JP5915210B2 - Boil and retort packaging materials and pouches - Google Patents

Description

  The present invention relates to a packaging material for boil / retort treatment and a pouch comprising the same, and more particularly, for example, a packaging material that can be suitably used for packaging foods, medicines, beverages, etc., in particular, contents subjected to boil / retort treatment. And a pouch comprising the same.

  For packaging materials for boil sterilization treatment or retort sterilization treatment, especially those with low elution, that is, a type in which elution of various chemical substances contained in the packaging material is suppressed is used in packaging materials, for example. A packaging material using a low-eluting adhesive as a bonding agent and a packaging material using a cyclic polyolefin containing an oxygen absorbent or a water vapor absorbent have been proposed (for example, Patent Document 1).

  A low-elution packaging material using a non-solvent adhesive or non-solvent ink has also been proposed (Patent Document 2).

  However, these packaging materials are expensive and unsuitable as packaging materials for general foods, and are mainly used for industrial and electronic parts.

Japanese Patent No. 4144320 Japanese Patent No. 4733420

  The present invention solves the above-mentioned problems, is cheaper, has a low elution property and excellent transparency, and is a packaging material for boil treatment or retort treatment (hereinafter referred to as “boil / retort treatment”) and the like. It aims at providing the pouch which consists of.

  As a result of various studies, the present inventor has at least a transparent gas barrier film layer, an adhesive layer, and a sealant film layer in this order, and the transparent gas barrier film layer includes at least a polyester resin layer and A layer having a biaxially stretched multilayer film obtained by biaxially stretching a multilayer film having a polyamide-based resin layer, wherein the sealant film layer has at least a layer made of linear low-density polyethylene. It was found that the packaging material for boil and retort processing achieves the above-mentioned purpose.

  The present invention is characterized by the following points.

1. In a packaging material having at least a transparent gas barrier film layer, an adhesive layer, and a sealant film layer in this order, the transparent gas barrier film layer is a multilayer film having at least a polyester resin layer and a polyamide resin layer. A packaging material for boil and retort treatment, comprising a biaxially stretched multilayer film obtained by axial stretching, wherein the sealant film layer has at least a layer composed of linear low density polyethylene .
2. The sealant film layer is a layer made of a multilayer coextruded film comprising at least a linear low density polyethylene layer and a layer made of nylon 6/12, and the linear low density polyethylene layer is packaged A layer that forms a wetted surface of the material, and the layer of nylon 6/12 has an unreacted residual ε-caprolactam content of 0.8% by mass or less, and an unreacted residual ω- The content of laurolactam is not more than 0.1% by mass, and in the single-sided dissolution test, when the sample is brought into contact with a sufficient amount of 95% ethanol and heated at 121 ° C. for 2 hours, The mass of residual ε-caprolactam and ω-laurolactam in the reaction is 0.15 mg or less and 0.04 mg or less per square inch of the sealant film layer, respectively. Packaging material for boiling or retort processes described.
3. The sealant film layer is a layer made of a multilayer coextruded film comprising at least a linear low density polyethylene layer and a layer made of nylon 6/12, and the linear low density polyethylene layer is packaged A layer that forms a wetted surface of the material, and the layer of nylon 6/12 has an unreacted residual ε-caprolactam content of 0.8% by mass or less, and an unreacted residual ω- The unreacted residual ε-caprolactam, which has a laurolactam content of 0.1% by mass or less and elutes in water when it is extracted at room temperature for 5 hours in contact with a sufficient amount of water in a single-side dissolution test. And the mass of ω-laurolactam is 0.15 mg or less and 0.04 mg or less per square inch of the sealant film layer, respectively, and the boil processing packaging material according to 1 above.
4). The sealant film layer is a layer made of a multilayer coextruded film comprising at least a linear low density polyethylene layer and a layer made of nylon 6/12, and the linear low density polyethylene layer is packaged A layer that forms a wetted surface of the material, and the layer of nylon 6/12 has an unreacted residual ε-caprolactam content of 0.8% by mass or less, and an unreacted residual ω- The content of laurolactam is 0.1% by mass or less, and in a single-sided dissolution test, when extracted at 100 ° C. for 8 hours in contact with a sufficient amount of water, the mass of nitrogen eluted in the water is the sealant film. 2. The boil processing packaging material according to 1 above, wherein the layer is 15 μg or less per square centimeter and 100 μg or less per square inch.
5. The transparent gas barrier film layer is a biaxially stretched multilayer film obtained by biaxially stretching a multilayer film having at least a polyester resin layer and a polyamide resin layer, and an inorganic oxide is deposited on one surface thereof. 2. The packaging material for retort processing according to 1 above, wherein the packaging material is an inorganic oxide vapor-deposited film comprising the vapor-deposited layer. 6). The polyester resin layer contains a crystalline polyester, and the polyamide resin layer contains 70 to 99% by mass of an aliphatic polyamide and 1 to 30% by mass of an aromatic polyamide. The packaging material for retort processing as described.
7). The crystalline polyester is at least one selected from the group consisting of polyethylene terephthalate, isophthalic acid copolymerized polyethylene terephthalate, polybutylene terephthalate, and sulfoisophthalic acid copolymerized polyethylene terephthalate. Packaging material for retort processing.
8). 8. The packaging material for retort processing according to 6 or 7 above, wherein the aliphatic polyamide is at least one selected from the group consisting of nylon 6 and a nylon copolymer of nylon 6 and nylon 66. .
9. The packaging material for retort processing according to any one of the above 6 to 8, wherein the aromatic polyamide is polymetaxylene adipamide or amorphous nylon.
10. 10. Said 5-9 characterized by the said vapor deposition layer being a layer formed by vapor-depositing at least 1 sort (s) of inorganic oxide selected from the group which consists of a silicon oxide, aluminum oxide, and magnesium oxide. Packaging material for retort processing.
11 When extracted with deionized distilled water at 135 ° C. for 1 hour, the mass of the eluate eluted into the water is 0.008 mg or less per square centimeter of the sealant film layer and 0.05 mg or less per square inch. The packaging material for retort processing according to 1 above.
12 When extracted with deionized distilled water at 121 ° C. for 2 hours, the mass of the chloroform-soluble component of the non-volatile extract eluted in the water is not more than 0.016 mg per square centimeter of the sealant film layer and 0.001 per square inch. The packaging material for boil processing according to 1 above, wherein the packaging material is 10 mg or less.

  The packaging material for boil / retort processing of the present invention is made of an inexpensive material and exhibits excellent low elution properties.

  In particular, the packaging material of the present invention exhibits excellent low elution by having a layer made of nylon 6/12 in the sealant film. Accordingly, the base film, adhesive, printing ink, and the like positioned on the non-wetted side of the sealant film are not limited to those made of a special material with low elution, and any one can be used. .

  Furthermore, the packaging material of the present invention can withstand boil treatment and retort treatment, and retains excellent low elution even under such high temperature and high pressure conditions. Therefore, the pouch made of the packaging material of the present invention can be suitably used as a boil / retort processing pouch for packaging foods and beverages.

  The packaging material of the present invention is basically a laminate of two films, a transparent gas barrier film and a sealant film, with an adhesive, and thus can be made thinner and lighter. Yes, it can reduce the volume of garbage and reduce the transportation cost of products.

  Moreover, in the packaging material of this invention, a base film is a transparent gas barrier film, shows high gas barrier property and transparency, and is excellent in quality maintenance property. Therefore, it can be suitably used for the packaging of a wide variety of contents such as foods, beverages, pharmaceuticals or electrical / electronic parts that dislike various chemical substances eluted from the packaging material, oxygen and water vapor that permeate the packaging material. .

It is a schematic sectional drawing which shows the example about the layer structure of the packaging material of this invention. It is a schematic sectional drawing which shows the example about the layer structure of the packaging material of this invention. It is a schematic sectional drawing which shows the example about the layer structure of the packaging material of this invention. It is a schematic sectional drawing which shows the example about the layer structure of the packaging material of this invention. It is a schematic sectional drawing which shows the example about the layer structure of the packaging material of this invention.

The above-described present invention will be described in more detail below.
Hereinafter, the resin names used in the present invention are those commonly used in the industry.
In the present invention, the density is measured by a method based on JIS K7112.

<I> Layer Configuration of Packaging Material FIG. 1 is a schematic cross-sectional view showing an example of the layer configuration of the packaging material of the present invention.
As shown in FIG. 1, the packaging material of the present invention comprises a transparent gas barrier film layer 1, an adhesive layer 2 and a sealant film layer 3. The transparent gas barrier film layer 1 comprises a polyester resin layer 1a and a polyamide resin. It consists of two layers of resin layer 1b.

In another embodiment, as shown in FIG. 2, in the packaging material of the present invention, the sealant film layer 3 is composed of two layers of a layer 3a made of nylon 6/12 and a linear low density polyethylene layer 3b.
In another embodiment, as shown in FIG. 3, the transparent gas barrier film layer 1 is composed of three layers of a first polyester resin layer 1a ′, a polyamide resin layer 1b, and a second polyester resin layer 1a ″. Consists of.

In a further aspect, as shown in FIG. 4, the transparent gas barrier film layer 1 is a layer made of an inorganic oxide vapor-deposited film, further having a vapor-deposited layer 1 c.
Further, as shown in FIG. 5, the sealant film layer 3 includes a first linear low density polyethylene layer 3b ′, a layer 3a made of nylon 6/12, and a second linear low density polyethylene layer 3b. It consists of three layers.

<II> Transparent gas barrier film layer In the present invention, the transparent gas barrier film used as a base film is at least a polyester resin layer having excellent high barrier properties and retort suitability, and a polyamide resin having excellent high barrier properties and impact resistance. It is preferable to have a biaxially stretched multilayer film obtained by biaxially stretching a multilayer film having a resin layer.

In the present invention, it is more preferable that an inorganic oxide is further vapor-deposited on the biaxially stretched multilayer film to provide a vapor-deposited layer to obtain an inorganic oxide vapor-deposited film.
In this inorganic oxide vapor-deposited film, in some cases, a gas barrier coating film may be provided on the vapor-deposited layer in order to further enhance the barrier property against oxygen gas and water vapor.

The biaxially stretched multilayer film can be obtained by dry laminating a polyester resin film and a polyamide resin film through an adhesive layer. Alternatively, both resins can be coextruded to form a film by multilayer coextrusion.
By using a multilayer coextruded film, it is possible to reduce the thickness and weight, which is preferable from the viewpoints of economy and consideration for the environment.

  In this configuration, the polyester-based resin layer serves as an outermost layer of the pouch manufactured using the packaging material of the present invention, imparting heat resistance to the surface, and providing stable heat sealability. In addition, the packaging bag is provided with hot water resistance, and plays a role of suppressing changes in appearance in the boil / retort treatment.

  In addition, the polyamide-based resin layer plays a role of improving the strength characteristics of the packaging material and the pouch made of the packaging material and giving impact resistance during transportation.

  Furthermore, it is preferable that the multilayer coextruded film is a biaxially stretched multilayer film having a first polyester resin layer, a polyamide resin layer, and a second polyester resin layer in this order. In the coextruded film, the contrast can prevent the film from curling.

In this configuration, the thickness of each layer includes the thickness of the first polyester resin layer (t ^{1aa ′} ), the thickness of the second polyester resin layer (t ^{1aa ″} ), and the thickness of the polyamide resin layer ( The relationship of t ^1ab ) satisfies t ^1ab / (t ^{1aa ′} + t ^{1aa ″} ) = 1 to 10, more preferably t ^1ab / (t ^{1aa ′} + t ^{1aa ″} ) = 2 to 5.

In this configuration, the first polyester resin layer serves as the outermost layer of the pouch manufactured using the packaging material of the present invention.
And the 2nd polyester system resin layer plays the role which acquires the favorable adhesiveness with respect to the base material of the vapor deposition layer provided on this 2nd polyester system resin layer.

In the present invention, the thickness of the biaxially stretched multilayer film is preferably about 6 to 100 μm, more preferably about 9 to 50 μm. Regarding the thickness relationship, t ^1ab / (t ^{1aa ′} + t ^{1aa ″} ), if this value is smaller than 1, the polyamide resin layer becomes thin and the required strength suitability cannot be obtained. On the other hand, if this value is greater than 10, the film formation suitability is lowered due to the thinness of the first and / or second polyester resin layer, and the polyamide resin layer becomes thicker than necessary. There is a disadvantage. Moreover, as thickness of a polyester-type resin layer, in order to maintain the function, it is preferable that it is 1-30 micrometers as thickness of each layer. The thickness of the polyamide resin layer is preferably 5 to 50 μm in order to retain its function.

(Polyester resin layer)
In the biaxially stretched multilayer film having the polyester resin layer and the polyamide resin layer, the polyester resin forming the polyester resin layer preferably contains a crystalline polyester as a main component.

  The crystalline polyester is not particularly limited as long as it can impart functions such as dimensional stability and heat resistance to the packaging material of the present invention. For example, a resin obtained by polycondensation of dicarboxylic acid and diol, etc. Is mentioned.

  Examples of the dicarboxylic acid include o-phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, and itaconic acid. , Decamethylene carboxylic acid, anhydrides and lower alkyl esters thereof, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, 3-sulfophthalic acid, dialkyl 5-sulfoisophthalate, 2-sulfoisophthalate Examples include dialkyl acid, dialkyl 4-sulfoisophthalate, dialkyl 3-sulfoisophthalate, and sulfo group-containing dicarboxylic acids such as sodium salts and potassium salts thereof.

  Examples of the diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, and tetraethylene glycol. 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5 -Aliphatic diols such as hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol; 2,2-bis (4 -Hydroxycyclohexyl) propane, 2,2-bis (4-hydroxycyclohex) E) Alkylene oxide adducts such as propane, alicyclic diols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, 1,3-dihydroxybutanesulfonic acid, 1,4-dihydroxybutanesulfonic acid, etc. And a sulfone group-containing diol.

Among these, in particular, polyethylene terephthalate (PET) in which the component derived from dicarboxylic acid is terephthalic acid and the component derived from diol is ethylene glycol; the components derived from dicarboxylic acid are terephthalic acid (99 to 80 mol%) and isophthalic acid ( 1-20 mol%), isophthalic acid copolymerized polyethylene terephthalate whose component derived from diol is ethylene glycol; polybutylene whose component derived from dicarboxylic acid is terephthalic acid and component derived from diol is 1,4-butanediol Terephthalate (PBT); the component derived from dicarboxylic acid is terephthalic acid (99.5 to 90 mol%) and 5-sodium sulfoisophthalic acid (0.5 to 10 mol%), and the component derived from diol is ethylene glycol Sulfoisophthalic acid copolymer polyester Such dimensional stability terephthalate, are preferred from the viewpoint of heat resistance and the like, more preferably a polyethylene terephthalate composed of terephthalic acid and ethylene glycol (PET).

