JP2003039589A - Laminated deposition film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a layer of an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer on a vapor deposition layer surface of a plastic film having a ceramic vapor deposition layer on a substrate via a gas barrier protective layer. By providing a laminated vapor-deposited film, it is possible to prevent cracks due to bending and a decrease in barrier properties, which are disadvantages of the conventional ceramic vapor-deposited film. SOLUTION: An aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer is coated on a vapor-deposited layer surface of a plastic film having a vapor-deposited layer of a ceramic such as silica or alumina on a substrate via a gas barrier protective layer. . As the gas barrier protective layer, a layer containing polyvinyl alcohol is preferable.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laminated vapor-deposited film, and more particularly to a laminated vapor-deposited film having a protective layer formed on the vapor-deposited layer surface of a plastic film having a ceramic vapor-deposited layer on a substrate. .

[0002]

2. Description of the Related Art In packaging films for various products such as foods, pharmaceuticals, electronic materials or products, a metal such as aluminum is laminated on the surface of the film for the purpose of maintaining the quality of the content, for the purpose of gas barrier, especially oxygen barrier. What you have done is widely known. On the other hand, in recent years, metal vapor deposition films such as aluminum have become a hindrance to the use of metal detectors for environmental measures or removal of foreign substances,
The tendency of dealumination is gradually increasing.

As a substitute material for the metal vapor deposition film of aluminum or the like, a film obtained by vapor deposition of a ceramic such as silica or alumina is drawing attention. For example, JP-A-2-122924 and JP-A-3-71
No. 832 proposes a vapor deposition film using silica, and JP-A No. 10-140331 proposes a vapor deposition film using alumina. In addition, JP-A-3-2393
JP-A No. 4-191051 proposes a vapor-deposited film using alumina, and JP-A-3-191051 proposes a vapor deposition film using an oxide of silicon and aluminum in combination.

However, the barrier property is often insufficient in practical use only with a film obtained by vapor deposition of ceramics,
Many methods for improving the barrier property have been proposed and put to practical use, also for protecting the ceramic vapor deposition layer. Specifically, an aqueous polymer having a gas barrier property is laminated as a gas barrier protective layer. JP-A-11-310680 and JP-A-2
In JP-A-000-62108, it is described that by coating polyvinyl alcohol on the ceramic vapor-deposited surface, it is possible to further improve the barrier property and protect the ceramic vapor-deposited surface, so that cracking due to bending is less likely to occur.

In addition, in Japanese Patent Laid-Open No. 11-165369, a ceramic vapor deposition surface is coated with an organic coating layer composed of polyvinyl alcohol and an inorganic layered compound, and Japanese Patent Laid-Open Nos. 2001-64423 and 2001-2001.
Japanese Patent No. 145973 discloses coating a ceramic vapor deposition surface with a gas barrier protective layer composed of polyvinyl alcohol and a metal alkoxide via a primer.

The conventional packaging films including these prior arts are excellent in gas barrier property and also excellent in commercial value, but there is a problem that the vapor-deposited surface is weak in bending and cracks occur to deteriorate the barrier property. However, it is hard to say that even if a gas barrier protective layer is laminated, it is still sufficient. In addition, the gas barrier protective layer has a problem of poor adhesion to other base materials, and when an adhesive or an adhesive resin layer is laminated on the gas barrier protective layer, delamination occurs from the interface with the gas barrier protective layer, There is a risk of causing major trouble.

Further, the conventional method has various problems as described below from the viewpoint of laminating with another substrate through an adhesive or an adhesive resin layer. At present, as a laminating method, roughly, there are a method of performing extrusion coating, a method of laminating films, and a method of coating a coating agent such as emulsion.

When extrusion coating is performed, it is necessary to use an anchor coating agent because of the poor adhesion of the gas barrier protective layer, and it is necessary to select an anchor coating agent from many types. Very few anchor coat agents have good adhesiveness. In addition, there is a limit to the coating thickness of the adhesive resin layer, and there is a problem that the greater the thickness, the greater the stress when being bent. In the method of laminating films, it is more difficult to select an adhesive than in the above method, and the total thickness of the laminated film is further increased.

