JP6780738B2 - Laminated film and manufacturing method - Google Patents

Description

The present invention relates to a laminated film, and more particularly to a laminated film having excellent adhesiveness to a functional layer laminated on the film.

Although films are widely used due to their excellent properties, they have the drawback of poor adhesiveness depending on the application. For example, printing ink (printing ink for cellophane, chlorinated PP ink, UV curable ink, magnetic ink, etc.), heat-sensitive transfer ink, magnetic paint, adhesive (adhesive for lamination, adhesive for wood bonding, etc.), vapor deposition. Adhesion to metals / inorganic substances (aluminum, silver, gold, ITO, silicon oxide, aluminum oxide, etc.), mold release agents, ink receiving layers, gelatin, polyvinyl alcohol, polyvinyl acetal, cellulose acetate, cellulose butyrate, methyl cellulose, carboxymethyl cellulose, etc. Inferior in sex.

Methods for improving the adhesiveness of the film include a method of treating the film with a solvent, a corona discharge treatment, a plasma treatment, and the like (Patent Documents 1 and 2), but these methods are various methods of being laminated on the film. The effect of improving the adhesiveness with the functional layer is insufficient, and a method of laminating an adhesive coating layer on the film by a coating treatment has been proposed, but still in the type of the functional layer provided on the coating layer. In some cases, the adhesiveness was insufficient (Patent Document 3).

Japanese Unexamined Patent Publication No. 3-56541 Japanese Unexamined Patent Publication No. 11-129378 Japanese Unexamined Patent Publication No. 2004-001486

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminated film having excellent adhesiveness to a functional layer laminated on the film.

As a result of diligent studies in view of the above circumstances, the present inventors have found that the above-mentioned problems can be easily solved by using a laminated film having a specific configuration, and have completed the present invention.

That is, the gist of the present invention is a laminated film having a coating layer and a functional layer on at least one side of the film in this order, and the functional layer is an active energy ray-cured film containing a compound having a carbon-carbon double bond. It is a layer formed from a sex composition, and the coating layer is a composite composed of a resin containing a (meth) acryloyl group having reactivity with the compound having a carbon-carbon double bond and a urethane resin. It is a layer formed from a coating liquid containing a resin, and exists in a laminated film characterized in that the composite resin is in the range of 45 to 80% by weight as a ratio to all non-volatile components in the coating liquid.

According to the laminated film of the present invention, for example, it is possible to provide a laminated film having excellent adhesiveness to various functional layers such as an ink layer containing an active energy ray-curable compound or the like, and its industrial use. The value is high.

As the film base material of the laminated film in the present invention, conventionally known ones can be used, for example, polyester film, polycarbonate film, fluororesin film, polyimide film, triacetyl cellulose film, polyolefin film, polyacrylate film, and the like. Examples thereof include polystyrene film, polyvinyl chloride film, polyvinyl alcohol film, ethylene vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, nylon film and the like. In particular, it is preferable to have heat resistance in order to develop it into various applications, and polyester film, polycarbonate film, fluororesin film, and polyimide film are preferably used, and polyester is further considered in terms of transparency, moldability, and versatility. Films are more preferably used.

The film constituting the laminated film in the present invention may have a single-layer structure or a multi-layer structure, and has four or more layers as long as the gist of the present invention is not exceeded in addition to the two-layer and three-layer structure. It may be, and is not particularly limited.

As the polyester film used as the film of the present invention, the polyester used may be a homopolyester or a copolymerized polyester. When it is made of homopolyester, it is preferably obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol and 1,4-cyclohexanedimethanol. Examples of typical polyesters include polyethylene terephthalate and the like. On the other hand, examples of the dicarboxylic acid component of the copolymerized polyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (for example, p-oxybenzoic acid). One or more of them may be mentioned, and examples of the glycol component include one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 4-cyclohexanedimethanol, neopentyl glycol and the like.

The polyester polymerization catalyst is not particularly limited, and conventionally known compounds can be used. Examples thereof include antimony compounds, titanium compounds, germanium compounds, manganese compounds, aluminum compounds, magnesium compounds and calcium compounds. Among these, titanium compounds and germanium compounds are preferable because they have high catalytic activity, can be polymerized in a small amount, and the amount of metal remaining in the film is small, so that the brightness of the film is high. Further, since the germanium compound is expensive, it is more preferable to use a titanium compound.

In the case of polyester using a titanium compound, the titanium element content is preferably in the range of 50 ppm or less, more preferably 1 to 20 ppm, and further preferably 2 to 10 ppm. If the content of the titanium compound is too high, the deterioration of the polyester may be accelerated in the process of melt extrusion of the polyester, resulting in a film with a strong yellow tint. If the content is too low, the polymerization efficiency is poor and the cost is high. It may not be possible to obtain a film that is up or has sufficient strength. When a polyester made of a titanium compound is used, it is preferable to use a phosphorus compound in order to reduce the activity of the titanium compound for the purpose of suppressing deterioration in the melt extrusion process. As the phosphorus compound, orthophosphoric acid is preferable in consideration of polyester productivity and thermal stability. The phosphorus element content is preferably in the range of 1 to 300 ppm, more preferably 3 to 200 ppm, still more preferably 5 to 100 ppm with respect to the amount of polyester to be melt-extruded. If the content of the phosphorus compound is too high, it may cause gelation or foreign matter, and if the content is too low, the activity of the titanium compound cannot be sufficiently reduced, resulting in a yellowish color. It may be a film.

As the polycarbonate film that can be used as the laminated film of the present invention, conventionally known polycarbonate can be used, but a type containing a bisphenol A structure is particularly preferable.

