JP4548073B2 - Gas barrier transparent laminate - Google Patents

Description

  The present invention relates to a transparent laminate for packaging used for packaging foods, daily necessities and pharmaceuticals, etc., or a transparent laminate used for electronic equipment-related members, etc. The present invention relates to a gas barrier transparent laminate suitably used as an electronic device member or the like.

  Packaging materials used for packaging foods, daily necessities, pharmaceuticals, etc. contain oxygen, water vapor, etc. that permeate the contents in order to prevent the contents from being altered and maintain their functions and properties even during packaging. It is necessary to prevent the influence of the gas that changes the property, and it is required to have a gas barrier property to block these. As a general packaging material having gas barrier properties, a film of vinylidene chloride resin or a film coated with them has been often used, which has relatively high gas barrier properties among polymers, but these have high gas barrier properties. It cannot be used for the required packaging. Therefore, when there is such a request, a packaging material using a metal foil made of a metal such as aluminum as a gas barrier layer has to be used.

  However, packaging materials using metal foils made of metal such as aluminum have almost no influence of temperature and humidity and have high gas barrier properties, but the contents cannot be confirmed through the packaging materials. However, there are a number of drawbacks, such as the fact that it must be treated as an incombustible material upon disposal after use, and that a metal detector cannot be used at the time of inspection.

  Therefore, as a packaging material that overcomes these drawbacks, a vapor-deposited thin film made of an inorganic oxide such as silicon oxide, aluminum oxide, or magnesium oxide is formed on a plastic film by using a thin film forming means such as vacuum vapor deposition or sputtering. The vapor deposition film formed is marketed (for example, refer patent document 1, 2). These vapor-deposited films are known to have transparency and gas barrier properties against oxygen, water vapor, and the like, and are suitable as packaging materials having both transparency and gas barrier properties that cannot be obtained with metal foil or the like. .

  However, even if a vapor-deposited film comprising an inorganic oxide and having both transparency and gas barrier properties is a film suitable for packaging materials, it should be used alone as a packaging body such as a packaging container. As a post-processing after depositing a deposited thin film, characters, designs, etc. are printed on the deposited film surface, bonded to other films, etc., and the shape of a package such as a container The packaging body is completed through various processes such as molding. Therefore, as a constituent material of the package, it is required to maintain the initial gas barrier property even if various processes are applied thereto.

  By the way, when the gas barrier properties such as oxygen transmission rate and water vapor transmission rate were measured after the bag was bonded to the sealant film using the vapor deposition film having the above-described configuration, the gas barrier property equivalent to the polymer gas barrier film was observed. However, it was found that the gas barrier property was deteriorated by post-processing, and the gas barrier property equivalent to the metal foil originally possessed by the deposited film could not be secured.

As a technique for solving such a problem, a vapor deposition layer made of an inorganic compound is a first layer, a water-soluble polymer, one or more kinds of metal alkoxide or metal alkoxide hydrolyzate, or
There has been proposed a gas barrier packaging material in which an aqueous solution containing at least one of tin chloride, or a coating agent mainly composed of water or an alcohol mixed solution is applied, and a gas barrier coating formed by heating and drying is sequentially laminated as a second layer. (For example, refer to Patent Document 3). This gas barrier packaging material exhibits high gas barrier properties, water resistance and moisture resistance, and even when deformed to some extent, these characteristics do not deteriorate. However, since the gas barrier coating of the gas barrier packaging material comprises a vapor-deposited layer made of an inorganic compound, depending on the post-processing conditions when used as a packaging container or packaging material, the characteristics that the transparent laminate had initially, especially Gas barrier properties often deteriorate due to stress during processing.

The present invention is intended to solve the above-described problems of the prior art, and is excellent in transparency, gas barrier properties, and surface smoothness, and even when stress is applied, the initial gas barrier properties are unlikely to deteriorate. It is an object of the present invention to provide a gas barrier transparent laminate suitably used as a material, a substrate for an electronic device member or the like.
U.S. Pat. No. 3,442,686 Japanese Patent Publication No.63-28017 Japanese Patent Application Laid-Open No. 07-164591

The present invention has been made to achieve such an object, and the invention according to claim 1 includes a gas barrier vapor-deposited thin film layer made of an inorganic oxide on a substrate made of a transparent plastic material , and 50 characterized in that the gas barrier coating layer comprising a mixture of wt% to 70 wt% propoxylated neopentyl glycol diacrylate and propylene glycol monophenyl ether acrylate and ethoxylated trimethylol propane triacrylate are sequentially stacked It is a gas barrier transparent laminate.

