JP2011168742A - Polycarbonate resin of low photoelastic constant, and optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate resin having a low photoelastic constant, good fluidity and excellent thermal stability, wherein the polycarbonate resin can give a film having wavelength dispersion suitable to optical applications such as a retardation film and a polarizer protective film, and to provide an optical film made of the polycarbonate resin. <P>SOLUTION: The polycarbonate resin has a repeating unit (A) as its main repeating unit and a specific viscosity of 0.20-1.50 measured with a methylene chloride solution at 20°C. The optical film made of the polycarbonate resin shows optional wavelength dispersion. In the formula of the repeating unit (A), R<SB>1</SB>, R<SB>2</SB>, R<SB>3</SB>, R<SB>4</SB>, R<SB>5</SB>and R<SB>6</SB>each independently indicate a hydrogen atom or a 1-10C hydrocarbon group; R<SB>1</SB>and R<SB>2</SB>may combine with each other to form a carbon ring or a heterocycle; R<SB>4</SB>and R<SB>5</SB>may combine with each other to form a carbon ring or a heterocycle; and m and n indicate the same or different integer of 1-4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polycarbonate resin having a low photoelastic constant, good fluidity, and excellent thermal stability, and an optical film having desired wavelength dispersion characteristics.

  Conventionally, a polycarbonate resin (hereinafter referred to as PC-A) obtained by reacting a carbonate precursor with 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) has transparency, heat resistance, mechanical properties. It has been widely used in many fields as an engineering plastic because of its excellent characteristics and dimensional stability. Furthermore, in recent years, utilization of the transparency as an optical material in the fields of optical disks, films, lenses and the like has been developed.

  However, when PC-A is used, since positive birefringence is high and the photoelastic constant is high, optical distortion occurs when used as an optical application, causing various problems. For example, when used in an optical lens, there is a drawback that the birefringence of the molded product increases. In addition, when used as a retardation film, there is a problem that the change in birefringence due to stress is large and light leakage occurs, and the wavelengths that can function as λ / 4 plates and λ / 2 plates are limited to specific wavelengths. It was.

  Therefore, various methods have been studied as countermeasures against the above problems. As one of them, it is proposed that a polycarbonate resin having a low photoelastic coefficient can be obtained by reacting a carbonate precursor with bisphenol A and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (for example, Patent Documents). 1), it is proposed to use a film made of the polycarbonate resin for a retardation film and a protective film for a polarizing plate (for example, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5). reference). However, since the glass transition temperature (Tg) is high and the fluidity is low, there is a problem that a high temperature is required for stretching the film and special processing equipment different from the conventional one is required.

As another method, tricyclo (5.2.1.0 ^2.6 ) decandimethanol, which is an aliphatic diol, and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, which is an aromatic diol, are used. It is known that when a carbonate precursor is reacted, a polycarbonate resin having a lower photoelastic constant than a reaction between aromatic diols and a low glass transition temperature and good fluidity can be obtained (for example, Patent Document 6, (See Patent Document 7). However, since this polycarbonate resin has a low thermal decomposition temperature, generation of bubbles, gels, and the like due to decomposition during production by melt film formation has been a problem.

  Therefore, a polycarbonate resin that has a low photoelastic constant, fluidity suitable for molding, and excellent thermal stability, and can realize wavelength dispersion suitable for optical applications such as retardation films and protective films for polarizing plates. And an optical film using the same has not been provided yet.

JP 2004-331688 A International Publication No. 2000/026705 Pamphlet International Publication No. 01/009649 Pamphlet JP 2001-296423 A JP 2001-194530 A JP 2000-169573 A International Publication No. 2006/041190 Pamphlet

  The object of the present invention is to provide a wavelength dispersion suitable for optical applications such as a retardation film and a protective film for a polarizing plate when the film has a low photoelastic constant, good fluidity, excellent thermal stability, and a film. It is to provide a polycarbonate resin that can be developed and an optical film using the same.

  As a result of intensive research, the inventors of the present invention are suitable for low photoelastic constant and molding by reacting a carbonate precursor with a fluorbisphenol compound having a steric hindrance alkyl group, a fluorene structure, and an aromatic diol. We have determined that a polycarbonate resin with high fluidity and excellent thermal stability can be obtained. Furthermore, the inventors have investigated that by using this resin as a film, it is possible to develop wavelength dispersion suitable for optical applications such as a retardation film and a protective film for a polarizing plate, and the present invention has been completed.

［式中、Ｒ₁、Ｒ_２、Ｒ_３、Ｒ_４、Ｒ_５、Ｒ_６は夫々独立して、水素原子、炭素原子数１〜１０の炭化水素基であり、Ｒ₁、Ｒ_２が結合して炭素環、もしくは複素環を形成しても良い。また、Ｒ_４、Ｒ_５が結合して炭素環、もしくは複素環を形成しても良い。ｍおよびｎは同一または異なる１〜４の整数を示す。］
で表される繰り返し単位（Ａ）と下記式

［式（Ｂ）中、Ｒ_７、Ｒ_８は夫々独立して水素原子、炭素原子数１〜９の芳香族基を含んでもよい炭化水素基又はハロゲン原子であり、ｐおよびｑは同一または異なる１〜４の整数を示す。Ｗは、下記式（Ｗ）

であり、ここにＲ_９とＲ_１０はそれぞれ、水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素原子数１〜９のアルキル基、炭素原子数１〜５のアルコキシ基、炭素原子数６〜１２のアリール基、炭素原子数２〜５のアルケニル基、又は炭素原子数７〜１７のアラルキル基を表す。また、Ｒ_９とＲ_１０が結合して炭素環または複素環を形成しても良い。
Ｒ_１１とＲ_１２はそれぞれ、水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素原子数１〜９のアルキル基、炭素原子数１〜５のアルコキシ基、又は炭素原子数６〜１２アリール基を表す。Ｒ_１３は炭素原子数１〜９のアルキレン基である。ａは０〜２０の整数を表し、ｂは１〜５００の整数を表す。］
で表される繰り返し単位（Ｂ）を含み、それら繰り返し単位（Ａ）と繰り返し単位（Ｂ）とのモル比（Ａ／Ｂ）が４０／６０以上１００／０未満の範囲で、２０℃の塩化メチレン溶液で測定された比粘度が０．２０〜１．５０であることを特徴とするポリカーボネート樹脂。 That is, the present invention is as follows.
1. The main repeating unit is the following formula

[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and R ₁ and R ₂ are bonded to each other. Thus, a carbocycle or a heterocycle may be formed. R ₄ and R ₅ may combine to form a carbocyclic or heterocyclic ring. m and n represent the same or different integers of 1 to 4. ]
The repeating unit (A) represented by the following formula

[In formula (B), R ₇ and R ₈ are each independently a hydrogen atom, a hydrocarbon group which may contain an aromatic group having 1 to 9 carbon atoms, or a halogen atom, and p and q are the same or different. An integer of 1 to 4 is shown. W is the following formula (W)

Where R ₉ and R ₁₀ are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a carbon atom. An aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms is represented. R ₉ and R ₁₀ may combine to form a carbocyclic or heterocyclic ring.
R ₁₁ and R ₁₂ are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or 6 to 12 carbon atoms. Represents an aryl group. R ₁₃ is an alkylene group having 1 to 9 carbon atoms. a represents an integer of 0 to 20, and b represents an integer of 1 to 500. ]
In the range where the molar ratio (A / B) between the repeating unit (A) and the repeating unit (B) is 40/60 or more and less than 100/0, A polycarbonate resin having a specific viscosity of 0.20 to 1.50 measured with a methylene solution.

［式中、Ｒ₁、Ｒ_２、Ｒ_３、Ｒ_４、Ｒ_５、Ｒ_６は夫々独立して、水素原子、炭素原子数１〜１０の炭化水素基であり、Ｒ₁、Ｒ_２が結合して炭素環、もしくは複素環を形成しても良い。また、Ｒ_４、Ｒ_５が結合して炭素環、もしくは複素環を形成しても良い。］
で表される繰り返し単位（Ａ１）である上記１記載のポリカーボネート樹脂。 2. The repeating unit (A) is represented by the following formula

[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and R ₁ and R ₂ are bonded to each other. Thus, a carbocycle or a heterocycle may be formed. R ₄ and R ₅ may combine to form a carbocyclic or heterocyclic ring. ]
2. The polycarbonate resin according to the above 1, which is a repeating unit (A1) represented by

で表される繰り返し単位（Ａ２）、（Ａ３）、および（Ａ４）からなる群より選ばれる少なくとも一種である上記１記載のポリカーボネート樹脂。 3. The repeating unit (A) is represented by the following formula

2. The polycarbonate resin according to 1 above, which is at least one selected from the group consisting of repeating units (A2), (A3), and (A4) represented by:

4). An unstretched film formed using the polycarbonate resin described in 1 above.
5. The unstretched film according to 4 above is stretched, and the following formula (1)
R (450) <R (550) <R (650) (1)
[However, R (450), R (550), and R (650) represent retardation values in the film plane at wavelengths of 450 nm, 550 nm, and 650 nm, respectively. ]
A stretched film that satisfies
6). The following formulas (2) and (3)
0 <R (450) / R (550) <1.00 (2)
1.01 <R (650) / R (550) <2.00 (3)
6. The stretched film according to 5 above, wherein
7). Following formula (4)-(6)
−30 <R (450) <0 (4)
−10 <R (550) <10 (5)
0 <R (650) <30 (6)
6. The stretched film according to 5 above, wherein
8). Following formula (7)
R (650) <0 (7)
6. The stretched film according to 5 above, wherein
9. 6. A circularly polarizing film comprising the stretched film as described in 5 above and a polarizing layer.
10. 6. A liquid crystal display device comprising the stretched film according to 5 above.
11. 10. A display device using the circularly polarizing film as described in 9 above as an antireflection film.

  The polycarbonate resin of the present invention has a low photoelastic constant, fluidity suitable for molding, and excellent heat by reacting a carbonate precursor with a fluorbisphenol compound having a large steric hindrance and a fluorene structure and an aromatic diol. It became possible to have stability.

  Furthermore, by using the polycarbonate resin of the present invention, an optical film having a low photoelastic constant, excellent thermal stability, and wavelength dispersion suitable for optical applications such as a retardation film and a protective film for a polarizing plate is provided. It became possible to do. Therefore, the industrial effect that it produces is exceptional.

It is explanatory drawing of the thermal nonuniformity evaluation of an Example. It is explanatory drawing of light omission evaluation of an Example.

Hereinafter, the present invention will be described in detail.
<Polycarbonate resin>
In the polycarbonate resin of the present invention, the main repeating unit is composed of the repeating unit (A) and the repeating unit (B).

(Repeating unit (A))
The repeating unit (A) used in the present invention is derived from a fluorbisphenol compound having a steric hindrance alkyl group and a fluorene structure, as shown in the formula (A). In the formula (A), R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and R ₁ , R ₂ may combine to form a carbocyclic or heterocyclic ring. R ₄ and R ₅ may combine to form a carbocyclic or heterocyclic ring. m and n represent the same or different integers of 1 to 4. Examples of the hydrocarbon group include an alkyl group having 1 to 10 carbon atoms and a cycloalkyl group having 5 to 10 carbon atoms. Preferably, it is represented by the formula (A1). Specifically, 9,9-bis (4-hydroxy-3-isopropylphenyl) fluorene, 9,9-bis (4-hydroxy-3-isobutylphenyl) fluorene, 9,9-bis (4-hydroxy-3) -Sec-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-tert-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-isopentylphenyl) fluorene, 9,9-bis Examples are repeating units derived from (4-hydroxy-3-cyclohexylphenyl) fluorene, 9,9-bis (4-hydroxy-3-cyclopentylphenyl) fluorene and the like. In particular, 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-tert-butylphenyl) fluorene, 9,9-bis (4-hydroxy-) The repeating unit represented by the above formulas (A2), (A3), and (A4) derived from 3-cyclohexylphenyl) fluorene has a photoelasticity because the alkyl group having a large steric hindrance suppresses the rotation of the phenyl group. Since it is estimated that it becomes low, it is preferable. Among these, (A2) is more preferable because it greatly increases the fluidity and is excellent in moldability.

(Repeating unit (B))
The repeating unit (B) according to the present invention is a carbonate unit having an aromatic structure as shown in the formula (B). In the formula (B), R ₇ and R ₈ are a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, and the number of carbon atoms. 7 to 13 aralkyl groups and one selected from halogen are shown, p and q are the numbers of R ₇ and R ₈ substituted on the benzene ring, and are integers of 1 to 4. Preferably, R ₇ and R ₈ are alkyl groups having 1 to 4 carbon atoms, aryl groups having 6 to 9 carbon atoms, alkenyl groups having 2 to 5 carbon atoms, aralkyl groups having 7 to 9 carbon atoms, and 1 type selected from halogen. More preferably, they are a methyl group, a cyclohexyl group, or a phenyl group. R ₉ and R ₁₀ are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 6 to 12 carbon atoms. An aryl group, an alkenyl group having 2 to 5 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms is represented. R ₉ and R ₁₀ may combine to form a carbocyclic or heterocyclic ring. R ₁₁ and R ₁₂ are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or 6 to 12 carbon atoms. Represents an aryl group. R ₁₃ is an alkylene group of 1 to 9. a represents an integer of 0 to 20, and b represents an integer of 1 to 500. Specifically, 4,4′-biphenol, 1,1-bis (4-hydroxyphenyl) ethane (bisphenol E), 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2- Bis (4-hydroxy-3-methylphenyl) propane (bisphenol C), 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1 -Bis (4-hydroxyphenyl) cyclohexane (bisphenol Z), 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis (4-hydroxyphenyl) pentane, α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene (bisphenol M), 1,1-bis (4-hydride) Roxyphenyl) -4-isopropylcyclohexane and the like are exemplified. Of these, bisphenol A, bisphenol Z, bisphenol C, bisphenol E, and bisphenol M are preferable from the viewpoint of heat resistance and fluidity, and bisphenol A is particularly preferable from the viewpoint of high fluidity and availability. Two or more of these may be used in combination.

