JP2001293814A - Gas barrier laminate excellent in stiffness strength and impact resistance, having shading properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging material enhanced in stiffness strength and excellent in impact resistance by forming a sandwich structure from resin layers and to provide gas barrier laminate excellent in shading properties, friendly to environment and excellent in gas barrier properties by applying metal vapor deposition to at least the single surface of an intermediate layer constituting the sandwich structure. SOLUTION: The gas barrier laminate excellent in stiffness strength, impact resistance and shading properties, which comprises three or more resin layers wherein the intermediate layer having metal vapor deposition applied to at least the single surface thereof is used, has the sandwich structure wherein three or more adjacent layers consist of the single-layered or laminated intermediate layer and two surface material layers holding the intermediate layer and the elastic modulus of the resins same or different in kind used in the surface material layers holding the intermediate layer is larger than that of the resin used in the intermediate 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 non-foodstuffs such as foodstuffs, medical products and electronic components, and more particularly to a packaging material having excellent waist strength and impact resistance. In addition, the present invention relates to a packaging material having further excellent light shielding properties and gas barrier properties.

[0002]

2. Description of the Related Art Waist strength of a film in a packaging material is an important factor in terms of suitability for a packaging machine and maintenance of a packaging form at a store. Generally, when the stiffness is increased, the thickness is increased or stretched in the case of a single body. In the case of polyethylene or the like, it is generally used in place of high density polyethylene. In order to increase the waist strength by laminating or the like, measures such as laminating the film with a stretched film of nylon, polyester, polypropylene or the like are taken. Further, there is a case where a paper is laminated to give a waist strength.

[0003] However, when the thickness is increased, the cost is correspondingly increased, which is not desirable. When the film is stretched, it is often limited by the physical properties of the resin. Further, in the case of polyethylene, when the density is high, the impact resistance becomes poor, so it is difficult to balance the waist strength and the impact resistance. Further, when the required stiffness is increased even when the stiffener is bonded to the base material, it is not sufficient to simply laminate the base materials, and eventually the stiffness of the laminated resin layer itself is required.

[0004] Further, necessary conditions for use as a packaging material include light shielding properties and gas barrier properties. These are indispensable items for suppressing deterioration of the contents filled in the packaging material and maintaining their functions and properties.

In general, a metal foil made of a metal such as aluminum has been mainly used as a material having both a light shielding property and a gas barrier property. However, although metal foil has excellent light-shielding properties and gas barrier properties, it has problems such as the inability to use metal detectors for inspections and the disposal of incombustibles when disposed after use. There is a tendency that it is difficult to use it in the rise of.

[0006]

That is, as the conditions used as a packaging material in such a case, excellent stiffness and impact resistance for providing rigidity, light-shielding properties and excellent gas barrier properties, and environmental protection However, there is no packaging material that satisfies all of them at present.

The present invention is to solve the above-mentioned problems of the prior art, and provides a packaging material having high waist strength and excellent impact resistance by forming a sandwich structure with a resin layer. It is another object of the present invention to provide a laminated body which is excellent in light-shielding properties, is easy to use in an environment, and is excellent in gas barrier properties by performing metal vapor deposition on at least one surface of an intermediate layer constituting a sandwich structure.

[0008]

In order to achieve the above object, the present invention firstly comprises a resin layer comprising three or more resin layers in which an intermediate layer metal-deposited on at least one side is used. In the laminate, three or more adjacent layers have a sandwich structure consisting of a single layer or a laminated intermediate layer and two face material layers sandwiching the intermediate layer. Gas barrier laminate with excellent waist strength and excellent shock resistance, characterized in that the elastic modulus of the same or different resin used is greater than the elastic modulus of the resin used in the intermediate layer. It is.

According to a second aspect of the present invention, there is provided a laminate comprising three or more resin layers in which an intermediate layer metal-deposited on at least one side is used. It has a sandwich structure consisting of a layer or a laminated intermediate layer and two face material layers sandwiching the intermediate layer, and the elastic modulus (E1, E1) of the same or different resin used for the face material layer sandwiching the intermediate layer. E3) is obtained from the elastic modulus (E2) of the resin used for the intermediate layer by the elastic modulus ratio (E1 / E2,
E3 / E2), which is 1.2 times or more larger than the above, and is a light-shielding gas barrier laminate excellent in waist strength and impact resistance.

According to a third aspect of the present invention, the thickness of the resin used for the intermediate layer is larger than the thickness of the resin layer of the face layer. And a gas barrier laminate having a light-shielding property with excellent impact resistance.

According to a fourth aspect of the present invention, the light-shielding property excellent in waist strength and impact resistance according to any one of the first to third aspects is characterized in that the deposited metal is aluminum. It is a gas barrier laminate having the same.

According to a fifth aspect of the present invention, at least one of the face material layers includes a gas barrier film, and the waist strength and impact resistance according to any one of the first to fourth aspects of the present invention. It is a gas barrier laminate having excellent light shielding properties.

According to a sixth aspect of the present invention, the gas barrier film is formed by laminating a vapor-deposited thin film layer made of an inorganic oxide with a thickness of 5 to 300 nm on at least one surface of a base material made of a plastic material. The gas-barrier laminate according to claim 5, which is excellent in waist strength and impact resistance and has a light-shielding property.

According to a seventh aspect of the present invention, the inorganic oxide is selected from the group consisting of aluminum oxide, silicon oxide, magnesium oxide, and mixtures thereof. It is a gas barrier laminate having excellent light shielding properties.