On the other hand, when coating an emulsion or the like,
It is difficult to select an emulsion from the viewpoint of adhesiveness with the gas barrier protective layer, and an emulsion with good adhesiveness is sticky and generally causes severe blocking. Adhesion with a polyolefin-based material generally used as a packaging material is difficult. Bad things, and further, lack of heat sealability.

As a result of earnest studies, the inventors of the present invention have shown that the gas barrier protective layer is coated with an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer to obtain adhesiveness, heat sealability and blocking resistance. , Forming a coating layer having excellent solvent resistance, and finding that a laminated vapor-deposited film with improved defects such as bending and cracking can be obtained,
The present invention has been completed.

[0011]

Therefore, an object of the present invention is to form a resin coating layer having excellent adhesiveness, heat sealability, blocking resistance, and solvent resistance, and to improve fragility against bending. Therefore, it is to provide a laminated vapor-deposited film having no defects such as cracks. Also,
Another object of the present invention is to provide a laminated vapor-deposited film having not only a protective function for the vapor-deposited layer but also easy printability and heat sealability to the vapor-deposited film. Still another object of the present invention is to provide a laminated vapor-deposited film in which a coating film having excellent adhesiveness to a polyolefin-based material is adopted and thereby easy adhesion is provided.

[0012]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and comprises an ethylene / unsaturated carboxylic acid copolymer having a gas barrier protective layer on a vapor-deposited film. An important feature is that the aqueous dispersion is coated.

That is, according to the present invention, an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer is provided on the vapor-deposited layer surface of a plastic film having a ceramic vapor-deposited layer on a substrate via a gas barrier protective layer. A laminated vapor-deposited film characterized by being coated is provided.

Further, according to the present invention, there is provided the above laminated vapor-deposited film, wherein the gas barrier protective layer is a layer containing polyvinyl alcohol.

Further, according to the present invention, there is provided the above laminated vapor-deposited film, wherein the ceramic is silica or alumina.

Further, according to the present invention, there is provided the above laminated vapor-deposited film, wherein the dispersion medium of the aqueous dispersion is ammonia or an alkali metal hydroxide.

According to the present invention, the aqueous dispersion has an unsaturated carboxylic acid content of 10 to 35% by weight and a melt flow rate (190 ° C., 2160 g load) of 50.
The laminated vapor-deposited film comprising the ethylene / acrylic acid copolymer and ammonia having a weight of 2000 to 2000 g / 10 minutes is provided.

Further, according to the present invention, there is provided a laminated vapor deposition film in which the aqueous dispersion contains a divalent or trivalent metal in addition to the alkali metal.

Further, according to the present invention, there is provided the above laminated vapor-deposited film, wherein the aqueous dispersion contains zinc.

Further, according to the present invention, there is provided the above laminated vapor-deposited film, wherein the aqueous dispersion contains a silane coupling agent in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the aqueous dispersion. .

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The feature of the present invention is that an ethylene / unsaturated carboxylic acid copolymer is formed on a vapor-deposited layer surface of a plastic film having a ceramic vapor-deposited layer such as silica or alumina on a substrate through a gas barrier protective layer. This is because it is coated with the combined aqueous dispersion, which makes it possible to obtain a laminated vapor-deposited film which is excellent in adhesiveness, heat sealability, blocking resistance, solvent resistance, and is significantly improved in bending, cracking and the like.

<Substrate Film> The substrate film constituting the laminated vapor deposition film of the present invention is not particularly limited as long as it is a plastic film capable of vapor depositing ceramics, but polyethylene terephthalate, polyamide,
Examples of the film include polyamide imide, polyethylene, polypropylene, cellulose acetate, polycarbonate, polyvinyl chloride, and fluororesin film. Among them, polyethylene terephthalate, nylon, and polypropylene are preferable base film.

