JP2000218726A - Strong adhesion transparent laminate - Google Patents

Abstract

(57) [Summary] [Purpose] Practical with excellent boil resistance and retort resistance that have excellent transparency, high gas barrier properties, no deterioration in physical properties even after boil sterilization and retort sterilization, and no occurrence of peeling phenomenon. Provide highly flexible packaging materials. An aqueous solution containing at least one of a transparent primer layer, an inorganic oxide thin film layer, a water-soluble polymer and at least one metal alkoxide and a hydrolyzate thereof, or tin chloride on one surface of a substrate film. Alternatively, a coating agent having a water / alcohol mixed solution as a main component is applied, and a gas barrier coating layer 4 obtained by drying is sequentially laminated, and a transparent plastic material 5 is further laminated via an adhesive layer. The sealing layer 6 was laminated on the opposite surface on which the primer layer was provided via an adhesive layer.

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 of foods, non-foodstuffs, pharmaceuticals, and the like, and particularly to a packaging requiring a sterilization step such as boiling sterilization, retort sterilization, and autoclave sterilization. It is about the field.

[0002]

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

[0003] However, a packaging material using a metal foil such as an aluminum foil is excellent in gas barrier properties, but the contents cannot be checked through the packaging material. However, there are drawbacks such as the need to perform the inspection and the inability to use a metal detector during the inspection.

[0004] Therefore, as a packaging material which overcomes these disadvantages, for example, inorganic oxides such as silicon oxide, aluminum oxide, magnesium oxide and the like described in US Pat. No. 3,442,686, JP-B-63-28017, etc. A film has been developed in which an object is formed on a polymer film by forming a vapor-deposited film by a forming means such as a vacuum vapor deposition method or a sputtering method. These deposited films are known to have transparency and gas barrier properties such as oxygen and water vapor,
It is considered to be suitable as a packaging material having both transparency and gas barrier properties that cannot be obtained with metal foil or the like.

[0005]

However, even a film suitable for the above-mentioned packaging material is rarely used alone as a vapor deposition film as a packaging container or a packaging material. A package is completed through various processes such as printing or laminating characters and pictures on the surface or laminating the film with a film or the like, and shape processing into a package such as a container. In particular, packaging materials used for boil sterilization, retort sterilization, autoclave sterilization, and the like are sterilized through various processes. Therefore, sufficient attention must be paid to the design of the packaging materials.

[0006] Then, after laminating a bag with a sealant film using the above-mentioned vapor-deposited film or the like, and filling the contents, and then attempting to sterilize boil or retort, a peeling phenomenon occurs in a part of the seal portion after sterilization. It has been found that there are problems such as poor appearance and deterioration of the gas barrier properties from the portion, resulting in deterioration of the contents.

In other words, the conditions used as a packaging material in such a case include transparency that allows the contents to be directly seen through, high gas barrier properties that block gases that affect the contents, and the like. Boil sterilization, retort sterilization, no deterioration of gas barrier properties even after autoclave sterilization, and it is required to have boil resistance, retort resistance and autoclave resistance such as no peeling phenomenon, etc. No packaging material has been found that meets all.

[0008] Therefore, in the present invention, excellent transparency,
Another object of the present invention is to provide a highly practical packaging material having boil resistance and retort resistance that have high gas barrier properties, do not deteriorate in physical properties even after boil sterilization and retort sterilization, and do not cause peeling phenomena. .

[0009]

Means for Solving the Problems The present invention has been made to achieve the above object, and the invention described in claim 1 is to provide a transparent primer layer having a thickness of 5 to 300 nm on at least one surface of a substrate film. The main component is an aqueous solution or a water / alcohol mixed solution containing at least one of a vapor-deposited thin film layer made of an inorganic oxide, a water-soluble polymer, and (a) at least one of a metal alkoxide and a hydrolyzate thereof, and (b) tin chloride. A gas barrier coating layer is formed by applying a coating agent, and then drying by heating.Then, a transparent plastic material is laminated via an adhesive layer, and then adhered to the opposite side of the substrate film on which the transparent primer layer is provided. A strongly adhered transparent laminate characterized by laminating a polyolefin-based thermoplastic resin as a seal layer via an agent layer.

