JP5598409B2 - Urethane urea resin composition, optical film, and method for producing optical film - Google Patents

Description

  The present invention relates to a urethane urea resin composition excellent in optical performance, an optical film, and a method for producing an optical film.

  A liquid crystal display (LCD) with a liquid crystal display device is widely used as a display device for personal computer monitors, TV monitors, mobile phones, small amusement devices, etc. because it has features such as thinness, light weight, and low power consumption. Has been.

  In recent years, with the growing demand for mobile phones and liquid crystal televisions in particular, optical films such as viewing angle compensation films, polarizing plate protective films, retardation films, antireflection films, and antiglare films, which are constituent members thereof, have become very popular. It is becoming useful.

  The characteristics required for the optical film vary depending on the application. In particular, in a liquid crystal television, a wide viewing angle is strongly demanded with an increase in screen size.

  Conventionally, a triacetyl cellulose (TAC) film has been widely used as the optical film. However, since the TAC film has poor optical compensation function that can contribute to wide viewing angle, a method of adding an aromatic compound as a retardation increasing agent to the TAC film (see, for example, Patent Document 1). Alternatively, a method of adding an ester compound composed of a mixture of a diester compound having an aromatic group at both ends and a polyester compound having an aromatic cyclic structure at both ends and in the molecular chain (see, for example, Patent Document 2). Etc. have been proposed.

  Thus, in recent years, polycarbonate (PC) films and cycloolefin polymer (COP) films have attracted attention as alternatives to TAC films that lack optical compensation function.

  The optical compensation film is usually subjected to processing such as uniaxial or biaxial stretching to express the optical compensation function by orienting the molecules, but the PC film is excellent in durability such as heat resistance and heat and humidity resistance, Since the film is too tough and difficult to stretch, and it is difficult to orient the molecules, there is a problem that it is difficult to develop an optical compensation function. Further, if the stretching temperature (hereinafter referred to as stretching temperature) when stretching the film is high, the orientation of the molecules is disturbed, so it is very difficult to control the optical compensation function.

  Further, the COP film is excellent in both durability and optical compensation function, but is expensive, and therefore, there is a strong demand for thin film from the viewpoint of cost reduction. However, since the optical compensation function is lowered by reducing the thickness of the COP film, improvement is required.

  As described above, although there is a strong demand from the industry for an optical film and a material thereof that can stretch the film even under a low stretching temperature and have excellent optical compensation function and durability even in a thin film, The current situation is that it has not been issued.

JP 2000-284124 A JP 2008-069225 A

  The problem to be solved by the present invention is that a resin composition that can stretch a film even under conditions of a low stretching temperature and that can provide an optical film excellent in optical compensation function and durability even in a thin film, and an optical system using the same It is providing the manufacturing method of a film and an optical film.

  The inventors of the present invention have made extensive studies while paying attention to the use of a urethane resin while advancing studies to solve the above problems. Specifically, combinations of various types of polyols and polyisocyanates were examined, and further, combinations with various types of chain extenders were also examined.

  As a result, urethane obtained by reacting a polyol containing an aliphatic cyclic structure-containing polycarbonate polyol and an aromatic polyester polyol, an aliphatic cyclic structure-containing polyisocyanate, and an aliphatic cyclic structure-containing polyamine. When a urethane urea resin composition containing a urea resin and a solvent is used, the film can be stretched even under conditions of low stretching temperature, and an optical film excellent in optical compensation function and durability can be obtained even in a thin film. The headline and the present invention were completed.

That is, the present invention relates to a polyol (A) containing an aliphatic cyclic structure-containing polycarbonate polyol (A-1) and an aromatic polyester polyol (A-2), and an aliphatic cyclic structure-containing polyisocyanate (B). And a urethane urea resin composition (1) obtained by reacting an aliphatic cyclic structure-containing polyamine (C) and a solvent (2), and an optical film obtained using the same It is about.
The present invention also relates to a polyol (A) containing an aliphatic cyclic structure-containing polycarbonate polyol (A-1) and an aromatic polyester polyol (A-2), and an aliphatic cyclic structure-containing polyisocyanate (B). A urethane urea resin composition containing a urethane urea resin (1) and a solvent (2) obtained by reacting an aliphatic cyclic structure-containing polyamine (C), and then applying The present invention relates to a method for producing an optical film, which comprises a step (i) of obtaining a film by drying a substrate and a step (ii) of stretching the film.

According to the present invention, by using the urethane urea resin composition, the stretching temperature is lowered and the molecular orientation is hardly disturbed, which can contribute to the improvement of the optical compensation function.
Moreover, the optical film obtained by using the urethane urea resin composition of the present invention is excellent in optical compensation function and durability even in a thin film.
Moreover, according to the manufacturing method of this invention, the optical film excellent in an optical compensation function can be manufactured simply.

  The optical compensation function in the present invention compensates for a phase difference caused by a liquid crystal substance constituting a liquid crystal display device, and plays an important role in realizing a wide viewing angle. If the phase difference is not compensated, there is a problem that the color and shape of an image displayed when the liquid crystal screen is viewed from an oblique direction looks different from the original one. Therefore, the optical compensation function refers to optical anisotropy for developing a wide viewing angle.

  First, the urethane urea resin (1) used in the present invention will be described.

  The urethane urea resin (1) used in the present invention is a polyol (A) containing an aliphatic cyclic structure-containing polycarbonate polyol (A-1) and an aromatic polyester polyol (A-2), and an aliphatic cyclic. It is obtained by reacting the structure-containing polyisocyanate (B) and the aliphatic cyclic structure-containing polyamine (C).

  The urethane urea resin (1) must have an aliphatic cyclic structure and an aromatic ring in order to achieve an excellent optical compensation function and durability. The urethane urea resin (1) has an aliphatic cyclic structure and an aromatic ring, so that it exhibits excellent durability and is obtained when the film is stretched. An excellent optical compensation function is exhibited even in a thin film by excellent stacking of an aromatic ring having higher planarity than a cyclic structure and an aliphatic cyclic structure and an aromatic ring.

  In addition, it is important that the aliphatic cyclic structure is supplied from any of the aliphatic cyclic structure-containing polycarbonate polyol, the aliphatic cyclic structure-containing polyisocyanate, and the aliphatic cyclic structure-containing polyamine. For example, a resin composition using an aliphatic polyisocyanate instead of an aliphatic cyclic structure-containing polyisocyanate even if the mass ratio of the aliphatic cyclic structure present in the urethane urea resin (1) is about the same. Then, an optical film having a desired optical compensation function and durability may not be formed.

  As the urethane urea resin (1), the mass ratio of the aliphatic cyclic structure is preferably in the range of 40 to 60% by mass from the viewpoint of obtaining an optical film having both excellent optical compensation function and durability. More preferably, it is in the range of 50 to 60% by mass. In addition, the mass ratio of the said aliphatic cyclic structure is a raw material used for manufacture of the said urethane urea resin (1), and an aliphatic cyclic structure containing polycarbonate polyol (A-1) and aromatic polyester polyol (A- 2) The ratio of the mass of the aliphatic cyclic structure in the raw material to the total mass of the aliphatic cyclic structure-containing polyisocyanate (B) and the aliphatic cyclic structure-containing polyamine (C).

  Moreover, as said urethane urea resin (1), it is preferable that the mass ratio of an aromatic ring is the range of 1-30 mass% from a viewpoint of obtaining the optical film which compatible the outstanding optical compensation function and durability. More preferably, it is in the range of ˜15% by mass. In addition, the mass ratio of the said aromatic ring is an aliphatic cyclic structure containing polycarbonate polyol (A-1) and aromatic polyester polyol (A-2) which are the raw materials used for manufacture of the said urethane urea resin (1). It is a ratio of the mass of the aromatic ring in the raw material to the total mass of the aliphatic cyclic structure-containing polyisocyanate (B) and the aliphatic cyclic structure-containing polyamine (C).

  The urethane urea resin (1) has a urethane bond and a urea bond. When so-called urethane acrylate having no urea bond is used, the molding processability is low and it may be difficult to produce a thin optical film. Therefore, as the urethane urea resin (1), it is possible to use those having 1 to 20% by mass of urea bonds from the viewpoint of achieving both good optical compensation function and durability as well as excellent moldability. Preferably, it is 1-15 mass%, More preferably, it is 1-10 mass%. In addition, the mass ratio of the said urea bond is an aliphatic cyclic structure containing polycarbonate polyol (A-1) and aromatic polyester polyol (A-2) which are the raw materials used for manufacture of the said urethane urea resin (1). It is a ratio of the mass of the urea bond structure in the raw material to the total mass of the aliphatic cyclic structure-containing polyisocyanate (B) and the aliphatic cyclic structure-containing polyamine (C).

  Moreover, as said urethane urea resin (1), it is preferable to use what has a 1-20 mass% urethane bond from a viewpoint which balances a favorable optical compensation function and durability with the outstanding moldability. 5 to 15% by mass is more preferable. In addition, the mass ratio of the said urethane bond is an aliphatic cyclic structure containing polycarbonate polyol (A-1) and aromatic polyester polyol (A-2) which are the raw materials used for manufacture of the said urethane urea resin (1). It is a ratio of the mass of the urethane bond structure in the raw material to the total mass of the aliphatic cyclic structure-containing polyisocyanate (B) and the aliphatic cyclic structure-containing polyamine (C).

  The weight average molecular weight of the urethane urea resin (1) is preferably 5,000 to 200,000 in order to maintain good molding processability as well as an excellent optical compensation function and durability, and is preferably 15,000 to 200,000. More preferred. The weight average molecular weight of the urethane urea resin (1) is a value determined by styrene conversion using gel permeation chromatography (GPC) and tetrahydrofuran as an eluent.

  Next, the aliphatic cyclic structure-containing polycarbonate polyol (A-1) used for the production of the urethane urea resin (1) will be described.

  As the aliphatic cyclic structure-containing polycarbonate polyol, for example, a carbonate ester and / or phosgene is reacted with an aliphatic cyclic structure-containing polyol (a-1) having a relatively low molecular weight of about 50 to 400 to be described later. Can be used.

  Examples of the carbonate ester include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, diphenyl carbonate, dinaphthyl carbonate, and phenyl naphthyl carbonate.

  Examples of the aliphatic cyclic structure-containing polyol (a-1) capable of reacting with the carbonate ester or phosgene include 1,2-cyclobutanediol, 1,3-cyclopentanediol, 1,4-cyclohexanediol, and cycloheptanediol. , Cyclooctanediol, 1,4-cyclohexanedimethanol, hydroxypropylcyclohexanol, tricyclo [5,2,1,0,2,6] decane-dimethanol, bicyclo [4,3,0] -nonanediol, di Cyclohexanediol, tricyclo [5,3,1,1] dodecanediol, bicyclo [4,3,0] nonanedimethanol, tricyclo [5,3,1,1] dodecane-diethanol, hydroxypropyltricyclo [5,3 , 1,1] dodecanol, spiro [3,4] octanediol, Tylcyclohexanediol, 1,1'-bicyclohexylidenediol, cyclohexanetriol, hydrogenated bisphenol A, 1,3-adamantanediol, etc. can be used, among which 1,4-cyclohexanedimethanol is used It is preferable to do.

  As the aliphatic cyclic structure-containing polycarbonate polyol (A-1), those having a hydroxyl value in the range of 30 to 230 mgKOH / g are preferably used, and those having a hydroxyl value in the range of 50 to 230 mgKOH / g are used. It is more preferable. The hydroxyl value of the polyol (A) is a value measured according to JIS K0070.

  Next, the aromatic polyester polyol (A-2) used for production of the urethane urea resin (1) will be described.

  The aromatic polyester polyol (A-2) is at least one aromatic compound selected from the group consisting of alkylene diol (a-2-1), terephthalic acid, naphthalenedicarboxylic acid, and dialkyl ester compounds thereof. (A-2-2) and an esterification reaction.

  The main structure of the aromatic polyester polyol (A-2) is as shown by the following general formula (1).

（上記一般式（１）中のＧはアルキレンジオール（ａ−２−１）の残基を表し、Ｔは芳香族化合物（ａ−２−２）の残基を表し、Ｒはアルキル基を表す。また、ｎは繰り返し数を表し、１以上の整数である。）

(G in the general formula (1) represents a residue of an alkylene diol (a-2-1), T represents a residue of an aromatic compound (a-2-2), and R represents an alkyl group. N represents the number of repetitions and is an integer of 1 or more.)

  The above “residue” means the following. The “residue” of the alkylene diol (a-2-1) represents the remaining organic group excluding the two hydroxyl groups that the alkylene diol (a-2-1) has before the reaction. The “residue” of the aromatic compound (a-2-2) represents the remaining organic group excluding the carboxyl group of terephthalic acid and / or naphthalenedicarboxylic acid.

  Examples of the alkylene diol (a-2-1) include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7- Linear alkylene diols such as heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol; propylene glycol (1, 2-propanediol), 2-methyl-1,3-propanediol, neopentyl glycol, 3,3-diethyl-1,3-propanediol, 3,3-dibutyl-1,3-propanediol, 1,2 -Butanediol, 1,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 2 3-pentanediol, 2,4-pentanediol, -methyl-1,5-pentanediol, 1,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, Branched alkylene diols such as 1,5-hexanediol; 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, diethylene glycol, dipropylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, hexylene glycol And other diols. These alkylene diols (a-2-1) can be used alone or in combination of two or more. Among these alkylene diols (a-2-1), the compatibility between the optical compensation function and durability and the compatibility with the aliphatic cyclic structure-containing polycarbonate polyol (A-1) are improved. A linear and / or branched alkylene diol having 2 to 12 carbon atoms is preferable, and a linear and / or branched alkylene diol having 2 to 6 carbon atoms is more preferable.

