JPH106429A - Gas barrier laminated film or sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film equipped with excellent strength characteristics and gas barrier properties, not damaging gas barrier properties even after retort treatment or boiling treatment and suitably usable even in heat sealing. SOLUTION: A laminated film is constituted by forming a gas barrier layer composed of an inorg. vapor deposition layer on the single surface or both surfaces of a base layer constituted of a polyamide film and further forming a heat seal layer thereon. In this case, the compression modulus of elasticity of the heat seal layer at 40 deg.C is 10kgf/mm<2> or more and the shrinkage factors in respective directions of the laminated film are respectively 4.5% or less at a time of retort treatment at 120 deg.C for 30min and respectively 3.5% or less at a time of boiling treatment at 95 deg.C for 30min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has excellent gas barrier properties and moisture proof properties, which are important properties in packaging films for fresh foods, processed foods, pharmaceuticals, medical equipment, electronic parts, and the like, and excellent handling properties. It relates to a laminated resin film or sheet.

[0002]

2. Description of the Related Art In recent years, food packaging has been drastically changed due to changes in food distribution and eating habits, and the required characteristics of packaging films and sheets (hereinafter referred to as films) have become increasingly severe. Is coming.

[0003] Deterioration in product quality due to temperature changes, moisture, oxygen, ultraviolet rays, and microorganisms such as bacteria and mold in the distribution and sales process is a serious problem not only in terms of sales but also in terms of food hygiene. . As a method of preventing such quality deterioration, antioxidants and preservatives have been added directly to foods in the past, but in recent years regulations on food additives have become stricter from the standpoint of consumer protection. Is required to be reduced or not added. Under such circumstances, there is an increasing demand for packaging films that have low gas and moisture permeability and do not cause deterioration in quality as food even by freezing, boiling, retorting and the like.

That is, in the packaging of fish meat, animal meat, shellfish and the like, it is important to suppress the oxidation and deterioration of proteins and fats and oils, and to maintain taste and freshness. For this purpose, packaging materials having good gas barrier properties are required. It is desired to block the permeation of air by using a. Moreover, if wrapped in a gas barrier film,
Since the aroma of the contents is retained and the permeation of water is prevented, the moisture absorption of dried products is suppressed, and the deterioration and solidification of water-containing products due to evaporation of water are suppressed. It can be held for a long time.

For these reasons, kneaded products such as kamaboko, dairy products such as butter and cheese, miso, tea, coffee,
Gas barrier properties and moisture resistance required for packaging films of confectionery such as hams and sausages, instant foods, castella, biscuits and the like are regarded as extremely important properties.
These properties are not limited to food packaging films as described above, but also for medical products that need to be handled under aseptic conditions and packaging films for electronic components that require rust prevention. It is extremely important.

As a film having excellent gas barrier properties,
Known are those in which a metal such as aluminum is laminated on a plastic film, and those in which vinylidene chloride or an ethylene vinyl alcohol copolymer is coated. Further, as a device using an inorganic thin film other than a metal, a device in which silicon oxide, aluminum oxide, or the like is laminated is also known.

[0007]

The following problems have been pointed out in the conventional gas barrier films as described above. As a gas barrier layer, a laminate of metal foil such as aluminum has good gas barrier properties and is also economical, but because it is opaque, the contents at the time of packaging cannot be seen, and it does not transmit microwaves. Processing by microwave oven is not possible.

Further, those coated with a gas barrier layer of vinylidene chloride, ethylene vinyl alcohol copolymer or the like do not have sufficient gas barrier properties against water vapor, oxygen, etc., and the performance is remarkably deteriorated particularly at high temperature treatment. In addition, for vinylidene chloride, there is a problem of air pollution due to generation of chlorine gas at the time of incineration.

On the other hand, as a gas barrier film whose contents can be seen and which can be applied to a microwave oven, Japanese Patent Publication No. 51-48 (1971) is disclosed.
No. 551 discloses that the surface of a synthetic resin film is made of SiO _x
A gas barrier film on which (for example, SiO ₂ ) has been deposited has been proposed. However, a SiO _x (x = 1.3 to 1.8) oxide film having a good gas barrier property has a slightly brown color and transparency. Is inadequate.

An oxide film mainly composed of aluminum oxide as disclosed in Japanese Patent Application Laid-Open No. Sho 62-101428 is known as one having sufficient transparency. In addition, it is inferior in bending resistance and does not withstand the gelbo flex test (a test method for forcibly bending a cylindrical test piece to evaluate flexibility).

