JP2008274102A - Cycloolefin resin film, polarizing plate, optical compensation film, anti-reflection film, liquid crystal display, and method of manufacturing the cycloolefin resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cycloolefin film, which prevents roll fouling from occurring on a casting roll even if a molten film is formed using a touch roll, is suitable for a polarizing plate, an optical compensation film, an anti-reflection film, a liquid crystal display or the like, is excellent in light weathering resistance, and has a good surface property; and to provide a method of manufacturing the cycloolefin film. <P>SOLUTION: The cycloolefin resin film contains 0.05 to 3 mass% of at least one of ultraviolet absorbers with a molecular weight of 500 or more and is produced by a molten film forming method using the touch roll. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cycloolefin resin film, a polarizing plate, an optical compensation film, an antireflection film, a liquid crystal display device, and a method for producing a cycloolefin resin film.

Conventionally, it is known to melt-form a polyolefin resin by adding an ultraviolet absorber.
For example, Patent Document 1 discloses a resin comprising a cycloolefin resin containing 30% by weight or more of a repeating unit containing an alicyclic structure not having a norbornane structure, a phenolic antioxidant and a phosphorus antioxidant. A composition is disclosed. Furthermore, it is described that an ultraviolet absorber may be added to these resin compositions.
Patent Document 2 discloses that a cycloolefin resin, a molecular weight of 300 or more, a vapor pressure at a temperature of 20 ° C. is 1 × 10 ⁻⁸ Pa or less, and a 5% weight reduction temperature in a heat loss measurement is 200 ° C. or more. A benzotriazole-based UV absorber and a hindered amine light stabilizer having a molecular weight of 500 or more, a vapor pressure at a temperature of 20 ° C. of 1 × 10 ⁻⁶ Pa or less, and a 5% weight loss temperature in a measurement of loss on heating of 250 ° C. A resin composition is disclosed.

JP-A-11-217481 JP 2001-72839 A

However, as a result of intensive studies by the inventor, the melt film-forming methods described in Patent Documents 1 and 2 have a problem that the surface condition of the obtained film is deteriorated. In addition, there is a problem that roll contamination of the film forming apparatus occurs.
The present invention aims to solve the above-mentioned problems, and provides a cycloolefin resin film produced by a melt film-forming method, which is excellent in light weather resistance and has a good surface condition. The purpose is to do. Furthermore, it aims at reducing the roll dirt of the film forming apparatus of this film.

（式中、Ｒ¹およびＲ²はそれぞれ独立に水素原子、ハロゲン原子または炭素数１〜５のアルキル基を表し、Ｒ³、Ｒ⁴、Ｒ⁵およびＲ⁶はそれぞれ独立に水素原子、炭素数１〜１８の置換もしくは無置換のアルキル基、または炭素数６〜１８の置換もしくは無置換のアリール基を表す。）
（４）投影斜めスジが１０本／ｃｍ以下である、（１）〜（３）のいずれか１項に記載のシクロオレフィン樹脂フィルム。
（５）前記シクロオレフィン樹脂が、付加重合によって得られたものであることを特徴とする、（１）〜（４）のいずれか１項に記載のシクロオレフィン樹脂フィルム。
（６）偏光膜に、（１）〜（５）のいずれか１項に記載のシクロオレフィン樹脂フィルムを少なくとも１層積層したことを特徴とする偏光板。
（７）（１）〜（５）のいずれか１項に記載のシクロオレフィン樹脂フィルムを基材に用いたことを特徴とする光学補償フィルム。
（８）（１）〜（５）のいずれか１項に記載のシクロオレフィン樹脂フィルムを基材に用いたことを特徴とする反射防止フィルム。
（９）（１）〜（５）のいずれか１項に記載のシクロオレフィン樹脂フィルム、（６）に記載の偏光板、（７）の光学補償フィルム、および、（８）に記載の反射防止フィルムの少なくとも一つを用いたことを特徴とする液晶表示装置。
（１０）分子量が５００以上の紫外線吸収剤の少なくとも１種類を０．０５〜３質量％含有するシクロオレフィン樹脂組成物を、タッチロールを用いて融膜製膜法で作製することを特徴とする、シクロオレフィン樹脂フィルムの製造方法。
（１１）前記紫外線吸収剤が、下記一般式（ＨＵＶ−１）で表される化合物であることを特徴とする（１０）に記載のシクロオレフィン樹脂フィルムの製造方法。
一般式（ＨＵＶ−１）

（式中、Ｒ¹およびＲ²はそれぞれ独立に水素原子、ハロゲン原子または炭素数１〜５のアルキル基を表し、Ｒ³、Ｒ⁴、Ｒ⁵およびＲ⁶はそれぞれ独立に水素原子、炭素数１〜１８の置換もしくは無置換のアルキル基、または炭素数６〜１８の置換もしくは無置換のアリール基を表す。） Based on the above problems, as a result of intensive studies by the inventor, the film was formed using a touch roll, and a high molecular weight ultraviolet absorber was used to improve the light weather resistance and surface defects of the resulting film. It has been found that not only can the roll contamination of the film forming apparatus be improved. Specifically, it was achieved by the following means.
(1) A cycloolefin resin film produced by a melt film-forming method using a touch roll, containing 0.05 to 3% by mass of at least one ultraviolet absorber having a molecular weight of 500 or more.
(2) The cycloolefin resin film as described in (1), wherein the absorbance at a wavelength of 380 nm is 5% or less.
(3) The cycloolefin resin film according to (1) or (2), wherein the ultraviolet absorber is a compound represented by the following general formula (HUV-1).
General formula (HUV-1)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or carbon number. Represents a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.
(4) The cycloolefin resin film according to any one of (1) to (3), wherein a projected oblique line is 10 lines / cm or less.
(5) The cycloolefin resin film according to any one of (1) to (4), wherein the cycloolefin resin is obtained by addition polymerization.
(6) A polarizing plate, wherein at least one layer of the cycloolefin resin film according to any one of (1) to (5) is laminated on a polarizing film.
(7) An optical compensation film using the cycloolefin resin film according to any one of (1) to (5) as a base material.
(8) An antireflection film using the cycloolefin resin film according to any one of (1) to (5) as a base material.
(9) The cycloolefin resin film according to any one of (1) to (5), the polarizing plate according to (6), the optical compensation film according to (7), and the antireflection according to (8). A liquid crystal display device using at least one of films.
(10) A cycloolefin resin composition containing 0.05 to 3% by mass of at least one ultraviolet absorber having a molecular weight of 500 or more is prepared by a melt film forming method using a touch roll. The manufacturing method of a cycloolefin resin film.
(11) The method for producing a cycloolefin resin film as described in (10), wherein the ultraviolet absorber is a compound represented by the following general formula (HUV-1).
General formula (HUV-1)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or carbon number. Represents a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

According to the present invention, it is possible to obtain a cycloolefin resin film produced by a melt film-forming method, which has excellent light weather resistance and good surface condition. Furthermore, it became possible to reduce the roll dirt of the film forming apparatus.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value. In the present specification, a “group” such as an alkyl group may or may not have a substituent unless otherwise specified. Further, in the case of a group having a limited number of carbons, the number of carbons means a number including the number of carbons that the substituent has.

Hereinafter, the present invention will be described in more detail.
《Cycloolefin resin》
First, the cycloolefin resin used for the cycloolefin resin film of this invention is demonstrated.
The cycloolefin resin in the present invention is not particularly defined as long as it does not depart from the gist of the present invention. For example, those described below can be adopted.

(Cycloolefin resin-A / ring-opening polymerization type)
As the cycloolefin resin-A used in the present invention, for example, (1) a ring-opening (co) polymer of a norbornene monomer is subjected to polymer modification such as maleic acid addition or cyclopentadiene addition as necessary. , Hydrogenated resins, (2) resins obtained by addition polymerization of norbornene monomers, and (3) resins obtained by addition copolymerization with norbornene monomers and olefin monomers such as ethylene and α-olefin. it can. The polymerization method and the hydrogenation method can be performed by conventional methods.

  Examples of the norbornene-based monomer include norbornene and alkyl and / or alkylidene substituted products thereof such as 5-methyl-2-norbornene, 5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, and 5-butyl. 2-norbornene, 5-ethylidene-2-norbornene and the like, and polar group substitution products thereof such as halogen; dicyclopentadiene, 2,3-dihydrodicyclopentadiene, etc .; dimethanooctahydronaphthalene, its alkyl and / or Or an alkylidene-substituted product and a polar group-substituted product such as halogen, for example, 6-methyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-ethyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8, a-octahydronaphthalene, 6-ethylidene-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-chloro-1,4: 5 8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-cyano-1,4: 5,8-dimethano-1,4,4a, 5,6,7, 8,8a-octahydronaphthalene, 6-pyridyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-methoxycarbonyl-1,4 : 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, etc .; adducts of cyclopentadiene and tetrahydroindene, etc .; 3-tetramers of cyclopentadiene, for example, 4,9: 5,8-dimethano-3a, , 4a, 5,8,8a, 9,9a-octahydro-1H-benzoindene, 4,11: 5,10: 6,9-trimethano-3a, 4,4a, 5,5a, 6,9,9a, 10, 10a, 11, 11a-dodecahydro-1H-cyclopentanthracene; and the like.

(Cycloolefin resin-B / ring-opening polymerization type)
Moreover, as cycloolefin resin, the cycloolefin resin represented by following General formula (1)-(4) can be mentioned, Among these, what is represented by the following general formula (1) is especially preferable.

〔一般式（１）〜（４）中、Ａ、Ｂ、ＣおよびＤは、それぞれ、水素原子または１価の有機基を示し、これらのうち少なくとも１つは極性基である。〕

[In General Formulas (1) to (4), A, B, C and D each represent a hydrogen atom or a monovalent organic group, and at least one of them is a polar group. ]

Here, examples of the monovalent organic group include an alkyloxycarbonyl-substituted alkyl group, and — (CH ₂ ) _n COOR (where R is a hydrocarbon group having 1 to 20 carbon atoms, and n is 0 to 10). Is preferred).

  As the cycloolefin resin in the present invention, at least one tetracyclododecene derivative represented by the following general formula (5) can be used alone or as a copolymer with the tetracyclododecene derivative. A hydrogenated polymer obtained by hydrogenating a polymer obtained by metathesis polymerization with an unsaturated cyclic compound may be used.

（一般式（５）中、Ａ、Ｂ、ＣおよびＤは、それぞれ、水素原子または１価の有機基を示し、これらのうち少なくとも１つは極性基である。）

(In general formula (5), A, B, C and D each represent a hydrogen atom or a monovalent organic group, and at least one of them is a polar group.)

In the tetracyclododecene derivative represented by the general formula (5), examples of the organic group include the organic groups described in the general formulas (1) to (4). Furthermore, when at least one of A, B, C and D is a polar group, a polarizing film excellent in adhesion to other materials, heat resistance and the like can be obtained. Furthermore, the polar group is a group represented by — (CH ₂ ) _n COOR (where R is a hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 0 to 10). Since the finally obtained hydrogenated polymer (cycloolefin resin film) has a high glass transition temperature, it is preferable. In particular, the polar substituent represented by — (CH ₂ ) _n COOR is preferably contained in one molecule of the tetracyclododecene derivative of the general formula (5) from the viewpoint of reducing the water absorption rate. In the polar substituent, it is preferable in that the hygroscopicity of the obtained hydrogenated polymer decreases as the number of carbon atoms of the hydrocarbon group represented by R increases, but the balance with the glass transition temperature of the obtained hydrogenated polymer. From the above point, the hydrocarbon group is preferably a chain alkyl group having 1 to 4 carbon atoms or a (poly) cyclic alkyl group having 5 or more carbon atoms, particularly a methyl group, an ethyl group, or a cyclohexyl group. Preferably there is.

Further, the tetracyclododecene derivative of the general formula (5) in which a hydrocarbon group having 1 to 10 carbon atoms is bonded as a substituent to a carbon atom to which a group represented by — (CH ₂ ) _n COOR is bonded is Since the resulting hydrogenated polymer has low hygroscopicity, it is preferable. In particular, the tetracyclododecene derivative of the general formula (5) in which the substituent is a methyl group or an ethyl group is preferable in terms of easy synthesis. Specifically, 8-methyl-8-methoxycarbonyltetracyclo [4,4,0,12.5,17.10] dodec-3-ene is preferable. These tetracyclododecene derivatives and mixtures of unsaturated cyclic compounds copolymerizable therewith are disclosed, for example, in JP-A-4-77520, page 4, upper right column, line 12 to page 6, lower right column, line 6. Metathesis polymerization and hydrogenation can be carried out by the methods described.

As the cycloolefin resin in the present invention, a cycloolefin resin (addition polymerization type) having the following structure can be used.
[A-1]: hydrogenated product of random copolymer of α-olefin having 2 to 20 carbon atoms and cyclic olefin represented by general formula (6),
[A-2]: hydrogenated product of ring-opening polymer or copolymer of cyclic olefin represented by the following general formula (6)

一般式（６）中、ｎは０または１であり、ｍは０または１以上の整数であり、ｑは０または１である。
なお、ｑが１の場合には、Ｒ^aおよびＲ^bは、それぞれ、下記に示す原子または炭化水素基であり、ｑが０の場合には、それぞれの結合手が結合して５員環を形成する。 General formula (6)

In general formula (6), n is 0 or 1, m is 0 or an integer of 1 or more, and q is 0 or 1.
When q is 1, each of R ^a and R ^b is an atom or a hydrocarbon group shown below. When q is 0, each bond is bonded to form a 5-membered ring. Form.

で示されるビシクロ［２．２．１］−２−ヘプテン（＝ノルボルネン）（上記式において、１〜７の数字は炭素の位置番号を示す。）および該化合物に炭化水素基が置換した誘導体が挙げられる。 R ^{1 to} R ¹⁸ and R ^a and R ^b are each a hydrogen atom, a halogen atom or a hydrocarbon group. Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the hydrocarbon group include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon group. More specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, and an octadecyl group, and the cycloalkyl group includes a cyclohexyl group. Group, and examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group. These hydrocarbon groups may be substituted with a halogen atom. Furthermore, in the above general formula (6), R ^{15 to} R ¹⁸ may be bonded to each other (in cooperation with each other) to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring thus formed The polycycle may have a double bond.
Specific examples of the cyclic olefin represented by the general formula (6) are shown below. As an example,

And bicyclo [2.2.1] -2-heptene (= norbornene) represented by the formula (wherein the numbers 1 to 7 represent carbon position numbers) and a derivative in which a hydrocarbon group is substituted on the compound. Can be mentioned.

As this substituted hydrocarbon group, 5-methyl group, 5,6-dimethyl group, 1-methyl group, 5-ethyl group, 5-n-butyl group, 5-isobutyl group, 7-methyl group, 5-phenyl group , 5-methyl-5-phenyl group, 5-benzyl group, 5-tolyl group, 5- (ethylphenyl) group, 5- (isopropylphenyl) group, 5- (biphenyl) group, 5- (β-naphthyl) Examples thereof include a group, a 5- (α-naphthyl) group, a 5- (anthracenyl) group, and a 5,6-diphenyl group.

Still other derivatives include cyclopentadiene-acenaphthylene adduct, 1,4-methano-1,4,4a, 9a-tetrahydrofluorene, 1,4-methano-1,4,4a, 5,10,10a-hexahydro. Bicyclo [2.2.1] -2-heptene derivatives such as anthracene can be exemplified.

で示されるテトラシクロ［４．４．０．１^2,5．１^7,10］−３−ドデセン、およびこれに炭化水素基が置換した誘導体が挙げられる。 In addition, tricyclo [4.3.0.1 ^2,5 ] -3-decene, 2-methyltricyclo [4.3.0.1 ^2,5 ] -3-decene, 5-methyltricyclo [4 .3.0.1 ^2,5 ] -3-decene and other tricyclo [4.3.0.1 ^2,5 ] -3-decene derivatives, tricyclo [4.4.0.1 ^2,5 ] -3 A tricyclo [4.4.0.1 ^2,5 ] -3-undecene derivative such as undecene, 10-methyltricyclo [4.4.0.1 ^2,5 ] -3-undecene,

Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, and derivatives substituted with a hydrocarbon group.

As the hydrocarbon group, 8-methyl group, 8-ethyl group, 8-propyl group, 8-butyl group, 8-isobutyl group, 8-hexyl group, 8-cyclohexyl group, 8-stearyl group, 5,10- Dimethyl group, 2,10-dimethyl group, 8,9-dimethyl group, 8-ethyl-9-methyl group, 11,12-dimethyl group, 2,7,9-trimethyl group, 2,7-dimethyl-9- Ethyl group, 9-isobutyl-2,7-dimethyl group, 9,11,12-trimethyl group, 9-ethyl-11,12-dimethyl group, 9-isobutyl-11,12-dimethyl group, 5,8,9 , 10-tetramethyl group, 8-ethylidene group, 8-ethylidene-9-methyl group, 8-ethylidene-9-ethyl group, 8-ethylidene-9-isopropyl group, 8-ethylidene-9-butyl group, 8- n-propylidene 8-n-propylidene-9-methyl group, 8-n-propylidene-9-ethyl group, 8-n-propylidene-9-isopropyl group, 8-n-propylidene-9-butyl group, 8-isopropylidene group 8-isopropylidene-9-methyl group, 8-isopropylidene-9-ethyl group, 8-isopropylidene-9-isopropyl group, 8-isopropylidene-9-butyl group, 8-chloro group, 8-bromo group , 8-fluoro group, 8,9-dichloro, 8-phenyl group, 8-methyl-8-phenyl group, 8-benzyl group, 8-tolyl group, 8- (ethylphenyl) group, 8- (isopropylphenyl) Group, 8,9-diphenyl group, 8- (biphenyl) group, 8- (β-naphthyl) group, 8- (α-naphthyl) group, 8- (anthracenyl) group, 5,6-diphenyl group, etc. Rukoto can.

Furthermore, tetracyclo [4.4.0.1 ^2,5 ... Adducts of (cyclopentadiene-acenaphthylene adduct) and cyclopentadiene. 1 ^7,10 ] -3-dodecene derivative, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13] -4-pentadecene and its derivatives, pentacyclo [7.4.0.1 ^2,5. 1 ^9,12 . 0 ^8,13] -3-pentadecene and its derivatives, pentacyclo [8.4.0.1 ^2,5. 1 ^9,12 . 0 ^8,13] -3-hexadecene and derivatives thereof, pentacyclo [6.6.1.1 ^{3, 6.} 0 ^2,7 . 0 ^9,14] -4-hexadecene and derivatives thereof, hexacyclo [6.6.1.1 ^{3, 6.} 1 ^10,13 . 0 ^2,7 . 0 ^9,14] -4-heptadecene and its derivatives, heptacyclo [8.7.0.1 ^2,9. 1 ^4,7 . 1 ^11,17 . 0 ^3,8 . 0 ^12,16 ] -5-eicosene and its derivatives, heptacyclo [8.7.0.1 ^3,6 . 1 ^10,17 . 1 ^12,15 . 0 ^2,7 . 0 ^11,16 ] -4-eicosene and its derivatives, heptacyclo [8.8.0.1 ^2,9 . 1 ^4,7 . 1 ^11,18 . 0 ^3,8 . 0 ^12,17 ] -5- ^heneicosene and its derivatives, octacyclo [8.8.0.1 ^2,9 . 1 ^4,7 . 1 ^11,18 . 1 ^13,16 . 0 ^3,8 . 0 ^12,17 ] -5-docosene and derivatives thereof, nonacyclo [10.9.1.1 ^4,7 . 1 ^13,20 . 1 ^15,18 . 0 ^2,10 . 0 ^3,8 . 0 ^12,21 . 0 ^14,19] -5-pentacosene and derivatives thereof.

Specific examples of these cycloolefin resins are as described above, but more specific structures of these compounds are shown in paragraphs [0032] to [0054] of JP-A-7-145213. Yes.
Moreover, about the synthesis method of these cycloolefin resin, it can carry out with reference to paragraph number [0039]-[0068] of Unexamined-Japanese-Patent No. 2001-114836.

The following can also be used as the cycloolefin resin (addition polymerization type) of the present invention.
A cycloolefin (co) polymer having a polymer unit derived from a compound represented by the following formula (I), (II), (II ′), (III), (IV), (V) or (VI) is also preferred.

式中、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹およびＲ¹²は、それぞれ、水素原子、または、炭素数１〜８のアルキル基、炭素数６〜１８のアリール基等の直鎖または分岐の、飽和または不飽和の、炭素数１〜２０の炭化水素基である。 In the above formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, and the number of carbon atoms C6-C20 hydrocarbon group such as 6-18 aryl group, C7-20 alkylene aryl group, C2-C20 alkenyl group which may be cyclic, saturated, unsaturated or aromatic To form a cyclic group. n is an integer of 0-5.

In the formula, each of R ⁹ , R ¹⁰ , R ^11, and R ¹² is a hydrogen atom, or a linear or branched, saturated or saturated group such as an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 18 carbon atoms. An unsaturated hydrocarbon group having 1 to 20 carbon atoms.

  The cycloolefin (co) polymer is obtained, for example, by ring-opening polymerization of at least one of the compounds represented by the formulas (I) to (VI), and then hydrogenating the obtained product. be able to.

式中、ｎは２〜１０の数である。 Moreover, the cycloolefin (co) polymer which contains the polymer unit derived from the compound represented by a following formula (VIII) in the said polymer 0-45 mol% of the whole is also preferable.

In the formula, n is a number of 2 to 10.

  The proportion of polymerized units derived from cyclic, especially polycyclic olefins, is preferably 3 to 75 mol% of the cycloolefin (co) polymer. The proportion of the polymer units derived from the acyclic olefin is preferably 5 to 80 mol% of the cycloolefin (co) polymer.

  The cycloolefin (co) polymer is preferably one or more polycyclic olefins, in particular polymerized units derived from a compound of formula (I) or a compound of formula (III), and It consists of polymerized units derived from compounds of the formula (VII), in particular α-olefins having 2 to 20 carbon atoms. Preferably, a cyclohexane comprising a polymer unit derived from a compound represented by formula (I) or a compound represented by formula (III) and a polymer unit derived from a compound represented by formula (VII) is preferred. Olefin copolymer. More preferably, it contains a polymer unit derived from a compound represented by formula (I) or formula (III), a polymer unit derived from a compound represented by formula (VII), and at least two double bonds Cyclic or acyclic olefins (polyenes), for example, especially cyclic, preferably polycyclic dienes such as norbornadiene, particularly preferably, for example, vinyl norbornene carrying an alkenyl group having 2 to 20 carbon atoms It is a three-dimensional polymer composed of polymer units derived from polycyclic alkenes.

  The cycloolefin resin used in the present invention preferably contains an olefin based on a norbornene structure, particularly preferably norbornene, tetracyclododecene, and optionally vinyl norbornene or norbornadiene. Also preferred are cycloolefins (copolymers) comprising polymerized units derived from α-olefins having for example 2 to 20 carbon atoms, particularly preferably acyclic olefins having terminal double bonds such as ethylene or propylene. ) Polymer. Particularly preferred are norbornene / ethylene copolymers and tetracyclododecene / ethylene copolymers.

  Among the three-dimensional polymers, three-dimensional polymers of norbornene / vinyl norbornene / ethylene, norbornene / norbornadiene / ethylene terpolymer, tetracyclododecene / vinylnorbornene / ethylene terpolymer, and tetracyclododecene / vinyl are particularly preferable. Tetracyclododecene-ethylene three-dimensional polymer. The proportion of polymerized units derived from polyenes, preferably vinyl norbornene or norbornadiene, is 0.1 to 50 mol%, particularly preferably 0.1 to 20 mol%, based on the total structure of the cycloolefin resin, The proportion of the acyclic monoolefin represented by (VII) is usually 0 to 99 mol%, preferably 5 to 80 mol%. In the said three-dimensional polymer, Preferably it is 0.1-99 mol% of a cycloolefin (co) polymer, More preferably, it is 3-75 mol%.

The cycloolefin resin used in the present invention preferably contains at least a polymer unit that can be derived from the compound represented by formula (I) and a polymer unit that can be derived from the compound represented by formula (VII). Contains one type of cycloolefin (co) polymer.
Such cycloolefin (co) polymer can be synthesized according to paragraph numbers 0019 to 0020 of JP-A-10-168201.

As the cycloolefin resin in the present invention, JP-A-60-168708, JP-A-62-252406, JP-A-62-2252407, JP-A-2-133413, JP-A-63. Resins described in JP-A-145324, JP-A-63-264626, JP-A-1-240517, and JP-B-57-8815 can be employed.
In the present invention, it is particularly preferable to employ those obtained by addition polymerization of norbornene monomers.

The cycloolefin resin in the present invention preferably has a glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of 70 ° C. or higher, more preferably 70 to 250 ° C., still more preferably 110 It is -180 degreeC and 120-180 degreeC is especially preferable.

As a weight average molecular weight of the cycloolefin resin in this invention, 5,000-1,000,000 are preferable, More preferably, it is 8,000-200,000.
The cycloolefin resin in the present invention preferably has a saturated water absorption of 1% by mass or less, more preferably 0.8% by mass or less. For example, the glass transition temperature (Tg) and saturated water absorption of the cycloolefin resins represented by the general formulas (1) to (4) are controlled by selecting the type of the substituents A, B, C, and D. be able to.

  The cycloolefin resin in the present invention preferably has an intrinsic viscosity (ηinh) measured at 30 ° C. in chloroform of 0.1 to 1.5 dl / g, more preferably 0.4 to 1.2 dl / g. g. Moreover, it is preferable that intrinsic viscosity [(eta)] measured in 135 degreeC decalin is 0.01-20 dl / g normally, More preferably, it is 0.03-10 dl / g, More preferably, 0.05- The melt flow index (MFR) measured at 260 ° C. under a load of 2.16 kg according to ASTM D1238 is preferably 0.1 to 200 g / 10 min, more preferably 1 to 100 g / 10 min. More preferably, it is 5 to 50 g / 10 minutes.

  Furthermore, the softening point of the cycloolefin resin in the present invention is preferably 30 ° C. or higher, preferably 70 ° C. or higher, more preferably 80 to 260 ° C. as the softening point measured with a thermal mechanical analyzer (TMA). .

In the cycloolefin resin of the present invention, the hydrogenation rate of the hydrogenated polymer is preferably 50% or more, more preferably 90% or more, and further preferably 60 MHz or more as measured by ¹ H-NMR. Is 98% or more. The higher the hydrogenation rate, the more the resulting cycloolefin resin film is more stable against heat and light. Moreover, it is preferable that gel content contained in this hydrogenated polymer is 5 mass% or less, More preferably, it is 1 mass% or less.

The cycloolefin resin in the present invention is preferably amorphous or low crystalline, and the crystallinity measured by X-ray diffraction method is preferably 20% or less, more preferably 10% or less, More preferably, it is 2% or less.

<Ultraviolet absorber>
Next, it describes about the ultraviolet absorber which is preferably added to cycloolefin resin in this invention and is represented by general formula (HUV-1) and whose molecular weight is 500 or more.

（式中、Ｒ¹およびＲ²はそれぞれ独立に水素原子、ハロゲン原子または炭素数１〜５のアルキル基を表し、Ｒ³、Ｒ⁴、Ｒ⁵およびＲ⁶はそれぞれ独立に水素原子、炭素数１〜１８の置換もしくは無置換のアルキル基、または炭素数６〜１８の置換もしくは無置換のアリール基を表す。）

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or carbon number. Represents a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

R ¹ and R ² are preferably a hydrogen atom or a chlorine atom.
R ³ , R ⁴ , R ⁵ and R ⁶ are preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. More preferably, a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, tert-pentyl group, hexyl group, heptyl group, octyl group, Isooctyl group, tert-octyl group, nonyl group, isononyl group, tert-nonyl group, decyl group, isodecyl group, dodecyl group, isododecyl group, tert-dodecyl group, tert-tridecyl group, isotridecyl group, tetradecyl group, hexadecyl group, Octadecyl group, and also phenyl group, methylphenyl group, ethylphenyl group, propylphenyl group, isopropylphenyl group, butylphenyl group, isobutylphenyl group, tert-butylphenyl group, pentylphenyl group, isopentylphenyl group, tert -Pentylphenyl group, hexyl fe Group, isohexylphenyl group, cyclohexylphenyl group, heptylphenyl group, methylcyclohexylphenyl group, octylphenyl group, tert-octylphenyl group, 2-ethylhexylphenyl group, nonylphenyl group, isononylphenyl group, decylphenyl group, Isodecylphenyl group, dodecylphenyl group, isododecylphenyl group, tert-dodecylphenyl group, tridecylphenyl group, naphthyl group, methylnaphthyl group, dimethylphenyl group, diethylphenyl group, dipropylphenyl group, diisopropyl Phenyl group, dibutylphenyl group, diisobutylphenyl group, di-tert-butylphenyl group, dipentylphenyl group, diisopentylphenyl group, di-tert-pentylphenyl group, dihexylphenyl group, diisohexyl Phenyl group, dicyclohexylphenyl group, diheptylphenyl group, dimethylcyclohexylphenyl group, dioctylphenyl group, di-tert-octylphenyl group, di-2-ethylhexylphenyl group, dinonylphenyl group, diisononylphenyl group, didecyl Phenyl group, diisodecylphenyl group, didodecylphenyl group, diisododecylphenyl group, di-tert-dodecylphenyl group, ditridecylphenyl group, diisopropylnaphthyl group, triisopropylnaphthyl group, dibutylnaphthyl group, diisobutylnaphthyl group, di- a tert-butylnaphthyl group, a triisobutylnaphthyl group, a tri-tert-butylnaphthyl group, a dipentylnaphthyl group, a di-tert-pentylnaphthyl group, a tripentylnaphthyl group, and a tri-tert-pentylnaphthyl group.

R ³ , R ⁴ , R ⁵ and R ⁶ are more preferably a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, tert -Pentyl, hexyl, heptyl, octyl, isooctyl, tert-octyl, nonyl, isononyl, tert-nonyl, isodecyl, dodecyl, isododecyl, tert-dodecyl, tert-tridecyl , Phenyl group, methylphenyl group, isopropylphenyl group, isobutylphenyl group, tert-butylphenyl group, isopentylphenyl group, tert-pentylphenyl group, cyclohexylphenyl group, octylphenyl group, tert-octylphenyl group, isononylphenyl group Group, isodecylphenyl group, naphthyl group, dimethylphenyl group, dii Propylphenyl group, diisobutylphenyl group, di-tert-butylphenyl group, di-tert-pentylphenyl group, di-tert-octylphenyl group, di-tert-dodecylphenyl group, diisopropylnaphthyl group, triisopropylnaphthyl group, diisobutyl A naphthyl group, a di-tert-butylnaphthyl group, a triisobutylnaphthyl group, a tri-tert-butylnaphthyl group, a di-tert-pentylnaphthyl group, and a tri-tert-pentylnaphthyl group.

R ³ , R ⁴ , R ⁵ and R ⁶ are particularly preferably a hydrogen atom, methyl group, propyl group, isopropyl group, isobutyl group, tert-butyl group, isopentyl group, tert-pentyl group, isooctyl group, tert- Octyl, isononyl, tert-nonyl, tert-tridecyl, isodecyl, isododecyl, phenyl, methylphenyl, isopropylphenyl, tert-butylphenyl, tert-pentylphenyl, naphthyl, diisopropylphenyl Group, diisobutylphenyl group, di-tert-butylphenyl group, di-tert-pentylphenyl group, di-tert-octylphenyl group, diisopropylnaphthyl group, triisopropylnaphthyl group, diisobutylnaphthyl group, di-tert-butylnaphthyl group , Triisobutyl naphthyl group, tri-tert-butyl naphthyl group, -tert- Penchirunafuchiru group, a tri -tert- Penchirunafuchiru group.

R ³ , R ⁴ , R ⁵ and R ⁶ are most preferably a hydrogen atom, a methyl group, a propyl group, an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a tert-pentyl group, an isooctyl group or a tert-octyl group. , Isononyl group, tert-nonyl group, isodecyl group, tert-tridecyl group, phenyl group, methylphenyl group, isopropylphenyl group, tert-butylphenyl group, tert-pentylphenyl group, diisopropylphenyl group, diisobutylphenyl group, di- a tert-butylphenyl group and a di-tert-pentylphenyl group; Further recommended R ³ and R ⁴ are a hydrogen atom, a tert-butyl group, a tert-pentyl group, a tert-octyl group, a tert-nonyl group, and a tert-tridecyl group, and further recommended R ⁵ and R ⁶ is a hydrogen atom, a methyl group, or a phenyl group. Some of these ultraviolet absorbers are described in JP-A No. 61-118373.

Although the specific example of the ultraviolet absorber which is represented with general formula (HUV-1) and the molecular weight is 500 or more is described below, the ultraviolet absorber which can be used by this invention is not limited to these. . In all of the following specific examples, the molecular weight is 500 or more, and the mass loss when heated at 240 ° C. for 60 minutes in nitrogen is 10% by mass or less.
UVV-1: R ¹ = R ² = hydrogen atom, R ³ = R ⁴ = tert-octyl group, R ⁵ = R ⁶ = hydrogen atom UVV-2: R ¹ = R ² = chlorine atom, R ³ = R ⁴ = tert-octyl group, R ⁵ = R ⁶ = hydrogen atom ^{UVV-3: R 1 = R} 2 = hydrogen atom, R ³ = R ⁴ = tert- octyl group, R ⁵ = methyl, R ⁶ = hydrogen

UVV-4: R ¹ = R ² = hydrogen atom, R ³ = R ⁴ = tert-octyl group, R ⁵ = phenyl group, R ⁶ = hydrogen atom UVV-5: R ¹ = R ² = hydrogen atom, R ³ = R ⁴ = tert-pentyl group, R ⁵ = R ⁶ = hydrogen atom UVV-6: R ¹ = R ² = chlorine atom, R ³ = R ⁴ = tert-pentyl group, R ⁵ = R ⁶ = hydrogen atom UVV -7: R ¹ = R ² = hydrogen atom, R ³ = R ⁴ = tert-octyl group, R ⁵ = R ⁶ = methyl group UVV-8: R ¹ = R ² = chlorine atom, R ³ = R ⁴ = tert- nonyl group, R ⁵ = R ⁶ = hydrogen atom ^{UVV-9: R 1 = R} 2 = hydrogen atom, R ³ = R ⁴ = tert- tridecyl group, R ⁵ = R ⁶ = hydrogen atom UVV-10: R ¹ = chlorine atom, R ² = hydrogen atom, R ³ = R ⁴ = tert-octyl group, R ⁵ = phenyl group, R ⁶ = hydrogen atom UVV-11: R ¹ = chlorine atom, R ² = hydrogen atom, R ³ tert- butyl group, R ⁴ = tert- octyl group, R ⁵ = phenyl, R ⁶ = hydrogen atom particular UVV-1 is commercially available as Adeka Stab LA-31 (Asahi Denka Kogyo).
In this invention, it is preferable to contain a ultraviolet absorber in the ratio of 0.05-3 mass% with respect to cycloolefin resin, and to add in the ratio of 0.1-2.5 mass%, 0.3- It is more preferable to add at a ratio of 2.0% by mass.

<Stabilizer>
In the present invention, it is particularly effective to add a stabilizer in order to maintain the stability of the cycloolefin resin during high-temperature melt film formation. Preferable stabilizers include a phenol stabilizer having a molecular weight of 500 or more, a phosphite stabilizer having a molecular weight of 500 or more, a thioether stabilizer having a molecular weight of 500 or more, and a hydroxyphenyl group and a phosphite group. Mention may be made of one or more stabilizers selected from the group consisting of stabilizers having a molecular weight of 500 or more. In particular, a phenolic stabilizer having a molecular weight of 500 or more is used in combination with a stabilizer selected from the group consisting of a phosphite stabilizer having a molecular weight of 500 or more and a thioether stabilizer having a molecular weight of 500 or more. It is preferable. It is also preferable to use a stabilizer having a hydroxyphenyl group and a phosphite group and having a molecular weight of 500 or more.

(Phenolic stabilizer)
Phenol stabilizers are readily available as commercial products and are sold by the following manufacturers. From Ciba Specialty Chemicals, Irganox 1076, Irganox 1010, Irganox 3113, Irganox 245, Irganox 1135, Irganox 1330, Irganox 259, Irganox 565, Irganx 565, Irganx 565, Ir35x1025 Moreover, it can obtain from Asahi Denka Kogyo Co., Ltd. as ADK STAB AO-50, ADK STAB AO-20, ADK STAB AO-70, and ADK STAB AO-80. Furthermore, it can be obtained from Sumitomo Chemical Co., Ltd. as Sumilizer BP-76, Sumilizer BP-101, and Sumilizer GA-80. Moreover, it can obtain from Sipro Kasei Co., Ltd. as Cynox 326M and Cynox 336B.

(Phosphite stabilizer)
As phosphite stabilizers having an antioxidant effect and having a molecular weight of 500 or more, compounds described in [0023] to [0039] of JP-A No. 2004-182979, JP-A No. 51-70316, JP-A No. Hei. Examples thereof include compounds described in JP-A-10-306175, JP-A-57-78431, JP-A-54-157159, and JP-A-55-13765. These are commercially available from Asahi Denka Kogyo Co., Ltd. as Adeka Tab 1178, 2112, PEP-8, PEP-24G, PEP-36G, HP-10, and Sandostab P-EPQ from Clariant. Is possible.

(Thioether stabilizer)
As the thioether stabilizer, any known thioether stabilizer can be used. For example, it is marketed by Sumitomo Chemical Co., Ltd. as Sumilizer TPL, TPM, TPS, TDP. It is also available from Asahi Denka Kogyo Co., Ltd. as ADK STAB AO-412S.

(Stabilizer having hydroxyphenyl group and phosphite group)
Examples of the stabilizer having a molecular weight of 500 or more having a hydroxyphenyl group and a phosphite group in the same molecule include those described in JP-A-10-273494. As a commercially available product, Sumilizer GP (Sumitomo Chemical Co., Ltd.) can be mentioned.

(Use of stabilizer)
When using the stabilizer, at least one phenol-based stabilizer and at least one selected from a phosphite-based stabilizer or a thioether-based stabilizer are contained in an amount of 0.02 to 3% by mass, respectively, based on the cycloolefin resin. It is preferable to make it contain, and it is to make it contain 0.05-1 mass% especially. The ratio of the phenol stabilizer to at least one selected from a phosphite stabilizer or a thioether stabilizer is preferably 1/10 to 10/1 (parts by mass). Examples of preferred combinations include ADK STAB AO-60 / ADK STAB PEP-36G (1/1 mass ratio).

(Other stabilizers)
Further, a long-chain aliphatic amine described in JP-A-61-63686, a compound containing a sterically hindered amine group described in JP-A-6-329830, and a hindered dye described in JP-A-7-90270. Peridinyl light stabilizers, organic amines described in JP-A-7-278164, and the like can also be used. Preferred amine stabilizers are ADK STAB LA-57, LA-52, LA-67, LA-62, LA-77 from Asahi Denka, and TINUVIN 765, 144 from Ciba Specialty Chemicals. Commercially available. The ratio of amines to the stabilizer is usually about 0.01 to 25% by weight.

"Additive"
In the present invention, various additives may be further added to the cycloolefin resin as necessary. The addition may be performed at any stage from before the preparation of the melt to after the preparation. In the present invention, plasticizers, fine particles, optical adjusting agents, release agents, surfactants, thermal stabilizers, antistatic agents, flame retardants, lubricants, oils, and the like can be used as additives other than stabilizers.

(Plasticizer)
First, the plasticizer will be described. If a plasticizer is added to the cycloolefin resin, the crystal melting temperature (Tm) of the cycloolefin resin can be lowered. The molecular weight of the plasticizer used in the present invention is not particularly limited, but is preferably a high molecular weight, for example, preferably a molecular weight of 500 or more, more preferably 550 or more, and further preferably 600 or more. Examples of the plasticizer include phosphate esters, alkylphthalylalkyl glycolates, carboxylic acid esters, and fatty acid esters of polyhydric alcohols. These plasticizers may be solid or oily. That is, the melting point and boiling point are not particularly limited. When performing melt film formation, those having non-volatility can be particularly preferably used.

(Fine particles)
In the present invention, fine particles may be mixed in the cycloolefin resin. Examples of the fine particles include fine particles of inorganic compounds and fine particles of organic compounds, and any of them may be used. The average primary particle size of the cycloolefin resin fine particles in the present invention is preferably 5 nm to 3 μm, more preferably 5 nm to 2.5 μm, and more preferably 20 nm to 2.0 μm from the viewpoint of keeping the haze low. Is more preferable. Here, the average primary particle size of the fine particles is determined by observing the cycloolefin resin film with a transmission electron microscope (magnification of 500,000 to 1,000,000 times) and determining the average value of the primary particle sizes of 100 particles. The addition amount of the fine particles is preferably 0.005 to 1.0% by mass with respect to the cycloolefin resin, more preferably 0.01 to 0.8% by mass, and still more preferably 0.02 to 0%. 4% by mass.

  The average secondary particle size of the fine particles in the cycloolefin resin film finally obtained by the production method of the present invention is preferably 0.01 to 5 μm, more preferably 0.02 to 3 μm. It is preferably 0.02 to 1 μm. Here, the average secondary particle size of the fine particles is obtained by observing the cycloolefin resin film with a transmission electron microscope (magnification of 100,000 to 1,000,000 times) and obtaining the average value of the secondary particle sizes of 100 particles. decide.

Examples of the inorganic compound include SiO ₂ , ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , ZrO ₂ , In ₂ O ₃ , MgO, BaO, MoO ₂ , V ₂ O ₅ , talc, clay, calcined kaolin, and calcined. Examples thereof include calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate. Preferably, it is at least one of SiO ₂ , ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , ZrO ₂ , In ₂ O ₃ , MgO, BaO, MoO ₂ and V ₂ O ₅ , more preferably SiO _2. , TiO ₂ , SnO ₂ , Al ₂ O ₃ and ZrO ₂ .

As the fine particles of SiO ₂ , for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above, Nippon Aerosil Co., Ltd.) can be used. . As the ZrO ₂ fine particles, for example, commercially available products such as Aerosil R976 and R811 (above, manufactured by Nippon Aerosil Co., Ltd.) can be used. Seahoster KE-E10, E30, E40, E50, E50, E70, E150, W10, W30, W50, P10, P30, P50, P100, P150, P250 ) Etc. can also be used. Furthermore, silica microbeads P-400 and 700 (catalyst chemical industry product) can also be used. Also, SO-G1, SO-G2, SO-G3, SO-G4, SO-G5, SO-G6, SO-E1, SO-E2, SO-E3, SO-E4, SO-E5, SO-E6, SO-C1, SO-C2, SO-C3, SO-C4, SO-C5, SO-C6 (manufactured by Admatechs Co., Ltd.) can also be used. Further, silica particles 8050, 8070, 8100, and 8150 (Mortex Co., Ltd., powdered water dispersion) can also be used.

  Next, as the fine particles of the organic compound that can be used in the present invention, for example, polymers such as silicone resins, fluororesins, and acrylic resins are preferable, and silicone resins are particularly preferable. The silicone resin preferably has a three-dimensional network structure, such as Tospearl 103, 105, 108, 120, 145, 3120, and 240 (above, manufactured by Toshiba Silicone Co., Ltd.). Commercial products having a trade name can be used.

Further, it is preferable to use fine particles made of an inorganic compound that are surface-treated in order to stably exist in the cycloolefin resin film. As the surface treatment method, there are a chemical surface treatment method using a coupling agent and a physical surface treatment method such as plasma discharge treatment or corona discharge treatment. In the present invention, a coupling agent should be used. Is preferred. As the coupling agent, an organoalkoxy metal compound (for example, a silane coupling agent, a titanium coupling agent, etc.) is preferably used. When inorganic fine particles are used as the fine particles (especially when SiO ₂ is used), treatment with a silane coupling agent is particularly effective. An organosilane compound can be used as the silane coupling agent. Although the usage-amount of the said coupling agent is not specifically limited, Preferably it is recommended to use 0.005-5 mass% with respect to inorganic fine particles, and it is preferable to use 0.01-3 mass% further.

In the present invention, fine particle-containing master pellets having a higher concentration of stabilizer than the desired amount in the cycloolefin resin may be prepared in advance. This makes it possible to produce cycloolefin resin pellets with good dispersibility of fine particles, and it is possible to produce a cycloolefin resin film having excellent surface shape and surface slipperiness (prevention of creaking) with good handling properties.
At this time, it is necessary to prepare a cycloolefin resin master pellet (cycloolefin resin master pellet) that does not contain fine particles. In that case, it is preferable to contain the above-mentioned stabilizer in the fine particle-containing master pellet at the same time. The amount of fine particles added in the fine particle-containing master pellet is not particularly limited, but preferably 2 to 50 times the fine particle final concentration in the cycloolefin resin film, more preferably 2 to 30 times, and still more preferably. It is 3 to 25 times, particularly preferably 4 to 20 times. For mixing the cycloolefin resin master pellet and the fine particle-containing master pellet, the above-described mixer can be used. In addition, additives other than fine particles (stabilizers, plasticizers, other additives, etc.) may be added together at the stage of preparing the fine particle-containing master pellet. The final concentration of the desired additive in the cycloolefin resin film is preferably 2 to 50 times, more preferably 2 to 30 times, still more preferably 3 to 25 times, and particularly preferably 4 to 20 times. is there.

(Optical adjusting agent)
In the present invention, an optical adjusting agent (a retardation control agent, particularly a retardation increasing agent) for controlling optical anisotropy may be added to the cycloolefin resin. In the present invention, in order to adjust the retardation of the cycloolefin resin film, it is preferable to use an aromatic compound having at least one aromatic ring as a retardation control agent. An aromatic compound is normally used in 0.01-20 mass parts with respect to 100 mass parts of cycloolefin resin. The aromatic compound is preferably used in the range of 0.05 to 15 parts by mass, and more preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the cycloolefin resin. At this time, two or more kinds of aromatic compounds may be used in combination. The aromatic ring of the aromatic compound here includes an aromatic hetero ring in addition to the aromatic hydrocarbon ring. The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring). The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As a hetero atom contained in the heterocycle, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.

(Release agent)
The cycloolefin resin in the present invention preferably contains a compound having a fluorine atom. The compound having a fluorine atom can exhibit an action as a release agent, and may be a low molecular weight compound or a polymer. Examples of the polymer include the polymers described in JP-A No. 2001-269564. Preferred as the polymer having a fluorine atom is a polymer obtained by polymerizing a monomer containing an ethylenically unsaturated monomer containing a fluorinated alkyl group as an essential component. The fluorinated alkyl group-containing ethylenically unsaturated monomer related to the polymer is not particularly limited as long as it is a compound having an ethylenically unsaturated group and a fluorinated alkyl group in the molecule. A surfactant having a fluorine atom can also be used, and a nonionic surfactant is particularly preferable.

(mixture)
Ultraviolet absorbers, stabilizers, and various additives (herein, these are collectively referred to as additive materials) can be used to prepare additive-material-containing master pellets that have an additive material in a concentration higher than the desired amount in the cycloolefin resin in advance. Good. In that case, it is necessary to prepare a cycloolefin resin master pellet (cycloolefin resin master pellet) that does not include any additional material. In that case, the addition amount in the additive material-containing master pellet is not particularly limited, but is preferably 2 to 50 times the final concentration of the additive material in the cycloolefin resin film, more preferably 2 to 30 times, and further 3 to 25 times, particularly 4 to 20 times. The following methods can be used for mixing the cycloolefin resin master pellets and the additive material-containing master pellets.

  When the additive material is mixed after the cycloolefin resin is prepared as a powder, it is important to mix uniformly because the powders are mixed. That is, when the additive material is powder, it is effective to use a mixing device in order to uniformly mix the cycloolefin resin powder. Examples of the mixing device include a container rotating type, a container fixing type, or a composite type thereof. Specifically, a rotating horizontal type (horizontal cylinder, inclined cylinder, V type, twentieth pyramid, square body, S Shape, continuous V shape, etc.), rotation axis horizontal (eg, ribbon, screw, rod, pin, double axis paddle, etc.), rotation vertical (ribbon, screw, conical screw, high speed flow, rotating disc, maller, etc.) ), Vibration type (vibration mill, sieve, etc.), and internal blade type (horizontal cylinder, V type, double cone, etc.) can be used as the rotation type. During mixing, it is desirable to control the humidity, temperature, and oxygen concentration so that the additive material and the cycloolefin resin are stable. Lower humidity and temperature are preferred. That is, the preferred relative humidity is 70% or less, more preferably 50% or less, still more preferably 350% or less, and particularly preferably 20% or less. The temperature is preferably −20 to 100 ° C., more preferably 0 to 80 ° C., further preferably 5 to 60 ° C., and particularly preferably 10 to 50 ° C.

  The oxygen concentration is preferably low, and the oxygen concentration in the gas is preferably 10% by volume or less, more preferably 5% by volume or less, still more preferably 2% by volume or less, and particularly preferably 1%. The capacity is less than%. The method for reducing the oxygen concentration is not particularly limited, but it can be achieved by degassing with an inert gas (for example, nitrogen, argon, helium, etc.) or vacuum equipment. It is recommended that the cycloolefin resin mixture containing the additive material mixed in this way be melt pelletized or melt-cast while maintaining a low oxygen concentration. In addition, when it is made by melting in a low oxygen concentration atmosphere in the pelletizing step, it may not be necessary to control the oxygen concentration during melt film formation, and the load on the step is reduced.

《Filming》
(1) Pelletization The cycloolefin resin and the additive are preferably mixed and pelletized prior to melt film formation.
In the pelletization, the cycloolefin resin and the additive are preferably dried in advance, but drying can be substituted by using a vented extruder. In the case of drying, as the drying method, a method of heating at 90 ° C. for 8 hours or more in a heating furnace can be used, but not limited thereto. Pelletization can be performed by melting the cycloolefin resin and the additive at 150 ° C. to 280 ° C. using a twin-screw kneading extruder, then extruding the noodle into a solid and cutting it in water. Further, pelletization may be performed by an underwater cutting method or the like that is cut while being directly extruded from a die after being melted by an extruder.
Any known single-screw extruder, non-meshing counter-rotating twin-screw extruder, meshing-type counter-rotating twin-screw extruder, meshing co-direction as long as the melter kneading is sufficient A rotary twin screw extruder or the like can be used.

The size of the pellets is preferably cross-sectional area of 1 mm ² to 300 mm ^2, a length of 1Mm～30mm, cross-sectional area 2 mm ² 100 mm ^2, and more preferably the length is 1.5mm~10mm .
Moreover, when pelletizing, the said additive can also be injected | thrown-in from the raw material input port and vent port in the middle of an extruder.

The number of revolutions of the extruder is preferably 10 rpm to 1000 rpm, more preferably 20 rpm to 700 rpm, and even more preferably 30 rpm to 500 rpm. A rotational speed of 10 rpm or more is preferable because the residence time does not become too long, and the molecular weight decreases due to thermal deterioration or the yellowishness tends to be deteriorated. Further, when the rotation speed is 1000 rpm or less, it becomes difficult for molecules to be cut by shearing, and problems such as a decrease in molecular weight and an increase in the generation of cross-linked gel are less likely to occur.
The extrusion residence time in pelletization is preferably 10 seconds to 30 minutes, more preferably 15 seconds to 10 minutes, and even more preferably 30 seconds to 3 minutes. If sufficient melting is possible, a shorter residence time is preferable in terms of suppressing resin deterioration and yellowing.

