JP6008447B2 - Sealed film, packaging material and package - Google Patents

Description

The present invention, packaging material such as packaging bag or packaging container for packaging foods to be heated using a microwave oven, etc., packaging materials such as packaging films used for packaging of this, and, the packaging The present invention relates to a sealing film to be attached to a material .

  The contents of various foods and processed foods are sealed in a packaging bag made of packaging film, etc., or the opening of the packaging container containing the contents so that it can be cooked as it is in a microwave oven Many foods that are sealed with packaging film are sold.

  When this type of food is cooked as it is in a microwave oven, the internal pressure of the packaging bag or packaging container excessively rises due to water vapor generated from the contents, etc., thereby opening the packaging film or packaging container constituting the packaging bag. The packaging film that seals the part is ruptured, and the contained contents are scattered outside.

  For this reason, various techniques have been proposed in the past in which holes for steam removal are naturally formed in the bag surface and the lid of the container during heating.

  For example, in Patent Document 1, a part of a heat seal portion of a packaging bag is peeled off by an increase in internal pressure accompanying generation of water vapor or the like when food is heated in a microwave oven, thereby opening a hole. A packaging bag that discharges water vapor and the like inside is disclosed.

JP-A-10-101154

  However, in the conventional example in which the hole is opened by weakening the adhesive strength of a part of the heat seal portion as described above and being peeled by an increase in internal pressure, it is not easy to adjust to peel the hole appropriately and opening the hole, If the area of the peeling part is not appropriate and the hole is too small, the internal pressure will be excessive and the packaging bag will burst, or conversely, if the hole is too large, steam will be discharged from the packaging bag more than necessary and cooking will not be possible. There is a problem that the texture becomes insufficient and the texture decreases.

The present invention has been made in view of the above points, and provides a sealed film, a packaging material, and a package using the same , which can be easily adjusted to an appropriate internal pressure during heat treatment. The purpose is to do.

  In order to achieve the above object, the present invention is configured as follows.

(1) sealing films of the present invention has a vapor release section for releasing the steam produced by the heating, the steam vent packaging material for packaging contents, packaging the steam vent so as to close said vapor vent portion The sealing film is attached to a material, and the sealing film has a shrink film that is shrunk and deformed by heating to peel the sealing film from the packaging material for steam removal and expose the steam releasing portion. The shrink film is a uniaxially stretched shrink film, and the sealing film has a high adhesive strength on one side in the shrinking direction due to heat of the shrink film compared to the other side in the shrinking direction. is adhered to the timber, Monodea on the other side of the sealing film, the half-cut along the direction perpendicular to the shrinkage direction is formed .

  The said sealing film should just have a shrink film, may consist only of a shrink film, and may have another film.

In sealing film of the present invention, for venting packaging material having a vapor release section for releasing the steam produced by the heating, since the sealing film so as to close said vapor vent portion is adhered, Ya various ingredients Contents such as processed food can be stored and sealed in a packaging bag or packaging container made of this packaging material.

  And when the packaging bag and packaging container which stored the content in this way are heat-processed using a microwave oven etc., the shrink film which comprises a sealing film deform | transforms by heat contraction, and a sealing film is for vapor removal Peeling from the packaging material will expose the vapor vent. This steam venting part escapes steam by heating, and is composed of, for example, through holes and notches, and the size, number, shape, position, etc. can be arbitrarily set. It is easy to adjust the amount of escaped steam, and thus the internal pressure and temperature of the packaging bag or packaging container.

As a result, when the heat treatment is performed using a microwave oven or the like, the internal pressure of the packaging bag or packaging container is prevented from excessively rising due to water vapor generated from the contents or the like, thereby forming the packaging bag or packaging container. While the packaging material such as the packaging film can be prevented from being swollen and ruptured, it is possible to prevent the steam from being discharged more than necessary from the packaging bag or the packaging container, resulting in insufficient heat treatment.
Moreover, since the said sealing film is firmly stuck to the packaging material for vapor removal compared with the other side in the shrinkage direction by the heat | fever of a shrink film, at the time of heating, the sticking strength of a sealing film is weak The other side can be deformed so as to be peeled off from the packaging material for steam removal by heat shrinkage of the shrink film and pulled to the one side along the shrinking direction to be wound up, thereby exposing the steam releasing part.
Moreover, since the half cut is formed along the direction perpendicular to the shrinkage direction of the shrink film due to the heat of the shrink film on the other side of the sealing film that is the side to be wound, when pulled to one side of the shrinkage direction In particular, it is deformed so that it can be wound smoothly, and is particularly effective in the case of a relatively thick sealing film.

(2) The sealing film of the present invention has a steam vent for releasing steam generated by heating, and the steam vent packaging of the steam vent packaging material for packaging the contents so as to close the steam vent. The sealing film is attached to a material, and the sealing film has a shrink film that is shrunk and deformed by heating to peel the sealing film from the packaging material for steam removal and expose the steam releasing portion. The steam release packaging material has the steam release part and its peripheral part as recesses, and the sealing film is adhered to the steam release packaging material so as to close the recess, The steam release packaging material is formed with a groove extending outward in the periphery of the recess, and the sealing film is attached to the steam release packaging material so as to close the recess and the groove. It is.

According to the sealing film of the present invention, the steam release packaging material has a recess in the steam release portion and its peripheral portion, so that steam generated from the contents when heated using a microwave oven or the like However, the vapor is introduced into the recess through the vapor vent, and the steam that accumulates in the recess heats the sealed film efficiently, shrinks the shrink film, winds the seal film, and exposes the vapor vent.
Furthermore, when the sealing film is wound up by heating and the groove portion is exposed, it is possible to discharge the vapor accumulated in the concave portion through the groove portion.

(3) The packaging material of the present invention has a steam vent for releasing steam generated by heating, the steam vent packaging material for packaging the contents, and the steam vent packaging so as to close the steam vent. A sealing film adhered to the material, and the sealing film has a shrink film that is shrunk and deformed by heating to peel the sealing film from the packaging material for steam removal and expose the steam venting portion. The shrink film is a uniaxially stretched shrink film, and the sealing film has a high adhesive strength on one side in the shrinkage direction due to heat of the shrink film compared to the other side in the shrinkage direction. A half cut is formed on the other side of the sealing film along a direction orthogonal to the shrinking direction.