According to a second aspect of the present invention, based on the first aspect, the transparent plastic material is one selected from a biaxially oriented nylon film, a biaxially oriented polyethylene terephthalate film, and a biaxially oriented polypropylene film. It is a strong adhesion transparent laminate characterized by the following.

According to a third aspect of the present invention, based on the first or second aspect, the transparent primer layer is a composite of a silane coupling agent or a hydrolyzate of the silane coupling agent, and a polyol and an isocyanate compound. And a transparent primer layer comprising:

According to a fourth aspect of the present invention, based on the first to third aspects, the silane coupling agent contains 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 a strong adhesion transparent laminate.

According to a fifth aspect of the present invention, based on the first to fourth aspects, the transparent primer layer has a thickness of 0.0
A strongly adhered transparent laminate having a thickness of 1 to 2 μm.

According to a sixth aspect of the present invention, based on the first to fifth aspects, the inorganic oxide is aluminum oxide,
A strongly adherent transparent laminate characterized by being silicon oxide, magnesium oxide or a mixture thereof.

According to a seventh aspect of the present invention, based on the first to sixth aspects, the metal alkoxide is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof. Body.

The invention of claim 8 is based on the invention of claims 1 to 7, wherein the water-soluble polymer is a polyvinyl alcohol, wherein the water-soluble polymer is polyvinyl alcohol.

[0017]

According to the present invention, a transparent primer layer having excellent dimensional stability and adhesion is provided on a substrate film, and then an inorganic oxide layer having excellent gas barrier properties is laminated. A highly practical laminate is obtained without occurrence of peeling phenomenon or deterioration of gas barrier properties even after boil-killing bacteria or retort sterilization.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a strongly adhered transparent laminate of the present invention.

First, the strongly adhered transparent laminate of the present invention shown in FIG. 1 will be described. 1 is a film composed of a transparent plastic material, on which a transparent primer layer 2 composed of a composite of a silane coupling agent, a polyol and an isocyanate compound, a vapor-deposited thin film layer 3 composed of an inorganic oxide, a gas barrier The coating layers 4 are sequentially laminated. A transparent plastic material 5 is laminated on the gas barrier coating layer of the composite film, and a polyolefin-based thermoplastic resin is laminated as a seal layer 6 on the opposite surface of the base film.

Incidentally, it goes without saying that a transparent primer layer, an inorganic oxide vapor-deposited thin film layer, and a gas barrier coating layer may be sequentially laminated between the base film 1 and the seal layer 6. Further, the gas barrier coating layer and the seal layer are laminated via an adhesive layer.

The above-mentioned substrate film 1 is preferably a transparent film in order to make use of the transparency of the 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 are used. Either stretched or unstretched may be used, and those having mechanical strength and dimensional stability are preferred. These are processed into a film and used. Particularly, polyethylene terephthalate arbitrarily stretched in the biaxial direction is preferably used. Various known additives and stabilizers, for example, an antistatic agent, a UV inhibitor, a plasticizer, a lubricant, and the like may be used on the surface of the base film 1 to improve the adhesion to the thin film. For this purpose, a corona treatment, a low-temperature plasma treatment, an ion bombardment treatment, or a chemical treatment, a solvent treatment, or the like may be performed as a pretreatment.

Although the thickness of the base film 1 is not particularly limited, it is suitable as a packaging material, other layers may be laminated, the transparent primer layer 2 and the inorganic oxide deposited thin film layer 3, In consideration of workability when forming the gas barrier coating layer 4, it is practically preferably in the range of 3 to 200 µm, and more preferably 6 to 30 µm depending on the use.

Further, in consideration of mass productivity, it is desirable to use a long film so that each layer can be formed continuously.

The transparent primer layer 2 is provided on the base film 1 to enhance the adhesion between the base film 1 and the vapor-deposited thin film layer 3 made of an inorganic oxide. An object of the present invention is to prevent the occurrence of a peeling phenomenon or the like.

As a result of intensive studies, it is necessary that a compound of a silane coupling agent or a hydrolyzate thereof, a polyol and an isocyanate compound, etc. be used as a primer resin in order to achieve the above object.

Further, 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 these 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, γ-isocyanatopropyltriethoxysilane, those containing isocyanate groups such as γ-isocyanatopropyltrimethoxysilane, those containing mercapto groups such as γ-mercaptopropyltriethoxysilane, and γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β-
Some include an amino group such as (aminoethyl) -γ-aminopropyltriethoxysilane and γ-phenylaminopropyltrimethoxysilane. Further, 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 shows an interaction in a composite comprising a polyol and an isocyanate compound, or a silane coupling agent containing a functional group which 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,
Any compound that forms a silanol group can be used for this composite.

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 between 5 and 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. Dissolution and dilution solvents include:
It is not particularly limited as long as it can be dissolved and diluted. Examples thereof include esters such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as methyl ethyl ketone, and aromatics such as toluene and xylene. Hydrocarbons and the like may be used alone or arbitrarily blended. 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 added in order to increase the adhesion to the base material and the inorganic oxide by the urethane bond formed by reacting with the 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 and derivatives are used, and one or more of these 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, the curing may be poor. 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 prepared by mixing a silane coupling agent, a polyol, and an isocyanate compound at an arbitrary concentration is used as the base material 1. Formed by coating. 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 tertiary amines, imidazole derivatives, metal salt compounds of carboxylic acids, quaternary ammonium salts, quaternary phosphonium salts, and other curing accelerators; 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.

The method for forming the transparent primer layer 2 is as follows.
For example, a known printing method such as an offset printing method, a gravure printing method, or a silk screen printing method, or a known coating method such as a roll coating, a knife edge coating, or a gravure coating is used to coat the substrate 1 and then a coating film is formed. The transparent primer layer 2 can be obtained by drying and drying to remove the solvent and the like and to cure.

The thickness of the transparent primer layer 2 is not particularly limited as long as a uniform coating film can be formed, but is generally preferably in the range of 0.001 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 reduced. On the other hand, if the thickness exceeds 2 μm, it is not preferable because the film cannot keep flexibility because of the thickness and there is a possibility that the film may be cracked by external factors. Particularly preferred is 0.05 to
It is within the range of 0.5 μm.

Next, the thin film layer 3 made of an inorganic oxide is made of aluminum oxide, silicon oxide, tin oxide, magnesium oxide,
Alternatively, any material may be used as long as it is made of a vapor-deposited film of an inorganic oxide such as a mixture thereof, and has transparency and a gas barrier property against oxygen, water vapor, and the like. Among them, aluminum oxide and silicon oxide are particularly preferable. However, the thin film layer 3 of the present invention is not limited to the above-mentioned inorganic oxide, but may be any material that meets the above conditions.

Although the optimum conditions for the thickness of the inorganic oxide thin film layer 3 vary depending on the type and constitution of the inorganic compound used, generally the thickness is preferably in the range of 5 to 300 nm, and the value is appropriately selected. However, if the film thickness is less than 5 nm, a uniform film may not be obtained or the film thickness may not be sufficient, and the function as a gas barrier material may not be sufficiently achieved. When the thickness exceeds 300 nm, the thin film cannot maintain flexibility,
There is a possibility that the thin film may be cracked by external factors such as bending and pulling after film formation. Preferably, 10-1
It is in the range of 50 nm.

The inorganic oxide thin film layer 3 is replaced with the transparent primer layer 2
There are various methods for forming the film on the substrate, and the film can be formed by a normal vacuum deposition method, but other thin film forming methods such as a sputtering method, an ion plating method, and a plasma vapor deposition method (CVD) are used. Can also. 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 substrate and 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. In addition, in order to increase the transparency of the deposited film, reactive deposition in which oxygen gas or the like is blown in the deposition may be used.

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

The gas barrier coating layer 4 is mainly composed of an aqueous solution containing a water-soluble polymer and at least one of (a) at least one metal alkoxide and a hydrolyzate or (b) tin chloride, or a water / alcohol mixed solution. And a coating agent. A water-soluble polymer and tin chloride are mixed with water (water or water /
A solution obtained by coating a solution obtained by dissolving with a solvent or a solution obtained by directly treating a metal alkoxide directly or by preliminarily hydrolyzing the solution onto the inorganic oxide thin film layer 3 and drying by heating. It is.
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, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, sodium alginate and the like. In particular, when polyvinyl alcohol (hereinafter referred to as PVA) is used for the coating agent of 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 includes a range from so-called partially saponified PVA in which acetic acid groups remain to several tens% to complete PVA in which only a few% of acetic acid groups remain. Is not particularly limited.

Tin chloride is stannous chloride (SnCl ₂ ),
Stannic chloride (SnCl ₄ ) or a mixture thereof may be used, and either anhydrous or hydrated can be used.

Further, the metal alkoxide is tetraethoxy.
Silane [Si (OC_TwoH_Five)_Four], Triisopropoxy
Aluminum [Al (O-2'-C_ThreeH₇)_Three]
General formula, M (OR)_n(M: Si, Ti, Al, Zr, etc.
Metal, R: CH_Three, C_TwoH _FiveSuch as an alkyl group)
Things. Among them, tetraethoxysilane, triiso
After propoxyaluminum is hydrolyzed,
Is relatively stable in this case.

Each of the above-mentioned components can be added to the coating agent alone or in combination of several components. Further, as long as the gas barrier properties of the coating agent are not impaired, isocyanate compounds, silane coupling agents, dispersants, and stabilizers 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 (TDI), triphenylmethane triisocyanate (TTI) ), Tetramethylxylene diisocyanate (hereinafter, 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, another layer 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 pigments are added to conventionally used ink binder resins such as urethane, acrylic, nitrocellulose, rubber, and vinyl chloride. , A layer composed of an ink to which an additive such as an extender, a plasticizer, a desiccant, a stabilizer and the like are added, and on which characters, pictures, and the like are formed. 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 transparent plastic material 5 is provided as an outer layer in order to increase the breaking strength during sterilization of boiling and retort. In particular, from the viewpoint of mechanical strength and heat stability, biaxially stretched nylon film, biaxially stretched polyethylene terephthalate. It must be a type selected from a film and a biaxially oriented polypropylene film. The thickness is determined according to the material and the required quality, etc.
The range is 30 μm. As a forming method, lamination can be performed by a known method such as a dry laminating method in which two adhesives such as a two-component curable urethane resin are used.

The seal layer 6 is provided as an adhesive layer when forming a bag-like package or the like. 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 their metals A resin such as a crosslinked 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 is common to use a dry laminating method or the like in which a film-like material made of the above resin is bonded using an adhesive such as a two-component curable urethane resin, but all are laminated by a known method. be able to.

[0050]

EXAMPLES The strongly adhered transparent laminate of the present invention will be further described with reference to specific examples.

<Preparation of Composite Solution> A) In a diluting solvent, 24 parts by weight of an acrylic polyol is weighed with respect to 1 part by weight of N-β- (aminoethyl) -γ-aminopropyltriethoxysilane and stirred. Then, a mixed solution obtained by adding TDI as an isocyanate compound so that the NCO group is equal to the OH group of the acrylic polyol is diluted to an arbitrary concentration to obtain a composite solution A.

B) 2- (Epoxycyclohexyl) ethyltrimethoxysilane (hereinafter abbreviated as EETMS) and tetraethoxysilane (Si (OC ₂ H ₅ )) in a diluting solvent
₄ (hereinafter abbreviated as TEOS) mixed with EETMS and T
A weight ratio of 1.25 times the weight of the combined EOS was measured, and a tin chloride (SnCl ₂ ) / methanol solution (prepared to 0.003 mol / g) as a catalyst was combined with the EETMS and the TEOS. 1/400 for things
and stirred. 0.1NH there
After adding Cl and agitating and hydrolyzing, a mixed solution obtained by adding TDI to the OH group of the acrylic polyol so that the NCO group is equivalent to the OH group is diluted to an arbitrary concentration to obtain a composite solution B.

