JP2005163021A - Polyethylene-based film, laminate given by using the film, container, packaging material for packaging the container, container packaging material, and polyethylene-based resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyethylene-based film having excellent resistance to mutual adhesion and slipperiness, without causing such a fear that a content of a container, etc., is not contaminated by foreign matter, when the container, etc., is composed thereof, and excellent in an outward appearance of the film itself. <P>SOLUTION: This polyethylene-based film contains two or more kinds of polyethylene-based polymers in which at least one of constitution, density, and melt-flow rate of one of the polymers is different from the others, wherein at least one of the polyethylene-based polymers comprises a high density polyethylene, at least one of surfaces of the film has a coefficient of dynamic friction of ≤0.40, when measured by contacting areas of the surface with each other, and the surface having the coefficient of dynamic friction of ≤0.40 comprises a rough surface having a one-side external haze of ≥ 5%. It is preferable that the film does not substantially contain a lubricant, nor an anti-blocking agent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyethylene film, and a laminate, a container, a container packaging container, a container package, and an ethylene polymer composition using the film, and in particular, substantially contains a lubricant and an antiblocking agent. The present invention relates to a polyethylene-based film that is excellent in anti-adhesiveness even without being included, has no fear of foreign matter mixing into contents when a container or the like is formed, and has an excellent film appearance.

The polyethylene film is suitably used as a container for filling a container filled with food or medicine, or a container made of various plastics or metals filled with food or medicine or the like. There are various purposes for using the latter packaging for containers and packaging, for example, preventing mechanical damage such as scratches on the container, or preventing oxygen and ultraviolet light from penetrating and preventing alteration of the contents of the container. It is used for the purpose of protecting the container contents, printing the container contents, or the container contents and the handling method of the containers.
Containers and packaging for containers and packaging are obtained by forming an ethylene polymer or a composition thereof to obtain a polyethylene film, and forming the film into a desired shape (for example, a bag shape) by a thermal fusion method or the like. Is common.

Conventionally, in a polyethylene film used for a container or a package for container packaging, the films sometimes adhere to each other.
For example, while a film wound in a roll shape is stored in a warehouse or the like, the films may adhere to each other and blocking may occur. When blocking occurs, it becomes difficult to process into a good shape in the process of processing into a bag shape or the like, and the slipping of the film deteriorates, so that productivity may be lowered. In addition, after processing into a bag shape or the like, during storage until the contents are filled, the inner surfaces of the container or the package are attached to each other, the opening property is deteriorated, and the filling of the contents may be difficult. It was.

Furthermore, in recent years, from the viewpoint of safety and hygiene, containers and packages that have been packaged in packages have been increasingly subjected to high-pressure steam sterilization, and in order to improve productivity, the sterilization temperature has been increased to shorten the sterilization time. It tends to become. It goes without saying that the higher the exposure to high temperatures, the easier the mutual adhesion occurs. Especially for medical use, in order to maintain the quality of the container contents in a more stable and constant quality, the package body is decompressed to reduce the space volume between the medical container and the package body. Have been brought into close contact with each other, and high-pressure steam sterilization has been carried out under conditions where mutual adhesion tends to occur.
In particular, in the case where the package contact surface (outermost layer of the container) is made of a propylene-based polymer, in order to give the container flexibility, the propylene-based polymer having ethylene or butene-1 as a copolymerization component is used as the propylene-based polymer. Copolymers, styrene-based elastomers, and olefin-based elastomers with added elastomer components are often used, but they are composed of propylene-based copolymers and propylene-based polymers containing elastomer components and polyethylene-based films. Mutual attachment is likely to occur with the package. In particular, among propylene-based polymers, mutual adhesion is very likely to occur between a container made of a propylene / ethylene random copolymer and a package made of a polyethylene film.

Under such background, as a means for improving anti-tackiness and slipperiness of the polyethylene film, (a) an antiblocking agent comprising an inorganic or organic filler such as silica, talc, spherical cross-linkable polymethyl methacrylate, , A metal soap lubricant such as calcium stearate, a fatty acid amide lubricant widely used as a lubricant for films such as erucic acid amide, etc. (Patent Document 1, etc.), (b) powder such as nickel powder on the film surface It has been proposed that the body is attached, (c) the film surface is physically roughened by an embossing method or the like, and the contact area is reduced (Patent Document 2, etc.).
Japanese Patent No. 3207500 JP-A-10-95466

However, the above prior art has the following problems.
(A) When additives such as anti-blocking agents and lubricants are added, powders fall from the cross section when the film is cut, contaminating the product, or additives that bleed out on the surface are mixed into the contents There were hygiene problems such as (B) In the case of attaching powder such as victoria powder, the hygienic problem that the powder is mixed into the contents is unavoidable.
In particular, when an operation such as high-pressure steam sterilization is performed with the container and the packaging body in close contact, depending on the material of the container, the additive contained in the packaging body may penetrate the container wall and enter the contents. There was a risk of altering. (C) The technique of mechanically roughening the film surface has problems such as deterioration of the film appearance.

  The present invention has been made in view of such circumstances, and is superior in anti-tackiness and slipperiness, and has no fear of foreign matter mixing into the contents when a container or the like is constructed, and is also excellent in film appearance. An object of the present invention is to provide a means for realizing a film and an article such as a container using a polyethylene film having such characteristics.

  The present inventors have found that by combining specific ethylene-based polymers, anti-tackiness and slipperiness can be significantly improved without substantially adding additives such as lubricants and antiblocking agents. Completed the invention. The reason why the anti-adhesion property can be improved by the present invention is not necessarily clear, but by using a resin composition containing a specific ethylene polymer, a film having at least one surface uniformly roughened can be obtained. As a result, the contact area of the film is reduced, and it is presumed that the adhesion is reduced.

