JP6213057B2 - Laminated body and packaging material and packaging bag using the same - Google Patents

Description

  The present invention relates to a laminate having heat insulation properties using a heat-shrinkable film, a packaging material using the laminate, and a packaging bag.

  In the case of canned coffee or paper cups for hot beverages, it may be hot and hesitating to hold with bare hands. In addition, in the case of foods such as retort foods that are heated up to 100 ° C., there is even a risk of burns.

  On the other hand, in the case of frozen food, there is an opportunity to be exposed to room temperature at each stage of distribution, sales, and storage in the refrigerator, and condensation tends to occur each time.

  If heat insulation can be given to the packaging material and the packaging bag, these problems can be solved, but adding one layer of expensive heat insulation material directly affects the cost increase of the packaging material, It was difficult to put it into practical use.

  Several techniques are known that make use of the property that a heat-shrinkable film shrinks when heated to make the laminate exhibit heat insulation. In the heat insulation expression container described in Patent Document 1, substrates having different heat shrinkage rates are bonded to each other at a bonding point with a space therebetween to form a laminated body, and the laminated body is heated between the bonding points. This is a container that is fixed or attached to the outer wall surface of a thin-walled container, with the one having the larger shrinkage rate inside.

  The heat insulation expression container described in Patent Document 1 exhibits heat insulation by, for example, sticking two of the laminates to the position held by the hand of the body of a paper cup, and the laminates swell with the heat of the contents. Therefore, it is said that a paper cup that does not heat even when held by hand can be realized.

  However, since the heat-insulating expression container described in Patent Document 1 has a heat-shrinkable base material disposed on the surface in contact with the outer wall surface of the container, the bent heat-shrinkable base material cannot sufficiently shrink. Contain contradiction.

In the heat-shielding packaging film described in Patent Document 2, a non-heat-shrinkable film having a thickness of 6 to 50 μm is formed on at least one surface of a heat-shrinkable film having a thickness of 20 to 100 μm via an adhesive layer. A film for packaging, wherein the adhesive layer is partially formed instead of the entire surface, and satisfies the following conditions.
a) When the heat-shielding packaging film is heat-shrinked, an air-insulating layer is formed on the portion where the heat-shrinkable film and the non-heat-shrinkable film are not formed with an adhesive layer. b) Surface temperature of the heat-shielding packaging film when the heat-shielding packaging film is covered with a container having a surface temperature of 60 ° C. and then thermally contracted by 10% and the container is covered with the heat-shielding packaging film. Is lower than the surface temperature of the container by 1 ° C. or more.

  The heat-shielding packaging film described in Patent Document 2 may be either a heat-shrinkable film on the outside or on the inside, and is not used by being fixed to other containers, but is used by mounting. The problems in the adiabatic container described in Document 1 have been overcome.

Japanese Patent Laid-Open No. 7-40961 JP 2004-9670 A

  The heat-shielding packaging film described in Patent Document 2 is obtained by partially adhering a heat-shrinkable film and a non-heat-shrinkable film, and is used after being covered with another container before use. To do. Therefore, a packaging container cannot be formed with the heat-shielding packaging film itself.

  The problem to be solved by the present invention is to propose a laminated body having heat insulating properties that can be easily formed into a cylindrical shape or a bag shape, and a packaging material and a packaging bag using the laminated body.

As a means for solving the above problems, the invention according to claim 1 is a laminate having two or more plastic film layers,
Having a heat-shrinkable base material layer in the first layer which is the outermost layer;
The innermost layer has a heat-melting resin layer having heat sealing properties ,
The first layer and the second layer adjacent to the first layer are laminated by a heat-resistant adhesive layer,
The heat-resistant adhesive layer is formed in a pattern and has a pattern laminate region having a chipped portion of 10% or more, and the heat-resistant adhesive layer has a heat-welded region having no chipped portion, In the glue part, the first layer and the second layer are not bonded,
Having the heat-welded region at the front end and the rear end with respect to the heat shrink direction,
It is the laminated body characterized by this.

  Since the laminated body according to the present invention has a heat-melting resin layer in the innermost layer and a heat-welded region, it can be freely molded into a cylindrical shape or a bag shape like a general packaging material film. it can. Further, when the laminate is heated, the outermost heat-shrinkable base material layer shrinks in the pattern region, so that an air layer is generated due to the generated wrinkles and exhibits heat insulation.

