JP3654966B2 - Lid material - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a paper container lid material having polyethylene laminated on its inner surface, and more particularly to a paper container lid material filled with dairy products such as yogurt, fruit juice, jelly and other foods.
[0002]
[Prior art]
Conventionally, the base material layer that constitutes the cover material of paper containers includes paper, aluminum foil, plastic film, etc. Especially those that use paper as the base material layer have a reinforcing action on the flange as a container shape holder Was used as.
For example, paper is used as a base material layer, and it is configured as follows.
(1) Paper / low density polyethylene (adhesive layer) / high density polyethylene (reinforced layer) / low density polyethylene (heat seal layer).
(2) Paper / low density polyethylene (adhesive layer) / polyester film (reinforced layer) / low density polyethylene (heat seal layer).
These lid materials prevent tearing of the lid paper at the time of opening, and have a fitting property with a plastic overcap used for a paper container after opening. Further, as shown in FIG. 4A, when the common lid member 14 provided with a plurality of paper containers 16 is sealed, and the bent portion 14P of the lid member is provided to be consolidated into multiples, the flange portion is strengthened. Thus, the shape retaining property of the multiple paper container is provided. The multiple paper container is cut at the cutting portion 8 to be in a single state as shown in FIG. 4B, and the inner polyethylene layer 16P is peeled off at the flange portion 17 and cut at the flange end portion 18. Open.
[0003]
[Problems to be solved by the invention]
However, both lid materials require considerable force when opened, and the paper of the flange portion of the paper container is torn together with the inner polyethylene layer at the time of opening. Depending on the contents, moisture may be absorbed into the flange, reducing the rigidity of the container and causing the container to be crushed or impairing the fit with the plastic overcap. There was a problem of falling off or spilling liquid contents.
The present invention reduces the force at the time of opening, prevents the cover material and the paper container flange from being peeled, maintains the appearance and strength of the flange part, and reduces the rigidity of the paper container due to water absorption of the flange part. It aims at supplying the lid material which does not raise | generate.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a lid material provided with a heat seal layer that is sealed by adhering to a flange portion of a paper container laminated with polyethylene on the inner surface and having an easy-opening property. Lamination of at least a base material layer, an easily peelable layer made of a polymer, a polymer alloy or a polymer blend, and a heat seal layer that can be easily peeled from the easily peelable layer and thermally bonded to the flange portion, and can be easily cut Ri Na from the object, the substrate layer is formed of a laminate with paper or aluminum foil and the reinforcing layer, the easy peel layer, a polymer consisting mainly of polypropylene, is formed of a polymer alloy or polymer blend, the The heat seal layer is formed of an ethylene homopolymer or copolymer, and the laminate of the easily peelable layer and the heat seal layer is formed by coextrusion film formation or coextrusion. Coating is formed by, and the thickness of the heat seal layer is a lid material of 2 to 15 [mu] m.
[0005]
The lid material of the present invention is sealed by adhering to the flange portion 17 of the container 15 as shown in FIG. 1, and in the lid material 10 provided with the heat seal layer 5 having easy-openability, the lid material is: It is a lid material made of a laminate of a base material layer 1, an easily peelable layer 3 made of a polymer, a polymer alloy or a polymer blend, and a heat seal layer 5 that can be thermally bonded to the flange portion 17 and can be easily cut.
And the laminated body with said easily peelable layer 3, the heat seal layer 5, and the base | substrate layer 4 provided as needed is the coextruded film 7 comprised by coextrusion film forming or coextrusion coating.
Moreover, it is the cover material 10 whose thickness of the heat seal layer 5 is 2-15 micrometers.
[0006]
For the base material layer 1 used for the lid material of the present invention, a cup base paper rich in size, a paper having a basis weight of 100 to 250 g / m ² , or an aluminum foil having a thickness of 15 to 100 μm is used. Further, paper and plastic are bonded to provide a reinforcing layer on the paper surface to prevent paper peeling, aluminum foil is bonded, and aluminum, silicon oxide, aluminum oxide, etc. are deposited to provide barrier properties. In some cases, a heat seal layer is provided on the processed material.
[0007]
The reinforcing layer 2 provided on the base material layer of the present invention is provided to reinforce the paper surface as required when paper is used for the base material layer 1 of the lid, and is made of polyester, nylon, medium density polyethylene, High-density polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, ionomer, polycarbonate, cellulose triacetate, saponified ethylene / vinyl acetate copolymer, etc. Or the thickness of an unstretched film can be selected from 10 to 40 μm.