As the fluororesin film that can be used as the laminated film of the present invention, conventionally known fluororesins can be used. For example, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, etc. Examples thereof include a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer.

It is also possible to include an ultraviolet absorber in the film of the present invention in order to improve the weather resistance of the film and prevent deterioration of the liquid crystal and the like. The ultraviolet absorber is a compound that absorbs ultraviolet rays and is not particularly limited as long as it can withstand the heat applied in the film manufacturing process.

Examples of the ultraviolet absorber include an organic ultraviolet absorber and an inorganic ultraviolet absorber, but an organic ultraviolet absorber is preferable from the viewpoint of transparency. The organic ultraviolet absorber is not particularly limited, and examples thereof include cyclic iminoesters, benzotriazoles, and benzophenones. From the viewpoint of durability, cyclic iminoester type and benzotriazole type are more preferable. It is also possible to use two or more types of ultraviolet absorbers in combination.

Particles can also be blended into the film of the present invention mainly for the purpose of imparting slipperiness and preventing scratches in each step. The type of particles to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness, and specific examples thereof include silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, and phosphoric acid. Examples thereof include inorganic particles such as magnesium, kaolin, aluminum oxide and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin and benzoguanamine resin. Further, during the film manufacturing process, precipitated particles in which a part of a metal compound such as a catalyst is precipitated and finely dispersed can also be used.

The shape of the particles to be used is not particularly limited, and any of spherical, lumpy, rod-shaped, flat-shaped and the like may be used. Further, the hardness, specific gravity, color and the like are not particularly limited.
Two or more kinds of these series of particles may be used in combination, if necessary.

The average particle size of the particles is preferably in the range of 5 μm or less, more preferably 0.01 to 3 μm. By using the average particle size in the above range, the film is given an appropriate surface roughness, and problems are less likely to occur when various functional layers and the like are formed in the subsequent process.

Further, the particle content in the film is preferably in the range of less than 5% by weight, more preferably 0.0003 to 3% by weight. If there are no or few particles, the transparency of the film will be high and the film will be good, but the slipperiness may be insufficient. Therefore, by putting particles in the coating layer, the slipperiness can be improved. It may be necessary to take measures such as improving it. Further, when the particle content is too large, the haze may not be sufficiently lowered even if the functional layer is formed, and the transparency of the film may be insufficient.

The method of adding the particles to the film is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at any stage in the production of the film constituting each layer, but it is preferably added after the esterification or transesterification reaction is completed.

In addition to the above-mentioned particles, conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments and the like can be added to the film of the present invention, if necessary.

The thickness of the film in the present invention is not particularly limited as long as it can be formed as a film, but is usually in the range of 10 to 350 μm, more preferably 20 to 300 μm.

Next, a production example of the film in the present invention will be specifically described, but the present invention is not limited to the following production examples. Generally, the resin is melted, made into a sheet, and stretched for the purpose of increasing the strength to prepare a film. As an example, the case of manufacturing the polyester film described above will be introduced. A method of obtaining an unstretched film by cooling and solidifying the molten film extruded from the die with a cooling roll using pellets obtained by drying the polyester raw material is preferable. In this case, in order to improve the flatness of the film, it is preferable to improve the adhesiveness between the film and the rotary cooling drum, and the electrostatic application adhesion method and the liquid application adhesion method are preferably adopted. Next, the obtained unstretched film is stretched in the biaxial direction. In that case, first, the unstretched film is stretched in one direction by a roll or tenter type stretching machine. The stretching temperature is usually 70 to 120 ° C., preferably 80 to 110 ° C., and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Then, it is stretched in a direction orthogonal to the stretching direction of the first stage, in which case the stretching temperature is usually 70 to 170 ° C. and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. is there. Then, the heat treatment is subsequently performed at a temperature of 180 to 250 ° C. under tension or relaxation within 30% to obtain a biaxially oriented film. In the above stretching, a method of stretching in one direction in two or more steps can also be adopted. In that case, it is preferable to finally set the stretching ratios in the two directions within the above ranges.

Further, in the present invention, the simultaneous biaxial stretching method can also be adopted for producing the film constituting the laminated film. The simultaneous biaxial stretching method is a method of simultaneously stretching and orienting the unstretched sheet in the mechanical direction and the width direction in a state where the temperature is controlled at usually 70 to 120 ° C., preferably 80 to 110 ° C. The area magnification is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times. Then, the heat treatment is subsequently performed at a temperature of 170 to 250 ° C. under tension or relaxation within 30% to obtain a stretch-oriented film. As for the simultaneous biaxial stretching device that employs the above-mentioned stretching method, conventionally known stretching methods such as a screw method, a pantograph method, and a linear drive method can be adopted.

Next, the formation of the coating layer constituting the laminated film in the present invention will be described. Regarding the coating layer, the film surface may be treated during the film forming process, which may be provided by in-line coating, or an offline coating, which is once produced and applied outside the system, may be adopted. More preferably, it is formed by in-line coating.

The in-line coating is a method of coating in a film manufacturing process, and specifically, a method of coating at an arbitrary stage from melt extrusion of a resin to stretching, heat fixing, and winding. Usually, it is coated on any of an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat fixing, and a film after heat fixing and before winding. Although not limited to the following, for example, in sequential biaxial stretching, a method of coating a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) and then stretching in the lateral direction is particularly excellent. According to such a method, since the film formation and the coating layer formation can be performed at the same time, there is an advantage in manufacturing cost, and the thickness of the coating layer can be changed by the stretching ratio in order to perform stretching after coating. , Thin film coating can be performed more easily than offline coating. Further, by providing the coating layer on the film before stretching, the coating layer can be stretched together with the base film, whereby the coating layer can be firmly adhered to the base film. Further, in the production of a biaxially stretched film, the film can be restrained in the vertical and horizontal directions by stretching while gripping the end of the film with a clip or the like, and in the heat fixing step, the film is flat without wrinkles or the like. It is possible to apply high temperature while maintaining. Therefore, since the heat treatment applied after coating can be set to a high temperature that cannot be achieved by other methods, the film-forming property of the coating layer can be improved, and the coating layer and the base film can be more firmly adhered to each other. Furthermore, a strong coating layer can be formed, and performance such as adhesiveness to various functional layers that can be formed on the coating layer and moisture heat resistance can be improved.

In the present invention, it is an essential requirement that at least one side of the film has a coating layer formed of a coating liquid containing a resin containing a (meth) acryloyl group and a composite resin composed of a urethane resin. ..

The coating layer in the present invention has a composition of usually solvent-free active energy ray-curable, such as various functional layers, particularly a curable resin layer by active energy rays, and in particular, an active energy ray-curable ink layer. It is most suitable for improving the adhesiveness with a curable resin layer formed from an object, which is generally difficult to secure adhesiveness.

By using a composite resin made of a resin containing a (meth) acryloyl group and a urethane resin, a higher degree of adhesiveness could be exhibited. The speculation mechanism for the development of advanced adhesion is the carbon-carbon double bond due to the (meth) acryloyl group present in the coating layer and the carbon-carbon double bond in the compound used for formation as a functional layer on the coating layer. It reacts with a bond to form a covalent bond. By using not only the resin containing the (meth) acryloyl group but also the composite resin with the urethane resin, not only the adhesiveness with the functional layer is improved, but also the adhesiveness with the film as the base material is improved. It is presumed that the adhesiveness of the film as a whole can be improved.

The resin containing a (meth) acryloyl group is not particularly limited as long as it is a resin containing a (meth) acryloyl group, and examples thereof include conventionally known resins such as epoxy resin, polyester resin, and acrylic resin. Of these, epoxy resins are preferable from the viewpoint of being easy to synthesize and being able to introduce many (meth) acryloyl groups. Among the epoxy resins, aromatic-containing epoxy resins are preferable from the viewpoint of excellent durability such as water resistance and solvent resistance, and among them, novolak type epoxy resins and bisphenol type epoxy resins are more preferable, (meth). From the viewpoint of introducing an acryloyl group, a novolak type epoxy resin is more preferable.

Examples of the novolak type epoxy resin include cresol novolac type and phenol novolac type, and examples of the bisphenol type epoxy resin include bisphenol A type, bisphenol F type and bisphenol S type. Among these, the cresol novolac type epoxy resin and the bisphenol A type epoxy resin are more preferable in consideration of versatility and flexibility of the resin. Further, the epoxy resin may be used alone or in combination of two or more.

A conventionally known urethane resin can be used as the resin containing the (meth) acryloyl group and the urethane resin for forming the composite resin. Urethane resins are usually made by the reaction of polyol and isocyanate. Examples of the polyol include polyester polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, and acrylic polyols, and these compounds may be used alone or in a plurality of types. Among the above, polyester polyols are more preferable in consideration of adhesiveness to the polyester film base material. Further, in consideration of water resistance, polycarbonate polyols are more preferable among the above.

Polypolypolyols include polyvalent carboxylic acids (terephthalic acid, isophthalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimeric acid, suberic acid, sebacic acid, fumaric acid, maleic acid, etc.) or their acid anhydrides. Products and polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-Methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol , 2-Methyl-2-propyl-1,3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2 , 5-Diol-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2 -Hexyl-1,3-propanediol, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyldialkanolamine, lactonediol, etc.) can be mentioned.

Among these, from the viewpoint of durability such as water resistance and solvent resistance, the polyvalent carboxylic acid is preferably an aromatic carboxylic acid, and above all, considering the coating appearance and the adhesiveness to the film substrate, Terephthalic acid and isophthalic acid are more preferable. Further, in particular, considering the coating appearance and applicability to in-line coating, those having a certain degree of flexibility are preferable, and it is optimal to use terephthalic acid and isophthalic acid in combination.

The molar ratio of terephthalic acid: isophthalic acid to be used in combination is preferably 1 to 10: 1 to 10, more preferably 1 to 5: 1 to 5, and even more preferably 1 to 3: 1 to 3. The range is preferably 1 to 2: 1 to 2.

Further, as the polyhydric alcohol, those having a short molecular chain such as ethylene glycol, diethylene glycol and propylene glycol are preferable in order to increase the aromatic ratio of the carboxylic acid component, and further, considering the flexibility of the resin, diethylene glycol is contained. Is preferable. It is more preferable to use ethylene glycol and diethylene glycol in combination in consideration of durability, coating appearance, and flexibility. The molar ratio of ethylene glycol: diethylene glycol to be used in combination is preferably 1 to 10: 1 to 10, more preferably 1 to 5: 1 to 5, still more preferably 1 to 3: 1 to 3, particularly preferably. Is in the range of 1-2: 1-2.

Polycarbonate polyols are obtained from polyhydric alcohols and carbonate compounds by a dealcohol reaction. Examples of polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentane. Diol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decane Examples thereof include diol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 3,3-dimethylol heptane. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate and the like, and examples of the polycarbonate-based polyols obtained from these reactions include poly (1,6-hexylene) carbonate and poly (3-). Methyl-1,5-pentylene) carbonate and the like can be mentioned.

