KR20180050650A - Optical film and manufacturing method thereof - Google Patents

Abstract

An optical film having a cured layer of a curable composition, wherein the curable composition contains a light emitting material having a molar extinction coefficient at a wavelength of 365 nm of not less than 10,000 (ℓ / mol · cm). It is preferable that the optical film is a polarizing film in which a transparent protective film is laminated on at least one surface of a polarizer through an adhesive layer comprising a cured layer of a curable composition. It is preferable that the luminescent material is a coumarin derivative.

Description

Optical film and manufacturing method thereof

The present invention relates to an optical film having a cured layer of a curable composition and a method for producing the same.

Liquid crystal display devices are rapidly expanding in the market for watches, mobile phones, PDAs, notebook PCs, PC monitors, DVD players, and TVs. The liquid crystal display device is made by visualizing the polarization state due to switching of the liquid crystal, and in the principle of display, a polarizer is used. Particularly in applications such as TVs, higher brightness, higher contrast, and a wider viewing angle are required, and polarizing films are increasingly required to have high transmittance, high polarization degree, and high color reproducibility.

The optical film typified by the polarizing film includes, for example, a laminate obtained by bonding a plurality of optical films, or a film obtained by treating the surface of an optical film. In such bonding treatment or surface treatment, By curing this, an adhesive layer, a surface treatment layer and the like are often formed. In these cases, it is very important to control the thickness of the adhesive layer, the surface treatment layer and the like in consideration of the physical properties and appearance of the optical film.

In the following Patent Document 1, in order to evaluate the adhesiveness of a polarizing film, a cutter knife is used to cut only the transparent protective film constituting the polarizing film, and it is evaluated whether or not the transparent protective film can be peeled from the cut position , It is confirmed whether or not the adhesive layer has a sufficient thickness indirectly. However, such an evaluation is a so-called destructive test, which is not easy to carry out and it is not possible to measure the thickness of the intended cured layer more accurately.

Japanese Patent Application Laid-Open No. 2008-80984

The present invention provides an optical film having a cured layer of a curable composition and an optical film capable of easily and accurately measuring the thickness of the cured layer of the curable composition by nondestructive inspection and a method for producing the same.

The above problem can be solved by the following arrangement. That is, the present invention relates to an optical film having a cured layer of a curable composition, wherein the curable composition contains a light emitting material having a molar extinction coefficient at a wavelength of 365 nm of not less than 10,000 (ℓ / mol · cm) Optical film.

In the above optical film, it is preferable that the curable composition contains an active energy ray curable component.

In the optical film, when the total amount of the curable composition is 100 parts by mass, the content of the light emitting material is preferably 0.01 to 10 parts by mass.

In the above optical film, it is preferable that the light emitting material is coumarin and a derivative thereof, and more preferably the coumarin derivative has a diethylamino group.

In the optical film, it is preferable that the optical film is a polarizing film in which a transparent protective film is laminated on at least one surface of a polarizer through an adhesive layer comprising a cured layer of a curable composition, and the thickness of the adhesive layer More preferably 3 mu m or less.

The present invention also provides a process for producing an optical film having a cured layer of a curable composition, comprising the steps of: coating the curable composition on at least one surface of an optical film; and curing the curable composition to form a cured layer The method of manufacturing an optical film according to claim 1, further comprising a step of forming a cured layer, and further comprising the step of measuring a thickness of the cured layer after the step of forming the cured layer, It is preferable to further include a step of measuring the coating thickness of the curable composition.

The method for producing an optical film according to the present invention is characterized in that the optical film is an optical film which is a polarizing film in which a transparent protective film is laminated on at least one surface of a polarizer via an adhesive layer comprising a cured layer of a curable composition A coating step of coating the curable composition on at least one surface of the polarizer and the transparent protective film; an adhesion step of covalently bonding the polarizer and the transparent protective film; and a step of curing the curable composition, And a step of adhering the polarizer and the transparent protective film to each other with the adhesive layer interposed therebetween. The method may further include the step of measuring the thickness of the adhesive layer after the adhering step. After the bonding step, the step of measuring the thickness of the curable composition before curing is added It is more preferable to include it in the lateral direction.

In many cases, the optical film is laminated for the purpose of manifesting various functions. In some cases, interlaminar bond or surface treatment is performed on the outermost layer through a cured layer formed by coating and curing the curable composition. Therefore, the thickness of the formed cured layer is an important factor affecting the adhesiveness and appearance of each layer, so that thickness control is important. As a method of confirming the thickness of the cured layer, there is a method of observing the cross section of the optical film with a scanning electron microscope (SEM) or a transmission electron microscope (TEM) There is a drawback that it takes time to measure the thickness. In addition, even when a measurement is attempted with a dial gauge or the like, there is a problem in accuracy, especially when measuring a thickness of several micrometers. On the other hand, a non-contact optical system may be used to measure the thickness of the cured layer of the optical film in-line during the manufacturing process. However, when the refractive index of the optical film is close to that of the cured layer, none.

On the other hand, in the optical film related to the present invention, a cured layer is formed by a cured layer containing a light emitting material having a molar extinction coefficient at a wavelength of 365 nm of 10000 (ℓ / mol · cm) or more. Therefore, when light having a specific wavelength is irradiated, the amount of light emitted between the optical film and the cured layer is greatly different. Further, for example, when light is vertically irradiated onto the optical film, the amount of light emitted from the cured layer is proportional to the content of the light emitting material contained in the cured layer, that is, the thickness of the cured layer. Therefore, after measuring the light emission amount of the cured layer having an arbitrary thickness in advance, the thickness is accurately measured by, for example, SEM, TEM or the like to prepare a calibration curve showing the relationship between the thickness of the cured layer and the light emission amount, The thickness can be accurately measured by measuring only the amount of light emitted from the cured layer in-line.

In the method of producing an optical film according to the present invention, since the thickness of the cured layer can be measured in in-line as described above, the optical film can be manufactured with the thickness of the cured layer being precisely controlled. In particular, the optical film can be produced in a state in which the thickness of the cured layer to be formed is more accurately managed by coating the curable composition on the optical film and then measuring the coating thickness.

An optical film according to the present invention is an optical film having a cured layer of a curable composition, wherein the curable composition contains a light emitting material having a molar extinction coefficient of 10,000 (l / mol · cm) or more at a wavelength of 365 nm.

≪ Luminescent material &

The curable composition used in the present invention contains a light emitting material having a molar extinction coefficient at a wavelength of 365 nm of not less than 10,000 (ℓ / mol · cm). In the present invention, " luminescent material " means a material that emits light having a wavelength of 420 nm to 480 nm upon irradiation with light of 365 nm, and in the present invention, luminescent material having a molar extinction coefficient within the above range Lt; / RTI > The upper limit of the molar extinction coefficient of the light emitting material to be used is not particularly limited, but may be, for example, about 100,000 (ℓ / mol · cm) or less, and further about 50000 (ℓ / mol · cm) or less.

