JPH09286471A - Packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an easily-separable tape separate on increase of internal pressure at the time of cooking by heating, and to make removal of internal pressure easy by a method wherein the easily-separable tape interposed in a part to be opened naturally is made to project toward the contents housing part of a bag, and the width of this projection is made smaller than the width of a separated part extending from the internal end of the tape in its breadthwise direction. SOLUTION: At a part A of a packaging bag 1 made up of laminated sheets each composed of a base 51 and a heat-sealing layer 52, a heat-sealing part 2a is formed of a heat-sticking layer of a easily-separable tape 4 and the heat-sealing layer of the bag main body 1. The easily-separable tape 4 is made up by laminating layers 41 and 42 each to be stuck by heating to each of the laminated sheets of the bag main body 1 to an easily-separable sticking layer 43, and a separatred part 43a wherein the layers 42 and 43 are not joined together is formed entirely in the breadthwise direction of the tape 4. The tape 4 is arranged so that it can project by a specified width toward the inside of the bag when interposed in the opening of the bag main body 1, and the width of the separated part 43a is made bigger than the width of projection of the tape 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging bag which does not burst even if there is an increase in internal pressure caused by heating or cooking by a microwave oven or the like.

[0002]

2. Description of the Related Art When heating or cooking contents such as food packed in a bag with a microwave oven, it is necessary to release the internal pressure due to an increase in the internal pressure.

At present, cooking is performed by cutting a part of the bag with hands, scissors, a knife, or the like to create a relief hole for internal pressure, but if this operation is forgotten, heating and cooking will cause the bag to burst. There is a danger of

Therefore, slits are provided in the innermost heat-bonding film of the laminated sheet forming the bag packaging bag,
A bag has been devised in which the adhesive used for laminating the film is applied without being applied to the portion, and the bag is used as an escape port for internal pressure. However, there is a problem with the airtightness inside and outside the bag.

[0005] In addition, a bag having a structure in which a valve is provided in the bag and the valve opens to release the internal pressure when the internal pressure rises has been devised. However, the valve itself must be mounted in a separate process, and the valve itself has a complicated structure. However, there is a problem that the cost increases.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a packaging bag which does not rupture due to an increase in the internal pressure in the bag and the contents thereof are scattered during heating or cooking with a microwave oven. .

[0007]

In order to solve the above-mentioned problems, in the present invention, a heat-sealing layer of the heat-sealing portion can be heat-sealed to the heat-sealing portion of the hermetically sealed packaging bag to be opened naturally. A heat-adhesive layer each having an outermost layer, and an easily peelable tape adjusted to have an adhesive strength such that these layers can be peeled by hand, and heat-sealed by protruding to the contents storage portion side of the bag body, A separation portion is provided in the width direction from the inner end of the easy peeling tape, and the width of the separation portion is set to be larger than the width of the protruding portion of the tape.

The width of the protruding portion of the easily peelable tape may be different on one surface and the other surface of the tape, and the width of the separating portion may be equal to or larger than the width of the smaller protruding portion.

Further, a notch can be provided at the end of the easily peelable tape.

The insertion point of the easily peelable tape is arbitrary.

As described above, since the easily peelable tape is projected to the inside of the contents storage portion, it has sufficient sealing property to withstand the impact when the packaging bag is dropped, and is heated by a microwave oven or the like. When the internal pressure rises abruptly, the easily peelable tape spontaneously opens from the separating portion to allow the internal pressure to escape.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a front view of a packaging bag 1 in which a heat sealing section 2 hermetically stores contents 3. In the part A, the heat sealing portion 2 a is formed by the heat bonding layer (described later) of the easy-peeling tape 4 and the heat sealing layer of the bag body 1.

2 and 3 are longitudinal sectional views of the heat-sealing portion taken along the line II of FIG. As shown, the easy-peeling tape 4 is inserted between the laminated sheets 5 forming the bag body 1 by heat fusion.

As shown in FIGS. 2 to 4, the easily peelable tape 4 is a layer 4 for heat-sealing with the laminated sheet 5 of the bag body 1.
Reference numerals 1 and 42 are laminated by an easily peelable adhesive layer 43. The base materials 411 and 421 of the layers 41 and 42 are preferably made of polyester, nylon (trade name), polypropylene, polyethylene, or the like, and may be a simple substance or a composite thereof. As the heat-bonding layers 412 and 422, a resin that can be heat-sealed to the heat-sealing layer 52 of the bag body 1, for example, polyolefin such as polyethylene or polypropylene,
Ethylene-vinyl acetate copolymer, polyester copolymer, polyamide and the like are used. The base material 411,
As long as 421 itself has a heat fusion property with the laminated sheet 5 of the bag body 1, the thermal adhesive layers 412 and 422 can be omitted. In addition, the base materials 411 and 421 and the thermal bonding layers 412 and 4
A printing layer, a coloring layer, and the like can be provided between the first and second layers.

The easily peelable adhesive layer 43 comprises a resin layer 431 and an adhesive layer 432, and the resin layer 431 has relatively weak adhesive strength, such as vinyl resin, urethane resin, acrylic resin, polyamide resin, silicone resin, etc. Which is formed by a part coat of this resin, and an example of the pattern is shown in FIG.
As shown in (a), (b), and (c), the uncoated portion forms, for example, a dot, line, or lattice pattern.

When the retort sterilization treatment is performed, it is desirable that the adhesive layer 432 is made of an adhesive that causes a small decrease in adhesive strength. As such an adhesive, there is a known two-component curable urethane-based dry laminating adhesive capable of producing a reaction product of a polyol component and an isocyanate component. Of course, other adhesives may be used, but if weak adhesive strength is sufficient, it has easy peel properties such as vinyl chloride, vinyl acetate, copolymer resin, polyethylene resin, polypropylene resin, and linear polyester resin. A resin may be used.

When a film having strong adhesiveness such as polyester copolymer, polyolefin such as polyethylene or polypropylene, or ethylene-vinyl acetate copolymer is used as the base materials 411 and 421, the adhesive layer 43 is used.
2 can be omitted.

As shown in FIG. 6, a resin layer 433 similar to the resin layer 431 can be provided on the opposite side of the adhesive layer 432.

7 and 8 show another example of the easily peelable tape 4. FIG. 7 shows an easily peelable tape 4 formed by coextrusion of a synthetic resin, and at least one of the interlayer adhesive force of the layers 41 and 43, the interlayer adhesive force of the layers 42 and 43, or the cohesive force of the layer 43. Choose the resin so that it is weaker.

FIG. 8 shows the easily peelable tape 4 formed by laminating the layers 41, 42 and 43 alone by a thermal bonding method. As in the case of FIG. 7, the interlayer adhesive force between layers 41 and 43,
The resin is selected so that at least one of the adhesive force between layers 42 and 43 or the cohesive force of layer 43 is weakened.
Also, the layers 41 and 43 or the layers 42 and 43 are laminated by an adhesive method using an adhesive or a co-extrusion method, and then,
The layer 42 or the layer 41 may be laminated by a heat bonding method.

Further, it is also possible to prepare the materials 41, 42 and 43 without inserting the easy peeling tape 4 in advance, and insert and heat bond the materials 41, 42 and 43 at the time of bag making.

Next, as shown in FIG. 2, FIG. 3, FIG. 4, FIG. 6, FIG. 7, and FIG.
a, that is, the portion where the layer 42 and the layer 43 are not joined is formed over the entire length of the tape 4 in the width direction. In order to form the separating portion 43a, as shown in FIGS. 2, 4, 6, and 7, after the entire surface is previously bonded to the layer 42 via the easy peeling adhesive layer 43, only the separating portion 43a is taped. Of the entire length in the width direction of the tape, or a method of not pressing the portion corresponding to the separating portion 43a when forming the tape 4, as shown in FIGS. 3 and 8, only the portion corresponding to the separating portion 43a is easily peeled off. There is a method of not providing (removing) the adhesive layer 43.

As shown in FIGS. 2, 3 and 9, the bag body 1 is composed of a laminated sheet of a base material 51 and a heat sealing layer 52. The base material 51 is obtained by laminating a surface protective layer 511, a gas barrier layer 512, and a reinforcing layer 513, and a printing layer and a coloring layer can be appropriately provided. Further, the present invention is not limited to this depending on the application, and for example, there may be a configuration without the gas barrier layer 512 or a configuration without the reinforcing layer 513. Further, the positions of layers 512 and 513 may be interchanged. As the heat sealing layer 52, a polyolefin,
Although an ethylene-vinyl acetate copolymer or the like is used, the present invention is not limited to this, and the point is that it can be heat-bonded (strongly adhered) to the heat-bonding layers 412 and 422 of the easily peelable tape 4. If the base material 51 has a heat fusion property with the thermal adhesive layers 412 and 422, this layer 52 can be omitted.

When the tape 4 is interposed in the opening of the bag body 1 as described above, as shown in FIGS. 2 and 3,
The tape 4 is arranged so as to protrude by a fixed width inside the bag. At this time, as shown in FIG.
Is set so that a ≧ b> 0. In this way, by projecting the tape 4 into the bag, even if internal pressure due to impact or the like during handling is applied to the tape intervening portion, the pressure is concentrated on the base portion B (FIG. 2) of the protruding portion of the tape 4, Since this portion is strongly bonded to the bag 1, the easily peelable adhesive layer 43 of the tape 4 does not peel off.

Further, as shown in FIG. 3, the width of the protruding portion may be different on one surface and the other surface of the easy peeling tape 4. In the case shown in the drawing, b ₁ <b ₂ , and the relationship with the separation part a is a ≧ a.
It may be b ₁ . Therefore, in some cases, a ≦ b ₂ and a> b
_It may be ₂ . By making the protrusion widths different in this way, the pressure resistance and impact resistance are further improved.

However, when the internal pressure is greatly increased by heating by the microwave oven, the pressure applied to the separating portion 43a increases, the peelable adhesive layer 43 peels from the separating portion 43a, and the layers 41 and 42 are separated. To do. The separating section 43a
The width a of the protrusion is equal to or larger than the width b or b ₁ of the protruding portion and the widths a, b, b ₁ and b ₂ are appropriately selected to facilitate natural opening due to an increase in internal pressure and control the pressure resistance. It can be done easily.

The tape 4 can be interposed not only in the arrangement shown in FIG. 1 but also in various arrangements. In the case of FIG. 1, the tape 4 is fixed over the entire width of the upper end of the bag body. In this case, when the tape 4 without the adhesive layer 43 is used for the separating portion 43a as shown in FIGS. 3 and 8, since the separating portion 43a extends to the side edge portion of the bag body 1, airtightness is maintained. Absent. Therefore, for example, as shown in FIGS. 10 and 11, the side edge portions of the opening are directly heat-sealed together to form the heat-sealing portion 2 (so-called three-way sealing), and the heat-sealing portion is formed. It is preferable to interpose the tape 4 on a portion other than 2. In the figure, reference numeral 2a is a heat-sealing portion between the tape 4 and the sheet 5.

Further, as shown in FIGS. 12 and 13, a heat-sealing portion 2 is formed on the entire circumference of the bag body 1 (so-called four-sided seal), and the tape 4 is interposed immediately below the heat-sealing portion 2 at the upper end. You may let me. In this case, it is necessary to provide the notch 6 or the like at an appropriate place. This is because there is no escape hole for the internal pressure even if the tape 4 separates due to an increase in the internal pressure. Further, in order to take out the contents, it is necessary to separately open the package. The notch 6 may be used for this opening, but the notch 9 for opening may be formed.

As shown in FIGS. 14 and 15, the bag body 1
The upper ends of the sheets may be directly heat-sealed to each other, the tape 4 may be interposed directly below the sheets, and the tape 4 may be extended to both side edges. In this case, it is not necessary to form the notch 6 or the like for the internal pressure escape port. This is because if the tape 4 is separated by increasing the internal pressure, the internal pressure can be released from both ends of the tape 4. However,
The opening for taking out the contents needs to be formed by breaking or cutting the bag.

As shown in FIGS. 16 and 17, the bag body 1
The tape 4 may be provided at a position apart from the upper end of the tape. In the case shown in the drawing, the tape 4 is inserted only in the intermediate portion of the bag body 1 except for the heat-sealing portions 2 as in FIG. Also in this case, it is necessary to provide the notch 6, the cut 7 or the perforation 8 as an escape port for the internal pressure. This perforation 8 can be used as a break line for forming an opening.

If desired, a sachet of seasoning or the like can be stored above the tape 4.

