JP2008307757A - Coated film and vapor deposition film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition film which is excellent in gas barrier properties against oxygen and water vapor and having the feature that the gas barrier property does not deteriorate even when the film is bent, and to provide a coated film used as the base material of the vapor deposition film and showing high gas barrier properties. <P>SOLUTION: The coated film is prepared by overlaying a substrate consisting of a polymer resin composition with a coating layer that comprises a melamine compound, a polyvinyl alcohol polymer and a compound having a carboxyl group, characterized in that the thickness of the coated film is 5-50 μm, and the mass of formaldehyde and the mass of an alcohol generated from the coated film, when it is heated at 130°C, are each ≤50 ppm of the mass of the coated film sample. The vapor deposition film is prepared by depositing an inorganic thin layer on the coating layer of the above film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas barrier coating film and a vapor deposition film used in the packaging field of foods, pharmaceuticals and the like.

  Packaging materials used for foods, pharmaceuticals, etc. are 1) the ability to block the oxidation of proteins and oils, 2) the preservation of taste and freshness, and 3) the ability to shut off gases such as oxygen and water vapor in order to maintain the efficacy of pharmaceuticals. It is required to have gas barrier properties.

  Therefore, a polymer resin generally known to have a relatively high gas barrier property such as polyvinyl alcohol (hereinafter referred to as PVA), ethylene vinyl alcohol copolymer (EVOH), or polyvinylidene chloride resin (hereinafter referred to as PVDC). Films laminated with compositions have been used as packaging materials. Also, a film of a suitable polymer resin composition (even if it is a resin that does not have high gas barrier properties alone) is deposited with a metal such as Al, or an inorganic oxide such as alumina or silica. Things are also starting to be commonly used as packaging materials.

However, since the gas barrier laminate film using the above-mentioned PVA and EVOH polymer resin composition has a large temperature dependency and humidity dependency, the gas barrier property is lowered at high temperature or high humidity. That is, when a boiling process or a retort process is performed, the gas barrier properties are significantly lowered. Gas barrier laminate film with PVDC-based polymer resin composition may also, although the humidity dependence of the gas barrier properties is small, the such a high degree of gas barrier properties and 10ml / m ² · day · MPa or less in oxygen barrier property It is difficult to realize. In addition, since the coating contains a large amount of chlorine, there is a problem in terms of waste treatment such as incineration and recycling.

  In addition, the above-mentioned metal-deposited films and films deposited with inorganic oxides such as alumina and silica have very different physical properties such as mechanical properties, chemical properties, and thermal properties between the deposits and the resin films. Therefore, the inorganic thin film used for the gas barrier layer lacks flexibility and is weak against stagnation and bending. Moreover, since the adhesiveness with a base material is bad, handling is required and there exists a problem which a crack generate | occur | produces at the time of post-processing of packaging materials, such as printing, a laminate, and a bag making, and gas barrier property falls remarkably. Furthermore, because the device is formed using a vacuum process, the equipment is expensive, locally high temperatures are formed in the formation process, the substrate is damaged, additives such as low molecular weight substances and plasticizers are decomposed and degassed, etc. As a result, defects, pinholes, etc. may occur in the deposited layer. That is, conventional vapor deposition films have a problem that they cannot achieve high gas barrier properties and are expensive in cost.

Further, Patent Document 1 proposes a gas barrier material in which a metal alkoxide film is formed on a base material for the above problem. Since this gas barrier material has a certain degree of flexibility and can be manufactured by a liquid phase coating method, it can be made inexpensive in terms of cost. However, the gas barrier material has a slightly improved gas barrier property as compared with the case of a single base material, but is not sufficient, and a high level of gas barrier property is not realized at present.
JP-A-62-295931

  An object of this invention is to provide the vapor deposition film which is excellent in the gas barrier property of oxygen and water vapor | steam, and a gas barrier property does not fall even at the time of bending. Moreover, it aims at providing the coating film which expresses the high gas barrier property used as a base material of a vapor deposition film.

  The present invention that has solved the above problems is a coated film in which a coating layer comprising a melamine compound, a polyvinyl alcohol polymer, and a compound having a carboxyl group as an essential component is laminated on a substrate made of a polymer resin composition. The thickness of the coated film is 5 to 50 μm, and the mass of formaldehyde and alcohol generated from the coated film when heated at 130 ° C. is 50 ppm or less of the mass of the coated film sample, respectively. Has a summary.

  An embodiment in which the compound having a carboxyl group is a (meth) acrylic acid polymer and / or a maleic acid polymer, and the coating layer has a melamine compound, a polyvinyl alcohol polymer, and a compound having a carboxyl group as a melamine compound / As a mass ratio of the compound having a polyvinyl alcohol polymer / carboxyl group, an aspect in which 24-89 / 10 to 75/1 to 50 are included, and an aspect in which the thickness of the coating layer is 0.05 to 0.50 μm, All are preferred embodiments of the coated film of the present invention.

The vapor deposition film obtained by vapor-depositing an inorganic thin film layer on the coating layer of the said coating film is also contained in this invention. The water-resistant adhesion strength of the deposited film is preferably 6 N / 15 mm or more, and when the deposited film is subjected to a gelbo test, the oxygen permeability and water vapor permeability before and after the gelbo test satisfy the following formula 1). It is preferable.
Formula 1) (Permeability after gelbo test-permeability before gelbo test) / permeation before gelbo test ≦ 0.2

  According to the present invention, the coating layer appearance, oxygen barrier property, and water vapor barrier property are excellent, and there is little deterioration of the barrier property against external force such as bending, and the incineration exhaust gas does not contain dioxin or hydrogen chloride gas and is effective for environmental conservation Economical film can be provided economically.

  Hereinafter, embodiments of the coating film and the vapor deposition film of the present invention will be described.

[Base material layer]
The base material layer used in the present invention is, for example, a film obtained by melting and extruding an organic polymer and stretching, cooling, and heat setting in the longitudinal direction and / or the width direction as necessary. Polyamides represented by nylon 4,6, nylon 6, nylon 6,6, nylon 12, etc .; polyesters represented by polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, etc .; polyethylene, polypropylene, polybutene, etc. In addition to the polyolefins represented by (1), polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, wholly aromatic polyamide, polyamideimide, polyimide, polyetherimide, polysulfone, polystyrene, polylactic acid and the like can be mentioned.

  The base material layer in the present invention may be a laminated film. There are no particular limitations on the type of laminate, the number of laminations, the lamination method, and the like in the case of a laminated film, and any one of known methods can be selected according to the purpose.

[Coating layer]
A specific coating layer is laminated on at least one surface of such a base material layer. As a coating layer, a melamine compound, a polyvinyl alcohol polymer, and a compound having a carboxyl group are essential components.

  In the melamine-based compound used in the present invention, at least a part of the hydrogen atoms of three amino groups bonded to the triazine ring are substituted with methylol groups, and the number of the methylol groups is generally 3 to 6. And a part or all of the methylol group is alkyl etherified. The alkyl portion of the alkyl etherified melamine compound has 1 to 6 carbons, preferably 1 to 3 carbons, and is linear or branched. Specific examples thereof include methyl, ethyl, n- or iso-propyl, n-, iso- or tert-butyl. Specific examples of melamine compounds used in the present invention include hexamethylol melamine hexamethyl ether, hexamethylol melamine pentamethyl ether, hexamethylol melamine tetramethyl ether, pentamethylol melamine pentamethyl ether, pentamethylol melamine tetramethyl ether. , Pentamethylol melamine trimethyl ether, tetramethylol melamine tetramethyl ether, tetramethylol melamine trimethyl ether, trimethylol melamine trimethyl ether, trimethylol melamine dimethyl ether, and the like. Methylol melamine trimethyl ether and trimethylol melamine dimethyl ether are preferably usedThe melamine-based compound may partially contain a condensate such as a dimer.

  On the other hand, the degree of polymerization and the degree of saponification of the polyvinyl alcohol polymer are determined from the target gas barrier properties and the viscosity of the coating aqueous solution. When the degree of polymerization becomes high, the aqueous solution viscosity becomes high, so that coating becomes difficult, and the degree of polymerization is preferably 2600 or less from the viewpoint of coat workability. When the saponification degree is less than 90%, sufficient oxygen gas barrier properties under high humidity cannot be obtained, and when it exceeds 99.7%, it is difficult to prepare an aqueous solution, gelation tends to occur, and it is not suitable for industrial production. Therefore, the saponification degree is preferably 90 to 99.7%, more preferably 93 to 99%. In addition, other various copolymerized or modified polyvinyl alcohol polymers such as a polyvinyl alcohol polymer containing a silanol group can be arbitrarily used as long as the desired transparency and gas barrier properties are not impaired.

  One of the features of the present invention is that a compound having a carboxyl group is an essential component of the coating layer. When the compound having a carboxyl group reacts with the polyvinyl alcohol polymer and the melamine compound, the hydrophilicity of the coating layer decreases, and the compatibility between the polyvinyl alcohol polymer and the melamine compound increases. Moreover, the water vapor | steam barrier property of a coating layer improves and in a vapor deposition film, water-resistant adhesion strength improves.

  Examples of the compound having a carboxyl group used in the present invention include saturated or unsaturated linear or branched aliphatic monocarboxylic acid, aliphatic substituted monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, aromatic Examples thereof include monocarboxylic acids such as substituted monocarboxylic acids, dicarboxylic acids, and polyvalent carboxylic acids (trivalent or higher).

  Examples of saturated linear aliphatic monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, pentanoic acid, caproic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid Examples include acids, behenic acid, and montanic acid. Examples of unsaturated linear aliphatic monocarboxylic acids include acrylic acid, methacrylic acid, oleic acid, linoleic acid, linolenic acid, and the like.

  Examples of the saturated branched aliphatic monocarboxylic acid include α-methylbutyric acid, α, β-dimethylvaleric acid, 2-methylbutanoic acid, 2-ethylhexanoic acid, isostearic acid and the like. Examples of unsaturated branched aliphatic monocarboxylic acids include 2-methyl-3-butenoic acid and 4-ethyl-6-octadecenoic acid. Examples of the aliphatic substituted monocarboxylic acid include 2-bromopropanoic acid and γ-chloro-α-methylbutyric acid.

  Examples of the alicyclic monocarboxylic acid include cyclohexanecarboxylic acid. Examples of the aromatic monocarboxylic acid include phenylacetic acid, benzoic acid, γ-phenylbutyric acid, o-toluic acid, 3-phenylpropanoic acid and the like. Examples of the aromatic substituted monocarboxylic acid include p-nitrobenzoic acid, p-methoxybenzoic acid, p-bromobenzoic acid, 3- (p-chlorophenyl) butanoic acid and the like.

  Examples of dicarboxylic acids include alkylene dicarboxylic acids (eg, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, dodecenyl succinic acid, pentadecenyl succinic acid, octadecenyl succinic acid, Dimer acid, etc.), alkenylene dicarboxylic acid (eg, maleic acid, fumaric acid, etc.), aromatic dicarboxylic acid (eg, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.).

  Examples of polyvalent carboxylic acids (trivalent or higher) include aliphatic polycarboxylic acids (eg, citric acid, 1,2,3,4-butanetetracarboxylic acid, 1,2,3,4,5-pentanepenta). Carboxylic acids), aromatic polycarboxylic acids (eg, trimellitic acid, pyromellitic acid, meritic acid, etc.), vinyl polymers of unsaturated carboxylic acids (eg, (meth) acrylic acid polymers (eg, polyacrylic acid) , Polymethacrylic acid, acrylic acid-methacrylic acid copolymer, (meth) acrylic acid- (meth) acrylic acid ester copolymer, etc.), (meth) acrylic acid-based polymer partial neutralized product, polyitaconic acid, maleic acid-based Polymer (eg, polymaleic acid, olefin-maleic acid copolymer represented by ethylene-maleic anhydride, etc.) and the like.

  Among the above, from the viewpoint of reactivity with polyvinyl alcohol and melamine compound, the compound having a carboxyl group is preferably a polyvalent carboxylic acid, (meth) acrylic acid polymer such as poly (meth) acrylic acid, maleic acid, and the like. A polymer is more preferable. In addition, the compound which has these carboxyl groups may have a partly neutralized carboxyl group.

  In the present invention, the mass ratio of the melamine compound / polyvinyl alcohol polymer / the compound having a carboxyl group can be arbitrarily selected, but is preferably 24 to 89/10 to 75/1 to 50 from the viewpoint of gas barrier properties. is there. In the coating layer, these compounds react with each other and therefore do not exist alone, but are considered as mass ratios of portions derived from these compounds. If the mass ratio is out of the above range, the target oxygen barrier property and water vapor barrier property may not be sufficiently exhibited, or the water adhesion resistance may be insufficient. The mass ratio is more preferably 39 to 89/10 to 60/1 to 50, and further preferably 54 to 89/10 to 45/1 to 36.

