JP2000062118A - Packaging laminate - Google Patents

Abstract

(57) [Summary] [Objective] It has an oxygen barrier property, exhibits excellent durability against thermodynamic stress encountered during the production of packaging materials and containers and during the distribution process, and has no pinholes. A packaging laminate material for a paper container having excellent performance required by a packaging material for a paper container, which has excellent anti-bacterial properties, and has excellent anti-bacterial properties. The present invention provides a packaging laminate having a fibrous base material and a thin silicon oxide film formed on a plastic base film, wherein the plastic base film has an average The particle size is in the range of 1 to 80 microns,
The layered silicate is a polyamide film containing 0.1 to 10% by weight of a fine layered silicate not containing a particle diameter of 300 μm or more, and having a layer distance of 50 Å or more. A packaging laminate in which a silicon oxide film is directly deposited on the surface of the polyamide film.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a packaging laminate,
More specifically, it is a laminate for container (or carton) production, which is a laminate material for packaging in which an oxygen barrier plastic film is arranged, and one of which contains a fibrous base material, and has barrier properties with flexibility. It relates to a packaging laminate.

[0002]

Flexible packaging laminates have been used for many years to package liquid food products. Packaging containers for milk, juice, sake, shochu, mineral water and other beverages include, for example, a web-shaped packaging material with a crease line on a fibrous base material (for example, paper) / plastic laminate. Forming a tube by vertical direction vertical line seal, filling the filling material into the tube-shaped packaging material, and performing a horizontal line seal in the transverse direction of the tubular packaging material, first of all, cushion-shaped or pillow-shaped When it is formed into a primary shape, and the packaging material is a band shape, it is cut into pieces at regular intervals and folded along a crease line to form a final shape. As the final shape, in addition to the brick shape (parallelepiped), a polygonal column shape exceeding a square, a hexagonal column shape, an octagonal column shape, a decagon column shape
For example, there is a tetrahedral shape having four triangular surfaces. The fibrous base material is often thick paper.

Further, in the case of a gable top (roof type) paper packaging container, a paper packaging material is cut into a predetermined shape to obtain blanks sealed in the longitudinal direction of the container, and the bottom of the blanks is sealed in a filling machine. It is obtained by filling the filling object of milk, juice or other beverage from the upper opening later and sealing the upper portion. The exterior design of the packaging container product is printed on the surface of these packaging materials.

The packaging laminate used in the conventional paper packaging container product is a low density polyethylene (LDPE) / printing ink layer / paper (fibrous) base material layer / LDPE / aluminum foil (A
l) / LDPE / LDPE, LDPE / printing ink layer /
Paper base layer / LDPE / LDPE, printing ink layer / LDP
E / Paper substrate layer / LDPE / LDPE, LDPE /
Printing ink layer / paper base material layer / LDPE / Al / polyester (PET) and the like are known, and are actually used even now.

However, the LD used here
PE is a high-pressure low-density polyethylene, and the low molecular weight contained in the innermost layer of the high-pressure low-density polyethylene is transferred to the contents in the paper container, and the taste of the contents changes when it is stored for a long period of time. Further, in an ethylene-α-olefin copolymer obtained by using a Ziegler catalyst, the sealing temperature is high and the processability is poor, and when a lubricant is added to improve it, the lubricant migrates to the contents and reduces its taste. .

On the other hand, a paper container using an ethylene-α-olefin copolymer (so-called metallocene PE) polymerized with a single-site catalyst in the innermost layer has been proposed (Japanese Patent Laid-Open No. 148895/1995). Kaihei 8-3
37237, JP-A-9-29868, and JP-A-9-5.
2299, JP-A-9-76435, JP-A-9-14
2455, JP-A-9-86537, 9-76375.
Issue Bulletin). However, it does not necessarily show good performance in retaining and maintaining flavor, taste and flavor.

When the liquid food is, for example, citrus fruit juice, in addition to aroma-retaining properties such as flavors and flavors,
Oxygen barrier property is required. The liquid foods are penetrated by oxygen through the carton walls, thus losing their nutritional value. It is common to add an aluminum foil layer to the laminate material to reduce oxygen ingress into the carton and minimize degradation of nutrients such as vitamin C. Although aluminum foil is effective as a barrier material, its use raises environmental concerns.

Various attempts have been made to develop viable alternatives to aluminum foil. It has excellent oxygen, gas and fragrance barrier properties, yet is easily disposable after use. It has been conventionally proposed to use a vapor-deposited layer of an inorganic oxide for a packaging material for a paper container (Jpn.
068, JP-A-6-93120). With such a packaging material having gas (oxygen) blocking properties, it is possible to provide a paper container having an aroma retaining property or a quality retaining property.
However, it does not have all the performance required for the packaging material for paper containers.

