JP2010128417A - Optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film excellent in heat-resistant stability and capable of performing uniform polarization conversion in a wide wavelength region. <P>SOLUTION: The optical film contains a resin comprising a structural unit derived from a compound which is obtained by allowing the compound obtained by allowing a polyisocyanate compound having an alicyclic hydrocarbon skeleton to react with a polyol compound, to react with a compound having an ethylenical double bond and a functional group that can react with an isocyanate group. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical film and the like.

The retardation value Re (ν) of light transmitted through the optical film at the wavelength νnm satisfies the relationship Re (450) <Re (550) <Re (650), and the dispersion is increased to the right in the entire visible region of 300 to 700 nm. , The optical film can perform uniform polarization conversion in a wide wavelength range. As an optical film having such properties, Pure Ace WR (registered trademark, manufactured by Teijin Chemicals) is known.
“Optical Film for Display”, CMC Publishing, February 2004, p. 97-107

  Conventional optical films sometimes have insufficient heat resistance stability. Therefore, the present inventors have found that an optical film having a specific structural unit is excellent in heat stability and is capable of uniform polarization conversion in a wide wavelength range, and has led to the present invention.

  In the present invention, a compound obtained by reacting a polyisocyanate compound having an alicyclic hydrocarbon skeleton and a polyol compound is further reacted with a compound having a functional group capable of reacting with an isocyanate group and an ethylenic double bond. It is an optical film containing resin which consists of a structural unit derived from the compound obtained in this way.

  In the present invention, the compound having a functional group capable of reacting with an isocyanate group and an ethylenic double bond is at least one compound selected from the group consisting of an acrylamide compound having a hydroxyl group and a methacrylamide compound having a hydroxyl group. It is an optical film.

Moreover, this invention is the said optical film with which phase difference value Re ((nu)) in wavelength (nu) nm of the transmitted light which permeate | transmits an optical film satisfies the following formula.
Re (450) <Re (550) <Re (650)

  Moreover, this invention is a phase difference plate which consists of said optical film.

  In the present invention, a compound obtained by reacting a polyisocyanate compound having an alicyclic hydrocarbon skeleton with a polyol compound is further reacted with a compound having a functional group capable of reacting with an isocyanate group and an ethylenic double bond. It is the manufacturing method of the optical film including the film-forming process which forms into a film the solution containing the compound obtained by making it extend | stretch, and the extending | stretching process which further stretches the obtained film | membrane.

  In addition, the present invention provides a compound obtained by reacting a polyisocyanate compound having an alicyclic hydrocarbon skeleton with a polyol compound, a functional group capable of reacting with an isocyanate group, and an ethylenic double bond. It is the manufacturing method of the said optical film which is a process of forming into a film by casting the solution containing the compound obtained by making the compound which has this react on a smooth surface, and distilling a solvent off.

  The optical film of the present invention has excellent heat stability and can perform uniform polarization conversion in a wide wavelength range.

Hereinafter, the present invention will be described in detail. An optical film refers to a film that can transmit light and has an optical function. The optical function means refraction, birefringence and the like.
In the present invention, the structural unit is a minimum unit that exhibits a predetermined birefringence, and means a unit derived from a (co) polymer or a compound. The monomer unit means a unit derived from the monomer constituting the (co) polymer.
In addition, when the layer obtained from the resin containing the predetermined structural unit is stretched, the predetermined birefringence is exhibited when the refractive index in the stretched direction (± 10 °) is maximum (positive) or orthogonal to the stretched direction. It means that the refractive index in the direction of (± 10 °) becomes maximum (negative) or the like.

  The (co) polymer includes both homopolymers and copolymers. (Meth) acrylic acid includes both acrylic acid and (meth) acrylic acid.

The optical film of the present invention reacts a polyisocyanate compound having an alicyclic hydrocarbon skeleton (hereinafter sometimes referred to as “alicyclic polyisocyanate”) and a polyol compound (hereinafter sometimes referred to as “polyol”). A structural unit derived from a compound obtained by further reacting the resulting compound with a compound having a functional group capable of reacting with an isocyanate group and an ethylenic double bond (hereinafter sometimes referred to as “compound (1)”). A resin comprising
The polyisocyanate compound is a compound containing two or more isocyanate groups, and the polyol compound is a compound having two or more hydroxyl groups.

