JP6107056B2 - Active energy ray-curable composition for forming optical film or optical sheet - Google Patents

Description

The present invention relates to a plasticizer used for forming an optical film or sheet, a thermoplastic resin containing the plasticizer and an active energy ray-curable composition, and an optical film or sheet obtained from the composition. Belongs.
In the following, for the sake of convenience, unless otherwise specified, “optical film or sheet” is described as “optical film”. Further, acrylate or methacrylate is represented as (meth) acrylate.

In an optical film such as a polarizer protective film used for a liquid crystal display or the like or a retardation film that optically compensates for liquid crystal, a thermoplastic resin film such as a cellulose ester film or a polymethyl methacrylate film is generally used. Also, a three-dimensional crosslinked film is often used because of its excellent heat resistance and chemical resistance. Among them, there is a case of using a film that is radically cured by active energy rays because curing proceeds in a short time and productivity is high.
Among the active energy ray-curable compositions, a composition containing urethane (meth) acrylate is often used because it exhibits excellent mechanical properties.

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 of occurrence of birefringence change due to external force is represented by the absolute value of the photoelastic coefficient, but the cured film of cellulose ester and urethane (meth) acrylate used as a polarizer protective film has an absolute value of its photoelastic coefficient. The light leakage and white spots occur due to the generation of stress birefringence accompanying the polarizer contraction.
Furthermore, when the flexibility of the cured film of cellulose ester film and urethane (meth) acrylate is insufficient, a plasticizer may be added, but depending on the structure, the photoelastic coefficient of the film is large or the amount added is large. In some cases, there was a problem of bleeding out over time.

  In Patent Document 1, a cellulose ester film containing a cellulose ester and an acrylic polymer having a weight average molecular weight of 500 or more and less than 5,000 is disclosed. However, since an acrylic polymer having a molecular weight adjusted with a thiol chain transfer agent is used, there is a problem that the photoelastic coefficient is large. In addition, since the photoelastic coefficient of an acrylic polymer having an aromatic ring as a side chain is positive, when it is contained in a cured film of cellulose ester or urethane (meth) acrylate having a positive photoelastic coefficient, the photoelastic coefficient is further increased. There was a problem of getting bigger.

  Patent Document 2 discloses an optical film containing a transparent resin and an ester plasticizer having a weight average molecular weight of 600 to 2,000. However, since the photoelastic coefficient of the ester plasticizer having an aromatic ring is positive, when it is contained in a cured film of cellulose ester or urethane (meth) acrylate having a positive photoelastic coefficient, the photoelastic coefficient is further increased. There was a problem.

JP 2003-12859 A JP 2010-197547 A

An object of the present invention is easy to handle and flexible, excellent in breaking strength, active energy ray-curable composition for forming the low optical film of photoelastic coefficient, to provide an optical film obtained from the composition That is.

As a result of intensive studies to solve the above problems, the present inventors have determined that an acrylic polymer having a specific weight average molecular weight obtained by polymerization without using a thiol chain transfer agent is a plasticizer for forming an optical film. As effective.
That is, the present invention is an acrylic having a weight average molecular weight (hereinafter referred to as “Mw”) of 500 to 5,000 obtained by polymerizing a monomer containing (meth) acrylate without using a thiol chain transfer agent. Active energy rays for forming an optical film or optical sheet comprising a plasticizer for forming an optical film (hereinafter, simply referred to as “plasticizer”) comprising a polymer (A) [hereinafter referred to as “component (A)”] The present invention relates to a curable composition (hereinafter referred to as “AE curable composition”) .

As the component (A), a polymer having no aromatic group is preferable. The monomer contains an alkyl (meth) acrylate (a) having at least one alkyl group having 1 to 18 carbon atoms (hereinafter referred to as “monomer (a)”) as (meth) acrylate. Is preferred. Furthermore, the monomer (a) preferably contains methyl acrylate as an essential component.
Further, the component (A) is preferably a polymer obtained by continuously polymerizing a monomer containing (meth) acrylate at a temperature of 180 to 350 ° C.

As a method of using the plasticizer, an optical film-forming resin composition containing a plasticizer and a thermoplastic resin (B) other than the plasticizer (hereinafter referred to as “component (B)”) (hereinafter referred to as “thermoplastic resin composition”). Is preferable).
The resulting optical film preferably has a photoelastic coefficient at 23 ° C. (hereinafter simply referred to as “photoelastic coefficient”) of 10 × 10 ⁻¹² Pa ⁻¹ or less.
These ratios are preferably 1 to 35% by weight of plasticizer and 65 to 99% by weight of component (B) based on the total amount of plasticizer and component (B).

The present invention, (A) component and the urethane (meth) acrylate (C) [hereinafter referred to as "component (C)"] about including A E-curable composition.
As the component (C), a compound having no aromatic group is preferable, and a reaction product of a polyol, a non-yellowing organic polyisocyanate, and a hydroxyl group-containing (meth) acrylate is preferable.
The photoelastic coefficient of the cured product of the composition is preferably 10 × 10 ⁻¹² Pa ⁻¹ or less.
As these ratios, 1 to 35% by weight of the plasticizer and 65 to 99% by weight of the (C) component are preferable based on the total amount of the plasticizer and the (C) component.

As a method of using the thermoplastic resin composition, an optical film formed in a film shape or a sheet shape is preferable.
As a method for using the AE curable composition, an optical film in which a cured product of the composition is formed into a film is preferable.

As a method for producing an optical film using an AE curable composition, a method of irradiating an active energy ray from a coated surface side or a sheet-like substrate side after applying the AE curable composition to a sheet-like substrate. Is preferred.
As the sheet-like substrate, a peelable substrate is preferable.
As an optical film manufacturing method using another AE curable composition, after applying an AE curable composition to a sheet-like substrate and pasting another sheet-like substrate on the coated surface of the composition The production method of irradiating active energy rays from either side of the sheet-like substrate is preferable.
As the sheet-like base material, a base material from which either one or both can be peeled is preferable.

According to A E-curable composition of the present invention can be obtained optical film is excellent in flexibility and breaking strength, and having a low photoelastic coefficient.

FIG. 1 shows an example of production of an optical film using the AE curable composition of the present invention. FIG. 2 shows an example of the production of an optical film using the AE curable composition of the present invention.

The present invention relates to a plasticizer used for forming a specific optical film or sheet, a thermoplastic resin composition and an active energy ray-curable composition containing the plasticizer, and an optical film or sheet obtained from the composition. It is.
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. Plasticizer TECHNICAL FIELD This invention relates to the plasticizer (plasticizer for optical film formation) which consists of (A) component.
Hereinafter, the component (A) which is the main component of the plasticizer of the present invention will be described.

1-1. Component (A) The component (A) is an acrylic polymer having an Mw of 500 to 5,000 obtained by polymerizing a monomer containing (meth) acrylate without using a thiol chain transfer agent.
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.
The “acrylic polymer” means a polymer having (meth) acrylate as an essential constituent monomer unit.

  As the component (A), an acrylic polymer having no aromatic group is preferable because it has a low photoelastic coefficient. An acrylic polymer having no aromatic group can be produced by using a compound having no aromatic group as a monomer.

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.

  (A) A component may use only 1 type or may use 2 or more types together.

As the component (A), an acrylic polymer having an Mw of 500 to 5,000 obtained by polymerizing a monomer containing (meth) acrylate without using a thiol-based chain transfer agent can be used in various heavy materials. Coalescence can be used.
Below, the manufacturing method of the monomer which is a raw material compound, and (A) component is demonstrated.

1-2. The monomer which is a raw material compound of the monomer (A) component includes (meth) acrylate.
As the (meth) acrylate, a polymer containing an alkyl (meth) acrylate having at least one alkyl group having 1 to 18 carbon atoms (hereinafter referred to as “monomer (a)”) is a plastic. This is preferable because of its high effect.
Specific examples of the monomer (a) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i- Butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, i-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) Examples include acrylate, i-nonyl (meth) acrylate, n-decyl (meth) acrylate, n-lauryl (meth) acrylate, and n-stearyl (meth) acrylate.
Among these, methyl acrylate is preferable in that it has an excellent balance between the plasticizing effect and the photoelastic coefficient reducing effect.

As the monomer, in addition to the monomer (a), it may be a copolymer of a monomer copolymerizable with the monomer (a) (hereinafter referred to as “other monomer”). good.
Other monomers include (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) Examples include acrylate, butoxyethyl (meth) acrylate, and vinyl acetate.

1-3. (A) Component Production Method (A) Component production method is a method in which a monomer is polymerized without using a thiol chain transfer agent, and the resulting polymer has an Mw of 500 to 5,000. If present, various polymerization methods can be employed.
The component (A) is obtained by continuously polymerizing the above monomer at a temperature of 180 to 350 ° C. because the above-mentioned Mw polymer can be obtained without using a thiol chain transfer agent. Is preferred.

  The high-temperature continuous polymerization can be carried out by a known method (for example, JP-T-57-502171, JP-A-59-6207, JP-A-60-215007, etc.). Specifically, after filling a pressurizable reactor with a solvent and setting it to a predetermined temperature under pressure, a monomer or a monomer mixture consisting of a polymerization solvent and a polymerization initiator as needed is fixed. And a method of withdrawing the reaction solution in an amount commensurate with the supply amount of the monomer mixture.

  When using a polymerization solvent, the solvent charged into the reactor at the start of the reaction and the solvent mixed in the monomer mixture may be the same or different. These solvents include aliphatic hydrocarbons, aromatic hydrocarbons such as toluene, xylene, cumene and ethylbenzene, cellosolves such as butyl cellosolve and glycol ethers such as carbitol, glymes such as ethylene glycol dimethyl ether, and diglymes such as diethylene glycol dimethyl ether. Ether, ethyl acetate, butyl acetate, cellosolve acetate, methyl propylene glycol acetate, acetate esters such as carbitol acetate and ethyl carbitol acetate, ketones such as acetone and methyl ethyl ketone, isopropyl alcohol, hexanol, decanol, ethylene glycol, propylene glycol and Fragrances such as aliphatic alcohols such as butylene glycol, benzyl alcohol and toluene alcohol Alcohol, and diethylene glycol, polyethylene glycol, dipropylene glycol, may be mentioned tripropylene glycol, polypropylene glycol, polyalkylene glycols such as tetramethylene glycol and polytetramethylene glycol. The use ratio of the polymerization solvent is preferably 200 parts by mass or less with respect to 100 parts by mass of the monomer mixture.

  In addition, a thermal polymerization initiator can be added to the monomer mixture as necessary, and the thermal polymerization initiator that can be used in this case is not particularly limited, but an azonitrile-based initiator and a peroxide. System initiators and the like. Azonitrile-based initiators include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile) and 2,2'-azobis (2,4-dimethylvaleronitrile) Examples of peroxide-based initiators include hydrogen peroxide, di-t-butyl peroxide, and benzoyl peroxide. As a compounding quantity in the case of mix | blending a thermal-polymerization initiator with a monomer mixture, it is preferable to set it as 0.001-5 mass parts with respect to 100 mass parts of monomer mixtures.

The polymerization temperature is 180 to 350 ° C, preferably 180 to 300 ° C, more preferably 160 to 250 ° C. At this polymerization temperature, an acrylic polymer having a relatively low molecular weight can be obtained without using a thiol chain transfer agent. When the polymerization temperature is lower than 180 ° C., a polymerization initiator and a chain transfer agent are required for the polymerization reaction. In this case, the polymer and the film are easily colored, and the photoelastic coefficient is increased when a chain transfer agent is used. On the other hand, when the polymerization temperature exceeds 350 ° C., a decomposition reaction tends to occur during the polymerization reaction, and the polymer is likely to be colored.
(A) As a component, although the polymer obtained by superposing | polymerizing without using a chain transfer agent is preferable, it is chain transfer agents other than a thiol type | system | group chain transfer agent, Comprising: The photoelastic coefficient of the obtained polymer is large. Any chain transfer agent that cannot be used can be used. Examples of the chain transfer agent include isopropyl alcohol.

  The pressure in the reactor does not affect the reaction and depends on the reaction temperature and the boiling point of the monomer mixture and solvent used, and any pressure can be used as long as the reaction temperature can be maintained. If necessary, pressurization with an inert gas such as nitrogen can be performed.

  The residence time is preferably 5 to 60 minutes. If the residence time is shorter than 5 minutes, the yield of the acrylic polymer may be low. If the residence time is longer than 60 minutes, the production efficiency of the acrylic polymer is lowered, and the polymer may be colored.

  A preferable production method of the acrylic polymer is a continuous polymerization method and a solution polymerization method. According to the bulk polymerization method, a polymer is produced with high productivity, and according to the solution polymerization method, the molecular weight and structure of the polymer can be easily controlled. Since these polymerizations are performed at a high temperature, an acrylic polymer having a small molecular weight distribution is produced. Of these, continuous polymerization using a stirred tank reactor is particularly preferable because a polymer having a small molecular weight distribution and composition distribution can be obtained.

  As the polymerization reaction, various methods such as bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization and the like can be applied, but bulk polymerization and solution polymerization are preferable because the reaction can be easily controlled.

In the high-temperature continuous polymerization, the component (A) containing an acrylic polymer having a double bond at its end is produced. The acrylic polymer having a double bond at the terminal is a plasticizer that has an excellent compatibility and is effective in producing a film that is difficult to stick to the surface.
The reason for this is presumed that the terminal double bond reacts with the thermoplastic resin in the film in the case of the thermoplastic resin composition, and urethane (meth) acrylate in the case of the AE curable composition. This is presumed to react with the (meth) acryloyl group.
The proportion of the acrylic polymer having a double bond at the end in the total acrylic polymer in the component (A) is preferably 20% by weight or more, and more preferably 40% by weight or more. This ratio is calculated from the number average molecular weight determined by GPC and the double bond concentration determined by the nuclear magnetic resonance spectrum. The average number of terminal double bonds per molecule of polymer is obtained by dividing the total number of terminal double bonds by the number of molecules of the polymer, and is hereinafter referred to as terminal double bond index.
The terminal double bond index in the component (A) is preferably 0.2 or more, more preferably 0.3 to 1.0.

2. Method of Using Plasticizer The plasticizer of the present invention can be suitably used for the purpose of plasticizing an optical film obtained by blending with a thermoplastic resin composition or an AE curable composition (active energy ray curable composition). .
Hereinafter, the thermoplastic resin composition and the AE curable composition will be described.

2-1. Thermoplastic Resin Composition When the plasticizer of the present invention is used in a thermoplastic resin composition, the component (B) (thermoplastic resin other than the plasticizer) includes cellulose ester resins, polymethyl methacrylate resins, and cyclohexane. Examples include olefinic resins.

The photoelastic coefficient of the obtained optical film is preferably 10 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 8 × 10 ⁻¹² Pa ⁻¹ or less. By using an optical film produced from a composition having a photoelastic coefficient within the above range, a liquid crystal display free from fear of light leakage or white spots can be obtained.

The proportion of the component (B) may be appropriately set according to the purpose, but the component (A) is 1 to 35% by weight and the component (B) 65 based on the total amount of the component (A) and the component (B). -99 weight% is preferable, More preferably, (A) component 1-25 weight% and (B) component 75-99 weight%.
(B) By making the ratio of a component 65weight% or more, the storage elastic modulus and glass transition temperature of the film obtained can be made high, and by making it 99 weight% or less on the other hand, A low photoelastic coefficient can be achieved.

The thermoplastic resin composition of the present invention preferably contains an organic solvent for the purpose of improving processability.
Specific examples, usage methods, blending ratios, and the like of the organic solvent will be described in the section of the optical film production method using the thermoplastic resin composition described later.

2-2. AE curable composition When the plasticizer of the present invention is used in an AE curable composition, the AE curable composition may be any of various compositions as long as it contains a compound having an ethylenically unsaturated group. Can be used.

  As the compound having an ethylenically unsaturated group, (meth) acrylates such as (meth) acrylate, vinyl compound and vinyl ether are preferable.

Furthermore, as the (meth) acrylate, because of excellent mechanical properties and the like of the cured product obtained, the component (C) [Urethane (meth) acrylate] is rather preferred, essential components of the present invention.
Hereinafter, the component (C) will be described.

2-2-1. Component (C) Examples of the component (C) include a reaction product of a polyol, an organic polyisocyanate, and a hydroxyl group-containing (meth) acrylate.
The component (C) is preferably a urethane (meth) acrylate having two or more (meth) acryloyl groups, and more preferably two (meth) acryloyl groups are urethane (meth) acrylates.
As the component (C), urethane (meth) acrylate having no aromatic group is preferable because of low photoelasticity. A urethane (meth) acrylate having no aromatic group can be produced by using a compound having no aromatic group as a raw material polyol and organic polyisocyanate.
(M) As Mw of a component, the thing of 1,000-15,000 is preferable, More preferably, it is 1,000-10,000.
(C) 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 (C), and the method for producing the component (C) will be described.

2-2-1-1. 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- Examples include 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, hydrogenated bisphenol-A, tricyclo [5.2.1.0 ^2,6 ] decanedimethanol (common name: tricyclodecanedimethanol), 1 , 4-decahydronaphthalenediol, 1,5-decahydronaphthalenediol, 1,6-decahydronaphthalenediol, 2,6-decahydronaphthalenediol, 2,7-decahydronaphthalenediol, decahydronaphthalenediol, Norbornanediol, norbornanedimethanol, decalindimethanol, 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-hydroxycyclohexyl) propane (common name; hydrogenated bisphenol A), 4,4'-dihydroxydicyclohexylmethane (common name; hydrogenated bisphenol F), 1,1-bis (4-hydroxycyclohexyl)- Examples thereof include alicyclic diols such as 1,1-dicyclohexylmethane (common name: hydrogenated bisphenol Z) and 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, a triol may be used in combination with 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 above-mentioned caprolactone adduct of triol is commercially available, and examples thereof include Plaxel 303, 305, 308, 312 and L320ML (manufactured by Daicel Corporation).

These polyols may be used alone or in combination of two or more.
(C) When a low photoelastic coefficient is requested | required as a component, it is more preferable to use C2-C12 aliphatic diol or C2-C12 alicyclic diol as said polyol.
As the component (C), when mechanical properties are required, more specifically, when excellent in breaking strength and tensile modulus are required, the number average molecular weight (hereinafter referred to as “P”) as a polyol is used 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.

2-2-1-2. 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.

2-2-1-3. Hydroxyl group-containing (meth) acrylate As hydroxyl group-containing (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate , Hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, pentaerythritol tri, di or mono (meth) acrylate, and hydroxyalkyl (meth) acrylate such as trimethylolpropane di or mono (meth) acrylate, and these compounds And caprolactone adducts.
Among the above-mentioned compounds, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferable in terms of excellent curability of the composition and optical properties of the cured product.

2-2-1-4. (C) Manufacturing method of component (C) Component may be manufactured according to the conventional method.
As the component (C), a polyol and an organic polyisocyanate are reacted to produce an isocyanate group-containing compound, and a compound obtained by reacting this with a hydroxyl group-containing (meth) acrylate (hereinafter referred to as “compound B1”), a polyol, A compound obtained by simultaneously reacting an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate (hereinafter referred to as “compound B2”) and the like are exemplified, and the compound A1 is preferable because the molecular weight is easily controlled.
In the case of producing compound B1, in the presence of a urethanization catalyst such as dibutyltin dilaurate, the polyol and organic polyisocyanate to be used are heated and stirred to carry out addition reaction, and further, hydroxyalkyl (meth) acrylate is added, and heated and stirred to carry out addition reaction. Examples of the method for producing compound B2 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.

2-2-1-5. Preferable component (C) In the present invention, as the component (C), 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 with other urethane (meth) acrylates, the component (C) has a mechanical strength by using a diol a which is a long-chain diol, a diol b which is a short-chain diol, and a non-yellowing type as an 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 (C), as described above, diol a and diol b and a non-yellowing organic diisocyanate are reacted to produce an isocyanate group-containing compound, which is then reacted with a hydroxyl group-containing (meth) acrylate. (Compound B-I), diol a and diol b, non-yellowing organic diisocyanate, and a compound (compound B-II) in which a hydroxyl group-containing (meth) acrylate is reacted at the same time, and the reason that the molecular weight is easy to control And compound BI is preferred.

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. , 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 (common name; spiroglycol) is particularly preferred.

The photoelastic coefficient of the cured product of the composition is preferably 10 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 8 × 10 ⁻¹² Pa ⁻¹ or less. By using an optical film manufactured from a photoelastic coefficient of the cured product within the above range, a liquid crystal display free from fear of light leakage or white spots can be obtained.

The proportion of the component (C) may be appropriately set according to the purpose, but the component (A) is 1 to 35% by weight and the component (C) 65 based on the total amount of the component (A) and the component (C). -99 weight% is preferable, More preferably, (A) component 1-25 weight% and (C) component 75-99 weight%.
(C) By making the ratio of a component 65 weight% or more, the storage elastic modulus and glass transition temperature of the film obtained can be made high, and by making it 99 weight% or less on the other hand, with the softness | flexibility of hardened | cured material, A low photoelastic coefficient can be achieved.

2-2-2. The other component AE curable composition contains the component (C) as an essential component, but various components can be blended depending on the purpose.
Specific examples of other components include compounds other than the (C) component having an ethylenically unsaturated group (hereinafter referred to as the (D) component), a photopolymerization initiator (hereinafter referred to as the (E) component), an organic solvent. [Hereinafter referred to as component (F)], polymerization inhibitors and / or antioxidants, light resistance improvers, and the like.
Hereinafter, these components will be described.

-(D) component (D) component is compounds other than (C) component which has an ethylenically unsaturated group.
(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 component (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 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, 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 4) (meth) acrylate, p-cumylphenol EO modified (n = 1 to 4) (meth) acrylate, phenyl (meth) acrylate, о-phenylphenyl (meth) acrylate, p-cumylphenyl (meta ) Acrylate, N- (meth) acryloylmorpholine, 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, ethylene glycol di (meth) acrylate, and diethylene glycol di (meth). Acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol (n = 5-14) di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) Acrylate, tripropylene 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 to 16) di (meth) acrylate, poly (1-methylbutylene glycol) (n = 5 to 20) di (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, Bifunctional (meth) acrylates such as dimethylol tricyclodecane di (meth) acrylate and spiroglycol di (meth) acrylate;
Trifunctional (meth) acrylates such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate ;
More than four functionalities such as pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate (Meth) acrylate and the like.
In the above, EO modification means an ethylene oxide adduct, 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.

As the component (D), among the above-mentioned compounds, polyfunctional (meth) acrylate is preferable because the storage elastic modulus and glass transition temperature of the cured product can be increased.
Furthermore, as polyfunctional (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, Ditrimethylolpropane tetra (meth) acrylate and the like are preferable.

When the cured product of the composition is used as a polarizer protective film, the component (D) is preferably a compound having a photoelastic coefficient of the homopolymer smaller than the component (D) among the above-mentioned compounds. Preferably, it is a compound in which the photoelastic coefficient of the homopolymer is negative.
Specific examples of the compound are particularly preferably isobornyl (meth) acrylate, t-butyl (meth) acrylate, N- (meth) acryloylmorpholine and N-vinyl-2-pyrrolidone.

The proportion of the component (D) may be appropriately set according to the purpose, but 50 to 99% by weight of the component (C) and component 1 of the component (D) based on the total amount of the component (C) and the component (D). -50% by weight is preferred, more preferably 60-99% by weight of component (C) and 1-40% by weight of component (D).
(D) By making the ratio of a component into 1 weight% or more, the storage elastic modulus and glass transition temperature of the hardened | cured material obtained can be made high, and the mechanical characteristic of hardened | cured material is made into the other 50 weight% or less. And flexibility.

-(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.

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

(E) As a compounding ratio of a component, 0.01-10 weight% is preferable with respect to 100 weight part of total amounts of (C) component and (D) component, More preferably, it is 0.1-5 weight%. is there.
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.

(F) Component The composition of the present invention preferably contains an organic solvent as the (F) component 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 manufacture of (C) component.

  The proportion of the component (F) may be set as appropriate, but is preferably 10 to 90% by weight, more preferably 20 to 80% by weight in the composition.

● Polymerization inhibitor or / and antioxidant It is preferable to add a polymerization inhibitor or / and an antioxidant to the composition of the present invention, which can improve the storage stability of the composition of the present invention. .
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.
The total blending ratio of these polymerization inhibitors or / and antioxidants is preferably 0.001 to 3% by weight, more preferably 100 parts by weight of the total amount of component (C) and component (D). Is 0.01 to 0.5% by weight.

-Light resistance improver You may add light resistance improvers, such as a ultraviolet absorber and a light stabilizer, to the composition of this invention.
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 is preferably 0 to 5% by weight, more preferably 0 to 1% by weight, based on 100 parts by weight of the total amount of the component (C) and the component (D).

3. Manufacturing method of optical film The manufacturing method of the optical film using the composition containing the plasticizer of this invention can employ | adopt various usage methods according to the composition to be used, the objective, etc.
About the manufacturing method of an optical film, the manufacturing method in the case of using a thermoplastic resin composition and an AE curable composition is each demonstrated below.

3-1. Production Method of Optical Film Using Thermoplastic Resin Composition When producing the optical film of the present invention using a thermoplastic resin composition, a known production method is possible. Specifically, it can be produced using a known film forming method such as a solution casting method (solution casting method), a melt extrusion method, a calendar method, and a compression molding method.
Among these, the solution casting method (solution casting method) and the melt extrusion method are preferable. Hereinafter, these production methods will be described.

3-1-2. Production of optical film by solution casting method In the case of solution casting method, a composition (solution) containing a plasticizer [component (A)] thermoplastic resin [component (B)] and an organic solvent is used as the thermoplastic resin composition. To do.
An optical film is manufactured by forming and drying the composition by a casting method.
As the solution casting method, a method including (1) a dissolving step, (2) a casting step, and (3) a drying step is preferable. Hereinafter, these steps will be described.

(1) Dissolution Step In the dissolution step, the (B) component and the (A) component are dissolved in an organic solvent mainly composed of a good solvent for the flaky (B) component in a dissolution vessel, A step of producing a solution of an organic solvent containing the component (A) and the component (B) (hereinafter referred to as “dope”), or a solution of the organic solvent containing the component (B) and a solution of the organic solvent containing the component (A). This is a process for producing a dope by mixing.

  For the dissolution of component (B), various dissolution methods such as a method performed at normal pressure, a method performed below the boiling point of the main solvent, and a method performed under pressure above the boiling point of the main solvent can be used. In particular, a method in which the pressure is applied at a temperature higher than the boiling point of the main solvent is preferred. The concentration of the component (B) in the dope is preferably 10 to 35% by weight. An additive excluding the matting agent is added to and dissolved in the dope during or after dissolution, and then filtered through a filter medium, defoamed, and sent to the next step with a liquid feed pump.

  As the organic solvent, a good solvent used in a solution casting method such as methylene chloride, methyl acetate or dioxolane can be used, and at the same time, a poor solvent such as methanol, ethanol or butanol may be used.

(2) Casting step The casting step is a step of casting a dope on a support to obtain a uniform film.

  Generally, if a deformation stress is applied in the film forming process, the orientation proceeds and the birefringence value of the film increases. As the birefringence value increases, it becomes difficult to maintain the uniformity of the film, and the variation in optical characteristics also increases. Therefore, it is desirable to form a film under a relatively low stress with a low viscosity. Further, it is preferable that the dope has a low viscosity because the film thickness is uniformed by the leveling effect after coating. The preferred viscosity of the solution is from 10 poise to 100 poise, more preferably from 15 poise to 70 poise. In addition, since it will flow out from a support body when it is lower than 10 poise, measures, such as providing a partition plate suitably, are needed.

  As a coating method, a die coater, a doctor blade coater, a roll coater, a comma coater, a lip coater, and the like are preferable, but various methods that are usually used are possible without being limited to these examples.

  As a preferable support, a metal support such as a stainless steel endless belt or a rotating metal drum, or a film such as a polyimide film or a biaxially stretched polyethylene terephthalate film can be used.

(3) Drying step The drying step is a step of heating a dope film cast on a support and evaporating the solvent to obtain a dry film.

  In the heat drying, in the state where the liquid film immediately after casting or coating is not dried, if there is an abrupt wind flow or heating, the thickness is likely to be uneven. That is, there are also means for preventing direct wind from being applied to the film or heating by applying microwaves instead of wind. It is also important to prevent sudden heating / cooling. Furthermore, since the dope film is foamed by the humidity in the atmosphere, the humidity control is also important. Thereafter, it is preferably dried so as to reduce the residual solvent by blowing hot air after the semi-solidified state.

  The drying after casting can be carried out while being supported on the support, but if necessary, the predried film can be peeled off from the support until it has self-supporting property, and further dried. In general, a float method, a tenter or a roll conveying method can be used for drying the film. In the case of the float process, the film itself is subjected to complicated stress, and optical characteristics are likely to be uneven. In the case of the tenter method, it is necessary to balance the film width shrinkage due to solvent drying and the tension to support its own weight depending on the distance between the pins or clips that support both ends of the film. There is a need. On the other hand, in the case of the roll conveyance method, since the tension for stable film conveyance is in principle applied to the film flow direction (MD direction), it has a characteristic that the direction of stress is easily made constant. Therefore, the film is most preferably dried by a roll conveyance method. Among them, in order to reduce the stress due to gravity, a vertical suspension path method in which a plurality of rolls are arranged up and down and the film is passed up and down and up and down is preferable because a long drying path can be secured while omitting the installation space of the oven. .

  Also, drying in an atmosphere kept at a low humidity so that the film does not absorb moisture when the solvent is dried is an effective method for obtaining a film having high mechanical strength and transparency.

3-1-2. Production of optical film by melt extrusion method In the case of the melt extrusion method, the component (B) and the plasticizer [component (A)] are pre-blended with a mixer such as an omni mixer and the resulting mixture is extruded from a kneader. This is a method for producing an optical film by kneading.
As a specific example of the melt extrusion method, the kneader used for extrusion kneading is not particularly limited. For example, a known kneader such as an extruder such as a single screw extruder or a twin screw extruder, or a pressure kneader may be used. Can be used.

  Examples of the melt extrusion method include a T-die method and an inflation method. The molding temperature in that case becomes like this. Preferably it is 200-350 degreeC, More preferably, it is 250-300 degreeC, More preferably, it is 255-300 degreeC, Most preferably, it is 260-300 degreeC.

  When the T-die method is used, an optical film wound into a roll can be obtained by attaching a T-die to the tip of the extruder and winding the film extruded from the T-die. At this time, it is also possible to control the temperature and speed of winding and to stretch (uniaxial stretching) in the extrusion direction of the film. Alternatively, the film may be stretched in a direction perpendicular to the extrusion direction, and sequential biaxial stretching or simultaneous biaxial stretching may be performed.

  When an extruder is used for extrusion molding, the type is not particularly limited and may be uniaxial, biaxial, or multiaxial, but its L / D value is (L is the value of the extruder) Cylinder length, D is cylinder inner diameter), in order to sufficiently plasticize the thermoplastic resin composition to obtain a good kneaded state, it is preferably 10 or more and 100 or less, more preferably 15 or more and 80 or less, More preferably, it is 20 or more and 60 or less. When the L / D value is less than 10, the thermoplastic resin composition may not be sufficiently plasticized and a good kneaded state may not be obtained. On the other hand, if the L / D value exceeds 100, the resin in the composition may be thermally decomposed due to excessive heat generation from the thermoplastic resin composition.

  In this case, the set temperature of the cylinder is preferably 200 to 350 ° C. or less, more preferably 250 to 300 ° C. or less. If setting temperature is less than 200 degreeC, the melt viscosity of a thermoplastic resin composition will become high too much, and the productivity of a resin film will fall. On the other hand, if the set temperature exceeds 350 ° C., the resin in the thermoplastic resin composition may be thermally decomposed.

  When an extruder is used for extrusion molding, the shape is not particularly limited, but the extruder preferably has one or more open vent portions. By using such an extruder, the decomposition gas can be sucked from the open vent portion, and the amount of volatile components remaining in the obtained resin film can be reduced. In order to suck the decomposition gas from the open vent portion, for example, the open vent portion may be in a reduced pressure state, and the degree of pressure reduction is preferably in the range of 931 to 1.3 hPa as the pressure of the open vent portion, 798 A range of ˜13.3 hPa is more preferable. When the pressure in the open vent is higher than 931 hPa, volatile components or monomer components generated by the decomposition of the resin are likely to remain in the thermoplastic resin. On the other hand, it is industrially difficult to keep the pressure of the open vent part lower than 1.3 hPa.

  In order to reduce defects in the appearance of the film, it is preferable to incorporate a filtration step such as filtration with a polymer filter. By incorporating the filtration step, foreign substances present in the thermoplastic resin composition can be removed.

  In addition, at the time of filtration with a polymer filter, a thermoplastic resin composition will be in a high temperature molten state. For this reason, when passing through the polymer filter, the thermoplastic resin composition deteriorates, gas components and colored deterioration products formed by the deterioration flow out into the composition, the resulting film is perforated, flow pattern, Defects such as flow streaks may be observed. This defect is particularly apt to be observed during the continuous forming of a film. Therefore, when molding a thermoplastic resin composition filtered through a polymer filter, the molding temperature decreases the melt viscosity of the component (B) and shortens the residence time of the component (B) in the polymer filter. For example, it is 255-350 degreeC, and 260-320 degreeC is preferable.

3-2. Method for producing optical film using AE curable composition As a method for producing an optical film using AE curable composition, the above-mentioned AE curable composition is applied to a substrate and irradiated with active energy rays. A method of curing by applying a composition to a substrate and bonding it to another substrate, and further irradiating and curing an active energy ray, pouring the composition into a mold having a recess, The method of irradiating and hardening is mentioned.
Examples of the active energy ray include a method of irradiating an electron beam, ultraviolet rays, visible rays and the like.

