JP2002114821A - Polyethylene film and polyethylene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously improve the slip resistance and the anti-blocking property while maintaining the impact resistance, pinhole resistance, low-temperature heat sealability, low odor and heat resistance, which are the characteristics of homogeneous catalyst LLDPE. Provided are a polyethylene-based film that satisfies, a product obtained by using the polyethylene-based film, and a polyethylene-based resin composition that can easily produce the film. SOLUTION: It is composed of ethylene and α-olefin having a certain number of carbon atoms, a melt flow rate is in a certain range, a density is in a certain range, a molecular weight distribution is in a certain range, and a composition distribution variation coefficient is A polyethylene film having a specific range of 45 ° gloss obtained using an ethylene-α-olefin copolymer having a specific range, a product obtained using the polyethylene film, and
A polyethylene-based resin composition containing the ethylene-α-olefin copolymer and an ethylene-based polymer having a density within a certain range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyethylene film, a multilayer film obtained using the polyethylene film, an interior bag for a bag-in-box, a polyglove, and a polyethylene resin composition.
More specifically, while maintaining the impact resistance, pinhole resistance, bending resistance, low-temperature heat sealability, low odor, and heat resistance, characteristics of homogeneous catalyst linear low-density polyethylene (LLDPE), sliding The present invention relates to a polyethylene film having excellent properties and anti-blocking properties, a multilayer film obtained using the polyethylene film, an interior bag for a bag-in-box, a polyglove, and a polyethylene resin composition from which the film can be easily produced. Things.

[0002]

2. Description of the Related Art Films are one of uses of a polyethylene resin or a composition comprising the same, and a typical use of the films is a packaging use. Conventionally, impact resistance, low-temperature heat sealability and anti-blocking properties have been considered important as properties of packaging films, but in recent years, the range of applications for films has been expanding, so in addition to these properties, Films that can simultaneously satisfy various properties such as pinhole resistance, slipperiness, and heat resistance that can withstand hot filling performed to ensure hygiene of contents have been required. .

As a method for improving both the anti-blocking property and the pinhole resistance of a film, for example, Japanese Patent Application Laid-Open No.
JP-A-293052 discloses an ethylene-α-olefin copolymer having a specific structure obtained using a metallocene catalyst or the like and an ultra-low-density ethylene-α-olefin having a specific structure.
A film containing a resin composition comprising an olefin copolymer as a main component is disclosed, and the film has a required bending resistance, pinhole resistance, and anti-blocking property required for a bag-in-box film for containing a liquid. It is described as being excellent.

It is known that when a homogeneous polyethylene typified by an ethylene-α-olefin copolymer obtained using a metallocene catalyst is used for a film, the anti-blocking property of the film is improved. However, a film made of an ethylene-α-olefin copolymer obtained using a metallocene catalyst has, for example, a density of 0.8.
Ultra low density products such as 90 g / cm ³ have low rigidity,
Since the surface is smooth enough to increase the friction between the films, the slipperiness is remarkably reduced, and the resistance is better than that of a film made of an ethylene-α-olefin copolymer obtained using a Ziegler catalyst. Also about the blocking property, when the bag made of the film or the like is filled with slightly higher temperature contents, the bag obtained using a film made of an ethylene-α-olefin copolymer obtained using a Ziegler-based catalyst or the like is used. It has been clarified that the anti-blocking property is lower than that in the case of filling contents having a slightly higher temperature.

As a method for improving the slip property of a film,
For example, Japanese Unexamined Patent Publication No. Hei 9-132270 discloses a homogeneous LLDPE by controlling the surface roughness of a film made of an ethylene-α-olefin copolymer obtained from a homogeneous catalyst to a Ra value of 1 to 5 μm. While maintaining the impact strength, pinhole resistance, low-temperature heat sealability and low odor properties that are characteristic properties of the method, a method for improving the slip property is disclosed, and a specific method for controlling the surface roughness is disclosed. As a method, there are a method of cooling and solidifying a molten resin film extruded at the time of T-die processing between a cooling roll and a nip roll whose surface is mat-like, and a method of forming a film formed at the time of inflation molding by matte surface. Through the heating roll
A method for matting the film surface is described. However, such a method roughens the surface of the film by the roll, so that the surface of the film becomes rough, and it is necessary to newly prepare a cooling roll or a heating roll having a mat-like surface. It has been desired to improve the slipperiness without giving the surface a rough feel, and further, in terms of equipment and productivity.

