JPH10176009A - Production of propylene-ethylene block copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing the subject copolymer excellent in balance of physical properties between rigidity and impact resistance, by adding a specific halogen-containing compound to a production system. SOLUTION: In producing a highly crystalline polypropylene by polymerizing (B) propylene to give a highly crystalline polypropylene and copolymerizing the component B with (C) ethylene in the presence of (A) a polymerization catalyst comprising (i) a solid component composed of magnesium, titanium, a halogen, a metal oxide and an electron donative compound as essential components, (ii) an organoaluminum compound and (iii) an alkylalkoxysilane compound, (D) halogen-containing compound of the formula MetXn . (X is a halogen; Met is a metal atom except Al; (n) is the valence of the metal Met) (e.g. iron trichloride) is added to the production system. The compounding ratio of the polymerization catalyst is 1-2,000mol of the component B based on 1mol of titanium in the component A and 0.1-40mol calculated as Al of the component B based on 1mol of the component C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a propylene-ethylene block copolymer.

[0002]

2. Description of the Related Art A propylene polymerization catalyst comprising a catalyst component containing Mg, Ti, a halogen and an electron donating compound as essential components, an organic aluminum compound and a silane compound is well known. At that time, the stereoregularity of the obtained 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 the rigidity of the molded article has been improved.

[0003] Furthermore, since polypropylene originally has a disadvantage of low impact resistance, a method of improving impact resistance by copolymerizing other olefins such as ethylene has been widely used. However, with this method,
The impact resistance improves, but the rigidity decreases accordingly.
Therefore, various methods have been proposed to improve the balance between the rigidity of the copolymer and the physical properties of impact resistance by performing stepwise polymerization while changing the polymerization ratio of propylene and other olefins, that is, by performing multistage polymerization. (For example,
No. 44564). As another improvement method, it is also known that a specific silicon compound is present during the copolymerization (JP-A-6-73113). However, none of these methods has yet yielded a polymer having a sufficiently good balance between rigidity and impact resistance.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a propylene-ethylene block copolymer having a good balance between rigidity and impact resistance.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that by adding a specific halogen-containing compound during the copolymerization reaction of propylene and ethylene, the physical properties of rigidity and impact resistance can be balanced. The inventors have found that an excellent copolymer can be obtained, and have completed the present invention.

That is, the present invention relates to a polymerization comprising (A) a solid component comprising magnesium, titanium, a halogen, a metal oxide and an electron-donating compound as essential components, (B) an organoaluminum compound and (C) an alkylalkoxysilane compound. In the method for producing a propylene-ethylene block copolymer, (a) a step of polymerizing propylene to produce a highly crystalline polypropylene, and (b) a step of copolymerizing propylene and ethylene in the presence of a catalyst. Step (b) is represented by the following formula (D): MetX _n (wherein X represents a halogen atom; Met represents a metal atom except Al; and n represents the valence of metal Met). The method is carried out in the presence of a halogen-containing compound.

Preferred embodiments of the present invention are described below. (A) The above method using a polymerization catalyst wherein the component (B) is selected from trialkylaluminum. (B) 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 a branched alkyl group or an alkoxy group or an alicyclic group. . (C) The method according to any of the above, wherein the component (C) uses a polymerization catalyst selected from at least one silane compound having an alkoxy group having 2 to 20 carbon atoms. (D) Component (D) present in step (b) is F
The method according to any one of the above, which is a halide of a metal selected from e, B, Sb and Ga. (E) 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. The method according to any of the above. (F) The method according to any one of the above, wherein the propylene-ethylene copolymer produced in the step (b) has an ethylene content of 30 to 95% by weight. (G) The method according to any of the above, which is performed in the order of step (a) and step (b).

[0008]

DETAILED DESCRIPTION OF THE INVENTION The component (A) in the polymerization catalyst used in the present invention contains magnesium, titanium, halogen, metal oxide and an electron donating compound as essential components. Component (A) is a component known per se. Such components are usually prepared by contacting a magnesium compound, a titanium compound, a metal oxide, and an electron-donating compound, and, in the case where each of the compounds has no halogen, a halogen-containing compound.

