JPH0725823B2 - Method for producing olefin polymer - Google Patents

Description

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

[Prior Art] Conventionally, there is known a method of producing an olefin polymer using a Ziegler-Natta catalyst in which a carrier obtained by partially halogenating dialkoxymagnesium is combined with a solid catalyst component carrying a titanium component. It was (Tokuboku Sho 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, it is a manufacturing disadvantage to use the above catalyst.

The present invention is a process for producing an olefin polymer which has a high polymerization activity of a catalyst which overcomes the above-mentioned conventional drawbacks, has a small decrease in the polymerization activity, has a high stereoregularity of the obtained olefin polymer, and is less contaminated with a catalyst residue. The purpose is to provide.

[Means for Solving 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 in the presence of a catalyst obtained from a specific solid catalyst component, an organoaluminum compound, and a specific electron-donating compound. It was found that the above-mentioned excellent effects can be obtained by polymerizing the olefin with the above, and thus 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 atom such as chlorine or bromine, and m is a real number between 0 and 3.0. ) A silicon compound represented by), d) a reaction product obtained by reacting an alcohol, and e) a titanium tetrahalide obtained by reacting (A) a solid catalyst component, and (B) an organoaluminum. Polymerizing an olefin in the presence of a catalyst obtained from a compound and (C) an ester, an ether, and at least one electron-donating compound selected from the group consisting of organosilane compounds having a Si—O—C bond. And a method for producing an olefin polymer.

Regarding the catalyst In the present invention, the catalyst is a reaction product obtained by reacting a monoester of dialkoxymagnesium and an aromatic dicarboxylic acid and / or a diester of an aromatic dicarboxylic acid with a silicon compound and an alcohol, and a tetrahalogenation compound. Solid catalyst component (A) obtained by reacting with titanium
And an organoaluminum (B) and a specific electron donating compound (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,
Of these, diethoxy magnesium and dipropoxy magnesium are preferable.

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

As the monoester of aromatic dicarboxylic acid and the diester of aromatic dicarboxylic acid, mono and diesters of phthalic acid are preferable, for example, monomethyl phthalate, dimethyl phthalate, monomethyl terephthalate,
Dimethyl terephthalate, monoethyl phthalate, 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,
Examples thereof include ethyl butyl phthalate, ethyl isobutyl phthalate and ethyl propyl phthalate.

In the present invention, any one of the above various monoesters of aromatic dicarboxylic acids and diesters of aromatic dicarboxylic acids may be used alone, or any 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 above 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 is represented by the general formula: Si (OR ¹ ) mX ¹ _4- m (wherein R ¹ represents an alkyl group, a cycloalkyl group, or an aryl group, X ¹ is a halogen atom such as chlorine or bromine,
m represents a real number between 0 and 3.0. ), Specifically, SiCl ₄ , CH ₃ OSiCl 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 S
Examples thereof include iCl, and these can be used alone or as a mixture. Among the above, silicon tetrachloride (SiCl ₄ ) is preferable.

The above alcohols are not particularly limited, but usually, the general formula: R
² OH (In the formula, R ² is an alkyl group or a cycloalkyl group having a linear or side chain having 1 to 10 carbon atoms. Specific examples of this alcohol include methanol, ethanol, propanol, isopropanol, Butanol, isobutanol, amyl alcohol, octanol, cyclohexanol and the like can be mentioned, and among them, isopropanol is preferable.

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

The solid catalyst component (A) is prepared by a two-step operation. First, in the first step, the dialkoxymagnesium and mono- or diester of aromatic dicarboxylic acid, silicon compound and alcohol are inactive. The mixture is added to a solvent, and a catalytic reaction is performed while stirring at a predetermined temperature and time.

In this case, as the usage ratio of each component, the amount of the monoester of aromatic dicarboxylic acid and / or the diester of aromatic dicarboxylic acid used is usually 0.01 to 1 times mol, preferably 0.05 to 1 mol, based on dialkoxymagnesium. 0.5
The amount of alcohol used is 0.01 times or more, preferably 0.05 to 2 times.

When the amount of the silicon compound used is less than 0.01 times the molar amount and too much, the polymerization activity of the catalyst is insufficient and the stereoregularity of the obtained olefin polymer becomes insufficient.

When the amount of the above alcohols used is less than 0.01 times the molar amount and too much, the polymerization activity of the catalyst is insufficient and the stereoregularity of the obtained olefin polymer is insufficient.

