JPH0565321A - Propylene/ethylene block copolymer - Google Patents

Abstract

PURPOSE:To provide a propylene/ethylene block copolymer excellent in the balance among rigidity, impact resistance, especially falling weight impact strength, and surface gloss. CONSTITUTION:The objective propylene/ethylene block copolymer is obtained by polymerizing an olefin in multiple stages in the presence of a stereoregular polymerization catalyst essentially consisting of a solid catalyst component comprising magnesium, halogen and titanium, wherein the ethylene content (Eb) in the copolymer is 3-20wt.%, the weight fraction (f1) of the 1,2,4- trichlorobenzene solubles at 30 deg.C is higher than the ethylene content in the copolymer, and the ratio (f2/f1) (wherein f2 is the weight fraction of the 1,2,4- trichlorobenzene solubles at 120 deg.C) is 0.7-4.0.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a propylene ethylene block copolymer. For more details,
The present invention relates to a copolymer having excellent balance of rigidity, impact resistance, particularly falling weight impact strength, and surface gloss.

[0002]

2. Description of the Related Art Conventionally, so-called propylene ethylene block obtained by multi-stage polymerization of olefins in the presence of a stereoregular catalyst containing at least a solid catalyst component containing magnesium, halogen and titanium as its constituent components. Copolymers are widely used in containers, automobile parts, home electric appliances, etc., but in these applications, improvement in the balance of rigidity, impact resistance, particularly falling weight impact strength, and surface gloss is desired.

In order to solve such a problem, Japanese Patent Publication No. 57-26613 has been proposed. In the case of this copolymer, the balance between rigidity and surface gloss is good, but impact resistance, especially falling weight Impact strength is not sufficient. To solve this drop weight impact strength, Japanese Patent Publication No. 63-1968 has been proposed, but it is difficult to obtain a copolymer having good surface gloss with this copolymer.

[0004]

In view of such circumstances, the present invention provides a copolymer capable of obtaining a molded article having excellent balance of rigidity, impact resistance, particularly falling weight impact strength and surface gloss. Is provided.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have found that the soluble content of 1,2,4-trichlorobenzene at 30 ° C. and the insoluble content of 1,2,4-trichlorobenzene at 120 ° C. are specific amounts. It has been found that the propylene ethylene block copolymer having the ratios of and is excellent in the balance of rigidity, impact resistance, particularly falling weight impact strength and surface gloss.

That is, the present invention relates to magnesium, halogen
A solid catalyst component containing titanium and titanium.
In the presence of a stereoregular catalyst contained as a component, in multiple stages
Propylene ethylene broth obtained by polymerization
(A) ethylene in the copolymer
Content (E_b) Is 3 to 20% by weight, (B) 30 ° C.
Of 1,2,4-trichlorobenzene soluble matter in
Ratio (f ₁) Is larger than the ethylene content of (A), and
(C) 1,2,4-trichloro at 120 ° C
Weight ratio of benzene insoluble matter (f₂) And f above₁Ratio with
(F₂/ F₁) Is 0.7 to 4.0.
It is a propylene-ethylene block copolymer to be characterized.

In the present invention, if any of the above requirements is not satisfied, a copolymer having the improved physical properties which is the object of the present invention cannot be obtained. The propylene ethylene block copolymer is a propylene homopolymer or a copolymer of propylene and other α-olefins produced in the first stage in the presence of various types of stereoregular catalysts, and the second stage and thereafter. A copolymer obtained by copolymerizing propylene and ethylene in the presence of the polymer. Generally, the copolymer is a polymer or an intimate mixture of copolymers produced in each step, and is known as a copolymer having improved impact resistance.

The present invention will be specifically described below.
In the present invention, the ethylene content (E _b ) in the copolymer must be 3 to 20% by weight in order to make the copolymer exhibit a balance of rigidity, impact resistance, drop weight impact strength and surface gloss. is there. It is preferably 5 to 15% by weight. Those having an ethylene content of less than 3% by weight are inferior in impact resistance, particularly falling weight impact strength. Further, those having an ethylene content of more than 20% by weight are inferior in rigidity and surface gloss, which is not preferable.

In the copolymer of the present invention, 1,2,4-
Sorted with trichlorobenzene (abbreviated as TCB below)
Of TCB soluble content at 30 ° C
(F ₁) And the weight ratio of TCB insoluble matter at 120 ° C
(F₂) And f above₁Ratio with (f₂/ F₁) Is a specific range
Need to be in. Here, TC used in the present invention
The classification according to B. Wild et al. Is a Polymer P
reprints Am. Chem. Soc. ，18，
182 (1977) of linear low density polyethylene
It carried out based on the temperature rising elution fractionation method used for fractionation.

