JP2002154188A - Food packaging method, laminated film for easily openable food packaging bag, and bag for easily openeable food packaging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a food packaging method which can prevent the intrusion of foreign materials, has easily openable properties, and does not deteriorate the convenience that a packaging bag can be opened/closed repeatedly by a binding tool, etc., a laminated film for an easily openable food packaging bag, and a bag for easily openable food packaging. SOLUTION: The food packaging method in which the laminated film (I) having a surface layer (A) of a propylene resin and a heat seal layer (B) containing a 1-butene 1 copolymer is used, under conditions in which adhesion strength is 7.5-30 N/15 mm, after food is packed in the bag for food packaging having an opening part which is made by melt-adhesion, or after the bag for food packaging having the opening part is made by packing the food while being melt-bonded, easily openable packaging is made by heat sealing under conditions in which the opening part of the bag has strength of 0.1-5 N/15 mm, the laminated film for the easily openable food packaging bag which has the layers (A) and (B), and the bag for easily openable food packaging which is made by melt-bonding the laminated film are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food packaging method which is suitable for packaging food such as bread and confectionery bread, and which is provided with an easy-open seal capable of preventing invasion of foreign substances, and an easy-open food packaging used therefor. The present invention relates to a laminated film for bags and an easily opened food packaging bag made of the laminated film.

[0002]

2. Description of the Related Art Conventionally, food packaging bags such as bread packaging and confectionery bread packaging are sold in a state where the opening is twisted and fixed with a binding device for twisting and fixing, that is, a plastic plate having a slit of about 2 cm square, tape, string, or the like. Have been. Even if the contents are plural or singular, large ones can be opened and closed many times by a resealable tying device, so that they are highly convenient and are often used.

[0003] However, since packaging with such a binding device is simple, there is a gap in the binding portion of the packaging bag, and there is a disadvantage that intrusion of foreign matter cannot be prevented. Therefore, there is a strong demand for a packaging method, a film and a packaging bag which can prevent foreign substances from entering.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent the invasion of foreign matter, and furthermore, it is easy to open.
A food packaging method that does not impair the convenience of being able to open and close the packaging bag many times with a tying tool, a laminated film for an easily opened food packaging bag that can be used for the method, and an easily opened food packaging made of this laminated film It is intended to provide a bag for use.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above situation, and as a result, have found that a surface layer (A) containing a propylene-based resin (a), 1-butene and other α-
A laminated film (I) having a heat seal layer (B) containing a 1-butene copolymer (b1) composed of an olefin and a heat seal layer (B) having the heat seal layer (B) inside. When a bag is formed by performing melt bonding at a temperature higher than or equal to the melting temperature of B), for example, heat sealing or fusing sealing, the bag is firmly bonded, and a food packaging bag having an opening similar to that of the related art is obtained. Fill the bag with food,
At a lower temperature, for example, 100 ° C. or lower, by heat-sealing the opening, for example, the portion between the upper end of the opening of the food packaging bag and the filled food, the sealing strength is improved even if the heat-sealing temperature is slightly varied. Stable easy-opening seal, easy-opening food packaging bag can be easily obtained, and furthermore, by binding the upper part of the bag with a tying tool, it is possible to obtain the same binding packaging as conventional bread packaging. The opened food packaging bag is sealed easily so that the invasion of foreign substances can be prevented. In addition, the bag can be easily opened at the easily opened seal portion, and the bag is not damaged even when opened. Therefore, plastic plates, tapes, strings, etc. It has been found that resealing with a tying member is possible, and the present invention has been completed.

