JPH03290409A - Polymerization of ethylene - Google Patents

Abstract

PURPOSE:To obtain an ethylene polymer without causing activity dropoff and coloration by polymerization at high-temperatures and pressures of ethylene or its mixture with an alpha-olefin using a catalyst made from an Al compound, organosilicon compound, Ti compound, Grignard reagent and organoaluminum compound. CONSTITUTION:The objective polymer can be obtained by polymerization at >=125 deg.C under a pressure of >=200kg/cm<2> of ethylene or its mixture with a >=3C alpha-olefin using a catalytic system made up of (A) a solid catalytic component prepared by reaction of (1) a Grignard reagent of formula III (R<3> is 1-8C alkyl; X<2> is halogen) with a reaction product from (2) an aluminum halide of formula l (X<1> is chlorine, bromine, etc.) and (3) an organosilicon compound of formula II (R<1> and R<2> are each 1-8C alkyl or phenyl; n is 0-3) and bringing a titanium halide into contact with the resulting solid, (B) an organoaluminum compound of formula IV (R<4> is 2-6C alkyl; X<3> is halogen; m is 1-3), and (C) the component (3).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for polymerizing ethylene or copolymerizing ethylene and an α-olefin having 3 or more carbon atoms under high temperature and high pressure.

[Prior art and its problems] Until now, ethylene has been polymerized in the presence of a Ziegler type catalyst at a temperature of 125°C or higher and a pressure of 200kg/c+f1 or higher, or ethylene and an α-olefin having 3 or more carbon atoms have been co-polymerized. Various methods of polymerization have been proposed.

For example, a catalyst consisting of a combination of a titanium compound supported on titanium trichloride or a magnesium compound and an organic aluminum has been proposed (JP-A-4997087, JP-A No. 56-18607, JP-A No. 57-190009, JP-A No. 59
-58012, 59-89306).

In the above polymerization method, the cocatalyst is usually halogen-containing organoaluminium, such as diethylaluminum monochloride, dibutylalgonium monochloride, or Ethylaluminum sesquichloride and the like are used.

Using the above proposed catalyst system, ethylene and α-olefin are copolymerized under high temperature and pressure, resulting in linear low density polyethylene (L) with a relatively large melt viscosity index (MFR).
However, it is not always easy to produce LLDPE with a relatively small MFH. In particular, in the production of very low density polyethylene (VLDPE) with a high content of α-olefins having 3 or more carbon atoms, it is difficult to obtain polymers with a small MFR when using the catalyst systems proposed so far. is extremely difficult.

In order to solve these problems, methods have been proposed in which various electron donors are added to the catalyst system.

For example, tertiary alcohols (JP-A-63-317503), ethers, ketones, esters (JP-A-62-317503), ethers, ketones, esters (JP-A-62-317503)
109805), a compound having a B-0-C bond (JP-A No. 62-84107), an electron donor compound having a C-O or C-N bond (JP-A No. 61-276804), P-0 -Compounds having a C bond (JP-A-61-2
No. 76803) discloses a method of controlling the MFR of the resulting polymer by adding a heterocyclic compound containing N or O (Japanese Patent Application Laid-Open No. 207405/1986) to the catalyst system.

Although it is possible to produce a polymer with a low MFH by the above method, it is generally accompanied by a significant decrease in polymerization activity, and depending on the type of additive, the product may be colored or smelled.

[Technical means to solve problems]

The present invention provides a method for producing a polymer having a small melt viscosity index (MFR) in ethylene polymerization or copolymerization of ethylene and an α-olefin having 3 or more carbon atoms under high temperature and high pressure.

The present invention provides ethylene or ethylene and α-
A catalyst system consisting of a catalytic solid component, component (1) and component (2) obtained by contacting a halogenated titanium compound with a solid produced by reacting a mixture with an olefin with component III and the reaction product of components I and H below. 200 kg/
This invention relates to a method for polymerizing and copolymerizing ethylene, characterized in that the polymerization is carried out at a pressure of 125° C. or higher and a temperature of 125° C. or higher.

Component l; formula, AIX'! Aluminum halide represented by. (In the formula, XI represents a chlorine atom, a bromine atom, or an iodine atom.) Component II: An organosilicon compound represented by the formula, RIaS>(OR")nn. (In the formula, R1 and Rt are each , represents an alkyl or phenyl group having 1 to 8 carbon atoms, and n
is an integer from O to 3. ) Component III: Grignard compound represented by the formula R"?igX". (In the formula, R3 represents an alkyl group having 1 to 8 carbon atoms, and x2 represents a halogen atom.) Component ■: Formula, Al
An organoaluminum represented by R4mX'. (In the formula,
R4 represents an alkyl group having 2 to 6 carbon atoms, and x3 represents a halogen atom. m is an integer from 1 to 3. ) The aluminum halide used as component I in the present invention is hygroscopic and it is difficult to use a completely anhydrous one, so in the present invention aluminum halide containing a small amount of water is also used. be able to. Specific examples include aluminum trichloride, aluminum tribromide, and aluminum triiodide, with anhydrous aluminum chloride being particularly preferred.

