JP5891972B2 - Optical film or sheet, polarizer protective film, and polarizing plate - Google Patents

Description

The present invention relates to an optical film or sheet, and a polarizing plate using the same as a polarizer protective film, and belongs to these technical fields.
In the following, for convenience, unless otherwise specified, “film or sheet” is represented as “film”, and film or sheet is represented as “film”. Further, acrylate or methacrylate is represented as (meth) acrylate.

In recent years, with the increase in size of liquid crystal displays, it has become necessary to increase the size of optical films.
However, when the size of the optical film is increased, the bias of external force is generated. Therefore, when the optical film is made of a material that easily changes birefringence due to the external force, there is a problem that birefringence distribution occurs and the contrast becomes non-uniform. The ease with which birefringence changes due to external force are expressed by the absolute value of the photoelastic coefficient, but a triacetyl cellulose (hereinafter referred to as “TAC”) film generally used as a polarizer protective film is an optical material. The absolute value of the elastic coefficient is large, and light birefringence occurs due to the occurrence of stress birefringence accompanying the polarizer contraction.

  Therefore, there is a demand for a low photoelastic coefficient film that replaces the TAC film.

  Patent Document 1 discloses that photoelasticity is reduced by blending an acrylic resin having negative photoelasticity with a cellulose ester resin having positive photoelasticity, but cellulose having a high water absorption rate is disclosed. Therefore, if the polarizing plate using the film as a polarizer protective film is used at high temperature or high humidity, the polarizing plate may be deformed or polarized light such as the degree of polarization and hue may be changed. There is a disadvantage that the performance of the plate is lowered.

  In Patent Document 2, a low photoelastic coefficient is realized by blending polyvinyl pyrrolidone with cellulose ester resin. However, since it is a combination of cellulose ester resin and polyvinyl pyrrolidone, the composition described in Patent Document 1 There is a problem that the heat and humidity resistance deteriorates.

Patent Document 3 discloses that an optical film made of urethane (meth) acrylate has a small photoelastic coefficient, but the absolute value of the photoelastic coefficient is as large as TAC (13 × 10 ⁻¹² Pa ⁻¹ ), It was not satisfactory enough.

  In Patent Document 4, as an optical film applied to enlargement of a liquid crystal display, for example, a thermoplastic resin film having a positive photoelastic coefficient (for example, a cellulose acetate film) and a heat having a negative photoelastic coefficient are disclosed. A low photoelastic coefficient has been achieved by bonding a plastic resin film (for example, polymethylmethacrylate film) via an adhesive, but there is an increase in the amount of foreign matter and an increase in cost due to the bonding, etc. There is a problem.

Japanese Patent Publication No. WO09-81607 JP 2008-111056 A JP 2011-145330 A JP 2009-234104 A

  An object of the present invention is to provide an optical film that can be produced by a simple and economical production method without using an adhesive or the like, can be further thinned, and has a low photoelastic coefficient.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the resin film having a negative photoelastic coefficient is a film-like cured product of an active energy ray-curable composition and is positive on at least one side. It has been found that an optical film on which a resin layer having a photoelastic coefficient is formed is effective.

  According to the composition of the present invention, an optical film having a low photoelastic coefficient, a polarizer protective film, and a polarizing plate can be provided by a simple production method.

FIG. 1 shows an example of a method for producing an optical film of the present invention.

The present invention provides at least one surface of a resin film (hereinafter referred to as “resin film (NR)”) having a negative photoelastic coefficient at 23 ° C. (hereinafter simply referred to as “photoelastic coefficient”),
An active energy ray-curable composition (hereinafter referred to as “composition” ) containing a urethane (meth) acrylate (A) which is a compound having no aromatic group and has a weight average molecular weight of 1,000 to 15,000. And an optical film including a film-like cured product (hereinafter simply referred to as “cured product”),
Photoelastic coefficient of the cured product have a positive value,
An optical film in which the cured product is directly formed on the resin film (NR) without using an adhesive ;
And a polarizing plate using the same as a polarizer protective film.
Details of the present invention will be described below. In the present specification, a crosslinked product and a cured product obtained by irradiating the composition with active energy rays are collectively referred to as a “cured product”.

1. Resin film (NR)
The resin film (NR) is a resin film having a negative photoelastic coefficient.
As the resin film (NR), various resins can be used as long as the resin film has a negative photoelastic coefficient.
Specific examples of the resin film (NR) include an acrylic resin film such as polymethyl methacrylate and a styrene resin film such as poly α-methylstyrene. Moreover, the resin film etc. which mixed 2 or more types of these resin are mentioned.

The photoelastic coefficient of the resin film ^{(NR), -10 × 10 -12} ~-1 × 10 -12 Pa -1 , more preferably ^{-10 × 10 -12 ~-2 ×} 10 -12 Pa -1 It is. The photoelastic coefficient of the optical film can be easily adjusted by using a resin film (NR) having a photoelastic coefficient within the above range.

In the present invention, the photoelastic coefficient is a coefficient representing the ease of occurrence of a change in birefringence due to an external force, and means that the change in birefringence due to an external force is smaller as the value of the photoelastic coefficient is closer to zero.
Specifically, the photoelastic coefficient (C) is a value defined by the following equation, where σ is an extensional stress and Δn is a birefringence when stress is applied.
C [Pa ⁻¹ ] = Δn / σ
Here, Δn is defined by the following equation, where n ₁ is the refractive index in the direction parallel to the stretching direction and n ₂ is the refractive index in the direction perpendicular to the stretching direction.
Δn = n ₁ −n ₂
In addition, the photoelastic coefficient in this invention means the value measured at the temperature of 23 degreeC.

2. Cured product of composition The optical film of the present invention comprises a cured product of the composition in the above-described resin film (NR). Further, a composition whose cured product has a positive photoelastic coefficient is used.

The photoelastic coefficient of the cured product of the composition is preferably 1 × 10 ⁻¹² to 10 × 10 ⁻¹² Pa ⁻¹ , more preferably 2 × 10 ⁻¹² to 10 × 10 ⁻¹² Pa ⁻¹ . The photoelastic coefficient of an optical film can be easily adjusted by using the photoelastic coefficient of the hardened | cured material of a composition for the said range.

As the composition, various compositions can be used as long as the cured product of the obtained composition satisfies the photoelastic coefficient and can form an optical film.
Among them, urethane (meth) acrylate (A) [A ] which is a compound having no aromatic group and having a weight average molecular weight of 1,000 to 15,000 in that the obtained cured product is excellent in mechanical properties. Hereinafter, the composition containing “(A) component”] is used .
Hereinafter, the composition containing the component (A) will be described.

2-1. (A) Component Examples of the component (A) include a reaction product of a polyol, an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate.
The component (A) is a urethane (meth) acrylate having two or more (meth) acryloyl groups, and a urethane (meth) acrylate having two (meth) acryloyl groups is preferable.
As the component (A), urethane (meth) acrylate having no aromatic group is used. The urethane (meth) acrylate is preferable because it has a low photoelastic coefficient. The urethane (meth) acrylate having no aromatic group can be produced by using a compound having no aromatic group as a raw material polyol, organic polyisocyanate, and hydroxyl group-containing (meth) acrylate.
(A) The weight average molecular weight of the component (hereinafter, referred to as "Mw") are 1,000 and 15,000, good Mashiku is 1,000 to 10,000.
In the present invention, Mw is a value obtained by converting the molecular weight measured by gel permeation chromatography (hereinafter referred to as “GPC”) into polystyrene.
(A) A component may use only 1 type or may use 2 or more types together.
Hereinafter, the polyol, the organic polyisocyanate and the hydroxyl group-containing (meth) acrylate, which are the raw material compounds of the component (A), and the method for producing the component (A) will be described.

2-1-1. As the polyol polyol, a diol is preferably used, and various diols can 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, 1,3-butanediol, 1,4-butanediol, poly Tetramethylene glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2-ethyl-1,3-hexaneglycol, 2,2,4- And aliphatic diols such as trimethyl-1,3-pentanediol, 3,3-dimethylolheptane, 1,9-nonanediol and 2-methyl-1,8-octanediol.

Examples of the alicyclic diol having 2 to 12 carbon atoms include cyclohexanedimethanol, tricyclo [5.2.1.0 ^2,6 ] decanedimethanol (common name: tricyclodecanedimethanol), and 1,4-decahydronaphthalene. Diol, 1,5-decahydronaphthalenediol, 1,6-decahydronaphthalenediol, 2,6-decahydronaphthalenediol, 2,7-decahydronaphthalenediol, decahydronaphthalenediethanol, norbornanediol, norbornanedimethanol , Decalin dimethanol, adamantanediol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane (common name; spiroglycol), Isosorbide, isomannide, 2,2-bis (4-hydride) Xicyclohexyl) propane (common name; hydrogenated bisphenol A), 4,4'-dihydroxydicyclohexylmethane (common name; hydrogenated bisphenol F), 1,1-bis (4-hydroxycyclohexyl) -1,1-dicyclohexylmethane (common name) Hydrogenated bisphenol Z) and alicyclic diols such as 4,4-bicyclohexanol.

Examples of the polycarbonate diol include a reaction product of a low molecular weight diol or / and a polyether diol and a dialkyl ester carbonate such as ethylene carbonate and dibutyl carbonate.
Here, examples of the low molecular weight diol include ethylene glycol, propylene glycol, cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 1,5-pentanediol, 1,6-hexanediol, and the like.
Examples of polyether diols include polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and block or random polymer diols such as polyethylene polypropoxy block polymer diols.

