KR19980028458A - Industrial multilayer stretch packaging film - Google Patents

Abstract

The present invention relates to an industrial multilayer stretch packaging film excellent in stretchability, elasticity, film strength, adhesiveness, chargeability and unwinding property. The film comprises (a) 60 to 95 weight percent of a copolymer of ethylene with an α-olefin having 4 to 20 carbon atoms, with a density of 0.890 to 0.925 g / cm ³ , and (b) a density of 0.860 to 0.910 g / cm. ³ , a composition having 40 to 5% by weight of a low crystalline copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms, or an ethylene having 4 to 20 carbon atoms having a density of 0.915 to 0.960 g / cm ³ into a first layer (A) of the copolymer with an α-olefin and a second layer (B) of a copolymer of ethylene with an α-olefin having 4 to 20 carbon atoms with a density of 0.915 to 0.960 g / cm ³ . consist of.

Description

Industrial multilayer stretch packaging film

The present invention relates to an industrial multilayer stretch packaging film. More specifically, the present invention is intended to prevent moisture and dust, and to quickly package and implement as a pellet stretched film of various resins, electrical appliances, electronic products, brick packaging, and industrial packaging, and to exhibit stretchability, elasticity, film strength, The present invention relates to an industrial multilayer stretch packaging film composition excellent in tackiness, chargeability, and unwindability, and a method for producing the same.

Industrial packaging films are used for industrial purposes such as pellets, electrical appliances, electronics, brick packaging, etc., and packaging industry for logistics transportation, along with logistics automation, prevents the packaging contents from being disturbed due to perfect packaging during product packaging. Recently, rapid development has been made, and this packaging industry takes advantage of the molecular properties of conventional polyethylene to shrink packaging or PP based on LDPE resins. Starting from banding and iron bending, it has been continuously developed into LDPE, LLDPE and VLDPE products that can pack more packages with less resin amount while having excellent mechanical properties of resin.

Conventional stretch packaging films are extruded into a single layer blown film by mixing LDPE, LLDPE and additives as raw materials.However, when LLDPE and LDPE are used, the strength and stretching of the film are poor and the transparency is poor. There was a problem that the contents could not be accurately grasped, and since the single-layer extrusion, the pressure-sensitive adhesive was transferred to the inside and outside of the film to degrade the adhesiveness. It generates noise and static electricity severely, reducing workability.

The term stretched film herein refers to a film used for packaging purposes such as to prevent contamination from the outside and to prevent damage from dropping when storing and transporting certain contents by stretching to a thin film of 10 to 100 μm. It must have the same properties:

(1) extensibility

Good stretching properties are required for the film to be well pulled in order to ensure stable packaging and no disturbance during transportation.

(2) elasticity

A good stretched film, on the other hand, must have some degree of elasticity to safely wrap the package inside the film.

(3) strength

Safe packing of protruding parts, shock during transportation of package and friction with foreign materials should have excellent perforation strength, tear strength and impact strength to prevent the contents from falling.

(4) transparency and glossiness

When the film wrapped with the packaging film is transparent and has good gloss, the contents can be visually checked, and the advertising effect of the contents and the value of the product can be maximized.

(5) adhesiveness and loosening property

When packing the contents in a thin packing film, it should have a certain adhesiveness and protect the contents safely in the stretched state. If too sticky, the film sticks to each other when unpacking the film in the automatic packing machine before packing, which increases noise and decreases workability.

(6) Daejeon

In the case of industrial stretched films, thin films are mostly used, and since static electricity is generated by using high temperature processing and pressure-sensitive adhesives, the chargeability should be excellent.

Accordingly, an object of the present invention is to better package the contents more securely and transparently with excellent film strength and transparency, and to use the appropriate amount of pressure-sensitive adhesive as well as to provide proper adhesiveness at the same time by using co-extrusion rather than single-layer extrusion. This is to produce a stretched film having excellent unwinding property and excellent chargeability.

Surfactants, oils, atactic polypropylene (polybutene), polybutene, and the like may be added for the tackiness of the film, but polybutenes having a molecular weight of 660 to 2060 are most suitable for stretch packaging films. Tackiness was relatively good.

In the case of the existing product, the adhesiveness is also reduced by the transfer of both sides of the adhesive due to the single-layer film and the adhesive is transferred to the unnecessary part, so that the loosening property is poor and the static electricity is generated, which lowers the workability. (The adhesive applied to the stretched film does not have compatibility with PE, so it transfers to the surface during film extrusion. It uses the principle of shifting from high to low crystallinity.) By transferring to the inner layer), the adhesiveness can be imparted only to the desired layer (inner layer). Furthermore, in the present invention, when only the adhesive is added, 1% of glycol monostearate of surfactant system is added to the adhesive in order to improve the problem of poor looseness of the thin packaging film and the problem of poor workability due to static electricity. This solves the problem of loosening (noise generation) and static electricity generation with moderate adhesiveness.

In addition, the additives added to the polyethylene is better to transfer the higher the ambient temperature, so if the packaging film is produced in winter, the ambient temperature is lower, so the adhesive tends to be poor due to poor transferability of the adhesive. In order to improve the adhesiveness by aging the film at an appropriate temperature and time (50 ℃, 24 hours) to assist the transition of the pressure-sensitive adhesive.

The polyethylene-based multilayer film having excellent properties according to the present invention has a specific composition layer containing two specific ethylene-α-olefin copolymers in a predetermined ratio, or a specific density while having ethylene units and α-olefin units. It is a multilayer film which consists of a specific copolymer layer which has a, a specific ethylene-alpha-olefin copolymer layer, and the specific ethylene polymer layer was formed between these layers.

That is, the present invention is (a) 60 to 95% by weight of a copolymer of ethylene and an α-olefin having 4 to 20 carbon atoms with a density of 0.890 to 0.925 g / cm ³ , and (b) a density of 0.860 to 0.890 g / cm ³ a, the ethylene and carbon atoms is 3 to 12, the low-crystalline composition having a copolymer of 40 to 5% by weight, or a density of 0.915 to 0.960 g / cm ³ of ethylene and α- olefin with a carbon number of from 4 to The first layer (A) of the copolymer with an α-olefin having 20 and a second layer composed of a copolymer of ethylene having an density of 0.915 to 0.960 g / cm ³ and an α-olefin having 4 to 20 carbon atoms ( It is provided with a polyethylene-based multilayer film characterized by having B).

In the multilayer film of the present invention, the first layer (A) is composed of a specific composition layer or a specific copolymer layer having a specific density.

As the specific composition, (a) one species of ethylene and 4 to 20, preferably 4 to 12, density in the range of 0.890 to 0.925 g / cm ³ , preferably 0.895 to 0.920 g / cm ³ . Or a copolymer of two or more α-olefins, and (b) ethylene and 3 to 12 carbon atoms, preferably having a density in the range of 0.860 to 0.900 g / cm ³ , preferably 0.870 to 0.890 g / cm ³ . Is a mixture consisting of 4 to 10 low-crystalline copolymers with one or two or more α-olefins.

When the copolymer of the component (a) is less than 0.890 g / cm ^3, the stiffness of the film is low and the elongation and impact resistance tend to be lowered when it exceeds 0.925 g / cm ³ .

The melt index of the copolymer of component (a) is preferably in the range of 1 to 50 g / 10 minutes, preferably 2 to 30 g / 10 minutes. When the melt index is less than 1 g / 10 min, the melt viscosity of the copolymer is high, and thus the moldability of the first layer (A) is lowered. When it exceeds 50 g / 10 min, the melt viscosity is too low and the first layer is In addition to reducing the moldability of (A), the mechanical strength of the film tends to decrease, which is not preferable.

As an alpha olefin used as a raw material monomer of the ethylene- alpha-olefin copolymer of the said (a) component, for example, butene-1, pentene-1, hexene-1, nonene-1, decene-1, dodecene-1 , Α-olefins such as tetradecene-1, octadecene-1, 4-methylpentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene-1, or mixtures thereof. C4-C12 alpha-olefins are preferable, and octene-1 is especially preferable.

On the other hand, when the density of the low crystalline copolymer of the component (b) is less than 0.860 g / cm ^3, the rigidity of the film is easy to cause blocking, and when the content exceeds 0.900 g / cm ³ , the transparency improvement effect of the film is sufficiently May not be exercised.

The low crystalline copolymer of component (b) preferably has a crystallinity of 40% or less in terms of improving the moldability and transparency of the film, and a melt index of 0.5 to 50 g / 10 minutes, preferably 1 To 20 g / cm ³ . When the melt index is less than 0.5 g / 10 minutes, the transparency improvement effect is not sufficiently exhibited, and when it exceeds 50 g / 10 minutes, the blocking property of the film is deteriorated and mechanical strength tends to decrease, which is not preferable.

In the copolymer of component (b), examples of the α-olefins used as raw material monomers include propylene, butene-1, pentene-1, hexene-1, octene-1, nonene-1, decene-1, Α-olefins such as dodecene-1, 4-methylpentene-1, 4-methylhexene-1, 4,4-dimethylpentene-1, or mixtures thereof, but among these, α- having 4 to 10 carbon atoms Olefin is preferred, in particular octene-1.

In the present invention, the components (a) and (b) are blended at a ratio of 60 to 95 wt% and 40 to 5 wt%, preferably 64 to 92 wt% and 36 to 8 wt%, respectively. need. When the compounding quantity of the said (b) component is less than 5 weight%, the transparency improvement effect is not fully exhibited, and when it exceeds 40 weight%, the film obtained will be easy to block and there exists a tendency for moldability to fall.

The specific copolymer used as the first layer (A) has ethylene and 4 to 20 carbon atoms, preferably having a density in the range of 0.890 to 0.910 g / cm ³ , preferably 0.895 to 0.910 g / cm ³ . It is a copolymer with the alpha-olefin of 4-12. If the density is less than 0.890 g / cm ^{3, the} film has low rigidity and is easy to cause blocking, and if it exceeds 0.910 g / cm ³ , the impact resistance is lowered and the elongation rate tends to be lowered.

The melt index of the copolymer is preferably in the range of 1 to 50 g / 10 minutes, preferably 2 to 30 g / 10 minutes. If the melt index is less than 1 g / 10 min, the moldability is high due to the high melt viscosity, and if it exceeds 5 g / 10 minutes, the melt viscosity is too low to deteriorate the moldability and the mechanical strength of the film tends to be lowered. Not.

As an alpha olefin used as a raw material monomer of the said copolymer, it was as having demonstrated in description of the ethylene- alpha-olefin copolymer of the said (a) component, Among these, the C4-12 alpha-olefin is preferable, and octene is especially preferable. -1 is preferred.

In the multilayer film of the present invention, ethylene and 3 to 20 carbon atoms, preferably ³ , have a density in the range of 0.860 to 0.900 g / cm ³ , preferably 0.88 to 0.910 g / cm ³ , as the second layer (B). Copolymers with olefins of from 12 to 12 are used. When the density is less than 0.860 g / cm ^3, the rigidity of the film is lowered and blocking is likely to occur. When the density is more than 0.910 g / cm ³ , the impact resistance and transparency of the film tend to be lowered.

The melt index of the copolymer is in the range of 0.5 to 30 g / 10 minutes, preferably 1 to 20 g / 10 minutes. If the melt index is less than 0.5 g / 10 minutes, the melt viscosity is high, the moldability is low, and if it exceeds 30 g / 10 minutes, the melt viscosity is too low, difficult to mold and mechanical strength also tends to be lowered, which is not preferable.

As an alpha olefin used as a raw material monomer of the said copolymer, For example, propylene, butene-1, pentene-1, hexene-1, octene-1, nonene-1, decene-1, dodecene-1, tetradecene Α-olefins such as -1, octadecene-1, 4-methylpentene-1, 4-methylhexene-1, 4,4-dimethylpentene-1, or mixtures thereof, but include 3 to 12 carbon atoms. Α-olefins are preferable, and propylene, butene-1 and octene-1 are particularly preferable.

As for the multilayer film of this invention, the two-layer film which consists of said 1st layer (A) and a 2nd layer (B) is preferable, The intermediate | middle layer (between 1st layer (A) and 2nd layer (B) C) as high pressure polyethylene and / or ethylene having a density in the range of 0.880 to 0.910 g / cm ³ , preferably 0.890 to 0.900 g / cm ³ , and an α-olefin having 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms. It is also preferred to have a layer consisting of a copolymer with.

When the density of the ethylene-based polymer used in the intermediate layer (C) is less than 0.890 g / cm ³ The rigidity of the intermediate layer (C) is less, there is a fear that the middle of the film is soft, when the film exceeds 0.910 g / cm ³ The transparency tends to be lowered.

The melt index of the interlayer (C) copolymer is preferably in the range of 0.5 to 5 g / 10 minutes, preferably 1 to 20 g / 10 minutes. If the melt index is less than 0.5 g / 10 minutes, the melt viscosity is not high because the moldability is not preferable, if it exceeds 50 g / 10 minutes melt viscosity is too low, the moldability is lowered, the mechanical strength of the film is lowered This is undesirable.

It is preferable that the said intermediate | middle layer (C) uses the high pressure polyethylene which has the said physical property, a copolymer of ethylene and an alpha olefin, and a mixture thereof. As an alpha olefin used as a raw material monomer of the said copolymer, For example, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, dodecene- Α-olefins such as 1, tetradecene-1, octadecene-1, 4-methylpentene-1, 4-methylhexene-1, 4,4, -dimethylpentene-1, or mixtures thereof, Among these, α-olefins having 4 to 10 carbon atoms are preferable, but butene-1 and octene-1 are particularly preferable.

The copolymer of ethylene and alpha-olefin used for the 1st layer (A) in the multilayer film of this invention is the density | concentration for which ethylene and alpha-olefin are aimed by the low pressure method among the so-called using a transition metal catalyst. It can manufacture by superposing | polymerizing in the ratio so that it may become. At this time, the type and amount of the chain transfer agent is appropriately selected to have a desired melt index. As the polymerization method, various methods such as slurry polymerization method, gas phase polymerization method and solution polymerization method can be used.

Moreover, the copolymer of ethylene and alpha-olefin used for a 2nd layer (B) and an intermediate | middle layer (C) has low density and very narrow molecular weight distribution, and ethylene, butene-1, hexene-1, and octene-1; It is a novel copolymer of. Low density can be obtained by using high content of butene-1, hexene-1 and octene-1.

The very narrow molecular weight distribution is due to the metallocene type (titanocene zirconocene) transition of the Periodic Table Group B (CRC Handbook of Chemistry and Physics, 68th ed. 1987-1988) of the type described in US Pat. No. 5,055,438. A metal compound catalyst can be obtained using an alumoxane cocatalyst, which produces a polymer having a high weight average molecular weight of 100,000 to 110,000 with an extremely narrow MWD of 2 to 4, wherein the polyolefin or Ethylene-α-olefins exhibit high strength properties. Products using these catalysts have surprisingly low content of n-hexane extracts, even at low densities, to meet the limits.

Ultra low density polyethylene (also called VLDPE) in the present invention has a density range of 0.860 to 0.910 g / cm ³ and linear ethylene-produced by a metallocene type transition metal compound catalyst of Group IV B of the periodic table and an alumoxane cocatalyst system. refers to an α-olefin polymer. Ultra low density polyethylene is also included in this term.

As used herein, the term flow rate ratio (FRR) refers to dimensionless water derived by dividing the flow rate by the flow rate of the reference conditions (melt flow or melt index) under other conditions (ASTM D1238). The melt flow rate ratio (I ₁₀ / I ₂ ) is at least 5.63, and the MWD (M _w / M _n ) is (I ₁₀ / I ₂ ) -4.63.

FRR represents the molecular weight distribution. The larger the FRR, the wider the molecular weight distribution. As used herein, the term ethylene copolymer refers to a copolymer of ethylene and comonomers in a strict sense.

The term ethylene-α-olefin copolymer as used herein also means a copolymer of ethylene and higher α-olefins such as butene, 1-kenylpentene, hexene, octene. Preferred compositions are about 10 to 90% of butene-1, hexene-1 or octene-1 and about 90 to 10% of very low density polyethylene. More preferred compositions are copolymers of butene-1, hexene-1 about 15-20% and very low density polyethylene about 85-80%.

Particularly preferred resins are high molecular weight VLDPE resins such as EXACT 3037 manufactured by Exxon Corporation. This resin has a density of 0.900 g / cm ³ and a melt flow rate of 2.22 g / 10 minutes (190 DEG C in ASTM D1238 state). Preferred VLDPE resins are characterized by high molecular weight (ie, relatively low melt index), particularly narrow molecular weight distribution (ie, low flow rate ratio), and relatively low crystallinity.

The melt index (MI) for the VLDPE is preferably about 0.5 to 5.0 g / 10 min (ASTM D1238) (condition 190 ° C./2.16). More preferred MI is 1.0 to 1.0 g / 10 min. Even more preferred MI is 2.2 g / 10 min. A molecular weight distribution (flow rate ratio) of at least about 5 (10.0 / 2.15 kg) (ASTM D1238) is preferred for VLDPE. This value is obtained by dividing the flow rate under condition 190 / 10.0 by the flow rate under condition 190 / 2.16. More preferred FRR is 5.63. The preferred density (degree of crystallinity) for VLDPE is about 0.860 to 0.910 g / cm ³ (ASTM D1505), the more preferred density (degree of crystallization) is about 0.860 to 0.910 g / cm ³ (ASTM D1505), and the more preferred density is 0.870 to 0.900, even more preferably 0.890 to 0.900 g / cm ³ .

About the thickness ratio of each layer in the multilayer film of this invention, in the case of a 2-layer film, the thickness ratio with 1st layer (A): 2nd layer (B) is usually 2: 98-50: 50, Preferably 3:97 to 40:60, and in the case of a three-layer film, the thickness ratio of the first layer (A): intermediate layer (C): second layer (B) is equal to the first layer (A) When the thickness of the second layer (B) is the same, it is usually selected in the range of 2: 96: 2 to 40:20:40, preferably 3: 94: 3 to 30:40:30. In addition, the overall thickness of the multilayer film is usually selected in the range of 10 to 100 µm, preferably 20 to 50 µm, more preferably 20 to 30 µm.

There is no restriction | limiting in particular about the manufacturing method of the multilayer film of this invention, The method conventionally used for manufacture of a multilayer film conventionally, for example, the inflation film shaping | molding method, the T-die film shaping | molding method, etc. can be used. At this time, the resin temperature is usually selected in the range of 200 to 300 ° C., the chilling method is usually used for the T die molding method, and the air cooling method is used for the inflation molding method for cooling the molded film. In the case of the chilling method, it is necessary to bring the second layer (B) into contact with the lower surface.

The cooling temperature is usually selected in the range of 20 to 80 ° C, preferably 30 to 70 ° C. When cooling temperature is lower than 20 degreeC, rigidity of a film may fall, handling property may worsen, and when higher than 80 degreeC, film formability and appearance of a film may deteriorate and it is unpreferable.

In the multilayer film of the present invention, any of the layers or all the layers of the present invention, as necessary, such as antioxidants, light stabilizers, heat stabilizers, antiblocking agents, lubricants, catalyst neutralizers (chlorine absorbers), antifogging agents, antistatic agents, etc. Various additives used for the polyethylene film can be added. As antioxidant, a phenol type or phosphorus type is mentioned preferably, Especially these combination is preferable. As a phenolic antioxidant, a 2, 6- di-t- butyl- 4-methyl phenol, a tris (3, 5- di- t- butyl- 4-hydroxy benzyl) isocyanurate (Shibagai Corporation, for example) Product Irganox 3114), 2,2'-methylenebis (4-methyl-6-t-butylphenol), n-octadecyl-3- (3 ', 5'-di-t-butyl-4'-hydroxy Phenyl) propionate (Irganox 1076 from Ciba-Geigy Co., Ltd.), 4,4-thiobis (3-methyl-6-t-butylphenol), Irganox 1010), 4,4'-butylidenebis (3- Methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), N, N'-hexamethylenebis (3,5-di-t-butyl-4 -Hydroxyhydrocinnamid) (Irganox 1098 from Ciba-Geigy Co., Ltd.) Triethylene glycol-bis [3- (3'-t-butyl-5'-methyl-4- hydroxyphenyl) propionate], Bis (3 And mixture of (5-part-di-t-butyl-4-hydroxyphosphonate ethyl) calcium and PE wax (parts by weight 1: 1) (Irganox 1425ML, available from Ciba-Geigy Co., Ltd.).

As a phosphorus antioxidant, for example, distearyl pentaerythritol diphosphate (Mar. KPEP-8 made by Adega Agas Co.), tetrakis (2,4-di-t-butylphenyl), 4,4'-ratio Phenylenediphosphate (Sandostabp-EPQ from Sand Company), trisnonylphenyl phosphate, tris (2,4-di-t-butylphenyl) phosphate (Mar.KPEP-8 from Adega Agas company), tetrakis (2 , 4-di-t-butylphenyl), 4,4'-biphenylenediphosphate (Sandostabp-EPQ from Sands), trisnonylphenyl phosphate, tris (2,4-di-t-butylphenyl) phosphate ( MARK 2112) di (2,4-di-t-butylphenyl) pentaerythritol diphosphate (MARKPEP-36 by Adega-Agas company) etc. by Adega-Agas company etc. are mentioned.

As a light stabilizer, a salicylate type, a benzophenone type, a triazole type, an oxalate anhydride type, a hindered amine type, etc. are used, for example. Examples of the antiblocking agent include natural silica, synthetic silica, zeolite, amorphous zeolite, diatomaceous earth, and the like, and among them, diatomaceous earth is particularly preferable.

Examples of anti-loosening agents include sorbitan fatty acid esters and glycerol fatty acid esters.

Embodiments of the present invention are described in detail as follows.

Example 1

VLDPE 9% of SLP 9074 (1.2 MI, 0.900 density, terpolymer) from Exxon as the inner layer (3 μm), LLDPE of the lucky LLDPE FB 1010 (butene comonomer of 1.0 MI, 0.919 density) as the intermediate layer (14 μm) A composition consisting of 77% (4% polyisobutene pressure-sensitive adhesive from high-acid products + 1% noise suppressant from Atmer 100 from ICI), and 9% LLDPE as the outer layer (3 μm) was extruded for inflation film, in winter Three-layer films were prepared by aging for 24 hours at 50 ° C. for effective transition of the pressure-sensitive adhesive. This film was suitable for stretch packaging films, and in particular, the film was excellent in strength, transparency, tack, annealability, and antistatic property.

Example 2

LLDPE of EXC 3037 (2.2 MI, 0.900 density, hexene copolymer) manufactured by Exxon as an inner layer (3 μm), VLPE 9% of Lucky Technological Line FB2500 (butene copolymer of 2.5 MI, 0.917 density) as an intermediate layer (14 μm) A composition consisting of 77% (4% polyisobutene pressure-sensitive adhesive from high-product products + 1% noise suppressant from Atmer 100 from ICI), and 9% LLDPE as the outer layer (3 μm) was extruded using an extruder for T-die and 50 Aged at 24 ° C. for 24 hours to produce a three layer film. This film was suitable for stretch packaging film, and because the inflation density was high, the adhesive was used a little, but the transparency was better, and the strength, adhesiveness and unsealability were also excellent.

As described above, according to the present invention, an industrial multilayer stretch packaging film excellent in stretchability, elasticity, film strength, adhesion, chargeability, and unwinding property can be produced.

Claims (20)

(A) 60 to 95% by weight of a copolymer of ethylene and an α-olefin having 4 to 20 carbon atoms (a) having a density of 0.891 to 0.925 g / cm ³ , and (b) a density of 0.860 to 0.910 g / cm ³ A first layer having 40 to 5% by weight of a low crystalline copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms; And (B) Polyethylene-based multilayer film comprising a second layer having 3 to 10% by weight of polybutene and 0.5 to 5% by weight of surfactant as an adhesive. The method of claim 1, The film of (b), wherein the ethylene copolymer is ultra low density polyethylene (VLDPE). The method of claim 2, The film whose alpha-olefin which is a copolymerization monomer of VLDPE is butene-1, hexene-1, or octene-1. The method of claim 3, wherein Wherein said α-olefin, which is a copolymerization monomer of VLDPE, is octene-1, which is branched to the main chain of the VLDPE copolymer. The method of claim 2, The film having a density of 0.860 to 0.910 g / cm ³ . The method of claim 2, The film having a molecular weight distribution (MFRR = 10.0 / 2.16 kg) of the VLDPE is 4 to 8. The method of claim 2, MWD measurement through GPC of the VLDPE is 2 to 3 film. The method of claim 2, Wherein said VLDPE is polymerized in the presence of a metallocene transition metal component catalyst of Group IV B of the periodic table and an alumoxane cocatalyst. The method of claim 7, wherein The VLDPE has a MWD of 2 to 4 and a weight average molecular weight of 100,000 to 110,000. The method of claim 4, wherein A film having a melt flow rate (I ₁₀ / I ₂ ) of 5.63 or more and a MWD (M _w / M _n ) of (I ₁₀ / I ₂ ) -4.63. The method according to claim 1 or 2, The film of the first layer (A) is made of (a) copolymer having a melt index of 0.5 to 50 g / 10 minutes and a low crystalline copolymer having a melt index of 0.5 to 15 g / 10 minutes. The method of claim 1, The first layer (A) comprises (a) a copolymer having ethylene units and butene-1 or hexene-1 units and (b) a low crystalline copolymer having ethylene units and butene-1 or hexene-1 units Made up of film. The method according to claim 1 or 2, A film having an ethylene unit and butene-1 or hexene-1 unit and further having an intermediate layer (C) made of an ethylene-α-olefin copolymer having a melt index of 0.5 to 30 g / 10 minutes. The method of claim 13, As a three-layer film, the thickness of the 1st layer (A) and the 2nd layer (B) is the same, and the thickness ratio of 1st layer (A): intermediate layer: 2nd layer (B) is 2: 96: 2-40:20 : 40 phosphorus film. The method of claim 1, 1st layer (A): The film whose thickness ratio of 2nd layer (B) is 2: 98-50: 50. The method of claim 1, Wherein the polybutene of the second layer has a viscosity of 200 to 500 and a molecular weight of 660 to 3060. The method of claim 1, A film in which an anti-wrinkle agent is added to any or all layers of each layer. The method of claim 17, Wherein said anti-loosening agent is a sorbitan fatty acid ester and a glycerol fatty acid ester. The method of claim 1, Wherein said surfactant is glycol monostearate. The method of claim 1, The multilayer film has a thickness of 20 to 30 ㎛.