JP2001096684A - Transparent barrier laminated film having self-heat sealability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent barrier laminated film having self-heat sealability and excellent barrier properties. SOLUTION: A transparent polypropylene resin film is used as a base material (C) and a coating layer (A) mainly comprising a polypropylene type copolymer is provided on one surface of the base material (C) and at least one barrier layer mainly comprising a vinyl alcohol copolymer containing vinyl alcohol as a main monomer component is further provided on the outer surface of the coating layer (A) and a coating layer (B) mainly comprising a polypropylene type copolymer is provided on the other surface of the base material (C) to constitute a transparent barrier laminated film having self-heat sealability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent barrier laminate film having a self-heat sealing property and an excellent barrier property.

[0002]

2. Description of the Related Art Conventionally, a polyvinylidene chloride resin (PVD) has been used as a transparent barrier film having a gas barrier property.
A large number of transparent polypropylene films coated with C) or polyvinyl alcohol, and polyester films transparently evaporated with silica or alumina have been used. However, since these films do not have a self-heat-sealing property, they are used after being laminated with a non-stretched polypropylene film (CPP) or a polyethylene film (PE) having a self-heat-sealing property and imparting a heat-sealing property. It is common.

In the case of a pillow-type package, the center seal portion is often heat-sealed in an envelope-attached form overseas, but in Japan, recently, there is a growing tendency to minimize the area of a film used for packaging. There has been a demand for a pillow-shaped center seal portion attached to an envelope, which has hardly ever existed in Japan.
In the case of an envelope-attached form, it is necessary to heat seal between the outermost layer and the innermost layer of the film. However, in the case of a conventional transparent barrier film, the self-heat sealing It was necessary to laminate a transparent film on both sides of the transparent barrier film. However, at that time, the following two problems have occurred. Further lamination on both sides of the transparent barrier film increases the film weight. Since the adhesion strength between the barrier layer of the transparent barrier film and the base material is weak, the strength in the case of an envelope-attached form is low.

[0004]

DISCLOSURE OF THE INVENTION The present invention has a self-heat-sealing property, excellent adhesion strength between a barrier layer and a substrate, and is particularly suitable as a transparent barrier property for a packaging material in the case of an envelope-attached form. It is intended to provide a film.

[0005]

According to the present invention, a transparent polypropylene resin film is used as a substrate (C).
Has a coating layer (A) mainly composed of a polypropylene-based copolymer on one surface, and a vinyl alcohol copolymer containing vinyl alcohol as a main monomer component on an outer surface of the coating layer (A) via an anchor layer. Having at least one barrier layer mainly composed of
Is a transparent barrier laminate film having a self-heat-sealing property, which has a coating layer (B) mainly composed of a polypropylene-based copolymer on the other surface.

[0006] The present invention provides a substrate with excellent mechanical properties such as excellent glossiness and tensile properties in addition to a barrier property against water vapor.
Using a transparent polypropylene-based resin film that has many desirable properties such as substantially harmless and odorless,
One side of the substrate has a coating layer mainly composed of a polypropylene-based copolymer, and further improves the adhesion of the barrier layer to the substrate through an anchor layer, and further has a polypropylene-based copolymer on the other side. Self-heat-sealing properties are provided by having a coating layer mainly composed of

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the composition of the polypropylene resin composition constituting the transparent polypropylene resin film of the base material (C) is not particularly limited as long as it has transparency. 7
It is preferable that the resin composition contains 0% by weight or more, more preferably 80% by weight or more.

The base material (C) may be a single layer or 2
A multilayer structure having at least one layer may be used, but in any case, at least one layer preferably contains a terpene resin and / or a petroleum resin. By containing a terpene resin and / or a petroleum resin, the barrier property against water vapor of the transparent barrier film of the present invention is improved.

Examples of the terpene resin include pinene, kalen, myrcene, limonene, and hydrogenated resins thereof. Examples of the petroleum resin include resins mainly obtained from cyclopentadiene and higher olefinic hydrocarbons, and those obtained by hydrogenating them. The terpene resin and / or petroleum resin may be used alone or in combination of two or more. The amount of the terpene resin and / or petroleum resin is preferably 2 to 2 parts of the entire resin composition constituting the layer containing the terpene resin and / or petroleum resin.
The content is preferably 30% by weight, more preferably 5 to 20% by weight. The resin composition constituting the base material (C) includes:
Other components may be contained as long as the action of the present invention is not impaired.

