JPH10218930A - Production of propylene-ethylene block copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the balance between impact strength and rigidity of a propylene-ethylene block copolymer by causing a halogen compd. to be present in the step of propylene-ethylene copolymn. conducted in the presence of a catalyst comprising a solid component contg. Mg, Ti, a halogen, and an electron- donating compd., two aluminum compds. different in electronegativity from each other, and an alkoxysilane compd. SOLUTION: The solid component is prepd. by bringing a magnesium compd., a titanium compd., an electron-donating compd., and a halogen compd. into contact with each other. In one of the aluminum compds., the sum of Pauling's electronegativities of atoms bonded to one Al atom is lower than 8; and in the other, the sum is 8 or higher. The alkoxysilane compd. is represented by formula I (wherein R<1> is 1-6C alkyl or cycloalkyl; R<2> is 1-6C alkyl, alkenyl, or alkynyl; and 1<=s<=3). The halogen compds. present in the copolymn. step is represented by formula II (wherein Met is a metal atom; X is halogen; and n is the valence of Met).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a propylene-ethylene block copolymer, and more particularly to a method for producing a propylene-ethylene block copolymer having an excellent balance between impact strength and rigidity.

[0002]

2. Description of the Related Art Propylene polymerization catalysts comprising a catalyst component containing Mg, Ti, halogen and an electron donating compound as essential components, an organoaluminum compound and a silane compound are well known. It is also known that the tacticity of the resulting polypropylene can be changed by changing the silane compound (Japanese Patent Application Laid-Open No. 7-109309). Thus, the stereoregularity of polypropylene has been improved, and its rigidity has been improved.

[0003] Furthermore, polyolefins have the disadvantage of inherently low impact resistance. Therefore, methods for improving impact resistance by copolymerizing other olefins such as ethylene have been widely used. However, this method improves the impact resistance but decreases the rigidity accordingly. Therefore, a method of stepwise polymerizing while changing the polymerization ratio of propylene to another olefin. That is, various methods have been proposed to improve the balance between the rigidity and the impact resistance of the copolymer by performing multi-stage polymerization (for example, Japanese Patent Publication No. 3-4).
No. 456). It is also known that a silicon compound is present during copolymerization as another improvement method (Japanese Patent Application Laid-Open No. Hei 6-73113). However, none of these methods has obtained a polymer sufficiently excellent in balance between rigidity and physical properties of other impact properties.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to produce a propylene-ethylene block copolymer having an excellent balance between impact strength and rigidity.

[0005]

Means for Solving the Problems In view of the above problems, as a result of intensive studies, the present inventors have repeatedly studied a copolymer of propylene and ethylene. As a result, during the polymerization of propylene, magnesium, titanium, halogen, And using a specific catalyst system including a solid catalyst component having an electron donating compound as an essential component, and adding a specific halogen-containing compound during the copolymerization reaction of propylene and ethylene,
Propylene with excellent balance of rigidity and physical properties of impact resistance
The present inventors have found that an ethylene block copolymer can be obtained, and have reached the present invention.

That is, the present invention provides: (A) a solid component containing magnesium, titanium, halogen and an electron donating compound as essential components; (B-1) an electronegative poling of an atom bonded to one Al atom. (B-2) an aluminum compound having a sum of the electronegativity values of poling of atoms bonded to one Al atom of 8 or more, and (B-2) an aluminum compound having a sum of values of less than 8; C) A method for producing a propylene-ethylene block copolymer, comprising the steps of (a) polymerizing propylene in the presence of a polymerization catalyst comprising an alkylalkoxysilane compound, and (b) performing a step of copolymerizing propylene and ethylene. in the step (b), (D) the following formula: MetX _n (in the formula, Met represents a metal atom; X represents a halogen atom; n is metal Me Wherein the carried out in the presence of a representative of the valence) a halogen-containing compound represented by the.

Preferred embodiments of the present invention are described below. (A) The above method using a polymerization catalyst wherein the component (B-1) is selected from trialkylaluminum. (B) The component (B-2) is a group consisting of dialkylaluminum monochloride, alkylaluminum dichloride, alkylaluminum sesquichloride, dialkylaluminum monoalkoxide, alkylaluminum dialkoxide, alkylaluminoxane, alkylaluminum sesquialkoxide, and alkylaluminum alkoxychloride A method according to any of the foregoing, wherein a polymerization catalyst is selected from the group consisting of: (C) The method according to any one of the above, wherein the component (C) uses a polymerization catalyst selected from at least one silane compound having a branched alkyl group or alkoxy group or an alicyclic group. (D) The method according to any one of the above, wherein the component (C) is a polymerization catalyst selected from at least one silane compound having an alkoxy group having 2 to 20 carbon atoms. (E) The method according to any one of the above, wherein the component (D) MetX _n is a halide of a metal selected from Fe, B, Sb, and Ga. (F) The polypropylene produced in the step (a) is 50 to 98% by weight of the block copolymer, and the propylene-ethylene copolymer produced in the step (b) is 50 to 2% by weight. A method according to any of the foregoing. (G) The method according to any of the above, wherein the propylene-ethylene copolymer produced in step (b) has an ethylene content of 30 to 95% by weight. (H) The method according to any one of the above, which is performed in the order of step (a) and step (b).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Component (A) in the catalyst of the present invention
Requires magnesium, titanium, halogen and an electron donating compound. Component (A) is a component known per se. Such a component is usually adjusted by contacting a magnesium compound, a titanium compound, an electron-donating compound, and, when the compound is a compound having no halogen, a halogen-containing compound.

The magnesium compound has the general formula MgR ^a R ^b
It is represented by Here, ^Ra and ^Rb represent the same or different hydrocarbon groups, OR 'groups (R' is a hydrocarbon group), and halogen atoms. More specifically, as the hydrocarbon group of R ^a and R ^b ,
An alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group is represented by OR 'group represented by R'
Is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group,
As the aryl group and the aralkyl group, examples of the halogen atom include chlorine, bromine, iodine, and fluorine.

Specific examples of these compounds are shown below. In the following chemical formula, Me: methyl, Et: ethyl, Pr:
Propyl, i-Pr: isopropyl, Bu: butyl, i
-Bu: isobutyl, t-Bu: tertiary butyl,
He: hexyl, Oct: octyl, Ph: phenyl,
cyHe: represents cyclohexyl.