  The functional group capable of reacting with an isocyanate group and the compound having an ethylenic double bond are selected from the group consisting of an acrylate compound having a hydroxyl group, a methacrylate compound having a hydroxyl group, an acrylamide compound having a hydroxyl group, and a methacrylamide compound having a hydroxyl group. It is preferably at least one compound, and particularly preferably at least one compound selected from the group consisting of an acrylamide compound having a hydroxyl group and a methacrylamide compound having a hydroxyl group.

As a structural unit derived from the compound (1),
A compound obtained by reacting an alicyclic polyisocyanate and a polyol (hereinafter sometimes referred to as “polyurethane”), and at least one selected from the group consisting of an acrylate compound having a hydroxyl group and a methacrylate compound having a hydroxyl group A structural unit derived from a compound obtained by reacting the above compound (hereinafter sometimes referred to as “polyurethane acrylate”);
Further, at least one compound selected from the group consisting of an acrylate compound having a hydroxyl group and a methacrylate compound having a hydroxyl group is added to a compound obtained by further reacting polyurethane with a polyamine (hereinafter sometimes referred to as “polyurethane urea”). A structural unit derived from a compound obtained by reacting with (hereinafter sometimes referred to as “polyurethane urea acrylate”);
A structure derived from a compound obtained by reacting polyurethane with at least one compound selected from the group consisting of an acrylamide compound having a hydroxyl group and a methacrylamide compound having a hydroxyl group (hereinafter sometimes referred to as “polyurethane acrylamide”). unit;
Further derived from a compound obtained by reacting polyurethane urea with at least one compound selected from the group consisting of an acrylamide compound having a hydroxyl group and a methacrylamide compound having a hydroxyl group (hereinafter sometimes referred to as “polyurethane urea acrylamide”). Structural unit to
Is mentioned.

The alicyclic polyisocyanate is preferably a compound containing a divalent group having an optionally substituted cyclohexylene skeleton.
The alicyclic polyisocyanate is preferably a compound containing a divalent group represented by the formula (B).

（式（Ｂ）中、Ｒ_２１は、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表す。ｎは０〜１０の整数を表す。ｎが２以上の整数である場合、複数のＲ_２１は、それぞれ同一であっても異なる種類の基であってもよい。）
脂環式ポリイソシアネートは、式（Ｂ−１）で表される化合物であることが好ましい。

(In formula (B), R ₂₁ represents an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. N represents an integer of 0 to 10. When n is an integer of 2 or more. The plurality of R ₂₁ may be the same or different groups.)
The alicyclic polyisocyanate is preferably a compound represented by the formula (B-1).

(In formula (B-1), R ₂₁ and n represent the same meaning as described above.)
The alicyclic polyisocyanate is preferably isophorone diisocyanate.

  The polyol is preferably a compound represented by the formula (A-1).

(In the formula (A-1), R ₃₂ represents a single bond, an alkylene group or _{-Q-R 32} having 1 to 8 carbon atoms' -, - _{R 32} '-Q- or -R _32' -Q-R ₃₂ ″ — (Wherein R ₃₂ ′ and R ₃₂ ″ each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms, and Q represents —O—, —NH—, —S—, — Represents CO-, -O-CO-, -CO-O- or -O-CO-O-.) R ₃₃ represents a hydrocarbon group having 1 to 12 carbon atoms, a heterocyclic group, or -R _33. '-CO-R ₃₃ ″-group (wherein R ₃₃ ′ and R ₃₃ ″ each independently represents a single bond, a hydrocarbon group having 1 to 11 carbon atoms or a heterocyclic group). n ₃₁ when .n ₃₁ represents an integer of 1 to 15 is an integer of 2 or more, plural _{R 32} and _{R 33} may each be the same or different.)
The polyol is preferably at least one compound selected from the group consisting of compounds represented by formula (A-2) to formula (A-4).

(In Formula (A-2), R ₂₇ and R ₂₈ each independently represents a single bond, an alkylene group having 1 to 8 carbon atoms, or —Q—R ₂₈ ′ — or —R ₂₈ ′ —Q—R ₂₈ ′. '-(Wherein R ₂₈ ' and R ₂₈ '' each independently represents a single bond or an alkylene group having 1 to 5 carbon atoms, and Q represents -O-, -NH-, -S-, -CO. -Represents -O-CO- or -CO-O-.)

（式（Ａ−３）中、Ｒ₂₉及びＲ_３０は、それぞれ独立に、単結合又は炭素数１〜８のアルキレン基を表す。Ｑは、−Ｏ−、−ＣＯ−、−Ｏ−ＣＯ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−Ｏ−を表す。ｖ₂₉は、０〜１８の整数を表す。ｖ₂₉が２以上の整数のとき、複数のＲ₂₉及びＲ_３０は、それぞれ同一であっても異なっていてもよい。）

(In formula (A-3), R ₂₉ and R ₃₀ each independently represents a single bond or an alkylene group having 1 to 8 carbon atoms. Q represents —O—, —CO—, —O—CO—. , -CO-O- or -O-CO-O-, v ₂₉ represents an integer of 0 to 18. When v ₂₉ is an integer of 2 or more, a plurality of R ₂₉ and R ₃₀ are the same. Or different.)

式（Ａ−４）中、Ｒ_３１は、それぞれ独立に、単結合又は炭素数１〜８のアルキレン基を表す。該アルキレン基に含まれる水素原子は、炭素数１〜４のアルキル基に置換されていてもよい。ｖ_３１は、０〜１８の整数を表す。

In formula (A-4), R ₃₁ each independently represents a single bond or an alkylene group having 1 to 8 carbon atoms. The hydrogen atom contained in the alkylene group may be substituted with an alkyl group having 1 to 4 carbon atoms. v ₃₁ represents an integer of 0 to 18.

  Examples of the polyol include a low molecular weight polyol and a polyol having a molecular weight of 50 or more and less than 400. For example, aliphatic, alicyclic, aromatic, and heterocyclic dihydroxy compounds, trihydroxy compounds, tetrahydroxy compounds, and the like can be given. Specifically, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, decamethylenediol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 2,5-dimethyl-2,5-hexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, cyclohexane Dimethanol, bis (β-hydroxyethoxy) benzene, p-xylenediol, dihydroxyethyltetrahydrophthalate, 2-methylpropane-1,2,3-triol, 1,2,6-hexanetriol, pentaerythritol, neopentyl Glycol, diethylene glycol, Triethylene glycol, dipropylene glycol, tripropylene glycol, glycerine, selected from trimethylol propane.

  The low molecular weight polyol is preferably a diol compound, particularly propylene glycol, 1,4-butanediol, tripropylene glycol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol and 1,6-hexane. It is preferably selected from diols and the like. The molecular weight of the low molecular weight polyol is preferably 50 or more and 200 or less, more preferably 62 or more and 200 or less. It is preferable for the molecular weight of the low molecular weight polyol to be 62 or more and 200 or less because the stretchability of the optical film of the present invention can be suppressed.

  Examples of the high molecular weight polyol include polyols having an average molecular weight of 400 or more. For example, polyester polyols, polyether polyols, polycarbonate polyols, silicone polyols, polyolefin polyols, and copolymers thereof are used.

  The high molecular weight polyol is preferably a diol compound, preferably a compound selected from polyalkylene diols having 1 to 6 carbon atoms in the alkylene group and polycarbonate diols, particularly polypropylene glycol and polyhexamethylene carbonate diol. Is preferred. The average molecular weight of the high molecular weight polyol is preferably 400 or more and 7000 or less, and more preferably 400 or more and 5000 or less. Further, it is particularly preferably 400 or more and 2000 or less. It is preferable that the average molecular weight of the high molecular weight polyol is 400 or more and 2000 or less because the optical film of the present invention is given flexibility.

Examples of the polyester polyol include dicarboxylic acids selected from succinic acid, glutaric acid, adipic acid, azelaic acid, dodecanoic acid, phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, fumaric acid and the like. And a low molecular weight polyol. As another method, lactone compounds such as β-propiocraton, pivalolactone, δ-valerolactone, methyl-δ-valerolactone, ε-caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, trimethyl-ε-caprolactone, etc. Some have reacted with a low molecular weight polyol.
Examples of the polyether polyol include polytetramethylene glycol, polyethylene glycol, polypropylene glycol, and polyoxypropylene glycol.

  Polycarbonate polyols are those obtained by transesterification from low molecular weight polyols and compounds selected from diallyl carbonate, dialkyl carbonate and ethylene carbonate, such as poly-1,6-hexamethylene carbonate, poly-2,2 ′. -Bis (4-hydroxyhexyl) propane carbonate and the like.

  The polyol is not particularly limited, and a plurality of polyols may be used in combination. From the viewpoint of flexibility and durability of the resulting film, it is preferable to combine at least one low molecular weight polyol and at least one high molecular weight polyol. In particular, a high molecular weight polyol having an average molecular weight of 400 or more and 10,000 or less and a compound containing a low molecular weight diol compound having a molecular weight of 50 or more and less than 400 unlike a high molecular weight polyol is preferable.

