JP2016055464A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film, which has greatly excellent adhesiveness with various functional layers to be laminated on the film, and therefore, which can be utilized preferably as each base material for, for example, a magnetic recording medium, various packaging materials, various housing materials, various display applications or the like.SOLUTION: A laminated film has, at least on one surface of the film, a coating layer formed of coating liquid containing a composite resin comprising a resin containing a (meth)acryloyl group and a urethane resin.SELECTED DRAWING: None

Description

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

  Although the film has been widely used because of its excellent properties, it has a drawback of poor adhesion depending on the application. For example, printing ink (cellophane printing ink, chlorinated PP ink, UV curable ink, magnetic ink, etc.), thermal transfer ink, magnetic paint, adhesive (lamination adhesive, wood bonding adhesive, etc.), vapor deposited Adhesion to metals and inorganic substances (aluminum, silver, gold, ITO, silicon oxide, aluminum oxide, etc.), mold release agent, ink image-receiving layer, gelatin, polyvinyl alcohol, polyvinyl acetal, cellulose acetate, cellulose butylacetate, methylcellulose, carboxymethylcellulose, etc. Inferior.

  As a method for improving the adhesiveness of the film, there are a method of treating the film with a solvent, a method of corona discharge treatment and plasma treatment, etc. (Patent Documents 1 and 2). The effect of improving the adhesion with the functional layer is insufficient, and a method of laminating an adhesive coating layer on the film by coating treatment has also been proposed, but still in the type of functional layer provided on the coating layer The case where adhesiveness was inadequate was seen (patent document 3).

JP-A-3-56541 JP 11-129378 A Japanese Patent Laid-Open No. 2004-001486

  This invention is made | formed in view of the said situation, Comprising: The solution subject is providing the laminated film excellent in adhesiveness with the functional layer laminated | stacked on a film.

  As a result of intensive studies in view of the above circumstances, the present inventors have found that the use of a laminated film having a specific configuration can easily solve the above-described problems, and have completed the present invention.

  That is, the gist of the present invention is a laminated film comprising a coating layer formed from a coating solution 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. Exist.

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

  As the film base 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, Examples thereof include a polystyrene film, a polyvinyl chloride film, a polyvinyl alcohol film, an ethylene vinyl acetate copolymer film, an ethylene-vinyl alcohol copolymer film, and a nylon film. In particular, in order to develop into various applications, it is preferable to have heat resistance, and polyester film, polycarbonate film, fluororesin film, and polyimide film are preferably used, and polyester is further considered in view of transparency, moldability, and versatility. A film is used more suitably.

  The film constituting the laminated film in the present invention may have a single-layer structure or a multilayer structure, and may have a multilayer structure of four or more layers as long as the gist of the present invention is not exceeded other than the two-layer or three-layer structure. There is no particular limitation.

  As the polyester film used as the film of the present invention, the polyester used may be a homopolyester or a copolyester. In the case of a homopolyester, those obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol are preferred. 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. Typical polyester includes polyethylene terephthalate and the like. On the other hand, the dicarboxylic acid component of the copolyester includes isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, p-oxybenzoic acid, etc.), etc. 1 type or 2 types or more are mentioned, As a glycol component, 1 type or 2 types or more, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 4-cyclohexane dimethanol, neopentyl glycol, is mentioned.

  There is no restriction | limiting in particular as a polymerization catalyst of polyester, A conventionally well-known compound can be used, For example, an antimony compound, a titanium compound, a germanium compound, a manganese compound, an aluminum compound, a magnesium compound, a calcium compound etc. are mentioned. 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 becomes high. Furthermore, since a 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 50 ppm or less, more preferably 1 to 20 ppm, and still more preferably 2 to 10 ppm. If the content of the titanium compound is too high, the polyester may be deteriorated in the process of melt-extruding the polyester, resulting in a strong yellowish film. If the content is too low, the polymerization efficiency is poor and the cost is low. In some cases, a film having a sufficient strength or a sufficient strength cannot be obtained. Moreover, when using the polyester by a titanium compound, it is preferable to use a phosphorus compound in order to reduce the activity of a titanium compound for the purpose of suppressing deterioration in the step of melt extrusion. As the phosphorus compound, orthophosphoric acid is preferable in view of the productivity and thermal stability of the polyester. The phosphorus element content is preferably in the range of 1 to 300 ppm, more preferably 3 to 200 ppm, and 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 large, it may cause gelation or foreign matter. If the content is too small, the activity of the titanium compound cannot be lowered sufficiently, and the yellowish It may be a film.