The order of adding the above components is not particularly limited and can be appropriately selected.

The solvent used in the above reaction may be one that is inert to each component, and examples thereof include various solvents such as aliphatic hydrocarbons and alicyclic hydrocarbons. Specifically, pentane, hexane, Examples include n-heptane and cyclohexane.

The reaction using the above solvent is a preferred embodiment of the present invention, but it can also be carried out in the absence of a solvent. In this case, for example, the above components may be directly mechanically mixed and reacted by a ball mill or the like.

The reaction is usually efficient at -10 to 150 ° C, preferably 20 to 120 ° C, and the polymerization activity of the resulting catalyst is high. Further, the reaction time depends on the reaction temperature and may be appropriately selected.

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, preferably 10 to 100 times mol, per 1 gram atom of magnesium in the first step.

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) Examples of the organoaluminum compound include 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.

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 specific electron donating compound (C) The specific electron donating compound (C) is an ester,
It is at least one electron-donating compound selected from the group consisting of ethers and organic silane compounds having a Si-O-C bond.

Examples of the esters include 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, ethyl crotonic 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-phthalate.
C2-C18 such as n-butyl, di-iso-butyl phthalate, diheptyl phthalate, dicyclohexyl phthalate
The esters can be exemplified.

Examples of the ethers include methyl ether, ethyl ether, isopropyl ether, t-butyl methyl ether, t-butyl ethyl ether, n-butyl ether,
Examples thereof include C 2-20 ethers such as amyl ether, tetrahydrofuran, anisole, diphenyl ether, and ethylene glycol butyl ether.

Examples of the organic silane compound having a Si—O—C bond include alkoxysilane and aryloxysilane. An example of this is the general formula: R ³ wSi
(OR ⁴ ) _4- w (In the formula, R ³ represents an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a haloalkyl group, an aminoalkyl group or a halogen atom, and R ⁴ represents an alkyl group, a cycloalkyl group, an aryl group. Group, alkenyl group,
Alternatively, it represents an alkoxyalkyl group. Also, w is 0 ≦ w
≦ 3. However, w R ³ and (4-w) OR ⁴ may be the same or different. )
The silicic acid ester represented by Other examples include siloxanes having an OR ⁴ group or silyl esters of carboxylic acids. Furthermore, 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 form a Si—O—C bond. Examples thereof include those converted into an organic silane compound having a. For example, it is possible to use SiCl ₄ in combination with alcohol.

Specific examples of the organic silane 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, silicic acid Butyl, trimethylphenoxysilane, methyltriaryloxysilane, vinyl tris (β-methoxyethoxy)
Examples include silane, vinyltriacetoxysilane, and dimethyltetraethoxydisiloxane.

The various specific electron-donating compounds (C) may be used alone or in combination of two or more. In particular, di-n-butyl phthalate, di-phthalate
A combination of phthalic acid esters such as iso-butyl, diheptyl phthalate and dicyclohexyl phthalate with ethers such as t-butyl methyl ether and t-butyl ethyl ether, alkyl esters of aromatic carboxylic acids such as benzoic acid, p -Methoxybenzoic acid, p-ethoxybenzoic acid, C1-4 alkyl esters of aromatic carboxylic acids such as toluic acid, trialkoxysilanes and the like are preferable, and ethers such as ethylene glycol butyl ether and the like are also preferable.

The specific electron-donating compound (C) is used in an amount of 1 to 500 (molar ratio), preferably 5 to 200 (molar ratio), based on the titanium atoms of the solid catalyst component (A).

Olefin The olefin that can be used in the method of the present invention is not particularly limited, but is generally represented by the general formula: R ⁵ —CH═CH ₂ (R ⁵ represents hydrogen or an alkyl group having 1 to 6 carbon atoms). And 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 as a mixture, and among them, 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. , Olefin is introduced into this system using the specific 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 such as a two-stage polymerization reaction, usually, for example, propylene is produced in the presence of the catalyst components (A), (B) and (C) in the first stage, and in the second stage, the first stage is used. In the present invention, ethylene and propylene are copolymerized in the presence of the crystalline propylene with or without removing unreacted propylene that has been polymerized.