According to a further aspect of the present invention, a gas barrier coating layer is further laminated on the vapor-deposited thin film layer made of the inorganic oxide, wherein the gas barrier coating layer comprises a water-soluble polymer, ) A layer formed by applying a coating agent mainly containing an aqueous solution or a mixed solution of water / alcohol containing at least one of a metal alkoxide and a hydrolyzate thereof and (b) tin chloride, and drying by heating. The gas barrier laminate according to any one of claims 6 to 7, which is excellent in waist strength and impact resistance and has a light-shielding property.

According to a ninth aspect of the present invention, the metal alkoxide is tetraethoxysilane, triisopropoxyaluminum, or a mixture thereof, and is excellent in waist strength and impact resistance. And a gas barrier laminate having a light-shielding property.

According to a tenth aspect of the present invention, the water-soluble polymer is polyvinyl alcohol, and the light-shielding gas-barrier laminate excellent in waist strength and impact resistance is provided. It is.

[0018] In the invention according to claim 11, the gas barrier film is formed by laminating a composite thin film layer mainly composed of an inorganic layered mineral and a water-soluble polymer on at least one surface of a base material made of a plastic material. The gas-barrier laminate according to claim 5, which is excellent in waist strength and impact resistance and has a light-shielding property.

According to a twelfth aspect of the present invention, the composite thin film layer further comprises a metal alkoxide or a hydrolyzate thereof, which is excellent in waist strength and impact resistance. And a gas barrier laminate having a light-shielding property.

According to a thirteenth aspect of the present invention, the water-soluble polymer is a polyvinyl alcohol-based resin or a derivative thereof, wherein the light-shielding property is excellent in waist strength and impact resistance. It is a gas barrier laminate having:

According to a fourteenth aspect of the present invention, there is provided the gas barrier laminate according to the eleventh aspect, wherein the inorganic layered mineral is montmorillonite and has a light-shielding property excellent in waist strength and impact resistance. .

Further, in the invention according to claim 15, the interlayer distance of the inorganic layered mineral in the composite thin film layer is 1 to the interlayer distance of the inorganic layered mineral alone before forming the composite thin film layer with the water-soluble polymer. The gas-barrier laminate according to any one of claims 11 and 14, wherein the gas-barrier laminate has excellent waist strength and excellent impact resistance.

[0023]

According to the present invention described above, it is possible to impart both excellent waist strength and excellent impact resistance to a packaging material from a sandwich structure composed of hard / soft / hard layers. Furthermore, since metal deposition is performed on at least one surface in the middle of the sandwich structure, it is possible to provide a highly practical packaging material having excellent gas barrier properties, light shielding properties and environmental suitability.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a gas-barrier laminate having a light-shielding property with excellent waist strength and impact resistance according to the present invention.

First, a gas-barrier transparent laminate excellent in waist strength and impact resistance according to the present invention in FIG. 1 will be described. In the embodiment shown in FIG. 1, the sandwich structure has a three-layer structure of hard / soft / hard layers which are characteristic features of the sandwich structure. In the figure, reference numerals 1 and 4 denote face material layers which form a hard layer in the sandwich structure. Depending on the quality, a gas barrier film may be used for this layer. Reference numeral 2 denotes an intermediate layer forming a soft layer in the sandwich structure, and reference numeral 3 denotes a metal deposition layer formed on one surface of the intermediate layer 2.

Hereinafter, the sandwich structure which is a feature of the present invention will be described in more detail. The sandwich structure is basically composed of two face material layers (face material layer 1 and face material layer 4).
Are laminated and bonded with an intermediate layer 2 having another type or another function interposed therebetween.
And the intermediate layer 2 is a thicker and softer material layer than the face material layers 1 and 4,
It is a structure that can expect new functions as a whole. Also,
The intermediate layer 2 may be a laminated body. The face material layers 1 and 4 for sandwiching may be made of the same material or different materials.

Since this structure is particularly lightweight and highly rigid due to its combined effect, it can be used for aircraft, ships, automobiles, tanks,
It is widely used in fields such as architecture. In this field, materials used for sandwich structures include:
Aluminum alloys are most commonly used for the face material layers 1 and 4, and metallic materials such as steel plates, titanium alloys, and magnesium alloys, nonmetallic materials such as woody materials and inorganic materials, and reinforced plastics are used.

As the intermediate layer 2 (core material), an aluminum alloy,
Stainless steel or titanium alloy is used in the form of honeycomb, or porous ceramics, foam glass, wood, paper, etc. are used, but the most frequently used core materials are phenolic resin, epoxy resin, polyurethane, and polystyrene. Plastics such as polyvinyl chloride, acrylic resin and the like which increase the bulk occupy a large field.

In the plastic film field, particularly in the packaging material field, attempts have been made to improve waist strength and impact resistance by laminating various layers. However, improvement utilizing a composite effect such as a sandwich structure has been carried out until now. Not done.

In the present invention, a resin having a higher elasticity than the intermediate layer 2 of the same or different type is used for the face layers 1 and 4, the laminated film has a stiffness, and the intermediate layer 2 has a single layer having an impact strength. Alternatively, the laminated film is provided with impact strength by providing a multilayer resin layer.

The elastic modulus defined in the present invention is a Young's modulus. In addition, the elastic modulus of a film or a sheet can be adopted as an alternative characteristic as long as it shows rigidity, and may be a tensile elastic modulus or a bending elastic modulus. In addition, a stiffness, such as a loop stiffness, may be used as long as it is a scale that indicates stiffness instead of an elastic modulus.

The resin formed on the face material layers 1 and 4 has a high elastic modulus, rigidity and waist strength, and is a resin layer formed to satisfy the target waist strength of the film. Any resin may be used as long as it satisfies the waist strength. From the theory of the sandwich structure, the resin layer formed on the face material layers 1 and 4 has a higher elastic modulus than the resin layer formed on the intermediate layer 2. It is preferable that the resin is generally a resin such as polyethylene, polypropylene, nylon, polyvinyl chloride, polyester, or polyvinyl alcohol used for the film, and there is no need to particularly limit the type of the resin. No problem.

That is, if the resin layers formed on the face material layers 1 and 4 are made of a resin having a higher elastic modulus, a higher rigidity, and a higher waist strength than the resin layer formed on the intermediate layer 2, a normal resin can be used. The rigidity of the film is increased as compared with a laminating method and a resin having a large elastic modulus, and a stiff film can be obtained.

The strength ratio such as the elastic modulus and the stiffness used for the face layers 1 and 4 with respect to the intermediate layer 2 may be large, but is preferably 1.2 times or more, preferably 2 times or more.

The resin formed on the intermediate layer 2 has a high impact strength and is a resin layer formed to satisfy the required quality of the target impact strength of the film, and satisfies the target impact strength of the film. It is sufficient if the resin is used, and it is not particularly necessary to limit the type of the resin from the sandwich configuration of the present invention.However, it is necessary to provide a metal deposition layer to be described later on at least one surface thereof in order to impart light shielding properties and gas barrier properties. .

The intermediate layer 2 may have a laminated structure, and a recycled material or a cheap material may be laminated.

At this time, as the elastic modulus of the laminated material, an average value obtained by dividing the sum of the elastic modulus of the constituent materials × the film thickness by the film thickness of the intermediate layer 2 may be used as a representative value. What is necessary is just to be smaller than the elastic modulus of the material layer. More preferably, the elastic modulus of the two face material layers 1 and 4 is smaller than the smaller one.

The thickness of the laminated film in the present invention is such that the thickness of the resin used for the adjacent three intermediate layers 2 is greater than the thickness of each of the resin layers of the face layers 1 and 4 sandwiching the intermediate layer. It is more preferable to increase the impact strength of the laminated film. That is, the impact strength is increased by increasing the thickness of the intermediate layer 2 to be laminated to increase the impact strength.

The sandwich structure will be described with reference to a more specific example. Polyolefin resins, such as polyethylene and polypropylene, differ greatly in resin's impact strength or elastic modulus, that is, waist strength and rigidity, depending on the density of the resin. A laminate can be formed. For this purpose, it is sufficient that the density is higher than that of the intermediate layer 2 which is a layer between which the face material layers 1 and 4 to be sandwiched are sandwiched. More preferably, a density difference of at least 0.015 or more is provided between the laminated structures. .

More specifically, high-density polyethylene or polypropylene, which is rigid and tends to have low impact strength, is used for the face layers 1 and 4, and low-density polyethylene, which has impact strength and tends to be soft, is used for the intermediate layer 2. It is only necessary to form the structure of the present invention as a sandwich, the difference in density between high-density polyethylene or polypropylene and low-density polyethylene depends on the physical properties of the film required, and in some cases the difference in density may be as small as possible. 0.
It is preferably at least 015.

The polypropylene-based resin is not particularly limited, such as homopolypropylene and polypropylene copolymerized with ethylene, but may be any polypropylene having a higher elastic modulus than the polyethylene of the intermediate layer 2 to be sandwiched.

Further, a sandwich structure may be formed only with a polypropylene-based resin. Homopolypropylene is used as a polypropylene having a high elastic modulus and stiffness, and block copolymerized polypropylene is used as a polypropylene having a high impact strength. In order to form the configuration of the present invention, a configuration in which a block polypropylene is sandwiched between homopolypropylenes or the like can be considered.

When the resins forming the sandwich structure are different kinds of resins and the respective layers are not completely bonded, it is difficult to obtain a resin laminated film having excellent rigidity and impact strength according to the present invention. It must be completely bonded via an agent or an adhesive resin.

The metal deposition layer 3 provided on at least one side of the intermediate layer 2 for the purpose of imparting light-shielding properties and gas barrier properties to the laminate of the present invention will be described in detail. The metal deposition layer 3 formed in the present invention does not need to be particularly limited as long as it can impart gas barrier properties and light-shielding properties. However, considering the above properties and workability, aluminum, titanium, copper, etc. It is preferable to provide a deposited film of, and among them, aluminum is particularly preferable.

As a method for forming a vapor-deposited thin film layer made of metal on the intermediate layer 2, various methods such as a vacuum vapor deposition method, a sputtering method, an ion plating method, and an electron beam method can be used. Considering the above, it is more preferable to use the vacuum deposition method at present. As a heating means of a vacuum deposition apparatus by a vacuum deposition method, an electron beam heating method, a resistance heating method, an induction heating method, or the like is 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, It is also possible to use an ion beam assist method.

Although the optimum conditions for the thickness of the metal deposition layer 3 vary depending on the type and configuration of the metal used, it is generally 10
The range is desirably in the range of ~ 300 nm, and the value is appropriately selected. However, if the film thickness is less than 10 nm, a uniform film may not be obtained, or the film thickness may not be sufficient, and gas barrier properties or light blocking properties may not be provided. 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. Preferably, it is in the range of 20 to 100 nm.

