JP2007009114A - Cyclic polyolefin film, method for producing the same, and optical compensation film, polarizing plate, polarizing plate protection film and liquid crystal display device produced by using the polyolefin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cyclic polyolefin film having low hygroscopicity and moisture permeability and excellent processability owing to high flexibility, a solution-casting method for producing a cyclic polyolefin film having small optical nonuniformity, an optical compensation film, a polarizing plate and a protection film for a polarizing film having low optical nonuniformity, and a liquid crystal display device produced by using the film, etc. <P>SOLUTION: The cyclic polyolefin film contains a cyclic polyolefin resin and at least one kind of compound selected from polyolefin compounds and polyethylene glycol compounds. The method for producing the cyclic polyolefin film contains a step to dissolve at least the cyclic polyolefin and at least one kind of compound selected from polyolefin compounds and polyethylene glycol compounds in a solvent, a step to cast the solution, a step to dry the cast film and a step to wind the dried film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical compensation film, a polarizing plate, a polarizing plate protective film, and a liquid crystal display device using them. In particular, it relates to a cyclic polyolefin film used for them.

  A polarizing plate is usually produced by laminating a film mainly composed of cellulose triacetate as a protective film on both sides of a polarizing film in which iodine or a dichroic dye is oriented and adsorbed on polyvinyl alcohol. Cellulose triacetate has characteristics such as toughness, flame retardancy, and high optical isotropy (low retardation value), and is widely used as the protective film for polarizing plates described above. The liquid crystal display device includes a polarizing plate and a liquid crystal cell. In a TN mode TFT liquid crystal display device which is currently the mainstream of liquid crystal display devices, an optical compensation film (retardation film) is inserted between the polarizing plate and the liquid crystal cell as described in JP-A-8-50206. As a result, a liquid crystal display device with high display quality is realized. However, the cellulose triacetate film has a large amount of moisture absorption and transmission, so that there are problems that the optical compensation performance is changed and the polarizer is easily deteriorated.

  Cyclic polyolefin film is attracting attention as a film that can improve the hygroscopicity and moisture permeability of cellulose triacetate film, and development of retardation film for polarizing plate protective film and liquid crystal display by hot melt film formation and solution film formation ( Patent Documents 1 to 4). However, cyclic polyolefins are generally bulky and have a rigid hydrocarbon skeleton, so they generally have mechanically fragile properties, are less flexible than cellulose acetate, and have bending stress and shear on the film. When stress is applied, the film tends to crack. Moreover, when processing as an optical film, a crack is easy to enter into a cutting part and it is easy to generate | occur | produce chips. The generated chips contaminated the optical film and caused optical defects. In order to improve this, adding a plasticizer is proposed (patent documents 5-6).

Conventionally, the addition of a plasticizer has a certain level of plastic effect, but generally the reason is not clear when it is manufactured by solution casting used in the production of optical films to obtain good flatness. However, there is a problem that unevenness of optical characteristics, which is thought to be caused by fluctuations in film forming conditions, is likely to occur, and image quality deteriorates when used in a liquid crystal display device.
JP 2003-212927 A JP 2004-126026 A Japanese Patent Laid-Open No. 2002-114827 International Publication WO2004 / 049011 Pamphlet JP 2000-17087 A JP-A-10-221501

  An object of the present invention is to provide a cyclic polyolefin film that has low hygroscopicity and moisture permeability, and at the same time has excellent processability due to excellent flexibility. Another object of the present invention is to provide a cyclic polyolefin film by solution casting with little optical unevenness. Furthermore, it is in providing the favorable optical compensation film with little optical nonuniformity, a polarizing plate, a polarizing plate protective film, and a liquid crystal display device using them.

  As a result of intensive studies, the present inventor has been able to solve the above problems by the following means.

(1) A cyclic polyolefin film comprising a cyclic polyolefin resin, and at least one compound selected from a polyolefin compound and a polyethylene glycol compound.
(2) The cyclic polyolefin film according to (1), wherein the compound is a compound having a molecular weight of 20000 or less.
(3) The cyclic polyolefin film according to (1) or (2), wherein the compound is a compound having an I / O value of 0.5 or less.

(4) At least one cyclic polyolefin resin and at least one compound selected from a polyolefin compound and a polyethylene glycol compound are dissolved in a solvent, casted, dried, and wound up. The manufacturing method of the cyclic polyolefin film characterized by these.
(5) The method for producing a cyclic polyolefin film according to (4), wherein stretching is performed after the casting step.

(6) A protective film for a polarizing plate comprising the cyclic polyolefin film according to any one of (1) to (3).
(7) An optical compensation film comprising the cyclic polyolefin film according to any one of (1) to (3).
(8) A polarizing plate comprising the polarizing plate protective film according to (6).
(9) The cyclic polyolefin film according to any one of (1) to (3), the protective film for a polarizing plate according to (6), the optical compensation film according to (7), and the polarized light according to (8) A liquid crystal display device comprising at least one of plates.

  By carrying out the present invention, it was possible to provide a cyclic polyolefin optical film that has low hygroscopicity and moisture permeability and at the same time has excellent processability due to excellent flexibility. Moreover, the cyclic polyolefin optical film with little optical nonuniformity was able to be produced by solution casting by implementing this invention. Furthermore, it was possible to provide a good optical compensation film with little optical unevenness, a polarizing plate, a polarizing plate protective film, and a liquid crystal display device using them.

Hereinafter, the present invention will be described in detail.
(Cyclic polyolefin resin)
In the present invention, the cyclic polyolefin resin represents a polymer resin having a cyclic polyolefin structure.
In the present invention, the cyclic polyolefin resin is also referred to as a cyclic polyolefin.
Examples of the polymer resin having a cyclic polyolefin structure used in the present invention include (1) a norbornene-based polymer, (2) a monocyclic olefin polymer, (3) a cyclic conjugated diene polymer, (4) There are vinyl alicyclic hydrocarbon polymers and hydrides of (1) to (4). Preferred polymers for the present invention are addition (co) polymer cyclic polyolefins containing at least one repeating unit represented by the following general formula (II) and, if necessary, repeating units represented by the general formula (I): An addition (co) polymer cyclic polyolefin further comprising at least one kind. Further, a ring-opening (co) polymer containing at least one cyclic repeating unit represented by the general formula (III) can also be suitably used.

In formula, m represents the integer of 0-4. R ^{1 to} R ⁶ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and X ^{1 to} X ³ and Y ^{1 to} Y ³ each independently represent a hydrogen atom or a carbon atom having 1 to 10 carbon atoms. hydrocarbon group, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms substituted with a halogen _{atom, - (CH 2) n COOR} 11, - (CH 2) n OCOR 12, - (CH 2) n NCO, - _{(CH 2) n NO 2,} - (CH 2) n CN, - (CH 2) n CONR 13 R 14, - (CH 2) n NR 13 R 14, - (CH 2) n OZ, - (CH 2 ) _n W, or (—CO) ₂ O, (—CO) ₂ NR ¹⁵ composed of X ¹ and Y ^1, X ² and Y ^2, or X ³ and Y ³ . R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and Z is a hydrocarbon group or a hydrocarbon group substituted with a halogen. W represents SiR ¹⁶ _p D _{3 -p} (R ¹⁶ represents a hydrocarbon group having 1 to 10 carbon atoms, D represents a halogen atom —OCOR ¹⁶ or —OR ¹⁶ , and p represents an integer of 0 to 3). , N represents an integer of 0-10.

By introducing a polarizable large functional group in a substituent ^{X 1 ~X 3, Y 1 ~Y} 3, by increasing the thickness-direction retardation of the optical film (Rth), in-plane retardation (Re) The expression can be increased. A film having a high Re developability can increase the Re value by stretching in the film forming process.
Norbornene-based addition (co) polymers are disclosed in JP-A No. 10-7732, JP-T 2002-504184, US2004229157A1, or WO2004 / 070463A1. It can be obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. If necessary, norbornene-based polycyclic unsaturated compounds and ethylene, propylene, butene; conjugated dienes such as butadiene and isoprene; nonconjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride It is also possible to carry out addition polymerization with linear diene compounds such as acid, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate and vinyl chloride. This norbornene-based addition (co) polymer is sold under the name of Apel by Mitsui Chemicals, Inc., and has different glass transition temperatures (Tg) such as APL8008T (Tg70 ° C), APL6013T (Tg125 ° C) or APL6015T ( Grades such as Tg145 ° C). Pellets such as TOPAS 8007, 6013 and 6015 are sold by Polyplastics Co., Ltd. Further, Appear 3000 is sold by Ferrania.

Norbornene-based polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19807, JP-A-2003-115767, or JP-A-2004-309979. As disclosed in No. 1, etc., the polycyclic unsaturated compound is made by addition polymerization or metathesis ring-opening polymerization and then hydrogenation. In the norbornene-based polymer used in the present invention, R ^{5 to} R ⁶ are preferably a hydrogen atom or —CH ₃ , X ³ and Y ³ are preferably a hydrogen atom, Cl, —COOCH ₃ , and other groups are appropriately selected. The This norbornene resin is sold under the trade name Arton G or Arton F by JSR Co., Ltd., and Zeonor ZF14, ZF16, Zeonex 250 or Zeonex 250 by Nippon Zeon Co., Ltd. They are commercially available under the trade name 280 and can be used.

(Polyolefin compounds, polyethylene glycol compounds)
The cyclic polyolefin film of the present invention is characterized by containing at least one compound selected from polyolefin-based compounds and polyethylene glycol-based compounds.
In the present invention, the polyolefin compound represents a polymer compound having a polyolefin structure, and the polyethylene glycol compound represents a polymer compound having an ether structure in the main chain.
The molecular weight of the polyolefin compound and the polyethylene glycol compound is preferably 20000 or less, more preferably 100 to 20000, more preferably 200 to 5000, and still more preferably 300 to 3000. If the molecular weight is too small, the physical properties deteriorate due to volatilization in the drying step or natural standing, and if the molecular weight is too large, the effect of improving the processability is reduced. In addition, the cyclic polyolefin is easily wrinkled during film formation or processing into a polarizing plate, and further, the optical characteristics change due to the stress that appears to occur at this time, and the optical characteristics are likely to be uneven. However, it has been found that optical unevenness during production can be remarkably improved by containing the compound of the present invention.

  The polyolefin compound and polyethylene glycol compound used in the present invention are preferably compounds having an I / O value of 0.5 or less. The I / O value is more preferably 0 to 0.4, still more preferably 0 to 0.3. By adding a compound having an I / O value of 0.5 or less, a plastic effect can be effectively realized. The I / O value used in the present invention is the inorganic (I) and organic (O) described in the organic conceptual diagram-basics and application-(Yoshio Koda, Sankyo Publishing, published May 10, 1984). It is a value calculated based on this, and is widely known as a value that marks the characteristics of a compound.

  Specific examples of the polyolefin compound and the polyethylene glycol compound include the following, but are not limited thereto. That is, paraffin waxes such as normal paraffin, isoparaffin, cycloparaffin (average molecular weight 330 to 600, melting point 45 to 80 ° C.), liquid paraffin (JIS standard K2231 ISOVG8, VG15, VG32, VG68, VG100, etc.), Paraffin pellets (melting point: 56 to 58 ° C, 58 to 60 ° C, 60 to 62 ° C, etc.), chlorinated paraffin, low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight polyisobutene, hydrogenated polybutadiene, hydrogenated polyisoprene, squalane, polyethylene glycol (Average molecular weight 200, 400, 600, 1000, 1500, 2000, 3000, 7500, 20000), polypropylene glycol (diol type, triol type, molecular weight 700, 1000, 2000, 300) Etc.) can be mentioned. Among these, compounds having an I / O value of 0 are preferable, and paraffin waxes, liquid paraffins, paraffin pellets, low molecular weight polyethylene, low molecular weight polypropylene, hydrogenated polyisoprene, and squalane can be suitably used. The compound may be added by any method in the cyclic polyolefin solution (dope) preparation step, but may be added by adding a step of adding this compound to the final preparation step of the dope preparation step. Moreover, when a cyclic polyolefin film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ.

