JPH11262986A - Polyamide film and laminated material with excellent barrier properties - Google Patents

Abstract

(57) [Summary] A biaxially stretched polyamide film is used as a deposition base material.
An object of the present invention is to provide a barrier film having a small adhesion strength of the deposited layer in the deposited film provided with the inorganic compound deposited layer. A vapor deposition layer made of an inorganic compound is provided on a biaxially stretched polyamide film via an anchor coat layer made of a composition containing at least an acrylic polyol, an isocyanate compound, and a trifunctional onorganosilane or a hydrolyzate thereof. A barrier material 1 in which a coating layer 4 of a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof is provided on a vapor deposition surface of a vapor deposition film provided with, and an adhesive 5 on the coating layer 3 of the barrier material 1 And a heat-sealing resin layer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a vapor-deposited film in which a biaxially stretched polyamide film is provided with a vapor-deposited inorganic compound layer containing a metal oxide such as silicon oxide or aluminum oxide, and a laminated material using the vapor-deposited film. It is related to.

[0002]

2. Description of the Related Art In recent years, as a barrier material in place of aluminum foil, a transparent vapor-deposited film in which a vapor-deposited layer of an inorganic compound such as silicon oxide or aluminum oxide is provided on a plastic film has been frequently used.

[0003] A polyethylene terephthalate film (hereinafter referred to as a PET film) is generally used as a plastic film as a vapor deposition base material of the vapor deposition film. The vapor deposition film using this PET film has an advantage that the vapor deposition layer can be stably laminated. However, compared to a polyamide film (hereinafter referred to as a Ny film), flexibility and piercing strength are inferior, so that it has not been practically used in the field of vacuum packaging. On the other hand, the Ny film has the above-mentioned advantages, but has a hygroscopic property. Therefore, when a vapor-deposited layer of an inorganic compound is formed, the adhesive strength of the vapor-deposited layer is reduced due to the absorption of moisture over time, so that it is not practical. .

Here, as means for improving the adhesion strength between the vapor deposition layer and the plastic film, a corona discharge treatment, a plasma treatment, and an anchor coat layer are provided on the vapor deposition surface of the plastic film. Thus, in order to increase the adhesion strength between the respective layers, corona discharge treatment,
Even if surface treatment such as plasma treatment is taken, the adhesion strength of the deposited layer is reduced due to the influence of moisture and the contents, and the deposited layer floats when peeled or bent between layers. I was Further, even with a configuration in which an anchor coat layer made of a general adhesive, for example, a two-component curable urethane-based adhesive is provided, the adhesion strength of the vapor deposition layer similarly decreases due to the influence of moisture and the contents. When the layers were peeled off or bent, the vapor deposition layer floated.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a biaxially stretched N
Provided is a barrier film in which the adhesion strength of the deposited layer is small, a laminated material using the barrier film, and the laminated material, in a deposited film provided with an inorganic compound deposited layer using a y film as a deposited substrate. The purpose is to do.

[0006]

According to the present invention, at least one of an acrylic polyol, an isocyanate compound, and a compound represented by the general formula R'SI (O
R) ₃ (R ′: an alkyl group, a vinyl group, a glycyoxypropyl group, R: an alkyl group), and a trifunctional organosilane represented by R 3 or an anchor coat layer composed of a composition containing a hydrolyzate of an organosilane. And a polyamide film having an excellent barrier property, provided with an inorganic compound vapor-deposited layer. The invention according to claim 2 is a polyamide film having excellent barrier properties, wherein R ′ constituting the trifunctional organosilane contains an epoxy group. The invention according to claim 3 is a polyamide film having excellent barrier properties, wherein the composition constituting the anchor coat layer includes a reaction catalyst comprising a tin compound. According to a fourth aspect of the present invention, the composition constituting the anchor coat layer has a general formula M (OR) _n
(M: metal element, R: alkyl group such as CH ₃ or C ₂ H ₅ , n: oxidation number of metal element) Metal alkoxide or hydrolyzate of metal alkoxide, characterized in that it has a barrier property. Is an excellent polyamide film.

According to a fifth aspect of the present invention, there is provided a polyamide film having excellent barrier properties, wherein a coating layer containing a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof is provided on the surface of the vapor deposition layer. . The invention according to claim 6 is a polyamide film having excellent barrier properties, wherein a coating layer containing a water-soluble polymer and tin chloride is provided on the surface of the vapor deposition layer.

