JP3021817B2 - Composite materials for packaging - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging composite material used for packaging foods and drinks, pharmaceuticals, chemicals and the like.
More specifically, the present invention relates to a composite material for packaging excellent in gas barrier properties, fragrance retention and the like, which is suitable for packaging foods and drinks, pharmaceuticals, chemicals, and the like.

[0002]

2. Description of the Related Art In recent years, as plastic packaging materials have progressed to plastics, it has been pointed out that plastics have disadvantages such as difficulty in recovery and reuse, environmental pollution by waste, and damage to incinerator walls during incineration. Have been. In this regard, paper containers made of paperboard and the like have advantages in that they are collected after use, can be used as recycled paper, and incineration is easy. However, paperboard not only easily permeates gases such as oxygen and water vapor, but also easily adsorbs water, odors, and aromas. The fact is that it is not suitable for packaging applications that dislike deterioration.

[0003] In order to improve the insufficient gas barrier properties of paperboard used for packaging, the thickness of the paperboard is 6 to 15 µm.
Various types have been proposed, such as a laminated aluminum foil having a thickness of m or a layer covered with a vinylidene chloride-based resin layer. However, such a laminate has a problem that when incinerated, the aluminum foil remains in the residual ash when the aluminum foil is laminated, and when the aluminum foil is covered with a vinylidene chloride resin layer. In addition, when incinerated, chlorine-containing compounds are generated together with the flue gas, causing damage to the incinerator and environmental pollution.

[0004] From such a viewpoint, a packaging material using a vapor-deposited film having gas barrier properties has recently attracted attention. For example, there has been proposed a paper container in which a laminated film in which a vapor-deposited layer of silicon oxide is provided on a polyester film and a polyolefin film having heat sealing properties is laminated on the vapor-deposited film is a constituent material (for example, Japanese Patent Application Laid-Open No. No. 281838, Japanese Utility Model Application No. 1-96
879). However, such paper containers,
Although it has a high degree of gas barrier properties, there is a problem that the sealant layer made of polyolefin adsorbs flavor components contained in foods and drinks, alters the contents, and impairs the commercial value.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a composite material for packaging, which has a high gas barrier property, has excellent fragrance retention for contents, is inexpensive, and is easy to treat after use. It is intended for.

[0006]

The present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art.
If a vapor-deposited film in which a silicon oxide thin film layer is provided on one side of a film made of a polyester resin having a heat-sealing property in a non-crystalline state is used as an inner layer material of a packaging composite material, a high degree of gas barrier property and content can be obtained. The present invention has been completed by obtaining the knowledge that a composite material for packaging having excellent fragrance retention properties against an object can be solved at once with other disadvantages of the conventional packaging material.

Accordingly, the present invention provides a vapor-deposited film in which a silicon oxide thin film layer having a thickness in the range of 10 to 300 nm is provided on one side of a film made of a polyester resin having heat sealing properties, as an inner layer material. The present invention provides a packaging composite material characterized in that an outer layer material including paperboard is adhesively laminated on a surface of a silicon oxide thin film layer of the material.

Hereinafter, the present invention will be described in detail. The packaging composite material according to the present invention is composed of an inner layer material and an outer layer material including paperboard.As the inner layer material, a silicon oxide thin film layer is provided on one surface of a film made of a polyester resin having heat sealability. A vapor deposited film is used.

The polyester resin film used as the inner layer material is a substantially non-crystalline film, and has a T-peel strength of 1 kg / 15 mm width or more in a heat sealing temperature range of 120 to 200 ° C. It has strength. As such a film, polyethylene terephthalate, isophthalic acid, adipic acid, glutaric acid or the like as an acid component, 1,4-cyclohexanedimethanol as a diol component,
A film made of a polyester copolymer modified with 1,4-butanediol or the like, a film made of a polymer alloy in which an acrylate resin or the like is mixed with a polyester resin, and the like can be given. Also, a film or sheet obtained by quenching polyethylene terephthalate immediately after extrusion can be suitably used.

[0010] The thickness of the film made of the polyester resin is not particularly limited and can be appropriately selected depending on the type of the resin and the thickness of the outer layer material to be used.
It is preferable that the thickness be in the range of 200 μm.

The inner layer material used in the present invention has a silicon oxide thin film layer provided on one side of a film made of the polyester resin. The silicon oxide thin film layer can be formed using, as a raw material, a material selected from silicon monoxide, silicon dioxide, or a silicon oxide having a mixed composition thereof. These silicon oxides for forming a thin film layer may contain impurities such as magnesium, iron, calcium or oxides of 10% by weight or less.

The method for forming a silicon oxide thin film layer on a film made of a polyester resin is not particularly limited, and any of conventionally known methods such as a vacuum deposition method, a sputtering method, and an ion plating method can be used. Method. When forming a silicon oxide thin film layer on a film made of a polyester resin, in order to improve the adhesiveness between the film and the thin film layer, a corona discharge treatment, a low-temperature plasma treatment, a silane coupling agent application, Surface treatment such as applying a mixture of a saturated polyester and an isocyanate may be performed.

The thickness of the silicon oxide thin film layer formed on one side of the polyester resin film is 10 to 30.
0 nm, preferably 30 nm.
It is preferable to set the range to 200 nm. The thickness of the thin film layer is 1
If the thickness is less than 0 nm, the gas barrier property becomes insufficient, and if it exceeds 300 nm, cracks or peeling may occur in the thin film layer.

The outer layer material used in the composite packaging material according to the present invention includes paperboard or processed paperboard.
As the paperboard, all paperboards that are usually used for paper containers and the like can be used, but those having 100 to 500 g / m 2 are preferably used. Also, on one side of the paperboard,
In order to provide additional functions such as surface protection or printing suitability, handling suitability, etc., and on the other side, in order to strengthen adhesion with the silicon oxide thin film layer, by extrusion lamination method or dry lamination method, etc. One provided with a resin layer having a thickness of 10 to 30 μm can be used. Further, as a matter of course, another resin film or the like may be laminated on the outermost layer of the outer layer material as a further protective layer.

The composite material for packaging according to the present invention is configured such that the outer layer material is bonded and laminated on the surface of the silicon oxide thin film layer of the inner layer material. Conventionally known general methods such as a dry lamination method using an adhesive such as a urethane-based adhesive, an acrylic-based adhesive, or a polyester-based adhesive, and other extrusion lamination methods are used for bonding and laminating the outer layer material to the surface of the silicon oxide thin film layer. Can be done in any way.

The composite material for packaging according to the present invention described in detail above is suitable for manufacturing containers for storing articles, such as foods and drinks, pharmaceuticals, and chemicals, which are resistant to intrusion of oxygen, water vapor, and the like. The article to be formed is not limited, such as a liquid, a solid, a solid-liquid mixture, a jelly, and a paste.
Moreover, since the packaging composite material according to the present invention does not contain aluminum foil, it is also used for manufacturing containers that require heating and sterilization in a microwave oven.

The shape of the container made from the packaging composite material according to the present invention may be any of various conventionally known storage articles such as a tetrahedron, a cube, a cylinder, a truncated pyramid, and a truncated prism. There is no restriction as long as it can be stored and stored.
The capacity of these containers is usually selected in the range of several tens of milliliters to several liters. When a cup-shaped container for storing a liquid material or the like, a container is formed from the composite material for packaging according to the present invention, and a lid made of the same material is prepared, and an adhesive is provided on the upper portion of the cup or heat-sealed. It can be used sealed by the method.

[0018]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following examples, the evaluation of various characteristics of the composite material for packaging was performed by the following methods. 1) Oxygen permeability (cc / m ² · 24 hr · atm) Using an OXY-TRAN 100 type oxygen permeability measuring device manufactured by Modern Control, temperature 25 ° C., relative humidity 9
It was measured under 0% conditions. 2) Residue after heating (% by weight) The composite material is cut, put into a magnetic crucible, and weighed in advance (X).
Was measured, placed in an electric furnace, heated at 1200 ° C. for 2 hours, and then cooled. The weight (Y) of the residue was measured, and the heating residue was determined from the following equation. Heating residue = Y / X × 100 3) Amount of sorbed d-limonene (mg / g) Absorbent cotton containing d-limonene was put in a three-side sealed bag made of a composite material, and then the inlet was sealed and sealed. After standing at room temperature for 14 days, d-limonene sorbed on the composite material was extracted with a predetermined amount of ethyl acetate, and d-limonene in the extract was quantified by gas chromatography. 4) Heat seal strength (Kg / 15mm width) The inner layer material of the composite material is heated at 160 ° C and pressure 2Kg / c.
The T-peel strength was measured for those heat-sealed under the conditions of m ² and a pressurization time of about 1 second.

Example 1 A 30 μm thick polyester resin film having heat sealing properties (estina P-, manufactured by Sekisui Chemical Co., Ltd.)
320), a 50 nm-thick silicon oxide thin film layer was formed on one surface of a single-sided surface using a high-frequency induction heating type vacuum evaporation apparatus, using silicon monoxide having a purity of 99.9% as an evaporation raw material, to prepare an inner layer material. Then, on the surface of the silicon oxide thin film layer of the inner layer material, paperboard on which polyethylene having a thickness of 20 μm is extruded and laminated on both surfaces is laminated via a urethane-based adhesive, and a polyester resin film / silicon oxide thin film layer is laminated.包装 A packaging composite material having a structure of polyethylene layer / paperboard / polyethylene layer was obtained. With respect to the obtained composite material, the various properties described above were evaluated according to the above-mentioned methods. The results are shown in Table 1 below.

Example 2 In the example described in Example 1, a polyester resin film was replaced with a 30 μm-thick polyester resin film (Estina P-322, manufactured by Sekisui Chemical Co., Ltd.). In the same procedure as above, prepare the inner layer material,
Next, a composite material for packaging was obtained. Various properties of the obtained composite material were evaluated as in the same example. The results are also shown in Table 1.

Example 3 A composite material for packaging was produced in the same manner as in Example 1 except that the method of bonding the inner layer material and the resin-laminated paperboard was changed to the extrusion lamination method using polyethylene. I got Various properties of the obtained composite material were evaluated as in the same example. The results are also shown in Table 1.

Example 4 In the example described in Example 1, the thickness of the silicon oxide thin film layer formed on one side of the polyester resin film was 20
An inner layer material was prepared in the same procedure as in the same example except that the thickness was changed to nm, and then a composite material for packaging was obtained. Various properties of the obtained composite material were evaluated as in the same example. The results are also shown in Table 1.

Comparative Example 1 In the example described in Example 1, the thickness of the silicon oxide thin film layer formed on one side of the polyester resin film was 5 n.
An inner layer material was prepared in the same procedure as in the same example except that m was changed, and then a composite material was obtained. Various properties of the obtained composite material were evaluated as in the same example. The results are also shown in Table 1.

Comparative Example 2 An inner layer material was prepared in the same manner as in Example 1 except that the polyester resin film was replaced with a biaxially oriented polyethylene terephthalate film having a thickness of 25 μm. Next, a composite material was obtained. Various properties of the obtained composite material were evaluated as in the same example. The results are also shown in Table 1.

Comparative Example 3 An unstretched polypropylene film was applied to the surface of a polyester resin film (inner layer material) of the same kind of composite packaging material obtained in the example described in Example 1 via a urethane adhesive. Lamination was performed to obtain a composite material having a structure of unstretched polypropylene film‖polyester resin film / silicon oxide thin film layer‖polyethylene layer / paperboard / polyethylene layer. About the obtained composite material, as in the same example,
Various properties were evaluated. The results are also shown in Table 1.

Comparative Example 4 An unstretched polypropylene film‖aluminum was prepared in the same manner as in Example 3 except that an aluminum foil having a thickness of 9 μm was used instead of the inner layer material used in Example 3. A composite material having a structure of foil / polyethylene layer / paperboard / polyethylene layer was obtained. Various properties of the obtained composite material were evaluated as in the same example. The results are also shown in Table 1.

[0027]

[Table 1]

As is clear from Table 1, the composite material for packaging according to the present invention has a low oxygen permeability and a high gas barrier property, a small amount of adsorbed d-limonene, an excellent fragrance retention property, and It has sufficient heat sealing strength and the amount of heat residue is small. On the other hand, a composite material that does not satisfy the requirements of the present invention does not exhibit the excellent effects of the present invention.

[0029]

The present invention having the above-described structure has the following particularly remarkable effects, and its industrial utility value is extremely large. (1) The composite material for packaging according to the present invention has high gas barrier properties, excellent fragrance retention, and sufficient heat seal strength. (2) The packaging composite material according to the present invention can be manufactured at low cost because the inner layer material itself has heat sealability and does not require lamination of a sealant layer separately used in a conventional composite material. (3) The storage container made from the composite material for packaging according to the present invention does not cause damage to the incinerator or generate harmful compounds even during the incineration treatment, and the treatment after use is simple. (4) Since the storage container made of the composite material for packaging according to the present invention does not contain a metal such as aluminum foil, it can be used for heating and sterilization by a microwave oven.

Continuation of the front page (56) References JP-A-63-281838 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (1)

(57) [Claims] 1. A vapor-deposited film in which a silicon oxide thin film layer having a thickness in the range of 10 to 300 nm is provided on one side of a film made of a polyester-based resin having heat sealability as an inner layer material. A composite material for packaging, characterized in that an outer layer material including paperboard is adhesively laminated on a surface of a material thin film layer.