Next, the gas barrier film used for the face material layer according to the required quality of the gas barrier property will be described. The gas barrier film used in the present invention is not particularly limited as long as the required gas barrier properties can be imparted. Usually, a vapor-deposited thin film layer 6 made of an inorganic oxide is laminated on a plastic substrate 5 as shown in FIG. What you did,
As shown in FIG. 3, a laminated thin film layer 10 composed of a water-soluble polymer and an inorganic layered mineral is often used.

The gas barrier film used in the present invention will be described in more detail. The above-mentioned substrate 5 is a plastic material, for example, a polyester film such as polyethylene terephthalate (PET) and polyethylene naphthalate, a polyolefin film such as polyethylene and polypropylene, a polystyrene film, a polyamide film, a polyvinyl chloride film, a polycarbonate film, and a polyacryl. A nitrile film, a polyimide film, or the like is used, which may be stretched or unstretched, and a film having mechanical strength and dimensional stability is preferred. These are processed into a film and used. Among these, a polyethylene terephthalate film or a polypropylene film 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 substrate 5 in order to improve the adhesion to the thin film. In addition, corona treatment as pretreatment,
Low-temperature plasma treatment or ion bombardment treatment may be performed, and furthermore, chemical treatment, solvent treatment, or the like may be performed.

Although the thickness of the substrate 5 is not particularly limited, it is suitable as a packaging material, other layers may be laminated, the deposited thin film layer 6 made of an inorganic oxide or a water-soluble high layer. Considering the processability when forming the composite thin film layer 10 composed of molecules and inorganic layered minerals and the gas barrier coating layer 7, it is practically preferably in the range of 3 to 200 μm, and more preferably 6 to 30 μm depending on the application.

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

Next, the case where the deposited thin film layer 6 made of an inorganic oxide is laminated on the substrate 5 will be described in detail. The deposited thin film layer 6 made of an inorganic oxide includes aluminum oxide,
Any material may be used as long as it is made of a deposited film of an inorganic oxide such as silicon oxide, tin oxide, magnesium oxide, or a mixture thereof and has a gas barrier property against oxygen, water vapor, or the like. Among them, aluminum oxide and silicon oxide are particularly preferable because of their excellent oxygen permeability and water vapor permeability. However, the thin film layer of the present invention is not limited to the inorganic oxide described above,
Any material that meets the above conditions can be used.

The optimum conditions for the thickness of the vapor-deposited thin film layer 6 vary depending on the type and constitution of the inorganic compound used, but 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. 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. Preferably, it is in the range of 5 to 100 nm.

The deposited thin film layer 6 made of an inorganic oxide is
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 a vacuum deposition apparatus by a vacuum deposition method, an electron beam heating method, a resistance heating method, an induction heating method, or the like is 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, It is also possible to use an ion 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.

Further, another layer can be laminated on the vapor-deposited thin film layer 6. For example, it is a gas barrier coating layer 7 or the like provided to provide a high gas barrier property comparable to a metal foil.

The gas barrier coating layer 7 for achieving the above object contains a water-soluble polymer and at least one of (a) one or more metal alkoxides and hydrolysates, or (b) tin chloride. It consists of a coating agent whose main component is an aqueous solution or a water / alcohol mixed solution. 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 metal alkoxide is directly or preliminarily hydrolyzed. It must be formed by coating and heating and drying a thin film layer made of an oxide. 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 for the coating agent of the laminate of the present invention, the gas barrier property is most excellent, and thus it is preferable. 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 an anhydride or a hydrate can be used.

The metal alkoxide is represented by a general formula such as tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ], triisopropoxy aluminum [Al (O-2′-C ₃ H ₇ ) ₃ ], M (OR) _n (M: metal such as Si, Ti, Al, Zr, R: alkyl group such as CH ₃ , C ₂ H ₅ ). Among them, tetraethoxysilane and triisopropoxyaluminum are preferable because they are relatively stable in an aqueous solvent after hydrolysis.

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 for applying the coating agent, conventionally known means such as a commonly used dipping method, roll coating method, screen printing method, spray method, gravure printing method and the like can be used. The thickness of the coating varies depending on the type of the coating agent, the processing machine, and the processing conditions. When the thickness after drying is 0.01 μm or less, it is not preferable because a uniform coating film cannot be obtained and a sufficient gas barrier property cannot be obtained. On the other hand, when the thickness exceeds 50 μm, there is a problem because cracks are easily generated in the film. It is preferably in the range of 0.01 to 50 μm,
More preferably, it is in the range of 0.1 to 10 μm.

Next, the case where the composite thin film layer 10 composed of a water-soluble polymer and an inorganic layered mineral is laminated on the substrate 5 will be described in detail. The purpose of this composite thin film layer 10 is to provide gas barrier properties and suppress temperature dependency and humidity deterioration. To achieve the above object, the composite thin film layer 10
Is a composite film 1 of a water-soluble polymer and an inorganic layered mineral.
0, and the interlayer distance of the inorganic layered mineral is 1.2 times or more, more preferably 2 times or more the interlayer distance of the inorganic layered mineral alone before the formation of the composite coating with the water-soluble polymer.
More preferably, the magnification is twice or more.

This interlayer distance can be calculated by obtaining the bottom reflection (001 plane) of the inorganic layered mineral in the composite coating 10 by the X-ray diffraction method. That is, according to the calculation based on the X-ray diffraction method, the interlayer distance of the above-mentioned inorganic layered mineral before being mixed with the water-soluble polymer differs depending on the type of the inorganic layered mineral and the type of the water-soluble polymer, but usually 7 to 15Å
Becomes On the other hand, the interlayer distance of the inorganic layered mineral in the composite film 10 of the present invention is 1.2 times or more thereof, and those having more preferable gas barrier properties are 2 times or more.

