JPH07660B2 - Olefin polymerization catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has a high activity which, when subjected to the polymerization of olefins, acts with high activity and is capable of obtaining a stereoregular polymer in an extremely high yield. The catalyst component and the catalyst, more specifically, the catalyst component for polymerization of olefins obtained by contacting calcium carbonate, fatty acid magnesium, diester of aromatic dicarboxylic acid and titanium halide, olefin polymerization comprising a silicon compound and an organic aluminum compound. The present invention relates to a catalyst for use.

[Conventional technology]

Conventionally, as a catalyst for olefin polymerization having high activity, a combination of a solid titanium halide as a catalyst component and an organoaluminum compound is well known and widely used. Since the yield of the polymer per titanium (hereinafter referred to as the catalyst component and the polymerization activity per titanium in the catalyst component) was low, a so-called deashing step for removing the catalyst residue was unavoidable. 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 trend, when a transition metal compound such as titanium halide which is an active ingredient is supported on a carrier substance such as magnesium chloride and 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.

[Problems to be solved by the invention]

However, chlorine contained in magnesium chloride, which forms the mainstream as a carrier substance, has a drawback that it adversely affects the produced polymer as well as the halogen element in titanium halides. There was an unsolved part such as high activity required, or the need to keep the concentration of magnesium chloride itself low.

The present inventors have aimed to reduce residual chlorine in the produced polymer while maintaining the polymerization activity per catalyst component and the yield of the stereoregular polymer at a high level.
In 107, a method for producing a catalyst component for polymerization of olefins was proposed, and the initial purpose was achieved.

However, in the case of using the above-mentioned catalyst component having magnesium chloride as a carrier, or the catalyst component obtained in the above-mentioned JP-A-59-91107, the polymerization activity per unit time is high at the beginning of the polymerization, but decreases with the passage of the polymerization time. It is large and becomes a problem in process operation, and when it is necessary to prolong the polymerization time such as block copolymerization, it is practically impossible to use.

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, the feature of the present invention is that (A) calcium carbonate, (b) fatty acid magnesium, (c) diester of aromatic dicarboxylic acid, and (d) general formula TiX ₄ (where X is a halogen element). A catalyst component obtained by contacting with a titanium halide represented by the formula (hereinafter sometimes simply referred to as titanium halide); (B) General formula SiR _m (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) (hereinafter sometimes simply referred to as a silicon compound). And (C) an organoaluminum compound for providing a catalyst for olefin polymerization.

There is no particular limitation on the calcium carbonate used in the present invention, and ordinary commercial products can be used.

As the fatty acid magnesium used in the present invention, saturated fatty acid magnesium is preferable.

The diester of aromatic dicarboxylic acid used in the present invention is preferably a diester of phthalic acid or terephthalic acid, for example, dimethyl phthalate, dimethyl terephthalate, diethyl phthalate, diethyl terephthalate, dipropyl phthalate, dipropyl terephthalate, dibutyl phthalate, dibutyl. Examples thereof include terephthalate, diisobutylphthalate, diamylphthalate, diisoamylphthalate, ethylbutylphthalate, ethylisobutylphthalate and ethylpropylphthalate.

Formula TiX ₄ used in the present invention (wherein X is a halogen element.) TiCl ₄ as a titanium halide represented by, TiBr _4, TiI ₄ but like among them TiCl ₄
Is preferred.

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

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

When obtaining the catalyst component in the present invention, the use ratio of each raw material, contact conditions, and the like are optional as long as they do not adversely affect the performance of the produced catalyst component, and are not particularly limited, but usually carbonic acid is used. The diester of the aromatic dicarboxylic acid is in the range of 0.01 to 2 g, preferably 0.1 to 1 g, and the titanium halide is in the range of 0.1 g or more, preferably 1 g or more based on 1 g of calcium and fatty acid magnesium in total.

At this time, the order of contact and the method of contact of the respective raw materials forming the catalyst component are not particularly limited and can be arbitrarily selected.

The composition obtained after contacting each component constituting the catalyst component can be repeatedly contacted with a titanium halide, or can be washed with an organic solvent such as n-heptane.

It is preferable that these series of operations in the present invention are performed in the absence of oxygen and water.

