JPS62257905A - Catalyst for olefin polymerization - Google Patents

Abstract

PURPOSE:To provide a catalyst acting in high activity when applied to olefin polymerization leading to production of stereoregular polymer with symmetrical particle size distribution in high yield, prepared from a silicon compound, organoaluminum compound, and a catalytic component formed by heating treatment of a specific solid composition. CONSTITUTION:The objective catalyst can be prepared from (A) a catalytic component obtained by treatment on heating to normally to >=30 deg.C in the presence of a liquid aliphatic hydrocarbon at normal temperature, of a solid composition formed by mutual contact between dialkoxymagnesium (e.g. diethoxymagnesium), aromatic dicarboxylic acid diester (e.g. dimethyl phthalate), aromatic hydrocarbon (e.g. toluene, benzene) and titanic halide (e.g. TiCl4), (B) a silicon compound of formula (R is H, alkyl or aryl; R' is alkyl or aryl; 0<=m<=4) (e.g. phenylalkoxysilane), and (C) an organoaluminum compound. It is preferable that 1-1,000mol of the component C per mole of the Ti in the component A and 0.005-0.5mol of the component B per mole of the component C are used, respectively.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention produces stereoregular polymers that act with high activity and have a uniform particle size distribution in extremely high yields when subjected to the polymerization of olefins. The high-performance catalyst that can be obtained is more specifically a solid composition obtained by contacting dialkoxymagnesium, a diester of an aromatic dicarboxylic acid, an aromatic hydrocarbon, and a titanium halide with an aliphatic hydrocarbon that is liquid at room temperature. The present invention relates to a catalyst component for olefin polymerization obtained by heat treatment in the coexistence of an olefin polymerization catalyst component, a silicon compound, and an organoaluminium compound.

[Conventional technology]

Conventionally, as a highly active catalyst for polymerizing olefins, a combination of a solid titanium halide and an organoaluminum compound as a catalyst component has been well known and widely used. Polymer yield per titanium inside! (hereinafter referred to as the catalyst component and the polymerization activity per titanium in the catalyst component) is low, so a so-called deashing step to remove the catalyst residue was inevitable. This deashing process uses a large amount of alcohol or chelating agent, so recovery equipment or regeneration equipment is essential, and there are many problems related to resources, energy, etc.
For those skilled in the art, this was an important issue that needed to be solved as soon as possible. In order to eliminate this complicated deashing step, many studies have been made and proposals have been made to increase the polymerization activity of the catalyst component, particularly titanium, in the catalyst component.

In particular, a recent trend is to support transition metal compounds such as titanium halides, which are active ingredients, on carrier materials such as magnesium chloride, and when used in the polymerization of olefins, the polymerization activity per titanium in the catalyst component can be dramatically increased. I've seen many suggestions for increasing it.

[Problem that the invention seeks to solve]

However, the chlorine contained in magnesium chloride, which is the main carrier material, has the same disadvantage as the halogen element in titanium halides, which has a negative effect on the polymer produced, and for this reason, the effect of chlorine is virtually ignored. However, there remained unresolved issues such as the need to have as high an activity as possible, or the need to keep the concentration of magnesium chloride itself low.

The present inventors have developed a patent application filed in Japanese Patent Application No. 1983-1-1 with the aim of reducing the residual chlorine in the produced polymer while maintaining a high degree of polymerization activity per catalyst component and the yield of a stereoregular polymer.
No. 200454, we proposed a method for producing a catalyst component for olefin polymerization, and achieved the intended purpose. Furthermore, when polymerizing olefins, especially stereoregular polymerization of propylene, 1-butene, etc., is carried out industrially, it is common to coexist an electron-donating compound such as an aromatic carboxylic acid ester in the polymerization system. It is essential for catalysts that use a catalyst component having a carrier as a carrier in combination with an organoaluminum compound. However, this aromatic carboxylic acid ester imparts a characteristic ester odor to the produced polymer, and its removal has become a major problem in the industry.

In addition, in so-called highly active supported catalysts, such as catalysts using catalyst components using magnesium chloride as a carrier,
Although the activity at the initial stage of polymerization is high, the deactivation is large, which causes problems in process operation, and it is almost impossible to use it practically in cases such as block copolymerization where a longer polymerization time is required. In order to improve this point, for example, in JP-A-54-945?0, magnesium dihalide is used as a starting material and the catalyst component is FA ff
However, a method for polymerizing olefins in combination with an organoaluminum compound, an organic carboxylic acid ester, a compound having an M-0-R group, etc. has been proposed, but since the organic carboxylic acid ester is used during polymerization, the formation of The problem of the odor of the polymer has not been solved, and as can be seen from the examples, it requires extremely complicated operations, and it has not been possible to obtain a product that is practically sufficient in terms of performance and durability of activity. I can't say that it is.

In addition, in industrial polymerization equipment, it is sometimes necessary to feed the catalyst into a high temperature polymerization tank, and conventional supported catalysts have significantly higher performance in such cases, especially in terms of activity, stereoregularity, and bulk specific gravity. It is known that there is a decrease in This is a major problem, especially in so-called continuous slurry polymerization using organic solvents, and there has been a strong demand for improvement in this field.

The inventors of the present invention have arrived at the present invention as a result of intensive research to solve the problems remaining in the prior art, and propose it to the strings.

[Means for solving problems]

That is, the features of the present invention are as follows: (1) A compound obtained by contacting (a) dialkoxymagnesium, (b) diester of aromatic dicarboxylic acid, (c) aromatic hydrocarbon, and (d) titanium halide. (e) a catalyst component obtained by heat-treating the solid composition obtained in the presence of a liquid aliphatic hydrocarbon at room temperature; (It) general formula SiRm(OR')4-ll, (wherein R is hydrogen, alkyl or aryl group, R' is an alkyl group or an aryl group, and m is 0≦m≦4) (hereinafter sometimes simply referred to as a silicon compound); ) An object of the present invention is to provide a catalyst for polymerizing olefins comprising an organoaluminum compound.

The dialkoxymagnesium used in the present invention includes jetoxymagnesium, dibutoxymagnesium, diphenomagnesium, dipropoxymagnesium, di-poxymagnesium, di-tert
-butoxymagnesium, diisopropoxymagnesium, etc., among which dialxymagnesium and dipropoxymagnesium are preferred.

The diester of aromatic dicarboxylic acid used in the present invention is preferably a phthalic acid diester, such as dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diimbutyl phthalate, cyamyl phthalate, diisoamyl Examples include phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate, and ethyl propyl phthalate.

The aromatic hydrocarbon used in the present invention is preferably an aromatic hydrocarbon that is liquid at room temperature, such as toluene, O-
Examples include xylene, m-xylene, p-xylene, benzene, ethylbenzene, flobylbenzene, and trimethylbenzene.

The titanium chlorides used in the present invention include TiC4, TiBr4. Examples include TiI4, among which TiC44 is preferred.

The aliphatic hydrocarbons that are liquid at room temperature used in the present invention are preferably aliphatic hydrocarbons having 5 to 15 carbon atoms.

The silicon compound used in the present invention,
Examples include phenylalkoxysilane and alkylalkoxysilane. Furthermore, examples of phenylalkoxysilane include phenyltrimethoxysilane, phenyltriethoxy 7rane, phenyltripropoxysilane, phenyltriynegloboxysilane, diphenyldimethoxysilane, diphenyljethoxysilane, and alkylalkoxysilane. Examples include tetramethoxysilane, tetraethoxysilane, trimethoxyethylsilane, trimethoxymethylsilane, trimethoxymethylsilane, ethyltriethoxysilane, and ethyltriisopropoxysilane.

When obtaining the solid composition of the present invention, the proportions and contact conditions of each raw material are arbitrary as long as they do not adversely affect the performance of the catalyst component to be produced, and are not particularly limited. Dialkoxymagnesium 11
On the other hand, the diester of aromatic dicarboxylic acid is 101-2
f.

Preferably 0.1-1? The titanium halide has a Q of 12 or more, preferably 1f or more. Further, the aromatic hydrocarbon can be used in any proportion, but it is preferably in an amount that can form a suspension.

Furthermore, the contact between each raw material is usually carried out at a temperature between 0°C and the boiling point of the titanium halide used for up to 100 hours.
It is preferably carried out for 10 hours or less.

At this time, the order and method of contacting each raw material are not particularly limited, and any suitable method can be selected.

It is also possible to repeatedly contact the solid composition obtained after the above-mentioned contact with the titanium halide, and it is also possible to wash it using an organic solvent such as n-hebutane.

The heat treatment of the solid composition obtained as described above was performed on the solid composition 1? The heating is usually carried out at 50° C. or higher for 1 minute or more, preferably 5 minutes or more, in the presence of an aliphatic hydrocarbon of 0.15′ or higher.

At this time, it is also possible to perform the heat treatment under increased pressure or reduced pressure.

The catalyst component produced as described above is combined with the silicon compound and organic albanium compound to form a catalyst for olefin polymerization.

The organoaluminum compound used is used in a molar ratio of 1 to 1000 per mole of titanium atoms in the catalyst component, and the silicon compound is used in a molar ratio of 1 or less, preferably o, It is used in the range of oos to α5.

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. The polymerization temperature is 20
The temperature is 0°C or lower, preferably 100°C or lower, and the polymerization pressure is 1
00IK9/i-G or less, preferably 50 to 97-G
It is as follows.

The olefins to be homopolymerized or copolymerized using the catalyst produced by the method of the present invention include ethylene, propylene,
1-butene, etc.

〔Effect of the invention〕

When olefins are polymerized using the catalyst component obtained according to the present invention, the catalyst has extremely high activity, so the amount of catalyst residue in the resulting polymer can be kept to an extremely low level, and the amount of residual chlorine is very small. Therefore, the influence of chlorine on the produced polymer can be reduced to such an extent that no deashing step is required at all.

Chlorine contained in the produced polymer not only causes corrosion of equipment used in processes such as granulation and molding, but also causes deterioration and yellowing of the produced polymer itself, but this can be reduced. has extremely important meaning for those skilled in the art.

Furthermore, the present invention is characterized by not only solving the major problem of odor of the produced polymer by not using an aromatic carboxylic acid ester during polymerization, but also improving the activity per unit time of the catalyst over the course of polymerization. The present invention aims to solve the essential drawbacks of so-called high-activity supported catalysts, in which the activity is significantly reduced due to aging, and to provide a catalyst that can be practically applied not only to homopolymerization but also to copolymerization.

Conventionally, in the industrial production of olefin polymers, it has been common to allow hydrogen to coexist during polymerization from the viewpoint of MI control, etc., but a catalyst using a catalyst component having the above-mentioned salt 1 hismagnesium as a carrier is In the coexistence of hydrogen, the activity and stereoregularity were significantly reduced.

However, when olefins are polymerized in the presence of hydrogen using the catalyst obtained according to the present invention, the activity and stereoregularity hardly decrease even when the MI of the produced polymer is extremely high. Such an effect is of great benefit to those skilled in the art.

In addition, in industrial polymerization equipment, it is sometimes necessary to feed the catalyst into a high-temperature polymerization tank, and conventional supported catalysts have significant performance problems in such cases, especially in terms of activity, stereoregularity, and It is known that bulk specific gravity etc. decrease. This is a big problem especially in so-called continuous slurry polymerization using organic solvents, and there has been a strong demand for improvement in this field, but the catalyst of the present invention satisfactorily solves this problem.

〔Example〕

The present invention will be specifically explained below using Examples and Comparative Examples.

Example 1 Preparation of catalyst components〉 A 20-liter container fully purged with nitrogen gas and equipped with a stirrer
Jetoxymagnesium 10F and toluene 80- were charged into a round bottom flask of 0- to make it cloudy, then this suspension KTiC420- was added, and the temperature was raised to 90°C to dissolve dibutyl phthalate 2.7-. Add and further heat up to 1
Allow to react at 15°C for 2 hours with stirring. After completion of reaction 9
Wash twice with 100 d of toluene at 0°C, add new toluene 8O-1TiC't, 20- and wash at 115°C for 2
The reaction was allowed to take place while stirring for a period of time. After the reaction was completed, the mixture was washed 10 times with 200° C. of n7 hebutane at 40° C., and then dried under reduced pressure to obtain a solid composition. At this time, the titanium content of the solid composition was 2.61% by weight. Next, thoroughly fill the solid composition with nitrogen gas! The mixture was placed in a round-bottomed flask with an internal volume of 200 mm and equipped with a stirrer, and 30 mm of n-hebutane was added thereto and heated at 100° C. for 1 hour to obtain a catalyst component.

Polymerization> Into an autoclave equipped with a stirrer and having an internal volume of 2-OL that was completely purged with nitrogen gas, 700-g of n-hebutane was charged, and while maintaining the nitrogen gas atmosphere, 500- of triethylaluminum was added.
01119, phenyltriethoxysilane and 64 μm were charged. Thereafter, the temperature was raised to 80°C and the catalyst component was added to 1 [L
19 of OJ and 120 of hydrogen gas were charged, and polymerization was carried out for 4 hours while maintaining a pressure of 97.G while introducing propylene gas. After the polymerization was completed, the obtained solid polymer was separated, heated to 80° C., and dried under reduced pressure.

On the other hand, the amount of polymer dissolved in the polymerization solvent after condensing the F solution is (
A), and the amount of solid polymer is (B). Further, the obtained solid polymer was extracted with boiling n-hebutane for 6 hours to obtain a polymer insoluble in n-hebutane, and this amount was designated as (c).

The polymerization activity (c) per catalyst component was expressed by the formula and the yield of the crystalline polymer (g)) was expressed by the formula, and the yield of the total crystalline polymer (t) was determined from the formula. The residual chlorine in the produced polymer is represented by (c)), the M concentration of the produced polymer is represented by (6), and the bulk specific gravity is represented by (1).

The results obtained are shown in Table 1.

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

Example 3 Heat treatment at 100°C for 1 hour in Example 1 was changed to 80°C
The experiment was conducted in the same manner as in Example 1, except that the experiment was conducted for 2 hours. During polymerization, an experiment was conducted in the same manner as in Example 1. The results obtained are shown in Table 1.

Comparative Example 1 The solid composition obtained in Example 1 was used as it was as a catalyst component without being heat-treated. During polymerization, an experiment was conducted in the same manner as in Example 1. The results obtained are shown in Table 1.

Table 1

[Brief explanation of drawings]

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

Claims (1)

[Claims] (1) (I) (a) Dialkoxymagnesium, (b
) A solid composition obtained by contacting a diester of an aromatic dicarboxylic acid, (c) an aromatic hydrocarbon, and (d) a titanium halide is heat-treated in the presence of (e) a liquid aliphatic hydrocarbon at room temperature. Catalyst component obtained: (II) General formula SiRm(OR')_4_-_m (in the formula 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) an organoaluminum compound.