The thickness of the base material film is not particularly limited, and a thickness of about 3 to 200 μm is usually used.
Further, the substrate film is preferably uniaxially stretched or biaxially stretched, and when using the one whose surface is surface-treated by corona discharge treatment or low-temperature plasma treatment, the vapor deposition of ceramic is more effective. Done.

<Ceramic Vapor Deposition Layer> As the ceramic, silica, alumina, zirconium oxide, titanium oxide, magnesium oxide and the like are used. Among them, silica and alumina are used as the vapor deposition layer in terms of gas barrier property and substrate adhesion. It is preferably used. The metal species used may be two or more in combination, and may be laminated with the same or different ceramics. The vapor deposition of ceramics on the substrate film is performed by, for example, a physical vapor deposition method (PVD method) such as a vacuum vapor deposition method, a sputtering method, an ion spraying method, a plasma chemical vapor deposition method, a thermochemical vapor deposition method, or a photochemical method. It is performed by a method known per se such as a chemical vapor deposition method (CVD method) such as a vapor phase growth method.

The protective layer for gas barrier property in the present invention can be used without particular limitation as long as it has a property of blocking gas such as oxygen. For example, polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, Carboxymethyl cellulose,
A water-soluble polymer such as sodium alginate and an aqueous solution of one or more metal alkoxides or their hydrolysates and / or tin chloride, or a coating agent containing a water / alcohol mixed solution as a main component, and above all, the above water-soluble polymers A layer using polyvinyl alcohol, a layer formed of a composite coating film containing a mixture containing polyvinyl alcohol and an inorganic layered compound such as montmorillonite, and boric acid as a main component are preferably used. As can be seen from the above examples, the effect of the polyvinyl alcohol contained in the component of the gas barrier protective layer of the present invention becomes more remarkable. These gas-barrier protective layers can exhibit excellent gas-barrier properties even under high humidity conditions, so that the laminated vapor-deposited film obtained can be widely used for suitability.

<Coating Layer> In the present invention, the aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer is coated on the vapor deposition surface of the substrate film on which the above ceramic is vapor deposited through the gas barrier protective layer. . As the ethylene / unsaturated carboxylic acid copolymer, ethylene and acrylic acid, methacrylic acid, ethacrylic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monoethyl maleate, maleic anhydride, itaconic anhydride, etc. It is a copolymer with an unsaturated carboxylic acid, and among them, acrylic acid or methacrylic acid is preferable. The ethylene-unsaturated carboxylic acid copolymer may contain any other monomer.

In the ethylene / unsaturated carboxylic acid copolymer, the ethylene component is 65 to 90% by weight, preferably 70 to 85% by weight, and the unsaturated carboxylic acid component is 10 to 35% by weight, preferably 15 to 30%. % By weight. The melt flow rate (MFR) of the ethylene / unsaturated carboxylic acid copolymer at 190 ° C. under a load of 2160 g is 30 to 2000 g / 10 min, preferably 60 to 1500 g / 10 min.

Monomers which may optionally be contained in the ethylene / unsaturated carboxylic acid copolymer include vinyl acetate, vinyl esters such as vinyl propionate, methyl acrylate, ethyl acrylate, acrylic acid. Isopropyl, n-butyl acrylate, isobutyl acrylate,
Unsaturated carboxylic acid esters such as isooctyl acrylate, methyl methacrylate, isobutyl methacrylate, dimethyl maleate, diethyl maleate, carbon monoxide,
Examples thereof include sulfur dioxide, and these monomers are preferably contained in a proportion of about 0 to 50% by weight. Such an ethylene / unsaturated carboxylic acid copolymer can be obtained by a method known per se, for example, radical polymerization under high temperature and high pressure.

The aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer in the present invention is a dispersion comprising the above copolymer and a dispersion medium such as ammonia, sodium hydroxide, potassium hydroxide, etc., and the mixing ratio thereof. Is preferably a dispersion medium used in a proportion of 40 to 100% with respect to the number of moles of the carboxyl group of the ethylene / unsaturated carboxylic acid copolymer.