  The content of the polyolefin compound and polyethylene glycol compound used in the present invention is preferably 0.5 to 30% by mass, more preferably 2 to 25% by mass, and still more preferably based on the cyclic polyolefin. Is 3-20 mass%. 30 mass% or less is preferable at the point which does not have the precipitation process at the time of film forming, or precipitation with the passage of time after film forming, and does not generate | occur | produce the undesirable phenomenon of contaminating the circumference. Moreover, 0.5 mass% or more is preferable at the point which can obtain desired performance in the uniformity of the optical characteristic at the time of film forming including a plastic effect.

(Method for producing cyclic polyolefin film)
Although the following method is mentioned as a manufacturing method of the cyclic polyolefin film of this invention, It is not limited to this.
That is, at least a cyclic polyolefin resin, and a step of dissolving at least one compound selected from a polyolefin compound and a polyethylene glycol compound in a solvent, a casting step, a drying step, and a drying and winding step It is a manufacturing method including.
When dissolving the cyclic polyolefin resin, the polyolefin compound and the polyethylene glycol compound are preferably soluble or dispersed in the following solvent.
Further, the polyolefin compound and the polyethylene glycol compound may be mixed with a cyclic polyolefin resin or the like to form a film without forming a solution.

(solvent)
Next, the solvent in which the cyclic polyolefin of the present invention is dissolved will be described. In the present invention, the solvent that can be used is not particularly limited as long as the object can be achieved as long as the cyclic polyolefin can be dissolved, cast, and formed into a film. The solvent used in the present invention is, for example, a solvent selected from a chlorinated solvent such as dichloromethane and chloroform, a chain hydrocarbon having 3 to 12 carbon atoms, a cyclic hydrocarbon, an aromatic hydrocarbon, an ester, a ketone, and an ether. preferable. Esters, ketones and ethers may have a cyclic structure. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane, decane, and the like. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include cyclopentane, cyclohexane and derivatives thereof. Examples of the aromatic hydrocarbon having 3 to 12 carbon atoms include benzene, toluene, xylene and the like. Examples of esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and methylcyclohexanone. Examples of ethers having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole. Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol. The preferred boiling point of the organic solvent is 35 ° C. or higher and 110 ° C. or lower. The solvent used in the present invention can be used by mixing two or more solvents for adjusting the solution properties such as drying property and viscosity. Further, as long as the cyclic polyolefin is dissolved in the mixed solvent, the solvent is poor. It is also possible to add.

  A preferred poor solvent can be appropriately selected depending on the type of polymer used. When a chlorinated organic solvent is used as the good solvent, alcohols can be preferably used. The alcohols may preferably be linear, branched or cyclic, and among them, saturated aliphatic hydrocarbons are preferable. The hydroxyl group of the alcohol may be any of primary to tertiary. As the alcohol, fluorine-based alcohol is also used. Examples thereof include 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like. Among the poor solvents, monohydric alcohols have a peeling resistance reducing effect and can be preferably used. Particularly preferred alcohols vary depending on the good solvent to be selected, but considering the drying load, alcohols having a boiling point of 120 ° C. or lower are preferred, monohydric alcohols having 1 to 6 carbon atoms are more preferred, and those having 1 to 4 carbon atoms are preferred. Alcohols can be used particularly preferably. A particularly preferable mixed solvent for preparing the cyclic polyolefin solution is a combination in which dichloromethane is the main solvent and one or more alcohols selected from methanol, ethanol, propanol, isopropanol, or butanol are used as a poor solvent.

(Additive)
In the cyclic polyolefin solution of the present invention, various additives (for example, deterioration inhibitors, UV inhibitors, retardation (optical anisotropy) modifiers, fine particles, peeling accelerators, red, etc.) according to the application in each preparation step. External absorbents, etc.) can be added and they can be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of an ultraviolet absorbing material at 20 ° C. or lower and 20 ° C. or higher, and a mixture of deterioration preventing agents are also possible. Furthermore, infrared absorbing dyes are described, for example, in JP-A No. 2001-194522. Moreover, the addition time may be added at any time in the cyclic polyolefin solution (dope) preparation step, but may be added by adding an additive to the final preparation step of the dope preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when a cyclic polyolefin film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ.

(Deterioration inhibitor)
The cyclic polyolefin solution of the present invention contains known degradation (oxidation) inhibitors such as 2,6-di-t-butyl, 4-methylphenol, 4,4′-thiobis- (6-t-butyl-3- Methylphenol), 1,1′-bis (4-hydroxyphenyl) cyclohexane, 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, pentaerythrityl -Phenolic or hydroquinone antioxidants such as tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate can be added. Further, tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t It is preferable to use a phosphorus-based antioxidant such as -butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite. The added amount of the antioxidant is 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the cyclic polyolefin.

(UV absorber)
In the cyclic polyolefin solution of the present invention, an ultraviolet absorber is preferably used from the viewpoint of preventing deterioration of a polarizing plate or liquid crystal. As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Specific examples of UV absorbers preferably used in the present invention include, for example, hindered phenol compounds, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds Etc. Examples of hindered phenol compounds include 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert -Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate and the like. Examples of benzotriazole compounds include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5- Triazine, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4- Hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) -5 -Chlorbenzotriazole, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the like. The addition amount of these ultraviolet light inhibitors is preferably 1 ppm to 1.0% by mass with respect to the cyclic polyolefin, more preferably 10 to 1000 ppm.

(Fine particles)
In the present invention, when the produced cyclic polyolefin film is handled, it is preferable to add fine particles in order to prevent scratches or deterioration of transportability. Preferred specific examples of the fine particles include inorganic compounds such as silicon-containing compounds, silicon dioxide, titanium oxide, zinc oxide, aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin oxide / antimony oxide, Calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate and the like are preferred, more preferably inorganic compounds and metal oxides containing silicon, Since the turbidity of the film can be reduced, silicon dioxide is particularly preferably used. As the silicon dioxide fine particles, for example, commercially available products having trade names such as Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. As the fine particles of zirconium oxide, for example, those commercially available under trade names such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.

The primary average particle diameter of these fine particles is preferably from the viewpoint of keeping the haze low. It is 001-20 micrometers, More preferably, it is 0.001-10 micrometers, More preferably, it is 0.00. 002 to 1 μm, and particularly preferably 0.005 to 0. 5 μm. The measurement of the primary average particle diameter of the fine particles is obtained by the average particle diameter of the particles with a transmission electron microscope. The purchased fine particles are often agglomerated and are preferably dispersed by a known method before use. The secondary particle diameter is preferably 0.2 to 1.5 μm by dispersion, and more preferably 0.3 to 1.0 μm. The amount of fine particles added is preferably 0.01 to 0.3 parts by weight, more preferably 0.05 to 0.2 parts by weight, and most preferably 0.08 to 0.12 parts by weight with respect to 100 parts by weight of the cyclic polyolefin. .
The preferable haze range of the cyclic polyolefin film to which fine particles are added is 2.0% or less, more preferably 1.2% or less, and particularly preferably 0.5% or less. In order to reduce the haze, the added fine particles are sufficiently dispersed to reduce the number of aggregated particles, or the fine particles are used only in the skin layer in order to reduce the addition amount. A preferable dynamic friction coefficient of the cyclic polyolefin film to which fine particles are added is 0.8 or less, and 0.5 or less is particularly preferable. The dynamic friction coefficient can be measured using a steel ball in accordance with a method specified by JIS or ASTM. The haze can be measured using a 1001DP type haze meter manufactured by Nippon Denshoku Industries Co., Ltd.

(Peeling accelerator)
As additives for reducing the peeling resistance of the cyclic polyolefin film, many surfactants having a remarkable effect are found. As preferred release agents, phosphate ester surfactants, carboxylic acid or carboxylate surfactants, sulfonic acid or sulfonate surfactants, and sulfate ester surfactants are effective. A fluorine-based surfactant in which part of the hydrogen atoms bonded to the hydrocarbon chain of the surfactant is substituted with fluorine atoms is also effective. The release agent is exemplified below.

RZ-1 C ₈ H ₁₇ O—P (═O) — (OH) ₂
RZ-2 C ₁₂ H ₂₅ O—P (═O) — (OK) ₂
RZ-3 C ₁₂ H ₂₅ OCH ₂ CH ₂ O—P (═O) — (OK) ₂
RZ-4 C ₁₅ H ₃₁ (OCH ₂ CH ₂ ) ₅ O—P (═O) — (OK) _{2
RZ-5 {C 12 H 25} O (CH 2 CH 2 O) 5} 2 -P (= O) -OH
_{RZ-6 {C 18 H 35} (OCH 2 CH 2) 8 O} 2 -P (= O) -ONH 4
_{RZ-7 (t-C 4} H 9) 3 -C 6 H 2 -OCH 2 CH 2 O-P (= O) - (OK) 2
_{RZ-8 (iso-C 9} H 19 -C 6 H 4 -O- (CH 2 CH 2 O) 5 -P (= O) - (OK) (OH)
RZ-9 C ₁₂ H ₂₅ SO ₃ Na
RZ-10 C ₁₂ H ₂₅ OSO ₃ Na
RZ-11 C ₁₇ H ₃₃ COOH
RZ-12 C ₁₇ H ₃₃ COOH · N (CH ₂ CH ₂ OH) _{3
RZ-13 iso-C 8 H} 17 -C 6 H 4 -O- (CH 2 CH 2 O) 3 - (CH 2) 2 SO 3 Na
_{RZ-14 (iso-C 9} H 19) 2 -C 6 H 3 -O- (CH 2 CH 2 O) 3 - (CH 2) 4 SO 3 Na
RZ-15 sodium triisopropyl naphthalene sulfonate RZ-16 sodium tri-t-butyl naphthalene sulfonate RZ-17 C ₁₇ H ₃₃ CON (CH ₃ ) CH ₂ CH ₂ SO ₃ Na
RZ-18 C ₁₂ H ₂₅ -C ₆ H ₄ SO ₃ .NH ₄

  The addition amount of the release agent is preferably 0.05 to 5% by mass, more preferably 0.1 to 2% by mass, and most preferably 0.1 to 0.5% by mass with respect to the cyclic polyolefin.

(Retardation expression agent)
In the present invention, since a retardation value is expressed, a compound having at least two aromatic rings can be used as a retardation developer. When using a retardation enhancer, it is preferably used in the range of 0.05 to 20 parts by mass, more preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymer. , More preferably 0.2 to 5 parts by mass, and most preferably 0.5 to 2 parts by mass. Two or more retardation developing agents may be used in combination.
The retardation developer preferably has a maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

In the present specification, the “aromatic ring” includes an aromatic hetero ring in addition to an 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 the hetero atom, 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.
As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable, In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, compounds disclosed in JP-A No. 2001-166144 are preferably used.

The number of aromatic rings contained in the retardation developer is preferably 2 to 20, more preferably 2 to 12, still more preferably 2 to 8, and most preferably 2 to 6. preferable.
The bond relationship between two aromatic rings can be classified into (a) a condensed ring, (b) a direct bond with a single bond, and (c) a bond through a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c).

Examples of the condensed ring (a condensed ring of two or more aromatic rings) include an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, an acenaphthylene ring, a biphenylene ring, a naphthacene ring, Pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline Ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring and thiant It includes emissions ring. Naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred.
The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded with two or more single bonds to form an aliphatic ring or a non-aromatic heterocyclic ring between the two aromatic rings.