In the present invention, the inorganic layered mineral and the water-soluble polymer are not merely mixed and dispersed in the composite thin film layer 10 but are so dispersed that the water-soluble polymer expands between the layers of the inorganic layered mineral. And the inorganic layered mineral and the water-soluble polymer are complexed at the molecular level. For this reason, it is considered that the composite thin film layer 10 has excellent gas barrier properties and can suppress humidity deterioration and temperature dependency.

The composite thin film layer 10 will be described in more detail. The inorganic layered mineral in the composite thin film layer 10 refers to a crystalline inorganic compound having a layered structure, such as kaolinite, halloysite, chlorite, smectite, vermiculite, pyrophyllite, and mica. Natural clay minerals, and synthetic products such as synthetic smectite. As long as it is an inorganic layered mineral,
The type, particle size, aspect ratio, and the like can be appropriately selected depending on the desired required quality and the like, and are not particularly limited. However, the swelling property is high, and the water-soluble polymer component enters between the layers of the layered structure, and the interlayer is formed. The inorganic layered mineral of the smectite group is suitable because an enlarged composite thin film layer can be easily obtained. Specific examples of the smectite group include montmorillonite, saponite, and the like. Among them, montmorillonite is more preferable in terms of swelling property, dispersibility, price, workability, and the like.

On the other hand, the water-soluble polymer which is another component of the formation of the composite thin film layer 10 is not particularly limited as long as it is compatible with the inorganic layered mineral and easily penetrates between the layers. And polyvinyl alcohols such as ethylene-vinyl alcohol copolymer or derivatives thereof, saccharides such as cellulose and starch,
Polymers and derivatives such as polyacrylic acid and methacrylic acid can be used. Further, judging from the viewpoint of gas barrier development, a polyvinyl alcohol resin or a derivative thereof is more preferable.

The polyvinyl alcohol resin is a generic term for polymers having hydroxyl groups by polymerization and saponification (alkali treatment) of vinyl acetate. The degree of saponification is not particularly limited, and acetic acid groups are several tens. % From partially saponified polyvinyl alcohol remaining to completely saponified polyvinyl alcohol having only a few percent of acetic acid groups remaining, from 1 to 40 mo
A wide range of ethylene-vinyl alcohol copolymers containing about 1% ethylene can be used.

A known method can be used for mixing the inorganic layered mineral and the water-soluble polymer, and is not particularly limited. Although the value of the compounding ratio varies depending on the required quality, it is usually 1:99 to 9 by weight ratio of the inorganic layered mineral to the water-soluble polymer.
It is preferably in the range of 0:10.

In the formation of the composite thin film layer, the interlayer distance of the inorganic layered mineral in the composite thin film layer 10 is adjusted by adjusting the combination of the inorganic layered mineral to be used and the water-soluble polymer, the mixing ratio, the heating temperature during mixing, and the like. Can be appropriately selected.

Further, other components can be added to the composite thin film layer 10. For example, a metal alkoxide or a hydrolyzate thereof added for the purpose of further improving the temperature-humidity dependence of gas barrier properties, film strength, and water resistance.

The above-mentioned metal alkoxide is represented by the general formula M (O
R) _n (M is a metal element such as Si, Al, Ti, etc., and R is a lower alkyl group having 1 to 4 carbon atoms), such as tetraethoxysilane or triisopropoxyaluminum. Can be used. Also,
As these hydrolysates, both those in which a part of the alkoxide groups are hydrolyzed and those in which all of the alkoxide groups are hydrolyzed can be used.

In the case of obtaining a composite thin film layer containing the above-mentioned metal alkoxide hydrolyzate, the metal alkoxide hydrolyzate is added to the composite liquid obtained by mixing the inorganic layered mineral and the water-soluble polymer. May be added. In this case, the amount of addition is 1 to the composite liquid in terms of water resistance and flexibility.
It is preferably set to 〜80%.

The thickness of the composite thin film layer 10 is generally preferably such that the thickness after drying is in the range of 0.01 to 50 μm, more preferably 0.1 to 50 μm.
It is within a range of 5 μm. When the thickness is less than 0.01 μm, it is difficult to obtain a uniform coating film. On the other hand, when the thickness is more than 50 μm, the film is liable to be broken, which is uneconomical.

It is also possible to provide an undercoat layer 9 in order to improve the adhesion between the substrate 5 and the composite thin film layer 10. For example, a polyurethane-based resin can be used, and it is more preferable to add a surfactant to the polyurethane-based resin in order to adapt to a wider range of base materials of plastic materials.

The polyurethane resin is not particularly limited as long as it has a urethane bond in the main chain or side chain. Examples of the polyurethane resin include those having a urethane bond in the main chain or side chain, as well as polyester polyols and the like. It is also possible to form a urethane bond by reacting a polyol such as polyether polyol or acrylic polyol with an isocyanate compound having an isocyanate group. Among them, a polyurethane resin obtained by mixing a polyester polyol such as a condensation-based polyester polyol or a lactone-based polyester polyol with an isocyanate compound such as tolylene diisocyanate, hexamethylene diisocyanate, or xylene diisocyanate is preferred because it has the best adhesion.

A known method can be used for mixing both, and is not particularly limited. The blending ratio is not particularly limited, but if the amount of the isocyanate compound is too small, curing failure may occur. Therefore, preferably, the OH group derived from the polyol and the NCO group derived from the isocyanate compound are equivalent to 1: 0. 5 to 1:40.

