TWI814019B - Optical film, polarizing plate and liquid crystal display device - Google Patents

Abstract

The optical film of the present invention is an optical film containing a cycloolefin resin, and is characterized in that the cycloolefin resin is a resin containing a vinyl compound as a copolymer component, and the moisture permeability of the optical film (40° C., 95% RH) is Within the range of 0.1~60g/(m ² ･24h), and has a roughened surface on one side, and the single-sided external haze of the roughened surface is 0.02% or more and less than 0.10%.

Description

Optical films, polarizing plates and liquid crystal display devices

The present invention relates to an optical film, a polarizing plate and a liquid crystal display device. In particular, it relates to an optical film that can suppress clouding of a panel without reducing the adhesive force with an adhesive sheet, a polarizing plate and a liquid crystal display device using the optical film. .

Polarizing plates used in image display devices such as TVs and smartphones have protective films laminated on both sides of the polarized photon through an adhesive layer. In addition, when bonding a polarizing plate and a liquid crystal cell, an adhesive sheet composed of an adhesive composition is widely used. In addition, in order to ensure the adhesiveness of the adhesive sheet, the adhesive sheet itself must contain water, and acid components such as carboxylic acid must be present.

In recent years, when transporting polarizing plates or image display devices overseas, durability in extreme environments of temperature or humidity is required. However, when the moisture permeability of the optical film bonded to the liquid crystal unit through the adhesive sheet is low, due to changes in the environment, moisture in the adhesive sheet will remain at the interface with the optical film, causing the so-called "high humidity impact" that causes cloudiness on the panel. problem.

Therefore, in order to solve the above problems, the technology disclosed in Patent Document 1 uses an adhesive sheet that does not contain an acid component such as carboxylic acid. Compared with one containing an acid component, the technology has higher thermal durability and wet heat durability, and has no Contains acid components that can reduce the moisture content of adhesive sheets and prevent high-humidity shock. However, when the adhesive sheet does not contain an acid component, the adhesive strength of the adhesive sheet is reduced, making it difficult to bond the polarizing plate. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2019-206629

[Problem to be solved by the invention]

The present invention was completed in view of the above-mentioned problems and situations. The problem to be solved is to provide an optical film that can suppress clouding of the panel without reducing the adhesive force with the adhesive sheet, a polarizing plate and a liquid crystal display using the optical film. device. [Means used to solve problems]

In order to solve the above-mentioned problems, the inventors of the present invention conducted research on the causes of the above-mentioned problems and found that the external haze on the roughened surface side of an optical film composed of a cycloolefin-based resin having a roughened surface on one surface is higher. The higher the adhesiveness, the higher the adhesive force between the optical film and the adhesive sheet containing the cycloolefin-based resin, and the more the haze of the panel is suppressed. Finally, the present invention is completed. That is, the above-mentioned problems related to the present invention are solved by the following means.

1. An optical film containing a cycloolefin resin, characterized in that the cycloolefin resin is a resin containing a vinyl compound as a copolymer component, and the moisture permeability (40°C, 95%RH) of the optical film is: Within the range of 0.1~60g/(m ² ･24h), and has a roughened surface on one side, and the single-sided external haze of the roughened surface is 0.02% or more and less than 0.10%.

2. The optical film according to item 1, wherein the ratio of the single-sided external haze on the roughened surface to the single-sided external haze on 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 item 1, wherein the back surface opposite to the roughened surface has an adhesive layer containing at least one of an acrylic resin, a vinyl resin, a polyurethane resin, and a polyester resin. Then layer.

4. A polarizing plate, which is a polarizing plate formed by laminating at least a polarizing plate protective film, a polarizer, an optical film and an adhesive sheet in this order, It is characterized in that the aforementioned optical film is the optical film described in any one of items 1 to 3.

5. The polarizing plate according to item 4, wherein the moisture content of the adhesive sheet is 10.0% or less under an environment of 40°C and 95%RH.

6. A liquid crystal display device in which the polarizing plate described in Item 4 or Item 5 is bonded to at least one side of a liquid crystal cell, The characteristic is that the adhesive sheet is adjacent to the liquid crystal unit. [Effects of the invention]

By the above means of the present invention, it is possible to provide an optical film that can suppress clouding of the panel without reducing the adhesive force with the adhesive sheet, and a polarizing plate and a liquid crystal display device using the optical film. Although the expression mechanism or action mechanism of the effect of the present invention has not yet been clarified, it is estimated as follows. It is speculated that in an optical film containing a cycloolefin-based resin with a roughened surface on one side, the higher the external haze of the single side on the roughened surface side, the greater the surface roughness of the roughened surface, and the smaller the contact area with the adhesive sheet. Increases the adhesion between the optical film containing cycloolefin resin and the adhesive sheet. Furthermore, it is speculated that by increasing the contact area, the amount of moisture released from the adhesive sheet can be absorbed, thereby suppressing the haze of the panel. Accordingly, in the present invention, the moisture permeability of the optical film (40°C, 95%RH) is set in the range of 0.1 to 60g/(m ² ･24h), and a roughened surface is provided on one side, and the aforementioned The external haze of one side of the roughened surface is set to be more than 0.02% and less than 0.10%. Since the external haze of the single side of the roughened surface is high, the surface roughness also increases, which increases the contact area with the adhesive sheet. Improve the bonding strength with the adhesive sheet. Furthermore, since the amount of moisture released from the adhesive sheet is increased, cloudiness of the panel can be suppressed.

The optical film of the present invention is an optical film containing a cycloolefin resin, and is characterized in that the cycloolefin resin is a resin containing a vinyl compound as a copolymer component, and the moisture permeability (40°C, 95%RH) of the optical film is 0.1~ Within the range of 60g/(m ² ･24h), and has a roughened surface on one side, and the single-sided external haze of the roughened surface is 0.02% or more and less than 0.10%. This feature is a technical feature common to or corresponding to each of the following embodiments.

As an embodiment of the present invention, the ratio of the single-sided external haze on the roughened surface and the single-sided external haze on the back surface opposite to the roughened surface is 1.1:1.0 or more and less than 10.0:1.0 , since the external haze on the single side of the roughened surface is high and the surface roughness is also increased, the adhesion force is further improved, and the amount of moisture released from the adhesive sheet is increased, which can reliably suppress the cloudiness of the panel. See better.

In addition, the back surface opposite to the roughened surface is provided with an easy-adhesion layer containing at least one of acrylic resin, vinyl resin, polyurethane resin, and polyester resin to improve the adhesion to the back surface. It's better from this point of view.

The optical film of the present invention is suitable for use in a polarizing plate, which is formed by laminating at least a polarizing plate protective film, a polarizer, an optical film and an adhesive sheet in this order. The polarizing plate preferably has a moisture content of the adhesive sheet of 10.0% or less in an environment of 40° C. and 95% RH, so as to reliably suppress clouding of the panel.

The polarizing plate of the present invention is suitable for use in a liquid crystal display device in which the polarizing plate is bonded to at least one side of a liquid crystal unit, and is characterized in that the adhesive sheet is adjacent to the liquid crystal unit. Thereby, clouding of the panel can be suppressed.

Hereinafter, the present invention, its constituent elements, and forms and aspects for implementing the present invention will be described. However, in this case, "~" is used in the sense that the numerical values written before and after it are included as the lower limit value and the upper limit value. In addition, in the present invention, as long as it does not deviate from the scope of the patent application and its equivalent range, preferred aspects can be arbitrarily modified and implemented.

[Outline of the optical film of the present invention] The optical film of the present invention is an optical film composed of a cycloolefin-based resin containing at least a vinyl compound as a copolymer component, and is characterized by the moisture permeability of the optical film (40° C., 95 %RH) is in the range of 0.1~60g/(m ² ･24h), has a roughened surface on one side, and the single-sided external haze of the roughened surface is 0.02% or more and less than 0.10%.

<Roughened surface> In the present invention, the roughened surface refers to the surface of one side of an optical film containing a cycloolefin-based resin (containing a vinyl compound as a copolymer component) as the main component. When measuring the single-sided external haze, it is the single-sided external surface. The face of those with high haze. When the film has a laminated structure, the surface of the optical film containing a cycloolefin resin (containing a vinyl compound as a copolymer component) as the main component is the roughened surface of this patent, and the surface made of other resins is the outer surface of one side. When the haze is high, the surface is not roughened. The aforementioned roughened surface can be formed by using mold embossing, plasma etching, sandblasting, sandpaper treatment, casting film forming under high humidity conditions, etc. From the perspective of adjusting the external haze of a single side without increasing the internal haze, it is better to use mold embossing, plasma etching, or casting film under high humidity conditions. It is best to use Mold embossing. When forming a roughened surface, the external haze of a single side can be adjusted by using the embossing method of the mold and changing the pressure or stamping time. Specifically, by increasing the stamping time or increasing the pressure, the single-sided external haze value is increased. Accordingly, in order to set the single-sided external haze of the roughened surface to be 0.02% or more and less than 0.10%, it is preferable to set the aforementioned punching time to be in the range of 60 to 150 seconds and the aforementioned pressure to be 1 to 5MPa within the range. In addition, in order to set the single-sided external haze of the roughened surface to the aforementioned range, in addition to adjusting the pressure and stamping time of the embossing by the mold mentioned above, the adjustment of the electron density by plasma etching or the Casting and film making under high humidity conditions. The electron density is preferably in the range of 1×10 ¹⁰ to 1×10 ¹¹ cm ^-3 , for example. In addition, as a high-humidity condition for film casting, it is preferable to set the relative humidity in the range of 60 to 90%RH.