As the substrate, any of a peelable substrate and a substrate having no releasability (hereinafter referred to as “non-releasing substrate”) can be used.
Examples of the peelable substrate include a release-treated film and a surface untreated film having peelability (hereinafter collectively referred to as “release material”).
Examples of the release material include silicone-treated polyethylene terephthalate film, surface untreated polyethylene terephthalate film, surface untreated cycloolefin polymer film, and surface untreated OPP film (polypropylene).
In order to suppress the haze of the cured product of the composition of the present invention to 1.0% or less, it is preferable to use a surface untreated polyethylene terephthalate film or a surface untreated OPP film (polypropylene).

In order to achieve low haze or impart surface smoothness to the optical film obtained from the composition of the present invention, the surface roughness (centerline average roughness) Ra is 150 nm or less as a peelable substrate. It is preferable to use a material, and a base material of 0.001 to 0.100 μm is more preferable. Furthermore, the haze is preferably 3.0% or less.
Specific examples of the substrate include a surface untreated polyethylene terephthalate film and a surface untreated OPP film (polypropylene).
In the present invention, the surface roughness Ra means a value obtained by measuring the surface roughness of the film and calculating an average roughness.

  Examples of the non-releasable substrate include various plastics other than the above, cellulose acetate resins such as polyvinyl alcohol, triacetyl cellulose and diacetyl cellulose, acrylic resin, polyester, polycarbonate, polyarylate, polyethersulfone, norbornene and the like And cyclic polyolefin resins having a cyclic olefin as a monomer.

In coating the composition of the present invention, as a composition, in order to prevent the occurrence of foreign matters and the occurrence of defects such as voids in the obtained optical film, or to have excellent optical properties, the raw material components are used. It is preferable to use a purified product after stirring and mixing.
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 active energy rays include electron beams, ultraviolet rays, and visible rays. Among these, an electron beam is more preferable in that it is not always necessary to add a photopolymerization initiator and the cured product is excellent in heat resistance and light resistance.
What is necessary is just to set suitably irradiation conditions, such as a dose and irradiation intensity in active energy ray irradiation, according to the composition to be used, a base material, a purpose, etc.

3-2-1. More Specific Optical Film Manufacturing Method The optical film manufacturing method using the AE curable composition has been outlined above. Hereinafter, a more specific optical film manufacturing method will be described.
In the following, a part of the description will be given with reference to FIGS.

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

  The coating amount of the composition of the present invention may be appropriately selected according to the application to be used, but it is preferable that the coating is performed so that the film thickness after drying the 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 a dose and irradiation intensity in active energy ray irradiation, according to the composition to be used, a base material, a purpose, etc.

  FIG. 2 shows an example of a preferable method for producing an optical film composed of a release material / cured product / release material.

In FIG. 2, (1), (3), and (4) mean release materials.
When the composition is a solventless type (FIG. 2: F1), the composition is applied to a release material [FIG. 2: (1)]. When the composition contains an organic solvent or the like (FIG. 2: F2), the composition is applied to a release material [FIG. 2: (1)] and then dried to evaporate the organic solvent (FIG. 2: 2). -1). The composition layer (2) is laminated with the release material (3) and then irradiated with active energy rays, or after being irradiated with active energy rays, the release material (4) is laminated to obtain a release material, a cured product and a release material. An optical film formed in this order is obtained.

Although the example which used the mold release material as a base material was described in the said FIG. 1 and 2, an optical film can also be manufactured using a non-mold release base material.
For example, in FIG. 1, a non-releasable base material is used in place of the release material of (1) and is cured by irradiation with active energy rays in the same manner as described above, and is composed of a non-releasable base material / cured product. An optical film can also be manufactured.
Further, in FIG. 2, a non-releasing substrate is used as the release material of any of (1), (3) and (4), and cured by irradiation with active energy rays in the same manner as described above. An optical film composed of a release material / cured product / non-releasing substrate or an optical film composed of a non-releasing substrate / cured material / non-releasing substrate can also be produced.

  In the above example, the optical film is produced by applying the composition to a substrate. However, when producing an optical film having a large film thickness, the composition is formed on a mold having a specific recess. An optical film can also be produced by pouring an object and irradiating active energy rays in the same manner as described above to cure the composition.

4). Use of Optical Film The optical film produced from the plasticizer of the present invention and a composition containing the plasticizer can be used for various optical uses.
More specifically, a film used for a liquid crystal display device such as a polarizer protective film for a polarizing plate, a support film for a prism sheet, and a light guide film, and a touch panel integrated liquid crystal display device, various functional films (for example, hard coat) Films, decorative films, transparent conductive films) and surface films (for example, moth-eye type antireflection films and films with a texture structure for solar cells), light resistance for outdoor use such as solar cells (weather resistance) ) Applications such as films, films for LED lighting / organic EL lighting, and transparent heat-resistant films for flexible electronics.

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

Example 1 [Production of Component (A) (Plasticizer)]
First, a monomer mixed solution is prepared and stored in a raw material tank. The monomer mixed solution contains 2,000 g of methyl acrylate (hereinafter referred to as MA): 48 g, methyl ethyl ketone (hereinafter referred to as MEK): 48 g, and ditertiary butyl peroxide (hereinafter referred to as DTBP): 42 g.
Next, a 300 ml capacity pressurized stirred tank reactor equipped with an electric heater was filled with ethyl 3-ethoxypropionate. The temperature in the reactor was maintained at 240 ° C., and the pressure in the reactor was adjusted to 2.7 MPa by a pressure controller.
While keeping the reactor pressure constant, the monomer solution was continuously fed from the raw material tank to the reactor. At this time, the supply rate was set so that the residence time of the monomer solution in the reactor was 12 minutes. Specifically, the monomer solution was fed to the reactor at a constant feed rate (25 g / min). In addition, a reaction product having a volume equal to the supply volume of the monomer mixture was continuously withdrawn from the outlet of the reactor. Immediately after the start of the monomer mixture supply, the temperature in the reactor once decreased. Thereafter, the temperature in the reactor rose due to the heat of polymerization. The reaction temperature was maintained at 244 ° C. by controlling the heater. From the time when the reaction temperature was stabilized, recovery of the reaction solution was started (at the start of recovery). The reaction was continued for 60 minutes from the start of recovery. As a result, 2,180 g of the monomer mixed solution was supplied, and 2,130 g of the reaction solution was recovered.
The collected reaction liquid was introduced into a thin film evaporator. Under an atmosphere of 250 ° C. and 20 kPa, volatile components such as unreacted monomers and solvents were removed from the reaction solution. As a result, about 1.900 g of an acrylic polymer (hereinafter referred to as “PLA-1”) was obtained.
According to the results of gas chromatographic analysis of PLA-1, it was found that the unreacted monomer was 0.5% or less.
The polystyrene-converted weight average molecular weight (hereinafter referred to as Mw) of PLA-1 was 1,400 as a result of measurement by GPC (solvent: tetrahydrofuran, column: TSKgel SuperMultipore HZ-M manufactured by Tosoh Corporation).
The terminal double bond index was 0.4.

Example 2 [Production of Component (A) (Plasticizer)]
In Production Example 1, the monomer mixed solution was MA: 1,140 g, butyl acrylate: 860 g, MEK: 140 g, DTBP: 40 g, reactor internal pressure: 2.4 MPa, reactor internal temperature: 252 ° C. The same operation was performed except that the amount of the mixture liquid supply: 2,090 g and the amount of the reaction liquid recovered: 2,070 g, to obtain about 1.900 g of an acrylic polymer (hereinafter referred to as “PLA-2”). It was.
The unreacted monomer of PLA-2 obtained was 0.5% or less, Mw was 1,700, and the terminal double bond index was 0.5.

○ Production Example 1 [Production of Component (C)]
In a 500 mL reaction vessel equipped with a stirrer, a thermometer and a condenser, IPDI: 138.4 g as compound (C) at room temperature and 2,6-di-tert-butyl-4-methylphenol (hereinafter referred to as “polymerization inhibitor”). BHT ”): 0.07 g, dibutyltin dilaurate (hereinafter referred to as“ DBTDL ”): 0.07 g as a catalyst, and a liquid temperature of 70 ° C. with stirring in an atmosphere of nitrogen containing 5% by volume of oxygen. Heated until.
As compound (a), tricyclo [5.2.1.0 ^2,6 ] decandimethanol (TCDDM manufactured by Oxea) (hydroxyl value: 572 mgKOH / g, P-Mn: 196): 77.0 g, compound (c) As follows, a mixed solution of HEA: 54.6 g and MEK: 85.0 g was added all at once so that the internal temperature was 75 ° C. or lower, and then reacted at an internal temperature of 80 ° C. for 2 hours.
Then, a mixed solution of DBTDL: 0.07 g and MEK: 5.0 g was added, and the spectrum was measured with an infrared absorption spectrum apparatus (FT-IR Spectrum 100 manufactured by Perkin Elmer) to confirm that the isocyanate group was completely consumed. Then, a MEK solution (solid content 80%) containing urethane acrylate (hereinafter referred to as “UA-1”) was obtained.
It was 2,300 as a result of measuring the polystyrene conversion weight average molecular weight (henceforth Mw) of UA-1 by GPC (solvent: tetrahydrofuran, column: HSPgel HR MB-L made from Waters).

○ Production Example 2 [Production of Component (C)]
A 500 mL reaction vessel equipped with a stirrer, a thermometer, and a condenser was charged with IIPDI: 116.3 g and MEK: 50.0 g as compound (C) and DBTDL: 0.07 g as a catalyst at room temperature, and 5% by volume of oxygen was charged. The mixture was heated under stirring in a nitrogen atmosphere until the liquid temperature reached 70 ° C.
Spiroglycol (hydroxyl value: 369 mg KOH / g, P-Mn: 304) [Mitsubishi Gas Chemical Co., Ltd. SPG]: 100.3 g and MEK (SPG as powder) as a solution of compound (a) 32.5 g was added dropwise so that the internal temperature was 75 ° C. or lower, and then reacted at an internal temperature of 80 ° C. for 2 hours.
Thereafter, a mixed solution of HEA: 45.9 g as the compound (c) and BHT: 0.07 g, MEK: 5.0 g and DBTDL: 0.07 g as the polymerization inhibitor was added dropwise so that the internal temperature was 75 ° C. or lower. After 3 hours of reaction, it was confirmed that the isocyanate groups were completely consumed, and a MEK solution (solid content 80%) containing urethane acrylate (hereinafter referred to as “UA-2”) was obtained.
Mw of the obtained UA-2 was 2,300.

Comparative Example 1 [Production of Acrylic Polymer (Plasticizer) Other than Component (A)]
200 g of methyl acrylate was introduced into a flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer, an inlet, and a reflux condenser, and nitrogen gas was introduced to replace the inside of the flask with nitrogen gas. After adding 10 g of thioglycerol with stirring, polymerization was carried out for 4 hours while maintaining the temperature of the contents at 60 ° C.
The contents were returned to room temperature, and 40 g of a 5% by weight benzoquinone tetrahydrofuran solution was added thereto to stop the polymerization. The contents were transferred to an evaporator, and tetrahydrofuran, residual monomer and residual thioglycerol were removed under reduced pressure at 80 ° C. to obtain an acrylic polymer (hereinafter referred to as “PLA-3”).
The unreacted monomer of PLA-3 obtained was 0.5% or less, Mw was 2,100, and the terminal double bond index was 0.

(1) Reference Examples T1 to T2, Reference Comparative Examples T1 to T2 (production of thermoplastic resin 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.
BR84: Polymethylmethacrylate resin, Mitsubishi Rayon Co., Ltd. Dianal BR-84 [solid content 100%, Mw 120,000, acid value 6.5 mgKOH / g]

(2) Examples A1 to A8, Comparative Examples A1 to A5 (Production of AE curable composition)
Components shown in Table 2 below were charged into a stainless steel container in the proportions shown in Table 2, and stirred with a magnetic stirrer while heating to obtain a composition.

The abbreviations in Table 2 mean the following.
Dc1173: 2-hydroxy-2-methyl-1-phenylpropan-1-one, DAROCUR-1173 manufactured by BASF Japan

(3) Examples TF1 and TF2, Comparative Examples TF1 and TF2 (Production of optical film by solution casting method)
A film “Lumirror 50-T60” manufactured by Toray Industries, Inc., having a width of 300 mm × a length of 300 mm (surface untreated polyethylene terephthalate film, thickness 50 μm, hereinafter referred to as “Lumirror”), Examples T1 and T2, Comparative Example T1 and The composition obtained in the same T2 was coated with an applicator so that the film thickness after drying at 80 ° C. for 10 minutes was 40 μm to obtain an optical film.
After drying, it was peeled off from Lumirror and used for the evaluation described later. The results are shown in Table 3.

(4) Examples AF1 to AF3 and AF5 to AF8, Comparative Examples AF1 to AF3 and AF5 (production of optical film by electron beam curing)
Examples A1 to A3 and A5 to A5 are the same as the film “Lumirror 50-T60” (surface untreated polyethylene terephthalate film, thickness 50 μm, hereinafter referred to as “Lumirror”) manufactured by Toray Industries, Inc. having a width of 300 mm and a length of 300 mm The compositions obtained in A8, Comparative Examples A1 to A3 and A5 were coated with an applicator so that the film thickness after drying at 80 ° C. for 10 minutes was 40 μm.
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.
After curing, it was peeled off from Lumirror and used for the evaluation described later. The results are shown in Table 4.

