JP2000167968A - Highly moisture resistant laminated body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of pinholes even when suffered a curvature effect iteratively by forming a high moisture resistance layer with a composite film of a three-layer structure formed by metal foil, a reinforced resin layer, and metal foil laminated in this order. SOLUTION: The highly moisture resistant laminated body 10, in a laminated body comprising at least a base material film 2, a highly moisture resistant layer 1 and a heat seal layer 7, consists of a composite film of a three-layer structure formed having a highly moisture resistant layer 2 made up of metal foil 3, a reinforced resin layer 4, and other metal foil 5 as required via an adhesive. Also, the reinforced resin layer 4 comprises a nylon film, and each metal foil 3 and 5 is aluminum foil having a thickness of 6-12 μm, so that it is an antistatic highly moisture resistant laminated body having an antistatic layer 8 and antistatic heat seal layer containing an antistatic agent on the surface of the base material film 2 of the highly moisture resistant laminated body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high seal formed by heat sealing (hereinafter, heat seal is referred to as HS) for packaging electronic parts and the like whose functions are destroyed even by a very small amount of moisture. More specifically, the present invention relates to a high-moisture-proof laminate that does not impair its moisture-proof effect even if the laminate repeatedly undergoes a bending action, and an antistatic high-moisture-proof laminate based on the laminate. Belong to the body.

[0002]

2. Description of the Related Art Hitherto, a multilayer laminate having a plastic film as a base material has been used to prevent packaged contents from being adversely affected by moisture and deteriorating quality.
For example, a laminate of a vinylidene chloride coat film, a metal foil, or a plastic film having excellent water vapor barrier properties, a metal foil laminated on a plastic film, or an inorganic oxide vapor-deposited film, and a heat sealant layer (hereinafter, the heat sealant layer is an HS layer) ) Are laminated.

However, the conventional high-moisture-proof laminate is not always satisfactory when it is used for a long period of time (the storage period is 2 to 8 years). For example, those using a vinylidene chloride coated film not only do not have a sufficient water vapor barrier, but the vinylidene chloride undergoes chemical decomposition during the storage period, and the product adversely affects the contents. There was also that. In addition, aluminum foil, which is a metal foil having higher moisture resistance, is manufactured in a defect-free state, and if maintained in that state, it can sufficiently block water vapor, light and oxygen even with a thickness of 10 μm or less. Can be. However, it is almost impossible to completely prevent the occurrence of pinholes in the rolling process when producing the foil. For example, an aluminum foil having a thickness of 12 μm has a thickness of ^{2 to} 9 pieces / m ² , and an aluminum foil having a thickness of 7 μm has a thickness of 100 pieces / m ^2.
There is also a document that the above pinholes exist (see Aluminum Foil Handbook, edited by Sun Aluminum Co., Ltd.). Generally, the moisture permeability of aluminum foil is 0 g / m ^2.
-It is considered 24 hrs. However, in a measurement with accuracy, a 0.1 μm thick aluminum foil has a thickness of 0.1 μm.
If 9~2.4g / m ² · 24hrs, the thickness of 7μm also a result of the 3.0~7.0g / m ² · 24hrs, variations due to the presence of pinholes is remarkable.

[0004] Even a thick aluminum foil manufactured with relatively few pinholes has a smaller elongation than a plastic film, and can be used for laminating an aluminum foil with another film or for a bag filled with protruding contents. Pinholes and tears, which are difficult to determine visually, may easily occur due to repeated fatigue of bending during transportation, and as a result, there is a problem in that the originally set moisture-proof property cannot be exhibited.

[0005] Usually, the thickness of the aluminum foil used for the laminated body which is required to have a high moisture-proof property is set to 12 µm or more. However, the aluminum foil having a thickness of 12 μm or more is not only inferior in workability because the density is almost three times as compared with other plastic films, but also reduces the pinholes generated during actual work by 7 to 9 μm. There is a problem that it is not easy to reduce the thickness as compared with the thickness of the object.

[0006] In some cases, a bag is used as an inner / outer bag, and the inner bag is filled with contents and a desiccant is sealed in the middle of the outer bag. However, the desiccant powder adheres to the contents, and the double packaging has poor workability, and has problems not only of cost but also of increased waste.

[0007] An example in which the shelf life of a bag made of aluminum foil is limited to one year or less as a packaging material for retort foods that has been subjected to the same sterilization process as canned foods is due to the pin formed on the aluminum foil. This is due to the hole.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a highly moisture-proof bag used for packaging electronic parts and the like whose functions are destroyed even by a very small amount of moisture in a laminate using a highly moisture-proof metal foil. It is an object of the present invention to provide a high-moisture-proof laminate of 0.1 g / m ² · 24 hrs or less in a laminate for supplying a body, which prevents pinholes even when repeatedly subjected to a bending action and does not impair the moisture-proof effect. Is what you do.

[0009]

In order to solve the above problems,
In a laminate comprising at least a base film, a high moisture-proof layer, and an HS layer, the high moisture-proof layer is a composite film having a three-layer structure in which a metal foil, a reinforced resin layer and a metal foil are arranged in this order. It is a highly moisture-proof laminate. Further, it is a high moisture-proof laminate in which the reinforced resin layer of the previous period is made of a nylon film. And it is a high moisture-proof laminated body which is the aluminum foil whose thickness of the said metal foil is 6-12 micrometers. The antistatic layer and the HS layer on the outer surface of the base film are an antistatic high moisture-proof laminate containing an antistatic agent.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, the high moisture-proof laminate of the present invention is a laminate comprising at least a base film 2, a high moisture-proof layer 1 and an HS layer 7, Is a high-moisture-proof laminate 1 consisting of a three-layer composite film in which the metal foil 3, the reinforced resin layer 4, and the further metal foil 5 are optionally interposed via adhesives 13 and 14 shown in FIG.
0. Further, the reinforced resin layer 4 is a highly moisture-proof laminated body 10 made of a nylon film. The metal foils 3 and 5 are the high moisture-proof laminated body 10 which is an aluminum foil having a thickness of 6 to 12 μm. Then, as shown in FIG. 2, the antistatic layer 8 and the antistatic HS layer 71 on the outer surface of the base film 2 of the base film 10 are an antistatic high moisture-proof laminate 101 containing an antistatic agent. .

The high moisture-proof layer of the present invention has a three-layer structure in which a plastic film is laminated as a reinforced resin layer between two metal foils (mainly aluminum foil). Therefore, even if pinholes are generated in each of the metal foils at the time of rolling or processing, it is extremely unlikely that the metal foils are concentrated on the same portion of the two laminated metal foils. The metal foil is not particularly limited as long as it can be formed into a normal thin film.
It can be arbitrarily selected from gold, brass, iron, tin and the like, and is preferably an aluminum foil excellent in productivity. The aluminum foil used in the present invention is excellent in flexibility, adhesive suitability, and the like. Therefore, a soft aluminum foil that has been sufficiently degreased and annealed by heat treatment after rolling is preferable. The thickness of the aluminum foil is preferably 6 to 12 μm. If the thickness is 6 μm or less, it is difficult to process. If the thickness is 12 μm or more, the number of pinholes is small. However, even when the thickness is 12 μm or less, the high moisture barrier layer of the present invention can sufficiently exert its effect.
Therefore, those having a size of 12 μm or more waste resources.

As the reinforced resin layer, a stretched or non-stretched film of a thermoplastic resin having high piercing strength and bending strength can be used. For example, polyamides such as 6 nylon and 66 nylon, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polypropylene, high density polyethylene, polybutene, ethylene
And saponified vinyl acetate copolymer. The reinforced resin layer is formed by laminating a film-forming material via an adhesive,
Sandwich lamination can also be performed by melt extrusion coating using the reinforced resin itself as an adhesive resin layer.

The base film used in the present invention determines surface properties such as gloss and rigidity and strength of the laminated material. For example, polyolefin resins such as polyethylene and polypropylene, polystyrene, polyvinyl chloride, polyamide, acrylic resin containing acrylate or methacrylate as a main component, polyethylene terephthalate, polybutylene terephthalate, polyester such as polyethylene naphthalate, polyacetal And cellophane, synthetic paper, etc., as well as stretched or unstretched films made of cellulose di- or triacetate, polycarbonate or the like. Or these stretched film aluminum, aluminum oxide,
Those on which silicon oxide, indium oxide, or the like has been deposited can also be used. In particular, the thickness of the biaxially stretched film of polyester, polypropylene or polyamide is 6 to 50.
A film having a thickness of μm is preferred as a base film having excellent processability such as printability, lamination suitability, and coating suitability.

The lamination of the base film and the aluminum foil, or the aluminum foil and the reinforced resin layer is performed by dry lamination using a reaction-curable adhesive, petroleum wax, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer. Hot-melt lamination with hot-melt adhesives (including hot lacquers that are used in a heated state with a solvent added) consisting of polymers, ethylene-acrylate copolymers, ionomers, synthetic rubbers, tackifiers, etc. Alternatively, it is appropriately selected and used depending on the material and application using a conventional method such as sandwich lamination in which a primer is provided as necessary and laminated via an adhesive resin layer which is melt-extruded.

In the heat sealant layer of the present invention, most thermoplastic resins can be used in addition to polyolefin resins.
For example, low density polyethylene (hereinafter referred to as LDPE), medium or high density polyethylene, linear polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer Polyolefin resins such as coalesced and ionomer resins can be preferably used in view of HS strength.

The HS layer can be formed by using a normal circular die or T die. The thickness is preferably 15 to 60 μm, and can be slightly increased or decreased depending on the material and application. Needless to say, not only a single-layer film but also a multilayer film can be used. In addition, the HS layer is not only a formed thermoplastic resin layer,
Polyamide, vinyl chloride / vinyl acetate copolymer, polyvinylidene chloride, ethylene
Vinyl acetate copolymer, ethylene / acrylic acid copolymer,
Ethylene acrylate copolymers, polyolefin resins such as ionomers, solutions of polyesters, and so-called hot lacquer solutions in which the dispersion is in a solution state at room temperature or by heating, or the above materials are in a molten state Can be used by extrusion coating.

As the adhesive resin layer for interposing the adhesion between the high moisture-proof layer and the HS layer of the present invention, almost any material can be used as long as it is a material used for adhesion of a non-absorbable film. For example, low- and medium-density polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene-maleic anhydride copolymer, ethylene-acrylic acid can be used for sandwich lamination of hot-melted resin An adhesive resin layer having a thickness of 15 to 25 μm can be formed from a copolymer, an ethylene / acrylate copolymer, an olefin resin such as an ionomer, or the like. Preferred are ethylene-acrylic acid copolymers and ethylene-acrylic acid ester copolymers, which are copolymers of carboxyl groups and olefins, which are excellent in workability and excellent in adhesion to LDPE or metal foil. Then, in order to make the adhesion between the high moisture-proof layer and the adhesive resin layer strong and stable, a primer made of polyester / isocyanate, urethane-based resin, alkyl titanate, etc. was applied to the high moisture-proof layer or melted. It is preferable to perform an ozone treatment or the like on the adhesive resin. Of course, it is also possible to bond the high moisture-proof layer and the HS layer by dry lamination using a polyester-isocyanate, polyether-isocyanate or urethane-based resin instead of the adhesive resin layer.

The antistatic layer of the present invention can be provided with a varnish obtained by dissolving a normal low molecular weight antistatic agent or a crosslinked high molecular weight antistatic agent in a solvent such as water or alcohol by a normal printing method. . For example, a nonionic surfactant which is an ester of a polyhydric alcohol and a fatty acid, an anionic surfactant exemplified by an alkyl salt of sulfonic acid, and a nonionic surfactant exemplified by an N-acyl (C ₄ -C ₁₈ ) sarcosinate Acrylic ester having a quaternary ammonium base, preferably a polymer having excellent water resistance, such as an ionic surfactant or a cationic surfactant such as dimethylalkyl (C ₄ -C ₁₈ ) ammonium chloride. And an antistatic agent comprising a copolymer of an acrylic ester and a methacrylic ester, polyethyleneimine, and a glycidyl compound.

The preferred antistatic layer according to the present invention comprises a quaternary ammonium base-containing acrylate, a copolymer of acrylate, acrylate and methacrylate, polyethyleneimine having an average molecular weight of 300 to 2,000. And a glycidyl compound. (Hereinafter, in this specification, it is described as a cross-linking type antistatic agent.) Examples of the glycidyl compound include polyglycidyl ether of polyhydric alcohol, polyglycidyl ether of carboxylic acid, and the like. In addition, examples of glycidic acid include epihydric acid.

The above antistatic agent is prepared by dissolving one or more mixtures in a mixed solvent of water and alcohol. Then, in order to give coating suitability (viscosity suitable for the coating process, thixotropic, etc.), methyl cellulose, ethyl cellulose, nitrocellulose, polyvinyl alcohol,
Binders such as starch and ammonium polyacrylate and extenders such as silica, calcium carbonate and aluminum oxide can also be added. The thickness of the coating is 0.05 to 4 μm (a numerical value obtained by measuring the weight and converting the area into a thickness), preferably 0.1 to 1 μm.
By leaving 0.1 to 100 ppm of water on the coated surface, an effective antistatic effect is exhibited.

Hereinafter, the present invention will be described in more detail based on experimental examples. (Example 1) As shown in FIG. 3, a 6 μm thick biaxially stretched polyester film (base film 2) having a thickness of 6 μm was
m and one surface of an aluminum foil (metal foil 3) were laminated by dry lamination. Then, the other side of the aluminum foil 3 is coated with a polyurethane adhesive 13 to a thickness of 15 μm.
m of a stretched nylon film (reinforced resin layer 4), and further, an aluminum foil (metal foil 5) was dry-laminated with an adhesive 14 of the same material as above.
Then, a linear polyethylene film (HS layer 7) having a thickness of 50 μm was laminated on the side of the aluminum foil 5 using LDPE (adhesive resin layer 6 having a thickness of 20 μm) to form a highly moisture-proof laminate 10 of the present invention.

Example 2 An aluminum foil was replaced with a biaxially oriented polyester film (reinforced) in the same manner as in Example 1 except that the stretched nylon film 4 having a thickness of 15 μm in Example 1 was replaced with a biaxially oriented polyester film having a thickness of 12 μm. A high moisture-proof laminate 10 of the present invention of Example 2 having a high moisture-proof layer 1 provided on both surfaces of the resin layer 4) was constructed.

Example 3 The present invention of Example 3 having a high moisture-proof layer 1 in the same manner as in Example 1 except that the aluminum foil 3 of Example 1 was 9 μm in thickness and the aluminum foil 5 was 12 in thickness. The highly moisture-proof laminated body 10 of the above was constituted.

Example 4 As shown in FIG. 4, polyurethane-based primers 16 and 17 were provided on both sides of the stretched nylon (reinforced resin layer 4) of Example 1, and a 15 μm thick LDPE (adhesion) was provided on both sides. Using the resin layers 18 and 19), sandwich lamination was performed with a melt extruder to form a high moisture-proof layer 11 in which aluminum foils 3 and 5 were laminated. Further, a stretched polyester film 2 having a thickness of 12 μm was laminated via an aluminum foil 3 and a urethane adhesive 12 in the same manner as in Example 1. Then, a 50 μm-thick linear polyethylene film 7 is laminated as an HS layer 7 on the side of the other aluminum foil 5 via LDPE (adhesive resin layer 6 having a thickness of 20 μm) to form a highly moisture-proof laminate 102 of the present invention. Configured.

(Embodiment 5) As shown in FIG. 2, a quaternary acrylate ester and a methacrylate ester were formed on one side of a 12 μm-thick stretched polyester film (base film 2) used in Example 1. An alcohol solution of a crosslinkable antistatic agent comprising a copolymer of the above, a mixture of polyethyleneimine and a glycidyl compound was applied by roll coating to provide an antistatic layer 8. Further, the above-mentioned antistatic agent was added to a linear polyethylene film having a thickness of 50 μm in an amount of 0.0
The conductive HS layer 71 dispersed by 1 part by weight is sandwich-laminated on the aluminum foil 5 via the adhesive resin layer 6 in the same manner as the HS layer 7 of Example 1 to obtain the antistatic high moisture-proof laminate 101 of the present invention. Configured.

(Comparative Example 1) As shown in FIG.
The thickness (12 μm) of the 2 μm biaxially stretched polyester film 2 on the easily-adhesive treated surface using a polyurethane-based adhesive 12.
m) and one surface of the aluminum foil 3 were laminated by dry lamination. Then, a stretched nylon film 4 having a thickness of 15 μm was laminated on the other side of the aluminum foil 3 using a polyurethane adhesive 13. Next, a linear polyethylene film (HS layer 7) having a thickness of 50 μm is stretched on stretched nylon 4 via a primer 9 to form an LDP having a thickness of 20 μm.
Using E (adhesive resin layer 6), sandwich lamination was performed to form a moisture-proof laminate 105 of Comparative Example 1 of the present invention.

Comparative Example 2 A moisture-proof laminate 105 of Comparative Example 2 of the present invention was constructed in the same manner as in Comparative Example 1 except that the thickness of the aluminum foil 3 of Comparative Example 1 shown in FIG. 5 was changed to 6 μm. .

Comparative Example 3 As shown in FIG. 6, except that the layer order of the stretched nylon film 4 and the aluminum foil 3 was changed, Comparative Example 3 of the present invention was performed in the same process as Comparative Example 1.
Was formed.

Table 1 shows the results of evaluating the water vapor permeability, the degree of pinhole occurrence after the bending test, and the antistatic effect using the laminates prepared in the examples and comparative examples. Water vapor permeability: The water vapor permeability based on JIS Z0222 is evaluated in terms of g / m ² · 24 hours using the test pieces prepared before and after the rubbing treatment prepared in the pinhole test. -Gelboflex test: The samples of Example 1 and Comparative example 1 were cut into A4 size, and a load of 100 times bending was applied by a gelboflex tester to evaluate the number of generated pinholes and water vapor permeability. Pinhole test: The laminates of the above Examples and Comparative Examples were cut into 15 × 15 cm ² , and both sides of one side were held with both hands to rub the laminates ten times to prepare test pieces. On the other hand, 13 × 13 × 13 cm ³ equipped with a 20 W fluorescent lamp
A dark box provided with a circular window having a diameter of 10 cm on one side of the cube was prepared. Then, the laminated body before and after the rubbing treatment was placed on a window, and some of the pinholes were visually evaluated. (Evaluation criteria) A: No pinhole. ：: Generation of 10 or less pinholes is observed. X: Ten or more pinholes are observed.・ Antistatic effect: With the polyester side of the laminated material facing up,
This ash was adhered under the condition of 25 ° C. and a relative humidity of 60%, and after standing for 2 seconds, the laminated material was vertically set to evaluate the ash adhesion state. (Evaluation criteria) ：: No ash adhered. X: Ash significantly adheres and remains.

[0030]

[Table 1] *: Gelbo test values indicate water vapor (water vapor permeability, 1 g / m ² · 24H) and pins (number of pinholes generated) after treatment.

[0031]

As described in detail above, the laminate of the present invention comprising a three-layer high moisture-proof layer in which a reinforcing resin layer is inserted into a two-layer metal foil has excellent moisture-proof properties, and Even after the bending test, it has the effect of suppressing the generation of pinholes. Therefore, the laminate of the present invention can maintain moisture-proof properties not only in the manufacturing process but also in the distribution process after filling the contents, and thus has an excellent effect of preserving the contents. In addition, the base film of the laminate of the present invention, and those having an antistatic effect on the HS layer,
It has not only moisture-proof properties but also an antistatic action, and is effective in preserving electronic components and the like. It is needless to say that the laminate using the metal foil is excellent not only in the above-described moisture-proof property but also in the barrier property of light and gas.

[Brief description of the drawings]

FIG. 1 is a basic cross-sectional schematic view of a laminate of the present invention.

FIG. 2 is a schematic cross-sectional view showing a configuration of the laminate of the present invention to which an antistatic property is added.

FIG. 3 is a schematic cross-sectional view for explaining an embodiment of the laminate of the present invention.

FIG. 4 is a schematic sectional view showing another configuration of the laminate of the present invention.

FIG. 5 is a schematic sectional view showing a configuration of a laminate of a comparative example.

FIG. 6 is a schematic cross-sectional view showing another configuration of the laminate of the comparative example.

[Explanation of symbols]

 1, 11 High moisture-proof layer 2 Base film (polyester film) 3, 5 Metal foil (aluminum foil) 4 Reinforced resin layer (nylon film) 6, 18, 19 Adhesive resin layer 7 HS layer 8 Antistatic layer 9, 16, 17 Primer 10, 101, 102 High moisture proof laminate 12, 13, 14 Adhesive 71 Antistatic HS layer 105, 106 Moisture proof laminate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65D 85/38 B65D 85/38 CF term (Reference) 3E086 AD01 BA04 BA13 BA15 BB02 BB35 BB51 CA31 3E096 BA08 CA12 EA02X FA02 GA01 4F100 AB10B AB10E AB33B AB33E AK01D AK06G AK42A AK48C AK51G AK63D AT00A BA05 BA07 BA10A BA10D BA13 CA22D DA01 EJ38A GB16 JD04 JK12 JK20 JL12D

Claims (4)

[Claims] 1. A laminate comprising at least a substrate film, a high moisture-proof layer and a heat sealant layer, wherein the high moisture-proof layer is formed of a metal foil, a reinforced resin layer and a metal foil in the order of three layers. A highly moisture-proof laminate characterized by being a composite film having a structure. 2. The high moisture-proof laminate according to claim 1, wherein said reinforced resin layer is a nylon film. 3. The high moisture-proof laminate according to claim 1, wherein said metal foil is an aluminum foil having a thickness of 6 to 12 μm. 4. An antistatic high moisture-proof laminate, wherein the antistatic layer and the heat sealant layer contain an antistatic agent on the outer surface of the base film.