JP2011085894A - Optical film and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film having good heat resistance. <P>SOLUTION: The optical film includes: a resin containing a structural unit derived from polyurethane urea obtained by reacting polyol (A), polyisocyanate (B), polyamine (C) and a hydroxyl group-containing acrylic compound (D); and a photopolymerization initiator, and the weight-average molecular weight of the polyurethane urea is 70,000 to 110,000. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical film, a method for producing the optical film, and the like.

  A resin containing a structural unit derived from polyurethane urea obtained by reacting a polyol (A), a polyisocyanate (B), a polyamine (C), and a hydroxyl group-containing acrylic compound (D) is known.

  Development of various films using the above resins is expected.

  Under such circumstances, the present inventors have found that the above resin having a specific weight average molecular weight is suitable as a raw material for an optical film having excellent heat resistance, and have led to the present invention.

The present invention is the following inventions.
1. A polyurethane containing a resin containing a structural unit derived from polyurethane urea obtained by reacting a polyol (A), a polyisocyanate (B), a polyamine (C) and a hydroxyl group-containing acrylic compound (D), and a photopolymerization initiator, An optical film having a weight average molecular weight of urea of 70,000 to 110,000.

2. Polyurethane urea is a tie-force CS series CS-S-207 (trade name, manufactured by DIC Corporation), a tie-force CS series CS-S-208 (trade name, manufactured by DIC Corporation), or a tie-force CS series CS-. S-65 (trade name, manufactured by DIC Corporation), Tyforce CS series CS-S-070 (trade name, manufactured by DIC Corporation), or Tyforce CS series CS-S-100 (trade name, DIC ( 1). The optical film as described.

（式（Ｉ）中、Ｒ_１は、水素原子又はメチル基を表し、Ｒ_２は、炭素数６〜２０の環状炭化水素基又は炭素数４〜２０の複素環基を表し、該環状炭化水素基及び複素環基は、水酸基、オキソ基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数６〜１２のアリール基、炭素数７〜１２のアラルキル基、グリシジルオキシ基、炭素数２〜４のアシル基、炭素数１〜１２のアシルオキシ基、アミノ基、一つ若しくは二つの炭素数１〜１２のアルキル基で置換されたアミノ基又はハロゲン原子で置換されていてもよく、前記アルキル基、アルコキシ基、アリール基、アラルキル基、アシル基及びアシルオキシ基は、水酸基、アミノ基、炭素数１〜６のアルコキシ基、炭素数１〜６のアシルオキシ基又は炭素数１〜６のアシル基で置換されていてもよい。） 3. 1. The resin contains a structural unit derived from the monomer represented by the formula (I) Or 2. The optical film as described.

(In Formula (I), _{R 1} represents a hydrogen atom or a methyl group, _{R 2} represents a heterocyclic group of a cyclic hydrocarbon group or 4 to 20 carbon atoms having from 6 to 20 carbon atoms, cyclic hydrocarbons Group and heterocyclic group include a hydroxyl group, an oxo group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and glycidyloxy A group, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 1 to 12 carbon atoms, an amino group, an amino group substituted with one or two alkyl groups having 1 to 12 carbon atoms, or a halogen atom. The alkyl group, alkoxy group, aryl group, aralkyl group, acyl group and acyloxy group may be a hydroxyl group, an amino group, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, or 1 to 1 carbon atoms. 6 acyl In may be substituted.)

（式（ＩＩ）中、Ｒ_７は水素原子又はメチル基を表す。Ｒ_８は、水素原子、メチル基、炭素数２〜１８のアルキル基、炭素数２〜６のアルキルアミノ基、又は炭素数６〜２０の環状炭化水素基を表す。該アルキル基、及び該アルキルアミノ基に含まれる水素原子は、水酸基、オキソ基又はカルボキシル基で置換されていてもよく、該アルキル基に含まれる−ＣＨ_２−は、−Ｏ−、−Ｓ−又は−ＮＨ−で置き換わっていてもよい。該環状炭化水素基に含まれる水素原子は、水酸基、オキソ基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、炭素数６〜１２のアリール基、炭素数７〜１２のアラルキル基、グリシジルオキシ基、炭素数２〜４のアシル基又はハロゲン原子で置換されていてもよく、該環状炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−Ｓ−又は−ＮＨ−で置き換わっていてもよい。該アルキル基、該アルコキシ基、該アリール基及び該アラルキル基に含まれる水素原子は、水酸基又はハロゲン原子で置換されていてもよい。） 4). 1. The resin contains a structural unit derived from the monomer represented by the formula (II) ~ 3. The optical film in any one of.

(In formula (II), R ₇ represents a hydrogen atom or a methyl group. R ₈ represents a hydrogen atom, a methyl group, an alkyl group having 2 to 18 carbon atoms, an alkylamino group having 2 to 6 carbon atoms, or a carbon number. Represents a cyclic hydrocarbon group of 6 to 20. The hydrogen atom contained in the alkyl group and the alkylamino group may be substituted with a hydroxyl group, an oxo group or a carboxyl group, and —CH contained in the alkyl group _2- may be replaced by -O-, -S- or -NH- The hydrogen atom contained in the cyclic hydrocarbon group is a hydroxyl group, an oxo group, an alkyl group having 1 to 12 carbon atoms, or a carbon number. The cyclic group may be substituted with an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an acyl group having 2 to 4 carbon atoms, or a halogen atom. Included in hydrocarbon groups —CH ₂ — may be replaced by —O—, —S— or —NH— The hydrogen atom contained in the alkyl group, alkoxy group, aryl group and aralkyl group is a hydroxyl group or a halogen atom. May be substituted with.)

5). 1. The retardation value Re (ν) at a wavelength νnm of transmitted light that passes through the optical film satisfies the following formula. ~ 4. The optical film in any one of.
Re (450) <Re (550) <Re (650)

6). 1. It has optical biaxiality ~ 5. The optical film in any one of.

7. 1. ~ 6. A retardation film comprising the optical film according to any one of the above.

8). 1. ~ 6. A method for producing an optical film according to any one of the above, wherein the polyurethane is obtained by reacting a polyol (A), a polyisocyanate (B), a polyamine (C), and a hydroxyl group-containing acrylic compound (D). A method for producing an optical film, comprising a resin containing a structural unit derived from urea and forming an optical film by forming a film of a polyurethane urea having a weight average molecular weight of 70,000 to 110,000 and further stretching the composition.

9. A resin containing a structural unit derived from polyurethane urea obtained by reacting a polyol (A), a polyisocyanate (B), a polyamine (C), and a hydroxyl group-containing acrylic compound (D), and the weight average molecular weight of the polyurethane urea is 7. A solution containing a composition of 70,000 to 110,000 is cast on a smooth surface and the solvent is distilled off to form a film, which is further stretched to obtain an optical film. The manufacturing method of the optical film of description.

10. Obtained by reacting polyol (A), polyisocyanate (B), polyamine (C), and hydroxyl group-containing acrylic compound (D) as a raw material for an optical film having a heat resistance having a retardation variation Δ of 5% or less. Use of polyurethane urea having a weight average molecular weight of 70,000 to 110,000.

11. Obtained by reacting polyol (A), polyisocyanate (B), polyamine (C), and hydroxyl group-containing acrylic compound (D) as a raw material for an optical film having a resistance to moisture and heat having a retardation variation rate of 5% or less. Use of polyurethane urea having a weight average molecular weight of 70,000 to 110,000.

  The optical film of the present invention has good heat resistance.

  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.

  The resin contained in the optical film of the present invention includes a structural unit derived from polyurethane urea obtained by reacting a polyol (A), a polyisocyanate (B), a polyamine (C), and a hydroxyl group-containing acrylic compound (D), The weight average molecular weight is 70,000 to 110,000.

  The polyol (A) is preferably one having a number average molecular weight of 1,000 to 5,000 by GPC in terms of polystyrene. For example, one or more selected from polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyester polyol, etc. Can be mentioned.

  Examples of the polyisocyanate (B) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, partially carbodiimidized diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, tolylene diisocyanate, One kind of aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates such as naphthalene diisocyanate, phenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate or the like A mixture is mentioned.

  Examples of the polyamine (C) include ethylenediamine, propylenediamine, hexamethylenediamine, trimethylhexamethylenediamine, isophoronediamine, diaminocyclohexane, methyldiaminocyclohexane, biperazine and the like.

  Examples of the hydroxyl group-containing acrylic compound (D) include hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxybutyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, and the like.

The polyurethane urea resin may be produced by reacting the polyol (A), polyisocyanate (B), polyamine (C), and hydroxyl group-containing acrylic compound (D), and the reaction sequence is not particularly limited. Absent.
As the reaction sequence, for example, polyisocyanate (B) and polyamine (C) are reacted in advance to obtain a polyurea prepolymer of terminal isocyanate, and then this is reacted with polyol (A) and hydroxyl group-containing acrylic compound (D). And a method of reacting the polyol (A) with the polyisocyanate (B) to obtain a urethane prepolymer having a terminal isocyanate group, and then reacting this with the polyamine (C) and the hydroxyl group-containing acrylic compound (D). Can be mentioned. The reaction of the polyol (A), the polyisocyanate (B), the polyamine (C), and the hydroxyl group-containing acrylic compound (D) can be carried out in the absence of a solvent, in an organic solvent, or in water, but is usually organic. The reaction is carried out in a solvent at 20 to 120 ° C., preferably 30 to 100 ° C. for 30 minutes to 24 hours.
Although the equivalent ratio of the active hydrogen atom-containing group of the polyol (A), polyamine (C), and hydroxyl group-containing acrylic compound (D) to the isocyanate group of the polyisocyanate (B) is not particularly limited, it is usually 0.8. 5: 1 to 1: 0.5. For example, as a method for producing a polyurethane urea resin, a polyol (A) and a polyisocyanate (B) are reacted in advance to obtain a urethane prepolymer having a terminal isocyanate group, and then, this, a polyamine (C), a hydroxyl group-containing acrylic compound (D), and When the method of reacting is used, a urethane prepolymer having a terminal isocyanate group is usually used at a ratio in which the equivalent ratio of the hydroxyl group of the polyol (A) to the isocyanate group of the polyisocyanate (B) is 1: 1.1 to 1: 3. A polymer is obtained, and then reacted in such a ratio that the equivalent ratio of the active hydrogen atoms of the isocyanate group of the urethane prepolymer to the polyamine (C) and the hydroxyl group-containing acrylic compound (D) is 1: 0.6 to 1: 1.2. .
In the production method of the polyurethane urea resin, the reaction can be promoted by using a tertiary amine catalyst or / and an organometallic catalyst, if necessary.
Examples of the organic solvent include ethyl acetate, butyl acetate, cellosolve, cellosolve acetate, acetone, methyl ethyl ketone, cyclohexanone, toluene, xylene, dimethylformamide, dimethylacetamide, and isopropanol.

  The weight average molecular weight of the polyurethane urea is 70,000 to 110,000. Within the above range, good productivity and workability can be ensured, and an optical film with a desired birefringence and high heat resistance can be obtained with a thinner film.

A method for controlling the molecular weight of polyurethane urea will be described. The molecular weight of the polyurethane urea is appropriately controlled by the equivalent ratio of the active hydrogen atom-containing group of the polyol (A), polyamine (C), and hydroxyl group-containing acrylic compound (D) and the equivalent ratio of the isocyanate group to the polyisocyanate (B). That's fine. Specifically, for example, the polyurethane urea has a higher molecular weight as the ratio of 0.5: 1 to 1: 0.5 described above is closer to 1: 1, and the polyurethane urea has a lower molecular weight as the distance from 1: 1 is increased. .
The molecular weight of polyurethane urea can be easily confirmed by instrumental analysis using the following molecular weight measurement conditions.
<Molecular weight measurement conditions>
・ Device name: Tosoh Corporation HLC-8220 GPC
-Weight average molecular weight in terms of polystyrene measured by gel permeation chromatography using a standard polystyrene calibration curve with known molecular weight-Eluent tetrahydrofuran-Flow rate 1 mL / min-Detection Refractometer (RI)

  Polyurethane urea is urethane urea resin solvent solution Tyforce CS series unmodified type part number: CS-S-207 (trade name, manufactured by DIC Corporation), urethane urea resin solvent solution Tyforce CS series unmodified type part number: CS- S-208 (trade name, manufactured by DIC Corporation) or urethane urea resin solvent solution Tyforce CS series acryloyl group introduction type Part No .: CS-S-65 (trade name, manufactured by DIC Corporation), urethane urea resin solvent solution Tyforce CS series acryloyl group introduction type Part number: CS-S-070 (trade name, manufactured by DIC Corporation) or urethane urea resin solvent solution Tyforce CS series acryloyl group introduction type Part number: CS-S-100 (trade name) DIC Corporation) . These products developed and marketed by DIC are characterized by excellent transparency, excellent UV crosslinkability and excellent durability (heat resistance, moist heat resistance, alkali resistance, etc.).

