JP2000336130A - Propylene-ethylene block copolymer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a propylene-ethylene block copolymer which is a true polypropylene-b-poly(ethylene-co-propylene) comprising a polypropylene segment chemically bound to a poly(ethylene-co-propylene) segment, has >=500,000 Mw thereof and/or <=5 wt.% extraction ratio with n-heptane and is capable of changing the molecular weight distribution thereof to about 2-10 and to provide a method for producing the propylene-ethylene block copolymer. SOLUTION: This propylene-ethylene block copolymer is the one comprising a polypropylene-b-poly(ethylene-co-propylene) and has >=500,000 Mw of the propylene-ethylene block copolymer. The method for producing the polypropylene-ethylene block copolymer comprises (a) chemically binding the polypropylene segment to the poly(ethylene-co-propylene) segment and (b) synthesizing the polypropylene segment and the poly(ethylene-co-propylene) segment in the presence of an olefin polymerizing catalyst composed of a solid catalyst component comprising titanium and a halogen or the titanium, magnesium and the halogen and an organometallic compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a propylene / ethylene block copolymer having a chemical bond between a polypropylene segment and a poly (ethylene-co-propylene) segment. More specifically, using a solid catalyst component, an organometallic compound and a silicon compound as a catalyst, a polypropylene segment is polymerized to form a poly (ethylene-co-propylene) segment at the end of the polypropylene segment. The present invention relates to a propylene / ethylene block copolymer having a weight average molecular weight of 500,000 or more and / or a normal heptane extraction rate of 5% by weight or less, and a method for producing the same. The obtained propylene / ethylene block copolymer has excellent mechanical properties, especially excellent impact resistance, thermal properties, and transparency,
Among them, it is excellent in whitening resistance, molding materials such as injection molding, compression molding, vacuum molding, blow molding, extrusion molding, film and sheet molding, spinning materials, phases of crystalline polyolefin and amorphous or other crystalline polyolefin. It is useful as a solubilizer, especially a compatibilizer for polypropylene and polyethylene, or a modifier for polyolefins such as polypropylene or polyethylene.

[0002]

2. Description of the Related Art Polyolefins such as polypropylene and polyethylene are excellent in various physical properties (mechanical strength, heat resistance, chemical resistance, electric insulation, etc.) and workability, and are inexpensive. I have. However, for example, in the case of polypropylene, it has relatively high rigidity,
It is inferior in impact strength, and in order to improve this point, amorphous poly (ethylene-c
(o-propylene) to improve its properties by blending. In a conventional block-type copolymer, a matrix made of polypropylene and a domain made of poly (ethylene-co-propylene) are phase-separated, causing whitening due to separation between the matrix and the domain upon impact, and subsequent physical properties. Reduction has become a problem, and improvements have been demanded.

Heretofore, a block copolymer of polypropylene and poly (ethylene-co-propylene) has been known as one grade of polypropylene.
A two-stage polymerization method is used in which synthesis is performed in minutes to several hours, and then poly (ethylene-co-propylene) is synthesized in a second polymerization tank in 30 minutes to several hours. Considering the formation time per polymer chain, the block copolymer obtained by this method exists in a micro-blended state where polypropylene and poly (ethylene-co-propylene) are not chemically bonded. Therefore, it is not a block copolymer as defined by polymer chemistry, and therefore, the desired properties have not always been obtained sufficiently.

[0004] JP-A-8-92338, JP-A-9-92
No. 87343 discloses that a Ziegler catalyst or a metallocene catalyst is used, and the polymerization time of polypropylene and poly (ethylene-co-propylene) is set to a short time range in which a chain transfer reaction hardly occurs.
Using a tubular polymerization reactor, polypropylene and poly (ethylene
-co-propylene) to produce a true block copolymer having a chemical bond. However, in this production method, the yield of the obtained polypropylene-b-poly (ethylene-co-propylene) is low, a considerable amount of inorganic substances remains in the polymer, and the polymer quality is reduced, for example, the moldability is reduced, and fish is reduced. It causes eyes and the like.
In addition, the above-mentioned technology relates to polypropylene-b-poly (ethylene-co-propylene) having a weight average molecular weight of 500,000 or more and polypropylene-b-poly (ethylene-co-propylene) having a normal heptane extraction rate of 5% by weight or less. propylene)
Also, as described above, polypropylene-b-poly (ethylene-ethylene) having a high molecular weight or a low normal heptane extraction rate and capable of changing the molecular weight distribution (Mw / Mn) from about 2 to about 10
(co-propylene) is not disclosed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a true polypropylene in which a polypropylene segment and a poly (ethylene-co-propylene) segment are chemically bonded.
-b-poly (ethylene-co-propylene) having a weight average molecular weight of 500,000 or more and / or a normal heptane extraction rate of 5% by weight or less, and a molecular weight distribution thereof can be changed to about 2 to 10 An object of the present invention is to provide a propylene / ethylene block copolymer having features and a method for producing the same.

[0006]

SUMMARY OF THE INVENTION We have developed a true block copolymer, namely polypropylene and poly (ethylene).
-co-propylene) is chemically bonded, has a high molecular weight, a low normal heptane extraction rate, and can be changed in the molecular weight distribution. Was used as an external donor, and it was found that such problems could be solved by examining various polymerization conditions such as the length, residence time, and monomer ratio of each polymerization zone using a tubular reactor. The invention has been completed.

That is, the first aspect of the present invention is as follows:
A propylene / ethylene block copolymer comprising polypropylene-b-poly (ethylene-co-propylene) having the characteristic of (b), wherein the weight average molecular weight (Mw) of the propylene / ethylene block copolymer is 5
Propylene characterized by being not less than 00,000
An ethylene block copolymer is provided. (A) Polypropylene segment and poly (ethylene-c
o-propylene) segment. (B) A polypropylene segment and a poly (ethylene-co-propylene) segment are synthesized in the presence of titanium and a halogen or a solid catalyst component composed of titanium, magnesium and a halogen and an olefin polymerization catalyst composed of an organometallic compound. A second aspect of the present invention is a propylene / ethylene block copolymer comprising polypropylene-b-poly (ethylene-co-propylene), wherein the propylene / ethylene block copolymer has a weight average molecular weight (Mw) of 50.
The propylene / ethylene block copolymer contains not more than 50% by weight of xylene-soluble components (or normal heptane extractables) in xylene extraction (or normal heptane extraction) at 20 ° C. Wherein the residual ratio of the poly (ethylene-co-propylene) segment is 50% by weight or more. A third aspect of the present invention provides the propylene / ethylene block copolymer according to any one of the first to second aspects of the present invention, wherein the propylene / ethylene block copolymer has a normal heptane extraction rate of 5% by weight or less. . A fourth aspect of the present invention is any of the first and second aspects of the present invention, wherein the molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the propylene / ethylene block copolymer is 2 to 10. And a propylene / ethylene block copolymer as described in (1). A fifth aspect of the present invention is
(1) a solid catalyst component comprising titanium and halogen or titanium, magnesium and halogen, (2) an organometallic compound, and (3) an organosilicon compound R _n Si (O
R ′) _4-n (where n R and 4-n R ′ are the same or different hydrocarbon groups having 1 to 10 carbon atoms, and n is an integer of 1 to 3). In the presence of an olefin polymerization catalyst, a polypropylene segment is synthesized, and a poly (ethylene-co-propylene) segment is added to the end of the polypropylene segment to obtain the obtained polypropylene-b-
Provided is a method for producing a propylene / ethylene block copolymer, characterized in that poly (ethylene-co-propylene) is produced so that the weight average molecular weight is 500,000 or more. A sixth aspect of the present invention provides a method for synthesizing a polypropylene segment in the presence of (1) titanium and a halogen, or a solid catalyst component composed of titanium, magnesium and a halogen, and (2) an olefin polymerization catalyst composed of an organometallic compound. , (3) the organosilicon compound R _n Si (O
R ′) _4-n (where R and R ′ are the same or different and are a hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 1 to 3)
To add a poly (ethylene-co-propylene) segment to the end of the polypropylene segment to obtain the obtained polypropylene-b-poly (ethylene-co-propylene).
And a method for producing a propylene / ethylene block copolymer, characterized in that the propylene / ethylene block copolymer is produced so as to have a weight average molecular weight of 500,000 or more. A seventh aspect of the present invention provides the method for producing a propylene / ethylene block copolymer according to the fifth or sixth aspect of the present invention, wherein the extraction ratio of normal heptane is 5% by weight or less. Eighth of the invention
Is the molecular weight distribution of the propylene / ethylene block copolymer (weight average molecular weight (Mw) / number average molecular weight (M
n)) is 2 to 10;
8. A method for producing a propylene / ethylene block copolymer according to any one of items 1 to 7. The ninth aspect of the present invention is as follows.
(1) The method for producing a propylene / ethylene block copolymer according to any one of (5) to (8), wherein the solid catalyst component and (2) the organometallic compound are brought into contact in advance. A tenth aspect of the present invention is that, when (1) the solid catalyst component and (2) the organometallic compound are brought into contact in advance,
(3) A method for producing a propylene / ethylene block copolymer according to the ninth aspect of the present invention, which comprises adding an organosilicon compound. An eleventh aspect of the present invention uses a tubular continuous polymerization reactor having a polymerization zone a and a polymerization zone b downstream of the polymerization zone a.
Polymerize the polypropylene segment in 1 second to 15 minutes,
A polymerization region b is added to the end of the obtained polypropylene segment.
The method for producing a propylene / ethylene block copolymer according to any one of the fifth to tenth aspects of the present invention, wherein the poly (ethylene-co-propylene) segment is polymerized with a residence time of 0.01 seconds to 15 minutes. provide. According to a twelfth aspect of the present invention, the residence time of at least one of the polymerization region a and the polymerization region b is 0.5 seconds or more, and the total residence time of the polymerization region a and the polymerization region b is 0.9 seconds or more. A method for producing a propylene / ethylene block copolymer according to the eleventh aspect of the present invention, which is characterized in that: A thirteenth aspect of the present invention provides the method for producing a propylene / ethylene block copolymer according to the eleventh aspect of the present invention, wherein the reaction in the tubular continuous polymerization reactor is performed in a plug flow manner. A fourteenth aspect of the present invention is the fifth to thirteenth aspects of the invention, wherein the molar ratio of the organometallic compound to titanium in the olefin polymerization catalyst is 1 to 10.
And a method for producing a propylene / ethylene block copolymer according to (1). According to the present invention, there is provided a polypropylene-b-poly (ethylene-co-propylene) in which a polypropylene segment and a poly (ethylene-co-propylene) segment are chemically bonded, and the weight average molecular weight is 50%.
Propylene / ethylene block copolymer having a normal heptane extraction rate of 5% by weight or less can be produced by further changing the molecular weight distribution of the propylene / ethylene block copolymer to about 2 to 10 to obtain mechanical properties, especially impact resistance, heat Physical properties,
Various problems such as transparency, especially difficulty in whitening, and fluidity during molding are improved, and a material having excellent properties is efficiently provided.

[0008]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, polypropylene-b-
In the propylene / ethylene block copolymer represented by poly (ethylene-co-propylene), a polypropylene portion (a portion represented by polypropylene-) is referred to as a polypropylene segment, and a copolymer portion (-poly (ethylene-co-propylene) is shown). Is referred to as a poly (ethylene-co-propylene) segment, a propylene homopolymer is referred to as polypropylene, and an ethylene-propylene copolymer is referred to as poly (ethylene-co-propylene). In the present invention, a true propylene / ethylene block copolymer in which a polypropylene segment and a poly (ethylene-co-propylene) segment are chemically bonded (covalently bonded) is referred to as polypropylene-b-poly (ethylene-co-propylene), To the extent that the terms are not confused, they are simply referred to as block copolymers. Also, the produced propylene / ethylene block copolymer refers to the entire resulting polymer including polypropylene-b-poly (ethylene-co-propylene).

The poly (ethylene-co-propylene) segment may be a random copolymer or a block copolymer, or a mixture of both. The polypropylene-b-poly (ethylene-co-propylene) obtained in the present invention has excellent mechanical properties, especially excellent impact resistance, thermal properties,
Excellent in transparency, especially in whitening resistance, molding materials such as injection molding, compression molding, vacuum molding, blow molding, extrusion molding, film / sheet molding, etc. of crystalline polyolefin and amorphous or other crystalline polyolefin It is useful as a compatibilizer, especially as a compatibilizer between polypropylene and polyethylene, or as a modifier for polyolefins such as polypropylene or polyethylene. In this case, the structure of the polypropylene segment is preferably one having a high degree of crystalline isotacticity, but is not necessarily limited to this. Further, in the present invention, when synthesizing a block copolymer, polypropylene and / or poly (ethylene-co-propylene) can coexist by controlling polymerization conditions. In the present invention, the length and ratio of each of the polypropylene segment and the poly (ethylene-co-propylene) segment, the ethylene content in the poly (ethylene-co-propylene) segment, and the like are within a certain range of desired physical property values. A range can be selected.

In the present invention, as a catalyst for producing polypropylene-b-poly (ethylene-co-propylene), (1)
Titanium and halogen or a solid catalyst component comprising titanium, magnesium and halogen, (2) an organometallic compound, and (3) an organosilicon compound R _n Si (OR ′)
_An olefin polymerization catalyst comprising _4-n (where n R and 4-n R 'are the same or different hydrocarbon groups having 1 to 10 carbon atoms, and n is an integer of 1 to 3). Use
As the solid catalyst component (1), for example, various catalysts such as a catalyst in which titanium tetrachloride is supported on magnesium chloride and a titanium trichloride catalyst can be used. As the organometallic compound (2), various alkylaluminums can be used, for example, trialkylaluminums such as triethylaluminum and triisobutylaluminum; alkyls such as diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dihalide and diisobutylaluminum halide Aluminum halide and the like can be mentioned.

An electron-donating compound or zirconium, hafnium, cobalt, nickel, vanadium or a compound thereof can be added to the solid catalyst component and the organometallic compound.

As the electron donating compound (donor), an organosilicon compound (3) is preferable. Organosilicon compound
As (3), R _n Si (OR ′) _4-n (where n R
And 4-n R ′ are the same or different and have 1 to 10 carbon atoms.
And n is an integer of 1 to 3. ) Can be used. As the electron donating compound (donor),
In addition, ethers, esters and the like can be added.

In the organosilicon compound (3) represented by the above general formula, the substituent R is a methyl group, an ethyl group, a vinyl group, an n-propyl group, an iso-propyl group,
Allyl group, n-butyl group, iso-butyl group, sec-
Butyl group, various pentyl groups, cyclopentyl group, various hexyl groups, cyclohexyl group, phenyl group, various substituted phenyl groups, various heptyl groups, cycloheptyl groups, various octyl groups, cyclooctyl groups, various nonyl groups, cyclononyl groups, various decyl Group, cyclodecyl group and the like. As the substituent OR ′, methoxy, ethoxy, vinyloxy, n-propoxy, iso-propoxy, allyloxy, n-butoxy, iso-butoxy, sec-butoxy, various pentoxy, cyclopentoxy Groups, various hexyloxy groups, cyclohexyloxy groups, phenyloxy groups, various substituted phenyloxy groups, various heptoxy groups, cycloheptoxy groups, various octoxy groups, cyclooctoxy groups, various nonyloxy groups,
Examples include a cyclononyloxy group, various decyloxy groups, and a cyclodecyloxy group. More specifically, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, dinormalpropyldimethoxysilane, diisobutyldimethoxysilane, dinormalbutyldimethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane Examples include silane, cyclohexylmethyldimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, butyltrimethoxysilane, and the like.

<Pretreatment Method> The solid catalyst component (1) and the organometallic compound (2) may or may not be subjected to a contact treatment in advance. In the present invention, it is preferable that the solid catalyst component and the organometallic compound are brought into contact with each other before use in polymerization. The solid catalyst component and the organometallic compound have a molar ratio (referred to as Al / Ti ratio) of Ti in the solid catalyst component to Al in the alkyl aluminum which is the organometallic compound is 0.1.
~ 200, preferably 1 ~ 50, more preferably 1 ~ 1
It is used to be 10, and more preferably 2 to 5, particularly preferably about 3. It is preferable that the entire amount of the solid catalyst component is contact-treated with a part or the entire amount of the organometallic compound used as the cocatalyst. When a part of the organic metal is added at the time of the contact treatment, the remainder is added to the polymerization reaction system alone or mixed with the raw material monomers. When the solid catalyst component (1) and the organometallic compound (2) are subjected to contact treatment in advance, the Al / Ti ratio is 0.1 to 200 as described above,
Preferably, they are mixed and contacted so as to be 1 to 50, more preferably 1 to 10, still more preferably 2 to 5, and particularly preferably about 3. The contact between the solid catalyst component and the organometallic compound may be performed by mixing the solid catalyst component and a liquid organometallic compound, but preferably, at least one of the solid catalyst component and the organometallic compound is a polymerization inert solvent. Is used to prepare a suspension solution or a homogeneous solution, and the two can be mixed together. As the polymerization inactive solvent, a polymerization solvent described below can be used. For mixing, a mixing tank equipped with a stirrer, a line mixer, a vibration type stirrer, an ultrasonic stirrer, a pulverizer and the like can be used. As the contact treatment conditions, the temperature is 0 to 100 ° C, preferably 5 to 7 ° C.
0 ° C, time is 0.05 seconds to 48 hours, preferably 0.3 seconds
For seconds to 24 hours, the pressure may be reduced pressure, normal pressure or increased pressure,
There is no particular limitation. The contact atmosphere is not particularly limited as long as the catalyst does not deactivate the catalyst. For example, the atmosphere is preferably an inert gas atmosphere such as dry high-purity nitrogen.

The organosilicon compound (3), which is an electron donating compound, comprises a solid catalyst component (1) and an organometallic compound (2).
When the contact treatment is performed in advance, the solid catalyst component (1) may be added at the time of contact, or may be added without adding at the time of contact.
It may be added to the organometallic compound (2) and / or ethylene, propylene, an ethylene-propylene mixed raw material, or the like. When the contact treatment is not performed in advance, the solid catalyst component (1), the organometallic compound (2), or a mixed material of ethylene, propylene, and ethylene-propylene (a mixture of unreacted propylene and ethylene with ethylene alone instead of the mixed material) Is formed in the reactor.). Using the catalyst thus obtained, a polypropylene segment and a poly (ethylene-co-propylene)
The segments are polymerized.

The amount of the electron donating compound added to the catalyst is, for example, the molar ratio of the electron donating compound / Ti of 0.05 to 20.
0, but within this range, the poly (ethylene-co-propylene) can be added even if the electron-donating compound is added in its entirety during the contact treatment or dividedly added to other components.
It may be added at the time of segment polymerization. That is, the weight of the organosilicon compound added during the pre-treatment and / or polymerization is 0.05 to 2 in terms of the molar ratio of Si in the organosilicon compound to Ti contained in the solid catalyst component (Si / Ti).
00, preferably 0.5 to 100. The ratio of the electron-donating compound / Ti should be exactly a mole / gram atomic ratio, but is called a molar ratio for convenience. The Al / Ti ratio, the Si / Ti ratio, and the like should also be referred to as the gram atomic ratio, but are referred to as the molar ratio for convenience.

The organosilicon compound (3) may not be added when the polypropylene segment is polymerized, but may be added when the poly (ethylene-co-propylene) segment is polymerized. In this case, the solid catalyst component (1) and the organometallic compound (2) may or may not be subjected to contact treatment in advance. Further, the solid catalyst component (1)
And after polymerizing the polypropylene segment in the presence of a part of the organometallic compound (2) and the organosilicon compound (3),
The remaining organosilicon compound (3) can be added when the poly (ethylene-co-propylene) segment is combined and polymerized. The polypropylene segment can be polymerized in the presence of the solid catalyst component (1), the organometallic compound (2), and the organosilicon compound (3). Further, the organosilicon compound (3) may be a mixture, and a different type from the case where the polypropylene segment is polymerized and the case where the poly (ethylene-co-propylene) segment is polymerized may be used.

<Polymerization method> An example of the polymerization method of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of the polymerization method. In FIG. 1, A, B, C, and D are containers, and a,
b shows the polymerization zone of the tubular continuous polymerization reactor. The tube-type continuous polymerization reactor may be any as long as the reaction raw materials are supplied, the reaction is performed, and the reaction mass is discharged out of the reactor within the residence time described below. The diameter ratio and the like are not particularly limited. The reaction in the tubular continuous polymerization reactor is preferably of a plug flow type, and a reaction is carried out within the residence time, and a baffle or the like is provided in the reaction tube within a range where the reaction mass is discharged out of the reactor. It is possible to improve the stirring effect by means of the present invention, and the present invention includes these forms in the expression of plug flow. Container A contains a solid catalyst component,
An organic metal, ie, an aluminum alkyl, or a catalyst component, an organosilicon compound, and a solvent which have been subjected to a contact treatment thereof in advance are charged. In the container B, alkyl aluminum and a solvent are put to dissolve propylene, and an organosilicon compound can be added if necessary. Here, the amount of the alkyl aluminum is not particularly limited, but the Al / Ti molar ratio to the Ti in the container A is 1 to 1,000.
Times, sometimes 30 to 500 times. Note that the molar ratio (Al / Ti ratio) of Ti in the container A and the total Al in the containers A and B is 0.1 to 20 as described above.
0, preferably 1 to 50, more preferably 1 to 10,
Further, it is more preferably used so as to have 2 to 5, particularly preferably about 3. A solvent is put in the container C to dissolve ethylene or a mixture of ethylene and propylene, and an organosilicon compound can be added as necessary. In particular, the organosilicon compound can be added only when polymerizing the copolymer segment.

In the first stage, the effluent of container A and container B
And polymerizes the polypropylene segment. The polymerization region is indicated by a. Subsequently, the effluent of the container C is introduced into the polymerization region b. In the polymerization region b, a poly (ethylene-co-propylene) segment chemically bonded to the terminal of the polypropylene segment synthesized in the polymerization region a is generated. The effluent from the polymerization area b is led to a container D containing alcohol, and the polymerization is stopped. Thereafter, the solvent, alcohol and the like are separated from the reaction mass, and the obtained solid block copolymer is washed and dried to obtain the desired polypropylene-b-poly (ethylene-c
o-propylene). The composition of the block copolymer is determined by the length of the polymerization region a or the polymerization region b and the flow rate of the effluent (that is, the polymerization reaction time), the amount of propylene dissolved in the container B and / or the amount of ethylene or a mixture of ethylene and propylene dissolved in the container C. Can be controlled by changing In addition, the polypropylene segment is polymerized, followed by poly (ethylene-co-
When the (propylene) segments are polymerized, the block chain length of each segment can be changed by changing the polymerization time of each segment. Further, a vessel C ′ (not shown) containing a hydrocarbon solvent such as toluene is provided between the vessel D and the downstream of the polymerization area b,
Separating the remaining propylene and / or ethylene monomer from the reaction mass while maintaining the catalytic activity of the polymer,
A polymerization zone c (not shown) was newly provided downstream of the vessel D, and the obtained raw polypropylene-b-poly (ethylene-c
At the end of (o-propylene), a polypropylene segment can be further polymerized, or a poly (ethylene-co-propylene) segment can be polymerized following the polypropylene segment. Alternatively, poly (ethylene-c) having a further different composition is added to the terminal of the obtained raw polypropylene-b-poly (ethylene-co-propylene).
o-propylene) segment. As described above, the homopolymer polymerization step and the copolymer polymerization step can be repeated twice or more, and the polymerization time at the time of repetition is long (about 1 to 2 hours).
It is also possible to change the copolymer composition.

The solvent (polymerization solvent) is not particularly limited, but hydrocarbons such as toluene, xylene, hexane and heptane, and low-boiling hydrocarbons such as liquefied propylene, liquefied propane and liquefied isobutane are used, but are not particularly limited. Not something. In the present invention, gas phase polymerization can be performed without using a solvent. Also, polypropylene-b-
Polymerization temperature of poly (ethylene-co-propylene) is -20
C. to 200 C., preferably 0 to 70 C., and the polymerization pressure is 1 to 40 atm, preferably 3 to 30 atm.
The polymerization time is from 0.02 seconds to 30 minutes, preferably from 0.3 seconds to
Although it is 2 minutes, it is not particularly limited. When the above is further considered for each region where each segment is polymerized, the residence time for polymerization is 0.01 second to 15 seconds in the region where the polypropylene segment is polymerized (a in FIG. 1).
Minutes, preferably 0.15 seconds to 2.5 minutes, and in the region where the poly (ethylene-co-propylene) segment is polymerized (b in FIG. 1), the residence time for polymerization is 0.1 minute.
The time is from 01 second to 15 minutes, preferably from 0.15 second to 2.5 minutes. In the present invention, the residence time of at least one of the polymerization zone a and the polymerization zone b is 0.5 second or longer, and the total polymerization time of the polymerization zone a and the polymerization zone b is 0.9 second or longer.

The present inventors have disclosed that true polypropylene-b-poly (ethylene-co-propylene) having a chemical bond between a polypropylene segment and a poly (ethylene-co-propylene) segment has been formed. The extraction was performed by extracting various polymers obtained using the normal heptane room temperature extraction method described in JP-A-8-92338. That is, the extraction ratio of the polypropylene-b-poly (ethylene-co-propylene) obtained in the present invention, the polypropylene obtained by polymerizing the effluents from containers A and B only in polymerization region a, and the container The effluents from A and C were polymerized only in the polymerization region b and confirmed by comparing the extraction ratio of a mixture with poly (ethylene-co-propylene) obtained.

The polypropylene-b- obtained according to the present invention
Poly (ethylene-co-propylene) has a weight-average molecular weight of 500,000 to 2,000,000 and can be obtained with high precision of 600,000 or more, further 700,000 or more, and further 1,000,000 or more, 1.4 million. As described above, a true propylene / ethylene block copolymer having a high molecular weight is characterized by mechanical properties such as heat resistance and tensile strength rigidity as compared with those having a molecular weight of less than 500,000. Further, the polypropylene-b-poly (ethylene-co-propylene) obtained by the present invention is:
The molecular weight distribution is adjusted with high precision in a wide range such as 2 to 10, more preferably 3 or more, or even 4 or more, further 8 or less, or even 6 or less. As described above, since the molecular weight distribution can be controlled over a wide range, the fluidity can be controlled in accordance with various molding methods. Also, the polypropylene-b-poly (ethylene-co-propylene) obtained by the present invention
Can be obtained with a normal heptane extraction rate of 0.2 to 5% by weight, 4% by weight or less, further 3% by weight or less, further 1% by weight or less, about 0.3% by weight.
As described above, the true block copolymer having a low normal heptane extraction rate can be stably operated without causing adhesion to the polymerization tube wall and clogging of the pipe as compared with those having a normal heptane extraction rate higher than 5% by weight. The polypropylene-b-poly (ethylene-co-propylene) obtained according to the present invention has a copolymer content of 40 to 99% by weight, 50% by weight or more, further 60% by weight or more, and further 70% by weight or more, In particular, those of 80% by weight or more and 97% by weight can be obtained with high accuracy. As described above, since the copolymer content can be controlled in a wide range, the design range of rigidity, impact resistance, and tensile strength can be widened, and a desired propylene / ethylene block copolymer can be easily obtained. Also, the polypropylene-b-poly (ethylene-co-propylene) obtained by the present invention
Means that the ethylene content in the copolymer part is from 40 to 90% by weight, more preferably from 50 to 80% by weight, or even from 60 to 7% by weight.
The one with 0% by weight can be obtained with high accuracy. As described above, since the ethylene content can be controlled in a wide range, rigidity, impact resistance,
The design range of the tensile strength can be widened, and a desired propylene / ethylene block copolymer can be easily obtained. In the tensile test, the propylene / ethylene block copolymer of the present invention has a Young's modulus (tensile elastic modulus) of 45 to 1,250 MPa, a yield strength of 5 to 40 MPa, and a maximum point (strength at a breaking point) of 5 MPa or more. ~ 570% (160mm)
Integrated value up to. ): 1.5 KN · mm or more In the dynamic viscoelasticity test, the storage elastic modulus E ′ value at 150 ° C .: (1 to 30) × 10 ⁷ Measurement end temperature (considered as the limit temperature at which the sample keeps its shape above the melting point. ): 170 to 200 ° C. The propylene / ethylene block copolymer of the present invention
It is characterized in terms of viscosity, melt viscosity, melt tension, impact strength, elongation, elongation at break, elastic modulus, hardness and the like. A propylene / ethylene block copolymer having a physical property described above, which is a true block copolymer in which a polypropylene segment and a poly (ethylene-co-propylene) segment are chemically bonded, has not been known so far.

[0023]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. The evaluation method used in the examples and comparative examples was based on the following method. (1) Weight average molecular weight (Mw), molecular weight distribution (Mw / M
n): A sample was dissolved in ortho-dichlorobenzene at 135 ° C., and a GPC device (SSC7100 manufactured by Senshu Chemical Co., Ltd.)
It measured using. The molecular weight distribution (Mw / Mn) was obtained from the weight average molecular weight (Mw) and the number average molecular weight (Mn) by an ordinary method. (2) Ethylene content (% by weight): Infrared absorption (IR) spectroscopy and nucleation using copolymers of various polymerization types with known ethylene contents and samples of various mixing ratios of polypropylene and polyethylene. A number of calibration curves are prepared for each polymerization type and ethylene content by magnetic resonance (NMR) spectroscopy, and the appropriate one of the above calibration curves is used. Alternatively, the ethylene content was measured by the linear absorbance. The ethylene content (EL: wt%) of the copolymer part is calculated by the following equation. EL (% by weight) = Total ethylene content (% by weight) × 100 / CO content (In the above formula, the CO content (% by weight) is the polymerization amount of the copolymer part × 10
0 / (polymerization amount of polypropylene part + polymerization amount of copolymer part). The poly (ethylene-co-propylene) segment content (CO content) is defined as the latent heat of fusion of the polypropylene segment per unit weight of the sample, and the latent heat of fusion of only isotactic polypropylene (113 J / g). It is also obtained by comparison. However, since the calibration curve differs depending on the total ethylene content and the type of polymer, a large number of calibration curves are prepared for each range of the total ethylene content and for each type of polymerization, as in the above measurement of the total ethylene content. In some cases, the sample may be separated by a solvent, and the amount of the extract and the residue may be measured and determined. The method for measuring the latent heat of fusion of the polypropylene segment is as follows. Apparatus: DSC (Perkin Elmer DSC-7 type) The temperature was raised to 200 ° C. at a rate of 10 ° C./min, held for 10 minutes, and then lowered to −100 ° C. at a rate of 10 ° C./min.
After holding for 10 minutes to make the heat history constant, the temperature was raised to 200 ° C. at a rate of 10 ° C./min to obtain a melting curve.
The peak up to 5 ° C. was defined as the latent heat of fusion of the polypropylene segment. (3) Normal heptane extraction amount (% by weight): 0.1 g sample in a 1 liter beaker, 200 ml of normal heptane
After stirring at room temperature for 5 hours, the mixture was filtered through a Teflon membrane filter, and the residue was dried under reduced pressure at 70 ° C. for 12 hours and weighed to determine the amount of extraction. Further, the copolymer content and the ethylene content (meaning the ethylene content in the copolymer part), the weight average molecular weight, and the molecular weight distribution of the extraction residue are measured. (4) Tensile test Press sheet molding Melting, pressurizing conditions: 200 ° C, 5MPa Cooling, pressurizing conditions: 18 ° C, 5MPa Sheet thickness: 0.2mm Test piece: dumbbell-shaped Tensile tester: manufactured by Toyo Seiki Seisaku-sho, Ltd. Strograph V1
0 Tensile strength and elongation: Measured at a test temperature of 23 ± 1 ° C. and a tensile speed of 50 mm in accordance with JIS K6758. (5) Tensile whitening: In the tensile test, the degree of whitening of the test piece at the time of 300% tension was visually evaluated. Evaluation results ：: no whitening, Δ: slight whitening, ×: extremely whitening. (6) Tan δ and E ′ Measured by temperature dependence of dynamic viscoelasticity. Apparatus: DVE-V4-FT manufactured by Rheology Co., Ltd. Sample preparation: Press sheet (melted at 200 ° C., cooled at 18 ° C.) Sample size: width 5 mm, thickness 0.2 mm Measurement frequency: 10 Hz Measurement mode: tensile strain: 0.05 % Heating rate: 3 ° C / min About the reaction vessel Vessel A is made of stainless steel with a capacity of 3 liters, water is made of stainless steel with a capacity of 3 liters, and vessel C is made of stainless steel with a capacity of 3 liters. , Container D has a capacity of 1
It is made of stainless steel with a 0 liter water jacket.

