WO2004011252A1

WO2004011252A1 - Laminated packaging material and packaging bag

Info

Publication number: WO2004011252A1
Application number: PCT/JP2003/009456
Authority: WO
Inventors: Hiroyuki Mizuma; Toshiyuki Maki
Original assignee: Toppan Printing Co., Ltd.
Priority date: 2002-07-25
Filing date: 2003-07-25
Publication date: 2004-02-05
Also published as: JPWO2004011252A1; AU2003248113A1

Abstract

A laminated packaging material which comprises a substrate, an adhesive layer and a sealant comprising two laminated linear polyethylene layers having different densities, wherein the sealant comprises a first layer being located on the adhesive side and having a density of 0.89 to 0.925/cm3, and a second layer having a density of more than 0.925 /cm3 and not more than 0.940/cm3, and satisfies with respect to the thickness of the above layers that a/b is 3 to 5 and b is 5 to 20 μm, a and b representing the sickness of the first layer and second layer, respectively.

Description

Specification

Laminated packaging materials and packaging bags

Technical field

The present invention relates to a packaging bag that can be formed and sealed by heat sealing, and a heat-sealing-capable laminated packaging material used for the bag. Background art

In recent years, in the packaging field, with the filling of contents and the speeding up of packaging machines, the density of the low-temperature sealing, sealing strength, and bending resistance is excellent as the sealant layer of the laminated packaging material used. . 9 25 g / m 3 or less linear low-density polyethylene resin is widely used. However, when the linear low-density polyethylene resin was used as the sealant layer, physical properties such as piercing strength, slipperiness, and abrasion resistance were poor.

In order to improve the slipperiness and abrasion resistance, a sealant layer in which various slip agents are added to a linear low-density polyethylene resin is used. However, the slipping agent tends to precipitate on the surface of the sealant layer with the passage of time, and has a problem that, for example, it adversely affects contents such as pharmaceuticals.

In order to improve the piercing strength, slipperiness and abrasion resistance, it is possible to use a sealant layer made of linear medium-density polyethylene resin with a density exceeding 0.925 g / m3. it can. However, this linear medium-density polyethylene resin has drawbacks such as strong stiffness, low flex resistance, and poor pinhole resistance. Disclosure of the invention

The first object of the present invention is to provide piercing strength, slipperiness, wear resistance, It is intended to provide a laminated packaging material having excellent bending resistance and pinhole resistance.

A second object of the present invention is to provide a packaging bag excellent in piercing strength, slipperiness, abrasion resistance, bending resistance, and pinhole resistance.

The laminated packaging material of the present invention comprises: a base material comprising a single-layer film or a multilayer film;

An adhesive layer provided on one surface of the base material,

A laminated packaging material provided on the adhesive layer and comprising a two-layer laminated sealant layer,

The double-layered sealant layer is provided on the adhesive layer, and has a linear low-density of 0.79 g / cm ³ to 0.925 g / cm 3. Po re ethylene les down resin layer, and said linear low density provided Po Li ethylene Ren resin layer ◦. 9 2 5 g / c m3 good Ri rather large, 0. 9 4 O g Z cm 3 or less The linear low-density polyethylene resin layer having a density of a, wherein the thickness of the linear low-density polyethylene resin layer is a, and the linear medium-density polyethylene resin layer is When the thickness of the layer is b, the thickness ratio a / b is 3 to 5, and b is 5 to 20 μηι.

The packaging bag of the present invention comprises a base material made of a single-layer film or a multi-layer film, an adhesive layer provided on one surface of the base material, and a two-layer laminated seal provided on the adhesive layer. A packaging bag formed by heat-sealing with the sealant layer inside, comprising a laminated packaging material having

The double-layered sealant layer is provided on the adhesive layer. A linear low-density polyethylene resin layer having a density of 0.89 to 0.925 g / cm 3, and a linear low-density polyethylene resin layer provided on the linear low-density polyethylene resin layer. The linear low-density polyethylene resin layer is larger than 0.925 g Z cm 3 and has a density of 0.940 g / cm 3 or less. Assuming that the thickness of the polyethylene resin layer is a and the thickness of the linear medium-density polyethylene resin layer is b, the thickness ratio a Zb is 3 to 5, and b is characterized by being 5 to 20 ^ um.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side sectional view showing an example of the laminated packaging material of the present invention.

FIG. 2 is a front view illustrating an example of the packaging bag according to the present invention. FIG. 3 is a front view illustrating an example of a state in which the packaging bag according to the present invention is sealed. BEST MODE FOR CARRYING OUT THE INVENTION

The laminated packaging material of the present invention basically has a configuration in which an adhesive layer and a double-layered sealant layer are laminated on a base material.

The substrate comprises a single-layer film or a multi-layer film.

The adhesive layer is provided for bonding the base material and the two-layer laminated sealant layer.

The two-layer laminated sealant layer is composed of a linear low-density polyethylene resin layer and a linear medium-density polyethylene resin layer.

The linear low-density polyethylene resin layer used in the present invention is a linear polyethylene having a density of 0.89 to 0.925 g Z cm 3. Ethylene resin layer. The linear medium-density polyethylene resin layer used in the present invention has a density greater than 0.925 g / cm3 and a density of 0.940 g / cm3 or less. Refers to a linear polyethylene resin layer.

Furthermore, in the present invention, when the thickness of the linear low-density polyethylene resin layer is a and the thickness of the linear medium-density polyethylene resin layer is b, The ratio a / b is between 3 and 5, and b is between 5 and 20 μm.

The packaging bag of the present invention is formed by heat-sealing the laminated packaging material with the two-layered sealant layer inside.

According to the present invention, the sealant layer of the laminated packaging material is formed of a linear low-density polyethylene resin layer having a predetermined density and thickness and a linear medium-density polyolefin having a predetermined density and thickness. By forming a two-layer laminate with an ethylene resin layer, the piercing strength, sliding property, abrasion resistance, bending resistance, and pin resistance can be maintained without impairing the low-temperature sealing property and sealing strength. A laminated packaging material with excellent hole properties can be obtained. The package obtained using this laminated packaging material has sufficient low-temperature sealability and seal strength, and is excellent in piercing strength, slipperiness, abrasion resistance, bending resistance, and pinhole resistance. .

If the density of the linear polyethylene resin layer provided on the adhesive layer is less than 0.89 g / cm3, the slip property during film formation is poor and the amount of slip agent is small. In the case of (1), there are problems such as difficulty in winding up and elution of low molecular weight components, and the density of 0.925 g Z cm3 on the adhesive layer. Over The use of a linear polyethylene resin layer having a medium density or higher density has the disadvantage that the rigidity of the laminated packaging material becomes stronger overall and its bending resistance is reduced. There is.

In addition, when a linear polyethylene resin layer having a density of 0.925 g Z cm3 or less is provided on the linear low-density polyethylene resin layer, slipperiness is reduced, The suitability for bag making and filling as a packaging material is reduced, and if a linear polyethylene resin layer having a density greater than 0.940 g / cm3 is provided, the rigidity of the laminated packaging material will be reduced. It has the disadvantage that it becomes stronger overall and pinholes are generated due to bending fatigue.

If the ratio of the thickness of the linear low-density polyethylene resin layer to the linear medium-density polyethylene resin layer, a Z b, is less than 3, the overall bending resistance decreases. However, when ab exceeds 5, there is a disadvantage that the piercing strength as a whole decreases.

Further, if the thickness of the linear medium-density polyethylene is less than 5 μπι, there is a disadvantage that stable production on the film becomes difficult, and if it exceeds 20 111, The disadvantage is that the laminated packaging material becomes too stiff.

The thickness a of the linear low-density polyethylene resin layer is preferably 15 to 100 m, and if it is less than 15 μππι, the film-forming stability is poor. When the thickness exceeds 100 μιη, the total thickness of the sealant exceeds 12 Ο / m, and it tends to be unsuitable as a packaging material. .

The difference between the density of the linear low-density polyethylene resin layer and the density of the linear medium-density polyethylene resin layer is preferably 0.02. If it is 0.03 g Z cm3, and if it is less than 0.02 _{g /} cm3, the effect of laminating two layers of sealants having different densities, that is, the low-temperature sealing property and the sealing strength is impaired. Without this, the effect of improving the piercing strength, slipperiness, abrasion resistance, bending resistance, and pinhole resistance tends to be lost.

In addition, a slipping agent can be added to the linear low-density polyethylene resin layer for the purpose of improving slipperiness and abrasion resistance. The amount of addition is preferably as small as possible so that the adhesion, migration, or elution of the slip agent to the contents is suppressed as much as possible. Examples of the slipping agent include fatty acid amide (5302 M, manufactured by Ube Industries, Ltd.). The amount of the slipping agent is, for example, in linear low-density polyethylene resin. It is about 250 Ppm.

As the straight-chain polyethylene resin, AFFINITI POP manufactured by Dow Chemical Japan, Evoluyu manufactured by Mitsui Chemicals, and Umelite manufactured by Ube Industries, etc. can be used.

As the single-layer film used for the base material layer, for example, a biaxially stretched polypropylene film having a thickness of preferably 20 to 30 / zm, preferably 15 A biaxially stretched nylon film having a thickness of 225 m, preferably a biaxially stretched polyester film having a thickness of 6 to 12 μπι. When imparting gas barrier properties to the base material layer, it is preferable to use a metal having a thickness of 6 to 9 μm, for example, aluminum foil, or a gas barrier property with the single-layer film. A laminated film with a film can be used. Film with gas barrier properties For example, an aluminum vapor-deposited film having a thickness of preferably 6 to 30 μm, or a silicon oxide or aluminum oxide having a thickness of preferably 6 to 12 μππ A polyester film having a thickness of 6 to 15 μπι, preferably a biaxially stretched polyvinyl alcohol film having a thickness of 6 to 15 μπι, and a thickness of 6 to 20 μιη Ethylene / vinyl alcohol film etc., preferably having an oxygen permeability of 1

^{0 cm 3 / m2 / day /} MP a (3 0.C, 7 0%) is Der Ru off I Lum less used.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a side sectional view showing an example of the laminated packaging material of the present invention. This laminated packaging material 6 is composed of an adhesive layer 2 provided on one surface of a base layer 1 composed of a single-layer film or a laminated film, and a two-layer structure provided on the adhesive layer 2. It has 5 sealant layers. The sealant layer 5 has a linear low-density polyethylene resin layer 3 having a density of 0.89 to 0.925 g Zcm 3 on the side of the adhesive layer 2, the side in contact with the contents. A linear medium-density polyethylene resin layer 4 having a density larger than 0.925 gZcm3 and not more than 0.940 gZcm3 is provided.

The sealant layer 5 can be laminated by, for example, a known co-extrusion laminating method.

As the adhesive layer 2, for example, a two-component curing type polyurethane adhesive can be used. The adhesive layer 2 can be formed by, for example, a known Daravia method. The coating amount can be set to, for example, 1 to 5 g Zm ² in a dry state. The laminated packaging material can be further provided with, for example, a printed layer (not shown) if necessary.

FIG. 2 is a front view illustrating an example of the packaging bag according to the present invention. FIG. 3 is a diagram showing a state in which the packaging bag shown in FIG. 2 is sealed. Figure 2 shows the shape of the packaging bag before containing the contents, and Figure 3 shows the shape of the packaging bag after containing and sealing the contents.

As shown in FIG. 2, this packaging bag 10 is composed of, for example, two rectangular laminated packaging materials 6 stacked with the sealant layer on the inner side, as shown in the figure. It is formed by heat-sealing the three end regions 7 in a relatively low temperature region of, for example, 120 ° C. or 160 ° C. At this time, the end 8 including the remaining side is open.

After the contents are accommodated, as shown in FIG. 3, the area including the end 8 is similarly heat-sealed, whereby the packaging bag 10 can be sealed.

The shape of the packaging bag of the present invention can be appropriately modified as needed. Examples of such a shape include a three-sided bag, a gusset bag, a self-standing bag, and a pillow bag.

Hereinafter, the laminated packaging material of the present invention will be described with reference to specific examples, but the present invention is not limited to these examples.

Example

Hereinafter, the present invention will be described specifically with reference to Examples.

Example 1

Biaxially stretched polypropylene film (thickness: 30 im) OPP film). Using a dry laminating machine, apply a polyurethane-based adhesive to one side of this OPP film in a dry state at a coating amount of 5 g / _m2 , and then apply a thickness A substrate was obtained by laminating a 12 μm biaxially stretched polyvinyl alcohol film (hereinafter referred to as a PVA film). On the PVA film surface of the obtained base material, a polyurethane-based adhesive was applied in a dry amount at a coating amount of 3 g / m 2 to obtain an adhesive layer. Using a co-extrusion laminating machine, a linear low-density polyethylene resin layer with a density of 0.915 g // cm3 was formed on the obtained adhesive layer as a sealant layer. To a thickness of 70 μm, and a linear medium-density polyethylene resin layer having a density of 0.939 g / cm 3 thereon by coextrusion at a thickness of 20 μηι. The laminated packaging material of the present invention was obtained by laminating and forming a two-layer laminated sealant layer.

The piercing strength, slipperiness, and abrasion resistance of the obtained laminated packaging material were good.

When a packaging bag was formed using this packaging material and examined in the same manner, the piercing strength, slipperiness, and abrasion resistance were also good. In this way, the use of this laminated packaging material can preserve the contents for a long time! : Excellent packaging bags were obtained.

Further, the following tests and evaluations were performed using the obtained laminated packaging material.

(1) Flexural strength test

Trial of laminated packaging material cut to a size of 205 x 290 mm Prepare a test specimen and repeat it 100,000 times at a temperature of 25 ° C using a gelbo flex tester (with a torsion angle of 44 °, manufactured by Rigaku Corporation, according to ASTMF-3392). After repeating the exercise, the appearance of pinholes was visually inspected to determine the number of pinholes in the test specimen.

The results obtained are shown in Table 1 below.

(2) Vibration test

Using the laminated packaging material, the three sides were heat-sealed with the sealant layer inside, and a three-sided bag having the same dimensions as in FIG. 2 having an inner dimension of 27 Omm x 30.0 mm was created.

In the obtained bag, 900 mL of an infusion solution were filled and sealed, and 10 infusion bags were accommodated, and the opening was heat-sealed to obtain a test packaging bag. The 50 infusion bags were further sealed in cardboard, and the sealed one was attached to a vibration tester compliant with JIS-Z-0 232, with a peak acceleration of ± 4 G and a vertical direction of 15 The vibration was applied for 15 minutes, horizontal direction for 15 minutes and vertical direction for 30 minutes.

After performing the vibration test, the infusion bag was taken out, the appearance of pinholes in the used bags was visually inspected, and the number of pinholes generated per 10 test packaging bags was examined.

Note that a vibration tester conforming to JIS-Z_0232 is a tester having a configuration including a diaphragm and a vibration device.

The results obtained are shown in Table 1 below.

Comparative Example 1

A linear low-density polyethylene resin with a density of 0.915 g / cm3 was extruded at a thickness of 90 / m as a sealant layer. A laminated packaging material was obtained in the same manner as in Example 1 except that a single resin layer was used.

The piercing strength, slipperiness, and abrasion resistance of the obtained laminated packaging material were examined in the same manner as in Example 1, and the bending strength test and the vibration test were performed.

As a result, the obtained laminated packaging material was inferior in slipperiness, abrasion resistance, and piercing strength.

The test results are shown in Table 1 below.

Comparative Example 2

As the sealant layer, a single-layer resin layer extruded with a thickness of 90 μπι from a linear medium-density polyethylene resin having a density of 0.935 g Z cm 3 is used. Except for this, a laminated packaging material was obtained in the same manner as in Example 1.

Although the obtained laminated packaging material had no problem in piercing strength, slipperiness, and abrasion resistance, as a result of the above test, it was inferior in bending resistance.

The test results are shown in Table 1 below.

Comparative Example 3

0.9 15 g / cm on the adhesive layer as a sealant layer

^A general-purpose, medium-density polyethylene with a thickness of 60 μπα and a side chain with a density of 0.935 g / cm3 on a linear low-density polyethylene resin with a density of ³ . Ethylene resin layer with thickness 30 A laminated packaging material was obtained in the same manner as in Example 1, except that the resin layers were co-extruded and laminated to form a two-layer laminated resin layer.

The test results are shown in Table 1 below.

Comparative Example 4

A single-layer resin layer extruded from a linear low-density polyethylene resin with a density of 0.925 g Z cm3 to a thickness of 90 μιη is used as the sealant layer. Except for this, the laminated packaging material was obtained in the same manner as in Example 1.

The obtained laminated packaging material had poor piercing strength and slipperiness.

The test results are shown in Table 1 below.

Example 2

Prepare a 20 μm thick film, and use an extrusion laminating machine to apply a 20 μm thick film to one side of the film. Thickness prepared separately at the same time as extrusion of the resin

Polyethylene extruded from 15 m biaxially stretched nylon film A base material was obtained by a so-called sand tsutira mining method in which the resin material was overlaid and stuck on a ren resin. On the nylon film surface of the obtained base material, a polyurethane-based adhesive was applied in an amount of 3 gm ² in a dry state to obtain an adhesive layer. A co-extrusion laminating machine is used as a sealant layer on the obtained adhesive layer, and a linear low-density polymer having a density of 0.1 SOA g Z cms is formed on the adhesive layer. Co-extrusion of an ethylene resin and a linear medium-density polyethylene resin layer having a density of 0.940 g Z cm3 so that the linear low-density polyethylene resin is on the adhesive layer side The laminated low-density polyethylene resin is 50 nm, and the linear medium-density polyethylene resin is 1 μμπι. Obtained.

The piercing strength, slipperiness, and abrasion resistance of the obtained laminated packaging materials were all good. In addition, when a packaging bag was formed using this packaging material, the piercing strength, slipperiness, and abrasion resistance were good. As described above, it was found that using this laminated packaging material can provide a packaging bag in which the preservability of the contents is excellent over a long period of time.

The obtained laminated packaging material was subjected to the same (1) bending strength test and (2) vibration test as described above.

The results obtained are shown in Table 1 below.

Comparative Example 5

Laminated packaging in the same manner as in Example 2, except that the thickness of the linear low-density polyethylene resin is changed to 55 μm and the thickness of the linear medium-density polyethylene resin layer is changed to 5. The material was obtained. The obtained laminated packaging material was subjected to a bending strength test and a vibration test in the same manner as in Example 1.

The results obtained are shown in Table 1 below.

table 1

(Note) Unit: Number of pinholes generated Z test piece

Number of bags with pinholes / number of tests From Table 1, it can be seen that the number of pinholes in the laminated packaging materials of Examples 1 and 2 was 0 even after the gelbo flex test was performed 100 times. I understood. In addition, no bags with pinholes were formed after the vibration test was performed on bags formed using this laminated packaging material.