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 minutes 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) 75 ml of dehydrated n-heptane in a 500 ml four-necked flask,
3.7 g of diethoxymagnesium and 1.2 ml of silicon tetrachloride were charged, a solution of 1.0 ml of isopropanol and 5 ml of n-heptane was added dropwise at room temperature for 1 hour, the temperature was raised, and the mixture was stirred under reflux for 1 hour. Then di-n-butyl phthalate
1.0 ml was added, 90 ml of titanium tetrachloride was added, and the reaction was carried out at 110 ° C. for 2 hours. The solid catalyst component (A) was obtained by washing with n-heptane, adding 90 ml of titanium tetrachloride, reacting at 110 ° C. for 2 hours, and sufficiently washing with n-heptane. The titanium content is 22 mg per gram of catalyst and the di-n-butyl phthalate is 150 mg per gram of catalyst.
It was contained in the ratio of.

Production of olefin polymer n-heptane was added to the stainless steel autoclave of 1.
Add 400 ml, then triisobutylaluminum 1 mm
ol, tert-butyl methyl ether 0.1 mmol, dicyclohexyl phthalate 0.088 mmol and 0.0025 mmol of the above solid catalyst component in terms of titanium atom, and hydrogen pressure 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 582 kg per 1 g of titanium, and the boiling heptane extraction residue (II) is 97.2%.
Met. Further, when the polymerization time was set to 3 hours, the yield of polypropylene per 1 g of titanium was 718 kg.
Was 97.1%.

(Example 2) In the production of the olefin polymer of Example 1, triethylaluminum was used instead of triisobutylaluminum, and similar polymerization was carried out using 0.025 mmol of diphenyldimethoxysilane as an electron-donating compound. As a result, the yield of polypropylene was 785 kg per g of titanium, 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 catalyst was 128 mg.

Production of Olefin Polymer Polymerization was carried out under the same conditions as in Example 2. The yield of polypropylene was 685 kg per 1 g of titanium, and II was 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 1.0 ml of ethyl benzoate was used instead of dibutyl phthalate. 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, tert-
The same operation was repeated except that 0.27 mmol of p-methyltoluate was used instead of butyl methyl ether and dicyclohexyl phthalate, and the polymerization was carried out for 2 hours. As a result, the yield of polypropylene was 242 kg per 1 g of titanium, and II was 96.9%.
Met. Further, when the polymerization time was set to 3 hours, the yield of polypropylene per 1 g of titanium was 293 kg.
I. was 95.0%.

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

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. After that, triethylaluminum 2.0 mmol, diphenyldimethoxysilane 0.1 mmol, solid catalyst component 0.1 mmol T
i atoms were charged into this 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 [η] of the obtained propylene homopolymer was 1.3 dl / g.

After completion of the polymerization, after degassing once, a mixed gas of ethylene and propylene and hydrogen were introduced, and the pressure was adjusted to a mixed gas pressure of 18 kg / c.
The second stage polymerization reaction was carried out at 55 ° C. for 2 hours while maintaining m ² . [Η] of the obtained propylene-ethylene copolymer was 4.0 dl / g, the ethylene content was 37% by weight, and the produced amount was 15% 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. Flexural modulus is 16,700 kg / c
The m ² and Izod impact strength were 3.2 kg · cm / cm (−20 ° C., notched).

(Example 5) Adjustment of solid catalyst component In the adjustment of the solid catalyst component of Example 1, the same adjustment was carried out except that 0.58 ml of diethyl phthalate was used in place of di-n-butyl phthalate. Had a titanium content of 25 mg, and the diethylphthalate content per 1 g of the catalyst was 98 mg.

Production of Olefin Polymer Polymerization was carried out under the same conditions as in Example 2. The yield of polypropylene was 720 kg per 1 g of titanium, and II was 9
It was 7.6%.

[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 a flow chart for preparing the Ziegler type catalyst used 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 is an alkyl group,
It represents a cycloalkyl group or an aryl group, X ¹ represents a halogen atom such as chlorine or bromine, and m is a real number between 0 and 3.0. ) A silicon compound represented by), d) a reaction product obtained by reacting an alcohol, and e) a titanium tetrahalide obtained by reacting (A) a solid catalyst component, and (B) an organoaluminum. Polymerizing an olefin in the presence of a catalyst obtained from a compound and (C) an ester, an ether, and at least one electron-donating compound selected from the group consisting of organosilane compounds having a Si—O—C bond. A method for producing an olefin polymer, comprising: