JP3368663B2 - Antibacterial packaging material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial packaging material having a bactericidal property or an antibacterial property, which is used as a packaging material used for medicines, foods, commodities for which hygienic sterilization or antibacterial property is required.

[0002]

2. Description of the Related Art Conventionally, packaging materials used for medicinal products, foods, products requiring hygienic sterilization or antibacterial properties are
As a means for imparting sterilization or antibacterial properties to a package, there are various methods such as an ultraviolet irradiation method using an ultraviolet lamp, an ozone oxidation method, and a cleaning method using a sodium hypochlorite solution, which are selected according to the purpose. ing. Further, silver zeolite or a metal material is used as an antibacterial agent by kneading it into a resin or coating it on the surface, thereby similarly imparting sterilization or antibacterial properties to the article. It should be noted that it is virtually impossible to knead or coat the surface of a resin with a sterilizing chemical or the like in the packaging material used for an article that is in direct contact with such medicines and foods, and it is safe to use. Those having excellent bactericidal or antibacterial properties are desired.

[0003]

However, the above-mentioned ultraviolet irradiation method and ozone oxidation method require a device for generating ultraviolet rays and ozone, and cause surface discoloration and deterioration of the resin of the article to be sterilized. Alternatively, when the processing is performed for a long time, there is a problem that the effect on the human body cannot be ignored.

In addition, an antibacterial agent is kneaded into the resin in advance,
When it is used as a material, only the antibacterial agent that bleeds out on the surface of the article is effective, so the antibacterial agent existing inside the resin cannot exert its effect, and the antibacterial agent exposed on the surface is also effective. In order to increase the amount of the agent, it is necessary to mix a large amount, and addition of the antibacterial agent has a problem that the physical properties of the resin such as mechanical strength, weather resistance and durability are deteriorated.

Further, when applied to an article, it is necessary to expose the surface of the antibacterial agent at a high concentration in order to effectively retain and exhibit the bactericidal and antibacterial effects of the antibacterial agent.
The addition of the coating liquid to the binder resin causes a decrease in physical properties, and there is a problem such as peeling of the coated surface during use of the article.

[0006] Therefore, an object of the present invention is to provide an antibacterial packaging material which can be used as a packaging material and can retain the antibacterial property for a long period of time.

[0007]

The present invention has been made to solve the above problems, and the invention according to claim 1 is such that a metal oxide or a carbide is provided on one surface of the heat-adhesive film.
The insulating thin film layer, the antibacterial metal thin film layer, the adhesive layer, and the base film are sequentially laminated, and a large number of small holes penetrating the thermal adhesive film and the insulating thin film layer are formed. It is a characteristic antibacterial packaging material.

[0008]

The invention according to claim 2 of the present invention is the above contract.
The antibacterial packaging material according to claim 1, wherein the antibacterial gold is
The thin metal layer is characterized by being either silver or copper
It is an antibacterial packaging material.

The invention according to claim 3 of the present invention is the antibacterial packaging material according to claim 1 or claim 2, wherein:
A printing layer is formed on at least one side of the base film.
It is an antibacterial packaging material characterized by being

[0011]

The antibacterial packaging material according to claim 1 of the present invention comprises:
Insulation made of metal oxide or carbide on heat-adhesive film
Provided on the insulating thin film layer by sequentially laminating the thin film layer, the antibacterial metal thin film layer, the adhesive layer, and the base film, and forming a large number of small holes penetrating the heat adhesive film and the insulating thin film layer. free antimicrobial metal ions adsorbed on the porous portion formed on the insulating thin film layer from the obtained antimicrobial metal thin film layer,
It is stored and gradually elutes or oozes out through the pores of the base film to the surface of the base film, thereby exhibiting antibacterial properties. Since the metal gradually elutes through the small holes of the base film to give antibacterial properties, it is possible to maintain safety and stable antibacterial properties for a long period of time.

In addition, a metal oxide or
Has an anchoring function to further improve the adhesion between the heat-adhesive film and the antibacterial metal thin film layer by providing an insulating thin film layer made of carbide , and when forming small holes, this thin film is formed. The small holes can be easily formed by utilizing the charging at the time.

An antibacterial packaging material according to claim 2 of the present invention
According to the report, the antibacterial metal thin film layer made of silver or copper is used for
Separated silver or copper antibacterial metal ions in the insulating thin film layer
It is adsorbed and stored in the formed porous parts, and the base material film is gradually added.
Leach or ooze to the surface of the base film through the holes in the rum
And silver or copper antibacterial metal ion bacteria / bacteria
Antibacterial properties can be exhibited by the growth-suppressing effect of

Furthermore, according to the antibacterial packaging material of claim 3 , a design can be imparted by forming a printing layer on at least one surface of the substrate film, and a packaging material with high designability can be provided. You can

[0015]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the antibacterial packaging material of the present invention, FIG. 2 is a schematic diagram illustrating an example of an antibacterial packaging material manufacturing apparatus of the present invention, and FIG. FIG. 3 is a schematic view for explaining formation of an insulating thin film layer and porosity on a base film of the antibacterial packaging material.

In the antibacterial packaging material 1 of the present invention shown in FIG. 1, a base film 6 is sequentially laminated on a heat adhesive film 2 with an insulating thin film layer 3, a metal thin film layer 4 and an adhesive layer 5 interposed therebetween. The heat-adhesive film 2 and the insulating metal layer 3 have a large number of small holes 7 penetrating both layers.

The heat-adhesive film 2 is made of a resin selected from polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ionomer resin and the like. It is a film-like or sheet-like resin that can be melt-bonded by. 80-200 especially for heat sealing
It is preferable that it is possible at about 0 ° C., and it is also possible to use a blend of the above resins or a heat-adhesive film having a multilayer structure of two or more layers.

The layer thickness of the heat-adhesive film 2 is not particularly limited, but one having a thickness of about 6 to 200 μm is practically used. When the layer thickness is less than 6 μm, the sealing strength may be insufficient when melt-bonding by heat during processing into a package, and the package may be broken. On the other hand, if the layer thickness exceeds 200 μm, it becomes difficult to uniformly form the small holes 5 formed therethrough.

The insulating thin film layer 3 is made of magnesium (M
g), a compound thin film made of a compound such as an oxide or a carbide of a metal such as aluminum (Al), silicon (Si), zirconium (Zr), titanium (Ti) or zinc (Zn), and having the above characteristics It is not particularly limited as long as it is. Considering the processability of forming the small holes 7 together with the thermal adhesiveness 2 by utilizing the charging of the thermal adhesive film 2 described below, the surface resistance value of the insulating film layer 3 is 10 ¹⁵ (Ω.
/ □) or more is preferable.

The layer thickness of the insulating thin film layer 3 is 2 to 500 nm.
The range is preferably 10 to 200 nm. 5
If the thickness is more than 00 nm, the thin film is cracked and the thin film falls off from the surface of the heat-adhesive film 2, which is not preferable. On the other hand, if the thickness is less than 2 nm, not only the adhesiveness with the metal thin film layer is poor, but also the problem of small hole processing with the thermal adhesive film 2 utilizing the charging property of the insulating thin film described below occurs. As a method for forming the insulating thin film layer 3, a known dry process such as a vacuum vapor deposition method, a sputtering method, a plasma vapor deposition method, an ion plating method can be used. In particular, in the vacuum vapor deposition method, by using the long heat-adhesive film 2, it is possible to process a large amount continuously at high speed and at low cost.

The metal thin film layer 4 is made of silver (Ag), copper (C).
u), titanium (Ti), zinc (Zn), zirconium (Zr), gold (Au), iron (Fe), tin (Sn) and other metals, and oxides or other compounds thereof exhibit antibacterial properties Even if a material is selected and other than those listed above, any metal material exhibiting antibacterial properties can be used.
The layer thickness of the metal thin film layer 4 is in the range of 5 to 500 nm and is 5
When the thickness is less than nm, the antibacterial property is insufficient and 500
If the thickness is greater than nm, there is a problem that the insulating thin film layer 3 or the heat-adhesive film 2, which is the lower layer, may fall off. The range is preferably 5 to 200 nm.

The method for forming the metal thin film layer 4 is the same as the method for forming the insulating thin film layer 3 described above, and a known dry process such as a vacuum deposition method, a sputtering method, a plasma deposition method or an ion plating method is used. be able to. In the same manner, according to the vacuum vapor deposition method, it is possible to continuously process the long-sized heat-adhesive film 2 at a high speed and inexpensively in large quantities.

Next, according to the method of forming a large number of fine small holes through the heat-adhesive film 2 having the insulating thin film layer 3 according to the present invention, the inside of the vacuum container 20 is formed by the vapor deposition apparatus B shown in FIG. Thermal adhesive film 2 supplied from unwinding roll 25
The vapor deposition source 22 is moved to the electron beam 2 by the electron beam heating method.
It is heated and evaporated by 3, and cooled by the metal roll 21 to continuously form the insulating thin film layer 3, and is wound by the winding roll 27 via the guide roll 26. Here, small holes are formed in the heat-adhesive film 2 and the insulating thin film layer 3 by utilizing the arc discharge 24 generated when peeling from the metal roll 21. That is, a thin film of an insulating thin film material is formed on the heat-adhesive film 2 by an electron beam method, and at this time, the insulating thin film layer 3 is charged by reflected electrons or secondary electrons generated by irradiation of the electron beam 23. At the same time, a reverse potential is induced on the surface of the heat-adhesive film 2 on the side in contact with the metal roll 21, and when the heat-adhesive film 2 separates from the metal roll 21, an arc discharge 24 is generated, which causes heat adhesion. A large number of small holes can be easily formed in the flexible film 2.

Further, regarding the number and the diameter of the small holes 7 formed in the heat-adhesive film 2 and the insulating thin film layer 3, the plasma discharge part which is usually used for removing the charge of the heat-adhesive film 2 to be vapor-deposited in FIG. By adjusting various parameters of 28, the charging can be controlled, that is, the number of small holes and the diameter can be controlled. It should be noted that the number and size of the small holes generated in these controls vary depending on the type and thickness of the heat-adhesive film 2 used and the type and thickness of the insulating thin film layer 3, but generally, plasma is generated. It can be controlled by changing the supply power 29 supplied to the discharge part 28, the composition of the gas 30 for plasma generation, and the discharge pressure.

As a method of manufacturing the small holes formed in the heat-adhesive film 2 and the insulating thin film layer 3, a laser method, a hot needle penetration method, a diamond roll method, etc. may be used in addition to the arc discharge due to the above charging. You can

The opening diameter of the small hole 5 formed by penetrating the heat-adhesive film 2 and the insulating thin film layer 3 in the present invention is
It is preferably about 0.1 to several tens of μm. When it is 0.1 μm or less, the elution of metal ions from the metal thin film layer 4 becomes small and the antibacterial property becomes insufficient, and when it is more than several tens μm, the elution rate of metal ions from the metal thin film layer 4 becomes large and the initial Although it has excellent antibacterial properties, it has a problem that its antibacterial effect decreases with time.

The number of holes is based on the hole density, and the hole density is 1
It is 0 to 100 pieces / cm ² . If the number is less than 10, the antibacterial property is insufficient, and if the number is more than 100, the base film 2
Has a problem of lowering mechanical strength.

The base material film 6 is mainly made of various natural resins, synthetic polymer resins in the form of a film or sheet, paper, non-woven fabric, etc., but is not particularly limited thereto. The layer thickness of the base film 6 is not particularly limited, but may be any layer thickness as long as the strength as a package is maintained, and is appropriately selected and designed according to the application.

For example, for the polymer resin, polyethylene, polypropylene, polyvinyl alcohol, polyethylene terephthalate, polyvinyl chloride, polyvinylidene fluoride, polyamide, polyimide, polycarbonate, cellulose which has been unstretched, uniaxially stretched or biaxially stretched as required. ,
It is possible to use general-purpose plastics such as methyl cellulose, methyl ethyl cellulose and carboxymethyl cellulose, and engineering plastics such as polyether tether ketone, polyether sponge, polyether ether imide and polyphenylene sulfide. Further, the surface may be coated with vinylidene chloride (K coat).

Although not shown, the base film 6 is coated with a resin containing various surfactants, color pigments, and fillers, and visible information such as characters and pictures as shown in FIG. It can be optionally provided by a known gravure printing method, offset printing method, or silk screen printing method.

As the adhesive layer 5 for adhering the base film 6 and the metal thin film layer 4, a conventionally known adhesive material used for laminating packaging materials can be used. For example, a two-component curing type urethane adhesive obtained by mixing a main agent composed of an aliphatic or aromatic polyester polyol resin or a polyether polyol resin with a curing agent having one or more isocyanate groups in the skeleton, or one molecule For example, a one-component curable adhesive having both a hydroxyl group and an isocyanate group is used.

The adhesive is not limited to the above,
In addition, polyester resin, polyamide resin, acrylic resin, epoxy resin, vinyl chloride resin, nitrocellulose resin, vinyl acrylate resin, vinyl chloride-vinyl acetate copolymer, chlorinated olefin resin, etc. can be used as an adhesive material. Further, an arbitrary mixture of these can also be used as the adhesive material. Further, it is possible to form a known polyethyleneimine-based, polybutadiene-based or polyurethane-based anchor agent used for extrusion lamination to a thickness of 1 μm or less to form an adhesive layer.

Next, specific examples will be described. (Example 1) A manufacturing apparatus A shown in FIG. 2 uses a vacuum apparatus 9 to form an insulating film on an unstretched polypropylene film having a layer thickness of 60 μm as a long-sized heat-adhesive film 2 supplied from a winding roll 11. As the thin film layer 3, magnesium oxide having a layer thickness of 50 nm is heated by the electron beam method, and the vapor deposition source 14 is heated by the electron beam 13 emitted from the electron gun 12.
It is continuously formed on the metal roll 15 and sent to the next step via the guide roll 16. Next, a silver thin film was formed by the sputtering unit 18 on the metal roll 17 so as to have a layer thickness of 20 nm as the metal thin film layer 4 by using the DC sputtering method, and was wound on the winding roll 19.

The small holes 7 are formed by the vapor deposition apparatus B shown in FIG.
In the plasma discharge part 10 shown in FIG.
Oxygen (80/20 wt%) gas is supplied to generate plasma
Of 0.7 μm continuously on the heat-adhesive film 2.
Small holes 50-70 (pieces / cm ²) Formed.

The vapor-deposited film thus obtained has a printed layer 8 having a design such as a pattern formed on one surface in advance by gravure printing as a base film 6 having a layer thickness of 20 μm.
On the printed surface of the biaxially oriented polypropylene film (OPP), a two-component curable urethane adhesive was applied as the adhesive layer 5, and the metal thin film layer 4 and the base film 6 were dry laminated to form a composite film.

Comparative Example 1 A thin silver film was continuously formed on the heat-adhesive film of Example 1 (unstretched polypropylene having a layer thickness of 60 μm) by a DC sputtering method, and biaxially stretched polypropylene having a layer thickness of 20 μm. Film (OP
P) was laminated by lamination to obtain a composite film.

(Comparative Example 2) On one side of an unstretched polypropylene film having a layer thickness of 60 μm, 10% by weight of silver zeolite was added.
A chlorinated polypropylene resin containing 3 μm was coated by a gravure coating method, and a biaxially oriented polypropylene film (OPP) having a layer thickness of 20 μm used in Example 1 was laminated on the non-coated surface of silver zeolite by lamination to form a composite film. And

(Example 2) As in Example 1, using a vacuum apparatus, aluminum oxide was formed as an insulating thin film layer 3 to a thickness of 30 nm on an unstretched polypropylene film having a layer thickness of 30 μm as a heat adhesive film 2. Then, a silver thin film was formed as the metal thin film layer 4 to have a layer thickness of 40 nm by the DC sputtering method.

(Example 3) As in Example 1, a thermally-adhesive film 2 was formed on a low-density polyethylene film having a layer thickness of 60 μm, and an insulating thin film layer 3 was made of silicon oxide with a layer thickness of 60 nm.
And copper as the metal thin film layer 4 with a layer thickness of 100 n.
formed to m. This copper thin film and a polyethylene terephthalate film having a layer thickness of 60 μm were laminated on one surface with a vapor deposition surface where magnesium oxide was deposited to a layer thickness of 50 nm by laminating with a two-component curing type urethane adhesive to form a composite film.

The antibacterial properties of the antibacterial packaging materials of Examples and Comparative Examples obtained as described above were evaluated by the following method. <Test 1> The antibacterial packaging materials obtained from Examples 1 to 3 and Comparative Examples 1 and ² were cut into 100 cm ² pieces to prepare test pieces. Thermal adhesive film 2 on the non-laminated surface of these test pieces
And the surface coated with silver zeolite of Comparative Example 2 were aseptically washed with 100 ml of sterilized distilled water to which 0.1% of a surfactant (TWEEN80) was added. The number of bacteria in this washing solution was measured by the pour method using ordinary agar medium. The results are shown in Table 1.

[0041]

[Table 1]

<Test 2> Further, each test piece 100 was similarly tested.
cm ² using Staphylococcus aureus
occus aureus) washed cells 100 cm ²
The test pieces were applied so that the number of the test pieces would be 10 ⁵ , and the number of bacteria was measured after the test pieces were left indoors for 24 hours. Hereinafter, the antibacterial properties after one month and one year were measured and evaluated in the same manner. The results are shown in Table 2.

[0043]

[Table 2]

From the test results, those of Examples 1 to 3 show good antibacterial properties at the beginning of the test, after one month and after one year, and the antibacterial effect of the antibacterial packaging material of the present invention is shown. Is effective for a long time. The samples of Comparative Examples 1 and 2 show initial antibacterial properties, but their antibacterial properties decrease over time.

[0045]

As described above, according to the present invention, an insulating thin film layer, a metal thin film layer, an adhesive layer, and
Since it is an antibacterial packaging material in which base films are sequentially laminated and a large number of small holes are formed in the heat-adhesive film and the insulating thin film, the insulating thin film layer and the metal formed on the insulating thin film layer The metal ions released from the thin film layer are adsorbed and stored in a large number of pores formed in the insulating thin film layer, gradually passing through the holes of the base film and eluting or leaching on the surface to the heat-adhesive film. Shows sex.

Since the metal gradually elutes through the small holes of the base film and imparts antibacterial properties to the sheet, the antibacterial layer is further composed of an insulating thin film layer and a metal thin film layer.
Unlike conventional ones in which the metal is exposed from the outermost layer, or those in which an antibacterial agent such as silver zeolite is coated or kneaded into a resin, safety and stable antibacterial property can be maintained for a long time.

Further, the insulating thin film and the metal thin film layer can be formed by an inexpensive dry process, and in particular, the heat-adhesive film and the small holes provided in the insulating thin film can be continuously formed by the vapor deposition process, so that the antibacterial property can be obtained. The packaging material can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the antibacterial packaging material of the present invention.

FIG. 2 is a schematic view illustrating an example of an apparatus for producing an antibacterial packaging material of the present invention.

FIG. 3 is a schematic view of a porous processing apparatus for explaining formation of an insulating thin film layer on a base material film of the antibacterial packaging material of the present invention.

[Explanation of symbols]

1 Antibacterial packaging material 2 Thermal adhesive film 3 Insulating metal layer 4 Metal thin film layer 5 Adhesive layer 6 Base film 7 small holes 8 Printing department A manufacturing equipment B vapor deposition equipment 9, 20 Vacuum device 10, 28 Plasma discharge part 11,25 Unrolling roll 19, 27 Winding roll 12 electron gun 13, 23 electron beam 14,22 evaporation source 15, 17, 21 Metal roll 16,26 Guide roll 18 Sputtering unit 24 arc discharge 29 Supply power 30 Gas for plasma generation

Claims (3)

(57) [Claims] 1. A metal oxide or a metal oxide film on one surface of a heat-adhesive film.
Is an insulating thin film layer made of carbide, an antibacterial metal thin film layer, an adhesive layer, and a base film are sequentially laminated, and a large number of small holes penetrating the heat adhesive film and the insulating thin film layer are formed. An antibacterial packaging material characterized by the following. 2. The antibacterial metal thin film layer is made of silver or copper.
The antibacterial property according to claim 1, which is one of the other
Packaging material. 3. Printing on at least one side of the base film
The layer according to claim 1, wherein the layer is formed.
Item 2. The antibacterial packaging material according to item 2.