That is, the present invention relates to (1) a polyethylene film containing a plurality of types of ethylene polymers in which at least one of composition, density, and melt flow rate is different, wherein at least one of the plurality of types of ethylene polymers is The high-density polyethylene is characterized in that a dynamic friction coefficient between at least one surface is 0.40 or less and a surface having a dynamic friction coefficient of 0.40 or less is a rough surface having a single-side external haze value of 5% or more. A polyethylene film, (2) a polyethylene film according to (1), which is substantially free of a lubricant and an antiblocking agent, and (3) a maximum melt flow rate MFR _{MAX of the} all ethylene polymer. the ratio _MFR MAX _{/ MFR MIN} to the minimum value _{MFR MIN} of is characterized in that 5 to 200 (1) or 2) The polyethylene film according to (1) to (3), wherein the total amount of high-density polyethylene contained in 100 parts by mass of the total amount of ethylene polymer is 20 to 100 parts by mass. It is a polyethylene-type film in any one.
In addition, the definition of “melt flow rate”, “dynamic friction coefficient”, and “single-sided external haze value” in this specification and the measurement method thereof will be described later.

  Moreover, this invention is equipped with the polyethylene-type film in any one of (5) (1)-(4) as the said rough surface as the outermost surface, (6) Said polyethylene-type The laminate according to (5), comprising a film, comprising a sealant layer having the rough surface as a sealant surface, and further comprising at least one support layer for supporting the sealant layer, and (7) the polyethylene-based material The laminate according to (5) or (6), wherein at least one layer selected from a light shielding layer, a gas barrier layer, a printing layer, and a protective layer is provided inside the film.

  Moreover, this invention consists of the polyethylene-type film in any one of (8) (1)-(4), or the laminated body in any one of (5)-(7), The container characterized by the above-mentioned. (9) The polyethylene film according to any one of (1) to (4) or the laminate according to any one of (5) to (7), and the innermost surface of the polyethylene film. A package for packaging containers characterized by having a rough surface, (10) characterized in that the container is tightly accommodated in the packaging for containers and packaging described in (9) and further sterilized by high-pressure steam. (11) The container package according to (10), wherein the temperature of autoclaving is 121 ° C. or higher, and (12) the container is a medical container (10) or the container and packaging body according to (11), (13 At least the outermost layer of the container, the container packaging according to any of characterized by comprising the propylene polymer (10) to (12), a.

Further, the present invention relates to (14) an ethylene polymer composition comprising a plurality of types of ethylene polymers in which at least one of composition, density, and melt flow rate is different. A film obtained by molding at least one high-density polyethylene and a resin temperature of 180 to 260 ° C. has a coefficient of dynamic friction of at least one surface of 0.40 or less, and a surface having a coefficient of dynamic friction of 0.40 or less. Ethylene polymer composition characterized by having a rough surface with a single-side external haze value of 5% or more, (15) Ethylene according to (14), which is substantially free of lubricant and antiblocking agent (16) The ratio MFR _MAX / MF of the maximum value MFR _MAX of the melt flow rate of all ethylene polymers to the minimum value MFR _MIN R _MIN is characterized in that 5 to 200 (14) or ethylene-based polymer composition described in (15), the total amount of high density polyethylene contained in 100 parts by weight total of (17) ethylene polymer Is an ethylene-based polymer composition as described in any one of (14) to (16), wherein the content is 20 to 100 parts by mass.

In the present invention, a specific ethylene polymer is combined, so that additives such as a lubricant and an anti-blocking agent are not substantially added, and a physical treatment such as mechanically roughening the film surface is not performed. The anti-tackiness and slipperiness are remarkably improved.
Therefore, according to the present invention, ethylene has excellent anti-interbonding properties and slipperiness, and is excellent in safety and hygiene with no risk of foreign matter being mixed into the contents when a container or the like is constructed. A polymer composition, a polyethylene film, and a laminate can be provided. In addition, by using the polyethylene film or laminate of the present invention, the container is excellent in anti-tackiness and slipperiness, has no fear of foreign matter mixing into the contents, has excellent safety and hygiene, and has excellent appearance. A package for container packaging and a container package can be provided.
The polyethylene film of the present invention is made of an inexpensive polyolefin and has a low cost, and its industrial value is extremely high.

Hereinafter, the present invention will be described in detail.
"Ethylene polymer composition"
The ethylene-based polymer composition of the present invention includes a plurality of types of ethylene-based polymers in which at least one of the composition, density, and melt flow rate is different, and includes at least high-density polyethylene as the ethylene-based polymer. It is a thing.

  The ethylene-based polymer is not particularly limited as long as the main component is a polymer composed of ethylene. For example, an ethylene homopolymer and ethylene / α-olefin composed of ethylene and an α-olefin having 3 to 20 carbon atoms Examples thereof include ethylene-based polyolefins such as copolymers, and polar group-containing ethylene copolymers composed of ethylene and polar group-containing compounds copolymerizable therewith.

Specific examples of the ethylene-based polyolefin include high density polyethylene, linear low density polyethylene, and high pressure method low density polyethylene. Examples of the α-olefin used in the ethylene-based polyolefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene and the like. These can be used individually by 1 type or in combination of 2 or more types. Among these α-olefins, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like are particularly preferable because of excellent heat resistance.
Specific examples of the polar group-containing ethylene-based copolymer include a copolymer of ethylene and vinyl acetate, a copolymer of ethylene and (meth) acrylic acid and its metal salt, an alkyl ester of ethylene and (meth) acrylic acid, And a copolymer of ethylene and an alkyl ester of (meth) acrylic acid and an unsaturated dicarboxylic acid such as maleic anhydride.

  Among ethylene-based polymers, ethylene-based polyolefins are preferred because when they are processed into containers or the like, the content of foods, drugs, and the like has little shift in taste and smell. In the present invention, it is described that at least high-density polyethylene is used as the ethylene-based polymer. However, high-density polyethylene is excellent in heat resistance in addition to the general characteristics of the ethylene-based polyolefin. Among ethylene-based polyolefins, linear low-density polyethylene is also excellent in heat resistance, and it is also suitable to use this together.

  The ethylene-based polymer can be produced by a known production method such as a bulk method, a solution method, a slurry method, or a gas phase method. In the polymerization, a catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst can also be used. Also, radical initiators are often used for the production of low density polyethylene and the like by the high pressure method.

  The melt flow rate (hereinafter referred to as “MFR”) measured under conditions of a temperature of 190 ° C. and a load of 21.18 N in accordance with JIS K 7210 of the ethylene polymer to be used is 0.1 to 50 g / 10 min. Preferably there is. If the MFR is less than this range, the moldability tends to decrease, and if it exceeds this range, the strength and heat-fusibility tend to decrease.

