JP4225032B2 - Gas barrier film laminate having heat treatment resistance - Google Patents

Description

【００６５】
【発明の効果】
本発明の高温処理耐性を有するガスバリアフィルム積層体は、以上のような構成であるので、優れたガスバリア性を発現する。また、この積層体はガスバリア性が高く、かつ硬い被膜を有しているが、ガラス転移温度が低く柔軟性に優れた二液硬化型ポリウレタン系接着剤からなる接着層が介在しているため、他のフィルムと貼り合わせて包装材料を設計する場合において、接着剤の柔軟性に追随してガスバリア性被膜層が変形できるために、クラック等が起こりにくく、加熱殺菌等の加熱処理が行われた後も良好なガスバリア性を維持することが可能である。
従って、この高温処理耐性を有するガスバリアフィルム積層体は、食品及びレトルト食品、医薬品や電子部材等の非食品等の包装においてその実用上の効果がおおいに期待される。
【図面の簡単な説明】
【図１】本発明の加熱処理耐性を有するガスバリアフィルム積層体の断面模式図である。
【図２】本発明の加熱処理耐性を有するガスバリアフィルム積層体を用いた包装材料の断面模式図である。
【符号の説明】
１…基材
２…プライマー層
３…無機酸化物からなる蒸着薄膜層
４…ガスバリア性被膜層
５…二液硬化型ポリウレタン系接着剤からなる接着層
６…シーラント層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas barrier film laminate having heat treatment resistance applied to packaging materials used for packaging foods, non-foods, pharmaceuticals, etc., and particularly even when subjected to high temperature heat treatment in boil sterilization, retort sterilization, etc. It is related with the gas barrier film laminated body which has heat processing tolerance characterized by the property not falling.
[0002]
[Prior art]
In recent years, packaging materials used for packaging foods, non-foods, pharmaceuticals, etc. have altered the contents of oxygen, water vapor, and other contents that permeate the packaging materials in order to suppress the alteration of the contents and retain their functions and properties. It is necessary to prevent the influence of the gas to be generated, and it is required to have a gas barrier property and the like for blocking these. Therefore, conventionally, a packaging material using a metal foil made of aluminum or the like, which is less affected by temperature, humidity and the like, as a gas barrier layer has been generally used.
[0003]
However, the packaging material comprising a part of the metal foil layer made of aluminum or the like has high gas barrier properties with little influence of temperature, humidity, etc., but the contents cannot be confirmed through this, In addition, when discarded after use, it must be treated as an incombustible material, and further, there is a problem that the metal detector cannot be used for inspection.
[0004]
Therefore, as a packaging material that overcomes these drawbacks, a film in which a vapor deposition film of an inorganic oxide such as silicon oxide or aluminum oxide is formed on a polymer film by thin film forming means such as vacuum vapor deposition or sputtering has been developed. (For example, Patent Document 1 and Patent Document 2). These vapor-deposited films are known to have transparency and gas barrier properties such as oxygen and water vapor, and have both transparency and gas barrier properties that cannot be obtained with a packaging material having metal foil or the like. It is preferably used.
[0005]
Furthermore, as a gas barrier film obtained by further imparting post-processing suitability to the above-described deposited film, a water-soluble polymer having a hydroxyl group and one or more metal alkoxides are formed as a second layer on the inorganic oxide deposited film. Alternatively, a gas barrier film is also proposed in which a gas barrier film formed by applying a coating agent mainly composed of a metal alkoxide hydrolyzate or an aqueous solution containing at least one of tin chloride or a water / alcohol mixed solution and drying by heating is proposed. (Patent Document 3).
[0006]
The gas barrier film layer, which is the second layer of the gas barrier film, is composed of a metal alkoxide hydrolyzate and a water-soluble polymer, so that it is a hard film. However, when a packaging bag is produced using such a film as a packaging material, if the packaging bag is subjected to heat treatment such as boil sterilization or retort sterilization, the packaging bag (packaging) is affected by the pressure at that time. The material) expands and deforms, but the hard gas barrier coating layer of the gas barrier film is difficult to follow the deformation of the packaging bag (packaging material), so that cracks and the like are generated, causing the gas barrier property to deteriorate.
