JP2002264283A - Antistatic multi-layer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-layer film excellent in antistatic properties and a product excellent in antistatic properties which is obtained by laminating the multi-layer film. SOLUTION: The multi-layer film is composed of at least two layers of a layer containing an antistatic agent in an amount within a specified range and a layer containing polyethylene or an ethylene-α-olefin copolymer. The antistatic agent is prepared from a surfactant component the molecular weight of which is within a specified range. The mixing ratio of the agent to the copolymer whose density is within a specified range and whose melt flow rate is within a given range is within a specified range. The mixing ratio of the agent to the surfactant component is within a specified range. The density of the polyethylene is within a specified range and higher by a specified range than that of the copolymer, and the melt flow rate of the polyethylene is within a given range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a multilayer film. More specifically, the present invention relates to a multilayer film having excellent antistatic properties and a product having excellent antistatic properties obtained by laminating the multilayer film.

[0002]

2. Description of the Related Art Polyethylene films are widely used as packaging materials for foods, pharmaceuticals, sundries, industrial goods, etc. because of their excellent low-temperature heat sealability and heat seal strength. However, polyethylene-based films generally have large electrical insulation resistance, and easily generate and accumulate, that is, charge, static electricity due to friction. Dust adheres to the film product due to the static electricity, and the appearance of the product deteriorates, or when the packaged product is a powder product, the powder product adheres violently and the work efficiency may be reduced.

[0003] As a method of preventing charging, conventionally,
Methods using an antistatic agent are known, and examples thereof include a method of applying the antistatic agent to the surface of the film and a method of mechanically kneading the film. The former coating method has an immediate effect, but the antistatic agent drops off due to friction, cleaning, etc., and it is difficult to maintain the antistatic effect over a long period of time. ,
The latter kneading method (referred to as a kneading type) is used.

In some cases, a laminate obtained by laminating a polyethylene film on a base film by a dry lamination method is used as a packaging material. The laminate obtained by the dry lamination method is generally provided with an adhesive layer containing an adhesive between the laminated polyethylene film and the base film, and the antistatic agent migrates to the adhesive layer. In some cases, and sufficient antistatic properties may not be exhibited.

For example, Japanese Patent Application Laid-Open No. 05-169601 discloses that a specific antistatic agent and a higher alcohol are blended in a specific amount in a polyolefin resin and have a sufficient antistatic effect even after extrusion lamination at a high temperature. In addition, a laminated film that has a long-lasting antistatic effect and has a sufficient adhesive strength with a substrate is described. However, as described above, in the case of a laminated laminate obtained by a dry lamination method, an antistatic agent adheres. In some cases, the antistatic properties may not be obtained due to migration to the agent layer, and improvement of the antistatic properties has been desired.

[0006]

An object of the present invention is to provide a multilayer film having excellent antistatic properties and a product having excellent antistatic properties obtained by laminating the multilayer film.

[0007]

Means for Solving the Problems In view of such circumstances, the present inventors have conducted intensive studies and as a result, have found that the density is in a specific range and the melt flow rate is in a constant range. With respect to the ethylene-α-olefin copolymer composed of α-olefins in the range, the blending ratio is in a specific range, the surfactant component in which the molecular weight is in a specific range, and the blending ratio is in a specific range, and the molecular weight is Is composed of a surfactant component having a specific range, a layer containing an antistatic agent having a fixed amount in a certain range, and a density in a specific range, the density of the ethylene-α-olefin copolymer described above. An ethylene homopolymer having a melt flow rate in a certain range higher than a specific range and an ethylene-α-olefin comprising ethylene and an α-olefin having a certain number of carbon atoms. The present inventors have found that a multilayer film composed of at least two layers containing a copolymer can solve the above problems, and have completed the present invention.