  In the invention according to claim 2, the dimensional shrinkage ratio in at least one direction of the flow direction or the width direction when the heat-shrinkable base material layer is immersed in warm water of 80 ° C. for 10 seconds is 10% or more. The laminate according to claim 1, which is a heat-shrinkable polyethylene terephthalate film.

  The invention according to claim 3 is the laminate according to claim 1 or 2, wherein the laminate includes a gas barrier layer.

The invention according to claim 4, that the laminate according to 請 Motomeko 1 or 2, wherein the hot melt resin layer has formed the both end portions so that inward and heat welded tubular It is a characteristic packaging material.

  Moreover, invention of Claim 5 makes the laminated body of any one of Claims 1-3 which have the said heat welding area | region in a peripheral part so as to oppose so that the said hot melt resin layer may become an inner side. The packaging bag is characterized in that the peripheral edge is thermally welded and formed into a bag shape.

  The laminate according to the present invention has a heat-melting resin layer as the innermost layer, and a first layer composed of a heat-shrinkable base material layer and a second layer adjacent thereto are laminated by a heat-resistant adhesive layer. The heat resistant adhesive layer is formed in a pattern and is divided into a pattern laminate region having a chipped portion of 10% or more, and a heat welded region in which the heat resistant adhesive layer does not have a chipped portion. Therefore, using this heat-welded area, it is possible to perform bag-making processing and other processes with heat-welding as well as general packaging material films. It can be applied.

  In addition, the laminate according to the present invention exhibits heat insulation because the heat-shrinkable base material layer shrinks when the pattern laminate region is heated, thereby causing wrinkles in the laminate and an air layer. . For this reason, for example, it is possible to realize a packaging bag in which food heated in a microwave oven can be handled by hand, or a frozen food packaging bag to which frost hardly adheres during distribution and sale.

  As in the invention described in claim 2, the dimensional shrinkage ratio in at least one direction of the flow direction or the width direction is 10% or more when immersed in hot water at 80 ° C. for 10 seconds as the heat-shrinkable base material layer. In the case where a heat-shrinkable polyethylene terephthalate film is used, the material can be easily obtained, the heat-shrinkage characteristics are excellent, and a laminate that can be used for various purposes can be obtained.

  When the laminate includes a gas barrier layer as in the invention described in claim 3, it can also be used for applications premised on long-term storage. In addition, for example, when used in a retort food packaging bag, the heat-shrinkable base material layer can be shrunk at a high temperature during retort sterilization, so that it is not necessary to provide a heat shrinking process again.

  As in the invention according to claim 4, both ends are thermally welded so that the heat-welded resin layer is inside the laminated body having the heat-welded regions at the front end and the rear end with respect to the heat shrink direction. The packaging material formed into a cylindrical shape is suitably used for applications such as an outer cylinder of canned coffee that is hot and cannot be held by hand.

  As in the invention according to claim 5, a packaging bag in which a laminate having a heat-welded region at a peripheral portion is opposed so that a heat-welded resin layer faces inside, and the peripheral portion is heat-welded and formed into a bag shape. Can be used for various applications as a packaging bag having heat insulation properties. In particular, when a laminate including a gas barrier layer is used, for example, when used for a retort food, it can be safely used without fear of being burned when heated and eaten.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a laminate according to the present invention. FIG. 2 is an explanatory cross-sectional view showing a state in which the laminated body of FIG. 1 is heated. FIG. 3 is a schematic cross-sectional view showing another embodiment of the laminate according to the present invention. FIG. 4 is a schematic cross-sectional view showing another embodiment of the laminate according to the present invention. FIG. 5 is a schematic plan view showing one embodiment of the laminate according to the present invention. FIG. 6 is a schematic cross-sectional view showing an example of a packaging material obtained by processing the laminate shown in FIG. 5 into a cylindrical shape. FIG. 7 is a perspective view showing an example of a packaging bag obtained by processing the laminated body according to the present invention into a bag shape. FIG. 8 is a schematic plan view showing an example of the application pattern of the heat-resistant adhesive in the pattern laminate region of the laminate according to the present invention. FIG. 9 is a schematic plan view showing another example of the application pattern of the heat-resistant adhesive in the pattern laminate region. FIG. 10 is a schematic plan view showing another example of the application pattern of the heat-resistant adhesive in the pattern laminate region. FIG. 11 is a schematic plan view showing another example of the application pattern of the heat-resistant adhesive in the pattern laminate region.

