JP2002036419A - Gas barrier transparent laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier transparent laminate which is highly transparent with high gas barrier properties and is free from the deterioration of physical properties such as gas barrier properties even after boiling or retort sterilization and further, is highly suitable for practical use without the occurrence of defects such as delamination and with oustanding adhesion and resistance to boiling and retorting. SOLUTION: This gas barrier transparent laminate is formed of a transparent primer layer, a thin film vapor deposition layer composed of an inorganic oxide and a gas barrier coated layer sequentially laminated on at least one of the sides of a base made of a transparent plastic material, and further, a plastic film of a transparent plastic material as an intermediate layer laminated on the gas barrier coated layer through an adhesive and furthermore, a seal layer laminated on the plastic film through the adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate for packaging used in the field of packaging foods, non-foodstuffs, pharmaceuticals, etc., and is particularly used in the field of packaging requiring sterilization such as boil sterilization, retort sterilization and autoclave sterilization. The present invention relates to a gas barrier transparent laminate to be used.

[0002]

2. Description of the Related Art In recent years, packaging materials used for packaging foods, non-foodstuffs, pharmaceuticals, etc., include oxygen, which penetrates the packaging material, in order to suppress deterioration of contents and maintain their functions, properties and quality. It is necessary to prevent the influence of water vapor and other gases that alter the contents, and it is required to have a gas barrier property that blocks these various gases. Therefore, conventionally, a packaging material using a metal foil made of a metal such as aluminum, which is less affected by temperature, humidity, and the like, as a gas barrier layer has been generally used.

[0003] However, a packaging material using a metal foil made of a metal such as aluminum has excellent gas barrier properties.
Disadvantages include the inability to see through the packaging material to check the contents, the disposal of the material after use as incombustibles, and the inability to use metal detectors during inspections. I was

Accordingly, as a packaging material which overcomes these disadvantages, inorganic materials such as silicon oxide, aluminum oxide, magnesium oxide and the like described in, for example, US Pat. No. 3,442,686 and JP-B-63-28017. A film has been proposed in which an oxide is formed on a polymer film by forming a vapor-deposited film by a forming method such as a vacuum vapor deposition method or a sputtering method. These vapor-deposited films are known to have transparency and gas barrier properties against oxygen, water vapor, etc., and are suitable as packaging materials having both transparency and gas barrier properties that cannot be obtained with metal foils and the like. I have.

[0005]

However, a packaging material such as the above-mentioned vapor-deposited film is rarely used alone as a vapor-deposited film as a packaging container or a packaging material.・
The package is processed into a package through various processes such as printing a pattern or the like, laminating the pattern with a film or the like, or processing the shape of a package such as a container. In particular, the packaging material used for boil sterilization, retort sterilization, autoclave sterilization, or the like is sterilized through various processes, so that careful attention must be paid to the design of the packaging material.

[0006] Then, after the above-mentioned vapor-deposited film or the like is bonded to a sealant film and made into a bag, the contents are filled and boil sterilization and retort sterilization are attempted. After sterilization, delamination occurs in a part of the seal portion. It has been found that there are problems such as poor appearance, gas barrier properties being reduced from that part, and alteration of the contents.
Also, even if delamination does not occur,
It became clear that there was a difference in the oxygen barrier property after sterilizing boil and retort depending on the adhesive (ADH) used for lamination.

[0007] Therefore, the transparency that allows the contents to be directly seen through, the high gas barrier property that blocks gases that affect the contents, and the deterioration of the gas barrier property even after sterilizing boil, retort, or autoclave. It is desired to develop a gas-barrier transparent laminate having no boil resistance, retort resistance and autoclave resistance, which does not cause delamination or the like.

The present invention has been made in view of the above-mentioned problems, and has excellent transparency, high gas barrier properties, no deterioration in physical properties such as gas barrier properties even after boil sterilization or retort sterilization, and has a delamination property. It is an object of the present invention to provide a highly practical gas-barrier transparent laminate having excellent boil resistance and retort resistance, which is excellent in adhesiveness and does not cause the occurrence of cracks.

