JPH0327564B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for polymerizing olefins using a catalyst comprising a so-called carrier-type titanium component and an organoaluminum compound. More specifically, the present invention relates to a method for polymerizing α-olefins characterized by the catalyst used. This catalyst is highly active, and the resulting α-olefin polymer has a high degree of stereoregularity, high bulk density, and excellent particle size characteristics. Background of the Invention Ziegler-Natsuta type catalyst systems, which combine titanium halides and organoaluminum compounds, are widely used industrially for α-olefin polymerization, but the polymerization activity is not sufficient, and the resulting polymer is not halogenated. A step is required to remove catalyst residue derived from titanium. To improve this, in recent years the titanium halide component of the Ziegler-Natsuta type catalyst has been changed to MgCl ₂ , Mg(OH)Cl, Mg(OR) _o Cl _2-o (O≦
According to Japanese Patent Publication No. 39-1999, it is possible to use the compound by supporting it on a magnesium compound carrier such as n≦2), R is a hydrocarbon group).
12105, 52-50037, 43-13050, JP-A-53-
2580, 53-39991, etc. As a result, the activity per titanium unit has been greatly improved, and the titanium component remaining in the produced polymer has reached a negligible level. However, on the other hand, the magnesium halide contained in the catalyst, especially MgCl ₂ , which has strong hygroscopicity, Problems such as foaming of the polymer during molding and corrosion of the molding machine have arisen. On the other hand, for the purpose of reducing the halogen content, a method of supporting titanium halide or both titanium halide and magnesium halide on a metal oxide support such as SiO ₂ or Al ₂ O ₃ has been proposed in Japanese Patent Publication No. 51-5872. 1982-82105, same
55-120608, etc., but these have low activity and the stereoregularity of the produced polymer is insufficient, so that they have not reached a practical level. Object and Structure of the Invention The present invention uses a novel highly active polymerization catalyst using a metal oxide as a carrier, and uses α- It is an object of the present invention to provide a method for producing an olefin polymer. That is, the present invention provides α-
A method for polymerizing olefins, comprising: (A) (i) at least one metal oxide selected from oxides of elements of groups 2 to 4 of the periodic table, or at least one of these oxides; (ii) general formula Mg(OR ¹ ) _i (OR ² ) _2-i (however, R ¹ , R ²
are the same or mutually different alkyl groups, aryl groups, i is a number indicating 0≦i≦2)
a solid substance in which the magnesium compound represented by the formula (ii) is deposited on the surface of the (i) component by contacting the magnesium compound represented by the formula in an organic solvent; (iii) an electron-donating compound; and (iv) at least one 4 with a halogen atom of
The method is characterized in that the reaction is carried out in the presence of a catalyst consisting of a solid catalyst component obtained by reacting a titanium compound having a valence of 1 to 2, (B) an organoaluminum compound, and (C) an organic acid ester. The contents and effects of the present invention will be explained below, including each component in the preparation of the catalyst, which is the important point of the present invention. Preparation of catalyst components-1 Catalyst (A) component Typical examples of metal oxides and composite oxides that are component (i) of component (A) include MgO, CaO,
B ₂ O ₃ , ZrO ₂ , SiO ₂ , SnO ₂ , Al ₂ O ₃ , SiO ₂ −
Al ₂ O ₃ , SiO ₂ −MgO, SiO ₂ −TiO ₂ , SiO ₂ −
_Examples include _V2O5 , _SiO2 - _Cr2O3 , _SiO2 - _TiO2 -MgO, and particularly preferred are _SiO2 itself or _various composite oxides containing _SiO2 . These oxides are
It can also be used after surface treatment with various halogenating agents or organic aluminum compounds.
Furthermore, its specific surface area (BET method) is 10 to 800 m ² /
g, average pore size of 10 Å or more and average particle size of 0.1
Those in the range of ~1000μ are suitable for the purpose of the present invention. Examples of the magnesium compound represented by the general formula Mg (OR ¹ ) _i (OR ² ) _{2-i, which} is component (ii), include Mg
(−OCH ₃ ) ₂ , Mg(−OC ₂ H ₅ ) ₂ , Mg(−OC ₃ H ₇ ) ₂ ,
Mg(−OC ₄ H ₉ ) ₂ , Mg(−OC ₆ H ₁₃ ) ₂ , Mg(−
OC ₈ H ₁₇ ) ₂ ,