Hereinafter, the laminate according to the present invention, a packaging material using the same, and a packaging bag will be described in detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an embodiment of a laminate according to the present invention. FIG. 2 is an explanatory cross-sectional view showing a state in which the laminate of FIG. 1 is heated.

  The laminate (1) according to the present invention is a laminate having two or more plastic film layers, and has a heat-shrinkable substrate layer (2) in the first layer which is the outermost layer, and in the innermost layer. It has a hot-melt resin layer (6). In the laminate (1) according to the present invention, the first layer and the second layer adjacent thereto are laminated by the heat-resistant adhesive layer (3), and the heat-resistant adhesive layer (3) is patterned. And a pattern laminate region (7) having a chipped portion (9) of 10% or more, and a heat-welded region (8) in which the heat-resistant adhesive layer (3) does not have a chipped portion. It is characterized by.

  In the embodiment shown in FIG. 1, the second layer is the heat-melting resin layer (6), and the heat-shrinkable base material layer (2) and the heat-melting resin layer (6), which are the first layers, are heat resistant. Laminated with an adhesive layer (3). In this example, both ends of the laminate (1) are heat-welded regions (8) that do not have a chipped portion (9), and the pattern laminated region (7) that has a chipped portion (9) at the center. It has become.

  FIG. 2 is an explanatory cross-sectional view showing a state in which the laminate (1) in FIG. 1 is heated. When the laminate (1) according to the present invention is heated, the heat-shrinkable base layer (2) shrinks, but the other layers do not shrink as much as the heat-shrinkable base layer (2). Therefore, the laminate (1) generates wrinkles (10) due to shrinkage, and air enters the chipped portion (9) to create an air layer (11). By this air layer (11) and wrinkle (10), the heat insulation effect as the whole laminated body is produced.

  3 and 4 are schematic cross-sectional views showing other embodiments of the laminate (1) according to the present invention. In the embodiment shown in FIG. 3, an intermediate layer (4) exists between the heat-shrinkable base material layer (2) that is the outermost layer and the hot-melt resin layer (6) that is the innermost layer. It has two layers. A heat-shrinkable base material layer (2) and an intermediate layer (4) are laminated by a heat-resistant adhesive layer (3), and the heat-resistant adhesive layer (3) has a chipped portion (9). Region (7) is formed. The intermediate layer (4) and the hot melt resin layer (6) are laminated by the adhesive layer (5).

  In the embodiment shown in FIG. 4, a gas barrier layer (12) is further formed on the hot melt resin layer (6) side of the intermediate layer (4). In this example, the gas barrier layer (12) is directly provided on the back side of the intermediate layer (4), but may be an independent layer.

Next, the material of each layer which comprises a laminated body (1) is demonstrated.
As the heat-shrinkable substrate layer (2), a shrink film generally used for shrink wrapping or the like can be used. As the material, vinyl chloride resin, polystyrene resin, polyethylene terephthalate (PET) resin, etc. are common. Among these, a PET film (S-PET) having a shrinkage in the flow direction or width direction of 10% or more when immersed in a warm water bath at 80 ° C. for 10 seconds is most suitable for the laminate of the present invention. Yes.

Various films for packaging materials can be used as the intermediate layer (4). For example, a stretched polypropylene film (OPP), a stretched PET film (PET), a stretched nylon film (ONY, NY), and the like.

  As the hot melt resin layer (6), various materials used as a sealant layer for packaging materials can be used. Examples include low density polyethylene resin (LDPE), medium density polyethylene resin (MDPE), linear low density polyethylene resin (LLDPE), ethylene-vinyl acetate copolymer, ethylene-α olefin copolymer, ethylene-meta. Ethylene resins such as acrylic resin copolymers, blend resins of polyethylene and polybutene, homopolypropylene resins, propylene-ethylene random copolymers, propylene-ethylene block copolymers, propylene-α olefin copolymers, etc. Polypropylene resin or the like is used.

  As the gas barrier layer (12), various gas barrier films are used in addition to a gas barrier film obtained by depositing aluminum, aluminum oxide, silicon oxide or the like on the surface of the film used as the intermediate layer (4) or the hot-melt resin layer (6). be able to. Examples of the gas barrier film include a gas barrier film such as a polyvinylidene chloride film, a polyvinyl alcohol film, an ethylene vinyl alcohol copolymer film, a gas barrier nylon film, and a gas barrier polyethylene terephthalate (PET) film. A metal foil such as an aluminum foil can also be used.

  As the heat resistant adhesive layer (3), a known thermosetting adhesive can be used. Specifically, a polyisocyanate curable polyurethane resin adhesive, an ultraviolet curable acrylic urethane resin adhesive, and the like.

  FIG. 5 is a schematic plan view showing an embodiment of the laminate (1) according to the present invention. FIG. 6 is a schematic cross-sectional view showing an example of a packaging material (13) obtained by processing the laminate (1) shown in FIG. 5 into a cylindrical shape.

  In the example shown in FIG. 5, in the laminate (1) having a height of 100 mm and a width of 250 mm, a pattern laminate region (7) in which a heat-resistant adhesive layer is formed in a dot shape is provided at the center, A thermal welding region (8) having a width of 10 mm without a chipped portion is provided at the front end and the rear end with respect to both ends, that is, the heat shrink direction (16).

  The laminate (1) is rolled into a cylindrical shape so that the hot-melt resin layer (6) is on the inside, and the heat-welded regions (8) at both ends are overlapped so that the hot-melt resin layers (6) face each other. When heat sealing is performed together, and the sealing portion is folded back and adhered to the outer surface, a cylindrical packaging material (13) as shown in FIG. 6 is completed.

  When this packaging material (13) is placed on a bottle (15) having a height of 105 mm and a diameter of 64 mm and heated with hot air, the surface becomes a fine wrinkle and the whole shrinks to adhere to the bottle surface. Since the packaging material (13) exhibits heat insulation by the action of the wrinkles and the air layer, it can be easily held by hand even when a hot beverage is stored in the bottle.

  FIG. 7 is a perspective view showing an example of a packaging bag (14) obtained by processing the laminate (1) according to the present invention into a bag shape. In this example, two laminated bodies are opposed to each other so that the hot-melt resin layer is on the inner side, and the peripheral edge portion is thermally welded to form a bag shape. Since the heat-resistant adhesive layer (3) is provided with a heat-welded region (8) that does not include a chipped portion at the peripheral edge, it can be easily heat-sealed. Further, the heat seal strength can be sufficiently exhibited.

On the other hand, the entire surface of the central portion of the packaging bag (14) is a pattern laminate region (7), and a wrinkle (10) and an air layer (11) based thereon are formed on the entire surface. Demonstrated. When this packaging bag (14) is used as a packaging bag for retort foods, it can be touched by hand even at a high temperature immediately after heating, and when it is used as a packaging bag for frozen foods, it is used as a packaging bag that is hard to condense. be able to.

  8 to 11 show examples of application patterns of the heat-resistant adhesive layer (3) in the pattern laminate region (7). In the example of FIG. 8, the heat-resistant adhesive layers (3) applied in a dot shape having a diameter of 1.5 mm are arranged at a pitch of 3 mm. Therefore, the adhesive area ratio of the adhesive is about 20%.

  In the example of FIG. 9, the heat-resistant adhesive layer (3) is applied in a crepe pattern, and the adhesive area ratio is about 60%.

  In the example of FIG. 10, the heat-resistant adhesive layer (3) is applied in a stripe shape having a width of 5 mm, and the adhesive area ratio is 50%.

In the example of FIG. 11, the heat-resistant adhesive layers (3) applied in a dot shape having a diameter of 0.3 mm are arranged at a pitch of 0.5 mm. Therefore, the adhesive area ratio of the adhesive is about 30%.
Hereinafter, based on an Example, the laminated body which concerns on this invention, a packaging material using the same, and a packaging bag are demonstrated further more concretely.

