JPH0269504A - Production of magnesium chloride-carrying type titanium catalyst - Google Patents

Abstract

PURPOSE:To obtain the title catalyst having narrow distribution of particle size and capable of providing a polyolefin having high bulk specific gravity by bringing MgCl2 having a specific water content into contact with 2- ethylhexanol in a solvent while heating, bringing the resultant magnesium chloride solution into contact with an organic solvent solution containing TiCl2 and then heating the blend solution. CONSTITUTION:Magnesium chloride having <=1wt.% water content is brought into contact with 2-ethylhexanol of 2.2-2.8 gram molecule based on 1 gram molecule magnesium chloride in an inert hydrocarbon (e.g., n-decane) at >=50 deg.C and the resultant magnesium chloride solution is brought into contact with an inert hydrocarbon (e.g., n-hexane) containing titanium tetrachloride of 1-10 gram molecule based on 1 gram molecule magnesium chloride at -30-+10 deg.C and then the blend solution is heated at 50-100 deg.C to provide the aimed magnesium chloride-carrying type titanium catalyst for olefin polymerization.

Description

[Detailed Description of the Invention] Nine fat α-hanging beans! The present invention relates to a method for producing a titanium catalyst supported on magnesium chloride, and more specifically, a method for producing a titanium catalyst supported on magnesium chloride, which can obtain a polymer that exhibits high polymerization activity, has a narrow particle size distribution, and does not have a decrease in bulk specific gravity. The present invention relates to a method for producing a type titanium catalyst.

Technical background of the invention and its problems When producing polyolefins by polymerizing olefins such as ethylene, magnesium chloride-supported titanium catalysts have been widely used.

It is known that such a magnesium chloride-supported titanium catalyst exhibits high activity in olefin polymerization, particularly in ethylene polymerization. and Japanese Unexamined Patent Application Publication No. 1983-1981 filed by the present applicant.
No. 158204 discloses a method containing magnesium, titanium, a halogen, and an alkoxy group and/or an aryloxy group as essential components, which is obtained by contacting magnesium chloride with 2-ethylhexanol and then contacting titanium tetrachloride. A titanium catalyst component which is characterized in that a magnesium chloride-supported titanium catalyst is heat-treated in the presence of an inert hydrocarbon such as n-decane to reduce the alkoxy group and/or aryloxy group content. A modification method is disclosed.

If such a modified magnesium chloride-supported titanium catalyst is used, an olefin polymer with high melt tension and swelling ratio can be obtained.

However, the olefin polymer obtained using the magnesium chloride-supported titanium catalyst as described above has a problem in that its particle size distribution is not sufficiently narrow. In particular, when the above magnesium chloride-supported titanium catalyst is separated into solid and liquid from an inert hydrocarbon and stored or transported in a dry powder form, it is used for olefin polymerization.
The obtained olefin polymer has a wide particle size distribution, and the bulk specific gravity of the obtained olefin polymer is higher than that of an olefin polymer obtained using a magnesium chloride supported titanium catalyst used without solid-liquid separation from an inert hydrocarbon. There was a problem that the bulk specific gravity was smaller than that of . If the bulk specific gravity of the obtained olefin polymer decreases, the productivity of the olefin polymer will decrease, and the fluidity of the olefin polymer powder will decrease, causing problems such as poor penetration into the granulator. will occur.

The present inventors conducted research to solve the above-mentioned problems and found that when preparing a magnesium chloride-supported titanium catalyst, magnesium chloride and 2-ethylhexanol were used in a specific ratio for contact. The present invention was completed by discovering that it is sufficient to do so.

The present invention is an attempt to solve the problems associated with the conventional technology as described above, and the particle size distribution is narrow, and in particular, it is difficult to store or transport the product after solid-liquid separation and in the form of a dry powder. It is an object of the present invention to provide a method for producing a titanium catalyst supported on magnesium chloride, which allows obtaining an olefin polymer having a narrow particle size distribution and a large bulk specific gravity even when used as a catalyst for polymerization of olefins.

1 skin 2 liters! The first method for producing a titanium catalyst supported on magnesium chloride according to the present invention uses magnesium chloride having a water content of 1% by weight or less, and
．． 2-2.8 gram molecules of 2-ethylhexanol in an inert hydrocarbon at a temperature above 50°C, and the resulting magnesium chloride solution is added to the magnesium chloride 1
It is characterized in that it is brought into contact with an inert hydrocarbon containing titanium tetrachloride in an amount of 1 to 10 grams per gram molecule at a temperature range of -30 to 10 degrees Celsius, and then heated to a temperature range of 50 to 100 degrees Celsius. .

The second method for producing a magnesium chloride-supported titanium catalyst according to the present invention uses magnesium chloride having a moisture content of 1% by weight or less, and
．． 2-2.8 gram molecules of 2-ethylhexanol in an inert hydrocarbon at a temperature above 50°C, and the resulting magnesium chloride solution is added to the magnesium chloride 1
After contacting with an inert hydrocarbon containing 1 to 10 gram molecules of titanium tetrachloride per gram molecule at a temperature range of -30 to 10 °C, heating to a temperature range of 50 to 100 °C, and then inert carbonization. It is characterized in that the inert hydrocarbon is removed so that the hydrogen content becomes 0 to 20% by weight.

11al The method for manufacturing the magnesium chloride-supported titanium catalyst according to the present invention will be described in detail below.

In the present invention, first, magnesium chloride having a water content of 1% by weight or less and 2-ethylhexanol are brought into contact with each other at a temperature of 50°C or higher in an inert hydrocarbon, so that magnesium chloride becomes 2-ethylhexanol. A magnesium chloride 7B solution is prepared by dissolving the magnesium chloride in a mixed solvent of 100% and an inert hydrocarbon.

The moisture content of the magnesium chloride used in the present invention is 1% by weight or less, preferably 0.6% by weight or less. However, if the moisture content of the magnesium chloride exceeds 1% by weight, magnesium chloride becomes 2-ethylhexanol. This is not preferable because it does not dissolve uniformly in the mixed solvent of and inert hydrocarbon.

2-Ethylhexanol is used in amounts of 2.2 to 2.8 gram molecules, preferably 2.3 to 2.7 gram molecules, more preferably 2.3 to 2.5 gram molecules, per gram molecule of magnesium chloride and magnesium chloride. The amount of 2-ethylhexanol is preferably less than 2.2 gram molecules per gram molecule of magnesium chloride. On the other hand, if it exceeds 2.8 gram atoms, the particle size distribution of the polyethylene powder synthesized using the obtained catalyst will widen, and especially if the catalyst is stored or transported in powder form, it is not preferable. This is not preferable because the bulk density of the polyethylene powder synthesized later is reduced.

The contact between magnesium chloride and 2-ethylhexanol as described above is usually carried out at a temperature of 50°C or higher, preferably 50-20°C.
It is desirable that the reaction be carried out at a temperature of 0°C, particularly preferably 100 to 150°C.

Further, the contact between magnesium chloride and 2-ethylhexanol as described above is carried out in an inert hydrocarbon,
Examples of such inert hydrocarbons include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; and fats such as cyclopentane, cyclohexane, and methylcyclopentane. Cyclic hydrocarbons: Aromatic hydrocarbons such as benzene, toluene, and xylene; Halogenated hydrocarbons such as ethylene chloride and chlorobenzene; and mixtures thereof. Among these inert hydrocarbon media, it is particularly preferable to use aliphatic hydrocarbons.

Next, the magnesium chloride solution obtained as described above is brought into contact with an inert hydrocarbon containing titanium tetrachloride.

At this time, titanium tetrachloride is preferably contacted in an amount of 1 to 10 grams, preferably 2 to 5 grams, per 1 gram molecule of magnesium chloride. If the amount is less than 1 gram molecule, the resulting catalyst particle size will be significantly reduced, which is undesirable, while if it exceeds 10 gram molecules, the bulk specific gravity of the polyolefin synthesized using the resulting catalyst will decrease. Therefore, it is undesirable.

The contact between the magnesium chloride solution and titanium tetrachloride as described above is desirably carried out at a temperature of -30 to 10°C, preferably -20 to 0°C, more preferably -15 to 0°C.

The contact between the magnesium chloride solution and titanium tetrachloride as described above is carried out in an inert hydrocarbon.
- An inert hydrocarbon similar to that used in contacting with ethylhexanol is used, but it is not necessarily necessary to use the same hydrocarbon as in contacting magnesium chloride with 2-ethylhexanol.

Then, after contacting the magnesium chloride solution and titanium tetrachloride in an inert hydrocarbon as described above, the resulting contact product is heated to a temperature of 50 to 100°C, preferably 60 to 90°C, and more preferably 70 to 90°C. Heat to temperature. At this time, the heating time is desirably about 1 minute to 10 hours, preferably about 10 minutes to 2 hours.

After contacting the magnesium chloride solution and titanium tetrachloride in an inert hydrocarbon in this manner, heating the resulting contact material to a temperature of 50 to 100°C causes the magnesium chloride supported titanium catalyst to become inert and carbonized. Obtained in suspension in hydrogen.

At this time, the amount of titanium supported in the catalyst can be increased by further adding titanium tetrachloride to the suspension, which is preferable. In this case, the amount of titanium tetrachloride added is 90 to 4 grams per gram of magnesium molecule. molecules, preferably 1 to 3 gram molecules, particularly preferably 1 to 2 gram molecules.

The magnesium chloride-supported titanium catalyst suspended in the inert hydrocarbon thus obtained can be used as is as a catalyst component for olefin polymerization, but this magnesium chloride-supported titanium catalyst can be removed from the suspension. After solid-liquid separation by r-filtration, etc., and then dried, it is stored or transported as a powdered magnesium chloride-supported titanium catalyst with an inert hydrocarbon content of 0 to 20% by weight, and then used for olefin polymerization. You can also do that. In addition, in order to facilitate control of the inert hydrocarbon content, a high boiling point substance such as liquid paraffin may be added to dry.

The magnesium chloride-supported titanium catalyst obtained as described above is used in olefin polymerization in combination with an organometallic compound of a metal from Group 1 to Group 3 of the periodic table, preferably an organoaluminum compound catalyst component.

As the organic aluminum compound catalyst component, a compound having at least one AJ-carbon bond in the molecule can be used. Examples of such compounds include, for example, represents a halogen atom, O<m≦3, n is 0≦n<3, p is 0≦p<3, q is a number of 0≦q<3, and m+nfP+(1=3
Examples include organoaluminum compounds represented by (where M is Li, Na, or Ni, and R1 is the same as above), complex alkylated compounds of Group 1 metals and aluminum, and the like. .

Examples of the organic aluminum compounds belonging to (i) above include the following compounds.

General formula R' Aj (OR2') l 3-1 (wherein R and R2 are the same as above, 0m is preferably 1
゜5≦m≦3), general formula RA j x 3-
.

(wherein R1 is the same as above, X is halogen, and m is preferably O<m<3), general formula RA j H3-.

(In the formula, R1 is the same as above, 9m is preferably 2≦m<3
), (wherein R and R2 are the same as above, X is halogen, O
hm≦3.0≦n<3.0≦q<3, m+n+q=3
Examples include compounds represented by

More specifically, the aluminum compounds belonging to (i) include trialkylaluminum such as triethylaluminum and tributylaluminium; trialkenylaluminum such as triisoprenylaluminum; dialkylaluminum alkoxide such as diethylaluminum ethoxide and dibutylaluminum butoxide. ; alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide;
50.5 Partially alkoxylated alkyl aluminum with homogeneous composition: Dialkyl aluminum halides such as diethylaluminum chloride, dibutyl aluminum chloride, diethylaluminum bromide: ethyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquipromide Alkylaluminum sesquihalides such as: Partially halogenated alkylaluminiums such as alkylaluminum cybarides such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dibromide; dialkylaluminum hydrides such as diethylaluminum hydride, dibutylaluminum hydride, Other partially hydrogenated alkyl aluminums such as alkyl aluminum dihydrides such as ethyl aluminum dihydride, probyl aluminum dihydride; Mention may be made of halogenated and halogenated alkyl aluminums.

Compounds similar to (i>) include organoaluminum compounds in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom. Examples of such compounds include (CH) AJIOAj (
C2H5)2, (CH) AJOAj(C4H9)2
, C2H5 methylaluminoxane, and the like.

As the compound belonging to (ii) above, L! AN
(C2H5) 4, L! AJ (C-t 1415) 4 and the like can be mentioned.

Among these, it is particularly preferable to use trialkylaluminum or alkylaluminum in which two or more of the above-mentioned aluminum compounds are combined.

The magnesium chloride-supported titanium catalyst according to the present invention is used in combination with the organoaluminum compound catalyst component as described above for homopolymerization of olefins, copolymerization of olefins, or copolymerization of olefins and polyenes. Such olefins used in the present invention include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 3-methyl-1-pentene.
2 or more carbon atoms such as pentene, 1-octene, 1-decene, etc.
In the polymerization method of the present invention, these olefins can be used alone or in combination. Among these olefins, it is preferable to carry out homopolymerization of ethylene or to carry out copolymerization of ethylene and the .alpha.-olefin. When such a mixed olefin is used, the content of ethylene, which is the main component, is usually 70 mol% or more, preferably 90 mol% or more.

In addition, when performing homopolymerization or copolymerization of these olefins, compounds having polyunsaturated bonds such as conjugated dienes and non-conjugated dienes can also be used as polymerization raw materials. As such a diene compound, butadiene, isoprene, 1,4-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, etc. are used.

In the polymerization method of the present invention, the olefin polymerization reaction is
It is usually carried out in the gas phase or liquid phase.

When the above-mentioned olefin polymerization reaction is carried out in a liquid phase, the polymerization reaction can also be carried out in the presence of an inert solvent. Examples of inert solvents that can be used for polymerization include propane, Aliphatic hydrocarbons such as butane, pentane, hexane, octane, decane, and kerosene, alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, and methylcyclohexane, and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene. For example,

Each catalyst component is preferably about 0.0005 to about 1 mmol, more preferably about 0 mmol, in terms of titanium atoms of the magnesium chloride-supported titanium catalyst component per 1 J of reaction volume.
．． 0.001 to about 0.5 mmol and the organoaluminum compound with an aluminum/titanium (atomic ratio) of about 1
It is desirable to use an amount of from about 2000 to about 2000, preferably from about 10 to about 500.

The polymerization temperature of the olefin is, for example, about 20 to about 300°C.
It is. Moreover, the polymerization pressure is, for example, atmospheric pressure to about 100+r/d-G, especially about 2 to about 50 kg/aa.
-G is preferable.

In olefin polymerization, in order to adjust the molecular weight,
It is better to coexist with hydrogen.

Using the olefin polymerization catalyst composed of the magnesium chloride-supported titanium catalyst component and the organoaluminum compound catalyst component prepared as described above, polymerization of olefins, especially ethylene, or copolymerization of ethylene with other α-olefins can be carried out. When this is carried out, the olefin polymerization catalyst exhibits high activity, and a polymer having a narrow particle size distribution can be obtained, and a polymer having a large bulk specific gravity can also be obtained.

Moreover, even if the magnesium chloride-supported titanium catalyst is solid-liquid separated, dried, stored or transported in powder form, and then used as an olefin polymerization catalyst component, an olefin polymer without a decrease in bulk specific gravity can be obtained. Therefore, when olefins, especially ethylene, are polymerized using an olefin polymerization catalyst containing a magnesium chloride-supported titanium catalyst component as described above, the polymer can be produced with high productivity, and the resulting polymers do not adhere to each other. Moreover, the resulting polymer has excellent moldability.

In the present invention, when preparing the magnesium chloride-supported titanium catalyst, the 2-ethylhexanol/magnesium chloride ratio is set to 2.2 to 2.8, so the magnesium chloride-supported titanium catalyst obtained is When used in combination with an organoaluminium compound catalyst to polymerize olefins, particularly ethylene, it is possible to obtain polymers with a narrow particle size distribution and high bulk specific gravity.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

[Ti catalyst] 0.32% by weight in a reactor with a stirrer that was sufficiently purged with nitrogen.
95.23 grams of magnesium chloride powder having a water content of , 543 ml of purified n-deca'/ and 306 grams of 2-ethylhexanol were added and thermally reacted at 140 DEG C. for 3 hours to obtain a solution of magnesium chloride.

4 equipped with a 100ml funnel that was sufficiently purged with nitrogen.
Into a 00 cal reactor equipped with a stirrer, 100 ml of the above magnesium chloride solution (Mg Cj2100IS110
1 equivalent) was added to the funnel, and a mixture of 91.2 ml of n-decane and 24.8 ml of titanium tetrachloride was added to the 400-degree reactor, and after cooling the mixture to 15°C, the mixture was poured into the upper funnel. Magnesium chloride solution was added dropwise over 2 hours. After the completion of the dropwise addition, the temperature was kept at -5°C for 1 hour, and then the temperature was raised to 20°C over 1 hour. Before the temperature was further raised to 80°C, 16.5 ml of the solution was added dropwise. After the completion of the reaction, titanium tetrachloride was added and stirred and mixed at 80°C for 30 minutes, the solid portion was isolated by filtration while hot, and then thoroughly washed with n-hexane to obtain a hexane suspension of the solid catalyst. Obtained. The composition of the solid catalyst is shown in Table 1.

A portion of the hexane suspension of the solid catalyst (corresponding to solid catalyst 5) was collected and added to a 300 ml reactor equipped with a Teflon stirrer. Furthermore, 0.56 t of liquid paraffin was added and mixed with stirring. While flowing nitrogen through the reactor at a rate of 808 J/Hr, the reactor was placed on a slip bed at 40°C,
Hexane was evaporated.

A dry catalyst containing approximately 10% liquid paraffin was thus obtained.

[Polymerization of ethylene] Purified hexane 1 was placed in a 21 autoclave under a nitrogen atmosphere.
After adding 1.0 mmol of triethylaluminum and the above! ! Preparation method The obtained powdered Ti catalyst component was suspended in hexane to give 0.02 mmol in terms of Ti atom.
After adding a certain amount of hydrogen, the temperature was raised to 80℃ and 4.0kg/a of hydrogen was added.
The temperature at the time of polymerization was 8.
The temperature was adjusted to 0°C.

After the polymerization was completed, the ethylene polymer was separated from the hexane solvent and then dried.

The results are shown in Table 1.

L Transparency 1 An attempt was made to synthesize a solution of magnesium chloride in accordance with Example 1 using magnesium chloride with a water content of 1.3% by weight, but a uniform transparent solution could not be obtained.

2- used in the synthesis of magnesium chloride in L1 Medical Example 1
A catalyst was synthesized and polymerized in the same manner as in Example 1 except that 306 grams of ethylhexanol was replaced with 391 grams.

24.8 ml of titanium tetrachloride used in Example 1 was
A catalyst was synthesized and polymerization was carried out in the same manner as in Example 1, except that the amount was changed to 200 wl.

Kuhodan 1 A catalyst was synthesized and polymerized in the same manner as in Example 1, except that the contact temperature between the magnesium chloride solution and the n-decane diluted titanium tetrachloride solution was 30°C.

L calibration plate 5 In the synthesis of the magnesium chloride solution in Example 1, the reaction temperature was changed from 140°C to 25°C and the mixture was stirred and mixed for 48 hours, but uniform magnesium chloride was not obtained.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a process for preparing an olefin polymerization catalyst according to the present invention.

Claims (1)

[Claims] 1) Magnesium chloride having a water content of 1% by weight or less;
For 1 gram molecule of magnesium chloride, 2.2 to 2.
8 gram molecules of 2-ethylhexanol are brought into contact with 2-ethylhexanol in an inert hydrocarbon at a temperature of 50° C. or higher, and the resulting magnesium chloride solution is mixed with 1 to 10 gram molecules of 4-ethylhexanol per gram molecule of magnesium chloride. A method for producing a titanium catalyst supported on magnesium chloride, which comprises contacting with an inert hydrocarbon containing titanium chloride at a temperature range of -30 to 10°C, and then heating to a temperature range of 50 to 100°C. 2) magnesium chloride having a water content of 1% by weight or less;
For 1 gram molecule of magnesium chloride, 2.2 to 2.
8 gram molecules of 2-ethylhexanol are brought into contact with 2-ethylhexanol in an inert hydrocarbon at a temperature of 50° C. or higher, and the resulting magnesium chloride solution is mixed with 1 to 10 gram molecules of 4-ethylhexanol per gram molecule of magnesium chloride. After contacting with an inert hydrocarbon containing titanium chloride at a temperature range of -30 to 10 °C, heating to a temperature range of 50 to 100 °C, and then adjusting the inert hydrocarbon content to 0 to 20% by weight. A method for producing a powdered magnesium chloride-supported titanium catalyst, which comprises removing the inert hydrocarbon.