In the packaging material of the present invention, since a sealing film is attached to the packaging material for steam venting having a steam venting part for escaping steam generated by heating so as to block the steam venting part, various foodstuffs and processing Contents such as food can be sealed in a packaging bag or packaging container made of this packaging material.
And when the packaging bag and packaging container which stored the content in this way are heat-processed using a microwave oven etc., the shrink film which comprises a sealing film deform | transforms by heat contraction, and a sealing film is for vapor removal Peeling from the packaging material will expose the vapor vent. This steam venting part escapes steam by heating, and is composed of, for example, through holes and notches, and the size, number, shape, position, etc. can be arbitrarily set. It is easy to adjust the amount of escaped steam, and thus the internal pressure and temperature of the packaging bag or packaging container.
As a result, when the heat treatment is performed using a microwave oven or the like, the internal pressure of the packaging bag or packaging container is prevented from excessively rising due to water vapor generated from the contents or the like, thereby forming the packaging bag or packaging container. While the packaging material such as the packaging film can be prevented from being swollen and ruptured, it is possible to prevent the steam from being discharged more than necessary from the packaging bag or the packaging container, resulting in insufficient heat treatment.
In addition, the sealing film is firmly attached to the packaging material for steam removal compared with the other side in the shrinkage direction due to the heat of the shrink film. The other side is peeled off from the packaging material for steam removal by heat shrinkage of the shrink film and deformed so as to be pulled and wound up along the shrinking direction to the one side to expose the steam venting portion.

  Moreover, since the half cut is formed along the direction perpendicular to the shrinkage direction of the shrink film due to the heat of the shrink film on the other side of the sealing film that is the side to be wound, when pulled to one side of the shrinkage direction In particular, it is deformed so that it can be wound smoothly, and is particularly effective in the case of a relatively thick sealing film.

(4) The packaging material of the present invention has a steam vent for escaping steam generated by heating, the steam vent packaging material for packaging the contents, and the steam vent packaging so as to close the steam vent. A sealing film adhered to the material, and the sealing film has a shrink film that is shrunk and deformed by heating to peel the sealing film from the packaging material for steam removal and expose the steam venting portion. The shrink film is a uniaxially stretched shrink film, and the sealing film is bonded to the packaging material for vapor removal by welding, and the welding is a welding strength on one side in a shrinking direction due to heat of the shrink film. and has been higher than the welding strength of the other side of the contraction direction, the sealing film has a shape one side of the rectangular shape in plan view is cut out, Keys window side, the a the heat by the other side of the contraction direction of the shrink film, the sealing film, as connecting the two vertices of the one side, is cut out inwardly of the rectangular.

  As the welding, ultrasonic welding, heat welding, high-frequency welding, or the like can be used.

According to the packaging material of the present invention, since the sealing film is firmly welded to the packaging material for vapor removal compared with the other side on one side in the shrinkage direction due to heat of the shrink film, The other side having a low strength can be deformed so as to be peeled off from the packaging film by heat shrinkage of the shrink film and pulled to the one side to be wound up, thereby exposing the vapor vent.
In addition, when the sealing film is rectangular in plan view, the other side in the shrinkage direction due to heat of the shrink film is weak in welding strength, and therefore, at the time of heating, peeling starts from two apex portions on one side of the other side. However, at that time, the two ends may be wound obliquely inward, and the wound ends may collide near the midpoint of the one side and cannot be wound any further.
According to the packaging material of the present invention, one side of the rectangular sealing film in plan view, which is the other side in the shrinkage direction due to heat of the shrink film, is cut out inward of the rectangle so as to connect two vertices of one side. So, at the time of heating, even if the peeling starts from the two vertices of the one side and is wound obliquely inwardly, it is cut out inwardly of the rectangle, so that the wound ends do not collide with each other When it is wound up to the vicinity of the midpoint of the one side, the notch near the midpoint is also started to be peeled off and wound up.

(5) The packaging material of the present invention has a steam vent for escaping steam generated by heating, the steam vent packaging material for packaging the contents, and the steam vent packaging so as to close the steam vent. A sealing film adhered to the material, and the sealing film has a shrink film that is shrunk and deformed by heating to peel the sealing film from the packaging material for steam removal and expose the steam venting portion. The shrink film is a uniaxially stretched shrink film, the sealing film is adhered to the packaging material for vapor removal via an adhesive layer, and the adhesive layer is contracted by heat of the shrink film. one the adhesive strength of the side, has been higher than the adhesive strength of the other side of the contraction direction, the sealing film, the shape of one side of the rectangular shape in plan view is cut out of the There, the one side end, the a the heat by the other side of the contraction direction of the shrink film, the sealing film, as connecting the two vertices of the one side, is cut out inwardly of the rectangular.

According to the packaging material of the present invention , the sealing film has one side in the shrinkage direction due to heat of the shrink film being firmly adhered to the packaging material for steam removal compared to the other side. The other side having weak strength is peeled off from the packaging material for steam removal due to thermal shrinkage of the shrink film, and is deformed so as to be pulled and wound up along the shrinking direction to the one side, thereby exposing the steam releasing part. it can.
In addition, since one side of the rectangular sealing film in plan view which is the other side of the shrinkage direction due to heat of the shrink film is cut out inward of the rectangle so as to connect two vertices of one side, at the time of heating, Even if peeling is started from two vertices on one side and each is wound inward diagonally, it is notched inward in the rectangle, so that the wound ends do not collide with each other, and the midpoint of the one side When it is wound up to the vicinity, the notch near the middle point starts to be peeled off.

(6) The packaging material of the present invention has a steam vent for escaping steam generated by heating, the steam vent packaging material for packaging the contents, and the steam vent packaging so as to close the steam vent. A sealing film adhered to the material, and the sealing film has a shrink film that is shrunk and deformed by heating to peel the sealing film from the packaging material for steam removal and expose the steam venting portion. The steam release packaging material has a recess in the steam release portion and its peripheral portion, and the sealing film is attached to the steam release packaging material so as to close the recess. In the packaging material for steam release, a groove portion extending outward is formed in the peripheral portion of the recess, and the sealing film is attached to the packaging material for steam removal so as to close the recess and the groove portion.

According to the packaging material of the present invention, the steam venting packaging material has a concave portion at the steam venting portion and its peripheral portion, so that steam generated from the contents when heated using a microwave oven or the like However, the vapor is introduced into the recess through the vapor vent, and the steam that accumulates in the recess heats the sealed film efficiently, shrinks the shrink film, winds the seal film, and exposes the vapor vent.
Furthermore, when the sealing film is wound up by heating and the groove portion is exposed, it is possible to discharge the vapor accumulated in the concave portion through the groove portion.

(7) A packaging material as a reference example of the present invention has a steam vent for releasing steam generated by heating, the steam vent packaging material for packaging the contents, and the steam vent so as to close the steam vent. A sealing film adhered to the packaging material for steam removal, and the sealing film is shrunk and deformed by heating, thereby peeling the sealing film from the packaging material for steam removal and exposing the steam removal part. A shrink film, the shrink film is a uniaxially stretched shrink film, and the sealing film is adhered to the packaging material for vapor removal by welding, and the welding is one of the shrinkage directions of the shrink film due to heat. The welding strength on the side is made higher than the welding strength on the other side in the shrinkage direction.