(Composition ratio)
In the composition ratio of the polycarbonate resin of the present invention, the molar ratio (A / B) of the main repeating unit (A) to the repeating unit (B) is 40/60 or more and less than 100/0. When the polycarbonate resin of the present invention having a molar ratio (A / B) of 40/60 or more is formed into a film, the wavelength dispersion of the film is suitable for optical applications such as a retardation film and a protective film for a polarizing plate. This is preferable. The molar ratio (A / B) is preferably 50/50 or more and 98/2 or less, more preferably 60/40 or more and 95/5 or less. The inclusion of the repeating unit (B) is preferable in terms of control of fluidity and wavelength dispersion. The molar ratio (A / B) is measured and calculated by proton NMR of JNM-AL400 manufactured by JEOL. The main repeating unit is a total of repeating units (A) and (B) of 90 mol% or more, preferably 95 mol% or more, more preferably 100 mol%, based on all repeating units.

(Specific viscosity: η _SP )
The specific viscosity (η _SP ) of the polycarbonate resin of the present invention is in the range of 0.20 to 1.50. If it exceeds 0.20, the strength and the like are improved, and if it is lower than 1.50, the molding characteristics are excellent. Preferably, it is the range of 0.25-1.20, Especially preferably, it is the range of 0.30-1.00. You may use together with other resin in the range which does not impair the effect of this invention.

The specific viscosity referred to in the present invention was determined using an Ostwald viscometer from a solution obtained by dissolving 0.7 g of a polycarbonate resin in 100 ml of methylene chloride at 20 ° C.
Specific viscosity (η _SP ) = (t−t ₀ ) / t ₀
[T ₀ is methylene chloride falling seconds, t is sample solution falling seconds]

  In addition, when measuring the specific viscosity of the polycarbonate resin of this invention, it can carry out in the following way. That is, the polycarbonate resin is dissolved in 20 to 30 times the weight of methylene chloride, and the soluble component is collected by celite filtration, and then the solution is removed and dried sufficiently to obtain a solid component soluble in methylene chloride. Using a Ostwald viscometer, the specific viscosity at 20 ° C. is determined from a solution of 0.7 g of the solid dissolved in 100 ml of methylene chloride.

(Glass transition temperature: Tg)
The glass transition temperature (Tg) of the polycarbonate resin of the present invention is preferably 130 to 220 ° C, more preferably 140 to 200 ° C, and particularly preferably 140 to 160 ° C. When Tg is equal to or higher than the lower limit, the heat resistance stability is good, and it is preferable that the retardation value hardly changes when used as a retardation film. Moreover, in the range where Tg does not exceed the upper limit, a high temperature is not necessary for stretching the film, and a special processing facility different from the conventional one is not required, which is preferable. Tg is estimated to be lower due to the introduction of an alkyl group. Tg is measured by using a 2910 type DSC manufactured by TA Instruments Japan Co., Ltd. at a heating rate of 20 ° C./min.

(Thermal decomposition temperature: Td)
The polycarbonate resin of the present invention preferably has a temperature of 5% weight loss due to heat of 380 ° C. or higher, particularly preferably 400 ° C. or higher. If the 5% weight loss temperature is 380 ° C. or less, decomposition is likely to occur during melt film formation, and foreign matter may be generated, which may affect display quality. The temperature of 5% weight loss was measured by thermogravimetric measurement using a TGA 951 Thermogravimetric analyzer manufactured by DUPONT Co., Ltd. under a nitrogen stream of 40 ml / min at a heating rate of 20 ° C./min. The temperature at the time of decrease was obtained.

(Photoelastic constant)
The absolute value of the photoelastic constant of the polycarbonate resin of the present invention is 45 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 42 × 10 ⁻¹² Pa ⁻¹ or less, and further preferably 40 × 10 ⁻¹² Pa ⁻¹ or less. is there. When the absolute value exceeds 45 × 10 ⁻¹² Pa ⁻¹ , birefringence due to stress is large, and light leakage occurs when used for a retardation film or the like, which is not preferable. The photoelastic constant is measured using a spectroellipometer M-220 manufactured by JASCO Corporation for an unstretched film.

(Production method of polycarbonate resin)
The polycarbonate resin of the present invention is produced by a reaction means known per se for producing an ordinary polycarbonate resin, for example, a method of reacting a diol component with a carbonate precursor such as phosgene or carbonic acid diester. Next, basic means for these manufacturing methods will be briefly described.

In a reaction using, for example, phosgene as a carbonate precursor, the reaction is usually performed in the presence of an acid binder and a solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. In order to accelerate the reaction, a catalyst such as a tertiary amine or a quaternary ammonium salt can also be used. In that case, reaction temperature is 0-40 degreeC normally, and reaction time is several minutes-5 hours. In the polycarbonate resin of the present invention, monofunctional phenols that are usually used as a terminal terminator can be used in the polymerization reaction. Particularly in the case of a reaction using phosgene as a carbonate precursor, monofunctional phenols are generally used as a terminator for controlling the molecular weight, and the resulting aromatic polycarbonate resin has a terminal monofunctional phenol. Since it is blocked by a group based on, it is superior in thermal stability as compared to those not.
Such monofunctional phenols may be used as long as they are used as an end stopper for aromatic polycarbonate resins.

  The transesterification reaction using a carbonic acid diester as a carbonate precursor is performed by a method in which an aromatic dihydroxy component in a predetermined ratio is stirred with a carbonic acid diester while heating with an inert gas atmosphere to distill the generated alcohol or phenols. . The reaction temperature varies depending on the boiling point of the alcohol or phenol produced, but is usually in the range of 120 to 300 ° C. The reaction is completed while distilling off the alcohol or phenol produced under reduced pressure from the beginning. Moreover, you may add a terminal stopper, antioxidant, etc. as needed.

  Examples of the carbonic acid diester used in the transesterification include esters such as an aryl group having 6 to 12 carbon atoms and an aralkyl group which may be substituted. Specific examples include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate and m-cresyl carbonate. Of these, diphenyl carbonate is particularly preferred. The amount of diphenyl carbonate used is preferably 0.97 to 1.10 mol, more preferably 1.00 to 1.06 mol, per 1 mol of the total of dihydroxy compounds.

In the melt polymerization method, a polymerization catalyst can be used to increase the polymerization rate. Examples of the polymerization catalyst include alkali metal compounds, alkaline earth metal compounds, nitrogen-containing compounds, and metal compounds.
As such compounds, organic acid salts, inorganic salts, oxides, hydroxides, hydrides, alkoxides, quaternary ammonium hydroxides, and the like of alkali metals and alkaline earth metals are preferably used. It can be used alone or in combination.

  Specific examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, acetic acid. Cesium, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, phosphoric acid Dipotassium hydrogen, dilithium hydrogen phosphate, disodium phenyl phosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, sodium salt of phenol, potassium salt, cesium salt, lithium salt, etc. It is shown.

  Specific examples of the alkaline earth metal compound include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium diacetate, calcium diacetate, and diacetic acid. Examples include strontium and barium diacetate.

  Specific examples of the nitrogen-containing compound include quaternary ammonium having an alkyl or aryl group such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide. Hydroxides are exemplified. Further, tertiary amines such as triethylamine, dimethylbenzylamine and triphenylamine, and imidazoles such as 2-methylimidazole, 2-phenylimidazole and benzimidazole are exemplified. Moreover, bases or basic salts such as ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, tetraphenylammonium tetraphenylborate and the like are exemplified.

Examples of the metal compound include a zinc aluminum compound, a germanium compound, an organic tin compound, an antimony compound, a manganese compound, a titanium compound, and a zirconium compound. These compounds may be used alone or in combination of two or more.
The amount of these polymerization catalysts used is preferably 1 × 10 ⁻⁹ to 1 × 10 ⁻² equivalent, preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻⁵ equivalent, more preferably 1 × with ^respect to 1 mol of the diol component. It is selected in the range of 10 ⁻⁷ to 1 × 10 ⁻³ equivalents.

  In addition, a catalyst deactivator can be added at a later stage of the reaction. As the catalyst deactivator to be used, a known catalyst deactivator is effectively used, and among them, sulfonic acid ammonium salt and phosphonium salt are preferable. Furthermore, salts of dodecylbenzenesulfonic acid such as tetrabutylphosphonium salt of dodecylbenzenesulfonic acid and salts of paratoluenesulfonic acid such as tetrabutylammonium salt of paratoluenesulfonic acid are preferable.

  Specific examples of sulfonic acid esters include methyl benzenesulfonate, ethyl benzenesulfonate, butyl benzenesulfonate, octyl benzenesulfonate, phenyl benzenesulfonate, methyl paratoluenesulfonate, ethyl paratoluenesulfonate, and paratoluene. Examples include butyl sulfonate, octyl p-toluenesulfonate, phenyl p-toluenesulfonate, and the like. Among these, dodecylbenzenesulfonic acid tetrabutylphosphonium salt is particularly preferable.

  The amount of the catalyst deactivator used is preferably 0.5 to 50 mol per mol of the catalyst when at least one polymerization catalyst selected from alkali metal compounds and / or alkaline earth metal compounds is used. It can be used in a proportion, more preferably in a proportion of 0.5 to 10 mol, still more preferably in a proportion of 0.8 to 5 mol.

  In addition, heat stabilizers, plasticizers, light stabilizers, polymerized metal deactivators, flame retardants, lubricants, antistatic agents, surfactants, antibacterial agents, ultraviolet absorbers, release agents, etc. Additives can be blended.

<Optical molded product>
An optical molded article using the polycarbonate resin of the present invention is molded by any method such as an injection molding method, a compression molding method, an extrusion molding method, or a solution casting method. Since the polycarbonate resin of the present invention has a low photoelastic constant and can achieve desired wavelength dispersion by stretching, it can be advantageously used as an optical film. Of course, the polycarbonate resin of the present invention has a low photoelastic constant and excellent moldability, so that it can be used for optical disk substrates, optical lenses, liquid crystal panels, optical cards, sheets, optical fibers, connectors, vapor-deposited plastic reflectors, displays, etc. It can also be advantageously used as an optical molded article suitable for the structural material or functional material application of an optical component.

<Optical film>
Specifically, the optical film using the polycarbonate resin of the present invention may be used for a retardation film, a plastic substrate film, a polarizing plate protective film, an antireflection film, a brightness enhancement film, an optical disk protective film, a diffusion film, and the like. Among them, a retardation film, a polarizing plate protective film, and an antireflection film are preferable.
Examples of the method for producing the optical film include known methods such as a solution casting method, a melt extrusion method, a hot press method, and a calendar method. Of these, the solution casting method and the melt extrusion method are preferable, and the melt extrusion method is particularly preferable from the viewpoint of productivity.

  In the melt extrusion method, a method of feeding a resin to an extrusion cooling roll using a T die is preferably used. The melt extrusion temperature at this time is determined from the molecular weight, Tg, melt flow characteristics, etc. of the polycarbonate resin, but is in the range of 180 to 350 ° C, and more preferably in the range of 200 to 320 ° C. When the temperature is lower than 180 ° C., the viscosity is increased, and the orientation and stress strain of the polymer tend to remain, which is not preferable. On the other hand, when the temperature is higher than 350 ° C., problems such as thermal deterioration, coloring, and die line (stripe) from the T-die are likely to occur.

  Further, since the polycarbonate resin of the present invention has good solubility in an organic solvent, a solution casting method can also be applied. In the case of the solution casting method, methylene chloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, dioxolane, dioxane and the like are preferably used as the solvent. The amount of residual solvent in the film obtained by the solution casting method is preferably 2% by weight or less, more preferably 1% by weight or less. When the residual solvent amount exceeds 2% by weight, the glass transition temperature of the film is remarkably lowered, which is not preferable from the viewpoint of heat resistance.

  The thickness of the unstretched film using the polycarbonate of the present invention is preferably in the range of 30 to 400 μm, more preferably in the range of 40 to 300 μm. When the unstretched film is further stretched to obtain a retardation film, it is in the range of 20 to 200 μm, more preferably 20 to 150 μm, although it relates to the target retardation value. If it is this range, the desired phase difference value by extending | stretching will be easy to be obtained, and film forming is also easy and preferable. The unstretched film is suitably used as a polarizing plate protective film or a transmission layer film for optical disks.

  An unstretched film using the polycarbonate of the present invention becomes a retardation film by stretching and orientation. The machine axis direction in which the film is formed is referred to as the film forming direction or the longitudinal direction, and the direction perpendicular to the film forming direction and the film thickness direction is referred to as the lateral direction or the width direction. As the stretching method, a known method such as longitudinal uniaxial stretching, lateral uniaxial stretching using a tenter or the like, or simultaneous biaxial stretching or sequential biaxial stretching in combination thereof can be used. Moreover, although it is preferable from a point of productivity to perform continuously, you may carry out by a batch type. The stretching temperature is preferably in the range of (Tg-20 ° C) to (Tg + 50 ° C), more preferably in the range of (Tg-10 ° C) to (Tg + 30 ° C) with respect to the glass transition temperature (Tg) of the polycarbonate resin. is there. This temperature range is preferable because the molecular motion of the polymer is appropriate, relaxation due to stretching is unlikely to occur, orientation control is facilitated, and a desired in-plane retardation is easily obtained. If the stretching temperature is low, the phase difference tends to be easily developed.

Although the draw ratio is determined by the target retardation value, it is 1.05 to 5 times, more preferably 1.1 to 4 times in the vertical and horizontal directions, respectively. This stretching may be performed in a single stage or in multiple stages. In addition, said Tg in the case of extending | stretching the unstretched film obtained by the solution cast method means the glass transition temperature containing the trace amount solvent in this unstretched film.
The thickness of the film after stretching is preferably in the range of 20 to 200 μm, more preferably 20 to 150 μm. If it is this range, the desired phase difference value by extending | stretching will be easy to obtain, and film forming will be easy and preferable.

(Wavelength dispersion)
By stretching an unstretched film using the polycarbonate resin of the present invention, in the visible light region having a wavelength of 400 to 800 nm, the retardation in the film plane becomes smaller as the wavelength becomes shorter. That is, the following formula (1)
R (450) <R (550) <R (650) (1)
Meet. However, R (450), R (550), and R (650) represent retardation values in the film plane at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

Here, the in-plane retardation value R is defined by the following equation, and is a characteristic that expresses a phase delay between the X direction of light transmitted through the film in the vertical direction and the vertical Y direction.
_{R = (n x -n y)} × d
Where _nx is the refractive index in the main stretching direction in the film plane, _ny is the refractive index in the direction perpendicular to the main stretching direction in the film plane, and d is the thickness of the film. Here, the main stretching direction means a stretching direction in the case of uniaxial stretching, and a direction in which the degree of orientation is increased in the case of biaxial stretching. Refers to the orientation direction.

  The following film (I) to film (III) may be mentioned as preferred wavelength dispersion ranges of the optical film using the polycarbonate resin of the present invention.

(Film (I))
The film (I) is a film exhibiting so-called reverse wavelength dispersion satisfying the following formulas (2) and (3).
0 <R (450) / R (550) <1.00 (2)
1.01 <R (650) / R (550) <2.00 (3)
The film (I) more preferably satisfies the following formulas (2-1) and (3-1).
0.60 <R (450) / R (550) <1 (2-1)
1.01 <R (650) / R (550) <1.40 (3-1)
More preferably, the following formulas (2-2) and (3-2) are satisfied.
0.65 <R (450) / R (550) <0.92 (2-2)
1.01 <R (650) / R (550) <1.30 (3-2)
Particularly preferably, the following expressions (2-3) and (3-3) are satisfied.
0.70 <R (450) / R (550) <0.91 (2-3)
1.03 <R (650) / R (550) <1.20 (3-3)
The film (I) is an unstretched film formed by using the polycarbonate resin of the present invention, wherein the molar ratio (A / B) of the repeating unit (A) to the repeating unit (B) is 40/60 or more and less than 68/32. It is obtained by stretching the film. The molar ratio (A / B) of the repeating unit (A) to the repeating unit (B) is preferably 50/50 or more and less than 68/32, and more preferably 55/45 or more and less than 67/33.
The photoelastic constant of the polycarbonate resin of the present invention that satisfies the conditions of the film (I) is preferably 45 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 42 × 10 ⁻¹² Pa ⁻¹ or less, and particularly preferably. Is 40 × 10 ⁻¹² Pa ⁻¹ or less.
Since the film (I) exhibits reverse wavelength dispersion, a single film (I) is suitably used for a retardation film such as a liquid crystal display device without being laminated. In such applications, it is desirable that 100 nm <R (550) <180 nm for a λ / 4 plate and 220 nm <R (550) <330 nm for a λ / 2 plate.

(Film (II))
The film (II) is a film exhibiting so-called zero birefringence that satisfies the following formulas (4), (5), and (6).
−30 <R (450) <0 (4)
−10 <R (550) <10 (5)
0 <R (650) <30 (6)
The film (II) more preferably satisfies the following formulas (4-1), (5-1), and (6-1).
−30 <R (450) <0 (4-1)
−5 <R (550) <5 (5-1)
0 <R (650) <25 (6-1)
The film (II) is an unstretched film formed by using the polycarbonate resin of the present invention, wherein the molar ratio (A / B) of the repeating unit (A) to the repeating unit (B) is 68/32 or more and less than 75/25. It is obtained by stretching the film. The molar ratio (A / B) between the repeating unit (A) and the repeating unit (B) is preferably 68/32 or more and less than 74/26, more preferably 69/31 or more and less than 73/27.
Further, the photoelastic constant of the polycarbonate resin of the present invention that satisfies the condition of the film (II) is preferably 40 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 39 × 10 ⁻¹² Pa ⁻¹ or less, particularly preferably. Is 38 × 10 ⁻¹² Pa ⁻¹ or less.
Film (II) has low optical anisotropy. That is, the in-plane retardation value of the film is near zero at a wavelength of 400 to 800 nm. Therefore, it can be suitably used for a protective film for a polarizing plate of a liquid crystal display device.

(Film (III))
Film (III) is a film which shows the negative birefringence which satisfy | fills following formula (7).
R (650) <0 (7)
Film (III) is unstretched using the polycarbonate resin of the present invention produced at a molar ratio (A / B) of repeating unit (A) to repeating unit (B) in the range of 75/25 or more and less than 100/0. It is obtained by stretching the film. The molar ratio (A / B) between the repeating unit (A) and the repeating unit (B) is preferably 78/22 or more and less than 98/2, and more preferably 80/20 or more and 95/5 or less.
Further, the photoelastic constant of the polycarbonate resin of the present invention that satisfies the condition of the film (III) is preferably 35 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 33 × 10 ⁻¹² Pa ⁻¹ or less, particularly preferably. Is 30 × 10 ⁻¹² Pa ⁻¹ or less.
Since the film (III) has negative birefringence, the film (III) is suitable as a retardation film for an in-plane switching (IPS) mode liquid crystal display device.

  Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto. In the examples, “parts” means “parts by weight”. The resins used and the evaluation methods used in the examples are as follows.

1. Polymer composition ratio (NMR)
The polymer composition ratio (molar ratio) was calculated by proton NMR of JNM-AL400 manufactured by JEOL Ltd.

2. Specific Viscosity Measurement The viscosity was determined using an Ostwald viscometer from a solution of 0.7 g of polycarbonate resin in 100 ml of methylene chloride at 20 ° C.
Specific viscosity (η _SP ) = (t−t ₀ ) / t ₀
[T ₀ is methylene chloride falling seconds, t is sample solution falling seconds]

3. Glass transition temperature measurement Under a nitrogen atmosphere (nitrogen flow rate: 40 ml / min) according to JIS K7121, using a thermal analysis system DSC-2910 manufactured by TA Instruments Co., Ltd. using 8 mg of polycarbonate resin The temperature elevation rate was measured under the condition of 20 ° C./min.

4). Thermal decomposition temperature measurement Using a TGA 951 Thermogravimetric analyzer manufactured by DUPONT Co., Ltd. with a polycarbonate resin 8 mg, thermogravimetrically measured at a temperature increase rate of 20 ° C./min under a nitrogen flow of 40 ml / min, 5% The temperature when the weight decreased was determined.

5. Measurement of photoelastic constant An unstretched film was cut into a size of 50 mm in the film forming direction and 10 mm in the width direction perpendicular thereto, and the photoelastic constant was measured using the sample. Measurement was performed using Spectroellipometer M-220 manufactured by JASCO Corporation.

6). Measurement of retardation and wavelength dispersibility The stretched optical film was measured using Spectroellipometer M-220 manufactured by JASCO Corporation.

7). Evaluation of heat unevenness in a transmissive configuration A structure in which a polarizer film in which iodine is adsorbed and oriented in polyvinyl alcohol is sandwiched between two triacetylcellulose films, and an acrylic pressure-sensitive adhesive layer is provided on one side thereof A linear polarizing plate was prepared. The stretched film prepared in the example was subjected to corona discharge treatment under the condition of an integrated irradiation amount of 1500 J, and the corona discharge treatment surface was bonded to the linear polarizing plate at an angle of 45 ° to the acrylic pressure-sensitive adhesive layer side. Two polarizing plates were prepared and bonded to non-alkali glass (Corning Japan, trade name: EAGLE2000) through an adhesive as shown in FIG. Immediately after the configured circularly polarizing plate was stored at 85 ° C. for 30 minutes, the light leakage of the transmitted light when the backlight was applied was visually evaluated. If there was no light leakage, ○, and if there was a small amount of light leakage from the edge, Δ The case where light leakage was observed as a whole was rated as x. Light leakage occurs when stress is generated in the film adhered to the glass due to thermal expansion of the retardation film, and birefringence occurs due to the generated stress. Therefore, the higher the photoelastic constant, the greater the light leakage. Light leakage at room temperature before heating becomes less black as the reverse wavelength dispersion is better.

8). Evaluation of light leakage in the reflection type configuration A polarizing plate and alkali-free glass similar to those used for the thermal unevenness evaluation in the transmission type configuration were prepared and bonded together with an adhesive as shown in FIG. The reflection structure thus constructed was placed on a reflection plate, and when light was applied from above at room temperature, the reflected light did not escape and was black, the case of amber was Δ, and the case of blue was ×. The better the inverse wavelength dispersibility, the more black the light is not lost.

[Example 1]
<Manufacture of polycarbonate resin>
In a reactor equipped with a thermometer, a stirrer and a reflux condenser, 21540 parts of ion-exchanged water and 4930 parts of a 48% aqueous sodium hydroxide solution were placed, and 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene (hereinafter referred to as “9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene” After dissolving 5063 parts (sometimes abbreviated as “BSBF”), 1407 parts 2,2-bis (4-hydroxyphenyl) propane (hereinafter sometimes abbreviated as “BPA”) and 15 parts hydrosulfite, After adding 14530 parts of methylene chloride, 2200 parts of phosgene was blown in at a temperature of 15 to 25 ° C. with stirring for 60 minutes. After completion of phosgene blowing, 181.2 parts of p-tert-butylphenol and 705 parts of 48% aqueous sodium hydroxide solution were added, and after emulsification, 5.9 parts of triethylamine was added and stirred at 28 to 33 ° C. for 1 hour to complete the reaction. did. After completion of the reaction, the product was diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and when the conductivity of the aqueous phase became almost the same as that of ion-exchanged water, the methylene chloride was evaporated with a kneader, A white polymer was obtained. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the obtained polycarbonate resin were measured and listed in Table 1.

<Manufacture of optical film>
Next, a 15 mmφ twin-screw extruder manufactured by Technobel Co., Ltd. was attached with a T-die having a width of 150 mm and a lip width of 500 μm and a film take-up device, and the resulting polycarbonate resin was film-formed at 280 ° C., and transparent extrusion unstretched A film was obtained. A 50 mm × 10 mm size sample was cut out from the obtained unstretched film, and the photoelastic constant was measured using the sample. Further, an unstretched film of 100 mm length and 70 mm width cut out in the same manner was uniaxially stretched at 167 ° C. (Tg + 10 ° C.) in the length direction by 2.0 times to obtain a stretched film. The optical film was measured for retardation and wavelength dispersion. Furthermore, using this optical film, a circularly polarizing plate was prepared by the method 7 as shown in FIG. Moreover, the reflection structure of FIG. 2 was created by the method 8 using this optical film, and the light omission evaluation of the reflected light was performed. The results are shown in Table 1.

[Example 2]
<Manufacture of polycarbonate resin>
Except for using 5442 parts of 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene (hereinafter sometimes abbreviated as “BCHF”) and 1368 parts of BPA, the same operation as in Example 1 was carried out. A polycarbonate resin was obtained. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 1.

<Manufacture of optical film>
Next, the obtained polycarbonate resin was dissolved in methylene chloride to prepare a dope having a solid concentration of 19% by weight. The dope solution was poured onto a glass plate so as to have a thickness of 80 μm, peeled, and dried to prepare a cast film. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Further, in the same manner as in Example 1, evaluation of thermal unevenness and evaluation of light leakage of reflected light were performed. The results are shown in Table 1.

[Example 3]
<Manufacture of polycarbonate resin>
Except for using 5300 parts of 9,9-bis (4-hydroxy-3-tert-butylphenyl) fluorene (hereinafter sometimes abbreviated as “BTBF”) and 1290 parts of BPA, the same operation as in Example 1 was carried out. And a polycarbonate resin was obtained. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 1.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 2. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
<Manufacture of polycarbonate resin>
46.7 parts of BSBF, 1603 parts of BPA, 3741 parts of diphenyl carbonate, and 1.6 × 10 ⁻⁴ parts of sodium hydroxide as a catalyst were heated to 180 ° C. in a nitrogen atmosphere and melted. Thereafter, the degree of vacuum was adjusted to 13.4 kPa over 30 minutes. Thereafter, the temperature was raised to 280 ° C. at a rate of 20 ° C./hr and held at that temperature for 10 minutes, and then the degree of vacuum was set to 133 Pa or less over 1 hour. The reaction is carried out with stirring for a total of 6 hours. After the completion of the reaction, 4 times mole of the catalyst amount of tetrabutylphosphonium salt of dodecylbenzenesulfonate is added to deactivate the catalyst, and then discharged from the bottom of the reaction tank under nitrogen pressure. The pellet was obtained by cutting with a pelletizer while cooling in a water bath. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 1.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]
<Manufacture of polycarbonate resin>
The same operation as in Example 1 was carried out except that 5294 parts of BSBF and 2192 parts of α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene (hereinafter sometimes abbreviated as “BPM”) were used. A polycarbonate resin was obtained. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 1.

<Manufacture of optical film>
Next, the obtained polycarbonate resin was dissolved in methylene chloride to prepare a dope having a solid concentration of 19% by weight. A cast film was produced from this dope solution by a known method. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Further, in the same manner as in Example 1, evaluation of thermal unevenness and evaluation of light leakage of reflected light were performed. The results are shown in Table 1.

[Example 6]
<Manufacture of polycarbonate resin>
Except for using BTBF 5616 parts and BPA 1134 parts, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the obtained polycarbonate resin were measured and listed in Table 2.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 2. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 2.

[Example 7]
<Manufacture of polycarbonate resin>
Except that BSBF5616 parts, BPA1134 parts and diphenyl carbonate 3741 parts were used, the same operation as in Example 4 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the obtained polycarbonate resin were measured and listed in Table 2.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 2.

[Example 8]
<Manufacture of polycarbonate resin>
Except for using BSBF5853 parts, BPA1016 parts, and diphenyl carbonate 3741 parts, the same operation as in Example 4 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the obtained polycarbonate resin were measured and listed in Table 2.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 2.

[Example 9]
<Manufacture of polycarbonate resin>
Except for using BCHF5777 parts and BPA1211 parts, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 2.

<Manufacture of optical film>
Next, the obtained polycarbonate resin was dissolved in methylene chloride to prepare a dope having a solid concentration of 19% by weight. A cast film was produced from this dope solution by a known method. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Further, in the same manner as in Example 1, evaluation of thermal unevenness and evaluation of light leakage of reflected light were performed. The results are shown in Table 2.

[Example 10]
<Manufacture of polycarbonate resin>
Except for using BSBF 5616 parts and BPM 1720 parts, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 2.

<Manufacture of optical film>
Next, the obtained polycarbonate resin was dissolved in methylene chloride to prepare a dope having a solid concentration of 19% by weight. A cast film was produced from this dope solution by a known method. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Further, in the same manner as in Example 1, evaluation of thermal unevenness and evaluation of light leakage of reflected light were performed. The results are shown in Table 2.

[Example 11]
<Manufacture of polycarbonate resin>
Except for using BSBF7117 parts and BPA586 parts, the same operation as in Example 4 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 3.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 3.

[Example 12]
<Manufacture of polycarbonate resin>
Except for using BTBF 6802 parts and BPA 587 parts, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 3.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 2. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 3.

[Example 13]
<Manufacture of polycarbonate resin>
Except for using BCHF6530 parts and BPA860 parts, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 3.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 2. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 3.

[Example 14]
<Manufacture of polycarbonate resin>
Except for using 7436 parts of BSBF, 235 parts of BPA, and 3741 parts of diphenyl carbonate, the same operation as in Example 4 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the obtained polycarbonate resin were measured and listed in Table 3.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 3.

[Example 15]
<Manufacture of polycarbonate resin>
Except for using BSBF6723 parts and BPM888 parts, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 3.

<Manufacture of optical film>
Next, the obtained polycarbonate resin was dissolved in methylene chloride to prepare a dope having a solid concentration of 19% by weight. A cast film was produced from this dope solution by a known method. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Further, in the same manner as in Example 1, evaluation of thermal unevenness and evaluation of light leakage of reflected light were performed. The results are shown in Table 3.

[Comparative Example 1]
<Manufacture of polycarbonate resin>
To a reactor equipped with a thermometer, a stirrer, and a reflux condenser, 9809 parts of ion-exchanged water and 2271 parts of 48% sodium hydroxide aqueous solution were added to dissolve 1775 parts of BPA and 3.5 parts of sodium hydrosulfite, and 7925 parts of methylene chloride. Then, 1000 parts of phosgene was blown in at a temperature of 16 to 20 ° C. with stirring for 60 minutes. After completion of the phosgene blowing, 52.6 parts of p-tert-butylphenol and 327 parts of 48% aqueous sodium hydroxide solution were added, and 1.57 parts of triethylamine was further added, followed by stirring at 20 to 27 ° C. for 40 minutes to complete the reaction. . The methylene chloride layer containing the product was washed with dilute hydrochloric acid and pure water, and then methylene chloride was evaporated to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the powder were measured and listed in Table 1.

<Manufacture of optical film>
The obtained polycarbonate resin was pelletized with a 15 mmφ twin screw extruder. Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Further, in the same manner as in Example 1, evaluation of thermal unevenness and evaluation of light leakage of reflected light were performed. The results are shown in Table 1. This film has a high photoelastic constant of 80 × 10 ⁻¹² Pa ⁻¹ and a large birefringence due to stress. Therefore, light leakage occurs when used as a retardation film, which is not preferable. In addition, since the wavelength dispersion is positive dispersion, λ / 4 is not achieved in a wide band, and color loss is a problem.

[Comparative Example 2]
<Manufacture of polycarbonate resin>
Except for using 585 parts of BPA and 1969 parts of 9,9-bis (4-hydroxy-3-methylphenyl) fluorene BCF (hereinafter sometimes abbreviated as “BCF”), the same operation as in Comparative Example 1 was performed. A polycarbonate resin was obtained. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the powder were measured and listed in Table 1.

<Manufacture of optical film>
The obtained polycarbonate resin was dissolved in methylene chloride to prepare a dope having a solid concentration of 19% by weight. A cast film was produced from this dope solution by a known method. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Further, in the same manner as in Example 1, evaluation of thermal unevenness and evaluation of light leakage of reflected light were performed. The results are shown in Table 1.

[Comparative Example 3]
<Manufacture of polycarbonate resin>
Except for using 830 parts of BCF and 242 parts of tricyclo [5.2.1.0 ^2,6 ] decanedimethanol (hereinafter sometimes abbreviated as TCDDM), the same operation as in Example 4 was carried out to obtain a polycarbonate resin. Got. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 1.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 4]
<Manufacture of polycarbonate resin>
Except for using 156 parts of BCF, 356 parts of TCDDM, and 175 parts of isosorbide, the same operation as in Example 4 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 1.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 5]
<Manufacture of polycarbonate resin>
Except for using 461 parts of BPA and 2175 parts of BCF, the same operation as in Comparative Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the powder were measured and listed in Table 2.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Comparative Example 2. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Further, thermal unevenness evaluation was performed in the same manner as in Example 2. The results are shown in Table 2.

[Comparative Example 6]
<Manufacture of polycarbonate resin>
Except for using 610 parts of BCF and 356 parts of TCDDM, the same operation as in Example 4 was performed to obtain a polycarbonate resin. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the pellets were measured and listed in Table 2.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 1. The photoelastic constant of the obtained unstretched film was evaluated in the same manner as in Example 1. In the same manner as in Example 1, the film was uniaxially stretched by 2.0 times at Tg + 10 ° C., and phase difference measurement and wavelength dispersion were measured. Furthermore, the thermal unevenness evaluation was carried out in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 7]
<Manufacture of polycarbonate resin>
In a reactor equipped with a thermometer, a stirrer and a reflux condenser, 9809 parts of ion exchange water and 2271 parts of 48% sodium hydroxide aqueous solution are added, and 337 parts of BPA, 2280 parts of BCF and 4.5 parts of sodium hydrosulfite are dissolved, and chlorinated. After adding 6604 parts of methylene, 1000 parts of phosgene was blown in at 16 to 20 ° C. for 60 minutes while stirring. After completion of the phosgene blowing, 70 parts of p-tert-butylphenol and 327 parts of a 48% aqueous sodium hydroxide solution were added, 1.57 parts of triethylamine was further added, and the reaction was terminated by stirring at 20 to 27 ° C. for 40 minutes. The methylene chloride layer containing the product was washed with dilute hydrochloric acid and pure water, and then methylene chloride was evaporated to obtain a polycarbonate resin having a fluorene skeleton. The specific viscosity, glass transition temperature, and thermal decomposition temperature of the powder were measured and listed in Table 3.

<Manufacture of optical film>
Next, an unstretched film was prepared in the same manner as in Example 2. The photoelastic constant of the obtained new flame film was evaluated in the same manner as in Example 1. The film was uniaxially stretched 2.0 times at Tg + 10 ° C. in the same manner as in Example 1, and the retardation measurement and wavelength dispersion were measured. Further, the thermal unevenness evaluation was performed in the same manner as Example 1. The results are shown in Table 3.

[Comparative Example 8]
<Manufacture of polycarbonate resin>
Except for using 1037 parts of BCF and 135 parts of TCDDM, the same operation as in Example 4 was performed, but the melt viscosity was too high to obtain a high molecular weight product. The specific viscosity of the resin was measured and listed in Table 3.

In Table 1, BSBF is 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, BCHF is 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, and BTBF is 9,9- Bis (4-hydroxy-3-tert-butylphenyl) fluorene, BCF is 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, BPA is 2,2-bis (4-hydroxyphenyl) propane, BPM Represents α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, and TCDDM represents tricyclo [5.2.1.0 ^2,6 ] decanedimethanol, which is a diol component in the constituent monomer.

In Table 2, BSBF is 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, BCHF is 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, and BTBF is 9,9- Bis (4-hydroxy-3-tert-butylphenyl) fluorene, BCF is 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, BPA is 2,2-bis (4-hydroxyphenyl) propane, BPM Represents α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, and TCDDM represents tricyclo [5.2.1.0 ^2,6 ] decanedimethanol, which is a diol component in the constituent monomer.

In Table 3, BSBF is 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, BCHF is 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, and BTBF is 9,9- Bis (4-hydroxy-3-tert-butylphenyl) fluorene, BCF is 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, BPA is 2,2-bis (4-hydroxyphenyl) propane, BPM Represents α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, and TCDDM represents tricyclo [5.2.1.0 ^2,6 ] decanedimethanol, which is a diol component in the constituent monomer.

  The polycarbonate resin of the present invention is useful as an optical film for optical molded products, liquid crystal display devices, organic EL displays and the like.

1. Polarizing plate 2. Stretched film Inorganic glass Stretched film 5. Polarizing plate 6. a reflector

Claims (11)

The main repeating unit is the following formula

[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and R ₁ and R ₂ are bonded to each other. Thus, a carbocycle or a heterocycle may be formed. R ₄ and R ₅ may combine to form a carbocyclic or heterocyclic ring. m and n represent the same or different integers of 1 to 4. ]
The repeating unit (A) represented by the following formula

[In formula (B), R ₇ and R ₈ are each independently a hydrogen atom, a hydrocarbon group which may contain an aromatic group having 1 to 9 carbon atoms, or a halogen atom, and p and q are the same or different. An integer of 1 to 4 is shown. W is the following formula (W)

Where R ₉ and R ₁₀ are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a carbon atom. An aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aralkyl group having 7 to 17 carbon atoms is represented. R ₉ and R ₁₀ may combine to form a carbocyclic or heterocyclic ring.
R ₁₁ and R ₁₂ are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or 6 to 12 carbon atoms. Represents an aryl group. R ₁₃ is an alkylene group having 1 to 9 carbon atoms. a represents an integer of 0 to 20, and b represents an integer of 1 to 500. ]
In the range where the molar ratio (A / B) between the repeating unit (A) and the repeating unit (B) is 40/60 or more and less than 100/0, A polycarbonate resin having a specific viscosity of 0.20 to 1.50 measured with a methylene solution. The repeating unit (A) is represented by the following formula

[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and R ₁ and R ₂ are bonded to each other. Thus, a carbocycle or a heterocycle may be formed. R ₄ and R ₅ may combine to form a carbocyclic or heterocyclic ring. ]
The polycarbonate resin of Claim 1 which is a repeating unit (A1) represented by these. The repeating unit (A) is represented by the following formula

The polycarbonate resin according to claim 1, which is at least one selected from the group consisting of repeating units (A2), (A3), and (A4) represented by:   An unstretched film using the polycarbonate resin according to claim 1. The unstretched film according to claim 4 is stretched, and the following formula (1)
R (450) <R (550) <R (650) (1)
[However, R (450), R (550), and R (650) represent retardation values in the film plane at wavelengths of 450 nm, 550 nm, and 650 nm, respectively. ]
A stretched film that satisfies The following formulas (2) and (3)
0 <R (450) / R (550) <1.00 (2)
1.01 <R (650) / R (550) <2.00 (3)
The stretched film of Claim 5 which satisfy | fills. Following formula (4)-(6)
−30 <R (450) <0 (4)
−10 <R (550) <10 (5)
0 <R (650) <30 (6)
The stretched film of Claim 5 which satisfy | fills. Following formula (7)
R (650) <0 (7)
The stretched film of Claim 5 which satisfy | fills.   A circularly polarizing film comprising the stretched film according to claim 5 and a polarizing layer.   A liquid crystal display device comprising the stretched film according to claim 5.   A display element using the circularly polarizing film according to claim 9 as an antireflection film.

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