JP5566701B2 - Retardation film - Google Patents

Description

  The present invention relates to a retardation film, a method for producing the retardation film, and the composition for a retardation film.

In order to obtain good display performance in a liquid crystal display, a retardation film having a small photoelastic coefficient is required.
For example, the retardation film includes a structural unit derived from urethane acrylate obtained by reacting polyhexamethylene carbonate diol, 1,4-cyclohexanedimethanol, isophorone diisocyanate and 2-hydroxyethyl acrylate, and styrene-maleic anhydride. A film containing a structural unit derived from a copolymer is known (for example, see Patent Document 1). Moreover, as urethane acrylate, the urethane acrylate obtained by making tricyclodecane dimethanol, isophorone diisocyanate, and 2-hydroxyethyl acrylate react is known (for example, refer patent document 2).

Korean Patent Application Publication No. 10-2009-0068137 Japanese Patent Laying-Open No. 2005-255579

  Conventionally, a retardation film formed by curing urethane (meth) acrylate obtained by reacting tricyclodecane dimethanol, polyisocyanate, and hydroxy group-containing (meth) acrylate is known. The photoelastic coefficient was large and was not always satisfactory. An object of the present invention is to provide a retardation film having a small photoelastic coefficient.

  As a result of studying to solve the above-mentioned problems, the present inventors have found that the photoelastic coefficient is reduced by a retardation film that includes a structural unit derived from a specific urethane (meth) acrylate and is stretched, The present invention has been reached.

［式（１Ａ−１）中、Ａ^１及びＡ^２は、それぞれ独立して、−ＣＨ_２−、−ＮＲ^ａ−、−Ｏ−、又は−Ｓ−を表す。
Ｒ^ａは、水素原子又は炭素数１〜４のアルキル基を表す。
ｎ^３及びｎ^４は、は、それぞれ独立して、１〜３の整数を表す。］
［４］式（１Ａ）で表される化合物が、式（ｂ−１）〜式（ｂ−７）で表される化合物からなる群から選ばれる少なくとも１種である、前記［１］又は［２］記載の位相差フィルム。

［５］Ｗ^２及びＷ^３が、ともにシクロヘキサンジイル基である前記［１］又は［２］記載の位相差フィルム。
［６］Ｌ^３が、単結合、及び式（１Ｂ−１）〜式（１Ｂ−５）で表される基からなる群から選ばれる１種の基である前記［１］又は［２］記載の位相差フィルム。

［式（１Ｂ−１）〜式（１Ｂ−５）中、＊は結合手を表す。］
［７］式（１Ｂ）で表される化合物が、式（ｂ−８）で表される化合物及び式（ｂ−９）で表される化合物からなる群から選ばれる少なくとも１種である、前記［１］〜［６］のいずれかに記載の位相差フィルム。

［８］ポリイソシアネート化合物（２）が、シクロヘキサン環を有する化合物である前記［１］〜［７］のいずれかに記載の位相差フィルム。
［９］ポリイソシアネート化合物（２）が、式（ａ−１）〜式（ａ−３）で表される化合物からなる群から選ばれる少なくとも１種である前記［１］〜［８］のいずれかに記載の位相差フィルム。

［１０］化合物（３）が、ヒドロキシ基を有するアクリレート及びヒドロキシ基を有するメタクリレートからなる群から選ばれる少なくとも１種である前記［１］〜［９］のいずれかに記載の位相差フィルム。
［１１］ポリアミン化合物が、脂環式炭化水素構造を有する化合物である前記［２］〜［１０］のいずれかに記載の位相差フィルム。
［１２］化合物（Ａ）の数平均分子量が、５，０００以上５００，０００以下であり、かつ化合物（Ａ）のガラス転移温度が６０℃以上２００℃以下である、前記［１］〜［１１］のいずれかに記載の位相差フィルム。
［１３］式（Ｉ）で表される化合物に由来する構造単位をさらに含む前記［１］〜［１２］のいずれかに記載の位相差フィルム。

［式（Ｉ）中、Ｒ^１は、水素原子又はメチル基を表す。
Ｒ^２は、置換基を有していてもよい炭素数６〜２０の環式炭化水素基又は置換基を有していてもよい炭素数４〜２０の複素環基を表す。］
［１４］式（Ｉ）で表される化合物が、Ｎ−ビニルカルバゾールである前記［１３］記載の位相差フィルム。
［１５］位相差フィルムを透過する透過光の波長νｎｍにおける位相差値Ｒｅ（ν）が、下記式を充足する前記［１］〜［１４］のいずれかに記載の位相差フィルム。
Ｒｅ（４５０）＜Ｒｅ（５５０）＜Ｒｅ（６５０）
［１６］式（１Ａ）及び式（１Ｂ）で表される化合物からなる群から選ばれる１種以上のジオール化合物（１）と、脂環式炭化水素骨格を有するポリイソシアネート化合物（２）とを反応させ、次いで、ポリイソシアネート化合物（２）のイソシアナト基と反応しうる官能基及びエチレン性二重結合を有する化合物（３）を反応させて得られる化合物（Ａ）、並びに、式（Ｉ）で表される化合物を含むモノマー及び式（Ｉ）で表される化合物を含むモノマーに由来する構造単位を有する樹脂からなる群から選ばれる少なくとも１種を含む位相差フィルム用組成物。

ＨＯ−Ｌ^１−Ｗ^１−Ｌ^２−ＯＨ （１Ａ）
ＨＯ−Ｗ^２−Ｌ^３−Ｗ^３−ＯＨ （１Ｂ）

［式（１Ａ）及び式（１Ｂ）中、Ｗ¹は、炭素数８〜１２の２価の橋かけ環炭化水素基又はスピロ炭化水素基を表し、該橋かけ環炭化水素基及び該スピロ炭化水素基に含まれる−ＣＨ_２−は、−ＮＨ−、−Ｏ−、又は−Ｓ−で置換されていてもよい。
Ｌ^１及びＬ^２は、それぞれ独立して、単結合、又は炭素数１〜４の２価の脂肪族炭化水素基を表す。
Ｌ^３は単結合、炭素数１〜９の２価の脂肪族炭化水素基又は炭素数３〜９の２価の脂環式炭化水素基を表す。
Ｗ^２及びＷ^３は、それぞれ独立して、炭素数１〜３のアルキル基で置換されていてもよい炭素数５〜７の２価の脂環式炭化水素基を表す。］

［式（Ｉ）中、Ｒ^１は、水素原子又はメチル基を表す。
Ｒ^２は、置換基を有していてもよい炭素数６〜２０の環式炭化水素基又は置換基を有していてもよい炭素数４〜２０の複素環基を表す。］
［１７］重合開始剤をさらに含む前記［１６］記載の位相差フィルム用組成物。
［１８］溶剤をさらに含む前記［１６］又は［１７］記載の位相差フィルム用組成物。
［１９］前記［１６］〜［１８］のいずれかに記載の位相差フィルム用組成物を支持体にキャストし、乾燥し、さらに延伸する位相差フィルムの製造方法。 That is, the present invention provides the following [1] to [19].
[1] One or more diol compounds (1) selected from the group consisting of compounds represented by formula (1A) and formula (1B), and a polyisocyanate compound (2) having an alicyclic hydrocarbon skeleton A structural unit derived from the compound (A) obtained by reacting and then reacting the compound (3) having a functional group capable of reacting with an ethylenic double bond and an isocyanate group of the polyisocyanate compound (2), Stretched retardation film.

^{HO-L 1 -W 1 -L 2} -OH (1A)
^{HO-W 2 -L 3 -W 3} -OH (1B)

[In Formula (1A) and Formula (1B), W ¹ represents a divalent bridged ring hydrocarbon group or spiro hydrocarbon group having 8 to 12 carbon atoms, and the bridged ring hydrocarbon group and the spiro hydrocarbon group. —CH ₂ — contained in the hydrogen group may be substituted with —NH—, —O—, or —S—.
L ¹ and L ² each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a single bond, a divalent aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms.
W ² and W ³ each independently represent a C 5-7 divalent alicyclic hydrocarbon group which may be substituted with a C 1-3 alkyl group. ]
[2] Compound (A) reacts with diol compound (1), polyisocyanate compound (2), and polyamine compound, and then reacts with an ethylenic double bond and an isocyanate group of polyisocyanate compound (2). The retardation film according to [1], which is a compound obtained by reacting a compound having a functional group capable of reaction.
[3] The retardation film according to [1] or [2], wherein the compound represented by the formula (1A) is a compound represented by the formula (1A-1).

