JPH0714974B2 - Method for producing columnar polyolefin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a polyolefin having a special shape, and particularly to a method for producing a columnar polyolefin.

[Conventional technology]

Conventionally, many kinds of polyolefins such as polyethylene and polypropylene having various characteristics have been developed.

However, in recent years, there has been an increasing demand for polyolefin having superior new properties.

Further, in the conventional technique, in order to impart a special property or form to polyolefin, it is necessary to add a special substance to the polymer obtained by once polymerizing, and to mold it using a special molding machine. It was. However, these methods require extra steps, which causes a cost increase of products.

[Problems to be solved by the invention]

The present inventors have reached the present invention as a result of conducting research for the purpose of obtaining a polyolefin having new properties from such a viewpoint by a simpler method, that is, a polymerization operation alone,
This is what we propose here.

[Means for solving problems]

That is, the feature of the present invention is that (A) a magnesium compound obtained by reacting (a) calcium carbonate and (b) metallic magnesium with a halogenated hydrocarbon (hereinafter, may be simply referred to as “magnesium compound”). .) And (c) the general formula R ¹ OR ² (wherein R ¹ and R
² is an alkyl group or an aryl group, and may be the same or different. ) Is contacted in an organic compound represented by the formula (hereinafter sometimes abbreviated as ethers), and (d) a diester of an aromatic dicarboxylic acid and (e) a general formula tiX ₄ (wherein X is a halogen element). A catalyst component obtained by further contacting the titanium halide (hereinafter, may be simply referred to as “titanium halide”) represented by the formula (3) with the titanium halide; Another object of the present invention is to provide a method for producing a columnar polyolefin by using a catalyst comprising B) a piperidine derivative and (C) an organoaluminum compound. The polymerization here means homopolymerization and copolymerization.

As the calcium carbonate used in the present invention, a commercially available product can be appropriately selected.

The magnesium compound used in the present invention needs to be a compound obtained by reacting metallic magnesium with a halogenated hydrocarbon. If necessary, the preparation of the magnesium compound in the present invention is carried out by reacting metallic magnesium and a halogenated hydrocarbon in the presence of iodine or an iodine compound at a temperature substantially from 0 ° C. to the boiling point of the halogenated hydrocarbon used. Is preferably carried out until completion.

As the organic compound represented by the general formula R ¹ OR ² used in the present invention, various ethers are preferable, and aliphatic ethers are particularly preferable.

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, diisoamyl phthalate, ethyl. Examples thereof include butyl phthalate, ethyl isobutyl phthalate and ethyl propyl phthalate.

The halogenated hydrocarbon used in the present invention is preferably a chloride of an aliphatic hydrocarbon which is liquid at room temperature.

The titanium halide used in the present invention is
TiCl ₄ , TiBr ₄ , TiI _{4 and the} like can be mentioned, but TiCl ₄ is particularly preferable.

As the piperidine derivative in the present invention, a disubstituted or tetrasubstituted derivative is preferable, and specifically, a general formula (In the formula, R ¹ , R ² , R ³ , and R ⁴ are hydrogen or an alkyl group which may have a substituent, and at least one of R ¹ and R ² is the alkyl group, Further, at least one of R ³ and R ⁴ is the alkyl group.). As a more specific example, Among them, 2,2,6,6-tetramethylpiperidine is preferable.

Examples of the organoaluminum compound in the present invention include trialkylaluminum, dialkylaluminum halides, alkylaluminum dihalides, and mixtures thereof. Among them, trialkylaluminums are preferable, and triethylaluminum and triisobutylaluminum are more preferable. Particularly preferred.

When obtaining the solid catalyst component of the present invention, the use ratio of each raw material constituting the catalyst component is arbitrary and is not particularly limited as long as it does not adversely affect the performance of the catalyst component to be produced. Usually, the magnesium compound is used in an amount of 0.1 g or more, preferably 0.5 g or more, relative to 1 g of calcium carbonate, and an amount of 0.1 g or less is not preferable because the catalytic activity decreases.

The ethers are used in an amount of 1 ml or more per 1 g of the total of calcium carbonate and the magnesium compound. Further, the diester of aromatic dicarboxylic acid is used in the range of 0.01 to 1 g, preferably 0.05 to 1 g, relative to the total 1 g of calcium carbonate and the magnesium compound, and the titanium halide is the total of calcium carbonate and the magnesium compound. It is used in an amount of 0.1 g or more, preferably 1.0 g or more with respect to 1 g.

In obtaining the solid catalyst component used in the present invention, calcium carbonate and the magnesium compound are brought into contact with each other in the ethers, and then excess ethers are dried under reduced pressure, and removed by a method such as excess, It is then preferred to contact the diester of an aromatic dicarboxylic acid and the titanium halide. At this time, the contact between the calcium carbonate and the magnesium compound in the ethers is preferably carried out at a temperature generally from 0 ° C. to the boiling point of the ethers used, and a diester of an aromatic dicarboxylic acid which is subsequently carried out. The contact with the titanium halide is usually carried out at a temperature from 0 ° C. to the boiling point of the titanium halide used for 5 minutes or longer, preferably 10 minutes or longer.

The composition obtained after the contact is further contacted with a titanium halide, but it may be washed with an organic solvent such as n-heptane before and / or after the contact. It is preferable that these series of operations in the present invention are performed in the absence of oxygen and water.

The solid catalyst component produced as described above is combined with a piperidine derivative and an organoaluminum compound to form a catalyst for producing a columnar polyolefin. The organoaluminum compound used is in the range of 1 to 1000 in molar ratio per mole of titanium atom in the catalyst component, and the piperidine derivative is in the range of 0.01 to 0 in molar ratio per mole of the organoaluminum compound.
Used in the range of 5.

Since the catalyst component in the present invention has an extremely low chlorine content in the component, it does not require a deashing step or the like, and thus can be put to practical use without reducing the characteristics of the columnar polyolefin.

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

〔The invention's effect〕

According to the present invention, an extremely high polymerization activity and stereoregularity can be obtained without any additional treatment such as addition of a special substance to a polymer obtained by polymerization and molding of the polymer by a special molding machine. While maintaining the above, columnar polyolefin can be obtained by only one-step polymerization operation. The columnar polyolefin obtained according to the present invention has a very low chlorine content in the catalyst component of the present invention, and therefore, it is expected to have a wide range of applications such as various composite materials without requiring an operation such as deashing.

〔Example〕

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

Example 1 [Preparation of Magnesium Compound] Capacity 20 fully replaced with nitrogen gas and equipped with a stirrer
30 g of magnesium powder, 1.5 g of iodine and 1.5 of n-butyl chloride were placed in a round-bottomed flask, and reacted at the boiling point of n-butyl chloride for 5 hours. After completion of the reaction, the supernatant liquid was removed, the mixture was washed with 500 ml of n-butyl chloride three times, and then dried under reduced pressure to obtain a powdery magnesium compound.

[Preparation of catalyst component]

Fully replaced by nitrogen gas, capacity 500m equipped with stirrer
10 g of the magnesium compound obtained as described above, 8.0 g of calcium carbonate and 100 ml of diethyl ether were placed in a round-bottomed flask having a volume of 1 and reacted for 2 hours at the boiling point of diethyl ether. After completion of the reaction, the supernatant was removed and dried under reduced pressure to obtain a solid composition.

Fully replaced by nitrogen gas, capacity 500m equipped with stirrer
5 g of the solid composition, 1.2 ml of dibutyl phthalate and 200 ml of TiCl ₄ were placed in a 1-liter round bottom flask, and the temperature was raised to 120 ° C. and the reaction was carried out for 2 hours. After the reaction was completed, the supernatant was removed and a new Ti
200 ml of Cl ₄ was added and reacted at 120 ° C. for 2 hours.

After completion of the reaction, the mixture was cooled to 40 ° C and washed 10 times with 200 ml of n-heptane to obtain a catalyst component. At this time, the solid content of the catalyst component was separated and the titanium content of the solid content was measured.
It was 46% by weight.

[Overlap]

700 ml of n-heptane was charged into an autoclave with an internal volume of 20 which was completely replaced with nitrogen gas, and 300 mg of triethylaluminum was added while maintaining a nitrogen gas atmosphere.
70 mg of 2,2,6,6-tetramethylpiperidine and then 0.3 mg of the above catalyst component as titanium atom were charged. Then, 120 ml of hydrogen gas was charged, the temperature was raised to 70 ° C., propylene gas was introduced, and the pressure of 6 kg / cm ² · G was maintained to carry out polymerization for 4 hours. After the completion of the polymerization, the solid polymer obtained was separated and
The mixture was heated to ℃ and dried under reduced pressure. On the other hand, the amount of the polymer dissolved in the polymerization solvent by condensing the liquid is (A), and the amount of the solid polymer is (B). Further, the obtained solid polymer is 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. Residual chlorine in the produced polymer is represented by (G) and MI of the produced polymer is represented by (H). The results obtained are the first
As shown in the table. By the above polymerization, a colorless and transparent columnar polymer having a length of about 2 mm was obtained.

Example 2 An experiment was conducted in the same manner as in Example 1 except that dipropyl phthalate was used instead of dibutyl phthalate. The titanium content in the solid content at this time was 261% by weight. A test was carried out in the same manner as in Example 1 during the polymerization. The results obtained are as shown in Table 1. In addition,
A colorless and transparent columnar polymer having a length of about 2 mm was obtained by the above polymerization.

[Brief description of drawings]

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

Claims (1)

[Claims] Claims: (A) (a) calcium carbonate and (b) a magnesium compound obtained by reacting metallic magnesium with a halogenated hydrocarbon, (c) a general formula R ¹ OR ² (wherein R ¹ and R ² are an alkyl group or an aryl group, and they may be the same or different.) And then (d) a diester of an aromatic dicarboxylic acid and (e) ) A solid catalyst component obtained by contacting the titanium halide represented by the general formula TiX ₄ (where X is a halogen element) with the composition obtained by contacting the titanium halide; ) A method for producing a columnar polyolefin using a catalyst comprising a piperidine derivative and (C) an organoaluminum compound.