JP2010144007A - Inflation film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inflation film having excellent transparency, surface gloss and molding processability by performing air-cooled inflation forming of a propylene-based polymer composition comprising a specific syndiotactic propylene polymer and a propylene-α-olefin copolymer. <P>SOLUTION: The inflation film is obtained by performing air-cooled inflation forming of a propylene-based polymer composition comprising 100-50 pts.wt. of a syndiotactic propylene polymer (A) and 0-50 pts.wt. of a propylene-α-olefin copolymer (B) (the total of (A) and (B) is 100 pts.wt.). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to an inflation film obtained from a propylene-based polymer composition containing a syndiotactic propylene polymer and a propylene / α-olefin copolymer, and more specifically, an air-cooled inflation molding of the propylene-based polymer composition. It is related with the inflation film obtained.

Currently, polypropylene blown films are widely used in various packaging materials because they are inexpensive and excellent in transparency, rigidity, moisture resistance and heat resistance.
Isotactic polypropylene film is inexpensive and has excellent rigidity, moisture resistance, and heat resistance, so it is used in various applications. However, there is a problem that transparency is insufficient. Polymers have been used but are still not sufficient and further improvements are desired. When an isotactic polypropylene film is produced by an inflation method, it is usually necessary to lower the crystallinity of the polypropylene and increase the transparency of the film by water cooling, that is, rapid cooling. This is because when air cooling, that is, slow cooling, crystallization proceeds, the flexibility of the film is lost, impact resistance is lowered, and transparency is lowered. Therefore, at present, as a processing method for polyethylene or the like, a normal air-cooled inflation method can hardly be used.

  On the other hand, J. A. It was discovered by Ewen et al. That a transition metal catalyst having an asymmetric ligand and a catalyst comprising an aluminoxane can obtain a high-tacticity polypropylene having a syndiotactic pentad fraction exceeding 0.7 (Non-patent Documents). 1). This syndiotactic polypropylene has extremely high transparency and surface gloss as compared with conventional isotactic polypropylene, and is excellent in flexibility, so that it is expected to be used as a transparent and flexible film. Moreover, as the forming method, a forming method similar to that of a conventional isotactic polypropylene film, for example, a T-die extrusion method or a water-cooled inflation method (see Patent Document 1) can be used.

A film made of syndiotactic polypropylene has better properties such as transparency and surface gloss than a film obtained from isotactic polypropylene, and is expected to develop its application. However, since syndiotactic polypropylene has a slower crystallization speed and lower crystallinity than isotactic polypropylene, when the film is processed by the inflation method, the tube extruded from the die winds around the water-cooled ring, When folded with a pinch roll, it is easy to fuse and there is a problem that the opening is not sufficient.
JP-A-3-81130 J. Am. Chem. Soc., Vol. 110, 6255-6256 (1988)

The present invention provides an inflation excellent in transparency, surface gloss and molding processability by subjecting a propylene polymer composition containing a specific syndiotactic propylene polymer and a propylene / α-olefin copolymer to air-cooling inflation molding. It is an object to provide a film.

As a result of intensive studies on the above problems, the inventors of the present invention have made clear by performing inflation molding of a propylene-based polymer composition containing a specific syndiotactic propylene polymer and a propylene / α-olefin copolymer by an air cooling method. It has been found that an inflation film having extremely high properties and surface gloss and excellent mechanical strength can be provided, and the present invention has been completed.

That is, the present invention includes the following matters.
[1] Syndiotactic propylene polymer (A) 100-50 parts by weight and propylene / α-olefin copolymer (B) 0-50 parts by weight (however, the sum of (A) and (B) is 1
00 parts by weight. And a syndiotactic propylene polymer (A) satisfying the following requirement (a), wherein the propylene / α-olefin is an inflation film obtained by air-cooling inflation molding of a propylene-based polymer composition comprising: A blown film characterized in that the copolymer (B) satisfies the following requirement (b).

(A): The syndiotactic pentad fraction (rrrr fraction) measured by ¹³ C-NMR is 85% or more, and the melting point (Tm) obtained from DSC is 145 ° C. or more, which is derived from propylene. The structural unit is contained in an amount exceeding 90 mol% (however, the total amount of the structural units in the syndiotactic propylene polymer (A) is 100 mol%).

(B): Containing structural units derived from propylene in an amount of 55 to 90 mol%, and 10 to 45 mol% of structural units derived from an α-olefin having 2 to 20 carbon atoms (excluding propylene) (however, The total of the structural unit derived from propylene and the structural unit derived from an α-olefin having 2 to 20 carbon atoms (excluding propylene) is 100 mol%), and in JIS K-6721 The MFR measured at 230 ° C. and a 2.16 kg load is in the range of 0.01 to 100 g / 10 minutes, and at least one of the following requirements (b-1) and (b-2) is satisfied. Fulfill.

(B-1): The syndiotactic triad fraction (rr fraction) measured by ¹³ C-NMR method is 60% or more.
(B-2): The intrinsic viscosity [η] (dL / g) measured in 135 ° C. decalin and the MFR (g / 10 minutes, 230 ° C., 2.16 kg load) satisfy the following relational expression.

1.50 × MFR ^(-0.20) ≦ [η] ≦ 2.65 × MFR ^(-0.20)
[2] (1) The inflation film according to [1], wherein an internal haze value measured at a thickness of 50 μm is 2% or less.
[3] (1) The internal haze value measured at a thickness of 50 μm is 2% or less, and (2) the gloss at an incident angle of 20 ° measured in accordance with JIS K 7105 is 120% or more. The inflation film as described in [1] or [2].
[4] (1) The internal haze value measured at a thickness of 50 μm is 2% or less, (2) the gloss at an incident angle of 20 ° measured in accordance with JIS K 7105 is 120% or more, and (3) JIS The blown film according to any one of [1] to [3], wherein the propylene-based polymer composition has a needle entry temperature of 145 ° C. or higher measured according to K7197.
[5] (1) The internal haze value measured at a thickness of 50 μm is 2% or less, (2) the gloss at an incident angle of 20 ° measured in accordance with JIS K 7105 is 120% or more, and (3) JIS The needle penetration temperature of the propylene polymer composition measured according to K 7197 is 145 ° C. or higher, and (4) the tensile elastic modulus of the propylene polymer composition measured according to JIS K6301 is 100. The inflation film according to any one of [1] to [4], which is in a range of ˜2000 MPa.
[6] Melting the intrinsic viscosity [η] of the syndiotactic propylene polymer (A) measured in decalin at 135 ° C. in the range of 0.1 to 10 dL / g and determined by a differential scanning calorimeter (DSC) The inflation film according to any one of [1] to [5], wherein the heat quantity (ΔH) is 40 mJ / mg or more.
[7] The molecular weight distribution (Mw / Mn) determined by gel permeation chromatography (GPC) of the propylene / α-olefin polymer (B) is 3.5 or less [1] to [1] [6] The inflation film according to any one of [6].

  Since the propylene polymer composition according to the present invention is excellent in moldability, an inflation film obtained by air-cooled inflation molding of the propylene polymer composition is excellent in transparency, surface glossiness and mechanical strength. .