【formula】

【formula】

【formula】

【formula】

[Formula] Mg (-OCH ₃ ) (-OC ₂ H ₅ ),

【formula】

[Formula] etc., and in particular R ¹ and R ² are an alkyl group or an aryl group having 4 or more carbon atoms. The electron-donating compound (iii) is O, N,
Examples of electron-donating compounds containing P, S, and Si include esters, ethers, ketones, aldehydes, amines, amides, nitriles, thioesters, and thioethers. Esters include organic acid esters and inorganic acid esters such as carbonic acid, sulfuric acid, phosphoric acid, phosphorous acid and silicic acid. Furthermore, examples of organic acid esters include methyl formate, n-butyl formate, ethyl acetate, allyl acetate, 2-ethylhexyl butyrate, ethyl valerate,
Saturated or unsaturated aliphatic organic acid esters such as methyl acrylate, n-butyl crotonate, methyl chloroacetate, ethyl dichloroacetate, methyl benzoate, ethyl benzoate, n-propyl benzoate, i-propyl benzoate, Cyclopentyl benzoate, cyclohexyl benzoate, phenyl benzoate, styryl benzoate, ethyl salicylate, p-
Methyl oxybenzoate, cyclohexyl p-oxybenzoate, methyl anisate, i-butyl anisate, methyl p-ethoxybenzoate, methyl p-toluate, ethyl p-toluate, phenyl p-toluate, p- Also included are aromatic carboxylic acid esters such as ethyl aminobenzoate and dimethyl terephthalate, and alicyclic organic acid esters such as methyl cyclohexanecarboxylate and methylcyclohexanecarboxylic acid ester. Typical examples of inorganic acid esters include trimethyl phosphite,
Examples include triphenyl phosphite, diphenylethyl phosphonate, diethylbenzyl phosphonate, dipropyl sulfate, isoamyl sulfite, isoamyl nitrite, and ethyl silicate. Ethers include methyl ethyl ether, diethyl ether, dibutyl ether, isoamyl ether, diphenyl ether, etc. Ketones include acetone, methyl ethyl ketone, etc. Aldehydes include acetaldehyde, isobutyraldehyde, benzaldehyde, etc. Amines include ethylamine , n-propylamine,
Examples of the nitrile include aniline and N-methylaniline; examples of the nitrile include ethanenitrile and pentanedinitrile; examples of the amide include propanamide and pentanediamide; and examples of the thioether include allylbenzyl sulfide. These electron-donating compounds are preferably organic acid esters or ethers having an aromatic group or a group derived therefrom, and two or more types may be used in combination. (iv) The tetravalent titanium compound which is the component has the general formula
TiXk (OR ⁷ ) _4-k (where R ⁷ is an alkyl group, cycloalkyl group, or aryl group, X is a halogen atom, and k is a number of 1≦k≦4), and a typical example is Examples include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, methoxytitanium trichloride, dimethoxytitanium dichloride, and triethoxytitanium chloride. Among them, chlorine-containing titanium compounds such as titanium tetrachloride are preferred. A method for depositing the magnesium compound Mg(OR ¹ ) _i (OR ² ) _2-i on the surface of a metal oxide is to dissolve or disperse the compound prepared in advance in an organic solvent, and then to place the metal oxide on the surface. However, it is possible to use a magnesium compound in the presence or absence of an organic solvent without using a pre-made magnesium compound.
A method can be used in which Mg is reacted with R ¹ OH and/or R ² OH and deposited on the metal oxide surface. The former method uses Mg obtained by a known method.
(OR ¹ ) _i (OR ² ) _2-i and the metal oxide are placed in an organic solvent and brought into contact with each other. Examples of organic solvents used in this case include alcohols, ethers, esters, and ketones. , aliphatic, alicyclic and aromatic hydrocarbons. The contact temperature is 0 to 200°C, preferably 0 to 100°C, and the contact time is not particularly limited, but is generally 1 hour or more. After the contact, washing is performed with an organic solvent if necessary, and the solvent is further removed by drying to obtain the desired solid. The latter method corresponds to
