JP3114786B2 - Laminated film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a layer (A) and a layer (B).
Is composed of at least two layers, and both outer layers are composed of the (B) layer.
To a laminated film. More specifically, as a soft film comparable to soft vinyl chloride film and vinylon film, flexibility, tensile strength, low-temperature impact resistance,
The present invention relates to a laminated film having low-temperature heat sealability and the like.

[0002]

2. Description of the Related Art In recent years, a soft vinyl chloride film containing a plasticizer has been widely used as a soft film. However, soft vinyl chloride resins have social factors such as toxicity and transfer problems due to bleed-out of plasticizers and monomers, and acid rain problems due to generation of hydrogen chloride during incineration.

[0003]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide a film having excellent flexibility, low-temperature impact resistance, tensile strength and low-temperature heat sealability. In addition, the present invention is characterized by the above-described various uses, for example, food packaging, packaging films such as fiber packaging, medical applications such as infusion bags, metal protective films, base materials for adhesive tapes, in the civil engineering and construction fields. An object of the present invention is to provide a film suitably used as a building material film or the like. The inventors of the present invention have conducted intensive studies for the above-mentioned purpose, and as a result, a mixture of an amorphous polyolefin having a specific composition (hereinafter, referred to as “amorphous polyolefin”) and an ethylene-based resin in a predetermined ratio. A laminated film composed of a layer and an ethylene-based resin and / or crystalline polypropylene layer, wherein the film composed of the ethylene-based resin and / or crystalline polypropylene constitutes at least one outermost layer of the film. The present invention was found to be suitable.

[0004]

According to the present invention, (A)
Propylene and / or butene-1 component content of 50
20 % to 100% by weight (excluding 100% by weight) of an amorphous polyolefin of 80 % by weight or more and 80 to 80 % by weight of an ethylene-based resin.
(A) layer comprising a resin composition containing 0% by weight (excluding 0% by weight ), and (B) an ethylene-based resin and / or
Or a film in which a layer (B) made of crystalline polypropylene is laminated on at least two layers, and both outer layers are (B)
A polyolefin-based laminated film composed of layers is provided.

Hereinafter, the present invention will be described in detail. The amorphous polyolefin used in the layer (A) of the present invention includes:
Any amorphous olefin polymer having a propylene and / or butene-1 content of 50% by weight or more may be used. For example, amorphous polypropylene or polybutene-1
Alternatively, a copolymer of propylene or butene-1 and another α-olefin can be used.

The above-mentioned amorphous polyolefin refers to a boiling n-
Heptane insoluble content, that is, Soxhlet extracted insoluble content with boiling n-heptane is 70% by weight or less, preferably 6% by weight.
0% by weight or less. If the boiling n-heptane insoluble content is more than 70% by weight, the ratio of the amorphous portion becomes small, and the film obtained cannot have the desired flexibility. The amorphous polyolefin of the layer (A) preferably has a melt viscosity (at 190 ° C.) of 1,000 to 100,000 cps, more preferably 1,500 to 50,000 cps. Melt viscosity (1
(90 ° C.) is less than 1,000 cps, the mechanical strength is reduced.

As the above-mentioned amorphous polypropylene, atactic polypropylene which is a by-product during the production of crystalline polypropylene may be used, or may be produced from raw materials for the purpose. At this time, a copolymer of propylene or butene-1 and another α-olefin can be produced from a raw material so as to contain a predetermined propylene or butene-1 component and used. In addition, when producing for the purpose, for example,
It can be obtained by polymerizing a raw material monomer in the presence of hydrogen or in the absence of hydrogen using a titanium-supported catalyst supported on magnesium chloride and triethylaluminum. From the viewpoint of stability of raw material supply and stability of quality,
It is preferred to use the desired amorphous polyolefin produced for the purpose. Also, if there are applicable suitable commercial products,
A commercially available product can be appropriately selected and used.

As the amorphous polyolefin of the layer (A) of the present invention, specifically, polypropylene, propylene / ethylene copolymer, propylene / butene-1 copolymer having predetermined characteristics such as the above-mentioned propylene content. , Propylene / butene-1 / ethylene-3 terpolymer, propylene / hexene-1 / octene-1 / 3 terpolymer, propylene / hexene-1 / 4-methylpentene-1 / 3 terpolymer, etc. Amorphous polyolefin containing propylene component as a main component. Polybutene-1, butene-1 / ethylene copolymer, butene-1 / propylene copolymer, butene-1 / propylene / ethylene terpolymer having predetermined properties such as the above butene-1 component content Butene-1 component such as butene-1, hexene-1, octene-1, terpolymer and butene-1, hexene-1, 4-methylpentene-1, terpolymer. Amorphous polyolefins are also included. When the amorphous polyolefin is a propylene / ethylene copolymer, the ethylene component content is preferably 0 to 30% by weight, more preferably 1 to 20% by weight. When the ethylene content is more than 30% by weight, the obtained film becomes too soft.

When the amorphous polyolefin of the layer (A) of the present invention is a propylene / butene-1 copolymer, the copolymer mainly composed of propylene and the copolymer mainly composed of butene-1 are used. However, each of them has a large tensile elongation and is suitably used as the amorphous polyolefin of the layer (A). Specifically, for example, a commercially available product such as REXTAC of Rexene of the United States can be used.

The ethylene resin used in the layer (A) of the present invention includes low-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene, medium-density polyethylene,
High-density polyethylene and copolymers based on ethylene, that is, ethylene and olefins such as propylene, butene, pentene, hexene, heptene, octene, vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, and acrylic acid It refers to a copolymer or a multi-component copolymer with one or more comonomers selected from unsaturated carboxylic esters such as ethyl, methyl methacrylate and ethyl methacrylate, and ionomer resins thereof. Of course, two or more polymers or copolymers may be used as a mixture.

Further, the amorphous polyolefin and / or ethylene resin of the layer (A) in the present invention comprises:
Modified ones can be used. The amorphous polyolefin and / or ethylene resin, for example,
Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid and / or their esters, acid anhydrides, derivatives thereof such as metal salts, unsaturated amides, amino acids It can be used after being modified with a compound, glycidyl methacrylate, hydroxy methacrylate or the like. Among these modified products, those modified with maleic anhydride and itaconic anhydride are preferably used, and those modified with maleic anhydride are more preferably used.

In the present invention, the method of blending the amorphous polyolefin of the layer (A) with the ethylene resin is not particularly limited, and may be any of the methods commonly used in the production of conventional polypropylene compositions, for example, Heat melting and kneading can be performed using a kneader such as a kneader, a Banbury mixer, a roll, or a single or twin screw extruder. Also,
In the present invention, various additives may be added to the resin composition constituting the layer (A) and the crystalline polypropylene and / or ethylene resin constituting the layer (B), if desired.
Fillers such as lubricants, antiblocking agents, tackifiers, antistatic agents, antifogging agents, antioxidants, nucleating agents and the like can be added. In particular, nonionic surfactants such as polyglycerin fatty acid ester, sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene fatty acid amide, and fatty acid alkanolamide can be used alone or in combination as an antifogging agent. Further, other thermoplastic resins, thermoplastic elastomer rubbers and the like can be blended as required, and these can be crosslinked.

The resin composition of the layer (A) of the present invention comprises the above-mentioned amorphous polyolefin and an ethylene resin, and contains the amorphous polyolefin in an amount of 20 to 100% by weight (100% by weight).
) , Preferably 25 to 100 % by weight (100 % by weight)
%) . If the amount of the amorphous polyolefin is less than 20% by weight, sufficient flexibility cannot be obtained.

The ethylene resin used in the layer (B) of the present invention includes low-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene, medium-density polyethylene,
High-density polyethylene and copolymers based on ethylene, that is, ethylene and olefins such as propylene, butene, pentene, hexene, heptene, octene, vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, and acrylic acid It refers to a copolymer or a multi-component copolymer with one or more comonomers selected from unsaturated carboxylic esters such as ethyl, methyl methacrylate and ethyl methacrylate, and ionomer resins thereof. Of course, two or more polymers or copolymers may be used as a mixture. In addition, a modified material similar to the layer (A) can be used.

Among these ethylene resins, those having a Shore D hardness at 23 ° C. of 50 or less are particularly preferred from the viewpoint of the flexibility of the entire laminated film. Shore D hardness is 50
Examples of the following include low-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ionomer resin, and the like.

The crystalline polypropylene used in the layer (B) of the present invention includes polypropylene which is generally commercially available for extrusion molding, injection molding, blow molding and the like, and refers to boiling n-heptane-insoluble isotactic polypropylene. . In this case, a propylene homopolymer may be used, or a copolymer of isotactic polypropylene having stereoregularity and another α-olefin may be used.

The α-olefin used for copolymerization with crystalline polypropylene includes α-olefins having 2 to 8 carbon atoms.
-Olefins such as ethylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1 and the like are preferred. Of these, ethylene or butene-1 is particularly preferred.

In the present invention, the above-mentioned crystalline polypropylene is preferably a propylene homopolymer, a random copolymer or block copolymer of propylene containing 30% by weight or less, preferably 1 to 25% by weight of an ethylene component, and ethylene. , Butene-1 containing 20% by weight or less of propylene, butene-1 random copolymer or block copolymer. Among these, a copolymer of ethylene or butene-1 and propylene is particularly preferable from the application of the resin composition of the present invention such as a film or sheet.

The laminated film of the present invention is usually formed by alternately laminating the above-mentioned layers (A) and (B). The number of layers (A) and (B) to be laminated is not particularly limited, but is composed of at least two layers,
That is, the layers forming both outer surfaces are constituted by the layer (B). For example, (B) / (A) / (B),
It can be configured by a combination such as (B) / (A) / (B) / (A) / (B).

In the present invention, the layer (A) contributes to imparting flexibility to the whole film, and can improve low-temperature brittleness and molding processing stability of the film by containing an ethylene resin. On the other hand, the layer (B) contributes to the flexibility and the low-temperature heat sealability of the film, and also prevents the surface adhesion of the layer (A). Also,
In the laminated film of the present invention, another thermoplastic resin layer, for example, nylon, eval, polyester or the like for providing a gas barrier may be inserted between the layer (A) and the layer (B).

In the present invention, the thickness of each layer constituting the laminated film is not particularly limited, and can be arbitrarily selected. Usually, each layer is about 2-1000 μm
Formed in the range. Further, the ratio of the thickness of the layer (A) to the thickness of the layer (B) is not particularly limited. Preferably, as described above, layer (A) contributes to the flexibility of the film,
Since the layer (B) fulfills the function of preventing surface tackiness, the layer (A) is constituted so as to account for 20 to 99%, more preferably 30 to 95% of the total thickness of the laminated film.

The method for producing the laminated film of the present invention is not particularly limited. For example, a coextrusion lamination method, a lamination method, a dry lamination method, or the like can be used. Of these, a co-extrusion lamination method in which melt bonding is performed is preferable. Specifically, for example, melt extruding using an extruder suitable for the number of laminations, after laminating in a molten state by a known method such as a T-die method or an inflation method, a cooling roll,
A laminated film can be formed by using a method of cooling with water or air.

The laminated film of the present invention can be subjected to a surface treatment in order to improve printability, lamination, and adhesive application properties. Examples of surface treatment methods include corona discharge treatment, plasma treatment, flame treatment, and acid treatment.
In the present invention, any method can be used. Plasma treatment, flame treatment and corona discharge treatment are preferred because continuous treatment is possible and can be easily carried out before the winding step in the film production process, and among these, corona discharge treatment is preferred in terms of simplicity. Most preferred. In addition, this laminated film is uniaxially or biaxially stretched,
Compressed air, vacuum forming, etc. can also be used.

The laminated film of the present invention is laminated, cooled and solidified as described above, subjected to the above-mentioned treatment as required, and then wound up to the next step, for example, printing, laminating, and adhesive. It can be used for the intended use through secondary processing steps such as coating and heat sealing. Although the laminated film of the present invention is applicable and useful for various applications by itself, it is further laminated with polyester, nylon, stretched polypropylene film, etc., and has functions such as mechanical strength, gas barrier properties, and printing performance. It can also be improved.

[0025]

EXAMPLES AND COMPARATIVE EXAMPLES Hereinafter, according to the examples of the present invention,
This will be described in detail. However, the present invention is not limited by the following examples. Various tests in Examples and Comparative Examples other than the present invention were performed by the following methods. 1) Method for measuring resin properties Density ASTM-D1505 Melt viscosity Measurement temperature 190 ° C (Rotary viscometer manufactured by Brookfield) 2) Method for measuring film properties Tensile properties Tensile test was performed according to ASTM-D882, and (1) Tensile strength (Kg / cm ² ), (2) tensile elongation (%),
(3) Evaluation was made on three items of tensile modulus (kg / cm ² ). Haze (%) Performed according to ASTM-D1003. Elementaldorf tear strength (kg / cm) This was performed according to JIS-Z1702. Dart Impact (g / 26 in) ASTM-D1709 Heat Sealing Temperature Heat sealing was performed at a predetermined temperature, and the minimum temperature at which the adhesive strength to break the material was obtained was defined as the heat sealing temperature.

Example 1 [Preparation of (A) Layer Resin Composition] As the resin composition constituting the (A) layer, the density was 0.86 g / cm ³ , the propylene content was 87% by weight, and the ethylene content was 13% by weight. Amorphous polyolefin having a melt viscosity (190 ° C.) of 9,000 cps (trade name: REXTAC RT258, manufactured by Lexen Corporation)
5), density 0.918 g / cm ³ , MI (190 ° C.) =
3.0 linear low density polyethylene (LLDPE)
A resin composition prepared by mixing at a weight ratio of T2585 / LLDPE = 30/70 and melt-kneading at a temperature of 200 ° C. was used. [Molding of laminated film] The resin composition prepared above was applied to the layer (A), and the density was 0.92 g / cm ³ and the MI (1
LLDPE (manufactured by Ube Industries, Ltd., trade name FA120N) = 1.0 g / 10 min (90 ° C.) was used for the layer (B).
As the outer layer / intermediate layer / inner layer, (B) / (A) / (B) had the thickness ratio shown in Table 1, and each of the three layers was independent.
Using a single extruder and a three-layer die connected to this, after co-extrusion of the melted three layers, the air ring and the water-cooled sizing ring were quenched, blow-down molded into a tubular film, and immediately wound up. A three-layer laminated film having the total thickness shown was obtained. The properties of the obtained three-layer laminated film were measured, and the results are shown in Table 2. Table 1 shows the film composition.

Example 2 The layer (B) had a density of 0.895 g / cm ³ and MI (190
° C) = 3.0 g / 10 min ultra low density polyethylene (VL
DPE) (Ube Industries, Ltd., trade name Z522) was used in the same manner as in Example 1 to obtain a three-layer laminated film having the entire thickness shown in Table 1. The properties of the obtained three-layer laminated film were measured, and the results are shown in Table 2. Table 1 shows the film composition.

Example 3 As the resin composition constituting the (A) layer, the same amorphous polyolefin as in Example 1 was used, and the density was 0.93 g instead of linear low density polyethylene (LLDPE).
/ Cm ³ , MI (190 ° C.) = 2.0 g / 10 min, and an ethylene / vinyl acetate copolymer (EVA) (trade name V215, manufactured by Ube Industries, Ltd.) having a vinyl acetate content of 15% by weight. The three-layer film having the entire thickness shown in Table 1 was obtained in the same manner as in Example 1 except that the layer (B) used the ethylene / vinyl acetate copolymer (trade name V215) used for the layer (A). Was. The properties of the obtained three-layer laminated film were measured, and the results are shown in Table 2. Table 1 shows the film composition.

Example 4 As the resin composition constituting the layer (A), the same amorphous polyolefin as in Example 1 was used, and the density was 0.92 g instead of linear low density polyethylene (LLDPE).
/ Cm ³ , MI (190 ° C.) = 2.0 g / 10 min. Low-density polyethylene (trade name: F20, manufactured by Ube Industries, Ltd.)
0) was used. The layer (B) was prepared in the same manner as in Example 1 except that the low-density polyethylene used for the layer (A) was used.
Was obtained. The properties of the obtained three-layer laminated film were measured, and the results are shown in Table 2.
Table 1 shows the film composition.

Example 5 The resin used for the layer (B) was 0.91 g / cm ³ in density and melt flow rate (MFR) (230 ° C.) = 9 g / 10
And a polypropylene having a melting point of 138 ° C. (trade name: RF395, manufactured by Ube Industries, Ltd.) and a density of 0.92 g / c.
m ³ , MI (190 ° C.) = 1.0 g / 10 min, melting point 12
5 ° C LLDPE (Ube Industries, Ltd., trade name FA1)
20N), the inner layer was made of LLDPE, and the outer layer was made of PP, in the same manner as in Example 1 except that the total thickness shown in Table 1 was 3%.
A layer laminated film was obtained. The properties of the obtained three-layer laminated film were measured, and the results are shown in Table 2. Table 1 shows the film composition.