The inflation film of the present invention comprises a syndiotactic propylene polymer (A) 100 to 50 parts by weight, a propylene / α-olefin copolymer (B) 0 to 50 parts by weight (provided that (A) and (B) The syndiotactic propylene polymer (A) satisfies the following requirement (a), and the propylene-based polymer composition comprising: The α-olefin copolymer (B) satisfies the following requirement (b).

(A): The syndiotactic pentad fraction (rrrr fraction) measured by ¹³ C-NMR is 85% or more, and the melting point (Tm) obtained from DSC is 145 ° C. or more, which is derived from propylene. The structural unit is contained in an amount exceeding 90 mol% (however, the total amount of the structural units in the syndiotactic propylene polymer (A) is 100 mol%).

(B): Containing structural units derived from propylene in an amount of 55 to 90 mol%, and 10 to 45 mol% of structural units derived from an α-olefin having 2 to 20 carbon atoms (excluding propylene) (however, The total of the structural unit derived from propylene and the structural unit derived from an α-olefin having 2 to 20 carbon atoms (excluding propylene) is 100 mol%), and in JIS K-6721 The MFR measured at 230 ° C. and a 2.16 kg load is in the range of 0.01 to 100 g / 10 minutes, and at least one of the following requirements (b-1) and (b-2) is satisfied. Fulfill.

(B-1): The syndiotactic triad fraction (rr fraction) measured by ¹³ C-NMR method is 60% or more.
(B-2): The intrinsic viscosity [η] (dL / g) measured in 135 ° C. decalin and the MFR (g / 10 minutes, 230 ° C., 2.16 kg load) satisfy the following relational expression.

1.50 × MFR ^(-0.20) ≦ [η] ≦ 2.65 × MFR ^(-0.20)
Hereinafter, the inflation film of the present invention will be specifically described.
[Syndiotactic propylene polymer (A)]
The syndiotactic propylene polymer (A) according to the present invention may be homopolypropylene, a random copolymer or block copolymer of propylene and an α-olefin having 2 to 20 carbon atoms (excluding propylene). It may be a combination, but is preferably a homopolypropylene or a random copolymer of propylene and an α-olefin having 2 to 20 carbon atoms (excluding propylene), more preferably homopolypropylene or propylene and 2 carbon atoms. Is a random copolymer of 10 to 10 α-olefin (excluding propylene), particularly preferably homopolypropylene or a random copolymer of propylene, ethylene and an α-olefin having 4 to 10 carbon atoms, most preferably It is homopolypropylene in terms of heat resistance

Here, as the α-olefin having 2 to 20 carbon atoms other than propylene, ethylene,
1-butene, 3-methyl-1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1- Examples include octadecene and 1-eicosene.

  The structural unit derived from propylene is contained in an amount usually exceeding 90 mol%, preferably 91 mol% or more, in a total of 100 mol% of the structural units in the syndiotactic propylene polymer (A). Further, when the syndiotactic propylene polymer (A) is a propylene / α-olefin random copolymer, the structural unit derived from the α-olefin having 2 to 20 carbon atoms (excluding propylene) is reduced to 0.0. It is contained in an amount of 3 to 7 mol%, preferably 0.3 to 6 mol%, particularly preferably 0.3 to 5 mol%.

  The syndiotactic propylene polymer (A) has a syndiotactic pentad fraction (rrrr fraction, pentad syndiotacticity) measured by NMR method of usually 85% or more, preferably 90% or more, more preferably. Is 93% or more, more preferably 94% or more. When the rrrr fraction is in the above range, the syndiotactic propylene polymer (A) is excellent in moldability, heat resistance and transparency, and has good properties as crystalline polypropylene. Therefore, by using the syndiotactic propylene polymer (A), crystallization of the propylene polymer composition is suppressed, low crystallization and fine spherulization occur, and the resulting inflation film of the present invention is transparent. Will be expensive. The upper limit of the rrrr fraction is not particularly limited, but is usually 99% or less, for example.

This syndiotactic pentad fraction (rrrr fraction) is measured as follows.
The rrrr fraction is expressed as Prrrr in the ¹³ C-NMR spectrum (absorption intensity derived from the methyl group of the third unit in a site where 5 units of propylene units are continuously syndiotactically bonded) and Pw (total methyl groups of propylene units). (Absorption intensity derived from the above) is determined by the following formula (1).

rrrr fraction (%) = 100 × Prrrr / Pw (1)
The NMR measurement is performed as follows, for example. That is, 0.35 g of a sample is dissolved by heating in 2.0 ml of hexachlorobutadiene. After this solution is filtered through a glass filter (G2), 0.5 ml of deuterated benzene is added and charged into an NMR tube having an inner diameter of 10 mm. And ¹³ C-NMR measurement is performed at 120 degreeC using the JEOL GX-500 type | mold NMR measuring apparatus. The number of integration is 10,000 times or more.

  The intrinsic viscosity [η] of the syndiotactic propylene polymer (A) measured at 135 ° C. in decalin is usually 0.1 to 10 dL / g, preferably 0.5 to 10 dL / g, more preferably 0.5. -8 dL / g, more preferably 0.95 to 8 dL / g, even more preferably 1 to 8, particularly preferably 1.4 to 8 dL / g, most preferably 1.4 to 5 dL / g. When the intrinsic viscosity [η] value is in the above range, the syndiotactic propylene polymer (A) exhibits good fluidity, so it can be easily blended with other components, and the inflation film has excellent mechanical strength. It becomes.

Furthermore, the melting point (Tm) obtained by differential scanning calorimetry (DSC) measurement of the syndiotactic propylene polymer (A) is usually 145 ° C or higher, preferably 147 ° C or higher, more preferably 150 ° C or higher. More preferably, it is 155 ° C. or higher, and particularly preferably 156 ° C. or higher. The upper limit of Tm is not particularly limited, but is usually 170 ° C. or lower, for example. Further, the heat of fusion (ΔH) obtained by the differential scanning calorimeter (DSC) measurement of the syndiotactic propylene polymer (A) is usually 40 mJ / mg or more, preferably 45 m.
J / mg or more, more preferably 50 mJ / mg or more, further preferably 52 mJ / mg or more, particularly preferably 55 mJ / mg or more.

The differential scanning calorimeter (DSC) measurement is performed as follows, for example. Sample 5.00m
About g is packed in a special aluminum pan, DSCPyris1 or DSC made by PerkinElmer
7 to 30 ° C. to 200 ° C. at a rate of 320 ° C./min, held at 200 ° C. for 5 minutes, then from 200 ° C. to 30 ° C. at a rate of 10 ° C./min. After holding, the melting point (Tm) and the heat of fusion (ΔH) are determined from the endothermic curve when the temperature is raised at 10 ° C./min. When a plurality of peaks are detected during DSC measurement, the peak detected on the highest temperature side is defined as the melting point (Tm).

