WO2023132306A1

WO2023132306A1 - Non-oriented film, sealant film, and multilayered sealant film

Info

Publication number: WO2023132306A1
Application number: PCT/JP2022/048281
Authority: WO
Inventors: 知也村上; 篤太郎木村; 博貴志水; 淳尾留川; 友章水川; 凪 ▲高▼井
Original assignee: 株式会社プライムポリマー
Priority date: 2022-01-06
Filing date: 2022-12-27
Publication date: 2023-07-13
Also published as: KR20240090923A; JPWO2023132306A1

Abstract

[Problem] To provide: a cast polypropylene film that has an excellent balance of stiffness and low-temperature heat sealability; or a cast polypropylene film that has excellent stiffness and can be heat-sealed at a low temperature. [Solution] A non-oriented film comprising a propylene polymer composition that includes a prescribed ratio of a prescribed propylene polymer (A) and a propylene/α-olefin copolymer (B) that has an MFR of 0.1-30 g/10 min and a limiting viscosity [η] of greater than 1.5 dl/g to 5.0 dl/g as measured in a tetralin solvent at 135°C and contains a prescribed quantity of a structural unit derived from an α-olefin (excluding propylene).

Description

Unstretched films, sealant films and multi-layer sealant films

The present invention relates to non-stretched films, sealant films and multilayer sealant films.

Propylene-based polymers are widely used as materials for various molded articles (see, for example, Patent Documents 1 to 4), and the required properties differ depending on the molding method and application. For example, films made of propylene-based polymers are widely used as packaging films for foods and miscellaneous goods, taking advantage of their excellent mechanical properties such as rigidity and optical properties such as gloss. Unstretched polypropylene films (see, for example, Patent Documents 5 to 7) are known to have an excellent balance of rigidity and heat resistance. Further, Patent Document 8 discloses an unstretched polypropylene film using a specific propylene-based polymer and having particularly excellent rigidity.

WO 1999/007752 WO2005/097842 Japanese Patent Application Laid-Open No. 2001-302858 JP 2006-045446 A Japanese Patent Application Laid-Open No. 2002-265712 JP 2005-320359 A JP 2011-236357 A WO2021/025142

However, when the unstretched polypropylene film described in Patent Document 8 was used as a sealant film, the sealing performance was low (sealing temperature was high).

Therefore, the object of the first aspect of the present invention is to provide an unstretched polypropylene film that is excellent in well-balanced rigidity and low-temperature heat-sealing performance (hereinafter referred to as "first object").

A second aspect of the present invention is to provide a non-stretched polypropylene film having excellent rigidity and capable of being heat-sealed at a low temperature (hereinafter referred to as a "second problem"). ).

As a result of extensive studies, the present inventors have found that an unstretched film made of the propylene-based polymer composition described below can solve the first problem, and completed the first aspect of the present invention. rice field. A first aspect of the present invention relates to, for example, the following [1].

[1]
20 to 50% by mass of the propylene-based polymer (a1) having an intrinsic viscosity [η] in the range of 10 to 12 dl/g measured in a tetralin solvent at 135°C, and 135°C in a tetralin solvent 50 to 80% by mass of the propylene-based polymer (a2) having an intrinsic viscosity [η] in the range of 0.5 to 1.5 dl/g [however, the propylene-based polymer (a1) and the propylene-based polymer (a2) and the total amount of 100% by mass. ] A propylene-based polymer (A) containing
Melt flow rate (230 ° C., 2.16 kg load) is 0.1 to 30 g / 10 minutes, and intrinsic viscosity [η] measured in tetralin solvent at 135 ° C. exceeds 1.5 dl / g and 5.0 dl / g or less, and a propylene/α-olefin copolymer (B1) containing 5.5 mol% or more of structural units derived from an α-olefin (excluding propylene),
The content of the propylene-based polymer (A) is 1 to 10 parts by mass with respect to a total of 100 parts by mass of the propylene-based polymer (A) and the propylene/α-olefin copolymer (B1), An unstretched film comprising a propylene-based polymer composition (X1) containing 90 to 99 parts by mass of the propylene/α-olefin copolymer (B1).

Furthermore, as a result of extensive studies, the present inventors found that an unstretched film made of the propylene-based polymer composition described below can solve the second problem, and completed the second aspect of the present invention. let me A second aspect of the present invention relates to, for example, the following [2].

[2]
20 to 50% by mass of the propylene-based polymer (a1) having an intrinsic viscosity [η] in the range of 10 to 12 dl/g measured in a tetralin solvent at 135°C, and 135°C in a tetralin solvent 50 to 80% by mass of the propylene-based polymer (a2) having an intrinsic viscosity [η] in the range of 0.5 to 1.5 dl/g [however, the propylene-based polymer (a1) and the propylene-based polymer (a2) and the total amount of 100% by mass. ] A propylene-based polymer (A) containing
Melt flow rate (230 ° C., 2.16 kg load) is 0.1 to 30 g / 10 minutes, and intrinsic viscosity [η] measured in tetralin solvent at 135 ° C. exceeds 1.5 dl / g and 5.0 dl /g or less, and a propylene/α-olefin copolymer (B2) containing 1 mol% or more and less than 5.5 mol% of structural units derived from an α-olefin (excluding propylene). ,
The content of the propylene-based polymer (A) is 1 to 18 parts by mass with respect to a total of 100 parts by mass of the propylene-based polymer (A) and the propylene/α-olefin copolymer (B2), An unstretched film comprising a propylene-based polymer composition (X2) containing 82 to 99 parts by mass of the propylene/α-olefin copolymer (B2).

The first and second aspects of the present invention further relate to [3] to [6] below.

[3]
The unstretched film of [1] or [2], wherein the propylene-based polymer (A) has a melt flow rate (MFR) of 0.01 to 5 g/10 minutes measured under a load of 2.16 kg at 230°C. .

[4]
In the propylene-based polymer (A), the area ratio of the high molecular weight region having a molecular weight of 1,500,000 or more in the total area of the region surrounded by the molecular weight distribution curve measured by gel permeation chromatography (GPC) is 7% or more. The unstretched film according to any one of [1] to [3] above.

[5]
The propylene-based polymer (A) has two peaks in the molecular weight distribution curve measured by GPC, and the ratio (MH/ML) of the peak molecular weight MH on the high molecular weight side and the peak molecular weight ML on the low molecular weight side is The unstretched film according to any one of [1] to [4], which is 50 or more.

[6]
The unstretched film according to any one of [1] to [5], wherein the degree of axial orientation of the PP (110) plane specified by wide-angle X-ray diffraction measurement is 0.85 or more.

The first aspect of the present invention further relates to [7] below.

[7]
A laminate having a sealant film body and a surface layer in this order, wherein the surface layer is any of the above [1] or [3] to [6] (where [1] is directly or indirectly referred to). A sealant film that is a non-stretched film.

