JP2001191442A - Laminated structure with excellent gas barrier properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate having a sufficient gas barrier property, a high adhesive strength with a sealant layer, and a performance that is not deteriorated even when printing is performed on a deposition surface. Provide a structure. SOLUTION: On a vapor-deposited surface of a vapor-deposited plastic film in which a thin film composed of a metal oxide is formed on at least one surface of a substrate film, a coating layer formed by coating a metal oxide sol is provided. A laminated structure having excellent gas barrier properties characterized by laminating a sealant layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laminated structure having excellent gas barrier properties.

[0002]

2. Description of the Related Art Conventionally, gas-barrier vapor-deposited plastic films having a plastic film as a base material and a thin film of a metal oxide such as silicon oxide, aluminum oxide or magnesium oxide formed on the surface thereof have been used for various gases such as water vapor and oxygen. It is widely used for packaging of articles that require shielding, and for preventing deterioration of foods, industrial supplies, pharmaceuticals, etc. (JP-B-53-12953, etc.). In addition, this gas barrier vapor-deposited plastic film has recently been used in new applications such as liquid crystal display elements, solar cells, electromagnetic wave shields, touch panels, EL substrates, and some of transparent conductive sheets used in color filters, etc., in addition to packaging applications. Has also attracted attention.

[0003] Various improvements have been studied for such gas-barrier vapor-deposited plastic films for the purpose of preventing a reduction in gas-barrier properties, and a coating layer made of various polyurethanes, various polyesters, or a mixture of polyurethane and polyester is deposited. There is known a method of providing the surface (Japanese Patent Laid-Open No. 2-50837). Further, a gas barrier laminated film in which a gas barrier resin such as a mixture of a water-soluble polymer and a metal alkoxide, a vinylidene chloride copolymer, an ethylene vinyl alcohol copolymer (hereinafter, referred to as “EVOH”) is coated on a vapor deposition surface is used. Known (JP-A-8-267637, JP-A-7-8098)
6 etc.).

[0004]

When the gas barrier laminate film is used in the form of a bag, it is used by adhering a heat sealable polyolefin resin or other sealant layer film inside the gas barrier laminate film. However, in this case, sufficient adhesive strength is required. The conventional gas barrier laminate film has problems such as the fact that even if the gas barrier property is high, the adhesive strength of the sealant layer to the film cannot be satisfied, or the gas barrier performance decreases when printing is performed on the deposition surface. Therefore, there is a need for a laminated film having an excellent gas barrier, having an adhesive strength to a sealant layer film, and not deteriorating their performance even when printing is performed on a deposition surface. The present invention has been made in view of the above circumstances, and its object is to have excellent gas barrier properties and high adhesive strength with a sealant layer film. An object of the present invention is to provide a laminated structure that does not deteriorate.

[0005]

Means for Solving the Problems In view of the above-mentioned circumstances, the present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a metal oxide sol can be uniformly applied to a deposition surface of a deposition film. It was found that if this was achieved, a laminated film satisfying the above performance could be obtained, and the present invention was completed. That is, the present invention provides a coating layer formed by coating a metal oxide sol on a vapor-deposited surface of a vapor-deposited plastic film in which a thin film composed of a metal oxide is formed on at least one surface of a base film, The present invention relates to a laminated structure having excellent gas barrier properties, which is obtained by laminating a sealant layer thereon.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The raw material of the base plastic film of the laminated structure of the present invention is not particularly limited as long as it is a resin raw material generally used for films, and polyester, polyamide, polyolefin and the like are used. In the raw materials, known additives, for example, an antistatic agent, a light-blocking agent, an ultraviolet absorber, a plasticizer, a lubricant, a filler, a colorant, a stabilizer, a lubricant, a crosslinking agent, a blocking inhibitor, an antioxidant Etc. can be added. The plastic film of the present invention comprises the above-mentioned raw materials, and may be an unstretched film or a stretched film. Further, a film formed by laminating a plurality of resins may be used.

[0007] Such a plastic film can be manufactured by a conventionally known general method. For example,
The raw resin is melted by an extruder, extruded by an annular die or T die, and quenched to produce a substantially amorphous unoriented film. The unstretched film is subjected to a film flow (vertical axis) direction or a film direction by a conventionally known general method such as uniaxial stretching, tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, or tubular simultaneous biaxial stretching. By stretching in the flow direction and the direction (horizontal axis) perpendicular to the flow direction, a film stretched in at least a uniaxial direction can be produced.
Further, the plastic film has a corona discharge treatment,
A surface treatment by a conventionally known method such as a flame treatment, a plasma treatment, a glow discharge treatment, and a chemical treatment can also be performed.

[0008] The thickness of the above plastic film is in the range of usually 5 to 500 µm, preferably 10 to 200 µm, depending on the application such as mechanical strength, flexibility and transparency as a substrate of the laminated structure of the present invention. Is selected. Further, the width and length of the film are not particularly limited, and can be appropriately selected depending on the application. In addition, an anchor coat agent may be applied to at least one surface of the plastic film. As the anchor coating agent, a solvent-soluble or water-soluble polyester resin, isocyanate resin, urethane resin, acrylic resin, ethylene vinyl alcohol resin,
A vinyl-modified resin, an epoxy resin, an oxazoline group-containing resin, a modified styrene resin, a modified silicon resin, an alkyl titanate, or the like can be used alone or in combination of two or more.

In the laminated structure of the present invention, as the metal oxide deposited on the plastic film, for example, aluminum, silicon, magnesium, palladium,
Metals such as zinc, tin, nickel, silver, copper, gold, indium, stainless steel, chromium, and titanium, oxides of these metals, and mixtures thereof are preferable, and silicon oxide and aluminum oxide are preferable. The method of vapor deposition is generally vacuum deposition, but may be a method such as ion plating, sputtering, or CVD. The thickness of the deposited film is appropriately selected depending on the final use of the deposited film, but is usually preferably 50 to 2,000 angstroms. If it is less than 50 angstroms, it is difficult to obtain a sufficient gas barrier property, and if it exceeds 2000 angstroms, cracks and peeling are likely to occur in the deposited film, which is not preferable.

In the laminated structure of the present invention, a metal oxide sol is coated on a vapor-deposited surface of a vapor-deposited plastic film in which a thin film composed of the above-mentioned metal oxide is formed on at least one surface of a substrate film. The main part is a laminated film which is excellent in gas barrier provided with. Such a laminated film has a water vapor transmission rate of usually 2.0 g / m ² · 24 h or less, preferably 1.0 g / m ^2.
-24 hours or less, oxygen permeability is usually 1.0 cc / m ²
・ 24h ・ atm or less, preferably 0.5cc / m ²・ 24h ・
Less than atm is required.

As the metal oxide sol here, a sol composed of a metal oxide such as silica, antimony, zirconium, aluminum, cerium, titanium or a mixture thereof is preferable, but a silica sol is preferable.
Although the particle diameter of the metal oxide is not limited, it is preferably 4 to 10 nm, and as the particle diameter becomes larger than this range, it becomes difficult to apply, and there is a possibility that satisfactory gas barrier performance cannot be obtained. This metal oxide sol is usually used as an aqueous solution of 10 to 90% by weight, and is preferably used as an alcohol such as alcohols in order to make the coating layer uniform, to improve the workability of coating, or to improve the adhesion to the sealant layer. It may be used after being diluted with a suitable aqueous solvent, a water-soluble polymer such as polyvinyl alcohol, or the like.

As a method of applying the coating solution of the metal oxide sol to the substrate film, generally known methods such as a reverse roll coater, a gravure coater, a rod coater, and an air doctor coater can be used. The thickness of the metal oxide means the thickness of the solid content after drying the coating solution, the thickness,
It is preferably 0.01 to 1.5 μm, particularly preferably 0.1 to 1.5 μm.
The range is from 0.05 to 1.0 μm. If the thickness is less than 0.01 μm, sufficient gas barrier properties cannot be obtained, and
If it exceeds μm, the gas barrier properties are satisfactory, but the adhesion strength to the sealant layer film may be reduced, so that it is not very preferable.

The laminated structure of the present invention is characterized in that a metal oxide sol is coated on a vapor-deposited surface of a vapor-deposited plastic film in which a thin film composed of a metal oxide is formed on at least one surface of a substrate film as described above. On the coating layer of the laminated film provided with the coating layer
It is suitable for use by laminating a sealant layer. As the sealant layer, any resin having heat sealing properties such as polyethylene, polypropylene, ethylene copolymer, and saturated polyester can be used according to the purpose. This sealant layer may be provided by laminating a filmed material, or may be laminated by extrusion coating a molten resin via an adhesive layer made of an anchoring agent. In the case of laminating, the lamination may be performed between the coating layer and the sealant layer via an adhesive layer made of an adhesive. Further, a printing layer may be laminated between the coating layer and the sealant layer. The printing ink for forming the printing layer is not particularly limited, but preferably uses a urethane-based resin as a binder.

Such a laminated structure of the present invention is excellent in gas barrier, and preferably has a water vapor transmission rate of 2.0 g / m 2.
² · 24h or less, the oxygen permeability 1.0cc / m ² · 24h · at
It has a performance of m or less. Further, the value of the adhesion strength measured by the test method described later is also good, and preferably 5
It has a performance of 00 g / 15 mm or more.

[0015]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In addition, the evaluation method of the film in the following Examples is as follows. <Water vapor transmission rate ^{(g / m 2 · 24h)} > water vapor permeability measuring device (manufactured by Modern Controls, Inc., Permatran-
The measurement was carried out using W1) under the conditions of a temperature of 40 ° C. and a relative humidity of 90%. <Oxygen permeability ^{(cc / m 2 · 24h ·} atm)> ASTM-D
The measurement was performed under the conditions of a temperature of 25 ° C. and a relative humidity of 95% using an oxygen permeability measuring apparatus (OX-TRAN100, manufactured by Modern Control Co.) according to 3985.

<Adhesion Strength> Toyo Morton Co., Ltd. is used as an adhesive on the surface of the vapor-deposited film, or on the surface coated with PVA, or on the surface printed thereon.
Urethane adhesive (AD-900: CAT-RT8)
5 = 10: 1.5 mixture). Further, a polyethylene film having a thickness of 50 μm (T-Cello
UX-TC (50 μm) was dry-laminated and aged at 40 ° C. for 3 days. Next, the laminated film was cut into a strip having a width of 15 mm and a length of 100 mm to obtain a test piece. One end of the interface between the polyethylene film of this test piece and the laminated film containing the vapor-deposited film was previously 50
mm, and both release surfaces are autographed (J
Test equipment conforming to IS K7127, Shimadzu Corporation
(Manufactured by DSS-100) and a movable gripper with a distance between the grippers of 100 mm, and the movable gripper was moved 60 mm at a pulling speed of 300 mm / min. The value of the center line of the wavy curve of the load was determined, and the average value of three test pieces was defined as the adhesion strength. In addition, when the test piece was cut during the pulling (this is referred to as film breakage), the tensile load at this time was regarded as the adhesion strength.

(Example 1) An inorganic material having a thickness of about 150 angstroms by evaporating SiO by a high frequency heating method using a vacuum deposition apparatus on a biaxially stretched biaxially stretched polyethylene terephthalate film having a thickness of 12 μm using a vacuum deposition apparatus. A vapor-deposited plastic film having a thin film made of an oxide was obtained. Silica sol (Snowtex XS, manufactured by Nissan Chemical Industry Co., Ltd.)
The average particle diameter of 4 to 6 nm, SiO ₂ content of 20~21wt
%) Containing 20 wt% of isopropyl alcohol was coated so as to have a solid thickness of 0.01 μm, and dried at 80 ° C. for 1 minute. The water vapor transmission rate and the oxygen transmission rate of this laminated film were measured. Further, a polyethylene film was dry-laminated on the laminated film coated with the silica sol as described in the above-mentioned adhesion strength measuring method. The adhesive strength, water vapor transmission rate and oxygen transmission rate of the dry-laminated laminated film were measured. Further, a white ink (NEWLP Super R631 white: SL302 solvent C, manufactured by Toyo Ink Mfg. Co., Ltd.) is applied on the laminated film coated with silica sol.
= 1: 1 mixture), and a polyethylene film was dry-laminated thereon as described in the adhesion strength measurement method above. The adhesive strength, water vapor transmission rate and oxygen transmission rate of the dry-laminated laminated film were measured. Table 1 shows the results of each evaluation.

Example 2 A film was produced in the same manner as in Example 1 except that the solid content thickness was changed to 1.0 μm, and the adhesion strength, water vapor transmission rate and oxygen transmission rate were measured. . Table 1 shows the results of each evaluation. (Example 3) In Example 1, the silica sol (Snowtex 40 manufactured by Nissan Chemical Industries, Ltd., average particle diameter 10 to 2) was used.
0 nm, SiO ₂ content of 40 to 41 wt%), and except that the solid content thickness was 0.1 μm, a film was manufactured by the procedure described in Example 1, and the adhesion strength, water vapor transmission rate and oxygen transmission rate were measured. . Table 1 shows the results of each evaluation.

(Example 4) In Example 1, the thickness of the solid was 0.1 μm, and the mixing ratio of the solid was SiO 2: PVA.
= 8: 2 (weight ratio) by adding silica sol to PVA
(Poval, N-300, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
A film was manufactured by the procedure described in Example 1 except that the film was diluted with an aqueous solution of Example 1, and the adhesion strength, water vapor transmission rate and oxygen transmission rate were measured. Table 1 shows the results of each evaluation. (Example 5) In Example 4, the solid content thickness was set to 1.0 μm.
A film was manufactured in the same manner as in Example 1 except that the value was changed to m, and the adhesion strength, the water vapor transmission rate and the oxygen transmission rate were measured.
Table 1 shows the results of each evaluation.

(Example 6) In Example 4, the diluted aqueous solution of silica sol was converted to an aqueous solution of EVOH (Soarnol, 16DX manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and the isopropyl alcohol content in the aqueous solution was adjusted to 50 wt%. Manufactured a film according to the procedure described in Example 1, and measured the adhesion strength, the water vapor transmission rate and the oxygen transmission rate. Table 1 shows the results of each evaluation. (Example 7) In Example 1, the thickness of the solid content was set to 2.0 μm.
A film was manufactured in the same manner as in Example 1 except that the value was changed to m, and the adhesion strength, the water vapor transmission rate and the oxygen transmission rate were measured.
Table 1 shows the results of each evaluation.

Example 8 The procedure of Example 1 was repeated, except that the silica sol was diluted with an aqueous PVA solution so that the mixing ratio of solids was SiO ₂ : PVA = 5: 5 (weight ratio). A film was manufactured according to the procedure, and the adhesion strength, the water vapor transmission rate and the oxygen transmission rate were measured. Table 1 shows the results of each evaluation. (Example 9) In Example 1, the solid content thickness was set to 0.00.
A film was manufactured by the procedure described in Example 1 except that the thickness was changed to 5 μm, and the adhesion strength, the water vapor transmission rate and the oxygen transmission rate were measured. Table 1 shows the results of each evaluation.

Comparative Example 1 A film was produced in the same manner as in Example 1 except that the step of coating with silica sol was omitted, and the adhesion strength, water vapor transmission rate and oxygen transmission rate were measured. Table 1 shows the results of each evaluation. (Comparative Example 2) In Example 1, an aqueous solution of PVA (Poval, N-300, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) containing no silica sol without coating with silica sol had a solids thickness of 0.1 μm. Except for coating as described above, a film was manufactured according to the procedure described in Example 1, and the adhesion strength, water vapor transmission rate and oxygen transmission rate were measured. Table 1 shows the results of each evaluation.

(Comparative Example 3) In Example 1, the silica sol was not coated, and the EVO containing no silica sol was used.
H (Soarnol, 16D manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
X) A film was manufactured by the procedure described in Example 1 except that the aqueous solution was coated so that the solid content thickness became 0.01 μm, and the adhesion strength, the water vapor transmission rate and the oxygen transmission rate were measured. Table 1 shows the results of each evaluation.

[0024]

[Table 1]

[0025]

The laminated structure of the present invention has a sufficient gas barrier property, a high adhesive strength with the sealant layer, and furthermore, their performance is deteriorated even when printing is performed on the vapor deposition surface. No.

Continued on the front page F-term (reference) 4F100 AA17B AA17C AA20C AK01A AK04 AK21C AK41 AK51G AR00D AR00E BA03 BA04 BA05 BA07 BA10A BA10C BA10D BA25C CB00 EH46C EH461 EH661 GB15 GB41 HB31J02 JD05J02 JD05J02

Claims (8)

[Claims] 1. A coating layer formed by coating a metal oxide sol on a vapor-deposited surface of a vapor-deposited plastic film in which a thin film made of a metal oxide is formed on at least one surface of a substrate film. A laminated structure having excellent gas barrier properties, characterized by laminating a sealant layer on a laminate. 2. The laminated structure having excellent gas barrier properties according to claim 1, wherein a printed layer is laminated between the coating layer and the sealant layer. 3. The laminated structure having excellent gas barrier properties according to claim 1, wherein the water vapor permeability is 2.0 g / m ² · 24 h or less and the oxygen permeability is 1.0 cc / m ² · 24 h · atm or less. . 4. The laminated structure having excellent gas barrier properties according to claim 1, wherein the laminated structure has an adhesion strength of 500 g / 15 mm or more. 5. A metal oxide sol-coated coating layer is provided on a vapor-deposited surface of a vapor-deposited plastic film in which a thin film made of a metal oxide is formed on at least one surface of a base film, and water vapor transmission is provided. The rate is 2.
0 g / m ² · 24 h or less, oxygen permeability 1.0 cc / m ² ·
A laminating film excellent in gas barrier properties, characterized in that the thickness is 24 h · atm or less. 6. The coating layer having a thickness of 0.01-1.
The film for lamination according to claim 5, which has a thickness of 5 µm. 7. The laminating film according to claim 5, wherein the metal oxide sol is a silica sol. 8. The laminating film according to claim 5, wherein the metal oxide sol is an aqueous liquid containing polyvinyl alcohol.