  The invention according to claim 2 is the transparent laminate according to claim 1, wherein the thickness of the gas barrier vapor-deposited thin film layer made of an inorganic oxide is 5 nm or more and 300 nm or less, and the thickness of the gas barrier film layer is It is 0.02 μm or more and 20 μm or less.

Furthermore, the invention described in claim 3 is the transparent laminate according to claim 1 or 2 , wherein a printed layer, an outer substrate layer, an intermediate layer, or a heat seal layer is laminated on the gas barrier coating layer.
It is characterized by being.

The present invention is a laminate in which a gas barrier vapor-deposited thin film layer made of an inorganic oxide and a gas barrier film layer obtained by curing a flash vapor deposited film of a polymerizable acrylic monomer or a mixture of a monomer and an oligomer are sequentially laminated. Since the part is laminated at least on a base material made of a transparent plastic material, both transparency, surface smoothness and gas barrier properties are excellent, and stress is applied during post-processing to make a package or the like. However, the initial excellent gas barrier properties are not easily deteriorated, and have high gas barrier properties and transparency, and the packaging material is required to have the original gas barrier properties not easily deteriorated even when various stresses are applied. Can be widely used as electronic equipment members and display substrates that require excellent gas barrier properties and surface smoothness. It made.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of a gas barrier transparent laminate of the present invention. A gas barrier transparent laminate 1 shown in FIG. 1 is a flash of a vapor-deposited thin film layer 3 made of an inorganic oxide and a polymerizable acrylic monomer or a mixture of monomers and oligomers on a substrate 2 made of a transparent plastic material. A laminated portion 5 is laminated in which a gas barrier coating layer 4 formed by curing a vapor deposition coating is sequentially laminated.

  The above-mentioned base material 2 is made of a transparent plastic material, for example, a polyester film made of polyethylene terephthalate (PET) or polyethylene naphthalate, a polyolefin film made of polyethylene, polypropylene, or the like, a polystyrene film, a polyamide film, a polyvinyl chloride film, a polycarbonate. A biodegradable plastic film such as a film, a polyacrylonitrile film, a polyimide film, or a polylactic acid film is used. These films may be either stretched or unstretched, but those having mechanical strength and dimensional stability are preferred. Among these, a polyethylene terephthalate film arbitrarily stretched in a biaxial direction from the viewpoint of heat resistance and dimensional stability is preferably used.

  The surface of these base materials 2 may be provided with a functional layer composed of various known additives and stabilizers, for example, an antistatic agent, an ultraviolet ray preventing agent, a plasticizer, a lubricant, and the like. In order to improve the adhesion with the vapor deposition thin film layer 3 made of an inorganic oxide film formed thereon, a corona treatment, a low temperature plasma treatment, an ion bombardment treatment or the like is performed as a pretreatment, and further a chemical treatment, A solvent treatment or the like may be performed.

  The thickness of the base material 2 is not particularly limited, but is suitable as a packaging material, and may be laminated with other layers other than the gas barrier vapor deposition thin film layer and the gas barrier film layer described above, Considering the workability and the like when forming the vapor-deposited thin film layer 3 and the gas barrier coating layer 4 made of an inorganic oxide, which will be described later, it is practically in the range of 3 μm or more and 200 μm or less, and 6 μm or more and 30 μm or less depending on applications Is preferred. In consideration of mass productivity, it is desirable to use a long film so that each layer can be formed continuously.

  On the other hand, the vapor-deposited thin film layer 3 made of an inorganic oxide is composed of a vapor-deposited thin film made of an inorganic oxide such as aluminum oxide, silicon oxide, tin oxide, magnesium oxide, or a mixture thereof, and has transparency and oxygen. Any material having gas barrier properties against water vapor or the like may be used. Among these, a vapor-deposited thin film layer made of any one of aluminum oxide, silicon oxide, and magnesium oxide is particularly preferable because of its excellent oxygen permeability and water vapor permeability. However, the vapor-deposited thin film layer 3 made of this inorganic oxide is not limited to those made of the above-mentioned inorganic oxide, and may be made of an inorganic oxide capable of forming a vapor-deposited thin film layer that meets the above conditions. Good.