FIG. 18 has almost the same structure as the bag body 1 of FIGS. 16 and 17, but the tape 4 is inserted by extending it to both side edges of the bag 1. In this case, it is not necessary to specially provide an escape port for the internal pressure, but the notch 6 or the perforation 8 as the escape port for the internal pressure may be used together. Of course, these notches 6 and perforations 8 also serve to form an opening.

As described above, in the case shown in FIGS. 14 and 18, the tape 4 of the type having no adhesive layer 43 in the separating portion 43a cannot be used. Therefore, FIG.
As shown in FIG.
a and 4a are formed, and the sheets 5 of the bag body 1 are directly heat-sealed to each other only to form the heat-sealing portion 2b. When the internal pressure increases, it can be released from the portion 4b other than the heat sealing portion 2b (the portion other than the cutout 4a). By appropriately selecting the size of the portion 4b other than the notch so that the internal pressure is gradually released, a steaming effect can be provided when the stored item is, for example, cooked rice. FIG.
Similarly, in the case of 6, by adjusting the notch 6, the notch 7, and the perforation 8 to appropriate pores and adjusting the escape amount of the internal pressure,
A steaming effect is obtained.

As can be understood from FIGS. 10 to 19, the insertion position of the tape 4 can be arbitrarily selected.

Although FIG. 1 and FIGS. 10 to 19 show an example of the flat bag, as another embodiment, a self-standing bag is shown in FIG.
0 is shown. As shown in the figure, the easy peeling tape 4 is inserted in the upper portion of the self-standing bag 1a. The tape 4 projects outside from the opening of the self-standing bag 1a. If the layers 41 and 42 of the protrusion are separated in advance, they can be easily opened by hand. Of course, the same applies to flat bags.

Next, examples and comparative examples will be described.

[0038]

Example 1 The base material 51 of the sheet 5 (see FIG. 2) has a thickness of 1
2μ polyester, heat-sealing layer 52 uses unstretched polypropylene with a thickness of 60μ, size 150mm × 250m
m flat bags were prepared. The heat-adhesive layers 412 and 422 of the tape 4 (see FIG. 4) are 30 μm-thick unstretched polypropylene, the substrates 411 and 421 are 12 μm-thick polyester, the resin layer 431 is an acrylic resin, and the adhesive layer 432 is Length of 15 using a two-component curing type urethane adhesive
Create an easily peelable tape with a width of 0 mm and a width of 20 mm and separate it with a separation width a
Is 5 mm and the protrusion b is 2 mm (see FIG. 2).
A bag having a structure of 8 was prepared. The size of the main room is 130 mm ×
The content was 195 mm, and the content was 30 g of gauze impregnated with 50 g of water.

[0039]

Example 2 Using the same sheet as in Example 1, a flat bag of the same size was prepared. The easy peeling tape was the same as in Example 1, but the acrylic resin layer was two layers (431 and 4) as shown in FIG.
33) Formed, with a size of 130 mm and a width of 20 mm, a bag having the structure of FIG. 16 was prepared, and the same contents were enclosed.

[0040]

Example 3 An easily peelable tape having a base material having a thickness of 20 μm and a heat-sealable polyester copolymer, an outer adhesive layer having a thickness of 30 μm unstretched polypropylene, and an inner release layer having an acrylic resin layer was prepared. A flat bag was prepared in which the same contents were enclosed as in Example 1 except for the above.

[0041]

Example 4 Using the same sheet 5 as in Example 1, a flat bag of the same size was prepared. The easily peelable tape 4 was also made of the same material as in Example 1 and had the same size. However, in order to form the separation portion 43a, as shown in FIG. 8, a portion not coated with the two-component curing type polyurethane adhesive was provided with a thickness of 5 mm.

Using the sheet 5 and the easily peelable tape 4 (see FIG. 3) prepared as described above, b ₁ was set to 2 mm and b ₂ was set to 7 mm, and the same size as in Example 1 was used.
A bag having a structure of 8 was prepared and the same contents were enclosed.

[0043]

Comparative Example Using the same tape, bag and contents as in Example 1,
The separation width a of the tape is 3 mm, and the protrusion width b is 5 mm, that is, a
A flat bag of <b was prepared.

Each bag of the above Examples and Comparative Examples was shaken by hand for 10 seconds to test whether or not there was any omission, but none of the contents was omission.

Next, when heated in a microwave oven of 1200 W for 1 minute, in the example, after 30 seconds from the start of heating, steam was ejected from the steam escape port, and after that, a stable bulging state was maintained and heating was possible without bursting. However, the comparative example bursts on the way.

[0046]

According to the present invention, as described above, the easily peelable tape is interposed at an arbitrary natural opening planned portion, and the tape is projected toward the contents storage portion side of the bag, and the width of the projected portion is set to the width of the tape. Since it is below the separation part provided in the width direction from the inner end, it has excellent pressure resistance, withstands retort sterilization, and at the same time has high impact resistance during distribution and handling, and against increase in internal pressure during heating and cooking by microwave oven etc. On the other hand, since a pressure force acts on the separating portion to easily separate the easily peelable tape, there is an advantage that an escape port for the internal pressure is automatically formed.

Further, the easy peeling tape may be provided with a notch,
By providing a cut or the like on the bag, the size of the escape port for the internal pressure can be appropriately selected, and thereby the contents to be heated can be steamed.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a packaging bag of the present invention.

FIG. 2 is an enlarged vertical sectional view taken along line I-I of the above.

FIG. 3 is an enlarged vertical sectional view showing another example taken along line I-I of FIG.

FIG. 4 is a sectional view of an easily peelable tape.

FIG. 5 is a plan view showing a coating pattern of the resin layer of the above.

FIG. 6 is a cross-sectional view showing another example of the easily peelable tape.

FIG. 7 is a cross-sectional view showing still another example of the easily peelable tape.

FIG. 8 is a cross-sectional view showing still another example of the easily peelable tape.

FIG. 9 is a sectional view showing an example of a laminated sheet forming a bag.

FIG. 10 is a front view showing another example of the packaging bag.

FIG. 11 is a transverse sectional view of the above.

FIG. 12 is a front view showing still another example of the packaging bag.

FIG. 13 is a vertical sectional view of the same.

FIG. 14 is a front view showing still another example of the packaging bag.

FIG. 15 is a transverse sectional view of the above.

FIG. 16 is a front view showing another example of the packaging bag.

FIG. 17 is a vertical sectional view of the above.

FIG. 18 is a front view showing still another example of the packaging bag.

FIG. 19 is a front view showing still another example of the packaging bag.

FIG. 20 is a perspective view showing an example in which the packaging bag is a self-supporting bag.

[Explanation of symbols]

 1 bag body 1a self-supporting bag 2, 2a, 2b heat seal part 3 contents 4 easy peeling tape 4a notch 5 bag laminated sheet 6 notch 7 notch 8 perforation 9 opening notch a easy peeling tape separation width b easy peeling Width of protrusion of tape into bag 41, 42 Layer having heat fusion property 43 Easy peeling adhesive layer 411, 421 Base material 412, 422 Thermal adhesive layer 431 Resin layer 432 Adhesive layer 51 Base material 52 Heat sealing layer 511 Surface Protective layer 512 Gas barrier layer 513 Reinforcing layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Atsunori Sugiyama 3-6-8, Kutaro-cho, Chuo-ku, Osaka Toyo Aluminum Co., Ltd. (72) Taichi Shimizu 3--6-3, Kutaro-cho, Chuo-ku, Osaka No. 8 Toyo Aluminum Co., Ltd.

Claims (4)

[Claims] 1. An easy-peelable tape having a heat-sealing layer of a bag body and a heat-adhesive layer capable of heat-sealing on both outermost layers, and an easy-peelable adhesive layer on an inner layer. A protruding portion that is interposed between the heat-sealing portion and the heat-sealing portion and protrudes toward the contents storage portion of the bag main body, and the easy-peeling adhesive does not exist in advance in the width direction from the inner end of the easy-peeling tape. A packaging bag in which a separated separation portion is provided and the width of the separation portion is equal to or larger than the width of the protruding portion. 2. The width of the protruding portion is made larger on the other surface than on one surface of the easy-peeling tape, and the width of the separating portion is made larger than the smaller width of the protruding portion. Packaging bag. 3. The packaging bag according to claim 1, wherein a cutout is provided at an end of the easily peelable tape. 4. The packaging bag according to claim 1, wherein the heat-sealing portion to be opened is arranged at a position different from the opening portion of the bag body.