JPH08157660A - Polypropylene composition - Google Patents

Abstract

PURPOSE: To obtain a polypropylene composition improved in transparency and a mapping property, having excellent processability, and not causing problems such as the roughness of sheet edges, when a raw sheet is extruded on the production of an oriented film, and the breakage of the sheet, the irregular orientation of the film and the orientation breakage of the film, when the sheet is oriented, and further to obtain a polypropylene oriented sheet. CONSTITUTION: This polypropylene composition comprises crystalline polypropylene, 1-10000ppm of a >=5C branched α-olefin polymer such as 3- methyl-1-butene polymer or 3-methyl-1-pentene polymer, and 50-40000ppm of talc having an average particle diameter of 0.1-10μm. An at least monoaxially oriented polypropylene oriented film comprising the polypropylene composition is prepared.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene composition and a stretched film comprising the polypropylene composition.

[0002]

2. Description of the Related Art Polypropylene stretched films, particularly polypropylene biaxially stretched films, are widely used for packaging materials and the like because of their excellent mechanical and optical properties. However, due to the high crystallinity of polypropylene, these polypropylene stretched films are generally inferior in transparency and image clarity to other highly transparent thermoplastic resins such as polystyrene and polyvinyl chloride.

Several proposals have been made so far in an attempt to improve the transparency of a polypropylene stretched film. For example, by adding an organic nucleating agent such as a sorbitol derivative, an alkali metal salt of an aromatic carboxylic acid, or an aluminum salt to polypropylene, the spherulites of the sheet extruded during film formation become smaller and uniform. It is known that the transparency of the film is improved (for example, JP-A-58-80392 and JP-A-55-12460).

However, these organic nucleating agents are
There is a problem that bleeding occurs from polypropylene during extrusion and causes roll contamination, odor is generated during processing, and the nucleating agent bleeds even when a film or the like is stored for a long period of time. Further, the aromatic carboxylic acid salt itself or its hydrolyzate reacts with other additives, thereby deteriorating the original performance of the additive and coloring polypropylene.

On the other hand, attempts have been made to improve the transparency of polypropylene by incorporating a branched α-olefin polymer having 5 or more carbon atoms (Japanese Patent Publication No. 324/324).
30 publication). These branched α-olefin polymers are
Unlike the organic nucleating agent, problems such as roll stains do not occur during film formation, and the stretched film is excellent in improving transparency and image clarity.

However, the branched α in polypropylene
-When the content of the olefin polymer is more than 1 ppm, the surface of the raw sheet obtained by extrusion molding becomes rough during the molding of the polypropylene stretched film, and the transparency and image clarity are lowered, and There is a problem that wavy or saw-toothed roughness is generated at the edge portion, which causes a clip error in tenter stretching, resulting in uneven stretching and tearing of the film in transverse stretching.
Further, if the edge portion is roughened in a saw-tooth shape, the stretch breakage of the sheet occurs during the longitudinal stretching, and there is a problem in the formability of the stretched film.

[0007]

As described above, conventionally, attempts have been made to improve the transparency and image clarity of a polypropylene stretched film by the above-mentioned method, but the moldability of the stretched film is still satisfactory. It wasn't going to happen. Therefore, an object of the present invention is to have excellent transparency and image clarity, and at the time of forming a stretched film, does not cause edge roughness of the sheet during extrusion of the original sheet,
It is an object of the present invention to provide a polypropylene composition and a polypropylene stretched film which have good moldability and are free from breakage of the sheet during longitudinal stretching and uneven stretching or tearing of the film during transverse stretching.

[0008]

From these viewpoints, the present inventors have made earnest studies on a polypropylene stretched film having improved transparency, image clarity, and stretched film moldability, and as a result, surprisingly, crystalline polypropylene was obtained. By a simple method of containing a branched α-olefin polymer having 5 or more carbon atoms and talc in a small amount, transparency and image clarity of the polypropylene stretched film are remarkably improved, and the edge of the sheet is roughened during the stretched film molding. The inventors have found that the moldability is excellent without the occurrence of such problems, and have completed the present invention.

That is, the present invention relates to crystalline polypropylene, branched α-olefin polymers 1 to 10 having 5 or more carbon atoms.
It is a polypropylene composition comprising 000 ppm and talc having an average particle size of 0.1 to 10 μm and 50 to 4000 ppm, and a polypropylene stretched film comprising the polypropylene composition and stretched at least uniaxially.

The crystalline polypropylene used in the present invention may be a homopolymer of propylene, a random copolymer of propylene and other α-olefin, or a mixture thereof. Examples of the α-olefin include ethylene, 1-butene, 1-pentene,
1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 4-methyl-1-pentene and the like can be mentioned, and the content of these α-olefins is 10 mol% or less. Are preferred for maintaining crystallinity.

The crystalline polypropylene used in the present invention is crystalline and generally has an isotactic pentad fraction of 0.85 or more. The isotactic pentad fraction as used in the present invention means A. Zambilli et al., Macromolecules, 13 , 267.
Propylene unit 5 quantified based on the assignment of peaks in ¹³ C-NMR spectrum published in (1980)
It is a fraction in which individual pieces have the same stereo configuration.

The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the crystalline polypropylene used in the present invention is not particularly limited, Considering the case of film formation, it is preferably 6 to 20 in order to increase melt tension and improve workability. The molecular weight distribution is a value measured by gel permeation chromatography (hereinafter also referred to as GPC) using o-dichlorobenzene as a solvent,
The calibration curve used is calibrated with standard polystyrene.

The melt flow rate of the crystalline polypropylene used in the present invention is not particularly limited, but it is usually in the range of 0.01 to 100 g / 10 minutes in consideration of the moldability for various stretched films. It is preferably used in the range of 0.1 to 50 g / 10 minutes.

In the present invention, a branched α- having 5 or more carbon atoms
The olefin polymer is a polymer of a branched α-olefin monomer having a polymerizable double bond, and known compounds can be used without any limitation as long as they are such compounds. In the present invention, a homopolymer of a branched α-olefin monomer having 5 or more carbon atoms, a copolymer of the branched α-olefin monomers with each other, and 50 mol% or more of the branched α-olefin monomer and 50 mol% or less of another monomer are used. Copolymers can be preferably used. Particularly, a branched α-olefin monomer which can be preferably used in the present invention has 5 carbon atoms.
-10, specifically, 3-methyl-
1-butene, 3-methyl-1-pentene, 3-ethyl-
1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene,
4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene and the like can be mentioned.

The branched α-olefin polymer having 5 or more carbon atoms having such stereoregularity is generally crystalline,
It has a higher melting point than crystalline polypropylene.
For example, the melting point of poly-3-methyl-1-butene is 270.
℃ or higher, 210 ℃ for poly-3-methyl-1-pentene
That is all. Further, in the branched α-olefin polymer having 5 or more carbon atoms in the present invention, the higher the crystallinity indicating the degree of crystallinity, the higher the transparency and the effect of improving the image clarity. Is preferably 10% or more, more preferably 30% or more, and most preferably 50% or more. Examples of the branched α-olefin polymer having such a high crystallinity include homopolymers of the branched α-olefin monomers described above, branched α-olefin monomers having 5 or more carbon atoms, or other α-olefins. A block copolymer can be preferably used.

Branched α having 5 or more carbon atoms used in the present invention
-The polymerization method of the olefin polymer is not particularly limited as long as the effects of the present invention are not impaired, and for example, the following polymerization methods are used. First, a suitable catalyst is a titanium-based catalyst in which titanium trichloride, titanium tetrachloride or vanadium tetrachloride is supported on a magnesium compound such as magnesium chloride,
Vanadium-based catalysts, generally metallocene-based catalysts and the like consisting of a metallocene compound using a transition metal of Group IV of the periodic table and a coexisting system of methylaluminoxane or alkylaluminum or alkylaluminum halide, and the like, and these are used alone or in combination. May be done. The polymerization method is not particularly limited, such as gas phase polymerization, solution polymerization and bulk polymerization.

Branched α having 5 or more carbon atoms used in the present invention
-The content of the olefin polymer in the crystalline polypropylene must be in the range of 1 to 10,000 ppm.
〜5000ppm is preferable, and further 50〜
More preferably, it is 2000 ppm. When the content of the branched α-olefin polymer is less than 1 ppm, the effect of improving transparency and image clarity is not seen. Conversely, 10,000p
When it exceeds pm, there are problems such as surface roughness and edge roughness of the sheet in the extrusion process of the original sheet, which lowers transparency and image clarity of the stretched film and causes uneven stretching and tearing of the stretched film. Occurs. The branched α-olefin polymer having 5 or more carbon atoms has a branched α-olefin having 5 or more carbon atoms.
When a copolymer of an olefin monomer and another monomer is used, the weight of the polymerization component based on the branched α-olefin monomer needs to be within the above range. In the present invention, ppm is based on weight.

The average particle size of talc used in the present invention must be in the range of 0.1 to 10 μm, and 0.5 to
The thickness is preferably 8.0 μm, and more preferably 1.0 to 7.
It is more preferably 0 μm. If the average particle size of talc is less than 0.1 μm, talc undergoes secondary agglomeration to increase the agglomerated particle size, resulting in a decrease in transparency and fish eyes, which deteriorates the appearance of the film, which is not preferable. . On the contrary, when the average particle diameter exceeds 10 μm, voids are often generated during stretching of the film, and the transparency of the film is lowered, which is not preferable. The method for measuring the average particle size of talc used in the present invention is not particularly limited,
A method using a Coulter counter, an electron microscope or the like is exemplified. As the talc used in the present invention, known products such as crushed products of natural products or synthetic products are used without limitation, and talc having high crystallinity and high crystallinity for polypropylene is preferred.

The content of talc in the crystalline polypropylene used in the present invention must be in the range of 50 to 4000 ppm, preferably 80 to 2000 ppm, more preferably 100 to 1000 ppm. If the talc content is less than 50 ppm,
The sufficient nucleation effect of talc cannot be obtained, and the edge of the raw sheet is roughened. On the other hand, when it exceeds 4000 ppm, the transparency of the film is lowered and the appearance is deteriorated due to the generation of voids.

The method of incorporating the branched α-olefin polymer having 5 or more carbon atoms and talc into the crystalline polypropylene is not particularly limited, and various mixing methods can be adopted. Specifically, the branched α-olefin polymer obtained by polymerization in advance and talc are simultaneously added to the crystalline polypropylene, and a screw extrusion kneader such as a single screw extruder or a twin screw extruder, a Banbury mixer. , A method of mixing using a continuous mixer, a mixing roll or the like, more preferably, after prepolymerizing the branched α-olefin, homopolymerization of propylene or copolymerization of propylene and other α-olefins. A method in which talc is added after the composition containing the branched α-olefin polymer is prepared by carrying out the method can be mentioned.

Further, the number of carbon atoms is 5 by the method as shown above.
After obtaining a composition containing the above branched α-olefin polymer at a high concentration, the composition was used as a masterbatch and diluted with another crystalline polypropylene at a dilution ratio of 2 to 1000 times (carbon number). By diluting the branched α-olefin polymer content of 5 or more by 0.5 to 0.001 times), the target branched α-olefin polymer content can be obtained. The dilution ratio of the masterbatch is generally about 20 times, but in the present invention, the transparency and image clarity of the stretched film can be sufficiently improved even though it depends on the masterbatch concentration.

In the polypropylene composition and the polypropylene stretched film of the present invention, if necessary, an antioxidant, a chlorine scavenger, a heat stabilizer, an antistatic agent, an antifogging agent, an ultraviolet absorber, a lubricant, an antiblocking agent. Additives such as pigments, other resins and fillers may be added as long as the effects are not impaired.