In the process of packaging food products, the carton blank (packaging material) has to have a proper shape so that
Folds along one or more fold lines. The overlapping portions of the ends of the packaging laminate are then formed and the seal can be formed by adding a suitable adhesive or heat sealing the thermoplastic layers together. As described above, making a crease in the laminate material induces stress in the laminate material. This stress can cause cracks or pinholes in the packaging container wall to induce leakage, or at least significantly weaken the laminate material, resulting in carton leakage during subsequent handling.

Recent developments in the development of plasma-assisted deposition techniques on plastic films have led to the development of new oxygen barrier materials. Among them,
Thermoplastic polyester films coated with a thin silicon oxide layer are of great interest to the food and pharmaceutical packaging industry. The materials exhibit excellent resistance to the thermodynamic stresses encountered during the various conversion processes present during manufacturing.

A limiting factor in the process and distribution process is the durability of the barrier layer. It should not crack and should not delaminate from the substrate. Cracking is controlled by the agglomeration of oxide materials, whereas delamination is controlled by interfacial adhesion. The present invention has been obtained as a result of close examination of the effect of internal stress, which tends to occur during the manufacture of the packaging material and the container, with respect to the adhesion with the interface.

[0012]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned background, and an object thereof is to provide an oxygen barrier property and heat encountered during manufacturing of packaging materials and containers and during distribution process. It has excellent durability against mechanical stress, does not generate cracks or pinholes, has excellent fragrance and quality retention, has high disposability, and can reduce environmental load. It is intended to provide a packaging laminate material for a paper container having the good performance required by the packaging material for a paper container, which comprises:

[0013]

The above problems are solved by the packaging laminate according to the present invention. That is, the packaging laminate is a packaging laminate having a fibrous base material and a thin silicon oxide coating formed on a plastic base material film, and the plastic base material film is substantially contained in polyamide. It is a polyamide film containing finely dispersed layered silicate that is uniformly dispersed, and is characterized in that a silicon oxide film is vapor-deposited on at least one surface of this polyamide film. In particular,
This plastic substrate film has an average particle size in the range of 1 to 80 microns in polyamide, and
0.1 to 1 layered silicate containing no particle size of more than micron
The layered silicate containing 0% by weight is a polyamide film in which the interlayer distance is substantially evenly distributed over 50 angstroms or more, and a silicon oxide film is vapor-deposited on at least one surface of the polyamide film. It is characterized by.

In a preferred embodiment of the present invention, the silicon oxide coating formed on the plastic substrate film is a carbon-containing silicon oxide coating obtained by vapor deposition by a plasma CVD method (PECVD method), A packaging laminate in which carbon-containing silicon oxide is represented by the following composition formula. SiOxCy (where x is in the range of 1.5 to 2.2 and y is in the range of 0.15 to 0.80)

In a preferred embodiment of the packaging laminate according to the invention, the layered silicate is Ag, Zn, Co, Cd, Cu.
It is a clay mineral having an ion of a metal selected from the following or a hydroxide or oxide thereof between the layers.

In a preferred embodiment of the packaging laminate according to the present invention, the constituent layers of the sealing resin layer, the fibrous base material layer, the adhesive layer, the plastic base material film and the silicon oxide coating are laminated in the above order. It is characterized by consisting of.

A preferred embodiment of the packaging laminate for paper containers according to the present invention is characterized in that it is provided with a fold line and is folded and finally formed.

The deposited silicon oxide obtained by vapor deposition by the plasma CVD method is preferably a carbon-containing silicon oxide film, and the carbon-containing silicon oxide has a composition formula SiOxCy (wherein, x is preferable). Is 1.5-2.
2, y is in the range 0.15 to 0.80, more preferably x is in the range 1.7 to 2.1 and y is in the range 0.39 to 0.47. Yes).

As mentioned above, the above equation does not mean that the silicon oxide deposited by plasma enhanced chemical vapor deposition (PECVD, plasma CVD) is pure SiOx. This silicon oxide is formed by a plasma discharge containing a gas mixture of oxygen, helium, and an organosilicon compound as a silicon precursor. This organosilicon compound contains many carbon atoms that participate in the plasma discharge. Some of the carbon atoms are incorporated into the deposited layer. The remaining carbon atoms are simply in the form of various hydrocarbons,
It goes out with the exhaust gas.

Plasma enhanced chemical vapor deposition (PECVD,
Alternatively, the plasma CVD method itself is a known method. This approach, when applied in accordance with the present invention, works as follows. In an example of an apparatus for continuously performing the method for producing a silicon oxide film according to the present invention, a vacuum chamber for forming a process zone, a pump communicating with the chamber, a means for supplying a raw material mixed gas, and a plastic chamber for the vacuum chamber. The roll includes a roll for feeding the base film and winding the obtained film, and a drum for mounting the base film and depositing an oxide on the base film.

In a preferred embodiment of the invention, the chemical plasma deposition process described above is controlled as follows. The maximum force that is determined by the elastic modulus of the plastic base film that does not cause plastic deformation of the base material, or the minimum force that improves the cohesive force of the oxide film and the adhesion between the oxide film and the base film. A carbon-containing silicon oxide film is vapor-deposited on the substrate film by a plasma CVD method while pulling the substrate film within a force range to obtain a silicon oxide film.

In a preferred embodiment of the present invention, in this apparatus example, the pulling force of the plastic substrate film is controlled by controlling the electric motor of the feeding roll (UW) and the electric motor of the winding roll (RW). In a preferred embodiment of "the plastic base film does not undergo plastic deformation, the maximum force determined by the elastic modulus of the base film, the cohesive force of the oxide film and the adhesion between the oxide film and the base film "Minimum force to improve force" range. In the case of the drumless device shown in the above device example, this substrate film can be pulled during vapor deposition in the same manner.

In the present invention, for example, tetramethyl.
A mixture of a vaporized organosilicon compound such as Desiloxane (TMDSO) or Hexamethyl Desiloxane (HMDSO) and an inert gas (eg, helium) and oxygen gas is provided in the vacuum chamber. When the plasma is ignited there, the vaporized silicon compound reacts with oxygen to form the associated carbon-containing silicon oxide compound. The compound is deposited on a plastic substrate film cooled in a vacuum chamber. Or it is chemically bound.

By regulating the amount of the raw material gas such as oxygen in the gas mixture supplied into the vacuum chamber, the chemical reaction in the vacuum chamber is controlled, and the silicon oxide thus formed is converted into SiOxCy. It is possible to do so by occupying the chemical formula In this formula, x is preferably in the range of 1.5 to 2.2 and y is 0.
15 to 0.80, more preferably x is 1.7 to
The range of 2.1, y changes the range of 0.39 to 0.47. In a preferred embodiment of the present invention, x and y in the above composition formula are controlled. It has been demonstrated that carbon-containing silicon oxides formed in this range exhibit optimum properties with respect to oxygen gas / aroma barriers and other property values of value for packaging laminates. The average atomic concentration of the carbon-containing silicon oxide coating film obtained by the production method according to the above-described embodiment, which was analyzed by ESCA, was 30.1 ± 5.0% for silicon and 57.3 ± 5.0% for oxygen. ,
Carbon: 12.6 ± 5.0%. This result shows that the composition formula of the carbon-containing silicon oxide is SiO1.90C0.419.

The silicon oxide compound is formed directly on the surface of the plastic substrate film. The tightness of the silicon oxide layer on the plastic substrate film thus formed is sufficiently high from the viewpoint of the barrier. As a result, the durability is greatly improved, and it is possible to prevent the desired barrier properties from being lost even if the silicon oxide layer is made extremely thin.

The polyamide film used in the present invention is a molded product of a mixture containing polyamide and fine layered silicate uniformly dispersed therein. In other words, the preferred plastic substrate film in the present invention is a polyamide film containing minute layered silicates which are substantially uniformly dispersed in the polyamide. Preferably, the average particle size of the polyamide is 1 to
0.1 to 10% by weight of a layered silicate in the range of 80 microns and not containing a particle size of 300 microns or more, and the layered silicate is dispersed substantially uniformly with an interlayer distance of 50 Å or more. It is a highly flexible thermoplastic material of a polyamide film.

The polyamide that constitutes the polyamide film in the present invention means an acid amide bond (--CHNH) in the molecule.
-), For example, ε-caprolactam, 6-aminocaproic acid, ε-enanthlactam, 7
-Aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-pyrrolidone, α-piperidone, or other polymers or copolymers, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine Polymers or copolymers obtained by polycondensing diamines such as metaxylylenediamine and dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, and sebacic acid, or blends thereof. The polyamide preferably has an average molecular weight of 9,000 to 30,000.

In the present invention, the layered form of fine silicate means, for example, 0.002-1 μm on one side and 6-2 on the thickness side.
It indicates a unit of a substance of 0Å. The interlayer distance of the layered silicate refers to the distance between the centers of gravity of flat plates of the layered silicate.
And when the layered silicate is uniformly dispersed, when the layered silicate is dispersed in the polyamide, 50% or more of the layered silicate is separated into individual pieces without forming a lump, and parallel and / or randomly, 100Å It means a state in which the above interlayer distance is maintained and is molecularly dispersed, and more preferably 70% or more of the layered silicate is in such a state.

