KR20010030428A - Packing material and container - Google Patents

Abstract

PURPOSE: A package material and a container is provided which has a few curl, no stringiness when torn and easy tearability in a field of the container torn by peeling the heat sealed part of a sealed container. CONSTITUTION: A package material comprises at least a base material(3) and a heat sealing layer(2). In this case, the sealing layer(2) has a laminated structure obtained by providing a resin layer(2B) made of an ethylene-unsaturated carboxylate copolymer from the side near the base material(3), and a resin layer(2A) containing a low density polyethylene of 50 to 75 weight percent. and a polybutene-1 of 45 to 25 weight percent. provided in this order in such a manner that the layers(2A,2B) are laminated to one another by a co-extrusion method. When the packaging material is heat sealed as the cover material of a paper cup container coated on its innermost layer with the polyethylene having a melting point of 105 to 115 deg.C, the layer(2A) is cohesively broken when torn.

Description

PACKING MATERIAL AND CONTAINER {PACKING MATERIAL AND CONTAINER}

The present invention relates to packaging materials and containers.

The easily openable packaging material having easy peelability is largely classified into an interface peeling type, an interlayer peeling type, and a cohesive peeling type by the difference in the peeling mechanism. Among these, the material of a cohesive peeling type expresses easy peeling by generating internal cohesive failure at the time of peeling layer resin opening. As a material of agglomeration peeling type, the EVA type material which mixed the wax and the caking additive, and incompatible polymer alloys, such as a polyolefin / polystyrene type and polyethylene / polypropylene type, are known, and peel strength is known. It has the characteristics of being excellent in sealing temperature stability, the sealing property of contaminants, and the resistance to contents. Here, "excellent contaminant sealing property" means good heat sealing performance even when a contaminant having a relatively large particle size is mixed in the heat sealing material.

However, the conventional easy opening material belonging to the cohesive failure type has a problem that it is easy to produce what is called a "stickiness phenomenon" in which the release layer resin remains in a fibrous form on the sealing release surface at the time of opening. In addition, since it is difficult to control the peel strength, when the polyethylene coated paper is used as an adherend, there is also a problem in that a so-called "paper peeling phenomenon" is easily generated, because the peel strength is too strong and the paper of the adherend is destroyed.

In addition, when a conventional easy-opening material is laminated on a substrate such as paper, film or metal foil by an extrusion lamination method or the like, the obtained easy-opening packaging material tends to generate curl, so that it is heat sealed to the container as a lid member. There are also problems that often cause problems in supply and handling.

SUMMARY OF THE INVENTION An object of the present invention is to provide a packaging material and a container in which the curling is small in the field of a container for peeling and opening the heat seal of the sealed container, which shows ease of opening without stickiness upon opening.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing an example of the layer structure of the packaging material of the present invention.

2 is a schematic cross-sectional view showing another example of the layer structure of the packaging material of the present invention.

Fig. 3 is a conceptual diagram illustrating a state when the packaging material of the present invention is peeled from the adherend, (a) is a state in which it is heat-sealed, and (b) is a state in which the heat-sealing part is peeled.

Figure 4 shows an embodiment of a container using the packaging material of the present invention as a lid member, (a) is a perspective view of the container, (b) is a sectional view of the part XX, (c) is a partial sectional view of the seal, (d ) Is a partial cross-sectional view of the peeling part when the cover member is peeled off.

<Explanation of symbols for main parts of drawing>

1: packing material

2: heat seal layer

3: description

4: adhesive layer

10: adherend

11: adherend heat seal layer

13: heat seal

14: peeling part

20 container

21: cover

22: container body

23: flange

30: hotplate

The easy-opening packaging material according to the present invention comprises at least a base material and a heat sealing layer provided on one surface side of the base material, and the heat sealing layer is made of an ethylenically unsaturated carboxylic acid copolymer from a side close to the base material. (B) and the resin layer (A) which contains 55-75 weight part of low-density polyethylene and 45-25 weight part of polybutene-1 in this order, and has the laminated structure provided, and the said resin layer (A ) And the resin layer (B) are laminated with each other by a coextrusion method.

In addition, the container which is easy to open according to the present invention is heat sealed as a lid member of a paper cup container in which a packaging material is coated with polyethylene having a melting point of 105 to 115 ° C on the innermost layer, and at the time of opening, the resin layer (A) is cohesive and broken. Characterized in that.

It is preferable that the thickness of the said resin layer (A) is the range of 5-15 micrometers, and the thickness of the said resin layer (B) is more than the thickness of the resin layer (A).

The low density polyethylene is a high pressure low density polyethylene having a melting point of 110 ° C. or lower, the polybutene-1 is a homopolymer having a melting point of 120 ° C. or higher, and the melting point of the ethylenically unsaturated carboxylic acid copolymer is lower than that of the low density polyethylene. It is preferable.

Moreover, it is preferable that the said heat sealing layer is laminated | stacked on the said base material by the coextrusion laminating method.

1 is a schematic cross-sectional view showing an example of the layer structure of the packaging material of the present invention. 2 is a schematic cross-sectional view showing another example of the layer structure of the packaging material of the present invention. Fig. 3 is a conceptual diagram illustrating a state when the packaging material of the present invention is peeled from the adherend, (a) is a state of heat sealing, and (b) is a state of peeling the heat sealing portion. Figure 4 shows an embodiment of a container using the packaging material of the present invention as a lid member, (a) is a perspective view of the container, (b) is a sectional view of the part XX, (c) is a partial sectional view of the seal, (d) Is a partial cross-sectional view of the peeling part when the lid member is peeled off.

As shown in Fig. 1 or 2, the packaging material 1 of the present invention comprises at least a base material layer 3 and a heat seal layer 2, wherein the heat seal layers 2 are laminated with different resins. It consists of at least 2 layer 2A, 2B formed by this. In the example of Fig. 1, the heat-sealing layer is directly formed into a film by a extrusion coating method on a substrate such as paper. In the example of Fig. 2, the heat-sealing layer 2 is prepared in a film form in advance. The adhesive 4 is used to bond with a substrate such as a plastic film.

As a base material, the paper, the metal foil, the single body of a plastic film, or what laminated | stacked two or more types can be used. The plastic film may be a deposited film in which an oxide such as silica or alumina or a metal thin film such as aluminum is formed.

As shown in Fig. 1, the heat sealing layer 2 of the packaging material of the present invention is a resin layer in which 55 to 75 parts by weight of low density polyethylene and 45 to 25 parts by weight of polybutene-1 are mixed ( 2A) and the resin layer 2B which consists of an ethylenically unsaturated carboxylic acid copolymer are laminated | stacked without passing through an adhesive layer by the coextrusion method. In the lamination with the base material 3, the said heat sealing layer 2 arrange | positions the resin layer 2B side which consists of the said ethylenically unsaturated carboxylic acid copolymer on the base material side, and laminates it. In other words, the heat sealing layer 2 is laminated | stacked facing the base material on the resin layer 2B side.

The mixture layer 2A of the low density polyethylene and polybutene-1 forms a release layer capable of generating cohesive failure upon opening. Polybutene-1 is substantially incompatible with low-density polyethylene, and since these mixtures form a so-called "sea island structure", the cohesive force of the exfoliation layer can be reduced to express the ease of exfoliation of the cohesive failure type. When the blending ratio of polybutene-1 is less than 25% by weight, the peel strength is too strong, so that when the polyethylene coated paper is used as the adherend, paper peeling occurs. When the compounding ratio of polybutene-1 exceeds 45 weight%, peeling strength becomes inadequate and it becomes easy to produce stickiness more.

As the ethylenically unsaturated carboxylic acid copolymer, EMAA (ethylene methacrylic acid copolymer) or EAA (ethylene acrylic acid copolymer) can be used. By providing the resin layer 2B of the ethylenically unsaturated carboxylic acid copolymer adjacent to the peeling layer, the cohesive failure of the peeling layer at the time of opening can be concentrated in the vicinity of the boundary line between the 2A layer and the 2B layer, and the peel strength is stabilized. The occurrence of stickiness can be suppressed. Moreover, by providing the layer of an ethylenically unsaturated carboxylic acid copolymer, there exists an effect of suppressing the curl at the time of laminating | stacking a heat sealing layer with a base material.

By laminating the 2A layer and the 2B layer, the heat seal layer can be easily formed at a predetermined layer ratio. As a lamination method of the heat sealing layer 2 and the base material 3 which are formed by 2A layer and 2B layer, the dry lamination method, the sandwich lamination method, the co-extrusion lamination method, etc. can be used.

When the thickness of the 2A layer of the heat seal layer is less than 5 µm, the sealing strength tends to be unstable, and the encapsulation of the complex is also insufficient. When the thickness of the 2A layer of the heat seal layer exceeds 15 µm, stickiness is likely to occur at the time of opening. On the other hand, when the thickness of the 2B layer forming the heat seal layer is thinner than the 2A layer, the curl when the heat seal layer is laminated with the base material becomes larger, and the lamination processing of the 2A layer and the 2B layer by the coextrusion method is also difficult. .