The optimum thickness of the vapor-deposited thin film layer 3 made of an inorganic oxide varies depending on the type and configuration of the inorganic oxide used, but is generally within the range of 5 nm to 300 nm, and the value is appropriately selected. The However, if the layer thickness is less than 5 nm, it may be difficult to obtain a uniform thin film layer or the layer thickness may not be sufficient, and the function as a gas barrier material may not be sufficiently achieved. If the layer thickness exceeds 300 nm, it is difficult to maintain flexibility in the thin film layer, and if an external stress such as bending or pulling is applied after the film formation, the thin film layer may be cracked. The range of 100 nm or less is preferable.

  The deposited thin film layer 3 made of an inorganic oxide can be formed by a normal vacuum deposition method, but other thin film forming methods such as sputtering, ion plating, and plasma vapor deposition (CVD) are used. You can also. However, considering productivity, the vacuum deposition method is the best at present. As the heating means of the vacuum deposition apparatus by the 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 deposited thin film layer and the substrate and the denseness of the thin film layer, a plasma assist method or an ion beam assist method can be used. Furthermore, in order to increase the transparency of the deposited thin film layer, it is possible to carry out reactive deposition in which oxygen gas or the like is blown during deposition.

  On the other hand, the gas barrier coating layer 4 is a coating layer formed by curing a flash vapor deposition coating of a polymerizable acrylic monomer or a mixture of a monomer and an oligomer, and has high gas barrier properties in cooperation with the lower vapor deposition thin film layer 3. In addition, the gas barrier property can withstand the stress even when stress is applied from the outside, and the initial gas barrier property can be secured, and surface smoothness, weather resistance, contamination resistance, etc. It is provided for the purpose of imparting surface protection.

  Here, the flash vapor deposition film is a film formed by a so-called flash vapor deposition method. More specifically, a resin component composed of a polymerizable acrylic monomer or a mixture of a monomer and an oligomer is evaporated at high temperature under vacuum. A gas barrier property obtained by heating and vaporizing immediately above the source and then depositing and coating on the inorganic oxide layer 3, which is obtained by curing the coating by electron beam or ultraviolet irradiation. It is the coating layer 4.

  When the coating is cured by ultraviolet irradiation, an acrylic resin-based coating agent mixed with a photopolymerization initiator is used as the second component. Specific examples of the photopolymerization initiator include benzoin ethers, benzophenones, xanthones, acetophenone derivatives, and the like. These are 0.01% by weight based on an acrylic monomer or a mixture of monomers and oligomers. It is used by mixing at a ratio of not less than 10% by weight, preferably not less than 0.1% by weight and not more than 2% by weight.

  Since the gas barrier coating layer 4 can be formed under vacuum as in the case of the gas barrier vapor deposition thin film layer 3 described above, these layers can be continuously laminated, enabling efficient production. Production costs can also be reduced.

  In order for the gas barrier transparent laminate 1 of the present invention to exhibit higher gas barrier properties, the gas barrier coating layer 4 preferably has a thickness of 0.02 μm to 20 μm. This is because if the layer thickness is less than 0.02 μm, it is difficult to form a uniform coating layer, and if it exceeds 20 μm, the curing rate decreases and it is difficult to sufficiently cure.

  Moreover, when hardening a flash vapor deposition film with an electron beam, the balance of the film thickness of a flash vapor deposition film, electron beam energy conditions, a processing speed, and static elimination becomes important. Excessive energy supply causes electrification, and care must be taken because gas barrier properties may be impaired by the resulting discharge.

Here, as the polymerizable acrylic monomer and oligomer, for example, polyester acrylate, polyether acrylate, acrylic acrylate, urethane acrylate, epoxy acrylate, silicone acrylate, polyacetal acrylate,
Examples include monomers or oligomers having a polymerizable double bond such as polybutadiene acrylate and melamine acrylate. As the monomer or oligomer, monofunctional, bifunctional, trifunctional, or higher polyfunctional monomers can be appropriately selected and used depending on the number of reactive functional groups possessed.