＜Single side external haze＞ In the present invention, the single-sided external haze refers to the external haze on the roughened surface side calculated by the following formula (1) from the total haze, internal haze, and external haze of the non-roughened surface of the optical film. Haze. Formula (1): Single-sided external haze = full haze - (internal haze + external haze of non-roughened surface)

Specifically, the following procedures are used for measurement. (1) Humidify the optical film in an environment of 23°C and 55%RH for more than 5 hours. Then, the total haze 1 of the obtained optical film was measured with a haze meter (model NDH 4000, manufactured by Nippon Denshoku Co., Ltd.) at a wavelength of 550 nm. (2) Next, drop glycerol (0.05ml) on the cleaned glass slide, and use the above-mentioned humidity-adjusting optical film on it to make the roughened surface become one side of the glass slide so that no air bubbles enter. Glycerol is laminated, and the resulting laminate is placed on the haze meter described above, with the optical film facing the direction of the photodetector, and the haze A (external haze of the back surface opposite to the roughened surface) is measured. . (3) Drop glycerol (0.05 ml) on the optical film side of the obtained laminate, place a cover glass on it, set the obtained laminate on the haze meter mentioned above, and measure the internal haze 2. The haze obtained by the measurement is applied to the following formula (2), and the single-sided external haze B of the roughened surface is measured. Formula (2): Single-sided external haze B of roughened surface = full haze 1 - (internal haze 2 × haze A) Furthermore, the single-surface external haze B of the roughened surface was measured 10 times, and the average value was calculated.

In the present invention, the adhesive strength and high-humidity impact of the present invention can be improved by having the single-sided external haze of the roughened surface be 0.02% or more and less than 0.10%. Although the details of the performance of the present invention are not known, it is thought that by increasing the external haze on one side, the surface area of the roughened surface can be increased and the absorbency of moisture released from the adhesive sheet can be improved, thereby enabling Improves adhesion with adhesive sheets. On the other hand, it is thought that when reducing the external haze on one side, the uneven surface for absorbing water is insufficient, resulting in water retention at the interface between the optical film and the adhesive sheet. Therefore, the single-sided external haze value 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.

Furthermore, the ratio of the single-sided external haze on the roughened surface and the single-sided external haze on the back surface opposite to the roughened surface is 1.1:1.0 or more and less than 10.0:1.0, so that the sheet can be adhered to The adhesion becomes good, and the turbidity suppression effect is high, which is better. In particular, the above-mentioned ratio is more preferably 2:1 or more and 4:1 or less. Moreover, the single-sided external haze value of the back surface is preferably 0.002 or more and 0.020 or less, and particularly preferably 0.004 or more and 0.010 or less.

＜High humidity shock＞ In the present invention, the so-called high-humidity shock refers to the moisture that condenses from the adhesive sheet in the liquid crystal display device when it changes from a high-humidity environment (40°C, 95%RH) to an indoor environment (23°C, 55%RH). The gas is released and stays at the interface between the optical film with low moisture permeability and the adhesive sheet, causing turbidity on the panel.

<Moisture permeability> In the present invention, the moisture permeability is measured according to the calcium chloride-cup method described in JIS Z 0208, by leaving the film to be measured at a temperature of 40° C. and 95% RH for 24 hours. The moisture permeability (40°C, 95%RH) of the optical film of the present invention is in the range of 0.1~60g/( ^m2 ･24h), and more preferably in the range of 3.90~20.0g/( ^m2 ･24h). In order to set the moisture permeability within the above range, it is not particularly limited, but it is preferable to appropriately select the type and film thickness of the resin constituting the optical film.

＜Easy adhesion layer＞ The optical film of the present invention has an easy-adhesion layer containing at least one kind of acrylic resin, vinyl resin, polyurethane resin, and polyester resin on the back side opposite to the roughened surface. By having an easy-adhesion layer on the optical film, the adhesion between the optical film and the polarized photons described below can be improved. Examples of materials used to form the easily adhesive layer include acrylic resin, vinyl resin, polyurethane resin, and polyester resin, and polyurethane resin is preferred. The thickness of the easy-adhesive layer is preferably in the range of 0.02~2.00 μm.

[Constitution of optical films] The optical film of the present invention is composed of a cycloolefin-based resin containing a vinyl compound at least as a copolymer component. Moreover, as shown in FIG. 1 , the optical film 100 has a roughened surface 101 on one side, and an easy-adhesion layer 102 on the back surface opposite to the roughened surface 101 . Such an optical film 100 is suitable for use in the polarizing plate 200 as will be described later. The polarizing plate 200 is laminated in at least the order of the polarizing plate protective film 300, the polarizing photon 400, the optical film 100 and the adhesive sheet 500, and arranges one side of the polarizing photon 400 on the easy-adhesion layer 102 of the optical film 100, and The adhesive sheet 500 is directly placed on the roughened surface 101 .

1-1.Cycloolefin resin The cycloolefin-based resin contains a vinyl compound as a copolymer component, and is a copolymer of the vinyl compound and a cycloolefin monomer.

The cyclic olefin monomer is preferably a cyclic olefin monomer having a norbornene skeleton. In particular, a cyclic olefin monomer having a structure represented by the following general formula (A-1) or (A-2) is more preferred.

R ¹ to R ⁴ in the general formula (A-1) independently represent a hydrogen atom, a hydrocarbon group with 1 to 30 carbon atoms, or a polar group. However, excluding the case where all R ¹ to R ⁴ become hydrogen atoms, it is assumed that there is no case where R ¹ and R ² become hydrogen atoms at the same time, or R ³ and R ⁴ become hydrogen atoms at the same time.

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 further 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 divalent polar groups such as carbonyl groups, imine groups, ether bonds, silyl ether bonds, and thioether bonds. Examples of hydrocarbon groups having 1 to 30 carbon atoms include methyl, ethyl, propyl, butyl, etc.

Examples of polar groups include carboxyl, hydroxyl, alkoxy, alkoxycarbonyl, allyloxycarbonyl, amine, amide and cyano groups. Among them, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, and an allyloxycarbonyl group are preferred, and from the viewpoint of ensuring solubility during film formation from a solution, an alkoxycarbonyl group and an allyloxycarbonyl group are preferred.

p in general formula (A-1) represents an integer from 0 to 2. p is preferably 1 or 2.

R ⁵ in the general formula (A-2) represents a hydrogen atom, an alkylsilyl group having a hydrocarbon group having 1 to 5 carbon atoms or an alkyl group having 1 to 5 carbon atoms. Among them, a hydrocarbon group having 1 to 5 carbon atoms is preferred, and a hydrocarbon group having 1 to 3 carbon atoms is more preferred.

R ⁶ in general formula (A-2) represents a hydrogen atom, carboxyl group, hydroxyl group, alkoxycarbonyl group, allyloxycarbonyl group, amine group, amide group, cyano group or halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atoms). Among them, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, and an allyloxycarbonyl group are preferred, and from the viewpoint of ensuring solubility during film formation from a solution, an alkoxycarbonyl group and an allyloxycarbonyl group are more preferred.

p in general formula (A-2) represents an integer from 0 to 2. p is preferably 1 or 2.

The cycloolefin monomer represented by general formula (A-2) has an asymmetric structure. That is, the substituents R ⁵ and R ⁶ of the cycloolefin monomer represented by the general formula (A-2) have low symmetry of the molecule because only the ring constituting carbon atoms on one side are substituted with respect to the symmetry axis of the molecule. It is considered that such a cyclic olefin monomer can promote the diffusion and movement of ultraviolet absorbers or antioxidants when drying the casting solution in the optical film manufacturing method described below, making it easier to adjust the distribution state of these components.

Specific examples of the cycloolefin monomer represented by the general formula (A-1) are shown in Exemplary Compounds 1 to 14, and specific examples of the cycloolefin monomer represented by the General Formula (A-2) are shown in the Exemplified Compounds 15 to 34.

Examples of copolymerizable monomers copolymerizable with cycloolefin monomers include copolymerizable monomers capable of ring-opening copolymerization with cycloolefin monomers and copolymers capable of addition copolymerization with cycloolefin monomers. Sexual monomer.

Examples of ring-opening copolymerizable copolymerizable monomers include cyclic olefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene.