Examples of the light-emitting material used in the present invention include triazole-based, phthalimide-based, pyrazolone-based, stilbene-based, oxazole-based, naphthalimide-based compounds, rhodamine-based compounds, benzimidazole- Based compounds, coumarin-based compounds, and the like. These may be used alone or in combination of two or more. Of these, coumarin and its derivatives are preferable from the viewpoint of improvement of solubility in the curable composition. Alternatively, stilbene-based compounds are also preferable because they can be added directly to the curable composition as an aqueous solution and are excellent in handleability.

A coumarin derivative is a derivative of an organic compound represented by the formula (C ₉ H ₆ O ₂ ), and may have an organic group at any position on the aromatic ring and / or the heterocyclic ring. The organic group includes, for example, an aliphatic hydrocarbon group, an aryl group, or a heterocyclic group which may have a substituent, and examples of the aliphatic hydrocarbon group include a substituent having 1 to 20 carbon atoms or a group having a hetero atom A cyclic alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 20 carbon atoms or a hetero atom, and an alkenyl group having 2 to 20 carbon atoms. Examples of the aryl group include a substituent having 6 to 20 carbon atoms or a heteroatom , A substituted or unsubstituted naphthyl group having 10 to 20 carbon atoms, and the heterocyclic group includes, for example, a 5-membered ring containing at least one hetero atom, which may have a substituent Or a group of 6-membered rings. They may be connected together to form a loop. A coumarin derivative having a diethylamino group as the organic group is preferable because it has a high molar absorptivity and excellent light emission characteristics even in a small amount.

Examples of coumarin derivatives include 7 {[4-chloro-6- (diethylamino) -s-triazin-2-yl] amino} -7-triazinylamino- Amino-4-methylcoumarin, 7-diethyldiamino-4-methylcoumarin, 3-cyano-7-hydrocoumarin, 7-hydroxycoumarin-3-carboxylic acid, 6,8-difluoro- -Hydroxy-4-methylcoumarin, 7-amino-4-methylcoumarin and the like.

Examples of the stilbene compound include 4,4'-bis (diphenyltriazinyl) stilbene and 4,4'-bis (benzoxazol-2-yl) stilbene. Examples of the naphthalimide-based compound include N-methyl-5-methoxynaphthalimide and the like. Examples of the rhodamine compound include rhodamine B, rhodamine 6G, and the like. Examples of the thiophene compound include 2,5-bis (5'-t-butylbenzoxazolyl-2 ') thiophene, 2,5-bis (6,6'-bis (tert- -Benzooxazol-2-yl) thiophene and the like.

Further, depending on the polymerization initiator used for curing the curable composition, there is a case in which fluorescence is emitted when an active energy ray is irradiated. However, the intensity (amount of emitted light) of fluorescence emitted from the polymerization initiator is quite low, and even when a polymerization initiator is blended in the curable composition, the amount of light emitted when irradiated with light is hardly proportional to the thickness of the cured layer. In addition, the fluorescence intensity emitted from the polymerization initiator varies depending on the chemical state, and the polymerization initiator is decomposed and consumed along with the generation of radicals, so that the amount of light emission decreases over time. For this reason, in the present invention, it is preferable to use a stable light emitting material (not consumed) as a light emitting material, and particularly stable coumarin and its derivatives are preferable. Further, in the present invention, it is preferable that the curable composition contains a polymerization initiator. The curable composition preferably contains the above-described light emitting material in addition to the polymerization initiator.

The content of the light emitting material in the curable composition is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the total amount of the curable composition. When the content of the light emitting material in the curable composition is too small, the light emission amount necessary for detecting the thickness of the cured layer may not be obtained. When the content is too large, the case where the insoluble matter of the light emitting material occurs in the curable composition , Adversely affecting optical properties, adhesion properties, and the like.

Next, the curable composition used in the present invention will be described below.

≪ Curable composition >

In the present invention, a cured layer is formed by using a curable composition. Examples of the cured layer of the optical film include an adhesive layer, a pressure-sensitive adhesive layer, and a surface treatment layer. Hereinafter, as an example of the curable composition, an adhesive composition for forming an adhesive layer and a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer will be described. These are not particularly limited as far as they are optically transparent, and various types such as an aqueous system, a solvent system, a hot melt system, and a radical-curing system are used. In the case of producing a transparent conductive laminate or a polarizing film as an optical film, a transparent curing-type adhesive composition is preferable.

≪ Adhesive composition >

As the adhesive composition, for example, a radical-curable adhesive composition is preferably used. As the radical curable adhesive composition, there can be cited an active energy ray curable adhesive composition containing an active energy ray curable component such as an electron beam curable type, an ultraviolet ray curable type and a visible light curable type. Particularly, an active energy ray curable adhesive composition which can be cured in a short time is preferable, and an ultraviolet curable or visible light curable adhesive composition which can be cured with low energy is preferable.

The ultraviolet curable adhesive composition can be roughly classified into a radical polymerization curable adhesive and a cationic polymerization adhesive. In addition, the radical polymerization curing type adhesive composition can be used as a thermosetting type adhesive.

As the curable component of the radical polymerization curable adhesive composition, an active energy ray curable component is typical, and a compound having a (meth) acryloyl group or a compound having a vinyl group can be given. These curable components may be used singly or in combination of two or more. These curable components may be used singly or in combination of two or more. As the curable component, for example, a compound having a (meth) acryloyl group is preferable.

Specific examples of the compound having a (meth) acryloyl group include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) (Meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, s- (Meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-hexyl Acrylates such as n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl- ) Acrylic acid (having 1 to 20 carbon atoms) alkyl esters.

Examples of the compound having a (meth) acryloyl group include a cycloalkyl (meth) acrylate (e.g., cyclohexyl (meth) acrylate, cyclopentyl (meth) (Meth) acrylate (for example, benzyl (meth) acrylate and the like), polycyclic (meth) acrylates (for example, 2-isobornyl (meth) acrylate and 2-norbornylmethyl (Meth) acrylate), hydroxyl group-containing (meth) acrylate esters (for example, methacrylic acid esters) (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropylmethyl-butyl (meth) methacrylate and the like), an alkoxy group or a phenoxy group- (Meth) acrylate esters (2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) (Meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethylcarbitol Methacrylic acid esters such as glycidyl (meth) acrylate, halogen-containing (meth) acrylic esters (such as 2,2,2-trifluoroethyl (meth) acrylate, (Meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluoro (meth) acrylate, (Meth) acrylate), and alkylaminoalkyl (meth) acrylates (e.g., dimethylaminoethyl (meth) acrylate).

Examples of the compound having a (meth) acryloyl group other than the above include hydroxyethyl acrylamide, N-methylol acrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, And amide group-containing monomers such as amide. And nitrogen-containing monomers such as acryloylmorpholine.

