JP3330182B2 - Olefin polymerization catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst for polymerization of olefins, and more particularly, to a catalyst having a high activity when used for the polymerization of olefins, to obtain a stereoregular polymer in good yield and to obtain a wide range. The present invention relates to a high-performance olefin polymerization catalyst capable of obtaining a polyolefin having a particle shape close to a spherical shape, having a molecular weight distribution and a small amount of a finely divided polymer having a particle size of 200 μm or less.

[0002]

2. Description of the Related Art Conventionally, a solid catalyst component for olefin polymerization comprising titanium halide, magnesium compound and electron donating compound as essential components, and an olefin polymerization comprising said solid catalyst component and an organoaluminum compound, a silicon compound, etc. Many proposals have been made for a method of polymerizing or copolymerizing an olefin in the presence of a catalyst for use.

For example, Japanese Patent Application Laid-Open No.
No. 3010 discloses a solid catalyst component prepared by heat-treating a product obtained by contacting dialkoxymagnesium, a diester of an aromatic dicarboxylic acid, an aromatic hydrocarbon and a titanium halide in a powder state, An olefin polymerization catalyst comprising an organoaluminum compound and an organosilicon compound is disclosed.

Similarly, a mixed solution of a magnesium compound obtained by reacting a metal magnesium powder with an alkyl monohalide in the presence of iodine, a tetraalkoxytitanium, an aliphatic hydrocarbon and an aliphatic alcohol is added to a mixed solution. A solid catalyst component prepared by contacting titanium tetrachloride in the presence of an aromatic hydrocarbon with a solid product obtained by adding titanium chloride to precipitate a solid substance, adding a diester of phthalic acid, and an organoaluminum. Contacting titanium tetrachloride with a catalyst comprising a compound and a silicon compound (JP-A-63-154705) or a suspension formed from diethoxymagnesium and alkylbenzene, and then reacting by adding phthalic acid dichloride. The solid product obtained by the above is washed with alkylbenzene and the presence of alkylbenzene And a catalyst comprising an organoaluminum compound and an organosilicon compound (see JP-A 1-31).
No. 5406) has been proposed.

[0005] These prior arts are so-called so-called catalysts for removing catalyst residues such as chlorine and titanium remaining in a produced polymer.
It started with the development of a catalyst component with high activity enough to omit the deashing process, and also focused on improving the yield of stereoregular polymer and increasing the sustainability of the catalyst activity during polymerization. There are excellent effects for this purpose.

However, when a catalyst for polymerization of olefins comprising such a highly active catalyst component and an electron donating compound represented by an organoaluminum compound and a silicon compound is used, a conventional titanium trichloride type catalyst component, an organic The molecular weight distribution of the resulting polymer is narrower than when an olefin polymerization catalyst comprising an aluminum compound and an optional electron-donating compound used as a third component is used. However, there is a problem that the moldability is impaired and the range of application is restricted. Further, the resulting polymer contains a large amount of fine powder, which tends to broaden the particle size distribution. When the amount of the finely divided polymer is increased, the continuation of the uniform reaction is hindered, or the process is interrupted due to the blockage of the piping during the transfer of the polymer. Has an undesired effect on Therefore, these phenomena are the main cause in the art to seek a polymer having a particularly large influence on the fine powder having a particle size of 200 μm or less as much as possible and a polymer having a uniform particle size and a narrow particle size distribution.

As means for solving the problem of the molecular weight distribution, for example, attempts have been made to improve the polymer by obtaining a polymer having a wide molecular weight distribution by adopting a multistage polymerization method, but the multistage polymerization method is complicated. However, there are difficulties in industrial production, including cost, such as repeated application of various polymerization operations and recovery of a chelating agent used during polymerization. As a polymerization method for solving such difficulties, Japanese Patent Application Laid-Open No. 3-7703 is known.
Japanese Patent Application Publication No. JP-A-2002-133873 discloses an olefin polymer formed from a solid titanium catalyst component containing magnesium, halogen and an electron donor as essential components, an organoaluminum compound and at least two or more electron donors (organosilicon compounds). A method for polymerizing olefins in the presence of a catalyst has been proposed.

On the other hand, regarding the particle size of the produced polymer, attempts have been made to improve the composition and preparation method of the solid catalyst component used for olefin polymerization to obtain an olefin polymer having a small amount of fine powder polymer and excellent particle size characteristics. Proposed. For example, Japanese Patent Application Laid-Open No. 58-83006 discloses a catalyst comprising magnesium chloride dissolved in 2-ethylhexyl alcohol, a solid catalyst component precipitated with titanium tetrachloride, and a catalyst comprising this catalyst component, organic aluminum and an electron donor. It is disclosed that when olefin is polymerized in the presence of a polymer, a polymer having almost no fine powder and a narrow particle size distribution can be obtained. JP-A-3-72503 discloses that a dialkoxymagnesium, a tetraalkoxytitanate and an organosilicon compound are heated and reacted as starting materials, and the resulting reaction product is treated with a carboxylic acid such as a titanium halide and a metal salt of orthophthalic acid. A method of polymerizing an olefin in the presence of a solid catalyst component obtained by treating with a derivative, and a catalyst comprising an electron-donating compound such as an organometallic compound and a piperidine derivative is disclosed. It has been shown that a highly stereoregular polymer having excellent was obtained in high yield.

[0009]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 3-7 / 1990
According to the polymerization method described in Japanese Patent No. 703, it is said that a complicated multi-stage polymerization step is omitted, and a desired polymer having a wide molecular weight distribution can be obtained. However, the catalyst used in this method requires a combination of two or more kinds of organosilicon compounds as an electron donor, so that there is a problem that the treatment operation needs to be improved.

In the method disclosed in Japanese Patent Application Laid-Open No. 58-83006, a post-process of waste liquid treatment and a corresponding device are required because a large amount of a solubilizing agent or a precipitant is used in the catalyst component preparation stage. Not only is it more complicated,
There is a disadvantage that the effect of controlling the particle size distribution, especially the problem of reducing the finely divided polymer, cannot be sufficiently achieved. On the other hand, in the method of JP-A-3-72503, as apparent from the description of the examples, two kinds of titanium compounds as active components and substantially three kinds of electron donors are used at the time of preparation of the catalyst component. Preparation methods are complicated, such as using components that require extremely close processing operations for stable synthesis, such as carboxylic acid derivatives such as metal orthophthalate, and the production and production costs on an industrial scale are expensive. There are many issues that need to be improved.

[0011] In addition, there are other methods such as pre-sizing or sieving or air-flow classification to remove fine catalyst particles, or installing a polymer removing device such as a filter in the polymerization process. There is a limit in removing fine powder by only such physical treatment, and it is not possible to effectively reduce the fine powder polymer of 200 μm or less.

The present inventors have proposed a catalyst for polymerization of olefins, which can obtain a polymer having a high activity and a wide molecular weight distribution by a multistage polymerization method or a simple operation that does not require two or more electron donor components during polymerization. As a result of diligent studies to develop a compound, it was confirmed that the above-mentioned problems could be effectively solved by combining a solid catalyst component prepared by a specific means with a special organosilicon compound.

The present invention has been made on the basis of the above findings, and has as its object to maintain a high polymerization activity and a stereoregular polymer yield through a simplified operation while maintaining a wide molecular weight distribution. It is an object of the present invention to provide a high-performance olefin polymerization catalyst capable of obtaining a polyolefin having a nearly spherical particle shape having almost no fine powder having a particle size of 200 μm or less.

