JPH07314623A - Polyolefinic shrink laminated film and production thereof - Google Patents

Abstract

PURPOSE:To provide a polyolefinic shrink laminated film improved in transparency, gloss and haze and excellent in flexibility and heat shrinkability and adaptable to various uses in place of a soft polyvinyl chloride film becoming a social problem in environmental pollution. CONSTITUTION:A polyolefinic shrink laminated film is an oriented obtained by laminating at least two layers, that is, a layer (A) composed of a resin compsn. containing 20-100wt.% of amorphous polyolefin with propylene and/or butene-1 content of 50wt.% or more and 80-0wt.% of an ethylenic resin and a layer (B) composed of crystalline polypropylene and/or an ethylenic resin and characterized by that a single outer layer or both outer layers are constituted of the layer (B).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a uniaxially or biaxially stretched film of a polyolefin-based laminated film having at least two layers. More specifically, the present invention relates to stretch packaging of soft vinyl chloride film, stretch shrink packaging, and films that can be substituted for shrink packaging.

[0002]

2. Description of the Related Art Conventionally, transparent stretch or shrink films have been used for packaging fresh foods, stationery and the like. This film is a vinyl chloride film (hereinafter abbreviated as polyvinyl chloride film), has good transparency, is suitable for packaging machines, and is widely used. However, the soft PVC film contains a large amount of plasticizer (about 30% by weight), and when packaged with this film, the plasticizer migrates to food, contaminates food, and has a large amount of moisture permeation. Will be lost. Moreover, when this film is incinerated, hydrogen chloride gas is generated, which causes many environmental problems such as environmental pollution.

Therefore, many polyolefin films have been developed as substitute films for the vinyl chloride film. As a soft film instead of a vinyl chloride film, ethylene-vinyl acetate copolymer (EVA), low density polyethylene (LDPE), linear low density polyethylene (LLDP)
E), polypropylene film (PP) and the like. For example, in stretch packaging in which commercial wrap films are used, ethylene-
When an unstretched film of vinyl acetate or LLDPE is used, when the film is stretched and stretch-wrapped, the film causes necking, resulting in uneven thickness of the film. Also, the elastic recovery rate of the film is poor, and a film package with a sufficient finish cannot be obtained. Further, when this film is shrink-wrapped, there is a defect that a sufficient heat shrinkage cannot be obtained because it is non-oriented. In order to improve this drawback, if a single film of EVA or LLDPE is biaxially stretched, the film is easily broken, so that a good biaxially stretched film cannot be obtained at present.

A polypropylene film can be easily biaxially stretched, and the film has good transparency and relatively good shrink characteristics. However, due to the high heat-sealing temperature and the hardness of the film, there are major drawbacks for commercial wrap films and shrink wrapping films. JP-A-05-773 discloses that these drawbacks are improved by a polyolefin-based laminated film system.
No. 71 discloses a flexible film having a large elongation, which is a film obtained by laminating a layer containing at least one amorphous polyolefin and a layer of crystalline polypropylene.
However, this film is an unstretched film and cannot be said to be a sufficient film for shrink wrapping.

As described above, polyolefin-based films have been studied as alternatives to vinyl chloride films, but these films are inferior to vinyl chloride films in optical properties such as transparency, haze and gloss, and shrinkage properties, and are also not suitable for packaging machines. Since it is considerably inferior to PVC film, it is the current situation that substitution cannot proceed. An object of the present invention is to develop a polyolefin film having the characteristics of a vinyl chloride film that solves the above-mentioned drawbacks.

[0006]

Means for Solving the Problems The inventors of the present invention have made extensive studies and solved the above problems by stretching a laminated film having a specified constitution. The present invention comprises 20 to 100% by weight of (A) an amorphous polyolefin having a propylene and / or butene-1 component content of 50% by weight or more.
And (B) layer made of a crystalline polypropylene and / or an ethylene resin (B) made of a resin composition containing 80 to 0% by weight of an ethylene resin are laminated in at least two layers. It is a stretched film and is a polyolefin-based shrink laminated film in which one outer layer or both outer layers is composed of the layer (B).

The present invention will be described in detail below. The amorphous polyolefin (hereinafter referred to as “amorphous polyolefin”) used in the layer (A) of the present invention has a propylene and / or butene-1 content of 50% by weight.
Any amorphous olefin polymer as described above may be used.
For example, amorphous polypropylene or polybutene-1 or a copolymer of propylene or butene-1 and other α-olefin can be used.

The above-mentioned amorphous polyolefin means boiling n-
Heptane insoluble matter, that is, Soxhlet extractable insoluble matter by boiling n-heptane is 70% by weight or less, preferably 6
It is 0% by weight or less. When the boiling n-heptane insoluble content is more than 70% by weight, the ratio of the amorphous portion is small, and it is not possible to impart the desired sufficient flexibility to the obtained film. The amorphous polyolefin of the layer (A) has a melt viscosity (190 ° C.) of 1,000.
100 to 100,000 cps, preferably 3,000 to 50,
000 cps and density 0.85-0.90 g / cm
A resin having the characteristics of ³ is particularly preferable.

As the amorphous polypropylene, atactic polypropylene produced as a by-product during the production of crystalline polypropylene may be used, or the target polypropylene may be produced from raw materials and used. 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. Also, when producing for the purpose, for example,
It can be obtained by polymerizing a raw material monomer in the presence / 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 preferable to use a predetermined amorphous polyolefin produced by the purpose. Also, if there is a suitable suitable commercial product,
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 component content. , Propylene / butene-1 / ethylene-3 terpolymer, propylene / hexene-1 / octene-1 / 3 terpolymer, propylene / hexene-1 / 4-methylpentene-1 / 3 terpolymer, etc. The amorphous polyolefin whose main component is the propylene component of Further, polybutene-1, butene-1 / ethylene copolymer, butene-1 / propylene copolymer, butene-1 / propylene / ethylene-3 terpolymer having predetermined characteristics such as the butene-1 component content. Butene-1 component such as butene-1, hexene-1, octene-1-3 terpolymer, butene-1, hexene-1,4-methylpentene-1-3 terpolymer is the main component. Amorphous polyolefins are also included. When the amorphous polyolefin is a propylene / ethylene copolymer, the content of ethylene component is 0 to 30% by weight, preferably 1 to 20% by weight. The ethylene content is
If it exceeds 30% by weight, the resulting film becomes too soft.

When the amorphous polyolefin of the layer (A) of the present invention is a propylene / butene-1 copolymer, a copolymer containing propylene as a main component and a copolymer containing butene-1 as a main component are used. However, each has a large tensile elongation and is suitably used as the amorphous polyolefin of the layer (A).

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 a copolymer containing ethylene as a main component. , That is, olefins such as ethylene and propylene, butene, pentene, hexene, heptene, octene,
One selected from vinyl acetate, vinyl propionate, and other vinyl esters, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and other unsaturated carboxylic acid esters, and their metal salts (ionomer resins) Alternatively, it is a copolymer or multi-component copolymer with two or more comonomers. Of course, two or more polymers or copolymers may be mixed and used.

Furthermore, the amorphous polyolefin and / or ethylene resin of the layer (A) in the present invention is
A modified product can be used. The above-mentioned amorphous polyolefin or ethylene-based resin, for example, unsaturated carboxylic acid such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid and / or their esters, acid anhydrides, metals It can be used after being modified with a derivative thereof such as a salt, an amide of an unsaturated compound, an amino compound, glycidyl methacrylate, hydroxymethacrylate and the like. Among these modified products, those modified with maleic anhydride or 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 (A) and the ethylene resin in the layer (A) is not particularly limited, and is a method conventionally used in the conventional method for producing a polypropylene composition, for example, It can be carried out by heating, melting and kneading using a kneader, a Banbury mixer, a kneader such as a roll, or a single-screw or twin-screw extruder. In the present invention, the resin composition constituting the layer (A) and the crystalline polypropylene constituting the layer (B) and /
Alternatively, various additives and fillers such as a lubricant, an antiblocking agent, a tackifier, an antistatic agent, an antifogging agent, an antioxidant, and a nucleating agent can be added to the ethylene resin as desired. In particular, as the antifogging agent, 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. Furthermore, other thermoplastic resins, thermoplastic elastomers, rubbers and the like can be blended as necessary, and these can be crosslinked and blended.

The resin composition for the layer (A) of the present invention comprises the above-mentioned amorphous polyolefin alone or the above-mentioned amorphous polyolefin and an ethylene resin, and the amorphous polyolefin is contained in an amount of 20 to 100% by weight, preferably. It can be obtained by blending so as to be 25 to 100% by weight. If the amorphous polyolefin is less than 20% by weight, sufficient flexibility cannot be obtained.

The crystalline polypropylene used in the layer (B) of the present invention comprises a propylene homopolymer and an ethylene component of 3%.
Random copolymer of propylene, ethylene or block copolymer containing 0% by weight or less, preferably 1 to 25% by weight, propylene / butene-1 random copolymer containing 20% by weight or less of butene-1, or Block copolymers may be mentioned. Of these, a copolymer of ethylene or butene-1 and propylene is preferable. In particular,
In order to bring out the characteristics of the soft film, it is preferable to use a propylene-based random copolymer having a melting point of 150 ° C. or lower.

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,
Copolymers based on high-density polyethylene and ethylene, that is, ethylene and olefins such as propylene, butene, pentene, hexene, heptene and octene, vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, acrylic acid A copolymer or multi-component copolymer with one or two or more comonomers selected from ethyl, methyl methacrylate, unsaturated carboxylic acid esters such as ethyl methacrylate, and metal salts thereof (ionomer resins) is used. Say. Of course, two or more polymers or copolymers may be mixed and used. Further, it is also possible to use the modified one as in the case of the layer (A).

Among these ethylene resins, those having a Shore D hardness at 23 ° C. of 50 or less are particularly preferable from the viewpoint of flexibility of the whole 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, and ionomer.

When the crystalline polypropylene and the ethylene resin containing a polar group are blended in the layer (B) of the present invention, the blending ratio is not particularly limited, but it is 98: from the viewpoints of compatibility of both and transparency. It is preferably from 2 to 50:50, more preferably from 95: 5 to 60:40. Further, the concentration of the polar group-containing monomer contained in the polar group-containing ethylene-based resin or the concentration of the graft-modified acid or the like exerts a wetting effect and an adhesive effect on the film surface, and thus the resin of the entire (B) layer. 0.0 for layers
The amount is preferably 1 to 30% by weight, more preferably 0.05 to 20% by weight.

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

In the present invention, the layer (A) contributes to impart flexibility to the entire film. Further, by containing the ethylene-based resin, it is possible to provide the film with excellent tear strength and low-temperature brittleness. On the other hand, the layer (B) contributes to the flexibility and low temperature heat sealability of the film, and prevents the surface tackiness of the layer (A). Further, in the laminated film of the present invention, another thermoplastic resin layer may be inserted between the (A) layer and the (B) layer, for example, nylon, EVAL, polyester or the like for providing a gas barrier.

In the present invention, the thickness of each layer constituting the laminated and stretched film is not particularly limited and can be arbitrarily selected. Usually, each layer is about 2-30
It is formed in the range of 0 μm. Further, the thickness ratio of the (A) layer and the (B) layer is not particularly limited. Preferably, as described above, the layer (A) contributes to the flexibility of the film, and the layer (B) functions to prevent surface tackiness.
The layer (A) is constituted so as to be 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 laminating method, a lamination method, a dry lamination method or the like can be used. Of these, the coextrusion laminating method in which melt adhesion is performed is preferable. Specifically, melt extrusion is performed using an extruder suitable for the number of laminated layers, and after laminating in a molten state by a known method such as a T-die method or an inflation method, a method of cooling with a cooling roll, water cooling or air cooling is used, It can be a laminated film. Further, in this case, in order to make the best use of the characteristics of the film of the layer (B), after stretching the layer (B) first,
It can also be laminated with layers.

The method for stretching the laminated film of the present invention is not particularly limited. For example, the laminated film may be sequentially biaxially stretched by a tenter, simultaneously biaxially stretched, or uniaxially stretched in the machine direction or the transverse direction. Alternatively, the inflation method may be performed by simultaneous biaxial stretching. Furthermore, after stretching, it may be heat-fixed at a predetermined temperature if necessary.

In the present invention, by using the ethylene-based resin for both outermost layers and the (A) layer for the central layer, the biaxial stretching of the ethylene-based resin, which has hitherto been impossible, can be facilitated. Generally, it is difficult to biaxially stretch a film made of an ethylene resin alone. Therefore, in the case of using an ethylene resin alone, a biaxially stretched film can be obtained by irradiating an unstretched film with radiation to partially crosslink it and then stretching at a high temperature (around the melting point). However, this film has a poor heat-sealing property, and it has been desired that the film can be biaxially stretched without cross-linking the ethylene resin. As described above, when the layer (A) is used as the central layer and the ethylene resin is used as the surface layer, biaxial stretching is possible without cross-linking, and more preferably, biaxial stretching at low temperature is possible. discovered. Thus, biaxial stretching became possible in a wide stretching temperature range. In the present invention, the biaxial stretching temperature range is from 40 ° C, preferably from 50 ° C to B.
Good stretching was possible up to a temperature 10 ° C lower than the melting point of the resin used for the layer. Regarding the physical properties of the laminated stretched film, the tensile strength is 2.5 kg / mm ² or more, preferably 3.0 kg / mm
² or more, the tensile elastic modulus is 5.0 kg / mm ^{2 to} 50 kg
/ Mm ^2, preferably in the range of polyolefin heat-shrinkable laminated film having a physical property value in the range of 10～40Kg / mm ² is preferred. The tensile strength of the laminated stretched film is 2.
When the value is less than 5 kg / mm ² , the film is easily broken. Therefore, in the case of stretch wrapping, it is necessary to increase the film thickness so as not to tear the film. On the other hand, when the elastic modulus is less than 5 kg / mm ² , the film is not stiff, and the packaging operation is difficult.
In particular, the problem occurs that it does not apply to automatic packaging machines.
When the elastic modulus of the film is more than 50 kg / mm ² , the film becomes hard and the elongation of the film also becomes small. Further, when shrink-wrapping a fresh food or the like, the shrinkage stress becomes large, making it difficult to maintain the shape of a soft food. The thickness of the central layer (A) of this laminated stretched film is
Although not particularly limited, the stretchability is particularly good in the range of 20 to 80% by weight. The stretching ratio is preferably 2 to 60 times in terms of area ratio.

In particular, in order to obtain a film having good heat shrinkability, it is necessary to orient the film sufficiently by stretching. For that purpose, the stretching temperature of the film is a very important factor. A stretching temperature of 40 ° C. to a temperature 10 ° C. lower than the melting point (Tm) of the resin of the layer (B), preferably (Tm−1).
When stretched in the temperature range of 5) ° C., the laminated film was sufficiently oriented and a stretched film having good heat shrinkability was obtained.
Since the tensile elastic modulus of this film does not become so large even when stretched due to the amorphous polyolefin used for the central layer (A), the elastic modulus of the laminated stretched film also shows a relatively low value. The tensile strength is considerably increased by stretching as compared with the unstretched film. It can be said that this laminated stretched film is a heat-shrinkable film having flexibility and stretchability and having stretchability. When this laminated unstretched film is stretched under a stretching condition at a stretching temperature close to the Tm of the resin of the layer (B), the orientation of the layer B becomes insufficient and the film becomes a film having a small heat shrinkage rate. Further, when the film is stretched at a temperature of Tm or higher, it is partially melted during the stretching and the film is broken. Further, at a stretching temperature of 40 ° C. or less, the film loses elongation and breaks during stretching.

[0027]

EXAMPLES AND COMPARATIVE EXAMPLES Examples of the present invention will be described in detail below. However, the present invention is not limited to the following examples. Various tests in the following examples and comparative examples of the present invention were conducted by the following methods. 1) Resin property measuring method Density ASTM D1505 Melt viscosity measuring temperature 190 ° C. (Rolling viscometer manufactured by Brookfield) 2) Film physical property measuring method Tensile property Tensile test was conducted according to ASTM D-882, and (i) Tensile strength. (Kg / mm ² ) (ii) Tensile elongation (%) (iii) Tensile elastic modulus (kg / mm ² ) The three items were evaluated. Haze Haze (%) It carried out according to ASTM D1003. Thermal shrinkage was performed according to ASTM D2732. Heat shrinkage stress (Ube method) Heat shrinkage stress measuring device: Measured with a DN type stress tester (manufactured by Nichiri Kogyo).

Example 1 [Preparation of resin composition for layer (A)] As a resin composition constituting the layer (A), the density was 0.86 g / cm ³ , the propylene content was 87% by weight, and the ethylene content was 13% by weight. , An amorphous polyolefin having a melt viscosity of 9,000 cps (190 ° C.) (trade name: REXTAC RT258 manufactured by Lexen)
5), melting point 125 ° C., density 0.918, MI (190
° C) = 3g / 10min linear low density polyethylene (LLD
PE, manufactured by BP Chemical Co., Ltd., trade name 6130AA) was mixed at a weight ratio of RT2585 / LLDPE = 30/70, and the resin composition prepared by melt-kneading at a temperature of 200 ° C. was used. [Molding of Laminated Stretched Film] The resin composition prepared by the above method is used as the layer (A), and the melting point is 125 ° C. and the density is 0.92.
g / cm ³ , MI (190 ° C) = 1.0 g / 10 min L
LDPE (manufactured by Ube Industries, Ltd., trade name FA120N)
Was used for the (B) layer. Outer layer / middle layer / inner layer (B)
3 so that / (A) / (B) becomes the raw material ratio shown in Table 1.
Layer 3 independent extruders and 3 in contact with it
Using a layer die, the melted three layers were co-extruded and then rapidly cooled with an air ring and a water-cooled sizing ring to form a tubular film to obtain a raw film. (300 μ) This original fabric was immediately reheated to 80 ° C., and the difference in speed between the two sets of pinch rolls and air was injected into the original fabric tube to stretch it 4 times in the longitudinal direction and 4 times in the transverse direction to obtain uniform drawing. No film was obtained. This film was heat-fixed with hot air at a temperature of 70 ° C. to obtain a film. The film thickness is 20
It was μ. The properties of the obtained three-layer laminated stretched film were measured, and the results are shown in Table 2. The film composition is shown in Table 1.

Example 2 In contrast to Example 1, linear low density polyethylene (LLDP
Instead of E), melting point 113 ° C, density 0.895 g / cm
³ , MI (190 ° C.) = 3 g / 10 min Ultra Low Density Polyethylene (VLDPE) (Ube Industries, Ltd., trade name Z
522) and amorphous polyolefin (manufactured by Lexen, trade name REXTAC RT2585) at RT2585 /
VLDPE = 30/70 mixed by weight ratio, temperature 200
The resin composition prepared by melt-kneading at 0 ° C. is added to the layer (A),
The layer (B) uses LLDPE to coextrude a film of B / A / B = 1/3/1 as a film layer constitution,
The physical properties of the film, which was biaxially stretched at 0 ° C. and heat-set at 70 ° C., are shown in Table 2. The film composition is shown in Table 1.

Example 3 As compared with Example 1, the layer B had a melting point of 91 ° C. and a density of 0.93 g.
/ Cm ³ , MI (190 ° C) = 0.8g / 10 minutes, VA
15% ethylene-vinyl acetate copolymer (EVA)
(Ube Industries, Ltd., trade name EVA copolymer V11
5) was used. Others were the same as in Example 1 except that the film was formed. The physical properties of the film are shown in Table 2, and the film composition is shown in Table 1.

Example 4 As compared with Example 2, the layer B had a melting point of 91 ° C. and a density of 0.93 g /
cm ³ , MI (190 ° C.) = 0.8 g / 10 min, VA content 15% ethylene-vinyl acetate copolymer (EVA)
(Ube Industries, Ltd., trade name EVA copolymer V11
5) was used. Others were the same as in Example 2 except that the film was formed. The physical properties of the film are shown in Table 2, and the film composition is shown in Table 1.

Comparative Example 1 Both the (A) layer and the (B) layer had a density of 0.91 g / cm ³ , M
FR (230 ° C.) = 9 g / 10 minutes, melting point 138 ° C. Crystalline polypropylene (PP) (manufactured by Ube Industries, Ltd., trade name RF395) was used in the same manner as in Example 1 except that P was used.
A P monolayer film was obtained. The characteristics of the obtained film were measured, and the results are shown in Table 2. From Table 1, it can be seen that this film is a crystalline polypropylene single-layer film and is a hard film having a very high elastic modulus as compared with the PP-based three-layer film of Example 3 in Table 2.

Comparative Example 2 Both the layers (A) and (B) had a melting point of 125 ° C. and a density of 0.92.
Linear low density polyethylene (LLDPE) g / cm ³ , MI (190 ° C) = 1.0 g / 10 min (Ube Industries, Ltd.)
A biaxially stretched film forming experiment was conducted in the same manner as in Comparative Example 2 except that the production temperature was 50 to 120 ° C., but the film was produced at any temperature. Was torn and could not be stretched.

Comparative Example 3 Both the (A) layer and the (B) layer had a melting point of 91 ° C. and a density of 0.93 g.
/ Cm ³ , MI (190 ° C) = 0.8g / 10 minutes, VA
15% ethylene-vinyl acetate copolymer (EVA)
(Ube Industries, Ltd., trade name EVA copolymer V11
Molded in the same manner as in Example 1 except that 5) was used,
In order to obtain a biaxially stretched film, the stretching temperature is 50 to 90 ° C.
However, the film was broken and could not be stretched at any temperature.

Comparative Example 4 The same raw materials as in Example 1 were used, and the thickness composition ratios of the films of the (A) layer and the (B) layer are shown in Table 1. Moreover, the extrusion amount and the take-up speed of the three extruders were adjusted so that the thickness of the unstretched film was 60 μm, to obtain a three-layer unstretched film. The characteristics of the obtained film were measured, and the results are shown in Table 2.

Comparative Example 5 The same raw materials as in Example 3 were used, and the thickness composition ratios of the films of the (A) layer and the (B) layer are shown in Table 1. Moreover, the extrusion amount and the take-up speed of the three extruders were adjusted so that the thickness of the unstretched film was 60 μm, to obtain a three-layer unstretched film. The characteristics of the obtained film were measured, and the results are shown in Table 2.

[0037]

[Table 1]

[0038]

[Table 2]

Front page continuation (51) Int.Cl. ⁶ Identification number Office reference number FI Technology display location B29L 9:00 (72) Inventor Yoshitake Takeshi 3-10 Nakamiyakitamachi, Hirakata-shi, Osaka Ube Industries Co., Ltd. Hirakata Research Co., Ltd. In-house (72) Inventor Takeo Hiratsuka 3-10 Nakamiyakitamachi, Hirakata-shi, Osaka Ube Industries Ltd. Hirakata Research Laboratory

Claims (4)

[Claims] 1. A resin composition containing (A) 20 to 100% by weight of an amorphous polyolefin having a propylene and / or butene-1 component content of 50% by weight or more and 80 to 0% by weight of an ethylene resin. (A) layer made of a material and (B) layer made of crystalline polypropylene and / or ethylene resin (B) are laminated in at least two layers, and one or both outer layers are (B) in a stretched film. ) A polyolefin-based shrink laminated film composed of layers. 2. A melt viscosity (190 ° C.) of an amorphous polyolefin having a propylene and / or butene-1 component content of 50% by weight or more; 1,000 to 100,000 c.
The polyolefin-based shrink laminated film according to claim 1, which has a ps and a density of 0.85 to 0.90 g / cm ³ . 3. Tensile strength 2.5 kg / mm ² or more, a tensile claim is in the range of elastic modulus 5 to 50 kg / mm ² 1, 2
The polyolefin-based shrink laminated film as described in 1. 4. A laminate film comprising a layer (A) and a layer (B) is stretched at a stretching temperature of 40 ° C. to a temperature 10 ° C. lower than the melting point of the resin constituting the layer (B) at a stretching ratio of 2 to 60 times, The method for producing a polyolefin-based shrink laminated film according to claim 1, wherein the heat-setting is performed as necessary.