JP2000052499A - Film laminate for retort sterilization packaging and packaging bag provided with the same - Google Patents

Abstract

(57) [Problem] To provide a film laminate for retort sterilization packaging which has excellent stability of gas barrier properties against oxygen and water vapor, is easy to treat and recycle at the time of disposal, and has improved protection of food contents. A packaging bag provided with the same is provided. A film laminate in which a layer composed of a base film, a layer composed of a resin composition having an inorganic laminar compound, a layer composed of a stretched film, and a layer composed of a heat-sealing film are laminated in this order. Wherein the heat-sealable film is a multilayer film having at least a heat-sealable resin layer and a layer containing an inorganic filler and / or a light-blocking agent, wherein the heat-sealable resin layer is opposite to a layer comprising a base film. A film laminate for retort sterilization packaging, which is the outermost layer on the surface side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film laminate for retort disinfection packaging excellent in gas barrier properties against oxygen and the like, which is suitable for preserving food contents (packaged items) such as curry roux and soup. Related to packaging bags.

[0002]

2. Description of the Related Art In recent years, demand for retort foods has been steadily expanding. However, the characteristics required for packaging bags for retort foods are a recent environmental problem, PL (Products Liablit).
y) It is changing significantly due to problems and changes in cooking methods.

[0003] That is, a retort packaging bag having a structure in which aluminum foils having excellent gas barrier properties are laminated to prevent deterioration of food during long-term storage is widely used.

[0004] However, the above-mentioned conventional retort packaging bag has a problem that a large amount of metal residue due to aluminum foil remains at the time of incineration after disposal and takes much time for processing. With the increasing use of detectors and the desire of consumers to use microwaveable food packaging, there is a growing movement to remove aluminum foil from retort packaging bags. .

However, various studies have been made on retort packaging bags from which aluminum foil is omitted, but none of them have sufficiently satisfactory characteristics from the viewpoint of sterilization. For example, when an ethylene-vinyl alcohol copolymer barrier film is used, after retort treatment, the problem of the temporary deterioration of oxygen barrier properties and the ethylene-vinyl alcohol copolymer barrier film become cloudy and have an appearance. There is a problem of deterioration.

There is also known an example in which a barrier film in which silica or alumina is vapor-deposited on a biaxially stretched polyethylene terephthalate (hereinafter abbreviated as PET) film is used. However, there is a problem that the gas barrier property after the test for the presence or absence of pinhole formation is greatly reduced, and the durability with respect to the gas barrier property is poor.

Further, a polyvinylidene chloride-based film is known as a barrier film. However, since the polyvinylidene chloride-based film contains a halogen, it causes environmental problems such as generation of harmful substances such as dioxin during incineration such as disposal. Recently, the demand for non-halogenation has been increased due to the load on, and there is a problem that the demand cannot be met.

Therefore, in order to avoid the above problems and problems, the present inventors have previously proposed a retort packaging bag that does not use aluminum foil (Japanese Patent Application Laid-Open No. Hei 7-25).
1874).

[0009]

However, in the above-mentioned conventional packaging bag for retort, for example, when used in a standing pouch method without using a paper carton, the heat seal strength after retorting is reduced, or the waist is insufficient, that is, the packaging for retort is used. There is a problem that the shape maintenance becomes unstable due to the insufficient strength of the bag, and it takes time to re-heat the retort packaging bag storing the packaged items such as foods, or the protective property of the packaged item is poor. There is a problem.

The present invention is directed to a retort disinfecting packaging which has reduced waist shortage without using aluminum foil, has a light-shielding property, is made of a non-halogen resin, has excellent compatibility with environmental problems, and has an excellent gas barrier. An object is to provide a film laminate and a packaging bag provided with the same.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, a layer composed of a substrate film and a layer composed of a resin composition as a gas barrier layer containing an inorganic layered compound, By arranging a layer composed of a stretched film and a layer composed of a multilayer film having heat sealability in this order, it has been found that the protective property of the packaged object can be improved together with the gas barrier property, and the present invention has been completed. Was.

That is, in order to solve the above problems, the laminated film for retort sterilization packaging of the present invention comprises a layer composed of a base film, a layer composed of a resin composition having an inorganic layered compound, and a stretched film. And a layer made of a heat sealable film are laminated on each other in this order, and the heat sealable film is a multilayer film having at least a heat sealable resin layer and an inorganic filler and / or light-shielding agent-containing layer. The heat-sealing resin layer is the outermost layer on the side opposite to the layer made of the base film.

According to the above structure, in the layer made of the resin composition, the inorganic layered compounds face each other due to the shape of the layer, and are substantially parallel to the surface direction of the layer made of the resin composition. The orientation enables the gas barrier properties to be imparted to the layer made of the resin composition by the maze effect of the inorganic layered compound.

In addition, in the above-described structure, since the resin containing the inorganic layered compound can use a resin containing no chlorine in the layer made of the resin composition, the conventional polyvinylidene chloride-based film layer containing chlorine can be used. Compared to the case where it is provided, processing at the time of disposal and recycling can be facilitated.

[0015] Further, in the above-described structure, a layer composed of a base film, a layer composed of a resin composition, a layer composed of a stretched film, and a layer composed of a heat-sealing film are provided in this order. The film is a multilayer film having at least a heat-sealing resin layer and an inorganic filler and / or a light-shielding agent-containing layer,
The shortage of the waist can be reduced and the light-shielding property can be imparted, so that the protection of the food contents to be packaged in the packaging bag using the above configuration can be improved.

The packaging bag of the present invention is provided with the above-mentioned film laminate for disinfecting retort packaging, for example, in a bag shape so that the heat-sealable resin layer is the innermost layer.

According to the present invention, the food contents which are provided with gas barrier properties and strength, are excellent in the preservability and protection of the package, are easy to process and recycle at the time of disposal, and are packaged. A film laminate for retort sterilization packaging with improved protection of the product and a packaging bag provided with the same are obtained.

[0018]

FIG. 1 shows an embodiment of the present invention.
The following is a description based on FIG. 8.
As shown in FIG. 1, the film laminate for retort sterilization packaging of the present invention has a layer 1 composed of a base film, a layer 3 composed of a resin composition having an inorganic layered compound, and a strength (eg, tensile strength). A layer 4 made of a stretched film for application and a layer 5 made of a heat sealable film having at least a heat sealable resin layer 6 and an inorganic filler and / or light-shielding agent-containing layer 7 are laminated in this order. Is what it is. The heat-sealable resin layer 6 is formed such that, when the film laminate for retort sterilization packaging is formed in a bag shape, the heat sealable resin layer 6 is the innermost layer on the side in contact with the food to be packaged in the film laminate for retort sterilization packaging. Is set.

The film laminate for retort sterilization packaging has a layer 3 made of a resin composition having an inorganic layered compound, so that the oxygen permeability (mL / atm.multidot. m2 / day)
It has excellent gas barrier properties of 1 or less, more preferably 0.1 or less, and even more preferably 0.05 or less.

The base film of the layer 1 composed of the base film of the present invention is a water-repellent material that can hold liquid contents such as soups and pasty foods, and can prevent penetration and leakage of water. There is no particular limitation as long as it has solvent resistance to solvents such as alcohols that dissolve aromatic substances, but kraft paper, high-quality paper, imitation paper, glassine paper, parchment paper, synthetic paper, various cardboards, thermoplastic resins, and the like Is mentioned. Further, as the base film, biaxially oriented polypropylene (OPP) on which a metal or metal oxide such as aluminum evaporation, silica evaporation, and alumina evaporation is evaporated,
Biaxially stretched polyethylene terephthalate (OPET), 2
It is also possible to use axially stretched nylon (ONy).

Examples of the thermoplastic resin of the base film include polyethylene (low density, high density), ethylene-propylene copolymer, ethylene-butene copolymer,
Polyolefin resins such as ethylene-hexene copolymer, ethylene-octene copolymer, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ionomer resin, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate Polyester resins such as nylon-6, nylon-6,6, meth-xylenediamine-adipic acid condensation polymer, amide resins such as polymethylmethacrylimide, acrylic resins such as polymethylmethacrylate, polystyrene, styrene-acrylonitrile Copolymers, styrene-acrylonitrile-butadiene copolymers, styrene-acrylonitrile resins such as polyacrylonitrile, and hydrophobicized cellulose resins such as cellulose triacetate and cellulose diacetate. Loin resins, polyvinyl chloride,
Halogen-containing resins such as polyvinylidene chloride, polyvinylidene fluoride, and Teflon, high hydrogen bonding resins such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and cellulose derivatives, polycarbonate resins, polysulfone resins, polyethersulfone resins, and polyethers Examples include engineering plastic resins such as ether ketone resins, polyphenylene oxide resins, polymethylene oxide resins, and liquid crystal resins.

Among these, biaxially oriented polypropylene, polyethylene terephthalate, biaxially oriented polypropylene coated with nylon or polyvinylidene chloride called K coat, polyethylene terephthalate,
Nylon, silica, alumina, aluminum-deposited polyethylene terephthalate, polypropylene, nylon, and OPP (AS-OP) for strong antistatic use are preferably used.