Examples of copolymerizable monomers capable of addition copolymerization include compounds containing unsaturated double bonds, vinyl cyclic hydrocarbon monomers, and (meth)acrylic acid esters. Examples of compounds containing unsaturated double bonds are olefin compounds having 2 to 12 carbon atoms (preferably 2 to 8), and in this example include ethylene, propylene, and butene. Examples of vinyl cyclic hydrocarbon monomers include vinyl cyclopentene monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene. Examples of (meth)acrylates include alkanes having 1 to 20 carbon atoms such as methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and cyclohexyl (meth)acrylate. (meth)acrylate.

As the cycloolefin-based resin described above, commercially available products can be preferably used. As an example of the commercially available products, they are sold under the trade names of Arton (registered trademark) G series, Arton F series, Arton R series and Arton RX series from JSR Co., Ltd., and, It is commercially available from Japan Zeon Co., Ltd. under the trade names of Zeonor (registered trademark) ZF14, ZF16, 1420R, 1020R, 1060R, etc., Zeonex (registered trademark) 250, 280, 480, 480R, E48R, F52R, 330R, RS420, etc. These can also be appropriately selected and used according to the purpose.

Cycloolefin-based resins are all produced by known methods, and can be obtained by methods described in Japanese Patent Application Laid-Open No. 2008-107534, Japanese Patent Application Laid-Open No. 2005-227606, and Japanese Patent No. 4466272, for example.

The intrinsic viscosity [eta]inh of the cycloolefin-based resin is preferably in the range of 0.2 to 5 cm ³ /g, more preferably in the range of 0.3 to 3 cm ³ /g, and still more preferably in the range of 0.4 to 1.5 cm ³ /g within.

The number average molecular weight (Mn) of the cycloolefin-based resin is preferably 8,000 to 100,000, more preferably 10,000 to 80,000, still more preferably 12,000 to 50,000. The weight average molecular weight (Mw) of the cycloolefin-based resin is preferably 20,000 to 300,000, more preferably 30,000 to 250,000, still more preferably 40,000 to 200,000. The number average molecular weight or weight average molecular weight of the cycloolefin-based resin can be measured in terms of polystyrene by gel permeation chromatography (GPC).

When the intrinsic viscosity [eta]inh, number average molecular weight, and weight average molecular weight are within the above ranges, the heat resistance, water resistance, chemical resistance, mechanical properties, and molding processability of the cycloolefin-based resin as a film become good.

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

The content of the cycloolefin-based resin is preferably 70 mass% or more, more preferably 80 mass% or more, based on the optical film.

1-2.UV absorber UV absorbers are added to improve the durability of optical films. Such an ultraviolet absorber is preferably a compound that absorbs ultraviolet light of 400 nm or less. Specifically, a compound whose transmittance of light with a wavelength of 370 nm is 10% or less, preferably 5% or less, and more preferably 2% or less.

Examples of ultraviolet absorbers include oxybenzophenone-based compounds, benzotriazole-based compounds, salicylate-based compounds, benzophenone-based compounds, cyanoacrylate-based compounds, triazine-based compounds, Nickel complex salt compounds, inorganic powders, and polymer UV absorbers. The ultraviolet absorber may be one type, or two or more types may be combined.

Among them, benzotriazole-based compounds, benzophenone-based compounds, and triazine-based compounds are preferred because they have good ultraviolet absorbing energy, and benzotriazole-based compounds and benzophenone-based compounds are more preferred.

Examples of benzotriazole-based compounds include 5-chloro-2-(3,5-di-sec-butyl-2-hydroxyﾙphenyl)-2H-benzotriazole, (2-2H-benzene Triazol-2-yl)-6-(linear and side chain dodecyl)-4-methylphenol. Examples of benzophenone compounds include 2-hydroxy-4-benzyloxybenzophenone and 2,4-benzyloxybenzophenone.

Examples of commercially available products include Tinuvin series such as Tinuvin109, Tinuvin171, Tinuvin234, Tinuvin326, Tinuvin327, Tinuvin328, and Tinuvin928, which are all commercially available products manufactured by BASF.

The content of the ultraviolet absorber (total content in the optical film) is preferably 0.1 to 10% by mass relative to the cycloolefin-based resin, for example. If the content of the ultraviolet absorber is 0.1% by mass or more, the durability (especially weather resistance) of the optical film can be fully improved. If the content of the ultraviolet absorber is 10% by mass or less, it is difficult to impair the transparency of the optical film. The content of the ultraviolet absorber is preferably 0.5 to 5% by mass.

1-3. Antioxidant (deterioration prevention agent) Antioxidants can be added to inhibit the deterioration of optical films under high temperature and high humidity. Examples of antioxidants include hindered phenol compounds. Examples of hindered phenol compounds include 2,6-di-t-butyl-p-cresol, pentaerythritol-4[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3 -(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di -t-butylanilino)-1,3,5-triazine, 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propan acid ester], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N,N′-hexamethylenebis(3,5-di- t-butyl-4-hydroxy-hydroxysuccinimide (Hydroxysuccinimide), 1,3,5-trimethyl-2,4,6-gin (3,5-di-t-butyl-4- Hydroxybenzyl)benzene, ginseng-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanate, etc. The antioxidant may be one type, or two or more types may be combined. Among them, 2,6-di-t-butyl-p-cresol and pentaerythritol-4[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] are preferred. , triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate].

The antioxidant can be combined with a hydrazine-based metal inert agent such as N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propyl]hydrazine or ginseng (2, Use in combination with phosphorus-based processing stabilizers such as 4-di-t-butylphenyl) phosphite.

The content of the antioxidant (in the total content of the optical film) is preferably in the range of 0.1 to 10% by mass relative to the cycloolefin-based resin, for example. If the antioxidant content is 0.1% by mass or more, the durability (especially weather resistance) of the optical film can be fully improved. If the antioxidant content is 10% by mass or less, it is difficult to impair the transparency of the optical film. The antioxidant content is preferably in the range of 0.5 to 5% by mass.

At least one of the ultraviolet absorber and the antioxidant is preferably localized to the surface roughened by solvent treatment of the optical film.

1-4.Other ingredients The optical film may further contain other additives within the scope that does not impair the effects of the present invention. Examples of other additives include plasticizers, thermal stabilizers, fine particles (matting agents), surfactants, fluorine-based surfactants, and peeling aids.

(fine particles) Microparticles can impart unevenness to the surface of optical films and improve smoothness. The microparticles may be inorganic microparticles or organic microparticles. Examples of inorganic fine particles include fine particles of inorganic oxides such as silica, titanium dioxide, alumina, and zirconium oxide; or calcium carbonate, talc, clay, fired kaolin, fired calcium silicate, hydrated calcium silicate, silica Microparticles of aluminum phosphate, magnesium silicate, calcium phosphate, etc. Examples of organic fine particles include fine particles of silicone resin, fluororesin, (meth)acryl-based resin, and the like. Among them, silica particles are preferred because they are less likely to produce haze and have less coloring.

The average particle diameter of the fine particles is preferably in the range of 1 to 500 nm, more preferably in the range of 5 to 300 nm. By setting the average particle diameter to 1 nm or more, the smoothness of the easy-adhesion layer can be effectively improved, and by setting the average particle diameter to 500 nm or less, the haze can be suppressed to a low level. The average particle diameter of microparticles is determined by measuring the particle size distribution using a laser diffraction method. The measured particle size distribution is defined as the particle diameter at which 50% of the cumulative volume calculated from the small diameter side becomes 50% (50% volume cumulative diameter D50). The content of fine particles can be set to 10% by mass or less relative to the optical film.

1-5. About the physical properties of optical films (Phase difference value) Optical films can adopt various retardation values depending on their uses. For example, when the optical film is used as an optical film for a VA mode or IPS mode liquid crystal display device, the phase difference Ro in the in-plane direction and the phase difference Ro in the thickness direction are measured in an environment where the measurement wavelength of the optical film is 590 nm, 23°C, and 55% RH. The phase difference Rth can satisfy, for example, the following relationship. 0nm≦Ro≦300nm -200nm≦Rth≦200nm

The phase difference Ro in the in-plane direction of the optical film is preferably 50≦Ro≦250nm, and further preferably 50nm≦Ro≦200nm. The phase difference Rth in the thickness direction of the optical film preferably satisfies -150nm≦Rth≦150nm, and still more preferably satisfies -120nm≦Rth≦120nm.

Ro and Rth of the optical film are respectively defined by the following formulas. Formula (2a): Ro=(n _x -n _y )×d Formula (2b): Rth=((n _x +n _y )/2-n _z )×d (where nx represents the in-plane surface of the optical film The refractive index in the slow axis direction. _{n y} represents the refractive index in the direction perpendicular to the in-plane slow axis of the optical film. _{n z} represents the refractive index in the thickness direction of the optical film. d represents the thickness of the optical film (nm)).

