mold it so as not to leave distortion at a higher temperature, and it is possible to consider a situation where the cylinder temperature is preferably 280 to 320 ° C. In that case, it is necessary to reduce the residence time of the molten resin to suppress thermal degradation. The lower limit of the cylinder temperature is usually 200 ° C. or higher, preferably 210 ° C. or higher, more preferably 220 ° C. or higher.

  The thermoplastic resin of the present invention is a resin that expresses negative birefringence and is excellent in transparency, heat resistance, and melt processability, and is an optical film used in image display devices such as liquid crystal displays and organic EL displays. It is suitable for use as a diffusion sheet, or an optical lens such as a camera lens, a finder lens, a CCD lens or a CMOS lens, and can also be used for an optical disk, an optical prism, or the like.

  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 characteristics of the resin of the present invention and the retardation film 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) 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) Melt viscosity A 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.
In the following examples and comparative examples, those having a melt viscosity of 2000 Pa · s or more and 6000 Pa · s or less can be melt processed in a temperature range in which the thermoplastic resin maintains practical strength and can suppress thermal deterioration. Evaluated that there was.

(3) Glass transition temperature (Tg)
This was measured using a differential scanning calorimeter DSC 6220 manufactured by SII Nano Technology. 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 250 ° 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.

(4) Measurement of content of monohydroxy compound and carbonic acid diester in thermoplastic resin Weigh accurately about 1 g of resin sample, dissolve in 5 mL of methylene chloride to make a solution, then add acetone so that the total amount is 25 mL Then, reprecipitation treatment 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 .
In the following Examples and Comparative Examples, the monohydroxy compound in the thermoplastic resin is 600 ppm or less and the residual amount of carbonic acid diester is 100 ppm or less, preventing contamination of the molding machine during molding and poor appearance of the molded product. It was evaluated as excellent.

(5) Molding of film The resin pellets vacuum-dried at 90 ° C. for 5 hours or longer were converted into T using a single screw extruder (screw diameter 25 mm, cylinder set temperature: 220 to 260 ° C.) manufactured by Isuzu Chemical Industries, Ltd. It extruded from the die | dye (width 200mm, setting temperature: 200-260 degreeC). 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.

(6) Measurement of refractive index and Abbe number From the film produced by the method of (5), a rectangular test piece having a length of 40 mm and a width of 8 mm was cut out to obtain a measurement sample. Refractive index n _C of each wavelength by multi-wavelength Abbe refractometer DR-M4 / 1550 manufactured by Atago Co., Ltd. using interference filters with wavelengths of 656 nm (C line), 589 nm (D line), and 486 nm (F line) n _D and n _F were measured. The measurement was performed at 20 ° C. using monobromonaphthalene as the interfacial liquid. The Abbe number ν _d was calculated by the following equation.
ν _d = (1−n _D ) / (n _C −n _F )
The larger the Abbe number, the smaller the wavelength dependency of the refractive index.
In the following examples and comparative examples, those having a refractive index of 1.55 or more at a wavelength of 589 nm were evaluated as having a large refractive index and suitable for applications such as an optical lens.

(7) Measurement of total light transmittance Using Nippon Denshoku Industries Co., Ltd. turbidimeter COH400, the total light transmittance of the film produced by the method of (5) was measured.
In the following examples and comparative examples, those having a total light transmittance of 89% or more were evaluated as being excellent in 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). It measured using. (For details, see Journal of Japanese Society of Rheology, Vol. 19, p93-97 (1991).)

A sample having a length of 20 mm and a width of 5 mm was cut out from the film produced by the method (5), fixed to a viscoelasticity measuring device, 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'
In the following examples and comparative examples, those having a photoelastic coefficient of 30 × 10 ⁻¹² Pa ⁻¹ or less are those of birefringence caused by elastic deformation of the member when the film is incorporated into the optical member. It was evaluated that it was excellent in preventing expression.

