JPS63182306A - Polymerization of alpha-olefin - Google Patents

Abstract

PURPOSE:To produce an alpha-olefin polymer superior in stereoregularity at a relatively low temperature, by supplying specific solid catalyst component to heated system, in which an organic A1 compound and an alpha-olefin are present, to polymerize the monomer. CONSTITUTION:A solid material obtained by adding, to a suspension of 1g of dialkoxymagnesium in an aromatic hydrocarbon at ordinary temperatures, 0.1g or more of TiCl4 and 0.01-2g of an aromatic dicarboxylic diester to react at 80-135 deg.C, is reacted with TiCl4 of 100hr. or less to produce a solid product. 1g of the solid product is then contacted with 0.1-10g of a Si compound of the formula [wherein R is (cyclo)alkyl, vinyl or aryl; R' is alkyl; and 0<=m<=4] followed by contact with 0.1-10g of an organic A1 compound to produce a solid catalyst component. Subsequently, to a reaction system maintained at 70-90 deg.C in which at least an organic A1 compound and an alpha-olefin monomer are present, the solid catalyst component to polymerize the alpha-olefin monomer is supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for polymerizing α-olefins using a novel catalyst.

[Prior art and its problems]

Recently, instead of the conventionally well-known combination of titanium trichloride and an organoaluminum compound as a catalyst for the polymerization of α-olefins such as propylene, the active ingredient titanium compound is supported on magnesium chloride together with an electron donor. Methods have been developed and proposed using new types of so-called supported catalysts, such as catalysts used in combination with organoaluminum compounds and electron donors.

However, these new types of so-called supported polymer catalysts are usually used in the industrial polymerization of α-olefins using the so-called continuous polymerization method, in which catalysts and α-olefin monopolymers are continuously supplied to the reaction system. is mainly used, but
When the supported catalyst is applied to this method, its performance is significantly lower than when the badge type catalyst is applied. In order to compensate for this drawback, conventionally, before the catalyst is supplied to the polymerization reaction system, prepolymerization is carried out in a reaction system that is kept at a temperature relatively lower than that of the polymerization reaction system.
The method is to supply it to the above polymerization reaction system.

In other words, when conventional supported catalysts are applied to continuous polymerization methods, their performance deteriorates if they are directly supplied to the high temperature range where the polymerization reaction is already taking place; By carrying out prepolymerization at , a decrease in performance is prevented. The above-mentioned prepolymerization is considered to be an essential means, especially in slurry polymerization, and such a method requires very complicated operations and has several problems, such as the need to install special equipment. It had a point.

Furthermore, since the polymerization reaction is an exothermic reaction, heat removal is required to control the temperature. Therefore, it is preferable to carry out the polymerization at a higher temperature, but with conventional supported catalysts, temperatures around 70°C are required. As a limit, polymerization at a higher temperature than this has the disadvantage that its performance deteriorates.

[Disclosure of the invention]

The present inventors have carried out research aimed at solving the problems in the prior art described above, and as a result of the present invention, the α-
We have succeeded in providing a new method for polymerizing olefins.

That is, in the present invention, at least (1) an organoaluminum compound and an α-olefin monomer are present, and about 70%
The following (III) was added to the reaction system maintained at a temperature of ~90°C.
The present invention provides a method for polymerizing α-olefins, which comprises supplying a solid catalyst component to polymerize the α-olefin monomer.

(1) Dialkoxymagnesium (a) is suspended in a liquid aromatic hydrocarbon (b) at room temperature, and then titanium tetrachloride (c) and a diester of aromatic dicarboxylic acid (
The solid substance obtained by reacting with d) in a temperature range of 80 to 135°C is separated and further reacted with titanium tetrachloride (c) to obtain a solid product, which has the general formula Si
R, (OR'),.

(In the formula, R is an alkyl group, a cycloalkyl group, a vinyl group, or an aryl group, and R' is an alkyl group. When R is an alkyl group, the alkyl group may be the same as R'. is 0≦m<4.) A solid catalyst component obtained by contacting a silicon compound (e) represented by the formula (0≦m<4) and then contacting an organoaluminum compound (f).

The present invention will be described in detail below, but first, the above-mentioned solid catalyst component used in the polymerization method of the present invention will be explained.

The dialkoxymagnesium of (a) (hereinafter simply referred to as (a)
) called substance. ) as jetoxymagnesium,
dibutoxymagnesium, diphenoxymagnesium,
Examples include dipropoxymagnesium, diisobutoxymagnesium, diisopropoxymagnesium, etc., among which jetoxymagnesium and dipropoxymagnesium are preferred.