The following methods can be used to measure Ro and Rth of optical films. (1) Humidify the optical film in an environment of 23°C and 55%RH for 24 hours. The average refractive index of the optical film was measured with an Abbe refractometer, and the thickness d was measured with a commercially available micrometer. (2) Measure the phase difference Ro and Rth of the humidity-conditioned optical film at a wavelength of 590 nm using an automatic birefringence meter Axo Scan (Mueller Matrix Polarimeter: manufactured by Axometrix Co., Ltd.) in an environment of 23°C and 55% RH. . Specifically, (i) Ro is measured with an Axo Scan when light with a measurement wavelength of 590 nm is incident parallel to the normal direction of the film surface. (ii) Furthermore, with Axo Scan, the in-plane slow axis of the sample piece is used as the tilt axis (rotation axis), and the incident measurement wavelength is measured from the angle θ (incident angle (θ)) with respect to the normal line of the surface of the sample piece. Phase difference R(θ) for 590nm light. The phase difference R(θ) is measured at 6 points every 10° in the range of 0° to 50°. The in-plane slow axis of the specimen was confirmed using Axo Scan. (iii) From the measured Ro and R(θ), and the aforementioned average refractive index and thickness, calculate Axo Scan as n _x , _ny and n _z , and calculate the measured wavelength of 590 nm according to the above formula (2b) Rth.

(thickness) Although the thickness of the optical film varies depending on the calculated ranges of Ro and Rth, for example, it is in the range of 10 to 200 μm, preferably in the range of 10 to 100 μm, more preferably in the range of 15 to 60 μm, and can be changed The best range is 15~30μm.

[Method for manufacturing optical film] The optical film of the present invention can be produced through the following steps: 1) preparing a stock solution containing the above-mentioned cycloolefin-based resin and a solvent; 2) casting the obtained stock solution onto a support, drying and peeling it off to obtain a cast film and 3) the step of stretching the obtained cast film, and further 4) the step of drying the stretched cast film, 5) the step of cutting both ends of the obtained optical film and performing embossing processing, 6) The step of forming a roughened surface on the optical film, and 7) The winding step. Moreover, it is preferable to perform the step of forming an easy-adhesion layer if necessary.

Regarding steps 1) (stock solution preparation steps) The cycloolefin-based resin is dissolved or dispersed in a solvent to prepare a stock solution.

The solvent used in the raw solution contains an organic solvent (good solvent) that can dissolve at least the cycloolefin-based resin. Examples of good solvents include chlorine-based organic solvents such as methylene chloride; or non-chlorine-based organic solvents such as methyl acetate, ethyl acetate, acetone, and tetrahydrofuran. Among them, methylene chloride is preferred.

The solvent used in the original solution may further contain a poor solvent. Examples of poor solvents include linear or branched aliphatic alcohols with 1 to 4 carbon atoms. When the ratio of alcohol in the original solution is increased, the film-like material is likely to gel, making peeling from the metal support easier. Examples of linear or branched aliphatic alcohols having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Among these, ethanol is preferred because the raw solution has a relatively low boiling point and stability, and has good drying properties.

Regarding steps 2) (casting steps) The obtained stock solution is cast onto a support. The raw liquid can be poured out from the casting mold.

The solvent can be evaporated until the original liquid cast on the support is peeled off from the support by a peeling roller. Methods for evaporating the solvent include blowing air onto the original solution for casting, transferring heat from the back of the support through liquid, and transferring heat from the front and back by radiant heat.

Then, the cast film obtained by evaporating the solvent is peeled off with a peeling roller.

The amount of residual solvent in the cast film on the support during peeling varies depending on the drying conditions, the length of the support, etc., but may be, for example, 50 to 120% by mass. When peeling off with a large amount of residual solvent, the cast film will be too soft, which will easily damage the flatness during peeling and easily cause wrinkles or vertical streaks due to peeling tension. Therefore, consider these points to determine the amount of residual solvent during peeling. . The amount of residual solvent is defined by the following formula.

Amount of residual solvent (mass %) = (mass of the cast film before heat treatment - mass of the cast film after heat treatment) / (mass of the cast film after heat treatment) × 100 The heat treatment when measuring the amount of residual solvent is performed at 115°C for 1 hour.

Regarding step 3) (stretching step) The cast film peeled off from the support is stretched.

Stretching may be performed in accordance with the obtained optical properties. It is preferable to stretch in one or more directions among the width direction (TD direction), the conveyance direction (MD direction), and the diagonal direction. For example, when producing an optical film used as a λ/4 retardation film, it is preferable to stretch the film in the diagonal direction.

The stretching ratio varies depending on the obtained optical properties, but when used as a λ/4 retardation film, for example, it is preferably in the range of 1.05 to 4.0 times, more preferably in the range of 1.5 to 3.0 times.

The stretching ratio (times) is defined as the stretching direction size of the film after stretching/the stretching direction size of the film before stretching. Furthermore, when performing biaxial stretching, it is preferable to set the above-mentioned stretching ratio for each of the TD direction and the MD direction.

The stretching temperature (drying temperature during stretching) is the same as above. When the glass transition temperature of the cycloolefin resin is defined as Tg, it is preferably (Tg+2) to (Tg+50)°C, more preferably (Tg +5)~(Tg+30)℃. When the stretching temperature is (Tg+2)°C or above, the solvent is easily volatilized appropriately, so it is easy to adjust the stretching tension to an appropriate range. When the stretching temperature is (Tg+50)°C or lower, the solvent is not excessively volatilized. Difficult to impair stretchability. The stretching temperature is the same as described above, and is preferably the ambient temperature at which (a) the temperature inside the stretching machine is measured.

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

The stretching of the film in the TD direction (width direction) can be carried out by, for example, fixing both ends of the film with clips or pins, and spreading the intervals between the clips or pins in the direction of extension (tenter method). The film can be stretched in the MD direction by a method (roller method) in which a plurality of rollers are provided with a difference in peripheral speed and the difference in peripheral speed between the rollers is used. In particular, the tenter method in which both ends of the cast film are held with clamps and stretched is preferred because it improves the flatness and dimensional stability of the film. The cast film is stretched in both the MD direction and the TD direction, preferably in a diagonally intersecting direction with respect to the MD direction and the TD direction (diagonal stretching).

About step 4) (drying step) The stretched cast film is further dried to obtain an optical film.

The cast film can be dried while conveying the cast film by, for example, a plurality of conveying rollers (for example, a plurality of conveying rollers arranged in a staggered pattern as seen from the side). The drying method is not particularly limited, but hot air, infrared rays, heating rollers or microwaves are used. From the viewpoint of simplicity, hot air drying is preferred.

Regarding steps 5) (cutting and embossing processing steps) Both ends in the width direction of the obtained optical film were cut. The cutting of both ends of the optical film can be performed by a slitting machine.

Next, embossing processing (knurling processing) is performed on both ends of the optical film in the width direction. The embossing process can be performed by pressing heated embossing rollers against both ends of the optical film. Fine unevenness has been formed on the surface of the embossing roller, and by pressing the embossing roller against both ends of the optical film, unevenness is formed at both ends. By such embossing processing, winding displacement or clogging (adherence of films to each other) in the next winding step can be suppressed as much as possible.

About step 6) (roughening surface formation step) A roughened surface is formed on the cut optical film. The roughened surface can be formed by embossing with a mold, plasma etching, sandblasting, sandpaper treatment, casting film under high humidity conditions, etc. The best method is embossing with a mold. In the embossing method using a mold, the roll-shaped mold is rotated, and the optical film is moved along the outer circumferential surface of the mold in the rotation direction with a specified pressure and time, and then the optical film is peeled off from the mold. Roughened surface. Here, by changing the pressure or stamping time caused by the mold, the single-sided external haze can be adjusted, and by extending the stamping time or increasing the pressure, the single-sided external haze value can be increased.

Regarding steps 7) (winding steps) Furthermore, the obtained optical film was wound up to obtain a roll body.

That is, the optical film is wound around a winding core while being transported to form a roller body. The optical film can be wound using a commonly used winding machine. There are tension control methods such as the constant torque method, the constant tension method, the taper tension method, and the programmed tension control method with constant internal stress.

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

About (easy-adhesive layer formation step) Moreover, if necessary, it is preferable to form an easy-adhesion layer on the surface opposite to the roughened surface of the optical film. Specifically, after the step of 2) (casting step) and before the step of 3) (stretching step), (that is, before stretching the cast film peeled off from the support), the easy-adhesion film can be formed. The surface of the layer is subjected to discharge treatment, and a resin material is applied to the surface on the side subjected to discharge treatment to form an easy-adhesion layer. Examples of the resin material include acrylic resin, vinyl resin, polyurethane resin, and polyester resin, and polyurethane resin is preferred. The aforementioned resin material is a mixture of acrylic resin, polyurethane resin, epoxy compound, adipic acid dihydrazine, etc. and water, and is preferably applied as a liquid aqueous resin composition. In addition, the content of the resin material in the water-based resin composition is preferably in the range of 1 to 50% by mass.