[0014]

Means for Solving the Problems The olefin polymerization catalyst according to the present invention for achieving the above object is characterized by comprising the following components (A) to (C). (A) spherical dialkoxymagnesium (a), aromatic hydrocarbon (b) and phthalic diester (c) which are liquid at room temperature
And the suspension formed by
(b) and a volume ratio of 1/2 to the total amount of the aromatic hydrocarbons.
A first contact reaction step of adding the following mixed solution with titanium tetrachloride (d), and then raising the temperature and reacting in a temperature range of 80 to 125 ° C. to obtain a reaction product; After washing with hydrogen, and in the presence of an aromatic hydrocarbon (b) which is liquid at ordinary temperature, a titanium tetrachloride (d) having a volume ratio of 1/2 or less based on the total amount of the aromatic hydrocarbon is added, and 80 to 125 ° C. A second contact reaction step of producing a solid component by reacting in a temperature range of, and then subjecting the produced solid component to drying and subjecting to a fine powder removal treatment, followed by a powdered nonionic surfactant (e)
(B) an organoaluminum compound, (C) an organosilicon compound represented by the general formula Si (C ₆ H ₁₁ ) ₂ (OR) ₂ (wherein C ₆ H ₁₁ is a cyclohexyl group, and R is an alkyl group having 1 to 5 carbon atoms).

Among the components for preparing the solid catalyst component (A) of the present invention, the spherical dialkoxymagnesium (hereinafter, sometimes simply referred to as "(a) substance") includes diethoxymagnesium, n-butoxymagnesium, diphenoxymagnesium, di-n-propoxymagnesium, diisopropoxymagnesium, di-se
Examples thereof include c-butoxymagnesium and di-tert-butoxymagnesium, and diethoxymagnesium is preferably used for the purpose of the present invention.

As aromatic hydrocarbons which are liquid at ordinary temperature (hereinafter, sometimes simply referred to as "substance (b)"), toluene,
Xylene, ethylbenzene, propylbenzene, trimethylbenzene and the like are used.

Examples of the phthalic acid diester [hereinafter sometimes simply referred to as “(c) substance”] include, for example, dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, Di-n-amyl phthalate, diisoamyl phthalate, ethyl-n-butyl phthalate, ethyl isobutyl phthalate, ethyl-n-
Propyl phthalate and the like.

Examples of the powdered nonionic surfactant [hereinafter sometimes simply referred to as “substance (e)”] include 1,5-sorbitan ester and 1,4-sorbitan ester.
Specific examples include sorbitan monolaurate, sorbitan monostearate, and sorbitan monooleate. Of these, 1,5-sorbitan monolaurate is preferred. Since the substance (e) needs to be powdered at the time of use, if it is a lump, it is used after being pulverized by a mechanical pulverizing means in advance.

The solid catalyst component (A) is prepared using the above-mentioned substances through a process comprising the following first contact reaction step, second contact reaction step and treatment step. In the first contact reaction step, a suspension is formed from the substance (a), the substance (b) and the substance (c), and the suspension is mixed with the substance (b) and titanium tetrachloride [hereinafter simply referred to as “(d)”. The substance may be referred to as a "substance" in some cases. The (a) substance and the (b) substance are mixed in any proportion as long as a suspension can be formed,
(c) The substance is 0.1-1.0g for 1.0g of (a) substance
Used in the range. The volume ratio of (d) substance is set to 1/2 or less with respect to the total amount of (b) substance, and the quantity ratio is set to 1.0 g or more with respect to 1.0 g of (a) substance.

The formation of the suspension is usually carried out at a temperature from room temperature to the boiling point of the substance (b) but not more than 100 hours, preferably not more than 10 hours.
This is carried out with stirring within a time equal to or less than the time. The contact between the suspension and the mixed solution of the substance (b) and the substance (d) is carried out at around room temperature, preferably at a temperature in the range of 5 to 30 ° C. It is preferable to take into account. Then, the temperature of the mixture was raised to 80 to 12
The reaction is carried out in a temperature range of 5 ° C. with stirring for 10 minutes to 10 hours to obtain a reaction product.

In the second catalytic reaction step, the above reaction product is washed with an aromatic hydrocarbon, and further (d) in the presence of the substance (b).
In this step, a substance is added to cause a contact reaction. The aromatic hydrocarbon used for washing may be the same as or different from the substance (b). The washed reaction product is brought into contact with the substance (d) having a volume ratio of not more than 1/2 in the presence of the substance (b) in a volume ratio to the total amount of the substance (b). The contact reaction is 80 to 12
This is carried out with stirring in a temperature range of 5 ° C. for a period of 10 minutes to 10 hours to produce a solid component. The produced solid component is optionally washed with an inert organic solvent such as n-heptane.

Next, the solid component obtained in the second contact reaction step is dried to a powder, subjected to a fine powder removal treatment by means of air current classification or the like, and then transferred to a treatment step of adding a substance (e). At this time, by adding while stirring, the mixture is effectively mixed and becomes the solid catalyst component (A). (e) The addition amount of the substance is arbitrary as long as the effect of the present invention is not hindered.

The above series of operations is performed, for example, with argon,
It must be performed in an atmosphere of an inert gas such as nitrogen.
The means for contacting each of the above substances is usually performed using a vessel equipped with a stirrer.

Although the solid catalyst component (A) for olefin polymerization of the present invention is obtained through the above-mentioned steps, no special complicated operation is required throughout each step, and it can be smoothly prepared by an extremely simple process. Can be. The processing step is an important requirement that affects the particle shape and particle size distribution of the produced polymer, such as performing fine powder removal treatment in a liquid state before drying, or
(e) Unless the substance is added, it becomes impossible to effectively suppress the fine powder polymer of 200 μm or less.

As the organoaluminum compound as the component (B) constituting the catalyst of the present invention, trialkylaluminum, dialkylaluminum halide, alkylaluminum dihalide or a mixture thereof is applied.

The general formula Si (C) as the component (C)
_{As the} organosilicon compound represented by ₆ H ₁₁ ) ₂ (OR) ₂ , for example, dicyclohexyldimethoxysilane, dicyclohexyldiethoxysilane, dicyclohexyldipropoxysilane, dicyclohexyldibutoxysilane and the like can be mentioned, among which dicyclohexyldimethoxysilane is preferable. It is.

The olefin polymerization catalyst of the present invention is obtained by suspending the solid catalyst component (A) obtained by the above process as it is or in an inert organic solvent, and suspending the suspension in the above-mentioned organoaluminum compound (B). And an organosilicon compound (C). On this occasion,
The organoaluminum compound (B) has a molar ratio of 5 to 1000 with respect to the titanium atom in the solid catalyst component (A), and the organosilicon compound (C) has a molar ratio of 0.002 to the organoaluminum compound (B). Used in the range of 0.5.

The olefins homopolymerized or copolymerized in the presence of the olefin polymerization catalyst according to the present invention include ethylene, propylene, 1-butene, 4-methyl-1-pentene and the like. The polymerization of these olefins is carried out irrespective of the presence or absence of an organic solvent, and the olefin monomer can be used in either a gas or liquid state. The polymerization conditions are usually at a polymerization temperature of 200 ° C. or lower, preferably 1 to 200 ° C.
The polymerization pressure is set at 100 ° C. or less, and the polymerization pressure is set at 100 kg / cm ² · G or less, preferably at 50 kg / cm ² · G or less.

[0029]

The catalyst for olefin polymerization according to the present invention is a solid catalyst component (A) prepared through the above specific process.
Is characterized by a novel structure combining a special organosilicon compound (C) with an organoaluminum compound (B). This component structure acts highly at the time of olefin polymerization to enhance the stereoregularity of the produced polymer. Maintains, has a wide molecular weight distribution, contains almost no fine powder having a particle size of 200 μm or less,
Moreover, each particle performs an effective function to obtain a polyolefin having a nearly spherical shape.

This fact indicates that when comparing the results of Examples and Comparative Examples described later, the polymer obtained by using the catalyst of the present invention has a molecular weight distribution (weight average molecular weight) which is higher than that obtained by using the catalyst of the prior art. / Number average molecular weight) is improved by at least 2, and at the same time, the polymerization activity per catalyst component and the yield of the stereoregular polymer can be clearly confirmed by the data maintained at a high level.

[0031]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples.

Example 1 Preparation of solid catalyst component; After thoroughly replacing the inside of a 500 ml round bottom flask equipped with a stirrer with nitrogen gas,
30 ml of toluene and 20 ml of titanium tetrachloride were added and stirred to form a mixed solution. Then, this mixed solution was added to 20
While maintaining the temperature at ２５25 ° C., a suspension prepared from 10 g of spherical diethoxymagnesium, 50 ml of toluene and 3.6 ml of di-n-butylphthalate was added dropwise over 4 hours. After completion of the addition, the mixture was heated to 90 ° C. and allowed to undergo a contact reaction for 1 hour with stirring (first reaction).
Catalytic reaction step). After the completion of the reaction, the reaction product was washed twice with 100 ml of toluene at the boiling point, and further 20 ml of titanium tetrachloride.
And 80 ml of toluene, and the mixture was subjected to a contact reaction with stirring at 110 ° C. for 2 hours (second contact reaction step). The resulting solid component was washed 10 times with 200 ml of n-heptane at 40 ° C., and then dried until the residual ratio of heptane became 20% by weight or less to obtain a powdery solid component. The obtained powdery solid component was subjected to an airflow classifier [manufactured by Nisshin Engineering Co., Ltd.
TC-15 type] to remove fine powder having a particle size of 11 μm or less, and to prepare a powder of 1,5-sorbitan monolaurate [manufactured by Kao Corp.] "Emazole S-20"] was added and mixed to obtain a solid catalyst component (processing step). The titanium content in the prepared solid catalyst component was 2.53% by weight.

Formation of polymerization catalyst and propylene polymerization: In a 2.0-liter autoclave equipped with a stirrer completely purged with nitrogen gas, 0.0066 mmol equivalent of the above solid catalyst component as Ti atom and triethylaluminum 1 .32 mmol and 0.13 mmol of dicyclohexyldimethoxysilane were added and stirred to form a polymerization catalyst. Thereafter, 1.8 l of hydrogen gas and 1.4 liquefied propylene were used.
and a polymerization reaction was carried out at 70 ° C. for 30 minutes.

Evaluation of properties; total weight of the obtained polymer, amount of insoluble polymer when extracted with boiling n-heptane for 6 hours, polymerization activity per solid catalyst component, yield of total crystalline polymer Rate, the MI of the produced polymer, the molecular weight distribution of the produced polymer of the produced polymer, the amount of fine powder in the produced polymer, etc. are measured and evaluated,
The results are shown in Table 1. The polymerization activity per solid catalyst component, the yield of the total crystalline polymer, and the molecular weight distribution of the produced polymer were shown as values according to the following equations (1) to (3), respectively.

[0035]

[0036]

[0037]

Example 2 In the treatment step, 9.5 g of the powdery solid component was added to 1
A polymerization catalyst was formed under the same conditions as in Example 1 except that 0.5 g of 5-sorbitan monolaurate was added, and a polymerization test was conducted. The titanium content in the solid catalyst component in this example was 2.76% by weight. The properties evaluation results of the obtained polymer are also shown in Table 1.

Example 3 In the treatment step, 8.5 g of the powdery solid component was added to 1
A polymerization catalyst was formed under the same conditions as in Example 1 except that 1.5 g of 5-sorbitan monolaurate was added, and a polymerization test was performed. The titanium content in the solid catalyst component in this example was 2.50% by weight. The properties evaluation results of the obtained polymer are also shown in Table 1.

Comparative Example 1 10 g of diethoxymagnesium and 80 ml of toluene were charged into a round-bottomed flask (capacity: 500 ml) equipped with a stirrer sufficiently purged with nitrogen gas to form a suspension. 20 ml of titanium was added, the temperature was raised to 90 ° C., and 2.7 ml of di-n-butyl phthalate was added. The temperature was further raised to 115 ° C., and the mixture was reacted with stirring for 2 hours. After the reaction, 90
After washing twice with 100 ml of toluene at 20 ° C., 20 ml of titanium tetrachloride and 80 ml of toluene were newly added, the temperature was raised to 115 ° C., and the reaction was carried out for 2 hours with stirring. After the reaction was completed, the solid was washed 10 times with 100 ml of n-heptane at 40 ° C. to obtain a solid catalyst component. The titanium content in this solid catalyst component was 2.61% by weight. Using this solid catalyst component,
A polymerization catalyst was formed under the same conditions as in Example 1 except that phenyltriethoxysilane was used instead of dicyclohexyldimethoxysilane, and an olefin polymerization test was performed. The properties evaluation results of the obtained polymer are also shown in Table 1.

Comparative Example 2 A polymerization catalyst was formed under the same conditions as in Comparative Example 1 except that cyclohexylmethyldimethoxysilane was used instead of phenyltriethoxysilane, and an olefin polymerization test was performed. The properties evaluation results of the obtained polymer are also shown in Table 1.

[0042]

[Table 1]

From the results shown in Table 1, the polymer obtained by using the olefin polymerization catalyst of the present invention has a remarkable broadening of the molecular weight distribution as compared with that of the comparative example, and the formation of a fine powder polymer of 200 μm or less is obtained. Is also significantly reduced. In addition, it was confirmed that the produced polymer had a particle shape that was almost spherical. In addition, the polymerization activity per solid catalyst component and the yield of stereoregular polymer are maintained at a high level.

[0044]

As described above, according to the present invention, a catalyst for polymerization of olefins having a novel constitution in which an organoaluminum compound and one kind of a special organosilicon compound are combined with a solid catalyst component prepared by a specific simplified method, is provided. Provided. According to this catalyst, it is possible to produce a polymer having a wide molecular weight distribution without using a complicated multi-stage polymerization method, and the production of a finely divided polymer having a particle size of 200 μm or less is effectively suppressed. The shape is also almost spherical. In addition, since a highly active and stereoregular polymer can be obtained with a high yield, its utility as a polymerization catalyst for industrial production of polyolefins for various application fields is greatly expected.

[Brief description of the drawings]

FIG. 1 is a schematic flowchart illustrating the configuration of the present invention.

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-62-252404 (JP, A) JP-A-3-153709 (JP, A) JP-A-2-191608 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08F 4/65-4/658

Claims (2)

(57) [Claims] An olefin polymerization catalyst comprising the following components (A) to (C): (A) spherical dialkoxymagnesium (a), aromatic hydrocarbon (b) and phthalic diester (c) which are liquid at room temperature
And the suspension formed by
(b) and a volume ratio of 1/2 to the total amount of the aromatic hydrocarbons.
A first contact reaction step of adding the following mixed solution with titanium tetrachloride (d), and then raising the temperature and reacting in a temperature range of 80 to 125 ° C. to obtain a reaction product; After washing with hydrogen, and in the presence of an aromatic hydrocarbon (b) which is liquid at ordinary temperature, a titanium tetrachloride (d) having a volume ratio of 1/2 or less based on the total amount of the aromatic hydrocarbon is added, and 80 to 125 ° C. A second contact reaction step of producing a solid component by reacting in a temperature range of, and then subjecting the produced solid component to drying and subjecting to a fine powder removal treatment, followed by a powdered nonionic surfactant (e)
(B) an organoaluminum compound, (C) an organosilicon compound represented by the general formula Si (C ₆ H ₁₁ ) ₂ (OR) ₂ (wherein C ₆ H ₁₁ is a cyclohexyl group, and R is an alkyl group having 1 to 5 carbon atoms). 2. The olefin polymerization catalyst according to claim 1, wherein the organosilicon compound (C) is dicyclohexyldimethoxysilane.