JP3534800B2 - Evaporated film and its package - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a vapor-deposited film, and more particularly to ethylene-α polymerized using a single-site catalyst.
The present invention relates to a vapor-deposited film obtained by forming a metal or metal oxide thin film on an olefin copolymer film.

[0002]

2. Description of the Related Art Heretofore, a vapor deposition film obtained by vapor-depositing a metal or a metal oxide on a plastic film is known in order to impart a gas barrier property against water vapor and oxygen, a light shielding property, a conductivity and the like.

As a base film for such a vapor-deposited film, polyester, nylon, polypropylene, polyphenylene ether, polysulfide,
Polycarbonate, polyethylene, etc. are used.
Especially for polyethylene films, high-pressure polyethylene is used.

[0004]

However, high-pressure polyethylene is inferior in physical properties and heat-sealing strength, so that a good vapor-deposited film cannot be obtained.

Further, linear low density polyethylene (LLDP
Although it is possible to use E) as a base film of a vapor-deposited film, LLDPE has better physical properties and heat seal strength than high-pressure polyethylene, but is added to improve the low molecular weight component contained in the film and the slip of the film. Due to the influence of the additive, the adhesion between the film and the vapor-deposited film is poor, and a good vapor-deposited film has not yet been obtained.

As described above, a vapor-deposited film which is excellent in low-temperature sealability and heat-sealing strength, has good adhesion between the film and the vapor-deposited film, and has good slippage has not yet been obtained and has not been put into practical use.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a vapor-deposited film which is excellent in low-temperature sealability and heat-sealing strength, has good adhesion between the film and the vapor-deposited film, and has good slipperiness.

[0008]

In order to achieve the above object, the vapor-deposited film of the present invention comprises an ethylene-α-olefin copolymer film polymerized using a single site catalyst and a thin film of metal or metal oxide. The structure is formed.

In the vapor-deposited film of the present invention, if necessary, the metal or metal oxide may be aluminum, silicon oxide, aluminum oxide, indium oxide,
Any one selected from tin oxide, the metal or metal oxide thin film is a thin film formed by any one of a vacuum deposition method, a sputtering method, and an ion plating method. The vapor deposition surface is subjected to one or more of corona treatment, flame treatment, plasma treatment, and UV treatment.

Furthermore, the packaging body of the present invention has a structure in which the vapor deposition film of the present invention or a laminate containing the vapor deposition film is used to form a packaging body.

[0011]

The vapor-deposited film of the present invention has a structure in which a thin film of a metal or a metal oxide is formed on an ethylene-α-olefin copolymer film polymerized by using a single-site catalyst. The ethylene-α-olefin copolymer polymerized by the method has a narrow molecular weight distribution and has a very low content of low molecular weight substances, so that it has good lubricity and is easy to process even if a lubricant is not added. Since the content of is very small and it is not necessary to add a lubricant, a vapor-deposited film having sufficient adhesion strength can be obtained even when vapor-deposited directly on the film.

Further, the ethylene-α-olefin copolymer film polymerized using a single-site catalyst has a narrow molecular weight distribution and good transparency, so that a clean vapor-deposited film can be obtained, and it has good cold shock resistance. It can also be suitably used as a packaging film for foods and the like.

Further, since the melting point of the ethylene-α-olefin copolymer polymerized using a single-site catalyst can be controlled by the amount of comonomer, a vapor-deposited film excellent in low temperature sealing property and heat sealing strength can be obtained. That is, as the amount of comonomer increases, the melting point decreases,
A vapor-deposited film having a low temperature sealing property is obtained.

Further, the package formed by using the vapor-deposited film of the present invention is excellent in low-temperature sealing property and heat-sealing strength, so that a sealing layer for sealing the vapor-deposited film is unnecessary, and therefore, it is used for the package. It is possible to simplify the layer structure of the laminate. Further, since the heat sealing strength is strong, a laminated film having a strong laminating strength can be obtained.

The vapor deposited film of the present invention will be described in detail below. The vapor deposition film of the present invention has a constitution in which an ethylene-α-olefin copolymer film polymerized by using a single site catalyst (SSC) is used as a base film of the vapor deposition film.

Here, the single-site catalyst (including a metallocene catalyst, a so-called Kaminsky catalyst) is characterized in that the active sites are uniform (single site). This single-site catalyst is a catalyst composed of a metallocene-based transition metal compound and an organic aluminum compound, and may be used by being supported on an inorganic substance.