That is, the present invention provides: A surface layer (A) containing a propylene-based resin,
A laminated film (I) having a heat seal layer (B) containing a 1-butene copolymer comprising 1-butene and another α-olefin is used, and the heat seal layer (B) is placed on the inner side. Adhesive strength is 7.5 to 30 N / 15
After the food is filled into a food packaging bag having an opening formed by melt-bonding under the condition of 0.1 mm, the heat sealing strength of the opening of the food packaging bag is 0.1 to 5 N / 15 mm.
1. A food packaging method, characterized in that it is heat-sealed under the following conditions to form an easily openable package. A surface layer (A) containing a propylene-based resin,
A laminated film (I) having a heat seal layer (B) containing a 1-butene copolymer comprising 1-butene and another α-olefin is used, and the heat seal layer (B) is placed on the inner side. Adhesive strength is 7.5 to 30 N / 15
Including food while melting and bonding under the condition of mm
After forming a food packaging bag having an opening, the opening of the food packaging bag has a heat seal strength of 0.1 to 5 N /.
2. A food packaging method, characterized in that the package is heat-sealed under conditions of 15 mm to form an easily openable package. The 1-butene copolymer in the heat seal layer (B) contains 1-butene and propylene as essential components.
3. The food packaging method according to the above 1 or 2, which is a butene-based copolymer (b1); 1-butene copolymer (b1) in which heat seal layer (B) contains 1-butene and propylene as essential components
And a copolymer (b2) containing propylene and ethylene as essential components, the weight ratio (b1) / (b2) being 2
A resin layer containing 5/75 to 75/25 in a proportion of 1-butene-derived component in the 1-butene-based copolymer (b1) is 50 to 99 mol%. 5. The food packaging method according to any one of the above 1 to 4, wherein the food packaging method according to the above 1 or 2 is heat-sealed at a temperature of 6.65 to 95 ° C. for 0.1 to 2 seconds. 7. The food packaging method according to any one of 1 to 5 above, wherein the thickness of the laminated film (I) is 20 to 50 μm, and the thickness of the heat seal layer (B) is 1 to 8 μm. . The laminated film (I) comprises a surface layer (A), an intermediate layer (C) containing a propylene-based resin, and a heat-sealing layer (B), each of (A) / (C) / (B). 7. The food packaging method according to any one of the above 1 to 6, which is a three-layer film laminated in order. The laminated film (I) has a surface layer (A1) containing 75% by weight or more of a propylene-based copolymer containing propylene and ethylene as essential components, and an intermediate layer containing 70% by weight or more of a propylene homopolymer. Layer (C1), 1
A heat seal layer (B1) containing 25 to 75% by weight of a 1-butene copolymer (b1) containing butene and propylene as essential components, (A1) / (C1) /
A three-layer film (I-1) laminated in the order of (B1),
Alternatively, a surface layer (A2) containing 90% by weight or more of a propylene homopolymer, and 90% by weight or more of a propylene homopolymer and / or a propylene-based copolymer containing propylene and ethylene as essential components. The intermediate layer (C2) and the heat seal layer (B1)
2) The food packaging method according to any one of 1 to 6, which is a three-layer film (I-2) laminated in the order of / (C2) / (B1),

[0007] 9. It is necessary to have a surface layer (A) containing a propylene-based resin and a heat seal layer (B) containing a 1-butene-based copolymer composed of 1-butene and another α-olefin. 9. A laminated film for easily opened food packaging bags, The 1-butene copolymer in the heat seal layer (B) contains 1-butene and propylene as essential components.
10. The laminated film for an easily-openable food packaging bag according to 9 above, which is a butene-based copolymer (b1); The heat seal layer (B) is a 1-butene-based copolymer (b) containing 1-butene and propylene as essential components.
1) and a copolymer (b2) comprising propylene and ethylene as essential components, in a weight ratio of (b1) / (b
2) is a resin layer containing 25/75 to 75/25 at a ratio of 1 / butene-based copolymer (b1)
11. The laminated film for an easily-openable food packaging bag according to the item 9, wherein the content of the 1-butene-derived component in the composition is 50 to 99 mol%. A laminated film having a thickness of 20 to 50 μm, and a thickness of the heat sealing layer (B) of 1 to 8 μm;
12. The laminated film for an easily-openable food packaging bag according to the above 9, 10 or 11, A surface layer (A), an intermediate layer (C) containing a propylene-based resin, and a heat seal layer (B)
13. The laminated film for an easily-openable food packaging bag according to any one of the items 9 to 12, which is a three-layer film laminated in the order of / (C) / (B). A surface layer (A1) containing 75% by weight or more of a propylene-based copolymer containing propylene and ethylene as essential components; an intermediate layer (C1) containing 70% by weight or more of a propylene homopolymer; A 1-butene-based copolymer containing butene and propylene as essential components in an amount of 25 to 7;
A heat seal layer (B1) containing 5% by weight,
A three-layer film (I-1) laminated in the order of (A1) / (C1) / (B1), or a surface layer (A2) containing 90% by weight or more of a propylene homopolymer, and propylene alone 90% by weight of a polymer and / or a propylene-based copolymer containing propylene and ethylene as essential components
A three-layer film (I-2) obtained by laminating the intermediate layer (C2) containing the above and the heat seal layer (B1) in the order of (A2) / (C2) / (B1). The above 9-1
2. The laminated film for an easily-opened food packaging bag according to any one of 2.

[0008] 15. It consists of the laminated film for easy-open food packaging bags as described in any one of 9 to 14, and has an adhesive strength of 7.5 to 30 with the heat seal layer (B) inside.
13. An easily-openable food packaging bag having an opening, characterized by being melt-bonded under conditions of N / 15 mm to form a bag. Heat sealing strength of the opening is 0.1-5N / 15
16. The easily-openable food packaging bag according to the above item 15, which is a bag that can be heat-sealed under the condition of 1 mm. 17. A bag for easily opening food packaging according to claim 15 or 16, wherein the bag is a bag made so that a gusset is placed at the bottom.
Is provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The laminated film (I) used in the present invention comprises a surface layer (A) containing a propylene-based resin and a 1-butene-based film comprising 1-butene and another α-olefin. What is necessary is just to have the heat seal layer (B) containing a polymer.

The surface layer (A) may be, for example, a homopolymer of propylene; a random copolymer of propylene and ethylene, a block copolymer of propylene and ethylene, and an α-olefin other than propylene and ethylene. A propylene-based copolymer such as a propylene-based copolymer; and preferably 75% by weight or more of a propylene-based resin such as ethylene-butene copolymer. A resin layer formed by mixing other thermoplastic resins such as a polymer and a linear low-density polyethylene or various additives is used.

The heat seal layer (B) may be a resin layer containing a 1-butene copolymer composed of 1-butene and another α-olefin, but the heat seal layer (B) may be a 1-butene copolymer. It is preferable to use a 1-butene-based copolymer (b1) containing 1-butene and propylene as essential components as a coalescence, and it is particularly easy to adjust the heat sealing temperature and strength at the time of easy-open sealing at a low temperature. Since the heat seal temperature range is wide and a suitable heat seal strength is easily obtained as an easy-open seal, a copolymer comprising the 1-butene copolymer (b1), propylene and ethylene as essential components ( b2) and its weight ratio (b1) /
(B2) is preferably a resin layer used in combination at a ratio of 25/75 to 75/25, and the 1-butene-based copolymer (b1) used here is a 1-butene-derived component. Is particularly preferably 50 to 99 mol%.

The heat seal layer (B) is made of JI
The fact that the heat seal start temperature measured in accordance with the heat seal start temperature test defined in SK-1713 is lower than the heat seal start temperature of the surface layer (A) indicates that the production of the food packaging bag and the easy-open seal It is preferable because it is easy. For this reason, as the laminated film (I) according to the present invention, it is preferable that the heat sealing start temperature difference between the surface layer (A) and the heat sealing layer (B) is 30 ° C. or more,
Above all, it is particularly preferable to set the temperature to 35 to 90 ° C.

The laminated film (I) according to the present invention may be a two-layer film obtained by laminating a surface layer (A) and a heat seal layer (B) in the order of (A) / (B). Considering the rigidity and cold resistance of the film, the surface layer (A), the intermediate layer (C) containing propylene-based resin, and the heat seal layer (B) are (A) / (C) / (B). May be used as a three-layer film. In this case, as the intermediate layer (C), for example, a homopolymer of propylene, a random copolymer of propylene and ethylene, a block copolymer of propylene and ethylene, and an α-olefin other than propylene and ethylene It contains at least one propylene resin as a main component, preferably 70% by weight or more, such as a copolymer of ethylene and the like. If necessary, ethylene-1-butene copolymer, linear low density Examples of the resin layer include a mixture of other thermoplastic resin such as polyethylene or the like and a collected product generated during the production of the present laminated film.
Further, the intermediate layer (C) may be a resin layer having the same composition as the surface layer (A).

Further, the intermediate layer (C) can be divided into two or more layers, and there is no problem even if the whole layer structure is three or more layers.

The thickness of the laminated film (I) according to the present invention is usually from 20 to 50 μm, preferably from 25 to 40 μm.
μm is preferred. The thickness of the heat seal layer (B) is usually 0.1 to 10 μm, and especially 1 to 8 μm.
m is preferred.

The laminated film (I) according to the present invention comprises (A)
In the case of a three-layer film laminated in the order of / (C) / (B), the thickness ratio to the total thickness of the surface layer (A) and the intermediate layer (C) varies depending on the resin composition of each layer, but is not particularly limited. The surface layer (A) is usually 10 to 50%, preferably 1 to 50%.
5 to 45%, the intermediate layer (C) is usually 30 to 80%,
Preferably it is 40 to 70%.

Specific examples of the laminated film (I) according to the present invention include, for example, a surface layer (A) containing 75% by weight or more of a propylene-based copolymer containing propylene and ethylene as essential components.
1), an intermediate layer (C1) containing 70% by weight or more of a propylene homopolymer, and 25-75% by weight of a 1-butene-based copolymer containing 1-butene and propylene as essential components. And the heat seal layer (B1)
1) / (C1) / (B1), in the order of 3: 6: 1, with a thickness of 25 μm
Alternatively, a three-layer film (I-1) having a thickness of 30 μm and containing a gusset at the bottom (hereinafter referred to as a bottom gusset bag), and a surface layer (A2) containing 90% by weight or more of a propylene homopolymer. ) And an intermediate layer (C) containing 90% by weight or more of a propylene homopolymer and / or a propylene copolymer containing propylene and ethylene as essential components.
2) and the heat sealing layer (B1)
In the order of (C2) / (B1), the ratio of the average thickness is 2:
A three-layer film (I-2) having a thickness of 25 μm or 30 μm, which is laminated so as to have a thickness of 7: 1 and suitable for pillow packaging bags, propylene homopolymer and / or propylene and ethylene as essential components Propylene-based copolymer
A surface layer (A3) containing 0% by weight or more, and an intermediate layer (C3) containing a total of 70% by weight or more of a linear low-density polyethylene and a propylene-based copolymer containing propylene and ethylene as essential components. ) And the heat seal layer (B
1) and (A3) / (C3) / (B1) in this order so that the ratio of their average thickness is 3: 6: 1.
And a three-layer film (I-3) having a thickness of 25 μm or 30 μm and suitable for a bottom gusset bag.

The laminated film (I) according to the present invention may be used as it is, but the surface layer (A) may be subjected to a corona discharge treatment in order to improve the product appeal by printing. Also,
In each layer of the laminated film (I), if necessary, additives such as an antioxidant, a slip agent, an antiblocking agent, an antifogging agent, a coloring agent, and silica are appropriately added within the scope of the present invention. sell.

The method for producing the laminated film (I) according to the present invention is not particularly limited, but is preferably a coextrusion molding method or an extrusion lamination method, particularly preferably a coextrusion molding method.

The bag for easy-open food packaging and the food packaging method of the present invention using the laminated film (I) are described below in (1).
The following describes the bread packaging method using the three-layer film (I-1) or (I-3) and the (2) various bread stacking and packaging method using the three-layer film (I-2). The laminated film (I) may be prepared in advance by a third party in large quantities and may be used as needed.

(1) Bread packaging method For the bread packaging method, it is usually preferable to use the three-layer film (I-1) or (I-3). After printing, the three-layer film (I-1) or (I-3) is formed by a bag making machine such as HK-40 manufactured by Totani Giken Kogyo Co., Ltd. so that the heat seal layer is on the inside of the bag. Process into a bottom gusset bag. At this time, the fusing seal strength between the side portion of the bottom gusset bag and the bottom gusset portion (folded portion at the bottom) is 7.5 to 30 N / 15 mm, preferably 12 to 30 N /.
Adjust the fusing seal temperature and the bag making speed to be 15 mm. Next, the obtained bottom gusset bag is supplied to an automatic bread filling machine, and after filling the bread, it is easily openable and has a heat seal strength of 0.1 to 5 N / 15 mm, preferably 0.1 to 5 N / 15 mm.
Heat-sealed under the condition of 2 to 3.5 N / 15 mm to form an easily-openable bread packaging bag, and if necessary, an easily-openable seal portion at the top of the bag, preferably at the top of the bread, or above or below it. Around the area is tied using a tying tool such as a plastic plate, tape or string. In the present invention, a bag for easy-opening food packaging may be prepared and the food may be packaged immediately, or a bag for easy-opening food packaging prepared in advance by a third party may be prepared. This may be used to package food.

