TW201329628A - Active energy ray-curable composition for molding optical film, optical film, polarizer protecting film and polarizing plate - Google Patents

Abstract

In this invention, the active energy ray-curable composition for molding optical film comprises the urethane methacrylate (A) having a photoelastic modulus of curing article at 23 DEG C (hereinafter referred to as photoelastic modulus.) of below 30x10<SP>-12</SP> Pa<SP>-1</SP>, and the polymer (B) except to the component (A) having a photoelastic modulus of below 5x10<SP>-12</SP> Pa<SP>-1</SP>. The in-plane retardation of front and oblique 40 DEG, and the retardation of the thickness direction measured at the photoelastic modulus of curing article of composition of below 10x10<SP>-12</SP> Pa<SP>-1</SP> and the thickness is 40 μ m are all below 5 nm.

Description

Active energy ray-curable composition for optical film formation, optical film, polarizer protective film, and polarizing plate

The present invention relates to an active energy ray-curable composition used for forming an optical film, an optical film obtained by curing the composition, and a polarizing plate using the film as a polarizer protective film, and belong to the technical fields.

In the present invention, the term "optical film" means "optical film or sheet", and the thickness is not particularly limited. Further, the acrylate or methacrylate means (meth) acrylate.

In recent years, with the increase in the size of liquid crystal displays, it has become necessary to increase the size of optical films such as retardation films that optically compensate for polarizer protective films or liquid crystals.

However, when the optical film is increased in size, the external force is unbalanced. Therefore, when the optical film is composed of a material which is liable to cause a change in birefringence due to an external force, the distribution of birefringence is generated, and the contrast is not Uniform problem. The easiness of the change in birefringence due to an external force is expressed by the absolute value of the photoelastic coefficient, but a triethylenesulfonated cellulose (hereinafter also referred to as "TAC") film generally used as a polarizing protective film is used. Because the absolute value of the photoelastic coefficient is large, the contraction of the polarizer causes the stress to refraction, which causes light leakage. Dew white.

Further, although the hysteresis of the TAC film with respect to the incident light in the front direction is small, it has a hysteresis in the thickness direction. These lags have had a significant impact on the viewing angle characteristics as the size of the liquid crystal display has advanced.

Therefore, a material which can coexist with a low photoelastic coefficient and a low retardation is sought.

Patent Document 1 discloses that the photoelasticity is reduced by blending an acrylic resin having a negative photoelasticity with respect to a cellulose ester resin having positive photoelasticity.

In Patent Document 2, a low photoelastic coefficient and a low hysteresis are coexisted by blending polyvinylpyrrolidone with respect to a cellulose ester resin.

Patent Document 3 discloses that an optical film containing a urethane (meth) acrylate has a small photoelastic coefficient.

Prior technical literature Patent literature

Patent Document 1 Japanese Re-publication Patent WO2009/081607

Patent Document 2 Japanese Patent Laid-Open Publication No. 2008-111056

Patent Document 3 Japanese Patent Laid-Open Publication No. 2011-145330

In the invention described in Patent Document 1, the hysteresis is large, and the low photoelastic coefficient and the low hysteresis cannot be coexisted. In addition, since cellulose having a high water absorption rate is used as a base, moisture heat resistance is not sufficient. When a polarizing plate using the film as a polarizer protective film is used under high temperature or high humidity, the polarizing plate is deformed. , or the disadvantage of lowering the performance of a polarizing plate such as a polarizing degree or a hue.

According to the invention described in Patent Document 2, since the combination of the cellulose ester resin and the polyvinylpyrrolidone has a problem that the composition described in Patent Document 1 is more resistant to moist heat resistance.

In the invention described in Patent Document 3, the absolute value of the photoelastic coefficient is equal to the TAC (13 × 10 ^-12 Pa ^-1 ), and it is not sufficient. Moreover, the hysteresis is large, and the low photoelastic coefficient and the low hysteresis cannot coexist.

As described above, the optical film which is used as a material for replacing the polarizer protective film of the conventional triacetyl cellulose, the low photoelastic coefficient and the low hysteresis cannot coexist, or even if they are coexistent, the moist heat resistance is insufficient. When the polarizing plate using the film as a polarizer protective film is used under high temperature or high humidity, the polarizing plate may be deformed or the performance of a polarizing plate such as a degree of polarization or a color tone may be lowered.

An object of the present invention is to provide an active energy ray-curable composition for forming an optical film, which has a low photoelastic coefficient and a low hysteresis, and an optical film excellent in moisture heat resistance can be obtained.

Further, an object of the present invention is to provide an optical film which can be suitably used for a polarizing mirror protective film, which is excellent in viewing angle characteristics and excellent in moist heat resistance and adhesion.

In order to solve the above-mentioned problems, the inventors of the present invention have found that the active energy ray-curable composition shown below can firstly solve the problem, and the present invention has been completed.

The active energy ray-curable composition for forming an optical film of the present invention, wherein the cured photo-elastic coefficient 1 of the cured product is 30 × 10 ^-12 Pa ^-1 or less of a urethane (meth) acrylate (A), and The photoelastic coefficient 2 having the following photoelastic coefficient 2 is 5 × 10 ^-12 Pa ^-1 or less, and the polymer (B) other than the component (A) is contained, and the following photoelastic coefficient 1 of the cured product of the composition is 10 × 10 ^-12 Pa ^-1 or less, when measured at a thickness of 40 μm, the front surface of the cured product and the in-plane retardation of 40° inclination and the hysteresis in the thickness direction are all 5 nm or less.

Further, the photoelastic coefficient 1 means a photoelastic coefficient at 23 ° C, and the photoelastic coefficient 2 is an optical film obtained by adding the component (B) at an arbitrary ratio to the component (A) used at 23 ° C. The value of the modulus of elasticity is the value when the amount of addition of the linear graph of the amount of addition and the photoelastic coefficient is 100%.

According to the present invention, there is provided an active energy ray-curable composition for forming an optical film which has a low photoelastic coefficient and a low hysteresis, and an optical film excellent in moist heat resistance can be obtained.

Moreover, according to the present invention, it is possible to provide an optical film which can be suitably used for a polarizing mirror protective film, has excellent viewing angle characteristics, and is excellent in moist heat resistance and adhesion.

[Formation of the Invention]

The active energy ray-curable composition for forming an optical film of the present invention (hereinafter simply referred to as "composition"), wherein the cured product has a photoelastic coefficient 1 of 30 × 10 ^-12 Pa ^-1 or less. (meth)acrylate (A) (hereinafter referred to as "(A) component"), and having a photoelastic coefficient 2 of 5 × 10 ^-12 Pa ^-1 or less, and containing the component (A) The polymer (B) (hereinafter referred to simply as "(B) component"], the following photoelastic coefficient 1 of the cured product of the composition is 10 × 10 ^-12 Pa ^-1 or less, and is measured at a thickness of 40 μm. The front surface of the cured product and the in-plane retardation at an inclination of 40° and the hysteresis in the thickness direction were all 5 nm or less.

In addition, the photoelastic coefficient 1 means the photoelastic coefficient at 23 ° C; the photoelastic coefficient 2 means the measurement relative to the component (A) used, The value of the photoelastic coefficient at 23 ° C of the optical film obtained by adding the component (B) at any ratio, and the value obtained by extrapolating the amount of the added amount and the linear modulus of the photoelastic coefficient to 100%.

The invention is described in detail below. Further, in the present specification, the crosslinked product and the cured product obtained by irradiating the composition with the active energy ray are summarized as "cured material".

1. (A) component

(A) A urethane (meth) acrylate having a photoelastic coefficient 1 of a cured product of the composition of 30 × 10 ^-12 Pa ^-1 or less.

The photoelastic coefficient 1 of the cured product as the component (A) is a compound of 30 × 10 ^-12 Pa ^-1 or less, and the photoelastic coefficient 1 of the cured product of the composition can be set to 10 × 10 ^-12 Pa ^{- 1} or less. Further, the photoelastic coefficient 1 of the cured product of the component (A) is preferably 5 × 10 ^-12 Pa ^-1 or more.

The photoelastic coefficient 1 of the cured product of the component (A) is preferably 10 × 10 ^-12 to 20 × 10 ^-12 Pa ^-1 , more preferably 10 × 10 ^-12 to 15 × 10 ^-12 Pa ^{- 1} .

In the present invention, the photoelastic coefficient is a coefficient indicating the easiness of occurrence of birefringence change due to an external force, and the photoelastic coefficient 1 is a photoelastic coefficient at 23 °C. The closer the value of the photoelastic coefficient is to zero, the smaller the change in the birefringence caused by the external force.

Specifically, the photoelastic coefficient 1 (C) is a value defined by the following formula (1) when σ is an extension stress and Δn is a birefringence when stress is added.

C[Pa ^-1 ]=△n/ σ ...(1)

Here, △ n is a refractive index n ₁ is set in the direction parallel to the extending direction; the vertical direction of the refractive index n ₂ to the extending direction of the line is defined by the following formula (2).

Δn=n ₁ -n ₂ (2)

Further, in the present invention, the photoelastic coefficient 1 is a value measured at a temperature of 23 °C.

In the method for measuring the photoelastic coefficient 1, it is preferred to measure the optical film which hardens the composition of the present invention or the film which only hardens the component (A) by a known complex refractometer. Specifically, for example, an optical film which hardens the composition of the present invention or a film which hardens only the component (A) is cut out to be 15 mm × 60 mm, and an automatic birefringence meter (KOBRA-WR, Prince Instruments Machine Co., Ltd.) is used. Co., Ltd.), each measuring the in-plane phase difference when the 5-point tension σ is changed from 0N to 10N at room temperature, and obtaining the photoelastic coefficient 1 from the inclination of the approximate straight line produced according to the formula (1) The method.

The component (A) may, for example, be a reactant of a polyol, an organic polyisocyanate or a hydroxyl group-containing (meth) acrylate, and the like may be selected so that the obtained compound satisfies the aforementioned photoelastic coefficient 1.

In the component (A), a urethane (meth) acrylate having two or more (meth) acrylonitrile groups is preferred, and more preferably two (meth) acrylonitrile groups are amine groups. Acid ester (meth) acrylate.

In the component (A), it is preferred that the urethane (meth) acrylate having no aromatic group is low in photoelasticity. A urethane (meth) acrylate having no aromatic group, a polyol as a raw material, and an organic polyisocyanate can be produced by using a compound having no aromatic group.

The weight average molecular weight (hereinafter referred to as "Mw") of the component (A) is preferably from 1,000 to 15,000, more preferably from 1,000 to 10,000.

Further, in the present invention, Mw means a value obtained by converting a molecular weight measured by gel permeation chromatography (hereinafter referred to as "GPC") into a polystyrene.

The component (A) may be used alone or in combination of two or more.

Hereinafter, a method of producing a polyol, an organic polyisocyanate, a hydroxyl group-containing (meth) acrylate, and a component (A) of the raw material compound of the component (A) will be described.

1-1. Polyol

In the case of a polyhydric alcohol, it is preferred to use a diol, and various diols can also be used.

Examples of the diol include an aliphatic diol having 2 to 12 carbon atoms, an alicyclic diol having 2 to 12 carbon atoms, a polycarbonate diol, a polyester diol, and a polyether diol.

Examples of the aliphatic diol having 2 to 12 carbon atoms include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,2-butanediol, and 1,3-butanediol. , 1,4-butanediol, polybutanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2 -ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 3,3-dimethylol heptane, 1,9-nonanediol and 2 -Methyl-1,8-octanediol and the like.

Examples of the alicyclic diol having 2 to 12 carbon atoms include cyclohexane dimethanol, hydrogenated bisphenol A, and tricyclo [5.2.1.0 ^2,6 ]decane dimethanol (general name; tricyclodecane II). Methanol), 1,4-decahydronaphthalenediol, 1,5-decahydronaphthalenediol, 1,6-decahydronaphthalenediol, 2,6-decahydronaphthalenediol, 2,7-decahydronaphthalene Glycol, decalin dimethanol, decanediol, carbopol dimethanol, decalin dimethanol, adamantane diol, 3,9-bis(1,1-dimethyl-2-hydroxyl) -2,4,8,10-tetraoxaspiro[5.5]undecane (general name; helical diol), isosorbide, isomannide, 2,2-bis (4-hydroxyl) Hexyl)propane (general name; hydrogenated bisphenol A), 4,4'-dihydroxydicyclohexylmethane (general name; hydrogenated bisphenol F), 1,1-bis(4-hydroxycyclohexyl)-1,1-di Cyclohexylmethane (commonly known as hydrogenated bisphenol Z) and cycloaliphatic diol such as 4,4-dicyclohexanol.

Examples of the polycarbonate diol include a low molecular weight diol or/and a polyether diol, a reaction product with a dialkyl carbonate such as ethylene carbonate or dibutyl carbonate, and the like.

Here, examples of the low molecular weight diol include ethylene glycol, propylene glycol, cyclohexane dimethanol, and 3-methyl-1,5-pentanediol, 1,5-pentanediol, 1,6-. Hexanediol and the like.

Examples of the polyether diol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutylene glycol; and block or random polymerization of polyethylene polypropylene oxide block polymer diols and the like. Glycols and the like.

Examples of the polyester diol include the low molecular weight diol or/and the polyether diol; and a basic acid such as adipic acid, succinic acid, tetrahydrofurfuric acid or hexahydrophthalic acid or an anhydride thereof. An esterification reactant such as an acid component.

Examples of the polyether diol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutanediol; and block or random polymerization of polyethylene polypropoxy block polymer diols and the like. Glycols and the like.

In the case of a polyhydric alcohol, since the mechanical strength of the cured product is increased, a triol may be used in combination with the diol.