Examples of the polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol and the like.

Examples of the polyisocyanate compound used to obtain a urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylenedi isocyanate, naphthalene diisocyanate, and trizine diisocyanate, α, α, α', and α'. − Arophilic diisocyanates such as tetramethylxylylene diisocyanate, methylene diisocyanates, propylene diisocyanates, lysine diisocyanates, trimethylhexamethylene diisocyanates, aliphatic diisocyanates such as hexamethylene diisocyanates, cyclohexane diisocyanates, methylcyclohexane diisocyanates, isophorone diisocyanates, dicyclohexyl Examples thereof include alicyclic diisocyanates such as methane diisocyanate and isopropyridene dicyclohexyl diisocyanate. These may be used alone or in combination of two or more. Among these, in consideration of yellowing, it is preferable that it is not an aromatic isocyanate.

A chain extender may be used when synthesizing the urethane resin, and the chain extender is not particularly limited as long as it has two or more active groups that react with the isocyanate group, and is generally a hydroxyl group. Alternatively, a chain extender having two amino groups can be mainly used.

Examples of the chain extender having two hydroxyl groups include aliphatic glycols such as ethylene glycol, propylene glycol and butanediol, aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene, and esters such as neopentyl glycol hydroxypivalate. Examples of glycols such as glycols can be mentioned. Examples of the chain extender having two amino groups include aromatic diamines such as tolylene diamine, xylylene diamine, and diphenylmethanediamine, ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3-. Propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10- Aliphatic diamines such as decanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropylidenecyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1, Examples thereof include alicyclic diamines such as 3-bisaminomethylcyclohexane.

The urethane resin in the present invention may use a solvent as a medium, but is preferably water as a medium. To disperse or dissolve the urethane resin in water, there are a forced emulsification type using an emulsifier, a self-emulsification type in which a hydrophilic group is introduced into the urethane resin, a water-soluble type, and the like. In particular, the self-emulsifying type in which an ionic group is introduced into the structure of the urethane resin to form an ionomer is preferable because it is excellent in storage stability of the liquid and the water resistance, transparency and adhesiveness of the obtained coating layer.

Examples of the ionic group to be introduced include various types such as a carboxyl group, a sulfonic acid, a phosphoric acid, a phosphonic acid, and a quaternary ammonium salt, and a carboxyl group is preferable. As a method for introducing a carboxyl group into the urethane resin, various methods can be taken in each stage of the polymerization reaction. For example, at the time of prepolymer synthesis, there are a method of using a resin having a carboxyl group as a copolymerization component and a method of using a component having a carboxyl group as one component of a polyol, a polyisocyanate, a chain extender and the like. In particular, a method of using a carboxyl group-containing diol and introducing a desired amount of carboxyl groups according to the amount of this component charged is preferable.

For example, copolymerizing dimethylolpropionic acid, dimethylolbutanoic acid, bis- (2-hydroxyethyl) propionic acid, bis- (2-hydroxyethyl) butanoic acid, etc. with the diol used for polymerizing the urethane resin. Can be done. Further, this carboxyl group is preferably in the form of a salt neutralized with ammonia, amines, alkali metals, inorganic alkalis and the like. Particularly preferred are ammonia, trimethylamine and triethylamine.
In such a polyurethane resin, the carboxyl group from which the neutralizing agent has been removed in the drying step after coating can be used as a cross-linking reaction point by another cross-linking agent. As a result, the stability of the liquid before coating is excellent, and the durability, solvent resistance, water resistance, blocking resistance, etc. of the obtained coating layer can be further improved.

Regarding the formation of a composite resin of a resin containing a (meth) acryloyl group and a urethane resin, for example, it can be produced by mixing and stirring a resin containing a (meth) acryloyl group and a urethane resin in a solvent such as water. is there. More specifically, for example, in the case of a type in which a polyurethane resin contains a hydrophilic group, the resin containing the (meth) acryloyl group alone or the resin containing the (meth) acryloyl group in a state where the urethane resin is dispersed or dissolved in an aqueous medium, or It can be synthesized by mixing a resin containing a (meth) acryloyl group dispersed or dissolved in a solvent and stirring the mixture. If the resin containing the (meth) acryloyl group has no or few hydrophilic groups, it becomes hydrophobic, and it is preferable to mix it with a dispersion or a solution of the urethane resin in a state of being dispersed or dissolved using an organic solvent. In that case, for example, by removing the organic solvent in which the resin containing the (meth) acryloyl group was dispersed or dissolved by reducing the pressure, the resin containing the hydrophobic (meth) acryloyl group is the core. It is possible to obtain a composite resin emulsion having a core-shell structure in which a hydrophilic urethane resin serves as a shell. The core-shell structure is more preferable because it stabilizes the liquid and can be stably present even when mixed with other components, and can be widely used. Further, according to the method of the above example, since the core and the shell are not bonded, the core and the shell can move freely separately when the emulsion is broken by removing the solvent by drying after application. The (meth) acryloyl group in the portion can also come out on the surface of the coating layer, which can be advantageous for improving the adhesiveness with various functional layers that can be formed on the coating layer.

The ratio of the (meth) acryloyl group contained in the resin composed of the resin containing the (meth) acryloyl group and the composite resin composed of the urethane resin is usually 1 to 50% by weight, preferably 3 to 30% by weight, as the ratio of the entire composite resin. It is more preferably in the range of 5 to 25% by weight, still more preferably in the range of 8 to 20% by weight. By using it in the above range, the adhesiveness with various functional layers formed on the coating layer can be improved.

The ratio of the (meth) acryloyl group-containing resin to the urethane resin in the composite resin is the weight ratio of the meta) acryloyl group-containing resin: urethane resin, which is usually 1 to 5: 1 to 5, preferably 1 to 3. : 1-3, more preferably 1-2: 1-2. By using it in the above range, the adhesiveness with various functional layers formed on the coating layer and the adhesiveness with the polyester film as a base material can be improved. Further, if a core-shell structure is formed as the composite resin, it is preferable to use it in the above range in terms of synthesis.

For the formation of the coating layer in the film of the present invention, various polymers can be used in combination in order to improve the coating appearance, transparency and adhesiveness.

Specific examples of the polymer include urethane resin, polyester resin, acrylic resin, polyvinyl (polyvinyl alcohol, polyvinyl chloride, vinyl chloride copolymer, etc.), polyalkylene glycol, polyalkyleneimine, methyl cellulose, hydroxycellulose, and starches. And so on.

Further, in forming the coating layer in the film of the present invention, a cross-linking agent is used in combination with the coating film of the coating layer in order to strengthen the coating film and improve sufficient adhesiveness and moist heat resistance with the active energy ray-curable ink layer and the like. Is preferable.

Specific examples of the cross-linking agent include oxazoline compounds, epoxy compounds, carbodiimide-based compounds, isocyanate-based compounds, melamine compounds, silane coupling compounds, hydrazide compounds, aziridine compounds and the like. Among the above, oxazoline compounds, epoxy compounds, carbodiimide-based compounds and isocyanate-based compounds are preferable from the viewpoint of improving adhesiveness.

The oxazoline compound is a compound having an oxazoline group in the molecule, and a polymer containing an oxazoline group is particularly preferable, and it can be prepared by polymerization of an addition-polymerizable oxazoline group-containing monomer alone or with another monomer. Additive polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, Examples thereof include 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and one or a mixture of two or more thereof can be used.

Of these, 2-isopropenyl-2-oxazoline is industrially readily available and suitable. The other monomer is not limited as long as it is a monomer copolymerizable with an addition-polymerizable oxazoline group-containing monomer, and is, for example, an alkyl (meth) acrylate (as an alkyl group, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, etc. (Meta) acrylic acid esters such as n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene Unsaturated carboxylic acids such as sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; (meth) acrylamide, N-alkyl ( Meta) acrylamide, N, N-dialkyl (meth) acrylamide, (alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl Unsaturated amides such as group, cyclohexyl group, etc .; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; Vinyl chloride, vinylidene chloride , Halogen-containing α, β-unsaturated monomers such as vinyl fluoride; α, β-unsaturated aromatic monomers such as styrene, α-methylstyrene, etc., and one or more of these. Monomer can be used.

The content of the oxazoline group contained in the oxazoline compound is usually 0.5 to 10 mmol / g, preferably 1 to 9 mmol / g, more preferably 3 to 8 mmol / g, and further preferably 4 to 6 mmol in terms of the amount of the oxazoline group. It is in the range of / g. Use within the above range is preferable because the adhesiveness to various functional layers is improved.

The epoxy compound is a compound having an epoxy group in the molecule, and examples thereof include a condensate of epichlorohydrin and an ethylene glycol, polyethylene glycol, glycerin, polyglycerin, bisphenol A, or the like with a hydroxyl group or an amino group. There are polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds and the like. Examples of the polyepoxy compound include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyltris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, and trimethylolpropane. Examples of the polyglycidyl ether and the diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether. , Polypropylene glycol diglycidyl ether, Polytetramethylene glycol diglycidyl ether, Monoepoxy compounds include, for example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenylglycidyl ether, glycidylamine compounds N, N, N', N ′ -Tetraglycidyl-m-xylylene diamine, 1,3-bis (N, N-diglycidylamino) cyclohexane and the like can be mentioned.

A carbodiimide-based compound is a compound having a carbodiimide structure, which is a compound having one or more carbodiimide structures in the molecule, but polycarbodiimide having two or more in the molecule for better adhesion or the like. System compounds are more preferable.

The carbodiimide-based compound can be synthesized by a conventionally known technique, and a condensation reaction of a diisocyanate compound is generally used. The diisocyanate compound is not particularly limited, and any aromatic type or aliphatic type can be used. Specifically, tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylenediisocyanate, naphthalenediisocyanate, hexa Examples thereof include methylene diisocyanis, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyldiisocyanis, and dicyclohexylmethane diisocyanate.

Further, in order to improve the water solubility and water dispersibility of the polycarbodiimide compound within the range where the effect of the present invention is not lost, a surfactant may be added, or a polyalkylene oxide or a quaternary ammonium salt of a dialkylamino alcohol may be added. Hydrophilic monomers such as hydroxyalkyl sulfonate may be added and used.

The isocyanate-based compound is a compound having an isocyanate derivative structure typified by isocyanate or blocked isocyanate. Examples of the isocyanate include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylenedi isocyanate and naphthalene diisocyanate, and aromatic rings such as α, α, α'and α'-tetramethylxylylene diisocyanate. Aliphatic isocyanates such as aliphatic isocyanates, methylene diisocyanates, propylene diisocyanates, lysine diisocyanates, trimethylhexamethylene diisocyanates, hexamethylene diisocyanates, cyclohexane diisocyanates, methylcyclohexane diisocyanates, isophorone diisocyanates, methylenebis (4-cyclohexylisocyanates), isopropyridene dicyclohexyldiisocyanates and the like. The alicyclic isocyanate of the above is exemplified.

In addition, polymers and derivatives such as burettes, isocyanurates, uretdiones, and carbodiimides of these isocyanates can also be mentioned. These may be used alone or in combination of two or more. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferable than aromatic isocyanates in order to avoid yellowing due to ultraviolet rays.

When used in the state of blocked isocyanate, the blocking agent includes, for example, phenolic compounds such as heavy sulfites, phenol, cresol and ethylphenol, and alcoholic compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol and ethanol. Compounds, active methylene compounds such as dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone, mercaptan compounds such as butyl mercaptan and dodecyl mercaptan, lactam compounds such as ε-caprolactam and δ-valerolactam. , Amine compounds such as diphenylaniline, aniline, ethyleneimine, acid amide compounds of acetanilide and acetate amide, oxime compounds such as formaldehyde, acetoaldoxime, acetone oxime, methyl ethyl ketone oxime, cyclohexanone oxime, and these alone Two or more kinds may be used in combination.

Further, the isocyanate-based compound in the present invention may be used alone, or may be used as a mixture or a bond with various polymers. In terms of improving the dispersibility and crosslinkability of the isocyanate compound, it is preferable to use a mixture or a bond with a polyester resin or a urethane resin.

A melamine compound is a compound having a melamine skeleton in the compound, for example, an alkylolated melamine derivative, a compound obtained by reacting an alkylolated melamine derivative with an alcohol to partially or completely etherify, and these. A mixture can be used. As the alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. Further, the melamine compound may be either a monomer or a multimer of a dimer or more, or a mixture thereof may be used. Further, a melamine that is copolymerized with urea or the like can be used, or a catalyst can be used to increase the reactivity of the melamine compound.

These cross-linking agents are used in a design to improve the performance of the coating layer by reacting them in the drying process and the film forming process. It can be inferred that unreacted products of these cross-linking agents, compounds after the reaction, or mixtures thereof are present in the completed coating layer.

Further, in order to improve slipperiness and blocking, it is preferable to use particles in combination for forming the coating layer. The average particle size of the particles is preferably in the range of 0.001 μm to 1.0 μm, more preferably 0.005 μm to 0.5 μm, and even more preferably 0.01 μm to 0.2 μm from the viewpoint of film transparency.

Examples of the particles to be used include inorganic particles such as silica, alumina and metal oxide, and organic particles such as crosslinked polymer particles. In particular, silica particles are preferable from the viewpoint of dispersibility in the coating layer and transparency of the obtained coating film.

Further, as long as the gist of the present invention is not impaired, a defoaming agent, a coating property improving agent, a thickener, an organic lubricant, an antistatic agent, an ultraviolet absorber, and an antioxidant are necessary for forming the coating layer. , Foaming agents, dyes, pigments and the like may be used in combination.

As a ratio to all non-volatile components in the coating liquid forming the coating layer in the film of the present invention, the composite resin composed of the resin containing the (meth) acryloyl group and the urethane resin is usually 5% by weight or more, preferably 35% by weight or more. As described above, it is more preferably in the range of 45 to 99% by weight. If it is out of the above range, the adhesiveness may not be sufficient depending on the functional layer provided on the coating layer.

In the laminated film of the present invention, it is also possible to provide a coating layer on a surface opposite to the surface on which the coating layer is provided as described above. The surface on the opposite side can be a coating layer according to the application, and conventionally known components can be used as the constituent components. Examples thereof include polymers such as urethane resin, polyester resin and acrylic resin, cross-linking agents such as oxazoline compounds, epoxy compounds, carbodiimide compounds, isocyanate compounds and melamine compounds, and these materials may be used alone. , A plurality of types may be used in combination. Further, it may be a coating layer (the same coating layer on both sides of the film) formed from a coating liquid containing a composite resin composed of a resin containing a (meth) acryloyl group and a urethane resin as described above.

The analysis of the components in the coating layer can be performed by, for example, analysis of TOF-SIMS, ESCA, fluorescent X-rays and the like.

When the coating layer is provided by in-line coating, the above series of compounds are used as an aqueous solution or an aqueous dispersion, and a coating liquid having a solid content concentration of about 0.1 to 50% by weight is applied onto the film. It is preferable to produce a laminated film. Further, a small amount of an organic solvent may be contained in the coating liquid for the purpose of improving dispersibility in water, improving film forming property, etc., as long as the gist of the present invention is not impaired. Only one kind of organic solvent may be used, and two or more kinds may be used as appropriate.

With respect to the laminated film in the present invention, the thickness of the coating layer provided on the film is preferably 0.002 to 1.0 μm, more preferably 0.005 to 0.5 μm, still more preferably 0.005 to 0.3 μm. , Particularly preferably in the range of 0.01 to 0.2 μm. If the film thickness is out of the above range, the adhesiveness, coating appearance, and blocking characteristics may deteriorate.

In the film of the present invention, a conventionally known coating method such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, curtain coating and the like can be used as the method for providing the coating layer.

In the present invention, the drying and curing conditions for forming the coating layer on the film are not particularly limited. For example, when the coating layer is provided by offline coating, it is usually at 80 to 200 ° C. for 3 to 40 seconds. It is preferable to perform the heat treatment at 100 to 180 ° C. for 3 to 40 seconds as a guide.

On the other hand, when the coating layer is provided by in-line coating, it is usually preferable to perform heat treatment at 70 to 280 ° C. for 3 to 200 seconds as a guide.

Further, regardless of the offline coating or the in-line coating, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used in combination as needed. The film constituting the laminated film in the present invention may be subjected to surface treatment such as corona treatment and plasma treatment in advance.

