JP4617747B2 - Method for producing transparent gas barrier laminate packaging material - Google Patents

Description

  The present invention relates to a transparent gas barrier laminate and a transparent gas barrier laminate packaging material used as packaging materials in fields requiring gas barrier properties such as foods, medical / pharmaceuticals, and electronic parts, and more specifically, high transparency, high gas barrier The present invention relates to a transparent gas barrier laminate and a transparent gas barrier laminate packaging material capable of maintaining the properties.

  In recent years, packaging materials used for packaging foods, medical / pharmaceuticals, electronic parts, etc. have been used to suppress the alteration of contents, especially the oxidation and alteration of proteins and oils and fats in food, and to maintain the taste and freshness. In addition, in pharmaceutical products that require handling under aseptic conditions, the effects of oxygen, water vapor, and other gases that alter the contents of the permeation of the packaging material in order to suppress the alteration of the active ingredient and maintain its efficacy. Therefore, it is required to have a gas barrier property to block these gases.

  Transparent plastic films used for packaging materials for foods, pharmaceuticals, electronic parts and the like are made of a material having a low gas permeability such as water vapor or oxygen in order to prevent deterioration of the packaged contents. In the case of packaging materials that require a higher degree of gas barrier properties, those obtained by bonding an aluminum foil to a film or those obtained by depositing aluminum on the surface of a film have been used. However, packaging materials using such metal foils are excellent in gas barrier properties against water vapor, oxygen, etc., but are opaque and have the disadvantage that the contents cannot be seen from the outside. There was an unsuitable aspect.

  On the other hand, polyvinylidene chloride, a film made of vinylidene chloride as a main component, and other compounds copolymerizable with this, for example, vinylidene chloride resins such as vinyl chloride, methyl acrylate, methyl methacrylate, acrylonitrile copolymer, In addition, vinylidene chloride resin-coated films obtained by coating these vinylidene chloride resins on films made of polypropylene, polyester, polyamide, and the like are also used as packaging materials having gas barrier properties. In these films, the film itself has a gas barrier property against water vapor, oxygen, and the like, and the humidity dependency is small, but there is a problem that it is difficult to realize an advanced gas barrier material (high gas barrier material). 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.

Further, a packaging film generally used as a packaging material as a gas barrier laminate by laminating or coating a polymer resin composition generally said to have relatively high gas barrier properties such as polyvinyl alcohol and ethylene-vinyl alcohol copolymer is generally used. Have been used. In addition, a metal-deposited film obtained by depositing a metal such as Al or a metal compound on an appropriate polymer resin composition (even a resin that does not have high gas barrier properties alone), and recently, silicon monoxide ( A vapor-deposited film in which a silicon oxide (SiO _x ) thin film such as SiO) or a magnesium oxide (MgO) thin film is formed on a base material made of a polymer material having transparency has been developed. These have gas barrier properties superior to those of a gas barrier material made of a polymer resin composition, have little deterioration under high humidity, and packaging films used for packaging materials have begun to be generally used.

  However, since the gas barrier laminate using the above-mentioned polymer resin composition of polyvinyl alcohol and ethylene-vinyl alcohol copolymer has a large temperature dependency and humidity dependency, the gas barrier property of the gas barrier property at high temperature or high humidity. May decrease.

  Therefore, in order to give such a laminated film a high level of gas barrier properties, the thickness of the laminated film must be increased. If the film thickness is increased, the transparency and flexibility of the laminated film are impaired. Therefore, there has been a disadvantage that properties preferable as a packaging material are lost.

Patent documents are shown below.
JP 49-41469 A Japanese Patent Publication No.53-12953, JP-A-60-27532.

  In addition, films obtained by depositing silicon oxide or magnesium oxide on polyethylene terephthalate film, polypropylene film, polyamide film, etc. have been proposed (see Patent Documents 1, 2, 3, etc.). It is not sufficient for applications that require safety.

  In addition, a film in which silicon oxide or magnesium oxide is vapor-deposited on a polyamide film is inferior to a film in which silicon oxide or magnesium oxide is vapor-deposited on a polyethylene terephthalate film or polypropylene film, and a high gas barrier property is required. It was difficult to apply to the intended use.