As a method for improving the slipperiness and the antiblocking property, a method of adding an antiblocking agent and a lubricant is known. However, a film for a bag-in-box, a polyglove made of the film, and some other materials are used. In applications, since these additives have an unfavorable effect on the performance of the product, it is desired to eliminate the additive or reduce it as much as possible to provide a product excellent in slipperiness and anti-blocking property.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a homogeneous catalyst system LLDPE, which is characterized by impact strength, pinhole resistance,
Polyethylene film that simultaneously satisfies slipperiness and anti-blocking properties while maintaining low-temperature heat sealability, low odor and heat resistance, multilayer film obtained using the polyethylene film, interior bag for bag-in-box, poly An object of the present invention is to provide a glove and a polyethylene resin composition from which a film thereof can be easily produced.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that ethylene and an α-olefin having a certain number of carbon atoms are contained, the melt flow rate is within a certain range,
Ethylene-α in which the density is in a certain range, the molecular weight distribution is in a specific range, and the composition distribution variation coefficient is in a specific range.
-Polyethylene film having a specific range of 45 ° gloss obtained using the olefin copolymer,

And α in which ethylene and carbon number are within a certain range.
-Consisting of olefins, the melt flow rate is in a certain range, the density is in a certain range, the molecular weight distribution is in a certain range, the composition distribution variation coefficient is in a certain range, and the weight ratio is in a certain range. An ethylene-α-olefin copolymer, and a 45 ° gloss obtained using a polyethylene-based resin composition containing an ethylene-based polymer in which the density is in a certain range and the weight ratio is in a certain range is a specific range. A polyethylene-based film,

And α in which ethylene and carbon number are within a certain range.
-Consisting of olefins, the melt flow rate is in a certain range, the density is in a certain range, the molecular weight distribution is in a certain range, the composition distribution variation coefficient is in a certain range, and the weight ratio is in a certain range. The ethylene-α-olefin copolymer and the melt flow rate are within a certain range,
An ethylene polymer which is an ethylene homopolymer or an ethylene-α-olefin copolymer in which the density is in a certain range, the specific value of [g] * is in a certain range, and the weight ratio is in a certain range. A polyethylene film having a specific range of 45 ° gloss obtained using a polyethylene resin composition containing:

[0011] Further, a multilayer film in which a layer comprising the above-mentioned polyethylene film is disposed on at least one surface, an inner bag for a bag-in-box obtained by using the above-mentioned polyethylene film or the above-mentioned multilayer film, and a plastic gloves,

And α in which ethylene and carbon number are within a certain range.
-Consisting of olefins, the melt flow rate is in a certain range, the density is in a certain range, the molecular weight distribution is in a certain range, the composition distribution variation coefficient is in a certain range, and the weight ratio is in a certain range. The ethylene-α-olefin copolymer and the melt flow rate are within a certain range,
An ethylene polymer which is an ethylene homopolymer or an ethylene-α-olefin copolymer in which the density is in a certain range, the specific value of [g] * is in a certain range, and the weight ratio is in a certain range. A polyethylene resin composition containing
The inventors have found that the above problems can be solved, and have completed the present invention.

That is, one aspect of the present invention comprises ethylene and an α-olefin having 3 to 18 carbon atoms, a melt flow rate of 0.05 to 50 g / 10 min, and a density of 870.
９925 kg / m ³ , the molecular weight distribution M determined by GPC
w / Mn is 1.5 to 7.0, and the following formula (I) Cx = σ / SCBave. (I) (where σ represents the standard deviation of the composition distribution, and SCBave.
Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C). The present invention relates to a polyethylene-based film having a 45 ° gloss of 0 to 80% obtained by using an ethylene-α-olefin copolymer (A) having a composition distribution variation coefficient Cx of 0.5 or less. Yes,

In the second aspect of the present invention, ethylene and C 3 -C 18
Α-olefin having a melt flow rate of 0.1.
05 to 50 g / 10 min, density 870 to 925 k
g / m ³ , and the molecular weight distribution Mw / Mn determined by GPC.
Is 1.5 to 7.0, and the following equation (I) Cx = σ / SCBave. (I) (where σ represents the standard deviation of the composition distribution, and SCBave.
Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C). ), The ethylene-α-olefin copolymer (A) having a composition distribution variation coefficient Cx of 0.5 or less is 40 to 99.5% by weight, and an ethylene-based weight having a density of 935 kg / m ³ or more. (B) a polyethylene film having a 45 ° gloss of 0 to 80% obtained using a polyethylene resin composition containing 60 to 0.5% by weight,

The third aspect of the present invention relates to ethylene and ethylene having 3 to 18 carbon atoms.
Α-olefin having a melt flow rate of 0.1.
05 to 50 g / 10 min, density 870 to 925 k
g / m ³ , and the molecular weight distribution Mw / Mn determined by GPC.
Is 1.5 to 7.0, and the following equation (I) Cx = σ / SCBave. (I) (where σ represents the standard deviation of the composition distribution, and SCBave.
Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C). ) The ethylene-α-olefin copolymer (A) having a composition distribution variation coefficient Cx of 0.5 or less is 40 to 99.5% by weight, and the melt flow rate is 0.1 to 300 g / 10 min. And the density is 935 kg / m ³ or more, and the following formula (II) [g] * = [η] / [η] l (II) (where [η] is the limit measured with a tetralin solution at 135 ° C.) [Η] l is the limiting viscosity of linear polyethylene having the same weight average molecular weight as the weight average molecular weight [Mw] determined by the GPC-ALLS method,
It is determined by the following equation (III). [Η] l = 4.86 × 10 ⁻⁴ [Mw] ^0.705
(III) The value of [g] * defined in) is 0.4 to
Ethylene homopolymer or ethylene-α-1.0
Ethylene polymer (B) 60 which is an olefin copolymer
45-gloss obtained using a polyethylene-based resin composition containing 0.5 to 0.5% by weight is a polyethylene-based film is 0 to 80%,