MgMe ₂ , MgEt ₂ , Mg (i-Pr)
₂ , MgBu ₂ , MgHe ₂ , MgOct ₂ , MgEtB
u, MgPh ₂ , MgcyHe ₂ , Mg (OMe) ₂ , M
g (OEt) ₂ , Mg (OBu) ₂ , Mg (OHe) ₂ ,
Mg (OOct) ₂ , Mg (OPh) ₂ , Mg (OcyH
e) ₂ , EtMgCl, BuMgCl, HeMgCl,
i-BuMgCl, t-BuMgCl, PhMgCl,
PhCH ₂ MgCl, EtMgBr, BuMgBr, P
hMgBr, BuMgI, EtOMgCl, BuOMg
Cl, HeOMgCl, PhOMgCl, EtOMgB
r, BuOMgBr, EtOMgI, MgCl ₂ , Mg
Br ₂ , MgI ₂ .

The above magnesium compound can be prepared from metallic magnesium or another magnesium compound when preparing component A. Examples thereof include metallic magnesium, halogenated hydrocarbons and alkoxy group-containing compounds of the general formula (X ′) _n M (OR) _mn (wherein X ′ is a hydrogen atom, a halogen atom or a C 1 -C 2)
0 hydrocarbon groups, M is boron, carbon, aluminum,
A silicon or phosphorus atom, R represents a hydrocarbon group having 1 to 20 carbon atoms, m represents a valence of M, and m> n ≧ 0. ) Is contacted.

The hydrocarbon group of X and R in the general formula of the alkoxy group-containing compound includes methyl (Me), ethyl (Et), propyl (Pr), i-propyl, (i-P
r), alkyl groups such as butyl (Bu), i-butyl (i-Bu), hexyl (He), octyl (Oct), cycloalkyl groups such as cyclohexyl (cyHe) and methylcyclohexyl, allyl, propenyl, butenyl, etc. And an aryl group such as phenyl (Ph), tolyl and xylyl groups, and an aralkyl group such as phenethyl and 3-phenylpropyl. Among these, an alkyl group having 1 to 10 carbon atoms is particularly desirable. Hereinafter, specific examples of the alkoxy group-containing compound will be described.

Compounds wherein M is carbon C (OMe) ₄ , C (OEt) contained in formula C (OR) _4
4 , C (OPr) ₄ , C (OBu) ₄ , C (Oi-B
u) ₄ , C (OHe) ₄ , C (OOct) ₄ : Formula XC (O
R) ₃ contained in HC (OMe) ₃ , HC (OEt) ₃ ,
HC (OPr) ₃ , HC (OBu) ₃ , HC (OH
e) ₃ , HC (OPh) ₃ ; MeC (OMe) ₃ , Mec
(OEt) ₃ , EtC (OMe) ₃ , EtC (OE
t) ₃ , cyHeC (OEt) ₃ , PhC (OMe) ₃ ,
PhC (OEt) ₃ , CH ₂ ClC (OEt) ₃ , MeC
HBrC (OEt) ₃ , MeCHCLC (OEt) ₃ ; C
1C (OMe) ₃ , ClC (OEt) ₃ , ClC (Oi-
Bu) ₃ , BrC (OEt) ₃ ; MeCH (OMe) ₂ , MeCH (OEt) ₂ , CH contained in the formula X ₂ C (OR) _2
2 (OMe) ₂ , CH ₂ (OEt) ₂ , CH ₂ ClCH (O
Et) ₂ , CHCl ₂ CH (OEt) ₂ , CCl ₃ CH (O
Et) ₂ , CH ₂ BrCH (OEt) ₂ , PhCH (OE
t) ₂ .

Compound when M is silicon Si (0Me) ₄ , Si (O) contained in the formula Si (OR) ₄
Et) ₄ , Si (OBu) ₄ , Si (Oi-Bu) ₄ , S
i (OHe) ₄ , Si (OOct) ₄ , Si (OP
h) ₄ : HSi (OEt) contained in the formula XSi (OR) _3
3 , HSi (OBu) ₃ , HSi (OHe) ₃ , HSi
(OPh) ₃ ; MeSi (OMe) ₃ , MeSi (OE
t) ₃ , MeSi (OBu) ₃ , EtSi (OEt) ₃ ,
PhSi (OEt) ₃ , EtSi (OPh) ₃ ; ClSi
(OMe) ₃ , ClSi (OEt) ₃ , ClSi (OB
u) ₃ , ClSi (OPh) ₃ , BrSi (OEt) ₃ ;
Me ₂ Si (OMe) ₂ in an expression X ₂ Si (OR) _2,
Me ₂ Si (OEt) ₂ , Et ₂ Si (OEt) ₂ ; MeC
1Si (OEt) ₂ ; CHCl ₂ SiH (OEt) ₂ ; C
Cl ₃ SiH (OEt) ₂ ; MeBuSi (OEt) ₂ :
Me ₃ SiOMe, Me ₃ SiO contained in X ₃ SiOR
Et, Me ₃ SiOBu, Me ₃ SiOPh, Et ₃ Si
OEt, Ph ₃ SiOEt.

Compounds wherein M is boron B (OEt) ₃ , B (OBu) contained in formula B (OR) _3
3 , B (OHe) ₃ , B (OPh) ₃ .

Compound when M is aluminum Al (OMe) ₃ , Al (O) contained in the formula Al (OR) ₃
Et) ₃ , Al (OPr) ₃ , Al (Oi-Pr) ₃ , A
l (OBu) ₃ , Al (Ot-Bu) ₃ , Al (OHe)
₃ , Al (OPh) ₃ .

Compound when M is phosphorus P (OMe) ₃ , P (OEt) contained in formula P (OR) _3
3 , P (OBu) ₃ , P (OHe) ₃ , P (OPh) ₃ .