To produce an aqueous dispersion from an ethylene / unsaturated carboxylic acid copolymer and the above dispersion medium, for example, a container equipped with a stirrer is supplied with a predetermined amount of water and the above-mentioned two raw materials, and then 90 or It can be easily obtained by stirring at a temperature of about 150 ° C. for about 10 minutes to 2 hours. The aqueous dispersion of the present invention has excellent stability and does not significantly change in particle size and viscosity even when stored for a long period of time.

In the present invention, the divalent or trivalent metal can be dispersed by adding it as an oxide together with the dispersion medium when producing the aqueous dispersion. In addition to the oxide, it can be introduced in the form of a metal carbonate or a metal sulfate. The mixing ratio can be introduced at a rate of 0 to 60% with respect to the number of moles of the carboxyl group of the ethylene-unsaturated carboxylic acid copolymer. However, it cannot be introduced without the combined use of a dispersion medium of ammonia or an alkali metal.

The amount of the silane coupling agent added is 0.01 to 10 parts by weight based on 100 parts by weight of the aqueous dispersion.
It is preferably 0.1 to 5 parts by weight. The silane coupling agent preferably has a functional group capable of reacting with a carboxyl group, and epoxysilane and aminosilane are particularly preferable, but the silane coupling agent is not limited thereto.

In the aqueous dispersion of the present invention, if necessary,
Various additives known per se can be added. Such additives include polyhydric alcohols such as glycerin, ethylene glycol, polyethylene glycol and polypropylene glycol, water-soluble epoxy resins, lower alcohols such as methanol, ethanol, normal propanol and isopropanol, ethylene glycol monomethyl ether and propylene glycol monomethyl ether. Ethers such as ether, propylene glycol diethyl ether, diethylene glycol monoethyl ether, propylene glycol monoethyl ether, esters such as propylene glycol monoacetate, ethylene glycol monoacetate, antioxidants, weather stabilizers, UV absorbers, antistatic Examples thereof include agents, pigments, dyes, antibacterial agents, lubricants, inorganic fillers, antiblocking agents, and adhesives.

The aqueous dispersion of the present invention can be mixed with an aqueous dispersion of another polymer. Such polymer aqueous dispersions include polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, water-soluble acrylic resin, acrylamide resin, methacrylamide resin, acrylonitrile resin, styrene-acrylic acid. Copolymer, water-soluble polyurethane resin, water-soluble styrene-
Maleic acid copolymer, styrene-butadiene copolymer,
High impact polystyrene resin, butadiene resin, polyester resin, acrylonitrile-butadiene copolymer, polyethylene resin, polyethylene oxide resin, propylene-ethylene copolymer, maleic anhydride graft-propylene-ethylene copolymer, chlorinated polyethylene, chlorinated Aqueous dispersions of polypropylene, EPDM, phenolic resin, silicone resin, epoxy resin and the like can be used alone or in combination of two or more.

<Lamination of Gas Barrier Protective Layer on Ceramic Deposition Surface> In the present invention, the gas barrier protective layer is formed by coating a solution-like one by heating and drying, or by forming a film-like one in advance. May be formed by stacking. The thickness of the gas barrier protective layer is preferably 0.01 to 50 μm.

<Coating of Aqueous Dispersion on Vapor Deposition Film> Coating of an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer on a vapor deposition film having a gas barrier protective layer formed on the surface of the vapor deposition layer can be carried out by a known coating method. Is applied. For example, a coating method using a roll coater, a bar coater, a sprayer, an air knife coater or a brush may be performed, or the vapor deposition film may be dipped in the aqueous dispersion. After coating,
By heating and drying at a temperature of about 80 to 200 ° C. to evaporate water, a laminated vapor deposition film having a uniform coating layer can be obtained.

The thickness of the coating layer is not particularly limited, but is usually 0.1 to 20 μm, preferably 0.5 to 10 μm. The coating layer may be subjected to a crosslinking treatment by electron beam irradiation in order to improve water resistance and durability. In addition, preferable examples which can be used as an aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer of the present invention are also described in JP-A-2000-248141 filed by the present applicant.

