JP2002144473A - Packaging material using aluminum foil and paper container using packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging material good in work efficiency or yield, using cardboard as a base material, having a heat-sealable thermoplastic resin layer as an inner layer and having an Al foil provided adjacent to the thermoplastic resin layer between the cardboard and the thermoplastic resin layer. SOLUTION: In the packaging material (10) using cardboard (11) as the base material, having the heat-sealable thermoplastic resin layer (12) as the innermost layer and having the Al foil (13) inside the thermoplastic resin layer, the Al foil is a degreased Al foil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging material using aluminum foil and a paper container using the packaging material. More particularly, the invention relates to a packaging material using degreased aluminum foil and a paper container using the packaging material. For containers.

[0002]

2. Description of the Related Art Conventionally, a packaging material comprising a paperboard as a base material, a heat-sealable thermoplastic resin layer as an innermost layer, and an aluminum (Al) foil inside the layer is, for example, paperboard / low-density. Polyethylene (LDPE) resin / Al
It is widely used as a packaging material having a multilayer structure such as foil / ethylene-methacrylic acid copolymer (EMAA) resin / LDPE resin.

However, in this configuration, Al
The foil is made of soft aluminum foil. Inside the Al foil, an acid copolymer resin such as EMAA resin or ethylene-acrylic acid copolymer (EAA) resin is used to maintain the adhesive strength with the Al foil. Needed to use. For this reason, it is basically a packaging material having a five-layer structure, and requires two steps (two passes) of processing. The resin yield and work efficiency are higher than those of a packaging material that can be worked in one step (one pass). It was inferior in point.

[0004]

SUMMARY OF THE INVENTION The present invention provides a heat-sealable thermoplastic resin layer on the innermost layer based on paperboard.
On the inside, it is made by paying attention to the above problems related to the packaging material provided with the Al foil, and is a thermoplastic resin layer that can be heat-sealed to the inner layer using paperboard as a base material with good work efficiency and yield. It is another object of the present invention to provide a packaging material provided with an Al foil adjacent to a thermoplastic resin layer between a paperboard and a thermoplastic resin layer, and a paper container using the packaging material.

[0005]

According to the first aspect of the present invention, there is provided a packaging material comprising a paperboard as a base material, a heat-sealable thermoplastic resin layer as an innermost layer, and an Al foil inside thereof. A packaging material using an Al foil, wherein the Al foil is a degreased Al foil.

As described above, since the degreased aluminum foil is used for the Al foil, the adhesiveness to a thermoplastic resin such as an LDPE resin does not vary, and a stable adhesive strength can be obtained. The degreased aluminum foil is obtained by heat-treating (annealing) the oils and fats used in the Al foil stretching step to activate the surface of the Al foil, and the wettability is a contact angle of 30 ° or less with pure water. is there. Usually, Al foil is generally heat-treated in a state of a coil having a wide width. However, since the degreased Al foil is heat-treated in a slit state, the wetting number is good and variation can be suppressed.

The invention according to claim 2 is the invention according to claim 1, wherein the innermost thermoplastic resin is bonded to the degreased Al foil at a processing temperature of 300 ° C. or more. This is the packaging material used.

As described above, the thermoplastic resin of the innermost layer is 3
Since it is bonded to the degreased Al foil at a processing temperature of 00 ° C. or more, the adhesiveness between the thermoplastic resin and the degreased Al foil is excellent without using an adhesion auxiliary agent such as an anchor coat agent.

[0009] The invention of claim 3 is based on claim 1 or 2.
It is a paper container produced using the packaging material described.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A packaging material using the aluminum foil of the present invention and a paper container using the packaging material will be described in detail below based on one embodiment.

FIG. 1 is an explanatory sectional view showing one embodiment of a packaging material using the aluminum foil of the present invention, and FIG.
FIG. 2 is a perspective explanatory view showing one embodiment of a paper container manufactured using the packaging material of FIG. 1.

As shown in FIG. 1, the packaging material using the aluminum foil of the present invention is made of a paperboard (11) as a base material and a heat-sealable thermoplastic resin layer (1) as an innermost layer.
2), and a packaging material (10) provided with an aluminum foil (13) inside thereof.

As the paperboard (11), single-sided coated cup base paper, card paper and the like can be mentioned, but finally, the type of paperboard can be selected optimally according to the form of the paper container to be formed. However, if necessary, an ink layer (not shown) or an overcoat varnish layer (not shown) can be provided on the surface. In this case, use a paperboard having a coated layer on the surface. This is preferable from the viewpoint of the printing effect and the like.

The thermoplastic resin layer (12) is a layer used as the innermost layer of the packaging material of the present invention, and is heat sealable.
LDPE resin and linear low density polyethylene (LLDPE)
Resins and polyolefin resins such as polypropylene (PP) resins can be preferably used.

The Al foil (13) located inside the thermoplastic resin layer is a layer for maintaining the barrier properties of the packaging material.
The oils and fats used in the foil stretching process are heat-treated (annealed) to A
1. Use a degreased Al foil with activated foil surface. For the wettability, a material having a contact angle of 30 ° or less with pure water is used.

A thermoplastic resin layer (12) and an Al foil (13)
Adhesion with an aluminum foil may be performed by a usual extrusion lamination method in which a thermoplastic resin is melted and extruded. The extrusion coating is performed at a melting temperature of 300 ° C. or more, so that an anchor coat which is an adhesion auxiliary agent is applied to the Al foil. It can be directly bonded to the Al foil without using an agent or the like.

The adhesion between the paperboard (11) and the Al foil (13) is
It may be performed by a usual extrusion lamination method in which a thermoplastic resin is melted and extruded, and a packaging material using the aluminum foil of the present invention can be produced in one step (one pass) by using a tandem extruder. it can.

The packaging material produced in this manner is processed into a desired form such as a paper cup, a paper tray, a paper box, etc., to obtain a paper container (20) of the present invention (see FIG. 2).

[0019]

The present invention will be described in detail with reference to the following examples. <Example 1> First, a single-sided coated cup base paper having a basis weight of 260 g / m ² was used as a paperboard, a single-side matte soft Al foil having a thickness of 7 µm was used as an Al foil, a degreased product (degreased S product, manufactured by Showa Aluminum Co., Ltd.), Mirason 16P which is an LDPE resin as a thermoplastic resin (density: 0.923 g / cm ³ , M
FR: 3.7 g / 10 min. , Manufactured by Mitsui Chemicals, Inc.)
Were prepared respectively.

Using a tandem type extruder, the first die is used to uncoated the single-side coated cup base paper and the single-sided matte soft A
1) While the corona discharge treatment is applied to the non-coated surface of the one-side coated cup base paper while facing the glossy surface of the foil, the thickness is 30 μm.
(Extruding temperature: 32) by extrusion lamination through LDPE resin (Mirason 16P)
(0 ° C.), and then the same LDPE resin (Mirason 16P) was extruded with a second die onto the non-glossy surface of the single-side matte soft Al foil at a thickness of 30 μm (extrusion temperature: 320 ° C.), Coating surface) cup base paper (260g
/ M ² ) / Corona discharge treatment / LDPE resin (30 μm)
/ Al foil, degreased S product (7μm) / LDPE resin (30μ
m) The packaging material of Example 1 having a four-layer configuration was processed in one pass.

Comparative Example 1 First, a paperboard having a basis weight of 260
g / m ² single-sided coated cup base paper, a 7-μm-thick single-sided matte soft Al foil as an Al foil, and Mirason 16P which is an LDPE resin as a thermoplastic resin (density: 0.923
g / cm ³ , MFR: 3.7 g / 10 min. Manufactured by Mitsui Chemicals, Inc.)
8C (manufactured by Mitsui Chemicals, Inc.) was prepared.

The uncoated side of the single-sided coated cup base paper and the glossy side of the single-sided matte soft Al foil are opposed to each other, and are bonded together by extrusion lamination via an LDPE resin.
(Coated side) Cup base paper (260 g / m ² ) / LDPE
A composite paper of resin (22 μm) / Al foil (7 μm) was produced.

Then, using a tandem type extruder, EMAA resin was 17 μm thick on the Al foil surface of the composite paper with a first die.
And a second die is used to apply an LDPE resin on the EMAA resin layer to a thickness of 17 μm. (Coated surface) Cup base paper (260 g / m ² ) / LDPE resin (22 μm) / Al Foil (7 μm) / EMAA resin (17
μm) / LDPE resin (17 μm) in five layers to prepare a packaging material of Comparative Example 1 in two passes.

The lamination strength and oil resistance of the two types of packaging materials thus produced were measured and observed by the following methods, and a paper cup, which is a representative of a paper container, was prepared using the two types of packaging materials. Using a conventional paper cup molding machine, paper cup moldability, cup sealability, and openability were measured and observed by the following methods. Table 1 shows the results. Laminate strength ‥ In Example 1, Al foil and inner layer LDPE
The strength of the resin layer, and the strength of the Al foil and the inner EMAA resin layer in Comparative Example 1, were measured by using a constant-speed elongation type tensile tester.
mm / min. The peel strength when peeled at an angle of 180 ° is measured at a speed of, the unit is N / 15mm width. Oil resistance ‥ Make a three-side seal bag with the LDPE resin surface of two kinds of packaging materials inside, and add 30ml of salad oil.
After the injection, the unsealed portion is sealed to form a four-sided sealed bag.
0 ° C., 90% RH. After storage for one month under the conditions of Example 1, the strength of the Al foil and the inner LDPE resin layer in Comparative Example 1
In the test, the strength of the Al foil and the inner EMAA resin layer was measured at 300 mm / min. The peel strength at the time of peeling at an angle of 180 ° was measured and compared with the strength before injecting the salad oil. Cup moldability ‥ Put a 2% aqueous solution of surfactant in the formed paper cup, leave it for 30 minutes, and observe the leakage and bleeding of the surfactant solution from the side seal part and bottom seal part of the paper cup. ○ な し No problem (no leakage, no bleeding) × あ り Problem (leakage, bleeding occurred) Cup sealability に Cover material on paper cup (single art paper (79g
/ M ² ) / LDPE (15 μm) / Al foil (7 μm) /
EMAA resin (20 μm) / hot melt adhesive (23
g / m ² ) and heat-sealed with a cup sealer to observe the cup sealability. : No problem ×: There was a problem Openability ‥ Open the heat-sealed cup with a cup sealer and visually observe the peeled state. ○: No problem ×: Problem

[0025]

[Table 1]

From the results, it can be seen that Example 1 has no quality problem compared to Comparative Example 1 which is a conventional product.

[0027]

As described above, the packaging material using the aluminum foil of the present invention and the paper container produced by using the packaging material are not inferior in quality to the conventional one, and the processing efficiency is improved. It can be seen that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of a packaging material using an aluminum foil of the present invention.

FIG. 2 is a perspective explanatory view showing one embodiment of a paper container manufactured using the packaging material of FIG. 1, wherein (a) is a paper cup,
(B) shows a paper tray and (c) shows a paper box.

[Explanation of symbols]

 10 packaging material 11 paperboard 12 thermoplastic resin layer 13 aluminum foil 20 paper container

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E060 AA03 AB03 AB12 BA04 BC01 BC04 DA25 3E086 AB01 AD02 AD05 AD06 BA13 BA15 BB51 BB74 CA01 CA11 4F100 AB10C AB33C AK01B AK06B BA03 BA07 BA10A BA10B DA01 DG10A EH16B12 GB16 J12 GB06

Claims (3)

[Claims] 1. A packaging material comprising a paperboard as a base material and a heat-sealable thermoplastic resin layer as an innermost layer and an aluminum foil inside thereof, wherein the aluminum foil is a degreased aluminum foil. Packaging material using aluminum foil. 2. The thermoplastic resin of the innermost layer has a temperature of 300 ° C.
The packaging material using an aluminum foil according to claim 1, wherein the packaging material is adhered to a degreased aluminum foil at the above processing temperature. 3. A paper container produced by using the packaging material according to claim 1.