  The syndiotactic propylene polymer (A) having a melting point (Tm) or heat of fusion (ΔH) in the above range is excellent in moldability, heat resistance and mechanical properties, and has good properties as crystalline polypropylene. Therefore, the propylene-based polymer composition containing the syndiotactic propylene polymer (A) according to the present invention has excellent molding processability when molding an inflation film, and the resulting inflation film has excellent mechanical strength. Become. The syndiotactic propylene polymer (A) having a melting point (Tm) in the above range is produced by setting a catalyst system and polymerization conditions in the production method of the syndiotactic propylene polymer (A) described later.

  The syndiotactic propylene polymer (A) can be produced by a polymerization method using a crosslinked metallocene compound as a polymerization catalyst. Specifically, it can be produced by the method described in International Publication No. 2006/123759.

The syndiotactic propylene polymer (A) according to the present invention is a total of 100 syndiotactic propylene polymer (A) and propylene / α-olefin copolymer (B).
In the parts by weight, it is usually 100 to 50 parts by weight, preferably 100 to 55 parts by weight, more preferably 100 to 60 parts by weight. When the content of the syndiotactic propylene polymer (A) is in the above range, it is preferable from the viewpoints of heat resistance and mechanical strength of the propylene-based polymer composition.

  Further, the molecular weight distribution (Mw / Mn) in terms of standard polystyrene measured by gel permeation chromatography (GPC) of the syndiotactic propylene polymer (A) is usually 3.5 or less, preferably 3.0 or less. Preferably it is 2.5 or less.

[Propylene / α-olefin copolymer (B)]
In the propylene / α-olefin copolymer (B) according to the present invention, the structural unit derived from propylene is usually 55 to 90 mol%, preferably 55 to 85 mol%, more preferably 60 to 85 mol%, and carbon atoms. The structural unit derived from an α-olefin of 2 to 20 (excluding propylene) is usually contained in an amount of 10 to 45 mol%, preferably 15 to 45 mol%, more preferably 15 to 40 mol%. However, the total of the structural unit derived from propylene and the structural unit derived from an α-olefin having 2 to 20 carbon atoms (excluding propylene) is 100 mol%.

Examples of the α-olefin having 2 to 20 carbon atoms (excluding propylene) include ethylene, 3-methyl-1-butene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-
Examples include octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicocene. Among these, ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene are preferable, and ethylene is more preferable.

As described above, the propylene / α-olefin copolymer (B) includes propylene / α-olefin copolymer (B).
It is preferable to use an ethylene copolymer, but in addition to the propylene / ethylene copolymer, a structural unit derived from propylene, a structural unit derived from ethylene, 1-butene, 1-hexene, 4-methyl-1- It consists of structural units derived from at least one monomer selected from pentene and 1-octene (hereinafter also referred to as “HAO comonomer”), and the proportion (mol%) of structural units derived from ethylene is from HAO comonomer. A propylene / ethylene / HAO copolymer larger than the ratio (mol%) of the structural unit to be introduced may be used. In this case, the propylene / ethylene / HAO copolymer is usually 55 to 85 mol%, preferably 60 to 85 mol% of structural units derived from propylene, and 15 to 45 mol of structural units derived from ethylene and the HAO comonomer. %, Preferably 15 to 40 mol%. The total of the structural units derived from propylene and the structural units derived from ethylene and the HAO comonomer is 100 mol%.

When the component constituting the propylene / α-olefin copolymer (B) is in the above range,
The propylene-based polymer composition according to the present invention is particularly excellent in the balance of heat resistance, transparency and impact resistance.

The propylene / α-olefin copolymer (B) according to the present invention has a melt flow rate (MFR) measured at 230 ° C. and a 2.16 kg load in accordance with JIS K-6721 of 0.0.
It exists in the range of 1-100 g / min, and satisfy | fills any one or more of following requirements (b-1) and (b-2).

(B-1): The syndiotactic triad fraction (rr) measured by ¹³ C-NMR method is 60% or more.
(B-2): Intrinsic viscosity [η] (dL / g) measured in 135 ° C. decalin and JIS K
MFR (g / 10 minutes) measured at 230 ° C. and a 2.16 kg load in accordance with −6721 satisfies the following relational expression.

1.50 × MFR ^(-0.20) ≦ [η] ≦ 2.65 × MFR ^(-0.20)
The propylene / α-olefin copolymer (B) preferably has an MFR measured at 230 ° C. under a load of 2.16 kg in accordance with JIS K-6721, usually in the range of 0.01 to 100 g / 10 min. Is in the range of 0.02 to 100 g / 10 min.

The requirement (b-1) will be described below.
(B-1): The syndiotactic triad fraction (rr fraction, triad syndiotacticity) measured by the ¹³ C-NMR method of the propylene / α-olefin copolymer (B) is usually 60% or more, preferably Is 70% or more, more preferably 75% or more. When the rr fraction is in the above range, the propylene / α-olefin copolymer (B) has good compatibility with the syndiotactic propylene polymer (A).

  The polymer satisfying the requirement (b-1) can be obtained, for example, by copolymerizing propylene and α-olefin in the presence of a catalyst capable of producing syndiotactic polypropylene. It can also be produced using the method described in the 2006/123759 pamphlet.

The rr fraction is Prr in the ¹³ C-NMR spectrum (absorption intensity derived from the methyl group of the second unit at the site where three units of propylene units are continuously syndiotactically bonded) and Pw (total methyl groups of propylene units). (Absorption intensity derived from the above) is determined by the following formula (2).

rr fraction (%) = 100 × Prr / Pw (2)
Here, absorption derived from mr (absorption derived from at least both syndiotactic bonds and isotactic bonds among three propylene units; used for determination of Pmr (absorption intensity)), absorption derived from rr (propylene Absorption derived from the methyl group of the second unit at the site where 3 units are continuously syndiotactically bonded; used for determining Prr (absorption intensity)) or absorption derived from mm (3 units of propylene units continuously) If the absorption derived from the methyl group of the second unit at the isotactic bond site (used to determine Pmm (absorption intensity)) overlaps with the absorption derived from the comonomer, the contribution of the comonomer component is not subtracted. Calculate as is.

Specifically, among the descriptions of how to obtain the “syndiotacticity parameter (SP value)” described in paragraphs [0018] to [0031] of JP-A-2002-097325, [
It calculates | requires by calculating using said Formula (2) from the integrated intensity | strength of the signal of 1st area | region, 2nd area | region, and 3rd area | region described in the paragraphs [0018]-[0023].

In the present invention, the rr ₁ value, specifically, according to the method for obtaining the “syndiotacticity parameter (SP value)” described in paragraphs [0018] to [0031] of JP-A-2002-097325. The obtained value is usually 60% or more, preferably 65% or more, more preferably 70% or more. The rr ₁ value is the absorption derived from mr, rr in the calculation of the rr value.
When the absorption derived from the origin or the absorption derived from mm and the absorption derived from the comonomer overlap, the contribution of the comonomer component is subtracted.

In the measurement of the rr value and the rr ₁ value, the ¹³ C-NMR measurement is performed, for example, as follows. That is, 0.35 g of a sample is dissolved by heating in 2.0 ml of hexachlorobutadiene. After this solution is filtered through a glass filter (G2), 0.5 ml of deuterated benzene is added and charged into an NMR tube having an inner diameter of 10 mm. And JEOL GX-400 type N
Using the MR measuring device, temperature 120 ° C., the number of integrations do ¹³ C-NMR measurement at 8,000 times or more.

Next, requirement (b-2) will be described.
(B-2): The propylene / α-olefin copolymer (B) has an intrinsic viscosity [η] (dL / g) measured in decalin of 135 ° C. and 230 ° C. according to JIS K-6721.
The melt flow rate (MFR) (g / 10 minutes) measured with a 2.16 kg load satisfies the following relational expression.

1.50 × MFR ^(-0.20) ≦ [η] ≦ 2.65 × MFR ^(-0.20)
Preferably, the following relational expression is satisfied.
1.80 × MFR ^(−0.20) ≦ [η] ≦ 2.50 × MFR ^(−0.19)
The propylene / α-olefin copolymer (B) satisfying the above relational expression is preferable because of good compatibility with the syndiotactic propylene polymer (A).

The propylene / α-olefin copolymer (B) satisfying the above formula may be a copolymer of propylene and α-olefin using a catalyst capable of producing a syndiotactic propylene polymer, for example. Polymerization may be performed using the catalyst. The propylene / α-olefin copolymer (B) thus obtained is a syndiotactic propylene polymer (A
) And good compatibility.

The propylene / α-olefin copolymer (B) satisfying the requirement (b-2) has the same intrinsic viscosity [η] as that of the conventional isotactic propylene copolymer, but has a high MFR value. .

  This is described in “Macromolecules” 1998, Vol. 31, p. The molecular weight between entanglement points of isotactic polypropylene (reported as Me = 6900 (g / mol) in the paper) and the molecular weight between entanglement points of syndiotactic polypropylene as described in 1335-1340. In this case, it is considered that this is caused by a difference from Me = 2170 (g / mol). That is, when [η] is the same, having a syndiotactic structure increases the number of entanglement points as compared with a material having an isotactic structure, and thus the MFR value is considered to be high.

As described above, the propylene / α-olefin copolymer (B) satisfying any one or more of the requirements (b-1) and (b-2) is a steric rule different from the isotactic structure. It is considered to have a syndiotactic structure that is a sex. Therefore, it is considered that the propylene / α-olefin copolymer (B) exhibits good compatibility with the component (A).

The propylene / α-olefin copolymer (B) is a preferred embodiment of propylene / α-olefin copolymer (B).
In the ethylene copolymer and the propylene / ethylene / HAO copolymer, it is preferable to satisfy both of the above requirements (b-1) and (b-2).

The intrinsic viscosity [η] of propylene / α-olefin copolymer (B) measured at 135 ° C. in decalin is usually 0.1 to 10 dL / g, preferably 0.5 to 10 dL / g, more preferably 0. .5 to 7.0 dL / g.

This propylene / α-olefin copolymer (B) has a single glass transition temperature, and the glass transition temperature (Tg) obtained by differential scanning calorimetry (DSC) measurement is usually 0 ° C. or lower. It is preferable. Glass transition temperature of propylene / α-olefin copolymer (B) (
When Tg) is in the above range, the propylene polymer composition is excellent in cold resistance and low temperature characteristics.

The differential scanning calorimetry is performed as follows, for example. About 10.00 mg of sample is packed in a special aluminum pan, and the temperature is increased from 30 ° C. to 200 ° C. at 200 ° C./min using a DSCRDC220 manufactured by Seiko Instruments Inc. The temperature is lowered to −100 ° C. at 10 ° C./min, held at −100 ° C. for another 5 minutes, and then the glass transition temperature (Tg) is obtained from an endothermic curve when the temperature is raised at 10 ° C./min.

The molecular weight distribution (Mw / Mn) in terms of standard polystyrene measured by gel permeation chromatography (GPC) of this propylene / α-olefin copolymer (B) is preferably 3.5 or less, more preferably 3.0 or less, particularly preferably 2.5 or less.

The propylene / α-olefin copolymer (B) can be produced by a polymerization method using a crosslinked metallocene compound as a polymerization catalyst. Specifically, it can be produced by the method described in International Publication No. 2006/123759.

The propylene / α-olefin copolymer (B) according to the present invention is 0 to 50 parts by weight in a total of 100 parts by weight of the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B). , Preferably 0 to 45 parts by weight, particularly preferably 0 to 40 parts by weight. When the content of the propylene / α-olefin copolymer (B) is in the above range, it is preferable from the viewpoints of heat resistance, transparency, surface gloss, and mechanical strength.

[Other ingredients]
<Isotactic polypropylene>
The propylene polymer composition containing the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B) according to the present invention may contain isotactic polypropylene as necessary. Good. By containing isotactic polypropylene, the mechanical strength, transparency and surface gloss of the resulting inflation film are increased.

As the isotactic polypropylene, commercially available ones can be used without particular limitation, but the isotactic pentad fraction measured by ¹³ C-NMR method is usually 0.9 or more, preferably 0. It is preferable to use a polypropylene of 95 or more.

  Specifically, a propylene homopolymer or a copolymer of propylene and an α-olefin having 2 to 20 carbon atoms (excluding propylene) can be used. Examples of the α-olefin having 2 to 20 carbon atoms (excluding propylene) include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1 -Dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like can be mentioned, among which ethylene and an α-olefin having 4 to 10 carbon atoms are preferable. These α-olefins may form a random copolymer with propylene or a block copolymer. The structural unit derived from these α-olefins may be contained in the isotactic polypropylene in a proportion of usually 40 mol% or less, preferably 20 mol% or less.

  The melt flow rate (MFR) measured at 230 ° C. under a load of 2.16 kg in accordance with ASTM D 1238 of isotactic polypropylene is usually 0.01 to 1000 g / 10 minutes, preferably 0.05 to 500 g / 10 minutes. It is.

  The isotactic polypropylene is, for example, a Ziegler catalyst comprising (a) a solid catalyst component containing magnesium, titanium, halogen and an electron donor as essential components, (b) an organoaluminum compound, and (c) an electron donor. It can manufacture by superposing | polymerizing using a system. It can also be produced similarly using a metallocene catalyst.

  The isotactic polypropylene used in the present invention is a propylene / ethylene random copolymer and a propylene / ethylene block copolymer having a good balance of whitening resistance and impact resistance among polypropylene copolymers produced by a Ziegler catalyst. Polymers are particularly preferred.

The amount of isotactic polypropylene added is usually 0.1 to 30 parts by mass, preferably 100 parts by mass, preferably 100 parts by mass of the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B). It is 0.1-25 mass parts, More preferably, it is 0.1-20 mass parts. When the addition amount of isotactic polypropylene is in the above range, an inflation film excellent in transparency, surface gloss and mechanical strength can be obtained.

<Polyethylene>
The propylene-based polymer composition containing the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B) according to the present invention may contain polyethylene as necessary. By containing polyethylene, the mechanical strength, transparency and surface gloss of the resulting inflation film are increased.

As the polyethylene, commercially available ones can be used without particular limitation, but the density measured by the density gradient tube method is usually 0.89 g / cm ³ or more, preferably 0.90 g / cm ³ or more. It is desirable to use polyethylene.

  The melt flow rate (MFR) measured at 190 ° C. under a load of 2.16 kg in accordance with ASTM D 1238 of polyethylene is usually 0.01 to 1000 g / 10 minutes, preferably 0.05 to 500 g / 10 minutes.

  This polyethylene uses, for example, a Ziegler catalyst system comprising (a) a solid catalyst component containing magnesium, titanium, halogen and an electron donor as essential components, (b) an organoaluminum compound, and (c) an electron donor. Can be produced by polymerization. It can also be produced similarly using a metallocene catalyst.

The amount of polyethylene added is usually 0.1 to 20 parts by mass, preferably 0.1 to 100 parts by mass in total of the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B). -15 parts by mass, more preferably 0.1-10 parts by mass. When the addition amount of polyethylene is in the above range, an inflation film excellent in transparency, surface gloss and mechanical strength can be obtained.

<Crystal nucleating agent>
The propylene polymer composition containing the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B) according to the present invention may contain a crystal nucleating agent as necessary. . By containing the crystal nucleating agent, the mechanical strength, transparency and surface gloss of the resulting inflation film are increased.

  As the crystal nucleating agent, commercially available ones can be used without particular limitation, but crystal nucleating agents mainly composed of metal salts of rosins, sorbitol-based crystal nucleating agents and aromatic organic phosphoric acids. Examples of the nucleating agent include ester metal salts, saturated fatty acid amides or ethylene bis (amides), unsaturated fatty acid amides or ethylene bis (amides), or combinations thereof. The use of (amide) or organophosphate metal salt is preferred from the viewpoint of miscibility with the propylene polymer composition.

The addition amount of the crystal nucleating agent is usually 0.03 to 1 part by mass, preferably 0 with respect to 100 parts by mass in total of the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B). 0.1 to 0.5 parts by mass, more preferably 0.15 to 0.4 parts by mass. When the addition amount of the crystal nucleating agent is in the above range, an inflation film excellent in transparency and surface gloss can be obtained.

<Various additives>
The propylene-based polymer composition according to the present invention includes, as necessary, a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an anti-slip agent, an anti-blocking agent, an antifogging agent, a lubricant, a pigment, a dye, and aging. You may mix | blend additives, such as an inhibitor, a hydrochloric acid absorber, and antioxidant, in the range which does not impair the objective of this invention.

[Propylene-based polymer composition]
The propylene polymer composition according to the present invention comprises a syndiotactic propylene polymer (A), a propylene / α-olefin copolymer (B) and, if necessary, isotactic polypropylene, polyethylene, a crystal nucleating agent or Other known stabilizers and additives are mixed using a mixer such as a Henschel mixer and then melt kneaded and granulated with an extruder, or melt kneaded with a roll, Banbury mixer, pressure kneader, Brabender, etc. It can manufacture by the method to do. Further, the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B) may be separately granulated by an extruder or the like, and the pellets may be blended when processed into a film.

The propylene-based polymer composition obtained as described above has a very fine crystal structure, is excellent in moldability, heat resistance, transparency and surface gloss, and is excellent in scratch resistance.
[Inflation film]
The blown film of the present invention is obtained by air-cooled blown molding of a propylene polymer composition.

  Air-cooled inflation molding is widely used in the production of polyolefin resin films. The raw material is melted by an extruder, the molten resin is extruded into a tube shape through an annular die, and is nipped by a pinch roll. The gas is sealed inside the tube through the hole provided inside the die, or the internal gas is circulated while keeping the volume of gas inside the tube constant (the shape of the bubble is constant), and the size is adjusted to the product size. While blowing up, air supplied from a blower or the like is blown from the air ring to the outer surface of the melting tube to cool and solidify to form bubbles, which are taken up by a take-up machine.

As the inflation molding machine used in the present invention, any known type can be used, but a machine including the following elements and capable of taking specific molding conditions is preferable.
(1-1) Extruder Although various known extruders can be used as the extruder, it is preferable to use a single screw extruder in order to keep the resin temperature low and obtain stable discharge. As the screw shape used in single screw extruders, the types used for normal polyolefin extrusion can be widely used. However, in order to stabilize plasticization, unmelted materials such as barrier type screws and mudock type mixing are generated. A difficult shape is preferred.
(1-2) Die Various die dies used for inflation molding can be used as the die. However, it is preferable to use a spiral mandrel die with less weld and excellent thickness uniformity.
(1-3) Molding temperature Although it does not specifically limit as a temperature which shape | molds the inflation film of this invention, It is preferable to take the range of 160-250 degreeC.
(1-5) Air ring The air ring is very important for cooling and solidifying the film. In the present invention, a well-known air ring for inflation molding which is usually used can be widely used. Among these air rings, the type that can be used particularly preferably is a type in which a plurality of annular slits, called dual or multi-slit types, for blowing out air are provided, and the stabilization of bubbles is promoted by a chamber between the slits. is there. Moreover, it is more preferable that the chamber is provided in the upper part from the viewpoint of improving the cooling efficiency and the bubble stability.
(1-6) Film-forming speed The film-forming speed is determined by the film thickness and width and the amount of extrusion, and can be adjusted within a range where film-forming stability can be maintained. Generally, in air-cooled inflation molding, it is 1 to 150 m / min, preferably 1 to 100 m / min, more preferably 1 to 50 m / min.

In addition, that the moldability is excellent in inflation molding means that the time until solidification from a molten state is short. When the moldability is good, the molding cycle performance, shape stability, long-term productivity, etc. are excellent.

  About the inflation film of this invention, the internal haze value (henceforth "physical property (1)") measured by 50 micrometers thickness is 2% or less normally, Preferably it is 1.8% or less, More preferably, it is 1.5% or less. It is. When the internal haze is in the above range, the blown film of the present invention has excellent transparency and surface gloss. The inflation film of the present invention obtained by using the propylene-based polymer composition has an entanglement number of polymer molecular chains due to the characteristics of the syndiotactic propylene polymer (A), particularly entanglement of molecular chains in the amorphous part. The number is very large. For this reason, crystal size becomes very small and it has the outstanding transparency. The measuring method of internal haze is shown below.

Using an inflation film piece having a thickness of 50 μm, the film was measured with a digital turbidimeter “NDH-20D” manufactured by Nippon Denshoku Industries Co., Ltd., and the average value was obtained three times.
When the physical property (1) is satisfied, the inflation film of the present invention is preferable because it has excellent transparency.

  The gloss (hereinafter also referred to as “physical property (2)”) at an incident angle of 20 ° of the inflation film of the present invention is usually 120% or more, preferably 130% or more, more preferably 140% or more. When the gloss at an incident angle of 20 ° is in the above range, the blown film of the present invention has excellent surface gloss. The gloss measurement method is shown below.

In accordance with JIS K 7105, Suga Test Instruments Co., Ltd. Digital Variable Glossmeter UGV-
The average value of the data of 5 points measured under the condition of an incident angle of 20 ° using 5D was defined as gloss (glossiness).

The test piece used in the measurement of the internal haze value and the gloss was a 30 mmφ inflation molding machine equipped with a 50 mmφ circular die at an extruder temperature of 200 ° C., a die temperature of 200 ° C., and a take-off speed of 1.5 m / min. It is a film having a thickness of 50 μm formed while cooling with air.

When satisfying the physical property (1) and the physical property (2) at the same time, the blown film of the present invention is preferable because both high transparency and high surface gloss can be achieved.
The needle penetration temperature (also referred to as a softening point determined by TMA) (hereinafter also referred to as “physical property (3)”) measured for the propylene-based polymer composition according to the present invention is usually 145 ° C. or higher, preferably It is 147 ° C, more preferably 150 ° C or higher. When the needle entry temperature is in the above range, the inflation film of the present invention has excellent heat resistance. The method for measuring the needle entry temperature is shown below.

Using Seiko's SS-120 or TA Instrument's Q-400, the heating rate is 5 ° C.
A flat indenter having a diameter of 1.8 mm was pressed against a 1 mm thick press sheet test piece at a pressure of ² kgf / cm ² under the conditions of / min, and the needle entry temperature (° C.) was determined from the TMA curve.

When the physical property (1), physical property (2) and physical property (3) are satisfied at the same time, the inflation film of the present invention is more preferable because it has excellent transparency, surface glossiness and heat resistance.
The tensile elastic modulus (hereinafter also referred to as “physical property (4)”) of the propylene-based polymer composition according to the present invention is usually 100 to 2000 MPa, preferably 200 to 1500 MPa, and more preferably 400 to 1000 MPa. The method for measuring the tensile modulus is shown below.

In accordance with JIS K6301, a dumbbell-shaped JIS No. 3 test piece was punched out from a 1 mm thick press sheet to obtain an evaluation sample. For the measurement, for example, using an Instron tensile tester Inston 1123, the measurement was performed at 23 ° C. with a span interval of 30 mm and a pulling speed of 30 mm / min, and an average value of three times was taken.

  In addition, the test piece used for the measurement of the needle entry temperature and the tensile modulus was preheated at 200 ° C. for 5 to 10 minutes, molded in 1 to 2 minutes under 10 MPa pressure, and then pressurized under 10 MPa. The sheet obtained by cooling to 20 ° C.

  When the physical properties (1), physical properties (2), physical properties (3) and physical properties (4) are simultaneously satisfied, the resulting inflation film has excellent heat resistance, transparency, surface glossiness and moldability.

  That is, it is preferable that at least the physical property (1) satisfies the above range among the physical properties (1) to (4), and it is more preferable that the inflation film of the present invention satisfies the physical properties (1) to (2) at the same time. More preferably, the physical properties (1) to (3) are simultaneously satisfied, and it is particularly preferable that the physical properties (1) to (4) are simultaneously satisfied.

In the case of the above-mentioned propylene polymer composition, the half crystallization time (t _1/2 ) obtained from the isothermal crystallization measurement at 110 ° C. by a differential scanning calorimeter (DSC) is preferably 1000 s.
ec or less, more preferably 500 sec or less. Propylene polymer composition according to the present invention contains a specific syndiotactic propylene polymer (A) and the propylene · alpha-olefin copolymer (B), t _1/2 as compared with the conventional leap Therefore, it can be molded by the same molding method as that of normally used isotactic polypropylene.

The half crystallization time (t _1/2 ) obtained by isothermal crystallization measurement is 50% calorie when the area between the DSC calorie curve and the baseline in the isothermal crystallization process is the total calorie. It is the time of arrival (see New Polymer Experiment Lecture 8 Physical Properties of Polymers (Kyoritsu Publishing Co., Ltd.) The half crystallization time (t _1/2 ) is measured as follows. That is, about 5.00 mg of a sample is packed in a special aluminum pan, and DSCPyris 1 or DSC 7 manufactured by PerkinElmer is used.
The temperature was raised from 0 ° C. to 200 ° C. at 320 ° C./min and held at 200 ° C. for 5 minutes, and then the temperature from 200 ° C. to isothermal crystallization temperature 110 ° C. was lowered at 320 ° C./min and the temperature was maintained at 110 ° C. It was obtained from the DSC curve obtained as described above. The half crystallization time (t _1/2 ) was determined by setting the isothermal crystallization process start time at 110 ° C. (time when the temperature reached from 110 ° C. to 110 ° C.) as t = 0. The propylene-based polymer composition used in the present invention can determine t _1/2 as described above, but when not crystallizing at 110 ° C., it is conveniently measured at an isothermal crystallization temperature of 110 ° C. or less. The half crystallization time (t _1/2 ) is obtained from the extrapolated value.

[Inflation film]
The inflation film of the present invention comprises a syndiotactic propylene polymer (A), a propylene / α-olefin copolymer (B) and, if necessary, the above isotactic polypropylene, polyethylene and various additives. It consists of a propylene polymer composition. The inflation film of the present invention may be formed of a single layer or a multilayer of two or more layers. For example, when the inflation film is formed of two layers, one layer is formed of the propylene-based polymer composition according to the present invention, and the other layer forms the first layer. Or a propylene polymer composition having physical properties different from those of the propylene polymer composition according to the present invention used in the first layer.

Examples of the different resin include polyamide (nylon 6, nylon 66, nylon 12 and copolymer nylon, etc.), ethylene / vinyl alcohol copolymer, polyester (polyethylene terephthalate, etc.), and modified polyolefin.

The inflation film of the present invention is produced by a conventionally known air-cooled inflation molding method.
The inflation film of the present invention is suitably used for applications such as optical films, packaging films, printing, laminating and medical supplies.

〔Example〕
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples. In the examples, each physical property was measured as follows.

(Physical property measurement method)
<Intrinsic viscosity [η]>
It measured at 135 degreeC using the decalin solvent. That is, about 20 mg of polymer powder, pellets, or resin mass is dissolved in 15 ml of decalin, and the specific viscosity η _sp is measured in an oil bath at 135 ° C. After adding 5 ml of decalin solvent to this decalin solution for dilution, the specific viscosity η _sp is measured in the same manner. This dilution operation was further repeated twice, and the value of η _sp / C when the concentration (C) was extrapolated to 0 was determined as the intrinsic viscosity (see the following formula).

[Η] = lim (η _sp / C) (C → 0)
<Amount of soluble part of n-decane>
200 ml of n-decane was added to 5 g of a syndiotactic propylene polymer (A) sample, and the polymer was heated and dissolved at 145 ° C. for 30 minutes. The resulting solution was allowed to cool to 20 ° C. over about 3 hours and left for 30 minutes. Thereafter, the precipitate (n-decane insoluble part) was filtered off. The filtrate was put in about 3 times the amount of acetone to precipitate the components dissolved in n-decane. The precipitate was filtered off from acetone and then dried. Even when the filtrate side was concentrated to dryness, no residue was observed. The amount of n-decane soluble part was determined by the following formula.

n-decane soluble part amount (wt%) = [precipitate weight / sample weight] × 100
<Molecular weight distribution (Mw / Mn)>
The molecular weight distribution (Mw / Mn) was measured as follows using a gel permeation chromatograph Alliance GPC-2000 manufactured by Waters. The separation columns are two TSKgel GNH6-HT and two TSKgel GNH6-HTL, the column size is 7.5 mm in diameter and 300 mm in length, the column temperature is 140 ° C., and the mobile phase is o -Using dichlorobenzene (Wako Pure Chemical Industries) and 0.025% by weight of BHT (Takeda Pharmaceutical) as an antioxidant, moving at 1.0 ml / min, sample concentration is 15 mg / 1
The volume of sample injection was 500 μL, and a differential refractometer was used as a detector. The standard polystyrene used was manufactured by Tosoh Corporation for molecular weights of Mw <1000 and Mw> 4 × 10 ⁶ , and used by Pressure Chemical Co. for 1000 ≦ Mw ≦ 4 × 10 ⁶ .

<Ethylene, propylene and α-olefin content in polymer>
Quantification of ethylene, propylene and α-olefin content is made by JEOL JNM
It measured as follows using GX-400 type | mold NMR measuring apparatus. A 0.35 g sample is dissolved by heating in 2.0 ml of hexachlorobutadiene. The solution is filtered through a glass filter (G2), 0.5 ml of deuterated benzene is added, and the solution is placed in an NMR tube having an inner diameter of 10 mm, and ¹³ C-NMR measurement is performed at 120 ° C. The number of integration is 8,000 times or more. The composition of ethylene, propylene and α-olefin was quantified by the obtained ¹³ C-NMR spectrum.

<Melting point (Tm) and heat of fusion (ΔH) of component (A)>
Using a DSCPyris 1 or DSC7 manufactured by PerkinElmer, under a nitrogen atmosphere (20
ml / min), about 5 mg of sample was heated to 200 ° C. and held for 10 minutes, and then cooled to 30 ° C. at 10 ° C./min. After maintaining at 30 ° C. for 5 minutes, the melting point was calculated from the peak of the crystal melting peak when the temperature was raised to 200 ° C. at 10 ° C./min, and the heat of fusion was calculated from the integrated value of the peak.

When two peaks are observed in the propylene polymer described in the examples, the low temperature side peak is Tm ₁ and the high temperature side peak is Tm ₂ .
Tm defined in the appended claims 1 (a) is a Tm _2.

<Glass point transfer (Tg) and melting point (Tm) of component (B)>
Using a DSC manufactured by Seiko Instruments Inc., about 5 mg of sample was packed in a measurement aluminum pan, heated to 200 ° C. at 100 ° C./min, held at 200 ° C. for 5 min, and then −150 ° C. at 10 ° C./min. Then, the temperature was obtained from an endothermic curve that was raised to 200 ° C. at 10 ° C./min.

<Stereoregularity rrrr>
Stereoregularity (rrrr) was calculated from ¹³ C-NMR spectrum measurement.
<Melt flow rate (MFR)>
The MFR of the syndiotactic propylene polymer (A) and the propylene / α-olefin copolymer (B) was measured at 230 ° C. under a load of 2.16 kg according to JIS K-6721.

<Density>
The density was measured according to ASTM D1505.
<Needle entry temperature>
As for the needle entry temperature, a SS-120 manufactured by Seiko Co., Ltd. was used under the conditions of a heating rate of 5 ° C./min.
An 8 mmφ planar indenter was pressed against a 1 mm thick press sheet test piece at a pressure of ² kgf / cm ² and determined from a TMA curve.

<Tensile modulus>
In accordance with JIS K6301, a dumbbell-shaped JIS No. 3 test piece was punched out from a 1 mm thick press sheet to obtain an evaluation sample. The tensile elastic modulus was measured at 23 ° C. using an Instron tensile tester Inston 1123 at a span interval of 30 mm and a tensile speed of 30 mm / min.

  The 1 mm-thick press sheet test piece used for measuring the needle entry temperature and the tensile elastic modulus was preheated with a propylene polymer composition at 200 ° C. for 5 to 10 minutes using a press molding machine, and then 1 under 10 MPa pressure. It was obtained by molding in ˜2 minutes and cooling to 20 ° C. under a pressure of 10 MPa.

<Internal haze>
Using an inflation film piece having a thickness of 50 μm, the film was measured with a digital turbidimeter “NDH-20D” manufactured by Nippon Denshoku Industries Co., Ltd., and the average value was taken three times.

<Gloss (surface gloss)>
In accordance with JIS K 7105, Suga Test Instruments Co., Ltd. Digital Variable Glossmeter UGV-
Using 5D, the average value of the data of 5 points | pieces which measured the 50-micrometer-thick inflation film at the incident angle of 20 degrees was taken.

[Example of catalyst synthesis]
<Synthesis Example 1>
Dibenzylmethylene (cyclopentadienyl) (3,6-di-t-butylfluorenyl) zirconium dichloride was produced by the method described in Synthesis Example 3 of JP-A-2004-189666.

[Polymerization example]
<Polymerization Example 1> Production of Syndiotactic Propylene Polymer (A-1) 250 ml of toluene was charged into a 500 ml glass autoclave sufficiently purged with nitrogen, propylene at 150 liters / hour, and hydrogen at 0.3. It was circulated in an amount of liter / hour and kept at 25 ° C. for 20 minutes. On the other hand, a magnetic stirrer was placed in a 30 ml-branched flask with a sufficient nitrogen substitution, and 5.00 mmol of a toluene solution of methylaluminoxane (Al = 1.53 mol / l), followed by dibenzylmethylene (cyclopentadienyl). ) 5.0 μmol of a toluene solution of (3,6-di-t-butylfluorenyl) zirconium dichloride was added and stirred for 20 minutes. This solution was added to toluene in a glass autoclave in which propylene and hydrogen had been circulated to initiate polymerization. Propylene gas was continuously supplied at a rate of 150 liter / hour and hydrogen was continuously supplied at a rate of 0.3 liter / hour, polymerization was carried out at 25 ° C. for 45 minutes under normal pressure, and then a small amount of methanol was added to terminate the polymerization. The polymer solution was added to a large excess of methanol to precipitate the polymer and dried under reduced pressure at 80 ° C. for 12 hours. As a result, 2.38 g of polymer was obtained. Polymerization activity is 0.63 kg-PP
[Η] of the obtained polymer is 1.9 dl / g, Tm ₁ = 152 ° C., Tm ₂ = 158 ° C., rrrr = 94%, and Mw / Mn = 2. 0.0. This operation was repeated to obtain the required amount of polymer and used in the examples.

The results are shown in Table 1.
<Polymerization Example 2> Production of Propylene / α-Olefin Copolymer (B-1) After charging 1834 ml of dry hexane and triisobutylaluminum (1.0 mmol) to a 4000 ml polymerization apparatus sufficiently purged with nitrogen at room temperature. The internal temperature of the polymerization apparatus was raised to 70 ° C., and the pressure in the system was increased to 0.66 MPa with propylene, and then the system pressure was adjusted to 1.36 MPa with ethylene. Then di (p-chlorophenyl) methylene (
Toluene solution in which 0.001 mmol of cyclopentadienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride and 0.3 mmol of methylaluminoxane (made by Tosoh Finechem) in contact with aluminum was brought into contact with the polymerizer was added. Polymerization was carried out for 15 minutes while maintaining the internal temperature at 70 ° C. and the internal pressure at 1.36 MPa with ethylene, and 20 ml of methanol was added to terminate the polymerization. After depressurization, the polymer was precipitated from the polymerization solution in 4 liters of methanol and dried under vacuum at 130 ° C. for 12 hours. The obtained polymer was 105 g, MFR was 1.0 (g / 10 min), and [η] = 2.5 (dL / g) measured in decalin at 135 ° C. The rr ₁ value was 78%.

  The results are shown in Table 1.

[Example 1]
(1) Pelletization With respect to 100 parts by weight of the polymer (A-1) obtained in Polymerization Example 1, 0.2 part by weight of 3,5-di-t-butyl-4-hydroxytoluene as an antioxidant, 0.2 parts by weight of tetrakis [methylene-3 (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane as an antioxidant, 0.01 parts by weight of calcium stearate as a neutralizer, Using a twin screw extruder, the mixture was melt-kneaded at a resin temperature of 200 ° C. and pelletized.

(2) Sheet molding The pellet obtained above was subjected to an extruder temperature of 200 ° C, a die temperature of 200 ° C, and a take-off speed of 1.5 m / m using a 30 mmΦ inflation molding machine equipped with a 50 mmΦ circular die.
In and air-cooled to form a film, a film having a thickness of 50 μm was obtained.

The opening of the film was good.
Table 2 shows the physical properties measured for the obtained pellets and film.
[Example 2]
In Example 1, it carried out like Example 1 except having mix | blended 0.2 weight part of ethylene (bis) stearamide as a crystal nucleating agent.

The opening of the film was good.
The results are shown in Table 2.
Example 3
In Example 1, it carried out like Example 1 except having mix | blended isotactic polypropylene (J139; Prime polymer company make) in the ratio shown in Table 2.

The opening of the film was good.
The results are shown in Table 2.
Example 4
In Example 1, it carried out like Example 1 except having mix | blended polyethylene (HZ2200J; made by Prime Polymer Co., Ltd.) in the ratio shown in Table 2.
The opening of the film was good.

The results are shown in Table 2.
Example 5
In Example 1, it carried out like Example 1 except having mix | blended 0.3 weight part of Adekastab NA-21 (made by Asahi Denka Kogyo Co., Ltd.) as a crystal nucleating agent.

The opening of the film was good.
The results are shown in Table 2.
Example 6
In Example 1, it carried out like Example 1 except having blended 90 parts by weight of polymer (A-1) and 10 parts by weight of propylene / ethylene copolymer (B-1).

The opening of the film was good.
The results are shown in Table 2.
[Comparative Example 1]
In Example 1, it carried out similarly to Example 1 except having used syndiotactic polypropylene (trade name: Total Polypropylene 1251) (C-1) by Total instead of polymer (A-1).

The film was difficult to open and the transparency and surface gloss could not be measured.
The results are shown in Table 2.

[Comparative Example 2]
In Example 1, it carried out like Example 1 except having used the polypropylene (brand name: F-327) (D-1) by a prime polymer company instead of the polymer (A-1).

The results are shown in Table 2.
[Comparative Example 3]
In Example 1, it carried out like Example 1 except having used the polypropylene (brand name: F113G) (E-1) by Prime Polymer instead of polymer (A-1).

The results are shown in Table 2.
[Comparative Example 4]
In Example 1, it carried out like Example 1 except having blended 20 parts by weight of polymer (A-1) and 80 parts by weight of propylene / ethylene copolymer (B-1).
The film was difficult to open and the transparency and surface gloss could not be measured.

  The results are shown in Table 2.

Claims (7)

100-50 parts by weight of syndiotactic propylene polymer (A),
0-50 parts by weight of propylene / α-olefin copolymer (B) (however, (A) and (B)
And 100 parts by weight. And the syndiotactic propylene polymer (A) satisfies the following requirement (a), and the propylene / α-olefin is obtained by subjecting the propylene polymer composition to air-cooled inflation molding. A blown film, wherein the copolymer (B) satisfies the following requirement (b).
(A): The syndiotactic pentad fraction (rrrr fraction) measured by ¹³ C-NMR is 85% or more, and the melting point (Tm) obtained from DSC is 145 ° C. or more, which is derived from propylene. The structural unit is contained in an amount exceeding 90 mol% (however, the total amount of the structural units in the syndiotactic propylene polymer (A) is 100 mol%).
(B): Containing structural units derived from propylene in an amount of 55 to 90 mol%, and 10 to 45 mol% of structural units derived from an α-olefin having 2 to 20 carbon atoms (excluding propylene) (however, The total of the structural unit derived from propylene and the structural unit derived from an α-olefin having 2 to 20 carbon atoms (excluding propylene) is 100 mol%), and in JIS K-6721 The MFR measured at 230 ° C. and a 2.16 kg load is in the range of 0.01 to 100 g / 10 minutes, and at least one of the following requirements (b-1) and (b-2) is satisfied. Fulfill.
(B-1): The syndiotactic triad fraction (rr fraction) measured by ¹³ C-NMR method is 60% or more.
(B-2): The intrinsic viscosity [η] (dL / g) measured in 135 ° C. decalin and the MFR (g / 10 minutes, 230 ° C., 2.16 kg load) satisfy the following relational expression.
1.50 × MFR ^(-0.20) ≦ [η] ≦ 2.65 × MFR ^(-0.20) (1) The inflation film according to claim 1, wherein an internal haze value measured at a thickness of 50 μm is 2% or less. (1) The internal haze value measured at 50 μm thickness is 2% or less,
(2) The inflation film according to claim 1 or 2, wherein the gloss at an incident angle of 20 ° measured in accordance with JIS K 7105 is 120% or more. (1) The internal haze value measured at 50 μm thickness is 2% or less,
(2) The gloss at an incident angle of 20 ° measured in accordance with JIS K 7105 is 120% or more,
(3) The inflation film according to any one of claims 1 to 3, wherein a needle entry temperature of the propylene polymer composition measured in accordance with JIS K 7197 is 145 ° C or higher. (1) The internal haze value measured at 50 μm thickness is 2% or less,
(2) The gloss at an incident angle of 20 ° measured in accordance with JIS K 7105 is 120% or more,
(3) The needle entry temperature of the propylene polymer composition measured in accordance with JIS K 7197 is 145 ° C or higher,
(4) The inflation film according to any one of claims 1 to 4, wherein the propylene-based polymer composition measured in accordance with JIS K6301 has a tensile modulus in a range of 100 to 2000 MPa.   The intrinsic viscosity [η] measured in decalin at 135 ° C. of the syndiotactic propylene polymer (A) is in the range of 0.1 to 10 dL / g, and the heat of fusion (ΔH determined by a differential scanning calorimeter (DSC) ) Is 40 mJ / mg or more, The inflation film according to claim 1. 7. The molecular weight distribution (Mw / Mn) obtained by gel permeation chromatography (GPC) of the propylene / α-olefin polymer (B) is 3.5 or less. The inflation film described in 1.