  These monomers or oligomers can be used as a mixture of two or more types, but it is desirable to use a mixture of three types of monoacrylate, diacrylate and triacrylate. In this case, it is preferable to use a monoacrylate having a functional group such as a hydroxyl group, a carboxyl group, an amino group, or an epoxy group. The reason why such a mixture is used is to further improve the adhesion with the deposited thin film layer 3 made of an inorganic oxide. Diacrylate is used as a basic component of the gas barrier coating layer 4, and triacrylate is used to improve the degree of crosslinking in the gas barrier coating layer 4. In addition, in order for the functional group-added monoacrylate and triacrylate of the above-mentioned three types of mixtures to each express the above-described function, it is preferable to add 0.05% by weight or more, so the mixing ratio of diacrylate is 50% by weight The content is preferably 99.9% by weight or less.

  In addition, as described above, when a flash vapor deposition film is formed by using the flash vapor deposition method, a small amount of an acrylic monomer or a mixture of monomers and oligomers as a raw material for evaporation is placed in a high temperature evaporation source under vacuum. It is necessary to drop it at a time and evaporate it immediately above the evaporation source. If the viscosity of the acrylic monomer or monomer / oligomer mixture is too high, it will be difficult to drop it into the evaporation source at a constant rate. Therefore, it is desirable that the viscosity is 200 [mPa · s / 25 ° C.] or less, more preferably 100 [mPa · s / 25 ° C.] or less.

  Furthermore, since the gas barrier transparent laminate of the present invention is also used in the packaging field of foods, daily necessities, pharmaceuticals, etc., the mixture of acrylic monomers and oligomers described above has a skin irritation (PII) of 2.0 or less. It is desirable that

  The basic configuration of the gas barrier transparent laminate of the present invention has been described above, but the present invention is not limited to these, and a laminated portion composed of the gas barrier deposited thin film layer and the gas barrier coating layer described above. May be provided on the other surface of the substrate, or the laminated portion may be a multilayer.

  Furthermore, another layer may be laminated on the gas barrier coating layer 4. Specifically, the other layers are a printing layer, an outer base material layer, an intermediate layer, a heat seal layer, and the like. The printed layer is laminated for practical use as a packaging bag or the like. For example, various pigments are added to conventionally used ink binder resins such as urethane, acrylic, nitrocellulose, rubber and vinyl chloride. , Characters, designs, and the like composed of inks to which additives such as extender pigments, plasticizers, drying agents, stabilizers, and the like are added.

  As the type of ink constituting the printing layer, various types of inks such as a surface printing type and a back printing type can be used. As a method for forming the printing layer, for example, a known printing method such as an offset printing method, a gravure printing method, a silk screen printing method, or a known coating method such as a roll coating, a knife edge coating, or a gravure coating can be used. . The thickness may be 0.1 μm or more and 2.0 μm or less.

The outer base material layer is a layer provided so that the deposited thin film layer and the coating layer are sandwiched between the base material and the base material, and is generally polyethylene terephthalate (PET) in terms of mechanical strength. In addition, a polyester film made of polyethylene naphthalate or the like, a polyolefin film made of polyethylene or polypropylene, a polyamide film, a polycarbonate film, a polyacrylonitrile film, a polyimide film, or the like is used. Among these, a polyethylene terephthalate film, a polypropylene film and the like arbitrarily stretched in the biaxial direction are particularly preferable.

  For example, the outer base material layer may be provided by using a known method such as a dry lamination method, a non-solvent lamination method, or an extrusion lamination method in which the film is bonded using an adhesive such as a two-component curable urethane resin. The thickness is determined according to the material and required quality, but is generally in the range of 5 μm to 50 μm.

  The intermediate layer is provided to increase the bag breaking strength and puncture strength when the gas barrier transparent laminate of the present invention is used to form a bag-like package, and generally has mechanical strength and thermal stability. To biaxially stretched nylon film, biaxially stretched polyethylene terephthalate film, biaxially stretched polypropylene film and the like.

  The thickness of the intermediate layer is determined according to the material and required quality, but is generally in the range of 5 μm to 50 μm. As the formation method, a known method such as a dry laminating method, a non-solvent laminating method, an extrusion laminating method, or the like, which is bonded using an adhesive such as a two-component curable urethane resin can be applied.

