KR101486082B1 - Method of manufacturing laminated film - Google Patents

Abstract

The present invention provides a method for producing a laminated film which bonds films using a photocurable epoxy resin adhesive agent which does not need to be irradiated with light of very high roughness or after heating.

Therefore, the present invention relates to a process for producing a film by using a photocurable epoxy resin adhesive which comprises heating a photocurable epoxy resin adhesive existing between films at a temperature of 40 캜 or higher, To a method for producing a laminated film.

Photocurable epoxy resin adhesive, laminated film

Description

METHOD OF MANUFACTURING LAMINATED FILM < RTI ID = 0.0 >

The present invention relates to a method for producing a laminated film which can be used in a wide variety of fields, and more particularly to a method for producing a laminated film for bonding a film using a photo-curable epoxy resin adhesive.

Laminated films are used in a wide range of fields, including automobiles, aircraft, and electrical and electronic devices. Particularly, in recent years, laminated films in electric and electronic devices are becoming more diverse and advanced. With regard to the diversification and advancement of the laminated film and the production method of the laminated film, improvement of the productivity, improvement of the yield, simplification of the apparatus, and automation are required while maintaining the quality of the laminated film to be produced.

For example, a polarizer used in an optical member or a liquid crystal display device is generally manufactured by bonding a protective film or an optical compensation film to both sides of a polyvinyl alcohol (PVA) polarizer film with an adhesive. As such adhesives, water-based adhesives and organic solvent-based adhesives have been used, but in recent years, non-aqueous and non-aqueous solvent based costbased adhesives, in particular, photosetting epoxy resin adhesives have been used.

Conventionally, in the production of a laminated film using a photo-curable epoxy resin adhesive as an adhesive, in order to sufficiently cure the photo-curable epoxy resin adhesive, it is necessary to accelerate the curing reaction by irradiating heat or heat of reaction, It is necessary to complete the curing reaction (post cure) by heating with an oven or the like. When the photocurable epoxy resin adhesive is irradiated with light, the photopolymerization initiator (catalyst) contained therein is activated to generate an acid. This acid reacts with the epoxy group of the photocurable epoxy resin, and the epoxy group is opened to generate carbanion ions. The carbanion ions successively react with the epoxy group of the epoxy resin to cure the epoxy resin adhesive. However, since the reaction between the carbanion ion and the epoxy group is a reaction that is difficult to occur at room temperature, it is necessary to accelerate or complete the reaction between the carbanion ion and the epoxy group by irradiating light of strong illumination or by heating with an oven etc. there was.

When irradiated with a strong light, the light is turned into heat. For example, in the case of a polarizer film, iodine dropout occurs from a polyvinyl alcohol film (deflector film) dyed with iodine or the like, or a polarizer film, The optical compensation film is deformed to deteriorate the quality.

Further, in the case of heating in an oven or the like after light irradiation, a heating device such as a heating oven is required. Especially, when the line speed is high, the heating oven becomes very long and the operation cost is increased.

It is an object of the present invention to provide a laminated film for bonding a film using a photo-curable epoxy resin-based adhesive, which does not need to irradiate light with a high degree of illumination or sufficiently heat (postcure) after light irradiation for sufficiently curing the photo-curable epoxy resin- And a method for manufacturing the same.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have found that the above problems can be achieved by warming the photo-curable epoxy resin adhesive to a specific temperature before irradiation with light. Based on these findings, I have come to completion.

According to the present invention, the following first to fourth inventions are provided.

(1) bonding a film using a photocurable epoxy resin adhesive, which comprises heating a photocurable epoxy resin adhesive existing between the films at a temperature of 40 캜 or higher and irradiating the adhesive with light to cure the film A method for producing a laminated film.

(2) a cationic cationically curable epoxy resin-based adhesive which is present between the films is heated at a temperature not higher than the heat-resistant temperature of the film at 40 DEG C or higher, A method for adhering a polarizer film to a protective film and / or an optical compensation film using an epoxy resin adhesive.

(3) The method according to (1) or (2), wherein the heating temperature is 40 to 120 占 폚.

(4) The method according to any one of (1) to (3), wherein the light is ultraviolet light in which at least a part of the light having a wavelength of 400 nm or less is blocked.

