JPS60252608A - Recovery of diluent - Google Patents

Abstract

PURPOSE:A catalyst composed of a solid transition metal catalyst, an organoaluminum compound and an ester is diluted with an inert hydrocarbon to effect the polymerization of an olefin, then the diluent is distilled off, treated with silica gel to enable easy recovery of reusable diluent. CONSTITUTION:The polymerization of propylene or a mixture thereof with an olefin in polymerization tank is carried out in the presence of a catalyst which is composed of a solid transition metal catalyst containing a titanium halide, an organoaluminum compound and an ester, ether, orthoester or glycol ether boiling over 150 deg.C, using an inert hydrocarbon boiling at 60-140 deg.C under normal pressure. The resultant polymer slurry is treated in the catalyst deactivator to deactivate the catalyst and the inert hydrocarbon is distilled with the heating tube D and the drier H to collect the fraction boiling lower than 140 deg.C, free from the fraction boiling over 150 deg.C. The fraction is treated with silica gel to recover the diluent to be reused.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing propylene or a (co)polymer of propylene and olefin by a bulk polymerization method or a gas phase polymerization method using propylene itself as a polymerization medium, and inert carbon used as a catalyst diluent. This invention relates to a method for recovering a hydrogen hydride compound.

Recent improvements in catalyst performance have made it possible to obtain excellent catalysts, while advances in polymerization methods have led to advances in methods that do not use inert hydrocarbon compounds as multipolymerization media, such as bulk polymerization methods or gas phase polymerization methods. , processes are emerging that require little recovery of inert hydrocarbon compounds. However, although the amount of inert hydrocarbon compound used is extremely small compared to the polyolefin obtained, at least the catalyst must be diluted with an inert hydrocarbon compound before being charged into the polymerization tank. Furthermore, since inert hydrocarbon compounds are charged to specific parts such as valves to prevent blockages, the amount of inert hydrocarbon compounds used is 90%, which is easy from a resource-saving perspective. It is desirable to collect and reuse it in a suitable manner. In response to this, the present inventors discovered that it could be easily recovered by first distilling it using a specific method, and filed an application (Patent Application No. 57).
-91287). However, when the inert hydrocarbon compound recovered by this method is used in the synthesis of a solid transition metal catalyst or as a diluent, there is a problem in that it deteriorates the performance of the solid transition metal catalyst. When polymerizing propylene, a solid transition metal catalyst is mixed with an organoaluminum compound, but the mixed catalyst deteriorates over time and its catalytic performance deteriorates. It is common practice to mix or use the mixed product in about one day at most.

On the other hand, solid transition metal catalysts are inconvenient and dry to handle continuously in a dry state, so they are diluted with an inert hydrocarbon compound and stored in a slurry state. Inert hydrocarbon compounds are utilized in the process. Since it is not a good idea to prepare different inert hydrocarbon compounds for each of the above-mentioned uses, the same one is usually used. It is hoped that there will be no problems.

The inventors of the present invention have conducted intensive studies on a method for easily recovering inert hydrocarbon compounds by solving the above problems, and have found that it is possible to recover inert hydrocarbon compounds that can withstand reuse by performing a specific treatment. They discovered this and completed the present invention.

An object of the present invention is to provide a method for recovering for reuse at least an inert hydrocarbon compound used as a catalyst diluent in a polymerization process using propylene itself as a medium.

The present invention provides a catalyst comprising a solid transition metal catalyst containing titanium halokenide, an organoaluminum compound, and a compound selected from esters, ethers, orthoesters, and halichol ethers having a boiling point of 150°C or higher measured at normal pressure. The polymerization method uses propylene itself as a medium, using a catalyst diluent with a boiling point of at least 60% as measured at normal pressure.
In a method of polymerizing propylene or zolopylene and olefin using an inert hydrocarbon compound at ~140°C, and recovering and reusing the inert hydrocarbon compound, the boiling point of the inert hydrocarbon compound measured at normal pressure is 150°C. The present invention relates to a method for recovering a diluent, which comprises separating it by distillation as a fraction of 140° C. or lower that does not contain diesters, ethers, orthoesters, or glycol ethers, treating it with silica dal, and recovering it for reuse.

The present invention also provides a catalyst comprising a solid transition metal catalyst containing a titanium halide, an organoaluminum compound, and a compound selected from esters, ethers, ordiesters, or glycol ethers having a boiling point of 150°C or higher measured at normal pressure. The polymerization method uses propylene itself as a medium, and the boiling point measured at normal pressure as a catalyst diluent is at least 6.
In a method of polymerizing zolopylene or propylene and olefin using an inert hydrocarbon compound at 0 to 140°C, and recovering and reusing the inert hydrocarbon, the boiling point of the inert hydrocarbon measured at normal pressure is 150°C or higher. A method for recovering a diluent, which comprises separating it by distillation as a fraction below 140°C that does not contain diesters, ethers, ordiesters or halycol ethers, washing with water, treating with silica dal, and recovering for reuse. Regarding.

In the present invention, the solid transition metal catalyst containing titanium halide includes one containing titanium halide as an active transition metal component and also containing aluminum halide, or magnesium halide. Alternatively, titanium halide may be supported on a carrier such as silica or alumina. Furthermore, ester, ether,
It may also contain compounds such as orthoesters, amines, and amides.

In the present invention, the organoaluminum compound is not particularly limited, but preferably trialkylaluminum such as triethylaluminum, trizolobylaluminum, triisobutylaluminum, dialkylaluminum monohalide such as diethylaluminum chloride, dipropylaluminum chloride, ethyl Alkylaluminium sesquihalodanides such as aluminum sesquichloride, alkylaluminum dino-10-glycanides such as ethylaluminum dichloride, or c: r-
aluminum sulfate, etc. are used.

In the present invention, esters, ethers, orthoesters, or glycol ethers having a boiling point of 150° or more measured at normal pressure are used as stereoregularity improvers or catalyst activity improvers. If the boiling point measured at normal pressure is lower than 150°, separation from inert hydrocarbon compounds will not be easy, which is undesirable. Specific compounds include monoalkyl esters, dialkyl esters of aromatic carboxylic acids, aromatic ethers or di- or triethylene glycol, diethers of propylene glycol, aromatic orthoesters,
) Also, monoalkyl ethers of triethylene glycol, zoropylene glycol, etc., more specifically benzoic acid, toluic acid, anisic acid.

Methyl, ethyl, propyl, butyl naphthylate, etc. (
D ester; ethers such as diphenyl ether, dibenzyl ether, amyl ether; methyl orthobenzoate, ethyl orthobenzoate, methyl orthotoluate,
Ethyl orthotoluate.

Orthoesters such as methyl orthoanisate, methyl orthoanisate; diethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether.

Triethylene glycol dipropyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol monoinzolobyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether Examples include.

In the present invention, the boiling point of the inert hydrocarbon compound at normal pressure must be 60 to 140°C.
If it is too low, it will not be easy to separate it from zoropyrene, and 140
If the temperature is higher than 0.degree. C., separation from the above-mentioned esters, ethers, ordiesters or glycol ethers is not easy.

Specific examples of inert hydrocarbon compounds include hexane, hezotane, octane, benzene, and toluene.

Mention may be made of xylene, ethylbenzene and mixtures thereof.

The inert hydrocarbon compound to be recovered in the present invention is either a solid transition metal diluted into a slurry and charged into the polymerization reaction zone, or a slurry used to dilute an organoaluminum compound and charged. In particular, solid transition metals may be charged in slurry form to charge solid transition metals into the polymerization zone. Diluting inert hydrocarbon compounds are essential.

The polymerization reaction is carried out by a bulk polymerization method using propylene itself as a liquid medium or a gas phase polymerization method in which substantially no liquid medium is present, and the amount of inert hydrocarbon compound used is the monomer used or the resulting polymer. The present invention is effective when the amount is extremely small compared to . In other words, if a large amount of inert hydrocarbon compound is used, the amount of polymerization-inhibiting components produced during polymerization will probably be relatively small compared to the amount of inert hydrocarbon compound, and it will have a substantially negative effect on catalyst performance. This is because it is easy to separate by a distillation operation into an amount that does not give a large amount of carbon dioxide, and in some cases, it is more cost-effective to carry out the distillation separation more precisely than by using an adsorbent as in the present invention.

The inert hydrocarbon compounds recovered in the present invention include those recovered as high-boiling components from recovered monomers such as ethylene and propylene, or high-boiling components recovered during drying of polypropylene powder. . Of course, in order to use these recovered inert hydrocarbon compounds as a diluent in the production of solid transition metal catalysts, it is possible to perform very precise rectification and separate the hydrocarbon compounds. To do this, it is necessary to remove a large amount of low-boiling and high-boiling components using a distillation column with a large number of stages, which results in a low yield of recovered purified hydrocarbon compounds and high refining costs. In the method of the present invention, esters, ethers, ordiesters, or glycol ethers at 150°C or higher are simply separated in a distillation column with a number of stages sufficient to remove them as high-boiling components, and then the high-boiling components are separated into a column packed with silica coals. by contact treatment, such as by passing the inert hydrocarbon compound from which the high-boiling components have been removed, or, more preferably, by contacting the inert hydrocarbon compound from which the high-boiling components have been removed with water and then treatment with silica gel. Available inert hydrocarbon compounds can be recovered.

The distillation method for obtaining a fraction containing no esters, ethers, ordiesters or glycol ethers at a temperature of 150° C. or higher may be either a continuous method or a batch method.
Usually, several stages are sufficient.

When washing with water prior to treatment with silica shell, the fraction obtained in the above procedure may be washed with water in batches in a mixing tank and then left to separate, or alternatively, it may be washed with water using a washing tower and then separated into liquids. The inert hydrocarbon compounds recovered in this way are then treated with silica gel. be done. As the silica gel to be used, those commercially available for drying can be used as they are, and depending on the case, they may be heated after being heated at 150 to 350°C. The shape may be of any shape, but the method of filling a packed column and continuously passing the recovered inert hydrocarbon compound is easy to operate and does not require special equipment, making it more efficient. It is convenient to use a spherical one as there is less pressure loss. Other processing methods include
This can also be done by mixing in a tank equipped with a stirrer.

The method of the present invention is applicable not only to the polymerization of propylene alone, but also to copolymerization and block copolymerization with ethylene or butene-1.

By using the method of the present invention, inert hydrocarbon compounds can be efficiently recovered and reused, which is extremely valuable industrially.

The present invention will be further explained with reference to Examples below.

Experimental Example 1 (4) Production of solid transition metal catalyst: A vibratory mill equipped with two grinding pots each having an internal volume of 900 m1 containing 80 steel balls with a diameter of 12 mm was prepared.

Into this pot, under a nitrogen atmosphere, 1 part magnesium chloride 30ml, 1 part ethyl orthoacetate 3ml, and 1,2-dichloroethane 6d were added and allowed to stand for 40 hours. From the crushed product obtained by repeating this operation twice, 27
! The mixture was stirred and contacted with 500 mJ of titanium tetrachloride at 80°C for 2 hours in a round bottom flask, and then left to stand, and the supernatant liquid was removed. Next, 11 ml of n-hebutane was added, stirred at room temperature for 15 minutes, allowed to stand, and the washing operation of removing the supernatant liquid was repeated seven times, and then 500 ml of n-hebutane was further added to prepare a solid transition metal catalyst slurry.

(B) (i) Preparation of catalyst slurry; n-heethane 501
502 as the solid content of the solid transition metal catalyst slurry.
, diethylaluminum chloride 214TrLl.

100 ml of methyl toluate was added to prepare a catalyst slurry. Separately, 133 v+1 of triethylaluminum was diluted with 20 J of n-hebutane.

(ij) Polymerization reaction and n using the polymerization apparatus shown in Figure 1
- Recovery of hebutane was carried out. A is a polymerization reactor with an internal volume of 5001, and the slurry obtained by polymerization in JA passes through line 5 and bonde B to autoclay; 7"C (inner volume 2
00A') and a portion of the slurry is circulated to A.

In C, the catalyst deactivator (triethylene glycol monomethyl ether) is processed, and the slurry is discharged from 6, and the medium (zolopyrene and n-hebutane) in the thick part of the heating tube is separated by cyclone G. is sent to H for further drying. Drying is carried out by introducing propylene heated to 90°C from 14, and propylene and n-
Hebutane, etc. is sent to heat exchanger F through line 8, and the
9/crn2-gauge The recovered material is cooled and liquefied at 30°C and sent to the tanker via line 10. On the other hand, line 7
The vapor mainly composed of propylene taken out is cooled to 0.1 kg/an2-)r''-di 30°C in heat exchanger E, and the liquefied recovered material is sent to tank L via line 9. Gas that does not liquefy are lines 11, 12 and 1 respectively
3 and sent to the propylene recovery system.

Polymerization reactor A contains a catalyst slurry (32% as a solid catalyst).
/hour) (line 3) 1 as triethylaluminum
3 ml 7 hours (line 4) and 80 kl propylene
? / hour (line 2) and polymerized at 70°C. At this time, for flushing the pump and valves, use 5 liters of n-hebutane.
1/hour was also charged. On the other hand, polymerization slurry 1dA and 5c
At C, triethylene glycol monomethyl ether (line 1) is sent to IQ at a rate of 80 kg/hour.
The feed catalyst was deactivated at Oml/hr. Deactivated slurry is discharged from C at a rate of 80 kg/hour, and approximately 30 kl of powder is discharged from dryer H. /hour, while tank I collected liquid at a rate of 9.611/hour. The recovered liquid, which consists mostly of n-hebutane, is heated to 40°C and a small amount of nitrogen is introduced to remove propylene, and then distilled in a distillation column with 5 theoretical plates to remove low-boiling substances. The distillate was taken out from the pot temperature at 170°C until the temperature at the top of the distillation column reached 100°C. Methyl toluate is contained in the distilled n-hebutane.

Triethylene glycol monomethyl ether was not detected. The yield of the distillate was 91% based on the liquid taken out from Tank I.

(C) Treatment of recovered n-hebutane: (1) Treatment with silica gel; Silica gel 109 was added to recovered n-hebutane 11, stirred for 5 minutes, and then filtered.

(11) After adding 201 nl of water to 1 ton of recovered n-hebutane and stirring (5 minutes), the aqueous layer was removed, and silica gel 102 was added to the n-hebutane layer, stirring (5 minutes), and filtering.

After treatment with only 20 ml of Oi water, nitrogen was introduced to reduce the water content to 5 ppm or less.

Gv) @Recovered n-hebutane as is.

(2) Each of the above (1), (i), orb,
Using n-hebutane treated with (IV), a solid transition metal catalyst slug IJ- was produced in the same manner as in section (4) (however, the pulverized product was on a scale of 102).

(g) Polymerization reaction: Polymerization was carried out using the solid transition metal catalyst slurry obtained in (2) and that obtained in (4) as a comparison. The polymerization reaction was carried out in an autoclave with an internal volume of 51 cm, containing 30 cm of solid transition metal catalyst, 0.06 d of methyl toluate,
Diethylaluminum chloride Q, 128m11)
0.081 Ll of ethylaluminum, n-hebutane for dilution (all using the fresh n-hebutane used in A))
Mix and charge 5ON, then add 9 to 1.5 propylene.
After adding 1.5 Nt of hydrogen and polymerizing at 75°C for 2 hours, unreacted propylene was purged and drying was carried out under reduced pressure at 60°C to obtain a powder (6 hours at 20 mHg).

Experimental Example 2 Experimental Example 1 (
Polymerization was carried out in the same apparatus as B).

As the catalyst slurry, the above titanium trichloride 100f and toluene 1001. Diethyl aluminum chloride 80O
Mix N, charge 50Of zorogylene, and heat at 40℃ for 1
The mixture was stirred for an hour to polymerize 1 υ5 f of propylene of titanium trichloride. Next, 0.5 ml of diethylene glycol monoisopropyl ether was added to form a catalyst slurry. Experimental Example 1 except that this catalyst slurry was used as a solid transition metal catalyst for 72 hours/hour, and triethylaluminum was not charged.
(B) Polymerization was carried out in the same manner as in (11) using a pump and toluene for flushing the pulp. Tank■
Liquid was recovered at 12.81/hour. The majority of this recovered liquid is toluene. Zolopyrene is removed by heating it to 40℃ and introducing a small amount of nitrogen, and distilling it in a similar distillation column until the temperature reaches 177℃ at the pot temperature and 112℃ at the top of the distillation column. The distillate was taken out. The yield of the distillate was 87% based on the liquid taken out from the tank.

The recovered toluene was recovered in the same manner as in Experimental Example 1 (C) (i), (width, Obtained toluene.

10 titanium trichloride catalyst for each recovered toluene.
0? /l was added, stirred and kept for 20 hours, and the catalyst slurry was used for polymerization. 100 m9 of titanium trichloride, 0.8 d of diethyl aluminum cumylide.

A catalyst slurry consisting of 100 mJ of toluene for dilution (however, fresh toluene used for photopolymerization was used) was charged, and propylene 1. , 5 kg, 3 Nt hydrogen, 70
Polymerization was carried out at °C for 3 hours to obtain a powder in the same manner as in Experimental Example 1-E). The results are shown in the table.

[Brief explanation of drawings]

Figure 1 shows the flow of the process used for polymerization, A: polymerization tank, B: pump, C: deactivation tank, D, E. F: heat exchanger, G: cyclone, H: dryer, l: tank, J + J': valve, 1; deactivation side charging line,
2; Propylene charging line, a, a; Catalyst charging line,
5; Slurry circulation line, 6; Slurry discharge line, 7
, 8; Recovery steam line, 9, 10; Recovery liquid line, 11
, 12.13: uncondensed gas line, 14: drying gas charging line, 15: drying powder discharge line. −to ■tsusu

Claims (1)

[Claims] 1) A solid transition metal catalyst containing a titanium halide, an organoaluminum compound, and a boiling point of 150 as measured at normal pressure.
By a polymerization method using propylene itself as a medium in the presence of a catalyst consisting of a compound selected from esters, ethers, orthoesters, or glycol ethers, the boiling point measured at normal pressure as a catalyst diluent is at least 60 to 14 °C.
In a method of polymerizing propylene or olefin with an inert hydrocarbon compound at 0°C and recovering and reusing the inert hydrocarbon compound, the boiling point of the inert hydrocarbon compound measured at normal pressure is 150°C. After distillation and separation as a fraction below 140°C that does not contain the above esters, ethers, orthoesters, or glycol ethers,
A method for recovering a diluent characterized by treating it with silica gel and recovering it for reuse. 2) A solid transition metal catalyst containing a titanium halide, an organoaluminum compound, and a boiling point of 150 as measured at normal pressure.
A polymerization method using propylene itself as a medium in the presence of a catalyst consisting of a compound selected from esters, ethers, orthoesters, or glycol ethers with a boiling point of at least 60 to 60 as measured at normal pressure as a catalyst diluent. 140
An ester in which the boiling point of the inert hydrocarbon measured at normal pressure is 150°C or higher, in a method in which propylene or propylene and olefin are polymerized using an inert hydrocarbon compound at a temperature of 150°C, and the inert hydrocarbon is recovered and reused. A method for diluting and recovering an agent, which comprises distilling and separating the fraction as a fraction of 140° C. or lower that does not contain ether, orthoester, or glycol ethers, washing with water, treating with silica gel, and recovering for reuse.