In the laminated packaging materials of Comparative Example 1, Comparative Example 4 and Comparative Example 5, the number of pinholes generated was 0 after the gel boflex test was performed 100 times, but the laminated packaging materials were used. A pinhole was formed in the molded packaging bag after the vibration test. The laminated packaging materials of Comparative Example 2 and Comparative Example 3 generated a large number of pinholes after the gel-bo flex test was performed 100 times, and the bags made using the laminated packaging materials were also subjected to the vibration test. A pinhole has occurred.

According to the present invention, the sealant layer of the laminated packaging material is a linear low-density polyethylene resin layer having a density of 0.89 to 0.925 g Zcm 3 on the adhesive layer side. Density is greater than 0.925 g / cm 3 on the side in contact with the object, and linear with 0.940 g / cm 3 or less It has a two-layer structure consisting of a medium-density polyethylene resin layer, and has a thickness a of a linear low-density polyethylene resin layer and a thickness b of a linear medium-density polyethylene resin layer. The ratio of a / b is 3 to 5 and b is 5 to 20 μm, so that various physical properties such as piercing strength, sliding property, abrasion resistance, bending resistance, pinhole resistance, etc. ing. Industrial applicability

The laminated packaging material of the present invention can be easily formed and sealed by heat sealing, and can be used as a packaging bag for accommodating various contents.

Claims

The scope of the claims

1. A substrate consisting of a single-layer film or multi-layer film

An adhesive layer provided on one surface of the base material,

A linear low-density polyethylene resin layer having a density of 0.89 to 0.925 g / cm 3 provided on the adhesive layer; A linear medium-density polyethylene having a density larger than 0.925 g Z cm 3 and less than 0.940 g Z cms provided on the linear low-density polyethylene resin layer. When the thickness of the linear low-density polyethylene resin layer is a and the thickness of the linear medium-density polyethylene resin layer is b, A laminated packaging material, characterized in that the thickness ratio a Z b is 3 to 5, and b is 5 and 20 μιη.

2. The base material is an aluminum foil, a biaxially stretched polypropylene single-layer film, a biaxially stretched nylon single-layer film, a biaxially stretched polyester single-layer film, Laminated films of these single-layer films and aluminum-deposited layers, silicon oxide-deposited polyester films, aluminum oxide-deposited polyester films, and biaxially-extended polyvinyl alcohol films 2. The laminated packaging material according to claim 1, wherein the laminated packaging material comprises at least one kind of film selected from the group consisting of NOREM and polyethylene bilayer alcohol laminated film.

3. The laminated packaging material according to claim 2, wherein the base material has gas-parallel compatibility.

4. A substrate made of a single-layer film or a multi-layer film, an adhesive layer provided on the surface of the substrate, and a two-layered sealer provided on the adhesive layer A packaging bag formed by heat-sealing with the sealant layer inside, comprising a laminated packaging material having

The double-layer laminated sealant layer is a linear low-density polyethylene resin layer having a density of 0.89 to 0.925 g / cm3 provided on the adhesive layer, And a linear medium-density polymer having a density larger than 0.9 SSS g Z cms and having a density of 0.940 g Z cm3 or less provided on the linear low-density polyethylene resin layer. When the thickness of the linear low-density polyethylene resin layer is a, and the thickness of the linear medium-density polyethylene resin layer is b, A packaging bag, characterized in that the ratio aZb is 3 to 5, and b is 5 to 20 m.

5. The base material is

Aluminum foil, biaxially stretched polypropylene single-layer film, biaxially stretched nylon single-layer film, and biaxially stretched polyester single-layer film card Group (I)

Aluminum vapor deposited layer, silicon oxide vapor deposited polyester film, aluminum oxide vapor deposited polyester film, biaxially stretched poly vinylinole resin, and polyethylene / vinyl / leano resin And at least one film selected from the group consisting of laminated films of the above-mentioned group (I) and a single-layer film of the group (I). 5. The packaging bag according to claim 4, wherein the packaging bag contains one kind. 19

6. The packaging bag according to claim 5, wherein the base material has gas-paresity.