A fourth aspect of the present invention relates to a multilayer film in which a layer made of the above polyethylene film is disposed on at least one surface,

The fifth aspect of the present invention relates to an interior bag for a bag-in-box obtained by using the above-mentioned polyethylene film or the above-mentioned multilayer film,

A sixth aspect of the present invention relates to a polyglove obtained using the above-mentioned polyethylene film or the above-mentioned multilayer film,

The seventh aspect of the present invention relates to ethylene and ethylene having 3 to 18 carbon atoms.
Α-olefin having a melt flow rate of 0.1.
05 to 50 g / 10 min, density 870 to 925 k
g / m ³ , and the molecular weight distribution Mw / Mn determined by GPC.
Is 1.5 to 7.0, and the following equation (I) Cx = σ / SCBave. (I) (where σ represents the standard deviation of the composition distribution, and SCBave.
Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C). ) The ethylene-α-olefin copolymer (A) having a composition distribution variation coefficient Cx of 0.5 or less is 40 to 99.5% by weight, and the melt flow rate is 0.1 to 300 g / 10 min. And the density is 935 kg / m ³ or more, and the following formula (II) [g] * = [η] / [η] l (II) (where [η] is the limit measured with a tetralin solution at 135 ° C.) [Η] l is the limiting viscosity of linear polyethylene having the same weight average molecular weight as the weight average molecular weight [Mw] determined by the GPC-ALLS method,
It is determined by the following equation (III). [Η] l = 4.86 × 10 ⁻⁴ [Mw] ^0.705
(III) The value of [g] * defined in) is 0.4 to
Ethylene homopolymer or ethylene-α-1.0
Ethylene polymer (B) 60 which is an olefin copolymer
About 0.5% by weight according to the polyethylene resin composition. Hereinafter, the present invention will be described in detail.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Ethylene-α used in the present invention
-Olefin copolymer (A) is defined as ethylene and carbon number 3
To 18 α-olefins. α-
Examples of the olefin include propylene, butene-
1, hexene-1, 4-methylpentene-1, octene-1, decene-1 and the like, and preferably butene-
1, hexene-1, 4-methylpentene-1 and octene-1. Further, two or more α-olefins may be used in combination as needed.

The ethylene-α-olefin copolymer (A) used in the present invention includes, for example, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, ethylene -4-methylpentene-1 copolymer, ethylene-octene-1 copolymer, ethylene-propylene-butene-1 copolymer and the like, preferably ethylene-butene-1 copolymer, ethylene-hexene- 1 copolymer, ethylene-octene
1 copolymer.

The melt flow rate of the ethylene-α-olefin copolymer (A) used in the present invention is 0.05
５０50 g / 10 min, preferably 0.1-20 g /
10 minutes, more preferably 0.5 to 20 g / 10
Minutes. The melt flow rate of the copolymer (A) is 0.5.
When it is less than 05 g / 10 minutes, processability may be poor, and the melt flow rate of the copolymer (A) may be 50 g / 1.
If the time exceeds 0 minutes, the strength and processability of the film may be poor.

The density of the ethylene-α-olefin copolymer (A) used in the present invention is from 870 to 925 kg / m
³ , preferably 885 to 915 kg / m ³ ,
More preferably from 890~908kg / m ^3. When the density of the copolymer (A) is less than 870 kg / m ³ , the film may be inferior in anti-blocking properties and slipperiness. When the density of the copolymer (A) exceeds 925 kg / m ³ , The film may have poor pinhole resistance and impact resistance.

The molecular weight distribution Mw / Gw of the ethylene-α-olefin copolymer (A) used in the present invention determined by GPC.
Mn is from 1.5 to 7.0, preferably from 1.5 to 7.0.
5.0, and more preferably 2.0 to 3.0. Molecular weight distribution Mw / of copolymer (A) determined by GPC
When Mn is less than 1.5, the processability may be poor, and when the molecular weight distribution Mw / Mn exceeds 7.0, the strength and anti-blocking properties of the film may be reduced.

The composition distribution variation coefficient Cx represented by the following formula (I) of the ethylene-α-olefin copolymer (A) used in the present invention is 0.5 or less, preferably 0.2 to 0.2.
0.4, and more preferably 0.2 to 0.35. Cx = σ / SCBave. (I) (where σ represents the standard deviation of the composition distribution, and SCBave.
Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C). When the composition distribution variation coefficient Cx of the copolymer (A) exceeds 0.5, the strength of the film may be reduced or the anti-blocking property may be poor.

