JP3067501B2 - Gas barrier 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 gas barrier laminate for packaging materials having good barrier properties against oxygen and water vapor.

[0002]

2. Description of the Related Art Conventionally, as a gas barrier synthetic resin film, there are a polyvinyl alcohol film, a polyacrylonitrile film, an ethylene / vinyl alcohol copolymer resin film, etc. for oxygen, and a polypropylene film, Although there are polyethylene films, etc., these synthetic resin films alone do not have the barrier properties of both oxygen and water vapor, so other types of films with different characteristics are laminated together, making use of the characteristics of each. It was used as a packaging film for laminated films. However, these laminated films are affected by temperature and humidity in a storage or use environment, and may not exhibit sufficient barrier performance. On the other hand, as a synthetic resin film having a barrier property to both oxygen and water vapor, a polyvinylidene chloride film, a polyester film, a polypropylene film, a nylon film and the like are coated films coated with polyvinylidene chloride. However, there is an environmental problem because toxic gas is generated during incineration after use. Conventionally, in the case of a packaging material requiring a high barrier property, a material obtained by bonding an aluminum foil to a synthetic resin film has been used. However, packaging materials using such metal foils have excellent barrier properties against oxygen and water vapor,
As waste after use, residual residue remains during incineration,
Reuse is also difficult, and there is an unfavorable aspect in environmental hygiene. In order to solve the problem of environmental hygiene, a synthetic resin film having a metal or metal oxide such as aluminum, aluminum oxide or silicon oxide deposited on the surface thereof has been used.

[0003]

However, since the above-described thin film on which a metal or metal oxide is deposited is an inorganic compound while the synthetic resin film as the base material is an organic compound,
Their mechanical, chemical and thermal properties are very different. A vapor deposited film is a combination of different properties. For this reason, when mechanical or thermal stress is applied to the deposited film, the deposited film may be distorted due to the difference in strength, causing cracks or pinholes, or the chemical bonding state may be different. From, the deposited thin film causes delamination from the base film, and furthermore, due to the contents, causes distortion or poor adhesion to the deposited thin film,
In some cases, the barrier performance of the deposited film was significantly impaired.

For this reason, many attempts have been made to improve the adhesion between the synthetic resin film as the base material and the deposited thin film. For example, a method has been used in which a surface of a polyester film is subjected to a corona discharge treatment, an ultraviolet irradiation treatment, a plasma treatment or a flame treatment to activate the surface, and then a metal or a metal oxide is deposited. However, these methods of activating the surface of the film can be expected to improve the adhesiveness by increasing the secondary bonding force due to the wetting of the deposited thin film, but the activity ability decreases with time, or the adhesion is not necessarily satisfactory. It wasn't enough because I didn't have enough power.

Other methods for improving the adhesion between the polyester film and the vapor-deposited thin film of metal or metal oxide include a surface treatment method using a chemical such as an acid or an alkali, a polyester film and other components such as an acid component, There are copolymerized polyester films copolymerized with glycol components and the like, or co-extruded multilayer polyester films obtained by co-extrusion of other resins at the time of forming the polyester film, but none of them have obtained sufficiently satisfactory adhesion. .

Further, an ethyleneimine-based compound may be formed on the surface of a synthetic resin film as a base material in an off-line or in-line manner.
Although there is a method of applying an anchor coating agent such as an amine type, an epoxy type, a urethane type or a polyester type, the coated surface has improved adhesion with a metal or metal oxide deposited thin film, but the barrier property has an anchor. This was lower than that of a vapor-deposited synthetic resin film not coated with a coating agent. This is because the thermal dimensional stability of the anchor coating layer is poor, so that the vapor-deposited thin film receives mechanical stress during the thermal load of the vapor-deposited polyester film. This is because the property is reduced.

The present invention improves the adhesion between the above-mentioned synthetic resin film substrate and the vapor-deposited thin film, and solves the problem that the barrier property is impaired due to cracks or pinholes in the vapor-deposited thin film. An object of the present invention is to provide a gas barrier laminate used as a packaging material having good barrier properties against water vapor and the like.

[0008]

According to the first invention, as shown in FIG. 1, at least one surface of a synthetic resin film (110) has a chemical formula of R-Si- (OR ') ₃ (R is an organic functional film). Group, OR ′ is a hydrolyzable group), and forms an organosilicon compound layer (120) represented by the following formula: Metal compound vapor deposited thin film layer (1
30) A gas barrier laminate (100) formed by forming (30).

In a second aspect, the organic functional group (R) of the organosilicon compound layer according to the first aspect is -CH = CH.
_{2, -CH 2 -CH 2 -CH 2} -NH 2, -CH 2 -N
_{H 2, -CH 2 -NHCONH 2,} -CH 2 -NH-C
H ₂ —CH ₂ —NH ₂ , — (C ₂ H ₂ O) —, —CH ₂
—O—CH ₂ — (C ₃ H ₃ O) and a hydrolyzable group (O
R ') _{is, -OCH 3, -OCH 2 -CH 3} , -OCH
A gas barrier laminate, which is a ₂ -O-CH _3.

According to a third aspect of the present invention, as shown in FIG. 2, a metal or metal compound vapor-deposited thin film layer surface (130) according to the first or second aspect of the invention is interposed through an adhesive layer (140). A gas barrier laminate (200) comprising a heat-adhesive resin layer (150).

The above-mentioned synthetic resin films include polyolefin films such as polyethylene and polypropylene, polyethylene terephthalate and polyethylene-2,
Polyester films such as 4-naphthalate, polyamide films such as nylon 6 and nylon 12, polyvinyl alcohol films, aromatic polyamide films,
Polyamide imide film, polyether imide film, polysulfone film, polyether sulfone film, polyether ether ketone, polyarylate film, polyphenylene sulfide film, polyphenylene oxide film, tetrafluoroethylene film, fluorinated ethylene propylene copolymer film, etc. No. If necessary, these biaxially stretched synthetic resin films are used. Incidentally, these synthetic resin films may be added with usual additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant and a coloring agent, and the surface on which the organosilicon compound is formed may be added. A surface activation treatment such as a corona discharge treatment, a plasma treatment, a glow discharge treatment, a reverse sputtering treatment, or a roughening treatment may be performed. The thickness of these synthetic resin films is not particularly limited, but is preferably in the range of 2 to 400 μm in consideration of workability in the vapor deposition step.

The method of forming the organosilicon compound layer can be performed by applying an in-line method during the production of the synthetic resin film or by applying an off-line method in a separate step from the production of the synthetic resin film. May be. And the organosilicon compound in the present invention is R-Si- (O
R ') ₃ (R is an organic functional group, OR' is a hydrolyzable group)
Organic functional group (R)
_{Is, -CH = CH 2, -CH 2} -CH 2 -CH 2 -NH
_{2, -CH 2 -NH 2, -CH} 2 -NHCONH 2, -
CH ₂ —NH—CH ₂ —CH ₂ —NH ₂ , — (C ₂ H _{2
O) -, - CH 2 -O} -CH 2 - (C 3 H 3 O) and the like, an epoxy group, an amino group, urea group are preferable,
Further, the hydrolyzable group (OR ') is, -OCH _3, -OC
H ₂ —CH ₃ and —OCH ₂ —O—CH ₃ . The thickness of the organosilicon compound layer is not particularly limited. However, considering workability and thermal dimensional stability, the thickness is 0.05%.
10 to 10 μm, preferably 0.1 to 3 μm
It is.

As a method for plasma-activating the surface on which the vapor-deposited thin film of the organosilicon compound layer is to be formed, a glow discharge treatment, a high-frequency plasma treatment, a microwave plasma treatment or the like can be used. As the gas to be used, there is no limitation as long as an oxygen-containing mixed gas is used and the mixing ratio of oxygen is in the range of 1 to 100%. The gas to be mixed with oxygen is not particularly limited as long as it is a stable gas such as nitrogen, argon, or carbon dioxide. In addition, the pressure of the processing part of the plasma processing is 8 × 10 ^-5 to 8 × 10 ^-1 Torr.
And preferably 8 × 10 ⁻⁴ to 8 × 10 ⁻³ torr. The plasma processing energy applied to the processing surface may be in the range of 1 to 50,000 joules, but is preferably in the range of 10 to 10,000 joules. This is because the treated surface is not sufficiently activated at 1 joule or less, and at 50,000 joules or more, the molecules on the treated surface are destroyed and a vapor deposited thin film having a uniform thickness cannot be obtained.

Method for forming a thin film of the metal or metal compound of the present invention
Methods include vacuum deposition, ion plating, and sputtering.
Can be used, such as vacuum evaporation or ion implantation.
Ratings are preferred. The heating method is
Heat, EB heating, high frequency induction heating, etc. can be used
You. The deposition materials are aluminum (Al), silicon (S
i), titanium (Ti), zinc (Zn), zirconium
(Zr), magnesium (Mg), tin (Sn), copper
Metals such as (Cu) and iron (Fe)
Oxides, nitrides, sulfides, fluorides, etc.
Aluminum (Al_TwoO _Three), Silicon oxide (SiO),
Titanium oxide (TiO_Two), Zirconium oxide (Zr
O_Two), Magnesium oxide (MgO), tin oxide (Sn
O_Two), Zinc sulfide (ZnS), magnesium fluoride (M
gF_Two) Can be used. And before vapor deposition
The degree of vacuum in the vapor deposition device is 2 × 10^-6~ 8 × 10^-3Thor
(Torr), but preferably 8 × 10^-6
~ 8 × 10^-FiveVacuum down to Torr and then deposit
Do. In addition, deposited metal or metal compound deposited thin film
The layer has a barrier property against oxygen, water vapor, etc.
However, the barrier characteristics depend on the material and film thickness of the formed material.
It depends on the situation. In particular, metallic aluminum, silicon oxide
Barrier film with good vapor deposition thin film of silicon or aluminum oxide
Shows sex. Thickness of the deposited thin film layer of this metal or metal compound
May be in the range of 50-5,000 °, preferably
The range of 300 to 1,500 ° is good. This means that the thickness is 5
In the case of 0 ° or less, it is difficult to control a uniform
Easy to vary, and more than 5,000mm
In the case of, cracks and pinholes are likely to occur in the deposited thin film layer
This is because barrier properties are impaired. Evaporation formed
The thin film layer is not limited to a single layer of a single component,
It may be a layer or a multilayer vapor-deposited thin film layer.

The heat-adhesive resin layer according to the present invention is a synthetic resin layer which is easily heat-sealed by heating and pressing. Examples of the synthetic resin include polyolefins such as polyethylene, polypropylene and ethylene-propylene copolymer, polyesters, and the like.
Polyamides, ionomers, ethylene-vinyl acetate copolymers, acrylic resins such as acrylates and methacrylates, polyvinyl acetal, phenolic resins, modified epoxy resins and copolymers and mixtures thereof, but not necessarily these However, the present invention is not limited to this. Among these resins, polyolefin, polyester, polyamide, ethylene-vinyl acetate copolymer and the like are preferable. The thickness of the heat-adhesive resin layer varies depending on the application, but is in the range of 1 to 200 μm, preferably 10 to 100 μm. The laminating method for forming the heat-adhesive resin layer may be a general laminating method such as a dry laminating method, a solventless laminating method or an extrusion laminating method. The heat-sealing temperature of the heat-adhesive resin layer is 200 ° C. or less in consideration of the heat resistance of the alkoxide coating layer, and is 80 to 80 ° C.
180 ° C. is preferred.

[0016]

The organic silicon compound layer formed on the synthetic resin film in the present invention has a strong adhesive force with the synthetic resin of the synthetic resin film because the organic functional group of the organic silicon compound has a strong bonding force with the synthetic resin of the synthetic resin film. Is high, and the hydrolyzable group of the organosilicon compound is hydrolyzed to a hydroxyl group (−
OH) to form an active Si—OH bond with the metal element (M), and this hydroxyl group is —O—M—O—
To form a strong bond between the organic silicon compound layer and the metal or metal compound vapor-deposited thin film formed by vapor deposition on the organic silicon compound layer.

The metal element (M) formed on the surface of the organosilicon compound layer and the active Si—OH bond may be insufficient depending on the coating conditions. When the surface of the organosilicon compound layer is subjected to plasma activation treatment, Si-OH bonds are uniformly formed on the surface of the organosilicon compound layer, so that the adhesion between the deposited thin film of the metal or the metal compound and the organosilicon compound layer is stabilized. .

[0018]

【Example】

Example 1 First, an aqueous solution of N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane (organosilicon compound) having a solid content of 2 wt% was placed on one surface of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm. Was applied by a gravure coating method and dried to produce a biaxially stretched polyethylene terephthalate film having an organosilicon compound layer formed on one surface. The winding speed is 40
m / min, the drying condition is 90-100 ° C, and the coating amount is
It was 0.15 g / m ² .

Next, the prepared biaxially stretched polyethylene terephthalate film having an organosilicon compound layer formed on one side was loaded into a roll-up EB heating vacuum apparatus, and the degree of vacuum was set to 1.5 × 10 ^-5 torr. Thereafter, an oxygen plasma treatment was performed, and silicon oxide was deposited on the treated surface to produce a gas barrier laminate according to the present example. The oxygen plasma processing conditions at that time were as follows: 99.9% oxygen used, a flow rate of 600 sccm, a plasma processing method of glow discharge processing, a supply power of 250 W, a winding speed of 1.5 m / sec, and a pressure of 5 × 10 ^{−. 3} mbar, and the silicon oxide deposition conditions were that the deposition material was 99.9% silicon oxide, EB-Powe
r was 30 kV-0.5 A, the deposited film thickness was 1,000 °, and the pressure was 2 × 10 ⁻³ mbar.

Further, a 30 μm-thick unstretched polypropylene film (heat-adhesive resin) was adhered to the silicon oxide-deposited thin film surface of the gas barrier laminate thus produced by a dry laminating method. A laminate was produced.

<Example 2> The gas barrier properties of Example 2 prepared in the same manner as in Example 1 except that an aqueous solution of γ-aminopropyltriethoxysilane having a solid content of 2 wt% was used as the aqueous solution of the organosilicon compound. A laminate was produced.

Example 3 A gas barrier laminate of Example 3 was prepared in the same manner as in Example 1, except that the deposition material was aluminum oxide and the EB-Power was 30 kV-0.75 A. .

Example 4 A gas barrier laminate of Example 4 was produced in the same manner as in Example 1 except that the deposition material was magnesium oxide and the EB-Power was 30 kV-1.5 A. .

<Embodiment 5> The deposition material is aluminum, E
Except that B-Power was performed at 30 kV-2.0 A
A gas barrier laminate of Example 5 which was produced in the same manner as in Example 1 was produced.

Comparative Example 1 A gas barrier laminate of Comparative Example 1 was prepared in the same manner as in Example 1, except that a solution of a urethane resin was used instead of the aqueous solution of the organosilicon compound.

Comparative Example 2 A gas barrier laminate of Comparative Example 2 was prepared in the same manner as in Example 1 except that a nitrocellulose solution was used instead of the aqueous solution of the organosilicon compound.

Comparative Example 3 The gas barrier laminate of Comparative Example 3 was prepared in the same manner as in Example 1 except that a solution of a vinyl acetate-vinyl chloride copolymer was used instead of the aqueous solution of the organosilicon compound. The body was made.

Comparative Example 4 Aluminum was directly vapor-deposited on one side of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm by an EB heating vacuum apparatus. A 30 μm-thick unstretched polypropylene film (thermal adhesive resin) was laminated to produce a gas barrier laminate of Comparative Example 5.

<Evaluation> Five types of gas barrier laminates of Examples 1, 2, 3, 4, and 5 were prepared, and Comparative Examples 1, 2, 3, and 3 were prepared. Example 4
To compare and evaluate the four types of gas barrier laminates,
The oxygen permeability and moisture permeability indicating the barrier properties of each gas barrier laminate and the peel strength indicating the adhesion between the deposited thin film layer and the adjacent layer were measured. The results are shown in Table 1. The measurement conditions were as follows: oxygen transmission rate: MOCON-OXTR method
AN-10 / 50A), setting 25 ° C-100% RH Permeability: Mocon method (MOCON-PARMATRAN-W6), setting 40 ° C-90% R
H peel strength: Tensilon tensile tester, sample 15mm
The width, the peel angle were 90 °, and the peel speed was 300 mm / min.

[0030]

[Table 1]

Referring to Table 1, Examples 1, 2, 3, 4, and 5 show the gas barrier properties against oxygen and water vapor and the adhesion between the deposited thin film layer and the adjacent layer. The strength was good. Comparative Example 1,
In Comparative Examples 2 and 3, the adhesion of the deposited thin film layer was good, but the gas barrier properties were poor. In Comparative Example 4, the gas barrier property was good, but the adhesion of the deposited thin film layer was poor.

[0032]

According to the present invention, an organosilicon compound layer is formed between a synthetic resin film substrate and a deposited thin film layer,
Since the entire surface of the organosilicon compound layer is plasma-activated, the adhesion of the deposited thin film to the film substrate and the flexibility against external loads are improved, and the occurrence of cracks and pinholes in the deposited thin film can be prevented, Provided is a gas barrier laminate of a packaging material having good barrier properties against oxygen and water vapor.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a gas barrier laminate according to an example of the present invention.

FIG. 2 is a cross-sectional view of another example of the gas barrier laminate of the present invention.

[Explanation of symbols]

 100, 200: Gas barrier laminate 110: Synthetic resin film 120: Organosilicon compound 121: Plasma activated surface 130: Evaporated thin film 140: Adhesive 150: Thermal adhesive resin layer

Claims (3)

(57) [Claims] 1. A synthetic resin film having a chemical formula of R—Si— (OR ′) ₃ (R is an organic functional group, O
R 'is a hydrolyzable group), and a metal or metal compound vapor-deposited thin film layer is formed on the surface of the organic silicon compound layer which has been plasma-activated by an oxygen-containing mixed gas. A gas barrier laminate comprising: 2. The organic silicon compound layer according to claim 1, wherein the organic functional group (R) is —CH ＝ CH ₂ , —CH ₂ —CH
_{2 -CH 2 -NH 2, -CH 2} -NH 2, -CH 2 -N
HCONH ₂ , —CH ₂ —NH—CH ₂ —CH ₂ —NH
_{2, - (C 2 H 2} O) -, - CH 2 -O-CH 2 - (C 3
In H ₃ O), the hydrolyzable group (OR ') is, -OCH
₃ , -OCH ₂ -CH ₃ , -OCH ₂ -O-CH ₃ . 3. A gas barrier laminate comprising a heat-adhesive resin layer provided on the surface of the metal or metal compound vapor-deposited thin film layer according to claim 1 or 2 via an adhesive layer.