Examples of the raw material for such layered silicates include layered phyllosilicate minerals composed of layers of magnesium silicate or aluminum silicate. Specifically, 1: 1 type layered silicate, that is, kaolinite, dickite, halloysite, antigonite, chrysotile, etc., and 2: 1 type layered silicate, that is, montmorillonite, hectorite, fluorohectorite, saponite. ,
Smectites such as beidellite, subtilin and vermiculite, micas such as muscovite and phlogopite, fluorophlogopite, fluoro muscovite, swelling synthetic micas such as K-type fluoro-teniolite and K-type tetrasilicon mica, Li-type Swellable synthetic fluoromica such as fluorteniolite (the following formula a), Na-type fluorteniolite (the following formula b), Na-type tetrasilicon fluoromica (the following formula c), margarite, pyrophyllite, talc, chlorite, etc. Is mentioned. From the viewpoints of surface appearance, product coloring, and gas barrier properties, among them, montmorillonite, hectorite, fluorine hectorite, swelling synthetic fluoromica and the like are preferable, montmorillonite and swelling synthetic fluoromica are more preferable, and particularly swelling synthetic fluorine. Mica is preferred.

In a preferred embodiment of the present invention Na,
Metal ions other than K, Li and Ca (eg Ag, Z
A metal ion selected from n, Co, Cd, and Cu) or a layered silicate (clay mineral) having a metal compound thereof between the layers can be used. This layered silicate itself is Pseudomonas aeruginosa,
It has excellent antibacterial properties against various microorganisms such as Escherichia coli and Staphylococcus aureus. Therefore, the antibacterial property is imparted to the plastic substrate film containing the layered silicate, and the antibacterial property is imparted to the packaging laminate according to the present invention in which the film is laminated. In this method for producing an antibacterial layered silicate, for example, a water-swellable clay mineral is added to Ag, Zn, C
a water-soluble salt of a metal selected from o, Cd, and Cu,
For example, the antibacterial layered silicate containing metal ions can be obtained by dispersing the precipitate in an organic solvent such as methanol or acetone and separating the precipitate, washing and drying. In another method, an antibacterial layered silicate having a metal hydroxide can be obtained from a precipitate obtained by dropping an alkaline solution into the above dispersion liquid.

The amount of the layered silicate compounded is preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, based on the polyamide. When the amount of the layered silicate is less than 0.05% by weight, the effect of improving oxygen barrier properties, stress durability, aroma retention and quality retention is low, which is not preferable. It is not preferable because it significantly decreases.

As a constituent component of the polyamide film in the present invention, a lubricant, an antioxidant, a heat stabilizer, a weather resistance imparting agent, an antistatic agent, a transparency improving agent and the like may be added as necessary. You can

There is no particular limitation on the method for uniformly dispersing the layered silicate in the polyamide. For example, when the raw material of the layered silicate is a multi-layered clay mineral, a method of contacting with a swelling agent to expand the layers in advance to facilitate incorporation of a monomer between the layers, then mixing with a polyamide monomer, and polymerizing ( JP-A-62-74957) can be applied. Further, it is possible to use a method in which a polymer compound is used as a swelling agent, the interlayer is preliminarily expanded to 100 liters or more, and this is melt-kneaded with a polyamide resin or a resin containing the polyamide resin and uniformly dispersed. Furthermore, a polyamide composition containing a layered silicate at a high concentration is prepared in advance by the above method,
A method of mixing the composition and a polyamide containing no layered silicate can be applied.

The method of forming a film is not particularly limited. In the present invention, the polyamide film can be in the form of either a stretched film or an unstretched film. As a method for forming an unstretched film, for example, a polyamide containing a layered silicate is used.
Melt kneading with an extruder at an extrusion temperature of 0 to 300 ° C., extruding into a film shape with a T die, and cooling the film cast on the surface of a casting roll (T die method), or a ring die to form a cylinder. Each direction of a tubular method in which an extruded product is air-cooled or water-cooled can be applied.

As a method of forming a stretched film, an unstretched film formed by a casting method or a tubular method is uniaxially or biaxially stretched at a stretching temperature of 50 to 180 ° C. and, if necessary, at 120 ° C. or higher. A method of heat fixing at a temperature lower than the melting point can be applied. When carrying out biaxial stretching, a known method such as a tenter biaxial stretching method or a tubular biaxial stretching method can be applied.

In the present invention, the polyamide film is
A laminate composed of the polyamide film containing the uniformly dispersed layered silicate described above and a polymer film other than the polyamide film can also be used. Other polymer films include low density polyethylene film, high density polyethylene film, linear low density polyethylene (LLDP).
E), metallocene PE, polypropylene film, ethylene-vinyl acetate copolymer film, ionomer resin film and the like. In the present invention, a thin silicon oxide film is directly formed on at least one surface of the polyamide film.

The method of forming the polyamide film into a laminate is not particularly limited. For example, a method of adhering the polyamide film and another one or more polymer films with an adhesive, or a polyamide and one or more kinds of polymer films. The method of melt coextruding the polymer compound constituting the other polymer film from the multilayer spinneret through the adhesive resin can be applied.

PECVD in a preferred embodiment of the present invention
The silicon oxide layer formed by the method can withstand considerable elongation before breaking. This is a particularly important property when a silicon oxide layer is incorporated into a laminate material to enclose and package a liquid food product. Typically, the packaging laminate comprises fold lines formed in the surface of the laminate to facilitate bending and folding to form the package.

The ability of the silicon oxide layer to exhibit good resistance to thermodynamic stresses encountered during packaging and container manufacture and during distribution and to prevent cracks and pinholes, ie, deformation without destruction. Therefore, leakage does not occur along these bending lines. The thin film silicon oxide layer formed by plasma enhanced chemical vapor deposition according to the present invention is particularly useful for encapsulating liquid food products.

Further, the polyamide film of the present invention has excellent oxygen barrier properties because the layered silicate is present in the film in a state of being uniformly divided.
Excellent in aroma retention and quality retention.

A part of the mechanism of action for achieving the above effects will be described below. However, this description is for the purpose of understanding the invention and is not intended to limit the scope of the invention. In the present invention, the polyamide film exists in a state where the layered silicate is uniformly divided in the film, and a part of the fine layered silicate is finely and minutely exposed on the surface of the polyamide film. This exposed partial silicate adsorbs, bonds, or combines with the vapor-deposited silicon oxide to greatly improve the interfacial adhesion between the substrate film and the vapor-deposited silicon oxide. Therefore, it is considered that the inside of the silicon oxide film is modified so that the silicon oxide vapor-deposited on the substrate film brings about the above-mentioned good effects. Moreover, in a preferred embodiment of the present invention, the carbon-containing silicon oxide coating has a maximum force determined by the PCVD method, more preferably, the maximum force determined by the elastic modulus of the base material film that does not cause plastic deformation of the plastic base material film, The carbon-containing silicon oxide coating is plasma-coated on the base film while pulling the base film within the range of the minimum force for improving the cohesive force of the oxide coating and the adhesion between the oxide coating and the base.
Since a silicon oxide film is obtained by vapor deposition by the VD method,
The tightness of the silicon oxide layer on the plastic substrate film is increased, and the durability against various stresses is improved. The barrier properties against oxygen and aroma of the packaging laminate according to the present invention are contributions from the silicon oxide coating and the layered silicate-containing polyamide film. It has been conventionally known that the silicon oxide coating and the layered silicate-containing polyamide film each have a barrier property. However, the barrier property was not considered by directly laminating these. In the evaluation of the present invention, the barrier property is improved by about 34% from the added value of the respective barrier properties, demonstrating the synergistic effect of combining these.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION It will be shown how well the present invention can be carried out. Various processes for forming a thin film on a substrate using the PECVD method are known. U.S. Pat. No. 4,88
No. 8,199 describes a process for depositing a thin film on the surface of a substrate utilizing plasma under controlled conditions.
The plasma is formed in an enclosed reaction chamber in which a substrate is placed and a thin film is deposited on its surface. The substrate can be formed of metal, glass or some kind of plastics, but in the present invention is a layered silicate containing polyamide film. Air is pumped out of the chamber until a high vacuum is obtained.

For example, an organosilicon compound such as hexamethyldisiloxene is introduced into the chamber with oxygen and helium, thus depositing silicon and oxygen molecules on the surface of the substrate. The resulting membrane is extremely hard according to said patent 4,888,199,
It is said to be a thin film that is hard to be scratched, is optically transparent, and adheres well to a highly flexible substrate. (See, U.S. Patents and U.S. Pat.
(No. 441)

In the process described herein, for example, the substrate on which silicon oxide is deposited is about 10
The temperature is kept at .about.35.degree. C., preferably at 15.about.25.degree. C., and in the present invention, the plastic substrate film is a molded product or film of a mixture containing polyamide and layered silicate uniformly dispersed therein. . In the present invention, the thickness of the silicon oxide film is, for example, 1 Å (angstrom) to about 40,000 Å, and the base film is for food packaging applications having a thickness of, for example, 0.15 to 25,000 μ, and is required. The thickness of the silicon oxide film is, for example, 10 Å (angstrom) to about 400.
The base film has a thickness of, for example, 1.0 to 5
For use in food packaging of 000μ, further, the thickness of the silicon oxide film is, for example, 100Å (angstrom) to about 400Å, and the base film is food packaging with a thickness of, for example, 1.5 to 500μ. It is intended for use.

