JPH0725822B2 - Process for producing olefin polymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an olefin polymer, and more specifically, it has a high polymerization activity of a catalyst and a small decrease in the polymerization activity with time, and can be obtained. The present invention relates to a method for producing an olefin polymer having high stereoregularity of the olefin polymer.

[Prior Art and Its Problems] Conventionally, an olefin polymer is produced by using a Ziegler-Natta catalyst in which a carrier obtained by partially halogenating dialkoxymagnesium is combined with a solid catalyst component supporting a titanium component. The method was known (Japanese Patent Publication No. 60-25441)
Issue).

However, although the above-mentioned catalyst has a high polymerization activity per unit time at the initial stage of the polymerization, it largely decreases with the passage of the polymerization time. Therefore, when a longer polymerization time is required, as in the case of block copolymerization reaction, it is a manufacturing disadvantage to use the above catalyst.

The present invention overcomes the above-mentioned conventional drawbacks, the polymerization activity of the catalyst is high, the decrease in the polymerization activity over time is small, the stereoregularity of the obtained olefin polymer is high, and the mixture of the catalyst residue is small. It aims at providing the manufacturing method of.

[Means for Solving the Problems] As a result of intensive studies conducted by the present inventors in order to achieve the above object, the present inventors have found that an olefin is present in the presence of a catalyst obtained from a specific solid catalyst component, an organoaluminum compound and an electron donating compound. It was found that the above-mentioned excellent effects can be obtained by polymerizing the above, and the present invention has been completed.

That is, the constitution of the present invention is as follows: a) dialkoxy magnesium; b) monoester of aromatic dicarboxylic acid and / or diester of aromatic dicarboxylic acid; and c) the following formula: Si (OR ¹ ) mX ¹ _4- m (In the formula, R ¹ is an alkyl group,
It represents a cycloalkyl group or an aryl group, X ¹ represents a halogen element such as chlorine or bromine, and m represents a real number between 0 and 3.0. ) A reaction product obtained by reacting with a silicon compound, d) a solid catalyst component (A) obtained by reacting titanium tetrahalide, (B) an organoaluminum compound, and (C) Production of an olefin polymer, characterized by polymerizing an olefin in the presence of a catalyst obtained from at least one selected from the group consisting of ethers, esters and an organic silane compound having a Si-O-C bond. Is the way.

Regarding the catalyst As shown in FIG. 1, the catalyst of the present invention is a reaction product obtained by reacting dialkoxy magnesium with a monoester of an aromatic dicarboxylic acid and / or a diester of an aromatic dicarboxylic acid with a silicon compound. , A solid catalyst component (A) obtained by reacting titanium tetrahalide, an organoaluminum compound (B), an ether, an ester, and an organosilane compound having a Si—O—C bond. And at least one type (C).

Solid catalyst component (A) Examples of the dialkoxy magnesium include diethoxy magnesium, dibutoxy magnesium, diphenoxy magnesium, dipropoxy magnesium, di-sec-butoxy magnesium, di-tert-butoxy magnesium and diisopropoxy magnesium. Can be mentioned.

In the present invention, one of the various dialkoxymagnesiums may be used alone, or two or more thereof may be used in combination.

Among the various dialkoxymagnesium, dialkoxymagnesium having an alkoxy group having 1 to 4 carbon atoms is preferable, and diethoxymagnesium and dipropoxymagnesium are particularly preferable.

The monoester of aromatic dicarboxylic acid and the diester of aromatic dicarboxylic acid are preferably monoesters of phthalic acid and diesters thereof, for example, monomethylphthalate, dimethylphthalate, monomethylterephthalate, dimethylterephthalate, monoethylphthalate,
Diethyl phthalate, monoethyl terephthalate, diethyl terephthalate, monopropyl phthalate, dipropyl phthalate, monopropyl terephthalate, dipropyl terephthalate, monobutyl phthalate, dibutyl phthalate, monobutyl terephthalate, dibutyl terephthalate, monoisobutyl phthalate, diisobutyl phthalate, monoamyl phthalate , Diamyl phthalate, monoisoamyl phthalate, diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate, ethyl propyl phthalate and the like.

In the present invention, either one of the various monoesters of aromatic dicarboxylic acids and the diester of aromatic dicarboxylic acids described above may be used alone, or two or more thereof may be used in combination.

When the monoester of the aromatic dicarboxylic acid and the diester of the aromatic dicarboxylic acid are compared, the diester of the aromatic dicarboxylic acid is preferable.