Examples of the aromatic hydrocarbon (b) that is liquid at room temperature (hereinafter simply referred to as (b) substance) used in the present invention include toluene, xylene, ethylbenzene, propylbenzene, and butylbenzene.

The aromatic dicarboxylic acid diester (d) used in the present invention (hereinafter simply referred to as (d) substance) is as follows:
Diesters of phthalic acid are preferred, such as dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, cyamyl phthalate, dioctyl phthalate, diisooctyl phthalate, diisoamyl phthalate, ethylbutyl phthalate, ethyl isobutyl. Examples include phthalate and ethylpropyl phthalate.

The silicon compound (e) used in the present invention (
Hereinafter, it will simply be referred to as (e) substance. ) include alkoxysilane, phenylalkoxysilane, alkylalkoxysilane, vinylalkoxysilane, etc. Specific examples include tetramethoxysilane, tetraethoxysilane, phenylalkoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, and phenyltriethoxysilane. Triisopropoxysilane, diphenyldimethoxysilane, diphenyljethoxysilane, ethyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, etc. can be given.

(r) or (III) used in the present invention
Examples of the aluminum compounds include trialkylaluminum, dialkylaluminum halide, alkylaluminum civalide, alkylaluminum sesquihalide, and mixtures thereof.

In preparing the above solid catalyst component, a first preferred embodiment for obtaining the above solid product is to suspend (a) the substance in the (b) substance, then add titanium tetrachloride, After raising the temperature to above ℃, (d) adding the substance to 8
0℃～! An example is a method of reacting in a temperature range of 35°C. A second preferred embodiment is a method in which titanium tetrachloride and the substance (d) are added at room temperature and then reacted in a temperature range of 80°C to 135°C. In addition, a method of diluting titanium tetrachloride with an aromatic hydrocarbon which is liquid at room temperature and using it can also be mentioned.

The ratio of each substance used in the preparation of the above solid catalyst component is usually 0.01 to 2 g of (d) substance per 1 g of (a) substance.
g, preferably in the range of 0.1 to 1 g, and titanium tetrachloride in the range of 0.1 g or more, preferably 19 or more.

Further, the substance (b) may be used in any proportion, but it is necessary that the amount is such that a suspension can be formed.

Furthermore, the reaction and contact of each raw material is usually carried out at a temperature between θ°C and the boiling point of the titanium halide used for 100°C.
It is carried out within a range of 10 hours or less, preferably 10 hours or less.

A solid catalyst component is obtained by contacting the solid product obtained in the following manner with the substance (e) and then with an organoaluminum compound (f). ) The substance Q is used in the range of 1 to 5 g, and the organic aluminum compound (f) C is used in the range of 0.1 to 109 g. Contact with the substance (e) above or contact with the organoaluminum compound (f) must be carried out at a temperature of 100°C or less.
This is done within hours, preferably within 10 hours.

The solid product described above is washed with a suitable organic solvent prior to contact with (e) the substance.

In addition, the above-mentioned (d) substance, (b) substance, titanium tetrachloride, the solid substance obtained from the (d) substance, and the above-mentioned solid catalyst component are all washed with an appropriate organic solvent as needed. It is preferable.

These operations in the present invention are preferably carried out in the absence of oxygen, moisture, and the like.

The solid catalyst component prepared as described above is supplied to a reaction system maintained at a temperature of about 70 to 90°C in the presence of an organoaluminum compound and an α-olefin monomer.
- Polymerization of olefin monomers takes place.

At this time, the solid catalyst component and the organoaluminum compound are simultaneously supplied to a reaction system maintained at a temperature of about 70 to 90°C in the presence of the α-olefin monomer to polymerize the α-olefin monomer. It is also possible to mix the solid catalyst component and the organoaluminum compound in advance, and then
It is also possible to carry out the polymerization of α-olefin monomers by feeding them into a reaction system maintained at a temperature of about 70-90'C in the presence of -olefin monomers.

In addition, in order to improve the stereoregularity of the resulting polymer, when using conventional supported catalysts industrially, it is essential to coexist some kind of third component, especially an electron-donating compound, during polymerization. . However, when carrying out the polymerization method according to the present invention, a practically sufficient stereoregularity of the resulting polymer can be obtained without the coexistence of an electron-donating compound during polymerization, but particularly high stereoregularity is required. In such a case, an appropriate amount of the above-mentioned substance (e) may be present.

The amount of the organoaluminum compound used is not particularly limited, but is usually used in a molar ratio of 1 to 50 per mole of titanium atoms in the catalyst component. However, as long as sufficient performance can be obtained, approximately the above molar ratio may be satisfied. In addition, in the reaction system in which the polymerization is carried out, it is also possible to select and use a suitable one from the above-mentioned substances (e), if necessary.