  Examples of the linear and / or branched alkylene diol having 2 to 12 carbon atoms include ethylene glycol, 1,2-propanediol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-propanediol, -Methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, neopentyl glycol and 1,6-hexanediol are more preferable, and optical Since high birefringence can be imparted to the film, ethylene glycol, 1,2-propylene glycol, and 3-methyl-1,5-pentanediol are particularly preferable.

  In the present invention, a monoalcohol or a polyhydric alcohol may be used in addition to the alkylene diol (a-2-1) as long as the effects of the present invention are not impaired. Examples of the monoalcohol include methanol, ethanol, 1-butanol, 2-butanol, hexanol, cyclohexanol, pentyl alcohol, octyl alcohol, lauryl alcohol, methyl lactate, and ethyl lactate. Examples of the polyhydric alcohol include glycerin, sorbitol, ribitol, pentaerythritol, dipentaerythritol and the like. These monoalcohols and polyhydric alcohols can be used alone or in combination of two or more. In order to impart high birefringence to the optical film of the present invention, the alkylene diol (a-2) in a total of 100 parts by mass of the alkylene diol (a-2-1) and monoalcohol or polyhydric alcohol. The amount of -1) used is preferably 95 parts by mass or more.

  The said aromatic compound (a-2-2) used by this invention is a terephthalic acid, naphthalene dicarboxylic acid, and those dialkyl ester compounds, These can be used individually or can also use 2 or more types together.

  When the dialkyl ester compound of terephthalic acid and / or naphthalenedicarboxylic acid is used as the (a-2-2), examples of the alkyl group include those having 1 to 8 carbon atoms, and those having 3 or more carbon atoms. May be a linear alkyl group or a branched alkyl group. Examples of such an alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group, and an octyl group. Two alkyl groups may be the same as or different from each other.

  Specific examples of the dialkyl ester compound of terephthalic acid include dimethyl terephthalate, diethyl terephthalate, dipropyl terephthalate, dibutyl terephthalate, dipentyl terephthalate, dihexyl terephthalate, and diheptyl terephthalate.

  Specific examples of the dialkyl ester compound of naphthalene dicarboxylic acid include dimethyl naphthalene dicarboxylate, diethyl naphthalene dicarboxylate, dipropyl naphthalene dicarboxylate, dibutyl naphthalene dicarboxylate, dipentyl naphthalene dicarboxylate, dihexyl naphthalene dicarboxylate, diheptyl naphthalene dicarboxylic acid Etc.

  Among the aromatic compounds (a-2-2), naphthalenedicarboxylic acid or a dialkyl ester compound thereof is preferable. Specifically, 1,4-naphthalenedicarboxylic acid or a dialkyl ester compound thereof, 1,5-naphthalene. Dicarboxylic acid or its dialkyl ester compound, 1,8-naphthalenedicarboxylic acid or its dialkyl ester compound, 2,3-naphthalenedicarboxylic acid or its dialkyl ester compound, 2,6-naphthalenedicarboxylic acid or its dialkyl ester compound are preferred. Among these, 2,6-naphthalenedicarboxylic acid or a dialkyl ester compound thereof is more preferable, and dimethyl 2,6-naphthalenedicarboxylic acid is more preferable.

  Furthermore, in the production of the aromatic polyester polyol (A-2), other dicarboxylic acids or their alkyl ester compounds or carbonate compounds can be used in combination as long as the effects of the present invention are not impaired. As said dicarboxylic acid or its alkylester compound, aliphatic dicarboxylic acid or aromatic dicarboxylic acid, or these alkylester compounds can be used. Examples of the aliphatic dicarboxylic acid or its alkyl ester compound include succinic acid, dimethyl succinate, glutaric acid, dimethyl glutarate, adipic acid, dimethyl adipate, diethyl adipate, dibutyl adipate, pimelic acid, dimethyl pimelate. , Suberic acid, dimethyl suberate, azelaic acid, dimethyl azelate, sebacic acid, dimethyl sebacate, decanedicarboxylic acid, dimethyl decanedicarboxylate, cyclohexanedicarboxylic acid, dimethyl cyclohexanedicarboxylate, dimer acid, dimethyl dimer acid, fumaric acid, And dimethyl fumarate. Examples of the aromatic dicarboxylic acid or its alkyl ester compound include phthalic acid, dimethyl phthalate, isophthalic acid, dimethyl isophthalate and the like. Furthermore, examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, and dibutyl carbonate. These other dicarboxylic acids or their alkyl ester compounds or carbonate compounds can be used alone or in combination of two or more. In order to impart high birefringence to the optical film of the present invention, the aromatic compound (a-2-2) in a total of 100 parts by mass of the aromatic compound (a-2-2) and other dicarboxylic acids and the like. The amount of 2) used is preferably 95 parts by mass or more.

  The aromatic polyester polyol (A-2) used in the present invention is charged with the alkylene diol (a-2-1) and the aromatic compound (a-2-2) in a reactor and heated to an ester. It can obtain by making it react.

  As the reaction equipment used when the aromatic polyester polyol (A-2) is produced, reaction equipment corresponding to pressurization and decompression is preferable, and a reactor, a stirrer, a rectifying column, a reflux condenser, A general apparatus equipped with a pump or the like can be used.

  When producing the aromatic polyester polyol (A-2), it is preferable to use an esterification catalyst for the purpose of promoting the esterification reaction. Examples of the esterification catalyst include at least one metal or organometallic compound selected from the group consisting of Group 2, Group 3, Group 12, Group 13, and Group 14 of the Periodic Table. More specifically, for example, metals such as titanium, tin, zinc, aluminum, zirconium, magnesium, hafnium, germanium; titanium tetraisopropoxide, titanium tetrabutoxide, titanium oxyacetylacetonate, tin octoate, 2-ethyl Examples thereof include metal compounds such as hexanetin, acetylacetonate zinc, zirconium tetrachloride, zirconium tetrachloride tetrahydrofuran complex, hafnium tetrachloride, hafnium tetrachloride, hafnium tetrachloride complex, germanium oxide, and tetraethoxygermanium. Among these, the reactivity can be improved, the handling is easy, and the storage stability of the aromatic polyester polyol (A-2) obtained by the esterification reaction is good. Coxides are preferable, and specifically, zinc acetate, zinc benzoate, titanium tetraisopropoxide, titanium tetrabutoxide, titanium oxyacetylacetonate, and the like are preferably used.