Among the diesters of aromatic dicarboxylic acids, lower alkyl esters of phthalic acid (provided that the lower alkyl group has 1 to 5 carbon atoms) are preferable, and dibutyl phthalate and diisobutyl phthalate are particularly preferable.

The silicon compound has the general formula: Si (OR ¹ ) mX ¹ _4- m (wherein R ¹ represents an alkyl group, a cycloalkyl group or an aryl group, and X ¹ represents a halogen atom such as chlorine or bromine). , M is a real number between 0 and 3.0).

Specific examples of the silicon compound include SiCl ₄ , CH ₃ OS
iCl ₃ , (CH ₃ O) ₂ SiCl ₂ , (CH ₃ O) ₃ SiCl, C ₂ H ₅ OSiCl ₃ ,
(C ₂ H ₅ O) ₂ SiCl ₂ , (C ₂ H ₅ O) ₃ SiCl, C ₃ H ₇ OSiCl ₃ , (C ₃ H
₇ O) ₂ SiCl ₂ , (C ₃ H ₇ O) ₃ SiCl, etc.,
These can be used alone or in combination.

Among them, silicon tetrachloride (SiCl ₄ ) is preferable.

Specific examples of the titanium tetrahalide include TiCl ₄ and TiB.
r ₄ , TiI _{4 and the} like, among which titanium tetrachloride (TiCl 4
₄ ) is preferred.

Preparation of Solid Catalyst Component (A) The solid catalyst component (A) is preferably prepared by the two-step operation described below.

That is, in the first step, the dialkoxymagnesium and the monoester of the aromatic dicarboxylic acid and / or the diester of the aromatic dicarboxylic acid and the silicon compound are treated in an inert solvent at a predetermined temperature and a predetermined time. And react with stirring.

In this case, as the usage ratio of each component, the usage amount of the monoester of the aromatic dicarboxylic acid and / or the diester of the aromatic dicarboxylic acid is usually 0.01 to 1 times mol, preferably 0.05 ~
It is 0.5 times the mole. The amount of the silicon compound used is usually 0.001 times or more mol, preferably 0.05 to 5 times mol, based on dialkoxymagnesium.

If the amount of the silicon compound used is less than 0.01 times the molar amount or too much, the polymerization activity of the catalyst will not be sufficiently improved, and the stereoregularity of the resulting olefin polymer will be insufficient.

The order of addition of each component is not particularly limited, and each component may be added sequentially or simultaneously.

The solvent may be one that is inactive with each component, and examples thereof include aliphatic hydrocarbons and alicyclic hydrocarbons, and specific examples include pentane, hexane, n-heptane, cyclohexane and the like. Can be mentioned.

Although the reaction using these solvents is a preferred embodiment of the present invention, it is also possible to carry out the reaction without a solvent. In this case, for example, the above components may be directly mechanically mixed by a ball mill or the like to react.

The reaction temperature is usually -10 to 150 ° C, preferably 20.
It is efficient to set the temperature to 120 ° C, and the polymerization activity of the obtained catalyst becomes high.

Further, the reaction time depends on the reaction temperature, and therefore may be appropriately selected according to the reaction temperature.

In the second step, the solid substance obtained in the first step is reacted with titanium tetrahalide after washing or without washing.

The second step of the process of the present invention is carried out in the order as described above, but the reaction is usually carried out in the liquid phase of the titanium tetrahalide compound or in an inert solvent such as pentane, hexane, n-heptane, cyclohexane. The temperature is 20 to 200 ° C., preferably 50 to 150 ° C., and the reaction time is 5 minutes to 10 hours, preferably 30 minutes to 5 hours.

The amount of titanium tetrahalide used is 1 to 100 times mol of magnesium in the first step, preferably 10 to 100.
It is twice the mole.

In the present invention, the solid product obtained by the reaction of the second step is washed with an inert hydrocarbon such as pentane, hexane, cyclohexane, n-heptane, if necessary, and the washed solid product is α- Used as a solid catalyst component (A) of an olefin polymerization catalyst.

The amount of the solid catalyst component (A) used is, for example, in the case of liquid phase polymerization, 0.001 to 10 mmo when the component (A) is converted to titanium atoms.
l /, preferably 0.005 to 5 mmol /.