Polymerization can be carried out in the presence or absence of an organic solvent, and the olefin monomer can be used in either gas or liquid state. Polymerization pressure is 10
0kg/cry, '・G or less, preferably 50kg/c
m″・G or less.

α-olefins that are homopolymerized or copolymerized using the polymerization method according to the present invention include propylene, l-butene, and the like.

〔Effect of the invention〕

Conventionally, in the industrial polymerization of α-olefins using so-called supported catalysts, continuous polymerization methods have been mainly used in which catalysts and α-olefin monomers are continuously supplied to the reaction system to carry out polymerization. However, this method has the disadvantage that its performance is significantly lower than when it is applied in a batch manner. Therefore, before supplying the catalyst to the polymerization reaction system, a method is generally carried out in which prepolymerization is performed in a reaction system that is kept at a temperature relatively lower than that of the polymerization reaction system, and then the catalyst is supplied to the above polymerization reaction system. It is. This method is considered to be an essential means, especially in slurry polymerization, but such a method requires extremely complicated operations and special equipment. However, in the polymerization method according to the present invention, the performance degradation as described above does not occur, and extremely excellent performance can be obtained even at temperatures above the normal polymerization reaction temperature range without using means □ such as prepolymerization. Can be done. Furthermore, since the polymerization reaction is an exothermic reaction, it is preferable to carry out the polymerization at a higher temperature from the viewpoint of heat removal, etc. However, in the conventional polymerization method using a so-called supported catalyst, the temperature is around 70°C. The actual situation was that the catalyst performance deteriorated in the temperature range exceeding this limit. However, as mentioned above, the polymerization method according to the present invention has the advantage of exhibiting excellent catalytic performance by carrying out the polymerization at a polymerization temperature of about 70 to 90°C, so it does not have the above problems. It can be said that the problem has been completely resolved. Furthermore, this has the advantage of simplifying the equipment and operations normally required for the heat removal, as well as providing significant energy savings.

Furthermore, according to the polymerization method of the present invention, the amount of organoaluminum compound and optionally used silicon compound used during polymerization can be significantly reduced compared to conventional techniques. This brings about the great advantage of being able to reduce the production cost of polyolefins, and also brings about the advantage of reducing the amount of residue in the produced polymer that is caused by the organoaluminum compound and the silicon compound used if necessary.

Furthermore, according to the polymerization method of the present invention, an electron donor is not added during polymerization, or even if it is added, the amount used can be greatly reduced, thereby eliminating the problem of odor in the resulting polymer. can be solved,
This is a great advantage especially in bulk polymerization and gas phase polymerization.

Moreover, the polymerization method according to the present invention has excellent effects in terms of the stereoregularity of the produced polymer.

[Examples and comparative examples]

The method of the present invention will be explained in more detail below using Examples and Comparative Examples.

Example 1 (Preparation of solid catalyst component) A container sufficiently purged with nitrogen gas and equipped with a stirrer! n
A 200 mO round bottom flask was charged with 10 g of jetoxymagnesium and 80 mQ of toluene to obtain an F%G state. Next, TiC (!+20%) was added to this suspension, the temperature was raised to 100°C, and 2.5% of dibutyl phthalate was added.Then, the temperature was raised to 115°C, and the reaction was carried out with stirring for 2 hours to obtain a solid substance. The reaction solid material was washed three times with 100 yen of toluene at 60°C, and freshly washed with 80 yen of toluene,
TiCQ+20ml (l) was added and reacted at 115°C for 2 hours with stirring.

After the reaction was completed, washing was carried out 10 times with 200 g of n-hebutane at 40°C to obtain a solid product. At this time, the titanium content in the solid product was measured and found to be 2.82% by weight. Next, 3 g of the solid product was placed in a round bottom flask with an internal volume of 300 mm and equipped with a stirrer, and 100 ttt of n-hebutane was added.
Q and diphenyldimethoxysilane l, Ott
After adding 1.0 z (l of triisobutylaluminum) and 0.2 inch of diethylaluminium chloride and stirring thoroughly, the mixture was reacted at room temperature for 2 hours with stirring.
two.

After the reaction was completed, it was washed five times with n-hebutane I 00 mQ at room temperature to obtain a solid catalyst component. At this time, the titanium content in the solid catalyst component was measured and found to be 2.56% by weight.

(Polymerization) In an autoclave with an internal volume of 2.012 and equipped with a stirrer and completely replaced with propylene gas, 70 g of n-hebutane was added at room temperature.
0 m, (1) 50 mg of triethylaluminum and 101 g of phenyltriethoxysilane were charged, and the temperature was raised to 80°C. Next, 19.5 zg of the solid catalyst component listed above was charged, and then 150 mQ of hydrogen gas was charged, Next, polymerization was carried out for 2 hours while maintaining a pressure of 6 to 9 zcm"·G with propylene gas. After the completion of polymerization, the obtained solid polymer was filtered out, heated to 80° C., and dried under reduced pressure. Meanwhile, The amount of polymer dissolved in the polymerization solvent after condensing the filtrate is (A)
and the amount of the solid polymer is (B). The solid polymer obtained was extracted with boiling n-hebutane for 6 hours to obtain n-/
A polymer insoluble in butane is obtained, and this amount is designated as (c).

The polymerization activity (D) per catalyst component was expressed by the formula and the yield (E) of the crystalline polymer was expressed by the formula, and the yield (F) of the total crystalline polymer was determined from the formula. Further, residual chlorine in the produced polymer is represented by (G), and Ml of the produced polymer is represented by (II). The results obtained are shown in Table 1.

Example 2 An experiment was conducted in the same manner as in Example 1 except that phenyltriethoxysilane was not used during polymerization and the polymerization time was 1 hour.

The results obtained are shown in Table 1.

Example 3 An experiment was carried out in the same manner as in Example 1 except that the same amount of phenyltriethoxysilane was used instead of diphenyldimethoxysilane when obtaining the solid catalyst component. Note that the titanium content in the solid catalyst component at this time was 2.51% by weight. An experiment was carried out in the same manner as in Example 1 except that 19.9IIIg of the solid catalyst component was used during the polymerization. The results obtained are shown in Table 1.

Example 4 An experiment was conducted in the same manner as in Example 1, except that the amount of diphenyldimethoxysilane used to obtain the solid catalyst component was 1.5 times. Note that the titanium content in the solid catalyst component at this time was 2.60% by weight. An experiment was carried out in the same manner as in Example 1, except that 19.2 tRg of the solid catalyst component was used during the polymerization. The results obtained are shown in Table 1.

Example 5 An experiment was conducted in the same manner as in Example 1 except that the polymerization temperature was 85°C. The results obtained are shown in Table 1.

Comparative Example 1 70 mL of n-hebutane was added at room temperature to an autoclave with an internal volume of 2 and a stirrer and completely replaced with propylene gas.
Charge 0.0m, then triethylaluminum 50Rg
, 10 mg of phenyltriethoxysilane, and 19.5 mg of the solid catalyst component obtained in Example 1 were charged. Thereafter, 150 i of hydrogen gas was charged, the temperature was raised to 70°C, and a pressure of 6 kg/cm''·G was maintained using propylene gas to conduct polymerization for 2 hours. After the polymerization was completed, the same procedure as in Example 1 was carried out. An experiment was conducted using the following methods.The results obtained are shown in Table 1.

Comparative Example 2 Using the solid product obtained in Example 1 in place of the solid catalyst component 19.5 my used in Comparative Example 1,
The experiment was conducted in the same manner as in Comparative Example 1 except for the above. The results obtained are shown in Table 1.

Comparative Example 3 19.5m of solid catalyst component used in the polymerization of Example 1
An experiment was conducted in the same manner as in Example 1 except that 17,7M9 was used as the solid product obtained in the preparation of the solid catalyst component in Example 1 in place of 17,7M9. The results obtained are shown in Table 1.

[Brief explanation of the drawing]

FIG. 1 is a schematic drawing to help understand the present invention. Patent applicant: Toho Titanium Co., Ltd. Representative, patent attorney: Takao Minami

Claims (1)

[Claims] (1) At least (I) an organoaluminum compound and (II) an α-olefin monomer are present, and about 7
The following (III) is added to the reaction system maintained at a temperature of 0 to 90°C.
A method for polymerizing α-olefins, which comprises supplying a solid catalyst component to polymerize the α-olefin monomer. (III) Dialkoxymagnesium (a) is suspended in a liquid aromatic hydrocarbon (b) at room temperature, and then mixed with titanium tetrachloride (c) and a diester of aromatic dicarboxylic acid (d) at 80 to 135°C. The solid material obtained by the reaction is separated and further added with titanium tetrachloride (c).
to obtain a solid product, which has the general formula S
iR_m(OR')_4_-_m (wherein R is an alkyl group, cycloalkyl group, vinyl group, or aryl group, and R' is an alkyl group. When R is an alkyl group, the alkyl group is R') May be the same.m is 0≦m
<4. ) A solid catalyst component obtained by contacting a silicon compound (e) represented by (e) with an organoaluminum compound (f).