The linking group in (c) is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenylene group, an alkynylene group, —CO—, —O—, —NH—, —S—, or a combination thereof. Examples of linking groups composed of combinations are shown below. In addition, the relationship between the left and right in the following examples of the linking group may be reversed.
c1: -CO-O-
c2: —CO—NH—
c3: -alkylene-O-
c4: —NH—CO—NH—
c5: —NH—CO—O—
c6: —O—CO—O—
c7: -O-alkylene-O-
c8: -CO-alkenylene-
c9: -CO-alkenylene-NH-
c10: -CO-alkenylene-O-
c11: -alkylene-CO-O-alkylene-O-CO-alkylene-
c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-
c13: -O-CO-alkylene-CO-O-
c14: -NH-CO-alkenylene-
c15: -O-CO-alkenylene-

The aromatic ring and the linking group may have a substituent.
Examples of the substituent include halogen atom (F, Cl, Br, I), hydroxyl, carboxyl, cyano, amino, nitro, sulfo, carbamoyl, sulfamoyl, ureido, alkyl group, alkenyl group, alkynyl group, aliphatic acyl group , Aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group, aliphatic substituted carbamoyl group, aliphatic Substituted sulfamoyl groups, aliphatic substituted ureido groups and non-aromatic heterocyclic groups are included.
The alkyl group preferably has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is particularly preferable. The alkyl group may further have a substituent (eg, hydroxy, carboxy, alkoxy group, alkyl-substituted amino group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl and 2-diethylaminoethyl.

The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is particularly preferable. The alkenyl group may further have a substituent. Examples of alkenyl groups include vinyl, allyl and 1-hexenyl.
The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is particularly preferable. The alkynyl group may further have a substituent. Examples of alkynyl groups include ethynyl, 1-butynyl and 1-hexynyl.

The aliphatic acyl group preferably has 1 to 10 carbon atoms. Examples of the aliphatic acyl group include acetyl, propanoyl and butanoyl.
The aliphatic acyloxy group preferably has 1 to 10 carbon atoms. Examples of the aliphatic acyloxy group include acetoxy.
The number of carbon atoms of the alkoxy group is preferably 1 to 8. The alkoxy group may further have a substituent (eg, alkoxy group). Examples of alkoxy groups (including substituted alkoxy groups) include methoxy, ethoxy, butoxy and methoxyethoxy.
The alkoxycarbonyl group preferably has 2 to 10 carbon atoms. Examples of the alkoxycarbonyl group include methoxycarbonyl and ethoxycarbonyl.
The number of carbon atoms of the alkoxycarbonylamino group is preferably 2 to 10. Examples of the alkoxycarbonylamino group include methoxycarbonylamino and ethoxycarbonylamino.

The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include methylthio, ethylthio and octylthio.
The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include methanesulfonyl and ethanesulfonyl.
The aliphatic amide group preferably has 1 to 10 carbon atoms. Examples of the aliphatic amide group include acetamide.
The aliphatic sulfonamide group preferably has 1 to 8 carbon atoms. Examples of the aliphatic sulfonamido group include methanesulfonamido, butanesulfonamido and n-octanesulfonamido.
The number of carbon atoms of the aliphatic substituted amino group is preferably 1 to 10. Examples of the aliphatic substituted amino group include dimethylamino, diethylamino and 2-carboxyethylamino.

The aliphatic substituted carbamoyl group preferably has 2 to 10 carbon atoms. Examples of the aliphatic substituted carbamoyl group include methylcarbamoyl and diethylcarbamoyl.
The aliphatic substituted sulfamoyl group preferably has 1 to 8 carbon atoms. Examples of the aliphatic substituted sulfamoyl group include methylsulfamoyl and diethylsulfamoyl.
The number of carbon atoms in the aliphatic substituted ureido group is preferably 2 to 10. Examples of the aliphatic substituted ureido group include methylureido.
Examples of non-aromatic heterocyclic groups include piperidino and morpholino.
The molecular weight of the retardation developer is preferably 300 to 800.

  In the present invention, a rod-shaped compound having a linear molecular structure can be preferably used in addition to a compound using a 1,3,5-triazine ring. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation can be performed using molecular orbital calculation software (eg, WinMOPAC2000, manufactured by Fujitsu Limited) to obtain a molecular structure that minimizes the heat of formation of a compound. The molecular structure being linear means that in the thermodynamically most stable structure obtained by calculation as described above, the angle of the main chain constituting the molecular structure is 140 degrees or more.

As the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (V) is preferable.
Formula (V): Ar ¹ -L ¹ -Ar ²

In the general formula (V), Ar ¹ and Ar ² are each independently an aromatic group.
In the present specification, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group.
An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group. The heterocycle of the aromatic heterocyclic group is generally unsaturated. 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, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable.
As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

In the general formula (V), L ¹ is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO—, and a combination thereof. The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group.
The alkylene group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, more preferably 1 to 10, still more preferably 1 to 8, and most preferably 1 to 6. It is.

The alkenylene group and alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure.
The number of carbon atoms of the alkenylene group and the alkynylene group is preferably 2 to 10, more preferably 2 to 8, further preferably 2 to 6, further preferably 2 to 4, and most preferably 2. (Vinylene or ethynylene).
The arylene group preferably has 6 to 20 carbon atoms, more preferably 6 to 16, and still more preferably 6 to 12.
In the molecular structure of the general formula (V), the angle formed by Ar ¹ and Ar ² across L ¹ is preferably 140 degrees or more.
As the rod-like compound, a compound represented by the following formula (VI) is more preferable.
Formula (VI): Ar ¹ -L ² -XL ³ -Ar ²
In the general formula (VI), Ar ¹ and Ar ² are each independently an aromatic group. The definition and examples of the aromatic group are the same as those of Ar ¹ and Ar ^{2 in} the general formula (V).

In the general formula (VI), L ² and L ³ are each independently a divalent linking group selected from an alkylene group, —O—, —CO— and a group consisting of a combination thereof.
The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure.
The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and 1 or 2 (methylene or Most preferred is ethylene). L ² and L ³ are particularly preferably —O—CO— or —CO—O—. In the general formula (VI), X is 1,4-cyclohexylene, vinylene or ethynylene. Two or more rod-shaped compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination. The addition amount of the retardation enhancer is preferably 0.1 to 30% by mass, more preferably 0.5 to 20% by mass, based on the amount of cyclic polyolefin.

(Dope preparation)
Next, for the preparation of the cyclic polyolefin solution (dope) of the present invention, the method of stirring and dissolving at room temperature, the polymer was swollen by stirring at room temperature, cooled to -20 to -100 ° C, and heated again to 20 to 100 ° C. There are a cooling dissolution method in which the solvent is dissolved, a high temperature dissolution method in which the temperature is higher than the boiling point of the main solvent in a closed container, and a method in which the solvent is dissolved at a high temperature and a high pressure up to the critical point of the solvent. A polymer having good solubility is preferably dissolved at room temperature, but a polymer having poor solubility is dissolved by heating in a closed container. When dichloromethane is selected as the main solvent, many cyclic polyolefins can be dissolved by heating at 20 to 100 ° C.

  The viscosity of the cyclic polyolefin solution of the present invention is preferably in the range of 1 to 500 Pa · s at 25 ° C. More preferably, it is the range of 5-200 Pa.s. The viscosity was measured as follows. 1 mL of the sample solution was measured with a rheometer (CLS 500) using a Steel Cone having a diameter of 4 cm / 2 ° (both manufactured by TA Instruments). Measurement was started after the sample solution was kept warm at the measurement start temperature until the liquid temperature became constant.

  Furthermore, in order to make it easy to melt | dissolve, after making it melt | dissolve at a low density | concentration, you may concentrate using a concentration means. The concentration method is not particularly limited. For example, the low-concentration solution is guided between the cylindrical body and the rotation trajectory of the outer periphery of the rotating blade rotating in the circumferential direction, and the temperature between the solution and the solution. A method of obtaining a high-concentration solution while evaporating the solvent by giving a difference (for example, Japanese Patent Laid-Open No. 4-259511), blowing a heated low-concentration solution into the container from the nozzle, and until the solution hits the inner wall of the container from the nozzle In which the solvent is flash evaporated and the solvent vapor is withdrawn from the container and the concentrated solution is withdrawn from the bottom of the container (eg, US Pat. No. 2,541,012, US Pat. No. 2,858,229, US Pat. No. 4,414,341, US Pat. No. 4,504,355, etc.).

Prior to casting, it is preferable to filter off foreign matters such as undissolved matter, dust, and impurities using a suitable filter medium such as a wire mesh or flannel. For the filtration of the cyclic polyolefin solution, a filter having an absolute filtration accuracy of 0.1 to 100 μm is used, and a filter having an absolute filtration accuracy of 0.5 to 25 μm is preferably used. The thickness of the filter is preferably 0.1 to 10 mm, and more preferably 0.2 to 2 mm. In that case, the filtration pressure is preferably 1.6 MPa or less, more preferably 1.3 MPa or less, further 1.0 MPa or less, and particularly preferably 0.6 MPa or less. As the filter medium, conventionally known materials such as glass fibers, cellulose fibers, filter paper, and fluororesins such as tetrafluoroethylene resin can be preferably used, and ceramics and metals are also preferably used.
The viscosity of the cyclic polyolefin solution immediately before film formation is not particularly limited as long as it can be cast during film formation, and is usually adjusted to a range of 5 Pa · s to 1000 Pa · s, preferably 15 Pa · s to 500 Pa · s. s is more preferable, and 30 Pa · s to 200 Pa · s is still more preferable. In addition, although the temperature at this time will not be specifically limited if it is the temperature at the time of the casting, Preferably it is -5-70 degreeC, More preferably, it is -5-35 degreeC.

(Film formation)
A method for producing a film using a cyclic polyolefin solution will be described. For the method and equipment for producing the cyclic polyolefin film of the present invention, the same solution casting method and solution casting apparatus as those conventionally used for producing cellulose triacetate films are preferably used. In this method, the following method is generally adopted.
The dope (cyclic polyolefin solution) prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation. The dope is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the number of rotations, and the dope is run endlessly from the die (slit) of the pressure die. The dry-dried dope film (also referred to as web) is peeled off from the metal support at a peeling point that is uniformly cast on the metal support and substantially rounds the metal support. Clip the ends of the resulting web with clips,
It is transported by a tenter and dried, and then transported by a roll group of a drying device to finish drying, and is wound up to a predetermined length by a winder. The combination of the tenter and the roll group dryer varies depending on the purpose. In the solution casting film forming method used for the functional protective film for electronic displays, in addition to the solution casting film forming apparatus, surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. Therefore, a coating device is often added. Although each manufacturing process is described briefly below, it is not limited to these.

First, the prepared cyclic polyolefin solution (dope) is cast on an endless metal support such as a metal drum or metal support (band or belt) when a cyclic polyolefin film is produced by the solvent cast method. The film is preferably formed by evaporating the solvent. The dope before casting is preferably adjusted in concentration so that the amount of cyclic polyolefin is 10 to 35 mass%. The surface of the drum or band is preferably finished in a mirror state. The dope is preferably cast on a drum or band having a surface temperature of 30 ° C. or lower, and particularly preferably a metal support temperature of −10 to 20 ° C.
Further, JP 2000-301555, JP 2000-301558, JP 7-032391, JP 3-193316, JP 5-086212, JP 62-037113, JP 2-276607. The cellulose acylate film-forming techniques described in JP-A-55-014201, JP-A-2-111511 and JP-A-2-208650 can be applied in the present invention.

(Multilayer casting)
The cyclic polyolefin solution may be cast as a single layer liquid on a smooth band or drum as a metal support, or a plurality of cyclic polyolefin liquids of two or more layers may be cast.
When casting a plurality of cyclic polyolefin solutions, a film may be produced while casting and laminating a solution containing a cyclic polyolefin from a plurality of casting ports provided at intervals in the traveling direction of the metal support. For example, the methods described in, for example, JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be applied.
Further, it may be formed into a film by casting a cyclic polyolefin solution from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245, This can be carried out by the methods described in JP-A Nos. 61-104813, 61-158413, and 6-134933. Also, a cyclic polyolefin film casting method described in Japanese Patent Application Laid-Open No. 56-162617 wraps a flow of a high-viscosity cyclic polyolefin solution with a low-viscosity cyclic polyolefin solution and simultaneously extrudes the high- and low-viscosity cyclic polyolefin solution. Good. Furthermore, it is also a preferred embodiment that the outer solution described in JP-A-61-94724 and JP-A-61-94725 contains a larger amount of an alcohol component which is a poor solvent than the inner solution. Alternatively, the film is formed by peeling the film formed on the metal support using the first casting port and performing the second casting on the side in contact with the metal support surface using the two casting ports. For example, it is a method described in Japanese Patent Publication No. 44-20235. The cyclic polyolefin solution to be cast may be the same solution or different cyclic polyolefin solutions, and is not particularly limited. In order to give a function to a plurality of cyclic polyolefin layers, a cyclic polyolefin solution corresponding to the function may be extruded from each casting port. Further, the cyclic polyolefin solution may be cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorption layer, and a polarizing layer).