The present invention has the problems that conventional ceramic vapor deposition films could not be suitably coated.
By using a specific coating agent called an aqueous dispersion of an ethylene-unsaturated carboxylic acid copolymer through a gas barrier protective layer on the vapor deposition surface, the laminated vapor deposition film originally has the ethylene-unsaturated carboxylic acid copolymer. ,Adhesiveness,
While imparting properties such as heat sealability, blocking resistance, and solvent resistance, it is possible to coat the resin under excellent adhesive strength, which further improves crack resistance due to bending, Moreover, it is possible to supply the laminated vapor-deposited film to a wide range of applications without lowering the barrier property, and its technical significance is great.

[0039]

According to the present invention, by coating an aqueous dispersion of an ethylene-unsaturated carboxylic acid copolymer through a gas barrier protective layer on a specific material called a ceramic vapor deposition film, the adhesiveness, It is possible to form a coating layer with excellent heat-sealing properties, blocking resistance, and solvent resistance, which effectively eliminates the problem of conventional ceramic vapor-deposited films that cracks occur when bent. It was

[0040]

EXAMPLES The preferred embodiments of the present invention will be described below based on examples, but the present invention is not limited thereto.

<Sample> (1) Vapor-deposited film / PVOH-coated alumina vapor-deposited PET film: thickness 12 μm (3) Aqueous dispersion / water dispersion A: Ethylene-methacrylic acid copolymer (EM
AA) -Na aqueous dispersion; solid content 25 wt%, ammonia dispersion, neutralization degree to MAA 50% -Water dispersion B: ethylene-acrylic acid copolymer (EA)
A) -Zn aqueous dispersion; solid content 21 wt%, ammonia dispersion (neutralization degree to acrylic acid 90%), ZnO addition (neutralization degree to acrylic acid 20%)-Aqueous dispersion C: EAA aqueous dispersion; Solid content 25 wt%,
Ammonia dispersion (75% neutralization degree to acrylic acid) -Water dispersion D: Ethylene-vinyl acetate emulsion (V
AE emulsion); solid content 50 wt%, "Sumikaflex S467" manufactured by Sumitomo Chemical Co., Ltd.-Water dispersion E: acrylic emulsion; solid content 33 wt
%, "NK Polymer" manufactured by Shin-Nakamura Chemical Co., Ltd. (4) Method for preparing EAA and EMAA aqueous dispersion Add resin, ion-exchanged water, ammonia or alkali metal, etc. to a 300 ml autoclave, and add 1 at 150 ° C.
After stirring for 800 hours at 800 rpm, it was cooled with tap water. The blending amount is as shown in Table 1.

[Table 1] (5) Silane coupling agent Epoxy silane: "KBM403" manufactured by Shin-Etsu Chemical Co., Ltd. (6) Coating method of aqueous dispersion Various water-based on the gas barrier protective layer of the ceramic vapor-deposited film with the gas barrier protective layer formed on the vapor deposition surface. Dispersion
It was coated using a bar coater so that the dry coating film had a thickness of 5 μm, and then dried at 150 ° C. for 2 minutes to obtain a laminated vapor deposition film.

<Experimental Method> Various physical properties of the laminated vapor-deposited film obtained above were measured and evaluated by the following methods. (1) Measurement of oxygen permeability The gel was flexed 20 times to measure oxygen permeability (MOCON method). (2) Measurement of heat-sealing strength Various vapor-deposited PET films were coated with an aqueous dispersion at a thickness of 5 μm and dried at 150 ° C. for 2 minutes (only VAE emulsion had a thickness of 20 μm). Seal the coated surfaces of the film coated with the aqueous dispersion with each other (160 ° C x
1s), the adhesive strength of 15 mm width was measured. (3) Blocking test Various vapor-deposited PET films coated with an aqueous dispersion at a thickness of 5 μm (VAE emulsion only 2
0 μm) coated surfaces were overlapped with each other, a load of 200 g / cm ² was applied, and when T-type peeling was performed, the one exhibiting adhesive force was defined as “present”. (4) Polyolefin adhesion test Various aqueous dispersions were coated with a thickness of 5 μm, and the coated surface and the ethylene-vinyl acetate copolymer (EVAVA)
14%, MFR7) laminated PET film (EVA
20 μm / PE 20 μm / PET 12 μm) was heat-sealed (160 ° C. × 1 s), and the adhesive strength of 15 mm width was measured. (5) Solvent resistance test Various vapor-deposited PET films coated with an aqueous dispersion at a thickness of 5 μm (VAE emulsion only 2
One drop of toluene was dropped on the coated surface (0 μm), and the coated surface after volatilization was visually observed.

Example 1 A film in which polyvinyl alcohol was coated as a barrier organic layer on the alumina vapor deposition surface of an alumina vapor deposition PET film was used.
This polyvinyl alcohol layer was coated with an aqueous dispersion A with a bar coater to a thickness of 5 μm and dried at 150 ° C. for 2 minutes to prepare a coated film. Then
The oxygen permeability, heat seal strength, polyolefin adhesiveness, and solvent resistance of the gelbo flex were measured 20 times. The results are shown in Table 2.

Example 2 A coating film was prepared in the same manner as in Example 1 except that the aqueous dispersion B was used as the aqueous dispersion. The physical properties of the obtained film were measured in the same manner as in Example 1, and the results are shown in Table 2.

Example 3 An aqueous dispersion obtained by adding 1 g of a silane coupling agent to 50 g of the aqueous dispersion B was used, except that
A coating film was prepared in the same manner as in Example 1,
Each physical property was measured in the same manner as above. The results are shown in Table 2.

<Example 4> A coating film was prepared in the same manner as in Example 1 except that an aqueous dispersion prepared by adding 1 g of a silane coupling agent to 50 g of the aqueous dispersion C was used, and each physical property was measured in the same manner as described above. . The results are shown in Table 2.

Comparative Example 1 Each physical property was measured in the same manner as above using the film as it was without using the coating liquid. The results are shown in Table 2.

<Comparative Example 2> A coating film was prepared in the same manner as in Example 1 except that the aqueous dispersion D was used as the coating liquid, and the respective physical properties were measured in the same manner as above.
The results are shown in Table 2.

Comparative Example 3 A coating film was prepared in the same manner as in Example 1 except that the aqueous dispersion E was used as the coating liquid, and the physical properties were measured in the same manner as above.
The results are shown in Table 2.

[0050]

[Table 2]

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F100 AA17A AA19A AA20A AD00A                       AK01B AK21C AK70D AR00C                       BA04 BA10B BA10D EH46D                       EH66A EJ86D GB15 JA06C                       JD02 JD02C

Claims (8)

[Claims] 1. An aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer is coated on the vapor deposition layer surface of a plastic film having a ceramic vapor deposition layer on a substrate through a gas barrier protective layer. Laminated vapor deposition film. 2. The laminated vapor deposition film according to claim 1, wherein the gas barrier protective layer is a layer containing polyvinyl alcohol. 3. The laminated vapor deposition film according to claim 1, wherein the ceramic is silica or alumina. 4. The laminated vapor deposition film according to claim 1, wherein the dispersion medium of the aqueous dispersion is ammonia or an alkali metal hydroxide. 5. An aqueous dispersion having an unsaturated carboxylic acid content of 10 to 35% by weight and a melt flow rate (19).
50 ℃ to 2000g / 10 at 0 ℃, 2160g load)
The laminated vapor deposition film according to any one of claims 1 to 3, which comprises an ethylene / acrylic acid copolymer, which is a component, and ammonia. 6. The laminated vapor deposition film according to claim 1, wherein the aqueous dispersion contains a divalent or trivalent metal in addition to the alkali metal. 7. The aqueous dispersion contains zinc.
4. The laminated vapor deposition film according to any one of items 1 to 3. 8. The aqueous dispersion contains a silane coupling agent in an amount of 0.01 to 1 with respect to 100 parts by weight of the aqueous dispersion.
The laminated vapor deposition film according to any one of claims 1 to 3, which contains 0 part by weight.