JP2000119318A - Propylene-based block copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a propylene-based block copolymer having a high impact resistance and good in powder characteristics. SOLUTION: This propylene-based block copolymer comprises a propylene- based block copolymer produced by using an Mg/Ti/halogen-based catalyst comprising an Al compound having 4-10 number of carbon atoms and a silicon compound having an alkoxy group having 2-10 number of carbon atoms and an EPR block having 20-80 wt.% of ethylene content. The content of the EPR block is 20-80 wt.% based on the whole polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a high impact resistance,
The present invention also relates to a propylene block copolymer excellent in powder fluidity and a method for producing the same. In general, when the content of the rubbery copolymer is increased to improve the impact resistance of the propylene-based block copolymer, the powder fluidity of the polymer is deteriorated, and adhesion or blockage occurs in a reactor or a pipe, resulting in production. In many cases, the performance is reduced.

[0002]

2. Description of the Related Art As a method of improving this, a method of producing a block copolymer by stepwise polymerizing propylene with ethylene or other olefins is well known. (JP-B-43-11230, JP-B-44-11230)
No. 16668, JP-B-44-20621, JP-B-49-24593, JP-B-49-30264
JP, JP-A-48-25781, JP-A-50-5881
115296, JP-A-53-35789,
JP-A-54-10072 and the like.

However, when propylene and ethylene are polymerized in two or multiple stages, the impact resistance is improved, but a problem arises in that a large amount of low-crystalline copolymer is by-produced in the product. . Therefore, many attempts have been made to reduce by-product low-crystalline components. On the other hand, titanium trichloride type catalysts are well known as catalysts for the stereoregular polymerization of olefins, but these catalysts have a low activity and require a relatively large amount of use. Many, therefore, require a catalyst removal step.

As a method for greatly increasing the activity so that the catalyst removal step can be omitted, various techniques for introducing a magnesium compound into a solid catalyst component have been proposed (Japanese Patent Publication No. Sho 3 (1988)).
9-12105, JP-B-47-41676, JP-B-47-46269, and the like. However, when olefins are polymerized by these methods, the activity is high but the amount of low-crystalline components produced as by-products is increased, which is still insufficient for practical use.

[0005]

An object of the present invention is to provide a propylene block copolymer having high impact strength and good powder properties, and a catalyst capable of producing the same with high activity. It is to provide a manufacturing method used.

[0006]

The present inventors have solved the above-mentioned problems by using a specific organoaluminum compound as a cocatalyst combined with a magnesium-containing solid catalyst and further using a specific organosilicon compound as a third component. And arrived at the present invention. That is, the gist of the present invention is to provide a propylene homopolymer or an ethylene-propylene copolymer having an ethylene content of 7% by weight or less, produced using a catalyst comprising a contact product of the following components (A) to (C). A block composed of coalescing (hereinafter referred to as "block (I)") and an ethylene content of 20 to 80% by weight
(Hereinafter referred to as “block (II)”), comprising a block (II) in the block copolymer
In a propylene-based block copolymer having a content of 20 to 80% by weight. Component (A): magnesium (Mg), titanium (Ti),
Solid catalyst component containing halogen (X) and electron donating compound Component (B): organoaluminum compound represented by the following general formula (1)

[0007]

Embedded image AlR ¹ _n Cl _3-n (1)

In the formula, R ¹ is an alkyl group having 4 to 10 carbon atoms, and n is a number of 2 to 3. Component (C): an organosilicon compound represented by the following general formula (2) or (3)

[0009]

Embedded image R ² R ³ Si (OR ⁴ ) ₂ (2)

[0010]

Embedded image R ² Si (OR ⁴ ) ₃ (3)

In the formula, R ² is a branched alkyl group or cycloalkyl group having 4 to 12 carbon atoms, R ³ is an alkyl group or cycloalkyl group having 1 to 12 carbon atoms, and R ⁴ is 2 carbon atoms. 10 to 10 alkyl groups.

Another aspect of the present invention is to provide a method for producing the propylene-based block copolymer, which comprises a polymerization step comprising the following steps (a) and (b):
Also exists. Step (a) Propylene or an ethylene / propylene mixture is formed using the above-mentioned catalyst to form a propylene homopolymer or an ethylene-propylene copolymer having an ethylene content of 7% by weight or less, in an amount of 20 to 80% by weight based on the total amount of the produced polymer. Step (b): A rubbery ethylene-propylene copolymer having an ethylene content of 20 to 80% by weight is converted from the ethylene / propylene mixture to the 80
~ 20% by weight.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION <Catalyst> The catalyst components used for producing the block copolymer of the present invention are specified three components, (A),
It consists of the contact products of (B) and (C).
In the present invention, components other than the above components may coexist as long as the effects are not impaired.

Component (A) The catalyst component (A) used in the present invention is magnesium (M)
g), titanium (Ti), halogen (X) and an electron donating compound. As the magnesium compound serving as the magnesium source of the component (A), magnesium dihalide, dialkoxymagnesium, alkoxymagnesium halide, magnesium oxyhalide,
Dialkyl magnesium, alkyl magnesium halide, magnesium oxide, magnesium hydroxide, magnesium carboxylate and the like can be used.

Of these, magnesium dihalides such as magnesium chloride, magnesium bromide, and magnesium iodide, dialkoxymagnesium, and alkoxymagnesium halide are preferred, and magnesium chloride is particularly preferred. It is preferable that these magnesium compounds contain no water or anhydrous salts.

As a titanium compound serving as a titanium source,
Is represented by the general formula Ti (OR^Five)_4-pX_p(Where R^FiveIs
Alkyl group (preferably having about 1 to 10 carbon atoms)
X represents a halogen, and p is a number satisfying 0 ≦ p ≦ 4)
Are preferred, for example, TiCl_Four, T
iBr_Four, Ti (OC_TwoH_Five) Cl_Three, Ti (OC_TwoH
_Five)_TwoCl_Two, Ti (OC_TwoH_Five)_ThreeCl, Ti (O-
i-C_ThreeH₇) Cl_Three, Ti (On-C_FourH₉) Cl
_Three, Ti (On-C_FourH₉)_TwoCl_Two, Ti (OC_Two
H_Five) Br_Three, Ti (OC_TwoH_Five) (On-C)
_FourH₉)_TwoCl, Ti (On-C_FourH₉)_ThreeCl, T
i (OC₆H_Five) Cl_Three, Ti (OiC_FourH ₉)_Two
Cl_Two, Ti (OC_FiveH₁₁) Cl_Three, Ti (OC
₆H₁₃) Cl_Three, Ti (OC_TwoH_Five)_Four, Ti (On-
-C_ThreeH₇)_Four, Ti (On-C_FourH₉)_Four, Ti
(On-C_FourH₉)_Four, Ti (On-C
₆H₁₃)_Four, Ti (On-C ₈H₁₇)_Four, Ti (OC
H_TwoCH (C_TwoH_Five) C_FourH₉)_FourEtc.
Wear.

Also, TiCl ₃ (including those obtained by reducing TiCl ₄ with hydrogen, aluminum metal, or organometallic compound), TiBr ₃ , Ti (OC ₂ H ₅ ) C
titanium compounds such as l ₂ can be used. Among these titanium compounds, titanium tetrachloride is particularly preferred. When the halogen in the component (A) is a halide thereof as the magnesium and / or titanium source described above,
Usually supplied from these compounds, other halogen sources, for example aluminum halides such as AlCl ₃ or silicon halides such as SiCl ₄ , PC
It may be supplied from a halogenating agent such as a phosphorus halide such as l ₃ and PCl ₅ , a tungsten halide such as WCl ₆ , and a molybdenum halide such as MoCl ₅ . The halogen contained in the component (A) is generally fluorine, chlorine, bromine, iodine or a mixture thereof,
Among them, chlorine is preferred.