Comparative Example 1 As a film raw material, a density of 0.92 g / cm ³ and MI (1
90 ° C.) = 1.0 g / 10 min linear low density polyethylene (LLDPE) (manufactured by Ube Industries, Ltd., trade name FA120)
N), a tube-shaped film was extruded from a ring-shaped die by a water-cooled blown film forming apparatus, and immediately after being cooled with water, wound up into a 60 μm thick LLDPE.
A single layer film was obtained. The properties of the obtained film were measured, and the results are shown in Table 2.

Comparative Example 2 As a film raw material, a density of 0.92 g / cm ³ , MI
(190 ° C.) = 2 g / 10 min, except that low-density polyethylene (manufactured by Ube Industries, Ltd., trade name: F200) was used.
An LLDPE single layer film was obtained in the same manner as in Comparative Example 1.
The properties of the obtained film were measured, and the results are shown in Table 2.

Comparative Example 3 As a film raw material, a density of 0.93 g / cm ³ and MI (1
Comparative Example 1 except that an ethylene / vinyl acetate copolymer (EVA) (trade name: V215, manufactured by Ube Industries, Ltd.) having a vinyl acetate content of 15% by weight (2.0 ° C.) = 2.0 g / 10 min. Similarly, an EVA single layer film was obtained. The properties of the obtained film were measured, and the results are shown in Table 2.

Comparative Example 4 As a film raw material, a density of 0.91 g / cm ³ , a melt flow rate (MFR) (230 ° C.) = 9 g / 10 minutes,
A single-layer PP film was obtained in the same manner as in Comparative Example 1, except that crystalline polypropylene (PP) having a melting point of 138 ° C. (trade name: RF395, manufactured by Ube Industries, Ltd.) was used. The properties of the obtained film were measured, and the results are shown in Table 2.

[0035]

[Table 1]

[0036]

[Table 2]

From the above Examples and Comparative Examples, the three-layer laminated film comprising the (A) layer and the (B) layer of the present invention is more excellent in flexibility and mechanical strength than the film of Comparative Example. It can be seen that the balance is achieved and low-temperature heat sealing is possible.

[0038]

The laminated film of the present invention is a flexible film having excellent flexibility, mechanical strength and low-temperature heat sealability, and is applicable to various uses in place of a soft vinyl film which has become a social problem due to environmental pollution. can do.

Continuation of the front page (56) References JP-A-6-927 (JP, A) JP-A-5-237977 (JP, A) JP-A-61-106245 (JP, A) JP-A-61-110550 (JP, A) , A) JP-A-5-77371 (JP, A) JP-A-58-171922 (JP, A) JP-A-64-1535 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B32B 1/00-35/00

Claims (5)

(57) [Claims] (A) propylene and / or butene
Resin containing 20 to 100% by weight (excluding 100% by weight) of an amorphous polyolefin having a component content of 50% by weight or more and 80 to 0% by weight (excluding 0% by weight ) of an ethylene resin A film in which the (A) layer composed of the composition and the (B) layer composed of the ethylene resin and / or the crystalline polypropylene are laminated in at least two layers, and both outer layers are composed of the (B) layer Polyolefin-based laminated film. 2. The polyolefin-based laminated film comprises (A)
A three-layer laminated film consisting of a layer and a layer (B)
The polyolefin laminate according to claim 1, wherein
Film. 3. The method of claim 1, wherein the amorphous polyolefin is a propylene component.
Amorphous polyolefin with a content of 50% by weight or more
The polyolefin according to claim 1, wherein:
Thin laminated film. 4. An ethylene resin of the layer A has a density of 0.918.
g / cm ³ ethylene-based resin of ~0.93g / cm ³ and
/ Or the ethylene resin of the layer B has a density of 0.895 g
/ Cm ³ ~ 0.93g / cm ³ ethylene resin
The polyolefin-based composition according to claim 1, wherein
Laminated film. 5. The method according to claim 1, wherein the ethylene resin of the layer A is a low-density polyethylene.
Ren, linear low density polyethylene and / or ethylene
・ Vinyl acetate copolymer, ethylene resin of layer B is low density polyethylene, ultra low density
Degree polyethylene, linear low density polyethylene and / or
Is an ethylene-vinyl acetate copolymer.
The polyolefin-based laminated fill according to any one of claims 1 to 4.
M