JP6386874B2 - Polyolefin composition, polyolefin stretched film, and method for producing stretched film - Google Patents

Description

  The present invention relates to a polyolefin-based composition, a polyolefin stretched film, a stretched multilayer film, and a method for producing a stretched film.

In recent years, weight reduction has become an important issue from the viewpoint of resource saving and energy saving, and substitution of various parts from metal to resin has been actively promoted. Among these, polyolefin resins are inexpensive, excellent in moldability, lightweight, excellent in mechanical strength and durability, and therefore have various physical properties, especially in the fields of automobiles and home appliances. Applications are expanding according to the economic value.
In addition, since the required performance of the market for these polyolefin resins is diversified and cannot be handled by a single polyolefin resin, a so-called polymer alloy technique in which a plurality of polyolefin resins are combined is widely used. Furthermore, attempts have been made to increase strength and rigidity by adding various reinforcing agents to polyolefin resins. For example, polypropylene resins such as propylene homopolymers and copolymers are lightweight and excellent in mechanical strength, chemical resistance, weather resistance, and the like, and thus are widely used in various fields.

On the other hand, vinyl chloride resin, which is widely used as a soft material, is known to generate harmful substances in the combustion process, and the development of alternative products is desired.
However, in such polypropylene, it is difficult to obtain a resin composition having a balance between moldability and physical properties.

Therefore, Patent Document 1 discloses (A) a polyolefin-based resin as a polyolefin-based resin composition that is soft and excellent in transparency, has no stickiness, has excellent fluidity at the time of melting, and improves moldability. B) It is disclosed that a propylene polymer satisfying the following requirements (1) to (5) is contained at a mass ratio of 20:80 to 99: 1.
(1) Comprising 50 to 100 mol% of propylene and 0 to 50 mol% of an α-olefin having 2 to 20 carbon atoms other than propylene,
(2) Intrinsic viscosity [η] measured in 135 ° C. tetralin is 0.01 to 0.5 dl / g,
(3) Stereoregularity index [mm] is 50 to 90 mol%,
(4) Melting point (TmD) measured with a differential scanning calorimeter (DSC) is 0 to 120 ° C.,
(5) The molecular weight distribution (Mw / Mn) measured by gel permeation chromatography (GPC) method is 4.0 or less.
However, since the moldability obtained with the polyolefin resin composition has a low elastic modulus, it is preferably used for applications where a soft molded body is required, but for use in commonly used packaging materials. Physical properties such as strength may not be sufficient.

  On the other hand, in general, the crystallization of an olefin polymer consists of two processes, a crystal nucleation process and a crystal growth process, and the nucleating agent has an effect of improving the progress speed of the crystal nucleation process. However, a molded product obtained from an olefin polymer to which a nucleating agent is added is excellent in strength but has a problem that it is brittle and difficult to stretch.

Patent Document 2 discloses a propylene resin composition obtained by adding a nucleating agent to a propylene homopolymer or a propylene copolymer satisfying the following (1) and (2).
(1) The component amount (H25) eluted in hexane at 25 ° C. is 0 to 80% by mass.
(2) In DSC measurement, melting point (Tm (° C.)) is not shown, or when Tm is shown, Δm ≧ 6 × (Tm−140) where Tm and melting endotherm ΔH (J / g) satisfy the following relationship: ).
However, the haze of the film obtained by stretching the above-mentioned propylene-based resin composition is just one step toward the recent request.

JP 2005-2279 A JP 2001-172325 A

The present invention has been made in view of the above circumstances. Compared to conventional olefin-based compositions, even when a nucleating agent is added, stretching in a lower temperature region is possible, and mechanical properties and optics after stretching An object of the present invention is to provide a polyolefin-based composition having excellent characteristics.
Another object of the present invention is to provide a stretched film obtained from a polyolefin-based composition that is excellent in optical properties (for example, haze and gloss) and mechanical properties (for example, elastic modulus).

As a result of intensive studies, the present inventors have achieved the above object by blending the polyolefin composition with an olefin polymer (B) having a specific structure having a relatively low melting endotherm. I found out that The present invention has been completed based on such findings.
That is, the present invention provides the following inventions.
[1] A polyolefin-based composition comprising the following components (a) to (c).
(A) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. Olefin polymer (A) whose melting point (Tm-D) defined as the observed peak top exceeds 120 ° C
(B) Using a differential scanning calorimeter (DSC), the sample was held at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then heated at 10 ° C./min. Olefin polymer (B) having a calorific value (ΔH-D) of 0 to 80 J / g and a molecular weight distribution (Mw / Mn) of less than 3.0
(C) Nucleating agent (C)
[2] The content of the olefin polymer (B) is 0.5% by mass or more and less than 50% by mass with respect to 100% by mass of the total amount of the components (a) and (b). 1]. The polyolefin-based composition according to 1].
[3] The above [1], wherein the content of the nucleating agent (C) is 0.01 to 2 parts by mass when the total of the component (a) and the component (b) is 100 parts by mass. Or the polyolefin-type composition as described in [2].
[4] The nucleating agent (C) is an organic carboxylic acid or a metal salt thereof, an aromatic sulfonate or a metal salt thereof, an organic phosphate compound or a metal salt thereof, dibenzylidene sorbitol or a derivative thereof, or a rosin acid partial metal salt One or more types selected from inorganic fine particles, imides, amides, quinacridones or quinones, the polyolefin-based composition according to any one of the above [1] to [3].
[5] The polyolefin composition according to any one of [1] to [4], wherein the olefin polymer (A) is a propylene polymer (a1).
[6] Any of the above [1] to [5], wherein the olefin polymer (B) is a propylene polymer (b1) in which 50 mol% or more of monomers constituting the polymer are propylene monomers. The polyolefin-type composition as described in above.
[7] The polyolefin composition according to [6], wherein the propylene polymer (b1) satisfies at least one of the following (i) and (ii).
(I) The structural unit of ethylene is contained in excess of 0 mol% and 20 mol% or less.
(Ii) The structural unit of 1-butene is contained in an amount exceeding 0 mol% and not more than 30 mol%.
[8] The polyolefin composition according to [6], wherein the propylene polymer (b1) satisfies the following (1).
(1) [mmmm] is 20 to 60 mol%
[9] The polyolefin composition according to any one of [6] to [8], wherein the propylene polymer (b1) satisfies the following (2).
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. The melting point (Tm-D) defined as the observed peak top is 0 to 120 ° C. [10] In the above [8], the propylene polymer (b1) satisfies the following (2) and (3): The polyolefin-based composition as described.
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. The melting point (Tm-D) defined as the observed peak top is 0-120 ° C.
(3) [rrrr] / (1- [mmmm]) ≦ 0.1
[11] The polyolefin composition according to any one of [8] or [10], wherein the propylene polymer (b1) satisfies the following (4) and (5).
(4) [rmrm]> 2.5 mol%
(5) [mm] × [rr] / [mr] ² ≦ 2.0
[12] The polyolefin composition according to any one of [1] to [11], wherein the polyolefin composition is a polyolefin composition for extrusion molding.
[13] A molded body comprising the polyolefin-based composition according to any one of [1] to [12].
[14] A film comprising the polyolefin composition according to any one of [1] to [12].
[15] A stretched film comprising the polyolefin composition according to any one of [1] to [12] and oriented in at least one direction.
[16] A multilayer film comprising two or more layers, comprising at least one polyolefin-based composition according to any one of [1] to [12].
[17] A stretched multilayer film which is a multilayer film composed of two or more layers, wherein at least one layer contains the polyolefin-based composition according to any one of the above [1] to [12] and is oriented in at least one direction.
[18] A method for producing a stretched film obtained by heating a film comprising the polyolefin composition according to any one of [1] to [12] above and simultaneously or sequentially stretching in a uniaxial or biaxial direction.
[19] A multilayer film comprising one or more layers composed of the polyolefin composition according to any one of the above [1] to [12] and having two or more layers is heated to simultaneously and uniaxially or biaxially. Alternatively, a method for producing a stretched multilayer film obtained by successive stretching.
[20] A packaging material containing the polyolefin composition according to any one of [1] to [12].
[21] A packaging material comprising the molded article according to [13].

According to the present invention, compared with the conventional olefin-based composition, even if a nucleating agent is added, the polyolefin-based composition can be stretched in a lower temperature region and has excellent mechanical and optical properties after stretching. Things can be provided.
Moreover, the stretched film obtained from this polyolefin-type composition is excellent in an optical characteristic (for example, haze, gloss) and a mechanical characteristic (for example, elastic modulus).

  The present invention is described below. In addition, in this specification, the term "-" regarding description of a numerical value is a term which shows more than the lower limit and below an upper limit. Moreover, in this specification, (a) component and an olefin polymer (A) and (b) component and an olefin polymer (B) are synonymous.

[Polyolefin composition]
The polyolefin-based composition for stretched film of the present invention is (a) using a differential scanning calorimeter (DSC), holding the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raising the temperature at 10 ° C./min. An olefin polymer (A) having a melting point (Tm-D) defined as the peak top observed on the highest temperature side of the melting endothermic curve obtained by (1) exceeding 120 ° C., and (b) a differential scanning calorimeter ( DSC), the sample was held at −10 ° C. for 5 minutes under a nitrogen atmosphere and then heated at 10 ° C./min, and the melting endotherm (ΔH−D) obtained from the melting endotherm curve was 0 to 0 The olefin polymer (B) having a molecular weight distribution (Mw / Mn) of less than 3.0 and (c) a nucleating agent.

The polyolefin composition of the present invention is preferably 0.5% by mass with respect to 100% by mass of the total amount of the (b) component of the polyolefin composition and the (a) and (b) components. Or more, less than 50% by mass, more preferably 0.5% by mass or more and less than 20% by mass, still more preferably 0.5% by mass or more and less than 15% by mass, and still more preferably 1% by mass or more and 10% by mass. %.
Hereafter, each component used for this invention and a manufacturing method are demonstrated one by one.

<Olefin polymer (A)>
The olefin polymer (A), which is the component (a) used in the present invention, was held at −10 ° C. for 5 minutes in a nitrogen atmosphere using a differential scanning calorimeter (DSC), and then 10 ° C./min. The melting point (Tm-D) defined as the peak top that is observed on the highest temperature side of the melting endothermic curve obtained by raising the temperature at 150 ° C. exceeds 120 ° C. When the melting point (Tm-D) is 120 ° C. or lower, there arises a problem that the heat resistance of a molded body using the polyolefin-based composition, for example, a film is inferior. From such a viewpoint, the melting point (Tm-D) is preferably 125 ° C. or higher, more preferably 140 ° C. or higher, still more preferably 150 ° C. or higher, and still more preferably 160 ° C. or higher.
In addition, this melting | fusing point (Tm-D) is a value measured by the method as described in the Example mentioned later.

The olefin polymer (A) of the present embodiment is preferably an olefin polymer obtained by polymerizing one or more monomers selected from, for example, ethylene and an α-olefin having 3 to 28 carbon atoms.
Examples of the α-olefin having 3 to 28 carbon atoms include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene and 1- Examples include dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene and 1-icocene. Among these, Preferably it is C3-C24 alpha-olefin, More preferably, it is C3-C12 alpha-olefin, More preferably, it is C3-C6 alpha-olefin, Most preferably, it is C3-C4 An α-olefin, most preferably propylene.
An olefin polymer obtained by polymerizing one of these alone may be used, or an olefin copolymer obtained by copolymerizing two or more of them may be used. In the present specification, the term “olefin polymer” includes an olefin copolymer. Examples of the olefin copolymer include an ethylene polymer in which 50 mol% or more of the monomers constituting the polymer are ethylene monomers, and a propylene polymer in which 50 mol% or more of the monomers constituting the polymer are propylene monomers ( a1), a butene-based polymer in which 50 mol% or more of the monomers constituting the polymer are butene monomers, and the like, and a molded article having excellent properties from the viewpoint of rigidity and transparency, for example, film properties can be obtained. The polymer (a1) is more preferable. Further, the propylene polymer (a1) has a mesopentad fraction [mmmm] described later of preferably 70 to 98 mol%, more preferably 80 to 98 mol%, and still more preferably, from the viewpoint of improving rigidity and transparency. It is 85-97.5 mol%, More preferably, it is 87-97 mol%, More preferably, it is 88-96 mol%, More preferably, it is 90-92 mol%.
As propylene polymer (a1), propylene homopolymer, propylene-ethylene block copolymer, propylene-butene block copolymer, propylene-α-olefin block copolymer, propylene-ethylene random copolymer, propylene A propylene-based polymer (a1) selected from a -butene random copolymer, a propylene-α-olefin random copolymer, a propylene-α-olefin graft copolymer, and the like is preferable. Furthermore, the olefin polymer (a1) of the present invention is particularly preferably a propylene-ethylene random copolymer or propylene from the viewpoint of the physical properties of the molded body, for example, the physical properties of the stretched film (for example, mechanical physical properties, optical physical properties). It is a homopolymer. The polymer may be a polymer using a petroleum / coal-derived monomer or a polymer using a biomass-derived monomer.

  As content of the olefin polymer (A) in a polyolefin-type composition, it is 50 with respect to the total content of 100 mass% of the olefin polymer (B) mentioned later and the said olefin polymer (A). It is at least mass%. When the said content is less than 50 mass%, the malfunction that the heat resistance of the molded object using this polyolefin-type composition, for example, a stretched film, will generate | occur | produce. From such a viewpoint, the content of the olefin polymer (A) in the polyolefin composition is 100 total content of the olefin polymer (B) and the olefin polymer (A) described later. Preferably it is 80 mass% or more with respect to the mass%, More preferably, it is 85 mass% or more, More preferably, it is 90 mass% or more. Moreover, from the viewpoint of transparency and heat resistance of a stretched film using the polyolefin-based composition, it is preferably 98% by mass or less, more preferably 95% by mass or less.

<Olefin polymer (B)>
The olefin polymer (B), which is the component (b) used in the present invention, was held at −10 ° C. for 5 minutes in a nitrogen atmosphere using a differential scanning calorimeter (DSC), then 10 ° C./min. The melting endotherm (ΔH-D) obtained from the melting endotherm curve obtained by raising the temperature at 0 to 0-80 J / g, and the molecular weight distribution (Mw / Mn) is less than 3.0.
The olefin polymer (B) of the present invention is preferably an olefin polymer (B) obtained by polymerizing one or more monomers selected from ethylene and an α-olefin having 3 to 28 carbon atoms.
Examples of the α-olefin having 3 to 28 carbon atoms include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene and 1- Examples include dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene and 1-icocene. Among these, Preferably it is C3-C24 alpha-olefin, More preferably, it is C3-C12 alpha-olefin, More preferably, it is C3-C6 alpha-olefin, Most preferably, it is C3-C4 An α-olefin, most preferably propylene.
An olefin polymer (B) obtained by polymerizing one of these alone may be used, or an olefin copolymer (B) obtained by copolymerizing two or more in combination. Also good. As the olefin copolymer (B), an ethylene polymer in which 50 mol% or more of the monomers constituting the polymer is an ethylene monomer, or a propylene polymer in which 50 mol% or more of the monomers constituting the polymer is a propylene monomer Examples include polymer (b1), butene-based polymers in which 50 mol% or more of monomers constituting the polymer are butene monomers, and excellent molded article physical properties such as film physical properties from the viewpoint of transparency and suppression of stretching unevenness. The propylene-based polymer (b1) from which can be obtained is more preferable.
As propylene polymer (b1), propylene homopolymer, propylene-ethylene block copolymer, propylene-butene block copolymer, propylene-α-olefin block copolymer, propylene-ethylene random copolymer, propylene It is preferably a propylene polymer (b1) selected from a butene random copolymer, a propylene-α-olefin random copolymer, a propylene-α-olefin graft copolymer, and the like, and in particular, a propylene homopolymer Is preferred.

  Moreover, in the polyolefin-type composition of this invention, when the olefin polymer (A) which is a main component is a propylene-type polymer (a1), a compatible viewpoint with the main component propylene-type polymer (a1). In the case where the propylene polymer (b1) is a copolymer containing an olefin having 2 carbon atoms, the constituent unit of the olefin having 2 carbons (that is, ethylene monomer) is preferably 0 mol%. More than 20 mol%, more preferably more than 0 mol%, less than 18 mol%, still more preferably more than 0 mol%, less than 15 mol%, still more preferably more than 0 mol% and less than 13 mol% It is. In the case of a copolymer containing an olefin having 3 carbon atoms, the constituent unit of the olefin having 3 carbon atoms (that is, propylene monomer) is preferably 50 mol% or more, more preferably 65 mol% or more. More preferably, it is 75 mol% or more, and still more preferably 80 mol% or more. In the case of a copolymer containing an α-olefin having 4 or more carbon atoms, the content of the α-olefin having 4 or more carbon atoms is preferably more than 0 mol% and 30 mol% or less, more preferably 0. More than mol% and 27 mol% or less, more preferably more than 0 mol% and 20 mol% or less.

The propylene polymer (b1) more preferably satisfies at least one of the following (i) and (ii).
(I) The structural unit of ethylene is contained in excess of 0 mol% and 20 mol% or less.
(Ii) The structural unit of 1-butene is contained in an amount exceeding 0 mol% and not more than 30 mol%.

  Moreover, in the polyolefin-type composition of this invention, when the olefin polymer (A) which is a main component is a propylene-type polymer (a1), a compatible viewpoint with the main component propylene-type polymer (a1). From the above, the olefin polymer (B) of the present invention is most preferably a propylene homopolymer. The polymer may be a polymer using a petroleum / coal-derived monomer or a polymer using a biomass-derived monomer.

Since the polyolefin-based composition of the present invention contains the olefin-based polymer (B), the ratio of the amorphous component is increased, and the yield stress when the polyolefin-based composition is stretched is reduced. The stretchability is improved, and the tenacity of the formed body, for example, the formed film is improved.
In particular, from the viewpoint of greatly improving the stretchability of the polyolefin-based composition in the low temperature region, the content of the olefin-based polymer (B) is increased in order to increase the proportion of the amorphous component in the polyolefin-based composition. The total content of the olefin polymer (B) and the olefin polymer (A) is preferably 100% by mass or more and less than 50% by mass, more preferably 0%. It is 0.5 mass% or more and less than 20 mass%, More preferably, it is 0.5 mass% or more and less than 15 mass%, More preferably, it is 1 mass% or more and less than 10 mass%.
In particular, when the olefin polymer (A) is a propylene polymer (a1) and the olefin polymer (B) is a propylene polymer (b1), the propylene polymer. The compatibility of the propylene-based polymer (b1) with respect to (a1) becomes better, and a molded product having more excellent transparency and stretchability can be obtained.

