JP2514035B2 - Catalyst for highly stereoregular polymerization of α-olefins - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention can provide a polymer having extremely high stereoregularity while maintaining high activity when subjected to the polymerization of α-olefins. It relates to a high performance catalyst.

[Prior art and its problems]

As a catalyst for stereoregular polymerization of propylene, in addition to a conventionally known catalyst combining titanium trichloride and an organoaluminum compound, titanium tetrachloride is supported on magnesium chloride together with an electron donor as a new type of so-called supported catalyst. Many new catalysts have been developed and proposed, including those used in combination with organoaluminum compounds and electron donors. However, in all of these catalysts, there is room for improvement in terms of stereoregularity of the produced polymer, and if high stereoregularity is required, use a large amount of electron donor during polymerization. Was practically indispensable. However, even with such a method, a polymer having extremely high stereoregularity could not be obtained, and it was completely impossible to obtain extremely high stereoregularity while maintaining particularly high activity. .

Further, in the conventional so-called supported catalyst, it is necessary to use a predominantly large excess of an organoaluminum compound with respect to titanium atoms contained in the catalyst, which not only leads to an increase in the cost of these polyolefins, but also produces them. In order to be contained as a residue of aluminum component in the polymer,
It was also a cause of quality deterioration. Therefore, reducing the use amount of the organoaluminum compound was a technical problem to be solved, but merely reducing the use amount of the organoaluminum compound lowers the activity of the catalyst. According to this, the bulk specific gravity of the produced polymer is also reduced.

Furthermore, since the electron donor is usually used in a fixed molar ratio with respect to the organoaluminum compound, it has been necessary to use a considerably large amount with respect to the solid catalyst component in the methods generally used in the past. .

An object of the present invention is to provide a novel catalyst for highly stereoregular polymerization of α-olefins, which can solve various problems in the prior art.

[Disclosure of Invention]

In the present invention, (I) a dialkoxy magnesium (a) is suspended in a liquid aromatic hydrocarbon (b) at room temperature, and then titanium tetrachloride (c) and a diester (d) of an aromatic dicarboxylic acid are added. 80 to ° C. to separate the solid material obtained by reacting at a temperature range of 135 ° C., this is further reacted with titanium tetrachloride (c) to give a solid product, the general formula SiR _m to the solid product (OR ') _4-m (wherein 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 is They may be the same, m is 0 ≦ m <4, and a silicon compound (e) represented by
Then, a solid catalyst component obtained by bringing the organoaluminum compound (f) into contact; (II) an epoxyparamenthane compound and (III) an organoaluminum compound, which is characterized by high stereoregularity of α-olefins. A catalyst for polymerization is provided.

Examples of the dialkoxymagnesium (a) used in the catalyst for olefin polymerization according to the present invention (hereinafter simply referred to as the substance (a)) include diethoxymagnesium, dibutoxymagnesium, diphenoxymagnesium, and dipropoxymagnesium. , Diisoptoxymagnesium, diisopropoxymagnesium, etc., among which diethoxymagnesium and dipropoxymagnesium are preferable.

Examples of the above-mentioned (b) aromatic hydrocarbon which is liquid at room temperature and used in the catalyst for polymerization of olefins according to the present invention (hereinafter simply referred to as (b) substance) include toluene, xylene, ethylbenzene, propylbenzene, and butylbenzene. To be

As the diester of the aromatic dicarboxylic acid (d) used in the catalyst for olefin polymerization according to the present invention (hereinafter simply referred to as the substance (d)), a diester of phthalic acid is preferable, and examples thereof include dimethyl phthalate and diethyl phthalate. , Dipropylphthalate, diisopropylphthalate, dibutylphthalate, diisobutylphthalate, diamylphthalate, diisoamylphthalate, ethylbutylphthalate, ethylisobutylphthalate,
Examples include ethyl propyl phthalate.

Examples of the silicon compound (e) used in the catalyst for olefin polymerization according to the present invention (hereinafter simply referred to as (e) substance) include alkoxysilane, phenylalkoxysilane, alkylalkoxysilane, vinylalkoxysilane, and cycloalkyl. Specific examples thereof include alkoxysilane and cycloalkylalkylalkoxysilane. Tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltriisopropoxysilane. , Diphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, Cycloalkenyl trimethoxysilane, and the like vinyltriethoxysilane.

The epoxy paramenthane compound (II) used in the catalyst for olefin polymerization according to the present invention is
It can be used by selecting from 1,8-epoxy paramenthane or one having an alkyl group or a substituent such as halogen bonded thereto.

Examples of the (f) or (III) organoaluminum compound used in the catalyst for olefin polymerization according to the present invention include trialkylaluminum, dialkylaluminum halide, alkylaluminum dihalide, alkylaluminum sesquihalide and mixtures thereof. To be

As a first preferred embodiment for obtaining the solid product, the substance (a) is suspended in the substance (b), titanium tetrachloride is then added, and the temperature is raised to 80 ° C. or higher (d). ) A method of adding a substance and reacting in a temperature range of 80 ° C to 135 ° C. In addition, as a second preferred embodiment,
A method is one 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. The titanium tetrachloride can be used by diluting it with an aromatic hydrocarbon that is liquid at room temperature.

The proportion of each substance used in the preparation of the above solid catalyst component is usually 0.01 to 2 g, preferably 0.1 to 1 g, for 1 g of the (a) substance, and 0.1 g or more of titanium tetrachloride, It is preferably in the range of 1 g or more. Further, the substance (b) is used in an arbitrary ratio, but it is necessary that the amount is capable of forming a suspension.

Furthermore, the reaction and contact of each raw material is usually 100 ° C at a temperature from 0 ° C to the boiling point of the titanium halide used.
It is carried out for not more than 10 hours, preferably not more than 10 hours.

The solid product obtained as described above is contacted with the substance (e) and then with the organoaluminum compound (f) to obtain a solid catalyst component. The substance is used in an amount of 0.1 to 5 g, and the organoaluminum compound (f) is used in an amount of 0.1 to 10 g. The contact with the substance (e) or the contact with the organoaluminum compound (f) is carried out at a temperature of 100 ° C. or lower for 100 hours or less, preferably 10 hours or less.

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

Further, the above-mentioned solid substance obtained from the substance (d), the substance (b), titanium tetrachloride and the substance (d), and the above-mentioned solid catalyst component are all washed with a suitable organic solvent, if necessary. It is preferable.

The above operation is preferably performed in the absence of oxygen and water.

The solid catalyst component produced as described above is combined with the above-mentioned epoxy paramenthane compound and organoaluminum compound to form a catalyst for olefin polymerization. The amount of the organoaluminum compound used is not particularly limited, but is preferably small for the reasons described above, and is usually used in the range of 1 to 50 in terms of molar ratio per mole of titanium atom in the catalyst component. However, as long as sufficient performance can be obtained, the above molar ratio may be satisfied. The epoxy paramenthane compound is used in a molar ratio of 1 or less per mol of the organoaluminum compound.

The 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 temperature is 20
0 ℃ or less, preferably 100 ℃ or less, the polymerization pressure is 100kg /
cm ² -G or less, preferably 50 kg / cm ² -G or less.

The α-olefins homopolymerized or copolymerized using the catalyst according to the present invention are propylene, 1-butene and the like.

〔The invention's effect〕

According to the catalyst of the present invention, it is possible to obtain a polymer having a high stereoregularity which has never been obtained in practice, and the activity of the catalyst can be highly maintained.

According to the catalyst of the present invention, the amount of the organoaluminum compound or silicon compound used during the polymerization can be remarkably reduced as compared with the conventional techniques. Moreover, there is an effect that the catalytic activity and the bulk specific gravity of the produced polymer do not decrease, which brings about a great advantage that the production cost of the polyolefin can be reduced, and the production weight caused by the organoaluminum compound or the silicon compound is reduced. This brings the advantage that the residue in the coalescence can be reduced.

Further, according to the catalyst of the present invention, the amount of silicon compound used during the polymerization can be significantly reduced, so that the problem of odor in the produced polymer can be substantially solved. Greater advantage in polymers.

Furthermore, conventionally, there was a common drawback in so-called highly active supported catalysts, in which the activity per unit time of the catalyst was significantly reduced with the progress of polymerization, but in the catalyst according to the present invention, The decrease in activity with the passage of time is extremely small as compared with conventionally known catalysts, and therefore it is also useful when the polymerization time such as copolymerization is prolonged.

In addition, in the industrial production of olefin polymers, coexistence of hydrogen at the time of polymerization is generally considered from the viewpoint of MI control and the like, but conventional magnesium chloride is used as a carrier and organic carboxylic acid ester is used. The catalyst had a drawback that its activity and stereoregularity were significantly reduced in the presence of hydrogen. However, when olefin polymerization is carried out in the coexistence of hydrogen using the catalyst of the present invention,
In particular, the activity and stereoregularity do not decrease even when the MI of the produced polymer is extremely high. In the industrial production of polyolefin, the bulk specific gravity of the produced polymer becomes a very big problem in terms of the ability of the polymerization apparatus, the ability of the post-treatment step, etc., but the catalyst according to the present invention also has an extremely large problem. It has excellent characteristics.

[Examples and comparative examples]

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

Example 1 <Preparation of solid catalyst component> Capacity 20 fully replaced with nitrogen gas and equipped with a stirrer
A 0 ml round bottom flask was charged with 10 g of diethoxymagnesium and 80 ml of toluene to make a suspension. Next, 20 ml of TiCl ₄ was added to this suspension, the temperature was raised to 100 ° C., and 2.5 ml of dibutyl phthalate was added. Then, the temperature was raised to 115 ° C. and the reaction was performed for 2 hours with stirring to obtain a solid substance. The solid material was washed 3 times with 100 ml of TREEN at 60 ° C. and freshly added with 80 ml of toluene and TiC.
l ₄ 20 ml was added and the reaction was carried out at 115 ° C. for 2 hours with stirring.

After completion of the reaction, wash with 200 ml of n-heptane at 40 ° C for 10
A solid product was obtained by repeating. 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-bottomed flask having an internal volume of 300 ml and equipped with a stirrer, and 100 ml of n-peptane and 1.0 ml of diphenyldimethoxysilane were added and sufficiently stirred, and then 1.0 ml of triisobutylaluminum and 0.2 ml of diethylaluminum chloride were added. ml was added and the mixture was reacted at room temperature for 2 hours with stirring. After completion of the reaction, it was washed 5 times with 100 ml of room temperature n-heptane to obtain a solid catalyst component. At this time, the titanium content of the solid catalyst component was measured and found to be 2.56% by weight.

<Polymerization> 700 ml of n-heptane was charged into an autoclave equipped with a stirrer, which was 2.0 l of the inner solution completely replaced with nitrogen gas, and triethylaluminum 50 mg, 1, while maintaining a nitrogen gas atmosphere.
20 mg of 8-epoxy valamantane, then 19.5 mg of the solid catalyst component were charged. After that, charge 150 ml of hydrogen gas to 70
6kg / cm ² -G while heating to ℃ and introducing propylene gas
Polymerization was carried out for 2 hours while maintaining the above pressure. After completion of the polymerization, the obtained solid polymer was separated, heated to 80 ° C., and dried under reduced pressure. On the other hand, the amount of the polymer dissolved in the polymerization solvent by condensing the liquid is (A), and the amount of the solid polymer is (B). The obtained solid polymer was extracted with boiling n-heptane for 6 hours to obtain a polymer insoluble in n-heptane.
And

The polymerization activity (D) per solid catalyst component is calculated by the formula Express with.

Further, the yield (E) of the crystalline polymer is expressed by the formula And the yield (F) of the whole crystalline polymer is expressed by the formula I asked more. The residual chlorine in the produced polymer is represented by (G), the MI of the produced polymer is represented by (H), and the bulk specific gravity is represented by (I). The results obtained are as shown in Table 1.

Example 2 An experiment was conducted in the same manner as in Example 1 except that phenyltriethoxysilane was used instead of diphenyldimethoxysilane. The titanium content in the solid catalyst component at this time was 2.51% by weight. An experiment was conducted in the same manner as in Example 1 except that 19.9 mg of the solid catalyst component was used for the polymerization. The obtained results are as shown in Table 1.

Example 3 An experiment was conducted in the same manner as in Example 1 except that the amount of diphenyldimethoxysilane was 1.5 ml. The titanium content in the solid catalyst component was 2.60% by weight. An experiment was conducted in the same manner as in Example 1 except that 19.2 mg of the solid catalyst component was used for the polymerization. The results obtained are as shown in Table 1.

Comparative Example 1 An experiment was conducted in the same manner as in Example 1 except that 1,8-epoxy paramenthane was not used during the polymerization. The obtained results are as shown in Table 1.

[Brief description of drawings]

FIG. 1 is a schematic drawing for helping understanding of the present invention.

Claims (4)

(57) [Claims] 1. An (I) dialkoxymagnesium (a) is suspended in a liquid aromatic hydrocarbon (b) at room temperature, and then titanium tetrachloride (c) and a diester (d) of an aromatic dicarboxylic acid are suspended. ) With 80 ° C to 135 ° C in a temperature range to separate a solid substance, which is further reacted with titanium tetrachloride (c) to obtain a solid product. SiR _m (OR ′) _4-m (wherein R is an alkyl group,
A cycloalkyl group, a vinyl group or an aryl group,
R 'is an alkyl group. When R is an alkyl group, the alkyl group may be the same as R '. m is 0 ≦
m <4. ) A solid catalyst component obtained by contacting a silicon compound (e) represented by the formula (e), and then contacting an organoaluminum compound (f); (II) Epoxy paramenthane compound and (III) Organoaluminum compound A catalyst for highly stereoregular polymerization of α-olefins characterized by: 2. An aromatic hydrocarbon (b), which is liquid at room temperature, is obtained by obtaining dialkoxymagnesium (a) when obtaining the above solid substance.
Suspended in it, after which titanium tetrachloride (c) was added,
The method according to claim 1, wherein after the temperature is raised to 80 ° C or higher, the diester (d) of the aromatic dicarboxylic acid is added and the reaction is carried out in the temperature range of 80 ° C to 135 ° C. Stereoregular polymerization catalyst. 3. When obtaining the above solid substance, titanium tetrachloride (c) and diester (d) of aromatic dicarboxylic acid are added at room temperature and then reacted in a temperature range of 80 ° C. to 135 ° C. A catalyst for highly stereoregular polymerization of α-olefins according to claim 1. 4. A high α-olefin as claimed in any one of claims 1 to 3, wherein the titanium tetrachloride (c) is diluted with a liquid aromatic hydrocarbon at room temperature. Stereoregular polymerization catalyst.