JPS6125007B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention utilizes at least the following activated titanium components as solid catalysts for stereospecific polymerization of α-olefins.
Manufactured by a manufacturing method consisting of processing steps (1) to (3),
In this case, the present invention relates to a method for separating an inert hydrocarbon solvent (hereinafter simply referred to as a solvent) and a complexing agent from the waste liquid generated from the step (3), and purifying and recovering it for reuse. (1) reducing titanium tetrachloride with aluminum; (2) co-milling the resulting reduced solid with an alkyl aluminum compound in the presence of up to about 10% by weight of ethylene or alpha-olefin; (3) then This is a waste liquid produced in the catalyst preparation process, which involves a modification process using a solvent, a complexing agent, and titanium tetrachloride. In this production method, n-hexane, cyclohexane or n-hexane is used as the solvent.
-Aliphatic or cycloaliphatic hydrocarbons such as heptane are used. In addition, as a complexing agent, di-n
-butyl ether, di-n-amyl ether,
Diisoamyl ether and the like are used. When producing an activated titanium component by this method, it is necessary to recover the solvent and complexing agent from the waste liquid produced in the above treatment step (3) in order to reduce the production cost of the catalyst. An object of the present invention is to provide a method for recovering the solvent and complexing agent from the above-mentioned waste liquid and purifying it to a quality suitable for reuse. In addition to the solvent and the complexing agent, the waste liquid contains titanium tetrachloride, eluted aluminum chloride, and fine titanium trichloride particles. In the method of the present invention, a hydrocarbon waste solvent generated in the Ziegler-Natsuta type catalyst manufacturing process and a waste liquid containing an oxygen-containing organic compound used as a complexing agent in the process are extracted from the solvent and the complexing agent. The steps of recovering each are A) treating the waste liquid with an alkaline aqueous solution, B then separating the oil layer by steam distillation, C further rectifying the oil to separate the hydrocarbon waste solvent and the complexing agent, D. Before reusing the purified complexing agent, 20
This recovery treatment method is characterized by performing adsorption treatment using hydrotalcite calcined at a temperature of -800°C as an adsorbent. One embodiment of the method of the present invention is described below. A type A or AA type titanium trichloride and aluminum trichloride eutectic (hereinafter referred to as reduced solid) obtained by reducing titanium tetrachloride with aluminum.
is co-milled with a small amount of diethylaluminum chloride (eg, 1/10th the weight of the reduced solid) and ethylene (eg, 1/100th the weight of the reduced solid). Milling is conveniently carried out in a vibratory mill. Remove the contents from the grinder and suspend in heptane. Next, diisoamyl ether and titanium tetrachloride are added and stirred. By this operation, most of the aluminum chloride in the reduced solid is eluted. After repeated washing with heptane and decanting, the activated titanium component of the product is obtained. On the other hand, the cleaning solution is mixed with alkaline water to hydrolyze aluminum chloride and titanium chloride. The decomposition liquid is continuously heated and the steam distillation operation is continued until the upper oil layer disappears. The residual liquid contains fine white precipitates. Since the residual liquid is essentially odorless water with a COD value of 20 ppm or less, it is discharged as wastewater after precipitation. During the steam distillation process, first aqueous heptane and a small amount of diisoamyl ether are distilled out, and then an azeotrope of diisoamyl ether and water is distilled out. After liquefying in a condenser, the aqueous layer is separated and the organic layer is passed through a catalytic column. Heptane is obtained from the top of the column, and diisoamyl ether or a mixture of diisoamyl ether and heptane is obtained from the bottom of the column. Heptane is recycled and reused in the catalyst manufacturing process. In addition, the complexing agent recovered from the bottom of the rectification column is not directly returned to the catalyst manufacturing process, but is passed through an adsorption column using hydrotalcite calcined at 200 to 800 degrees Celsius as an adsorbent to remove impurities. Reuse. If this complexing agent subjected to adsorption treatment is used in catalyst production, the polymerization activity will not be lowered. Although it is difficult to identify the components that are adsorbed and removed at this time, colored components and carbonyl compounds are completely removed. When activated alumina, silica gel, or molecular sieve is used as an adsorbent, the removal effect of the above-mentioned colored components and carbonyl compounds is poor. According to the method of the present invention, wastewater can be discharged after being neutralized. Steam distillation also has the advantage that the residual cake is odorless and harmless. The method of the present invention can be applied to a Ziegler-Natsuta type catalyst prepared using at least a hydrocarbon inert solvent and an oxygen-containing organic compound (complexing agent), regardless of whether the catalyst is a supported type or a non-supported type. Well, it can be applied to the waste liquid generated from the catalyst manufacturing process. The present invention will be explained below using examples. Example 1 (Catalyst production) Titanium tetrachloride reduced with aluminum is TiCl _3.1 /3 manufactured by Toyo Stouffer Co., Ltd.
A double chloride with the general formula AlCl ₃ was used. (below
(referred to as AA type titanium trichloride) 50 gr of the above AA type titanium trichloride and 7.2 ml of diethylaluminum monochloride were placed in a grinding pot containing a stainless steel bowl that was purged with nitrogen, and while being crushed, 0.5 gr of ethylene was charged over 30 minutes. death,
Thereafter, grinding was continued for an additional 2 hours. The crushed product is separated from the balls in a nitrogen atmosphere,
Pour into a reaction vessel purged with nitrogen, add 250 ml of dry heptane, and add diisoamyl ether (hereinafter referred to as
50 ml of titanium tetrachloride (abbreviated as EDIA) were added thereto, and the mixture was stirred at 60°C for 2 hours to perform a denaturation treatment. Remove the supernatant liquid by decantation and then 60°C.
The solution was washed five times with 500 ml of dry heptane and combined with the supernatant to obtain 2,735 ml of waste liquid. The components of the waste liquid were as follows. (Weight %) Heptane 94.7% EDIA 1.9% TiCl ₄ 3.4% (Recovery step) Next, the above waste liquid was introduced into a container containing 22 grams of water and 70 grams of caustic soda. Steam distillation was carried out by heating the container and introducing steam. The introduction of steam was stopped when the entire volume of the oil layer and 1.5 liters of water had been distilled out. The water remaining in the container is 2, and the COD value is
It was 16.4ppm. The precipitate was 30 gr after drying. The distillate was separated into oil and water, and the oil layer was rectified in a rectification column with 25 plates. Distillation was continued until the EDIA concentration in the bottom liquid was 50% by weight. The water content of the bottom liquid was 2 ppm, but it was colored pale yellow. This bottom liquid was passed through two adsorption towers in which Kyowa Chemical's synthetic hydrotalcite calcined at 500°C was packed into a column with an inner diameter of 2 cm and a height of 15 cm.
It was passed at a flow rate of ml/min. The resulting liquid was clear and colorless. The heptane distilled from the top of the column was recovered as the main distillate after cutting off the low-boiling front distillate. Moisture is 8ppm, EDIA
was 2ppm. (Catalyst production by reusing recovered heptane and recovered EDIA) Solid pulverized with ethylene charged in the same manner as above
Pour 10g into a nitrogen-purged container, add 38ml of recovered heptane obtained in the recovery process, add 22ml of a 1:1 (weight ratio) solution of EDIA and heptane from the column bottom liquid, and add titanium tetrachloride. 8 ml was added and denatured at 60°C for 2 hours. Remove the supernatant and
Washed five times with 100 ml of recovered heptane. (Polymerization) A SUS-32 autoclave with an internal volume of 5 was sufficiently purged with nitrogen, the catalyst slurry prepared above was sampled to a solid content of 0.1 gr, and 1 ml of diethylaluminium monochloride and 50 ml of heptane were purged with nitrogen. After mixing in a container, the mixture was charged into an autoclave. After replacing the inside of the autoclave with propylene, add liquid propylene while stirring.
1.5Kg was charged, then hydrogen was charged at a gas phase partial pressure of 1Kg/ ^cm2 to adjust the molecular weight, and the temperature was raised to 60℃.