That is, a predetermined amount of a copolymer and an antioxidant are dissolved by heating in TCB, and this solution is filled with sea sand.
After filling in a stainless steel column kept at a temperature of ˜160 ° C., the temperature of the column is lowered to room temperature to sufficiently crystallize the copolymer. After the temperature of this column was raised to 30 ° C. again, TCB warmed to 30 ° C. was flowed in from the pipe connected to the column to take out the soluble matter at this temperature.
Methanol is added to the extracted TCB solution containing soluble components to reprecipitate the soluble components, followed by filtration and drying to obtain TCB soluble components at 30 ° C. The insoluble matter at 120 ° C can be obtained in the same manner as in the case of 30 ° C by eluting the soluble matter at 120 ° C and then raising the column temperature to 160 ° C.

Although the composition of the soluble matter at 30 ° C. and the insoluble matter at 120 ° C. is not clear, the soluble matter at 30 ° C. is substantially amorphous and the insoluble matter at 120 ° C. Is considered to correspond to a particularly highly crystalline part of the propylene homopolymer or the part of propylene and other α-olefin copolymer. In the copolymer of the present invention, the weight ratio (f ₁ ) of the TCB-soluble component at 30 ° C. must be larger than the ethylene content (E _b ) in the copolymer. If f ₁ is smaller than E _b , a copolymer having good surface gloss cannot be obtained.

In the copolymer of the present invention, the weight ratio (f ₂ ) of TCB insoluble matter at 120 ° C. and T at 30 ° C.
If the ratio (f ₂ / f ₁ ) to the weight ratio (f ₁ ) of the CB soluble component is 0.7 to 4.0, preferably 1.5 to 3.0, the desired physical property balance is achieved. No copolymer is obtained. In the present invention, f ₂ / f ₁ of less than 0.7 is inferior in rigidity, and f ₂ / f ₁ of more than 4.0 is inferior in impact resistance, particularly falling weight impact strength, which is not preferable.

The propylene ethylene block copolymer of the present invention comprises, for example, a solid catalyst component containing at least magnesium, halogen, aromatic carboxylic acid ester and titanium as its component, a catalyst formed from an organoaluminum compound and an alkoxysilane compound. Using propylene to produce a homopolymer of propylene or a copolymer of propylene and another α-olefin in the first stage, and subsequently to copolymerize propylene and ethylene in the presence of the polymer in the second stage and thereafter. Can be manufactured by

As the solid catalyst component, the activated magnesium halide, the titanium compound and the aromatic carboxylic acid ester are simultaneously or stepwise co-pulverized, or the magnesium compound in a homogeneous state is mixed with the aromatic carboxylic acid ester. Alternatively, a halogenating agent or a reducing agent is allowed to act in the presence or absence of another electron donor, and the obtained precipitate is contacted with a titanium compound in the presence of an aromatic carboxylic acid ester, if necessary. What is obtained by the method of can be utilized. As a preferred method for producing a solid catalyst component, an organic magnesium component or a hydrocarbyloxymagnesium compound soluble in a hydrocarbon solvent,
A method in which a titanium compound and an aromatic carboxylic acid ester are brought into contact with a precipitate obtained by reacting a halogenating agent, particularly preferably a chlorosilane compound having an H—Si bond. More specifically, for example, Japanese Patent Publication No. Sho 60-11924 and Japanese Patent Laid-Open No. 1-213311.
JP-A-1-259003, JP-A-2-28201
JP-A-1-138312 and JP-A-2-1383
Those manufactured according to the method described in each publication of No. 13 can be used.

Examples of the organic aluminum compound include trimethyl aluminum, triethyl aluminum,
Triisobutyl aluminum, trialkyl aluminum such as trihexyl aluminum, diethyl aluminum chloride, diisobutyl aluminum chloride, alkyl aluminum halide such as ethyl aluminum sesquichloride, further, diethyl aluminum ethoxide, diethyl aluminum butoxide,
Alkyl aluminum alkoxides such as diethyl aluminum phenoxide are available and mixtures of these are also available.