The above-mentioned surfactant is a general term for an organic composition having a lipophilic group and a hydrophilic group, and has the effect of joining the opposite properties of hydrophilicity and lipophilicity. Emulsifier, dispersant, antistatic agent, lubricant,
It is used in pigment dispersants, various catalysts, and the like. Surfactants are classified into anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants depending on the type of hydrophilic group. By adding these to the polyurethane-based resin, the surface of the adhesion layer is modified to be hydrophilic, which is effective in forming a gas barrier coating layer. In consideration of economy, a cationic surfactant such as an amine or a pyridine derivative, which can provide a sufficient effect with a small amount of addition, is more preferable.

The reason why the cationic surfactant exerts its function sufficiently even in a small amount is that the surface of the silicic acid tetrahedral layer on the side where the surface area of the inorganic layered mineral, which is a component of the composite thin film layer, is large is negatively charged. When the cationic surfactant charges the surface of the undercoat layer with a positive charge (cation), the inorganic layered mineral in the composite thin film layer is formed in a state of being oriented parallel to the interface of the undercoat layer. It is thought that it is.

Regarding the addition amount of the surfactant, the mixing ratio of the polyurethane resin component / the surfactant is 10% by weight.
The range of 000/1 to 10/1 is preferred. 10,000 /
If it is less than 1, no effect on the formation of the film can be seen, and if it is more than 10/1, it reacts with the isocyanate compound in the solution before coating to form a precipitate or the like, and the surfactant is relatively expensive. This is because it lacks economic efficiency.

The thickness of the undercoat layer 9 is not particularly limited. However, if the thickness is less than 0.001 μm, the adhesion effect and the effect of forming a film with a surfactant are weakened, and if it is 1 μm or more, it is uneconomical. Generally 0.001
In the range of 1 μm, it is practically preferable that the thickness be 0.05 to 0.5 μm. The drying method is not particularly limited, and a normal method or the like may be used.

Undercoat layer 9 and composite thin film layer 10
As a method for forming a film, a usual coating method can be used. For example, dipping method, roll coating,
Gravure coat, reverse coat, air knife coat,
A comma coat, a die coat, a screen printing method, a spray coat, a gravure offset method, or the like can be used. The coating is applied to at least one surface of the substrate by using these coating methods. In this case, the undercoat layer 9 and the composite thin film layer 10 may be separately provided, or both layers may be simultaneously provided using a multicolor gravure printing machine or the like. Considering the cost, it is more preferable to form them at the same time.
The drying method is not particularly limited, such as hot air drying, hot roll drying, and infrared irradiation.

Further, the above-mentioned face material layers 1, 4 and face material layer 1,
It is also possible to laminate other layers on the gas barrier layer surface of the gas barrier film used in 4, or on the opposite surface.
For example, a printed layer, an outer substrate, and an intermediate substrate. The printing layer is
It is formed for practical use as a packaging bag, etc., and various pigments can be added to conventionally known ink binder resins such as urethane-based, acrylic-based, nitrocellulose-based, polyamide-based, and polyvinyl chloride-based. A layer composed of an ink to which additives such as a vehicle, a plasticizer, a desiccant, a stabilizer and the like are added, in which characters, patterns, and the like are formed. As a forming method, for example, a known printing method such as an offset printing method, a gravure printing method, and a silk screen printing method can be used. Thickness is 0.1 ~
It is appropriately selected within a range of 2.0 μm.

The outer base material and the intermediate base material are provided to obtain a more functional packaging material. Generally, polyethylene terephthalate (PET) is used in view of mechanical strength.
Polyester films such as polyethylene naphthalate and the like, polyolefin films such as polyethylene and polypropylene, polyamide films, polycarbonate films, polyacrylonitrile films, polyimide films and the like are preferably used, especially polyethylene terephthalate films arbitrarily stretched biaxially, A polypropylene film or the like is more preferable.

The thickness is determined according to the material and the required quality. Generally, the thickness can be used within the range of 5 to 50 μm, but it is used within a range where the sandwich structure which is a feature of the present invention does not collapse. It is essential. In addition, as a forming method, lamination can be performed by a known method such as a dry laminating method, a non-solvent laminating method, or an extrusion laminating method, in which an adhesive such as a two-component curable urethane resin is used.

It is also possible to form and laminate a heat-sealing layer on one of the face material layers 1 and 4 or on the outside of that layer. The heat seal layer is used for an adhesive portion when forming a bag-like package or the like. For example, polyethylene, polypropylene, ethylene-polyvinyl alcohol copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid Resins such as an ester copolymer, an ethylene-acrylic acid copolymer, an ethylene-acrylic acid ester copolymer, and a metal crosslinked product thereof are used. The thickness is determined according to the purpose, but is generally 5 to 200.
It can be used in the range of μm. However, the thickness must be used within a range that does not break the sandwich structure which is a feature of the present invention.

As a method for forming the heat seal layer, a film-like material made of the above-mentioned resin may be wet-cured with one liquid,
Dry lamination method of bonding with liquid reaction-curing urethane adhesive, non-solvent type dry lamination method of bonding with non-solvent adhesive, heat-melt thermoplastic resin such as polyethylene, and extrude to bond in a curtain shape Any of a lamination method and a co-extrusion lamination method can be formed by a known lamination method.

The gas barrier laminate of the present invention having a light-shielding property with excellent waist strength and impact resistance will be further described with reference to specific examples.