  The polyester diol is an ester of the low molecular weight diol or / and the polyether diol with an acid component such as a dipic acid such as adipic acid, succinic acid, tetrahydrophthalic acid and hexahydrophthalic acid or an anhydride thereof. And the like.

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

  As the polyol, in order to improve the mechanical strength of the cured product, it is preferable to use a triol in addition to the diol.

  Triols include 1,2,6-hexanetriol, 1,2,3-heptanetriol, 1,2,4-butanetriol, trimethylolpropane, trimethylolethane, kacilitol, pyrogallol, glycerin and tris (2-hydroxy). Ethyl) isocyanurate, and adducts of these triols such as ε-caprolactone, ethylene oxide and propylene oxide.

As the caprolactone adduct of triol, a caprolactone adduct of trimethylolpropane and a caprolactone adduct of glycerin are preferable. The triol caprolactone adduct 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 trica-cacaprolactone adduct is commercially available, and examples thereof include Plaxel 303, 305, 308, 312 and L320ML (manufactured by Daicel Chemical Industries, Ltd.).

These polyols may be used alone or in combination of two or more.
When brittleness and flexibility are required as the component (A), it is more preferable to use an aliphatic diol having 2 to 12 carbon atoms or an alicyclic diol having 2 to 12 carbon atoms as the polyol.
In the case where mechanical properties are required as the component (A), and more specifically, those having excellent breaking strength and tensile modulus are required, the number average molecular weight based on hydroxyl value (hereinafter referred to as “P” as a polyol). -Mn ") is preferably used in combination of a polyol having 500 or more and a polyol having P-Mn of less than 500.
In addition, in this invention, P-Mn (number average molecular weight) of a polyol means the value calculated | required according to the following formula.

  More specifically, examples of the polyol having a P-Mn of 500 or more include polycarbonate diol and polyester diol, and examples of the polyol having a P-Mn of less than 500 include an aliphatic diol having 2 to 12 carbon atoms and 2 to 12 carbon atoms. These alicyclic diols can be mentioned, and these are used in combination.

2-1-2. Organic polyisocyanate As organic polyisocyanate, organic diisocyanate is preferable, and non-yellowing type organic diisocyanate is more preferable.
Non-yellowing organic diisocyanates include hexamethylene diisocyanate, lysine methyl ester diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dimer acid diisocyanate and other aliphatic diisocyanates, isophorone diisocyanate (hereinafter referred to as “IPDI”), 4, Examples include alicyclic diisocyanates such as 4'-methylenebis (cyclohexyl isocyanate), norbornane diisocyanate, and ω, ω'-diisocyanate dimethylcyclohexane.

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

  Among the above-mentioned compounds, IPDI is preferable because it is excellent in mechanical strength and optical properties of the cured product.

2-1-3. Hydroxyl group-containing (meth) acrylate As hydroxyl group-containing (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polycaprolactone-modified hydroxyethyl acrylate , Hydroxyalkyls such as hydroxypentyl (meth) acrylate, hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, pentaerythritol tri, di or mono (meth) acrylate, and trimethylolpropane di or mono (meth) acrylate ( And (meth) acrylate.
Among the above-mentioned compounds, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like in that the curability of the composition and the flexibility of the cured product are excellent. Polycaprolactone-modified hydroxyethyl acrylate is preferred.

2-1-4. (A) Manufacturing method of component (A) The component may be manufactured according to a conventional method.
As the component (A), a polyol and an organic polyisocyanate are reacted to produce an isocyanate group-containing compound, a compound obtained by reacting this with a hydroxyl group-containing (meth) acrylate (hereinafter referred to as “compound A1”), a polyol, Examples thereof include a compound obtained by reacting an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate at the same time (hereinafter referred to as “compound A2”), and the compound A1 is preferable because the molecular weight is easily controlled.
In the case of producing compound A1, in the presence of a urethanization catalyst such as dibutyltin dilaurate, the polyol and organic polyisocyanate to be used are heated and stirred for addition reaction, and further hydroxyalkyl (meth) acrylate is added, and heated and stirred for addition reaction. Examples of the method for producing compound A2 include a method in which a polyol, an organic polyisocyanate and a hydroxyalkyl (meth) acrylate are simultaneously added and heated and stirred in the presence of the same catalyst as described above.

  A catalyst for urethanization can be added to these reactions. Specific examples include tin compounds such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate and dibutyltin diacetylacetonate, bismuth compounds such as bismuth dioctate, and calcium compounds such as calcium dioctate.

These reactions can be carried out without solvent or in the presence of a solvent.
Specific examples of the solvent include hydrocarbon solvents such as n-hexane, benzene, toluene, xylene, ethylbenzene and cyclohexane; tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, bis (2-methoxy Ether solvents such as ethyl) ether, bis (2-ethoxyethyl) ether and bis (2-butoxyethyl) ether; acetone, methyl ethyl ketone, methyl-n-propyl ketone, diethyl ketone, butyl methyl ketone, methyl isobutyl ketone, methyl Ketone solvents such as pentyl ketone, di-n-propyl ketone, diisobutyl ketone, holon, isophorone, cyclohexanone and methylcyclohexanone; propylene glycol mono Ethyl acetate, butyl acetate and like esters; alkylene glycol monoether acetates, such as chill ether acetate and N- methylpyrrolidone and the like.
Of these, methyl ethyl ketone and methyl isobutyl ketone are particularly preferable from the viewpoints of solubility of urethane (meth) acrylate and easiness of evaporation.

  A reactive diluent can be used in place of the solvent in order to reduce the viscosity of urethane (meth) acrylate. Specifically, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, 1-adamantyl (meth) acrylate, methyl (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (Meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (Meth) acrylate, benzyl (meth) acrylate, allyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, о-phenylphenol EO modified (n = 1 to 4) (meth) acrylate, p-cumylphenol EO-modified (n = 1-4) (meth) acrylate, phenyl (meth) acrylate, о-phenylphenyl (meth) acrylate, p-cumylphenyl (meth) acrylate, N- (meth) acryloylmorpholine, N-vinylformamide, N- (meth) acryloyloxyethyl hexahydrophthalimide, N- (meth) acryloyloxyethyl tetrahydrophthalimide and the like can be mentioned.

2-1-5. Preferred component (A) In the present invention, as the component (A), among those described above, a diol having a P-Mn of 500 or more (hereinafter collectively referred to as “diol a”) and a P-Mn of less than 500 Urethane (meth) acrylate which is a reaction product of diol (hereinafter collectively referred to as “diol b”), non-yellowing organic diisocyanate and hydroxyl group-containing (meth) acrylate is preferable.
Compared to other urethane (meth) acrylates, the component (A) has a mechanical strength by using a long-chain diol diol a, a short-chain diol diol b, and a non-yellowing type organic diisocyanate. It is excellent and the yellowing degree after the light resistance test is small, and the photoelastic coefficient of the cured product of the composition can be low.
Examples of the diol a include the aforementioned polycarbonate diol and polyester diol, and examples of the diol b include the above-described aliphatic diol having 2 to 12 carbon atoms and alicyclic diol having 2 to 12 carbon atoms.
These diols a and b may be used alone or in combination of two or more.

The ratio of diols a and b is preferably diol a: 0 to 50 mol% and diol b: 50 to 100 mol%, more preferably diol a: 0 to 40 mol% and diol b: 60 to 100 mol%. is there.
Further, when triol is used in combination, the ratio of triol is preferably the sum of diols a and b: 50 to 100 mol% and triol: 0 to 50 mol%, more preferably diol a and / or b: 60. ˜100 mol% and triol: 0 to 40 mol%.

  As the component (A), as described above, the diol a and the diol b and a non-yellowing organic diisocyanate are reacted to produce an isocyanate group-containing compound, and a compound obtained by reacting this with a hydroxyl group-containing (meth) acrylate ( Compound A-I), diol a and diol b, non-yellowing organic diisocyanate, and compound (compound A-II) in which a hydroxyl group-containing (meth) acrylate is reacted at the same time, and the like, because the molecular weight is easy to control. A-I is preferred.

Furthermore, in the present invention, as the component (A), among the above-described compounds, a reaction product of a caprolactone adduct of diol b (a diol having a P-Mn of less than 500), a non-yellowing organic diisocyanate, and a hydroxyl group-containing (meth) acrylate Particularly preferred is urethane (meth) acrylate.
In the component (A), the cured product of the composition is excellent in brittleness and flexibility.
In this case, the diol b is preferably a polyol having a P-Mn of 60 or more and 400 or less.
Specific examples of the compound include aliphatic diols having 2 to 6 carbon atoms such as 1,4-butanediol, tricyclo [5.2.1.0 ^2,6 ] decandimethanol, and 3,9-bis (1 , 1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane and other alicyclic diols having a plurality of rings are preferable, and the strength of the cured product is excellent. 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane (common name; spiroglycol) is particularly preferred.
As the caprolactone adduct of hydroxyl group-containing (meth) acrylate, a caprolactone adduct of hydroxyalkyl (meth) acrylate is preferred. Furthermore, the reaction ratio of caprolactone to hydroxyl group-containing (meth) acrylate is preferably greater than 0.1 mol and less than 2.0 mol.
The production method of the component (A) may be carried out in the same manner as described above, and the preferred production method is also the same as described above.

2-2. Other Components The composition used in the present invention preferably contains the component (A) as an essential component, but various components can be blended depending on the purpose.
Hereinafter, other components will be described.
Specifically, a polymer having a photoelastic coefficient of 5 × 10 ⁻¹² Pa ⁻¹ or less (hereinafter referred to as “component (B)”) and a homopolymer other than the component (A) have a glass transition temperature of 0 ° C. Ethylenically unsaturated compound having the above [hereinafter referred to as “component (C)”], (A) component and ethylenically unsaturated compound other than component (C) [hereinafter referred to as “component (D)”], photopolymerization Examples include initiators (hereinafter referred to as “component (E)”), organic solvents (hereinafter referred to as “component (F)”), plasticizers, polymerization inhibitors or / and antioxidants, light resistance improvers, and the like. it can.
Hereinafter, these components will be described.

2-2-1. Component (B) The component (B) is a polymer having a photoelastic coefficient of 5 × 10 ⁻¹² Pa ⁻¹ or less.
The cured product of the component (A) usually has a positive photoelastic coefficient in the range of 10 × 10 ⁻¹² to 30 × 10 ⁻¹² Pa ⁻¹ , so that the photoelastic coefficient is 5 × 10 ⁻¹² Pa ⁻¹ or less. By mix | blending with a certain (B) component, the photoelastic coefficient of hardened | cured material can be 1 * 10 < ^-12 > ^-10 * 10 <^-12> Pa < ^{-1 >} .

The photoelastic coefficient of the component (B) 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 × 10 ⁻¹² to ⁻² × 10 ⁻¹² Pa ⁻¹ .

  As the component (B), various compounds can be used as long as the polymer has the photoelastic coefficient as described above, and a homopolymer or copolymer of a monomer having a (meth) acryloyl group, N-vinyl-2-pyrrolidone copolymer. Examples thereof include a polymer, a homopolymer or copolymer of α-methylstyrene, and an ethylene-tetracyclododecene copolymer.

  As the monomer having a (meth) acryloyl group, specifically, (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) ) Acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, glycidyl (meth) acrylate and other (meth) acrylates; 2-hydroxyethyl (meth) ) Acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate and other hydroxyl group-containing (meth) acrylates; N- (meth) acryloylmorpho Acrylamides such as (meth) acrylamide, N-methylol acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide and N, N-dimethylaminopropyl (meth) acrylamide Can be mentioned.

As a copolymer of a monomer having a (meth) acryloyl group, a copolymer having an amide structure or a carboxyl group is preferable in that it has a large negative photoelastic coefficient value and is excellent in compatibility with the component (A).
In the copolymer having an amide structure, the amide structure is preferably a morpholine structure. As a specific example of the copolymer having an amide structure, a copolymer of methyl (meth) acrylate and / or t-butyl (meth) acrylate and N- (meth) acryloylmorpholine is preferable.
As a specific example of the copolymer having a carboxyl group, a copolymer of methyl (meth) acrylate and acrylic acid or methacrylic acid is preferable.

A commercially available thing can also be used as a homopolymer or copolymer of the monomer which has a (meth) acryloyl group. For example, Delpet 60N, 80N (Asahi Kasei Chemicals Co., Ltd.), Dianal BR52, BR80, BR83, BR85, BR87, BR88 (Mitsubishi Rayon Co., Ltd.), KT75 (Electric Chemical Co., Ltd.), etc. Can be mentioned.
Dianal is a copolymer of monomers having a (meth) acryloyl group, and BR83, BR87 and BR88 are commercially available copolymers having a carboxyl group.

In the N-vinyl-2-pyrrolidone copolymer, examples of the copolymerizable monomer of N-vinyl-2-pyrrolidone include vinyl acetate and alkyl (meth) acrylate.
Specific examples of the N-vinyl-2-pyrrolidone copolymer include vinyl pyrrolidone / vinyl acetate copolymer, vinyl pyrrolidone / methyl (meth) acrylate copolymer, vinyl pyrrolidone / ethyl (meth) acrylate copolymer, vinyl A pyrrolidone butyl (meth) acrylate copolymer etc. can be mentioned.

A commercially available N-vinyl-2-pyrrolidone copolymer can also be used.
For example, PVP / VA S-630 [manufactured by asp Japan Co., Ltd.] and the like can be mentioned.

  The Mw of the component (B) is preferably 1,000 to 100,000 in terms of excellent compatibility with the component (A).

  There is no restriction | limiting in particular as a manufacturing method of (B) component, Any of well-known methods, such as suspension polymerization, emulsion polymerization, block polymerization, or solution polymerization, may be used using the above-mentioned monomer. . Here, as a polymerization initiator, a normal peroxide type and an azo type can be used, and a redox type can also be used.

  Regarding the polymerization temperature, suspension or emulsion polymerization may be performed at 30 to 100 ° C, and bulk or solution polymerization may be performed at 80 to 300 ° C. Furthermore, although polymerization can be carried out using alkyl mercaptan or the like as a chain transfer agent, it is preferable that the amount used is small in order to reduce the photoelastic coefficient.

As the component (B) in the present invention, a polymer having an ethylenically unsaturated group (hereinafter referred to as “(UB) component”) can be used, and the compatibility with the component (A) and the brittleness of the cured product are improved. And since it can increase (B) component content, it is preferable at the point that a photoelastic coefficient can further be reduced.
Hereinafter, the (UB) component will be described.

As the (UB) component (UB) component, various compounds can be used as long as the photoelastic coefficient is 5 × 10 ⁻¹² Pa ⁻¹ or less and the polymer has an ethylenically unsaturated group. Mention may be made of the polymers shown.
1) Polymer B1: Polymer containing carboxyl group (hereinafter referred to as “carboxyl group-containing prepolymer”) and / or polymer containing hydroxyl group (hereinafter referred to as “hydroxyl group-containing prepolymer”), isocyanate group and ethylene Polymer 2 obtained by adding a compound having a polymerizable unsaturated group (hereinafter referred to as “isocyanate-based unsaturated compound”) 2) Polymer B2: Compound having an epoxy group and an ethylenically unsaturated group on a carboxyl group-containing prepolymer Polymer 3 obtained by adding (hereinafter referred to as “epoxy unsaturated compound”) Polymer B3: Polymer containing epoxy group (hereinafter referred to as “epoxy group-containing prepolymer”), carboxyl group and ethylenic property Obtained by adding a compound having an unsaturated group (hereinafter referred to as “carboxyl unsaturated compound”) Polymer

◇ Prepolymer production method The carboxyl group-containing prepolymer used in the production of the polymer B1 and the polymer B2 includes a carboxyl-based unsaturated compound and other ethylenically unsaturated compounds (hereinafter referred to as "other unsaturated compounds"). And a polymer containing a carboxyl group at the terminal obtained by polymerizing another unsaturated compound in the presence of a chain transfer agent having a carboxyl group (hereinafter referred to as a terminal carboxyl group-containing polymer).
Hereinafter, the manufacturing method of a carboxyl group-containing prepolymer, a hydroxyl group-containing prepolymer, and an epoxy group-containing prepolymer will be described.

-Manufacturing method of carboxyl group-containing prepolymer First, the copolymer of a carboxyl type unsaturated compound and other unsaturated compounds is demonstrated.

Examples of carboxyl unsaturated compounds include (meth) acrylic acid, modified polycaprolactone of (meth) acrylic acid, and carboxyl groups such as monohydroxyethyl (meth) acrylate phthalate and monohydroxyethyl (meth) acrylate succinate ( And (meth) acrylate.
Among these, (meth) acrylic acid is preferably used because the photoelastic coefficient of the component (B) obtained is particularly low.

Other unsaturated compounds are not particularly limited as long as the photoelastic coefficient of the component (B) to be obtained is 5 × 10 ⁻¹² Pa ⁻¹ or less, but excellent in copolymerizability with the above-described carboxyl-based unsaturated compound. To (meth) acryloyl group-containing compounds are preferred.
As a compound having a (meth) acryloyl group, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl ( (Meth) acrylates such as (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, glycidyl (meth) acrylate;
N- (meth) acryloylmorpholine;
Acrylamides such as (meth) acrylamide, N-methylolacrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide and N, N-dimethylaminopropyl (meth) acrylamide; and (meth) Examples include acrylonitrile.
If necessary, compounds other than the compound having a (meth) acryloyl group can also be used, and examples thereof include styrene, α-methylstyrene, and vinyl acetate.

  Among these, it is preferable to use methyl (meth) acrylate and N- (meth) acryloylmorpholine because the photoelastic coefficient of the component (B) obtained is particularly low.

The prepolymer may further be a copolymer of a compound having a hydroxyl group and an ethylenically unsaturated group (hereinafter referred to as a “hydroxy unsaturated compound”).
Hydroxyl unsaturated compounds include hydroxyl group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and hydroxyhexyl (meth) acrylate, And hydroxyalkyl vinyl ethers such as hydroxybutyl vinyl ether.

There is no restriction | limiting in particular as a manufacturing method of the copolymer of a carboxyl type unsaturated compound and another unsaturated compound, The same manufacturing method as the said (E) component can be mentioned using an above described compound.
Among these, the solution polymerization method is preferable because the polymer can be easily produced and does not contain extra impurities such as an emulsifier.

