JPH0446984B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a propylene polymer composition having excellent rigidity, heat shrinkage resistance, impact resistance, transparency, stretchability, heat resistance, etc., and a method for producing the same. Polypropylene takes advantage of its excellent rigidity, mechanical strength, transparency, and high heat deformation temperature.
It is widely used in various applications such as films, sheets, blow molded products, and injection molded products. In particular, taking advantage of the fact that various physical properties such as transparency and mechanical strength are significantly improved by applying stretching processing,
OPP film, stretched tape, flat yarn,
It is also widely used in stretch-molded products such as split fibers and bands. In order to obtain even more excellent rigidity in these various molded products, a method using a propylene homopolymer with an extremely high isotactic index has been proposed (for example, JP-A-57-103819). ) When trying to apply the method to stretched products, there was a problem in that the stretch-forming properties were poor and it was therefore impossible to obtain highly stretched molded products with excellent physical properties. As a method for producing polypropylene with improved stretchability, titanium tetrachloride is reduced with an organoaluminum compound, and a catalyst consisting of activated titanium trichloride and an organoaluminum compound is used.
A method of copolymerizing propylene and a small amount of ethylene has been proposed in JP-A-56-32512.
According to this proposal, it is true that stretchability can be improved by copolymerizing ethylene, but it is accompanied by a non-negligible decrease in stiffness, melting point, etc., and has the disadvantage that its field of use is limited. In view of the above circumstances, the present inventors conducted studies to produce a more balanced propylene polymer. As a result, we have discovered a propylene polymer that has a high melting point, excellent rigidity, heat shrinkage resistance, impact resistance, transparency, etc., and is also excellent in stretchability.
That is, the present invention provides a propylene polymer composition produced by a two-step polymerization method in which propylene is polymerized in one polymerization step and a random copolymer of propylene and ethylene is made in the other polymerization step, which comprises (a) Propylene homopolymer with I _sp value of 96.5% or more
more than 30 parts by weight and less than 70 parts by weight, and (b) the ethylene content ( _Ec mol%) is 0.3 to 3.0 mol%,
and the relational expression between I _sp value and E _c is more _than 30 parts by weight and less than 70 parts by weight [100 parts by weight of ( _a ) + (b)] ] and a method for producing the same. The propylene homopolymer (A), which is one component of the composition of the present invention, is a polymer consisting essentially only of propylene with a propylene content of 99.9 mol% or more, and whose I _sp value is 96.5% or more. Preferably it is 97.0% or more. Note that used in the present invention
The I _sp value is the triad tacticity determined by ¹³ C-NMR using the carbon signal of the methyl group, and in the case of copolymers with ethylene, the methyl group of propylene adjacent to ethylene is excluded. This is what I asked for. If the _Isp value of component (A) is smaller than the above range, it is not preferable because the composition will have poor rigidity, thermal properties, etc. 135 as propylene homopolymer (A)
°C, the intrinsic viscosity [η] measured in decalin is 1.2
from 1.5 to 6.0 dl/g, preferably from 1.5 to 5.0 dl/g
It is preferable to use The other component constituting the composition of the present invention has an ethylene content (E _c mol%) of 0.3 to 3.0 mol%;
Preferably it is 0.5 to 2.5 mol% of propylene/ethylene random copolymer (b). If the ethylene content is greater than the above range, the composition will lack rigidity and the heat resistance, heat shrinkage resistance, etc. will deteriorate, which is not preferable. The random copolymer (b) must also be highly stereoregular, with an I _sp value of I _sp ≧95.0−0.67E _c , preferably I _sp ≧95.5−0.67E _c The relational expression must be satisfied. If a propylene/ethylene random copolymer having an I _sp value smaller than the above range is used, the object of the present invention cannot be achieved because the composition will have poor rigidity, heat resistance, heat shrinkage resistance, etc. A large number of catalyst systems suitable for stereoregular polymerization of propylene have been proposed in the past, but most of them show a significant decrease in I _sp value when ethylene is randomly copolymerized, and therefore, as described above (b ) component cannot be manufactured. The above component (b) can be easily produced by using, for example, a catalyst system as described later. As a random copolymer, the intrinsic viscosity [η] measured in decalin at 135°C is 1.2 to 6.0.
dl/g, especially 1.5 to 5.0 dl/g is preferred. The blending ratio of propylene homopolymer (a) and propylene/ethylene random copolymer (b) is (a) more than 30 parts by weight and less than 70 parts by weight, preferably 35 to 65 parts by weight, and (b) More than 30 parts by weight and less than 70 parts by weight, preferably 35 to 65 parts by weight [(a) + (b) = 100 parts by weight]
It must be done so that If the blending ratio of component (a) is less than the above range, it is not preferable because the composition will lack rigidity and heat resistance.
If the blending ratio of the components exceeds the above range, stretchability, impact resistance, etc. will be poor and should be avoided. In addition, the propylene polymer composition consisting of (a) and (b) above has an ethylene content E _c of 0.2 to 2.0 mol%, and a relational expression between I _sp value and _{E c}
≧95.0−0.67E _c , and furthermore, the intrinsic viscosity [η] is
Preferably, the amount is 1.2 to 6.0 dl/g. For compositions consisting of components (a) and (b), components (a) and (b) are manufactured separately, and then mixed using ordinary mixing equipment such as various blenders, Henschel mixers, extruders, and kneaders. It can be manufactured by using and mixing. However, in order to obtain a composition that is easy to manufacture, has a good mixture of both components, and therefore exhibits particularly excellent physical properties,
It is preferable to employ a method in which both components are produced sequentially using the same catalyst. In particular, in the first step, propylene homopolymer (a) is produced in the presence of a catalyst,
Adopting a sequential polymerization method in which component (b) is then produced in the presence of component (a) has the advantage that the polymerization yield of component (b) is high and it is easy to obtain a copolymer with a high I _sp value. There is. Therefore, polymerization operability is good and the amount of by-product soluble polymer produced is small. That is, as a method for carrying out such two-stage polymerization, in the present invention, (A) a highly active titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components, (B) an organoaluminum compound catalyst component, and ( C) Polymerization is carried out in two or more stages using a catalyst formed from an organosilicon compound catalyst component having Si-O-C bonds or Si-N-C bonds, and (a)' in one polymerization stage; producing a propylene homopolymer having an I _sp value of 96.5% or more in a proportion of more than 30 parts by weight and less than 70 parts by weight by polymerizing propylene; The polymer has an ethylene content (E _c mol%) of 0.3 to 3.0 mol%, and
Producing a propylene-ethylene random copolymer whose relationship between I _sp value and E _c is I _sp ≧95.0−0.67E _c in a proportion of more than 30 parts by weight and less than 70 parts by weight (100 parts by weight in total) A method for producing a propylene polymer composition is provided. Highly active titanium catalyst component (A) used in the present invention
contains magnesium, titanium, halogen and an electron donor as essential components. Here, magnesium/titanium (atomic ratio) is preferably 2 to about 100, more preferably about 4 to about 70, and halogen/titanium (atomic ratio) is preferably about 4 to about 100, even more preferably about 6 to about 70. 400, and the electron donor/titanium (molar ratio) preferably ranges from about 0.2 to about 10, more preferably from 0.4 to about 6. Further, the specific surface area is preferably 3 m ² /g or more, more preferably about 40 m ² /g or more, and even more preferably 100 m ² /g to 800 m ² /g.
It is. Such a solid titanium catalyst component (A) is
Simple measures such as hexane washing at room temperature do not usually remove titanium compounds. The X-ray spectrum of the magnesium compound, regardless of the raw material magnesium compound used for catalyst preparation, is either amorphous or, desirably, very amorphous compared to that of a common commercially available magnesium dihalide. It is in a crystallized state. The titanium catalyst component (A) may contain other elements, metals, functional groups, etc. in addition to the above-mentioned essential components as long as the catalyst performance is not significantly deteriorated. Furthermore, it may be diluted with an organic or inorganic diluent. If it contains other elements, metals, diluents, etc., it may affect the specific surface area and amorphousness, and in that case, when such other components are removed, the specific surface area as mentioned above will change. It is desirable that the material exhibits a value of 1 and exhibits amorphous property. Electron donors preferably contained in the titanium catalyst component (A) include ethylene carboxylates, carbonate esters, orthoesters, alkoxysilane compounds,
These include allyloxysilane compounds, among which esters of dicarboxylic acids are most preferred. The ester of dicarboxylic acid is also an ester of dicarboxylic acid in which two carboxyl groups are bonded to one carbon atom or an ester of dicarboxylic acid in which carboxyl groups are bonded to two adjacent carbon atoms. It is desirable that there be. Specifically, malonic acid, substituted malonic acid, succinic acid, substituted succinic acid,
Maleic acid, substituted maleic acid, fumaric acid, substituted fumaric acid, alicyclic dicarboxylic acid in which two carboxyl groups are bonded to one carbon atom forming an alicyclic ring, two adjacent carbon atoms forming an alicyclic ring Dicarboxylic acids such as alicyclic dicarboxylic acids with carboxyl groups bonded to each atom, aromatic dicarboxylic acids with carboxyl groups in the ortho position, and heterocyclic dicarboxylic acids with carboxyl groups on two adjacent carbon atoms forming a heterocycle. Mention may be made of esters of acids.
More specifically, malonic acid; substituted malonic acids such as methylmalonic acid, ethylmalonic acid, isopropylmalonic acid, allylmalonic acid, phenylmalonic acid; succinic acid; methylsuccinic acid, dimethylsuccinic acid, ethylsuccinic acid, methyl Substituted succinic acids such as ethylsuccinic acid and itaconic acid; Substituted maleic acids such as maleic acid, citraconic acid, and dimethylmaleic acid; Cyclopentane-1,1-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, and cyclohexane-1 , 2-dicarboxylic acid, cyclohexene-1,6-dicarboxylic acid, cyclohexene-3,4-dicarboxylic acid, cyclohexene-4,5-dicarboxylic acid, nadic acid, methylnadic acid, 1-allylcyclohexane-3,4-
Alicyclic dicarboxylic acids such as dicarboxylic acid; aromatic dicarboxylic acids such as phthalic acid, naphthalene-1,2-dicarboxylic acid, naphthalene-2,3-dicarboxylic acid; furan-3,4-dicarboxylic acid, 4,5
-dihydrofuran-2,3-dicarboxylic acid, benzopyran-3,4-dicarboxylic acid, pyrrole-
2,3-dicarboxylic acid, pyridine-2,3-dicarboxylic acid, thiophene-3,4-dicarboxylic acid,
Examples include esters of dicarboxylic acids such as heterocyclic dicarboxylic acids such as indole-2,3-dicarboxylic acid. At least one of the alcohol components of the above ester preferably has 2 or more carbon atoms, especially 3 or more carbon atoms, and both alcohol components preferably have 2 or more carbon atoms, especially 3 or more carbon atoms. For example, diethyl ester, diisopropylene ester, di-n-propyl ester, di-n-butyl ester, diisobutyl ester, di-tert-butyl ester, diisoamyl ester, di-n-hexyl ester, di-2-
Examples include ethylhexyl ester, di-n-octyl ester, diisodecyl ester, and ethyl n-butyl ester. Many proposals have already been made regarding methods for producing highly active titanium catalyst components containing electron donors, and titanium catalyst components containing diester as an essential component can be produced in large quantities by methods based on these proposed techniques. For example, JP-A No. 50-108385, JP-A No. 50-126590
No. 51-20297, No. 51-28189, No. 51-
No. 64586, No. 51-92885, No. 51-136625, No. 52
-87489, 52-100596, 52-147688,
No. 52-104593, No. 53-2580, No. 53-40093,
No. 53-43094, No. 55-135102, No. 55-135103
No. 56-811, No. 56-11908, No. 56-18606
It can be manufactured according to the method disclosed in Japanese Patent Application No. 56-181019. Among the titanium catalyst components produced by the method described above, it is preferable to use a titanium catalyst component that has been subjected to a step in which a magnesium compound is once made into a liquid state and then precipitated as uniform particles in the process of preparing the catalyst component.
and the average particle size is in the range of about 1 to about 100μ, and the geometric standard deviation of the particle size distribution σg is 2.1 or less,
Preferably, it is 0.95 or less and has a regular shape such as a true sphere, a spherical shape, or a granular shape. As the organoaluminum compound catalyst component (B),
Specifically, triethylaluminum, tributylaluminum, etc. are trialkylaluminum,
In addition to trialkenylaluminums such as triisoprenylaluminum, dialkylaluminum alkoxides such as diethylaluminum ethoxide, dibutylaluminum butoxide, alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide, butylaluminum sesquibutoxide, R ¹ _2.5 Al ( OR ² ) Partially alkoxylated alkylaluminiums, dialkylaluminum halides such as diethylaluminum chloride, dibutylaluminum chloride, diethylaluminium bromide, ethylaluminum sesquichloride, butylaluminum sesquichloride, with an average composition expressed as _0.5 , etc. , alkyl aluminum sesquihalides, such as ethyl aluminum sesquibromide,
Partially halogenated alkylaluminiums such as alkylaluminum dihalides such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dibromide etc., dialkylaluminum hydrides such as diethylaluminum hydride, dibutylaluminum hydride, ethylaluminum dihydride, Partially hydrogenated alkyl aluminums such as alkyl aluminum dihydrides such as propyl aluminum dihydride, partially alkoxylated and halogenated alkyl aluminums such as ethyl aluminum ethoxy chloride, butyl aluminum butoxy chloride, ethyl aluminum ethoxy bromide It is. Compounds belonging to (ii) above include LiAl(C ₂ H ₅ ) ₄ ,
Examples include LiAl(C ₇ H ₁₅ ) ₄ . Further, as a compound similar to (i), it may be an organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom. Examples of such compounds include (C ₂ H ₅ ) ₂ AlOAl
(C ₂ H ₅ ) ₂ , (C ₄ H ₉ ) ₂ AlOAl(C ₄ H ₉ ) ₂ ,

Examples include [Formula]. Among these, it is particularly preferable to use trialkylaluminum and the above-mentioned alkyl aluminum in which two or more aluminums are combined. Si-O-C or Si- used in the present invention
Organosilicon compound catalyst component (C) having an N-C bond
Examples include alkoxysilane and aryloxysilane. As such an example, the formula RnSi(OR ¹ ) _4-o (where 0≦n≦3,
R is a hydrocarbon group, such as an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a haloalkyl group, an aminoalkyl group, or a halogen;
R ¹ is a hydrocarbon group, such as an alkyl group, cycloalkyl group, aryl group, alkenyl group, alkoxyalkyl group, etc. However, n R and (4-n) OR ¹ groups may be the same or different. Examples include silicon compounds represented by the following. Further, other examples include siloxanes having ^one OR group, silyl esters of carbones, and the like. In addition, as another example, two or more silicon atoms,
Mention may be made of compounds which are bonded to each other via oxygen or nitrogen atoms. More specifically, trimethylmethoxysilane,
Trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxy Silane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyl Triisopropoxysilane, vinyltributoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxysilane, vinyltris(β-methoxyethoxy)silane, vinyltriacetoxysilane, diethyltetraethoxy Examples include disiloxane and phenyldiethoxydiethylaminosilane. Among these, particularly preferred are methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltributoxysilane, ethyl silicate, These are those represented by the formula RnSi(OR ¹ ) _4-o such as diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenylmethoxysilane. The composition of the present invention can be obtained by sequentially producing component (a) and component (b) using a catalyst formed from (A), (B), and (C). As mentioned above, it is advantageous to first produce component (a) and then produce component (b) in its presence. Polymerization is preferably carried out by slurry polymerization or gas phase polymerization. In slurry polymerization, when the powder polymer is separated from the polymerization medium by means such as filtration or centrifugation after polymerization, the properties of the solid polymer at each polymerization stage are different from those of component (a) and component (b). However, if the polymerization medium is flashed off after polymerization, the solvent-soluble polymer will also be mixed during production, so the solid polymer and solvent-soluble polymer will be mixed at each polymerization stage. The combination of polymers is
It must exhibit properties that meet the requirements of component (a) and component (b). In slurry polymerization, propylene itself may be used as the polymerization medium, or an inert hydrocarbon such as butane, hexane, heptane may be used. In polymerization, the titanium catalyst component (A) is converted into titanium atoms from 0.0001 to 1 per polymerization volume.