[In Formula (1A-1), A ¹ and A ² each independently represent —CH ₂ —, —NR ^a —, —O—, or —S—.
R ^a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
n ³ and ^{n 4} are each independently represents an integer of 1 to 3. ]
[4] The above [1] or [1], wherein the compound represented by formula (1A) is at least one selected from the group consisting of compounds represented by formula (b-1) to formula (b-7) 2] Retardation film of description.

[5] The retardation film according to [1] or [2], wherein both W ² and W ³ are cyclohexanediyl groups.
[6] The above [1] or [2], wherein L ³ is a single bond and one group selected from the group consisting of groups represented by formulas (1B-1) to (1B-5) Retardation film.

[In formula (1B-1) to formula (1B-5), * represents a bond. ]
[7] The compound represented by formula (1B) is at least one selected from the group consisting of a compound represented by formula (b-8) and a compound represented by formula (b-9), The retardation film according to any one of [1] to [6].

[8] The retardation film according to any one of [1] to [7], wherein the polyisocyanate compound (2) is a compound having a cyclohexane ring.
[9] Any of [1] to [8], wherein the polyisocyanate compound (2) is at least one selected from the group consisting of compounds represented by formulas (a-1) to (a-3). The retardation film of crab.

[10] The retardation film according to any one of [1] to [9], wherein the compound (3) is at least one selected from the group consisting of an acrylate having a hydroxy group and a methacrylate having a hydroxy group.
[11] The retardation film according to any one of [2] to [10], wherein the polyamine compound is a compound having an alicyclic hydrocarbon structure.
[12] The number average molecular weight of the compound (A) is from 5,000 to 500,000, and the glass transition temperature of the compound (A) is from 60 ° C. to 200 ° C. [1] to [11] ] The retardation film in any one of.
[13] The retardation film according to any one of [1] to [12], further including a structural unit derived from the compound represented by the formula (I).

[In Formula (I), R ¹ represents a hydrogen atom or a methyl group.
R ² represents a cyclic hydrocarbon group or have a substituent good 4 to 20 carbon atoms the heterocyclic group having 6 to 20 carbon atoms which may have a substituent. ]
[14] The retardation film according to [13], wherein the compound represented by the formula (I) is N-vinylcarbazole.
[15] The retardation film according to any one of [1] to [14], wherein a retardation value Re (ν) at a wavelength νnm of transmitted light that passes through the retardation film satisfies the following formula.
Re (450) <Re (550) <Re (650)
[16] One or more diol compounds (1) selected from the group consisting of compounds represented by formula (1A) and formula (1B), and a polyisocyanate compound (2) having an alicyclic hydrocarbon skeleton. A compound (A) obtained by reacting and then reacting a compound (3) having an ethylenic double bond and a functional group capable of reacting with the isocyanato group of the polyisocyanate compound (2), and the formula (I) A composition for a retardation film comprising at least one selected from the group consisting of a monomer comprising a compound represented by formula (I) and a resin having a structural unit derived from a monomer comprising a compound represented by formula (I).

^{HO-L 1 -W 1 -L 2} -OH (1A)
^{HO-W 2 -L 3 -W 3} -OH (1B)

[In Formula (1A) and Formula (1B), W ¹ represents a divalent bridged ring hydrocarbon group or spiro hydrocarbon group having 8 to 12 carbon atoms, and the bridged ring hydrocarbon group and the spiro hydrocarbon group. —CH ₂ — contained in the hydrogen group may be substituted with —NH—, —O—, or —S—.
L ¹ and L ² each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a single bond, a divalent aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms.
W ² and W ³ each independently represent a C 5-7 divalent alicyclic hydrocarbon group which may be substituted with a C 1-3 alkyl group. ]

[In Formula (I), R ¹ represents a hydrogen atom or a methyl group.
R ² represents a cyclic hydrocarbon group or have a substituent good 4 to 20 carbon atoms the heterocyclic group having 6 to 20 carbon atoms which may have a substituent. ]
[17] The retardation film composition according to [16], further including a polymerization initiator.
[18] The retardation film composition according to [16] or [17], further including a solvent.
[19] A method for producing a retardation film, wherein the composition for retardation film according to any one of [16] to [18] is cast on a support, dried, and further stretched.

  According to the retardation film of the present invention, the photoelastic coefficient can be reduced.

In this specification, the retardation film is a film having an optical function used for converting linearly polarized light into circularly polarized light or elliptically polarized light, or conversely converting circularly polarized light or elliptically polarized light into linearly polarized light. Say.
The structural unit is a minimum unit that exhibits a predetermined birefringence, and means a unit derived from a compound.
In addition, when exhibiting the predetermined birefringence, when a layer obtained from a resin containing a predetermined structural unit is stretched, the refractive index in the stretched direction (± 10 °) becomes maximum (positive), or It means that the refractive index in the direction perpendicular (± 10 °) to the stretched direction becomes maximum (negative) or the like.
In this specification, (meth) acrylic acid includes both acrylic acid and methacrylic acid.

The retardation film of the present invention includes at least one diol compound (1) selected from the group consisting of compounds represented by formulas (1A) and (1B), and a polyisocyanate compound having an alicyclic hydrocarbon skeleton. Derived from the compound (A) obtained by reacting (2) with the compound (3) having a functional group capable of reacting with the ethylenic double bond and the isocyanate group of the polyisocyanate compound (2). Includes structural units.

^{HO-L 1 -W 1 -L 2} -OH (1A)
^{HO-W 2 -L 3 -W 3} -OH (1B)

[In Formula (1A) and Formula (1B), W ¹ represents a divalent bridged ring hydrocarbon group or spiro hydrocarbon group having 8 to 12 carbon atoms, and the bridged ring hydrocarbon group and the spiro hydrocarbon group. —CH ₂ — contained in the hydrogen group may be substituted with —NH—, —O—, or —S—.
L ¹ and L ² each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a single bond, a divalent aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms.
W ² and W ³ each independently represent a C 5-7 divalent alicyclic hydrocarbon group which may be substituted with a C 1-3 alkyl group. ]

  Compound (A) is one or more diol compounds (1) selected from the group consisting of the compounds represented by Formula (1A) and Formula (1B) (hereinafter sometimes referred to as Compound (1)), Reaction with a polyisocyanate compound (2) having an alicyclic hydrocarbon skeleton (hereinafter sometimes referred to as compound (2)), followed by an ethylenic double bond and an isocyanate group of polyisocyanate compound (2) It can be obtained by reacting a compound (3) having a functional group capable of reacting (hereinafter sometimes referred to as compound (3)).

W ¹ is a divalent bridged ring hydrocarbon group or spiro hydrocarbon group having 8 to 12 carbon atoms, and —CH ₂ — contained in the bridged ring hydrocarbon group and the spiro hydrocarbon group is — It may be substituted with NH-, -O-, or -S-.
Examples of the divalent bridged ring hydrocarbon group having 8 to 12 carbon atoms include a norbornanediyl group, a norbornenediyl group, a tricyclodecanediyl group, a bicyclo [3.3.0] octanediyl group, and a bicyclo [4.4. 0] A decanediyl group, an adamantanediyl group, and the like.
Examples of the divalent spiro hydrocarbon group having 8 to 12 carbon atoms include a spiro [3.3] octanediyl group and a spiro [5.5] undecandiyl group.

L ¹ and L ² are each independently a single bond or a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms.
Examples of the divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, and a butane-1,4-diyl group. Group, butane-1,3-diyl group and the like.

L ³ is a single bond, a divalent aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms.
Examples of the divalent aliphatic hydrocarbon group having 1 to 9 carbon atoms include, in addition to those exemplified in the above L ¹ and L ² , a pentane-1,5-diyl group, a hexane-1,6-diyl group, Examples include heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group and the like.
Examples of the divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms include cyclopropanediyl group, cyclobutanediyl group, cyclopentanediyl group, cyclohexanediyl group, methylcyclohexanediyl group, and trimethylcyclohexanediyl group. It is done. Among these, groups represented by formula (1B-1) to formula (1B-5) are preferable.

W ² and W ³ are each independently a divalent alicyclic hydrocarbon group having 5 to 7 carbon atoms which may be substituted with an alkyl group having 1 to 3 carbon atoms.
Examples of the divalent alicyclic hydrocarbon group having 5 to 7 carbon atoms include a cyclopentanediyl group, a cyclohexanediyl group, and a cycloheptanediyl group.
Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a propyl group, and an isopropyl group.
Examples of the divalent alicyclic hydrocarbon group having 5 to 7 carbon atoms substituted with an alkyl group having 1 to 3 carbon atoms include, for example, a methylcyclopentanediyl group, an ethylcyclopentanediyl group, an ethylcyclohexanediyl group, and the like. Is mentioned.
W ² and W ³ are preferably both cyclohexanediyl.