  The content of the structural unit derived from polyurethane urea is, for example, 10 to 100% by weight, preferably 30 to 98% by weight, when the total amount of all the structural units contained in the optical film of the present invention is 100% by weight, Particularly preferred is 50 to 95% by weight. Within the above range, it is preferable because the optical film can perform more uniform polarization conversion in a wide wavelength range.

The resin is at least one monomer selected from the group consisting of monomers represented by the formulas (I) and (II) (hereinafter sometimes referred to as “monomer (I) and monomer (II)”) (hereinafter “monomer”). It is preferable to have a structural unit derived from (sometimes referred to as “(1)”).
Having a structural unit derived from monomer (I) is preferable because the resulting optical film can perform more uniform polarization conversion in a wide wavelength range, and it has a structural unit derived from monomer (II). Then, since the photoelastic coefficient of the obtained optical film is small, the occurrence of birefringence due to stress is extremely small, and light leakage caused by phase difference change due to contraction of the polarizing plate after bonding is suppressed, and optical It is preferable because it becomes possible to obtain a film without unevenness. That is, it is more preferable to have both a structural unit derived from the monomer (I) and a structural unit derived from the monomer (II).

(In Formula (I), _{R 1} represents a hydrogen atom or a methyl group, _{R 2} represents a heterocyclic group of a cyclic hydrocarbon group or 4 to 20 carbon atoms having from 6 to 20 carbon atoms, cyclic hydrocarbons Group and heterocyclic group include a hydroxyl group, an oxo group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and glycidyloxy A group, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 1 to 12 carbon atoms, an amino group, an amino group substituted with one or two alkyl groups having 1 to 12 carbon atoms, or a halogen atom. The alkyl group, alkoxy group, aryl group, aralkyl group, acyl group and acyloxy group may be a hydroxyl group, an amino group, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, or 1 to 1 carbon atoms. 6 acyl In may be substituted.)
An oxo group represents O = of a carbonyl group.

In the monomer (I), R ₁ is preferably a hydrogen atom.
In the monomer (I), the cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, preferably an aromatic hydrocarbon group. It may be a monocyclic hydrocarbon group or a condensed cyclic hydrocarbon group. Specific examples of the alicyclic hydrocarbon group include a cyclohexyl group. Specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and an anthracenyl group. The heterocyclic group may be a heterocyclic group containing a hetero atom such as a nitrogen atom or an oxygen atom as a constituent atom of the ring. It may be a monocyclic heterocyclic group or a condensed cyclic heterocyclic group. Specific examples include pyrrolyl group, furanyl group, thiophene group, pyrazinyl group, pyrazolyl group, imidazolyl group, pyridinyl group, piperidinyl group, piperazinyl group, tetrahydrofuranyl group, indole group, thiazolyl group, carbazolyl group and the like. R ₂ is preferably an aromatic hydrocarbon group or a heterocyclic group.

  The cyclic hydrocarbon group and the heterocyclic group include a hydroxyl group, an oxo group, such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, or an octyl group, such as an alkyl group having 1 to 12 carbon atoms, such as a methoxy group or an ethoxy group. An alkoxy group having 1 to 12 carbon atoms such as an aryl group having 6 to 12 carbon atoms such as a phenyl group or a naphthyl group, an aralkyl group having 7 to 12 carbon atoms such as a benzyl group, a glycidyloxy group such as an acetyl group An acyl group having 2 to 4 carbon atoms, for example, an acyloxy group having 1 to 12 carbon atoms such as an acetyloxy group, an amino group such as an ethylamino group or a dimethylamino group, or one or two alkyl groups having 1 to 12 carbon atoms And at least one selected from the group consisting of a halogen atom such as a fluorine atom, a chlorine atom or a bromine atom. In may be substituted.

The cyclic hydrocarbon group and the heterocyclic group may be a group in which at least one selected from the group consisting of a cyclic hydrocarbon group and a heterocyclic group is bonded to the cyclic hydrocarbon group or the heterocyclic group via a linking group. . Examples of the linking group include a methylene group, an ethylidene group (that is, ethane-1,1-diyl group), a propylidene group (that is, propane-1,1-diyl group), and an isopropylidene group (that is, propane-2,2-diyl group). ), A cyclohexylidene group (that is, cyclohexanediyl group), an ethylene group or a propylene group (that is, propane-1,3-diyl group) or the like, a hydrocarbon group having about 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a carbonyl group or -CO ₂ - and the like. A group selected from a plurality of cyclic hydrocarbon groups and heterocyclic groups may be bonded by a single bond.

  Specifically, a biphenyl group in which a plurality of aromatic hydrocarbon groups are bonded by a single bond, or a formula below in which a plurality of aromatic hydrocarbon groups are bonded by an isopropylidene group (that is, propane-2,2-diyl group). And the group represented.

  Examples of the monomer (I) include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, o-ethylstyrene, p-ethylstyrene, trimethylstyrene, propylstyrene, tert- Alkyl styrene such as butyl styrene, cyclohexyl styrene, dodecyl styrene, such as hydroxy styrene, t-butoxy styrene, vinyl benzoic acid, vinyl benzyl acetate, o-chloro styrene, p-chloro styrene, amino styrene, etc. Substituted styrene to which a group selected from an alkoxy group, a carboxyl group, an acyloxy group, a halogen, an amino group and the like are bonded, such as 4-vinylbiphenyl, 2-ethyl-4benzylstyrene, 4- (phenylbutyl) styrene and 4 Vinyl biphenyl compounds such as hydroxy-4'-vinyl biphenyl, compounds and the like having a condensed ring and a vinyl group such as vinyl naphthalene and vinyl anthracene.

  Examples of the monomer (I) having an aromatic heterocyclic group include N-vinylpyrrolidone, N-vinylimidazole, N-vinylcarbazole, N-vinylpyridine, N-vinylphthalimide and N-vinylindole.