1.0 mmol, especially 0.001 to 0.1 mmol, the organoaluminum compound catalyst component (B) in Al/Ti (atomic ratio) of 1 to 2000, especially 5 to 500, and the organosilicon compound catalyst component in Si/Al (atomic ratio) of 0.001.
It is preferable to use it in a ratio of from 0 to 0, especially from 0.01 to 2. Each of these catalyst components can be used in preliminary contact with each other, and in that case, each catalyst component may or may not be further added during polymerization. Polymerization temperature is 20 to 150℃, especially 50 to 10℃
The polymerization pressure is preferably in the range of atmospheric pressure to 100 kg/cm ² , particularly 2 kg/cm ² to 5 kg/cm ² . Any amount of hydrogen may be used to obtain the desired molecular weight. When producing component (b), the propylene/ethylene (partial pressure ratio) in the system may be about 30 to 500, particularly about 50 to 300, although it varies depending on the polymerization conditions. The composition of the present invention may optionally contain various additives such as heat stabilizers, weather stabilizers, lubricants, slip agents, nucleating agents, antistatic agents, antifogging agents, pigments, dyes, and inorganic or organic fillers. Can be blended. The composition of the present invention has excellent rigidity, heat shrinkage resistance, impact resistance, transparency, stretchability, etc., and can be used for various molded products. In particular, it is suitable for use in stretched tapes, bands, uniaxially stretched films, biaxially stretched films, stretched hollow bottles, etc. that utilize stretching properties. Furthermore, by adding polyethylene or a low-crystalline or amorphous ethylene/α-olefin copolymer, a composition with excellent impact resistance and rigidity can be molded into industrial parts, automobile parts, and home appliance parts. It can be used as Next, an example will be explained. Examples 1 to 8, Comparative Examples 7 to 9 (1) Preparation of solid Ti catalyst component 4.8 kg of anhydrous magnesium chloride, 25.0 kg of decane, and 23.4 kg of 2-ethylhexyl alcohol to 130 kg
After heating the reaction at ℃ for 2 hours to make a homogeneous solution,
Add 11.1Kg of phthalic anhydride to this solution,
Stirring and mixing is continued for an additional hour at 0.degree. C. to dissolve the phthalic anhydride into a homogeneous solution. After the homogeneous solution thus obtained was cooled to room temperature, the entire amount was dropped into titanium tetrachloride 200 maintained at -20°C. After charging, the temperature of this mixed liquid was raised to 110℃, and
When the temperature reaches ℃, diisobutyl phthalate
2.7 was added and the mixture was kept at the same temperature for 2 hours with stirring. After 2 hours of reaction, the solid part was collected by heating and suspended again in titanium tetrachloride 200.