(2) Packaging method for a plurality of confectionery breads It is usually preferable to use a three-layer film (I-2) for collecting and packaging various kinds of breads such as butter rolls.
After printing, the three-layer film (I-2) is a horizontal pillow type automatic packaging machine, for example, FW-3400α manufactured by Fujiki Kai Co., Ltd.
It is supplied in a roll form to a V-shape or the like so that the heat seal layer is inside the bag. In horizontal pillow type automatic packaging machine,
The pan is enclosed while a bag is formed by heat-sealing the heat-sealed surfaces of the films. At this time, the sealing strength between the bottom and the back of the pillow packaging bag by the packaging machine is 7.5 to 30 N / 15 mm, preferably 8 to 20 N /.
Heat seal temperature and packaging speed are adjusted to be 15 mm. Next, it is easy to open and has a heat seal strength of 0.1.
1 to 5 N / 15 mm, preferably 0.2 to 3.5 N / 1
Heat-sealing under the condition of 5 mm to form an easy-open pillow packaging bag, and if necessary, at the top of the bag, preferably at the top of the pan, a plastic plate or tape near the easy-open seal portion or above or below it. And a binding tool such as a string.

The easily-openable seal referred to in the present invention means that a 15 mm-wide test piece cut out from a heat-sealed portion of a bag is measured by a tensile tester [Tensilon manufactured by A & D Co., Ltd.]. The heat seal strength when measured at a temperature of 23 ° C. and a tensile speed of 300 mm / min is 0.1 to 5 N / 15 mm, and 80% or more of the test pieces are from the sealing surface without breaking the film. It refers to the heat seal that peels off.

In the food packaging method of (1) or (2) above, the heat seal after filling the bread is easily opened and has a heat seal strength of 0.1 to 5 N / 15 mm. The time varies depending on the seal pattern and the seal pressure, and is not particularly limited.
0.1 to 2 seconds at 5 to 95 ° C, particularly preferably 70 to 9
0.3-1.5 seconds at 0 ° C.

[0025]

The present invention will be described more specifically below with reference to examples and comparative examples. The parts and percentages in the examples are
All are by weight unless otherwise noted.

Example 1 As the surface layer (A), a propylene-ethylene copolymer [ethylene content: 5.8%, density: 0.90 g / cm ³ , melt index (hereinafter referred to as MI): 6 g / 10
Min) and 90 parts of a crystalline ethylene-1-butene copolymer (density: 0.88 g / cm ³ , MI: 4 g / 10 min) 1
0 parts, and as a middle layer (C),
Propylene homopolymer (density: 0.90 g / cm ³ , M
I: 9 g / 10 minutes) and further a heat seal layer (B)
As a propylene-1-butene copolymer (density: 0.1
A mixture consisting of 50 parts of 90 g / cm ³ , MI: 4 g / 10 minutes) and 50 parts of the propylene-ethylene copolymer used in the surface layer (A) was supplied to three extruders, respectively.
A three-layer film having a thickness of 30 μm was formed by co-extrusion so that the ratio of the average thickness of the surface layer (A), the intermediate layer (C) and the heat seal layer (B) was 3: 6: 1.

Next, a corona discharge treatment is performed so that the surface energy of the surface layer (A) becomes 330 μN / cm.
A polypropylene resin laminated film for a bottom gusset bag was produced. After the obtained laminated film was aged at 35 ° C. for 48 hours, the film was folded in half with the heat sealing layer (B) inside, and a gusset was placed at the bottom. At the sealing temperature (bag making temperature) shown in Table 1, Fusing seal and bag making (bag making machine: HK-40 manufactured by Totani Giken Kogyo Co., Ltd., bag making speed: 1)
20 pieces / min) and bottom gusset bag [length: 345 mm (side: 245 mm, gusset: 60 mm), width 23
5 mm], and the obtained bottom gusset bag is filled with bread. Then, a space between the upper end of the opening and the bread (a portion 50 mm below the upper end of the opening) is parallel to the opening with a heat sealer [Tester Sangyo ( Co., Ltd .: pressure: 0.2 MPa, time: 1 second, seal temperature: the upper seal bar temperature
At the temperature shown in the table, the lower seal bar was fixed at 50 ° C., and the shape of the seal bar: 300 mm × 10 mm flat surface] was heat-sealed to obtain an easily-openable bread loaf bottom gusset bag.
Using this easy-open bread gusset bag for bread packaging, the fusing seal strength and the heat seal strength were measured as described below, and the presence or absence of film breakage during the heat seal strength measurement was observed. Table 1 shows the results.

* Fusing seal strength: From the center of the gussets on both sides of the five obtained bottom gusset bags and the center of both sides on the upper part of the gussets, one test piece with a width of 15 mm each ( (2 pieces in one bag) Cut out 10 pieces each in total, 23 ° C, tensile speed 300m
The maximum load at the time of peeling was measured with a Tensilon tensile tester (manufactured by A & D Co., Ltd.) under the condition of m / min, and it was defined as the fusing seal strength.

* Heat-sealing strength: From the heat-sealed portions of the five bottom gusset bags obtained, two test pieces each having a width of 15 mm (the heat-sealed portion was divided into two equal parts, and one from each of the central portions). , A total of 10 pieces were cut out, and the maximum load at the time of peeling was measured with a Tensilon tensile tester (manufactured by A & D Co., Ltd.) under the conditions of 23 ° C. and a tensile speed of 300 mm / min. .

Comparative Example 1 A propylene-ethylene copolymer (ethylene content: 3.7%, density: 0.90 g / c) was used as the heat seal layer (B).
m ³ , MI: 8 g / 10 min), except that the ratio of the average thickness of the surface layer (A), the intermediate layer (C), and the heat seal layer (B) was changed to 3: 4: 3. A laminated film was manufactured in exactly the same manner as in Example 1, and the sealing strength was measured in the same manner to observe whether or not the film was broken. Table 1 shows the results.

[0031]

[Table 1]

As can be seen from the results in Table 1, the bottom gusset bag obtained by using the laminated film (I) of the present invention has the same side seal strength and bottom gusset as the bag obtained by the conventional laminated film. When the opening portion of the bag is heat-sealed at 80 ° C., the film can be peeled off from the sealing surface without breakage of the film.

Example 2 As the surface layer (A), a propylene homopolymer (density:
0.90 g / cm ³ , MI: 9 g / 10 min)
As the intermediate layer (C), 80 parts of the same propylene homopolymer as the surface layer (A) and a propylene-ethylene copolymer (ethylene content: 3.7%, density: 0.90 g / cm ³ , M
I: 8 g / 10 minutes) and 20 parts of
Using exactly the same mixture as in Example 1 as the heat seal layer (B), the mixture was supplied to three extruders, and the weight of the surface layer (A), the intermediate layer (C), and the heat seal layer (B). A three-layer film having a thickness of 30 μm was formed by co-extrusion at a ratio of 2: 7: 1.

Next, a corona discharge treatment is performed so that the surface energy of the surface layer (A) becomes 390 μN / cm.
A polypropylene resin laminated film for a horizontal pillow bag was manufactured. After aging the obtained laminated film at 35 ° C. for 48 hours, a horizontal pillow packaging machine [FW-3410 manufactured by Fujiki Kai Co., Ltd.] was placed so that the heat seal layer (B) was on the inside.
αV), the bottom upper seal bar temperature is 135 ° C,
A pillow packaging bag having an opening at the top [length: 410 mm, width 21]
5 mm], and after the butter roll pan is included, between the upper end of the opening and the pan (8 mm below the upper end of the opening).
0 mm portion) in parallel with the opening, heat sealer [manufactured by Tester Sangyo Co., Ltd .: pressure: 0.2 MPa, time: 1 second, sealing temperature: the temperature of the upper seal bar at the temperature shown in Table 1, and the lower seal The bar was fixed at 50 ° C., and the shape of a seal bar: 300 mm × 10 mm flat surface] was heat-sealed to obtain an easily-openable bread packaging bag. Using this easy-opening bread packaging bag, the sealing strength of the pillow packaging bag was measured as follows, and further, the heat sealing strength of the heat sealing portion between the upper end of the opening and the pan and the presence or absence of film breakage during the measurement Was observed. Table 2 shows the results.

* Seal strength of the pillow packaging bag: 15 points from the bottom and back affixed part of the obtained five pillow packaging bags.
A total of 10 test pieces each having a width of 2 mm (the bottom part and the back part were each divided into two equal parts, and one piece each from the center part) were cut out at 23 ° C. and a tensile speed of 300 mm /
Minutes under the conditions of Tensilon tensile tester [A &
The maximum load at the time of peeling was measured as the seal strength of the pillow packaging bag.

* Heat seal strength: From the heat seal portions of the five obtained pillow packaging bags, two test pieces each having a width of 15 mm (the heat seal portion was divided into two equal parts, and one from the center portion). , A total of 10 pieces were cut out, and the maximum load at the time of peeling was measured with a Tensilon tensile tester (manufactured by A & D Co., Ltd.) under the conditions of 23 ° C. and a tensile speed of 300 mm / min. .

Comparative Example 2 A propylene-ethylene copolymer resin (ethylene content: 5.8%, density: 0.90 g) was used as the heat seal layer (B).
/ Cm ³ , MI: 6 g / 10 min), a laminated film was produced in exactly the same manner as in Example 2, and the seal strength was measured in the same manner. Observed. Table 2 shows the results.

[0038]

[Table 2]

As can be seen from the results in Table 2, the pillow wrapping bag obtained by using the laminated film (I) of the present invention has the same bottom seal strength and back seal as the bag obtained by the conventional laminated film. Strength is obtained and the opening of the bag is 80
When heat sealed at ℃, the film can be easily opened without peeling from the sealing surface without breaking the film.

[0040]

According to the food packaging method of the present invention, the heat sealing resin layer of a laminated film having a heat sealing layer containing a 1-butene copolymer is heated to a temperature above the melting point of the heat sealing resin layer. When heat-sealing or fusing-sealing, it adheres firmly, and the same food packaging bag as before can be obtained. In addition, the obtained bag is filled with food, and the opening is heated at a lower temperature, for example, 100 ° C or lower. By sealing, even if the heat sealing temperature varies to some extent, an easily openable seal having a stable seal strength can be obtained, and an easily openable packaging bag in which food is easily sealed can be obtained. The obtained easily-opened food packaging bag is provided with an easily-openable seal, so that invasion of foreign substances can be prevented.Moreover, since the easily-openable seal portion can be easily opened and the bag is not damaged even when opened, a plastic plate, It can be resealed with a tying tool such as a tape or a string, and by further tying the upper part of the bag with the tying tool, it is possible to obtain a binding package similar to a conventional bread package.

The food packaging method, the easily opened food packaging bag film and the easily opened food packaging bag of the present invention are of great practical value for twisted bag packaging of bread, snacks, fruits and vegetables, and horizontal pillow packaging. .

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Haruki Noda 3-10-1 Iwamotocho, Chiyoda-ku, Tokyo Yamazaki Bread Co., Ltd. (72) Inventor Yasufumi Watanabe 4-4-2 Narashinodai, Funabashi-shi, Chiba 505 (72) Inventor Takashi Sumiki 3-4-16 Sakuradai, Ichihara City, Chiba Prefecture F-term (reference) AK64A AK64B AK65B AK67B AL01B AL05B BA02 BA03 BA07 BA10A BA10B GB16 GB23 JL11 JL12 JL12B YY00

Claims (17)

[Claims] 1. A surface layer (A) containing a propylene-based resin and a heat-sealing layer (B) containing a 1-butene-based copolymer composed of 1-butene and another α-olefin. And the adhesive strength is 7.5 to 3 with the heat seal layer (B) inside.
After filling food into a food packaging bag having an opening formed by melting and bonding under the condition of 0 N / 15 mm, the opening of the food packaging bag has a heat seal strength of 0.1 to 5 N.
A food packaging method, characterized in that heat sealing is performed under the condition of / 15 mm to obtain easily openable packaging. 2. A surface layer (A) containing a propylene-based resin and a heat-sealing layer (B) containing a 1-butene-based copolymer of 1-butene and another α-olefin. And the adhesive strength is 7.5 to 3 with the heat seal layer (B) inside.
After the food is included while being melt-bonded under the condition of 0 N / 15 mm to form a food inclusion packaging bag having an opening,
The opening of the food-containing packaging bag has a heat seal strength of 0.
A food packaging method, wherein heat-sealing is performed under conditions of 1 to 5 N / 15 mm to form an easily openable package. 3. The 1-butene copolymer (b1) comprising 1-butene and propylene as essential components in the heat seal layer (B).
Or the food packaging method according to 2. 4. The heat seal layer (B) comprises a 1-butene copolymer (b1) comprising 1-butene and propylene as essential components and a copolymer (b2) comprising propylene and ethylene as essential components. ) And its weight ratio (b1) /
A resin layer containing (b2) in a ratio of 25/75 to 75/25, and a 1-butene-based copolymer (b
The content of the 1-butene-derived component in 1) is 50 to 9
3. The food packaging method according to claim 1, wherein the amount is 9 mol%. 5. The food packaging method according to claim 1, wherein heat sealing is performed at a temperature of 65 to 95 ° C. for 0.1 to 2 seconds. 6. The laminated film (I) has a thickness of 20 to 50.
μm and the thickness of the heat seal layer (B) is 1 to
The food packaging method according to any one of claims 1 to 5, wherein the thickness is 8 µm. 7. The laminated film (I) comprises a surface layer (A)
And an intermediate layer (C) containing a propylene-based resin;
The food packaging method according to any one of claims 1 to 6, which is a three-layer film obtained by laminating a heat seal layer (B) in the order of (A) / (C) / (B). 8. The laminated film (I) comprises a propylene-based copolymer containing propylene and ethylene as essential components.
A surface layer (A1) containing 5% by weight or more and an intermediate layer (C) containing 70% by weight or more of a propylene homopolymer.
1) and a heat seal layer (B1) containing 25 to 75% by weight of a 1-butene-based copolymer (b1) containing 1-butene and propylene as essential components, (A1) /
A three-layer film (I-1) laminated in the order of (C1) / (B1), or a surface layer (A2) containing 90% by weight or more of a propylene homopolymer, and a propylene homopolymer and / or Alternatively, an intermediate layer (C2) containing 90% by weight or more of a propylene-based copolymer containing propylene and ethylene as essential components, and the heat seal layer (B1)
The food packaging method according to any one of claims 1 to 6, wherein a three-layer film (I-2) obtained by laminating (A2) / (C2) / (B1) in this order. 9. A surface layer (A) containing a propylene-based resin and a heat seal layer (B) containing a 1-butene-based copolymer composed of 1-butene and another α-olefin. And a laminated film for an easily-openable food packaging bag. 10. The 1-butene copolymer (b1) comprising 1-butene and propylene as essential components in the heat seal layer (B). Laminated film for easily opened food packaging bags. 11. A heat seal layer (B) comprising a 1-butene copolymer (b1) comprising 1-butene and propylene as essential components, and a copolymer comprising propylene and ethylene as essential components ( b2) and its weight ratio (b
1) / (b2) is a resin layer containing at a ratio of 25/75 to 75/25, and the content of the 1-butene-derived component in the 1-butene-based copolymer (b1) is 5
The laminated film for an easily-openable food packaging bag according to claim 9, wherein the content is 0 to 99 mol%. 12. A laminated film having a thickness of 20 to 50 μm, and a heat seal layer (B) having a thickness of 1 to 8 μm.
The laminated film for an easily-openable food packaging bag according to claim 9, 10 or 11, wherein m is m. 13. A surface layer (A), an intermediate layer (C) containing a propylene-based resin, and a heat seal layer (B) in the order of (A) / (C) / (B). The laminated film for an easily-openable food packaging bag according to any one of claims 9 to 12, which is a laminated three-layer film. 14. A surface layer (A1) containing 75% by weight or more of a propylene-based copolymer containing propylene and ethylene as essential components, and an intermediate layer (70% by weight or more of a propylene homopolymer). C1) and a heat seal layer (B) containing 25 to 75% by weight of a 1-butene copolymer containing 1-butene and propylene as essential components.
1) and (A1) / (C1) / (B1) in this order, or a three-layer film (I-1) or a surface layer (A2) containing 90% by weight or more of a propylene homopolymer. )
And an intermediate layer (C2) containing 90% by weight or more of a propylene homopolymer and / or a propylene-based copolymer containing propylene and ethylene as essential components, and the heat seal layer (B1). ) / (C2) / (B
The laminated film for an easily opened food packaging bag according to any one of claims 9 to 12, which is a three-layer film (I-2) laminated in the order of 1). 15. A laminated film for an easily-openable food packaging bag according to any one of claims 9 to 14, having an adhesive strength of 7.5 to 30 N with the heat seal layer (B) inside.
An easily openable food packaging bag having an opening, characterized in that the bag is made by melt-bonding under conditions of / 15 mm. 16. The heat sealing strength of the opening is 0.1 to 0.1.
The bag for easily opening food packaging according to claim 15, which is a bag that can be heat-sealed under a condition of 5N / 15mm. 17. The bag for easily opening food packaging according to claim 15, wherein the bag is formed so that a gusset is inserted into a bottom portion.