JP6871487B1 - Manufacturing method of photocurable resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress poor peeling between a photocurable resin film and a base film and / or a cover film after photocuring in a method for producing a photocurable resin film containing an ultraviolet absorber. To do. SOLUTION: At least one layer of a photocurable resin composition composed of a liquid photocurable resin composition containing an ultraviolet absorber and a photopolymerization initiator is formed on one surface of a base film to form a laminate. After that, the photocurable resin composition layer is cured by irradiating the photocurable resin composition layer with ultraviolet rays from at least one surface of the laminate on the base film side and the photocurable resin composition layer side. , A method for producing a photocurable resin film, in which at least one of ultraviolet rays is irradiated with ultraviolet rays by a light source having an emission peak only in the ultraviolet absorption wavelength band of the photopolymerization initiator, and the transmission intermediate wavelength of the base film is set to λBF (. nm), the transmission intermediate wavelength of the ultraviolet absorber having the largest transmission intermediate wavelength value among the ultraviolet absorbers is λA (nm), the emission peak wavelength of the light source on the base film side is λBL (nm), and the photocurable resin composition. A method for producing a photocurable resin film, characterized in that λBF <λA <λBL and / or λA <λRL when the wavelength of the emission peak of the light source on the material layer side is λRL (nm). [Selection diagram] Fig. 1

Description

The present invention relates to a method for producing a photocurable resin film, which forms a hard film by curing a liquid photocurable resin composition mainly by irradiating light in an ultraviolet region.

Photocurable resin films such as acrylics have the property of being less likely to break than glass. For this reason, in recent years, it has come to be widely used in fields where glass has been conventionally used. Further, the photocurable resin film has higher heat resistance and hardness than the thermoplastic resin film, and is expected to be used in new fields of application where heat resistance and hardness are required. For example, for decorative molding, there is an insert film in which a pattern is printed on the surface of the film and then three-dimensionally molded in a state of being softened by heating. Photocurable resin films used for decorative molding are required to have ultraviolet blocking properties, and in many cases, an ultraviolet absorber is added.

So far, several methods have been proposed for producing a film made of a photocurable resin. For example, in Japanese Patent Application Laid-Open No. 2006-306081 (Reference 1), a liquid photocurable resin is cast on a smooth base film in the form of a film to form a photocurable resin layer, and the photocurable resin layer is overlaid. Disclosed is a method of producing a photocurable resin film by laminating a smooth ultraviolet-transmitting cover film on the surface to form a laminate and then irradiating the laminate with ultraviolet rays.

However, when a photocurable resin film containing an ultraviolet absorber is produced by the above-mentioned production method, a peculiar problem arises due to the inclusion of the ultraviolet absorber. That is, when a photocurable resin composition containing an ultraviolet absorber is cured by irradiating it with ultraviolet rays, the heat generated when the ultraviolet absorber absorbs the ultraviolet rays is added to the normal heat of the photocuring reaction. Therefore, the temperature of the laminate is higher than that in the case where the photocurable resin composition containing no ultraviolet absorber is cured by irradiation with ultraviolet rays. Further, since a part of the ultraviolet rays contributing to the curing reaction is absorbed by the ultraviolet absorber, it becomes difficult for the ultraviolet rays to reach the polymerization initiator. In order to proceed with the curing reaction and increase the reaction rate, it is necessary to increase the total amount of light (integrated light amount) irradiating the photocurable resin composition, but the total amount of light irradiating the photocurable resin composition is large. Then, the temperature of the laminated body rises. An increase in the temperature of the laminate causes poor peeling between the photocurable resin film after photocuring and the base film and / or cover film, and hinders stable winding of the photocurable resin film.

In order to solve the peeling failure due to the temperature rise of the laminated body, Document 1 discloses that the laminated body is cooled and cured at a temperature lower than the glass transition temperature of the base film and the cover film, and is subjected to ultraviolet irradiation. The laminated body is cooled by air cooling in which cold air is blown from the base film side in a smooth state pinched between pinch rolls. However, air cooling has poor cooling efficiency, and if the air volume of cold air is increased in order to obtain a sufficient cooling effect, the laminated body flutters, causing the obtained photocurable resin film to have poor appearance such as wrinkles and deformation.

On the other hand, the cooling method using a cooling roll in which the ultraviolet irradiation device is arranged along the outer periphery of the cooling roll has good cooling efficiency, and therefore cures a resin layer having a relatively thin thickness such as forming a hard coat layer on the surface of an optical film. It is used in the case of. However, in the cooling method using a cooling roll, the photocuring reaction proceeds in a state where the laminated body has a curvature. Therefore, when it is applied to photocuring of a relatively thick material such as a film, it is photocured in the curing process. It cannot be applied because distortion and stress difference occur between the roll contact surface and the non-contact surface of the mold resin film, and it is difficult to obtain a smooth film.

As described above, a method for producing a new photocurable resin film that suppresses poor peeling between the photocurable resin film after photocuring and the base film and / or the cover film in the photocurable resin film containing an ultraviolet absorber. Is required.

The term ultraviolet light in the present invention includes visible light having a wavelength of 410 nm or less.

Japanese Unexamined Patent Publication No. 2006-306081

An object of the present invention is to suppress poor peeling between a photocurable resin film after photocuring and a base film and / or a cover film, which occurs in a method for producing a photocurable resin film containing an ultraviolet absorber. ..

That is, according to the present invention, in order to solve the above problems, at least one layer of a photocurable resin composed of a liquid photocurable resin composition containing an ultraviolet absorber and a photopolymerization initiator on one surface of the base film. After the composition layer is formed to form a laminated body, ultraviolet rays are applied to the photocurable resin composition layer from at least one surface of the laminated body on the base film side and the photocurable resin composition layer side. A method for producing a photocurable resin film in which the photocurable resin composition layer is cured by irradiation. At least one of the ultraviolet rays has an emission peak only in the ultraviolet absorption wavelength band of the photopolymerization initiator. The transmission intermediate wavelength of the base film is λ _BF (nm), and the transmission intermediate wavelength of the ultraviolet absorber having the largest transmission intermediate wavelength value among the ultraviolet absorbers is λ _A (nm). When the wavelength of the emission peak of the light source on the base film side is λ _BL (nm) and the wavelength of the emission peak of the light source on the photocurable resin composition layer side is λ _RL (nm), λ _BF <λ _A <λ Provided is a method for producing a photocurable resin film, characterized in that _BL and / or λ _A <λ _RL.

Further, after forming at least one layer of a photocurable resin composition layer composed of a liquid photocurable resin composition containing an ultraviolet absorber and a photopolymerization initiator between the base film and the cover film to form a laminate. The photocurable resin composition layer is cured by irradiating the photocurable resin composition layer with ultraviolet rays from at least one surface of the laminate on the base film side and the cover film side. A method for producing a photocurable resin film, at least one of the ultraviolet rays is irradiated by a light source having an emission peak only in the ultraviolet absorption wavelength band of the photopolymerization initiator, and the transmission intermediate wavelength of the base film is set to λ _BF. (Nm), the transmission intermediate wavelength of the cover film is λ _CF (nm), the transmission intermediate wavelength of the ultraviolet absorber having the largest transmission intermediate wavelength value among the ultraviolet absorbers is λ _A (nm), and the base film side. When the wavelength of the emission peak of the light source is λ _BL (nm) and the wavelength of the emission peak of the light source on the cover film side is λ _CL (nm), λ _BF <λ _A <λ _BL and / or λ _CF <λ _A method for producing a photocurable resin film, characterized in that A <λ _{CL, is provided.}

Further, the laminate is formed by casting a liquid photocurable resin composition containing an ultraviolet absorber and a photopolymerization initiator on the base film in the form of a film, whereby at least one layer of the photocurable resin composition is formed. Provided is a method for producing the photocurable resin film, which comprises forming a material layer and laminating the cover film on the photocurable resin composition layer.

Further, before laminating the cover film on the photocurable resin composition layer, at least one layer of an ultraviolet absorber and light is previously applied to the surface of the cover film on the photocurable resin composition layer side. Provided is the method for producing a photocurable resin film, which comprises forming a layer made of a liquid photocurable resin composition containing a polymerization initiator.

Further provided, a method for producing the photocurable resin film, wherein the base film and / or the cover film is a polyester film.

Further, there is provided a method for producing the photocurable resin film, wherein the transmission intermediate wavelength A _{λ of the ultraviolet absorber is 350 nm or more.}

According to the method for producing a photocurable resin film of the present invention, it is possible to suppress heat generation during curing by ultraviolet irradiation and suppress a temperature rise of the laminate. Therefore, the photocurable resin film and the base after photocuring can be suppressed. It is possible to stably and continuously produce a roll film by eliminating poor peeling from the film and / or the cover film. Therefore, the present invention capable of stably producing such a photocurable resin film has extremely high industrial utility value.

It is the schematic of the manufacturing method of the photocurable resin film which concerns on one Embodiment of this invention. It is the schematic of the manufacturing method of the photocurable resin film which concerns on one Embodiment of this invention. It is the schematic of the manufacturing method of the photocurable resin film which concerns on one Embodiment of this invention. It is the schematic of the manufacturing method of the photocurable resin film which concerns on one Embodiment of this invention. It is explanatory drawing of the definition of transmission intermediate wavelength in this invention. It is a figure which showed the relationship between the ultraviolet absorption spectrum of a photopolymerization initiator, the ultraviolet transmission spectrum of an ultraviolet absorber, and the emission spectrum of a light emitting diode (hereinafter referred to as LED) having an emission peak of 405 nm in the production method of Example 1. is there. It is a figure which showed the relationship between the ultraviolet absorption spectrum of a photopolymerization initiator, the ultraviolet transmission spectrum of an ultraviolet absorber, and the emission spectrum of an electrodeless ultraviolet lamp (manufactured by Heleus Co., Ltd., H valve) in the production method of Comparative Example 1.

Hereinafter, preferred embodiments of the method for producing a photocurable resin film of the present invention will be described in detail with reference to the drawings as necessary.

FIG. 1 is a schematic view according to an embodiment of the method for producing a photocurable resin film of the present invention. As shown in FIG. 1, in the present invention, a liquid photocurable resin composition which is a raw material of a photocurable resin film is cast on the base film 11 in the form of a film, and the photocurable resin is spread on the base film 11. The composition layers are laminated. The photocurable resin composition is supplied from the coating head 12 onto the base film 11 in fixed amounts. The base film 11 is continuously drawn from a roll of a polyester film or the like at a constant speed according to the supply amount of the photocurable resin composition. The photocurable resin composition is supplied on the base film 11 so as to have a thickness of, for example, 20 to 300 μm.

In the present invention, even if a plurality of photocurable resin compositions are laminated in a film form on the base film 11 and cast to form a photocurable resin film having a plurality of photocurable resin composition layers. Good. In this case, a plurality of coating heads may be installed or a multi-layer coating head may be used. When a photocurable resin film having a plurality of photocurable resin composition layers is produced, the thickness of each layer is preferably 20 μm or more.

Further, in the present invention, as shown in FIG. 2, a coating head is previously applied to the surface of the cover film 13 on the photocurable resin composition layer side before laminating the cover film 13 to form the laminated body 14. 122 may be used to form at least one layer of the photocurable resin composition. When a plurality of layers made of the photocurable resin composition are formed on the cover film 13, a plurality of coating heads 122 may be installed or a multilayer coating head may be used.

The photocurable resin composition used in the present invention contains a photocurable resin, a photopolymerization initiator, and an ultraviolet absorber. The photocurable resin used in the present invention is classified into, for example, a radical polymerization type photocurable resin and a cationic polymerization type photocurable resin according to its reaction mechanism, and both can be used. The radical polymerization type photocurable resin contains, for example, a polymerizable monomer such as an acrylate monomer or a polymerizable oligomer such as a urethane acrylate, a polyester acrylate, an epoxy acrylate or an acrylic acrylate as a raw material. Examples of the radical polymerization type photopolymerization initiator include benzophenone-based, acetophenone-based, and thioxanthone-based compounds. The cationically polymerizable photocurable resin contains, for example, a polymerizable monomer such as a vinyl ether monomer or a polymerizable oligomer such as a vinyl ether oligomer, an alicyclic epoxy resin, or a glycidyl ether epoxy as a raw material. Examples of the cationic polymerization type photopolymerization initiator include sulfonium-based and iodonium-based compounds. The photocurable resin composition has a viscosity adjusted to, for example, 1000 to 20000 Pa · s and is supplied onto the base film 11.

The ultraviolet absorber used in the present invention does not change even after the photocurable resin composition is cured to form a film, and remains as it is in the film. Then, the ultraviolet absorber blocks ultraviolet rays up to the longest wavelength region among the components of the raw material composition of the photocurable resin film produced by the present invention. That is, the ultraviolet transmission spectrum of the photocurable resin film produced by the present invention is the same as the ultraviolet transmission spectrum of the ultraviolet absorber. Therefore, in the present invention, the transmission intermediate wavelength λ _A of the ultraviolet absorber is determined from the ultraviolet transmission spectrum of the cured photocurable resin film according to the method described later.

FIG. 5 shows a photocurable resin containing an ultraviolet absorber obtained in Example 1 described later as an example for explaining a method for determining a _{transmission intermediate wavelength λ A} (nm) of an ultraviolet absorber in the present invention. It is a transmission spectrum (horizontal axis: wavelength, vertical axis: transmittance) measured in the range of 200 nm to 500 nm of the film. As shown in FIG. 5, the transmission intermediate wavelength in the present invention is a straight line (increasing portion auxiliary line 21) fitted to a portion where the transmittance increases, which is an extension line 22 and a length of the baseline on the short wavelength side. When the intersection with the extension line 23 of the baseline on the wavelength side is defined as the transmission start point 24 and the transmission end point 25, respectively, it means a wavelength intermediate between those wavelengths.

The ultraviolet absorber used in the present invention may have a transmission intermediate wavelength on the longer wavelength side than the transmission intermediate wavelength of the base film 11 and / or the cover film 13. The transmission intermediate wavelength of the ultraviolet absorber is preferably 350 nm or more, and more preferably 370 nm or more, in order to cut a wider range of ultraviolet light wavelength regions.

The ultraviolet absorber used in the present invention is not particularly limited as long as the transmitted intermediate wavelength is on the longer wavelength side than the transmitted intermediate wavelength of the base film 11 and / or the cover film 13, but is not particularly limited, and is, for example, a triazine type. From compounds, benzotriazole-based compounds, benzophenone-based compounds, cyanoacrylate-based compounds, benzoxazine-based compounds, and organic compound-based UV absorbers such as oxaziazole-based compounds, or fine particles of zinc oxide, titanium oxide, and cerium oxide. Inorganic UV absorbers can be mentioned. These can be used alone or in combination of two or more.

The type and content of the ultraviolet absorber used in the present invention are appropriately selected depending on the use of the film, the type of the photocurable resin composition, the thickness of the film, etc., but from the viewpoint of transparency and cost, the organic compound A UV absorber is preferable. Specifically, a triazine-based compound, a benzotrisol-based compound, a benzophenone-based compound and the like can be used alone or in combination of two or more. The content of the organic compound-based ultraviolet absorber is preferably 0.1 to 2.0 parts by weight with respect to the radical polymerization type photocurable resin. Examples of commercially available products include ADEKA STAB LA-24, ADEKA STAB LA-46, and ADEKA STAB 1413 (manufactured by ADEKA).

Further, the photocurable resin composition used in the present invention contains a photopolymerization initiator that initiates polymerization by irradiation with ultraviolet rays having a specific wavelength. The photopolymerization initiator used in the present invention generates radicals when irradiated with ultraviolet rays, and the radicals trigger a polymerization reaction. The photopolymerization initiator used in the present invention is a general-purpose photopolymerization initiator having a part of the ultraviolet absorption wavelength band that initiates polymerization on the longer wavelength side than the transmission intermediate wavelength of the ultraviolet absorber used. It is selected as appropriate.

Specifically, 2-hirodoxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 1-hydroxy-cyclohexyl-phenyl -Ketone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propane-1 -On, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one and the like can be selected from one alone or a combination of two or more. The content of the photopolymerization initiator is preferably 0.5 to 15 parts by weight with respect to the radical polymerization type photocurable resin. Commercially available products include Irgacure 127, 184, 369, 651, 500, 819, 907, 2959, 1173, TPO, MBF (above, manufactured by IGM Resins), OXE01, OXE02, OXE04 (above, manufactured by IBASF), etc. Can be mentioned.

Further, a sensitizer can be added to the photocurable resin composition used in the present invention in addition to the photopolymerization initiator. Specifically, anthracene, thioxanthone, benzophenone and the like can be selected alone or in combination of two or more. The content of the sensitizer is preferably 0.5 to 15 parts by weight with respect to the radical polymerization type photocurable resin. Examples of commercially available products include Anthracure UVS-581 and UVS-1331 (manufactured by Kawasaki Kasei Chemicals Co., Ltd.).

In the present invention, an appropriate solvent may be used as a diluent to adjust the viscosity of the photocurable resin composition. However, in that case, considering the process of removing the volatilization of the solvent, it takes time and the production efficiency is lowered, and the residual solvent and the like are present inside the photocurable resin film, which leads to the deterioration of the characteristics of the film. The content of the solvent contained in the mold resin composition is preferably kept at 5% or less, and it is preferable to use a solvent that does not substantially contain the solvent.

As the base film 11, a film such as polyester, polypropylene, polyethylene, polyvinyl fluoride, polycarbonate, polyamide, norbornene resin can be used. From the viewpoint of peelability and the like, the base film 11 may be provided with a treatment such as mold release or a coating layer on the surface. As the base film 11, a biaxially stretched polyester film having excellent heat resistance and transparency and having various other characteristics balanced is preferable.

_{The transmittance of ultraviolet rays of the base film 11 at the wavelength λ BL} of the emission peak of the light source on the base film side is preferably 80% or more, more preferably 85% or more. The thickness of the base film 11 is not particularly limited, but is preferably 10 to 400 μm, more preferably 50 to 300 μm. The surface shape may be flat, or the surface may be uneven. However, a surface shape that does not impair transparency is preferable. If the thickness of the base film 11 is less than 10 μm, the manufacturing method of the present invention may not be able to withstand the tension and may be damaged, and the deflection and distortion of the laminate generated in the manufacturing process may increase. high. Further, if the thickness of the base film 11 exceeds 400 μm, the transmittance is lowered, so that the integrated light amount of ultraviolet rays given to the photocurable resin composition is insufficient, and the curing of the photocurable resin composition may be insufficient. is there. The transmission intermediate wavelength λ _BF of the base film 11 is determined by the same method as the method for determining _{the transmission intermediate wavelength λ A} of the ultraviolet absorber described above.

The thickness of the photocurable resin composition layer on the base film 11 is not particularly limited, but if it is less than 0.01 mm, the base film 11 and / or the cover film 13 is likely to be peeled off or damaged in subsequent handling. There is a fear. Further, if the thickness of the photocurable resin composition layer is too thick, the amount of ultraviolet irradiation required for curing increases, making it difficult to handle the ultraviolet irradiation equipment, and the obtained photocurable resin film is rolled up. Since there is a possibility that the film may be damaged at times, 0.3 mm or less is preferable.

Examples of the photocurable resin composition coating device 12 include a die coater, a gravure coater, a roll coater, a reverse coater, a knife coater, a lip coater, a doctor coater, a wire bar coater, a curtain coater, and the like. A die coater is preferable from the viewpoint of supplying the resin composition with a uniform thickness.

In the present invention, the photocurable resin composition is cast on the base film 11 to a predetermined thickness, and then the cover film 13 is laminated on the photocurable resin composition layer before the irradiation with ultraviolet rays to form the laminate 14. can do. As the cover film 13 that can be used _{, it is preferable that the transmittance of ultraviolet light at the emission peak wavelength λ CL} of the light source on the cover film side is 80% or more, more preferably 85% or more, and the same as the base film 11. Can be used. The transmission intermediate wavelength λ _CF of the cover film 13 is determined by the same method as the method for determining _{the transmission intermediate wavelength λ A} of the ultraviolet absorber described above.

In the present invention, as shown in FIG. 3, after the photocurable resin composition is cast on the base film 11 to a predetermined thickness and then irradiated with ultraviolet rays, the cover film 13 is placed on the photocurable resin composition layer. It is also possible to form the laminated body 14 without laminating.

Further, in the present invention, as shown in FIG. 4, when the base film 11 and the cover film 13 are laminated with the pair of laminated rolls 18, the base film 11 and the cover film 13 are photocured from the fixed quantity supply head 123 between the base film 11 and the cover film 13. It is also possible to form the laminated body 14 by supplying a fixed amount of the mold resin composition. At this time, the thickness of the photocurable resin composition layer can be adjusted by adjusting the gap between the pair of laminated rolls 18.

By the above steps, the base film 11, the photocurable resin composition layer, and the laminated body 14 in which the cover film 13 is sequentially laminated if necessary are formed. Then, in the present invention, the photocurable resin composition layer is subsequently irradiated with ultraviolet rays from at least one surface of the laminate 14. At least one of the ultraviolet rays irradiated to the laminate is ultraviolet rays emitted from the ultraviolet light source 15 having an emission peak only in the ultraviolet absorption wavelength band of the photopolymerization initiator, and is contained in the photocurable resin composition layer. When the transmission intermediate wavelength of the ultraviolet absorber having the largest transmission intermediate wavelength value among the ultraviolet absorbers is λ _{A (nm), the wavelength λ BL} (nm) of the emission peak of the ultraviolet light source on the base film side and the cover film side. The emission peak wavelength of either the emission peak wavelength λ _CL (nm) of the ultraviolet light source or the emission peak wavelength λ _RL (nm) of the ultraviolet light source on the photocurable resin composition layer side is the transmission intermediate wavelength of the ultraviolet absorber. It is an ultraviolet ray on the longer wavelength side. _{Further, the wavelength λ BL} (nm) of the emission peak of the ultraviolet light source on the base film side, _{the wavelength λ CL} (nm) of the emission peak of the ultraviolet light source on the cover film side, and the emission peak of the ultraviolet light source on the photocurable resin composition layer side. It is preferable that the wavelength on the short wavelength side of the half-value width of the emission peak of any of the wavelengths λ _{RL (nm) of the above is also on the long wavelength side of the transmission intermediate wavelength of the ultraviolet absorber.}

As the ultraviolet rays in the present invention, ultraviolet rays having a wavelength of 100 nm to 410 nm can be used, but ultraviolet rays emitted from a light source having a single emission peak in the wavelength range of 380 nm to 410 nm are preferable, and LEDs are used. A light source using is preferred. Since the emission peak wavelength of the LED differs depending on the type of diode used, the optimum emission peak wavelength can be easily obtained. Further, in the present invention, two or more types of light sources can be used in combination, but it is preferable that the emission peak wavelengths of all the light sources are located on the longer wavelength side than the transmission intermediate wavelength of the ultraviolet absorber. In addition, metal halide lamps, high-pressure mercury lamps, low-pressure mercury lamps, pulse-type xenon lamps, xenon / mercury mixed lamps, low-pressure sterilization lamps, electrodeless lamps, etc., which have been conventionally used as ultraviolet light sources, also use wavelength filters. It can be shaped into an emission spectrum having a single emission peak in the wavelength range of 380 nm to 410 nm.

In the present invention, light other than the light emitted from the ultraviolet light source 15 can be irradiated together as long as the problem solving of the present invention is not affected.

The ultraviolet irradiation conditions in the present invention are not particularly limited because they differ depending on the thickness of the photocurable resin composition layer and the like, but for example, if irradiation ^{is performed so that the integrated light amount is 20 to 10,000 mJ / cm 2.} It is often, preferably 100 to 5000 mJ / cm ² .

It is preferable that the cooling device 16 is provided at the ultraviolet irradiation portion in the present invention. By cooling the laminate 14 with the cooling device 16 and controlling the temperature (T) at which the photocurable resin composition layer is cured by irradiation with ultraviolet rays, thermal deformation of the base film 11 and the like can be suppressed. Examples of the cooling method include known methods such as an air cooling method and a water cooling method. As shown in FIG. 3, after the photocurable resin composition is cast on the base film 11 to a predetermined thickness and then before the irradiation with ultraviolet rays, the cover film 13 is not laminated on the photocurable resin composition layer. In the case of the laminated body 14, if the cooling is performed from the photocurable resin composition layer side, the smoothness of the surface of the photocurable resin composition layer is impaired. Therefore, the cooling device 16 should be installed on the base film side. Is preferable.

In the present invention, the laminate 14 is irradiated with ultraviolet rays to cure the photocurable resin composition layer, and then the cover film 13 and / or the base film 11 is peeled from the laminate 14 to cure the photocurable resin film. 17 is obtained. Then, the photocurable resin film 17 can be wound into a roll by a known winding device. The peeled cover film 13 and / or the base film 14 may be wound in a roll shape by a known winding device. The photocurable resin film 17 is rolled in a state of being integrated with either the cover film 13 or the base film 14 without peeling off either the cover film 13 or the base film 14. It can also be wound up. Further, the cover film 13 or the base film 11 that is integrally wound with the photocurable resin film 17 in a roll shape is usually peeled off when the photocurable resin film 17 is used. By designing the material so that the adhesive strength with the cured resin film 17 is sufficient, it can be integrated with the photocurable resin film and used as a part of the photocurable resin film.

Hereinafter, an example of the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.
(Example 1)
A mixture of the following components was used as the photocurable resin composition A.
-Hexfunctional urethane acrylate oligomer (UN-3320HA manufactured by Negami Kogyo Co., Ltd.): 80 parts by weight-Trifunctional acrylic monomer (trimethylolpropane triacrylate) (TMP-A manufactured by Kyoeisha Chemical Co., Ltd.): 20 parts by weight-UV absorber (2) -[2-Hydroxy-5- (1,1,3,3-tetramethylbutyl) phenyl] benzotriazole) (ADEKA Adecaster LA-29): 0.5 part by weight, photopolymerization initiator (2,4) , 6-trimethylbenzoyl-diphenylphosphine oxide) (TGM Resins B.V. TPO): 2 parts by weight

Regarding the polyethylene terephthalate film used as the base film and the cover film, the transmission spectrum in the range of 200 nm to 500 nm was measured using an ultraviolet visible spectrophotometer (UV-2450, manufactured by Shimadzu Corporation), and described above. When the transmitted intermediate wavelength was determined by the same method as the method for determining the transmitted intermediate wavelength of the ultraviolet absorber, it was 316 nm. Further, with respect to the photocurable resin film obtained by curing the photocurable resin composition A, the ultraviolet absorber is measured by measuring the transmission spectrum in the range of 200 nm to 500 nm and determining the transmission intermediate wavelength of the ultraviolet absorber described above. When the transmission intermediate wavelength of was determined, it was 375 nm. The integrated light intensity was measured with an ultraviolet measuring device (UIT-θLED manufactured by Ushio, Inc.).

FIG. 6 shows the ultraviolet transmission spectrum of the ultraviolet absorber (corresponding to the ultraviolet transmission spectrum of the photocurable resin film 31), the ultraviolet absorption spectrum 32 of the photopolymerization initiator (TPO), and the emission spectrum 33 of the LED light source in Example 1. The relationship was shown. Table 1 shows the λ _CF value, the λ _A value, and the λ _CL value in Example 1. As is clear from FIG. 6 and Table 1, in Example 1, the ultraviolet light source has the only emission peak at 405 nm, the ultraviolet absorption wavelength band of the photopolymerization initiator exists at 405 nm, and λ _CF <λ. The relationship of _A <λ _{CL is satisfied.}

A photocurable resin composition A was cast on a base film made of a polyethylene terephthalate film having a thickness of 50 μm using a die coater as a coating device so as to have a thickness of 70 μm to form a photocurable resin composition layer. A cover film made of a polyethylene terephthalate film having a thickness of 50 μm was laminated on the surface of the photocurable resin composition layer to form a laminated body. Next, a photocurable resin film is irradiated with ultraviolet rays under the irradiation conditions shown in Table 1 using a light emitting diode light source (manufactured by Aitec System Co., Ltd.) having a single emission peak and having a peak wavelength λ _{CL of 405 nm.} Was produced.

(Example 2)
A photocurable resin film under the same conditions as in Example 1 except that the light source was changed to a light emitting diode light source (manufactured by Ushio, Inc.) having a peak wavelength λ _{CL of 395 nm and the irradiation conditions were changed to the irradiation conditions shown in Table 1.} Was produced.

(Example 3)
A photocurable resin film under the same conditions as in Example 1 except that the light source was changed to a light emitting diode light source (manufactured by Aitec System Co., Ltd.) having a peak wavelength λ _{CL of 385 nm and the irradiation conditions were changed to the irradiation conditions shown in Table 1.} Was produced.

(Comparative Example 1)
A photocurable resin film under the same conditions as in Example 1 except that the light source was changed from an LED to an electrodeless ultraviolet lamp (H valve manufactured by Heleus Co., Ltd.) and the irradiation conditions were changed to the irradiation conditions shown in Table 1. Was produced.

FIG. 7 shows the relationship between the ultraviolet transmission spectrum 31 of the ultraviolet absorber, the ultraviolet absorption spectrum 32 of the photopolymerization initiator, and the emission spectrum 34 of the electrodeless ultraviolet lamp (H valve manufactured by Heleus Co., Ltd.) in Comparative Example 1. .. The electrodeless ultraviolet lamp, which is the light source of Comparative Example 1, emits light at a wavelength longer than the transmission intermediate wavelength of the ultraviolet absorber and in the ultraviolet absorption wavelength band of the photopolymerization initiator, but also emits light widely at other wavelengths. doing. Therefore, there is no wavelength of the emission peak of the electrodeless ultraviolet lamp.

The reaction rate of the obtained photocurable resin film was determined by the following method. First, using an infrared imaging system (SpectrumSportlight300, manufactured by PerkinElmer Co., Ltd.), the IR spectra of the photocurable resin composition before ultraviolet irradiation and the prepared photocurable resin film were measured, and the CH surface of the vinyl group was measured. The height of the absorption peak ( ^{around 810 cm -1} ) of the external variation angle vibration was determined. Then, in both Comparative Examples and Examples, the height of the absorption peak of the photocurable resin composition before irradiation with ultraviolet rays is used as a reference value, and the difference from the reference value is used as the reference value for the height of the absorption peak in the photocurable resin film. The value obtained by dividing by and multiplying by 100 was calculated as the reaction rate (%) of each photocurable resin film. A state in which the reaction rate was 50% or more was determined to be a saturated cured state (denoted as ◯ in Table 1).

The peelability of the obtained photocurable resin film and polyethylene terephthalate film was evaluated according to the following criteria based on the situation when the film was peeled off by hand. ⊚: Can be peeled with almost no resistance, 〇: Can be peeled lightly, Δ: Can be peeled but has resistance, ×: Difficult to peel, XX: Cannot be peeled.

Table 1 shows the reaction rate and peelability of the obtained photocurable resin film. All Examples and Comparative Examples had reached a saturated cured state. Regarding the peelability, Examples 1 to 3 were in a state where they could be peeled off with almost no resistance or lightly peeled off, but Comparative Example 1 was in a state where they could not be peeled off due to fusion with the cover film and the base film. It is considered that this is because in Comparative Example 1, a large amount of light having a wavelength that does not necessarily contribute to secure the amount of light having a wavelength that contributes to the initiation of polymerization is also irradiated, resulting in an increase in the temperature of the laminate.

11 Base film 12 Coating head 122 Coating head 123 Fixed quantity supply head 13 Cover film 14 Laminated body 15 Ultraviolet light source 16 Cooling device 17 Photocurable resin film 18 Laminated roll 21 Rising part Auxiliary line 22 Extension of baseline on the short wavelength side Line 23 Extension of baseline on the long wavelength side 24 Transmission start point 25 Transmission end point 31 UV transmission spectrum (transmittance) of UV absorber
32 Ultraviolet absorption spectrum (absorbance) of photopolymerization initiator
33 LED light source emission spectrum (light intensity)
34 Emission spectrum (light intensity) of electrodeless ultraviolet lamp

Claims (7)

At least one layer of a photocurable resin composition composed of a liquid photocurable resin composition containing an ultraviolet absorber and a photopolymerization initiator is formed on one surface of the base film to form a laminate, and then the laminate is formed. The photocurable resin composition layer is cured by irradiating the photocurable resin composition layer with ultraviolet rays from at least one surface of the body, the base film side and the photocurable resin composition layer side. let a method for producing a photocurable resin film, at least one of the ultraviolet rays, the emission peak possess only UV absorption band of the photopolymerization initiator, the wavelength of single in the range of 380nm~410nm illuminated by the light source to have a light emission peak, the transmission medium wavelength lambda _{BF (nm)} of the base film, a transparent intermediate wavelength value of the transmission medium wavelength largest ultraviolet absorber of the ultraviolet absorber lambda _{a (nm} ), When the wavelength of the emission peak of the light source on the base film side is λ _BL (nm) and the wavelength of the emission peak of the light source on the photocurable resin composition layer side is λ _RL (nm), λ _BF <λ _A method for producing a photocurable resin film, characterized in that A <λ _BL and / or λ _A <λ _RL. At least one layer of a photocurable resin composition composed of a liquid photocurable resin composition containing an ultraviolet absorber and a photopolymerization initiator is formed between the base film and the cover film to form a laminate, and then the above-mentioned The photocurable resin composition layer is cured by irradiating the photocurable resin composition layer with ultraviolet rays from at least one surface of the laminate on the base film side and the cover film side. a method of manufacturing a mold resin film, perforated at least one of the ultraviolet rays, have a light emission peak only in the ultraviolet absorption band of the photopolymerization initiator, a wavelength of a single emission peak in the range of 380nm~410nm The transmission intermediate wavelength of the base film is λ _BF (nm), the transmission intermediate wavelength of the cover film is λ _CF (nm), and the ultraviolet absorption having the largest transmission intermediate wavelength value among the ultraviolet absorbers is irradiated by the light source. When the transmission intermediate wavelength of the agent is λ _A (nm), the wavelength of the emission peak of the light source on the base film side is λ _BL (nm), and the wavelength of the emission peak of the light source on the cover film side is λ _CL (nm). , Λ _BF <λ _A <λ _BL and / or λ _CF <λ _A <λ _CL , a method for producing a photocurable resin film. At least one layer of the photocurable resin composition layer is formed by casting a liquid photocurable resin composition containing an ultraviolet absorber and a photopolymerization initiator on the base film in the form of a film. The method for producing a photocurable resin film according to claim 2, wherein the cover film is formed by laminating the cover film on the photocurable resin composition layer. Before laminating the cover film on the photocurable resin composition layer, at least one layer of an ultraviolet absorber and photopolymerization are started on the surface of the cover film on the photocurable resin composition layer side in advance. The method for producing a photocurable resin film according to claim 3, wherein a layer made of a liquid photocurable resin composition containing an agent is formed. The method for producing a photocurable resin film according to any one of claims 2 to 4, wherein the base film and / or the cover film is a polyester film. The method for producing a photocurable resin film according to any one of claims 1 to 5, wherein the light source comprises a light emitting diode. The method for producing a photocurable resin film according to any one of claims 1 to 6, wherein the transmission intermediate wavelength λA of the ultraviolet absorber is 350 nm or more.

Images