JP2023080868A - Film, and production method of film - Google Patents

Abstract

To provide a film capable of forming a seal having a comparatively high peel strength by heat sealing, and capable of forming a seal excellent in stability of peel strength.SOLUTION: A film satisfies the following requirement (1), requirement (2), requirement (3), and requirement (4), and has a thickness of 10 μm or more and 300 μm or less. Requirement (1): When the total mass of the film is 100 mass%, 70 mass% or more and 95 mass% or less of polypropylene, and 5 mass% or more and 30 mass% or less of polyethylene are contained. Requirement (2): The ratio of a peak strength of the polyethylene to a peak strength of polypropylene of the film determined by an infrared ATR method is 0.3 or more and 0.55 or less. Requirement (3): The degree of orientation of the polypropylene calculated by an infrared dichroic ratio is 0 or higher and 0.17 or lower. Requirement (4): The quantity of heat of fusion required from 20°C to 130°C is 50 J/g or more and 70 J/g or less.SELECTED DRAWING: None

Description

The present invention relates to films and methods of manufacturing films.

BACKGROUND ART As packaging films used as materials for various packaging bags, packaging containers, etc., there are known packaging films comprising a base film and a sealant film laminated on the base film. Such packaging films are capable of forming a seal by heat-sealing the overlapping portions of the sealant film. Thereby, when the article is packaged using the packaging film, the accommodation space for the article can be closed by the seal.

As described above, when an article is packaged using a packaging film, it is required that the sealing property (that is, peel strength) of the seal be good, and the peelability of the packaging film at the seal be good. Sometimes. As a packaging film capable of forming a seal that satisfies such requirements, Patent Literature 1 discloses a packaging film provided with a sealant film containing predetermined amounts of polypropylene-based resin and polyethylene-based resin. In such a packaging film, the polyethylene resin contained in the sealant film has an ethylene structural unit of 95 mol% or more, the number of branches having 5 carbon atoms is less than 0.1 per 1000 carbon atoms, and the activation energy of flow is 40 kJ. / mol or more.

WO2011/162396

By the way, when heat-sealing to form a seal as described above, the temperature at which the packaging film is heated may vary due to the effects of the state of the heat-sealing device, the environmental temperature, and the like. If the heating temperature of the packaging film varies in this way, there is a risk that the peel strength of the packaging film in the seal will vary (in other words, the stability of the peel strength will decrease).

Therefore, the present invention has been made in view of such problems, and can form a seal with a relatively high peel strength by heat sealing, and also forms a seal with excellent peel strength stability. It is an object of the present invention to provide a film that can be used, and to provide a method for producing the film.

The film according to the present invention satisfies the following requirements (1), (2), (3), and (4), and has a thickness of 10 µm or more and 300 µm or less.

Requirement (1): The total mass of the film is 100% by mass, and contains 70% by mass or more and 95% by mass or less of polypropylene and 5% by mass or more and 30% by mass or less of polyethylene.
Requirement (2): The ratio of the peak intensity of polyethylene to the peak intensity of polypropylene of the film determined by the infrared ATR method is 0.3 or more and 0.55 or less.
Requirement (3): The degree of orientation of polypropylene calculated from the infrared dichroic ratio is 0 or more and 0.17 or less.
Requirement (4): The heat of fusion required from 20°C to 130°C is 50 J/g or more and 70 J/g or less.

The film manufacturing method according to the present invention is the film manufacturing method described above, and uses an air-cooling inflation film forming method.

ADVANTAGE OF THE INVENTION According to this invention, the film which can form the seal|sticker with a comparatively high peel strength by heat sealing, and can form the seal|sticker excellent in the stability of peel strength can be provided.

Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.

The film according to this embodiment satisfies the following requirements (1) to (4) and has a thickness of 10 μm or more and 300 μm or less. The thickness of the film is preferably 15 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less.

<Requirement (1)>
Taking the total mass of the film as 100% by mass, it contains 70% by mass or more and 95% by mass or less of polypropylene and 5% by mass or more and 30% by mass or less of polyethylene. As one aspect, the film preferably contains 80% by mass or more and 95% by mass or less of polypropylene and 5% by mass or more and 20% by mass or less of polyethylene, with the total mass of the film being 100% by mass.

<Requirement (2)>
The ratio of the peak intensity of polyethylene to the peak intensity of polypropylene of the film obtained by the infrared ATR method is 0.30 or more and 0.55 or less, preferably 0.35 or more and 0.54 or less, more preferably It is 0.40 or more and 0.53 or less. The ratio of the peak intensities of the above polyethylene can be obtained by the attenuated total reflection method (ATR method) using a Fourier transform infrared spectrophotometer, specifically by the method described in [Example] below. can ask. The above polyethylene peak intensity ratio can be changed by adjusting the content of polyethylene and the density of polyethylene to adjust the crystallinity.

<Requirement (3)>
The orientation degree of polypropylene calculated from the infrared dichroic ratio is 0 or more and 0.17 or less, preferably 0.05 or more and 0.17 or less, and more preferably 0.10 or more and 0.17 or less. The degree of orientation of polypropylene calculated from the infrared dichroic ratio can be obtained using a Fourier transform infrared spectrophotometer, and specifically, it can be obtained by the method described in [Examples] below. The degree of orientation of polypropylene calculated from the above infrared dichroic ratio can be changed by using polyethylene having a low melt flow rate (MFR) or polyethylene having long chain branches, which will be described later.

<Requirement (4)>
The heat of fusion of the film required from 20° C. to 130° C. is 50 J/g or more and 70 J/g or less, preferably 53 J/g or more and 67 J/g or less, more preferably 55 J/g or more and 64 J/g or less. is. The heat of fusion can be determined using a differential scanning calorimeter, and specifically, it can be determined by the method described in [Examples] below. The heat of fusion of the above film can be changed by appropriately selecting the polyethylene content, melting point, and density depending on the polypropylene.

The film according to the present embodiment is configured as described above, so that when heat-sealed, a seal portion having a relatively high peel strength can be formed, and the seal portion has excellent peel strength stability. can be formed.

<Polypropylene>
The polypropylene contained in the film is a propylene-based polymer containing more than 50% by mass of structural units derived from propylene, may be a propylene homopolymer, and contains more than 50% by mass of structural units derived from propylene. It may be a propylene-based copolymer. The propylene-based copolymer preferably contains 70% by mass or more and 98% by mass or less of structural units derived from propylene, more preferably 80% by mass or more and 98% by mass or less, and still more preferably 90% by mass or more and 98% by mass. Including: Further, the propylene-based copolymer preferably contains 2% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 20% by mass or less, still more preferably 2% by mass or more, of structural units derived from other than propylene. Contains 10% by mass or less. Examples of structural units other than propylene contained in the propylene-based copolymer include structural units derived from one or more selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms.

Propylene-based copolymers include, for example, propylene-based random copolymers. Examples of propylene-based random copolymers include random copolymers of propylene and ethylene (hereinafter also referred to as propylene-ethylene random copolymers), random copolymers of propylene and α-olefins (hereinafter referred to as propylene- α-olefin random copolymers), and terpolymers of propylene, ethylene and α-olefins (hereinafter also referred to as propylene-ethylene-α-olefin terpolymers).

The propylene-ethylene random copolymer preferably contains 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and still more preferably 0 5% by mass or more and 6% by mass or less, particularly preferably 2% by mass or more and 6% by mass or less.

The propylene-α-olefin random copolymer preferably contains 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, of structural units derived from α-olefin, More preferably, it contains 0.5% by mass or more and 6% by mass or less.

The propylene-ethylene-α-olefin terpolymer preferably contains 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, of structural units derived from ethylene. , more preferably 0.5% by mass or more and 5% by mass or less, and particularly preferably 0.5% by mass or more and 3% by mass or less. Further, the propylene-ethylene-α-olefin terpolymer preferably contains 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass, of structural units derived from α-olefins. % by mass or less, more preferably 1% by mass or more and 10% by mass or less, particularly preferably 3% by mass or more and 10% by mass or less.

Each of the above structural units can be obtained by infrared (IR) spectrometry according to the method described on page 616 of "Polymer Analysis Handbook" (published by Kinokuniya Shoten, 1995).

The propylene-based polymer may be a multi-stage propylene-based polymer obtained by polymerizing the components constituting the propylene-based polymer in two or more stages. The combination of components constituting the propylene-based multistage polymer may be propylene homopolymer components, a propylene homopolymer component and a propylene-based copolymer component, or a propylene-based copolymer. Ingredients may be the same. When at least two propylene-based polymer components are polymerized in multiple stages, the propylene-based multi-stage polymer is a propylene-based polymer composition containing at least two propylene-based polymer components.

The propylene-based multistage polymer consists of a polymer component (A) containing 95% by mass or more of propylene-derived structural units, and a propylene-derived structural unit, ethylene, and an α-olefin having 4 to 12 carbon atoms. It preferably contains a copolymer component (B) containing 50% by mass or more and 85% by mass or less of structural units derived from one or more selected from the group. Polymer component (A) is preferably a propylene homopolymer component, and copolymer component (B) is preferably a propylene copolymer component.

The propylene-based multistage polymer preferably contains the polymer component (A) in an amount of 50% by mass or more and 90% by mass or less based on the total content of the polymer component (A) and the copolymer component (B) of 100% by mass. more preferably 70% by mass or more and 85% by mass or less. Further, the propylene-based multistage polymer preferably contains 10% by mass or more of the copolymer component (B) with respect to 100% by mass of the total content of the polymer component (A) and the copolymer component (B). % by mass or less, more preferably 15% by mass or more and 30% by mass or less.

The polymer component (A) may contain other structural units derived from one or more selected from the group consisting of ethylene and 1-butene. Other structural units are preferably 5% by mass or less with respect to the polymer component (A).

The copolymer component (B) contains 10% by mass or more and 50% by mass or less of structural units derived from one or more selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms, preferably 15 mass % or more and 30 mass % or less are included. Structural units derived from one or more selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms are preferably structural units derived from ethylene.

Examples of α-olefins having 4 to 12 carbon atoms include 1-butene, 2-methyl-1-propene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene and 1-hexene. , 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene , 3,3-dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl-1-pentene, ethyl-1-hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1 -nonene, 1-decene, 1-undecene, 1-dodecene and the like. 1-butene, 1-pentene, 1-hexene, or 1-octene is preferred, and 1-butene or 1-hexene is more preferred from the viewpoint of copolymerization properties, economy, etc., More preferably, it is 1-butene. As the α-olefin having 4 to 20 carbon atoms, one of the above substances may be used alone, or two or more of the above substances may be used in combination.

Methods for producing a propylene-based polymer include, for example, a method of homopolymerizing propylene and a method of copolymerizing propylene with an olefin other than propylene in the presence of a Ziegler-Natta catalyst or metallocene catalyst. Ziegler-Natta type catalysts include, for example, catalysts in which a titanium-containing solid transition metal component and an organic metal component are combined. Examples of the Ziegler-Natta type catalyst include, for example, a Ti—Mg-based catalyst composed of a solid catalyst component having magnesium, titanium and halogen as essential components, a solid catalyst component having magnesium, titanium and halogen as essential components, an organoaluminum compound and , a catalyst in which a third component such as an electron-donating compound is combined as necessary. The metallocene catalyst includes, for example, a catalyst obtained by combining a transition metal compound of Groups 4 to 6 of the periodic table having at least one cyclopentadienyl skeleton and a cocatalyst component.

Examples of the polymerization method include a slurry polymerization method and a solution polymerization method performed in an inert hydrocarbon solvent, a liquid phase polymerization method performed in the absence of a solvent, a bulk polymerization method using a liquid monomer as a solvent, and a gaseous polymerization method. A vapor phase polymerization method in which a monomer is directly polymerized, or the like can be mentioned. Examples of inert hydrocarbon solvents used in slurry polymerization and solution polymerization include hexane, heptane, octane, decane, cyclohexane, methylcyclohexane, benzene, toluene, and xylene from which polymerization inhibitors have been removed. Polymerization by these polymerization methods may be performed in a patch system or in a continuous system. As a polymerization method for the propylene-based multistage polymer, it is preferable to employ a gas phase polymerization method. In the gas-phase polymerization method, a first step of polymerizing the polymer component (A) is performed, and then the copolymer component (B) is produced in the presence of the obtained polymer component (A). A second step of polymerizing is performed.

Methods for adjusting the molecular weights of the polymer component (A) and the copolymer component (B) include, for example, a method of adding an appropriate amount of a molecular weight modifier (e.g., hydrogen gas, metal compound, etc.) in each step, polymerization A method of adjusting the temperature, pressure, etc. of the time is mentioned. Methods for adjusting the content of ethylene-derived structural units in the polymer component (A) and the copolymer component (B) include a method of adding an appropriate amount of ethylene in each step of polymerization. The mass ratio of the polymer component (A) and the copolymer component (B) in the propylene-based multistage polymer is determined, for example, by the polymerization time during production of the propylene-based multistage polymer, the size of the polymerization tank, the weight in the polymerization tank, and the It can be controlled by the retention amount of coalescence, polymerization temperature, polymerization pressure, and the like.

In the production of a propylene-based multistage polymer, in order to remove residual solvents, ultra-low molecular weight oligomers, etc. produced by-products during production, for example, the propylene-based polymer is heated at a temperature below the melting temperature of the produced propylene-based polymer. Drying of the combination may be performed. The drying method is not particularly limited, and includes, for example, the methods described in JP-A-55-75410 and JP-A-2565753.

From the viewpoint of heat resistance, the melting point of the propylene-based polymer is preferably 120° C. or higher and 170° C. or lower, more preferably 130° C. or higher and 170° C. or lower.

The density of the propylene-based polymer is preferably 880 kg/m ³ or more and 910 kg/m ^{3 or less, more preferably 890 kg/m 3 or} more and 910 kg/m ³ or less.

The melt flow rate (hereinafter also referred to as "MFR") of the propylene-based polymer is not particularly limited, and may be, for example, 0.1 g/10 min or more and 200 g/10 min or less. /10 min or more and 50 g/10 min or less, 1 g/10 min or more and 10 g/10 min or less, or 1 g/10 min or more and 5 g/10 min or less. From the viewpoint of moldability, the MFR of the propylene-based polymer is preferably 0.5 g/10 minutes or more and 50 g/10 minutes or less. The MFR of a propylene-based polymer can be measured at a temperature of 230° C. and a load of 2.16 kg according to Method A specified in JIS K7210-1995.

Further, the molecular weight distribution of the propylene-based polymer is preferably 2 or more and 6 or less, more preferably 2 or more and 4 or less. Methods for adjusting the molecular weight distribution of the propylene-based polymer within the above range include, for example, a method of adjusting the catalyst species and catalyst amount, a method of adjusting the polymerization conditions, a method of using a decomposing agent such as a peroxide, and multi-stage polymerization. and a method of blending polymers of different molecular weights by blending two or more kinds of polymers. The molecular weight distribution is the ratio (Mw/Mn) of the weight average molecular weight (Mw) measured by gel permeation chromatography (hereinafter sometimes referred to as "GPC") to the number average molecular weight (Mn). Specifically, it can be obtained by the method described in [Example] below.

The stereoregularity of the propylene-based polymer may be isotactic, syndiotactic, or atactic. In the present invention, syndiotactic or isotactic are preferred from the viewpoint of heat resistance.

<Polyethylene>
The polyethylene contained in the above film is an ethylene polymer containing more than 50% by mass of structural units derived from ethylene, and may be an ethylene homopolymer containing more than 50% by mass of structural units derived from ethylene. It may be an ethylene-based copolymer. The ethylene-based copolymer preferably contains 80% by mass or more and 97% by mass or less, more preferably 85% by mass or more and 97% by mass or less, and still more preferably 90% by mass or more and 97% by mass or less of structural units derived from ethylene. . In addition, the ethylene copolymer preferably contains 3% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, and still more preferably 3% by mass or more and 10% by mass or less. % or less. Structural units other than ethylene contained in the ethylene-based copolymer include, for example, structural units derived from α-olefins. As the ethylene-based polymer, a copolymer of ethylene and α-olefin (hereinafter also referred to as “ethylene-α-olefin copolymer”) is preferable.

Ethylene homopolymers include, for example, high-pressure low-density polyethylene (LDPE) produced by high-pressure radical polymerization using a radical initiator, high-density polyethylene (HDPE) produced using a given catalyst, and the like. . High-pressure low-density polyethylene (LDPE) is a product in which repeating units of ethylene are randomly linked with a branched structure. The density of the high-pressure low-density polyethylene (LDPE) may be, for example, 910 kg/m ³ or more and 935 kg/m ³ or less. High density polyethylene (HDPE) is composed of repeating units of ethylene linked in a linear chain with substantially no branching. The density of high-density polyethylene (HDPE) may be, for example, 940 kg/m ³ or more and 970 kg/m ³ or less. The ethylene polymer is preferably high pressure low density polyethylene (LDPE).

The “ethylene-α-olefin copolymer” is a copolymer having ethylene-based structural units and α-olefin-based structural units. The ethylene-α-olefin copolymer has a total content of ethylene-based structural units and α-olefin-based structural units of 95% by mass or more with respect to 100% by mass of the total mass of the copolymer. is preferred. Further, "α-olefin" refers to a linear or branched olefin having a carbon-carbon unsaturated double bond at the α-position.

The structural unit based on α-olefin contained in the ethylene-α-olefin copolymer may be a structural unit based on α-olefin having 3 to 20 carbon atoms, and α-olefin having 4 to 20 carbon atoms. It may be a structural unit based on, a structural unit based on an α-olefin having 5 to 20 carbon atoms, or a structural unit based on an α-olefin having 6 to 20 carbon atoms.

Examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4 -methyl-1-pentene, 4-methyl-1-hexene and the like. Among these, the α-olefin having 3 to 20 carbon atoms is preferably 1-hexene, 4-methyl-1-pentene or 1-octene, more preferably 1-hexene or 1-octene. As the α-olefin having 3 to 20 carbon atoms, one of the above substances may be used alone, or two or more of the above substances may be used in combination.

The content of structural units based on ethylene is preferably 80% by mass or more and 97% by mass or less, more preferably 85% by mass or more and 97% by mass, with respect to 100% by mass of the total mass of the ethylene-α-olefin copolymer. % or less, more preferably 90% by mass or more and 97% by mass or less. In addition, the content of structural units based on α-olefin is preferably 3% by mass or more and 20% by mass or less, more preferably 3% by mass, with respect to 100% by mass of the total mass of the ethylene-α-olefin copolymer. % or more and 15 mass % or less, more preferably 3 mass % or more and 10 mass % or less.

The content of structural units based on ethylene is preferably 95 mol when the total of all monomer units constituting the ethylene-α-olefin copolymer is 100 mol% from the viewpoints of film stickiness suppression and heat resistance. % or more, more preferably 96 mol % or more, and still more preferably 97 mol % or more. In this case, the content of structural units based on α-olefins having 3 to 20 carbon atoms is preferably It is 5 mol % or less, more preferably 4 mol % or less, still more preferably 3 mol % or less.

In addition, from the viewpoint of film flexibility, the content of structural units based on ethylene is preferably 99 mol% when the total of all monomer units constituting the ethylene-α-olefin copolymer is 100 mol%. It is below. In this case, the content of structural units based on α-olefins having 3 to 20 carbon atoms is preferably 1 mol % or more.

Examples of ethylene-α-olefin copolymers include ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-1-hexene copolymers, and ethylene-4-methyl-1-pentene copolymers. , ethylene-1-octene copolymer, ethylene-1-butene-1-hexene copolymer, ethylene-1-butene-4-methyl-1-pentene copolymer, ethylene-1-butene-1-octene copolymer A polymer etc. are mentioned. Among these, the ethylene-α-olefin copolymer is preferably an ethylene-1-hexene copolymer, an ethylene-4-methyl-1-pentene copolymer, an ethylene-1-butene-1-hexene copolymer, polymer, ethylene-1-butene-4-methyl-1-pentene copolymer, ethylene-1-octene copolymer, ethylene-1-hexene-1-octene copolymer, or ethylene-1-butene- 1-octene copolymer, more preferably ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-1-butene-1-hexene copolymer, or ethylene-1- It is a butene-1-octene copolymer, more preferably an ethylene-1-hexene copolymer or an ethylene-1-butene-1-hexene copolymer.

The ethylene-α-olefin copolymer may have constitutional units based on monomers other than ethylene and α-olefins having 3 to 20 carbon atoms. Examples of monomers other than ethylene and α-olefins having 3 to 20 carbon atoms include conjugated dienes such as butadiene and isoprene, non-conjugated dienes such as 1,4-pentadiene, acrylic acid, methyl acrylate, and acrylic acid. acrylic acid esters such as ethyl, methacrylic acid, methacrylic acid esters such as methyl methacrylate or ethyl methacrylate, and vinyl acetate.

The ethylene-α-olefin copolymer preferably has long chain branches. That is, the polyethylene is an ethylene-α-olefin copolymer having a long chain branch from the viewpoint of forming a seal with relatively high peel strength and excellent stability of peel strength by heat sealing. is preferred. Long-chain branching refers to branched chains having 6 or more carbon atoms. In addition, the ethylene-α-olefin copolymer has a number of branches having 6 or more carbon atoms (hereinafter referred to as “N _LCB ”) as measured by ¹³ C-NMR from the viewpoint of improving heat seal peelability. is preferably 0.01 or more, more preferably 0.1 or more per 1000 carbon atoms. In addition, from the viewpoint of enhancing the sealing performance of heat sealing, N _LCB is preferably 1 or less, more preferably 0.7 or less per 1000 carbon atoms. In addition, the ethylene-α-olefin copolymer preferably has a branch number of 5 carbon atoms (hereinafter referred to as “N _c5 ”) measured by ¹³ C-NMR of 0.1 per 1000 carbon atoms. is less than, more preferably less than 0.05, more preferably less than 0.01, and most preferably zero.

N _LCB and N _c5 can be adjusted by selection of a production method such as gas phase polymerization or slurry polymerization, selection of a polymerization catalyst, polymerization temperature, polymerization pressure, type and amount of comonomer, and other polymerization conditions. For example, lowering the hydrogen concentration or ethylene pressure increases the _NLCB of the ethylene-α-olefin copolymer. Also, the _NLCB can be increased by pre-polymerizing.

N _LCB can be obtained by the following method. Specifically, from the ¹³ C-NMR spectrum using a cryoprobe at 600 MHz with an exponential window function, the sum of all peaks observed at 5 ppm to 50 ppm is 1000, and 38.09 ppm to 38.0 ppm. Let A be the peak area of a peak having a peak top near 27 ppm. This A is a value corresponding to the number of branched methine carbons having 4 or more carbon atoms. In order to separate the peaks of branched methine carbons having 5 or less carbon atoms and branched methine carbons having 6 or more carbon atoms, Gaussian was applied to the window function, and in the ¹³ C-NMR spectrum to which Gaussian was applied, 38.21 ppm ~ Let B be the peak observed at 38.27 ppm, and C be the peak observed at 38.21 ppm to 38.09 ppm. Then, N _LCB was obtained from the following formula (1).

N _LCB =A×B/(B+C) (1)

なお、前記炭素原子数５以上の分岐が結合したメチン炭素に由来するピークの位置は、測定装置および測定条件によりずれることがあるため、測定装置および測定条件毎に、標品の測定を行って決定することができる。また、スペクトル解析には、窓関数として、負の指数関数を用いることができる。 N _c5 can be obtained by the following method. Specifically, in the ¹³ C-NMR spectrum in which exponential is applied to the window function, the sum of all peaks observed at 5 ppm to 50 ppm is set to 1000, and the peak top is near 32.5 ppm to 32.7 ppm. The peak area of the peak having The peak area is a value corresponding to the number of branched methylene carbon atoms having 5 carbon atoms (C ^** in the following structural formula).

In addition, since the position of the peak derived from the methine carbon to which the branch having 5 or more carbon atoms is bonded may shift depending on the measurement device and measurement conditions, the sample should be measured for each measurement device and measurement condition. can decide. A negative exponential function can be used as a window function for spectrum analysis.

From the viewpoint of easy peelability, the ethylene polymer preferably has a flow activation energy (hereinafter also referred to as "Ea") of 40 kJ/mol or more, more preferably 50 kJ/mol or more, and further It is preferably 55 kJ/mol or more, particularly preferably 60 kJ/mol or more. From the viewpoint of sealing performance, Ea is preferably 100 kJ/mol or less, more preferably 90 kJ/mol or less. Ea can be adjusted, for example, by adjusting the hydrogen concentration or ethylene pressure during polymerization. When the hydrogen concentration or ethylene pressure is lowered, Ea increases.

Ea is a shift factor (a _T ) by the Arrhenius equation, which is obtained by the following method. That is, the melt complex viscosity-angular frequency curve of the ethylene polymer at temperatures (T, unit: ° C.) of 130 ° C., 150 ° C., 170 ° C. and 190 ° C. (unit of melt complex viscosity is Pa sec, angular frequency The unit is rad/sec.), based on the temperature-time superposition principle, the melting complex viscosity of the ethylene copolymer at 190 ° C. for each temperature (T) - angular frequency curve Obtain the shift factor (a T ) at each temperature ( _T ) obtained when superimposed on the viscosity-angular frequency curve, and obtain each temperature (T) and the shift factor (a T ) at each temperature ( _T ) , a linear approximation formula (formula (2) below) of [ln(a _T )] and [1/(T+273.16)] is calculated by the method of least squares. Next, Ea is obtained from the slope m of the linear expression and the following equation (3).

ln( _aT )=m{1/(T+273.16)}+n (2)
Ea=|0.008314×m| (3)

a _T : shift factor Ea: flow activation energy (unit: kJ/mol)
T: Temperature (unit: °C)

The above calculation can be performed using commercially available calculation software. 4.4.4 and the like.

The shift factor (a _T ) is obtained by moving the double-logarithmic curve of melt complex viscosity vs. angular frequency at each temperature (T) in the direction of log(Y)=−log(X) axis (however, Y axis is the melting complex viscosity, and the X axis is the angular frequency.) is the amount of movement when superimposed on the melting complex viscosity-angular frequency curve at 190 ° C. In the superposition, the melting at each temperature (T) The complex viscosity-angular frequency double-logarithmic curve shifts the angular frequency by a factor of a _T and the melt complex viscosity by a factor of 1/a _T for each curve. Further, the correlation coefficient when calculating the equation (2) from the four values of 130° C., 150° C., 170° C. and 190° C. by the method of least squares is 0.99 or more.

The melt complex viscosity-angular frequency curve is measured using a viscoelasticity measuring device (for example, Rheometrics Mechanical Spectrometer RMS-800 manufactured by Rheometrics), geometry: parallel plate, plate diameter: 25 mm, plate spacing: 1.5 mm or more. 2 mm, strain: 5%, angular frequency: 0.1 rad/sec to 100 rad/sec. In addition, the measurement is performed in a nitrogen atmosphere. In addition, an appropriate amount (for example, 1000 ppm) of an antioxidant is blended in advance in the measurement sample.

The density of the ethylene polymer is preferably 900 kg/m ³ or more and 950 kg/m ³ or less, and more preferably 910 kg/m ³ or more and 940 kg/m ³ from the viewpoint of stability of heat resistance, blocking resistance, and peel strength. or less, more preferably 920 kg/m ³ or more and 930 kg/m ³ or less.

Further, the density of the ethylene polymer is preferably 915 kg/m ³ or more, more preferably 918 kg/m ³ or more, and still more preferably 921 kg/m ³ or more, from the viewpoint of further improving the slipperiness of the film. and particularly preferably 924 kg/m ³ or more. In addition, the density of the ethylene polymer is preferably 950 kg/m 3 or less, more preferably 945 kg/m ³ or less, and still more preferably 940 kg/m ³ from the viewpoint of suppressing the occurrence of fish eyes in the film ^. or less, and particularly preferably 930 kg/m ³ or less. The density of the ethylene-based polymer may be 915 kg/m ³ or more and 950 kg/m ³ or less in one embodiment, and may be 918 kg/m ³ or more and 945 kg/m ³ or less in another embodiment, In still another aspect, it may be 921 kg/m ³ or more and 940 kg/m ³ or less, and in still another aspect, it may be 924 kg/m ³ or more and 930 kg/m ³ or less. The density of the ethylene-α-olefin copolymer can be adjusted by adjusting the α-olefin concentration during gas phase polymerization in the method for producing an ethylene-α-olefin copolymer described below. In addition, the density can be determined according to the A method (water replacement method) specified in JIS K7112-1980 after performing the annealing described in JIS K6760-1995. Specifically, the following [Example] It can be obtained by the method described in .

MFR of the ethylene polymer is preferably 0.01 g/10 min or more and 50 g/10 min or less. In addition, the MFR of the ethylene polymer is preferably 5 g/l0 min or less, more preferably 3 g/l0 min or less, from the viewpoint of improving the sealing performance of heat sealing.

In addition, the MFR of the ethylene polymer is preferably 0.0005 g/10 min or more, more preferably 0.001 g/10 min or more, from the viewpoint of reducing the extrusion load during film formation. In addition, the MFR of the ethylene-based polymer is preferably 0.1 g/10 min or less, more preferably 0.08 g/10 min or less, still more preferably 0, from the viewpoint of further improving the slipperiness of the film. .05 g/10 minutes or less. The MFR of the ethylene-based polymer may be 0.0005 g/10 min or more and 0.1 g/10 min or less in one embodiment, and 0.001 g/10 min or more and 0.08 g/10 min in another embodiment. minutes or less, and in still another embodiment, it may be 0.003 g/10 minutes or more and 0.05 g/10 minutes or less. In addition, in the measurement of the MFR of the ethylene-based polymer, a sample containing about 1000 ppm (preferably 1000 ppm) of antioxidant is used in the ethylene-based polymer. The MFR can be adjusted by adjusting the chain transfer agent concentration during gas phase polymerization in the method for producing an ethylene-based polymer, which will be described later. The MFR is a value measured under conditions of a temperature of 190° C. and a load of 2.16 kg according to Method A defined in JIS K7210-1995.

The melt flow rate ratio (hereinafter also referred to as MFRR) of the ethylene-based polymer is measured under the conditions of a temperature of 190 ° C. and a load of 21.60 kg with respect to the MFR measured under the conditions of a temperature of 190 ° C. and a load of 2.16 kg. is the ratio of MFR. MFRR is, for example, preferably 10 or more, more preferably 15 or more, and 17 or more, from the viewpoint of film forming processability, particularly from the viewpoint of reducing the extrusion load during film formation. is more preferable, and 20 or more is particularly preferable. In addition, the MFRR of the ethylene-based polymer is, for example, preferably 30 or less, more preferably 28 or less, and even more preferably 26 or less, from the viewpoint of film strength. The MFRR of the ethylene-based polymer may be from 10 to 30 in one embodiment, from 15 to 28 in another embodiment, and from 17 to 26 in another embodiment. In still another aspect, it may be 20 or more and 26 or less. When determining the MFRR of an ethylene polymer, a sample in which about 1000 ppm (preferably 1000 ppm) of an antioxidant is blended with the ethylene polymer is used in the measurement of each MFR.

The molecular weight distribution (Mw/Mn) of the ethylene-based polymer is preferably 3.0 or more, more preferably 4.0 or more, still more preferably 5.0 or more, and particularly preferably 6.0 or more. is. Moreover, from the viewpoint of the mechanical strength of the film, the molecular weight distribution (Mw/Mn) is preferably 9.0 or less, more preferably 8.5 or less. The molecular weight distribution (Mw/Mn) is the value obtained by dividing the weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatography, and dividing Mw by Mn ( Mw/Mn). The number average molecular weight (Mn) and weight average molecular weight (Mw) can be obtained by the method described in [Examples] below. The molecular weight distribution (Mw/Mn) can be adjusted, for example, by adjusting the hydrogen concentration or the polymerization temperature during polymerization, and increasing the hydrogen concentration or the polymerization temperature increases the molecular weight distribution (Mw/Mn).

The ethylene polymer preferably has g* defined by the following formula (4) of 0.70 or more and 0.95 or less.

g*=[η]/([η] _GPC × _gSCB *) (4)

(In the formula, [η] represents the intrinsic viscosity (unit: dl/g) of the ethylene-based polymer and is defined by the following formula (4-1).)
(Wherein, [η] _GPC is defined by the following formula (4-2).)
(Wherein, g _SCB * is defined by the following formula (4-3).)

[η]=23.3×log(ηrel) (4-1)
(In the formula, ηre1 represents the relative viscosity of the ethylene-based polymer.)

[η] _GPC = 0.00046 × Mv ^0.725 (4-2)
(In the formula, Mv represents the viscosity average molecular weight of the ethylene polymer.)

g _SCB *=(1−A) ^1.725 (4−3)
(In the formula, A measures the content of short chain branches in the ethylene-based polymer and is defined by the following formula (4-4).)

A={(12×n+2n+1)×y)}/{(1000-2y-2)×14+(y+2)×15+y×13} (4-4)
(Wherein, n represents the number of branched carbon atoms of the short chain branch (for example, n = 2 when butene is used as the α-olefin, n = 4 when hexene is used), y is NMR or infrared spectroscopy It represents the number of short chain branches per 1000 carbon atoms obtained from

For g*, the following literature was referred to. Developments in Polymer Characterization-4, . J. V. . Dawkins,. Ed. . Applied Science, London, . 1983, Chapter. I, . "Characterization. of. Long Chain Branching in Polymers," Th. G. by Scholte

[η] _GPC represents the intrinsic viscosity (unit: dl/g) of a polymer assuming that the molecular weight distribution is the same as that of the ethylene-based polymer and the molecular chain is linear.
g _SCB * represents the contribution to g* resulting from the introduction of short chain branching into the ethylene-based polymer.
Formula (4-2) is the H. Tung, Journal of Polymer Science, 36, 130 (1959) pp. 287-294 was used.

The relative viscosity (ηre1) of the ethylene polymer can be obtained by the following method. A sample solution was prepared by dissolving 100 mg of an ethylene-based polymer in 100 ml of tetralin containing 0.5% by mass of butylhydroxytoluene (BHT) as a heat deterioration inhibitor at 135° C., and the sample solution was measured using an Ubbelohde viscometer. and a blank solution composed of tetralin containing only 0.5% by mass of BHT as a heat deterioration inhibitor. The viscosity average molecular weight (Mv) of the ethylene polymer is defined by the following formula (4-5). In the formula, a=0.725.

g* is an index representing the degree of shrinkage of a molecule in a solution due to long-chain branching. become smaller. From the viewpoint of easy peelability, g* of the ethylene polymer is preferably 0.70 or more and 0.95 or less, more preferably 0.75 or more and 0.90 or less, and still more preferably 0.75 or more. 0.85 or less. When g* is 0.95 or less, long-chain branches are sufficiently contained, so that the peel strength of the heat-sealed seal is not too high, and the easy peelability is excellent. Further, when g* is 0.70 or more, the expansion of the molecular chains when forming a crystal is sufficient, so the probability of forming tie molecules is high, and the relaxation time of the molecular chains is short, so that heat sealing can be performed. Excellent sealing performance.

The intrinsic viscosity of the ethylene polymer (hereinafter referred to as [η]; the unit is dl/g) is preferably 1.0 dl/g or more from the viewpoint of further improving the slipperiness of the film, It is more preferably 1.2 dl/g or more, still more preferably 1.3 dl/g or more. [η] of the ethylene-based polymer is preferably 2.0 dl/g or less, more preferably 1.9 dl/g or less, and still more preferably, from the viewpoint of reducing film appearance defects such as fish eyes. is 1.7 dl/g or less. [η] of the ethylene polymer may be 1.0 dl/g or more and 2.0 dl/g or less in one aspect, and 1.2 dl/g or more and 1.9 dl/g or less in another aspect. , and in still another aspect, it may be 1.3 dl/g or more and 1.7 dl/g or less. [η] of the ethylene-based polymer can be measured using tetralin as a solvent and using an Ubbelohde viscometer at a temperature of 135° C. Specifically, it is determined by the method described in [Examples] below. be able to.

From the viewpoint of further improving the slipperiness of the film, the ethylene polymer preferably has a zero shear viscosity (hereinafter also referred to as η ⁰ ) at a temperature of 190° C. of 2×10 ⁵ Pa·sec or more, more preferably It is 3×10 ⁵ Pa·sec or more, more preferably 5×10 ⁵ Pa·sec or more. η ⁰ of the ethylene-based polymer is preferably 5×10 ⁶ Pa·sec or less, more preferably 3×10 ⁶ Pa·sec or less, from the viewpoint of reducing the extrusion load during film formation, More preferably, it is 1×10 ⁶ Pa·sec or less. η ⁰ of the ethylene-based polymer may be 2×10 ⁵ Pa·sec or more and 5×10 ⁶ Pa·sec or less in one embodiment, and 3×10 ⁵ Pa·sec or more and 3 in another embodiment. It may be x10 ⁶ Pa·sec or less, and in another embodiment, it may be 5 x 10 ⁵ Pa·sec or more and 1 x 10 ⁶ Pa·sec or less.

η ⁰ is the shear viscosity at a measurement temperature of 190° C. (η*; unit is Pa sec.)−angular frequency (ω, The unit is rad/sec.) It is a value calculated by fitting a curve.

η*=η ⁰ (1+(λω) ^a ) ^(n−1)/a (5)

λ: Time constant
a: width parameter
n: power law index (Power-Law index)

The shear viscosity is measured using a viscoelasticity measuring device (e.g., Rheometrics Mechanical Spectrometer RMS800 manufactured by Rheometrics), geometry: parallel plate, plate diameter: 25 mm, thickness of measurement sample: about 2.0 mm. , angular frequency: 0.1 rad/sec to 100 rad/sec, measurement points: 5 points per one digit of ω. The amount of strain is appropriately selected within the range of 3% to 10% so that the torque can be detected within the measurement range and the torque is not over. A measurement sample is prepared by pressing with a hot press at 150° C. for 5 minutes at a pressure of 2 MPa, cooling with a cooling press at 30° C. for 5 minutes, and press-molding to a thickness of 2 mm.

<Method for producing ethylene-α-olefin copolymer>
A method for producing an ethylene-α-olefin copolymer includes, for example, a method of copolymerizing ethylene and an α-olefin in the presence of an olefin polymerization catalyst. As the olefin polymerization catalyst, for example, a component (H) obtained by supporting an activating cocatalyst component (hereinafter also referred to as component (I)) on a fine particle carrier, a metallocene complex, and an electron donating compound. Those formed by contact, or those formed by contacting the component (H), the metallocene-based complex, and the organoaluminum compound are included. Specifically, as the olefin polymerization catalyst, a small amount of olefin is polymerized (hereinafter referred to as prepolymerization) in the presence of a catalyst component obtained by contacting the component (H), a metallocene complex, and an organoaluminum compound. .) preferably contains a prepolymerization catalyst component obtained by the above.

Component (I) includes zinc compounds and the like. Examples of zinc compounds include compounds obtained by contacting diethylzinc, fluorinated phenol, and water.

As the particulate carrier, a porous substance having a 50% volume average particle diameter of 10 μm to 500 μm can be used. The 50% volume average particle size is measured by a light scattering laser diffraction method. Examples of particulate carriers include inorganic substances and organic polymers. Examples of inorganic substances include _inorganic oxides such _{as SiO2} , _Al2O3 , MgO, _ZrO2 , TiO2, _B2O3 , CaO, _ZnO , BaO, _ThO2 , smectite, montmorillonite, hectorite, and laponite. , saponite and other clays and clay minerals. Examples of organic polymers include polyethylene, polypropylene, styrene-divinylbenzene copolymers, and the like. The fine particle carrier is preferably a fine particle carrier made of an inorganic substance. The pore volume of the particulate carrier is not particularly limited, and may be, for example, 0.3 ml/g or more and 10 ml/g or less. The specific surface area of the particulate carrier is not particularly limited, and may be, for example, 10 m ² /g or more and 1000 m ² /g or less. The pore volume and specific surface area can be determined by a gas adsorption method. The pore volume can be obtained by analyzing the amount of gas desorption by the BJH method, and the specific surface area can be obtained by analyzing the amount of gas adsorption by the BET method.

A metallocene complex is a transition metal compound having a ligand containing a cyclopentadiene type anion skeleton. As the metallocene complex, a transition metal compound represented by the following general formula or its μ-oxo type transition metal compound dimer is preferable.

L ² _a M ² X ¹ _b
(In the formula, M ² is a transition metal atom of Groups 3 to 11 of the periodic table or the lanthanide series. ^{L 2} is a group having a cyclopentadiene type anion skeleton, and multiple L ² are directly linked to each other. , or may be linked through a residue containing a carbon atom, a silicon atom, a nitrogen atom, an oxygen atom, a sulfur atom or a phosphorus atom, X ¹ is a halogen atom, a hydrocarbon group (provided that the cyclopentadiene type excluding groups having an anion skeleton), or a hydrocarbon oxy group, where a represents 2 and b represents 2.)

Examples of organoaluminum compounds include trimethylaluminum, triethylaluminum, tributylaluminum, triisobutylaluminum, and tri-normal octylaluminum, preferably triisobutylaluminum or tri-normal octylaluminum, more preferably It is triisobutylaluminum.

Examples of the electron donating compound include triethylamine, triisobutylamine, tri-normal octylamine and the like, preferably triethylamine.

Examples of the method for producing the ethylene-α-olefin copolymer include slurry polymerization and gas phase polymerization, preferably continuous gas phase polymerization. Examples of solvents used in the slurry polymerization method include inert hydrocarbon solvents such as propane, butane, isobutane, pentane, hexane, heptane and octane. The gas phase polymerization reactor used in the continuous gas phase polymerization method includes, for example, a device having a fluidized bed reactor, preferably a device having a fluidized bed reactor having an enlarged section. A stirring blade may be installed inside.

When the olefin polymerization catalyst contains a prepolymerization catalyst component, the method of supplying the olefin polymerization catalyst (prepolymerization catalyst component) to the continuous polymerization reactor for forming particles of the ethylene-α-olefin copolymer includes, for example, A method of supplying an olefin polymerization catalyst in a moisture-free state using an inert gas such as argon, nitrogen, hydrogen or ethylene, or a method of dissolving or diluting an olefin polymerization catalyst in a solvent and supplying it in a solution or slurry state. is mentioned.

The polymerization temperature for the gas phase polymerization of the ethylene-α-olefin copolymer is, for example, below the temperature at which the ethylene-α-olefin copolymer melts, preferably 0° C. or higher and 150° C. or lower, and more preferably. It is 30° C. or higher and 100° C. or lower, more preferably 70° C. or higher and 87° C. or lower. Hydrogen may be added to adjust the melt fluidity of the ethylene-α-olefin copolymer. Hydrogen is preferably controlled to be 0.01 mol % or more and 1.1 mol % or less with respect to 100 mol % of ethylene. The ratio of hydrogen to ethylene during gas phase polymerization can be controlled by the amount of hydrogen generated during polymerization and the amount of hydrogen added during polymerization. An inert gas may coexist in the mixed gas in the polymerization reactor. When the olefin polymerization catalyst contains a prepolymerization catalyst component, the olefin polymerization catalyst may contain a cocatalyst component such as an organoaluminum compound.

The film according to the present embodiment can be produced by melt-kneading the polypropylene and polyethylene to form a film. For example, the film according to the present embodiment can be produced using an inflation film forming method (air cooling method, water cooling method) using a blown film forming machine, a cast film forming method using a T-die, or the like. It is preferable to manufacture using a film-forming method. The film forming temperature in the air-cooled inflation film forming method is preferably 190° C. or higher and 230° C. or lower, and the blow ratio is preferably 1.2 or higher and 4.0 or lower. Moreover, the film according to the present embodiment may be subjected to stretching treatment such as uniaxial stretching treatment or biaxial stretching treatment.

The film according to this embodiment may contain a lubricant and/or an antiblocking agent. Furthermore, the film according to the present embodiment may contain additives such as antioxidants, neutralizers, weathering agents, antistatic agents, antifogging agents, anti-dripping agents, pigments, fillers, and the like.