[0007]
When a gas barrier film is used as a part of a packaging material, a laminated structure is often formed by dry lamination in which the gas barrier film and another layer are bonded using an adhesive. In this case, a packaging material using a gas barrier film having a hard coating layer as described above expands, deforms, cracks, etc. when subjected to heat treatment such as boil sterilization or heat sterilization in the course of use. In such a case, if a flexible adhesive that can cope with the deformation of the packaging material due to heating is used, the hard coating layer can be deformed following the adhesive, thus preventing a decrease in gas barrier properties after heating. Is possible. However, no such gas barrier laminate or packaging material has been found so far.
[0008]
[Patent Document 1]
U.S. Pat. No. 3,442,686
[Patent Document 2]
Japanese Patent Publication No.63-28017
[Patent Document 3]
Japanese Patent Laid-Open No. 7-164591
[0009]
[Problems to be solved by the invention]
The present invention has been made to solve the above-mentioned problems, and the problem is that the gas barrier property is excellent, and heat treatment is performed when used as a packaging material by being bonded to another film. The present invention provides a gas barrier film laminate having heat treatment resistance that does not cause cracks or the like in some gas barrier coating layers even when exposed to high temperatures, and does not deteriorate the original gas barrier properties. .
[0010]
[Means for Solving the Problems]
  In order to solve the above problems, the invention according to claim 1 has heat treatment resistance in which at least a coating layer formed by sequentially laminating the following four layers is provided on at least one surface of a base material made of a plastic material. A gas barrier film laminate comprising an adhesive layer comprising the following two-component curable polyurethane adhesiveThe main component of the two-component curable polyurethane adhesive is a polyester polyester polyol, the curing agent having an isocyanate group (polyisocyanate) is an adduct of isophorone diisocyanate (IPDI), and the adhesive layerIt is a gas barrier film laminated body which has the heat processing tolerance characterized by the glass transition temperature of the cured film of this being the range of 5-20 degreeC.
(1) A primer layer comprising a composite of an acrylic polyol, an isocyanate compound and a silane coupling agent.
(2) A deposited thin film layer made of an inorganic oxide.
(3) A gas barrier coating layer comprising a coating agent mainly comprising an aqueous solution or a water / alcohol mixed solution containing a water-soluble polymer and one or more metal alkoxides or hydrolysates thereof. (4) An adhesive layer made of a two-component curable polyurethane adhesive.
[0012]
  MaClaim2The described invention is claimed.1The gas barrier film laminate having heat sterilization resistance described above is characterized in that the silane coupling agent has an organic functional group that reacts with at least one of a hydroxyl group of an acrylic polyol or an isocyanate group of an isocyanate compound.
[0013]
  Furthermore, the claims3The described invention is claimed.2The gas barrier film laminate having the heat sterilization resistance described above is characterized in that the organic functional group contained in the silane coupling agent is an isocyanate group, an epoxy group, or an amino group.
[0014]
  Furthermore, the claims4The invention described in claim 1 to claim 13The gas barrier film laminate having the heat sterilization resistance according to any one of the above, wherein the inorganic oxide is aluminum oxide, silicon oxide, or a mixture thereof.
[0015]
  Furthermore, the claims5The invention described in claim 1 to claim 14The gas barrier film laminate having heat sterilization resistance according to any one of the above, wherein the metal alkoxide is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof.
[0016]
  Furthermore, the claims6The invention described in claim 1 to claim 15The gas barrier film laminate having heat sterilization resistance according to any one of the above, wherein the water-soluble polymer is polyvinyl alcohol.
[0017]
  And claims7The invention described in claim 1 to claim 16In the gas barrier film laminate having the heat sterilization resistance according to any one of the above, one or more of a printed layer, an intervening film, and a sealant layer are provided on the coating layer side.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described with reference to an embodiment thereof.
FIG. 1 is a schematic cross-sectional view showing an embodiment of a gas barrier film laminate having heat sterilization resistance according to the present invention. The substrate (1) in FIG. 1 is a film substrate made of a plastic material, and on at least one surface thereof, a primer layer (2) made of a composite comprising an acrylic polyol, an isocyanate compound and a silane coupling agent, At least a coating layer formed by sequentially laminating a vapor-deposited thin film layer (3) made of an inorganic oxide, a gas barrier coating layer (4), and an adhesive layer (5) made of a two-component curable polyurethane adhesive is provided.
[0019]
The base material (1) described above is a film base material made of a plastic material, and is preferably a transparent film base material if possible in order to make use of the transparency of the vapor-deposited thin film layer (3) described later. Examples of the substrate (1) include polyester films made of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin films made of polyethylene, polypropylene, etc., polystyrene films, polyamide films, polycarbonate films, polyacrylic. A nitrile film, a polyimide film, etc. are mentioned. The substrate (1) preferably has mechanical strength and dimensional stability, and may be either stretched or unstretched, but a polyethylene terephthalate film or polyamide film arbitrarily stretched in the biaxial direction is preferably used. . In addition, on the surface opposite to the surface on which the vapor-deposited thin film layer (3) of the substrate (1) is provided, various known additives and stabilizers such as an antistatic agent, an ultraviolet ray preventing agent, a plasticizer, a lubricant, etc. A thin film made of may be applied. In addition, in order to improve the adhesion with the thin film, the thin film forming surface side of the substrate is treated by any method such as corona treatment, low temperature plasma treatment, ion bombard treatment, chemical treatment, solvent treatment, etc. Also good.
[0020]
The thickness of the substrate (1) is not particularly limited, and is not only limited to a single layer in consideration of suitability as a packaging material, but also has a multilayer configuration in which films having different properties are laminated. Also good. In view of workability when forming the primer layer (2), the vapor-deposited thin film layer (3) made of an inorganic oxide, and the gas barrier coating layer (4), a practical range of 3 to 200 μm is preferable. In particular, the thickness is more preferably 6 to 30 μm.
[0021]
Further, a thin film may be formed on the surface of the substrate (1) using various known additives and stabilizers such as antistatic agents, plasticizers, lubricants, antioxidants, etc. In order to improve the adhesion of the thin film, corona treatment, plasma treatment, ozone treatment, chemical treatment, and solvent treatment may be performed. Among these treatments, the plasma treatment is particularly preferable in order to strengthen the adhesion between the surface of the substrate (1) and the deposited thin film layer (3) made of an inorganic compound to be laminated next.
[0022]
On the other hand, the primer layer (2) is provided on the base material (1) made of a plastic material, and improves the adhesion between the base material (1) and the vapor-deposited thin film layer (3) made of an inorganic oxide. It is a layer provided so that a vapor deposition thin film layer (3) may not peel, when various heat processings, such as boil sterilization and retort sterilization, are made.
[0023]
This primer layer (2) consists of a composite of an acrylic polyol, an isocyanate compound and a silane coupling agent.
[0024]
The acrylic polyol is a polymer compound obtained by polymerizing an acrylic acid derivative monomer, or a polymer compound obtained by copolymerizing an acrylic acid derivative monomer and other monomers, and has a hydroxyl group at the terminal, It reacts with the isocyanate group of the isocyanate compound added later. Among them, 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 reactivity with the isocyanate compound, the hydroxyl value is preferably between 5 and 200 (KOHmg / g).
[0025]
Moreover, an isocyanate compound is added in order to improve adhesiveness with the base material (1) and the vapor deposition thin film layer (3) which consists of inorganic oxides by the urethane bond which reacts with the said acrylic polyol, and is mainly bridge | crosslinked. Acts as an agent or curing agent. Examples of the isocyanate compound having such an action include aromatic tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), aliphatic xylene diisocyanate (XDI), hexadiene isocyanate (HMDI), and isophorone diisocyanate (IPDI). And the like, and polymers and derivatives thereof. These may be used alone or in combination.
[0026]
The mixing ratio of the acrylic polyol and the isocyanate compound is not particularly limited. However, if the isocyanate compound is too small, the film may be poorly cured, and if it is too much, blocking may occur. Comes out. Therefore, the blending ratio of the acrylic polyol and the insocyanate compound is preferably such 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.
[0027]
The silane coupling agent, which is one of the mixtures constituting the primer layer (2), preferably has a functional group that reacts with the hydroxyl group of the acrylic polyol or the isocyanate group of the isocyanate compound. 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 And the like containing an epoxy group. These can be used alone or as a mixture of two or more. In these silane coupling agents, an organic functional group at one end exhibits an interaction in a composite composed of an acrylic polyol and an isocyanate compound to form a strong primer layer. Also, by using a silane coupling agent containing a functional group that reacts with the hydroxyl group of the acrylic polyol or the isocyanate group of the isocyanate compound, a strong primer layer derived from a covalent bond can be formed, and the alkoxy group at the other end can be hydrolyzed. Silanol groups generated by decomposition exhibit high adhesion to the deposited thin film layer (3) due to strong interaction with the metal in the inorganic oxide of the deposited thin film layer (3) and highly active hydroxyl groups on the surface of the thin film. Can be made. Moreover, you may use what hydrolyzed the said silane coupling agent with the metal alkoxide. Furthermore, there is no problem even if the alkoxy group of the silane coupling agent is a chloro group, an acetoxy group or the like, and these alkoxy groups, chloro groups, acetoxy groups, etc. are hydrolyzed to form a silanol group. For example, it can be used as one of a composite of primer layers.
[0028]
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.
[0029]
The thickness of the primer layer (2) is not particularly limited as long as the coating layer can be uniformly formed. However, it is generally preferred that the dried coating film be 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, when the thickness exceeds 2 μm, flexibility cannot be maintained in the coating film, and there is a possibility that the coating film may crack due to external factors, such being undesirable. Therefore, the thickness of the primer layer (2) is preferably in the range of 0.05 to 0.5 μm.
[0030]
As a method for forming the primer layer (2), for example, a known printing method such as an offset printing method, a gravure printing method, a silk screen printing method, or a known coating method such as roll coating, knife edge coating, or gravure coating is used. Can do. As drying conditions, generally used conditions are employed.
[0031]
Next, the vapor deposition thin film layer (3) made of an inorganic oxide will be described in detail.
The vapor deposition thin film layer (3) made of this inorganic oxide is the first layer constituting the gas barrier layer in the gas barrier film laminate having the high temperature processing resistance of the present invention. This vapor deposition thin film layer (3) is made of a vapor deposition thin film of an inorganic oxide such as aluminum oxide, silicon oxide, tin oxide, magnesium oxide, or a mixture thereof, and has transparency and gas barrier properties against oxygen, water vapor and the like. Any layer may be used. In consideration of various heat treatment resistances such as boil sterilization and retort sterilization performed when used as a packaging material, it is more preferable to use aluminum oxide or silicon oxide. However, the constituent material of the vapor-deposited thin film layer (3) is not limited to the above-described inorganic oxide, and other inorganic oxides can be used as long as the material meets the above conditions.
[0032]
The optimum thickness of the vapor-deposited thin film layer (3) varies depending on the type and configuration of the inorganic oxide to be used. In general, the thickness is preferably in the range of 5 to 300 nm, and the value takes into consideration various usage forms. It suffices to select appropriately within this range. However, if the film thickness is less than 5 nm, a uniform thin 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 that the thin film may be cracked due to external factors such as bending and pulling applied after the film formation. The thickness of the deposited thin film layer (3) is more preferably in the range of 10 to 150 nm.