The composition of this invention contains a high density polyethylene as a 1st ethylene polymer. Here, the “high density polyethylene” is a polyethylene having a density of 940 kg / m ³ or more measured according to JIS K 6922-2. The higher the density, the better the heat resistance and anti-interbonding properties. Especially because of excellent anti-mutual adhesion property during sterilization at 121 ° C. or higher, the density of the high density polyethylene is more preferably 945 kg / ^{m 3} or more, 950 kg / ^{m 3} or more is particularly preferable to use. The upper limit of the density of the high-density polyethylene is not particularly limited, but the upper limit of the density of the commercially available high-density polyethylene is about 966 kg / m ^3. . Moreover, since it is excellent in a moldability, heat resistance, and heat welding property, 0.1-40 g / 10min is preferable and, as for MFR of the high density polyethylene to be used, 0.2-20 g / 10min is more preferable.

The composition of the present invention further includes a second ethylene polymer that is different from the first ethylene polymer in at least one of composition, density, and MFR.
Although it does not specifically limit as a 2nd ethylene polymer, since there is little transfer of a taste and an odor to contents, such as a foodstuff and a medicine, when it is set as a container, ethylene polyolefin is preferable and it is excellent in heat resistance especially. Therefore, high-density polyethylene or linear low-density polyethylene is preferable. In particular, since it is excellent in heat resistance, it is preferable to use high density polyethylene as the second ethylene polymer. When the second ethylene polymer also includes high-density polyethylene, the density and / or MFR is configured to be different from that of the first ethylene polymer.
The MFR of the second ethylene polymer is not particularly limited, but is preferably 0.1 to 40 g / 10 minutes, and preferably 0.2 to 20 g / 10 minutes because of excellent moldability, heat resistance, and heat weldability. More preferred.

  In the ethylene-based polymer composition of the present invention, the total amount of high-density polyethylene contained in 100 parts by mass of the ethylene-based polymer is preferably 20 to 100 parts by mass, particularly 40 to 100 parts by mass. preferable. If the total amount of the high-density polyethylene is out of the range, fish eyes may be generated depending on molding conditions and the like, and the film appearance may be deteriorated. Furthermore, when the high-pressure method low-density polyethylene, linear low-density polyethylene, and ethylene-based copolymer are included, if the total amount thereof exceeds 80 parts by mass, the effect of improving heat resistance and anti-interbonding properties is remarkable. May not develop.

The ratio MFR _MAX / MFR _MIN to the minimum value MFR _MIN of the maximum MFR _MAX MFR _MAX of all ethylene polymers constituting the composition of the present invention is preferably 5 to 200, more preferably 10 to 150. It is preferably 10 to 100, particularly preferably. The present inventor has found that by setting MFR _MAX / MFR _MIN within such a range, the film surface can be stably roughened and good anti-interbonding properties can be obtained. The reason why good anti-tackiness is exhibited when the MFR ratio is within a specific range is not necessarily clear, but when the MFR ratio is within the above range, the ethylene polymer is within the range where film molding is possible. It is presumed that they are in a non-uniform mixed state and the film surface tends to be roughened.
In addition, when MFR _MAX / MFR _MIN is less than 5, the film surface is unlikely to be a rough surface, and the dynamic friction coefficient tends to increase. On the other hand, when MFR _MAX / MFR _MIN exceeds 200, the moldability is deteriorated, and the appearance of the film tends to be deteriorated such as generation of gel or fish eye, and it is difficult to form a good rough surface. .
Furthermore, since a good rough surface is easily formed, the amount of the ethylene polymer having the maximum MFR (MFR _MAX ) contained in 100 parts by mass of the ethylene polymer is 20 to 80 parts by mass. Is preferable, it is more preferable that it is 30-70 mass parts, and it is especially preferable that it is 40-60 mass parts.
Moreover, since the outstanding anti-interbonding property expresses, it is preferable to make the ethylene polymer which has the largest MFR (MFR _MAX ) into a high density polyethylene. In particular, the ethylene polymer having the largest MFR (MFR _MAX ) and the smallest MFR (MFR _MIN ) is composed of high-density polyethylene, and the composition contains almost no resin components other than these two types of high-density polyethylene. It is preferable to exhibit superior anti-intertwinability and heat resistance.

The composition of the present invention contains substantially no lubricant and antiblocking agent, and the coefficient of dynamic friction between at least one surface of a film obtained by molding at a resin temperature of 180 to 260 ° C. is 0.40 or less, preferably 0. .35 or less, particularly preferably 0.3 or less. In particular, it is preferable that the coefficient of dynamic friction between the surfaces not contacting the first roll at the time of molding is 0.40 or less. Here, the “first roll” means, for example, a first roll (cooling roll) that cools the molten resin extruded from the die in a flat film molding machine such as a T-die film molding machine. Moreover, in cylindrical film forming machines, such as an inflation film forming machine, the 1st roll used when crushing the cylindrical film which came out of die | dye is meant. That is, in the tubular film obtained by blown film molding or the like, the “surface not in contact with the first roll” corresponds to the inner surface of the tubular film.
If any of the surfaces has a coefficient of dynamic friction exceeding 0.40, the slipperiness is poor and the productivity when the film is processed into a bag or the like is lowered, which is not preferable.
The lower limit of the dynamic friction coefficient is not particularly limited, but is preferably about 0.1. If the coefficient of dynamic friction becomes too low, the film will slip too much when the film is rolled, and the roll end face will not be smooth, or the film fed from the roll will slip on the feed roll when processing laminate molding or bags, etc. There is a risk of adverse effects such as meandering.
In particular, the higher the density of the high-density polyethylene used, and the greater the amount of high-density polyethylene in the total amount of the composition, the lower the dynamic friction coefficient, which is preferable.
In this specification, “dynamic friction coefficient” means two polyethylene films, the same surface is overlapped, the sliding speed is 100 mm / min, the load is 200 g, the contact area is the area according to JIS K 7125. The square shape of 4000 mm ² and the sliding direction shall be measured as the M direction during film forming.