[0045]

EXAMPLES Examples of preparation examples of polyamide, which is a plastic substrate film in the present invention, are shown below. The average thickness of one unit of layered silicate is 8Å and the length of one side is about 0.
2.3 g of 100 g of 1 μm raw material montmorillonite
2 l of water, and 28.1 g of 1 in 1
2-Aminododecanoic acid is evenly dispersed. 12 ml of concentrated hydrochloric acid was added to the dispersion, and the mixture was stirred at 80 ° C for 60 minutes. Furthermore, after thoroughly washing this, suction filtration is carried out using a Buchner funnel to obtain a water-containing composite. The water content of this composite is 88%. X-ray analysis shows that the interlayer distance of the layered silicate in the composite of 12-aminododecanoic acid and montmorillonite is 18.0Å. Next, ε-caprolactam is added to this complex so that the ratio of the complex of 12-aminododecanoic acid and montmorillonite to ε-caprolactam is 1: 1 and the mixture is stirred and mixed.

Next, using a twin-screw kneading extruder having a diameter of 40 mm,
Under the condition that the cylinder temperature is 250 ° C., an aliphatic polyamide resin having an average molecular weight of 30,000 consisting of 80% by weight of polyamide-6 component and 20% by weight of polyamide-66 component is dissolved, and ε-caprolactam is further added to the above composite. Is melt-kneaded while adding the second composite to which is added, and the kneaded product taken out in a strand form from the extruder nozzle is water-cooled and cut to obtain pellets composed of the aliphatic polyamide resin and the montmorillonite composite. The content of the montmorillonite complex in this aliphatic polyamide resin is 3.0% by weight.

Next, the pellets of the aliphatic polyamide resin containing the layered silicate and the crystalline aromatic polyamide resin MXD-6 obtained by polycondensation of metaxylylenediamine and adipic acid were dry blended. The polyamide resin composition is obtained by melt-kneading with a twin-screw kneading extruder and taking out the mixture taken out in a strand shape from the extruder nozzle with water cooling and cutting. The aliphatic polyamide resin containing the layered silicate and MXD-6 had a weight mixing ratio of 80/20. Diameter of the obtained pellet is 30m
melted under the conditions of a cylinder temperature of 250 ° C. with an extruder of m, extruded into a film with a coat hanger die having a die width of 300 mm, and cooled on a casting roll at 50 ° C. to obtain a casting film having a thickness of 30 μ.

[0048]

[Evaluation Example] The present invention will be specifically described with reference to the following evaluation examples of the laminated material for packaging. While pulling the layered silicate-containing polyamide substrate film, an oxide coating is deposited using the plasma-enhanced chemical vapor deposition method described above. The layered silicate-containing polyamide film on which the oxide film of the evaluation example of the present invention was vapor-deposited had a crack initiation of 4% to 6% as compared with an example using a layered silicate-free polyamide film. Shift, up about 50%. In addition, the interfacial tensile strength between the carbon-containing silicon oxide layer and the layered silicate-containing polyamide base film is 100 G, which depends on the polyamide film not containing the layered silicate.
There is a 75% increase from Pa to 175 MPa in the evaluation example according to the present invention.

The application of the oxide coated film in the present invention will be described. Liquid food products such as milk and juice are currently packaged in cartons formed from laminated packaging materials. The package may be in the form of a gable top carton or a block or polygonal package.

The application of the oxide coated film according to the present invention will be described. Liquid food products such as milk and juice are currently packaged in cartons formed from laminated packaging materials. This package is a gable top carton or brick shape (parallelepiped), as well as a tetrahedron with polygonal columns, hexagonal columns, octagonal columns, octagonal columns, and four triangular faces that exceed the square. It can be in the form of a package such as a shape. The gable-top carton is formed from a pre-scored blank, which is fed to a filling machine, which folds the blank and
The folds are sealed to form a carton, which is then filled with liquid food and the top of the carton is closed and sealed. A block-shaped or octagonal-shaped package can be formed by gradually forming a roll material made of a packaging material into a tube, filling it with a liquid food, and closing it by heat sealing. In both cases, the wrapping material is provided with fold lines to facilitate folding along a predetermined line.

The packaging blank (packaging laminate) is formed from a continuous web 2 of packaging material shown in partial view FIG.
As shown in FIG. 2, the fold line 3 is stamped or otherwise formed on the surface to be the inner surface of the carton. Laminated blanks have traditionally used paper or paperboard core layers, barrier layers, and low density polyethylene (LDP).
E) the inner product contact layer and the outer layer thermoplastic material layer of LDPE.

The fold lines usually induce recesses in the inner LDPE layer, barrier layer and core layer. The continuous web 2 is gradually wound from both ends, and the vertical line sealing portion 8 shown in FIG. 2 is heat-sealed at a temperature between 121 ° C. and 260 ° C. to be formed into a cylindrical shape, and the portion 8 of the inner and outer LDPE layers is formed.
Glued to each other. It is then transversely sealed at section 9 shown in FIG. 2 and cut there to obtain individual cartons.

The packaging laminate according to the present invention has higher durability (ductility) than the packaging laminate containing the silicon oxide coating formed by the conventional chemical vapor deposition method or the conventional plasma CVD method. A packaging laminate including the barrier layer according to the present invention does not generate cracks or holes in the barrier layer,
It can be folded and heat-sealed on an ordinary packaging machine.

It is desirable to make a thin silicon oxide. This is because the coating process can proceed more quickly in the thin range. Also,
The thicker the coating on the substrate, the more easily the laminate will curl, which makes later manufacturing more difficult. In order to utilize the barrier layer produced by the plasma-enhanced chemical vapor deposition method according to the invention as a packaging laminate for liquid foodstuffs, certain additional layers are additionally laminated.

One preferred embodiment of the packaging laminate of the present invention is shown in FIG. FIG. 1 shows an example of a packaging laminate according to the invention for producing packages exhibiting excellent oxygen gas and aroma barriers during folding and sealing. The packaging laminate 30 has a first laminating material unit 30a and a second laminating material unit 30b which are joined to each other by an intermediate adhesive layer 34 (for example, a polyethylene layer extruded by molten polyethylene). There is. First laminate material unit 30
The a has a rigid but bendable core layer 32 made of paper or paperboard and an outer coat layer made of thermoplastics (eg, low density polyethylene) 33.

The second laminate material unit 30b comprises a layered silicate-containing polyamide base film 36, a carbon-containing silicon oxide layer 37 deposited on the inner surface of the base film 36, and an outer surface of the base film 36. Intermediate adhesive layer 3
Plastic film layer 31 laminated via 5
And the carbon-containing silicon oxide layer 37 represented by the composition formula SiO1.90C0.419 acts as an oxygen gas and aroma barrier. This carbon-containing silicon oxide layer 37
In this aspect are in direct contact with the container contents. The core layer 32 of the laminating material unit 30a and the plastic film layer 31 of the laminating material unit 30b are joined via an adhesive layer 34.

FIG. 3 shows another embodiment example. In the packaging laminate (laminate material) of this aspect, the laminate material 10
Are two prefabricated laminates 10a and 1
0b, which is an intermediate layer 11 made of an adhesive.
Are bound together by. First laminating material 10a
Has a rigid but foldable core layer 12 of paper or paperboard 12 and two outer layers 13 and 14 of heat sealable LDPE.

The second laminating material 10b comprises a layered silicate-containing polyamide substrate film 15, on which a thin carbon-containing silicon oxide layer 16 is deposited by PECVD. The layer 16 acts as an oxygen gas and fragrance barrier and is composed of carbon-containing silicon oxide. Carbon-containing silicon oxide layer 16 deposited on a substrate or carrier layer 15 by PECVD method
Has a thickness of 193Å, which imparts desired oxygen gas and barrier properties to the packaging laminate 10.

The polyamide base film 15 is made of Ag, Z
Containing a layered silicate having an ion of a metal selected from n, Co, Cd, and Cu or a hydroxide or oxide thereof between the layers, and specifically containing 1% by weight of a layered silicate having a silver ion. To do.

FIG. 4 shows another embodiment of the packaging laminate according to the present invention, which is a laminate material showing excellent oxygen gas and fragrance barrier properties during crease formation and sealing. The packaging laminate 20 is bonded to each other with an intermediate adhesive layer 21 to form a first laminating unit 20.
a and the second laminating unit 20b. The first laminating unit 20a comprises a rigid but foldable layer 22 of paper or paperboard and an outer L
It has DPE layers 23 and 24.

The second laminate material unit 20b has a layered silicate-containing polyamide base film 25. On the surface facing the laminating material unit 20a, the oxygen gas and aroma barrier layer 26 made of carbon-containing silicon oxide represented by the composition formula SiO1.90C0.419 is formed.
It carries.

Layered silicate-containing polyamide substrate film 2
The other side of 5 has an outer layer 27 of thermoplastics, which layer 121 and the thermoplastics in the outer thermoplastic layer 23 of the laminate 20a.
It can be heat-sealed at a temperature between 0 ° C. and 260 ° C. and is bonded to the layered silicate-containing polyamide base film 25 via the intermediate adhesive layer 28.

In the laminate material 20 according to this example, the carbon-containing silicon oxide layer which acts as an oxygen gas and fragrance barrier is formed by the PECVD method and has a thickness of 50Å. This thickness is sufficient to impart the desired oxygen gas and aroma barrier properties to packaging containers made from the packaging laminate.

The packaging laminate 20 comprises a web of prefabricated laminate material units 20a and a web of prefabricated laminate material units 20b, between these two webs to form a completed packaging laminate 20. It can be manufactured by joining them together with an applied adhesive layer.

[0065]

The packaging laminate of the present invention (laminate material)
Is effective even in a small carbon-containing silicon oxide layer having a small thickness such as 30 to 70Å, and preferably 100 to
It is equipped with a gas barrier layer effective at a thickness of 500Å. The advantage of thin coatings lies mainly in the excellent mechanical properties associated with being able to lower their internal stress. This means that the thin coating, as described herein, has good resistance to cracking, which is particularly important in the case of folding molded containers.

The corners and folded edges of such containers are particularly sensitive areas, with materials with thicker coatings cracking in these parts of the package, resulting in loss of barrier properties. It will be done. In contrast, in the packaging laminate according to the invention, the thin coating is sufficiently flexible and extensible that even when the material is converted into a packaging container, it cracks or breaks even in the most exposed areas. There is no danger of causing The low internal stress of thin coatings is also reflected in the non-warp properties of these materials. Applying a thick coating on a plastic film may cause various problems during the subsequent laminate material manufacturing process.

In addition to having excellent oxygen gas and fragrance barrier properties, the packaging laminate according to the present invention, as mentioned above, is excellent against the thermodynamic stresses encountered during packaging and container manufacture and during distribution. Shows durability. Moreover, defects such as pinholes do not occur. Further, even if the content is particularly storage-sensitive, such as fruit juice such as citrus fruits, it has excellent aroma retention and quality retention. Since it does not use aluminum foil, which causes environmental concerns, it has a high possibility of being discarded and the environmental load can be reduced. In a preferred embodiment, the packaging laminate itself can be provided with antibacterial properties.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a packaging laminate according to the present invention.

FIG. 2 is a plan view of a packaging blank showing an application example of the packaging laminate.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the packaging laminate according to the present invention.

FIG. 4 is a schematic cross-sectional view showing another embodiment of the packaging laminate according to the present invention.

[Explanation of symbols]

2 continuous web 3 folding lines 12 core layers 15 Layered silicate-containing polyamide substrate film 16 Carbon-containing silicon oxide layer 22 core layer 25 Layered silicate-containing polyamide base film 26 Carbon-containing silicon oxide layer 32 core layer 36 Layered silicate-containing polyamide substrate film 37 Carbon-containing silicon oxide layer

Continued front page    F-term (reference) 4F100 AA03A AA17A AA20B AA25A                       AA33B AC03A AK01A AK01C                       AK01D AK46A BA02 BA03                       BA04 BA07 BA10B BA10C                       BA13 CB00 DA01 DB19 DG01A                       EH66B GB15 GB16 GB23                       JC00 JD03 JL00 JL12C                       JM02B YY00B

Claims (5)

[Claims] 1. A packaging laminate having a fibrous base material and a thin silicon oxide coating formed on a plastic base film, the plastic base film being substantially uniformly dispersed in a polyamide. Which is a polyamide film containing a fine layered silicate, and the silicon oxide film is vapor-deposited on at least one surface of the polyamide film. 2. The silicon oxide coating formed on the plastic substrate film is a carbon-containing silicon oxide coating obtained by vapor deposition by a plasma CVD method, and the carbon-containing silicon oxide has the following composition formula: Claim 1 represented by
Packaging laminate by. SiOxCy (where x is 1.5 to
2.2 is in the range, and y is in the range of 0.15 to 0.80) 3. The layered silicate is Ag, Zn, Co, C.
The packaging laminate according to claim 1, which is a clay mineral having an ion of a metal selected from d and Cu or a hydroxide or oxide thereof as an interlayer. 4. A paper container claim comprising a sealing resin layer, a fibrous base material layer, an adhesive layer, a plastic base material film, and a silicon oxide coating layer, which are laminated in the above order. Item 2. A packaging laminate according to item 1. 5. A packaging laminate according to claim 1 for a paper container which is provided with folding lines and which is folded and finally formed.