  The olefin polymer (B) has the following melting endotherm (ΔH-D) and molecular weight distribution (Mw / Mn) from the viewpoint of greatly improving stretchability without affecting the mechanical properties of the molded body. And having the characteristics described later (particularly, in the case of the propylene polymer (b1)), the content of the olefin polymer (B) is in the above-described range. preferable.

(Melting endotherm (ΔH-D))
The melting endotherm (ΔH-D) of the olefin polymer (B) and the propylene polymer (b1) is 0 to 80 J / g. When the melting endotherm (ΔH-D) of the olefin polymer (B) and the propylene polymer (b1) is 0 to 80 J / g, it is a main component of the polyolefin composition suitable for the stretched film of the present invention. The crystallinity is reduced with respect to a certain olefin polymer (A) (particularly when the olefin polymer (A) is a propylene polymer (a1)). Thereby, the number of tie molecules between lamellae and lamellae is reduced. When the number of tie molecules is small during stretching, the initial higher-order structure is uniformly deformed, and as a result, uniform stretchability is improved. From such a viewpoint, the melting endotherm (ΔH-D) is preferably 10 to 70 J / g, more preferably 20 to 60 J / g, and still more preferably 30 to 50 J / g.
The melting endotherm (ΔH−D) can be controlled by appropriately adjusting the monomer concentration and reaction pressure.
The melting endotherm (ΔH-D) is a melting endotherm curve obtained by DSC measurement with a line connecting a point on the low temperature side where there is no change in calorie and a point on the high temperature side where there is no change in calorie as a baseline. It is calculated by obtaining the area surrounded by the line portion including the peak and the base line.

(Molecular weight distribution (Mw / Mn))
The molecular weight distribution (Mw / Mn) of the olefin polymer (B) and the propylene polymer (b1) is preferably less than 3.0 from the viewpoint of high strength. If the molecular weight distribution (Mw / Mn) is less than 3.0, low molecular weight components that adversely affect stretchability and molded article physical properties, such as film physical properties (for example, mechanical properties and optical properties), are suppressed. The physical properties of the molded article of the invention, particularly the deterioration of the film physical properties of the stretched film, is suppressed. From such a viewpoint, the molecular weight distribution (Mw / Mn) of the olefin polymer (B) and the propylene polymer (b1) is preferably 2.5 or less, more preferably 1.5 to 2.5. .
In the present invention, the molecular weight distribution (Mw / Mn) is a value calculated from the polystyrene-equivalent weight average molecular weight Mw and number average molecular weight Mn measured by gel permeation chromatography (GPC).

The olefin polymer (B) and the propylene polymer (b1) of the present invention are preferably propylene polymers satisfying either one of the following (1) or (2) or both, and more preferably Satisfies the following (3), more preferably satisfies the following (4) and (5).
(1) [mmmm] is 20 to 60 mol%.
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. The melting point (Tm-D) defined as the observed peak top is 0-120 ° C.
(3) [rrrr] / (1- [mmmm]) ≦ 0.1
(4) [rmrm]> 2.5 mol%
(5) [mm] × [rr] / [mr] ² ≦ 2.0

(1) Mesopentad fraction [mmmm]
The mesopentad fraction [mmmm] is an index representing the stereoregularity of the olefin polymer (B) and the propylene polymer, and the stereoregularity increases as the mesopentad fraction [mmmm] increases.
When the olefin polymer (B) is a propylene homopolymer, the mesopentad fraction [mmmm] is improved in handling properties of the propylene polymer and stretchability when added in a small amount to the olefin polymer (A). From a viewpoint of an effect, Preferably it is 20-60 mol%, More preferably, it is 30-55 mol%, More preferably, it is 40-50 mol%. When the mesopentad fraction [mmmm] is 20 mol% or more, the stretchability can be improved without reducing the rigidity of the olefin polymer (A), which is the main component of the polyolefin composition of the present invention. If it is 60 mol% or less, it is not eutectic with the main component olefin polymer (A), and is compatible with the amorphous part of the main component olefin polymer (A) to be extensible. Can be improved.

(2) Melting point (Tm-D)
The melting point (Tm-D) of the olefin polymer (B) and the propylene polymer (b1) is preferably higher from the viewpoint of strength and moldability. Preferably it is 0-120 degreeC, More preferably, it is 50-100 degreeC, More preferably, it is 55-90 degreeC, More preferably, it is 60-80 degreeC.
In the present invention, a differential scanning calorimeter (DSC-7, manufactured by Perkin Elmer Co., Ltd.) is used, and 10 mg of a sample is held at −10 ° C. for 5 minutes in a nitrogen atmosphere and then heated at 10 ° C./min. The peak top of the peak observed on the highest temperature side of the melting endothermic curve obtained by the above is defined as the melting point (Tm-D). The melting point can be controlled by appropriately adjusting the monomer concentration and reaction pressure.

(3) [rrrr] / (1- [mmmm])
The value of [rrrr] / (1- [mmmm]) is obtained from the mesopentad fraction [mmmm] and the racemic pentad fraction [rrrr] and is an index indicating the uniformity of the regularity distribution of polypropylene. When this value of [rrrr] / (1- [mmmm]) is increased, it becomes a mixture of highly stereoregular polypropylene and atactic polypropylene like conventional polypropylene produced using an existing catalyst system, and the polypropylene is stretched after molding. It causes stickiness of the film. The unit of [rrrr] and [mmmm] in the above is mol%.
From the standpoint of stickiness, the value of [rrrr] / (1- [mmmm]) in the olefin polymer (B) and the propylene polymer (b1) is preferably 0.1 or less, more preferably 0.8. 001 to 0.05, more preferably 0.001 to 0.04, and particularly preferably 0.01 to 0.04.

Here, the mesopentad fraction [mmmm], the racemic pentad fraction [rrrr], and the racemic meso racemic meso pendad fraction [rmrm], which will be described later, are determined by A. Zambelli et al. According to “Macromolecules, 6, 925 (1973) ”, and meso fraction, racemic fraction, and racemic meso-racemic meso in pentad units in the polypropylene molecular chain measured by the methyl group signal of the ¹³ C-NMR spectrum. It is a fraction. As the mesopentad fraction [mmmm] increases, the stereoregularity increases. Further, triad fractions [mm], [rr] and [mr] described later are also calculated by the above method.

(4) Racemic meso racemic meso pentad fraction [rmrm]
The racemic meso racemic meso pentad fraction [rmrm] is an index representing the randomness of the stereoregularity of polypropylene, and the randomness of polypropylene increases as the value increases.
The racemic meso racemic meso pentad fraction [rmrm] of the olefin polymer (B) and the propylene polymer (b1) is preferably more than 2.5 mol%. When [rmrm] of the olefin polymer (B) and the propylene polymer (b1) exceeds 2.5 mol%, the randomness increases, and the olefin weight which is the main component of the polyolefin composition of the present invention. Copolymerization (A) (especially when the olefin polymer (A) is a propylene polymer (a1)) becomes difficult to eutectify, and as a result, a decrease in heat resistance and rigidity of the polyolefin composition is suppressed. The From such a viewpoint, the racemic meso racemic meso pentad fraction [rmrm] of the olefin polymer (B) and the propylene polymer (b1) is more preferably 2.6 mol% or more, and still more preferably 2. 7 mol% or more. The upper limit is usually preferably about 10 mol%, more preferably 7 mol%, still more preferably 5 mol%, and particularly preferably 4 mol%.

(5) [mm] × [rr] / [mr] ²
The value of [mm] × [rr] / [mr] ² calculated from the triad fraction [mm], [rr] and [mr] represents an index of randomness of the polymer. The olefin polymer (A) which is the main component of the polyolefin composition of the present invention (especially when the olefin polymer (A) is a propylene polymer (a1)) and eutectic crystallized. It does not occur, and the stretchability can be improved efficiently with respect to the main component olefin polymer (A) (particularly propylene polymer (a1)). In the olefin polymer (B) and the propylene polymer (b1) of the present invention, the value of the above formula is usually 2 or less, preferably 1.8 to 0.5, more preferably 1.5 to 0.5. It is a range. In addition, the unit of [mm] and [rr] in the above is mol%.

The propylene polymer (b1) can be produced, for example, using a metallocene catalyst as described in WO2003 / 087172. In particular, those using a transition metal compound in which a ligand forms a cross-linked structure via a cross-linking group are preferred, and in particular, a transition metal compound that forms a cross-linked structure via two cross-linking groups and Metallocene catalysts obtained by combining promoters are preferred.
For example,
(I) General formula (I)

[In the formula, M represents a group 3-10 of the periodic table or a lanthanoid series metal element, and E ¹ and E ² represent a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a heterocyclopentadienyl group, respectively. A ligand selected from a substituted heterocyclopentadienyl group, an amide group, a phosphide group, a hydrocarbon group, and a silicon-containing group, which forms a cross-linked structure via A ¹ and A ² In addition, they may be the same or different from each other, X represents a σ-bonded ligand, and when there are a plurality of X, the plurality of X may be the same or different, and other X, E ¹ , E ² or Y may be cross-linked. Y represents a Lewis base, and when there are a plurality of Y, the plurality of Y may be the same or different, and may be cross-linked with other Y, E ¹ , E ² or X, and A ¹ and A ² are A divalent bridging group that binds two ligands, a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, a germanium-containing group, a tin-containing group _{, -O -, - CO -,} - S -, - SO 2 -, - Se -, - NR 1 -, - PR 1 -, - P (O) R 1 -, - BR 1 - or -AlR ¹ - R ¹ represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, which may be the same as or different from each other. q represents an integer of 1 to 5 and represents [(M valence) -2], and r represents an integer of 0 to 3. ]
And (ii) (ii-1) a compound capable of reacting with the transition metal compound of component (i) or a derivative thereof to form an ionic complex, and (ii-2) aluminoxane And a polymerization catalyst containing a component selected from:

  As the transition metal compound (i), a ligand is preferably a (1,2 ′) (2,1 ′) double-bridged transition metal compound, such as (1,2′-dimethylsilylene) ( 2,1'-dimethylsilylene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride.

  Specific examples of the compound of component (ii-1) include triethylammonium tetraphenylborate, tri-n-butylammonium tetraphenylborate, trimethylammonium tetraphenylborate, tetraethylammonium tetraphenylborate, methyl tetraphenylborate (tri- n-butyl) ammonium, benzyl tetraphenylborate (tri-n-butyl) ammonium, dimethyldiphenylammonium tetraphenylborate, triphenyl (methyl) ammonium tetraphenylborate, trimethylanilinium tetraphenylborate, methylpyridinium tetraphenylborate, tetra Benzylpyridinium phenylborate, methyl tetraphenylborate (2-cyanopyridinium), trikis (tetrafluorophenyl) borate triethyla Monium, tetrakis (pentafluorophenyl) tri-n-butylammonium borate, tetrakis (pentafluorophenyl) triphenylammonium borate, tetrakis (pentafluorophenyl) tetra-n-butylammonium borate, tetraethylammonium tetrakis (pentafluorophenyl) borate Benzyl tetrakis (pentafluorophenyl) ammonium borate (tri-n-butyl), methyldiphenylammonium tetrakis (pentafluorophenyl) borate, triphenyl (methyl) ammonium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) boric acid Methylanilinium, tetrakis (pentafluorophenyl) borate dimethylanilinium, tetrakis (pentafluoropheny L) Trimethylanilinium borate, methyl pyridinium tetrakis (pentafluorophenyl) borate, benzyl pyridinium tetrakis (pentafluorophenyl) borate, methyl tetrakis (pentafluorophenyl) borate (2-cyanopyridinium), benzyl tetrakis (pentafluorophenyl) borate (2-cyanopyridinium), methyl tetrakis (pentafluorophenyl) borate (4-cyanopyridinium), triphenylphosphonium tetrakis (pentafluorophenyl) borate, tetrakis [bis (3,5-ditrifluoromethyl) phenyl] dimethylaniline borate Ferrocenium tetraphenylborate, silver tetraphenylborate, trityl tetraphenylborate, tetraphenylporphyrin manganese tetraphenylborate, Trakis (pentafluorophenyl) borate ferrocenium, tetrakis (pentafluorophenyl) borate (1,1′-dimethylferrocenium), tetrakis (pentafluorophenyl) decamethylferrocenium borate, tetrakis (pentafluorophenyl) silver borate, Tetrakis (pentafluorophenyl) triborate borate, tetrakis (pentafluorophenyl) lithium borate, tetrakis (pentafluorophenyl) sodium borate, tetrakis (pentafluorophenyl) borate Teolaphenylporphyrin manganese, silver tetrafluoroborate, silver hexafluorophosphate, hexa Examples thereof include silver fluoroarsenate, silver perchlorate, silver trifluoroacetate, and silver trifluoromethanesulfonate.

  Examples of the aluminoxane as the component (ii-2) include known chain aluminoxanes and cyclic aluminoxanes.

  Also, trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, dimethylaluminum fluoride, diisobutylaluminum hydride, diethylaluminum hydride, ethylaluminum sesquichloride, etc. The propylene-based polymer (b1) may be produced using a combination of these organoaluminum compounds.

(Weight average molecular weight distribution (Mw))
The weight molecular weight distribution (Mw) of the olefin polymer (B) and the propylene polymer (b1) is preferably 10,000 or more and 500,000 or less from the viewpoint of strength.
When the weight average molecular weight is 10,000 or more and 500,000 or less in the olefin polymer (B) and the propylene polymer (b1), the olefin polymer (B) and the propylene polymer (b1) The stretchability is improved and the film strength is excellent. The weight average molecular weight is preferably 30,000 or more and 400,000 or less, more preferably 50,000 or more and 300,000 or less.
In the present invention, the weight molecular weight (Mw) is a value calculated from a weight average molecular weight Mw in terms of polystyrene and a number average molecular weight Mn measured by a gel permeation chromatography (GPC) method.

<Nucleating agent (C)>
In general, crystallization of a propylene-based polymer consists of two processes, a crystal nucleation process and a crystal growth process. In the crystal nucleation process, the temperature difference from the crystallization temperature, the state of molecular chain orientation, etc. It is said to affect the generation rate. In particular, it is known that the rate of crystal nucleation is significantly increased when a substance having an effect of promoting molecular chain orientation exists through molecular chain adsorption or the like. As the nucleating agent in the present invention, any nucleating agent may be used as long as it has an effect of improving the progress of the crystal nucleation process. Substances that have the effect of improving the progress rate of the crystal nucleation process include substances that have the effect of promoting molecular chain orientation through the process of adsorbing molecular chains of polymers.

  Specific examples of the nucleating agent in the present invention include an organic carboxylic acid or a metal salt thereof, an aromatic sulfonate or a metal salt thereof, an organic phosphate compound or a metal salt thereof, dibenzylidene sorbitol or a derivative thereof, a rosin acid partial metal Examples thereof include salts, inorganic fine particles, imides, amides, quinacridones, quinones, and mixtures thereof.

  Examples of the metal salt of the organic carboxylic acid include aluminum benzoate, aluminum pt-butylbenzoate, sodium adipate, sodium thiophenecarboxylate, and sodium pyrolecarboxylate.

  Dibenzylidene sorbitol or derivatives thereof include dibenzylidene sorbitol, 1,3: 2,4-bis (o-3,4-dimethylbenzylidene) sorbitol, 1,3: 2,4-bis (o-2,4- Dimethylbenzylidene) sorbitol, 1,3: 2,4-bis (o-4-ethylbenzylidene) sorbitol, 1,3: 2,4-bis (o-4-chlorobenzylidene) sorbitol, 1,3: 2,4 -Dibenzylidene sorbitol etc. are mentioned. Specific examples include “Gelall MD” and “Gelall MD-R” (trade name) manufactured by Shin Nippon Rika Co., Ltd.

  Examples of the rosin acid partial metal salt include “Pine Crystal KM1600”, “Pine Crystal KM1500”, “Pine Crystal KM1300” (trade name) manufactured by Arakawa Chemical Industries, Ltd., and the like.

  Inorganic fine particles include talc, clay, mica, asbestos, glass fiber, glass flakes, glass beads, calcium silicate, montmorillonite, bentonite, graphite, aluminum powder, alumina, silica, diatomaceous earth, titanium oxide, magnesium oxide, pumice stone Examples thereof include powder, pumice balloon, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dolomite, calcium sulfate, potassium titanate, barium sulfate, calcium sulfite, and molybdenum sulfide.

  Examples of the amide compound include adipic acid dianilide, speric acid dianilide and the like. One type of these nucleating agents may be used, or two or more types may be used in combination.

  In the olefin-based composition of the present invention, it is preferable to use inorganic fine particles such as an organic phosphate metal salt and / or talc represented by the following general formula as a nucleating agent from the viewpoint of less generation of odor. Olefin-based compositions or propylene-based resin compositions using such nucleating agents are suitable for food applications.

(In the formula, R ¹⁸ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ¹⁹ and R ²⁰ each represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group. M represents any one of alkali metal, alkaline earth metal, aluminum and zinc, m represents 0 when M is an alkali metal, n represents 1, and M represents an alkaline earth metal or zinc n is 1 or 2, m is 1 when n is 1, m is 0 when n is 2, m is 1 when M is aluminum, and n is 2.)
Specific examples of the organic phosphate metal salt include “ADK STAB NA-11” and “ADK STAB NA-21” (both manufactured by Asahi Denka Co., Ltd.).

Furthermore, as the olefin-based resin composition of the present invention, it is preferable to use inorganic fine particles such as talc as a nucleating agent because, when formed into a film, it is excellent in slip properties and properties such as printing properties are improved. . Furthermore, it is preferable to use the dibenzylidene sorbitol or a derivative thereof as a nucleating agent because of excellent transparency. Furthermore, it is preferable to use the amide compound as a nucleating agent because it is excellent in rigidity. As the dibenzylidene sorbitol nucleating agent, the trade name “Millad” (NX8000) manufactured by Milliken Chemical Co., Ltd. and the trade name “Clear master” (PP-RM-NSA RMX50, master batch, concentration manufactured by Dainichi Seika Kogyo Co., Ltd., concentration: 20% by weight) can be used.
The blending amount of the nucleating agent in the present invention is blended in the range of 0.01 to 4 parts by mass when the total of the component (a) and the component (b) is 100 parts by mass from the viewpoint of rigidity and stretchability. More preferably, it is more preferable that it is 0.01-3 mass parts, and it is still more preferable that it is 0.01-2 mass parts.

<Additives>
A polyolefin-based composition suitable for the stretched film of the present invention is an antioxidant, a heat-resistant stabilizer, a weather-resistant stabilizer, an antistatic agent, a slip agent, if necessary, as long as the object of the present invention is not impaired. Antifogging agents, lubricants, antiblocking agents, dyes, pigments, natural oils, synthetic oils, waxes, fillers, elastomers and the like can be blended.
As the antioxidant, a hindered phenol-based, sulfur-based, lactone-based, organic phosphite-based, organic phosphonite-based antioxidant, or an antioxidant obtained by combining several of these can be used. The antioxidant is preferably blended in the range of 0.01 to 5% by mass with respect to 100% by mass of the total amount of the polyolefin-based composition.
As the antistatic agent, known low molecular type or high molecular type antistatic agents that are generally used can be suitably used.
Examples of the low molecular weight antistatic agent include nonionic antistatic agents such as alkyldiethanolamine, polyoxyethylene alkylamide, monoglycerin fatty acid ester, diglycerin fatty acid ester, sorbitan fatty acid ester, and tetraalkylammonium salt type cationic type. Antistatic agents such as antistatic agents, anionic antistatic agents such as alkylsulfonates, and amphoteric antistatic agents such as alkylbetaines.
Examples of polymer antistatic agents include nonionic antistatic agents such as polyetheresteramide, anionic antistatic agents such as polystyrene sulfonic acid, and cationic antistatic agents such as quaternary ammonium salt-containing polymers. Etc.
The antistatic agent is preferably blended in the range of 0.01 to 5% by mass with respect to 100% by mass of the total amount of the polyolefin-based composition.
As the slip agent, amides of saturated or unsaturated fatty acids such as lauric acid, palmitic acid, oleic acid, stearic acid, erucic acid and hebenic acid, or bisamides of these saturated or unsaturated fatty acids can be used. Of these, erucic acid amide and ethylenebisstearic acid amide are preferable. The slip agent is preferably blended in the range of 0.01 to 5% by mass with respect to 100% by mass of the total amount of the polyolefin-based composition.
Antiblocking agents include finely divided silica, finely divided aluminum oxide, finely divided clay, powdered or liquid silicone resin, polytetrafluoroethylene resin, finely crosslinked resin such as crosslinked acrylic resin or methacrylic resin powder Can be mentioned. Of these, finely divided silica and finely powdered crosslinked resin are preferred. It is preferable to mix | blend an antiblocking agent in 0.01-5 mass% with respect to 100 mass% of whole quantity of the said polyolefin-type composition.
As the elastomer, styrene-based, olefin-based, ester-based, soft vinyl chloride-based, urethane-based, amide-based, butadiene-isoprene-based elastomers, or an elastomer obtained by combining several of these can be used. Of these, styrene, olefin, and butadiene / isoprene are preferred. The elastomer is preferably blended in the range of 1 to 20% by mass with respect to 100% by mass of the total amount of the polyolefin-based composition.

<Manufacture of polyolefin-based composition>
The polyolefin-based composition of the present invention is prepared by adding the above components (a), (b), and (c), and additives as necessary, for example, a high-speed mixer, a Banbury mixer, a continuous kneader, a uniaxial or In general, a method of granulating by heat melting and kneading using a normal mixing and kneading machine such as a twin screw extruder, a roll, or a Brabender plastograph is employed. The component (c) may be masterbatched in advance before mixing the component (a) and the component (b).
The polyolefin-based composition of the present invention is preferably used for extrusion molding. Further, the above components (a), (b), and (c) may be used immediately before extrusion molding, for example, simultaneously put into a hopper on an extruder (dry blend), and in that case (c) About a component, you may use what was masterbatched beforehand.

[Molded body]
The molded object of this invention is a molded object which consists of said polyolefin type composition.
The polyolefin-based composition can be used in an injection molding method in which a mold is filled from an extruder, but is preferably used in a molding method having a stretching process. For example, a beneficial effect can be expected when used for blow molding including extrusion blow molding or injection blow molding, or thermoforming, or film molding described later.
For example, the blow molded article can be produced by blow molding the polyolefin-based composition of the present invention using a known blow molding apparatus under known conditions. That is, the polyolefin-based composition of the present invention is heated and melted in an extruder and extruded into a tube shape. After being sandwiched in a mold carved only on the outside of the product, air is drawn into (injected into) the tube. Can be used in a molding method in which a hollow body is formed by inflating a shaped body along a mold wall surface. Even if the polyolefin-based composition of the present invention contains a nucleating agent (C), it is excellent in stretchability, maintained in elongation at break, has little unevenness (variation) in the thickness of the molded hollow body bottle, and is uniform. Therefore, an increase in quality unevenness of the mechanical properties (for example, strength) of the bottle is also suppressed, and transparency is improved. Therefore, for example, when a propylene polymer is used as the polyolefin composition, it can be applied to a polypropylene injection stretch blow bottle instead of a polyethylene terephthalate (PET) bottle.
Moreover, the melt-kneaded material of the polyolefin-type composition of this invention can be made into the resin particle of predetermined size, and a foaming molding can be manufactured. For example, a dispersion in which resin particles of a predetermined size made of a melt-kneaded product of the polyolefin composition of the present invention are dispersed in water in a pressure resistant container together with a volatile foaming agent is prepared. The resin particles are heated to a temperature in the range of melting point-20 ° C. to melting point + 20 ° C. of the polyolefin-based composition, and the resin particles are impregnated with a volatile foaming agent. Then, while maintaining the temperature and pressure in the pressure vessel constant by pressurizing the vapor pressure of the volatile foaming agent, the dispersion of the resin particles made of the polyolefin-based composition and water is placed in the pressure vessel. And a method of releasing in a lower pressure atmosphere. By using the polyolefin-based composition of the present invention, the stretchability at the time of foaming is improved, so that a foamed molded article having good surface elongation and good mold transferability can be obtained.
Moreover, the film mentioned later can be manufactured by extrusion-molding the polyolefin-type composition of this invention.

<Film>
The film of the present invention is a film made of the above polyolefin-based composition. The film can be produced, for example, by extruding the film from a known mold (die) under known conditions using the polyolefin composition. For example, it can be obtained by cooling a film comprising the polyolefin-based composition of the present invention obtained by extrusion molding with a chill roll. The film comprising the polyolefin composition of the present invention has good transparency and gloss.
Moreover, the said film is used suitably also for a foam film, a filler compounded film, etc. As a filler mix | blended with the said filler compounded film, well-known fillers, such as a talc, mica, a calcium carbonate, magnesium carbonate, a silica, glass, are employable.
The thickness of the film of the present invention is not particularly limited, but is preferably 1 μm or more, more preferably 2 μm or more, and preferably 1000 μm or less, more preferably 400 μm or less, still more preferably 250 μm or less, and even more preferably 80 μm. It is as follows.
In some cases, when the thickness of the film of the present invention exceeds 250 μm, the film may be referred to as a “sheet”.

<Stretched film>
The stretched film of the present invention is a stretched film including the polyolefin-based composition of the present invention and oriented in at least one direction, preferably a stretched film oriented in a uniaxial or biaxial direction. Preferred examples of the stretched film include a polyethylene stretched film, a polypropylene stretched film, and a polybutene stretched film, but a polypropylene stretched film is more preferred because of having excellent stretched film properties.
In addition, the kind of this stretched film is determined by the kind of the olefin polymer (A) which is a base resin of the stretched film and is also a main component of the polyolefin composition.
The thickness of the stretched film of the present invention is not particularly limited, but is preferably 1 μm or more, more preferably 2 μm or more, and preferably 1000 μm or less, more preferably 400 μm or less, still more preferably 250 μm or less, and even more preferably. It is 80 μm or less, more preferably 50 μm or less.
In some cases, when the thickness of the stretched film of the present invention exceeds 250 μm, the stretched film may be referred to as a “stretched sheet”.

Here, for example, each of a film comprising a nucleating agent and an olefin polymer (A), and a film comprising the nucleating agent, the olefin polymer (A) and the olefin polymer (B) as in the present invention. When observed, the values do not appear in the values of transparency and gloss, and there is a difference in the cleanness of the surface.
This is because when the composition comprising the nucleating agent and the olefin polymer (A) is stretched, the crystal density in the vicinity of the nucleating agent increases, so that the crystal nucleus is forcibly stretched without being completely broken. The For this reason, stress is concentrated at the interface between the nucleating agent and the film during stretching, and as a result, interfacial peeling occurs, thereby generating voids in the film.
On the other hand, in the case of the composition containing the nucleating agent and the olefin polymers (A) and (B), the amorphous region increases, and the dispersibility of the nucleating agent increases, thereby reducing the size of the crystal nucleus. As a result, it is presumed that peeling does not easily occur at the interface between the nucleating agent and the film during stretching, and generation of voids in the film is suppressed.
Therefore, even if the olefin resin composition of the present invention contains a nucleating agent, the stretchability is high, the stretchability is maintained (the process window is maintained), the film surface is less rough when the film is stretched, and the injection is performed. It is expected that the elongation at break is maintained in the molded body.

<Multilayer film>
The multilayer film of the present invention is a multilayer film composed of two or more layers, and at least one layer contains the polyolefin-based composition. The multilayer film can be produced by, for example, extruding from a known mold (die) with a known condition using the polyolefin-based composition. For example, it can be obtained by cooling a multilayer film comprising the polyolefin-based composition of the present invention obtained by extrusion molding with a chill roll.
The thickness of the multilayer film of the present invention is not particularly limited, but is preferably 1 μm or more, more preferably 2 μm or more, and preferably 1000 μm or less, more preferably 400 μm or less, still more preferably 250 μm or less, and even more preferably. It is 80 μm or less, more preferably 50 μm or less.
In some cases, when the thickness of the multilayer film of the present invention exceeds 250 μm, the multilayer film may be referred to as a “multilayer sheet”.

<Stretched multilayer film>
The stretched multilayer film of the present invention is a stretched multilayer film composed of two or more layers, wherein at least one layer contains the polyolefin-based composition of the present invention, and the layer or the multilayer including the layer is at least in one direction. It is an oriented stretched multilayer film. A stretched multilayer film oriented in a uniaxial or biaxial direction is preferable. Further, in the stretched multilayer film, a layer made of a resin composition that functions as a sealant layer and a skin layer may be laminated on a layer adjacent to the layer made of the polyolefin-based composition. Moreover, when the layer which consists of the said polyolefin-type composition turns into an outermost layer, you may function as a heat seal layer.
When the outermost layer is a heat seal layer, a layer made of the olefin polymer (A) described above is preferable. For example, the olefin polymer (A) is a propylene-ethylene random copolymer, propylene-butene random copolymer. More preferably, it is a coalescence or propylene-α-olefin random copolymer.
In addition, the stretched multilayer film of the present invention can be used by appropriately selecting a resin composition as another layer of the outermost layer and the inner layer depending on the application. For example, in addition to the polyolefin-based composition, a gas barrier can be used. Resin (ethylene-vinyl alcohol copolymer, etc.) having a property, and resin (nylon, etc.) having rigidity.
The layer thickness of the polyolefin-based composition of the stretched multilayer film of the present invention is not particularly limited, but is preferably 1 μm or more, more preferably 2 μm or more, and preferably 1000 μm or less, more preferably 400 μm or less, More preferably, it is 250 micrometers or less, More preferably, it is 80 micrometers or less, More preferably, it is 50 micrometers or less.
In some cases, when the thickness of the stretched multilayer film of the present invention exceeds 250 μm, the stretched multilayer film may be referred to as a “stretched multilayer sheet”.

  In the stretched film of the present invention, the film comprising the polyolefin-based composition, the stretched film, the multilayer film, and the stretched multilayer film when the propylene polymer (b1) is a main component are described later in Examples. In addition, it is superior to conventional polypropylene films, stretched films, multilayer films, and stretched multilayer films that use polypropylene raw materials, and production line speeds can be increased, and the frequency of breakage is reduced compared to conventional methods. In addition, the mechanical properties and optical properties of the obtained films are excellent.

  The total haze value representing the transparency of the film, stretched film, or stretched multilayer film of the present invention is preferably 2.5 or less, more preferably 2.0 or less, and gloss representing optical properties when the thickness is 1 μm to 100 μm. (Gloss) is 130% or more, more preferably 135% or more.

[Method for producing stretched film]
The method for producing a stretched film of the present invention is a method for producing a stretched film by reheating a film containing one or more layers containing the polyolefin-based composition of the present invention and simultaneously or sequentially stretching in a uniaxial or biaxial direction. It is.
Below, an example is demonstrated as a general manufacturing method of the stretched film of this invention. In addition, in this invention, it does not restrict to the following manufacturing methods.
The polyolefin-based composition is melt-extruded and dropped from a T-shaped die in a curtain shape, and immediately after this, the molten film is solidified by a cooling roll to obtain a primary film. Subsequently, stretching is performed by a subsequent stretching apparatus. In addition, the preferable resin temperature at the time of the said melt extrusion is 180-300 degreeC, More preferably, it is 200-280 degreeC. Further, the cooling roll temperature is preferably 0 to 120 ° C, more preferably 10 to 100 ° C.
The primary film obtained by extrusion can be further stretched by uniaxial stretching or biaxial stretching to obtain a stretched stretched film. Examples of the stretching method include a method in which the extruded primary film is continuously subjected to sequential biaxial stretching and simultaneous biaxial stretching by a tenter method, or a method in which simultaneous biaxial stretching is performed by an inflation method. A batch-type biaxial stretching apparatus may be used. Although a draw ratio can be suitably determined according to the use of a stretched film, it is uniaxially stretched or biaxially stretched 2 to 12 times in the machine direction (MD) and / or the direction perpendicular to the machine direction (TD). It is preferable to do.
In general, when sequential biaxial stretching is performed, for example, when the film is first oriented by stretching in the MD direction and then stretched in the TD direction, the stretching ratio in the MD direction is high. If it is too high, it is known that when the draw ratio in the TD direction is increased, a problem that the film is easily broken occurs. When the polyolefin-based composition of the present invention is used, good stretchability can be obtained, so that molding at a high stretch ratio is possible. For example, after setting an appropriate stretching temperature, it is 4 times in the MD direction. As described above, the film can be stretched by 5 times or more, and after stretching in the MD direction, it can be stretched by 9 times or more, and further 9.5 times or more in the TD direction.
In sequential biaxial stretching by the tenter method, first, the primary film is reheated to a temperature suitable for stretching (longitudinal (MD) stretching temperature; preferably 70 to 180 ° C., more preferably 80 to 170 ° C.), Stretching in the machine direction (MD) between a slow roll (front roll) and a fast roll (rear roll). Next, while maintaining both ends of the film stretched in the MD direction in the tenter part, the film is further heated (transverse (TD) stretching temperature; preferably 140 to 175 ° C, more preferably 145 to 170 ° C), and the machine direction Is stretched in the vertical direction (TD). Finally, the film after the stretching treatment is heat treated (heat setting temperature; preferably 140 to 175 ° C., more preferably 145 to 170 ° C.) to stabilize the properties of the stretched film, and the film is wound up by a winder, A desired stretched film can be obtained. The obtained stretched film may be further adjusted to an appropriate width and length with a machine such as a slitter to have a shape according to the purpose. The stretched film of the present invention can also be obtained by using a biaxial simultaneous tenter-type stretching method in which stretching in the machine direction (MD) and the vertical direction (TD) as described above is performed simultaneously.
In addition, from the viewpoint of further improving the transparency of the obtained stretched film, the MD stretching temperature and the TD stretching temperature are preferably low temperature conditions among preferable conditions.

  Further, as the draw ratio, the machine direction (MD) and / or the surface ratio obtained by multiplying the machine direction (TD) by the perpendicular direction (TD) is usually 4 to 50 times, but the polyolefin composition of the present invention. When is used, the stretchability is further improved, so that stretching at a high magnification becomes possible. For example, stretching at a surface magnification of 47 times or more is possible, and furthermore, stretching at a higher magnification is possible than the range of 4 to 50 times, for example, 50.5 times or more, and further 55 times or more. Stretching is possible even at a surface magnification. Thus, even if the film stretched | stretched at high magnification is thick, it is excellent in transparency, and can suppress shrinkage | contraction of the film after extending | stretching.

[Method for producing stretched multilayer film]
Moreover, the manufacturing method similar to the manufacturing method of the said stretched film can be used also about the manufacturing method of the stretched multilayer film of this invention. That is, it contains at least one layer containing the polyolefin-based composition of the present invention, is laminated with a layer made of another resin composition, and the primary film obtained by extrusion is further uniaxially laminated in the same manner as in the method for producing the stretched film. A stretched multilayer film may be obtained by stretching or stretching by biaxial stretching or the like, or the extruded primary film is continuously continuous biaxially or simultaneously biaxially stretched by a tenter method, or It can be produced by performing simultaneous biaxial stretching by an inflation method. In the above-described extrusion process in the case of obtaining a primary film, for example, each layer of resin (or resin composition) is supplied from two or more different extruders, laminated inside a T-shaped die, and co-extruded. By doing so, the primary film can be obtained.

Further, among the stretched films in the present invention, the method for producing a polypropylene stretched film includes the propylene polymer (b1) (particularly, the propylene homopolymer having the above-mentioned melting endotherm (ΔH-D) and having the above-described characteristics. ) Is preferably 0.5% by mass or more and less than 50% by mass, more preferably 0.5% by mass or more and less than 20% by mass, still more preferably 0.5% by mass or more and less than 15% by mass, or more. More preferably, it is a manufacturing method which manufactures at 1 mass% or more and less than 10 mass%.
On the other hand, the propylene-based polymer (b1) (particularly, the propylene homopolymer having the melting endotherm (ΔH-D) and having the above-mentioned characteristics) has a uniform composition and a narrow molecular weight distribution, so it can be pelletized even at room temperature. Can be treated as Therefore, a film can be formed even when the propylene polymer (b1) is dry blended with the olefin polymer (A).

