JPH0710890B2 - Catalyst for olefin polymerization - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a high-performance catalyst which acts highly active when subjected to the polymerization of olefins, and which can obtain a stereoregular polymer in a high yield. More specifically, dialkoxymagnesium is suspended in a liquid aromatic hydrocarbon at room temperature, and then the composition obtained by contacting with titanium halide is further contacted with titanium halide. At the time of, the diester of aromatic dicarboxylic acid and HLB was 3
To a solid catalyst component obtained by contacting with a nonionic surfactant of the general formula SiRm (OR ') _4- m (wherein R is hydrogen, an alkyl group or an aryl group, and R'is an alkyl group or It is an aryl group, and m is 0 ≦ m ≦ 4.) The present invention relates to a catalyst for olefin polymerization, which comprises a silicon compound and an organoaluminum compound.

[Conventional technology]

Conventionally, a combination of a solid titanium halide and an organoaluminum compound is well known and widely used as a catalyst for olefin polymerization, but the catalyst component and the polymer yield per titanium in the catalyst component (hereinafter referred to as the catalyst) The so-called deashing process for removing the catalyst residue was unavoidable because the polymerization activity per titanium in the catalyst component and the catalyst component was low). Since this deashing process uses a large amount of alcohol or a chelating agent, a recovering device or a regenerating device for them is indispensable, and there are many resources, energy, and other incidental problems, and those skilled in the art can quickly solve the problem. This is an important issue that is desired. In order to eliminate this complicated deashing step, many studies have been made and proposed to increase the polymerization activity per catalyst component, especially titanium per catalyst component.

In particular, as a recent tendency, a transition metal compound such as titanium halide, which is an active ingredient, is supported on a carrier substance such as magnesium chloride, and when subjected to the polymerization of olefins, the polymerization activity per titanium in the catalyst component is dramatically increased. There are many proposals to raise the price.

For example, in JP-A-50-126590, a carrier material, magnesium chloride, is brought into contact with an aromatic monocarboxylic acid ester by mechanical means, and the obtained solid composition is mixed with titanium tetrahalide in a liquid phase. Is disclosed to obtain the catalyst component.

[Problems to be solved by the invention]

However, the chlorine contained in magnesium chloride not only causes the deterioration and yellowing of the produced polymer like the halogen element in titanium halide, but also causes the corrosion of the equipment used in the steps such as granulation and molding. Therefore, a high activity is required so that the effect of chlorine can be practically neglected.However, in the catalyst using the catalyst component using magnesium chloride as a carrier substance disclosed in the above publications, etc., It has not been possible to obtain sufficient performance up to.

Further, when using a catalyst having the above-mentioned magnesium chloride as a carrier, or a highly active supported catalyst which has been recently proposed variously, the polymerization activity per unit time is high at the initial stage of the polymerization, but the decrease with the passage of the polymerization time is large. However, in addition to the problems in the process operation, it was almost impossible to use it in practice when it is necessary to prolong the polymerization time such as block copolymerization.

Further, these catalysts are generally required to coexist with an aromatic monocarboxylic acid ester at the time of polymerization,
In this case, since the amount of the aromatic monocarboxylic acid ester used is larger than that of the ester in the catalyst, there is a drawback in that the produced polymer has a peculiar ester odor.

Further, in the industrial production of polyolefin, the bulk specific gravity of the produced polymer is also an important problem, but the present situation is that it cannot be said to be a sufficient value in the above catalyst system.

The present inventors have achieved the present invention as a result of earnest research in order to solve the problems left over in the prior art and to further improve the quality of the polymer produced.

[Means for solving problems]

That is, a feature of the present invention is that (I) (a) dialkoxymagnesium is suspended in (b) a liquid aromatic hydrocarbon at room temperature, and then (c) the general formula TiX ₄ (formula Medium X is a halogen element.) A composition obtained by contacting with a titanium halide represented by the formula (hereinafter simply referred to as “titanium halide”) is further contacted with the titanium halide, and at this time, one of At (d) a diester of an aromatic dicarboxylic acid and (e)
A solid catalyst component obtained by contacting a nonionic surfactant having HLB of 3 to 12; (II) General formula SiRm (OR ') _4- m (wherein R is hydrogen, an alkyl group or an aryl group, R'is an alkyl group or an aryl group, m is 0 ≦ m ≦ 4, and a olefin polymerized from a silicon compound (hereinafter sometimes simply referred to as a silicon compound) and (III) an organoaluminum compound There is a catalyst for use.

Examples of dialkoxy magnesium used in the present invention include diethoxy magnesium, dibutoxy magnesium, diphenoxy magnesium, dibropoxy magnesium, di-sec-butoxy magnesium, di-tert-butoxy magnesium, and diisopropoxy magnesium. can give.

Examples of the aromatic hydrocarbon which is liquid at room temperature used in the present invention include benzene, toluene, xylene, ethylbenzene, propylbenzene, trimethylbenzene and the like.

The aromatic dicarboxylic acid diester used in the present invention is preferably a phthalic acid diester, for example, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate,
Examples thereof include diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate and ethyl propyl phthalate.

As the nonionic surfactant having an HLB of 3 to 12 used in the present invention, an appropriate one can be selected from various commercially available products and used.

The titanium halide used in the present invention is Ti
Cl _4, TiBr _4, TiI ₄ and others as mentioned among them TiCl ₄ is preferred.

As the silicon compound used in the present invention,
Examples thereof include phenylalkoxysilane and alkylalkoxysilane. Furthermore, examples of phenylalkoxysilane include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltriisopropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like. Examples of the alkoxysilane include tetramethoxysilane, tetraethoxysilane, trimethoxyethylsilane, trimethoxymethylsilane, triethoxymethylsilane, ethyltriethoxysilane, ethyltriisopropoxysilane and the like.

Examples of the organoaluminum compound used in the present invention include trialkylaluminums, dialkylaluminum halides, alkylaluminum dihalides, and mixtures thereof.

The use ratio of each component in the present invention is optional as long as it does not adversely affect the performance of the catalyst to be produced, and is not particularly limited, but usually 1 g of dialkoxymagnesium, diesters of aromatic dicarboxylic acid are 0.01 g. ~ 2g,
It is preferably used in the range of 0.1 to 1 g, the nonionic surfactant having an HLB of 3 to 12 in the range of 0.01 to 1 g, and the titanium halide in the range of 0.1 g or more, preferably 1 g or more. Further, the aromatic hydrocarbon that is liquid at room temperature is used in any proportion as long as it is a quantity that can form a suspension.

Suspension of dialkoxymagnesium in an aromatic hydrocarbon in the present invention is carried out at a temperature usually from room temperature to the boiling point of the aromatic hydrocarbon used, for 100 hours or less, preferably for 10 hours or less. At this time, it is necessary that the suspension does not become a uniform solution. Further, the contact between the suspension and the titanium halide and the contact between the composition obtained by the contact and the titanium halide are usually -20 ° C to the boiling point of the titanium halide used, preferably 50 ° C to 12 ° C.
It is carried out at a temperature of 0 ° C. for 10 minutes to 10 hours.

The contacting means of each component in the present invention is not particularly limited as long as each component can be sufficiently contacted, but it is usually carried out by stirring using a container equipped with a stirrer.

In the present invention, the titanium halide can be diluted with the aromatic hydrocarbon and brought into contact with it, and after the contact, it can be washed with an organic solvent such as n-heptane.

The organoaluminum compound used in the present invention is a molar ratio of titanium atom in the solid catalyst component of 1 to 100.
The silicon compound is used in a molar ratio of 0.01 to 0.5 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 200
℃ or less preferably 100 ℃ or less, the polymerization pressure is 100kg / c
m ² · G or less, preferably 50 kg / cm ² · G or less.

Olefins homopolymerized or copolymerized using the catalyst produced by the method of the present invention are ethylene, propylene,
1-butene, 4-methyl-1-pentene and the like.

〔The invention's effect〕

When olefins are polymerized using the olefin polymerization catalyst according to the present invention, the resulting polymer has extremely high stereoregularity. Furthermore, since the catalyst shows an unexpectedly high value, the amount of catalyst residue present in the produced polymer can be suppressed to a very low level, and since the residual chlorine is extremely small, the product is deashed. The effect of chlorine can be reduced to the extent that no steps are required.

Since chlorine remaining in the produced polymer causes corrosion of equipment used in steps such as granulation and molding, it also causes deterioration of the produced polymer itself, yellowing, etc. What has been obtained brings great benefits to the art.

Further, according to the present invention, by not adding the organic carboxylic acid ester at the time of the polymerization, it is possible to solve the big problem that the ester odor adheres to the produced polymer.

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 over time is extremely small as compared with conventionally known catalysts, and is therefore extremely useful even when the polymerization time such as copolymerization is made longer.

In addition, in industrial olefin polymer production, coexistence of hydrogen during polymerization is generally considered from the viewpoint of MI control and the like, but with conventional magnesium chloride as a carrier, organic monocarboxylic acid ester is used. The catalyst used had the drawback that its activity and stereoregularity were significantly reduced in the presence of hydrogen. However, when olefin is polymerized in the presence of hydrogen using the catalyst according to the present invention, the activity and stereoregularity do not decrease even when the MI of the produced polymer is extremely high. Such an effect has been strongly desired by those skilled in the art. Further, 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 extremely excellent characteristics.

〔Example〕

 The present invention will be specifically described below with reference to examples.

Example 1 [Preparation of catalyst component] The capacity was 500 m, which was sufficiently replaced with nitrogen gas and equipped with a stirrer.
A round-bottomed 1-liter flask was charged with 10 g of diethoxymagnesium, 1 g of Emazol S-20 (manufactured by Kao Corporation) and 40 ml of toluene to make a suspension, and then 60 ml of TiCl ₄ was added to this suspension.
Was added, the temperature was raised to 90 ° C., 3.6 ml of n-butyl phthalate was added, the temperature was further raised to 115 ° C., and the reaction was carried out with stirring for 2 hours. After completion of the reaction, wash twice with 100 ml of toluene at 90 ° C,
100 ml of TiCl ₄ was newly added and reacted at 115 ° C. for 2 hours while stirring. After completion of the reaction, 200 ml of n-heptane at 40 ° C was washed 10 times to obtain a catalyst component. At this time, when the solid-liquid in the catalyst component was separated and the titanium content of the solid was measured.
It was 3.31% by weight.

[Overlap]

700 ml of n-heptane was charged into an autoclave with a stirrer having an internal volume of 2.0 completely replaced with nitrogen gas, and 301 mg of triethylaluminum, 64 mg of phenyltriethoxysilane were charged while maintaining a nitrogen gas atmosphere, and then the catalyst component was titanium. 0.2 mg was charged as an atom. Then 150 ml of hydrogen gas
6k while charging propylene gas and raising the temperature to 70 ° C and introducing propylene gas
Polymerization was carried out for 4 hours while maintaining the pressure of g / cm ² · G.
After completion of the polymerization, the solid polymer obtained was separated, heated to 80 ° C. and dried under reduced pressure. On the other hand, the liquid is concentrated and the amount of the polymer dissolved in the polymerization solvent 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 this amount is designated as (C).

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

Further, the yield (E) of the crystalline polymer is calculated by the formula The yield (F) of all crystalline polymer is expressed by 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 obtained results are as shown in Table 1.

Example 2 An experiment was conducted in the same manner as in Example 1 except that the polymerization time was 6 hours. The results obtained are as shown in Table 1.

Example 3 Leodol instead of Emazol S-20 (manufactured by Kao Corporation)
An experiment was conducted in the same manner as in Example 1 except that SP-L10 (manufactured by Kao Corporation) was used. The titanium content in the solid content at this time was 3.27% by weight. An experiment was conducted in the same manner as in Example 1 during the polymerization. The results obtained are as shown in Table 1.

Example 4 Leodol instead of Emazole S-20 (manufactured by Kao Corporation)
An experiment was conducted in the same manner as in Example 1 except that SP-O10 (manufactured by Kao Corporation) was used. The titanium content in the solid content at this time was 3.36% by weight. An experiment was conducted in the same manner as in Example 1 during the polymerization. The result obtained is the first
As shown in the table.

Comparative Example 1. An experiment was performed in the same manner as in Example 1 except that Emamazole S-20 (manufactured by Kao Corporation) was not used. The titanium content of the solid content in the catalyst component was 3.03% by weight. The results obtained are as shown in Table 1.

[Brief description of drawings]

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

Claims (1)

[Claims] 1. A suspension of (I) (a) dialkoxymagnesium in (b) a liquid aromatic hydrocarbon at room temperature,
Thereafter, (c) a titanium halide represented by the general formula TiX ₄ (wherein X is a halogen element) is brought into contact with the composition, and the titanium halide is further brought into contact with the composition.
At this time, (d) a diester of an aromatic dicarboxylic acid and (e) a solid catalyst component obtained by contacting with a nonionic surfactant having HLB of 3 to 12; (II) General formula SiRm (OR ' ) _4- m (wherein R is hydrogen, an alkyl group or an aryl group, R'is an alkyl group or an aryl group, and m is 0≤m≤4), and (III) A catalyst for polymerizing olefins, which comprises an organoaluminum compound.