Examples of the alkoxysilane compound include tetraalkoxysilane such as methyl silicate and ethyl silicate, phenyltrimethoxysilane, phenylethoxysilane, isobutyltriethoxysilane, cyclohexyltriethoxysilane, and dodecyltriethoxysilane. Dialkoxysilanes such as silane, diphenyldimethoxysilane, diphenyldiethoxysilane, cyclohexylmethyldimethoxysilane, cyclopentylmethyldimethoxysilane, diisobutyldimethoxysilane, isobutylisopropyldimethoxysilane,
Monoalkoxysilanes such as phenyldimethylmethoxysilane and diphenylmethylmethoxysilane can be used, but among them, trialkoxysilane and dialkoxysilane are preferable. Moreover, you may use these together.

The amount of each catalyst component to be used is in the range of 1 to 3000 mmol, preferably 10 to 1000 mmol, in terms of aluminum atoms in 1 gram of the solid catalyst component. 0.01 to 1000 mmol, converted to silicon atoms in
Preferably 1 to 500 mmol is used. Further, the ratio of and is preferably used in the range of 100: 5 to 100: 50.

These respective catalyst components may be brought into contact with each other during polymerization, or they may be brought into contact with each other in advance. The contact may be in an inert gas atmosphere or an olefin atmosphere. The propylene ethylene block copolymer of the present invention is a known polymerization method, that is, a slurry method, a monomer bulk method,
It can be produced by any method of the gas phase method, but among them, the method of using a gas phase polymerization apparatus having a stirring fluidized bed is preferable.

Various types of gas phase polymerization apparatus having a stirring fluidized bed can be used, but preferably a helical type stirring blade having a Froude number at the center of 1 is used.
Having a stirring layer composed of a finely divided polymer which is operated under conditions of 3 to 3, and continuously or intermittently feeding a mixture composed of propylene or another α-olefin containing propylene and ethylene to a polymerization zone, It is possible to use those having a basic constitution that polymerization is initiated by supplying each component of the catalyst to the polymerization zone, and the obtained polymer is continuously or intermittently taken out from the polymerization zone.

As the polymerization method, for example, at a temperature of 40 to 95 ° C. and a pressure of 10 to 35 kg / cm ² (gauge pressure), propylene or a mixture of propylene and another α-olefin is continuously or intermittently. Is supplied to the polymerization zone to remove the heat of polymerization generated by the polymerization and to supplement the propylene consumed by the polymerization, or a mixture of propylene and other α-olefins, and unreacted propylene or propylene. Polymerization is carried out by a method comprising taking out a mixture of other α-olefins from the polymerization zone, liquefying it, feeding it again to the polymerization zone in a liquid state, and continuously or intermittently taking out the obtained polymer from the polymerization zone. The method of continuing is used.

A propylene ethylene block copolymer can be produced by connecting two or more of the above polymerization devices. In order to obtain the propylene-ethylene block copolymer of the present invention, the ethylene content of the propylene-ethylene copolymer produced in each stage of the second stage polymerization zone is 35 to 70 wt% and the final ethylene content is 3%. It is important to control the production amount so as to be 20 to 20 wt%.

For example, in the first stage polymerization zone, the polymerization temperature is 50 to 95 ° C., the polymerization pressure is 17 to 35 kg / cm ² ,
The polymerization residence time is 1.5 to 4 hours, and the propylene homopolymer or other α-olefin (for example, ethylene, 1
A propylene copolymer having a content of butene, 1-pentene, 1-hexene, 1-octene, 1-decene) of less than 5% by weight is produced.

The resulting polymer is subsequently transferred to the second stage polymerization zone and the polymerization is continued. At this time, for example, a copolymer of propylene and ethylene is produced at a pressure lower than that of the former stage by at least 7 kg / cm ² and a polymerization temperature of 40 to 70 ° C. The ratio of propylene and ethylene fed to the second-stage polymerization zone is selected according to the purpose when the partial pressure ratio of propylene and ethylene in the second-stage polymer is, for example, in the range of 91: 9 to 40:60. To be done. The second
In the stage, the polymerization pressure and the residence time are adjusted so that the ethylene content in the final product, propylene ethylene block copolymer, is 3 to 20% by weight. The production ratio of the polymer in the first stage and the second stage is, for example, in the range of 90:10 or 30:70 by weight, particularly 86: 1.
A range of 4 to 40:60 is preferably used. Also,
In the propylene ethylene block copolymer of the present invention, the production of the propylene polymer or copolymer in the first stage and the second stage can be carried out in two or more stages, respectively, if necessary. At that time, the polymerization conditions of each stage can be arbitrarily set within the above range. A method of this kind is described in US Pat.
No. 12573, 4330645, 444271,
Reference may be made to the methods and examples of British Patent No. 1032945.