  When the monomer (I) is at least one monomer selected from the group consisting of styrene, N-vinylcarbazole, vinylnaphthalene and vinylanthracene, the optical film performs more uniform polarization conversion in a wide wavelength range. It is preferable because it becomes possible, and styrene or N-vinylcarbazole is particularly preferable. A plurality of different monomers may be used in combination as the monomer (I).

  The content of the structural unit derived from the monomer (I) may not be included when the total amount of all the structural units included in the optical film of the present invention is 100% by weight. %, Preferably 2 to 70% by weight, particularly preferably 5 to 50% by weight.

(In formula (II), R ₇ represents a hydrogen atom or a methyl group. R ₈ represents a hydrogen atom, a methyl group, an alkyl group having 2 to 18 carbon atoms, an alkylamino group having 2 to 6 carbon atoms, or a carbon number. Represents a cyclic hydrocarbon group of 6 to 20. The hydrogen atom contained in the alkyl group and the alkylamino group may be substituted with a hydroxyl group, an oxo group or a carboxyl group, and —CH contained in the alkyl group _2- may be replaced by -O-, -S- or -NH- The hydrogen atom contained in the cyclic hydrocarbon group is a hydroxyl group, an oxo group, an alkyl group having 1 to 12 carbon atoms, or a carbon number. The cyclic group may be substituted with an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an acyl group having 2 to 4 carbon atoms, or a halogen atom. Included in hydrocarbon groups —CH ₂ — may be replaced by —O—, —S— or —NH— The hydrogen atom contained in the alkyl group, alkoxy group, aryl group and aralkyl group is a hydroxyl group or a halogen atom. May be substituted with.)

In the monomer (II), R ₇ is preferably a hydrogen atom.
In the monomer (II), examples of the cyclic hydrocarbon group having 6 to 20 carbon atoms include aromatic hydrocarbon groups such as a phenyl group, a naphthyl group, and an anthranyl group, such as a cyclopentyl group, a cyclohexyl group, an isobornyl group, and a tricyclodecanyl group. A cycloalkyl group such as a group, an adamantyl group, and a norbornane lactone group.

The cyclic hydrocarbon group includes an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group and an octyl group, for example, an alkoxy group having 1 to 12 carbon atoms such as a methoxy group and an ethoxy group. A group, for example, a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom, for example, an acyl group having 2 to 4 carbon atoms such as an acetyl group, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, At least one group selected from the group consisting of a hydroxyl group, a glycidyloxy group and a carboxyl group may be bonded.
—CH ₂ — contained in the cyclic hydrocarbon group may be replaced by —O—, —S— or —NH—.

Specific examples of the monomer (II) include (meth) acrylic acid, methyl (meth) acrylate, phenyl (meth) acrylate, naphthyl (meth) acrylate, anthracenyl (meth) acrylate, cyclohexyl (meth) acrylate, and 2-tetrahydropyrani. (Meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, adamantyl (meth) acrylate, hydroxyadamantyl (meth) acrylate, methyladamantyl (meth) acrylate, ethyladamantyl (meth) acrylate, norbornane lactone (meth) acrylate, 2- (5-oxo-4-oxa-tricyclo [4,2,1,0 ^3,7] nonane-2-yloxy) -2-oxoethyl (meth) acrylate, 1- (main T) Acryloyl-4-methoxynaphthalene, 2-hydroxyethyl (meth) acrylate, 2- (dimethylamino) ethyl (meth) acrylate, polyethylene glycol monomethyl ether (meth) acrylate, polypropylene glycol monomethyl ether (meth) acrylate and glycerin mono (Meth) acrylate etc. are mentioned.

As the monomer (II), methyl (meth) acrylate, phenyl (meth) acrylate, naphthyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-tetrahydropyranyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodeca Nyl (meth) acrylate, adamantyl (meth) acrylate, hydroxyadamantyl (meth) acrylate, methyladamantyl (meth) acrylate, ethyladamantyl (meth) acrylate, norbornane lactone (meth) acrylate, 2- (5-oxo-4-oxa tricyclo [4,2,1,0 ^3,7] nonane-2-yloxy) -2-oxoethyl (meth) acrylate, 1- (meth) acryloyl-4-methoxynaphthalene, 2-hydroxyethyl ( Since at least one monomer selected from the group consisting of (meth) acrylate and glycerin mono (meth) acrylate, the photoelastic coefficient of the optical film is small, so the expression of birefringence due to stress is extremely small, and polarization after bonding It is preferable because it is possible to obtain a film having no optical unevenness by suppressing light leakage caused by a change in retardation value due to contraction of the plate, etc., and isobornyl (meth) acrylate, tricyclodecanyl (meth) Group consisting of acrylate, adamantyl (meth) acrylate, hydroxyadamantyl (meth) acrylate, methyladamantyl (meth) acrylate, ethyladamantyl (meth) acrylate, norbornane lactone, 2-hydroxyethyl (meth) acrylate and glycerin mono (meth) acrylate Or And particularly preferably at least one monomer selected. A plurality of different monomers may be used in combination as the monomer (II).

  The content of the structural unit derived from the monomer (II) may not be included when the total amount of all the structural units included in the optical film of the present invention is 100% by weight. %, Preferably 2 to 70% by weight, particularly preferably 5 to 50% by weight.

  The content of the structural unit derived from the monomer (1) is, for example, 1 to 90% by weight, preferably 2 to 70% by weight when the total amount of all the structural units contained in the optical film of the present invention is 100% by weight. %, Particularly preferably 5 to 50% by weight.

The monomer (1) can be used as it is, or it can be polymerized and used as the polymer (1). A part of the polymer (1) can be used and a part of the monomer (1) can be used as it is. As a polymerization method of the polymer (1), a known radical polymerization method may be mentioned.
Examples of the radical polymerization method include polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization, but are not particularly limited. From the viewpoints of molecular weight adjustment, ease, film formability, etc., solution polymerization is preferred.

A commercially available polymer may be used as the polymer (1). Polyvinylcarbazole is sold by, for example, Sigma-Aldrich Japan, and polystyrene is sold by, for example, Wako Pure Chemical Industries, Ltd. and Kanto Chemical Co., Ltd.
As the monomer constituting the polymer (1), it is particularly preferable to use a combination of the monomer (I) and the monomer (II).