(2) Drying It is preferable to reduce moisture in the pellets prior to melt film formation. The drying method is often dried using a dehumidifying air dryer, but is not particularly limited as long as the desired moisture content can be obtained. For example, it is preferable to carry out it efficiently by using means such as heating, air blowing, decompression and stirring alone or in combination, and it is more preferable that the drying hopper has a heat insulating structure. Preferably it is 0-200 degreeC as drying temperature, More preferably, it is 40-180 degreeC, More preferably, it is 60-150 degreeC. When the drying temperature is low, drying takes time, and the moisture content tends to be less than the target value. On the other hand, when the drying temperature is high, the resin tends to adhere and easily block. The amount of drying air used is preferably a 20 to 400 m ³ / hour, more preferably from 50 to 300 m ³ / time, more preferably from 100 to 250 m ³ / hour. If the amount of drying air is small, the drying efficiency tends to deteriorate. On the other hand, even if the air volume is increased, if it exceeds a certain amount, further improvement of the drying effect is small and not economical. The dew point of air is preferably 0 to -60 ° C, more preferably -10 to -50 ° C, and further preferably -20 to -40 ° C. The drying time usually needs at least 15 minutes or more, preferably 1 hour or more, and more preferably 2 hours or more. On the other hand, even if it is dried for more than 50 hours, there is little effect of reducing the moisture content, and there is a tendency for the thermal deterioration of the resin to occur, so it is not necessary to unnecessarily increase the drying time. The cycloolefin resin employed in the present invention preferably has a moisture content of 1.0% by mass or less, more preferably 0.1% by mass or less, and further preferably 0.01% by mass or less. preferable.

(3) Melt extrusion The above-mentioned cycloolefin resin is supplied into the cylinder through the supply port of the extruder. The inside of the cylinder was melt-kneaded and compressed in order from the supply port side, a supply part (region A) for quantitatively transporting cycloolefin resin supplied from the supply port, and a compression unit (region B) for melt-kneading and compressing cycloolefin resin. It is comprised with the measurement part (area | region C) which measures cycloolefin resin. The cycloolefin resin is preferably dried in order to reduce the water content by the above-described method. However, in order to prevent the molten resin from being oxidized by the remaining oxygen, the inside of the extruder is in an inert (nitrogen or the like) air stream, or More preferably, it is carried out while evacuating using an extruder with a vent. The screw compression ratio of the extruder is set to 2.5 to 4.5, and L / D is set to 20 to 70. Here, the screw compression ratio is expressed by the volume ratio between the supply unit A and the metering unit C, that is, the volume per unit length of the supply unit A ÷ the volume per unit length of the metering unit C. It is calculated using the outer diameter d1 of the shaft, the outer diameter d2 of the screw shaft of the measuring part C, the groove part diameter a1 of the supply part A, and the groove part diameter a2 of the measuring part C. L / D is the ratio of the cylinder length to the cylinder inner diameter. Moreover, extrusion temperature is set to 200-300 degreeC. The temperatures in the extruder may all be the same temperature or may have a temperature distribution. More preferably, the temperature of the supply section is made higher than the temperature of the compression section.

  If the screw compression ratio is less than 2.5 and is too small, it will not be melted and kneaded sufficiently, undissolved parts will be generated, undissolved foreign matter will easily remain in the manufactured cycloolefin resin film, and bubbles will be mixed It becomes easy to do. As a result, the strength of the cycloolefin resin film is reduced, or when the film is stretched, the film is easily broken and the orientation cannot be sufficiently increased. On the other hand, if the screw compression ratio exceeds 4.5 and is too large, the shear stress is excessively applied and the resin is easily deteriorated due to heat generation, so that a yellowish color is likely to appear in the manufactured cycloolefin resin film. In addition, when too much shear stress is applied, molecular cutting occurs, the molecular weight decreases, and the mechanical strength of the cycloolefin resin film decreases. Therefore, the screw compression ratio is preferably in the range of 2.5 to 4.5 in order to make the cycloolefin resin film after production hardly yellow, and the cycloolefin resin film has high strength and is difficult to stretch and break. 2.8 to 4.2 is more preferable, and 3.0 to 4.0 is more preferable.

  On the other hand, if L / D is less than 20 and is too small, melting and kneading are insufficient, and undissolved foreign matter is likely to be generated in the manufactured cycloolefin resin film as in the case where the compression ratio is small. On the contrary, if L / D exceeds 70 and is too large, the residence time of the cycloolefin resin in the extruder becomes too long, and the resin tends to be deteriorated. In addition, when the residence time is long, the molecules are cut or the molecular weight is lowered, so that the mechanical strength of the cycloolefin resin film is lowered. Accordingly, the L / D range is preferably 20 to 70, and more preferably 22 to 65, in order to make the cycloolefin resin film after production hardly yellow, and the film strength is strong and further makes it difficult to stretch and break. 24-50 are more preferable.

  The cycloolefin resin film thus obtained preferably has a characteristic value having a haze of 2.0% or less and a yellow index (YI value) of 10 or less.

In general, single-screw extruders with relatively low equipment costs are often used as the types of extruders, and there are screw types such as full flight, madok and dalmage, but cycloolefin resins are full flight types. Is preferred. In addition, although the equipment cost is expensive, it is possible to use a twin-screw extruder that can be extruded while devolatilizing unnecessary volatile components by providing a vent port in the middle by changing the screw segment. There are two types of shaft extruders, the same direction and the different direction, which can be used. However, the type of the same direction rotation with high self-cleaning performance is preferred because a stagnant portion is hardly generated. By properly arranging the vent port, it is possible to use the cycloolefin resin pellets and powder in an undried state as they are. In addition, film smears produced during film formation can be reused as they are without drying.
In addition, although the diameter of a preferable screw changes with target extrusion rates per unit time, it is 10 mm-300 mm normally, More preferably, it is 20 mm-250 mm, More preferably, it is 30 mm-150 mm.

(4) Filtration It is preferable to perform so-called breaker plate type filtration in which a filter medium is provided at the outlet of the extruder for filtering foreign matter in the resin and avoiding damage to the gear pump due to foreign matter. At this time, it can be achieved by adjusting the pore diameter of the filter medium and the flow rate of the molten resin as described above.
In order to filter foreign matter with higher accuracy, it is preferable to provide a filtration device incorporating a so-called leaf type disk filter after passing through the gear pump. Filtration can be performed by providing one filtration section, or multistage filtration performed by providing a plurality of places. The filtration accuracy of the filter medium is preferably higher. However, the filtration accuracy is preferably 15 μm to 3 μm, more preferably 10 μm to 3 μm from the viewpoint of the pressure resistance of the filter medium and the increase in the filtration pressure due to clogging of the filter medium. In particular, when using a leaf-type disk filter device that finally filters foreign matter, it is preferable to use a filter medium with high filtration accuracy in terms of quality, and it is adjusted by the number of loaded sheets to ensure the suitability of pressure resistance and filter life. Is possible. The type of filter medium is preferably a steel material because it is used under high temperature and high pressure. Among steel materials, it is more preferable to use stainless steel, steel, etc., and stainless steel is particularly preferable from the viewpoint of corrosion. Further preferred. As a configuration of the filter medium, in addition to a knitted wire, for example, a sintered filter medium formed by sintering a metal long fiber or metal powder can be used, and a sintered filter medium is preferable in terms of filtration accuracy and filter life.

(5) Gear pump In order to improve the thickness accuracy, it is important to reduce the fluctuation of the discharge amount. A gear pump is provided between the extruder and the die, and a certain amount of cycloolefin resin is supplied from the gear pump. That is effective. A gear pump is accommodated in a state where a pair of gears composed of a drive gear and a driven gear are engaged with each other, and the drive gear is driven to engage and rotate the two gears, so that a melted state is generated from the suction port formed in the housing. The resin is sucked into the cavity, and a predetermined amount of cycloolefin resin is discharged from the discharge port formed in the housing. Even if there is a slight fluctuation in the resin pressure at the front end of the extruder, the fluctuation is absorbed by using a gear pump, the fluctuation in the resin pressure downstream of the film forming apparatus becomes very small, and the thickness fluctuation is improved. By using a gear pump, it is possible to keep the fluctuation range of the resin pressure in the die portion within ± 1%.

  In order to improve the quantitative supply performance by the gear pump, a method of controlling the pressure before the gear pump to be constant by changing the number of rotations of the screw can also be used. In addition, a high-precision gear pump using three or more gears that eliminates gear fluctuations of the gear pump is also effective.

  Other advantages of using a gear pump are that the pressure at the tip of the screw can be reduced to form a film, reducing energy consumption, preventing rise in resin temperature, improving transport efficiency, reducing residence time in the extruder, Shortening of L / D can be expected. Also, when using a filter to remove foreign matter, if there is no gear pump, the amount of cycloolefin resin supplied from the screw may fluctuate as the filtration pressure increases. It can be solved by using it. On the other hand, the disadvantage of the gear pump is that the length of the equipment becomes longer depending on the equipment selection method, the residence time of the cycloolefin resin becomes longer, and the molecular chain of the cycloolefin resin is broken by the shear stress of the gear pump part. Sometimes it needs attention.

The preferred residence time of the cycloolefin resin from the time when the cycloolefin resin enters the extruder to the time when it exits the die is 2 minutes to 60 minutes, more preferably 3 minutes to 40 minutes, and even more preferably 4 minutes. ~ 30 minutes.
Since the flow of the polymer for bearing circulation of the gear pump is deteriorated, the polymer seal in the drive part and the bearing part is deteriorated, and there is a problem that the fluctuation of the metering and liquid feeding pressure is increased. A gear pump design (especially clearance) that matches the melt viscosity is required. In some cases, the staying part of the gear pump causes deterioration of the cycloolefin resin, and therefore a structure with as little staying as possible is preferable. The polymer pipes and adapters that connect the extruder and gear pump or gear pump and die, etc. must also be designed with as little stagnation as possible, and in order to stabilize the extrusion pressure of cycloolefin resins with high melt viscosity temperature dependence. It is preferable to make the temperature fluctuation as small as possible. Generally, a band heater having a low equipment cost is often used for heating the polymer tube, but it is more preferable to use an aluminum cast heater with less temperature fluctuation. Further, in the extruder as described above, it is preferable that the barrel of the extruder is heated and melted with a heater divided into 3 to 20.

(6) Die The cycloolefin resin is melted by the extruder configured as described above, and the molten resin is continuously sent to the die via a filter and a gear pump as necessary. As long as the die is designed so that the molten resin stays in the die, any type of commonly used T die, fishtail die, and hanger coat die may be used. Moreover, there is no problem to insert a static mixer for improving the uniformity of the cycloolefin resin temperature immediately before the T die. The clearance of the T-die outlet portion is generally preferably 1.0 to 5.0 times, more preferably 1.2 to 3 times, and even more preferably 1.3 to 2 times the film thickness. By making the lip clearance 1.0 times or more of the film thickness, a more excellent sheet can be obtained by film formation. Moreover, it exists in the tendency for the thickness precision of a sheet to improve by making lip clearance 5.0 times or less of film thickness. The die is a very important facility for determining the thickness accuracy of the film, and is preferably one that can strictly control the thickness adjustment. The interval for adjusting the thickness is preferably 50 mm or less, more preferably 35 mm or less, and preferably 25 mm or less. Further, in order to improve the uniformity of the film-forming film, it is important to design as little as possible of the temperature unevenness of the die and the flow velocity unevenness in the width direction. An automatic thickness adjustment die that measures the downstream film thickness, calculates the thickness deviation, and feeds back the result to the die thickness adjustment is also effective in reducing the thickness fluctuation in long-term continuous production.
The die land length / Thailand width is preferably 5 to 40.
For production of a film, a single-layer film forming apparatus with a low equipment cost is generally used. However, in some cases, a film having two or more types of structures can also be manufactured using a multilayer film forming apparatus in order to provide a functional layer on an outer layer. Is possible. In general, the functional layer is preferably thinly laminated on the surface layer, but the layer ratio is not particularly limited.

(7) Casting Under the above conditions, the molten resin extruded from the die onto the sheet is cooled and solidified on the casting drum to obtain a film. In the present invention, the touch roll method is used.
The touch roll method forms a film surface by placing a touch roll on a casting drum. At this time, the touch roll is preferably not elastic and usually elastic. However, an elastically deformable member (rubber or the like) covered with a very thin metal is not preferable because the surface pressure cannot be increased. This is because the amount of deformation of the touch roll is large, the contact area with the cast roll becomes too large, and sufficient surface pressure cannot be produced. The thickness of the touch roll of the present invention is preferably 0.5 mm to 7 mm, more preferably 1.1 to 6 mm, and further preferably 1.5 to 5 mm. The touch roll and casting roll preferably have a mirror surface, and the arithmetic average height Ra is preferably 100 nm or less, more preferably 50 nm or less, and further preferably 25 nm or less. The surface pressure of the touch roll is preferably 0.1 MPa to 10 MPa, more preferably 0.2 MPa to 7 MPa, and further preferably 0.3 MPa to 6 MPa. The surface pressure referred to here is a value obtained by dividing the force pressing the touch roll by the contact area between the cycloolefin resin film and the touch roll.
The touch roll may be installed on a metal shaft and a heat medium (fluid) may be passed between them. An elastic layer is provided between the outer cylinder and the metal shaft, and the heat medium (fluid) is filled between the outer cylinders. Can be mentioned. The temperature of the touch roll is preferably (Tg−10) ° C. and (Tg + 30) ° C. or less, more preferably (Tg−7) ° C. to (Tg + 20) ° C., further preferably (Tg−5) ° C. to (Tg + 15). ) ° C. The temperature of the casting roll is preferably in the same temperature range.
Specifically, for example, touch rolls described in JP-A-11-314263 and JP-A-11-235747 can be used as the touch roll.

  More preferably, a plurality of casting drums (rolls) are used for slow cooling. Of these, the touch roll is preferably used so as to touch the first casting roll on the most upstream side (closer to the die). In general, it is relatively common to use three cooling rolls, but this is not a limitation. The diameter of the roll is preferably 50 mm to 5000 mm, more preferably 100 mm to 2000 mm, and still more preferably 150 mm to 1000 mm. The interval between the plurality of rolls is preferably 0.3 mm to 300 mm, more preferably 1 mm to 100 mm, and even more preferably 3 mm to 30 mm between the surfaces. The line speed (circumferential speed) on the most upstream side of the cast roll is preferably 20 m / min to 70 m / min.

(8) Winding After peeling off from the casting drum, it winds up through a nip roll.
The film forming width is preferably 0.7 m to 5 m, more preferably 1 m to 4 m, and still more preferably 1.3 m to 3 m. The thickness of the unstretched film thus obtained is preferably 20 μm to 250 μm, more preferably 25 μm to 200 μm, and still more preferably 30 μm to 180 μm.

It is also preferable to trim both ends before winding. As the trimming cutter, any type of rotary cutter, shear blade, knife, or the like may be used. Any material such as carbon steel or stainless steel may be used. In general, it is preferable to use a cemented carbide blade or a ceramic blade because the life of the blade is long and the generation of chips is suppressed. The portion cut off by trimming may be crushed and used again as a raw material.
It is also preferable to perform a thickness increasing process (knurling process) at one or both ends. The height of the unevenness by the thicknessing process is preferably 1 μm to 200 μm, more preferably 10 μm to 150 μm, and still more preferably 20 μm to 100 μm. Thickening processing may be convex on both sides or convex on one side. The width of the thickness increasing process is preferably 1 mm to 50 mm, more preferably 3 mm to 30 mm, and still more preferably 5 mm to 20 mm. Extrusion can be performed at room temperature to 300 ° C.

The cycloolefin resin film thus formed may be stretched as it is (online stretching), or after being wound up once, it may be sent out again and stretched (offline stretching).
At the time of winding, it is also preferable to attach a lami film on at least one side from the viewpoint of preventing scratches. The thickness of the laminated film is preferably 5 μm to 200 μm, more preferably 10 μm to 150 μm, still more preferably 10 μm to 120 μm, and particularly preferably 15 μm to 100 μm.

The winding tension is preferably 1 kg / m width to 50 kg / width, more preferably 2 kg / m width to 40 kg / width, and even more preferably 3 kg / m width to 20 kg / width. When the winding tension is smaller than 1 kg / m width, it is difficult to wind the film uniformly. On the other hand, when the winding tension exceeds 50 kg / width, the film becomes tightly wound, not only the appearance of the winding is deteriorated, but also the bump portion of the film extends due to the creep phenomenon, and the film wave This is not preferable because it causes a cause or residual birefringence due to the elongation of the film. It is preferable that the winding tension is detected by tension control in the middle of the line and wound while being controlled so as to have a constant winding tension. If there is a difference in film temperature depending on the location of the film production line, the length of the film may be slightly different due to thermal expansion. It is necessary to prevent tension.
The winding tension can be wound at a constant tension by controlling the tension control. However, it is more preferable that the winding tension is tapered according to the wound diameter to obtain an appropriate winding tension. Generally, the tension is gradually reduced as the winding diameter increases, but in some cases, it may be preferable to increase the tension as the winding diameter increases.

<< Extension process >>
The melt-formed cycloolefin resin film may be subjected to transverse stretching and / or longitudinal stretching, and may be subjected to relaxation treatment in combination with these. These can be implemented by, for example, the following combinations.
(1) transverse stretching (2) transverse stretching → relaxation treatment (3) longitudinal stretching → lateral stretching (4) longitudinal stretching → lateral stretching → relaxation treatment (5) longitudinal stretching → relaxation treatment → lateral stretching → relaxation treatment (6) transverse Stretching → Longitudinal stretching → Relaxation treatment (7) Transverse stretching → Relaxation treatment → Longitudinal stretching → Relaxation treatment (8) Longitudinal stretching → Transverse stretching → Longitudinal stretching (9) Longitudinal stretching → Transverse stretching → Longitudinal stretching → Relaxation treatment (10) Longitudinal Stretching (11) Longitudinal stretching → relaxation treatment Among these, (1) to (4) and (10) to (11) are more preferable, and (2), (4) and (11) are more preferable. ). Among these, (1) to (4) are more preferable, and (2) and (4) are more preferable.
Furthermore, by such uniform stretching, the molecules that have been rounded in the film can be efficiently stretched. As a result, entanglement can be formed between the molecules, and the breaking strength can be improved.

(Longitudinal stretching)
Longitudinal stretching can be achieved by installing two pairs of nip rolls and heating the gap between them so that the peripheral speed of the nip roll on the outlet side is higher than the peripheral speed of the nip roll on the inlet side. Under the present circumstances, the expression of the retardation of the thickness direction can be changed by changing the space | interval (L) between nip rolls, and the film width (W) before extending | stretching. Rth can be reduced when the ratio L / W (referred to as aspect ratio) of longitudinal stretching to lateral stretching is more than 2 and 50 or less (long span stretching), and Rth when the aspect ratio is 0.01 to 0.3 (short span stretching). Can be increased. In the present invention, any of long span stretching, short span stretching, and stretching in the region between them (intermediate stretching = L / W exceeds 0.3 and 2 or less) may be used. Span stretching or short span stretching is preferred. Furthermore, when it is desired to obtain a high Rth, short span stretching is preferred, and when it is desired to obtain a low Rth, a long span stretching can be appropriately selected and employed.

(1-1) Although the film is stretched along with the long span stretching, the thickness and width of the film are reduced so as to reduce the volume change. At this time, shrinkage in the width direction is limited by friction between the nip roll and the film. For this reason, when the nip roll interval is increased, shrinkage in the width direction is facilitated, and thickness reduction can be suppressed. When the thickness reduction is large, the same effect as that in which the film is compressed in the thickness direction is obtained. On the contrary, when the aspect ratio is large and the thickness reduction is small, Rth hardly appears and low Rth can be realized.
Furthermore, if the aspect ratio is long, the uniformity in the width direction can be improved. This is due to the following reason.
• The film tends to shrink in the width direction as it is stretched. At the center in the width direction, both sides try to shrink in the width direction, so it becomes a tug-of-war and cannot shrink freely.
・ On the other hand, the film width direction end is only in a tug-of-war state with one side and can shrink relatively freely.
-The difference in shrinkage behavior associated with the stretching between both ends and the central portion becomes stretching unevenness in the width direction.
Due to such non-uniformity between both ends and the center, retardation in the width direction and axial deviation (orientation angle distribution of slow axis) occur. On the other hand, since long span stretching is performed slowly between two long nip rolls, uniformity of these non-uniformities (molecular orientation becomes uniform) proceeds during stretching. On the other hand, in normal longitudinal stretching (aspect ratio = more than 0.3 and less than 2), such homogenization does not occur.

The aspect ratio exceeds 2 and is preferably 50 or less, more preferably 3 to 40, and still more preferably 4 to 20. The stretching temperature is preferably (Tg-5 ° C) to (Tg + 100) ° C, more preferably (Tg) to (Tg + 50) ° C, and still more preferably (Tg + 5) to (Tg + 30) ° C. The draw ratio is preferably 1.05 to 3 times, more preferably 1.05 to 1.7 times, and still more preferably 1.05 to 1.4 times. Such long span stretching may be performed in multiple stages with three or more pairs of nip rolls as long as the longest aspect ratio is within the above range.
Such long span stretching may be performed by heating the film between two pairs of nip rolls separated by a predetermined distance. The heating method is a heater heating method (infrared heater, halogen heater, panel heater, etc. above or below the film). Or heating by radiant heat) or a zone heating method (heating in a zone in which hot air or the like is blown and adjusted to a predetermined temperature) may be used. In the present invention, the zone heating method is preferable from the viewpoint of uniformity of the stretching temperature. At this time, the nip roll may be installed in the stretching zone or out of the zone, but it is preferably out of the zone in order to prevent the film and the nip roll from sticking. It is also preferable to preheat the film before such stretching, and the preheating temperature is (Tg-80) ° C to (Tg + 100) ° C.

By such stretching, the Re value is preferably 0 to 200 nm, more preferably 10 to 200 nm, still more preferably 15 nm to 100 nm, and the Rth value is, for example, 0 to 600 nm, preferably 30 to 500 nm, more preferably 50 It is -400 nm, More preferably, it is 70-350 nm. By this stretching method, the ratio of Rth and Re (Rth / Re) can be 0.4 to 0.6, more preferably 0.45 to 0.55. Furthermore, by this stretching, the variation in Re value and Rth value can be preferably 5% or less, more preferably 4% or less, and still more preferably 3% or less.
With such stretching, the ratio of the film width before and after stretching (film width after stretching / film width before stretching) is preferably 0.5 to 0.9, more preferably 0.6 to 0.85, More preferably, it becomes 0.65-0.83.

(1-2) Short span stretching aspect ratio (L / W) is preferably more than 0.01 and less than 0.3, more preferably 0.03 to 0.25, and still more preferably 0.05 to 0.2. Perform longitudinal stretching (short span stretching). By performing stretching at an aspect ratio (L / W) in such a range, neck-in (shrinkage in the direction orthogonal to stretching accompanying stretching) can be reduced. Although the width and thickness are reduced to compensate for stretching in the stretching direction, such short span stretching suppresses width shrinkage and preferentially reduces the thickness. As a result, the film is compressed in the thickness direction, and the orientation (plane orientation) in the thickness direction proceeds. As a result, Rth, which is a measure of anisotropy in the thickness direction, tends to increase. On the other hand, conventionally, the aspect ratio (L / W) is generally about 1 (0.7 to 1.5). This is usually done by installing a heater for heating between the nip rolls, but if the L / W is too large, the film cannot be heated uniformly with the heater and uneven stretching tends to occur. If the L / W is too small, the heater is stretched. This is because it is difficult to install and cannot be heated sufficiently.
The short span stretching described above can be performed by changing the conveyance speed between two or more pairs of nip rolls, but unlike the normal roll arrangement (FIG. 1), the two pairs of nip rolls are inclined (the rotation axis of the front and rear nip rolls is moved up and down). This can be achieved by disposing (Fig. 2). Accordingly, since a heater for heating cannot be installed between the nip rolls, it is preferable to raise the temperature of the film by flowing a heating medium in the nip rolls. Further, it is also preferable to provide a preheating roll in which a heat medium is flowed inside before the inlet side nip roll, and to heat the film before stretching. In FIG. 1 and FIG. 2, 1 indicates a nip roll, 2 indicates a heater, and 3 indicates a film.
The stretching temperature is preferably (Tg-5 ° C) to (Tg + 100) ° C, more preferably (Tg) to (Tg + 50) ° C, and still more preferably (Tg + 5) to (Tg + 30) ° C. The preheating temperature is preferably (Tg−80) ° C. to (Tg + 100) ° C.

(Lateral stretching)
The transverse stretching can be performed using a tenter. That is, the film is stretched by holding both ends in the width direction with clips and widening the film in the lateral direction. At this time, the stretching temperature can be controlled by sending wind at a desired temperature into the tenter. The stretching temperature is preferably (Tg-10) ° C to (Tg + 60) ° C, more preferably (Tg-5) ° C to (Tg + 45) ° C, and further preferably Tg to (Tg + 30) ° C.
By performing preheating before stretching and heat setting after stretching, the Re and Rth distribution after stretching can be reduced, and the variation in orientation angle associated with bowing can be reduced. Either preheating or heat setting may be performed, but both are more preferable. These preheating and heat setting are preferably performed by holding with a clip, that is, preferably performed continuously with stretching.
Preheating is preferably performed at a temperature higher than the stretching temperature by 1 ° C to 50 ° C, more preferably 2 ° C to 40 ° C, and even more preferably 3 ° C to 30 ° C. The preheating time is preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, and still more preferably 10 seconds to 2 minutes. During preheating, it is preferable to keep the width of the tenter substantially constant. Here, “substantially” refers to ± 10% of the width of the unstretched film, for example.
The heat setting is preferably 1 to 50 ° C., more preferably 2 to 40 ° C., and further preferably 3 to 30 ° C. lower than the stretching temperature. More preferably, it is less than the stretching temperature and less than Tg. The preheating time is preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, and still more preferably 10 seconds to 2 minutes. During the heat setting, it is preferable to keep the width of the tenter substantially constant. Here, “substantially” refers to 0% (the same width as the tenter width after stretching) to −10% (shrinking by 10% from the tenter width after stretching = reduced width) of the tenter width after stretching. If the width is wider than the stretched width, residual strain is likely to occur in the film, and it is not preferable because it is likely to increase the variation with time of Re and Rth.
Thus, it is preferable that the heat setting temperature <the stretching temperature <the preheating temperature.
The reason why the variation in orientation angle and Re and Rth can be reduced by such preheating and heat setting is as follows. That is, as shown in FIG. 3A, when preheating temperature = stretching temperature = preheating temperature, the film is stretched in the width direction and tends to be thinned in the orthogonal direction (longitudinal direction) (neck-in). For this reason, the film before and after transverse stretching is pulled and stress is generated. However, both ends in the width direction are fixed by chucks and are not easily deformed by stress, and the central portion in the width direction is easily deformed. As a result, the stress caused by the neck-in is deformed into a bow shape and bowing occurs. As a result, in-plane Re and Rth unevenness and distribution of orientation axes occur. Therefore, as shown in FIG. 3 (b), by setting the heat setting temperature <stretching temperature <preheating temperature, the temperature on the preheating side (before stretching) is increased and the temperature on the heat treatment (after stretching) is decreased. In is generated on the high temperature side (preheating) having a lower elastic modulus and is less likely to be generated by heat treatment (after stretching). As a result, bowing after stretching can be suppressed.

By such stretching, the variation of Re and Rth in the width direction and the longitudinal direction can be preferably 5% or less, more preferably 4% or less, and still more preferably 3% or less. Further, the orientation angle can be preferably 90 ° ± 5 ° or less or 0 ° ± 5 ° or less, more preferably 90 ° ± 3 ° or less or 0 ° ± 3 ° or less, and further preferably 90 ° ± 1 °. Or 0 ° ± 1 ° or less.
The present invention is characterized in that such an effect can be achieved even at high speed stretching, and the effect is remarkably exhibited even at 20 m / min or more, more preferably 25 m / min or more, and even more preferably 30 m / min or more.

(Relaxation treatment)
Furthermore, dimensional stability can be improved by performing relaxation treatment after these stretching. The thermal relaxation is preferably performed after longitudinal stretching, either after lateral stretching, or after both, and more preferably after lateral stretching. The relaxation treatment may be performed online continuously after stretching, or may be performed offline after winding after stretching.
The relaxation treatment is preferably performed at a temperature of (Tg-30) ° C to (Tg + 30) ° C, more preferably (Tg-30) ° C to (Tg + 20) ° C, and even more preferably (Tg-15) ° C to (Tg + 10) ° C. , Preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, even more preferably 10 seconds to 2 minutes, preferably 0.1 kg / m to 20 kg / m, more preferably 1 kg / m to 16 kg / m More preferably, it is carried out while transporting at a tension of 2 kg / m to 12 kg / m.

(Volatile component during stretching)
In the longitudinal stretching and lateral stretching, the volatile components (solvent, moisture, etc.) are preferably 1% by mass or less, more preferably 0.5% by mass or less, and still more preferably 0.3% by mass or less with respect to the resin. Thereby, the axial shift generated during stretching can be further reduced. This is because during the stretching, in addition to the shrinkage stress acting in the direction perpendicular to the stretching, the shrinkage stress accompanying drying acts, and the bowing becomes more prominent.

(Physical properties after stretching)
It is preferable that Re and Rth of the cycloolefin resin film thus longitudinally stretched, laterally stretched, and longitudinally and laterally satisfy the following formulas (R-1) and (R-2).
Formula (R-1): 0 nm ≦ Re ≦ 200 nm
Formula (R-2): 0 nm ≦ Rth ≦ 600 nm
(In the formula, Re represents in-plane retardation of the cycloolefin resin film, and Rth represents the thickness direction retardation of the cycloolefin resin film.)

More preferably, Rth ≧ Re × 1.1
180 ≧ Re ≧ 10
400 ≧ Rth ≧ 50
More preferably, Rth ≧ Re × 1.2
150 ≧ Re ≧ 20
300 ≧ Rth ≧ 100
It is.

The angle θ formed by the film forming direction (longitudinal direction) and the slow axis of Re of the film is preferably closer to 0 °, + 90 °, or −90 °. That is, in the case of longitudinal stretching, it is preferably as close to 0 °, preferably 0 ± 3 °, more preferably 0 ± 2 °, and further preferably 0 ± 1 °. In the case of transverse stretching, 90 ± 3 ° or −90 ± 3 ° is preferable, 90 ± 2 ° or −90 ± 2 ° is more preferable, and 90 ± 1 ° or −90 ± 1 ° is more preferable.
The variation of Re and Rth is preferably 0 to 8%, more preferably 0 to 5%, and still more preferably 0 to 3%.
Further, the fluctuations of Re and Rth under storage (changes in Re and Rth before and after 500 hours at 80 ° C .: details will be described later) are preferably 0 to 8%, more preferably 0 to 6%. Preferably it is 0 to 4%.
The thickness of the cycloolefin resin film after stretching is preferably 15 μm to 200 μm, more preferably 20 μm to 120 μm, and further preferably 30 μm to 80 μm. The thickness unevenness is preferably 3% or less, more preferably 2% or less, and even more preferably 1% or less in both the longitudinal direction and the width direction. By using a thin film, residual strain is less likely to remain in the film after stretching, and retardation changes with time are less likely to occur. This is because when cooling after stretching, if the thickness is thick, the internal cooling is delayed as compared to the surface, and residual strain due to the difference in thermal shrinkage tends to occur.
The thermal dimensional change rate is preferably 0.5% or less, more preferably 0.3% or less, and further preferably 0.2% or less. The thermal dimensional change rate means a dimensional change when heat-treated at 80 ° C. for 5 hours.

<< Processing of cycloolefin resin film >>
The cycloolefin resin film of the present invention thus obtained may be used alone, or may be used in combination with a polarizing plate or the like using the cycloolefin resin film as a base material. Alternatively, a layer having a controlled refractive index (low reflection layer) or a hard coat layer may be provided. These can be achieved by the following steps.
(surface treatment)
Glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment here includes a low temperature plasma treatment performed under a low pressure gas of 10 ^{−3 to} 20 Torr (0.13 to 2700 Pa). Further, plasma treatment under atmospheric pressure is also a preferable glow discharge treatment.
A plasma-excitable gas is a gas that is plasma-excited under the above-described conditions, and examples thereof include chlorofluorocarbons such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, tetrafluoromethane, and mixtures thereof. It is done. Details of these are described in detail on pages 30 to 32 in the Journal of the Invention Association (Technology No. 2001-1745, issued on March 15, 2001, Invention Association). Note that, in the plasma treatment at atmospheric pressure which has been attracting attention in recent years, for example, irradiation energy of 20 to 500 KGy is used under 10 to 1000 Kev, and more preferably irradiation energy of 20 to 300 KGy is used under 30 to 500 Kev.
Of these, glow discharge treatment, corona treatment, and flame treatment are particularly preferred.
It is also preferable to provide an undercoat layer for adhesion to the functional layer. This layer may be coated after the surface treatment or may be coated without the surface treatment. Details of the undercoat layer are described on page 32 of the Japan Society for Invention and Innovation (Public Technical Number 2001-1745, published on March 15, 2001, Japan Institute of Invention).
These surface treatment and undercoating processes can be incorporated at the end of the film forming process, can be performed alone, or can be performed in the functional layer application process described later.

<< Use of the cycloolefin resin film of the present invention >>
The cycloolefin resin film of the present invention is combined with the functional layer described in detail on pages 32 to 45 of the Japan Society for Invention and Technology (Public Technical Number 2001-1745, issued on March 15, 2001, Japan Society of Invention). It is preferable. Among these, application of a polarizing film (polarizing plate), application of an optical compensation layer (optical compensation sheet), and application of an antireflection layer (antireflection film) are preferable. This will be described in order below.

(1) Application of polarizing film (preparation of polarizing plate)
(Material used)
At present, commercially available polarizing films are generally prepared by immersing a stretched polymer in a solution of iodine or dichroic dye in a bath and allowing the iodine or dichroic dye to penetrate into the binder. is there. As the polarizing film, a coating type polarizing film represented by Optiva Inc. can also be used. The iodine and the dichroic dye in the polarizing film develop polarizing performance by being oriented in the binder. As the dichroic dye, an azo dye, stilbene dye, pyrazolone dye, triphenylmethane dye, quinoline dye, oxazine dye, thiazine dye or anthraquinone dye is used. The dichroic dye is preferably water-soluble. The dichroic dye preferably has a hydrophilic substituent (for example, sulfo, amino, hydroxyl). For example, the compound described in page 58 of the Society of Invention Disclosure Technique (public technical number 2001-1745, issue date March 15, 2001, Society of Invention).