[0009]

Means for Solving the Problems The present invention has been made to achieve the above-mentioned object, and the invention of claim 1 comprises a transparent primer layer and an inorganic oxide on at least one surface of a substrate made of a transparent plastic material. A vapor-deposited thin film layer and a gas barrier coating layer are sequentially laminated, and a plastic film made of a transparent plastic material is laminated thereon as an intermediate layer via an adhesive, and a seal layer is further laminated on the plastic film via an adhesive. It is a gas barrier transparent laminate characterized by the following.

According to a second aspect of the present invention, in the gas barrier transparent laminate according to the first aspect, the adhesive comprises a polyester-polyurethane diol resin as a main component, and trimethylolpropane 3-isocyanatomethyl-3,3.
Adduct of 5,5-trimethylcyclohexaneisocyanate or 1,3-bis of trimethylolpropane
It is characterized by using a curing agent comprising an adduct of (isocyanatomethyl) benzene.

According to a third aspect of the present invention, in the gas barrier transparent laminate according to the first or second aspect, the transparent primer layer comprises a silane coupling agent or a hydrolyzate of the silane coupling agent, a polyol and an isocyanate compound. And a composite of

According to a fourth aspect of the present invention, there is provided a gas barrier transparent laminate, wherein the silane coupling agent according to the third aspect includes a functional group which reacts with at least one of a hydroxyl group of a polyol and an isocyanate group of an isocyanate compound. It is.

According to a fifth aspect of the present invention, in the gas barrier transparent laminate according to any one of the first to fourth aspects, the thickness of the transparent primer layer is in the range of 0.01 to 2 μm. Features.

According to a sixth aspect of the present invention, in the gas barrier transparent laminate according to any one of the first to fifth aspects, the inorganic oxide is aluminum oxide, silicon oxide, magnesium oxide, or a mixture thereof. It is characterized by the following.

According to a seventh aspect of the present invention, in the gas barrier transparent laminate according to any one of the first to sixth aspects, the vapor-deposited thin film layer made of the inorganic oxide has a thickness of 5 to 300.
nm.

According to an eighth aspect of the present invention, in the gas barrier transparent laminate according to any one of the first to seventh aspects, the gas barrier coating layer comprises a water-soluble polymer and (a) at least one metal. Alkoxides and hydrolysates thereof, or (b)
It is characterized in that a coating agent mainly comprising an aqueous solution containing at least one of tin chloride or a mixed solution of water / alcohol is applied and dried by heating.

According to a ninth aspect of the present invention, there is provided a gas barrier transparent laminate, wherein the metal alkoxide according to the eighth aspect is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof.

A tenth aspect of the present invention is the gas barrier transparent laminate, wherein the water-soluble polymer according to the eighth aspect is polyvinyl alcohol.

According to an eleventh aspect of the present invention, in the gas-barrier transparent laminate according to any one of the first to tenth aspects, the seal layer is made of a polyolefin-based thermoplastic resin.

According to a twelfth aspect of the present invention, there is provided the gas barrier transparent laminate according to any one of the first to eleventh aspects,
A gas-barrier transparent laminate, which is used as a packaging material for boiling or retorting.

<Action> According to the present invention, after providing a transparent primer layer having excellent dimensional stability and adhesion even after boil sterilization or retort sterilization on a transparent plastic substrate, an inorganic oxide having excellent gas barrier properties is provided. Adhesive used when laminating plastic film layers and seal layers made of transparent plastic material as an intermediate layer after laminating, such as boil sterilization and retort sterilization. As, by using an adhesive having a polyester-polyurethane diol resin as a main component,
A highly practical gas barrier transparent laminate without deterioration of gas barrier properties is obtained.

[0022]

Embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a sectional view showing an example of the configuration of the gas-barrier transparent laminate of the present invention.