Examples of the triol include 1,2,6-hexanetriol, 1,2,3-heptanetriol, 1,2,4-butanetriol, trimethylolpropane, and trimethylolethane. , xylitol, gallic phenol, glycerin and isocyanoic acid ginseng (2-hydroxyethyl) ester, and may include ε-caprolactone, ethylene oxide and propylene oxide of the triol Adults and so on.

The caprolactone adduct of triol is preferably a caprolactone adduct of trimethylolpropane or a caprolactone adduct of glycerol. The caprolactone adduct of the triol is preferably a compound having an average hydroxyl value of 300 to 600 mgKOH/g and an average number of hydroxyl groups of 3.

The caprolactone adduct of the above-mentioned triol is commercially available, and examples thereof include Plaxel 303, 305, 308, 312, and L320ML (manufactured by Daicel Chemical Industry Co., Ltd.).

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

As component (A), brittleness is required. In the case of flexibility, in the case of the polyol, it is more preferred to use an aliphatic diol having 2 to 12 carbon atoms or an alicyclic diol having 2 to 12 carbon atoms.

In the case where the mechanical properties are required as the component (A), more specifically, in the case where the breaking strength and the tensile modulus are required to be excellent, the amount which is the basis of the hydroxyl value of the polyol is preferably used. A polyol having an average molecular weight (hereinafter referred to as "P-Mn") of 500 or more and a polyol having a P-Mn of less than 500 are used in combination.

Further, in the present invention, the P-Mn (number average molecular weight) of the polyol means a value obtained according to the following formula.

More specifically, examples of the polyhydric alcohol having P-Mn500 or higher include a polycarbonate diol and a polyester diol, and examples of the polyhydric alcohol having a P-Mn of less than 500 include an aliphatic diol having 2 to 12 carbon atoms and An alicyclic diol having 2 to 12 carbon atoms is used in combination. The polyol having P-Mn of 500 or more is preferably a polyol having a P-Mn of 500 or more and 10,000 or more. Further, a polyol having a P-Mn of less than 500 is preferably a polyol having a P-Mn of 62 or more and less than 500.

1-2. Organic polyisocyanate

In the case of the organic polyisocyanate, an organic diisocyanate is preferred, and a non-yellowing organic diisocyanate is more preferred.

Examples of the non-yellowing type organic diisocyanate include hexamethylene diisocyanate, methyl diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and dimerization. Aliphatic diisocyanate such as acid diisocyanate, isophorone diisocyanate (hereinafter referred to as "IPDI"), 4,4'-methylenebis(cyclohexyl isocyanate), diisocyanate An alicyclic diisocyanate such as an alkyl ester or ω, ω'-diisocyanate dimethylcyclohexyl ester.

These organic polyisocyanates may be used alone or in combination of two or more.

Among the above compounds, IPDI is preferred from the viewpoint of excellent mechanical strength and optical properties of the cured product.

1-3. Hydroxyl-containing (meth) acrylate

Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. (hydroxy) hydroxypentyl acrylate, hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, tris, di or mono (meth) acrylate pentaerythritol, and di or mono (meth) acrylate A hydroxyalkyl (meth) acrylate such as trimethylolpropyl acrylate, and a caprolactone adduct of the compounds.

Among the above compounds, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and (methyl) are preferred from the viewpoints of excellent curability of the composition and flexibility of the cured product. A caprolactone adduct of 4-hydroxybutyl acrylate and 2-hydroxyethyl acrylate.

1-4. Method for producing (A) component

The component (A) is preferably one produced according to a usual method.

The component (A) is a compound which reacts a polyol and an organic polyisocyanate to produce an isocyanate group-containing compound, and reacts the compound with a hydroxyl group-containing (meth) acrylate (hereinafter referred to as "compound A1". The compound A1 is preferably a compound in which a polyol, an organic polyisocyanate, and a hydroxyl group-containing (meth) acrylate are simultaneously reacted (hereinafter referred to as "compound A2"), and the molecular weight is easily controlled.

In the case of the production of the compound A1, the polyol and the organic polyisocyanate to be used are heated and stirred in the presence of a urethane catalyst such as dibutyltin dilaurate, and an addition reaction is carried out to further add (methyl). The hydroxyalkyl acrylate is heated and stirred to carry out an addition reaction. In the case of producing the compound A2, a polyol, an organic polyisocyanate, and a (meth)acrylic acid are added in the presence of the same catalyst as described above. A hydroxyalkyl ester, a method of heating and stirring, and the like.

1-5. Preferred (A) component

In the present invention, the component (A) is preferably a polycarbonate diol or a polyester diol (hereinafter, referred to as "diol a" in the above), and has a carbon number of 2 to a carbamate of a 12 or more aliphatic or alicyclic diol (hereinafter referred to as "diol b"), a non-yellowing type organic diisocyanate, and a hydroxyl group-containing (meth) acrylate ( Methyl) acrylate.

The component (A) is used in comparison with other urethane (meth) acrylates by using diol a as a polyol, diol b as a short-chain diol, and yellowing as an organic diisocyanate. The type is excellent in mechanical strength, and the yellowing degree is small after the light resistance test, and further, it can be made that the cured product of the composition has a low photoelastic coefficient of 1.

Examples of the diol a include the above-mentioned polycarbonate diol and polyester diol. Examples of the diol b include the above aliphatic diol having 2 to 12 carbon atoms and a fat having 2 to 12 carbon atoms. Cyclohexane.

These diols a and b may be used alone or in combination of two or more.

In terms of the ratio of the diols a and b, it is preferably diol a; 5 to 50 mol% and diol b: 50 to 95 mol%, more preferably diol a: 5 to 40 mol% and Glycol b: 60 to 95 mol%.

Further, in the case of using a triol in combination, in terms of the ratio of the triol, it is preferably a total of the diols a and b: 50 to 95 mol% and a triol: 5 to 50 mol%, more preferably a diol a and / or b: 60 to 95 mol% and triol: 5 to 40 mol%.

In the same manner as described above, the diol a and the diol b are reacted with the non-yellowing-type organic diisocyanate to produce a compound containing an isocyanate group, and the compound is mixed with a hydroxyl group-containing (meth)acrylic acid. An ester-reacted compound (compound AI); a compound (compound A-II) in which a diol a and a diol b, a non-yellowing-type organic diisocyanate, and a hydroxyl group-containing (meth) acrylate are simultaneously reacted, etc., to facilitate The reason for controlling the molecular weight is preferably compound AI.

Further, in the present invention, in the case of the component (A), particularly preferred are the diol b (diol having a P-Mn of less than 500), the non-yellowing organic diisocyanate, and the hydroxyl group (A). The acrylate is a urethane (meth) acrylate of the reactant of the caprolactone adduct. The hardened material of the composition of the component (A) is brittle. It is excellent in softness.

In the case of the diol b in this case, a polyol having a P-Mn of 62 or more and 400 or less is preferable.

Specific examples of the compound are preferably an aliphatic diol having 2 to 6 carbon atoms such as 1,4-butanediol, a tricyclo[5.2.1.0 ^2,6 ]decane dimethanol, and 3,9. - an alicyclic diol having a plurality of rings, such as bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, to harden The point of excellent strength is particularly preferred as 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (general name) ; spiral diol).

In the case of a caprolactone adduct of a hydroxyl group-containing (meth) acrylate, a caprolactone adduct of a hydroxyalkyl (meth) acrylate is preferred. Further, as a reaction ratio with respect to the caprolactone of the hydroxyl group-containing (meth) acrylate, it is preferably larger than 0.1 mol and smaller than 2.0 mol.

The method for producing the component (A) is preferably carried out in the same manner as described above, and the preferred production method is also the same as described above.

2. (B) ingredients

The component (B) is a polymer having a photoelastic coefficient 2 of 5 × 10 ^-12 Pa ^-1 or less, and is a polymer other than the component (A). Further, the photoelastic coefficient 2 of the component (B) is preferably -15 × 10 ^-12 Pa ^-1 or more.

In the present invention, the photoelastic coefficient 2 means the value of the photoelastic coefficient at 23 ° C of the optical film obtained by adding the component (B) at an arbitrary ratio with respect to the component (A) used as described above, from the addition amount and light. The value of the linear factor extrapolation of the elastic coefficient is 100%.

When the relationship between the addition amount of the component (A) and the component (B) and the photoelastic coefficient is a straight line graph, it is preferable to obtain a measured value of three or more points, and it is preferable that the straight line chart is based on the least square method (least Squares method) to make.

Since the cured product of the component (A) or the cured product of the composition can be formed into a film, the photoelastic coefficient can be directly measured by using an automatic birefringence system, and the (B) component cannot directly measure the photoelastic coefficient due to film formation difficulties. The photoelastic coefficient 2 is set to the photoelastic coefficient.

As described above, the cured product of the component (A) has a positive photoelastic coefficient 1 of 30 × 10 ^-12 Pa ^-1 or less, preferably a positive range of 10 × 10 ^-12 to 30 × 10 ^-12 Pa ^-1 . 1 photoelastic coefficient, so by the deployment of a photoelastic coefficient of 2 5 × 10 ^-12 Pa ^-1 or less of component (B), but may be set photohardenable composition the coefficient of elasticity of the composition 2 was 10 × 10 ^-12 Pa ^{- 1} or less.

With respect to the photoelastic coefficient 2 of the component (B), it is preferably -10 × 10 ^-12 to 5 × 10 ^-12 Pa ^-1 , more preferably -10 × 10 ^-12 to 2 × 10 ^-12 Pa ^-1 More preferably, it is -10 x 10 ^-12 to -2 x 10 ^-12 Pa ^-1 .

The Mw of the component (B) is preferably set as appropriate, preferably from 1,000 to 100,000, more preferably from 1,000 to 50,000.

By making Mw 1,000 or more, the amount of the polymerization initiator or the chain transfer agent can be reduced when the component (B) is produced, whereby the photoelastic coefficient 1 of the cured product can be prevented from rising or coloring, and on the other hand, When it is 100,000 or less, it is excellent in the mutual solubility with the component (A), and the turbidity of the cured product can be prevented.

In the case of the component (B), as long as it is a polymer having the photoelastic coefficient 2, various compounds can be used, and examples thereof include a single polymer or copolymer of a monomer having a (meth)acryl fluorenyl group, and N- A vinyl-2-pyrrolidone copolymer, a single polymer or copolymer of α -methylstyrene, a vinyl-tetracyclododecene copolymer, or the like.

Specific examples of the monomer having a (meth) acrylonitrile group include (meth)acrylic acid; methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. , (butyl) (meth)acrylate, tertiary butyl (meth)acrylate, isomeric (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, (methyl) (meth) acrylate such as dicyclopentenyl acrylate, glycidyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (A) a hydroxyl group-containing (meth) acrylate such as hydroxybutyl acrylate or hydroxyhexyl (meth) acrylate; N-(meth) propylene hydrazino; and (meth) acrylamide, N - hydroxymethyl acrylamide, N,N-dimethyl(meth) acrylamide, N,N-diethyl(meth) acrylamide and N,N-dimethylaminopropyl ( Methyl) acrylamide such as acrylamide.

In the copolymer of a monomer having a (meth) acrylonitrile group, a copolymer having a decylamine structure or a carboxyl group has a large value of a photoelastic coefficient 2 of a large value and is excellent in mutual solubility with the component (A). Preferably.

In the copolymer having a guanamine structure, a morphine structure is preferred in terms of a guanamine structure. A specific example of the copolymer having a guanamine structure is preferably a copolymer of (meth) acrylate and N-(meth) acryloyl ruthenium.

In the case of the copolymer having a decylamine structure, the ratio of the monomer having a decylamine structure is preferably from 5 to 50 parts by weight based on 100 parts by weight of the total of all monomers used.

In a specific example of the copolymer having a carboxyl group, a copolymer of (meth) acrylate and acrylic acid or methacrylic acid is preferred.

In the case of a copolymer having a carboxyl group, it is preferably from 5 to 65 mgKOH/g in terms of acid value.

For the individual polymer or copolymer of the monomer having a (meth) acrylonitrile group, a commercially available product can be used. For example, Delpet 60N, 80N (made by Asahi Kasei Chemicals Co., Ltd.), Dainal BR52, BR80, BR83, BR85, BR87, BR88 (manufactured by Mitsubishi Rayon Co., Ltd.), KT75 (manufactured by Electric Chemical Industry Co., Ltd.), and the like can be mentioned.

Dainal is a copolymer having a (meth)acrylonitrile monomer, and BR83, BR87, and BR88 are commercially available as a copolymer of a carboxyl group.

Examples of the N-vinyl-2-pyrrolidone copolymer include a vinyl acetate, an alkyl (meth)acrylate, and the like.

Specific examples of the N-vinyl-2-pyrrolidone copolymer include vinylpyrrolidone. Vinyl acetate copolymer, vinyl pyrrolidone. Methyl (meth) acrylate copolymer, vinyl pyrrolidone. Ethyl (meth) acrylate copolymer, vinyl pyrrolidone. A (meth) butyl acrylate copolymer or the like.

As the N-vinyl-2-pyrrolidone copolymer, commercially available ones can also be used. For example, PVP/VA S-630 [ISP. Made by Japan Co., Ltd., etc.

The production method of the component (B) is not particularly limited, and any of the above-mentioned monomers may be used, and any of known methods such as suspension polymerization, emulsion polymerization, bulk polymerization, or solution polymerization may be used. Here, as the polymerization initiator, a usual peroxide-based or azo-based product can be used, and a redox system can be obtained.

The polymerization temperature is preferably 30 to 100 ° C in suspension or emulsion polymerization, and preferably 80 to 300 ° C in a bulk or solution polymerization. Further, polymerization can also be carried out using an alkyl mercaptan or the like as a chain transfer agent.