［式（１Ａ−１）中、Ａ^１及びＡ^２は、それぞれ独立して、−ＣＨ_２−、−ＮＲ^ａ−、−Ｏ−、及び−Ｓ−からなる群から選ばれる少なくとも１種である。
Ｒ^ａは、水素原子又は炭素数１〜４のアルキル基である。
ｎ^３及びｎ^４は、それぞれ独立して、１〜３の整数である。］ As a compound represented by Formula (1A), the compound represented by Formula (1A-1) is mentioned, for example.

[In Formula (1A-1), A ¹ and A ² are each independently at least one selected from the group consisting of —CH ₂ —, —NR ^a —, —O—, and —S—. .
R ^a is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
n ³ and ^{n 4} are each independently an integer of 1 to 3. ]

Examples of the alkyl group having 1 to 4 carbon atoms in ^Ra include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group.

Specific examples of the compound represented by the formula (1A) include tricyclo [5.2.1.0 ^2,6 ] decane dimethanol (common name: tricyclodecane dimethanol), 1,4-decahydronaphthalenediol. 1,5-decahydronaphthalenediol, 1,6-decahydronaphthalenediol, 2,6-decahydronaphthalenediol, 2,7-decahydronaphthalenediol, decahydronaphthalenediethanol, norbornanediol, norbornanedimethanol, Decalin dimethanol, adamantanediol, adamantanetriol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane (common name; spiroglycol) ), Isosorbide, isomannide and the like.

  Specific examples of the compound represented by Formula (1A-1) include compounds represented by Formula (b-1) to Formula (b-5). As the compound represented by the formula (b-1), isosorbide, isomannide and the like are preferable.

Furthermore, as a compound represented by Formula (1A), the compound etc. which are represented by Formula (b-6) and Formula (b-7) other than the above are mentioned preferably.

  Specific examples of the compound represented by the formula (1B) include 2,2-bis (4-hydroxycyclohexyl) propane (common name; hydrogenated bisphenol A), 4,4'-dihydroxydicyclohexylmethane (common name; hydrogenated). Bisphenol F), 1,1-bis (4-hydroxycyclohexyl) -1,1-dicyclohexylmethane (common name; hydrogenated bisphenol Z), 4,4-bicyclohexanol, a compound represented by formula (b-8), The compound etc. which are represented by a formula (b-9) are mentioned.

  In the reaction for obtaining the compound (A), the compound (1) and another diol may be used in combination. For example, the compound (1) may be used in combination with a high molecular weight diol having a number average molecular weight of 400 or more. For example, polyester diol, polyether diol, polycarbonate diol, silicone diol, polyolefin diol, and copolymers thereof. Can be used. By combining the compound (1) and the high molecular weight diol, the flexibility and heat resistance of the resulting film can be improved.

  The high molecular weight diol is preferably a polyester diol having at least one selected from the group consisting of an aliphatic skeleton, an alicyclic skeleton, and a saturated heterocyclic skeleton, and / or a polycarbonate diol. The number average molecular weight of the high molecular weight diol is preferably 400 or more and 5000 or less, and more preferably 400 or more and 2000 or less. Further, it is particularly preferably 400 or more and 1500 or less. It is preferable for the number average molecular weight of the high molecular weight diol to be in the above range since the reactivity with the polyisocyanate compound is good and the flexibility suitable for the retardation film of the present invention is imparted.

Examples of the polyester diol include at least one 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. Examples thereof include those obtained by reacting a kind of dicarboxylic acid with a low molecular weight diol. As another method, lactone compounds such as β-propiolactone, pivalolactone, δ-valerolactone, methyl-δ-valerolactone, ε-caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, trimethyl-ε-caprolactone, etc. Can be reacted with a low molecular weight diol.
Examples of the polyether diol include polytetramethylene glycol, polyethylene glycol, polypropylene glycol, and polyoxypropylene glycol.

  Examples of the polycarbonate diol include those obtained by a transesterification method from a compound selected from the group consisting of low molecular weight diols and diallyl carbonate, dialkyl carbonate, and ethylene carbonate. Specific examples include poly-1,6-hexamethylene carbonate, poly-2,2'-bis (4-hydroxyhexyl) propane carbonate, poly-1,4-cyclohexanedimethylene carbonate, and the like.

  As the high molecular weight diol, polycarbonate diol is preferred. The use of polycarbonate diol is preferable because toughness can be imparted to the film while maintaining heat resistance and light resistance, and processability is improved.

  When the compound (1) and the high molecular weight diol are used in combination, the amount of the high molecular weight diol used is preferably 20 mol% or less with respect to the total amount of the compound (1) and the high molecular weight diol.

  The polyisocyanate compound (2) having an alicyclic hydrocarbon skeleton refers to a compound having an alicyclic hydrocarbon skeleton and two or more isocyanato groups. Among these, a compound having a cyclohexane ring and two or more isocyanato groups is preferable, and a compound having a cyclohexane ring and two isocyanato groups is more preferable.

Specific examples of the compound (2) include isophorone diisocyanate, hydrogenated tolylene diisocyanate (common name; hydrogenated TDI), 1,3-bis (isocyanatomethyl) cyclohexane (common name; hydrogenated XDI), bis ( 4-isocyanatocyclohexyl) methane (common name; hydrogenated MDI), decahydronaphthylene 1,5-diisocyanate (common name; hydrogenated NDI), 1,3-bis (2-isocyanato-2-propyl) cyclohexane (common name; Hydrogenated m-TMXDI), 1,4-bis (2-isocyanato-2-propyl) cyclohexane (common name; hydrogenated p-TMXDI), 1,2-diisocyanate cyclohexane, 1,3-diisocyanate cyclohexane, 1,4- Diisocyanate cyclohexane, 2,4,4-trimethylcyclohexane diisocyanate Over DOO, 2,2,4-trimethyl-cyclohexane diisocyanate, norbornane diisocyanate, hydrogenated triphenylmethane triisocyanate, hydrogenated tris (isocyanatophenyl) thiophosphate, bicycloheptane triisocyanate and the like.
Among them, isophorone diisocyanate (compound represented by formula (a-1)), bis (4-isocyanatocyclohexyl) methane (compound represented by formula (a-2)), 1,3-bis (isocyanatomethyl) ) Cyclohexane (compound represented by formula (a-3)) is preferred.

  The amount of compound (2) used is 100 mol% or more and 110 mol% or less, preferably 100.05 mol% or more and 107 mol% or less, more preferably 100.1 mol% or more and 105 mol%, relative to compound (1). It is as follows. When the amount of the compound (2) used is in the above range, it is preferable because the compound (A) having a high polymerization degree tends to be obtained without being easily clouded or solidified.

  Examples of the functional group capable of reacting with the isocyanato group included in the compound (3) having an ethylenic double bond and a functional group capable of reacting with the isocyanato group of the compound (2) include a hydroxy group, a carboxy group, an amino group, and sulfanyl. And functional groups having active hydrogen such as groups. Of these, a hydroxy group is preferred.

The compound (3) having a functional group capable of reacting with an isocyanato group and an ethylenic double bond (3) is at least one selected from the group consisting of a (meth) acrylate compound having a hydroxy group and a (meth) acrylamide compound having a hydroxy group. A seed compound is preferred. From the viewpoint of reactivity, a (meth) acrylate compound having a hydroxy group is more preferable, and monohydroxyalkyl mono (meth) acrylate is more preferable.
It is preferable that the reactivity is excellent because the residual monomer is reduced and the compound (A) can be obtained in a good yield. When the compound (A) having a small amount of residual monomer is used, a retardation film having excellent temporal stability and durability can be produced.

Examples of the monohydroxyalkyl mono (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy-1-methylethyl (meta ) Acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, [4- (hydroxymethyl) cyclohexyl] methyl (meth) acrylate, 3-hydroxy-1-adamantyl (meth) acrylate, and the like. It is done. Of these, 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate are preferable.
Examples of the (meth) acrylamide having a hydroxy group include N-methylol (meth) acrylamide and N-hydroxyethyl (meth) acrylamide. Of these, N-hydroxyethylacrylamide is preferred.

  The amount of the compound (3) used is 0.1 mol% or more and 30 mol% or less, preferably 0.5 mol% or more and 20 mol% or less, more preferably 1 mol% or more and 10 mol%, relative to the diol compound (1). It is as follows. It is preferable that the amount of compound (3) used be in the above-mentioned range since the residual monomer is reduced and compound (A) can be obtained in good yield. When the compound (A) having a small amount of residual monomer is used, a retardation film having excellent temporal stability and durability can be produced.