The composition of the present invention further contains substantially no lubricant and antiblocking agent, and has a single-sided external haze value of 5 on the surface having a dynamic friction coefficient of 0.40 or less obtained by molding at a resin temperature of 180 to 260 ° C. % Or more, preferably 8% or more. “Single-sided external haze value” means a haze value Hi (internal haze value) measured by uniformly applying liquid paraffin on both sides of the film and a haze value Hs (single-sided) measured by uniformly applying liquid paraffin only on one side. (Haze value) is a value calculated based on the following formula (1), and is a numerical value serving as an index of haze that correlates with the degree of roughening. In this specification, these internal haze values and single-sided haze values shall be measured in accordance with JIS K 7105.
Single-sided external haze value = Hs−Hi (1)
When a container or a packaging body for container packaging is configured using a polyethylene film obtained from the composition of the present invention or a laminate including the same, a surface having a single-sided external haze value of 5% or more is a sealant surface (that is, an inner surface). ) Is preferable. As a result, good anti-tackiness and openability are exhibited. When the single-sided external haze value on either side of the film is less than 5%, sufficient anti-tackiness and openability are not exhibited, which is not preferable.
In particular, the higher the density of the high-density polyethylene used, and the higher the amount of high-density polyethylene in the total composition, the higher the single-sided external haze value, which is preferable.
Note that the single-sided external haze value can be measured in the same manner for a laminate, but when an opaque layer such as an aluminum foil is provided, the measurement is performed with the layer removed.

The composition of the present invention contains the first and second ethylene polymers as essential components, and the first and second ethylene polymers are at least one of composition, density, and MFR. One or a plurality of other ethylene-based polymers having different values can be blended.
Furthermore, other polymers can be appropriately blended without departing from the object of the present invention. Examples of other polymers include, but are not limited to, propylenic polymers, various styrene elastomers such as ethylene / α-olefin elastomers and styrene / butadiene elastomers. However, since a heterogeneous mixed state sufficient to develop a good rough surface can be easily maintained, so that the polymer having the maximum MFR and the minimum MFR in all polymers is an ethylene polymer. It is preferred to select other polymers.

  In addition, in the range not significantly impairing the effects of the present invention, organic or inorganic fillers are blended for the purpose of improving strength, reducing volume, reducing calories during combustion disposal, and other commonly used known additives. For example, an antistatic agent, an antioxidant, an antifogging agent, an organic or inorganic pigment, an ultraviolet absorber, a dispersant, and the like can be appropriately blended as necessary. However, it is necessary that the lubricant and the antiblocking agent are not substantially contained.

Specific examples of the lubricant include metal soap lubricants such as calcium stearate and magnesium stearate, esters of higher fatty acids having 4 to 22 carbon atoms and linear aliphatic monohydric alcohols having 2 to 4 and 5 carbon atoms, Tributyl acetyl citrate, adipic acid-di-2-ethylhexyl, ethanediol montanic acid ester, poly (1,3-butanediol adipic acid) ester, methyl acetylricinoleate, poly (propylene glycol / adipic acid, lauric acid) ester , Fatty acid ester lubricants of monohydric and polyhydric alcohols such as poly (1,3-butylene glycol, 1,4-butylene glycol, octyl alcohol adipate) ester, bran and diisodecyl adipate, oleic acid amide, erucic acid Amide, behenic acid amide, ethyl Bis oleic acid amide, an acid amide-based lubricants such as hexamethylene bis oleic acid amide and ethylene bis-erucic acid amide and the like.
Specific examples of the anti-blocking agent include organic fine particles made of a crosslinked product such as polymethyl methacrylate, polystyrene, and polyamide, and inorganic fine particles such as silica, zeolite, diatomaceous earth, talc, kaolinite, and amorphous aluminosilicate.

Note that “substantially free of lubricant and antiblocking agent” means that it may be contained to the extent that it does not bleed on the polyethylene film surface. Specifically, the allowable content of the lubricant is less than 0.3% by mass in the composition, preferably less than 0.2% by mass, more preferably less than 0.1% by mass. The allowable content of the antiblocking agent is less than 0.05% by mass, preferably less than 0.03% by mass, more preferably less than 0.01% by mass in the composition.
Among the lubricants, metal soap-based lubricants have already been used in resin raw materials in order to pelletize the raw material resin well and neutralize and capture acidic compounds such as chlorine compounds used as catalysts during polymer production. Since it may be included, the minimum content may be unavoidable.
Therefore, it is preferable that at least acid amide type lubricants and fatty acid ester type lubricants widely used as film lubricants are not included. Furthermore, it is of course most preferable that no lubricant or antiblocking agent is contained since there is no fear of bleeding out.

  The preparation method of the composition of the present invention is not particularly limited, but each constituent component is mixed with a mixing machine such as a mixing roll, a Banbury mixer, a Henschel, a tumbler, a ribbon blender, etc., and at least one reaction of different ethylene polymers. Examples thereof include a method of continuously polymerizing in a vessel and pelletizing. Among these, the method of obtaining the composition by continuous polymerization is preferable from the economical viewpoint.

The composition of the present invention is configured as described above, and the present invention combines anti-tackiness and slipperiness without substantially adding a lubricant and an anti-blocking agent by combining specific ethylene polymers. This is a significant improvement.
Since the composition of the present invention has such properties, it is also suitable as a material for molded products such as hollow molding, injection molding, compression molding, and vacuum molding in addition to films. A molded product obtained by using the composition of the present invention has excellent release properties at the time of molding. In addition, containers such as bottles obtained by hollow molding and the like, and trays obtained by compression molding, vacuum molding, and the like have good removability when packaged in various packaging bodies.

"Polyethylene film"
The polyethylene film of the present invention is formed by molding the above-described ethylene polymer composition of the present invention into a film shape.
That is, in the polyethylene film containing a plurality of types of ethylene polymers in which at least one of composition, density, and melt flow rate is different, at least one of the plurality of types of ethylene polymers is a high density polyethylene, and at least One surface has a dynamic friction coefficient of 0.40 or less, and a surface having a dynamic friction coefficient of 0.40 or less is a rough surface having a single-side external haze value of 5% or more. Furthermore, it is preferable that substantially no lubricant and antiblocking agent are contained.
In addition, as mentioned above, when a container or a package for container packaging is configured using the polyethylene film of the present invention, the rough surface of the polyethylene film (the surface having a single-side external haze value of 5% or more) is the sealant surface. (That is, the inner surface) is preferable.

