JP2002052660A - Packing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packing material used at the time of filling of a bag with content, enabling the inspection of a metal after the heat sealing of an open port and capable of being completely burnt or regenerated after use. SOLUTION: The packing material comprises a laminate which has layered constitution wherein a gas barrier resin film layer (II) comprising an ethylene/ vinyl alcohol copolymer is laminated on a thermoplastic resin stretched film base layer (I) with opacity of 80% or more and a Clark degree (S-value) of 10 or more and a heat sealable resin adhesive layer (III) is laminated on the film layer (II). The moisture permeability (JIS-Z-0208) of this laminate is 10 g/m2.24 hr or more and the oxygen permeability (JIS-Z-1707) is 5 cc/m2.24 hr.atm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to tea, coffee beans,
The present invention relates to a packaging material suitable for packaging powders such as bath salts, medicines, agricultural chemicals, fertilizers, and candy, and liquids such as mirin, liquor, and juice.

[0002]

2. Description of the Related Art Usually, tea, coffee beans, bath additives, medicines,
Packaging of powders such as pesticides, fertilizers, candy (candy), etc., and liquids such as mirin, liquor and fruit juice requires prevention of transmission of water vapor and oxygen and transmission of visible light. Opaque packaging material consisting of a laminate in which a heat-sealable resin layer such as an ethylene-acrylic acid copolymer or ethylene-vinyl acetate copolymer is provided on the back side of aluminum foil on the back side of engineered printing paper, or biaxial An opaque packaging material consisting of a laminate of a stretched polyethylene terephthalate film / polyethylene film adhesive layer / aluminum foil / biaxially stretched polypropylene film / polyethylene heat sealable film is used by being molded into a carton box or a flexible packaging bag. I have.

[0003]

The above-mentioned powder packaging bag is
Since aluminum foil is used as a part of the constituent layer,
In general, after filling the contents of tea, coffee beans, and pharmaceuticals in a bag, inspecting the contents for foreign matter of metal powder, heat-sealing the opening of the bag, and shipping or storing. Was. However, the inspection during opening provides an opportunity for dust and foreign matter to enter the bag. Therefore, there is a need in the market for providing a packaging material capable of inspecting for metal powder contamination after heat-sealing the filling and opening openings. ing. Further, the conventional packaging material has a disadvantage that after burning, the aluminum foil remains as burning waste, and the treatment requires time and effort. The invention relates to filling,
An object of the present invention is to provide a packaging material that can be subjected to metal inspection after heat sealing of an open port and that can be completely burned or regenerated after use.

[0004]

Means for Solving the Problems That is, the first of the present application.
The invention of the eye has an opacity of 80% or more and
Stretched thermoplastic resin film whose degree (S value) is 10 or more
On the base layer (I), an ethylene-vinyl alcohol copolymer
Gas barrier resin film layer (II) consisting of
Heat-sealing resin adhesive layer (III)
A laminate having a layer configuration obtained by laminating
The material has a moisture permeability (JIS-Z-0208) of 10 g / m.^Two・
24 hours or less, oxygen permeability (JIS-Z-1707)
Is 5cc / m^Two・ It is not more than 24hr ・ atm
It is a packaging material. The second invention of the present application is an opaque
Brightness is 80% or more and Clark stiffness (S value) is 10
One of the above thermoplastic resin stretched film base layers (I)
Heat-sealable resin adhesive layer (III) on the surface of
On the other side from ethylene-vinyl alcohol copolymer
Gas barrier resin film layer (II)
A laminate having the following layer configuration, wherein the moisture permeability of the laminate is
(JIS-Z-0208) is 10 g / m.^Two・ 24 hours or less
Below, oxygen permeability (JIS-Z-1707) is 5cc
/ M ^Two・ It is characterized by being less than 24hr ・ atm
It is a packaging material. The third invention of the present application is a heat seal
Protective layer (IV) on the outermost layer on the side opposite to the conductive resin adhesive layer (III)
The package of the second invention of the present application characterized by having
Material.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the packaging material of the present invention will be described in detail. [I] Structure of wrapping material The structure of the wrapping material of the present invention comprises a stretched thermoplastic resin film base layer (I) / a gas barrier resin film layer made of an ethylene-vinyl alcohol copolymer (II) / heat-sealing resin adhesive. Laminated body composed of layer (III), gas barrier resin film layer composed of ethylene-vinyl alcohol copolymer (II) / stretched thermoplastic resin film base layer (I) /
Laminate composed of heat-sealable resin adhesive layer (III) or protective layer (IV) / gas barrier resin film layer composed of ethylene-vinyl alcohol copolymer (II) / stretched thermoplastic resin film base layer (I) / A laminate comprising a heat-sealable resin adhesive layer (III). These laminates have a moisture permeability (JIS-Z-0208) of 10 g / m ^2.
-24 hours or less, and oxygen permeability (JIS-Z-170
7) shows physical properties of 5 cc / m ² · 24 hr · atm or less. Printing P, which is performed as necessary, may be performed on the surface of the stretched thermoplastic resin film base layer (I) or on the gas barrier resin film surface.

