JP2000255620A - Heat sealing lid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of curls, and to improve the separation of paper sheets from each other by using a heat adhesive synthetic resin film provided with recessed/projecting patterns before lamination as the heat adhesive resin layer in a lid member comprising at least two laminates having the heat adhesive resin layer. SOLUTION: A heat sealable lid member 1 is formed by laminating a base material 2 and a heat adhesive resin layer 3. The heat adhesive resin layer 3 is provided with recessed/projecting patterns 3a in advance before lamination. The base material 2 includes laminates of an exterior resin film, an aluminum foil, and a reinforced resin film. A sealant film of 15-100 μm in thickness consisting of a poly-acrylate, a styrene butadiene ethylene block copolymer, etc., can be adopted for the heat adhesive resin layer 3, but the sealant film is surely provided with the recessed/projecting patterns such as embossing before lamination. The patterning may be arbitrary, but the depth of the patterns is about 1-100 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lid material for packaging containers of foods, beverages, pharmaceuticals, quasi-drugs, electronic parts, etc., and more particularly to a heat sealing lid material suitable for an automatic single-sheet feeding system.

[0002]

2. Description of the Related Art Conventionally, in order to improve the suitability of separating a lid material one by one, a method of embossing after laminating materials, and a method of extruding a heat-adhesive resin layer with a resin by laminating a cooling roll. Although the method of molding using a roll having an uneven surface has been adopted, depending on the lamination structure, due to the elasticity and elongation difference of each layer, curling occurs due to molding or curl due to heat history at the time of extrusion. In some cases, the supply of the lid material often caused a failure due to curling.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat-sealing lid material which does not cause curl and has good sheet-to-sheet separability.

[0004]

In order to solve the above-mentioned problems, the present invention relates to a lid material comprising a laminate of two or more layers having a heat-adhesive resin layer, wherein the heat-adhesive resin layer is formed by embossing irregularities before lamination. Is used. As described above, by performing the molding in advance, it is possible to prevent the occurrence of curl due to the heat history at the time of extruding the resin, and to improve the sheet-to-sheet separation property due to the unevenness.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, a heat sealing material 1 according to the present invention is obtained by laminating a base material 2 and a thermo-adhesive resin layer 3, and the thermo-adhesive resin layer 3 has irregularities before lamination. 3a is typed. The base material 2 is a synthetic resin,
Any one of a simple substance such as a metal foil and paper or a composite may be used. For example, a laminate of an exterior resin film 21, an aluminum foil 22a, and a reinforcing resin film 23 as shown in FIG. 2, an exterior resin film 21 as shown in FIG. , A laminate of a metal or inorganic oxide deposited layer 22b and a reinforcing resin film 23, FIG.
The laminated body of the paper 24 and the reinforcing resin film 23 as shown in FIG.

As the exterior resin film 21, polyester (PET), polypropylene (PP), nylon (NY), cellophane, or the like can be used, and usually a thickness of about 5 to 50 μm is preferable. Aluminum foil 22a
As pure aluminum (JIS 1000 system), A
l-Mn type (3000 type), Al-Mg type (500 type)
0-type), Al-Fe (8000-type), and the like, and usually a thickness of about 5 to 50 μm is preferable. Reinforced resin film 23
As for the exterior resin film, PET, PP,
NY, polyethylene (PE), polyvinyl chloride (PV
C) and an ethylene-vinyl alcohol copolymer (E
VOH) can be used. The preferred thickness of the reinforcing resin film 23 is about 5 to 100 μm. When the paper 24 is used, coated paper, Japanese paper, kraft paper, pure white roll paper, woodfree paper, recycled paper, imitation paper, etc. can be used, and the thickness is 20.
About 150 μm is preferable. When the vapor deposition layer 22b is employed, for example, 300 to 12
Aluminum deposited with a thickness of 00 Angstroms,
Examples thereof include alumina and silicon oxide. The synthetic resin film may be an exterior resin film 21 or a reinforcing resin film 2
3 may be used.

The thermal adhesive resin layer 3 includes polyacrylate, styrene-butadiene-ethylene block copolymer, acryl-nitrile (AN), PE, PP, vinyl chloride-vinyl acetate-maleic acid terpolymer, Ethylene-vinyl acetate (EVA), methyl methacrylate,
15 to 100 μm thick made of polystyrene (PS) etc.
Some degree of sealant film can be employed. The sealant film needs to be embossed or the like before embossing, and can be embossed by, for example, an embossing roll. Further, when forming the sealant film, irregularities can be provided during the film forming process by using a roll or the like having irregularities on the surface.
As the pattern of the roll, for example, a known pattern such as a satin pattern or a silk pattern can be adopted. However, the pattern is not limited to this, and an arbitrary designed pattern can be adopted. The depth of the mold is preferably about 1 to 100 μm,
When the thickness is less than 1 μm, the effect of the molding is poor, and the effect of preventing blocking and curling cannot be expected. On the other hand, if the thickness exceeds 100 μm, further improvement in performance cannot be expected, and pinholes and cracks are likely to occur.

A known method can be used for laminating the respective layers constituting the lid member 1. For example, dry lamination using a two-component reactive polyester-based or two-component reactive polyester-polyurethane-based adhesive, solvent-based adhesion, or the like. It can be laminated by a method such as wet lamination using an agent.
In addition, the print layer and the anchor coat layer (A
C), an overcoat layer or the like may be formed.
The total thickness of the lid material 1 is preferably 30 to 200 μm. If the total thickness is less than 30 μm, the rigidity (rigidity) of the lid material is not sufficient, and the automatic supply aptitude is lacking, and breakage or cracking may occur during distribution of the package. Is not preferred. On the other hand, if the total thickness exceeds 200 μm, the flexibility as the lid material is poor, and the easy-opening property may be impaired, which is not economically preferable.

Examples and comparative examples will be described below.

[0010]

EXAMPLE A laminate having the following structure was produced by a conventional method.
Numbers without units indicate the thickness of the layer (unit μ
m). D is dry lamination, AL is aluminum foil (JIS 1N30 soft foil), PPE is a blend film of PE and PP (manufactured by Toyo Aluminum Co., Ltd.), and other abbreviations are described in the above text. In the examples of (1) to (6), all the sealant films are preliminarily formed with # 200 silk or # 120 silk.

(1) 12PET / D / 35AL / AC / 15PE / 30 modified EVA
Film (pre-molded # 200 silk) (2) 12PET / D / 35AL / AC / 15PE / 30 modified EVA film (pre-molded # 120 silk) (3) 25PET / D / 15AL / D / 30PPE film (pre-molded # 20
(4) 25PET / D / 15AL / D / 30PPE film (pre-molding # 12
0 silky) (5) 64g / m ² coated paper / D / 12PET / AC / 25PE / 30 modified EVA film (pre-typed # 200 silky) (6) 64g / m ² coated paper / D / 12PET / AC / 25PE / 30 modified EVA film (pre-molded # 120 silk).

[0012]

[Comparative Example] (7) After laminating each layer with the same configuration as in Example (1),
The entire laminate was subjected to # 120 silk patterning. (8) Same configuration as in Example (1), with no molding. (9) After laminating each layer with the same configuration as in Example (3), the entire laminate was subjected to # 120 silk patterning. (10) Same configuration as in Example (3), with no molding.

The following evaluations were made for the above Examples and Comparative Examples. FIG. 6 shows the results.

[Appropriateness of Separation] A lid material (diameter: about 90 mm) with a grip portion (tab) shown in FIG. 5 was punched from each laminate. One hundred lids were stacked, sandwiched between flat glass plates, weighed so that a pressure of about 1 kg / cm ² was applied to the lids, and left on a horizontal desk for 24 hours. 24
After a lapse of time, the lid material is taken out and automatically sucked using a rubber suction cup, and a material in which 100 sheets of each leaf material are separated smoothly is good (O), and at least two lid materials are in close contact. ,
Those which had to be separated by hand were evaluated as defective (x).

[Curl Property] A 150 mm square specimen was cut out from each laminate, and the degree of curl was evaluated by a 100 mm length cross cut method. Judgment was made when the lifting distance from the plane was within 5 mm (good), and when the lifting distance was more than 5 mm (bad). Here, the cross-cut method means that a double-sided tape is coated on a smooth glass surface with an inner side of 100 mm.
A 100 mm square, paste the specimen on top of it so that the heat bonding resin layer side is the upper or lower surface, and cut it diagonally with a cutter knife so as to form an X-shape. The maximum height (distance) separated (floating) from above is measured from the side. This test was performed on both sides of the test piece, and the larger value was adopted and evaluated.

[0016]

According to the present invention, as described above, the thermal bonding resin layer of the lid member is laminated using the synthetic resin film on which concavities and convexities have been formed in advance, so that no new forming is performed, and A heat-sealing lid material which is not affected by the heat history at the time of resin extrusion and has a curl-free flat lid material and excellent separability is obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a lid material of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a base material of a lid member.

FIG. 3 is a cross-sectional view showing another example of the base material.

FIG. 4 is a sectional view showing still another example of the base material.

FIG. 5 is a plan view showing lid materials of Examples and Comparative Examples.

FIG. 6 is a table showing test results of Examples and Comparative Examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cover material 2 Base material 3 Thermal adhesive resin layer 3a Irregularities 21 Exterior resin film 22a Aluminum foil 22b Metal or inorganic oxide vapor deposition layer 23 Reinforcement resin film 24 Paper

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E067 AA11 AB01 AB26 AB41 AB81 BB01A BB12A BB14A BB16A BC07A EA06 EA35 EA36 EA37 EB27 EE38 FC01 3E084 BA06 BA07 BA08 BA09 CA01 CC01 CC02 CC03 CC07 CC08 FA09 GB01 HA08 4F100 AJ05A AK01B AK04B AK04J AK07A AK07B AK12B AK12J AK15B AK22B AK22J AK24B AK24J AK25B AK27B AK29B AK29J AK42A AK48A AK68B AK80B AL02B AT01AGB02B01A01 GB02A

Claims (1)

[Claims] 1. A heat-sealing lid material comprising a laminate of two or more layers having a heat-adhesive resin layer, wherein the heat-adhesive resin layer is formed of a heat-adhesive synthetic resin film on which concavities and convexities have been formed before lamination. A heat-sealing lid material,