  In the coating layer in the present invention, it is preferable that 0.01 to 5% by mass of the polyalkylene glycol surfactant is mixed with the polyvinyl alcohol polymer. By mixing a polyalkylene glycol surfactant, a film with few coating defects can be obtained, and gas barrier properties can be improved. When the mixing amount of the polyalkylene glycol surfactant is less than 0.01% by mass, the wettability to the base film tends to be insufficient, and the film may have many coating defects. On the other hand, when the mixing amount of the polyalkylene glycol surfactant exceeds 5% by mass, the hydrophilicity of the coating layer is increased and the oxygen barrier property under high humidity may be deteriorated.

  Examples of such polyalkylene glycol surfactants include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, higher alkylamine ethylene oxide adducts, Examples include fatty acid amide ethylene oxide adducts, fat and oil ethylene oxide adducts, and polypropylene glycol ethylene oxide adducts. Among these, higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, and polypropylene glycol ethylene oxide adducts are preferable in that the oxygen gas barrier property is not lowered. Often, HLB (Hydrophile-Lipophile Balance) is used as an indicator of these hydrophilic properties, and those having an HLB of 10 to 17 are preferred from the viewpoint of compatibility with a polyvinyl alcohol polymer and film-forming properties. .

  The water contact angle of the coating layer comprising such a melamine compound, a polyvinyl alcohol polymer, and a carboxyl group-containing component as essential components is 30 degrees or more from the viewpoint of expression of water vapor barrier properties after vapor deposition of the inorganic thin film layer. It is preferable. When the water contact angle of the coating layer is less than 30 degrees, sufficient water vapor barrier properties cannot be obtained. In order to increase the water contact angle, it is effective to increase the reaction temperature of each compound.

  In the present invention, a coating layer containing, as essential components, a melamine compound in which part or all of the methylol group is alkyletherified, a polyvinyl alcohol polymer, and a compound having a carboxyl group is usually coated using a solvent. Is formed. As a solvent for the coating liquid, it is preferable to use 100% water or a water / lower alcohol mixed solvent from the viewpoint of solubility. The lower alcohol is an alcoholic compound having a linear or branched aliphatic group having 1 to 3 carbon atoms, and specific examples include methyl alcohol, ethyl alcohol, ethylene glycol, n- or iso-propyl alcohol. It is done. Iso-propyl alcohol is particularly preferable. The total solid concentration of the coating liquid is preferably 2 to 35% by mass, and usually 5 to 30% by mass.

  In addition, there is no particular limitation on the order of preparation of the coating liquid raw material, but from the point of miscibility of the raw materials, addition of the above solvent, polyvinyl alcohol polymer, melamine compound, compound having a carboxyl group, catalyst, etc. A method of mixing and stirring in the order of agents is preferred. In preparing the coating liquid raw material, the polyvinyl alcohol polymer, the melamine compound and the compound having a carboxyl group may be mixed in the form of a solution dissolved in the solvent.

  Further, if necessary, it is optional to add various known inorganic and organic additives such as antistatic agents, slip agents, and antiblocking agents to the coating layer as long as they do not impair the object of the present invention.

  By using the coating liquid, a coating layer containing, as essential components, a melamine compound, a polyvinyl alcohol polymer, and a compound having a carboxyl group is formed on the substrate. As a method of forming the coating layer on the substrate, a method of coating the substrate with an aqueous solution is usually employed as described above. The method of coating is not limited, but is selected according to the coating amount and viscosity of the coating liquid to be used. What is necessary is just to employ | adopt from the fountain bar coating method, the fountain reverse roll coating method, the die coating method, etc.

  The coating thickness (thickness of the coating layer) in the present invention is preferably 0.05 to 0.50 μm, and particularly preferably 0.10 to 0.30 μm, from the viewpoint of gas barrier properties and economy. When the coat thickness is less than 0.05 μm, oxygen barrier properties and water vapor barrier properties are not sufficiently exhibited. On the other hand, if the coat thickness exceeds 0.50 μm, the formaldehyde and lower alcohol components in the film increase, which not only lowers the gas barrier property, but also increases the production cost and the economic efficiency.

  The conditions for drying and heat treatment during coating depend on the thickness of the coat and the conditions of the apparatus, but it is preferable that the coating is sent to the stretching step in the perpendicular direction immediately after coating and dried in the preheating zone or stretching zone of the stretching step. In such a case, it is normally performed at about 50 to 250 ° C. Thereby, the coating film of this invention is obtained. If necessary, the base film may be subjected to corona discharge treatment or other surface activation treatment, or may be subjected to anchor treatment using a known anchor treatment agent before forming the coating layer.

  In the coated film of the present invention, the amount of formaldehyde and alcohol generated when heated at 130 ° C. is 50 ppm or less of the mass of the sample film, respectively. Examples of the alcohol generated upon heating include lower alcohols such as methyl alcohol, ethyl alcohol, ethylene glycol, n- or iso-propyl alcohol, n-, iso-, or tert-butyl alcohol. When the amount of formaldehyde or alcohol exceeds 50 ppm, a dense deposited film cannot be obtained and sufficient gas barrier properties cannot be obtained. The amount of formaldehyde generated is preferably 40 ppm or less, particularly preferably 30 ppm or less of the mass of the sample film. The amount of alcohol generated is preferably 30 ppm or less, and particularly preferably 20 ppm or less, based on the mass of the sample film. In addition, if it is set as the vapor deposition film mentioned later, the amount of formaldehyde and alcohol which generate | occur | produce on the said conditions will further decrease.

  The formaldehyde or alcohol is generated by decomposition of the melamine compound, self-condensation reaction, or condensation reaction of the melamine compound and the polyvinyl alcohol polymer, and the amount of the formaldehyde or alcohol greatly increases as the temperature rises. Thus, at the commonly used temperatures, the total amount of formaldehyde or alcohol is even lower. Moreover, in an actual usage mode, an adhesive layer, a sealant, or the like may be laminated on the coating film in addition to the vapor deposition layer, so that it becomes formaldehyde-free and alcohol-free even during heating.

[Inorganic thin film deposition layer]
When the inorganic thin film layer is deposited on the coating layer of the above coating film, the deposited film of the present invention is obtained. This inorganic thin film layer improves the gas barrier properties. As the material of the inorganic thin film, metals such as Al, Si, Ti, Zn, Zr, Mg, Sn, Cu, and Fe, oxides of these metals, and nitriding are used. And specific examples include SiOx (x = 1.0 to 2.0), alumina, magnesia, zinc sulfide, titania, zirconia, cerium oxide, or a mixture thereof. Is done. The inorganic thin film layer may be a single layer or a laminate of two or more layers.

  The film thickness of the inorganic thin film layer is preferably 10 to 5000 mm, more preferably 50 to 2000 mm. A film thickness of less than 10 mm is not preferred because sufficient gas barrier properties may not be obtained. On the other hand, if it exceeds 5,000 mm, the corresponding effect is not achieved, the bending resistance is lowered, and the manufacturing cost is disadvantageous, which is not preferable.

  As a method for depositing the inorganic thin film layer, a known method, for example, a physical vapor deposition method such as a vacuum deposition method, a sputtering method or an ion plating method, a chemical vapor deposition method such as PECVD, or the like is employed.

  In the vacuum deposition method, the deposition material is a metal such as aluminum, silicon, titanium, magnesium, zirconium, cerium, zinc, and SiOx (x = 1.0 to 2.0), alumina, magnesia, zinc sulfide, titania, Compounds such as zirconia and mixtures thereof are used. As the heating method, resistance heating, induction heating, electron beam heating or the like is employed. Alternatively, reactive vapor deposition using oxygen, nitrogen, hydrogen, argon, carbon gas, water vapor, or the like as a reactive gas, or using means such as ozone addition or ion assist may be employed. Furthermore, a method of applying a bias to the substrate, heating or cooling, etc. may be adopted. The vapor deposition material, reaction gas, bias application, and heating / cooling can also be employed in the sputtering method and the CVD method.

  Since the thickness of the coating film and vapor deposition film of this invention is normally used with a packaging material, it is required that it is 5-50 micrometers. Desirably, the thickness of the coating film and the deposited film is 10 to 30 μm.

  A vapor deposition film containing a melamine compound, a polyvinyl alcohol polymer, and a compound having a carboxyl group as an essential component of the coating layer has a feature of high water-resistant adhesion strength. The water-resistant adhesion strength of the deposited film is preferably 6 N / 15 mm or more, more preferably 7 N / 15 mm or more, and further preferably 8 N / 15 mm or more. When the water-resistant adhesion strength is less than 6 N / 15 mm, for example, when a boil retort treatment or the like is performed after processing into a packaging bag and filling the contents, it is not preferable. In the present invention, the compatibility between the polyvinyl alcohol polymer and the melamine compound is increased by the compound having a carboxyl group, and as a result, a dense and reduced hydrophilic coating layer is formed between the inorganic thin film layer and the base film. Therefore, the vapor deposition film of the present invention exhibits good water-resistant adhesion strength.

The gas barrier vapor deposition film of the present invention is very excellent in oxygen barrier property and water vapor barrier property due to the presence of the coating layer. The oxygen permeability is 10 ml / m ² · day · MPa or less, and the water vapor permeability is 1.0 g / m ² · day or less. In addition, there is a feature that the deterioration of the barrier property is small when an external force such as bending is applied. An example of a method for evaluating the degree of deterioration of the barrier property when subjected to external force is a gelbo treatment test, but the deposited film of the present invention has a small change in gas permeability after the gelbo test, both oxygen and water vapor. The transmittance increase rate (deterioration degree) represented by the following formula 1) is 0.2 or less.

For example, the vapor deposition film of the present invention preferably satisfies the following formula 1) in terms of oxygen permeability and water vapor permeability before and after the gelbo test when the gelbo test is performed.
Formula 1) (Permeability after gelbo test-permeability before gelbo test) / permeation before gelbo test ≦ 0.2

  A film satisfying the relationship of formula 1) is excellent in bending resistance and useful. The degree of deterioration is preferably 0.15 or less, and particularly preferably 0.10 or less.

  In the gelbo test, first, about 3 μm of polyurethane adhesive was coated on the vapor deposition surface of the vapor deposition film, heat-treated at 80 ° C., and then a low density polyethylene film was heated at 80 ° C. at a nip pressure of 490 KPa. Dry laminate to obtain a gelbo test sample as a laminate film. Then, the gelbo test sample is subjected to a twisting process 50 times using a gelbo flex tester under the conditions of 20 ° C., 65% RH, 50 twists / minute. The oxygen permeability and water vapor permeability of the sample after the gelbo test and the sample (laminate film) before the gelbo test thus prepared are measured.

  Next, the preferable manufacturing method for obtaining the coating film of this invention is demonstrated. As a result of the study of the gas barrier property which is the main object of the present invention, the present inventors have found that the coating layer is mainly important and is greatly influenced by the coating property and the amount of volatile components. That is, it has been found that by taking the following means, a film having an excellent appearance and gas barrier property of the coating layer can be obtained.

1) Composition of the coating solution that forms the coating layer
a) Addition of compatibilized polymer
b) Use of temperature-dependent catalyst system
2） Coating / drying process
a) Volume and temperature of drying zone (tenter)
b) Moisture content of the coating layer before stretching
c) Rotation direction of the bar that controls the coat thickness

1) -a) Addition of compatibilized polymer In the production of the coating film of the present invention, the coating layer obtained from the melamine-based compound / polyvinyl alcohol-based polymer / carboxyl group-containing compound tends to have a phase-separated structure. Tends to be uneven. As a result, the gas barrier property is partially lowered after the inorganic thin film deposition, and the fluctuation of the gas barrier property is also increased. In addition, when the coating layer has a phase separation structure, unreacted alkyl etherified melamine compounds increase, and as a result, formaldehyde and lower alcohol components tend to remain, and gas barrier properties after deposition of inorganic thin films. Decreases.

  As a method for solving these problems, it is important to improve the compatibility of the coating layer. Therefore, it is preferable to use a compatibilizing polymer. Here, the compatibilizing polymer means a polymer having a function of enhancing the compatibility between the melamine compound and the polyvinyl alcohol polymer used. By including the compatibilizing polymer, the compatibility of each component is increased, the transparency of the coating layer is improved, and when the coating film (coating layer) is stretched, the coating film can be imparted with extensibility. As a result, a good appearance of the coating layer is ensured, and it is possible to achieve a high level of barrier properties. In addition, by including a compatibilizing polymer, the reactivity of the coating liquid is reduced, and the viscosity stability of the coating liquid is achieved. Will also improve.

  Examples of compatibilizing polymers include: ethylene alcohol-containing polyvinyl alcohol polymers; cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose; starches such as oxidized starch, etherified starch and dextrin; carbon monoxide-ethylene copolymers Polyalcohol obtained by reducing a polyketone comprising: polyvinylpyrrolidone; polyalkylene glycol such as polyethylene glycol; poly (meth) acrylic acid ester, poly (meth) acrylic acid (salt), (meth) acrylic acid ester, (meta ) (Meth) acrylic acid polymers such as copolymers having acrylic acid (salt) or the like as a monomer component; copolyesters containing polar groups such as sulfoisophthalic acid. Of these, the polyvinyl alcohol polymer containing ethylene component and hydroxyethyl cellulose are preferable.

  An ethylene component-containing polyvinyl alcohol polymer refers to a polymer in the form of a copolymerization of ethylene and vinyl alcohol in terms of chemical structural formula. In practice, ethylene is produced from ethylene and vinyl acetate. Monomer units such as components, vinyl alcohol components and vinyl acetate components are contained in the polymer. The amount of ethylene component in the polymer is preferably 1 to 50 mol%, more preferably 2 to 10 mol%. When the amount of the ethylene component is less than 1 mol%, the compatibility of the coating layer described above becomes poor and becomes opaque, and when it exceeds 50 mol%, the solubility in the coating solvent is poor and the workability is lowered.

  The amount of the compatibilizing polymer used in the present invention is preferably 1% by mass or more and 95% by mass or less, more preferably 3% by mass or more and 70% by mass, where the total amount of the polyvinyl alcohol polymer and the compatibilizing polymer is 100% by mass. % By mass or less, particularly preferably 3% by mass or more and 50% by mass or less, further particularly preferably 3% by mass or more and 35% by mass or less, and most preferably 3% by mass or more and 20% by mass or less. If the use amount of the compatibilizing polymer is less than 1% by mass, the compatibility of the coating film components is poor and the transparency is poor. In addition, the amount of unreacted melamine compounds increases, and formaldehyde and lower alcohol components tend to remain. As a result, a phenomenon in which the gas barrier property, which is the object of the present invention, is likely to occur. However, when the amount of the compatibilized polymer used exceeds 95% by mass, the film-thickness of the compatibilized polymer itself is adversely affected, and the transparency may be deteriorated.

  However, when an ethylene component-containing polyvinyl alcohol polymer is used as the compatibilizing polymer, the amount of the compatibilizing polymer used is 100% by mass of the total amount of the polyvinyl alcohol-based polymer and the ethylene component-containing polyvinyl alcohol polymer. 1 mass% or more and 90 mass% or less, More preferably, it is 1 mass% or more and 50 mass% or less. The reason for limiting the range of the amount used is the same as described above.

  In addition, when using the polyvinyl alcohol polymer containing an ethylene component as a compatibilizing polymer, the polyvinyl alcohol polymer containing an ethylene component is considered to be included in the polyvinyl alcohol polymer. That is, for example, the calculation of the usage amount of the melamine compound, the compound having a carboxyl group, and the temperature-dependent catalyst is calculated on the basis of the total amount of the polyvinyl alcohol polymer containing the ethylene component and the polyvinyl alcohol polymer. .

1) -b) Use of a temperature-dependent catalyst system In the production of the coated film of the present invention, the coating liquid for forming a coating layer containing, as essential components, a melamine compound, a polyvinyl alcohol polymer and a compound having a carboxyl group, The condensation reaction proceeds both in the coating solution and in the drying zone. If the reaction proceeds too much in the coating solution, the coating solution becomes cloudy and the viscosity increases. As a result, not only the transparency of the resulting coating film is deteriorated, but also the coating thickness varies, and the inorganic thin film The phenomenon that the gas barrier property after vapor deposition becomes insufficient occurs. On the other hand, in the drying zone, when the reactivity is low, the hydrophilicity of the coating film is high, and the water vapor barrier property that is one of the target gas barrier properties cannot be expressed. That is, it is difficult to obtain a sufficient gas barrier property by simply controlling the reaction.

  In order to solve this contradictory problem, it is considered necessary to reduce the reactivity of the coating liquid and increase the reactivity of the coating layer (dried coating film). Use of a large catalyst (in the present invention, this is called a temperature-dependent catalyst) is effective. In other words, this increases the difference between the reactivity of the coating liquid and the reactivity of the coating layer, and it is possible to realize low reactivity in the coating liquid and high reactivity in the drying zone. It becomes possible to obtain.

  The temperature-dependent catalyst is not limited as long as it has a low catalytic activity at the temperature at which the coating liquid is handled, and exhibits a remarkable catalytic activity at the temperature of the drying zone. Acid / volatile amine catalysts; inorganic metal salts such as aluminum chloride, aluminum nitrate, aluminum sulfate, zinc chloride, zinc nitrate, zinc borofluoride, magnesium chloride, magnesium borofluoride; inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid; Examples thereof include organic acids such as benzenesulfonic acid, naphthalenesulfonic acid, dodecylbenzenesulfonic acid, acetic acid, lactic acid, tartaric acid, citric acid and glycolic acid. Among these, an acid / volatile amine catalyst and magnesium chloride are preferable.

  Examples of acid / volatile amine catalysts include amine salts of compounds containing acidic groups such as carboxyl groups and sulfonic acid groups, and potential compounds that become acidic by dissociating amines and ammonium, such as ammonium salts. Can be used. Examples include amine salts of benzenesulfonic acid and ammonium salts thereof, amine salts of naphthalenesulfonic acid derivatives and ammonium salts thereof, amine salts of phosphoric acid and ammonium salts thereof, and more specifically, amine salts of dodecylbenzenesulfonic acid , Ammonium salt, amine salt of dinonylnaphthalene sulfonic acid, ammonium salt, amine salt of p-toluenesulfonic acid, ammonium salt, amine salt of phosphoric acid, ammonium dihydrogen phosphate, ammonium monohydrogen phosphate, catalyst 500 ( Mitsui Cyanamid), Catalyst 600 (same), Catalyst 4040 (same), and the like. About the ratio of an acid and a volatile amine, although this also depends on the kind of catalyst, it is normal to add 0.1-2.0 equivalent of a volatile amine with respect to an acid.

  The amount of the temperature-dependent catalyst added is usually 0.1 to 10% by mass based on the total solid content of the melamine compound, polyvinyl alcohol polymer and carboxyl group-containing compound, although it depends on the type of catalyst. Is done.

  In the present invention, a coating film having a good appearance and excellent gas barrier properties can be obtained by the synergistic effect of using the temperature-dependent catalyst and the compatibilizing polymer of 1) -a) above, for the following reason. Is guessed.

  By adding a temperature-dependent catalyst, the difference between the reactivity of the coating solution and the reactivity of the coating layer can be increased. However, if the amount of the temperature-dependent catalyst added increases, The reactivity tends to increase, and the viscosity stability of the coating liquid tends to be impaired. On the other hand, the compatibilizing polymer reduces the reactivity of the coating liquid (improves the viscosity stability of the coating liquid), further increases the compatibility of the coating layer, and consequently improves the reactivity of the coating layer. It is. Therefore, by using the compatibilizing polymer in combination with the temperature-dependent catalyst, the amount of the temperature-dependent catalyst added can be suppressed, and the balance between the reactivity of the coating solution and the reactivity of the coating layer is appropriately adjusted. It is considered a thing.

2) -a) Exhaust amount and temperature of the drying zone (tenter) In the production of the coating film of the present invention, the exhaust amount and temperature of the drying zone are also important in terms of developing gas barrier properties. By increasing the exhaust amount of the drying zone, the volatile components in the coating film are reduced and gas barrier properties are exhibited. That is, when the exhaust amount of the drying zone is low, many volatile components such as formaldehyde and lower alcohol of unreacted melamine remain in the coating film, and the inorganic thin film deposited thereon is not dense and has sufficient gas barrier properties. I can't get it. On the other hand, when the exhaust amount in the drying zone is increased, the temperature fluctuations in the drying zone tend to cause ternary reaction spots of melamine compound / polyvinyl alcohol polymer / carboxyl group-containing compound, resulting in gas barrier properties. Tends to be insufficient.

  Thus, as a result of examining means for solving these problems, it was found that sufficient gas barrier properties can be obtained by using a means for increasing the temperature of the drying zone. However, if the temperature is too high, temperature fluctuations in the film flow direction may increase, and adverse effects such as a decrease in the strength of the substrate may occur. Therefore, it is important to set an appropriate temperature.

  Specifically, by setting the exhaust amount and temperature of the drying zone to the following and performing precise control, such a harmful effect is not caused and a good gas barrier property is exhibited.

1) Exhaust amount in drying zone (m ³ / min) = coat thickness (μm) × melamine amount in coating layer (mass%) × coefficient a a: 40 to 70
2) Maximum temperature of drying zone (heat setting temperature): 220-235 ° C

  In addition, as a method for reducing temperature fluctuation, it is also possible to use a wind speed fluctuation suppression facility with an inverter attached, or use a low pressure steam of 500 KPa or less as a heat source to suppress temperature fluctuation of hot air hitting the film. It is valid. By using this method, it is possible to further increase the level of gas barrier properties, particularly by using these methods together.

2) -b) Water content of the coating layer before stretching In the coating method during film formation, it is important to adjust the moisture content of the coating layer before stretching from the viewpoint of the spreadability of the coating layer. By controlling to an appropriate amount of moisture, a coating layer that can achieve sufficient gas barrier properties can be formed. As described above, an aqueous solvent is used for the liquid to be coated, and the water content of the solvent volatilizes in the drying zone. Thereafter, the coating layer formed thereby is stretched together with the substrate. Here, if the water content immediately before stretching is too low, the temperature of the coating layer becomes too high, and the three types of reaction of the melamine compound, the polyvinyl alcohol polymer, and the compound having a carboxyl group proceed too much. As a result, the spreadability of the coating layer is poor and a coating layer with a good appearance cannot be obtained. On the other hand, if the amount of water immediately before stretching is too high, the temperature of the substrate becomes too low, and stable stretching of the substrate becomes impossible. The moisture content of the coating layer having a good appearance and a suitable coating layer capable of stably stretching the substrate is 0.5 to 2.0% by mass. Although control of these moisture amounts differs depending on the coat thickness, it is possible to control the preheating zone temperature, wind speed, passage time, zone length, temperature, setting pattern in the flow direction of the wind speed, etc. in the normal drying zone. In order to obtain a coating layer having a good appearance, it is important to gradually dry it, and it is effective to gradually increase both the temperature and the wind speed in the flow direction after coating. For example, it is preferable that the temperature of the preheating zone is 105 ° C. or less, the stretching is performed at about 110 to 130 ° C., and the final heat setting is performed at 220 to 235 ° C. as described above.

2) -c) Rotation direction of the bar for controlling the coating thickness As a method for forming the coating layer of the coating film of the present invention, the method of scraping the coating liquid with a bar and controlling the coating thickness is possible with inexpensive equipment. Often used. As a result of studying this method, it was found that the bar was appropriately rotated and the direction of rotation was important in the uniformity of the coat. In other words, by applying rotation of the bar in the same direction as the film traveling direction (rotation in the same direction at the coating portion, ie, positive rotation), it is possible to realize coatability equivalent to roll coating capable of uniform coating. I found it. The rotation speed is preferably 1/500 to 1/50 of the running speed of the film. If the running speed is less than 1/500, coat streaks tend to appear, and if it exceeds 1/50, the coating thickness fluctuates more and the gas barrier properties after inorganic thin film deposition become non-uniform.

  Note that only one of the means 1) -a) b), 2) -a) b) c) described above contributes effectively to the development of the gas barrier properties of the film and the appearance of the coating layer. In addition, by using these means in combination, a sufficient and uniform gas barrier property can be realized very efficiently.

  In the production of the coated film of the present invention, as for the production conditions other than those described above, optimum conditions may be appropriately selected and applied from the normal production conditions for the coated film.

  About the manufacturing method of the vapor deposition film of this invention, what is necessary is just to vapor-deposit the coating film obtained by the above-mentioned manufacturing method with the said vapor deposition method.

  In addition, since the coating film and vapor deposition film of this invention are normally used as a packaging material, the heat-sealable resin layer called a sealant is often formed on an inorganic thin film layer. The heat-sealable resin layer is usually formed by an extrusion lamination method or a dry lamination method. The thermoplastic polymer for forming the heat-sealable resin layer is not particularly limited as long as the sealant adhesiveness can be sufficiently expressed, such as polyethylene resins such as HDPE, LDPE, and LLDPE, PP resin, and ethylene-vinyl acetate copolymer. , Ethylene-α-olefin random copolymer, ionomer resin, and the like can be used.

  Hereinafter, the present invention will be described in detail by way of examples. The film characteristics obtained in each example were measured and evaluated by the following methods.

1) Amount of formaldehyde 1 g of a film sample that was allowed to stand for 3 hours at 25 ° C. and 65% RH was heated at 130 ° C. for 3 minutes, and the generated gas was DNPH (2,4-dinitrophenylhydrazine) under an air of 1 L / min. Derivatized with a cartridge and collected. The collected formaldehyde derivative was quantified by high performance liquid chromatography and converted into formaldehyde.

2) Alcohol amount About 10 mg of a film sample which was allowed to stand for 3 hours under conditions of 25 ° C. and 65% RH was measured by a glass insert method gas chromatography (manufactured by Shimadzu Corporation, GC-9A). The inlet temperature was 130 ° C. and the mixture was collected for 3 minutes to quantify lower alcohol (methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol).

3) Coat thickness: number of measurement points Measured by observation with a transmission electron microscope. Film samples were embedded with epoxy resin and ultrathin sections were prepared at room temperature. It was stained for 3 minutes with RuO ₄ vapor, it was observed for samples subjected to carbon deposition. Observation and photography were performed with a JEM2010 transmission electron microscope manufactured by JEOL Ltd. at an acceleration voltage of 200 KV and a direct magnification of 50000 times. The film is appropriately cut out, and the thickness is measured at a point where the length along the film width direction is equally divided into five (that is, when the film width of the sample is 0.4 m, 0.08 m, 0. The thickness of the points of 16 m, 0.24 m, 0.32 m, and 0.4 m was measured), and the average value was defined as the coat thickness (μm) of each sample.

When a methylol melamine compound is used as the melamine compound, the coat thickness can be obtained using the IR C═N absorption band of the melamine compound. Using the following calculation formula obtained from the correlation between the ATR-IR absorbance ratio and the transmission electron microscope thickness, the IR absorbance ratio was measured to obtain the coat thickness, and it was confirmed that the coat thickness was the same as described above.
Coat thickness (μm) = A1540cm ⁻¹ (absorbance of melamine) / A1340cm ⁻¹ × 0.15

4) Water contact angle It measured using the contact angle meter (DropMaster500; Kyowa Interface Science) with respect to the coating surface surface of the coating film left to stand on 25 degreeC and 65% RH conditions for 3 hours. Water used was ion exchange water. The value after 10 minutes was measured after dropping water drops of ion-exchanged water.

5) Oxygen permeability The oxygen permeability of the deposited film was adjusted for 3 hours under conditions of 23 ° C. and 85% RH, using an oxygen permeability measuring device (manufactured by Modern Controls; OX-TRAN100). It was measured. As appropriate, for the cut sample, the oxygen permeability was measured at a point where the length along the film width direction was equally divided into five, as in the case of the coat thickness, and the average value was determined as the oxygen permeability (ml / M ² · day · MPa).

6) Water vapor transmission rate The water vapor transmission rate of the vapor-deposited film was adjusted for 3 hours under conditions of 40 ° C and 90% RH, and then using a measuring device (PARMATRAN-W) manufactured by Mocon, USA. It was measured. As in the case of the coat thickness, the water vapor permeability was measured at a point where the length along the film width direction was equally divided into 5 parts, and the average value was determined as the water vapor permeability (g / M ² · day).

7) Gelbo test Gelbo treatment was performed for evaluation of bending resistance. The vapor deposition surface of the vapor deposition film was coated with about 3 μm of polyurethane adhesive (manufactured by Toyo Morton; TM590 / CAT56), heat-treated at 80 ° C., and then low density polyethylene film (manufactured by Toyobo; L6102; thickness 40 μm) was 80. Dry lamination was performed at a nip pressure of 490 KPa on a metal roll heated to 0 ° C. to form a laminate film, which was used as a sample. The gelbo treatment was evaluated using a gelbo flex tester (manufactured by Rigaku Corporation). Twist treatment was performed 50 times under the conditions of 20 ° C., 65% RH, 50 twists / minute. The oxygen permeability and water vapor permeability of the sample after gelbo treatment and the sample before gelbo treatment thus prepared were measured, and the degree of deterioration was calculated by the following equation 1).
Equation 1) Degradation level = (permeability after gelbo test−permeation before gelbo test) / permeation before gelbo test

8) Water-resistant adhesion strength The laminate film prepared in 7) was sampled in a strip shape having a width of 15 mm with the film forming flow direction as the longitudinal direction. With respect to the sample, the T-type peel strength was measured with a tensile tester (Toyo Sokki Co., Ltd .; Tensilon UTM) while continuously applying water droplets to the peeled portion at a tensile rate of 200 mm / min.

Experimental example 1
[Manufacture of coating liquid]
While stirring 39.6 kg of water, 4.86 kg of unmodified polyvinyl alcohol polymer (degree of saponification 98.5 mol%; degree of polymerization 500), polyvinyl alcohol polymer containing ethylene component (manufactured by Kuraray; EXEVAL® RS) -4105; ethylene content 5 mol%; saponification degree 98.5 mol%; polymerization degree 500) 0.54 kg was gradually charged. Next, it heated to 90 degreeC and melt | dissolved the polyvinyl alcohol polymer completely. Thereafter, the mixture was cooled to 25 ° C. to prepare a 12% aqueous solution of polyvinyl alcohol polymer (representing mass% unless otherwise indicated by mol%, hereinafter the same). Next, 45 kg of this polyvinyl alcohol polymer aqueous solution, 12.3 kg of melamine compound (Mitsui Cytec; Cymel (registered trademark) 327; 77% solution), and polyacrylic acid aqueous solution (manufactured by Nippon Shokubai; HL415) as a compound having a carboxyl group Molecular weight 10,000; 45% solution) 2.73 kg, water 31.6 kg, isopropyl alcohol 7.0 kg, phosphoric acid 20% aqueous solution 1.8 kg, monoethanolamine 20% aqueous solution 1.12 kg (phosphoric acid is a polyvinyl alcohol polymer, melamine) 2% with respect to the total amount of solids of the compound and carboxyl group-containing compound, monoethanolamine is 1/3 equivalent to phosphoric acid), 0.018 kg of polyalkylene glycol surfactant (Daiichi Kogyo Seiyaku; Neugen® EA110; HLB11; 0.1 Mixed pairs coating layer) in this order to prepare a solid concentration of 18% coating solution. In this example, melamine compound / polyvinyl alcohol polymer / compound having a carboxyl group = 60/30/10 (mass ratio).

[Manufacture of coated film]
Intrinsic viscosity 0.62 (30 ° C., phenol / tetrachloroethane = 60/40), polyethylene terephthalate (PET) containing 700 mass ppm of silica is pre-crystallized, then fully dried, and 280 using an extruder having a T die. An amorphous sheet was obtained by extruding at 0 ° C. and rapidly solidifying on a drum having a surface temperature of 40 ° C. Next, the obtained sheet was stretched 4.0 times at 100 ° C. in the longitudinal direction between the heating roll and the cooling roll. On the other hand, the coating liquid (solid content concentration 18%) was put into a temperature control tank connected to a fountain for discharging to the film surface, and controlled to 25 ° C. while stirring. A clean liquid obtained by separating foreign matters through a 30 μm pore polypropylene capsule filter was coated with the fountain on one side of the obtained uniaxially stretched film under the condition of a discharge rate of 0.028 m ³ / min. Thereafter, a smooth bar having a diameter of 14 mm was attached to the liquid surface, the coating liquid was scraped off, and coating was performed so that the coating thickness after stretching was 0.15 μm. The coating speed (film forming speed) is 150 m / min. The rotation speed of the bar related to the coating property was 60 rpm (circumferential speed 2.6 m / min) in the same direction as the film traveling direction. Next, the film was led to a drying zone (tenter), the solvent was volatilized and dried at a preheating temperature of 100 ° C., and the moisture content of the coating layer after drying was adjusted to 1.0%. Then, the film was stretched 4.0 times in the transverse direction at a temperature of 120 ° C., and heat-fixed at a temperature of 225 ° C. while relaxing in the transverse direction by 6%. The treatment time at each temperature is 3 seconds at a preheating temperature of 100 ° C., 5 seconds at a stretching temperature of 120 ° C., and 8 seconds at a heat setting treatment temperature of 225 ° C. Moreover, the wind speed of the hot air sprayed on the film at this time was set to 15 m / second in each of the preheating, stretching, and heat setting processes. Fluctuations in wind speed were controlled within ± 0.5 m / sec by attaching an inverter to the wind speed equipment. In order to obtain gas barrier properties and uniformity, the exhaust amount in the drying zone was set to 480 m ³ / min based on the following formula.
Coat thickness: 0.20 (μm) × Melamine amount in coating layer: 60 (%) × Coefficient: 40
= Displacement: 480m ³ / min

  After cooling, both edges were cut and removed, thereby continuously forming a biaxially stretched polyester film having a thickness of 12 μm over 1000 m to produce a mill roll. The obtained mill roll was slit into a width of 400 mm and a length of 1000 m, wound up on a 3-inch paper tube, and a film roll having the coating layer of the present invention was obtained.

[Manufacture of evaporated film]
Next, using this film roll, various metals or metal oxides were vapor-deposited on the coated surface side of the film under the following conditions.

a) Aluminum deposition As a deposition source, particulate aluminum having a size of about 8 to 10 mm (purity 99.9%) was used, and the film layer obtained as described above was coated with the electron beam deposition method on the coating layer surface side. An aluminum thin film was formed. An electron gun (hereinafter referred to as an EB gun) was used as a heating source, and the emission current was set to 0.5A. The film feed rate was 130 m / min, and a 50 nm thick film was formed. The pressure during vapor deposition was adjusted to 1 × 10 ⁻² Pa and the temperature of the roll for cooling the film during vapor deposition was adjusted to −10 ° C.

b) Aluminum oxide deposition As a deposition source, particulate Al ₂ O ₃ (purity 99.9%) having a size of about 3 to 5 mm is used, and an electron beam is applied to the coating layer side of the film roll obtained as described above. An aluminum oxide thin film was formed by vapor deposition. An EB gun was used as the heating source, and the emission current was 1.3A. The film feed rate was 130 m / min, and a 20 nm thick film was formed. The pressure during vapor deposition was adjusted to 1 × 10 ⁻² Pa and the temperature of the roll for cooling the film during vapor deposition was adjusted to −10 ° C.

c) Silicon oxide deposition As a deposition source, particulate Si (purity 99.99%) and SiO ₂ (purity 99.9%) having a size of about 3 to 5 mm are used, and the film roll obtained as described above is coated. A silicon oxide thin film was formed on the layer surface side by electron beam evaporation. The vapor deposition material was divided into two without being mixed. An EB gun was used as a heating source, and each of Si and SiO ₂ was heated in a time-sharing manner. Each material was heated so that the emission current of the EB gun at that time was 0.8 A and the composition ratio of Si and SiO ₂ was 1: 9. The film feed rate was 130 m / min, and a 20 nm thick film was formed. The pressure during vapor deposition was adjusted to 1 × 10 ⁻² Pa and the temperature of the roll for cooling the film during vapor deposition was adjusted to −10 ° C.

d) Composite vapor deposition Film obtained as described above using particulate SiO ₂ (purity 99.99%) and Al ₂ O ₃ (purity 99.9%) having a size of about 3 to 5 mm as a vapor deposition source. A mixed thin film of aluminum oxide and silicon dioxide was formed on the surface of the coating layer of the roll by electron beam evaporation. The vapor deposition material was divided into two without being mixed. An EB gun was used as a heating source, and each of Al ₂ O ₃ and SiO ₂ was heated in a time-sharing manner. Each material was heated so that the emission current of the EB gun at that time was 1.2 A and the composition ratio of Al ₂ O ₃ and SiO ₂ was 45:55. The film feed rate was 130 m / min, and a 20 nm thick film was formed. The pressure during vapor deposition was adjusted to 1 × 10 ⁻² Pa and the temperature of the roll for cooling the film during vapor deposition was adjusted to −10 ° C.

Experimental Examples 2-38
As shown in Tables 1 and 2, the preparation conditions of the samples were changed, and a coating film and a vapor deposition film were prepared. About these, the amount of formaldehyde, the total amount of the lower alcohol, the coating thickness of the coating film, the water contact angle, and the oxygen / water vapor permeability of the deposited film (resistance to resistance) were measured according to the methods and conditions described in the beginning of the Examples. In addition, the water-resistant adhesion strength was also measured. Experimental Examples 1 to 19 (Table 1) are examples of the present invention, and Experimental Examples 20 to 38 (Table 2) are reference examples prepared under conditions that deviate from preferred production examples and constituent materials of the present invention. Tables 3 to 5 show the evaluation results.

  According to the present invention, the coating layer appearance, oxygen barrier properties, water vapor barrier properties, flex resistance, water resistance adhesion properties are excellent, and the incineration exhaust gas does not contain dioxin and hydrogen chloride gas and is effective for environmental conservation. Can be provided economically.

Claims (7)

A coating film obtained by laminating a coating layer containing a melamine compound, a polyvinyl alcohol polymer, and a compound having a carboxyl group as essential components on a substrate made of a polymer resin composition,
The thickness of the coated film is 5 to 50 μm, and the mass of formaldehyde and alcohol generated from the coated film when heated at 130 ° C. is 50 ppm or less of the mass of the coated film sample, respectively. A covering film.   The coated film according to claim 1, wherein the compound having a carboxyl group is a (meth) acrylic acid polymer and / or a maleic acid polymer.   The coating layer has a melamine compound, a polyvinyl alcohol polymer, and a compound having a carboxyl group as a mass ratio of melamine compound / polyvinyl alcohol polymer / carboxyl group-containing compound in a range of 24 to 89/10 to 75 /. The coating film according to claim 1 or 2, wherein 1 to 50 is contained.   The coating film according to any one of claims 1 to 3, wherein the coating layer has a thickness of 0.05 to 0.50 µm.   A vapor-deposited film obtained by vapor-depositing an inorganic thin film layer on the coating layer of the coating film according to claim 1.   The vapor-deposited film according to claim 5, wherein the water-resistant adhesion strength is 6 N / 15 mm or more. The vapor-deposited film according to claim 5 or 6, wherein the oxygen permeability and the water vapor permeability before and after the gelbo test satisfy the following formula 1) when the gelbo test of the vapor-deposited film is performed.
Formula 1) (Permeability after gelbo test-permeability before gelbo test) / permeation before gelbo test ≦ 0.2