  As the binder for the polarizing film, either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used. Examples of the binder include methacrylate copolymer, styrene copolymer, polyolefin, polyvinyl alcohol and modified polyvinyl alcohol, poly (N-methylolacrylamide) described in paragraph No. [0022] of JP-A-8-338913. , Polyester, polyimide, vinyl acetate copolymer, carboxymethyl cellulose, polycarbonate and the like. Silane coupling agents can be used as the polymer. Water-soluble polymers (for example, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, and modified polyvinyl alcohol) are preferable, gelatin, polyvinyl alcohol, and modified polyvinyl alcohol are more preferable, and polyvinyl alcohol and modified polyvinyl alcohol are most preferable. . It is particularly preferable to use two types of polyvinyl alcohol or modified polyvinyl alcohol having different degrees of polymerization. The saponification degree of polyvinyl alcohol is preferably 70 to 100%, more preferably 80 to 100%. It is preferable that the polymerization degree of polyvinyl alcohol is 100-5000. The modified polyvinyl alcohol is described in JP-A-8-338913, JP-A-9-152509 and JP-A-9-316127. Two or more kinds of polyvinyl alcohol and modified polyvinyl alcohol may be used in combination.

  The lower limit of the binder thickness is preferably 10 μm. The upper limit of the thickness is preferably as thin as possible from the viewpoint of light leakage of the liquid crystal display device. It is preferably not more than a commercially available polarizing plate (about 30 μm), preferably 25 μm or less, and more preferably 20 μm or less.

  The binder of the polarizing film may be cross-linked. A polymer or monomer having a crosslinkable functional group may be mixed in the binder, or a crosslinkable functional group may be imparted to the binder polymer itself. Crosslinking can be performed by light, heat, or pH change, and a binder having a crosslinked structure can be formed. The crosslinking agent is described in US Reissue Patent 23297. Boron compounds (for example, boric acid and borax) can also be used as a crosslinking agent. The addition amount of the crosslinking agent in the binder is preferably 0.1 to 20% by mass with respect to the binder. The orientation of the polarizing element and the wet heat resistance of the polarizing film are improved.

  Even after the crosslinking reaction is completed, the unreacted crosslinking agent is preferably 1.0% by mass or less, and more preferably 0.5% by mass or less. By doing in this way, a weather resistance improves.

(Stretching)
The polarizing film is preferably dyed with iodine or a dichroic dye after the polarizing film is stretched (stretching method) or rubbed (rubbing method).

  In the stretching method, the stretching ratio is preferably 2.5 to 30.0 times, and more preferably 3.0 to 10.0 times. Stretching can be performed by dry stretching in air. Moreover, you may implement wet extending | stretching in the state immersed in water. The stretch ratio of dry stretching is preferably 2.5 to 5.0 times, and the stretch ratio of wet stretching is preferably 3.0 to 10.0 times. These stretching operations may be performed once or divided into several times. By dividing into several times, it is possible to stretch more uniformly even at high magnification. Stretching can be carried out by the following method.

  Prior to stretching, the PVA film is swollen. The degree of swelling is 1.2 to 2.0 times (mass ratio before swelling and after swelling). Thereafter, the film is stretched at a bath temperature of 15 to 50 ° C., particularly 17 to 40 ° C. in an aqueous medium bath or a dye bath for dissolving a dichroic substance while being continuously conveyed through a guide roll or the like. Stretching can be achieved by gripping with two pairs of nip rolls and increasing the conveyance speed of the subsequent nip roll to be higher than that of the previous nip roll. The draw ratio is based on the length ratio after stretching / initial state (hereinafter the same), but the preferred draw ratio is 1.2 to 3.5 times, particularly 1.5 to 3.0 times in view of the above-mentioned effects. . Thereafter, the film is dried at 50 ° C. to 90 ° C. to obtain a polarizing film.

[Lamination]
A polarizing plate is prepared by laminating the saponified cycloolefin resin film and a polarizing film prepared by stretching. The laminating direction is preferably such that the casting axis direction of the cycloolefin resin film and the stretching axis direction of the polarizing plate are 45 degrees.

  The adhesive for bonding is not particularly limited, but examples thereof include PVA resins (including modified PVA such as acetoacetyl group, sulfonic acid group, carboxyl group, oxyalkylene group) and boron compound aqueous solution. preferable. The thickness of the adhesive layer is preferably 0.01 to 10 μm, and particularly preferably 0.05 to 5 μm after drying.

  The polarizing plate thus obtained preferably has a higher light transmittance, and preferably has a higher degree of polarization. The transmittance of the polarizing plate is preferably in the range of 30 to 50%, more preferably in the range of 35 to 50%, and most preferably in the range of 40 to 50% in light having a wavelength of 550 nm. . The degree of polarization is preferably in the range of 90 to 100%, more preferably in the range of 95 to 100%, and most preferably in the range of 99 to 100% in light having a wavelength of 550 nm.

  Furthermore, the polarizing plate thus obtained can be laminated with a λ / 4 plate to produce circularly polarized light. In this case, lamination is performed so that the slow axis of λ / 4 and the absorption axis of the polarizing plate are 45 degrees. At this time, λ / 4 is not particularly limited, but more preferably has a wavelength dependency such that the lower the wavelength, the smaller the retardation. Furthermore, it is preferable to use a polarizing film having an absorption axis inclined by 20 ° to 70 ° with respect to the longitudinal direction and a λ / 4 plate made of an optically anisotropic layer made of a liquid crystalline compound.

(2) Application of optical compensation layer (creation of optical compensation sheet)
The optically anisotropic layer is for compensating the liquid crystal compound in the liquid crystal cell in the black display of the liquid crystal display device, and forms an alignment film on the cycloolefin resin film, and further provides an optically anisotropic layer. It is formed by doing.

(Alignment film)
An alignment film is provided on the surface-treated cycloolefin resin film. This film has a function of defining the alignment direction of liquid crystalline molecules. However, if the alignment state is fixed after aligning the liquid crystalline compound, the alignment film plays the role, and thus is not necessarily an essential component of the present invention. That is, it is possible to produce the polarizing plate of the present invention by transferring only the optically anisotropic layer on the alignment film in which the alignment state is fixed onto the polarizer.

  The alignment film is an organic compound (for example, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably a polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodget method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.

  The alignment film is preferably formed by polymer rubbing treatment. In principle, the polymer used for the alignment film has a molecular structure having a function of aligning liquid crystal molecules.

  In the present invention, in addition to the function of aligning liquid crystalline molecules, a crosslink having a function of aligning a side chain having a crosslinkable functional group (for example, a double bond) to the main chain or aligning liquid crystalline molecules. It is preferable to introduce a functional functional group into the side chain.

  As the polymer used for the alignment film, either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used. Examples of the polymer include methacrylate copolymers, styrene copolymers, polyolefins, polyvinyl alcohol and modified polyvinyl alcohol, poly (N-methylol) described in paragraph No. [0022] of JP-A-8-338913. Acrylamide), polyester, polyimide, vinyl acetate copolymer, carboxymethylcellulose, polycarbonate and the like. Silane coupling agents can be used as the polymer. Water-soluble polymers (for example, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, and modified polyvinyl alcohol) are preferable, gelatin, polyvinyl alcohol, and modified polyvinyl alcohol are more preferable, and polyvinyl alcohol and modified polyvinyl alcohol are most preferable. . It is particularly preferable to use two types of polyvinyl alcohol or modified polyvinyl alcohol having different degrees of polymerization. The saponification degree of polyvinyl alcohol is preferably 70 to 100%, more preferably 80 to 100%. It is preferable that the polymerization degree of polyvinyl alcohol is 100-5000.

  A side chain having a function of aligning liquid crystal molecules generally has a hydrophobic group as a functional group. The specific type of functional group is determined according to the type of liquid crystal molecule and the required alignment state. For example, the modifying group of the modified polyvinyl alcohol can be introduced by copolymerization modification, chain transfer modification or block polymerization modification. Examples of modifying groups include hydrophilic groups (carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, amino groups, ammonium groups, amide groups, thiol groups, etc.), hydrocarbon groups having 10 to 100 carbon atoms, fluorine atoms Substituted hydrocarbon groups, thioether groups, polymerizable groups (unsaturated polymerizable groups, epoxy groups, azirinidyl groups, etc.), alkoxysilyl groups (trialkoxy, dialkoxy, monoalkoxy) and the like can be mentioned. As specific examples of these modified polyvinyl alcohol compounds, for example, paragraph numbers [0022] to [0145] in JP-A No. 2000-155216 and paragraph numbers [0018] to [0018] in JP-A No. 2002-62426 are described. [0022] and the like.

  When a side chain having a crosslinkable functional group is bonded to the main chain of the alignment film polymer, or a crosslinkable functional group is introduced into a side chain having a function of aligning liquid crystalline molecules, the alignment film polymer and the optically anisotropic film The polyfunctional monomer contained in the conductive layer can be copolymerized. As a result, not only between the polyfunctional monomer and the polyfunctional monomer, but also between the alignment film polymer and the alignment film polymer and between the polyfunctional monomer and the alignment film polymer is firmly bonded by a covalent bond. Therefore, the strength of the optical compensation sheet can be remarkably improved by introducing the crosslinkable functional group into the alignment film polymer.

  The crosslinkable functional group of the alignment film polymer preferably contains a polymerizable group in the same manner as the polyfunctional monomer. Specific examples include those described in paragraphs [0080] to [0100] in JP-A-2000-155216. Apart from the crosslinkable functional group, the alignment film polymer can also be crosslinked using a crosslinking agent.

  Examples of the crosslinking agent include aldehydes, N-methylol compounds, dioxane derivatives, compounds that act by activating carboxyl groups, active vinyl compounds, active halogen compounds, isoxazole and dialdehyde starch. Two or more kinds of crosslinking agents may be used in combination. Specific examples include compounds described in paragraphs [0023] to [024] in JP-A No. 2002-62426. Aldehydes having high reaction activity, particularly glutaraldehyde are preferred.

  0.1-20 mass% is preferable with respect to a polymer, and, as for the addition amount of a crosslinking agent, 0.5-15 mass% is more preferable. The amount of the unreacted crosslinking agent remaining in the alignment film is preferably 1.0% by mass or less, and more preferably 0.5% by mass or less. By adjusting in this way, even if the alignment film is used for a long time in a liquid crystal display device or left in a high-temperature and high-humidity atmosphere for a long time, sufficient durability without generation of reticulation can be obtained.

  The alignment film can be basically formed by applying the polymer on the transparent support containing the alignment film forming material and the crosslinking agent, followed by drying by heating (crosslinking) and rubbing treatment. As described above, the crosslinking reaction may be performed at any time after coating on the transparent support. When a water-soluble polymer such as polyvinyl alcohol is used as the alignment film forming material, the coating liquid is preferably a mixed solvent of an organic solvent (for example, methanol) having a defoaming action and water. The ratio of water: methanol is preferably 0: 100 to 99: 1, and more preferably 0: 100 to 91: 9. Thereby, generation | occurrence | production of a bubble is suppressed and the defect of the layer surface of an alignment film and also an optical anisotropic layer reduces remarkably.

  The alignment film is preferably applied by spin coating, dip coating, curtain coating, extrusion coating, rod coating, or roll coating. A rod coating method is particularly preferable. The film thickness after drying is preferably 0.1 to 10 μm. Heating and drying can be performed at 20 ° C to 110 ° C. In order to form sufficient cross-linking, 60 ° C to 100 ° C is preferable, and 80 ° C to 100 ° C is particularly preferable. The drying time can be 1 minute to 36 hours, preferably 1 minute to 30 minutes. The pH is preferably set to an optimum value for the crosslinking agent to be used. When glutaraldehyde is used, the pH is 4.5 to 5.5, and 5 is particularly preferable.

  The alignment film is provided on the transparent support or the undercoat layer. The alignment film can be obtained by rubbing the surface after crosslinking the polymer layer as described above.

  For the rubbing treatment, a treatment method widely adopted as a liquid crystal alignment treatment process of LCD can be applied. That is, a method of obtaining the orientation by rubbing the surface of the orientation film in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like can be used. Generally, it is carried out by rubbing several times using a cloth or the like in which fibers having a uniform length and thickness are planted on average.

When industrially implemented, this is achieved by bringing a rotating rubbing roll into contact with the film with the polarizing film being transported. However, the roundness, cylindricity, and deflection (eccentricity) of the rubbing roll can be any. Is preferably 30 μm or less. The film wrap angle on the rubbing roll is preferably 0.1 to 90 °. However, as described in JP-A-8-160430, a stable rubbing treatment can be obtained by winding 360 ° or more. As for the conveyance speed of a film, 1-100 m / min is preferable. It is preferable to select an appropriate rubbing angle in the range of 0 to 60 °. When used for a liquid crystal display device, 40 to 50 ° is preferable. 45 ° is particularly preferred.
The thickness of the alignment film thus obtained is preferably in the range of 0.1 to 10 μm.

  Next, the liquid crystalline molecules of the optically anisotropic layer are aligned on the alignment film. Thereafter, as necessary, the alignment film polymer and the polyfunctional monomer contained in the optically anisotropic layer are reacted, or the alignment film polymer is crosslinked using a crosslinking agent.

  The liquid crystalline molecules used in the optically anisotropic layer include rod-like liquid crystalline molecules and discotic liquid crystalline molecules. The rod-like liquid crystal molecules and the disk-like liquid crystal molecules may be high-molecular liquid crystals or low-molecular liquid crystals, and further include those in which low-molecular liquid crystals are cross-linked and no longer exhibit liquid crystallinity.

(Rod-like liquid crystalline molecules)
Examples of rod-like liquid crystalline molecules include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used.

  The rod-like liquid crystalline molecule includes a metal complex. In addition, a liquid crystal polymer containing a rod-like liquid crystalline molecule in a repeating unit can also be used as the rod-like liquid crystalline molecule. In other words, the rod-like liquid crystal molecule may be bonded to a (liquid crystal) polymer.

  For rod-like liquid crystalline molecules, see Chapter 4, Chapter 7 and Chapter 11 of the Chemistry of the Quarterly Chemistry Vol. 22 (1994) The Chemical Society of Japan, and the 142th Committee of the Japan Society for the Promotion of Science. Described in Chapter 3.

  The birefringence of the rod-like liquid crystal molecule is preferably in the range of 0.001 to 0.7.

  The rod-like liquid crystalline molecule preferably has a polymerizable group in order to fix its alignment state. The polymerizable group is preferably a radically polymerizable unsaturated group or a cationically polymerizable group. Specifically, for example, the polymerizable group described in paragraphs [0064] to [0086] of JP-A-2002-62427 is described. And polymerizable liquid crystal compounds.

(Discotic liquid crystalline molecules)
For discotic liquid crystal molecules, C.I. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985), Physics lett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984) and the cyclohexane derivatives described in J. Am. M.M. Lehn et al. Chem. Commun. , 1794 (1985), J. Am. Zhang et al., J. Am. Chem. Soc. 116, 2655 (1994), azacrown type and phenylacetylene type macrocycles are included.

  As a discotic liquid crystalline molecule, a compound having liquid crystallinity having a structure in which a linear alkyl group, an alkoxy group, and a substituted benzoyloxy group are radially substituted as a side chain of the mother nucleus with respect to the mother nucleus at the center of the molecule Is also included. The molecule or the assembly of molecules is preferably a compound having rotational symmetry and imparting a certain orientation. In the optically anisotropic layer formed from the discotic liquid crystalline molecules, the compound finally contained in the optically anisotropic layer does not need to be a discotic liquid crystalline molecule. Also included are compounds having a group that reacts with heat or light and, as a result, polymerized or cross-linked by reaction with heat or light, resulting in a high molecular weight and loss of liquid crystallinity. Preferred examples of the discotic liquid crystalline molecules are described in JP-A-8-50206. The polymerization of discotic liquid crystalline molecules is described in JP-A-8-27284.

  In order to fix the discotic liquid crystalline molecules by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystalline molecules. A compound in which the discotic core and the polymerizable group are bonded via a linking group is preferable, whereby the orientation state can be maintained even in the polymerization reaction. Examples thereof include compounds described in paragraph numbers [0151] to [0168] in JP-A 2000-155216.

  In the hybrid alignment, the angle between the major axis (disk surface) of the discotic liquid crystalline molecule and the surface of the polarizing film increases or decreases in the depth direction of the optically anisotropic layer and with increasing distance from the surface of the polarizing film. is doing. The angle preferably decreases with increasing distance. Further, the change in angle can be a continuous increase, a continuous decrease, an intermittent increase, an intermittent decrease, a change including a continuous increase and a continuous decrease, or an intermittent change including an increase and a decrease. The intermittent change includes a region where the inclination angle does not change in the middle of the thickness direction. Even if the angle includes a region where the angle does not change, the angle only needs to increase or decrease as a whole. Furthermore, it is preferable that the angle changes continuously.

  The average direction of the major axis of the discotic liquid crystalline molecules on the polarizing film side can be generally adjusted by selecting a discotic liquid crystalline molecule or an alignment film material, or by selecting a rubbing treatment method. In addition, the major axis (disk surface) direction of the surface-side (air-side) discotic liquid crystalline molecules is generally adjusted by selecting the type of additive used together with the discotic liquid crystalline molecules or discotic liquid crystalline molecules. be able to. Examples of the additive used together with the discotic liquid crystalline molecule include a plasticizer, a surfactant, a polymerizable monomer and a polymer. The degree of change in the orientation direction of the major axis can also be adjusted by selecting liquid crystalline molecules and additives as described above.

(Other composition of optically anisotropic layer)
Along with the liquid crystal molecules, a plasticizer, a surfactant, a polymerizable monomer, etc. can be used in combination to improve the uniformity of the coating film, the strength of the film, the orientation of the liquid crystal molecules, and the like. It is preferable that the compound has compatibility with the liquid crystal molecules and can change the tilt angle of the liquid crystal molecules or does not inhibit the alignment.

  Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Preferably, it is a polyfunctional radically polymerizable monomer and is preferably copolymerizable with the above-described polymerizable group-containing liquid crystal compound. Examples thereof include those described in paragraph numbers [0018] to [0020] in JP-A No. 2002-296423. The amount of the compound added is generally in the range of 1 to 50% by mass and preferably in the range of 5 to 30% by mass with respect to the discotic liquid crystalline molecules.

  Examples of the surfactant include conventionally known compounds, and fluorine compounds are particularly preferable. Specific examples include compounds described in paragraph numbers [0028] to [0056] in JP-A-2001-330725.

  The polymer used together with the discotic liquid crystalline molecule is preferably capable of changing the tilt angle of the discotic liquid crystalline molecule.

  A cellulose ester can be mentioned as an example of a polymer. Preferable examples of the cellulose ester include those described in paragraph [0178] of JP-A No. 2000-155216. The addition amount of the polymer is preferably in the range of 0.1 to 10% by mass, and in the range of 0.1 to 8% by mass with respect to the liquid crystal molecule so as not to inhibit the alignment of the liquid crystal molecules. It is more preferable.

  The discotic nematic liquid crystal phase-solid phase transition temperature of the discotic liquid crystalline molecules is preferably 70 to 300 ° C, more preferably 70 to 170 ° C.

(Formation of optically anisotropic layer)
The optically anisotropic layer can be formed by applying a coating liquid containing liquid crystalline molecules and, if necessary, a polymerization initiator described later and optional components on the alignment film.

  As the solvent used for preparing the coating solution, an organic solvent is preferably used. Examples of organic solvents include amides (eg N, N-dimethylformamide), sulfoxides (eg dimethyl sulfoxide), heterocyclic compounds (eg pyridine), hydrocarbons (eg benzene, hexane), alkyl halides (eg , Chloroform, dichloromethane, tetrachloroethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination.

The coating liquid can be applied by a known method (for example, a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, or a die coating method).
The thickness of the optically anisotropic layer is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and most preferably 1 to 10 μm.

(Fixing the alignment state of liquid crystalline molecules)
The aligned liquid crystal molecules can be fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. A photopolymerization reaction is preferred.

  Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatic acyloin. Compound (described in US Pat. No. 2,722,512), polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (US Pat. No. 3,549,367) Acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (U.S. Pat. No. 4,212,970).

  The amount of the photopolymerization initiator used is preferably in the range of 0.01 to 20% by mass, more preferably in the range of 0.5 to 5% by mass, based on the solid content of the coating solution.

It is preferable to use ultraviolet rays for light irradiation for polymerization of liquid crystalline molecules. The irradiation energy is preferably in the range of ^{20mJ / cm 2 ~50J / cm 2} , more preferably in the range of 20~5000mJ / cm ^2, more preferably in the range of 100 to 800 mJ / cm ² . In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.
A protective layer may be provided on the optically anisotropic layer.

  It is also preferable to combine this optical compensation film and a polarizing film. Specifically, the optically anisotropic layer is formed by applying the coating liquid for the optically anisotropic layer as described above to the surface of the polarizing film. As a result, without using a polymer film between the polarizing film and the optically anisotropic layer, a thin polarizing plate having a small stress (strain × cross-sectional area × elastic modulus) associated with the dimensional change of the polarizing film is produced. . When the polarizing plate according to the present invention is attached to a large liquid crystal display device, an image with high display quality can be displayed without causing problems such as light leakage.

  The tilt angle of the polarizing film and the optical compensation layer may be stretched so as to match the angle formed by the transmission axis of the two polarizing plates bonded to both sides of the liquid crystal cell constituting the LCD and the vertical or horizontal direction of the liquid crystal cell. preferable. A normal inclination angle is 45 °. Recently, however, devices that are not necessarily 45 ° have been developed in transmissive, reflective, and transflective LCDs, and it is preferable that the stretching direction can be arbitrarily adjusted according to the design of the LCD.

(3) Application of antireflection layer (antireflection film)
The antireflection film generally includes a low refractive index layer which is also an antifouling layer, and at least one layer having a higher refractive index than that of the low refractive index layer (that is, a high refractive index layer and a medium refractive index layer). It has the structure provided above.

  Colloidal metal by multilayer deposition of transparent thin films of inorganic compounds (metal oxides, etc.) with different refractive indexes by chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, sol-gel method of metal compounds such as metal alkoxides Examples include a method of forming a thin film by post-processing (ultraviolet irradiation: JP-A-9-157855, plasma processing: JP-A-2002-327310) after forming an oxide particle film.

  On the other hand, various antireflection films formed by laminating thin films in which inorganic particles are dispersed in a matrix have been proposed as antireflection films with high productivity.

  The antireflection film which consists of an antireflection film which gave the anti-glare property which the surface of the uppermost layer has the shape of a fine unevenness to the antireflection film by application | coating as mentioned above is also mentioned.

  The cycloolefin resin film of the present invention can be applied to any of the above methods, but a coating method (coating type) is particularly preferable.

(Layer structure of coating type antireflection film)
An antireflection film having a layer structure of at least a medium refractive index layer, a high refractive index layer, and a low refractive index layer (outermost layer) on the substrate is designed to have a refractive index satisfying the following relationship.

The refractive index of the high refractive index layer> The refractive index of the medium refractive index layer> The refractive index of the transparent support> The refractive index of the low refractive index layer. Also, a hard coat layer is provided between the transparent support and the medium refractive index layer. Also good. Furthermore, it may consist of a medium refractive index hard coat layer, a high refractive index layer and a low refractive index layer.

Examples thereof include JP-A-8-122504, JP-A-8-110401, JP-A-10-300902, JP-A-2002-243906, JP-A-2000-11706, and the like.
Other functions may be imparted to each layer, for example, an antifouling low refractive index layer or an antistatic high refractive index layer (for example, JP-A-10-206603, JP-A-2002). -243906 publication etc.) etc. are mentioned.

  The haze of the antireflection film is preferably 5% or less, more preferably 3% or less. The strength of the film is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400.

(High refractive index layer and medium refractive index layer)
The layer having a high refractive index of the antireflection film is composed of a curable film containing at least an inorganic compound ultrafine particle having a high refractive index having an average particle size of 100 nm or less and a matrix binder.

  Examples of the high refractive index inorganic compound fine particles include inorganic compounds having a refractive index of 1.65 or more, preferably those having a refractive index of 1.9 or more. Examples thereof include oxides such as Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, and In, and composite oxides containing these metal atoms.

  In order to obtain such ultrafine particles, the surface of the particles is treated with a surface treatment agent (for example, as described in JP-A Nos. 11-295503, 11-153703, and 2000-9908). Silane coupling agent, etc .: Anionic compounds or organometallic coupling agents described in JP 2001-310432 A, etc., and a core-shell structure with high refractive index particles as a core (JP 2001-166104 A) Etc.) and specific dispersants (for example, JP-A-11-153703, US Pat. No. 6,210,858B1, JP-A-2002-27776069, etc.) and the like.

  Examples of the material forming the matrix include conventionally known thermoplastic resins and curable resin films.

  Furthermore, it is selected from a polyfunctional compound-containing composition containing at least two radically polymerizable and / or cationically polymerizable groups, an organometallic compound containing a hydrolyzable group, and a partial condensate composition thereof. At least one composition is preferred. Examples thereof include compounds described in JP-A Nos. 2000-47004, 2001-315242, 2001-31871, and 2001-296401.

  A curable film obtained from a colloidal metal oxide obtained from a hydrolyzed condensate of metal alkoxide and a metal alkoxide composition is also preferred. For example, it describes in Unexamined-Japanese-Patent No. 2001-293818.

  The refractive index of the high refractive index layer is generally 1.70 to 2.20. The thickness of the high refractive index layer is preferably 5 nm to 10 μm, and more preferably 10 nm to 1 μm.

  The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.50 to 1.70.

(Low refractive index layer)
The low refractive index layer is sequentially laminated on the high refractive index layer. The refractive index of the low refractive index layer is usually 1.20 to 1.55. Preferably it is 1.30-1.50.

  It is preferable to construct as the outermost layer having scratch resistance and antifouling property. As means for greatly improving the scratch resistance, imparting slipperiness to the surface is effective, and conventionally known means for thin film layers including introduction of silicone, introduction of fluorine, and the like can be applied.

  The refractive index of the fluorine-containing compound is preferably 1.35 to 1.50. More preferably, it is 1.36-1.47. The fluorine-containing compound is preferably a compound containing a crosslinkable or polymerizable functional group containing fluorine atoms in the range of 35 to 80% by mass.

  For example, paragraph numbers [0018] to [0026] of Japanese Patent Application Laid-Open No. 9-222503, paragraph numbers [0019] to [0030] of Japanese Patent Application Laid-Open No. 11-38202, and paragraph numbers of Japanese Patent Application Laid-Open No. 2001-40284. [0027] to [0028], JP-A 2000-284102, and the like.

  The silicone compound is a compound having a polysiloxane structure, preferably containing a curable functional group or a polymerizable functional group in the polymer chain and having a crosslinked structure in the film. For example, reactive silicone (for example, Silaplane (manufactured by Chisso Corporation), silanol group-containing polysiloxane (Japanese Patent Laid-Open No. 11-258403, etc.) and the like can be mentioned.

  The crosslinking or polymerization reaction of the fluorine-containing and / or siloxane polymer having a crosslinking or polymerizable group is carried out at the same time or after the coating composition for forming the outermost layer containing a polymerization initiator, a sensitizer, etc. It is preferable to carry out by light irradiation or heating.

  Also preferred is a sol-gel cured film in which an organometallic compound such as a silane coupling agent and a specific fluorine-containing hydrocarbon group-containing silane coupling agent are cured by a condensation reaction in the presence of a catalyst.

  For example, a polyfluoroalkyl group-containing silane compound or a partially hydrolyzed condensate thereof (Japanese Patent Laid-Open Nos. 58-142958, 58-147483, 58-147484, Japanese Patent Laid-Open Nos. 9-157582, 11) -106704), silyl compounds containing a poly "perfluoroalkyl ether" group which is a fluorine-containing long chain group (Japanese Patent Application Laid-Open Nos. 2000-117902, 2001-48590, 2002) 53804), and the like.

  The low refractive index layer has an average primary particle diameter of 1 to 150 nm such as a filler (for example, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride)) as an additive other than the above. Low refractive index inorganic compounds, organic fine particles described in paragraphs [0020] to [0038] of JP-A-11-3820, etc.), silane coupling agents, slip agents, surfactants, and the like can be contained.

  When the low refractive index layer is located below the outermost layer, the low refractive index layer may be formed by a vapor phase method (vacuum deposition method, sputtering method, ion plating method, plasma CVD method, etc.). The coating method is preferable because it can be manufactured at a low cost.

  The film thickness of the low refractive index layer is preferably 30 to 200 nm, more preferably 50 to 150 nm, and most preferably 60 to 120 nm.

(Hard coat layer)
The hard coat layer is provided on the surface of the transparent support in order to impart physical strength to the antireflection film. In particular, it is preferably provided between the transparent support and the high refractive index layer.

  The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of a light and / or heat curable compound. The curable functional group is preferably a photopolymerizable functional group, and the hydrolyzable functional group-containing organometallic compound is preferably an organic alkoxysilyl compound.

Specific examples of these compounds are the same as those exemplified for the high refractive index layer.
Specific examples of the constituent composition of the hard coat layer include those described in JP-A Nos. 2002-144913, 2000-9908, and WO 00/46617.

  The high refractive index layer can also serve as a hard coat layer. In such a case, it is preferable to form fine particles dispersed in the hard coat layer using the method described for the high refractive index layer.

  The hard coat layer can also serve as an antiglare layer (described later) provided with particles having an average particle size of 0.2 to 10 μm to provide an antiglare function (antiglare function).

  The film thickness of the hard coat layer can be appropriately designed depending on the application. The film thickness of the hard coat layer is preferably 0.2 to 10 μm, more preferably 0.5 to 7 μm.

  The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400. Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

(Forward scattering layer)
The forward scattering layer is provided in order to give a viewing angle improvement effect when the viewing angle is inclined in the vertical and horizontal directions when applied to a liquid crystal display device. By dispersing fine particles having different refractive indexes in the hard coat layer, it can also serve as a hard coat function.

  For example, Japanese Patent Application Laid-Open No. 11-38208 specifying a forward scattering coefficient, Japanese Patent Application Laid-Open No. 2000-199809 having a relative refractive index of a transparent resin and fine particles in a specific range, and Japanese Patent Application Laid-Open No. 2002 specifying a haze value of 40% or more. -107512 gazette etc. are mentioned.

(Other layers)
In addition to the above layers, a primer layer, an antistatic layer, an undercoat layer, a protective layer, and the like may be provided.

(Application method)
Each layer of the antireflection film is formed by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, micro gravure method or extrusion coating method (US Pat. No. 2,681,294). According to the specification, it can be formed by coating.

(Anti-glare function)
The antireflection film may have an antiglare function that scatters external light. The antiglare function is obtained by forming irregularities on the surface of the antireflection film. When the antireflection film has an antiglare function, the haze of the antireflection film is preferably 3 to 30%, more preferably 5 to 20%, and most preferably 7 to 20%.

  As a method for forming irregularities on the surface of the antireflection film, any method can be applied as long as these surface shapes can be sufficiently maintained. For example, a method of forming irregularities on the film surface using fine particles in the low refractive index layer (for example, JP 2000-271878 A), a lower layer of the low refractive index layer (high refractive index layer, medium refractive index layer) Alternatively, a small amount (0.1 to 50% by mass) of relatively large particles (particle size 0.05 to 2 μm) is added to the hard coat layer to form a surface uneven film, and these shapes are maintained thereon. A method of providing a low refractive index layer (for example, JP 2000-281410 A, JP 2000-95893 A, JP 2001-100004 A, 2001-281407, etc.), an uppermost layer (antifouling layer) A method of physically transferring an uneven shape onto the surface after coating (for example, as an embossing method, JP-A-63-278839, JP-A-11-183710, JP-A-2000-275401) Wherein) and the like.

<Liquid crystal display device>
The cycloolefin resin film of this invention can be used conveniently for a liquid crystal display device. In particular, the cycloolefin resin film of the present invention is effective when used as an optical compensation sheet for a liquid crystal display device. When the film itself is used as an optical compensation sheet, the transmission axis of the polarizing element (described later) and the slow axis of the optical compensation sheet made of a cycloolefin resin film are arranged so as to be substantially parallel or perpendicular. It is preferable. Such an arrangement of the polarizing element and the optical compensation sheet is described in JP-A-10-48420. The liquid crystal display device includes a liquid crystal cell having a liquid crystal supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and at least one sheet between the liquid crystal cell and the polarizing element. An optical compensation sheet is arranged.
Below, the kind of liquid crystal display device which can apply the cycloolefin resin film of this invention is demonstrated.

(TN mode liquid crystal display)
It is most frequently used as a color TFT liquid crystal display device and is described in many documents. The alignment state in the liquid crystal cell in the TN mode black display is an alignment state in which the rod-like liquid crystalline molecules rise at the center of the cell and the rod-like liquid crystalline molecules lie in the vicinity of the cell substrate.

(OCB mode liquid crystal display)
This is a bend alignment mode liquid crystal cell in which rod-like liquid crystal molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell. Liquid crystal display devices using a bend alignment mode liquid crystal cell are disclosed in US Pat. Nos. 4,583,825 and 5,410,422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. Therefore, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode.
Similarly to the TN mode, the liquid crystal cell in the OCB mode is in a black display, and the alignment state in the liquid crystal cell is such that the rod-like liquid crystal molecules rise in the center of the cell and the rod-like liquid crystal molecules lie in the vicinity of the cell substrate. .

(VA mode liquid crystal display device)
The feature is that the rod-like liquid crystalline molecules are oriented substantially vertically when no voltage is applied. In the VA mode liquid crystal cell, (1) the rod-like liquid crystalline molecules are oriented substantially vertically when no voltage is applied. In addition to a narrowly defined VA mode liquid crystal cell (described in JP-A-2-176625) that is aligned substantially horizontally when a voltage is applied, (2) the VA mode is multi-domained to expand the viewing angle ( Liquid crystal cell (in MVA mode) (SID97, Digest of tech. Papers 28 (1997) 845), (3) Rod-like liquid crystal molecules are substantially vertically aligned when no voltage is applied, and twisted A liquid crystal cell in a domain alignment mode (n-ASM mode) (described in the proceedings 58-59 (1998) of the Japanese Liquid Crystal Society) and (4) a SURVAVAL mode liquid crystal cell (LCD interface) Announced at National 98).

(Other liquid crystal display devices)
The ECB mode and STN mode liquid crystal display devices can be optically compensated in the same way as described above.

The evaluation method and measurement method used in the present invention are described below.

<< Measurement method and evaluation method >>
Below, it describes about the measuring method and evaluation method of a cycloolefin resin film. The measurement values described in the present application are measured by the method described below.

(Roll dirt)
After the film formation length of 1000 m, the cast roll was visually observed to evaluate the dirt state.
A: Dirt was not seen on the cast roll.
B: Dirt was not observed on the cast roll, but slight adhesion of dirt was observed at the positions of both ends of the film.
C: Partial dirt was seen on the cast roll.
D: Dirt was seen on the entire surface of the cast roll.
The practical level is B or more.

(Thickness unevenness)
In each region of 10 m, 250 m, and 450 m in the length direction of the cycloolefin resin film, 7 points were sampled every 20 cm from the end in the width direction to prepare a total of 21 samples. These samples were conditioned at 25 ° C. and 60% relative humidity for 3 hours, the film thickness was measured under the same environment, and the difference between the maximum value and the minimum value obtained was evaluated as thickness unevenness. The smaller the value, the smaller the film thickness variation and the better.
As for the cycloolefin resin film of this invention, it is preferable that thickness nonuniformity is 2 micrometers or less, and it is more preferable that it is 1 micrometer or less.

(Atypical foreign object failure)
The length of 3 m was visually observed at an arbitrary length position in the length direction of the cycloolefin resin film, and irregular foreign substances present therein were counted. The smaller the numerical value, the better the film.
In the cycloolefin resin film of the present invention, the number of irregular foreign matter failures is preferably 10 or less, and more preferably 5 or less.

(Projected diagonal stripes)
In the evaluation of the projected oblique stripes, the obtained film is visually observed in the width direction, and the stripe-like unevenness observed obliquely with respect to the film forming direction is indicated by the number per 1 cm.
The cycloolefin resin film of the present invention has a projected oblique line of preferably 10 lines / cm or less, and more preferably 5 lines / cm or less.

(Absorbance)
A cycloolefin resin film is conditioned for 2 hours at 25 ° C. and 60% relative humidity, cut into a diameter of 5 cm, quickly placed in a 5 cm diameter aluminum tray, and heated in air in a muffle furnace at 250 ° C. for 0.5 hours. did. A 0.2 g sample after cooling was diluted with methylene chloride to a total volume of 10 ml to prepare a 2 mass% solution, and the absorbance at 380 nm was measured with an AKA phototube colorimeter, manufactured by KOTAKI Corporation. The amount of increase in absorption after heating (unit:%) was shown as the absorbance relative to the absorbance before heating. The larger the numerical value, the more the coloring component is added, and the worse the weather resistance of the film.
The cycloolefin resin film of the present invention has an absorbance at a wavelength of 380 nm of preferably 5% or less, and more preferably 2% or less.

(Light resistance)
In accordance with JIS 5400, using a sunshine weatherometer, a carbon olefin resin test piece (10 cm × 10 cm, thickness 100 μm) at a black panel temperature of 83 ° C. is rotated around the light source once per minute while being applied to a carbon arc. Exposure for 300 hours. The weather resistance was evaluated by the reduction rate of the total light transmittance of the film after the test. The determination was made according to the following criteria.
A: The decrease rate of the total light transmittance is less than 1%.
B: The decrease rate of the total light transmittance is 1% or more and less than 10%.
C: The reduction rate of the total light transmittance is 10% or more and less than 50%.
D: The reduction rate of the total light transmittance is 50% or more.
The practical level is B or more.

(Measurement of Tg)
20 mg of a sample was placed in a DSC measurement pan. This was heated to 30 ° C. to 250 ° C. at 10 ° C./min in a nitrogen stream and then cooled to 30 ° C. at −10 ° C./min. Thereafter, the temperature was raised again to 30 ° C. to 250 ° C., and the temperature at which the baseline began to deviate from the low temperature side was defined as Tg.

(Re and Rth)
The film was conditioned at 25 ° C. and 60% relative humidity for 24 hours, then using a prism coupler (MODEL2010 Prism Coupler: manufactured by Metricon), and at 25 ° C. and 60% relative humidity, using a 532 nm solid laser, the following formula (a The average refractive index (n) represented by
Formula (a): n = (n _TE × 2 + n _TM ) / 3
[ _Where n _TE is a refractive index measured with polarized light in the film plane direction, and n _TM is a refractive index measured with polarized light in the film surface normal direction. ]
Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at the wavelength λ, respectively. Re (λ) was measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).
When the film to be measured was represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) was calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (in the absence of the slow axis, any in-plane value) Measurements were made at 11 points in total by making light of wavelength λ nm incident from each inclined direction in steps of 10 ° from −50 ° to + 50 ° from the normal direction to the normal direction of the film). Then, KOBRA 21ADH or WR was calculated based on the measured retardation value, average refractive index, and input film thickness value.
In the above, there is no particular description regarding λ, and when only Re and Rth are described, it represents a value measured using light with a wavelength of 590 nm. In addition, in the case of a film having a retardation value of zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, the retardation value at a tilt angle larger than that tilt angle. After changing its sign to negative, KOBRA 21ADH or WR calculates.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (when there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the average refractive index, and the input film thickness value, Rth can also be calculated from the following formulas (b) and (c).

［式中、Ｒｅ（θ）は法線方向から角度θ傾斜した方向におけるレタ−デーション値を表す。また、ｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘおよびｎｙに直交する方向の屈折率を表す。］

[In the formula, Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction. Further, nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny. ]

Formula (c): Rth = ((nx + ny) / 2−nz) × d
In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) was calculated by the following method.
Rth (λ) is from −50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) and the tilt axis (rotation axis). Measured at 11 points by making light of wavelength λ nm incident from each inclined direction in 10 degree steps, and KOBRA 21ADH or WR is calculated based on the measured retardation value, average refractive index, and input film thickness value. did.
By inputting these average refractive index and film thickness, KOBRA 21ADH or WR was allowed to calculate nx, ny, and nz. Nz = (nx−nz) / (nx−ny) was further calculated from the calculated nx, ny, and nz.

(Re, Rth fluctuation, orientation angle)
Sampling is performed at 100 points in the longitudinal direction and 50 points in the width direction, and the angles of Re, Rth, and slow axis are measured by the above method. For the Re and Rth variations, the difference between each maximum value and the minimum value at 100 points in the MD direction and 50 points in the TD direction was divided by each average value, and the value expressed as a percentage was defined as the Re and Rth variation. Regarding the orientation angle, the difference between the maximum value and the minimum value of the slow axis angle at each measurement point is shown.

(Color shift)
The unstretched film is made into a polarizing plate by the method described in the examples described later, and is incorporated into a liquid crystal display device to form a neutral gray display on the entire surface, and the color shift is visually confirmed.
Since the projected diagonal stripe has a subtle structural difference, color misregistration is not visually recognized in the entire black display and white display. Therefore, the present invention employs such means.
In the examples described later, the color shift occurrence area expressed as a percentage divided over the entire screen is indicated as “color shift”.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

(1) Cycloolefin resin (i) Cycloolefin resin-A (ring-opening polymer)
6-methyl-1,4,5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 10 parts of a 15% cyclohexane solution of triethylaluminum as a polymerization catalyst, triethylamine 5 And 10 parts of a 20% cyclohexane solution of titanium tetrachloride were added to perform ring-opening polymerization in cyclohexane, and the resulting ring-opening polymer was hydrogenated with a nickel catalyst to obtain a polymer solution. This polymer solution was coagulated in isopropyl alcohol and dried to obtain a powdery resin. The number average molecular weight of this resin was 40,000, the hydrogenation rate was 99.8% or more, and the Tg was 139 ° C.

(Ii) Cycloolefin resin-B (ring-opening polymer)
100 parts by mass of 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.12.5, 17.10] -3-dodecene (specific monomer B) and 5- (4-biphenylcarbonyloxy) In a reaction vessel in which 150 parts by mass of bicyclo [2.2.1] hept-2-ene (specific monomer A), 18 parts by mass of 1-hexene (molecular weight regulator) and 750 parts by mass of toluene were substituted with nitrogen. Charge and heat the solution to 60 ° C. Next, 0.62 parts by mass of a toluene solution of triethylaluminum (1.5 mol / l) as a polymerization catalyst and tungsten hexachloride modified with tert-butanol and methanol (tert-butanol: methanol: By adding 3.7 parts by mass of a toluene solution (concentration 0.05 mol / l) of tungsten = 0.35 mol: 0.3 mol: 1 mol), the system is heated and stirred at 80 ° C. for 3 hours. A ring-opening polymer solution was obtained by a ring-opening polymerization reaction. The polymerization conversion rate in this polymerization reaction was 97%, and the intrinsic ring viscosity (ηinh) of the obtained ring-opened polymer measured in chloroform at 30 ° C. was 0.65 dl / g.

The autoclave was charged with 4,000 parts by mass of the ring-opening polymer solution thus obtained, and 0.48 part of RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ was added to the ring-opening polymer solution. The hydrogenation reaction was performed by heating and stirring for 3 hours under the conditions of hydrogen gas pressure of 100 kg / cm ² and reaction temperature of 165 ° C. After cooling the obtained reaction solution (hydrogenated polymer solution), the hydrogen gas was released. This reaction solution was poured into a large amount of methanol to separate and recover a coagulated product, which was dried to obtain a hydrogenated polymer (cyclic polyolefin resin). The hydrogenated polymer thus obtained was measured for hydrogenation rate of olefinically unsaturated bonds using 400 MHz, ¹ H-NMR, and found to be 99.9%. When the number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of polystyrene were measured by gel permeation chromatography (GPC method, solvent: tetrahydrofuran), the number average molecular weight (Mn) was 39,000, and the weight average molecular weight ( Mw) was 126,000, and the molecular weight distribution (Mw / Mn) was 3.23. Moreover, Tg was 110 degreeC.

(Iii) Cycloolefin resin-C (addition polymer)
The cycloolefin compound described in Example 2 of JP-A-2005-330465 (Tg = 127 ° C.)
(Iv) Cycloolefin resin-D (addition polymer)
The cycloolefin compound described in Example 1 of JP-T-8-507800 (Tg = 181 ° C.)
(V) Cycloolefin resin-E (addition polymer)
APL6015T (Tg = 145 ° C) manufactured by Mitsui Chemicals, Inc.
(Vi) Cycloolefin resin-F (addition polymer)
TOPAS6013 (Tg = 130 ° C) manufactured by Polyplastics Co., Ltd.

(2) Film formation Using the cycloolefin resins -A to F, the numbers of specific examples of the compound represented by the additive (general formula (HUV-1) described above are cited in Table 1. UVV- 11 is tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butane tetracarboxylate (molecular weight 792)), and a stabilizer ( 0.15% by mass of Sumilizer GP (manufactured by Sumitomo Chemical Co., Ltd.) was added as an antioxidant and stirred well with a Henschel mixer to prepare a resin mixture. The obtained mixture was molded into cylindrical pellets having an average diameter of 3 mm and an average length of 5 mm. This was dried with a vacuum dryer at 110 ° C., the water content was adjusted to 0.1% by mass or less, and charged into a hopper adjusted to Tg−10 ° C.
The mixture was melted at 260 ° C. with a kneading extruder. Thereafter, the melt fed from the gear pump was filtered through a leaf disk filter having a filtration accuracy of 5 μm.
Thereafter, a melt (molten resin) was extruded onto a cast roll (CR) from a hanger coat die having a slit interval of 1.0 mm and 260 ° C. The die land length / Thailand width was 0.003.
Thereafter, the film was cast on a cast roll set at a temperature Tg, and a touch roll having a touch roll surface pressure of 6 Mpa and a crown amount of 150 μm was brought into contact therewith. At this time, the temperature of the cast roll on the most upstream side in contact with the touch roll is (Tg + 15) ° C., the peripheral speed is 55 m / sec, and the difference between these touch rolls (touch roll value−cast roll value) is 0. 0.5%. The touch roll was the one described in Example 1 of JP-A No. 11-235747 (the one described as a double holding roll), and the temperature was adjusted to Tg-5 ° C. The thickness of the thin metal outer cylinder of this touch roll was 3 mm. Sample 13 is a comparative sample in which the touch roll was not performed.
Subsequently, after passing through a cast roll whose temperature was set to Tg + 5 ° C. and Tg−10 ° C., both ends (5% of the total width) were trimmed, and both ends were 10 mm wide and 50 μm high. Knurling) and laminating with a protective film having a thickness of 20 μm, an unstretched film having a width of 2.0 m and a length of 3000 m was obtained.
The “projected diagonal streaks” appearing on the film thus formed were measured according to the above method. The sample of the present invention was excellent in all of roll contamination, thickness unevenness, irregular foreign material failure, oblique projection streaks, absorbance (high temperature stability) and light weather resistance. However, comparative samples that do not contain UV absorbers or comparative samples that are not touch-rolled satisfy all of roll contamination, thickness unevenness, irregular foreign material failure, oblique projection streaks, absorbance, and light resistance. I couldn't.
All these items were comprehensively evaluated in four stages and listed in Table 1 (A: comprehensively excellent in all characteristics. B: comprehensively almost no problem. C: comprehensive problem. D: Cannot be used practically because of its large problems.) The addition polymerization type is relatively preferable to the ring-opening polymerization type.

(3) Stretching and relaxation The cycloolefin resin film obtained by the melt film formation was stretched and thermally relaxed under the conditions shown in Table 2. Although not described in the table, the unstretched film of the present invention described in Table 1 other than that described in Table 2 was stretched in the same manner, and similarly good results were obtained.

(4) Production of polarizing plate In any level, the surface of the film was subjected to corona treatment so that the contact angle with water on the surface was 60 °.
According to Example 1 of Japanese Patent Laid-Open No. 2001-141926, a circumferential speed difference was given between two pairs of nip rolls and stretched in the longitudinal direction to prepare a polarizing layer having a thickness of 20 μm.
These were bonded to each other using a PVA (PVA-117H manufactured by Kuraray Co., Ltd.) 3% aqueous solution so as to have the following constitution to produce a polarizing plate.
Polarizing plate E: Cycloolefin resin film / polarizing layer / Fujitack A polarizing plate obtained in this manner is a 50-inch VA type liquid crystal display device prepared according to FIGS. 2 to 9 of JP-A-2000-154261. It attached instead of the polarizing plate. In the case of carrying out the present invention, there was no planar failure and good performance was obtained. Among these, addition polymerization type cycloolefin resin films were good.

(5) Production of optical compensation film The cycloolefin resin film of the present invention was used in place of the cellulose acetate film coated with the liquid crystal layer of Example 1 of JP-A-11-316378. Those implementing the present invention showed good performance. Among them, the addition polymerization type cycloolefin resin film was good.

  In Example 1 of JP-A-7-333433, in place of the cellulose acetate film, a cycloolefin resin film of the present invention is employed, and an optical compensation filter film can be similarly produced. It was. Among them, the addition polymerization type cycloolefin resin film was good.

(6) Production of low-reflection film A low-reflection film was produced from the cycloolefin resin film of the present invention according to Example 47 of the Japan Society for Invention and Innovation (public technical number 2001-1745), and good optical performance was obtained. . In particular, the addition polymerization type cycloolefin resin film was good.

(7) Production of Liquid Crystal Display Element The polarizing plate of the present invention is a liquid crystal display device described in Example 1 of JP-A-10-48420, and a discotic described in Example 1 of JP-A-9-26572. An optically anisotropic layer containing liquid crystal molecules, an alignment film coated with polyvinyl alcohol, a 50-inch VA liquid crystal display device manufactured according to FIGS. 2 to 9 of JP-A-2000-154261, JP-A-2000- The 50-inch OCB type liquid crystal display device manufactured according to FIGS. 10 to 15 of Japanese Patent No. 154261 and the IPS type liquid crystal display device shown in FIG. 11 of Japanese Patent Application Laid-Open No. 2004-12731 were used. Furthermore, when the low reflection film of this invention was stuck and evaluated on the outermost layer of these liquid crystal display devices, the favorable liquid crystal display element was obtained. In particular, the addition polymerization type cycloolefin resin film was good.

FIG. 1 is a schematic view showing conventional longitudinal stretching. FIG. 2 is a schematic view showing short span stretching. It is the schematic which shows the generation | occurrence | production state of the bowing by transverse stretching. (A) shows the case where preheating temperature = stretching temperature = heat setting temperature, and (b) shows the case where preheating temperature> stretching temperature> heat setting temperature.

Explanation of symbols

1 Nip roll 2 Heater 3 Film 4 Preheating roll

Claims (11)

A cycloolefin resin film containing 0.05 to 3% by mass of at least one ultraviolet absorber having a molecular weight of 500 or more and produced by a melt film forming method using a touch roll. 2. The cycloolefin resin film according to claim 1, wherein an absorbance at a wavelength of 380 nm is 5% or less. The cycloolefin resin film according to claim 1 or 2, wherein the ultraviolet absorber is a compound represented by the following general formula (HUV-1).
General formula (HUV-1)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or carbon number. Represents a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms. The cycloolefin resin film according to any one of claims 1 to 3, wherein the projected diagonal stripe is 10 lines / cm or less. The cycloolefin resin film according to any one of claims 1 to 4, wherein the cycloolefin resin is obtained by addition polymerization. A polarizing plate comprising at least one layer of the cycloolefin resin film according to any one of claims 1 to 5 laminated on a polarizing film. An optical compensation film using the cycloolefin resin film according to any one of claims 1 to 5 as a substrate. An antireflection film, wherein the cycloolefin resin film according to any one of claims 1 to 5 is used as a substrate. At least one of the cycloolefin resin film according to any one of claims 1 to 5, the polarizing plate according to claim 6, the optical compensation film according to claim 7, and the antireflection film according to claim 8. A liquid crystal display device characterized by using the above. A cycloolefin resin composition containing 0.05 to 3% by mass of at least one UV absorber having a molecular weight of 500 or more is produced by a melt film forming method using a touch roll. A method for producing a resin film. The said ultraviolet absorber is a compound represented by the following general formula (HUV-1), The manufacturing method of the cycloolefin resin film of Claim 10 characterized by the above-mentioned.
General formula (HUV-1)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or carbon number. Represents a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

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