[0010] The thickness of the substrate (C) is not particularly limited, and can be appropriately set according to the use of the transparent barrier laminate film of the present invention.

In the present invention, the coating layer (A) mainly comprises a polypropylene copolymer. The comonomer components of such polypropylene copolymers include ethylene, 1-butene, 2-butene, 1-pentene, 1-pentene,
Alkenes having about 2 to 6 carbon atoms, such as hexene, 3-methylpentene and 4-methylpentene, are exemplified. The polypropylene-based copolymer constituting the coating layer (A) is preferably a copolymer containing at least one comonomer component selected from propylene, ethylene and butene, for example, an ethylene-propylene copolymer and / or an ethylene-butene-propylene copolymer. Polymers are preferred. More preferably, propylene is contained in an amount of at least 84% by weight of the entire polypropylene-based copolymer, particularly preferably 84 to 99% by weight, and ethylene and / or butene is 16% by weight or less of the entire polypropylene-based copolymer,
Particularly preferred is a copolymer containing 16 to 1% by weight. In addition, the polypropylene-based copolymer constituting the coating layer (A) has a range in which the action of the present invention is not impaired.
Other components such as additives may be contained.

The thickness of the coating layer (A) is not particularly limited, but is preferably 0.1 μm to 2 μm, and more preferably 0.5 μm to 1 μm. Thickness is 0.1μ
m or less, the adhesion strength between the base material (C) and the barrier layer is apt to decrease, and when it is 2 μm or more, the transparency of the transparent barrier laminate film of the present invention is liable to decrease and disadvantageous in cost. Easy to be.

In the present invention, the coating layer (B) mainly comprises a polypropylene copolymer. The comonomer components of such polypropylene copolymers include ethylene, 1-butene, 2-butene, 1-pentene, 1-pentene,
Alkenes having about 2 to 6 carbon atoms, such as hexene, 3-methylpentene and 4-methylpentene, are exemplified. The polypropylene-based copolymer constituting the coating layer (B) is preferably a copolymer containing at least one comonomer component selected from propylene, ethylene and butene, for example, an ethylene-propylene copolymer and / or an ethylene-butene-propylene copolymer. Polymers are preferred. More preferably, propylene is contained in an amount of at least 84% by weight of the entire polypropylene-based copolymer, particularly preferably 84 to 99% by weight, and ethylene and / or butene is 16% by weight or less of the entire polypropylene-based copolymer,
Particularly preferred is a copolymer containing 16 to 1% by weight. In addition, the polypropylene-based copolymer constituting the coating layer (B) has a range in which the action of the present invention is not impaired.
Other components such as additives may be contained.

The thickness of the coating layer (B) is not particularly limited, but is preferably 0.5 μm to 5 μm, and more preferably 1 μm to 3 μm. When the thickness is 0.5 μm or less, the heat-sealing property of the transparent barrier laminate film of the present invention tends to decrease, and when the thickness is 5 μm or more, the transparency and feeling of the transparent barrier laminate film of the present invention decrease. And it is easy to be disadvantageous in terms of cost.

In the present invention, the material constituting the anchor layer is not particularly limited as long as it enhances the adhesion between the coating layer (A) and the barrier layer. Examples thereof include urethane-based, polyethyleneimine-based, and polybutadiene-based materials. Any known or commonly used anchor coating agent can be used. Among these, polyethyleneimine-based and urethane-based anchor coating agents are preferable from the viewpoint of adhesive strength and water resistance. In addition,
The anchor layer may contain other components such as additives as long as the action of the present invention is not impaired.

The thickness of the anchor layer is not particularly limited, and may be appropriately set depending on the constitution of the coating layer (A) and the barrier layer, the desired adhesive strength, and the like.
It is good to be set to 0.5 to 1 g / m < ² >.

The transparent barrier laminate film of the present invention has at least one barrier layer mainly composed of a vinyl alcohol copolymer containing vinyl alcohol as a main monomer component. By using the above-mentioned vinyl alcohol copolymer as a constituent material of the barrier layer, the barrier layer has excellent barrier properties against oxygen gas. Preferably, vinyl alcohol, which is the main monomer component, accounts for 70 to 99 mol%, more preferably 80 to 98 mol%, based on all monomer components in the vinyl alcohol copolymer. Examples of the monomer components other than the vinyl alcohol include vinyl acetate and ethylene. The barrier layer may contain other components such as additives as long as the effects of the present invention are not impaired.

The thickness of the barrier layer is not particularly limited, and may be appropriately set depending on desired barrier properties and the like.

The method for producing the transparent barrier laminated film of the present invention is not particularly limited, and a generally used film forming method and laminating method can be used. Preferably,
The substrate (C), the coating layer (A), and the coating layer (B) are preferably formed simultaneously by a co-extrusion method. The same coextrusion method can be used even when the substrate (C) has a multilayer structure. Preferably, after co-extrusion, the film is stretched at least uniaxially, more preferably biaxially. Extrusion conditions and stretching conditions can be appropriately set according to the material and thickness of each layer used, desired physical properties, and the like.

After the formation of the coating layer (A), for example, the constituent material of the anchor layer is formed on the surface of the coating layer (A) by, for example, dissolving or dispersing in a solvent as needed to form a coating solution. It can be formed by a method. The solvent of the coating liquid may be either an aqueous solvent or an organic solvent. In addition,
When forming the anchor layer, the surface of the coating layer (A) may be subjected to a conventional surface treatment, for example, a corona discharge treatment, a flame treatment, a plasma treatment, an ultraviolet irradiation treatment, an electron beam irradiation treatment, or the like.

After forming the coating layer (A), for example, a constituent material of the barrier layer is formed on the surface of the coating layer (A) by, for example, dissolving or dispersing in a solvent as needed to form a coating solution. It can be formed by a method. The coating solution may be a water-based or organic solvent, but is preferably water or a mixture of water and a hydrophilic solvent.
When a plurality of barrier layers are provided, an anchor layer may be provided between the barrier layers.

The transparent barrier laminate film of the present invention has other layers such as a barrier layer in which vinyl alcohol as a monomer component is made of a material other than a vinyl alcohol copolymer as long as the action of the present invention is not impaired. May be.

The transparent barrier laminate film of the present invention preferably has an adhesion strength of 30 to the substrate (C) of the barrier layer.
The width is preferably 0 g / 15 mm width or more. Adhesion strength is 30
When the thickness is less than 0 g / 15 mm width, the barrier layer is easily peeled off, and the lamination strength when another film is laminated on the barrier layer side, such as when forming a packaging material using the transparent barrier laminate film of the present invention. In other words, the heat sealing strength is lowered when another heat sealable film is laminated on the barrier layer side and heat sealed in an envelope pasting form or the like.

The transparent barrier laminate film of the present invention preferably has a heat-sealing strength of the coating layer (B) of 300 g / g.
The width is preferably 15 mm or more. Heat seal strength is 3
When the width is less than 00 g / 15 mm, when the packaging is performed using the transparent barrier laminate film of the present invention or the packaging material using the transparent barrier laminate film of the present invention, the packaging material such as bag breakage is likely to be damaged.

The transparent barrier laminate film of the present invention can be used alone as a packaging material. For example, it is laminated with another material such as a non-stretched transparent polypropylene resin film having heat sealability and used as a packaging material. You can also. The configuration and lamination method of the packaging material are not particularly limited. Unstretched transparent polypropylene-based resin film, by laminating on the barrier layer side of the transparent barrier laminate film of the present invention, has heat sealability on both sides, by measurement, also the adhesion of the barrier layer to the substrate An excellent packaging material can be obtained. Further, the transparent barrier laminate film of the present invention may be subjected to a coloring treatment or an image forming treatment by printing or the like.

Hereinafter, the present invention will be described in more detail with reference to Test Examples and Examples, but the present invention is not limited thereto. Test example Test method (1) Adhesive strength between substrate (C) and barrier layer [Strength that does not cause peeling between barrier layer and anchor layer or between anchor layer and coating layer (A)]
3. Laminating adhesive (Toyo Morton Co., Ltd., T
M329) and laminating adhesive (Toyo Morton Co., Ltd.)
CAT-8B) and ethyl acetate at a weight ratio of 4.
A laminated adhesive mixed so as to be 8: 4.8: 10.4 is applied to the surface of the barrier layer of the film so as to have a thickness after drying of ² to 2.5 g / m ^2, and after drying, 38dyn with corona treatment on the surface where the laminating adhesive is applied
e / cm or more) was pressed against a corona-treated surface of a transparent polypropylene resin (OPP) film having a thickness of 20 μm and having been subjected to the treatment. 24 hours after crimping, 40 ° C, 30% RH
Was stored under the following conditions. 15mm
A test piece was prepared by cutting it into strips of width
In accordance with C.127, the transparent barrier laminate film and the OPP film on one end side of the test piece are held at their respective ends, and at a speed of 300 mm / min in a direction in which the transparent barrier laminate film and the OPP film are peeled off. The strength at the time of pulling was measured and defined as the adhesion strength.

(2) Heat Sealing Strength of Coating Layer (B) With respect to the transparent barrier laminate films of Examples 1 to 3, Comparative Examples 1 to 3, and Reference Example 1, two films were applied to the coating layer (B).
Laminated so that they are in close contact with each other, 140 ° C, 1 kg / c
Heat sealing was performed for 1 second at a pressure of m ² , and cut into a strip having a width of 15 mm to prepare a test piece. JIS K71
According to No. 27, the same end of the test piece in front of the end of the transparent barrier laminated film on one end side of the test piece is held, and 300 mm / min is set in a direction in which the transparent barrier laminated films are separated from each other. The maximum strength at the time of pulling at a speed of was measured and defined as heat seal strength.

(3) Oxygen Gas Barrier Property of Film For the transparent barrier laminate films of Examples 1 to 3, Comparative Examples 1 to 3, and Reference Example 1, an oxygen permeability measuring device (OX-T) was used.
RAN 2/20, manufactured by MOCON) at 20 ° C.
The oxygen permeability under the condition of 60% RH was measured.

(4) Water Vapor Barrier Property of Film For the transparent barrier laminated films of Examples 1 to 3, Comparative Examples 1 to 3, and Reference Example 1, a water vapor permeability measuring device (PER)
MATRAN W200, manufactured by MOCON)
The water vapor transmission rate was measured at 40 ° C. and 90% RH.

2. Test results The results of the above tests (1) to (4) are shown in Table 1.

[0031]

EXAMPLES [Preparation of Coating Solution] Preparation Example 1 Preparation solution 1 was prepared by dissolving polyethyleneimine in distilled water to a concentration of 1% by weight. Preparation Example 2 Ethylene-vinyl alcohol copolymer (vinyl alcohol / ethylene = 90/10 (molar ratio), saponification degree 99
%, Average molecular weight of 500) was added to distilled water so as to be 10% by weight, and stirred and dissolved at 95 ° C. to prepare Preparation Liquid 2. Preparation Example 3 A preparation liquid 3 was prepared by mixing 10% by weight with distilled water containing no ethylene as a monomer component in polyvinyl alcohol (saponification degree: 99%, average molecular weight: 500) at 95 ° C.

Example 1 An unstretched film was formed by a co-extrusion method and further biaxially stretched to obtain a substrate (C) having a thickness of 20 μm.
A coating layer (A) on one side of a polypropylene film
As a coating layer (B) on the other surface of a polypropylene copolymer containing 5% by weight of a monomer component ethylene as a coating layer (B) on the other surface. A multilayer film having a layer having a thickness of 1 μm was prepared. After the surface of the coating layer (A) of the multilayer film is treated by corona treatment so that the surface tension becomes 38 dyne / cm or more, the thickness of the prepared solution 1 after drying is 0.2 g.
/ M ² and dried to form an anchor layer. Then, the above-mentioned preparation liquid 2 is further applied to the surface of the anchor layer.
Was applied to a thickness of 2 g / m ² after drying, and dried to form a barrier layer, thereby obtaining a transparent barrier laminate film.

Example 2 A transparent barrier laminate film was obtained in the same manner as in Example 1 except that the thickness of the coating layer (A) was 0.5 μm and the barrier layer was formed using the preparation liquid 3.

Example 3 A transparent barrier film was prepared in the same manner as in Example 1 except that the base material (C) was a 20 μm thick polypropylene resin film containing 4.0% by weight of petroleum resin based on the whole resin. A laminated film was obtained.

Comparative Example 1 A transparent barrier laminate film was obtained in the same manner as in Example 1 except that no anchor layer was formed.

Comparative Example 2 One surface of a biaxially stretched polypropylene film having a thickness of 20 μm was subjected to corona treatment to have a surface tension of 38 dyne.
/ Cm 2 or more, the above-mentioned preparation liquid 1 was applied so that the thickness after drying was 0.2 g / m ^2, and dried to form an anchor layer. Thereafter, the above prepared solution 2 was further applied to the surface of the anchor layer so that the thickness after drying was 2 g / m ² , and dried to form a barrier layer, thereby obtaining a transparent barrier laminated film.

Comparative Example 3 A transparent barrier laminate film was obtained in the same manner as in Example 1 except that the coating layer (B) was not formed.

Reference Example 1 Example 1 except that the thickness of the coating layer (B) was 0.3 μm.
In the same manner as in the above, a transparent barrier laminate film was obtained.

[0039]

[Table 1]

[0040]

The transparent barrier laminate film of the present invention is
Because of its excellent self-heat-sealing properties and high adhesion strength between the base material and the barrier layer, even when the packaging material is formed by laminating with a non-stretched polypropylene resin film, etc., the outermost layer and innermost layer of the packaging material It has excellent heat sealing properties and heat sealing strength, and is lightweight. Therefore, it can be used in various packaging forms such as an envelope form.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 4F100 AK02A AK07A AK07B AK07D AK21C AK28A AK62B AK62D AK64B AK64D AK69C AL01B AL01C AL01D BA04 BA06 BA10C BA10D BA16 CC00 EH20 EH46 JEJBJJL12 J15B06

Claims (9)

[Claims] A transparent polypropylene resin film is used as a substrate (C), and one surface of the substrate (C) has a coating layer (A) mainly composed of a polypropylene copolymer,
Further on the outer surface of the coating layer (A), via an anchor layer,
It has at least one barrier layer mainly composed of a vinyl alcohol copolymer containing vinyl alcohol as a main monomer component, and has a coating layer (B) mainly composed of a polypropylene copolymer on the other surface of the substrate (C). A transparent barrier laminate film having a self-heat-sealing property. 2. The transparent barrier laminate film according to claim 1, wherein the polypropylene copolymer constituting the coating layer (A) is an ethylene-propylene copolymer and / or an ethylene-butene-propylene terpolymer. . 3. The transparent barrier property according to claim 1, wherein the polypropylene copolymer constituting the coating layer (B) is an ethylene-propylene copolymer and / or an ethylene-butene-propylene terpolymer. Laminated film. 4. The transparent barrier laminate film according to claim 1, wherein the thickness of the coating layer (A) is 0.1 μm or more and 2 μm or less. 5. The transparent barrier laminate film according to claim 1, wherein the thickness of the coating layer (B) is 0.5 μm or more and 5 μm or less. 6. The base material (C) has a multilayer structure of one or more layers, and at least one layer contains a terpene resin and / or a petroleum resin. The transparent barrier laminate film according to any one of the above. 7. The transparent barrier laminate film according to claim 1, wherein the adhesion strength of the barrier layer to the substrate (C) is at least 300 g / 15 mm width. 8. The heat sealing strength of the coating layer (B) is 30.
The width is at least 0 g / 15 mm width.
8. The transparent barrier laminate film according to any one of items 1 to 7. 9. A packaging material using the transparent barrier laminate film according to claim 1. Description: