CN116097140A

CN116097140A - Optical film, polarizing plate and liquid crystal display device

Info

Publication number: CN116097140A
Application number: CN202180058808.3A
Authority: CN
Inventors: 小出卓哉; 松本彩花; 梅田博纪; 田坂公志; 南条崇
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 2020-07-29
Filing date: 2021-07-20
Publication date: 2023-05-09
Also published as: JPWO2022024879A1; WO2022024879A1; KR20230029872A; TW202212432A; TWI814019B

Abstract

The optical film of the present invention is an optical film comprising a cycloolefin resin, wherein the cycloolefin resin is a resin comprising an ethylene compound as a copolymerization component, and the optical film has a moisture permeability (40 ℃ C., 95% RH) of 0.1 to 60 g/(m) ² 24 h), and the optical film has a roughened surface on one side, and the roughened surface has an external haze of 0.02% or more and less than 0.10% on one side.

Description

Optical film, polarizing plate and liquid crystal display device

Technical Field

The present invention relates to an optical film, a polarizing plate, and a liquid crystal display device, and more particularly, to an optical film capable of suppressing blurring of a panel without reducing adhesion force with an adhesive sheet, a polarizing plate using the optical film, and a liquid crystal display device.

Background

A polarizing plate used in an image display device such as a TV or a smart phone has a protective film attached to both surfaces of a polarizer via an adhesive layer. In addition, when a polarizing plate is bonded to a liquid crystal cell, an adhesive sheet composed of an adhesive composition is widely used. In order to ensure the adhesiveness of the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet itself needs to contain water, and an acid component such as carboxylic acid is required.

In recent years, when polarizing plates and image display devices are shipped overseas, durability under environments with extreme temperatures and humidity has been demanded. However, when the optical film bonded to the liquid crystal cell via the adhesive sheet has low moisture permeability, there is a problem that moisture in the adhesive sheet is retained at the interface with the optical film due to environmental changes, and a blurred "high-humidity impact" is generated on the panel.

Accordingly, in order to solve the above-mentioned problems, in the technique disclosed in patent document 1, the use of an adhesive sheet containing no acid component such as carboxylic acid provides an adhesive sheet having higher thermal durability and wet heat durability than an adhesive sheet containing an acid component, and the water content of the adhesive sheet can be reduced and high-humidity impact can be prevented.

However, when the adhesive sheet contains no acid component, the adhesive strength of the adhesive sheet is reduced, and it is difficult to attach the polarizing plate.

Prior art literature

Patent literature

Patent document 1 Japanese patent application laid-open No. 2019-206629

Disclosure of Invention

Technical problem to be solved by the invention

The present invention has been made in view of the above problems and conditions, and solves the technical problems: provided are an optical film capable of suppressing blurring of a panel without reducing the adhesion force with an adhesive sheet, and a polarizing plate and a liquid crystal display device using the optical film.

Technical means for solving the problems

In order to solve the above-described problems, the present inventors have found that, in the course of studying the cause of the problems and the like: the present invention has been completed by the fact that the higher the single-sided external haze on the roughened surface side of an optical film containing a cycloolefin resin having a roughened surface on one side, the higher the adhesion of the optical film containing a cycloolefin resin and an adhesive sheet, and the blur of the panel is suppressed.

That is, the technical problem of the present invention is solved by the following means.

1. An optical film comprising a cycloolefin resin, wherein,

the cycloolefin resin is a resin containing an ethylene compound as a copolymerization component,

the optical film has a moisture permeability (40 ℃ C., 95% RH) of 0.1 to 60 g/(m) ² 24 h), and,

the optical film has a roughened surface on one side, and the roughened surface has an external haze of 0.02% or more and less than 0.10% on one side.

2. The optical film according to claim 1, wherein,

the ratio of the single-sided external haze of the roughened surface to the single-sided external haze of the back surface opposite to the roughened surface is 1.1:1.0 or more and less than 10.0:1.0.

3. The optical film according to claim 1, wherein,

The rear surface opposite to the roughened surface has: an easy-to-adhere layer containing at least one of an acrylic resin, a vinyl resin, a urethane resin, and a polyester resin.

4. A polarizing plate comprising at least a polarizing plate protective film, a polarizer, an optical film and an adhesive sheet laminated in this order,

the optical film according to any one of items 1 to 3.

5. The polarizing plate according to claim 4, wherein,

the water content of the adhesive sheet is 10.0% or less at 40 ℃ under 95% RH.

6. A liquid crystal display device in which the polarizing plate according to claim 4 or 5 is bonded to at least one surface of a liquid crystal cell,

the adhesive sheet is adjacent to the liquid crystal cell.

ADVANTAGEOUS EFFECTS OF INVENTION

The method of the present invention can provide an optical film capable of suppressing blurring of a panel without reducing the adhesion force with an adhesive sheet, a polarizing plate using the optical film, and a liquid crystal display device.

The expression mechanism or action mechanism of the effect of the present invention is not specifically defined, but it is assumed that the following is possible.

In the cycloolefin resin containing optical film having a roughened surface on one side, it is considered that the higher the external haze of one side on the roughened surface side is, the larger the surface roughness of the roughened surface is, and the larger the contact area with the adhesive sheet is, so that the adhesion between the cycloolefin resin containing optical film and the adhesive sheet is improved. Further, by increasing the contact area, the amount of moisture absorbed by the adhesive sheet can be increased, and therefore blurring of the panel can be suppressed.

Therefore, in the present invention, the moisture permeability (40 ℃ C., 95% RH) of the optical film is set to 0.1 to 60 g/(m) ² 24 h), the optical film has a roughened surface on one surface, and the roughened surface has a single-surface external haze of 0.02% or more and less than 0.10%, so that the roughened surface side has a high single-surface external haze, and the surface roughness is also large, and the contact area with the adhesive sheet is large, thereby improving the adhesive force with the adhesive sheet. Further, the amount of moisture absorbed by the pressure-sensitive adhesive sheet can be increased, so that blurring of the panel can be suppressed.

Drawings

FIG. 1 is a schematic view showing an example of the constitution of a polarizing plate of the present invention

FIG. 2 is a schematic view showing an example of the constitution of a liquid crystal display device of the present invention

Detailed Description

This feature is common to or corresponding to the following embodiments.

In the embodiment of the present invention, the ratio of the single-sided external haze of the roughened surface to the single-sided external haze of the back surface opposite to the roughened surface is preferably 1.1:1.0 or more and less than 10.0:1.0, since the single-sided external haze of the roughened surface side is high and the surface roughness is also large, the adhesion is further improved, and the absorption amount of moisture emitted from the adhesive sheet is increased, so that blurring of the panel can be reliably suppressed.

In addition, from the viewpoint of improving the adhesion to the back surface, it is preferable that the back surface opposite to the roughened surface has: an easy-to-adhere layer containing at least one of an acrylic resin, a vinyl resin, a urethane resin, and a polyester resin.

The optical film of the present invention is suitable for a polarizing plate comprising a polarizing plate protective film, a polarizer, an optical film and an adhesive sheet laminated in this order. In this polarizer, the water content of the adhesive sheet in the environment of 40 ℃ and 95% rh is preferably 10.0% or less, from the viewpoint of reliably suppressing blurring of the panel.

The polarizing plate of the present invention is applied to a liquid crystal display device in which the polarizing plate is bonded to at least one surface of a liquid crystal cell, wherein the adhesive sheet is adjacent to the liquid crystal cell. This can suppress blurring of the panel.

The present invention and its constituent elements, and specific embodiments and modes of the present invention will be described below. In the present application, "to" means that the numerical values described before and after "are included as the lower limit value and the upper limit value. In the present invention, the preferred embodiments can be arbitrarily modified and implemented without departing from the scope of the claims and their equivalents.

[ summary of the optical film of the invention ]

The optical film of the present invention is an optical film comprising a cycloolefin resin having an ethylene compound at least in a copolymerization component, wherein the optical film has a moisture permeability (40 ℃ C., 95% RH) of 0.1 to 60 g/(m) ² 24 h), the optical film having a roughened surface on one side, wherein the roughened surface has an external haze of 0.02% or more and less than 0.10% on one side.

< roughened surface >

In the present invention, the roughened surface is a surface on one side of an optical film containing a cycloolefin resin (containing an ethylene compound in a copolymer component) as a main component, and is a surface having high single-sided external haze when single-sided external haze is measured. When the film has a laminated structure, the surface of the optical film having the cycloolefin resin (containing an ethylene compound in the copolymerized component) as a main component is a roughened surface of the present patent, and the surface made of another resin is not a roughened surface even when the external haze on one side is high.

The roughened surface may be formed by press molding using a mold, plasma etching, sand blasting, sand paper treatment, casting under high humidity conditions, or the like.

From the standpoint of adjusting the single-sided external haze without increasing the internal haze, the cast film formation using a die, plasma etching, and high humidity conditions is preferable, and the die pressing using a die is most preferable.

In the method of molding with a mold, the single-sided external haze can be adjusted by changing the pressure and the pressing time when forming the roughened surface. Specifically, by extending the pressing time or increasing the pressure, the single-sided external haze value becomes large.

Therefore, in order to make the single-sided external haze of the roughened surface 0.02% or more and less than 0.10%, the pressing time is preferably in the range of 60 to 150 seconds, and the pressure is preferably in the range of 1 to 5 MPa.

In order to adjust the single-sided external haze of the roughened surface within the above range, the pressure and the pressing time of the die-based pressing may be adjusted: and cast film formation under high humidity conditions based on adjustment of electron density by plasma etching. The electron density is preferably, for example, 1×10 ¹⁰ ～1×10 ¹¹ cm ^-3 Within a range of (2). The high humidity condition of the cast film is preferably in the range of 60 to 90% RH.

< Single-sided external haze >

In the present invention, the single-sided external haze means external haze on the roughened surface side calculated from the total haze, internal haze, and external haze of the non-roughened surface of the optical film by the following formula (1).

Formula (1): single-sided external haze = total haze- (internal haze + external haze of non-roughened side)

Specifically, the measurement was performed according to the following procedure.

(1) The optical film was conditioned at 23℃and 55% RH for 5 hours or more. Then, the total haze 1 of the obtained optical film was measured at a wavelength of 550nm by a haze meter (model NDH4000, manufactured by japan electric color corporation).

(2) Subsequently, glycerol (0.05 ml) was dropped onto the washed slide glass, the wet optical film was bonded to the glycerol so that no air bubbles entered and the roughened surface became the slide glass side, and the obtained laminate was set in the haze meter so that the optical film faced the photodetector, and haze a (external haze of the back surface opposite to the roughened surface) was measured.

(3) Glycerol (0.05 ml) was added dropwise to the optical film side of the obtained laminate, a cover slip was placed thereon, and the obtained laminate was set in the haze meter to measure the internal haze 2.

The haze obtained by the measurement was substituted into the following formula (2), and the single-sided external haze B of the roughened surface was measured.

Formula (2): single-sided external haze b=total haze 1- (internal haze 2 x haze a) of roughened surface

The measurement of the external haze B on one side of the roughened surface was performed 10 times, and the average value was calculated.

In the present invention, the single-sided external haze of the roughened surface is 0.02% or more and less than 0.10%, whereby the adhesion and high-humidity impact of the present invention can be improved.

The expression of the present invention is not clear, but it is considered that: by increasing the single-sided external haze, the surface area of the roughened surface is increased, whereby the absorption of moisture emitted from the adhesive sheet can be improved, and the adhesion to the adhesive sheet can be improved. On the other hand, it can be considered that: if the single-sided external haze is reduced, moisture is retained at the interface of the optical film and the adhesive sheet due to insufficient uneven surface for absorbing water. Therefore, the value of the single-sided external haze of the roughened surface is preferably 0.02 or more and less than 0.10, more preferably 0.02 or more and 0.08 or less, and particularly preferably 0.02 or more and 0.04 or less.

The ratio of the single-sided external haze of the roughened surface to the single-sided external haze of the back surface opposite to the roughened surface is preferably 1.1:1.0 or more and less than 10.0:1.0, from the viewpoint of better adhesion to the adhesive sheet and high blur suppression effect. In particular, the ratio is more preferably 2:1 to 4:1.

The value of the single-sided external haze of the back surface is preferably 0.002 to 0.020, particularly preferably 0.004 to 0.010.

< high Wet impact >

In the present invention, the high humidity impact means a phenomenon in which when the temperature is changed from a high humidity environment (40 ℃ and 95% rh) to an indoor environment (23 ℃ and 55% rh), moisture condensed is not released from the adhesive sheet in the liquid crystal display device to the outside air, but stays at the interface between the optical film having low moisture permeability and the adhesive sheet, and the panel is blurred.

< moisture permeability >

In the present invention, the moisture permeability was measured by placing the film to be measured at a temperature of 40℃and 95% RH for 24 hours according to the calcium chloride cup method described in JIS Z0208.

The optical film of the present invention has a moisture permeability (40 ℃ C., 95% RH) of 0.1 to 60 g/(m) ² 24 h), more preferably 3.90 to 20.0 g/(m) ² 24 h).

In order to make the moisture permeability within the above range, the type and film thickness of the resin constituting the optical film are preferably selected and used without any particular limitation.

< easy adhesion layer >

The optical film of the present invention has, on the back surface opposite to the roughened surface: an easy-to-adhere layer containing at least one of an acrylic resin, a vinyl resin, a urethane resin, and a polyester resin.

By providing the optical film with an easily adhesive layer, adhesion between the optical film and a polarizer described later can be improved.

As a material for forming the easy-to-adhere layer, there is given: acrylic resin, vinyl resin, polyurethane resin, polyester resin, preferably polyurethane resin.

The thickness of the adhesive layer is in the range of 0.02 to 2.00 mu m.

[ constitution of optical film ]

The optical film of the present invention is composed of a cycloolefin resin having an ethylene compound at least in a copolymerization component.

As shown in fig. 1, the optical film 100 has a roughened surface 101 on one surface and an easy-to-adhere layer 102 on the back surface opposite to the roughened surface 101.

As described later, such an optical film 100 is suitable for a polarizing plate 200. The polarizing plate 200 is formed by laminating at least a polarizing plate protective film 300, a polarizer 400, an optical film 100, and an adhesive sheet 500 in this order, wherein the adhesive sheet 500 is directly disposed on the roughened surface 101 on the surface of the polarizer 400 disposed on the easy-to-adhere layer 102 of the optical film 100.

1-1 cycloolefin resin

The cycloolefin resin has an ethylene compound in a copolymerization component, and is a copolymer of the ethylene compound and a cycloolefin monomer.

The cycloolefin monomer is preferably a cycloolefin monomer having a norbornene skeleton.

Cycloolefin monomers having a structure represented by the following general formula (A-1) or (A-2) are particularly preferred.

[ chemical formula 1]

General formula (A-1)

R of the formula (A-1) ¹ ～R ⁴ Independently represents a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a polar group. However, in addition to R ¹ ～R ⁴ All of them are hydrogen atoms, R is excluded ¹ And R is ² At the same time as hydrogen atoms, or R ³ And R is ⁴ And also becomes a hydrogen atom.

The hydrocarbon group having 1 to 30 carbon atoms is preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 5 carbon atoms. The hydrocarbon group having 1 to 30 carbon atoms may have a linking group containing a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom. Examples of such linking groups include 2-valent polar groups such as carbonyl groups, imino groups, ether linkages, silyl ether linkages, thioether linkages, and the like. Examples of the hydrocarbon group having 1 to 30 carbon atoms include methyl, ethyl, propyl, butyl and the like.

Examples of the polar group include carboxyl group, hydroxyl group, alkoxy group, alkoxycarbonyl group, allyloxycarbonyl group, amino group, amide group, and cyano group. Among them, carboxyl group, hydroxyl group, alkoxycarbonyl group and allyloxycarbonyl group are preferable, and alkoxycarbonyl group and allyloxycarbonyl group are preferable from the viewpoint of securing solubility at the time of solution film formation.

P of the general formula (A-1) represents an integer of 0 to 2. p is preferably 1 or 2.

[ chemical formula 2]

General formula (A-2)

R of the formula (A-2) ⁵ Represents a hydrocarbon group having a hydrogen atom and a carbon number of 1 to 5 or a carbon atomAlkylsilyl groups of 1 to 5 alkyl groups. Of these, a hydrocarbon group having 1 to 5 carbon atoms is preferable, and a hydrocarbon group having 1 to 3 carbon atoms is more preferable.

R of the formula (A-2) ⁶ Represents a hydrogen atom, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, a cyano group or a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom). Among them, carboxyl group, hydroxyl group, alkoxycarbonyl group and allyloxycarbonyl group are preferable, and alkoxycarbonyl group and allyloxycarbonyl group are more preferable from the viewpoint of securing solubility at the time of solution film formation.

P of the general formula (A-2) represents an integer of 0 to 2. p is preferably 1 or 2.

The cycloolefin monomer represented by the general formula (A-2) has an asymmetric structure. That is, the substituent R of the cycloolefin monomer represented by the general formula (A-2) ⁵ And R is ⁶ The symmetry of the molecule is low because only rings substituted on one side with respect to the symmetry axis of the molecule constitute carbon atoms. In the method for producing an optical film described later, since such cycloolefin monomer can promote diffusion and movement of the ultraviolet absorber and the antioxidant when the cast dope is dried, the distribution state of these components can be easily adjusted.

Specific examples of the cycloolefin monomer represented by the general formula (A-1) are shown in example compounds 1 to 14, and specific examples of the cycloolefin monomer represented by the general formula (A-2) are shown in example compounds 15 to 34.

[ chemical formula 3]

Examples of the copolymerizable monomer copolymerizable with the cycloolefin monomer include copolymerizable monomers ring-opened copolymerizable with the cycloolefin monomer and copolymerizable monomers addition-copolymerizable with the cycloolefin monomer, as long as the copolymerizable monomer contains an ethylene compound.

Examples of the ring-opening copolymerizable monomer include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, dicyclopentadiene.

Examples of the addition copolymerizable comonomer include an unsaturated double bond-containing compound, a vinyl-based cyclic hydrocarbon monomer, and a (meth) acrylate.

Examples of the unsaturated double bond-containing compound are olefin-based compounds having 2 to 12 carbon atoms (preferably 2 to 8), and examples thereof include ethylene, propylene, and butene.

Examples of the vinyl-based cyclic hydrocarbon monomer include vinyl-based monomers such as 4-vinyl-cyclopentene and 2-methyl-4-isopropenyl-cyclopentene. Examples of the (meth) acrylic acid ester include alkyl (meth) acrylates having 1 to 20 carbon atoms such as methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate and the like.

The cycloolefin resin described above is preferably commercially available as an example of the commercially available product, and is commercially available as trade names of ARTON (ARTON: registered trademark) G series, ARTON F series, ARTON R series, and ARTON RX series by JSR (corporation), and as trade names of ZEONOR (registered trademark) ZF14, ZF16, 1420R, 1020R, 1060R, and the like, ZEONEX (ZEONEX: registered trademark) 250, 280, 480R, E, R, F R, 330R, RS420, and the like by ZEONOR (corporation), and may be appropriately selected and used according to the purpose.

The cycloolefin resin can be obtained by a known method, for example, the method described in Japanese patent application laid-open No. 2008-107534, japanese patent application laid-open No. 2005-227606, and Japanese patent application laid-open No. 4466272.

Intrinsic viscosity [ eta ] of cycloolefin resin]inh is preferably 0.2 to 5cm ³ In the range of/g, more preferably 0.3 to 3cm ³ In the range of/g, it is more preferably 0.4 to 1.5cm ³ In the range of/g.

The number average molecular weight (Mn) of the cycloolefin resin is preferably 8000 to 100000, more preferably 10000 to 80000, and even more preferably 12000 to 50000. The weight average molecular weight (Mw) of the cycloolefin resin is preferably 20000 to 300000, more preferably 30000 to 250000, and even more preferably 40000 to 200000. The number average molecular weight and the weight average molecular weight of the cycloolefin resin can be measured by conversion to polystyrene by Gel Permeation Chromatography (GPC).

When the intrinsic viscosity [ eta ] inh, the number average molecular weight and the weight average molecular weight are within the above-mentioned ranges, the cycloolefin resin is excellent in heat resistance, water resistance, chemical resistance, mechanical properties and moldability as a film.

The cycloolefin resin has a glass transition temperature (Tg) of usually 110℃or higher, preferably in the range of 110 to 350℃and more preferably 120 to 250℃and still more preferably 120 to 220 ℃. When Tg is 110℃or higher, deformation under high-temperature conditions is easily suppressed. On the other hand, when Tg is 350 ℃ or lower, molding processing becomes easy, and deterioration of the resin due to heat during molding processing is also easily suppressed.

The content of the cycloolefin resin is preferably 70% by mass or more, more preferably 80% by mass or more, relative to the optical film.

1-2 ultraviolet absorber

An ultraviolet absorber is added to improve the durability of the optical film. Such an ultraviolet absorber is preferably a compound that absorbs ultraviolet rays of 400nm or less, specifically, a compound having a transmittance of light of 370nm wavelength of 10% or less, preferably 5% or less, and more preferably 2% or less.

Examples of the ultraviolet absorber include oxybenzophenone compounds, benzotriazole compounds, salicylate compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex salt compounds, inorganic powders, and high molecular ultraviolet absorbers. The ultraviolet absorber may be 1 or 2 or more kinds thereof may be combined.

Among them, benzotriazole-based compounds, benzophenone-based compounds and triazine-based compounds are preferable from the viewpoint of having good ultraviolet absorption ability, and benzotriazole-based compounds and benzophenone-based compounds are more preferable.

Examples of benzotriazoles include 5-chloro-2- (3, 5-di-sec-butyl-2-hydroxyphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6- (straight and side chain dodecyl) -4-methylphenol. Examples of the benzophenone-based compound include 2-hydroxy-4-benzyloxybenzophenone, 2, 4-benzyloxybenzophenone.

Examples of commercial products include Tinuvin series such as Tinuvin109, tinuvin171, tinuvin234, tinuvin326, tinuvin327, tinuvin328, and Tinuvin928, which are commercially available from BASF corporation.

The content of the ultraviolet absorber (total content in the optical film) is preferably 0.1 to 10% by mass relative to the cycloolefin resin, for example. When the content of the ultraviolet absorber is 0.1 mass% or more, the durability (particularly weather resistance) of the optical film can be sufficiently improved. If the content of the ultraviolet absorber is 10 mass% or less, the transparency of the optical film is not easily impaired. The content of the ultraviolet absorber is more preferably 0.5 to 5 mass%.

1-3 antioxidant (deterioration inhibitor)

In order to suppress deterioration of the optical film under high temperature and high humidity, an antioxidant may be added.

Examples of antioxidants include hindered phenolic compounds. Examples of hindered phenolic compounds include: 2, 6-di-tert-butyl-p-cresol, pentaerythritol-tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate ], 1, 6-hexanediol-bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 2, 4-bis- (N-octylthio) -6- (4-hydroxy-3, 5-di-tert-butylanilino) -1,3, 5-triazine, 2-thio-diethylene bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, N' -hexamethylenebis (3, 5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (3, 5-di-tert-butyl-4-hydroxybenzyl) isocyanate, and the like. The antioxidant may be 1 kind, or may be 2 or more kinds.

Among them, 2, 6-di-t-butyl-p-cresol, pentaerythritol-tetrakis [3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate ] are preferable.

The antioxidant may be used in combination with, for example, a hydrazine-based metal-inert agent such as N, N' -bis [3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionyl ] hydrazine, or a phosphorus-based processing stabilizer such as tris (2, 4-di-t-butylphenyl) phosphite.

The content of the antioxidant (total content in the optical film) is, for example, preferably in the range of 0.1 to 10 mass% relative to the cycloolefin resin. When the content of the antioxidant is 0.1 mass% or more, the durability (particularly weather resistance) of the optical film can be sufficiently improved. If the content of the antioxidant is 10 mass% or less, the transparency of the optical film is not easily impaired. The content of the antioxidant is more preferably in the range of 0.5 to 5 mass%.

At least one of the ultraviolet absorber and the antioxidant is preferably unevenly distributed on the roughened surface by the solvent treatment of the optical film.

1-4 other ingredients

The optical film may further contain other additives within a range not impairing the effects of the present invention. Examples of other additives include plasticizers, heat stabilizers, particulates (matting agents), surfactants, fluorine-based surfactants, and peeling aids.

(microparticles)

The fine particles can impart irregularities to the surface of the optical film and improve slidability. The particles may be inorganic particles or organic particles.

Examples of the inorganic fine particles include fine particles of inorganic oxides such as silica, titania, alumina, zirconia, and the like; particles of calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, and the like.

Examples of the organic fine particles include fine particles of silicone resin, fluororesin, (meth) acrylic resin, and the like. Among them, silica particles are preferable from the viewpoint of less possibility of haze generation and less coloration.

The average particle diameter of the fine particles is preferably in the range of 1 to 500nm, more preferably in the range of 5 to 300 nm. The slidability of the adhesive layer can be effectively improved by setting the average particle diameter to 1nm or more, and the haze can be suppressed to be low by setting the average particle diameter to 500nm or less. The average particle diameter of the fine particles was measured by a laser diffraction method, and a particle diameter (50% volume cumulative particle diameter D50) having a cumulative volume of 50% from the small diameter side was used as the measured particle diameter distribution.

The content of the fine particles may be 10 mass% or less with respect to the optical film.

1-5 physical Properties of optical films

(phase difference value)

Depending on the application, the optical film may obtain various phase difference values. For example, when the optical film is used as an optical film of a VA-mode or IPS-mode liquid crystal display device, the phase difference Ro in the in-plane direction and the phase difference Rth in the thickness direction measured in an environment where the measurement wavelength of the optical film is 590nm, 23 ℃, and 55% rh can satisfy the following relationship, for example.

0nm≤Ro≤300nm

-200nm≤Rth≤200nm

The retardation Ro in the in-plane direction of the optical film more preferably satisfies 50.ltoreq.Ro.ltoreq.250 nm, and still more preferably satisfies 50 nm.ltoreq.Ro.ltoreq.200 nm. The retardation Rth in the thickness direction of the optical film more preferably satisfies-150 nm.ltoreq.Rth.ltoreq.150 nm, and still more preferably satisfies-120 nm.ltoreq.Rth.ltoreq.120 nm.

Ro and Rth of the optical film are defined by the following formulas, respectively.

Formula (2 a): ro= (n) _x -n _y )×d

Formula (2 b): rth= ((n) _x +n _y )/2-n _z )×d

(wherein nx represents the refractive index in the in-plane slow axis direction of the optical film. N _y The refractive index of the optical film in the direction perpendicular to the in-plane slow axis is shown. n is n _z The refractive index in the thickness direction of the optical film is shown. d represents the thickness (nm) of the optical film. )

The determination of Ro and Rth of the optical film can be performed by the following method.

(1) The optical film was conditioned at 23℃under 55% RH for 24 hours. The average refractive index of the optical film was measured by an Abbe refractometer, and the thickness d was measured by a commercially available micrometer.

(2) The phase retardation Ro and Rth at 590nm of the measurement wavelength of the optical film after the humidity was measured by using an automatic birefringence meter Axo scanning (AxoScan Mueller Matrix Polarimeter: manufactured by AXOMETRIS Co.) at 23℃and 55% RH, respectively. Specifically, the following is described.

(i) Ro when light having a measurement wavelength of 590nm was incident parallel to the normal direction of the film surface was measured by Axo scanning.

(ii) Further, by Axo scanning, the phase difference R (θ) when light of a measurement wavelength of 590nm was incident at an angle θ (incident angle θ) with respect to the normal line of the surface of the sample piece was measured with the in-plane slow axis of the sample piece as the tilt axis (rotation axis). The phase difference R (θ) was measured at 6 points at 10 ° in the range of 0 ° to 50 °. The in-plane slow axis of the sample piece was confirmed by Axo scan.

(iii) From the measured Ro and R (θ), the average refractive index and thickness, axo scan calculates n _x 、n _y And n _z Rth of a measurement wavelength of 590nm is calculated based on the formula (2 b).

(thickness)

The thickness of the optical film is, for example, in the range of 10 to 200. Mu.m, preferably in the range of 10 to 100. Mu.m, more preferably in the range of 15 to 60. Mu.m, and even more preferably in the range of 15 to 30. Mu.m, although the thickness depends on the range of the Ro and Rth to be obtained.

[ method for producing optical film ]

The optical film of the present invention can be produced by the following steps: 1) A step of preparing a dope containing the cycloolefin resin and a solvent; 2) Casting the obtained dope on a support, and then drying and peeling off the dope to obtain a casting film; 3) Stretching the obtained casting film; and 4) drying the stretched casting film; 5) Cutting both ends of the obtained optical film, and embossing; 6) Forming a roughened surface on the optical film; and 7) a coiling step. Further, the step of forming the adhesive layer is preferably performed as needed.

1) (step of preparing dopant)

The cycloolefin resin is dissolved or dispersed in a solvent to prepare a dope.

The solvent used for the dope contains an organic solvent (good solvent) which can dissolve at least the cycloolefin resin. Examples of good solvents include: chlorine-based organic solvents such as methylene chloride; non-chlorine organic solvents such as methyl acetate, ethyl acetate, acetone, and tetrahydrofuran. Among them, methylene chloride is preferable.

The solvent for the dope may further comprise a poor solvent. Examples of poor solvents include: a linear or branched aliphatic alcohol having 1 to 4 carbon atoms. If the ratio of alcohol in the dopant is high, the film tends to gel and peel off from the metal support. Examples of the linear or branched aliphatic alcohol having 1 to 4 carbon atoms include: methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol. Among them, ethanol is preferable from the viewpoints of stability of the dopant, low boiling point, good drying property, and the like.

2) (step (casting step)

The resulting dope is cast onto a support. The casting of the dope may be performed by being ejected from a casting die.

The solvent is allowed to evaporate until the dope cast onto the support can be peeled off from the support by the peeling roller. As a method for evaporating the solvent, there may be mentioned: a method of blowing air to the cast dope, a method of conducting heat from the back surface of the support through a liquid, a method of conducting heat from the front and back surfaces through radiant heat, and the like.

Then, the casting film obtained after the solvent evaporation was peeled off by a peeling roller.

The amount of the solvent remaining in the casting film on the support at the time of peeling may be, for example, 50 to 120 mass% although it depends on the drying conditions, the length of the support, and the like. If the cast film is peeled off in a state where the amount of the residual solvent is large, the cast film is too soft, and the flatness is easily impaired at the time of peeling, and wrinkles and vertical streaks are easily generated due to the peeling tension, and therefore, the amount of the residual solvent at the time of peeling is determined in consideration of these points. The residual solvent amount is defined by the following formula.

Residual solvent amount (mass%) = (mass before heat treatment of the casting film-mass after heat treatment of the casting film)/(mass after heat treatment of the casting film) ×100

The heat treatment for measuring the amount of the residual solvent was performed at 115℃for 1 hour.

3) (drawing step)

The cast film peeled from the support is stretched.

The stretching may be performed based on the obtained optical characteristics, and is preferably performed in one or more directions of a width direction (TD direction), a conveyance direction (MD direction), and an oblique direction. For example, in the case of producing an optical film functioning as a λ/4 retardation film, stretching in an oblique direction is preferable.

The stretching ratio also depends on the desired optical properties, and is preferably in the range of 1.05 to 4.0 times, more preferably in the range of 1.5 to 3.0 times, for example, when used as a lambda/4 retardation film.

The draw ratio (times) is defined as the draw direction dimension of the film after drawing/the draw direction dimension of the film before drawing. In the case of biaxial stretching, the stretching ratios in the TD direction and the MD direction are preferably set to be the above stretching ratios.

The stretching temperature (drying temperature during stretching) is preferably (tg+2) to (tg+50) c, more preferably (tg+5) to (tg+30) c, when the glass transition temperature of the cycloolefin resin is Tg, as described above. If the stretching temperature is (Tg+2) DEG C or higher, the solvent is easily volatilized moderately, so that the stretching tension is easily adjusted to an appropriate range, and if it is (Tg+50) DEG C or lower, the solvent is not volatilized too much, so that the stretchability is not easily damaged. The stretching temperature is preferably the same as described above, and the atmosphere temperature such as the internal temperature of the stretching machine (a) is preferably measured.

The amount of the residual solvent in the film at the start of stretching is preferably in the same range as the amount of the residual solvent in the film at the time of peeling, for example, 20 to 30 mass%, more preferably 25 to 30 mass%.

Stretching of the film in the TD direction (width direction) can be performed by, for example, a method (tenter method) in which both ends of the film are fixed with clips and pins, and the distance between the clips and pins is widened in the traveling direction. Stretching of the film in the MD direction can be performed, for example, by a method (roll method) in which a circumferential speed difference is applied to a plurality of rolls, and the roll circumferential speed difference is used therebetween. In particular, in order to improve the flatness and dimensional stability of the film, a tenter system is preferred in which both end portions of the cast film are sandwiched by clips or the like and stretched. It is preferable to stretch in a direction obliquely crossing with respect to the MD direction and the TD direction by stretching the cast film in both directions (oblique stretching).

4) (drying step)

The stretched casting film is further dried to obtain an optical film.

The drying of the casting film may be performed, for example, while the casting film is being conveyed by a plurality of conveying rollers (for example, a plurality of conveying rollers arranged in a staggered manner as seen from the side). The drying means is not particularly limited, and hot air, infrared rays, heated rolls, or microwaves may be used. From the viewpoint of simplicity, hot air drying is preferable.

5) (step (shearing and embossing Process)

The two ends of the obtained optical film in the width direction were cut. The shearing of the two ends of the optical film may be performed by a slitter.

Then, embossing (knurling) is performed on both ends of the optical film in the width direction. Embossing may be performed by pressing heated embossing rolls to both ends of the optical film. Fine irregularities are formed on the surface of the embossing roller, and by pressing the embossing roller against both end portions of the optical film, irregularities are formed on both end portions. By such embossing, winding deviation and sticking (sticking of films) in the subsequent winding process can be suppressed as much as possible.

6) (roughened surface Forming step)

A roughened surface is formed on the sheared optical film. The roughened surface can be formed by molding using a mold, plasma etching, sand blasting, sand paper treatment, casting under high humidity conditions, or the like, and molding using a mold is most preferred.

In the method of molding with a mold, a roll-shaped mold is rotated, an optical film is made to travel in a rotation direction along an outer peripheral surface of the mold at a given pressure and time, and then the optical film is peeled from the mold, thereby forming a roughened surface.

Here, the single-sided external haze can be adjusted by changing the pressure and the pressing time by the mold, and the single-sided external haze value can be increased by extending the pressing time or increasing the pressure.

7) (step (winding step)

Then, the obtained optical film was wound to obtain a wound body.

That is, the optical film is wound around the winding core while being conveyed, thereby forming a roll. The winding method of the optical film may be any method using a winding machine that is generally used, and examples thereof include a constant torque method, a constant tension method, a taper tension method, a program tension control method in which internal stress is constant, and the like.

The winding length of the optical film in the winding body is preferably in the range of 1000 to 7200 m. The width of the optical film is preferably in the range of 1000 to 3000 mm.

(step of Forming an adhesive layer)

Further, if necessary, it is preferable to form an adhesive layer on the surface of the optical film opposite to the roughened surface.

Specifically, the easy-to-adhere layer may be formed by applying a discharge treatment to the surface on which the easy-to-adhere layer is formed, and applying a resin material to the surface on the side on which the discharge treatment is applied, after the step (casting step) of 2) and before the step (stretching step) of 3) (that is, before the casting film peeled from the support is stretched).

Examples of the resin material include an acrylic resin, a vinyl resin, a urethane resin, and a polyester resin, and a urethane resin is preferable.

The resin material is preferably coated as a liquid aqueous resin composition by mixing an acrylic resin, a urethane resin, an epoxy compound, adipic acid dihydrazide, or the like with water. The content of the resin material in the aqueous resin composition is preferably in the range of 1 to 50 mass%.

[ polarizer ]

The polarizing plate of the present invention is a polarizing plate comprising at least a polarizing plate protective film, a polarizer, an optical film and an adhesive sheet laminated in this order, wherein the optical film is the optical film of the present invention.

< adhesive sheet >

The adhesive sheet has an adhesive layer formed of an adhesive composition.

Examples of the pressure-sensitive adhesive sheet include: the pressure-sensitive adhesive sheet comprises a double-sided pressure-sensitive adhesive sheet having only a pressure-sensitive adhesive layer, a double-sided pressure-sensitive adhesive sheet having a base material and pressure-sensitive adhesive layers formed on both sides of the base material, at least one pressure-sensitive adhesive layer being a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition, a single-sided pressure-sensitive adhesive sheet having a base material and the pressure-sensitive adhesive layers formed on one side of the base material, and a pressure-sensitive adhesive sheet having a separator adhered to a surface of the pressure-sensitive adhesive layers of the pressure-sensitive adhesive sheets that is not in contact with the base material.

The adhesive composition preferably contains, for example, an acrylic adhesive main agent, a crosslinking agent, an antioxidant, and the like.

Examples of the acrylic pressure-sensitive adhesive main agent include a 4-hydroxybutyl acrylate unit (4-HBA), a butyl acrylate unit, and a methyl acrylate unit.

Examples of the crosslinking agent include toluene diisocyanate compounds and xylylene diisocyanate.

Examples of the antioxidant include hindered phenol antioxidants such as pentaerythritol-tetrakis (3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate) (IRGANOX 1010, manufactured by BASF JAPAN Co., ltd.), and phosphorus antioxidants such as tris (2, 4-di-t-butylphenyl) phosphite (IRAFOS 168, manufactured by BASF JAPAN Co., ltd.).

The acrylic adhesive main agent in the adhesive composition is preferably contained in the range of 10 to 90 mass%, the crosslinking agent is preferably contained in the range of 0.01 to 5.00 mass%, and the antioxidant is preferably contained in the range of 0.01 to 5.00 mass%.

(Water content)

In the pressure-sensitive adhesive sheet, the water content is preferably small in order to suppress the occurrence of high-humidity impact, and if the water content is small, poor adhesion is caused, so that a small amount of water is preferable in the pressure-sensitive adhesive sheet. Therefore, the water content of the pressure-sensitive adhesive sheet is preferably in the range of 3.0 to 10.0%, and particularly preferably in the range of 3.5 to 5.5%.

The water content of the adhesive sheet can be obtained by: an adhesive layer was formed on a polyester film having a thickness of 50. Mu.m, cut to 60 mm. Times.130 mm, and then the adhesive sheet was stuck to a polycarbonate having a thickness of 1mm cut to 70 mm. Times.150 mm, and the resultant was left standing at 40℃for 48 hours under a 95% RH atmosphere, and the increase in the mass of the adhesive was measured.

In order to make the water content of the pressure-sensitive adhesive sheet fall within the range of 3.0 to 10.0%, for example, the content of 4-hydroxybutyl acrylate unit (4-HBA) in the pressure-sensitive adhesive composition may be set within the range of 4.0 to 25 mass%.

(polarizer)

A typical polarizer is a polyvinyl alcohol polarizing film, which is known to pass only light having a polarization plane in a predetermined direction. Among the polyvinyl alcohol-based polarizing films, there are a film obtained by dyeing a polyvinyl alcohol-based film with iodine and a film obtained by dyeing with a dichroic dye.

The polyvinyl alcohol-based polarizing film may be a film obtained by uniaxially stretching a polyvinyl alcohol-based film and then dyeing the film with iodine or a dichroic dye (preferably a film obtained by further subjecting the film to a durability treatment with a boron compound); the film may be a film obtained by dyeing a polyvinyl alcohol-based film with iodine or a dichroic dye and then uniaxially stretching the film (preferably a film obtained by further subjecting the film to a durability treatment with a boron compound). The absorption axis of the polarizer is generally parallel to the direction of maximum stretching.

For example, ethylene-modified polyvinyl alcohols having an ethylene unit content of 1 to 4 mol%, a polymerization degree of 2000 to 4000, and a saponification degree of 99.0 to 99.99 mol% described in JP-A2003-248123, JP-A2003-342322, and the like can be used. Among them, an ethylene-modified polyvinyl alcohol film having a hot water shearing temperature of 66 to 73℃is preferably used.

The thickness of the polarizer is preferably in the range of 5 to 30. Mu.m, and more preferably in the range of 5 to 20. Mu.m, for the purpose of thinning the polarizing plate, etc.

When the optical film of the present invention is used as a λ/4 film, the angle between the slow axis in plane of the optical film of the present invention and the absorption axis of the polarizer is preferably in the range of 20 to 70 °, more preferably in the range of 30 to 60 °, and even more preferably in the range of 40 to 50 °. When the optical film of the present invention is used as a retardation film for VA, the slow axis in plane of the optical film of the present invention and the absorption axis of the polarizer may be substantially orthogonal.

The polarizer and the optical film are preferably bonded by an adhesive or an adhesive.

The adhesive may be an aqueous adhesive containing a polyvinyl alcohol resin or a polyurethane resin as a main component, or a photocurable adhesive containing a photocurable resin such as an epoxy resin as a main component. The adhesive may contain an acrylic polymer, a polysiloxane polymer, a polyester, a polyurethane, a polyether, and the like as a base polymer. Among them, the aqueous adhesive is preferable in that the affinity with the optical film of the present invention is good and strain due to water absorption is not easily generated.

Lamination of the polarizer and the optical film of the present invention can generally be performed by roll-to-roll (roll-to-roll).

(polarizer protective film)

The polarizer protective film is disposed on the surface of the polarizer opposite to the optical film.

Examples of the polarizer protective film include commercially available cellulose acylate films (e.g., kenicamantadine TAC KC6UA, KC8UX, KC4UX, KC5UX, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4FR-1, KC8UY-HA, KC8UX-RHA, KC8UE, KC4HR-1, KC4KR-1, KC4UA, KC6UA, manufactured by KONICAMINOLTA OPTO (Co., ltd.), and the like).

The thickness of the polarizer protective film is not particularly limited, but is preferably in the range of 10 to 100. Mu.m, more preferably in the range of 10 to 60. Mu.m, and particularly preferably in the range of 20 to 60. Mu.m.

[ liquid Crystal display device ]

The liquid crystal display device of the present invention is a liquid crystal display device in which the polarizing plate is attached to at least one surface of a liquid crystal cell, wherein the adhesive sheet is adjacent to the liquid crystal cell.

Fig. 2 is a schematic diagram showing an example of the basic structure of a liquid crystal display device. As shown in fig. 2, the liquid crystal display device 20 of the present invention includes a liquid crystal cell 30, a 1 st polarizing plate 40 and a 2 nd polarizing plate 50 sandwiching the liquid crystal cell 30, and a backlight 60.

The display mode of the liquid crystal cell 30 may be any of TN (Twisted Nematic), VA (Vistical Alignment), IPS (in-plane switching), in Plane Switching, and the like, for example. A liquid crystal cell for a mobile device, for example, an IPS mode is preferred. The VA mode is preferable for the liquid crystal cell for medium and large-sized applications.

The 1 st polarizing plate 40 is disposed on a surface of the liquid crystal cell 30 on the visual observation side, and includes a 1 st polarizer 41, a protective film 43 (F1) disposed on a surface of the 1 st polarizer 41 opposite to the liquid crystal cell, and a protective film 45 (F2) disposed on a surface of the 1 st polarizer 41 on the liquid crystal cell side.

The 2 nd polarizer 50 is disposed on the backlight side surface of the liquid crystal cell 30, and includes a 2 nd polarizer 51, a protective film 53 (F3) disposed on the liquid crystal cell side surface of the 2 nd polarizer 51, and a protective film 55 (F4) disposed on the opposite side surface of the 2 nd polarizer 51 from the liquid crystal cell.

The absorption axis of the 1 st polarizer 41 is preferably orthogonal to the absorption axis of the 2 nd polarizer 51.

The protective film 45 (F2) may be an optical film of the present invention. The easy-to-adhere layer of the optical film and the 1 st polarizer 41 are directly laminated. The in-plane slow axis of the protective film 45 (F2) may be substantially orthogonal to the absorption axis of the 1 st polarizer 41. The protective films 43 (F1), 53 (F3), and 55 (F4) may be, for example, the polarizer protective films.

In fig. 2, an example in which the protective film 45 (F2) is the optical film of the present invention is shown, but the present invention is not limited thereto, and 53 (F3) may be the optical film of the present invention. For example, in the case where the protective film 53 (F3) is the optical film of the present invention, it is preferable that a roughened surface is formed on the liquid crystal cell side surface of the protective film 53 (F3), and an adhesive sheet is provided between the roughened surface and the liquid crystal cell. Further, it is preferable to form an adhesive layer on the surface opposite to the roughened surface.

As the optical film of the present invention as the protective film 45 (F2), the moisture permeability (40 ℃ C., 95% RH) is set to 0.1 to 60 g/(m) ² 24 h), the optical film having a roughened surface on one side, the roughened surface being single-sidedThe surface external haze is 0.02% or more and less than 0.10%, so that the roughened surface side has high single-surface external haze and large surface roughness, and the contact area with the adhesive sheet becomes large, so that the adhesive force is improved, and the absorption amount of moisture emitted from the adhesive sheet is increased. As a result, the liquid crystal display device using the optical film of the present invention can suppress blurring of the panel.

Examples

The present invention will be specifically described below by way of examples, but the present invention is not limited thereto. In the following examples, unless otherwise specified, the operation was performed at room temperature (25 ℃). In addition, "%" and "parts" mean "% by mass" and "parts by mass", respectively, unless otherwise specified.

[ preparation of adhesive composition (A) ]

To 100 parts by mass of an acrylic adhesive main agent having 4.5% by mass of 4-hydroxybutyl acrylate unit (4-HBA) and 60% by mass of butyl acrylate unit and 35.5% by mass of methyl acrylate unit, 0.3 parts by mass of toluene diisocyanate compound (manufactured by NIPPON POLYURETHANE INDUSTRY Co., ltd., COLLNETL) as a crosslinking agent, 0.7 parts by mass of pentaerythritol-tetrakis (3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate) (manufactured by BASF JAPAN Co., IRGANOX 1010) as a hindered phenol antioxidant, and 0.5 parts by mass of tris (2, 4-di-t-butylphenyl) phosphite (manufactured by BASF JAPAN Co., IRAFOS 168) as a phosphorus antioxidant were blended to obtain an adhesive composition (A).

[ preparation of adhesive composition (B) ]

97 parts by mass of N-butyl acrylate (N-BA), 2 parts by mass of N-vinylpyrrolidone (NVP), 1 part by mass of 1, 4-cyclohexanedimethanol monoacrylate (CHDMMA) and 100 parts by mass of ethyl acetate were charged into a reaction apparatus equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube, and the temperature was raised to 70℃while introducing nitrogen gas.

Then, 0.05 part by mass of azobisisobutyronitrile was added thereto, and the heating and cooling were repeated so that the temperature of the content in the flask was maintained at 70 to 71℃to react for 4 hours. After azobisisobutyronitrile was added for 1 hour, 50 parts by mass of ethyl acetate was added dropwise over about 1 hour. After the completion of the reaction, ethyl acetate was further added to obtain a (meth) acrylic polymer having a weight-average molecular weight (Mw) of 180 ten thousand and a weight-average molecular weight/number-average molecular weight (Mw/Mn) of 6.0.

An adhesive composition (B) was obtained by mixing 0.2 parts by mass of an isocyanate-based crosslinking agent (TD-75: manufactured by Ming's chemical Co., ltd.) in terms of the solid content and 0.2 parts by mass of a silane-based coupling agent (KBM-403: manufactured by Xin Yue chemical Co., ltd.) in terms of the solid content with 100 parts by mass of the solid content of the (meth) acrylic polymer.

[ preparation of adhesive compositions (C), (D) and (E) ]

The amounts of 4-hydroxybutyl acrylate units (4-HBA) in the adhesive were changed in the same manner as in the production of the adhesive sheet (A), to obtain adhesive compositions (C), (D) and (E) having water contents shown in Table I below. The water content was calculated by the above method.

TABLE 1

TABLE I

[ production of polarizing plate with adhesive layer ]

Each of the adhesive compositions thus prepared was coated on a PET film after the release treatment so that the thickness after drying was 25 μm, and dried at 90 ℃ for 3 minutes to form an adhesive layer, and adhesive sheets (a) to (E) were prepared.

Then, samples 1 to 52 of the polarizing plates with the adhesive layers were produced by sequentially bonding (optical film)/(polarizer)/(polarizing plate protective film) to each adhesive sheet from the side near the adhesive layer and curing the adhesive sheet at 23℃under 50% RH for 7 days.

The polarizer was prepared as follows.

A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature 110 ℃ C., stretching ratio 5 times), immersed in an aqueous solution composed of 0.075g of iodine, 5g of potassium iodide, and 100g of water for 60 seconds, and then immersed in an aqueous solution composed of 6g of potassium iodide, 7.5g of boric acid, and 100g of water at 68 ℃. And (3) washing and drying the immersed film to obtain the polarizer.

The lamination of the polarizer and the optical film was performed such that the transmission axis of the polarizer and the slow axis of the optical film were oriented at 45 °.

Further, as the polarizer protective film, there is used: the alkali-saponified Kenicamada TAC film KC4UAH (Kenicamada, inc.). The following optical films were used for each of samples 1 to 52.

Sample 1

< optical film 1>

The optical film 1 used was commercially available "ZEONOR1420R" (manufactured by japan ZEON corporation). The following table describes "resin a".

[ sample 2]

< production of optical film (A)

Pellets of a resin comprising a cycloolefin polymer (glass transition temperature 137 ℃ C.; ZEONOR1420R, manufactured by Japanese ZEON Co., ltd., hereinafter referred to as "resin B") were dried at 100℃for 5 hours. Then, the dried resin pellets were fed to a uniaxial extruder. After the resin was melted in an extruder, it was extruded in a sheet form from a T-die through a polymer tube and a polymer filter onto a casting drum (casting drum) and cooled. Thus, an optical film (A) having a thickness of 100 μm and a width of 500mm was obtained.

< production of optical film 2 >

The two ends of the obtained optical film (a) were held by a clip using a tenter type transverse stretching machine, and were continuously uniaxially stretched at a stretching temperature of 155 ℃ and a stretching ratio of 2.5 times, and further the left and right ends were cut and removed. Thus, an optical film 2 having a thickness of 40 μm and a width of 1250mm was obtained.

[ sample 3]

< manufacture of mold >

An aluminum ingot having a purity of 99.99% was cut into a cylindrical aluminum substrate having an outer diameter of 200mm, an inner diameter of 155mm and a length of 1250mm and having no rolling marks, and subjected to a feather cloth polishing treatment, followed by electrolytic polishing in a perchloric acid/ethanol mixed solution (volume ratio=1/4) to thereby mirror the aluminum substrate.

The obtained aluminum substrate was anodized in a 0.3M oxalic acid aqueous solution at a direct current of 35V and a temperature of 16℃for 10 minutes. Then, the aluminum substrate was immersed in a 6 mass% phosphoric acid/1.8 mass% chromic acid mixed aqueous solution to remove the oxide film.

The obtained aluminum substrate was anodized in a 0.3M oxalic acid aqueous solution at a direct current of 35V and a temperature of 16℃for 30 seconds.

The obtained aluminum substrate having the oxide film formed thereon was immersed in a 5 mass% phosphoric acid aqueous solution at 30 ℃ for 8 minutes, and subjected to pore diameter expansion treatment (pore diameter expansion treatment step). Then, the aluminum substrate was anodized in a 0.3M oxalic acid aqueous solution at a dc of 35V and a temperature of 16 ℃ for 30 seconds (oxide film growth step). The pore diameter expansion treatment step and the oxide film growth step were repeated 4 times in total, and finally the pore diameter expansion treatment step was performed to obtain a roll-shaped mold having anodized aluminum formed on the surface thereof, wherein the roll-shaped mold was designed to have pores having a substantially conical shape with an average interval of 50nm and a depth of 100 nm.

< preparation of optical film with roughened surface >

The obtained roll mold was rotated, and the optical film 2 was made to travel along the outer peripheral surface of the mold in the rotational direction at a pressure of 1MPa and for a time of 60 seconds. Then, the optical film 3 was obtained by peeling from the mold.

[ samples 4 to 6]

< preparation of optical film with roughened surface >

The obtained roll mold was rotated, and the optical film 2 was made to travel along the outer peripheral surface of the mold in the rotation direction at the pressure and time shown in table II below. Then, the optical films 4 to 6 were obtained by peeling from the mold.

TABLE 2

Table II

[ samples 7 to 14]

< production of optical film 7 >

Pellets of a resin (glass transition temperature: 137 ℃ C.; japanese ZEON Co., ltd. "ZEONOR 1420R") (hereinafter referred to as "resin B") containing a cycloolefin polymer were dried at 100 ℃ C. For 5 hours. Then, the dried resin pellets were fed to a uniaxial extruder. After the resin was melted in an extruder, it was extruded in a sheet form from a T-die through a polymer tube and a polymer filter onto a casting drum, and cooled to prepare a 1000 μm thick film roll.

The two ends of the obtained raw film were held by a clip by using a tenter type transverse stretching machine, and were continuously and transversely uniaxially stretched at a stretching temperature of 155 ℃ at a stretching ratio of 2.5 times, and further, the left and right ends were cut and removed so that the film width became 1250 mm. On one surface of the obtained optical film, a mold-based surface treatment was performed at a pressure of 1MPa and a pressing time of 60 seconds, similarly to the optical film 3, to form a roughened surface, thereby obtaining an optical film 7.

< production of optical films 8 to 12 >

Similarly to the optical film 7, the thickness of the rolled film was changed to table III below, both ends of the obtained film were held by a clip using a tenter type transverse stretching machine, and the film was continuously and uniaxially stretched in the transverse direction at a stretching temperature of 155 ℃ at a stretching ratio of 2.5 times, and further, the left and right ends were cut so that the film width became 1250mm and removed. On one surface of the obtained optical film, a mold-based surface treatment was performed at a pressure of 1MPa and a pressing time of 60 seconds, similarly to the optical film 3, to form roughened surfaces, thereby obtaining optical films 8 to 12.

TABLE 3

TABLE 11I

< production of optical films 13 and 14 >

The raw material was changed to ARTON G7810 (ARTON-G7810 (manufactured by JSR corporation) (hereinafter, referred to as "resin C") and the thickness of the raw film was changed to that shown in table IV below in the same manner as in the optical film 7, and the surface treatment by a mold was performed under a pressure of 1MPa and a pressing time of 60 seconds in the same manner as in the optical film 3 to form roughened surfaces, thereby producing the optical films 13 and 14.

ARTON G7810 is a cycloolefin resin (copolymer of a monomer represented by the general formula (a-2) and an ethylene compound), and has a weight average molecular weight mw=140000.

TABLE 4

Table IV

[ samples 15 to 19]

< production of optical film 15 >

Pellets of a resin (glass transition temperature 137 ℃ C.; ZEONOR1420R, manufactured by Japanese ZEON Co., ltd.) (hereinafter, referred to as "resin B") containing a cycloolefin polymer were dried at 100℃for 5 hours. Then, the dried resin pellets were fed to a uniaxial extruder. After the resin was melted in an extruder, it was extruded in a sheet form from a T-die onto a casting drum through a polymer tube and a polymer filter, and cooled to prepare a 50 μm thick film roll.

Then, both ends of the obtained film were held by a clip using a tenter type transverse stretching machine, were continuously and transversely uniaxially stretched at a stretching temperature of 155 ℃ at a stretching ratio of 2.5 times, and further, the left and right ends were cut and removed so that the film width became 1250 mm.

On one surface of the obtained optical film, a mold-based surface treatment was performed at a pressure of 1MPa and a pressing time of 60 seconds, similarly to the optical film 3, to form a roughened surface, thereby obtaining an optical film 15.

< production of optical films 16 to 19 >

The thickness of the raw film was changed to be shown in the following table V similarly to the optical film 15, both ends of the obtained film were clamped by a clamp using a tenter type transverse stretching machine, the stretching temperature was 155 ℃, the stretching magnification was changed to be shown in the following table V, and the film was continuously and uniaxially stretched in the transverse direction, and further, the portions at both left and right ends were cut and removed so that the film width became 1250 mm.

On one surface of the obtained optical film, a mold-based surface treatment was performed at a pressure of 1MPa and a pressing time of 60 seconds, similarly to the optical film 3, to form roughened surfaces, thereby obtaining optical films 16 to 19.

TABLE 5

Table V

[ sample 20]

< production of optical film 20 >

As the optical film 20, commercially available e-ZB12 (manufactured by ZEON Co., ltd.) was used. The following table is referred to as "resin D".

Sample 21

< production of optical film 21 >

(preparation of Material Y)

An aqueous dispersion of 100 parts by mass (amount of polyurethane as mass in the aqueous dispersion) (trade name "ADEKA bontigter," manufactured by ADEKA corporation, containing a carbonate polyurethane having a polar group as the polymer Yp, glass transition temperature of-16 ℃) was mixed with 10 parts by mass of an epoxy compound (trade name "DENACOL EX-521," manufactured by nase CHEMTEX corporation), 6 parts by mass of adipic dihydrazide, and water as the material Y to obtain a liquid aqueous resin composition having a solid content of 22%.

(lamination of easy-to-bond layer)

The surface of one side of the prepared optical film (A) (resin containing cycloolefin polymer (ZEONOR 1420R manufactured by ZEON Co., ltd.) was subjected to discharge treatment using a corona treatment apparatus (manufactured by CHUN motor Co.) under conditions of an output of 500W, an electrode length of 1.35m, and a transport speed of 15m/min, and the surface of the one side of the optical film (A) subjected to discharge treatment was coated with the material Y so that the dry film thickness was 2.0. Mu.m using a roll coater.

Then, both ends of the optical film (a) were held by a clip by using a tenter type transverse stretching machine, continuously subjected to transverse uniaxial stretching at a stretching temperature of 155 ℃ and a stretching ratio of 2.5 times, and further, left and right end portions were cut and removed. Thus, the step of drying and curing the coated material Y and the step of stretching the optical film (a) were carried out together, and a coating layer (an easy-to-adhere layer made of a polyurethane resin) was laminated on the surface of the optical film 2, to obtain an optical film 21 having a total film thickness of 40 μm (a layer: coating layer=20:1) and a width of 1250 mm. In the resin column of the following table, it is described as "resin E".

[ samples 22 to 25]

< production of optical films 22 to 25 >

The roll-shaped mold used for producing the optical film 3 was rotated, and the optical film 21 was made to travel along the outer peripheral surface of the mold in the rotational direction at the pressure and time shown in table VI below. Then, the optical films 22 to 25 were obtained by peeling from the mold.

TABLE 6

Table VI

[ samples 26 to 33]

< production of optical film 26 >

Pellets of a resin (glass transition temperature 137 ℃ C.; ZEONOR1420R, manufactured by Japanese ZEON Co., ltd.) containing a cycloolefin polymer were dried at 100 ℃ C. For 5 hours. Then, the dried resin pellets were fed to a uniaxial extruder. After the resin was melted in an extruder, it was extruded in a sheet form from a T-die onto a casting drum through a polymer tube and a polymer filter, and cooled to prepare a 1000 μm thick film roll.

The surface of one side of the film was subjected to discharge treatment using a corona treatment apparatus (manufactured by spring motor company) under conditions of an output of 500W, an electrode length of 1.35m, and a transport speed of 15 m/min. On the surface of the rolled film on the side subjected to the discharge treatment, the material Y was coated with a roll coater so that the dry film thickness was 2.0 μm.

Then, both ends of the obtained raw film were held by a clip by using a tenter type transverse stretching machine, and were continuously and uniaxially stretched transversely at a stretching temperature of 155 ℃ at a stretching ratio of 2.5 times, and further, the left and right ends were cut so that the film width became 1250mm, and removed. Thus, the step of drying and curing the coated material Y and the step of stretching the raw film were carried out together, and the coated layer was laminated on the surface of the film, to obtain an optical film 26 having a total film thickness of 400 μm (a layer: coated layer=20:1).

< production of optical films 27 to 31 >

The thickness of the rolled film was changed to that shown in table VII below in the same manner as the optical film 26, both ends of the obtained film were clamped by a clamp using a tenter type transverse stretching machine, and the film was continuously and uniaxially stretched in the transverse direction at a stretching temperature of 155 ℃ at a stretching ratio of 2.5 times, and further, the left and right ends were cut and removed so that the film width became 1250 mm. The optical films 27 to 31 were obtained by performing the same surface treatment as the optical film 3 on one surface of the obtained optical film to form roughened surfaces.

TABLE 7

Table VII

< production of optical films 32 and 33 >

The optical films 32 and 33 were produced by changing the raw material to ARTON G7810 (manufactured by JSR corporation) (hereinafter referred to as "resin C") and changing the thickness of the roll film to that shown in table VIII below in the same manner as the optical film 26, coating and stretching the material Y on the surface of the roll film, and then performing the same surface treatment as the optical film 3 to form roughened surfaces.

TABLE 8

Table VIII

Sample 34

< production of optical film 34 >

The material Y described in the optical film 21 was coated on the optical film (a) by using a roll coater, and an optical film 34 having a total film thickness of 20 μm (a layer: coating layer=20:1) was obtained by using a tenter type transverse stretching machine. On the surface of the obtained optical film 34 facing the coating layer, a mold-based surface treatment was performed at a pressure of 1MPa and a pressing time of 60 seconds, similarly to the optical film 3, to obtain a roughened surface.

[ sample 35]

< production of optical film 35 >

100 parts by mass of dipentaerythritol hexaacrylate (manufactured by Japanese chemical Co., ltd., KAYARAD DPHA) and 4 parts by mass of 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropan-1-one (IRGACURE 907 manufactured by CIBA SPECIALTY CHEMICALS) were dissolved in toluene using a dispersion mill. The obtained coating liquid was coated on an optical film (a) by a roll coater, and after removing the solvent by an oven, an easy-to-adhere layer was prepared by irradiating with ultraviolet rays.

Next, 80 parts by mass of polymethyl methacrylate (PMMA) resin (Dianal BR-85 manufactured by Mitsubishi chemical corporation) was dissolved in methyl ethyl ketone as an optional solid component, and 20 parts by mass of a crosslinked NBR rubber filler (XER-91 manufactured by JSR corporation, particle size 0.07 μm) was dispersed by a dispersing machine to obtain a coating liquid.

The obtained coating liquid was coated on the optical film (a) with a roll coater to obtain an optical film 35 having a total film thickness of 20 μm (layer a: coating layer=20:1).

On the surface of the obtained optical film 35 facing the coating layer, a mold-based surface treatment was performed at a pressure of 1MPa and a pressing time of 60 seconds, similarly to the optical film 3, to obtain a roughened surface.

[ sample 36]

< production of optical film 36 >

(Synthesis of vinyl aromatic resin)

Into a glass flask equipped with a stirrer, a condenser and a thermometer, 127.87g (1.23 mol) of styrene, 13.3g (0.136 mol) of maleic anhydride, 75g of toluene as a solvent, 0.7g (2.7 mmol) of 1,1' -azobis (cyclohexane-1-carbonitrile) as a radical initiator were charged, and the mixture was heated to 90℃to react for 15 hours. A part of the polymerization solution was taken out, and the reaction rate was measured, resulting in 85%. In addition, when the molecular weight was measured, mw=129900 and Mw/mn=2.00.

The resulting polymerization reaction solution was diluted with tetrahydrofuran, coagulated in a large amount of methanol, and the vinyl aromatic resin was recovered and purified, and dried in a vacuum drier at 80℃for 2 days.

(coating on optical film)

The obtained vinyl aromatic resin was dissolved in methyl ethyl ketone to prepare a coating solution having a resin concentration of 35%. The resulting solution was applied to an optical film (a) using a coater, dried at 50 ℃ for 10 minutes, dried at 80 ℃ for 10 minutes, and dried at 110 ℃ for 300 minutes to give an optical film 36 having a total film thickness of 20 μm (layer a: coating layer=20:1).

On the surface of the obtained optical film 36 facing the coating layer, a mold-based surface treatment was performed at a pressure of 1MPa and a pressing time of 60 seconds, similarly to the optical film 3, to obtain a roughened surface.

[ sample 37]

< production of optical film 37 >

The two ends of the obtained film (a) were held by a clip by using a tenter type transverse stretching machine, and were continuously uniaxially stretched at a stretching temperature of 155 ℃ and a stretching ratio of 2.5 times, and further, the left and right ends were cut and removed. Thus, an optical film 37 having a thickness of 40 μm and a width of 1250mm was obtained.

The pressure-sensitive adhesive sheet bonded to the obtained optical film 37 was changed from the pressure-sensitive adhesive sheet (a) to the pressure-sensitive adhesive sheet (B), and this was used as a sample 37.

Sample 38

< production of optical film 38 >

The roll mold used in the manufacture of the optical film 3 was advanced relative to the optical film 37 at a pressure of 1MPa and a time of 60 seconds. Then, the optical film 38 is obtained by peeling from the mold.

The pressure-sensitive adhesive sheet bonded to the obtained optical film 38 was changed from the pressure-sensitive adhesive sheet (a) to the pressure-sensitive adhesive sheet (B), and this was used as a sample 38.

[ samples 39 to 41]

< production of optical films 39 to 41 >

The roll-shaped mold used for producing the optical film 3 was rotated, and the optical film 37 was made to travel along the outer peripheral surface of the mold in the rotational direction at the pressure and time shown in table IX below. Then, the optical films 39 to 41 were obtained by peeling from the mold.

The adhesive sheets bonded to the obtained optical films 39 to 41 were changed from the adhesive sheet (a) to the adhesive sheet (B), and the obtained optical films were used as samples 39 to 41.

TABLE 9

Table IX

[ samples 42 to 46]

< production of optical film 42 >

Coating of the material Y described in sample 21 and stretching of the raw film were performed to obtain an optical film 42 having a total film thickness of 40 μm (layer a: coating layer=20:1) and a width of 1250 mm.

The pressure-sensitive adhesive sheet bonded to the obtained optical film 42 was changed from the pressure-sensitive adhesive sheet (a) to the pressure-sensitive adhesive sheet (B), and this was used as a sample 42.

< production of optical films 43 to 46 >

The roll-shaped mold used for producing the optical film 3 was rotated, and the optical film 42 was made to travel along the outer peripheral surface of the mold in the rotational direction at the pressure and time shown in table X below. Then, the optical films 43 to 46 were obtained by peeling from the mold.

The adhesive sheets bonded to the obtained optical films 43 to 46 were changed from the adhesive sheet (a) to the adhesive sheet (B), and the obtained optical films were used as samples 43 to 46.

TABLE 10

Table X

[ samples 47 to 49]

The pressure-sensitive adhesive sheets bonded to the optical film 3 were changed from the pressure-sensitive adhesive sheet (a) to pressure-sensitive adhesive sheets (C), (D) and (E), respectively, and samples 47 to 49 were obtained.

[ samples 50 to 52]

The pressure-sensitive adhesive sheets bonded to the optical film 3 were changed from the pressure-sensitive adhesive sheet (a) to pressure-sensitive adhesive sheets (C), (D) and (F), respectively, and samples 50 to 52 were obtained.

For each of the obtained samples, the thickness, the moisture permeability, the single-sided external haze of the roughened surface, the single-sided external haze of the back surface, and the like of the optical film were measured as follows, as shown in tables XI and XII below.

< measurement of moisture permeability >

The moisture permeability was measured by leaving the film to be measured at 40℃and 95% RH for 24 hours according to the calcium chloride cup method described in JIS Z0208.

< measurement of Single-sided external haze of roughened surface >

(2) Subsequently, glycerol (0.05 ml) was dropped onto the washed slide glass, the wet optical film was bonded to the glycerol so that no air bubbles entered and the roughened surface became the slide glass side, and the obtained laminate was set in the haze meter so that the optical film faced the photodetector, and haze a (single-sided external haze on the back surface) was measured.

The haze obtained by the measurement was substituted into the following formula, and the single-sided external haze B of the roughened surface was measured.

The formula: single-sided external haze b=total haze 1- (internal haze 2+haze a) of roughened surface

[ evaluation ]

< adhesion >

The resulting polarizing plate with an adhesive sheet was cut to a width of 25mm, and a test piece was prepared. The PET film subjected to the peeling treatment was peeled from the test piece, the exposed adhesive layer was laminated on the glass plate with a displacement of 1cm, and the displaced portion was used as a grip portion. After bonding, the mixture was held in an autoclave adjusted to 50 ℃ per 5atm for 20 minutes and pressure-bonded. After the press-bonding, the polarizing plate was left to stand at 40℃under 95% RH for 1 hour, and then stretched at an angle of 180℃with respect to the glass at a speed of 300mm/min, and the adhesion was measured by a universal tensile tester. The adhesive strength was evaluated based on the following criteria. The results are shown in tables XI and XII below.

(reference)

Very good: the optical film or the adhesive layer was broken and not peeled off, and the adhesive property was good even at 60℃under 95% RH.

And (3) the following materials: the optical film or the adhesive layer is broken and cannot be peeled off, and has good adhesion.

O: the optical film and the adhesive layer were partially peeled off, but the adhesion was good.

Delta: partial peeling occurs between the optical film and the adhesive layer, but is within a range where there is no problem.

X: the optical film and the adhesive layer were peeled off entirely, and the adhesion was poor.

< improvement of high Wet impact >

The resulting polarizing plate with an adhesive sheet was cut to a width of 25mm, and a test piece was prepared. The PET film subjected to the peeling treatment was peeled from the test piece, and the exposed adhesive layer was bonded to a glass plate. After bonding, the laminate was allowed to stand in a constant temperature and humidity tank at 40℃and 95% RH for 5 days, and then taken out, and evaluated according to the following criteria. The results are shown in tables XI and XII below.

(reference)

Very good: the panel is not blurred.

And (3) the following materials: the internal mold vanishes in 60 seconds.

O: the blur disappeared within 10 minutes.

Delta: the internal mold vanishes in 1 hour.

X: the blur does not disappear.

/>

As shown in the results, the polarizing plate of the present invention has better adhesion between the adhesive sheet (adhesive layer) and the optical film than the polarizing plate of the comparative example, and can suppress blurring of the panel.

[ liquid Crystal display device 20]

< preparation of liquid Crystal display device 20 >

As a liquid crystal display device, a liquid crystal television set "AQ-32AD5" manufactured by summer system was prepared. The polarizing plate on the visual observation side was peeled off from the apparatus, and the sample 20 was attached as a polarizing plate with an adhesive layer so that the adhesive sheet was adjacent to the liquid crystal cell, to obtain a liquid crystal display device 20.

< evaluation of liquid Crystal display device 20 >

When the obtained liquid crystal display device 20 was subjected to the checkered test, peeling occurred in all the patterns between the adhesive layer and the optical film, and the adhesiveness was poor. Further, the blurring in the liquid crystal display device did not disappear when left standing in a constant temperature and humidity tank at 40℃and 95% RH for 5 days.

[ liquid Crystal display device 43]

< evaluation of liquid Crystal display device 43 >

The liquid crystal display device 43 obtained in the same manner as the above was subjected to the checkered test for the liquid crystal display device 43 except that the sample 20 as the polarizing plate with the adhesive layer was changed to the sample 43 in the production of the liquid crystal display device 20, and as a result, peeling was not generated between the adhesive sheet (adhesive layer) and the optical film, and the adhesiveness was good. In addition, when left standing for 5 days in a constant temperature and humidity tank at 40℃and 95% RH, blurring was not generated in the liquid crystal display device.

Industrial applicability

The present invention can be used for an optical film capable of suppressing blurring of a panel without reducing the adhesive force with an adhesive sheet, a polarizing plate using the optical film, and a liquid crystal display device.

Symbol description

30 liquid Crystal cell

40 1 st polarizer

41 st polarizer

43 protective film (F1)

45 protective film (F2)

46 roughened surface

47 easy-to-adhere layer

48 adhesive sheet

50 # 2 polarizer

51 nd polarizer

53 protective film (F3)

55 protective film (F4)

60 backlight

100 optical film

101 roughened surface

102 easy-to-adhere layer

200 polarizer

300 polarizer protective film

400 polarizer

500 adhesive sheet

Claims

1. An optical film comprising a cycloolefin resin, wherein,

2. The optical film according to claim 1, wherein,

3. The optical film according to claim 1, wherein,

the optical film according to any one of claims 1 to 3.

5. The polarizing plate according to claim 4, wherein,

6. A liquid crystal display device comprising a liquid crystal cell and the polarizing plate according to claim 4 or 5 attached to at least one surface of the liquid crystal cell,

the adhesive sheet is adjacent to the liquid crystal cell.