C) In a diluting solvent, TDI is added as an isocyanate compound to the acrylic polyol so as to have an equivalent amount to the OH group of the acrylic polyol.

D) TEOS equivalent to 0.1 part by weight is added to 1 part by weight of the acrylic polyol in the diluting solvent,
After adding 0.1N HCl and stirring to hydrolyze, TDI
Is diluted to an arbitrary concentration of a mixed solution obtained by adding the NCO group to the OH group of the acrylic polyol so as to be an equivalent amount, to obtain a composite solution D.

Example 1 A transparent biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was used as a base film 1, and a composite solution A was gravure-coated on one surface of the film as a transparent primer layer 2. It was formed to a thickness of 0.2 μm by the method. Next, metallic aluminum was evaporated on the transparent primer layer 2 by a vacuum evaporation apparatus using an electron beam heating method, oxygen gas was introduced therein, and aluminum oxide having a thickness of 20 nm was evaporated to form an inorganic oxide thin film layer 3. Further, a coating agent having the following composition was applied thereon with a bar coater and dried at 100 ° C. for 1 minute with a drier to form a gas barrier coating layer 4 having a thickness of 0.3 μm.

For the composition of the coating agent, a liquid and a liquid are distributed.
It was mixed at a combined ratio (wt%) of 60/40.
(Note: Liquid; hydrochloric acid in 10.4 g of tetraethoxysilane
(0.1N) 89.6 g was added and stirred for 30 minutes to add water
Dissolved solid content 3wt% (SiO _TwoHydrolysis)
Liquid Liquid: Polyvinyl alcohol 3wt% water / isop
Propyl alcohol solution (water: isopropyl alcohol weight)
Next, as the transparent plastic material 5 to be the outer layer, the thickness 1
Two-component curing of 5 μm biaxially stretched nylon film (ON)
By dry lamination through urethane adhesive
Laminated, and then a polyolefin-based thermoplastic which is a seal layer 6
40 μm thick low-density polyethylene
Drying the film through a two-component curable urethane adhesive
Laminate by the minate method to obtain the tightly adhered transparent laminate of Example 1.
Obtained.

Example 2 A strongly adhered laminate of Example 2 was obtained in the same manner as in Example 1, except that the composite solution B was used as the transparent primer layer 2.

Example 3 A strongly adhered laminate of Example 3 was obtained in the same manner as in Example 1, except that the composite solution C was used as the transparent primer layer 2.

Example 4 A strongly adhered laminate of Example 4 was obtained in the same manner as in Example 1, except that the composite solution D was used as the transparent primer layer 2.

Comparative Example 1 Comparative Example 1 was performed in the same manner as in Example 1 except that the transparent primer layer 2 was not provided.
Was obtained.

Comparative Example 2 A transparent laminate of Comparative Example 2 was obtained in the same manner as in Example 1, except that the composite solution C was used as the transparent primer layer 2.

Comparative Example 3 A transparent laminate of Comparative Example 3 was obtained in the same manner as in Example 1, except that the composite solution D was used as the transparent primer layer 2.

<Test 1> A four-sided pouch of 150 mm × 200 mm filled with 150 g of water was prepared for each of the four types of transparent laminates of Example 4 and three types of comparative examples, before and after retort sterilization. The oxygen transmission rate, adhesive strength, and the peeled surface (peeled portion) when the substrate was separated from the plastic material were measured and observed by the following methods. The appearance after the retort sterilization treatment was also visually observed. Table 1 shows the results. Retort sterilization conditions: 125 ° C, 30 min. Oxygen permeability: Measured using an oxygen permeability measuring device (manufactured by MOCON). Measurement atmosphere: 30 ° C., 70% RH. Adhesive strength: The adhesive strength between PET and ON was measured using an Instron type tensile tester. Crosshead speed by T-type peeling method; 300 mm / min. Peeled surface: Estimated peeled surface by detecting aluminum element from base film and seal layer with fluorescent X-ray device.

[0064]

[Table 1]

When the results in Table 1 are considered, there is no problem in the adhesiveness and gas barrier properties in any structure before retorting. However, in the results after retorting, Examples 1 to 4 show no deterioration in gas barrier properties and no peeling. It can be seen that the surface is peeled off by the adhesive layer, and that high adhesiveness is maintained. However, when Comparative Examples 1 and 2 are viewed, after the retort, there is a possibility that a peeling phenomenon occurs and appearance defects occur. It can be seen from the peeled surface that the adhesion between the substrate and the vapor deposition layer is insufficient. Therefore, those of Examples 1 to 4 are higher than those of Comparative Examples 1 and 2 in that they have a high gas barrier property that blocks gas and the like that affect the contents, and there is no deterioration of the gas barrier property even after retorting, and the occurrence of delamination and the like. It can be said that all the retort resistances are satisfied.

[0066]

As described above, according to the present invention, it is possible to obtain a versatile packaging material having excellent transparency and a high gas barrier property comparable to that of an aluminum foil. Because of its excellent retort sterilization suitability, it can be widely used in the field of packaging.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a strongly adhered transparent laminate of the present invention.

[Explanation of symbols]

 1 Base film 2 Transparent primer layer 3 Inorganic oxide thin film layer 4 Gas barrier coating layer 5 Transparent plastic material 6 Seal layer

Front page of the continued F-term (reference) 4F100 AA05D AA17C AA18C AA19C AA20C AH06B AH08D AK01D AK01E AK03E AK07E AK21D AK42E AK48E AK51B AK52B AR00B AR00E AT00A BA05 BA07 BA10E BA13 CB00 CC00D EH66C EJ38E GB15 GB23 GB66 JA20B JA20C JB09D JC00 JD02 JJ03 JL12E JM02C JN01B JN01E YY00B YY00C

Claims (8)

[Claims] 1. A transparent primer layer, a vapor-deposited thin film layer made of an inorganic oxide having a thickness of 5 to 300 nm, a water-soluble polymer, and (a) one or more metal alkoxides and a hydrolyzate thereof on at least one surface of a substrate film. A decomposition agent or (b) a coating agent mainly composed of an aqueous solution containing at least one of tin chloride or a water / alcohol mixed solution is applied, and a gas barrier coating layer formed by heating and drying is sequentially laminated, and further via an adhesive layer. A transparent plastic material, and further, a polyolefin-based thermoplastic resin is laminated as a seal layer via an adhesive layer on the opposite side of the substrate film on which the transparent primer layer is provided, wherein the transparent laminate is strongly adherent. 2. The strongly adherent transparent laminate according to claim 1, wherein said transparent plastic material is one selected from a biaxially stretched nylon film, a biaxially stretched polyethylene terephthalate film, and a biaxially stretched polypropylene film. 3. The method according to claim 1, wherein the transparent primer layer comprises a silane coupling agent or a hydrolyzate of the silane coupling agent.
2. A transparent primer layer comprising a composite with a polyol and an isocyanate compound.
3. The strongly adherent transparent laminate according to any one of claims 1 to 2. 4. The strongly adherent transparent laminate according to claim 1, wherein said silane coupling agent contains a functional group which 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
The strongly adherent transparent laminate according to any one of claims 1 to 4, wherein the thickness is from 2 to 2 µm. 6. The strongly adhered transparent laminate according to claim 1, wherein the inorganic oxide is aluminum oxide, silicon oxide, magnesium oxide, or a mixture thereof. 7. The method according to claim 1, wherein said metal alkoxide is tetraethoxysilane or triisopropoxyaluminum, or a mixture thereof.
The strongly adhered transparent laminate according to the above. 8. The strongly adherent transparent laminate according to claim 1, wherein said water-soluble polymer is polyvinyl alcohol.