  The content of the structural unit derived from the polymer (1) may not be included when the total amount of all the structural units included in the optical film of the present invention is 100% by weight, but it is 10 to 70% by weight. %, Preferably 30 to 60% by weight, particularly preferably 40 to 55% by weight.

  The optical film of the present invention can be obtained by forming a composition containing a polyurethane urea into a film and further stretching. The step of forming a film and further stretching may include a photopolymerization step. The photopolymerization may be performed after film formation and before stretching, or may be performed while film formation and stretching, or may be performed after film formation and further stretching. In particular, it is preferable to obtain a film after it is formed and photopolymerized and then stretched.

  In the photopolymerization step, the composition containing polyurethane urea is photopolymerized with ultraviolet light (UV) and cured. 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.

  The composition containing polyurethane urea further contains a photopolymerization initiator.

  Examples of the photopolymerization initiator include benzoins, benzophenones, benzyl ketals, α-hydroxyketones, α-aminoketones, alkylphenones, thioxanthones, acylphosphine oxides, oxime ester derivatives, iodonium salts and sulfoniums. More specifically, examples include IRGACURE 907, Irgacure 184, Irgacure 651, Irgacure 250, Irgacure 369, Irgacure OXE01, Irgacure OXE02 (all are manufactured by Ciba Japan Co., Ltd.), and Seiko All BZ. , Sequol Z, Sequol BEE (all above, manufactured by Seiko Chemical Co., Ltd.), KAYACURE BP100, Kayacure DETX-S, Kayacure CTX, Kayacure -BMS (all manufactured by Nippon Kayaku Co., Ltd.), UVI-6992 (manufactured by Dow), Adekaoptomer SP-150, Adekaoptomer SP-152, Adekaoptomer SP-172, Adekaoptomer N- 1414, Adeka optomer N-1606, Adeka optomer N-1717, Adeka optomer N-1919 (all of which are manufactured by ADEKA Corporation) and the like. As the photopolymerization initiator, a radical photopolymerization initiator is preferable.

  Moreover, the usage-amount of a photoinitiator is 0.1 weight part-30 weight part with respect to 100 weight part of polyurethane ureas, for example, Preferably it is 0.5 weight part-20 weight part.

  The composition containing polyurethane urea may further contain at least one selected from the group consisting of a polymerization inhibitor, a photosensitizer, a solvent, a leveling agent, and a plasticizer as necessary.

  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 with respect to 100 parts by weight of polyurethane urea.

  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 polyurethane ureas, Preferably it is 0.5 weight part-10 weight part.

  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 composition of the present invention may contain a leveling agent. Examples of the leveling agent include organic modified silicone oils, polyacrylates, perfluoroalkyls and the like.
Specifically, for example, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all are manufactured by Toray Dow Corning Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all manufactured by Momentive Performance Materials Japan GK), Fluorinert (Product Name) FC-72, FC-40, FC-43, FC-3283 (all above, all manufactured by Sumitomo 3M Limited), Mega Fuck (Product Name) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-477, F-479, F-479 F-482, F-484 (above, both are manufactured by DIC Corporation), F-top (trade name) EF301, EF303, EF351, EF352 (all are manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd.), Surflon (trade names) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, SA-100 (all above, AGC Seimi Chemical Co., Ltd.) )), Trade names E1830, E5844 (produced by Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100 (both trade names: manufactured by BM Chemie), and the like.
Two or more of these leveling agents may be used in combination.

  The content of the leveling agent is 0.001 to 2.0 parts by weight, preferably 0.005 to 1.5 parts by weight, based on 100 parts by weight of the polyurethane urea.

  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, it is about 0.1 to 30% by weight with respect to the total solid content of the composition containing polyurethane urea. is there. The total solid content is an amount obtained by subtracting the solvent from the composition containing polyurethane urea.

  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 optical film of the present invention is usually produced by forming a film containing a composition containing polyurethaneurea and further stretching the obtained film-like product. Alternatively, the optical film of the present invention is produced by forming a film (formation) of a composition containing polyurethane urea, photopolymerizing, and further stretching the obtained film-like product. Examples of a method for forming a film of the composition include, for example, a solvent casting method in which a solution containing the composition is cast on a smooth surface to distill off the solvent, and the composition is extruded into a film with a melt extruder or the like. And melt extrusion method. In particular, the solvent casting method is preferable because a solution containing the composition can be directly formed into a film.

Examples of the stretching method include a stretching method by a tenter method and a stretching method by roll-to-roll stretching.
Stretching may be either uniaxial stretching or biaxial stretching, and may be either longitudinal stretching or lateral stretching.
Examples of the uniaxial stretching method include a uniaxial stretching method in the longitudinal direction by stretching between rolls and a uniaxial stretching method in the lateral direction using a tenter machine. The biaxial stretching method grips the side edge of the film. The rail width of the tenter clip is opened, and at the same time, the two ends are stretched in the longitudinal direction by stretching in the longitudinal direction by stretching the guide rail at the same time as stretching in the longitudinal direction and by stretching between the rolls. Examples include a sequential biaxial stretching method in which the film is held by a tenter clip and stretched in the transverse direction using a tenter machine.
In particular, from the viewpoint of productivity, transverse uniaxial stretching and biaxial stretching are preferred, and transverse uniaxial stretching is particularly preferred.
An optical film having optical biaxiality can be obtained by lateral uniaxial stretching or biaxial stretching. Here, the optical biaxial each n _x orthogonal two directions of refractive index in the film _{plane, (and} provided that _{n x> n y) n y} , and the refractive index in the thickness direction is n _z in is to be _{n x ≠ n y ≠ n z} , contrary to _{n x, n y,} if any two of the _{n z} is equal (e.g., _{n x> n y = n z} , etc.) is optically Uniaxial.
An optical film having optical biaxiality can perform uniform polarization conversion in the thickness direction of the film.

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.

The optical film of the present invention has a sufficiently small photoelastic coefficient, so that the occurrence of birefringence due to stress is extremely small, and suppresses light leakage caused by a retardation value change due to contraction of a polarizing plate after pasting. Thus, uniform display without optical unevenness is possible. In general, the photoelastic coefficient of the optical film is preferably 30 × 10 ⁻¹² (/ Pa) or less, more preferably 20 × 10 ⁻¹² (/ Pa) or less, and most preferably 15 × 10 ⁻¹² (/ Pa) or less. It is.