[Example 1] (contact of the solid catalyst and the organic metal in the presence of an external donor in advance) <Preliminary treatment> In a container A, 1 liter of toluene and 2 mol / liter of triethylaluminum in a toluene solution 30 m
1 (manufactured by Tosoh Akzo Co., Ltd.) and 3.5 g (0.02) of diisopropyldimethoxysilane as an organosilicon compound.
mo1) (manufactured by Chisso Corporation), a titanium-supported chlorine-containing magnesium catalyst (abbreviated as Ti-supported Mg catalyst) 35
g (“THC-C catalyst” manufactured by Toho Titanium Co., Ltd .; the same applies hereinafter)), and mixed and contacted in advance at 30 ° C. for 3 minutes. At this time, the Al / Ti molar ratio is 3, and the Si / Ti molar ratio is 1. <Polymerization> Container B contains 0.8 liter of toluene and 180 g (4.3 mol) of propylene, and container C contains 1 liter of toluene and 17 g (0.6 mol) of ethylene. The temperature was kept at 30 ° C. The container D contained 3 liters of isopropyl alcohol, and the temperature was kept at 15 ° C. Further, the temperature of the polymerization regions a and b was maintained at 25 ° C., and the polymerization region a (tube length 1)
The residence time of the reaction mass at 0.6 cm and a polymerization zone b (tube length 50 cm, tube inner diameter 10
mm), the containers A to C were pressurized with nitrogen so that the residence time of the reaction mass in
The polymerization was terminated when 20 to 25 g of the catalyst was discharged. After the polymerization is completed, the product is taken out of the container D, and 35%
After adding hydrochloric acid solution (10 ml) and stirring for 24 hours, the resulting polymer was filtered and washed three times with 1 liter of isopropyl alcohol and three times with 1 liter of ion-exchanged water.
The mixture was filtered and dried under reduced pressure at 60 ° C. for 8 hours to obtain 27.6 g of the desired block copolymer powder. At this time, the copolymer content was 47.6 wt%, and the ethylene content in the copolymer was 51.0 wt%. The weight average molecular weight of the obtained block copolymer is 543,000, the molecular weight distribution is 7.6, and the normal heptane extraction rate is 2.8 wt%.
Met. In addition, the weight average molecular weight of the normal heptane extraction residue was 643,000, the molecular weight distribution was 5.0, the copolymer content was 43.8 wt%, and the ethylene content in the copolymer was 53.3 wt%. Thus, in the propylene / ethylene block copolymer of the present invention, about 90% by weight of the copolymer segment remains in the normal heptane extraction residue, and 96% by weight of ethylene remains, and the polypropylene segment and the poly (ethylene- c
It can be seen that true polypropylene-b-poly (ethylene-co-propylene) with chemically bonded (o-propylene) segments was obtained.

[Example 2] <Preliminary treatment> The same procedure as in Example 1 was performed. <Polymerization> Container B contains 0.8 liter of toluene and 180 g (4.3 mol) of propylene, and container C contains 1 liter of toluene and 28 g (1.0 mol) of ethylene. The temperature was kept at 30 ° C. The container D contained 3 liters of isopropyl alcohol, and the temperature was kept at 15 ° C. Further, the temperature of the polymerization regions a and b is kept at 25 ° C., and the polymerization region a (tube length 5)
0 cm, inner diameter of the tube 8 mm), the residence time of the reaction mass was 0.41 second, the polymerization region b (tube length 100 cm, inner tube diameter 10).
mm), the reactors A to C were pressurized with nitrogen so that the residence time of the reaction mass in
The polymerization was terminated when 20 to 25 g of the catalyst was discharged. After completion of the polymerization, the same operation as in Example 1 was performed to obtain 32.9 g of a target block copolymer powder.
At this time, the copolymer content was 90.2 wt%, and the ethylene content in the copolymer was 66.5 wt%. The weight average molecular weight of the obtained block copolymer is 555,00
0, the molecular weight distribution was 5.2, and the normal heptane extraction rate was 3.7 wt%. In addition, the weight average molecular weight of the normal heptane extraction residue was 622,000, the molecular weight distribution was 4.8, the copolymer content was 86.2 wt%, and the ethylene content in the copolymer was 71.7 wt%, and it was a true block copolymer. . A molded test piece was produced using the obtained block copolymer, and the physical properties were evaluated. In the tensile test, the Young's modulus (tensile elastic modulus) was 66 MPa, the yield strength was 5.2 MPa, and the maximum point (strength at break) was 16.1.
MPa, elongation at break of 570% or more, total energy (integration value from 0 to 570% (160 mm) in elongation)
2.3KN · mm, 150 ° C in dynamic viscoelasticity test
Is 3.5 × 10 ⁷ , and the measurement end temperature (which is considered to be the temperature at which the sample keeps its shape above the melting point) is 183 ° C. and all have a molecular weight of less than 500,000. Better.

Examples 3 to 9: Addition amount of diisopropyldimethoxysilane, Si / Ti molar ratio, polymerization regions a and b
The operations were carried out in the same manner as in Example 2 except that the respective residence times of the reaction mass in Example 1 were set to the values shown in Examples in Tables 1 and 2. The results are shown in Tables 1 and 2.

[Examples 10 to 11] When the contact temperature in vessel A was set at 50 ° C. and the temperatures of vessels B and C were set at 45 ° C., the residence time of the reaction mass in polymerization zone a and the residence time of the reaction mass in polymerization zone b were determined. Example 2 except as shown in Table 2.
The same operation as described above was performed. Table 2 shows the results.