Examples of the metallocene-based transition metal compound include transition metals selected from the IVB group [titanium (Ti), zirconium (Zr), hafnium (H).
f)] is a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a tetrahydroindenyl group, a substituted tetrahydroindenyl group,
A fluorenyl group or a substituted fluorenyl group has 1 to 2 bonds, or two of these groups are linked by a covalent bond to form a bond, and also a hydrogen atom, an oxygen atom, a halogen atom, an alkyl group. , Those having a ligand such as an alkoxy group, an aryl group, an acetylacetonate group, a carbonyl group, a nitrogen molecule, an oxygen molecule, a Lewis base, a substituent containing a silicon atom, and an unsaturated hydrocarbon.

Further, as the organoaluminum compound,
Examples thereof include alkyl aluminum, chain-like or cyclic aluminoxane, and the like. Here, as the alkylaluminum, triethylaluminum, triisobutylaluminum, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, dimethylaluminium fluoride, diisobutylaluminum hydride, diethylaluminum hydride, ethylaluminum sesquichloride and the like can be mentioned. Can be mentioned.

The chain or cyclic aluminoxane is produced by bringing alkylaluminum into contact with water. For example, it can be obtained by adding alkylaluminum at the time of polymerization and then adding water, or by reacting water of crystallization of a complex salt or adsorbed water of an organic / inorganic compound with alkylaluminum.

Examples of the inorganic material carrying the above single-site catalyst include silica gel, zeolite, diatomaceous earth and the like. Examples of the polymerization method include bulk polymerization, solution polymerization, suspension polymerization, gas phase polymerization, and the like, and the polymerization may be a batch method or a continuous method.

The polymerization conditions are usually a polymerization temperature of -100 to
The temperature is 250 ° C., the polymerization time is 5 minutes to 10 hours, and the reaction pressure is normal pressure to 300 kg / cm ² . As the α-olefin which is a comonomer copolymerized with ethylene, propylene,
1-butene, 3-methyl-1-butene, 4-methyl-1
-Pentene, 1-hexene, 1-octene, decene and the like. These α-olefins may be used alone or in combination of two or more.

The mixing ratio of α-olefin is preferably 1 to 50 mol%. The ethylene-α-olefin copolymer may be added with an antioxidant, an ultraviolet absorber, an antistatic agent, an antiblocking agent, a flame retardant, an inorganic or organic filler, a dye, a pigment, or the like as appropriate. Good.

The physical properties of the ethylene-α-olefin copolymer polymerized using the above single-site catalyst are, for example, a molecular weight of 5 × 10 ^{3 to} 5 × 10 ⁶ , and a density of 0.89 to 0.
95 (g / cm ³ ), melt index [MI]
It is 0.1 to 50.

Further, the obtained resin has a low comonomer content and a small amount of low-molecular-weight substances having a uniform copolymerization ratio of ethylene and α-olefin in any molecule and a large comonomer content, as compared with linear low-density polyethylene (LLDPE). Less high molecular weight.

The method of forming the film is not particularly limited, but examples thereof include a T-die method and an inflation method. These films are appropriately stretched before use. Further, these films are laminated with other films by dry lamination, sand lamination, or the like.

The thickness of the film is usually 5 to 200 μm.
It is considered as a degree. As shown in FIG. 1, the vapor-deposited film 1 of the present invention has a structure in which a thin film 3 of metal or metal oxide is formed on an ethylene-α-olefin copolymer film 2 polymerized by using the above-mentioned single site catalyst. There is. The thin film 3 of metal or metal oxide is not limited to being formed on one surface of the film 2, and naturally includes the case of being formed on both surfaces of the film 2.

Here, as the thin film of metal or metal oxide, aluminum, silicon oxide, aluminum oxide,
Examples thereof include indium oxide and tin oxide. Examples of the method for forming a metal or metal oxide thin film include a vacuum vapor deposition method, a sputtering method, an ion plating method, and the like. In the present invention, a film on which a metal or metal oxide thin film is formed is called a vapor deposition film, but the metal or metal oxide thin film is not limited to a vacuum vapor deposition film.

In the vacuum vapor deposition method, the vapor deposition material is 10 ⁻⁴ to
Under the pressure of 10 ^-6 Torr (high vacuum), the electron beam (E
B), heating by a method of high frequency, resistance, high frequency electromagnetic induction or the like to vaporize and deposit on the vapor deposition surface of the film. The thickness of the deposited film is usually about 100 to 1000 angstrom.

As the sputtering method, there are methods such as bipolar sputtering, magnetron sputtering, high frequency sputtering, and reactive sputtering, which are usually 10 ^-2 to 10 ^-4 T.
Sputtering is performed under the pressure of orr.

The ion plating method is usually 1 to 1
The plasma formation method is performed under the pressure of 0 ^-2 Torr.
There are direct current method and high frequency method. Before forming a metal or metal oxide thin film on an ethylene-α-olefin copolymer film polymerized using a single-site catalyst, a corona treatment, a flame treatment, a plasma treatment, a UV treatment is performed on the vapor-deposited surface of the film. You may perform one or more processes of a process etc.