[II] Layer Structure of Laminate (1) Base layer of stretched thermoplastic resin film (I) (a) Physical properties The stretched thermoplastic resin film (I) is applied to a wrapping material by making it stiff and opaque for printing. To make it easier to identify,
Opacity (JIS-P-8138) is 80% or more, preferably 8%.
5 to 100%, MD direction (longitudinal stretching direction),
Those having a Clark stiffness (JIS-P-8143: s value) in both the TD direction (direction perpendicular to the longitudinal stretching direction) of 10 or more, particularly preferably in the range of 10 to 300, are preferable. (b) Types Examples of the above-mentioned stretched thermoplastic resin film base layer (I) include the following.

[0007] The inorganic fine powder and / or organic filler are
It is a monoaxially or biaxially stretched film containing 65% by weight, and these stretched films may be a single layer or a multilayer. In the case of a multilayer film, the film may be produced by a co-extrusion molding method. For example, a film containing at least uniaxially stretched film containing 0 to 40% by weight of an inorganic fine powder and / or an organic filler may be a core layer (A). And the inorganic fine powder and / or
Alternatively, it may be a laminated stretched film provided as a front and back layer (B, C) with at least a uniaxially stretched film containing an organic filler in an amount of 0 to 65% by weight.

The physical properties of the thermoplastic resin stretched film base layer (I) These thermoplastic resin stretched film base layers (I) are:
It has fine voids inside the film and has an opacity (JIS-P-8138) of 80% or more, preferably 85% or more, and a porosity of 10 to 10 calculated by the following equation (1). 60%, preferably 15-45%, thickness 30
To 300 μm, preferably 50 to 200 μm, and more preferably 50 to 150 μm.

(Equation 2) Ρ _{0 in the} formula (1) represents the true density of the stretched film, and ρ ₁
Represents the density of the stretched film (JIS-P-8118). Unless the material before stretching contains a large amount of air, the true density is almost equal to the density before stretching.

Examples of the material for the stretched thermoplastic resin film layer (I) include ethylene resins such as high-density polyethylene and medium-density polyethylene, propylene resins, polymethyl-1-pentene, and ethylene-cycloolefin copolymers. Olefin resins such as nylon-6, nylon-6,6, nylon-6,10, nylon-6
12, thermoplastic resins such as polyethylene terephthalate and copolymers thereof, polyethylene naphthalate and aliphatic polyester, polycarbonate, atactic polystyrene, syndiotactic polystyrene, and polyphenylene sulfide. These may be used in combination of two or more. Among these, it is preferable to use a polyolefin resin. Furthermore, among olefin resins, propylene resins from the viewpoint of cost, water resistance, and chemical resistance,
Preferably, high density polyethylene is used.

The propylene resin is mainly composed of propylene homopolymer, polypropylene or propylene having isotactic or syndiotactic properties and various stereoregularities, and ethylene, butene-1, hexene- 1, copolymers with α-olefins such as heptene-1,4-methylpentene-1 are used. This copolymer may be a binary, ternary, or quaternary system, and may be a random copolymer or a block copolymer. Further, when a propylene-based resin is used for the core layer, polyethylene,
A thermoplastic resin having a melting point lower than that of a propylene-based resin such as polystyrene or ethylene-vinyl acetate copolymer is 3 to 25.
% By weight.