Further, among these, in consideration of environmental protection at the time of disposal or recycling, a resin composed of only carbon and hydrogen, a resin composed of only carbon, hydrogen and oxygen,
For example, polyethylene, polypropylene, polyethylene terephthalate and the like are more preferable.

The heat-sealing film of the layer 5 composed of a heat-sealing film is a multilayer film having at least a heat-sealing resin layer and a layer containing an inorganic filler and / or a light-shielding agent. As the resin used for the and / or light-shielding agent-containing layer, those similar to the thermoplastic resin used for the base film can be exemplified, but in particular, when sealing properties of the contents are required, A sealant having a high impact strength is preferable, and a polyolefin resin such as a copolymer with ethylene or an α-olefin containing polypropylene and propylene as a main component, and a polyester resin such as polyethylene terephthalate are preferable because of the need to withstand high temperatures during retort. Further, a polyolefin resin such as polyethylene, ethylene-α-olefin copolymer, or polypropylene synthesized using a metallocene catalyst or a late transition metal complex catalyst is also used. The resin used for the heat-sealing resin layer and the layer containing the inorganic filler and / or light-shielding agent may be the same or different.

Examples of the inorganic filler include alkaline earth metals, oxides, hydroxides, carbonates, sulfates, and silicates of Group III elements in the periodic table. These may be used alone. However, two or more kinds may be combined. More specifically, talc, calcium carbonate, barium sulfate,
Kaolin etc. can be illustrated. Examples of the light-shielding agent include a known ultraviolet absorber, an inorganic or organic pigment, and more specifically, titanium oxide.

The method for producing a heat-sealing film having a heat-sealing resin layer and a layer containing an inorganic filler and / or a light-shielding agent is not particularly limited, and examples thereof include dry lamination, extrusion lamination, and multilayer extrusion molding. Multilayer extrusion is preferred from the viewpoint of increasing the efficiency of the manufacturing process.

In the present invention, the heat-sealable film may have a resin layer other than the above two layers, or may have one or both of the above two layers or two or more. When the film laminate of the present invention, since the heat-sealable resin layer must be the outermost layer of the film laminate, at least the outermost layer on one side of the heat-sealable film is a heat-sealable resin layer. It is necessary to have a layer structure. Further, the heat-sealing film may contain an oxygen absorbent.

The method of laminating the layer 5 composed of the heat sealable film, which is the sealant layer, on the layer 4 composed of the stretched film is not particularly limited. A preferred example is a method of dry laminating a sealing film on a stretched film. Further, the interface between the layer 5 composed of the heat-sealing film and the layer 4 composed of the stretched film may be subjected to a corona treatment, an ozone treatment, an electron beam treatment, or a treatment such as an anchor coating agent.

In the film laminate for retort sterilization packaging of the present invention, a barrier layer of a metal such as silica, alumina or aluminum or a metal oxide is further provided between any of the layers of the film laminate, for example, a resin composition. Between the layer 3 consisting of
nm, preferably 10 nm to 200 nm. With such a barrier layer, gas barrier properties can be further ensured, and light-shielding properties can be imparted. The method for forming the barrier layer is not particularly limited, and examples thereof include a vapor deposition method and a sol-gel method, and a vapor deposition method is particularly preferable.

By the way, in the conventional gas barrier container,
In order to provide gas barrier properties, a metal layer such as an aluminum foil is required to have a thickness of 7 μm to 20 μm. Therefore, when the gas barrier container is discarded, a large amount of residue of the metal layer remains and the disposal process is troublesome. Was.

However, in the present invention, by providing the above-mentioned barrier layer with a thickness of 1000 nm or less, the gas barrier property can be further ensured, the light shielding property can be given, and the above-mentioned film thickness can be set smaller than before. Disposal processing and recycling can also be facilitated.

The layer 3 composed of the resin composition of the present invention is formed, for example, by coating a coating liquid obtained by dispersing a resin composition containing a cleaved inorganic layered compound in a dispersion medium, for example, a layer 1 composed of a base film.
The resin composition is formed by coating (coating) on the film to form a coating film and removing the dispersion medium from the coating film by, for example, drying. In coating, the resin contained in the coating solution includes the resin used for the layer 1 composed of the base film described above, an ethylene-vinyl acetate copolymer emulsion, an acrylic resin emulsion, a urethane resin emulsion, and an acrylic urethane. A copolymer emulsion can be suitably used, and from the viewpoint of the dispersibility of the inorganic layered compound, a high hydrogen bonding resin is preferable.

The inorganic layered compound is an inorganic compound having a layered structure in which unit crystal layers are stacked on each other, and has a particle size of 5 μm or less in a cleaved state and an aspect ratio of 50 to 5,000 in gas barrier property ( More preferably, there is no particular limitation as long as the aspect ratio is in the range of 200 to 3000).

If the aspect ratio is less than 50, the gas barrier property is not sufficient, and if the aspect ratio is more than 5000, it is technically difficult and economically expensive. Further, when the particle size is 3 μm or less, the transparency becomes better, and when the particle size is 1 μm or less, it is more preferable for applications in which transparency is important.

Specific examples of the inorganic layered compound used in the present invention include graphite, phosphate derivative-type compounds (zirconium phosphate compounds, etc.), chalcogenides,
And clay minerals. Here, the “chalcogen compound” includes a group IV (Ti, Zr, Hf) and a group V (V,
Nb, Ta) and group VI (Mo, W) dichalcogenides represented by the formula MX2 (M is the above element and X is chalcogen (S, Se, Te)).

The particle size of the inorganic layered compound used in the present invention refers to a particle size obtained by a diffraction / scattering method in a dispersion medium. Although it is extremely difficult to measure the true particle size in the layer 3 composed of the resin composition, the layer composed of the resin composition is sufficiently swelled and cleaved with the same dispersion medium as that used in the diffraction / scattering method. In the case of compounding with the resin used in No. 3, the particle size of the unit crystal layer 31 which is the cleaved inorganic layered compound in the resin 32 in the layer 3 composed of the resin composition shown in FIG. This can be considered to correspond to the particle size of the unit crystal layer which is a layered compound.

(Method of Determining Average Particle Diameter) The method of determining the average particle diameter of particles in a liquid includes a method based on a diffraction / scattering method, a method based on a dynamic light scattering method, a method based on a change in electric resistance, and after photographing in a liquid microscope. A method by image processing or the like is possible.

In the dynamic light scattering method, when the resin and the particles coexist, the apparent liquid viscosity is different from that of a pure dispersion medium, so it is difficult to evaluate the method. There is a problem of resolution in the method using image processing after photographing in a submerged microscope, and each method is difficult to use.

In the method based on the diffraction / scattering method, when a resin solution, for example, an aqueous resin solution, has substantially little scattering (transparency), and therefore the scattering derived from particles is dominant, it can be performed regardless of the presence or absence of the resin. This is preferable because information on only the particle size distribution of the particles can be obtained.

(Measurement of Average Particle Size by Diffraction / Scattering Method) The measurement of particle size distribution and average particle size by the diffraction / scattering method is based on a method in which a dispersion obtained by dispersing a swollen and cleaved inorganic layered compound in an aqueous dispersion medium is subjected to light irradiation. The diffraction / scattering pattern obtained when the light is allowed to pass through is calculated by using the Mie scattering theory or the like to calculate the most consistent particle size distribution of the pattern.

As a commercially available device, a particle size measuring device (LS230, LS200, L
S100, manufactured by Coulter Co., Ltd.), laser diffraction particle size distribution analyzer (SALD2000, SALD2000A, S
ALD3000, manufactured by Shimadzu Corporation) Laser diffraction / scattering type particle size distribution analyzer (LA910, LA700, LA5)
00, manufactured by Horiba and Microtrack SP
A, Microtrack FRA, manufactured by Nikkiso Co., Ltd.).

(Method of Measuring Aspect Ratio) The aspect ratio (Z) is a ratio obtained from the relationship of Z = L / a. Here, L is the particle size (volume-based median diameter) of the inorganic layered compound in the dispersion obtained by the particle size measurement method by the above-mentioned diffraction / scattering method, and a is the cleaved unit shown in FIG. This is the unit thickness of the crystal layer 31. The “unit thickness a” is a value determined based on a result of independently measuring the thickness of the unit crystal layer in the inorganic layered compound by a powder X-ray analysis method described later or the like.

More specifically, as schematically shown in the graph of FIG. 3 in which the horizontal axis represents 2θ and the vertical axis represents the intensity of the X-ray diffraction peak, the lowest angle side of the observed diffraction peaks is shown. From the angle θ corresponding to the peak, the Bragg equation (nλ = 2Dsi
The interval determined based on nθ, n = 1, 2, 3,... is defined as “unit thickness a” (for details of the powder X-ray analysis method, see, for example, Jiro Shiokawa, “Guidance on Instrumental Analysis” (A), p. 69 (1985) published by Kagaku Doujinsha).

When the resin composition corresponding to the layer 3 composed of the resin composition obtained by removing the dispersion medium from the dispersion is subjected to powder X-ray analysis, it is usually necessary to disperse each of the inorganic layered compounds dispersed in the resin composition. Can be obtained as the surface distance d shown in FIG.