Further, as the magnesium compound, a complex with an organic compound of a metal (M ') of Group II or IIIa of the periodic table can be used. The complex has the general formula MgR
represented by ^{a R b · p (M'R c} q) (R a and R ^b are as defined above). As the metal (M '), aluminum, zinc, and calcium, and the like, R ^C is alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group, an aralkyl group. Also, q is the valence of the metal M 'and p is 0.
The number of 1-10 is shown. Specific examples of the compound represented by M′R ^C _q include AlMe ₃ , AlEt ₃ , Al (i-B
u) ₃ , AlPh ₃ , ZnMe ₂ , ZnEt ₂ , ZnB
_{u 2, ZnPh 2, CaEt 2} , CaPh 2 , and the like.

The titanium compound is a divalent, trivalent or tetravalent titanium compound, and examples thereof include titanium tetrachloride, titanium tetrabromide, trichloroethoxytitanium, trichlorobutoxytitanium, dichlorodiethoxytitanium, and dichlorodiethoxytitanium. Butoxytitanium, dichlorodiphenoxytitanium,
Examples thereof include chlorotriethoxytitanium, chlorotributoxytitanium, tetrabutoxytitanium, and titanium trichloride. Among these, tetravalent titanium halides such as titanium tetrachloride, trichloroethoxytitanium, dichlorodibutoxytitanium and dichlorodiphenoxytitanium are desirable, and titanium tetrachloride is particularly desirable.

Examples of the electron donating compound include carboxylic acids, carboxylic anhydrides, carboxylic esters, carboxylic halides, alcohols, ethers, ketones, amines, amides, nitriles, aldehydes,
Examples include alcoholates, phosphorus, arsenic and antimony compounds bonded to an organic group via carbon or oxygen, phosphoamides, thioethers, thioesters, carbon esters, and the like. Of these, carboxylic acids, carboxylic anhydrides, carboxylic esters, carboxylic halides, alcohols, and ethers are preferably used.

Specific examples of the carboxylic acid include aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, pivalic acid, acrylic acid, methacrylic acid and crotonic acid, and malonic acid. , Succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, aliphatic dicarboxylic acids such as fumaric acid, aliphatic oxycarboxylic acids such as tartaric acid, cyclohexane monocarboxylic acid, cyclohexene monocarboxylic acid, cis-1,2- Cyclohexanedicarboxylic acid, cis-4-methylcyclohexene-1,
Alicyclic carboxylic acids such as 2-dicarboxylic acid, benzoic acid, toluic acid, anisic acid, p-tert-butyl benzoic acid, naphthoic acid, aromatic monocarboxylic acids such as cinnamic acid, phthalic acid, isophthalic acid, Terephthalic acid, naphthalic acid, trimellitic acid, hemimellitic acid, trimesic acid, pyromellitic acid,
And aromatic polycarboxylic acids such as melitic acid. As the carboxylic acid anhydride, anhydrides of the above carboxylic acids can be used.

As the carboxylic acid ester, mono- or polyvalent esters of the above carboxylic acids can be used. Specific examples thereof include butyl formate, ethyl acetate, butyl acetate, isobutyl isobutyrate, propyl pivalate, and pivalic acid. Isobutyl, ethyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, diethyl malonate, diisobutyl malonate, diethyl succinate, dibutyl succinate, diisobutyl succinate, diethyl glutarate, dibutyl glutarate, diisobutyl glutarate Diisobutyl adipate, dibutyl sebacate, diisobutyl sebacate, diethyl maleate, dibutyl maleate, diisobutyl maleate, monomethyl fumarate, diethyl fumarate, diisobutyl fumarate, dietartrate , Dibutyl tartrate, diisobutyl tartrate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, methyl p-toluate, p-tert-butyl, ethyl benzoate, ethyl p-anisate, α-ethyl naphthoate, α-isobutyl isobutyl, ethyl cinnamate, monomethyl phthalate, monobutyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, dioctyl phthalate, di-2-ethylhexyl phthalate, diallyl phthalate, diphenyl phthalate , Diethyl isophthalate, diisobutyl isophthalate, diethyl terephthalate, dibutyl terephthalate, diethyl naphthalate, dibutyl naphthalate, triethyl trimellitate, tributyl trimellitate, tetramethyl pyromellitate, tetraethyl pyromellitate, Romerito acid tetrabutyl, and the like.

As the carboxylic acid halide, acid halides of the above carboxylic acids can be used.
Specific examples thereof include acetate chloride, acetate bromide, acetate iodide, propionate chloride, butyrate chloride,
Butyric acid bromide, Butyric acid iodide, Pivalic acid chloride, Pivalic acid bromide, Acrylic acid chloride, Acrylic acid bromide, Acrylic acid iodide, Methacrylic acid chloride, Methacrylic acid bromide, Methacrylic acid iodide, Crotonic acid chloride, Malonic acid chloride, Malonic acid bromide, Succinic chloride, succinic bromide,
Glutaric acid chloride, glutaric acid bromide, adipic acid chloride, adipic acid bromide, sebacic acid chloride,
Sebacic acid bromide, maleic acid chloride, maleic acid bromide, fumaric acid chloride, fumaric acid bromide, tartaric acid chloride, tartaric acid bromide, cyclohexanecarboxylic acid chloride, cyclohexanecarboxylic acid bromide, 1-
Cyclohexenecarboxylic acid chloride, cis-4-methylcyclohexenecarboxylic acid chloride, cis-4-methylcyclohexenecarboxylic acid bromide, benzoyl chloride,
Benzoyl bromide, p-toluic acid chloride, p-toluic acid bromide, p-anisic acid chloride, p-anisic acid bromide, α-naphthoic acid chloride, cinnamic acid chloride,
Examples include cinnamic acid bromide, phthalic acid dichloride, phthalic acid dibromide, isophthalic acid dichloride, isophthalic acid dibromide, terephthalic acid dichloride, and naphthalic acid dichloride. Also, adipic acid monomethyl chloride,
Monoalkyl halides of dicarboxylic acids such as monoethyl maleate chloride, monomethyl maleate chloride, butyl phthalate chloride may also be used.

Alcohols are represented by the general formula R ^d OH. In the formula, R ^d is alkyl, alkenyl, cycloalkyl, aryl, aralkyl having 1 to 12 carbon atoms. Specific examples include methanol, ethanol,
Propanol, isopropanol, butanol, isobutanol, pentanol, hexanol, octanol, 2-ethylhexanol, cyclohexanol, benzyl alcohol, allyl alcohol, phenol, cresol, xylenol, ethylphenol, isopropylphenol, p-tert-butylphenol, n -Octylphenol and the like.