  The compound (A) may be a compound obtained by reacting the compound (1), the compound (2), and a polyamine compound and then reacting the compound (3).

A polyamine compound refers to a compound having two or more amino groups. Examples of the polyamine compound include aromatic polyamine compounds, aliphatic polyamine compounds, and alicyclic polyamine compounds.
An aromatic polyamine compound is an aromatic compound having two or more amino groups. For example, tolylenediamine, phenylenediamine, diaminodiphenylmethane, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3, Examples include 5-triethyl-2,6-diaminobenzene, 3,5,3 ′, 5′-tetraethyl-4,4′-diaminodiphenylmethane, and the like.
An aliphatic polyamine compound is an aliphatic compound having two or more amino groups. For example, ethylenediamine, propylenediamine, hexamethylenediamine and the like can be mentioned.
An alicyclic polyamine compound is an alicyclic compound having two or more amino groups. For example, di (4-aminocyclohexyl) methane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,2-bis (aminomethyl) cyclohexane, 1,3-bis (amino) And methyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, and 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine).
Of these, aliphatic polyamine compounds and alicyclic polyamine compounds are preferred because they have excellent stability over time as a solution of the obtained compound (A) and tend to reduce coloration such as yellowing. In particular, an alicyclic polyamine compound is more preferred because the retardation development property and durability of the produced retardation film tend to be good.

  The amount of the polyamine compound used is 20 mol% or less, preferably 15 mol% or less, more preferably 10 mol% or less, relative to the amount of the compound (2). It is preferable that the amount of the polyamine compound used be in the above range because the compound (A) is less likely to solidify or become cloudy.

  In particular, polyurethane obtained by polyaddition reaction of isophorone diisocyanate and isosorbide, and polyurethane acrylate obtained by reacting 2-hydroxyethyl acrylate with polyurethane obtained by polyaddition reaction of isophorone diisocyanate and isosorbide are novel compounds. .

  In particular, polyurethane urea obtained by reacting isophorone diamine with isophorone diamine and polyurethane obtained by polyaddition reaction of isophorone diisocyanate and isosorbide, and obtained by reacting isophorone diamine with polyurethane obtained by polyaddition reaction of isophorone diisocyanate and isosorbide. Polyurethane urea acrylate obtained by further reacting polyurethane urea with 2-hydroxyethyl acrylate is a novel compound.

  As a production method of the compound (A), a compound obtained by reacting the compound (1) and the compound (2) with a compound (3), a compound (1), a compound (2), Examples thereof include a method of reacting compound (3) with a compound obtained by reacting with a polyamine compound.

  The polyaddition reaction or the like, which is a method for producing the compound (A), 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 the isocyanato group. For example, hydrocarbons such as toluene, xylene, chlorobenzene, mineral terpenes; ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, methyl glycol acetate, propylene glycol monomethyl ether acetate, cellosolve acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, Examples thereof include ketone solvents such as cyclopentanone and cyclohexanone. 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.

  When using an organic solvent in the production of the compound (A), it is preferable to use a solvent subjected to dehydration treatment. Dehydration may be performed using molecular sieve 3A or the like, or the solvent may be dehydrated by distillation. For example, when using ethyl acetate, cyclohexanone, methyl isobutyl ketone, etc., these solvents and calcium hydride powder are mixed at room temperature, stirred in a suspended state for 2 to 12 hours at room temperature, and then mixed with nitrogen or argon. It can be dehydrated by heating and distilling at a temperature 10 to 20 ° C. higher than the boiling point under an active gas stream. In addition, a solvent such as tetrahydrofuran is benzophenone and sodium pieces added to these solvents at room temperature and stirred vigorously, and is 10-20 ° C. higher than the boiling point in an inert gas stream such as nitrogen or argon while maintaining a dark purple solution state. It can be dehydrated by heating at temperature and distilling. A commercially available dehydrated solvent may be used. It is preferable to perform a dehydration treatment because a side reaction between the isocyanato group and moisture can be suppressed and a high molecular weight compound (A) can be obtained.

  When the organic solvent is used, the amount of the organic solvent used is 10 to 60% by mass, preferably 15 to 50% by mass, based on the total amount of the reaction mixture.

  In the production of the compound (A), in order to promote the reaction (urethanization reaction) between the compound (1) and the compound (2), a catalyst used in a known urethanization 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, these tertiary amines and organometallic catalysts may be used in combination. The amount of the catalyst used is about 0.001 mol% to 10 mol%, preferably about 0.01 mol% to 5 mol%, relative to 1 equivalent of compound (1).

  When the compound (3) is reacted, it is also preferable to use a polymerization inhibitor in order to suppress polymerization of the ethylenic double bond. 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, Phenothiazine, nitroso compound, etc. can be used. A polymerization inhibitor may use together 1 type (s) or 2 or more types. When the polymerization inhibitor is used, the amount used is generally 10 to 50000 ppm, preferably 50 to 1000 ppm, based on mass with respect to compound (1).

  The compound (A) preferably has a number average molecular weight in the range of 5,000 to 500,000 from the viewpoints of viscosity, solubility in a solvent, toughness of retardation film, workability, and optical properties. More preferably, it is in the range of 000 to 300,000, more preferably in the range of 10,000 to 200,000.

  It is preferable that the glass transition temperature of a compound (A) is the range of 60 to 200 degreeC.

  It is preferable for the number average molecular weight and glass transition temperature of the compound (A) to be in the above ranges because the heat resistance, shape stability, processability, stretchability and the like of the retardation film are excellent.

  In the retardation film of the present invention, the content of the structural unit derived from the compound (A) is 30% by mass to 100% by mass, preferably 40% by mass to 90% by mass, based on the total amount of all structural units. Preferably it is the range of 45 mass%-85 mass%. When the content of the structural unit derived from the compound (A) is within the above range, the photoelastic coefficient is small, and the retardation film tends to perform more uniform polarization conversion in a wide wavelength range. Therefore, it is preferable.

［式（Ｉ）中、Ｒ^１は、水素原子又はメチル基を表す。
Ｒ^２は、置換基を有していてもよい炭素数６〜２０の環式炭化水素基又は置換基を有していてもよい炭素数４〜２０の複素環基を表す。］ The retardation film of the present invention preferably further includes a structural unit derived from the compound represented by the formula (I).

[In Formula (I), R ¹ represents a hydrogen atom or a methyl group.
R ² represents a cyclic hydrocarbon group or have a substituent good 4 to 20 carbon atoms the heterocyclic group having 6 to 20 carbon atoms which may have a substituent. ]

The cyclic hydrocarbon group having 6 to 20 carbon atoms in R ² may be a monocyclic cyclic hydrocarbon group or a condensed cyclic hydrocarbon group. Examples of the cyclic hydrocarbon group having 6 to 20 carbon atoms include an alicyclic hydrocarbon group and an aromatic hydrocarbon group, and among them, an aromatic hydrocarbon group is preferable. 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.

Examples of the heterocyclic group having 4 to 20 carbon atoms include heterocyclic groups containing heteroatoms such as nitrogen atoms and oxygen atoms as constituent atoms of the ring. It may be a monocyclic heterocyclic group or a condensed heterocyclic group. Specific examples of such a heterocyclic ring include a pyrrole ring, a furan ring, a thiophene ring, a pyrazine ring, a pyrazoline ring, an imidazole ring, a pyridine ring, a piperidine ring, a piperazine ring, a tetrahydrofuran ring, an indole ring, a thiazoline ring, and a carbazole. A ring etc. are mentioned.
R ² is preferably an aromatic hydrocarbon group or a heterocyclic group.

  The cyclic hydrocarbon group and the heterocyclic group are a hydroxy group, an alkyl group having 1 to 12 carbon atoms (for example, a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an octyl group, etc.), Alkoxy groups (for example, methoxy group or ethoxy group), aryl groups having 6 to 12 carbon atoms (for example, phenyl group, naphthyl group, etc.), aralkyl groups having 7 to 12 carbon atoms (for example, benzyl group, etc.), 4 acyl groups (for example, acetyl groups), C1-C12 acyloxy groups (for example, acetyloxy groups), amino groups, amino groups substituted with one or two C1-C12 alkyl groups ( Substituted with at least one selected from the group consisting of, for example, an ethylamino group, a dimethylamino group, and the like, and a halogen atom (for example, a fluorine atom, a chlorine atom, or a bromine atom). It may be.