More specifically, as shown in the graph of FIG. 4 in which the horizontal axis indicates 2θ and the vertical axis indicates the intensity of the X-ray diffraction peak, the diffraction corresponding to the above “unit thickness a” is shown. Among diffraction peaks observed at a lower angle (larger interval) than the peak position, an interval corresponding to the peak at the lowest angle is defined as “plane interval d” (a <d).

As schematically shown in the graph of FIG. 5, when it is difficult to detect the peak corresponding to the above-mentioned "surface distance d" by overlapping with the halo (or background), the lower angle side than 2θd is detected. The area of the portion excluding the base line is set as a peak corresponding to the “surface distance d”. Here, “θd” is a diffraction angle corresponding to “(unit thickness a) + (width of single resin chain)”. (For details of the method of calculating the surface distance d, see, for example, Shuichi Iwata et al. Ed., "Encyclopedia of Clay", p. 35 and below and p. 271 and below, 1985,
(See Asakura Shoten Co., Ltd.)

Normally, the difference between the above-mentioned surface distance d and “unit thickness a”, that is, the value of k = (da) (when converted to “length”) constitutes the resin composition. It is equal to or greater than the width of a single resin chain [k = (da) ≧ width of a single resin chain]. Such “the width of a single resin chain” can be obtained by simulation calculation or the like (for example, “Introduction to Polymer Chemistry”, pp. 103-110, 198).
One year, see Doujin Kagaku) and polyvinyl alcohol (hereinafter abbreviated as PVA) in the case of 4 to 5 angstroms (2 to 3 angstroms of water molecules).

Unit crystal layer 3 in layer 3 made of resin composition
The "true aspect ratio" of 1 is very difficult to measure directly. The above aspect ratio Z = L / a is not necessarily
The “true aspect ratio” is not always equal to the “true aspect ratio” of the unit crystal layer 31 in the layer 3 made of the resin composition for the following reason.
It is valid to approximate

There is a relation of a <d between the spacing d obtained by the powder X-ray analysis of the resin composition and the “unit thickness a” obtained by the powder X-ray analysis of the inorganic layered compound alone. And the value of (da) is the value of resin 1 in the composition.
If the width of the main chain or more, in the resin composition,
The resin is inserted between the layers of each inorganic layered compound. Therefore, approximating the thickness of the unit crystal layer 31 in the layer 3 made of the resin composition by the above “unit thickness a”,
That is, it is sufficiently valid to approximate the “true aspect ratio” of the unit crystal layer 31 in the layer 3 made of the resin composition with the “aspect ratio Z” in the dispersion of the inorganic layered compound. is there.

As described above, the layer 3 composed of the resin composition
Although it is extremely difficult to measure the true particle size of the unit crystal layer 31 in the inside, the particle size of the unit crystal layer 31 in the resin 32 of the layer 3 composed of the resin composition is determined in the dispersion liquid (resin / inorganic layer form). This can be considered to correspond to the particle size L of the unit crystal layer in the inorganic layered compound (compound / dispersion medium).

However, the particle size L in the dispersion obtained by the diffraction / scattering method is considered to be very unlikely to exceed the major axis Lmax of the inorganic layered compound, so that the true aspect ratio (Lmax / a) is low. The possibility that the ratio is lower than the “aspect ratio Z” used in the present invention (Lmax / a <Z) is theoretically considerably low.

From the above two points, it is considered that the definition Z of the aspect ratio used in the present invention has sufficient validity. In the present specification, “aspect ratio” or “particle size” means “aspect ratio Z” defined above or “particle size L determined by a diffraction / scattering method”.

From the viewpoint of easily giving a large aspect ratio, an inorganic layered compound having a property of swelling and cleaving in a dispersion medium is preferably used.

The degree of the “swelling / cleaving property” of the inorganic layered compound used in the present invention in the dispersion medium can be evaluated by the following “swelling / cleaving test”. The swellability of the inorganic layered compound is preferably about 5 or more (more preferably, about 20 or more) in a swelling test described below. On the other hand, the cleavage property of the inorganic layered compound is preferably about 5 or more (and more preferably about 20 or more) in the cleavage test. In these cases, a liquid having a density smaller than the density of the inorganic layered compound is used as the dispersion medium. When the inorganic layered compound is a natural swellable clay mineral, it is preferable to use water as a dispersion medium.

<Swelling test> 100 mL of the dispersion medium was placed in a 100 mL measuring cylinder, and 2 g of the inorganic layered compound was added thereto.
Add slowly. The volume (mL) of the inorganic layered compound dispersed layer is read as the swelling value from the scale at the interface between the inorganic layered compound dispersed layer and the supernatant after standing at 23 ° C. for 24 hours. The larger the value, the higher the swelling property.

<Cleaving test> 30 g of an inorganic layered compound was slowly added to 1500 mL of a dispersion medium, and a dispersion machine [Despa MH-L, manufactured by Asada Tekko Co., Ltd., blade diameter 52 mm, rotation speed 3]
100 rpm, container capacity 3 L, distance 28 between bottom and blade
mm] at a peripheral speed of 8.5 m / sec for 90 minutes (23 ° C.), take 100 mL of the dispersion liquid, put it in a graduated cylinder and let stand for 60 minutes, and then, from the interface with the supernatant, the volume of the inorganic layered compound dispersed layer Read (mL) as cleavage value.

As the inorganic layered compound which swells and cleaves in the dispersion medium, a clay mineral which swells and cleaves in the dispersion medium is particularly preferably used. Such clay minerals are generally
A type having a two-layer structure having an octahedral layer having aluminum or magnesium as a central metal on the upper surface of a tetrahedral layer of silica, and an octahedral layer having a tetrahedral layer of silica having aluminum or magnesium as a central metal. Is classified into a type having a three-layer structure in which is narrowed from both sides. The former two-layer structure type includes kaolinite group and antigolite group, and the latter three-layer structure type includes smectite group, vermiculite group and mica group depending on the number of interlayer cations. Can be.

As these clay minerals, more specifically, kaolinite, dickite, nacrite, halloysite, antigolite, chrysotile, pyrophyllite, montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, hectite Light, tetrasilyl mica, sodium teniolite, muscovite, margarite, talc, vermiculite, phlogopite, zansophyllite, chlorite and the like can be mentioned.

A clay mineral treated with an organic substance (hereinafter sometimes referred to as an organic modified clay mineral) can also be used as an inorganic layered compound. (Note that a clay mineral treated with an organic substance is published by Asakura Shoten. See Clay Encyclopedia).

Among the above clay minerals, smectites, vermiculites and micas are preferred from the viewpoint of swelling or cleavage, more preferably smectites. Examples of the smectite group include montmorillonite, beidellite, nontronite, saponite, sauconite, stevensite, and hectorite.

As a dispersion medium for swelling or cleaving the inorganic layered compound, for example, in the case of a natural swelling clay mineral, water, alcohols such as methanol, ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol, dimethylformamide, dimethyl sulfoxide, Acetone and the like are mentioned, and alcohols such as water and methanol are more preferable.

In the case of organically modified clay minerals, aromatic hydrocarbons such as benzene, toluene and xylene; ethers such as ethyl ether and tetrahydrofuran; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; n-pentane; aliphatic hydrocarbons such as n-hexane and n-octane, chlorobenzene, carbon tetrachloride,
Chloroform, dichloromethane, 1,2-dichloroethane,
Examples include halogenated hydrocarbons such as perchlorethylene, ethyl acetate, methyl methacrylate (MMA), dioctyl phthalate (DOP), dimethylformamide, dimethyl sulfoxide, methyl cellosolve, and silicone oil.

In the layer 3 comprising the resin composition of the present invention, the above-mentioned high hydrogen bonding resin having a high content of a hydrogen bonding group or an ionic group is desirably used as the resin. The above-mentioned high hydrogen bonding resin means that the content of the hydrogen bonding group or the ionic group in the high hydrogen bonding resin (when both are contained, the total amount of both) is 20 to 60 mol% (preferably 30 to 60 mol%). 50 mol%). The content of these hydrogen bonding groups and ionic groups can be measured, for example, by a nuclear magnetic resonance (NMR) technique (1H-NMR, 13C-NMR, etc.).

The above-mentioned hydrogen bonding group includes a hydroxyl group, an amino group, a thiol group, a carboxyl group, a sulfonic acid group,
Examples of the ionic group include a carboxylate group, a sulfonate ion group, a phosphate ion group, an ammonium group, and a phosphonium group. Among the hydrogen bonding groups or ionic groups, more preferred are a hydroxyl group, an amino group, a carboxyl group, a sulfonic acid group, a carboxylate group, a sulfonic acid ionic group, an ammonium group and the like.

Specific examples of the high hydrogen bonding resin include, for example, PVA, ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 40 mol% or more, polysaccharides, polyacrylic acid and its esters, and polyacrylic acid. Sodium, polystyrene sulfonic acid, sodium polystyrene sulfonate, polyethylene imine, polyallylamine and its quaternary ammonium salt, polyvinyl thiol,
And polyglycerin. Among the above-mentioned resins, more preferable ones include PVA, polysaccharide, and ethylene-vinyl alcohol copolymer.