The polyethylene film of the present invention can be obtained by molding the composition of the present invention or pellets of the composition using an extruder or the like by various film molding methods. Examples of the film forming method include a water-cooled or air-cooled extrusion inflation method and a T-die method. In the present invention, an unstretched film as formed by a film molding machine such as a T-die molding machine or an inflation molding machine can be used as the polyethylene film of the present invention. In addition, although it may be subjected to a stretching treatment as necessary, when used as a sealant film, an unstretched film that has been molded by a film molding machine, that is, an unstretched film that is not subjected to a positive stretching process. It is preferable to use in a state.
Although the resin temperature at the time of manufacturing the polyethylene-type film of this invention is not specifically limited, 180-260 degreeC is preferable measured at the position immediately after discharged from the die exit at the time of film formation, 190-250 degreeC is more preferable, 200-250 degreeC is especially preferable. If the resin temperature exceeds 260 ° C., homogenization of mixing of ethylene polymers proceeds, and there is a risk that a rough surface is hardly formed on the film surface. Moreover, when it becomes less than 180 degreeC, mixing of ethylene polymers may become inadequate and there exists a possibility that an external appearance defect may generate | occur | produce.
Although the thickness of the film of this invention is not specifically limited, From an economical viewpoint and the viewpoint of the workability to a container etc., 5-1000 micrometers is preferable, 10-400 micrometers is more preferable, 30-200 micrometers is especially preferable.

Since the polyethylene-based film of the present invention is obtained using the above-described composition of the present invention, the semi-matt roll which does not substantially contain a lubricant and an antiblocking agent and mechanically roughens the film surface. Even if a physical treatment such as imparting irregularities to the film surface with a mat roll, a double mat roll, an embossing roll, or other specially processed roll is not performed, excellent anti-tackiness and slipperiness are exhibited. However, it goes without saying that such a physical treatment may be applied to the polyethylene film of the present invention.
Since the polyethylene film of the present invention exhibits excellent anti-interbonding properties and slipperiness, the films do not adhere to each other while being rolled and stored. Furthermore, when processing into a container, a packaging body for containers and the like, the film does not block and slides satisfactorily, so the productivity of containers and the like can be improved. In addition, since the film is difficult to be charged, it is difficult to enclose dust and foreign matter, and high quality containers and the like can be stably produced. By using the polyethylene film of the present invention, it is possible to provide a container, a packaging body for container packaging, and the like that are excellent in anti-adhesion property, and are excellent in filling the contents and taking out the container from the packaging body.

  In addition, since the polyethylene-based film of the present invention does not contain additives such as antiblocking agents and lubricants, there is no fear of contamination of the contents due to the additives when a container or the like is formed. In addition, since it is not necessary to perform physical treatment such as mechanically roughening the film surface, the film appearance is excellent. In addition, since the polyethylene film of the present invention has a fine uneven shape on the film surface, it can easily and satisfactorily attach printing ink, adhesive, etc. by the anchor effect, and has excellent printing characteristics and the like. It is.

"Laminate"
The polyethylene-based film of the present invention can be used as a single-layer sealant film or the like, but can also be used in the form of a laminate including this and other layers.
The laminate of the present invention is characterized in that the polyethylene film of the present invention has a rough surface (a surface having a single-side external haze value of 5% or more) as an outermost surface. In addition, as mentioned above, when a container or a package for container packaging is configured using the laminate of the present invention, the rough surface of the polyethylene film of the present invention is preferably used as a sealant surface (that is, an inner surface).

As an aspect of the laminate of the present invention suitable as a sealant film, for example, the polyethylene film of the present invention, a sealant layer having a rough surface as a sealant surface, and at least one support layer for supporting the same are coextruded. The thing of the structure laminated | stacked by the method etc. is mentioned.
Although it does not specifically limit as a support layer, It is preferable to use general polyolefins, such as an ethylene polymer and a propylene polymer, and since the interface adhesive strength of a sealant layer and a support layer is excellent, using an ethylene polymer. Is particularly preferred. Examples of the propylene polymer to be used include homopolypropylene, propylene / ethylene random copolymer, propylene / ethylene block copolymer and the like, and propylene / ethylene block copolymer is particularly preferable.
By using the components exemplified in the support layer, better transparency than that of a single-layer sealant film can be obtained.
Although the thickness of the whole laminated body is not specifically limited, When using as a sealant film, when sealing property is considered, 20-250 micrometers is preferable and 30-150 micrometers is especially preferable. The thickness ratio of the polyethylene film as the support layer and the sealant layer (support layer / sealant layer) is not particularly limited, but is preferably 50 to 95/50 to 5 in view of sealing properties.

As another aspect of the laminate of the present invention, there is a constitution in which at least one layer selected from a light shielding layer, a gas barrier layer, a printing layer, and a protective layer is provided inside the polyethylene film of the present invention. Can be mentioned.
Although it does not specifically limit as a structural component of a light shielding layer, a gas barrier layer, a printing layer, and a protective layer, For example, polyethylene, a polypropylene, ethylene-vinyl acetate copolymer saponified material, aluminum foil, biaxially stretched or unstretched polyamide, 2 Examples thereof include axially stretched or unstretched polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), aluminum oxide vapor deposited PET, and silica vapor deposited PET.
As another aspect of the laminate of the present invention, the light-shielding layer and the gas barrier are further provided for the previous laminate in which the polyethylene film of the present invention is used as a sealant layer and at least one support layer supporting the film is laminated. Examples include a laminate of at least one layer selected from a layer, a printing layer, and a protective layer.

  The method for preparing the laminate of the present invention is not particularly limited, but a plurality of layers are simultaneously laminated by melt molding such as a water-cooled or air-cooled (co) extrusion (multilayer) inflation method and a (co) extrusion (multilayer) T-die method. Forming a film or sheet of each layer as in a dry laminating method, and laminating them using an adhesive or the like if necessary, or one film or sheet in advance as in an extrusion laminating method. For example, a method of molding and laminating another layer thereon may be used. Among these, the dry lamination method and the extrusion lamination method are particularly preferable because various layers can be easily laminated.

