JP2017095605A - Optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin film optical film high in heat resistance, low in phase difference, good in flowability and less in gel.SOLUTION: There is provided an optical film which is formed from a polycarbonate resin having a repeating unit (A) represented by the formula (A) as a main repeating unit and relative viscosity measured in a methylene chloride solution at 20°C of 0.20 to 0.33 and a polycarbonate resin composition containing a phosphorous-based stabilizer and/or a hindered phenol-based stabilizer and has thickness of 10 to 50 μm. (A), where Rand Rare each independently H, a hydrocarbon group which may contain a C1 to C10 aromatic group or a halogen atom and m and n are each independently an integer of 0 to 4.SELECTED DRAWING: None

Description

  The present invention relates to an optical film having high heat resistance, low phase difference, good fluidity and less gel.

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 using the film which consists of PC-A for the board | substrate for transparent conductive films, heat resistance was not enough and it was difficult to use it.

  Therefore, various methods have been studied as countermeasures against the above problems. As one of them, it is proposed that a polycarbonate resin having high heat resistance can be obtained by reacting a carbonate precursor with bisphenol A and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (for example, Patent Document 1). 2), it is proposed to use a film made of the polycarbonate resin for a retardation film and a protective film for a polarizing plate (see, for example, Patent Documents 3, 4, 5, and 6). However, the polycarbonate resin has a high melt viscosity and is limited to film formation by the solution casting method. In addition, it has been proposed to form a polycarbonate resin composed of 9,9-bis (4-hydroxy-3-methylphenyl) fluorene and spiroglycol by a melt film forming method (Patent Document 7). However, a resin having a glass transition temperature of 150 ° C. or higher has a low thermal decomposition temperature, so that melt film formation is difficult, and decomposition occurs during film formation, causing bubbles and gels. Moreover, the strength of the film was low, and there was a problem in the bending characteristics. Further, a sheet (Patent Document 8) or 9,9-bis (4- (9)) formed by melting a polycarbonate resin obtained by copolymerizing 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, bisphenol A and a siloxane compound. A sheet in which a polycarbonate resin obtained by copolymerizing hydroxy-3-methylphenyl) fluorene and bisphenol A is formed into a melt has been proposed (Patent Document 9). However, the sheet thickness is large, there is no description about the retardation characteristics, it is not suitable as an optical film, and a thin film optical film with high heat resistance and low retardation is not known.

JP 2004-331688 A JP-A-8-134199 International Publication No. 2000/026705 Pamphlet International Publication No. 2001/009649 Pamphlet JP 2001-296423 A JP 2001-194530 A Japanese Patent No. 5119250 JP 2011-89050 A JP-A-6-25399

  An object of the present invention is to provide a thin film optical film having high heat resistance, low retardation, good fluidity and less gel.

As a result of extensive research, the present inventors have formed a very thin film with a composition containing a specific heat stabilizer and a carbonate precursor in a specific composition ratio in a bisphenol compound having a fluorene structure and an aromatic diol. Thus, it was found that the retardation can be reduced, and that a film having high heat resistance, low retardation, good fluidity and less gel can be obtained.
That is, the present invention is as follows.

［式（Ａ）中、Ｒ_１およびＲ_２は夫々独立して、水素原子、炭素原子数１〜１０の芳香族基を含んでもよい炭化水素基またはハロゲン原子を示し、ｍおよびｎは夫々独立して０〜４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_３、Ｒ_４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_５とＲ_６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_５とＲ_６が結合して炭素環または複素環を形成しても良い。Ｒ_７とＲ_８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_９は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、繰り返し単位（Ａ）と繰り返し単位（Ｂ）とのモル比（Ａ／Ｂ）が５／９５以上４０／６０以下の範囲で、２０℃の塩化メチレン溶液で測定された比粘度が０．２０〜０．３３であるポリカーボネート樹脂とリン系安定剤および／またはヒンダードフェノール系安定剤を含むポリカーボネート樹脂組成物から形成される厚み１０〜５０μｍの光学フィルム。
２．ポリカーボネート樹脂のガラス転移温度が１５０〜１９０℃である前項１記載の光学フィルム。
３．波長５５０ｎｍにおける面内位相差値Ｒｅの絶対値が２０ｎｍ以下であり、厚み方向位相差値Ｒｔｈの絶対値が５０ｎｍ以下である前項１記載の光学フィルム。
４．ゲル数が１００個／ｍ^２以下である前項１記載の光学フィルム。
５．ポリカーボネート樹脂の熱による５％重量減少の温度が４８５℃以上である前項１記載の光学フィルム。
６．ポリカーボネート樹脂１００重量部に対して、リン系安定剤および／またはヒンダードフェノール系安定剤０．００１〜１重量部含む前項１記載の光学フィルム。
７．ポリカーボネート樹脂組成物から溶融押出法により光学フィルムを製造する方法であって、溶融押出法により成形する際の樹脂温度が２４０℃以上３３０℃以下である前項１記載の光学フィルムの製造方法。
８．真空度１０ｋＰａ以下で供給したポリカーボネート樹脂組成物ペレットを溶融押出法により成形する前項７記載の光学フィルムの製造方法。
９．前項１記載の光学フィルムを用いて形成させたディスプレイ用基板またはタッチパネル用基板。 1. The main repeating unit is the following formula

[In Formula (A), R ₁ and R ₂ each independently represent a hydrogen atom, a hydrocarbon group that may contain an aromatic group having 1 to 10 carbon atoms, or a halogen atom, and m and n each independently And represents an integer of 0 to 4. ]
The repeating unit (A) represented by the following formula

[In Formula (B), R ₃ and R ₄ are each independently a hydrogen atom, a hydrocarbon group that 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 ₅ and R ₆ are 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, and a carbon atom, respectively. 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 ₅ and R ₆ may combine to form a carbocyclic or heterocyclic ring. R ₇ and R ₈ 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 ₉ 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. ]
Methylene chloride at 20 ° C. with a molar ratio (A / B) of the repeating unit (A) to the repeating unit (B) of 5/95 or more and 40/60 or less. An optical film having a thickness of 10 to 50 μm formed from a polycarbonate resin composition containing a polycarbonate resin having a specific viscosity of 0.20 to 0.33 measured in a solution and a phosphorus stabilizer and / or a hindered phenol stabilizer .
2. 2. The optical film as described in 1 above, wherein the polycarbonate resin has a glass transition temperature of 150 to 190 ° C.
3. 2. The optical film as described in 1 above, wherein the absolute value of the in-plane retardation value Re at a wavelength of 550 nm is 20 nm or less and the absolute value of the thickness direction retardation value Rth is 50 nm or less.
4). ^2. The optical film as described in 1 above, wherein the number of gels is 100 / m ² or less.
5. 2. The optical film as described in 1 above, wherein the temperature of 5% weight loss due to heat of the polycarbonate resin is 485 ° C. or higher.
6). 2. The optical film as described in 1 above, comprising 0.001 to 1 part by weight of a phosphorus stabilizer and / or a hindered phenol stabilizer relative to 100 parts by weight of the polycarbonate resin.
7). 2. The method for producing an optical film according to item 1, wherein the optical film is produced from the polycarbonate resin composition by a melt extrusion method, and the resin temperature at the time of molding by the melt extrusion method is 240 ° C. or more and 330 ° C. or less.
8). 8. The method for producing an optical film as described in 7 above, wherein the polycarbonate resin composition pellets supplied at a vacuum degree of 10 kPa or less are molded by a melt extrusion method.
9. A display substrate or a touch panel substrate formed using the optical film according to the preceding item 1.

  The present invention comprises a reaction of a carbonate precursor with a specific composition ratio to a bisphenol compound having a fluorene structure and an aromatic diol, and a specific heat stabilizer, thereby providing high heat resistance and low phase difference. It became possible to make an optical film with good fluidity, less gel, and excellent transparency. Therefore, the industrial effect that it produces is exceptional.

Hereinafter, the present invention will be described in detail.
<Polycarbonate resin>
As for the polycarbonate resin used by this invention, the main repeating unit is comprised from a repeating unit (A) and a repeating unit (B).

(Repeating unit (A))
The repeating unit (A) is represented by the formula (A), and R ₁ and R ₂ are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, or a halogen group. (Fluorine atom, chlorine atom, bromine atom, etc.) are preferred. More preferably, they are a hydrogen atom, a C1-C6 alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, or a halogen group (a fluorine atom, a chlorine atom, a bromine atom, etc.).

  Specifically, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-ethylphenyl) Fluorene, 9,9-bis (4-hydroxy-3-n-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-isopropylphenyl) fluorene, 9,9-bis (4-hydroxy-3- n-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-tart-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-cyclohexylphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene It is a carbonate unit derived from. In particular, carbonate units derived from 9,9-bis (4-hydroxy-3-methylphenyl) fluorene are preferred.

(Repeating unit (B))
The repeating unit (B) is a carbonate unit having an aromatic structure as shown in the formula (B). In the formula (B), R ₃ and R ₄ 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. One type selected from 7 to 13 aralkyl groups and halogen atoms is preferred. R ₃ and R ₄ are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 9 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an aralkyl group having 7 to 9 carbon atoms, and a halogen atom. One type selected from atoms is more preferable, and a hydrogen atom, a methyl group, a cyclohexyl group, or a phenyl group is more preferable. p and q represent the number of R ₃ and R ₄ substituted on the benzene ring, and are integers of 1 to 4.

W is represented by the above formula (W), and R ₅ and R ₆ in the formula (W) are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or an alkyl group having 1 to 9 carbon atoms. Represents an alkoxy group having 1 to 5 carbon atoms, 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. R ₅ and R ₆ may combine to form a carbocyclic or heterocyclic ring.
R ₇ and R ₈ 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 ₉ 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)
As for the composition ratio of the polycarbonate resin used in the present invention, the molar ratio (A / B) of the main repeating unit (A) to the repeating unit (B) is 5/95 or more and 40/60 or less. When the polycarbonate resin of the present invention having a molar ratio (A / B) in the range of 5/95 to 40/60 is formed into a film, the fluidity is excellent, the heat resistance of the film is good, the number of gels is small, and birefringence is achieved. Is preferable because it is low and suitable for optical applications. The molar ratio (A / B) is preferably from 7/93 to 38/62, more preferably from 9/91 to 36/64, and still more preferably from 10/90 to 34/66. The inclusion of the repeating unit (B) is preferable from the viewpoint of fluidity control. The molar ratio (A / B) is measured and calculated by proton NMR of JNM-AL400 manufactured by JEOL. The main repeating unit means that the total of the repeating unit (A) and the repeating unit (B) is 60 mol% or more, preferably 70 mol% or more, more preferably 80 mol%, and still more preferably based on all repeating units. More than 90 mol%, and particularly preferably substantially consists of a repeating unit (A) and a repeating unit (B).

(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 0.33. When it is 0.20 or more, strength and the like are improved, and when it is 0.33 or less, flow characteristics are excellent. Preferably it is the range of 0.24-0.33, More preferably, it is the range of 0.27-0.33, Most preferably, it is the range of 0.30-0.33. 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 used in the present invention is preferably in the range of 150 to 190 ° C, more preferably 152 to 185 ° C, and particularly preferably 154 to 180 ° C. When Tg is equal to or higher than the lower limit, the heat resistance stability is improved, and deformation of the film in the film processing step can be suppressed. Moreover, in the range where Tg does not exceed the upper limit, a high temperature is not necessary for film forming processing, and it is preferable because special processing equipment different from the conventional one is not required. 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.

<Temperature of 5% weight loss due to heat of polycarbonate resin>
The polycarbonate resin used for the optical film of the present invention has a temperature of 5% weight loss due to heat, preferably 485 ° C. or higher, more preferably 490 ° C. or higher. When the temperature is lower than 485 ° C., decomposition is likely to occur during melt film formation, and foreign matter may be generated to affect display quality. This temperature 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 rate of temperature increase of 20 ° C./min. Asked.

(Production method of polycarbonate resin)
The polycarbonate resin used in 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.

<Heat stabilizer>
The polycarbonate resin contains a specific heat stabilizer in order to suppress a decrease in molecular weight and a deterioration in hue during extrusion / molding. The heat stabilizer contains a phosphorus stabilizer and / or a hindered phenol stabilizer. The phosphorus stabilizer is preferably at least one selected from a phosphite compound, a phosphate compound, a phosphonite compound, and a phosphonate compound.

  Examples of the phosphite compound include triphenyl phosphite, trisnonylphenyl 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, distearyl pentaerythritol diphosphite, bis (2,6 -Di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octylphospha , Bis (nonylphenyl) pentaerythritol diphosphite, and bis (2,4-di -tert- butylphenyl) pentaerythritol diphosphite and the like. Among these, tris (2,4-di-tert-butylphenyl) phosphite and bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite are preferable.

  Examples of the phosphate compound include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorthoxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, Examples thereof include diisopropyl phosphate, and triphenyl phosphate and trimethyl phosphate are preferable.

  Examples of the phosphonite compound include tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3′-biphenylenedi. Phosphonite, tetrakis (2,4-di-tert-butylphenyl) -3,3′-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite Tetrakis (2,6-di-tert-butylphenyl) -4,3′-biphenylene diphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3′-biphenylene diphosphonite, bis (2,4-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, bis (2,4-di tert-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-n-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl)- 4-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl) -3-phenyl-phenylphosphonite, and the like, and tetrakis (di-tert-butylphenyl) -biphenylenediphosphonite, bis (Di-tert-butylphenyl) -phenyl-phenylphosphonite is preferred, tetrakis (2,4-di-tert-butylphenyl) -biphenylenediphosphonite, bis (2,4-di-tert-butylphenyl)- More preferred is phenyl-phenylphosphonite. Such a phosphonite compound is preferable because it can be used in combination with a phosphite compound having an aryl group in which two or more alkyl groups are substituted.

Examples of the phosphonate compound include dimethyl benzenephosphonate, diethyl benzenephosphonate, and dipropyl benzenephosphonate.
Said phosphorus stabilizer can be used individually or in combination of 2 or more types, Preferably it is 0.001-1 weight part per 100 weight part of polycarbonate resin, More preferably, it is 0.01-0. 5 parts by weight, more preferably 0.05 to 0.3 parts by weight is blended.

  The hindered phenol stabilizer is not particularly limited as long as it has an antioxidant function. For example, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butyl) Phenyl) propionate, tetrakis {methylene-3- (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionate} methane, distearyl (4-hydroxy-3-methyl-5-tert-butylbenzyl) Malonate, triethylene glycol-bis {3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate}, 1,6-hexanediol-bis {3- (3,5-di-t-butyl) -4-hydroxyphenyl) propionate}, pentaerythrityl-tetrakis {3- (3,5-di-t-butyl-4-hydroxy) Enyl) propionate}, 2,2-thiodiethylenebis {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate}, 2,2-thiobis (4-methyl-6-tert-butylphenol) 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl-4-hydroxybenzyl) ) -Isocyanurate, 2,4-bis {(octylthio) methyl} -o-cresol, isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,5,7,8 Tetramethyl-2 (4 ′, 8 ′, 12′-trimethyltridecyl) chroman-6-ol, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-t-butyl-a, a ', A - (mesitylene-2,4,6-triyl) tri -p- cresol.

Among these, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, pentaerythrityl-tetrakis {3- (3,5-di-t-butyl) -4-hydroxyphenyl) propionate}, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-t-butyl-a, a ′, a ′-(mesitylene-2,4,6-triyl) Tri-p-cresol, 2,2-thiodiethylenebis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate} and the like are preferable.
These hindered phenol-based stabilizers may be used alone or in combination of two or more.

The hindered phenol stabilizer is preferably 0.001 to 1 part by weight, more preferably 0.01 to 0.5 part by weight, still more preferably 0.05 to 0.3 part by weight per 100 parts by weight of the polycarbonate resin. Is done.
Further, the phosphorus stabilizer and the hindered phenol stabilizer may be used in combination, and the combined amount of the phosphorus stabilizer and the hindered phenol stabilizer when used in combination is 100 parts by weight of the polycarbonate resin. Preferably it is 0.001-1 weight part, More preferably, it is 0.01-0.5 weight part, More preferably, 0.05-0.3 weight part is mix | blended.

<Optical film>
Specifically, the optical film of the present invention includes applications such as 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, etc. A phase difference film, a polarizing plate protective film and an antireflection film are preferred.
As a method for producing an optical film, a melt extrusion method is adopted from the viewpoint of productivity.

In the melt extrusion method, a method of feeding the polycarbonate resin composition to an extrusion cooling roll using a T die is preferably used. The melt extrusion resin temperature at this time is determined from the molecular weight, Tg, melt flow characteristics, etc. of the polycarbonate resin, but is preferably in the range of 240 to 330 ° C, more preferably in the range of 250 ° C to 320 ° C. When the temperature is lower than 240 ° C., the viscosity becomes high and polymer orientation and stress strain tend to remain, and when the temperature is higher than 330 ° C., problems such as gelation due to thermal deterioration, coloring, and die line (stripe) from the T-die are likely to occur. Further, it is preferable to use a vacuum hopper that can be kept in a reduced pressure state. The degree of vacuum is preferably 10 kPa or less, more preferably 5 kPa or less, and particularly preferably 3 kPa or less.
As a thickness of an optical film, it is the range of 10-50 micrometers, Preferably it is 10-40 micrometers, More preferably, it is the range of 15-30 micrometers. Such an optical film is suitably used as a display substrate or a touch panel substrate.

In the optical film of the present invention, the absolute value of the in-plane retardation value Re at a wavelength of 550 nm is preferably 20 nm or less, more preferably 15 nm or less, particularly preferably 10 nm or less, and 5 nm or less. More preferably. Further, the absolute value of the thickness direction retardation value Rth at a wavelength of 550 nm is preferably 50 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, and further preferably 6 nm or less. Within the above range, when used as a display substrate or a touch panel substrate, the image on the display or the touch panel is not blurred and a high-definition image can be displayed.
The haze of the optical film of the present invention is preferably 0 to 3%, more preferably 0 to 2%, further preferably 0 to 1%, and particularly preferably 0 to 0.5%. When the haze is within the above range, the image visibility is excellent and preferable.

  An unstretched optical film is preferably employed as the optical film of the present invention. However, the phase difference of the unstretched optical film may be adjusted 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.

It is preferable that the gel of the optical film obtained is 100 / m ² or less, more preferably 50 pieces / m ² or less. When the number of gels is within the above range, the display or touch panel can display a high-definition image when used as a display substrate or a touch panel substrate.

  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. Measurement of glass transition temperature (Tg) Using a thermal analysis system DSC-2910 manufactured by TA Instruments Co., Ltd. using 8 mg of polycarbonate resin, in a nitrogen atmosphere (nitrogen flow rate: 40 ml) according to JIS K7121 / Min), temperature increase rate: measured at 20 ° C./min.

4). Temperature (Td) measurement of 5% weight loss due to heat Using a TGA 951 Thermogravimetric analyzer manufactured by DUPONT Co., Ltd., thermogravimetrically measured at a rate of temperature increase of 20 ° C./min in a nitrogen stream of 40 ml / min. The temperature when the% weight decreased was determined.

5. Haze
Using the obtained film, a turbidimeter NDH-2000 type (manufactured by Nippon Denshoku Industries Co., Ltd.) was used, and the haze of the film was measured according to JIS K7105.

6). Number of gels The obtained film was obtained by converting the number of gels having interference fringes having a major axis diameter of 300 μm or more present in 500 mm × 1000 mm into a film 1 m ² using a color 3D laser microscope.

7). Phase difference measurement (Re, Rth)
The obtained optical film was measured using a Spectroellipsometer M-220 manufactured by JASCO Corporation.

[Example 1]
<Manufacture of polycarbonate resin>
A reactor equipped with a thermometer, a stirrer, and a reflux condenser was charged with 21540 parts of ion-exchanged water and 4930 parts of a 48% aqueous sodium hydroxide solution, and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (hereinafter “BCF”). 970 parts), 2,2-bis (4-hydroxyphenyl) propane (hereinafter sometimes abbreviated as "BPA") 3321 parts, hydrosulfite 15 parts, and methylene chloride After adding 14530 parts, 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, 104.8 parts of p-tert-butylphenol and 705 parts of 48% aqueous sodium hydroxide solution were added. 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 is diluted with methylene chloride, washed with water, acidified with hydrochloric acid and washed with water. When the conductivity of the aqueous phase becomes almost the same as that of ion-exchanged water, the methylene chloride is evaporated in a kneader. A white polymer was obtained. To the obtained polycarbonate resin, IRGAFOS 168 (manufactured by BASF, chemical name Tris (2,4-di-tert-butylphenyl) phosphite) was added in an amount of 0.1 parts by weight (based on 100 parts by weight of the polycarbonate resin), and vented. A melt-extruded pellet was obtained with a twin screw extruder (manufactured by Nippon Steel Works, Ltd .: TEX120α). The specific viscosity, Tg, and Td of the obtained polycarbonate resin were measured and listed in Table 1.

<Manufacture of optical film>
Next, a vacuum hopper whose degree of vacuum was adjusted to 1 kPa or less and a T-die having a width of 650 mm were attached to a single screw extruder of 40 mmφ, and the obtained polycarbonate resin was formed into a film at 305 ° C. to form a transparent 25 μm thick film. An extruded unstretched film was obtained. The retardation of the obtained optical film, the number of gels, and Haze were measured.

[Example 2]
<Manufacture of polycarbonate resin>
Except for using 1294 parts of BCF and 3126 parts of BPA, the same operation as in Example 1 was performed to obtain a polycarbonate resin. Adeka Stub PEP36 (manufactured by Adeka Corporation, chemical name bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite) 0.05 parts by weight (polycarbonate resin 100) was added to the obtained polycarbonate resin. Irganox 1010 (manufactured by BASF, chemical name pentaerythrityl-tetrakis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}) 0.05 parts by weight (polycarbonate resin 100) And the same operation as in Example 1 was performed to obtain pellets. The specific viscosity, Tg, and Td of the pellets were measured and listed in Table 1.
<Manufacture of optical film>
Next, a film was formed from the obtained polycarbonate resin in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Example 3]
<Manufacture of polycarbonate resin>
Except for using BCF1941 parts and BPA2735 parts, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, Tg, and Td of the pellets were measured and listed in Table 1.
<Manufacture of optical film>
Next, a film was formed from the obtained polycarbonate resin in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Example 4]
<Manufacture of optical film>
Using the polycarbonate resin obtained in Example 3, a film having a thickness of 15 μm was formed in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Example 5]
<Manufacture of optical film>
Using the polycarbonate resin obtained in Example 3, a film having a thickness of 40 μm was formed in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Example 6]
<Manufacture of polycarbonate resin>
Except for using 119.5 parts of p-tert-butylphenol, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, Tg, and Td of the pellets were measured and listed in Table 1.
<Manufacture of optical film>
Next, a film was formed from the obtained polycarbonate resin in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Example 7]
<Manufacture of polycarbonate resin>
Except for using 134.5 parts of p-tert-butylphenol, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, Tg, and Td of the pellets were measured and listed in Table 1.
<Manufacture of optical film>
Next, a film was formed from the obtained polycarbonate resin in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Example 8]
<Manufacture of polycarbonate resin>
Except for using 2200 parts of BCF and 2579 parts of BPA, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, Tg, and Td of the pellets were measured and listed in Table 1.
<Manufacture of optical film>
Next, a film was formed from the obtained polycarbonate resin in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Example 9]
<Manufacture of polycarbonate resin>
Except for using 599 parts of bisphenolfluorene (hereinafter sometimes abbreviated as “BPFL”) and 3516 parts of BPA, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, Tg, and Td of the pellets were measured and listed in Table 1.
<Manufacture of optical film>
Next, a film was formed from the obtained polycarbonate resin in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Comparative Example 1]
<Manufacture of optical film>
Using the polycarbonate resin obtained in Example 3, a film having a thickness of 100 μm was formed in the same manner as in Example 1 except that a vacuum hopper was not used, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Comparative Example 2]
<Manufacture of polycarbonate resin>
Except for using the polycarbonate resin obtained in Example 3, the same operation as in Example 1 was performed to obtain a polycarbonate resin. Without adding IRGAFOS 168 (manufactured by BASF) to the obtained polycarbonate resin, the same operation as in Example 1 was performed to obtain pellets. The specific viscosity, Tg, and Td of the pellets were measured and listed in Table 1.
<Manufacture of optical film>
Next, a film was formed from the obtained polycarbonate resin in the same manner as in Example 1, and the phase difference, the number of gels, and Haze were measured. The results are shown in Table 1.

[Comparative Example 3]
<Manufacture of polycarbonate resin>
Except for using 970 parts of BCF, 3321 parts of BPA, and 98.8 parts of p-tert-butylphenol, the same operation as in Example 1 was performed to obtain a polycarbonate resin. The specific viscosity, Tg, and Td of the pellets were measured and listed in Table 1.
<Manufacture of optical film>
Next, the obtained polycarbonate resin was formed into a film having a thickness of 100 μm by the same operation as in Example 1, and the retardation, the number of gels, and Haze were measured. The results are shown in Table 1.

[Comparative Example 4]
<Manufacture of optical film>
Using the polycarbonate resin obtained in Example 3, it was dissolved in methylene chloride to prepare a dope having a solid concentration of 19% by weight. A cast film (thickness: 100 μm) was prepared from this dope solution by a known method, and the retardation, the number of gels, and the haze were measured. The results are shown in Table 1.

  The optical film of the present invention is useful as an optical film such as a display substrate or a touch panel substrate.

Claims (9)

The main repeating unit is the following formula

[In Formula (A), R ₁ and R ₂ each independently represent a hydrogen atom, a hydrocarbon group that may contain an aromatic group having 1 to 10 carbon atoms, or a halogen atom, and m and n each independently And represents an integer of 0 to 4. ]
The repeating unit (A) represented by the following formula

[In Formula (B), R ₃ and R ₄ are each independently a hydrogen atom, a hydrocarbon group that 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 ₅ and R ₆ are 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, and a carbon atom, respectively. 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 ₅ and R ₆ may combine to form a carbocyclic or heterocyclic ring. R ₇ and R ₈ 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 ₉ 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. ]
Methylene chloride at 20 ° C. with a molar ratio (A / B) of the repeating unit (A) to the repeating unit (B) of 5/95 or more and 40/60 or less. An optical film having a thickness of 10 to 50 μm formed from a polycarbonate resin composition containing a polycarbonate resin having a specific viscosity of 0.20 to 0.33 measured in a solution and a phosphorus stabilizer and / or a hindered phenol stabilizer .   The optical film according to claim 1, wherein the polycarbonate resin has a glass transition temperature of 150 to 190 ° C.   The optical film according to claim 1, wherein the absolute value of the in-plane retardation value Re at a wavelength of 550 nm is 20 nm or less, and the absolute value of the thickness direction retardation value Rth is 50 nm or less. The optical film according to claim 1, wherein the number of gels is 100 / m ² or less.   The optical film according to claim 1, wherein the temperature of 5% weight loss due to heat of the polycarbonate resin is 485 ° C. or more.   The optical film according to claim 1, comprising 0.001 to 1 part by weight of a phosphorus-based stabilizer and / or a hindered phenol-based stabilizer with respect to 100 parts by weight of the polycarbonate resin.   2. The method for producing an optical film according to claim 1, wherein the optical film is produced from the polycarbonate resin composition by a melt extrusion method, and the resin temperature at the time of molding by the melt extrusion method is 240 ° C. or more and 330 ° C. or less.   The manufacturing method of the optical film of Claim 7 which shape | molds the polycarbonate resin composition pellet supplied with the vacuum degree of 10 kPa or less by a melt extrusion method.   A display substrate or a touch panel substrate formed using the optical film according to claim 1.