Here, PVA is a polymer obtained by, for example, hydrolyzing or transesterifying (saponifying) an acetic acid ester portion of a vinyl acetate polymer (that is, a polymer obtained as a copolymer of vinyl alcohol and vinyl acetate). )
Polymers obtained by saponifying a vinyl trifluoroacetate polymer, a vinyl formate polymer, a vinyl pivalate polymer, a tert-butyl vinyl ether polymer, a trimethylsilyl vinyl ether polymer, etc. (for details of PVA, for example, Povar Ed., "The World of PVA", 1992, Polymer Publishing Association; see Nagano et al., "Poval", 1981, Polymer Publishing Association).

The degree of "saponification" in PVA is preferably at least 70% by mole percentage, more preferably at least 85%, particularly preferably 98% or more, that is, a completely saponified product. The degree of polymerization in PVA is 100
It is preferably from 5000 to 5,000, more preferably from 200 to 3,000. Further, the PVA referred to in the present invention may be modified with a small amount of a copolymer monomer as long as the object of the present invention is not hindered.

The polysaccharide is a biopolymer synthesized in a biological system by polycondensation of various monosaccharides, and here includes those chemically modified based on them. Examples include cellulose and cellulose derivatives such as hydroxymethylcellulose, hydroxyethylcellulose and carboxymethylcellulose, amylose, amylopectin, pullulan, curdlan, xanthan, chitin, chitosan and the like.

The ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) has a vinyl alcohol content of from 40 mol% to 80 mol%, more preferably from 45 mol% to 75 mol%. EVOH. The melt index of EVOH (value measured under the conditions of temperature 190 ° C. and load 2160 g;
Is not particularly limited, but is 0.1 to 50 g / 1.
0 minutes is preferred. Further, the EVOH referred to in the present invention may be modified with a small amount of a comonomer as long as the object of the present invention is not hindered.

The above-mentioned modified polyvinyl alcohol and ethylene-vinyl alcohol copolymer refers to other unsaturated monomers copolymerizable with a vinyl acetate monomer in a vinyl ester resin during the production of polyvinyl alcohol, for example, Olefins such as ethylene, propylene, α-hexene and α-octene; unsaturated acids such as (meth) acrylic acid, crotonic acid, (anhydride) maleic acid, fumaric acid and itaconic acid, and alkyl esters and alkalis thereof. Salts, vinyl sulfonic acid, styrene sulfonic acid, 2-
Sulfonic acid-containing monomers such as acrylamide-2-methylpropanesulfonic acid and alkali salts thereof, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and trimethyl-2-(-
1- (meth) acrylamide-1,1-dimethylethyl) ammonium chloride, trimethyl-3- (1-
(Meth) acrylamidopropyl) ammonium chloride, 1-vinyl-2-ethylimidazole, other quaternizable cationic monomers, styrene, alkyl vinyl ether, (meth) acrylamide, and others.

The proportion of these copolymer components is not particularly limited, but may be 50 to vinyl alcohol units.
Mol% or less, preferably 30 mol% or less, and the form of copolymerization is random copolymerization,
Various forms obtained by an arbitrary method such as block copolymerization and graft copolymerization are used.

Among these copolymers, a block copolymer in which a polycarboxylic acid component is copolymerized with a polyvinyl alcohol component is particularly preferably used. In the case where the polycarboxylic acid component is polymethacrylic acid, Particularly preferred. Further, the block copolymer is particularly preferably an AB block copolymer in which a polyacrylic acid chain is extended at one end of a polyvinyl alcohol chain, and the polyvinyl alcohol block component (a) Weight ratio of acrylic acid block component (b) (a) /
(B) is preferably 50/50 to 95/5,
In the case where the ratio is 60/40 to 90/10, particularly preferable gas barrier properties are achieved, and the bonding characteristics with the substrate layer are remarkably excellent. Further, among other modified forms, one particularly preferred form is a silyl group-modified polyvinyl alcohol resin composed of a saponified vinyl ester polymer modified with at least one compound having a silyl group in the molecule. is there.

A method for obtaining a modified polymer having such a composition is not particularly limited, but a compound having a silyl group in a molecule is reacted with a vinyl alcohol-based polymer such as polyvinyl alcohol or modified polyvinyl acetate obtained by a conventional method. To introduce a silyl group into the polymer, or to activate an end of polyvinyl alcohol or a modified product thereof to introduce an unsaturated monomer having a silyl group in the molecule to the end of the polymer. Various modification methods such as a method of graft-copolymerizing a saturated monomer to a vinyl alcohol-based polymer molecular chain, a copolymer from a vinyl ester-based monomer and an unsaturated monomer having a silyl group in the molecule. And then saponifying it, or polymerizing a vinyl ester in the presence of a silyl group-containing mercaptan, etc. Various methods such as a method for introducing a silyl-terminated such as reduction are effectively used.

As the modified polyvinyl alcohol-based resin obtained by such various methods, any resin having a silyl group in the molecule may be used as a result. The silyl group contained in the molecule may be an alkoxyl group or a silyl group. Those having a reactive substituent such as an acyloxyl group and a hydrolyzate of a silanol group or a salt thereof are preferable, and among them, a silanol group is particularly preferable.

Compounds having a silyl group in the molecule used for obtaining these modified polyvinyl alcohol resins include trimethylchlorosilane, dimethylchlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane and triethylfluorosilane. Organohalosilanes such as silane, organosilicon esters such as trimethylacetoxysilane and dimethyldiacetoxysilane, organoalkoxysilanes such as trimethylmethoxysilane and dimethyldimethoxysilane,
Examples include organosilanols such as trimethylsilanol and diethylsilanediol, aminoalkylsilanes such as N-amiethyltrimethoxysilane, and organosilicon isocyanates such as trimethylsiliconisocyanate. The degree of modification by these silylating agents can be arbitrarily adjusted depending on the type, amount and reaction conditions of the silylating agent used.

The unsaturated monomer used in the method for saponifying a copolymer of a vinyl ester monomer and an unsaturated monomer having a silyl group in the molecule is vinyltrimethoxysilane. Many vinylsilane-based compounds such as vinylalkoxysilane and vinylmethyldimethoxysilane represented by vinyltriethoxysilane, and alkyl- or allyl-substituted vinylalkoxysilane represented by vinyltriisopropoxysilane; Further, polyalkylene glycol-modified vinyl silanes in which a part or all of these alkoxy groups are substituted with a polyalkylene glycol such as polyethylene glycol can be given. Furthermore, 3- (meth) acrylamino-propyltrimethoxysilane, 3
(Meth) acrylamide-alkylsilane represented by-(meth) acrylamide-propyltriethoxysilane and the like can also be preferably used.

On the other hand, a method in which a vinyl ester is polymerized in the presence of a mercaptan having a silyl group or the like and then saponified to introduce a silyl group to a terminal is described by an alkoxysilylalkyl such as 3- (trimethoxysilyl) -propylmercaptan. Mercaptan is preferably used.

The suitable range varies depending on the degree of modification of the modified polyvinyl alcohol-based resin of the present invention, that is, the content of the silyl group, the degree of saponification, etc., but it is an important factor for the gas barrier property which is the object of the present invention. Becomes
The content of the silyl group is usually 30 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less, as a monomer containing a silyl group, based on the vinyl alcohol unit in the polymer. And 2 mol% or less is particularly preferably used. The lower limit is not particularly limited, but 0.1 mol%
The effect is particularly remarkably exhibited in the above case.

The silylation rate indicates the ratio of the silyl group introduced after the silylation to the amount of the hydroxyl group contained in the polyvinyl alcohol resin before the silylation.

The modified polyvinyl alcohol-based resin into which the silyl group has been introduced is alcohol or alcohol /
By heating and dissolving with a mixed solvent of water, the compound is dissolved in an alcohol solvent due to the presence of the introduced silyl group.
On the other hand, the modified polyvinyl alcohol-based resin dissolved in the solvent is cross-linked by a part of the introduced silyl group reacting by a dealcoholization reaction and a dehydration reaction. In addition,
The presence of water is essential for the above reaction, and it is preferable to use a mixed solvent of alcohol / water.

These various polyvinyl alcohol-based resins may of course be used alone. However, as long as the object of the present invention is not impaired, they may be used as copolymers with other copolymerizable monomers or mixed with other monomers. It can be used in combination with other possible resin compounds. Examples of such a resin include polyacrylic acid or esters thereof, polyester resin, polyurethane resin, polyamide resin, epoxy resin, melamine resin, and others.

The coating liquid used in the present invention is a liquid obtained by dispersing or dissolving the above-mentioned inorganic layer compound and resin in a dispersion medium. From the viewpoint of the gas barrier properties of the obtained laminated film for retort sterilization packaging, the dispersion medium is preferably a liquid that swells or cleaves the above-described inorganic layered compound.