When the melting point of the low density polyethylene contained in the said 2A layer of a heat sealing layer exceeds 110 degreeC, the heat sealing strength at low temperature will become weak and stickiness will also arise easily. Moreover, when linear low density polyethylene which is a copolymer of ethylene and an alpha olefin, and so-called LLDPE is used for 2A layer, sealing strength becomes strong and paper peeling becomes easy to occur. As a low density polyethylene used for the said 2A layer of a heat sealing layer, the high pressure method low density polyethylene of the range of density 0.915-0.920 and MFR is 0.5-50, Preferably it is 20-50 is suitable.

If melting | fusing point of polybutene-1 is less than 120 degreeC, sealing strength will become strong and paper peeling will occur easily at the time of peeling. When butene-1 is mainly used and the copolymer which copolymerized the said butene-1 and another olefin is used, sealing strength becomes strong and paper peeling easily arises. It is preferable to use the polybutene-1 which has a density of 0.905 to 0.917 and MFR in a range of 0.2 to 20.

EMAA and EAA can be used suitably as an ethylenically unsaturated carboxylic acid copolymer of the 2B layer of a heat sealing layer. If the melting point of the ethylenically unsaturated carboxylic acid copolymer is higher than the low density polyethylene used for the 2A layer, stickiness tends to occur at the time of opening. EMAA can use suitably the thing of the density of 0.930-0.940, and MFR of 2-20. As EAA, the thing of the range of the density of 0.924-0.941 and MFR of 2-20 can be used suitably.

Below, the opening of the container using the packaging material of this invention is demonstrated. As shown in Fig. 3A, the heat seal layer of the packaging material 1 of the present invention is faced to the heat seal layer of the adherend 10 and heat sealed by the hot plate 30 to form a heat seal portion ( 13). When the heat sealing part 13 is peeled off (opened), as shown in Fig. 3B, a cohesive failure 14 is generated in a 2A layer made of a mixed resin of the heat sealing layer 2, so that it is easily opened. The peeling surface without stickiness is formed.

In the case where the base material 3 on which the heat seal layer 2 is laminated is a plastic film such as paper, aluminum foil, or polyethylene, the heat seal layer 2 composed of 2A layers and 2B layers is formed by using a coextrusion laminate method. It can be laminated directly on a substrate, which simplifies the manufacturing process.

The packaging material of the present invention can be suitably used as the lid member 21 heat sealed to the polyethylene coat paper cup container 22, as shown in Fig. 4A. The paper container presses the lip curl of the container body 22 to form a smooth flange 23, and seals the lid member 21 by heat sealing the flange part. At the time of opening, the heat-sealed part of a lid member is peeled off. The state which peeled for opening using the packaging material of this invention as a cover member is shown to FIG. 4 (d). The paper containers are widely used for foods such as instant noodles, yogurt, snacks, and shredded soybean meal. By using the packaging material of this invention as a cover member of the said paper container, it was possible to give the peeling surface the outstanding ease of opening, and to prevent the sticking of the peeling surface conventionally seen in a paper container.

Next, although the Example is demonstrated and demonstrated concretely about the packaging material and container of this invention, this invention is not limited by these.

<First Embodiment>

A mixture of 65 parts by weight of low-density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) was used as a release layer as a first layer (thickness 10 μm), and an ethylene methacrylic acid copolymer (hereinafter referred to as “ EMAA ”(melting point 98 ° C.) as the second layer (thickness of 20 μm), while the ozone treatment was performed on the EMAA layer side, the paper was subjected to an extrusion temperature of 300 ° C. on corona-treated paper (100 g / m 2). Extrusion lamination was performed and the packaging material of the following structure was obtained.

Paper (100 g / m 2) / EMAA (20 μm) / peel layer (10 μm)

<2nd Example>

A mixture of 65 parts by weight of low-density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) was used as the release layer as the first layer (thickness 10 μm), and EMAA (melting point 98 ° C.) was used as the second layer ( 20 micrometers) was co-extruded to the aluminum foil (50 micrometers in thickness) by extrusion temperature 300 degreeC, and the packaging material of the following structure was obtained.