  The heat seal layer is provided so as to act as an adhesive layer when a bag-shaped package or the like is manufactured. 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 It is a layer made of a resin such as a cross-linked product. The thickness is determined according to the purpose, but is generally in the range of 15 μm 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 composed of the above resin is bonded using an adhesive such as a two-component curable urethane resin. Can be stacked. Hereinafter, the high gas barrier transparent laminate of the present invention will be further described with specific examples.

A biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was used as the substrate. First, metal aluminum was evaporated using an electron beam heating vacuum deposition apparatus, oxygen gas was introduced therein, and a gas barrier vapor deposition thin film layer made of aluminum oxide was formed with a thickness of 15 nm on one side of the substrate. . Next, propylene glycol monophenyl ether acrylate as the monoacrylate, propoxylated neopentyl glycol diacrylate as the diacrylate, and ethoxylated trimethylolpropane triacrylate as the triacrylate, respectively, and the proportions shown in Table 1 are shown in Table 1. Using the coating agent (viscosity of 38 mPa · s) blended in the above, a flash vapor deposition film having a thickness of 0.2 μm is provided on the gas barrier vapor deposition thin film layer formed in the above step using a flash vapor deposition method, and then flashed. The vapor-deposited coating was irradiated with an electron beam to form a gas barrier coating layer, and the gas barrier transparent laminate of the present invention was obtained.

  As shown in Table 1, the coating agent is diacrylate propoxylated neopentyl glycol diacrylate alone, and the viscosity is 15 mPa · s, under the same conditions as in Example 1 and according to Example 2 for comparison. A transparent laminate was obtained.

Propylene glycol monophenyl ether acrylate as monoacrylate, propoxylated neopentyl glycol diacrylate as diacrylate, and ethoxylated trimethylolpropane triacrylate as triacrylate were used, and the respective mixing ratios were compounded under the conditions shown in Table 1. The transparent laminated body which concerns on Example 3 for a comparison was obtained on the conditions similar to Example 1 except having used the coating agent (viscosity is 122 mPa * s).
<Measurement of oxygen permeability 1>
For each of the transparent laminates of Examples 1 to 3, the oxygen transmission rate (cc / m ² · day · atm), which is a standard for evaluating the gas barrier properties, was measured with OXTRAN manufactured by MOCON. The results are shown in Table 1.
<Secondary processing: Printing processing>
On the coating layer of the transparent laminates of Examples 1 to 3, a printing layer was provided by a gravure printing method using a urethane ink for back printing, and a post-processed sample was obtained.
<Measurement 2 and evaluation of oxygen permeability>
The oxygen permeability (cm ² / m ² · day · atm) of each post-processed sample subjected to the secondary processing was also measured with OXTRAN manufactured by MOCON.

  And comprehensive evaluation was performed based on these measurement results. The evaluation criteria are ○ (good) when the transparent laminate itself and the oxygen barrier property after printing are both good (good), and other than ○ when the barrier property after printing was not significantly deteriorated, and the barrier after printing Those having greatly deteriorated properties were evaluated as x (defect). The results are as shown in Table 1.

It is sectional drawing which shows the structure of the gas-barrier transparent laminated body of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas barrier property transparent laminated body 2 ... Base material 3 ... Deposition thin film layer 4 which consists of inorganic oxides ... Gas barrier property coating layer 5 ... Laminate part

Claims (3)

Gas barrier vapor-deposited thin film layer made of inorganic oxide on base material made of transparent plastic material , propoxylated neopentyl glycol diacrylate, propylene glycol monophenyl ether acrylate and ethoxylated trimethylol of 50 wt% to 70 wt% gas-barrier transparent laminate, characterized in that the gas barrier coating layer comprising a mixture of propane triacrylate are sequentially stacked. 2. The gas barrier according to claim 1, wherein a thickness of the gas barrier vapor-deposited thin film layer made of the inorganic oxide is 5 nm or more and 300 nm or less, and a thickness of the gas barrier film layer is 0.02 μm or more and 20 μm or less. Transparent laminate. The gas barrier transparent laminate according to claim 1, wherein a printed layer, an outer substrate layer, an intermediate layer, or a heat seal layer is laminated on the gas barrier coating layer.

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