As the polyamine, both aromatic polyamines and aliphatic polyamines can be used. Examples of aromatic polyamines include tolylenediamine, phenylenediamine, diaminodiphenylmethane, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diamino. Examples include benzene, 1,3,5-triethyl-2,6-diaminobenzene, 3,5,3 ′, 5′-tetraethyl-4,4′-diaminodiphenylmethane, and the like. Examples of the aliphatic polyamine include ethylenediamine, propylenediamine, hexamethylenediamine, diaminocyclohexylmethane, and 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine).
Aliphatic polyamines are preferred because of less discoloration. In particular, polyamines having an alicyclic structure are preferred because optical properties tend to be good. Examples of the polyamine having an alicyclic structure include diaminocyclohexylmethane and isophoronediamine.
Examples of the (meth) acrylate having a hydroxyl group include monohydroxy mono (meth) acrylate, monohydroxy oligo (meth) acrylate, and oligohydroxy oligo (meth) acrylate. From the viewpoint of reactivity, monohydroxyalkyl mono (meth) acrylate Is preferred. Examples of the monohydroxyalkyl mono (meth) acrylate include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, and the like. Can be mentioned.
N-hydroxyethyl acrylamide is mentioned as (meth) acrylamide which has a hydroxyl group.

  Compound having a divalent group having a cyclohexylene skeleton which may be substituted in 100 mol% of polyisocyanate is 80 mol% or more, and compound represented by formula (A-2) in 100 mol% of polyol It is preferable that it is a compound which has 60 mol% or more.

  The mixing ratio during the reaction of the alicyclic polyisocyanate and the polyol is preferably 1.00 to 2.00 times the number of the isocyanate groups contained in the alicyclic polyisocyanate with respect to the number of hydroxyl groups contained in the polyol. Is 1.01-1.50 times, more preferably 1.02-1.20 times. It is preferable that the mixing ratio at the time of the reaction between the alicyclic polyisocyanate and the polyol is in the above range because the molecular weight of the resin can be adjusted from the viewpoint of the flexibility and durability of the film. The mixing ratio when the polyamine is further reacted with the polyurethane is such that the number of isocyanate groups contained in the polyurethane is 0.50 to 1.00 times the amount of amino groups contained in the polyamine, preferably 0.70 to 0. .98 times the amount, more preferably 0.80 to 0.95 times the amount. It is preferable that the mixing ratio at the time of reaction between polyurethane and polyamine is in the above range because the molecular weight of the resin can be adjusted.

  The amount of the functional group capable of reacting with an isocyanate group and the compound having an ethylenic double bond is contained in a reaction product of an alicyclic polyisocyanate and a polyol, or further in a reaction product reacted with a polyamine. The amount is preferably 1.00 to 2.00 times, preferably 1.05 to 1.50 times, more preferably 1.10 to 1.20 times the number of isocyanate groups. When the mixing ratio is in the above range, it is preferable from the viewpoint of the durability of the film.

  The polyaddition reaction or the like, which is a method for producing the compound (1), may be performed using an organic solvent or without a solvent. The organic solvent is not particularly limited as long as it does not react with an isocyanate group. For example, hydrocarbons such as toluene, xylene, chlorobenzene and mineral terpenes; ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, methyl glycol acetate, cellosolve acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, etc. And ketone solvents. Further, an aprotic polar solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and γ-butyrolactone may be used.

  In the production of the compound (1), in order to accelerate the urethanization reaction, a catalyst used in a normal urethane reaction may be used as necessary. Specifically, tertiary amines such as triethylamine, N-ethylmorpholine, triethylenediamine; organotin catalysts such as dibutyltin dilaurate, dioctyltin dilaurate and tin octylate; and organic titanium catalysts such as tetrabutyltitanate , Etc.

  Further, in the production of the compound (1), it is also preferable to use a polymerization inhibitor in order to suppress polymerization of the acrylate being synthesized. Specifically, hydroquinone polymerization inhibitors such as methoquinone, hydroquinone and t-butylhydroquinone, hindered phenol polymerization inhibitors such as 2,6-di-tert-butyl-4-methylphenol and t-butylcatechol, Common things, such as a phenothiazine and a nitroso compound, can be used. One or two or more polymerization inhibitors may be used, and the amount used is generally 10 to 50000 ppm, preferably about 50 to 1000 ppm.

  The molecular weight of the compound (1) is not particularly limited, but is preferably in the range of 1,000 to 100,000 in terms of number average molecular weight from the viewpoint of viscosity and solubility. Further, the compound (1) may be a low molecular weight resin such as a urethane oligomer or a urethane urea oligomer.

  The manufacturing method of the optical film of this invention includes the film-forming process which forms into a film the solution containing a compound (1), and the extending process which extends | stretches the obtained film | membrane further. The method for producing an optical film of the present invention may further include a photopolymerization step. The photopolymerization process may be performed between the film forming process and the stretching process, performed in parallel with the film forming process, performed in parallel with the stretching process, or performed after the stretching process. In particular, it is preferably performed between the film forming step and the stretching step. In the film forming step, for example, a solvent casting method in which a solution containing the compound (1) is cast on a smooth surface and the solvent is distilled off, and a solution containing the compound (1) is extruded into a film with a melt extruder or the like. Examples thereof include a melt extrusion method. In particular, the solvent casting method is preferable because a solution containing the compound (1) can be formed as it is.

  In the photopolymerization step, the compound (1) is cured by photopolymerization with ultraviolet light (UV). Examples of ultraviolet light generation sources include fluorescent chemical lamps, black lights, low pressure, high pressure, ultrahigh pressure mercury lamps, metal halide lamps, solar rays, electrodeless lamps, and the like. The irradiation intensity of the ultraviolet light may be constant throughout, or the physical properties after curing can be finely adjusted by changing the intensity during the curing.

Examples of the stretching step include a stretching method by a tenter method, a stretching method by roll-to-roll stretching, and the like.
Stretching may be either uniaxial stretching or biaxial stretching, and may be either longitudinal stretching or lateral stretching. In particular, from the viewpoint of productivity, biaxial stretching and transverse uniaxial stretching are preferred, and transverse uniaxial stretching is particularly preferred.

  The solution containing the compound (1) is further at least one selected from the group consisting of a photopolymerization initiator (3), a solvent (4), a polymerization inhibitor, a photosensitizer, a leveling agent, and a plasticizer as necessary. It may contain seeds.

  The solution containing the compound (1) may contain a photopolymerization initiator (3). Examples of the photopolymerization initiator (3) include benzoins, benzophenones, benzyl ketals, α-hydroxy ketones, α-amino ketones, iodonium salts, sulfonium salts, and the like. More specifically, Irgacure ( Irgacure) 907, Irgacure 184, Irgacure 651, Irgacure 250, Irgacure 369 (all manufactured by Ciba Japan Co., Ltd.), Seiko All BZ, Seiko All Z, Seiko All BEE (all manufactured by Seiko Chemical Co., Ltd.), Kaya Cure ( kayacure) BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (manufactured by Dow), Adekaoptomer SP-152 and Adekaoptomer SP-170 (all above, ADEKA Co., Ltd.) and the like. it can.

Moreover, the usage-amount of a photoinitiator (3) is 0.1 to 30 weight part with respect to 100 weight part of total amounts of the solid content of the solution containing a compound (1), for example, Preferably it is 0.8. 5 to 20 parts by weight. If it is in the said range, a monomer can be polymerized, without reducing the transmittance | permeability.
In this specification, solid content means all the components remove | excluding the solvent from the solution containing a compound (1).

  The solution containing the compound (1) may contain a polymerization inhibitor in order to control the photopolymerization of the monomer and improve the stability of the obtained optical film. Examples of the polymerization inhibitor include hydroquinones having a substituent such as hydroquinone and alkyl ether, catechols having a substituent such as alkyl ether such as butylcatechol, pyrogallols, 2,2,6,6-tetramethyl-1 -Radical scavengers such as piperidinyloxy radical, thiophenols, β-naphthylamines, β-naphthols and the like.

  The amount of the polymerization inhibitor used is, for example, 0.1 to 30 parts by weight, preferably 0.5 to 10 parts by weight based on 100 parts by weight of the total solid content of the solution containing the compound (1). Parts by weight. If it is in the said range, a monomer can be polymerized, without reducing the transmittance | permeability.

  The solution containing the compound (1) may contain a photosensitizer for increasing the sensitivity of the reaction of the photopolymerization initiator. Examples of the photosensitizer include xanthones such as xanthone and thioxanthone, anthracene having a substituent such as anthracene and alkyl ether, phenothiazine, and rubrene.

  The usage-amount of a photosensitizer is 0.1 weight part-30 weight part with respect to 100 weight part of total amount of solid content of the solution containing a compound (1), Preferably 0.5 weight part- 10 parts by weight. Within the above range, the monomer can be polymerized with high sensitivity without lowering the transmittance.

  The solution containing the compound (1) may contain a solvent (4). Examples of the organic solvent include ethers, aromatic hydrocarbons, ketones, alcohols, esters, amides and the like.

  Examples of ethers include tetrahydrofuran, tetrahydropyran, 1,4-dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono Butyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, Chill cellosolve acetate, ethyl cellosolve acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol methyl ether acetate, methoxybutyl acetate, methoxy pentyl acetate, anisole, include phenetol and methyl anisole and the like.

  Examples of aromatic hydrocarbons include benzene, toluene, xylene and mesitylene.

  Examples of ketones include acetone, 2-butanone, 2-heptanone, 3-heptanone, 4-heptanone, 4-methyl-2-pentanone, cyclopentanone, and cyclohexanone.

  Examples of alcohols include methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and glycerin.

  Examples of the esters include ethyl acetate, n-butyl acetate, isobutyl acetate, amyl formate, isoamyl acetate, isobutyl acetate, butyl propionate, isopropyl butyrate, ethyl butyrate, butyl butyrate, alkyl esters, methyl lactate, ethyl lactate, Methyl oxyacetate, ethyl oxyacetate, butyl oxyacetate, methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, methyl 3-oxypropionate, ethyl 3-oxypropionate, 3-methoxypropionate Acid methyl, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 2-oxypropionate, ethyl 2-oxypropionate, propyl 2-oxypropionate, 2-methoxy Methyl propionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, methyl 2-oxy-2-methylpropionate, 2-oxy-2-methyl Ethyl propionate, methyl 2-methoxy-2-methylpropionate, ethyl 2-ethoxy-2-methylpropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, 2-oxobutanoic acid Examples thereof include methyl, ethyl 2-oxobutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate and γ-butyrolactone.

Examples of amides include N, N-dimethylformamide and N, N-dimethylacetamide.
Examples of other solvents include N-methylpyrrolidone and dimethyl sulfoxide.
A solvent can be used individually or in combination of 2 types or more, respectively.

  The solution containing the compound (1) may contain a leveling agent. Examples of leveling agents include Torre Silicone DC3PA, SH7PA, DC11PA, SH21PA, SH28PA, 29SHPA, SH30PA, polyether-modified silicone oil SH8400 (manufactured by Torresilicone), KP321, KP322, KP323, KP324. , KP326, KP340, KP341 (manufactured by Shin-Etsu Silicone), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (manufactured by GE Toshiba Silicone), Florinato (trade name) FC430, FC431 (Manufactured by Sumitomo 3M Co., Ltd.), MegaFuck (trade name) F142D, F171, F172, F173, F177, F183 R30 (manufactured by Dainippon Ink & Chemicals, Inc.), Ftop (trade name) EF301, EF303, EF351, EF352 (manufactured by Shin-Akita Kasei Co., Ltd.), Surflon (tradename) S381, S382, SC101, SC105 (Asahi Glass Co., Ltd.), E5844 (Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100 (all trade names: manufactured by BM Chemie), Megafuck (trade name) R08, the same BL20, the same F475, the same F477 and the same F443 (manufactured by Dainippon Ink & Chemicals, Inc.).

By using a leveling agent, the obtained film (membrane) can be smoothed. Furthermore, in the production process of film formation, the fluidity of the solution containing the compound (1) can be controlled, or the crosslinking density of the film obtained by polymerizing the compound (1) can be adjusted.
The content of the leveling agent is 0.001 to 2.0 parts by weight, preferably 0.005 to 1 part by weight based on 100 parts by weight of the total solid content of the solution containing the compound (1). 5 parts by weight. If it is in the said range, a monomer can be polymerized, without reducing the transmittance | permeability.

  The solution containing the compound (1) may contain a plasticizer. As the plasticizer, at least one compound selected from the group consisting of phosphoric acid esters, carboxylic acid esters, and glycolic acid esters is used. Examples of phosphate esters include triphenyl phosphate (TPP), tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate and tributyl phosphate.

Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethyl hexyl phthalate (DEHP). Examples of citrate esters include O-acetyl triethyl citrate (OACTE), O-acetyl tributyl citrate (OACTB), acetyl triethyl citrate and acetyl tributyl citrate.
Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.

  Examples of glycolic acid esters include triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate and butyl phthalyl butyl glycolate. Also trimethylolpropane tribenzoate, pentaerythritol tetrabenzoate, ditrimethylolpropane tetraacetate, ditrimethylolpropane tetrapropionate, pentaerythritol tetraacetate, sorbitol hexaacetate, sorbitol hexapropionate, sorbitol triacetate tripropionate, inositol pentaacetate And sorbitan tetrabutyrate is also a good example.

  Among the plasticizers, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diethyl hexyl phthalate, triacetin, ethyl phthalyl ethyl glycolate, trimethylol Propane tribenzoate, pentaerythritol tetrabenzoate, ditrimethylolpropane tetraacetate, pentaerythritol tetraacetate, sorbitol hexaacetate, sorbitol hexapropionate, sorbitol triacetate tripropionate, etc. are preferred, especially triphenyl phosphate, diethyl phthalate, ethyl phthalyl Ethyl glycolate, trimethylo Le propane tribenzoate, pentaerythritol tetrabenzoate, ditrimethylolpropane tetra acetate, sorbitol hexaacetate, sorbitol hexapropionate and sorbitol triacetate tripropionate are preferred.

  One or more plasticizers may be used in combination. The addition amount of the plasticizer may be appropriately selected within a range that does not significantly impair the optical film characteristics of the present invention. For example, the plasticizer is added in an amount of 0.1 to 30 wt. %.

  Specific examples of the plasticizer include (di) pentaerythritol esters described in JP-A No. 11-124445, glycerol esters described in JP-A No. 11-246704, and diglycerol esters described in JP-A No. 2000-63560. Citrate esters described in JP-A No. 11-92574, substituted phenyl phosphate esters described in JP-A No. 11-90946, and the like.

The ratio ([Re (450)] / [Re (550)]) of the retardation [Re (450)] having a wavelength of 450 nm and the retardation [Re (550)] having a wavelength of 550 nm of the light transmitted through the optical film is a wavelength. It is defined as a dispersion coefficient α, and in order for the optical film to perform uniform polarization conversion in a wide wavelength range, it is preferable that the optical film has a wavelength dispersion characteristic that the wavelength dispersion coefficient α is less than 1.00. The optical film of the present invention thus obtained usually has a wavelength dispersion coefficient α of less than 1.00.
The retardation value Re (ν) at a wavelength νnm of light transmitted through the optical film is generally increased to the right in the visible range of 300 to 700 nm, such as satisfying the relationship of Re (450) <Re (550) <Re (650). Therefore, uniform polarization conversion can be performed in a wide wavelength range.

Since the optical film of the present invention can perform uniform polarization conversion in a wide wavelength range, it is used as a retardation plate such as a λ / 2 plate and a λ / 4 plate, a viewing angle improving film, and the like. If the optical film is a λ / 4 plate, it can be combined with a linear polarizing plate to make a circular polarizing plate in a wide wavelength range, and if it is a λ / 2 plate, it can be combined with a linear polarizing plate. A polarization rotation element having a wide wavelength range can be obtained. Therefore, it can be used in various liquid crystal display devices, cathode ray tubes (CRT), touch panels, anti-reflection filters in electroluminescence (EL) lamps, and liquid crystal projectors.
The retardation plate of the present invention is thus composed of the above optical film, and is capable of uniform polarization conversion in a wide wavelength range.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. In the examples, “%” and “parts” are by weight and parts by weight unless otherwise specified. The optical anisotropy was determined by the following method.

(Optical anisotropy)
When the polymer main chain is uniaxially oriented by stretching, it has negative birefringence when the orientation direction and the direction in which the refractive index is maximum are different (for example, orthogonal). is doing. On the other hand, when the alignment direction and the direction in which the refractive index is maximum coincide with each other or almost coincide with each other (for example, when the difference between the alignment direction and the direction in which the refractive index is maximum is within 10 degrees, etc.), Refractive. The direction in which the refractive index is maximized is determined from an automatic birefringence meter (KOBRA-WR, manufactured by Oji Scientific Instruments).

(Chromatic dispersion characteristics)
In the wavelength range of 450 nm to 750 nm, wavelength dispersion characteristics were measured using an automatic birefringence meter (KOBRA-WR, manufactured by Oji Scientific Instruments).

(Average molecular weight)
The average molecular weight was determined in terms of polystyrene using gel permeation chromatography (GPC) (manufactured by Tosoh Corporation, HLC-8200).

Apparatus: HLC-8220GPC (manufactured by Tosoh Corporation)
Guard column; TSK guard column Super H-H (trade name)
Column; TSK-gel SuperHM-H (trade name)
TSK-gel SuperHM-H (trade name)
TSK-gel SuperHM-H (trade name) (series connection)
Column temperature: 40 ° C
Solvent: THF
Flow rate: 0.6 mL / min
Injection volume: 50 μL
Detector: RI, UV
Measurement sample concentration: 0.6% by mass (solvent: THF)
Reference material for calibration; TSK STANDARD POLYSTYRENE
A-500, A-1000, A-2500, A-5000,
F-1, F-2, F-4, F-10, F-20, F-40,
F-80, F-128, F-288, F-380
(Product name, manufactured by Tosoh Corporation)
The ratio of weight average molecular weight and number average molecular weight obtained in the above measurement method was defined as molecular weight distribution (Mw / Mn).

(Synthesis Example 1)
In a reaction vessel equipped with a stirrer, thermometer and reflux condenser, 20.64 parts of polyhexamethylene carbonate diol (average molecular weight 860), 5.19 parts of 1,4-cyclohexanedimethanol, 0.11 part of dibutyltin dilaurate Then, 113.41 parts of propylene glycol monomethyl ether acetate was added, and 14.67 parts of isophorone diisocyanate was added dropwise with stirring in a nitrogen stream. After completion of the dropping, the reaction was carried out at 90 ° C. for 5 hours in a nitrogen stream, and then N-hydroxyethyl 1.58 parts of acrylamide was charged and reacted at 50 ° C. for 1 hour to obtain a urethane acrylamide solution containing urethane acrylamide having a number average molecular weight of 4.0 × 10 ⁴ .

Example 1
The urethane acrylamide solution prepared in Synthesis Example 1 was applied on a polyethylene terephthalate release film with a 700 μm gap applicator, dried at 80 ° C. for 15 minutes, and UV irradiation (high pressure mercury lamp: 650 mJ / cm ² per pass: 365 nm. ), And further stretched 3.0 times using a temperature-controlled autograph stretching machine.
Wavelength dispersion characteristics of the obtained film were measured using an automatic birefringence meter (KOBRA-WR, manufactured by Oji Scientific Instruments) in the wavelength range of 450 nm to 750 nm.
Furthermore, the phase difference was measured while heating the film on a hot stage. The evaluation results are shown in Table 1.

(Comparative Example 1)
Table 1 shows the results of evaluating Pure Ace WR S-142 (registered trademark, manufactured by Teijin Kasei) in the same manner as in Example 1.

  Compared with the comparative example, the film of the example is superior in heat resistance stability, is less likely to cause display unevenness due to phase difference unevenness due to heat, and provides good display performance.

  According to the optical film of the present invention, it is excellent in heat resistance stability and enables uniform polarization conversion in a wide wavelength range.

Claims (6)

  A compound obtained by further reacting a compound obtained by reacting a polyisocyanate compound having an alicyclic hydrocarbon skeleton and a polyol compound with a functional group capable of reacting with an isocyanate group and a compound having an ethylenic double bond An optical film containing a resin composed of structural units derived from the above.   The optical system according to claim 1, wherein the functional group capable of reacting with an isocyanate group and the compound having an ethylenic double bond are at least one compound selected from the group consisting of an acrylamide compound having a hydroxyl group and a methacrylamide compound having a hydroxyl group. the film. The optical film according to claim 1 or 2, wherein a retardation value Re (ν) at a wavelength νnm of transmitted light that passes through the optical film satisfies the following formula.
Re (450) <Re (550) <Re (650)   The phase difference plate which consists of an optical film in any one of Claims 1-3.   A compound obtained by further reacting a compound obtained by reacting a polyisocyanate compound having an alicyclic hydrocarbon skeleton and a polyol compound with a functional group capable of reacting with an isocyanate group and a compound having an ethylenic double bond A method for producing an optical film, comprising: a film forming process for forming a solution containing the composition; and a stretching process for stretching the obtained film.   In the film-forming process, a compound obtained by reacting a polyisocyanate compound having an alicyclic hydrocarbon skeleton with a polyol compound is further reacted with a functional group capable of reacting with an isocyanate group and a compound having an ethylenic double bond. The method for producing an optical film according to claim 5, which is a step of forming a film by casting a solution containing a compound obtained by casting onto a smooth surface and distilling off the solvent.