In the present invention, the component (B) is preferably a polymer having an ethylenically unsaturated group (hereinafter referred to as "(UB) component").

The (UB) component is chemically crosslinked with the component (A) by irradiation with an active energy ray. Therefore, in the case of formulating a polymer having a photoelastic coefficient 2 having no ethylenically unsaturated group as a negative value, there is a problem that the softness or brittleness of the obtained cured product is lowered, but a more photosynthetic coefficient can be formulated. 2 is a negative polymer, which can greatly reduce the photoelastic coefficient 2 of the hardened material.

The (UB) component is described below.

2-1. (UB) ingredients

Examples of the ethylenically unsaturated group in the (UB) component include a vinyl group, a vinyl ether group, a (meth) acrylonitrile group, and a (meth) acrylamide group. Among these, it is preferable that the component (B) is easily produced and the curability of the active energy ray is excellent, and it is particularly preferably a (meth) acrylonitrile group, more preferably an acryl oxime group.

In the case of the (UB) component, any compound having a photoelastic coefficient 2 of 5 × 10 ^-12 Pa ^-1 or less and having an ethylenically unsaturated group can be used, and examples thereof include the following polymer.

1) Polymer UB1: a polymer having a carboxyl group (hereinafter referred to as "carboxyl-containing prepolymer") and/or a polymer having a hydroxyl group (hereinafter referred to as "hydroxyl-containing prepolymer") A polymer obtained by adding a compound having an isocyanate group and an ethylenically unsaturated group (hereinafter referred to as "isocyanate-based unsaturated compound")

2) Polymer UB2: a polymer obtained by adding a compound having an epoxy group and an ethylenically unsaturated group (hereinafter referred to as "epoxy unsaturated compound") to a carboxyl group-containing prepolymer

3) Polymer UB3: a compound having a carboxyl group and an ethylenically unsaturated group in a polymer containing an epoxy group (hereinafter referred to as "epoxy group-containing prepolymer") (hereinafter referred to as " Polymer obtained from a carboxyl-based unsaturated compound")

The polymers UB1 to UB3 are explained below.

2-1-1. Method for producing prepolymer

The monomer constituting the prepolymer is preferably a monomer having a photoelastic coefficient 2 of 5 × 10 ^-12 Pa ^-1 or less, which is suitably selected, and a (meth) acrylonitrile group can be suitably used. Compound.

The method for producing a carboxyl group-containing prepolymer, a hydroxyl group-containing prepolymer, and an epoxy group-containing prepolymer will be described below.

2-1-1-1. Method for producing prepolymer containing carboxyl group

The carboxyl group-containing prepolymer used for the production of the polymer UB1 and the polymer UB2 may, for example, be a carboxyl group-unsaturated compound or an ethylenically unsaturated compound other than the compound (hereinafter referred to as "another unsaturated compound". The copolymer and the polymer having a carboxyl group at the terminal of the other unsaturated compound in the presence of a chain transfer agent having a carboxyl group (the terminal carboxyl group-containing polymer described below) and the like.

First, a copolymer of a carboxyl group-unsaturated compound and another unsaturated compound will be described.

Examples of the carboxyl group-unsaturated compound include (meth)acrylic acid, polycaprolactone denatured (meth)acrylic acid, and monohydroxyethyl phthalate (A). A carboxyl group-containing (meth) acrylate such as acrylate or succinic acid monohydroxyethyl (meth) acrylate.

Among these, in particular, since the photoelastic coefficient 2 of the obtained (UB) component is lower, (meth)acrylic acid is preferably used.

The other unsaturated compound is not particularly limited as long as the photoelastic coefficient 2 of the obtained (UB) component is 5 × 10 ^-12 Pa ^-1 or less, but is excellent in copolymerizability with the above carboxyl group-containing unsaturated compound. Therefore, a compound having a (meth) acrylonitrile group is preferred.

Examples of the compound having a (meth)acryl fluorenyl group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate. Base) butyl acrylate, (meth) acrylate a (meth) acrylate such as an ester, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate or glycidyl (meth) acrylate; N-(methyl)propenyl hydrazin; (meth) acrylamide, N-methylol acrylamide, N,N-dimethyl(meth) decylamine, N,N-di Ethyl (meth) acrylamide and acrylamide such as N,N-dimethylaminopropyl (meth) acrylamide; and (meth) acrylonitrile.

A compound other than the compound having a (meth) acrylonitrile group can be used as needed, and examples thereof include styrene, α-methylstyrene, and vinyl acetate.

Among these, in particular, since the photoelastic coefficient 2 of the obtained component (B) is lower, it is preferred to use methyl (meth)acrylate and N-(meth)acrylopyl rufolium.

In the prepolymer, a compound having a hydroxyl group and an ethylenically unsaturated group (hereinafter referred to as "hydroxyl-unsaturated compound") is further preferably copolymerized.

Examples of the hydroxy-based unsaturated compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyhexyl (meth)acrylate. A hydroxyl group-containing (meth) acrylate, a hydroxyalkyl vinyl ether such as hydroxybutyl vinyl ether, or the like.

The method for producing a copolymer of a carboxyl group-unsaturated compound and another unsaturated compound is not particularly limited, and a known method can be used, and the above compound can be used, and suspension polymerization, emulsion polymerization, bulk polymerization, and solution can be used. Aggregation, etc.

Among these, a point which is easy to manufacture a polymer and does not contain excessive impurities such as an emulsifier is preferably a solution polymerization method.

In the case of production by a solution polymerization method, a raw material monomer to be used is dissolved in an organic solvent, and a thermal polymerization initiator is added thereto, followed by heating and stirring. In the case of synthesizing by radical polymerization using a solution polymerization method, a raw material monomer to be used is dissolved in an organic solvent, and a thermal radical polymerization initiator is added thereto, followed by heating and stirring. Further, a chain transfer agent can be used as needed to adjust the molecular weight of the polymer.

Examples of the organic solvent used in the solution polymerization method include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate; and propylene glycol monomethyl ether. An ether; an aromatic hydrocarbon such as toluene or xylene; and an aliphatic hydrocarbon such as hexane, heptane or mineral spirit.

Examples of the thermal polymerization initiator include azo initiators such as azobisisobutyronitrile, azobisisovaleronitrile, azobiscyclohexanecarbonitrile, and azobiscyanoshikiic acid; and peroxygen trioxide Tert-butyl butyl acetate, tertiary hexyl peroxytrimethylacetate, dilauroyl peroxide, bis(2-ethylhexyl)peroxydicarbonate, di-tertiary butyl peroxide And an organic peroxide such as dicumyl peroxide; and hydrogen peroxide-iron (II) salt, peroxodisulfate-sodium hydrogen sulfite, diisopropylbenzene hydroperoxide-iron (II) Salt and so on.

The use ratio of the thermal polymerization initiator is preferably set in accordance with the molecular weight to be targeted. The use ratio of the thermal polymerization initiator is preferably from 0.1 to 10 parts by weight based on 100 parts by weight of the total of all monomers used.

The chain transfer agent may be used as needed in order to adjust to the above range of Mw, and since the photoelastic coefficient 2 of the component (B) is increased by the use of the chain transfer agent, it is preferable to Adjust the chain transfer agent in small amounts.

As the chain transfer agent, a well-known chain transfer agent can be used. For example, dodecyl mercaptan, lauryl mercaptan, epoxypropyl mercaptan, 2-hydrogen mercaptan, 3-hydrothiopropionic acid, hydrogen sulfuric acid, 2-ethylhexyl thioglycolate, 2, In addition to the thiol such as 3-dihydrothio-1-propanol, an α-methylstyrene dimer or the like can be mentioned.

These chain transfer agents may be used singly or in combination of two or more.

The use ratio of the chain transfer agent is preferably as large as the amount generally used, and is preferably from 0.01 to 7 parts by weight based on 100 parts by weight of the total monomers used.

The polymer obtained as described above is a polymer having a carboxyl group in a side chain.

The copolymerization ratio of the carboxyl group-unsaturated compound and the other unsaturated compound can be appropriately set in accordance with the ratio of the ethylenically unsaturated group to be finally introduced, and is 100 parts by weight based on the total amount of the carboxyl group-unsaturated compound and other unsaturated compound. It is preferably 1 to 40% by weight of a carboxyl group-unsaturated compound and 60 to 99% by weight of other unsaturated compound.

The Mw of the copolymer of the carboxyl group-unsaturated compound and the other unsaturated compound can be appropriately set according to the purpose, preferably from 1,000 to 100,000, more preferably from 1,000 to 50,000.

Next, a method for producing a polymer having a terminal carboxyl group will be described.

The method for producing a polymer having a terminal carboxyl group may, for example, be a method of polymerizing another unsaturated compound in the presence of a chain transfer agent having a carboxyl group.

The other unsaturated compound may, for example, be the same as the above, and is preferably the same as the above.

Examples of the chain transfer agent having a carboxyl group include 3-hydrothiopropionic acid, hydrogen sulfuric acid, and the like.

The ratio of the chain transfer agent having a carboxyl group can be appropriately set in accordance with the ratio of the ethylenically unsaturated group to be finally introduced, and is preferably from 0.01 to 7 parts by weight based on 100 parts by total of the total monomers used.

In the case of the polymerization method, the same method as described above can be employed.

The polymer obtained as described above is a polymer having a carboxyl group at the terminal.

The Mw of the terminal carboxyl group-containing polymer can be appropriately set according to the purpose, preferably from 1,000 to 100,000, more preferably from 10,000 to 50,000.

In the case of the carboxyl group-containing prepolymer, since the number and position of the ethylenically unsaturated group introduced into one molecule can be controlled, it is preferably a terminal carboxyl group-containing polymer.

2-1-1-2. Method for producing hydroxyl group-containing prepolymer

The hydroxyl group-containing prepolymer used in the polymer UB1 may be a polymerizable other unsaturated compound in the presence of a copolymer of a hydroxy unsaturated compound and another unsaturated compound and a chain transfer agent having a hydroxyl group. A polymer having a hydroxyl group at the terminal (hereinafter referred to as "a polymer having a terminal hydroxyl group").

Examples of the hydroxy-based unsaturated compound include the same compounds as described above.

The other unsaturated compound may, for example, be the same as the above, and is preferably the same as the above.

The method for producing a copolymer of a hydroxy-based unsaturated compound and another unsaturated compound can be produced in the same manner as described above.

The copolymer obtained as described above is a copolymer having a hydroxyl group in a side chain.

The copolymerization ratio of the hydroxy-based unsaturated compound and the other unsaturated compound can be appropriately set in accordance with the ratio of the ethylenically unsaturated group to be finally introduced, and the total amount of the hydroxy-based unsaturated compound and the other unsaturated compound is 100% by weight. It is 1 to 40% by weight of a hydroxy-based unsaturated compound and 60 to 99% by weight of other unsaturated compound.

The Mw of the copolymer of the hydroxy-based unsaturated compound and the other unsaturated compound can be appropriately set according to the purpose, preferably from 1,000 to 100,000, more preferably from 1,000 to 50,000.

Next, a method for producing a hydroxyl group-containing polymer will be described.

The method for producing a hydroxyl group-containing polymer may, for example, be a method of polymerizing another unsaturated compound in the presence of a chain transfer agent having a hydroxyl group.

The other unsaturated compound may, for example, be the same as the above, and is preferably the same as the above.

Examples of the chain transfer agent having a hydroxyl group include 2-hydrogenthioethanol and the like.

The ratio of the chain transfer agent having a hydroxyl group can be appropriately set in accordance with the ratio of the ethylenically unsaturated group to be finally introduced, and is preferably from 0.01 to 7 parts by weight based on 100 parts by weight of the total of all monomers used.

In the case of the polymerization method, the same method as described above can be employed.

The polymer obtained as described above has a polymer having a hydroxyl group at its terminal.

The Mw of the terminal hydroxyl group-containing polymer can be appropriately set according to the purpose, preferably from 1,000 to 100,000, more preferably from 1,000 to 50,000.

In the case of the hydroxyl group-containing prepolymer, a hydroxyl group-containing polymer is preferred because the number and position of the ethylenically unsaturated groups introduced into one molecule can be controlled.

2-1-1-3. Method for producing epoxy group-containing prepolymer

The epoxy group-containing prepolymer used in the polymer UB3 may, for example, be a copolymer of an epoxy-based unsaturated compound and another unsaturated compound.

Examples of the epoxy-based unsaturated compound include an epoxy group-containing (meth) acrylate such as (meth)acrylic acid propylene acrylate and an epoxycyclohexene-containing (meth) acrylate.

The other unsaturated compound may, for example, be the same as the above, and is preferably the same as the above.

The method for producing a copolymer of an epoxy-based unsaturated compound and another unsaturated compound can be produced in the same manner as described above.

The copolymer obtained as described above has a copolymer having an epoxy group in its side chain.

The copolymerization ratio of the epoxy-based unsaturated compound and the other unsaturated compound can be appropriately set in accordance with the ratio of the ethylenically unsaturated group to be finally introduced, and the total amount of the epoxy-based unsaturated compound and other unsaturated compounds is 100. The weight is from 1 to 40% by weight of the epoxy-based unsaturated compound and from 60 to 99% by weight of the other unsaturated compound.

The Mw of the copolymer of the epoxy-based unsaturated compound and the other unsaturated compound can be appropriately set according to the purpose, preferably from 1,000 to 100,000, more preferably from 1,000 to 50,000.

2-1-2. (UB) component manufacturing method

The (UB) component is a functional group reactive with the prepolymer and having ethylenic unsaturation with respect to the carboxyl group-containing prepolymer, the hydroxyl group-containing prepolymer, and the epoxy group-containing prepolymer. The compound of the group is introduced by an addition reaction.

In the case of the addition reaction, it can be carried out in accordance with a usual method.

For example, even in any case, in an organic solvent, each compound is added to the prepolymer by an aqueous medium or without a solvent. In terms of the conditions of the respective addition reactions, it is preferred to select the reaction temperature, the reaction time, and the catalyst in response to each reaction.

The addition reaction is described below.

The polymer UB1 is produced by adding an isocyanate-based unsaturated compound to a carboxyl group-containing prepolymer and/or a hydroxyl group-containing prepolymer by an urethanization reaction.

The isocyanate-based unsaturated compound may, for example, be an organic polyisocyanate exemplified by the production of the component (A), and examples thereof include 2-isocyanate ethyl (meth)acrylate, IPDI and 2-hydroxyethyl. A one-component adduct of a acrylate or the like.

The catalyst for the urethanization reaction may, for example, be an organometallic compound.

Examples of the organometallic compound include di-n-butyltin oxide, di-n-butyltin dilaurate, di-n-butyltin, di-n-butyltin diacetate, di-n-octyl oxide, and dilauric acid. - an organotin compound such as n-octyl tin, monobutyltin trichloride, di-n-butyltin dialkyl mercaptan or di-n-octane dialkyl mercaptan; lead oleate, lead 2-ethylhexanoate, An organic lead compound such as naphthenic acid lead or lead octenoate; an organic antimony compound such as bismuth octoate or the like.

The ratio of the catalyst used in the urethanation reaction is preferably 0.001 to 0.5 parts by weight, more preferably 0.001, based on 100 parts by weight of the total of the carboxyl group-containing prepolymer and the isocyanate-based unsaturated compound. To 0.1 parts by weight.

The reaction ratio with respect to the isocyanate-based unsaturated compound of the carboxyl group-containing prepolymer is preferably 1 mol, more preferably 0.8 to 1.0 mol% of the isocyanate-based unsaturated compound, based on the carboxyl group in the carboxyl group-containing prepolymer.

The reaction ratio with respect to the isocyanate-based unsaturated compound of the hydroxyl group-containing prepolymer is preferably 1 mol with respect to the hydroxyl group in the hydroxyl group-containing prepolymer, and the isocyanate unsaturated compound is 0.8 to 1.0 mol. ear.

By setting the reaction ratio of the isocyanate-based unsaturated compound to less than 1 mol with respect to the carboxyl group or/and the hydroxyl group 1 molar in the prepolymer, and forming the (UB) component into a polymer having a carboxyl group and/or a hydroxyl group. .

The polymer B2 is produced by adding an epoxy-based unsaturated compound to a carboxyl group-containing prepolymer.

Further, the polymer B3 is produced by adding a carboxyl group-containing unsaturated polymer to an epoxy group-containing prepolymer.

The epoxy-based unsaturated compound may be the same as the above, and the carboxyl-based unsaturated compound may be the same as the above.

Examples of the catalyst for the addition reaction of a carboxyl group and an epoxy group include tertiary esters such as triethylamine, tripropylamine, tributylamine, dimethyllaurylamine, triethylenediamine, and tetramethylethylenediamine. Amine; a quaternary ammonium salt such as triethylbenzylammonium chloride, trimethylhexadecane bromide or tetrabutylammonium bromide; tetraphenylphosphonium bromide and tetrabutylphosphonium bromide; a salt; and a phosphine compound such as triphenylphosphine and tributylphosphine. Among these, from the viewpoint of less coloration of the resin, it is preferred to use triphenylphosphine.

The ratio of the catalyst in the reaction is 100 parts by weight based on the total amount of the carboxyl group-containing prepolymer and the epoxy-based unsaturated compound, or relative to the epoxy group-containing prepolymer and the carboxyl group-containing unsaturated compound. The total amount is 100 parts by weight, preferably 0.1 to 5.0 parts by weight, more preferably 0.1 to 3.0 parts by weight.

The reaction ratio of the epoxy-based unsaturated compound to the carboxyl group-containing prepolymer is preferably 1 mol, preferably 0.8 to 1.2 mol, based on the carboxyl group in the carboxyl group-containing prepolymer. Saturated compound.

The molar ratio of the epoxy group to the epoxy group-containing prepolymer is 1 mole, preferably a carboxyl group unsaturated compound, relative to the reaction ratio of the carboxyl group-containing unsaturated compound of the epoxy group-containing prepolymer. 0.8 to 1.2 m.

In the above-mentioned addition reaction, the production of the prepolymer is continued in any case, preferably after the subsequent solution polymerization.

At this time, a polymerization inhibitor was used to suppress polymerization at the time of the addition reaction. The polymerization inhibitor may, for example, be dibutylhydroxytoluene, hydroquinone or hydroquinone monomethyl ether, and is preferably added in an amount of 50 to 1,000 ppm with respect to the reaction solution.

2-3. Ethyl unsaturated group in (UB) component

The average number of ethylenically unsaturated groups in the (UB) component is preferably set as appropriate according to the purpose.

The average number of ethylenically unsaturated groups in the (UB) component is preferably from 0.5 to 5.0, more preferably from 1.0 to 3.0 on average. When the number of ethylenically unsaturated groups in one molecule is 0.5 or more on average, it is sufficiently assembled in the matrix of the component (A), and is resistant to heat and humidity. Brittleness is sufficient. When the average value is 5.0 or less, the crosslinking density is moderate, and the toughness of the film is excellent, and the photoelastic coefficient 1 of the cured product of the composition can also be lowered.

The average number (f) of the ethylenically unsaturated groups in the (UB) component can be represented by the following formula (3).

X: number average molecular weight Mn of prepolymer measured by GPC

Y: molecular weight of a compound unit having a reactive group in the prepolymer

Z: parts by weight of the compound unit having a reactive group in the prepolymer

Further, the compound unit having a reactive group in the prepolymer means a monomer unit derived from a carboxyl group-containing unsaturated compound as long as it is a carboxyl group-containing prepolymer; and is a hydroxyl group as long as it is a hydroxyl group-containing prepolymer. A monomer unit which is an unsaturated compound; and a monomer unit derived from an epoxy-based unsaturated compound as long as it is an epoxy group-containing prepolymer.

In the case of the (UB) component, since an ethylenically unsaturated group can be introduced efficiently at the molecular end, it is preferable to use a prepolymer as a prepolymer in which high brittleness and photoelastic coefficient 2 can coexist. A polymer produced by a carboxyl group-containing polymer or a terminal hydroxyl group-containing polymer (hereinafter referred to as a macromonomer).

The macromonomers include, in particular, polymers B1 and B2 produced from a terminal carboxyl group-containing polymer, and a polymer B1 produced from a terminal hydroxyl group-containing polymer, and these f values are 1.0.

3. Active energy ray-curable composition for optical film formation

The present invention is an active energy ray-curable composition for forming an optical film containing the component (A) and the component (B) as essential components.

In the method for producing the composition, it is preferred to use the component (A) and the component (B) in accordance with a usual method, and further use other components as needed, and to stir them. Mixed.

In the composition of the present invention, it is necessary to make the photoelastic coefficient 1 of the cured product 10 × 10 ^-12 Pa ^-1 or less. As a result, it is difficult to cause a change in birefringence due to an external force of the cured product, and it is possible to prevent light leakage or whitening when used as a polarizer protective film. Further, the photoelastic coefficient 1 of the cured product of the composition of the present invention is preferably -10 × 10 ^-12 Pa ^-1 or more.

When the composition of the present invention is measured at a thickness of 40 μm, it is necessary that the front surface of the cured product and the in-plane retardation at an inclination of 40° and the hysteresis in the thickness direction are 5 nm or less. Thereby, in the case of using a protective film as a polarizer, a liquid crystal display excellent in viewing angle characteristics can be obtained. When the hysteresis of the cured product is larger than 5 nm, there is a problem that the viewing angle characteristics are deteriorated.

Further, in the case of measuring at a thickness of 40 μm, the in-plane retardation of the front surface of the cured product is 1 nm or less, the in-plane retardation at an inclination of 40° is 5 nm or less, and the retardation in the thickness direction is preferably 5 nm or less. Further, the value of the hysteresis is preferably -5 nm or more.

The hysteresis in the present invention means the phase difference due to birefringence when the linearly polarized light is incident on the optical film and the transmitted light is decomposed into two orthogonal linear polarizations.

Specifically, the in-plane hysteresis (Re) and the thickness direction hysteresis (Rth) are such that the main refractive index in the plane of the film is nx, ny (but nx≧ny), the refractive index in the thickness direction is nz, and the film thickness is When it is d, it is the value defined by the following formula.

Re=(nx-ny)×d

Rth={(nx+ny)/2-nz}×d

Further, in the present invention, the in-plane retardation inclined by 40° means the in-plane retardation when the linearly polarized light is incident at an inclination of 40° with respect to the optical film.

The ratio of the component (A) and the component (B) can be appropriately set according to the purpose, and it is preferably 30 to 90% by weight of the component (A) based on the total amount of the component (A) and the component (B). And 10 to 70% by weight of the component (B), more preferably 40 to 80% by weight of the component (A) and 20 to 60% by weight of the component (B).

When the ratio of the component (A) is 30% by weight or more, the obtained cured product can be excellent in mechanical properties, and the low photoelastic coefficient can be obtained by setting it to 90% by weight or less. Low hysteresis coexists.

In the composition of the present invention, the component (A) and the component (B) are essential, and various components can be formulated according to the purpose.

Specifically, an ethylenically unsaturated compound (hereinafter referred to as (C) component), a photopolymerization initiator (hereinafter referred to as component (D)), and an organic solvent (hereinafter referred to as (E)) other than the component (A) may be mentioned. Ingredients], polymerization inhibitors or/and antioxidants, light resistance improvers, and the like.

These components are described below.

(C) component

The component (C) is an ethylenically unsaturated compound other than the component (A).

The component (C) is a component which can be blended as needed for the purpose of lowering the viscosity of the entire composition or adjusting other physical properties.

Specific examples of the component (C) include (meth)acrylates other than the component (A) (hereinafter referred to as "other (meth)acrylates") or N-vinyl-2-pyrrolidines. Ketones, etc.

Examples of the other (meth) acrylate include a compound having one (meth) acrylonitrile group (hereinafter referred to as "monofunctional (meth) acrylate)] or two or more (A) A compound of an acrylonitrile group (hereinafter referred to as "polyfunctional (meth) acrylate") or the like.

Specific examples of the monofunctional (meth) acrylate include (meth)acrylic acid Ester, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, cyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, (meth)acrylic acid- 1-adamantyl ester, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, (a) Base) butyl acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl methacrylate, (methyl) ) tetrahydrofurfuryl acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, benzyl (meth) acrylate , allyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, o-phenol EO denatured (n = 1 to 4) (methyl) Acrylate, p-cumylphenol EO denatured (n=1 to 4) (meth) acrylate, phenyl (meth) acrylate, (o) phenyl phenyl (meth) acrylate, (meth) acrylate P-cumenyl phenyl ester, N-(methyl) propylene decyl porphyrin, N-vinyl carbamide, N-(A) Base) acryloyloxyethylhexahydrophthalimide, N-(methyl)propenyloxyethyltetrahydrophthalimide, and the like.

Specific examples of the polyfunctional (meth) acrylate include bisphenol A EO denatured (n = 1 to 2) di(meth) acrylate, di(meth) acrylate bisphenol A ester, and Ethylene glycol methacrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol ( n=5 to 14) di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, di(meth)acrylic acid Propylene glycol ester, polypropylene glycol (n=5 to 14) di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, Polybutylene glycol (n=3 to 16) di(meth)acrylate, poly(1-methylbutanediol) (n=5 to 20) di(meth)acrylate, di(meth)acrylic acid -1,6- Hexanediol ester, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate hydroxytrimethylacetate, A difunctional ester of tricyclodecane dimethylol (meth)acrylate or the like.

Further, in the above, EO denaturation means the meaning of ethylene oxide denaturation, and n means the repeat number of alkylene oxide units.

In the case of the component (C), only one type of the above compounds may be used, or two or more types may be used in combination.

In the case of the component (C), among the above compounds, a compound having a photoelastic coefficient 1 of a homopolymer of less than the component (A) is preferred, and a photoelastic coefficient 1 of the homopolymer is preferably a negative. Compound.

In the specific example of the compound, it is particularly preferred to be (meth)acrylic acid. Ester, tert-butyl (meth)acrylate, N-(methyl)propenyl rufofen and N-vinyl-2-pyrrolidone.

The ratio of the component (C) may be appropriately set according to the purpose, and may be any amount as long as it does not lower the flexibility of the obtained cured product, and is preferably 100 by weight with respect to the total amount of the component (A) and the component (B). The fraction is from 1 to 100% by weight, more preferably from 1 to 80% by weight.

(D) component

The component (D) is a photopolymerization initiator.

The component (D) is a blending component in the case where ultraviolet rays and visible light are used as active energy rays. In the case where an electron beam is used as the active energy ray, it is not necessary to mix the component (D), but for the improvement of the sclerosing property, the component (D) may be formulated in a small amount as needed.

Examples of the component (D) include benzyldimethylketal, benzyl, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl benzophenone, 2-hydroxy-2- Methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, oligo[2 -hydroxy-2-methyl-1-[4-1-(methylethene)phenyl]acetone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropenyl) Benzyl]phenyl}-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)]phenyl]-2-morpholinopropan-1-one, 2- Benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1- (4-morpholin-4-yl-phenyl)butan-1-one, Adeca Optomer N-1414 (made by Adeka Co., Ltd.), methyl phenylglyoxylate, ethyl hydrazine, phenanthrenequinone, etc. Aromatic ketone compounds; benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenyl Benzophenone, 4-(methylphenylthio)phenylphenylmethane, methyl-2-benzophenone, 1-[4-(4-benzylphenylsulfo)phenyl]-2-methyl 2-(4-methylphenylsulfonyl)propan-1-one, 4, 4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, N,N'-tetramethyl-4,4'-diaminodi a benzophenone compound such as benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, and 4-methoxy-4'-dimethylaminobenzophenone; oxidation Bis(2,4,6-trimethylbenzyl)phenylphosphine, 2,4,6-trimethylbenzyldiphenylphosphine oxide, ethyl(2,4,6-trimethylbenzyl)phenyl Hypophosphite and oxidized decylphosphine compound such as bis(2,6-dimethoxybenzyl)-2,4,4-trimethylpentanephosphine; 9-oxosulfur 2-chloro-9-oxosulfur 2,4-diethyl-9-oxosulfur Isopropyl-9-oxygen sulfide 1-chloro-4-propyl-9-oxosulfur , 3-[3,4-dimethyl-9-sideoxy-9H-9-oxygen chloride -2-yl]oxy]-2-hydroxypropyl-N,N,N-trimethylammonium and fluorine 9-oxosulfur 9-oxosulfur a compound; an acridone compound such as acridone or 10-butyl-2-chloroacridone; 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzyl) And ketone esters of ethyl ketone 1-[9-ethyl-6-(2-methylbenzyl)-9H-indazol-3-yl]-1-(O-ethylindenyl) 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-phenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyl) Phenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer and 2-(2,4-dimethoxy 2,4,5-triarylimidazole dimer such as phenyl)-4,5-diphenylimidazole dimer; and 9-phenyl acridine and 1,7-bis(9,9'-fluorene An acridine derivative such as pyridyl)heptane or the like.

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

The blending ratio of the component (D) is 100 parts by weight based on the total of the components (A) and (B), and in the case of containing the component (C), the component (B) and the component (B) are The total amount of the component (C) is 100 parts by weight, preferably 0.01 to 10% by weight, more preferably 0.1 to 5% by weight.

When the compounding ratio of the component (D) is 0.01% by weight or more, the composition can be cured by an appropriate amount of ultraviolet rays or visible light, and productivity can be improved. On the other hand, when it is 10% by weight or less, it can be made. It is excellent in weather resistance or transparency of a cured product.

(E) component

The composition of the present invention is preferably an organic solvent containing the component (E) for the purpose of improving the coating property to the substrate or the like.

Specific examples of the component (E) include hydrocarbon solvents such as n-hexane, benzene, toluene, xylene, ethylbenzene, and cyclohexane; methanol, ethanol, 1-propanol, and 2-propanol; 1-butanol, 2-butanol, isobutanol, 2-methoxyethanol, 2-ethoxyethanol, 2-(methoxymethoxy)ethanol, 2-isopropyloxyethanol, 2-butyl Oxyethanol, 2-isopentyloxyethanol, 2-hexyloxyethanol, 2-phenoxyethanol, 2-benzyloxyethanol, decyl alcohol, tetrahydrofurfuryl alcohol, diethylene glycol, diethylene glycol monomethyl ether An alcohol solvent such as diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol or propylene glycol monomethyl ether; tetrahydrofuran, two Alkane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, bis(2-methoxyethyl) ether, bis(2-ethoxyethyl) ether and double (2- An ether solvent such as butoxyethyl)ether; acetone, methyl ethyl ketone, methyl-n-acetone, diethyl ketone, butyl ketone, methyl isobutyl ketone, methyl amyl ketone, di-n-acetone, Ketone solvents such as diisobutyl ketone, phorone, isophorone, cyclopentanone, cyclohexanone and methylcyclohexanone; ethyl acetate, butyl acetate, isobutyl acetate, acetic acid An ester solvent such as methyl glycol ester, propylene glycol monomethyl ether acetate or cellosolve acetate; N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl hydrazine, An aprotic polar solvent such as N-methyl-2-pyrrolidone or γ-butyrolactone.

In the component (E), one or more of the above compounds may be used.

In the case of an organic solvent, it may be added in other ways, and the organic solvent used in the production of the component (A) may be used as it is without isolation.

In terms of the ratio of the component (E), although it can be suitably set, it is preferably from 10 to 90% by weight, more preferably from 40 to 80% by weight in the composition.

Polymerization inhibitor or / and antioxidant

In the composition of the present invention, a polymerization inhibitor or/and an antioxidant is added, and the storage stability of the composition of the present invention can be improved, which is preferable.

In terms of a polymerization inhibitor, preferred are hydroquinone, hydroquinone monomethyl ether, 2,6-di-tertiary butyl-4-cresol, and various phenolic antioxidants, and sulfur-based auxiliary may be added. A secondary antioxidant, a phosphorus-based antioxidant, and the like.

The total blending ratio of the polymerization inhibitor or/and the antioxidant is 100 parts by weight based on the total of the components (A) and (B), and in the case of containing the component (C), relative to the component (A), The total amount of the component B and the component (C) is 100 parts by weight, preferably 0.001 to 3% by weight, more preferably 0.01 to 0.5% by weight.

Light resistance improver

A light resistance improving agent such as an ultraviolet absorber or a light stabilizer may be added to the composition of the present invention.

Examples of the ultraviolet absorber include 2-(2'-hydroxy-5-methylphenyl)benzotriazole and 2-(2'-hydroxy-3',5'-di-tertiary butylbenzene. a benzotriazole compound such as benzotriazole, 2-(2'-hydroxy-3'-tertiarybutyl-5'-methylphenyl)benzotriazole; 2,4-bis(2) ,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-s-three Three Compound; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2,2'-di Hydroxy-4-methoxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,3,4,4'-four a benzophenone compound such as hydroxybenzophenone, 2,3', 4,4'-tetrahydroxybenzophenone or 2,2'-dihydroxy-4,4'-dimethoxybenzophenone.

In the case of a photostabilizer, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dimethylhydrazine hexamethylenediamine can be cited. , bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-2-(3,5-di-tri-butyl-4-hydroxybenzyl)-2-n-butyl a low molecular weight hindered amine compound such as malonate or bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate; N,N'-bis (2,2, 6,6-Tetramethyl-4-piperidinyl)-N,N'-dimethylhydrazine hexamethylenediamine, bis(1,2,2,6,6-pentamethyl-4-piperidine A hindered amine light stabilizer such as a high molecular weight hindered amine compound such as a sebacate.

The blending ratio of the light resistance improving agent is 100 parts by weight based on the total of the components (A) and (B), and in the case of containing the component (C), the component (A), the component (B), and (C) The total amount of the components is 100 parts by weight, preferably 0 to 5% by weight, more preferably 0 to 1% by weight.

4. How to use

The composition of the present invention can be used in various ways depending on the purpose of forming the optical film.

Specifically, a method in which a coating film composition is cured on a substrate by irradiation with an active energy ray; a method in which a composition is coated on a substrate, bonded to another substrate, and further irradiated with an active energy ray to be hardened; The composition is poured into a mold having a concave portion, a method of hardening by irradiation with an active energy ray, and the like.

As the substrate, any of a peelable substrate and a substrate having no mold release property (hereinafter referred to as "non-release substrate") can be used.

Examples of the peelable substrate include a release-treated film and a release-treated surface untreated film (hereinafter referred to as "release material").

Examples of the release material include polyoxyethylene phthalate film, surface untreated polyethylene phthalate film, surface untreated cycloolefin polymer film, and surface untreated OPP film (polypropylene). Wait.

In order to suppress the haze of the cured product of the present invention to 1.0% or less, it is preferred to use a surface untreated polyethylene terephthalate film or a surface untreated OPP film (polypropylene).

The optical film obtained from the composition of the present invention is preferably a substrate having a surface roughness (center line average roughness) Ra of 150 nm or less as a peelable substrate in order to achieve a low haze value or to provide surface smoothness. More preferably, the substrate has a Ra of 1 to 100 nm. Further, in terms of the haze value, it is preferably 3.0% or less. Further, the haze value is preferably 0.01% or more.

Specific examples of the substrate include a surface untreated polyethylene terephthalate film or a surface untreated OPP film (polypropylene).

Further, in the present invention, the surface roughness Ra means the measurement of the unevenness on the surface of the film, and the average thickness is calculated.

Examples of the non-releasable substrate include various types of plastics other than the above, and examples thereof include cellulose acetate resins such as polyvinyl alcohol, triethyl fluorenyl cellulose and diethyl fluorenyl cellulose, and acrylic resins. A cyclic olefin such as a polyester, a polycarbonate, a polyarylate, a polyether oxime or a norbornene is used as a monomeric cyclic polyolefin resin.

In the case of coating a film of the composition of the present invention, in terms of a composition, the obtained optical film is made to prevent foreign matter from entering or preventing voids and the like. Occurs or makes it an excellent optical property, so it is preferred to stir the raw material components. After mixing, the purified product is used.

In terms of the method of purifying the composition, it is preferred to use a method of filtering the composition. Examples of the filtration method include pressure filtration and the like.

The filtration accuracy is preferably 10 μm or less, more preferably 5 μm or less. The smaller the filtration accuracy, the better, but when it is too small, the filter is clogging, and the productivity is lowered by increasing the exchange frequency of the filter, so the lower limit is preferably 0.1 μm.

The coating method may be appropriately set according to the purpose, and examples thereof include a previously known bar coating, an applicator, a doctor bale, a knife coater, a comma coater, and a reverse roll. A method of coating a coating film such as a coater, a die coater, a lip coater, a gravure coater, and a micro gravure coater.

Examples of the active energy ray include an electron beam, ultraviolet rays, visible light, and the like. In these, it is not necessary to mix a photoinitiator, and it is more preferable that it is an electron beam from the viewpoint of the heat resistance and light resistance of a hardened material.

In the active energy ray irradiation, the irradiation conditions such as the amount of the wire or the irradiation intensity can be appropriately set depending on the composition, the substrate, the purpose, and the like to be used.

5. Optical film

The composition of the present invention can be suitably used in the production of an optical film.

The optical film will be described below.

In addition, some of them are described below based on the first and second drawings.

5-1. Method of manufacturing optical film

The method for producing an optical film may be carried out according to a usual method. For example, the composition may be applied to a substrate and then irradiated with an active energy ray to produce.

Fig. 1 is a view showing an example of a preferred method for producing an optical film composed of a release material/cured material.

Figure 1 (1) refers to the meaning of the release material.

In the case where the composition is a solventless type (Fig. 1 : F1), the composition is coated on a release material [Fig. 1 (1)]. When the composition contains an organic solvent or the like (Fig. 1 : F2), the composition is coated on a release material [Fig. 1 (1)], dried, and the organic solvent or the like is evaporated (Fig. 1). :1-1).

The optical energy film including the release material/cured material can be obtained by irradiating the active energy ray with respect to the sheet formed with the composition layer (2) on the release material. The irradiation of the active energy ray is usually performed from the side of the composition layer, but may be irradiated from the side of the release material.

In the above, when a release material is used as the substrate (1), an optical film containing a release material/cured material can be produced.

The coating film amount of the composition of the present invention is preferably selected depending on the use for use, but it is preferably applied to a film thickness of 5 to 200 μm after drying the organic solvent or the like, more preferably 10 to 100 μm.

In the case where the composition contains an organic solvent or the like, it is heated after coating. Dry and evaporate the organic solvent and the like.

To heat. The drying method can be carried out by means of a furnace having a heating device or by blowing air.

heating. The drying conditions can be appropriately set depending on the organic solvent to be used, and the like, and a method of heating to a temperature of 40 to 150 ° C can be mentioned.

To heat. In the composition after drying, the ratio of the organic solvent is preferably 1% by weight or less.

In the active energy ray irradiation, the irradiation conditions such as the amount of the wire or the irradiation intensity may be appropriately set depending on the composition, the substrate, the purpose, and the like to be used.

Fig. 2 is a schematic view showing an example of a preferred production method of an optical film comprising a release material/cured material/release material.

In Fig. 2, (1), (3), and (4) mean the release material.

In the case where the composition is a solventless type (Fig. 2: F1), the composition is coated on a release material [Fig. 2: (1)]. When the composition contains an organic solvent or the like (Fig. 2: F2), the composition is coated on a release material [Fig. 2: (1)], dried, and the organic solvent is evaporated (Fig. 2: 2-1). In the composition layer (2), after laminating the release material (3), irradiating the active energy ray or irradiating the active energy ray, the optical film is obtained by laminating the release material (4), and the system is obtained. The release material, the cured product, and the release material are formed in this order.

In the above-described first and second drawings, an example in which a release material is used as a substrate is described, and an optical film can be produced using a non-release substrate.

For example, in Fig. 1, a non-release substrate is used instead of the release material of (1), and as described above, it may be cured by irradiation with an active energy ray, or a non-release substrate/hardening may be produced. Optical film of matter.

In addition, in the second embodiment, the release material of any one of (1), (3), and (4) is produced by using a non-release substrate and hardening the active energy ray by the same method as described above. An optical film comprising a release material/cured material/non-release substrate, or an optical film comprising a non-release substrate/cured/non-release substrate.

Specific examples of the embodiment include a method in which a polarizing mirror is used as a non-release substrate, a coating film composition, an active energy ray is irradiated, and a protective film is directly formed on a polarizing mirror.

Further, in the above-mentioned example, an example in which a composition is coated on a substrate to produce an optical film is used. However, in the case of producing an optical film having a large film thickness, a composition such as a mold having a specific concave portion is poured, and The active energy ray is irradiated in the same manner as described above, and the composition is cured to produce an optical film.

5-2. Use of optical film

The optical film formed by the composition of the present invention can be used for various optical applications, and more specifically, a polarizer protective film for a polarizing plate such as a liquid crystal display device, a support film for a cymbal sheet, a light guiding film, etc. .

Hereinafter, a polarizing plate using a polarizer protective film (hereinafter simply referred to as "protective film") formed of the composition of the present invention will be described.

Polarizer

The polarizing plate is composed of a protective film on at least a single layer of the polarizer.

In the polarizing plate, the composition of the present invention is directly coated with a film by a polarizer to be cured to form a protective film, and a polarizing mirror and a protective film may be bonded to each other.

In the polarizing mirror, various materials can be used as long as they have a function of selectively illuminating a linear light in a certain direction from natural light.

2. For example, iodine is adsorbed on a polyvinyl alcohol film. The iodine-based polarizing film is aligned, and the dichroic dye is adsorbed on the polyvinyl alcohol film. The dyes of the alignment are polarized films, coated with dichroic dyes, and aligned. Immobilized coating type polarizer, etc. The iodine-based polarizing film, the dye-based polarizing film, and the coating-type polarizing lens have a linear polarized light that selectively transmits a certain direction from natural light, and absorbs the linear polarized light in the other direction. The thing that can be called the absorption type polarizer. Among these polarizers, an absorption type polarizer excellent in visibility is preferably used. The thickness of the absorption type polarizer is preferably 5 to 40 μm.

The polarizing plate of the present invention is a polarizing plate of an optical film of the present invention which is a protective film laminated on at least one side of a polarizing mirror, and is bonded by a binder.

For the bonding agent used for bonding the polarizer and the protective film, any one may be used in consideration of the respective adhesiveness.

Specific examples of the binder include a polyvinyl alcohol-based water-based binder, a solvent-based binder, a hot-melt binder, and a solvent-free binder, and a solvent-free active energy ray-curable type can be suitably used. Adhesive.

Examples of the active energy ray-curing type binder include a photocation-curable binder, a photo-radical-curing type binder, and a mixed-type binder in which photocationic curing and photo-radical curing are used in combination.

Examples of the photocationic curing type binder include a photocationic curable compound such as an epoxy compound and an oxetane compound, and a binder containing a photocationic polymerization initiator.

Examples of the photo-radical-curing type binder include a photo-radical curing compound such as a (meth) acrylate, a vinyl ether or a vinyl compound, and a binder containing a photo-radical polymerization initiator.

Examples of the mixed type binder include a photo-cation-curable compound, a photo-radical-curable compound, a photocationic polymerization initiator, and a photo-radical polymerization initiator.

In the case where the protective film is provided on both sides of the polarizer, it is preferable to have the protective film of the present invention on both sides. However, it can be used as needed The protective film of the present invention may be used on one side, and a protective film other than the protective film of the present application (hereinafter referred to as "other protective film") may be used on the other side.

The other protective film may, for example, be a cellulose acetate resin film such as triethylenesulfonyl cellulose or diethyl cellulose, an acrylic resin film, a polyester resin film, or a decene-like ring. A cyclic polyolefin resin film in which an olefin is used as a monomer. Moreover, in the case of using these as a protective film on the display side, it may be a film having a phase difference.

[Examples]

The present invention will be more specifically described by way of examples and comparative examples. In addition, the following "parts" means the parts by weight.

○Manufacturing Example A1 [ Manufacture of component (A)]

In a 500 mL reaction vessel equipped with a stirrer, a thermometer, and a cooler, IPDI: 145.9 g of isocyanate and dibutyltin dilaurate: 0.07 g as a catalyst were charged at room temperature (25 ° C or lower). Under a nitrogen atmosphere of 5 vol% of oxygen, while stirring, the temperature was raised to 70 °C.

A polycarbonate diol (Duranol T-5651, manufactured by Asahi Kasei Chemicals Co., Ltd., a number average molecular weight of 1,000): 43.0 g, 1,4-butanediol: 33.5 g, and methyl ethyl ketone (hereinafter, It is called "MEK": 65.0 g of the mixed solution, and after the internal temperature became 75 ° C or less, the reaction was carried out at an internal temperature of 80 ° C for 2 hours.

Thereafter, 2-hydroxyethyl acrylate (hereinafter referred to as "HEA"): 57.6 g, 2,6-di-tert-butyl-4-methylphenol as a polymerization inhibitor (hereinafter referred to as "BHT") was dropped. ”: 0.28g, MEK: 5.0g and dibutyl laurate Tin: 0.07 g of a mixed solution, and after the internal temperature became 75 ° C or lower, the reaction was carried out for 3 hours, and the spectrum was measured by an infrared absorption spectrum apparatus (FT-IR Spectrum 100 manufactured by Perkin Elmer Co., Ltd.) to confirm that the isocyanate group was completely consumed. A MEK solution (solid content: 80%) containing a urethane acrylate (hereinafter referred to as "UA-1") was obtained.

The weight average molecular weight (hereinafter referred to as Mw) of the converted polystyrene of UA-1 was measured by GPC (solvent: tetrahydrofuran, column: HSPgel HR MB-L, manufactured by Waters Co., Ltd.), and it was 2,300.

The photoelastic coefficient 1 was measured in accordance with the following, and was 12.3 × 10 ^-12 Pa ^-1 .

○Manufacturing Example A2 [ Production of component (A)]

In addition to Production Example A1, IPDI: 127.8 g as an isocyanate, Duranol T5651: 37.6 g as an alcohol solution, and tricyclo [5.2.1.0 ^2,6 ]decane dimethanol (TCDDM manufactured by Oxcea Co., Ltd.): 64.1 g and MEK: 65.0 g of a mixed solution and HEA: 50.5 g were subjected to the same operation to obtain a MEK solution (solid content: 80%) containing a urethane acrylate (hereinafter referred to as "UA-2").

The Mw and the photoelastic coefficient 1 of the obtained UA-2 were measured in the same manner as in Production Example A1, and as a result, Mw was 2,300 and the photoelastic coefficient 1 was 9.7 × 10 ^-12 Pa ^-1 .

○Manufacturing Example A3 [ Manufacture of component (A)]

In the production example A1, IPDI: 1501.4 g as an isocyanate, polycaprolactone triol as an alcohol solution [Plaxel 303 manufactured by Daicel Chemical Industry Co., Ltd.], number average molecular weight: 300): 18.3 g, Duranol T5651: 20.4 g, 1,4-butanediol: 28.2 g and MEK: The same operation was carried out except that 65.0 g of the mixed solution and HEA: 61.6 g, and a MEK solution (solid content: 80%) containing a urethane acrylate (hereinafter referred to as "UA-3") was obtained.

The Mw and the photoelastic coefficient 1 of the obtained UA-3 were measured in the same manner as in Production Example A1, and as a result, Mw was 2,400 and the photoelastic coefficient 1 was 13.5 × 10 ^-12 Pa ^-1 .

○Manufacturing Example A4 [ Manufacture of component (A)]

In addition to Production Example A1, IPDI: 148.8 g as an isocyanate, polyester diol as an alcohol solution [Exp4358, manufactured by DIC Corporation, esterified product of adipic acid and ethylene glycol, number average molecular weight of 500]: 42.1 g, 1,4-butanediol: a mixed solution of 30.4 g and MEK: 65.0 g, and HEA: 58.7 g, the same operation was carried out to obtain a urethane acrylate (hereinafter, referred to as "UA-4" ME) solution (solid content 80%).

The Mw and the photoelastic coefficient 1 of the obtained UA-4 were measured in the same manner as in Production Example A1. As a result, Mw was 1,900 and the photoelastic coefficient 1 was 12.6 × 10 ^-12 Pa ^-1 .

○Manufacturing Example A5 [ Manufacture of component (A)]

In addition to the production example A1, a mixed solution of IPDI: 99.6 g and MEK: 50.0 g as an isocyanate was prepared, and a spiral diol as an alcohol (hydroxyl price: 369 mgKOH/g, P-Mn: 304) [Mitsubishi Gas Chemical Co., Ltd. Limited Company SPG]: 74.4g and MEK (after adding SPG as powder, used for washing attached to the reaction vessel): 25.5g, ε-hexyl 2-hydroxyethyl acrylate as hydroxyl-containing acrylate Lactone 1 molar addition product (FA1DDM manufactured by Daicel Co., Ltd.): 95.6 g and MEK: 5.0 g The same operation was carried out except for the mixed solution, and a MEK solution (solid content: 80%) containing a urethane acrylate (hereinafter referred to as "UA-5") was obtained.

The Mw of the obtained UA-5 and the photoelastic coefficient 1 were measured in the same manner as in Production Example A1, and as a result, Mw was 2,400 and the photoelastic coefficient 1 was 11.6 × 10 ^-12 Pa ^-1 .

○Manufacturing Example A6 [ Manufacture of component (A)]

In the production example A1, IPDI: 134 g as an isocyanate, 1,4-butanediol as an alcohol solution: 34.2 g and MEK: 65.0 g, and FA1DDM as a hydroxyl group-containing acrylate: 104.8 g were used. Further, the same operation was carried out to obtain a MEK solution (solid content: 80%) containing a urethane acrylate (hereinafter referred to as "UA-6").

The Mw and the photoelastic coefficient 1 of the obtained UA-6 were measured in the same manner as in Production Example A1. As a result, Mw was 2,200 and the photoelastic coefficient 1 was 17.5 × 10 ^-12 Pa ^-1 .

○Production Example A'1 [ Production of urethane acrylate other than (A) component]

In a 500 mL reaction vessel equipped with a stirrer, a thermometer, and a cooler, IPDI: 196.0 g of isocyanate and dibutyltin dilaurate: 0.035 g as a catalyst were placed at room temperature, and nitrogen contained in 5% by volume of oxygen. In the environment, while stirring, the temperature was raised to 70 ° C.

Duranol T5651: 49.5 g as an alcohol was dropped so that the internal temperature became 75 ° C or lower, and then the reaction was carried out at an internal temperature of 80 ° C for 2 hours.

Then, HEA: 104.5 g and BHT: 0.09 g were dropped, and after the internal temperature became 75 ° C or lower, the reaction was carried out for 3 hours to obtain a urethane acrylate (hereinafter referred to as "UA'1").

The Mw and the photoelastic coefficient 1 of the obtained UA'1 were measured in the same manner as in Production Example A1, and as a result, Mw was 4,400 and the photoelastic coefficient 1 was 153 × 10 ^-12 Pa ^-1 .

○Manufacturing Example B1 [ Production of Component (B)]

In a 500 mL reaction vessel equipped with a stirrer, a thermometer, and a cooler, methyl methacrylate (hereinafter referred to as "MMA") was added: 20.0 g of N-propylene decyl porphyrin (hereinafter referred to as "ACMO"). 20.0 g and methyl isobutyl ketone (hereinafter referred to as "MIBK"): 200 g, and uniformly dissolved at room temperature.

While stirring the contents of the flask, the internal temperature was raised to 92 ° C in a nitrogen atmosphere, and after the internal temperature was constant, MMA was supplied over 8 hours: 80.0 g, and ACMO: 80.0 g was supplied over 3 hours. A polymerization initiator solution containing 10 g of V-65 [Wako Pure Chemical Industries Co., Ltd. 2,2'-azobis-2,4-dimethylvaleronitrile] and 40 parts of MIBK was continuously supplied for 5 hours.

After the continuous supply was completed, the internal temperature was maintained at 92 ° C, and the mixture was aged for 3 hours, and as a result, a solution having a negative photoelastic coefficient 2 (hereinafter referred to as "LP-1") (solid content: 47%) was obtained. .

The Mw of the obtained LP-1 was measured in the same manner as in Production Example A1, and as a result, Mw was 10,000. Further, the photoelastic coefficient 2 of LP-1 was -5.0 × 10 ^-12 Pa ^-1 as a result of the measurement described below.

Further, with respect to the photoelastic coefficient 2 of the component (B), the component (B) was added in an arbitrary ratio with respect to the urethane acrylate to be used, and the photoelastic coefficient value was measured at 23 ° C of the obtained optical film, and was calculated therefrom. The value of the photoelastic coefficient when the amount of addition of the linear amount of the addition amount and the photoelastic coefficient is 100% is described.

(1) Examples 1 to 12 and Comparative Examples 1 to 7 (manufacture of composition)

The components shown in Table 1 below were placed in a stainless steel container at a ratio shown in Table 1, and while heating, the mixture was stirred until uniform by a magnetic stirrer to obtain a composition.

The abbreviation in Table 1 means the following.

. LP-2: polymethyl methacrylate resin, Mitsubishi Rayon Co., Ltd. Dainal BR-87 [solid content; 100%, Mw; 25,000, acid value; 10.5 mg KOH/g, photoelastic coefficient 2; -6 × 10 ^-12 Pa ^-1 〕

. LP-3: N-vinyl-2-pyrrolidone/vinyl acetate copolymer, PVP/VA S-630 manufactured by ISP Japan Co., Ltd. [solid content; 100%, Mw; 45,000, photoelastic coefficient 2; 9×10 ^-12 Pa ^-1 〕

. Dc1173: 2-hydroxy-2-methyl-1-phenylpropan-1-one, DAROCUR-1173 manufactured by BASF Japan Co., Ltd.

(2) Examples F1 to F10 and Comparative Examples F1 to F6 (manufacture of optical film by electron beam hardening)

A film "Lumirror 50-T60" (surface untreated polyethylene terephthalate film, thickness 50 μm, hereinafter referred to as "Lumirror") made of Toray Co., Ltd., 300 mm wide by 300 mm in length, was coated with a coater to coat The compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 6 were dried at 80 ° C for 10 minutes to have a film thickness of 40 μm.

Thereafter, in the composition layer, a Lumirror having a width of 300 mm and a length of 300 mm was laminated, and an electron beam irradiation device manufactured by NHV Corporation, Inc. was used, and an acceleration voltage of 200 kV and a linear amount of 50 kGy (by beam current and transport speed) The electron beam was irradiated under the conditions of an oxygen concentration of 300 ppm or less to obtain an optical film.

After hardening, it was peeled off from Lumirror and used for the evaluation of the photoelastic coefficient 1, in-plane and thickness direction hysteresis described later.

(3) Examples F11 to F12 and Comparative Example 7 (Manufacture of optical film by ultraviolet curing)

In the Lumirror having a width of 300 mm and a length of 300 mm, the ultraviolet curable compositions obtained in Examples 11 to 12 and Comparative Example 7 were coated with a coater so that the film thickness after drying at 80 ° C for 10 minutes was 40 μm.

Thereafter, in a composition layer, a Lumirror having a width of 300 mm and a length of 300 mm was laminated, and a conveyor belt type ultraviolet irradiation device manufactured by Eyegraphics Co., Ltd. (high-pressure mercury lamp, lamp height of 12 cm, and irradiation intensity of 365 nm of 400 mW/cm ^{2 ) was used.} (Measurement value of UV POWER PUCK manufactured by Fusion UV System. Japan Co., Ltd.)) The conveyor belt speed was adjusted, and ultraviolet light having an integrated light amount of 1,000 mJ/cm ² was irradiated to obtain an ultraviolet curable optical film.

After hardening, it was peeled off from Lumirror and used for evaluation as described later.

[photoelastic coefficient 1]

The optical film obtained in the examples and the comparative examples was cut out to a thickness of 15 mm × 60 mm, and an automatic birefringence meter (KOBRA-WR, manufactured by Oji Scientific Instruments Co., Ltd.) was used to measure the tension at a temperature of 0 N to 10 N at room temperature. In the in-plane phase difference value at σ , the photoelastic coefficient 1 is obtained from the inclination of the approximate straight line which has been produced according to the following formula. The results are shown in Table 2.

△n=C. σ

(wherein Δn represents stress birefringence, σ represents tension, and C represents photoelastic coefficient 1).

Further, the photoelastic coefficient 1 of the cured product of the component (A) is cured in the same manner as in the production of the optical film by electron beam curing, and only the component (A) is cured, and the film is produced and measured in the same manner as described above. .

[in-plane and thickness direction lag]

In the optical film obtained in the examples and the comparative examples, a phase difference measuring device (KOBRA-21ADH manufactured by Oji Scientific Instruments Co., Ltd.) was used, and the in-plane lag of 40° on the front side and the inclination was measured (hereinafter referred to as “0°Re” and "40°Re" and the thickness direction lag (hereinafter referred to as "Rth"). These results are shown in Table 2.

Examples F1 to F12 are optical films obtained from the compositions of Examples 1 to 12 of the composition of the present invention, and have a photoelastic coefficient of 1, which is 13 × 10 which is a photoelastic coefficient 1 of TAC which is used as a protective film of the previous polarizer. ^-12 Pa ^-1 is smaller and there are no concerns about light leakage or whiteness. Further, the thickness direction is delayed, and is smaller than 30 to 40 nm of Rth of TAC (40 μm), and is excellent in viewing angle characteristics.

On the other hand, in Comparative Examples F1 to F5, since the component (B) was not contained, the photoelastic coefficient 1 or the thickness direction lag was large, and the two could not be simultaneously reduced. Further, in Comparative Examples F6 to F7, since the component (B) was contained, since the photoelastic coefficient 1 of the UA-5 monomer was large, the photoelastic coefficient 1 could not be sufficiently reduced.

○Production Example B2 [Preparation of carboxyl group-containing prepolymer]

In a 1 L reaction vessel equipped with a stirrer, a thermometer, and a cooler, methyl methacrylate (hereinafter referred to as "MMA") was added: 52.0 g of 2-hydroxyethyl methacrylate (hereinafter referred to as "HEMA"). :16.0g, methyl Acrylic acid (hereinafter referred to as "MAA"): 12.0 g, 3-hydrothiopropionic acid (hereinafter referred to as "MPA"): 3.2 g, methyl isobutyl ketone (hereinafter referred to as "MIBK"): 480 g , dissolve evenly at room temperature.

While stirring the contents of the flask, the internal temperature was raised to 92 ° C in a nitrogen atmosphere, and after the internal temperature was constant, MMA was added over 5 hours: 468.0 g, HEMA: 144.0, MAA: 108.0, MPA: 28.8 g. The mixed liquid was 748.8 g, and on the other hand, 2,2'-azobis-2,4-dimethylvaleronitrile (W-65, manufactured by Wako Pure Chemical Industries, Ltd.) was contained. Hereinafter, it is referred to as "V-65"]: 6.4 g and MEK: 80 g of a polymerization initiator solution were continuously added for 5.5 hours.

After the completion of the continuous addition, the internal temperature was maintained at 92 ° C, and the mixture was aged for 2 hours to obtain a solution of a carboxyl group-containing prepolymer (hereinafter referred to as "LP-4") (solid content: 62%).

When Mn, Mw, and photoelastic coefficient 2 of the obtained LP-4 were measured in the same manner as in Production Example B1, Mn was 3,200, Mw was 5,800, and photoelastic coefficient 2 was 0.2 × 10 ^-12 . Pa ^-1 .

These results are shown in Table 3. In addition, the number in Table 3 is described in the ratio of the ratio of the total monomer used to 100% by weight, and the organic solvent to be used and the ratio thereof are omitted.

○Production Example B3 [Preparation of carboxyl group-containing prepolymer]

In the production example B2, the materials used for the change were described in Table 3, and the same operation was carried out to obtain a carboxyl group-containing prepolymer having a negative photoelastic coefficient of 2 (hereinafter referred to as "LP-5". Solution (solid content 62%).

When Mn, Mw, and photoelastic coefficient 2 of the obtained LP-5 were measured in the same manner as in Production Example B1, Mn was 4,400, Mw was 11,000, and photoelastic coefficient 2 was -2.0 × 10 ^-12 . Pa ^-1 . These results are shown in Table 3.

○Manufacturing Example B4 [Production of Polymer Containing a Carboxyl Group at the End]

In a 1 L reaction vessel equipped with a stirrer, a thermometer, and a cooler, MMA: 400.0 g, MPA: 5.8 g, and MIBK: 640.0 g were charged, and the mixture was uniformly dissolved at room temperature.

The contents of the flask were heated to an internal temperature of 92 ° C in a nitrogen atmosphere while stirring. After the internal temperature was constant, MMA: 400.0 g and MPA: 8.64 g were added over 3 hours, and V was contained. -65: 1.3 g and MEK: 32 g of a polymerization initiator solution (1) Each of the polymerization initiator solutions (2) containing V-65: 5.2 g and MEK: 128.0 g over 4 hours was continuously added for 2 hours.

After the continuous addition was completed, the internal temperature was maintained at 92 ° C, and aging was carried out for 2 hours to obtain a solution of a terminal carboxyl group-containing polymer having a negative photoelastic coefficient of 2 (hereinafter referred to as "LP-6") (solid content) 51%).

When Mn, Mw, and photoelastic coefficient 2 of the obtained LP-6 were measured in the same manner as in Production Example B1, Mn was 6,000, Mw was 12,000, and photoelastic coefficient 2 was -4.0 × 10 ^-12 . Pa ^-1 . These results are shown in Table 3.

○Manufacturing Example B5 [ Manufacture of component (B)]

In a 1 L reaction vessel equipped with a stirrer, a thermometer, and a cooler, LP-4: 350.0 g (solid content 62%) was charged, and after raising the temperature to 92 ° C, a 5% oxygen-nitrogen mixed gas was blown while stirring at 180 rpm for 1 hour. . Thereafter, BHT as a polymerization inhibitor was added in an amount of 0.11 g, DBTDL as a catalyst: 0.05 g, and 2-propenyloxyethyl isocyanate (Calends AOI manufactured by Showa Denko Co., Ltd.). Hereinafter, it is called "AOI": 43.0 g, and it stirred for 4 hours.

The completion of the urethanation reaction confirms the disappearance of the isocyanate groups in the solution by infrared spectroscopy. A solution of the component (B) (hereinafter referred to as "ULP-1") (solid content: 64%) was obtained in this manner.

The Mn, Mw, and photoelastic coefficient 2 of the obtained ULP-1 were measured in the same manner as in Production Example B1. Further, the f value of ULP-1 is calculated according to the equation (3).

The results of Mn, Mw, f value of ULP-1, introduction site of unsaturated group, and photoelastic coefficient 2 are shown in Table 4.

In addition, the description of the number in Table 4 is a ratio of the ratio of the total amount of the monomers used in the production of the prepolymer to 100% by weight, and the solvent to be used and the ratio thereof are omitted.

○ Manufacturing Examples B6 to 16 [Production of Component (B)]

In Production Example B5, the types and ratios of the monomers used in the production of the prepolymer were changed as described in Tables 4 and 5, and the types and ratios of the compounds used in the addition reaction were changed. Operation, a solution of the component (B) (solid content 51 to 64%) was obtained.

The Mn, Mw, f value and photoelastic coefficient 2 of the obtained ULP-2 to 12 were measured in the same manner as in Production Example B6. These results are shown in Tables 4 and 5 together with the introduction site of the unsaturated group.

In addition, in the production examples B11 and B14, the completion of the reaction of the carboxyl group and the epoxy group was carried out by using an automatic titrator (COM-900, manufactured by Hiranuma Sangyo Co., Ltd.) to confirm the disappearance of the acid value in the reaction solution.

In Tables 4 and 5, f is the average ethylenically unsaturated group in one molecule.

Further, the abbreviations in Tables 3 to 5 include the above-defined ones as shown below.

. MMA: Methyl methacrylate

. HEMA: 2-hydroxyethyl methacrylate

. MAA: Methacrylic acid

. MA: Methyl acrylate

. GMA: glycidyl methacrylate

. ACMO: propylene fluorenyl porphyrin

. V-65: 2,2'-azobis-2,4-dimethylvaleronitrile

. MPA: 3-hydrothiopropionic acid

. MTG: 2-hydrogen thioethanol

. DM: dodecyl mercaptan

. AOI: 2-propenyl methoxyethyl isocyanate

. AA: Acrylic

. MOI: 2-Methyl propylene oxirane ethyl isocyanate

. DBTDL: Dibutyltin dilaurate

. TBAB: tetrabutylammonium bromide

. BHT: 2,6-di-tertiary butyl-4-methylphenol

(4) Example U1 to the same U20 and Comparative Example U1 to the same U2 (manufacture of the composition)

The components shown in Tables 6 to 9 to be described later were placed in a stainless steel container at a ratio shown in Tables 6 to 9, and the mixture was heated while stirring with a magnetic stirrer to obtain a composition.

In Table 7, M309 means trimethylol propyl triacrylate (Aronics M-309 manufactured by Toagosei Co., Ltd.).

(5) Examples UF1 to UF20 and Comparative Examples UF1 and UF2 (manufacture of optical film by electron beam hardening)

Film film "Lumirror 50-T60" (surface untreated polyethylene terephthalate film, thickness 50 μm, hereinafter referred to as "Lumirror") made of Toray Co., Ltd., which is 300 mm wide by 300 mm in length, is coated with a coater. The composition obtained from U1 to U20 and Comparative Examples U1 to U2 was such that the film thickness after drying at 120 ° C for 10 minutes was 40 μm.

Then, after the composition layer was laminated with a Lumirror having a width of 300 mm and a length of 300 mm, an electron beam irradiation apparatus manufactured by NHV Corporation, Inc. was used at an acceleration voltage of 200 kV and a linear amount of 150 kGy (adjusted by beam current and transport speed). Electron beam irradiation was carried out under the conditions of an oxygen concentration of 300 ppm or less to obtain an optical film.

After hardening, it was peeled off from Lumirror, and the photoelastic coefficient 1, in-plane and thickness direction retardation were evaluated in the same manner as described above. Further, the cutting property and the bending resistance were evaluated in accordance with the methods described below.

[cutting property]

In order to evaluate the softness of the produced film, the cutting property at the time of cutting with a cutter knife was evaluated on the following basis. These results are shown in Table 10.

○: a state in which it can be smoothly cut

△: Slight lack of smoothness

×: the state of the crack generated in the profile at the time of cutting

[bending resistance]

In order to evaluate the flexibility of the produced film, the resistance when the film cut out of 15 mm × 150 mm was bent by 180° was evaluated on the basis of the following criteria. These results are shown in Table 10.

○: Bending 3 times rupture

△: Bending 1 to 2 times of rupture

×: 1 break in the bend

Examples UF1 to UF17 are optical films obtained from the compositions of Examples U1 to U17 of the composition of the present invention, and the photoelastic coefficient 1 is 13 × that is the photoelastic coefficient 1 of the TAC used as the protective film of the previous polarizer. 10 ^-12 Pa ^-1 is smaller and there are no concerns about light leakage or whiteness. Further, the thickness direction is delayed, and is smaller than 30 to 40 nm of Rth of TAC (40 μm), and is excellent in viewing angle characteristics. Further, the flexibility is also excellent.

On the other hand, in Examples UF18 to UF20, even if the photoelastic coefficient 1 had a low or negative polymer, it was composed of a composition containing the (B)' component having no ethylenically unsaturated group (Comparative Examples U18 to U20). The optical film produced was the same as the Example, and although it had excellent photoelastic coefficient 1 and hysteresis, it lacked flexibility.

In Comparative Example UF1, the optical film produced from the composition containing no component (B) (Comparative Example U1) had a large hysteresis in the photoelastic coefficient 1 and the thickness direction, and could not be made small at the same time. Comparative Example UF2 is an optical film produced from a composition (Comparative Example U2) using a urethane acrylate different from the component (A), which has a photoelastic coefficient of 1 being large.

○Manufacturing example PL1 [ Manufacture of polarizer]

A polyvinyl alcohol film having a thickness of 80 μm was swollen in a water bath at 30 ° C, and then dyed in an aqueous solution of iodine at a weight ratio of 5% by weight (iodine: potassium iodide = 1/10). Next, it was immersed in an aqueous solution containing 3% by weight of boric acid and 2% by weight of potassium iodide, and further immersed in 5 in an aqueous solution containing 4 wt% of boric acid and 3 wt% of potassium iodide at 55 ° C for one-axis extension to 5.5 times. A weight% potassium iodide aqueous solution. Thereafter, the film was dried in an oven at 70 ° C for 1 minute to obtain a polarizer having a thickness of 30 μm (hereinafter referred to as a polarizer P).

The polarizing lens P obtained was measured for a degree of polarization and a single transmittance of 99.99% and 43.1%, respectively, using a spectrophotometer (UV-2200 manufactured by Shimadzu Corporation).

○Manufacturing example V1 [ Manufacture of ultraviolet curing type binder]

50 parts of bisphenol A diglycidyl ether (jER807 manufactured by Japan Epoxy Resin Co., Ltd.), 20 parts of tetrahydrofurfuryl acrylate (THF-A manufactured by Osaka Organic Chemical Industry Co., Ltd.), and 30 parts of acrylic acid 4- Iodine (4-methylphenyl) [4-(2-) of hydroxybutyl ester (4-HBA, manufactured by Nippon Kasei Co., Ltd.) and 4 parts of photopolymerization initiator (hereinafter referred to as "photoinitiator") Methylpropyl)phenyl]hexafluorophosphate (IRGACURE 250, manufactured by BASF Japan Co., Ltd.), 1 part of 2,4-diethyl-9-oxosulfur (Kayacure DETX-s manufactured by Nippon Kayaku Co., Ltd.) was placed in a stainless steel container and stirred until it became uniform by a magnetic stirrer to obtain an ultraviolet curable adhesive (hereinafter referred to as a binder UVX1).

(6) Example P1, the same P2, and Comparative Example P1 (manufacture of a polarizing plate)

Using the optical films obtained in Examples F3 and F5 and Comparative Example F6 as polarizer protective films, the adhesive UVX1 was applied on both sides of the polarizer P with a film thickness of 5 μm , and after bonding the optical film, according to Eyegraphics shares limited Conveyor belt type UV irradiation device (high pressure mercury lamp, lamp height 15cm, 365nm irradiation intensity 370mW/cm ² (measured value of UV POWER PUCK manufactured by Fusion UV System.Japan System Co., Ltd.)), adjust conveyor speed Ultraviolet irradiation of a cumulative light amount of 220 mJ/cm ^{2 was} carried out to obtain a polarizing plate (width: 100 mm × length: 100 mm).

In addition, no corona treatment is applied to any polarizer protective film.

[Measurement of Polarization and Monomer Transmission Rate]

For the polarizing plates obtained in the examples and the comparative examples, a polarizing plate spectrophotometer (UV-2200 manufactured by Shimadzu Corporation) was used to measure the degree of polarization and the monomer transmittance. These results are shown in Table 11.

[Polarity of polarizer protective film and polarizer]

In the polarizing plates obtained in the examples and the comparative examples, the tackiness of the polarizer protective film and the polarizer P was evaluated by the following criteria in a state in which a twist was applied by a hand twist. These results are shown in Table 11.

○: The polarizing mirror and the polarizer protective film are integrated, and no peeling occurs.

×: Peeling was confirmed between the polarizer and the polarizer protective film.

[Damp heat resistance of polarizing plate]

The polarizing plates obtained in the examples and the comparative examples were placed in a constant temperature and humidity chamber at 60 ° C and 90% RH for 120 hours, and then the samples were visually evaluated by the following criteria. These results are shown in Table 11.

○: No deformation was observed.

×: Deformation is visible.

In Examples P1 and P2, a polarizing plate of the optical film obtained in Examples F3 and F5 which is a composition of the present invention was used, which maintained the performance of the polarizing mirror P, and was excellent in adhesion and moisture resistance.

On the other hand, in Comparative Example P1, the polarizing plate of the optical film obtained in Comparative Example F6 was used, and the performance of the polarizing mirror P was maintained, and the adhesiveness was good, but the moist heat resistance was lowered.

(7) Example P3 to Example P12 (manufacture of polarizing plate)

A polarizing plate was produced in the same manner as in Example P1 except that the optical films obtained in Examples F1, F2, F4, and F6 to F12 were used as the polarizer protective film, and the moisture resistance was evaluated.

In any of the polarizing plates of Examples P3 to P12, the heat and humidity resistance was good.

○Manufacturing example V2 [ Manufacture of ultraviolet curing type binder]

40 parts of bisphenol A diglycidyl ether (jER807 manufactured by Japan Epoxy Resin Co., Ltd.), 20 parts of tetrahydrofurfuryl acrylate (THF-A manufactured by Osaka Organic Chemical Industry Co., Ltd.), and 30 parts of 4-hydroxy acrylate Butyl ester (4-HBA manufactured by Nippon Kasei Co., Ltd.), 10 parts of isomeric cyanuric acid ethylene oxide denatured di- and triacrylate (Aronics M-313 manufactured by Toagosei Co., Ltd.), and 6 parts of light a 50% by weight propylene carbonate solution of diphenyl-4-(phenylthio)phenylphosphonium hexafluorophosphate (CPI-100P manufactured by San-apro Co., Ltd.), and 1 part of 1-hydroxycyclohexyl benzophenone ( Irgacure 184) manufactured by BASF Japan Co., Ltd. was placed in a stainless steel container and stirred until it was uniform by a magnetic stirrer to obtain an ultraviolet curable adhesive (hereinafter referred to as a binder UVX2).

(8) Example UP1, UP2 and Comparative Example are the same as UP1 (manufacture of polarizing plate)

A polarizing plate (width 100 mm × length 100 mm) was obtained in the same manner as in Example P1 except that the optical film obtained as the polarizer protective film Example UF7, the same UF10 and Comparative Example UF2 was used, and UVX2 as a binder was used. ).

Further, the corona treatment is not performed even with respect to any of the polarizer protective films.

With respect to the polarizing plates obtained in the examples and the comparative examples, the degree of polarization and the monomer transmittance were measured in the same manner as in the example P1, and the adhesion and polarization of the polarizer protective film and the polarizer were evaluated in the same manner as described above. The board is resistant to heat and humidity. These results are shown in Table 12.

Examples UP1 and UP2 are polarizing plates of optical films obtained by using Examples UF7 and UF10 of the composition of the present invention, which maintain the performance of the polarizing mirror P, and have good adhesion and moisture resistance, and are protected as polarizers. The film is effective.

On the other hand, in Comparative Example UP1, the polarizing plate of the optical film obtained in Comparative Example UF2 was used, and the performance of the polarizing mirror P was maintained, and although the adhesiveness was good, the moist heat resistance was lowered.

(9) Example UP3 to Example UP20 (Manufacture of polarizing plate)

Except that the optical films obtained as the polarizer protective films of Examples UF1 to UF6, UF8, UF9, and UF11 to F20 were used, as in Example UP1, polarizing plates were separately prepared, and the moist heat resistance was evaluated.

The polarizing plates of any of the examples UP3 to UP20 were all excellent in moist heat resistance.

[Industrial availability]

The active energy ray-curable composition for forming an optical film of the present invention can be suitably used for the production of an optical film.

Further, the optical film of the present invention can be suitably used in the use of a polarizer protective film as described in detail above.

(1), (3), (4) ‧ ‧ release material

(2) ‧ ‧ constituent layers

F1‧‧‧ solvent-free composition

F2‧‧‧ solvent system composition

Fig. 1 is a view showing an example of the production of an optical film using the composition of the present invention.

Fig. 2 is a view showing another example of the production of an optical film using the composition of the present invention.

(1) ‧‧‧ release material

(2) ‧ ‧ constituent layers

F1‧‧‧ solvent-free composition

F2‧‧‧ solvent system composition

Claims (23)

An active energy ray-curable composition for forming an optical film, comprising: a urethane having a photoelastic coefficient 1 of a cured product of 5 × 10 ^-12 Pa ^-1 or more and 30 × 10 ^-12 Pa ^-1 or less; a methyl acrylate (A); and a polymer having a photoelastic coefficient 2 of -15 × 10 ^-12 Pa ^-1 or more and 5 × 10 ^-12 Pa ^-1 or less, and a component other than the component (A) B) The following photoelastic coefficient 1 of the cured product of the composition is -10 × 10 ^-12 Pa ^-1 or more and 10 × 10 ^-12 Pa ^-1 or less, and the thickness of the cured product is measured at a thickness of 40 μm. The in-plane hysteresis of ° and the hysteresis in the thickness direction are -5 nm or more and 5 nm or less (wherein the photoelastic coefficient 1 means the photoelastic coefficient at 23 ° C; and the photoelastic coefficient 2 means the measurement relative to the use ( A) component, the value of the photoelastic coefficient of the optical film obtained by adding the component (B) at an arbitrary ratio at 23 ° C, and the value obtained by extrapolating the amount of the added amount and the photoelastic coefficient from the linear chart by 100% ). The active energy ray-curable composition for forming an optical film according to the first aspect of the invention, wherein the component (A) is a compound having no aromatic group. The active energy ray-curable composition for forming an optical film according to the first aspect of the invention, wherein the component (A) is an oligomer having two or more (meth)acryl fluorenyl groups and a weight average molecular weight of 1,000 to 15,000. The active energy ray-curable composition for forming an optical film according to the first aspect of the invention, wherein the component (A) is a reactant of a polyol, an organic polyisocyanate, and a hydroxyl group-containing (meth) acrylate. An active energy ray-curable composition for forming an optical film according to the fourth aspect of the invention, wherein in the component (A), the polyol is an aliphatic or alicyclic diol having 2 to 12 carbon atoms or polycarbonate. An ester diol or a polyester diol and an aliphatic or alicyclic diol having 2 to 12 carbon atoms, and the organic polyisocyanate is a non-yellowing organic diisocyanate. An active energy ray-curable composition for forming an optical film according to claim 4, wherein in the component (A), an aliphatic group or a fat having an average molecular weight of 62 or more and a carbon number of 2 to 12 or less is less than 500. The cyclodiol, the organic polyisocyanate is a non-yellowing organic diisocyanate, and the hydroxyl group-containing (meth) acrylate is a hydroxyl group-containing (meth) acrylate caprolactone adduct. The active energy ray-curable composition for forming an optical film according to the first aspect of the invention, wherein the component (B) is a single polymer or copolymer of a monomer having a (meth) acrylonitrile group. The active energy ray-curable composition for forming an optical film according to claim 7, wherein the component (B) is a copolymer of a (meth) acrylonitrile-based monomer having a guanamine structure or a carboxyl group. Copolymer. An active energy ray-curable composition for forming an optical film according to the first aspect of the invention, wherein the component (B) is an N-vinyl-2-pyrrolidone copolymer. The active energy ray-curable composition for forming an optical film according to the first aspect of the invention, wherein the component (B) is a polymer having an ethylenically unsaturated group. An active energy ray-curable composition for forming an optical film according to claim 10, wherein the ethylenically unsaturated group in the component (B) is a (meth) acrylonitrile group. The active energy ray-curable composition for forming an optical film according to claim 11, wherein the component (B) is one or more selected from the group consisting of: in a polymer having a carboxyl group, the addition has a ring a polymer obtained from a compound of an oxy group and an ethylenically unsaturated group; a polymer obtained by adding a compound having a carboxyl group and/or a hydroxyl group-containing polymer to a compound having an isocyanate group and an ethylenically unsaturated group; A polymer obtained by adding a compound having a carboxyl group and an ethylenically unsaturated group to a polymer containing an epoxy group. The active energy ray-curable composition for forming an optical film according to claim 12, wherein the carboxyl group-containing polymer, the hydroxyl group-containing polymer or the epoxy group-containing polymer has a (meth) acrylonitrile group a copolymer of a compound. The active energy ray-curable composition for forming an optical film according to claim 12, wherein the carboxyl group-containing polymer or the hydroxyl group-containing polymer is a polymer each having a carboxyl group at a terminal or a hydroxyl group at a terminal. Things. The active energy ray-curable composition for forming an optical film according to the first aspect of the invention, wherein the component (A) and the component (B) are contained in an amount of 10 to 80% by weight based on the total amount of the component (A), and 20 to 90% by weight of the component (B). The active energy ray-curable composition for forming an optical film according to any one of claims 1 to 15, which is an electron beam curable composition for forming an optical film. An optical film obtained by forming a cured product of the composition according to any one of claims 1 to 15 in a film form or a sheet form. A polarizer protective film comprising the optical film of claim 17 of the patent application. A method for producing an optical film, which comprises applying a composition according to any one of claims 1 to 15 to a sheet-form substrate, and then irradiating the active energy ray from the side of the coating film or the side of the sheet substrate. The method of producing an optical film according to claim 19, wherein the sheet substrate is a peelable substrate. A method for producing an optical film, which comprises applying the composition according to any one of claims 1 to 15 to a sheet-like substrate, and bonding the other sheet-like substrate to the coating film surface of the composition. The active energy line is illuminated on either side of the sheet substrate. The method of producing an optical film according to claim 21, wherein any one or both of the sheet substrates are exfoliable substrates. A polarizing plate which is laminated on at least one side of a polarizer formed of a polyvinyl alcohol-based resin, and a polarizing plate laminated with a polarizer protective film of claim 18, wherein the polarizer is bonded to the adhesive layer via a bonding layer The polarizer protects the film.