JPS643214B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a propylene suspension polymerization method using a recovered solvent, and more particularly to an improvement in the reuse of recovered unrefined solvent in a propylene suspension polymerization method using a Ziegler-Natsuta catalyst. In recent years, with the development of so-called highly active catalysts, the propylene polymerization method using Ziegler-Natsuta catalysts has changed from conventional suspension polymerization using a solvent to bulk polymerization using liquid propylene, which does not use a dispersion medium at all. It is heading toward phase polymerization. The biggest reason why the suspension polymerization method is being replaced by the gas phase polymerization method is not only because the use of solvent, separation and recovery, and purification are expensive as a solvent cost, but also because all polymerization equipment requires the presence of a solvent. Since it has to be designed and manufactured, the equipment becomes complicated,
This is because operating costs also become high. However, at the current state of the art, the suspension polymerization method is relatively suitable for producing a wide variety of products in small quantities, so it cannot be said that it will not be put to practical use in the future. The recycling and reuse of unrefined solvents in propylene suspension polymerization is disclosed in JP-A-49-83784. However, the catalyst used in this method example is
It is titanium trichloride AA, and when reusing the solvent, replenish the purified solvent in the shortage. The main effect is that repolymerization (Note: polymerization using recovered unpurified solvents; the same applies below) compared to initial polymerization (Note: polymerization using a new catalyst and purified solvent; the same applies below).
This means that the decrease in polymerization rate during this process is extremely small. However, even though the titanium-based catalyst component is the same, there are so-called highly active types such as those obtained by reducing titanium tetrachloride with a specific organic compound and further treating it with an electron acceptor, and combining it with an organoaluminum compound. If the unpurified solvent used in the suspension polymerization of propylene is recovered and reused using a catalyst, the yield of crystalline polypropylene (based on the titanium catalyst component) (hereinafter referred to as the yield per catalyst) is It was found that the production rate of solvent-soluble polypropylene (hereinafter referred to as APP) significantly increased. In other words, the above known techniques do not effectively enable the reuse of recovered unpurified solvent (hereinafter sometimes referred to as "recovered solvent") in suspension polymerization of propylene using a highly active catalyst. . The present inventors have made earnest efforts to solve the above technical problem. As a result, it was found that if a highly active catalyst component (note: solid product ()) as shown in JP-A-56-120712 is further treated with an organoaluminium compound and an α-olefin to preactivate the catalyst component, At the same time, propylene is suspension polymerized using the component from which the electron donor has been removed (solid product ()),
When the solvent used in the polymerization is recovered and reused, a reaction product of an electron donor and trialkyl aluminum (sometimes referred to as ED/TAA) is used as a method to prevent the above-mentioned drawbacks in the repolymerization. The present invention was achieved by discovering that it is extremely effective to add as a third component (sometimes referred to as catalyst component (C)). As is clear from the above description, the purpose of the present invention is to reduce the ISOCY The purpose of the present invention is to provide a method for preventing a decrease in APP generation rate and an increase in APP generation rate. Another object is to greatly reduce the cost of recovering and refining the solvent and the consumption of the organoaluminum compound by reusing the recovered solvent. The present invention provides the following features: (1) A solid product () obtained by reacting a reaction product () of an organoaluminum compound and an electron donor with titanium tetrachloride is further reacted with an electron donor and an electron acceptor. A solid product () obtained by treating the solid product () obtained by treating with an organoaluminum compound and an α-olefin
suspension polymerization of propylene in the presence of an inert solvent using a catalyst in combination with an organoaluminum compound and a reaction product of the organoaluminum compound and an electron donor, and the resulting polymerization mixture contains polypropylene as the main component. A method of separating a solid phase portion and a liquid phase portion mainly composed of an inert solvent, adding a new solid product () to the liquid phase portion, and suspending propylene again, and during the repolymerization. 0.01 to 10 mmol, preferably 0.01 to 10 mmol per 1 g of new solid product ()
This is a propylene polymerization method using a recovered solvent, which is characterized by adding 1.0 mmol of an electron donor and a reaction product of trialkylaluminum. Hereinafter, the configuration and effects of the present invention will be explained in detail. The organoaluminum compound (hereinafter sometimes referred to as catalyst component (A)) used in the present invention has the general formula
AlR _o R _{′ o} ′
represents a halogen such as fluorine, chlorine, bromine, and iodine, and n and n' represent any number of O<n+n'3), and specific examples thereof include trimethylaluminum, triethylaluminum, and triethylaluminum. Tri-aluminum such as n-propyl aluminum, tri-n-butyl aluminum, tri-i-butyl aluminum, tri-n-hexyl aluminum, tri-i-hexyl aluminum, tri-2-methylpentyl aluminum, tri-n-octyl aluminum, tri-n-decyl aluminum, etc. Alkylaluminums, diethylaluminum monochloride, di-n-propylaluminum monochloride, di-i-butylaluminum monochloride,
Diethylaluminum monohalides such as diethylaluminium monofluoride, diethylaluminum monobromide, diethylaluminium monoiodide, alkylaluminum hydrides such as diethylaluminum hydride, methylaluminum sesquichloride, ethylaluminum sesquichloride, ethylaluminum dichloride, i- Examples include alkyl aluminum halides such as butylaluminum dichloride, and alkoxyalkylaluminums such as monoethoxy diethyl aluminum and diethoxy monoethyl aluminum can also be used. The organoaluminum compound (A ₁ ) to obtain the reaction product (), combined with the solid product () (A ₂ ), (A 2 ) to obtain the reaction product (G) of the electron donor and the trialkylaluminium. ₃ ) may be the same or different. As the electron donor used in the present invention, various ones are shown below, but it is preferable to mainly use ethers and to use ethers as the other electron donors. Those used as electron donors include organic compounds containing oxygen, nitrogen, sulfur, or phosphorus atoms, such as ethers, alcohols, esters, aldehydes, fatty acids, ketones, nitriles, and amines. , amides, ureas or thioureas, isocyanates, azo compounds,
These include phosphines, phosphites, phosphinites, thioethers, and thioalcohols. Specific examples include diethyl ether, di-
Propyl ether, di-n-butyl ether, diisoamyl ether, di-n-pentyl ether, di-n-hexyl ether, di-hexyl ether, di-n-octyl ether, di-octyl ether, di-n-dodecyl ether, diphenyl Ethers such as ether, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, methanol,
Alcohols such as ethanol, propanol, butanol, pentanol, hexanol, octanol, phenol, cresol, xylenol, ethylphenol, naphthol, methyl methacrylate, ethyl acetate, butyl formate, amyl acetate,
Vinyl butyrate, vinyl acetate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, 2-ethylhexyl benzoate, methyl toluate, ethyl toluate, 2-ethylhexyl toluate, methyl anisate, ethyl anisate, anisic acid Esters such as propyl, ethyl cinnamate, methyl naphthoate, ethyl naphthoate, propyl naphthoate, butyl naphthoate, 2-ethylhexyl naphthoate, and ethyl phenylacetate, aldehydes such as acetaldehyde and benzaldehyde, formic acid, acetic acid, propion acid, butyric acid, oxalic acid,
Succinic acid, acrylic acid, maleic acid, benzoic acid,
fatty acids such as, ketones such as methyl ethyl ketone, methyl isobutyl ketone, benzophenone,
Nitriles such as acetonitrile, methylamine,
Diethylamine, tributylamine, triethanolamine, β(N,N-dimethylamino)ethanol, pyridine, quinoline, α-picoline,
N,N,N',N'-tetramethylhexaethylenediamine, aniline, dimethylaniline and other amines, formamide, hexamethylphosphoric acid triamide, N,N,N',N',N''-pentamethyl-
Amides such as N'-β-dimethylaminomethylphosphoric acid triamide and octamethylpyrophosphoramide, ureas such as N,N,N',N'-tetramethylureas, and isocyanates such as phenyl isocyanate and tolyl isocyanate. azo compounds such as azobenzene, phosphines such as ethylphosphine, triethylphosphine, tri-n-butylphosphine, tri-n-octylphosphine, triphenylphosphine, triphenylphosphine oxide, dimethylphosphine, dimethylphosphine, Phosphites such as n-octylphosphite, triethylphosphite, tri-n-butylphosphite, triphenylphosphite, phosphites such as ethyldiethylphosphite, ethylbutylphosphite, phenyldiphenylphosphinite, diethylthioether , diphenyl thioether, methyl phenyl thioether, ethylene sulfide, propylene sulfide, and other thioethers; ethyl thio alcohol, n-propyl thio alcohol, thiophenol, and other thio alcohols. These electron donors can also be used in combination. The organoaluminum compound (A ₁ ) and electron donor (B ₁ ) are
The reaction product () is obtained by reacting as follows. (Note: A ₁ or B ₁ represents the organoaluminum compound or electron donor used to produce the reaction product ()) This reaction is carried out in the solvent (D) at -20°C.
It is carried out at ~200°C, preferably -10°C to 100°C for 30 seconds to 5 hours. There is no restriction on the order of addition of (A ₁ ), (B ₁ ), and (D), and the ratio of the amounts used is 0.1 to 8 mol, preferably 1 to 8 mol, of the electron donor and 0.5 to 8 mol of the solvent per 1 mol of organoaluminium. 5 is appropriate. Aliphatic hydrocarbons are preferred as solvents. The reaction product () is thus obtained. The reaction product (2) can be subjected to the next reaction in a liquid state (sometimes referred to as reaction product liquid (2)) after the reaction has been completed without separation. The reaction product () is then reacted with titanium tetrachloride to produce a solid product (). The reaction between the reaction product () and titanium tetrachloride (C) is carried out at 0 to 100°C,
Preferably, it is carried out at 10 to 70°C for 5 minutes to 5 hours. Although it is preferred not to use a solvent, aliphatic or aromatic hydrocarbons can be used. (), (C), and the solvent may be mixed in any order, and the total amount must be mixed in 3
It is preferable to finish within the specified time. The amount of each used in the reaction is based on 1 mole of titanium tetrachloride.
The solvent is 0 to 3000 ml, and the reaction product () has a ratio of the number of Al atoms in () to the number of Ti atoms in titanium tetrachloride (Al/Ti) of 0.05 to 10. After the reaction is completed, the liquid portion is separated and removed by filtration or decantation, and after repeated washing with a solvent, the obtained solid product () is carried on to the next step while suspended in the solvent. It may be used, or it may be further dried and taken out as a solid substance for use. For convenience, after the reaction between the reaction product () and titanium tetrachloride,
The reaction solution containing the solid product (2) may be used as it is in the next step. The solid product () is then reacted with an electron donor and an electron acceptor to produce a solid product (). The electron donor (B ₁ ) to obtain the reaction product (), the reaction with the solid product () (B ₂ ), and (B ₃ ) to obtain the reaction product (G) are _each They may be the same or different as long as they satisfy the limitation that they are limited to trialkyl aluminum. The electron acceptor (E) used in the present invention is typified by a halide of an element in groups 1 to 10 of the periodic table. Specific examples include anhydrous aluminum chloride, silicon tetrachloride, stannous chloride, tin chloride, titanium tetrachloride, zirconium tetrachloride, phosphorus trichloride, phosphorus pentachloride, vanadium tetrachloride, antimony pentachloride, and iodine. The most preferred is titanium tetrachloride. Although the reaction between an electron donor and an electron acceptor can be carried out without using a solvent, preferable results can be obtained using an aliphatic hydrocarbon. There is no restriction on the order of addition of solid product (), electron donor, electron acceptor and solvent, and the amounts used are as follows: solid product (), electron donor, electron acceptor and solvent
For 100g, the electron donor is 10g to 1000g, the electron acceptor is 10g to 1000g, and the solvent is 0 to 3000ml, -
Add for 30 seconds to 60 minutes at 10℃~30℃, 30℃~200℃,
It is desirable to react preferably at 50°C to 100°C for 30 seconds to 5 hours. After the reaction is completed, the liquid portion is separated and removed by filtration or decantation, and washing with a solvent is repeated to obtain a solid product (2). The obtained solid product (2) is washed with an inert solvent or washed and dried and then treated with an organoaluminum compound and an α-olefin. The organoaluminum compound used may be the same as the catalyst component (A) described above, but dialkylaluminum monohalides such as diethylaluminum monochloride (DEAC) and alkylaluminum sesquihalides such as ethylaluminum sesquichloride are particularly used. Cheap. The proportion of solid product () and organoaluminum compound used is
Weight ratio of 0.1 to 10, preferably 1.0 to 1 of the former
~2. The α-olefins used include propylene, ethylene, butene-1, and pentene-1.
1,2-Methylbutene-1 and the like can also be used, and are suitable when copolymerization of propylene and these other olefins is planned later. The ratio of the solid product () to α-olefin used is 0.01 to 100, preferably 0.05 to 5.0, based on the amount of the latter to be polymerized by the treatment, per 1 of the former. This treatment can also be carried out in the presence of an inert solvent, and it is preferable to use such a solvent. Processing conditions are 0 to 60°C, preferably 10 to 30°C under reduced pressure or increased pressure.
for 5 minutes to 200 minutes, preferably 10 minutes to 100 minutes. It is preferable to keep the solid-liquid dispersion state of the treated mixture uniform by appropriate stirring or shaking. As mentioned above, this treatment involves the reaction of separating the electron donor, which is a component of the solid product (), from the solid product () by reacting it with an organoaluminum compound as a processing agent. This is a reaction in which the surface of the product is coated with polyα-olefin. The degree of separation is such that the solid product () →
It can be known by analyzing the amount of electron donor bound during the reaction of the solid product () and the amount of electron donor separated from the solid product () by the subsequent organoaluminum treatment. can.
The majority of the bound amount, i.e. 70 to 99% by weight, preferably 80 to 95% by weight, is then separated. If the amount is less than 70% by weight, the performance of the obtained solid product () as a catalyst component is insufficiently improved, and removal of more than 99% by weight results in an increase in the amount of organoaluminum compound used and the processing time. The performance of the solid product () is not significantly improved. The degree of treatment with the α-olefin is preferably from 0.01 to 100 times the weight of the solid product () used, preferably from 0.05 to 5.0 times.
The solid product () contains twice the amount of polyα-olefin. The content of polyα-olefin in an amount less than 0.01 times or more than 100 times is not preferable for the same reason as the case where the electron donor removal rate is outside the range of the effects of the present invention. The above-mentioned organoaluminum compound may be used in several portions, or it may be diluted with the inert solvent described below and continuously supplied to the solid product () processing apparatus. When using an inert solvent, the following are used. That is, as aliphatic hydrocarbons, n-hexane, n
-heptane, n-octane, i-octane, etc., and halogenated hydrocarbons such as carbon tetrachloride chloroform, dichloroethane, trichlorethylene, and tetrachlorethylene can also be used instead of or together with aliphatic hydrocarbons. Also,
As aromatic compounds, aromatic hydrocarbons such as naphthalene and their derivatives mesitylene, duurene, ethylbenzene, isopropylbenzene, 2
Examples include alkyl group derivatives such as -ethylnaphthalene and 1-phernaphthalene, and halides such as monochlorobenzene and orthodichlorobenzene. The thus obtained solid product () is then treated with an organoaluminum compound (A ₂ ) and an α-olefin.
(F) and a reaction product (G) of trialkylaluminium (A ₃ ) and electron donor (B ₃₃ ) to form a catalyst. This catalyst is used to carry out suspension polymerization of propylene in the presence of an inert solvent. The following inert solvents are used. That is, as aliphatic hydrocarbons, n-hexane, n
-Heptane, n-octane, i-octane, etc. are indicated, carbon tetrachloride, chloroform, dichloroethane,
Halogenated hydrocarbons such as trichlorethylene and tetrachlorethylene can also be used. In addition, aromatic compounds include aromatic hydrocarbons such as naphthalene, derivatives thereof such as mesitylene, duurene, ethylbenzene, isopropylbenzene, 2-ethylnaphthalene, 1-phenylnaphthalene, etc., monochlorobenzene,
Examples include halides such as orthodichlorobenzene. The conditions for suspension polymerization (temperature, pressure, time, hydrogen partial pressure, polypropylene concentration in the polymerization mixture, etc.) are the same as those of known methods. The polymerization mixture obtained by the suspension polymerization is separated into a solid phase portion mainly composed of polypropylene and a liquid phase portion mainly composed of a solvent by a known method. Known methods include, for example, centrifugal or filtration separation methods.
The aforementioned solid phase portion includes, in addition to the polypropylene, the solvent still deposited, almost the entire amount of the solid product () used in the polymerization, and the organoaluminum compound dissolved in the deposition solvent. These medium-adhesive solvents are separated by vaporization and recovered when polypropylene is dried. In addition to the inert solvent which occupies most of the liquid phase, the liquid phase consists of almost the entire amount of the organoaluminum compound used in the polymerization, soluble polypropylene, dissolved propylene, and hydrogen. The liquid phase portion used in the process of the present invention to be described later may have the above-mentioned composition as is, or dissolved propylene and hydrogen may be separated and used. In the present invention, instead of the purified solvent, a recovered solvent contained in the above-mentioned liquid phase portion is used instead of a new organic aluminum compound. Therefore,
These deficiencies can be replenished with purified solvents and new organoaluminum compounds, and no special difficulties arise with their replenishment. However, when a sufficient amount of recovered solvent can be secured, the purified solvent and organoaluminum compound for replenishment may not be used, and the entire amount can be relied on the aforementioned liquid phase portion (note: including the recovered solvent and recovered organoaluminum compound). Of course. On the contrary, solid products ()
(Note: For both batch polymerization and continuous polymerization), use a new amount each time. This is because the above-mentioned liquid phase portion does not contain the circular product () and cannot be recovered. The characteristic requirements for the propylene polymerization method using the recovered solvent of the present invention are 0.01 to 1 g of the new solid product () used during the polymerization.
In the range of 10 mmol, preferably 0.01 to 1.0 mmol of electron donor and trialkylaluminium
TAA) reactant (G) (hereinafter referred to as ED/TAA) is added. The number of moles of ED/TAA is based on the number of moles of ED. This is because the molar ratio of ED:TAA in ED/TAA is not fixed as described below. The reaction conditions for ED and TAA are the same as those for the reaction product () of the electron donor (D) and the organoaluminum compound described above. That is,
1 mole of TAA is reacted with 0.1 to 8 moles of ED. Therefore, ED/TAA acts as an organoaluminum compound in the above-mentioned reaction product ().
Although the same substance is used when TAA is used, in the present invention, the reaction product () and ED/TAA used for repolymerization may be the same substance. In that case, the reason why ED/TAA is added separately in the repolymerization of the present invention is that the reaction product () itself is an indirect constituent raw material of the solid product (), and does not directly affect the repolymerization. That's because there isn't. As such ED, aromatic acid esters are preferred. Furthermore, in the above-mentioned Japanese Patent Application Laid-Open No. 120712/1984, prior to polymerizing α-olefin by combining the solid product () with an organoaluminum compound, α-
A preactivated catalyst is obtained by combining the reaction product (G) of an olefin, an organoaluminium compound, and an electron donor. This reaction product (G) contains TAA as an organoaluminum compound as its reaction raw material.
When using ED/TAA, it may be the same as the ED/TAA used in the present invention. However, in the invention of the same issue, the polymerization of ○I α-olefin is not limited to suspension polymerization using an inert solvent (note: there are many examples of gas phase polymerization), but ○B suspension polymerization was carried out. However, it is not planned that the solvent used in the polymerization will be recycled without purification. ○C What is more decisive is that in the first stage of polymerization (note: using a purified solvent), preactivation is performed and the combined ED/TAA at that time uses the recovered solvent used in the polymerization. In a repolymerization method similar to
Unlike TAA, it has almost no effect on maintaining the polymerization activity of the catalyst. For the above reasons,
The use of the above-mentioned reaction product (G) used in No. 56-120712 is completely different from the use of ED/TAA in the present invention, and the present invention cannot be predicted from the invention of the same issue. . The ED/TAA used in the present invention may be added to the polymerization system as it is, or may be diluted with an inert solvent of 10 to 100 times the amount and added. The same applies to the new solid product (). The repolymerization of the present invention is
In other respects, the polymerization can be carried out in exactly the same way as the initial polymerization using purified solvents, whether batch or continuous. In the case of continuous polymerization, the possible quantitative proportion of the recovered solvent is about 50 to 55% of the initially fed solvent, so a cyclic polymerization method is often used in which the shortage is replenished with purified solvent. On the other hand,
In batch polymerization, other polymerization conditions often differ from batch to batch, so the recovered solvent can be stored separately. Therefore, in the repolymerization of the present invention, the recovered solvent can be used for the entire amount of solvent used. The greatest effect of the present invention is that the polymerization activity of the catalyst does not decrease and the by-product rate of soluble polymer (hereinafter referred to as APP) does not increase even if recovered solvents and organic aluminum compounds are used in all amounts. In contrast, in the repolymerization that does not use ED/TAA according to the present invention, by using recovered products (solvent and organoaluminum compound), the polymerization activity of the catalyst is higher than that of the first polymerization (initial polymerization) using purified solvent. At the same time, the by-product rate of APP also increases dramatically. Another advantage of the present invention is that by allowing the use of recovered solvent (and recovered organoaluminum), the cost of solvent recovery and the cost of using organoaluminum compounds can be reduced. In the propylene suspension polymerization method using a so-called highly active catalyst, it is virtually impossible to recycle the recovered solvent in the same sense as in the conventional technology. The technical significance of making the above-mentioned cyclical use possible by specifying this is extremely great. The liquid phase part (recovered solvent) used in the repolymerization of the present invention is a combination of a solid product () and an organoaluminum compound whose catalyst system in the initial polymerization (note: using a purified solvent) is the source of the liquid phase part (recovered solvent). Even if it is not related to the combination of a solid product and an organoaluminum compound, any recovered solvent that does not substantially contain electron donors after initial polymerization can be used in the same way. . This fact is also very convenient because when using various catalyst systems in parallel, the recovered solvents used in them can be combined all at once and used for the repolymerization of the present invention. The present invention will be explained below with reference to control examples, examples, and comparative examples. Example 1 [Manufacture of solid product ()] In this example, Control Examples 1 to 7 and Examples 2 to 7 described below were
To obtain the solid product () used in
First, a solid product () was produced on a scale 100 times that of Example 1 of JP-A No. 56-120712, and the obtained solid product () was treated with DEAC and propylene to produce a solid product (). was manufactured. That is, 6 n-hexane, 5.0 mol of DEAC,
Mix 12.0 mol of diisoamyl ether at 25°C for 1 minute and react at the same temperature for 5 minutes to obtain the reaction product liquid () (molar ratio of diisoamyl ether/DEAC).
2.4) was obtained. 40 moles of titanium tetrachloride was placed in a reactor purged with nitrogen, heated to 35°C, and the entire amount of the reaction product solution () was added dropwise over 30 minutes, kept at the same temperature for 30 minutes, and then raised to 75°C. The mixture was heated and reacted for an additional hour, cooled to room temperature, and the supernatant liquid was removed. Next, 40 g of n-hexane was added and the supernatant liquid was removed by decantation, which was repeated 4 times to obtain 1900 g of a solid product. While the entire amount of this () was suspended in 30 °C of n-hexane, 1,600 g of diisoamyl ether and 3,500 g of titanium tetrachloride were added at 20°C over 1 minute at room temperature, and the mixture was reacted at 65°C for 1 hour. After the reaction is complete, cool to 20°C, remove the supernatant by decantation, add 40% n-hexane, stir for 10 minutes, let stand, and remove the supernatant 5 times. After repeating, it was dried under reduced pressure to obtain 1700 g of solid product (). Almost the entire amount of the solid product () obtained as above, 2000 g of DEAC and 30 g of n-hexane were placed in a 50 mm stainless steel reactor equipped with a stirrer, and while stirring at 20°C for 60 minutes, 200 g of propylene was added to 30 g of n-hexane. Delivered in minutes. The mixture was allowed to stand still and the supernatant was removed, and diisoamyl ether (DiAE) in the supernatant was determined by gas chromatography. The precipitate was prepared by adding 20% n-hexane, stirring for 10 minutes, standing still, and removing the supernatant liquid 5 times, and then drying under reduced pressure to obtain 1500 g of solid product ().
I got it. As a result of the above quantitative analysis, the amount of DiAE eluted into the n-hexane phase was 932 per 10 kg of solid product ().
Separately, a small amount of the solid product (2) was decomposed with water to liberate it, and then quantified. As a result, the amount of DiAE was 951 g per 10 kg of the solid product (2), and the amount of polypropylene was 1100 g. Therefore, the above
The elution rate of DiAE by DEAC treatment is (932/951)
×100=98.0%, polypropylene adhesion is 11.0%
It became. Control Examples 1 and 2 In Control Example 1, Control Examples 3 to 7 and Example 2 described below
In order to obtain the recovered solvent (hereinafter referred to as recovered solvent) used in Steps 7 to 7, initial polymerization (Note: Polymerization using only new raw materials, catalysts, and solvents (hereinafter referred to as solvent)) was carried out on a scale 20 times that of Control Example 2. Summer. That is, the capacity is 30 (control example 1) or 1.5 (control example 2)
Predetermined amounts of normal hexane (n-C ₆ ), titanium trichloride composition (solid product obtained in Example 1 ()), and DEAC were placed in a stainless steel autoclave equipped with a stirrer, and heated to 70°C. After raising the temperature ^to
As the propylene polymerized, new propylene was replenished and the internal pressure was maintained at 10 Kg/cm ² G for 2 hours. Then, the autoclave was cooled to room temperature, unreacted propylene was discharged, and the interior was replaced with nitrogen. In Control Example 1, supernatant liquid 8 was obtained, and in Control Examples 1 and 2, polypropylene was obtained according to a conventional method.
The polypropylene yield (ISOCY) per gram of titanium trichloride composition was calculated. Separately, take a certain amount of each supernatant liquid, measure the concentration of soluble polymer, that is, atactic polypropylene (APP) according to a conventional method, calculate the amount of APP produced, and calculate the amount of APP produced according to the following formula. The rate was calculated. APP production rate % = APP production amount / polypropylene yield + AP
P production amount x 100% The main polymerization conditions and results are shown in Table 1 below.
Comparative Examples 1 and 2 differ only in the scale of polymerization, both are initial polymerizations, and there is almost no difference in the polymerization results. Control Examples 3 to 6 Propylene was repolymerized in the same manner as Control Example 2, except that the supernatant liquid of Control Example 1 was used for the solvent used and some or all of DEAC.
ISOCY and APP production rates were calculated. The main polymerization conditions and results are shown in Table 1 below. As is clear from the same table, for the total amount of solvent used, Control Examples 3 to 3 used the recovered product from Control Example 1.
Compared with Control Example 2 in which initial polymerization was carried out on the same scale, Sample No. 4 had an ISOCY of 3001 to 3035, which was about 81 to 82% of the same example. On the other hand, regarding the APP production rate, in Control Example 4, in which fresh DEAC was added during repolymerization, there was almost no difference from Control Example 2, and DEAC
This shows that replenishment is effective. However, in Control Example 3, which does not undergo any of these additional treatments, the APP production rate is 1.04%, and in Control Example 2 (0.73%).
%) has increased by approximately 40%. Furthermore, control example 5
The results are as can be inferred from the comparison between Control Example 2 and Comparative Examples 3-4. Regarding ISOCY, an average value for Control Examples 2 and 3 was obtained, and for APP production rate, a value comparable to that of Control Example 2 was obtained. From the above results (Control Examples 1 to 6), a decrease in ISOCY (vs. initial polymerization) for propylene repolymerization using recovered solvent (and dissolved DEAC)
cannot be prevented by adding new DEACs, but the rate of APP generation can be prevented.

[Table] All polymerization times were 2 hours.
Comparative Examples 1 and 2 In Comparative Example 1, initial polymerization was carried out on a scale 20 times that of Comparative Example 2 in order to obtain recovered solvents to be used in Comparative Examples 3 to 6 and Examples 2 and 3, which will be described later. That is, in a stainless steel autoclave with a capacity of 60 (Comparative Example 1) or 3.0 (Comparative Example 2) equipped with a stirrer, a predetermined amount of n-hexane (n-C ₆ ) solid product () and MPT/DEAC as the catalyst component (C) were added.
After charging and heating DEAC to raise the temperature to 70℃, propylene was press-injected to give a pressure of 10Kg/cm ² G, and as the propylene polymerized, new propylene was replenished to maintain the internal pressure at 10Kg/cm ² G. The test was carried out for 2 hours. Then, the autoclave was cooled to room temperature, unreacted propylene was released, and the inside was replaced with nitrogen.
In addition to obtaining supernatant 15, polypropylene was obtained in accordance with the conventional method for both Comparative Examples 1 and 2, and the polypropylene yield (ISOCY) per 1 g of the titanium trichloride composition (solid product ()) was calculated. Separately, a certain amount of each supernatant was taken, and the concentration of soluble polymer, that is, atactic polypropylene (APP) was measured to calculate the amount of APP produced.
The APP production rate was calculated in the same manner as in 2. The main polymerization conditions and results are shown in Table 2 below. Comparative examples 1 and 2
The only difference is the scale of polymerization, both are initial polymerization, and there is almost no difference in the polymerization results. Examples 2 and 3 Using the supernatant obtained in Comparative Example 1 (recycled n-C ₆ ) in place of purified n-C ₆ , newly added DEAC
DEAC contained in the above-mentioned n-C ₆ was used instead of, and in addition to the predetermined amount of MPT/DEAC as the catalyst component (C), 0.10 mmol of MPT/TEA (same molar reactant) (Example 2) or The same procedure as Comparative Example 2 was carried out except that 0.05 mmol (Example 3) was used. The results are shown in Table 2 (Note: MPT is methyl p-toluate). Comparative Examples 3 to 6 The same procedure as in Example 2 was carried out except that the additional catalyst component (C), MPT/TEA, was not used (Comparative Example 3). DEAC 3 mmol newly added in Comparative Example 3
It was carried out in the same manner as Comparative Example 3 except for using (Comparative Example 4). In comparative example 3, newly added
The same procedure was carried out except that 0.60 mmol (Comparative Example 5) and 1.20 mmol (Comparative Example 6) of TEA were used. The results are shown in Table 2. Comparative Example 7 The same procedure as Comparative Example 2 was carried out except that 0.05 mmol of MPT/TEA was used in Comparative Example 2. The results are shown in Table 2. Recycle n-C ₆ , Recycle
When purified n-C ₅ or newly added DEAC is used instead of DEAC, results superior to those of Comparative Example 2 can be obtained in both ISOCY and APP production rate. That is,
It can be seen that the addition of MPT/TEA is effective in cases other than n-C ₆ and DEAC recycling. As is clear from Table 2, compared to Comparative Example 2 using purified n-C ₆ and new DEAC, in Examples 2 and 3 using recycled n-C ₆ and recycled DEAC, the ISOCY and APP production rates were higher. Both show almost comparable results. On the contrary
In Comparative Examples 3 to 6 in which MPT/TEA was not used, the addition of DEAC could considerably prevent an increase in the APP production rate, but could not prevent a decrease in ISOCY.
Adding TEA cannot prevent either an increase in APP production rate or a decrease in ISOCY.

[Table] All polymerization times were 2 hours.
Examples 4 to 7 Repolymerization of the present invention was carried out in the same manner as in Example 2, except that the following reaction products were used in each example in place of MPT/TEA used in Example 2. Table 3 shows the main polymerization conditions and results. Example 4 n-hexane 20ml, triethylaluminum 85
35 mg and 110 mg of hexamethyl phosphate triamide
The reaction product (hereinafter referred to as
HMPA/TEA). Example 5 84 mg of triisobutylaluminum and N, N,
N′,N′tetramethylhexaethylenediamine 90
The reaction product (hereinafter referred to as HEDA/TEA) is obtained by reacting 100 mg with 20 ml of n-hexane at 15°C for 30 minutes. Example 6 A reaction product (hereinafter referred to as DPE/TEA) obtained by reacting 23 mg of triethyl aluminum and 34 mg of diphenyl ether in 20 g of n-hexane at 15°C for 30 minutes. Example 7 11 mg of triethyl aluminum and ethyl benzoate
The reaction product (hereinafter referred to as EBA/TEA) is obtained by reacting 15mg with 15mg at 28℃ for 30 minutes.

[Table] All polymerization times were 2 hours.
As is clear from Table 3, Examples 4 to 7 in which ED/TAA in the catalyst component (C) according to the present invention was used other than MPT/TEA were also used in Example 2,
It is clear that similar results to those of Comparative Example 2 can be obtained in the same manner as in Case 3. Examples 8 and 9 Example 9 was carried out in the same manner as in Example 2, except that 1500 ml of each sample obtained in Control Example 1 was used as recycled n-C ₆ , and in the same manner as in Example 3. As is clear from Table 4, the polymerization results were ISOCY4737 and APP production rate of 0.22% for Example 8, and 4715 and 0.20% for Example 9, and these results were not inferior to those of Examples 2 and 3, respectively. . On the other hand, in Control Example 1, MPT/DEAC as the catalyst component (C)
was not used, its ISOCY and APP production rates were much inferior to Comparative Example 1. From the above, it can be seen that the effect of the present invention remains unchanged even if a reaction product such as MPT/DEAC is not added to the recycled n-C ₆ used in the present invention during its initial polymerization.

[Table] Notes *Using the supernatant of Comparative Example 1, **Using the supernatant of Comparative Example 1 ***Using the solid product () obtained in Example 1
All polymerization times were 2 hours.
Comparative Example 8 Recycled n-C ₆ obtained in Comparative Example 7
Polymerization of propylene was carried out in the same manner as in Comparative Example 7 except that 800 ml was used and a 1.5 ml autoclave was used. As is clear from Table 5, the polymerization results are as follows:
ISOCY3707, APP generation rate was 0.49%. These results are significantly inferior to Comparative Example 7 or Example 2, and are almost equivalent to Comparative Example 3 in which MPT/TAA is not used during repolymerization. This means that according to the present invention
It has been revealed that ED/TAA is ineffective unless added during repolymerization. Comparative Example 9 Propylene polymerization was carried out in the same manner as in Comparative Example 8, except that 800 ml of the recycled n-C ₆ obtained in Example 2 was used and a 1.5 autoclave was used. The results are shown in Table 5. As is clear from Table 5, the polymerization results were almost the same as Comparative Example 8 in both ISOCY and APP production rate, which was significantly inferior to Comparative Example 7 or Example 2, and compared to Comparative Example 3 in which MPT/TEA was not used during repolymerization. Almost the same. This makes it clear that the ED/TAA involved in the present invention is ineffective unless added during repolymerization, and if the solvent is repeatedly used for repolymerization, the decrease in ISOCY is not so large, but the APP It can be seen that the production rate increased significantly. Example 10 MPT/TEA (equal mole reactants) using 800 ml of the material obtained in Example 3 as recycled n-C ₆
Polymerization of propylene was carried out in the same manner as in Comparative Examples 8 and 9, except that 0.05 mmol was used. As is clear from Table 5, the polymerization results are ISOCY
Both the APP production rate was approximately the same as Comparative Example 7 and Examples 2 and 3, and good results were obtained. This is true even if the ED/TAA reactant (equal moles) related to the present invention is added when the solvent is repeated and used for repolymerization (APP is increased in Comparative Example 9 than in Comparative Example 8). ,
It can be seen that it is effective in activity, reduction, prevention, and prevention of APP increase.

【table】

【table】 [Brief explanation of drawings]

FIG. 1 is a flow sheet illustrating the method of the present invention.

Claims (1)

[Scope of Claims] 1. A solid obtained by further reacting an ether and titanium tetrachloride with a solid product () obtained by reacting a reaction product () of an organoaluminum compound and an ether with titanium tetrachloride. The solid product () obtained by treating the product () with an organoaluminum compound and an α-olefin is inertized using a catalyst in combination with an organoaluminum compound and a reaction product of the organoaluminum compound and an electron donor. Propylene is subjected to suspension polymerization in the presence of a solvent, and the resulting polymerization mixture is separated into a solid phase portion containing polypropylene as a main component and a liquid phase portion containing an inert solvent as a main component. A method in which propylene is again suspended polymerized by adding a solid product (2), and in the repolymerization, 0.01 to 10 mmol, 0.01 to 10 mmol per 1 g of the new solid product (2).
A method for suspension polymerization of propylene using a recovered solvent, characterized by adding 1.0 mmol of a reaction product of an aromatic acid ester and a trialkylaluminum. 2 Use 0.1 to 10 times the weight of the organoaluminium compound to the solid product (), and heat at 0 to 60°C under normal pressure, reduced pressure, or increased pressure in the presence of α-olefin.
The method according to claim 1, wherein the treatment is performed for 5 minutes to 200 minutes. 3 Add α-olefin to the solid product ()
The method according to claim 2, wherein the polymerization is carried out 0.01 to 100 times. 4. As a reaction product of aromatic acid ester and trialkylaluminium, 0.1 to 8 mol of methyl paratoluate or ethyl benzoate is mixed with 1 mol of trialkylaluminium at -20 to 200°C for 30 seconds to 5.
The method according to claim 1, which uses a time-reacted product.