Further, a primer layer may be formed on the vapor-deposited surface of the film before forming the metal or metal oxide thin film on the ethylene-α-olefin copolymer film polymerized using a single-site catalyst. . The primer layer is, for example, a urethane resin, an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, a polyester resin, or the like, on the deposition surface of the film, by various coating methods,
It is formed by coating with a thickness of about 0.01 to 1 g / m ² .

Next, the package of the present invention will be described.
The package of the present invention has a structure in which the above-described vapor-deposited film of the present invention or a laminate containing the vapor-deposited film is used to form a package.

The laminate containing the vapor-deposited film of the present invention described above may have various embodiments. For example, a stretched polypropylene (OPP) film (outermost layer) / ethylene-methacrylic acid copolymer / single-site catalyst may be used. A laminated body including a vapor-deposited film (innermost layer) of the ethylene-α-olefin copolymer obtained by using it can be mentioned.

Here, it is appropriate that the outermost OPP film has a thickness of about 10 to 30 μm. Further, the surface of the OPP film is preferably subjected to corona treatment in order to impart printability. The appropriate thickness of the ethylene-methacrylic acid copolymer is about 10 to 30 μm. The thickness of the ethylene-α-olefin copolymer film obtained by using the single site catalyst is appropriately about 15 to 50 μm. Ethylene-α obtained using a single-site catalyst
Examples of the method for laminating the olefin copolymer film include a T-die method, a method in which a film formed by an inflation method is subjected to sand lamination, a method in which dry lamination is performed using a urethane adhesive, and the like.

When the vapor-deposited film of ethylene-α-olefin copolymer polymerized using a single-site catalyst is used as the innermost layer of the package, the ethylene-α-olefin copolymer polymerized using this single-site catalyst is ,
Since the molecular weight distribution is narrow and the content of low-molecular weight substances is very small, no odor is transferred to the contents, and therefore a sensory good package can be obtained.

The package formed by using the above vapor-deposited film of the present invention does not require a sealing layer for sealing the vapor-deposited film because the vapor-deposited film has excellent low-temperature sealing property and heat-sealing strength. It is possible to simplify the layer structure of the laminate used for. This layer structure can be simplified by, for example, conventional stretched polyester (O-PE).
T) film (outermost layer) / polyethylene / deposited O-PET
This is clear when compared with a laminate composed of film / polyethylene / unstretched polypropylene film (CPP) (innermost layer).

When compared with the conventional O-PET film / vapor-deposited unstretched polypropylene film (CPP),
The conventional vapor-deposited PP film has a problem that it lacks cold shock resistance, but the vapor-deposited film of the present invention is excellent in cold shock resistance, and thus is suitable for use as a package for frozen foods and the like.

Further, since the vapor-deposited film of the present invention has a high heat-sealing strength, a laminated film having a strong laminating strength and a package thereof can be obtained. The packaging body (bag and paper container) of the present invention formed by using the above-mentioned laminated body including the vapor-deposited film of the present invention is made into various forms of packaging by various conventionally known methods.

For example, in the case of a paper container, it can be assembled into various shapes such as a Gobel top type, a flat top type, a box type and the like. Further, in the case of the bag body, for example, the shape is a three-way seal, a four-way seal, a vertical pillow, a horizontal pillow, or the like.

Other embodiments of the laminate containing the vapor deposited film of the present invention include, for example, laminates of various conventionally known films for laminates and the vapor deposited film of the present invention. Of course, the vapor deposition film of the present invention or a laminate containing the vapor deposition film may be laminated with a paper layer.

The use of the vapor-deposited film of the present invention and the package thereof is not particularly limited. For example, confectionery (snack, rice cake, chocolate, candy, etc.), beverage (liquor,
Shochu, wine, juice, milk, etc.), seasonings (soy sauce, mirin, dressing, noodle soup, etc.), pharmaceuticals, industrial materials, daily necessities, chemical products (detergents, oils, waxes, paints, adhesives, etc.) Vapor-deposited film and its package (bag and paper container)
Is preferably used as. Moreover, the vapor-deposited film of the present invention and the laminate containing the vapor-deposited film are also used for applications such as a laminate tube, an infusion bag, a lid material for a container, and a label.

[0042]

EXAMPLES The present invention will be described in more detail based on the following examples. Example 1 Single-site catalyst (Kaminsky catalyst: zirconocene dichloride and methylalumoxane (molar ratio 1: 1250)
Ethylene-1-hexene copolymer (d: 0.920 g / cm ³ , [MI]:
4) was formed into a film having a thickness of 60 μm by the T-die method,
One side of this film was corona treated. Next, on the corona-treated film surface, aluminum was vapor-deposited in a thickness of 300 Å by a vacuum vapor deposition method to obtain a vapor-deposited film. Example 2 Ethylene-1-hexene copolymer polymerized using Kaminsky catalyst (d: 0.925 g / cm ³ , [MI]:
1) was formed into a film having a thickness of 60 μm by the inflation method. Then, one side of this film is subjected to corona treatment, and then 300 aluminum is vacuum deposited.
Vapor-deposited film was obtained by vapor-depositing to a thickness of angstrom. Example 3 A vapor-deposited film was obtained in the same manner as in Example 2 except that silicon oxide was vapor-deposited at a thickness of 400 Å instead of vapor-depositing aluminum. Comparative Example 1 Ethylene-1-hexene copolymer polymerized using a Ziegler-based catalyst (d: 0.925 g / cm ³ , [MI]:
1) was formed into a film having a thickness of 60 μm by the inflation method. Next, corona treatment is applied to one side of this film, and then aluminum is applied to the surface by vacuum deposition to remove aluminum.
A vapor deposition film was obtained by vapor deposition with a thickness of 0 angstrom. Performance Evaluation The vapor deposition surface of the vapor deposition film obtained in Examples 1 and 2 and Comparative Example 1 and a biaxially stretched polyester film having a thickness of 12 μm were dry laminated with a urethane two-component curing adhesive. The peel strength and the O ₂ barrier property of the obtained laminated film were evaluated. The results are shown in Table 1.

[0043]

[Table 1] As is apparent from Table 1, the laminates (Examples 1 to 3) containing the vapor deposition film of the present invention have a higher laminate strength and O ₂ than the laminates containing the conventional vapor deposition film (Comparative Example 1).
It can be seen that it has excellent barrier properties.

[0044]

As described above in detail, the vapor-deposited film of the present invention is formed by forming a thin film of metal or metal oxide on an ethylene-α-olefin copolymer film polymerized by using a single site catalyst. The ethylene-α-olefin copolymer polymerized using this single-site catalyst has a narrow molecular weight distribution and has a very low content of low-molecular weight substances, so it has good lubricity even if a lubricant is not added and is processed. A vapor-deposited film that is easy to obtain is obtained, and since the content of low molecular weight substances is very small and it is not necessary to add a lubricant,
Even if the film is directly vapor-deposited, a vapor-deposited film having sufficient adhesion strength can be obtained.

Further, the ethylene-α-olefin copolymer film polymerized using a single-site catalyst has a narrow molecular weight distribution and good transparency, so that a clean vapor-deposited film can be obtained, and this film also has good cold shock resistance. Therefore, it can be suitably used as a packaging film for frozen foods and the like.

Further, the melting point of the ethylene-α-olefin copolymer polymerized by using a single-site catalyst can be controlled by the amount of comonomer, so that a vapor-deposited film excellent in low temperature sealing property and heat sealing strength can be obtained.

Furthermore, since the package formed by using the vapor deposition film of the present invention is excellent in low-temperature sealing property and heat sealing strength, a sealing layer for sealing the vapor deposition film is unnecessary, and therefore, it is used for the package. It is possible to simplify the layer structure of various laminated bodies. Further, since the heat sealing strength is strong, a laminated film having a strong laminating strength can be obtained.

Further, since the vapor-deposited film of the present invention is excellent in low-temperature heat-sealing property, it has good suitability for filling machine and, therefore, the production of various packages is very easy.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an example of a vapor deposition film of the present invention.

[Explanation of symbols]

1 ... Vapor-deposited film 2 ... Ethylene-α obtained using single-site catalyst
Olefin copolymer film 3 ... Metal or metal oxide thin film

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B65D 65/42 B65D 65/42 C 75/00 75/00 C08J 7/00 CES C08J 7/00 CES // C23C 14/10 C23C 14/10 14/14 14/14 B C08L 23:00 C08L 23:00

Claims (5)

(57) [Claims] 1. A vapor-deposited film comprising a thin film of a metal or a metal oxide formed on an ethylene-α-olefin copolymer film polymerized by using a single-site catalyst. 2. The metal or metal oxide is aluminum, silicon oxide, aluminum oxide, indium oxide,
The vapor deposited film according to claim 1, which is any one selected from tin oxide. 3. The vapor deposition according to claim 1, wherein the metal or metal oxide thin film is a thin film formed by any one of a vacuum vapor deposition method, a sputtering method and an ion plating method. the film. 4. The vapor-deposited film according to claim 1, wherein the vapor-deposited surface of the film is subjected to one or more treatments of corona treatment, flame treatment, plasma treatment and UV treatment. 5. A package formed by using the vapor deposition film according to claim 1 or a laminate including the vapor deposition film.