JP2002086647A - Polyolefin film and laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyolefin film which is applicable to a bag skin material and a floor material by laminating it on a ground in place of a plasticized polyvinyl chloride film and a laminated film with the use of the polyolefin film. SOLUTION: A film which is made of a single- or multi-layer polyolefin resin and has a tensile modulus of elasticity in the extrusion direction (MD) of 10-80 MPa, stress at 5% elongation of at least 1 MPa, and the ratio of stress in MD to stress in TD at 5% elongation of 1-1.5 is used as the polyolefin film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyolefin film and a laminated film using the polyolefin film.

[0002]

2. Description of the Related Art Conventionally, a film for backing a bag skin material or a film backed and bonded to a flooring material is required to have a performance such as a feeling, a waterproof property and an adhesive property to a fabric. Vinyl chloride films have been used.
In particular, if you are using nylon fabric for the bag skin material,
In many cases, a plasticized vinyl chloride film and a nylon fabric are bonded via an adhesive.

As the laminating film, a vinyl chloride film having a high plasticizer content, specifically, a plasticized vinyl chloride film containing a plasticizer in an amount of 40 parts by weight or more based on 100 parts by weight of a vinyl chloride resin is used. The film is suitably used, and when it is bonded to a skin material due to the flexibility of the film, a high-grade texture is obtained. further,
If the skin material is a woven fabric, water can pass therethrough, so that the film can provide waterproofness. In addition, when the adhesive applied to the film was dried and then bonded to a skin material while being heated to the bonding activation temperature, the film had a high melt tension at a high temperature, and thus showed excellent workability.

However, in recent years, the problem of environmental pollution has been emphasized, and the use of plasticized vinyl chloride containing chlorine has
It is seen as a problem in every field. In particular, when incinerating skin material waste such as bags containing a vinyl chloride film, problems such as generation of dioxin have occurred.

[0005] For this reason, recently, as a substitute for the vinyl chloride film, a woven fabric bonding film made of a polyolefin resin has been studied. However, the heat resistance of polyolefin resin films is lower than that of plasticized vinyl chloride films, and if the heat resistance is increased to be suitable for an adhesive processing line, the texture of the final product will be poor,
It was difficult to achieve a good balance between these properties. Also, the bonded product obtained by laminating a polyolefin-based resin film has a remarkable curl compared to that obtained by laminating a plasticized vinyl chloride film, making it difficult to perform secondary processing. was there.

To solve this problem, for example, Japanese Patent Application Laid-Open No. 6-927 discloses a layer composed mainly of a random copolymer of propylene and various α-olefins on both sides of a layer composed of an ethylene resin. Are laminated, an olefin resin film instead of a vinyl chloride film has been proposed.
However, when this olefin-based resin film is laminated with a fabric such as nylon, a large curl often occurs in a bonded product as compared with a vinyl chloride film, and secondary processing is a serious problem. Was.

Further, it has been difficult to realize the same degree of flexibility and texture as those of the existing vinyl chloride film bonded product using these olefin resin films instead of the vinyl chloride film. Further, the olefin-based resin film instead of the vinyl chloride film has low heat resistance and has difficulty in processing characteristics. In order to solve these problems, resins having more flexibility have been studied, but polyolefin resins having flexibility tend to have a low melting point and cannot maintain heat resistance in the heat bonding process. In addition, there has been a problem that the molten resin layer adheres to the transport roll, thereby reducing workability and quality.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to substitute a plasticized vinyl chloride film and laminate a cloth and a woven cloth to produce a bag covering material or the like. An object of the present invention is to provide a polyolefin-based film suitably used as a flooring material and a laminated film using the polyolefin-based film.

[0009]

The polyolefin film according to the first aspect of the present invention (hereinafter referred to as the first invention) is a polyolefin film comprising a single-layer or multi-layer polyolefin resin layer. Extrusion direction (M
D) Tensile modulus of elasticity is 10 to 80 MPa, stress at 5% elongation is 1 MPa or more, and resin extrusion direction (M
The stress ratio at the time of 5% elongation in D) and its perpendicular direction (TD) satisfies the following expression (1). 1 ≦ 5% elongation stress (MD) / 5% elongation stress (TD) ≦ 1.5 (1)

The polyolefin film according to the invention of claim 2 (hereinafter referred to as the second invention) is a polyolefin film comprising a single-layer or multi-layer polyolefin resin layer, wherein at least one surface layer has a melting point of 140.
C. or higher and a tensile modulus in the resin extrusion direction (MD) of 10 to 80 MPa, 5
% Elongation stress is 1 MPa or more, and 5% in the resin extrusion direction (MD) and its perpendicular direction (TD).
The stress ratio at the time of elongation satisfies the following expression (1). 1 ≦ 5% elongation stress (MD) / 5% elongation stress (TD) ≦ 1.5 (1)

[0011] The laminated film according to the third aspect of the present invention (hereinafter referred to as a third aspect of the invention) is characterized in that a fabric is laminated on at least one surface of the polyolefin-based film of the first or second aspect of the invention.

Hereinafter, the present invention will be described. The polyolefin-based film of the first invention is formed from a single-layer or multilayer polyolefin-based resin layer. Examples of the polyolefin resin include, for example, low-density polyethylene, propylene homopolymer, propylene random copolymer, propylene block copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene -Ethyl methacrylate copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer, copolymer of ethylene and α-olefin, and the like.

The tensile elastic modulus of the polyolefin film in the machine direction (MD) is limited to 10 to 80 MPa in consideration of the feeling and the workability. 5% in the flow direction (MD) of the polyolefin film
When the stress at the time of elongation becomes small, sufficient film strength cannot be obtained, so that it is limited to 1 MPa or more.

[0014] The resin extrusion direction (MD) and its perpendicular direction (T
The stress ratio to D) is preferably as close to 1 as possible.
The further away, the larger the amount of curl after lamination with the fabric, the greater the stress ratio at the time of 5% elongation in the film extrusion direction (MD) and its perpendicular direction (TD) from the viewpoint of curl prevention. It is necessary to satisfy (1). 1 ≦ 5% elongation stress (MD) / 5% elongation stress (TD) ≦ 1.5 (1)

As the method of forming the polyolefin-based film, a conventionally known method for forming a resin sheet or a film can be used, and examples thereof include an extrusion molding method using a T-die or inflation, and a calendar molding method. .

The thickness of the polyolefin film is as follows:
It is not particularly limited, and is appropriately determined depending on the application and the required texture.

The polyolefin film of the second invention is:
Formed from a single-layer or multilayer polyolefin-based resin layer,
At least one surface layer has a polypropylene resin layer having a melting point of 140 ° C. or higher.

The above-mentioned polyolefin resin layer can be obtained by the same molding method as in the first invention, using the same polyolefin resin as in the first invention.

The above-mentioned polypropylene-based resin layer is provided so as to form at least one surface layer, and when laminating a cloth to be described later, it is preferable that the polypropylene-based resin layer is laminated so as to be on the outside. If the melting point of the surface layer is lower than 140 ° C., the molten surface layer may adhere to the transport roll in the heating lamination process with the fabric.

The polyolefin-based film of the second invention comprises:
For the same reason as the polyolefin-based film of the first invention, the tensile modulus in the resin extrusion direction (MD) is 10
The stress at 5% elongation in the resin extrusion direction (MD) is limited to 1 MPa or more.

The stress ratio at the time of 5% elongation in the resin extrusion direction (MD) and the perpendicular direction (TD) of the resin of the polyolefin film is determined by the following formula for the same reason as the polyolefin film of the first invention. It is necessary to satisfy (1). 1 ≦ 5% elongation stress (MD) / 5% elongation stress (TD) ≦ 1.5 (1)

The laminated film of the third invention is characterized in that the first or second laminated film
On at least one side of the polyolefin film of the invention,
It consists of a laminate in which dough is laminated. For the lamination of the cloth, for example, a method in which an adhesive is applied to a polyolefin-based film and then pressure-bonded by passing between rolls is adopted, and the type of the adhesive can be appropriately selected depending on the cloth.

In order to improve the wettability of the polyolefin film, a corona treatment may be applied to the surface layer on which the fabric is laminated. If "stickiness" occurs on the corona treated surface, an anti-blocking agent may be added to the film. When abrasion resistance is required depending on the application, it is preferable to mix a slip agent or an anti-blocking agent on the opposite surface of the laminated surface layer.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention will be described below.

The following items (1) to (1) were used for the polyolefin-based films used in Examples 1 and 2 and Comparative Examples 1 to 3.
The performance evaluation of (4) was performed, and the results are shown in Table 1.

(1) Total Thickness The thickness of the polyolefin-based film at 20 points in the direction (TD) perpendicular to the resin extrusion direction (MD) was measured using a dial gauge, and the average value was determined.

(2) Tensile Modulus In accordance with JIS K 7127, the tensile modulus of the polyolefin film in the resin extrusion direction (MD) was measured.

(3) 5% elongation stress (MD) / 5% elongation stress (TD) In accordance with JIS K 7127, the extrusion direction (MD) of the resin of the polyolefin-based film and its perpendicular direction (T
The 5% elongation stress in D) was measured and calculated from the measured value.

(4) Melting Point of Surface Layer The melting point of the resin used for the surface layer of the polyolefin film was measured by DSC (differential scanning calorimeter).

[0030]

[Table 1]

(Example 1, Comparative Examples 1 and 2) As a polyolefin-based film, a polypropylene-based single-layer film shown in Table 1 was used, and one surface thereof was subjected to corona treatment, and then the solid content concentration was applied to the corona-treated surface. A 30% aqueous urethane adhesive was applied so as to have a coating amount of 25 g / m ² (wet). Next, after the adhesive-coated surface is overlaid on a nylon woven fabric and pre-dried, the film surface (the surface not coated with an adhesive)
Immediately after drying at 180 ° C. for 4 seconds, the mixture was passed through a metal embossing roll / rubber roll and pressed at a linear pressure of 50 N / cm to obtain a laminated film in which a nylon woven fabric was laminated on one surface of a polypropylene-based single-layer film.

(Example 2) As a polyolefin film, a three-layer film having a layer ratio of 1: 2: 1 in which the polypropylene resin film shown in Table 1 was used as both outer layers and a linear low-density polyethylene resin layer was used as an intermediate layer. And then subjected to corona treatment on one side, and then a solid content concentration of 30
% Aqueous urethane adhesive in an amount of 25 g / m ² (we
t) was applied. Next, after the adhesive-coated surface is overlaid on a nylon woven fabric and pre-dried, the film surface (non-adhesive-coated surface) is dried at 180 ° C. for 4 seconds, and immediately after passing through a metal embossing roll / rubber roll, a linear pressure Pressure was applied at 50 N / cm to obtain a laminated film in which a nylon woven fabric was laminated on one side of a three-layer film.

(Comparative Example 3) As a polyolefin-based film, a low-density polyethylene-based resin single-layer film shown in Table 1 was used, and one surface thereof was subjected to a corona treatment. The aqueous urethane adhesive was applied so as to have a coating amount of 25 g / m ² (wet). Next, after the adhesive-coated surface is overlaid on a nylon woven fabric and pre-dried, the film surface (non-adhesive-coated surface) is
Immediately after drying at 4 ° C. for 4 seconds, the mixture was passed between a metal embossing roll and a rubber roll and pressed at a linear pressure of 50 N / cm to obtain a laminated film having a nylon woven fabric laminated on one surface.

With respect to the laminated films obtained in Examples 1 and 2 and Comparative Examples 1 to 3, performance evaluations of the following items (5) to (8) were performed, and the results are shown in Table 2.

(5) Adhesive strength A laminated film cut to a width of 30 mm was used as a test piece, and 18
The 0-degree peel strength (between woven fabric and film) was measured at a tensile speed of 200 mm / min using a tensile tester.

(6) Texture Judgment was made based on the tactile sensation. A sample having the same degree of texture as the plasticized vinyl chloride film was evaluated as ○, and a film having a texture inferior to the plasticized vinyl chloride film was evaluated as ×.

(7) Amount of curl A square laminated film of 150 mm × 150 mm was used as a test piece, and a cut of 100 mm × 100 mm was made on the diagonal line of the test piece, and the cut was made to cross at the center of the test piece. Next, the test piece is placed on a smooth surface with the woven fabric facing down, four sides are fixed with adhesive tape, and then left at 23 ° C. for 16 hours, where the cut of the test piece crosses (vertexes of four triangles). Was measured, and the highest one was determined as the curl amount.

(8) Processability In preparing a laminated film, the adhesive-coated surface of the film is overlapped with a nylon woven fabric, and then the film surface (non-adhesive-coated surface) is dried at 180 ° C. for 4 seconds. When passing between the rubber rolls, the presence or absence of roll adhesion was visually observed, and judged according to the following criteria.・ No roll adhesion: ○ ・ Roll adhesion is transportable: △ ・ Roll is not transportable due to adhesion: ×

[0039]

[Table 2]

[0040]

The polyolefin film of the present invention is
As described above, it has the same flexibility, texture and heat resistance as the plasticized vinyl chloride film. Further, the laminated film of the present invention is obtained by laminating the above-mentioned polyolefin-based film and a woven fabric or a cloth, and has excellent adhesiveness and a small curl amount. It can be suitably used as a floor material.

 ──────────────────────────────────────────────────の Continued on the front page F-term (reference) 4F071 AA14 AA20 AA84 AF13 AF20 BC01 4F100 AK03A AK03B AK03C AK07A AK48 AK51G BA02 BA03 BA04 BA05 BA07 BA10A BA10B BA10D BA13 CB02 J02AJKK07 J02AJKB07 JL04 YY00A YY00B YY00C

Claims (3)

[Claims] 1. A polyolefin-based film comprising a single-layer or multi-layer polyolefin-based resin layer, wherein a tensile modulus in a resin extrusion direction (MD) is 10 to 80 MPa, 5%.
The stress at the time of elongation is 1 MPa or more, and the stress ratio at the time of 5% elongation in the resin extrusion direction (MD) and its perpendicular direction (TD) satisfies the following expression (1). Polyolefin film. 1 ≦ 5% elongation stress (MD) / 5% elongation stress (TD) ≦ 1.5 (1) 2. A polyolefin-based film comprising a single-layer or multilayer polyolefin-based resin layer, wherein at least one surface layer is formed of a polypropylene-based resin layer having a melting point of 140 ° C. or higher, in a resin extrusion direction (MD). Tensile modulus is 10-80MPa, stress at 5% elongation is 1MPa
A polyolefin-based film, wherein the stress ratio at the time of 5% elongation in the resin extrusion direction (MD) and its perpendicular direction (TD) satisfies the following formula (1). 1 ≦ 5% elongation stress (MD) / 5% elongation stress (TD) ≦ 1.5 (1) 3. A laminated film comprising a fabric laminated on at least one surface of the polyolefin-based film according to claim 1.