The film according to this embodiment can be laminated with another sheet material to form a multilayer film. In the multilayer film, the film according to this embodiment is preferably located on the outermost surface. In this case, the film according to this embodiment can be used as a sealant layer of a multilayer film. That is, the film according to this embodiment can be used as a sealant film. Other sheet materials constituting the multilayer film include, for example, cellophane, paper, paperboard, fabric, aluminum foil, polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and polypropylene resins. Formed sheet materials are included.

A method for producing a multilayer film is not particularly limited, and an example thereof includes a lamination method in which the film according to the present embodiment and another sheet material are bonded together. Lamination methods include, for example, a dry lamination method, a wet lamination method, a sand lamination method, and the like.

A multilayer film comprising the film according to the present embodiment as a sealant layer is used for packaging foods, beverages, seasonings, milk, etc., dairy products, pharmaceuticals, electronic components such as semiconductor products, pet food, pet care products, detergents, toiletries, etc. It can be used as a packaging film (for example, a film forming a packaging pouch) used when packaging.

It should be noted that the film and the method for manufacturing the film according to the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. In addition, the configurations, methods, etc. of the embodiments other than the above may be arbitrarily adopted and combined, and the configurations, methods, etc. according to one embodiment described above may be applied to the configurations, methods, etc. according to the other embodiments described above. You may

EXAMPLES The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[Measuring method]
Numerical values for each item in Examples and Comparative Examples were determined according to the following methods.

<Elemental analysis>
Zn: After the sample was placed in an aqueous sulfuric acid solution (concentration 1M), ultrasonic waves were applied to extract the metal component. The resulting solution was quantified by ICP emission spectroscopy.
F: The sample was burned in a flask filled with oxygen, and the resulting combustion gas was absorbed in an aqueous sodium hydroxide solution (10%). The obtained aqueous solution was quantified by the ion electrode method.

<Melt flow rate of polyethylene (MFR, unit: g/10 minutes)>
It was measured under conditions of a temperature of 190° C. and a load of 2.16 kg according to the A method defined in JIS K7210-1995.

<Melt flow rate of polypropylene (MFR, unit: g/10 minutes)>
It was measured under conditions of a temperature of 230° C. and a load of 2.16 kg according to the A method defined in JIS K7210-1995.

<Density (unit: kg/m ³ )>
Density was measured according to the method specified in JIS K7112-1980, Method A (water substitution method). The samples were annealed according to JIS K6760-1995.

<Mw/Mn>
Calculate the weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene obtained by gel permeation chromatography (GPC) measurement, and divide Mw by Mn to obtain the molecular weight distribution (Mw/Mn). bottom.
・ GPC device: HLC-8121GPC/HT (manufactured by Tosoh Corporation)
・ GPC column: TSKgelGMH6-HT (manufactured by Tosoh Corporation) x 3 ・ Measurement temperature: 140 ° C.
Solvent and mobile phase: ortho-dichlorobenzene containing 0.05% by mass of dibutylhydroxytoluene (Wako special grade)
・Mobile phase flow rate: 1.0 ml/min ・Injection volume: 300 µl
・Detector: Differential refraction ・Molecular weight standard substance: Standard polystyrene ・Data acquisition interval: 2.5 seconds

<Intrinsic viscosity ([η], unit: dl/g)>
The polymer was dissolved in a tetralin solvent and measured at 135° C. using an Ubbelohde viscometer.

<Melt tension of propylene-based polymer (unit: mN)>
Using a melt tension measuring machine manufactured by Toyo Seiki Co., Ltd., the melt tension of the propylene-based polymer composition was measured under the following conditions.
A cylinder with an inner diameter of 9.55 mm was fitted with an orifice with a length of 8.00 mm and an inner diameter of 2.10 mm. After that, the cylinder was filled with the propylene-based polymer composition, a piston was inserted into the cylinder, and the cylinder was preheated at 190° C. for 5 minutes to sufficiently melt the propylene-based polymer composition. Thereafter, the piston is lowered at a speed of 5.7 mm/min, and the propylene-based polymer composition melted and extruded from the orifice at 0.32 g/min is taken up at 15.7 m/min. The tension (mN) acting on the film was measured with a tension detector and taken as the melt tension.

[Method for evaluating physical properties of film]
The physical properties of the films of Examples and Comparative Examples were evaluated according to the following methods.

<Ratio of polyethylene peak intensity (referred to as ATR (PE/PP)) to the polypropylene peak intensity of the film obtained by the infrared ATR method (unit:-)>
Using a Fourier transform infrared spectrophotometer, the ATR (PE/PP) of the film was measured by the attenuated total reflection method (ATR method). The measurement conditions were as follows.
・ Apparatus: Fourier transform infrared spectrophotometer FT/IR-6200 manufactured by JASCO Corporation
・ATR unit: MIRacle single reflection ATR made by PIKE
・Infrared incident angle: 45 degrees ・Prism: germanium ・Measurement area: 700 cm ^-1 to 4000 cm ^-1
ATR (PE/PP) was calculated from the following formula. The peak height at 730 cm ⁻¹ with 760 cm ⁻¹ as the baseline was calculated as the absorbance derived from polyethylene (ABS(PE)). The peak height at 997 cm ⁻¹ with 1030 cm ⁻¹ as the baseline was calculated as the absorbance derived from polypropylene (ABS(PP)).
ATR(PE/PP) = ABS(PE)/ABS(PP)

<Orientation degree of polypropylene calculated from infrared dichroic ratio (unit: -)>
Measured using a Fourier transform infrared spectrophotometer. The measurement conditions were as follows.
・ Apparatus: Fourier transform infrared spectrophotometer FT / IR-6200 manufactured by JASCO Corporation Measurement area: 800 cm ^-1 to 4000 cm ^-1
The degree of orientation (F) of polypropylene was calculated from the following formula from the infrared dichroic ratio (D). Let A∥ be the absorbance when the polarizing plate is parallel to the MD direction of the film, and A⊥ when it is perpendicular, and D is defined as A∥/A⊥. Absorbance was calculated using the peak height at 997 cm ⁻¹ with baselines of 950 cm ⁻¹ and 1030 cm ⁻¹ .
F = (D-1)/(D+2)

<The heat of fusion (ΔH) required up to 130°C (unit: J/g)>
It was measured using a differential scanning calorimeter. The measurement conditions were as follows.
・ Apparatus: DSC Q100 manufactured by TA Instruments
・Measurement start temperature: 0°C
・Measurement end temperature: 230°C
・Temperature increase rate: 5°C/min ・Sample mass: 5 mg
・A baseline was taken at 20°C and 200°C, and the heat of fusion from 20°C to 130°C was calculated.

<Heat seal strength HSS (unit: N/15mm)>
The sealing surfaces of the laminate films obtained in each example and each comparative example were overlapped and heat-sealed in the TD direction using a heat sealer (manufactured by Tester Sangyo Co., Ltd.) under the following sealing conditions.
・Upper seal bar set temperature: 180°C, 200°C
・Lower seal bar set temperature: 40°C
・Seal time: 1 second ・Seal pressure: 0.1 MPa
・Seal width: 10 mm

After the obtained sample was allowed to stand at 23° C. for 24 hours or more, a test piece having a width of 15 mm in the direction orthogonal to the seal width direction was cut out to obtain a test piece having a seal portion of 10 mm×15 mm. The heat seal strength per width of 15 mm was measured by peeling the seal portion of the cut test piece 180° at a speed of 200 mm/min using a tensile tester. The maximum heat seal strength obtained was adopted.

<Ethylene-α-olefin copolymer (1)>
Ethylene-α-olefin copolymer (1) was produced according to the following production example.

<Production Example 1>
Production of component (H) Component (H) was produced in the same manner as the preparation of component (A) in Examples 1 (1) and (2) described in JP-A-2009-79180. As a result of elemental analysis, Zn=11% by mass and F=6.4% by mass.

・Production of prepolymerization catalyst component After adding 4.15 ^m3 of butane to an autoclave equipped with a stirrer and having an internal volume of 9000 L that has been purged with nitrogen in advance, 6.0 mol of racemic-ethylenebis(1-indenyl)zirconium diphenoxide is added, The autoclave was heated to 50° C. and stirred for 2 hours. Next, 60.4 kg of component (H) produced was added to the autoclave. After that, the temperature of the autoclave was lowered to 30° C., and after the system was stabilized, 5 kg of ethylene and 5 L of hydrogen (normal temperature and normal pressure) were added to the autoclave. Prepolymerization was initiated by adding 35.1 L. Ethylene and hydrogen (normal temperature and pressure) were supplied to the autoclave at 60 kg/hr and 30 L/hr, respectively, for 30 minutes, then the temperature was raised to 50°C, and ethylene and hydrogen (normal temperature and pressure) were each supplied at 159 kg/hr. 0.54 m ³ /hr was fed into the autoclave. A total of 15.4 hours of prepolymerization was carried out. After completion of the prepolymerization, ethylene, butane, hydrogen, etc. were purged, and the remaining solid was vacuum-dried at room temperature to obtain a prepolymerization catalyst component containing 41.1 g of polyethylene per 1 g of component (H). [η] of the polyethylene was 1.21 dl/g. After that, the obtained prepolymerized catalyst component is placed in a high boulder manufactured by Toyo Hitec Co., Ltd. equipped with a mesh with an opening of 162 μm under a nitrogen atmosphere, and fine powder is removed to obtain a fine prepolymerized catalyst. A prepolymerized catalyst component from which components were removed was obtained.

・Production of ethylene-α-olefin copolymer 1-1 (LLDPE1-1) In the presence of the obtained prepolymerization catalyst component, ethylene, 1-butene and 1-hexene are mixed in a continuous fluidized bed gas phase polymerization apparatus. Copolymerization was carried out to obtain a powder of ethylene-1-butene-1-hexene copolymer (hereinafter referred to as LLDPE1-1). The polymerization conditions were as follows: polymerization temperature of 89° C.; polymerization pressure of 2 MPa; average ratio of hydrogen amount to 100 mol % of ethylene of 0.33%; The ratio was 1.33% and the molar ratio of 1-hexene was 0.53%. Ethylene, 1-butene, 1-hexene and hydrogen were fed continuously during the polymerization to keep the gas composition constant. In addition, the prepolymerization catalyst component and triisobutylaluminum (molar ratio of triisobutylaluminum to powder mass of LLDPE1-1: 0.44 mol/t), triethylamine (molar ratio of triisobutylaluminum: 10.2%), and oxygen ( 24% molar ratio to triisobutylaluminum) was fed continuously. The total powder mass in the fluidized bed was kept constant at 52.9 t. The average polymerization time was 6.6 hours. LLDPE1-1 powder was transferred to the hopper via a transfer pipe connecting the continuous fluidized bed gas phase polymerization apparatus and the hopper. A mixed gas obtained by mixing nitrogen at a flow rate of 250 m ³ /hr and water at a flow rate of 6 L/hr and heating to 65° C. was fed into the hopper, thereby bringing the LLDPE1-1 powder into contact with the water. The contact time with water in the hopper was 1.3 hours. The powder of LLDPE1-1 after contact with water was transferred to another hopper through a transfer pipe, and the powder of LLDPE1-1 was dried by circulating nitrogen through the hopper. The dried LLDPE1-1 powder is extruded using an extruder (LCM50 manufactured by Kobe Steel, Ltd.) at a feed rate of 50 kg/hr, a screw rotation speed of 450 rpm, a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature. Granulation was carried out at 200° C. to 230° C. to obtain pellets of LLDPE1-1. The physical properties of the obtained LLDPE1-1 pellets were evaluated. Table 1 shows the results.

<Production Example 2>
・Production of prepolymerization catalyst component After 41 L of butane was charged into an autoclave with an internal volume of 210 L and equipped with a stirrer, which had been purged with nitrogen in advance, 60.9 mmol of racemic-ethylenebis(1-indenyl)zirconium diphenoxide was charged, and the autoclave was 50%. The mixture was heated to °C and stirred for 2 hours. Next, 0.60 kg of the component (H) obtained in Production Example 1 above was added, and the temperature of the autoclave was lowered to 31°C. After the system was stabilized, 0.1 kg of ethylene and 0.1 L of hydrogen pressure volume) was added, and then 240 mmol of triisobutylaluminum was added to initiate polymerization. Ethylene and hydrogen were continuously supplied at 0.5 kg/Hr and 1.1 L (normal temperature and pressure volume)/Hr, respectively. Prepolymerization was carried out for a total of 10.0 hours by continuously feeding Hr and 8.2 L (volume at room temperature and pressure)/Hr. After completion of the polymerization, ethylene, butane, hydrogen, etc. were purged, and the remaining solid was vacuum-dried at room temperature to obtain a prepolymerization catalyst component containing 39.6 g of polyethylene per 1 g of component (H). [η] of the polyethylene was 1.17 dl/g.

・Production of ethylene-α-olefin copolymer 1-2 (LLDPE1-2) Copolymerization of ethylene, 1-butene and 1-hexene in a continuous fluidized bed gas phase polymerization apparatus in the presence of the above prepolymerization catalyst component was carried out to obtain a powder of ethylene-1-butene-1-hexene copolymer (hereinafter referred to as LLDPE1-2). As the polymerization conditions, the polymerization temperature is 89° C., the polymerization pressure is 2 MPa, the average amount of hydrogen per 100 mol % of ethylene is 0.21%, and the molar ratio of 1-butene to the total of ethylene, 1-butene and 1-hexene is 1.36% and the molar ratio of 1-hexene was 0.59%. During polymerization, ethylene, 1-butene, 1-hexene and hydrogen were continuously supplied to keep the gas composition constant. Further, the prepolymerization catalyst component, triisobutylaluminum, and triethylamine (molar ratio to triisobutylaluminum: 3%) were continuously fed to keep the total powder mass in the fluidized bed constant at 80 kg. The average polymerization time was 3.8 hours. LLDPE1-2 powder is extruded using an extruder (LCM50 manufactured by Kobe Steel, Ltd.) at a feed rate of 50 kg/hr, screw rotation speed of 450 rpm, gate opening of 50%, suction pressure of 0.1 MPa, resin temperature of 200 ° C. to 230. C. to obtain pellets of LLDPE1-2. The physical properties of the obtained LLDPE1-2 pellets were evaluated. Table 1 shows the results.

<Production Example 3>
・Production of prepolymerization catalyst component After adding 41 L of butane to an autoclave equipped with a stirrer and having an internal volume of 210 L, which was previously purged with nitrogen, 60.9 mmol of racemic-ethylenebis(1-indenyl)zirconium diphenoxide was added, and the autoclave was The mixture was heated to °C and stirred for 2 hours. Next, 0.60 kg of component (H) obtained in Production Example 1 above was added to the autoclave. After that, the temperature of the autoclave was lowered to 31° C., and after the system was stabilized, 0.1 kg of ethylene and 0.1 L of hydrogen (normal temperature and pressure) were added to the autoclave, and then 240 mmol of triisobutylaluminum was added to initiate prepolymerization. bottom. Ethylene and hydrogen (normal temperature and normal pressure) were supplied to the autoclave at 0.5 kg/hr and 1.1 L/hr, respectively, for 30 minutes. The autoclave was fed at 2.7 kg/hr and 8.2 L/hr. A total of 10.0 hours of prepolymerization was performed. After completion of the prepolymerization, ethylene, butane, hydrogen, etc. were purged, and the remaining solid was vacuum-dried at room temperature to obtain a prepolymerization catalyst component containing 39.6 g of polyethylene per 1 g of component (H). [η] of the polyethylene was 1.17 dl/g.

・Production of ethylene-α-olefin copolymer 1-3 (LLDPE1-3) Copolymerization of ethylene and 1-hexene was carried out in a continuous fluidized bed gas phase polymerization apparatus in the presence of the obtained prepolymerization catalyst component. to obtain a powder of ethylene-1-hexene copolymer (hereinafter referred to as LLDPE1-3). The polymerization conditions were as follows: polymerization temperature of 96° C., polymerization pressure of 2 MPa, average amount of hydrogen per 100 mol % of ethylene of 0.56%, and molar ratio of 1-hexene to the sum of ethylene and 1-hexene of 1.09%. and Ethylene, 1-hexene and hydrogen were continuously supplied during the polymerization to keep the gas composition constant. Further, the prepolymerization catalyst component, triisobutylaluminum, triethylamine (molar ratio to triisobutylaluminum: 30%), and oxygen (molar ratio to triisobutylaluminum: 12%) were continuously supplied. A total powder mass of 80 kg in the fluidized bed was kept constant. The average polymerization time was 3.4 hours. The obtained LLDPE1-3 powder was transferred to a hopper via a transfer pipe connecting the continuous fluidized bed gas phase polymerization apparatus and the hopper. The LLDPE1-3 powder was brought into contact with the LLDPE1-3 powder by charging methanol at room temperature into the hopper. The contact time with water in the hopper was 1 hour. The powder of LLDPE1-3 after contact with methanol was transferred to another hopper through a transfer pipe, and the powder of LLDPE1-3 was dried by circulating nitrogen through the hopper. The dried LLDPE1-3 powder is extruded using an extruder (LCM50 manufactured by Kobe Steel, Ltd.) at a feed rate of 50 kg/hr, a screw rotation speed of 450 rpm, a gate opening of 50%, a suction pressure of 0.1 MPa, and a resin temperature of 200 ° C. Pelletization was performed at ~230°C to obtain pellets of LLDPE1-3. The physical properties of the obtained LLDPE1-3 pellets were evaluated. Table 1 shows the results.

<Propylene polymer (PP-1)>
As the propylene-based polymer (PP-1), Noblen S131 (manufactured by Sumitomo Chemical Co., Ltd., melting point: 130° C., temperature: 230° C., melt flow rate: 1.5 g/10 minutes at a load of 2.16 kg) was used.

<High Melt Tension Propylene Polymer (HMS-PP)>
The following high melt strength propylene polymer (HMS-PP) was used.
Using a Ziegler-Natta type catalyst, a propylene homopolymer (HMS-PP-1) having an intrinsic viscosity of 7.18 dl/g is produced in the first step, and an intrinsic viscosity of 0.85 dl is produced in the second step. /g of propylene homopolymer (HMS-PP-2) was produced to obtain a propylene-based multistage polymer. The obtained propylene-based multistage polymer had a content of 19% by mass of the propylene homopolymer (HMS-PP-1) produced in the first step and a content of the propylene homopolymer (HMS-PP-1) produced in the second step. PP-2) content was 81% by mass. 0.050 parts by weight of calcium stearate, 0.2 parts by weight of Irganox 1010 (manufactured by BASF), and 0.025 parts by weight of Irgafos 168 (manufactured by BASF) were mixed with 100 parts by weight of this propylene-based multistage polymer. After that, the mixture was melt-kneaded to obtain a high-melt-strength propylene-based polymer (HMS-PP). The high melt tension propylene polymer (HMS-PP) had a melt flow rate of 8.9 g/10 minutes and a melt tension of 2.62 g at a temperature of 230° C. and a load of 2.16 kg.

<High density polyethylene (HDPE)>
As high-density polyethylene (HDPE), G2500 (manufactured by Keiyo Polyethylene Co., Ltd., melt flow rate of 5.0 g/10 minutes at 190° C. and load of 2.16 kg, density of 962.0 kg/m ³ ) was used.

<Ethylene-α-olefin copolymer (2)>
The following ethylene-α-olefin copolymer (2) was used.
・Ethylene-α-olefin copolymer 2-1 (LLDPE2-1): Metallocene-catalyzed linear low-density polyethylene Excellen FX FX307 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-1-hexene copolymer, MFR 3.1 g / 10 min, density 889.1 kg/m ³ , Mw/Mn 1.8)
Ethylene-α-olefin copolymer 2-2 (LLDPE2-2): metallocene-catalyzed linear low-density polyethylene Sumikasen E FV401 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-1-hexene copolymer, MFR 3.8g/10 min, density 904.0 kg/m ³ , Mw/Mn 2.0)
Ethylene-α-olefin copolymer 2-3 (LLDPE2-3): metallocene-catalyzed linear low-density polyethylene Excellen FX FX402 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-1-hexene copolymer, MFR 8.0 g / 10 min, density 880.0 kg/m ³ , Mw/Mn 1.9)

<Example 1>
[Inflation film molding]
PP-1 and LLDPE1-1 were mixed with the composition shown in Table 2 using a tumble mixer. Next, the resulting mixture is processed using an inflation film molding machine manufactured by Placo Co., Ltd. (Placo Co., Ltd. EXU single screw extruder, die (die diameter 125 mmφ, lip gap 2.0 mm), single slit air ring with iris), A blown film having a thickness of 50 μm was molded under processing conditions of a processing temperature of 190° C., an extrusion rate of 10 kg/hr, and a blow ratio of 1.5. Table 2 shows the physical properties (ATR (PE/PP), degree of PP orientation, thermal melting amount (ΔH)) of the obtained blown film.

[Laminated film molding]
Using a coater manufactured by Yasui Seiki Co., Ltd., an aliphatic ester coating agent (main agent = Mitsui Takeda Chemicals Co., Ltd. "Takelac A-310", curing agent = Mitsui Takeda Chemicals Co., Ltd. "Takenate A-3", acetic acid Ethyl was mixed in a mass ratio of 12:1:32, respectively) was applied to a polyester film (manufactured by Toyobo Co., Ltd., trade name “E5102”, thickness 12 μm, width 250 mm), and the inflation film After being pressure-bonded to the corona-treated surface of , it was heated in an oven at 40°C for 48 hours to obtain a laminate film. Table 2 shows the physical properties (heat seal strength (HSS)) of the obtained laminate film.

<Example 2>
[Inflation film molding]
PP-1 and LLDPE1-2 were mixed with the composition shown in Table 2 using a tumble mixer. Next, the resulting mixture is processed using an inflation film molding machine manufactured by Placo Co., Ltd. (Placo Co., Ltd. EXU single screw extruder, die (die diameter 125 mmφ, lip gap 2.0 mm), single slit air ring with iris), A blown film having a thickness of 50 μm was molded under processing conditions of a processing temperature of 210° C., an extrusion rate of 10 kg/hr, and a blow ratio of 1.5. Table 2 shows the physical properties (ATR (PE/PP), degree of PP orientation, thermal melting amount (ΔH)) of the obtained blown film.

[Laminated film molding]
Using a coater manufactured by Yasui Seiki Co., Ltd., an aliphatic ester coating agent (main agent = Mitsui Takeda Chemicals Co., Ltd. "Takelac A-310", curing agent = Mitsui Takeda Chemicals Co., Ltd. "Takenate A-3", acetic acid A biaxially oriented nylon film (manufactured by Unitika Ltd., trade name “Emblem (registered trademark) ON-15”, thickness 15 μm, and ethyl mixed in a mass ratio of 12:1:32, respectively) was applied. 250 mm in width), pressed against the corona-treated surface of the inflation film, and then heated in an oven at 40° C. for 48 hours to obtain a laminate film. Table 2 shows the physical properties (heat seal strength (HSS)) of the obtained laminate film.

<Example 3>
A blown film and a laminate film were obtained in the same manner as in Example 2, except that PP-1 and LLDPE1-3 were mixed at the formulation shown in Table 2 using a tumble mixer. Table 2 shows the physical properties of the obtained blown film and laminated film.

<Example 4>
A blown film and a laminate film were obtained in the same manner as in Example 2, except that PP-1 and LLDPE1-1 were mixed at the formulation shown in Table 2 using a tumble mixer. Table 2 shows the physical properties of the obtained blown film and laminated film.

<Comparative Example 1>
A blown film and a laminate film were obtained in the same manner as in Example 1 using PP-1. Table 2 shows the physical properties of the obtained blown film and laminated film.

<Comparative Example 2>
A blown film and a laminate film were obtained in the same manner as in Example 1, except that PP-1 and HMS-PP were mixed at the formulation shown in Table 2 using a tumble mixer. Table 2 shows the physical properties of the obtained blown film and laminate film.

<Comparative Example 3>
A blown film and a laminate film were obtained in the same manner as in Example 2, except that PP-1 and HDPE were mixed at the formulation shown in Table 2 using a tumble mixer. Table 2 shows the physical properties of the obtained blown film and laminated film.

<Comparative Example 4>
A blown film and a laminate film were obtained in the same manner as in Example 2, except that PP-1 and LLDPE2-1 were mixed at the formulation shown in Table 2 using a tumble mixer. Table 2 shows the physical properties of the obtained blown film and laminate film.

<Comparative Example 5>
A blown film and a laminate film were obtained in the same manner as in Example 2, except that PP-1 and LLDPE2-1 were mixed at the formulation shown in Table 2 using a tumble mixer. Table 2 shows the physical properties of the obtained blown film and laminated film.

<Comparative Example 6>
A blown film and a laminate film were obtained in the same manner as in Example 2, except that PP-1 and LLDPE2-2 were mixed at the composition shown in Table 2 using a tumble mixer. Table 2 shows the physical properties of the obtained blown film and laminated film.

<Comparative Example 7>
A blown film and a laminate film were obtained in the same manner as in Example 2, except that PP-1 and LLDPE2-3 were mixed at the formulation shown in Table 2 using a tumble mixer. Table 2 shows the physical properties of the obtained blown film and laminate film.

<Summary>
From the results in Table 2 above, it can be seen that the films of each example have a higher HSS than each comparative example and a smaller "HSS (2) (200°C) - HSS (1) (180°C)". . That is, by satisfying the requirements (1) to (4) like the film according to the present invention, it is possible to form a seal portion with a relatively high peel strength by heat sealing, and the stability of the peel strength An excellent seal can be formed.

Claims (5)

Satisfies the following requirements (1), (2), (3) and (4),
The thickness is 10 μm or more and 300 μm or less,
the film.

Requirement (1): The total mass of the film is 100% by mass, and contains 70% by mass or more and 95% by mass or less of polypropylene and 5% by mass or more and 30% by mass or less of polyethylene.
Requirement (2): The ratio of the peak intensity of polyethylene to the peak intensity of polypropylene of the film determined by the infrared ATR method is 0.3 or more and 0.55 or less.
Requirement (3): The degree of orientation of polypropylene calculated from the infrared dichroic ratio is 0 or more and 0.17 or less.
Requirement (4): The heat of fusion required from 20°C to 130°C is 50 J/g or more and 70 J/g or less.
A film according to claim 1,
80% by mass or more and 95% by mass or less of polypropylene and 5% by mass or more and 20% by mass or less of polyethylene,
the film. A film according to claim 1 or 2,
The polyethylene is an ethylene-α-olefin copolymer having long chain branches,
the film. The film according to any one of claims 1 to 3,
Manufactured using an air-cooled inflation film-forming method,
the film. A method for producing the film according to any one of claims 1 to 3,
Using the air-cooled inflation film-forming method,
Film production method.