Next, the manufacturing method of a terminal carboxyl group containing polymer is demonstrated.
Examples of the method for producing the terminal carboxyl group-containing polymer include a method of polymerizing other unsaturated compounds in the presence of a chain transfer agent having a carboxyl group.
Other unsaturated compounds include the same compounds as described above, and the same compounds as described above are preferable.
Examples of the chain transfer agent having a carboxyl group include 3-mercaptopropionic acid and mercaptoacetic acid.
The ratio of the chain transfer agent having a carboxyl group may be appropriately set according to the ratio of the ethylenically unsaturated group to be finally introduced, and is 0.01 to 100 parts by weight based on the total of 100 parts by weight of all monomers used. 7 parts by weight is preferred.
As the polymerization method, the same method as described above can be employed.

-Production method of hydroxyl group-containing prepolymer The hydroxyl group-containing prepolymer used in the polymer B1 is a copolymer of a hydroxy unsaturated compound and other unsaturated compounds, and other unsaturated compounds in the presence of a chain transfer agent having a hydroxyl group. Examples thereof include a polymer containing a hydroxyl group at the terminal obtained by polymerizing the compound (hereinafter referred to as “terminal hydroxyl group-containing polymer”).

Examples of the hydroxy unsaturated compound include the same compounds as described above.
Other unsaturated compounds include the same compounds as described above, and the same compounds as described above are preferable.

  As a manufacturing method of the copolymer of a hydroxyl-type unsaturated compound and another unsaturated compound, it can manufacture in accordance with the method similar to the above.

Next, the manufacturing method of a terminal hydroxyl group containing polymer is demonstrated.
Examples of the method for producing a terminal hydroxyl group-containing polymer include a method of polymerizing other unsaturated compounds in the presence of a chain transfer agent having a hydroxyl group.
Other unsaturated compounds include the same compounds as described above, and the same compounds as described above are preferable.
Examples of the chain transfer agent having a hydroxyl group include 2-mercaptoethanol.
What is necessary is just to set suitably as a ratio of the chain transfer agent which has a hydroxyl group according to the ratio of the ethylenically unsaturated group finally introduce | transduced, 0.01-7 parts with respect to a total of 100 weight part of all the monomers to be used. Part by weight is preferred.
As the polymerization method, the same method as described above can be employed.

-Manufacturing method of epoxy-group-containing prepolymer As an epoxy-group-containing prepolymer used with polymer B3, the copolymer of an epoxy-type unsaturated compound and another unsaturated compound is mentioned.

Examples of the epoxy unsaturated compound include epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate and cyclohexene oxide-containing (meth) acrylate.
Other unsaturated compounds include the same compounds as described above, and the same compounds as described above are preferable.

  As a manufacturing method of the copolymer of an epoxy unsaturated compound and other unsaturated compounds, it can manufacture according to the method similar to the above.

-Manufacturing method of (UB) component (UB) component has the functional group and ethylenically unsaturated group which can react with these prepolymer with respect to a carboxyl group-containing prepolymer, a hydroxyl group-containing prepolymer, and an epoxy group-containing prepolymer. It is introduced by addition reaction of the compound.
The addition reaction may be carried out in accordance with a conventional method, and it can be produced in an organic solvent or without a solvent. As conditions for the addition reaction, the reaction temperature, reaction time, and catalyst may be appropriately selected according to each reaction.

○ Ratio of component (B) As the component (B), only one kind of the aforementioned compounds may be used, or two or more kinds may be used in combination.
The proportion of the component (B) may be appropriately set according to the purpose, but the component (A) is 30 to 99% by weight based on the total amount of the component (B) and the component (B), and the component 1 (B). -70 weight% is preferable, More preferably, (A) component 40-90 weight% and (B) component 10-60 weight%.
By making the ratio of the component (A) 30% by weight or more, the cured product obtained can be excellent in mechanical properties, and by making it 99% by weight or less, the photoelastic coefficient is further reduced. Can do.

2-2-2. Component (C) Component (C) is an ethylenically unsaturated compound having a homopolymer glass transition temperature of 0 ° C. or higher.
In the component (C), examples of the ethylenically unsaturated group include a (meth) acryloyl group, a vinyl group, a vinyl ether group, and the like, and a (meth) acryloyl group is preferable.

As the component (C), various compounds can be used as long as they have an ethylenically unsaturated group and the homopolymer has a Tg of 0 ° C. or higher. A compound having one (meth) acryloyl group (hereinafter referred to as “component (C)”) , “Monofunctional (meth) acrylate”), compounds having two or more (meth) acryloyl groups (hereinafter referred to as “polyfunctional (meth) acrylate”), (meth) acrylamide compounds, fumaric acid esters, malees Examples include acid esters, allyl compounds, and vinyl compounds.
Monofunctional (meth) acrylates include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butyl (meth) acrylate, pentyl methacrylate, isopentyl methacrylate, neopentyl (meth) acrylate, cyclohexyl (Meth) acrylate, isobornyl (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and the like.
As polyfunctional (meth) acrylates, alkylene glycol di (meth) such as ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate Acrylate;
Glycol di (meth) acrylates such as 1,6-hexanediol di (meth) acrylate and neopentyl glycol di (meth) acrylate;
Dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa ( Polyol poly (meth) acrylates such as (meth) acrylate;
Examples include poly (meth) acrylates of alkylene oxide adducts of polyols; and di- or tri (meth) acrylates of isocyanuric acid alkylene oxides.
Examples of the (meth) acrylamide compound include N- (meth) acryloylmorpholine, N, N-dimethyl (meth) acrylamide, N-isopropylacrylamide, and N, N-dimethylaminopropyl (meth) acrylamide.
Examples of the fumaric acid ester include dimethyl fumarate, diethyl fumarate, diisopropyl fumarate and dibutyl fumarate.
Examples of allyl compounds include glycerin monoallyl ether, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, and isocyanuric acid triallyl.
Examples of the vinyl compound include N-vinylpyrrolidone, 4-vinylcyclohexene, vinyl acetate and the like.

As the component (C), among the above-described compounds, compounds having tertiary and quaternary carbon atoms are preferable because they have a low photoelastic coefficient.
Here, the tertiary carbon atom is a carbon atom in which one hydrogen atom and three atoms other than a hydrogen atom are bonded, and the quaternary carbon atom is a carbon atom in which four atoms other than a hydrogen atom are bonded. Means.
Specific examples of the compound include monofunctional (meth) acrylates such as isopropyl methacrylate, isobutyl methacrylate, t-butyl (meth) acrylate, isopentyl methacrylate, neopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) ) Acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, 1-adamantyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and the like. Polyfunctional (meth) acrylates include neopentyl glycol di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (Meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate; poly (meth) acrylate of an alkylene oxide adduct of the above polyol; and di- or tri (meth) acrylate of isocyanuric acid alkylene oxide, etc. Is mentioned.
Examples of the (meth) acrylamide compound include N-isopropylacrylamide.
Examples of the fumaric acid ester include diisopropyl fumarate and dibutyl fumarate.
Examples of maleic acid esters include diisopropyl malate.
4-vinylcyclohexene is mentioned as a vinyl compound.

  Furthermore, among these, in particular, isobutyl methacrylate (Tg of homopolymer: 67 ° C.), t-butyl (meth) acrylate (Tg of homopolymer of acrylate: 41 ° C., Tg of homopolymer of methacrylate: 107 ° C., hereinafter parentheses , 3,3,5-trimethylcyclohexyl (meth) acrylate (acrylate homopolymer Tg: 81 ° C.) and isobornyl (meth) acrylate (acrylate homopolymer Tg: 94 ° C., methacrylate) (Tg: 180 ° C.) is more preferable in terms of good mechanical properties and less coloration after heat treatment.

As the component (C), among the compounds described above, a compound having an aliphatic cyclic skeleton or a compound having a saturated cyclic skeleton containing a hetero atom is preferable because it has a low photoelastic coefficient.
Specific examples of the compound include cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and dicyclopentenyl (meth) acrylate. Monofunctional (meth) acrylate having an aliphatic cyclic skeleton; polyfunctional (meta) having an aliphatic cyclic skeleton such as dimethylol tricyclodecane di (meth) acrylate and poly (meth) acrylate of an alkylene oxide adduct of the polyol. ) Acrylate; 2-propionic acid (5-ethyl-1,3-dioxane-5-yl) methyl ester and 2-methyl-2-propionic acid (5-ethyl-1,3-dioxane-5-yl) methyl ester Having a saturated cyclic skeleton containing oxygen atoms such as No monofunctional (meth) acrylate: and N- (meth) acrylate saturated cyclic skeleton monofunctional containing a (meth) acrylate containing a nitrogen atom such as acryloyl morpholine.

  Among these, in particular, 2-propionic acid (5-ethyl-1,3-dioxane-5-yl) methyl ester (Tg of homopolymer: 10 ° C.), 3,3,5-trimethylcyclohexyl (meth) acrylate (Tg of acrylate homopolymer: 81 ° C.), isobornyl (meth) acrylate (Tg of acrylate homopolymer: 94 ° C., Tg of methacrylate homopolymer: 180 ° C.) and N- (meth) acryloylmorpholine (acrylate homo Polymer Tg: 145 ° C.) is more preferable in terms of good mechanical properties.

  As the component (C), only one kind of the aforementioned compounds may be used, or two or more kinds may be used in combination.

  The proportion of the component (A) and the component (C) may be appropriately set according to the purpose, but the amount of the component (A) is 30 to 90% by weight based on the total amount of the component (A) and the component (C), and 70 to 10 weight% of (C) component is preferable, More preferably, it is 50 to 80 weight% of (A) component and 50 to 20 weight% of (C) component.

2-2-3. Component (D) Component (D) is an ethylenically unsaturated compound other than components (A) and (C).
(D) A component is a component mix | blended as needed for the purpose of reducing the viscosity of the whole composition and adjusting the other physical properties.

  Specific examples of the component (D) include (meth) acrylates other than the components (A) and (C) [hereinafter referred to as “other (meth) acrylates”], N-vinyl-2-pyrrolidone, and the like.

  Other (meth) acrylates include a compound having one (meth) acryloyl group (hereinafter referred to as “monofunctional (meth) acrylate”) and a compound having two or more (meth) acryloyl groups [hereinafter referred to as “multiple”. Functional (meth) acrylate ”and the like.

  Specific examples of the monofunctional (meth) acrylate include 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl ( (Meth) acrylate, diethylaminoethyl (meth) acrylate, benzyl (meth) acrylate, allyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, о-phenylphenol EO modification (n = 1 to 1) 4) (meth) acrylate, p-cumylphenol EO modified (n = 1 to 4) (meth) acrylate, phenyl (meth) acrylate, о-phenylphenyl (meth) acrylate, p-cumylphenyl (meth) a Examples thereof include acrylate, N-vinylformamide, N- (meth) acryloyloxyethyl hexahydrophthalimide, N- (meth) acryloyloxyethyl tetrahydrophthalimide and the like.

Specific examples of the polyfunctional (meth) acrylate include bisphenol A EO-modified (n = 1 to 2) di (meth) acrylate, bisphenol A di (meth) acrylate, diethylene glycol di (meth) acrylate, and triethylene glycol di (meth). ) Acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol (n = 5-14) di (meth) acrylate, dipropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol (n = 5-14) Di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, polybutylene glycol (n = 3-16) di (meth) acrylate, Po Li (1-methylbutylene glycol) (n = 5 to 20) di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, spiroglycol di (meth) ) Bifunctional (meth) acrylate of acrylate.
In the above, EO modification means ethylene oxide modification, and n means the number of repeating alkylene oxide units.

  As the component (D), only one of the aforementioned compounds may be used, or two or more may be used in combination.

  The proportion of the component (D) may be appropriately set according to the purpose, and may be an amount that does not decrease the flexibility of the resulting cured product, but the total amount of the component (A) is 100 parts by weight. When (B) component and (C) component are included, 1 to 100 weight% is preferable with respect to 100 weight part of total amounts of (A) component, (B) component, and (C) component, More preferably 1 to 80% by weight.

2-2-4. (E) component (E) component is a photoinitiator.
(E) A component is a component mix | blended when an ultraviolet-ray and visible light are used as an active energy ray. When an electron beam is used as the active energy ray, it is not always necessary to add it, but a small amount can be added as necessary in order to improve curability.

(E) Component includes benzyl dimethyl ketal, benzyl, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl phenyl ketone, 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- (methylvinyl) phenyl] Propanone, 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl] -2-methylpropan-1-one, 2-methyl-1- [4- (methylthio) )] Phenyl] -2-morpholinopropan-1-one, 2- Nediru 2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-yl-phenyl) -butane-1 -Aromatic ketone compounds such as ON, Adekaoptomer N-1414 (manufactured by ADEKA), phenylglyoxylic acid methyl ester, ethyl anthraquinone, phenanthrenequinone;
Benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 4- (methylphenylthio) phenylphenylmethane, methyl-2-benzophenone, 1- [4- (4-Benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis ( Benzophenone compounds such as diethylamino) benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone, N, N′-tetraethyl-4,4′-diaminobenzophenone and 4-methoxy-4′-dimethylaminobenzophenone ;
Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl- (2,4,6-trimethylbenzoyl) phenylphosphinate and bis (2, Acylphosphine oxide compounds such as 6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide;
Thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propylthioxanthone, 3- [3,4-dimethyl-9-oxo-9H-thioxanthone-2-yl] oxy]- Thioxanthone compounds such as 2-hydroxypropyl-N, N, N-trimethylammonium chloride and fluorothioxanthone;
Acridone compounds such as acridone, 10-butyl-2-chloroacridone;
1,2-octanedione 1- [4- (phenylthio) -2- (O-benzoyloxime)] and ethanone 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] Oxime esters such as -1- (O-acetyloxime);
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-methoxyphenyl) -4,5-diphenylimidazole dimer, 2 2,4,5-triarylimidazole such as 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer and 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer Dimer; and acridine derivatives such as 9-phenylacridine and 1,7-bis (9,9'-acridinyl) heptane.

  (E) As a component, these compounds can also use 1 type (s) or 2 or more types together.

(E) As a compounding ratio of a component, when it contains the said (B) component and (C) component with respect to a total of 100 weight part of (A) component, (A) component, (B) component, and ( C) 0.01-10 weight% is preferable with respect to 100 weight part of total amounts of a component, More preferably, it is 0.1-5 weight%.
By setting the blending ratio of the component (E) to 0.01% by weight or more, the composition can be cured with an appropriate amount of ultraviolet light or visible light, and the productivity can be improved. By doing, it can be made the thing excellent in the weather resistance and transparency of hardened | cured material.

2-2-5. Component (F) The composition of the present invention preferably contains an organic solvent as the component (F) for the purpose of improving the coating property to the substrate.

Specific examples of the component (F) include hydrocarbon solvents such as n-hexane, benzene, toluene, xylene, ethylbenzene, and cyclohexane;
Methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, 2-methoxyethanol, 2-ethoxyethanol, 2- (methoxymethoxy) ethanol, 2-isopropoxyethanol, 2-butoxy Ethanol, 2-isopentyloxyethanol, 2-hexyloxyethanol, 2-phenoxyethanol, 2-benzyloxyethanol, furfuryl alcohol, tetrahydrofurfuryl alcohol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, 1 -Methoxy-2-propanol, 1-ethoxy-2-propanol and propylene glycol monomethyl Alcohol solvents such as ether;
Ether solvents such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, bis (2-methoxyethyl) ether, bis (2-ethoxyethyl) ether and bis (2-butoxyethyl) ether;
Acetone, methyl ethyl ketone, methyl-n-propyl ketone, diethyl ketone, butyl methyl ketone, methyl isobutyl ketone, methyl pentyl ketone, di-n-propyl ketone, diisobutyl ketone, phorone, isophorone, cyclopentanone, cyclohexanone, methylcyclohexanone, etc. Ketone solvents;
Ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, methyl glycol acetate, propylene glycol monomethyl ether acetate, cellosolve acetate;
Examples include aprotic polar solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone and γ-butyrolactone.

As the component (F), one or more of the aforementioned compounds can be used.
As an organic solvent, you may add separately and may use it as it is, without isolate | separating the organic solvent used by urethane (meth) acrylate manufacture.

  The proportion of the component (F) may be set as appropriate, but is preferably 10 to 90% by weight, more preferably 40 to 80% by weight in the composition.

2-2-6. For the purpose of imparting flexibility to the cured plasticizer and improving brittleness, a plasticizer can be added. Specific examples of the plasticizer include dialkyl phthalates such as dioctyl phthalate and diisononyl phthalate, dialkyl esters of adipic acid such as dioctyl adipate, phosphate esters such as sebacic acid ester, azelaic acid ester and tricresyl phosphate, polypropylene Examples thereof include liquid polyether polyols such as glycol, liquid polyester polyols such as polycaprolactone diol and 3-methylpentanediol adipate.
The blending ratio of these plasticizers may be set as appropriate. When the component (B) and the component (C) are included with respect to 100 parts by weight of the total component (A), the component (A), ( 5-30 weight% is preferable with respect to 100 weight part of total amounts of B) component and (C) component, More preferably, it is 5-20 weight%.
When the blending ratio of the plasticizer is 5% by weight or more, flexibility is exhibited, and when it is 30% by weight or less, toughness is maintained.

2-2-7. Polymerization inhibitor or / and antioxidant It is preferable to add a polymerization inhibitor or / and an antioxidant to the composition of the present invention because the storage stability of the composition of the present invention can be improved.
As the polymerization inhibitor, hydroquinone, hydroquinone monomethyl ether, 2,6-di-tert-butyl-4-methylphenol, and various phenolic antioxidants are preferable. A secondary antioxidant or the like can also be added.
When the total blending ratio of these polymerization inhibitors or / and antioxidants includes the component (B) and the component (C) with respect to a total of 100 parts by weight of the component (A), the component (A), It is preferable that it is 0.001 to 3 weight% with respect to 100 weight part of total amounts of (B) component and (C) component, More preferably, it is 0.01 to 0.5 weight%.

2-2-8. The composition of the light resistance improver present invention, the light resistance improving agent such as an ultraviolet absorber or a light stabilizer may be added.
Examples of the ultraviolet absorber include 2- (2′-hydroxy-5-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) benzotriazole, 2- (2 Benzotriazole compounds such as'-hydroxy-3'-t-butyl-5'-methylphenyl)benzotriazole;
Triazine compounds such as 2,4-bis (2,4-dimethylphenyl) -6- (2-hydroxy-4-iso-octyloxyphenyl) -s-triazine;
2,4-dihydroxy-benzophenone, 2-hydroxy-4-methoxy-benzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2, 4, 4 ' -Trihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3', 4,4'-tetrahydroxybenzophenone, or 2,2 Examples include benzophenone compounds such as'-dihydroxy-4,4'-dimethoxybenzophenone.
Examples of the light stabilizer include N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) -N, N′-diformylhexamethylenediamine, bis (1,2,6,6). -) Pentamethyl-4-piperidyl) -2- (3,5-ditertiarybutyl-4-hydroxybenzyl) -2-n-butylmalonate, bis (1,2,2,6,6-pentamethyl-4- Low molecular weight hindered amine compounds such as piperidinyl) sebacate; N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) -N, N′-diformylhexamethylenediamine, bis (1,2 Hindered amine light stabilizers such as high molecular weight hindered amine compounds such as 2,6,6-pentamethyl-4-piperidinyl) sebacate.
The blending ratio of the light fastness improver includes the component (A), the component (B), and the component (C) when the component (B) and the component (C) are included with respect to 100 parts by weight of the component (A). ) It is preferably 0 to 5% by weight, more preferably 0 to 1% by weight, based on 100 parts by weight of the total component.

3. Optical Film The optical film of the present invention is an optical film containing a cured product (film-like cured product) of the composition on at least one surface of the resin film (NR).
As a structure of an optical film, the optical film of the following structure etc. which laminated | stacked one layer of hardened | cured material on the resin film (NR) etc. are mentioned.
Resin film (NR) / cured product In addition to this, an optical film having the following constitution in which two resin film (NR) layers are laminated between cured product layers, and the like can be given.
Resin film (NR) / Hardened product / Resin film (NR)

The photoelastic coefficient of the optical film is preferably −5 × 10 ^{−12 to} 5 × 10 ⁻¹² Pa ⁻¹ , more preferably −3 × 10 ^{−12 to} 3 × 10 ⁻¹² Pa ⁻¹ . By setting the photoelastic coefficient of the optical film within this range, it is possible to obtain a liquid crystal display free from fear of light leakage or white spots.

The optical film is composed of a resin film (NR) in which a cured product of the composition is directly formed, and a resin film (NR) in which the cured product of the composition is bonded via an adhesive or the like. Etc.
As an optical film, a resin film (NR) in which a cured product of the composition is directly formed is preferable because it can reduce contamination and reduce the film thickness as compared to bonding via an adhesive or the like. .

The selection of the type and thickness of the resin film (NR) and the selection of the type of composition and the film thickness of the cured product may be appropriately set according to the purpose.
Preferably, the photoelastic coefficient (RP) and thickness (RT) of the resin film (NR) are set, and the photoelastic coefficient (CP) and thickness (CT) of the cured product of the composition satisfy the following formula (1). It is preferable.
By satisfy | filling the said Formula (1), the optical film obtained can be made into the preferable photoelastic coefficient mentioned above. Furthermore, if the formula (1) is calculated in advance, the photoelastic coefficient of the obtained optical film can be obtained by selecting what kind and thickness of the resin film (NR) and the composition, respectively. Can be predicted.

4). Method for Producing Optical Film A method for producing a cured product of the composition directly on the resin film (NR), which is a preferred embodiment of the optical film, will be described.
In the following, a part will be described with reference to FIG.

As a method for producing the optical film, various methods can be adopted depending on the purpose.
Specifically, a method of applying a composition to a resin film (NR) and irradiating it with an active energy ray and curing the composition, after applying the composition to a resin film (NR) and bonding it to another substrate, The method of irradiating and curing an active energy ray etc. are mentioned.
In this case, the other substrate may be a resin film (NR) or another resin film (hereinafter referred to as “other resin film”).
Other resin films include polyvinyl alcohol resin films, cellulose acetate resin films such as triacetyl cellulose and diacetyl cellulose, and the like.

In coating the composition, the composition of the resulting optical film is stirred and mixed in order to prevent the introduction of foreign substances, the occurrence of defects such as voids, and the excellent optical properties. After that, it is preferable to use a purified product.
As a method for purifying the composition, a method of filtering the composition is simple and preferable. Examples of the filtration method include pressure filtration.
The filtration accuracy is preferably 10 μm or less, more preferably 5 μm or less. The lower the filtration accuracy, the better. However, if the filter accuracy is too small, the filter is likely to be clogged, and the filter replacement frequency increases and the productivity is lowered. Therefore, the lower limit is preferably 0.1 μm.

  The coating method may be appropriately set according to the purpose, and conventionally known bar coat, applicator, doctor blade, knife coater, comma coater, reverse roll coater, die coater, lip coater, gravure coater, micro gravure coater, etc. The method of coating with is mentioned.

Examples of the active energy rays include ultraviolet rays, visible rays, and electron beams. Among these, ultraviolet rays are more preferable in that they have been used in polarizing plate lines, and an electron beam is more preferable in terms of excellent heat resistance and light resistance of a cured product without necessarily including a photopolymerization initiator.
What is necessary is just to set suitably irradiation conditions, such as irradiation intensity | strength and a dose in active energy ray irradiation, according to the composition to be used, a base material, a purpose, etc.

FIG. 1 shows an example of a preferred method for producing an optical film composed of a resin film (NR) / cured product.
In FIG. 1, (1) means a resin film (NR).
When the composition is a solventless type (FIG. 1: F1), the composition is applied to a substrate [FIG. 1: (1)]. When the composition contains an organic solvent or the like (FIG. 1: F2), the composition is applied to a substrate [FIG. 1: (1)] and then dried to evaporate the organic solvent (FIG. 1: 1). -1).
By irradiating an active energy ray to the sheet in which the composition layer (2) is formed on the resin film (NR), an optical film composed of the resin film (NR) / cured product is obtained. The active energy ray is usually irradiated from the composition layer side, but can also be irradiated from the resin film (NR) side.

  The coating amount of the composition of the present invention may be appropriately selected according to the desired photoelastic coefficient, but it is applied so that the film thickness after drying an organic solvent or the like is 5 to 200 μm. Preferably, it is 10-100 micrometers.

When the composition contains an organic solvent or the like, it is heated and dried after coating to evaporate the organic solvent or the like.
As a heating / drying method, a method of passing through a furnace equipped with a heating device, or it can be carried out by blowing air,
The heating / drying conditions may be appropriately set according to the organic solvent used, and examples thereof include a method of heating to a temperature of 40 to 150 ° C.
As the composition after heating and drying, the proportion of the organic solvent is preferably 1% by weight or less.

  What is necessary is just to set suitably irradiation conditions, such as irradiation intensity | strength and a dose in active energy ray irradiation according to the composition to be used, a base material, the objective, etc.

5. Use of optical film The optical film of the present invention can be used for various optical uses. More specifically, a polarizer protective film for a polarizing plate, a support film for a prism sheet, a light guide film, and the like that are used in a liquid crystal display device and the like can be mentioned, and can be preferably used for a polarizer protective film.

  Hereinafter, a polarizing plate using a polarizer protective film (hereinafter simply referred to as “protective film”) made of the optical film of the present invention will be described.

-Polarizing plate A polarizing plate is the structure by which the protective film was laminated | stacked on the at least single side | surface of the polarizer.
As the polarizer, various materials can be used as long as they have a function of selectively transmitting linearly polarized light in one direction from natural light.
For example, an iodine polarizing film in which iodine is adsorbed and oriented on a polyvinyl alcohol film, a dye polarizing film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol film, and a dichroic dye is coated. Examples include a fixed coating type polarizer. These iodine-based polarizing films, dye-based polarizing films, and coating-type polarizers have a function of selectively transmitting linearly polarized light in one direction from natural light and absorbing linearly polarized light in the other direction. It is called a polarizer. Among these polarizers, it is preferable to use an absorption type polarizer having excellent visibility. The thickness of the absorption polarizer is preferably 5 to 40 μm.
The polarizing plate of the present invention is a polarizing plate in which the optical film of the present invention is laminated as a protective film on at least one surface of a polarizer, and is bonded by an adhesive.

Any adhesive can be used for the adhesive between the polarizer and the protective film in consideration of the respective adhesiveness.
Specific examples of the adhesive include polyvinyl alcohol-based aqueous adhesives, solvent-based pressure-sensitive adhesives (pressure-sensitive adhesives), solvent-based adhesives, hot-melt adhesives, and solventless adhesives. A solvent-based active energy ray-curable adhesive can be preferably used.
Examples of the active energy ray curable adhesive include a photo cation curable adhesive, a photo radical curable adhesive, and a hybrid adhesive that uses both photo cation curing and photo radical curing.
Examples of the photo cation curable adhesive include photo cation curable compounds such as epoxy compounds and oxetane compounds, and adhesives including a photo cation polymerization initiator.
Examples of the photo-radical curable adhesive include photo-radical curable compounds such as (meth) acrylates, vinyl ethers and vinyl compounds, and adhesives containing a photo-radical polymerization initiator.
Examples of the hybrid adhesive include an adhesive containing the above-described photocationic curable compound, photoradical curable compound, photocationic polymerization initiator, and photoradical polymerization initiator.