Further, the lamination of the paper and the reinforcing layer can be made by a usual lamination method such as sandwich lamination using low density polyethylene as an adhesive layer, dry lamination using a reactive adhesive, wet lamination using an emulsion adhesive, and the like. .
[0008]
The easy release layer 3 made of a polymer, a polymer alloy or a polymer blend includes a propylene homopolymer, copolymer, etc. as the polymer. The polymer alloy or polymer blend includes not only polypropylene and other thermoplastic resins. polypropylene and elastomer, an inorganic or organic fine particles, or a mixture of such surfactants impart releasability to use.
The other thermoplastic resin and elastomer include polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer, ionomer, saponified ethylene / vinyl acetate copolymer, In addition to thermoplastic resins such as polyvinyl butyral, polyamide, polyester, polycarbonate and polystyrene, heat resistant resins such as fluororesin and silicone, cellulose derivatives such as ethyl cellulose, methyl cellulose and cellulose acetate, polybutene, propylene rubber, polybutadiene and the like There is an elastomer.
Examples of the inorganic or organic fine particles include barium sulfate, silica, talc, calcium carbonate, and bead pigments such as polyurethane, acrylic, polycarbonate, and epoxy.
The thickness of the easy peeling layer is 10 to 40 μm although it depends on the material used. If it is 10 μm or less, the peelability is uneven, and if it is 40 μm or more, processing during film formation becomes difficult.
[0009]
Since the heat seal layer of the present invention is thin, easily cut and easily peeled, it is preferable to form a film by coextrusion with a material that has easy peelability and is easy to form. In addition, on the other surface of the easily peelable layer, if necessary, a three-layer coextrusion film formation using a polymer alloy having adhesiveness to the easily peelable layer or a copolymer as a base layer is performed to stabilize the film formation. It is also possible to provide processing suitability such as adhesion and adhesion to the base material layer.
[0010]
The heat seal layer of the present invention is preferably a resin that can be heat sealed with the inner surface resin layer of the paper container. Usually, polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer A polymer, an ionomer, an ethylene / vinyl acetate copolymer saponified product, or the like is selected. And it is preferable to form as thin as possible so that it may be cut | disconnected by the heat seal edge part at the time of opening of a container. The thickness is 2 to 15 μm, preferably 5 to 10 μm, although it depends on the resin used. If it is 2 μm or less, the heat seal layer is broken when heat-sealing, resulting in poor adhesion, and if it is 15 μm or more, the heat-seal layer is not cut when opened, and a thin heat-seal layer remains on the container.
Moreover, when a container is used for dairy products, it is preferable to use a homopolymer of polyethylene.
[0011]
[Action]
The lid material of the present invention is configured by providing a heat seal layer with an easy-release layer in the layer configuration. Therefore, after heat sealing, when opening, the heat seal layer is cut by the opening force, and the flange surface is delaminated with the easily peelable layer. Has the effect of.
Further, since the paper is not peeled at the time of opening, the paper strength is prevented from lowering due to water absorption at the flange portion of the paper container after opening.
[0012]
【Example】
[Example 1]
An example will be described with reference to the drawings. In FIG. 2, one side of a base paper having a basis weight of 170 g / m ² as the paper 20 and a treated surface of the biaxially stretched polyester film 21 having a thickness of 12 μm, Polypropylene which is a copolymer of the other side of the polyester film, the ethylene acrylate copolymer (EEA) layer 41, and ethylene mainly composed of propylene, sandwich lamination using a polyethylene layer 61 having a thickness of 20 μm. The present invention is formed by sandwich lamination of the EEA layer 41 of the three-layer coextruded film 71 formed of the layer 35 and the polyethylene layer 51 and having a thickness of 10 μm, 15 μm and 5 μm, respectively, using a polyethylene layer 62 having a thickness of 15 μm. The lid member 11 of Example 1 was configured.
When the lid 11 is heat-sealed with the flange 17 of the paper container 16 and then peeled, the polyethylene layer 51 is cut at the peripheral edge of the flange 17 of the paper container as shown in FIG. The film was peeled off between layers with No. 35 and opened without any peeling.
[0013]
Example 2
In FIG. 3, one side of a cup base paper having a basis weight of 170 g / m ² as the paper 20 and a primer layer 66 of a polypropylene film 23 having a thickness of 25 μm provided with a primer layer 66 on the treated surface are provided with a thickness of 20 μm. Sandwich lamination was performed using the polyethylene layer 61. Furthermore, a coextruded coating layer 72 is provided on the other surface of the polypropylene film 23 such that a polypropylene layer 33 and a polyethylene layer 52 of a copolymer of ethylene mainly composed of propylene have a thickness of 15 μm and 5 μm, respectively. The lid member 12 of Example 2 of the present invention was configured.
The polypropylene film 23 of the lid material and the co-extrusion-coated polypropylene layer 33 provide the properties of the reinforcing layer and the easily peelable layer of the present invention.
When the lid 12 is heat-sealed with the flange 17 of the paper container 16 and then peeled, the polyethylene layer 52 is cut at the peripheral edge of the flange 17 of the paper container 16 as shown in FIG. It was peeled off between the layers and opened without any paper breaks.
[0014]
[Example 3]
Although not shown, instead of the paper of Example 1, 40 μm of aluminum foil was used, and a biaxially stretched polyester film was sandwich-laminated using a polyethylene layer, and the other side of the polyester film, an EEA layer, propylene The lid material of Example 3 of the present invention is obtained by sandwich lamination of a three-layer coextruded film consisting of a polypropylene layer, which is a copolymer of ethylene mainly composed of ethylene, and an EEA layer of a polyethylene layer, using a polyethylene layer having a thickness. Configured.
When the lid material was heat sealed with the flange of the paper container and then peeled off, the polyethylene layer was cut at the peripheral edge of the flange of the paper container and peeled off between the layers of the copolymer polypropylene layer and opened.
[0015]
【The invention's effect】
The lid material of the present invention configured as described above has an easy-opening property that does not cause paper peeling due to delamination between the heat-peeling layer and the heat-seal layer after the heat-sealing, at the time of opening. The lid could be constructed.
Further, since the paper is not peeled at the time of opening, the paper strength is prevented from being lowered due to water absorption at the flange portion after opening.
[Brief description of the drawings]
FIG. 1A is a schematic cross-sectional view showing a layer structure of a lid material of the present invention.
(B) It is a cross-sectional schematic diagram which shows the external appearance of the peeling part of the said cover material.
FIG. 2A is a schematic cross-sectional view showing a layer structure of a lid material of an example.
(B) It is a cross-sectional schematic diagram which shows the external appearance of the peeling part of the said cover material.
FIG. 3A is a schematic cross-sectional view showing a layer structure of a lid material of another embodiment.
(B) It is a cross-sectional schematic diagram which shows the external appearance of the peeling part of the said cover material.
FIG. 4A is a schematic perspective view showing an aggregated state of a multiple-type paper container provided with a lid material.
(B) It is AA sectional drawing of the paper container cut | disconnected by one.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base material layer 2 Reinforcement layer 3 Easily peelable layer 4 Base layer 5 Heat seal layer 6 Adhesive layer 8 Cutting part 10, 11, 12, 14 Cover material 14P Bending part 15 Container 16 Paper container 16P Inner surface polyethylene layer 17 Flange part 18 Flange Edge 20 Paper 21 Polyester film 23 Polypropylene film 33 Polypropylene layer 35 Copolymer polypropylene layer 41 EEA layers 51 and 52, polyethylene layers 61 and 62 Polyethylene layer 66 Primer layers 7 and 71 Coextruded film 72 Coextruded coating layer

Claims (1)

A lid that is thermally bonded to and sealed with a polyethylene layer of a flange portion of a paper container having a polyethylene layer laminated on the inner surface, the lid material reinforcing a base layer and a surface of the base layer; Are laminated by sand lamination using polyethylene as an adhesive layer, and further, ethylene acrylate copolymer and ethylene mainly composed of propylene are formed on the surface of the reinforcing layer obtained by laminating the base material layer and the reinforcing layer. And an ethylene acrylate copolymer layer coextruded with polyethylene, a polypropylene layer, and a polyethylene layer, and the polyethylene layer has a thickness of 2 to 15 μm. The layer coextruded film has a configuration in which polyethylene is used as an adhesive layer for lamination, and further comprises a polyethylene layer in the flange portion of the paper container, When the polyethylene layer of the three-layer coextruded film constituting the lid material is thermally bonded and sealed, on the other hand, when the lid material is peeled off and opened, it is cut at the polyethylene layer and the polyethylene layer. A lid material characterized by delamination between a polypropylene layer and a polypropylene layer .

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