The composition ratio of the inorganic layer compound to the resin in the coating liquid is not particularly limited, but generally, the weight ratio of the inorganic layer compound to the resin (inorganic layer compound / resin) is 1%.
It is preferably in the range of / 100 to 100/1, more preferably 1/20 to 10/1. The higher the weight ratio of the inorganic layered compound is, the more excellent the gas barrier property is, but in consideration of the bending resistance, the range of 1/20 to 2/1 is more preferable. Also,
The concentration of the inorganic layered compound and the resin in the coating liquid is 0.1 to 70% by weight in total, 1 to 15% by weight from the viewpoint of productivity, and more preferably 4 to 10% by weight. .

When the resin used for the layer 3 comprising the resin composition of the present invention is a high hydrogen bonding resin, the crosslinking agent for a hydrogen bonding group is used for the purpose of improving the water resistance of the layer 3 comprising the resin composition. Can be used.

Preferred examples of the crosslinking agent include coupling agents such as titanium coupling agents, silane coupling agents, melamine coupling agents, epoxy coupling agents, isocyanate coupling agents, and the like. Epoxy compounds, copper compounds, zirconium compounds, organometallic compounds and the like can be mentioned. From the viewpoint of improving water resistance, organometallic compounds, zirconium compounds, water-soluble epoxy compounds, silane coupling agents are more preferably used,
More preferably, it is an organic metal compound such as an organic titanium compound.

Specific examples of the zirconium compounds include zirconium halides such as zirconium oxychloride, zirconium hydroxychloride, zirconium tetrachloride and zirconium bromide; and mineral acids such as zirconium sulfate, basic zirconium sulfate and zirconium nitrate. Zirconium salts of organic acids such as zirconium formate, zirconium acetate, zirconium propionate, zirconium caprylate and zirconium stearate;
Examples include zirconium complex salts such as ammonium zirconium carbonate, sodium zirconium sulfate, ammonium zirconium acetate, sodium zirconium oxalate, sodium zirconium citrate, and zirconium ammonium citrate.

Specific examples of the water-soluble epoxy compound include sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, glycidyl ether epoxy resin, heterocyclic epoxy resin, glycidylamine epoxy resin, and aliphatic epoxy resin. I can give it.

Examples of the silane coupling agent include amino silane coupling agents, vinyl or methacryloxy silane coupling agents, epoxy silane coupling agents, methyl silane coupling agents, and the like.
Chloro silane coupling agents and mercapto silane coupling agent systems are exemplified.

Preferable examples of the crosslinking agent for a hydrogen-bonding group include a reaction for forming a cross-linked structure by reacting with a plurality of functional groups of a high hydrogen-bonding resin, that is, an organometallic compound capable of a cross-linking reaction. For example, the above-mentioned organometallic compounds which react with a plurality of hydroxyl groups of polyvinyl alcohol and form a cross-linking by a coordination bond or an ionic bond between a metal atom of the organometallic compound and an oxygen atom of the hydroxyl group are preferable.

The above-mentioned organometallic compounds capable of undergoing a crosslinking reaction include:
Higher crosslinking reactivity and higher crosslinking efficiency than inorganic metal salts. However, if the cross-linking reactivity is too high, the cross-linking reaction proceeds in the coating solution and coating (coating) becomes impossible, but the cross-linking reactivity of the organometallic compound can be changed by appropriately changing the ligand. Easy to control. The organic metal compound is also superior to the inorganic metal salt in that it has the advantage that the reactivity is easily controlled. Among the organometallic compounds, an organometallic compound having a chelating ligand such as acetylacetonate has an appropriate crosslinking reactivity and is preferable as a crosslinking agent for a hydrogen bonding group.

Preferred examples of such organometallic compounds include organic titanium compounds, organic zirconium compounds, organic aluminum compounds and organic silicon compounds.

Specific examples of the organic titanium compound include titanium orthoesters such as tetranormal butyl titanate, tetraisopropyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, and tetramethyl titanate; titanium acetylacetonate;
Titanium chelates such as titanium tetraacetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate, titanium triethanolamine, titanium ethyl acetoacetate, and titanium acylates such as polyhydroxytitanium stearate. No.

Specific examples of the organic zirconium compound include zirconium normal propylate, zirconium normal butyrate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zirconium bisacetylacetonate, zirconium acetylacetonate bisethylacetoacetate and the like. No.

Specific examples of the organoaluminum compound include aluminum acetylacetonate, aluminum organic acid chelate and the like. Examples of the organic silicon compound include a silicon compound having a ligand included in the compounds exemplified as the organic titanium compound or the organic zirconium compound.

Among these, a chelate compound is preferred in terms of stability in a coating solution. In terms of the stability of the coating solution, the stability is greatly improved by setting the coating solution to be acidic. The above acidic conditions include a pH of 5
Or less, more preferably pH 3 or less. There is no particular lower limit on the pH of the coating solution, but usually the pH is 0.1.
5 or more. As the addition method, it is preferable to dilute with an alcohol and add. By including the step of mixing the above resin and a crosslinking agent, it is possible to obtain the layer 3 composed of the resin composition in which the above resin is crosslinked.

The amount of the crosslinking agent to be added is not particularly limited, but the ratio K (K = CN / HN) of the number of moles of the crosslinking group (CN) of the crosslinking agent to the number of moles of the hydrogen bonding group (HN) of the resin But,
It is preferable to use it in the range of 0.001 or more and 10 or less. More preferably, the molar ratio K is in the range of 0.01 or more and 1 or less.

The method of compounding or producing the resin composition comprising the above-mentioned inorganic layered compound and resin is not particularly limited.
From the viewpoint of uniformity or ease of operation during compounding, for example,
A method in which a liquid in which a resin is dissolved in a solvent and a dispersion in which the inorganic layered compound has been swollen and cleaved in advance with a dispersion medium are mixed, and then the solvent and the dispersion medium are removed (method 1). The inorganic layered compound is swollen with the dispersion medium A method of mixing the cleaved dispersion liquid with a resin, dissolving the resin in a dispersion medium, and then removing the dispersion medium (method 2), adding an inorganic layered compound to a liquid in which the resin is dissolved in a solvent. A method of swelling and cleaving the inorganic layered compound using the solvent as a dispersion medium to form a dispersion and removing the solvent (method 3), or a method of hot-kneading the resin and the inorganic layered compound (method 4) can be used. It is. From the point that a large aspect ratio of the inorganic layered compound can be easily obtained,
The former three methods are preferably used. In the former three cases, it is preferable to perform treatment using a high-pressure dispersion device from the viewpoint of dispersibility of the inorganic layered compound.

As a high-pressure dispersion device, for example, Microfluid
There is an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by ics Corporation or a Nanomizer manufactured by Nanomizer, and a homogenizer manufactured by Manton-Gaulin, such as a homogenizer manufactured by Izumi Food Machinery.

In the above three methods, after removing the solvent and the dispersion medium from the system and laminating, the obtained film laminate for retort sterilization packaging is heated to, for example, 110 ° C. to 220 ° C.
The following heat aging is preferable because the water resistance (meaning of gas barrier properties after the water resistance environment test) of the film laminate for retort sterilization packaging can be particularly improved.

The aging time is not limited, but it is necessary that the film laminate for retort sterilization packaging reaches at least a set temperature. For example, in the case of a method using a hot medium such as a hot air drier, 1 second or more and 100 minutes or less Is preferred. There is no particular limitation on the heat source, and various methods such as heat roll contact, heat medium contact (air, oil, etc.), infrared heating, microwave heating, and the like can be applied. The aging treatment exhibits a particularly excellent effect in improving water resistance when the resin is a high hydrogen bonding resin.

In the present invention, the high-pressure dispersion treatment is performed, as shown in FIG. 6, by passing a composition mixture obtained by mixing particles to be dispersed or a dispersion medium and the like into a plurality of narrow tubes 11 at high speed to collide with each other. Dispersion treatment under special conditions such as high shear and high pressure.

In such a high-pressure dispersion treatment, the composition mixture is preferably passed through a thin tube 11 having a diameter of 1 μm to 1000 μm. When the composition mixture passes through the small tube 11, the maximum pressure condition is 100 kgf / cm ² or more is preferably applied, and further, 500 kgf / c
m2 or more, more preferably 1000 k
gf / cm ² or more. In addition, the composition mixture is a thin tube 1
When passing through 1, the maximum speed of the composition mixture is preferably 100 m / s or more, and the heat transfer speed is preferably 100 kcal / hr or more.

The principle of the high-pressure treatment in the high-pressure dispersion treatment apparatus used for the high-pressure dispersion treatment will be described schematically.
The composition mixture is sucked into the feeder tube 13 having a larger diameter than the thin tube 11 by the pump 12 and taken in. Subsequently, a high pressure is applied to the composition mixture in the feeder tube 13 by the pump 12. At this time, the composition mixture in the feeder tube 13 is supplied to the thin tube 11 by a check valve (not shown) provided in the feeder tube 13.
Extruded toward. Therefore, the composition mixture is in a high pressure and high speed state in the capillary 11, and the inorganic layer compound particles of the composition mixture collide with each other and the inner wall of the capillary 11, and the diameter and The thickness, in particular the thickness, is subdivided and more evenly distributed and is taken out of the discharge pipe 14 to the outside.

For example, when the flow velocity at the point where the maximum velocity is instantaneously reached with respect to the composition mixture as the processed sample in the thin tube 11 is 300 m / s, the volume is 1 × 10 ^−3.
When passing through a cube of m ³ at 1 / (3 × 10 ⁵ ) sec and the temperature of the composition mixture rises by 35 ° C., energy is transferred to the composition mixture by pressure loss. The heat transfer rate was such that the specific gravity of the composition mixture was 1 g / cm ³ , and the specific heat was 1 cal.
/ G ° C., 3.8 × 10 4 kcal / hr.

The layer 4 made of a stretched film is not particularly limited, but is preferably at least one selected from the group consisting of biaxially stretched polyamide and biaxially stretched polyethylene terephthalate. As the layer 4 composed of the above-mentioned stretched film, the one having a higher tensile strength is more preferable, and the elongation at break is preferably 700% or less, more preferably 500% or less. Examples of the polyamide-based biaxially stretched film include nylon-6, nylon-6,6, metaxylenediamine-adipic acid condensation polymer, and the like. The layer 4 composed of a stretched film may have a metal or metal oxide deposited thereon, and such a deposited layer is preferably provided on stretched polyethylene terephthalate.

In laminating the layer 3 composed of the resin composition on the layer 1 composed of the substrate film, the substrate film is subjected to surface treatment, for example, corona treatment, flame plasma treatment, ozone treatment, electron beam irradiation treatment, anchor treatment. May be performed.

When the anchor treatment is performed, for example, as shown in FIG. 7, when the anchor layer 2 is formed on the base film, the material of the anchor layer 2 may be, for example, polyethyleneimine, alkyl titanate, polybutadiene,
The urethane-based anchor layer 2 prepared from an isocyanate compound and an active hydrogen compound is preferable from the viewpoint of water resistance, although it is not particularly limited.

The isocyanate compounds include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), and hexamethylene diisocyanate (HDI).
I), 4,4'-methylenebiscyclohexyl isocyanate (H12MDI), isophorone diisocyanate (IP
DI).

The active hydrogen compound may be any compound having a functional group capable of binding to an isocyanate compound.
For example, ethylene glycol, diethylene glycol,
Low molecular weight polyols such as dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, polyethylene glycol, polyoxypropylene glycol, ethylene oxide / propylene oxide copolymer, polytetramethylene Examples include polyether polyols such as ether glycol, poly-β-methyl-δ-valerolactone, polycaprolactone, and polyester polyols such as polyester from diol / dibasic acid.

In the active hydrogen compound, a low molecular weight polyol is particularly preferable, and a diol in the low molecular weight polyol is more preferable. Here, diols are ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, etc., and the dibasic acids are adipic acid, azelaic acid, sebacic acid, and isophthalic acid. And terephthalic acid. Other polyols include castor oil, liquid polybutadiene, epoxy resin, polycarbonate diol, acrylic polyol, and active hydrogen compounds such as neoprene.

The mixing ratio between the isocyanate compound and the active hydrogen compound is not particularly limited, but it is preferable to determine the amount to be added in consideration of the equivalence relationship between the isocyanate group and the active hydrogen group, for example, —OH, —NH, and —COOH. . For example,
Ratio R (R = AN / B) between the number of moles of isocyanate groups (AN) and the number of moles of active hydrogen groups (BN) of the active hydrogen compound
N) is preferably 0.001 or more from the viewpoint of adhesive strength, and is preferably 10 or less from the viewpoint of tackiness and blocking. More preferably, the molar ratio R is in the range of 0.01 or more and 1 or less. 1H-NMR, 13C-NMR
Can be quantified by

The method of laminating the anchor layer 2 on the layer 3 composed of the resin composition or another layer, for example, the layer 1 composed of the base film, is not particularly limited, but an anchor coating agent containing an isocyanate compound and an active hydrogen compound Is dissolved in a solvent, and a coating method using an anchor coating agent solution is preferable.

Specific examples of the coating method include a roll coating method such as a direct gravure method, a reverse gravure method, a microgravure method, a two-roll beat coating method, a bottom feed three-reverse coating method, and a doctor knife method. Examples of the method include a die coating method, a dip coating method, a bar coating method, and a coating method combining these methods.

The solvent component in the anchor coating agent solution is mainly an organic solvent, and includes alcohols, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, esters, ketones, ethers, and the like. Halogenated hydrocarbons and mixed solvents thereof are exemplified.

The coating thickness obtained by applying the anchor coating agent solution in a film form is not particularly limited, but the dry thickness is 0.01 μm
It is preferable that the distance is set to be about 5 μm. The larger the coating thickness, the better the heat sealing strength, but the lower the gelboflex resistance. Therefore, the coating thickness is more preferably from 0.03 μm to 2.0 μm, and still more preferably from 0.05 μm to 1.0 μm.

The thickness of the layer 3 composed of the resin composition is in the range of 1 nm to 10 μm in dry thickness, more preferably 10 nm to 10 μm.
nm to 5 μm, more preferably 0.1 μm
１1 μm. If the thickness exceeds 10 μm, the flexibility of the obtained laminated film for retort sterilization packaging deteriorates. If the thickness is less than 1 nm, an effective gas barrier property cannot be obtained.

In the film laminate for sterilizing retort packaging of the present invention, the anchor layer 2, particularly the urethane anchor layer 2
In the case where is used, the layer 3 made of the resin composition desirably contains a surfactant for improving the adhesion to the anchor layer 2. As the surfactant, an anchor layer 2
The material is not particularly limited as long as it can improve the adhesion and adhesion between the resin composition and the layer 3 made of the resin composition.
Examples include anionic, cationic, zwitterionic and nonionic surfactants.

Examples of the anionic surfactant include a carboxylic acid type such as an aliphatic monocarboxylate, N-acyloylglutamate, an alkylbenzene sulfonate, a naphthalene sulfonate-formaldehyde condensate, and a dialkyl sulfosuccinate. Sulfonate type such as sulfonic acid type, alkyl sulfate salt, alkyl sulfate polyoxyethylene salt, etc., phosphate type such as alkyl phosphate salt, borate type such as alkyl borate salt, etc. Surfactants, fluorine-based anionic surfactants such as sodium perfluorodecanoate and sodium perfluorooctylsulfonate, and silicone-based anions having an anionic group such as a polymer having a polydimethylsiloxane group and a metal carboxylate. Surfactants.

Examples of the cationic surfactant include, for example,
Amine salt types such as alkylamine salts, alkyltrimethylammonium salts, dialkyldimethylammonium salts,
A quaternary ammonium salt type such as an alkyldimethylbenzylammonium salt is exemplified.

Examples of zwitterionic surfactants include carboxybetaine type such as N, N-dimethyl-N-alkylaminoacetic acid betaine, and glycine such as 1-alkyl-1-hydroxyethyl-1-carboxymethylimidazolinium betaine. Type.

Examples of the nonionic surfactant include ester types such as glycerin fatty acid ester, sorbitan fatty acid ester and sucrose fatty acid ester, condensation polymers of polydimethylsiloxane groups and alkylene oxide adducts, and polysiloxane-polyoxyalkylenes. Ether type such as copolymer, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene block polymer, etc., ester ether type such as polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, etc., aliphatic alkanol Examples thereof include alkanolamide type such as amide and fluorine type such as diglycerin ester of perfluorodecanoic acid and perfluoroalkylalkylene oxide compound.

Among the above surfactants, in particular, those having 6 carbon atoms
An alkali metal salt of a carboxylic acid having an alkyl chain of not more than 24 or less, an ether type nonionic surfactant such as polydimethylsiloxane-polyoxyethylene copolymer (silicone nonionic surfactant), Fluorinated nonionic surfactants such as alkyl ethylene oxide compounds (fluorinated nonionic surfactants)
Is preferred.

When the layer 3 made of the resin composition is formed, for example, when a coating liquid is used, the amount of the surfactant is 0.001 to 5% by weight in the coating liquid from the viewpoint of the effect. Preferably, it is 0.003 to 0.5% by weight, more preferably 0.1 to 0.5% by weight.
005-0.1% by weight is particularly preferred.

In the present invention, layers other than those described above can be provided as long as the effect is not impaired. Each material of the film laminate for retort sterilization packaging includes an ultraviolet absorber, a coloring agent, an antioxidant and the like. Additives may be mixed.

In the case of the packaging bag provided with the above-mentioned film laminate for retort sterilization packaging, the shape of the container main body is such that the food can be packaged as an object to be packaged and the shape is particularly suitable as long as it is suitable for heating. Although not limited, a shape having autonomy is desirable.

The self-sustainability may be any shape as long as it can be placed on a horizontal place without any particular assistance without any assistance. For example, a cube, a rectangular parallelepiped, a column (drum), a truncated cone,
It is formed into a truncated pyramid shape.