As shown in FIG. 1, a gas-barrier transparent laminate according to the present invention comprises a transparent primer layer 2, a vapor-deposited thin film layer 3 made of an inorganic oxide, and a gas barrier coating layer on one surface of a substrate 1 made of a transparent plastic material. 4 is sequentially laminated, a transparent plastic layer 5 made of a transparent plastic material is laminated as an intermediate layer on the gas barrier coating layer 4 with an adhesive 7 interposed therebetween, and a seal layer is further formed on the plastic layer with an adhesive 7 interposed therebetween. 6 are stacked.

First, the adhesive used in the above configuration will be described. The adhesive 7 used in the present invention comprises a polyester-polyurethane diol resin as a main component and trimethylolpropane 3-isocyanatemethyl-.
It is characterized by using a curing agent consisting of an adduct of 3,5,5-trimethylcyclohexaneisocyanate or an adduct of trimethylolpropane with 1,3-bis (isocyanatomethyl) benzene. The gas barrier transparent laminate of the present invention is particularly preferably used in a packaging field requiring boil sterilization or retort sterilization, autoclave sterilization, or the like, and includes boil sterilization, retort sterilization, delamination after autoclave sterilization, and oxygen barrier There must be no decline in sex. In addition to the purpose of bonding the transparent plastic layer 5 and the sealing layer 6 made of a transparent plastic material as an intermediate layer, the adhesive has been studied intensively. The present invention has been found to alleviate a decrease in barrier properties, and has led to the present invention. Polyester polyurethane diol used as a main component of the adhesive includes polybasic acid and polyhydric alcohol and 3-isocyanatomethyl-3,5,5-
It is made by a mixture of trimethylcyclohexyl isocyanate, and 3-isocyanatomethyl-trimethylolpropane used as a curing agent.
A curing agent consisting of an adduct of 3,5,5-trimethylcyclohexaneisocyanate or an adduct of trimethylolpropane with 1,3-bis (isocyanatomethyl) benzene can be used.

As the substrate 1 made of a transparent plastic material used in the present invention, a transparent plastic film is used in order to make use of the transparency of the vapor-deposited thin film layer. For example, polyethylene terephthalate (PET), polyester films such as polyethylene naphthalate, polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films, polyvinyl chloride films, polycarbonate films, polyacrylonitrile films, polyimide films, and the like.
Either stretched or unstretched may be used, and those having mechanical strength and dimensional stability are preferred. The transparent plastic material is processed into a film and used. In particular, polyethylene terephthalate arbitrarily stretched in the biaxial direction is preferably used. Also, in this substrate, various well-known additives and stabilizers, for example, an antistatic agent, an ultraviolet ray inhibitor, a plasticizer,
A lubricant or the like can be added. Further, in order to enhance the adhesiveness to the thin film, the surface of the base material may be subjected to a pretreatment such as a corona treatment, a low-temperature plasma treatment, and an ion bombardment treatment. Alternatively, chemical treatment, solvent treatment, or the like may be performed.

Although the thickness of the substrate is not particularly limited, it is suitable for packaging materials, and the processability when laminating other layers such as a transparent primer layer, an inorganic oxide vapor-deposited thin film layer, and a gas barrier coating layer. Is practically 3 to 2
It is appropriately selected in the range of 00 μm, and in the range of 6 to 30 μm depending on the use.

In consideration of mass productivity, it is desirable that the film is a long web-like film on which each layer can be formed continuously.

The transparent primer layer 2 in the present invention is provided on a substrate 1 made of a transparent plastic material, and enhances the adhesion between the substrate 1 and the vapor-deposited thin film layer 3 made of an inorganic oxide. The purpose of the present invention is to prevent the occurrence of delamination and the like after boil sterilization, retort sterilization, and autoclave sterilization of the gas barrier transparent laminate.

The transparent primer layer 2 of the present invention
Is characterized by comprising a complex of a silane coupling agent or a hydrolyzate of the silane coupling agent, a polyol and an isocyanate compound.

Hereinafter, the composite constituting the transparent primer layer will be described in detail. As an example of the silane coupling agent, a silane coupling agent containing any organic functional group can be used, for example, ethyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyl Trimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
One or more silane coupling agents such as γ-methacryloxypropylmethyldimethoxysilane or hydrolysates thereof can be used.

Further, among the above silane coupling agents, those having a functional group which reacts with a hydroxyl group of a polyol or an isocyanate group of an isocyanate compound are particularly preferable. For example, those containing isocyanate groups such as γ-isocyanatopropyltriethoxysilane and γ-isocyanatopropyltrimethoxysilane, those containing mercapto groups such as γ-mercaptopropyltriethoxysilane, and those containing γ-aminopropyltriethoxysilane , Γ-aminopropyltrimethoxysilane, N-β-
Some include an amino group such as (aminoethyl) -γ-aminopropyltriethoxysilane and γ-phenylaminopropyltrimethoxysilane. Furthermore, γ-glycidoxypropyltrimethoxysilane and β- (3,4-
An alcohol or the like is added to a compound containing an epoxy group such as epoxycyclohexyl) ethyltrimethoxysilane or a silane coupling agent such as vinyltrimethoxysilane or vinyl (β-methoxyethoxy) silane to add a hydroxyl group or the like. And one or more of these may be used. In these silane coupling agents, an organic functional group present at one end interacts in a composite composed of a polyol and an isocyanate compound, or a silane coupling agent containing a functional group that reacts with a hydroxyl group of a polyol or an isocyanate group of an isocyanate compound. A stronger primer layer is formed by giving a covalent bond by using a ring agent, and a silanol group generated by hydrolysis of an alkoxy group or the like at the other end is a metal in the inorganic oxide or a surface of the inorganic oxide. It exhibits high adhesion to inorganic oxides by strong interaction with a highly active hydroxyl group or the like, and can obtain desired physical properties. Therefore, a silane coupling agent obtained by a hydrolysis reaction with a metal alkoxide may be used. 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, and the like are hydrolyzed to form a silanol group. If present, it can be used for this composite.

Further, the transparent primer layer 2 of the present invention
Is a transparent primer layer composed of a complex of a silane coupling agent or a hydrolyzate of the silane coupling agent with a polyol and an isocyanate compound. The polyol has two or more hydroxyl groups at a polymer terminal and is reacted with an isocyanate group of an isocyanate compound to be added later. Among them, a polyol obtained by polymerizing an acrylic acid derivative monomer or an acrylic polyol which is a polyol obtained by copolymerizing an acrylic acid derivative monomer and another monomer is particularly preferable. 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 adding and copolymerizing other monomers such as styrene are preferably used. In consideration of the reactivity with the isocyanate compound and the compatibility with the silane coupling agent, the hydroxyl value is preferably in the range of 5 to 200 (KOH mg / g).

The mixing ratio of the polyol and the silane coupling agent is preferably in the range of 1/1 to 1000/1 by weight, more preferably in the range of 2/1 to 100/1. The solvent for dissolution and dilution is not particularly limited as long as it can be dissolved and diluted,
For example, those in which esters such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol, and isopropyl alcohol, ketones such as methyl ethyl ketone, and aromatic hydrocarbons such as toluene and xylene are used alone or in any combination. be able to. However, since an aqueous solution such as hydrochloric acid may be used for hydrolyzing the silane coupling agent, it is more preferable to use a solvent obtained by arbitrarily mixing isopropyl alcohol or the like and ethyl acetate as a polar solvent as a co-solvent.

Further, the isocyanate compound to be mixed is
It is added to enhance adhesion to a substrate or an inorganic oxide by urethane bonds formed by reacting with a polyol, and mainly acts as a crosslinking agent or a curing agent. In order to achieve this, monomers such as aromatic tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), aliphatic xylene diisocyanate (XDI) and hexaylene diisocyanate (HMDI), These polymers,
Derivatives are used, and one or more of them can be used.

The blending ratio of the polyol and the isocyanate compound is not particularly limited. However, if the amount of the isocyanate compound is too small, curing may be poor, and if the amount is too large, blocking or the like may occur and processing problems may occur. is there. Therefore, the blending ratio of the polyol and the insocyanate compound is preferably such that the NCO group derived from the isocyanate compound is at most 50 times the OH group derived from the polyol, and particularly preferably the NCO group and the OH group are blended in equivalent amounts. Is the case. A known method can be used for the mixing method, and is not particularly limited.

As a method for preparing a primer solution for forming a composite film in the present invention, a composite solution in which a silane coupling agent, a polyol and an isocyanate compound are mixed at an arbitrary concentration is prepared, and the other is used as a substrate. 1 to be formed. As a method of producing the composite solution,
Mix silane coupling agent and acrylic polyol,
After diluting to a desired concentration by adding a solvent and diluent, mixing with an isocyanate compound to prepare a composite solution, or mixing a silane coupling agent and a polyol in a solvent and reacting the silane coupling agent and the polyol in advance After diluting the solvent and diluent to any concentration,
There is a method of preparing a composite solution by adding an isocyanate compound.

Various additives such as a curing accelerator such as a tertiary amine, an imidazole derivative, a metal salt compound of a carboxylic acid, a quaternary ammonium salt, and a quaternary phosphonium salt; It is also possible to add an antioxidant such as a phytoid, a leveling agent, a flow regulator, a catalyst, a crosslinking reaction accelerator, a filler, and the like.

As a method for forming the transparent primer layer, 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 coat, knife edge coat or gravure coat is used. A transparent primer layer can be obtained by coating on a base material, and then drying and drying the coating film to remove a solvent and the like, followed by curing.

In the present invention, the thickness of the transparent primer layer 2 is in the range of 0.01 to 2 μm. It is necessary to form a coating film uniformly. When the thickness is less than 0.01 μm, it is difficult to obtain a uniform coating film, and the adhesion may be reduced. On the other hand, if the thickness exceeds 2 μm, the coating film cannot be kept flexible because of its thickness, and the coating film may be cracked by external factors, which is not preferable. Particularly, 0.05 to 0.5 μm
Is preferable.

Next, the thin film layer 3 made of an inorganic oxide according to the present invention is characterized in that the inorganic oxide is aluminum oxide, silicon oxide, tin oxide, magnesium oxide or a mixture thereof. . Among them, aluminum oxide and silicon oxide are particularly preferable. Materials other than those described above can be used as long as they have transparency and gas barrier properties such as oxygen and water vapor.

The thickness of the deposited thin film layer 3 made of an inorganic oxide is in the range of 5 to 300 nm. The optimum conditions for the thickness of the thin film layer vary depending on the type and configuration of the inorganic compound used, but the value is appropriately selected. 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. On the other hand, if the thickness exceeds 300 nm, flexibility cannot be maintained in the thin film, and the thin film may be cracked by external factors such as bending and pulling after the film is formed. It is particularly preferred that it is within the range of 10 to 150 nm.

There are various methods for forming the above-mentioned inorganic oxide thin film layer on the transparent primer layer, which can be formed by an ordinary vacuum deposition method. , A plasma vapor deposition (CVD) method, or the like. However, in consideration of productivity, the vacuum deposition method is currently the most excellent. As a heating means of the vacuum evaporation apparatus by the vacuum evaporation method, an electron beam heating method, a resistance heating method, and an induction heating method are preferable. In order to improve the adhesion between the thin film and the base material and improve the denseness of the thin film, a plasma assist method or an ion heating method is used. It is also possible to use a beam assist method. Also,
In order to increase the transparency of the deposited film, reactive vapor deposition such as blowing oxygen gas may be performed during vapor deposition.

The gas barrier coating layer 4 is provided on the inorganic oxide thin film layer 3 in order to provide gas barrier properties as high as aluminum foil depending on required quality.

The gas barrier coating layer 4 is made of an aqueous solution or a water / alcohol mixed solution containing at least one of a water-soluble polymer and (a) at least one metal alkoxide and a hydrolyzate or (b) tin chloride. It consists of a coating agent used as the main agent. Mineralize a solution in which a water-soluble polymer and tin chloride are dissolved in an aqueous (water or water / alcohol mixture) solvent, or a solution in which a solution obtained by directly or beforehand hydrolyzing a metal alkoxide is mixed. It is formed by coating the oxide thin film layer 3 and drying by heating. Each component contained in the coating agent will be described in more detail.

The water-soluble polymer used for the coating agent in the present invention includes polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate and the like. In particular, when polyvinyl alcohol (hereinafter, referred to as PVA) is used as a coating agent for the laminate of the present invention, the gas barrier properties are most excellent. The PVA referred to here is generally obtained by saponifying polyvinyl acetate, and a few percent of acetic acid groups remain from so-called partially saponified PVA in which several tens of percent of acetic acid groups remain.
There is no particular limitation, including up to complete PVA that only remains.

In addition, tin chloride is formed from stannous chloride (SnCl).
₂ ), stannic chloride (SnCl ₄ ), or a mixture thereof, and either anhydrous or hydrated can be used.

Further, the metal alkoxide is tetraethoxy.
Sisilane [Si (OC_TwoH_Five )_Four], Triisopropoxy
Aluminum [Al (O-2'-C_ThreeH₇ )_Three〕Such
The general formula of M (OR) n (M: Si, Ti, Al, Z
metals such as r, R: CH_Three , C _Two H_Five Alkyl group)
It can be expressed. Among them, tetraethoxysilane, tri
After isopropoxyaluminum is hydrolyzed, an aqueous solvent
It is preferable because it is relatively stable in the inside.

Each of the above-mentioned components can be added to the coating agent alone or in combination of several components. Isocyanate compounds, silane coupling agents, dispersants, and stabilizers are also provided as long as the gas barrier properties of the coating agent are not impaired. Known additives such as a viscosity modifier and a coloring agent can be added.

For example, an isocyanate compound added to a coating agent has two or more isocyanate groups (NCO groups) in its molecule. For example, tolylene diisocyanate (hereinafter, TDI), triphenylmethane triisocyanate (hereinafter, triphenylmethane triisocyanate) There are monomers such as TTI) and tetramethyl xylene diisocyanate (TMXDI), and polymers and derivatives thereof.

As a method of applying the coating agent, conventionally known means such as a commonly used dipping method, roll coating method, screen printing method, spray method and the like can be used. The thickness of the coating varies depending on the type of coating agent and processing conditions, but the thickness after drying is 0.01μ.
It is sufficient that the thickness is at least m, but if the thickness is at least 50 μm, cracks are likely to occur in the film.

Further, other layers can be laminated on the inorganic oxide thin film layer 3 and the gas barrier coating layer 4. For example, it is a printing layer, an intermediate layer, a heat seal layer, or the like. The printing layer is formed for practical use as a packaging bag or the like, and various types of conventionally used ink binder resins such as urethane, acrylic, nitrocellulose, rubber, and vinyl chloride are used. It is a layer composed of an ink to which additives such as a pigment, an extender pigment, a plasticizer, a desiccant, and a stabilizer are added. As a forming method, for example, a well-known printing method such as an offset printing method, a gravure printing method, or a silk screen printing method, or a well-known coating method such as a roll coat, a knife edge coat, or a gravure coat can be used. The thickness may be 0.1 to 2.0 μm.

The plastic film outer layer 5 made of a transparent plastic material as an intermediate layer is provided to increase the strength of bag breaking during sterilization of boiling and retort, and is particularly biaxially stretched in view of mechanical strength and thermal stability. It must be a kind selected from a nylon film, a biaxially oriented polyethylene terephthalate film, and a biaxially oriented polypropylene film. The thickness is determined according to the material, required quality, and the like, but is generally in the range of 10 to 30 μm. As a forming method, lamination can be performed by a dry lamination method in which an adhesive containing a polyester-polyurethane diol resin as a main component is attached.

The seal layer 6 is provided as an adhesive layer when forming a bag-like package. For example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer and metal cross-linking thereof A resin such as a product is used. The thickness is determined according to the purpose, but is generally in the range of 15 to 200 μm. As a forming method, it can be laminated by a dry lamination method in which a film-like material made of the above resin is attached using an adhesive mainly composed of a polyester-polyurethanediol resin.