In general, the coefficient of variation Cx of the composition distribution of an ethylene-α-olefin copolymer indicates the average composition and the breadth of the composition distribution of the ethylene-α-olefin copolymer, and the standard deviation of the composition distribution. and the average value of the number of short-chain branches per 1000 carbon atoms (1000C) (1/10
00C), and is calculated from σ / SCBave. The standard deviation σ of the composition distribution is as follows: an ethylene-α-olefin copolymer dissolved in a solvent at a predetermined temperature is put into a column filled with a carrier such as sea sand in a column oven, and the temperature of the oven is lowered under a certain condition. After allowing the copolymer to precipitate on the carrier, the temperature was increased,
The copolymer was distilled at each set temperature, and obtained from a composition distribution curve obtained from the relative concentration and branching degree of the copolymer distilled at each temperature measured using FT-IR, SCBave. Which is the average value (1 / 1000C) of the number of short-chain branches per 1000 branches (1000C). Is the FT-I
It is obtained from the degree of branching measured using R.

As a method for producing the ethylene-α-olefin copolymer (A) used in the present invention, a method for producing the ethylene-α-olefin copolymer (A) by a known polymerization method using a homogeneous catalyst can be mentioned. As the homogeneous catalyst, for example, a metallocene catalyst,
Nonmetallocene-based catalysts Those skilled in the art include, preferably, metallocene-based catalysts, that is, ethylene produced by using a metallocene-based catalyst as the ethylene-α-olefin copolymer (A) used in the present invention. -Α-olefin copolymer.

The metallocene catalyst is a catalyst system using a transition metal compound having a group having a cyclopentadiene-type anion skeleton. The transition metal compound having a group having a cyclopentadiene-type anion skeleton generally has a general formula during ML _a X _na (wherein, M is a transition metal atom of group 4 or lanthanide series of the periodic table of elements .L is a group containing a group or a hetero atom having a cyclopentadiene type anion skeleton, at least One is a group having a cyclopentadiene-type anion skeleton.
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 is an integer satisfying 0 <a ≦ n. ) And can be used alone or in combination of two or more. Further, the metallocene-based catalyst includes, in addition to the transition metal compound having a group having a cyclopentadiene-type anion skeleton, an organoaluminum compound including an alumoxane compound, and / or an ionic compound such as trityl borate and anilinium borate, and / or It is used in combination with a particulate carrier including 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.

The polymerization method of the ethylene-α-olefin copolymer (A) used in the present invention is not particularly limited, and for example, the presence or absence of a gas-solid in the presence or absence of a solvent. Below, a method of polymerizing ethylene and an α-olefin having 3 to 18 carbon atoms in the presence of a liquid-solid or in a uniform liquid phase, and the like, for example, a gas phase polymerization method, a solution polymerization method, and a slurry polymerization method And high-pressure ion polymerization. The polymerization temperature is usually 30 to 300 ° C., and the polymerization pressure is normal pressure to 300 MPa.

The polyethylene film of the present invention is a film obtained using the ethylene-α-olefin copolymer (A), and a film obtained using the ethylene-α-olefin copolymer (A) alone. And a film obtained using a polyethylene-based resin composition containing an ethylene-α-olefin copolymer (A) and an ethylene-based polymer (B).

As the ethylene polymer (B) used in the present invention, an ethylene homopolymer or ethylene-
α-olefin copolymers. Ethylene-α-
The olefin copolymer is a copolymer composed of ethylene and an α-olefin, and the same ethylene-α-olefin copolymer as the above-described ethylene-α-olefin copolymer (A) can be used.

The density of the ethylene polymer (B) used in the present invention is usually from the viewpoint of the slipperiness of the film.
935 kg / m ³ or more, preferably 945 kg / m ³
m ³ or more, more preferably 950 kg / m ³ or more.

The melt flow rate of the ethylene polymer (B) used in the present invention is usually from 0.1 to 300 g from the viewpoint of the slipperiness of the film and the strength of the film.
/ 10 minutes, preferably 2 to 200 g / 10 minutes, more preferably 5 to 150 g / 10 minutes, and still more preferably 20 to 100 g / 10 minutes.

The value of [g] * defined by the following formula (II) of the ethylene polymer (B) used in the present invention is as follows:
From the viewpoint of the slipperiness of the film, it is usually 0.4 to 1.0. [G] * = [η] / [η] l (II) (where [η] is the intrinsic viscosity measured with a tetralin solution at 135 ° C., and [η] l is the weight average determined by the GPC-LALLS method) The intrinsic viscosity of a linear polyethylene having the same weight average molecular weight as the molecular weight [Mw],
It is determined by the following equation (III). [Η] l = 4.86 × 10 ⁻⁴ [Mw] ^0.705 (III))

[G] * of the ethylene polymer (B) is an index of the amount of long-chain branching. The smaller the [g] *, the greater the amount of long-chain branching. 0.0, more preferably 0.8 to 1.0, and even more preferably 0.95 to 1.0. The weight average molecular weight [Mw] of the ethylene-based polymer (B) is determined by the GPC-LALLSS method (Gel Permiation Chromatography-Low Angle Laser L).
ight scattering method). Further, for the formula (III), for example, a known literature (H.
Rachapudy, GGSmith, VRRaju, and WWGlassley,
J. Polym. Sci., Polym. Phys. Ed., 17, 1211 (1979)).

The method for producing the ethylene polymer (B) includes, for example, using a Ziegler-Natta catalyst or a metallocene catalyst, in the presence or absence of a solvent, in the presence of gas-solid, in the presence of liquid- In the presence of a solid or under a uniform liquid layer, ethylene alone, or a method of polymerizing ethylene and a small amount of an α-olefin having 3 to 18 carbon atoms to produce, for example, a gas phase polymerization method, a solution polymerization method, and a slurry method. A polymerization method, a high pressure ionic polymerization method, and the like are included. The polymerization temperature is usually 30 to 3
The polymerization pressure is from normal pressure to 300 MPa.
Further, as the ethylene-based polymer (B), a polymer selected from commercially available medium-density polyethylene or high-density polyethylene can also be used.

The polyethylene-based resin composition containing the ethylene-α-olefin copolymer (A) and the ethylene-based polymer (B) used in the present invention has flexibility, strength, impact strength and pinhole resistance of the film. Ethylene-α-olefin copolymer (A) is usually 40 to 99.5% by weight from the viewpoints of properties, low-temperature heat sealability, low odor and slipperiness.
And 60 to 0.5% by weight of an ethylene-based polymer (B), preferably 70 to 99.5% by weight of an ethylene-α-olefin copolymer (A) and 30 to 30% by weight of an ethylene-based polymer (B). To 0.5% by weight, more preferably ethylene-α-olefin copolymer (A) 8
5 to 99.5% by weight and the ethylene polymer (B) 15
Of the ethylene-α-olefin copolymer (A) 90 to 99.5.
% By weight and 10 to 0.5% by weight of the ethylene-based polymer (B).

The method for producing the polyethylene resin composition of the present invention is not particularly limited, and ethylene-α-
A method of melting and mixing the olefin copolymer (A) and the ethylene-based polymer (B) by a known method can be used. For example, a single-screw extruder, a twin-screw extruder, or a known apparatus, which is melt-mixed using a Banbury mixer or the like to produce a polyethylene-based resin composition, ethylene-α-
After mixing the respective pellets of the olefin copolymer (A) and the ethylene-based polymer (B) with a tumble mixer or the like, the mixture is supplied to a film processing machine to produce a polyethylene-based resin composition.

The ethylene-α- used in the present invention
The olefin copolymer (A) and the polyethylene resin composition may contain, if necessary, an antioxidant, a lubricant, an antiblocking agent, an antistatic agent, and a neutralizing agent as long as the objects and effects of the present invention are not impaired. And the like.

45 ° of the polyethylene film of the present invention
Gloss is 0-80%. 45 ° gloss is 45 ° gloss on at least one surface of the film, preferably 0 to 50%, more preferably 1 to 40%.
It is. The 45 ° gloss can be adjusted according to the structure of the ethylene-α-olefin copolymer (A) used in the present invention or the film production conditions (processing temperature, cooling conditions, etc.). The structure of the ethylene-α-olefin copolymer (A),
It can be adjusted by the structure of the ethylene-based polymer (B), the amount thereof, or the film production conditions (processing temperature, cooling conditions, etc.).

45 ° of the polyethylene film of the present invention
The cooling conditions for adjusting the gloss include, for example, conditions for cooling the film. The appropriate condition range depends on the size of the processing apparatus, the details of the equipment, and the processing speed (extrusion speed, film take-off speed, and the like). Although different, a method of reducing the amount of cooling air by the air ring from the normal or not blowing the air, or a method of setting the temperature of the cooling air by the air ring to a temperature higher than the normal, that is, a method of blowing the air at 30 to 50 ° C. And a method of blowing air preferably at 40 to 50 ° C. (The temperature of the cooling air by the air ring is usually 10 to 30 ° C.)

The method for producing the film of the present invention includes known processing methods such as inflation processing and T-die film processing. Generally, a film obtained by inflation processing of an ethylene-α-olefin copolymer obtained using a homogeneous catalyst system has a 45 ° gloss that is relatively easily reduced, and has good anti-blocking properties and good slip properties. As a method for producing the film of the present invention,
Preferably, it is an inflation processing method.

The film of the present invention can be used as a multilayer film in which the film is disposed on at least one surface. Further, the film of the present invention can also be used as a packaging film suitable for various uses by laminating with various substrates such as polyethylene, polypropylene and nylon.

The film of the present invention has excellent impact strength, pinhole resistance, low-temperature heat sealability, low odor transfer to liquid contents and foods, and improved anti-blocking properties and improved slip properties. It is particularly suitable for use as an interior bag for a bag-in-box or a polyglove.

The bag-in-box is a liquid container comprising an interior formed of a thin-walled molded container or a film bag having a spout and an exterior of a cardboard box, and is being widely used as a packaging container for liquid foods and industrial chemicals. In particular, the use of a film bag for the interior has been remarkably growing in recent years, and the characteristics required for the film used for the film bag are pinhole resistance against repeated fatigue during transportation, bag openability (anti-blocking property). ), Slipperiness during bag making, etc. Since the film of the present invention can satisfy these required properties, it is suitably used as an interior bag for a bag-in-box.

The demand for poly gloves is increasing as easy protective gloves to be worn for various tasks. This poly glove is formed by laminating two films and then fusing and cutting the film in the form of a hand. The characteristics required of the poly glove formed in such a manner are slipperiness during molding, hand Such properties include the flexibility to fit in, the openability when inserting a hand (anti-blocking property) and the film strength. The film of the present invention is made of a conventional solid catalyst-based LLDPE or high density polyethylene (HDP).
Since these required properties can be more sufficiently satisfied as compared with E), they are suitably used as polygloves.

[0047]

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these examples.

First, methods for measuring physical properties in the following Examples and Comparative Examples will be described. (1) Density (unit: kg / m ³ ) Measured according to the method specified in JIS K6760. (2) Melt flow rate (MFR: g / 10 min) Measured according to the method specified in JIS K6760. The load was 2.16 kg and the temperature was 190 ° C.

(3) Molecular weight distribution (Mw / Mn) Measured by gel permeation chromatography (GPC) under the following conditions. Apparatus: GPC apparatus 150C manufactured by Japan Waters Co., Ltd. Column: TSK GMH-6 manufactured by Tosoh Corporation Solvent: ortho-dichlorobenzene (ODCB) Temperature: 135 ° C Flow rate: 1 ml / min Injection concentration: 10 mg / 10 ml ODCB (injection volume 500)
μl) The weight average molecular weight Mw and the number average molecular weight Mn converted from a calibration curve using standard polystyrene were determined, and Mw / M
n was calculated.

(4) 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 an orthodichlorobenzene (ODCB) solvent heated to 5 ° C., put into a column filled with sea sand placed in a column oven, and raise the temperature of the oven to 40 ° C./60. The rate was reduced to 125 ° C at a rate of minutes and from 125 ° C to -15 ° C over 14 hours. Subsequently, the temperature was raised at a rate of 10 ° C./60 minutes,
The relative concentration and the degree of branching of the copolymer flowing out during that time were measured by FT-IR connected to a column. Data were taken at 7 points at equal intervals between 10 ° C. Relative concentration of copolymer flowing out at each set temperature and main chain carbon 10
The temperature was raised to the final temperature while obtaining the degree of branching (SCB) per 00 pieces. However, the relationship between each elution temperature and the degree of branching was determined from equation (IV) regardless of the type of comonomer. At the temperature where SCB was negative, no elution was observed. SCB = −0.7322 × elution temperature (° C.) + 70.68 (IV) A composition distribution curve was obtained from the obtained relative concentration and the degree of branching. From this curve, the average degree of short-chain branching per 1000 carbons (S
CBave.) And the standard deviation (σ) of the composition distribution, to obtain a composition distribution variation coefficient Cx representing the width of the distribution. Average short-chain branching degree (SCBave.) = ΣN (i) · W (i) (V) N (i): short-chain branching degree at i-th data sampling point W (i): at i-th data sampling point Relative concentration, ie, ΣW (i) = 1 Standard deviation of composition distribution (σ) = {Σ (N (i) -SCBave.) ² · W (i)} ^0.5 (VI)

(5) [g] * Chroma was added to a GPC device (HLC811) manufactured by Tosoh Corporation.
A LALLS apparatus (KMX-6) manufactured by Tix Co., Ltd. was connected, and the measurement was performed with a solvent of 1,2,4-trichlorobenzene, a concentration of 0.5% by weight, a temperature of 140 ° C., and a flow rate of 1 ml / min.

(6) 45 ° gloss The tubular film obtained by the inflation processing is cut open, and the gloss on the surface facing outward at the time of the processing is determined by JIS-
It was measured according to Z-8741.

(7) Surface Roughness A cylindrical film obtained by inflation processing is cut open, and the surface roughness Ra of the surface facing outward at the time of processing is defined as J.
It measured according to IS-B-0601.

(8) Anti-blocking property (opening property) Using a pair of scissors capable of cutting a continuously wound tubular film while folding it into a flat shape by inflation processing, cut it in 5 cm lengths at right angles to the winding direction. After applying a load of 40 kg / 100 cm ² to the cut film and adjusting the condition at 50 ° C. for 1 day, the openability when opening the cut with a finger was evaluated in four stages. ◎: Very good ○: Good △: Somewhat bad ×: Bad

(9) Sliding property (coefficient of static friction, unit: μ)
s) The tubular film obtained by inflation was cut open, and the coefficient of static friction (unit: μs) of the surface facing outward during the processing was measured in accordance with JIS-K-7125.
However, weight: 500 g, sliding speed: 700 mm / mi
n.

Samples The ethylene-α-olefin copolymer (A) and the ethylene polymer (B) used in Examples and Comparative Examples are shown below. A1: Dimethylsilyl (tetramethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride, triisobutylaluminum and N, N-dimethylaniliniumtetrakis (pentafluorophenyl) as metallocene catalysts ) Borate, high pressure ion polymerization (total pressure 90MP
a), an ethylene-hexene-1 copolymer obtained by polymerizing ethylene and hexene-1 (hexene-1 content: 11.1% by weight) A2: Sumikasen E FV401 manufactured by Sumitomo Chemical (metallocene ethylene) -Hexene-1 copolymer) B1: Chemiretz 1010 manufactured by Maruzen Polymer Co., Ltd. B2: Chemiletz 1150-1 manufactured by Maruzen Polymer Co., Ltd.

Example 1 90% by weight of ethylene-α-olefin copolymer (A1)
And 10% by weight of an ethylene-based polymer (B1) in a plastic bag and thoroughly mixed, and then VS20 manufactured by Tanabe Plastics Co., Ltd.
Die inflation machine (extruder screw diameter: 2
(0 mmφ, die diameter: 30 mmφ), and inflation processing was performed under the following conditions to obtain a film. Processing conditions Temperature: Extruder C1: 170 ° C, C2: 200 ° C,
C3: 200 ° C., die 200 ° C. ・ Extrusion speed: 120 g / Hr ・ Film take-off speed: 78 cm / min ・ Cooling condition: Cooling at 25 ° C. by setting the scale of the cooling blower by an air ring to 1.5. Air was blown.・ Film thickness: 20 μm ・ BUR (blow-up ratio): 1.5 Physical properties of the used ethylene-α-olefin copolymer (A1) and ethylene-based polymer (B1), cooling conditions in inflation processing, and The evaluation results (film properties) of the obtained film are shown in Table 1.

Example 2 A film was blown in the same manner as in Example 1 except that the ethylene polymer (B1) used in Example 1 was changed to the ethylene polymer (B2). I got Physical properties of the used ethylene-α-olefin copolymer (A1) and ethylene-based polymer (B2), cooling conditions in inflation processing, and
The evaluation results (film properties) of the obtained film are shown in Table 1.

Example 3 The ethylene-α-olefin copolymer (A1) used in Example 2 was replaced with the ethylene-α-olefin copolymer (A2).
The inflation process was performed in the same manner as in Example 1 except that the film was changed to a film. Table 1 shows the physical properties of the used ethylene-α-olefin copolymer (A2) and the ethylene-based polymer (B2), cooling conditions in inflation processing, and evaluation results (film physical properties) of the obtained film. Was.

Example 4 100% by weight of the ethylene-α-olefin copolymer (A2) was prepared as follows using a VS20 type inflation machine (extruder screw diameter: 20 mmφ, die diameter: 30 mmφ) manufactured by Tanabe Plastics. Inflation was performed under the conditions shown to obtain a film. Processing conditions Temperature: Extruder C1: 170 ° C, C2: 200 ° C,
C3: 200 ° C., die 200 ° C. ・ Extrusion speed: 120 g / Hr ・ Film take-up speed: 78 cm / min ・ Cooling condition: The scale of the cooling blower by the air ring was set to 0, and no cooling air was used. -Film thickness: 20 m-BUR (blow-up ratio): 1.5 Physical properties of the used ethylene- [alpha] -olefin copolymer (A2), cooling conditions in inflation processing, and
The evaluation results (film properties) of the obtained film are shown in Table 1.

Comparative Example 1 In Example 4, the ethylene-α-olefin copolymer (A2) was replaced with the ethylene-α-olefin copolymer (A1).
And the cooling conditions were changed as follows. Cooling conditions: The scale of the cooling blower using an air ring was set to 1.5, and cooling air having a temperature of 25 ° C. was blown. The film was obtained by inflation processing in the same manner as in Example 4 except that the film was changed to. Ethylene-α-olefin copolymer used (A1)
Table 1 shows the physical properties, cooling conditions in inflation processing, and evaluation results (film physical properties) of the obtained film.

Comparative Example 2 In Example 4, the cooling conditions were as follows. Cooling condition: The scale of the cooling blower using an air ring was set to 1.5, and cooling air having a temperature of 25 ° C. was blown. The film was obtained by inflation processing in the same manner as in Example 4 except that the film was changed to. Table 1 shows physical properties of the used ethylene-α-olefin copolymer (A2), cooling conditions in inflation processing, and evaluation results (film physical properties) of the obtained film.

[0063]

[Table 1]

From the above Examples and Comparative Examples, it can be seen that Examples 1-4 satisfying the requirements of the present invention are excellent in anti-blocking properties and slip properties. On the other hand, it can be seen that Comparative Examples 1 and 2, which do not satisfy the 45 ° gloss of the film, which is a requirement of the present invention, have insufficient antiblocking properties (opening properties) and slip properties (coefficient of static friction).

[0065]

As described in detail above, according to the present invention,
A polyethylene film which simultaneously satisfies the slipping property and the anti-blocking property while maintaining the impact resistance, pinhole resistance, low temperature heat sealing property, low odor property and heat resistance, which are the characteristics of the homogeneous catalyst LLDPE. A multilayer film, an interior bag for a bag-in-box, a polyglove, and a polyethylene resin composition from which the film can be easily produced can be obtained.

Continued on the front page F-term (reference) 4F071 AA15 AA16 AA17 AA80 AA82 AA88 AF23 AF32 AF53 AF59 AH04 AH19 BA01 BB06 BB09 BC01 4F100 AK01B AK06A AT00B BA02 BA07 GB15 JJ03 JL00 JL01 JL12 4J05 BB03X00 BB03X00 BB03X00 AA03Q AA04Q AA15Q AA16Q AA17Q AA19Q AA21Q CA01 CA04 DA04 DA09 DA12 DA14 DA15 DA19 DA22 DA28 DA36 DA42 DA44 DA47 DA49 DA52 DA64 FA10 FA19 FA22 JA28 JA57

Claims (10)

[Claims] (1) An ethylene-α-olefin having 3 to 18 carbon atoms having a melt flow rate of 0.05 to 50 g /
10 minutes, the density is 870-925 kg / m ³ ,
The molecular weight distribution Mw / Mn determined by GPC is 1.5 to 7.0.
And the following equation (I) Cx = σ / SCBave. (I) (where σ represents the standard deviation of the composition distribution, and SCBave.
Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C). Wherein the 45 ° gloss obtained using the ethylene-α-olefin copolymer (A) having a composition distribution variation coefficient Cx of 0.5 or less is 0 to 80%. the film. 2. An ethylene-α-olefin copolymer (A)
Is produced using a metallocene-based catalyst.
The polyethylene film according to claim 1, which is an olefin copolymer. 3. An ethylene / α-olefin having 3 to 18 carbon atoms having a melt flow rate of 0.05 to 50 g /
10 minutes, the density is 870-925 kg / m ³ ,
The molecular weight distribution Mw / Mn determined by GPC is 1.5 to 7.0.
And the following equation (I) Cx = σ / SCBave. (I) (where σ represents the standard deviation of the composition distribution, and SCBave.
Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C). ), The ethylene-α-olefin copolymer (A) having a composition distribution variation coefficient Cx of 0.5 or less is 40 to 99.5% by weight, and an ethylene-based weight having a density of 935 kg / m ³ or more. A polyethylene film characterized in that the 45 ° gloss obtained using the polyethylene resin composition containing 60 to 0.5% by weight of the combined (B) is 0 to 80%. 4. An ethylene-α-olefin copolymer (A)
Is produced using a metallocene-based catalyst.
The polyethylene film according to claim 3, which is an olefin copolymer. 5. An ethylene polymer (B) having a melt flow rate of 0.1 to 300 g / 10 min and a density of 93
5 kg / m ³ or more, and the following formula (II) [g] * = [η] / [η] l (II) (where [η] is the intrinsic viscosity measured with a tetralin solution at 135 ° C .; η] l is the limiting viscosity of linear polyethylene having the same weight average molecular weight as the weight average molecular weight [Mw] determined by the GPC-LALLS method,
It is determined by the following equation (III). [Η] l = 4.86 × 10 ⁻⁴ [Mw] ^0.705
(III) The value of [g] * defined in) is 0.4 to
Ethylene homopolymer or ethylene-α-1.0
The polyethylene film according to claim 3, which is an olefin copolymer. 6. A multilayer film comprising a layer comprising the polyethylene film according to claim 1 disposed on at least one surface. 7. An interior bag for a bag-in-box obtained by using the polyethylene film according to any one of claims 1 to 5 or the multilayer film according to claim 6. 8. A polyglove obtained by using the polyethylene film according to claim 1 or the multilayer film according to claim 6. 9. A composition comprising ethylene and an α-olefin having 3 to 18 carbon atoms and having a melt flow rate of 0.05 to 50 g /
10 minutes, the density is 870-925 kg / m ³ ,
The molecular weight distribution Mw / Mn determined by GPC is 1.5 to 7.0.
And the following equation (I) Cx = σ / SCBave. (I) (where σ represents the standard deviation of the composition distribution, and SCBave.
Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C). ) The ethylene-α-olefin copolymer (A) having a composition distribution variation coefficient Cx of 0.5 or less is 40 to 99.5% by weight, and the melt flow rate is 0.1 to 300 g / 10 min. And the density is 935 kg / m ³ or more, and the following formula (II) [g] * = [η] / [η] l (II) (where [η] is the limit measured with a tetralin solution at 135 ° C.) [Η] l is the limiting viscosity of linear polyethylene having the same weight average molecular weight as the weight average molecular weight [Mw] determined by the GPC-ALLS method,
It is determined by the following equation (III). [Η] l = 4.86 × 10 ⁻⁴ [Mw] ^0.705
(III) The value of [g] * defined in) is 0.4 to
Ethylene homopolymer or ethylene-α-1.0
Ethylene polymer (B) 60 which is an olefin copolymer
A polyethylene-based resin composition, which comprises 0.5 to 0.5% by weight. 10. The polyethylene resin composition according to claim 9, wherein the ethylene-α-olefin copolymer (A) is an ethylene-α-olefin copolymer produced using a metallocene catalyst. object.