JPS58138707A - Preparation of polyolefin - Google Patents

Abstract

PURPOSE:To prepare a highly stereoregular polymer in high yield, and to reduce the cost of solvent purification, by polymerizing an olefin in liquid phase using a catalyst containing a highly active Ti catalyst component, and recycling and reusing the liquid phase to the polymerization system. CONSTITUTION:An olefin is polymerized in liquid phase by using a catalyst composed of (A) a highly active Ti catalyst component containing Mg, Ti and halogen (preferably Cl) as essential components and usually obtained by contacting an Mg compound with a Ti compound (preferably TiCl4), and if necessary, with an electron donor, (B) an organo-Al compound (preferably triethyl aluminum, etc.) and (C) an organo-Si compound (preferably methyltrimethoxysilane, etc.) or a hindered amine (e.g. 2,6-substituted piperidine, etc.). The liquid phase obtained by separating the polymer from the polymerization reaction mixture is recycled and reused to the polymerization reaction system.

Description

[Detailed description of the invention] The invention relates to a method for producing polyolefins.

In particular, the present invention relates to a method that allows industrially advantageous production of the most stereoregular polymer.

A number of methods are known for carrying out the liquid phase polymerization of olefins in an inert solvent or in liquid olefins in the presence of a catalyst formed from a transition metal compound catalyst component, an organoaluminium compound catalyst component and an electron donor catalyst component. ing. In particular, this method has attracted attention as a method capable of producing highly stereoregular polymers of α-olefins having 3 or more carbon atoms with high catalytic efficiency. Generally, after the polymer is separated from the polymerization reaction mixture obtained by liquid phase polymerization by filtration, centrifugation, etc., the liquid phase is subjected to a distillation operation to separate the solvent or olefin and recover it as a purified product. and reused. In this way, solvent-soluble by-products such as low molecular weight polymers and low stereoregular monomers produced during polymerization and a portion of catalyst residues are effectively removed from the system. If the liquid phase excluding the polymer is that! When returning the product to the polymerization system, there is a concern that this undesirable by-product will be mixed into the product, and that the modified catalyst residue will return to the polymerization system, causing disadvantages such as having a negative impact on the polymerization reaction. In fact, such methods have been proposed in systems that do not use electron donor catalyst components (for example, Japanese Patent Publication No. 36-94 and Japanese Patent Publication No. 40-529), especially when using highly stereoregular polymers. This could not be said to be a technology that could be practically adopted in manufacturing.

The present inventors have focused on the liquid phase polymerization of olefins, particularly those having 3 carbon atoms.
In the above highly stereoregular polymerization of α-olefins, the polymerization activity per unit catalyst is high, the stereoregularity is excellent,
Furthermore, a new method for producing polyolefins has been discovered that can achieve further improvement by circulating the liquid phase into the polymerization system as described above. Although it is possible to produce extremely high polymers,
By circulating the liquid phase as described above, it is possible to arbitrarily produce a polymer having appropriate stereoregularity. Moreover, not only is there no adverse effect on the polymerization reaction due to the circulation of the liquid phase, but the effect that the amount of the electron donor catalyst component to be used can be reduced can be obtained. Of course, since the conventional liquid phase distillation operation can be omitted or reduced, it is possible to reduce the manufacturing cost of polyolefin.

In the present invention, H, (A) a highly active titanium catalyst component containing magnesium, titanium and halogen as essential components, (B)
Liquid polymerization of olefin is carried out using a catalyst formed from an organoaluminum compound catalyst component and (C) an organosilicon compound catalyst component or a sterically hindered amine catalyst component, and a liquid phase obtained by separating and removing the polymer from the resulting reaction mixture. Provided is a method for producing a polyolefin, characterized in that part or all of the polyolefin is recycled in the polymerization reaction.

The highly active titanium catalyst component (A) used in the present invention is titanium,
It is a solid compound containing magnesium and halogen as essential components, and the specific surface area of magnesium halide containing magnesium halide is lower than that of commercially available magnesium halides.
As mentioned above, it is preferably 10 to 1000 m2/g, preferably 40 to 800 m2/g, and the composition is not substantially changed by hexane washing at room temperature. The mutual proportions of each component include halogen/titanium (atomic ratio) of about 5 to about 200, particularly about 5 to about 100, and magnesium/titanium (atomic ratio) of about 2 to about 100, especially about 4 to about 50. preferable. The titanium catalyst component (A) may also contain electron donors, organic groups (e.g. plucoxyl groups, acyloxy A4, etc.), other metals, or elements (e.g. aluminum, silicon, tin, phosphorus, etc.). A suitable titanium catalyst component (A),
The electron donor/titanium (molar ratio) is approximately 0.0.
5 to about 6, particularly about 0.1 to about 5.

Such a titanium catalyst component is usually obtained by contacting each other with a magnesium compound and a titanium compound, optionally with an electron donor, and in some cases with other reactants, such as compounds such as silicon, aluminum, etc. can be used.

As a method for producing such titanium catalyst component (A),
For example, Japanese Patent Publication No. 50-32270, Kaikai No. 50-10
No. 8385, No. 50-126590, No. 51-202
No. 97, No. 51-28189, No. 51-64586, No. 51-92885, No. 51-136625. No. 52-87489, No. 52-100596, No. 52
-147688, 52-104593, 53-
No. 2580, No. 53-40093, No. 53-4309
No. 4, No. 55-135102, No. 55-135103
No. 56-811, No. 56-11908, No. 56
It can be manufactured according to the method disclosed in No. 18608 and the like.

Several examples of methods for producing these titanium catalyst components (A) will be briefly described below.

(1) A magnesium compound or a complex compound of a magnesium compound and an electron donor, an electron donor.

Pretreated with an electron donor and/or a reaction aid such as an organoaluminum compound or a halogen-containing silicon compound, with or without grinding, in the presence or absence of a grinding aid, etc. The solid obtained without treatment is reacted with a titanium compound forming a liquid phase under the reaction layer. Preferably, the above-mentioned electron donor is used at least once. (2) A solid titanium composite is produced by reacting a liquid magnesium compound having no reducing ability with a liquid titanium compound in the presence of an electron donor. (3) The product obtained in (2) is reacted with a titanium compound.

(4) React the material obtained in (1) or (2) with an electron donor and a titanium compound.

(5) Magnesium compound or magnesium compound 1
A complex compound of electron donor and electron donor is ground in the presence or absence of an electron donor, a grinding aid, and a titanium compound, and the electron donor and/or an organoaluminum compound or a halogen-containing silicon compound are ground. The solids obtained with or without pretreatment are treated with halodane or halogen compounds or aromatic hydrocarbons. Preferably, the above electron donor is used at least once. (6) The compound obtained in (1) to (4) above is treated with a halogen or a halogen compound or an aromatic hydrocarbon. These preparation methods Among these, it is preferable to use a liquid titanium halide in catalyst preparation, or to use a halogenated hydrocarbon after or during the use of a titanium compound. Magnesium compounds used for preparation include magnesium oxide, magnesium hydroxide, hydrotalcite, magnesium carboxylate, alkoxymagnesium, allyloxymagnesium, alkoxymagnesium halide, allyloxymagnesium halide, magnesium halide, organomagnesium compound 1, Examples include organic magnesium compounds treated with electron donors, halosilanes, alkoxysilanes, silanols, Al compounds, and the like.

The organoaluminum compound that may be used in the preparation of the titanium catalyst component can be appropriately selected from organoaluminum compounds that can be used in olefin polymerization described below. Furthermore, halogen-containing silicon compounds that may be used for preparing titanium catalyst components include:
Examples include silicon tetrahalides, silicon alkoxy halides, silicon alkyl halides, and halopolysiloxanes.

Examples of the titanium compound used for preparing the titanium catalyst component include titanium tetrahalide, alkoxytitanium halide, allyloxytitanium halide, alkoxytitanium, allyloxytitanium, and titanium tetrahalide, with titanium tetrachloride being particularly preferred.