(5) Example AF4, Comparative Example AF4 (Production of optical film by ultraviolet curing)
The UV curable composition obtained in Example A4 and Comparative Example A4 was applied to a Lumirror having a width of 300 mm and a length of 300 mm with an applicator so that the film thickness after drying at 80 ° C. for 10 minutes was 40 μm.
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 measured value of PUCK)) was used to adjust the conveyor speed, and ultraviolet irradiation with an integrated light quantity of 1,000 mJ / cm ² was performed to obtain an ultraviolet curable optical film.
After curing, it was peeled off from Lumirror and used for the evaluation described later. The results are shown in Table 3.

[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. ]

[Tensile test]
A 15 × 150 mm sample was cut out from the produced film, and a tensile test was performed under the following conditions using a tensile tester (Instron 5564 manufactured by Instron Japan Company Limited) in an atmosphere of 25% and 65% RH. The breaking strength and breaking elongation were measured. The results are shown in Table 3.
Distance between chucks: 100mm
Tensile speed: 50 mm / min

[Cutting]
The cutting property when the produced film was cut with a cutter knife was evaluated according to the following criteria. The results are shown in Table 3.
○: A state in which cutting can be performed smoothly △: Slightly lacking in smoothness ×: A state in which a cross-section is cracked during cutting

[Bending resistance]
The resistance when the film was cut into 15 × 150 mm and bent by 180 ° was evaluated according to the following criteria. The results are shown in Table 3.
○: No crack in 3 times △: Crack in 1 to 2 times ×: Crack in 1 time

Examples TF1 and TF2 are optical films obtained from the compositions of Examples T1 and T2, which are thermoplastic compositions containing the plasticizer of the present invention, having a low photoelastic coefficient, breaking strength and breaking elongation. It was excellent in balance of degree and excellent in flexibility.
On the other hand, since Comparative Example TF1 is an optical film produced from a composition containing no plasticizer, the film was very brittle, and the photoelastic coefficient and tensile test could not be evaluated. Comparative Example TF2 is an optical film produced from a composition containing a plasticizer whose molecular weight is adjusted using a thiol-based chain transfer agent, so it has an excellent balance of breaking strength and breaking elongation, and is excellent in flexibility. The photoelastic coefficient was higher than when the plasticizer of the present invention was included.

Examples AF1 to AF8 are optical films obtained from the compositions of Examples A1 to A8, which are AE curable compositions containing the plasticizer of the present invention, and have a low photoelastic coefficient, breaking strength and breaking strength. It was excellent in balance of elongation and excellent in flexibility.
On the other hand, since Comparative Examples AF1 and AF2 are optical films produced from a composition containing no plasticizer, the films were very fragile and the photoelastic coefficient and tensile test could not be evaluated. Comparative Examples AF3 to AF5 are optical films manufactured from a composition containing a plasticizer whose molecular weight is adjusted using a thiol-based chain transfer agent. Therefore, the balance of breaking strength and breaking elongation is excellent, and flexibility is achieved. Although excellent, the photoelastic coefficient was higher than when the plasticizer of the present invention was included.

  The plasticizer for forming an optical film of the present invention can be suitably used for the production of an optical film.

Claims (17)

The weight average molecular weight obtained by continuously polymerizing a monomer containing (meth) acrylate at a temperature of 180 to 350 ° C. without using a thiol chain transfer agent is 500 to 5,000 , and an aromatic group A plasticizer comprising an acrylic polymer (A) not having
An active energy ray-curable composition for forming an optical film or an optical sheet containing urethane (meth) acrylate (C) having no aromatic group . The said monomer contains the alkyl (meth) acrylate (a) (henceforth "monomer (a)") which has an at least 1 sort (s) of C1-C18 alkyl group as (meth) acrylate. 2. An active energy ray-curable composition for forming the optical film or optical sheet according to 1 . The active energy ray-curable composition for forming an optical film or an optical sheet according to claim 2, wherein the monomer (a) contains methyl acrylate as an essential component. The component (C), polyol, aliphatic organic diisocyanate and / or alicyclic organic diisocyanate, as well as according to any one of claims 1 to 3 which is a reaction product of a hydroxyl group-containing (meth) acrylate An active energy ray-curable composition for forming an optical film or an optical sheet. The activity for forming the optical film or optical sheet according to any one of claims 1 to 4 , wherein the photoelastic coefficient at 23 ° C of the cured product of the composition is 10 x 10 ^-12 Pa ^-1 or less. Energy ray curable composition. 1 to 35% by weight of plasticizer consisting of component (A) and 65 to 99% by weight of component (C) based on the total amount of plasticizer consisting of component (A) and component (C) Item 6. An active energy ray-curable composition for forming the optical film or the optical sheet according to any one of items 5 . The optical film or optical sheet in which the hardened | cured material of the composition of any one of Claims 1-6 is formed in a film form or a sheet form. After applying the composition of any one of Claims 1-6 to a sheet-like base material, the optical film or optical sheet which irradiates an active energy ray from the coating surface side or the sheet-like base material side Production method. The method for producing an optical film or optical sheet according to claim 8 , wherein the sheet-like substrate is a peelable substrate. After apply | coating the composition of any one of Claims 1-6 to a sheet-like base material, and bonding another sheet-like base material to the coating surface of a composition, the said sheet-like base material The manufacturing method of the optical film or optical sheet which irradiates an active energy ray from either side of these. The method for producing an optical film or optical sheet according to claim 10 , wherein either or both of the sheet-like base materials are peelable base materials.   A monomer containing (meth) acrylate is continuously polymerized at a high temperature of 180 to 350 ° C. without using a thiol chain transfer agent, and has a weight average molecular weight of 500 to 5,000 and an aromatic group. A step of producing a plasticizer comprising an acrylic polymer (A) that does not, and
Including a step of mixing the obtained plasticizer comprising the component (A) and urethane (meth) acrylate (C) having no aromatic group.
A method for producing an active energy ray-curable composition for forming an optical film or an optical sheet.   The manufacturing method of the active energy ray hardening-type composition for forming the optical film or optical sheet of Claim 12 in which the said monomer contains the said monomer (a).   The method for producing an active energy ray-curable composition for forming an optical film or an optical sheet according to claim 13, wherein the monomer (a) contains methyl acrylate as an essential component.   The component (C) is a reaction product of a polyol, an aliphatic organic diisocyanate or / and an alicyclic organic diisocyanate, and a hydroxyl group-containing (meth) acrylate, according to any one of claims 12 to 14. A method for producing an active energy ray-curable composition for forming an optical film or an optical sheet.   The photoelastic coefficient at 23 ° C. of the cured product of the composition is 10 × 10 ^-12 Pa ^-1 It is the following. The manufacturing method of the active energy ray hardening-type composition for forming the optical film or optical sheet of any one of Claims 12-15.   The plasticizer comprising the component (A) and the total amount of the component (C), based on the total amount of the plasticizer comprising the component (A) 1 to 35% by weight and the component (C) comprising 65 to 99% by weight. Item 18. A method for producing an active energy ray-curable composition for forming the optical film or the optical sheet according to any one of items 16.