A time polymerization reaction was carried out. After the reaction was completed and unreacted propylene was purged, the resulting white powder was
It was dried under reduced pressure at ℃ for 5 hours. The weight of the obtained polypropylene was 805gr, the bulk density (hereinafter abbreviated as BD) was 0.42gr/ml, and the weight percentage of the obtained polymer that was insoluble in hot heptane (hereinafter referred to as Total II)
96.7%, intrinsic viscosity (hereinafter referred to as "η", measured in tetralin at 135°C) 1.79, and polymerization activity expressed as the weight of polymer (polypropylene) obtained per 1 gram of catalyst per hour: 2683 g polypropylene/hour. It was gr catalyst. In addition, as a result of molecular weight distribution measurement by gel perchromatography, the molecular weight distribution index (D-Mw/
Mn, Mw weight average molecular weight, Mn number average molecular weight) were 7. Regarding the particle size distribution of the polymer, the proportion of powder that did not pass through a 10 mesh sieve (hereinafter referred to as 10 mesh on) was 10.7%, and the proportion of powder that passed through a 200 mesh sieve (200 mesh pass) was 0.4%. A stabilizer was added to the obtained polypropylene powder, mixed in a mixer, pelletized in an extruder, and further extruded in a film forming machine at a temperature of 250°C and a rotation speed of 60 rpm to create a film using the T-die method. The degree of haze was 2.9%. Comparative Example 1 A catalyst was produced and polymerized in the same manner as in Example 1, except that when producing a catalyst using recovered EDIA and recovered heptane, the recovered EDIA was used as a bottom liquid that was not passed through an adsorption column. The results are shown in Table 1. Comparative Example 2 Example 1 except that the adsorbent was changed to activated alumina
A catalyst was prepared in the same manner as above, and polymerization was carried out. The results are shown in Table 1. Comparative Example 3 A catalyst was produced and polymerized in the same manner as in Example 1, except that silica gel was used as the adsorbent. The results are shown in Table 1. Comparative Example 4 A catalyst was produced and polymerization was carried out in the same manner as in Example 1, except that the adsorbent was changed to Molecular Sieve 13X. The results are shown in Table 1.

[Table] Comparative Example 5 Catalyst production was carried out in the same manner as in Example 1, and waste liquid 2750
Got ml. Next, pour the waste liquid into a separatory funnel containing 1.5 g of water and 70 gr of caustic soda and stir. After the aluminum compounds and titanium compounds are completely decomposed, extract the aqueous layer. Add 1.5 g of water to the funnel and stir, then add the aqueous layer. was taken out, and after adding 1 part of water to the funnel and stirring, the aqueous layer was taken out. When the COD of both water layers was measured, it was 135 ppm. Since gel-like suspended matter was present in the oil layer, it was filtered through paper, and the oil layer was collected and rectified. Heptane is recovered from the top of the tower by cutting off low-boiling components, and EDIA is recovered from the bottom of the tower.
- A 1:1 (weight ratio) solution of heptane was collected. Using the recovered heptane and recovered EDIA solution, a catalyst was produced and polymerized in the same manner as in Example 1. Polypropylene 663gr was obtained. BD is 0.40gr/
ml, total II 96.0%, "η" 1.79, activity was 2210 gr polypropylene/hr gr catalyst. The recovered ether is colored yellow, and strong absorption is seen around 1715 cm in the IR spectrum, indicating the presence of carbonyl groups. In this comparative example, by performing steam distillation in the recovery process, it is possible to separate impurities that have no vapor pressure among the impurities that become catalyst poisons, significantly lowering the COD value of wastewater, and removing gel-like substances as a separate operation. This shows that the recovery process of the present invention is extremely effective.

Claims (1)

[Scope of Claims] 1. A hydrocarbon waste solvent generated in the Ziegler-Natsuta catalyst manufacturing process and a waste liquid containing an oxygen-containing organic compound used as a complexing agent in the process. The steps of recovering each are A. The waste liquid is treated with an alkaline aqueous solution. B. The oil layer is then separated by steam distillation. C. The oil is further purified to separate the hydrocarbon solvent and the complexing agent. D. Before reusing the purified complexing agent, 20
A recovery treatment method characterized by performing adsorption treatment using hydrotalcite calcined at a temperature of -800°C as an adsorbent.