In addition, oxygen-containing electron donors such as alcohols, phenols, ketones, aldehydes, carboxylic acids, organic or inorganic acid esters, ethers, acid amides, and acid anhydrides can be used as electron donors for producing titanium catalyst components. Examples include nitrogen-containing electron donors such as ammonia, amines, nitriles, and isocyanates.

More specifically, methanol, ethanol, propanol, pentanol, hexanol, octanol, 2-
Alcohols with 1 to 18 carbon atoms such as ethylhexanol, dodecanol, octadecyl alcohol, penzyl alcohol, phenylethyl alcohol, cumyl alcohol, isopropylpenzyl alcohol; phenol, cresol, xylenol, ethylphenol, propylphenol, cumylphenol , nonylphenol, naphthol, etc., which may have an alkyl group with 6 carbon atoms
Phenols having 3 to 25 carbon atoms; Ketones having 3 to 15 carbon atoms such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone; 2 to 15 carbon atoms such as acetaldehyde, propionaldehyde, octylaldehyde, penzaldehyde, tolualdehyde, naphthaldehyde, etc. 13 aldehydes; ■ Methyl acid, ethyl acetate.

Vinyl acetate, propyne acetate, octyl acetate, cyclohexyl acetate, ethyl glopionate, methyl acetate, ethyl valerate, ethyl stearate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonate, dibutyl maleate, butyl malonic acid Diethyl, diethyl diptylmalonate, ethyl cyclohexanecarboxylate, diethyl 1,2-cyfukuhexanedicarboxylate, 1
．． Di-2-ethylhexyl 2-cyclohexanedicarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, ethyl toluate, ethyl toluate, Amyl toluate, ethyl ethylbenzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, r-butyrolactone, δ-valerolactone, coumarin, phthalide , organic acid esters having 2 to 30 carbon atoms, including the esters listed below, which are preferably contained in titanium catalyst components such as ethylene carbonate; ethyl silicate, butyl silicate, vinyltriethoxysilane, phenyltriethoxysilane, diphenyldi Inorganic acid esters such as ethoxysilane; C2-15 acid halides such as acetyl chloride, benzoyl chloride, toluic chloride, anisyl chloride, and phthalic cyclolide; methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, tetrahydrofuran,
Ethers having 2 to 20 carbon atoms such as anisole and diphenyl ether; acid amides such as acetic acid amide, benzoic acid amide and toluic acid amide; acid anhydrides such as benzoic anhydride and phthalic anhydride; methylamine, ethylamine,
Examples include amines such as diethylamine, tributylamine, pipericin, tripendylamine, aniline, pyridine, picoline, and tetramethylethylenediamine, and nitriles such as acetonitrile, benzonitrile, and tolnitrile. To these electron donors, 2
More than one species can be used.

Examples of the halogen atoms constituting the titanium catalyst component include fluorine, chlorine, bromine, iodine, and mixtures thereof, with chlorine being particularly preferred. and, more preferably, the general formula % formula % (where KR1 is a substituted or unsubstituted hydrocarbon group, R2, R
3, R5 is hydrogen or substituted or unsubstituted dihydrogen group, R3
, k4 are hydrogen or a substituted or unsubstituted hydrocarbon group, and preferably at least one of them is a substituted or unsubstituted hydrocarbon group. Further, R3 and R4 may be connected to each other. The substituted hydrocarbon groups for R1 to R6 above include those containing different atoms such as N, 0, and S, such as C-
0-C.

COOR, COOH, OH, SO, H, -C-N-C-
, NH2 and the like. ), specifically, dibutyl malonate, isopropyl diethyl malonate, n-butyl diethyl malonate, phenyl diethyl malonate, 2-allyl diethyl malonate, diisobutyl malonate. Diethyl, di-n-butyl diethyl malonate, di-n-butyl succinate, diethyl methylsuccinate, dibutyl ethylsuccinate,
Dimethyl seleate, Sibutyl maleate, Monootathyl maleate, Dioctyl maleate, Diptyl butyl maleate, Diethyl butyl maleate, Dii fumarate
so-octyl, diethyl itaconate, di-n-butyl itaconate, dimethyl citraconate, diethyl l,2-cyclohexanedicarboxylate, dimethyl phthalate, monoisobutyl phthalate, diethyl phthalate, ethyl phthalate
Butyl, di-n-propyl phthalate, n-butyl phthalate,
isobutyl phthalate, di-n-heptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, dineopentyl phthalate, benzylbutyl phthalate, diphenyl phthalate, diisobutyl naphthalene dicarboxylate,
Di-2-ethylhexyl sepacate, and the like. Particularly preferred among these esters are malonic acid, substituted malonic acid, substituted succinic acid, maleic acid, substituted maleic acid. 1.2-Cyclohexanedicarboxylic acid is an ester of phthalic acid or the like with an alcohol having 2 or more carbon atoms. In the present invention, the above titanium catalyst component (A), an organoaluminium compound catalyst component (B) and an organosilicon Liquid phase polymerization of olefins is carried out using a combination catalyst of a compound catalyst component or a sterically hindered amine catalyst component (C).

The above component (H) includes (i) at least 1 in the molecule;
an organoaluminum compound having Al-carbon bonds,
For example, the general formula R1mAl(OR2)nHpXq (where R1 and R2 are carbon atoms, usually 1 to 15
, preferably 1 to 4 hydrocarbon groups, which may be the same and different from each other by %, OX is a halogen, m is 0<m≦
3, n is 0≦n<3, p is 0≦p<3, q is 0≦q<3
and m+n+p+q=3), (ii) a first compound represented by the general formula M1AlR1 (where M1 is Li, Na, R, and R1 is the same as above) Examples include complex alkylated products of group metals and aluminum.

Among the aluminum compounds belonging to (1), more specifically, triethylaluminum, tributylaluminum, etc. are referred to as trialkylaluminum.

In addition to trialkenyl aluminum such as triisobrenyl aluminum, dialkyl aluminum alkoxide such as diethylaluminum ethoxide, diptylaluminum butoxide, alkyl aluminum sesquialkoxide such as ethyl aluminum sesquiethoxide, ethyl aluminum sesquiethoxide, R125
partially alkoxylated alkyl aluminum having an average composition expressed as Al(OR■) 0.5,
Dialkyl aluminum halides such as diethylaluminium chloride, sibutyl aluminum chloride, diethylaluminium bromide, alkyl aluminum sesquihalides such as ethyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquipromide, ethyl aluminum cyclolide, propyl aluminum Partially halogenated alkylaluminum such as alkylaluminum dihalides such as dichloride, butylaluminum nopromide etc., dialkylaluminum hydride such as diethylaluminum hydride, dibutylaluminum hydride, ethylaluminum dihydride, propylaluminum dihydride etc. Partially hydrogenated alkylaluminiums such as alkyl alkenium dihydrides, ethyl aluminum ethoxy chloride, butyl aluminum butoxy chloride. Partially alkoxylated and herogenated π such as ethylaluminum ethoxy chloride
It is an alkyl aluminum.

Compounds belonging to (ii) above include LiAl(C2
Examples include H3)4LiAl(C7H15)4.

Compounds similar to (i) may also be organoaluminum compounds in which two or more aluminum atoms are bonded through a phone atom in an oxygen atom. Examples of such compounds include (C2H5)2AlOAl(C2H3)2, (C4H2
)2AlOAl(C4H3)2, etc. can be displayed.

Among these, it is particularly preferable to use trialkylaluminum or the above-mentioned alkyl aluminum in which two or more aluminums are combined.

Component (C) in the present invention is selected from organosilicon compound catalyst components and sterically hindered amine catalyst components. 7 Typical organosilicon compound catalyst components.

Compounds bearing at least one Si-O-C bond, such as alkoxysilanes, aryloxysilanes (aryl
oxysilanc), etc. As such an example, the formula RmSi(OR1)4-n, where 0≦n≦3, R
is a hydrocarbon group, such as an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a haloalkyl group, an aminoalkyl group, or a halogen; R1 is a hydrocarbon group, such as an alkyl group, a cycloalkyl group, an aryl group; Alkenyl group, alkoxyalkyl group, etc., provided that n R,
The (4-n) OR1 groups may be the same or different.

) can be mentioned.

Other examples include siloxanes having an OR1 group and silyl esters of carboxylic acids.

In addition, as another example, a compound having no Si-O-C bond and a compound having an O-C combination may be reacted in advance, or a compound having an Si-O-C bond may be reacted at the reaction site. It may also be used by converting it into . An example of this is the combination of SiCl4 and alcohol. Organosilicon compounds may also contain other metals (eg, aluminum, tin, etc.).

LD specifically includes trimethylmethoxysilane, trimethylethoxysilane, dimethylnomethoxysilane, dimethylnoethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane, methyltrimethoxy Silane, phenyltrimethoxysilane.

r-Chlorpropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, r-aminopropyltriethoxysilane, chlortriethoxysilane, ethyltriiso Propoxysilane.

Examples include vinyltriptoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriaryloxysilane, vinyltris(β-methoxyethoxysilane), vinyltriacetoxysilane, dimethyltetraethoxydisiloxane, etc. Among these, methyltrimethoxysilane, phenyltrimethoxysilane,
The above formula RnSi such as methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltriptoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyl silicate, etc.
This is a compound represented by (OR')4-n.

Other examples of organosilicon compound catalyst components include, for example:
Examples include compounds in which two or more silicon atoms are bonded to each other via oxygen, such as hexaethoxydisiloxane and symmetrical diphenyltetraethoxydisiloxane. As an example, [where R
2 is a hydrocarbon, preferably a substituted or unsubstituted alkylene group, preferably the alkylene group has 2 or 3 carbon atoms.
is an alkylene group.

When a substituted alkylene group, the substituent is, for example, a hydrocarbon group, such as an alkyl group, an acyloxy group, an alkoxyl group, and the like. R3, R4, R5, and R6 are hydrogen or hydrocarbon groups that may have a wrinkle substituent, and R3 and R
At least one of 4 and at least one of R3 and R6 is a hydrocarbon group, and R3 and R4 or R5 and R6 are linked to each other to form a ring, such as a carbocycle or an atom ring. It's okay. Preferably R3, R4, R5
, R6 are all hydrocarbon groups. Also, when one of R3 and R4 or R3 and R6 is hydrogen, the other is 2
or tertiary hydrocarbon group], or a heterocyclic compound having a skeleton of the general formula [wherein R
11, R12, R13, and R14 are hydrocarbon groups that may have substituents, and R11 and R12 or R13 and R14
may be connected to each other to form a shadow ring. Also, R1
Either 1 or R12 and either R13 and R14 may be linked together to form a ring.

R14 is a substituted methylene diamine compound having a skeleton represented by hydrogen or a hydrocarbon group.

Specifically, for example, the heterocyclic compound may be a compound of the general formula [wherein R3, R4, R5, and R6 are the same as above, and R1 is hydrogen or a hydrocarbon group, a metal, or an alkyl metal.

0≦n≦
3, 0≦m≦2 volumes, and n or m R10s may be the same or different. ] More specifically, 2,6-substituted pipericines such as the following can be exemplified.

2,5-substituted pyrrolidines such as etc. can be given as an example.

Further, the substituted methylene diamine compounds include, specifically, N,N,N',N'-tetramethylmethidinediamine, N,N,N',N'-tetraethylmethylenediamine, 1,3 dipendyl Examples include imidazolidine and 1,3-dibenzyl-2-phenylimidazolidine.

The olefins used for polymerization include ethylene, propylene, 1-butyne, 4-methyl-1-pentene, 1-octene, etc., and these can be subjected to not only monopolymerization but also random copolymerization and block copolymerization. can. In copolymerization, polyunsaturated compounds such as conjugated dienes and non-conjugated dienes can be selected as copolymerization components.

In the present invention, the polymerization is carried out in a liquid phase. The reaction medium may be an inert solution such as hexane, heptane, kerosene, or the olefin itself.
Component A) is about 0.0001 to about 1.0 mmol in terms of titanium atoms, and component (B) is about 1 mol of metal atoms in component (B) per mole of titanium atoms in component (A). Component (C) is added in an amount of about 0.0 to about 2,000 mol, preferably about 5 to about 500 mol, more preferably about 5 to about 200 mol, per mol of metal atom in component (B). 001 to about 10 moles, preferably about 0
．． 0.04 to about 1 mol, particularly preferably about 0.04 to about 1 mol.

These catalyst components (A), (B), and (C) may be brought into contact with each other during polymerization, or may be brought into contact with each other before polymerization.

In contacting before this ratio, only two arbitrary components may be freely selected and brought into contact, or a portion of each component may be brought into contact with two or three components. Furthermore, each component may be brought into contact with each other before polymerization under an inert gas atmosphere or under an olefin atmosphere. In this L-chain catalyst system, (A) ( B) When (c) is brought into contact, at least component (C) is bonded to component (A) at a ratio of 0.1 atom or more in terms of Si or N atom per 1 atom of titanium in (A). It is preferable to select a combination of (A) and (C) as follows;
A) is 10 mmol in terms of titanium atoms, (B) is triethylaluminum 100 mmol, and (C) is S
Add 30 mmol in terms of i atoms or N atoms, and bring the mixture into contact at 30° C. for 60 minutes with stirring.

When applying the present invention to a continuous polymerization process, (A) the highly active titanium catalyst component, the (B) the organic After olefin polymerization is carried out batchwise or continuously under conditions milder than the main polymerization system using a catalyst system consisting of an aluminum compound component and (C) an organosilicon compound catalyst component or a sterically hindered amine catalyst component. , it is preferable to carry out main polymerization. The mild conditions mentioned here include, for example, whether the pressure is lower and/or the temperature is lower than that of the main polymerization system, and/or the system of the (B) organoaluminum compound component with respect to the (A) highly active titanium catalyst component. An example is a condition where the ratio [(B)/(A)) in the polymerization system is lower than that of the main polymerization system. In addition, the amount of polymerized olefin under the mild conditions is 0.1 g or more, preferably 0.5 g or more, particularly preferably 1 g or more, per 1 g of the (A) high oil-based titanium catalyst component to ensure stable processing. From the viewpoint of operability and productivity, the smaller the amount of polymerization is, the better. When polymerization is carried out batchwise under mild conditions, the amount of olefin per 1 g of the highly active titanium catalyst component (A) The amount of polymerization is
It is 1000 g or less, more preferably 100 g or less, particularly preferably 10 g or less. On the other hand, when it is carried out continuously, the amount is 2000 g or less, more preferably 100 g or less. The polymerization temperature of the olefin is preferably about 20 to about 200°C, more preferably about 50 to about 180°C, and the pressure is constant. It is preferable to carry out under pressurized conditions of from about 100 kg/cm 2 to about 100 kg/cm 2 , preferably from about 2 to about 50 kg/cm 2 . Polymerization can be carried out in any of the batch, semi-continuous, and continuous methods. Also, the concentration of the polyolefin in the liquid phase is about 50 to about 1000 g/4, particularly about 100 to about 500 g.
/l is preferable.In particular, when the purpose is to produce a stereoregular homopolymer of α-olefin having 3 or more carbon atoms, the production ratio of the stereoregular polymer in the polymerization system is at least 34% or more. In particular, it is preferable to apply the present invention to a system in which the polyolefin is 96% or more. In the present invention, the polyolefin is separated and removed from the thus obtained polymerization reaction mixture by ordinary separation means such as filtration and centrifugation. Part or all of the liquid phase is used again for the polymerization reaction.

It is sufficient that the main amount is removed to the polyolefin, and by-product polyolefins such as low molecular weight substances and non-quality polyolefins may remain in the polyolefin in the liquid phase.

Before separating the polyolefin or after separating and removing the polyolefin, before circulating the liquid phase to the polymerization system, some or all of the easily volatile components in the liquid phase may be removed by an operation such as concentration. . During this circulation, the effect is recognized by causing about 10% by weight or more of the liquid phase from which the polyolefin has been separated and removed to be destroyed in the polymerization system, but in order to obtain an even better effect, 30% by weight of the liquid phase Above, it is particularly preferable to circulate 50% by weight or more.