A cup sleeve was studied. The layer configuration was heat-shrinkable base material layer / printing layer / heat-resistant adhesive layer (pattern coat) / heat-melting resin layer.
First, after printing on the back surface of the heat-shrinkable base material layer, a dry laminating adhesive (A626 made by Mitsui Takeda Chemical Co., Ltd.) is applied to the printed surface in a pattern, and a hot-melt resin layer (sealant film) and The laminated body was obtained by bonding.

  The end of the laminate was heat-sealed with the heat-melting resin layer surface inside, and the ends were heat-sealed and formed into a cylindrical shape to obtain a sleeve-shaped packaging material. This packaging material was placed on a cup container, and was closely adhered to the cup container through a tunnel for shrink heating, and at the same time wrinkles were generated on the surface.

<Evaluation of packaging materials>
About this cup container, shrink suitability and heat insulation were evaluated. Shrinkability was evaluated as “◯” when the sleeve was in close contact with the cup during shrinking, and “X” when non-uniform floating or dropping occurred without contact. In addition, the heat insulation property was rated as “◯” when pouring hot water of 90 ° C. into the cup, and the sleeve surface temperature was below the temperature (60 ° C.) that can be held by hand, and “x” when exceeding 60 ° C.

By changing the material of the heat-shrinkable base material layer, the brand, the material of the hot melt resin layer, the brand, and the coating pattern of the heat-resistant adhesive layer, each laminate of Examples 1 to 5 and Comparative Examples 1 and 2 was changed. A sleeve was similarly prepared and evaluated. These are shown in Table 1.
The abbreviations and brand names in the table are as follows.
Heat-shrinkable substrate layer:
TAS: Heat shrinkable PET film (S-PET) manufactured by Gunze
TNB: Heat shrinkable PET film manufactured by Gunze RX40S: Heat shrinkable PET film manufactured by Mitsubishi Plastics S2600: Heat shrinkable PET film manufactured by Toyobo GMPS: Heat shrinkable PS film (S-PS) manufactured by Gunze
E5100: PET film (non-heat-shrinkable) manufactured by Toyobo Co., Ltd.
Hot melt resin layer (sealant film):
MCS: LLDPE TUX (trade name) MC-S manufactured by Mitsui Chemicals, Inc.
L Smart: LLDPE L Smart (trade name) manufactured by Mitsui Chemicals, Inc.
UB106: LLDPE UB106 manufactured by Tamapoli
ES1: Heat seal OPP (HSOPP) ES1 manufactured by Gunze
FHK2: CPP FHK2 manufactured by Futamura Chemical Co., Ltd.

  In Examples 1 to 5, as a result of shrinkage of the chipped portion of the heat-shrinkable base material layer, the heat-melt resin layer is uneven, and the whole shrinks with an air layer formed between the inserted cup surface. Therefore, the shrink suitability was good. In addition, the heat insulating properties were different depending on the kind of film, the thickness, the adhesive pattern, etc., but the handling suitability was good.

  On the other hand, in Comparative Examples 1 and 2, it did not shrink even after passing through the shrink tunnel, and could not be attached to the cup container.

Next, the packaging bag was examined. The layer configuration was heat-shrinkable base material layer / printing layer / heat-resistant adhesive layer (pattern coat) / intermediate layer / adhesive layer (solid) / hot-melt resin layer.
First, after printing was performed on the back surface of the heat-shrinkable base material layer, an adhesive for dry lamination (A626 made by Mitsui Takeda Chemical Co., Ltd.) was applied to the printed surface in a pattern and bonded to the intermediate layer film. Next, the same adhesive for dry lamination as described above was applied to the entire film surface of the intermediate layer and bonded to the hot melt resin layer (sealant film) to obtain a laminate.

  The laminate was aged at room temperature to completely cure the adhesive, and then the sealant surfaces were opposed to each other and the three sides were heat-sealed to form a bag. The packaged bag is filled with cooked meatballs together with a cooking sauce, and the opening is sealed by heat sealing under conditions of 150 ° C., 0.2 MPa, 1 second, and then immersed in a boil tank at 90 ° C. for 30 minutes. Was sterilized.

<Evaluation of packaging bags>
The packaging bag was evaluated for anti-frost effect and heat insulation. When the above package is frozen and stored at -18 ° C and then displayed in a store display freezer (-5 ° C) for 1 week, it is evaluated as x when frost is attached to the front of the package, and ○ when it is not attached. did.

  As an evaluation of heat insulation, the package is immersed in boiling hot water, cooked for 10 minutes, and then taken out. If the temperature of the package surface can be held by hand (60 ° C. or less), ○, over 60 ° C. The case was evaluated as x.

Samples of Examples 6 to 10 and Comparative Examples 3 and 4 were prepared by changing the material, thickness, brand, and the like of each layer. The results are shown in Table 2. The abbreviations and brand names in the table are as follows. However, those common to Table 1 are omitted.
Intermediate layer, gas barrier layer:
M251: Unitika's gas barrier nylon multilayer film Embron
(Product Name) M251
GL-ARH: Gas barrier alumina-deposited PET film manufactured by Toppan Printing Co., Ltd.
GL-ARH (trade name)
GL-AEY: Gas barrier alumina-deposited nylon film manufactured by Toppan Printing Co., Ltd.
GL-AEY (trade name)
ONBC: Unitika Nylon film emblem (trade name) ONBC
Hot melt resin layer (sealant film):
LIX-NP: LLDPE RIX (trade name) film NP manufactured by Toyobo Co., Ltd.
TUX-HZ: LLDPE T. manufactured by Mitsui Chemicals, Inc. U. X (trade name)-HZ

  In Examples 6 to 9, as a result of shrinkage of the chipped portion of the heat-shrinkable base material layer, the intermediate layer / heat-melting resin layer was uneven, and as a result of forming an air layer with the surface, frost prevention properties, As for heat insulation, although there are differences depending on the type, thickness, adhesion pattern, etc. of the film, both the storage stability and the handleability were good. In Example 10, although frost prevention property and heat insulation were the same, since there was no gas barrier layer, the expiration date was shortened.

  On the other hand, in Comparative Examples 3 and 4, since the first layer did not shrink even after boil sterilization, neither frost prevention nor heat insulation was obtained.

  As described above, since the laminate according to the present invention has the sealant layer on the inner surface, it can be processed into a packaging material such as a sleeve or a packaging bag by a normal processing method. And since wrinkles are generated on the surface by heating, heat insulation is born, and frost adhesion prevention effect and heat insulation effect are exhibited.

DESCRIPTION OF SYMBOLS 1 ... Laminate 2 ... Heat-shrinkable base material layer 3 ... Heat-resistant adhesive layer 4 ... Intermediate | middle layer 5 ... Adhesive layer 6 ... Hot-melt resin layer 7 ... Pattern laminating area 8 ... heat melting area 9 ... chipped portion 10 ... wrinkle 11 due to shrinkage ... air layer 12 ... gas barrier layer 13 ... packaging material 14 ... packaging bag 15 ..Bottle 16 ... heat shrink direction

Claims (5)

A laminate having two or more plastic film layers,
Having a heat-shrinkable base material layer in the first layer which is the outermost layer;
The innermost layer has a heat-melting resin layer having heat sealing properties ,
The first layer and the second layer adjacent to the first layer are laminated by a heat-resistant adhesive layer,
The heat-resistant adhesive layer is formed in a pattern and has a pattern laminate region having a chipped portion of 10% or more, and the heat-resistant adhesive layer has a heat-welded region having no chipped portion, In the glue part, the first layer and the second layer are not bonded,
Having the heat-welded region at the front end and the rear end with respect to the heat shrink direction,
A laminate characterized by the above.   The heat-shrinkable base material layer is a heat-shrinkable polyethylene terephthalate film having a dimensional shrinkage of 10% or more in at least one direction of the flow direction or the width direction when immersed in warm water of 80 ° C. for 10 seconds. The laminate according to claim 1, which is characterized.   The laminate according to claim 1, wherein the laminate includes a gas barrier layer. 請 Motomeko 1 or a laminate according to 2, packaging material, wherein the hot-melt resin layer has the both end portions so that the inwardly formed into thermally welded tubular.   The laminated body according to any one of claims 1 to 3, which has the heat-welded region at a peripheral edge portion, is opposed to the inner surface of the heat-melting resin layer so that the peripheral edge portion is thermally welded into a bag shape. A packaging bag characterized by being molded.

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