Regarding Organoaluminum Compound (B) As the organoaluminum compound, trialkylaluminum compounds such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, and diethylaluminum monochloride, diisopropylaluminum monochloride, diisobutylaluminum. Dialkylaluminum monohalides such as monochloride, diisobutylaluminium monochloride, dioctylaluminium monochloride are suitable, and mixtures thereof can also be used.

In the present invention, one of the above various organoaluminum compounds may be used alone, or two or more thereof may be used in combination.

Among the above various organoaluminum compounds, trialkylaluminum having a lower alkyl group having 1 to 5 carbon atoms is preferable, and trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum and the like are particularly preferable.

The amount of the organoaluminum compound used is usually 1 to 1,000 (molar ratio), preferably 10 to 500 (molar ratio) in terms of titanium atoms in the solid catalyst component (A).

Regarding the electron donating compound (C) As the electron donating compound, at least one selected from the group consisting of ethers, esters, and organic silane compounds having a Si—O—C bond can be mentioned. Specifically, methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, ethyl butyrate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, croton. Ethyl acid, ethyl pivalate, dimethyl maleate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate,
Methyl toluate, ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, ethyl p-butoxybenzoate, ethyl o-chlorobenzoate, ethyl naphthoate, γ- Butyrolactone, δ-valerolactone, coumarin, phthalide, ethylene carbonate, di-n-butyl phthalate, di-iso-butyl phthalate, diheptyl phthalate,
C2-C18 esters such as dicyclohexyl phthalate; methyl ether, ethyl ether, isopropyl ether, t-butyl methyl ether, t-butyl ethyl ether, n-butyl ether, amyl ether, tetrahydrofuran, anisole, diphenyl ether,
2 to 20 carbon atoms such as ethylene glycol butyl ether
The ethers and the like can be exemplified.

Examples of the organosilicon compound having a Si—O—C bond include alkoxysilane and aryloxysilane.

Such examples include the general formula: R ² wSi (OR ³ ) _4- w (wherein R ² represents an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a haloalkyl group, an aminoalkyl group or a halogen atom. R ³ represents an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, or an alkoxyalkyl group, and w is 0 ≦ w ≦ 3.
However, w R ² and (4-w) OR ³ may be the same or different. ) Silicate ester represented by can be mentioned.

Other examples include siloxanes having an OR ³ group or silyl ester of carboxylic acid. further,
As another example, a silicon compound having no Si—O—C bond and an organosilicon compound having an O—C bond may be pre-reacted or may be reacted during the polymerization of α-olefin to produce Si—O—.
Examples thereof include those converted into an organosilicon compound having a C bond, and for example, a combination of SiCl ₄ and alcohol can be considered.

Specific examples of the organosilicon compound having a Si—O—C bond include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane,
Methylphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, γ- Aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriaryloxysilane, vinyllith (β-methoxyethoxy)
Examples include silane, vinyltriacetoxysilane, and dimethyltetraethoxydisiloxane.

Among the various electron-donating compounds (C), preferred are phthalic acid esters such as di-n-butyl phthalate, di-iso-butyl phthalate, diheptyl phthalate and dicyclohexyl phthalate, and t-butylmethyl. ether,
In combination with ether such as t-butyl ethyl ether,
Alkyl esters of aromatic carboxylic acids, for example, benzoic acid, p-methoxybenzoic acid, p-ethoxybenzoic acid, alkyl esters of aromatic carboxylic acids such as toluic acid having 1 to 4 carbon atoms, trialkoxysilane and the like are preferable, Aromatic ketones such as benzoquinone, aromatic carboxylic acid anhydrides such as benzoic anhydride, and ethers such as ethylene glycol butyl ether are also preferable.

The amount of the electron-donating compound (C) used is 1 to 500 (molar ratio), preferably 5 to 200 (molar ratio), with respect to the titanium atom of the solid catalyst component (A).

Olefin There is no particular limitation on the olefin that can be used in the method of the present invention, but in general, the general formula: R ⁴ —CH═CH ₂ (wherein R ⁴ represents hydrogen or an alkyl group having 1 to 6 carbon atoms) .), For example, linear monoolefins such as ethylene, propylene, butene-1, hexene-1, octene-1 and branched monoolefins such as 4-methylpentene-1.

These may be used alone or in combination of two or more kinds of olefins.

Among the above, ethylene and propylene are particularly preferable.

Also, in the method of the present invention, dienes such as butadiene and various other types can be used.

