JPH11171205A - Easy-to-unseal packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a bag to be easily unsealed with hands by positioning two kinds of laminate films comprising at least three layers to be innermost in a non-oriented polyolefin resin film bag and applying heat seal so that a heat-sealing line of a specific width is positioned at a rim of an outer periphery of the bag. SOLUTION: High-pressure-processed low density polyethylene is extruded into a film between a biaxially oriented polystyrene containing resin film with imine containing anchor coat agent applied and an aluminum foil, and after they are sand-laminated, the high-pressure-processed low density polyethylene is extruded into a film to form a heat-sealing layer to obtain an aluminum laminate. Then the high-pressure-processed low density polyethylene is extruded into a film on the biaxially oriented polystyrene containing resin film of the laminate film which has been aged to form a heat-sealing layer to obtain a polyvinylidene chloride film laminate. The two kinds of laminates are joined to provide a four-side-sealed bag having a heat-sealing line 2 of a width of 3 to 10 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging bag for packaging articles such as medicines and foods in small quantities.

[0002]

2. Description of the Related Art In packaging bags for packaging small quantities of articles such as pharmaceuticals and foods, the effect of being easily opened by hand without making a cut at the tearing point or applying special processing to the outer edge. As a packaging bag with
No. 71783 discloses a laminated film of a biaxially stretched polystyrene film having a thickness of 10 to 60 μm and a heat-sealable unstretched polyolefin film having a thickness of 10 to 80 μm. Easy-to-open packaging for packaging, in which the unstretched polyolefin film is positioned so that it is inside the bag, and heat-sealed so that a heat-sealing line having a width of 3 to 10 mm is positioned on the outer edge of the bag. A technique relating to a bag for packaging is disclosed.

[0003]

However, although a packaging bag that can be easily opened is obtained according to Japanese Patent Publication No. 4-71783, the gas barrier properties of oxygen and water vapor are low, and moisture absorption, deterioration, discoloration, Storage stability such as fragrance retention is not sufficient. On the other hand, in order to improve gas barrier properties, a biaxially stretched polyethylene terephthalate film (P
ET) There is a method of laminating a biaxially stretched nylon film (ONy) on which aluminum is vapor-deposited, or a film on which a silicon or aluminum oxide film is formed on a PET film. It is difficult to open.

[0004]

DISCLOSURE OF THE INVENTION The present invention has an effect that it can be easily opened by hand without making a cut at a tearing place in advance or applying special processing to an outer edge portion. An object of the present invention is to provide a packaging bag which is excellent in storage stability, transparency, decorativeness and design.

[0005]

Means for Solving the Problems The present inventor has made intensive studies to achieve the above object, and as a result, has accomplished the present invention. That is, the present invention provides a biaxially oriented polystyrene resin film having a thickness of 10 to 60 microns and a thickness of 10 to 8
A laminated film (A) having at least three layers in which an aluminum foil having a thickness of 3 to 70 μm is disposed between an unstretched polyolefin resin film of 0 μm and a 10 to 10 μm thick
60 micron biaxially oriented polystyrene resin film,
A laminated film (B) comprising at least three layers of an unstretched polyolefin-based resin film having a thickness of 10 to 80 μm and a polyvinylidene chloride-based resin film having a thickness of 1 to 30 μm, An easily openable packaging bag characterized by being positioned so as to be located on the innermost side of the bag, and heat-sealed so that a heat-sealing line having a width of 3 to 10 mm is located on an outer peripheral edge of the bag. .

Hereinafter, the present invention will be described. The most different point of the present invention from the prior art is that a packaging bag obtained by heat sealing a laminated film of a biaxially oriented polystyrene-based resin film and an unstretched polyolefin-based resin film can be combined with a biaxially oriented polystyrene-based resin film. A laminated film (A) in which an aluminum foil having a thickness of 3 to 70 microns is disposed between stretched polyolefin resin films, and a biaxially stretched polystyrene resin film having a thickness of 1 to 1 on at least one surface.
(A) and (B) of the laminate (B) in which the polyvinylidene chloride film of 30 μm is laminated are heat-sealed. The role of the constituent elements of the present invention, which is different from the above-mentioned prior art, is excellent in storage stability of contents, transparency, decorativeness and design while maintaining the effect of being easily opened by hand. That is, a packaging bag is obtained.

The aluminum foil used in the present invention is JIS4
1N30 in the indicated class of aluminum and aluminum alloy foils by 160 is preferred. Aluminum foil is roughly classified into hard foil and soft foil. When using soft foil, it is necessary to consider the rolling oil remaining on the surface. The thickness of the aluminum foil is 3 to 70 in consideration of gas barrier properties and tearing properties.
Microns, but preferably between 5 and 50 microns. If the thickness is less than 3 microns, the gas barrier properties are insufficient. If the thickness is more than 70 microns, the tearing property is greatly reduced, and it cannot be easily opened by hand.

In order to increase the adhesiveness between the biaxially oriented polystyrene resin film and the unstretched polyolefin resin film, it is preferable to apply an urethane-based, imine-based, butadiene-based anchor coating agent to the aluminum foil. . The polyvinylidene chloride resin film used in the present invention is a film containing a vinylidene chloride component in an amount of 70 to 97% by weight, preferably 80 to 96% by weight. 70
When the amount is less than 97% by weight, high crystallization proceeds and a film cannot be formed. Components other than vinylidene chloride include methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid, (meth) acrylonitrile,
There are vinyl chloride, styrene and the like, and may further contain a heat stabilizer, an ultraviolet absorber, an antioxidant, a coloring agent, a plasticizer, an oligomer, and other conventional additives as long as the object of the present invention is not impaired. it can.

[0009] The thickness of the polyvinylidene chloride resin film is 1 to 50 microns, preferably 2 to 40 microns. If it is less than 1 micron, the gas barrier properties are not sufficient, and if it is more than 50 microns, the tearing property decreases. Lamination of a polyvinylidene chloride resin film can be performed by a wet lamination method, a dry lamination method, a hot melt lamination method, a solventless lamination method, an extrusion lamination method, a method in which a polyvinylidene chloride resin is dissolved in an organic solvent, There is a method of coating a vinylidene resin latex on a biaxially stretched polystyrene resin film. Among them, a method of laminating a biaxially stretched polystyrene resin film and a polyvinylidene chloride resin film in terms of workability, uniformity of the vinylidene chloride resin layer, and solvent resistance of the polystyrene resin film, and a method of bonding the polyvinylidene chloride resin. A method of coating latex on a biaxially oriented polystyrene resin film is preferred. In the case of laminating a polyvinylidene chloride-based resin film, when laminating a film-like one, the film surface can be hydrophilized by a discharge treatment or an anchor coating agent can be applied in order to increase the adhesive force at the time of lamination.

The polystyrene resin film used in the present invention is a film made of a styrene polymer,
A biaxially stretched film is required because the bag can be easily torn open in any direction both longitudinally and laterally, and is a film having a sufficient orientation. Generally, general-purpose polystyrene (GPP) is used as the polystyrene resin.
S) is used, but in order to increase the impact strength, 1 to 30
% Of styrene-butadiene block copolymer, 0.1 to 20% by weight of impact-resistant polystyrene to give a degree of haze, and 0.1 to 1% by weight to improve slipperiness. Organic and inorganic particles may be added. The biaxially oriented polystyrene resin film used in the present invention can be obtained by biaxially stretching the above resin by an inflation method or a tenter method. In addition to the above, a mixture of a release agent, a heat stabilizer, an ultraviolet absorber, an antioxidant, a coloring agent, a plasticizer, an oligomer, and other conventional additives, as long as the characteristics of the present invention are not impaired, may be used. Good.

The orientation of the biaxially stretched polystyrene resin film is represented by the heat shrinkage stress, but the heat shrinkage stress in the biaxial direction is 1 kg / cm ² from the viewpoint of tearability.
６０60 kg / cm ² , preferably 2 kg / cm ² ５０50
kg / cm ² . If it is less than 1 kg / cm ² , the tearability is poor because the orientation of the film is not sufficient, and the film cannot be easily opened by tearing by hand. 60kg / cm
Those larger than ² require a complicated process for producing a biaxially oriented polystyrene film. The thickness of the biaxially oriented polystyrene film is 10 to 60 microns, preferably 15 to 60 microns.
~ 50 microns. If it is less than 10 microns, the film strength is not sufficient, and if it is more than 60 microns, the tearing property is reduced.

In order to increase the adhesiveness of the biaxially stretched polystyrene resin film at the time of lamination, it is preferable to hydrophilize the surface of the biaxially stretched polystyrene resin film by a discharge treatment or to apply an anchor coat agent. Anchor coating agents include urethane-based, imine-based, and butadiene-based anchor coating agents.Anchor coating agents used for biaxially-oriented polystyrene-based resin films include alcohol-based and aqueous-based solvents because the biaxially-oriented polystyrene film is attacked by the solvent. Is preferably used.

Further, the biaxially oriented polystyrene film may be attacked by a solvent or an additive contained in the dry lamination and the adhesive in some cases. For this reason, it is necessary to consider an adhesive mainly composed of an alcohol-based or water-based solvent, or to laminate the film after scattering the solvent to some extent. As the unstretched polyolefin-based resin film used as the heat seal layer in the present invention, a film of polyethylene, polypropylene or a copolymer mainly composed of these is used. A release agent, a heat stabilizer, an antioxidant, a colorant, a plasticizer, an oligomer, other conventional additives, and the like may be mixed with these as long as the characteristics of the present invention are not impaired.

Further, in order to eliminate wrinkles generated during heat sealing, an unstretched polyolefin resin film having a melting point of 70 to 105 ° C. by a DSC method can be used for a package whose appearance is particularly important. 70-105 ° C melting point
Examples of the polyolefin film include ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic ester copolymer, ionic crosslinked product of acid copolymer (ionomer), ethylene and α-olefin polymerized using SSC Is appropriately selected from copolymers with
There are films consisting of simple or mixed compositions.

The thickness of the unstretched polyolefin resin film is from 10 to 80 μm, preferably from 10 to 60 μm, based on the tearing property and the heat sealing strength.
If it is less than 10 microns, the heat seal strength is not sufficient, and if it is more than 80 microns, the tearing property is greatly reduced. Lamination of the unstretched polyolefin resin film is performed by a wet lamination method, a dry lamination method,
Hot melt lamination method, solventless lamination method,
There is an extrusion lamination method. When laminating a film-shaped unstretched polyolefin-based resin film, the surface of the film may be subjected to a hydrophilization treatment by electric discharge machining and an anchor coat agent may be applied in order to increase the adhesiveness.

In order to increase the adhesiveness in the extrusion laminating method, the temperature immediately under the die is increased as much as possible during the extrusion to oxidize the surface of the molten resin extruded into a film, or after extruding the film into a film, the film surface is subjected to ozone treatment. Hydrophilic treatment can be performed. Polyolefin resins which cannot be extruded at high temperatures due to neck-in or thermal decomposition can be subjected to double lamination or tandem lamination in which high-pressure low-density polyethylene is extruded and laminated at high temperature in advance.

When there is an obstacle due to static electricity at the time of filling and packaging in powdered pharmaceutical products, food powder soups, etc., an antistatic agent is kneaded into a biaxially oriented polystyrene resin film or an unoriented polyolefin resin film, An antistatic treatment such as applying an antistatic agent to the film surface can be performed. The biaxially stretched polystyrene resin film, aluminum foil, and unstretched polyolefin resin film to be used can be subjected to various printings.

The bag of the present invention is obtained by heat-sealing the laminated film (A) and the laminated film (B). When a laminated film having an aluminum foil having a thickness of 3 to 70 microns is heat-sealed between a biaxially stretched polystyrene resin film and a heat-sealing unstretched polyolefin resin film, gas barrier properties and light blocking properties are high. In addition, the aluminum foil is excellent in decorativeness and design due to the metallic luster of the aluminum foil, but has a problem that the content cannot be confirmed due to lack of transparency, and may not be sufficient depending on the use. When heat-sealing laminated films having a biaxially oriented polystyrene resin film, a polyvinylidene chloride resin film having a thickness of 1 to 30 microns, and an unstretched polyolefin resin film, the gas barrier property is high, and the film is transparent. Although it has excellent properties, it has problems such as low decorativeness and designability, and may not be sufficient depending on the use. The present invention heat seals the laminated film (A) and the laminated film (B) so as not to impair the effects of both laminated films and to maintain gas tearing property, transparency while maintaining tear openability. It succeeded in providing a bag excellent in decorativeness and design.