In the case of a single-layer solution, it is necessary to extrude a high-concentration and high-viscosity cyclic polyolefin solution in order to obtain the required film thickness. In this case, the cyclic polyolefin solution is not stable and solids are generated. It tends to cause problems due to failure or poor flatness. As a solution to this problem, by casting a plurality of cyclic polyolefin solutions from the casting port, it is possible to extrude a highly viscous solution onto a metal support at the same time. Not only can this be achieved, but a reduction in drying load can be achieved by using a concentrated cyclic polyolefin solution, and the production speed of the film can be increased.
In the case of co-casting, the inner and outer thicknesses are not particularly limited, but preferably the outer side is preferably 1 to 50% of the total film thickness, and more preferably 2 to 30%. Here, in the case of co-casting with three or more layers, the total thickness of the layer in contact with the metal support and the layer in contact with the air side is defined as the outer thickness. In the case of co-casting, a cyclic polyolefin film having a laminated structure can be produced by co-casting the aforementioned cyclic polyolefin solutions having different additive concentrations such as a deterioration inhibitor, an ultraviolet absorber and fine particles. For example, a cyclic polyolefin film having a structure of skin layer / core layer / skin layer can be produced. For example, the fine particles can be contained in the skin layer in a large amount or only in the skin layer. The deterioration inhibitor and the ultraviolet absorber can be contained in the core layer more than the skin layer, and may be contained only in the core layer. It is also possible to change the type of deterioration preventing agent and ultraviolet absorber between the core layer and the skin layer. For example, the skin layer may contain a low-volatile deterioration preventing agent and / or an ultraviolet absorber so that the core layer is made plastic. It is also possible to add an excellent plasticizer or an ultraviolet absorber excellent in ultraviolet absorption. Moreover, it is also a preferable aspect to contain a peeling accelerator only in the skin layer on the metal support side. Moreover, in order to cool a metal support body by a cooling drum method and to gelatinize a solution, it is also preferable to add more alcohol which is a poor solvent to a skin layer than a core layer. The Tg of the skin layer and the core layer may be different, and the Tg of the core layer is preferably lower than the Tg of the skin layer. Further, the viscosity of the solution containing the cyclic polyolefin at the time of casting may be different between the skin layer and the core layer, and the viscosity of the skin layer is preferably smaller than the viscosity of the core layer. It may be smaller than the viscosity.

(Casting)
As a solution casting method, a method in which the prepared dope is uniformly extruded from a pressure die onto a metal support, and a method using a doctor blade in which the film thickness of the dope once cast on the metal support is adjusted with a blade. Alternatively, there is a method using a reverse roll coater that adjusts with a reverse rotating roll, but a method using a pressure die is preferable. The pressure die includes a coat hanger type and a T die type, and any of them can be preferably used. In addition to the methods listed here, it can be carried out by various methods of casting a cellulose triacetate solution known in the art, and by setting each condition in consideration of differences in the boiling point of the solvent used, etc. The same effects as described in the above publication can be obtained. The endlessly running metal support used for producing the cyclic polyolefin film of the present invention includes a drum whose surface is mirror-finished by chrome plating and a stainless steel belt whose surface is mirror-finished by surface polishing (even a band). Good) is used. The pressure die used for the production of the cyclic polyolefin film of the present invention may be one or two or more installed above the metal support. Preferably 1 or 2 groups. When two or more are installed, the dope amount to be cast may be divided into various ratios for each die, or the dope may be fed to the dies from each of a plurality of precision quantitative gear pumps. The temperature of the cyclic polyolefin solution used for casting is preferably −10 to 55 ° C., more preferably 25 to 50 ° C. In that case, all of the processes may be the same, or may be different at various points in the process. If they are different, the temperature may be a desired temperature just before casting.

(Dry)
The drying of the dope on the metal support involved in the production of the cyclic polyolefin film is generally a method of applying hot air from the surface side of the metal support (for example, drum or band), that is, the surface of the web on the metal support, A method of applying hot air from the back of the drum or band, contacting the temperature-controlled liquid from the back of the band or drum opposite the dope casting surface, and heating the drum or band by heat transfer to control the surface temperature Although there is a heat transfer method, the back surface liquid heat transfer method is preferable. The surface temperature of the metal support before casting may be any number as long as it is not higher than the boiling point of the solvent used for the dope. However, to accelerate drying and to lose fluidity on the metal support, the temperature should be set to 1 to 10 degrees below the boiling point of the lowest boiling solvent used. Is preferred. This is not the case when the casting dope is cooled and peeled off without drying.

(Peeling)
When peeling a dry film from a metal support, if the peeling resistance (peeling load) is large, the film is irregularly stretched in the film forming direction, resulting in uneven optical anisotropy. In particular, when the peeling load is large, a portion stretched stepwise in the film forming direction and a portion unstretched are alternately generated, resulting in a distribution in retardation. When loaded in a liquid crystal display device, the line or strip becomes uneven. In order not to cause such a problem, it is preferable that the peeling load of the film is 0.25 N or less per 1 cm of the film peeling width. The peeling load is more preferably 0.2 N / cm or less, further preferably 0.15 N or less, and particularly preferably 0.10 N or less. When the peeling load is 0.2 N / cm or less, even in a liquid crystal display device in which unevenness is likely to appear, no unevenness due to peeling is observed at all, which is particularly preferable. As a method of reducing the peeling load, there are a method of adding a release agent as described above and a method of selecting a solvent composition to be used.
The peel load is measured as follows. A dope is dropped on a metal plate having the same material and surface roughness as the metal support of the film forming apparatus, spread to a uniform thickness using a doctor blade, and dried. Cut the film with a cutter knife with a uniform width, peel off the tip of the film by hand and pinch it with a clip connected to the strain gauge, and measure the load change while pulling up the strain gauge in an oblique 45 degree direction. The volatile content in the peeled film is also measured. The same measurement is performed several times by changing the drying time, and the peeling load at the same time as the residual volatile content at the peeling in the actual film forming process is determined. As the peeling speed increases, the peeling load tends to increase, and it is preferable to measure at a peeling speed close to the actual peeling speed.
The preferable residual volatile content concentration at the time of peeling is 5 to 60% by mass. 10-50 mass% is still more preferable, and 20-40 mass% is especially preferable. Peeling with a high volatile content is preferable because the drying rate can be increased and the productivity is improved. On the other hand, when the volatile content is high, the strength and elasticity of the film are small, and the film is cut or stretched against the peeling force. Further, the self-holding force after peeling is poor, and deformation, wrinkles and nicks are likely to occur. It also causes distribution in the retardation.

(Extension process)
When the cyclic polyolefin film of the present invention is stretched, it is preferably carried out in a state where the solvent still remains in the film immediately after peeling. The purpose of stretching is (1) to obtain a film having excellent flatness without wrinkles and deformation, and (2) to increase the in-plane retardation of the film. When stretching is performed for the purpose of (1), stretching is performed at a relatively high temperature, and stretching is performed at a low magnification from 1% to 10% at most. A stretch of 2 to 5% is particularly preferred. When stretching for the purposes of both (1) and (2) or only for the purpose of (2), stretching is performed at a relatively low temperature and a stretching ratio of 2 to 150%.

If the film is stretched when the residual solvent remains in the film, it can be stretched at a lower temperature than the dry film. Many cyclic polyolefins have a high glass transition point (Tg), but can be stretched at a temperature lower than the inherent Tg of the polymer.
The stretching of the film may be uniaxial stretching only in the longitudinal or lateral direction, or may be simultaneous or sequential biaxial stretching. The birefringence of the retardation film for a VA liquid crystal cell or OCB liquid crystal cell is preferably such that the refractive index in the width direction is larger than the refractive index in the length direction. Therefore, it is preferable to stretch more in the width direction.

(After drying and winding)
It is preferable that the cyclic polyolefin film is further dried after stretching and wound up with a residual volatile content of 2% or less. It is preferable to knurle both ends of the film before winding. The width of the knurling is preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and the height is preferably 0.5 to 500 μm, more preferably 1 to 200 μm. This may be a single push or a double push.

The thickness of the finished (after drying) cyclic polyolefin film of the present invention varies depending on the purpose of use, but is usually in the range of 5 to 500 μm, preferably in the range of 30 to 150 μm, especially for liquid crystal display devices, 40 to 110 μm It is preferable that
The film thickness may be adjusted by adjusting the solid content concentration contained in the dope, the slit gap of the die base, the extrusion pressure from the die, the metal support speed, and the like so as to obtain a desired thickness. The width of the cyclic polyolefin film obtained as described above is preferably 0.5 to 3 m, more preferably 0.6 to 2.5 m, and still more preferably 0.8 to 2.2 m. The width of the film is preferably 0.5 m or more from the viewpoint of productivity, and is preferably 3 m or less from the viewpoint of web handling properties, optical uniformity of the film, and undesirable phenomena such as twisting and streaking on the film. The length is preferably 100 to 10,000 m per roll, more preferably 500 to 7000 m, and still more preferably 1000 to 6000 m. The film length is preferably less than 100 m from the viewpoint of productivity with less frequent roll replacement, and is preferably 10,000 m or less in terms of web handling, optical uniformity of the film, and the occurrence of undesirable phenomena such as twisting and streaking on the film. preferable. When winding, it is preferable to give a knurling to at least one end, the width is preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and the height is preferably 0.5 to 500 μm, more preferably 1 to 200 μm. is there. This may be a single push or a double push.

(Optical characteristics of cyclic polyolefin film)
The preferred optical properties of the cyclic polyolefin film of the present invention vary depending on the application of the film. In the case of a polarizing plate protective film, the in-plane retardation (Re) is preferably 5 nm or less, more preferably 3 nm or less. The thickness direction retardation (Rth) is preferably 50 nm or less, more preferably 35 nm or less, and particularly preferably 10 nm or less. When a cyclic polyolefin film is used as a retardation film, the range of Re and Rth varies depending on the type of retardation film, and there are various needs. As Re, 0 nm to 100 nm can be used, and as Rth, 0 nm to 400 nm can be used. The variation in the Re value over the entire width is preferably ± 5 nm, and more preferably ± 3 nm. Further, the variation of the Rth value is preferably ± 10 nm, and more preferably ± 5 nm. Further, it is preferable that the variation in the Re value and the Rth value in the length direction is also within the range of the variation in the width direction. In order to adjust the retardation value, it is possible to adjust not only the main chain molecular structure but also a substituent having a high polarizability in an appropriate ratio in the molecule. In addition, process conditions such as drying speed during film formation, temperature during stretching, residual solvent, stretching ratio, and the like can also be used as means for obtaining a desired retardation value. Re is KOBRA
In 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.), light having a specific wavelength λ can be incident in the normal direction of the film for measurement. Rth is Re, the retardation value measured by making light of wavelength λ nm incident from the direction inclined + 40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis, and the in-plane slow phase Abbe refractometer based on the retardation values measured in three directions, the retardation value measured by making light of wavelength λ nm incident from the direction inclined −40 ° with respect to the film normal direction with the axis as the tilt axis It can be calculated by inputting the assumed value of the average refractive index and the film thickness measured in (1). Here, the measurement wavelength λ is 590 nm.

(Polarizer)
The polarizing plate usually has a polarizer and two transparent protective films disposed on both sides thereof. The cyclic polyolefin film of the present invention can be used as both or one protective film. For the other protective film, a normal cellulose acetate film or the like may be used. Examples of the polarizer include an iodine polarizer, a dye polarizer using a dichroic dye, and a polyene polarizer. The iodine polarizer and the dye polarizer are generally produced using a polyvinyl alcohol film. When the cyclic polyolefin film of the present invention is used as a polarizing plate protective film, the film is preferably subjected to a surface treatment as described later, and then the film-treated surface and a polarizer are preferably bonded using an adhesive. Examples of the adhesive used include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, vinyl latexes such as butyl acrylate, and gelatin. The polarizing plate is composed of a polarizer and a protective film that protects both surfaces of the polarizer, and further comprises a protective film bonded to one surface of the polarizing plate and a separate film bonded to the other surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the contact bonding layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.

The method of laminating the cyclic polyolefin film of the present invention to the polarizer is preferably performed so that the transmission axis of the polarizer coincides with the slow axis of the cyclic polyolefin film of the present invention. In addition, when the polarizing plate produced under polarizing plate crossed Nicols was evaluated, the orthogonality accuracy between the slow axis of the cyclic polyolefin film of the present invention and the absorption axis of the polarizer (axis orthogonal to the transmission axis) was 1 °. When it was larger, it was found that the polarization degree performance under the polarizing plate crossed Nicols was lowered and light leakage occurred. In this case, when combined with a liquid crystal cell, sufficient black level and contrast cannot be obtained. Therefore, the deviation between the direction of the main refractive index nx of the cyclic polyolefin film of the present invention and the direction of the transmission axis of the polarizing plate is preferably within 1 °, preferably within 0.5 °.
UV3100PC (manufactured by Shimadzu Corporation) can be used to measure the single plate transmittance TT, parallel transmittance PT, and orthogonal transmittance CT of the polarizing plate. In the measurement, measurement is performed in the range of 380 nm to 780 nm, and the average value of 10 measurements can be used for both single plate, parallel and orthogonal transmittance.
The polarizing plate durability test can be performed as follows in two types of forms in which (1) only the polarizing plate and (2) the polarizing plate are attached to glass via an adhesive. For the measurement of only the polarizing plate, two orthogonal and the same ones are prepared and measured so that an optical compensation film is sandwiched between two polarizers. Two samples (approx. 5 cm × 5 cm) are prepared by attaching a polarizing plate on a glass so that the optical compensation film is on the glass side. In single-plate transmittance measurement, the sample is set with the film side facing the light source. Each of the two samples is measured, and the average value is taken as the transmittance of the single plate. The preferable range of polarization performance is 40.5 ≦ TT ≦ 45, 32 ≦ PT ≦ 39.5, and CT ≦ 1.5 in the order of single plate transmittance TT, parallel transmittance PT, and orthogonal transmittance CT, respectively. More preferable ranges are 41.0 ≦ TT ≦ 44.5, 34 ≦ PT ≦ 39.0, and CT ≦ 1.3. In the polarizing plate durability test, the amount of change is preferably smaller.

(Surface treatment of cyclic polyolefin film)
In this invention, in order to improve the adhesiveness of a polarizer and a protective film, it is preferable to surface-treat the surface of a cyclic polyolefin protective film. As for the surface treatment, any method may be used as long as the adhesiveness can be improved. Preferred examples of the surface treatment include glow discharge treatment, ultraviolet irradiation treatment, corona treatment and flame treatment. The glow discharge treatment here refers to so-called low temperature plasma that occurs under low pressure gas. In the present invention, plasma treatment under atmospheric pressure is also preferable. The details of the glow discharge treatment are described in US Pat. No. 3,462,335, US Pat. No. 3,761,299, US Pat. No. 4,072,769, and British Patent No. 891469. A method described in Japanese Patent Publication No. 59-556430 is also used in which the gas composition generated in the vessel is made only when the polyester support itself undergoes a discharge treatment after the discharge starts. In addition, during the vacuum glow discharge treatment, the surface temperature of the film is set to 80 ° C. or more and 180 ° C. or less to perform the discharge treatment.
The method described in the 0-16614 publication can also be applied.

The vacuum degree during the glow discharge treatment is preferably 0.5 to 3000 Pa, more preferably 2 to 300 Pa. The voltage is preferably between 500 and 5000V, more preferably between 500 and 3000V. The discharge frequency to be used is from direct current to several thousand MHz, more preferably 50 Hz to 20 MHz, and further preferably 1 KHz to 1 MHz. The discharge treatment intensity is preferably 0.01 KV · A · min / m ^{2 to 5} KV · A · min / m ² , more preferably 0.15 KV · A · min / m ^{2 to 1} KV · A · min / m ² . is there.

In the present invention, it is also preferable to perform an ultraviolet irradiation method as the surface treatment. For example, it can be carried out by the processing methods described in JP-B 43-2603, JP-B 43-2604, and JP-B 45-3828. The mercury lamp is a high-pressure mercury lamp made of a quartz tube and preferably has an ultraviolet wavelength of 180 to 380 nm. As for the method of ultraviolet irradiation, a high pressure mercury lamp with a dominant wavelength of 365 nm can be used as long as the surface temperature of the protective film rises to around 150 ° C. in terms of the performance of the support. When low-temperature treatment is required, a low-pressure mercury lamp having a dominant wavelength of 254 nm is preferable. It is also possible to use an ozone-less high-pressure mercury lamp and a low-pressure mercury lamp. Regarding the amount of processed light, the greater the amount of processed light, the better the adhesive strength between the thermoplastic saturated alicyclic structure-containing polymer resin film and the polarizer, but there is a problem that the film becomes colored and becomes brittle as the amount of light increases. appear. Therefore, a high-pressure mercury lamp having a main wavelength of 365 nm has a good irradiation light quantity of 20 to 10000 (mJ / cm ² ), more preferably 50 to 2000 (mJ / cm ² ). In the case of low-pressure mercury lamp for a 254nm main wavelength, the irradiation light amount 100~10000 (mJ / cm ²⁾ C., more preferably 300~1500 (mJ / cm ^2).

Furthermore, in the present invention, it is also preferable to perform a corona discharge treatment as the surface treatment. For example, it can be carried out by the processing methods described in JP-B-39-12838, JP-A-47-19824, JP-A-48-28067, and JP-A-52-42114. As the corona discharge treatment apparatus, a solid state corona treatment machine manufactured by Pillar, a LEPEL type surface treatment machine, a VETAPHON type treatment machine, or the like can be used. The treatment can be performed at normal pressure in air. The discharge frequency during the treatment is 5 to 40 KV, more preferably 10 to 30 KV, and the waveform is preferably an AC sine wave. The gap transparent lance between the electrode and the dielectric roll is 0.1 to 10 mm, more preferably 1.0 to 2.0 mm. Discharge is processed above a dielectric support roller provided in the discharge zone, and the treatment amount is 0.3 to 0.4 KV · A · min / m ² ,
More preferably, it is 0.34 to 0.38 KV · A · min / m ² .

In the present invention, it is also preferable to perform a flame treatment as the surface treatment. The gas used may be natural gas, liquefied propane gas, or city gas, but the mixing ratio with air is important.
This is because the effect of surface treatment by flame treatment is thought to be brought about by plasma containing active oxygen, and the point is how much plasma activity (temperature) and oxygen are important properties of flame. is there. The governing factor of this point is the gas / oxygen ratio. When the reaction is performed without excess or deficiency, the energy density is the highest and the plasma activity is increased. Specifically, the preferable mixing ratio of natural gas / air is 1/6 to 1/10, preferably 1/7 to 1/9 in volume ratio. In the case of liquefied propane gas / air, 1/14 to 1/22, preferably 1/16 to 1/19, and in the case of city gas / air, 1/2 to 1/8, preferably 1/3 to 1. / 7. Further, the flame treatment amount is 1 to 50 Kcal / m ² , more preferably 3 to 20 Kcal / m ² . The distance between the tip of the burner inner flame and the film is 3 to 7 cm, more preferably 4 to 6 cm. The burner nozzle shapes are: Flynburner (US) ribbon type, Wise (US) multi-hole type, Aerogen (UK) ribbon type, Kasuga Electric (Japan) staggered multi-hole type, Koike Oxygen ( Japan) is preferred. The backup roll that supports the film for the flame treatment is a hollow roll, and is preferably cooled at a constant temperature of 20 to 50 ° C. by cooling with cooling water.

  As for the degree of surface treatment, the preferred range varies depending on the type of surface treatment and the type of cyclic polyolefin, but as a result of the surface treatment, the contact angle of the surface of the protective film subjected to the surface treatment with pure water is less than 50 ° It is preferable that The contact angle is more preferably 25 ° or more and less than 45 °. When the contact angle with the pure water on the surface of the protective film is in the above range, the adhesive strength between the protective film and the polarizing film becomes good.

(3) Adhesive When laminating a polarizer having polyvinyl alcohol and a protective film having a surface-treated cyclic polyolefin, it is preferable to use an adhesive containing a water-soluble polymer.
Water-soluble polymers preferably used for the adhesive include N-vinylpyrrolidone, acrylic acid, methacrylic acid, maleic acid, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, vinyl alcohol, methyl vinyl ether, vinyl acetate. , Acrylamide, methacrylamide, diacetone acrylamide, vinyl imidazole and other homopolymers or copolymers having ethylenically unsaturated monomers as constituent elements, polyoxyethylene, polyoxypropylene, poly-2-methyloxazoline, methylcellulose, hydroxy Examples thereof include ethyl cellulose and hydroxypropyl cellulose gelatin. Of these, PVA and gelatin are preferred in the present invention.

The preferable PVA characteristic when using PVA for the adhesive is the same as the preferable characteristic of PVA used for the above-mentioned polarizer. In the present invention, it is preferable to use a crosslinking agent in combination. Examples of the cross-linking agent that is preferably used in combination with PVA as an adhesive include boric acid, polyvalent aldehyde, polyfunctional isocyanate compound, and polyfunctional epoxy compound, but boric acid is particularly preferred in the present invention.
When gelatin is used for the adhesive, so-called lime-processed gelatin, acid-processed gelatin, enzyme-processed gelatin, gelatin derivatives and modified gelatin can be used. Of these gelatins, lime-processed gelatin and acid-processed latin are preferably used. When gelatin is used for the adhesive, the crosslinking agent preferably used in combination is an active halogen compound (2,4-dichloro-6-hydroxy-1,3,5-triazine and its sodium salt) and an active vinyl compound ( 1,3-bisvinylsulfonyl-2-propanol, 1,2-bisvinylsulfonylacetamido) ethane, bis (vinylsulfonylmethyl) ether or vinyl polymers having a vinylsulfonyl group in the side chain), N-carbamoylpyridinium salts ((1-morpholinocarbonyl-3-pyridinio) methanesulfonate, etc.) and haloamidinium salts (1- (1-chloro-1-pyridinomethylene) pyrrolidinium 2-naphthalenesulfonate, etc.). In the present invention, active halogen compounds and active vinyl compounds are particularly preferably used.

  When the above-mentioned crosslinking agent is used in combination, the preferred addition amount of the crosslinking agent is 0.1% by mass or more and less than 40% by mass, more preferably 0.5% by mass with respect to the water-soluble polymer in the adhesive. As mentioned above, it is less than 30 mass%. It is preferable to apply an adhesive to at least one surface of the protective film or the polarizer to form an adhesive layer, and to bond the adhesive film. Is preferably bonded to the surface of the polarizer. The thickness of the adhesive layer is preferably 0.01 to 5 μm, and particularly preferably 0.05 to 3 μm after drying.

(Antireflection layer)
It is preferable to provide a functional film such as an antireflection layer on the transparent protective film disposed on the opposite side of the polarizing plate from the liquid crystal cell. In particular, in the present invention, at least a light scattering layer and a low refractive index layer are laminated in this order on the transparent protective film, or a medium refractive index layer, a high refractive index layer, and a low refractive index layer are formed on the transparent protective film. An antireflection layer laminated in order is preferably used. Preferred examples thereof are described below.

