JPS63108005A - Catalyst for highly stereoregular polymerization of alpha-olefins - Google Patents

Abstract

PURPOSE:To obtain the title catalyst which is inexpensive and highly active and can give a highly stereoregular polymer, by combining a specified solid catalyst component with a silicon compound and an organoaluminum compound. CONSTITUTION:A dialkoxymagnesium is suspended in a liquid aromatic hydrocarbon, and titanium tetrachloride and an aromatic dicarboxylic diester are added to the solution and reacted at 80-135 deg.C. The obtained solid substance is separated and further reacted with titanium tetrachloride, and the formed solid product is contacted with a silicon compound of the formula (wherein R is alkyl, vinyl or the like, R' is alkyl and 0<=m<4) and further contacted with an organoaluminum compound to produce a solid catalyst component. This solid catalyst component is combined with a silicon compound (e.g., tetramethoxysilane) and an organoaluminum compound (e.g., triethylaluminum) to form the title polymerization catalyst.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is capable of obtaining a polymer having extremely high stereoregularity while maintaining high activity when subjected to the polymerization of α-olefins. It concerns high performance catalysts.

[Prior art and its problems]

Catalysts for the stereoregular polymerization of propylene include, in addition to the well-known catalyst combining titanium trichloride and an organoaluminum compound, a new type of supported catalyst in which titanium tetrachloride is supported on magnesium chloride together with an electron donor. A number of 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 still room for improvement in terms of the stereoregularity of the resulting polymer, and if high stereoregularity is required, it is recommended to add a large amount of electron donor during polymerization. It was considered indispensable for practical purposes. 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.

In addition, in conventional so-called supported catalysts, it is necessary to use an extremely large excess of organoaluminum compounds relative to the titanium atoms contained in the catalyst, which not only leads to an increase in the cost of polyolefins but also , because it is included as an aluminum component residue in the produced polymer,
It was also a cause of quality deterioration. Therefore, reducing the amount of organoaluminum compounds used was a technical problem to be solved, but simply reducing the amount of organoaluminum compounds used would reduce the activity of the catalyst, and the inventors of the present invention According to findings, the bulk specific gravity of the resulting polymer also decreases.

Furthermore, since the electron donor is usually used in a fixed molar ratio to the organoaluminum compound, in conventional methods, it was necessary to use it in a fairly large amount relative to the solid catalyst component. .

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

[Disclosure of the invention]

The present invention comprises: (I) Dialkoxymagnesium (a) is suspended in an aromatic hydrocarbon (bl) which is liquid at room temperature, and then titanium tetrachloride (c) and a diester of an aromatic dicarboxylic acid (d) are suspended at room temperature. The solid material obtained by the reaction in the temperature range of 135 °C to 135 °C is separated and further reacted with titanium tetrachloride (c) to obtain a solid product, which has the general formula siRm (oR /) 4-m (In the formula, 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 the same as R'. silicon compound (e), where m is 0≦m<4.
A solid catalyst component obtained by contacting with the organic aluminum compound (f); (IT)
General formula SiRm(OR')4-m (wherein R is an alkyl group, cycloargyl 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 as ’.

m is 0≦m<4. The present invention provides a catalyst for highly stereoregular polymerization of α-olefins, characterized by comprising a silicon compound represented by () and an organoaluminum compound (■).

Dialkoxymagnesium (hereinafter simply referred to as (a)) used in the catalyst for polymerizing olefins according to the present invention
a) It is called a substance. ) include jetoxymagnesium, dibutoxymagnesium, diphenoxymagnesium, dipropoxymagnesium, diisobutoxymagnesium, diisopropoxymagnesium, etc. Among them, jetoxymagnesium and dipropoxymagnesium are preferred.

The aromatic hydrocarbon (hereinafter simply referred to as (1)) which is liquid at room temperature (bl) used in the catalyst for polymerizing olefins according to the present invention
) called substance. ) include toluene, xylene, ethylbenzene, flobylbenzene, butylbenzene, etc.

As the aromatic dicarboxylic acid diester (d) (hereinafter simply referred to as (d) substance) used in the catalyst for polymerizing olefins according to the present invention, phthalic acid glue ester is preferable, such as dimethyl phthalate, diethyl Examples include dimethyl phthalate, diimpropyl phthalate, dibutyl phthalate, diisobutyl phthalate, cyamyl phthalate, diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate, and ethylpropyl phthalate.

Examples of the silicon compound (e) (hereinafter simply referred to as (θ) substance) used in the catalyst for polymerizing olefins according to the present invention include alkoxysilane, phenylalkoxysilane, alkylalkoxysilane, vinylalkoxysilane, etc. Specific examples include tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltriisopropoxysilane, diphenyldimethoxysilane, diphenyljethoxy 7rane, ethyltrimethoxysilane, Methyltrimei・
Examples include xysilane, methyltriethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

As the silicon compound (TT) used in the catalyst for polymerizing olefins according to the present invention, an appropriate one can be selected from among those mentioned above as the substance (e).

Examples of the organoaluminum compound (f) above used in the catalyst for polymerizing olefins according to the present invention include trialkylaluminum, dialkylaluminum halide, alkylaluminum civalide, alkylaluminum sesquihalide, and mixtures thereof. It will be done.

A first preferred embodiment for obtaining the above-mentioned solid product is to suspend (a) the substance in the (b) substance, then add titanium tetrachloride, raise the temperature to 80°C or higher, and then (d) ) A method of adding a substance and reacting in a temperature range of 80°C to 135°C is mentioned. In a second preferred embodiment, after adding titanium tetrachloride and the substance (d) at room temperature,
An example is a method in which the reaction is carried out in a temperature range of 0°C to 135°C. Note that the above-mentioned titanium tetrachloride can be used by diluting it with an aromatic hydrocarbon that is liquid at room temperature.

The ratio of each substance used in the preparation of the above-mentioned solid catalyst component is usually 1 g of (a) substance and 0.01 to 2 g of (d) substance.
f, preferably in the range of 0.1 to 1 f, titanium tetrachloride in the range of 0.1 g or more, and preferably in the range of 12 or more. In addition, (1)) substances may be used in any proportion,
It is necessary that the amount is sufficient to form a suspension.

Furthermore, the reaction and contact of each raw material is usually carried out at a temperature from 0°C to the boiling point of the titanium locide used]
It is carried out within a range of 00 hours or less, preferably 10 hours or less.

The solid product obtained as described above is brought into contact with the substance (e) and then brought into contact with the organoaluminum compound (f) to obtain a solid catalyst component. ) The substance is 0.1-57, the organoaluminum compound (f) is 0.1-]OL? Used within the range of Contact with the substance (e) above or contact with the organoaluminum compound (f) shall be carried out at a temperature of 100°C or less.
The test is carried out within 0 hours, preferably within 10-10 hours.

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

The above (d) substance, the solid substance obtained from the (b) substance, titanium tetrachloride and the (d) substance, and the above solid catalyst component are all treated as necessary using an appropriate organic solvent. Washing is preferred.

Preferably, the above operations are carried out in the absence of oxygen, moisture, and the like.

The solid catalyst component produced as described above is combined with the silicon compound and organoaluminum compound described above to form a catalyst for polymerizing olefins. Although the amount of the organoaluminum compound used is not particularly limited, it is preferably small for the reasons mentioned above, and 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. Further, the silicon compound is used in a molar ratio of 1 or less, preferably in the range of 0.005 to 0.5 per mole of the organoaluminum compound.

Polymerization can be carried out in the presence or absence of organic solvents, yet the olefin monomers can be used in both gaseous and liquid states. The polymerization temperature is 20
The temperature is 0°C or lower, preferably 100°C or lower, and the polymerization pressure is 1
．． 0OKf/c1n2. G or less, preferably 5Q K
g/lyn”・G or less.

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

〔Effect of the invention〕

According to the catalyst of the present invention, it is possible to obtain a polymer having a long stereoregularity that has never been practically obtained in the past, and the activity of the catalyst can also be maintained at a high level.

According to the catalyst of the present invention, the amount of organoaluminum compounds and silicon compounds used during polymerization can be significantly reduced compared to conventional techniques.

Moreover, it has the effect of not causing a decrease in the catalyst activity or the bulk specific gravity of the produced polymer, which has the great advantage of reducing the manufacturing cost of polyolefins, and also
Another advantage is that the amount of residue in the produced polymer due to organoaluminum compounds and silicon compounds can be reduced.

In addition, according to the catalyst of the present invention, the amount of silicon compound used during polymerization can be significantly reduced, so that the problem of odor in the resulting polymer can be substantially solved. This is a greater advantage in polymerization.

Furthermore, conventionally, there was a common drawback in so-called highly active supported catalysts that the activity per unit time of the catalyst decreased significantly as the polymerization progressed, but in the catalyst according to the present invention, - Since the decrease in activity with the elapse of the standing time is extremely small compared to conventionally known catalysts, it is also useful in cases where the polymerization time is longer, such as in copolymerization.

Furthermore, in the production of industrial olefin polymers, it is common to allow hydrogen to coexist during polymerization from the point of view of MI control. Catalysts using esters have the disadvantage that their activity and stereoregularity are significantly reduced in the presence of hydrogen. However, when olefin polymerization is carried out in the presence of hydrogen using the catalyst according to the present invention, the activity and stereoregularity do not decrease, especially even when the MI of the product 1 polymer is extremely high. In the industrial production of polyolefins, the bulk specific gravity of the produced polymer is a very big problem in terms of the capacity of the polymerization equipment, the capacity of the post-treatment process, etc., but the catalyst according to the present invention is extremely effective in this respect as well. It has excellent properties.

[Example, Comparative Example]

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

Example 1 Preparation of solid catalyst component
A 0 ml round bottom flask was charged with 10 g of jetoxymagnesium and 80 ml of toluene to form a suspension.

Then add 20 ml of this suspension! -14
＝ was added and the temperature was raised to 100℃, and 2.5 m of dibutyl phthalate was added.
Added l. Next, the temperature was raised to 115°C, and the mixture was reacted with stirring for 2 hours to obtain a solid substance. The solid material was washed three times with 100 mA' of toluene at 60°C and freshly washed with 100 mA' of toluene at 60°C.
Add 0 me 1TiCAa 20 ynl and make 115
The reaction was allowed to proceed at a temperature of 2 hours with stirring.

After completion of the reaction, washing with 200°C of n-heptane at 40°C was carried out 10 times to obtain a solid product-1. At this time, the titanium content in the solid product was measured and found to be 2.82% by weight.Next, the solid product 37 was placed in a round bottom flask with an internal volume of 300 r/Le equipped with a stirrer, and 100ml of n-heptane was added.
After adding 1.0 ml of J and diphenyldimethoxysilane and stirring thoroughly, 1.0 ml of triisobutylaluminum was added.
0 punishment and diethyl aluminum chloride 0.2ml
was added and reacted at room temperature for 2 hours with stirring. After the reaction was completed, it was washed five times with 100 mg of n-hebutane 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> Internal volume completely replaced with nitrogen gas2. Charge 700 grams of n-heptane into an autoclave with a stirrer,
triethylaluminum so while maintaining a nitrogen gas atmosphere
my, phenyltriethoxysilane 10rn? Then, 19.5 m7 of the solid catalyst component was charged. Thereafter, 150% of hydrogen gas was charged, the temperature was raised to 70°C, and propylene gas was introduced while maintaining a pressure of 6 kg/crn''・G to carry out polymerization for 2 hours. After the polymerization was completed, the obtained The solid polymer was separated, heated to 80°C and dried under reduced pressure.
The amount of polymer dissolved in the polymerization solvent by condensing the r liquid is (A
), and the amount of solid polymer is (B). Further, the obtained solid polymer was extracted with boiling n-heptane for 6 hours to obtain a polymer insoluble in n-heptane, and this amount was designated as (c).

The polymerization activity (D+) in the solid 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. The residual chlorine is represented by (G), the MI of the produced polymer is represented by (H), and the bulk specific gravity is represented by (1).The obtained results are shown in Table 1.

Example 2 An experiment was conducted in the same manner as in Example 1 except that phenyltriethoxysilane was used in place of diphenyldimethoxysilane. 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 19.9 cm of the solid catalyst component was used during the polymerization. The results obtained are as shown in Table 1.

Example 3 An experiment was carried out in the same manner as in Example 1 except that the amount of diphenyldimethoxysilane was changed to 1.5 ml. Note that the titanium content in the solid catalyst component at this time was 2.60% by weight. An experiment was conducted in the same manner as in Example 1, except that 19.21 ng of the solid catalyst component was used during 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 phenyltriethoxysilane was not used during polymerization. The results obtained are shown in Table 1.

Chapter 1 Table

[Brief explanation of the drawing]

FIG. 1 is a schematic drawing to aid in understanding the invention.

Claims (1)

[Claims] 1) (I) Dialkoxymagnesium (a) is suspended in a liquid aromatic hydrocarbon (b) at room temperature, and then titanium tetrachloride (c) and an aromatic dicarboxylic acid are suspended in a liquid aromatic hydrocarbon (b). A solid material obtained by reacting with diester (d) at a temperature range of 80° C. to 135° C. is separated, and this is further reacted with titanium tetrachloride (c) to obtain a solid product, and the solid product is to the general formula SiRm(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 may be the same as R'; m is 0≦m<4), and then the organoaluminum compound (
f) Solid catalyst component obtained by contacting; (II) general formula SiRm(OR')_4_-_m (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'. m is 0≦m<4. 1. A catalyst for highly stereoregular polymerization of α-olefins, comprising a silicon compound represented by (III) and an organoaluminum compound (III). 2) When obtaining the above solid substance, dialkoxymagnesium (a) is suspended in liquid aromatic hydrocarbon (b) at room temperature, then titanium tetrachloride (c) is added, and the temperature is raised to 80°C or higher. Diesters of aromatic dicarboxylic acids (d) after warming
The catalyst for highly stereoregular polymerization of α-olefins according to claim 1, which comprises adding and reacting at a temperature range of 80°C to 135°C. 3) When obtaining the solid substance, titanium tetrachloride (c) and diester of aromatic dicarboxylic acid (d) are added at room temperature and then reacted at a temperature range of 80°C to 135°C. A catalyst for highly stereoregular polymerization of α-olefins according to item 1. 4) High stereoregularity of α-olefins according to any one of claims 1 to 3, in which the titanium tetrachloride (c) is diluted with an aromatic hydrocarbon that is liquid at room temperature. Polymerization catalyst.