The invention according to claim 7 is characterized in that a heat-sealing resin layer is provided via an adhesive layer on either the vapor deposition layer surface or the coating layer of the polyamide film. It is a laminated material. The invention according to claim 8 is a laminated material having excellent barrier properties, wherein a heat buffer layer is provided between the polyamide film and the heat seal resin layer. The invention according to claim 9 is a laminated material having excellent barrier properties, wherein the heat-sealing resin layer is made of a non-stretched polypropylene film. The invention according to claim 10 is a laminated material having excellent barrier properties, wherein the heat-sealable resin layer is formed of a polyolefin film polymerized by a metallocene catalyst.

The invention according to claim 11 is a bag-like packaging container using the laminated material. The invention according to claim 12 is a molded packaging container using the laminated material for a sealing lid.

[0010]

When the vapor-deposited substrate of the present invention is a biaxially stretched polyamide film, at least an acrylic polyol, an isocyanate compound and a general formula R′SI (OR) ₃ (R ′: alkyl group, vinyl group, A composition containing a trifunctional organosilane or a hydrolyzate of an organosilane represented by a kind of glycioxypropyl group, R: alkyl group, or the above-mentioned composition,
R) _n (M: metal element, R: alkyl group such as CH ₃ , C ₂ H _5, etc., n: oxidation number of metal element) A metal alkoxide or a composition containing a hydrolyzate of metal alkoxide was used. As a result, the inorganic compound vapor-deposited layer has a small decrease over time and is practically usable. This makes it possible to obtain a laminated material in which the adhesion strength between the biaxially stretched polyamide film provided with the inorganic compound vapor-deposited layer and the heat-sealable resin layer via an adhesive is sufficiently maintained.

[0011]

FIG. 1 shows an example of the present invention and is a cross-sectional view for explaining the structure of a laminated material using a transparent barrier material.

In FIG. 1, reference numeral 1 denotes a barrier material;
Is a Ny film, 3 is an inorganic compound deposited layer, 4 is a coating layer,
5 is an adhesive, 6 is a heat-sealing resin layer, and 9 is an anchor coat layer. The Ny film 2 is a biaxially stretched film and is usually used as a packaging material.
6-Ny and 6,6-Ny can be used.

Known additives such as, for example, an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant, and a coloring agent can be added to the Ny film 2, and they are added as needed.

Specific examples of the material used for the anchor coat layer 9 include at least an acrylic polyol, an isocyanate compound, and a compound represented by the general formula R′SI (OR) ₃ (R ′: an alkyl group, a vinyl group, a glycyoxypropyl group,
R: an alkyl group), a composition containing a trifunctional organosilane or a hydrolyzate of an organosilane, or a composition containing the general formula M (OR) _n (M: metal element, R: C)
A metal alkoxide represented by an alkyl group such as H ₃ or C ₂ H ₅ , n: oxidation number of a metal element, or a composition containing a hydrolyzate of a metal alkoxide is used.

Here, the acrylic polyol is a polymer obtained by polymerizing an acrylic acid derivative monomer, or a polymer obtained by copolymerizing an acrylic acid derivative monomer and another monomer, having a hydroxyl group at a terminal. And reacts with the isocyanate group of the isocyanate compound of the curing agent. Specifically, ethyl methacrylate, hydroxyethyl methacrylate,
A polymer obtained by polymerizing an acrylic acid derivative monomer such as hydroxypropyl methacrylate or hydroxybutyl methacrylate alone, or an acrylic polyol obtained by copolymerizing with another monomer such as styrene is preferable. In view of the reactivity with the isocyanate compound, a polymer having a hydroxyl value in the range of 5 to 200 (KOH mg / g) is preferable.

The above-mentioned trifunctional organosilanes include, specifically, ethyltrimethoxysilane, vinyltrimethoxysilane and glycidoxypropyltrimethoxysilane. Among them, glycidoxytrimethoxysilane and epoxycyclohexylethyltrimethoxysilane containing an epoxy group are preferable.

The compounding ratio of the trifunctional organosilane to the acrylic polyol is preferably in the range of 1/1 to 100/1 by weight, particularly preferably in the range of 2/1 to 50/1. And
The solvent or diluting solvent used is not particularly limited, and specifically, esters such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as methyl ethyl ketone, toluene and xylene And the like, or a mixture of aromatic hydrocarbons. In particular, a solvent obtained by mixing isopropyl alcohol or the like with ethyl acetate as a polar solvent is preferable.

It is effective to add a reaction catalyst to promote the reaction at the time of mixing the trifunctional organosilane and the acrylic polyol. As the reaction catalyst, tin chloride (SnCl ₂ , SnCl ₄ ), tin oxychloride (SnOH
Tin compounds such as Cl, Sn (OH) ₂ Cl ₂ ), and tin alkoxide can be used. The catalyst may be added directly at the time of compounding, or may be added after being dissolved in a solvent such as methanol. The amount added is preferably in the range of 1/10 to 1 / 10,000, more preferably in the range of 1/100 to 1/2000 with respect to the molar ratio of the trifunctional organosilane.

The isocyanate compound which reacts with the acrylic polyol is for forming a urethane bond by the reaction, and specifically, aromatic tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), aliphatic xylene Diisocyanate (X
DI), a monomer such as hexadiisocyanate (HMDI), a polymer, or a derivative. The mixing ratio of the acrylic polyol and the isocyanate compound is not particularly limited. However, if the amount of the isocyanate compound is small, curing may be poor. Occurs. Therefore, the compounding ratio is in the range of 50 times or less, preferably equal to, the NCO group of the isocyanate compound and the OH group derived from the acrylic polyol.

Further, the metal alkoxide, or a metal alkoxide,
The hydrolyzate is tetraethoxysilane [Si (OC
_TwoH_Five)_Four], Tripropoxy aluminum [Al (O
C_ThreeH₇) _Three] And the stability is excellent.
You. The metal alkoxide or its hydrolyzate and
The mixing ratio with the trifunctional organosilane is 1:10 to 1:
The range of 1 is obtained in a stable state.

The inorganic compound deposited layer 3 is made of an oxide, nitride, or the like of silicon, aluminum, titanium, zirconium, tin, or the like.
It is composed of a simple substance of fluoride or a composite thereof, and is formed by a vacuum deposition method, a sputtering method, a plasma vapor deposition method (CV).
D method) or the like. The thickness of the inorganic compound deposition layer 3 is in the range of 100 to 2000 °,
Preferably it is in the range of 400-1000 °. Also,
The composition of the deposited layer is not particularly limited by heat sterilization at a low temperature, but for sterilization at a high temperature such as a retort, a simple substance of aluminum oxide or a composition containing aluminum oxide as a main component is preferable.

The coating layer 4 is composed mainly of an aqueous solution containing a water-soluble polymer and at least one of (a) one or more metal alkoxides and hydrolysates thereof, and (b) tin chloride, or a mixed solution of water / alcohol. And a coating agent. A water-soluble polymer and tin chloride are converted to an aqueous system (water or water /
Alcohol mixture) A solution obtained by coating a solution dissolved with a solvent or a solution obtained by mixing a solution obtained by directly or beforehand hydrolyzing a metal alkoxide on the inorganic compound vapor-deposited layer 3 and then drying by heating. It is. Each component contained in the coating agent will be described in detail below.

The water-soluble polymer used for the coating agent in the present invention includes polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate and the like. In particular, when polyvinyl alcohol (PVA) is used as the coating agent for the gas barrier laminate of the present invention, the gas barrier properties are most excellent. The PVA referred to here is generally obtained by saponifying polyvinyl acetate, and ranges from so-called partially saponified PVA in which tens of percent of acetic acid groups remain to fully saponified PVA in which only a few percent of acetic acid groups remain. Including
There is no particular limitation.

In addition, tin chloride is stannous chloride (SnC).
l ₂ ), stannic chloride (SnCl ₄ ), or a mixture thereof, and either an anhydride or a hydrate can be used.

Further, the metal alkoxide is represented by a general formula such as tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ], triisopropoxy aluminum [Al (O-2′-C ₃ H ₇ ) ₃ ], M (OR) _n (M: metal such as Si, Ti, Ai, Zr, R: CH ₃ ,
(An alkyl group such as C ₂ H ₅ ). Among them, tetraethoxysilane and triisopropoxyaluminum are preferable because they are relatively stable in an aqueous solvent after hydrolysis.

Each of the above-mentioned components can be added to the coating agent alone or in combination of several components. Further, as long as the barrier properties of the coating agent are not impaired, isocyanate compounds, silane coupling agents, dispersants, and stabilizers Known additives such as a viscosity modifier and a colorant can be added.