The second aspect of the present invention further relates to [8] below.

[8]
A laminate having an outer layer, an intermediate layer and a sealant layer in this order, wherein the intermediate layer is the above [2] or [3] to [6] (provided that [2] is directly or indirectly referred to). A multilayer sealant film that is an unstretched film of any of

The unstretched film of the first aspect of the present invention is excellent in well-balanced rigidity and low-temperature heat-sealing performance (that is, a low seal initiation temperature, which will be described later).

The non-stretched film of the second aspect of the present invention has excellent rigidity and excellent sealing performance (that is, it has a low sealing initiation temperature, which will be described later).

Hereinafter, a mode for carrying out the present invention will be described.

[Unstretched film]
The unstretched film of the first aspect of the present invention is a propylene-based polymer composition (X1 ).

Further, the non-stretched film of the second aspect of the present invention is a propylene-based polymer composition containing a propylene-based polymer (A) and a propylene/α-olefin copolymer (B2) described below. (X2).

Hereinafter, the propylene/α-olefin copolymer (B1) and the propylene/α-olefin copolymer (B2) are collectively referred to as "propylene/α-olefin copolymer It is also described as “union (B)”.

Further, when there is no particular need to distinguish between the propylene-based polymer composition (X1) and the propylene-based polymer composition (X2), they may be collectively referred to as "propylene-based polymer composition (X)." Describe.

The details of the measurement conditions for each requirement are described in the Examples column.

[Propylene polymer (A)]
The propylene polymer (A) contains 20 to 50% by mass of the propylene polymer (a1) having a limiting viscosity [η] of 10 to 12 dl/g measured in a tetralin solvent at 135°C, and 135 ℃, 50 to 80% by mass of the propylene polymer (a2) having an intrinsic viscosity [η] measured in a tetralin solvent in the range of 0.5 to 1.5 dl/g [however, the propylene polymer (a1 ) and the propylene-based polymer (a2) is 100% by mass. 〕include.

Hereinafter, the intrinsic viscosity [η] measured in a tetralin solvent at 135°C is also simply referred to as "intrinsic viscosity [η]". The mass fractions of the propylene-based polymer (a1) and the propylene-based polymer (a2) are based on the total amount of (a1) and (a2).

<Propylene polymer (a1)>
The intrinsic viscosity [η] of the propylene-based polymer (a1) is in the range of 10-12 dl/g, preferably in the range of 10.5-11.5 dl/g. Further, the mass fraction of the propylene-based polymer (a1) in the propylene-based polymer (A) is in the range of 20 to 50% by mass, preferably 20 to 45% by mass, more preferably 20 to 40% by mass, More preferably, it is in the range of 22-40% by mass.

Examples of the propylene-based polymer (a1) include propylene homopolymers and copolymers of propylene and α-olefins having 2 to 8 carbon atoms (excluding propylene). Examples of α-olefins having 2 to 8 carbon atoms include ethylene, 1-butene, 1-hexene, 1-octene and 4-methyl-1-pentene. Ethylene is preferred as these α-olefins. One or more α-olefins can be used.

In a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms, the content of structural units derived from propylene is usually 90% by mass or more, preferably 95% by mass or more, more preferably 98% by mass or more. and the content of structural units derived from α-olefins having 2 to 8 carbon atoms (excluding propylene) is usually 10% by mass or less, preferably 5% by mass or less, more preferably 2% by mass or less. is. The content ratio can be measured by ¹³ C-NMR.

When the intrinsic viscosity [η] of the propylene-based polymer (a1) is within the range of 10 to 12 dl/g, it is preferable from the viewpoint of suppressing the number of fish eyes (FE) in the film obtained from the polymer composition.

On the other hand, when the intrinsic viscosity [η] of the propylene-based polymer (a1) exceeds 12 dl/g, the film formability tends to deteriorate and the film surface appearance tends to deteriorate. Further, when the intrinsic viscosity [η] of the propylene-based polymer (a1) is less than 10 dl/g, the resulting film tends to have insufficient rigidity, heat resistance and gas barrier properties.

When the mass fraction of the propylene-based polymer (a1) is less than 20% by mass, the resulting polymer composition tends to have insufficient melt tension, and the resulting film tends to have insufficient rigidity, heat resistance and gas barrier properties. If it exceeds 50% by mass, it tends to cause poor appearance during film molding.

The propylene-based polymer (a1) can be used alone or in combination of two or more.

<Propylene polymer (a2)>
The intrinsic viscosity [η] of the propylene-based polymer (a2) is in the range of 0.5 to 1.5 dl/g, preferably 0.6 to 1.5 dl/g, more preferably 0.8 to 1.5 dl/g. It is in the range of 5 dl/g. Further, the mass fraction of the propylene-based polymer (a2) in the propylene-based polymer (A) is in the range of 50 to 80% by mass, preferably 55 to 80% by mass, more preferably 60 to 80% by mass, More preferably, it is in the range of 60-78% by mass.

Examples of the propylene-based polymer (a2) include propylene homopolymers and copolymers of propylene and α-olefins having 2 to 8 carbon atoms (excluding propylene). Examples of α-olefins having 2 to 8 carbon atoms include ethylene, 1-butene, 1-hexene, 1-octene and 4-methyl-1-pentene. Ethylene is preferred as these α-olefins. One or more α-olefins can be used.

In a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms, the content of structural units derived from propylene is usually 90% by mass or more, preferably 93% by mass or more, more preferably 94% by mass or more. and the content of structural units derived from α-olefins having 2 to 8 carbon atoms (excluding propylene) is usually 10% by mass or less, preferably 7% by mass or less, more preferably 6% by mass or less. is. The content ratio can be measured by ¹³ C-NMR.

If the intrinsic viscosity [η] of the propylene-based polymer (a2) is less than 0.5 dl/g, the melt tension of the resulting polymer composition will be insufficient, and the resulting film will tend to have poor fisheyes. If the intrinsic viscosity [η] exceeds 1.5 dl/g, the viscosity tends to be high and the film formability tends to deteriorate.

If the mass fraction of the propylene-based polymer (a2) is less than 50% by mass, it tends to cause poor appearance during film molding. In addition, the rigidity, heat resistance and gas barrier properties of the resulting film tend to be insufficient.

The propylene-based polymer (a2) can be used alone or in combination of two or more.

<Additive>
Additives such as an antioxidant, a neutralizer, a flame retardant, and a crystal nucleating agent can be added to the propylene-based polymer (A), if necessary. Additives can be used alone or in combination of two or more. The proportion of the additive is not particularly limited and can be adjusted as appropriate.

<Properties of propylene-based polymer (A)>
The propylene-based polymer (A) preferably has a melt flow rate (MFR) of 0.01 to 5 g/10 minutes, more preferably 0.05 to 4 g/10 minutes, measured at 230°C under a load of 2.16 kg. , more preferably in the range of 0.1 to 3 g/10 minutes. When the MFR of the propylene-based polymer (A) is within the above range, the film formability is excellent.

The propylene-based polymer (A) preferably has a melt tension (MT) measured at 230°C in the range of 5 to 30 g, more preferably 7 to 25 g, and even more preferably 10 to 20 g. When the MT of the propylene-based polymer (A) is within the above range, the film formability is excellent.

Melt tension (MT) can be measured with the following equipment and conditions.

・Apparatus: Capilograph 1C (trade name) manufactured by Toyo Seiki Co., Ltd.
・Temperature: 230℃
・Orifice: L=8mm, D=2.095mm
・Extrusion speed: 15 mm/min ・Take-up speed: 15 m/min The area ratio of the high molecular weight region of 10,000 or more (corresponding to the mass ratio of the high molecular weight component having a molecular weight of 1,500,000 or more) is preferably 7% or more, more preferably 10% or more, and still more preferably 12% or more. The upper limit of the area ratio is, for example, 30%, preferably 25%. The fact that the area ratio of the high-molecular-weight region occupies a specific ratio or more means that the propylene-based polymer (A) contains a high-molecular-weight component having a molecular weight of 1,500,000 or more. At least part of this high molecular weight component is a high molecular weight component having an intrinsic viscosity [η] of 10 to 12 dl/g. Therefore, if the ratio of the high molecular weight component is within the above range, the melt tension of the polymer composition will be more excellent.

The propylene-based polymer (A) preferably has two peaks in the molecular weight distribution curve measured by GPC. Here, the ratio (MH/ML) of the peak molecular weight MH on the high molecular weight side to the peak molecular weight ML on the low molecular weight side is preferably 50 or more, more preferably 70 or more, and even more preferably 90 or more. The upper limit of the ratio (MH/ML) is, for example, 500, preferably 300. The fact that the molecular weight distribution curve has two peaks and MH/ML is a specific value or more indicates that the polymer has a high content of high molecular weight components and a high intrinsic viscosity [η]. Therefore, the propylene-based polymer (A) having such an aspect contributes to improvement of melt tension and improvement of rigidity and heat resistance when formed into a film.

The propylene-based polymer (A) preferably has a peak molecular weight ML on the low molecular weight side of the molecular weight distribution curve measured by GPC of 100,000 or less, more preferably 80,000 or less, from the viewpoint of viscosity and film formability. More preferably, it is 50,000 or less.

<Method for Producing Propylene Polymer (A)>
Examples of the method for producing the propylene-based polymer (A) include various known production methods, such as those described in [0038] to [0075] of International Publication No. 2021/025142.

[Propylene/α-olefin copolymer (B)]
The propylene/α-olefin copolymer (B1) has a melt flow rate (MFR) of 0.1 to 30 g/10 minutes measured under a load of 2.16 kg at 230°C, and measured in a tetralin solvent at 135°C. The intrinsic viscosity [η] of more than 1.5 dl / g and 5.0 dl / g or less, and a copolymer containing 5.5 mol% or more of structural units derived from α-olefins (excluding propylene) It is a polymer.

The propylene/α-olefin copolymer (B2) has a melt flow rate (MFR) of 0.1 to 30 g/10 minutes measured under a load of 2.16 kg at 230°C, and measured in a tetralin solvent at 135°C. has a limiting viscosity [η] of more than 1.5 dl/g and 5.0 dl/g or less, and a structural unit derived from an α-olefin (excluding propylene) is 1 mol% or more and 5.5 mol% It is a copolymer containing less than

The intrinsic viscosity [η] of the propylene/α-olefin copolymer (B) is more than 1.5 dl/g and 5.0 dl/g or less, preferably more than 1.5 dl/g and 4.5 dl/g or less. , more preferably more than 1.5 dl/g and less than or equal to 4.0 dl/g, more preferably more than 1.5 dl/g and less than or equal to 2.5 dl/g. When the propylene/α-olefin copolymer (B) having the intrinsic viscosity [η] within the above range is used, the productivity during film formation is good, and the resulting film has good impact resistance.

The melt flow rate (MFR) of the propylene/α-olefin copolymer (B) measured at 230°C under a load of 2.16 kg is 0.1 to 30 g/10 minutes, preferably 0.3 to 10 g. /10 minutes, more preferably 0.5 to 10 g/10 minutes. When the propylene/α-olefin copolymer (B) having an MFR within the above range is used, productivity during film formation is good, and the resulting film has good impact resistance.

The melting point (Tm) of the propylene/α-olefin copolymer (B1), specifically the melting point (Tm) measured using a differential scanning calorimeter (DSC) under the conditions employed in the examples described later, is , preferably 120 to 170°C, more preferably 125 to 170°C, still more preferably 125 to 135°C. The melting point (Tm) is preferably within the above range from the viewpoint of moldability and heat resistance.

The melting point (Tm) of the propylene/α-olefin copolymer (B2), specifically the melting point (Tm) measured using a differential scanning calorimeter (DSC) under the conditions employed in the examples described later, is , preferably 120 to 170°C, more preferably 125 to 170°C, even more preferably 130 to 170°C, and particularly preferably 130 to 155°C. The melting point (Tm) is preferably within the above range from the viewpoint of moldability and heat resistance.

The molecular weight distribution (Mw/Mn) of the propylene/α-olefin copolymer (B) measured by gel permeation chromatography (GPC) is preferably at least 4.0, more preferably from 4.0 to 6.5, more preferably 4.0 to 6.0. Here, Mn is the number average molecular weight and Mw is the weight average molecular weight.

Examples of the propylene/α-olefin copolymer (B) include propylene/α-olefin random copolymers, block-type propylene copolymers (propylene homopolymers or propylene/α-olefin random copolymers, mixture with amorphous or low-crystalline propylene/α-olefin random copolymer) and random block polypropylene.

Examples of α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 4-methyl-1-pentene, 3-methyl-1-pentene and the like. and α-olefins having 2 to 12 carbon atoms. Among these α-olefins, ethylene, 1-butene, 1-hexene, 1-octene and 4-methyl-1-pentene are preferred. One or more α-olefins can be used.

In the propylene/α-olefin copolymer (B1), the content of structural units derived from α-olefins (excluding propylene) is determined by the content of structural units derived from propylene and the structure derived from α-olefins. Assuming that the total amount of units is 100 mol %, it is 5.5 mol % or more, preferably 5.5 to 9.0 mol %, more preferably 5.5 to 7.0 mol %.

In the propylene/α-olefin copolymer (B2), the content of structural units derived from α-olefins (excluding propylene) is 1 mol% in the case of the propylene/α-olefin copolymer (B2). 5.5 mol % or more, preferably 1.5 to 4.5 mol %, more preferably 2.0 to 4.0 mol %.

The content ratio can be measured by ¹³ C-NMR.

The propylene/α-olefin copolymer (B) can be produced by copolymerizing propylene with another α-olefin using a catalyst, and a commercially available polypropylene resin can be used. can. As the catalyst, for example, a solid catalyst component containing magnesium, titanium and halogen as essential components, and an organometallic compound catalyst such as an organoaluminum compound, described in [0050] to [0075] of International Publication No. 2021/025142. a catalyst formed from a component and an electron-donating compound catalyst component such as an organosilicon compound; and a metallocene catalyst using a metallocene compound as one component of the catalyst.

The propylene-based polymer (A) and the propylene/α-olefin copolymer (B) may each contain structural units derived from at least one biomass-derived monomer (propylene). The same kind of monomers constituting the polymer may be only biomass-derived monomers, may be only fossil fuel-derived monomers, or may be both biomass-derived monomers and fossil fuel-derived monomers. Biomass-derived monomers are monomers derived from any renewable natural raw materials and their residues, such as plant-derived or animal-derived, including fungi, yeast, algae and bacteria, and have ¹ C isotope as carbon. It contains about ×10 ⁻¹² , and the biomass carbon concentration (pMC) measured according to ASTM D6866 is about 100 (pMC). A biomass-derived monomer (propylene) can be obtained, for example, by a conventionally known method.

It is preferable that the propylene-based polymer (A) or the propylene/α-olefin copolymer (B) contains structural units derived from biomass-derived monomers from the viewpoint of reducing the environmental load. If the polymer production conditions such as the polymerization catalyst and the polymerization temperature are the same, even if the raw olefin is a propylene-based polymer containing a biomass-derived olefin or a propylene/α-olefin copolymer, the ¹⁴ C isotope is reduced to 1. The molecular structure other than the ratio of about ×10 ^-12 is equivalent to that of a propylene-based polymer or a propylene/α-olefin copolymer composed of fossil fuel-derived monomers. Therefore, these performances are said to be unchanged.

The propylene-based polymer (A) and the propylene/α-olefin copolymer (B) may contain structural units derived from at least one chemically recycled monomer (propylene). The same kind of monomers constituting the polymer may be only chemically recycled monomers, or may include chemically recycled monomers and fossil fuel-derived monomers and/or biomass-derived monomers. A chemically recycled monomer (propylene) can be obtained, for example, by a conventionally known method.

It is preferable that the propylene-based polymer (A) and the propylene/α-olefin copolymer (B) contain structural units derived from monomers derived from chemical recycling from the viewpoint of reducing the environmental load (mainly reducing waste). Even if the raw material monomer contains a monomer derived from chemical recycling, the monomer derived from chemical recycling is a monomer obtained by depolymerizing or thermally decomposing a polymer such as waste plastic into a monomer unit such as ethylene, or using the monomer as a raw material. Since it is a manufactured monomer, if the polymer manufacturing conditions such as the polymerization catalyst, polymerization process, and polymerization temperature are the same, the molecular structure is a propylene-based polymer or a propylene/α-olefin copolymer consisting of a fossil fuel-derived monomer. is equivalent to Therefore, these performances are said to be unchanged.

[Other components (additives)]
The propylene-based polymer composition (X) contains a weather stabilizer, a heat stabilizer, an antistatic agent, a slip agent, an antiblocking agent, an antifogging agent, a nucleating agent, Decomposing agent, pigment, dye, plasticizer, hydrochloric acid absorbent, antioxidant, cross-linking agent, cross-linking accelerator, reinforcing agent, filler, softener, processing aid, activator, moisture absorbent, adhesive, flame retardant, Additives such as release agents may be included. Additives can be used alone or in combination of two or more.

[Preparation and physical properties of propylene-based polymer composition (X)]
The propylene-based polymer composition (X) can be produced by adopting any known method. A method of mixing other components with a Henschel mixer, a V-blender, a ribbon blender, a tumbler blender, etc., or after the mixing, a single screw extruder, a twin screw extruder, a kneader, a Banbury mixer, a roll, etc. melt and knead. After that, a method of granulating or pulverizing may be mentioned.

In the propylene-based polymer composition (X1), the content of the propylene-based polymer (A) with respect to a total of 100 parts by mass of the propylene-based polymer (A) and the propylene/α-olefin copolymer (B1) is 1 to 10 parts by mass, preferably 3 to 10 parts by mass, more preferably 4 to 10 parts by mass, and the content of the propylene/α-olefin copolymer (B1) is 90 to 99 parts by mass. , preferably 90 to 97 parts by mass, more preferably 90 to 96 parts by mass.

The unstretched film according to the present invention, in which the contents of the propylene-based polymer (A) and the propylene/α-olefin copolymer (B) are within the above range, has excellent rigidity and heat-sealing performance in a well-balanced manner. It also looks great when sealed.

On the other hand, when the content of the propylene/α-olefin copolymer (B1) is less than 90 parts by mass, the sealing performance of the film tends to deteriorate, that is, the heat sealing temperature tends to increase, and when the film is heat sealed, may deteriorate the appearance of When the content of the propylene/α-olefin copolymer (B1) exceeds 99 parts by mass, the rigidity of the film tends to deteriorate, that is, the tensile modulus tends to decrease.

In the propylene-based polymer composition (X2), the content of the propylene-based polymer (A) with respect to a total of 100 parts by mass of the propylene-based polymer (A) and the propylene/α-olefin copolymer (B2) is 1 to 18 parts by mass, preferably 3 to 10 parts by mass, more preferably 4 to 10 parts by mass, and the content of the propylene/α-olefin copolymer (B2) is 82 to 99 parts by mass. , preferably 90 to 97 parts by mass, more preferably 90 to 96 parts by mass.

When the content of the propylene/α-olefin copolymer (B2) is less than 82 parts by mass, the sealing performance of the film tends to deteriorate, that is, the heat sealing temperature tends to increase. When the content of the propylene/α-olefin copolymer (B2) exceeds 99 parts by mass, the rigidity of the film tends to deteriorate, that is, the tensile modulus tends to decrease.

In the present invention, from the viewpoint of rigidity and heat resistance, and from the viewpoint of reducing fish eyes, a propylene-based polymer containing a propylene-based polymer (a1) and a propylene-based polymer (a2) obtained by batchwise multistage polymerization is used. It is preferable to prepare the propylene-based polymer composition (X) by mixing the coalescence (A) and the propylene/α-olefin copolymer (B).

The molecular weight distribution (Mw/Mn) of the propylene-based polymer composition (X) measured by gel permeation chromatography (GPC) is preferably 5.0 or more, more preferably 5.5 or more, and still more preferably. is 6.0 or more, and the upper limit is not particularly limited, but is 25, for example.

In the present invention, the propylene-based polymer (a2), the propylene/α-olefin copolymer (B), and the propylene-based polymer (a1) having a higher molecular weight than these are used. The composition (X) has a large molecular weight distribution. Therefore, it is presumed that the degree of orientation in the MD direction of the molding increases during film molding of the propylene-based polymer composition (X), and the orientation increases the crystallization of the propylene-based polymer. And it is thought that a film having excellent gas barrier properties can be obtained.

The melt flow rate (MFR) of the propylene-based polymer composition (X) measured at 230° C. under a load of 2.16 kg is usually 1 to 20 g/10 min, preferably 2 to 15 g/10 min, more It is preferably 3 to 10 g/10 minutes.

[Unstretched film]
The unstretched film of the present invention is formed from the propylene-based polymer composition (X). The unstretched film of the present invention exhibits higher rigidity, heat resistance and gas barrier properties than conventional unstretched polypropylene films. The unstretched film is used, for example, as a packaging material for foods, beverages, industrial parts, miscellaneous goods, toys, daily necessities, office supplies, medical supplies, and the like.

The thickness of the unstretched film of the present invention is usually less than 200 μm, preferably 10-150 μm, more preferably 15-100 μm. Since the unstretched film of the present invention is excellent in rigidity, it can be easily made into a thin film.

In the unstretched film of the present invention, the degree of axial orientation of the PP (110) plane specified by wide-angle X-ray diffraction measurement (details of the measurement method will be described later) is preferably 0.85 or more, more preferably is greater than or equal to 0.88. When the degree of axial orientation is within this range, the molecules are sufficiently oriented and the tensile modulus of the film increases. The upper limit of the degree of axial orientation may be, for example, 0.91. The value of the degree of axial orientation can be increased or decreased by changing the intrinsic viscosity [η] of the propylene-based polymer (a1), for example, by changing the film forming speed.

Examples of film manufacturing methods include extrusion molding methods such as the T-die method and inflation method, compression molding methods, calendar molding methods, and casting methods.

Film molding can be performed, for example, as follows. The above components constituting the propylene-based polymer composition (X) may be directly added to a hopper or the like of a film forming machine, or may be mixed using a ribbon blender, Banbury mixer, Henschel mixer, super mixer or the like. may be mixed in advance, or further melt-kneaded using a kneader such as a single-screw or twin-screw extruder or a roll to obtain the propylene-based polymer composition (X), followed by film forming.

A specific example of film production will be described by the T-die method. The above components are put into an extruder, and usually melt-kneaded at a temperature of 180 to 280 ° C., preferably 200 to 270 ° C., and then T-die. A film is extruded through a die lip, and the molten film is cooled and taken up by a take-up device such as a nip roll to obtain a film.

Cooling methods for molten films include, for example, air knife method or air chamber method using rolls and air cooling, polishing roll method, swing roll method, narrow pressure cooling method such as belt casting method, contact with refrigerant such as water cooling method, etc. cooling method.

The obtained non-stretched film can be subjected to film treatment methods used for ordinary film molding, such as corona discharge treatment and liquid agent coating treatment.

[Sealant film and multilayer sealant film]
The sealant film of the present invention has the unstretched film of the first aspect of the present invention as a surface layer.

The sealant film of the present invention consists of a laminate having a sealant film main body and a surface layer in this order. Methods for producing the sealant film include a coextrusion method and an extrusion coating method.

The sealant film main body and surface layer may each be a single layer or multiple layers.

The multilayer sealant film of the present invention has the unstretched film of the second aspect of the present invention as an intermediate layer.

The multilayer sealant film of the present invention consists of a laminate having an outer layer, an intermediate layer and a sealant layer in this order. Methods for producing the multilayer sealant film include co-extrusion and extrusion coating.

The outer layer, intermediate layer and sealant layer may each be a single layer or multiple layers.

Examples of materials for the sealant layer include materials used for conventional sealant layers, such as ethylene-based resins.

The sealant film main body and the outer layer include a base material layer.

The base layer is made of a material with relatively high rigidity and strength. Examples of the materials include polyamide resins such as nylon 11 and nylon 12, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyolefin resins such as polyethylene resin and polypropylene resin, polyvinylidene chloride resin, and ethylene-vinyl acetate copolymer. Films containing at least one thermoplastic resin selected from the group consisting of saponified products, polycarbonate resins, polystyrene resins, and acrylic resins (which may be stretched films), metal foils, metal vapor deposition films, inorganic oxide vapor deposition At least one selected from ceramic deposited films such as films, paper, nonwoven fabrics, and laminates thereof may be used.

The thickness of the base material layer is usually about 5 to 50 μm.

Examples of the sealant film main body and the outer layer include, in addition to the base layer, a barrier layer for gases such as water vapor and oxygen, a sound absorbing layer, a light shielding layer, an adhesive layer, an adhesive layer, a colored layer, a conductive layer, and a reproduction layer. A resin-containing layer (these layers listed in addition to the base material layer are also collectively referred to as "another layer").

In the sealant film, examples of materials for forming the other layers include olefin polymer compositions other than the propylene polymer composition (X1) and gas barrier resin compositions. , and adhesive resin compositions.

In the multi-layer sealant film, examples of materials for forming the other layers include olefin-based polymer compositions other than the propylene-based polymer composition (X2) and gas-barrier resin compositions. products, and adhesive resin compositions.

Since the sealant film of the present invention has the unstretched film of the first aspect of the present invention as a surface layer, heat sealing at a low temperature, specifically lower than 140 ° C., preferably 135 ° C. or lower, It enables sealing at the sealing initiation temperature described later and has a high tensile modulus. Moreover, the appearance when heat-sealed is also excellent.

The multilayer sealant film of the present invention has the unstretched film of the second aspect of the present invention as an intermediate layer. Therefore, the intermediate layer contributes to heat sealing at a lower temperature than when a propylene homopolymer is used for the intermediate layer. Also, the multi-layer sealant film of the present invention has a higher tensile modulus than when a conventional propylene/α-olefin copolymer is used.

The unstretched film, sealant film and multi-layer sealant film of the present invention are suitable for various food packaging fields such as fresh foods such as vegetables and fish meat, dried foods such as snacks and noodles, water foods such as soups and pickles; It is used as a packaging film in a wide range of packaging fields, such as packaging for various forms of medical products such as powders and liquids, medical peripheral materials, etc.; packaging for various electrical equipment such as cassette tapes and electrical parts. can do.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. Various properties of the polymer, polymer composition and unstretched film obtained in each example were measured and evaluated as follows.

(1) Mass Fraction In Production Example 1, the propylene-based polymer obtained in the first step (corresponding to the propylene-based polymer (a1)) and the propylene-based polymer obtained in the second step (propylene-based The mass fraction of the polymer (a2)) was obtained from the heat release amount of reaction heat generated during polymerization.

(2) Intrinsic viscosity [η]
The intrinsic viscosity [η] (dl/g) was measured at 135°C in a tetralin solvent. The intrinsic viscosity [η] ₂ of the propylene-based polymer (corresponding to the propylene-based polymer (a2)) obtained in the second stage is a value calculated from the following formula.

[η] ₂ = ([η] _total x 100 - [η] ₁ x W ₁ )/W ₂
[η] _total : Intrinsic viscosity of the entire propylene-based polymer [η] ₁ : Intrinsic viscosity of the propylene-based polymer obtained in the first stage W ₁ : Mass of the propylene-based polymer obtained in the first stage Fraction (%)
W ₂ : mass fraction (%) of the propylene-based polymer obtained in the second stage

(3) Comonomer content Using o-dichlorobenzene-d4 as a measurement solvent, measurement temperature 120 ° C., spectrum width 20 ppm, pulse repetition time 7.0 seconds, pulse width 6.15 μ seconds ((450 pulses) measurement conditions ( A ¹ H-NMR spectrum was measured at 400 MHz with a JEOL ECX400P) to calculate the comonomer content.

(4) Melt flow rate (MFR)
Melt flow rate (MFR) (g/10 minutes) was measured according to JIS-K7210 at a temperature of 230°C and a load of 2.16 kgf (21.2 N).

(5) Proportion of high molecular weight region with molecular weight of 1,500,000 or more, ML, MH/ML
The ratio of the high molecular weight region having a molecular weight of 1,500,000 or more is the region surrounded by the molecular weight distribution curve (specifically, the molecular weight distribution curve and the horizontal axis) measured by gel permeation chromatography (GPC) using the following equipment and conditions. It is the area ratio of the high molecular weight region having a molecular weight of 1,500,000 or more to the total area of . Here, the horizontal axis is molecular weight (logarithmic value) and the vertical axis is dw/dLog(M) [w: integrated mass fraction, M: molecular weight]. The peak molecular weight MH on the high molecular weight side and the peak molecular weight ML on the low molecular weight side of the molecular weight distribution curve were obtained to calculate MH/ML.

GPC measurement device Gel permeation chromatograph HLC-8321 GPC/HT type (manufactured by Tosoh Corporation) Analysis device Data processing software Empower 3 (manufactured by Waters) Measurement conditions Column: TSKgel GMH6-HT×2 + TSKgel GMH6-HTL×2
(Both are 7.5mmI.D.x30cm, manufactured by Tosoh Corporation)
Column temperature: 140℃
Mobile phase: o-dichlorobenzene (containing 0.025% BHT)
Detector: Differential refractometer Flow rate: 1.0mL/min
Sample concentration: 0.1% (w/v)
Injection Volume: 0.4mL
Sampling time interval: 1s
Column calibration: Monodisperse polystyrene (manufactured by Tosoh Corporation)
Molecular weight conversion: PP conversion/general-purpose calibration method (PS (polystyrene) viscosity conversion coefficient K _PS = 0.000138dl/g,
α _PS =0.700, PP (polypropylene) viscosity conversion coefficient K _PP =0.000242dl/g, α _PP =0.707)

(6) Melting Point The crystalline melting point was determined according to JIS-K7121 using a differential scanning calorimeter (DSC, manufactured by PerkinElmer (Diamond DSC)) under the following measurement conditions. The apex of the endothermic peak in the fourth step was defined as the crystalline melting point (Tm) when the measurement was performed under the following measurement conditions. When there are multiple endothermic peaks, the endothermic peak apex at which the height of the peak is maximum is defined as the crystalline melting point (Tm).

(Measurement condition)
Measurement environment: Nitrogen gas atmosphere Sample amount: 5 mg
Sample shape: Press film (molded at 230°C, thickness 400 µm)
Sample pan: Aluminum sample pan with a flat bottom First step: The temperature is raised from 30°C to 200°C at 320°C/min and held for 10 minutes.

Second step: Lower the temperature to 30°C at 20°C/min.

Third step: Hold at 30°C for 10 minutes.

Fourth step: Raise the temperature to 200°C at 20°C/min.

(7) Film elastic modulus Tensile elastic modulus (MPa) was measured according to the method of JIS K7161. The measurement was performed at 23° C. in the extrusion direction (MD) of molding. It can be said that the higher the tensile modulus, the higher the rigidity.

(8) Sealing start temperature Using a heat seal tester manufactured by Toyo Seiki, cut out a test piece of 100 mm width and 150 mm length from the film manufactured in Examples etc., fold it in half, and set the heater temperature to zero pressure. After heat sealing under conditions of 2 MPa and a sealing time of 1.0 second, the sealed test piece was cut into a test piece with a width of 15 mm, and peeled at a test speed of 300 mm / min using Orientec's Tensilon RT1225 type. Strength (N/15mm) was measured. The measurement was repeated by changing the heater temperature in increments of 1° C., and the minimum value of the heater temperature (hereinafter referred to as “seal initiation temperature”) for making the peel strength 2.94 N/15 mm or more was specified.

(9) Degree of axial orientation Using a wide-angle X-ray diffractometer (RINT2550 manufactured by Rigaku Corporation, accessory: rotating sample stage, X-ray source: CuKα, output: 40 kV, 370 mA, detector: scintillation counter), the MD direction is used as a reference. The azimuth angle distribution intensity of the crystal plane peak (110) plane was measured by stacking them as an axis and fixing them to a sample holder. In the resulting azimuth angle distribution curve (X-ray interferogram), the degree of orientation F (degree of axial orientation) was calculated from the following formula from the degree of crystallinity and the half width (α) of the peak and evaluated.

Orientation (F) = (180°-α)/180°
(α is the half width of the peak derived from the orientation)

[Production Example 1]
(1) Preparation of magnesium compound A reactor with a stirrer (inner volume: 500 liters) was sufficiently purged with nitrogen gas, and 97.2 kg of ethanol, 640 g of iodine, and 6.4 kg of metallic magnesium were added and stirred under reflux conditions. The reaction was continued until hydrogen gas was no longer generated from the system, and a solid reaction product was obtained. The target magnesium compound (solid catalyst carrier) was obtained by drying the reaction solution containing the solid reaction product under reduced pressure.

(2) Preparation of solid titanium catalyst component 30 kg of the magnesium compound (not pulverized) and 150 purified heptane (n-heptane) were placed in a reaction tank (with internal volume of 500 liters) equipped with a stirrer that was sufficiently purged with nitrogen gas. liters, 4.5 liters of silicon tetrachloride, and 5.4 liters of di-n-butyl phthalate were added. The inside of the system was kept at 90°C, and 144 liters of titanium tetrachloride was added while stirring. After reacting at 110°C for 2 hours, the solid component was separated and washed with purified heptane at 80°C. Further, 228 liters of titanium tetrachloride was added, reacted at 110° C. for 2 hours, and thoroughly washed with purified heptane to obtain a solid titanium catalyst component.

(3) Preparation of prepolymerization catalyst To 200 mL of heptane, 10 mmol of triethylaluminum, 2 mmol of dicyclopentyldimethoxysilane, and 1 mmol of the solid titanium catalyst component obtained in (2) were added in terms of titanium atoms. The internal temperature was kept at 20° C., and propylene was continuously introduced while stirring. After 60 minutes, the stirring was stopped, and as a result, a prepolymerized catalyst slurry was obtained in which 4.0 g of propylene was polymerized per 1 g of the solid titanium catalyst component.

(4) Polymerization 336 liters of propylene was introduced into a 600 liter autoclave and heated to 60°C. Thereafter, 8.7 mL of triethylaluminum, 11.4 mL of dicyclopentyldimethoxysilane, and 2.9 g of the prepolymerization catalyst slurry obtained in (3) above as a solid titanium catalyst component were charged to initiate polymerization. After 75 minutes from the initiation of polymerization, the temperature was lowered to 50° C. over 10 minutes (completion of the first-stage polymerization).

The intrinsic viscosity [η] of the propylene-based polymer (a1-1) polymerized under the same conditions as in the first stage was 11 dl/g.

After the temperature was lowered, hydrogen was continuously introduced so that the pressure remained constant at 3.3 MPaG, and polymerization was carried out for 151 minutes. Then, the vent valve was opened, and unreacted propylene was purged through an integrating flow meter (completion of second-stage polymerization).

Thus, 51.8 kg of powdery propylene-based polymer was obtained. The ratio of the propylene-based polymer (a1-1) produced in the first-stage polymerization to the propylene-based polymer, calculated from the mass balance, was 25% by mass, and the propylene-based polymer produced in the second-stage polymerization The proportion of polymer (a2-1) was 75% by mass, and the intrinsic viscosity [η] was 0.99 dl/g.

To this propylene-based polymer, as antioxidants, Irganox 1010 (manufactured by BASF) 2000 ppm, Irgaphos 168 (manufactured by BASF) 2000 ppm, Sandstab P-EPQ (manufactured by Clariant Japan) 1000 ppm, and a neutralizer, Stair 1000 ppm of calcium phosphate was added and melt-kneaded with a twin-screw extruder to obtain a propylene-based polymer (A-1) in the form of pellets. The MFR of the propylene polymer (A-1) thus finally obtained was 1.2 g/10 minutes.

Table 1 summarizes the physical properties of the polymer obtained in Production Example 1.

[Production Example 2]
(1) Preparation of magnesium compound A reactor with a stirrer (inner volume: 500 liters) was sufficiently purged with nitrogen gas, and 97.2 kg of ethanol, 640 g of iodine, and 6.4 kg of metallic magnesium were added and stirred under reflux conditions. The reaction was continued until hydrogen gas was no longer generated from the system, and a solid reaction product was obtained. The target magnesium compound (solid catalyst carrier) was obtained by drying the reaction solution containing the solid reaction product under reduced pressure.

(2) Preparation of solid titanium catalyst component Into a reactor with a stirrer (inner volume: 500 liters) sufficiently purged with nitrogen gas, 30 kg of the magnesium compound (not pulverized), 150 liters of purified heptane (n-heptane), 4.5 liters of silicon tetrachloride and 5.4 liters of di-n-butyl phthalate were added. The inside of the system was kept at 90°C, and 144 liters of titanium tetrachloride was added while stirring. After reacting at 110°C for 2 hours, the solid component was separated and washed with purified heptane at 80°C. Further, 228 liters of titanium tetrachloride was added, reacted at 110° C. for 2 hours, and thoroughly washed with purified heptane to obtain a solid titanium catalyst component.

(3) Pretreatment 230 liters of purified heptane was charged into a reactor with a stirrer and having an internal volume of 500 liters, 25 kg of the solid catalyst component, triethylaluminum at 1.0 mol/mol per titanium atom in the solid catalyst component, and diethylaluminum. Cyclopentyldimethoxysilane was supplied at a ratio of 1.8 mol/mol to titanium atoms in the solid catalyst component. Thereafter, propylene was introduced until the propylene partial pressure reached 0.3 kgf/cm ² G, and the reaction was carried out at 25°C for 4 hours. After completion of the reaction, the solid catalyst component was washed several times with purified heptane, carbon dioxide was supplied, and the mixture was stirred for 24 hours.

(4) Polymerization In a polymerization apparatus equipped with a stirrer having an internal volume of 200 liters, the treated solid catalyst component was charged at 3 mmol/hr in terms of titanium atoms in the component, triethylaluminum at 4 mmol/kg-PP, and dicyclopentyldimethoxysilane at 1 mmol. Propylene, ethylene, 1-butene and hydrogen were reacted at a polymerization temperature of 80°C and a polymerization pressure (total pressure) of 28 kgf/cm ² G. At this time, the amounts of ethylene and 1-butene supplied and the amount of hydrogen supplied were adjusted so as to obtain desired ethylene and 1-butene contents and MFR. The composition analysis values (gas chromatography analysis) of the gas portion in the polymerization apparatus showed an ethylene concentration of 3.5 mol %, a 1-butene concentration of 4.9 mol %, and a hydrogen concentration of 2.5 mol %.

To the propylene/ethylene/1-butene copolymer thus obtained, as antioxidants, Irganox 1010 (manufactured by BASF) 2000 ppm, Irgaphos 168 (manufactured by BASF) 2000 ppm, Sandstab P-EPQ (manufactured by Clariant Japan) ) 1000 ppm and 1000 ppm of calcium stearate as a neutralizing agent were added and melt-kneaded with a twin-screw extruder to obtain pellet-like propylene/ethylene/1-butene random copolymer (B-1).

[Production Example 3]
In "(4) Polymerization", the composition analysis value (gas chromatographic analysis) of the gas portion in the polymerization apparatus is ethylene concentration of 2.0 mol%, 1-butene concentration of 0 mol%, and hydrogen concentration of 5.5 mol%. A propylene/ethylene random copolymer (B-2) in the form of pellets was obtained in the same manner as in Production Example 2, except that the amounts of ethylene, 1-butene and hydrogen supplied were adjusted as described above.

[Production Example 4]
In "(4) Polymerization", the compositional analysis values (gas chromatography analysis) of the gas section in the polymerization apparatus show an ethylene concentration of 1.6 mol%, a 1-butene concentration of 0 mol%, and a hydrogen concentration of 4.2 mol%. A propylene/ethylene random copolymer (B-3) in the form of pellets was obtained in the same manner as in Production Example 2, except that the amounts of ethylene, 1-butene and hydrogen supplied were adjusted as described above.

[Production Example 5]
In "(4) Polymerization", the composition analysis value (gas chromatography analysis) of the gas portion in the polymerization apparatus was ethylene concentration of 1.7 mol%, 1-butene concentration of 4.0 mol%, and hydrogen concentration of 2.3 mol%. Pellet-like propylene/ethylene/1-butene random copolymer (B-4) was prepared in the same manner as in Production Example 2, except that the ethylene supply amount, 1-butene supply amount, and hydrogen supply amount were adjusted so that Obtained.

[Production Example 6]
In "(4) Polymerization", the composition analysis value (gas chromatography analysis) of the gas portion in the polymerization apparatus is ethylene concentration of 1.3 mol%, 1-butene concentration of 0 mol%, and hydrogen concentration of 3.5 mol%. A propylene/ethylene random copolymer (B-5) in the form of pellets was obtained in the same manner as in Production Example 2, except that the amounts of ethylene, 1-butene and hydrogen supplied were adjusted as in the above.

[Production Example 7: F-704NP]
A trade name “Prime Polypro F-704NP” manufactured by Prime Polymer Co., Ltd. was used. For the sake of convenience, it is described as a production example.

Table 2 summarizes the physical properties of the polymers obtained in Production Examples 2 to 7.

[Examples of the first aspect of the present invention and comparative examples thereof]
[Example 1-1]
5 parts by mass of the propylene-based polymer (A-1) obtained in Production Example 1, and 95 parts by mass of the propylene/ethylene/1-butene random copolymer (B-1) obtained in Production Example 2. A 25 μm thick non-stretched film was produced under the following molding conditions using a non-stretched film forming machine consisting of an extruder (one unit) with a screw diameter of 75 mm and a single-layer die with a width of 600 mm.

・Resin temperature: 248°C
・Chill roll temperature: 30°C
- Forming speed: 150 m/min Table 3 shows the physical properties of the film.

[Example 1-2, Comparative Examples 1-1 to 1-6]
A non-stretched film was produced in the same manner as in Example 1-1, except that the formulation was changed as shown in Table 3.

[Examples and comparative examples according to the second aspect of the present invention]
[Example 2-1]
From 5 parts by mass of the propylene-based polymer (A-1) obtained in Production Example 1 and 95 parts by mass of the propylene/ethylene random copolymer (B-3) obtained in Production Example 4, a screw diameter of 75 mm was prepared. A non-stretched film forming machine having a monolayer die with a width of 600 mm connected to the extruder (one unit) was used to prepare a non-stretched film having a thickness of 25 μm under the following molding conditions.

・Resin temperature: 248°C
・Chill roll temperature: 30°C
- Forming speed: 150 m/min Table 4 shows the physical properties of the film.

[Examples 2-2 to 2-5, Comparative Examples 2-1 to 2-8]
A non-stretched film was produced in the same manner as in Example 2-1, except that the formulation was changed as shown in Table 4.

The above results are summarized in Table 4.

Claims

20 to 50% by mass of the propylene-based polymer (a1) having an intrinsic viscosity [η] in the range of 10 to 12 dl/g measured in a tetralin solvent at 135°C, and 135°C in a tetralin solvent 50 to 80% by mass of the propylene-based polymer (a2) having an intrinsic viscosity [η] in the range of 0.5 to 1.5 dl/g [however, the propylene-based polymer (a1) and the propylene-based polymer (a2) and the total amount of 100% by mass. ] A propylene-based polymer (A) containing
Melt flow rate (230 ° C., 2.16 kg load) is 0.1 to 30 g / 10 minutes, and intrinsic viscosity [η] measured in tetralin solvent at 135 ° C. exceeds 1.5 dl / g and 5.0 dl / g or less, and a propylene/α-olefin copolymer (B1) containing 5.5 mol% or more of structural units derived from an α-olefin (excluding propylene),
The content of the propylene-based polymer (A) is 1 to 10 parts by mass with respect to a total of 100 parts by mass of the propylene-based polymer (A) and the propylene/α-olefin copolymer (B1), An unstretched film comprising a propylene-based polymer composition (X1) containing 90 to 99 parts by mass of the propylene/α-olefin copolymer (B1).
20 to 50% by mass of the propylene-based polymer (a1) having an intrinsic viscosity [η] in the range of 10 to 12 dl/g measured in a tetralin solvent at 135°C, and 135°C in a tetralin solvent 50 to 80% by mass of the propylene-based polymer (a2) having an intrinsic viscosity [η] in the range of 0.5 to 1.5 dl/g [however, the propylene-based polymer (a1) and the propylene-based polymer (a2) The total amount of and is 100% by mass. ] A propylene-based polymer (A) containing
Melt flow rate (230 ° C., 2.16 kg load) is 0.1 to 30 g / 10 minutes, and intrinsic viscosity [η] measured in tetralin solvent at 135 ° C. exceeds 1.5 dl / g and 5.0 dl /g or less, and a propylene/α-olefin copolymer (B2) containing 1 mol% or more and less than 5.5 mol% of structural units derived from an α-olefin (excluding propylene). ,
The content of the propylene-based polymer (A) is 1 to 18 parts by mass with respect to a total of 100 parts by mass of the propylene-based polymer (A) and the propylene/α-olefin copolymer (B2), An unstretched film comprising a propylene-based polymer composition (X2) containing 82 to 99 parts by mass of the propylene/α-olefin copolymer (B2).
The unstretched film according to claim 1 or 2, wherein the propylene-based polymer (A) has a melt flow rate (MFR) of 0.01 to 5 g/10 minutes measured at 230°C under a load of 2.16 kg.
In the propylene-based polymer (A), the area ratio of the high molecular weight region having a molecular weight of 1,500,000 or more in the total area of the region surrounded by the molecular weight distribution curve measured by gel permeation chromatography (GPC) is 7% or more. The unstretched film according to claim 1 or 2.
The propylene-based polymer (A) has two peaks in the molecular weight distribution curve measured by GPC, and the ratio (MH/ML) of the peak molecular weight MH on the high molecular weight side and the peak molecular weight ML on the low molecular weight side is The unstretched film according to claim 1 or 2, which is 50 or more.
The unstretched film according to claim 1 or 2, wherein the degree of axial orientation of the PP (110) plane specified by wide-angle X-ray diffraction measurement is 0.85 or more.
A sealant film which is a laminate having a sealant film main body and a surface layer in this order, wherein the surface layer is the unstretched film according to claim 1.
A multilayer sealant film which is a laminate having an outer layer, an intermediate layer and a sealant layer in this order, wherein the intermediate layer is the non-stretched film according to claim 2.