The ether is represented by the general formula R ^e OR ^f. In the formula, R ^e , R ^f is alkyl, alkenyl, cycloalkyl, aryl, aralkyl having 1 to 12 carbon atoms, and R ^e and R ^f may be the same or different.
Specific examples thereof include diethyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, diisoamyl ether, di-2-ethylhexyl ether, diallyl ether, ethyl allyl ether, butyl allyl ether, diphenyl ether, anisole, and ethylphenyl ether. .

As a method for preparing the component (A), a magnesium compound (component 1), a titanium compound (component 2) and an electron donating compound (component 3) are contacted in that order. After contacting Component 1 with Component 3, contacting Component 2 or contacting Component 1, Component 2 and Component 3 simultaneously can be employed. Also, the contact with the halogen-containing compound can be performed before the contact of the component 2.

Examples of the halogen-containing compound include halogenated hydrocarbons, halogen-containing alcohols, silicon halide compounds having a hydrogen-silicon bond, Periodic Table IIIa
And halides of Group IVa, Group Va and Group Va elements (hereinafter referred to as metal halides).

Halogenated hydrocarbons include those having 1 to 1 carbon atoms.
Mono- and polyhalogen substituents of 12 saturated or unsaturated aliphatic, cycloaliphatic and aromatic hydrocarbons are used.
Specific examples of such compounds include, for aliphatic compounds, methyl chloride, methyl bromide, methyl iodide, methylene chloride, methylene bromide, methylene iodide, chloroform, bromoform, iodoform, carbon tetrachloride, carbon tetrabromide, Carbon iodide, ethyl chloride, ethyl bromide, ethyl iodide, 1,2-dichloroethane, 1,2-dibromoethane, 1,2-diiodoethane, methyl chloroform, methyl bromoform, methyl iodoform, 1,1,2-
Trichloroethylene, 1,1,2-tribromoethylene, 1,1,2,2-tetrachloroethylene, pentachloroethane, hexachloroethane, hexabromoethane, n-propyl chloride, 1,2-dichloropropane, hexachloropropylene, octachloropropane,
Decabromobutane, chlorinated paraffin and the like.
Examples of the alicyclic compound include chlorocyclopropane, tetrachlorocyclopentane, hexachlorocyclopentadiene, and hexachlorocyclohexane. For aromatic compounds, chlorobenzene, bromobenzene, o-dichlorobenzene, p-dichlorobenzene, hexachlorobenzene, hexabromobenzene, benzotrichloride, p-
-Chlorobenzotrichloride and the like. These compounds may be used alone or in combination of two or more.

As the halogen-containing alcohol, any one or two or more hydrogen atoms other than a hydroxyl group in a mono- or polyhydric alcohol having one or more hydroxyl groups in one molecule are substituted with a halogen atom. Compounds can be used. Examples of the halogen atom include chlorine, bromine, iodine, and fluorine atoms, and a chlorine atom is preferable.

Examples of these compounds include 2-chloroethanol, 1-chloro-2-propanol, 3-chloro-1-propanol, 1-chloro-2-methyl-2-propanol, 4-chloro-1-butanol, 5-chloro-1-pentanol, 6-chloro-1-hexanol,
3-chloro-1,2-propanediol, 2-chlorocyclohexanol, 4-chlorobenzhydrol,
(M, o, p) -chlorobenzyl alcohol, 4-chlorocatechol, 4-chloro- (m, o) -cresol,
6-chloro- (m, o) -cresol, 4-chloro-
3,5-dimethylphenol, chlorohydroquinone,
2-benzyl-4-chlorophenol, 4-chloro-1
-Naphthol, (m, o, p) -chlorophenol, p
-Chloro-α-methylbenzyl alcohol, 2-chloro-4-phenylphenol, 6-chlorothymol, 4-
Chlororesorcin, 2-bromoethanol, 3-bromo-1-propanol, 1-bromo-2-propanol,
1-bromo-2-butanol, 2-bromo-p-cresol, 1-bromo-2-naphthol, 6-bromo-2-
Naphthol, (m, o, p) -bromophenol, 4-
Bromoresorcin, (m, o, p) -fluorophenol, p-iodophenol: 2,2-dichloroethanol, 2,3-dichloro-1-propanol, 1,3-dichloro-2-propanol, 3-chloro -1- (α-chloromethyl) -1-propanol, 2,3-dibromo-
1-propanol, 1,3-dibromo-2-propanol, 2,4-dibromophenol, 2,4-dibromo-
1-naphthol: 2,2,2-trichloroethanol,
1,1,1-trichloro-2-propanol, β, β,
β, -trichloro-tert-butanol, 2,3,4
-Trichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,4
6-tribromophenol, 2,3,5-tribromo-
2-hydroxytoluene, 2,3,5-tribromo-4
-Hydroxytoluene, 2,2,2-trifluoroethanol, α, α, α-trifluoro-m-cresol,
2,4,6-triiodophenol: 2,2,4,6-
Tetrachlorophenol, tetrachlorohydroquinone, tetrachlorobisphenol A, tetrabromobisphenol A, 2,2,3,3-tetrafluoro-1-
And propanol, 2,3,5,6-tetrafluorophenol, tetrafluororesorcin and the like.

Examples of the silicon halide compound having a hydrogen-silicon bond include HSiCl ₃ , H ₂ SiCl ₂ , H ₃ S
iCl, H (CH ₃ ) SiCl ₂ , H (C ₂ H ₅ ) SiCl
_{2, H (t-C 4} H 9) SiCl 2, H (C 6 H 5) SiCl
_{2, H (CH 3) 2} SiCl, H (i-C 3 H 7) 2 SiC
_{l, H 2 (C 2 H} 5) SiCl, H 2 (n-C 4 H 9) Si
Cl, H ₂ (C ₆ H ₄ CH ₃ ) SiCl, HSiCl (C ₆
H ₅ ) _{2 and the} like.

As the metal halide, B, Al, Ga,
In, Tl, Si, Ge, Sn, Pb, As, Sb, B
i chlorides, fluorides, bromides, iodides,
In particular, BCl ₃ , BBr ₃ , BI ₃ , AlCl ₃ , AlB
r ₃ , GaCl ₃ , GaBr _3, InCl ₃ , TlCl ₃ , S
iCl ₄ , SnCl ₄ , SbCl ₅ , SbF _{5 and the} like are preferred.

The contact with the component 1, the component 2, the component 3 and the component 4, and optionally the halogen-containing compound which can be brought into contact, can be carried out by mixing or stirring in the presence or absence of an inert medium or by mechanical stirring. This is done by co-milling. The contact can be performed under heating at 40 to 150 ° C. As the inert medium, hexane, heptane, saturated aliphatic hydrocarbons such as octane, cyclopentane, saturated alicyclic hydrocarbons such as cyclohexane, benzene, toluene,
Aromatic hydrocarbons such as xylene can be used.

The component (A) is prepared as described above, and the component (A) may be washed with the above-mentioned inert medium, if necessary, and further dried. In component (A),
Preferably, 5 to 40% by weight of Mg, 1 to 2.5% by weight of Ti, 30 to 70% by weight of halogen, and 0 to 20% by weight of an electron donating compound are contained.

Preferred methods for preparing the component (A) in the present invention are described in JP-A-63-264607 and 58-1.
98503, 62-146904 and the like. More specifically, it is obtained by contacting (a) metallic magnesium, (b) a halogenated hydrocarbon, and (c) a compound of the general formula X _n M (OR) _mn (the same as the above-mentioned alkoxy group-containing compound). A method of contacting a magnesium-containing solid with (d) a halogen-containing alcohol and then with (e) an electron-donating compound and (f) a titanium compound (JP-A-63-163).
No. 264607), (a) contacting a magnesium dialkoxide with a (ii) silicon halide compound having a hydrogen-silicon bond, (c) contacting a titanium halide compound, and then (d) an electron donating compound (Optionally contacting with a titanium halide compound)
JP-A-146904), (a) contacting a magnesium dialkoxide with (b) a silicon halide compound having a hydrogen-silicon bond, (c) contacting with an electron donating compound, and then (d)
A method of contacting a titanium compound (JP-A-58-1985)
03 publication). Among these, the method is desirable.

Next, the organometallic component will be described. Component (B-1) is an organoaluminum compound in which the sum of the Pauling electronegativity values of the atoms bonded to one Al atom is less than 8. In a compound having two or more Al atoms, the sum of the electronegativities of the atoms bonded to each Al atom is obtained, and the determination is made based on the average value of all the atoms. Poling's electronegativity is widely known and, to name a few, H: 2.1, C: 2.5, O: 3.5, C
l: 3.0. Examples of the organoaluminum compound in which the sum of the values of the electronegativity of the poling of the atom bonded to one Al atom is less than 8 include the following compounds. One of these can be used alone or in combination of two or more.

Trialkylaluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tributylaluminum, triisobutylaluminum,
Trihexyl aluminum and the like.

The component (B-2) is an aluminum compound in which the sum of the poling electronegativity values of atoms bonded to one Al atom is 8 or more. In a compound having two or more Al atoms, the sum of the electronegativities of the atoms bonded to each Al atom is obtained, and the determination is made based on the average value of all the atoms. Examples of the aluminum compound in which the sum of the poling electronegativity values of the atoms bonded to one Al atom is 8 or more include the following compound groups. One of these can be used alone or in combination of two or more.

(I) dialkylaluminum monohalides, for example, dimethylaluminum chloride, dimethylaluminum bromide, ditylaluminum chloride,
Examples thereof include diethylaluminum bromide, diethylaluminum fluoride, dipropylaluminum chloride, di (n-butyl) aluminum chloride, diisobutylaluminum chloride, di (n-hexyl) aluminum chloride, and di (n-octyl) aluminumchloride.

(Ii) alkylaluminum dihalide,
For example, methylaluminum dichloride, ethylaluminum dichloride, ethylaluminum difluoride, methylaluminum dibromide, ethylaluminum dibromide, propylaluminum dichloride, n-butylaluminum dichloride, isobutylaluminum dichloride, n-hexylaluminum dichloride, n-octyl aluminum dichloride and the like.

(Iii) alkylaluminum sesquichlorides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, ethylaluminum sesquibromide, propylaluminum sesquichloride, n-butylaluminum sesquichloride, isobutylaluminum sesquichloride, n-hexylaluminum sesquichloride , N-octyl aluminum sesquichloride, ethyl aluminum sesquifluoride and the like.

(Iv) dialkylaluminum monoalkoxides such as dimethylaluminum methoxide, diethylaluminum ethoxide, dipropylaluminum ethoxide, diisopropylaluminum ethoxide, diisobutylaluminum ethoxide, di (n-butyl) aluminum ethoxide, di ( n-hexyl) aluminum ethoxide, di (n-octyl) aluminum ethoxide and the like.

(V) alkylaluminum dialkoxides, for example, methylaluminum diethoxide, ethylaluminum diethoxide, propylaluminum diethoxide, n-butylaluminum diethoxide, isobutylaluminum diethoxide, n-hexylaluminumdiethoxide And n-octyl aluminum diethoxide.

(Vi) Trialkoxy aluminums such as trimethoxy aluminum and triethoxy aluminum.

(Vii) Alkyl aluminoxanes such as methylaluminoxane and ethylaluminoxane.

(Viii) alkyl aluminum alkoxy halides such as methyl aluminum methoxy chloride, ethyl aluminum methoxy chloride, ethyl aluminum ethoxy chloride, ethyl aluminum ethoxy bromide, isobutyl aluminum methoxy chloride, isobutyl aluminum ethoxy chloride, isobutyl aluminum ethoxy bromide, isobutyl aluminum iso Propoxycyclolide, isobutyl aluminum isopropoxy bromide and the like can be mentioned.

(Ix) dialkylaluminum monophenoxide, for example diethylaluminum phenoxide,
Diisobutylaluminum phenoxide and the like.

(X) Aluminum trihalides such as aluminum trichloride and aluminum tribromide.