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

  The film of the present invention may contain an ultraviolet absorber for improving the weather resistance of the film and preventing the deterioration of the liquid crystal and the like. The ultraviolet absorber is not particularly limited as long as it is a compound that absorbs ultraviolet rays and can withstand the heat applied in the film production process.

  As the ultraviolet absorber, there are an organic ultraviolet absorber and an inorganic ultraviolet absorber. From the viewpoint of transparency, an organic ultraviolet absorber is preferable. Although it does not specifically limit as an organic type ultraviolet absorber, For example, a cyclic imino ester type, a benzotriazole type, a benzophenone type etc. are mentioned. From the viewpoint of durability, a cyclic imino ester type and a benzotriazole type are more preferable. It is also possible to use two or more ultraviolet absorbers in combination.

  In the film of the present invention, particles can be blended mainly for the purpose of imparting slipperiness and preventing the occurrence of scratches in each step. The kind of the particle to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness. Specific examples thereof include silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, and phosphoric acid. Examples 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. Furthermore, it is also possible to use precipitated particles in which a part of a metal compound such as a catalyst is precipitated and finely dispersed during the film production process.

The shape of the particles to be used is not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, and the like may be used. Moreover, there is no restriction | limiting in particular also about the hardness, specific gravity, a color, etc.
These series of particles may be used in combination of two or more as required.

The average particle diameter of the particles is preferably 5 μm or less, more preferably 0.01 to 3 μm. By using the average particle diameter within the above range, an appropriate surface roughness is imparted to the film, and in the case where various functional layers and the like are formed in a subsequent process, problems are unlikely to occur.

  Furthermore, the particle content in the film is preferably less than 5% by weight, more preferably in the range of 0.0003 to 3% by weight. When there are no or few particles, the transparency of the film becomes high and the film becomes a good film, but the slipperiness may be insufficient. There are cases where improvement is required. Moreover, when there is too much particle content, even if a functional layer is formed, haze will not fully fall, and transparency of a film may be inadequate.

  The method for adding particles to the film is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at an arbitrary stage for producing a film constituting each layer, but it is preferably added after completion of esterification or transesterification.

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

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

  Next, although the manufacture example of the film in this invention is demonstrated concretely, it is not limited to the following manufacture examples at all. In general, the resin is melted, formed into a sheet, and stretched for the purpose of increasing the strength and the film is formed. As an example, the case where the polyester film mentioned above is manufactured is introduced. A method of obtaining an unstretched film by cooling and solidifying a molten film extruded from a 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 adhesion between the film and the rotary cooling drum, and an electrostatic application adhesion method or a liquid application adhesion method is preferably employed. 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 a 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. Next, the film is stretched in the direction perpendicular to the first stretching direction. In that 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. Subsequently, heat treatment is performed at a temperature of 180 to 250 ° C. under tension or under relaxation within 30% to obtain a biaxially oriented film. In the above-described stretching, a method in which stretching in one direction is performed in two or more stages can be employed. In that case, it is preferable to carry out so that the draw ratios in the two directions finally fall within the above ranges.

  In the present invention, the simultaneous biaxial stretching method can be adopted for the production of the film constituting the laminated film. The simultaneous biaxial stretching method is a method in which the above-mentioned unstretched sheet is stretched and oriented simultaneously in the machine direction and the width direction in a state where the temperature is usually controlled at 70 to 120 ° C., preferably 80 to 110 ° C. As an area magnification, it is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times. Subsequently, heat treatment is performed at a temperature of 170 to 250 ° C. under tension or under relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, a conventionally known stretching method such as a screw method, a pantograph method, or a linear driving method can be employed.

