JP2015020780A - Lid material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lid material for a sealed container which is inexpensively produced, free from a hygienic problem or degradation of gas barrier property during distribution, and has a function for automatically and stably releasing vapor when heating the container itself by a microwave oven.SOLUTION: A lid material 1 composed of a laminate 10 is used for sealing an opening of a container body 2 by heat-sealing to a flange part 4 of the container body 2, and includes a first layer 11 being an outermost layer composed of a heat-shrinkable film, a second layer 13 composed of an oriented film, and an innermost layer composed of an easily peelable sealant layer 16. An adhesive layer 12 for adhering the first layer and the second layer has a belt-like insufficient adhesive part 5, and the belt-like insufficient adhesive part has the directivity orthogonal or oblique to the heat-shrinking direction of the first layer and is formed across a part of the opening of the container body from one part of the flange part 4 of the container body to the other part of the flange part 4.

Description

  TECHNICAL FIELD The present invention relates to a lid material that is used by being heat-sealed at an opening of a container, and in particular, when a food or the like is stored and the whole container is heated in a microwave oven, a steam vent hole is automatically formed by the temperature and pressure of the generated steam. The present invention relates to a vapor vent lid material that opens to the top.

  Conventionally, when a package containing food is heated as it is in a microwave oven, a steam vent is provided in advance in a part of the container so that the container is not ruptured by the generated water vapor. As an example of such a method, a method of cutting off a corner portion of the packaging bag with a scissors or peeling off a part of the lid material is used.

  However, such a method can cause disastrous consequences if the container is inadvertently left open, causing the container to rupture. Therefore, a packaging container has been proposed in which a steam vent is automatically opened even if the package is heated as it is in a microwave oven.

  The food packaging container with a pressure relief label described in Patent Document 1 is obtained by opening a steam vent hole in advance in the container and sticking the pressure relief label to this hole. The pressure relief label is provided with a non-adhesive area at the center and a weak adhesive area and a strong adhesive area on the outside, so that the weak adhesive area automatically peels off when heated in a microwave oven. While the punch hole is opened, the label does not peel off due to the presence of the strong adhesion region.

Japanese Patent No. 3621071

  In the food packaging container with a pressure relief label described in Patent Document 1, as the structure of the pressure relief label, a weakly adhesive region that peels off due to the heat and pressure of water vapor and a strong adhesive region that does not peel off are applied in an amount of adhesive. Since it is classified according to the difference, it is difficult to exhibit a clear strength difference, and thus stable steam venting performance could not be expected.

  In addition, since the adhesive label is attached to the hole opened in the lid of the container, in addition to the cost of the label itself, it requires not only the penetrating cost and the labeling process cost, but it is not only costly but also essential. In addition, they have anxiety factors about the hygienic and gas barrier properties of the container.

  The problem to be solved by the present invention is that, in a sealed container lid, the cost is low, there is no problem with hygiene, and there is no deterioration in gas barrier properties during distribution. In addition, the present invention proposes a cover material having a function of stably removing steam.

As a means for solving the above-mentioned problems, the invention according to claim 1 is characterized in that the lid member made of a laminate is used for heat-sealing the flange portion of the container body to seal the opening of the container body. A first layer which is an outermost layer made of a heat-shrinkable film, a second layer made of a stretched film, and an innermost layer made of an easy peel sealant layer, and the first layer and the second layer are bonded to each other. The adhesive layer has a band-shaped chipped portion, the band-shaped chipped portion has a direction orthogonal or oblique to the heat shrink direction of the first layer, and the flange portion of the container body The lid member is characterized by being formed across a part of the opening of the container body from one part to the other part of the flange part.

  The lid material according to the present invention has a first layer which is an outermost layer made of a heat-shrinkable film, a second layer made of a stretched film, and an innermost layer made of an easy peel sealant layer. The adhesive layer for bonding the two layers has a band-shaped chipped portion, the band-shaped chipped portion has a direction orthogonal to or oblique to the heat shrink direction of the first layer, and the container body From the part of the flange part of the container to the other part of the flange part, the part of the opening of the container body is straddled. The first layer contracts and acts to lift the easy peel sealant layer. For this reason, a steam vent is automatically opened.

  Moreover, the invention according to claim 2 is the lid according to claim 1, wherein a plurality of the strip-shaped chipped portions are provided in parallel.

  In the invention according to claim 3, the shrinkage rate in the flow direction or the width direction when the heat-shrinkable film as the first layer of the laminate is immersed in a hot water bath at 80 ° C. for 10 seconds is 10%. It is the above polyethylene terephthalate (PET) film, The lid material according to claim 1 or 2.

  Moreover, invention of Claim 4 is a lid | cover material of any one of Claims 1-3 in which the said laminated body has a gas barrier layer.

  The lid according to the present invention has a heat-shrinkable film disposed on the outermost layer and a band-shaped chipped portion provided on the adhesive layer between the second layer. As the shrinkable film shrinks and acts to lift the easy peel sealant layer, the vapor vent hole is automatically opened.

  This effect is brought about by the shrinkability of the heat-shrinkable film, easy peelability of the easy peel sealant layer, and the positional relationship of the chipped portion, so that the operation is stable and the vapor vent hole is reliably opened. To do.

  Moreover, since the lid | cover material which concerns on this invention is a simple structure which only provides a chipping part in the contact bonding layer between a 1st layer and a 2nd layer, it is advantageous also in terms of manufacturing cost.

  When a plurality of strip-shaped chipped portions are provided in parallel as in the invention described in claim 2, the lifting of the lid material due to the shrinkage of the first layer becomes small, so the opening of the steam vent hole Becomes smooth, and the appearance in a state where the vapor hole is opened is improved.

  Further, as in the invention described in claim 3, when the heat-shrinkable film as the first layer of the laminate is immersed in an 80 ° C. hot water bath for 10 seconds, the shrinkage rate in the flow direction or the width direction is 10%. In the case of the above polyethylene terephthalate film, various processing aptitudes including printing processing aptitude are good, and they are easily available.

FIG. 1 is a schematic plan view showing an embodiment of a lid material according to the present invention, and is a schematic plan view showing a state of a package body in which the lid material is heat-sealed to a container body. FIG. 2 is a schematic cross-sectional view showing the A-A ′ cross section of FIG. 1. FIG. 3 is a cross-sectional explanatory view showing a state when the package shown in FIGS. 1 and 2 is heated in a microwave oven. FIG. 4 is a schematic plan view showing another embodiment of the lid according to the present invention, and is a schematic plan view showing a state of a package body in which the lid is heat sealed to the container body. FIG. 5 is a schematic cross-sectional view showing the B-B ′ cross section of FIG. 4.

Hereinafter, the lid according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic plan view showing an embodiment of a lid material according to the present invention, and is a schematic plan view showing a state of a package body in which the lid material is heat-sealed to a container body. FIG. 2 is a schematic cross-sectional view showing the AA ′ cross-section of FIG. 1. FIG. 3 is an explanatory cross-sectional view showing a state when the package shown in FIGS. 1 and 2 is heated in a microwave oven.

  The lid | cover material (1) which concerns on this invention is used in order to heat-seal to the flange part (4) of a container main body (2), and to seal the opening part of a container main body. The material of the container body (2) is not particularly limited, but it is necessary that the container body (2) has a certain degree of rigidity so as not to be deformed together when the lid member (1) contracts.

  The lid material (1) according to the present invention is a lid material made of a laminate (10), and is a first layer (11) which is an outermost layer made of a heat-shrinkable film, and a second layer made of a stretched film ( 13) and at least an innermost layer composed of an easy peel sealant layer (16), and the adhesive layer 1 (12) for bonding the first layer (11) and the second layer (13) has a strip-shaped chipped portion ( 5). In the embodiment shown in FIGS. 1 and 2, the second layer (13) and the easy peel sealant layer (16) are laminated by the adhesive layer 2 (15).

  The band-shaped chipped portion (5) has a direction perpendicular or oblique to the heat shrink direction (6, 7) of the first layer, and the flange portion (4) from a part of the flange portion (4) of the container body (2) is flanged. It is formed across a part of the opening of the container body (2) up to the other part of the part (4).

  In the embodiment shown in FIG. 1, the first layer is shrinkable both in the flow direction and in the width direction, and the chipped portion (5) is at an angle of approximately 45 ° so as to cross both. Is provided.

  As shown in FIG. 3, when the package (3) in which the contents (9) are stored in the container body (2) and the lid (1) is heat-sealed is heated in a microwave oven, the lid (1) In places other than the chipped portion (5), no significant deformation occurs, but in the chipped portion (5), the first layer (11), which is the heat-shrinkable film on the outermost surface, contracts due to the influence of heat, The laminate (10) warps in the surface direction. As a result, the easy peel sealant layer (16) is peeled off at the portion ahead of the chipped portion (5), and the vapor vent hole (17) is automatically opened.

  In the example shown in FIG. 3, the easy peel sealant layer (16) causes cohesive failure in the layer, but the easy peel sealant layer (16) is at the interface with the flange portion (4) of the container body (2). You may design so that it may peel.

As the heat-shrinkable film, a shrink film generally used for shrink packaging or the like can be used. As the material, vinyl chloride resin, polystyrene resin, PET resin, etc. are common. Among these, a PET film having a shrinkage rate in the flow direction or width direction of 10% or more when immersed in an 80 ° C. warm water bath for 10 seconds is most suitable for the lid material of the present invention.

  As the stretched film used as the second layer (13), a known stretched film for packaging material can be used. For example, stretched polypropylene film (OPP), stretched PET film (PET), stretched nylon film (ONy) and the like.

  As the easy peel sealant layer (16), a known easy peel resin for packaging materials or an easy peel film can be used.

  FIG. 4 is a schematic plan view showing another embodiment of the lid (1) according to the present invention, and shows the state of the package (3) in which the lid (1) is heat-sealed to the container body (2). It is the shown plane schematic diagram. FIG. 5 is a schematic cross-sectional view showing the B-B ′ cross section of FIG. 4.

  In the embodiment shown in FIGS. 4 and 5, three strip-shaped chipped portions (5) are provided in parallel. The chipped portion (5) is formed in a direction orthogonal to the heat shrink direction (6) of the heat shrinkable film on the outermost surface.

  In this way, when the strip-shaped chipped portion is constituted by a plurality of parallel chipped portions, the deformation when the cover member is heated becomes small and the opening of the steam vent hole becomes smoother. The appearance at the time of deformation is also good.

  In the embodiment shown in FIGS. 4 and 5, the gas barrier layer (14) is provided on the easy peel sealant layer (16) side of the second layer (13), and the gas barrier layer (14) and the easy peel sealant layer ( 16) are laminated by the adhesive layer 2 (15).

  The gas barrier layer (14) may be a deposited layer obtained by directly depositing aluminum or an inorganic material on one surface of the stretched film as the second layer, or may be an independent layer such as an aluminum foil. Further, a gas barrier film or coating film, or a combination thereof may be used.

  The lid material (1) according to the present invention has a simple configuration that only forms a chipped portion between the first layer and the second layer, and does not adversely affect the gas barrier layer. The original performance is maintained until it is opened. Hereinafter, based on an Example, the lid | cover material which concerns on this invention is demonstrated concretely.

  A shrink PET film (abbreviated as S-PET) having a thickness of 25 μm (TAS made by Gunze) was used as the first layer, and a pattern was printed on the back side by a gravure printing method. This heat-shrinkable film has a shrinkage in the flow direction (MD) of 3% and a shrinkage in the width direction (TD) of 46% when immersed in a hot water bath at 80 ° C. for 10 seconds (hereinafter the same). . As the second layer, a gas barrier film (GL film (trade name) GL-AEY, manufactured by Toppan Printing Co., Ltd.) having an alumina vapor deposition layer on an ONy film having a thickness of 15 μm was used, and this vapor deposition surface side and an easy peel sealant layer (Mitsui Chemical Tosero) (CMPS 013C) was dry laminated.

  Apply the dry laminating adhesive in the pattern shown in Fig. 1 to the pattern printed surface of the first layer to form a chipped portion, and bond it to the easy peel sealant layer and the second layer ONy surface that has been dry laminated. It was. At this time, the drying temperature of the adhesive was set lower than usual so that the shrink PET film did not shrink.

As a container body, a tray-shaped container as shown in FIG. 1 in which a three-layer sheet of PP / EVOH / PP having a thickness of 300 μm was vacuum-formed was prepared, and white rice was filled as the contents. The laminate obtained above was heat-sealed on the flange portion of the container so that the chipped portion was arranged as shown in FIG. 1, and then punched out to obtain a package of Example 1.

  S-PET (TNB manufactured by Gunze) having a thickness of 25 μm was used as the first layer. The shrinkage rate in the flow direction (MD) of this heat-shrinkable film is 26%, and the shrinkage rate in the width direction (TD) is 31%. Further, the adhesive coating pattern was a pattern in which three chipped portions were parallel as shown in FIG. The shape of the container body is an oval shape as shown in FIG. Other than that was carried out similarly to Example 1, and obtained the package of Example 2. FIG.

  A package of Example 3 was obtained in the same manner as Example 1 except that 30 μm thick S-PET (Mitsubishi Resin Corporation RX40S) was used as the first layer. The shrinkage rate in the flow direction (MD) of this heat-shrinkable film is 30%, and the shrinkage rate in the width direction (TD) is 40%.

A package of Example 4 was obtained in the same manner as in Example 1 except that a shrink PS film (abbreviated as S-PS) (GMPS manufactured by Gunze) having a thickness of 30 μm was used as the first layer. The shrinkage rate in the flow direction (MD) of this heat-shrinkable film is -1%, and the shrinkage rate in the width direction (TD) is 40%.

  A package of Example 5 was obtained in the same manner as Example 1 except that S-PET (S2600 manufactured by Toyobo Co., Ltd.) having a thickness of 20 μm was used as the first layer. The shrinkage rate in the flow direction (MD) of this heat-shrinkable film is 15%, and the shrinkage rate in the width direction (TD) is 15%.

<Comparative Example 1>
A package of Comparative Example 1 was obtained in the same manner as in Example 1 except that a normal 25 μm thick PET film (E5100 manufactured by Toyobo Co., Ltd.) having no heat shrinkability was used as the first layer. The shrinkage rate of the PET film under the same conditions is 0% in both the flow direction (MD) and the width direction (TD).

<Comparative example 2>
A package of Comparative Example 2 was obtained in the same manner as in the Example except that the chipped portion was not provided.

Each package obtained as described above is heated for 1 minute at 1900 W output using a commercial microwave oven (NE-EH21A manufactured by Panasonic), and the opening state of the steam vent and the state of steam removal (vapor permeability). I investigated. The case where the lid material swelled from the edge of the lid material near the chipped part and vapor was released from between the lid and the container was evaluated as ○, and the case where the container was deformed or the lid material was ruptured was rated as x. .

Table 1 shows the specifications and evaluation results of Examples and Comparative Examples.

  As can be seen from the results in Table 1, when the lid according to the present invention is heated in a microwave oven, the first layer of the chipped portion contracts, so that a steam vent hole is automatically generated. Since the generated water vapor is removed from the container, the container is not deformed and the lid material is not ruptured.

DESCRIPTION OF SYMBOLS 1 ... Lid 2 ... Container body 3 ... Packaging body 4 ... Flange part 5 ... Fragment part 6, 7 ... Heat-shrink direction 8 ... Water vapor 9 ... Contents Object 10 ... Laminate 11 ... First layer 12 ... Adhesive layer 1
13 ... 2nd layer 14 ... Gas barrier layer 15 ... Adhesive layer 2
16 ... Easy peel sealant layer 17 ... Vapor vent

Claims (4)

  A lid made of a laminate used to heat seal the flange of the container body and seal the opening of the container body, the first layer being the outermost layer made of a heat-shrinkable film, and stretching A second layer made of a film and an innermost layer made of an easy peel sealant layer, and the adhesive layer for bonding the first layer and the second layer has a band-shaped chipped portion, and the band-shaped chipped portion Has a direction perpendicular to or oblique to the direction of heat shrinkage of the first layer, and a part of the opening of the container body from a part of the flange part of the container body to another part of the flange part. A lid material formed by straddling.   The lid member according to claim 1, wherein a plurality of the strip-shaped chipped portions are provided in parallel.   The heat-shrinkable film as the first layer of the laminate is a polyethylene terephthalate film having a shrinkage in the flow direction or width direction of 10% or more when immersed in an 80 ° C. hot water bath for 10 seconds. The lid member according to claim 1 or 2.   The said laminated body has a gas barrier layer, The lid | cover material of any one of Claims 1-3 characterized by the above-mentioned.

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