Further, the solid catalyst component (A) must contain an electron donating compound. Examples of the electron donating compound (internal donor) used herein include alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, and acid anhydrides. Electron-donating compounds such as phenols, nitrogen-containing electron-donating compounds such as ammonia, amines, nitriles, isocyanates and nitro compounds, and sulfur-containing electron-donating compounds such as sulfonic esters and sulfonic halides. .

Among these electron donating compounds, carboxylic acid esters, carboxylic acid halides and ketones are nitrogen-containing compounds as amines, nitriles and nitro compounds as oxygen-containing compounds, and sulfonic acid esters as sulfur-containing compounds. And sulfonic acid halides are preferred. Specific examples are shown below. Carboxylic acid esters include aliphatic and aromatic carboxylic acid esters,
Examples of the aliphatic carboxylic acid ester include ethyl acetate, methyl acetate cellosolve, ethyl acetate cellosolve, methyl methacrylate, diethyl oxalate, and dibutyl maleate. Examples of the aromatic carboxylate include ethyl benzoate, methyl p-toluate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate and the like.

Examples of the carboxylic acid halide include acetyl chloride, benzoyl chloride, benzoyl bromide, phthaloyl chloride, and phthaloyl bromide. The ketone is preferably a diketone,
Examples of the aliphatic chain diketone include 2,5-hexanedione, acetylacetone, cis-1,2-diacetylethylene, 3-chloroacetylacetone, and 3,4-hexanedione. Examples of the aliphatic cyclic diketone include 1,4-cyclohexanedione and 1,2-cyclohexanedione.
Cyclohexanedione, 1,3-cyclohexanedione, dimedone, camphorquinone, α-acetyl-γ-
Butyrolactone, N-acetyl-ε-caprolactam,
α-acetyl-α-methyl-γ-butyrolactone and the like can be exemplified. As the aromatic diketone, o-
Acetylacetophenone, o-benzoylacetophenone, o-benzoylbenzophenone, 1,8-diacetylnaphthalene, 1,8-dibenzoylnaphthalene, 3-
Phenylacetylacetone, 1-phenyl-1,2-propanedione, benzoylacetone, benzoyltrifluoroacetone, 2-acetyl-1-tetralone, β-
Examples include naphthoquinone and phenanthraquinone.

As the amine, a diamine is preferable, and tetramethylene diamine, 1,4-cyclohexyldiamine, isophoronediamine, 4-aminopiperidine, α,
α'-diamino-o-xylene, α, α'-diamino-
m-xylene, α, α′-diamino-p-xylene, o
-Aminoaniline, m-aminoaniline and the like. Among the nitrile compounds, dinitrile is preferable, and malondinitrile, dinitrile succinate, 1,4-
Examples include cyclohexyldinitrile, azobis-2-cyanopropane, nitrile tetramethylsuccinate, phthalonitrile, isophthalonitrile, dithianone, and the like.

Examples of the nitro compound include aromatic or aliphatic mono- and dinitro compounds, and those having a substituent. Among the aromatic nitro compounds, nitrobenzene, o-nitrotoluene, o-dinitrobenzene, m-dinitrobenzene, p
-Dinitrobenzene, 2,3-dinitrotoluene, 3,
4-dinitrotoluene, o-nitrophenol, m-nitrophenol, o-nitroaniline, m-nitroaniline, o-nitrobenzonitrile, o-nitroacetophenone, o-nitrobenzophenone, m-nitrobenzophenone, 1,8- Examples thereof include dinitronaphthalene, 2,3-dinitronaphthalene, and 1,5-dinitronaphthalene. In aliphatic nitro compounds, 2-nitro-n-butane, nitrocyclohexane, 1,2-dinitroethylene, 1-nitro-2-acetylethylene,
Examples thereof include 1-nitro-2-aminoethylene, 1,2-dinitrocyclohexane, 1-nitro-2-acetylcyclohexane, 1-nitro-2-cyanocyclohexane, and the like.