Since the laminate of the present invention is provided with the rough surface of the polyethylene film of the present invention having a fine irregular shape as the outermost surface, it exhibits anti-adhesiveness like the polyethylene film of the present invention. Become.
In addition, when the polyethylene-type film of this invention is laminated | stacked on the single side | surface of a support layer, the laminated body with the high surface smoothness by the side of a support layer is obtained, exhibiting anti-tackiness.
On the other hand, when the polyethylene-based film of the present invention is used for both outer layers and any outermost surface is rough, in the slitting process or the like when processing the laminate of the present invention into a bag shape or the like, When the laminated body is unwound from the roll, the film surfaces in contact with each other slide on each other, and the effect of preventing mutual adhesion is remarkably exhibited. In addition, the laminate having such a configuration is useful because it is difficult to energize dust and foreign matter, and is superior in anti-adhesion property, and can smoothly transport a laminator or a slitter roll.
Since the laminate of the present invention has the rough surface of the polyethylene film of the present invention having a fine uneven shape as the outermost surface, it can easily and satisfactorily attach printing ink, adhesive, etc. due to the anchor effect, Excellent printing characteristics.

"container"
The container of the present invention comprises the above-described polyethylene-based film of the present invention or the laminate of the present invention.
Examples of the container of the present invention include a flexible bag or the like having the polyethylene film of the present invention as the innermost layer. In this embodiment, the rough surface of the polyethylene film of the present invention is preferably the innermost surface. Such a container is excellent in anti-tackiness between the inner surfaces of the containers and is easy to open, so there is no risk of opening failure when filling the contents.
Other embodiments of the container of the present invention include containers such as bags and trays having the polyethylene film of the present invention as the outermost layer. In this embodiment, the rough surface of the polyethylene film of the present invention is preferably the outermost surface. The bag-like container is obtained by welding the polyethylene film or laminate of the present invention with heat, high frequency, ultrasonic waves, or the like, and processing it into a bag shape or the like. In the container having the polyethylene film of the present invention as the outermost layer, mutual adhesion between the containers in the case of stacking and packaging or stacking and storing is suppressed. In addition, when the container is further externally packaged by vacuum contact packaging or the like, the takeout property is extremely excellent.
In particular, a container composed of the polyethylene film of the present invention alone or a container composed of the laminate of the present invention, and both the innermost layer and the outermost layer are composed of the polyethylene film of the present invention, have both of these effects. This is preferable. Furthermore, in the container in which both the innermost layer and the outermost layer are made of the polyethylene film of the present invention, it is preferable that the rough surface of the polyethylene film of the present invention be the innermost surface and the outermost surface.
In addition, since the container of the present invention is provided with the polyethylene film of the present invention or the laminate of the present invention, there is no possibility of foreign matter mixing into the contents, the film appearance is excellent, and further, printing It also has excellent characteristics.

"Packaging for containers and packaging"
The packaging body for container packaging according to the present invention comprises the polyethylene film of the present invention or the laminate of the present invention, and the innermost surface is a rough surface of the polyethylene film. .
The packaging body for container packaging of the present invention accommodates therein a container made of a synthetic resin or the like, particularly a container made of a flexible flexible material such as a film, and the polyethylene film or laminate of the present invention. It is obtained by welding with heat, high frequency, ultrasonic waves, etc., and processing into a bag shape or the like.
ADVANTAGE OF THE INVENTION According to this invention, the packaging body for container packaging which does not have a possibility of the mutual attachment of the inner surfaces of a packaging body or the mutual adhesion of the outer surface of the accommodated container and the inner surface of a packaging body is obtained. In addition, since the container packaging body of the present invention is provided with the polyethylene film of the present invention or the laminate of the present invention, there is no fear of foreign matter mixing into the contents, and excellent film appearance, Furthermore, the printing characteristics are also excellent.

"Container package"
The container package of the present invention is characterized in that the container is tightly accommodated in the container packaging package of the present invention and further sterilized by high-pressure steam.
Although there is no restriction | limiting in particular as a container used for the container package of this invention, From the viewpoint of a moldability and economical efficiency, the bag-like container which consists of a sheet | seat or film of a single layer or a multilayer structure which consists of a synthetic resin, etc. are mentioned. . As container materials, propylene-based polymers having high heat resistance, etc., in addition to conventionally used polyethylene, vinyl chloride, and the like have come to be used.
The high-pressure steam sterilization can be performed by a submerged method, a spray method, or the like that is usually used in the retort field, the medical field, or the like.
The high-pressure steam sterilization temperature is not particularly limited, but in recent years, from the viewpoint of improving productivity, maintaining the flavor of foods, improving sterilization, etc., the conventional high-temperature steam sterilization temperature tends to gradually increase. Recently, it has been implemented at a high temperature of 121 ° C. or higher. Furthermore, high-pressure steam sterilization is often performed by reducing the pressure inside the package so that the container and the package are brought into close contact with each other. In addition, the use of high-pressure steam sterilization has also been increasing in which tubes, connectors, and the like used when containers are used are stored together, and the inside of the package is depressurized so that the containers, packages and other stored items are brought into close contact with each other.

The container package of the present invention is excellent in heat resistance and extremely excellent in anti-tackiness after high-pressure steam sterilization at 121 ° C. or higher. In general, when a container is made of a flexible polyolefin resin sheet or film, it tends to adhere to the package, and the container package of the present invention does not adhere even in such a case. Absent. In particular, as described in the “Background Art” section, the package contact surface (outermost layer of the container) is made of a propylene polymer, particularly a propylene polymer or a propylene polymer containing an elastomer component. In a container, mutual attachment is likely to occur between the container and the package, which may hinder the removal of the container after the opening of the container package. Is very easy to remove. As described above, the anti-adhesion effect of the present invention is more clearly exhibited particularly in a container package in which the outermost layer of the container contains a container made of a propylene-based polymer.
Furthermore, in the container package of the present invention, mutual adhesion does not occur even under severe conditions in which the package is depressurized and the container and the package are in strong contact with each other under high pressure steam sterilization.