It is common to provide various functional layers on the coating layer of the laminated film of the present invention, and among the functional layers, it is difficult to secure an active energy curable resin layer and further adhesiveness. It is a solvent-free (usually 5% by weight or less, preferably 3% by weight or less, more preferably 1% by weight or less, more preferably solvent-free) functional layer, and is particularly characterized in that an ink layer can be provided. Yes, the film of the present invention is suitable in such a field.

Other components in the functional layer are not particularly limited. Examples thereof include inorganic or organic fine particles, polymerization initiators, polymerization inhibitors, antioxidants, antistatic agents, dispersants, surfactants, light stabilizers and leveling agents. Further, in the case of drying after forming a film in the wet coating method, an arbitrary amount of solvent can be added.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded. The measurement method and evaluation method used in the present invention are as follows.

(1) Method for measuring the ultimate viscosity of polyester 1 g of polyester from which other polymer components and pigments incompatible with polyester have been removed is precisely weighed, and 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (weight ratio) is added. And dissolved, and measured at 30 ° C.

(2) Measurement method of average particle size The coating layer was observed using TEM (H-7650 manufactured by Hitachi High-Technologies Corporation, accelerating voltage 100V), and the average value of the particle size of 10 particles was taken as the average particle size. ..

(3) after decompressing the content composite resin (meth) acryloyl groups in the composite resin drying, using NMR (Bruker Biospin Co. ^{AVANCEIII600),} belong to the peaks of the ¹ H and ¹³ C, it was calculated ..

(4) Method for Measuring Film Thickness of Coating Layer The surface of the coating layer was dyed with RuO ₄ and embedded in an epoxy resin. Then, the section prepared by the ultrathin section method is dyed with RuO ₄ , the cross section of the coating layer is measured using TEM (Hitachi High-Technologies Corporation H-7650, accelerating voltage 100V), and the average value of 10 points is applied. The film thickness of the layer was used.

(5) Adhesiveness evaluation method FD Carton ACE Airo (offset printing ink manufactured by Toyo Ink Co., Ltd.), which is an active energy ray-curable ink, is printed on the film surface with an RI tester, which is an offset printing device. A film having an ink layer with a thickness of 3 μm formed by irradiating the resin with ultraviolet rays under the effect conditions of a metal halide lamp output of 120 W / cm, a line speed of 15 m / min, and a distance between the lamp and the film of 150 mm with an ultraviolet irradiation device. Obtained. A 10 × 10 crosscut is made on the ink layer of the obtained film, and an 18 mm wide tape (Cellotape (registered trademark) CT-18 manufactured by Nichiban Co., Ltd.) is attached on the ink layer, and the peeling angle is 180 degrees. The peeled surface after peeling was observed, and if the peeled area was less than 5%, it was marked as ◎, if it was 5% or more and less than 20%, it was marked as ○, if it was 20% or more and less than 50%, it was marked as △, and if it was 50% or more, it was marked as × (adhesion). Gender 1). In the same manner, the adhesiveness of FD Carton ACE sumi-ro (offset printing ink manufactured by Toyo Ink Co., Ltd.), which is an active energy ray-curable ink, was evaluated (adhesiveness 2).

The polyester used in Examples and Comparative Examples was prepared as follows.
<Manufacturing method of polyester (A)>
Ester 100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, 30 ppm of ethyl acid phosphate with respect to the produced polyester, and 100 ppm of magnesium acetate / tetrahydrate as a catalyst with respect to the produced polyester in a nitrogen atmosphere at 260 ° C. A chemical reaction was allowed. Subsequently, 50 ppm of tetrabutyl titanate was added to the produced polyester, the temperature was raised to 280 ° C. over 2 hours and 30 minutes, the pressure was reduced to an absolute pressure of 0.3 kPa, and the mixture was further polycondensed for 80 minutes to achieve the ultimate viscosity. A polyester (A) of 0.63 was obtained.

<Manufacturing method of polyester (B)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, and magnesium acetate tetrahydrate as a catalyst were produced and subjected to an esterification reaction at 225 ° C. with 900 ppm in a nitrogen atmosphere. Subsequently, 3500 ppm of positive phosphoric acid was added to the produced polyester and 70 ppm of germanium dioxide was added to the produced polyester, the temperature was raised to 280 ° C. over 2 hours and 30 minutes, and the pressure was reduced to an absolute pressure of 0.4 kPa. It was melt polycondensed for 85 minutes to obtain a polyester (B) having an ultimate viscosity of 0.64.

<Manufacturing method of polyester (C)>
In the method for producing polyester (A), polyester (C) is obtained by using the same method as the method for producing polyester (A) except that 0.3 parts by weight of silica particles having an average particle size of 2 μm are added before melt polymerization. It was.

Examples of compounds constituting the coating layer are as follows.
(Compound example)
-Composite resin composed of acryloyl group-containing resin and urethane resin: (I)
Cresol novolac type epoxy resin with acryloyl group introduced (acryloyl group: cresol novolac type epoxy resin monomer = 1: 1.1 (mol%)) and isophorone diisocyanate: terephthalic acid: isophthalic acid: ethylene glycol: diethylene glycol: dimethylol A core-shell structure (core) made by mixing and dispersing a polyester-based urethane resin formed from propanoic acid = 12: 19: 18: 21: 25: 5 (mol%) at a solid content weight ratio of 1.0: 1.0. Water-dispersed composite resin (resin containing acryloyl group, urethane resin in shell) (weight ratio of acryloyl group to composite resin: 14% by weight (solid content ratio)).

・ Urethane resin: (II)
An aqueous dispersion of a polyester urethane resin formed from isophorone diisocyanate: terephthalic acid: isophthalic acid: ethylene glycol: diethylene glycol: dimethylolpropane acid = 12: 19: 18: 21: 25: 5 (mol%).

-Oxazoline compound: (IIIA)
Acrylic polymer epocross having an oxazoline group and a polyalkylene oxide chain (oxazoline group amount = 4.5 mmol / g, manufactured by Nippon Shokubai Co., Ltd.)

-Epoxy compound: (IIIB)
Polyglycerol Polyglycidyl ether.

・ Particles: (IV)
Silica sol with an average particle size of 0.07 μm

Example 1:
A mixed raw material in which polyesters (A), (B) and (C) are mixed at a ratio of 89%, 5% and 6%, respectively, is used as a raw material for the outermost layer (surface layer), and polyesters (A) and (B) are 95, respectively. The mixed raw material mixed at a ratio of% to 5% was used as a raw material for the intermediate layer, and each was supplied to two extruders, each of which was melted at 285 ° C., and then placed on a cooling roll set at 40 ° C. An unstretched sheet was obtained by co-extruding and cooling and solidifying with a layer structure of layers (surface layer / intermediate layer / surface layer = 1: 38: 1 discharge amount).
Next, after stretching 3.4 times in the longitudinal direction at a film temperature of 85 ° C. using the difference in roll peripheral speed, the coating liquid 1 shown in Table 1 below was applied to both sides of the vertically stretched film and guided to a tenter. It is stretched 4.0 times at 120 ° C in the lateral direction, heat-treated at 225 ° C, and then relaxed by 2% in the lateral direction, and the thickness of the coating layer (after drying) is 0.02 μm. A 250 μm polyester film was obtained. When the obtained polyester film was evaluated, the adhesiveness with the active energy curable ink layer was good. The characteristics of this film are shown in Table 2 below.

Examples 2-10:
In Example 1, a polyester film was obtained in the same manner as in Example 1 except that the coating agent composition was changed to the coating agent composition shown in Table 1. The finished polyester film was as shown in Table 2 and was an adhesive film.

Comparative Example 1:
A film was obtained in the same manner as in Example 1 except that the unstretched film was not provided with a coating layer. When the finished film was evaluated, as shown in Table 2, the adhesiveness of the film was poor.

Comparative Examples 2-5:
In Example 1, a polyester film was obtained in the same manner as in Example 1 except that the coating agent composition was changed to the coating agent composition shown in Table 1. When the finished laminated polyester film was evaluated, it was as shown in Table 2, and the adhesiveness was poor.

The film of the present invention can be suitably used for applications that require good adhesion to various functional layers, such as magnetic recording media, packaging materials, building materials, and display applications.

Claims (7)

A laminated film having a coating layer and a functional layer on at least one side of the film in this order, the functional layer being formed from an active energy ray-curable composition containing a compound having a carbon-carbon double bond. It is a layer, and the coating layer is a layer formed from a coating liquid containing a composite resin, and the composite resin is a core shell having a core containing a (meth) acryloyl group and a shell being a urethane resin. Ri composite resin der having a structure, wherein the film is a polyester film, laminated film titanium element content of the polyester constituting the polyester film area by der of 1 to 50 ppm. A laminated film having a coating layer and a functional layer on at least one side of the film in this order, the functional layer being formed from an active energy ray-curable composition containing a compound having a carbon-carbon double bond. It is a layer, and the coating layer is formed from a coating liquid containing a resin containing a (meth) acryloyl group having reactivity with the compound having a carbon-carbon double bond and a composite resin composed of a urethane resin. The urethane resin contains polyester polyols having a terephthalic acid component and an isophthalic acid component as polyol components, and the film is a polyester film and contains a titanium element of the polyester constituting the polyester film. laminated film amount area by der of 1 to 50 ppm. The laminated film according to claim 1 or 2, wherein the ratio of the (meth) acryloyl group contained in the composite resin is in the range of 1 to 50% by weight as the ratio of the entire composite resin. A laminated film having a coating layer and a functional layer on at least one side of the film in this order, the functional layer being formed from an active energy ray-curable composition containing a compound having a carbon-carbon double bond. It is a layer, and the coating layer is formed from a coating liquid containing a resin containing a (meth) acryloyl group having reactivity with the compound having a carbon-carbon double bond and a composite resin composed of a urethane resin. The film is a laminated film which is a polyester film having a titanium element content in the range of 1 to 50 ppm. The laminated film according to claim 4 , wherein the proportion of the (meth) acryloyl group contained in the composite resin is in the range of 1 to 50% by weight as the proportion of the entire composite resin. A step of applying a coating liquid containing a composite resin composed of a resin containing a (meth) acryloyl group and a urethane resin on at least one side of the film and then heat-treating to form a coating layer, and carbon-on the surface of the coating layer. It has a step of applying an active energy ray-curable composition containing a compound having a carbon double bond, and the compound having the carbon-carbon double bond reacts with the resin containing the (meth) acryloyl group. A method for producing a laminated film having properties, wherein the composite resin is in the range of 45 to 80% by weight as a ratio to all non-volatile components in the coating liquid. A step of applying a coating liquid containing a composite resin composed of a resin containing a (meth) acryloyl group and a urethane resin on at least one side of the film and then heat-treating to form a coating layer, and carbon-on the surface of the coating layer. After applying an active energy ray-curable composition containing a compound having a carbon double bond, a resin containing a (meth) acryloyl group present in the coating layer and a compound having the carbon-carbon double bond. A method for producing a laminated film, which comprises a step of forming a functional layer by reacting with the above, wherein the composite resin is in the range of 45 to 80% by weight as a ratio to the total non-volatile components in the coating liquid. Method.