  The esterification catalyst may be used in an amount that can control the esterification reaction and suppress the coloring of the aromatic polyester polyol (A-2) to be obtained. The alkylene diol (a-2 -1) and the aromatic compound (a-2-2), the range is preferably 10 to 1,000 ppm, more preferably 20 to 500 ppm, and particularly preferably 30 to 300 ppm. . Since the coloring of the aromatic polyester polyol (A-2) reduces the transparency of the film, it is necessary to pay particular attention to the optical film application that requires high transparency.

  When the aromatic polyester polyol (A-2) is produced, the esterification catalyst is added to the reactor with the alkylene diol (a-2-1) and the aromatic compound (a-2-2). May be added at the same time as charging, or may be added during the temperature rise or at the start of pressure reduction, or the esterification catalyst may be added in portions.

  Moreover, when the said alkylene diol (a-2-1) and the said aromatic compound (a-2-2) are made to react, the said aromatic polyester polyol (A-2) in the range which does not inhibit the effect of this invention. ) For the purpose of branching and increasing the molecular weight, a trihydric or higher polyhydric alcohol or carboxylic acid such as glycerin, pentaerythritol, trimellitic acid or pyromellitic acid; or a polyisocyanate such as hexamethylene diisocyanate may be used. Good.

  The reaction temperature when producing the aromatic polyester polyol (A-2) is such that the alkylene diol (a-2-1) as the raw material and the aromatic compound (a-2-2) are evaporated or sublimated. The range of 120 ° C. to 300 ° C. is preferable, and the range of 150 ° C. to 280 ° C. is preferred because the reaction can be promoted while suppressing the thermal decomposition and coloring of the aromatic polyester polyol (A-2) produced by the reaction. Is more preferable. The reaction time for producing the aromatic polyester polyol (A-2) is preferably 2 hours or more, and more preferably in the range of 4 to 100 hours.

  Further, when the aromatic polyester polyol (A-2) is produced, the reaction may be performed under reduced pressure from the middle of the reaction for the purpose of removing unreacted raw materials and low molecular weight products and for promoting the reaction. preferable. The degree of vacuum when producing the aromatic polyester polyol (A-2) is 3,000 Pa or less because unreacted raw materials and low molecular weight products can be quickly removed and the reaction can be accelerated. Preferably, it is 2,000 Pa or less, and more preferably in the range of 10 to 1,000 Pa.

  The hydroxyl value of the aromatic polyester polyol (A-2) obtained by the above production method is preferably in the range of 20 to 380 from the viewpoint of reactivity with the aliphatic cyclic structure-containing polyisocyanate described later. , 40 to 320 is more preferable, and 60 to 280 is more preferable. In addition, this hydroxyl value originates in the terminal hydroxyl group of aromatic polyester polyol (A-2), ie, the hydroxyl group which alkylene diol (a-2-1) used as a raw material has.

  The number average molecular weight of the aromatic polyester polyol (A-2) has good compatibility with the aliphatic cyclic structure-containing polycarbonate polyol (A-1), and the optical film of the present invention has smoothness and transparency. Since it becomes favorable, the range of 300-5000 is preferable, The range of 350-3000 is more preferable, The range of 400-2000 is further more preferable, The range of 400-800 is especially preferable.

  In addition, the number average molecular weight of the aromatic polyester polyol (A-2) in the present invention is measured using a gel permeation chromatograph (GPC) using tetrahydrofuran (THF) as an eluent. It can be obtained as a converted value.

In the present invention, it is important that the aromatic polyester polyol (A-2) is incorporated into the urethane urea resin (1) skeleton.
When the (A-2) is not incorporated in the urethane urea resin (1) skeleton, a desired optical compensation function cannot be obtained. Further, when the (A-2) is not incorporated into the urethane urea resin (1) skeleton, a desired optical compensation function can be obtained even if the (A-2) is added later as an additive. I can't.

  The mass ratio of the aromatic ring in the aromatic polyester polyol (A-2) is preferably 30 to 90% by mass, and 40 to 80% by mass from the viewpoint of further improving the optical compensation function and durability. It is more preferable.

  Next, the polyol (A) used for manufacture of the said urethane urea resin (1) is demonstrated.

The polyol (A) is an aliphatic cyclic structure-containing polycarbonate polyol (A-
1) and the aromatic polyester polyol.

  The ratio of the mass ratio of the (A-1) and the (A-2) in the polyol (A) is 90/10 to 60/40 from the viewpoint of the balance between the optical compensation function and the durability. It is preferable that the ratio is 85/15 to 75/25.

  Moreover, it is preferable that the mass ratio of the aromatic ring in the said polyol (A) is 1-40 mass% from a viewpoint which can improve an optical compensation function and durability more, and it is 1-10 mass%. More preferred. In addition, the mass ratio of the aromatic ring in the said polyol (A) shows the mass ratio of an aromatic ring with respect to the total mass of said (A-1) and said (A-2).

  Moreover, as said polyol (A), as long as the effect of this invention is not impaired, you may contain other polyols other than said (A-1) and (A-2).

Examples of the other polyols include aliphatic cyclic structure-containing polyester polyols, aliphatic cyclic structure-containing polyether polyols, aliphatic cyclic structure-containing polyols such as aliphatic cyclic structure-containing acrylic polyols, and aromatic polyethers. Polyol, aromatic polycarbonate polyol, aromatic polyol such as aromatic polyacryl polyol, aliphatic polyester polyol, aliphatic polycarbonate polyol, aliphatic polyacryl polyol, aliphatic polyol such as aliphatic polyether polyol, ethylene glycol, 1, 2-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 3,3′-dimethylol Heptane, 1, 4 -Chain extenders such as cyclohexanedimethanol, neopentyl glycol, 3,3-bis (hydroxymethyl) heptane, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, sorbitol, hydroquinone diethylol ether, etc. The above can be used in combination.

  The total mass of the aliphatic cyclic structure-containing polycarbonate polyol (A-1) and the aromatic polyester polyol (A-2) is an aliphatic ring that is a raw material used for the production of the urethane urea resin (1) of the present invention. For the total mass of the formula structure-containing polycarbonate polyol (A-1), the aromatic polyester polyol (A-2), the aliphatic cyclic structure-containing polyisocyanate (B), and the aliphatic cyclic structure-containing polyamine (C). , Preferably in the range of 40 to 80% by mass.

  Next, the aliphatic cyclic structure-containing polyisocyanate (B) will be described.

  Examples of the aliphatic cyclic structure-containing polyisocyanate (B) include isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4- and / or 2,6-methylcyclohexane diisocyanate, cyclohexylene diisocyanate, and methylcyclohexylene. Use diisocyanate, bis (2-isocyanatoethyl) -4-cyclohexylene-1,2-dicarboxylate and 2,5- and / or 2,6-norbornane diisocyanate, dimer acid diisocyanate, bicycloheptane triisocyanate, etc. be able to. Of these, diisocyanate is preferably used from the viewpoint of imparting excellent optical compensation function and durability to the optical film of the present invention, and isophorone diisocyanate or 4,4′-dicyclohexylmethane diisocyanate is more preferably used. It is particularly preferred to use 4,4'-dicyclohexylmethane diisocyanate.