  The present invention can be preferably applied to a container package for storing medical containers and food containers. In particular, the present invention can be preferably applied to a container package in which medical containers such as a film bag, a blow bag, and a blow bottle are packed, which are filled with contents such as a high-calorie infusion and a peritoneal dialysis infusion (CAPD). In the present invention, since additives such as a lubricant and an anti-blocking agent are not substantially used, there is no possibility that they will bleed out and contaminate the contents of the container, which is extremely hygienic.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.
(Examples 1-7, Comparative Examples 1-8) <Composition>
The ethylene polymer and additives were blended in the compositions shown in Tables 1 and 2, and mixed with a Henschel mixer to obtain an ethylene polymer composition. Subsequently, it was molded at a resin temperature of 230 ° C. with a T-die molding machine equipped with a mirror roll as the first cooling roll, to obtain a polyethylene film having a thickness of 70 μm. In the table, the unit of the blending amount represents part by mass.
<Packaging body>
Two pieces of the obtained film cut into 35 cm × 35 cm squares are prepared, and the surfaces that are not in contact with the first cooling roll are overlapped with each other, and the three ends are heat-sealed to form a bag-like container packaging A package was obtained. The heat welding conditions were a seal width of 1 cm, a heat seal bar upper temperature of 180 ° C., a lower temperature of 60 ° C., a pressure of 0.2 MPa, and a treatment time of 1 second.
<Container>
Separately, in accordance with JIS K7210, a propylene / ethylene random copolymer having an MFR of 2 g / 10 minutes under a load of 230 ° C. and 21.18 N was molded at a temperature of 230 ° C. using a T-die molding machine, and the thickness was 200 μm. Film was obtained. The obtained film was cut into a 20 cm × 20 cm square, and two sheets were combined and heat-sealed at three end portions to prepare a bag-like container to be stored in the previous package. The heat welding conditions were a seal width of 1 cm, a heat seal bar upper temperature of 210 ° C., a lower temperature of 60 ° C., a pressure of 0.2 MPa, and a treatment time of 1 second.
This container was filled with 1 L of distilled water, and the unwelded ends were heat-sealed and sealed.
<Container package>
The container containing distilled water obtained above was accommodated in the previous package, and the opening of the package was heat-sealed while reducing the pressure in the package with a vacuum pump to obtain a container package. Further, this container / package was sterilized at 124 ° C. for 30 minutes using a spray-type high-pressure steam sterilizer.

The ethylene polymer, antiblocking agent and lubricant used are shown below. MFR is based on JIS K 7210, measured at a temperature of 190 ° C and a load of 21.18N, and the density is JIS
The density was measured with a density gradient tube according to K6922-2. The table also describes MFR _MAX / MFR _MIN .
(Ethylene polymer) HD1: MFR15g / 10 min, high density polyethylene HD2 density 965kg / ^{m 3:} MFR8g / 10 min, density polyethylene having a density of ^{955kg / m 3 HD3: MFR0.2g /} 10 min, density 960 kg / m ³ of high density polyethylene HD4: MFR0.6g / 10 min, density polyethylene having a density of ^{955kg / m 3 HD5: MFR5g /} 10 min, density polyethylene having a density of ^{955kg / m 3 HD6: MFR12g /} 10 min, density 955 kg / m ³ of high density polyethylene HD7: MFR0.08g / 10 min, density polyethylene having a density of ^{950kg / m 3 LL1: MFR0.5g /} 10 min, an ethylene-1 is a linear low density polyethylene having a density of 922 kg / ^{m 3} -Hexene copolymer LL2: MFR 15 g / 10 min, dense Linear low density polyethylene ethylene-1-hexene copolymer ^{935kg / m 3 LL3: MFR0.2g /} 10 min, an ethylene-1-butene copolymer is a linear low density polyethylene having a density of 935 kg / ^{m 3} Polymer LD1: High-pressure method low density polyethylene (additive) of MFR 50 g / 10 min, density 917 kg / m ³ C1: Silica-based antiblocking agent C2: Polymethyl methacrylate (PMMA) antiblocking agent C3: Erucic acid amide

(Evaluation items and evaluation method) <Dynamic friction coefficient>
According to JIS K 7125, the coefficient of dynamic friction of the polyethylene film is overlapped with the surfaces not contacting the first roll, the sliding speed is 100 mm / min, the load is 200 g, the contact area is a square shape with an area of 4000 mm ² , It was measured as the M direction during film formation.
<Single-sided external haze value>
The single-sided external haze value of the polyethylene film was measured according to JIS K 7105. That is, as the single-sided haze value (Hs), liquid paraffin was applied to the surface opposite to the dynamic friction coefficient measurement surface of the polyethylene film, and the haze value was measured. Next, as the internal haze value (Hi), liquid paraffin was applied to the other surface, and the haze value was measured. A single-sided external haze value was calculated from these values based on the above formula (1).
<Film appearance>
The container package (30 cm x 30 cm) after high-pressure steam sterilization is divided into nine 10 cm x 10 cm regions, the surface roughness is visually observed, and the number of compartments and the appearance of a uniform ground glass and good appearance The number of compartments whose surfaces were uniformly rough and the appearance was poor was counted and evaluated based on the following criteria.
○: 7 to 9 sections exhibiting a good appearance
(Triangle | delta): The number of divisions which exhibits a favorable external appearance is 4-6
X: The number of compartments exhibiting a good appearance is 0 to 3 <anti-tackiness>
The container package after high-pressure steam sterilization was cut and opened, and a container containing distilled water was taken out of the container package by hand. From the ease of taking out at that time, the mutual adhesion between the inner surfaces of the package and the mutual adhesion between the package and the container were evaluated based on the following criteria.
○: Opening of the container package is easy, and the container containing distilled water can be easily taken out without being caught on the package.
X: Opening of the container package is difficult, and even if it can be opened, the container containing distilled water is strongly attached to the package and difficult to take out.

(result)
The evaluation results in each example are shown in Table 1 and Table 2.
As shown in Table 1, in Examples 1 to 7 in which two types of high-density polyethylene, or high-density polyethylene and linear low-density polyethylene were blended, the obtained polyethylene film had a dynamic friction coefficient of 0.40. Hereinafter, in the case of a container package having a single-side external haze value of 5% or more and containing the container in a package using this, the package is depressurized even though it does not contain a lubricant or anti-blocking agent. However, even when subjected to a harsh treatment such as high-pressure steam sterilization at 121 ° C. or higher, the inner surfaces of the package and the package / container did not adhere to each other, and the container could be taken out very easily. Further, it has been clarified that the present invention exhibits such good anti-adhesion property even when a container made of a propylene-based copolymer, which tends to generate mutual adhesion, is used. Furthermore, the resulting package had good film appearance.

On the other hand, in Comparative Example 1 and Comparative Example 5 in which only one type of high-density polyethylene was blended as the ethylene polymer, the resulting polyethylene film had a large dynamic friction coefficient of more than 0.4 and poor slipperiness. The single-sided external haze value was also poor at less than 5.0%, and the package using this was extremely poor in anti-tackiness.
In Comparative Examples 2 to 4 in which only one type of high-density polyethylene was blended as an ethylene polymer and a lubricant or an antiblocking agent was added, the resulting dynamic friction coefficient of the polyethylene film was 0.4 or less and good slipperiness However, the package using this was still very poor in anti-tackiness. Furthermore, in Comparative Examples 2 and 3 in which the antiblocking agent was blended in a large amount of 0.5 parts by mass with respect to 100 parts by mass of the ethylene polymer, the film appearance of the resulting package was extremely poor.

In Comparative Example 6 in which only two types of linear low-density polyethylene were blended without blending high-density polyethylene as the ethylene-based polymer, the dynamic friction coefficient and single-sided external haze value of the obtained polyethylene film were good. However, the film appearance and anti-tackiness of the package using the same were remarkably poor.
Even in the case of blending two types of high-density polyethylene, in Comparative Example 7 in which MFR _MAX / MFR _MIN was less than 5, the resulting polyethylene film had a dynamic friction coefficient of more than 0.4 and a single-sided external haze value of 5.0. %, And the package using the same was extremely poor in anti-tackiness.
In Comparative Example 8 where high-density polyethylene and high-pressure low-density polyethylene were blended as the ethylene-based polymer, and MFR _MAX / MFR _MIN was more than 200, the dynamic friction coefficient of the obtained polyethylene-based film was more than 0.40, The package using this was remarkably poor in film appearance and anti-adhesion property.

  The ethylene-based polymer composition of the present invention, and the polyethylene-based film and laminate using the same are excellent in anti-tackiness and slipperiness, and there is no risk of foreign matter being mixed into the contents when a container is constructed. Because of its excellent film appearance, medical containers such as film bags, blow bags, blow bottles, and food containers filled with high-calorie infusions, peritoneal dialysis infusions (CAPD), etc. It can be preferably applied to a container package in which medical containers such as a film bag filled with contents such as high calorie infusion and peritoneal dialysis infusion (CAPD), a blow bag, and a blow bottle are packaged. In the present invention, since additives such as a lubricant and an anti-blocking agent are not substantially used, there is no possibility that they will bleed out and contaminate the contents of the container, which is extremely hygienic.

Claims (17)

In a polyethylene film containing a plurality of types of ethylene polymers, at least one of composition, density, and melt flow rate being different,
At least one of the plurality of types of ethylene polymers is high-density polyethylene, the dynamic friction coefficient between at least one surface is 0.40 or less, and the surface having a dynamic friction coefficient of 0.40 or less is a single-sided external haze value. A polyethylene film characterized by having a rough surface of 5% or more.   2. The polyethylene film according to claim 1, which is substantially free of a lubricant and an antiblocking agent. Polyethylene film according to claim 1 or 2 ratio _MFR MAX _{/ MFR MIN} to the minimum value _{MFR MIN} of the maximum value _{MFR MAX} melt flow rate of the entire ethylene polymer is characterized in that 5 to 200.     The polyethylene film according to any one of claims 1 to 3, wherein the total amount of the high-density polyethylene contained in 100 parts by mass of the ethylene polymer is 20 to 100 parts by mass.     A laminate comprising the polyethylene film according to any one of claims 1 to 4 having the rough surface as an outermost surface.     The laminate according to claim 5, comprising a sealant layer made of the polyethylene film and having the rough surface as a sealant surface, and further comprising at least one support layer for supporting the sealant layer.     The laminate according to claim 5 or 6, further comprising at least one layer selected from a light shielding layer, a gas barrier layer, a printing layer, and a protective layer inside the polyethylene film.     A container comprising the polyethylene film according to any one of claims 1 to 4 or the laminate according to any one of claims 5 to 7.     It consists of the polyethylene-type film in any one of Claims 1-4, or the laminated body in any one of Claims 5-7, and the innermost surface is made into the said rough surface of the said polyethylene-type film. Characteristic packaging for containers and packaging.     A container package, wherein the container is contained in close contact with the container packaging container according to claim 9 and further sterilized by high-pressure steam.     The container package according to claim 10, wherein the temperature of autoclaving is 121 ° C or higher.     The container package according to claim 10 or 11, wherein the container is a medical container.     The container package according to any one of claims 10 to 12, wherein at least an outermost layer of the container is made of a propylene-based polymer. In the ethylene-based polymer composition comprising a plurality of types of ethylene-based polymers in which at least one of the composition, density, and melt flow rate is different,
At least one of the plurality of types of ethylene polymers is high-density polyethylene, and the film obtained by molding at a resin temperature of 180 to 260 ° C. has a coefficient of dynamic friction between at least one surface of 0.40 or less, An ethylene polymer composition, wherein a surface having a dynamic friction coefficient of 0.40 or less becomes a rough surface having a single-side external haze value of 5% or more.   15. The ethylene-based polymer composition according to claim 14, which is substantially free of a lubricant and an antiblocking agent. Ethylene polymer composition according to claim 14 or 15 the ratio _MFR MAX _{/ MFR MIN} to the minimum value _{MFR MIN} of the maximum value _{MFR MAX} melt flow rate of the entire ethylene polymer is characterized in that 5 to 200 Stuff. The ethylene polymer composition according to any one of claims 14 to 16, wherein a total amount of the high-density polyethylene contained in 100 parts by mass of the ethylene polymer is 20 to 100 parts by mass.