  Next, formation of the coating layer which comprises the laminated | multilayer film in this invention is demonstrated. Regarding the coating layer, it may be provided by in-line coating, which treats the film surface during the film formation process, or may be applied off-system on a once manufactured film. More preferably, it is formed by in-line coating.

  In-line coating is a method in which coating is performed within the film production process, and specifically, a method in which coating is performed at any stage from melt extrusion of a resin to heat setting after stretching and winding up. 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 setting, and a film after heat setting and before winding. Although not limited to the following, for example, in sequential biaxial stretching, a method of stretching in the transverse direction after coating a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) is particularly excellent. According to such a method, film formation and coating layer formation can be performed at the same time, so there is an advantage in manufacturing cost. In addition, in order to perform stretching after coating, the thickness of the coating layer can be changed by the stretching ratio. Compared to offline coating, thin film coating can be performed more easily. 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. Furthermore, in the manufacture of biaxially stretched films, the film can be restrained in the vertical and horizontal directions by stretching while gripping the film edges with clips, etc., and flatness is not generated in the heat setting process. High temperature can be applied while maintaining Therefore, since the heat treatment performed after coating can be performed at 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, it can be set as a firm coating layer, and performances such as adhesion to various functional layers that can be formed on the coating layer and wet heat resistance can be improved.

  In the present invention, it is an essential requirement to have a coating layer formed from a coating solution 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. .

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

  By using a composite resin composed of a resin containing a (meth) acryloyl group and a urethane resin, a higher degree of adhesiveness could be expressed. The presumed mechanism of high adhesion expression is that carbon-carbon double bonds due to (meth) acryloyl groups present in the coating layer and carbon-carbon doubles 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 resins containing (meth) acryloyl groups but also composite resins with urethane resins, not only improved adhesion to functional layers, but also improved adhesion to the film as the substrate. It is speculated that the adhesiveness can be improved as a whole film.

  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 resins, polyester resins, and acrylic resins. Among these, an epoxy resin is preferable from the viewpoint of easy synthesis and introduction of 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, novolac type epoxy resins and bisphenol type epoxy resins are more preferable. In view of the introduction of acryloyl group, novolac type epoxy resin is more preferable.

  Examples of the novolak type epoxy resin include a cresol novolak type and a phenol novolak type, and examples of the bisphenol type epoxy resin include a bisphenol A type, a bisphenol F type, and a bisphenol S type. Among these, cresol novolac type epoxy resins and bisphenol A type epoxy resins are more preferable in consideration of versatility and resin flexibility. Moreover, epoxy resin may be used by a single kind or may be used together with multiple types.

  Conventionally known urethane resins can be used as the resin containing the (meth) acryloyl group and the urethane resin for forming the composite resin. Usually, urethane resin is prepared by reaction of polyol and isocyanate. Examples of the polyol include polyester polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination. In view of the adhesiveness with the polyester film substrate, among the above, polyester polyols are more preferable. Moreover, when considering water resistance, among the above, polycarbonate polyols are more preferable.

  Polyester polyols include polycarboxylic acids (terephthalic acid, isophthalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, etc.) or their acid anhydrides. Product and polyhydric alcohol (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-dimethyl-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, cyclohexane Diol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyl dialkanolamine, lactone diol, etc.).

  Among these, from the viewpoint of durability such as water resistance and solvent resistance, the polyvalent carboxylic acid is preferably an aromatic carboxylic acid, among them, considering the coating appearance and adhesiveness with the film substrate, Terephthalic acid and isophthalic acid are more preferable. In particular, in view of 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 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 it is the range of 1-2: 1-2.

  Furthermore, 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. Those are preferred. In view of durability, coating appearance, and flexibility, it is more preferable to use ethylene glycol and diethylene glycol in combination. The molar ratio of ethylene glycol: diethylene glycol used in combination is preferably 1 to 10: 1 to 10, more preferably 1 to 5: 1 to 5, further preferably 1 to 3: 1 to 3, particularly preferably. Is in the range of 1-2: 1-2.

  Polycarbonate polyols are obtained from a polyhydric alcohol and a carbonate compound by a dealcoholization reaction. Examples of the polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 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 Diol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylol heptane and the like can be mentioned. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate. Examples of polycarbonate polyols obtained from these reactions include poly (1,6-hexylene) carbonate, poly (3- And methyl-1,5-pentylene) carbonate.

  Examples of 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 for obtaining the urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate, α, α, α ′, α ′. -Aliphatic diisocyanates having aromatic rings such as tetramethylxylylene diisocyanate, aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl Methanzi Cyanate, alicyclic diisocyanates such as isopropylidene dicyclohexyl diisocyanates. These may be used alone or in combination. Among these, in consideration of yellowing, it is preferable not to be 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 an isocyanate 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. And glycols such as glycols. Examples of the chain extender having two amino groups include aromatic diamines such as tolylenediamine, xylylenediamine, 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 decane diamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropylidenecyclohexyl-4,4′-diamine, 1,4-diaminocyclohexane, 1, 3-Bisaminomethylcyclohexa And alicyclic diamines such as

  The urethane resin in the present invention may use a solvent as a medium, but preferably uses water as a medium. In order 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, and a water-soluble type. In particular, a self-emulsification type in which an ionic group is introduced into the structure of a urethane resin to form an ionomer is preferable because of excellent storage stability of the liquid and water resistance, transparency, and adhesiveness of the resulting coating layer.

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

  For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis- (2-hydroxyethyl) propionic acid, bis- (2-hydroxyethyl) butanoic acid and the like are copolymerized with a diol used for polymerization of a urethane resin. Can do. The carboxyl group is preferably in the form of a salt neutralized with ammonia, amine, alkali metal, inorganic alkali or the like. Particularly preferred are ammonia, trimethylamine and triethylamine. In such a polyurethane resin, a carboxyl group from which the neutralizing agent has been removed in the drying step after coating can be used as a crosslinking reaction point by another crosslinking agent. Thereby, it is possible to further improve the durability, solvent resistance, water resistance, blocking resistance, and the like of the obtained coating layer, as well as excellent stability in a liquid state before coating.

  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, if the urethane resin is a type containing a hydrophilic group, in a state where the urethane resin is dispersed or dissolved in an aqueous medium, a resin alone containing a (meth) acryloyl group, or It can be synthesized by mixing and stirring a resin containing a (meth) acryloyl group dispersed or dissolved in a solvent. When the resin containing a (meth) acryloyl group has no or few hydrophilic groups, it becomes hydrophobic and is preferably mixed with a dispersion or solution of a 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 is dispersed or dissolved by reducing the pressure, the resin containing the hydrophobic (meth) acryloyl group is the core. It becomes possible to obtain a composite resin emulsion having a core-shell structure in which a hydrophilic urethane resin becomes a shell. The core-shell structure is more preferable because it provides liquid stabilization and can be stably present even when mixed with other components and can be used widely. Also, according to the method of the above example, since the core and the shell are not bonded, when the emulsion is broken by solvent removal by drying after coating, the core and the shell can move freely separately. The (meth) acryloyl group in the portion can also appear on the surface of the coating layer, which can be advantageous for improving the adhesion with various functional layers that can be formed on the coating layer.

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

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

  In forming the coating layer in the film of the present invention, various polymers can be used in combination for improving the coating appearance, transparency and adhesion.

  Specific examples of the polymer include urethane resin, polyester resin, acrylic resin, polyvinyl (polyvinyl alcohol, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, etc.), polyalkylene glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, and starches. Etc.

  In addition, in the formation of the coating layer in the film of the present invention, a crosslinking agent is used in combination in order to strengthen the coating layer of the coating layer and to improve the sufficient adhesiveness and moist heat resistance properties with the active energy ray-curable ink layer and the like. It is preferable.

  Specific examples of the crosslinking agent include oxazoline compounds, epoxy compounds, carbodiimide compounds, isocyanate compounds, melamine compounds, silane coupling compounds, hydrazide compounds, aziridine compounds, and the like. Among these, oxazoline compounds, epoxy compounds, carbodiimide compounds, and isocyanate 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 can be prepared by polymerization of an addition polymerizable oxazoline group-containing monomer alone or with another monomer. Addition 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, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be mentioned, and one or a mixture of two or more thereof can be used.