Production of Olefin Polymer In the present invention, in polymerizing an olefin, particularly an α-olefin, a dispersion liquid of a solid catalyst component which is the component (A) and an organoaluminum compound which is the component (B) are added to the reaction system. The olefin is introduced into this system by using the electron donating compound as the component (C) as a catalyst.

The polymerization method and conditions are not particularly limited, slurry polymerization with an inert hydrocarbon solvent, liquid phase polymerization without a solvent,
Both vapor phase polymerization and the like are possible, and both continuous and discontinuous polymerization are possible. Further, the polymerization reaction may be carried out in one stage or in multiple stages of two or more stages.

In a multi-stage polymerization reaction, for example, a two-stage polymerization reaction, usually, in the first stage, for example, a propylene polymerization reaction is carried out in the presence of the catalyst components (A), (B) and (C) to produce crystalline polypropylene, In the second stage, the catalyst component (A) is removed in the presence of the crystalline propylene with or without removing unreacted propylene used for the first stage polymerization.
It is a copolymer of ethylene and propylene in the presence of (B) and (C).

In the above reaction, the olefin pressure is normal pressure to 50 kg / cm ² , and the reaction temperature is 0 to 200 ° C., preferably 30 to 100 ° C.

The reaction time is 5 hours to 10 hours, preferably 30 minutes to 5 hours.

The molecular weight at the time of polymerization can be adjusted by a known means such as hydrogen.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 Preparation of solid catalyst component (A) 60 ml of dehydrated n-heptane in a 500 ml four-necked flask,
Charge 4.5 g of diethoxymagnesium and 1.2 ml of di-n-butyl phthalate, stir at room temperature, and then 1.5 ml of silicon tetrachloride.
Was added, the temperature was raised, and the mixture was reacted under reflux for 30 minutes.

To this, 100 ml of titanium tetrachloride was added, and the reaction was carried out at 110 ° C for 2 hours. Then, washing with n-heptane was carried out, 100 ml of titanium tetrachloride was further added, and the reaction was carried out at 110 ° C. for 2 hours, followed by thorough washing with n-heptane to obtain a solid catalyst component (A). Titanium content is 25 mg per 1 g of catalyst
And the amount of di-n-butyl phthalate per 1 g of the catalyst is 14
It was contained at a rate of 3 mg.

Production of olefin polymer n-heptane was added to the stainless steel autoclave of 1.
400 ml was added, and then 1 mmol of triisobutylaluminum as the component (B), 0.1 mmol of tert-butyl methyl ether as the component (C) and 0.088 mmol of dicyclohexyl phthalate, and 0.0025 mmol in terms of titanium atom.
The solid catalyst component (A) above is charged and the hydrogen pressure is 0.2 kg / c.
Polymerization was carried out at 70 ° C. for 2 hours while maintaining m ² and propylene pressure of 7.0 kg / cm ² . The yield of polypropylene is 1 g of titanium
It was 532 kg, and the boiling heptane extraction residue (II) was 97.8%.

(Example 2) In the production of the olefin polymer of Example 1, triethylaluminum was used in place of triisobutylaluminum, and 0.025 mmol of diphenyldimethoxysilane was used as the electron-donating compound (C) to carry out the same polymerization for 2 hours. I did. As a result, the yield of polypropylene is 1 g of titanium.
It was 723 kg per unit and II was 98.2%. When the polymerization time was set to 3 hours, the yield of polypropylene per 1 g of titanium was 932 kg and II was 98.0%.

(Example 3) Preparation of solid catalyst component A solid catalyst component was prepared in the same manner as in Example 1 except that diisobutyl phthalate was used instead of di-n-butyl phthalate. The content was 22 mg, and the diisobutylphthalate content per 1 g of the catalyst was 128 mg.

Production of Olefin Polymer Polymerization was carried out under the same conditions as in Example 2 to obtain 1 g of titanium.
The yield of polypropylene per unit is 685 kg, II is 97.
It was 9%.

(Comparative Example 1) Preparation of solid catalyst component A solid catalyst component was prepared in the same manner as in the preparation of the solid catalyst component of Example 1, except that 1.2 ml of ethyl benzoate was used instead of di-n-butyl phthalate. did. The titanium content per gram of catalyst was 32 mg and the ethyl benzoate content per gram of catalyst was 140 mg.

Production of Olefin Polymer In the production of the olefin polymer of Example 1, (C)
0.27 mmol of p-methyltoluate instead of the components tert-butyl methyl ether and dicyclohexyl phthalate
The same operation was carried out except that was used, and the polymerization was carried out for 2 hours. As a result, the yield of polypropylene was 212 kg per 1 g of titanium, and II was 96.5%. When the polymerization time is 3 hours, the yield of polypropylene per 1 g of titanium is
It weighed only 252 kg, and II fell to 94.8%.

(Example 4) A propylene-ethylene copolymer is produced using the solid catalyst component (A) obtained by the same operation as in the preparation of the solid catalyst component (A) of Example 1 as follows. It was

Production of Propylene-Ethylene Copolymer An autoclave having an internal volume of 5 was sufficiently replaced with nitrogen gas, and 20 g of dried polypropylene powder was added. Then, the triethylaluminum component (B)
2.0 mmol, component (C) triethoxyphenylsilane 0.1
The solid catalyst component (A), which was 0.1 mmol in terms of titanium atom, was charged into the autoclave. Hydrogen and propylene were introduced, and the temperature was elevated to 70 ° C. and pressure was increased to 20 kg / cm ² . The polymerization reaction was carried out for 2 hours under these conditions. The intrinsic viscosity [η] of the obtained propylene homopolymer was 1.2 dl / g.

After completion of the polymerization, degassing was once performed, and then a mixed gas of ethylene and propylene and hydrogen were introduced, and the pressure was adjusted to the mixed gas pressure.
While maintaining the rate at 18 kg / cm ² , the second stage polymerization reaction was carried out at 55 ° C. for 2 hours. The intrinsic viscosity [η] of the obtained propylene-ethylene copolymer was 4.0 dl / g, the ethylene content was 40% by weight, and the produced amount was 16% by weight.

After the completion of the polymerization, the unreacted gas was degassed to obtain a propylene polymer composition.

Predetermined additives were added to the obtained propylene polymer composition, and after mixing, granulation was performed with an extruder, and then test pieces were prepared, and the physical properties thereof were evaluated. The flexural modulus was 17,000 kg / cm ² , and the Izod impact strength was 3.0 kg · cm / cm (-20 ° C, notched).

(Example 5) Preparation of solid catalyst component In the preparation of the solid catalyst component of Example 1, the same adjustment was carried out except that 0.7 ml of diethyl phthalate was used in place of di-n-butyl phthalate. The titanium content was 23 mg, and the diethylphthalate content per 1 g of the catalyst was 102 mg.

Production of Olefin Polymer Polymerization was carried out under the same conditions as in Example 2. The yield of polypropylene was 689 kg per 1 g of titanium, and II was 9
It was 8.0%.

(Example 6) Butene-1 polymerization After autoclave having an internal volume of 5 was sufficiently replaced with nitrogen gas, 50 g of dried polybutene-1 powder was added. After that, 2.0 mmol of triisobutylaluminum,
0.5 mmol triethoxyphenylsilane, and Example 5
0.1 mmol in terms of titanium atom was added to the solid catalyst prepared in. Introduced hydrogen, nitrogen and butene-1, 55 ℃, 7k
The temperature and pressure were raised to g / cm ² . When polymerization was carried out for 3 hours under these conditions, polybutene-1 having an intrinsic viscosity [η] of 2.5 dl / g was obtained at a rate of 250 kg per 1 g of titanium. The mm fraction in C ¹³ NMR analysis was 95.8%.

[Effects of the Invention] As described above, according to the production method of the present invention, the polymerization activity of the catalyst is high and the olefin polymer can be efficiently obtained without the polymerization activity decreasing with time. Therefore, the catalyst removing step and the polymer washing step can be simplified or omitted. Further, the obtained olefin polymer has various stereo-regularity and various advantages such as little mixing of catalyst residue.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a procedure for preparing a catalyst in the present invention.

Claims (1)

[Claims] 1. A) dialkoxymagnesium, b) a monoester of an aromatic dicarboxylic acid and / or a diester of an aromatic dicarboxylic acid, and c) the following formula: Si (OR ¹ ) mX ¹ _4- m (wherein , R ¹ represents an alkyl group, a cycloalkyl group, or an aryl group, X ¹ represents a halogen atom such as chlorine or bromine, and m represents a real number between 0 and 3.0). (A) which is obtained by reacting a reaction product obtained by reacting
In the presence of a catalyst obtained from a solid catalyst component, (B) an organoaluminum compound, and (C) at least one selected from the group consisting of ethers, esters, and organosilane compounds having a Si—O—C bond. And a method for producing an olefin polymer, which comprises polymerizing an olefin.