A preferred example of an antireflection layer in which a light scattering layer and a low refractive index layer are provided on a transparent protective film will be described.
It is preferable that fine particles are dispersed in the light scattering layer, and the refractive index of the material other than the fine particle of the light scattering layer is preferably in the range of 1.50 to 2.00. The refractive index is preferably in the range of 1.35 to 1.49. The light scattering layer may have both antiglare properties and hard coat properties, and may be a single layer, or may be composed of a plurality of layers, for example, 2 to 4 layers.

The antireflection layer has an uneven surface shape with a center line average roughness Ra of 0.08 to 0.40 μm, a 10-point average roughness Rz of 10 times or less of Ra, an average mountain valley distance Sm of 1 to 100 μm, and an uneven depth. Designed so that the standard deviation of the height of the convex part from the part is 0.5 μm or less, the standard deviation of the average mountain valley distance Sm with respect to the center line is 20 μm or less, and the surface with an inclination angle of 0 to 5 degrees is 10% or more. By doing so, sufficient anti-glare property and uniform fine visual feeling are achieved, which is preferable.
Further, the ratio of the minimum value and the maximum value of the reflectance within the range of the a * value −2 to 2, the b * value −3 to 3, and the 380 nm to 780 nm in the color of the reflected light under the C light source is 0.5. By being -0.99, the color of reflected light becomes neutral, which is preferable. Moreover, it is preferable that the b * value of the transmitted light under the C light source is 0 to 3 because the yellow color of white display when applied to a display device is reduced.
In addition, when a 120 μm × 40 μm grid is inserted between the surface light source and the antireflection film of the present invention and the luminance distribution is measured on the film, the standard deviation of the luminance distribution is 20 or less. Glare when applying the film of the present invention is reduced, which is preferable.

  The optical properties of the antireflection layer are such that the specular reflectance is 2.5% or less, the transmittance is 90% or more, and the 60 ° glossiness is 70% or less, so that reflection of external light can be suppressed and visibility is improved. Therefore, it is preferable. In particular, the specular reflectance is more preferably 1% or less, and most preferably 0.5% or less. Haze 20% to 50%, internal haze / total haze value (ratio) is 0.3 to 1, haze value after formation of low refractive index layer from haze value to light scattering layer is within 15%, comb width Prevents glare on a high-definition LCD panel by setting the transmitted image sharpness at 0.5 mm to 20% to 50% and the transmittance ratio of the vertical transmitted light / at a 2 degree tilt from the vertical to 1.5 to 5.0. Reduction of blurring of characters and the like is achieved, which is preferable.

(Low refractive index layer)
The refractive index of the low refractive index layer of the antireflection film is preferably 1.20 to 1.49, more preferably 1.30 to 1.44. Further, the low refractive index layer preferably satisfies the following formula (IV) from the viewpoint of reducing the reflectance.
Formula (IV): (m / 4) × 0.7 <n1d1 <(m / 4) × 1.3
In the formula, m is a positive odd number, n1 is the refractive index of the low refractive index layer, and d1 is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength and is a value in the range of 500 to 550 nm.

The material for forming the low refractive index layer will be described below.
The low refractive index layer preferably contains a fluorine-containing polymer as a low refractive index binder. The fluorine polymer is preferably a fluorine-containing polymer that is crosslinked by heat or ionizing radiation with a coefficient of dynamic friction of 0.03 to 0.20, a contact angle with water of 90 to 120 °, and a sliding angle of pure water of 70 ° or less. When the antireflection film of the present invention is mounted on an image display device, the lower the peel strength from a commercially available adhesive tape, the easier it is to peel off after sticking a seal or memo, preferably 500 gf or less, more preferably 300 gf or less, 100 gf or less is most preferable. Further, the higher the surface hardness measured with a microhardness meter, the harder it is to scratch, preferably 0.3 GPa or more, more preferably 0.5 GPa or more.

  Examples of the fluorine-containing polymer used in the low refractive index layer include hydrolysis and dehydration condensate of perfluoroalkyl group-containing silane compounds (for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane). And a fluorine-containing copolymer having a fluorine-containing monomer unit and a structural unit for imparting crosslinking reactivity as structural components.

  Specific examples of the fluorine-containing monomer include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc. ), A part of (meth) acrylic acid or a fully fluorinated alkyl ester derivative (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) or M-2020 (manufactured by Daikin)), a complete or partially fluorinated vinyl ether, and the like. Perfluoroolefins are preferred, and hexafluoropropylene is particularly preferred from the viewpoints of refractive index, solubility, transparency, availability, and the like.

  As structural units for imparting crosslinking reactivity, structural units obtained by polymerization of monomers having a self-crosslinkable functional group in advance in the molecule such as glycidyl (meth) acrylate and glycidyl vinyl ether, carboxyl groups, hydroxy groups, amino groups , Obtained by polymerization of a monomer having a sulfo group or the like (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc.) And a structural unit obtained by introducing a crosslinking reactive group such as a (meth) acryloyl group into these structural units by a polymer reaction (for example, it can be introduced by a technique such as allowing acrylic acid chloride to act on a hydroxy group) And the like.

  In addition to the above-mentioned fluorine-containing monomer units and structural units for imparting crosslinking reactivity, monomers not containing fluorine atoms can be copolymerized as appropriate from the viewpoints of solubility in solvents and film transparency. There are no particular limitations on the monomer units that can be used in combination. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2) -Ethylhexyl), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers (methyl) Vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate etc.), acrylamides (N-tert-butylacrylamide, N- Black hexyl acrylamide), methacrylamides, and acrylonitrile derivatives.

  As described in JP-A-10-25388 and JP-A-10-147739, a curing agent may be appropriately used in combination with the above polymer.

(Light scattering layer)
The light scattering layer is formed for the purpose of contributing to the film light diffusibility due to surface scattering and / or internal scattering and hard coat properties for improving the scratch resistance of the film. Accordingly, it preferably includes a binder for imparting hard coat properties, fine particle particles for imparting light diffusibility, and an inorganic filler for increasing the refractive index, preventing crosslinking shrinkage, and increasing the strength as necessary. Formed with.

The thickness of the light scattering layer is preferably from 1 to 10 μm, more preferably from 1.2 to 6 μm, from the viewpoint of imparting hard coat properties and from the viewpoint of curling and suppression of deterioration of brittleness.

  The binder of the scattering layer is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as the main chain, and more preferably a polymer having a saturated hydrocarbon chain as the main chain. The binder polymer preferably has a crosslinked structure. As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable. In order to make the binder polymer have a high refractive index, the monomer structure contains an aromatic ring, at least one atom selected from halogen atoms other than fluorine, sulfur atoms, phosphorus atoms, and nitrogen atoms. You can also choose.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di ( (Meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol Tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-si Rhohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), modified ethylene oxide, vinylbenzene and derivatives thereof (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1, 4-divinylcyclohexanone), vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.

  Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, and the like. Two or more of these monomers may be used in combination.

Polymerization of these monomers having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
Accordingly, a coating liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, fine particles and an inorganic filler is prepared, and the coating liquid is applied on a transparent support and then ionized radiation or heat is applied. It can be cured by a polymerization reaction to form an antireflection film. As these photo radical initiators, known ones can be used.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Therefore, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, fine particles and an inorganic filler is prepared, and the coating liquid is applied on a transparent support and cured by a polymerization reaction by ionizing radiation or heat. Thus, an antireflection film can be formed.

Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition.
These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

For the purpose of imparting antiglare properties, the light scattering layer contains fine particles having an average particle diameter of 1 to 10 μm, preferably 1.5 to 7.0 μm, such as inorganic compound particles or resin particles, for the purpose of imparting antiglare properties. It is preferable.
Specific examples of the fine particles include preferably particles of inorganic compounds such as silica particles and TiO ₂ particles; resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles. It is done. Of these, crosslinked styrene particles, crosslinked acrylic particles, crosslinked acrylic styrene particles, and silica particles are preferable. The shape of the fine particles can be either spherical or irregular.

  Further, two or more kinds of fine particles having different particle diameters may be used in combination. Anti-glare properties can be imparted with fine particles having a larger particle size, and other optical characteristics can be imparted with fine particles having a smaller particle size.

  Furthermore, the particle size distribution of the fine particles is most preferably monodispersed, and the particle size of each particle is preferably as close as possible. For example, when particles having a particle size of 20% or more than the average particle size are defined as coarse particles, the proportion of coarse particles is preferably 1% or less of the total number of particles, more preferably 0.1%. Or less, more preferably 0.01% or less. Fine particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and fine particles having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

The fine particles are contained in the light scattering layer so that the amount of fine particles in the formed light scattering layer is preferably 10 to 1000 mg / m ² , more preferably 100 to 700 mg / m ² .
The particle size distribution of the fine particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

The light scattering layer is made of an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin and antimony in addition to the above fine particles in order to increase the refractive index of the layer. In addition, it is preferable that an inorganic filler having an average particle size of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less is contained.
Conversely, in order to increase the difference in refractive index from the fine particles, it is also preferable to use a silicon oxide in order to keep the refractive index of the layer low in the light scattering layer using high refractive index fine particles. The preferred particle size is the same as that of the aforementioned inorganic filler.
Specific examples of the inorganic filler to be used in the light scattering _{layer, TiO 2, ZrO 2, Al} 2 O 3, In 2 O 3, ZnO, SnO 2, Sb 2 O 3, ITO and SiO ₂ and the like. TiO ₂ and ZrO ₂ are particularly preferable from the viewpoint of increasing the refractive index. The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used. The amount of these inorganic fillers added is preferably 10 to 90% of the total mass of the light scattering layer, more preferably 20 to 80%, and particularly preferably 30 to 75%. Such fillers are
Since the particle size is sufficiently smaller than the wavelength of light, no scattering occurs, and the dispersion in which the filler is dispersed in the binder polymer behaves as an optically uniform substance.

  The bulk refractive index of the mixture of binder and inorganic filler in the light scattering layer is preferably 1.48 to 2.00, more preferably 1.50 to 1.80. In order to make the refractive index within the above range, the kind and amount ratio of the binder and the inorganic filler may be appropriately selected. How to select can be easily known experimentally in advance.

  In order to ensure surface uniformity such as coating unevenness, drying unevenness, point defects, etc., the light scattering layer should be coated with either a fluorine-based surfactant or a silicone-based surfactant, or both for forming an antiglare layer. It is preferable to contain in a composition. In particular, a fluorine-based surfactant is preferably used because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the antireflection film of the present invention appears in a smaller addition amount. The purpose is to increase productivity by giving high-speed coating suitability while improving surface uniformity.

Next, an antireflection layer in which a middle refractive index layer, a high refractive index layer, and a low refractive index layer are laminated in this order on the transparent protective film will be described.
An antireflection film comprising at least a middle refractive index layer, a high refractive index layer, and a low refractive index layer (outermost layer) in order on the substrate must be designed to have a refractive index satisfying the following relationship: Is preferred.
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 Further, a hard coat layer is provided between the transparent support and the medium refractive index layer. Also good. Further, it may be composed of a medium refractive index hard coat layer, a high refractive index layer and a low refractive index layer (for example, JP-A-8-122504, JP-A-8-110401, JP-A-10-300902, (See JP 2002-243906, JP 2000-11706, etc.). Other functions may be imparted to each layer, for example, an antifouling low refractive index layer or an antistatic high refractive index layer (eg, 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 preferably composed of a curable film containing at least an inorganic compound ultrafine particle having a high refractive index having an average particle diameter of 100 nm or less and a matrix binder.
The inorganic compound fine particles having a high refractive index 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, silane coupling agents, etc .: JP-A-11-295503, JP-A-11-153703, JP-A-2000-9908). , Anionic compounds or organometallic coupling agents: Japanese Patent Application Laid-Open No. 2001-310432, etc., a core-shell structure with high refractive index particles as a core (: Japanese Patent Application Laid-Open No. 2001-1661042001-310432, etc.), specific (For example, JP-A-11-153703, U.S. Pat. No. 6,210,858, 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, a polyfunctional compound-containing composition having at least two radically polymerizable and / or cationically polymerizable groups, and a composition containing an organometallic compound having a hydrolyzable group and a partial condensate thereof. At least one composition selected is preferred. For example, the composition as described in Unexamined-Japanese-Patent No. 2000-47004, 2001-315242, 2001-31871, 2001-296401 etc. is mentioned.
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. The thickness is preferably 5 nm to 10 mμ, more preferably 10 nm to 1 μm.

(Low refractive index layer)
In the above configuration, the low refractive index layer is sequentially laminated on the high refractive index layer. The refractive index of the low refractive index layer is preferably 1.20 to 1.55, more preferably 1.30 to 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, it is effective to impart slipperiness to the surface, and conventionally known thin film layer means such as introduction of silicone or introduction of fluorine 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 (eg, 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 as or after the application of the coating composition for forming the outermost layer containing a polymerization initiator, a sensitizer and the like. 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 compound, paragraph No. [0 of JP-A-11-3820
020] to [0038], silane coupling agents, slip agents, surfactants, and the like.
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.

(Other layers of antireflection layer)
Further, a hard coat layer, a forward scattering layer, a primer layer, an antistatic layer, an undercoat layer, a protective layer, and the like may be provided.

(Hard coat layer)
The hard coat layer is usually provided on the surface of the transparent support in order to impart physical strength to the transparent protective film provided with the antireflection layer. 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 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 and imparted with 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 more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test according to JIS K5400. Moreover, in the Taber test according to JIS K5400, the smaller the amount of wear of the test piece before and after the test, the better.

(Antistatic layer)
When an antistatic layer is provided, it is preferable to impart conductivity with a volume resistivity of 10 ⁻⁸ (Ωcm ⁻³ ) or less. The use of hygroscopic substances, water-soluble inorganic salts, certain surfactants, cationic polymers, anionic polymers, colloidal silica, etc. can give a volume resistivity of 10 ⁻⁸ (Ωcm ⁻³ ). There is a problem that dependency is large, and sufficient conductivity cannot be secured at low humidity. Therefore, a metal oxide is preferable as the conductive layer material. It is preferable to use a non-colored metal oxide as the conductive layer material because the coloration of the entire film is suppressed. Zn, Ti, Al, In, Si, Mg, Ba, Mo, W, or V can be given as the metal that forms the metal oxide without coloring, and a metal oxide containing this as a main component should be used. preferable. Specific examples include ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₃ , V ₂ O ₅ , or a composite oxide thereof. In particular, ZnO, TiO ₂ and SnO ₂ are preferable. Examples of containing different atoms include, for example, additives such as Al and In for ZnO, addition of Sb, Nb and halogen elements for SnO ₂ , and Nb and TA for TiO ₂ . Addition is effective. Furthermore, as described in Japanese Examined Patent Publication No. 59-6235, a material obtained by adhering the above metal oxide to other crystalline metal particles or fibrous materials (for example, titanium oxide) may be used. The volume resistance value and the surface resistance value are different physical properties and cannot be simply compared. However, in order to secure a conductivity of 10 ⁻⁸ (Ωcm ⁻³ ) or less in volume resistance, It is sufficient that the layer has a surface resistance value of about 10 ⁻¹⁰ (Ω / □) or less, and more preferably 10 ⁻⁸ (Ω / □). The surface resistance value of the conductive layer needs to be measured as a value when the antistatic layer is the outermost layer, and can be measured in the middle of forming the laminated film described in this patent.

(Liquid crystal display device)
The cyclic polyolefin film of the present invention, a retardation film comprising the film, and a polarizing plate using the film can be used for liquid crystal cells and liquid crystal display devices in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal, AFLC) Various display modes such as HAN (Hybrid Aligned Nematic) have been proposed. Of these, the OCB mode or the VA mode can be preferably used.

  The OCB mode liquid crystal cell is a liquid crystal display device using a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between an upper portion and a lower portion of the liquid crystal cell. OCB mode liquid crystal cells are disclosed in US Pat. Nos. 4,583,825 and 5,410,422. Since the rod-like liquid crystal molecules are aligned symmetrically between the upper part and the lower part of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. For this reason, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied.
The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). (2) In addition to (2) Liquid Crystal Cell (SID97, Digest of tech. Papers (Preliminary Collection) 28 (1997) 845 in which VA mode is multi-domained (in MVA mode) for viewing angle expansion ), (3) Liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (1998)) and (4) SURVAIVAL mode liquid crystal cells (announced at LCD International 98).
The VA mode liquid crystal display device includes a liquid crystal cell and two polarizing plates disposed on both sides thereof. The liquid crystal cell carries a liquid crystal between two electrode substrates. In one aspect of the transmissive liquid crystal display device of the present invention, the retardation film of the present invention is disposed between the liquid crystal cell and one polarizing plate, or between the liquid crystal cell and both polarizing plates. Place two in between.
In another aspect of the transmissive liquid crystal display device of the present invention, a retardation film made of the cyclic polyolefin film of the present invention is used as a transparent protective film of a polarizing plate disposed between a liquid crystal cell and a polarizer. The above retardation film may be used only for the transparent protective film (between the liquid crystal cell and the polarizer) of one polarizing plate, or between the polarizing plates (between the liquid crystal cell and the polarizer). The retardation film may be used for the two transparent protective films. When the retardation film is used only for one polarizing plate, it is particularly preferable to use it as a liquid crystal cell side protective film of a backlight side polarizing plate of a liquid crystal cell. For the lamination to the liquid crystal cell, the cyclic polyolefin film of the present invention is preferably on the VA cell side. The protective film may be a normal cell rate acylate film. For example, 40 to 80 μm is preferable, and examples include, but are not limited to, commercially available KC4UX2M (40 μm manufactured by Konica Capto), KC5UX (60 μm manufactured by Konica Capto), TD80 (80 μm manufactured by Fuji Photo Film), and the like. .

(Optical compensation film)
In a liquid crystal display device such as an OCB mode or a TN mode, an optical compensation film is generally used for widening the viewing angle. An optical compensation film for an OCB cell is generally used in which an optically anisotropic layer in which a discotic liquid crystal is hybrid-aligned and fixed on an optically uniaxial or biaxial film is used. As the optical compensation film for a TN cell, a film in which an optical anisotropic layer in which a discotic liquid crystal is hybrid-aligned and fixed on a film having an optical isotropy or an optical axis in the thickness direction is generally used. The cyclic polyolefin film of the present invention is useful for producing an optical compensation film for the OCB cell or TN cell.
Suitable optical characteristics of the optical compensation film are as described above.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to an Example.
<Synthesis of Cyclic Polyolefin Polymer P-1>
100 parts by mass of purified toluene and 100 parts by mass of norbornenecarboxylic acid methyl ester were charged into the reaction kettle. Next, ethylhexanoate-Ni 25 mmol% (based on monomer weight) dissolved in toluene, tri (pentafluorophenyl) boron 0.225 mol% (based on monomer weight), and triethylaluminum 0.25 mol% (based on monomer weight) dissolved in toluene ) Was charged into the reaction kettle. The reaction was allowed to proceed for 18 hours at room temperature with stirring. After completion of the reaction, the reaction mixture was put into excess ethanol to produce a polymer precipitate. The polymer (P-1) obtained by purifying the precipitate was vacuum dried at 65 ° C. for 24 hours.

[Example 1]
The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.

―――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-1
―――――――――――――――――――――――――――――――――
Cyclic polyolefin P-1 150 parts by mass Liquid paraffin: Daphne Oil CP68 (Idemitsu Kosan Co., Ltd.) 15 parts by mass Dichloromethane 380 parts by mass Methanol 70 parts by mass ――――――――――――――――― ―――――――――――――――

  Next, the following composition containing the cyclic polyolefin solution prepared by the above method was charged into a disperser to prepare a fine particle dispersion.

―――――――――――――――――――――――――――――――――
Fine particle dispersion M-1
―――――――――――――――――――――――――――――――――
Silica particles having a primary average particle size of 16 nm (aerosil R972 Nippon Aerosil Co., Ltd.) 2 parts by mass Dichloromethane 73 parts by mass Methanol 10 parts by mass Cyclic polyolefin solution D-1 10 parts by mass ―――――――――――――――――――――

100 parts by mass of the above cyclic polyolefin solution D-1 and 1.35 parts by mass of the fine particle dispersion M-1 were mixed to prepare a dope for film formation.
The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 25% by mass was dried and wound up at 120 to 140 ° C. while keeping the film from getting wrinkled. The thickness, Re retardation, Rth retardation, visual unevenness and processing suitability of the produced film are measured and are shown in Table 1. The variation of Re retardation and Rth retardation marked the difference between the maximum value and the minimum value of 7 samples obtained by sampling 130 cm wide samples at 20 cm intervals. For optical unevenness, a sample was inserted between polarizing plates arranged in crossed Nicols and visually evaluated, and relative evaluation with Comparative Example 1 was marked. In addition, the processing suitability was evaluated by stacking three films on a 10 cm square film punching machine, punching, and cracks generated at four corners.

[Example 2]
In Example 1, instead of liquid paraffin: Daphne Oil CP68 (Idemitsu Kosan Co., Ltd.), except that 7.5 parts by mass of polypropylene glycol 700 (Wako Pure Chemical Industries, Ltd.) was used, the film was formed in the same manner. Created. Various properties of the produced film are shown in Table 1.

Example 3
In Example 1, a film was prepared in exactly the same manner except that 15 parts by mass of paraffin wax 120 (Nippon Seiwa Co., Ltd.) was used instead of liquid paraffin: Daphne Oil CP68 (Idemitsu Kosan Co., Ltd.). . Various properties of the produced film are shown in Table 1.

Example 4
100 parts by mass of the above cyclic polyolefin solution D-1 and 1.35 parts by mass of the fine particle dispersion M-1 were mixed to prepare a dope for film formation. The above dope was cast using a band casting machine. A film peeled off from the band with a residual solvent amount of about 25% by mass was stretched in the width direction while applying hot air using a tenter. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. Table 1 shows the stretching temperature, stretching ratio, and various film properties.

Example 5
The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.

――――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-2
――――――――――――――――――――――――――――――――――
Cyclic polyolefin: Appar 3000 100 parts by mass Liquid paraffin: Daphne Oil KP100 (Idemitsu Kosan Co., Ltd.) 15 parts by mass Dichloromethane 380 parts by mass Methanol 70 parts by mass ――――――――――――――――― ――――――――――――――――

  Next, the following composition containing the cyclic polyolefin solution prepared by the above method was charged into a disperser to prepare a fine particle dispersion.

―――――――――――――――――――――――――――――――――
Fine particle dispersion M-2
―――――――――――――――――――――――――――――――――
Silica particles having a primary average particle size of 16 nm (aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass Dichloromethane 73 parts by mass Methanol 10 parts by mass Cyclic polyolefin solution D-2 10 parts by mass ――――――――――― ――――――――――――――――――――――

  100 parts by mass of the cyclic polyolefin solution D-2 and 1.35 parts by mass of the fine particle dispersion M-2 were mixed to prepare a dope for film formation. The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 25% by mass was dried and wound up at 120 to 140 ° C. while keeping the film from getting wrinkled. Various properties of the produced film are shown in Table 1.

Example 6
In Example 5, a film was prepared in exactly the same manner except that 10 parts by mass of polyethylene glycol 600 (Wako Pure Chemical Industries, Ltd.) was used instead of liquid paraffin: Daphne Oil KP100 (Idemitsu Kosan Co., Ltd.). . Various properties of the produced film are shown in Table 1.

Example 7
The dope used in Example 6 was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 35% by mass was stretched in the width direction while applying hot air using a tenter. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. Table 1 shows the stretching temperature, stretching ratio, and various film properties.

Example 8
The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.

―――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-3
―――――――――――――――――――――――――――――――――
Cyclic polyolefin: TOPAS 5013 100 parts by weight paraffin wax 135 (Nippon Seiwa Co., Ltd.) 15 parts by weight cyclohexane 380 parts by weight dichloromethane 70 parts by weight --------- ――――――――――――

  Next, the following composition containing the cyclic polyolefin solution prepared by the above method was charged into a disperser to prepare a fine particle dispersion.

―――――――――――――――――――――――――――――――――
Fine particle dispersion M-3
―――――――――――――――――――――――――――――――――
Silica particles having a primary average particle size of 16 nm (aerosil R972 Nippon Aerosil Co., Ltd.) 2 parts by mass cyclohexane 73 parts by mass dichloromethane 10 parts by mass cyclic polyolefin solution D-3 10 parts by mass ――――――――――― ―――――――――――――――――――――

  100 parts by mass of the cyclic polyolefin solution D-3 and 1.35 parts by weight of the fine particle dispersion M-3 were mixed to prepare a dope for film formation. The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 35% by mass was dried and wound at 120 to 140 ° C. while keeping the film from getting wrinkled. Various properties of the produced film are shown in Table 1.

Example 9
The dope used in Example 8 was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 35% by mass was stretched in the width direction while applying hot air using a tenter. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. Table 1 shows the stretching temperature, stretching ratio, and various film properties.

Example 10
The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.

―――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-4
―――――――――――――――――――――――――――――――――
Cyclic polyolefin: Zeonor ZF-14 100 parts by weight paraffin wax 135 (Nippon Seiwa Co., Ltd.) 10 parts by weight cyclohexane 450 parts by weight ――――――――――――――――――――― ―――――――――――

  Next, the following composition containing the cyclic polyolefin solution prepared by the above method was charged into a disperser to prepare a fine particle dispersion.

―――――――――――――――――――――――――――――――――
Fine particle dispersion M-4
―――――――――――――――――――――――――――――――――
Silica particles having a primary average particle size of 16 nm (aerosil R972 Nippon Aerosil Co., Ltd.) 2 parts by mass Cyclohexane 83 parts by mass Cyclic polyolefin solution D-4 10 parts by mass ――――――――――――――― ―――――――――――――――――

  100 parts by mass of the cyclic polyolefin solution D-4 and 1.35 parts by mass of the fine particle dispersion M-4 were mixed to prepare a dope for film formation. The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 35% by mass was dried and wound at 120 to 140 ° C. while keeping the film from getting wrinkled. Various properties of the produced film are shown in Table 1.

Example 11
The dope used in Example 10 was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 35% by mass was stretched in the width direction while applying hot air using a tenter. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. Table 1 shows the stretching temperature, stretching ratio, and various film properties.

Example 12
The following composition was placed in a mixing tank and stirred to dissolve each component.
It filtered with the filter paper of micrometer, and the sintered metal filter with an average hole diameter of 10 micrometers.

―――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-5
―――――――――――――――――――――――――――――――――
Cyclic polyolefin: ARTON-G 150 parts by mass Liquid paraffin: Daphne Oil CP68 (Idemitsu Kosan Co., Ltd.) 15 parts by mass Dichloromethane 450 parts by mass Surfactant RZ-13 0.7 parts by mass ――――――――― ―――――――――――――――――――――――

  Next, the following composition containing the cyclic polyolefin solution prepared by the above method was charged into a disperser to prepare a fine particle dispersion.

―――――――――――――――――――――――――――――――――
Fine particle dispersion M-5
―――――――――――――――――――――――――――――――――
Silica particles having a primary average particle diameter of 16 nm (aerosil R972 Nippon Aerosil Co., Ltd.) 2 parts by mass Dichloromethane 83 parts by mass Cyclic polyolefin solution D-5 10 parts by mass ――――――――――――――― ―――――――――――――――――

  100 parts by mass of the cyclic polyolefin solution D-5 and 1.35 parts by mass of the fine particle dispersion M-5 were mixed to prepare a dope for film formation. The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 25% by mass was dried and wound up at 120 to 140 ° C. while keeping the film from getting wrinkled. The thickness, Re retardation, Rth retardation and visual optical unevenness of the produced film were measured and listed in Table 1.

Example 13
The dope used in Example 12 was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 35% by mass was stretched in the width direction while applying hot air using a tenter. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. Table 1 shows the stretching temperature, stretching ratio, and various film properties.

[Comparative Example 1]
The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.

―――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-6
―――――――――――――――――――――――――――――――――
Cyclic polyolefin P-1 150 parts by mass Dibutyl phthalate (Wako Pure Chemical Industries, Ltd.) 10 parts by mass Dichloromethane 380 parts by mass Methanol 70 parts by mass ――――――――――――――――――――― ――――――――――――

Next, the following composition containing the cyclic polyolefin solution prepared by the above method is charged into a disperser,
A fine particle dispersion was prepared.

―――――――――――――――――――――――――――――――――
Fine particle dispersion M-6
―――――――――――――――――――――――――――――――――
Silica particles having a primary average particle size of 16 nm (aerosil R972 Nippon Aerosil Co., Ltd.) 2 parts by mass Dichloromethane 73 parts by mass Methanol 10 parts by mass Cyclic polyolefin solution D-6 10 parts by mass ――――――――――― ―――――――――――――――――――――

100 parts by mass of the cyclic polyolefin solution D-6 and 1.35 parts by mass of the fine particle dispersion M-6 were mixed to prepare a dope for film formation.
The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 25% by mass was dried and wound up at 120 to 140 ° C. while keeping the film from getting wrinkled. Various properties of the produced film are shown in Table 1.

[Comparative Example 2]
100 parts by mass of the above cyclic polyolefin solution D-6 and 1.35 parts by mass of the fine particle dispersion M-6 were mixed to prepare a dope for film formation. The above dope was cast using a band casting machine. A film peeled off from the band with a residual solvent amount of about 25% by mass was stretched in the width direction while applying hot air using a tenter. Thereafter, the tenter transport was shifted to the roll transport, and further dried at 120 to 140 ° C. and wound up. Table 1 shows the stretching temperature, stretching ratio, and various film properties.

[Comparative Example 3]
A film was prepared in exactly the same manner as in Example 1 except that the dope was adjusted except for Daphne Oil CP68. Various properties of the produced film are shown in Table 1.

[Comparative Example 4]
A film was prepared in the same manner as in Example 10 except that the dope was adjusted except for the Daphne oil CP68. Various properties of the produced film are shown in Table 1.

[Comparative Example 5]
The following composition was put into a mixing tank, stirred to dissolve each component, and then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm.

―――――――――――――――――――――――――――――――――
Cyclic polyolefin solution D-7
―――――――――――――――――――――――――――――――――
Cyclic polyolefin: ARTON-G 80 parts by weight ethylphthalyl ethyl glycolate 2 parts by weight triphenyl phosphate 8 parts by weight dichloromethane (boiling point: 39.8 ° C.) 250 parts by weight ethanol 10 parts by weight ――――――――― ―――――――――――――――――――――――

The above materials were put into a melting pot, heated to 70 ° C., and while stirring, the cyclic polyolefin was completely dissolved to obtain a cyclic polyolefin solution D-7. The time required for dissolution was 4
It was time. The filter was then filtered using a filter paper having an absolute filtration accuracy of 0.005 mm and a filtration flow rate of 300 l / m ² · hr and a filtration pressure of 1.0 × 10 6 Pa.

―――――――――――――――――――――――――――――――――
Fine particle dispersion M-7 stock solution ――――――――――――――――――――――――――――――――――
Ethanol 27 parts by mass Silica particles with a primary average particle size of 16 nm (aerosil R972V Nippon Aerosil Co., Ltd.) 3 parts by mass ――――――――――――――――――――――――― ――――――――

The above materials were mixed in a predetermined container, stirred for 30 minutes at a rotation speed of 500 rpm, and then dispersed at a pressure of 250 kgf / cm ^{2 with} a Manton Gorin type high-pressure disperser. Particulate dilution M-7 was prepared. Next, 75 parts by mass of cyclic polyolefin solution D-7, 25 parts by mass of 2- (2-hydroxy-3 ′, 5′-di-t-butylphenyl) bezotriazole, 60 parts by mass of fine particle dispersion M-7, dichloromethane After adding 290 parts by mass to the melting pot, the dope was prepared by heating to 40 ° C. and dissolving for 30 minutes. The above dope was cast using a band casting machine. The film peeled off from the band with a residual solvent amount of about 25% by mass was dried and wound up at 120 to 140 ° C. while keeping the film from getting wrinkled. Various properties of the produced film are shown in Table 1.

Workability evaluation (evaluated by the number of cracks at 12 locations)
○: No cracking △: Within 3 places ×: Evaluation of visual unevenness over 4 places ○: No unevenness is recognized Δ: Some unevenness is recognized but within the allowable range ×: Not practical

Example 14
(Preparation of polarizing plate)
A polarizer was produced by adsorbing iodine to a stretched polyvinyl alcohol film. The cyclic polyolefin films (F-4 and F-10, respectively) produced in Examples 4 and 10 were subjected to glow discharge treatment (frequency 3000 Hz, 4200 V high frequency voltage applied between upper and lower electrodes, treatment for 20 seconds), and then Using a polyvinyl alcohol-based adhesive, it was attached to the front and back of the polarizer and dried at 70 ° C. for 10 minutes or more. In the prepared polarizing plate A, a cyclic polyolefin film F-4 was attached to one side of the polarizer, and a cyclic polyolefin film F-10 was attached to the opposite surface. Further, the transmission axis of the polarizer and the slow axis of the cyclic polyolefin film F-10 were arranged in parallel. The transmission axis of the polarizer and the slow axis of the cyclic polyolefin film F-4 were arranged so as to be orthogonal to each other. In the prepared polarizing plate B, the cyclic polyolefin film F-4 was attached to both sides of the polarizer. The transmission axis of the polarizer and the slow axis of the cyclic polyolefin film F-4 were arranged so as to be orthogonal to each other.

<Production of VA liquid crystal cell>
The liquid crystal cell has a cell gap between substrates of 3.6 μm, and a liquid crystal material having negative dielectric anisotropy (“MLC6608”, manufactured by Merck & Co., Inc.) is dropped between the substrates and sealed. Prepared by forming a layer. The retardation of the liquid crystal layer (that is, the product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn) was set to 300 nm. The liquid crystal material was aligned so as to be vertically aligned. The prepared polarizing plate B was attached to the upper side (observer side) of this vertical alignment type liquid crystal cell via an adhesive. The prepared polarizing plate A was attached to the lower side (backlight side) of the liquid crystal cell via an adhesive such that the F-10 side was the liquid crystal cell side. The crossed Nicols were arranged so that the transmission axis of the upper polarizing plate was in the vertical direction and the transmission axis of the lower polarizing plate was in the left-right direction.
As a result of observing the manufactured liquid crystal display device, the display along the image was uniform and was satisfactory.

Claims (9)

  A cyclic polyolefin film comprising a cyclic polyolefin resin and at least one compound selected from a polyolefin compound and a polyethylene glycol compound.   The cyclic polyolefin film according to claim 1, wherein the compound is a compound having a molecular weight of 20000 or less.   The cyclic polyolefin film according to claim 1, wherein the compound is a compound having an I / O value of 0.5 or less.   Including at least one cyclic polyolefin resin and at least one compound selected from a polyolefin compound and a polyethylene glycol compound in a solvent, a casting step, a drying step, and a winding step. A method for producing a cyclic polyolefin film.   The method for producing a cyclic polyolefin film according to claim 4, wherein the film is stretched after the casting step.   The protective film for polarizing plates which has the cyclic polyolefin film in any one of Claims 1-3.   An optical compensation film comprising the cyclic polyolefin film according to claim 1.   A polarizing plate comprising the polarizing plate protective film according to claim 6.   At least one of the cyclic polyolefin film according to any one of claims 1 to 3, the protective film for a polarizing plate according to claim 6, the optical compensation film according to claim 7, and the polarizing plate according to claim 8. A liquid crystal display device comprising one.