When it has a protective film on both surfaces of a polarizer, what has the protective film of this invention on both surfaces is the most preferable. However, if necessary, the protective film of the present invention can be used on one side, and a protective film other than the protective film of the present invention (hereinafter referred to as “other protective film”) can be used on the other side.
Examples of other protective films include cellulose acetate resin films such as triacetyl cellulose and diacetyl cellulose, acrylic resin films, polyester resin films, and cyclic polyolefin resin films containing cyclic olefins such as norbornene as monomers. Moreover, when using these as a protective film of a display side, the film which has phase difference may be sufficient.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the following, “parts” means parts by weight.

○ Production Example 1 [Production of component (A)]
In a 500 mL reaction vessel equipped with a stirrer, a thermometer, and a cooler, IPDI: 151.4 g as an isocyanate and 0.07 g of dibutyltin dilaurate as a catalyst were charged at room temperature, and these were placed in a nitrogen atmosphere containing 5% by volume of oxygen. While stirring, the liquid temperature was increased to 70 ° C.
As an alcohol solution, polycaprolactone triol as an alcohol solution [Placcel 303, P-Mn: 300] manufactured by Daicel Chemical Industries, Ltd .: 18.3 g, polycarbonate diol [Duranol T-5651 manufactured by Asahi Kasei Chemicals Corporation, number average molecular weight 1, 000]: 20.4 g, 1,4-butanediol: 28.2 g and MEK: 65.0 g of a mixed solution was added dropwise so that the internal temperature would be 75 ° C. or less, and then reacted at an internal temperature of 80 ° C. for 2 hours. It was.
Thereafter, 2-hydroxyethyl acrylate (hereinafter referred to as “HEA”): 61.6 g as a hydroxyl-containing acrylate, and 2,6-di-t-butyl-4-methylphenol (hereinafter referred to as “BHT”) as a polymerization inhibitor. : 0.07 g, MEK: 5.0 g, and dibutyltin dilaurate: 0.07 g of a mixed solution was added dropwise so that the internal temperature was 75 ° C. or lower, reacted for 3 hours, and an infrared absorption spectrum apparatus (FT-IR manufactured by Perkin Elmer) The spectrum was measured by Spectrum 100), it was confirmed that the isocyanate group was completely consumed, and a MEK solution (solid content 80%) containing urethane acrylate (hereinafter referred to as “UA-1”) was obtained.
The polystyrene-equivalent weight average molecular weight (hereinafter referred to as Mw) of UA-1 was 2,400 as a result of measurement by GPC (solvent: tetrahydrofuran, column: HSPgel HR MB-L manufactured by Waters).

○ Production Example 2 [Production of Component (A)]
In Production Example 1, a mixed solution of IPDI: 110.3 g and MEK: 50.0 g as isocyanate, spiroglycol as alcohol (SPG manufactured by Mitsubishi Gas Chemical Co., Ltd., hydroxyl value: 369 mgKOH / g, P-Mn: 304): 88.1 g and MEK (used for washing attached to the reaction vessel after addition of SPG powder): 21.5 g, HEA as hydroxyl-containing acrylate: 12.2 g and 1 mol of ε-caprolactone in 2-hydroxyethyl acrylate Product [FA1DDM manufactured by Daicel Co., Ltd.]: 72.8 g and MEK: A MEK solution containing solid urethane acrylate (hereinafter referred to as “UA-2”) (solid) except that the mixed solution was 5.0 g. 80%).
Mw of the obtained UA-2 was 2,300.

○ Production Example 3 [Production of Component (A)]
In Production Example 1, IPDI: 103.8 g and MEK: 50.0 g as isocyanate, SPG: 93.4 g as alcohol, Duranol T-5651: 35.4 g and MEK: 32.5 g (same purpose and T as Production Example 2) -5651), MEK containing urethane acrylate (hereinafter referred to as “UA-3”), except that a mixed solution of HEA: 29.9 g and MEK: 5.0 g was used as the hydroxyl-containing acrylate. A solution (80% solids) was obtained.
Mw of UA-3 obtained was 5,000.

○ Production Example 4 [Production of Component (B)]
In a 500 mL reaction vessel equipped with a stirrer, thermometer, and condenser, methyl methacrylate (hereinafter referred to as “MMA”): 7.0 g, N-acryloylmorpholine (hereinafter referred to as “ACMO”): 3.0 g, propylene glycol Monomethyl ether (hereinafter referred to as “PGM”): 78.0 g was charged 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 became constant, MMA: 63.0 g was consumed for 4 hours and ACMO: 27.0 g was applied for 3 hours. On the other hand, a polymerization initiator solution consisting of V-65 [2,2′-azobis-2,4-dimethylvaleronitrile, manufactured by Wako Pure Chemical Industries, Ltd.]: 9.0 g and MEK: 22.5 g Each was continuously fed over 5 hours.
As a result of aging for 2 hours while maintaining the internal temperature at 92 ° C. after completion of continuous supply, a solution (solid content 52%) containing a polymer having a negative photoelastic coefficient (hereinafter referred to as “LP-1”) was obtained. It was.
The obtained LP-1 had Mw of 6,600 and Mn of 2,000.

○ Production Example 5 [ Production of Polarizer]
A polyvinyl alcohol film having a thickness of 80 μm was swelled in a 30 ° C. water bath and then dyed in an aqueous iodine solution of 5 wt% (weight ratio: iodine / potassium iodide = 1/10). Then, it is immersed in an aqueous solution containing 3% by weight boric acid and 2% by weight potassium iodide, and further 5.5 times in an aqueous solution containing 4% by weight boric acid and 3% by weight potassium iodide at 55 ° C. After uniaxial stretching, it was immersed in a 5 wt% potassium iodide aqueous solution. Then, it dried for 1 minute in 70 degreeC oven, and obtained the 30-micrometer-thick polarizer (henceforth polarizer P).
About the obtained polarizer P, when the polarization degree and the single transmittance were measured using the spectrophotometer with a polarizing prism (Shimadzu Corporation UV-2200), it was 99.99% and 43.1%, respectively. there were.

○ Production Example 6 [ Production of UV-curable adhesive]
40 parts of bisphenol A diglycidyl ether (Japan Epoxy Resin Co., Ltd. jER807), 20 parts of tetrahydrofurfuryl acrylate (Osaka Organic Chemical Co., Ltd. THF-A), 4-hydroxylbutyl acrylate (Nippon Kasei Co., Ltd.) 4-HBA) 30 parts, isocyanuric acid ethylene oxide modified di and triacrylate (Toagosei Co., Ltd. Aronix M-313) 10 parts, photopolymerization initiator (hereinafter referred to as "photoinitiator") diphenyl-4- 6 parts of 50% by weight propylene carbonate solution (phenylthio) phenylsulfonium hexafluorophosphate (Sanapro CPI-100P) and 1 part of 1-hydroxy-cyclohexyl-phenyl-ketone (BASF Japan Irgacure 184) are put into a stainless steel container. Shi It was stirred until homogeneous with a magnetic stirrer, an ultraviolet curing adhesive (hereinafter, referred to as adhesive UVX) was obtained.

(1) Production Examples C1 to C6 (Production of Composition)
The components shown in Table 1 below were charged in a stainless steel container at the ratio shown in Table 1, and stirred with a magnetic stirrer while heating to obtain a composition.

The abbreviations in Table 1 mean the following.
DCPA: dimethylol-tricyclodecanediacrylate, light acrylate DCP-A manufactured by Kyoeisha Chemical Co., Ltd.
Dc1173: 2-hydroxy-2-methyl-1-phenylpropan-1-one, DAROCUR-1173 manufactured by BASF Japan

(2) Examples 1 to 8 and Comparative Examples 1 to 3 (Production of optical film by ultraviolet curing)
A film after drying the ultraviolet curable composition obtained in Production Examples C1 to C3 at 80 ° C. for 10 minutes (at 120 ° C. for 10 minutes when PGM is included) on a substrate of width 300 mm × length 300 mm Coating was performed with an applicator so that the thickness was as described in Table 2.
Thereafter, the composition layer was coated with a conveyor-type ultraviolet irradiation device (high pressure mercury lamp, lamp height 12 cm, 365 nm irradiation intensity 400 mW / cm ² (Fusion UV Systems Japan Co., Ltd. UV POWER). The conveyor speed was adjusted according to the measurement value of PUCK)), and an ultraviolet ray was irradiated with an integrated light quantity of 1,000 mJ / cm ² to obtain an optical film.
In addition, the corona treatment was performed on any of the substrates.
The photoelastic coefficient of the cured product alone is on a film “Lumirror 50-T60” (surface untreated polyethylene terephthalate film, thickness 50 μm, hereinafter referred to as “Lumirror”) having a width of 300 mm × a length of 300 mm manufactured by Toray Industries, Inc. In addition, a cured product was prepared under the same conditions as described above, and was measured by the method described later after peeling from Lumirror. The results are shown in Table 2.