Example 1 The thickness of the intermediate layer 2 was 30 μm.
Linear low density polyethylene A (MI = 4, density = 0.9
05, tensile modulus = 105 MPa), and 10 μm thick linear low density polypropylene B (MI = 2.
5) is formed into a film by a co-extrusion method, and further, as a metal-deposited thin film layer 3 on the intermediate layer 2, metal aluminum is evaporated by a vacuum deposition device using a resistance heating method, and a 40 nm-thick aluminum-deposited thin film layer is formed. Was formed.

Further, a biaxially stretched polypropylene film having a thickness of 20 μm was laminated as a face material layer 1 on the metal-deposited thin film layer 3 via a two-component curable urethane-based adhesive by a dry lamination method. Thus, a gas-barrier laminate having excellent light-shielding properties and excellent impact resistance was obtained.

<Example 2> In Example 1, the face material layer 1
On at least one surface of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm, metal aluminum was evaporated by a vacuum evaporation apparatus using an electron beam heating method, and oxygen gas was introduced therein, thereby forming a 15 nm-thick aluminum oxide evaporated thin film layer 6. Except for using the provided one, a gas barrier laminate having a light-shielding property excellent in waist strength and impact resistance of the present invention was obtained in the same manner.

<Example 3> In Example 2, the face material layer 1 was used.
Similarly, a light-shielding film having excellent waist strength and impact resistance according to the present invention is formed, except that a coating agent having the following composition is further formed as a gas barrier coating layer 7 on the surface of the deposited thin film 6 by a gravure coating method at a thickness of 0.5 μm. A gas barrier laminate having properties was obtained.

The composition of the coating agent is a mixture of the liquid and the liquid in a mixing ratio (wt%) of 60/40. (note:
Hydrochloric acid (0.1N) 8 in 10.4 g of tetraethoxysilane
9.6 g was added, 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 ). A 3 wt% solution of polyvinyl alcohol in water / isopropyl alcohol (weight ratio of water: isopropyl alcohol 90: 1)
0))

<Example 4> In Example 1, the face material layer 1 was used.
On one side of a biaxially oriented polypropylene film having a thickness of 20 μm, a coating liquid A (see below) was passed as an undercoat layer 9 by an gravure coating method at 80 ° C. in an oven at an application amount of 0.1 (g / m ² ). Is formed, and the coating solution B (see below) is passed through an oven at 80 ° C. by a gravure coating method as a composite thin film layer 10 so that the coating amount is 0.5
(G / m ² ), except that a gas-barrier laminate having excellent waist strength and impact resistance and having a light-shielding property was obtained in the same manner as described above, except that a laminate having (g / m ² ) was used.

<Adjustment of Coating Solution for Undercoat Layer 9> 1) Polyester polyol as a main component (molecular weight of about 200
00), a tolylene diisocyanate (TDI) as an isocyanate compound was further added to a polyurethane resin component in which the NCO groups derived from the isocyanate compound were mixed with the OH groups derived from the polyester polyol in an equivalent ratio of 1: 8. A coating liquid A was obtained by adding a nonionic surfactant as an agent at a solid content weight ratio of 1 to the polyurethane resin component 50.

<Preparation of Coating Solution for Composite Thin-Film Layer 10> 2) High-purity montmorillonite was used as an inorganic layered compound.
Polyvinyl alcohol (degree of polymerization 17) as a water-soluble polymer
00) was diluted with water so as to be 1: 1 in terms of weight to obtain a coating solution B.

<Comparative Example 1> In Example 1, the intermediate layer 2 was used.
Was obtained in the same manner as above except that the metal thin film layer was not provided on one side.

<Comparative Example 2> In Example 1, the intermediate layer 2
A laminate was obtained in the same manner as above except that the face material layer 4 was a single layer of polypropylene having a thickness of 40 μm.

<Evaluation> For each of the laminates of the examples and comparative examples, (1) oxygen permeability (ml / m ² · day · MP
a), (2) Water vapor transmission rate (gr / m ² · day)
(3) Transparency, (4) waist strength, and (5) impact strength were evaluated. Table 1 shows the results.

(1) Oxygen permeability Oxygen permeability measuring device (OXT manufactured by Modern Control Co., Ltd.)
30 ° C.-70% RH using RAN-10 / 50A)
Measured under medium conditions.

(2) Water vapor transmission rate Water vapor transmission rate measuring apparatus (PE manufactured by Modern Control Co., Ltd.)
RMATRAN-W / W31) at 40 ° C-90.
Measured under conditions in% RH.

(3) Light-Shielding Property The transmittance (%) at a wavelength of 350 nm was measured using a spectrophotometer (UV-3100, manufactured by Shimadzu Corporation).

(4) Waist Strength Loop stiffness was measured as waist strength (mN). Loop stiffness is 25mm wide and 12cm long
Make a strip-shaped sample of, crushing distance 20mm,
The loop is crushed at a compression speed of 3.5 mm / sec, and the repulsive force of the loop is measured. The larger the value, the higher the waist strength.

(5) Impact Strength The impact strength (N) is 13 mm in diameter at -10 ° C.
A weight having a weight of 6.5 mm and a height of 6.5 kg was dropped from a height of 1.3 m, and the maximum load was measured. The higher the value, the higher the impact strength.

[0104]

[Table 1]

Compared with the examples, the comparative examples do not satisfy all of the properties such as gas barrier properties (oxygen permeability, water vapor permeability), light-shielding properties, rigidity and impact resistance required as packaging materials. It can be said that the example satisfies all of those characteristics.

[0106]

As described above, according to the present invention, a packaging material having excellent waist strength and impact resistance can be provided by forming a sandwich structure in a resin layer. Further, since a vapor deposition thin film layer made of metal is provided on at least one surface of the intermediate layer having a sandwich structure in order to impart gas barrier properties and light shielding properties, a highly practical packaging material can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a gas barrier laminate having a light-shielding property with excellent waist strength and impact resistance according to the present invention.

FIG. 2 is a cross-sectional view showing an example of a gas barrier film forming a face material layer.

FIG. 3 is a sectional view showing another example of a gas barrier film forming a face material layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Surface material layer 2 ... Intermediate layer 3 ... Metal deposition thin film layer 4 ... Surface material layer 5 ... Base material 6 ... Inorganic oxide thin film layer 7 ... Gas barrier coating film layer 9 ... Undercoat layer 10 ... Composite thin film layer

 ────────────────────────────────────────────────── ─── Continuing on the front page F term (reference) 4F100 AA17E AA18E AA19E AA20E AB01B AB01E AB10B AC03E AK01A AK01C AK01D AK01E AK21E AK52E AK63A AK63C JAK BAD BA13 BA26E20 GBA JD02D JD02E JK01 JK07A JK07B JK07C JK07D JK07E JK10 JN02 YY00A YY00C YY00D

Claims (15)

[Claims] 1. A laminate comprising three or more resin layers including an intermediate layer comprising a resin film on which metal is vapor-deposited on at least one side, wherein an intermediate layer in which three or more adjacent layers are single or laminated. Has a sandwich structure consisting of a layer and two face material layers sandwiching the intermediate layer, and the elastic modulus of the same or different resin used for the face material layer sandwiching the intermediate layer is used for the intermediate layer. A gas-barrier laminate having high waist strength and excellent impact resistance, characterized by having a modulus of elasticity higher than that of a resin. 2. A laminate comprising three or more resin layers including an intermediate layer comprising a resin film on which metal is vapor-deposited on at least one side, wherein three or more adjacent layers are single-layer or laminated intermediate layers. And two face material layers sandwiching the intermediate layer, and have a modulus of elasticity (E) of the same or different resin used for the face material layers sandwiching the intermediate layer.
1, E3) is at least 1.2 times greater in elastic modulus ratio (E1 / E2, E3 / E2) than the elastic modulus (E2) of the resin used for the intermediate layer. A gas barrier laminate with excellent light-shielding properties and excellent impact properties. 3. The waist strength and durability according to claim 1, wherein the thickness of the resin used for the intermediate layer is larger than the thickness of the resin layer of the face material layer. A gas barrier laminate with excellent light-shielding properties and excellent impact properties. 4. The gas-barrier laminate according to claim 1, wherein the vapor-deposited metal is aluminum. 5. The gas barrier film according to claim 1, wherein at least one of the face material layers is a gas barrier film.
The gas-barrier laminate having light-shielding properties excellent in waist strength and impact resistance described in any one of the above. 6. A gas barrier film having a thickness of 5 to 300 nm on at least one surface of a substrate made of a plastic material.
The gas-barrier laminate having a light-shielding property excellent in waist strength and impact resistance according to claim 5, wherein a vapor-deposited thin film layer made of an inorganic oxide is laminated. 7. The gas barrier property having a light-shielding property excellent in waist strength and impact resistance according to claim 6, wherein the inorganic oxide is aluminum oxide, silicon oxide, magnesium oxide alone or a mixture thereof. Laminate. 8. A structure in which a gas barrier coating layer is further laminated on a vapor-deposited thin film layer made of an inorganic oxide, wherein the gas barrier coating layer comprises a water-soluble polymer, (a) one or more metal alkoxides and The hydrolyzate or (b)
Applying a coating agent mainly containing an aqueous solution containing at least one of tin chloride or a water / alcohol mixed solution,
The gas-barrier laminate according to claim 6, wherein the gas-barrier laminate has excellent waist strength and impact resistance, and is a layer formed by heating and drying. 9. A gas-barrier laminate having a light-shielding property excellent in waist strength and impact resistance according to claim 8, wherein the metal alkoxide is tetraethoxysilane or triisopropoxyaluminum, or a mixture thereof. body. 10. The gas-barrier laminate according to claim 8, wherein the water-soluble polymer is polyvinyl alcohol. 11. A gas barrier film comprising a base material made of a plastic material and a composite thin film layer mainly composed of an inorganic layered mineral and a water-soluble polymer laminated on at least one surface of the base material. 5. A gas-barrier laminate having light-shielding properties excellent in waist strength and impact resistance according to 5. 12. The gas-barrier laminate having a light-shielding property excellent in waist strength and impact resistance according to claim 11, wherein the composite thin film layer further contains a metal alkoxide or a hydrolyzate thereof. body. 13. The gas-barrier laminate according to claim 11, wherein the water-soluble polymer is a polyvinyl alcohol-based resin or a derivative thereof. 14. The gas-barrier laminate according to claim 11, wherein the inorganic layered mineral is montmorillonite and has a light-shielding property excellent in waist strength and impact resistance. 15. The interlayer distance of the inorganic layered mineral in the composite thin film layer is 1.2 times or more the interlayer distance of the inorganic layered mineral alone before the formation of the composite thin film layer with the water-soluble polymer. The gas-barrier laminate according to claim 11, wherein the laminate has excellent waist strength and impact resistance and has a light-shielding property.