[0033]
There are various methods for forming the vapor-deposited thin film layer (3) made of the inorganic oxide, but the usual vacuum vapor deposition method, other thin film formation methods such as sputtering, ion plating, and plasma vapor deposition are used. (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, any of an electron beam heating method, a resistance heating method, and an induction heating method may be used, but the electron beam heating method should be used in consideration of the wide selection of evaporation materials. Is more preferable. Further, in order to improve the adhesion between the deposited thin film layer (3) and the base material (1) and the denseness of the deposited thin film layer (3), it is also possible to use a plasma assist method or an ion beam assist method. . Further, in order to increase the transparency of the deposited thin film, it is possible to use a reactive deposition method in which various gases such as oxygen are blown during the deposition.
[0034]
Subsequently, the gas barrier coating layer (4) which is the second layer constituting the gas barrier layer will be described. The gas barrier coating layer (4) is formed by 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 coating agent is prepared by mixing a water-soluble polymer dissolved in an aqueous (water or water / alcohol mixed) solvent with a metal alkoxide directly or previously hydrolyzed. After coating this coating agent on the vapor-deposited thin film layer (3) made of inorganic oxide, this gas barrier coating layer (4) is formed by heating and drying.
[0035]
Next, each component contained in the coating agent will be described in detail below.
Examples of the water-soluble polymer used in the coating agent include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, and sodium alginate. In particular, polyvinyl alcohol (hereinafter abbreviated as PVA) is preferable because it has the best gas barrier properties when used as a coating agent. PVA here is generally obtained by saponifying polyvinyl acetate. As PVA, for example, so-called partially saponified PVA in which several tens percent of acetic acid groups remain, complete PVA in which only several percent of acetic acid groups remain, etc. can be used. I do not care.
[0036]
As the metal alkoxide, a general formula, M (OR) n (M: metal such as Si, Ti, Al, Zr, R: CH_Three, C₂H_FiveOr an alkyl group such as Specifically, tetraethoxysilane [Si (OC₂H_Five)_Four], Triisopropoxyaluminum [Al (O-2'-C_ThreeH₇)_ThreeAmong them, tetraethoxysilane and triisopropoxyaluminum are preferable because they are relatively stable in an aqueous solvent after hydrolysis.
[0037]
It is possible to add known additives such as isocyanate compounds, silane coupling agents, or dispersants, stabilizers, viscosity modifiers, colorants and the like to the solution as long as the gas barrier properties are not impaired. is there.
[0038]
As a method for applying the coating agent, conventionally known methods such as a dipping method, a roll coating method, a screen printing method, a spray method, and a gravure printing method that are usually used can be used.
[0039]
The thickness of the gas barrier coating layer (4) is not particularly limited because the optimum conditions vary depending on the type of coating agent, the processing machine, and the processing conditions. 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 coating film, which may be a problem. Therefore, the thickness is preferably in the range of 0.01 to 50 μm, more preferably in the range of 0.1 to 10 μm.
[0040]
  Next, the adhesive layer (5) made of a two-component curable polyurethane adhesive will be described in detail. When the adhesive layer (5) is used as a packaging material by laminating a gas barrier film having the hard gas barrier coating layer (4) as described above and an arbitrary film, the adhesive layer (5) has a high temperature by heat sterilization treatment or the like. If added, the gas barrier coating layer (4) is flexible for the purpose of preventing the occurrence of cracks etc.Consists of.
[0041]
  As a method for imparting flexibility to the adhesive, a two-component curable polyurethane adhesive is used as the adhesive, and the glass transition temperature in the cured film is set in the range of 5 to 20 ° C.TheBy setting the glass transition temperature within this range, the adhesive film after curing is in a rubbery state in the room temperature range that is normally used, and can maintain flexibility, and the packaging material is expanded and deformed by heat treatment. Even in this case, the coating can easily follow such movement, and as a result, no crack or the like is generated in the gas barrier coating (4). When the glass transition temperature is 20 ° C. or higher, the cured film of the adhesive is in a hard glass state in the room temperature region that is normally used, and thus causes cracking in the same manner as the hard gas barrier coating layer during heat treatment. Therefore, it is not preferable. Moreover, since the heat resistance of a contact bonding layer is inferior at the glass transition temperature of 5 degrees C or less, it is unpreferable.
[0042]
  From the above viewpoint, in the present invention,As detailed in the examples below,As a two-component curable polyurethane adhesive,The main agent is a polyester-based polyester polyol, the curing agent having an isocyanate group (polyisocyanate) is an adduct body of isophorone diisocyanate (IPDI), and the glass transition temperature of the cured film of the adhesive layer is 5 to 20 ° C. Use a range.
[0045]
Although the blending ratio of the main agent and the curing agent described above varies depending on the composition of the adhesive, the equivalent ratio of the hydroxyl group of the main agent to the isocyanate group of the curing agent may be a ratio of 1/1 to 1/3.
[0046]
Moreover, it is also possible to add additives, such as a silane coupling agent, a titanate coupling agent, phosphoric acids and its derivative compounds, and a polybasic acid anhydride, in a two-component curable polyurethane adhesive.
[0047]
The application amount of the two-component curable polyurethane adhesive varies depending on the function, application, etc., but the optimum condition varies, but it is 0.5 to 6.0 g / m.²Is preferable, and more preferably 1.0 to 4.0 g / m.²Range. Application amount is 0.5g / m²If it is less, it is difficult to apply uniformly, and 6.0 g / m.²If it is more, it takes time to completely cure the adhesive and the working efficiency is lowered.
[0048]
The basic structure of the gas barrier film laminate having heat treatment resistance according to the present invention has been described above. When used as a packaging material, printing is performed on an adhesive layer (5) made of a two-component curable adhesive. A layer, an intervening film layer, a sealant layer and the like may be appropriately laminated as necessary. FIG. 2 shows an example of a packaging material in which a sealant layer (6) is further provided on the adhesive layer (5) of the gas barrier laminate having high temperature resistance shown in FIG.
[0049]
The above-mentioned intervening film layer is provided to increase the bag breaking strength and piercing strength, and is generally biaxially stretched nylon film, biaxially stretched polyethylene terephthalate film, biaxially stretched in terms of mechanical strength and thermal stability. A polypropylene film is preferably used. The thickness is determined according to the material and required quality, but is generally in the range of 10 to 30 μm.
[0050]
Furthermore, the sealant layer is provided on the adhesive layer of the gas barrier film laminate having the high-temperature processing resistance described above, and is provided to serve as an adhesive layer as a packaging material for forming a bag-shaped package. Examples of the constituent material of such a sealant layer include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene. -Resins such as acrylic acid ester copolymers and 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.
[0051]
Moreover, it is also possible to laminate | stack a printing layer, an intermediate | middle film layer, a sealant layer, etc. on the opposite surface of a base material (1) as needed.
[0052]
【Example】
Next, the Example of the gas barrier film laminated body which has the heat processing tolerance of this invention is described concretely. The present invention is not limited to these examples.
First, the following adhesives ADH-1, ADH-2, ADH-3, and ADH-4 were prepared as two-component curable polyurethane adhesives.
[0053]
(Formulation of ADH-1)
Mixing adducts of polyester polyol as the main agent and isophorone diisocyanate (IPDI) as the curing agent so that each functional group ratio becomes 1/1, and further diluted with ethyl acetate so that the solid content is 30 wt% Then, an adhesive (ADH-1) was prepared. The glass transition temperature of the cured film of this adhesive was 13 ° C.
[0054]
(Formulation of ADH-2)
A polyester polyurethane polyol as a main agent and an adduct of isophorone diisocyanate (IPDI) as a curing agent are mixed so that each functional group ratio is 1/1, and further, ethyl acetate is added so that the solid content is 30 wt%. Dilution was performed to prepare an adhesive (ADH-2). The glass transition temperature of the cured film of this adhesive was 14 ° C.
[0055]
(Formulation of ADH-3)
A mixture of a polyester polyurethane polyol as a main agent, an adduct of isophorone diisocyanate (IPDI) and an adduct of xylylene diisocyanate (XDI) as a curing agent, and mixed so that each functional group ratio becomes 1/2, It diluted with ethyl acetate so that it might become 30 wt% in solid content, and the adhesive agent (ADH-3) was created. The glass transition temperature of the cured film of this adhesive was 17 ° C.
[0056]
(Formulation of ADH-4)
A mixture of a polyester polyol as a main agent and an adduct of isophorone diisocyanate (IPDI) and an adduct of xylylene diisocyanate (XDI) as a curing agent is mixed so that each functional group ratio is 1/1. Was diluted with ethyl acetate so that the solid content would be 30 wt%, to prepare an adhesive (ADH-4). The glass transition temperature of the cured film of this adhesive was 23 ° C.
[0057]
<Example 1>
In a diluting solvent (ethyl acetate), 10 parts by weight of acrylic polyol was mixed with 1 part by weight of γ-isocyanatopropyltrimethylsilane and stirred. Then, a 7 to 3 mixture of xylylene diisocyanate and isophorone diisocyanate was added as an isocyanate compound so that the isocyanate groups of this isocyanate compound were equivalent to the hydroxyl groups of the acrylic polyol. Then, this mixed solution was diluted to 2% by weight as the total concentration of the added compound to obtain a primer solution.
[0058]
Next, the liquid (1) and liquid (2) shown below were mixed at a blending ratio (wt%) of 6/4 to obtain a gas barrier coating solution.
{Circle around (1)} Liquid: A hydrolyzed solution having a solid content of 3 wt% (in terms of SiO 2) obtained by adding 89.6 g of hydrochloric acid (0.1N) to 10.4 g of tetraethoxysilane and stirring for 30 minutes for hydrolysis.
(2) Solution: 3 wt% water / isopropyl alcohol solution of polyvinyl alcohol (water: isopropyl alcohol is 90:10 by weight).
[0059]
Subsequently, a biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was used as the base material (1), and the above primer solution was applied to one side of the base material (1) by gravure coating and dried. A primer layer (2) having a thickness of 0.1 μm was formed. Next, a primer layer provided with the vapor deposition thin film layer (3) made of aluminum oxide having a thickness of 15 nm by evaporating metal aluminum therein and introducing oxygen gas therein using a vacuum vapor deposition apparatus by an electron beam heating method (2) Formed above.
Subsequently, the gas barrier coating solution was applied onto the deposited thin film layer (3) by a gravure coating method and dried to form a gas barrier coating layer (4) having a thickness of 0.4 μm. Further, on the gas barrier coating layer (4), the above two-component curable polyurethane adhesive (ADH-1) has a solid content of 3 g / m.²It was applied and dried on the vapor-deposited thin film layer (3) to provide an adhesive layer (5) to obtain a gas barrier laminate having high-temperature processing resistance.
On the adhesive layer (5) of this laminate, an unstretched polypropylene film having a thickness of 70 μm was laminated as a sealant layer to prepare a packaging material.
[0060]
<Example 2>
  This example is a reference example.
  A gas barrier film laminate and a packaging material were prepared under the same conditions as in Example 1 except that the above ADH-2 was used as a two-component curable polyurethane adhesive.
[0061]
<Example 3>
  This example is a reference example.
  A gas barrier film laminate and a packaging material were prepared under the same conditions as in Example 1 except that the above ADH-3 was used as a two-component curable polyurethane adhesive.
[0062]
<Comparative Example 1>
A gas barrier film laminate and a packaging material were prepared under the same conditions as in Example 1 except that the ADH-4 was used as a two-component curable polyurethane adhesive.
[0063]
<Evaluation method>
A pouch having four sides as a seal portion was prepared using a sheet-shaped packaging material partially including a gas barrier film laminate having high-temperature treatment resistance created in Examples and Comparative Examples, and 200 g of water was filled as a content. . Thereafter, retort sterilization at 121 ° C. for 30 minutes was performed.
Hereinafter, oxygen permeability before and after retort sterilization (measurement conditions: 30 ° C.-70% RH, unit: cm)^Three/ M²Table 1 shows the evaluation result of / day).
[0064]
[Table 1]

[0065]
【The invention's effect】
Since the gas barrier film laminate having high-temperature treatment resistance according to the present invention has the above-described configuration, it exhibits excellent gas barrier properties. In addition, this laminate has a high gas barrier property and a hard coating, but because an adhesive layer made of a two-component curable polyurethane adhesive having a low glass transition temperature and excellent flexibility is interposed, When designing packaging materials by bonding to other films, the gas barrier coating layer can be deformed following the flexibility of the adhesive, so cracks are unlikely to occur and heat treatment such as heat sterilization was performed. It is possible to maintain good gas barrier properties later.
Therefore, this gas barrier film laminate having high-temperature treatment resistance is expected to have great practical effects in packaging foods, retort foods, non-food products such as pharmaceuticals and electronic members.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a gas barrier film laminate having heat treatment resistance according to the present invention.
FIG. 2 is a schematic cross-sectional view of a packaging material using a gas barrier film laminate having heat treatment resistance according to the present invention.
[Explanation of symbols]
1 ... Base material
2 ... Primer layer
3 ... Vapor deposited thin film layer made of inorganic oxide
4 ... Gas barrier coating layer
5: Adhesive layer comprising a two-component curable polyurethane adhesive
6 ... Sealant layer

Claims (7)

A gas barrier film laminate having heat treatment resistance, wherein at least one coating layer formed by sequentially laminating the following four layers on at least one side of a base material made of a plastic material has the following two-component curable polyurethane adhesive: The main component of the two-component curable polyurethane adhesive of the adhesive layer is a polyester-based polyester polyol, and the curing agent having an isocyanate group (polyisocyanate) is an adduct body of isophorone diisocyanate (IPDI). A gas barrier film laminate having a heat treatment resistance, wherein the cured film of the layer has a glass transition temperature in the range of 5 to 20 ° C.
(1) A primer layer comprising a composite of an acrylic polyol, an isocyanate compound and a silane coupling agent.
(2) A deposited thin film layer made of an inorganic oxide.
(3) A gas barrier coating layer comprising a coating agent mainly comprising an aqueous solution or water / alcohol mixed solution containing a water-soluble polymer and one or more metal alkoxides or hydrolysates thereof. (4) An adhesive layer comprising a two-component curable polyurethane adhesive. The silane coupling agent is a gas barrier film laminate having a heat treatment resistance according to claim 1 Symbol mounting characterized as having an organic functional group reactive with at least one of the isocyanate groups of the hydroxyl or isocyanate compound an acrylic polyol. The gas barrier film laminate having heat treatment resistance according to claim 2, wherein the organic functional group contained in the silane coupling agent is any one of an isocyanate group, an epoxy group, and an amino group. The gas barrier film laminate having heat treatment resistance according to any one of claims 1 to 3 , wherein the inorganic oxide is aluminum oxide, silicon oxide, or a mixture thereof. The gas barrier film laminate having heat treatment resistance according to any one of claims 1 to 4 , wherein the metal alkoxide is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof. The water-soluble polymer, a gas barrier film laminate having a heat treatment resistance according to any one of claims 1 to 5, characterized in that a polyvinyl alcohol. The gas barrier film having heat treatment resistance according to any one of claims 1 to 6 , wherein at least one of a printing layer, an intervening film layer, and a sealant layer is provided on the coating layer side. Laminated body.

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