That is, a laminated film having an inorganic film such as silica or alumina as a gas barrier layer has a problem in film strength, and also has a problem in that the gas barrier property is deteriorated by a boiling treatment or a retort treatment. An inorganic vapor-deposited layer such as silica or alumina is formed of a polyester film (PE
T) is often deposited. For example, in the case of a laminated structure such as PET / deposited layer / adhesive layer / stretched nylon (ONY) / adhesive layer / unstretched polypropylene (CPP), boiling treatment or retort is caused by shrinkage of nylon. Since the gas barrier property is deteriorated due to the shrinkage of nylon during the treatment, it is customary to eliminate the lamination of nylon and make a laminated structure of PET / deposited layer / adhesive layer / PET / adhesive layer / unstretched polypropylene (CPP). ing. However, in the laminated film having the above-described structure in which the lamination of nylon is eliminated, insufficient strength at the time of dropping becomes a serious problem.

Furthermore, the shrinkage rate of a stretched nylon (Japanese Patent Publication No. Hei 7-12649) used as a vapor deposition base material and a nylon (Japanese Patent Laid-Open Publication No. Hei 7-276571) as a laminate is reduced during high-temperature treatment. Although those with strength have been proposed, there is a problem that the manufacturing process of nylon and the process of transport and storage are complicated,
Not suitable for practical use. Further, nylon having a reduced shrinkage rate during high-temperature treatment (Japanese Patent Publication No.
(The sum of the absolute values of the dimensional change rates in the vertical and horizontal directions due to heat treatment for 5 minutes is specified to be 2% or less), but in the case of boiling treatment or retort treatment as a high-temperature hot water treatment, nylon is used. , The gas barrier property cannot be maintained.

Further, in the technique disclosed in Japanese Patent Application Laid-Open No. 7-276571, it is necessary to laminate a low-shrinkage nylon layer separately from the vapor-deposited base material layer, which complicates the process, leading to an increase in manufacturing cost and heat. There is also a problem that the mechanical strength of the polyamide film decreases during the fixing operation.

Further, no consideration is given to the shrinkage of the vapor deposition base material and the entire laminated component, and a laminated film capable of maintaining a sufficient gas barrier property even after boiling or retorting is not commercially available.

The present invention has been made in view of such circumstances, and has an object to provide excellent strength characteristics and gas barrier properties without impairing the excellent gas barrier properties even after retort treatment or boiling treatment. Another object of the present invention is to provide a gas barrier laminate film which can be suitably used for heat sealing.

[0016]

Means for Solving the Problems The gas barrier laminate film or sheet according to the present invention, which can solve the above-mentioned problems, comprises a base layer composed of a polyamide-based film on one side or both sides of an inorganic vapor-deposited layer. In the laminated film on which the gas barrier layer was formed and the heat-sealing layer was further formed, the compression elastic modulus at 40 ° C. of the heat-sealing layer was 10 kgf / mm ² or more, and the laminated film was retorted at 120 ° C. for 30 minutes. When the shrinkage in each direction is 4.5% or less, or when the laminated film is boiled at 95 ° C. for 30 minutes, the shrinkage in each direction is 3.5% or less. This is characterized in that excellent gas barrier properties can be maintained after the treatment or after the boiling treatment.

In the present invention, in addition to the above configuration,
After retorting at 120 ° C for 30 minutes or 95%
The adhesion strength between the base layer and the gas barrier layer after the boiling treatment at 30 ° C. for 30 minutes is set to 100 g / 15 mm or more. Further, by providing an adhesion improving layer as an undercoat layer between the base layer and the gas barrier layer, This is preferable because the performance can be further improved.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the gas barrier laminate film of the present invention comprises a polyamide resin film as a base layer, and a gas barrier layer comprising an inorganic vapor deposited layer and a heat seal layer on one or both sides thereof. (1) The heat seal layer has a compression elastic modulus at 40 ° C. of 10 kgf / mm ² or more (more preferably 20 kgf / mm ² or more, further preferably 40 kgf / mm ^2). (2-1) The shrinkage rate in each direction when the entire laminated component is subjected to a retort treatment at 120 ° C. for 30 minutes is 4.5% or less (more preferably 1.5% or less, more preferably 1.5% or less). (Preferably 0.7% or less)) or (2-2) 95 ° C. × 3 as a whole
The shrinkage rate in each direction when the boiling treatment is performed for 0 minutes is 3.5% or less (more preferably 1.5% or less, and still more preferably 0.7% or less). Preferably, in addition to these properties, (3) the adhesion strength between the base layer and the inorganic vapor-deposited layer after performing a retort treatment at 120 ° C. for 30 minutes or a boiling treatment at 95 ° C. for 30 minutes is 100 g.
/ 15 mm or more.

Hereinafter, each of the laminated components specified in the present invention will be described in detail, and the reason for defining the above characteristics will be described in detail.

In the gas barrier laminate film of the present invention, the heat seal layer protects the inorganic vapor-deposited layer constituting the gas barrier layer and acts as a thermal adhesive layer during bag making. According to the study, the compression elastic modulus of the heat seal layer has a remarkable effect on the gas barrier property after retort treatment or boiling treatment of the obtained gas barrier laminate film, and the heat seal layer at 40 ° C. 10 kg compression modulus
f / mm ² or more, more preferably 20 kgf / mm ² or more, if more preferably Shiteyare to 40 kgf / mm ² or more, does not occur a decrease in gas barrier properties due to retort treatment or boiling treatment, stable and excellent gas barrier properties to maintain I knew it would be done. The reason is considered as follows.

That is, as described above, the heat seal layer has an effect of protecting the inorganic vapor-deposited layer constituting the gas barrier layer as one of its functions. It is considered that the compressive deformation at the time of the treatment or the boiling treatment causes a deformation stress to be generated in the inorganic vapor-deposited layer, which may cause the inorganic vapor-deposited layer to be broken or peeled off. However, as will be apparent from the examples described later, the compression elastic modulus of the heat seal layer at 40 ° C. was 10 kgf.
/ Mm ² or more, the destruction or peeling of the above-described inorganic vapor-deposited layer due to retort treatment or boiling treatment does not occur,
It is considered that excellent gas barrier properties are stably maintained. Here, the reason why the compression elastic modulus is defined as a value at “40 ° C.” is that the temperature history received for a long time in the normal distribution process is about 40 ° C., which is considered to be the closest to the film storage environment. .

The materials constituting the heat seal layer include polyethylene and ethylene copolymers, polyvinyl alcohol, ethylene-vinyl alcohol copolymer,
Films made of olefin resins such as polypropylene and propylene copolymers; Films made of vinyl chloride resins such as polyvinyl chloride and their copolymers; Films made of vinylidene chloride resins such as vinylidene chloride-vinyl chloride copolymer Film: a film made of a polyester resin such as polyethylene terephthalate; a film made of a fluorine resin such as polytetrafluoroethylene; and further, a coat film obtained by further coating these films with a resin different from the sealant base film. . In selecting them, it is necessary to select the material in consideration of the thickness of the heat seal layer and the like so that the compression elastic modulus at 40 ° C. can be 10 kgf / mm ² or more as described above. .

The heat-sealing layer may be a modified or blended resin of the above resin as long as the above-mentioned compression modulus can be satisfied, or an unstretched or unstretched film of the constituent materials. It may be uniaxially or biaxially stretched, and may have a single-layer structure or a multi-layer structure of the same or different materials. Specifically, for example, in order to enhance the laminating property and the heat sealing property, it is combined with a resin having a glass transition temperature (Tg) or a melting point lower than that of the thermoplastic resin serving as the base of the heat sealing layer, or the heat resistance is increased. Therefore, conversely, it can be combined with a resin having a high Tg or a high melting point.

The heat seal layer is laminated on the inorganic vapor-deposited layer constituting the gas barrier layer. In the lamination, for example, a polyurethane resin, an acrylic resin, a polyester resin, An arbitrary adhesive such as an epoxy resin, a vinyl chloride resin, a vinyl acetate resin, a polyethylene resin, a polypropylene resin, and a melamine resin can be used.
These resins may be used as a mixture of two or more kinds as necessary in order to enhance the adhesive strength. In addition, as a functional group, for example, a carboxylic acid group, an acid anhydride, (meth) acrylic acid, or (meth) A compound having an acrylic ester skeleton,
Epoxy compounds containing glycidyl or glycidyl ether groups, oxazoline groups, isocyanate groups, amino groups,
It is also effective to use an appropriate amount of a compound having a hydroxyl group or the like.

These adhesive resins can be formed by a so-called dry lamination method, a wet lamination method using an emulsion, a melt extrusion lamination method, a coextrusion lamination method, or the like.

When the heat seal layer is formed by coating, a coating agent is used. Suitable coating agents in this case include vinylidene chloride resins such as vinylidene chloride-vinyl chloride copolymer and polyester resins such as polyethylene terephthalate. And a solution or an emulsion of a fluororesin such as polyvinyl difluoride. Among them, a latex of a vinylidene chloride-based resin and a solution in which a vinylidene chloride-based resin is dissolved in a solvent such as tetrahydrofuran are preferable.

When a vinylidene chloride-based resin is applied, an adhesion promoter such as an isocyanate-based, polyethyleneimine-based, or organic titanium-based adhesive, or a polyurethane-based or polyester-based adhesive can be applied between the resin and the coating base.

The material of the polyamide film used as the base layer in the present invention is not particularly limited, and any of a homopolyamide, a copolyamide, a mixture thereof, or a crosslinked product thereof can be used. For example, the following formula (1) or ( 2)
A homopolyamide having an amide repeating unit represented by the formula:
Copolyamide, a mixture thereof, or a crosslinked product thereof can be mentioned.

—CO—R ₁ —NH— (1) —CO—R ₂ —CONH—R ₃ —NH (2) (wherein R ₁ , R ₂ and R ₃ are straight-chain alkylene, Represents an aromatic ring or an aliphatic alkyl group)

Specific examples of preferred homopolyamides include polycaproamide (nylon 6), poly-ω-aminoheptanoic acid (nylon 7), poly-9-aminononanoic acid (nylon 9), and polyundecaneamide (nylon 1).
1), polylaurin lactam (nylon 12), polyethylene diamine adipamide (nylon 2, 6), polytetramethylene adipamide (nylon 4, 6), polyhexamethylene dizipamide (nylon 6, 6), poly Hexamethylene sebacamide (nylon 6,10), polyhexamethylene dodecamide (nylon 6,12), polyoctamethylene adipamide (nylon 8,6), polydecamethylene adipamide (nylon 10,6), Polydecamethylene sebacamide (nylon 10, 10), polydodecamethylene dodecamide (nylon 12, 12), metaxylene diamine-6 nylon (MXD6) and the like can be mentioned.

Examples of the copolyamide include caprolactam / laurin lactam copolymer, caprolactam /
Hexamethylene diammonium adipate copolymer, laurin lactam / hexamethylene diammonium adipate copolymer, hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer, ethylene diammonium adipate / hexamethylene diammonium adipate copolymer And caprolactam / hexamethylenediammonium adipate / hexamethylenediammonium sebacate copolymer.

These polyamide resins may be blended with a plasticizer such as aromatic sulfonamides, p-hydroxybenzoic acid, esters, etc., for imparting flexibility, or may contain an elastomer component or lactam having a low elastic modulus. It is also possible to mix. Examples of the elastomer component include an ionomer resin, a modified polyolefin resin, a thermoplastic polyurethane, a polyether block amide, a polyester block amide, a polyether ester amide elastomer, a polyester elastomer, a modified styrene thermoplastic elastomer, a modified acrylic rubber, and a modified acrylic rubber. And ethylene propylene rubber.

If necessary, other additives such as a plasticizer, a heat stabilizer, an ultraviolet absorber, an antioxidant, a coloring agent, a filler, an antistatic agent, an antibacterial agent, and a lubricant may be contained in the resin constituting the base layer. It is also possible to blend an appropriate amount of an anti-blocking agent, another resin or the like. On one side of the polyamide-based film constituting the base layer, an inorganic vapor-deposited layer constituting a gas barrier layer is formed. Before or during the vapor deposition, the surface of the polyamide-based film is subjected to corona treatment, flame treatment, It is also effective to perform a low-temperature plasma treatment, a glow discharge treatment, a reverse sputtering treatment, a surface roughening treatment, and the like to increase the adhesion to the deposition layer.

That is, it is extremely effective to enhance the adhesion between the base layer and the inorganic vapor-deposited layer in order to exhibit sufficient gas barrier properties by the inorganic vapor-deposited layer. It is effective to perform an adhesion improving treatment on the vapor deposition surface side, but as another means, it is also extremely effective to form an anchor coat layer in order to increase the adhesion of the vapor deposition layer.

Preferred resins used as such an anchor coat layer include reactive polyester resins, oil-modified alkyd resins, urethane-modified alkyd resins, melamine-modified alkyd resins, epoxy-modified acrylic resins, epoxy resins (an amine as a curing agent) , Carboxyl-terminated polyesters, phenols, isocyanates, etc.), isocyanate resins (amines as curing agents,
Urea, carboxylic acid, etc.), urethane-polyester resin, polyurethane resin, phenol resin, polyester resin, polyamide resin, reactive acrylic resin, vinyl chloride resin and the like. It can be used as a latex, aqueous liquid (aqueous solution or aqueous dispersion).

As a method for forming the anchor coat layer,
Any of an in-line method in which a polyamide-based film is applied and an off-line method in which a polyamide-based film is applied in a separate step can be adopted. For the coating, any known method such as a roll coating method, a reverse coating method, a roll brushing method, a spray coating method, an air knife coating method, a gravure coating method, an impregnation method, a curtain coating method, or the like may be arbitrarily selected and employed. be able to.

The anchor coat layer is subjected to a corona treatment, a flame treatment, a low-temperature plasma treatment, a glow discharge treatment, a reverse sputtering treatment, a roughening treatment or the like before or during the vapor deposition,
It is also effective to further increase the adhesion to the inorganic vapor deposition layer.

The inorganic vapor-deposited layer is a constituent material that is indispensable for imparting gas barrier properties to the laminated film. The type of the inorganic vapor-deposited layer is not particularly limited. Al, Si, Ti, Zn, Zr, M
metals such as g, Sn, Cu, Fe and oxides of these metals;
Nitride, fluoride, sulfide, etc., more specifically, Si
O _x (x = 1.0-2.0), alumina, magnesia,
Examples thereof include zinc sulfide, titania, zirconia, and cerium oxide. These may be formed as a mixed vapor-deposited layer of two or more types or a multi-layered vapor-deposited layer as necessary.

The preferred thickness of the inorganic vapor-deposited layer is generally in the range of 10 to 5000 °, more preferably 50 to 2000 °. If the thickness is less than 10 °, it is difficult to obtain sufficient gas barrier properties. Even if the thickness is too large, no further improvement in gas barrier properties can be obtained, which is rather disadvantageous in terms of bending resistance and manufacturing cost.

For the formation of the inorganic vapor deposition layer, a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method or an ion plating method, or a chemical vapor deposition method such as a PECVD method is appropriately selected and used. Preferred deposition materials when employing the vacuum deposition method include metals such as aluminum, silicon, titanium, magnesium, zirconium, cerium, and zinc,
Alternatively, SiO _x (x = 1.0 to 2.0), alumina,
Compounds such as magnesia, zinc sulfide, titania, and zirconia, and mixtures thereof are used. As a heating method, resistance heating, induction heating, electron beam heating, or the like can be used. As the reaction gas, oxygen, nitrogen, hydrogen, argon, carbon dioxide gas, water vapor, or the like may be introduced, or reactive vapor deposition using means such as ozone addition or ion assist may be used. Further, a bias may be applied to the substrate, or film forming conditions such as heating and cooling of the substrate may be changed. The above-mentioned deposition material, reaction gas, substrate bias, heating / cooling, and the like can be similarly changed in film forming conditions when a sputtering method or a CVD method is adopted.

Before or during the vapor deposition, the surface of the vapor-deposited substrate is subjected to a corona treatment, a flame treatment, a low-temperature plasma treatment, a glow discharge treatment, a reverse sputtering treatment, a surface roughening treatment, etc.
As described above, it is effective to enhance the adhesion of the deposited film.

In the gas barrier laminate film of the present invention, a gas barrier layer composed of an inorganic vapor-deposited layer is formed on one side or both sides of the polyamide film constituting the base layer as described above, with or without an anchor coat layer. ,
Further, it has a laminated structure in which a heat seal layer is formed thereon. The first characteristic is that the heat seal layer has a compression elastic modulus at 40 ° C. of 10 kgf / m as described above.
lies were identified m ² or more, but further serve the purpose of the present invention, as the heat shrinkage properties of the overall multilayer film, each direction of shrinkage when subjected to retorting 120 ° C. × 30 minutes In any case, the shrinkage rate in each direction when performing the boiling treatment at 95 ° C. for 30 minutes is 4.5% or less (more preferably 1.5% or less, further preferably 0.7% or less). 3.5% or less (more preferably 1.%)
5% or less, more preferably 0.7% or less), and the base layer and the inorganic vapor-deposited layer after further performing a retort treatment at 120 ° C. for 30 minutes or a boiling treatment at 95 ° C. for 30 minutes. It is important that the adhesion strength be 100 g / 15 mm or more.

That is, in the present invention, as described above, an object is to maintain excellent gas barrier performance even after retort treatment or boiling treatment. Specifies shrinkage characteristics. Thus, when the heat shrinkage rate of the entire laminated film becomes large, a large tensile force acts on the thin, heat-shrinkable inorganic vapor-deposited layer of the film constituent layers, and the vapor-deposited layer suffers tensile breakage or peeling. This causes the subsequent gas barrier properties to be significantly reduced.

The present inventors have confirmed through many experiments that, when applied to a packaging application in which retort treatment is performed at the time of use, the shrinkage ratio when performing retort treatment at 120 ° C. for 30 minutes. 4.5% or less (more preferably 1.5% or less, further preferably 0.7%
Below), when applied to a packaging application in which a boiling treatment is performed at the time of use, the shrinkage rate after performing a boiling treatment at 95 ° C. for 30 minutes is 3.5% or less (more preferably 1.5% or less, further more preferably , Which is 0.7% or less), it was confirmed that the reduction in gas barrier properties due to the heat treatment was surely suppressed, and that excellent gas barrier properties were maintained even after the treatment. In addition, the shrinkage rate referred to above means the shrinkage rate in each of the vertical, horizontal, and diagonal directions of the entire laminated film,
All of them need to satisfy the above-mentioned values, and when the shrinkage in any one direction exceeds the above-mentioned value, the gas barrier property is significantly deteriorated by the retort treatment or the boiling treatment.

Further, as described above, the above-mentioned deterioration of the gas barrier property is caused by delamination of the inorganic vapor deposition layer, and suppressing such delamination is extremely effective in preventing the deterioration of the gas barrier property. For this reason, in the present invention, the retort treatment at 120 ° C. for 30 minutes or the 95 ° C.
The adhesion strength between the base layer and the inorganic vapor-deposited layer after performing the boiling treatment for 30 minutes is specified to be 100 g / 15 mm or more. By defining such adhesion strength, it is possible to more reliably suppress a decrease in gas barrier properties. Becomes possible.

The means for ensuring the above-mentioned shrinkage ratio of the entire laminated film is not particularly limited. For example, the object can be easily achieved by appropriately combining the following means.

(1) As a material for a polyamide film,
Select a moisture-resistant material that has a small shrinkage rate under heating conditions.
Specifically, a polyamide film having a maximum shrinkage in each direction at 170 ° C. for 10 minutes of about 3.5% or less, more preferably about 1.5% or less, and still more preferably about 0.7% or less. Is preferred.

(2) As a material for a polyamide film,
Select a moisture-resistant material with low shrinkage stress under heating conditions. Specifically, the maximum shrinkage stress in each direction at 170 ° C. for 10 minutes is 900 gf / mm ² or less, more preferably 4 gf / mm ² or less.
00 gf / mm ² or less, more preferably 200 gf / m 2
Polyamide-based films having an m ² or less are preferred.

(3) Provided between the base layer and the gas barrier layer
Compression elastic modulus as an adhesion improving layer (anchor coat layer)
Select a material with a large thickness or control the film thickness appropriately.
You. Specifically, the pressure at 40 ° C. is used as the adhesion improving layer.
The shrink modulus is 9.8kgf / mm ^Two Above, preferably 35
kgf / mm^Two Above, more preferably 60 kgf / mm
^Two Select the above resin and set the film thickness to 0.02 μm or more.
0.2 μm or more, more preferably 0.5 μm or more
And

(4) For the adhesion between the heat seal layer and the gas barrier layer, a resin having a large compression elastic modulus is selected, or its thickness is appropriately controlled. Specifically, 40 as an adhesive
The compression elastic modulus at ℃ is 8.8 kgf / mm ² or more, preferably 30 kgf / mm ² or more, more preferably 50 kgf / mm ² or more.
Select resin of kgf / mm ² or more and set thickness to 0.2μm
The thickness is preferably 1 μm or more, more preferably 4 μm or more.

In the present invention, the thickness of the laminated film as a whole is not particularly limited as long as the above-mentioned shrinkage ratio can be satisfied, but the practicality, strength, flexibility, economy and the like as a laminated film for packaging are comprehensively evaluated. 10 to 1000 μm, more generally 50 to 300 μm
Range. In addition to this laminated film, in addition to at least a three-layer laminated structure composed of the essential constituent materials described above, or at least a four-layer laminated structure including an anchor coat layer, in practical use, paper, non-woven fabric, aluminum Of course, it is also possible to reinforce by laminating a foil or the like, to provide a printed layer, or to laminate a printed film.

Since the gas barrier laminate film of the present invention thus obtained hardly loses its gas barrier properties even by the retort treatment or the boiling treatment as described above, packaging materials for foods and the like to which these treatments are applied in the packaging process. For example, miso, pickles, side dishes, baby food, boiled tsukudani, konjac, chikuwa, kamaboko, processed fishery products, meatballs, hamburgers, genghis khan, ham, sausage, other processed meat products, tea, coffee, tea, bonito, tororo Oil confectionery such as kelp, potato chips, butter peanuts, rice crackers,
Biscuits, cookies, cakes, buns, castella, cheese, butter, cutlets, soups, sauces, ramen, wasabi, and other toothpaste, pet food,
Widely used in various forms such as bags, lids, cups, tubes, standing bags, etc. for agrochemicals, fertilizers, infusion packs, and also for industrial materials such as semiconductor packaging and precision material packaging, such as medical, electronic, chemical, and mechanical packaging. be able to.

[0053]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples, and the scope of the present invention can be adapted to the above and following points. It is also possible to carry out the present invention with appropriate modifications, and all of them are included in the technical scope of the present invention. In addition, each performance evaluation method adopted in the following examples is as follows.

(Gas Barrier Property) The amount of oxygen permeation was measured using an oxygen permeability measuring device (“OX-TRAN 10 / 50A” Mod).
ern Controls), humidity was 0%, temperature was 25 ° C, and purged for 2 days. In addition, the water vapor transmission rate can be measured by a water vapor transmission rate measuring device (“PERMATRAN” Mode).
rn Controls, Inc.) at a temperature of 40 ° C., a humidity of 90% and a 2-day purge.

(Adhesion strength) According to JIS-K6854,
The s-s curve when the laminate was peeled at 90 degrees was measured by "Tensilon UTM2" manufactured by Toyo Sokki Co., Ltd. An electron microscope and a fluorescent X-ray analyzer manufactured by Rigaku Denki Co., Ltd. were used together to identify the peeling interface between the gas barrier layer and the substrate.

(Shrinkage ratio) The film to be processed is 20 mm in diameter.
Cut into 0 mm circles, vertical, horizontal, and 30 degrees, 45
The degree and the degree are measured at a temperature of 25 ° C. and a humidity of 0%. Then, after retort treatment with hot water at 120 ° C. for 30 minutes or boiling treatment at 95 ° C. for 30 minutes, immediately measure vertical, horizontal, and 30 °, 45 °, and 60 ° dimensions, and determine the shrinkage in each direction. Ask for.

(Compression Modulus) The compression modulus was measured according to JIS-K7208 using an “SSTMA measuring device” manufactured by Rigaku Corporation.

Example 1 A polyamide resin serving as a base film was 15 μm thick.
m, a nylon film “N1102” manufactured by Toyobo Co., Ltd. was used to form an inorganic vapor-deposited layer in the following procedure.

That is, the above nylon film is vacuum-evaporated.
1 × 10 inside the chamber ^-FiveTorr pressure
Holding, SiO_Two : 70% by weight and Al_Two O_Three : 30 weight
% Mixed oxide was evaporated by 15 kW electron beam heating.
A 150mm thick colorless and transparent inorganic oxide layer with nylon
Deposit on the substrate. Next, a heat seal is placed on the deposition layer.
Unstretched polyethylene (thickness: 55 micron)
Compression modulus: 10.0 kg / mm^Two ), Glue
("A310 / A10" manufactured by Takeda Pharmaceutical Co., coated amount 2 g / m
^Two ) And laminate at 45 ° C for 4 days.
Zing was performed to obtain a gas barrier laminated film.

The dimensional changes of the laminated film before and after the retort treatment at 120 ° C. for 30 minutes and the boiling treatment at 95 ° C. for 30 minutes, and the oxygen permeation amount, water vapor permeation amount and adhesion strength after the treatment were measured.

Example 2 In Example 1 above, a nylon film as a substrate was
A gas-barrier laminated film was produced in the same manner as in Example 1 except that a polyester resin (“Byron RV500” manufactured by Toyobo Co., Ltd.) was coated at a thickness of 0.5 μm as an anchor coat layer. ° C
The dimensional changes before and after the 30-minute retort treatment and the boiling treatment at 95 ° C. for 30 minutes, and the oxygen permeation amount, water vapor permeation amount, and adhesion strength after the treatment were measured.

Example 3 In Example 1, the deposition material was changed to silicon monoxide (Si).
O: purity 99%) to produce a gas barrier laminate film in exactly the same manner except that
The dimensional changes before and after the retort treatment at 30 ° C. for 30 minutes and the boiling treatment at 95 ° C. for 30 minutes, and the oxygen permeation amount, water vapor permeation amount, and adhesion strength after the treatment were measured.

Example 4 A gas-barrier laminated film was produced in exactly the same manner as in Example 1 except that unstretched polyethylene (compression elastic modulus: 40 kg / mm ² ) was used as a heat seal layer constituting material. A performance evaluation test was performed in the same manner.

Example 5 A gas-barrier laminated film was produced in exactly the same manner as in Example 1 except that unstretched polyethylene (compression elastic modulus: 60 kg / mm ² ) was used as a heat seal layer constituting material. A performance evaluation test was performed in the same manner.

Comparative Example 1 A gas barrier laminated film was produced in the same manner as in Example 1, except that unstretched polyethylene (compression modulus: 5.2 kg / mm ² ) was used as a constituent material of the heat seal layer. It was manufactured and a performance evaluation test was performed in the same manner.

Comparative Example 2 A gas barrier laminated film was produced in the same manner as in Example 2 except that polyvinyl alcohol (2 μm) was used as a constituent material of the anchor coat layer, and a performance evaluation test was performed in the same manner. Was performed.

The results are as shown in Table 1 below. In the examples satisfying all the requirements of the present invention, very low oxygen permeation and water vapor permeation were maintained both after the retort treatment and after the boiling treatment. On the other hand, in Comparative Examples which do not satisfy the requirements of the present invention, the oxygen permeation amount and the water vapor permeation amount after the retort treatment and the boiling treatment are significantly increased, and the gas barrier property is significantly deteriorated.

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[Table 1]

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The present invention is constituted as described above, and exhibits excellent barrier properties under ordinary handling conditions, and does not impair the excellent gas barrier properties even after retort treatment or boiling treatment. In addition, it has excellent properties in all of strength, flexibility, heat sealability, and economy, and the gas barrier property is not impaired even when used for a long time under high temperature, high humidity conditions . Therefore, food,
It can be widely and effectively used for a wide range of packaging materials requiring high gas barrier properties, including packaging materials for pharmaceuticals and industrial materials.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B32B 27/34 B32B 27/34 C08J 7/04 CFG C08J 7/04 CFGP 7/06 CFG 7/06 CFGZ C23C 14/20 C23C 14/20 A // C08L 77:00 (72) Inventor Yozo Yamada 2-1-1 Katada, Otsu-shi, Shiga Prefecture Toyobo Co., Ltd. Research Laboratory

Claims (5)

[Claims] 1. A laminated film in which a gas barrier layer composed of an inorganic vapor-deposited layer is formed on one side or both sides of a base layer composed of a polyamide-based film, and further a heat seal layer is formed. Wherein the compression elastic modulus is 10 kgf / mm ² or more and the shrinkage in each direction is 4.5% or less when the laminated film is retorted at 120 ° C. for 30 minutes. Film or sheet. 2. The adhesive strength between the base layer and the gas barrier layer after retort treatment at 120 ° C. for 30 minutes is 100 g / 15.
The gas-barrier laminated film or sheet according to claim 1, which is not less than mm. 3. A laminated film in which a gas barrier layer made of an inorganic vapor-deposited layer is formed on one side or both sides of a base layer made of a polyamide-based film, and further a heat seal layer is formed. A gas-barrier laminated film, wherein the elastic modulus is 10 kgf / mm ² or more, and the shrinkage in each direction when the laminated film is boiled at 95 ° C. for 30 minutes is 3.5% or less. Sheet. 4. The gas-barrier laminated film or sheet according to claim 3, wherein the adhesive strength between the base layer and the gas barrier layer after boiling at 95 ° C. for 30 minutes is 100 g / 15 mm or more. 5. The gas barrier laminate film or sheet according to claim 1, wherein an adhesion improving layer is provided between the base layer and the gas barrier layer.