KR20190035848A - Laminated film - Google Patents

Abstract

The present invention provides a laminated film which can maintain a high degree of polarization even under a humid environment.
Wherein the laminated film comprises a polarizing layer in which a dichroic dye is oriented in a polyvinyl alcohol type resin and a resin layer in which a resin film having a slow axis in a direction of crossing the absorption axis of the polarizing layer is formed as a material And an adhesive layer for bonding the polarizer layer and the resin layer, wherein the resin layer includes a plasticizer, and the adhesive layer is a laminated film having a water contact angle on the surface of the adhesive layer of more than 60 degrees.

Description

Laminated film

The present invention relates to a laminated film.

Conventionally, a polarizing plate has been widely used as a polarizing light supplying element in a display device such as a liquid crystal display device and also as a polarizing light detecting element. It is known that a polarizing plate has a structure in which a protective film is bonded to one side or both sides of a polarizing film (polarizing layer) using an adhesive or the like.

As the polarizing film, it is known that a dichromatic dye such as iodine is oriented on a film made of a polyvinyl alcohol-based resin. Iodine in the polarizing film exists as an iodine complex, and depending on the orientation of the polyvinyl alcohol-based resin, the iodine complex itself is also oriented. It is known that this iodine complex absorbs light in the visible region and thus the polarizing film exhibits polarization characteristics (polarization degree).

When a polarizing plate is applied to a display device, various optical layers (resin layers), such as a retardation film having optical characteristics and an optical compensation film, are bonded to a polarizing film provided with a protective film (for example, Patent Document 1). The optical layer may contain an additive such as a plasticizer for the purpose of improving the performance of the film.

Patent Document 1: JP-A-2011-186481

However, when the polarizing plate described in Patent Document 1 is left under a moist heat environment (for example, at an ambient temperature of 60 캜 and a humidity of 95%), the degree of polarization may decrease.

The present invention has been made in view of such circumstances, and an object thereof is to provide a laminated film which can maintain a high degree of polarization even under a humid environment.

As a result of intensive investigations to solve the above-mentioned problems, the inventors of the present invention have found that a plasticizer contained in an optical layer in a wet heat environment shifts to a polarizing film and reacts with an iodine complex contributing to polarization to lose an iodine complex , It was estimated that the resulting polarization degree of the polarizing plate would decrease. On the other hand, in the case where the water contact angle of the surface of the adhesive layer in the adhesive layer interposed between the polarizing film and the optical layer is larger than 60 DEG, it is expected that the transfer of the plasticizer to the polarizing film can be suppressed. I have come to completion.

One aspect of the present invention is a polarizing plate comprising a polarizing layer in which a dichroic dye is oriented in a polyvinyl alcohol based resin and a resin layer in which a resin film having a slow axis in a direction oblique to the absorption axis of the polarizing layer is formed, And an adhesive layer for bonding the polarizer layer and the resin layer, wherein the resin layer includes a plasticizer, and the adhesive layer provides a laminated film having a water contact angle of greater than 60 DEG on the surface of the adhesive layer.

In an embodiment of the present invention, both the polarizer layer and the resin layer may be elongated.

According to one aspect of the present invention, there is provided a laminated film capable of maintaining a high degree of polarization even under a humid environment.

1 is a schematic cross-sectional view showing an example of the layer structure of the laminated film of the present embodiment.
2 is a schematic cross-sectional view showing a modified example of the layer structure of the laminated film of this embodiment.

<Laminated film>

1 is a schematic cross-sectional view showing an example of the layer structure of the laminated film of the present embodiment. 1, the laminated film 1 of the present embodiment includes a polarizer layer 11, a resin layer 21, an adhesive layer 31 for adhering the polarizer layer 11 and the resin layer 21 ). In another embodiment, a protective film may be further laminated on the opposite side of the resin layer 21 in the polarizer layer 11.

The laminated film of the present embodiment may be of a long type, or may be a laminated film obtained by cutting a long laminated film to a predetermined length. The elongated laminated film includes an elongated polarizer layer and a long elongated resin layer. The elongated polarizer layer and elongated resin layer will be described later.

[Polarizer layer]

The polarizer layer refers to an optical film that absorbs linearly polarized light having a vibration plane parallel to the optical axis and transmits linearly polarized light having a vibration plane perpendicular to the optical axis. Specifically, the polarizer layer 11 of the present embodiment is a film in which a dichromatic dye is oriented in a polyvinyl alcohol-based resin (hereinafter sometimes referred to as &quot; PVA-based resin &quot;).

The thickness of the polarizer layer 11 is preferably 30 占 퐉 or less, more preferably 25 占 퐉 or less, further preferably 15 占 퐉 or less, particularly preferably 10 占 퐉 or less, and particularly preferably 7 占 퐉 or less.

When the polarizer layer 11 is a film in which the dichroic dye is oriented in the PVA resin, the polarizer layer 11 may be obtained by stretching the film end containing the PVA resin. When the thickness of the polarizer layer 11 is not more than 7 占 퐉, the coating film containing the PVA-based resin formed on the base material may be stretched together with the base material, and then the base material may be peeled off to obtain the polarizer layer 11.

Examples of the substrate that may be used in the present embodiment include a polypropylene film, a polyethylene terephthalate film, a polycarbonate film, a triacetylcellulose film, a norbornene film, a polyester film, and a polystyrene film.

Examples of the PVA-based resin used in the present embodiment include saponified polyvinyl acetate-based resins. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The degree of saponification of the PVA resin is preferably 80 mol% or more, more preferably 90 mol% or more and 99.5 mol% or less, still more preferably 94 mol% or more and 99 mol% or less. When the degree of saponification is 80 mol% or more, the heat and humidity resistance of the obtained laminated film (1) is improved. When the degree of saponification is 99.5 mol% or less, a laminated film (1) having sufficient polarization performance is obtained.

The PVA resin may be a partially modified polyvinyl alcohol. Olefin modification with, for example, ethylene and propylene; Unsaturated carboxylic acid modification with acrylic acid, methacrylic acid and crotonic acid; An alkyl ester of an unsaturated carboxylic acid, an acrylamide or the like may be used.

The modifying ratio of the PVA resin is preferably less than 30 mol%, more preferably less than 10%. When a PVA resin having a modifying ratio of less than 30 mol% is used, a dichroic dye can be sufficiently adsorbed, and a polarizer having sufficient polarization performance can be obtained.

The average degree of polymerization of the PVA resin is preferably 100 or more and 10,000 or less, more preferably 1,500 or more and 8,000 or less, still more preferably 2,000 or more and 5,000 or less. When the average degree of polymerization is 100 or more, a polarizer having sufficient polarization performance can be obtained. When the average degree of polymerization is 10,000 or less, the solubility in a solvent becomes favorable, and a film containing a PVA resin is easily formed.

PVA resin can be easily obtained from commercial products. Preferable examples of commercially available products include "PVA124" and "PVA117" (both having a degree of saponification of 98 to 99 mol%) manufactured by Kabushiki Kaisha Kuraray Co., "PVA624" (saponification degree: 95 to 96 mol%), "PVA617" (saponification degree: 94.5 to 95.5 mol%); N-300 "and" NH-18 "(both having a saponification degree of 98 to 99 mol%) and" AH-22 "(saponification degree: 97.5 to 98.5 mol%) manufactured by Nippon Seisakusho Kagaku Kogyo K.K., AH-26 "(saponification degree: 97 to 98.8 mol%); JC-33 "(saponification degree: 99 mol% or more)," JF-17 "," JF-17L "and" JF-20 "(both having a saponification degree of 98 to 99%) of" Nippon Sakubi Poval " JM-33 "(saponification degree: 93.5 to 95.5 mol%) and" JP-45 "(saponification degree: 86.5 to 89.5 mol%)," JM- ) And the like.

Examples of the dichroic dye used in the present embodiment include iodine and dichromatic organic dyes. Examples of the dichromatic organic dyes include red BR, red LR, red R, pink LB, rubin BL, Borde GS, sky blue LG, lemon yellow, blue BR, blue 2R, navy RY, green LG, violet LB, violet B, H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo-red, Brilliant Violet BK, Supra Blue G, Supra Blue GL, Supra Orange GL, Direct first orange S, and first black.

The dichroic dye may be used alone, or two or more dichroic dyes may be used in combination.

[Resin Layer]

The resin layer 21 of this embodiment forms a resin film having a slow axis in the direction of crossing the absorption axis of the polarizer layer 11. Such a resin film can be produced through stretching treatment, and the resin film has a tensile stress remaining in a direction of crossing the absorption axis of the polarizer layer 11. The residual stress remaining in the resin film may be one cause of the decrease in the polarization degree of the polarizing plate.

The resin layer 21 has a slow axis in the direction of crossing the absorption axis of the polarizer layer 11 and the angle of the slow axis is 45 ± 10 ° or 135 ± 10 ° with respect to the absorption axis of the polarizer layer 11 . Since the angle of the slow axis is in the above range, the difference between the phase of the light in the fast axis direction and the phase of the light in the slow axis direction becomes? / 2. When the laminated film 1 of the present embodiment is applied to a display device because the phase difference between the fast axis and the slow axis is π / 2, the light having passed through the laminated film 1 can be converted into circularly polarized light. Therefore, even in the case of viewing over a polarizing glass, a structure having excellent visibility can be obtained.

The resin layer 21 of the present embodiment is preferably a retardation layer having a retardation property and a wavelength dispersion characteristic satisfying the following formulas (1) to (4). When the laminated film 1 of the present embodiment is incorporated into a display device by satisfying the expressions (1) to (4) in the resin layer 21, it is possible to see the screen from various directions (azimuth angle and polar angle) It is possible to effectively suppress the change in color. Thereby, the visibility of the image display apparatus can be improved.

(1) 100 nm? R _e (590)? 180 nm,

(2) 0.5 &lt; R _th (590) / R _e (590)

_{(3) 0.85≤R e (450)} / R e (550) <1.00, and

(4) 1.00 &lt; R _e (630) / R _e (550)

_{Wherein, R e (590), R} e (450), R e (550), R e (630) , respectively, represent the in-plane retardation value at 590 ㎚ measuring wavelength, 450 ㎚, 550 ㎚, 630 ㎚ , And R _th (590) represents the retardation value in the thickness direction at the measurement wavelength of 590 nm. These in-plane retardation values and thickness retardation values are values measured under an environment of a temperature of 23 캜 and a relative humidity of 55%.

The in-plane retardation value (R _e ) and the thickness direction retardation value (R _th ) are represented by n _x the refractive index in the in-plane slow axis direction, n _y the refractive index in the in-plane fast axis direction (direction perpendicular to the in- when the refractive index to a thickness of said n _z, the optical film d, is defined by the following formula (S1), formula (S2).

(S1) R _e = (n _x -n _y ) x d

_{(S2) R th = [{} (n x + n y) / 2} -n z] × d

From the viewpoint of more effectively suppressing the color change in the laminated film 1, R _e (590) in the formula (1) is preferably 105 to 170 nm. R _th (590) / R _e (590) in the formula (2) is preferably 0.6 to 0.75. R _e (450) / R _e (550) in the formula (3) is preferably 0.86 to 0.98. R _e (630) / R _e (550) in the formula (4) is preferably 1.01 to 1.06.

For example, the resin layer 21 can be produced by stretching a film containing a resin to be described later. Examples of the stretching treatment include uniaxial stretching and biaxial stretching.

Examples of the stretching direction include a machine direction (MD) of the unstretched film, a direction (TD) perpendicular to the machine direction, and a direction of crossing the machine direction (MD). Here, the unstretched film refers to a film that has not been stretched. In the uniaxial stretching, the unstretched film is stretched in any one of these directions. On the other hand, biaxial stretching may be simultaneous biaxial stretching in which two stretching directions are simultaneously performed, or sequential biaxial stretching after stretching in a predetermined direction and then stretching in other directions.

The stretching treatment may be performed by stretching in the machine direction (machine direction: MD) using two or more pairs of nip rolls having a larger peripheral speed on the exit side, or by gripping both ends of the unstretched film with a chuck, (TD) orthogonal to the flow direction. At this time, it is possible to control the retardation value and the wavelength dispersion within the ranges of the above formulas (1) to (4) by adjusting the thickness of the film or adjusting the stretch magnification.

Further, by adding a wavelength dispersion regulating agent to the resin, it is possible to control the wavelength dispersion value within the range of the above formulas (3) to (4).

In general, a long polarizing film (polarizer layer) has an absorption axis in the long side direction. It is possible to arrange both the rollers and the rollers so that the elongated resin layer and the elongated polarizer layer can be bonded together and the angle between the absorption axis and the slow axis of the resin layer is in the above range , And the resin layer 21 is preferably produced by being stretched obliquely by biaxial stretching.

Examples of the resin forming the resin film include cellulose acetate resin, cycloolefin resin, polyolefin resin, acrylic resin, polyimide resin, polycarbonate resin and polyester resin.

The cellulose acetate resin is composed of a part of cellulose or a completely acetic acid esterified product. Examples of the cellulose acetate-based resin include triacetylcellulose, diacetylcellulose and the like.

A resin film made of a cellulose acetate resin can easily obtain a commercially available product. Preferred examples of commercially available resin films include "Fuji Tack (registered trademark) TD80" and "Fuji (registered trademark)" sold by Fuji Film Co., , And "KC8UX2M" and "KC8UY" sold by Konica Minolta Opto, Inc., and the like.

The cycloolefin resin forming the resin film is a thermoplastic amorphous resin having a unit of a monomer composed of a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene monomer (also referred to as an amorphous polyolefin resin) . The cycloolefin resin may be a hydrogenated product of a ring-opening polymer of the above-mentioned cycloolefin or a hydrogenated product of a ring-opening copolymer using two or more cycloolefins and may be a hydrogenated product of a cycloolefin and an addition copolymer such as an aromatic compound having a chain olefin and / It may be combined. In addition, a polar group may be introduced.

When a resin film is constituted by using a copolymer of a cycloolefin and an aromatic compound having a chain type olefin and / or a vinyl group, examples of the chain type olefin include ethylene and propylene. Examples of the aromatic compound having a vinyl group include styrene,? -Methylstyrene, and nuclear alkyl-substituted styrene. In such a copolymer, the unit of the monomer composed of cycloolefin may be 50 mol% or less, preferably 15 to 50 mol%.

In particular, in the case of using a ternary copolymer of a cycloolefin, a chain olefin and an aromatic compound having a vinyl group, the unit of the monomer composed of the cycloolefin can be made relatively small as described above. In such a terpolymer, the unit of the monomer composed of the chain olefin is desirably 5 to 80 mol%. The unit of the monomer composed of an aromatic compound having a vinyl group is preferably from 5 to 80 mol%.

As a preferable example of a commercially available product, a cycloolefin resin can be easily obtained as a commercially available product, such as "TOPAS (registered trademark)" sold by TOPAS ADVANCED POLYMERS GmbH, , "ATON (registered trademark)" sold by JSR Corporation, "ZEONOR (registered trademark)" and "ZEONEX (registered trademark)" sold by Nippon Zeon Co., And "APEL (registered trademark)" sold by Mitsui Kagaku Kogyo Co., Ltd. and the like.

When the resin layer 21 of the present embodiment is a phase difference layer, the thickness of the phase difference layer is preferably 10 mu m or more and 50 mu m or less.

The resin layer 21 of the present embodiment includes a plasticizer in addition to the resin for forming the resin film, for the purpose of imparting flexibility to the resin film to facilitate drawing. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol, glycerin, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol and trimethylolpropane.

The plasticizer may be used alone, or two or more plasticizers may be used in combination. In particular, ethylene glycol or glycerin is suitably used.

[Adhesive layer]

In the adhesive layer 31 of the present embodiment, the water contact angle on the surface of the adhesive layer 31 is larger than 60 degrees. If the water contact angle is larger than 60 DEG, the affinity between the adhesive layer 31 and the plasticizer is lowered.

Therefore, it is considered that the plasticizer hardly penetrates the adhesive layer 31. Thus, if the plasticizer migrates from the resin layer 21 to the polarizer layer 11 (in the direction of the arrow in Fig. 1) in a humid environment (for example, at an ambient temperature of 60 캜 and a humidity of 95% It is presumed that the invasion of the plasticizer can be suppressed. The upper limit value is not particularly limited, but it may be 100 degrees.

As a method of measuring the water contact angle, conventionally known measurement methods can be used. Conventionally known measuring methods include a? / 2 method, a tangential method, a curve fitting method, a droplet method, an extension contraction method, a slip method, a Wilhelmy method and a permeation rate method. Among them, a droplet method is used in the present embodiment.

The thickness of the adhesive layer 31 is preferably 0.01 m or more and 5 m or less, more preferably 0.01 m or more and 2 m or less, still more preferably 0.01 m or more and 1 m or less. When the thickness of the adhesive layer 31 is 0.01 m or more, sufficient adhesiveness can be obtained. If the thickness of the adhesive layer 31 is 5 占 퐉 or less, the laminated film 1 is unlikely to become defective in appearance.

The material for forming the adhesive layer 31 is not particularly limited as long as the water contact angle on the surface of the adhesive layer 31 is larger than 60 DEG, and a known cured product of an active energy ray curable adhesive composition can be used. Here, the "active energy ray-curable adhesive composition" refers to an adhesive composition which is cured by irradiation with active energy rays (for example, ultraviolet rays, visible rays, electron rays, X-rays, etc.).

The adhesive layer 31 preferably has a moisture permeability of 300 g / m &lt; 2 &gt; 24 hr or less of an evaluation sample obtained by applying the adhesive composition on a triacetyl cellulose film so as to have a thickness of 2 to 3 mu m, Do. The lower limit value of the moisture permeability is not particularly limited, but is, for example, 50 g / m 2 · 24 hr. By using the adhesive layer having such a moisture permeability, the lowering of the degree of polarization can be further reduced.

The evaluation sample can be produced as follows. First, the adhesive composition is coated on the triacetyl cellulose film to a thickness of 2 to 3 占 퐉 to form an adhesive composition layer. As the triacetyl cellulose film for measuring the moisture permeability of the evaluation sample, the thickness was 57.5 占 퐉 and the moisture permeability (value calculated according to the cup method (JIS Z 0208, temperature 40 占 폚, humidity 90% RH) was 553 g / hr. Subsequently, ultraviolet rays are radiated from the side of the adhesive composition layer so that the accumulated light quantity becomes 400 mJ / cm 2 to cure the adhesive composition layer to obtain an evaluation sample. The moisture permeability of the obtained evaluation sample was measured according to the cup method (JIS Z 0208, temperature 40 ° C, humidity 90% RH).

[Active Energy ray-curable adhesive composition]

The active energy ray-curable compound included in the active energy ray-curable adhesive composition (hereinafter sometimes referred to as &quot; the present composition &quot;) is preferably a cationic polymerizable compound or a radical polymerizable compound, And a radical polymerizable compound. When the cationic polymerizable compound and the radically polymerizable compound are contained, the effect of increasing the hardness of the adhesive layer 31 can be expected, and the viscosity and the curing speed of the composition can be adjusted more easily.

(Cationic polymerizable compound)

Examples of the cationic polymerizable compound used in the present embodiment include an oxetane compound or an epoxy compound. From the viewpoint of making the water contact angle on the surface of the adhesive layer 31 larger than 60 DEG, it is preferable to use only the oxetane compound or an oxetane compound and an epoxy compound.

The content of the cationic polymerizable compound is preferably 10 parts by mass or more and 99 parts by mass or less, more preferably 40 parts by mass or more and 99 parts by mass or less, based on 100 parts by mass of the present composition.

Examples of the oxetane compound include 1,4-bis [(3-ethyl-3-oxetanyl) methoxymethyl] benzene, 3-ethyl- 3- (phenoxymethyl) oxetane, di [ -Oxetanyl) methyl] ether, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, and the like.

These oxetane compounds can be easily obtained from commercial products. Commercially available oxetane compounds are available under the trade names "AARON OXETAN (registered trademark) OXT-121" and "AARON oxetane (available from Toagosei Co., (Registered trademark) OXT-211 "," Aronoxetane (registered trademark) OXT-221 "and" Aronoxetane (registered trademark) OXT-212 "

The content of the oxetane compound is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 10 parts by mass or more and 40 parts by mass or less, based on 100 parts by mass of the present composition.

In the present composition, the oxetane compound may be used singly or in combination of two or more.

In addition to the oxetane compound, the composition may contain an epoxy compound, if necessary. The epoxy compound, like the oxetane compound, is one of the cationic polymerizable compounds and can be cured by irradiation of active energy rays. When the composition contains an epoxy compound, the adhesion between the resin layer 21 and the polarizer layer 11 can be improved.

Examples of the epoxy compound include an aromatic epoxy compound, a glycidyl ether of a polyol having an alicyclic ring, an aliphatic epoxy compound, and an alicyclic epoxy compound.

Examples of the aromatic epoxy compounds include bisphenol-type epoxy resins such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F and diglycidyl ether of bisphenol S; Novolak type epoxy resins such as phenol novolak epoxy resin, cresol novolak epoxy resin and hydroxybenzaldehyde phenol novolac epoxy resin; Polyhydric epoxy resins such as glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether of tetrahydroxybenzophenone, and epoxylated polyvinylphenol.

Examples of the glycidyl ether of a polyol having an alicyclic ring include those obtained by subjecting an aromatic polyol to a hydrogenation reaction selectively in an aromatic ring under pressure in the presence of a catalyst to give a glycidyl ether . Examples of the aromatic polyol include bisphenol-type compounds such as bisphenol A, bisphenol F, and bisphenol S; Novolak type resins such as phenol novolak resins, cresol novolak resins, and hydroxybenzaldehyde phenol novolac resins; Tetrahydroxydiphenylmethane, tetrahydroxybenzophenone, polyvinylphenol, and the like can be given.

Glycidyl ether can be obtained by reacting epichlorohydrin with an alicyclic polyol obtained by carrying out a hydrogenation reaction to the aromatic ring of these aromatic polyols.

Of the glycidyl ethers of polyols having alicyclic rings, diglycidyl ethers of hydrogenated bisphenol A are preferred.

Examples of the aliphatic epoxy compound include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof. Specifically, diglycidyl ether of 1,4-butanediol; Diglycidyl ether of 1,6-hexanediol; Triglycidyl ether of glycerin; Triglycidyl ether of trimethylolpropane; Diglycidyl ether of polyethylene glycol; Diglycidyl ether of propylene glycol; Diglycidyl ether of neopentyl glycol; And polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides (ethylene oxide or propylene oxide) to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol or glycerin.

The monofunctional epoxy compound represented by the following formula (I) may also be mentioned as an aliphatic epoxy compound. R ¹ is an alkyl group having 1 to 15 carbon atoms which may be branched. The number of carbon atoms in the alkyl group is preferably 6 or more, more preferably 6 to 10. Of these, an alkyl group branched is preferred. The monofunctional epoxy compound represented by the formula (I) includes 2-ethylhexyl glycidyl ether.

The alicyclic epoxy compound means a compound having at least one structure in the molecule which forms an oxirane ring with the carbon atom of the alicyclic ring. Here, the &quot; structure forming the oxirane ring together with the carbon atom of the alicyclic ring &quot; means a structure represented by the following formula (II). Wherein n is an integer of 2 to 5.

A compound in which one or more hydrogen atoms of (CH ₂ ) _n in the formula (II) are removed from other chemical structures is an alicyclic epoxy compound. Further, one or more hydrogen atoms of (CH ₂ ) _n forming an alicyclic ring may be substituted with a linear alkyl group such as a methyl group or an ethyl group.

As the epoxy compound, an alicyclic epoxy compound is preferable, and epoxycyclohexane (wherein n = 4 in the formula (II)) or epoxycycloheptane And an epoxy compound having [n = 5 in the formula (II)] is more preferable.

The content of the epoxy compound is preferably 1 part by mass or more and 90 parts by mass or less, more preferably 20 parts by mass or more and 80 parts by mass or less, based on 100 parts by mass of the composition.

In this composition, the epoxy compound may be used alone, or two or more epoxy compounds may be used in combination.

(Radical Polymerizable Compound)

In addition to the cationic polymerizable compound such as the oxetane compound or the epoxy compound, a radically polymerizable compound may be contained.

As the radical polymerizing compound, a compound having at least one (meth) acryloyloxy group in the molecule (hereinafter sometimes referred to as a "(meth) acrylic compound"), a compound having at least one (Hereinafter sometimes referred to as a &quot; (meth) acrylamide-based compound &quot;). Further, the term "(meth) acryloyloxy group" means a methacryloyloxy group or an acryloyloxy group, and the (meth) acrylamide group means a methacryloylamide group or an acryloylamide group.

Examples of the (meth) acrylic compound include (meth) acrylate monomers having at least one (meth) acryloyloxy group in the molecule, (meth) acrylate oligomers having at least two (meth) acryloyloxy groups in the molecule . These may be used alone, or two or more of them may be used in combination. (Meth) acrylate monomers and (meth) acrylate oligomers may be used in combination of two or more kinds. Of these, two or more kinds of (meth) acrylate monomers may be used, One or more kinds of oligomers may be used in combination.

As the (meth) acrylamide-based compound, an N-substituted (meth) acrylamide compound can be exemplified. The N-substituted (meth) acrylamide compound is a (meth) acrylamide compound having a substituent at the N-position. A typical example of the substituent is an alkyl group. The substituents at the N-position may be mutually bonded to form a ring, and -CH ₂ - constituting the ring may be substituted with an oxygen atom. A substituent such as an alkyl group or an oxo group (= O) may be bonded to the carbon atom constituting the ring. N-substituted (meth) acrylamides can generally be prepared by the reaction of (meth) acrylic acid or a chloride thereof with a primary or secondary amine.

The content of the radical polymerizing compound is preferably 1 part by mass or more and 70 parts by mass or less, more preferably 10 parts by mass or more and 60 parts by mass or less, based on 100 parts by mass of the composition.

In the present composition, the radical polymerizing compound may be used alone, or two or more kinds thereof may be used in combination.

(Cationic polymerization initiator)

When the composition contains a cationic polymerizable compound such as the oxetane compound or the epoxy compound, it preferably contains a cationic polymerization initiator. The cationic polymerization initiator generates a cationic species or a Lewis acid by irradiation of an active energy ray such as visible light, ultraviolet ray, X-ray or electron beam to initiate the polymerization reaction of the cationic polymerizable compound. Examples of the cationic polymerization initiator include aromatic diazonium salts, onium salts such as aromatic iodonium salts and aromatic sulfonium salts, and iron-arene complexes.

Examples of the aromatic diazonium salt include benzene diazonium hexafluoroantimonate, benzene diazonium hexafluorophosphate and benzene diazonium hexafluoroborate.

Examples of the aromatic iodonium salt include diphenyl iodonium tetrakis (pentafluorophenyl) borate, diphenyl iodonium hexafluorophosphate, diphenyl iodonium hexafluoroantimonate, di (4-nonylphenyl) iodonium hexa Fluorophosphate and the like.

Examples of the aromatic sulfonium salts include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, 4,4'-bis [diphenylsulfone 4,4'-bis [di (? - hydroxyethoxy) phenylsulfonio] diphenylsulfide bishexafluoroantimonate, 4,4'- Bis [di (? - hydroxyethoxy) phenylsulfonio] diphenylsulfide bishexafluorophosphate, 7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthene hexa (Pentafluorophenyl) borate, 4-phenylcarbonyl-4'-diphenylsulfone (pentafluorophenyl) borate, and 2-isopropylthioxanthone tetra (P-tert-butylphenylcarbonyl) -4'-diphenylsulfone hexafluorophosphate, 4- (p- And the like can be mentioned diphenyl sulfide tetrakis (pentafluorophenyl) borate-Ryan Timothy carbonate, 4- (p-tert- butylphenyl-carbonyl) -4'-di (p- toluyl) Pony O.

Examples of the iron-arene complexes include xylene-cyclopentadienyl iron (II) hexafluoroantimonate, cumene-cyclopentadienyl iron (II) hexafluorophosphate, xylene-cyclopentadienyl iron (II) Methanesulfonyl) methanide, and the like.

These cationic polymerization initiators can be easily obtained from commercially available products, and examples thereof include "KAYARAD (registered trademark) PCI-220" and "KAYARAD (registered trademark) ", both of which are sold under the trade names of Nippon Kayaku Co., UVI-6990 " sold by Dow Chemical Company, "UVACURE (registered trademark) 1590 " sold by Daicel-Cytec Industries, CIT-1370 ", "CIT-1370 ", " CIT-1370 " sold by Nippon Soda Co., DPI-101 "," DPI-102 "," DPI-103 ", and" CIp-2064S "sold by Midori Kagaku Co., BBI-103, BBI-105, TPS-101, TPS-101, DPI-105, MPI-103, MPI-105, BBI- 102, TPS-103, TPS-105, MDS-103, MDS-105, DTS-102 and DTS- "PI-2074" which is commercially available from Mitsubishi Electric Corporation.

Of these cationic polymerization initiators, aromatic sulfonium salts are preferable because they can absorb light having a wavelength of 300 nm or more, are excellent in curability, and can obtain a cured product having good mechanical strength and adhesion.

In the present composition, the cationic polymerization initiator may be used singly or in combination of two or more.

(Radical polymerization initiator)

When the composition contains the radically polymerizable compound, it preferably contains a radical polymerization initiator. The radical polymerization initiator may be any known one as long as it can initiate polymerization of a radically polymerizable compound such as a (meth) acrylic compound by irradiation with an active energy ray.

Examples of the radical polymerization initiator include acetophenone, 3-methylacetophenone, benzyldimethylketal, 1- (4-isopropylphenyl) -2-hydroxypropyl- - (methylthio) phenyl-2-morpholinopropane-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one; Benzophenone based initiators such as benzophenone, 4-chlorobenzophenone and 4,4'-diaminobenzophenone; Benzoin ether initiators such as benzoin propyl ether and benzoin ethyl ether; Thioxanthone initiators such as 4-isopropylthioxanthone; In addition, xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone and the like can be mentioned.

As the radical polymerization initiator, commercially available products can be easily obtained. For example, "IGACURE (registered trademark) 184", "IGACURE (registered trademark) 907", "DAROCURE (registered trademark) 1173 "and" Lucirin (registered trademark) TPO ".

In the present composition, the radical polymerization initiator may be used alone, or two or more kinds thereof may be used in combination.

(Other additives)

The composition may contain a photosensitizer, a solvent, a leveling agent, an antioxidant, a photostabilizer, an ultraviolet absorber, and the like within the range not impairing the effects of the present invention.

Examples of the photosensitizer that may be used in the present embodiment include a carbonyl compound, an organic sulfur compound, a persulfide, a redox compound, an azo compound, a diazo compound, a halogen compound, a light reducing pigment and the like.

Examples of the solvent which may be used in the present embodiment include aliphatic hydrocarbons such as n-hexane and cyclohexane; Aromatic hydrocarbons such as toluene and xylene; Alcohols such as methanol, ethanol, propanol, isopropanol and n-butanol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Esters such as methyl acetate, ethyl acetate and butyl acetate; Cellosolve such as methylcellosolve, ethylcellosolve and butylcellosolve; And halogenated hydrocarbons such as methylene chloride and chloroform.

As the leveling agent which may be used in the present embodiment, various compounds such as a silicone type, a fluorine type, a polyether type, an acrylic acid copolymer type, a titanate type and the like can be used.

Examples of the antioxidant that may be used in the present embodiment include a primary antioxidant such as phenol type or amine type, and a secondary type antioxidant of sulfur type.

Examples of the light stabilizer that may be used in the present embodiment include hindered amine light stabilizers (HALS).

Examples of ultraviolet absorbers that may be used in the present embodiment include benzophenone, benzotriazole, and benzoate.

The adjustment of the contact angle of the adhesive layer can be performed, for example, according to the following instructions. That is, the contact angle of the adhesive layer depends on the structure of the compound contained as a main component in the curable resin composition and on the combination of the compounds. For example, when an adhesive layer is formed with a curable resin composition, when the composition contains a polar group such as a hydroxyl group or an amino group, the contact angle tends to be lowered. When the composition contains no polar group, the contact angle tends to be higher.

[Protection film]

2 is a schematic cross-sectional view showing a modified example of the layer structure of the laminated film of this embodiment. 2, the protective film 23 can be further laminated on the side opposite to the side where the resin layer 21 is laminated in the polarizer layer 11 in the laminated film 2. As the material for forming the protective film 23, the same resin as the material forming the resin layer 21 can be used. The material forming the resin layer 21 and the material forming the protective film 23 may be the same or different.

The protective film 23 can be laminated to the polarizer layer 11 through the adhesive layer 33. [

Examples of the adhesive layer 33 include an aqueous adhesive and an active energy ray curable adhesive. Examples of the active energy ray curable adhesive include a cation polymerization type active energy ray curable adhesive and a radical polymerization type active energy ray curable adhesive . In place of the adhesive layer 33, a pressure-sensitive adhesive layer may be provided. As the pressure-sensitive adhesive layer, there can be mentioned a pressure-sensitive adhesive containing an acrylic resin.

A pressure sensitive adhesive layer (not shown) is provided on the side opposite to the side where the resin layer 21 is laminated on the polarizer layer 11 or on the side opposite to the side where the polarizer layer 11 is laminated on the protective film It is also good. By providing the pressure-sensitive adhesive layer, the laminated film 2 can be bonded to the liquid crystal cell of the display device. As the pressure-sensitive adhesive layer, there can be mentioned a pressure-sensitive adhesive containing an acrylic resin. The laminated film of the present invention is preferably disposed on the viewer side of the liquid crystal cell.

[Production method of laminated film]

In the laminated film (1) of this embodiment,

(i) a step of forming a layer of an adhesive composition (hereinafter also referred to as an &quot; adhesive composition layer &quot;) having a water contact angle of more than 60 degrees after curing on one surface of a resin layer 21 having a slow axis,

(ii) the polarizer layer 11 and the adhesive composition layer formed on the resin layer 21 in the above (i) are laminated so that the slow axis of the resin layer 21 is 45 ± 10 ° or 135 ± 10 ° to obtain a laminate in which the polarizer layer 11, the adhesive composition layer, and the resin layer 21 are laminated in this order,

(iii) a step of irradiating an active energy ray (for example, ultraviolet rays, visible light, electron beam, X-ray or the like) to the laminate obtained in the above-mentioned (ii) to cure the adhesive composition layer to obtain an adhesive layer 31 . Hereinafter, specific steps will be described with respect to each step.

In the step shown in (i), first, a resin layer 21 having a slow axis is prepared. When the polarizer layer 11 is continuously produced, the elongated polarizer layer may have an absorption axis in the flow direction. (Laminated film) can be produced, and the angle between the absorption axis and the slow axis of the resin layer 21 can be set in the above range, It is preferable that the stratum 21 is produced by being stretched obliquely.

As a stretching machine used for oblique stretching, for example, a tenter-type stretching machine can be mentioned. The tenter-type stretcher can add a feeding force or a pulling force or a pulling force at right and left different speeds to the transverse direction or the longitudinal direction or both directions thereof. Examples of such a tenter-like stretching machine include a transverse stretching machine and a simultaneous biaxial stretching machine. However, any suitable stretching machine can be used as long as the resin film can be continuously obliquely stretched.

As a method of forming the adhesive composition layer on one side of the resin layer 21, there is a method of directly applying the composition and drying it if necessary. As a separate method, there is a method of applying the present composition to a transparent base film, drying it if necessary, and then transferring the applied layer to the polarizer layer 11. In the latter case, the base film is removed before the step (ii). As the transparent base film, the same resin as described above is used. Further, in the transparent base film, the coated surface of the composition may be subjected to a peeling treatment in advance.

As a coating method of the present composition, a known coating method can be employed, and examples thereof include a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater.

The polarizer layer 11 and the adhesive composition layer formed on the resin layer 21 in the step (i) are bonded to each other to form the polarizer layer 11, the adhesive composition layer, and the resin layer ( 21) are laminated in this order.

In the step shown in (iii), the adhesive layer 31 is cured by irradiating an active energy ray such as visible light, ultraviolet ray, X-ray, or electron beam to the laminate obtained in (ii) To obtain a laminated film (1).

A light source used for irradiation of an active energy ray is not particularly limited, but a light source having a light emission distribution at a wavelength of 400 nm or less is used. Examples of such a light source include a metal halide lamp such as a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a chemical lamp, a black light lamp, and a microwave excited mercury lamp.

Although the irradiation intensity of the active energy ray varies depending on the adhesive composition to be cured, it is preferable to set the irradiation intensity in the wavelength range effective for the activation of the cation polymerization initiator to 10 to 2500 mW / cm2.

The irradiation time of the active energy ray varies depending on the adhesive composition to be cured, but it is preferable to set the accumulated light amount represented by the product of irradiation intensity and irradiation time to a range of 10 to 2500 mJ / cm 2.

In the above production example, the adhesive composition layer is formed on one side of the resin layer 21, but it may be formed on one side of the polarizer layer 11 or on both sides thereof. 2, a protective film 23 may be laminated on the side opposite to the side where the resin layer 21 is bonded to the polarizer layer 11, and a pressure-sensitive adhesive layer (not shown) for bonding to the liquid crystal cell ) May be further provided.

According to the laminated film structured as described above, it is possible to maintain a high degree of polarization even under a humid environment.

&Lt; Laminated film fabric &

In the present embodiment, both the polarizer layer and the resin layer may be elongated. The laminated film fabric of the present embodiment (elongated laminated film) has a band-shaped polarizing film fabric (elongated polarizer layer), a band-shaped resin film fabric (elongated resin layer), a polarizing film fabric, And an adhesive layer for adhering the fabric.

The polarizing film raw fabric is a band-like film made of a PVA-based resin as a forming material, and the dichroism dye is oriented in the longitudinal direction of the film. The PVA-based resin and the dichroic dye are the same as described above.

The resin film fabric is formed by stretching a strip-shaped film made of a thermoplastic resin and a plasticizer in a direction of sagging with respect to the longitudinal direction of the film. As a result, roll-to-roll can be performed in the lamination with the polarizing film raw material, and the manufacturing process can be simplified. The thermoplastic resin and the plasticizer are the same as above.

The resin film fabric is preferably a fabric of a retardation film. The slow axis of the resin film fabric is provided at an arbitrary angle with respect to the absorption axis of the polarizing film original end. It is preferable that an arbitrary angle is, for example, 45 ± 10 ° or 135 ± 10 ° with respect to the absorption axis of the polarizing film fabric. When the angle of the slow axis is in the above-mentioned range, when the material of the laminated film of the present embodiment is applied to a display device, a structure having excellent visibility can be obtained even when viewed from above a polarizing glass.

The adhesive layer includes a cured product of the above-mentioned adhesive composition as a forming material. The water contact angle on the surface of the adhesive layer is greater than 60 degrees. If the water contact angle is larger than 60 DEG, the affinity between the adhesive layer 31 and the plasticizer is lowered. Therefore, it is considered that the plasticizer hardly penetrates the adhesive layer 31. This makes it possible to suppress the penetration of the plasticizer even in the case where the plasticizer migrates from the resin film raw fabric toward the polarizing film raw fabric under a humid environment (for example, at an ambient temperature of 60 캜 and a humidity of 95%) I guess.

According to the laminated film fabric having the above-described constitution, a high degree of polarization can be maintained even under a humid environment.

Example

EXAMPLES The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples. The unstretched film used in this embodiment refers to a film that has not been stretched.

[Measurement of water contact angle on the surface of adhesive layer]

In this embodiment, a liquid-phase method is applied as a measurement method of the water contact angle on the surface of the adhesive layer. Specifically, two cycloolefin based resin films (trade name "ZEONOR (registered trademark)" manufactured by Nippon Zeon Co., Ltd.) having a thickness of 50 μm were prepared. Then, a curable resin composition (an active energy ray curable adhesive composition) prepared by coating each surface of one film with a bar coater so as to have a film thickness of 2 mu m after curing, and one film And more. This laminate was irradiated with ultraviolet rays so that the accumulated light quantity was 250 mJ / cm 2 from one side in accordance with Example 1 to cure the curable resin composition.

Next, one of the films sandwiched between the cured products was peeled off, and then 8 μL of water was dropped on the cured product. Using a fully automatic contact angle measuring device (product name "OCA35" manufactured by Data Physics Co., Ltd.) , And the contact angle of water after standing for 180 seconds was measured.

In the case of the aqueous adhesive composition, one cycloolefin-based resin film as described above was prepared. One side of the film was subjected to corona treatment. Thereafter, the aqueous adhesive composition was coated on its surface to a film thickness of 2 탆 before drying and dried at 80 캜 for 5 minutes to obtain a cured product. The contact angle of the obtained cured product was measured in the same manner as described above.

[Evaluation of heat and humidity resistance of laminated film]

The laminated films of Examples and Comparative Examples were allowed to stand in an environment at a temperature of 65 캜 and a relative humidity of 90% for 250 hours to compare visual acuity correction polarizations before and after being left standing. At that time, the visual acuity correction polarized light intensity after being left was evaluated as?, And the absolute value? Py of the visual acuity correction polarized light intensity before retreating was 0.3 or less. The visual sensitivity correction polarization degree was measured by the following method. The results are shown in Tables 2 to 7.

(Measurement of visual sensitivity correction polarization degree)

MD transmittance and TD transmittance in a wavelength range of 380 nm to 780 nm were measured by a spectrophotometer ("V7100", manufactured by Nihon Bunko K.K.) having an integrating sphere for the laminated films of Examples and Comparative Examples. Next, using the MD transmittance and the TD transmittance, the degree of polarization at each wavelength was calculated based on the formula (T1).

Here, the term "MD transmittance" refers to the transmittance when the direction of the polarized light emitted from the Glan Thompson prism is parallel to the transmission axis of the laminated film sample. The term &quot; TD transmittance &quot; refers to the transmittance when the direction of the polarization from the Glan Thompson prism and the transmission axis of the laminated film sample are orthogonal.

...(T1)

... (T1)

(Measurement of the moisture permeability of the evaluation sample)

Evaluation samples were prepared as follows. First, the adhesive composition was applied on a triacetyl cellulose film to a thickness of 2 to 3 占 퐉 using a bar coater to form an adhesive composition layer. As the triacetyl cellulose film for measuring the moisture permeability of the evaluation sample, the thickness was 57.5 占 퐉 and the moisture permeability (value calculated according to the cup method (JIS Z 0208, temperature 40 占 폚, humidity 90% RH) was 553 g / hr KC6UA manufactured by Konica Minolta K.K. Subsequently, ultraviolet rays were radiated from the side of the adhesive composition layer using a D bulb manufactured by Fusion UV System Co., Ltd. so that the accumulated light quantity became 400 mJ / cm 2 to cure the adhesive composition layer to obtain an evaluation sample. The moisture permeability of the obtained evaluation sample was measured according to the cup method (JIS Z 0208, temperature 40 ° C, humidity 90% RH).

[Production Example (Preparation of adhesive composition)]

Adhesive compositions of Examples and Comparative Examples were prepared in accordance with the blending amounts shown in Tables 2 to 7, respectively. However, the name of the compound used in the preparation may be indicated by an abbreviation.

The cationic polymerization initiator "Ateka Optomer (registered trademark) SP-150" uses a propylene carbonate solution. In Tables 2 to 5, the amount of the effective component is indicated. An aqueous solution is used as the epoxy crosslinking agent " Sumirez Resin (registered trademark) 650 ", which is indicated by the effective ingredient amount in Table 7.

For each component of the adhesive composition, the following compounds were used.

[Active Energy ray-curable adhesive composition]

(Cationic polymerizable compound)

"Celllock (registered trademark) 2021P ": 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, Daicel obtained from Kakuga.

"YX8000 ": diglycidyl ether of bisphenol, available from Mitsubishi Kagaku K.K.

2- [4- [1,1-Bis [4 - ([2,3-epoxypropoxy] phenyl] -2- [4- [ Phenyl] ethyl] phenyl] propane, available from K.K. Printech.

"AARON OXETAN (registered trademark) OXT-101": 3-ethyl-3-hydroxymethyloxetane, obtained from Toagosei Co., Ltd.

"AARON OXETAN (registered trademark) OXT-212": 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane obtained from Toagosei Co., Ltd.

"AARON OXETAN (registered trademark) OXT-221": di [(3-ethyl-3-oxetanyl) methyl] ether obtained from Doagosei K.K.

 Table 1 shows the structure of the oxetane compound.

(Radical Polymerizable Compound)

"DMAA ": Dimethylacrylamide, obtained from KJ Chemical Co., Ltd.

"4HBA ": 4-hydroxybutyl acrylate, available from Nippon Kaya Co., Ltd.

"UV-3700B ": urethane acrylate, available from Nippon Kogaku Kagaku Kogyo K.K.

"CHDMMA ": 1,4-cyclohexanedimethanol monoacrylate, available from Nippon Kaya Co., Ltd.

"A-DCP ": tricyclodecane dimethanol diacrylate, available from Shin Nakamura Kagaku Kogyo K.K.

(Cationic polymerization initiator)

"Ateka Optomer (registered trademark) SP-150 ": 4,4'-bis [diphenylsulfonio] diphenyl sulfide Bis hexafluorophosphate photo cationic polymerization initiator, propylene carbonate solution Obtained from Adeka, Shikoku.

(Radical polymerization initiator)

"DARACURE (R) 1173": 2-hydroxy-2-methyl-1-phenyl-propan-1-one obtained from BASF Japan K.K.

"IGACURE (R) 907": 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one obtained from BASF Japan K.K.

[Adhesive composition in water]

(Polyvinyl alcohol)

"Kurarupofaru (registered trademark) KL-318": carboxyl group-modified polyvinyl alcohol, available from Kabushiki Kaisha Kuraray.

(Epoxy-based crosslinking agent)

"Sumirez resin (registered trademark) 650 ": water-soluble polyamide epoxy resin (aqueous solution having a solid concentration of 30%) and Sumica Chemtech.

[Other components]

"SH710 ": silicone leveling agent, available from Toray Dow Corning Corporation.

[Examples 1 to 17, Comparative Examples 1 to 5]

(a) Fabrication of polarizer layer

A polyvinyl alcohol film having an average degree of polymerization of about 2400 and a degree of saponification of 99.9 mol% or more and a thickness of 30 탆 was uniaxially stretched by a dry method about 5 times and immersed in pure water at 60 캜 for one minute while maintaining a further tension, Was immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 at 72 ° C for 300 seconds. Subsequently, the film was washed with pure water at 26 DEG C for 20 seconds, and then dried at 65 DEG C to prepare a polarizer layer in which iodine was oriented on the uniaxially stretched polyvinyl alcohol film. The thickness of the polarizer was 12 占 퐉.

 (b) Preparation of resin layer

A triacetylcellulose film, which was produced by warp stretching as a resin layer and which contained a plasticizer, was prepared.

A hard coat layer was formed on one side of the triacetylcellulose film. Further, the angle of the slow axis with respect to the longitudinal direction of the film of the resin layer was about 45 DEG on average.

As the triacetylcellulose film produced by oblique stretching, the following materials were used.

Thickness of 44 占 퐉, R _e (590) = 106 nm, R _th (590) = 75 nm, R _th (590) / R _e (590) = 0.71, R _e (450) / R _e (550) = 0.96, R _e (630) / R _e (550) = 1.02)

In addition, R _e (590), R _e (450), R _e (550), and R _e (630) respectively represent the in-plane retardation values at measurement wavelengths of 590 nm, 450 nm, 550 nm, and 630 nm, R _th (590) represents the retardation value in the thickness direction at the measurement wavelength of 590 nm.

(c) Production of laminated film

Next, the adhesive composition obtained in Production Example was applied to the surface of the resin layer (b) on which the hard coat layer was not formed to form an adhesive composition layer. Specifically, an adhesive composition was applied using a bar coater (manufactured by Dai-ichi Rikagaku K.K.) so that the film thickness after curing was about 2 탆. Separately, corona discharge treatment was carried out on one side of an unstretched film (trade name "ZEONOR (registered trademark)" manufactured by Nippon Zeon Co., Ltd.) using a norbornene resin having a thickness of 23 μm as a forming material. The adhesive composition was coated on the corona discharge treated surface in the same manner as the resin layer to form an adhesive composition layer. The unstretched film is a raw material for the protective film in the laminated film.

The adhesive composition layer formed on the resin layer was bonded to one surface of the polarizer layer prepared in the step (a), and the other surface of the polarizer layer and the adhesive composition layer formed on the unstretched film were bonded to each other, Water was produced. A bonding apparatus ("LPA3301" manufactured by Fuji Plastics, Ltd.) was used for bonding. When bonded, the angle formed by the absorption axis of the polarizer layer and the slow axis of the resin layer was 45 °.

Then, ultraviolet rays were irradiated from the unstretched film side of the obtained laminate to an integrated amount of light of 250 mJ / cm &lt; 2 &gt; using an ultraviolet irradiator equipped with a belt conveyor (lamp: "D bulb" To thereby cure the adhesive composition layer. Thus, a laminated film comprising a protective film / polarizer layer / adhesive layer / resin layer / hard coat layer was produced.

The moisture permeability of the evaluation sample obtained from the adhesive composition used in each of the examples and comparative examples was as follows.

247 hr, Comparative Example 2: 307 g / m 2 .24 hr, Comparative Example 3: 428 g / m 2 .24 hr, Comparative Example 2: 4: 529 g / m 2 24 hr

[Comparative Example 6]

(c) A laminated film of Comparative Example 6 was produced in the same manner as in Example 1, except that the following operation was carried out in the production of the laminated film.

The resin layer prepared in (b) above was adhered to one side of the polarizer layer prepared in (a) through the aqueous adhesive composition obtained in Production Example. Thereafter, the film was dried at 80 DEG C for 5 minutes, and then cured at 40 DEG C and 23% RH for 72 hours to produce a laminated film.

[Reference Example]

(a-1) Production of Polarizer Layer

A polarizer layer having a thickness of 30 탆 in which iodine was oriented was formed on a uniaxially stretched polyvinyl alcohol film.

(b-1) Preparation of resin layer

(KC4FR-1, manufactured by Konica Minolta Opto Chemical Co., Ltd.) having a thickness of 43 탆 was subjected to saponification treatment. This film is a stretched film and contains a plasticizer.

(b-2) Preparation of protective film

A triacetylcellulose film having a hard coat layer was saponified. The thickness of this film was 83 탆.

(c-1) Production of laminated film

The resin layer prepared in (b-1) was bonded to one surface of the polarizer layer prepared in the above (a-1) through the nip roll through the aqueous adhesive composition obtained in the above Production Example, and the other The protective film prepared in (b-2) was bonded to the surface of the laminate through the same adhesive composition to prepare a laminate. At this time, the slow axis of the resin layer and the absorption axis of the polarizer layer were made almost parallel. When the protective film prepared in (b-2) was bonded, the side having no hard coat layer was made to be a bonding surface with the polarizer layer. Subsequently, while maintaining the tension of the laminate, the laminate was passed through a drying furnace and dried to obtain a laminated film.

 A pressure-sensitive adhesive layer (thickness: 15 mu m) having a storage modulus of about 0.7 MPa was provided on the opposite side of the resin layer from the surface to be bonded to the polarizer layer. Through the pressure-sensitive adhesive layer, the laminated film was bonded to glass to obtain an evaluation sample. The sample was allowed to stand in an environment at a temperature of 65 占 폚 and a relative humidity of 90% for 250 hours as in the evaluation of the heat and humidity resistance, and the visual sensitivity correction polarization degrees before and after being left standing were compared. As a result, the change amount? Py of the visual sensitivity correction polarization degree was 0.3% or less.

From the results of Tables 2 to 7, it was found that when the water contact angle on the surface of the adhesive layer was larger than 60 DEG, DELTA Py was 0.3 or less, and the high degree of polarization was maintained even under a humid environment.

From the above, it has been confirmed that the present invention is useful.

INDUSTRIAL APPLICABILITY The present invention can be used as a polarized light supplying element or a polarized light detecting element in a display device such as a liquid crystal display device.

1, 2 ... Laminated film
11 ... Polarizer layer
21 ... Resin layer
23 ... Protective film
31, 33 ... Adhesive layer

Claims (2)

A polarizer layer in which a dichroic dye is oriented in a polyvinyl alcohol-based resin,
A resin layer made of a material for forming a resin film having a slow axis in a direction oblique to the absorption axis of the polarizer layer;
And an adhesive layer for bonding the polarizer layer and the resin layer,
Wherein the resin layer comprises a plasticizer,
Wherein the adhesive layer has a water contact angle on the surface of the adhesive layer of greater than 60 DEG. The laminated film according to claim 1, wherein both the polarizer layer and the resin layer are elongated.

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