Using R ¹ OH and/or R ² OH as a solvent (in this case, other organic solvents may also be used together), the metal oxide and Mg metal are charged, and the reaction is sufficiently heated at the boiling point of the alcohol. After the desired magnesium compound is deposited on the metal oxide, washing is performed with an organic solvent if necessary, and the solvent is further removed by drying to obtain the desired solid substance. In these methods, it is preferable from the viewpoint of catalytic performance that the magnesium compound be deposited as uniformly as possible on the surface of the metal oxide, and for this purpose, it is preferable to bring the magnesium compound into contact with the metal oxide in an organic solvent that can dissolve the magnesium compound. desirable. In addition, in the magnesium compound Mg(OR ¹ ) _i (OR ² ) _2-i ,
Particularly excellent catalytic performance is obtained when R ₁ and R ₂ are an alkyl group or an aryl group having 4 or more carbon atoms.
Generally, there are few organic solvents that can dissolve these magnesium compounds, and in these cases, it is desirable to use the following method. In other words, as a more preferable method in terms of catalyst performance, Mg(OR ³ ) is once removed by any of the above methods.
(OR ⁴ ) (However, R ³ and R ⁴ are methyl or ethyl groups)
The solid substance deposited with R ⁵ OH (where R ⁵ is an alkyl group or aryl group having 4 or more carbon atoms) is
There is a method of reacting at a temperature of 100°C. According to this method, a catalyst component with high performance can be easily obtained even if the R ¹ and R ² groups are strongly hydrophobic.
In this reaction, the presence of an organic solvent is not essential, but is generally desirable. The solid material obtained in the above manner is used as a support for 1 mole of component (i) metal oxide (total number of moles of each oxide in the case of a composite oxide).
Mg compound 0.001-10.0 mol, preferably 0.01-1.0
Contains moles. The reaction between the above-mentioned solid and the electron-donating compound as component (iii) can also be carried out by coexisting the electron-donating compound during the preparation of the solid, but preferably the solid and the electron-donating compound are allowed to coexist. It is desirable to contact the compound in an inert solvent such as hexane, heptane, benzene, toluene, or the like. The concentration of electron-donating compound in the inert solvent is 0.02 to 20 mol/
1 is preferable, and 0.05 to 1.5 mol/l is particularly preferable. There is no particular restriction on the reaction temperature, but it is usually 10 to 200℃.
In particular, a temperature range of 50 to 130°C gives preferable results. The reaction solution may be used as is, washed with an inert solvent, or dried (if necessary under reduced pressure). (iv) Component titanium compound and (i), (ii) and (iii)
The reaction with the product obtained by the reaction of can be carried out in an inert solvent or in the titanium compound. The reaction temperature is 10 to 250°C, preferably 20 to 150°C. Free titanium compounds are removed by washing with an inert solvent or drying (optionally under reduced pressure). Component (A) thus obtained usually contains 0.1 to 10 wt% of titanium atoms. -2 Catalyst (B) component The organic aluminum compound used for component (B) has the general formula AlR ⁸ _l X _3-l (where R ⁸ is an alkyl group having 1 to 12 carbon atoms, X is a halogen atom, represents 1 to 3), such as trimethylaluminum, triethylaluminum, tri-
n-propyl aluminum, tri-iso-butyl aluminum, tri-n-hexyl aluminum, diethylaluminum monochloride, di-
Iso-butylaluminum monochloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum monobromide, diethylaluminium monoiodide, diethylaluminium monofluoride, etc. are used singly or in combination of two or more. -3 Catalyst (C) component For component (C), any of the organic acid esters of component (iii) used in the preparation of the catalyst (A) component described above can be used, but particularly preferred are methyl benzoate,
Examples include ethyl benzoate, methyl p-toluate, ethyl p-toluate, methyl anisate, and ethyl anisate. The proportions of components (A), (B), and (C) used can vary over a wide range, but generally the molar ratio of component (B) to the titanium atoms in component (A) is in the range of 1 to 500. On the other hand, the amount of component (C) is 5 mol or less, preferably 0.01 to 1.5 mol, per 1 mol of the organoaluminum compound used as component (B). Polymerization method The method of the present invention uses the general formula R ⁹ −CH=CH ₂ (wherein R ⁹
represents an alkyl group having 1 to 10 carbon atoms), such as propylene, butene-
It can be used for homopolymerization of 1, hexene-1, 4-methyl-pentene-1, etc., and block or random copolymerization of the above α-olefin and ethylene. For the polymerization reaction according to the method of the present invention, methods and conditions conventionally used in the field of olefin polymerization technology can be employed. The polymerization temperature at that time is 20~
100℃, preferably in the range of 40 to 90℃, and the polymerization pressure is usually 1 to 100Kg/cm ² abs., preferably 1 to 90℃.
It is in the range of 50Kg/cm ² abs. In general, aliphatic, alicyclic, aromatic hydrocarbons or mixtures thereof can be used as a solvent in the polymerization reaction, such as propane, butane, pentane, hexane, heptane, cyclohexane, benzene, etc., and mixtures thereof. used. The polymerization can also be carried out by a bulk polymerization method using the liquid monomer itself as a solvent or by a so-called gas phase polymerization method in which a gaseous monomer and a catalyst are brought into contact with each other under substantially no solvent. The molecular weight of the polymer produced in the method of the present invention varies depending on the reaction mode, catalyst system, and polymerization conditions, but can be controlled by adding hydrogen, alkyl halides, dialkyl zinc, etc. as necessary. . Effects of the Invention According to the present invention, the amount of Mg compounds in the catalyst can be significantly reduced, and the amount of Mg compounds used per unit weight of α-olefin polymer can be significantly reduced by increasing the yield. Furthermore, by using a carrier in an appropriate particle form, a polymer having a high bulk density and excellent particle size characteristics can be obtained, and the productivity of the polymerization apparatus can be significantly improved. Examples of the present invention will be shown below. Example 1 (1) Preparation of solid catalyst component Silicon oxide (manufactured by Fuji Davison, grade
952, specific surface area 350 m ² /g, average pore size 200 Å, average particle size 54-65 μ, used after firing at 350°C for 3 hours in a nitrogen atmosphere, hereinafter referred to as SiO ₂ ○

Claims (1)

[Scope of Claims] 1 (A) (i) At least one metal oxide selected from oxides of elements of Groups 2 to 4 of the periodic table, or at least one of these metal oxides. (ii) general formula Mg(OR ¹ ) _i (OR ² ) _2-i (however, R ¹ , R ²
are the same or mutually different alkyl groups, aryl groups, i is a number indicating 0≦i≦2)
(ii) on the surface of the (i) component by contacting it with the magnesium compound represented by in an organic solvent.
A solid catalyst component obtained by reacting the solid content on which the component is deposited, (iii) an electron-donating compound, and () a tetravalent titanium compound having at least one halogen atom; (B) an organoaluminum compound; and (C) a method for polymerizing α-olefin, which comprises polymerizing α-olefin in the presence of a catalyst comprising an organic acid ester. 2 Magnesium compound Mg (OR ¹ ) (OR ² ) is once deposited on the (composite) oxide Mg (OR ³ ) (OR ⁴ )
(R ³ and R ⁴ are each a methyl group or an ethyl group) further reacted with R ⁵ OH (R ⁵ is an alkyl group or aryl group having 4 or more carbon atoms) at 40 to 100°C A method according to claim 1, characterized in that: