JP2006051751A - Laminate of gas barrier film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate of gas barrier films for which the conventional dry or non-solvent laminating method can be used as it is by giving consideration to the adhesive agent composition and which does not cause foaming/whitening due to the effect of moisture even if base materials having gas barrier property are mutually laminated. <P>SOLUTION: In the laminate comprising the base materials having gas barrier property or two or more layers of the base materials having gas barrier property, the laminate of gas barrier films is formed by gluing the base materials having gas barrier property together by the dry laminating method or non-solvent laminating method, wherein the adhesive for the above dry or non-solvent laminating method is the one that hardens through the reaction between a compound having an amino group, an imino group, or a protected group thereof by an aldehyde group, a ketone group or the like, and a compound having an epoxy group. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laminate used in the field of packaging of non-food products such as foods and beverages, pharmaceuticals and electronic parts, medical devices and members, electronic members themselves, etc., and particularly in the atmosphere by maintaining a high gas barrier property. The present invention relates to a gas barrier film laminate that blocks contents from oxygen and water vapor and suppresses deterioration and alteration.

  In recent years, packaging materials used in the field of non-food products such as food and beverages, pharmaceuticals, and electronic parts suppress the deterioration of contents, and retain the functions and properties of medical instruments, members, and electronic members themselves. Therefore, it is necessary to prevent the influence of oxygen or water vapor that permeates the material or other gas that alters the contents, and it is required to have gas barrier properties that block these gases.

  Therefore, as a conventional gas barrier layer, a metal foil typified by aluminum or the like, a vapor deposition film of aluminum or an inorganic oxide, a resin film such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinylidene chloride, polyacrylonitrile, or the like. A plastic film coated with a resin has been mainly used.

  Among them, some contents require a super gas barrier function, and the gas barrier materials are often combined and used together.

  However, when the substrate having excellent gas barrier properties, or the substrate having gas barrier properties at two or more locations in the same laminate using an adhesive, dry or non-solvent laminating, heating the adhesive, etc. to react and cure, Carbon dioxide gas is generated during or after processing due to the influence of moisture in the base material or the atmosphere, and it does not escape within the gas barrier base material, resulting in a foam whitening state. This is a serious problem in appearance and also causes a problem in the laminate strength between the gas barrier substrates.

  As a technique for solving such a problem, when performing dry or non-solvent lamination, a method of reacting and curing at room temperature is employed instead of heat curing the adhesive. However, not in the case of light packaging materials, but in the case of packaging materials that are heated or heat and pressure sterilized or filled with heavy objects, there is also a need to strengthen the adhesive strength in medical instruments, members, electronic members, etc. It is essential to cure for at least 2 days in a heating environment of about 40 ° C. or higher.

  Also, if the substrates can be bonded to each other by a method other than dry or non-solvent lamination, for example, an adhesive is applied on the substrate side at a low coating amount, and the resin is then extruded in a molten state and bonded. The above problem does not occur if an extrusion method or a thermal laminating method in which an adhesive resin having a polar functional group is applied between base materials and pressure-bonded with a roll heated at a high temperature is used. However, in the former extrusion method, the required quality is often not satisfied in the case of heating, heat and pressure sterilization treatment, or in the case of packaging materials that are filled with heavy objects. There are problems that the base material that can withstand the roll temperature is limited, the laminating speed is low, and the manufacturing machine is expensive.

The present invention is intended to solve the problems of the prior art. By considering the adhesive composition, the conventional dry or non-solvent laminating method can be used as it is, and substrates having gas barrier properties can be used. It aims at providing the gas barrier film laminated body characterized by not foaming whitening by the influence of a water | moisture content even when it bonds together.

Invention of Claim 1 is the laminated body in which the base material which has gas-barrier property, or the base material which has gas-barrier property contains two or more layers,
A gas barrier film laminate in which a substrate having gas barrier properties is bonded by a dry laminate method or a non-solvent laminate method,
Gas barrier film laminate, wherein the adhesive for dry or non-solvent laminate is cured by reaction of an amino group or imino group or a compound in which they are protected with an aldehyde group or a ketone group and a compound having an epoxy group Is the body.

  The invention according to claim 2 is characterized in that the dry or non-solvent laminating adhesive comprises an amino group or imino group or a compound in which they are protected with an aldehyde group or a ketone group and a carboxylic acid or carboxylic acid chloride or carboxylic acid anhydride. It is a gas barrier film laminate that is cured by this reaction.

  According to a third aspect of the present invention, the base material having gas barrier properties is a metal foil typified by aluminum, a metal vapor deposited film typified by aluminum vapor deposition, an inorganic oxide or a mixture vapor deposited film of inorganic oxides, polyvinyl acetate. Or a poly (ethylene-vinyl acetate) copolymer complete or partially saponified film or a film coated with them, a film made of polyacrylonitrile or acrylonitrile copolymer, a polyvinylidene chloride film or a coating film thereof The gas barrier film laminate according to claim 1, wherein the gas barrier film laminate is a base material.

  The invention according to claim 4 is the gas barrier film laminate according to any one of claims 1 to 3, wherein a wear-resistant protective layer and a barrier deterioration preventing layer are provided on the vapor deposition layer. is there.

  The invention according to claim 5 is characterized in that the wear-resistant protective layer and the barrier property deterioration preventing layer (overcoat layer) are composed of a water-soluble polymer and at least one metal alkoxide, a silane coupling agent, a silane monomer, and hydrolysis thereof. It consists of a thing, It is a gas barrier film laminated body of Claim 4.

  The invention according to claim 6 provides a primer layer made of acrylic polyol, isocyanate, silane coupling agent, silane monomer, etc. between the vapor deposition layer of the base material having gas barrier properties and the film forming the vapor deposition layer. It is a gas barrier film laminated body of any one of Claims 1 thru | or 5 characterized by these.

The invention of claim 7 is characterized in that the water vapor permeability of the gas barrier film laminate according to any one of claims 1 to 6 is 10 g / m ² · day · atm or less. It is.

<Action>
According to the present invention, when there are two or more base materials having gas barrier properties against oxygen, water vapor, or the like, or when two or more base materials having gas barrier properties exist in the same laminate, they are subjected to a dry or non-solvent lamination method. Thus, it is possible to provide a packaging material that does not foam white due to the influence of moisture generated in the laminated body even when heat-cured for reaction curing when bonded using an adhesive. In particular, when a transparent film imparted with a gas barrier property is used, the problem of poor appearance cannot be avoided, so the effect of the present invention can be said to be great.

  As described above, according to the present invention, when there are two or more base materials having gas barrier properties against oxygen, water vapor or the like, or when two or more base materials having gas barrier properties exist in the same laminate, they are dried. Or, when bonding by non-solvent laminating method, it is not a mechanism that cures by reaction of isocyanate group and hydroxyl group, or moisture in the environment, but protects with amino group or imino group or aldehyde group or ketone group, for example If it is cured by the reaction of the compound with an epoxy group-containing compound, carboxylic acid, carboxylic acid chloride or carboxylic anhydride, it will occur in the laminate even if it is heat-cured for reaction curing. It is possible to provide a packaging material that does not foam white due to the influence of moisture. Also, it withstood retort sterilization under high temperature and high pressure, and no influence on the gas barrier properties thereafter. In particular, when a transparent film imparted with a gas barrier property is used, the phenomenon of foaming whitening is a big problem as a poor appearance, and thus the effect of the present invention can be said to be great.

  The present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of the gas barrier film laminate of the present invention. Of course, the present invention is not limited to this, and various material configurations can be considered.

  First, in FIG. 1, 1 is a base material 1, 2 is a primer layer A, 3 is a vapor deposition layer B, 4 is a gas barrier property deterioration preventing layer C, and base materials 1 and 2 are base materials made of a plastic material. The material 1 is a primer layer A, 5 is a base material 2, 6 is a vapor deposition layer D, 7 is a base material 3, 8 and 9 are adhesive layers. The base materials 1 and 2 are base materials made of a plastic material. The base material 1 is sequentially laminated with a primer layer A, a vapor deposition layer B made of a metal or an inorganic oxide, and a gas barrier property deterioration preventing layer C. Similarly, a layer made of a metal or an inorganic oxide is deposited on the substrate 2, and a heat-sealable polyolefin substrate 3 is laminated on the opposite side of the deposited layer D. In addition to the vapor deposition layer D, a gas barrier deterioration preventing layer can be provided on the substrate 2 on the primer layer and the vapor deposition layer D as necessary. The adhesive of the present invention is applied between the layers of the substrates 1 and 2, but the adhesive used between the layers of the substrates 2 and 3 is not limited thereto.

  The base materials 1 and 2 described above are preferably made of a plastic material and transparent. For example, polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyamide films such as 6, 6-nylon, polyolefin films such as polyethylene and polypropylene, polystyrene films, polycarbonate films, polyacrylonitrile films, polyimide films, etc. An engineering plastic film or the like is used, which may be stretched or unstretched, and preferably has mechanical strength and dimensional stability. In particular, a film arbitrarily stretched in the biaxial direction among these is preferably used, and when used for a packaging material, it is biaxially stretched in consideration of gas barrier properties, filling suitability, texture, easy disposal, and price. A polyester film (PET) or a polyamide film is preferable.

  The thicknesses of the base materials 1 and 2 are not particularly limited, but in consideration of suitability as a packaging material and processability, the thickness is practically in the range of 3 to 200 μm, and generally 6 to 30 μm. It can be said that it is more preferable.

Further, various well-known additives and stabilizers such as antistatic agents, plasticizers, lubricants, antioxidants and the like may be used on the surfaces of the substrates 1 and 2 to improve adhesion. Therefore, corona treatment, plasma treatment, ozone treatment or the like may be performed as pretreatment, and further chemical treatment or solvent treatment may be performed. In particular, the plasma treatment is preferable because the adhesion between the surface of the base material and the vapor deposition layer B made of a metal or an inorganic oxide to be laminated next is strengthened.

  In addition, when the primer layer A is provided between the base material 1 and the vapor deposition layer B, a vapor deposition layer made of a metal or an inorganic oxide is uniformly formed to improve the gas barrier property, and the adhesiveness is greatly improved. When performing a retort sterilization process etc., it is preferable to provide a primer layer. The primer layer is an organic polymer obtained by a two-component reaction of an isocyanate compound with a polyol such as acrylic polyol, polyvinyl acetal, polyester polyol or polyurethane polyol, or an organic compound having a urea bond by reaction of a polyisocyanate compound and water. , Polyethyleneimine or derivatives thereof, polyolefin emulsions, polyimides, melamines, phenols, or inorganic silicas such as organically modified colloidal silica, organic silane compounds such as silane coupling agents and hydrolysates thereof, etc. Although any of them can be used as a primer agent, a combination of an acrylic polyol, an isocyanate compound and a silane coupling agent is particularly preferable. In general, it is desirable to coat so that the thickness after drying is in the range of 0.005 to 5 μm, and more preferably in the range of 0.01 to 1.0 μm. When the thickness is 0.01 μm or less, it is difficult to obtain a uniform coating film from the viewpoint of coating technique, and conversely, when it exceeds 1 μm, it is uneconomical.

  The former of the vapor deposition layer B made of a metal or an inorganic oxide includes aluminum, tin, nickel, cobalt, chromium, etc., and the latter is an oxide of silicon, aluminum, titanium, zirconium, tin, magnesium, or a mixture thereof, nitrogen. And a unit of fluoride or a composite thereof, and is formed by a vacuum process such as a vacuum deposition method, a sputtering method, or a plasma vapor deposition method. In particular, aluminum oxide is colorless and transparent, excellent in water resistance by boil / retort sterilization treatment, and can be used for a wide range of applications.

  The film thickness of the vapor deposition layer B varies depending on the material type and application used, and the film thickness of the primer layer A, but generally it is preferably in the range of 5 to 300 nm, preferably 10 to 150 nm.

Further, it is a gas barrier property deterioration preventing layer (overcoat layer) C provided on the vapor-deposited thin film layer. This is a water-soluble polymer and one or more kinds of metal alkoxides, silane coupling agents, silane monomers, and hydrolysates thereof. Alternatively, an aqueous solution containing at least one of tin chloride or a water / alcohol mixed solution is used as a main component, and this solution is applied onto a vapor-deposited thin film layer made of a metal or an inorganic oxide and then dried by heating.
The water-soluble polymer in the gas barrier deterioration preventing coating layer is preferably polyvinyl alcohol, starch, or cellulose. In particular, when polyvinyl alcohol (hereinafter referred to as PVA) is used for the coating agent of the present invention, the gas barrier property is most excellent. Because PVA is a polymer containing the most hydroxyl groups in the monomer unit, it has a very strong hydrogen bond with the remaining silanol groups. PVA as used herein is generally obtained by saponifying polyvinyl acetate, and saponification of saponification is a complete saponification in which only several percent of acetyl groups remain from so-called partially saponified PVA. Includes up to PVA. The molecular weight of PVA has various degrees of polymerization ranging from 300 to several thousand, but there is no problem in the effect even if any molecular weight is used. However, it can be said that PVA having a molecular weight having a high degree of saponification and a high degree of polymerization is generally preferable because of high water resistance.

  The thickness of the mixed coating solution after drying is not particularly limited. However, if the thickness exceeds 50 μm or more, cracks are likely to occur. Therefore, the thickness is preferably 0.01 to 50 μm.

As a gas barrier film layer forming method, a normal coating method can be used. For example, dipping method, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, silk screen, spray coating, gravure offset method and the like can be used. Using these coating methods, coating is performed on the deposited layer or directly on the substrate.

  Any method can be used for drying the gas barrier deterioration preventing coating layer by heating the gas barrier coating layer such as hot air drying, hot roll drying, high frequency induction heating, infrared irradiation, UV irradiation, etc. Two or more of these may be combined.

  By providing a heat seal layer as the base material 3, a more practical packaging material can be provided. The heat seal layer is used for an adhesive part when forming a bag-like package or the like. For example, polyethylene, linear polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer Resins such as ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, and metal cross-linked products thereof are used. The thickness is determined according to the purpose, but is generally in the range of 15 to 200 μm. Moreover, you may provide a heat seal layer on the opposite side to the vapor deposition layer of the base material 1 with the shape of a package.

  As a method for forming the heat seal layer, a dry or non-solvent laminating method in which a film made of the above-described resin is bonded with the present invention or a general adhesive, the above-mentioned resin is heated and melted and extruded into a curtain shape and bonded. Both the extrusion laminating method and the knee laminating method can be formed by a known laminating method.

  It is possible to decorate the print layer on the gas barrier deterioration-preventing coating layer or vapor-deposited layer as necessary, and the print layer or adhesive is also provided on the surface opposite to the vapor-deposited surface of the substrate 1. A plurality of resins can be laminated. In addition, the same process can be applied to the lamination of other base materials having a gas barrier property.

  Hereinafter, the gas barrier laminate of the present invention will be described with reference to specific examples.

(1) Thickness: 12 μm PET / primer layer / aluminum oxide layer / gas barrier deterioration preventing layer (2) thickness; 15 μm ONy / primer layer / silicon oxide layer (3) thickness; 70 μm CPP
(1) to (3) Interlaminar adhesive Main agent: Polyether-isophoronediamine MEK protector / curing agent; Epichlorohydrin trimethylolpropane (TMP) adduct (2) to (3) Interlaminar adhesive; Main agent Polyester polyester / curing agent; trimethylolpropane adduct of xylylene diisocyanate (XDI) and IPDI mixture

(4) Thickness: 12 μm PET / primer layer / silicon oxide layer / gas barrier deterioration preventing layer (5) Thickness: 15 μm EVOH (Kuraray Co., Ltd .; EF-CR)
(6) Thickness: 60 μm LLDPE
(4) to (5) Interlayer adhesive Main agent: Acetone protector / curing agent of polyether-xylylenediamine; Trimethylolpropane (TMP) adduct of epichlorohydrin (5) to (6) Interlayer adhesive Main agent Polyester-polyurethane system / curing agent; trimethylolpropane adduct of IPDI and XDI mixture

As a comparative example for comparing with the performance of the gas barrier laminate of the present invention obtained in Example 1, in Example 1, (1) to (2) the interlayer adhesive was changed to (2) to (3) the interlayer adhesive. The same except for the replacement.

  As a comparative example for comparison with the performance of the gas barrier laminate of the present invention obtained in Example 2, in Example 2, (4) to (5) the interlayer adhesive was changed to (5) to (6) interlayer adhesive. The same except for the replacement.

  Dry lamination was performed using the above adhesive, curing was performed at 50 ° C. for 4 days, the appearance of the obtained gas barrier film laminate was confirmed, and evaluation as various packaging materials was performed. In addition, each was subjected to a retort sterilization treatment at 121 ° C. for 30 minutes, and the oxygen permeability before and after the treatment was measured using an oxygen permeability measuring device (OXTRAN-2 / 20 manufactured by Modern Control) in 30 ° C. × 70% RH. Measured under atmosphere. The results are shown in Table 1.

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  From Table 1, the gas barrier film laminates of Examples 3 and 4 as comparative examples for comparison with the performance of the gas barrier laminate of the present invention were confirmed to be foamed and whitened between the gas barrier substrates. In the gas barrier laminate of the present invention obtained in 2, no problem was observed in appearance. In addition, no significant difference was observed in oxygen barrier properties, and a high barrier was maintained without barrier deterioration even after retort sterilization.

It is sectional drawing which shows an example of the gas barrier film laminated body of this invention.

Explanation of symbols

1 ... Base material 1
2 ... Primer layer A
3 ... deposition layer B
4 ... Gas barrier property deterioration prevention layer C
5 ... Base material 2
6 ... deposition layer D
7 ... Base material 3
8, 9 ... Adhesive layer

Claims (7)

In a laminate including two or more base materials having gas barrier properties or base materials having gas barrier properties,
A gas barrier film laminate in which a substrate having gas barrier properties is bonded by a dry laminate method or a non-solvent laminate method,
Gas barrier film laminate, wherein the adhesive for dry or non-solvent laminate is cured by reaction of an amino group or imino group or a compound in which they are protected with an aldehyde group or a ketone group and a compound having an epoxy group body.   The dry or non-solvent laminate adhesive is cured by a reaction between an amino group or imino group or a compound obtained by protecting them with an aldehyde group or a ketone group and a carboxylic acid, carboxylic acid chloride or carboxylic anhydride. A gas barrier film laminate comprising:   The base material having gas barrier properties is a metal foil typified by aluminum, a metal vapor deposited film typified by aluminum vapor deposition, a vapor deposited film of inorganic oxide or a mixture of inorganic oxides, polyvinyl acetate or poly (ethylene-vinyl acetate). ) It must be any substrate selected from complete or partially saponified films of copolymers or films coated with them, films made of polyacrylonitrile or acrylonitrile copolymers, polyvinylidene chloride films or coating films thereof. The gas barrier film laminate according to claim 1 or 2, characterized in that   The gas barrier film laminate according to any one of claims 1 to 3, wherein a wear-resistant protective layer and a barrier deterioration preventing layer are provided on the vapor deposition layer.   The wear-resistant protective layer and the barrier property deterioration preventing layer (overcoat layer) are composed of a water-soluble polymer and one or more metal alkoxides, a silane coupling agent, a silane monomer, and a hydrolyzate thereof. The gas barrier film laminate according to claim 4.   2. A primer layer comprising an acrylic polyol, an isocyanate, a silane coupling agent, a silane monomer, or the like is provided between the vapor deposition layer of the base material having gas barrier properties and the film forming the vapor deposition layer. The gas barrier film laminated body of any one of thru | or 5. The gas barrier film laminate according to any one of claims 1 to 6, wherein the water vapor permeability of the gas barrier film laminate is 10 g / m ² · day · atm or less.

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