In the stretched thermoplastic resin film layer (I),
In addition to the above thermoplastic resin, inorganic fine powder and / or organic fine powder can be appropriately compounded. The type of the inorganic fine powder or the organic filler is not particularly limited. Examples of the inorganic fine powder include heavy calcium carbonate, light calcium carbonate, calcined clay, talc, barium sulfate, diatomaceous earth, magnesium oxide, zinc oxide, titanium oxide, and silicon oxide. Among them, heavy calcium carbonate, calcined clay, and talc are preferred because they are inexpensive and have good moldability.

As the organic filler, a melting point higher than the melting point of polyolefin resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon-6, nylon-6,6 and cyclic olefin polymer (for example, 120 to 300 ° C.) ) Or those having a glass transition temperature (for example, 120 ° C to 280 ° C) are used. These inorganic fine powders or organic fillers can be used alone or in combination. The stretching ratio is preferably 4 to 10 times in both the vertical and horizontal directions. The stretching temperature is 13 when the resin is a propylene homopolymer (melting point: 164 to 167 ° C).
0-162 ° C, high-density polyethylene (melting point 123-13)
4 ° C.), and 110 to 120 ° C. for polyethylene terephthalate (melting point: 246 to 252 ° C.).
20 ° C. The stretching speed is 10 to 350 m / min.

(2) Gas barrier resin film layer (II) The gas barrier resin film layer (II) imparts gas barrier properties, particularly oxygen gas barrier properties, to the packaging material. Used. As the gas barrier resin, the moisture permeability (JIS-Z-0208) is 300.
g / m ² · 24 hr or less, preferably 100 g / m ² ·
Ethylene having an oxygen permeability (JIS-Z-1707) of not more than 300 cc / m ² · 24 hr · atm, preferably not more than 200 cc / m ² · 24 hr · atm.
A vinyl alcohol copolymer is used. The ethylene-vinyl alcohol copolymer is not particularly limited as long as it is a solvent-soluble copolymer, but has an ethylene content of 20 to 60 mol%, preferably 25 to 55 mol%, and a saponification degree of 90% or more, preferably Is a copolymer of 95% or more. If the ethylene content is less than 20 mol%, the gas barrier property at high humidity decreases, while if it exceeds 60 mol%, sufficient gas barrier properties and film properties such as printability deteriorate. If the saponification degree is less than 90%, the gas barrier properties and the moisture resistance are reduced.

Lamination The lamination of the stretched thermoplastic resin film base layer (I) and the ethylene-vinyl alcohol copolymer is performed by coating.
Coating means is not particularly limited and conventionally used means, for example, comma coater, lip coater, dip coater, roll coater, gravure coater, air knife coater,
Reverse coater, kiss coater, T-die coater,
Meyer bar coaters, spray coaters, etc. can be used. The coating liquid containing the ethylene-vinyl alcohol copolymer is usually prepared using a mixed solvent of water and alcohol. If the adhesion of the coating layer (II) is insufficient depending on the type of the stretched thermoplastic resin film base layer (I), the distance between the thermoplastic resin stretched film base layer (I) and the coating layer (II) is as follows:
A primer (adhesive) (V) can be applied between the heat-sealable resin layer (III) and the coating layer (II).

Primer layer (V) Examples of the primer include polyester polyol / polyisocyanate and polyether polyol / polyisocyanate of a polyurethane primer. Primer coating amount is 0.5 ~
5 g / m ² (solid content) is common.・ Thickness The thickness of the gas barrier resin film layer (II) is 0.1 ~
15 μm, preferably 1 to 10 μm, more preferably 1 μm
５5 μm.

(3) Heat-Sealable Resin Adhesive Layer (III) The heat-sealable resin used as the heat-sealable resin adhesive layer (III) includes ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer, Low density polyethylene, metal salt of ethylene / (meth) acrylic acid copolymer (so-called Surlyn: trade name), chlorinated polyethylene,
A chlorinated polypropylene having a melting point of 60 to 135 ° C. is used. This heat-sealable resin adhesive layer (III)
Contributes to melting and bonding by heating when the packaging material is subjected to secondary processing into bags and carton boxes.

These layers may be formed by extrusion laminating the heat-sealing resin (I) on the back surface of the gas barrier resin film layer (II) or the stretched thermoplastic resin film (I). The heat-sealing resin (III) is formed on the back of the film layer (II) or the stretched thermoplastic resin film (I).
) May be formed by applying and drying a resin solution in which is dissolved or dispersed in an organic solvent such as toluene, xylene, or tetralin, or a heat-sealing resin film may be laminated.・ Thickness The thickness of the heat-sealable resin adhesive layer (III) is 1 to 50.
μm, preferably 2 to 40 μm.

(4) Protective layer (IV) In the case of contributing gloss to the surface of the packaging material, protecting the printing P on the surface of the packaging material, using the packaging material for a carton box, or the second invention of the present invention. When the gas barrier resin film layer (II) comes to the surface side as described above, it is preferable to provide a protective layer (IV) on these surfaces. As the protective layer, the same as the above heat-sealable resin, a non-stretched polypropylene film (CPP), a biaxially stretched polypropylene film (BOPP), a polyethylene terephthalate film, or the like can be used. -Thickness The thickness of the protective layer (IV) is 1 to 50 µm, preferably 2 to 50 µm.
40 μm.

(5) Other Layers The packaging materials are the above-mentioned thermoplastic resin stretched film base layer (I), a gas barrier resin film layer (II) made of an ethylene-vinyl alcohol copolymer, and a heat sealing resin adhesive layer (III). ) In addition to the protective layer (IV), woven fabric, non-woven fabric, light concealing layer, pulp paper, foamed resin layer, etc. are used to improve the rigidity, tear resistance and light opacity of the packaging material. It may be provided between the heat-sealable resin adhesive layer (III) and the stretched thermoplastic resin film base layer (I), or between the gas barrier resin film layer (II) and the stretched thermoplastic resin film base layer (I). . In order to use the packaging material in a carton box, the layers used to impart rigidity and foldability to the packaging material include carton paper having a thickness of 80 to 700 μm, white cardboard,
Extruded foamed resin sheets having an expansion ratio of 1.5 to 5 times, and thermoplastic resin films containing 25 to 55% by weight of inorganic fine powder (JP-A-5-245962, JP-A-6-91).
No. 795). The above-mentioned primer and heat-sealing resin are used for bonding these optional layers.

[II] Physical Properties of Packaging Material The packaging material of the present invention satisfies the following physical properties. Moisture permeability (JIS
-Z-0208) is 5 g / m ² · 24 hr or less. Oxygen permeability (JIS- Z-1707) is 10cc / m ² · ²
4 hr · atm or less. By satisfying such conditions, deterioration of the content and deterioration of the quality can be prevented.・ Clark stiffness MD direction (longitudinal stretching direction) and TD direction (direction perpendicular to the longitudinal stretching direction) of the thermoplastic resin stretched film base layer (I)
Clark stiffness is measured by a measuring instrument (Kumaya Riki Kogyo Co., Ltd.
Product name "OUTOMATIC CLARK STIFF
NESS TESTER ") and JIS-P-8
143. It is preferable that the Clark stiffness in both the MD direction and the TD direction be 10 or more, and particularly in the range of 10 to 300. If the Clark stiffness of the stretched thermoplastic resin film base layer (I) used in either the MD direction or the TD direction is less than 10, it is too soft, so that it is hard to use when used in a packaging bag.

Further, in order to package contents such as coffee beans, high-grade green tea, Maccha, fruit juice, shochu, etc., which dislike light rays, the total light transmittance of the packaging material (JIS-K-71).
05) must be 5% or less, preferably 0%. When the thickness of each layer is small and the opacity of light rays is insufficient, the concealment layer is formed by performing black printing of 1 to 5 μm in thickness on the back surface of the stretched thermoplastic resin film (I) by offset or gravure printing. A large amount of white filler such as titanium oxide whiskers, titanium oxide fine particles, etc., in the primer layer (V) to be formed or adhered to the thermoplastic resin stretched film base layer (I) and the heat-sealable resin film layer (III). (5 to 75% by weight), and the primer
To form a concealing layer by applying ｇ10 g / m ² ,
The total light transmittance of the packaging material is 5% or less, preferably 0%.

[III] Thickness of packaging material The thickness of the packaging material is 40 to 350 μm for use in a packaging bag.
m, preferably 80 to 200 μm, for flexibility, and for carton box applications, 350 to 1,000
It gives shape retention as μm.