(Xi) Alkyl aluminum sesqui alkoxides such as methyl aluminum sesqui ethoxide, methyl aluminum sesqui ethoxide and the like.

In each of the above groups, preferably, alkyl is alkyl having 1 to 18 carbons, alkoxy is alkoxy having 1 to 10 carbons, and halides are chloride and bromide. Particularly preferably, the component (B-2)
Are dialkyl aluminum monochloride, dialkyl aluminum monobromide, alkyl aluminum dichloride, alkyl aluminum dibromide, alkyl aluminum sesquichloride, alkyl aluminum sesquibromide, dialkyl aluminum alkoxide, alkyl aluminum dialkoxide, alkyl aluminoxane, alkyl aluminum sesqui alkoxide, alkyl aluminum It is selected from the group consisting of alkoxy chlorides and alkyl aluminum alkoxy bromides.

Next, the component (C) alkylalkoxysilane compound will be described. Preferred alkylalkoxysilane compounds include, for example, those represented by the general formula

## STR1 ## (R ¹ ) _s Si (OR ² ) _4-s (in the above formula, R ¹ is each independently a carbon number of 1 to 6)
(Preferably 3 to 5) alkyl groups and cycloalkyl groups, wherein R ² is each independently
And s is a number in the range of 1 ≦ s ≦ 3), which is selected from the group consisting of an alkyl group, an alkenyl group and an alkynyl group. However, it is not limited to these.

Examples of R ¹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a sec-butyl group, a tert-amyl group, a cyclopentyl group and a cyclohexyl group. R ¹ is preferably selected from a propyl group, a cyclopentyl group, an isopropyl group and a tert-butyl group. As R ² , for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a sec-butyl group, a te
Examples thereof include an rt-amyl group, a cyclopentyl group, a cyclohexyl group, a 2-methyl-3-butenyl group, a 3-methyl-2-butenyl group, and a 2-methyl-3-butynyl group. R ² is preferably selected from a methyl group, an ethyl group, an isopropyl group, a sec-butyl group and a tert-butyl group.

As specific compounds, for example, tert-
Butoxycyclopentyldimethoxysilane, isopropoxycyclopentyldimethoxysilane, sec-butoxycyclopentyldimethoxysilane, di-sec-butoxypropylmethoxysilane, propyltriethoxysilane, tert-butylcyclopentyldimethoxysilane, tert-amyloxycyclopentyldimethoxysilane, (2- Methyl-3-butene-2-oxy) cyclopentyldimethoxysilane, (3-methyl-2-butene-1-oxy) cyclopentyldimethoxysilane,
(2-methyl-3-butene-2-oxy) cyclopentyldimethoxysilane, tert-butoxycyclohexyldimethoxysilane, isopropoxycyclohexyldimethoxysilane, sec-butoxycyclohexyldimethoxysilane, tert-amyloxycyclohexyldimethoxysilane, (2-methyl- (3-butene-2-oxy) cyclohexyldimethoxysilane, (3-methyl-2-butene-1-oxy) cyclohexyldimethoxysilane, (2-methyl-3-butene-2-oxy) cyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane , Dicyclopentyldimethoxysilane,
Cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxylan, cyclopentyltrimethoxylan and the like can be mentioned.

As the alkylalkoxysilane compound,
In addition to the above, a lactone group, an alkylalkoxylan containing a carboxyl group, a silicon atom as a ring-constituting atom,
Alkylalkoxysilanes having a heterocyclic substituent having a nitrogen atom can also be preferably used.

The preferred component (C) is a silane compound having a branched alkyl or alkoxy group or an alicyclic group, and particularly preferred is isopropoxycyclopentyldimethoxysilane, sec-butoxycyclopentyldimethoxylan, cyclohexylmethyldimethoxysilane. Silane, dicyclopentyldimethoxysilane, dise
At least one selected from c-butoxypropylmethoxysilane, tert-butylcyclopentyldimethoxysilane, and tert-amioloxycyclopentyldimethoxysilane.

The catalyst of the present invention comprises the above-mentioned components. Preferably, the component (B-1) is used in an amount of 70 to 600 mol and the component (B-
2) 2 to 200 mol and 10 to 30 mol of the component (C) are blended. More preferably, 90 to 400 mol of the component (B-1) per 1 mol of titanium in the component (A),
-2) is blended in an amount of 9 to 45 mol and the component (C) in an amount of 15 to 25 mol.

In the present invention, the component (A) may or may not be subjected to prepolymerization. When the prepolymerization is performed, the olefin containing the organoaluminum (component E) and the organosilicon compound (component F) may be used. This is done by contacting with. The organic aluminum (component E) is the same as the component (B-
1) One or more compounds selected from the compounds described in component (B-2) can be used. Among these, trialkyl aluminum, especially triethyl aluminum,
Triisobutylaluminum is preferred. As the organosilicon compound (component F), any of the compounds described in the above-mentioned component (C) can be used, but any other compounds having a total of four alkyl groups and alkoxy groups bonded to silicon atoms can be used. It is possible. For example, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetraisobutoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane methyltributoxysilane, methyltriphenoxysilane, ethyltriethoxysilane ethyltriisobutoxy Silane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltributoxysilane, isobutyltriisobutoxysilane, vinyltriethoxysilane, allyltrimethoxysilane,
Dimethyldiisopropoxysilane, dimethyldibutoxysilane, dimethyldiphenoxysilane, diethyldiethoxysilane, diethyldiisobutoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, dibenzyldiethoxysilane, divinyldiphenoxysilane, diallyldipropoxysilane , Diphenyldiallyloxysilane, methylphenyldimethoxysilane, chlorophenyldiethoxysilane and the like. Preferred organosilicon compounds (component F) are t-butoxycyclopentyldimethoxysilane, isopropoxycyclopentyldimethoxysilane or s-butoxycyclopentyldimethoxysilane.

Examples of the olefin used for the prepolymerization include, in addition to ethylene, α-olefins such as propylene, 1-butene, 1-hexene and 4-methyl-1-pentene. Prepolymerization is normal butane, isobutane,
Normal pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene,
It is preferably carried out in an inert hydrogen such as xylene. The prepolymerization is usually carried out at a temperature of 100 ° C or lower, preferably -30 ° C to +
The reaction is performed at a temperature of 30 ° C, more preferably -20 ° C to + 20 ° C. The polymerization system may be either a batch system or a continuous system, and may be performed in two or more stages.