  Among these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially. The other monomer is not limited as long as it is a monomer copolymerizable with an addition polymerizable oxazoline group-containing monomer. For example, alkyl (meth) acrylate (the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, (meth) acrylic acid esters such as n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene Unsaturated carboxylic acids such as sulfonic acid and its salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); Unsaturated nitriles such as acrylonitrile, methacrylonitrile; (meth) acrylamide, N-alkyl ( (Meth) acrylamide, N, N-dialkyl (meth) acrylamide, As the alkyl group, unsaturated amides such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group and cyclohexyl group); vinyl acetate Vinyl esters such as vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride And α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and the like, and one or more of these monomers 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. / G. Use within the above range is preferable because adhesion to various functional layers is improved.

  The epoxy compound is a compound having an epoxy group in the molecule, and examples thereof include condensates of epichlorohydrin with ethylene glycol, polyethylene glycol, glycerin, polyglycerin, bisphenol A and the like hydroxyl groups and amino groups, 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, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane. Examples of the polyglycidyl ether and 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, poly Examples of tetramethylene glycol diglycidyl ether and monoepoxy compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and glycidyl amine compounds such as N, N, N ′, N′-tetraglycidyl-m-xylyl. Examples include range amine and 1,3-bis (N, N-diglycidylamino) cyclohexane.

  A carbodiimide-based compound is a compound having a carbodiimide structure, and is a compound having one or more carbodiimide structures in the molecule. For better adhesion, etc., the polycarbodiimide having two or more in the molecule More preferred are system compounds.

  The carbodiimide compound can be synthesized by a conventionally known technique, and generally a condensation reaction of a diisocyanate compound is used. The diisocyanate compound is not particularly limited, and any of aromatic and aliphatic compounds can be used. Specifically, tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexa Examples include methylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate.

  Furthermore, in order not to lose the effect of the present invention, in order to improve the water solubility and water dispersibility of the polycarbodiimide compound, adding a surfactant, polyalkylene oxide, quaternary ammonium salt of dialkylamino alcohol, You may add and use hydrophilic monomers, such as a hydroxyalkyl sulfonate.

  The isocyanate 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, phenylene diisocyanate, and naphthalene diisocyanate, and aromatic rings such as α, α, α ′, α′-tetramethylxylylene diisocyanate. Aliphatic isocyanates such as aliphatic isocyanate, methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), isopropylidene dicyclohexyl diisocyanate Ne Alicyclic isocyanates such as bets are exemplified.

  Further, polymers and derivatives such as burettes, isocyanurates, uretdiones, and carbodiimide modified products of these isocyanates are also included. These may be used alone or in combination. 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, bisulfites, phenolic compounds such as phenol, cresol, and ethylphenol, and alcohols 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 and 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, acetanilide, acid amide compounds of acetic acid amide, formaldehyde, acetoald Examples include oxime compounds such as oxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime, and these may be used alone or in combination of two or more.

  In addition, the isocyanate compound in the present invention may be used alone, or may be used as a mixture or bond with various polymers. In the sense 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.

  The melamine compound is a compound having a melamine skeleton in the compound. For example, an alkylolized melamine derivative, a compound partially or completely etherified by reacting an alcohol with an alkylolated melamine derivative, and these Mixtures can be used. As alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. Moreover, as a melamine compound, either a monomer or a multimer more than a dimer may be sufficient, or a mixture thereof may be used. Further, a product obtained by co-condensing urea or the like with a part of melamine can be used, and a catalyst can be used to increase the reactivity of the melamine compound.

  These cross-linking agents are used in a design that improves the performance of the coating layer by reacting in the drying process or film forming process. It can be inferred that unreacted products of these crosslinking agents, compounds after the reaction, or mixtures thereof exist in the finished coating layer.

  Moreover, in order to improve slipperiness and blocking, it is preferable to use particles together in forming the coating layer. The average particle diameter 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 still more preferably 0.01 μm to 0.2 μm, from the viewpoint of film transparency.

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

  Further, in the range not impairing the gist of the present invention, an antifoaming agent, a coating property improver, a thickener, an organic lubricant, an antistatic agent, an ultraviolet absorber, and an antioxidant are formed as necessary for forming the coating layer. , Foaming agents, dyes, pigments and the like may be used in combination.

  As a ratio with respect to all nonvolatile components in the coating solution for forming the coating layer in the film of the present invention, the composite resin composed of a resin containing a (meth) acryloyl group and a urethane resin is usually 5% by weight or more, preferably 35% by weight. As mentioned above, More preferably, it is the range of 45 to 99 weight%. When 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, a coating layer can also be provided on the surface opposite to the surface on which the coating layer is provided. The opposite surface can be a coating layer according to the application, and conventionally known components can be used as its constituent components. Examples include urethane resins, polyester resins, acrylic resins and other polymers, oxazoline compounds, epoxy compounds, carbodiimide compounds, isocyanate compounds, melamine compounds and other crosslinking agents, and these materials may be used alone. A plurality of types may be used in combination. Moreover, the coating layer (the same coating layer on both surfaces of a film) formed from the coating liquid containing the composite resin which consists of resin containing a (meth) acryloyl group and urethane resin as mentioned above may be sufficient.

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

  When the coating layer is provided by in-line coating, the above-mentioned series of compounds is used as an aqueous solution or water dispersion, and the coating solution prepared by adjusting the solid content concentration to about 0.1 to 50% by weight as a guide is applied to the film. It is preferable to produce a laminated film. Moreover, in the range which does not impair the main point of this invention, a small amount of organic solvents may be contained in the coating liquid for the purpose of improving dispersibility in water, improving film-forming properties, and the like. Only one type of organic solvent may be used, or two or more types may be used as appropriate.

  Regarding 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, and still more preferably 0.005 to 0.3 μm. Especially preferably, it is the range of 0.01-0.2 micrometer. When the film thickness is out of the above range, the adhesiveness, coating appearance, and blocking characteristics may be deteriorated.

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

  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 off-line coating, it is usually 80 to 200 ° C. for 3 to 40 seconds. The heat treatment is preferably performed 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, heat treatment is usually performed at 70 to 280 ° C. for 3 to 200 seconds as a guide.

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

  The use of providing various functional layers on the coating layer of the laminated film of the present invention is common, and among the functional layers, it is difficult to ensure an active energy curable resin layer and, moreover, adhesion. It is a functional layer based on a solvent-free system (usually 5% by weight or less, preferably 3% by weight or less, more preferably 1% by weight or less, more preferably no solvent), and is characterized in that an ink layer can be provided. In such fields, the film of the present invention is suitable.

  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. In addition, when the film is dried after film formation in the wet coating method, an arbitrary amount of solvent can be added.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded. The measurement method and evaluation method used in the present invention are as follows.

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

(2) Measuring method of average particle diameter The coating layer was observed using TEM (H-7650 manufactured by Hitachi High-Technologies Corporation, acceleration voltage 100V), and the average value of the particle diameters of 10 particles was defined as the average particle diameter. .

(3) Content of (meth) acryloyl group in composite resin After the composite resin was dried under reduced pressure, each peak of ¹ H and ¹³ C was assigned using NMR (AVANCE III600 manufactured by Bruker Biospin) and obtained by calculation. .

(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. Thereafter, the section prepared by the ultrathin section method is stained with RuO ₄ , and the cross section of the coating layer is measured using TEM (H-7650 manufactured by Hitachi High-Technologies Corporation, acceleration voltage 100V), and the average value of 10 places is applied. It was set as the film thickness of the layer.

(5) Adhesive evaluation method FD Carton ACE Indigo (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 on which an ink layer having a thickness of 3 μm is formed by irradiating ultraviolet rays with an ultraviolet ray irradiation device under the effective conditions of a metal halide lamp output of 120 W / cm, a line speed of 15 m / min, and a gap between the lamp and the film of 150 mm. Obtained. A 10 × 10 cross cut was made on the ink layer of the obtained film, and a 18 mm wide tape (Cello Tape (registered trademark) CT-18 manufactured by Nichiban Co., Ltd.) was applied on the ink layer. The peeled surface after peeling was observed. If the peeled area was less than 5%, ◎ if it was 5% or more but less than 20%, △ if it was 20% or more but less than 50%, or x if it was 50% or more (adhesion) Sex 1). In the same manner, the adhesiveness of FD Carton ACE Sumiro (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 the examples and comparative examples was prepared as follows.
<Method for producing polyester (A)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, 30 ppm of ethyl acid phosphate with respect to the resulting polyester, and 100 ppm of magnesium acetate tetrahydrate with respect to the resulting polyester as the catalyst at 260 ° C. in a nitrogen atmosphere at 260 ° C. The reaction was allowed to proceed. Subsequently, 50 ppm of tetrabutyl titanate was added to the resulting polyester, the temperature was raised to 280 ° C. over 2 hours and 30 minutes, the pressure was reduced to 0.3 kPa in absolute pressure, and melt polycondensation was further carried out for 80 minutes. 0.63 polyester (A) was obtained.

<Method for producing polyester (B)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, and magnesium acetate tetrahydrate as a catalyst were subjected to an esterification reaction at 225 ° C. in a nitrogen atmosphere at 900 ppm with respect to the produced polyester. Subsequently, 3500 ppm of orthophosphoric 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. After 85 minutes of melt polycondensation, polyester (B) having an intrinsic viscosity of 0.64 was obtained.

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

Examples of compounds constituting the coating layer are as follows.
(Example compounds)
-Composite resin consisting of resin containing acryloyl group and urethane resin: (I)
Cresol novolak type epoxy resin (acryloyl group: cresol novolak type epoxy resin monomer = 1: 1.1 (mol%)) and isophorone diisocyanate: terephthalic acid: isophthalic acid: ethylene glycol: diethylene glycol: dimethylol introduced with acryloyl group Polyester urethane resin formed from propanoic acid = 12: 19: 18: 21: 25: 5 (mol%) is mixed and dispersed at a solid content weight ratio of 1.0: 1.0 to form a core-shell structure (core A water-dispersed composite resin (a weight ratio of the acryloyl group to the composite resin: 14% by weight (solid content ratio)).

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

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

・ Epoxy compounds: (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 each 95 %, 5% mixed raw materials were used as intermediate layer raw materials, each was supplied to two extruders, melted at 285 ° C., and then on a cooling roll set at 40 ° C. Coextruded with a layer structure of layers (surface layer / intermediate layer / surface layer = 1: 38: 1 discharge amount) and cooled and solidified to obtain an unstretched sheet.
Next, the film was stretched 3.4 times in the longitudinal direction at a film temperature of 85 ° C. using the difference in peripheral speed of the roll, and then the coating liquid 1 shown in Table 1 below was applied to both sides of the longitudinally stretched film, and led to a tenter. Thickness having a coating layer in which the film is stretched 4.0 times at 120 ° C. in the transverse direction and heat-treated at 225 ° C. and then relaxed by 2% in the transverse direction and the coating layer thickness (after drying) is 0.02 μm. A polyester film of 250 μm was obtained. When the obtained polyester film was evaluated, the adhesiveness with the active energy curable ink layer was good. The properties of this film are shown in Table 2 below.

Examples 2-10:
In Example 1, it manufactured similarly to Example 1 except having changed the coating agent composition into the coating agent composition shown in Table 1, and obtained the polyester film. The finished polyester film was as shown in Table 2 and was an adhesive film.

Comparative Example 1:
In Example 1, it manufactured similarly to Example 1 except not providing an application layer in an unstretched film, and obtained the film. When the completed film was evaluated, as shown in Table 2, the adhesion of the film was poor.

Comparative Examples 2-5:
In Example 1, it manufactured similarly to Example 1 except having changed the coating agent composition into the coating agent composition shown in Table 1, and obtained the polyester film. The finished laminated polyester film was evaluated and as shown in Table 2, the adhesiveness was poor.

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

Claims (2)

A laminated film comprising a coating layer formed from a coating solution 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. The laminated film according to claim 1, wherein the film is a polyester film.