Specific examples of the above shapes include three-side sealed packaging bags, four-side sealed packaging bags, pillow packaging bags, packaging bags with gussets, carton-shaped, brick-shaped, and standing pouch-shaped container bodies shown in FIG. The film laminate for retort sterilization packaging is formed such that the heat-sealable resin layer 6 becomes the innermost layer so as to be No. 8.

The thickness of the film laminate for sterilizing retort packaging in the above-mentioned packaging bag is not particularly limited, but is preferably 30 μm or more from the viewpoint of protection of the contents to be packaged and 300 μm or less from the viewpoint of cost. preferable.

Examples of the use of the packaging bag provided with the laminated film for sterilizing retort packaging of the present invention include confectionery, Western confectionery, miso,
Pickles, konjac, chikuwa, kamaboko, other processed fishery products, meatballs, hamburgers, ham and sausages, coffee, sake, sauces, seasonings, soups, curry roux,
Food fields such as food packaging applications such as prepared foods such as miso soup are preferred, but furthermore, temperature adjustment such as heating is required, cosmetics, aromatics, medical infusion packs, semiconductor packaging, It is also used in medical, electronic, chemical and mechanical fields, such as packaging of oxidizing chemicals such as developer and sodium hypochlorite, and packaging of precision materials.

[0130]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. The methods for measuring various physical properties are described below.

[Thickness Measurement] The thickness of 0.5 μm or more was measured with a commercially available digital thickness gauge (contact type thickness gauge, trade name: Ultra-high precision decimicro head MH-15M, manufactured by Nippon Kogaku Co., Ltd.). On the other hand, the thickness of less than 0.5 μm is determined by a gravimetric analysis method (the measured weight of a film having a certain area is divided by the area and further divided by the specific gravity of the composition) or the actual coating film thickness by the IR method. A calibration curve with IR absorption was prepared and determined from the calibration curve. Further, in the case of measuring the coating film thickness of the resin composition of the present invention, for example, the elemental analysis method (specific inorganic element analysis value of the laminate (derived from the layer composed of the resin composition) and the specific element fraction of the inorganic layered compound alone) Of determining the ratio of the layer composed of the resin composition of the present invention to the layer composed of the base material film from the ratio of (1).

[Measurement of Particle Size] Using a laser diffraction / scattering type particle size distribution analyzer (LA910, manufactured by HORIBA, Ltd.), a volume-based median of particles considered to be an inorganic layered compound present in the resin matrix of the medium. The diameter was measured as a particle diameter L. The undiluted liquid dispersion was measured with an optical path length of 50 μm in a paste cell, and the dilute liquid of the dispersion was measured with an optical path length of 4 mm by a flow cell method.

[Aspect Ratio Calculation] X-ray diffractometer (XD
-5A (manufactured by Shimadzu Corporation), the diffraction measurement of the inorganic layered compound alone and the resin composition by the powder method was performed. Thereby, the unit thickness a of the inorganic layered compound was determined, and further, from the diffraction measurement of the resin composition, it was confirmed that there was a portion where the plane interval of the inorganic layered compound was widened. Using the particle diameter L obtained by the above method, the aspect ratio Z was calculated by the equation of Z = L / a.

[Oxygen Permeability Measurement] Based on JIS K7126, an oxygen permeability measuring device (OX-TRAN ML,
MOCON) at 23.7 ° C (60% R
H).

[Heat Seal Test] The layers comprising the heat sealable film of the film laminate were subjected to
Using a hot peel tester, heat seal temperature 190 ℃,
Heat sealing was performed under the conditions of a pressure of 1.5 kg / cm 2 (actual pressure) and a time of 4 seconds, cut into a strip having a width of 15 mm, set on an autograph (AGS-100, manufactured by Shimadzu Corporation), and set at 300 mm / min. The heat seal strength was measured at the tensile speed.

[Gelboflex resistance test] ASTM
Based on F392, the obtained film laminate was
After aging for 24 hours in an environment of 50 ° C. and 50% RH,
The above film laminate held in a tubular shape was twisted by 440 ° with a center axis of the tubular shape as a rotation axis using a gelboflex tester with a thermostat (Tester Sangyo Co., Ltd.), and then returned to the original state. Repeated times.

[Loop stiffness test] As a measure of the waist of the film laminate, a loop stiffness was measured using a loop stiffness tester manufactured by Toyo Seiki Co., Ltd. under the conditions of a sample width of 10 mm and a sample length of 100 mm.

[Retort Test] A retort sterilization test was performed on a retort packaging bag produced using the obtained film laminate. The retort sterilization condition is 120
C., 2 kg / cm @ 2, for 30 minutes [Time oaker (high-speed hot water storage type sterilizer); manufactured by Sampras].

[Example 1] [Coating solution for layer composed of resin composition] In a dispersing vessel [trade name: Despa MH-L, manufactured by Asada Iron Works Co., Ltd.], ion-exchanged water (specific electric conductivity of 0.7) was added. μS / cm or less), and PVA [PVA117H; manufactured by Kuraray Co., Ltd.
Saponification degree: 99.6%, polymerization degree: 1700], and heated to 95 ° C. under low-speed stirring (1500 rpm, peripheral speed: 4.10 m / min), stirred for 1 hour, dissolved, and dissolved (A)
I got

Next, the solution (A) was stirred for 60 hours.
After lowering the temperature to 0 ° C., a solution obtained by adding 0.25 g of a nonionic surfactant (trade name: SH3746, manufactured by Dow Corning Toray Co., Ltd.) to a mixed solution of 125 g of 1-butanol and 375 g of isopropyl alcohol was added. The above solution (A)
To obtain a mixture (B). The nonionic surfactant is a polydimethylsiloxane-polyoxyethylene copolymer.

1960 g of the mixture (B) was charged into a stirring emulsifying apparatus (trade name: vacuum emulsifying apparatus PVQ-3UN, manufactured by Mizuho Industry Co., Ltd.). 50 g of natural montmorillonite (Kunipia F; manufactured by Kunimine Kogyo KK) was added as a powder so that the weight ratio of the resin to the inorganic layered compound was 2: 1 and it was confirmed that montmorillonite was substantially precipitated in the liquid. Thereafter, high-speed stirring was performed at 600 mmHg and 5000 rpm for 10 minutes to obtain a resin composition mixed solution (C).

A 2000 g of the resin composition mixture (C) was dispersed in a high-pressure dispersing apparatus (trade name: ultra-high pressure homogenizer M110-).
E / H, manufactured by Microfluidics Corporation), and treated once under a pressure condition of 1750 kgf / cm ² to obtain a uniform dispersion liquid (D) having good dispersibility. The solid content concentration of the dispersion (D) was 7.5% by weight.

The dispersion (D) comprising PVA and montmorillonite was cast into a film and subjected to X-ray analysis.
The interplanar spacing d of the swelled and cleaved montmorillonite (inorganic layered compound) was measured.

As a result of obtaining the plane distance d from the diffraction peak obtained from the X-ray analysis, the plane distance d was larger than the unit thickness a. Therefore, the montmorillonite was sufficiently cleaved for the reason described above. It turns out. The aspect ratio of the cleaved inorganic layered compound at this time was 200.
That was all.

The dispersion (D) was adjusted with hydrochloric acid so that the pH of the dispersion (D) was 3 or less under low-speed stirring (1500 rpm, peripheral speed 4.10 m / min). Titanium acetylacetonate [TC1
5.3, was gradually added to obtain a coating liquid for a layer composed of a resin composition.

[Film laminate for retort sterilization packaging] Biaxially stretched polyethylene terephthalate (O
PET) A film (Espet T4102, manufactured by Toyobo Co., Ltd.) that has been subjected to surface corona treatment is used as a layer composed of a base film, and an anchor coating agent (urethane-based) [Adcoat AD335 / C
AT10 = 15/1 (weight ratio): Toyo Morton Co., Ltd.
Gravure coating (test coater; manufactured by Yasui Seiki Co., Ltd .: microgravure coating method, coating speed 3 m / min, drying temperature 8)
0 ° C). The dry thickness of the anchor coat layer was 0.05 μm.

Next, a coating liquid for a layer comprising the resin composition was
Gravure coating (test coater; manufactured by Yasui Seiki Co., Ltd .: microgravure coating method, coating speed 3)
m / min at a drying temperature of 100 ° C.) to obtain a coating film in which a layer composed of a resin composition based on a layer coating solution composed of the above resin composition was formed on the anchor coat layer. The dry thickness of the layer composed of the resin composition was 0.5 μm.

Subsequently, an adhesive [Adcoat AD503 / CA] was applied to the layer comprising the resin composition of the coating film.
T10 = 15/1 (weight ratio): manufactured by Toyo Morton Co., Ltd.]
Using a 15 μm thick biaxially stretched nylon (biaxially stretched polyamide) film [Emblem (ON
BC-15)], followed by dry lamination of a two-layer CPP film (heat sealable film) having a thickness of 80 μm on a biaxially stretched nylon film to obtain a film laminate for retort sterilization packaging. . In the two-layer CPP film, the layer on the biaxially stretched nylon side has a thickness of 30 μm, and is a resin composed of 100 parts by weight of PP (propylene-ethylene block copolymer, MFR2) for highlet, 30 parts by weight of talc, and 6 parts by weight of titania. The remaining layer (heat-sealable resin layer) is a 50 μm-thick PP (propylene-
A layer comprising ethylene block copolymer (MFR2), and the heat-sealable resin layer is the outermost layer of the film laminate on the side opposite to the OPET film, and is the innermost layer when the package is formed. .

The obtained film laminate had light-shielding properties, had a loop stiffness of 7.0 g, and reduced the rigidity of the film laminate. The heat seal strength immediately after the retort treatment was 4.5 kg / 15 mm, and the oxygen permeability after the 100 times Gelboflex test was 0.4 cc / m ² · day · atm.

Example 2 In the same manner as in Example 1, using a biaxially stretched PET film having a resin composition film formed on its surface, an adhesive [Adcoat AD806 / CAT RT-8 = 15/1 (weight ratio): silica of a 12 μm-thick silica-deposited PET film [Tech Barrier T, manufactured by Mitsubishi Chemical Kojin Pax] using an adhesive for retort manufactured by Toyo Morton Co., Ltd. Dry lamination was performed with the vapor deposition surface facing to obtain a laminated film. Then, using the laminated film, a thickness of 80 μm
Was laminated by dry lamination to obtain a film laminate for retort sterilization packaging. In the two-layer CPP film, the layer on the side of the biaxially stretched nylon is 30 μm in thickness, and PP (propylene-ethylene block copolymer, MFR2) 100 for highlet.
Part of the resin composition consisting of 6 parts by weight of titania and the remaining layer (heat sealing resin layer) having a thickness of 5
It is a layer made of PP (propylene-ethylene block copolymer, MFR2) for 0 μm hight, and the heat-sealable resin layer is the outermost layer of the film laminate on the side opposite to the coated film. This is the layer that will be the innermost layer when done. The film laminate obtained above had a light-shielding property, had a loop stiffness of 7.5 g, and reduced waist shortage of the film laminate. The heat seal strength immediately after the retort treatment was 3.8 kg / 15 mm, and the oxygen permeability after the 100 times Gelboflex test was 0.2 cc / m ² · day · atm.

Example 3 A film laminate was obtained in the same manner as in Example 2, except that coating was performed on a biaxially stretched nylon film having a thickness of 15 μm instead of the biaxially stretched PET film. The obtained film laminate had a light-shielding property, had a loop stiffness of 8.0 g, and reduced the lack of waist of the film laminate. The heat seal strength immediately after the retort treatment was 3.7 kg / 15 mm, and the oxygen permeability after the 100 times Gelboflex test was 0.2 cc / m ² · day · atm.

[Comparative Example 1] Biaxial stretching P used in Example 1
The ET film and the biaxially stretched nylon film are dry-laminated, and the biaxial nylon film side is coated with the coating solution for the resin composition layer used in Example 1 in the same manner as in Example 1; On the side, PP for highlet used in Example 1
A CPP film (single layer) having a thickness of 80 μm was dry-laminated in the same manner as in Example 1 to obtain a film laminate.

The obtained film laminate had no light-shielding property, had a loop stiffness of 5.5 g, and had insufficient rigidity of the film laminate. The heat seal strength immediately after the retort treatment was 1.9 kg / 15 mm.

[0154]

As described above, the film laminate for retort sterilization packaging of the present invention comprises a layer comprising a base film, a layer comprising a resin composition having an inorganic layered compound, and a layer comprising a stretched film. This is a configuration in which layers made of a multilayer film having heat sealing properties are laminated on each other in this order.

Therefore, in the above-described structure, since the resin containing the inorganic layered compound enables the use of a resin containing no chlorine in the layer made of the resin composition, it is possible to use a conventional polyvinylidene chloride-based film layer. Compared to the case, disposal at the time of disposal and recycling can be facilitated.

Further, in the above configuration, a layer composed of a base film, a layer composed of a resin composition, a layer composed of a stretched film, and a layer composed of a multilayer film having heat sealing properties are provided in this order. By doing so, it is possible to reduce waist shortage and impart light-shielding properties, and it is possible to improve the protection of food contents by maintaining the heat seal strength after retort treatment.

As a result, the above-described structure is excellent in protection properties such as gas barrier properties against the packaged items such as food contents, and can facilitate disposal and recycling at the time of disposal.
This has the effect of improving the protection of food contents.

The packaging bag provided with the laminated film for retort sterilizing packaging according to the present invention can facilitate the processing and recycling at the time of disposal as described above, and has an improved protective property for food contents. By providing the laminate, the gas barrier property is similarly excellent, and the treatment and recycling at the time of disposal can be facilitated, and the effect of improving the protection of food contents is exhibited.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a film laminate for retort sterilization packaging of the present invention.

FIG. 2 is a schematic cross-sectional view showing a layer made of a resin composition in the film laminate for sterilizing retort packaging.

FIG. 3 is an X-ray diffraction graph of the inorganic layered compound for calculating “unit thickness a” of the inorganic layered compound in a layer made of the resin composition.

FIG. 4 is an X-ray diffraction graph of the inorganic layered compound for calculating the “plane spacing d” of the inorganic layered compound in a layer made of the resin composition.

FIG. 5 is a graph for calculating the “plane spacing d” of the inorganic layered compound in the case where it is difficult to detect the peak corresponding to the “plane spacing d” in the graph of FIG. 4 because of the overlap with a halo (or background). It is an X-ray diffraction graph at the time.

FIG. 6 is used when producing a layer made of the resin composition.
It is explanatory drawing which shows a high pressure dispersion process typically.

FIG. 7 is a schematic sectional view showing another example of the film laminate for retort sterilization packaging of the present invention.

FIG. 8 is a schematic perspective view showing an example of a packaging bag formed using the above-mentioned film laminate for sterilizing retort packaging.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 layer composed of base film 2 anchor layer 3 layer composed of resin composition 4 layer composed of stretched film 5 layer composed of heat sealable film 6 heat sealable resin layer 7 layer containing inorganic filler and / or light shielding agent 8 container body

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiya Kuroda 2-10-1, Tsukahara, Takatsuki-shi, Osaka Inside Sumika Plastics Tech Co., Ltd. (72) Taiichi Sakatani 2-1-1, Tsukahara, Takatsuki-shi, Osaka No. Sumika Plastics Co., Ltd. (72) Inventor Tadatoshi Ogawa 3-1-1 Higashiikebukuro, Toshima-ku, Tokyo Inside the New Energy and Industrial Technology Development Organization (72) Inventor Seto Okino 2-chome Tsukahara, Takatsuki-shi, Osaka No. 10-1 Sumika Plastics Tech Co., Ltd.

Claims (11)

[Claims] 1. A film in which a layer composed of a base film, a layer composed of a resin composition having an inorganic layered compound, a layer composed of a stretched film, and a layer composed of a heat-sealing film are laminated in this order. A laminate, wherein the heat-sealable film is a multilayer film having at least a heat-sealable resin layer and an inorganic filler and / or light-shielding agent-containing layer, wherein the heat-sealable resin layer is a layer comprising a base film; A film laminate for sterilizing retort packaging, which is the outermost layer on the opposite side. 2. The laminated film for retort sterilization packaging according to claim 1, wherein the stretched film is made of at least one selected from the group consisting of biaxially stretched polyamide and biaxially stretched polyethylene terephthalate. body. 3. The film laminate for retort sterilization packaging according to claim 1, wherein the inorganic layered compound has a property of expanding and cleaving in a dispersion medium. 4. The layer according to claim 1, wherein the layer comprising the resin composition is obtained by subjecting a mixture of the resin composition having an inorganic layered compound to a high-pressure dispersion treatment. 4. A film laminate for retort sterilization packaging according to any one of the above. 5. The high-pressure dispersion treatment is performed at 100 kgf / cm @ 2.
The film laminate for retort sterilization packaging according to claim 4, which is subjected to a dispersion treatment under the above pressure conditions. 6. An inorganic layered compound having an aspect ratio of 50 to 50.
The film laminate for retort sterilization packaging according to any one of claims 1 to 5, wherein the thickness is 5000. 7. The film laminate for retort sterilization packaging according to claim 1, further comprising a stretched film having a metal or metal oxide vapor deposited layer as the stretched film layer. 8. The layer comprising the resin composition contains a high hydrogen bonding resin, and the weight ratio of the inorganic layered compound to the high hydrogen bonding resin is in the range of (1/100) to (100/1). The film laminate for sterilizing retort packaging according to any one of claims 1 to 7, wherein: 9. The film laminate for retort sterilization packaging according to claim 8, wherein the high hydrogen bonding resin has 20% or more and 60% or less of hydrogen bonding groups or ionic groups. 10. The retort according to claim 8, wherein the high hydrogen bonding resin is polyvinyl alcohol and a modified product thereof, a polysaccharide, or an ethylene-vinyl alcohol copolymer and a modified product thereof. Film laminate for sterile packaging. 11. A packaging bag comprising the laminated film for retort sterilization packaging according to any one of claims 1 to 10 such that the heat-sealable resin layer is the innermost layer.