[Packaging materials]
The polyolefin-based composition of the present invention is suitably used for packaging materials. The molded body, film, stretched film, or stretched multilayer film comprising the polyolefin-based composition of the present invention is not particularly limited. For example, the packaging material for food use or industrial use, for example, fresh food, processed food , Materials that can be used to wrap and pack cooked products, retort foods, confectionery, beverages, etc. directly or indirectly (eg confectionery boxes), cigarette cases, pharmaceuticals, electrical components such as capacitors and capacitors, textiles, Materials that can be used for packaging and packaging of stationery, miscellaneous goods, plastic parts, metal parts, etc., or electrical parts such as capacitors and capacitors themselves, fibers, stationery, plastic parts, various reusable containers, laboratory equipment, speaker cones It can be used for a wide range of applications such as automobile parts or banknotes. As for the method of use, the film may be used as it is, may be used by being laminated with another film, or may be used after metal deposition.
Moreover, it can be used also for the flat yarn used as the flat tape (thread | yarn) which gave the intensity | strength by cutting a film into a strip shape (slit), and making it a uniaxially stretched film.
It can also be used as a protective film, synthetic paper, label, and seal substrate, and can be used for film synthetic paper, fiber synthetic paper, and film laminate synthetic paper.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

Below, the measuring method of the olefin polymer (A) used in the Example and an olefin polymer (B) is demonstrated.
[DSC measurement]
Using a differential scanning calorimeter (DSC-7, manufactured by Perkin Elmer Co.), a melting endotherm obtained by holding 10 mg of a sample at −10 ° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10 ° C./min. It calculated | required as melting endotherm (DELTA) HD from a curve. Moreover, melting | fusing point (Tm-D) was calculated | required from the peak top of the peak observed on the highest temperature side of the obtained melting endothermic curve.
The melting endotherm (ΔH-D) is a differential scanning calorimeter (manufactured by Perkin Elmer Co., Ltd.) with a line connecting a point on the low temperature side where there is no change in heat quantity and a point on the high temperature side where there is no change in heat quantity as the baseline , DSC-7), and calculating the area surrounded by the line portion including the peak of the melting endothermic curve obtained by DSC measurement and the base line.

[Weight average molecular weight (Mw), molecular weight distribution (Mw / Mn) measurement]
The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) method to determine the molecular weight distribution (Mw / Mn). For the measurement, the following equipment and conditions were used, and polystyrene-reduced weight average molecular weight and number average molecular weight were obtained. The molecular weight distribution (Mw / Mn) is a value calculated from these weight average molecular weight (Mw) and number average molecular weight (Mn).
<GPC measurement device>
Column: “TOSO GMHHR-H (S) HT” manufactured by Tosoh Corporation
Detector: RI detection for liquid chromatogram "WATERS 150C" manufactured by Waters Corporation
<Measurement conditions>
Solvent: 1,2,4-trichlorobenzene Measurement temperature: 145 ° C
Flow rate: 1.0 ml / min Sample concentration: 2.2 mg / ml
Injection volume: 160 μl
Calibration curve: Universal Calibration
Analysis program: HT-GPC (Ver.1.0)

[NMR measurement]
The ¹³ C-NMR spectrum was measured with the following apparatus and conditions. In addition, the attribution of the peak followed the method proposed by A. Zambelli et al. In “Macromolecules, 8, 687 (1975)”.
Apparatus: JNM-EX400 type ¹³ C-NMR apparatus manufactured by JEOL Ltd. Method: Proton complete decoupling method Concentration: 220 mg / ml
Solvent: 90:10 (volume ratio) mixed solvent of 1,2,4-trichlorobenzene and heavy benzene Temperature: 130 ° C
Pulse width: 45 °
Pulse repetition time: 4 seconds Integration: 10,000 times

<Calculation formula>
M = m / S × 100
R = γ / S × 100
S = Pββ + Pαβ + Pαγ
S: Signal intensity of side chain methyl carbon atoms of all propylene units Pββ: 19.8 to 22.5 ppm
Pαβ: 18.0 to 17.5 ppm
Pαγ: 17.5 to 17.1 ppm
γ: Racemic pentad chain: 20.7 to 20.3 ppm
m: Mesopentad chain: 21.7-22.5 ppm

The mesopentad fraction [mmmm], the racemic pentad fraction [rrrr] and the racemic meso racemic meso pendad fraction [rmrm] are described in “Macromolecules, 6, 925 (1973)” by A. Zambelli et al. are those determined in conformity with the proposed method, meso fraction in pentad units in the polypropylene molecular chain as measured by the signal of the methyl groups of the ^{13 C-NMR} spectrum, the racemic fraction and the racemic meso racemic meso It is a fraction. As the mesopentad fraction [mmmm] increases, the stereoregularity increases. The triad fractions [mm], [rr] and [mr] were also calculated by the above method.

[Melt flow rate (MFR) measurement]
Based on JIS K7210, the measurement was performed under conditions of a temperature of 230 ° C. and a load of 2.16 kg.

  The olefin polymer (A) used in the examples will be described below.

<Olefin polymer (A)>
In Examples 1 to 3 and Comparative Examples 1 to 3, as the olefin polymer (A-1), “F133A” (PP resin manufactured by Prime Polymer Co., Ltd., melting point (Tm-D): 168 ° C., melting endotherm (ΔH -D): 97 J / g, [mmmm]: 97 mol%, tensile modulus: 2000 MPa).
In Examples 4 and 5 and Comparative Examples 4 to 7, as the olefin polymer (A-2), “J3000GV” (PP resin manufactured by Prime Polymer Co., Ltd., melting point (Tm-D): 164 ° C., tensile modulus : 2000 MPa, stereoregularity [mmmm]: 94%, heat of fusion (ΔH-D): 92 J / g).

  Below, the manufacture example of the olefin polymer (B) used in the Example is demonstrated.

Production Example 1 [Production of Olefin Polymer (B)]
In a stainless steel reactor having an internal volume of 20 L with a stirrer, n-heptane was 20 L / hr, triisobutylaluminum was 15 mmol / hr, dimethylanilinium tetrakispentafluorophenylborate, and (1,2'-dimethylsilylene) A catalyst component obtained by contacting (2,1′-dimethylsilylene) -bis (3-trimethylsilylmethylindenyl) zirconium dichloride, triisobutylaluminum and propylene in a mass ratio of 1: 2: 20 in advance is used as zirconium. It was continuously supplied at a conversion of 6 μmol / hr.
Propylene and hydrogen were continuously supplied so as to keep the total pressure in the reactor at 1.0 MPa · G, and the polymerization temperature was appropriately adjusted to obtain a polymerization solution having a desired molecular weight.
An olefin polymer (B) was obtained by adding antioxidant to the obtained polymerization solution so that the content rate might become 1000 mass ppm, and then removing n-heptane which is a solvent.

  The olefin polymer (B) obtained in Production Example 1 was measured as described above. The results are shown in Table 1 below.

<Nucleating agent (C)>
As the nucleating agent (C), trade name “Clear master” (PP-RM-NSA RMX50, master batch, concentration: 20% by mass, sorbitol nucleating agent) manufactured by Dainichi Seika Kogyo Co., Ltd. was used.

<Evaluation of biaxially stretched film>
The physical properties of the biaxially stretched films prepared in Examples and Comparative Examples described later were evaluated by the following measurement methods. Moreover, the stretchability was also evaluated.
(Measurement of stretching stress)
Stretching stress measurement is detected when the MD stretched film is further TD stretched using a table tenter (manufactured by Iwamoto Seisakusho Co., Ltd.) and the MD stretched film is sandwiched between chucks and the TD stretch ratio is changed. The detected stress was detected by a detector attached to the table tenter. Draw a relationship line (curve) on the two-dimensional coordinate axis with the horizontal axis as the TD stretch ratio and the detected stress as the vertical axis, and change the first inflection point of the relationship line (the stretch ratio from the low stretch ratio to the high stretch ratio). The maximum value of the first inflection point that appears when changing was determined as the yield stretching stress.

(Measuring mechanical properties)
Tensile speed with a tensile tester (manufactured by Shimadzu Corp., “Autograph AG-I”) using a strip-shaped test piece of 200 mm × 15 mm collected from each of the MD direction and TD direction of the produced biaxially stretched film Tensile at 300 mm / min, elastic modulus, breaking strength and breaking elongation were determined.
In each test, measurements were taken 5 times in the MD direction and 5 times in the TD direction, and the average value was taken as the measurement value. In addition, the test piece of MD direction means here the test piece whose longitudinal direction of the said strip-shaped test piece is MD direction of a biaxially stretched film. The same applies to the TD direction.
(I) Elastic modulus Using a strip-shaped test piece of 200 mm × 15 mm, a tensile tester was used to pull at a chuck-to-chuck distance of 150 mm and a pulling speed of 300 mm / min. A relation line (curve) was drawn on the two-dimensional coordinate axis, and the inclination of the relation line before the yield point was obtained as “elastic modulus”. The higher the modulus of elasticity, the better the rigidity of the film.

(Measurement of optical properties)
(I) Transparency (total haze / internal haze) measurement Based on JIS K7105 and JIS K7136, it measured using "ISO haze meter (NDH2000)" by Nippon Denshoku Industries Co., Ltd. In addition, transparency is so high that the value of total haze and internal haze is small.
Total haze or internal haze (%) = Td / Tt × 100
(Where, Td: diffuse transmittance, Tt: total light transmittance)
(Ii) Measurement of gloss (gloss) Based on JIS K7105 and JIS Z8741, it measured using the gloss meter "VG2000" by Nippon Denshoku Industries Co., Ltd. The 60-degree specular gloss was measured. Further, the higher the gloss value, the higher the glossiness.