(9) Production of stretched film A film piece having a length of 125 mm and a width of 50 mm was cut out from the film produced by the method of (5). Using a batch-type biaxial stretching apparatus (biaxial stretching apparatus BIX-277-AL manufactured by Island Kogyo Co., Ltd.), stretching speed: 300% / min, stretching ratio: 1.5 times, stretching temperature: glass transition temperature of resin + 15 The film piece was subjected to free-end uniaxial stretching under the condition of ° C. to produce a stretched film.

(10) Measurement of retardation of molded product and measurement of birefringence (Δn) The central part of the stretched film produced by the method of (9) is cut into a length of 40 mm and a width of 40 mm, and a phase difference measurement manufactured by Oji Scientific Instruments Co., Ltd. Using the apparatus KOBRA-WPR, the phase difference was measured at measurement wavelengths of 450, 500, 550, 590, and 630 nm, and the wavelength dispersion was measured. From the retardation R550 having a wavelength of 550 nm and the film thickness of the stretched film, the orientation birefringence Δn was determined from the following formula. When the slow axis direction coincides with the stretching direction, Δn is a positive value, and when the slow axis direction coincides with the direction perpendicular to the stretching direction, Δn is a negative value. Indicated.
Orientation birefringence Δn = R550 [nm] / (film thickness [mm] × 10 ⁶ )

(Example of monomer synthesis)
[Synthesis Example 1] Synthesis of bis [9- (2-phenoxycarbonylethyl) fluoren-9-yl] methane (the following formula (16))

  Synthesis Example 2 Synthesis of 1,2-bis [9- (3-hydroxypropyl) -fluoren-9-yl] methane (the following formula (17))

  [Synthesis Example 3] Synthesis of 1,2-bis (9-hydroxymethylfluoren-9-yl) ethane (the following formula (18))

  [Synthesis Example 4] Synthesis of bis [9- (2-ethoxycarbonylethyl) fluoren-9-yl] methane (the following formula (19))

The four compounds of Synthesis Examples 1 to 4 were synthesized according to the method described in JP-A-2015-25111.
Synthesis Example 5 Synthesis of 6,6′-dihydroxy-3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane (the following formula (20))
The compound was synthesized according to the method described in JP-A No. 2014-114281.

[Synthesis example of thermoplastic resin and evaluation of physical properties]
Abbreviations and the like of compounds used in the following examples and comparative examples are as follows.
BF1: bis [9- (2-phenoxycarbonylethyl) fluoren-9-yl] methane BF2: 1,2-bis [9- (3-hydroxypropyl) -fluoren-9-yl] methane BF3: 1 , 2-bis (9-hydroxymethylfluoren-9-yl) ethane.BF4: bis [9- (2-ethoxycarbonylethyl) fluoren-9-yl] methane.SBI: 6,6'-dihydroxy-3,3 , 3 ′, 3′-tetramethyl-1,1′-spirobiindane ISB: isosorbide (trade name: POLYSORB, manufactured by Rocket Fleure)
CHDM: 1,4-cyclohexanedimethanol (cis, trans mixture, manufactured by SK Chemical Company)
-TCDDM: Tricyclodecane dimethanol (Oxea)
・ SPG: Spiroglycol (Mitsubishi Gas Chemical Co., Ltd.)
・ EG: Ethylene glycol (Mitsubishi Chemical Corporation)
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.)
・ DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation)
・ TBT: Tetrabutoxy titanium (manufactured by Tokyo Chemical Industry Co., Ltd.)

[Example 1-1]
ISB 24.41 parts by weight (0.167 mol), BF1 107.03 parts by weight (0.167 mol), and calcium acetate monohydrate 2.20 × 10 ⁻² parts by weight (1.25 × 10 ⁻⁴ as catalyst) mol) was charged into the reaction vessel, and the inside of the reaction apparatus 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. In the first step of the reaction, the temperature was raised to 240 ° 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 260 ° 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 restoring the pressure to normal pressure with nitrogen, the produced polyester was extruded into water, and the strand was cut to obtain pellets. Various evaluations described above were performed using the obtained polyester pellets. The evaluation results are shown in Table 1.

The resin of Example 1-1 showed high orientation in the negative direction. Furthermore, since the glass transition temperature is as high as 160 ° C. and the melt viscosity is large, it is excellent in heat resistance, melt processability and mechanical properties, has a high total light transmittance, and has a low photoelastic coefficient, so it has excellent optical characteristics. Moreover, since the refractive index in wavelength 589nm is also high, it can use suitably for uses, such as an optical lens, for example. And since there is also little residual phenol amount, the contamination to the molding machine at the time of shaping | molding and the external appearance defect of a molded product can also be prevented.

[Example 1-2]
ISB 20.80 parts by weight (0.142 mol), SBI 5.99 parts by weight (0.019 mol), BF1 103.66 parts by weight (0.162 mol), and calcium acetate monohydrate 2.20 × 10 as catalyst. ^It carried out like Example 1-1 except having used ^-2 weight part (1.25 * 10 <^-4> mol). Various evaluations described above were performed using the obtained polyester pellets. The evaluation results are shown in Table 1.

  The resin containing the aryl ester structure of Example 1-2 shows high orientation in the negative direction as in Example 1-1, and has excellent heat resistance, thermal workability, mechanical properties, and optical characteristics. Excellent resin. In particular, compared with Example 1-1, Example 1-2 has a higher glass transition temperature and a preferable melt viscosity, and thus is more excellent in heat resistance and melt processability. Further, since the amount of residual phenol is smaller than that in Example 1, it is possible to further prevent contamination of the molding machine and defective appearance of the molded product during molding.

[Example 1-3]
33.53 parts by weight (0.147 mol) of BPA, 94.12 parts by weight (0.147 mol) of BF1, and 8.79 × 10 ⁻² parts by weight (4.99 × 10 ⁻⁴ ) of calcium acetate monohydrate as a catalyst mol) was carried out in the same manner as in Example 1-1. Various evaluations described above were performed using the obtained polyester (polyarylate) pellets. The evaluation results are shown in Table 1.

  The resin containing the aryl ester structure of Example 1-3 exhibits orientation birefringence in the negative direction as in Example 1-1, and is excellent in heat resistance, melt processability, mechanical properties, and optical properties. Yes. In particular, since the glass transition temperature is higher than that of Example 1-1 and the melt viscosity is preferable, it is further excellent in heat resistance and melt processability. On the other hand, although the photoelastic coefficient showed a high value compared with Example 1-1, since it has a high refractive index, it can be used suitably for uses, such as an optical lens, for example.

[Example 1-4]
24.17 parts by weight (0.168 mol) of CHDM, 107.38 parts by weight (0.168 mol) of BF1, and 2.20 × 10 ⁻² parts by weight (1.25 × 10 ⁻⁴ ) of calcium acetate monohydrate as a catalyst mol) was carried out in the same manner as in Example 1-1. Various evaluations described above were performed using the obtained polyester pellets. The evaluation results are shown in Table 1.

[Example 1-5]
TCDDM 30.25 parts by weight (0.154 mol), BF1 98.76 parts by weight (0.154 mol), and calcium acetate monohydrate 2.20 × 10 ⁻² parts by weight (1.25 × 10 ⁻⁴ as catalyst) mol) was carried out in the same manner as in Example 1-1. Various evaluations described above were performed using the obtained polyester pellets. The evaluation results are shown in Table 1.

[Example 1-6]
40.21 parts by weight (0.132 mol) of SPG, 84.65 parts by weight (0.132 mol) of BF1, and 2.20 × 10 ⁻² parts by weight (1.25 × 10 ⁻⁴ ) of calcium acetate monohydrate as a catalyst mol) was carried out in the same manner as in Example 1-1. Various evaluations described above were performed using the obtained polyester pellets. The evaluation results are shown in Table 1.

  Examples 1-4 to 1-6 are polyesters containing structural units derived from alicyclic dihydroxy compounds, exhibiting orientation birefringence in the negative direction as in Example 1-1, and are heat resistant. It has excellent properties, melt processability, mechanical properties and optical properties. In particular, since the amount of residual phenol is smaller than in Example 1-1, it is possible to prevent the molding machine from being contaminated during molding and appearance defects of the molded product. Moreover, although the photoelastic coefficient of Example 1-4 showed the high value compared with Example 1-1, since it has a high refractive index, it can be used suitably for uses, such as an optical lens, for example. it can. On the other hand, although the refractive index of Example 1-5 and Example 1-6 showed the small value compared with Example 1-1, since the photoelastic coefficient is small, when it is set as an optical member, the circumference | surroundings of a screen This is particularly effective for preventing the deterioration of image quality such as white blurring.

[Example 1-7]
49.21 parts by weight (0.112 mol) of BHEPF, 71.91 parts by weight (0.112 mol) of BF1, and 2.20 × 10 ⁻² parts by weight (1.25 × 10 ⁻⁴ ) of calcium acetate monohydrate as a catalyst mol) was carried out in the same manner as in Example 1-1. Various evaluations described above were performed using the obtained polyester pellets. The evaluation results are shown in Table 1.
Example 1-7 is a polyester containing the structural unit represented by the above formula (4), and exhibits negative orientation as in Example 1-1, and has heat resistance, melt processability, and mechanical properties. And excellent optical properties. In particular, it has a very high refractive index compared to Example 1-1, and can be suitably used for applications such as an optical lens.

[Example 1-8]
38.46 parts by weight (0.125 mol) of SBI, 55.19 parts by weight (0.120 mol) of BF2, 53.95 parts by weight (0.252 mol) of DPC, and 4.31 × 10 calcium acetate monohydrate as a catalyst ^-4 parts by weight (2.45 × 10 ⁻⁶ mol) was used, and the same procedure as in Example 1-1 was performed except that the temperature of the first stage of the reaction was 220 ° C. and the temperature of the second stage of the reaction was 250 ° C. . Various evaluations described above were performed using the obtained polycarbonate pellets. The evaluation results are shown in Table 1.
The resin of Example 1-8 exhibits negative orientation as in Example 1-1, and is excellent in good balance in heat resistance, melt processability, mechanical properties, and optical characteristics.

[Comparative Example 1-1]
BHEPF 94.40 parts by weight (0.215 mol), DPC 46.12 parts by weight (0.215 mol), and calcium acetate monohydrate 1.14 × 10 ⁻³ parts by weight (6.46 × 10 ⁻⁶ as catalyst) mol), and the same procedure as in Example 1-1 was performed except that the temperature of the first stage of the reaction was 220 ° C. and the temperature of the second stage of the reaction was 250 ° C. Various evaluations described above were performed using the obtained polycarbonate pellets. The evaluation results are shown in Table 1.
Comparative Example 1 is a polycarbonate containing a structural unit represented by the above formula (4) having a fluorene structure in the side chain as in the oligofluorene structural unit of the present invention, The orientation is insufficient for use as a retardation film. Moreover, the photoelastic coefficient is also high and it is inferior to various optical characteristics compared with an Example.

[Comparative Example 1-2]
ISB 74.54 parts by weight (0.510 mol), BF1 18.33 parts by weight (0.029 mol), DPC 103.14 parts by weight (0.481 mol), and calcium acetate monohydrate 8.99 × 10 6 as the catalyst ^-4 parts by weight (5.10 × 10 ⁻⁶ mol) was used, and the same procedure as in Example 1-1 was performed except that the temperature of the first stage of the reaction was 220 ° C. and the temperature of the second stage of the reaction was 250 ° C. . Various evaluations described above were performed using the obtained polyester carbonate pellets. The evaluation results are shown in Table 1.
Comparative Example 1-2 showed positive orientation. In addition, the refractive index at a wavelength of 589 nm is small as compared with the examples, and it is not suitable for film thinning. In addition, the amount of phenol remaining in the resin is large, which may cause contamination of the molding machine during molding and poor appearance of the molded product, resulting in poor productivity.

[Comparative Example 1-3]
CHDM 6.06 parts by weight (0.042 mol), CHDA 34.45 parts by weight (0.200 mol), BF3 66.99 parts by weight (0.160 mol), and TBT 7.11 × 10 ⁻³ parts by weight as catalyst ( 2.09 × 10 ⁻⁵ mol), and the same procedure as in Example 1-1 was performed except that the temperature of the first stage of the reaction was 220 ° C. and the temperature of the second stage of the reaction was 250 ° C. Various evaluations described above were performed using the obtained polyester pellets. The evaluation results are shown in Table 1.

  Comparative Example 1-3 is a polyester containing an oligofluorene structure similar to that of the example, but unexpectedly did not exhibit negative orientation and exhibited positive orientation. In addition, the photoelastic coefficient is high, and there is a possibility of causing unnecessary birefringence when the optical member is formed. This is presumed that the distance between the carbonyl group and the fluorene ring in the oligofluorene structural unit is too close, and the fluorene ring cannot be oriented in a preferred direction due to the steric hindrance of the carbonyl group. As described above, the molecular design of the oligofluorene structural unit is important in order to develop ideal optical properties.

[Comparative Example 1-4]
BF2 94.66 parts by weight (0.206 mol), DPC 44.24 parts by weight (0.207 mol), and calcium acetate monohydrate 3.62 × 10 ⁻⁴ parts by weight (2.06 × 10 ⁻⁶ as a catalyst) mol), and the same procedure as in Example 1-1 was performed except that the temperature of the first stage of the reaction was 220 ° C. and the temperature of the second stage of the reaction was 240 ° C. Various evaluations described above were performed using the obtained polycarbonate pellets. The evaluation results are shown in Table 1.

  Comparative Example 1-4 is a polycarbonate containing an oligofluorene structural unit as in the Examples, and although it exhibited high negative orientation, it has poor heat resistance because of its low glass transition temperature, and it has low melt viscosity, so heating is performed. May cause thermal degradation in the accompanying process. Since BF2 has a large number of carbon atoms in the alkylene chain constituting the main chain, it is presumed that the fixation of the orientation of the fluorene ring in the side chain is weakened. In addition, the amount of phenol remaining in the resin is large, which may cause contamination of the molding machine during molding and poor appearance of the molded product, resulting in poor productivity.

[Comparative Example 1-5]
EG 12.66 parts by weight (0.204 mol), BF1 124.51 parts by weight (0.194 mol), and calcium acetate monohydrate 4.40 × 10 ⁻² parts by weight (2.50 × 10 ⁻⁴ as catalyst) mol) was carried out in the same manner as in Example 1-1. Various evaluations described above were performed using the obtained polyester pellets. The evaluation results are shown in Table 1.
Comparative Example 1-5 is a polyester using a linear aliphatic dihydroxy compound, and exhibited a large orientation birefringence in the negative direction, but has a very low glass transition temperature and melt viscosity as compared with the Examples. Since the glass transition temperature is low and the heat resistance is inferior, the molded product may be deformed in a process involving heating, or the reliability of optical properties in the environment of use of the product may be reduced. Further, since the melt viscosity is low, for example, when melt extrusion molding is performed, there is a possibility that processability is deteriorated and the film thickness accuracy of the film or sheet is deteriorated, or the strength of the resin is lowered.

[Comparative Example 1-6]
Various evaluations described above were performed using polystyrene (G9504 manufactured by PS Japan Co., Ltd.). The evaluation results are shown in Table 1.
Polystyrene is a general-purpose material that develops negative orientation, but its glass transition temperature and melt viscosity are extremely low compared to the examples. Since the glass transition temperature is low and the heat resistance is inferior, the molded product may be deformed in a process involving heating, or the reliability of optical properties in the environment of use of the product may be reduced. In addition, if the melt viscosity is low, the processability may be reduced in melt extrusion molding, the film thickness accuracy of the film or sheet is deteriorated, the strength of the resin is reduced, and the film is broken when the film is transported. There is a case. In addition, since the refractive index at a wavelength of 589 nm is low, it is not effective in reducing the film thickness.

[Example 2-1] to [Example 2-5]
With the composition shown in Table 2, a polymerization reaction was performed in the same manner as in Example 1-1. Under any conditions, the reaction proceeded smoothly until a predetermined melt viscosity was reached at the charged amount.

[Comparative Example 2-1] to [Comparative Example 2-8]
The diester compound was changed from BF1 to BF4, and a polymerization reaction was performed in the same manner as in Example 1-1 with the composition shown in Table 2. Since the progress of the polymerization reaction was slower than in Example 2-1 to Example 2-5, the polymerization was performed while increasing the amount of catalyst during the reaction. However, except for Comparative Example 2-4, the desired molecular weight was obtained. A thermoplastic resin could not be obtained.

  From this evaluation result, BF1, which is a diaryl ester used in the polymerization reaction, is superior in reactivity to BF4, which is a dialkyl ester, and can be polymerized with a smaller amount of polymerization catalyst. It can be seen that dihydroxy compounds that are difficult to react can also be applied.

Claims (14)

A thermoplastic resin containing a structural unit represented by the following formula (1) or (2) and satisfying the following (A) and (B).
(A) The orientation birefringence of the stretched film made of the resin at a wavelength of 550 nm is −0.0015 or less.
(B) The glass transition temperature of the resin is 120 ° C. or higher and 180 ° C. or lower.

(In Formula (1) and (2), R < ¹ > -R < ³ > is a C1-C4 alkylene group which may have a direct bond and a substituent each independently, R < ⁴ > -R < ⁹ >. 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 silicon having a substituent. Atom, a halogen atom, a nitro group, or a cyano group. However, they may form a ring adjacent the at least two groups are bonded to each other among the R ⁴ to R ^9.) A thermoplastic resin containing a structural unit represented by the following formula (3).

(In the formula ^(3), R 1 to R ⁹ are the same .Ar ¹ and ^R 1 to R ⁹ in the formula (1) and (2) is a structural unit derived from the dihydric phenol compound.) A thermoplastic resin comprising a structural unit represented by the formula (1) or (2) and a structural unit represented by the following formula (4).

(In the formula (4), R ^{10 to} R ¹¹ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or 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, Ar ² and Ar ³ each independently represents a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and X is substituted or unsubstituted. It represents a substituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 6 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, wherein m and n are each independent. (It is an integer of 0 to 5.)   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 formula (1) or (2) is contained by 50% by weight or more. Item 4. The thermoplastic resin according to any one of Items 1 to 3.   The thermoplastic resin according to any one of claims 1 to 4, wherein the thermoplastic resin is polyester. The thermoplastic resin of any one of Claims 1 thru | or 5 containing the structural unit represented by following formula (5).

  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 the formula (2) is contained by 50% by weight or more, and the alicyclic dihydroxy Polyester containing a structural unit derived from a compound. The polyester according to claim 7, wherein the structural unit derived from the alicyclic dihydroxy compound is a structural unit represented by the following formula (5).

  The transparent film formed by shape | molding the thermoplastic resin of any one of Claims 1 thru | or 4.   A transparent film formed by molding the polyester according to any one of claims 5 to 9.   An injection-molded product obtained by injection-molding the thermoplastic resin according to any one of claims 1 to 4.   An injection-molded product obtained by injection-molding the polyester according to any one of claims 5 to 9. A method for producing a polyester, comprising subjecting a compound represented by the following formula (6) and a dihydroxy compound to melt polycondensation in the presence of a polymerization catalyst.

(In the formula ^(6), R 1 to R ⁹ is the formula (1) and (2) of ^R 1 to R ⁹ equal .Ar ⁴ and Ar ⁵ aromatic may have a substituent, respectively carbide It is a hydrogen group, and Ar ⁴ and Ar ⁵ may be the same or different.) The method for producing a polyester according to claim 13, wherein the dihydroxy compound is a dihydroxy compound represented by the following formula (7) or a divalent phenol compound.