The thickness of the polypropylene stretched film of the present invention is not particularly limited, but it is usually 3 to 150 μm for a biaxially stretched film and 10 to 25 for a uniaxially stretched film.
It is preferably 4 μm. The polypropylene stretched film of the present invention is stretched in at least a uniaxial direction. Of course, it may be biaxially stretched. Although the stretching ratio is not particularly limited, it is generally 4 to 10 times in the uniaxial direction, and in the case of biaxial stretching, it is generally stretched in the range of 4 to 15 times in the direction perpendicular thereto. Is.

One or both sides of the polypropylene stretched film of the present invention may be subjected to surface treatment such as corona discharge treatment, if necessary. Further, for the purpose of imparting a function such as heat sealability, a layer made of another resin having a lower melting point than the crystalline polypropylene used in the present invention may be laminated on one side or both sides. The method for laminating other resins is not particularly limited, but a coextrusion method, a laminating method, etc. are preferable.

As the method for producing the polypropylene stretched film of the present invention, known methods can be adopted without any limitation. For example, as a method for producing a stretched film by a sequential biaxial stretching method by a tenter method, the polypropylene composition is molded into a sheet or a film by a T-die method, an inflation method or the like, and then supplied to a longitudinal stretching device and heated. Longitudinal stretching of 4 to 10 times at a roll temperature of 120 to 170 ° C., and then using a tenter, a tenter temperature of 130 to
A method of transversely stretching 4 times to 15 times at 180 ° C. is preferable, and a method of performing heat treatment at 80 to 180 ° C. while allowing relaxation of 0 to 25% in the transverse direction as needed can be mentioned. Of course, the stretching may be performed again after these stretchings, and in the longitudinal stretching, stretching methods such as multi-stage stretching and rolling can be combined. Also, a stretched film can be obtained by stretching only uniaxially.

[0026]

According to the present invention, the transparency and image clarity of a polypropylene stretched film are improved, and the surface of the sheet is not roughened or the edges are roughened in the process of forming a raw sheet when molding the stretched film. A polypropylene composition having excellent processability can be obtained without problems such as breakage of stretch of the sheet, deterioration of thickness accuracy due to uneven stretching of the film, and breakage of stretch. In the polypropylene composition and polypropylene stretched film of the present invention,
It is not clear why the inclusion of a small amount of talc improves the moldability of a crystalline polypropylene containing a branched α-olefin polymer having 5 or more carbon atoms into a stretched film, but the present inventors have the following. From the analysis results of, we think as follows.

A detailed analysis of the orientation mode of the polypropylene crystals of the crystalline polypropylene raw sheet containing a branched α-olefin polymer having 5 or more carbon atoms by the wide-angle X-ray diffraction method shows that the growth axis of the polypropylene crystals, that is, a *
It was found that the axis was strongly oriented perpendicular to the sheet surface (sheet thickness direction). That is, when the original sheet is rotated at high speed about an axis perpendicular to the sheet surface and X-rays are incident from the direction perpendicular to the sheet surface to measure the diffraction intensity, 040 reflection from the polypropylene crystal (2θ = 1
7.1 °) is strongly observed. Peak separation of the measured X-ray diffraction profile was performed, and the peak intensity ratio of 040 reflection and 111 reflection (2θ = 21.4 °) I (040) / I (111)
Is 2 to 5, and this peak intensity ratio increases as the content of the branched α-olefin polymer increases. Z. Mencik (Z. Mencik, Journ
al of Macromolecule Scie
nce, Physics B6 , 101 (197)
According to 2)), when the polypropylene crystals are perfectly randomly oriented, the peak intensity ratio is I (040) / I (111).
= 1.52. From this, in the crystalline polypropylene raw sheet containing the branched α-olefin polymer, the (040) plane of the polypropylene crystals is perpendicular to the sheet surface,
That is, it can be seen that the b axis of the crystal is strongly oriented parallel to the sheet surface. Also, since the crystal c-axis (polypropylene molecular chain axis) is oriented in the extrusion direction (parallel to the sheet surface), the a * axis, which is the crystal growth direction, is oriented perpendicular to the sheet surface (sheet thickness direction). It turned out.

From the above, branched α-containing 5 or more carbon atoms
When an olefin polymer is contained in crystalline polypropylene, the polypropylene crystals grow in the thickness direction of the sheet from the chill roll side during cooling and solidification of the molten resin at the time of forming the raw sheet, and at this time, it is opposite to the chill roll side. Since the shrinkage rate on the surface side, the difference in internal stress, etc. become large, the adhesion between the original sheet and the cooling roll deteriorates, uneven cooling and roll separation occur, the original sheet surface becomes rough, and the edge state is It is expected to get worse.

On the other hand, when talc is contained, on the contrary, the peak intensity ratio of 040 reflection and 111 reflection I (040) /
I (111) becomes 1 or less, and the peak intensity ratio decreases as the talc content increases. In the crystalline polypropylene original sheet containing talc, polypropylene crystal (0
It can be seen that the 40) plane is parallel to the sheet surface, that is, the b axis of the crystal is strongly oriented perpendicular to the sheet surface. Therefore, it was found that the a * axis, which is the crystal growth direction, is oriented in the direction parallel to the sheet surface (in the sheet surface). Talc is also known to have a nucleating effect on polypropylene, but in the case of talc-containing crystalline polypropylene, nucleation such as a rise in crystallization temperature similar to that of a branched α-olefin polymer having 5 or more carbon atoms. Even if the effect is seen, the edge portion of the original sheet is not roughened. This means that in the talc-containing system, polypropylene crystals grow in the sheet plane when the molten resin is cooled and solidified during the forming of the original sheet, so that the shrinkage and the change in stress in the thickness direction are small, so the original sheet is It is considered that the adhesion between the sheet and the cooling roll becomes good and the condition of the edge portion does not deteriorate.

Therefore, when a branched α-olefin polymer having 5 or more carbon atoms and talc are contained in crystalline polypropylene, the orientation of the polypropylene crystals of the sheet, that is, the crystal growth direction is controlled by the content and the ratio of both. It turns out that it is possible to do.

Based on the results of the above analysis, the inventors of the present invention incorporated talc into crystalline polypropylene containing a branched α-olefin polymer having 5 or more carbon atoms to obtain a polypropylene crystal in the process of forming a raw sheet. It has been found that by suppressing the growth in the thickness direction of the sheet, it is possible to form a stable sheet without causing edge roughness of the original sheet. Furthermore, the spherulite inside the raw sheet is made smaller and uniform by the nucleating effect of both the branched α-olefin polymer and talc,
It is considered that the transparency and image clarity of the obtained stretched film are further improved.

[0032]

EXAMPLES In order to describe the present invention more specifically, examples and comparative examples will be described below, but the present invention is not limited to these examples. The polypropylene stretched films obtained in the following examples and comparative examples were evaluated by the following methods.

(1) Haze Measured according to JIS K 6714.

(2) Image value An optical comb of 0.1 was used using an image measuring device manufactured by Suga Test Instruments Co., Ltd.
Using 25 mm, the comb direction was made parallel to the transverse stretching method of the biaxially stretched film, and the image value was measured.

Example 1 (Preparation of Titanium Compound) A method for preparing a solid titanium component is described in JP-A-58-38006.
The method was carried out according to the method of Example 1 of the publication. That is,
Anhydrous magnesium chloride 9.5 g, decane 100 ml and 2-ethylhexyl alcohol 47 ml (300 mmo
l) was heated and stirred at 125 ° C. for 2 hours, 5.5 g (37.5 mmol) of phthalic anhydride was added to this solvent,
The mixture was stirred and mixed at 125 ° C. for 1 hour to obtain a uniform solution. After cooling to room temperature, the whole amount was dropwise added to 400 ml (3.6 mmol) of titanium tetrachloride kept at -20 ° C over 1 hour. The temperature of this mixed solution was raised to 110 ° C. over 2 hours, and when it reached 110 ° C., 5.4 ml (25 mmol) of diisobutyl phthalate was added, and the mixture was maintained at the same temperature for 2 hours with stirring. After the completion of the reaction for 2 hours, the solid portion was collected by hot filtration, and the solid portion was resuspended in 2000 ml of titanium tetrachloride, and then heated at 110 ° C. for 2 hours. After the completion of the reaction, the solid part was collected again by hot filtration and thoroughly washed with decane and hexane until no free titanium compound was detected in the washing liquid. The solid titanium catalyst component prepared by the above production method was stored as a heptane slurry.

The composition of the solid titanium catalyst component is titanium 2.
1% by weight, chlorine 57.0% by weight, magnesium 18.0
% By weight and 21.9% by weight of diisobutyl phthalate.

(Preliminary Polymerization of 3-Methyl-1-butene) Purified hexane 6000 was placed in a 10 L polymerization vessel subjected to nitrogen substitution.
ml, triethylaluminum 100 mmol, 10 mmol of solid titanium catalyst component in terms of titanium atom, and then 3-methyl-1-butene as a whole titanium component 10 was added.
It was continuously introduced into the reactor for 2 hours so that the amount was 80 g relative to g. During this period, the temperature was kept at 20 ° C. After 2 hours, the introduction of 3-methyl-1-butene was stopped and the reactor was thoroughly replaced with nitrogen. The solid portion of the obtained slurry was washed 5 times with purified hexane to obtain a titanium catalyst component-containing 3-methyl-1-butene polymer. The weight of the 3-methyl-1-butene polymer at this time was 72 g. The crystallinity determined by X-ray diffraction was 60%.

(Main Polymerization) Nitrogen-Substituted Content 200
After charging 500 kg of propylene into a 0 L polymerization vessel, charged with 1.64 mol of triethylaluminum, 0.164 mol of ethyltriethoxysilane, 0.0082 mol of cyclohexylmethyldimethoxysilane, and 10 L of hydrogen, the internal temperature of the polymerization vessel was changed. The temperature was raised to 65 ° C. Titanium-containing 3-methyl-1-butene with a titanium atom of 0.006
After charging 56 mol, the internal temperature of the polymerization vessel was raised to 70 ° C. and propylene polymerization was carried out for 1 hour. After 1 hour, unreacted propylene was purged to obtain a white granular polymer. The obtained polymer was dried under reduced pressure at 70 ° C.
The total polymer yield was 143 kg. The 3-methyl-1-butene polymer content in the polypropylene containing the 3-methyl-1-butene polymer determined from the yield was 330 ppm. Further, the obtained polypropylene has a melt flow rate (MFR), a pentad fraction, and a molecular weight distribution (Mw /
Mn) is shown in Table 1.

(Granulation) Powder 1 of polypropylene containing 330 ppm of the 3-methyl-1-butene polymer obtained above.
To 100 parts by weight, 0.1 parts by weight of 2,6-di-t-butylhydroxytoluene as an antioxidant, 0.1 parts by weight of calcium stearate as a chlorine scavenger, and 300 ppm of talc having an average particle size of 4.2 μm. Was added and mixed with a Henschel mixer for 5 minutes, then the screw diameter was 65 mmφ
Was extruded at 230 ° C. to pelletize the raw material pellets.

(Molding of Biaxially Stretched Film) A molding experiment of a biaxially stretched film was carried out by the following method using the obtained polypropylene composition pellets. The polypropylene composition pellets were extruded at 280 ° C. using a T-die sheet extruder with a screw diameter of 90 mmφ, and a sheet having a thickness of 2 mm was formed with a cooling roll at 30 ° C. Then, this raw sheet was longitudinally stretched 4.6 times in the longitudinal direction at 150 ° C. by using a tenter type sequential biaxial stretching device, and subsequently 165
After transversely stretching in the tenter at 10 ° C. in the transverse direction by a mechanical ratio of 10 times, the mixture was heat-treated with a relaxation of 8% to form a biaxially stretched polypropylene film having a thickness of 50 μm at a speed of 16 m / min.

The state of the edge roughness of the original sheet during film formation was visually evaluated. The evaluation criteria are as follows.

⊚: The edge portion of the sheet is in a linear shape which is in close contact with the cooling roll and is extremely good. ○: It is slightly separated from the cooling roll, but there is no problem in film forming. Δ: Roughness is wavy ×: Roughness is saw-toothed. The influence on the thickness accuracy of the is measured by Yokogawa Denki's infrared thickness measuring machine W installed between the tenter and the winder.
It was evaluated by the thickness pattern of the film measured using EB GAGE. The evaluation criteria of film thickness accuracy are as follows.

⊚: Less than ± 1 μm ○: ± 1 μm or more and less than 1.5 μm Δ: ± 1.5 μm or more and less than 2 μm ×: ± 2 μm or more Further, continuous operation was carried out for 5 hours, and stretch breakage in the longitudinal stretching of the sheet, tenter The number of stretch breakages of the film was evaluated. Also, the obtained film is
After the lapse of time, the haze and the mapping value were measured. The results are shown in Table 1.
It was shown to.

Examples 2 to 5 Preliminary polymerization of 3-methyl-1-butene was carried out in the same manner as in Example 1 except that the amount of 3-methyl-1-butene introduced and the polymerization time were changed. 3-methyl-
A polypropylene containing 1-butene polymer was obtained. The crystallinity of the 3-methyl-1-butene polymer obtained at this time was 60% as in Example 1. Example 1 was repeated except that the polypropylene containing 3-methyl-1-butene polymer shown in Table 1 was used. The results are shown in Table 1.

Examples 6 to 10 The same polypropylene containing 3-methyl-1-butene polymer as in Example 1 was used, and talc having the average particle size shown in Table 1 was added in the compounding amount shown in Table 1. The procedure was the same as in Example 1 except for the above. The results are shown in Table 1.

Comparative Examples 1 to 7 Comparative Examples 1 to 7 were carried out except that prepolymerization of 3-methyl-1-butene and blending of talc were not carried out, or the respective prepolymerization amounts and blending amounts were the amounts shown in Table 1. The same procedure as in Example 1 was performed, and the results are shown in Table 1.

Examples 11 to 15 In the main polymerization, the crystalline polypropylene (propylene-α-olefin random copolymer) shown in Table 1 was polymerized to show the content of 3-methyl-1-butene polymer in Table 1. Table 1 shows the results obtained in the same manner as in Example 1 except that the average particle size of talc and the addition amount were as shown in Table 1.

Comparative Examples 8 to 12 Comparative Examples 8 to 12 were carried out except that the prepolymerization of 3-methyl-1-butene and the blending of talc were not carried out, or the respective prepolymerization amounts and blending amounts were the amounts shown in Table 1. The same procedure as in Example 11 was performed, and the results are shown in Table 1.

Example 16 (Synthesis of catalyst component containing 3-methyl-1-butene polymer)
100 ml of hexane, 50 mmol of methylaluminoxane and 0.05 mmol of dimethylsilylenebis (methylindenyl) zirconium dichloride were introduced into a glass reactor equipped with a 500 ml stirrer, and the temperature of the system was raised to 60 ° C. Polymerization was started by adding 7.7 g of 3-methyl-1-butene, and the polymerization was carried out at 60 ° C. for 1 hour. The produced solid part was separated by decantation and washed 5 times with 200 ml of hexane to give 4.8 g of a 3-methyl-1-butene polymer and 40 mmo of aluminum.
A solid catalyst component containing 1 and 0.045 mmol of zirconium was obtained. The crystallinity derived from the 3-methyl-1-butene polymer determined by X-ray diffraction was 57%.

(Synthesis of Masterbatch) 3000 ml of toluene and 30 mmol of triisobutylaluminum were introduced into a 5000 ml pressure resistant reactor, and the temperature inside the system was raised to 40 ° C. Then, the above solid catalyst component containing 3-methyl-1-butene polymer was introduced as zirconium into a 0.01 mmol system, and propylene was pressurized to 3 kgG / cm ² to start polymerization, and polymerization was carried out at 40 ° C. for 1 hour. It was The reaction mixture was added to acidic methanol to terminate the polymerization, and the obtained solid was filtered and dried under reduced pressure to obtain 330
g of polymer was obtained. The content of the 3-methyl-1-butene polymer in the polymer was calculated from the 3-methyl-1-butene polymer contained in the solid catalyst component, and the result was 3300 p.
pm.

3-Methyl-1-produced in this way
The crystalline homopolypropylene shown in Table 1 was blended using a masterbatch containing 3300 ppm of butene polymer, and the content of 3-methyl-1-butene polymer was 160 pp.
m polypropylene composition was obtained, and the talc shown in Table 1 was added. The results are shown in Table 1.

[0052]

[Table 1]

Example 17 (Preliminary Polymerization of 3-Methyl-1-pentene) Purified hexane (6000 ml), triethylaluminum (100 mmol), and solid titanium catalyst component (10 mmol in terms of titanium atom) were charged into a nitrogen-substituted 10 L polymerization vessel. After that, 3-
Methyl-1-pentene was continuously introduced into the reactor for 2 hours so that the total amount was 100 g with respect to 10 g of titanium component. During this period, the temperature was kept at 20 ° C. Two hours later,
The introduction of 3-methyl-1-pentene was stopped and the reactor was thoroughly purged with nitrogen. The solid portion of the obtained slurry was washed 5 times with purified hexane to obtain titanium-containing 3-methyl-1-
A pentene polymer was obtained. The weight of the 3-methyl-1-pentene polymer at this time was 83 g. The crystallinity determined by X-ray diffraction was 58%.

Main polymerization of propylene was carried out using the titanium-containing 3-methyl-1-pentene polymer obtained above to obtain polypropylene having the content of 3-methyl-1-pentene polymer shown in Table 2. The same procedure as in Example 1 was performed except that the polypropylene containing 420 ppm of the 3-methyl-1-pentene polymer was used. The results are shown in Table 2.

Examples 18, 19 Prepolymerization of 3-methyl-1-pentene was carried out in the same manner as in Example 17, except that the amount of 3-methyl-1-pentene introduced and the polymerization time were changed. The polypropylene containing 3-methyl-1-pentene polymer shown in 1 was obtained.
The crystallinity of the 3-methyl-1-pentene polymer obtained at this time was 58% as in Example 17. Furthermore, it carried out similarly to Example 17, and the result is shown in Table 2.

Comparative Examples 13 and 14 The procedure of Example 17 was repeated except that the polypropylene containing the 3-methyl-1-pentene polymer shown in Table 2 was used. The results are shown in Table 2.

Examples 20 and 21 Same as Example 17 except that the same polypropylene containing 3-methyl-1-pentene polymer as in Example 17 was used and the talc used in Example 17 was changed to the blending amount shown in Table 2. I went to. The results are shown in Table 2.

[0058]

[Table 2]

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Claims (2)

[Claims] 1. A crystalline polypropylene, a branched α-olefin polymer having 5 or more carbon atoms, 1 to 10000 ppm, and talc having an average particle size of 0.1 to 10 μm, 50 to 400.
A polypropylene resin composition comprising 0 ppm. 2. A polypropylene stretched film comprising the polypropylene composition according to claim 1 and stretched at least uniaxially.