Component (E) has a concentration of 10 to 10 in the prepolymerized system.
It is used in an amount of 500 mmol / l, preferably 30 to 200 mmol / l, and 1 to 50,000 mol per 1 mol of titanium in the component (A).
It is preferably used in an amount of 2 to 1,000 mol. Component (F) has a concentration of 1 to 1,000 in the prepolymerized system.
Mmol / liter, preferably 5-200 mmol /
Used to be liters. The olefin polymer is incorporated into the component (A) by the prepolymerization, and the amount of the polymer is 0.1 to 200 per gram of the component (A).
g, especially 0.5 to 50 g. The catalyst component thus prepared can be diluted or washed with the above-mentioned inert medium, but it is particularly preferable to wash it from the viewpoint of preventing catalyst deterioration. After washing, it may be dried if necessary. When storing the catalyst, it is preferable to store it at a temperature as low as possible.
° C, especially the temperature range of -20 ° C to + 5 ° C is recommended. Steps (a) and (b) are carried out in the presence of a catalyst composed of the component (A), the component (B-1), the component (B-2), and the component (C) which are or are not prepolymerized as described above. )I do.

In step (a), propylene is polymerized. As the reaction conditions in the polymerization of propylene, conventional conditions can be used. For example, the reaction is performed at a temperature of -80 to + 150 ° C, preferably 0 to 120 ° C, more preferably 40 to 120 ° C and 1 to 60 atm for 0.5 to 7 hours. The polymerization reaction may be performed in a gas phase or a liquid phase. When the reaction is carried out in a liquid phase, the reaction can be carried out in the above-mentioned inert medium or in a liquid monomer. Further, the polymerization may be performed in either a batch system or a continuous system. In order to control the molecular weight of the produced polymer, a known molecular weight controlling agent such as hydrogen can be present in the polymerization reaction system. In the step (a), the polypropylene obtained therefrom is 50 to 98% by weight, especially 70 to 95% by weight of the finally obtained block copolymer.
It is preferable that

Next, the step (b) will be described. Here, the copolymerization of propylene and ethylene is carried out together with the above-mentioned catalyst in the presence of a halogen-containing compound represented by the following formula (D): MetX _n (where X, Met and n are as defined above). Do. The copolymerization is carried out by contacting and reacting propylene with ethylene so that the ethylene content in the copolymer obtained therefrom is preferably 30 to 95% by weight, more preferably 40 to 80% by weight. . The conditions of the copolymerization reaction can be appropriately selected from the polymerization reaction conditions described in the step (a). Further, a molecular weight controlling agent can be present in the copolymerization reaction system. The amount of the copolymer block obtained in the step (b) is from 50 to 2% by weight, especially from 30 to 2% by weight of the finally obtained block copolymer.
Preferably, it is 5% by weight.

Component (D) to be present in step (b)
Is a halogen-containing compound represented by the following formula: MetX _n (wherein, X, Met and n are as defined above). Halogen is preferably chlorine or bromine. M
Examples of the metal atom represented by et include Li, Na, K,
Rb, Be, Mg, Ca, Sr, Ba, B, Ga, I
n, Tl, Ge, Sn, Pb, Al, Fe, Sb, Z
n, Co, Cr, Cu, Nb, Ni, Pt, Pd, M
n, Mg, Mo, Ru, Rh and the like. Met is preferably selected from Fe, B, Sb and Ga.

The amount of the component (D) to be used is preferably 1 to 100 mol, more preferably 2 to 10 mol, per 1 mol of the component (C) as a metal atom. In the method of the present invention, the steps (a) and (b) are preferably performed in that order, and the steps (a) and (b) can be performed any number of times.

[0065]

The present invention will be described in more detail with reference to the following examples. The percentages are by weight unless otherwise specified. The chemical analysis of the polymer was performed by the following method. The polymer yield per catalyst unit in steps (a) and (b) was determined by induction plasma emission spectroscopy, and from this value the polypropylene portion produced in step (a) and the propylene-ethylene copolymer produced in step (b) The ethylene content in the sample was determined by an infrared absorption spectrum.

The physical properties of the propylene-ethylene block copolymer were measured as follows. That is,
2,6-di-tert-butyl-4-methylphenol (BHT) is added to propylene-ethylene block copolymer.
0.18% by weight, distearyl thiodipropionate (DSTDP) 0.08% by weight, tetrakis-dimethylene- (3,5-ditert-butylhydroxyhydrocinnamate) methane (IRCANOX1010: trademark,
0.04% by weight (manufactured by Ciba Geigy) and 0.06% by weight of calcium stearate were added, and after dry blending, melt-kneaded and pelletized. Next, a test piece was injection-molded from the pellet and used for a physical property test.

The physical properties were measured according to the following methods. MFR: ASTM D1238 Flexural Modulus: JIS K7203-1982 Dupont Impact Strength: JIS K7211-1976 Example 1 (1) Preparation of Component (A) A 1 liter reaction vessel equipped with a reflux condenser was placed under a nitrogen gas atmosphere. , Chip-shaped metallic magnesium (purity 99.
8.3 g of 5%, average particle size of 1.6 mm) and 250 ml of n-hexane were added, and the mixture was stirred at 68 ° C. for 1 hour. The metal magnesium was taken out and dried at 65 ° C. under reduced pressure. Obtained.

Next, a suspension obtained by adding 140 ml of n-butyl ether and 0.5 ml of an n-butyl ether solution of n-butylmagnesium chloride (1.75 mol / l) to the metallic magnesium was maintained at 55 ° C. N-butyl chloride 3 in 50 ml of butyl ether
A solution in which 8.5 ml was dissolved was added dropwise over 50 minutes. After performing the reaction at 70 ° C. for 4 hours with stirring, the reaction solution was kept at 25 ° C.