Examples of the sulfonic acid ester include n-butyl benzenesulfonate, ethyl benzenesulfonate, m-
Di-n-butyl benzenedisulfonate, diethyl o-benzenedisulfonate, ethyl cyclohexanesulfonate,
Examples include isobutyl ethanesulfonate, isobutyl o-nitrobenzenesulfonate, and ethyl o-acetylbenzenesulfonate.

Examples of the sulfonic acid halide include benzenesulfonyl chloride, benzenesulfonyl bromide, m-
Examples thereof include benzenedisulfonyl chloride, o-benzenedisulfonyl chloride, cyclohexanesulfonyl chloride, ethanesulfonyl chloride, o-nitrobenzenesulfonyl chloride, and m-benzoylbenzenesulfonyl chloride.

Among the above electron donating compounds, particularly preferred are carboxylic esters, carboxylic halides,
Sulfonic acid halides and nitro compounds, specifically, dibutyl phthalate, flotile chloride, benzenesulfonyl chloride, m-benzenedisulfonyl chloride, o-benzenedisulfonyl chloride, o-nitrobenzenesulfonyl chloride, o-dinitrobenzene ,
1,8-dinitronaphthalene and the like.

The component (A) can be produced by bringing the respective components constituting the component (A) and, if necessary, other optional components into contact all at once or sequentially. When producing the component (A), a hydrocarbon solvent (n-hexane, n-heptane, toluene, cyclohexane, etc.) may be appropriately used.
Washing may be performed using an organic solvent such as a halogenated hydrocarbon (n-butyl chloride, 1,2-dichloroethane, carbon tetrachloride, chlorobenzene, etc.).

The contact conditions of each component constituting the above-mentioned component (A) are as follows: in the absence of oxygen, generally at a contact temperature of -50 to 200 ° C., preferably 0 to 100 ° C .; In the presence or absence of the agent, the reaction is performed using a mechanical contact device such as a rotary ball mill, a vibration mill, a jet mill, and a stirring mixer. As the inert diluent, aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, polysiloxanes and the like can be used.

When magnesium chloride is used as the magnesium (and halogen) source of the component (A), it is desirable to perform the following preliminary treatment by grinding or dissolving / precipitating. The pulverization of magnesium chloride can be performed using a ball mill or a vibration mill. The dissolution of magnesium chloride can be carried out using a hydrocarbon or a halogenated hydrocarbon as a solvent and using an alcohol, a phosphoric acid ester, or a titanium alkoxide as a dissolution promoter. The dissolved magnesium chloride can be precipitated by adding a poor solvent, an inorganic halide, an electron-donating compound such as an ester, or methylhydrogenpolysiloxane. For details of such pretreatment of magnesium chloride, see, for example, JP-A-53-45688, JP-A-54-31092, JP-A-57-180612, JP-A-58-5309, or JP-A-58-5310. Has been described.

The order of contact of the pretreated magnesium chloride, titanium halide and electron donating compound is such that even if they are contacted simultaneously and collectively, a complex of titanium halide and electron donating compound is formed. Therefore, even if this complex is brought into contact with magnesium chloride, or if magnesium chloride is brought into contact with titanium halide and then brought into contact with an electron-donating compound, magnesium chloride is brought into contact with the electron-donating compound and then halogenated. You may make it contact with titanium oxide. The titanium content in the component (A) thus produced is preferably 0.1 to 20% by weight, and the molar ratio between the electron donating compound and titanium is preferably about 0.05 to 2.0. .

Component (B) (Organic Aluminum Compound) The organoaluminum compound used in the present invention is a compound represented by the general formula AlR ¹ _n Cl _3-n . (Wherein, R ¹ is an alkyl group having 4 to 10 carbon atoms;
Is a number of 2-3. Specific examples of such organoaluminum compounds include trialkylaluminums such as triisobutylaluminum, tri-n-hexylaluminum, trioctylaluminum, tridecylaluminum, diisobutylaluminum monochloride, din-hexylaluminum monochloride, dioctylaluminum Examples thereof include monoalkylides and dialkylaluminum monochlorides such as didecylaluminum monochloride. Component (B) is used in an amount of component (B) / component (A)
Is preferably in the range of 0.1 to 1000, preferably 1 to 100.