For example, an isocyanate compound to be added to a coating agent has two or more isocyanate groups (NCO groups) in its molecule. For example, tolylene diisocyanate (TDI), triphenylmethane triisocyanate (TTI), There are monomers such as tetramethylxylene diisocyanate (TMXDI), and polymers and derivatives thereof.

As a method for applying the coating agent, conventionally known means such as a dipping method, a roll coating method, a screen printing method, and a spraying method are used. Although the thickness of the film varies depending on the type of the coating agent, the thickness after drying may be in the range of about 0.01 to 100 μm. It is desirable that the thickness be 50 μm.

The barrier material having the above-described structure is provided in one layer in the laminated material of the present invention. If a higher barrier property is required, a structure in which two or more barrier materials are provided can be employed.

The heat-sealable resin layer 6 can be used according to the purpose as long as it is a resin having a heat-sealability such as polyethylene, polypropylene, ethylene copolymer, and saturated polyester. When required, a non-stretched polypropylene film, or a polyolefin synthesized using a metallocene catalyst as one having less resin odor to the contents is preferable. .

The heat-sealing resin layer 6 is preferably provided by laminating a film-forming material with an adhesive 5 interposed therebetween. It is also possible to laminate the molten resin by direct extrusion coating. As the adhesive used here, two liquids having heat resistance or 1
A liquid-curable urethane-based adhesive is preferred.

Also, as shown in FIG. 2, a laminated material in which the printing layer 7 is provided directly on the coating layer 3. As described above, the printing layer 7 can be directly provided, and as the ink used for the printing layer 7, a urethane-based ink having heat resistance and excellent adhesion strength is preferable.

Further, as shown in FIG. 3, a laminated material in which a thermal buffer layer 8 is provided on a coating layer 3 of a barrier material 1 with an adhesive 5 interposed therebetween. By providing the heat buffer layer 8 in this manner, when heat sterilization of a boil or the like is performed, the influence of heat is small, and mechanical strength such as barrier properties and drop strength can be maintained. As a film used for the thermal buffer layer 8,
A biaxially stretched nylon film and a biaxially stretched polyethylene terephthalate film are preferred.

This laminated material is made of a heat-sealable resin layer 6.
Can be formed into a bag-shaped packaging container such as a pillow packaging bag, a four-sided sealing bag, a three-sided sealing bag, a gusset-shaped bag, or a standing pouch. Further, as shown in FIG. 4, this laminated material can be used as the sealing lid 11 of the molded packaging container 10.

[0035]

<Example 1> An anchor coat layer of the following composition having a thickness of 0.1 μm was provided on an Ny film having a thickness of 15 μm, and aluminum oxide was formed on the upper surface thereof by vacuum evaporation using a resistance heating method. A 200 ° vapor deposition layer was formed, and a coating solution having the following composition was further applied by a bar coater, and dried at 120 ° C. for 1 minute with a drier to form a coating layer having a thickness of about 0.5 μm. Then, a printing layer is partially provided with a urethane-based printing ink on the coating layer, and further coated with a urethane-based two-component curable adhesive (A-515, manufactured by Takeda Pharmaceutical Co., Ltd.) by a gravure method at 4 g / m ² . An unstretched polypropylene film having a thickness of 70 μm was laminated by a dry lamination method to obtain a predetermined laminated material.

In a solvent for diluting the components of the anchor coat layer , 2- (epoxycyclohexyl) ethyltrimethylsilane (hereinafter referred to as EETMS) was mixed with 2.5 times (weight ratio) of acrylic polyol, and tin chloride /
MeOH solution (adjusted to 0.003 mol / g)
It is added so that it becomes 1/135 mol with respect to TMS,
Next, tolylene diisocyanate was mixed so that the NCO group was equivalent to the OH group of the acrylic polyol. 89.6 g of hydrochloric acid (0.1N) was added to 10.4 g of tetraethoxysilane as a component of the coating layer, and the mixture was stirred for 30 minutes, and a solution having a hydrolyzed solid content of 3 wt% (in terms of SiO ₂ ) and a polyvinyl alcohol solution were added. Mixed.

The laminated material was stored in an atmosphere of 40 ° C. and 90% RH, and the adhesion strength between the layers was measured over time. Table 1 shows the results.

Example 2 The adhesive layer of Example 1 was laminated with a linear low-density polyethylene film (40 μm in thickness) via a molten low-density polyethylene (15 μm) to obtain a laminated material. Except for the above, the same materials as in Example 1 were used. Then, it was stored in the same manner as in Example 1, and the adhesion strength between the layers was measured. Table 1 shows the results.

Example 3 The adhesive layer of Example 1 was applied via a non-sol adhesive (ADN369 manufactured by Toyo Morton).
A laminated low-density polyethylene film (thickness: 60 μm) was laminated to obtain a laminated material. Except for the above, the same materials as in Example 1 were used. Then, it was stored in the same manner as in Example 1, and the adhesion strength between the layers was measured. Table 1 shows the results.

Comparative Example 1 A laminated material was obtained in the same manner as in Example 1 except that the anchor coat layer of Example 1 was not provided. Then, it was stored in the same manner as in Example 1, and the adhesion strength between the layers was measured. Table 1 shows the results.

[0041]

[Table 1]

As is clear from Table 1, the structures of Examples 1 to 3 have a small decrease in the adhesion strength between the Ny film and the aluminum oxide deposited layer even when stored under high temperature and high humidity, and are practically usable. A problem-free laminated material was obtained. Comparative Example 1
Immediately after the test was 100 g / 15 mm or less, which was not practically practical.

[0043]

According to the present invention, since it has the above-mentioned structure, the adhesion strength of the vapor-deposited layer of the inorganic compound is small, the practical strength can be maintained, and the conventional Ny film is suitable for the packaging field. , Cheese, half-baked confectionery, rice cakes, liquid soups, etc. have also become possible.

In the case of using a laminated material, since a coating layer is provided on the vapor deposition layer of the barrier material, printing and laminating are not performed directly. Has a small decrease in barrier properties.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one example of a laminated material of the present invention.

FIG. 2 is a sectional view showing an example of another laminated material of the present invention.

FIG. 3 is a cross-sectional view showing a laminated material using another material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Barrier material 2 ... Ny film 3 ... Evaporation layer 4 ... Coating layer 5 ... Adhesive 6 ... Heat-sealable resin layer 7 ... Printing layer 8 ... Heat buffer layer 9 ... Anchor coat layer

Claims (12)

[Claims] 1. An acrylic polyol, an isocyanate compound, at least on one side of a biaxially stretched polyamide film.
And a general formula R′SI (OR) ₃ (R ′: an alkyl group,
That an inorganic compound vapor-deposited layer is provided via an anchor coat layer made of a composition containing a trifunctional organosilane or a hydrolyzate of an organosilane, which can be represented by a vinyl group or a glycioxypropyl group, and R is an alkyl group. A characteristic polyamide film with excellent barrier properties. 2. R ′ constituting the trifunctional organosilane
The polyamide film having excellent barrier properties according to claim 1, wherein the polyamide film has an epoxy group. 3. The polyamide film having excellent barrier properties according to claim 1, wherein the composition forming the anchor coat layer contains a reaction catalyst comprising a tin compound. . 4. The composition constituting the anchor coat layer has a general formula M (OR) _n (M: metal element, R: CH ₃ ,
4. An alkyl group such as C ₂ H ₅ , n: an oxidation number of a metal element, or a metal alkoxide or a hydrolyzate of the metal alkoxide. A polyamide film having excellent barrier properties as described above. 5. The barrier according to claim 1, wherein a coating layer containing a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof is provided on the surface of the vapor deposition layer. Polyamide film with excellent properties. 6. The polyamide film having excellent barrier properties according to claim 5, wherein a coating layer containing a water-soluble polymer and tin chloride is provided on the surface of the vapor deposition layer. 7. A heat-sealing resin layer provided on one of the surface of the vapor deposition layer and the coating layer via an adhesive layer, according to any one of claims 5 and 6,
Laminated material with excellent barrier properties. 8. The laminated material having excellent barrier properties according to claim 7, wherein a heat buffer layer is provided between the polyamide film and the heat sealing resin layer. 9. The laminated material having excellent barrier properties according to claim 7, wherein the heat-sealable resin layer comprises a non-stretched polypropylene film. 10. The laminated material having excellent barrier properties according to claim 7, wherein the heat-sealing resin layer comprises a polyolefin film polymerized by a metallocene catalyst. 11. A bag-like packaging container using the laminated material according to any one of claims 7 to 10. 12. The method according to claim 7, wherein:
A molded packaging container using the laminated material described in the above item for a sealing lid.