Specific examples of the compound represented by the formula (I) include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, o-ethylstyrene, and p-ethyl. Alkyl styrenes such as styrene, trimethyl styrene, propyl styrene, tert-butyl styrene, cyclohexyl styrene, dodecyl styrene;
Hydroxy styrene, t-butoxy styrene, vinyl benzoic acid, vinyl benzyl acetate, o-chloro styrene, p-chloro styrene, amino styrene, etc., hydroxy group, alkoxy group, carboxy group, acyloxy group, halogen and amino group on the benzene ring Substituted styrene having a group selected from
Vinylbiphenyl compounds such as 4-vinylbiphenyl, 2-ethyl-4benzylstyrene, 4- (phenylbutyl) styrene and 4-hydroxy-4′-vinylbiphenyl;
Compounds having a condensed ring and a vinyl group, such as vinylnaphthalene and vinylanthracene;
Examples thereof include compounds having a heterocyclic group and a vinyl group such as N-vinylpyrrolidone, N-vinylcarbazole, N-vinylpyridine, N-vinylphthalimide and N-vinylindole.

Among these, as the compound represented by the formula (I), styrene, N-vinylcarbazole, vinylnaphthalene and vinylanthracene are preferable, styrene and N-vinylcarbazole are more preferable, and N-vinylcarbazole is further preferable.
These compounds are preferable because the retardation film tends to enable more uniform polarization conversion in a wide wavelength range.
The compounds represented by formula (I) can be used alone or in combination of two or more.

  The content of the structural unit derived from the compound represented by the formula (I) is preferably 5 to 30% by mass with respect to 100% by mass of the total amount of all the structural units included in the retardation film of the present invention. Is 7 to 25% by mass, particularly preferably 10 to 25% by mass. When the content of the structural unit derived from the compound represented by the formula (I) is within the above range, it is preferable because uniform polarization conversion can be performed in a wide wavelength range.

In addition to the compound represented by the formula (I), the retardation film of the present invention may further use another compound having an ethylenic double bond.
For example, a compound represented by the formula (II) may be used in combination.

［式（ＩＩ）中、Ｒ^３は水素原子又はメチル基であり、好ましくはメチル基を表す。
Ｒ^４は、水素原子、炭素数１〜６のアルキル基、又は炭素数２〜６のアルキルアミノ基を表し、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、ヒドロキシ基、又はカルボキシ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−、−ＣＯ−、−Ｓ−又は−ＮＨ−で置換されていてもよい。］

[In Formula (II), R ³ represents a hydrogen atom or a methyl group, and preferably represents a methyl group.
R ⁴ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkylamino group having 2 to 6 carbon atoms, and the hydrogen atom contained in the alkyl group and the alkylamino group is a hydroxy group or a carboxy group. It may be substituted with a group, and —CH ₂ — contained in the alkyl group may be substituted with —O—, —CO—, —S— or —NH—. ]

  Specific examples of the compound represented by the formula (II) include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl. (Meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- (dimethylamino) ethyl (meth) acrylate, glycerin mono (meth) acrylate Etc.

  Among them, a film that can be copolymerized with the compound represented by the formula (I) without increasing the transmittance to increase the polymerization rate, improves the film formation uniformity of the composition, and has excellent smoothness. It is preferable that it is at least 1 sort (s) chosen from the group which consists of 2-hydroxyethyl methacrylate, 2- (dimethylamino) ethyl methacrylate, and glycerol monomethacrylate from the point which can be manufactured.

  The compounds represented by formula (II) can be used alone or in combination of two or more.

  The content of the structural unit derived from the compound represented by the formula (II) is preferably 0 to 50% by mass with respect to 100% by mass of the total amount of all the structural units contained in the retardation film of the present invention. Is 3 to 30% by mass, particularly preferably 5 to 25% by mass. When the content of the structural unit derived from the compound represented by the formula (II) is within the above range, the polymerization rate is increased by copolymerizing with the compound represented by the formula (I) without decreasing the transmittance. This is preferable. Moreover, since the film-forming uniformity of a composition can be improved and the retardation film excellent in smoothness can be produced, it is preferable.

The composition for retardation film of the present invention comprises a compound (A), a compound having a structural unit derived from a monomer containing the compound represented by formula (I) and the compound represented by formula (I). It is a composition containing at least 1 sort (s) chosen from.
The retardation film of the present invention can be obtained by forming a film for the composition for a retardation film of the present invention (hereinafter sometimes referred to as “the composition of the present invention”) and further stretching. Photopolymerization may be performed in the production process of the retardation film. The photopolymerization may be performed before stretching after film formation, may be performed while stretching after film formation, or may be performed after further stretching after film formation. In particular, it is preferable to obtain the film by casting on a support, drying to form a film, photopolymerizing, and further stretching.

The composition of the present invention may contain 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 sulfonium salts. Etc.
For example, IRGACURE 907, IRGACURE 184, IRGACURE 651, IRGACURE 250, IRGACURE 369, IRGACURE OXE01, IRGACURE OXE02 (all manufactured by Ciba Japan Co., Ltd.), Seiko All BZ, Seiko All Z, Seiko All BEE (all and above) Seiko Chemical Co., Ltd.), Kayacure BP100, Kayacure DETX-S, Kayacure CTX, Kayacure BMS (all from Nippon Kayaku Co., Ltd.), UVI-6992 (Dow), Adekaoptomer SP -150, Adekaoptomer SP-152, Adekaoptomer SP-172, Adekaoptomer N-1414, Adekaoptomer N-1606, Adekaoptomer N-1717, Adekaoptomer N- 919 (above all, Ltd. ADEKA) may be a commercially available product such as.

  Moreover, the usage-amount of a photoinitiator is the total amount of resin which has a structural unit derived from the compound containing the compound (A), the compound represented by Formula (I), and the compound represented by Formula (I). Is 0.1% by mass to 10% by mass, preferably 0.5% by mass to 5% by mass. When the amount of the photopolymerization initiator is within the above range, the ethylenic double bond of the compound represented by the compound (A) or the formula (I) can be polymerized without decreasing the transmittance. It is possible and preferable. Further, the polymerization tends to improve optical properties such as retardation development, heat resistance, transmittance, and the like, which is preferable.

  The composition of the present invention contains a polymerization inhibitor in order to control the photopolymerization reactivity of the compound represented by the compound (A) or the formula (I) and improve the storage stability of the obtained retardation film. You may go out. 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 or β-naphthols.

  The amount of the polymerization inhibitor used is based on the total amount of the compound (A), the compound represented by the formula (I) and the resin having a structural unit derived from the monomer containing the compound represented by the formula (I). And 0.1 mass% to 30 mass%, preferably 0.5 mass% to 10 mass%. When the amount of the polymerization inhibitor is within the above range, the monomer can be polymerized without decreasing the transmittance, which is preferable.

  The composition of the present invention may contain a photosensitizer in order to increase 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 amount of the photosensitizer used is the total amount of the compound (A) and the resin having a structural unit derived from a monomer containing the compound represented by formula (I) and the compound represented by formula (I). On the other hand, it is 0.1 mass%-30 mass%, for example, Preferably it is 0.5 mass%-10 mass%. When the amount of the photosensitizer used is within the above range, it is preferable because the monomer can be polymerized with high sensitivity without decreasing the transmittance.

  The composition of the present invention may contain a solvent. Examples of the 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 amount of the solvent used is based on the total amount of the compound (A) and the resin having a structural unit derived from a monomer containing the compound represented by the formula (I) and the compound represented by the formula (I). For example, it is 50 mass%-90 mass%, Preferably it is 60 mass%-80 mass%. It is preferable that the amount of the solvent used be in the above range because the compatibility of components other than the solvent contained in the composition of the present invention is improved and a film excellent in smoothness can be produced.

  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 (trade name) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Ltd.) Name) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-477, F-479 F-482, F-482 (all are manufactured by DIC Corporation), Ftop (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) (Trade name) E1830, E5844 (made by Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100 (all trade names: manufactured by BM Chemie), and the like. The leveling agents may be used alone or in combination of two or more.

By using a leveling agent, the resulting film (membrane) can be smoothed. Furthermore, in the production process of film formation, the fluidity of the composition can be controlled, and the crosslinking density of the film obtained by polymerizing the composition can be adjusted.
The content of the leveling agent is the total amount of the compound (A), the compound represented by the formula (I) and the resin having a structural unit derived from the monomer containing the compound represented by the formula (I) and the photopolymerization initiator. Is 0.0001% by mass to 2.0% by mass, and preferably 0.0005% by mass to 1.0% by mass. When the content of the leveling agent is within the above range, a film (film) excellent in smoothness can be obtained without reducing the transmittance.

  The composition of the present invention 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.

  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.

Carboxylic acid esters 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 are also preferred.

