JP2000085058A - Laminated material for packaging and lid material and pouch using laminated material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated material for packaging which is free from the generation of a curl without the use of a metallic foil, and a lid material and a pouch using the laminated material. SOLUTION: This laminated material 1 for packaging is constituted of a layer 2 formed mainly of paper with 50-150 μm thickness, a synthetic resin film layer 3 and a sealant layer 4 with 15-50 μm thickness. When the thicknesses of the layers 2, 3, 4 are given as A, B and C, the thickness of each of the layers 2, 3, 4 is selected so that A>=B+C is established. The laminated material 1 can be formed into a lid material of appropriate shape and also can be used for forming a pouch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated material used mainly for packaging foods and beverages, a lid material used for containers made of synthetic resin, and a pouch for packaging.

[0002]

2. Description of the Related Art In recent years, aluminum foil has been increasingly used as a packaging material from the standpoint of environmental protection and resource saving. ing. In addition, for shipping inspection of foods and beverages, an increasing number of manufacturers are installing metal detectors, and a packaging material that does not use metal foil at all is required.

[0003] In response to these circumstances, recently, a packaging material composed of only a synthetic resin film and a packaging material composed of a laminate of a synthetic resin film and paper have been on the market.

[0004]

However, in a packaging material using no metal foil, the rigidity (also referred to as "stiffness") is weak, and the laminate and the lid material are easily curled, especially in a cold region. When used, the curl is large, and the automatic filling machine for food often suffers an obstacle, and the correction requires a lot of labor and time to reduce the productivity.

Accordingly, an object of the present invention is to provide a packaging material which does not curl without using a metal foil.

[0006]

In order to solve the above-mentioned problems, the present invention provides (A) a layer mainly composed of paper having a thickness of 50 to 150 μm, (B) a layer made of a synthetic resin film alone or a composite, (C) In a packaging laminate in which a sealant layer having a thickness of 15 to 50 μm is laminated, the thickness of each layer of (A), (B) and (C) is such that (A) ≧ (B) + (C). It was.

[0007] a layer composed mainly of the paper is the one-side coated paper, the stiffness of the vertical 20 to 100 ^3/100, horizontal 15
Is preferably ~80cm ^3/100.

A lid or a pouch is formed using the laminated material.

[0009]

[Action] In the case of a conventional laminated material consisting of only synthetic resin,
Temperature differences (especially transporting lids etc. from temperate areas to cold areas,
(When used), a shrinkage force was generated in the sealant layer, and as a result, curling with the sealant layer inside was found to occur. This is because the sealant layer has a higher coefficient of thermal expansion than the other reinforcing resin layers or outer layer films. In order to prevent this, curl can be prevented by using paper (A) having a specific rigidity (stiffness) and a specific ratio of the thickness with the synthetic resin layer (B + C). is there.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, a packaging laminate 1 of the present invention comprises a paper 2, a synthetic resin film layer 3 and a sealant layer 4.

The paper 2 is made of pure white roll paper, kraft paper,
Fine paper, imitation paper, western paper, Japanese paper, various coated papers and the like can be used, and use of single-side coated paper is most preferable. Various types of printing, an overcoat layer of about 1 μm, or the like may be applied to the outer surface of the paper 2 opposite to the film layer 3. Of course, printing or the like may be performed on the surface to be bonded to the film layer 3. On one side coated paper,
For example, "Ryuocoat A" (manufactured by Nagoya Pulp Co., Ltd.) can be used. The thickness of the paper is suitably 50 to 150 μm, preferably about 70 to 130 μm. In addition, the stiffness of the paper, the vertical 20~100cm ^3/100, horizontal 15-8
Preferably 0 cm ^3/100, more preferably vertical 40
~100cm ^3/100, horizontal 25~80cm ^3/100
It is about. Paper thickness less than 50 μm, rigidity (vertical) 20
cm ^3/100, or less than stiffness (lateral) 15cm ^3/10
If it is less than 0, the paper strain is weak and the effect of preventing curling is poor. On the other hand, when the thickness of the paper exceeds 150 μm,
If more than a case or rigidity (lateral) 80 cm ^3/100 exceeds stiffness (vertical) 100 cm ^3/100 has the flexibility of the laminate 1 is poor, slip stick phenomenon occurs upon opening, the easy-open Inhibit. On the other hand, if the thickness of the paper is too large (more than 150 μm), heat conduction at the time of heat sealing deteriorates, which may undesirably increase the sealing time or cause poor sealing.

The synthetic resin film layer 3 is formed of a synthetic resin film alone or a composite, and may be either a stretched film or an unstretched film. The type of resin is
Polystyrene (hereinafter, PS), polyethylene (hereinafter, P
E), polypropylene (hereinafter, PP), polyester,
Polyethylene terephthalate (hereinafter, PET), polyamide (hereinafter, NY), polyurethane, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer (hereinafter, EVOH) and the like can be used. Further, the barrier property can be improved by using a film in which aluminum, silica, alumina, or the like is deposited at an arbitrary position.

As the sealant layer 4, a synthetic resin that can be sealed to an adherend such as a container can be selected. For example, ethylene-
A product containing vinyl acetate copolymer (hereinafter, EVA) as a main component or a product obtained by blending PP and PE (hereinafter, PPE)
Etc. can be used. If the adhesion between the sealant layer 4 and the synthetic resin film layer 3 is poor, an adhesive and PE
The adhesion (adhesion strength) can be improved by interposing a resin or the like.
Shall be included.

In the laminated material 1, when the thickness of the paper 2 is (A), the thickness of the layer 3 is (B), and the thickness of the layer 4 is (C), the relationship of the thickness of each layer satisfies the following equation. It is necessary to.

(A) ≧ (B) + (C) More preferably 2.5 ≧ (A) / (B + C)
≧ 1 Here, when the film layer 3 is formed from a plurality of layers, (B) is the total thickness thereof. The thickness (A) of the paper 2 needs to be equal to or greater than the sum of the thicknesses of the other layers 3 and 4 (B) + (C). If it is less than the same, the effect of preventing curling will be insufficient. On the other hand, the upper limit of the thickness (A) of the paper 2 is preferably 2.5 times or less of (B + C). If the upper limit is exceeded, the flexibility of the laminated material 1 is impaired, or the thickness of the paper is unnecessarily reduced. It is not preferable because the thickness increases, the cost increases, and the time required for heat sealing increases.

The method for laminating and forming each layer of the laminated material 1 or each film and resin is not particularly limited, and dry lamination is carried out using a general adhesive such as polyether, polyester, or polyurethane. And a method of laminating by a resin extrusion method. Further, an anchor coat layer may be interposed between the respective layers as needed.

Examples and comparative examples will be described below.

[0018]

Example 1 After a polyurethane adhesive was applied to one side of a PET film having a thickness of 25 μm, the thickness was 75 μm and the rigidity (vertical) was 36.6 (horizontal) 2 by dry lamination.
6.4cm ^3/100 was bonded to the non-coated side of one side coated paper. After performing an anchor coat treatment on the PET film surface of the bonded material, the sealant layer is made of PE.
And EVA resin were formed by extrusion lamination. The PE film thickness after molding was 15 μm, and the EVA was 2 μm.
It was 5 μm.

[0019]

Example 2 After a polyurethane adhesive was applied to one side of a PET film having a thickness of 12 μm, the thickness was 100 μm and the rigidity (vertical) was 76.4 (horizontal) 2 by a dry lamination method.
9.2cm ^3/100 was bonded to the non-coated side of one side coated paper. After performing an anchor coat treatment on the PET film surface of the bonded material, the sealant layer is made of PE.
And EVA resin were formed by extrusion lamination. The PE film thickness after molding was 10 μm, and the EVA was 2 μm.
It was 5 μm.

[0020]

Example 3 After applying a polyurethane-based adhesive to one surface of a stretched PP film having a thickness of 8 μm, a thickness of 50 μm and a stiffness (length) of 38.0 (width) 2 were obtained by dry lamination.
2.7cm ^3/100 was bonded to the non-coated side of one side coated paper. After applying a polyurethane adhesive to the PP film surface of the bonding material, a modified polyethylene film having a thickness of 30 μm was bonded by a dry lamination method.

[0021]

Example 4 A polyurethane-based adhesive was applied to one side of a non-stretched EVOH film having a thickness of 12 μm, and then dried by a lamination method to a thickness of 80 μm and a rigidity (vertical) of 79.0.
It was bonded to the non-coated surface of one side coated paper (horizontal) 57.8cm ^3/100. After applying a polyurethane-based adhesive to the EVOH film surface of the bonding material, a modified polyethylene-based film having a thickness of 30 μm was bonded by a dry lamination method.

[0022]

Example 5 A 15 μm thick NY film was coated with a polyurethane-based adhesive on one side and then dried by a lamination method to a thickness of 60 μm and a rigidity (length) of 42.5 (width) of 25.3.
bonded to one side coated paper cm ^3/100. After performing an anchor coat treatment on the NY film surface of the bonding material, PE and EVA resin were formed as a sealant layer by extrusion lamination. The thickness of the PE after molding was 20 μm, and the EVA was 20 μm.

[0023]

Embodiment 6 A polyurethane adhesive is applied to one side of a NY film having a thickness of 25 μm, and a dry lamination method is used to obtain a film having a thickness of 120 μm and a rigidity (length) of 91.1 (width) 4.
2.3cm ^3/100 was bonded to one side coated paper.
After performing an anchor coat treatment on the NY film surface of the bonding material, PE and EVA resin were extruded as a sealant layer by a lamination method. Note that P
The film thickness of E after molding was 15 μm, and the EVA was 20 μm.

[0024]

Comparative Example 1 A polyurethane adhesive was applied to one surface of a PET film having a thickness of 25 μm, and then a thickness of 75 μm and a rigidity (vertical) of 36.6 (horizontal) 2 were obtained by dry lamination.
6.4cm ^3/100 bonded to non-coated side of one side coated paper. After performing an anchor coat treatment on the PET film surface of the bonding material, an EVA film having a thickness of 40 μm was bonded as a sealant layer by a PE extrusion lamination method. The PE has a thickness of 15 after drying.
μm.

[0025]

Comparative Example 2 A stretched PP film having a thickness of 12 μm (12 μm)
m), after applying a polyurethane-based adhesive on one side, dry lamination method to a thickness of 50 μm and a rigidity (vertical) of 3
8.0 bonded to one side coated paper (horizontal) 22.7cm ^3/100. After a polyurethane adhesive was applied to the PP film surface of the bonding material, a modified polyethylene film having a thickness of 40 μm was bonded by a dry lamination method.

[0026]

Comparative Example 3 PET film (50 μm thick)
m), after applying a polyurethane-based adhesive to one surface, dry lamination is used to obtain a layer having a thickness of 100 μm and a rigidity (vertical) of 7
6.4 bonded to one side coated paper (horizontal) 29.2cm ^3/100. After performing an anchor coat treatment on the PET film surface of the bonded material, a modified polyethylene film having a thickness of 40 μm was bonded as a sealant layer by a PE extrusion lamination method. The PE had a thickness of 15 μm after molding.

The one-side coated paper used in the above Examples and Comparative Examples was "Ryuocoat A" (manufactured by Nagoya Pulp Co., Ltd.) or "Cormorant Paper" (manufactured by Fuji Kako), and the PET film was "E5100". (Toyobo Co., Ltd.), EVOH film made by Kuraray Co., Ltd.,
The stretched PP film is “M-2” (manufactured by Tosero Corporation), and the modified polyethylene film is “VMX.”
(Mitsubishi Chemical Corporation), NY film was "Emblem ON" (Unitika), EVA resin was Tosoh Corporation, and EVA film was Tosoh Corporation.

Samples of 100 mm square were cut out from the laminated materials prepared in Examples and Comparative Examples, stored in an atmosphere at 5 ° C. and 10 ° C. for 24 hours, and immediately after being taken out, the degree of curl was examined. The curl amount is measured by the lifting distance from the smooth glass surface (the distance from the glass surface at the farthest point), and
After storage at 10 ° C. and 10 ° C., those having a thickness of 9 mm or less are judged as good (good), and those having a thickness of 10 mm or more are defective (bad)
And The results are shown in FIG. The stiffness of the paper is based on JIS P-8143 (Clark method).

[0029]

The laminated material of the present invention can be manufactured at a relatively low cost, and can be used in a stable state without curling due to a temperature difference. Also, since the aluminum foil conventionally used is not used, it can be easily incinerated. Furthermore, since the paper layer and the synthetic resin layer can be separated even when they are not incinerated, they are excellent in recyclability. In addition, since the laminated material of the present invention is formed on paper on one side, it has a minimum required unevenness on its surface, and also has an effect that it can be smoothly separated and supplied without blocking when stacked. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a laminated material of the present invention.

FIG. 2 is a table showing the results of Examples and Comparative Examples.

[Explanation of symbols]

 Reference Signs List 1 laminated material 2 paper 3 synthetic resin film layer 4 sealant layer

Continued on the front page F-term (reference) 4F100 AJ01A AK01B AK01C AK04C AK42B AK51G AK68C BA03 BA07 BA10A BA10C BA13 BA25A BA25B CC00A DG10A GB16 GB18 GB23 JA20A JA20B JA20C JK01A JL00 JL00 JL12Y

Claims (4)

[Claims] 1. A laminated material comprising (A) a layer mainly composed of paper having a thickness of 50 to 150 μm, (B) a layer made of a synthetic resin film alone or a composite, and (C) a sealant layer having a thickness of 15 to 50 μm. , (A), (B) and (C) the thickness of each layer has the following relationship packaging laminate. (A) ≧ (B) + (C) 2. A layer of paper mainly a single-sided coated paper, the stiffness of the vertical 20 to 100 ^3/100, horizontal 15
~80cm a ^3/100 claim 1 packaging laminate according. 3. A lid comprising the packaging laminate according to claim 1. 4. A pouch comprising the laminate for packaging according to claim 1.