As the welding, ultrasonic welding, heat welding, high-frequency welding, or the like can be used.
According to the packaging material as a reference example of the present invention, the sealing film is tightly welded to the packaging material for steam removal compared to the other side on the one side in the shrinkage direction due to heat of the shrink film. The other side of the film having a low welding strength can be deformed so as to be peeled off from the packaging film by heat shrinkage of the shrink film and pulled to the one side to be wound up, thereby exposing the vapor vent.

(8) A packaging material as a reference example of the present invention has a steam vent for releasing steam generated by heating, the steam vent packaging material for packaging the contents, and the steam vent so as to close the steam vent. A sealing film adhered to the packaging material for steam removal, and the sealing film is shrunk and deformed by heating, thereby peeling the sealing film from the packaging material for steam removal and exposing the steam removal part. A shrink film, the shrink film is a uniaxially stretched shrink film, the sealing film is adhered to the packaging material for vapor removal via an adhesive layer, and the adhesive layer is formed of the shrink film. The adhesive strength on one side in the shrinking direction due to heat is set higher than the adhesive strength on the other side in the shrinking direction.

According to the packaging material as a reference example of the present invention, the sealing film is tightly bonded to the packaging material for steam removal on one side in the shrinking direction due to heat of the shrink film as compared with the other side. The other side of the film, which has weak adhesive strength, is deformed so that it is peeled off from the packaging material for steam removal by thermal shrinkage of the shrink film and pulled to the one side along the shrinking direction and wound up. Can be exposed.

(9) The packaging material of the present invention has a steam vent for escaping steam generated by heating, the steam vent packaging material for packaging the contents, and the steam vent packaging so as to close the steam vent. A sealing film adhered to the material, and the sealing film has a shrink film that is shrunk and deformed by heating to peel the sealing film from the packaging material for steam removal and expose the steam venting portion. The sealing film is formed by laminating the shrink film and a base film that is not shrunk by heating, the shrink film is a uniaxially stretched shrink film, and the sealing film is formed by a first pressure-sensitive adhesive layer. The shrink film and a second pressure-sensitive adhesive layer having a higher adhesive strength than the first pressure-sensitive adhesive layer, and the shrink film And the base film is laminated to the shrink film via the second pressure-sensitive adhesive layer. In this laminated state, the base film is more than the shrink film. The shrink film extends to one side in the shrinking direction due to heat of the shrink film and does not extend to the other side in the shrinking direction due to heat of the shrink film from the shrink film. It sticks to the said packaging material for vapor | steam removal through the said 2nd adhesive layer of the said 1st adhesive layer and the said extended part of the said base film .

The sealing film is preferably two layers of a shrink film and a base film, but may be a laminated film of three or more layers, and may be two or more layers.
The sealing film preferably has a shrink film as a lower layer and a base film as an upper layer, but may have a shrink film as an upper layer and a base film as a lower layer.
According to the packaging material of the present invention, the base film that is not shrunk by heating can regulate deformation due to heat shrinkage of the shrink film, and when heated, it can be deformed into a more appropriate form to expose the vapor vent part. it can.
Furthermore, according to the packaging material of this invention, the said base film in which the 2nd adhesive layer whose adhesive strength is higher than the said 1st adhesive layer is laminated | stacked on the said shrink film in which the 1st adhesive layer was formed. By doing so, the sealing film can be easily manufactured.
In addition, the base film is laminated on the shrink film, and one side in the shrinking direction of the shrink film due to heat extends beyond the shrink film, and the adhesive strength of the extended portion is higher than that of the first adhesive layer. Since the second pressure-sensitive adhesive layer is strongly bonded to the packaging material for removing steam, the portion of the first pressure-sensitive adhesive layer having a low pressure-sensitive adhesive strength on the other side of the shrinkage direction of the sealing film is heated during heating. The shrink film can be peeled off from the packaging material for steam removal by heat shrinkage, and deformed so as to be pulled and wound up along the shrinking direction to the one side to expose the steam venting portion.

(10) In another embodiment of the packaging material according to (9), the base film is a first base film, and a second base film is provided between the second pressure-sensitive adhesive layer and the shrink film. The second base film is bonded to the shrink film with an adhesive.

In the configuration of the packaging material of (9) above, since the second pressure-sensitive adhesive layer is interposed between the base film and the shrink film, depending on the heating conditions and the like, In some cases, the base film is separated from the pressure-sensitive adhesive layer, and the deformation due to the thermal shrinkage of the shrink film cannot be effectively controlled, and the base film cannot be deformed so as to wind up the sealed film.
On the other hand, according to this embodiment, since the second base film is bonded to the shrink film by an adhesive, the second base film effectively regulates deformation due to thermal shrinkage of the shrink film. At the time of heating, the shrink film and the second base film can be integrated so as to be wound together with the first base film, and the vapor vent can be exposed.

(11) A packaging material as a reference example of the present invention has a steam vent for releasing steam generated by heating, the steam vent packaging material for packaging the contents, and the steam vent so as to block the steam vent. A sealing film adhered to the packaging material for steam removal, and the sealing film is shrunk and deformed by heating, thereby peeling the sealing film from the packaging material for steam removal and exposing the steam removal part. The steam release packaging material includes a shrink film, and the steam release portion and its peripheral portion are recessed portions, and the sealing film is attached to the steam release packaging material so as to close the recess portions. Worn.

According to the packaging material as a reference example of the present invention, the steam venting packaging material has a concave portion in the steam venting portion and its peripheral portion, and therefore when the heat treatment is performed using a microwave oven or the like, from the contents Generated steam or the like is introduced into the recess through the steam vent, and the steam accumulated in the recess heats the sealed film efficiently, shrinks the shrink film, winds up the sealed film, and the steam vent Exposed.

(12) In the packaging material according to any one of (3) to (6), the steam vent is at least one of a through hole, a cut, and a half cut formed in the steam vent packaging material. It is.

  When heat treatment is performed using a microwave oven or the like, the internal pressure of the packaging bag or packaging container configured using the packaging material of the present invention increases due to water vapor generated from the contents, etc., and stress is concentrated on the half-cut portion. By doing so, a steam vent hole is formed through the steam vent packaging material.

  According to this embodiment, when heat treatment is performed using a microwave oven or the like by setting the size, number, shape, position, etc. of through holes, notches, and half cuts, packaging bags or packaging due to water vapor generated from the contents etc. The internal pressure and temperature of the container can be easily adjusted, thereby preventing rupture due to an increase in the internal pressure, while preventing excessive discharge of water vapor and appropriate heat treatment.

  (13) The packaging body of the present invention is a packaging body using the packaging material of the present invention, and the packaging material for steam release constitutes a lid portion that seals the opening of the container containing the contents. Is.

  According to the package of the present invention, when heat treatment is performed using a microwave oven or the like, the internal pressure of the packaging container is prevented from excessively rising due to water vapor or the like generated from the contents or the like, and the packaging constituting the packaging container While the material can be prevented from swelling and rupturing, it is possible to prevent the heat treatment from becoming insufficient due to excessive discharge of water vapor from the packaging container.

  (14) The packaging body of the present invention is a packaging body using the packaging material of the present invention, and the steam release packaging material constitutes a part of a packaging bag for packaging the contents.

  According to the package of the present invention, when the heat treatment is performed using a microwave oven or the like, the internal pressure of the packaging bag is prevented from excessively rising due to water vapor generated from the contents, etc., and the packaging bag is swollen and ruptured. On the other hand, it is possible to prevent water vapor from being unnecessarily discharged from the packaging bag and insufficient heat treatment.

  When a packaging bag or packaging container composed of the packaging material of the present invention is heat-treated using a microwave oven or the like, the shrink film constituting the sealed film is deformed by heat shrinkage, and the sealed film is used for degassing. Since the steam vent is exposed by peeling from the packaging material, for example, by setting the size, number, shape, position, etc. of the through-holes, cuts, etc. as appropriate, constituting the steam vent, etc. When using and heat-processing, it becomes possible to adjust the internal pressure and temperature of a packaging bag or a packaging container. As a result, when heat treatment is performed using a microwave oven or the like, it is possible to prevent the internal pressure from excessively rising and rupture of the packaging bag or the like, while preventing water vapor from being discharged more than necessary. Appropriate heat treatment becomes possible.

FIG. 1 is a cross-sectional view of a packaging container according to an embodiment of the present invention. FIG. 2 is a plan view of FIG. FIG. 3 is an enlarged cross-sectional view of the main part of FIG. FIG. 4 is a partially enlarged cross-sectional view showing another configuration of the first and second adhesive layers 6a and 6b. FIG. 5 is a cross-sectional view corresponding to FIG. FIG. 6 is a cross-sectional view corresponding to FIG. 3 showing another configuration of the steam vent. FIG. 7 is a plan view corresponding to FIG. 2 of another embodiment. FIG. 8 is a cross-sectional view corresponding to FIG. 3 showing another configuration of the steam vent. FIG. 9 is a cross-sectional view corresponding to FIG. 3 showing another configuration of the steam vent. FIG. 10 is a sectional view corresponding to FIG. 3 of still another embodiment. FIG. 11 is a cross-sectional view for explaining the structure of the sealing film of FIG. FIG. 12 is a cross-sectional view corresponding to FIG. 3 of another embodiment. FIG. 13 is a cross-sectional view for explaining the structure of the sealing film of FIG. FIG. 14 is a plan view corresponding to FIG. 2 showing an example of a defect in the wound state of the sealing film. FIG. 15 is a plan view corresponding to FIG. 2 of another embodiment. FIG. 16 is a plan view corresponding to FIG. 2 of still another embodiment. FIG. 17 is a plan view corresponding to FIG. 2 of another embodiment. FIG. 18 is a cross-sectional view corresponding to FIG. 1 of another embodiment. FIG. 19 is a plan view of the embodiment of FIG. FIG. 20 is a plan view of still another embodiment. 21 is an enlarged cross-sectional view of the main part of FIG. FIG. 22 is a plan view of another embodiment. FIG. 23 is an enlarged cross-sectional view of the main part of FIG. FIG. 24 is a cross-sectional view of a main part of still another embodiment. FIG. 25 is a plan view of another embodiment. FIG. 26 is an enlarged cross-sectional view of the main part of FIG. FIG. 27 is a cross-sectional view of a packaging bag according to another embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view of a packaging container 1 as a packaging body according to an embodiment of the present invention, and FIG. 2 is a plan view thereof.

  A packaging container 1 according to this embodiment includes a container 2 in which contents (not shown) such as microwave-cooked food are stored, and a steam vent as a steam vent that closes the opening 2a of the container 2 and releases steam during heating. A lid portion 4 made of a packaging film as a packaging material for vapor removal in which a cut 3 for vapor is formed and a peripheral region including the vapor removal cut 3 of the lid 4 are adhered to seal the vapor vent hole 3. The container 2 is sealed with the sealing film 5 and the lid 4 in a state before cooking.

  The container 2 is made of, for example, a synthetic resin such as polypropylene, and a flange 2b extending outward is provided around the opening 2a for storing the contents. In this embodiment, the container 2 is For example, a rectangular shape in plan view.

  The lid part 4 closes the opening 2a of the storage part of the container 2, and is adhered to the flange part 2b of the container 2 by, for example, heat sealing. The packaging film constituting the lid portion 4 is not particularly limited, and a known film such as a polyethylene (PE) film or a polypropylene (PP) film can be used, and may be a laminated film.

  As shown in the partially enlarged cross-sectional view of FIG. 3, the lid portion 4 is formed with the above-described steam vent notch 3 penetrating in the thickness direction. In this embodiment, the lid portion 4 is shown in FIG. In this way, a discontinuous steam vent cut 3 having a substantially C shape in plan view is formed.

  The steam venting cut 3 is not limited to a C shape, and may be, for example, a straight cut, a cross cut, or other shapes, and the size, number, and formation position thereof are set as necessary. do it.

  A rectangular sealing film 5 is adhered to the lid portion 4 by a first adhesive layer 6a and a second adhesive layer 6b so as to close the steam-cutting notch 3 and its peripheral portion. As shown in FIG. 2, the sealing film 5 has a rectangular shape in plan view, but is not limited to a rectangular shape, and may be a circular shape, a triangular shape, or other shapes.

  As an adhesive for each of the adhesive layers 6a and 6b, for example, an adhesive such as polyurethane, polyethylene or polyester can be used, but it is preferable to use an adhesive for food. Moreover, in order to prevent the penetration | invasion of oxygen etc. into the container 2 from the outside, it is preferable to have a high gas barrier property.

  The first adhesive layer 6a has weaker adhesive strength than the second adhesive layer 6b and can be peeled off. The first adhesive layer 6a occupies most of the rectangle of the sealing film 5 shown in FIG. The first area A1 is bonded.

  The second adhesive layer 6b has a strong adhesive strength so that it cannot be peeled off. The second adhesive layer 6b has a diagonal line along the short side on the right side of the rectangular sealing film 5 shown in FIG. Two areas A2 are bonded.

  In this embodiment, the application area | region of the 1st, 2nd adhesive agent with respect to the sealing film 5 was divided | segmented, and the 1st adhesive layer 6a of 1st area | region A1 and the 2nd adhesive layer 6b of 2nd area | region A2 were formed. However, as another embodiment of the present invention, the first and second adhesives are applied so as to overlap, and the first adhesive layer 6a in the first area A1 and the second adhesive layer 6b in the second area A2 May be formed.

  That is, as shown in FIG. 4A, the first adhesive layer 6a is formed by applying the first adhesive to the entire surface of the sealing film 5 including the first area A1 and the second area A2. And the second adhesive layer 6b may be formed by applying a second adhesive to the second region A2 on the first adhesive layer 6a, or as shown in FIG. The second adhesive is applied to the entire surface of the sealing film 5 including the first region A1 and the second region A2 to form the second adhesive layer 6b, and the second adhesive layer 6b on the second adhesive layer 6b is formed. The first adhesive layer 6a may be formed by applying the first adhesive to one region A1. In any case, in the first region A1 of the sealing film 5, the first adhesive layer 6a having a low adhesive strength faces the lid portion 4, and the second region A2 has a second adhesive layer 6b having a high adhesive strength. It will face the lid 4.

  In this embodiment, as shown in FIGS. 1 and 3, the sealing film 5 is a laminated film of a shrink film 7 that shrinks due to heat and a base film 8 that is made of a resin film that does not shrink due to heat. Although the film 7 is a lower layer and the base film 8 is an upper layer, they may be laminated conversely. Further, a print layer may be provided between the shrink film 7 and the base film 8, or a print layer may be provided on the surface of the base film 8.

  In this embodiment, the shrink film 7 is, for example, a uniaxially stretched polystyrene film (OPS), and the base film of the upper layer is, for example, a PET (polyethylene terephthalate) film.

  The shrink film 7 made of a uniaxially stretched polystyrene film contracts along the left-right direction indicated by the arrow B in FIG. 2 by heating. The shrink film 7 constituting the lower layer of the sealing film 5 has its entire lower surface adhered to the lid portion 4 by the first and second adhesive layers 6a and 6b. Therefore, it is possible to prevent foreign matter from entering.

  Further, the shrink film 7 is firmly bonded so that the first area A1 shown in FIG. 2 can be peeled off and the second area A2 cannot be peeled off. That is, the rectangular shrink film 7 is an end portion on one side (right side in this example) of the heat shrinkage direction indicated by the arrow B, and the second region A2 extending in the direction orthogonal to the heat shrinkage direction, The first region A1 which is the other side in the heat shrinkage direction, which is the remaining region, is adhered so as to be able to be peeled off. Moreover, in order to raise adhesive strength rather than the cover part 4 side, the anchor film is given to the shrink film 7. FIG.

  The base film 8 made of an upper PET film of the shrink film 7 is not stretched and contracted and restricts deformation of the shrink film 7 due to heat shrinkage.

  The shrink film 7 having heat shrinkability is not limited to the uniaxially stretched polystyrene film, but other shrink films such as shrink PET film, shrink PE (polyethylene) film, shrink PP (polypropylene) film, shrink PV (polychlorinated). Vinyl) film or hybrid shrink film that is a laminated system of PS (polystyrene) and PET (polyethylene terephthalate) can be used, and not only uniaxial stretching but also biaxial stretching shrink film may be used. .

  The base film 8 is not limited to the PET film, and other resin films such as an OP (biaxially stretched polypropylene) film and a PE film can be used.

  As a combination of the shrink film 7 and the base film 8, in addition to the above-mentioned shrink OPS and PET, for example, shrink PET and PET, hybrid shrink and PET, shrink PET and OP, shrink OPS and OP, hybrid shrink and OP Combinations are preferred.

  If the packaging container 1 comprised as mentioned above is cooked with a microwave oven, the shrink film 7 will shrink | contract along the arrow B direction of FIG. 2 by heating. At this time, the second region A2 is firmly bonded by the second adhesive layer 6b, while the first region A1 is detachably bonded by weak adhesive strength by the first adhesive layer 6a. The film 7 is peeled off from the first region A1 by heat shrinkage, and its deformation is restricted by the outer base film 8, so that the second adhesive layer 6b bonded to the second adhesive layer 6b as shown in FIG. It shrinks and deforms so as to be wound into the region A2 by internal winding. This exposes the steam vent cut 3 in the lid 4.

  On the other hand, the internal pressure of the packaging container 1 rises due to water vapor or the like generated from the contents of the packaging container 1, but the steam venting notch 3 is exposed as described above, so that the steam venting notch 3 penetrating the lid portion 4 is passed through. As shown in FIG. 5, water vapor or the like in the packaging container 1 is discharged to the outside and the internal pressure in the packaging container 1 is prevented from excessively rising, and the lid portion 4 is ruptured to bring the contents to the outside. There is no scattering.

  Moreover, since the steam in the packaging container 1 can be prevented from being excessively discharged by the notch 3 for removing the steam, the contents can be steamed while maintaining the inside of the packaging container 1 at a required internal pressure, Appropriate cooking can be performed, and steam is not exhausted excessively, and the texture does not deteriorate.

  Since the sealing film 5 is contracted and deformed by heating in this way to expose the steam vent cut 3, the steam generated by the heating is discharged by setting the size, shape, number, or position of the steam vent cut 3. The amount can be adjusted, and therefore the internal pressure and temperature of the packaging container 1 can be adjusted. For example, as in the above-described conventional example, the size of the hole for removing steam is defined by the degree of peeling. Adjustment becomes easy.

  In addition, the timing at which the shrink film 7 is peeled off from the lid portion 4 to expose the steam vent cut 3 is selected by selecting the material and shape of the shrink film 7 and the adhesive of the first adhesive layer 6a. It is possible to adjust the internal pressure and temperature of the packaging container 1 more easily.

  Furthermore, in this embodiment, when the shrink film 7 is peeled off from the lid portion 4, the adhesive layer 6a is peeled off together with the shrink film 7, so that no adhesive remains on the lid portion 4 side. 7 is deformed by the outer base film 8 and is wound inward together with the adhesive layer 6a, so that the adhesive layer 6a is not exposed to the outside and the adhesive adheres to the hand. Absent.

  In this embodiment, the steam vent for releasing steam at the time of heating is configured by the incision 3. However, as another embodiment of the present invention, for example, a through hole 3a may be used as shown in FIG. Note that the size, number, shape, and the like of the through hole 3a can be arbitrarily set.

  FIG. 7 is a plan view of another embodiment in which a plurality of (four in this example) through-holes 3a are formed as the vapor venting portions, and parts corresponding to those in FIG.

  When the steam vent is the through-hole 3a, the first adhesive layer 6a communicates with the inside of the container 2 in the configuration of the above-described embodiment, and the adhesive of the first adhesive layer 6a is the food in the container 2. There is a risk of directly touching the contents.

  Therefore, in the embodiment of FIG. 7, among the rectangular first region A1 described above, the region A1 ′ surrounded by the through-hole 3a and the surrounding broken lines is a region where no adhesive is applied, and the first adhesive is used. The layer 6a is formed in a rectangular ring shape so as to surround the region A ′ where the adhesive is not applied. Other configurations are the same as those of the above-described embodiment. In addition, the structure which interposes the area | region which does not apply | coat an adhesive agent to the through-hole 3a and the area | region of the periphery like this embodiment is applicable not only in the case where a steam vent is a through-hole but in the case of a notch | incision etc. Of course.

  Moreover, as a vapor release part, as shown in FIG.8 and FIG.9, it is good also as a half cut 3b, such as V shape. In the case of half-cut 3b, when heat treatment is performed using a microwave oven or the like, the internal pressure of the packaging container 1 increases due to water vapor generated from the contents and the like, and stress concentrates on the tip of the half-cut 3b portion. A steam vent is formed through the lid 4 made of the packaging film. In the case of this half cut 3b, it is completely sealed by the lid 4 at the normal time before the heat treatment.

  In addition, you may comprise a steam vent part combining the cut 3, the through-hole 3a, and the half cut 3b.

  In each of the embodiments described above, the first and second adhesive application areas for the sealing film 5 are made different to form the first area A1 having a low adhesive strength and the second area A2 having a high adhesive strength. Since it is the manufacturing top surface that makes the application area different, the sealing film 5 may be configured as follows as another embodiment of the present invention.

FIG. 10 is a partially enlarged cross-sectional view of the vicinity of the center of the lid 4 corresponding to FIG. 3 described above. Sealing film 5 ₁ of FIG. 10, a first pressure-sensitive adhesive layer 6a _1, shrink the film 7, a strong second adhesive layer 6b ₁ having adhesive strength than the first pressure-sensitive adhesive layer 6a _1, the base film 8 And.

In the sealing film 5 _1, releasably adhered by a first adhesive layer 6a ₁ weak adhesive strength than the second adhesive layer 6b _1, the first region A1 on the lid portion 4 shown in FIG. 2 described above Then, the second region A2 shown in FIG. 2 is bonded to the lid portion 4 by the second adhesive layer 6b _{1 having} a strong adhesive force.

The sealing film 5 ₁ includes a shrink film 7 shown in FIG. 11 (a) on the tack film having a first adhesive layer 6a _1, the substrate film 8 shown in greater FIG 11 (b) than the tack film and a second pressure-sensitive adhesive layer 6b ₁ able to be formed by stacking, the sealing film 5 _1, adhered via a first, second adhesive layer 6a _1, 6b ₁ to the lid portion 4 .

In the sealing film 5 _1, on tack film of FIG. 11 (a), by laminating a tack film of FIG. 11 (b), the base film 8 to the second pressure-sensitive adhesive layer 6b ₁ is formed, the The one adhesive layer 6a ₁ extends from the shrink film 7 on one side (the right side in FIGS. 10 and 11) in the shrinking direction of the shrink film 7 due to heat, and this extended portion is the first adhesive. than a layer 6a ₁ becomes the second region A2 shown in FIG. 2 of a second adhesive layer 6b ₁ strong adhesion.

According to this embodiment, the first and second pressure-sensitive adhesive layers 6a ₁ and 6b ₁ having different adhesive strengths can be formed simply by laminating two types of tack films, so that the sealing film 5 of the above-described embodiment is used. In addition, it is not necessary to make the application areas of the first and second adhesives having different adhesive strengths different, and the manufacture becomes easy.

In sealing film 5 ₁ of FIG. 10, between the shrink film 7 and the substrate film 8 to shrink by heat, to the second pressure-sensitive adhesive layer 6b ₁ is interposed, depending heating conditions, shrink When the film 7 is thermally shrunk, the shrink film 7 is separated from the second pressure-sensitive adhesive layer 6b ₁ , and the base film 8 cannot effectively regulate the deformation due to the heat shrinkage of the shrink film 7, so that You can not wind the film 5 ₁ in the inner winding, sometimes wrinkled shrink film 7 due to shrinkage occurs.

Accordingly, another embodiment of the present invention, as shown in FIG. 12 corresponds to FIG 10, the substrate film of the second adhesive layer 6b on _one, when the first base film _81, between the shrink film 7 and the second adhesive layer 6b _1, the resin film does not shrink by heat, for example, constituting the sealing film 5 ₂ provided second base film ₈₂ made of PET. The shrink film 7 and the ₂ second base film 8, instead of the adhesive, adheres firmly by a strong bonding strength adhesive.

As shown in FIG. 13A, the sealing film 5 ₂ is formed by bonding the shrink film 7 and the second base film 8 ₂ with an adhesive to form the first pressure-sensitive adhesive layer 6 a ₁ on the shrink film 7. A tack film having the first base film 8 ₁ and the second pressure-sensitive adhesive layer 6b ₁ shown in FIG. 13B can be laminated on the tack film. In this laminated state, the shrinkage direction of the one base film 8 ₁ on which the second pressure-sensitive adhesive layer 6b ₁ is formed by the heat of the shrink film 7 rather than the shrink film 7 on which the first pressure-sensitive adhesive layer 6a ₁ is formed. 2 extending to one side (the right side of FIGS. 12 and 13), and the extended portion is shown in FIG. 2 comprising the second pressure-sensitive adhesive layer 6b _{1 having} a stronger adhesive strength than the first pressure-sensitive adhesive layer 6a ₁ . This is the second area A2.

In sealing film 5 ₂ of FIG. 12, shrink the film 7, the second base film ₈₂ is firmly bonded, deformation second base film 8 of shrink film 7 to be thermally contracted by heating ₂ and the shrink film 7 and the second base film 8 ₂ are integrally formed and contracted and deformed so as to be wound up by the inner winding together with the second adhesive layer 6b ₁ and the first base film 8 _1. Then, the steam release notch 3 of the lid 4 is exposed.

  In the embodiment described above, the sealing film 5 has a rectangular shape in plan view as shown in FIG. 2 described above. However, depending on the size of the sealing film 5 and the degree of heating, the sealing film 5 is shown in FIG. 14 corresponding to FIG. In addition, each end of the first area A1 is wound obliquely inwardly as indicated by an arrow C, and the wound ends are collided near the midpoint of one side of the rectangle and wound further. There are cases where it is not possible.

Accordingly, another embodiment of the present invention, as shown in FIG. 15, to be curved from both vertices 5 ₃ a, ₃ b of the short side of the first area A1 of the sealing film ₃ rectangles inwards It is good also as a notch shape. In this example, the line is symmetric with respect to the bisector in the width direction (vertical direction in FIG. 15), but it may not be line symmetric.

By adopting such a shape, even when the two vertices 5 ₃ a and 5 ₃ b are wound inward at the time of heating, the wound ends do not collide with each other, and to the vicinity of the midpoint of one side As the winding progresses, the winding around the middle point also starts and the winding progresses as a whole, and the steam vent cut 3 of the lid 4 is exposed.

The notch shape from the two vertices 5 ₃ a and 5 ₃ b to the inside of the rectangle may be an arc shape, a U shape, a V shape or other shapes.

Further, as another embodiment, as shown in FIG. 16, and the both corner section 5 ₄ a, ₄ b of one side of the first area A1 in plan view a rectangular sealing film 5 ₄ and R shape.

In the sealing film 5 _4, when heated, both corner portions 5 ₄ a, 5 rather than ₄ to peel from b only is wound starting inwardly, delamination begins at about the same time also around the midpoint of one side Then, since it is wound inwardly, the winding progresses as a whole, and the steam vent cut 3 of the lid 4 is exposed.

The sealing film 5 ₄ is effective when the smaller size relative to the sealing film ₃ in FIG. 15.

Figure 17 is a sealing film 5 ₅ by welding a plan view of the embodiment welded to the lid portion 4, portions corresponding to FIG. 2 described above, the same reference characters.

In this embodiment, a plurality of (three in this example) through-holes 3a are formed in the lid portion 4 as a steam vent, and an isosceles triangular sealing film 5 ₅ is formed so as to close these through-holes 3a. Is attached to the lid 4 by welding, for example, ultrasonic welding.

The sealing film 5 ₅ base of the isosceles triangle is disposed along a direction perpendicular to the heat shrinkage direction B of the shrink film 7, the second region A2 of the bottom side shown by oblique lines, the entire surface ultrasonic welding Then, ultrasonic welding is performed linearly along two sides of the isosceles triangle. The linear welded portion has a line width of, for example, 0.2 mm so that the strength of the weld is weakened so that the shrink film 7 can be peeled off when heated. This corresponds to the peelable first region A1 of the embodiment.

In this embodiment, at the time of heating, by the heat shrinkage of the shrink film 7, the sealing film 5 _5, modified as welding strength is wound from the top portion of the apex angle of the weak isosceles triangle in the second region A2 side of the base Thus, the through hole 3a for removing the vapor can be exposed.

  The second region A2 is not ultrasonically welded to the entire surface, but is ultrasonically welded linearly so as to extend in a direction orthogonal to the heat shrink direction B of the shrink film 7, and the line width is set to, for example, You may make it weld firmly as 3 mm. Moreover, you may make it weld firmly by providing linear ultrasonic welding in multiple places.

In each above-mentioned embodiment, although the cover part 4 was a film form, not only a film form but a thin plate form may be sufficient. In this case, the lid 4 is shown in the cross-sectional view of FIG. 18 and the plan view of FIG. 19 so that the portion of the sealing film 5 is intensively heated by the steam and is smoothly wound by the shrink film 7. as it may be a recess 4 ₁ recessed notch cut 3 and its peripheral portion for venting.

According to this embodiment, when heat-treated in a microwave oven or the like, steam or the like generated from the contents of is introduced into the recess 4 ₁ through a steam vent notch 3, the vapor accumulated in the recess 4 _1, The sealing film 5 is efficiently heated and the shrink film 7 is contracted, and the sealing film 5 is wound up to expose the steam vent cut 3.

Further, as another embodiment, the recess 4 _1, the peripheral portion of the direction of the heat shrinkage shrink film 7, as shown in an enlarged sectional view of a main part of a plan view and FIG. 21 in FIG. 20, a plurality of grooves 4 ₂ may be formed.

These plurality of grooves 4 ₂ is continuous with the concave portion 4 ₁ is one end side, at the time of heating, by the heat shrinkage of the shrink film 7, by the sealing film 5, a plurality of grooves 4 ₂ is wound up to the position to be exposed, Steam or the like generated from the contents is discharged to the outside through the steam release notch 3, the recess 4 _1, and the groove 4 ₂ .

In this case, the sealing film 5, since a plurality of grooves 4 ₂ need be wound to the position where the exposed, as shown in FIGS. 22 and 23, the adhesive strength is weak, peelable first adhesive layer 6a While narrowing the formed first region A1 along the direction of heat shrinkage indicated by the arrow B, the second region A2 where the second adhesive layer 6b having a strong adhesive strength is formed is widened. sealing film 5 may also be a plurality of grooves 4 ₂ is not wound only to the position to be exposed.

Further, as the sealing film 5 may be used sealing film 5 a _second arrangement of Figure 12 described above. Figure 24 is a case of using the sealing film 5 _2, similar to FIG. 23, a main case sealing film 5 _2, which is adapted a plurality of grooves 4 ₂ is not wound only to the position that exposes It is an expanded sectional view of a part.

The sealing film 5 _2, as described above, first the adhesive layer 6a ₁ weak adhesion, the shrink film 7, the second base film _82, adhesive strength than the first adhesive layer 6a ₁ Strong second pressure-sensitive adhesive layer 6b ₁ and first base film 8 ₁ are provided.

As described with reference to FIG. 13, the sealing film 5 ₂ is a tack in which the shrink film 7 and the second base film 8 ₂ are bonded with an adhesive, and the first adhesive layer 6 a ₁ is formed on the shrink film 7. A tack film having the first base film 8 ₁ and the second pressure-sensitive adhesive layer 6b ₁ can be laminated on the film.

In FIG. 24, similarly to FIG. 23, the second base film 8 ₂ , the shrink film 7, and the _second film are sealed so that the sealing film 52 can only be wound up to the position where the plurality of grooves 4 ₂ are exposed during heating. portion of the tack film consisting of first pressure-sensitive adhesive layer 6a _1, i.e., the first area A1 in which the first pressure-sensitive adhesive layer 6a ₁ peelable are formed is provided so as to cover the plurality of grooves 4 _2.

During heating, the sealing film 5 _2, the heat shrinkage of the shrink film 7, vapor or the like first peeled from the adhesive layer 6a _1, a plurality of grooves 4 ₂ is taken up to a position to be exposed, generated from the contents of the steam vent notch 3 is discharged to the outside through the recess 4 ₁ and the grooves 4 _2.

  Further, as another embodiment of the present invention, in the case where the thickness of the base film constituting the sealing film is relatively thick, the sealing film is formed so that the sealing film is smoothly wound during heating. May form a half cut along a direction orthogonal to the shrinkage direction of the shrink film due to heat.

25 and 26 are a plan view and an enlarged cross-sectional view of the main part showing an embodiment in which the half cut 10 is formed on the sealing film 5 ₂ ′.

Sealing film 5 ₂ of this embodiment 'in this section of the specification thickening the first base film ₈₁ of the thickness of the sealing film 5 ₂ shown in FIG. 24, the first base film ₈₁ and the second adhesive A half cut 10 is formed across the agent layer 6b ₁ .

  As shown in FIG. 25, a plurality of half cuts 10 are formed along a direction orthogonal to the shrinking direction of the shrink film 7 indicated by the arrow B due to heat. The number, length, position, or depth of the half cuts 10 may be set as necessary, and the half cuts 10 may be discontinuous along the orthogonal direction.

Since the half cut 10 is formed so as to be orthogonal to the direction of shrinkage of the shrink film 7 due to heat, the second adhesive is peeled off from the lid 4 during heating and is on one side of the shrink direction. When pulled to the layer 6b ₁ , the sealing film 5 ₂ ′ is smoothly wound up, and the plurality of grooves 4 ₂ are exposed.

  The present invention is not limited to the packaging container 1 described above, and may be applied to a packaging bag 9 configured by heat-sealing the end of the packaging film 4a as shown in FIG. 27, for example. The packaging film 4a constituting the packaging bag 9 is formed with, for example, a steam vent cut 3 as a steam vent, and the shrink film 7 and the base film 8 are interposed via the first and second adhesive layers 6a and 6b. A sealing film 5 made of is attached.

  In the above-described embodiment, the sealing film 5 includes the base film 8. However, as another embodiment of the present invention, the base film 8 may be omitted and only the shrink film 7 may be configured.

  In the present invention, it is needless to say that each configuration of each of the above-described embodiments, for example, each configuration such as a sealing film, adhesion between the sealing film and the lid, a steam vent, a lid, and the like may be appropriately combined.

  The present invention is not limited to cooking of food by a microwave oven or the like, but can also be applied to cases where a packaging bag or packaging container in which a medical instrument or the like is packaged is subjected to a heat sterilization treatment.

1 package 2 container 3 vapor vent notch 4 lid 4a packaging film 5 _{1-5 5} sealing film 7 shrink film 8 base film 3a venting through-hole 3b venting for half-cut 9 packaging bag

Claims (11)

It is a sealing film that has a steam vent for releasing steam generated by heating, and is attached to the steam vent packaging material so as to close the steam vent of the steam vent packaging material that wraps the contents. And
The sealing film has a shrink film that is shrunk and deformed by heating, thereby peeling the sealing film from the steam release packaging material and exposing the steam release part,
The shrink film is a uniaxially stretched shrink film,
The sealing film is attached to the packaging material for steam removal with one sticking strength higher than the other shrinking direction on the one side in the shrinking direction due to heat of the shrink film,
On the other side of the sealing film, a half cut is formed along a direction orthogonal to the shrinking direction.
A sealing film characterized by that. It is a sealing film that has a steam vent for releasing steam generated by heating, and is attached to the steam vent packaging material so as to close the steam vent of the steam vent packaging material that wraps the contents. And
The sealing film has a shrink film that is shrunk and deformed by heating, thereby peeling the sealing film from the steam release packaging material and exposing the steam release part,
In the steam release packaging material, the steam release portion and its peripheral portion are concave portions,
The sealing film is attached to the packaging material for vapor removal so as to close the concave portion,
The steam release packaging material is formed with a groove extending outward in the periphery of the recess,
The sealing film is attached to the packaging material for steam removal so as to close the recess and the groove.
A sealing film characterized by that. A steam vent packaging material for evacuating steam generated by heating and packaging contents, and a sealing film adhered to the steam vent packaging material so as to close the steam vent portion Prepared,
The sealing film has a shrink film that is shrunk and deformed by heating, thereby peeling the sealing film from the steam release packaging material to expose the steam release part,
The shrink film is a uniaxially stretched shrink film,
The sealing film is attached to the packaging material for steam removal at one side in the shrinking direction due to heat of the shrink film with a higher sticking strength than the other side in the shrinking direction,
On the other side of the sealing film, a half cut is formed along a direction orthogonal to the shrinking direction.
A packaging material characterized by that. A steam vent packaging material for evacuating steam generated by heating and packaging contents, and a sealing film adhered to the steam vent packaging material so as to close the steam vent portion Prepared,
The sealing film has a shrink film that is shrunk and deformed by heating, thereby peeling the sealing film from the steam release packaging material to expose the steam release part,
The shrink film is a uniaxially stretched shrink film,
The sealing film is attached to the packaging material for vapor removal by welding,
The welding has a higher welding strength on one side in the shrinking direction due to heat of the shrink film than the welding strength on the other side in the shrinking direction,
The sealing film has a shape in which one side of a rectangle in plan view is cut out, and the one side is the other side in the shrinking direction of the shrink film due to the heat,
The sealing film is cut out inward of the rectangle so as to connect the two vertices of the one side.
A packaging material characterized by that. A steam vent packaging material for evacuating steam generated by heating and packaging contents, and a sealing film adhered to the steam vent packaging material so as to close the steam vent portion Prepared,
The sealing film has a shrink film that is shrunk and deformed by heating, thereby peeling the sealing film from the steam release packaging material to expose the steam release part,
The shrink film is a uniaxially stretched shrink film,
The sealing film is attached to the packaging material for vapor removal via an adhesive layer,
The adhesive layer has a higher adhesive strength on one side in the shrinkage direction due to heat of the shrink film than the adhesive strength on the other side in the shrinkage direction,
The sealing film has a shape in which one side of a rectangle in plan view is cut out, and the one side is the other side in the shrinking direction of the shrink film due to the heat,
The sealing film is cut out inward of the rectangle so as to connect the two vertices of the one side.
A packaging material characterized by that. A steam vent packaging material for evacuating steam generated by heating and packaging contents, and a sealing film adhered to the steam vent packaging material so as to close the steam vent portion Prepared,
The sealing film has a shrink film that is shrunk and deformed by heating, thereby peeling the sealing film from the steam release packaging material to expose the steam release part,
In the steam release packaging material, the steam release portion and its peripheral portion are concave portions,
The sealing film is attached to the packaging material for steam removal so as to close the concave portion,
The steam release packaging material is formed with a groove extending outward in the periphery of the recess,
The sealing film is adhered to the packaging material for steam removal so as to close the recess and the groove.
A packaging material characterized by that. A steam vent packaging material for evacuating steam generated by heating and packaging contents, and a sealing film adhered to the steam vent packaging material so as to close the steam vent portion Prepared,
The sealing film has a shrink film that is shrunk and deformed by heating, thereby peeling the sealing film from the steam release packaging material to expose the steam release part,
The sealing film is formed by laminating the shrink film and a base film that does not shrink by heating,
The shrink film is a uniaxially stretched shrink film,
The sealing film includes the shrink film on which the first pressure-sensitive adhesive layer is formed, the second pressure-sensitive adhesive layer having a higher adhesive strength than the first pressure-sensitive adhesive layer, and the base material larger than the shrink film. And having a film
The base film is laminated on the shrink film via the second pressure-sensitive adhesive layer, and in this laminated state, the base film is on one side in the shrinking direction due to heat of the shrink film rather than the shrink film. It extends and does not extend to the other side of the shrink direction due to heat of the shrink film than the shrink film,
The sealing film is attached to the packaging material for steam removal via the first pressure-sensitive adhesive layer of the shrink film and the second pressure-sensitive adhesive layer of the extended portion of the base film. ,
A packaging material characterized by that. The base film is a first base film,
A second base film is interposed between the second pressure-sensitive adhesive layer and the shrink film,
The second base film is adhered to the shrink film by an adhesive;
The packaging material according to claim 7 . The steam vent is at least one of a through hole, a cut, and a half cut formed in the steam vent packaging material.
The packaging material according to any one of claims 3 to 6 . A package using the packaging material according to any one of claims 3 to 9,
The packaging material for steam release constitutes a lid portion that seals an opening of a container that contains the contents.
A package characterized by that. A package using the packaging material according to any one of claims 3 to 9,
The steam release packaging material forms part of a packaging bag for packaging the contents;
A package characterized by that.

Images