Example 12 The polymerization temperature of the reaction mass in the polymerization zone a was 25 ° C. and the residence time was 0.52 seconds. The polymerization temperature of the reaction mass in the polymerization zone b was 25 ° C. and the residence time was 0.98 seconds. The same operation as in Example 2 was performed except that the operation was performed. The yield of the obtained block copolymer was 4.2 g. At this time, the copolymer content was 91.6 wt%, and the ethylene content in the copolymer was 80.4 wt%.
The weight average molecular weight of the obtained block copolymer is 1,4.
05,000, molecular weight distribution was 5.0. Normal heptane extraction rate was 0.3 wt%. The weight average molecular weight of the normal heptane extraction residue was 1,410,0.
00, molecular weight distribution 4.0, copolymer content 89.5
wt%, ethylene content in the copolymer is 82.3 wt%
Which is a true block copolymer. A molded test piece was produced using the obtained block copolymer, and the physical properties were evaluated. In the tensile test, the Young's modulus was 84 MPa, the yield strength was 6.2 MPa, the maximum point was 26.0 MPa, and the elongation at break was 5
70% or more, the total energy is 3.0 KN · mm, the storage elastic modulus E ′ at 150 ° C. is 3.1 × 10 ⁷ in the dynamic viscoelasticity test, and the measurement end temperature is 190
° C, which are significantly better than those having a molecular weight of less than 500,000.

Example 13 Example 13 was repeated except that the addition amount of diisopropyldimethoxysilane, the molar ratio of Si / Ti, and the respective residence times of the reaction mass in the polymerization regions a and b were as shown in Example 13 in Table 2. The same operation as in Example 2 was performed. Table 2 shows the results.

[Comparative Examples 1 to 3] Triethylaluminum was further added to Container B with respect to the above Examples (Comparative Examples 1 and 2).
Mainly, each residence time of the reaction mass in the polymerization regions a and b is 0.5 seconds or less and the total residence time is shortened to 0.63 seconds (Comparative Example 3), mainly the addition amount of diisopropyldimethoxysilane, Si / The same operation as in Example 2 was performed except that the Ti molar ratio and each residence time of the reaction mass were set to the values shown in Comparative Examples in Table 2. Table 2 shows the results. Comparative Example 1 is a true block copolymer, but has a weight average molecular weight of 280,000, and has a Young's modulus of 6 in a tensile test.
1MPa, yield strength 4.5MPa, maximum point 14.2MP
a, elongation at break of 570% or more, total energy of 1.9
KN · mm, and in the dynamic viscoelasticity test, the storage elastic modulus E ′ at 150 ° C. was 1.0 × 10 ⁷ , and the measurement end temperature was 165 ° C., which was inferior to those having a molecular weight of 500,000 or more. I have. Comparative Example 2 is a true block copolymer, but has a weight average molecular weight of 330,000, and a dynamic viscoelasticity test with a storage modulus E ′ at 150 ° C. of 0.
A 7 × 10 ^7, the measurement end temperature 165 ° C. and a molecular weight is significantly different from those of 500,000 or more. Comparative Example 3 was a true block copolymer but had a weight average molecular weight of 300,
In the dynamic viscoelasticity test, the storage modulus E ′ at 150 ° C. was 2.2 × 10 ⁷ , and the measurement end temperature was 174 ° C., which was inferior to those having a molecular weight of 500,000 or more. .

Reference Example 1 (No External Donor Used, Pre-Contact) The following test was conducted for reference. <Preliminary treatment> In a container A, 1 liter of toluene, 35 g of a Ti-supported Mg catalyst (manufactured by Toho Titanium Co., Ltd.), and a 2 mol / liter toluene solution of triethylaluminum 3
0 ml (60 mmol) (manufactured by Tosoh Akzo Co., Ltd.) and rotated at 750 rpm using a stirrer.
Premixed contact was made at 3 ° C. for 3 minutes. Al / T at this time
The i molar ratio is 3. <Polymerization> In the container B, 200 ml of toluene and 240 m of a 2 mol / liter toluene solution of triethylaluminum were used.
l (480 mmol) and 300 g of propylene (7.
1 mol), and 900 ml of toluene is placed in container C,
15 g (0.5 mol) of ethylene and 35 of propylene
g (0.8 mol), and the temperature of containers B and C was 3
It was kept at 0 ° C. The container D contained 5 liters of isopropyl alcohol, and the temperature was kept at 15 ° C. Further, the temperature of the polymerization regions a and b was kept at 25 ° C., and the pressure of the containers A to C was increased with nitrogen so that the residence time of the reaction mass in each region was 0.3 seconds, and polymerization was carried out.
The polymerization was terminated when 20 g to 25 g of the catalyst was discharged. After the polymerization is completed, the reaction mass is extracted from the container D, and 3
After adding 100 ml of 5% hydrochloric acid solution and stirring for 24 hours,
The resulting polymer was filtered, washed three times with 1 liter of isopropyl alcohol and then three times with 1 liter of ion-exchanged water, filtered, and dried under reduced pressure at 60 ° C. for 8 hours to obtain 19.5 g of the powder of the target block copolymer. Obtained. At this time, the copolymer content was 64.1 wt%, and the ethylene content was 33.5 wt%. The catalyst activity per second of the obtained block copolymer was 1.5 g / g-catalyst, and the extraction ratio of normal heptane was 23 wt%. Although a part of the polymer was extracted, it was compared with the mixture as a blank described below. Most of the polymer remains. The extracted component was poly (ethylene-co-propylene). Further, the residual inorganic substance in the obtained block polymer powder was 90 ppm by weight. On the other hand, a blank mixture (polypropylene (propylene in container B was replaced with a)
Polymerized only in the polymerization zone)
%, And poly (ethylene-co-propylene) (container C
A mixture obtained by polymerizing a mixture of ethylene and propylene in only the b polymerization region) and a mixture of 60 wt%) had a normal heptane extraction rate of 57 wt%, and almost poly (ethylene-co-propylene) was extracted. Only remain, indicating that the two are hardly chemically bonded. The results of the above Examples, Comparative Examples and Reference Examples are shown in Tables 1 to 3. Notes for each table are as follows. A, B, C, D: vessels a, b: reaction zone Tol: toluene EL: ethylene PL: propylene EL content: ethylene content co content: copolymer content External donor * 1): diisopropyldimethoxysilane extraction rate * 2): n -Heptane

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

According to the present invention, a compatibilizer of crystalline polyolefin and amorphous polyolefin, especially a compatibilizer of polypropylene and polyethylene, excellent in rigidity, impact resistance, tensile properties and heat resistance, injection molding, compression Polypropylene-b-poly (ethylene-co-propylene) useful as a molding material such as molding, vacuum molding, blow molding, extrusion molding, film / sheet molding, and a spinning material can be efficiently produced. Therefore, the obtained product is less likely to deteriorate in quality due to recycling, and when molded, a good molded product such as a film having a smooth surface and little fish eyes can be obtained.

[Brief description of the drawings] [Explanation of symbols]

FIG. 1 is a flow sheet showing the polymerization method of the present invention.

FIG. 2 is a view showing the measurement results of dynamic viscoelasticity of a propylene / ethylene block copolymer obtained in Example 2.

FIG. 3 is a view showing the measurement results of dynamic viscoelasticity of the propylene / ethylene block copolymer obtained in Example 12.

FIG. 4 is a view showing the measurement results of dynamic viscoelasticity of the propylene / ethylene block copolymer obtained in Comparative Example 1.

FIG. 5 is a view showing the measurement results of dynamic viscoelasticity of the propylene / ethylene block copolymer obtained in Comparative Example 2.

FIG. 6 is a view showing the measurement results of dynamic viscoelasticity of the propylene / ethylene block copolymer obtained in Comparative Example 3.

[Explanation of symbols]

 A, B, C, D containers a, b Polymerization area

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Minoru Terano 1-50 Asahidai, Tatsunokuchi-cho, Nomi-gun, Ishikawa Pref. A-35 (72) Inventor Tetsuya Matsukawa 10-2, Oibowecho, Kanazawa-ku, Yokohama-shi, Kanagawa-ken (72) ) Inventor Hideji Satake 10-2, Otobocho, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Masato Takahashi 4-30-201, Tauracho, Yokosuka-shi, Kanagawa Prefecture AA02A AB01A AC05A AC15A AC16A BA00A BA01A BA01B BA02B BB00A BB01B BC15B BC16B BC17B BC19B BC34B CA16A EA02 EB04 EC01 ED01 ED02 EF01 FA01 FA02 FA04 GA01 GA06 GA21

Claims (14)

[Claims] 1. Polypropylene-b-poly (ethylene-co-propylene) having the following features (a) and (b):
A propylene / ethylene block copolymer comprising: a propylene / ethylene block copolymer having a weight average molecular weight (Mw) of 500,000 or more. (A) Polypropylene segment and poly (ethylene-c
o-propylene) segment. (B) A polypropylene segment and a poly (ethylene-co-propylene) segment are synthesized in the presence of titanium and a halogen or a solid catalyst component composed of titanium, magnesium and a halogen and an olefin polymerization catalyst composed of an organometallic compound. 2. Polypropylene-b-poly (ethylene-
(co-propylene), wherein the weight average molecular weight (Mw) of the propylene / ethylene block copolymer is 500,
The propylene / ethylene block copolymer contains 50% by weight or less of a xylene-soluble component (or a normal heptane extract) in 20 ° C. xylene extraction (or a normal heptane extract). A propylene / ethylene block copolymer having a residual ratio of (ethylene-co-propylene) segments of 50% by weight or more. 3. The propylene / ethylene block copolymer according to claim 1, wherein the propylene / ethylene block copolymer has a normal heptane extraction rate of 5% by weight or less. 4. The propylene / ethylene block copolymer according to claim 1, wherein the molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) is 2 to 10. Propylene / ethylene block copolymer. 5. A solid catalyst component comprising (1) titanium and halogen or titanium, magnesium and halogen, (2) an organometallic compound, and (3) an organosilicon compound R _n Si (OR ′) _4-n ( Where n R and 4-n
R ′ are the same or different hydrocarbon groups having 1 to 10 carbon atoms, and n is an integer of 1 to 3. ), A polypropylene segment is synthesized, and a poly (ethylene-co-propylene) segment is added to the end of the polypropylene segment to obtain a polypropylene-b-poly (ethylene-co-propylene). A method for producing a propylene / ethylene block copolymer, characterized in that the propylene / ethylene block copolymer is produced so as to have a weight average molecular weight of 500,000 or more. 6. After synthesizing a polypropylene segment in the presence of (1) titanium and a halogen, or a solid catalyst component comprising titanium, magnesium and a halogen, and (2) an olefin polymerization catalyst comprising an organometallic compound, 3) An organosilicon compound R _n Si (OR ′) _4-n (where R and R ′ are the same or different and are a hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 1 to 3). In addition, poly (ethylene-c
A method for producing a propylene / ethylene block copolymer, wherein an o-propylene) segment is produced so that the obtained polypropylene-b-poly (ethylene-co-propylene) has a weight average molecular weight of 500,000 or more. 7. The method for producing a propylene / ethylene block copolymer according to claim 5, wherein the extraction ratio of normal heptane is 5% by weight or less. 8. The propylene / ethylene block copolymer according to claim 5, wherein the molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) is 2 to 10. A method for producing a propylene / ethylene block copolymer. 9. The method for producing a propylene / ethylene block copolymer according to claim 5, wherein (1) the solid catalyst component and (2) the organometallic compound are brought into contact in advance. 10. The propylene / ethylene block copolymer according to claim 9, wherein (1) an organosilicon compound is added when (1) the solid catalyst component and (2) the organometallic compound are brought into contact in advance. Manufacturing method. 11. A polymerization zone a and a polymerization zone b downstream thereof.
Using a tubular continuous polymerization reactor having the following, a polypropylene segment is polymerized in a polymerization region a at a residence time of 0.01 seconds to 15 minutes, and a residence time of 0.01 in the polymerization region b is obtained at the end of the obtained polypropylene segment. Seconds to 1
The method for producing a propylene / ethylene block copolymer according to any one of claims 5 to 10, wherein the poly (ethylene-co-propylene) segment is polymerized in 5 minutes. 12. The residence time of at least one of the polymerization region a and the polymerization region b is 0.5 seconds or more, and the total residence time of the polymerization regions a and b is 0.9 seconds or more. The method for producing a propylene / ethylene block copolymer according to claim 11, wherein 13. The method for producing a propylene / ethylene block copolymer according to claim 11, wherein the reaction in the tubular continuous polymerization reactor is performed in a plug flow manner. 14. The process for producing a propylene / ethylene block copolymer according to claim 5, wherein the molar ratio of the organometallic compound to titanium in the olefin polymerization catalyst is from 1 to 10.