Aluminum foil (50 μm) / EMAA (20 μm) / peel layer (10 μm)

<Third Embodiment>

Instead of EMAA, it carried out similarly to Example 1 using the ethylene acrylic acid copolymer (it describes as "EAA" hereafter) (melting point 96 degreeC). That is, a mixture of 65 parts by weight of low-density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) is used as the release layer as the first layer (thickness 10 μm), and EAA (melting point 96 ° C.) is used as the second layer. The layer (thickness 20 µm) was co-extruded at an extrusion temperature of 300 ° C. on the corona treated paper (100 g / m 2) while performing ozone treatment on the EAA layer side to obtain a packaging material having the following structure.

Paper (100 g / m 2) / EAA (20 μm) / peel layer (10 μm)

<Fourth Example>

Multi-layer inflation molding method using a mixture of 65 parts by weight of low density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) as a release layer and EMAA (melting point 98 ° C.) as a second layer. After the sealant film was produced and subjected to corona treatment on the EMAA side of the film, dry lamination was performed on one surface side of the 16 μm-thick PET film using a two-component curable urethane adhesive to obtain a packaging material having the following structure.

PET (16 µm) / Adhesive Layer / EMA (20 µm) / Peeling Layer (10 µm)

<Fifth Embodiment>

A mixture of 65 parts by weight of low density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) was used as the first layer (20 μm) as a release layer, and EMAA (melting point 98 ° C.) was used as the second layer (10). (Micrometer), co-extrusion lamination was carried out at the extrusion temperature of 300 degreeC on the corona-treated paper (100 g / m <2>), performing ozone treatment on the EMAA layer side, and obtained the packaging material of the following structure.

Paper (100 g / m 2) / EMAA (20 μm) / peel layer (10 μm)

<Sixth Example>

A mixture of 65 parts by weight of low-density polyethylene (melting point 111 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) was used as the first layer (10 μm) as a release layer, and EMAA (melting point 98 ° C.) was used as the second layer 20 (Micrometer), co-extrusion lamination was carried out at the extrusion temperature of 300 degreeC on the corona-treated paper (100 g / m <2>), performing ozone treatment on the EMAA layer side, and obtained the packaging material of the following structure.

Paper (100 g / m 2) / EMAA (20 μm) / peel layer (10 μm)

<7th Example>

A mixture of 65 parts by weight of low density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 100 ° C.) was used as the first layer (10 μm) as a release layer, and EMAA (melting point 98 ° C.) was used as the second layer 20 (Micrometer), co-extrusion lamination was carried out at the extrusion temperature of 300 degreeC on the corona-treated paper (100 g / m <2>), performing ozone treatment on the EMAA layer side, and obtained the packaging material of the following structure.

Paper (100 g / m 2) / EMAA (20 μm) / peel layer (10 μm)

<Eighth Embodiment>

A mixture of 65 parts by weight of low-density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) was used as the first layer (10 μm) as a release layer, and EMAA (melting point 105 ° C.) was used as the second layer 20 (Micrometer), co-extrusion lamination was carried out at the extrusion temperature of 300 degreeC on the corona-treated paper (100 g / m <2>), performing ozone treatment on the EMAA layer side, and obtained the packaging material of the following structure.

Paper (100 g / m 2) / EMAA (20 μm) / peel layer (10 μm)

<First comparative example>

A mixture of 80 parts by weight of low-density polyethylene (melting point 105 ° C.) and 20 parts by weight of polybutene-1 (melting point 125 ° C.) was used as the release layer as the first layer (thickness 10 μm), and EMAA (melting point 98 ° C.) was used as the second layer ( 20 micrometers (thickness), co-extrusion lamination | stacking was carried out at the extrusion temperature of 300 degreeC on the corona-treated paper (100 g / m <2>), performing ozone treatment on the EMAA layer side, and obtained the packaging material of the following structure.

Paper (100 g / m 2) / EMAA (20 μm) / peel layer (10 μm)

<The second comparative example>

A mixture of 50 parts by weight of low-density polyethylene (melting point 105 ° C.) and 50 parts by weight of polybutene-1 (melting point 125 ° C.) was used as the first layer (10 μm) as a release layer, and EMAA (melting point 98 ° C.) was used as the second layer 20 (Micrometer), co-extrusion lamination was carried out at the extrusion temperature of 300 degreeC on the corona-treated paper (100 g / m <2>), performing ozone treatment on the EMAA layer side, and obtained the packaging material of the following structure.

Paper (100 g / m 2) / EMAA (20 μm) / peel layer (10 μm)

<Third comparative example>

A mixture of 65 parts by weight of low density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) was used as the first layer (thickness 10 μm) as a release layer, and low density polyethylene (LDPE) (melting point 105 ° C., density) was used. Coextrusion lamination was performed at an extrusion temperature of 300 ° C. on corona-treated paper (100 g / m 2) while the ozone treatment was performed on the LDPE layer side with = 0.92 and MFR = 7) as the second layer (thickness 20 μm). The packaging material of the following structure was obtained.

Paper (100 g / m 2) / LDPE (20 μm) / peel layer (10 μm)

<The fourth comparative example>

A mixture of 65 parts by weight of linear low density polyethylene (hereinafter referred to as "LLDPE") (melting point 110 ° C) and 35 parts by weight of polybutene-1 (melting point 125 ° C) was used as a release layer as a first layer (10 탆). , Co-extrusion lamination at the extrusion temperature of 300 ° C. was performed on the corona treated paper (100 g / m 2), with the second layer (20 μm) as EMAA (melting point 98 ° C.) and ozone treatment on the EMAA layer side. The packaging material of the structure was obtained.

Paper (100 g / m 2) / EMAA (20 μm) / peel layer (10 μm)

<exam>

A cup paper (280 g / m 2) extruded and coated with a low-density polyethylene having a melting point of 106 ° C. with a thickness of 20 μm was molded into a cup shape having a flange portion, and the packaging material prepared according to the first embodiment was covered with the flange portion. Using as a member, after heat-sealing on 150 degreeC and the conditions of 0.6 second, it opened, and the cross section of the peeling surface was observed under the microscope. Since the peeling layer of the lid member was observed on both the lid member side and the cup side, it was confirmed that the peeling layer was cohesive-broken at the time of opening.

In addition, the packaging material prepared in each Example and Comparative Example was heat-sealed on the cup base paper (280g / m <2>) extrusion-coated with the low-density polyethylene (20 micrometers in thickness) of melting | fusing point 106 degreeC on the conditions of 140 degreeC, 98 Kpa, and 1 second, The peeling strength and the sticking state of the peeling surface were compared. Curls were evaluated by visual observation.

Ease of opening and curling in Examples and Comparative Examples were as follows.

Peel Strength (N / 15mm) Sticky of peeling surface curl Example One 5.5 radish small 2 5.0 radish small 3 5.5 radish small 4 6.5 radish small 5 4.5 Slightly more medium 6 4.0 Slightly more small 7 7.0 radish small 8 3.0 Slightly more medium Comparative example One Paper peeling - small 2 2.5 Slightly more small 3 5.0 plenty versus 4 Paper peeling - small

The packaging material of the first to fourth embodiments exhibited adequate peel strength, and the curl was small without causing stickiness of the peeling surface. Since the thickness of the EMAA layer was slightly thin compared to the release layer, the packaging material of Example 5 was slightly more noticeable and slightly sticky. Since the melting point of the low density polyethylene was slightly higher, the packaging material of Example 6 was slightly weaker in peel strength and slightly more sticky. Since the melting point of polybutene-1 was slightly low, the packaging material of Example 7 was slightly stronger in peel strength. The packaging material of Example 8 had a slightly higher melting point of EMAA, which was the same as that of low density polyethylene, so that it was slightly sticky, had a weak peel strength, and had a slight curl.

Since the packaging material of the 1st comparative example is too small the compounding ratio of polybutene-1, peeling strength was too strong and paper peeling generate | occur | produced. In the packaging material of the second comparative example, since the blending ratio of polybutene-1 was too large, the peeling strength was too weak, and the stickiness was also slightly increased. Since the low density polyethylene was used instead of the ethylenically unsaturated carboxylic acid copolymer as a 2nd layer for the packaging material of a 3rd comparative example, it was many sticky and large curl. Since the packaging material of the 4th comparative example used LLDPE instead of low density polyethylene, peeling strength was too strong and paper peeling occurred.

<Example 9>

A mixture of 60 parts by weight of low-density polyethylene (melting point 106 ° C.) and 40 parts by weight of polybutene-1 (melting point 125 ° C.) was passed to the aluminum foil side of the substrate having a layer structure of [paper / polyethylene / aluminum foil] through a urethane-based anchor. Coextrusion laminate at an extrusion temperature of 260 ° C. while making the first layer (thickness 10 μm) as the release layer, and making the EMAA (melting point 100 ° C.) the second layer (thickness 30 μm) and performing ozone treatment on the EMAA layer side. It carried out and obtained the packaging material of the following structure.

[Paper (76 g / m 2) / polyethylene (20 μm) / aluminum foil (7 μm) / EMAA (30 μm) / peel layer (10 μm)]

This packaging material was used as a lid member of a paper cup for instant noodles (immediate noodles) molded from a paper (280 g / m 2) coated with polyethylene having a melting point of 110 ° C., so that peeling and stickiness at the time of opening did not occur. The easy opening container which was excellent in sealing property and heat resistance was obtained.

<Example 10>

A mixture of 70 parts by weight of low density polyethylene (melting point 105 ° C.) and 30 parts by weight of polybutene-1 (melting point 125 ° C.) through a urethane-based anchor on the PET side of the substrate having a layer structure of [paper / polyethylene / aluminum foil / PET] Is the first layer (thickness 10 µm) as the release layer, EMAA (melting point 98 ° C) is the second layer (thickness 40 µm), and coextruded at an extrusion temperature of 250 ° C while performing ozone treatment on the EMAA layer side. It laminated and obtained the packaging material of the following structure.

[Paper (79 g / m 2) / polyethylene (20 μm) / aluminum foil (7 μm) / PET (12 μm) / EMAA (40 μm) / peel layer (10 μm)]

A snack formed by molding the packaging material using a paper having a layer structure of [paper (210 g / m 2) / polyethylene (20 μm) / aluminum foil (7 μm) / EMAA (10 μm) / polyethylene (20 μm)]. When used as a cover member of the paper cup for confectionery, the peeling and stickiness at the time of opening did not occur, and the easily openable container excellent in sealing property and heat resistance was obtained.

<Eleventh Example>

A mixture of 65 parts by weight of low density polyethylene (melting point 105 ° C.) and 35 parts by weight of polybutene-1 (melting point 125 ° C.) on the aluminum foil side of the substrate having a layer structure of [PET (12 μm) / aluminum foil (10 μm)]. To a first layer (thickness 10 µm) as a release layer, EMAA (melting point 100 ° C) as a second layer (thickness 35 µm), and coextrusion lamination at an extrusion temperature of 290 ° C to obtain a packaging material having the following structure. .

[PET (12 μm) / Aluminum foil (10 μm) / EMAA (35 μm) / peel layer (10 μm)]

This packaging material was used as a lid member of a paper cup for yogurt formed by paper coated with polyethylene having a melting point of 107 ° C. (240 g / m 2), so that paper peeling and stickiness at the time of opening were not generated, and the sealing and heat resistance were excellent. Easily opened containers were obtained.

The packaging material of this invention has a heat sealing layer containing a peeling layer. When the heat sealing part sealed by the heat sealing system using this packaging material is peeled and opened, cohesive failure will generate | occur | produce in a peeling layer and it will show ease of opening. In addition, it does not generate stickiness of the opening.

And when this packaging material is used as a cover member of the paper cup which an inner surface consists of polyethylene, the sealed paper cup which has openability can be obtained. The container thus obtained is very usable for the consumer.

Claims (5)

It consists of at least a base material and a heat sealing layer provided on one surface side of the base material, and the heat sealing layer comprises 55 to 75 weight of a resin layer (B) made of an ethylenically unsaturated carboxylic acid copolymer and a low density polyethylene from a side close to the base material. The resin layer (A) and the resin layer (B) were coextruded in such a manner that the resin layer (A) containing the portion and the polybutene-1 at a ratio of 45 to 25 parts by weight was formed in this order. It is laminated | stacked on each other by the easy packaging material characterized by the above-mentioned. The thickness of the said resin layer (A) is the range of 5-15 micrometers, and the thickness of the said resin layer (B) is more than the thickness of the resin layer (A), The packaging material of Claim 1 characterized by the above-mentioned. The low-density polyethylene is a high-pressure low-density polyethylene having a melting point of 110 ° C. or lower, the polybutene-1 is a homopolymer having a melting point of 120 ° C. or higher, and the melting point of the ethylenically unsaturated carboxylic acid copolymer. It is lower than melting | fusing point of this said low density polyethylene, The packaging material characterized by the above-mentioned. The said heat sealing layer is laminated | stacked on the said base material by the coextrusion laminating method, The packaging material in any one of Claims 1-3 characterized by the above-mentioned. The packaging material of Claims 1-4 is heat-sealed as a cover member of the paper cup container which coat | covered polyethylene of melting | fusing point 105-115 degreeC in the innermost layer, The resin layer A is cohesive-broken at the time of opening, It is characterized by the above-mentioned. Easy to open container.