  In the present invention, in addition to the aliphatic cyclic structure-containing polyisocyanate (B), if necessary, aromatic polyisocyanates such as phenylene diisocyanate and tolylene diisocyanate, and aliphatic polyisocyanates such as hexamethylene diisocyanate. Other polyisocyanates such as can be used in combination.

  The aliphatic cyclic structure-containing polyisocyanate (B) includes an aliphatic cyclic structure-containing polycarbonate polyol (A-1) and an aromatic polyester polyol (A), which are raw materials used for the production of the urethane urea resin (1) to be obtained. -2), the aliphatic cyclic structure-containing polyisocyanate (B), and the aliphatic cyclic structure-containing polyamine (C) are preferably used in the range of 15 to 50% by mass.

  Next, the aliphatic cyclic structure-containing polyamine (C) will be described.

  The aliphatic cyclic structure-containing polyamine (C) is used for introducing a urea bond into the urethane urea resin.

  As the aliphatic cyclic structure-containing polyamine (C), for example, isophorone diamine, 4,4′-dicyclohexylmethane diamine, diaminocyclohexane, methyldiaminocyclohexane, biperazine, norbornene diamine, and the like can be used. In particular, it is preferable to use isophoronediamine and 4,4′-dicyclohexylmethanediamine from the viewpoint of improving the optical compensation function and durability.

  Moreover, in this invention, the aliphatic polyamine conventionally known as chain extenders, such as ethylenediamine other than the said aliphatic cyclic structure containing polyamine (C), as needed, does not impair the effect of this invention. You may use together in the range.

  The aliphatic cyclic structure-containing polyamine (C) includes an aliphatic cyclic structure-containing polycarbonate polyol (A-1) and an aromatic polyester polyol (A-), which are raw materials used for the production of the urethane urea resin (1) to be obtained. It is preferable to use in 1-20 mass% with respect to the total mass of 2), an aliphatic cyclic structure containing polyisocyanate (B), and an aliphatic cyclic structure containing polyamine (C).

  Next, the solvent (2) used in the present invention will be described.

  As the solvent (2), an organic solvent and an aqueous solvent can be used, but it is more preferable to use an organic solvent from the viewpoint of further improving the moldability of the optical film.

  When an organic solvent is used as the solvent (2), it is not particularly limited. For example, alcohol such as methanol, isopropanol, 2-butanol, n-butanol, isopropyl alcohol, ethylene glycol monomethyl ether acetate, ethyl acetate, butyl acetate , Ethyl lactate, cellosolve, cellosolve acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, dimethylformamide, dimethylacetamide, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, acetonitrile, dimethyl sulfoxide, N-methylpyrrolidone, N-ethylpyrrolidone and the like can be used, and these may be used alone or in combination. Moreover, these organic solvents are suitably selected according to the use used. Among these, it is preferable to contain an alcohol in order to deactivate unreacted isocyanate groups and terminal isocyanate groups of the urethane urea resin after the production of the urethane urea resin described later.

  Moreover, in order to deactivate the unreacted isocyanate group or the terminal isocyanate group of the urethane urea resin, a hydroxyl group-containing (meth) acrylic compound may be used in addition to using the alcohol as the solvent.

  Examples of the hydroxyl group-containing (meth) acrylic compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. A hydroxyl group-containing alkyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, or the like can be used.

  Moreover, it is preferable that the mass ratio of the said urethane urea resin (1) and the said solvent (2) in the urethane urea resin composition of this invention is (1) / (2) = 10-50 / 90-50. More preferably, it is 15-35 / 85-65.

  Next, a method for producing the urethane urea resin (1) will be described.

  As a manufacturing method of the said urethane urea resin (1), the method of the following manufacturing method (i)-manufacturing method (ii) is mentioned, for example. Among these, the production by the following method (i) is preferable because the reaction can be easily controlled.

  In the production method (i), the aliphatic cyclic structure-containing polycarbonate polyol (A-1) and the aromatic polyester polyol (A-2) and, if necessary, the other polyol under the solvent (2) To obtain a urethane prepolymer having an isocyanate group at the molecular end, by reacting the polyol (A) containing the aliphatic cyclic structure-containing polyisocyanate (B) with the urethane prepolymer, This is a method for producing a urethane urea resin (1) by reacting the aliphatic cyclic structure-containing polyamine (C).

  The reaction between the polyol (A) and the aliphatic cyclic structure-containing polyisocyanate (B) is equivalent to the hydroxyl group of the polyol (A) and the isocyanate group of the aliphatic cyclic structure-containing polyisocyanate (B). The ratio [isocyanate group / hydroxyl group] is preferably 1.1 / 1.0 to 5.0 / 1.0, preferably 1.5 / 1.0 to 3.0 / 1.0. It is more preferable. The reaction between the polyol (A) and the aliphatic cyclic structure-containing polyisocyanate (B) is preferably carried out under a condition of 20 to 120 ° C. for about 30 minutes to 24 hours.

  A urethane prepolymer having an isocyanate group at the molecular end, obtained by a reaction between the polyol (A) and the aliphatic cyclic structure-containing polyisocyanate (B); and the aliphatic cyclic structure-containing polyamine (C); For example, the urethane urea resin (1) can be produced by supplying and reacting the urethane prepolymer and the aliphatic cyclic structure-containing polyamine (C) all together or sequentially. At that time, the equivalent ratio [amino group / isocyanate group] of the isocyanate group of the urethane prepolymer and the amino group of the aliphatic cyclic structure-containing polyamine (C) is 0.70 / 1.0 to 0.99 / The range is preferably 1.0, and more preferably in the range of 0.80 / 1.0 to 0.99 / 1.0, particularly from the viewpoint of durability. Moreover, it is preferable to make reaction with the said urethane prepolymer and the said aliphatic cyclic structure containing polyamine (C) react for about 1 to 3 hours on the conditions of 20-80 degreeC.

  Moreover, the said manufacturing method (ii) makes the molecular terminal by reacting the said aliphatic cyclic structure containing polyisocyanate (B) and the said aliphatic cyclic structure containing polyamine (C) under the said solvent (2). This is a method for producing a urethane urea resin (1) by obtaining a polyurea prepolymer having an isocyanate group and then reacting the polyurea prepolymer with the polyol (A).

  The reaction between the aliphatic cyclic structure-containing polyisocyanate (B) and the aliphatic cyclic structure-containing polyamine (C) is carried out by reacting the isocyanate group of the aliphatic cyclic structure-containing polyisocyanate (B) with the aliphatic ring. It is preferable that the equivalent ratio [isocyanate group / amino group] of the amino group of the formula structure-containing polyamine (C) is 1.1 / 1.0 to 5.0 / 1.0. The reaction between the aliphatic cyclic structure-containing polyisocyanate (B) and the aliphatic cyclic structure-containing polyamine (C) is preferably carried out at a temperature of 20 to 80 ° C. for about 30 minutes to 1 hour. .

  A polyurea prepolymer having an isocyanate group at the molecular end obtained by the reaction of the aliphatic cyclic structure-containing polyisocyanate (B) and the aliphatic cyclic structure-containing polyamine (C); and the polyol (A). For example, the urethane urea resin (1) can be produced by supplying and reacting the polyurea prepolymer and the polyol (A) all at once or sequentially.

  When producing the urethane urea resin (1), a reaction is carried out using a tertiary amine catalyst or an organometallic catalyst, as necessary, in any of the production methods (i) and (ii). Can be promoted.

  The urethane urea resin composition of the present invention containing the urethane urea resin (1) and the solvent (2) obtained by the above method may contain other additives as necessary.

  Examples of the other additives include fillers, pigments, dyes, surfactants, antistatic agents, ultraviolet absorbers, polymerization inhibitors, adhesion promoters, plasticizers, antioxidants, leveling agents, and film formation. Auxiliaries, stabilizers, flame retardants, excipients, photocuring agents, thermosetting agents, curing accelerators, retardation control agents, retardation improving agents, and the like can be used as long as the effects of the present invention are not impaired. .

  The urethane urea resin composition of the present invention includes, for example, ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, propylene glycol monoallyl ether, dipropylene glycol monoallyl ether, 1,2-butylene glycol monoallyl ether, Allyl ether compounds of polyhydric alcohols such as methylolpropane diallyl ether, glyceryl diallyl ether, pentaerythritol triallyl ether, 1,6-hexanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, Ethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra You may contain polyfunctional (meth) acrylic compounds, such as (meth) acrylate and dipentaerythritol hexa (meth) acrylate.

  Next, the manufacturing method of the optical film of this invention is demonstrated.

  The method for producing the optical film includes a polyol (A) containing an aliphatic cyclic structure-containing polycarbonate polyol (A-1) and an aromatic polyester polyol (A-2), an aliphatic cyclic structure-containing polyisocyanate ( A urethane urea resin composition containing a urethane urea resin (1) and a solvent (2) obtained by reacting B) with an aliphatic cyclic structure-containing polyamine (C) is applied to a substrate; The method includes the steps (i) of obtaining a film by drying the coated substrate and the step (ii) of stretching the film.

  First, the step (i) will be described.

  Although it does not specifically limit as said base material, For example, metals, such as glass, rubber | gum, quartz, ceramic, aluminum, copper, nickel, various plastics, etc. can be illustrated.

  Examples of the plastic include silicon resin, acrylic resin, epoxy resin, fluorine resin, polystyrene resin, vinyl chloride resin, PC (polycarbonate), PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), and modified PPE (polyphenylene ether). ), PEN (polyethylene naphthalate), PET (polyethylene terephthalate), COP (cycloolefin polymer), TAC (triacetyl cellulose) and the like.

  The method for applying the urethane urea resin composition to the substrate is not particularly limited, and for example, coating is performed by a slit coater method such as a curtain flow coater method or a die coater method, a knife coater method, a roll coater method, or the like. A method is mentioned.

  As a method for drying the coated substrate, it is sufficient that the solvent (2) can be practically removed, and natural drying may be performed at room temperature, or heating drying may be performed. Especially, it is preferable to heat-dry from a viewpoint which can shorten drying time, and the said heat-drying is 40-250 degreeC normally, Preferably it is 60-150 degreeC, about 1-10 minutes, Preferably it is 1-30 minutes It is preferable to carry out in about the time.

  Since the solvent (2) in the urethane urea resin composition is removed after the drying, a laminate of the film and the substrate is obtained. Next, the film is obtained by peeling only the film from the laminate.

  In addition, as a film thickness of the said film, although it determines suitably by the draw ratio mentioned later and the film thickness of the optical film obtained, it is preferable that it is generally 10-500 micrometers.

  Next, step (ii) for stretching the film will be described.

  The stretching process of the film is for orienting molecules in the urethane urea resin composition to develop an optical compensation function.

  When stretching the film, it is common to heat the film for stretching. The heating temperature for stretching the film (hereinafter referred to as stretching temperature) is generally 100 to 250 ° C., but as the stretching temperature becomes higher, the orientation of molecules contained in the resin is generally increased. Becomes messy, resulting in a decrease in the optical compensation function. On the other hand, in this invention, extending | stretching temperature can be lowered | hung by using the said urethane urea resin composition. Accordingly, the stretching temperature of the present invention is preferably 140 to 170 ° C.

Moreover, when extending | stretching the said film, it is common to carry out uniaxial or biaxial stretching with respect to a film in the vertical and / or horizontal direction. As the stretching ratio when the uniaxial or biaxial stretching,
Although it is appropriately determined depending on the value of the optical compensation function according to the intended use and the thickness of the film before stretching, it is preferably about 1.5 to 4 times.

  In general, the film thickness of an optical film is required to be 300 μm or less, preferably 100 μm or less, with the recent thinning of liquid crystal displays. In general, an optical film having an in-plane retardation value (Re) of the optical film described later and a retardation value (Rth) in the thickness direction of the optical film of approximately 100 nm or more is good optical compensation. It is evaluated as an optical film having a function. The optical film of the present invention obtained by the above method has a good optical compensation function and durability even with a film thickness of 5 μm. However, the film thickness of the optical film of the present invention is appropriately determined according to the intended use and is preferably 5 to 100 μm, more preferably 5 to 50 μm.

  The optical film of the present invention can be used as a viewing angle compensation film, a polarizing plate protective film, a retardation film, an antireflection film, an antiglare film and the like. Among these, since the optical film of the present invention is excellent in the optical compensation function and durability, it can be particularly suitably used as a retardation film.

[Synthesis Example 1]
<Synthesis of Aromatic Polyester Polyol (A-2-1)>
In a three-liter four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 659.4 g of dimethyl 2,6-naphthalenedicarboxylate, 58.3 g of dimethyl terephthalate, 1,2-propylene glycol 684. 8 g and 0.084 g of zinc acetate dihydrate as an esterification catalyst were charged, the temperature was raised stepwise to 210 ° C. while stirring under a nitrogen stream, and the reaction was conducted for a total of 13 hours. After the reaction, unreacted 1,2-propylene glycol is removed under reduced pressure at 160 ° C. to obtain a normal temperature solid aromatic polyester polyol (A-2-1) (acid value: 0.08, hydroxyl value: 213, number Average molecular weight: 590) was obtained.

[Measurement conditions for acid value and hydroxyl value of aromatic polyester polyol (A-2-1)]
The acid value and hydroxyl value of each ester compound were measured according to JIS K 0070-1992.

[Measurement Conditions for Number Average Molecular Weight (Mn) of Aromatic Polyester Polyol (A-2-1)]
Measuring device: High-speed GPC device “HLC-8320GPC” manufactured by Tosoh Corporation
Column: “TSK GARDCOLUMN SuperHZ-L” manufactured by Tosoh Corporation
+ "TSK gel SuperHZM-M" manufactured by Tosoh Corporation
+ "TSK gel SuperHZM-M" manufactured by Tosoh Corporation
+ Tosoh Corporation “TSK gel SuperHZ-2000”
+ Tosoh Corporation “TSK gel SuperHZ-2000”
Detector: RI (differential refractometer)
Data processing: “EcoSEC Data Analysis version 1.07” manufactured by Tosoh Corporation
Column temperature: 40 ° C
Developing solvent: Tetrahydrofuran Flow rate: 0.35 mL / min Measurement sample: 15 mg of a sample was dissolved in 10 ml of tetrahydrofuran, and the obtained solution was filtered through a microfilter to obtain a measurement sample.
Sample injection volume: 20 μl
Standard sample: The following monodisperse polystyrene having a known molecular weight was used according to the measurement manual of “HLC-8320GPC”.

(Monodispersed polystyrene)
“A-300” manufactured by Tosoh Corporation
“A-500” manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
“F-1” manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
“F-4” manufactured by Tosoh Corporation
“F-10” manufactured by Tosoh Corporation
“F-20” manufactured by Tosoh Corporation
“F-40” manufactured by Tosoh Corporation
“F-80” manufactured by Tosoh Corporation
“F-128” manufactured by Tosoh Corporation
“F-288” manufactured by Tosoh Corporation

[Example 1]
<Synthesis of urethane urea resin composition (x)>
An aliphatic cyclic structure-containing polycarbonate polyol (UC-100, manufactured by Ube Industries, Ltd., hydroxyl value) was added to a 5-liter four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser. 116.4 mg KOH / g) 300 parts by mass and 75 parts by mass of the aromatic polyester polyol (A-2-1) obtained in Synthesis Example 1 were charged, 248.0 parts by mass of 4,4′-dicyclohexylmethane diisocyanate, and toluene. 330.1 parts by mass was added, and a toluene solution of a urethane prepolymer having an isocyanate group at the molecular end was obtained by reacting at 80 ° C. for 3 hours while suppressing heat generation.

  Subsequently, after mixing the toluene solution, 1235.6 parts by mass of N, N-dimethylformamide, 287.7 parts by mass of toluene, and 205.9 parts by mass of sec-butanol, the mixture was cooled to 40 ° C., It was mixed with 73.4 parts by mass of isophoronediamine and reacted at 70 ° C. for 3 hours to obtain a urethane urea resin composition (x) (weight average molecular weight; 147000, nonvolatile content: 25% by mass).

  The obtained urethane urea resin composition (x) was coated on a release polyethylene terephthalate (PET) film by bar coating, and then the coated substrate was dried in a hot air dryer at 100 ° C. for 20 minutes. Thereafter, only the film was peeled from the laminate of the obtained film and the release PET film. The film thickness of the obtained film was 52 μm.

  The film was cut into a length of 45 mm × 45 mm, and the cut film was placed in a biaxial stretching machine (“IMC-190B type” manufactured by Imoto Seisakusho Co., Ltd.) and 30 mm at a stretching temperature of 160 ° C. At a speed of / min, the film was uniaxially stretched 3 times to a length of 135 mm to obtain an optical film having a thickness of 31 μm.

[Comparative Example 1]
<Synthesis of urethane urea resin composition (y)>
An aliphatic cyclic structure-containing polycarbonate polyol (UC-100, manufactured by Ube Industries, Ltd., hydroxyl value) was added to a 5-liter four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser. 116.4 mgKOH / g) 437.3 parts by mass, 234.0 parts by mass of 4,4′-dicyclohexylmethane diisocyanate, 363.6 parts by mass of toluene, and reaction at 80 ° C. for 3 hours while suppressing heat generation Thus, a toluene solution of a urethane prepolymer having an isocyanate group at the molecular end was obtained.

  Subsequently, after mixing the toluene solution, 1358.2 parts by mass of N, N-dimethylformamide, 315.4 parts by mass of toluene, and 226.3 parts by mass of sec-butanol, the mixture was cooled to 40 ° C., A urethane urea resin composition (y) (weight average molecular weight: 128000, nonvolatile content: 25% by mass) was obtained by mixing with 73.4 parts by mass of isophoronediamine and reacting at 70 ° C. for 3 hours.

  The obtained urethane urea resin composition (y) was coated on a release polyethylene terephthalate (PET) film by bar coating, and then the coated substrate was dried in a hot air dryer at 100 ° C. for 20 minutes. Thereafter, only the film was peeled from the laminate of the obtained film and the release PET film. The film thickness of the obtained film was 50 μm.

  The film was cut into a length of 45 mm × 45 mm, and the cut film was placed in a biaxial stretching machine (“IMC-190B type” manufactured by Imoto Seisakusho Co., Ltd.) and 30 mm at a stretching temperature of 160 ° C. An attempt was made to stretch the film uniaxially three times at a speed of / min until the length became 135 mm. However, since the film was strong and could not be stretched, an optical film could not be obtained.

[Comparative Example 2]
In Comparative Example 1, the film was stretched under the same conditions as in Comparative Example 1 except that the stretching temperature was changed to 180 ° C., and an optical film having a film thickness of 29 μm was obtained.

[Comparative Example 3]
<Synthesis of urethane urea resin composition (z)>
To 100 parts by mass of the urethane urea resin composition (y) obtained in Comparative Example 1, 2.7 parts by mass of the aromatic polyester polyol (A-2-1) obtained in Synthesis Example 1 is added and mixed. A urethane urea resin composition (z) was obtained.

  The obtained urethane urea resin composition (z) was coated on a release polyethylene terephthalate (PET) film by bar coating, and then the coated substrate was dried in a hot air dryer at 100 ° C. for 20 minutes. Thereafter, only the film was peeled from the laminate of the obtained film and the release PET film. The film thickness of the obtained film was 55 μm.

  The film was cut into a length of 45 mm × 45 mm, and the cut film was placed in a biaxial stretching machine (“IMC-190B type” manufactured by Imoto Seisakusho Co., Ltd.) and 30 mm at a stretching temperature of 160 ° C. At a speed of / min, the film was uniaxially stretched 3 times to a length of 135 mm to obtain an optical film having a thickness of 32 μm.

[Method for measuring weight average molecular weight of urethane urea resin]
The weight average molecular weights of the urethane urea resins obtained in Example 1 and Comparative Example 1 were determined by standard polystyrene conversion by gel permeation chromatography (GPC). A solid content of 0.4 g of the obtained urethane urea resin composition was dissolved in 100 g of tetrahydrofuran to prepare a measurement sample.
The measuring device used was a high performance liquid chromatograph HLC-8220 manufactured by Tosoh Corporation. As a column, Tosoh Corporation column TSK-GEL (HXL-H, G5000HXL, G4000HXL, G3000HXL, G2000HXL) was used in combination.
As measurement conditions, the column temperature was 40 ° C., the eluent was tetrahydrofuran, the flow rate was 1.0 mL / min, the sample injection amount was 500 μL, and the standard polystyrene was TSK standard polystyrene.

[Evaluation method of optical compensation function]
In the present invention, the optical compensation function refers to optical anisotropy for developing a wide viewing angle.
The optical anisotropy can be generally grasped by a retardation value. Therefore, in the present invention, the optical compensation function was evaluated by the in-plane retardation value (Re) of the optical film and the retardation value (Rth) in the thickness direction of the optical film.

Specifically, the optical film obtained in Example 1 and Comparative Examples 2 and 3 was subjected to the surface of the optical film using an automatic birefringence meter (“KOBRA WR” manufactured by Oji Scientific Instruments). The internal retardation value (Re) and the retardation value (Rth) in the thickness direction of the optical film were measured. Measurement conditions were as follows: humidity was adjusted for 12 hours or more in an environment of a temperature of 23 ° C. and a relative humidity of 20%, and then the measurement was performed in the same environment.
In Comparative Example 1, an optical film was not obtained, and the optical compensation function could not be evaluated.

The retardation value (Rth) in the thickness direction of the optical film is a value defined by the following formula (2).
Rth = {(nx + ny) / 2−Nz} × d (nm) (2)
(In the formula (1), Nx: refractive index of the slow axis in the optical film plane, Ny: refractive index of the fast axis in the optical film plane, Nz: refractive index in the thickness direction of the optical film)

[Durability evaluation method]
Durability was evaluated by the heat shrinkage rate of the optical film.
Specifically, the optical film (135 mm long) obtained in Example 1 and Comparative Examples 2 and 3 was left in a hot air dryer at 85 ° C. for 24 hours, and then the vertical length of the optical film was measured. The heat shrinkage rate of the optical film was calculated from the following formula (3).
Thermal shrinkage rate (%) of optical film = {Vertical length of optical film (mm) / 135 (mm)} × 100 after standing in hot air dryer at 85 ° C. for 24 hours
In addition, the thing whose heat shrinkage rate of the said optical film is 97% or more was evaluated as "(circle)", and the thing below 97% was evaluated as "*".
In Comparative Example 1, an optical film was not obtained, and durability could not be evaluated.

Abbreviations in Table 1 will be described.
“CH-PC” is UC-100 (1,4-cyclohexanedimethanol-based polycarbonate polyol, hydroxyl value: 116.4) manufactured by Ube Industries, Ltd.
“H12MDI” is 4,4′-dicyclohexylmethane diisocyanate.
“IPDA” is isophoronediamine.

Claims (18)

Polyol (A) containing aliphatic cyclic structure-containing polycarbonate polyol (A-1) and aromatic polyester polyol (A-2), aliphatic cyclic structure-containing polyisocyanate (B), and aliphatic cyclic An optical film obtained using a urethane urea resin composition containing a urethane urea resin (1) and a solvent (2) obtained by reacting a structure-containing polyamine (C). The aromatic polyester polyol (A-2) is an aromatic compound selected from the group consisting of alkylene diol (a-2-1), terephthalic acid, naphthalenedicarboxylic acid, and dialkyl ester compounds thereof. The optical film according to claim 1, which is obtained by subjecting (a-2-2) to an esterification reaction. The optical film according to claim 2, wherein the alkylene diol (a-2-1) is a linear and / or branched alkylene diol having 2 to 12 carbon atoms. The linear or branched alkylene diol having 2 to 12 carbon atoms is ethylene glycol, 1,2-propanediol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-propanediol, 2-methyl- One selected from the group consisting of 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, neopentyl glycol and 1,6-hexanediol The optical film according to claim 3, which is the above alkylene diol. The optical film according to claim 2 or 3, wherein the alkylene diol (a-2-1) is 1,2-propanediol. The optical film according to claim 2, wherein the aromatic compound (a-2-2) is naphthalenedicarboxylic acid or a dialkyl ester compound thereof. The optical film according to claim 6, wherein the naphthalenedicarboxylic acid is 2,6-naphthalenedicarboxylic acid. The optical film according to claim 6, wherein the dialkyl ester compound of naphthalenedicarboxylic acid is dimethyl 2,6-naphthalenedicarboxylate. The optical film according to claim 1, wherein the aromatic polyester polyol (A-2) has a number average molecular weight in the range of 300 to 5,000. The optical film of any one of Claims 1-9 whose mass ratio of an aromatic ring in the said aromatic polyester polyol (A-2) is 40-80 mass%. The optical film of any one of Claims 1-10 whose mass ratio of an aromatic ring in the said polyol (A) is 1-40 mass%. The mass ratio of the said urethane urea resin (1) and the said solvent (2) in the said urethane urea resin composition is (1) / (2) = 10-50 / 90-50 of Claims 1-11. The optical film according to any one of the above. The aliphatic cyclic structure-containing polycarbonate polyol (A-1), the aromatic polyester polyol (A-2), the aliphatic cyclic structure-containing polyisocyanate (B), and the aliphatic cyclic, which are raw materials for producing the urethane urea resin The optical film of any one of Claims 1-12 whose mass ratio of an aliphatic cyclic structure with respect to the total mass of structure containing polyamine (C) is 40-60 mass%. The optical film of any one of Claims 1-13 whose hydroxyl value of the said aliphatic cyclic structure containing polycarbonate polyol (A-1) is 30-230 mgKOH / g. The aliphatic cyclic structure-containing polycarbonate polyol (A-1) is obtained by reacting 1,4-cyclohexanedimethanol with a carbonate and / or phosgene. 2. An optical film according to item 1. The optical according to any one of claims 1 to 15, wherein the aliphatic cyclic structure-containing polyisocyanate (B) is at least one selected from the group consisting of 4,4'-dicyclohexylmethane diisocyanate and isophorone diisocyanate. Film . The optical film according to any one of claims 1 to 16, wherein the urethane urea resin (1) has a weight average molecular weight of 5,000 to 200,000. Polyol (A) containing aliphatic cyclic structure-containing polycarbonate polyol (A-1) and aromatic polyester polyol (A-2), aliphatic cyclic structure-containing polyisocyanate (B), and aliphatic cyclic A urethane urea resin composition containing a urethane urea resin (1) and a solvent (2) obtained by reacting the structure-containing polyamine (C) is applied to a substrate, and then the coated substrate is dried. A method for producing an optical film, comprising: a step (i) for obtaining a film; and a step (ii) for stretching the film.