JP3368646B2 - Evaporated film laminate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor-deposited film laminate having a vapor-deposited film layer of a metal oxide, and more particularly to a vapor-deposited film laminate having a gas barrier property.

[0002]

2. Description of the Related Art In recent years, packaging materials used for packaging foods, pharmaceuticals, precision electronic parts, etc. suppress deterioration of contents, particularly oxidation and deterioration of proteins and fats and oils in foods, and further improve taste and freshness. In order to hold the product, in pharmaceutical products that require aseptic handling, it suppresses the deterioration of the active ingredient and maintains its efficacy, and in precision electronic components, it also prevents corrosion and poor insulation of metal parts. In order to
It is necessary to prevent the influence of oxygen, water vapor, and other gases that change the contents of the packaging material, and it is required to have a gas barrier property of blocking these gases.

Therefore, a polymer resin composition which is conventionally said to have a relatively high gas barrier property, such as polypropylene (KOP) coated with vinylidene chloride resin, polyethylene terephthalate (KPET) or ethylene vinyl alcohol copolymer (EVOH), has been conventionally used. The packaging film used as a gas barrier material, a metal foil made of a metal such as Al, a suitable polymer resin composition (alone, even a resin that does not have a high gas barrier property)
A packaging film using a metal deposition film obtained by depositing a metal or a metal compound as a packaging material has been generally used.

However, the packaging film using only the above-mentioned polymer resin composition is inferior in gas barrier property as compared with a foil using a metal or a metal compound such as Al or a metal vapor deposition film formed with a vapor deposition film. However, it is susceptible to temperature and humidity, and the gas barrier property may be further deteriorated depending on the change. On the other hand, a foil using a metal or a metal compound such as Al or a metal vapor deposition film on which a vapor deposition film is formed is less affected by temperature and humidity and has excellent gas barrier properties, but the contents of the package can be seen through. It had a drawback that it could not be confirmed.

Therefore, as a packaging material that overcomes these disadvantages, for example, US Pat.
Film formed by forming a metal oxide such as magnesium oxide, silicon oxide or aluminum oxide on a polymer film by a forming means such as a vacuum vapor deposition method or a sputtering method, as described in JP-A-3-28017. Is being developed. This film is known to have transparency and gas barrier properties against oxygen, water vapor, etc., and is suitable as a packaging material having both transparency and gas barrier properties that cannot be obtained with a metal vapor deposition film. .

[0006]

However, even a film suitable for the above-mentioned packaging material is rarely used as a packaging container or a packaging material by itself as a vapor deposition film, and as a post-process after vapor deposition, the vapor deposition film is used. The packaging body is completed through various processes such as printing characters or pictures on the surface or laminating it with another substrate such as a film, and shaping the packaging body such as a container. for that reason,
It is necessary to set the optimum printing conditions for directly coating the printing ink while maintaining the transparency and gas barrier properties peculiar to the vapor-deposited film, and when performing shape processing, for example, to make a bag shape You need to be on the spot.

Therefore, when the printing ink is directly coated on the vapor deposition surface of the vapor deposition film, the shrinkage of the printing ink due to drying is transmitted to the vapor deposition film, causing damage such as cracks and scratches. The ironing in the part causes damage such as cracks and scratches on the deposited film. There is a problem in that a gas such as air and water vapor permeates through the damaged portion, so that the high gas barrier property originally possessed is deteriorated.

That is, as the conditions for use as a package, the transparency is such that the contents themselves can be seen directly, the high gas barrier property for blocking the gas that affects the contents, etc., and the processing into the package. There is a demand for a material having mechanical strength (or flexibility) that does not deteriorate the function against physical and mechanical stress due to the above, and at present, a packaging material satisfying all of these has not been found.

Therefore, the present invention is colorless and transparent, and has a high gas barrier property as well as a mechanical strength that does not deteriorate the gas barrier property against external bending or pulling due to post-processing. An object is to provide a transparent gas barrier material having high properties.

[0010]

The present invention has been made to solve the above problems, and the invention according to claim 1 is characterized in that at least one surface of a substrate made of a polymer material having transparency is thick. A metal oxide thin film layer having a thickness of 300 to 3000 Å and a glass transition point of 60 to 80 ° C. on the metal oxide thin film layer.
And transparent polyester resin, polyurethane resin, and nitro having molecular weight between 10,000 and 20,000
A vapor-deposited film laminate, comprising a transparent primer layer made of any one of cellulose resins and laminated.

The invention described in claim 2 is a vapor-deposited film laminate, wherein the metal oxide thin film layer is magnesium oxide, silicon oxide, or aluminum oxide.

[0012]

[0013]

According to the vapor-deposited film laminate of the present invention, a polymer material having excellent dimensional stability and transparency is provided on a metal oxide thin film layer provided on a substrate made of a polymer material having transparency. The transparent primer layer absorbs and alleviates mechanical stress such as pulling and shrinking when printing ink is dried and ironing of the sailor sack during bag making. It exhibits high light transmittance even after being subjected to various stresses, and can suppress the gas passing through the thin film to be low.

[0014]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view illustrating a vapor deposition film laminate of the present invention.

First, the structure of the vapor deposition film laminate of the present invention will be described with reference to FIG. 1 is a vapor deposition film laminate of the present invention, in which a thin film layer 3 made of a vapor deposition film of a metal oxide is formed on the surface of a substrate 2. The thin film layer 3 may be formed on both sides of the base material 2, or may be formed in multiple layers.

The base material 2 is a polymer material having transparency, and it is particularly preferable that it is colorless and transparent, and normally used as a packaging material. For example, polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films, polyvinyl chloride films,
A polycarbonate film, a polyacrylonitrile film, a polyimide film or the like is used, and the base material 2 may be stretched or unstretched, and has mechanical strength and dimensional stability. Particularly, polyethylene naphthalate arbitrarily stretched in the biaxial direction is used. These are processed into a film and used. Further, a film having excellent smoothness and a small amount of additives is preferable. Further, in order to improve the adhesion of the thin film, the surface of the base material 2 may be subjected to corona treatment, low temperature plasma treatment, ion bombardment treatment as pretreatment, and further subjected to chemical treatment, solvent treatment and the like. May be.

The thickness of the base material 2 is not particularly limited, but considering the suitability as a packaging material, the case where other layers are laminated, and the workability when the thin film layer 3 is formed, In practice, it can be said that the thickness is preferably in the range of 3 to 200 μm, and is preferably 6 to 50 μm depending on the application.

In consideration of mass productivity, it is desirable to use a long film so that a thin film can be continuously formed.

The thin film layer 3 is made of a vapor deposited film of a metal oxide such as magnesium oxide, silicon oxide or aluminum oxide, and may be transparent and have a gas barrier property against oxygen, water vapor and the like. Especially magnesium oxide
It is particularly excellent in transparency and gas barrier property. However, the thin film layer 3 of the present invention is not limited to metal oxides of magnesium oxide, silicon oxide, and aluminum oxide, and any material that meets the above conditions can be used.

The thickness of the thin film layer 3 is generally 3 although optimum conditions vary depending on the type and composition of the metal oxide used.
It is desirable to be in the range of 00 to 3000Å, and the value is appropriately selected. However, if the film thickness is less than 300 Å, the entire surface of the base material 2 may not be a film or the film thickness may not be sufficient, and the function as a gas barrier material may not be sufficiently fulfilled. In addition, the film thickness is 3000Å
This is because if the thickness exceeds the range, the thin film cannot retain flexibility, and cracks may occur in the thin film due to external factors such as bending and pulling after the film formation.

There are various methods for forming the thin film layer 3 made of a metal oxide on the substrate 2. The thin film layer 3 can be formed by an ordinary vacuum deposition method, but other thin film forming methods such as a sputtering method and an ion plating method. The Ting method or the like can be used. However, if productivity is taken into consideration, the vacuum deposition method is currently the best. It is preferable that the heating means of the vacuum vapor deposition apparatus by the vacuum vapor deposition method is an electron beam heating method, and a plasma assist method or an ion beam assist method is used to improve the adhesion between the thin film and the substrate and the denseness of the thin film. Is also possible.

The transparent primer layer 4 is laminated on the thin film layer 3 so that the transparent primer layer absorbs and alleviates mechanical stress such as pulling / shrinking when printing ink is dried and ironing of a sailor's part in bag making. In particular, it is indispensable especially when the metal oxide thin film layer 3 is relatively thin at 500 to 1500Å.

The transparent primer layer 4 is preferably a coating film having low elongation and high hardness. The composition is not particularly limited, but the glass transition point is 60 ° C. or higher and the molecular weight is 10,000.
Composed of a polymeric material having transparency between 20,000 and 20,000.

When the glass transition point is lower than 60 ° C., the coating is not stable at room temperature, so that the coating of the transparent primer layer 4 may be caused by pulling or shrinking due to drying of the printing ink or ironing of the sailor-rolled portion during bag making. A dimensional change occurs, cracks occur in the thin film layer 3, and the gas barrier property deteriorates.
If the glass transition point is 60 ° C. or higher, the above problem does not occur and it is good. However, if the glass transition point is too high, the flexibility of the coating film decreases and the same problem occurs. Therefore, the glass transition point is preferable. The point is preferably 60 to 80 ° C.

If the molecular weight of the resin is less than 10,000, the molecular weight is small, so that the elongation is low, but the coating film becomes brittle and there is a problem in strength. The molecular weight is preferably 15,000 to 1 because the mechanical stress such as ink pulling / shrinking and ironing in a bag-making machine is not sufficiently relaxed.
It is between 8,000.

Examples of the primer resin satisfying the above conditions include polyvinyl chloride type, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral type, polymethylmethacryl type, polyurethane type, polyester type, polyamide type, nitrocellulose type, A thermoplastic polymer resin such as a cellulose derivative-based resin, or a thermosetting polymer resin such as a melamine-based resin or a urea-based resin can be used, and is appropriately selected from these. If necessary, a curing agent or the like may be added and used as a crosslinked product. A polyester resin is particularly preferable because it has excellent dimensional stability, good adhesion to a substrate, and good gravure coating suitability.

The organic solvent that dissolves the primer resin is not particularly limited as long as it can dissolve the resin, and examples thereof include esters such as ethyl acetate and butyl acetate, and ketones such as methyl ethyl ketone and methyl isobutyl ketone. And aromatic hydrocarbons such as toluene and xylene, which are used alone or in any combination. From the viewpoint of coating film processing and odor, a mixture of toluene and methyl ethyl ketone is preferable.

As a method of forming the transparent primer layer 4,
For example, a known printing method such as an offset printing method, a gravure printing method, or a silk screen printing method, or a known coating method such as roll coating, knife edge coating, or gravure coating can be used.

The thickness of the transparent primer layer 4 is not particularly limited as long as a uniform coating film can be formed, but practically, it is preferable that the thickness is 0.2 μm or more. If the thickness is less than 0.2 μm, it is often impossible to form a uniform coating film, and the mechanical stress such as pulling / shrinking of printing ink and ironing in a bag-making machine becomes insufficient, resulting in gas barrier properties. Is likely to decrease. Further, if the thickness exceeds 1.0 μm, there is a problem in terms of odor of the solvent remaining in the primer resin, and the thickness of the transparent primer layer 4 is particularly preferably 0.5 to
The range of 1.0 μm is preferable.

Further, another layer can be laminated on the transparent primer layer 4. For example, a print layer and a heat seal layer. The printing layer is formed for practical use as a packaging body, and various pigments are used in conventionally used ink binder resins such as urethane-based, acrylic-based, nitrocellulose-based, rubber-based, and vinyl chloride-based resins. , A layer composed of an ink to which an extender pigment and a plasticizer, a desiccant, a stabilizer and the like are added, and designs such as letters and pictures are formed. As a forming method, for example, a known printing method such as an offset printing method, a gravure printing method, a silk screen printing method, or a known coating method such as roll coating, knife edge coating, and gravure coating can be used. The thickness may be 0.1 to 2.0 μm.

The heat-sealing layer is used as an adhesive portion when forming a bag-like package, and is made of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene. Resins such as methacrylic acid ester copolymers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers and their metal cross-linked products are used. The thickness is determined depending on the purpose, but is generally in the range of 15 to 200 μm. As a forming method, a known method such as a dry laminating method of laminating a film made of the above resin by a non-solvent laminating method, an extrusion laminating method in which the above resin is melted by heating and extruded in a curtain shape and pasted is laminated. can do.

The vapor deposited film laminate of the present invention will be described with reference to specific examples.

Example 1 As a substrate 2, a polyethylene terephthalate (PET) film having a thickness of 12 μm was vapor-deposited on one surface of a polyethylene oxide terephthalate (PET) film to a thickness of about 500 Å by a vacuum vapor deposition apparatus by an electron beam heating system (not shown). 3 was formed to obtain a magnesium oxide vapor deposition film.
When the vapor deposition film thickness of the obtained vapor deposition film was measured by a fluorescent X-ray analysis method, the thickness was 550 to 600 Å, and the oxygen permeability of this film was measured to be 2.0 to 3.
The value was 0 (cc / m ² / day).

Next, this magnesium oxide vapor deposition film was coated with the following resin primer to form a transparent resin primer layer 4. -Resin: Polyester-Glass transition point: 67 ° C-Molecular weight: 18000-Thickness: 0.70 μm Further, the transparent resin primer layer 4 has urethane-based printing ink
Gravure printing using 4 colors (ink, crimson, yellow, white),
A laminated body was obtained.

[0035]

[Example 2] Outermost layer of the laminate of Example 1(Substrate 2 side)
And polypropylene (CPP) 30μm dry lamine
It was laminated by the hot plate method.

[0036]

Example 3 Example 1ofOutermost layer of laminate(Substrate 2 side)
Extrusion of polyethylene (PE) 15 μm
It was laminated by the laminating method.

[Comparative Example 1] The resin primer of Example 1 was directly applied to the vapor-deposited film without forming the transparent primer layer 4 and directly subjected to gravure printing using four colors of urethane-based printing ink (black, red, yellow and white). A laminated body was obtained.

Example 4 A laminate was obtained in the same manner except that the resin primer of Example 1 was changed to the following constitution. -Resin: Polyester-Glass transition point: 67 ° C-Molecular weight: 18000-Thickness: 0.28 μm

[Comparative Example 2] A laminate was obtained in the same manner except that the resin primer of Example 1 was changed to the following constitution. -Resin: Polyester-Glass transition point: 60 ° C-Molecular weight: 2000-Thickness: 0.75 μm

[Comparative Example 3] A laminate was obtained in the same manner except that the resin primer of Example 1 was changed to the following constitution. -Resin: Polyester-Glass transition point: 7 ° C-Molecular weight: 20000-Thickness: 0.84 μm

Example 5 A laminate was obtained in the same manner as in Example 1 except that the resin primer of Example 1 was changed to the following constitution. -Resin: Polyurethane-Glass transition point: 70 ° C-Molecular weight: 15000-Thickness: 1.03 μm

[Comparative Example 4] A resin primer of Example 1 was changed to the following constitution, and a laminated body was obtained in the same manner except the above. -Resin: Polyurethane-Glass transition point: 47 ° C-Molecular weight: 25000-Thickness: 1.10 μm

Example 6 A laminate was obtained in the same manner as in Example 1 except that the resin primer of Example 1 was changed to the following constitution. -Resin: Nitrocellulose-Glass transition point: 80 ° C-Molecular weight: 20000-Thickness: 0.69 μm

[Embodiment 7] Embodiment 1 in which printing is not performed
Then, 30 μm of polypropylene was laminated on the laminate of No. 1 by a dry laminating method and processed by a bag-making machine.

[Comparative Example 5] Comparative Example 1 without printing
Then, 30 μm of polypropylene was laminated on the laminate of No. 1 by a dry laminating method and processed by a bag-making machine.

[Embodiment 8] As a base material 2, a polyethylene terephthalate (PET) film having a film thickness of 12 μm was deposited on one side by a vacuum vapor deposition apparatus by an electron beam heating system (not shown) to a thickness of about 400 Å to form a thin film layer. 3 was formed to obtain a silicon oxide vapor deposition film. When the oxygen transmission rate of the obtained vapor deposition film was measured, it was 2.0 to 3.0 (c
The value of c / m ² / day) is shown.

Next, this silicon oxide vapor deposition film was coated with the following resin primer by a gravure coating method to form a transparent resin primer layer 4. -Resin: Polyester-Glass transition point: 67 ° C-Molecular weight: 18000-Thickness: 0.70 μm

Further, the outermost layer of this laminate(Substrate 2 side)
And polypropylene (CPP) 30μm dry lamine
The sheets were laminated by a sheet method and processed by a bag-making machine.

[Comparative Example 6] The resin primer of Example 8 was changed to the following constitution, and otherwise laminated, and processed by a bag-making machine. -Resin: Polyester-Glass transition point: 7 ° C-Molecular weight: 20000-Thickness: 0.80 μm

[Comparative Example 7] The vapor-deposited film of Example 8 was prepared without forming the transparent primer layer 4 and was made of polypropylene 30 μm.
Were laminated by a dry laminating method and processed by a bag making machine.

Oxygen permeability (cc / m ² /) before and after forming the print layer of each laminate, after laminating the heat seal layer, and after bag making.
Table 1 shows the results of measurement and evaluation of (day).

[0052]

[Table 1]

In contrast to the examples, the comparative examples are provided with the above-mentioned conditions for use as a package, and are transparent enough to allow the contents themselves to be directly looked at, and a gas that affects the contents is blocked. It cannot be said that it does not satisfy all the high gas barrier properties and the mechanical strength (or flexibility) that does not deteriorate the function against physical and mechanical stress due to processing into a package.

[0054]

As described above, according to the present invention, the transparency and gas barrier property after film formation are excellent, and in the post-processing step, shrinkage of printing ink and external bending and pulling by a bag-making machine are performed. It does not cause damage such as film cracking on the thin film against the action of ironing, etc., and has the transparency, gas barrier property, mechanical strength, and flexibility that are the conditions used as the above-mentioned package. As a result, it is possible to obtain a laminate that can maintain the transparency and gas barrier properties of the metal oxide thin film and can sufficiently exhibit practical use.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a vapor deposition film laminate of the present invention.

[Explanation of symbols]

1 Vapor deposition film laminate 2 base materials 3 thin film layers 4 Transparent resin primer layer

Continuation of the front page (56) Reference JP 5-8318 (JP, A) JP 3-239599 (JP, A) JP 5-177992 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (2)

(57) [Claims] 1. A metal oxide thin film layer having a thickness of 300 to 3000 Å is provided on at least one surface of a substrate made of a polymer material having transparency, and a glass transition point of 60 to 80 is provided on the metal oxide thin film layer. ℃ and molecular weight 10,000 to 20,000
Polyester resin with transparency between
A vapor-deposited film laminate, comprising a transparent primer layer made of a polymer material selected from the group consisting of a tan resin and a nitrocellulose resin . 2. The vapor-deposited film laminate according to claim 1, wherein the metal oxide thin film layer is made of magnesium oxide, silicon oxide or aluminum oxide.