The bag of the present invention comprises the above laminated film (A),
(B) is positioned such that the unstretched polyolefin-based resin film is located on the innermost side of the bag, and heat-sealed such that a heat-sealing line having a width of 3 to 10 mm is positioned on the outer peripheral edge of the bag. If the heat seal width is less than 3 mm,
The strength of the metal part is weak, the bag is easily broken, and if it exceeds 10 mm, the tearing property is reduced. As a method of heat sealing,
So-called three-way seals, four-way seals, and the like can be given. Examples of the form of the bag of the present invention include those shown in FIG. With the above configuration, the bag of the present invention can be easily opened by tearing by hand in a direction substantially perpendicular to the heat seal line.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to examples. The evaluation method in the present invention is as follows. (1) Heat Shrinkage Stress (ORS) According to ASTM-D1504, a peak stress value in a silicon hot water at a temperature of Vicat softening point temperature of a film + 30 ° C. was determined. (2) Melting point measurement (DSC) After weighing 8 to 10 mg of a sample, sealing the sample in an aluminum pan, and using a differential calorimeter (Model DSC-7 manufactured by PerkinElmer) in a 30 ml / min nitrogen stream from room temperature to 190 ° C. Raise the temperature and hold at this temperature for 30 minutes, then about 10 ° C /
Cool to room temperature in min. Thereafter, the temperature was raised at a rate of 10 ° C. /
Using the melting curve obtained in min, the main peak temperature is taken as the melting point. (3) Preparation of a packaging bag Under the following conditions, a prototype aluminum foil was laminated with the unstretched polyolefin film layers of the laminate (A) and the polyvinylidene chloride-based resin laminate (B), and heat-sealed.
A packaging bag having a width of 10 m and a width of 10 cm was prepared. -Equipment used: TP-701 manufactured by Tester Sangyo Co., Ltd.-Seal width: 7 mm-Seal temperature: 160 ° C-Seal time: 0.2 seconds-Seal pressure: 1 kg / cm ² (4) Gas barrier properties-Oxygen permeability Using OX-TRAN-200H100 manufactured by MOCON, it was measured at 23 ° C. and 65% RH according to ASTM-D3985. -Water vapor permeability Using PERMATRAN, W-200 manufactured by MOCON, measured at 38 ° C and 90% RH according to ASTM-F1249.

[0021]

Example 1 [Preparation of Aluminum Laminate (A-1)] As a biaxially stretched polystyrene resin film, "OPS film GM" (manufactured by Asahi Kasei Corporation) (thickness: 20 μm, vertical ORS: 15 kg / cm ²⁾ , Transverse ORS7k
g / cm ² ), and one surface was subjected to discharge treatment. The above-mentioned biaxially stretched polystyrene resin film subjected to the discharge treatment and an aluminum foil (“SA30” manufactured by Sumitomo Light Metal Co., Ltd., thickness 9)
Micron) on both sides of an imine-based anchor coat agent (“EL-420” manufactured by Toyo Morton Co., Ltd.) in a dry coating amount of 4
It was applied so as to be 0 mg / m ² and dried.