[Polarizing plate] The polarizing plate of the present invention is a polarizing plate formed by laminating at least a polarizing plate protective film, a polarizer, an optical film and an adhesive sheet in this order. The aforementioned 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 adhesive sheet include a double-sided adhesive sheet having only an adhesive layer, a base material, and adhesive layers formed on both sides of the base material, and at least one of the adhesive layers is an adhesive layer formed of an adhesive composition. Double-sided adhesive sheets with an adhesive layer, single-sided adhesive sheets having a base material and the above-mentioned adhesive layer formed on one side of the base material, and those that are not in contact with the base material of the adhesive layer on one side of the adhesive sheet The adhesive sheet attached to the divider is attached to the surface.

The adhesive composition is preferably composed of, for example, an acrylic adhesive main component, a cross-linking agent, an antioxidant, and the like. Examples of the acrylic adhesive base include 4-hydroxybutyl acrylate unit (4-HBA), butyl acrylate unit, and methyl acrylate unit. Examples of the cross-linking agent include toluene diisocyanate-based compounds, xylene diisocyanate, and the like. Examples of the antioxidant include hindered phenol antioxidants such as pentaerythritol-4 (3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate) (IRGANOX 1010, manufactured by BASF Japan). Phosphorus-based antioxidants such as ginseng (2,4-di-t-butylphenyl) phosphite (manufactured by BASF Japan, IRGAFOS168).

The acrylic adhesive main agent in the adhesive composition is preferably contained in the range of 10 to 90 mass %, the cross-linking 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 Contains within the range of ~5.00% by mass.

(moisture content) In order to suppress the occurrence of high-humidity shock, the adhesive sheet preferably contains a small amount of water. On the other hand, when the moisture content is small, poor adhesion may occur, so it is preferred that a large amount of the adhesive sheet contains water. Therefore, the moisture content of the 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 moisture content of the adhesive sheet is determined by forming an adhesive layer on a polyester film with a thickness of 50 μm, and after cutting it into 60 mm Let it stand for 48 hours in an environment of 40°C and 95%RH, and measure the mass increase of the adhesive to obtain it.

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

(polarized photon) Polarizers are components of light that only pass through the polarization plane in a certain direction. The currently known representative polarizers are polyvinyl alcohol-based polarizing films. Among polyvinyl alcohol-based polarizing films, there are those in which polyvinyl alcohol-based films are dyed with iodine and those in which dichroic dyes are dyed.

The polyvinyl alcohol-based polarizing film can be a polyvinyl alcohol-based film that is uniaxially stretched and then dyed with iodine or a dichroic dye (preferably, it is a film that is further treated with a boron compound for durability); or it can be It is a polyvinyl alcohol-based film dyed with iodine or a dichroic dye and then uniaxially stretched (preferably a film further treated with a boron compound for durability). The absorption axis of polarized photons is usually parallel to the direction of maximum stretching.

For example, 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% are used, as described in Japanese Patent Application Laid-Open No. 2003-248123, Japanese Patent Application Laid-Open No. 2003-342322, etc. Ethylene modified polyvinyl alcohol. Among them, it is preferable to use an ethylene-modified polyvinyl alcohol film with a hot water cut-off temperature of 66 to 73°C.

The thickness of the polarizer is preferably in the range of 5 to 30 μm. In order to reduce the thickness of the polarizing plate, it is more preferably in the range of 5 to 20 μm.

When the optical film of the present invention is used as a λ/4 film, the angle between the in-plane slow axis of the optical film of the present invention and the absorption axis of polarized photons is preferably in the range of 20 to 70°, and more preferably 30 to 60°. , and preferably within the range of 40~50°. When the optical film of the present invention is used as a retardation film for VA, the in-plane slow axis of the optical film of the present invention and the absorption axis of polarized photons can be slightly at right angles.

In addition, the polarizer and the optical film are preferably bonded together through an adhesive or adhesive. The adhesive may be a water-based adhesive containing a polyvinyl alcohol-based resin or a urethane resin as a main component, or a photo-curable adhesive containing a photo-curable resin such as an epoxy resin as a main component. The adhesive may include an acrylic polymer, a polysiloxane polymer, a polyester, a polyurethane, a polyether, or the like as a base polymer. Among them, a water-based adhesive is preferred because it has good affinity with the optical film of the present invention and is not easily deformed due to water absorption. The lamination of polarizers and the optical film of the present invention can usually be performed roll-to-roll.

(Polarizing plate protective film) A polarizing plate protective film is placed on the surface opposite to the optical film of the polarizer. Examples of polarizing plate protective films include commercially available cellulose acyl compound films (for example, Konica Minolta Tuck KC6UA, KC8UX, KC4UX, KC5UX, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR- 5. KC4FR-1, KC8UY-HA, KC8UX-RHA, KC8UE, KC4UE, KC4HR-1, KC4KR-1, KC4UA, KC6UA and above Konica Minolta Opto (stock), etc.

Although the thickness of the polarizing plate protective film is not particularly limited, it is preferably in the range of 10 to 100 μm, more preferably in the range of 10 to 60 μm, and particularly preferably in the range of 20 to 60 μm.

[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 bonded to at least one side of the liquid crystal unit, and is characterized in that the adhesive sheet is adjacent to the liquid crystal unit.

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 unit 30, a first polarizing plate 40 and a second polarizing plate 50 holding the unit, and a backlight 60.

The display mode of the liquid crystal unit 30 may be any display mode such as TN (Twisted Nematic), VA (Vistical Alignment), or IPS (In Plane Switching). The liquid crystal unit used in mobile equipment is preferably in IPS mode, for example. For medium and large-sized liquid crystal units, VA mode is preferred.

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

The second polarizing plate 50 has been disposed on the backlight side surface of the liquid crystal unit 30, and includes the second polarizer 51, a protective film 53 (F3) disposed on the liquid crystal cell side surface of the second polarizer 51, and a protective film 53 (F3) disposed on the liquid crystal cell side surface. Protective film 55 (F4) on the side opposite to the liquid crystal cell of the second polarizer 51.

The absorption axis of the first polarized photon 41 and the absorption axis of the second polarized photon 51 are preferably perpendicular.

The protective film 45 (F2) can be defined as the optical film of the present invention. The easy-adhesion layer of the optical film and the first polarizer 41 are directly laminated. The in-plane slow axis of the protective film 45 (F2) and the absorption axis of the first polarized photon 41 can be approximately perpendicular. The protective films 43 (F1), 53 (F3) and 55 (F4) can be, for example, the aforementioned polarizing plate protective films.

In FIG. 2 , the protective film 45 (F2) is shown as an example of the optical film of the present invention, but the invention is not limited thereto. The protective film 45 (F3) may also be used as the optical film of the present invention. For example, when the protective film 53 (F3) is used as the optical film of the present invention, it is preferable to form a roughened surface on the liquid crystal cell side surface of the protective film 53 (F3), and to provide it between the roughened surface and the liquid crystal cell. Sticky flakes. Furthermore, it is preferable to form an easy-adhesion layer on the surface opposite to the roughened surface.

The optical film of the present invention as the protective film 45 (F2) has a moisture permeability (40°C, 95%RH) in the range of 0.1 to 60g/(m ² ･24h), and has roughening on one side. surface, and the single-sided external haze of the aforementioned roughened surface is more than 0.02% and less than 0.10%. Since the single-sided external haze of the roughened surface side is high, the surface roughness also increases, increasing the contact with the adhesive sheet. area, improve the adhesion, and thereby increase the amount of moisture released from the adhesive sheet. As a result, a liquid crystal display device using the optical film of the present invention can suppress clouding of the panel. [Example]

Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these. Furthermore, in the following examples, unless otherwise specified, operations were performed at room temperature (25°C). In addition, unless otherwise specified, "%" and "parts" mean "mass %" and "mass parts" respectively.

[Preparation of adhesive composition (A)] 100 parts by mass of an acrylic adhesive main agent containing 4.5 mass% of 4-hydroxybutyl acrylate units (4-HBA), 60 mass% of butyl acrylate units, and 35.5 mass% of methyl acrylate units is blended as a cross-linking agent 0.3 parts by mass of toluene diisocyanate compound (manufactured by Nippon Polyurethane Industry, CORONATE L), pentaerythritol-4(3-(3,5-di-t-butyl-4-hydroxyphenyl) as a hindered phenol antioxidant ) propionate) (BASF Japan Co., Ltd., IRGANOX1010) 0.7 parts by mass, ginseng (2,4-di-t-butylphenyl) phosphite (BASF Japan Co., Ltd., IRGAFOS168) as a phosphorus antioxidant parts by mass to obtain adhesive composition (A).

[Preparation of adhesive composition (B)] Place 97 parts by mass of n-butylacrylate (n-BA), 2 parts by mass of N-vinyltetrahydropyrrolone (NVP), and 1, 1 mass part of 4-cyclohexanedimethanol monoacrylate (CHDMMA) and 100 mass parts of ethyl acetate were heated to 70°C while introducing nitrogen gas. Next, 0.05 parts by mass of azobisisobutylbutyronitrile was added, and heating and cooling were repeated so that the temperature of the contents in the beaker could be maintained at 70 to 71°C, and the reaction was carried out for 4 hours. Then, 1 hour after adding azobisisobutylbutyronitrile, 50 parts by mass of ethyl acetate was dropped over about 1 hour. After the reaction, ethyl acetate was further added to obtain a (meth)acryl-based polymer with a weight average molecular weight (Mw) of 1.8 million and a weight average molecular weight/number average molecular weight (Mw/Mn) of 6.0. With respect to 100 parts by mass of the solid content of the (meth)acryl-based polymer, 0.2 parts by mass of an isocyanate cross-linking agent (TD-75: manufactured by Soken Chemical Co., Ltd.) and a silane coupling agent (KBM- 403: manufactured by Shin-Etsu Chemical Industry Co., Ltd.) and mixed 0.2 parts by mass with a solid content to obtain an adhesive composition (B).

[Preparation of adhesive compositions (C), (D) and (E)] In the same procedure as for the preparation of the adhesive sheet (A), the amount of 4-hydroxybutyl acrylate unit (4-HBA) in the adhesive was changed to obtain an adhesive composition with a moisture content shown in Table I below ( C), (D) and (E). However, the moisture content is calculated by the method mentioned above.

[Manufacturing of polarizing plates with adhesive layer] Each of the adhesive compositions prepared above was applied to the peeled PET film so that the thickness after drying became 25 μm, and dried at 90°C for 3 minutes to form an adhesive layer and prepare an adhesive sheet (A) ~ (E). Then, (optical film)/(polarizing photon)/(polarizing plate protective film) are sequentially attached to each adhesive sheet from the side close to the adhesive layer, and aged for 7 days in an environment of 23°C and 50% RH to produce an adhesive sheet. Samples 1 to 52 of polarizing plates with adhesive layer. However, the optical films shown below were used for samples 1 to 52 respectively.

[Sample 1] ＜Optical film 1＞ As the optical film 1, commercially available product "ZEONOR1420R" (manufactured by Zeon Corporation of Japan) was used. It is denoted as "Resin A" in the table below.

[Sample 2] ＜Manufacturing of optical film (A)＞ Pellets of a resin containing a cycloolefin polymer (glass transition temperature: 137°C; "ZEONOR1420R" manufactured by Zeon Corporation of Japan, denoted as "resin B" in the table below) were dried at 100°C for 5 hours. Then, the dried resin pellets were supplied to a single-screw extruder. After the resin is melted in the extruder, it is extruded from the T mold on the casting drum through the polymer tube and polymer filter into flakes and then cooled. Thereby, an optical film (A) with a thickness of 100 μm and a width of 500 mm was obtained.

<Manufacturing of Optical Film 2> Using a tenter-type transverse stretching machine, the two ends of the obtained optical film (A) were held with clamps, and continuously stretched transversely and uniaxially at a stretching temperature of 155°C and a stretching magnification of 2.5 times, and then cut. Remove the left and right ends. In this way, the optical film 2 with a thickness of 40 μm and a width of 1250 mm was obtained.

[Sample 3] ＜Mold manufacturing＞ An aluminum ingot with a purity of 99.99% is cut into a cylindrical aluminum base material with an outer diameter of 200mm, an inner diameter of 155mm, and a length of 1250mm without rolling marks. After hub grinding, the aluminum ingot is ground in a perchloric acid/ethanol mixed solution ( Volume ratio = 1/4) electrolytic grinding and mirror polishing. The obtained aluminum substrate was anodized in a 0.3M oxalic acid aqueous solution under conditions of DC 35V and temperature 16°C for 10 minutes. Then, the aluminum base material 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 under the conditions of DC 35V and temperature 16°C for 30 seconds. The aluminum base material on which the obtained oxide film was formed was immersed in a 5 mass % phosphoric acid aqueous solution at 30° C. for 8 minutes to perform a pore diameter enlarging treatment (pore diameter enlarging treatment step). Then, the aluminum substrate was anodized (oxide film growth step) in a 0.3M oxalic acid aqueous solution under the conditions of DC 35V and temperature 16°C for 30 seconds. This pore size expansion process and the oxide film growth process were repeated a total of 4 times, and finally the pore size expansion process was performed to obtain anodized aluminum oxide with slightly conical pores designed to have an average interval of 50 nm and a depth of 100 nm on the surface. Roll-shaped mold.

＜Production of optical film with roughened surface＞ The obtained roll-shaped mold was rotated, and the optical film 2 was moved along the outer peripheral surface of the mold in the rotation direction with a pressure of 1 MPa and a time of 60 seconds. Then, it is peeled off from the mold, and the optical film 3 is obtained.

[Sample 4~6] ＜Production of optical film with roughened surface＞ The obtained roll-shaped mold was rotated, and the optical film 2 was moved along the outer peripheral surface of the mold in the rotation direction at the pressure and time shown in Table II below. Then, it is peeled off from the mold, and optical films 4-6 are obtained.

[Sample 7~14] <Manufacturing of Optical Film 7> Pellets of a resin containing a cycloolefin polymer (glass transition temperature: 137°C; "ZEONOR1420R" manufactured by Zeon Corporation, Japan) (described as "resin B" in the table below) were dried at 100°C for 5 hours. Then, the dried resin pellets were supplied to a single-screw extruder. After the resin is melted in the extruder, it is extruded from the T-die into a thin sheet on the casting drum through the polymer tube and polymer filter, and is cooled to produce a raw material film with a film thickness of 1000 μm. Using a tenter-type transverse stretching machine, both ends of the obtained raw film were held with clamps, and transversely uniaxially stretched continuously at a stretching temperature of 155°C and a stretching ratio of 2.5 times, and then the left and right ends were stretched The part is cut and removed so that the film width becomes 1250mm. One side of the obtained optical film was the same as the optical film 3, and was subjected to surface treatment with a mold using a pressure of 1 MPa and a stamping time of 60 seconds to form a roughened surface, thereby obtaining the optical film 7.

＜Manufacturing of optical films 8~12＞ In the same manner as Optical Film 7, the thickness of the raw film was changed as shown in Table III below, and a tenter-type transverse stretching machine was used. Both ends of the resulting film were held with clamps, and the film was stretched at a stretching temperature of 155°C. Transverse uniaxial stretching was performed continuously at a magnification of 2.5 times, and the left and right end portions were cut and removed so that the film width became 1250 mm. One side of the obtained optical film was the same as optical film 3, and was subjected to surface treatment with a mold using a pressure of 1 MPa and a stamping time of 60 seconds to form a roughened surface, thereby obtaining optical films 8 to 12.

<Manufacturing of optical films 13 and 14> The raw material was changed to Arton G7810 (ARTON-G7810 (manufactured by JSR Corporation)) (referred to as "Resin C" in the table below). It was the same as the optical film 7. The thickness of the raw film was changed as shown in Table IV below, and it was the same as the optical film 3. Similarly, the surface treatment by the mold is performed with a pressure of 1 MPa and a stamping time of 60 seconds to form a roughened surface, and optical films 13 and 14 are produced. Arton G7810 is a cyclic olefin resin (a copolymer of a monomer represented by general formula (A-2) and a vinyl compound), weight average molecular weight Mw=140000).

[Sample 15~19] ＜Manufacturing of optical film 15＞ Pellets of a resin containing a cycloolefin polymer (glass transition temperature: 137°C; "ZEONOR1420R" manufactured by Zeon Corporation, Japan) (described as "resin B" in the table below) were dried at 100°C for 5 hours. Then, the dried resin pellets were supplied to a single-screw extruder. After the resin is melted in the extruder, it is extruded from the T-die into a sheet on the casting drum through the polymer tube and polymer filter, and then cooled to produce a raw material film with a thickness of 50 μm. Then, using a tenter-type transverse stretching machine, both ends of the obtained film were held with clamps, and transversely uniaxially stretched continuously at a stretching temperature of 155°C and a stretching ratio of 2.5 times, and then the left and right sides were stretched. The end portion is cut and removed so that the film width becomes 1250mm. One side of the obtained optical film was the same as the optical film 3, and was subjected to surface treatment with a mold using a pressure of 1 MPa and a stamping time of 60 seconds to form a roughened surface, thereby obtaining the optical film 15.

＜Manufacturing of optical films 16~19＞ In the same manner as Optical Film 15, the thickness of the raw film was changed as shown in Table V below. A tenter-type transverse stretching machine was used. Both ends of the resulting film were held with clamps and stretched at a stretching temperature of 155°C. The magnification was changed as shown in Table V below, transverse uniaxial stretching was performed continuously, and the left and right end portions were cut and removed so that the film width became 1250 mm. One side of the obtained optical film was the same as the optical film 3, and was subjected to surface treatment with a mold using a pressure of 1 MPa and a stamping time of 60 seconds to form a roughened surface, thereby obtaining optical films 16 to 19.

[Sample 20] <Manufacturing of optical film 20> For the optical film 20, commercially available e-ZB12 (manufactured by Zeon Corporation of Japan) was used. Mark it as "Resin D" in the following table.

[Sample 21] <Manufacturing of optical film 21> (Production of material Y) Aqueous dispersion of polyurethane (trade name "ADEKA BONTIGHTER", manufactured by ADEKA Co., Ltd., as polymer Yp, containing carbonate-based polyurethane having a polar group, glass transition temperature -16°C) 100 parts by mass (amount based on the mass of polyurethane in the aqueous dispersion) was measured, and 10 parts by mass of an epoxy compound (trade name "DENACOL EX-521", manufactured by Nagase ChemteX Co., Ltd.) was blended therein. With 6 parts by mass of adipic acid dihydrazide and water, material Y was obtained as a liquid aqueous resin composition with a solid content of 22%.

(Lamination of easy-to-adhere layers) Using a corona treatment device (manufactured by Kasuga Electric Co., Ltd.), under the conditions of an output of 500 W, an electrode length of 1.35 m, and a conveying speed of 15 m/min, the optical film (A) (resin containing a cyclic olefin polymer (Japanese Zeon)) produced above was The surface of one side of the company's "ZEONOR1420R") was subjected to discharge treatment. On the surface of the optical film (A) on the side of the discharge treatment, material Y was coated using a roller coater so that the dry film thickness became 2.0 μm. Then, use a tenter-type transverse stretching machine to hold both ends of the optical film (A) with clips, and continuously stretch the optical film (A) horizontally and uniaxially at a stretching temperature of 155°C and a stretching ratio of 2.5 times, and then cut the left and right sides. parts at both ends are removed. Thereby, the step of drying and hardening the coated material Y and the step of stretching the optical film (A) are carried out simultaneously, and a coating layer (made of polyurethane resin) is laminated on the surface of the optical film 2 The easy-adhesion layer formed), and an optical film 21 with a total film thickness of 40 μm (layer A: coating layer = 20:1) and a width of 1250 mm was obtained. In the resin column of the table below, it is denoted as "resin E".

[Sample 22~25] ＜Manufacturing of optical films 22~25＞ The roll-shaped mold used for manufacturing the optical film 3 is rotated, and the optical film 21 is moved along the outer peripheral surface of the mold in the rotation direction at the pressure and time shown in Table VI below. Then, it is peeled off from the mold, and optical films 22-25 are obtained.

[Sample 26~33] <Manufacturing of optical film 26> Pellets of a resin containing a cycloolefin polymer (glass transition temperature: 137°C; "ZEONOR1420R" manufactured by Zeon Corporation of Japan) were dried at 100°C for 5 hours. Then, the dried resin pellets were supplied to a single-screw extruder. After the resin is melted in the extruder, it is extruded from the T-die into a thin sheet on the casting drum through the polymer tube and polymer filter, and is cooled to produce a raw material film with a film thickness of 1000 μm. Using a corona treatment device (manufactured by Kasuga Electric Co., Ltd.), discharge treatment was performed on the surface of one side of the raw film under the conditions of an output of 500 W, an electrode length of 1.35 m, and a conveying speed of 15 m/min. Material Y was applied to the surface of the raw material film on the side where the discharge treatment was performed using a roll coater so that the dry film thickness became 2.0 μm. Then, using a tenter-type transverse stretching machine, both ends of the obtained raw film were held with clamps, and continuously transversely uniaxially stretched at a stretching temperature of 155°C and a stretching magnification of 2.5 times, and then the left and right ends were stretched The part is cut and removed so that the film width becomes 1250mm. Thereby, the step of drying and hardening the coated material Y and the step of stretching the raw material film were carried out simultaneously, and the coating layer was laminated on the surface of the film to obtain a total film thickness of 400 μm (layer A: coating Layer=20:1) optical film 26.

＜Manufacturing of optical films 27~31＞ In the same manner as Optical Film 26, the thickness of the raw film was changed as shown in Table VII below, and a tenter-type transverse stretching machine was used. Both ends of the resulting film were held with clips, and the stretching temperature was 155°C and the stretching ratio was 155°C. 2.5 times continuous transverse uniaxial stretching, and then the left and right ends are cut and removed so that the film width becomes 1250mm. The same surface treatment as that of the optical film 3 was performed on one side of the obtained optical film to form a roughened surface, thereby obtaining optical films 27 to 31.

<Manufacturing of optical films 32 and 33> The raw material was changed to Arton G7810 (manufactured by JSR Corporation) (denoted as "Resin C" in the table below). It was the same as the optical film 26. The thickness of the raw material film was changed as shown in Table VIII below, and the material Y was applied and stretched on After roughening the surface of the raw film, the same surface treatment as that of the optical film 3 was performed to form a roughened surface, and the optical films 32 and 33 were produced.

[Sample 34] <Manufacturing of optical film 34> The material Y described in the optical film 21 was coated on the optical film (A) using a roll coater, and a tenter-type transverse stretching machine was used to obtain a total film thickness of 20 μm (layer A: coating layer = 20: 1) General optical film 34. The surface opposite to the coating layer of the obtained optical film 34 was subjected to surface treatment with a mold using a pressure of 1 MPa and a stamping time of 60 seconds in the same manner as the optical film 3 to obtain a roughened surface.

[Sample 35] ＜Manufacturing of optical film 35＞ 100 parts by mass of dipentaerythritol hexaacrylate (KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.), 2-methyl-1[4-(methylthio)phenyl]-2-morpholinylpropan-1-one (Ciba 4 parts by mass of Irgacure 907 (manufactured by Specialty Chemicals Co., Ltd.) was dissolved in toluene using a disperser. The obtained coating liquid is coated on the optical film (A) with a roller coater, and the solvent is removed in an oven before being irradiated with ultraviolet rays to produce an easy-adhesive layer. Next, 80 parts by mass of polymethyl methacrylate (PMMA) resin (Dianal BR-85 manufactured by Mitsubishi Chemical Corporation) was dissolved in methyl ethyl ketone at an arbitrary solid content, and the cross-linked NBR rubber filler ( 20 parts by mass of XER-91 (manufactured by JSR Corporation, particle diameter: 0.07 μm) was dispersed in a disperser to obtain a coating liquid. The obtained coating liquid was coated on the optical film (A) using a roller coater to obtain an optical film 35 with a total film thickness of 20 μm (A layer: coating layer = 20:1).

The surface opposite to the coating layer of the obtained optical film 35 was subjected to surface treatment with a mold using a pressure of 1 MPa and a pressing time of 60 seconds in the same manner as the optical film 3 to obtain a roughened surface.

[Sample 36] ＜Manufacturing of optical film 36＞ (Synthesis of vinyl aromatic resin) In a glass beaker equipped with a stirrer, capacitor, and thermometer, add 127.87g (1.23mol) of styrene, 13.3g (0.136mol) of maleic anhydride, 75g of toluene as the solvent, and 1,1' as the free radical initiator. - 0.7 g (2.7 mmol) of azobis(cyclohexane-1-carbonitrile (Carbonitrile)), heated to 90°C, and allowed to react for 15 hours. A part of this polymerization solution was taken out and the reaction rate was measured to be 85%. Moreover, when the molecular weight was measured, Mw=129,900 and Mw/Mn=2.00. By diluting the obtained polymerization reaction solution with tetrahydrofuran and solidifying it in a large amount of methanol, the vinyl aromatic resin was recovered and purified, and dried in a vacuum dryer at 80°C for 2 days.

(Coating of optical films) The obtained vinyl aromatic resin was dissolved in methyl ethyl ketone to prepare a coating solution with a resin concentration of 35%. Use a coater to coat the resulting solution on the optical film (A), dry at 50°C for 10 minutes, at 80°C for 10 minutes, and at 110°C for 300 minutes to obtain a total film thickness of 20 μm (layer A: coated Cloth layer=20:1) optical film 36.

The surface opposite to the coating layer of the obtained optical film 36 was subjected to surface treatment with a mold using a pressure of 1 MPa and a stamping time of 60 seconds in the same manner as the optical film 3 to obtain a roughened surface.

[Sample 37] ＜Manufacturing of optical film 37＞ Using a tenter-type transverse stretching machine, the two ends of the obtained film (A) were held with clamps, and continuously stretched transversely and uniaxially at a stretching temperature of 155°C and a stretching magnification of 2.5 times, and then the left and right sides were cut. The end part is removed. In this way, an optical film 37 with a thickness of 40 μm and a width of 1250 mm was obtained.

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

[Sample 38] ＜Manufacturing of optical film 38＞ The roll-shaped mold used for manufacturing the optical film 3 was operated for the optical film 37 at a pressure of 1 MPa and a time of 60 seconds. Then, it is peeled off from the mold, and the optical film 38 is obtained.

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

[Sample 39~41] ＜Manufacturing of optical films 39~41＞ The roll-shaped mold used for manufacturing the optical film 3 is rotated, and the optical film 37 is moved in the rotation direction along the outer peripheral surface of the mold at the pressure and time shown in Table IX below. Then, it is peeled off from the mold, and optical films 39-41 are obtained.

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

[Sample 42~46] <Manufacturing of optical film 42> The coating of the material Y described in Sample 21 and the stretching of the raw material film were carried out to obtain an optical film 42 with a total film thickness of 40 μm (layer A: coating layer = 20:1) and a width of 1250 mm.

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

＜Manufacturing of optical films 43~46＞ The roll-shaped mold used for manufacturing the optical film 3 is rotated, and the optical film 42 is moved in the rotation direction along the outer peripheral surface of the mold at the pressure and time shown in Table X below. Then, it is peeled off from the mold, and optical films 43-46 are obtained.

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

[Sample 47~49] The adhesive sheets bonded to the optical film 3 were changed from the adhesive sheet (A) to the adhesive sheets (C), (D), and (E) respectively, and these were used as samples 47 to 49.

[Sample 50~52] The adhesive sheets bonded to the optical film 3 were changed from the adhesive sheet (A) to the adhesive sheets (C), (D), and (F) respectively, and these were used as samples 50 to 52.

For each of the obtained samples, the thickness, moisture permeability, single-sided external haze of the roughened surface, single-sided external haze of the back surface, etc. of the optical film were measured according to the following and are shown in Tables XI and XII below.

＜Measurement of moisture permeability＞ The moisture permeability is measured according to the calcium chloride-cup method described in JIS Z 0208, by leaving the film to be measured under conditions of 40°C and 95% RH for 24 hours.

<Measurement of external haze on one side of the roughened surface> (1) Humidify the optical film in an environment of 23°C and 55%RH for more than 5 hours. Then, the total haze 1 of the obtained optical film was measured with a haze meter (model NDH 4000, manufactured by Nippon Denshoku Co., Ltd.) at a wavelength of 550 nm. (2) Next, drop glycerol (0.05ml) on the cleaned glass slide, and use the above-mentioned humidity-adjusting optical film on it to make the roughened surface become one side of the glass slide so that no air bubbles enter. Glycerin was laminated, and the resulting laminate was placed on the haze meter described above, and the haze A (single-sided external haze on the back side) was measured by setting it so that the optical film faced the direction of the photodetector. (3) Drop glycerol (0.05 ml) on the optical film side of the obtained laminate, place a cover glass on it, set the obtained laminate on the haze meter mentioned above, and measure the internal haze 2. The haze obtained by the measurement is applied to the following formula, and the single-sided external haze B of the roughened surface is measured. Formula: single-sided external haze B of roughened surface = full haze 1 - (internal haze 2 + haze A) Furthermore, the single-surface external haze B of the roughened surface was measured 10 times, and the average value was calculated.

[evaluate] ＜Adhesion＞ The obtained sheet-adhered polarizing plate was cut into a width of 25 mm to prepare a test piece. Peel off the peeled PET film from the test piece, attach the exposed adhesive layer to the glass plate every 1 cm, grasp the moving part, and mark it as white. After bonding, keep it in an autoclave adjusted to 50°C/5atm for 20 minutes and press. After pressing, place it in an environment of 40°C and 95%RH for 1 hour, then stretch the polarizing plate to the glass at an angle of 180°C at a speed of 300mm/min, and measure the adhesion force with the stretched wire. Strength is then evaluated based on the following criteria. The results are shown in Tables XI and XII below. (baseline) ◎◎: The optical film or adhesive layer cannot be peeled off if broken, and the adhesion is good even in an environment of 60℃ and 95%RH. ◎: The optical film or adhesive layer cannot be peeled off if it is broken, and the adhesion is good. 〇: The optical film and the adhesive layer are partially peeled off, but the adhesion is good. △: The optical film and the adhesive layer are partially peeled off, but within the problem-free range. ×: The optical film and the adhesive layer were completely peeled off, indicating poor adhesion.

＜High humidity impact improvement＞ The obtained sheet-adhered polarizing plate was cut into a width of 25 mm to prepare a test piece. Peel off the peeled PET film from the test piece, and attach the exposed adhesive layer to the glass plate. After bonding, let it stand for 5 days in a constant temperature and humidity chamber at 40°C and 95%RH, then take it out and evaluate it based on the following standards. The results are shown in Tables XI and XII below. (baseline) ◎◎: No turbidity on the panel. ◎: The turbidity disappears within 60 seconds. 〇: The turbidity disappears within 10 minutes. △: The turbidity disappears within 1 hour. ×: The turbidity has not disappeared.

As shown in the above results, it is considered that the polarizing plate of the present invention has better adhesion between the adhesive sheet (adhesive layer) and the optical film and can suppress clouding of the panel compared with the polarizing plate of the comparative example.

[Liquid crystal display device 20] <Production of liquid crystal display device 20> As a liquid crystal display device, an LCD TV "AQ-32AD5" manufactured by Sharp was prepared. The polarizing plate on the viewing side is peeled off from the device to use it as a polarizing plate with an adhesive layer, and the sample 20 is bonded so that the adhesive sheet is adjacent to the liquid crystal unit, thereby obtaining a liquid crystal display device 20 .

<Evaluation of Liquid Crystal Display Device 20> When a grid test was performed on the obtained liquid crystal display device 20, peeling occurred in all the grids between the adhesive layer and the optical film, indicating poor adhesion. Furthermore, when left in a constant temperature and humidity chamber at 40°C and 95%RH for 5 days, the turbidity in the liquid crystal display device did not disappear.

[Liquid crystal display device 43] <Evaluation of Liquid Crystal Display Device 43> In the production of the liquid crystal display device 20, except for changing the sample 20 to the sample 43 as the polarizing plate with the adhesive layer, the other liquid crystal display devices 43 obtained by the same procedure were subjected to a grid test, and the adhesive sheet ( There is no peeling between the adhesive layer) and the optical film, indicating good adhesion. In addition, when the liquid crystal display device was left to stand for 5 days in a constant temperature and humidity chamber at 40°C and 95% RH, no turbidity was produced in the liquid crystal display device. [Industrial availability]

The present invention can utilize an optical film that can suppress clouding of the panel without reducing the adhesive force with the adhesive sheet, and can be used in polarizing plates and liquid crystal display devices using the optical film.

30:LCD unit 40: 1st polarizing plate 41: The first polarized photon 43: Protective film (F1) 45: Protective film (F2) 46: Roughened surface 47:Easy bonding layer 48:Adhesive flakes 50: 2nd polarizing plate 51: 2nd polarized photon 53: Protective film (F3) 55: Protective film (F4) 60: Backlight 100: Optical film 101: Roughened surface 102:Easy bonding layer 200:Polarizing plate 300:Polarizing plate protective film 400:Polarized photons 500: Adhesive flakes

[Fig. 1] A schematic diagram showing an example of the structure of the polarizing plate of the present invention. [Fig. 2] A schematic diagram showing an example of the structure of a liquid crystal display device of the present invention.

100: Optical film

101: Roughened surface

102:Easy bonding layer

200:Polarizing plate

300:Polarizing plate protective film

400:Polarized photons

500: Adhesive flakes

Claims (5)

An optical film containing a cycloolefin resin, characterized in that the cycloolefin resin is a resin containing a vinyl compound as a copolymer component, and the moisture permeability (40°C, 95%RH) of the optical film is 0.1~ Within the range of 60g/(m ² .24h), and has a roughened surface on one side, and the external haze on one side of the roughened surface is more than 0.02% and less than 0.10%, the aforementioned vinyl compound is cyclobutene, At least one of cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene, the single-sided external haze on the roughened surface, and the single-sided external haze on the back surface opposite to the roughened surface. The ratio is more than 2:1 and less than 10.0:1.0. The optical film according to claim 1, wherein the back surface opposite to the roughened surface has an easy-adhesion layer containing at least one of an acrylic resin, a vinyl resin, a polyurethane resin, and a polyester resin. A polarizing plate, which is a polarizing plate composed of at least a polarizing plate protective film, a polarizing photon, an optical film and an adhesive sheet laminated in this order, characterized in that the aforementioned optical film is the optical film of claim 1 or claim 2. Such as the polarizing plate of claim 3, wherein at 40°C, The moisture content of the aforementioned adhesive sheet under a 95% RH environment is 10.0% or less. A liquid crystal display device in which at least one side of a liquid crystal unit is bonded to the polarizing plate of claim 3 or claim 4, characterized in that the adhesive sheet is adjacent to the liquid crystal unit.

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