Such crystalline polyesters are commercially available. For example, Belpet-EFG6C, Belpet PIFG5 (all manufactured by Bell Polyester Products Co., Ltd.) and the like are used as the crystalline polyester constituting the polyester resin layer. Can be used.
In addition, the crystalline polyester used for a polyester-type resin layer may be only 1 type, and may blend and use 2 or more types as needed.

  Further, the polyester resin layer may contain a resin compatible with the crystalline polyester as necessary, but the content of the crystalline polyester with respect to the total mass of the components constituting the polyester resin layer is 50 It is at least 70% by mass, preferably at least 70% by mass.

  Non-crystalline polyester etc. can be illustrated as resin compatible with crystalline polyester. An amorphous polyester is a polyester in which the heat of fusion is not observed in the differential scanning calorimetry based on JIS K7121. Although it will not specifically limit if it is polyester which has such a characteristic, As a specific example, the component derived from dicarboxylic acid is terephthalic acid, the component derived from diol is ethylene glycol (20-80 mol%) and cyclohexane dimethanol (80 Polyester having a component derived from dicarboxylic acid is preferably terephthalic acid (20 to 80 mol%) and isophthalic acid (80 to 20 mol%), and a polyester having a component derived from diol is ethylene glycol. is there. Such an amorphous polyester is commercially available. For example, Eastar Copolyester 6763 (manufactured by Eastman Chemical) or the like can be used as the amorphous polyester.

  Moreover, a well-known inorganic or organic additive etc. can be suitably mix | blended with a polyester-type resin layer as needed in the range which does not impair the effect of this invention. As an inorganic or organic additive, an antiblocking agent, a nucleating agent, a water repellent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a colorant, a pigment, a dye, and the like can be appropriately blended.

(Polyamide resin layer)
In the biaxially stretched multilayer film having the polyester resin layer and the polyamide resin layer, the polyamide resin layer imparts functions such as bending resistance and impact resistance to the packaging material of the present invention. In particular, the provision of bending resistance can suppress a decrease in gas barrier properties after bending.
The polyamide resin layer contains an aliphatic polyamide and an aromatic polyamide.

(Aliphatic polyamide)
Examples of the aliphatic polyamide include aliphatic nylon and copolymers thereof. Specifically, polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid (nylon-9), polyundecanamide (nylon-11), polylauryllactam ( Nylon-12), polyethylenediamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylene Bacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), polydecamethylene adipamide (nylon-10,8) , Caprolactam / lauryl lactam copolymer (nylon-6 / 12), caprolactam / ω-aminononanoic acid copolymer Body (nylon-6 / 9), caprolactam / hexamethylenediammonium adipate copolymer (nylon-6 / 6,6), lauryllactam / hexamethylenediammonium adipate copolymer (nylon-12 / 6,6), Ethylenediamine adipamide / hexamethylene diammonium adipate copolymer (nylon-2,6 / 6,6), caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon-6 / 6,6) / 6,10), ethyleneammonium adipate / hexamethylenediammonium adipate / hexamethylenediammonium sebacate copolymer (nylon-6 / 6,6 / 6,10), etc. Even if you mix the aliphatic polyamide There.

  Preferred aliphatic polyamides include nylon-6, nylon-6,6, nylon-6 / 6,6 (copolymer of nylon 6 and nylon 6,6), more preferably nylon-6, nylon. -6/6, 6 and more preferably nylon-6. As the two or more kinds of aliphatic polyamides, a combination of nylon-6 and nylon-6 / 6,6 (mass ratio of about 50:50 to 95: 5) is preferable.

(Aromatic polyamide)
As the aromatic polyamide, for example, an aromatic diamine such as metaxylenediamine and paraxylenediamine and a dicarboxylic acid such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid, or a derivative thereof can be used. Examples thereof include crystalline aromatic polyamides obtained by a condensation reaction. A crystalline aromatic polyamide such as polymetaxylene adipamide (MXD-nylon) is preferable. Specific examples include S-6007 and S-6011 (both manufactured by Mitsubishi Gas Chemical Co., Inc.).

  Alternatively, an amorphous aromatic polyamide (amorphous nylon) obtained by a polycondensation reaction between an aliphatic diamine such as hexamethylenediamine and a dicarboxylic acid such as terephthalic acid or isophthalic acid or a derivative thereof can be used. Preferred is a copolymer of hexamethylenediamine-terephthalic acid-hexamethylenediamine-isophthalic acid. Specific examples include sealer PA (manufactured by Mitsui DuPont Polychemical Co., Ltd.) and the like.

  As the polyamide-based resin layer of the present invention, preferable combinations of aliphatic polyamide and aromatic polyamide include a combination of nylon-6 and MXD-nylon, and a combination of nylon-6 and amorphous aromatic polyamide (amorphous nylon). .

(Content)
In the present invention, in the polyamide resin layer, the content of the aliphatic polyamide and the aromatic polyamide is 70 to 99% by mass for the aliphatic polyamide, preferably 85 to 97% by mass, 1 to 30% by mass for the aromatic polyamide, Preferably, it is adjusted so as to be contained at a ratio of 3 to 15% by mass. When the amount of the aliphatic polyamide is more than 99% by mass, when the amount of the aromatic polyamide is less than 1% by mass, the biaxial stretchability is lowered, and the film is difficult to be formed. On the other hand, when the aliphatic polyamide is less than 70% by mass, when the aromatic polyamide is more than 30% by mass, the bending resistance is lowered.

  The polyamide-based resin layer may be composed of the above-mentioned polyamide-based resin, but if necessary, blends a known flex resistance improver, an inorganic or organic additive, etc. as long as the effects of the present invention are not impaired. can do. Examples of the bending resistance improver include polyolefins, polyester elastomers, polyamide elastomers, and the like, and they can be appropriately blended in the range of about 0.5 to 10% by mass. Examples of inorganic or organic additives include antiblocking agents, nucleating agents, water repellents, antioxidants, thermal stabilizers, lubricants, antistatic agents, and the like. For example, if it is an antiblocking agent, a silica, a talc, a kaolin etc. can be mix | blended suitably in the range of about 100-5000 ppm. Note that it is possible to provide not only one polyamide-based resin layer but also two or more layers.

(Film formation)
In the biaxially stretched multilayer film having the polyester resin layer and the polyamide resin layer, the layers and the adhesive resin layer are laminated by coextrusion so as to have the above-described layer configuration. For example, the resin of each layer is extruded at a temperature of 200 ° C. to 300 ° C., and co-extruded on a chill roll of 20 ° C. to 40 ° C. in which cooling water circulates from a T die so as to be in the order of each layer. obtain. The obtained film was stretched longitudinally 2 to 4 times by a roll stretching machine at 50 to 100 ° C., and further stretched 3 to 5 times by a tenter stretching machine in an atmosphere at 90 to 150 ° C., and subsequently the same tenter. It can obtain by heat-processing in 100-240 degreeC atmosphere and cooling. The multilayer stretched film of the present invention may be subjected to simultaneous biaxial stretching and sequential biaxial stretching, and the obtained multilayer stretched film may be provided with any surface treatment layer on both surfaces or one surface if necessary. Good.

  In the present invention, as the surface treatment layer, for example, corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, pretreatment such as oxidation treatment using chemicals, etc. For example, a corona treatment layer, an ozone treatment layer, a plasma treatment layer, an oxidation treatment layer, or the like can be formed and provided.

  The surface pretreatment is carried out as a method for improving the close adhesion between various resin films and inorganic oxide vapor deposition films, etc., but as a method for improving the above close adhesion, In addition, for example, on the surface of various resin films, a primer coat agent layer, an undercoat agent layer, an anchor coat agent layer, an adhesive layer, or a deposition anchor coat agent layer is optionally formed in advance. It can also be a treatment layer.

  Examples of the pretreatment coating agent layer include polyester resins, polyamide resins, polyurethane resins, epoxy resins, phenol resins, (meth) acrylic resins, polyvinyl acetate resins, polyethylene, and polypropylene. A resin composition comprising a main component of a vehicle such as a polyolefin resin or a copolymer or modified resin thereof, a cellulose resin, or the like can be used.

(Deposition layer)
The vapor deposition layer laminated | stacked on said biaxial stretching multilayer film in this invention is demonstrated.
The material for forming the vapor deposition layer may be any material having transparency and gas barrier properties such as oxygen and water vapor. For example, silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide Boron oxide, hafnium oxide, barium oxide, and the like, and in particular, any of silicon oxide, aluminum oxide, and magnesium oxide is preferable from the viewpoint of gas barrier properties and production efficiency.
As a formation method of a vapor deposition layer, it can form by a chemical vapor deposition method or a physical vapor deposition method.

  Moreover, the vapor deposition layer may consist of a single layer formed by one vapor deposition process, or may have a multilayer structure formed by repeating the vapor deposition process a plurality of times. In the case of a multilayer structure, each layer may be made of the same material or different materials, and may be formed by the same forming method or by different forming methods. Good. For example, a vapor deposition film made of silicon oxide may be formed on a biaxially stretched multilayer film by chemical vapor deposition, and then a vapor deposition film made of aluminum oxide may be formed by physical vapor deposition.

  The layer thickness of the vapor deposition layer can be appropriately set in the range of 5 to 100 nm, more preferably 10 to 50 nm, as the thickness of the entire layer. If it exceeds 100 nm, the flexibility will be reduced, and the deposited layer may be cracked by external forces such as bending and pulling after film formation, transparency may be reduced, and the stress of the material itself will increase. Coloring is not preferable. On the other hand, if the thickness exceeds 100 nm, productivity is remarkably lowered, and further, protrusions tend to be formed due to abnormal grain growth, which is not preferable. On the other hand, when the thickness of the inorganic compound layer is less than 5 nm, the transparency is good, but it is difficult to obtain a uniform layer and it is difficult to sufficiently perform the gas barrier function.

(Gas barrier coating film)
By forming a vapor-deposited layer on the biaxially stretched multilayer film and further providing a gas barrier coating film on the vapor-deposited layer, not only a better gas barrier property can be obtained, but also a close contact with the adhesive layer. Wearability is enhanced and higher gas barrier properties can be obtained.
In the present invention, the gas barrier coating film is a film obtained by applying and drying a gas barrier composition obtained by polycondensation of an alkoxide and a water-soluble polymer by a sol-gel method.

The alkoxide used in the gas barrier composition has a general formula R ¹ nM (OR ² ) m (wherein M represents a metal atom, R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, n Is an integer of 0 or more, m is an integer of 1 or more, and n + m represents an atomic valence of M).
As the water-soluble polymer, either polyvinyl alcohol or ethylene / vinyl alcohol or both can be preferably used.

In the present invention, as the alkoxide represented by the general formula R ¹ _n M (OR ² ) _m , silicon, zirconium, titanium, aluminum or the like can be used as the metal atom M. Moreover, in this invention, the alkoxide of a single or 2 or more types of different metal atoms can be mixed and used in the same solution.

In the alkoxide represented by the general formula R ¹ _n M (OR ² ) _m , specific examples of the organic group represented by R ¹ include, for example, a methyl group, an ethyl group, an n-propyl group, i Examples include -propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group and other alkyl groups.

In the alkoxide represented by the general formula R ¹ _n M (OR ² ) _m , specific examples of the organic group represented by R ² include, for example, a methyl group, an ethyl group, an n-propyl group, i -Propyl group, n-butyl group, sec-butyl group and the like.
In the present invention, these alkyl groups may be the same or different in the same molecule.

In the present invention, as the alkoxide represented by the general formula R ¹ _n M (OR ² ) _m , for example, an alkoxysilane in which M is Si can be used. As the alkoxysilane, for example, tetramethoxy Examples thereof include silane Si (OCH ₃ ) ₄ , tetraethoxysilane Si (OC ₂ H ₅ ) ₄ , tetrapropoxysilane Si (OC ₃ H ₇ ) ₄ , tetrabutoxysilane Si (OC ₄ H ₉ ) _{4 and the} like.

  Moreover, in this invention, it is preferable that content of polyvinyl alcohol and / or ethylene vinyl alcohol is the range of 5-500 mass parts with respect to 100 mass parts of total amounts of said alkoxide. In the above, when it exceeds 500 mass parts, since the brittleness of the gas barrier coating film formed becomes large, it is not preferable.

  In the present invention, polyvinyl alcohol generally obtained by saponifying polyvinyl acetate can be used. Specific examples of polyvinyl alcohol include Kuraray Co., Ltd. PVA110 (degree of saponification = 98 to 99%, degree of polymerization = 1100), PVA117 (degree of saponification = 98 to 99%, degree of polymerization = 1700), PVA124 (saponification). Degree = 98-99%, degree of polymerization = 2400), PVA135H (degree of saponification = 99.7% or more, degree of polymerization = 3500), RS-110 (degree of saponification = 99%, polymerization) manufactured by the same company Kuraraypoval LM-20SO (degree of saponification = 40%, degree of polymerization = 2,000), Gohsenol NM-14 (degree of saponification = 99%) manufactured by Nippon Synthetic Chemical Industry Co., Ltd. , Degree of polymerization = 1,400) and gohsenol NH-18 (degree of saponification = 98 to 99%, degree of polymerization = 1700) and the like can be used.

  In the present invention, a saponified product of a copolymer of ethylene and vinyl acetate, that is, a product obtained by saponifying an ethylene-vinyl acetate random copolymer can be used as the ethylene / vinyl alcohol. Such saponification products include partial saponification products in which several tens mol% of acetic acid groups remain to complete saponification products in which only several mol% of acetic acid groups remain or no acetic acid groups remain. The Although not particularly limited, it is desirable to use a saponification degree of 80 mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol% or more from the viewpoint of gas barrier properties. The content of the repeating unit derived from ethylene in the ethylene / vinyl alcohol (hereinafter also referred to as “ethylene content”) is usually 0 to 50 mol%, preferably 20 to 45 mol%. It is preferable. Specific examples of the ethylene vinyl alcohol include Kuraray Co., Ltd., Eval EP-F101 (ethylene content; 32 mol%), Nippon Synthetic Chemical Industry Co., Ltd., Soarnol D2908 (ethylene content; 29 mol%), and the like. Can be used.

  In the present invention, a silane coupling agent or the like can also be added to prepare a gas barrier composition for forming a gas barrier coating film according to the present invention. Suitable silane coupling agents include N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2- Amino group-containing silane coupling agents such as aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 2 -Epoxy group-containing silanes such as (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane Coupling agent, 3-mercaptopro Examples include mercapto group-containing silane coupling agents such as rumethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane, and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane and 3-isocyanatopropyltrimethoxysilane. .

The gas barrier composition used in the present invention can be prepared by hydrolyzing and polycondensing an alkoxide and a water-soluble polymer by a sol-gel method in the presence of an acid, water and an organic solvent.
The gas barrier coating film is formed by applying the gas barrier composition on the vapor deposition layer, and is 20 ° C. to 200 ° C., preferably 140 ° C. or more, and at a temperature not higher than the melting point of the plastic film constituting the base material layer for 10 seconds to It can be formed by heat treatment for 10 minutes.

  Moreover, as an acid used in preparation of said gas-barrier composition, organic acids, such as mineral acids, such as a sulfuric acid, hydrochloric acid, nitric acid, and an acetic acid, tartaric acid, etc. can be used, for example. Furthermore, as the organic solvent, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, or the like can be used.

  Furthermore, regarding the gas barrier composition, the polyvinyl alcohol and / or ethylene / vinyl alcohol is preferably in a state dissolved in a coating solution containing the alkoxide, the silane coupling agent, or the like. The kind of solvent is appropriately selected. In the present invention, as the ethylene / vinyl alcohol solubilized in a solvent, for example, those commercially available as Soarnol (manufactured by Nippon Synthetic Chemical Co., Ltd.) can be used.

  When the gas barrier composition is applied onto the vapor deposition layer and heated to remove the solvent and the alcohol produced by the polycondensation reaction, the polycondensation reaction is completed, and a transparent gas barrier coating film is formed.

  Furthermore, since the hydroxyl group generated by hydrolysis and the silanol group derived from the silane coupling agent are bonded to the hydroxyl group on the surface of the vapor deposition layer, the adhesion between the vapor deposition layer and the gas barrier coating film is good. .

  By being formed as described above, the gas barrier coating film of the present invention includes a linear polymer having crystallinity and has a structure in which a large number of minute crystals are embedded in an amorphous portion. . Such a crystal structure is the same as that of a crystalline organic polymer (for example, vinylidene chloride or polyvinyl alcohol), and a polar group (OH group) is partially present in the molecule, and the cohesive energy of the molecule is high. Good surface gas barrier properties.

  In the present invention, the vapor deposition layer and the gas barrier coating film form, for example, a chemical bond, hydrogen bond, or coordination bond by hydrolysis / co-condensation, and the adhesion between these two layers is improved. According to the effect, a better surface gas barrier property can be exhibited.

  In the present invention, the gas barrier composition may be applied by one or more times by a coating means such as a roll coat such as a gravure roll coater, a spray coat, dipping, a brush, a bar coat, or an applicator. With this coating, a gas barrier coating film having a dry film thickness of 0.01 to 30 μm, preferably 0.1 to 10 μm can be formed.

  In the present invention, in order to obtain a higher surface gas barrier property, after providing a gas barrier coating film, a vapor deposition layer and a gas barrier coating film are alternately laminated in this order one or more times alternately. Preferably, the gas barrier coating film may be formed as an outermost layer to form a transparent gas barrier film.

Since the transparent gas barrier film of the present invention is particularly excellent in gas barrier properties (O ₂ , N ₂ , H ₂ O, CO _2, etc.), it is suitably used as a food packaging film. In particular, when used in so-called gas-filled packaging filled with N ₂ or CO ₂ gas, the excellent gas barrier property is extremely effective for holding the filled gas.

  Furthermore, the transparent gas barrier film of the present invention is also excellent in gas barrier properties after hot water treatment, particularly high-pressure hot water treatment (retort treatment).

<III> Adhesive layer In the present invention, the adhesive constituting the adhesive layer is, for example, a polyvinyl acetate adhesive, a homopolymer such as ethyl acrylate, butyl acrylate, 2-ethylhexyl ester, or the like. And polyacrylic acid ester adhesives composed of copolymers of methyl methacrylate, acrylonitrile, styrene, etc., cyanoacrylate adhesives, ethylene and vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid and other monomers Ethylene copolymer adhesive made of copolymer, cellulose adhesive, polyester adhesive, polyamide adhesive, polyimide adhesive, amino resin adhesive made of urea resin or melamine resin, phenol resin Adhesive, epoxy adhesive, polyurethane adhesive, reactive type (meta) Uses adhesives such as rubber adhesives made of kryl adhesive, chloroprene rubber, nitrile rubber, styrene-butadiene rubber, etc., silicone adhesives, alkali metal silicates, inorganic adhesives made of low melting glass, etc. be able to.

  The above-mentioned adhesive may be in any form of composition such as aqueous type, solution type, emulsion type, and dispersion type, and the property may be any form such as film / sheet, powder or solid. Further, the adhesion mechanism may be any form such as a chemical reaction type, a solvent volatilization type, a heat melting type, and a hot pressure type.

In the present invention, the adhesive is applied to the entire surface of the transparent gas barrier film layer by, for example, a coating method such as a roll coating method, a gravure roll coating method, a kiss coating method, or a printing method, and then a solvent or the like. Can be dried to form an adhesive layer, and the coating or coating amount is preferably about 0.1 to 10 g / m ² (dry state).

<IV> Sealant film layer In the packaging material of the present invention, the sealant film is melted by heat and fused to each other, and in addition to excellent adhesiveness and hot water resistance to withstand retort processing, it further has low resistance to the packaging material of the present invention. It has a function of imparting dissolution properties.
In order to satisfy all these properties, in the packaging material of the present invention, the sealant film layer has at least a linear low-density polyethylene layer.

  In particular, a multilayer coextruded film having a linear low density polyethylene layer and a layer made of nylon 6/12 is preferred because the effect of giving low elution property to the packaging material of the present invention is enhanced. Here, the linear low-density polyethylene layer forms a liquid contact surface of the packaging material of the present invention, and exhibits stable heat sealability as the innermost layer of the pouch produced using the packaging material of the present invention. .

  In the present invention, in particular, the content of unreacted residual ε-caprolactam contained in the nylon 6/12 layer is 0.8% by mass or less, and unreacted residual ω-laurolactam It is preferable to use the multilayer coextruded film having a content of 0.1% by mass or less.

  Furthermore, in the single-sided dissolution test carried out in accordance with FDA (US Food and Drug Administration) § 177/1500 13.2 standard test (nylon 6/12), on the surface of the sealant film layer of the packaging material of the present invention, When a sufficient amount of 95% ethanol was brought into contact and heated at 121 ° C. for 2 hours, the masses of unreacted residual ε-caprolactam and ω-laurolactam eluted in the 95% ethanol were respectively measured in the sealant film layer 1. It is preferable to use the above multilayer coextruded film that is 0.15 mg or less and 0.04 mg or less per square inch.

  As a packaging material for boil treatment, in the same manner, in a single-side elution test, when a sufficient amount of water is brought into contact with the surface of the sealant film layer of the packaging material of the present invention and extracted at room temperature (23 ° C.) for 5 hours, Use of the multilayer coextruded film, wherein the masses of unreacted residual ε-caprolactam and ω-laurolactam eluted in water are 0.15 mg or less and 0.04 mg or less per square inch of the sealant film layer, respectively. preferable.

  In addition, as a packaging material for boil treatment, in a single-side elution test, when a sufficient amount of water is brought into contact with the surface of the sealant film layer of the packaging material of the present invention and extracted at 100 ° C. for 8 hours, It is preferable to use the multilayer coextruded film in which the mass of nitrogen eluted in water is 15 mg or less per square centimeter of the sealant film layer and 100 μg or less per square inch.

  The multilayer coextruded film of the present invention having the above-described structure is composed of a linear low density polyethylene layer exhibiting excellent heat sealability and hot water resistance, and a layer made of nylon 6/12 that provides low elution to the packaging material of the present invention. Are formed by multilayer coextrusion.

  A multilayer coextruded film having a linear low density polyethylene layer and a layer made of nylon 6/12, which is used as a sealant film in the present invention, itself has a low content of eluting chemicals, It has an excellent shielding ability against the eluting chemical substances contained in the transparent gas barrier film layer and the adhesive layer, and prevents migration into these contents. Further, it can be made thinner and lighter, which is preferable from the viewpoints of economy and consideration for the environment.

  In a further aspect, the multilayer coextruded film has a first linear low density polyethylene layer, a layer made of nylon 6/12, and a second linear low density polyethylene layer in this order. It is preferable that In the coextruded film, the contrast can prevent the film from curling. The second linear low-density polyethylene layer plays a role of enhancing the adhesion between the adhesive layer and the sealant film layer.

  The thickness of each layer of the multilayer coextruded film can be arbitrarily determined by those skilled in the art within the range in which the role of each layer is fulfilled, but each linear low density polyethylene layer is, for example, about 5 to 100 μm / layer, and The layer made of nylon 6/12 can be set to about 5 to 50 μm.

In the present invention, the linear low density polyethylene has a density of 0.910 to 0.925 g / obtained by polymerizing an ethylene monomer using a polymerization method such as a low pressure method, a slurry method, a solution method, or a gas phase method. cm ³ linear polyethylene. In the present invention, those having arbitrary physical properties can be used as long as the effects are not impaired, but linear low-density polyethylene prepared with a metallocene catalyst is preferably used in terms of excellent structural uniformity. be able to. In the linear low density polyethylene layer, known inorganic or organic additives can be appropriately blended as necessary.

  In the present invention, nylon 6/12 constituting a layer made of nylon 6/12 is produced by copolymerization of ε-caprolactam and ω-laurolactam. The ratio of these comonomers can be appropriately set by those skilled in the art depending on the application, and ε-caprolactam: ω-laurolactam is preferably, for example, 50:50 to 95: 5 (mass ratio), or, for example, 50:50. A copolymer of (mass ratio) and a copolymer of 80% by mass or more and less than 20% by mass can also be suitably used. In the present invention, 6/69 nylon can be used instead of nylon 6/12.

<V> Packaging material The packaging material of this invention is manufactured by laminating | stacking said transparent gas barrier film and a sealant film through an adhesive bond layer so that it may become the above-mentioned layer structure.
In the present invention, the sealant film is dry-laminated on the adhesive layer laminated on the transparent gas barrier film layer.

  If necessary, another resin film (intermediate layer) may be sandwiched between the adhesive layer and the sealant film layer. By providing such an intermediate layer, strength, puncture resistance, and the like are improved. As a resin film, it has excellent strength in mechanical, physical, chemical, etc., excellent in puncture resistance, etc. In addition, it is excellent in heat resistance, moisture resistance, pinhole resistance, transparency, etc. The film can be used.

  Specifically, for example, a polyester resin, a polyamide resin, a polyaramid resin, a linear low density polyethylene resin, a polycarbonate resin, a polyacetal resin, a fluorine resin, or other tough resin film should be used. Can do.

  In the present invention, the above-mentioned resin film is used, and this may be sandwiched between the adhesive layer and the sealant film layer using the above-described adhesive or the like using a dry laminating method or the like. it can.

As the resin film, any of an unstretched film or a stretched film stretched in a uniaxial direction or a biaxial direction can be used. In the present invention, the thickness of the resin film may be a thickness that can be kept to the minimum necessary for strength, puncture resistance, and the like. On the other hand, if it is too thin, the strength, puncture resistance and the like are reduced, which is not preferable. In addition, since the transparent gas barrier film has a polyamide-based resin layer, it has excellent impact strength and puncture resistance, so it should be used to the minimum necessary in consideration of environmental considerations. .
The packaging material of the present invention exhibits excellent low elution properties.

  Specifically, the packaging material of the present invention is a non-volatile material that elutes into the water when the surface of the sealant layer is brought into contact with a sufficient amount of deionized distilled water and heated at 121 ° C. for 2 hours in the dissolution test. The chloroform-soluble mass of the sex extract is no greater than 0.016 mg per square centimeter of sealant film layer and no greater than 0.10 mg per square inch.

  Similarly, when the surface of the sealant layer is brought into contact with a sufficient amount of deionized distilled water and heated at 135 ° C. for 1 hour, the mass of the eluate eluted into the water is about 1 cm 2 of the sealant film layer. 0.008 mg or less and 0.05 mg or less per square inch.

<VI> Pouch It is possible to produce a pouch that can be suitably used for boil and retort processing by stacking the packaging material of the present invention so that the sealant film layer is the innermost layer.

  As the bag making method, the packaging material of the present invention is folded or overlapped so that the surface of the sealant layer is opposed, and the peripheral end portion thereof is, for example, a side seal type, a two-side seal type, or a three-side seal type. , Four-side seal type, envelope-sealed seal type, joint-sealed seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, gusset type, etc. Pouches can be manufactured. In addition, for example, a self-supporting packaging bag (standing pouch) is also possible.

  In the above, the heat sealing method can be performed by a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, an ultrasonic seal, and the like.

  The pouch of the present invention exhibits excellent low elution properties. Specifically, in a dissolution test peculiar to retort products carried out in accordance with FDA (US Food and Drug Administration) § 177/1390 standard test, the surface of the sealant layer is brought into contact with a sufficient amount of deionized distilled water. The mass of the eluate eluted into the deionized distilled water when heated at 135 ° C. for 1 hour is 0.05 mg or less per square inch of the sealant film layer.

Although the present invention will be described more specifically with reference to examples, the present invention is not limited to these examples. Also use the following abbreviations:
PET: Polyethylene terephthalate NY: Nylon LLDPE: Linear low density polyethylene

[Example 1]
As a transparent barrier layer, a multilayer stretched film (manufactured by Gunze Co., Ltd.) having a three-layer structure of PET / NY / PET is used as a base layer of the transparent barrier layer, and an inorganic silica oxide vapor deposition film is formed by a chemical vapor deposition method. On the transparent barrier layer on which an organic / inorganic barrier layer having barrier properties is formed, LLDPE is provided via an adhesive layer. The final layer structure was 15 μm transparent deposition (PET 1.5 μ · NY 12 μ · PET 1.5 μ) / adhesive layer 3 μm / LLDPE 70 μm. As the adhesive, a polyester adhesive RU004 / H-1 manufactured by Rock Paint was used. LR-124 manufactured by Okamoto Co., Ltd. was used as the sealant LLDPE.
The layer-constituting film was cut in a longitudinal direction of 13 cm and a width direction of 18 cm, and a three-sided seal was performed to produce a flat pouch. Next, 150 ml of deionized distilled water was filled and heat-sealed at 180 ° C., and then subjected to pressurization and overheating sterilization at 121 ° C. for 30 minutes in a hot water retort sterilizer. After cooling at room temperature, the weight of the eluate in deionized distilled water was measured and found to be 0.005 mg / cm ² in terms of a converted value.

[Example 2]
As a transparent barrier layer, a multilayer stretched film (manufactured by Gunze Co., Ltd.) having a three-layer structure of PET / NY / PET is used as a base layer of the transparent barrier layer, and an inorganic silica oxide vapor deposition film is formed by a chemical vapor deposition method. On top of that, the transparent barrier layer formed with an organic / inorganic barrier layer having a barrier property has a multilayer sealant having a three-layer structure of LLDPE / 6,12 nylon / LLDPE through an adhesive layer, In 12 nylon, a nylon 6/12 resin having a residual ε-caprolactam of 0.5 wt% and a residual ω laurolactam of 0.03 wt% or less was used. When a single-sided extraction test of 95% ethanol and 121 ° C. for 2 hours was performed on the multilayer sealant alone, the elution amount of ε-caprolactam was not more than 0.10 mg / square inch and the extraction amount of ω laurolactam was 0.02 mg / square inch. It was. The final layer structure was transparent deposition (PET 1.5 μ · NY 12 μ · PET 1.5 μ) 15 μ / adhesive layer 3 μ / (LLDPE · 6,12 nylon · LLDPE) 70 μ. As the adhesive, a polyester adhesive RU004 / H-1 manufactured by Rock Paint was used. LR-124 manufactured by Okamoto Co., Ltd. was used as the sealant LLDPE.
The layer-constituting film was cut in a longitudinal direction of 13 cm and a width direction of 18 cm, and a three-sided seal was performed to produce a flat pouch. Next, 150 ml of deionized distilled water was filled and heat-sealed at 180 ° C., and then subjected to pressurization and overheating sterilization at 121 ° C. for 30 minutes in a hot water retort sterilizer. After cooling at room temperature, the weight of the eluate in deionized distilled water was measured and found to be 0.003 mg / cm ² in terms of converted value.

[Example 3]
As a transparent barrier layer, a multilayer stretched film (manufactured by Gunze Co., Ltd.) having a three-layer structure of PET / NY / PET is used as a base layer of the transparent barrier layer, and an inorganic silica oxide vapor deposition film is formed by a chemical vapor deposition method. On top of that, a transparent barrier layer formed with an organic / inorganic barrier layer having a barrier property has a multilayer sealant having a two-layer structure of 6,12 nylon / LLDPE through an adhesive layer. Used a nylon 6/12 resin having a residual ε-caprolactam of 0.5 wt% and a residual ω laurolactam of 0.03 wt% or less. When a single-sided extraction test of 95% ethanol and 121 ° C. for 2 hours was performed on the multilayer sealant alone, the elution amount of ε-caprolactam was not more than 0.10 mg / square inch and the extraction amount of ω laurolactam was 0.02 mg / square inch. It was. The final layer structure was transparent deposition (PET 1.5 μ · NY 12 μ · PET 1.5 μ) 12 μ / adhesive layer 3 μ / (6,12 nylon · LLDPE) 70 μ. As the adhesive, a polyester adhesive RU004 / H-1 manufactured by Rock Paint was used. LR-124 manufactured by Okamoto Co., Ltd. was used as the sealant LLDPE.
The layer-constituting film was cut in a longitudinal direction of 13 cm and a width direction of 18 cm, and a three-sided seal was performed to produce a flat pouch. Next, 150 ml of deionized distilled water was filled and heat-sealed at 180 ° C., and then subjected to pressurization and overheating sterilization at 121 ° C. for 30 minutes in a hot water retort sterilizer. After cooling at room temperature, the weight of the eluate in deionized distilled water was measured and found to be 0.003 mg / cm ² in terms of converted value.

[Example 4]
As the transparent barrier layer, a multilayer stretched film (manufactured by Gunze Co., Ltd.) having a two-layer structure of PET / NY is used as the base layer of the transparent barrier layer, and an inorganic silica oxide vapor deposition film is formed by chemical vapor deposition. In addition, the transparent barrier layer on which the organic / inorganic barrier layer having a barrier property is formed has LLDPE through an adhesive layer. The final layer configuration was transparent deposition (PET 3μ · NY12μ) 15μ / adhesive layer 3μ / LLDPE 70μ. As the adhesive, a polyester adhesive RU004 / H-1 manufactured by Rock Paint was used. LR-124 manufactured by Okamoto Co., Ltd. was used as the sealant LLDPE.
The layer-constituting film was cut in a longitudinal direction of 13 cm and a width direction of 18 cm, and a three-sided seal was performed to produce a flat pouch. Next, 150 ml of deionized distilled water was filled and heat-sealed at 180 ° C., and then subjected to pressurization and overheating sterilization at 121 ° C. for 30 minutes in a hot water retort sterilizer. After cooling at room temperature, the weight of the eluate in deionized distilled water was measured and found to be 0.005 mg / cm ² in terms of a converted value.

[Example 5]
As the transparent barrier layer, a multilayer stretched film (manufactured by Gunze Co., Ltd.) having a two-layer structure of PET / NY is used as the base layer of the transparent barrier layer, and an inorganic silica oxide vapor deposition film is formed by a chemical vapor deposition method. In addition, the transparent barrier layer on which the organic / inorganic barrier layer having barrier properties is formed has a multilayer sealant having a three-layer structure of LLDPE / 6,12 nylon / LLDPE via an adhesive layer, and the 6,12 nylon Used a nylon 6/12 resin having a residual ε-caprolactam of 0.5 wt% and a residual ω laurolactam of 0.03 wt% or less. When a single-sided extraction test of 95% ethanol and 121 ° C. for 2 hours was performed on the multilayer sealant alone, the elution amount of ε-caprolactam was not more than 0.10 mg / square inch and the extraction amount of ω laurolactam was 0.02 mg / square inch. It was. The final layer configuration was 15 μm transparent vapor deposition (PET 3 μ · NY 12 μ) / 2 μm adhesive layer / (LLDPE · 6,12 nylon · LLDPE) 70 μm. As the adhesive, a polyester adhesive RU004 / H-1 manufactured by Rock Paint was used. LR-124 manufactured by Okamoto Co., Ltd. was used as the sealant LLDPE.
The layer-constituting film was cut in a longitudinal direction of 13 cm and a width direction of 18 cm, and a three-sided seal was performed to produce a flat pouch. Next, 150 ml of deionized distilled water was filled and heat-sealed at 180 ° C., and then subjected to pressurization and overheating sterilization at 121 ° C. for 30 minutes in a hot water retort sterilizer. After cooling at room temperature, the weight of the eluate in deionized distilled water was measured and found to be 0.003 mg / cm ^{2 in} terms of a converted value.

[Example 6]
As the transparent barrier layer, a multilayer stretched film (manufactured by Gunze Co., Ltd.) having a two-layer structure of PET / NY is used as the base layer of the transparent barrier layer, and an inorganic silica oxide vapor deposition film is formed by a chemical vapor deposition method. In addition, the transparent barrier layer formed with an organic / inorganic barrier layer having a barrier property has a multilayer sealant of 6,12 nylon / LLDPE through an adhesive layer, and in the 6,12 nylon, A nylon 6/12 resin having a residual ε caprolactam of 0.5 wt% and a residual ω laurolactam of 0.03 wt% or less was used. When a single-sided extraction test of 95% ethanol and 121 ° C. for 2 hours was performed on the multilayer sealant alone, the elution amount of ε-caprolactam was not more than 0.10 mg / square inch and the extraction amount of ω laurolactam was 0.02 mg / square inch. It was. The final layer configuration was 15 μm transparent vapor deposition (PET 3 μ · NY12 μ) / 3 μm adhesive layer / (6,12 nylon · LLDPE) 70 μm. As the adhesive, a polyester adhesive RU004 / H-1 manufactured by Rock Paint was used. LR-124 manufactured by Okamoto Co., Ltd. was used as the sealant LLDPE.
The layer-constituting film was cut in a longitudinal direction of 13 cm and a width direction of 18 cm, and a three-sided seal was performed to produce a flat pouch. Next, 150 ml of deionized distilled water was filled and heat-sealed at 180 ° C., and then subjected to pressurization and overheating sterilization at 121 ° C. for 30 minutes in a hot water retort sterilizer. After cooling at room temperature, the weight of the eluate in deionized distilled water was measured and found to be 0.003 mg / cm ² in terms of converted value.

[Evaluation]
For the packaging materials of Examples 1 to 6 above, the dissolution test is carried out under the conditions according to the classification and use conditions of the contents in accordance with the FDA (US Food and Drug Administration) § 176/170 (c) standard test The surface of the sealant layer is brought into contact with a sufficient amount of water, and when heated at 121 ° C. for 2 hours, the mass of the eluate eluted into the water, and similarly, the surface of the sealant layer is contacted with a sufficient amount of heptane at The mass of the eluate eluted into the heptane when heated for 2 hours was measured.

Further, for the pouches made from the packaging materials of Examples 1 to 6 above, the surface of the sealant layer in the dissolution test peculiar to retort products carried out in accordance with FDA (US Food and Drug Administration) § 177/1390 standard test. The mass of the eluate eluted into the deionized distilled water when it was brought into contact with a sufficient amount of deionized distilled water and heated at 135 ° C. for 1 hour was measured.
The results are shown in Table 1 below.

1. Transparent gas barrier film layer 1a. Polyester resin layer 1a '. First polyester resin layer 1a ''. Second polyester resin layer 1b. Polyamide-based resin layer 1c. 1. Deposition layer 2. Adhesive layer Sealant film layer 3a. Layer 3b of nylon 6/12. Linear low density polyethylene layer 3b '. First linear low density polyethylene layer 3b ''. Second linear low density polyethylene layer

Claims (12)

In a packaging material having at least a transparent gas barrier film layer, an adhesive layer, and a sealant film layer in this order,
The transparent gas barrier film layer is a layer having a biaxially stretched multilayer film obtained by biaxially stretching a multilayer film having at least a polyester resin layer and a polyamide resin layer,
The sealant film layer is a layer made of a multilayer coextruded film comprising at least a linear low density polyethylene layer and a layer made of nylon 6/12,
The linear low density polyethylene layer is a packaging material for boil / retort treatment , which is a layer forming a liquid contact surface of the packaging material. The layer of nylon 6/12 has an unreacted residual ε-caprolactam content of 0.8% by mass or less, and an unreacted residual ω-laurolactam content of 0.1% by mass or less. And
In the single-sided dissolution test, when a sufficient amount of 95% ethanol was brought into contact and heated at 121 ° C. for 2 hours, the masses of the unreacted residual ε-caprolactam and ω-laurolactam eluted in the 95% ethanol were respectively The packaging material for boil / retort treatment according to claim 1, wherein the sealant film layer is 0.15 mg or less and 0.04 mg or less per square inch. The layer of nylon 6/12 has an unreacted residual ε-caprolactam content of 0.8% by mass or less, and an unreacted residual ω-laurolactam content of 0.1% by mass or less. And
In the single-sided dissolution test, when extracted with a sufficient amount of water at room temperature for 5 hours, the mass of the unreacted residual ε-caprolactam and ω-laurolactam eluted in the water was 1 square of the sealant film layer, respectively. The packaging material for boil and retort treatment according to claim 1, wherein the packaging material is 0.15 mg or less and 0.04 mg or less per inch. The layer of nylon 6/12 has an unreacted residual ε-caprolactam content of 0.8% by mass or less, and an unreacted residual ω-laurolactam content of 0.1% by mass or less. And
In the single-sided dissolution test, when extracted at 100 ° C. for 8 hours in contact with a sufficient amount of water, the mass of nitrogen eluted in the water is 15 μg or less per square centimeter of the sealant film layer and 100 μg or less per square inch. The packaging material for boil and retort processing according to claim 1, wherein The transparent gas barrier film layer is a biaxially stretched multilayer film obtained by biaxially stretching a multilayer film having at least a polyester resin layer and a polyamide resin layer, and an inorganic oxide is deposited on one surface thereof. The packaging material for boil / retort treatment according to claim 1, wherein the packaging material is an inorganic oxide vapor-deposited film comprising a vapor-deposited layer. The polyester resin layer contains a crystalline polyester,
The boil / retort treatment according to any one of claims 1 to 5, wherein the polyamide-based resin layer contains 70 to 99% by mass of an aliphatic polyamide and 1 to 30% by mass of an aromatic polyamide. Packaging materials . The crystalline polyester is at least one selected from the group consisting of polyethylene terephthalate, isophthalic acid copolymerized polyethylene terephthalate, polybutylene terephthalate, and sulfoisophthalic acid copolymerized polyethylene terephthalate. Packaging material for boil and retort processing . The boil-retort treatment according to claim 6 or 7, wherein the aliphatic polyamide is at least one selected from the group consisting of nylon 6, and nylon copolymerized with nylon 6 and nylon 66. Packaging materials . The packaging material for boil / retort processing according to any one of claims 6 to 8, wherein the aromatic polyamide is polymetaxylene adipamide or amorphous nylon. The said vapor deposition layer is a layer formed by vapor-depositing at least 1 sort (s) of inorganic oxide selected from the group which consists of a silicon oxide, aluminum oxide, and magnesium oxide, The any one of Claims 5-9 characterized by the above-mentioned. The boil / retort packaging material according to item. When extracted with deionized distilled water at 135 ° C. for 1 hour, the mass of the eluate eluted into the water is 0.008 mg or less per square centimeter of the sealant film layer and 0.05 mg or less per square inch. The packaging material for boil / retort processing according to claim 1. When extracted with deionized distilled water at 121 ° C. for 2 hours, the mass of the chloroform-soluble component of the non-volatile extract eluted in the water is not more than 0.016 mg per square centimeter of the sealant film layer and 0.001 per square inch. It is 10 mg or less, The packaging material for boil retort processing of Claim 1 characterized by the above-mentioned.

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