[0024]

EXAMPLES The present invention will be described below with reference to examples. Each measured value used in the examples is measured according to the method described below. To the obtained copolymer powder, 0.05% by weight of P-EPQ (manufactured by Sand Co.) and 0.1% by weight of calcium stearate were added as additives, pelletized by an extruder, MFI and ethylene. The content was measured by the following method.

A test piece was prepared from the obtained pellet by injection molding, and the flexural modulus, falling weight impact strength, and gloss were measured by the following methods. The injection molding temperature during injection molding was performed under the following conditions unless otherwise specified. That is, the MFI of the propylene ethylene block copolymer is 3
If less than 280 ℃, 3 if less than 7 260
℃, if it is 7 or more and less than 15, it is 240 ℃, and if it is 15 or more, it is 220 ℃. 1. Compliant with MFI ASTM D1238 (230 ° C, 2.16k
g, condition L) 2. Ethylene content The ethylene content was quantified with an A-302 infrared spectrophotometer manufactured by JASCO Corporation using a thermoformed press sheet having a thickness of 0.2 mm.

The specific calculation was performed as follows. The ethylene content was determined using the infrared absorption spectrum formula (1) in which the wave number region of 950 cm ^{−1 to} 550 cm ⁻¹ was integrated 4 times and only the wave number was doubled and recorded.

[0027]

[Equation 1]

However,

[0029]

[Equation 2]

Here, the full width at half maximum of the peak at Γ ₇₂₀ : ₇₂₀ cm ⁻¹ (nm), the peak width at Γ ₁ : 726 cm ⁻¹ (nm), the absorbance at A ₇₂₀ : ₇₂₀ cm ^−1, the absorbance at A ₉₀₀ : 726 cm ⁻¹ , , The range of E _{b that} can be quantified is 2.5 ≦ E _b ≦ 40.
It is 0. 3. Flexural Modulus Complies with ASTM D790 4. Drop weight impact strength (DuPont impact test method manufactured by Toyo Seiki Co., Ltd.) Asahi method: A 2 mm thick injection-molded sheet is placed on a percussion fixture (saucepan) for 1/2 inch diameter φ, and the tip is a diameter. A weight having a 1/2 inch φ hemispherical hammer core was dropped and the breaking strength thereof was measured. 5. Complies with Hikarizawa ASTM D523

[0031]

Example 1 <Solid preparation of the catalyst component> (I) was synthesized from synthesis advance triethylaluminum and dibutylmagnesium alkoxy group-containing organomagnesium component, composition formula _{Al · Mg 6 (C 2 H} 5) 3 (n-
Organomagnesium complex component 25 represented by C ₄ H ₉ ) ₁₂
0 mmol (based on magnesium) of a solution of n-heptane was placed in a 1 liter flask which had been sufficiently purged with nitrogen, cooled in an ice bath and stirred while n-fusing from a dropping funnel.
Butyl alcohol (22.8 cc, 250 mmol) was slowly added dropwise over 1 hour to cause a reaction, and the mixture was further reacted at room temperature for 1 hour with stirring. A colorless transparent solution was obtained and analyzed to find that the solution contained 0.96 mol of n-butoxy group per 1 mol of Mg and had a magnesium concentration of 1.0 mol / liter. (II) Synthesis of Magnesium-Containing Solid by Reaction with Chlorosilane Compound To a 1-liter flask sufficiently replaced with nitrogen, 500 mmol of trichlorosilane as a 1 mol / liter n-heptane solution was charged and kept at 65 ° C. with stirring. ,
A total amount of the n-heptane solution of the above-mentioned alkoxy group-containing organomagnesium component was added over 1 hour, and the mixture was further reacted at 65 ° C. for 1 hour with stirring.

The white solid produced was filtered off, washed thoroughly with n-hexane and dried to give a white solid 29.5.
g was obtained. As a result of analyzing this solid component, M in 1 g of solid
It contained g of 7.45 mmol, Cl of 14.2 mmol and butoxy group of 2.32 mmol and had a specific surface area of 198 m ² / g measured by the BET method. (III) Synthesis of Solid Catalyst Component 10 g of the solid obtained in (II) above and titanium tetrachloride 200 were placed in a 500 cc flask that had been sufficiently replaced with nitrogen.
cc and 50 cc of 1,2-dichloroethane were added, and further 2.0 cc (7.5 mmol) of di-n-butyl phthalate was added, and the mixture was reacted at 100 ° C. for 2 hours with stirring.

After the reaction, a solid was collected by filtration, and the solid was further suspended in 200 cc of tetrasalt titanate.
The reaction was carried out at 20 ° C for 2 hours. After the completion of the reaction, the solid was separated by hot filtration, thoroughly washed with hot n-heptane, and further washed with n-hexane to obtain a solid catalyst component as an n-hexane slurry. When a part of this was taken and analyzed, the Ti content in the solid catalyst component was 2.6% by weight. <Polymerization> Polymerization was carried out by using a process in which two reactors with stirring having an internal volume of 200 liter, each having a stirring bed made of finely powdered polypropylene, were connected. First, while continuously feeding propylene and hydrogen while maintaining the first-stage reactor under the conditions of a Froude number of 2.2 and a polymerization temperature of 70 ° C. and a polymerization pressure of 28 kg / cm ² , The solid catalyst component, triethylaluminum, and diphenyldimethoxysilane were continuously fed to initiate polymerization. At that time, the polymerization rate in the first stage was 22 kg.
/ Hr, MFI of the produced polymer is 4.5 (g / 10 mi
The catalyst feed amount and hydrogen feed amount were controlled so as to be n). Regarding the feed ratio of each catalyst component, polymerization was carried out under the conditions that the molar ratio of triethylaluminum to Ti in the solid catalyst component was 1: 400, and ethylaluminum to Si in the alkoxysilane was 1:10.

The polymer product polymerized in the first stage was sent to the reactor in the second stage together with propylene gas, and ethylene was newly fed to continuously polymerize the propylene-ethylene copolymer. The polymerization conditions are as follows: the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor is 70:30, and the polymerization temperature is 55 ° C.
The polymerization pressure was controlled so that the ratio of the amount of polymer produced in the first stage to the amount of polymer produced in the second stage was 76:24, and the produced powder was continuously extracted. To the obtained polymer powder, 0.05% by weight of P-EPQ (manufactured by Sand Co.) and 0.1% by weight of calcium stearate were added as additives, and pelletized at 220 ° C. by a twin-screw extruder.

Using this pellet, a test piece for flexural modulus was measured by an injection molding machine at a temperature of 280 ° C., and 2 × 150 × 150 m for evaluation of drop weight impact strength and gloss.
A flat plate having a shape of m was prepared. The ethylene content of the obtained copolymer was 10.2% by weight and the MFI was 2.1 (g / 10).
min), the weight ratio (f ₁ ) of the 1,2,4-trichlorobenzene-soluble component at 30 ° C. is 12.7 (wt%),
The weight ratio (f ₂ ) of the 1,2,4-trichlorobenzene-insoluble component at 120 ° C was 25.3 (% by weight). The evaluation results of the physical properties are shown in Table 1.

[0036]

Example 2 In the second stage, the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor was set to 65:35, and the ratio of the amount of polymer produced in the first stage and the amount of polymer produced in the second stage. Polymerization was carried out in the same manner as in Example 1 except that the ratio was changed to 73:27. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0037]

Example 3 In the second stage, the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor was set to 55:45, and the amount of polymer produced in the first stage and the amount of polymer produced in the second stage were changed. Polymerization was carried out in the same manner as in Example 1 except that the ratio was changed to 77:23. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0038]

Example 4 The MFI of the polymer produced in the first stage is 15.0.
The catalyst feed amount and hydrogen feed amount were controlled so as to be (g / 10 min). The polymer polymerized in the first stage was sent to the reactor in the second stage together with propylene gas, and ethylene was newly fed to continuously polymerize the propylene-ethylene copolymer. The second stage polymerization conditions are
The partial pressure ratio of propylene and ethylene in the mixed gas in the reactor was 70:30, the polymerization temperature was 55 ° C, and the ratio of the amount of polymer produced in the first stage and the amount of polymer produced in the second stage was 82:18.
The polymerization pressure was controlled so as to become, and the hydrogen feed amount was controlled so that the MFI of the polymer produced in the second stage was 8 (g / 10 min), and the produced powder was continuously extracted. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0039]

Example 5 The MFI of the polymer produced in the first stage is 30.0.
The catalyst feed amount and hydrogen feed amount were controlled so as to be (g / 10 min). The polymer polymerized in the first stage was sent to the reactor in the second stage together with propylene gas, and ethylene was newly fed to continuously polymerize the propylene-ethylene copolymer. The second stage polymerization conditions, the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor is 75:25, the polymerization temperature is 55 ° C, the amount of polymer produced in the first stage and the amount of polymer produced in the second stage The polymerization pressure was controlled so that the ratio was 80:20, and the hydrogen feed amount was controlled so that the MFI of the polymer produced in the second stage was 15 (g / 10 min), and the produced powder was continuously produced. I pulled it out. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0040]

[Example 6] The MFI of the first-stage formed polymer was 5.0.
The catalyst feed amount and hydrogen feed amount were controlled so as to be (g / 10 min). The polymer polymerized in the first stage was sent to the reactor in the second stage together with propylene gas, and ethylene was newly fed to continuously polymerize the propylene-ethylene copolymer. The polymerization conditions for the second stage are as follows: the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor is 80:20, the polymerization temperature is 55 ° C., the amount of polymer produced in the first stage and the amount of the polymer produced in the second stage. Polymer production ratio is 9
The polymerization pressure was controlled so as to be 4: 6, and the MFI of the polymer produced in the second stage was 4.0 (g / 10 mi).
The amount of hydrogen feed was controlled so as to be n).
Further, the polymer product polymerized in the second stage was sent to the reactor in the third stage together with propylene gas, and ethylene was newly fed to polymerize the propylene-ethylene copolymer. The polymerization conditions for the third stage were as follows: the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor was 65:35, and the polymerization temperature was 55.
The polymerization pressure was controlled so that the ratio of the amount of polymer produced in the first and second stages to the amount of polymer produced in the third stage was 86:14, and the produced powder was continuously extracted. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0041]

Comparative Example 1 In the second stage, the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor was set to 10:90, the amount of the polymer produced in the first stage and the polymer produced in the second stage.
Polymerization was carried out in the same manner as in Example 1 except that the amount ratio was changed to 87:13. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0042]

Comparative Example 2 Polymerization was carried out in the same manner as in Example 2 except that the ratio of the amount of polymer produced in the first stage and the amount of polymer produced in the second stage was changed to 53:47. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0043]

Comparative Example 3 Polymerization was carried out in the same manner as in Example 3 except that the ratio of the amount of polymer produced in the first stage and the amount of polymer produced in the second stage was changed to 67:33. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0044]

[Comparative Example 4] In the second stage, the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor was set to 10:90, the amount of the polymer produced in the first stage and the polymer produced in the second stage. -Polymerization was carried out as in Example 3 except that the amount ratio was changed to 90:10. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0045]

Comparative Example 5 Polymerization was carried out in the same manner as in Example 5 except that the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor in the second stage was changed to 10:90. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0046]

Comparative Example 6 In the second stage, the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor was set to 70:30, and further, the polymer produced in the first stage and the polymer produced in the second stage. Is 85:15, and the partial pressure ratio of propylene and ethylene in the mixed gas in the reactor in the third stage is 10:
90, and the amount of polymer produced in the first and second stages,
Polymerization was carried out in the same manner as in Example 6 except that the ratio of the amount of polymer formed in the third stage was changed to 95: 5. Table 1 shows the analysis results of the obtained polymer and the evaluation results of its physical properties.

[0047]

[Table 1]

[0048]

As described above, the propylene ethylene block copolymer of the present invention is remarkably excellent in the balance of rigidity, impact resistance, particularly falling weight impact strength, and surface gloss. Therefore, if the propylene ethylene block copolymer of the present invention is used for various industrial or household parts that are required to have rigidity, impact resistance and surface gloss, the requirements can be satisfied.

Claims (1)

[Claims] 1. With magnesium, halogen and titanium
Containing at least a solid catalyst component as a constituent component thereof
In the presence of a stereoregular catalyst, olefins are weighted in multiple stages.
Propylene ethylene block obtained by combining
(A) ethylene-containing copolymer
Quantity (E_b3) to 20% by weight, (B) at 30 ° C
Weight ratio of soluble 1,2,4-trichlorobenzene
(F ₁) Is larger than the ethylene content of (A), and
(C) 1,2,4-trichlorobenze at 120 ° C
Insoluble matter weight ratio (f₂) And f above₁Ratio with (f₂
/ F₁) Is 0.7 to 4.0.
Propylene ethylene block copolymer.