That is, according to the present invention, the density is 860-92.
5 kg / m ³ , melt flow rate is 0.5-30 g /
10 minutes of ethylene and α of 3 to 12 carbon atoms
Surfactant component (A) having a molecular weight of 400 or more and 50 to 95% by weight and a surfactant having a molecular weight of less than 400 based on 100 parts by weight of an ethylene-α-olefin copolymer (A) composed of an olefin Component (B) 50 to 5% by weight
(A) layer containing 0.05 to 2 parts by weight of an antistatic agent consisting of: a density of 926 to 970 Kg / m ³ , and a density of 5 kg from the density of the ethylene-α-olefin copolymer (A)
/ M ³ or more, melt flow rate is 0.5 to 30 g
(B) containing an ethylene homopolymer or an ethylene-α-olefin copolymer (B) composed of ethylene and an α-olefin having 3 to 12 carbon atoms.
The present invention relates to a multilayer film composed of at least two layers. Hereinafter, the present invention will be described in detail.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The multilayer film (a) of the present invention has ethylene and carbon atoms of 3 to 3 used in the layer (a).
Examples of the α-olefin having 3 to 12 carbon atoms of the ethylene-α-olefin copolymer (A) composed of 12 α-olefins include, for example, propylene, butene-1, pentene-1, 4-methylpentene- 1, hexene-1, heptene-1, octene-1, nonene-1, decene-1,
Dodecene-1 and the like, and mixtures thereof, and the like. Preferably, propylene, butene-1,4-methylpentene-
1, hexene-1, 4-methylhexene-1, octene-
1, more preferably hexene-1, octene-1
It is. The content of α-olefin contained in the ethylene-α-olefin copolymer is preferably 1
~ 20 mol%.

[0010] Ethylene-α-olefin copolymer (A)
Are, for example, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-hexene-1
Copolymers, ethylene-octene-1 copolymers and the like are exemplified, and ethylene-hexene-1 copolymer and ethylene-octene-1 copolymer are preferable.

[0011] Ethylene-α-olefin copolymer (A)
Has a density of 860 to 925 Kg / m ³ , preferably 880 to 925 Kg / m ³ , and more preferably 9 to 925 Kg / m ^3.
It is a 00~925Kg / m ^3.

When the density of the copolymer (A) is 860 kg / m ³
If the amount is less than 925 kg / cm ³ , the anti-blocking property and the food hygiene property may be insufficient, and if it exceeds 925 Kg / cm ³ , the low-temperature heat sealing property and the low-temperature hot tack property may be insufficient.

[0013] Ethylene-α-olefin copolymer (A)
Has a melt flow rate of 0.5 to 30 g / 10 min, preferably 0.5 to 20 g / 10 min, and more preferably 0.5 to 10 g / 10 min.

When the melt flow rate of the copolymer (A) is less than 0.5 g / 10 minutes, the extrusion load in the film forming becomes high and the extrusion processability may be insufficient. If it exceeds, the film strength may be insufficient.

[0015] Ethylene-α-olefin copolymer (A)
It is particularly preferable that the following conditions (a-1) and (a)
It is an ethylene-α-olefin copolymer satisfying -2). (A-1) The composition distribution variation coefficient (Cx) obtained from the following (Equation 1) is 0.5 or less. Cx = σ / SCBave. Where σ is the standard deviation of the composition distribution and SCBave.
Average value of short chain branch per 000C (1 / 1000C)
Represents (A-2) The density (d) and the weight ratio (a) of the cold xylene-soluble portion have the following relationship (formula 2). a <(4.8 × 10 ⁻⁵ ) × (950−d) ³ + (10 ⁻⁶ ) × (950−d) ⁴ +1 (Formula 2) (where, a is the weight ratio of the cold xylene soluble part) (weight%),
d is the density of the ethylene-α-olefin copolymer (Kg /
m ³ ). )

The above-mentioned composition distribution variation coefficient (Cx) indicates a measure of the composition distribution, and a smaller value indicates a narrower composition distribution. The composition distribution variation coefficient (Cx) of the ethylene-α-olefin copolymer (A) is preferably 0.5 or less from the viewpoint of the balance between transparency and antiblocking property.

Ethylene-α-olefin copolymer (A)
The relationship between the density (d) and the weight ratio (a) of the cold xylene-soluble portion is preferably the following (Equation 2) from the viewpoint of the balance between transparency and mechanical strength: a <(4.8) × 10 ⁻⁵ ) × (950−d) ³ + (10 ⁻⁶ ) × (950−d) ⁴ +1 (Equation 2) More preferably, the following (Equation 3), and a <(4.8 × 10 ⁻⁵ ) × (950-d) ³ + (10 ⁻⁶ ) × (950-d) ⁴ (formula 3) More preferably, the following (formula 4). a <(4.8 × 10 ⁻⁵ ) × (950−d) ³ (Equation 4)

Ethylene-α-olefin copolymer (A)
The production method of is not particularly limited, and includes a production method using a known polymerization catalyst and a known polymerization method. Known catalysts include Ziegler-Natta catalysts and metallocene catalysts. Examples of the Ziegler-Natta catalyst include a catalyst comprising a solid catalyst component containing a transition metal compound and an organoaluminum compound. Examples of the solid catalyst component containing a transition metal compound include chromium oxide, molybdenum oxide, and trichloride. Examples include solid catalyst components containing titanium, titanium tetrachloride and the like, and examples of the organic aluminum compound include triethylaluminum and triisobutylaluminum.

From the viewpoint of producing the preferred ethylene-α-olefin copolymer (A), as a polymerization catalyst,
Particularly preferred are metallocene-based catalysts, for example, those comprising a catalyst component containing a transition metal compound having a group having a cyclopentadiene-type anion skeleton and an organic aluminum compound and / or an ionic compound. As the transition metal compound having a group having the general formula: ML _a X _na (wherein
M is a transition metal atom of Group 4 of the periodic table of the element or a lanthanide series. L is a group having a cyclopentadiene-type anion skeleton or a group containing a hetero atom, and at least one is a group having a cyclopentadiene-type anion skeleton. A plurality of Ls may be cross-linked to each other.
X is a halogen atom, hydrogen or a hydrocarbon group having 1 to 20 carbon atoms. n represents the valence of the transition metal atom, and a represents 0 <
It is an integer such that a ≦ n. )). Further, the above transition metal compounds may be used alone or in combination of two or more.

The organic aluminum compound includes, for example, an aluminoxane compound, and the ionic compound includes, for example, trityl borate and anilinium borate.

Further, examples of the metallocene catalyst include those in which the above-mentioned transition metal compound, organoaluminum compound and / or ionic compound are supported on a particulate carrier. Examples of the particulate carrier include an inorganic carrier such as SiO ₂ and Al ₂ O _{3 and} an organic polymer carrier such as an olefin polymer such as ethylene and styrene.

Known polymerization methods include a solution polymerization method, a slurry polymerization method, a high-pressure ionic polymerization method, a gas-phase polymerization method and the like, and preferably a gas-phase polymerization method and a high-pressure ionic polymerization method. The polymerization temperature is usually 30 to 300 ° C., and the polymerization pressure is usually normal pressure to 300 MPa.

The antistatic agent used in the layer (a) of the multilayer film of the present invention includes a surfactant component (A) having a molecular weight of 400 or more and a surfactant component (B) having a molecular weight of less than 400. It consists of Molecular weight 40
By using the surfactant component (A) having a molecular weight of less than 400 and the surfactant component (A) having a molecular weight of less than 400, a multilayer film having sufficiently excellent antistatic properties can be obtained.
The transfer of the antistatic agent to the adhesive layer in the laminate obtained by the dry lamination method is remarkably suppressed, and a laminate having sufficiently excellent antistatic properties can be obtained.

Examples of the surfactant component (A) having a molecular weight of 400 or more include fatty acid esters and the like, such as monoglycerin fatty esters and polyglycerin fatty esters. Preferably, they are polyglycerin fatty esters. Monoglycerin fatty esters include, for example, glycerin monostearate (GMS), and polyglycerin fatty esters include, for example, diglycerin monostearate (DGMS).

The surfactant component (B) having a molecular weight of 400 or more includes, for example, alkyl diethanolamides, aliphatic alcohols, etc., preferably alkyl diethanolamides. Examples of the alkyl diethanolamides include stearyl diethanolamide, laurin diethanolamide, and oleyl diethanolamide, and examples of the aliphatic alcohol include stearyl alcohol.

The weight ratio of the surfactant component (A) having a molecular weight of 400 or more in the antistatic agent used in the layer (a) of the multilayer film of the present invention is 50 to 95% by weight.
(That is, the weight ratio of the surfactant component (B) having a molecular weight of less than 400 is 50 to 5% by weight), and preferably the weight ratio of the surfactant component (A) is 50 to 80% by weight.
(That is, the weight ratio of the surfactant component (B) having a molecular weight of less than 400 is 50 to 20% by weight.)

The compounding amount of the antistatic agent used in the layer (a) of the multilayer film of the present invention is from 0.05 to 100 parts by weight based on 100 parts by weight of the ethylene-α-olefin copolymer (A).
2 parts by weight. When the amount of the antistatic agent is less than 0.05 part by weight with respect to 100 parts by weight of the copolymer (A), the antistatic property may be insufficient. Properties and anti-blocking properties may be insufficient.

The ethylene homopolymer used in the layer (b) of the multilayer film of the present invention is a polymer obtained by polymerizing ethylene alone. Further, an ethylene-α-olefin copolymer (B) comprising ethylene used in the (b) layer and an α-olefin having 3 to 12 carbon atoms.
The α-olefin having 3 to 12 carbon atoms, the content of the α-olefin and the ethylene-α-olefin copolymer (B) are the same as those of the above-mentioned ethylene-α-olefin copolymer (A). Similar ones can be mentioned.

The ethylene used in the present invention is ethylene and α-olefin having 3 to 12 carbon atoms.
-The density of the olefin copolymer (B) is 926 to 970K;
g / m ³ , preferably 930-970 Kg / m ³ , more preferably 940-970 Kg / m ³ .

The density of the copolymer (B) is 926 kg / m ³
If it is less than 3, the antistatic agent migrates to the layer (b) containing the copolymer (B), and the antistatic property may be insufficient or the adhesive strength may be reduced, and the density may be 970 kg.
If it exceeds / m ³ , the flexibility of the obtained multilayer film may be insufficient, or the handling properties may be reduced due to impact strength or curl (warpage).

The density of the ethylene-α-olefin copolymer (B) is higher than the density of the ethylene-α-olefin copolymer (A) by 5 kg / m ³ or more.
(That is, the difference in density between the ethylene-α-olefin copolymer (B) and the ethylene-α-olefin copolymer (A) is 5K.
g / m ³ or more. )

When the density of the copolymer (B) is not higher than the density of the copolymer (A) by 5 kg / m ³ or more (that is, the density difference between the copolymer (B) and the copolymer (A) is not If it is less than 5 kg / m ³ ), the low-temperature heat sealing property, the low-temperature hot tack property, and the mechanical strength of the film may not be satisfied at the same time, or the antistatic property may decrease.

Ethylene-α-olefin copolymer (B)
Has a melt flow rate of 0.5 to 30 g / 10 min, preferably 0.5 to 20 g / 10 min, and more preferably 0.5 to 10 g / 10 min.

If the melt flow rate of the copolymer (B) is less than 0.5 g / 10 minutes, the extrusion load in film forming becomes high and the extrusion processability may be insufficient. If it exceeds, the strength of the film may be insufficient.

The method for producing the ethylene homopolymer and the ethylene-α-olefin copolymer (B) for use in the layer (b) of the multilayer film of the present invention is not particularly limited, and a known polymerization method can be used. A production method by a known polymerization method using a catalyst may be mentioned, for example, the production method of the above-mentioned ethylene-α-olefin copolymer (A).

The multilayer film of the present invention preferably has a density of 870 to 930 Kg / m ³ and a density of 5 kg / m ³ from the density of the ethylene-α-olefin copolymer (B) from the viewpoint of bleed control of the antistatic agent. ³ or lower, a melt flow rate of 0.5~30g ethylene and carbon atoms is / 10 min containing ethylene -α- olefin copolymer consisting of 3-12 α- olefin (C) (c) It is a multilayer film having a layer as an intermediate layer between a layer (a) and a layer (b).

Ethylene-α- used in the layer (c)
Α having 3 to 12 carbon atoms in the olefin copolymer (C)
-Olefin, α-olefin content and ethylene-
Examples of the α-olefin copolymer (C) include the same as those of the above-mentioned ethylene-α-olefin copolymer (A).

The method for producing the ethylene-α-olefin copolymer (C) used in the layer (c) is as follows.
There is no particular limitation, and a production method based on a known polymerization method using a known polymerization catalyst may be used. For example, the production method for the above-described ethylene-α-olefin copolymer (A) may be used.

The ethylene-α-olefin copolymers (A), (B) and (C) used in the present invention may contain other resins, if necessary, as long as the objects and effects of the present invention are not impaired. Other additives such as stabilizers, lubricants, processability improvers, and antiblocking agents may be added.

Other resins include, for example, a branched low-density polyethylene obtained by a high-pressure radical polymerization method from the viewpoint of improving processability, and the production method thereof is generally a tank reactor or a tube. Polymerization pressure of 140 to 300 in the presence of a radical generator
Examples include a method of polymerizing ethylene under the conditions of PMa and a polymerization temperature of 200 to 300 ° C. The average molecular weight, molecular weight distribution, long-chain branching degree, and the like can be controlled by the above polymerization conditions. In order to adjust the melt flow rate, a hydrocarbon such as hydrogen, methane, or ethane may be used as a molecular weight regulator.

As the stabilizer, for example, 2,6-di-t
-Butyl-p-cresol (BHT), tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (trade name: IRG
ANOX1010, manufactured by Ciba Geigy), n-octadecyl-3- (4'-hydroxy-3,5'-di-t-butylphenyl) propionate (trade name: IRGANO
X1076, manufactured by Ciba-Geigy) and phosphites such as bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite and tris (2,4-di-butylphenyl) phosphite. Stabilizers and the like.

Examples of the lubricant include higher fatty acid amides and higher fatty acid esters. Examples of the processability improver include fatty acid metal salts such as calcium stearate. Examples of the anti-blocking agent include: Silica, calcium carbonate, talc and the like.

The antistatic agent comprising the ethylene-α-olefin copolymer (A), the surfactant component (A) and the surfactant component (B) used in the layer (a) of the multilayer film of the present invention. Examples of a mixing method and a method of mixing other resins and other additives added as needed to the ethylene-α-olefin copolymers (A), (B), and (C) include ethylene. A method in which an antistatic agent, another resin, and other additives are previously melt-kneaded with the α-olefin copolymer (A), (B), and (C), an antistatic agent, another resin, and other additives. For example, a method of preparing at least one or more master batches of the agents and dry blending them can be used. As an apparatus used for the method of melt kneading, for example, a single screw extruder, a twin screw extruder,
Banbury mixers, mixers such as hot rolls,
Examples of an apparatus used for the dry blending method include a blender such as a Henschel mixer and a tumbler mixer.

The multilayer film of the present invention is preferably a multilayer film for lamination. Examples of the substrate on which the multilayer film of the present invention is laminated include polymers, paper, paperboard, woven fabric, and aluminum foil that can be formed into a film. These substrates may be used alone.
More than one species may be used in combination. Examples of the polymer that can be formed into a film include polyamide resins such as nylon 6, nylon 66, nylon 11, and nylon 12, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polypropylene, poly-butene-1, and the like.
Poly-4 methylpentene-1, polyethylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, polyolefin resin such as ionomer, polyvinylidene chloride,
Examples thereof include polyvinyl chloride, polystyrene, polyvinyl alcohol, and ethylene-vinyl alcohol copolymer.

The base material may be a stretched film. Examples of the stretched film include a uniaxially stretched film and a biaxially stretched film. Examples of the material used for the stretched film include polyamide resin and polyamide resin. Examples include polyester resin and polypropylene.

The thickness of the multilayer film of the present invention is not particularly limited, but is usually 1 to 500 μm, preferably 10 to 100 μm. The thickness of the substrate layer is not particularly limited, and is arbitrarily selected according to the purpose. When an adhesive layer is provided between the base material and the (b) layer to bond the base material and the (b) layer, the thickness of the (b) layer is as follows.
From the viewpoint of suppressing migration of the antistatic agent to the adhesive layer and reduction in adhesive strength, the thickness is preferably 5 μm or more,
More preferably, it is 10 μm or more.

The method for producing the multilayer film of the present invention and the film obtained by laminating the multilayer film of the present invention on a substrate are not particularly limited, and include known methods, such as an inflation method and a T-die method. And the like.

The inflation method is a method of coextrusion or extrusion coating (also referred to as extrusion lamination) using an inflation film manufacturing apparatus. For example, a resin melt-kneaded by an extruder passes through a circular slit of a die. In this method, a film (usually air) is blown into a resin extruded into a tube, and the pressure of the blown gas is adjusted to produce a film having a wide range of width. The ratio of the width of the film to the diameter of the circular slit is the blow-up ratio (B
UR), and the thickness of the film is adjusted by the resin extrusion speed and the selection of the BUR. The extruded tubular resin is cooled by a gas (usually air) and / or a liquid (usually water) from the outside.

The T-die method is also called a casting method, and is a method of co-extrusion or extrusion coating (also referred to as extrusion lamination) using a T-die film manufacturing apparatus or the like.
For example, there is a method in which a resin melt-kneaded by an extruder is extruded through parallel slits of a die, is brought into contact with a roll through which a coolant such as water passes, and is cooled to produce a film.
The T-die method can generally produce a film having good transparency and high thickness accuracy. The thickness of the film is adjusted by selecting the resin extrusion speed and the film take-up speed.

The multilayer film of the present invention and the film obtained by laminating the multilayer film of the present invention on a substrate may be subjected to a corona discharge treatment, a plasma discharge treatment, a flame treatment or the like on one or both sides of the film during film formation. . When these treatments are performed, bleeding of the antistatic agent to the surface is promoted, and the surface is more uniformly wetted by the antistatic agent, so that the antistatic effect is quickly exhibited.

The multilayer film of the present invention can be used as a packaging film for various products such as a food packaging film, an electric part, and a chemical. As a food packaging film, for example, konjac, food packaging film packaged with water such as pickles, milk, sake, soy sauce and other liquid food packaging film, confectionery dried Examples of the film include a packaging film for foods and a packaging film for processed meats such as ham and sausage.

[0052]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Measurement and evaluation of physical properties of the ethylene-α-olefin copolymer and the multilayer film used in Examples and Comparative Examples were performed according to the following methods.

(1) Density (d, unit: Kg / m ³ ) Measured according to the method specified in JIS K6760-1981. (2) Melt flow rate (MFR, unit: g / 10
Min) Measured according to the method specified in JIS K6760-1981. The load is 2.16 kg and the temperature is 190
° C.

(3) Composition distribution variation coefficient (Cx) Measured using a multifunctional LC manufactured by Tosoh Corporation. The ethylene-α-olefin copolymer used in the present invention is treated at a predetermined temperature of 14.
Dissolve (concentration: 0.2 g / 20 ml) in orthodichlorobenzene (ODCB) solvent heated to 5 ° C, put into a column filled with sea sand in a column oven, and raise the temperature of the oven to 40 ° C / 60 min. To 125 ° C and 125
The temperature was lowered from C to -15 C over 14 hours. continue,
The temperature was raised at a rate of 10 ° C./60 minutes, raised to 125 ° C., and the relative concentration and branching degree of the copolymer flowing out during that time were measured by FT-IR connected to a column. Data is 10 ° C
7 points were captured at regular intervals. The temperature was raised to the final temperature while obtaining the relative concentration of the copolymer flowing out at each set temperature and the degree of branching (SCB) per 1000 main chain carbons. However, the relationship between each elution temperature and the degree of branching followed the following (Equation 5) regardless of the type of comonomer. Also, S
No elution was performed at a temperature where CB was negative. SCB = −0.7322 × elution temperature (° C.) + 70.68 (Equation 5) A composition distribution curve is obtained from the obtained relative concentration and the degree of branching, and the average short-chain degree of branching per 1000 carbons (S
CBave. ) And the standard deviation (σ) of the composition distribution, and the composition distribution variation coefficient Cx representing the width of the distribution was calculated from the following (Equation 1). Cx = σ / SCBave. (Equation 1) Average degree of short-chain branching (SCBave.) = {N (i) · W
(I) N (i): Degree of short-chain branching at i-th data sampling point W (i): Relative density at i-th data sampling point That is, ΣW (i) = 1 Standard deviation (σ) of composition distribution = ｛Σ (N (i) -SCBav
e. ) ²・ W (i)｝ ^0.5

(4) Cold xylene soluble part (a, unit:% by weight) US code of federal regulations, Food and Drugs
Measured according to the method specified in 175.1520 of Administration.

(5) Antistatic Property (5-1) Surface Resistivity (ρs, Unit: Ω) Measurement was made after processing the sample and storing it at room temperature for one week.
After conditioning for 16 hours or more at a temperature of ± 2 ° C. and a relative humidity of 50 ± 5%, the surface resistance was measured using a SM-10E ultra-insulation meter manufactured by Toa Denpa Kogyo. Next, JIS-
The surface resistivity (ρs) was determined according to the following equation described in K6911. ρs = π (D ₂ + D ₁ ) Rs / (D ₂ −D ₁ ) [where, ρs is the surface resistivity (Ω), D ₁ is the outer diameter of the inner circle of the surface electrode (cm), and D ₂ is the surface Inner diameter of the annular electrode (c
m) and Rs represent surface resistance (Ω), and π (pi) was set to 3.14. ]

(5-2) Half-life of charged voltage (unit: sec)
c) Apply a voltage to the sample at a voltage of 10 kV for 1 minute at a distance of 1 cm using a static honest meter (manufactured by Shishido Shokai), charge the sample, and charge the sample. Asked.

Examples 1 to 3 and Comparative Examples 1 and 2 The ethylene-α-olefin copolymer (A1) used in the examples or comparative examples is shown in Table 1, and the ethylene-α-olefin copolymer (B1), Table 2 shows (B2) and the ethylene homopolymer (B3), and Table 3 shows the branched low-density polyethylene obtained by the high-pressure radical polymerization method. Further, Table 4 shows the surfactant component (A) and the surfactant component (B) used in Examples and Comparative Examples.

(Blending amount of each component) Blending of each component in (a) layer (seal layer), (b) layer (laminate layer) and (c) layer (intermediate layer) of multilayer films of Examples and Comparative Examples The amounts are shown in Tables 5-9. Diatomaceous earth having an average particle size of 5 μm was used as an anti-blocking agent.

(Mixing of Components and Molding of Multilayer Film) The components shown in Tables 5 to 9 were mixed with a tumble mixer, and then each of the components used for the (a), (b) and (c) layers was prepared. A mixture of 150 mmφ, lip opening 2.0 mm3
Layer co-extrusion inflation molding machine (50mmφ extruder 3
The processing temperature was 170 ° C., the blow-up ratio was 2.12, the extrusion rate was 35 kg / hr, the film thickness was 50 μm, and the thickness ratio of each layer ((a) :( c):
(B)) forming a film under the condition of 1: 3: 1,
45 dyn / c continuously on the surface of layer (b) side of the film
m to give a multilayer polyethylene film.

(Dry lamination composite film) Using a test coater, the above-mentioned multilayer polyethylene film one week after processing was applied to a polyether-based adhesive (main agent: Toyo Morton AD30) so as to be ² g / cm ^2.
8, curing agent: Oriented Morton CAT8B) coated with a stretched nylon base film (emblem, manufactured by Unitika Ltd.) having a thickness of 15 μm and aged at 40 ° C. for 2 days to obtain a dry lamination composite film.

The antistatic properties were evaluated by measuring the surface resistivity and the half-life of the charged voltage of the surfaces of the obtained multilayer polyethylene film and dry lamination composite film. Table 10 shows the evaluation results of the antistatic properties.

[0063]

[Table 1] (Note 1) a '= (4.8 × 10 ^-5 ) × (950-d) ³ + (10 ^-6 ) × (950-
d) ⁴ + 1 A1: Ethylene-hexene-1 copolymer (manufactured by Nippon Evolu Co., Ltd., sold by Sumitomo Chemical Co., Ltd., Sumikasen E,
FV205)

[0064]

[Table 2] B1: Ethylene-hexene-1 copolymer (manufactured by Nippon Evolu Co., Ltd., sales of Sumitomo Chemical Co., Ltd., Sumikasen E,
FV404) B2: Ethylene-hexene-1 copolymer (Sumitomo Chemical Co., Ltd., Sumikasen α, CS8053) B3: High density polyethylene (Idemitsu Petrochemical Co., Ltd., Idemitsu polyethylene, 230J)

[0065]

[Table 3] Branched low-density polyethylene: manufactured by Sumitomo Chemical Co., Ltd., high-pressure LDPE, Sumikasen CE2575

[0066]

[Table 4]

[0067]

[Table 5]

[0068]

[Table 6]

[0069]

[Table 7]

[0070]

[Table 8]

[0071]

[Table 9]

[0072]

[Table 10]

Examples 1 to 3 satisfying the requirements of the present invention include:
It turns out that it is what is excellent in antistatic property. In contrast, it can be seen that Comparative Examples 1 and 2, which do not satisfy the surfactant component (A) and the surfactant component (B), which are the requirements of the present invention, have insufficient antistatic properties.

[0074]

As described above, according to the present invention,
A multilayer film excellent in antistatic property and a product excellent in antistatic property obtained by laminating the multilayer film can be obtained.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Satoru Koyama 5-1, Anesaki Beach, Ichihara City, Chiba Prefecture Sumitomo Chemical Co., Ltd. F-term (reference) 4F100 AK04B AK62A AK62B AL01A AL05A AL05B BA02 BA07 CA18A CA19 EH20 EJ38 EJ55 GB15 JA06A JA06B JA07A JA13A JA13B JG03 JG03A YY00A YY00B 4J002 BB051 BB151 EH046 EH056 EP017 FD030 FD106 FD107 FD170 FD316 FD317

Claims (6)

[Claims] An ethylene-α-olefin copolymer comprising ethylene having a density of 860 to 925 Kg / m ³ and a melt flow rate of 0.5 to 30 g / 10 minutes and an α-olefin having 3 to 12 carbon atoms. The surfactant component (A) having a molecular weight of 400 or more and 50 to 95% by weight and the surfactant component (B) having a molecular weight of less than 400 are 50 to 5% by weight based on 100 parts by weight of the combined (A). (A) layer containing 0.05 to 2 parts by weight of an antistatic agent;
In 6~970Kg / m ^3, the ethylene -α- olefin copolymer (A) high 5Kg / m ³ or more than the density of melt flow - ethylene homopolymer rate is 0.5 to 30 g / 10 min or ethylene and 3 to 12 carbon atoms
A multilayer film comprising at least two layers of the layer (b) containing the ethylene-α-olefin copolymer (B) composed of the above α-olefin. 2. The multilayer film according to claim 1, wherein the surfactant component (A) is a polyglycerin fatty acid ester. 3. The multilayer film according to claim 1, wherein the surfactant component (B) is an alkyl diethanolamide. 4. An antistatic agent comprising a surfactant component (A) 50 to
2. The multilayer film according to claim 1, comprising 80% by weight and 50 to 20% by weight of the surfactant component (B). 5. A density of 870 to 930 kg / m ^3, which is 5 kg higher than the density of the ethylene-α-olefin copolymer (B).
/ M ³ or more, melt flow rate is 0.5 to 30 g
(A) layer and (b) using the (c) layer containing an ethylene-α-olefin copolymer (C) composed of ethylene having a length of / 10 minutes and an α-olefin having 3 to 12 carbon atoms as an intermediate layer. The multilayer film according to claim 1, wherein the multilayer film is provided between layers. 6. The multilayer film according to claim 1, which is used for lamination.