  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.

(Weight average molecular weight)
・ Device name: Tosoh Corporation HLC-8220 GPC
-Weight average molecular weight in terms of polystyrene measured by gel permeation chromatography using a standard polystyrene calibration curve with known molecular weight-Eluent tetrahydrofuran-Flow rate 1 mL / min-Detection Refractometer (RI)

(Optical anisotropy)
When the polymer main chain is oriented by stretching, it has negative birefringence when it has optical anisotropy in which the orientation direction and the direction in which the refractive index is maximized are different (for example, orthogonal, etc.) ing.
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).

(Photoelastic coefficient)
A film tensioning device is placed in the optical path of an automatic birefringence meter (KOBRA-WR, manufactured by Oji Scientific Instruments), and a test piece having a length of 60 mm and a width of 15 mm is cut out from the applied unstretched film. Then, the birefringence was measured while applying a tensile stress to the test piece at room temperature. With respect to the measured values, 3-6 points were plotted with the extension stress as the X axis and the birefringence as the Y axis, the slope of the straight line was obtained by linear approximation, and the photoelastic coefficient was calculated from the absolute value of the slope. For example, when the slope of the approximate straight line is 20 × 10 ⁻¹² , the photoelastic coefficient is 20 × 10 ⁻¹² (/ Pa), and is described as 20 in the table. The smaller the absolute value of the slope, the smaller the photoelastic coefficient, which is preferable.

(Heat resistance test)
The obtained optical film was bonded to a glass substrate, and the retardation value (Re ¹ ) at a wavelength of 550 nm of the optical film was measured. The optical film was put into a Hitachi thermostat (trade name: EC-15MTP, manufactured by Hitachi Air Conditioning System Co., Ltd.) (condition: dry bulb temperature 85 ° C. without humidity control), and the phase difference value at a wavelength of 550 nm after 500 hours (Re ² ) was measured. The phase difference fluctuation rate Δ (%) was calculated from the equation (A).
Δ = 100 × (Re ² −Re ¹ ) / Re ¹ (A)
○: Phase difference fluctuation rate Δ is 5% or less. Good heat resistance ×: Phase difference variation Δ exceeds 5%. Heat resistance is poor.

Hereinafter, polyurethane urea represents the following products.
Polyurethane urea 1; Product name: Urethane urea resin solvent solution Tyforth CS series Unmodified type, product number: CS-S-207, DIC Corporation (Resin 2 Technology Division Specialty Development Group, Takaishi City, Osaka Prefecture 592-0001) Made by Takasago 1-3), weight average molecular weight 70,000, non-volatile content 25%, viscosity 40,000, acryloyl group equivalent weight (solid content conversion) 28,000
Polyurethane urea 2; Product name: Urethane urea resin solvent solution Tyforth CS series Unmodified type Product number: CS-S-208, DIC Corporation (Resin 2nd Technology Division Specialty Development Group, Takasago, Takaishi, Osaka Prefecture 592-0001 1-3) manufactured, weight average molecular weight 110,000, non-volatile content 20%, viscosity 60,000, acryloyl group equivalent weight (solid content conversion) 28,000
Polyurethane urea 3; Product name: Urethane urea resin solvent solution Tyforce CS series Introducing acryloyl group Part number: CS-S-65, DIC Corporation (Resin 2 Technology Division Specialty Development Group, Takaishi City, Osaka Prefecture 592-0001 Made by Takasago 1-3), weight average molecular weight 70,000, non-volatile content 25%, viscosity 60,000, acryloyl group equivalent weight (solid content conversion) 28,000
Polyurethane Urea 4: Product Name: Urethane Urea Resin Solution Solution Tyforce CS Series Acryloyl Group Introduced Type Part Number: CS-S-070, DIC Corporation (Resin 2 Technology Division Specialty Development Group, Takaishi, Osaka Prefecture 592-0001 Made by Takasago 1-3), weight average molecular weight 100,000, non-volatile content 25%, viscosity 35,000, acryloyl group equivalent weight (solid content conversion) 28,000
Polyurethane urea 5: Product name: Urethane urea resin solvent solution Tyforth CS series Introducing acryloyl group Part number: CS-S-100, DIC Corporation (Specialty Development Group, Resin 2nd Technology Division, Takaishi, Osaka Prefecture 592-0001) Made by Takasago 1-3), weight average molecular weight 70,000, non-volatile content 25%, viscosity 50,000, acryloyl group equivalent weight (solid content conversion) 28,000

<Measurement method>
(Non-volatile content)
Residual rate after drying at 107 ° C. for 1 hour. The unit is% by weight.
(viscosity)
Measured with a rotational viscometer at 25 ° C. The unit is mPa · s.
(Weight average molecular weight)
Measured by gel permeation chromatography.
(Acryloyl group equivalent weight)
Calculated from the amount of acryloyl group introduced.

Example 1
80 parts of polyurethane urea 1 (20 parts as non-volatile content), photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, Irgacure 184, manufactured by Ciba Japan Co., Ltd.), surfactant (polyether-modified silicone oil) SH8400) 0.01 parts and N, N-dimethylformamide 20 parts were mixed, and then applied onto a polyethylene terephthalate release film with a 400 μm gap applicator, dried in an oven, and then irradiated with UV (high pressure mercury). Lamp: 600 mJ / cm ² : 365 nm) and further stretched 3.0 times using a temperature-controlled autograph stretching machine to prepare an optical film. Table 1 shows the optical characteristics of the optical film.

(Example 2)
An optical film was prepared in the same manner as in Example 1 except that 80 parts of polyurethane urea 1 (20 parts as non-volatile content) was changed to 100 parts of polyurethane urea 2 (20 parts as non-volatile content). Table 1 shows the optical characteristics of the optical film.

(Example 3)
An optical film was prepared in the same manner as in Example 1 except that 80 parts of polyurethane urea 1 (20 parts as a nonvolatile content) was changed to 80 parts of polyurethane urea 3 (20 parts as a nonvolatile content). Table 1 shows the optical characteristics of the optical film.

Example 4
80 parts of polyurethane urea 1 (20 parts as non-volatile content), 7.5 parts of N-vinylcarbazole [monomer (I)], photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, Irgacure 184, manufactured by Ciba Japan Co., Ltd.) ) 0.4 parts, 0.01 parts of surfactant (polyether-modified silicone oil SH8400) and 20 parts of N, N-dimethylformamide were mixed, and then an applicator with a gap of 750 μm on a release film made of polyethylene terephthalate. After being dried in an oven, it was irradiated with UV (high pressure mercury lamp: 600 mJ / cm ² : 365 nm), and further stretched 3.0 times using a temperature-controlled autograph stretching machine to prepare an optical film. Table 2 shows the optical characteristics of the optical film.

(Example 5)
80 parts of polyurethane urea 1 (20 parts as non-volatile content) was changed to 100 parts of polyurethane urea 2 (20 parts as non-volatile content), and 7.5 parts of N-vinylcarbazole [monomer (I)] was changed to 7.0 parts. An optical film was prepared in the same manner as in Example 3 except that the change was made. Table 2 shows the optical characteristics of the optical film.

(Example 6)
80 parts of polyurethane urea 1 (20 parts as non-volatile content) was changed to 80 parts of polyurethane urea 3 (20 parts as non-volatile content), and 7.5 parts of N-vinylcarbazole [monomer (I)] was changed to 6.5 parts. An optical film was prepared in the same manner as in Example 3 except that the change was made. Table 2 shows the optical characteristics of the optical film.

(Example 7)
Further, an optical film was prepared in the same manner as in Example 6 except that 10 parts of 2-hydroxyethyl methacrylate was added. Table 2 shows the optical properties of the optical film.

(Example 8)
Further, an optical film was prepared in the same manner as in Example 6 except that 5 parts of glycerin monomethacrylate was added. Table 2 shows the optical characteristics of the optical film.

Example 9
Further, an optical film was prepared in the same manner as in Example 6 except that 10 parts of isobornyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 10)
Further, an optical film was prepared in the same manner as in Example 6 except that 10 parts of tricyclodecanyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 11)
Further, an optical film was prepared in the same manner as in Example 6 except that 10 parts of adamantyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 12)
Further, an optical film was prepared in the same manner as in Example 6 except that 10 parts of hydroxyadamantyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 13)
Further, an optical film was prepared in the same manner as in Example 6 except that 10 parts of norbornane lactone methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 14)
Further, an optical film was prepared in the same manner as in Example 9 except that 10 parts of 2-hydroxyethyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 15)
Further, an optical film was prepared in the same manner as in Example 10 except that 10 parts of 2-hydroxyethyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 16)
Further, an optical film was prepared in the same manner as in Example 11 except that 10 parts of 2-hydroxyethyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 17)
Further, an optical film was prepared in the same manner as in Example 13 except that 10 parts of 2-hydroxyethyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 18)
Further, an optical film was prepared in the same manner as in Example 9 except that 5 parts of glycerin monomethacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 19)
Further, an optical film was prepared in the same manner as in Example 10 except that 5 parts of glycerin monomethacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 20)
Further, an optical film was prepared in the same manner as in Example 11 except that 5 parts of glycerin monomethacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 21)
Further, an optical film was prepared in the same manner as in Example 13 except that 5 parts of glycerin monomethacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 22)
Further, an optical film was prepared in the same manner as in Example 11 except that 10 parts of 2- (dimethylamino) ethyl methacrylate [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 23)
Further, an optical film was prepared in the same manner as in Example 11 except that 10 parts of polypropylene glycol monomethyl ether [monomer (II)] was added. Table 2 shows the optical characteristics of the optical film.

(Example 24)
An optical film was prepared in the same manner as in Example 1 except that 80 parts of polyurethane urea 1 (20 parts as a nonvolatile content) was changed to 80 parts of polyurethane urea 4 (20 parts as a nonvolatile content). Table 3 shows the optical properties of the optical film.

(Example 25)
An optical film was prepared in the same manner as in Example 1 except that 80 parts of polyurethane urea 1 (20 parts as a nonvolatile content) was changed to 80 parts of polyurethane urea 5 (20 parts as a nonvolatile content). Table 3 shows the optical properties of the optical film.

(Example 26)
80 parts of polyurethane urea 1 (20 parts as non-volatile content) is changed to 80 parts of polyurethane urea 4 (20 parts as non-volatile content), 0.01 part of polyether-modified silicone oil SH8400 is added to MegaFuck F477 (perfluoroalkyl oligomer; An optical film was prepared in the same manner as in Example 4 except that the content was changed to 0.01 part (manufactured by DIC Corporation). Table 4 shows the optical properties of the optical film.

(Example 27)
80 parts of polyurethane urea 4 (20 parts as non-volatile content) was changed to 80 parts of polyurethane urea 5 (20 parts as non-volatile content), and 7.5 parts of N-vinylcarbazole [monomer (I)] was changed to 6.5 parts. An optical film was produced in the same manner as in Example 26 except for the change. Table 4 shows the optical properties of the optical film.

(Example 28)
Further, an optical film was prepared in the same manner as in Example 26 except that 10 parts of adamantyl methacrylate [monomer (II)] was added. Table 4 shows the optical properties of the optical film.

(Example 29)
Further, an optical film was prepared in the same manner as in Example 26 except that 10 parts of hydroxyadamantyl methacrylate [monomer (II)] was added. Table 4 shows the optical properties of the optical film.

(Example 30)
Further, an optical film was prepared in the same manner as in Example 26 except that 3 parts of glycerin monomethacrylate was added. Table 4 shows the optical properties of the optical film.

(Example 31)
Further, an optical film was prepared in the same manner as in Example 27 except that 10 parts of adamantyl methacrylate [monomer (II)] was added. Table 4 shows the optical properties of the optical film.

(Example 32)
Further, an optical film was prepared in the same manner as in Example 27 except that 10 parts of hydroxyadamantyl methacrylate [monomer (II)] was added. Table 4 shows the optical properties of the optical film.

(Example 33)
Further, an optical film was prepared in the same manner as in Example 27 except that 3 parts of glycerin monomethacrylate was added. Table 4 shows the optical properties of the optical film.

(Moisture and heat resistance test)
The obtained optical film was bonded to a glass substrate, and the retardation value (Re ³ ) at a wavelength of 550 nm of the optical film was measured. The optical film is put into a Hitachi thermostat (trade name: EC-15HHP, manufactured by Hitachi Air Conditioning System Co., Ltd.) (condition: dry bulb temperature 60 ° C., humidity 90%), and the retardation value (Re) at a wavelength of 550 nm after 500 hours have passed. ⁴ ) was measured. The phase difference fluctuation rate Δ ′ was calculated from the equation (B).
Δ ′ = (Re ⁴ −Re ³ ) / Re ³ (B)
○: Phase difference fluctuation rate Δ ′ is 5% or less. Good heat-and-moisture resistance ×: Phase difference variation rate Δ ′ exceeds 5%. The heat and humidity resistance is poor.

<Optical anisotropy>
The optical film of each example showed positive birefringence.

<Chromatic dispersion characteristics>
In the optical film of the example, the retardation value Re (ν) at the wavelength νnm of the light transmitted through the optical film satisfies the relationship of Re (450) <Re (550) <Re (650), and is in the visible region. (300-700 nm) was found to show upward dispersion in general.

<Photoelastic coefficient>
The optical films of the examples have a photoelastic coefficient of 30 × 10 ⁻¹² (/ Pa) or less, and the optical films of Examples 9 to 23 have a photoelastic coefficient of 20 × 10 ⁻¹² (/ Pa) or less. The optical films of Examples 11 to 13, 16 to 17, and 20 to 23 had a photoelastic coefficient of 15 × 10 ⁻¹² (/ Pa) or less. By adding monomer (II), the effect of reducing the photoelastic coefficient is sufficiently exerted, the birefringence due to the stress of the obtained optical film is extremely small, and the retardation value due to the shrinkage of the polarizing plate after bonding, etc. It was found that it is possible to obtain a film free from optical unevenness by suppressing light leakage caused by the change.

<Heat resistance test>
The retardation fluctuation rate Δ of each of the optical films of Examples was 5% or less, and the heat resistance was good.
<Moisture and heat resistance test>
The retardation fluctuation rate Δ ′ of the optical films of the examples was 5% or less, and the heat and humidity resistance was good.

  The optical film of the present invention has good heat resistance.

Claims (11)

  A polyurethane containing a resin containing a structural unit derived from polyurethane urea obtained by reacting a polyol (A), a polyisocyanate (B), a polyamine (C) and a hydroxyl group-containing acrylic compound (D), and a photopolymerization initiator, An optical film having a weight average molecular weight of urea of 70,000 to 110,000.   Polyurethane urea is a tie-force CS series CS-S-207 (trade name, manufactured by DIC Corporation), a tie-force CS series CS-S-208 (trade name, manufactured by DIC Corporation), or a tie-force CS series CS-. S-65 (trade name, manufactured by DIC Corporation), Tyforce CS series CS-S-070 (trade name, manufactured by DIC Corporation), or Tyforce CS series CS-S-100 (trade name, DIC ( The optical film according to claim 1, which is manufactured by KK The optical film according to claim 1 or 2, wherein the resin contains a structural unit derived from a monomer represented by the formula (I).

(In Formula (I), _{R 1} represents a hydrogen atom or a methyl group, _{R 2} represents a heterocyclic group of a cyclic hydrocarbon group or 4 to 20 carbon atoms having from 6 to 20 carbon atoms, cyclic hydrocarbons Group and heterocyclic group include a hydroxyl group, an oxo group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and glycidyloxy A group, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 1 to 12 carbon atoms, an amino group, an amino group substituted with one or two alkyl groups having 1 to 12 carbon atoms, or a halogen atom. The alkyl group, alkoxy group, aryl group, aralkyl group, acyl group and acyloxy group may be a hydroxyl group, an amino group, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, or 1 to 1 carbon atoms. 6 acyl In may be substituted.) The optical film according to claim 1, wherein the resin contains a structural unit derived from a monomer represented by the formula (II).

(In formula (II), R ₇ represents a hydrogen atom or a methyl group. R ₈ represents a hydrogen atom, a methyl group, an alkyl group having 2 to 18 carbon atoms, an alkylamino group having 2 to 6 carbon atoms, or a carbon number. Represents a cyclic hydrocarbon group of 6 to 20. The hydrogen atom contained in the alkyl group and the alkylamino group may be substituted with a hydroxyl group, an oxo group or a carboxyl group, and —CH contained in the alkyl group _2- may be replaced by -O-, -S- or -NH- The hydrogen atom contained in the cyclic hydrocarbon group is a hydroxyl group, an oxo group, an alkyl group having 1 to 12 carbon atoms, or a carbon number. The cyclic group may be substituted with an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an acyl group having 2 to 4 carbon atoms, or a halogen atom. Included in hydrocarbon groups —CH ₂ — may be replaced by —O—, —S— or —NH— The hydrogen atom contained in the alkyl group, alkoxy group, aryl group and aralkyl group is a hydroxyl group or a halogen atom. May be substituted with.) The optical film according to any one of claims 1 to 4, 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 optical film according to claim 1, which has optical biaxiality.   A phase difference plate comprising the optical film according to claim 1.   It is a manufacturing method of the optical film which manufactures the optical film in any one of Claims 1-6, Comprising: A polyol (A), polyisocyanate (B), polyamine (C), and a hydroxyl-containing acrylic compound (D) are made to react. Production of an optical film comprising a resin containing a structural unit derived from polyurethaneurea obtained and having a polyurethaneurea having a weight average molecular weight of 70,000 to 110,000, which is formed into a film and further stretched to obtain an optical film Method.   A resin containing a structural unit derived from polyurethane urea obtained by reacting a polyol (A), a polyisocyanate (B), a polyamine (C), and a hydroxyl group-containing acrylic compound (D), and the weight average molecular weight of the polyurethane urea is The method for producing an optical film according to claim 8, wherein a solution containing a composition of 70,000 to 110,000 is cast on a smooth surface and the solvent is distilled off to form a film and further stretched to obtain an optical film.   Obtained by reacting polyol (A), polyisocyanate (B), polyamine (C), and hydroxyl group-containing acrylic compound (D) as a raw material for an optical film having a heat resistance having a retardation variation Δ of 5% or less. Use of polyurethane urea having a weight average molecular weight of 70,000 to 110,000.   Obtained by reacting polyol (A), polyisocyanate (B), polyamine (C), and hydroxyl group-containing acrylic compound (D) as a raw material for an optical film having a resistance to moisture and heat having a retardation variation rate of 5% or less. Use of polyurethane urea having a weight average molecular weight of 70,000 to 110,000.