According to the manufacturing method of the present invention, it is not necessary to irradiate light with strong illumination or to heat (post-cure) after light irradiation in order to sufficiently cure the photo-curable epoxy resin adhesive. Therefore, a laminated film such as a polarizing plate Can be efficiently produced.

Hereinafter, the present invention will be described in detail.

The photocurable epoxy resin-based adhesive used in the present invention contains a photocurable epoxy resin and a photopolymerization initiator, but may also contain other generally accepted additives.

The photo-curable epoxy resin is not particularly limited as long as it is a generally used photo-curable epoxy resin, and includes, for example, aromatic epoxy resin, aliphatic epoxy resin, alicyclic epoxy resin and the like.

Examples of the aromatic epoxy resin include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a naphthalene skeleton epoxy resin, and a phenol novolak type epoxy resin.

As the aliphatic epoxy resin, a polyglycidyl ether of an aliphatic polyhydric alcohol or an alkylene oxide adduct thereof may be used. Examples of the aliphatic epoxy resin include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylol propane triglycidyl ether, trimethylol propane diglycidyl ether, and polyethylene glycol diglycidyl ether. . Unsaturated fatty acid epoxies such as butadiene-based epoxy resins and isoprene-based epoxy resins can also be used. Trimethylolpropane triglycidyl ether and trimethylolpropane diglycidyl ether are preferred because of their low viscosity. Examples of commercially available products of aliphatic epoxy resins include Epolite 100MF (trimethylolpropane triglycidyl ether) manufactured by Kyoeisha Chemical Co., Ltd., EX-321L (trimethylol propane) manufactured by Nagase Chemtex Co., Diglycidyl ether).

The alicyclic epoxy resin is a compound having at least one epoxy group bonded to an alicyclic ring in the molecule, and examples thereof include vinylcyclohexene monoxide, 1,2-epoxy-4-vinylcyclohexane, 1,2: 8,9 Diepoxy limonene, 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexene carboxylate, and the like. These are commercially available from Daicel Chemical Industries, Ltd. under the trade names CEL2000, CEL3000 and CEL2021P.

As the photocurable epoxy resin in the present invention, the above-mentioned epoxy resin may be used alone, or a plurality of kinds of epoxy resins may be mixed in an arbitrary ratio.

The photopolymerization initiator in the present invention is not particularly limited as long as it generates a cation or a Lewis acid by irradiation of an active energy ray such as visible light, ultraviolet ray, X-ray or electron ray to initiate polymerization of an epoxy group. Examples of the photopolymerization initiator include sulfonium salts, iodonium salts and diazonium salts.

As examples of the sulfonium system, for example,

Triphenylsulfonium hexafluorophosphate,

Triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate,

Triphenylsulfonium tetrakis (pentafluorophenyl) borate,

4,4'-bis [diphenylsulfonio] diphenylsulfide bis hexafluorophosphate,

4,4'-bis [di (beta -hydroxyethoxy) phenylsulfonio] diphenylsulfide bis hexafluoroantimonate,

4,4'-bis [di (? - hydroxyethoxy) phenylsulfonio] diphenylsulfide bis hexafluorophosphate,

7- (di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluoroantimonate,

7- (di (p-toluyl) sulfonio] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate,

4-phenylcarbonyl-4'-diphenylsulfone-diphenylsulfide hexafluorophosphate,

4- (p-tert-butylphenylcarbonyl) -4'-diphenylsulfonio-diphenylsulfide hexafluoroantimonate,

(P-tert-butylphenylcarbonyl) -4'-di (p-toluyl) sulfonio-diphenylsulfide tetrakis (pentafluorophenyl) borate

And the like.

As an example of the iodonium salt system, for example,

Diphenyl iodonium tetrakis (pentafluorophenyl) borate,

Diphenyl iodonium hexafluorophosphate,

Diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluoroantimonate,

Di (4-nonylphenyl) iodonium hexafluorophosphate

And the like.

As examples of the diazonium salt, for example,

Benzene diazonium hexafluoroantimonate, benzene diazonium hexafluoroantimonate,

Benzene diazonium hexafluorophosphate

And the like.

ADEKA OPTOMER SP-150 and SP-170 manufactured by Asahi Denka Kogyo Co., Ltd., PI2074 manufactured by Rhodia Co., Ltd., Kayalard PCI-220 manufactured by Nippon Kayaku Co., .

These photopolymerization initiators are used in an amount of 0.5 to 20 parts by mass, preferably 1 to 10 parts by mass, based on 100 parts by mass of the photocurable epoxy resin. Each of the photopolymerization initiators may be used alone or in combination of two or more.

The photocurable epoxy resin-based adhesive in the present invention may contain an oxetane compound if necessary. The oxetane compound is a compound having a 4-membered ring ether in the molecule, that is, an oxetane ring. Examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis [{(3-ethyl-3-oxetanyl) methoxy} (3-ethyl-3-oxetanylmethyl) ether, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane) Triethoxysilylpropoxy) methyl} oxetane], oxetanylsilsesquioxane, phenol novolak oxetane, and the like. Among these oxetane compounds, 3-ethyl-3-hydroxymethyloxetane, bis (3-ethyl-3-oxetanylmethyl) desirable. Examples of commercial products of oxetane compounds include OXT-101 (3-ethyl-3-hydroxymethyloxetane), OXT-211 (3-ethyl-3- (3-ethylhexyloxymethyl) oxetane), OXT-221 (di [1-ethyl (3-oxetanyl)] methyl ether), OXT- have.

In the present invention, the oxetane compound is used in an amount of 50 parts by mass or less based on 100 parts by mass of the photocurable epoxy resin. The oxetane compounds may be used alone or in combination of two or more.

The photosetting epoxy resin adhesive in the present invention may further contain a photosensitizer as required. By using a photosensitizer, the reactivity can be improved and the mechanical strength and adhesive strength of the cured product can be improved. Examples of the photosensitizer include carbonyl compounds, organic sulfur compounds, persulfates, redox compounds, azo and diazo compounds, halogen compounds, and photo-reducible dyes. Examples of photosensitizers include benzoin derivatives such as benzoin methyl ether, benzoin isopropyl ether,?,? -Dimethoxy-? -Phenylacetophenone; Benzophenone derivatives such as benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, and 4,4'-bis (diethylamino) benzophenone; Thioxanthone derivatives such as 2-chlorothioxanthone, 2-isopropylthioxanthone and 2,4-diethylthioxanthone; Anthraquinone derivatives such as 2-chloro anthraquinone and 2-methyl anthraquinone; Acridone derivatives such as N-methyl acridone, N-butyl acridone; Anthracene derivatives such as 9,10-dibutoxyanthracene; Other examples include, but are not limited to, alpha, alpha -diethoxyacetophenone, benzyl, fluorenone, xanthone, uranyl compound, halogen compound, and photoreactive dye. These may be used alone or in combination of two or more. Commercially available products of the photosensitizer include, for example, Kayacure DETX-S (manufactured by Nippon Kayaku Co., Ltd.). The amount of the photosensitizer is 0.01 to 20 parts by mass, preferably 0.1 to 5 parts by mass based on 100 parts by mass of the photocurable epoxy resin adhesive.

The photocurable epoxy resin adhesive in the present invention may further contain additives other than the above, for example, a filler, an antioxidant and a silane coupling agent as long as the effect of the present invention is not impaired.

Examples of the filler include inorganic fillers such as talc, silica and mica, and resin fillers such as polypropylene and polyethylene.

Examples of the antioxidant include dibutylhydroxytoluene (BHT), Irganox 1010, Irganox 1035FF, Irganox 565, and the like.

Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Methacryloxypropyltrimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) -methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, Propylamine and the like.

Examples of commercial products of the silane coupling agent include epoxy-based (e.g. KBM403, KBM303), vinyl-based (KBM1003), acrylic silane coupling agent (KBM503), 3- ethyl (triethoxysilylpropoxymethyl) oxetane TESOX (manufactured by Toagosei Co., Ltd.)) and the like.

The photocurable epoxy resin adhesive in the present invention preferably has a viscosity of 200 mPa 占 퐏 (25 占 폚) or less, more preferably 150 mPa 占 퐏 (25 占 폚) or less. The lower the viscosity, the easier to apply and the thinner the coating thickness of the adhesive layer. For example, when used for bonding a protective film or optical compensation film to a polarizing plate, the appearance of the polarizing plate becomes better. An adhesive having a high viscosity can also be used, but in this case, the application amount is reduced.

The film used in the present invention must be a film through which at least one film transmits light. As such a light-transmitting film, a polyester film, a polycarbonate film, an acrylic film, a polyamide film, a polyimide film, an amorphous polyolefin film, a cycloolefin film, a PVA film, .

The amorphous polyolefin-based resin usually has a polymerization unit of a cyclic polyolefin such as norbornene or a polycyclic norbornene monomer, and may be a copolymer of a cyclic olefin and a cyclic olefin. Commercially available amorphous polyolefin resins include ATON, trade name of JSR Corporation, ZEONEX, ZEONOR of Nippon Zeon Co., Ltd., APO and APEL of Mitsui Chemicals, Inc.

In the present invention, a film that does not transmit light in combination with a film that does not transmit light can also be used as a base film of, for example, a laminated film. As such a film that does not transmit such light, for example, a resin such as a colored pigment, a colored dye, a carbon black, an inorganic particle or a polymer fine particle for the purpose of coloring or shading, a resin having a light transmittance in a wavelength region of 450 nm or less And polyimide films free from the above.

The thickness of each film of the present invention is not particularly limited, and films of various thicknesses can be used depending on the application.

When the laminated film is a polarizing plate, a PVA-based polarizer film, a cellulose-based film such as triacetylcellulose, a cycloolefin-based film, or a protective film or an optical compensation film can be used.

In the present invention, the coating method of the photocurable epoxy resin adhesive to the base film is not particularly limited and includes, for example, a method using a doctor blade, a wire bar, a die coater, a comma coater, a gravure coater and the like. Further, the laminate of the film of the present invention can be performed using a metal roll, a rubber roll or the like, and the lamination pressure at this time may be 0 to 5 MPa.

The laminated film of the present invention may have a laminated structure composed of two layers, three layers, four layers, five layers, six layers or more.

In the present invention, it is possible to use a film obtained by applying a corona treatment, a plasma treatment, an excimer treatment, a UV treatment, or the like to the bonding side of the film.

The heating temperature of the photocurable epoxy resin-based adhesive of the present invention is required to be 40 占 폚 or higher. The upper limit of the heating temperature is the heat resistance temperature of the adherend film, which can not be uniformly limited because it depends on the heat resistance of the adherend film. Here, the heat-resistant temperature of the film is a temperature at which the optical characteristics (transmittance and degree of polarization) of the film are not deteriorated without substantially deforming (warping or deforming) the film as compared with that before heating when the film is placed at a constant temperature for 60 seconds It refers to the highest temperature. If the heating temperature of the adhesive is 40 DEG C or lower, the curing of the photocurable epoxy resin by light irradiation is not sufficient and the effect of the present invention can not be attained. The heating temperature of the adhesive is preferably 50 to 100 占 폚, more preferably 60 to 80 占 폚.

The heating of the photo-curable epoxy resin adhesive in the present invention can be performed by, for example, a near-infrared halogen lamp, a far-infrared heater, hot air, a hot plate, or a heating roller.

The light in the present invention refers to active energy rays such as visible light, ultraviolet light, X-rays, and electron beams, and is preferably ultraviolet light. The light irradiation can be performed using a metal halide lamp, a high-pressure mercury lamp, a xenon lamp, a halogen lamp, or the like. In the case of using ultraviolet rays, at least a part of light with a wavelength of 400 nm or less, preferably 390 nm or less, more preferably 400 nm or less, preferably 390 nm or less Ultraviolet rays not including all of light are preferable. This ultraviolet ray can be obtained, for example, by using a near infrared ray cut filter between an ultraviolet lamp and an adherend film or an optical filter for blocking light of a wavelength of 310 or 390 nm or less. Examples of such optical filters include quartz glass, a heat ray cut filter (IRCF), a cut filter of 310 nm or less, a 320 nm cut filter, a 340 nm cut filter, a 390 nm cut filter, a soda lime glass, .

The light irradiation according to the present invention is carried out when the temperature of the photo-curable epoxy resin adhesive is 40 占 폚 or higher. The irradiation intensity of light in the present invention differs depending on the intended adhesive or resin film, and is not limited, but it is preferable that the irradiation intensity in the wavelength range effective for activation of the photopolymerization initiator is 10 to 500 mW / cm ² . The irradiation time of light differs depending on the type of the photocurable epoxy resin used and the material of the film to be used, and is not limited. However, the integrated amount of light expressed as a product of irradiation intensity and irradiation time is 100 to 3000 mJ / cm ² (wavelength 405 mm ), Preferably 700 to 2000 mJ / cm ² (wavelength 405 nm).

<Examples>

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples.

Production Examples A to F: Production of a photocurable epoxy resin-based adhesive

(Viscosity: 150 mPa / s (25 캜)) was obtained by mixing and stirring the mixture in a stirrer to obtain a uniform photo-curable epoxy resin-based adhesive.

100MF: trimethylol propane triglycidyl ether, Kyoeisha Chemical Co.,

Epiclon EXA-850S: 4,4'-diglycidyloxy-2,2'-diphenylpropane, manufactured by Dainippon Ink and Chemicals,

Epiclon N740: phenol novolak type epoxy oligomer, Dainippon Ink Chemical Co.,

CEL 2000: 1,2-epoxy-4-vinylcyclohexane,

CEL3000: 1,2: 8,9 diepoxy limonene, Daicel Chemical Industry Co.,

CEL2021P: 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexene carboxylate, Daicel Chemical Industries, Ltd.

CPI-101A: photopolymerization catalyst,

SP-172: Photopolymerization catalyst, Adeka Co., Ltd.

KBM403: 3-glycidoxypropyltrimethoxysilane, Shinetsu Chemical Industry Co.,

DBA: 9,10-dibutoxyanthracene, Kawasaki Kasei Kogyo Co.,

Examples 1 to 6 and Comparative Examples 1 to 3: Production of laminated film (polarizing plate)

A triacetyl cellulose film was uniaxially stretched and a polyvinyl alcohol polarizer film stained with iodine was coated with a triacetyl cellulose film on one side and an amorphous polyolefin resin film (Zeonor film manufactured by Nippon Zeon Co., Ltd.) (Symbol: A) to obtain a film having a three-layer structure. The obtained three-layer film was heated to room temperature (25 ° C), 30 ° C, 40 ° C, 50 ° C, 60 ° C, 70 ° C, 80 ° C, 100 ° C, 120 ° C and 140 ° C using an infrared lamp, Immediately, a laminated film was obtained by irradiating light with an irradiation intensity of 200 mW / cm ² (405 nm) and a cumulative light quantity of 1000 mJ / cm ² (405 mm) using a metal halide lamp (manufactured by Eye Graphics Co., Ltd.). The adhesive layer between the laminated films was uniform to a thickness of about 1 to 3 mu m. These were confirmed by electron microscopy.

Table 2 shows the material temperature, the state of the adhesive after UV irradiation, the deformation of the laminated film after UV irradiation, the durability characteristics of the laminated film, and the optical characteristics after the moisture resistance test.

Material temperature: The temperature of the adhesive immediately before UV irradiation (heating temperature)

The state of the adhesive after UV irradiation:

And evaluated according to the following criteria.

   Insufficient curing in liquid phase: insufficient curing in liquid state

   Peeling: film peeled off

   ?: Bonded but slightly weaker (~ 100 g / 25 mm)

   ?: Adhesive, medium strength (100 to 200 g / 25 mm)

   ◎: Adhered and sufficient strength (200 g / 25 mm)

Deformation of film after UV irradiation: Observed with naked eyes.

Endurance characteristics after humidity test:

The appearance (discoloration or film denaturation) after the laminated film was allowed to stand for 500 hours in a humidity resistant test tank under the condition of 60 占 폚 -90% was evaluated based on the following criteria.

  X: Stripping, distortion, and discoloration of the polarizer portion occur strongly.

  Δ: peeling, deformation, discoloration of the polarizer portion occurred.

  ○: Discoloration of the polarizer portion occurs very little, but peeling and deformation do not occur.

  ⊚: No peeling or distortion, no discoloration of the polarizer portion.

Optical properties after humidity test:

The polarized light and transmittance of the laminated film before and after the humidity resistance test were measured and evaluated by their deterioration (decrease from the value of the laminated film before humidity resistance test).

* Degeneration (deformation, durability, optical properties) of the adherend material was not only caused by heat but also by ultraviolet rays.

From Table 2, it can be seen that when light is irradiated after heating to 40 to 70 占 폚, the photocurable epoxy resin adhesive is sufficiently cured to exhibit good adhesiveness, and the film is hardly deformed. On the other hand, when the heating temperature was 25 占 폚 or 30 占 폚, there was no deformation of the film, but the photosetting epoxy resin adhesive was insufficiently cured or uncured, and the adhesiveness was very poor. When the curing temperature is 80 to 100 ° C or more, the photocurable epoxy resin adhesive is sufficiently cured to exhibit good adhesion, but the film is slightly warped. On the other hand, when the temperature exceeds 100 ° C, the photocurable epoxy resin adhesive is sufficiently cured to exhibit good adhesion, but the film is greatly denatured.

The same examination was conducted on the photo-curable resin adhesives B to F, and as a result, almost the same results were obtained although the adhesiveness was somewhat different.

On the other hand, a laminated film having the same performance as that described above was obtained in the case where the heating was performed with a hot plate instead of the infrared lamp, or when the film was heated by hot air.

Examples 7 to 13 and Comparative Examples 4 to 6: Preparation of laminated film

In the production of the laminated films of Examples 1 to 6 and Comparative Examples 1 to 3, an optical filter (manufactured by Eye Graphics Co., Ltd.) for blocking light having a wavelength of 390 nm or less was placed between the metal halide lamp and the adherend film, Respectively. The laminated films of Examples 7 to 13 and Comparative Examples 4 to 6 were obtained in the same manner as in Examples 1 to 6 and Comparative Examples 1 to 3, respectively.

It can be seen from Table 3 that when the optical filter for shielding light having a wavelength of 390 nm or less is disposed between the metal halide lamp and the adherend, the degree of degeneration of the polarizer and the film is small, A film was obtained. The same results were obtained when a wavelength cut filter of 320 nm or less, a wavelength cut filter of 340 nm or less, or a wavelength cut filter of 370 nm or less was used in place of the wavelength cut filter of 390 nm or less, but the use of a wavelength cut filter of 390 nm or less The effect on the most constituting film was small. The use of an optical filter can suppress the deformation of the film when heated to 120 캜, but the deformation of the film when heated to 140 캜 could not be suppressed.

Comparative Examples 7 to 12: Production of laminated film

A film having a three-layer structure was obtained in the same manner as in Example 1. The obtained three-layer structure film was irradiated with light having an irradiation intensity of 500 mW / cm ² (405 nm), a cumulative light quantity of 500, 1000, 2000 and 3000 mJ / cm ² (405 nm) using a metal halide lamp ) To obtain a laminated film. In the case of the cumulative light quantity of 2000 and 3000 mJ / cm ² (405 nm), an optical filter (manufactured by Eye Graphics Co., Ltd.) disposed between the metal halide lamp and the adherend film to block light having a wavelength of 390 nm or less is used Followed by irradiation to obtain a laminated film.

From Table 4, it was not possible to obtain a laminated film having excellent adhesiveness and no deformation of the film even when the amount of light irradiated was increased or decreased in the case of not heating before light irradiation.

INDUSTRIAL APPLICABILITY The present invention can be used in the production of laminated films for use in a wide range of industrial fields including automobiles, aircraft, electric and electronic devices. Further, since it is a process having fast curing property and quick adhesion property, it greatly contributes to improvement of the production speed and reduction of the heating process.

Claims (4)

A process for producing a laminated film in which a film is bonded using a photocurable epoxy resin adhesive, A step of heating the photo-curable epoxy resin adhesive existing between the films at a temperature of 40 to 120 占 폚, and curing the film by irradiating light thereto to adhere the film, wherein the laminated film is a polarizing plate . The method for producing a laminated film according to claim 1, wherein at least one of the protective film and the optical compensation film is bonded to the polarizer film. delete 3. The method according to claim 1 or 2, wherein ultraviolet rays in which at least a part of light having a wavelength of 390 nm or less is blocked is used as light.