Next, HC (OC ₂ H ₅ ) ₃ was added to the reaction solution.
55.7 ml was added dropwise over 1 hour. After dropping, 6
The reaction was carried out at 0 ° C. for 15 minutes, and the solid produced by the reaction was washed six times with 300 ml each of n-hexane and dried under reduced pressure at room temperature for 1 hour to obtain a magnesium-containing solid containing 19.0% and 28.9% of Mg. 31.6 g were recovered.

In a 300 ml reaction vessel equipped with a reflux condenser, a stirrer and a dropping funnel, under a nitrogen gas atmosphere,
6.3 g of magnesium-containing solid and 50 n-heptane
into a suspension and stirred at room temperature while stirring.
A mixed solution of 20 ml (0.02 mmol) of 2-trichloroethanol and 11 ml of n-heptane was dropped from the dropping funnel over 30 minutes, and further stirred at 80 ° C. for 1 hour. The obtained solid was filtered, and n-hexane at room temperature for 10
Wash 4 times with 0 ml, then add 2 ml with 100 ml each of toluene.
Washed twice to obtain a solid component.

To the above solid component, 40 ml of toluene was added, and titanium tetrachloride was further added so that the volume ratio of titanium tetrachloride / toluene was 3/2, and the temperature was raised to 90 ° C. Under stirring, a mixed solution of 2 ml of dibutyl phthalate and 5 ml of toluene was added dropwise over 5 minutes, followed by stirring at 120 ° C. for 2 hours. Further, titanium tetrachloride was newly added so that the volume ratio of titanium tetrachloride / toluene was 3/2, and
Stirred at C for 2 hours. The obtained solid substance was filtered at 110 ° C. and washed seven times with 100 ml of n-hexane at room temperature. Thus, 5.5 g of the component (A) was obtained.

(2) Polymerization of propylene (Step a) In a 1.5-liter stainless steel autoclave equipped with a stirrer, 8.1 mg of the catalyst component obtained in the above (1) and Mmol,
Isopropoxydimethoxycyclopentylsilane 0.0
8 mmol, ethyl aluminum sesquichloride 0.
16 mmol and 6 ml of n-heptane were mixed, and the mixture kept for 5 minutes was added. Then, after 3000 cc of hydrogen (normal temperature, normal pressure) as a molecular weight controlling agent and 1 liter of liquid propylene were injected, the temperature of the reaction system was increased to 70 ° C., and when propylene was polymerized for 59 minutes, 70 mg of iron trichloride was added.
Was suspended in 5 ml of hexane. One minute later, the stirring of the autoclave was stopped, and at the same time, hydrogen and unreacted propylene were purged.
The pressure was set to 2 kg / cm ² G, and after partially collecting the first-stage polymer (polypropylene), hydrogen was introduced into the system.

(3) Copolymerization of propylene and ethylene (step b) Following (2), the molar ratio of propylene to ethylene is
By supplying a mixed gas of 1.5, propylene and ethylene were copolymerized. Keep the internal pressure at 6kg / cm ² G,
The copolymerization was performed at 75 ° C. for 2 hours. After completion of the polymerization, the unreacted gas was purged, and the polymer was taken out and dried. The unreacted gas contained 0.5 mol% of hydrogen.

The MFR of the polymer finally obtained is 1
It was 0.5 dg / min. As a result of the analysis, step (b)
Was 20% by weight, and the ethylene content in the copolymer was 49% by weight. The MFR of the polymer sampled after the step (a) was 30.5 dg / min. When the physical properties of the final polymer were measured, the flexural modulus was 8.31 × 10 ³ kg / cm ² and the DuPont impact strength was 9
It was 1.3 kg · cm.

Examples 2 to 4 In the polymerization process of propylene, silane compounds shown in Table 1 were used in place of isopropoxycyclopentyldimethoxysilane, and aluminum compounds shown in Table 1 were used in place of ethylaluminum sesquichloride. -A block copolymer was produced in the same manner as in Example 1 except that a halogen-containing compound shown in Table 1 was used instead of iron trichloride in the ethylene copolymerization step. Table 1 shows the results of the polymerization ratio of each block, the MFR, and the physical properties of the polymer.

Comparative Examples 1 to 3 In the propylene polymerization step, isopropoxycyclopentyldimethoxysilane or the silane compound shown in Table 1 was used, and the aluminum compound shown in Table 1 was used in place of ethylaluminum sesquichloride or not. Example 1 with and without the presence of iron trichloride in the propylene-ethylene copolymerization step
A block copolymer was produced in the same manner as described above. Table 1 shows the results such as the polymerization ratio of each block, MFR, and the physical properties of the polymer.

[0077]

[Table 1]

[0078]

According to the present invention, it is possible to obtain a propylene-ethylene block copolymer having a high flow rate and an excellent balance between rigidity and impact resistance.

[Brief description of the drawings]

FIG. 1 is a flowchart of a catalyst component and a polymerization method according to the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenichiro Suzuki 1-3-1 Nishitsurugaoka, Oi-machi, Iruma-gun, Saitama Prefecture Tonen Co., Ltd. (72) Inventor Satoshi Shimizu Nishi-Tsuruga, Oi-machi, Iruma-gun, Saitama 1-3-1 Oka, Tonen Co., Ltd., Research Institute (72) Inventor Issei Aichi, 1-3-1 Nishitsurugaoka, Oi-machi, Iruma-gun, Saitama Prefecture Tonen Co., Ltd. (72) Inventor Kunihiko Imanishi Saitama 1-3-1 Nishi-Tsurugaoka, Oi-machi, Iruma-gun

Claims (1)

[Claims] (A) a solid component containing magnesium, titanium, a halogen and an electron donating compound as essential components, and (B-1) a value of the electronegativity of Pauling of an atom bonded to one Al atom. (B-2) an aluminum compound wherein the sum of the values of the electronegativity of the poling of the atoms bonded to one Al atom is 8 or more, and (C) alkyl In a method for producing a propylene-ethylene block copolymer, wherein (a) a step of polymerizing propylene and (b) a step of copolymerizing propylene and ethylene are carried out in the presence of a polymerization catalyst comprising an alkoxysilane compound. the (b), (D) the following formula: MetX _n (in the formula, Met represents a metal atom; X represents a halogen atom; n represents a valence of the metal Met) Wherein the carried out in the presence of a halogen-containing compound represented.