  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.

  You may use a plasticizer individually or in combination of 2 or more types, respectively. The addition amount of the plasticizer may be appropriately selected within a range that does not greatly impair the retardation film characteristics of the present invention. For example, the compound (A), the compound represented by the formula (I), and the formula (I) 0.1% by mass to 30% by mass is preferable with respect to 100% by mass of the total amount of the resin having a structural unit derived from the monomer containing the compound to be produced and the photopolymerization initiator.

  The retardation film of the present invention is produced by forming the film of the composition of the present invention to form a film-like material, and further stretching the obtained film-like material. Alternatively, the retardation film of the present invention is produced by forming a film of the composition (forming a film), photopolymerizing to form a film-like product, 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 formed as it is.

  The light source used for photopolymerization is preferably a light source that generates ultraviolet light (UV). For example, a fluorescent chemical lamp, a black light, a low pressure, a high pressure, an ultrahigh pressure mercury lamp, a metal halide lamp, sunlight, an electrodeless lamp, and the like can be given. 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 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, since the productivity is good, lateral uniaxial stretching and biaxial stretching are preferable, and lateral uniaxial stretching is particularly preferable.
A retardation 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 retardation value Re (ν) at the wavelength νnm of the light transmitted through the retardation film usually satisfies the relationship of Re (450) <Re (550) <Re (650). By increasing and exhibiting upwardly rising dispersion in the entire visible region of 300 to 700 nm, uniform polarization conversion can be performed in a wide wavelength region.

ここでΔαは分極率異方性、ｎは屈折率、ｋはボルツマン定数を表す。
光弾性係数と複屈折発現性とは下記式の関係がある。
Δｎ_ｓｔ＝Ｃ・σ
ここでΔｎ_ｓｔは応力複屈折、σは応力を表す。上式が示すように光弾性係数Ｃが大きい場合、σによって誘起されるΔｎ_ｓｔが大きくなる。このため光弾性係数が大きい材料の場合、外力によって位相差フィルムに生じる応力に起因する位相差変化が大きくなってしまい、表示性能の低下が発生する。
従って、位相差フィルムの光弾性係数は小さいほうが好ましく、具体的には、０Ｐａ^−１以上３０×１０^−１２Ｐａ^−１以下であることが好ましい。光弾性係数が３０×１０^−１２Ｐａ^−１以下であれば、良好な光学特性を示しつつ、且つ表示性能に優れた位相差フィルムが得られるため好ましい。 The photoelastic coefficient C is defined by the following formula.

Here, Δα represents the polarizability anisotropy, n represents the refractive index, and k represents the Boltzmann constant.
The photoelastic coefficient and birefringence developability have the following relationship.
Δn _st = C · σ
Here, Δn _st represents stress birefringence, and σ represents stress. As the above equation shows, when the photoelastic coefficient C is large, Δn _st induced by σ becomes large. For this reason, in the case of a material having a large photoelastic coefficient, a change in retardation due to a stress generated in the retardation film due to an external force becomes large, resulting in a decrease in display performance.
Accordingly, preferably more photoelastic coefficient of the retardation film small, specifically, is preferably ^{0 Pa -1} or 30 × ¹⁰ -12 ^{Pa -1} or less. A photoelastic coefficient of 30 × 10 ⁻¹² Pa ⁻¹ or less is preferable because a retardation film having excellent optical characteristics and excellent display performance can be obtained.

The glass transition temperature of the retardation film of the present invention is preferably in the range of 60 ° C to 200 ° C.
If the glass transition temperature of the retardation film of the present invention is too low, it is not preferable because the heat resistance and shape stability of the retardation film is poor, and if the glass transition temperature is too high, the workability and stretchability of the retardation film are poor. Therefore, it is not preferable. It is preferable that the glass transition temperature of the retardation film is in the above range because the optical film is excellent in heat resistance, shape stability, processability, stretchability, and the like.

Since the retardation film of the present invention has a small photoelastic coefficient and can perform uniform polarization conversion in a wider wavelength range, a retardation plate such as a λ / 2 plate and a λ / 4 plate, and a viewing angle improving film Etc. If the retardation 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 is combined with a linear polarizing plate. And a polarization rotation element having a wide wavelength range. 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 retardation film, and is capable of uniform polarization conversion in a wide wavelength range.

  Hereinafter, the present invention will be described in more detail with reference to examples. Unless otherwise specified, “%” and “parts” in the examples are% by mass and parts by mass. The average molecular weight was determined by the following method.

(Average molecular weight)
The average molecular weight was determined in terms of polystyrene using gel permeation chromatography (GPC) (manufactured by Tosoh Corporation, HLC-8220GPC).

Apparatus: HLC-8220GPC (manufactured by Tosoh Corporation)
Guard column: TSK guard column MP (XL) (trade name)
Column; TSK-gel MultiporeH _XL- M (trade name)
TSK-gel MultiporeH _XL- M (trade name)
TSK-gel MultiporeH _XL- M (trade name) (series connection)
Column temperature: 40 ° C
Solvent: THF
Flow rate: 1.0 mL / min
Injection volume: 50 μL
Detector: RI, UV
Measurement sample concentration: 0.6% (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, a thermometer and a reflux condenser, 21.92 parts of compound (b-1) (isosorbide: manufactured by Tokyo Chemical Industry Co., Ltd.), 2,6-di-tert-butyl-p-cresol 0.056 parts, 128 parts of methyl isobutyl ketone (molecular sieve 3A (manufactured by Wako Pure Chemical Industries, Ltd.)), 128 parts, 0.256 parts of dibutyltin dilaurate were charged, and the oil bath was stirred under a nitrogen stream. The mixture was heated to reflux at 120 ° C. to completely dissolve the compound (b-1). Subsequently, 34.68 parts of compound (a-1) (isophorone diisocyanate: manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 30 minutes using a dropping funnel, and reacted at 120 ° C. for 4 hours after completion of the dropping. 35.8 parts of N, N-dimethylformamide (dehydrated) (manufactured by Kanto Chemical Co., Inc.) was added and stirred vigorously, and further reacted at 120 ° C. for 4 hours. After cooling the reaction solution to about 50 ° C., 3.48 parts of 2-hydroxyethyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) is added and stirred vigorously, followed by 20.6 parts of 2-propanol and stirred vigorously. did. The mixture was allowed to cool to room temperature to obtain a compound (A1) solution (solid content: 25%).
As a result of measuring the molecular weight, the compound (A1) had a number average molecular weight of 36,400 and a molecular weight distribution of 1.66.

(Synthesis Example 2)
In a reaction vessel equipped with a stirrer, a thermometer and a reflux condenser, 24.04 parts of compound (b-8) (hydrogenated bisphenol A: manufactured by Tokyo Chemical Industry Co., Ltd.), 2,6-di-tert-butyl- 0.037 parts of p-cresol, 130.1 parts of toluene (molecular sieve 3A (manufactured by Wako Pure Chemical Industries, Ltd.)), 130.1 parts, N, N-dimethylformamide (dehydrated) (Kanto Chemical Co., Ltd.) 11.4 parts and 0.171 part of dibutyltin dilaurate were charged, and the mixture was heated to reflux at 110 ° C. using an oil bath with stirring in a nitrogen stream to completely dissolve the compound (b-8). Subsequently, 23.34 parts of compound (a-1) was added dropwise over 30 minutes using a dropping funnel, and reacted at 110 ° C. for 6 hours after the completion of the dropping. After the reaction solution was cooled to about 50 ° C., 2.32 parts of 2-hydroxyethyl acrylate was added and stirred vigorously, and then 20.4 parts of 2-propanol was added and stirred vigorously. The mixture was allowed to cool to room temperature to obtain a compound (A2) solution (solid content: 24%).
As a result of measuring the molecular weight, the compound (A2) had a number average molecular weight of 23,400 and a molecular weight distribution of 1.48.

(Synthesis Example 3)
In a reaction vessel equipped with a stirrer, a thermometer and a reflux condenser, compound (b-7) (spiroglycol: manufactured by Tokyo Chemical Industry Co., Ltd.) 36.53 parts, 2,6-di-tert-butyl-p- Cresol 0.045 parts, toluene (Molecular Sieve 3A (made by Wako Pure Chemical Industries, Ltd.) 128.1 parts), N, N-dimethylformamide (dehydrated) (made by Kanto Chemical Co., Inc.) 40.4 parts and 0.205 parts of dibutyltin dilaurate were charged, and the mixture was heated and refluxed at 110 ° C. using an oil bath with stirring in a nitrogen stream to completely dissolve the compound (b-7). Subsequently, 28.01 parts of compound (a-1) was added dropwise over 30 minutes using a dropping funnel, and reacted at 110 ° C. for 8 hours after completion of the dropping. After cooling the reaction solution to about 50 ° C., 2.79 parts of 2-hydroxyethyl acrylate was added and stirred vigorously, followed by 22.6 parts of 2-propanol and vigorously stirred. The mixture was allowed to cool to room temperature to obtain a compound (A3) solution (solid content: 26%).
As a result of measuring the molecular weight, the compound (A3) had a number average molecular weight of 32,000 and a molecular weight distribution of 1.67.

(Synthesis Example 4)
In a reaction vessel equipped with a stirrer, a thermometer and a reflux condenser, 24.54 parts of compound (b-6) (tricyclodecane dimethanol: manufactured by Tokyo Chemical Industry Co., Ltd.), 2,6-di-tert-butyl -P-cresol 0.047 part, methyl isobutyl ketone (Molecular Sieve 3A (made by Wako Pure Chemical Industries, Ltd.) 123.8 parts, dibutyltin dilaurate 0.213 parts charged with nitrogen stream Under stirring, the mixture was heated to reflux at 120 ° C. using an oil bath to completely dissolve the compound (b-6). Subsequently, using a dropping funnel, 28.48 parts of compound (a-1) was added dropwise over 30 minutes, and after completion of the addition, the mixture was reacted at 120 ° C. for 4 hours to give N, N-dimethylformamide (dehydration) (Kanto Chemical ( 42.2 parts) (manufactured by Co., Ltd.) was added, stirred vigorously, and further reacted at 120 ° C. for 4 hours. After cooling the reaction solution to about 50 ° C., 2.91 parts of 2-hydroxyethyl acrylate was added and stirred vigorously, and then 20.2 parts of 2-propanol was added and stirred vigorously. The mixture was allowed to cool to room temperature to obtain a compound (A4) solution (solid content: 23%).
As a result of measuring the molecular weight, the compound (A4) had a number average molecular weight of 54,100 and a molecular weight distribution of 1.85.

(Synthesis Example 5)
In a reaction vessel equipped with a stirrer, a thermometer and a reflux condenser, 21.92 parts of compound (b-1), 0.056 parts of 2,6-di-tert-butyl-p-cresol, methyl isobutyl ketone (molecular sieve) 3A (manufactured by Wako Pure Chemical Industries, Ltd.) 150.2 parts and 0.256 parts dibutyltin dilaurate were charged and heated to reflux at 120 ° C. using an oil bath under nitrogen flow stirring. The compound (b-1) was completely dissolved. Subsequently, 35.01 parts of compound (a-1) was added dropwise over 30 minutes using a dropping funnel, and reacted at 120 ° C. for 4 hours after completion of the dropwise addition. N, N-dimethylformamide (dehydration) (Kanto Chemical ( 15.8 parts) (manufactured by Co., Ltd.) was added and stirred vigorously, and further reacted at 120 ° C. for 4 hours. After removing the oil bath and cooling the reaction solution to about 50 ° C., 2.56 parts of compound (c-1) (isophoronediamine: manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred vigorously. Vigorous stirring was continued for 1 hour with the remaining heat remaining, and then 3.48 parts of 2-hydroxyethyl acrylate was added and stirred vigorously, and 22.4 parts of 2-propanol was further added and stirred vigorously. It stood to cool to room temperature, and obtained the compound (A5) solution (solid content 25%).
As a result of measuring the molecular weight, the compound (A5) had a number average molecular weight of 27,200 and a molecular weight distribution of 1.58.

(Comparative Synthesis Example 1)
In a reaction vessel equipped with a stirrer, a thermometer and a reflux condenser, 86 parts of polyhexamethylene carbonate diol (average molecular weight 860) (manufactured by Sigma-Aldrich Japan), 1,4-cyclohexanedimethanol (Wako Pure Chemical Industries, Ltd.) Kogyo Co., Ltd.) 130 parts, 1.71 parts dibutyltin dilaurate were charged, 222 parts of compound (a-1) was added dropwise with stirring under a nitrogen stream, and 657 parts of propylene glycol monomethyl ether acetate was added after completion of the addition. Then, a polyurethane solution containing the compound (5-1) was obtained by reacting at 70 ° C. for 6 hours under a nitrogen stream. To 548 parts of the polyurethane solution containing the compound (5-1), 34.8 parts of 2-hydroxyethyl acrylate was added and reacted with stirring at 40 ° C. to obtain a compound (B1) solution (solid content 44%).
As a result of measuring the molecular weight, the compound (B1) had a number average molecular weight of 35,200 and a molecular weight distribution of 1.59.

(Comparative Synthesis Example 2)
A diamine diluent was prepared by mixing 25.6 parts of isophoronediamine and 51 parts of propylene glycol monomethyl ether acetate. 548 parts of a polyurethane solution containing the compound (5-1) obtained according to Comparative Synthesis Example 1 was kept warm at 40 ° C. with stirring, and the diluted solution was added dropwise over 1 hour. Stirring was continued for 30 minutes while maintaining the temperature at 40 ° C. even after completion of the dropwise addition, to obtain a polyurethaneurea solution containing the compound (5-3). To 594 parts of the polyurethaneurea solution containing the compound (5-3), 17.0 parts of 2-hydroxyethyl acrylate was added and reacted with stirring at 40 ° C. to obtain a compound (B2) solution (solid content: 41%). .
As a result of measuring the molecular weight, the compound (B2) had a number average molecular weight of 37,700 and a molecular weight distribution of 1.76.

[Example 1]
The following components were mixed to prepare a retardation film composition.
Compound (A): Compound (A1) solution 80 parts Leveling agent: Polyether-modified silicone oil SH8400
(Toray Dow Corning Co., Ltd.) 0.001 part

(Production of retardation film)
The prepared composition for retardation film was coated on a release film (thickness: 188 μm) made of polyethylene terephthalate with an applicator, and then dried at 100 ° C. for 15 minutes. The obtained film was peeled off from the release film to form a film. Next, the film was stretched 3.0 times using a temperature-controlled autograph stretching machine (Strograph T, manufactured by Toyo Seiki Seisakusho Co., Ltd.) to prepare a retardation film.

[Examples 2 to 5, Comparative Examples 1 and 2]
A retardation film was prepared in the same manner as in Example 1 except that the compound (A1) solution was replaced with the compound solution shown in the “urethane acrylate solution” column of Table 1 (mixed in the content shown in the “solution part” column). Produced.

[Comparative Example 3]
An unstretched film 1 was fabricated in exactly the same manner as the film fabricated in Example 4 except that the stretching step was not included.

  The following evaluation was performed about the produced retardation film and an unstretched film.

(Optical anisotropy)
About the obtained retardation film and the unstretched film, the direction where a refractive index becomes the maximum was calculated | required with the automatic birefringence meter (KOBRA-WR, Oji Scientific Instruments company make).
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), Refractive. The results are shown in Table 2 as Re (550).

(Wavelength dispersion)
About the obtained retardation film and unstretched film, using an automatic birefringence meter (KOBRA-WR, manufactured by Oji Scientific Instruments Co., Ltd.), the retardation value at 450 nm [Re (450)] and the retardation at 550 nm The value [Re (550)] and the phase difference value [Re (650)] at 650 nm are measured, and [Re (450)] / [Re (550)] and [Re (650)] / [Re (550) are measured. )] Was calculated to obtain wavelength dispersion. The results are shown in Table 2.
If Re (450) / Re (550) is 1.04 or less, it can be determined that uniform polarization conversion is possible in a wide wavelength range. Further, if it is less than 1, it shows reverse wavelength dispersion, so that it is possible to perform uniform polarization conversion without a phase difference shift in a wide wavelength range, and it can be judged to be good.
If [Re (650)] / [Re (550)] is 0.97 or more, it can be determined that uniform polarization conversion is possible in a wide wavelength range. Further, when it is 1 or more, the reverse wavelength dispersion is exhibited, so that it is possible to perform uniform polarization conversion without a phase difference shift in a wide wavelength range, and it can be determined that it is favorable.

(Photoelastic coefficient)
The obtained retardation film and unstretched film were cut into 150 mm × 600 mm, and using an automatic birefringence meter (KOBRA-WR, manufactured by Oji Scientific Instruments Co., Ltd.), a five-point tension in the range of 0N to 50N at room temperature. The in-plane retardation value (Re) when σ was changed was measured, and the photoelastic coefficient was obtained from the slope of the approximate straight line prepared according to the following formula. The results are shown in Table 2.
Δn _st = C · σ
[In the formula, Δn _st represents stress birefringence, σ represents tension, and C represents a photoelastic coefficient. ]
It can be judged that it is favorable in a photoelastic coefficient being 30 * 10 <^-12> Pa < ^{-1 >} or less.

(Glass-transition temperature)
The obtained retardation film and unstretched film are cut out to 4 mm × 50 mm, and the glass transition temperature Tg (° C.) of the film is measured by carrying out the tensile mode measurement of TMA-100 (manufactured by Seiko Electronics Industry Co., Ltd.). Asked. The results are shown in Table 2.
If the glass transition temperature is 60 ° C. or higher and 200 ° C. or lower, it can be determined that the glass transition temperature is good.

(Thickness)
The thickness of the obtained retardation film was measured using a thickness meter (trade name: DIGIMICRO MH-15M, manufactured by Sendai Nikon Corporation). The results are shown in Table 2.

Example 6
The following components were mixed to prepare a retardation film composition.
Compound (A): Compound (A1) solution 80 parts Compound (I): N-vinylcarbazole (manufactured by Sigma-Aldrich Japan) 7.5 parts Photopolymerization initiator: Irgacure 184 (manufactured by Ciba Japan) ) 0.2 parts Solvent: N, N-dimethylformamide 16 parts Leveling agent: Polyether-modified silicone oil SH8400
(Toray Dow Corning Co., Ltd.) 0.1 part

(Production of retardation film)
The prepared retardation film composition was coated on a release film (thickness: 188 μm) made of polyethylene terephthalate with an applicator, dried at 100 ° C. for 15 minutes, and then irradiated with UV (high pressure mercury lamp: 200 mJ / cm per Pass). ² : 365 nm), and the obtained film was peeled off from the release film to form a film. Next, the film was stretched 3.0 times using a temperature-controlled autograph stretching machine (manufactured by Toyo Seiki Seisakusho, Strograph T) to produce an optical film. Table 4 shows the optical properties of the retardation film.

[Examples 7 to 10, Comparative Examples 4 and 5]
The compound (A1) solution was replaced with the compound solution described in the “urethane acrylate solution” column of Table 3 (mixed in the content shown in the “solution part” column), and the amount of N-vinylcarbazole was changed to “NVC / A retardation film was produced in the same manner as in Example 6 except that the amount described in the “Part” column was used.

  The obtained retardation film was evaluated in the same manner as in Example 1. The results are shown in Table 4.

From the results shown in Table 2 and Table 4, in the retardation films of Examples 1 to 5 and Examples 6 to 10, the photoelastic coefficient shows a small value, and the retardation change caused by the stress generated in the retardation film by an external force. Was confirmed to be small.
Further, in the retardation films of Examples 6 to 10, the wavelength dispersion coefficient α shows a small value of less than 1, and the retardation value shows reverse wavelength dispersion, so that more uniform polarization conversion can be achieved in a wide wavelength range. It was confirmed that it was possible.

  According to the retardation film of the present invention, the photoelastic coefficient can be reduced.

Claims (19)

Reacting at least one diol compound (1) selected from the group consisting of compounds represented by formula (1A) and formula (1B) with a polyisocyanate compound (2) having an alicyclic hydrocarbon skeleton, Next, the structural unit derived from the compound (A) obtained by reacting the compound (3) having a functional group capable of reacting with an ethylenic double bond and an isocyanato group of the polyisocyanate compound (2) is stretched. A retardation film.

^{HO-L 1 -W 1 -L 2} -OH (1A)
^{HO-W 2 -L 3 -W 3} -OH (1B)

[In Formula (1A) and Formula (1B), W ¹ represents a divalent bridged ring hydrocarbon group or spiro hydrocarbon group having 8 to 12 carbon atoms, and the bridged ring hydrocarbon group and the spiro hydrocarbon group. —CH ₂ — contained in the hydrogen group may be substituted with —NH—, —O—, or —S—.
L ¹ and L ² each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a single bond, a divalent aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms.
W ² and W ³ each independently represent a C 5-7 divalent alicyclic hydrocarbon group which may be substituted with a C 1-3 alkyl group. ] The retardation film according to claim 1, wherein the compound represented by the formula (1A) is a compound represented by the formula (1A-1).

[In Formula (1A-1), A ¹ and A ² each independently represent —CH ₂ —, —NR ^a —, —O—, or —S—.
R ^a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
n ³ and ^{n 4} are each independently represents an integer of 1 to 3. ] The compound represented by the formula (1A) is the phase difference according to the formula (b-1) ~ formula (b-7) at least Tanedea selected from the group consisting of compounds represented by Ru請 Motomeko 1 the film.

The retardation film according to claim 1, wherein W ² and W ³ are both cyclohexanediyl groups. The retardation film according to claim 1, wherein L ³ is a single bond and one group selected from the group consisting of groups represented by formulas (1B-1) to (1B-5).

[In formula (1B-1) to formula (1B-5), * represents a bond. ] The compound represented by formula (1B) is at least one selected from the group consisting of a compound represented by formula (b-8) and a compound represented by formula (b-9). 6. The retardation film according to any one of 5 above.

The retardation film according to any one of claims 1 to 6 , wherein the polyisocyanate compound (2) is a compound having a cyclohexane ring. The phase difference according to any one of claims 1 to 7 , wherein the polyisocyanate compound (2) is at least one selected from the group consisting of compounds represented by formulas (a-1) to (a-3). the film.

The retardation film according to any one of claims 1 to 8 , wherein the compound (3) is at least one selected from the group consisting of an acrylate having a hydroxy group and a methacrylate having a hydroxy group. One or more diol compounds (1) selected from the group consisting of compounds represented by formula (1A) and formula (1B), a polyisocyanate compound (2) having an alicyclic hydrocarbon skeleton, a polyamine compound, And a structural unit derived from the compound (A) obtained by reacting the compound (3) having a functional group capable of reacting with an ethylenic double bond and an isocyanate group of the polyisocyanate compound (2). The retardation film according to claim 1, which is stretched . The retardation film according to claim 10, wherein the polyamine compound is a compound having an alicyclic hydrocarbon structure.   The number average molecular weight of the compound (A) is 5,000 or more and 500,000 or less, and the glass transition temperature of the compound (A) is 60 ° C or more and 200 ° C or less. Retardation film. The retardation film according to claim 1, further comprising a structural unit derived from the compound represented by formula (I).

[In Formula (I), R ¹ represents a hydrogen atom or a methyl group.
R ² represents a cyclic hydrocarbon group or have a substituent good 4 to 20 carbon atoms the heterocyclic group having 6 to 20 carbon atoms which may have a substituent. ]   The retardation film according to claim 13, wherein the compound represented by the formula (I) is N-vinylcarbazole. The retardation film according to claim 1, wherein a retardation value Re (ν) at a wavelength νnm of transmitted light that passes through the retardation film satisfies the following formula.
Re (450) <Re (550) <Re (650) Reacting at least one diol compound (1) selected from the group consisting of compounds represented by formula (1A) and formula (1B) with a polyisocyanate compound (2) having an alicyclic hydrocarbon skeleton, Subsequently, the compound (A) obtained by reacting the functional group capable of reacting with the isocyanate group of the polyisocyanate compound (2) and the compound (3) having an ethylenic double bond, and represented by the formula (I) A composition for a retardation film comprising at least one selected from the group consisting of a monomer containing a compound and a resin having a structural unit derived from a monomer containing a compound represented by formula (I).

^{HO-L 1 -W 1 -L 2} -OH (1A)
^{HO-W 2 -L 3 -W 3} -OH (1B)

[In Formula (1A) and Formula (1B), W ¹ represents a divalent bridged ring hydrocarbon group or spiro hydrocarbon group having 8 to 12 carbon atoms, and the bridged ring hydrocarbon group and the spiro hydrocarbon group. —CH ₂ — contained in the hydrogen group may be substituted with —NH—, —O—, or —S—.
L ¹ and L ² each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a single bond, a divalent aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 9 carbon atoms.
W ² and W ³ each independently represent a C 5-7 divalent alicyclic hydrocarbon group which may be substituted with a C 1-3 alkyl group. ]

[In Formula (I), R ¹ represents a hydrogen atom or a methyl group.
R ² represents a cyclic hydrocarbon group or have a substituent good 4 to 20 carbon atoms the heterocyclic group having 6 to 20 carbon atoms which may have a substituent. ]   The composition for retardation films according to claim 16, further comprising a polymerization initiator.   The composition for retardation films according to claim 16 or 17, further comprising a solvent.   The manufacturing method of the retardation film which casts the composition for retardation films in any one of Claims 16-18 to a support body, dries, and also extends | stretches.