The magnesium compound has the general formula MgR ^a R
It is represented by ^b . Here, ^Ra and ^Rb represent the same or different hydrocarbon groups, OR 'groups (R' is a hydrocarbon group), and halogen atoms. More specifically, the hydrocarbon group of R ^a and R ^b includes an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group having 1 to 20 carbon atoms, and the OR ′ group includes R ′ having a carbon number of 1 to 20 carbon atoms. Examples of the halogen atom include 1 to 12 alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups, such as 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-B
u: isobutyl, t-Bu: tertiary butyl, He:
Hexyl, Oct: Octyl, Ph: Phenyl, cyH
e: each represents cyclohexyl.

MgMe ₂ , MgEt ₂ , Mg (i-Pr)
₂ , MgBu ₂ , MgHe ₂ , MgOct ₂ , MgEt
Bu, MgPh ₂ , MgcyHe ₂ , Mg (OM
e) ₂ , Mg (OEt) ₂ , Mg (OBu) ₂ , Mg
(OHe) ₂ , Mg (OOct) ₂ , Mg (OP
h) ₂ , Mg (OcyHe) ₂ , EtMgCl, BuM
gCl, HeMgCl, i-BuMgCl, t-BuMgC
1, PhMgCl, PhCH ₂ MgCl, EtMgB
r, BuMgBr, PhMgBr, BuMgI, EtO
MgCl, BuOMgCl, HeOMgCl, PhOM
gCl, EtOMgBr, BuOMgBr, EtOMg
I, MgCl ₂ , MgBr 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 1-20 A hydrocarbon group, M is a boron, carbon, aluminum, silicon or phosphorus atom, R is a hydrocarbon group having 1 to 20 carbon atoms, m is a valence of M, and m> n ≧ 0.) Is mentioned.

X 'of the general formula of the alkoxy group-containing compound
And the hydrocarbon group of R include 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. Alkenyl group, aryl group of phenyl (Ph), tolyl, xylyl group, and 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 (OE) contained in formula C (OR) ₄
t) ₄ , C (OPr) ₄ , C (OBu) ₄ , C (Oi−
Bu) ₄ , C (OHe) ₄ , C (OOct) ₄ : Formula XC
HC (OMe) ₃ , HC (OE) contained in (OR) ₃
t) ₃ , HC (OPr) ₃ , HC (OBu) ₃ , HC
(OHe) ₃ , HC (OPh) ₃ ; MeC (OM
e) ₃ , MeC (OEt) ₃ , EtC (OMe) ₃ , E
tC (OEt) ₃ , cyHeC (OEt) ₃ , PhC
(OMe) ₃ , PhC (OEt) ₃ , CH ₂ ClC (O
Et) ₃ , MeCHBrC (OEt) ₃ , MeCHCl
C (OEt) ₃ ; ClC (OMe) ₃ , ClC (OE
t) ₃ , ClC (Oi-Bu) ₃ , BrC (OE
t) ₃ ; MeCH (OM) contained in the formula X ₂ C (OR) ₂
e) ₂ , MeCH (OEt) ₂ , CH ₂ (OMe) ₂ ,
CH ₂ (OEt) ₂ , CH ₂ ClCH (OEt) ₂ , C
HCl ₂ CH (OEt) ₂ , CCl ₃ CH (OE
t) ₂ , CH ₂ BrCH (OEt) ₂ , PhCH (OE
t) ₂ .

Compound when M is silicon Si (OMe) ₄ , Si contained in the formula Si (OR) ₄
(OEt) ₄ , Si (OBu) ₄ , Si (Oi-Bu)
₄ , Si (OHe) ₄ , Si (OOct) ₄ , Si (O
Ph) ₄ : HSi (OE) contained in the formula XSi (OR) ₃
t) ₃ , HSi (OBu) ₃ , HSi (OHe) ₃ , H
Si (OPh) ₃ ; MeSi (OMe) ₃ , MeSi
(OEt) ₃ , MeSi (OBu) ₃ , EtSi (OE
t) ₃ , PhSi (OEt) ₃ , EtSi (OP
h) ₃ ; ClSi (OMe) ₃ , ClSi (OE
t) ₃ , ClSi (OBu) ₃ , ClSi (OP
h) ₃ , BrSi (OEt) ₃ ; Formula X ₂ Si (OR) ₂
Me ₂ Si (OMe) ₂ , Me ₂ Si (OE
t) ₂ , Et ₂ Si (OEt) ₂ ; MeClSi (OE
t) ₂ ; CHCl ₂ SiH (OEt) ₂ ; CCl ₃ Si
H (OEt) ₂ ; MeBuSi (OEt) ₂ : X ₃ Si
Me ₃ SiOMe, Me ₃ SiOEt contained in OR,
Me ₃ SiOBu, Me ₃ SiOPh, Et ₃ SiOE
t, Ph ₃ SiOEt.

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

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

Compound when M is phosphorus P (OMe) ₃ , P (OE) contained in formula P (OR) ₃
t) ₃ , P (OBu) ₃ , P (OHe) ₃ , P (OP
h) 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 ^a R ^b
· P is represented by (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 an 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. Examples thereof include titanium tetrachloride, titanium tetrabromide, trichloroethoxytitanium, trichlorobutoxytitanium, dichlorodiethoxytitanium, dichlorodiethoxytitanium, and the like. 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.

Metal oxides are listed in Groups II to IV of the Periodic Table of the Elements.
An oxide of an element selected from the group of families of elements, To illustrate _{them, B 2 O 3, MgO,} Al 2 O 3, SiO
_{2, CaO, TiO 2, ZnO} , ZrO 2, SnO 2,
BaO, ThO _{2 and the} like can be mentioned. Among them, B ₂
O ₃ , MgO, Al ₂ O ₃ , SiO ₂ , TiO ₂ , Zr
O ₂ is preferred, and SiO ₂ is particularly preferred. Further, composite oxides containing these metal oxides, for example, SiO ₂ -M
gO, SiO ₂ -Al ₂ O ₃ , SiO ₂ -TiO ₂ , S
_{iO 2 -V 2 O 5, SiO} 2 -Cr 2 O 3, SiO 2 -
TiO ₂ -MgO or the like can also be used.

These metal oxides are usually used in powder form. Since the form such as the size and shape of the powder often affects the form of the obtained olefin polymer, it is desirable to appropriately adjust the form. It is desirable that the metal oxide be fired at as high a temperature as possible for the purpose of removing poisonous substances when used, and that the metal oxide be handled so as not to come into direct contact with the atmosphere.

Examples of the electron donating compound include carboxylic acids, carboxylic anhydrides, carboxylic esters, carboxylic halides, alcohols, ethers, ketones, amines, amides, nitriles, aldehydes,
Examples thereof include alcoholates, phosphorus, arsenic and antimony compounds bonded to an organic group via carbon or oxygen, phosphoamides, thioethers, thioesters, and carbonate esters. 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. Aliphatic carboxylic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid and fumaric acid, aliphatic oxycarboxylic acids such as tartaric acid, cyclohexanemonocarboxylic acid, cyclohexenemonocarboxylic acid, cis-1,2- Cyclohexanedicarboxylic acid, cis-4-methylcyclohexene-1,2-
Alicyclic carboxylic acids such as dicarboxylic acids, benzoic acid, toluic acid, anisic acid, aromatic monocarboxylic acids such as p-tert-butylbenzoic acid, naphthoic acid, and cinnamic acid, phthalic acid, isophthalic acid, terephthalic acid And aromatic polycarboxylic acids such as naphthalic acid, trimellitic acid, hemimellitic acid, trimesic acid, pyromellitic acid and melitic acid.

As the carboxylic anhydride, anhydrides of the above carboxylic acids can be used.

As the carboxylic acid ester, mono- or polyvalent esters of the above-mentioned 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, diethyl tartrate, dibutyl tartrate, diisobutyl tartrate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, methyl p-toluate, p
-Tertiary butyl ethyl benzoate, ethyl p-anisate,
Ethyl α-naphthoate, isobutyl α-naphthoate, ethyl cinnamate, monomethyl phthalate, monobutyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, dioctyl phthalate, di-2-ethylhexyl phthalate, phthalate Diallyl acid, diphenyl phthalate, diethyl isophthalate, diisobutyl isophthalate, diethyl terephthalate, dibutyl terephthalate, diethyl naphthalate, dibutyl naphthalate, triethyl trimellitate, tributyl trimellitate, tetramethyl pyromellitate, tetraethyl pyromellitate, pyromellitic 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 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, Examples include cinnamic acid chloride, cinnamic acid bromide, phthalic acid dichloride, phthalic acid dibromide, isophthalic acid dichloride, isophthalic acid dibromide, terephthalic acid dichloride, and naphthalic acid dichloride. Further, monoalkyl halides of dicarboxylic acids such as adipic acid monomethyl chloride, maleic acid monoethyl chloride, maleic acid monomethyl chloride, and butyl phthalate chloride can 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 and R ^f are alkyl, alkenyl, cycloalkyl, aryl and 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, ethylphenyl ether and the like.

The component (A) is prepared by contacting a metal oxide (component 1), a magnesium compound (component 2), a titanium compound (component 3) and an electron donating compound (component 4) in that order. After contacting Component 1 and Component 2, contact Component 4 and Component 3 in that order. After contacting Component 1 and Component 2, contact Component 3 and Component 4 simultaneously. Component 2 and Component 3 After the contact, the components 4 and 1 are brought into contact in that order. After the components 2 and 4 are brought into contact, the components 3 and 1 are brought into contact in that order. The components 2, 3 and 4 are simultaneously brought into contact. After contact
A method such as contacting the component 1 can be employed. Also, the contact with the halogen-containing compound can be carried out before the contact of the component 3.

Examples of the halogen-containing compound include halogenated hydrocarbons, halogen-containing alcohols, silicon halide compounds having a hydrogen-silicon bond, group IIIa of the periodic table,
Examples include halides of Group IVa and Group Va elements (hereinafter, referred to as metal halides). As the halogenated hydrocarbon, mono- and polyhalogen-substituted saturated or unsaturated aliphatic, alicyclic and aromatic hydrocarbons having 1 to 12 carbon atoms 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, methylchloroform, methylbromoform, methyliodoform, 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. Examples of the aromatic compound include 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, 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) -chloro Benzyl 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-bromoresorcinol, (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-trichloro Phenol, 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: 2,3,4,6-tetrachlorophenol,
Examples thereof include tetrachlorohydroquinone, tetrachlorobisphenol A, tetrabromobisphenol A, 2,2,3,3-tetrafluoro-1-propanol, 2,3,5,6-tetrafluorophenol, and tetrafluororesorcin.

Examples of the silicon halide compound having a hydrogen-silicon bond include HSiCl ₃ , H ₂ SiCl ₂ , H
₃ SiCl, 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 SiCl, H 2} (C 2 H 5) SiCl, H 2 (n
-C ₄ H ₉ ) SiCl, H ₂ (C ₆ H ₄ CH ₃ ) SiC
1, 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 , SiCl ₄ , SnCl ₄ , SbCl ₅ , SbF _{5 and the} like are preferable.

Contact with component 1, component 2, component 3 and component 4, and optionally a halogen-containing compound, which can be contacted, can be carried out in the presence or absence of an inert medium.
This can be done by mixing and stirring or by mechanically co-milling. The contact can be performed under heating at 40 to 150 ° C.

As the inert medium, saturated aliphatic hydrocarbons such as hexane, heptane and octane, saturated alicyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene can be used. .

The preferred method for preparing the component (A) in the present invention is described in JP-A-58-162607, JP-A-55-94909, JP-A-55-115405, JP-A-57-108107 and JP-A-61-108. Two
Methods disclosed in 1109, 61-174204, 61-174205, 61-174206, 62-7706 and the like can be mentioned. More specifically, a method in which a reaction product of a metal oxide and a magnesium dialkoxide is brought into contact with an electron-donating compound and a tetravalent titanium halide (JP-A-58-162607); A method in which a reaction product of a hydrocarbyl halide compound is contacted with a Lewis base compound and titanium tetrachloride (JP-A-55-94909). A reaction product of a porous carrier such as silica and an alkylmagnesium compound is treated with titanium. A method of contacting with an electron-donating compound and a silicon halide compound before contacting with a compound (JP-A-55-115405 and JP-A-57-108107), metal oxides, alkoxy-containing magnesium compounds,
A method of contacting an aromatic polycarboxylic acid having a carboxyl group at the ortho position or a derivative thereof and a titanium compound (JP-A-61-174204), a metal oxide, an alkoxy group-containing magnesium compound,
A method of contacting a silicon compound having a hydrogen-silicon bond, an electron donating compound and a titanium compound (JP-A-61-1)
No. 74205) Metal oxide, alkoxy-containing magnesium compound,
A method in which a halogen element or a halogen-containing compound, an electron-donating compound and a titanium compound are brought into contact (Japanese Patent Application Laid-Open No.
-174206), a method of contacting a reaction product obtained by contacting a metal oxide, dihydrocarbylmagnesium and a halogen-containing alcohol with an electron-donating compound and a titanium compound (JP-A-61-21109), A method in which a solid obtained by contacting a metal oxide, hydrocarbyl magnesium and a hydrocarbyloxy group-containing compound (corresponding to the alkoxy group-containing compound) is contacted with a halogen-containing alcohol, and further contacted with an electron-donating compound and a titanium compound ( JP
62-7706). Of these, methods (1) and (2) are particularly desirable.

The component (A) is prepared as described above. The component (A) may be washed with the above-mentioned inert medium, if necessary, and further dried.

In the component (A), Mg is preferably 2 to 2.
12% by weight, 1 to 5% by weight of Ti, 10 to 35% by weight of halogen, 30 to 70% by weight of metal oxide, 0% of electron donating compound
-20% by weight.

Next, the organometallic component will be described.

As the component (B) organoaluminum compound, for example, the following formula:

[0043]

(R ^k ) _r Al (Y) _{3 -r} (where R ^k is each independently a group selected from an alkyl group and an aryl group, and Y is each independently a halogen atom, A group selected from an alkoxy group, an aryloxy group and a hydrogen atom, and r is an arbitrary number in the range of 0 ≦ r ≦ 3), but is not limited thereto. Preferably, one of the following compounds
A single species or a combination of two or more species can be selected and used. (i) dialkylaluminum monohalides such as dimethylaluminum chloride, dimethylaluminum bromide, diethylaluminum chloride, diethylaluminum bromide, diethylaluminum fluoride, dipropylaluminum chloride, di (n-butyl)
Aluminum chloride, diisobutylaluminum chloride, di (n-hexyl) aluminum chloride, di (n-
Octyl) aluminum chloride and the like. (ii) alkylaluminum dihalides, such as methylaluminum dichloride, ethylaluminum dichloride, ethylaluminum difluoride, methylaluminum dibromide, ethylaluminum dibromide, propylaluminum dichloride, n-butylaluminum dichloride, isobutylaluminum dichloride, n-hexyl Aluminum dichloride, n-octyl aluminum dichloride and the like can be mentioned. (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 can be mentioned. (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-hexylaluminum diethoxide,
n-octyl aluminum diethoxide and the like. (vi) trialkoxyaluminum, for example, trimethoxyaluminum, triethoxyaluminum and the like. (vii) Alkyl aluminoxanes such as methylaluminoxane and ethylaluminoxane. (viii) alkylaluminum alkoxy halides such as methylaluminum methoxychloride, ethylaluminum methoxychloride, ethylaluminum ethoxychloride, ethylaluminum ethoxybromide, isobutylaluminum methoxychloride, isobutylaluminum ethoxychloride, isobutylaluminum ethoxybromide, isobutylaluminum isopropoxychloride, Isobutyl aluminum isopropoxy bromide and the like. (ix) Dialkylaluminum monophenoxide, for example, diethylaluminum phenoxide, diisobutylaluminum phenoxide and the like. (x) Trialkylaluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tributylaluminum, triisobutylaluminum, trihexylaluminum and the like.

The alkyl group preferably has 1 carbon atom.
To 18 alkyl groups, the alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms, and the halide is preferably chloride and bromide. The aryl group is, for example, a phenyl group, and the aryloxy group is, for example, a phenoxy group.

Of these, trialkylaluminum is preferable, and triethylaluminum and triisobutylaluminum are particularly preferable. Trialkylaluminum is another organic aluminum compound, for example, industrially available diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride, diethylaluminum ethoxide,
It can be used in combination with diethyl aluminum hydride or a mixture or complex compound thereof.

Alternatively, it is also possible to use an organic aluminum compound other than those described above, for example, an organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom. Examples of such a compound include (C ₂ H ₅ ) ₂ AlOAl (C ₂ H
₅ ) ₂ , (C ₄ H ₉ ) ₂ AlOAl (C ₄ H ₉ ) ₂ ,
_{(C 2 H 5) 2 AlN} (C 2 H 5) Al (C 2 H 5) 2
And the like.

The component (C) alkylalkoxysilane compound has, for example, the following formula:

[0048]

## STR2 ## (R ¹ ) _s Si (OR ² ) _4-s (wherein R ¹ is each independently a C 1-6)
(Preferably 3 to 5) alkyl groups and cycloalkyl groups, wherein R ² is each independently
(S is a number in the range of 1 ≦ s ≦ 3). However, it is not limited to these.

As R ¹ , for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a se
c-butyl group, tert-amyl group, cyclopentyl group, cyclohexyl group and the like. 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,
Ethyl, propyl, isopropyl, tert-butyl, sec-butyl, tert-amyl, cyclopentyl, cyclohexyl, 2-methyl-3-butenyl, 3-methyl-2-butenyl, 2- And a 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.

Specific compounds include, for example, tert-butoxycyclopentyldimethoxysilane, isopropoxycyclopentyldimethoxysilane, sec-butoxycyclopentyldimethoxysilane, di-sec-butoxypropylmethoxysilane, propyltriethoxysilane,
Butylcyclopentyldimethoxysilane, tert-amyloxycyclopentyldimethoxysilane, (2-methyl-3
-Butene-2-oxy) cyclopentyldimethoxysilane, (3-methyl-2-buten-1-oxy) cyclopentyldimethoxysilane, (2-methyl-3-butyn-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-butyn-2-oxy) cyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane, cyclopentyltrimethoxysilane and the like.

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

The preferred component (C) is a silane compound having a branched alkyl or alkoxy group or an alicyclic group, particularly preferably isopropoxycyclopentyldimethoxysilane, sec-butoxycyclopentyldimethoxysilane, cyclohexylmethyl. Dimethoxysilane, di sec-butoxypropylmethoxysilane, te
At least one selected from rt-butylcyclopentyldimethoxysilane and tert-amyloxycyclopentyldimethoxysilane.

The polymerization catalyst used in the present invention comprises the above-mentioned components. Preferably, the component (B) is used in an amount of 1 to 2,000 moles per mole of titanium in the component (A).
More preferably, 20 to 500 mol of the component (B) is blended. The ratio of component (B) to component (C) is 0.1 to 40 moles, preferably 1 to 25 moles, calculated as component (B) Al, per mole of component (C). .

In the polymerization catalyst used in the present invention, the component (A) may or may not be subjected to prepolymerization. When the prepolymerization is carried out, the organoaluminum (component e) and optionally the organosilicon compound ( It is carried out by contacting with an olefin in the presence of component f). The organoaluminum (component e) can be used by selecting one or more compounds from the compounds exemplified in the aforementioned component (B). Of these, trialkylaluminums, particularly triethylaluminum and triisobutylaluminum, are preferred. As the organosilicon compound (component f), any of the compounds exemplified in the above-mentioned component (C) can be used, but other compounds having a total of four alkyl groups and alkoxy groups bonded to a silicon atom can also be used. It is. For example, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetraisobutoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane,
Methyltributoxysilane, methyltriphenoxysilane, ethyltriethoxysilane, ethyltriisobutoxysilane, 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 in the prepolymerization include, in addition to ethylene, α-olefins such as propylene, 1-butene, 1-hexene and 4-methyl-1-pentene. The prepolymerization is preferably carried out in the above-mentioned inert medium. The prepolymerization is usually performed at a temperature of 100 ° C or lower, preferably at a temperature of -10 ° C to + 50 ° 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 5 in the prepolymerized system.
It is used in an amount of 00 mmol / l, preferably 30 to 200 mmol / l, and 1 to 50,000 mol, preferably 2 to 1,000 mol, per 1 mol of titanium in the component (A). Used. Component f
Is used so that the concentration in the prepolymerization system is 1 to 1,000 mmol / L, preferably 5 to 200 mmol / L. The olefin polymer is taken into the component (A) by the prepolymerization, and the amount of the polymer is preferably 0.1 to 100 g per 1 g of the component (A). 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.
A temperature range of 50C to + 30C, especially -20C to + 5C is recommended.

Steps (a) and (b) are carried out in the presence of a polymerization catalyst consisting of component (A), components (B) and (C), which is or is not prepolymerized as described above. In the step (a), propylene is polymerized.
As the reaction conditions in the polymerization of propylene, conventional conditions can be used. For example, -80 to + 150 ° C, preferably 0 to 120
C., more preferably from 40.degree. To 120.degree. C. and from 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 mixed with 50 to 9 of the finally obtained block copolymer.
Preferably, it is 8% by weight, especially 70-95% by weight.

Next, the step (b) will be described. Here, the copolymerization of propylene and ethylene is carried out together with the above-described catalyst in the presence of a halogen-containing compound represented by (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 (where 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, R
b, Be, Mg, Ca, Sr, Ba, B, Ga, In,
Tl, Ge, Sn, Pb, Fe, Sb, Zn, Co, C
r, Cu, Nb, Ni, Pt, Pd, Mn, Mo, R
u, Rh and the like. Met is preferably Fe, B,
It is selected from 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.

The method of the present invention comprises the steps (a) and (b)
Are preferably performed in that order, and steps (a) and (b) can be performed any number of times.

[0062]

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 produced in step (b) were obtained. The polymerization amount ratio of the copolymer part was determined. Further, the ethylene content in the propylene-ethylene copolymer obtained in the step (b) was determined by an infrared absorption spectrum.

The physical properties of the propylene-ethylene block copolymer were measured as follows. That is,
To a propylene-ethylene block copolymer, 0.18% by weight of 2,6-di-tert-butyl-4-methylphenol (BHT) and distearyl thiodipropionate (DSTD)
P) 0.08% by weight, tetrakis- {methylene- (3,5-ditert-butylhydroxyhydrocinnamate) methane (IRGANOX1010: trade name, manufactured by Ciba Geigy)
After adding 0.04% by weight and 0.06% by weight of calcium stearate and dry blending them, melt-kneading them,
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 K 7203-11982 Dupont Impact Strength: JIS K 7211-1976 Example 1 (1) Preparation of Component (A) A 200 ml flask equipped with a dropping funnel and a stirrer was filled with nitrogen gas. Replaced. This flask was baked in a nitrogen stream at 200 ° C. for 2 hours and further at 700 ° C. for 5 hours. Silicon oxide (Davison, trade name G)
952) 5 g and 40 ml of n-heptane were charged. Further, 20 ml of a 20% -n-heptane solution of n-butylethylmagnesium (hereinafter, referred to as BEM) (manufactured by Texas Alkyls, trade name: MAGALA BEM) was added, and 90 ° C.
For 1 hour.

After the obtained suspension was cooled to 0 ° C., a solution of 11.2 g of tetraethoxysilane dissolved in 20 ml of n-heptane was dropped from the dropping funnel over 30 minutes. After dropping, the temperature was raised to 50 ° C over 2 hours,
Stirring was continued for hours. After completion of the stirring, the supernatant was removed by decantation, and the resulting solid was washed with 60 ml of n-heptane at room temperature, and the supernatant was removed by decantation. This washing treatment with n-heptane was further performed four times.

To the above solid, 50 ml of n-heptane was added to form a suspension, and 2,2,2-trichloroethanol 8.0 was added thereto.
g in 10 ml of n-heptane was dropped from the dropping funnel at 25 ° C. over 15 minutes. After dropping, 25 ° C
For 30 minutes. After completion of stirring, at room temperature, 60
Washing was performed twice with ml of n-heptane and three times with 60 ml of toluene. When the obtained solid (referred to as solid component I) was analyzed, SiO ₂ : 36.6%, Mg: 5.
It contained 1% and Cl: 38.5%.

The solid component I obtained above was added to n-heptane
10 ml and 40 ml of titanium tetrachloride were added, the temperature was raised to 90 ° C., and di-n-butyl phthalate was dissolved in 5 ml of n-heptane.
6 g was added over 5 minutes. Thereafter, the temperature was raised to 115 ° C., and the reaction was carried out for 2 hours. After the temperature was lowered to 90 ° C., the supernatant was removed by decantation, and the mixture was washed twice with 70 ml of n-heptane. In addition, 15 ml of n-heptane and titanium tetrachloride
40 ml was added and reacted at 115 ° C. for 2 hours. After completion of the reaction, the obtained solid substance was washed eight times with 60 ml of n-hexane at room temperature. Next, drying was performed at room temperature under reduced pressure for 1 hour to obtain 8.3 g of a solid component (component A). As a result of analysis, this component A contained 3.1% by weight of Ti,
In addition, it was confirmed that Si, Mg, Cl and di-n-butyl phthalate were contained.

(2) Polymerization of Propylene (Step a) In a 1.5-liter stainless steel autoclave equipped with a stirrer, the catalyst component A2 obtained in the above (1) was placed under a nitrogen atmosphere.
0.7 mg, 0.4 mmol of triethylaluminum, 0.08 mmol of isopropoxycyclopentyldimethoxysilane and 4 ml of n-heptane were mixed, and the mixture kept for 5 minutes was added. Then, 3000m of hydrogen as a molecular weight controlling agent
1 (normal temperature, normal pressure) and 1 liter of liquid propylene were injected, and then the temperature of the reaction system was raised to 70 ° C. to start polymerization of propylene. After polymerization for 59 minutes, iron trichloride 70m
g was suspended in 5 ml of hexane. After one minute, the stirring of the autoclave was stopped, hydrogen and unreacted propylene were purged at the same time, the internal pressure of the autoclave was set to 0.2 kg / cm ² G, and a part of the first-stage polymer (polypropylene) was collected. Then, hydrogen was introduced into the system.

(3) Copolymerization of propylene and ethylene (step b) Subsequent to (2), a mixed gas having a molar ratio of propylene to ethylene of 1: 1.5 is supplied to carry out copolymerization of propylene and ethylene. (Where the iron trichloride injected in (2) is still present). 6kg inside pressure
/ Cm ² G, and copolymerized 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 0.6 mol% of hydrogen.

The MFR of the finally obtained propylene-ethylene block copolymer was 10.5 g / 10 minutes. As a result of the analysis, the production amount of the propylene-ethylene copolymer in the step (b) was 21% by weight, and the ethylene content was 49% by weight.
Met. The MFR of the polypropylene obtained in the step (a) was 29.2 g / 10 minutes.

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

Comparative Examples 1-2 In the propylene polymerization step, the silane compounds shown in Table 1 were used in place of isopropoxycyclopentyldimethoxysilane, and no iron trichloride was present in the propylene-ethylene copolymerization step. A block copolymer was produced in the same manner as in Example 1. Table 1 shows the results such as the weight ratio of each block and the physical properties of the polymer.

[0075]

[Table 1]

[0076]

According to the present invention, it is possible to produce a propylene-ethylene block copolymer having an excellent balance between physical properties of rigidity and impact resistance.

[Brief description of the drawings]

FIG. 1 is a flowchart schematically showing a preferred example of a process for producing a propylene-ethylene block copolymer of the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichiro Suzuki 1-3-1 Nishitsurugaoka, Oi-machi, Iruma-gun, Saitama Prefecture Inside the Tonen Co., Ltd. 1-3-1 Kaoka, Tonen Co., Ltd. (72) Inventor Kunihiko Imanishi 1-3-1, Nishitsurugaoka, Oi-machi, Iruma-gun, Saitama

Claims (1)

[Claims] 1. A polymerization catalyst comprising (A) a solid component containing magnesium, titanium, a halogen, a metal oxide and an electron donating compound as essential components, (B) an organoaluminum compound and (C) an alkylalkoxysilane compound. In the method for producing a propylene-ethylene block copolymer, wherein (a) a step of polymerizing propylene to produce a highly crystalline polypropylene, and (b) a step of copolymerizing propylene and ethylene, b) is represented by the following formula: (D) MetX _n (wherein X represents a halogen atom; Met represents a metal atom except Al; n represents the valency of metal Met) The method in the presence of.