After reacting at 120°C for 2 hours, the solid portion is collected by heating and thoroughly washed with hexane at 110°C until the concentration of free titanium compounds in the washing liquid is 0.1 mmol or less. By the above manufacturing method, solid Ti
A catalyst component was obtained. (2) Prepolymerization treatment of catalyst Triethylaluminum in hexane 18
2700mmol, diphenyldimethoxysilane
540 mmol, the above solid Ti catalyst component in terms of titanium
After adding 270 mmol at 25 °C, 920 Nl of propylene
was fed for 1.5 hours to polymerize a small amount of propylene. When analyzed, the amount of prepolymerization was 7.2g/
It was mM-Ti. (3) Polypropylene manufacturing method Two continuous polymerizers A and B connected in series (capacity 250
) was used. The solid Ti component pretreated above is added to polymerization vessel A as a hexane slurry in terms of Ti atoms.
0.56 mmol/HR, triethylaluminum as a hexane solution, 28 mmol/HR, dimexysilane as a hexane solution, 2.5 mmol/HR, and hexane were continuously introduced at a total rate of 27.3/HR, and propylene was introduced at a pressure of 13 kg in the polymerization vessel. Polymerization was carried out at 70° C. by continuously feeding the solution at a temperature of 1.2 G/cm ² G. Also, by continuously adding hydrogen,
Adjusted MFR. Polymerization was carried out at 70°C by continuously feeding a mixed gas of ethylene and propylene into the polymerization vessel B such that the pressure inside the polymerization vessel was 10 kg/cm ² G. The MFR was also adjusted by continuously adding hydrogen. The slurry discharged from polymerization vessel B was treated with a decanter to separate the polymer and hexane solvent, and the polymer was dried. The results are shown in Table 1. Next, appropriate antioxidants, hydrochloric acid absorbers, and antistatic agents were added to the copolymers obtained in Examples 1 to 6 and Comparative Examples 7 to 9, and the mixtures were pelletized using an extruder.
Then, after melting in an extruder, the resin temperature is 270℃.
extruded through a T-die, cooled and solidified into a sheet,
Then heated rolls at 130℃ and 140℃ (speed 4m/
min, 20 m/min), the film was stretched in the longitudinal direction at a stretching ratio of 5 times. Next, this sheet was stretched in the transverse direction at a stretching ratio of 10 times in a tenter at 190° C. near the inlet and 165° C. near the exit, to obtain a film with a thickness of about 30 μm. However, in Comparative Example 7 and Comparative Example 9, good films were not obtained at the tenter setting temperature of 190°C to 165°C.
For Comparative Example 9, the temperature was raised to 170°C and molding was performed. Next, the film was evaluated by the following method.
Haze (%): ASTM D1003 Impact strength (Kgcm/cm): Conducted using Toyo Seiki's film impact teter. The diameter of the impact head sphere was 1 inch. Young's modulus (Kg/cm ² ): This is the value when stretched at a tensile speed of 200 mm/min using a JIS K6781 dumbbell. Heat shrinkage rate (%): The shrinkage rate was determined after being held in an atmosphere at 140°C for 15 minutes. Melting point (°C): Using PerkinElmer DSC,
After holding at 200°C for 5 minutes, the temperature was lowered to 50°C at 20°C/min, and the peak position of the endothermic curve that appeared when the temperature was raised at 5°C/min was determined. The results are shown in Table 2. Further, an appropriate antioxidant was added to the copolymers obtained in Examples 7 and 8, and the mixture was pelletized using an extruder. Then, using a 90 mmφ extrusion stretch blow molding machine, the extruder was held at a resin temperature of 200°C and a pipe reheating temperature of 162.5°C for 25 minutes to form a bottle with a volume of 350 c.c. Next, the bolt was evaluated by the following method. Haze (%): ASTM D1003 Tensile properties: Measured at a tensile speed of 50 mm/min using a JIS K7113 type 2 test piece. Drop strength (cm): The height at which 50% destruction occurs was determined at 0°C. Melting point (°C): Using PerkinElmer DSC,
After holding at 200°C for 5 minutes, the temperature was lowered to 50°C at 20°C/min, and the peak position of the endothermic curve that appeared when the temperature was raised at 5°C/min was determined. The results are shown in Table 3. Comparative Example 1, 10 One continuous polymerization vessel with a capacity of 250 was used. The solid Ti catalyst component was prepared and the catalyst was pretreated in the same manner as Examples 1 to 8 and Comparative Examples 7 to 9. Add the solid Ti component pretreated above as a hexane slurry to the polymerization vessel in terms of Ti atoms.
0.56 mmol/HR, triethylaluminum as a hexane solution at 28 mmol/HR, dimethoxysilane as a hexane solution at a rate of 2.8 mmol/HR, and hexane in a total of 27.3/HR. 13Kg/ ^cm2G
Polymerization was carried out at 70°C. In addition, by continuously adding hydrogen, MFR
adjusted. The slurry discharged from the polymerization vessel was treated with a decanter to separate the polymer and hexane solvent, and the polymer was dried. The results are shown in Table 1. Next, Comparative Example 1 was molded under the same molding conditions as Examples 1 to 6, and Comparative Example 10 was molded under the same molding conditions as Examples 7 and 8, except that the pipe reheating temperature was 162.5°C.
However, since the bolts were not good, the temperature was lowered.
Molding was carried out at a temperature of 167.5°C. The results are shown in Tables 2 and 3, respectively. Comparative Examples 2 and 11 One continuous polymerization vessel with a capacity of 250 was used. Titanium trichloride (manufactured by Toho Titanium Co., Ltd.) was used in the polymerization vessel.
TAC-101) is 218.4 mmol/HR in terms of Ti atoms,
Diethylaluminium monochloride was continuously introduced as a hexane solution at a rate of 655.2 mmol/HR and hexane was continuously introduced at a total ratio of 27.3/HR, and propylene was continuously fed so that the pressure inside the polymerization vessel was 13 Kg/cm ² G. and polymerization was carried out at 70°C. The MFR was also adjusted by continuously adding hydrogen. The slurry discharged from the polymerization vessel was treated with a decanter to separate the polymer and hexane solvent, and the polymer was dried. The results are shown in Table 1. Next, Comparative Example 2 was molded under the same molding conditions as Examples 1 to 6, and Comparative Example 1 was molded under the same molding conditions as Examples 7 and 8.
Molding was carried out under the same molding conditions. The results are shown in Tables 2 and 3, respectively. Comparative Examples 3, 4, 12 Two continuous polymerizers A and B connected in series (capacity 250
) was used. Titanium trichloride (manufactured by Toho Titanium Co., Ltd.) was placed in polymerization vessel A.
TAC-101) in terms of Ti is 218.4 mmol/HR, diethylaluminum monochloride is in hexane solution and is 655.2 mmol/HR, and hexane in total.
Propylene was continuously introduced at a ratio of 27.3/HR, and propylene was continuously fed so that the pressure inside the polymerization vessel was 13 Kg/cm ² G, and polymerization was carried out at 70°C. The MFR was also adjusted by continuously adding hydrogen. Polymerization was carried out at 70°C by continuously feeding a mixed gas of ethylene and propylene into the polymerization vessel B such that the pressure inside the polymerization vessel was 10 kg/cm ² G. The MFR was also adjusted by continuously adding hydrogen. The slurry discharged from polymerization vessel B is treated with a decanter to separate it into polymer and hexane solvent,
The polymer was dried. The results are shown in Table 1. Next, Comparative Example 3 was molded under the same molding conditions as Examples 1 to 6, Comparative Example 4 was molded under the same molding conditions as Comparative Example 7, and Comparative Example 2 was molded under the same molding conditions as Examples 7 and 8.
Molding was carried out under the same molding conditions. The results are shown in Tables 2 and 3, respectively. Comparative Example 5 One continuous polymerization vessel with a capacity of 250 was used. Titanium trichloride, diethylaluminium monochloride, and hexane were continuously introduced into the polymerization vessel in the same manner as in Comparative Example 2.11, and a mixed gas of ethylene and propylene was continuously introduced so that the pressure inside the polymerization vessel was 13 Kg/cm ² G. and polymerization was carried out at 70°C. The MFR was also adjusted by continuously adding hydrogen. The slurry discharged from the polymerization vessel was treated with a decanter to separate the polymer and hexane solvent, and the polymer was dried. The results are shown in Table 1. Next, molding was performed under the same molding conditions as in Comparative Example 7. The results are shown in Table 2. Ratio Comparative Examples 6 and 13 The solid Ti component was prepared and the catalyst was pretreated in the same manner as in Examples 1 to 8 and Comparative Examples 7 to 9, in which one continuous polymerization vessel with a capacity of 250 was used. As in Comparative Examples 1 and 10, the solid Ti component, triethylaluminum, dimethoxysilane, and hexane were continuously introduced into the polymerization vessel, and the mixed gas of ethylene and propylene was heated to a pressure of 13 Kg/cm ² G in the polymerization vessel.
Polymerization was carried out at 70°C. The MFR was also adjusted by continuously adding hydrogen. The slurry discharged from the polymerization vessel was treated with a decanter to separate the polymer and hexane solvent, and the polymer was dried. The results are shown in Table 1. Next, Comparative Example 6 was molded under the same molding conditions as Examples 1 to 6, and Comparative Example 13 was molded under the same molding conditions as Examples 7 and 8.
Molding conditions equivalent to, but pipe reheating temperature
Because it was not a good bolt at 162.5℃,
Molding was carried out by lowering the temperature to 159°C. The results are shown in Tables 2 and 3, respectively.

【table】

【table】

【table】

【table】

[Table] Comparative Example 14 A homopolymer was prepared in the same manner as in Comparative Example 1, except that the gas composition and H ₂ pressure were changed in order to match the MFR and Ec of the polymer with the polymer in polymerization vessel B of Example 1. A propylene/ethylene random copolymer was obtained in the same manner as in Comparative Example 6. Table 4 shows the polymerization conditions and polymerization results. After mixing each polymer at a polymerization ratio of 1:1,
Pelletizing and molding were carried out in the same manner as in Example 1, and 2
An axially stretched film was obtained. Table 5 shows the physical properties of the film.

【table】

【table】 [Brief explanation of the drawing]

The drawings show Examples and Comparative Examples (Comparative Examples 1, 2,
5, 6, 10, 11, and 13)) is a graph in which the Iso value is blotted against the ethylene content (Ec mol %) of propylene/ethylene random copolymers produced in polymerization reactor B. The straight line is Iso=95.0−
Shows 0.94Ec.

Claims (1)

[Claims] 1 Polymerization of propylene in one polymerization step,
In a propylene polymer composition formed by a two-step polymerization method consisting of random copolymerization of propylene and ethylene in the other polymerization step, (a) a propylene homopolymer having an Iso value of 96.5% or more;
more than 30 parts by weight and less than 70 parts by weight, and (b) ethylene content (Ec mol%) from 0.3 to 3.0
A propylene/ethylene random copolymer which is mol% and whose relationship between Iso value and Ec is Iso≧95.0−0.67Ec
A propylene polymer composition consisting of more than 30 parts by weight and less than 70 parts by weight [(a) + (b) = 100 parts by weight]. 2 (A) a highly active titanium catalyst component that essentially includes magnesium, titanium, halogen, and an electron donor; (B) an organoaluminum compound catalyst component; and (C) an organosilicon compound catalyst component having a Si-O-C bond. (a) in one polymerization stage, polymerization of propylene is carried out to produce more than 30 parts by weight of propylene homopolymer having an Iso value of 96.5%, and 70 parts by weight; (b) in the other step, the random copolymerization of propylene and ethylene is carried out so that the ethylene content (Ec mol%) is from 0.3 to 3.0 mol%, and
A propylene/ethylene random copolymer having a relationship between Iso value and Ec of Iso≧95.0−0.67Ec is produced in a proportion of more than 30 parts by weight and less than 70 parts by weight (100 parts by weight in total). A method for producing a propylene polymer composition.