Examples of the curable component of the radical polymerization curable adhesive composition include compounds having a plurality of polymerizable double bonds such as (meth) acryloyl groups and vinyl groups, and the compound is preferably used as a crosslinking component in an adhesive component It may be mixed. Examples of the curable component which becomes a crosslinking component include, for example, tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, (Manufactured by Toa Chemical Industry Co., Ltd.), light acrylate 1,9ND-A (manufactured by Kyowa Chemical Industry Co., Ltd.), light acrylate DGE-4A (available from Kyowa Chemical Industry Co., Ltd.), ethylene glycol diacrylate, EO-modified diglycerin tetraacrylate, Aronix M- SR-531 (manufactured by Sartomer Company), CD-536 (manufactured by Sartomer Company), and the like. If necessary, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, and various (meth) acrylate monomers may be cited.

The radical polymerization curable adhesive composition contains the above-mentioned curable component, but in addition to the above components, a radical polymerization initiator is added according to the curing type. When the above adhesive composition is used in an electron beam hardening type, it is not particularly required to include a radical polymerization initiator in the adhesive composition. In the case of using an ultraviolet hardening type or a thermosetting type, a radical polymerization initiator is used. The amount of the radical polymerization initiator to be used is usually about 0.1 to 10 parts by mass, preferably 0.5 to 3 parts by mass, per 100 parts by mass of the curing component. In addition, a photo-sensitizer may be added to the radical polymerization curable adhesive, if necessary, to increase the curing rate and sensitivity by electron beams typified by carbonyl compounds and the like. The amount of the photosensitizing agent used is usually about 0.001 to 10 parts by mass, preferably 0.01 to 3 parts by mass, per 100 parts by mass of the curable component.

Examples of the curable component of the cationic polymerization curable adhesive composition include compounds having an epoxy group and an oxetanyl group. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used. As a preferable epoxy compound, a compound having at least two epoxy groups and at least one aromatic ring in a molecule, or a compound having at least two epoxy groups in the molecule, at least one of which has two adjacent carbon atoms constituting an alicyclic ring And the like, and the like.

The adhesive composition may suitably contain an additive if necessary. Examples of the additive include a coupling agent such as a silane coupling agent and a titanium coupling agent, an adhesion promoter represented by ethylene oxide, an additive for improving wettability with a transparent film, an acryloxy group compound or a hydrocarbon type (natural or synthetic resin) An antioxidant, a dye, a processing aid, an ion trap agent, an antioxidant, a tackifier, a filler (other than a metal compound filler), a plasticizer, a leveling agent, a foam inhibitor , Stabilizers such as antistatic agents, heat stabilizers, and moisture stabilizers.

The radical polymerization curing type adhesive composition can be used as an electron beam hardening type or an ultraviolet ray hardening type.

In the electron beam hardening type, the irradiation condition of the electron beam may be any appropriate condition as long as it is a condition capable of curing the radical polymerization hardening type adhesive composition. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. When the accelerating voltage is less than 5 kV, the electron beam does not reach the adhesive and thus the curing may be insufficient. When the acceleration voltage exceeds 300 kV, the penetration force through the sample is too strong, There is a concern. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5 kGy, the adhesive becomes insufficient in curing. When the irradiation dose exceeds 100 kGy, the transparent protective film or the polarizer is damaged, resulting in a decrease in mechanical strength or yellowing, .

The irradiation with the electron beam is usually conducted in an inert gas atmosphere, but it may be carried out under a condition where air or oxygen is slightly introduced, if necessary. It is possible to prevent damage to the transparent protective film by forcibly generating oxygen inhibition on the surface of the transparent protective film to which the electron beam first fits by properly introducing oxygen, The electron beam can be irradiated.

On the other hand, when a transparent protective film imparting ultraviolet ray absorbing ability is used in the ultraviolet ray curing type, light having a wavelength shorter than 380 nm is absorbed by light having a wavelength shorter than approximately 380 nm, and thus light having a shorter wavelength than 380 nm does not reach the active energy ray curable adhesive composition. It does not contribute to the polymerization reaction. Further, the light having a wavelength shorter than 380 nm absorbed by the transparent protective film is converted into heat, and the transparent protective film per se generates heat, which causes defects such as curling and wrinkling of the polarizing film. Therefore, when the ultraviolet curing type is adopted in the present invention, it is preferable to use an apparatus which does not emit light having a shorter wavelength than 380 nm as the ultraviolet ray generating apparatus, and more specifically, And the integrated illuminance of the wavelength range of 250 to 370 nm is preferably 100: 0 to 100: 50, more preferably 100: 0 to 100: 40. As the ultraviolet rays satisfying the relationship of the integrated illuminance, gallium-encapsulated metal halide lamps and LED light sources emitting light in the wavelength range of 380 to 440 nm are preferable. Alternatively, the light source may be a metal halide lamp, a fluorescent lamp, a tungsten lamp, a gallium lamp, an excimer laser or a solar light as a light source, such as a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, an incandescent lamp, a xenon lamp, a halogen lamp, Pass filter may be used to shield light of shorter wavelength than 380 nm.

As the curable composition for forming the adhesive layer, an aqueous adhesive composition can also be used. Examples of the aqueous adhesive composition include vinyl polymer, gelatin, vinyl, latex, polyurethane, isocyanate, polyester, epoxy and the like. The adhesive layer composed of such an aqueous adhesive composition can be formed as a coating and drying layer of an aqueous solution. When preparing the aqueous solution, a catalyst such as a crosslinking agent, other additives, or an acid may be added as needed.

As the aqueous adhesive composition, it is preferable to use an adhesive containing a vinyl polymer or the like, and as the vinyl polymer, a polyvinyl alcohol-based resin is preferable. As the polyvinyl alcohol-based resin, an adhesive containing a polyvinyl alcohol-based resin having an acetacetyl group is more preferable in terms of improving durability. As the crosslinking agent that can be blended in the polyvinyl alcohol-based resin, a compound having at least two functional groups having reactivity with the polyvinyl alcohol-based resin can be preferably used. For example, boric acid or borax, carboxylic acid compounds, alkyldiamines; Isocyanates; Epoxies; Monoaldehydes; Dialdehydes; Amino-formaldehyde resins; Further, a divalent metal, a salt of a trivalent metal, and an oxide thereof can be mentioned.

When an adhesive layer is formed using a curable composition, its thickness is preferably 5 占 퐉 or less. More preferably not more than 3 mu m, further preferably not more than 1 mu m. The lower limit of the thickness of the adhesive layer is, for example, 0.01 m or more, and more preferably 0.1 m or more.

≪ Pressure sensitive adhesive composition &

As the pressure-sensitive adhesive composition, various pressure-sensitive adhesives can be used. Examples of the pressure-sensitive adhesive composition include rubber pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, silicone pressure sensitive adhesives, urethane pressure sensitive adhesives, vinyl alkyl ether pressure sensitive adhesives, polyvinyl pyrrolidone pressure sensitive adhesives, polyacrylamide pressure sensitive adhesives, . Depending on the type of the pressure-sensitive adhesive composition, a tacky base polymer is selected. Among the above pressure-sensitive adhesive compositions, an acrylic pressure-sensitive adhesive composition is preferably used because it has excellent optical transparency, exhibits appropriate wettability, cohesiveness and adhesive property, and is excellent in weather resistance and heat resistance.

The optical film of the present invention can be produced by the following production method;

A method for producing an optical film having a cured layer of a curable composition,

A coating step of coating a curable composition on at least one side of the optical film,

And a cured layer forming step of forming a cured layer by curing the curable composition,

And a step of measuring the thickness of the cured layer after the cured layer forming step. Particularly, when the step of measuring the coating thickness of the curable composition after the coating process is further included, the optical film can be manufactured in a state in which the thickness of the formed cured layer is more accurately controlled.

The coating method of the curable composition may be appropriately selected according to the viscosity of the curable composition or the desired thickness, and may be selected from, for example, a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, , A bar coater, a road coater, and the like. The viscosity of the curable composition used in the present invention is preferably 3 to 100 mPa · s, more preferably 5 to 50 mPa · s, and most preferably 10 to 30 mPa · s. When the viscosity of the curable composition is high, surface smoothness after coating is insufficient and appearance defects occur, which is not preferable. The curable composition used in the present invention can be applied by heating or cooling the composition to adjust it to a desired range of viscosity.

The polarizer and the transparent protective film are laminated through the curable composition coated as described above. The polarizer and the transparent protective film can be bonded by a roll laminator or the like.

In the present invention, the kind of the optical film is not particularly limited, but it is preferable to use, as the optical film, a polarizing film in which a transparent protective film is laminated on at least one surface of the polarizer through an adhesive layer comprising a cured layer of the curable composition Film. Hereinafter, a polarizing film will be described as an example of the optical film.

The polarizing film in the present invention is produced by the following production method;

A coating step of coating a curable composition on at least one surface of the polarizer and the transparent protective film,

A bonding step of bonding the polarizer and the transparent protective film,

And a bonding step of bonding the polarizer and the transparent protective film via an adhesive layer obtained by curing the curable composition,

And a step of measuring the thickness of the adhesive layer after the bonding step. Particularly, when the process further comprises a step of measuring the thickness of the curable composition before curing, after the coating process or after the curing process, the optical film can be produced in a state in which the thickness of the cured layer to be formed is more accurately managed have.

When an active energy ray-curable resin composition is used as the curable composition, the polarizer and the transparent protective film are laminated in the adhering step, and then an active energy ray (electron beam, ultraviolet ray, visible ray, The resin composition is cured to form an adhesive layer. The irradiation direction of the active energy ray (electron beam, ultraviolet ray, visible ray, etc.) can be irradiated from any appropriate direction. Preferably, it is irradiated from the side of the transparent protective film. When irradiated from the side of the polarizer, the polarizer may be deteriorated by an active energy ray (electron beam, ultraviolet ray, visible ray, etc.).

As a method for measuring the thickness of the adhesive layer only by measuring the amount of light emitted from the adhesive layer in a polarizing film production process, for example, in a production line of a polarizing film, light having a predetermined wavelength, for example, 365 nm And the amount of light emitted (light amount of 420 nm to 480 nm) emitted at that time is measured using a fluorescence measurement apparatus. Examples of such a fluorescence measurement apparatus include a fluorescence measurement apparatus manufactured by Sen Tec Co., Ltd., which is described in, for example, Japanese Laid-Open Patent Publication No. 2011-145191.

The polarizer and / or the transparent protective film may be subjected to surface modification treatment before applying the active energy ray-curable adhesive composition. Specific examples of the treatment include corona treatment, plasma treatment, and saponification treatment.

Further, in the polarizing film, the polarizer and the transparent protective film are preferably bonded via an adhesive layer formed by the cured layer of the radical polymerization curable adhesive composition. An easy adhesion layer is formed between the polarizer and the transparent protective film can do. The adhesion facilitating layer can be formed by various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone type, a polyamide skeleton, a polyimide skeleton, and a polyvinyl alcohol skeleton, for example . These polymer resins may be used singly or in combination of two or more. Further, other additives may be added to form the adhesion-facilitating layer. Specifically, stabilizers such as a tackifier, ultraviolet absorber, antioxidant, heat stabilizer and the like may be used.

The easy-to-adhere layer is formed by applying a forming material of the easy-to-adhere layer onto a film by a known technique and drying the same. The forming material of the easy-to-adhere layer is usually adjusted as a solution diluted to an appropriate concentration in consideration of the thickness after drying, the original activity of coating, and the like. The thickness of the facilitating layer after drying is preferably 0.01 to 5 占 퐉, more preferably 0.02 to 2 占 퐉, and still more preferably 0.05 to 1 占 퐉. Also, a plurality of layers can be formed as the easy-to-adhere layer. In this case as well, the total thickness of the easy-to-adhere layer is preferably in the above range.

The polarizer is not particularly limited, and various kinds of polarizers can be used. As the polarizer, a dichroic material such as iodine or a dichroic dye may be added to a hydrophilic polymer film such as, for example, a polyvinyl alcohol film, a partially porous polyvinyl alcohol film, or an ethylene / vinyl acetate copolymerization system partially saponified film A polyvinyl alcohol-based dehydrated product, a polyvinyl chloride dehydrochloric acid-treated product, and the like. Of these, a polyvinyl alcohol film and a polarizer made of a dichroic material such as iodine are preferable. The thickness of these polarizers is not particularly limited, but is generally about 80 占 퐉 or less.

A polarizer obtained by dying a polyvinyl alcohol film with iodine and uniaxially stretching can be produced by, for example, dying polyvinyl alcohol in an aqueous solution of iodine and stretching it to 3 to 7 times its original length. And may be immersed in an aqueous solution such as boric acid or potassium iodide, if necessary. If necessary, the polyvinyl alcohol film may be dipped in water and washed with water before dyeing. The polyvinyl alcohol film is washed with water to clean the contaminants and the antiblocking agent on the surface of the polyvinyl alcohol film, and the polyvinyl alcohol film is swollen to prevent unevenness such as uneven dyeing. The stretching may be carried out after dyeing with iodine, followed by stretching while dyeing, or after stretching, followed by dyeing with iodine. It can be stretched in an aqueous solution such as boric acid or potassium iodide or in a water bath.

As the polarizer, a thin polarizer having a thickness of 10 탆 or less can be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 mu m. Such a thin polarizer is preferable because it is excellent in durability because the thickness is uneven, the visibility is excellent, the dimensional change is small, and further, the thickness and thickness of the polarizing film can be reduced.

Typical examples of the thin polarizer include those disclosed in Japanese Laid-Open Patent Publication Nos. 51-069644 and 2000-338329, pamphlets of WO2010 / 100917, PCT / JP2010 / 001460, and Japanese Patent Application No. 2010-269002 And a thin polarizer described in Specification and Japanese Patent Application No. 2010-263692. These thin polarizers can be obtained by a process comprising a step of stretching a layer of a polyvinyl alcohol-based resin (hereinafter also referred to as a PVA-based resin) and a lead resin base material in the form of a laminate, and a step of dyeing. With this method, even if the PVA resin layer is thin, it can be stretched without any problem such as breakage due to stretching because it is supported on the resin base material for drawing.

The thin polarizers described in WO2010 / 100917 pamphlet, PCT / JP2010 / 01109, and JP-A-2002/0159 are preferable because they can be stretched at a high magnification and can improve the polarizing performance even in a process including a step of stretching in the state of a laminate and a step of dyeing. In the aqueous solution of boric acid as described in the specification of Japanese Patent Application No. 2010-016460 or the specification of Japanese Patent Application No. 2010-269002 or the specification of Japanese Patent Application No. 2010-263692, It is preferably obtained by a process comprising a step of auxiliary drawing publicly before drawing in an aqueous boric acid solution described in Specification No. 269002 or Japanese Patent Application No. 2010-263692.

The thin, high-performance polarizer described in the specification of PCT / JP2010 / 001460 is a thin, highly functional polarizer made of a PVA-based resin in which a dichroic substance is aligned and formed integrally on a resin substrate, And a polarization degree of 99.95% or more.

The thin, highly functional polarizer is produced by applying a PVA resin to a resin substrate having a thickness of at least 20 탆 and drying the PVA resin layer to thereby produce a PVA resin layer, and immersing the resulting PVA resin layer in a dyeing solution for a dichroic substance, A PVA resin layer in which a dichroic substance is adsorbed to a PVA resin layer and a dichroic substance is adsorbed is stretched in an aqueous solution of boric acid together with a resin base so that the total draw ratio is 5 times or more the original length .

Also disclosed is a method for producing a laminated film comprising a thin, highly functional polarizer in which a dichroic substance is aligned, comprising the steps of: applying a resin substrate having a thickness of at least 20 탆 and an aqueous solution containing a PVA- And a PVA resin layer formed on one side of the resin base material is immersed in a dyeing solution containing a dichroic substance to form a laminate film, A step of adsorbing a dichroic substance to a PVA-based resin layer contained in the laminated film, and a step of laminating the laminated film including the PVA-based resin layer on which the dichroic substance is adsorbed, A step of stretching the PVA resin layer so as to be at least five times the original length, and a step of stretching the PVA resin layer adsorbed with the dichroic substance integrally with the resin substrate, Film polarizer having a thickness of 7 mu m or less, a single-layer transmittance of 42.0% or more, and a polarization degree of 99.95% or more made of a PVA-based resin layer in which a dichroic substance is oriented By including the step, the thin, highly functional polarizer can be produced.

The thin polarizer disclosed in the specification of Japanese Patent Application No. 2010-269002 or the specification of Japanese Patent Application No. 2010-263692 is a polarizer of a continuous web made of a PVA resin in which a dichroic substance is oriented, Is stretched by a two-step stretching process comprising air-assisted stretching and stretching in water of boric acid, so that the thickness of the laminate is not more than 10 占 퐉. Such a thin polarizer has a condition of P > - (100.929 T - 42.4 - 1) x 100 (provided that T < 42.3) and P? 99.9 (provided that T? 42.3) The optical characteristics are satisfied.

Specifically, the thin polarizer comprises a step of producing a drawn intermediate product comprising a PVA-based resin layer oriented by air high-temperature stretching to a PVA-based resin layer formed on an amorphous ester-based thermoplastic resin base material of a continuous web , A step of producing a colored intermediate product comprising a PVA-based resin layer in which a dichroic substance (preferably a mixture of iodine or iodine and an organic dye) is oriented by adsorption of a dichroic substance to the drawn intermediate product, And a step of producing a polarizer having a thickness of 10 占 퐉 or less and comprising a PVA resin layer in which a dichroic substance is oriented by stretching the product in boric acid water.

In this production method, it is preferable that the total draw ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin base material by public high-temperature stretching and stretching in boric acid water is 5 times or more. The liquid temperature of the boric acid aqueous solution for drawing in boric acid can be 60 占 폚 or higher. It is preferable to carry out the insolubilization treatment of the colored intermediate before drawing the colored intermediate in the aqueous solution of boric acid. In this case, it is preferable to carry out the immersion treatment by immersing the colored intermediate in an aqueous solution of boric acid whose liquid temperature does not exceed 40 캜 Do. The amorphous ester thermoplastic resin base material may be made of copolymerized polyethylene terephthalate copolymerized with isophthalic acid, copolymerized polyethylene terephthalate copolymerized with cyclohexanedimethanol, or amorphous polyethylene terephthalate containing other copolymerized polyethylene terephthalate, The thickness of the PVA-based resin layer is preferably 7 times or more the thickness of the PVA-based resin layer to be formed. The stretching magnification of the air high-temperature stretching is preferably 3.5 times or less, and the stretching temperature of the public high-temperature stretching is preferably not lower than the glass transition temperature of the PVA-based resin, specifically 95 ° C to 150 ° C. When the public high temperature stretching is carried out by free uniaxial stretching, the total draw ratio of the PVA resin layer formed on the amorphous ester type thermoplastic resin base material is preferably 5 times or more and 7.5 times or less. When the public high-temperature stretching is carried out by the fixed single uniaxial stretching, the total stretching ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin base is preferably 5 times or more and 8.5 times or less.

More specifically, a thin polarizer can be produced by the following method.

A substrate of continuous web of isophthalic acid copolymerized polyethylene terephthalate (amorphous PET) in which 6 mol% of isophthalic acid is copolymerized is prepared. The glass transition temperature of the amorphous PET is 75 캜. A laminate composed of an amorphous PET substrate and a polyvinyl alcohol (PVA) layer of a continuous web is prepared as follows. In addition, the glass transition temperature of PVA is 80 ° C.

An amorphous PET substrate having a thickness of 200 탆 and a PVA aqueous solution having a polymerization degree of 1000 or more and a PVA powder having a degree of saponification of 99% or more dissolved in water at a concentration of 4 to 5% are prepared. Next, a PVA aqueous solution is applied to an amorphous PET substrate having a thickness of 200 mu m and dried at a temperature of 50 to 60 DEG C to obtain a laminate having a PVA layer having a thickness of 7 mu m formed on an amorphous PET substrate.

A laminate including a PVA layer having a thickness of 7 占 퐉 is subjected to the following steps including a two-step stretching process of air-assisted stretching and stretching in water of boric acid to prepare a thin, highly functional polarizer having a thickness of 3 占 퐉. A laminate including a PVA layer having a thickness of 7 占 퐉 is integrally stretched with an amorphous PET substrate by an air assisted stretching process of the first stage to produce a stretched laminate including a PVA layer having a thickness of 5 占 퐉. Specifically, this stretched laminate was obtained by putting a laminate including a PVA layer having a thickness of 7 탆 into an oven-oriented stretching apparatus set at a stretching temperature environment of 130 캜, and stretching the stretched film at a stretching ratio of 1.8 It is an extension. By this stretching treatment, the PVA layer contained in the stretched laminate is changed to a PVA layer having a thickness of 5 탆 in which the PVA molecules are oriented.

Next, a colored layered product in which iodine is adsorbed to a PVA layer having a thickness of 5 占 퐉 in which PVA molecules are oriented is produced by a dyeing step. Specifically, this colored layered product is obtained by laminating the drawn laminate to a dyeing solution containing iodine and potassium iodide at a liquid temperature of 30 占 폚, so that the ultimate transmittance of the PVA layer constituting the highly functional polarizer finally produced is 40 to 44% And the PVA layer contained in the stretched laminate is adsorbed to iodine by dipping for an arbitrary time. In the present step, the dyeing solution is prepared so that the concentration of iodine is within a range of 0.12 to 0.30% by weight, and the concentration of potassium iodide is within a range of 0.7 to 2.1% by weight with water as a solvent. The ratio of iodine to potassium iodide is 1 to 7. In addition, potassium iodide is required to dissolve iodine in water. More specifically, the drawn laminate was immersed in a dyeing solution having an iodine concentration of 0.30 wt% and a potassium iodide concentration of 2.1 wt% for 60 seconds to obtain a colored laminate in which iodine was adsorbed on a PVA layer having a thickness of 5 mu m .

Further, the colored laminate is further stretched integrally with the amorphous PET substrate by a stretching process in the second stage of boric acid water to produce an optical film laminate including a PVA layer constituting a highly functional polarizer having a thickness of 3 탆 . Specifically, this optical film laminate is obtained by putting the colored laminate into a drawing apparatus which is arranged in a treating apparatus set in an aqueous boric acid solution containing boric acid and potassium iodide in a liquid temperature range of 60 to 85 ° C, It is a single-axis extension. More specifically, the liquid temperature of the aqueous solution of boric acid is 65 캜. It is also made such that the content of boric acid is 4 parts by mass with respect to 100 parts by mass of water and the content of potassium iodide is 5 parts by mass with respect to 100 parts by mass of water. In this step, the colored laminate having the iodine adsorption amount adjusted is first immersed in an aqueous solution of boric acid for 5 to 10 seconds. After that, the colored layered product is passed through a plurality of sets of rolls different in the main speed, which are the drawing devices arranged in the processing device, and stretched in uniaxial fashion so that the draw ratio is 3.3 times over 30 to 90 seconds. By this stretching treatment, the PVA layer contained in the colored laminate is changed to a PVA layer having a thickness of 3 탆 which is highly oriented in one direction as adsorbed iodine as a polyiodide ion complex. This PVA layer constitutes a highly functional polarizer of the optical film laminate.

The optical film laminate is taken out from the aqueous solution of boric acid by a washing step to remove the boric acid attached to the surface of the PVA layer of 3 占 퐉 thickness formed on the amorphous PET substrate with potassium iodide It is preferable to wash it with an aqueous solution. Thereafter, the cleaned optical film laminate is dried by a drying process by hot air at 60 캜. The cleaning process is a process for eliminating appearance defects such as boric acid precipitation.

The adhesive is applied to the surface of the PVA layer having a thickness of 3 占 퐉 formed on the amorphous PET substrate by a bonding and / or a transferring process, Of triacetylcellulose film, the amorphous PET substrate is peeled off, and a PVA layer having a thickness of 3 占 퐉 may be transferred to a triacetylcellulose film having a thickness of 80 占 퐉.

[Other processes]

The manufacturing method of the thin polarizer may include other steps in addition to the steps described above. Examples of the other steps include an insolubilization step, a crosslinking step, and a drying step (controlling the water content). Other processes can be carried out at any appropriate timing. The above-mentioned insolubilization step is typically performed by immersing a PVA-based resin layer in an aqueous solution of boric acid. By carrying out the insolubilization treatment, it is possible to impart water resistance to the PVA-based resin layer. The concentration of the boric acid aqueous solution is preferably 1 part by mass to 4 parts by mass with respect to 100 parts by mass of water. The liquid temperature of the insoluble body (aqueous solution of boric acid) is preferably 20 ° C to 50 ° C. Preferably, the insolubilization step is carried out after the production of the laminate, before the dyeing step or the underwater stretching step. Typically, the crosslinking step is carried out by immersing the PVA resin layer in an aqueous solution of boric acid. By carrying out the crosslinking treatment, it is possible to impart water resistance to the PVA-based resin layer. The concentration of the boric acid aqueous solution is preferably 1 part by mass to 4 parts by mass with respect to 100 parts by mass of water. Further, in the case of performing the crosslinking step after the dyeing step, it is preferable to further add iodide. By combining iodide, the elution of iodine adsorbed to the PVA-based resin layer can be suppressed. The blending amount of iodide is preferably 1 part by mass to 5 parts by mass with respect to 100 parts by mass of water. Specific examples of the iodide are as described above. The liquid temperature of the crosslinking bath (boric acid aqueous solution) is preferably 20 ° C to 50 ° C. Preferably, the crosslinking step is carried out before the stretching step in the second boric acid water. In a preferred embodiment, a dyeing step, a crosslinking step, and a drawing step in a second aqueous solution of boric acid are carried out in this order.

As a material for forming the transparent protective film formed on one side or both sides of the polarizer, it is preferable that the material is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like. For example, a polyester polymer such as polyethylene terephthalate or polyethylene naphthalate, a cellulose polymer such as diacetylcellulose or triacetylcellulose, an acrylic polymer such as polymethyl methacrylate, a polystyrene or an acrylonitrile styrene copolymer (AS resin), and polycarbonate-based polymers. Examples of the polymer include polyolefin-based polymers such as polyethylene, polypropylene, cyclo- or norbornene-based polyolefins, ethylene-propylene copolymers, vinyl chloride-based polymers, amide-based polymers such as nylon and aromatic polyamides, imide- Based polymer, a polyether sulfone-based polymer, a polyether ether ketone-based polymer, a polyphenylene sulfide-based polymer, a vinyl alcohol polymer, a vinylidene chloride polymer, a vinyl butyral polymer, an arylate polymer, a polyoxymethylene polymer, An epoxy-based polymer, or a blend of the above polymer may be mentioned as an example of the polymer forming the transparent protective film. The transparent protective film may contain one or more optional additives. Examples of the additive include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, colorants and the like. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, particularly preferably 70 to 97% by weight . When the content of the thermoplastic resin in the transparent protective film is 50% by weight or less, there is a possibility that the high transparency and the like inherently possessed by the thermoplastic resin can not be sufficiently exhibited.

Examples of the transparent protective film include a polymer film described in Japanese Patent Application Laid-Open No. 2001-343529 (WO01 / 37007), for example, a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain (A) And a thermoplastic resin having substituted and / or unsubstituted phenyl and nitrile groups in the side chain (B) side chain. Specific examples include films of a resin composition containing an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile styrene copolymer. The film may be a film composed of a mixture of resin compositions and the like. Since these films have a small retardation and a small photoelastic coefficient, problems such as nonuniformity due to deformation of the polarizing film can be solved, and the moisture permeability is small, so that the durability against humidification is excellent.

The thickness of the transparent protective film can be appropriately determined. Generally, the thickness of the transparent protective film is about 1 to 500 占 퐉 in terms of workability such as strength and handleability, and thin layer properties. Particularly preferably 20 to 80 mu m, and more preferably 30 to 60 mu m.

When a transparent protective film is formed on both sides of the polarizer, a transparent protective film made of the same polymer material may be used for the front and back sides, or a transparent protective film made of a different polymer material or the like may be used.

A surface treatment layer such as a hard coat layer, an antireflection layer, a sticking prevention layer, a diffusion layer, or an antiglare layer, which is a cured layer of the curable composition, may be formed on the surface of the transparent protective film on which the polarizer is not adhered.

The polarizing film of the present invention can be used as an optical film laminated with another optical layer in practical use. The optical layer is not particularly limited. For example, a liquid crystal display device such as a reflection plate, a semitransmissive plate, a retardation plate (including a wave plate of 1/2 or 1/4) One or more optical layers that may be used may be used. In particular, a reflection type polarizing film or a semi-transmission type polarizing film in which a reflection plate or a transflective reflection plate is further laminated on the polarizing film of the present invention, an elliptically polarizing film or a circularly polarizing film laminated with a retardation film in addition to the polarizing film, A polarizing film in which a time compensating film is further laminated, or a polarizing film in which a luminance improving film is laminated in addition to a polarizing film.

The optical film obtained by laminating the optical layers on the polarizing film may be formed by sequentially laminating them separately in the process of manufacturing a liquid crystal display device or the like. And the like are advantageous in that the manufacturing process of the liquid crystal display device and the like can be improved. Appropriate adhesion means such as a pressure-sensitive adhesive layer can be used for the lamination. At the time of bonding the polarizing film or other optical films, the optical axes thereof can be set at appropriate arrangement angles in accordance with the desired retardation characteristics and the like.

In the optical film in which at least one polarizing film or polarizing film is laminated, a pressure-sensitive adhesive layer for adhering to other members such as a liquid crystal cell can be formed. As the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer, the above-described pressure-sensitive adhesive composition can be used.

The pressure-sensitive adhesive layer may be formed on one side or both sides of a polarizing film or an optical film as a superposition layer of a different composition or kind. Further, in the case of being formed on both surfaces, a pressure-sensitive adhesive layer such as a composition, kind, thickness, or the like may be formed on the front and back of the polarizing film or the optical film. The thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on the purpose of use and the adhesive force, and is generally 1 to 500 占 퐉, preferably 1 to 200 占 퐉, particularly preferably 1 to 100 占 퐉.

The exposed surface of the pressure-sensitive adhesive layer is covered with a separator for the purpose of prevention of contamination or the like until it is provided for practical use. This makes it possible to prevent contact with the pressure-sensitive adhesive layer in a conventional handling state. As the separator, a suitable thin film such as a plastic film, a rubber sheet, a paper, a cloth, a nonwoven fabric, a net, a foam sheet or a metal foil or a laminate thereof may be used, Such as those obtained by treating with an appropriate stripping agent such as chain alkyl, fluorine-based or molybdenum sulfide, or the like.

The polarizing film or optical film of the present invention can be suitably used for the formation of various devices such as a liquid crystal display device. The formation of the liquid crystal display device can be carried out conventionally. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, a polarizing film or an optical film, and an illumination system as needed, and mounting a driving circuit. In the present invention, Or optical film is used, and there is no particular limitation, and it is possible to follow the conventional method. For the liquid crystal cell, any type of TN type, STN type, or π type, for example, can be used.

A suitable liquid crystal display device such as a liquid crystal display device in which a polarizing film or an optical film is disposed on one side or both sides of the liquid crystal cell and a backlight or a reflector is used in the illumination system can be formed. In this case, the polarizing film or optical film according to the present invention can be provided on one side or both sides of the liquid crystal cell. When polarizing films or optical films are formed on both sides, they may be the same or different. In forming a liquid crystal display device, a suitable part such as a diffusion plate, an anti-glare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, Or more.

Example

Embodiments of the present invention will be described below, but the embodiments of the present invention are not limited thereto.

≪ molar extinction coefficient &

The molar extinction coefficient is measured by dissolving the light emitting material in a solvent (preferably methanol is preferred) and measuring the absorbance at a wavelength of 365 nm using a UV-Vis-NIR spectrometer (Cary 5000) manufactured by Agilent Technologies ≪ / RTI >

A = epsilon Lc

(A represents the absorbance, epsilon represents the molar extinction coefficient (mol ^-1 L · cm ^-1 ), c represents the concentration (mol / l) of the test substance in the solution and L represents the optical path length (cm).

Example 1

(Ethylamino) -s-triazine-2-yl] amino} -7-triazinyl (manufactured by Fuji Photo Film Co., Ltd.) A 50 wt% ethyl acetate solution of vinyl acetate (Gozenil) (manufactured by Nippon Synthetic Chemical Co., Ltd.) in which 0.2 wt% of amino-3-phenyl-coumarin (Hakkol PY1800; manufactured by Showa Kagaku Kogyo) was added was applied by an applicator, And dried at 60 DEG C for 20 minutes. Thereafter, light having a wavelength of 365 nm is irradiated in a direction perpendicular to the film surface, and the amount of light (amount of light) of 420 nm to 480 nm emitted at that time is measured in accordance with the method described in Japanese Patent Application Laid-Open No. 2011-145191 Using a fluorescence measuring apparatus manufactured by Tec Corporation. At this time, the coating thickness was changed by changing the gauge of the applicator so that the thickness after drying was changed to 1 mu m, 2 mu m, and 3 mu m, and the increase or decrease of the amount of light emission was confirmed. The film thickness was measured by a dial gauge.

Example 2, Comparative Examples 1 to 7

Emitting material was changed to that described in the table.

In Tables 1 and 2,

Hakkol P is 8-amino-4-methylcoumarin; Manufactured by Showa Chemical Industry Co.,

IRGACURE 369 is 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1; Manufactured by BASF,

IRGACURE 1173 is 2-hydroxy-2-methyl-1-phenyl-propan-1-one; Manufactured by BASF,

IRGACURE 651 is 2,2-dimethoxy-1,2-diphenylethan-1-one; Manufactured by BASF,

IRGACURE 784 is bis (? 5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium; Manufactured by BASF,

IRGACURE 379 is 2- (dimethylamino) -2 - [(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone; Manufactured by BASF,

IRGACURE OXE01 is 1,2-octanedione, 1- [4- (phenylthio) -2- (o-benzoyloxime)]; Manufactured by BASF,

IRGACURE OXE02 is ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -, 1- (o-acetyloxime); Manufactured by BASF.

≪ Evaluation method of & cir &, &thetas; regarding the preparation of the thickness calibration curve in Tables 1 and 2 &

?: Change in the amount of emitted light by 10 or more when the thickness of the cured layer was changed from 1 占 퐉 to 3 占 퐉

→ It was judged to be possible to make the thickness calibration curve.

X: The amount of light emission was not changed by 10 or more when the thickness of the cured layer was changed from 1 mu m to 3 mu m

→ It was judged that the preparation of the thickness calibration curve was impossible, and it was evaluated as ×.

It can be seen that the thicknesses can be calculated by measuring the amount of emitted light in Examples 1 and 2 in that the amount of emitted light of the cured layer is sufficient and the amount of emitted light varies in proportion to the thickness. On the other hand, in Comparative Examples 1 to 7, since the curable composition containing the polymerization initiator is a cured layer, the amount of emitted light hardly changes even when the thickness varies. Therefore, it can be understood that the thickness of the cured layer can not be calculated based on the amount of emitted light.

Example 3

≪ Production of Polarizer >

A polyvinyl alcohol film having an average degree of polymerization of 2400 and a saponification degree of 99.9 mol% and a thickness of 75 mu m was immersed in hot water at 30 DEG C for 60 seconds to swell. Subsequently, the film was dipped in an aqueous solution having a concentration of 0.3% of iodine / potassium iodide (weight ratio = 0.5 / 8) and stretched to 3.5 times. Thereafter, stretching was carried out in an aqueous solution of boric ester at 65 DEG C such that the total draw ratio was six times. After stretching, the film was dried in an oven at 40 占 폚 for 3 minutes to obtain a PVA polarizer (thickness: 23 占 퐉).

<Transparent protective film>

Transparent Protective Film 1: A triacetylcellulose film having a thickness of 60 占 퐉 was used without saponification, corona treatment, or the like.

Transparent Protective Film 2: A (meth) acrylic resin having a lactone ring structure with a thickness of 40 mu m was subjected to corona treatment and used.

<Active energy ray>

Light Emitter: Bulb, peak illuminance: 1600 mW / cm &lt; 2 &gt;, cumulative irradiation amount 1000 / mJ / cm &lt; 2 &gt; (wavelength: 380 ~ 440 nm) was used. The illuminance of the visible light was measured using a Sola-Check system manufactured by Solatell.

Preparation of active energy ray-curable adhesive composition

5 g of 3 ', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate ("Celloxide 2021P"; manufactured by Daicel Chemical Industries, Ltd.) (Manufactured by Toagosei Co., Ltd.) and 5 g of a cationic photopolymerization initiator ("CPI-100P", a triarylsulfonium salt type photoacid generator, manufactured by San A & And 0.04 g of Hakkol PY-1800 as a light emitting material were mixed in a brown screw tube (No. 5) to prepare an active energy ray curable adhesive composition.

&Lt; Production of polarizing film &gt;

Using the MCD coater (manufactured by Fuji Machinery &amp; Engineering Co., Ltd.) on the above transparent protective films 1 and 2, the active energy ray curable adhesive was coated to thicknesses of 1 μm, 2 μm and 3 μm, Respectively. Thereafter, the visible ray was irradiated from the side of the transparent protective film 1 side by side with an active energy ray irradiating device to cure the active energy ray curable adhesive, followed by hot air drying at 70 DEG C for 3 minutes, To obtain a polarizing film having a film. The line speed of the coupling was 15 m / min. The thickness was measured by cross-sectional SEM observation.

Example 4, Comparative Examples 8 to 14

Emitting material was changed to that described in the table.

In Examples 3 and 4, it can be seen that the light emission amount of the cured layer is sufficient, and the light emission amount varies in proportion to the thickness thereof, whereby the thickness can be calculated by measuring the light emission amount. On the other hand, in Comparative Examples 8 to 14, since the curable composition containing the polymerization initiator is a cured layer, the amount of emitted light hardly changes even when the thickness varies. Therefore, it can be understood that the thickness of the cured layer can not be calculated based on the amount of emitted light.

Claims (11)

An optical film having a cured layer of a curable composition,
Wherein the curable composition contains a light emitting material having a molar extinction coefficient at a wavelength of 365 nm of not less than 10,000 (ℓ / mol · cm). The method according to claim 1,
Wherein the curable composition contains an active energy ray-curable component. 3. The method according to claim 1 or 2,
Wherein the content of the light emitting material is 0.01 to 10 parts by mass when the total amount of the curable composition is 100 parts by mass. 4. The method according to any one of claims 1 to 3,
Wherein the light emitting material is coumarin and a derivative thereof. 5. The method of claim 4,
Wherein the coumarin derivative has a diethylamino group. 6. The method according to any one of claims 1 to 5,
Wherein the optical film is a polarizing film in which a transparent protective film is laminated on at least one surface of a polarizer via an adhesive layer comprising a cured layer of a curable composition. The method according to claim 6,
Wherein the adhesive layer has a thickness of 3 占 퐉 or less. A method for producing an optical film having a cured layer of a curable composition,
A coating step of coating the curable composition on at least one surface of the optical film,
And a cured layer forming step of forming a cured layer by curing the curable composition,
Further comprising the step of measuring the thickness of the cured layer after the cured layer forming step. 9. The method of claim 8,
Further comprising a step of, after the coating step, measuring a coating thickness of the curable composition. 10. The method according to claim 8 or 9,
Wherein the optical film is a polarizing film in which a transparent protective film is laminated on at least one surface of a polarizer via an adhesive layer comprising a cured layer of a curable composition,
A coating step of coating the curable composition on at least one surface of the polarizer and the transparent protective film;
An adhesion step of bonding the polarizer and the transparent protective film,
And a bonding step of bonding the polarizer and the transparent protective film via the adhesive layer obtained by curing the curable composition,
And after the bonding step, measuring the thickness of the adhesive layer. 11. The method of claim 10,
Further comprising the step of measuring the thickness of the curable composition before curing after or after the coating step.