(3) Examples 9 to 11 (Production of optical film by electron beam curing)
After drying the electron beam curable composition obtained in Production Examples C4 to C6 at 80 ° C. for 10 minutes (when PGM is included, 120 minutes at 120 ° C.) on a substrate having a width of 300 mm and a length of 300 mm. Coating was performed with an applicator so that the film thickness was as described in Table 2.
Thereafter, the composition layer is irradiated with an electron beam under the conditions of an acceleration voltage of 200 kV, a dose of 150 kGy (adjusted by a beam current and a conveyance speed), and an oxygen concentration of 300 ppm or less by an electron beam irradiation apparatus manufactured by NHV Corporation. An optical film was obtained.
In addition, the corona treatment was performed on any of the substrates.
Further, the photoelastic coefficient of the cured product alone was measured by the method described later after a cured product was prepared on a Lumirror having a width of 300 mm and a length of 300 mm under the same conditions as described above, and peeled from the Lumirror. The results are shown in Table 2.

[Photoelastic coefficient]
The optical films obtained in Examples and Comparative Examples were cut into 15 mm × 60 mm, and using an automatic birefringence meter (KOBRA-WR, manufactured by Oji Scientific Instruments Co., Ltd.), a five-point tension in the range of 0N to 10N at room temperature. The in-plane retardation value when σ was changed was measured, and the photoelastic coefficient was obtained from the slope of the approximate straight line prepared according to the following formula. The results are shown in Table 2.
Δn = C · σ [wherein, Δn represents stress birefringence, σ represents tension, and C represents a photoelastic coefficient. ]

[Formula (1) calculation]
The results calculated according to the following formula (1) are shown in Table 2.

The symbol in Formula (1) means the following.
RP: photoelastic coefficient of resin film (RP), RT: thickness of resin film (RP) CP: photoelastic coefficient of cured composition, CT: thickness of cured composition

PMMA: Polymethylmethacrylate [Sane durene manufactured by Kaneka Corporation, film thickness: 125 μm]
COP: Norbornene-based cycloolefin polymer [Zeonor ZF14, Nippon Zeon Co., Ltd., film thickness: 100 μm]

Examples 1 to 11 are optical films produced from the compositions of Production Examples C1 to C6, and are sufficient by laminating a base material having a negative photoelastic coefficient and a cured product having a positive photoelastic coefficient. It was possible to adjust to a low photoelastic coefficient. In addition, since this experiment uses a thick film base material for convenience, the film is also a thick film. However, the use of the thin film base material can reduce the thickness of the photoelastic coefficient adjusting cured product. The film can be made thin.
In contrast, Comparative Examples 1 to 3 are optical films produced from the compositions of Production Examples C1 to C3, but the photoelastic coefficient of the substrate is positive, so the photoelastic coefficient of the obtained film. Was larger than the photoelastic coefficient of the substrate.

(4) Examples P1 to P3 (Production of polarizing plate)
Using the optical film obtained in Examples 2, 4 and 7 as the polarizer protective film, the adhesive UVX was applied to both sides of the polarizer P with a film thickness of 5 μm, and the optical film was bonded together. Conveyor speed is adjusted by a conveyor-type ultraviolet irradiation device (high pressure mercury lamp, lamp height 15 cm, 365 nm irradiation intensity 370 mW / cm ² (measured value of UV POWER PUCK manufactured by Fusion UV Systems Japan Co., Ltd.)) Then, ultraviolet rays were applied with an integrated light amount of 220 mJ / cm ² to obtain a polarizing plate (width 100 mm × length 100 mm).
In addition, no corona treatment was performed on any of the polarizer protective films.

(Measurement of degree of polarization and single transmittance)
About the polarizing plate obtained by the Example and the comparative example, the polarization degree and the single-piece | unit transmittance were measured using the spectrophotometer with a polarizing prism (Shimadzu Corporation UV-2200). The results are shown in Table 3.

[Moisture and heat resistance of polarizing plate: Appearance]
The external appearance of the sample after leaving the polarizing plate obtained by the Example and the comparative example for 120 hours in a 60 degreeC90% RH constant temperature and humidity chamber was visually evaluated on the following references | standards. The results are shown in Table 3.
○: Deformation is not seen.
X: Deformation was observed.

[Moisture and heat resistance of polarizing plate: Iodine decolorization]
The samples obtained in Examples and Comparative Examples were visually evaluated according to the following criteria for the presence or absence of iodine decolorization of samples after being left in a constant temperature and humidity chamber at 60 ° C. and 90% RH for 120 hours. The results are shown in Table 3.
○: Iodine decolorization is not observed.
X: Iodine decolorization was seen.

  Examples P1 to P3 are polarizing plates using the optical films obtained in Examples 2, 4 and 7 which are the compositions of the present invention, the performance of the polarizer P is maintained, and the heat and moisture resistance is good. Met.

  As described in detail above, the optical film of the present invention is suitably used in a polarizer protective film application.

Claims (21)

At least one surface of a resin film or sheet (hereinafter referred to as “resin film (NR)”) having a negative photoelastic coefficient at 23 ° C. (hereinafter simply referred to as “photoelastic coefficient”),
A film-like or sheet-like cured product of an active energy ray-curable composition containing a urethane (meth) acrylate (A) having no aromatic group and having a weight average molecular weight of 1,000 to 15,000. An optical film or sheet comprising
Photoelastic coefficient of the cured product have a positive value,
An optical film or sheet in which the cured product is directly formed on the resin film (NR) without using an adhesive . The composition contains a polymer (B) having a photoelastic coefficient of 5 × 10 ⁻¹² Pa ⁻¹ or less, and the cured product has a photoelastic coefficient of 1 × 10 ⁻¹² to 10 × 10 ⁻¹² Pa ^−1. The optical film or sheet according to claim 1 . The optical film or sheet according to claim 2, wherein the component (B) is a homopolymer or copolymer of a monomer having a (meth) acryloyl group. The composition is a compound having an ethylenically unsaturated group having a glass transition temperature of 0 ° C. or higher of the homopolymer, and includes a compound (C) other than the component (A), and the photoelastic coefficient of the cured product is 1 ×. 10 ^-12 a to 10 × 10 ^-12 Pa ^-1, the optical film or sheet according to any one of claims 1 to 3. The optical film or sheet according to claim 4 , wherein the component (C) is a compound having tertiary and quaternary carbon atoms. The component (C), a compound or an optical film or sheet according to claim 4 or claim 5, wherein the compound having a saturated cyclic skeleton containing a hetero atom having an aliphatic cyclic skeleton. The optical film or sheet according to any one of claims 1 to 6 , wherein the resin film (NR) has a photoelastic coefficient of -10 x ^10-12 to ^-1 x ^10-12 Pa-1. The optical film or sheet according to any one of claims 1 to 7 , wherein the resin film (NR) is polymethyl methacrylate. The photoelastic coefficient (RP) and thickness (RT) of the resin film (NR) and the photoelastic coefficient (CP) and thickness (CT) of the cured film or sheet of the composition are expressed by the following formula (1). The optical film or sheet of any one of Claims 1-8 which satisfy | fills.

The optical film or sheet according to any one of claims 1 to 9 photoelastic coefficient of ^{-5 × 10 -12 ~5 × 10 -12} Pa -1. A polarizer protective film comprising the optical film or sheet according to claim 10 . A polarizing plate in which the polarizer protective film according to claim 11 is laminated on at least one surface of a polarizer formed of a polyvinyl alcohol-based resin, and the polarizer is attached to the polarizer protective film via an adhesive layer. A bonded polarizing plate. The resin film (NR) having a negative photoelastic coefficient contains a urethane (meth) acrylate (A) which is a compound having no aromatic group and has a weight average molecular weight of 1,000 to 15,000. After the application of the active energy ray-curable composition, the active energy ray is irradiated from the coated surface or the resin film (NR) side, and the photoelastic coefficient of the cured product has a positive value as the composition. The manufacturing method of the optical film or sheet which uses what has. The composition contains a polymer (B) having a photoelastic coefficient of 5 × 10 ⁻¹² Pa ⁻¹ or less, and the cured product has a photoelastic coefficient of 1 × 10 ⁻¹² to 10 × 10 ⁻¹² Pa ^−1. The method for producing an optical film or sheet according to claim 13 . The method for producing an optical film or sheet according to claim 14, wherein the component (B) is a homopolymer or copolymer of a monomer having a (meth) acryloyl group. The composition is a compound having an ethylenically unsaturated group having a glass transition temperature of 0 ° C. or higher of the homopolymer, and includes a compound (C) other than the component (A), and the photoelastic coefficient of the cured product is 1 ×. is ^{10 -12 ~10 × 10 -12 Pa -1} , the optical film or sheet producing method according to any one of claims 13 to claim 15. The method for producing an optical film or sheet according to claim 16 , wherein the component (C) is a compound having tertiary and quaternary carbon atoms. The method for producing an optical film or sheet according to claim 16 or 17, wherein the component (C) is a compound having an aliphatic cyclic skeleton or a compound having a saturated cyclic skeleton containing a hetero atom. The method for manufacturing an optical film or sheet according to any one of claims 13 to claim 18 photoelastic coefficient of ^{-10 × 10 -12 ~-1 ×} 10 -12 Pa -1 of the resin film (NR) . The method for producing an optical film or sheet according to any one of claims 13 to 19 , wherein the resin film (NR) is polymethyl methacrylate. The photoelastic coefficient (RP) and thickness (RT) of the resin film (NR), and the photoelastic coefficient (CP) and thickness (CT) of the cured film or sheet of the composition are expressed by the following formula (1). The method for producing an optical film or sheet according to any one of claims 13 to 20 , wherein the kind and thickness of the resin film (NR) and the kind and thickness of the composition are selected so as to satisfy the conditions.

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