Next, a high-pressure method low-density polyethylene (“L2340” manufactured by Asahi Kasei Kogyo Co., Ltd., melting point 112) is placed between the biaxially stretched polystyrene resin film and the aluminum foil.
° C) directly under a die at a temperature of 320 ° C and a thickness of 15 µm into a film, extruding (sand) laminating a biaxially stretched polystyrene film and an aluminum foil, and then applying a high-pressure low-density polyethylene (manufactured by Asahi Chemical Industry Co., Ltd.).
"L2340", melting point 112 ° C)
An extruded heat seal layer was formed at a temperature of 30 ° C. and a thickness of 30 μm to obtain an aluminum laminate (A-1). The gas barrier properties of the obtained aluminum laminate (A-1) were evaluated. Table 1 shows the results. [Preparation of Polyvinylidene Chloride Film Laminate (B-1)] As a biaxially stretched polystyrene resin film, "OPS Film GM" manufactured by Asahi Kasei Corporation (thickness: 20 microns, vertical ORS: 15 kg / cm ² , horizontal) Direction ORS
7 kg / cm ² ), discharge treatment on both sides, and butadiene-based anchor coat agent (Toyo Morton Co., Ltd.) on both sides
"EL-451") in a dry coating amount of 40 mg / m ²
And dried. On one surface of the biaxial polystyrene resin film, a polyvinylidene chloride resin latex (“Saran Latex L54” manufactured by Asahi Kasei Corporation)
1A ", a vinylidene chloride component (91% by weight) was coated to a dry thickness of 5 μm, dried, and aged at room temperature for 1 day.

Next, on the biaxially stretched polystyrene resin film of the laminated film subjected to the aging treatment,
High-pressure low-density polyethylene (“L” manufactured by Asahi Kasei Corporation)
2340 ”, melting point 112 ° C.)
Extruded into a film with a thickness of 30 microns to form a heat seal layer, and then formed a polyvinylidene chloride film laminate (B-
1) was obtained. The gas barrier properties of the obtained polyvinylidene chloride film laminate (B-1) were evaluated. Table 1 shows the results. The transparency of the laminate was good, and as shown in Table 1, the gas barrier properties of the polyvinylidene chloride film laminate (B-1) were good. [Preparation of Packaging Bag] The two types of laminates (A-
The heat-sealing layers of 1) and (B-1) were combined together and heat-sealed at a sealing temperature of 160 ° C. to form a four-side seal bag. This bag can be easily opened by tearing by hand in a direction almost perpendicular to the heat seal line from any position of the heat seal line, the contents can be checked from the polyvinylidene chloride film laminate side, and aluminum metal Excellent in decorativeness and design due to gloss.

[0024]

Example 2 [Preparation of Aluminum Laminate (A-2)] As a biaxially stretched polystyrene resin film, "OPS film GM" (manufactured by Asahi Kasei Corporation) (thickness: 20 μm, vertical ORS: 15 kg / cm ²⁾ , Transverse ORS7k
g / cm ² ), and one surface was subjected to discharge treatment.

An aluminum foil (Sumitomo Light Metal Co., Ltd.) was used on the side of the biaxially stretched polystyrene resin film subjected to the discharge treatment, using "Seika Bond A-342, C-60" manufactured by Dainichi Seika Co., Ltd. (“SA30”, thickness 40 μm) was dry-laminated. Then, a non-stretched polypropylene film ("Pyren Film-CT", manufactured by Toyobo Co., Ltd., thickness: 25 microns, melting point: 138 [deg.] C.) was coated on a biaxially stretched polystyrene resin film of the laminated film manufactured by Dainichi Seika Co., Ltd. "Seikabond E-287, C-28"
Laminated using the aluminum laminate (A-2)
Was obtained, and the gas barrier properties of Seo were evaluated. Table 1 shows the results.
Shown in As shown in Table 1, the gas barrier properties of the aluminum laminate (A-2) were good. [Preparation of Polyvinylidene Chloride Film Laminate (B-2)] As a biaxially stretched polystyrene resin film, "OPS Film GM" manufactured by Asahi Chemical Industry Co., Ltd. (thickness: 20 microns, vertical ORS: 15 kg / cm ² , horizontal) Direction ORS
7 kg / cm ² ), discharge treatment on one side, and further use a butadiene anchor coating agent (manufactured by Toyo Morton Co., Ltd.)
Was applied and dried so that 40 mg / m ² on a dry coating amount of "EL-451").

Using "Seika Bond A-342, C-60" manufactured by Dainichi Seika Co., Ltd. as an adhesive, a polyvinylidene chloride-based resin film ( Asahi Kasei Kogyo Co., Ltd.
"Saran UB", 15 microns, vinylidene chloride component 9
5% by weight). Furthermore, an unstretched polypropylene film ("Pyren Film-CT" manufactured by Toyobo Co., Ltd.) is laminated on the laminated polyvinylidene chloride resin film.
A layer having a thickness of 25 microns and a melting point of 138 ° C.) is laminated using an adhesive (“Seika Bond E-287, C-28” manufactured by Dainichi Seika Co., Ltd.), and a polyvinylidene chloride resin laminate (B-
2) was obtained. The gas barrier properties of the obtained polyvinylidene chloride-based resin laminate (B-2) were evaluated. Table 1 shows the results. Polyvinylidene chloride resin laminate (B-2)
Was good in transparency and gas barrier properties were good as shown in Table 1. [Preparation of packaging bag] The obtained two types of laminates (A-2),
The heat seal layers of (B-2) were combined and heat sealed to form a four-side seal bag. This bag can be easily opened from any position on the heat seal line by tearing it by hand in a direction almost perpendicular to the heat seal line, the contents can be checked from the polyvinylidene chloride film laminated film, and the aluminum metallic luster It was also excellent in decorativeness and design.

[0027]

Example 3 The heat sealing layers of the aluminum laminate (A-1) of Example 1 and the polyvinylidene chloride laminate (B-2) of Example 2 were heat-sealed to form a four-side seal bag. . This bag can be easily opened from any position on the heat seal line by tearing it by hand in a direction substantially perpendicular to the heat seal line, the contents can be confirmed from the polyvinylidene chloride film laminated film, and the metallic luster of aluminum Excellent in decorativeness and design.

[0028]

Example 4 The aluminum laminate (A-2) of Example 2 and the heat seal layer of the polyvinylidene chloride laminate (B-1) of Example 1 were heat-sealed together to form a four-side seal bag. . This bag can be easily opened from any position on the heat-sealing line by tearing it by hand in a direction substantially perpendicular to the heat-sealing line, the contents can be checked from the polyvinylidene chloride resin laminated film, and the aluminum metal Excellent in decorativeness and design due to gloss.

[0029]

Comparative Example 1 Only the aluminum laminate (A-1) of Example 1 was used.
The heat seal layers were combined and heat sealed to form a four-sided seal bag. This bag can be easily opened from any position on the heat-sealing line by tearing it by hand in a direction substantially perpendicular to the heat-sealing line, and although the design is excellent due to the metallic luster of aluminum, the contents cannot be confirmed. Was something.

[0030]

Comparative Example 2 The polyvinylidene chloride laminate (B
Only in -1), the heat-sealing layers were combined and heat-sealed to form a four-side seal bag. This bag could be easily opened by tearing by hand in a direction substantially perpendicular to the heat seal line from an arbitrary position of the heat seal line, and was excellent in transparency but poor in design.

[0031]

[Table 1]

[0032]

The bag of the present invention has the effect that the bag can be easily torn straight and tear open in the intended direction without making a cut in the tearing area or applying special processing to the outer edge. In addition, it has high gas barrier properties, excellent preservability of contents, and excellent transparency, decorativeness and design. The above-mentioned effects are useful effects, for example, when packaging articles that require storage stability among pharmaceuticals, foods, and the like, in small quantities.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a packaging bag of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Packaging bag 2 Heat seal wire

Claims (1)

[Claims] An aluminum foil having a thickness of 3 to 70 microns is disposed between a biaxially oriented polystyrene resin film having a thickness of 10 to 60 microns and an unoriented polyolefin resin film having a thickness of 10 to 80 microns. A laminated film (A) having at least three layers, a biaxially oriented polystyrene resin film having a thickness of 10 to 60 microns, and a thickness of 10
And a laminated film (B) comprising at least three layers of an unstretched polyolefin-based resin film having a thickness of 1 to 30 microns and a polyvinylidene chloride-based resin film having a thickness of 1 to 30 microns. An easily openable packaging bag, which is positioned so as to be on the inside and heat-sealed so that a heat-sealing line having a width of 3 to 10 mm is positioned at an outer peripheral edge of the bag.