Specific examples of the organosilicon compound as component (2) used in the present invention include tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, methyltriethoxysilane, ethyltributoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane. , phenyltributoxysilane, dimethyljethoxysilane, diphenyldimethoxysilane, diphenyljethoxysilane, trimethylethoxysilane, and trimethylbutoxysilane. Especially tetraethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane,
Phenyltriethoxysilane and dimethyljethoxysilane are preferred.

Components ■ and II used in the reaction of components I and ■
The molar ratio (1/II) is usually in the range of 0.4 to 1.5, preferably 0.7 to 1.3, and an inert solvent such as hexane or toluene may be used when reacting the two. I can do it. The reaction temperature is usually 10 to 100°C, preferably 2
The temperature is 0 to 80°C, and the reaction time is usually 0.2 to 5 hours, preferably 0.5 to 3 hours.

Examples of the Grignard compound as component (2) used in the present invention include ethylmagnesium chloride, propylmagnesium chloride, butylmagnesium bromide, ethylmagnesium bromide, propylmagnesium bromide, butylmagnesium bromide, ethylmagnesium iodide, phenylmagnesium chloride, Examples include hexylmagnesium chloride and octylmagnesium chloride. Examples of the solvent for the Grignard compound include aliphatic ethers such as diethyl ether, dibutyl ether, diisopropyl ether, and diisoamyl ether, and aliphatic cyclic ethers such as tetrahydrofuran.

A solution of the reaction product of components (2) and (2) is reacted with component (2). The amount of component (1) to be used is usually 0.5 to 3 in molar ratio (I [[/I)] to component I used in the preparation of the reaction product.
, preferably 1.5 to 2.3.

The reaction temperature is usually -50 to 100°C, preferably -20 to
50''C. The reaction time is usually 0.2 to 5 hours, preferably 0.5 to 3 hours.

In the present invention, the white solid obtained in the above reaction is thoroughly washed with an inert solvent and then brought into contact with a halogenated titanium compound. For the contact treatment, conventionally well-known methods can be adopted. For example, the solid is dispersed in an inert solvent in which a titanium halide compound is dissolved, or the solid is dispersed in a liquid titanium halide compound without using a solvent. let Contact treatment of this solid with a halogenated titanium compound is carried out under stirring.
The temperature is usually 50 to 150°C, and the contact time is usually 0.2 to 5 hours, although there is no particular restriction. Moreover, this contact treatment can also be performed multiple times.

The halogenated titanium compound Toshite that can be used in the contact treatment has the formula Tt(OR)p, where X4-P(+) is an integer of O to 3, and X represents a halogen atom. ). Specific examples include tetrachlorotitanium, tetrabromotitanium,
Mention may be made of trichloromonobutoxytitanium, tribromoethoxytitanium, trichloromonoisopropoxytitanium, dichlorojethoxytitanium, dichlorodibutoxytitanium, monochlorotriethoxytitanium, and monochlorotributoxytitanium. Particularly preferred are tetrachlorotitanium and trichloromonobutoxytitanium.

After the contact treatment, the treated solids are generally separated from the treatment mixture and thoroughly washed with an inert solvent.

Specific examples of organoaluminum as component (2) used in the present invention include trimethylaluminum, triethylaluminum, trioctylaluminum, dimethylaluminum chloride, diethylaluminum fluoride, dimethylaluminum chloride, ethylaluminum sesquichloride, butylaluminum sesquichloride, Mention may be made of ethylaluminum dichloride.

The molar ratio (AI/Ti) between Ti@ and component (2) in the catalyst solid component used for polymerization is usually 0. l to 50, preferably 0.
It ranges from 5 to 30.

The organosilicon compound used as component (2) in the polymerization together with the catalyst solid component and component (2) can be the same as or different from the organosilicon compound used in the reaction with component (2). The molar ratio (n/AI) of component (1) and component (2) used in the polymerization is usually 0.05 to 1.0, preferably 0.
．． It is in the range of 1 to 0.8.

There is no particular restriction on the order of addition of the catalyst solid component, component (1), and component II, but for example, a mixed solution of components (1) and (2) may be prepared and used by diluting with a solvent in advance, or without diluting. In this case, the mixed solution can also be heat-treated.

Examples of the α-olefin having 3 or more carbon atoms to be copolymerized with ethylene used in the present invention include 1-butene, 1-hexene, 4-methylpentene-1, and 1-octene.

The polymerization conditions in the present invention include a polymerization pressure of 200 kg/d.
Above, usually 200-3000kg/cll, preferably 500-2000kg/c4. Polymerization temperature is 125
℃ or higher, usually 125 to 300℃. As the reactor, conventionally known reactors such as autoclave reactors and tubular reactors can be used. The polymerization time is not particularly limited, but is usually 10 to 1200 seconds, preferably 20 to 600 seconds.

〔Example〕

The present invention will be explained in detail below.

In the examples, "polymerization activity" is the yield (kg) of polymer produced per Ig of titanium in the catalyst solid component, and rMFRJ is 2, according to ASTM D1238.
Melt index of the resulting polymer measured at 190° C. under a load of 16 kg.

Example 1 (1) 150 moles of anhydrous aluminum chloride at the bottom of the catalyst solid component were added to 4001 toluene, and then 150 moles of tetraethoxysilane were added dropwise with stirring, and after the dropwise addition was completed, the reaction was carried out at 25° C. for 5 hours.

After the reaction mixture was cooled to -10'C, diisoacryl ether 2501 containing 300 moles of butylmagnesium chloride was added dropwise to the reaction mixture over a period of 5 hours while stirring. The temperature of the reaction system was maintained within the range of -10 to 0°C. After the dropwise addition was completed, the reaction was continued at -10°C for 1 hour. The precipitated solid was filtered off and washed with toluene and then with n-hebutane.

This solid was suspended in toluene 2501, 1500 mol of titanium tetrachloride was added to this suspension, and the solid and titanium tetrachloride were brought into contact with each other at 90° C. for 3 hours while stirring. At the same temperature, the treated solid was filtered off and washed with toluene and then with n-hebutane. The titanium content of the obtained catalyst solid component was 4.8
% by weight.

28 kg of the catalyst solid component obtained above was suspended in 1850 f of mineral oil to prepare a mineral oil slurry of the catalyst solid component.

(2) Total length of copolymerization of ethylene and 1-butene: 400
m tubular reactor, 0.7 wol.
2 mo1% hydrogen was continuously supplied. At the same time, a mineral oil solution of methyltriethoxysilane (MTES), diethylaluminium chloride (DEAC), and a mineral oil slurry of catalyst solid components were added at 50% each.
It was continuously supplied from the injection port provided in the reaction tube at an injection rate of 1/hour, 4.21 hours, and 14.542 hours/hour. At this time, the molar ratio of Si/^l is 1/4,
The AI/Ti molar ratio was 2/1.

The inlet temperature of the reaction tube was maintained at 140°C and the maximum temperature was maintained at 250°C, and ethylene and 1-butene were copolymerized under a pressure of 1500 kg/ail.

Table 1 shows the results of continuous operation for 5 hours under the above conditions.

Comparative Example 1 Example 1 was repeated except that methyltriethoxysilane was not used during the polymerization. The polymerization results are shown in Table 1.

Examples 2 to 4 The molar ratio (Si/^l) of methyltriethoxysilane and diethylaluminium chloride during polymerization was 1/10 (Example 2), 115 (Example 3), 1/3 (Example 4)
) Example 1 was repeated with the following changes. The polymerization results are shown in Table 1.

Examples 5 to 10 Tetraethoxysilane (TES) (Example 5), tetrabutoxysilane (TBS) (Example 6), phenyltriethoxysilane (PTES) (Example 7) instead of methyltriethoxysilane during polymerization , phenyltrimethoxysilane (PTl'lS) (Example 8), butyltriethoxysilane (BTES) (Example 9), dimethyljethoxysilane (DMDBS) (Example 10)
Example 1 was repeated except that . The polymerization results are shown in Table 1.

Example 11 (1) Synthesis of catalyst solid component 150 mol of anhydrous aluminum chloride was added to toluene 4001, then 150 mol of methyltriethoxysilane was added dropwise with stirring, and after the dropwise addition was completed, the reaction was carried out at 25°C for 5 hours. . After cooling the reaction mixture to -10°C, diisoamyl ether 2501 containing 300 mol of butylmagnesium chloride was stirred. was added dropwise to the reaction product mixture over a period of 5 hours. The temperature of the reaction system was maintained within the range of -10 to 0°C. After the dropwise addition was completed, the reaction was continued at -10°C for 1 hour.

The precipitated solid was filtered off and washed with toluene and then with n-hebutane.

This solid was suspended in toluene 2501, 1500 mol of titanium tetrachloride was added to this suspension, and the solid and titanium tetrachloride were brought into contact with each other at 90° C. for 3 hours while stirring. Solid components were filtered off at the same temperature and washed with toluene. By the way-
The solid component was suspended in 2,501 mol of toluene, 1,500 mol of titanium tetrachloride was added to this suspension, and 90 mol of titanium tetrachloride was added under stirring.
After contacting the solid with titanium tetrachloride for 3 hours at 'C,
The catalyst solid component was filtered off at the same temperature and washed with toluene and then with heptane. The titanium content of the obtained catalyst solid component was 4.2% by weight. 26 kg of this catalyst solid component was suspended in 1720f of mineral oil to prepare a mineral oil slurry of the catalyst solid component.

(2) Copolymerization of ethylene and 1-butene 52 mol of ethylene was placed in a tubular reactor with a total length of 400 m! , 1 butene 38
0.20 for the total amount of monomer mixture consisting of molχ
+01χ hydrogen was continuously supplied. At the same time, a mineral oil solution of ethyltriethoxysilane, diethylaluminum chloride, and a mineral oil slurry of the catalyst solid component were added for 51/hour and 4.21.7 hours, respectively.
and 14.5 n hours of continuous feeding from the injection port provided in the reaction tube. At this time, Si/
The molar ratio of Al was 1/4, and the molar ratio of AI/Ti was 2/1. The inlet temperature of the reaction tube is 140℃ 1 The maximum temperature is 25℃
Maintained at 0°C, ethylene and 1
- Copolymerized with butene.

Table 2 shows the results of continuous operation for 5 hours under the above conditions.

Example 12.13 Except that triethylaluminum (TEA) (Example 12) and a mixture (1/1) of diethylaluminium chloride and ethylalgonium sesquichloride (EASC) (Example 13) were used instead of diethylaluminum chloride. Example 11 was repeated.

The polymerization results are shown in Table 2.

Example 14 Diethylaluminium chloride was preheat-treated with methyltriethoxysilane as shown below to give 9.51
Example 11 except that the reactor was injected at an injection rate of 7 hours.
repeated. The polymerization results are shown in Table 2.

[Heat treatment of diethylaluminum chloride with methyltriethoxysilane] Diethylaluminum chloride (10% of methyltriethoxysilane in 1501% of 4 mol/2 mineral oil solution)
0 mol was added dropwise at room temperature over 4 hours with stirring. Since it generated heat, it was cooled and maintained at 40°C. After completion of dripping, 100
The reaction mixture was reacted for 1 hour at "C". The mixture was diluted with mineral oil and subjected to polymerization.

Example 15.16 The monomer composition was changed to 65 mol χ of 1-butene and 35 mol 2 of ethylene (Example 15), 62 mol χ of 4-methylpentene-1 and 38 mol 2 of ethylene (Example 16) Example 11 was repeated except that. The polymerization results are shown in Table 3.

Table 1 Component II Si/AI density MFR polymerized organosilicon
Mol Activity Examples Compound Ratio g/ci g/10 min k
g/gTiTES TES TES TES ES BS TES TMS TES MDES 1/4 1/10 15 1/3 1/4 1/4 1/4 1/4 1/4 1/4 0.924 0.923 0.923 0 .928 0.926 0.924 0.924 0.925 0.923 0.923 0.922 0.9 2.2 1.6 0.5 0.6 0.8 0.9 0.9 1.0 1.3 0 58 72 66 57 35 40 70 68 60 68 80

Claims (1)

[Claims] A halogenated titanium compound is contacted with a solid produced by reacting ethylene or a mixture of ethylene and an α-olefin having 3 or more carbon atoms with a reaction product of components I and II below and component III. A method for polymerizing and copolymerizing ethylene, characterized in that the polymerization is carried out at a pressure of 200 kg/cm^2 or more and a temperature of 125° C. or more in a catalyst system consisting of a catalyst solid component, component IV, and component V obtained by the above method. Component I: Aluminum halide represented by the formula AlX^1_3. (In the formula, X^1 represents a chlorine atom, a bromine atom, or an iodine atom.) Component II; Formula, R^1_nSi(OR^2)_4_-_n
Organosilicon compound represented by (In the formula, R^1 and R^
2 each represents an alkyl group having 1 to 8 carbon atoms or a phenyl group, and n is an integer of 0 to 3. ) Component III: Grignard compound represented by the formula R^3MgX^2. (In the formula, R^3 represents an alkyl group having 1 to 8 carbon atoms, and X^2 represents a halogen atom.) Component IV: Organoaluminum represented by the formula, AlR^4_mX^3_3_-_m. (In the formula, R^4 is a carbon number of 2 to 6
represents an alkyl group, and X^3 represents a halogen atom. m
is an integer from 1 to 3. )