  Furthermore, the above-mentioned metal vapor-deposited film vapor-deposited metal or metal compound, silicon oxide thin film such as silicon monoxide (SiO), vapor-deposited film vapor-deposited magnesium oxide (MgO) thin film is an inorganic compound thin film used for gas barrier layer Is inflexible, weak against bending and bending, and has poor adhesion to the base material, so it needs to be handled with care, especially during post-processing of packaging materials such as printing, laminating, bag making, etc. There is a problem that the gas barrier property is remarkably lowered due to the generation of cracks.

  Furthermore, the conventional polyamide film such as nylon has a problem in characteristics. In particular, the essential property that the moisture absorption rate and the humidity expansion coefficient are large cannot be stably maintained due to the moisture absorption elongation or the like. When storing a problem or a film in a roll form, the flatness is deteriorated, which causes a problem in handling in vapor deposition, printing and laminating.

  The present invention has been made in order to solve the above-described problems, and has a high gas barrier property against oxygen, water vapor, etc., which is an important characteristic in packaging films for food, medical / pharmaceutical products, electronic parts, etc. An object of the present invention is to provide a transparent gas barrier laminate and a transparent gas barrier laminate packaging material having high transparency, impact resistance, and pinhole resistance that can maintain the above.

  In order to achieve the above object, that is, the invention according to claim 1 is a method for producing a transparent gas barrier laminated packaging material. 1) The stretching temperature is 70 to 120 ° C., and the stretching ratio is 2 to 4 times in both vertical and horizontal directions. A process of producing a simultaneously biaxially stretched nylon film by simultaneously biaxially stretching within the range, 2) A corona treatment is applied to one side of the simultaneously biaxially stretched nylon film, and an acrylic polyol is applied to the corona-treated surface by a gravure coating method A process of forming an anchor coat layer by applying an anchor coat liquid composed of a composite of a silane coupling agent with an isocyanate compound and drying, and 3) heating the anchor coat layer for 2 days to promote adhesion 4) A transparent gas barrier vapor deposition layer made of an inorganic oxide is formed on the anchor coat layer by a vacuum vapor deposition apparatus. 5) Applying a coating agent mainly composed of an aqueous solution or water / alcohol mixed solution containing a water-soluble polymer and one or more metal alkoxides or hydrolysates thereof on the transparent gas barrier vapor-deposited layer; A step of forming a gas barrier coating layer by heating and drying; 6) a heat seal comprising a linear low-density polyethylene film formed on the surface of the gas barrier coating layer by a dry lamination method; A transparent gas barrier laminate packaging material, comprising: a step of laminating a conductive resin film; and 7) a step of heating and curing for 4 days.

  The invention according to claim 2 is the method for producing a transparent gas barrier laminated packaging material according to claim 1, wherein the inorganic oxide is aluminum oxide, silicon oxide, magnesium oxide or a mixture thereof.

  Since the transparent gas barrier laminate of the present invention is configured as described above, it has high gas barrier properties against oxygen, water vapor, etc., and can maintain the gas barrier properties, high transparency, impact resistance, and pinhole resistance. A transparent gas barrier laminate having the following can be provided.

  Therefore, the transparent gas barrier laminate and the transparent gas barrier laminate packaging material of the present invention are suitably used as packaging materials in fields requiring gas barrier properties such as foods, medical / pharmaceutical products and electronic parts.

  Furthermore, according to the present invention, the essential properties of a polyamide film such as nylon, which has been conventionally used as a gas barrier base material, have a large moisture absorption coefficient and a high coefficient of humidity expansion, and flatness is maintained when the film is stored in a roll form. Deteriorating and can solve problems in handling in vapor deposition, printing and laminating. Furthermore, it can be used for packaging materials in a wide range of fields that require impact resistance and pinhole resistance, and its industrial utility value is great.

  Hereinafter, embodiments of a transparent gas barrier laminate and a transparent gas barrier laminate packaging material as an example of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of the configuration of the transparent gas barrier laminate of the present invention. FIG. 2 is a cross-sectional view showing an example of the configuration of the transparent gas barrier laminated packaging material of the present invention.

As shown in FIG. 1, a transparent gas barrier laminate 10 as an embodiment of the present invention includes an anchor coat layer 2 and a transparent gas barrier vapor deposition layer made of an inorganic oxide on a specific aliphatic polyamide resin film substrate 1. 3. A transparent gas barrier laminate comprising the gas barrier coating layer 4 laminated in this order.

  Moreover, as a structure which uses the transparent gas barrier laminated body of this invention practically as a packaging material, as shown in FIG. 2, the transparent gas barrier laminated packaging material 20 as one Example of this invention is a specific aliphatic polyamide resin film. On the gas barrier coating layer 4 of the transparent gas barrier laminate formed by laminating the anchor coat layer 2, the transparent gas barrier vapor deposition layer 3 made of an inorganic oxide, and the gas barrier coating layer 4 in this order on the substrate 1. A heat-sealable resin film layer 6 is laminated via an adhesive layer 5. The heat-sealable resin film layer 6 functions as an adhesive layer when practically used as a packaging material.

  The specific aliphatic polyamide resin film constituting the substrate 1 in the present invention has a moisture absorption elongation of 2% or less in the film longitudinal direction after being left for 24 hours under conditions of 20 ° C. and 65% RH immediately after the film formation. And a biaxially stretched aliphatic polyamide resin film having a dry heat shrinkage of 0.7% or less in the longitudinal direction of the film after being left for 5 minutes in an environment at 160 ° C. Although it will not specifically limit if it is an aliphatic polyamide resin film which has, As a specific example of an aliphatic polyamide resin, poly caproamide (nylon 6), poly-omega-aminoheptanoic acid (nylon 7), poly-9-aminononane Acid (nylon 9), polyundecanamide (nylon 11), polylaurin lactam (nylon 12), polyethylenediamine adipamide (nylon 2, 6), poly Tetramethylene adipamide (nylon 4,6), polyhexamethylenediadipamide (nylon 6,6), polyhexamethylene sebacamide (nylon 6,10), polyhexamethylene dodecamide (nylon 6,12), Polyoctamethylene adipamide (nylon 8,6), polydecamethylene adipamide (nylon 10,6), polydecamethylene sebamide (nylon 10,10), polydodecamethylene dodecamide (nylon 12,12) Etc. It is preferable to use a biaxially stretched film of these aliphatic polyamide resins.

  Among the above aliphatic polyamide resin films, a biaxially stretched polycaproamide (nylon 6) film is particularly desirable.

  It does not specifically limit as a method to manufacture the biaxially stretched film in this invention, A conventionally well-known method can be used. For example, simultaneous biaxial stretching by the T-die method, sequential biaxial stretching or inflation can be used for film formation, but the simultaneous biaxial stretching method is optimal from the standpoint of thickness in the film width direction and uniformity of physical properties.

  The stretching temperature for simultaneous biaxial stretching needs to be 70 to 120 ° C. When the stretching temperature is lower than 70 ° C., stretch cutting frequently occurs and the operability is deteriorated. When the stretching temperature is higher than 120 ° C., the pinhole resistance and impact resistance of the obtained stretched film are decreased.

  The biaxially stretched film is heat-treated in the heat setting zone as necessary, but care should be taken because pinhole resistance and impact resistance are reduced when heat-treated at a temperature exceeding 210 ° C.

The draw ratio can be appropriately selected within the range of 2.0 to 4.0 times in both the vertical and horizontal directions. When the draw ratio is less than 2.0 times, the obtained stretched film has low mechanical properties, and when the draw ratio exceeds 4.0 times, the film tends to break.

  For the aliphatic polyamide resin film substrate 1, for example, corona discharge treatment, ozone treatment, oxygen gas, nitrogen gas, or the like is used for low temperature plasma treatment, glow discharge treatment, chemicals, or the like. Pretreatment such as oxidation treatment or other treatment can be optionally performed.

  It is also possible to laminate a printing layer on one surface of the aliphatic polyamide resin film substrate. The printed layer is formed for practical use as a packaging material, a packaging bag, or the like. As the printing layer, for example, an ordinary gravure ink composition, an offset ink composition, a relief printing ink composition, a screen ink composition, and other ink compositions are used on the first substrate. For example, using a gravure printing method, offset printing method, letterpress printing method, silk screen printing method, or other printing method, for example, forming a desired printed pattern made up of characters, figures, patterns, symbols, etc. This can be configured. In the above, various ink compositions include, for example, as a vehicle constituting the ink composition, for example, polyolefin resins such as polyethylene resins and chlorinated polypropylene resins, poly (meth) acrylic resins, polyvinyl chloride Resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer, polystyrene resin, styrene-butadiene copolymer, vinylidene fluoride resin, polyvinyl alcohol resin, polyvinyl acetal resin, Polyvinyl butyral resin, polybutadiene resin, polyester resin, polyamide resin, alkyd resin, epoxy resin, unsaturated polyester resin, thermosetting poly (meth) acrylic resin, melamine resin, urea Resin, polyurethane resin, phenol resin, xylene resin, Inic acid resin, nitrocellulose, ethyl cellulose, acetylbutyl cellulose, cellulose resin such as ethyloxyethyl cellulose, rubber resin such as chlorinated rubber and cyclized rubber, petroleum resin, rosin, casein A natural resin such as linseed oil, fats and oils such as linseed oil and soybean oil, and a mixture of one or more resins such as others can be used. Then, one or two or more of the above-mentioned vehicles are used as a main component, and one or more of coloring agents such as dyes and pigments are added to this, and if necessary, for example, a filler, Add stabilizers, plasticizers, antioxidants, UV stabilizers and other light stabilizers, dispersants, thickeners, desiccants, lubricants, antistatic agents, crosslinking agents, etc. Ink compositions having various forms obtained by sufficiently kneading with a diluent or the like can be used.

  The anchor coat layer 2 in the present invention is an anchor coat layer made of a composite of an acrylic polyol, an isocyanate compound and a silane coupling agent.

  The composition constituting the anchor coat layer 2 will be described in more detail. The acrylic polyol as the composition constituting the anchor coat layer 2 used in the present invention is obtained by polymerizing an acrylic acid derivative monomer. Among molecular compounds or polymer compounds obtained by copolymerizing acrylic acid derivative monomers and other monomers, those having a hydroxyl group at the terminal and reacted with the isocyanate group of the isocyanate compound added later . Among these, those obtained by polymerizing acrylic acid derivative monomers such as ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate alone, and acrylic polyols obtained by copolymerizing with other monomers such as styrene are preferably used. In consideration of the reactivity with the isocyanate compound, the hydroxyl value is preferably between 5 and 200 (KOHmg / g).

  The isocyanate compound as a composition constituting the anchor coat layer 2 used in the present invention is formed of the base (1) and the transparent gas barrier vapor deposition layer 3 made of an inorganic oxide by a urethane bond formed by reaction with an acrylic polyol. It is added to improve the adhesion, and mainly acts as a crosslinking agent or a curing agent. To achieve this, the isocyanate compounds include aromatic tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), aliphatic xylene diisocyanate (XDI), hexadiene isocyanate (HMDI), and isophorone diisocyanate (IPDI). Monomers such as these and their polymers and derivatives are used. These are used alone or as a mixture.

  The blending ratio of the acrylic polyol and the isocyanate compound is not particularly limited. However, if the isocyanate compound is too small, the curing may be poor, and if it is too much, blocking or the like occurs, resulting in processing problems. There is. Therefore, as a blending ratio of the acrylic polyol and the insocyanate compound, it is preferable that the isocyanate group derived from the isocyanate compound is 50 times or less of the hydroxyl group derived from the acrylic polyol. Particularly preferred is a case where an isocyanate group and a hydroxyl group are blended in equal amounts. As a mixing method, a known method can be used and is not particularly limited.

  Moreover, the silane coupling agent as a composition which comprises the anchor coat layer 2 used by this invention can use the silane coupling agent containing arbitrary organic functional groups, for example, ethyl trimethoxysilane, vinyl Silane coupling such as trimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane One type or two or more types of agents or hydrolysates thereof can be used.

  Further, among these silane coupling agents, those having a functional group that reacts with a hydroxyl group of an acrylic polyol or an isocyanate group of an isocyanate compound are particularly preferable. For example, those containing an isocyanate group such as γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)- Those containing amino groups such as γ-aminopropyltriethoxysilane, γ-phenylaminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Such as those containing an epoxy group, etc., and these can be used alone or in a mixture of two or more. These silane coupling agents contain a functional group in which an organic functional group present at one end exhibits an interaction in a composite composed of an acrylic polyol and an isocyanate compound, or reacts with a hydroxyl group of an acrylic polyol or an isocyanate group of an isocyanate compound. By providing a covalent bond by using a silane coupling agent, a stronger primer layer is formed, and the silanol group generated by hydrolysis of the alkoxy group at the other end is a metal in the inorganic oxide or an inorganic oxide. It exhibits high adhesion with inorganic oxides by strong interaction with a highly active hydroxyl group or the like on the surface, and the desired physical properties can be obtained. Therefore, you may use what hydrolyzed the said silane coupling agent with the metal alkoxide. Further, even if the alkoxy group of the silane coupling agent is a chloro group, an acetoxy group, etc., there is no problem, and these alkoxy groups, chloro groups, acetoxy groups, etc. are hydrolyzed to form silanol groups. If present, it can be used in this composite.

  The mixing ratio of the acrylic polyol and the silane coupling agent is preferably in the range of 1/1 to 100/1 by weight, more preferably in the range of 2/1 to 50/1.

  The dissolving and diluting solvent is not particularly limited as long as it can be dissolved and diluted. For example, esters such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as methyl ethyl ketone, A mixture of aromatic hydrocarbons such as toluene and xylene alone and arbitrarily can be used. However, since an aqueous solution such as hydrochloric acid or acetic acid may be used to hydrolyze the silane coupling agent, it is necessary to use a solvent in which isopropyl alcohol or the like and ethyl acetate that is a polar solvent are arbitrarily mixed as a co-solvent. More preferred.

In addition, it is possible to add a reaction catalyst in order to promote the reaction when the silane coupling agent is blended. Examples of the catalyst to be added include tin compounds such as tin chloride (SnCl ₂ , SnCl ₄ ), tin oxychloride (SnOHCl, Sn (OH) ₂ Cl ₂ ), and tin alkoxide from the viewpoint of reactivity and polymerization stability. It is possible to use. These catalysts may be added directly at the time of blending, or may be added after being dissolved in a solvent such as methanol.

  As a method for preparing a primer solution for forming a coating film of the composition in the present invention, a composite solution in which an acrylic polyol, an isocyanate compound, and a silane coupling agent are mixed in an arbitrary mixing ratio is manufactured, and the substrate ( It is formed by coating 1). As a method for producing the composition solution, a silane coupling agent and an acrylic polyol are mixed, a solvent and a diluent are added, diluted to an arbitrary concentration, and then mixed with an isocyanate compound, or a composite solution is prepared in advance. A method in which a silane coupling agent is mixed in a solvent and then mixed with an acrylic polyol is added to a solvent and a diluent, diluted to an arbitrary concentration, and then an isocyanate compound is added to prepare a composite solution. is there.

  Various additives such as tertiary amines, imidazole derivatives, carboxylic acid metal salt compounds, quaternary ammonium salts, quaternary phosphonium salts and other curing accelerators, phenolic, sulfur-based, phosphite-based, etc. These antioxidants, leveling agents, flow regulators, catalysts, crosslinking reaction accelerators, fillers, and the like can be added as necessary.

  The thickness of the anchor coat layer 2 is not particularly limited as long as a uniform coating film can be formed. However, the dry film thickness is generally preferably in the range of 0.01 to 2 μm. When the thickness is less than 0.01 μm, it is difficult to obtain a uniform coating film, and the adhesion may be lowered. On the other hand, if the thickness exceeds 2 μm, the coating film cannot be kept flexible because it is thick, and the coating film may be cracked due to external factors. The thickness of the anchor coat layer 2 is particularly preferably in the range of 0.05 to 0.5 μm.

  As a method for forming the anchor coat layer 2, for example, a known printing method such as an offset printing method, a gravure printing method, or a silk screen printing method, or a known coating method such as a roll coating, a knife edge coating, or a gravure coating may be used. it can. As drying conditions, generally used conditions are employed.

  In the present invention, the transparent gas barrier vapor-deposited layer 3 made of an inorganic oxide that forms a gas barrier layer in the present invention is composed of an aluminum oxide, silicon oxide, tin oxide, magnesium oxide, or those transparent gas barrier vapor-deposited layers 3 made of an inorganic oxide. Any layer may be used as long as it is made of a vapor-deposited film of an inorganic oxide such as a mixture and has transparency and gas barrier properties such as oxygen and water vapor. Considering various sterilization resistances, it is more preferable to use aluminum oxide and silicon oxide among these. However, the transparent gas barrier vapor deposition layer 3 of the present invention is not limited to the above-described inorganic oxide, and any material that meets the above conditions can be used.

  The optimum thickness of the transparent gas barrier vapor-deposited layer 3 varies depending on the type and configuration of the inorganic oxide used, but is generally in the range of 5 to 300 nm, and the value is appropriately selected. However, if the film thickness is less than 5 nm, a uniform film may not be obtained or the film thickness may not be sufficient, and the function as a gas barrier material may not be sufficiently achieved. Further, when the film thickness exceeds 300 nm, the thin film cannot be kept flexible, and there is a problem because the thin film may be cracked due to external factors such as bending and pulling after the film formation. More preferably, it exists in the range of 10-150 nm.

There are various methods for forming the transparent gas barrier vapor-deposited layer 3 made of an inorganic oxide on a plastic substrate, and it can be formed by a normal vacuum vapor deposition method. Other thin film forming methods such as sputtering, ion plating, and plasma vapor deposition (CVD)
Or the like can be used. However, considering productivity, the vacuum deposition method is the best at present. As a heating means of the vacuum evaporation method, it is preferable to use any one of an electron beam heating method, a resistance heating method, and an induction heating method, but the electron beam heating method should be used in consideration of the wide selection of evaporation materials. Is more preferable. In order to improve the adhesion between the transparent gas barrier vapor-deposited layer 3 and the substrate (1) and the denseness of the transparent gas barrier vapor-deposited layer 3, it is possible to perform vapor deposition using a plasma assist method or an ion beam assist method. It is. In order to increase the transparency of the deposited film, it is possible to use reactive deposition in which various gases such as oxygen are blown during the deposition.

  Next, the gas barrier coating layer 4 that forms the gas barrier layer in the present invention will be described. The gas barrier coating layer 4 is formed using a coating agent mainly composed of an aqueous solution or water / alcohol mixed solution containing a water-soluble polymer and one or more metal alkoxides or hydrolysates thereof. For example, a solution obtained by mixing a water-soluble polymer dissolved in an aqueous (water or water / alcohol mixed) solvent with a metal alkoxide directly or previously hydrolyzed is used as a solution. This solution is formed by coating the transparent gas barrier vapor-deposited layer 3 made of an inorganic oxide, which is the first gas barrier layer, and then drying by heating. Each component contained in the coating agent will be described in more detail.

  Examples of the water-soluble polymer used as a coating agent for forming the gas barrier coating layer 4 in the present invention include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, and sodium alginate. In particular, when polyvinyl alcohol (hereinafter abbreviated as PVA) is used for the coating agent of the present invention, the gas barrier property is most excellent, which is preferable. PVA here is generally obtained by saponifying polyvinyl acetate. As PVA, for example, complete PVA in which only several percent of acetic acid groups remain can be used from so-called partially saponified PVA in which several tens percent of acetic acid groups remain, and other types may be used. .

The metal alkoxide is a compound represented by a general formula, M (OR) _n (M: metal such as Si, Ti, Al, Zr, or alkyl group such as R: CH ₃ , C ₂ H ₅ ). Specific examples include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] and triisopropoxyaluminum [Al (O-2′-C ₃ H ₇ ) ₃ ], among which tetraethoxysilane and triisopropoxy. Aluminum is preferable because it is relatively stable in an aqueous solvent after hydrolysis.

  It is also possible to add known additives such as isocyanate compounds, silane coupling agents, or dispersants, stabilizers, viscosity modifiers, and colorants to the solution as long as the gas barrier properties are not impaired. is there.

  As a coating method of the coating agent for forming the gas barrier film layer 4, conventionally known methods such as a dipping method, a roll coating method, a screen printing method, a spray method, a gravure printing method and the like can be used.

  The optimum thickness of the gas barrier coating layer 4 varies depending on the type of coating agent, the processing machine, and the processing conditions, and is not particularly limited. However, when the thickness after drying is 0.01 μm or less, a uniform coating film cannot be obtained, and sufficient gas barrier properties may not be obtained. On the other hand, when the thickness exceeds 50 μm, cracks are likely to occur in the film, which may be a problem. It is preferably in the range of 0.01 to 50 μm, more preferably in the range of 0.1 to 10 μm.

As the heat-sealable resin film 7 in the present invention, the adhesive thermoplastic resin that can be heat-sealed may be any one that can be extruded and can be melted by heat and fused to each other. For example, low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene- Acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, methyl pentene polymer, polyolefin resin such as polyethylene or polypropylene, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumar Acids modified with unsaturated carboxylic acids such as formic acid, itaconic acid, etc. Sex polyolefin resins, polyvinyl acetate resins, polyester resins other such resins can be used.

  A transparent gas barrier laminate comprising an anchor coat layer 2, a transparent gas barrier vapor deposition layer 3 made of an inorganic oxide, and a gas barrier coating layer 4 sequentially laminated on a specific aliphatic polyamide resin film substrate 1 in the present invention. A method for laminating the heat-sealable resin film layer 7 on the gas barrier coating layer 4 of the body is not particularly limited, but a laminating method by a dry lamination method is preferable.

As the dry lamination adhesive, any two-component curable urethane adhesive can be used. For example, one-component or two-component curable vinyl type, (meth) acrylic type, polyamide type , Polyester-based, polyether-based, polyurethane-based, and epoxy-based adhesives can be used. Examples of the coating method for the above-mentioned adhesive include direct gravure roll coating method, gravure roll coating method, kiss coating method, reverse roll coating method, Fonten method, and transfer method. The coating can be performed by a roll coating method or the like, and the coating amount is about 0.1 to 10 g / m ² (dry state), more preferably 1 to 5 g / m ^2. (Dry state) is desirable. The coating amount at the time of drying is preferably about 1.5 to 3.5 g / m ² from the viewpoint of adhesive strength.

  Examples of the present invention will be specifically described below.

  As a biaxially stretched nylon film, the film has a moisture absorption elongation ratio of 1.50% in the longitudinal direction of the film after standing for 24 hours under the condition of 20 ° C. and 65% RH immediately after the film formation, and after standing for 5 minutes in an environment of 160 ° C. An anchor shown below by a gravure coating method on a corona-treated surface using a single-sided corona-treated nylon film having a thickness of 15 μm and a dry heat shrinkage of 0.30% in the longitudinal direction. The coating liquid was applied and dried, and an anchor coat layer having a thickness of 0.1 μm after drying was laminated. Thereafter, curing was performed at 50 ° C. for 2 days to promote adhesion of the anchor coat layer.

  Subsequently, a transparent gas barrier vapor deposition layer made of aluminum oxide having a thickness of 15 nm was laminated on the surface of the anchor coat layer of the biaxially stretched nylon film on which the anchor coat layer was laminated, by a vacuum vapor deposition apparatus using an electronic heating wire method.

  Furthermore, on the transparent gas barrier vapor-deposited layer, a gas barrier coating liquid having the composition shown below was applied by a gravure coating method and dried to prepare a transparent gas barrier laminate of the present invention in which a gas barrier coating layer was laminated. .

Subsequently, an adhesive layer having a coating amount of 3.5 g / m ² was formed on the gas barrier coating layer surface of the transparent gas barrier laminate by a dry lamination method using a polyurethane adhesive, and a thickness of 50 μm was formed thereon. A heat-sealable resin film made of a linear low-density polyethylene film was laminated and cured at 40 ° C. for 4 days to prepare the transparent gas barrier laminated packaging material of the present invention.

<Adjustment of anchor coating solution>
Isocyanate resin (solid content 50% by weight) with respect to 7g of solution (solid content 20% by weight) prepared by diluting solvent by mixing and stirring 0.6g of isocyanate propyltrimethylsilane with acrylic polyol 6g (solid content 50% by weight) 1.5 g and a diluting solvent were added and stirred for 30 minutes to adjust the solid content to 2% by weight to prepare an anchor coat solution.

<Adjustment of gas barrier coating liquid>
Add 89.6 g of hydrochloric acid (0.1N) to 10.4 g of tetraethoxysilane, and mix the hydrolyzed solution with a solid content of 3% by weight (SiO ₂ equivalent) and 30% by weight of polyvinyl alcohol and 3 wt% of polyvinyl alcohol. Thus, a gas barrier coating solution was prepared.

<Reference Example 1>
In Example 1, as a biaxially stretched nylon film, the film has a moisture absorption elongation rate of 2.00% in the longitudinal direction of the film after being left for 24 hours under the condition of 20 ° C. and 65% RH immediately after the film formation, and in an environment of 160 ° C. 5 The transparent gas barrier laminate and the transparent gas barrier of the present invention were the same as in Example 1 except that a successively biaxially stretched nylon film having a thickness of 15 μm and a dry heat shrinkage of 0.30% in the film longitudinal direction after standing was used. A laminated packaging material was prepared.

<Reference Example 2>
In order to compare with the performance of the transparent gas barrier laminate of the present invention, in Example 1, as a biaxially stretched nylon film, the moisture absorption elongation in the longitudinal direction of the film after standing for 24 hours at 20 ° C. and 65% RH immediately after film formation Except for using a successively biaxially stretched nylon film having a thickness of 15 μm and a rate of dry heat shrinkage of 1.30% in the film longitudinal direction after being left for 5 minutes in an environment of 160 ° C. at a rate of 3.00% As in Example 1, a transparent gas barrier laminate as a comparative example was prepared.

The transparent gas barrier laminates obtained in Example 1 and Reference Examples 1 and 2 were measured for oxygen permeability based on the following evaluation method to evaluate gas barrier properties. The evaluation results are shown in Table 1.

<Measurement of oxygen permeability>
Based on the JIS K-7126B method, the measurement was performed at 25 ° C. and 50% RH using an OXTRAN 2/20 manufactured by Modern Control.

表１には、各々の実施例についての酸素透過率を記す。

Table 1 shows the oxygen permeability for each example.

From Table 1, a transparent gas barrier layered product of the present invention obtained in Example 1, an aliphatic polyamide as a resin film, the film longitudinal hygroscopic elongation 24 hours after standing under the condition of RH 20 ° C. 65% immediately after the film formation A specific biaxially stretched nylon film having a rate of 2% or less and a dry heat shrinkage of 0.7% or less in the longitudinal direction of the film after standing for 5 minutes in an environment of 160 ° C. is used as a base material Therefore, it is possible to solve the problem that the gas barrier property is excellent due to excellent oxygen gas barrier property and the conventional gas barrier property due to hygroscopic elongation, and the gas barrier property can be stably maintained.

On the other hand, the transparent gas barrier laminate obtained in Reference Example 2 as a comparative example for comparison with the performance of the transparent gas barrier laminate of the present invention is 24 hours under conditions of 20 ° C. and 65% RH immediately after film formation. A biaxial film that does not satisfy the performance of the film having a moisture absorption elongation of 2% or less after standing and a film having a dry heat shrinkage of 0.7% or less after standing in an environment of 160 ° C. for 5 minutes. Since the stretched nylon film was used as the base material, the oxygen permeability was large, the oxygen barrier property was inferior, and a stable gas barrier property was not obtained.

Further, the transparent gas barrier laminated packaging material of the present invention obtained in Example 1, a conventional, biaxially oriented nylon films, the essential nature of the nylon film of a large water absorption and moisture swelling coefficient, a roll of film The problem of poor flatness when used in storage, and difficulties in processing suitability such as vapor deposition, printing and laminating have been solved. However, the transparent gas barrier laminate packaging material obtained in Reference Example 2 has difficulty in processability such as vapor deposition, printing, and lamination.

It is sectional drawing which shows an example of a structure of the transparent gas barrier laminated body of this invention. It is sectional drawing which shows an example of a structure of the transparent gas barrier laminated packaging material using the transparent gas barrier laminated body of this invention.

1 ... Base material (specific aliphatic polyamide resin film)
DESCRIPTION OF SYMBOLS 2 ... Anchor coat layer 3 ... Transparent gas-barrier vapor deposition layer 4 which consists of inorganic oxides ... Gas-barrier coating layer 5 ... Adhesive layer 6 ... Heat-sealable resin film 10 ... Transparent Gas barrier laminate 20 ... Transparent gas barrier laminate packaging material

Claims (2)

In the method for producing a transparent gas barrier laminated packaging material ,
1) 70 to 120 ° C. The stretching temperature, process for producing the simultaneous biaxial stretching nylon film by simultaneous biaxial stretching in the range 4 times the draw ratio with vertical and horizontal directions from the two times,
2) After applying a corona treatment to one side of the simultaneous biaxially stretched nylon film , and applying an anchor coating solution composed of a composite of an acrylic polyol, an isocyanate compound and a silane coupling agent to the corona-treated surface by a gravure coating method. Drying to form an anchor coat layer ;
3) heating the anchor coat layer and curing for 2 days to promote adhesion;
4) A step of forming a transparent gas barrier vapor deposition layer made of an inorganic oxide on the anchor coat layer by a vacuum vapor deposition device ;
5) Applying a coating agent mainly composed of an aqueous solution or water / alcohol mixed solution containing a water-soluble polymer and one or more kinds of metal alkoxides or hydrolysates thereof on the transparent gas barrier vapor-deposited layer, and drying by heating. And forming a gas barrier coating layer,
6) A step of forming an adhesive layer on the gas barrier coating layer surface by a dry lamination method and laminating a heat-sealable resin film made of a linear low-density polyethylene film thereon,
7) Next heating and curing for 4 days,
A method for producing a transparent gas barrier laminated packaging material , comprising: 2. The method for producing a transparent gas barrier laminated packaging material according to claim 1, wherein the inorganic oxide is aluminum oxide, silicon oxide, magnesium oxide or a mixture thereof.

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