[0031]Component (C) (organosilicon compound) Component (C) used in the present invention has a general formula R^TwoR^ThreeSi
(OR^Four)_TwoOr R ^TwoSi (OR^Four)_ThreeRepresented by
It is an organosilicon compound. Where R^TwoIs from 4 carbon atoms
12-branched alkyl group or cycloalkyl
Group, R^ThreeIs an alkyl group having 1 to 12 carbon atoms or
Chloroalkyl group, R^FourIs alkyl having 2 to 10 carbon atoms
Group. Specific examples include the following compounds.

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

The molar ratio of component (C) (organosilicon compound) to component (B) (organoaluminum compound) is such that the value of the ratio of component (C) / component (B) is 0.01 to 1.0, Preferably, it is good to be in the range of 0.02 to 0.5.

Formation of Catalyst The catalyst used in the present invention is a product obtained by bringing the above components (A) to (C) into contact. This contact may be performed by simultaneously adding the components at once,
The addition may be performed stepwise and sequentially. In this case, the order of addition of each component may be arbitrarily determined. Further, this catalyst may be formed in advance outside the polymerization system or may be formed simultaneously with the polymerization inside the polymerization system.

<Polymerization Step> The polymerization step of the present invention carried out in the presence of the above-mentioned catalyst component includes at least two steps, step (a) and step (b). Either of step (a) and step (b) may be performed first, but (a) →
It is industrially advantageous to carry out in the order of (b).

Step (a) In step (a), propylene alone or an ethylene / propylene mixture is supplied to a polymerization system having a catalyst comprising the contact product of the above components (A), (B) and (C). The polymerization is carried out in one stage or in multiple stages to obtain a propylene homopolymer or ethylene content of 7% by weight or less, preferably 0.1% by weight or less.
An ethylene / propylene copolymer of 5% by weight or less is used in an amount of 20 to 80% by weight, preferably 30 to 70% by weight of the total amount of the produced polymer.
This is a step of forming a weight%. When the ethylene content in the ethylene / propylene copolymer obtained in the step (a) exceeds 7% by weight, the bulk density of the finally formed block copolymer decreases, and the by-product of the low crystalline polymer is produced. The amount is greatly increased. The weight ratio of the polymer formed in this step (a) to the total polymer is the lower limit of the above range (20% by weight).
If it is less than 3, the by-product amount of the low crystalline polymer also increases.
On the other hand, if this polymerization ratio exceeds the upper limit of the above range (80% by weight), the effect of improving the impact resistance, which is a feature of the block copolymer of the present invention, cannot be obtained. The polymerization temperature in step (a) is 30 to 100 ° C., preferably about 50 to 90 ° C., and the polymerization pressure is usually in the range of 1 to 50 kg / cm ² G. In the step (a), it is preferable to control the melt flow rate (MFR) using a molecular weight modifier such as hydrogen to increase the fluidity of the finally formed block copolymer at the time of melting.

Step (b) In step (b), an ethylene / propylene mixture having an ethylene content of 20 to 80% by weight is obtained by polymerizing the ethylene / propylene mixture in one or more stages using the above-mentioned specific catalyst. This is a step in which the coalescence is formed in an amount of 20 to 80% by weight, preferably 30 to 70% by weight based on the total amount of the produced polymer. If the ethylene content of the ethylene / propylene copolymer produced in the step (b) is less than 20% by weight or more than 80% by weight, the impact resistance of the finally obtained block copolymer is lowered. In the step (b), for example, 1-butene,
Comonomers other than ethylene and propylene, such as α-olefins such as 1-pentene and 1-hexene, may coexist. The polymerization temperature in the step (b) is 30 to 90.
° C, preferably about 50 to 80 ° C. The polymerization pressure is
A range of 1 to 50 kg / cm ² G is usually used. When moving from the step (a) to the step (b), it is preferable to purge the propylene gas or the propylene / ethylene mixed gas and the hydrogen gas to the outside of the system, and then proceed to the next step. When it is desired to further increase the impact resistance of the block copolymer finally obtained in the step (b), it is preferable to carry out this step in the substantial absence of a molecular weight modifier.

Polymerization Mode The process for producing the copolymer of the present invention can be carried out by any of batch, continuous and semi-batch processes. At this time, there are a method of performing polymerization using the monomer itself used as a medium, a method of performing polymerization in a gaseous monomer without using a medium, and a method of performing polymerization by combining these. Prior to the main polymerization, preliminary polymerization using a solid catalyst can be carried out under milder conditions than the main polymerization (JP-A-55-71712, JP-A-56-578).
No. 14, etc.).

[0041]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. <Example 1> (1) Preparation of component (A) In a three-necked glass flask (with a thermometer and a stirrer) having a 500 ml internal volume purged with nitrogen, 75 ml of dehydrated and deoxygenated purified heptane and 75 ml of titanium tetra Butoxide, 10 g of anhydrous magnesium chloride is added. After heating to 90 ° C. and completely dissolving the magnesium chloride over 2 hours, the mixture is cooled to 40 ° C., and 15 ml of methyl hydrogen polysiloxane is added to precipitate a magnesium chloride / titanium tetrabutoxide complex. After washing with purified heptane, 8.7 ml of silicon tetrachloride and 2.0 g of phthaloyl chloride are added, and the mixture is kept at 50 ° C. for 2 hours. Thereafter, the resultant is washed with purified heptane, 25 ml of titanium tetrachloride is further added, and the mixture is kept at 25 ° C. for 2 hours. This was washed with purified heptane to obtain component (A). The titanium content in the component (A) obtained here was 2.7% by weight.

(2) Block copolymerization A block copolymerization was carried out by a method disclosed in JP-B-61-33721 using a horizontal biaxial gas-phase polymerization tank having an internal volume of 13 liters. After sufficiently purging the inside of the polymerization tank with purified nitrogen, 400 g of a sufficiently dehydrated and deoxygenated polymer carrier was added. Next, 500 mg of triisobutylaluminum was introduced as the component (B), 120 mg of the component (A) synthesized above, and 150 mg of tert-butylmethyldiethoxysilane were introduced as the component (C).

In the first polymerization step (a), hydrogen is added to 1
After introducing 000 ml, the temperature was raised to 75 ° C., and propylene was supplied at a constant rate of 3 g / min. In addition, the stirring rotation speed of the polymerization tank was 350 rpm. After the polymerization was performed for 3 hours while maintaining the polymerization temperature at 75 ° C., the supply of propylene was stopped. Continuously maintain the system at 75 ° C and the pressure in the system is 1kg
/ Cm ² G, propylene and hydrogen were purged out of the system to terminate the polymerization step (a).

The polymerization step (b) was started by supplying monomers to the polymerization tank after the completion of the step (a) at a constant rate of 1.5 g / min of propylene and 1.5 g / min of ethylene. . After the monomer supply was continued for 3 hours while maintaining the temperature at 70 ° C., the supply was stopped and the polymerization pressure was reduced to 1 kg /
The polymerization was continued until cm ² G was reached. When the pressure became equal to or less than the predetermined pressure, the monomer was purged to obtain 1045 g of a block copolymer. The MFR of the resulting copolymer was 2.3 g /
The rubbery ethylene-propylene copolymer produced in the step (b) was measured for 10 min, the bulk density was 0.44 g / cm ³ , and the xylene-soluble matter was measured at 23 ° C.
It was 3% by weight. The ethylene content of this rubbery copolymer was 55.1% by weight. This block copolymer was pelletized by using an extruder, and this was injection-molded to a thickness of 4 mm.
mm sheet and the Izod impact strength (-50
° C) was measured according to ASTM-D-790. Table 1 shows the measurement results.

Comparative Example 1 A copolymer was prepared in the same manner as in Example 1 except that triethyl aluminum was used instead of triisobutyl aluminum in the block copolymerization. Table 1 shows the results.

Comparative Example 2 A copolymer was prepared in the same manner as in Example 1 except that tert-butylmethyldimethoxysilane was used instead of tert-butylmethyldiethoxysilane in the block copolymerization. Table 1 shows the results.

Example 2 A copolymer was prepared in the same manner as in Example 1, except that tert-butylmethyldibutoxysilane was used instead of tert-butylmethyldiethoxysilane in the block copolymerization. Table 1 shows the results.

Example 3 A copolymer was prepared in the same manner as in Example 1 except that tri-n-hexylaluminum was used instead of triisobutylaluminum in block copolymerization. Table 1 shows the results.

<Evaluation of Results> In Comparative Examples 1 and 2 in which the component (B) or the component (C) is out of the range of the present invention from the data in Table 1, the powder flowability of the produced polymer is inferior, and It can be seen that the density is low. Further, it can be seen that the copolymer itself has a similar composition, but has lower impact resistance than the copolymer of the present invention.

[0050]

[Table 1]

[0051]

The block copolymer according to the present invention has good powder properties despite the large proportion of the rubbery copolymer, and is free from troubles such as polymer adhesion and blockage of piping during production. Less likely to happen. Also, it has high impact resistance and is excellent in quality.

[Brief description of the drawings]

FIG. 1 is a flowchart for helping to understand the present invention.

Continued on the front page F-term (Reference) 4J026 HA03 HA04 HA27 HA35 HA48 HA49 HB02 HB03 HB04 HB35 HB43 4J028 CB64A CB68A CB74A CB80A CB81A DB03A DB04A DB05A EA01 EA02 EB02 EB04 EC02 GA03 FA03

Claims (2)

[Claims] 1. A propylene homopolymer or an ethylene-propylene copolymer having an ethylene content of 7% by weight or less, produced using a catalyst comprising a contact product of the following components (A) to (C): Block (hereinafter referred to as "block (I)") and ethylene content of 20 to 80% by weight
(Hereinafter referred to as “block (II)”), comprising a block (II) in the block copolymer
Is a propylene-based block copolymer having a content of 20 to 80% by weight. Component (A): magnesium (Mg), titanium (Ti),
Solid catalyst component containing halogen (X) and an electron donating compound Component (B): an organoaluminum compound represented by the following general formula (1): AlR ¹ _n Cl _3-n (1) ¹ is an alkyl group having 4 to 10 carbon atoms,
n is a number of 2-3. Component (C): The following general formula (2)
Or an organosilicon compound represented by (3): R ² R ³ Si (OR ⁴ ) ₂ (2) R ² Si (OR ⁴ ) ₃ (3) wherein R ² is a carbon atom An alkyl group or a cycloalkyl group having 4 to 12 branches, and R ³ has 1 to 1 carbon atoms.
12 alkyl groups or cycloalkyl groups, and R ⁴ is an alkyl group having 2 to 10 carbon atoms. 2. The method for producing a propylene-based block copolymer according to claim 1, wherein the method comprises a polymerization step including the following steps (a) and (b). Step (a) A propylene homopolymer or an ethylene-propylene copolymer having an ethylene content of 7% by weight or less is produced from propylene or an ethylene / propylene mixture by using the catalyst according to claim 1 in an amount of 20 to 20% of the total polymer production amount. A step of forming 80% by weight of the ethylene / propylene mixture using the catalyst according to claim 1, wherein the ethylene content is 20 to 80% by weight.
Forming the rubbery ethylene-propylene copolymer of 80 to 20% by weight based on the total amount of the produced polymer.