[0023]

EXAMPLES The method of the present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Production of stretched thermoplastic resin film (Production Example 1) Melt flow rate (MFR: 230 ° C.,
2.16 kg load) A composition in which 81% by weight of polypropylene (melting point: about 164 to 167 ° C.) of 0.8 g / 10 minutes is mixed with 3% by weight of high-density polyethylene and 16% by weight of calcium carbonate having an average particle size of 1.5 μm. The product (A) was kneaded with an extruder set at a temperature of 270 ° C., extruded into a sheet, and further cooled by a cooling device to obtain a non-stretched sheet. After the sheet was heated again to a temperature of 150 ° C., it was stretched 5 times in the machine direction to obtain a 5 times machine-stretched film.

Melt flow rate (MFR) 4 g / 10
(B) obtained by mixing 54% by weight of polypropylene (melting point: about 164 to 167 ° C.) and 46% by weight of calcium carbonate having an average particle size of 1.5 μm in another extruder at 210 ° C.
, And extruded into a sheet by a die, and laminated on both sides of the 5-fold longitudinally stretched film obtained in the above step to obtain a laminated film having a three-layer structure. Then
After cooling the three-layer laminated film to a temperature of 60 ° C., it is again heated to a temperature of about 155 ° C., stretched 7.5 times in the transverse direction using a tenter, and annealed at a temperature of 165 ° C. Then, the mixture was cooled to a temperature of 60 ° C., the ears were slit, and the thickness of the three-layer structure (uniaxial stretching / biaxial stretching / uniaxial stretching) was 60 μm (B / A / B = 10 μm / 40 μm).
/ 10 μm), having an opacity of 87%, a porosity of 31%, a density of 0.79 g / cm ³ , and a Clark stiffness (S
Value) The thermoplastic resin stretched film base layer (I) in the MD direction 13 and the TD direction 24 was obtained.

(Production Example 2) Melt flow rate (MF
R: 230 ° C., 2.16 kg load) 0.8 g / 10 min of polypropylene (melting point: about 164 to 167 ° C.) 65% by weight, high-density polyethylene 10% by weight, and calcium carbonate 25 having an average particle size of 1.5 μm. % By weight, and a melt flow rate (MFR: 230 ° C.,
2. A composition (B) in which 99% by weight of polypropylene (melting point: about 164 to 167 ° C.) having a weight of 4 g / 10 min. And 1% by weight of rutile type titanium dioxide having an average particle diameter of 0.2 μm are mixed, and the melt flow rate is 2.16 kg. (MFR: 230
Polypropylene (melting point: about 164 to 167 ° C.) 100% by weight (C) having a melting point of 4 g / 10 min. (100 ° C., 2.16 kg load) was melt-kneaded at 250 ° C. using three separate extruders. Thereafter, the mixture was supplied to one co-pressing die, laminated in the die (B / A / C), extruded into a sheet, and cooled to about 60 ° C. with a cooling roll to obtain a laminated film.

After the laminated film is reheated to 145 ° C., it is stretched 5 times in the longitudinal direction by utilizing the peripheral speed difference of a large number of rolls, and is reheated to about 150 ° C. again, and is heated in the transverse direction by a tenter. Stretched 0.5 times. Then, after annealing at 160 ° C., it was cooled to 60 ° C.
Thickness 100 of layer structure (biaxial stretching / biaxial stretching / biaxial stretching)
μm (B / A / C = 3 μm / 94 μm / 3 μm) laminated film, opacity 90%, porosity 40%, density 0.
66 g / cm ³ , Clark stiffness (S value) MD direction 25,
A thermoplastic resin stretched film base layer (I) in TD direction 38 was obtained.

(Production Example 3) Melt flow rate (MF
R: 230 ° C., 2.16 kg load) 0.8 g / 10 min of polypropylene (melting point: about 164 to 167 ° C.) 60% by weight, low-density polyethylene 20% by weight (melting point: 111 ° C.)
And a composition (A) obtained by mixing 20% by weight of calcium carbonate having an average particle size of 1.5 μm, and a melt flow rate (MFR:
50% by weight of polypropylene (melting point: about 164 to 167 ° C.) having a weight of 230 g and a load of 2.16 kg) of 50% by weight, 45% by weight of calcium carbonate having an average particle size of 1.5 μm, and rutile dioxide having an average particle size of 0.2 μm. The composition (B) mixed with 5% by weight of titanium was melt-kneaded at 250 ° C. using three separate extruders. After that, it was supplied to one co-pressing die, laminated in the die, extruded into a sheet, and cooled to about 60 ° C. with a cooling roll to obtain a laminated film.

After the laminated film was reheated to 135 ° C., it was stretched 5 times in the machine direction by utilizing the peripheral speed difference of a number of roll groups, annealed at 150 ° C., cooled to 60 ° C. The part is slit and the thickness is 80 μm (B / A / B = 5 μm) in a three-layer structure (uniaxial stretching / uniaxial stretching / uniaxial stretching).
/ 70 μm / 5 μm) with an opacity of 90
%, A porosity of 40%, a density of 0.80 g / cm ³ , a Clark stiffness (S value) of 33 in the MD direction and 18 in the TD direction to obtain a stretched thermoplastic resin film base layer (I).

(Production Example 4) 3% by weight of calcium carbonate having a particle size of 0.8 μm, and a melt flow rate (MFR: 230)
Resin composition (D) containing 97% by weight of a propylene / ethylene block copolymer having a propylene / ethylene block copolymer of 1.2 g / 10 min.
5% by weight, melt flow rate (MFR: 230 ° C.,
2.16 kg load) is 1.2 g / 10 min of propylene
Ethylene block copolymer 28% by weight, melt flow rate (MFR: 230 ° C., 2.16 kg load) 4 g /
The resin composition (E) composed of 42% by weight of a propylene homopolymer for 10 minutes and 5% by weight of a low-density polyethylene was melt-kneaded at 260 ° C. using separate extruders, and then supplied to one die. Laminated in the die (D / E / D = 12
μm / 300 μm / 12 μm) on one side,
The three-layer stretched film obtained in the above was extrusion-laminated and compression-cooled with a roll to obtain a laminated sheet having a thickness of 404 μm (D / E / D / film of Production Example 1).

[0030]

Example 1 An ethylene-vinyl alcohol copolymer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., Soarnol 16D) was added to 90 parts by weight of a mixed solvent of water and isopanol (mixing weight ratio: 1: 1).
X (trade name), ethylene content: 29%) was added and dissolved by heating to prepare a coating solution. The above-mentioned coating liquid was applied to the stretched thermoplastic resin film having a thickness of 60 μm obtained in Production Example 1 using a comma coater, and the coating amount after drying was 4.0 g /.
Coating was performed under the conditions of m ² and dried to form a coating layer.

Then, a polyurethane primer "BLS-280A" and "BLS-2080B" of Toyo Morton Co., Ltd. were applied to the coated surface of the ethylene-vinyl alcohol copolymer.
Mixture 85 parts by weight, the adhesive obtained by mixing titanium oxide 15 parts by weight of 8 g / m ² (solid content) coating, the thickness 40μm of
Low-density polyethylene film of thickness 110μ
m (printing / stretched thermoplastic resin film / ethylene-vinyl alcohol copolymer / low density polyethylene film), opacity 100%, total light transmittance 0%, moisture permeability 3.6 g / m ² · 24 hr, Oxygen permeability is 2.4c
A packaging material of c / m ² · 24 hr · atm was obtained.

Then, after gravure printing was performed on the surface of the stretched thermoplastic resin film, two sheets of this packaging material were stacked such that the low-density polyethylene films faced each other, and one of the three sides was 5 mm wide.
Heat impulse seal at 90 ° C for 30 seconds and length 95m
A packaging bag for tea tea bags having a width of 80 mm and a width of 80 mm was prepared, and it was confirmed that metal powder was not mixed in from outside the bag with a metal detector.

Freshness Measurement A tea tea bag was placed in the bag, the opening was heat-sealed, and the bag was allowed to stand in a cool and dark place for 3 months, and evaluated according to the following criteria. ：: The bag was opened and the tea was checked for discoloration and flavor.
All were comparable to those of the tea before packaging. ×: The bag was opened, and the presence or absence of discoloration and the flavor of the black tea were examined.
Discoloration and change in flavor were observed compared to those of the black tea before packaging. Table 1 shows the results.