Example 1
5% by mass of the olefin polymer (B) of Production Example 1 and 93% by mass of the olefin polymer (A-1) (PP, manufactured by Prime Polymer Co., F133A, melting point: 168 ° C.) as a nucleating agent (C) The product name “Clear master” manufactured by Dainichi Seika Kogyo Co., Ltd. (PP-RM-NSA RMX50, masterbatch, concentration: 20% by mass) 2% by mass of dry blended product is formed into a 50 mm sheet by Thermo Plastics While extruding at 250 ° C. by a machine, a 1000 μm thick single layer film was produced. At this time, the temperature of the cooling roll was 50 ° C. The obtained single layer film sheet was stretched in the machine direction (MD, longitudinal stretching) by a roll stretching machine manufactured by Iwamoto Seisakusho under the conditions of stretching temperature: 152 ° C. and longitudinal stretching ratio: 5 times, and then manufactured by Iwamoto Seisakusho. With a table tenter, the film is prepared by stretching in a direction perpendicular to the machine direction (TD, transverse stretching) at a stretching temperature of 168 ° C., and a preheating time at each transverse stretching is 68 seconds. A biaxially stretched film having a thickness of 21 μm and different transverse stretching temperatures was produced under the conditions of stretching speed: 6500% / min and stretching ratio: 9.5 times. The elastic modulus and optical properties of the obtained film were evaluated. The results are shown in Table 2.

Example 2
A biaxially stretched film was produced according to Example 1 except that the transverse stretching temperature was changed. The elastic modulus and optical properties of the obtained film were evaluated. The results are shown in Table 2.

Comparative Examples 1 and 2
Biaxially stretched films were prepared in the same manner as in Example 1 except that the formulation shown in Table 2 was used. The elastic modulus and optical properties of the obtained film were evaluated. The results are shown in Table 2.

  From the evaluation results of Table 2, by adding the polyolefin resin (B), even if a nucleating agent is added, the elastic modulus becomes equal to or higher than that, and the gloss is improved by adding the nucleating agent. I understand that.

Example 3 and Comparative Example 3
A film was prepared in accordance with Example 1 except that the composition in Table 3 and the transverse stretching temperature were changed to 164 ° C, 165 ° C, 166 ° C, 167 ° C, and 169 ° C. The stretchability of the film was evaluated by the ratio of the number of successes out of the total number of stretches, assuming that the film was stretched three or more times under the same conditions, and the case where no breakage and unevenness in stretch were observed was a success. The evaluation criteria means that A is a stretching success probability of 75% or more, B is less than 75% of the stretching success probability and 25% or more, and C is a stretching success probability of less than 25% or not stretchable. Further, “unstretchable” corresponds to a case where a thickness unevenness or undrawn portion is confirmed in the fracture or appearance. The results are shown in Table 3.
In addition, when the stretched film was watermarked on a fluorescent lamp, the presence or absence of a ruptured pattern (not thickness unevenness or a saw) was observed. A film in which no pattern was observed was evaluated as ◯, an observed film was evaluated as x, and a film observed at a part of the edge of the film was evaluated as Δ. A film evaluated as x is not suitable as a product because it has a poor appearance when made into a product. On the other hand, if Δ, ○, the appearance is good and the product can be commercialized.

  As can be seen from Table 3, by including the olefin polymer (B), it was found that even if a nucleating agent was added, sufficient stretchability was obtained even at a lower temperature. Moreover, the pattern which burst on the film surface by containing an olefin type polymer (B) was only observed only at a part of edge of a film.

Examples 4 and 5 and Comparative Examples 4 to 7
As the olefin polymer (B) and olefin polymer (A-2) of Production Example 1 (PP, Prime Polymer Co., Ltd., J3000GV, melting point: 164 ° C.) The company-made product name “Clear master” (PP-RM-NSA RMX50, master batch, concentration: 20% by mass) was dry blended at a blending ratio shown in Table 4, and an injection molding machine (Toshiba Machine Co., Ltd., Product name: IS75E), molding temperature 180 ° C, mold temperature 40 ° C, injection pressure 2MPa, injection time 20 seconds, thickness 1mm, 150mm x 150mm mold use injection mold, 1000μm thick square plate An injection-molded body was prepared. The elastic modulus and optical characteristics of the obtained injection molded product were evaluated. The results are shown in Table 4.
The haze includes “external haze” caused by unevenness on the surface of the measurement sample (film) and “internal haze” caused by microcrystals existing in the film. The internal haze value was measured using a haze meter (model number: NDH2000—manufactured by Nippon Denshoku Industries Co., Ltd.) according to JISK7105 described above.

  As can be seen from Table 4, from the results of Comparative Example 4 and Examples 4 and 5, by adding the olefin polymer (B) and the nucleating agent, the optical characteristics are remarkably maintained while maintaining the mechanical characteristics. It turns out that it improves. Moreover, it can be seen from the results of Comparative Example 5 and Examples 4 and 5 that the elongation at break is remarkably improved by having the olefin polymer (B) when the nucleating agent is added. Furthermore, it can be seen from the results of Comparative Examples 6 and 7 and Examples 4 and 5 that the total haze, internal haze, and gloss are significantly improved by having the nucleating agent.

The polyolefin-based composition of the present invention can be stretched in a lower temperature region, and is excellent in mechanical properties and optical properties after stretching. Therefore, it can be used for packaging materials for food use, industrial use, etc., and for electricity such as capacitors and capacitors. Can be used in a wide range of applications such as materials, textiles, stationery, plastic parts, various reusable containers, laboratory equipment, speaker cones, automobile parts such as fenders and bumpers, household appliance parts such as housings, hollow containers, and banknotes. .
The polyolefin composition of the present invention is suitable for injection molding, extrusion molding and the like because it can be stretched in a lower temperature region.

Claims (14)

A stretched film comprising a polyolefin-based composition containing the following components (a) to (c) and oriented in at least one direction and having a gloss (gloss) of 150.3% or more.
(A) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. Olefin polymer (A) whose melting point (Tm-D) defined as the observed peak top exceeds 120 ° C
(B) Using a differential scanning calorimeter (DSC), the sample was held at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then heated at 10 ° C./min. Olefin polymer (B) having a calorific value (ΔH-D) of 0 to 80 J / g and a molecular weight distribution (Mw / Mn) of less than 3.0
(C) Nucleating agent (C)   The content of the olefin polymer (B) is 0.5% by mass or more and less than 50% by mass with respect to 100% by mass of the total amount of the following components (a) and (b). Stretched film.   The content of the nucleating agent (C) is 0.01 to 2 parts by mass when the total of the component (a) and the component (b) is 100 parts by mass. Stretched film.   The nucleating agent (C) is an organic carboxylic acid or a metal salt thereof, an aromatic sulfonate or a metal salt thereof, an organic phosphate compound or a metal salt thereof, dibenzylidene sorbitol or a derivative thereof, a rosin acid partial metal salt, inorganic fine particles The stretched film according to any one of claims 1 to 3, which is selected from at least one selected from amides, amides, amides, quinacridones, and quinones.   The stretched film according to any one of claims 1 to 4, wherein the olefin polymer (A) is a propylene polymer (a1).   Stretching according to any one of claims 1 to 5, wherein the olefin polymer (B) is a propylene polymer (b1) in which 50 mol% or more of monomers constituting the polymer are propylene monomers. the film. The stretched film according to claim 6, wherein the propylene polymer (b1) satisfies at least one of the following (i) and (ii).
(I) The structural unit of ethylene is contained in excess of 0 mol% and 20 mol% or less.
(Ii) The structural unit of 1-butene is contained in an amount exceeding 0 mol% and not more than 30 mol%. The stretched film according to claim 6, wherein the propylene polymer (b1) satisfies the following (1).
(1) [mmmm] is 20 to 60 mol% The stretched film according to any one of claims 6 to 8, wherein the propylene polymer (b1) satisfies the following (2).
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. The melting point (Tm-D) defined as the observed peak top is 0-120 ° C. The stretched film according to claim 8, wherein the propylene polymer (b1) satisfies the following (2) and (3).
(2) Using a differential scanning calorimeter (DSC), hold the sample at −10 ° C. for 5 minutes in a nitrogen atmosphere, and then raise the temperature at 10 ° C./min. The melting point (Tm-D) defined as the observed peak top is 0-120 ° C.
(3) [rrrr] / (1- [mmmm]) ≦ 0.1 The stretched film according to any one of claims 8 and 10, wherein the propylene polymer (b1) satisfies the following (4) and (5).
(4) [rmrm]> 2.5 mol%
(5) [mm] × [rr] / [mr] ² ≦ 2.0   The stretched film according to any one of claims 1 to 11, wherein the polyolefin-based composition is a polyolefin-based composition for extrusion molding.   It is a manufacturing method of a stretched film given in any 1 paragraph of Claims 1-12, Comprising: Heating the film which consists of the above-mentioned polyolefin system composition, and obtaining by uniaxial or biaxial direction simultaneously or sequentially, A method for producing a stretched film.   The packaging material containing the stretched film of any one of Claims 1-12.