JPS5922909A - Polymerization of ethylene - Google Patents

Abstract

PURPOSE:To obtain a high-bulk density polyolefin in high yield, using a catalyst prepared by incorporating an organoaluminum compound in a solid made by bringing a specific titanium compound into contact-with a carrier obtained by the reaction between a Grignard compound and a reactant derived from an aluminum halide and a specific silicon compound. CONSTITUTION:The objective polymer can be obtained by carrying out a polymerization of ethylene or copolymerization between ethylene and a >=3C alpha- olefin, in the presence of a catalyst consisting of (A) a solid catalytic component made by bringing a titanium compound of formula II (R<4> is R<1>, X<2> is halogen; m is 0, 1, 2, or 3) into contact with a carrier prepared by the reaction between a Grignard compound by formula R<3>MgX<1> (R<3> is R<1>; X<1> is halogen) and a reactant derived from an ammonium halide and a silicon compound of formula I (R<1> and R<2> are each 1-8C alkyl, phenyl or 7-10C aralkyl; l is 0, 1, 2, or 3), and (B) an aluminum compound of formula III (R<5> is 1-6C alkyl; n is 1 or 2).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for polymerizing ethylene or a mixture of ethylene and an α-olefin having more than 1 carbon atoms in the presence of a highly active Ziegler type catalyst.

The applicant prepares a support by reacting a reaction product of aluminum halide and tetraalkoxysilane with a Grignard compound, and the solid catalyst component obtained by contacting the support with titanium tetrahalide and trialkyl We have already proposed a method for polymerizing ethylene in the presence of a catalyst obtained from aluminum (Japanese Patent Laid-Open No. 56-4590).
(See Publication No. 9).

The present invention is an improvement on the above-mentioned proposed method, and provides a method for polymerizing ethylene with a higher polymer yield per solid catalyst component.

In other words, the present invention is as follows.

(1) Aluminum halide.

Formula R'zsi(oR2)4-t (wherein, R1 and R2 each have 1 to 1 carbon atoms
The alkyl group or phenyl group of 8 represents an aralkyl group having 7 to 10 carbon atoms, and t is 0, 1.2 or O. )
React with a silicon compound represented by

(2) A carrier is prepared by reacting the reaction product with a Grignard compound represented by the formula R3MgX+ (wherein R3 has the same meaning as R1, and XI represents a halogen atom).

(3) The carrier has the formula (R' O) m T iX 24,, -m(
In the formula, R4 has the same meaning as R1, X2 represents a halogen atom, and 9m is 0, 1.2 or 6. ), and a solid catalyst component (A) obtained by contacting with a titanium compound represented by the formula R5n AZ R3-n (wherein R5 represents an alkyl group having 1 to 2 carbon atoms).

n is 1 but not 2. This is a method for polymerizing ethylene, which is characterized by polymerizing ethylene, or a mixture of ethylene and an α-olefin having 6 or more carbon atoms, in the presence of a catalyst obtained from an aluminum compound (B) represented by (B).

According to the invention, ethylene polymers are obtained in significantly higher yields per solid catalyst component. For example, ethylene partial pressure 7
Kg/crA, when ethylene is polymerized for 1 hour at a polymerization temperature of 90°C, the yield of polyethylene per 17 solid catalyst components reaches about 14oKp.

According to the present invention, an ethylene polymer having a high bulk density can be obtained.

In the present invention, the preparation of the solid catalyst component is carried out using substantially anhydrous compounds under an inert gas atmosphere such as nitrogen or argon.

Specific examples of aluminum halides include aluminum chloride, aluminum bromide, and aluminum iodide, among which aluminum chloride is preferably used.

Specific examples of silicon compounds include:

Tetramethoxysilane, tetraethoxysilane.

Tetrabutoxinelan, tetrapentoxysilane.

Methyltrimethoxysilane, Methyltrinidoxinrane, Methyltri-n-butoxysilane, Methyl-lisopentoxysilane, Methyltri-n-hexoxysilane, Methyltriisooctoxysilane, Ethyltriethoxysilane, Ethyltri Isoproboquinone, ethyltriisopentoxy7, n-butyltriethoxysilane, isobutyltrinidoxin, isopentyltriethoxysilane, isopentialethoxysilane, dimethyljethoxysilane, dimethyldi-n-butoxysilane , dimethyldiimpentoquine/ran, diethyldiethquinsilane, diethyldiisope/toki/ranan, di-n-butyldiethoxo7rane, diisobutyldiisopentoxysilane.

Trimethylmethoxysilane, trimethylethoxysilane, trimethylisobutoxysilane, triethylisopropoxysilane, tri-n-butylethoxysilane, tri-n-butylethoxysilane, t+)isopentylethoxysilane, phenyltriethoxysilane, phenyltriiso Butoxysilane, phenyltriynepentoxysilane, diphenyljethoxysilane, diphenyldiisopentoxysilane, diphenyldioctoxy 7ran.

Triphenylmethoxysilane, triphenylethoxysilane, triphenylisopentoxysilane.

Trimethylphenoxysilane, triethylphenoxysilane, dimethyldiphenoxysilane, benzyltriethoxysilane, dibenzyljethoxysilane, methyltris(benzyloxy)silane.

Examples include.

What is the proportion of aluminum chloride used in the reaction?

0.25 to 10 mol per mol of silicon compound, especially 0
．． The amount is preferably 5 to 2 moles.

The reaction between aluminum halide and a silicon compound is usually carried out by combining both compounds in an inert organic solvent.

This is carried out by stirring for 0.1 to 2 hours at a temperature in the range -50 to 100°C. The reaction proceeds exothermically and the two reaction products are obtained as a solution in an inert organic solvent. The reaction product can be subjected to the reaction with the Grignard compound as the above solution without being isolated. Among Grignard compounds, alkylmagnesium chlorides in which X is a chlorine atom are preferably used, and specific examples include methylmagnesium chloride, ethylmagnesium chloride, n-butylmagnesium chloride,
-hexylmagnesium chloride, phenylmagnesium chloride, benzylmagnesium chloride and the like.

The amount of the Grignard compound used is 0.05 to 4 mol, p per 1 mol of the silicon compound used for the preparation of the reaction product.
In particular, it is preferably 1.5 to 2 mol.

There are no particular restrictions on the method of reacting the reaction product with the Grignard compound, but one method is to gradually add an ether solution of the Grignard compound or a mixed solvent solution of ether and an aromatic hydrocarbon to a solution of the reaction product in an inert organic solvent. Conveniently this is done by addition or addition in the reverse order. As for the ether above.

A compound represented by the formula R6-0-R7 (wherein R6 and W represent an alkyl group having 2 to 8 carbon atoms) is preferably used.

Specific examples thereof include diethyl ether, diisopropyl ether, di-n-butyl ether, and diisoamyl ether.

The reaction temperature is usually -50 to 100°C9, preferably -20°C
~25°C. There is no particular restriction on the reaction time, but it is usually 5 minutes or more. As the reaction progresses, the carrier precipitates out. Although the carrier obtained in this way can be subjected to the next treatment as a reaction mixture, it is preferable to separate the carrier in advance, wash it with an inert organic solvent, and then subject it to the reaction with the titanium compound.

A specific example of a titanium compound is titanium tetrachloride.

Titanium tetrabromide, titanium tetraiodide, methoxytrichlortitanium, dimethoxydichlorotitanium, trimethoxydichlortitanium, ethoxytrichlortitanium.

Jetoxydichlortitanium, propoxytrichlortitanium, dipropoxydichlortitanium, butoxytrichlortitanium, dibutoxydichlortitanium.

Phenoxytrichlortitanium, diphenoxydichlortitanium, methoxytribromotitanium, phenoxytribromotitanium, methoxytriiodotitanium, phenoxytriiodotitanium, benzyloxytrichlortitanium, bis(benzyloxy)dichlortitanium, l-s(benzyloxy)chlor Examples include titanium, benzyloxytribromotitanium, benzyloxytriiodotitanium, and the like.

The amount of phosphatide used is 1 mol or more per 1 mol of the Grignard compound used in preparing the carrier.

In particular, it is preferably 2 to 100 moles.

The carrier and the titanium compound can be brought into contact in the presence or absence of an inert organic solvent.

The temperature during contact is 20 to 200°C, especially 60 to
Preferably it is 140°C. The contact time is not particularly limited, but is usually 0.5 to 3 hours. This contact treatment with a titanium compound can be performed one or more times. In the present invention, the solid catalyst component obtained by performing the contact treatment twice exhibits the highest ethylene polymerization activity.

The solid catalyst component is separated from the mixture containing the solid catalyst component thus obtained by filtration, decanting, etc.

Wash with inert organic solvent. The solid catalyst component contains titanium in an amount of 0.5 to 10% by weight.

Inert organic solvents used in each step of preparing the solid catalyst component include aliphatic hydrocarbons such as hexane and heptane;
Aromatic hydrocarbons such as toluene, benzene, xylene,
Examples include halides of these hydrocarbons.

In the present invention, ethylene or a mixture of ethylene and an α-olefin having 6 or more carbon atoms is polymerized in the presence of a catalyst obtained from a solid catalyst component and an aluminum compound.

Specific examples of the aluminum compound include diethyl aluminum hydride, diisobutyl aluminum hydride, dihexyl aluminum hydride, . . . hydride, and the like. The amount of aluminum compound used is usually 1 to 1,000 per 1 gram atom of titanium in the solid catalyst component.
It is a mole.

The polymerization reaction of ethylene can be carried out by a medium-low pressure method or a high-pressure method, and the polymerization by a medium-low pressure method can be carried out in a liquid phase or a gas phase.

When carrying out a polymerization reaction in a liquid phase, one polymerization solvent is used, for example, n-butane, n-propa-7, n-hexane, n-
Aliphatic hydrocarbons such as heptane.

Alicyclic hydrocarbons such as 7 chlorohexane and cyclopentane, and aromatic hydrocarbons such as benzene and toluene are used. There are no particular restrictions on the catalyst concentration in the polymerization solvent, but in general, it is 0.0005 to 10 milligrams of titanium metal equivalent per 1 polymerization solvent for solid catalyst components, and 0.0005 to 10 milligram atoms per 1 polymerization solvent for organoaluminum compounds. 0.0'01 to 1,000 mmol.

In the present invention, not only ethylene is polymerized alone, but also ethylene and α-olefin having 6 or more carbon atoms, such as propylene and 1-butene.

4-methyl-1-pentene and 1-hexene can be copolymerized.

In the present invention, the 1-polymerization reaction is carried out in a state in which water and oxygen are substantially excluded, as is the case with the ordinary polymerization reaction of ethylene using a Ziegler type catalyst.

The polymerization temperature is usually 60 DEG to 300 DEG C., and the polymerization pressure is usually 1 to 6,000 C/crA.

In this invention, the molecular weight of the ethylene polymer obtained can be easily adjusted by adding hydrogen to the monopolymerization system.

Next, examples will be shown. In the description below.

"Polymerization activity" means 1 solid catalyst component used in polymerization reaction 1
9 per 1 Polymer yield (Kq) per hour of polymerization time -?
? Yes, "M, Engineering" is according to ASTM D1238,
2.1 bKq/melt flow index measured at 190°C under shoulder load. In an example,
All solid catalyst components were prepared in a dry nitrogen gas atmosphere.

Example 1 (1) Preparation of solid catalyst component 2.0 fi' of anhydrous aluminum chloride and 60 m of toluene
1, and while stirring add phenyltriethoxysilane '5.
After dropping 13.5 ml of a toluene solution containing 50 ml over 50 minutes at 25°C, the temperature was raised to 60°C, and the temperature was then maintained for 1 hour for reaction.

The reaction product mixture was cooled to -11 to -7°C, and while stirring, 16.8 m6 of diisoamyl ether containing 27 mmol of n-butylmagnesium chloride was added dropwise to the reaction product mixture over 45 minutes. The temperature was raised to 1, and the temperature was maintained for 60 minutes for reaction.

The precipitated carrier was separated and washed six times with toluene and 30 WLe each.

The carrier was suspended in 30rnl of toluene, and 15.0ml of titanium tetrachloride was added to this suspension. Add OmJ and incubate at 90°C under stirring for 6
The solid was contacted with titanium tetrachloride for 0 minutes.

At the same temperature, separate the treated carrier and add 6 oral of toluene to 5
It was then washed five times with 30 ml each of n-hebutane.

80 g of n-hebutane was added to the obtained solid catalyst component (titanium content: 5.92% by weight) to prepare a slurry of the solid catalyst component.

(2) Polymerization After attaching a glass ampoule containing a suspension of a solid catalyst component (4.0 μm as a solid catalyst component) to an autoclave with an internal volume of 2 tons and equipped with a polymerization stirrer, the air in the autoclave was replaced with nitrogen. .

1 t of n-hexane was introduced into the autoclave, followed by 1.2 ml of n-hexane containing 222 moles of diisobutylaluminum hydride per gram atom of titanium in the solid catalyst component, and the autoclave contents were heated to 90°C. The internal pressure (gauge pressure, same hereinafter) of the autoclave at this time was 0.9 Ky/J.

The total pressure of ethylene is 7. After introducing into the autoclave until qKy/crA was reached, stirring was started to crush the glass ampoule, and ethylene was polymerized at 90°C for 60 minutes.

During polymerization, ethylene was continuously supplied, and the total pressure was 7°9 Kf.
/c7A.

After the polymerization reaction was completed, unreacted ethylene was released, and the polymer was separated and dried under reduced pressure at +SO'C for 20 hours.

White polyethylene 4201 was obtained. Polymerization activity is 125
, the density was 0.9511/crA, and the bulk specific gravity was 0.37.

Example 2 and Filter Example 1 was repeated except that diisobutylaluminum hydride was used in the amount of moles listed in Table 1 per gram atom of titanium in the solid catalyst component. Results first
Shown in the table.

Table 1 Examples 4-6 The amount of diisobutylaluminum hydride used was varied to 9200 moles per gram atom of titanium in the solid catalyst component, and prior to the introduction of ethylene, hydrogen was autoclaved to the pressures listed in Table 2. Example 1 was repeated, except that

The results are shown in Table 2.

Table 2 Examples 7-10 Example 1 was repeated, except that 15 mmol of the silicon compound listed in Table 6 was used instead of phenyltriethoxysilane. Table 6 shows the titanium content of the solid catalyst component and the polymerization results.

Examples 11 and 12 Example 1 was repeated, except that the titanium compounds listed in Table 4 were used instead of titanium tetrachloride. Table 4 shows the titanium content of the solid catalyst component and the polymerization results.

□ Example 1! I Solid catalyst component 3.431i obtained in Example 1-(1)
' was suspended in Oml of toluene, 15 mg of titanium tetrachloride was added under stirring, and the mixture was reacted at 90°C for 1 hour.

The solid was filtered once at the same temperature and washed five times with 30 mJ of n-hebutane each time to obtain a solid catalyst component with a titanium content of 5.51% by weight. Add n-hebutane son/! was added to make a slurry.

Ethylene was polymerized in the same manner as in Example 1-(2) using 3.6~ of this solid catalyst component.The polymerization activity was 140, and the bulk density of the produced polyethylene was 0.3 sr/J.

Example 14 Example 1-(
After installing the Galanoa

The air in the autoclave was replaced with nitrogen.

0.660 mmol of diisobutylaluminum rhamnohydride in n-hebutane 1. OmL Hydrogen was then introduced into the autoclave until the hydrogen pressure reached 5Kq/-. Liquid 1-butene 2007+n-butane 1000rtt
1 was pressurized into the autoclave, and the autoclave contents were heated to 66°C. The pressure of the autoclave at this time was 910A at 17.7.

Ethylene was introduced into the autoclave until the total pressure reached 28/-, stirring was started, the glass ampoule was crushed, and ethylene and 1-butene were copolymerized at 66°C for 60 minutes. During the polymerization, ethylene was continuously fed to maintain the total pressure at 28 kg/-.

After the polymerization reaction is completed, unreacted monomers and n-butane are released to form a white ethylene-butene-1 copolymer 24.
5.5 ii' was obtained.

The density of the copolymer is 0.9257/d, M, Ia2.
4g/10min, bulk density is 0.36 y/a? r and 2
Polymerization activity was 98.2.

Patent applicant Ube Industries Co., Ltd.

Claims (3)

[Claims] (1) Aluminum halide. 2 R'Z Si(OR") 4-1 (wherein R1 and R2 each represent an alkyl group having 1 to 8 carbon atoms, a phenyl group, or an aralkyl group having 7 to 10 carbon atoms, t is 0, 1.2 or ro). (2) A carrier is prepared by reacting the reaction product with a Grignard compound represented by R3M9XI (wherein R3 has the same meaning as R1 and XI represents a halogen atom). (3) The carrier has the formula (R40)mTiX24. , :m (in the formula,
R4 has the same meaning as R1, X2 represents a halogen atom, and 9m is 0.1.27 digits. ) A solid catalyst component obtained by contacting with a titanium compound (A
), and a catalyst obtained from an aluminum compound (B) represented by the formula R5nAtH3-n (wherein R5 represents an alkyl group having 1 to 6 carbon atoms, and n is 1 or 2). A method for polymerizing ethylene, which comprises polymerizing ethylene or a mixture of ethylene and an α-olefin having 6 or more carbon atoms.