[0034]

Example 2 An ethylene-vinyl alcohol copolymer was applied to the stretched thermoplastic resin film having a thickness of 100 μm obtained in Production Example 2 in the same procedure as in Example 1 to form a coating layer. Then, a polyurethane primer “BLS-” of Toyo Morton Co., Ltd. was applied to the surface of the stretched thermoplastic resin film.
An adhesive obtained by mixing 15 parts by weight of titanium oxide with 85 parts by weight of a mixture of “280A” and “BLS-2080B” is 8 g /
m ² (solid portion), a 30 μm-thick unstretched polypropylene (CPP) film was adhered as a heat-seal resin adhesive layer, and gravure printing was performed on the surface of the ethylene-vinyl alcohol copolymer coated surface. On the printing surface, Toyo Morton Co., Ltd. polyurethane primer "BLS-28"
0A "and" BLS-2080B "mixture 1g / m
² (solid portion) Coating and bonding a non-stretched polypropylene (CPP) film with a thickness of 20 μm as a protective layer to a thickness of 160 μm (CPP / printing / ethylene-vinyl alcohol copolymer / stretched thermoplastic resin film) / CPP), opacity is 100%, total light transmittance is 0%, and moisture permeability is 3.
2 g / m ² · 24 hr, oxygen permeability 2.2 cc / m ²
A packaging material of 24 hr · atm was obtained. Next, in the same manner as in Example 1, the tea tea bag was packaged and freshness was measured. Table 1 shows the results.

[0035]

Example 3 An ethylene-vinyl alcohol copolymer was applied on the stretched thermoplastic resin film having a thickness of 80 μm obtained in Production Example 3 in the same procedure as in Example 1 to form a coating layer. . Next, polyurethane primers “BLS-280A” and “BLS-2080” of Toyo Morton Co., Ltd. were applied to the ethylene-vinyl alcohol copolymer coated surface of the base material.
A mixture of 85 parts by weight of the mixture of "B" and 15 parts by weight of titanium oxide was coated with 8 g / m ² (solid portion) of an adhesive,
A non-stretched polypropylene (CPP) film having a thickness of 30 μm is adhered, and then a gravure printing is performed on the surface of the stretched thermoplastic resin film, and a thickness of 120 μm (printing / stretched thermoplastic resin film / ethylene-vinyl alcohol copolymer / CPP), opacity was 100%, total light transmittance was 0%, moisture permeability was 3.5 g / m ² · 24 hr, and oxygen permeability was 2.6 cc / m ² · 24 hr · atm. Next, in the same manner as in Example 1, the tea tea bag was packaged and freshness was measured. Table 1 shows the results.

[0036]

Example 4 A two-pack reaction type anchor coating agent (AD-335A / CAT10L (trade name), Toyo Morton Co., Ltd.) was added to the stretched thermoplastic resin film having a thickness of 60 μm obtained in Production Example 1 for 0 hours. After coating and drying at a rate of 0.5 g / m ^{2, a} coating amount of the ethylene-vinyl alcohol copolymer coating liquid after drying was 4.0 g / m ² using a comma coater in the same procedure as in Example 1. Coating was performed under the conditions of ² to form a coating layer. Then, gravure printing is performed on the surface of the stretched thermoplastic resin film, and then a polyurethane primer “B” of Toyo Morton Co., Ltd.
A mixture of “LS-280A” and “BLS-2080B” was applied at 0.5 g / m ² (solid content), and a 25 μm polyethylene terephthalate film was laminated.

Then, a mixture of polyurethane primers “BLS-280A” and “BLS-2080B” of Toyo Morton Co., Ltd. at 2.0 g / m ² (solid content) was coated on the ethylene-vinyl alcohol copolymer coated surface. Then, the laminated sheet having a thickness of 404 μm obtained in Production Example 4 was laminated on the D surface side. Further, on the opposite side of the obtained laminated sheet to the polyethylene terephthalate film, polyurethane primers “BLS-280A” and “BLS-2” of Toyo Morton Co., Ltd.
080B ”, 90 g of the mixture, 10 g of titanium oxide mixed with 4.0 g / m ² (solid portion) was applied, and a low-density polyethylene film having a thickness of 40 μm was laminated, and the thickness was 540 μm. A packaging material for a carton box having a structure of polyethylene terephthalate film / printing / stretched thermoplastic resin film / ethylene-vinyl alcohol copolymer / laminated sheet of Production Example 4 / low-density polyethylene was obtained. Opacity is 100%, total light transmittance is 0%, moisture permeability is 2.0 g / m ² · 24 hr, oxygen permeability is 2.0c
c / m ² · 24 hr · atm.

After cutting this packaging material and then assembling it into a box, the bonded portion is heat-sealed to form a 1-liter carton box, and a metal detector is used to check that metal powder is not mixed in from outside the box. After confirmation, sake was put in this box, and the opening was heat-sealed. After heat sealing the opening, it was left in a cool and dark place for 3 months. Three months later, the bottle was opened and the taste of the sake was confirmed, but there was no difference in taste between the sake of the same brand and stored in a glass bottle.

[0039]

Comparative Example 1 The procedure of Example 1 was repeated, except that a gas barrier resin film layer made of an ethylene-vinyl alcohol copolymer was not laminated.
A μm packing material was obtained. Next, a bag was formed in the same manner as in Example 1, and freshness was measured. Table 1 shows the results.

[0040]

[Table 1]

[0041]

The packaging material according to the present invention is a packaging material having excellent light blocking properties and gas barrier properties. A packaging container such as a bag or a carton box formed by using this packaging material has a metal content. Inspection for the presence of powder contamination can be performed from outside the container with a metal detector.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a packaging material according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a packaging material according to a second embodiment of the present invention.

[Explanation of symbols]

 I Stretched thermoplastic resin film II Gas barrier resin film layer III Heat sealable resin adhesive layer IV Protective layer V Primer P Printing

Continued on the front page F-term (reference) 3E086 BA04 BA15 BA24 BA33 BA35 BA43 BB02 BB05 BB22 BB51 CA07 CA11 CA15 CA28 CA29 4F006 AA12 AA51 AB20 AB74 BA05 CA07 4F100 AA01A AH00A AK01A AK01C AK04B AK06 BA10BAKA CA23A CB00G CB03C CC00 DE01A DJ00A EH46B EJ37A EJ65G EJ91 GB15 GB17 GB23 HB31 JB16A JD02 JD02B JD03 JD04 JK01A JL12C JL16 JN02A YY00 YY00A YY00B

Claims (8)

[Claims] 1. A gas barrier resin comprising an ethylene-vinyl alcohol copolymer on a thermoplastic resin stretched film base layer (I) having an opacity of 80% or more and a Clark stiffness (S value) of 10 or more. A film layer (II) is laminated, and a heat-sealable resin adhesive layer (III) is further formed thereon.
Having a layered structure obtained by laminating a laminate having a moisture permeability (JIS-Z-0208) of 10 g / m ² ···
24 hours or less, oxygen permeability (JIS-Z-1707)
Is 5 cc / m ² · 24 hr · atm or less. 2. A heat-sealable resin adhesive layer (III) is laminated on one surface of a thermoplastic resin stretched film base layer (I) having an opacity of 80% or more and a Clark stiffness (S value) of 10 or more. A laminate having a gas barrier resin film layer (II) made of an ethylene-vinyl alcohol copolymer on the other surface, wherein the laminate has a moisture permeability (JIS-Z −0208) is 10.
g / m ² · 24 hr or less, oxygen permeability (JIS-Z-
1707) is 5 cc / m ² · 24 hr · atm or less. 3. The heat-sealable resin adhesive layer (III)
The packaging material according to claim 2, wherein a protective layer (IV) is provided on the outermost layer on the opposite side of the packaging material. 4. The gas barrier resin film layer (I)
The packaging material according to any one of claims 1 to 3, wherein I) is a layer formed by a coating method. 5. The packaging material according to claim 1, wherein the ethylene-vinyl alcohol copolymer has an ethylene content of 20 to 60 mol%. 6. The thermoplastic resin stretched film base layer (I) may contain an inorganic fine powder and / or an organic filler in an amount of from 0 to 4%.
A stretched film stretched in at least uniaxial direction containing 0% by weight is used as a core layer (A), and on both sides of this core layer is stretched in at least uniaxial direction containing 0 to 65% by weight of an inorganic fine powder and / or an organic filler. The packaging material according to any one of claims 1 to 5, wherein the packaging material is a laminated stretched film provided with the stretched film as a front and back layer (B, C). 7. The packaging material according to claim 6, wherein the porosity of the stretched thermoplastic resin film base layer (I) represented by the following formula (1) is 10 to 60%. (Equation 1) 8. The packaging material according to claim 1, wherein the thermoplastic resin stretched film base layer (I) is a polypropylene-based stretched film.