The catalyst component produced as described above has broad peaks in the X-ray spectrum near 2θ = 32 ° and around 50 °, and is used for the polymerization of olefins in combination with the silicon compound and the organoaluminum compound. Form a catalyst. The organoaluminum compound used is used in a range of 1 to 1000 in molar ratio per mole of titanium atom in the catalyst component, and the silicon compound is 1 or less in molar ratio per mole of organoaluminum compound, preferably 0.005 to 0.5. Used in the range of.

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 component of the present invention are ethylene, propylene, 1-butene and the like.

〔The invention's effect〕

When the olefins are polymerized using the catalyst obtained according to the present invention, the resulting polymer has extremely high stereoregularity and, of course, has a very high activity, so that the catalyst in the resulting polymer is The residue can be kept extremely low,
Moreover, since the amount of residual chlorine is so negligible that no deashing step is required at all, the effect of chlorine on the produced polymer can be substantially eliminated.

Chlorine contained in the generated polymer causes corrosion of equipment used in processes such as granulation and molding, and also causes deterioration of the generated polymer itself, yellowing, etc., which can be substantially eliminated. This is extremely important to those skilled in the art.

Further, the feature of the present invention is to solve the essential drawback of so-called highly active supported catalysts, in which the activity per unit time of the catalyst decreases significantly with the progress of polymerization, and not only homopolymerization but also It is to provide a catalyst that can be applied practically even to copolymerization.

Further, in the industrial production of olefin polymers, it is generally said that hydrogen is allowed to coexist at the time of polymerization from the viewpoint of MI control and the like. It had a drawback that the stereoregularity was significantly reduced. However, when the olefins are polymerized in the coexistence of hydrogen using the catalyst obtained according to the present invention, the activity and stereoregularity are almost reduced even when the MI of the produced polymer is extremely high. However, such an effect brings an extremely great benefit to those skilled in the art.

〔Example〕

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

Example 1 [Preparation of catalyst component] 0.5 g of calcium carbonate and magnesium stearate 9.
Transfer 5g to a round-bottomed flask with a capacity of 300ml, which was sufficiently replaced with nitrogen gas and equipped with a stirrer, 1.5ml of dibutyl phthalate and 100ml of TiCl ₄ were added with stirring, the temperature was raised to 110 ° C and the reaction was continued for 2 hours with stirring. Let After the reaction is completed, n-
It was washed 10 times with 100 ml of heptane, 100 ml of TiCl ₄ was newly added, and the mixture was reacted at 110 ° C. for 2 hours while stirring.

After the reaction was completed, it was cooled to 40 ° C, and then 100 ml of n-heptane
The cleaning was repeated, and when chlorine was not detected in the cleaning liquid, the cleaning was completed and the catalyst component was used. At this time, the solid content of the catalyst component was separated, and the titanium content in the solid content was measured and found to be 2.70% by weight.

〔polymerization〕

700 ml of n-heptane was charged into an autoclave with a stirrer having an internal volume of 2.0 l, which was completely replaced with nitrogen gas, and 301 mg of triethylaluminum, 64 mg of phenyltriethoxysilane, and then the above catalyst components were charged while maintaining a nitrogen gas atmosphere. 0.3 mg of titanium atom was charged. Then 120 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 the completion of the polymerization, the solid polymer obtained was separated, heated to 80 ° C. and dried under reduced pressure to obtain 246 g of a polymer. While condensing the liquid
5.2 g of polymer was obtained. The MI of the solid polymer was 7.8.

Example 2 An experiment was conducted in the same manner as in Example 1 except that the polymerization time was 6 hours, and 341 g of a solid polymer was obtained. Meanwhile, the liquid was condensed to obtain 7.2 g of a polymer. The MI of the solid polymer was 6.1.

Example 3 A catalyst component was prepared in the same manner as in Example 1 except that the reaction temperature was 100 ° C. The titanium content in the solid content at this time was 2.89% by weight. An experiment was conducted in the same manner as in Example 1 during the polymerization to obtain 236 g of a solid polymer. Meanwhile, the liquid was condensed to obtain 4.8 g of a polymer. The MI of the solid polymer was 9.8.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining the present invention.

Claims (1)

[Claims] Claims: (A) (a) calcium carbonate, (b) fatty acid magnesium, (c) diester of aromatic dicarboxylic acid and (d) general formula TiX ₄ (wherein X is a halogen element). A catalyst component obtained by contacting a titanium halide with (B) 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 an aryl group). And m is 0 ≦ m ≦ 4), and a catalyst for olefin polymerization, which comprises a silicon compound represented by the formula (2) and (C) an organoaluminum compound.