[0054]

EXAMPLES The gas barrier transparent laminate of the present invention will be further described below with reference to specific examples.

Example 1 In a diluting solvent, 1 part by weight of γ-isocyanatopropyltrimethoxysilane and 10 parts by weight of acrylic polyol were mixed and stirred. Next, a mixture of 3-isocyanatomethyl-3,5,5-trimethylcyclohexaneisocyanate (IPDI) of trimethylolpropane / 1,3-bis (isocyanatomethyl) benzene (XDI) of trimethylolpropane as an isocyanate compound was added to OH of acrylic polyol. A solution obtained by diluting a mixed solution to which NCO groups are added in an equal amount with respect to the groups to an arbitrary concentration is used as a primer solution. The primer solution was formed as a transparent primer layer 2 on one surface of a biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm as a substrate 1 to a thickness of 0.1 μm by a gravure coating method. Next, metal aluminum was evaporated on the transparent primer layer 2 by a vacuum evaporation apparatus using an electron beam heating method, and oxygen gas was introduced into the aluminum layer.
m of aluminum oxide was deposited to form an inorganic oxide thin film layer 3. Further, the composition A solution and the solution B described below were further mixed with 60 /
A coating agent mixed at a ratio of 40 (wt%) was applied by a gravure coating method to form a gas barrier coating layer 4 having a thickness of 0.3 μm. Solution A: 10.4 g of tetraethoxysilane and hydrochloric acid (0.1
N) 89.6 g was added thereto, and the mixture was stirred for 30 minutes and hydrolyzed to obtain a hydrolyzed solution having a solid content of 3 wt% (in terms of SiO ₂ ). Liquid B: a 3 wt% water / isopropyl alcohol solution of polyvinyl alcohol. (Water: isopropyl alcohol weight ratio 90:10)) Next, a polyester-polyurethane diol resin, a curing agent composed of an IPDI adduct or an XDI adduct was used as an adhesive, and a 15 μm thick intermediate layer 5 was used. A biaxially stretched nylon film is laminated by a dry lamination method, and a low-density polyethylene film having a thickness of 40 μm is laminated by a dry lamination method as a polyolefin-based thermoplastic resin layer for forming a seal layer 6. A transparent laminate was obtained.

<Comparative Example 1> In Example 1, as another general retort adhesive, an adhesive for polyester-urethane dry lamination (manufactured by Takeda Pharmaceutical Co., Ltd.)
A gas-barrier transparent laminate for comparison was obtained in the same manner as in Example 1 except that "A-515" adhesive) was used.

<Test 1> A four-way pouch was prepared from the gas-barrier transparent laminate obtained in Example 1 and Comparative Example 1 for retort sterilization, and the content was 150 g of water.
, And sterilized by retort at 90 ° C. for 30 minutes.
As an evaluation, using a device of MOCON OXTRAN10 / 50 (manufactured by Modern Control Co.), 30 ° C.-70
% RH before and after retorting under the measurement conditions of% RH (cc / m ² / day) and lamination strength (N / 15)
mm). The occurrence of delamination after retort was observed by visual observation, the aluminum element was detected from the substrate and the sealant film by a fluorescent X-ray device, and the peeled surface was estimated. Table 1 shows the results.

[0058]

[Table 1]

As shown in Table 1 above, before retort,
Both the gas-barrier transparent laminates of Example 1 and Comparative Example 1 have no problem in adhesion and gas-barrier properties, but the results after retort show that the gas-barrier transparent laminates obtained in Example 1 show gas-barrier properties. Degradation is small, and it can be seen that the adhesive layer is peeled off even when the peeled surface is observed, and high adhesion is maintained. On the other hand, the sbarrier transparent laminate obtained in Comparative Example 1 has It can be seen that the decrease in oxygen barrier properties is large. Therefore, the gas-barrier transparent laminate of the present invention has a high gas-barrier property to block gases and the like that affect the contents, does not deteriorate even after retort, and has no delamination. Satisfies all retort properties.

[0060]

As described above, according to the present invention,
Excellent transparency, high gas barrier properties, no deterioration in physical properties such as gas barrier properties even after boil sterilization and retort sterilization, and excellent boil resistance and retort resistance that do not cause delamination etc. It has become possible to provide a highly practical gas barrier transparent laminate having the following characteristics. Therefore, the gas-barrier transparent laminate of the present invention is widely used in the field of packaging foods, non-foods, pharmaceuticals, and the like, and is particularly suitably used in the field of packaging that requires sterilization of boil, retort, and autoclave.

[0061]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a configuration of a gas barrier transparent laminate according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transparent plastic base material 2 ... Transparent primer layer 3 ... Inorganic oxide thin film layer 4 ... Gas barrier coating layer 5 ... Intermediate layer (transparent plastic film) 6 ... Seal layer 7 ... Adhesive layer

Front page of the continued F-term (reference) 4F100 AA01C AA18C AA19C AA20C AH03G AK01A AK01D AK01E AK03E AK06 AK21D AK41G AK51G AR00B AR00D AR00E BA05 BA07 BA10A BA10E BA13 CA02G CB02 EH66C GB15 GB23 JA20B JA20C JB09D JB16E JD02D JL01E JM02C JN01A JN01B JN01E YY00B YY00C 4J040 EF111 EF321 LA08 LA10 MA08 MB03 NA08

Claims (12)

[Claims] 1. A transparent primer layer, a vapor-deposited thin film layer made of an inorganic oxide, and a gas barrier coating layer are sequentially laminated on at least one side of a substrate made of a transparent plastic material, and further, an intermediate layer is formed thereon via an adhesive. A plastic film made of a transparent plastic material is laminated thereon, and a sealing layer is further laminated on the film via an adhesive. 2. The adhesive according to claim 1, wherein said adhesive is a polyester-polyurethanediol resin as a main component, and an adduct of 3-isocyanatomethyl-3,5,5-trimethylcyclohexaneisocyanate of trimethylolpropane or 1,3-bis (trimethylolpropane). 2. The gas-barrier transparent laminate according to claim 1, wherein a curing agent comprising an adduct of (isocyanatomethyl) benzene is used. 3. The gas barrier according to claim 1, wherein the transparent primer layer comprises a silane coupling agent or a compound of a hydrolyzate of the silane coupling agent and a polyol and an isocyanate compound. Transparent laminate. 4. The silane coupling agent according to claim 3, wherein
A gas barrier transparent laminate comprising a functional group that reacts with at least one of a hydroxyl group of a polyol and an isocyanate group of an isocyanate compound. 5. The transparent primer layer having a thickness of 0.01
5. The method according to claim 1, wherein the distance is in a range of from 2 to 2 [mu] m.
The gas-barrier transparent laminate according to any one of the above. 6. The gas barrier transparent laminate according to claim 1, wherein the inorganic oxide is aluminum oxide, silicon oxide, magnesium oxide, or a mixture thereof. 7. The gas-barrier transparent laminate according to claim 1, wherein a thickness of the vapor-deposited thin film layer made of the inorganic oxide is in a range of 5 to 300 nm. 8. An aqueous solution or a mixed solution of water / alcohol, wherein the gas barrier coating layer comprises a water-soluble polymer and at least one of (a) at least one metal alkoxide and its hydrolyzate, or (b) tin chloride. The gas-barrier transparent laminate according to any one of claims 1 to 7, wherein a coating agent mainly comprising is applied and heated and dried. 9. The gas-barrier transparent laminate according to claim 8, wherein the metal alkoxide is tetraethoxysilane or triisopropoxyaluminum, or a mixture thereof. 10. The gas-barrier transparent laminate according to claim 8, wherein the water-soluble polymer is polyvinyl alcohol. 11. The method according to claim 1, wherein said seal layer is made of a polyolefin-based thermoplastic resin.
0. The gas-barrier transparent laminate according to any one of 0. 12. A gas-barrier transparent laminate, wherein the gas-barrier transparent laminate according to any one of claims 1 to 11 is used as a packaging material for boiling or retort.