(B) component and/or (
C) Not only can the total amount of ingredients used be reduced,
It is possible to greatly reduce the cost spent on the solvent purification system.For example, if the polymerization is carried out without the circulation,
In cases where a polyolefin having a stereoregularity index higher than desired is obtained, a polyolefin having a desired moderate stereoregularity index can be produced by adjusting the amount of circulation. The yield of polyolefin based on the olefin used can be greatly increased.O Example 1 [1] Preparation of highly active titanium catalyst component (A) Anhydrous magnesium chloride 2.38 kg, decane 12 .5L of 2-etherhexyl alcohol 3.26kg at 120℃
After heating the reaction for several hours to obtain a homogeneous solution, 0.56 kg of phthalic anhydride was added to this solution, and the mixture was further heated to 130°C for 1 hour.
After stirring and mixing for an hour, phthalic anhydride is dissolved in the homogeneous solution. After cooling the homogeneous solution thus obtained to room temperature, it is poured into 100 liters of titanium tetrachloride kept at -20°C for 1 hour. Charge the entire amount dropwise. After charging, the temperature of this mixed liquid was raised to 110°C over 4 hours, and then the temperature was increased to 110°C.
When it reached 1.75 kg of diisobutyl phthalate
was added and kept under stirring at the same temperature for 2 hours.
After the completion of the 2-hour reaction, the solid part was collected by hot filtration, and this solid part was resuspended in 100 liters of TiCl4, and then heated again at 110°C for 2 hours. The solid portion is collected by filtration and thoroughly washed with decane and hexane at 110° C. until no free titanium compound is detected in the washing liquid. The active titanium catalyst component (A) synthesized by the above production method is stored as a hexane slurry, and a portion of this is dried for the purpose of examining the catalyst composition. Highly active titanium catalyst component (A) obtained in this way
The composition was 28% by weight titanium, 55.8% by weight chlorine, 18.0% by weight madanesium and 14.3% by weight diisobutyl phthalate.

[■] Catalyst O pretreatment Purified hexane 5 was added to the nitrogen-substituted 100 l reactor.
After charging 0l, 2.25mol of triethylaluminum
and highly active titanium catalyst acid branch 0.75 in terms of titanium atoms
After charging mol, propylene was fed over 4 hours at a feed rate of 600 l/hour to polymerize 2.7 g of propylene per 1 g of the highly active titanium catalyst component.

[■] Polymerization Propylene was polymerized using a polymerization process in which the main parts of the polymerization process consisted of two 100-liter polymerization vessels, a flash drum, and a decanter connected in sequence. The supply amount of each catalyst component and hexane used as a polymerization solvent was 1
Per hour, 10 mmol of triethylaluminum, 1.0 mmol of phenyltriethoxysilane, 0.2 mmol of the titanium-containing catalyst component in terms of titanium atoms contained, and 10 liters of hexane were introduced into the first polymerization reactor.

For hexane, an additional 5.6 liters were added to the second polymerization kettle. The polymerization pressure of the first polymerization pot is 13kg/cm2-G.
, so that the weight of the second double pot is 10kg/cm2-G.

This was adjusted by supplying propylene to both polymerization vessels.

Further, the molecular weight was adjusted by changing the amount of hydrogen supplied, and hydrogen was supplied to both polymerization reactors so that the concentration ratio of hydrogen and propylene in the gas sections of the first and second polymerization reactors was the same. The polymerization temperature was 75°C in both polymerization vessels, and the boiling time was 3 hours in the first polymerization vessel and 2 hours in the second polymerization vessel.

The liquid phase separated by the decanter was 13.9 l/hour, but the polymerization result (level -1) when this entire amount was sent to the hexane purification system and the liquid phase separated by the decanter were 50% is returned to the reactor, reducing the amount of fresh hexane supplied to match the circulating amount.

Polymerization results when the remaining 50% was sent to the hexane refining thread (
level 2), and 80% of the liquid layer separated by a decanter.
% is returned to the reactor, the amount of new hexane supplied is reduced to match the circulating amount, and the remaining 20% is sent to the hexane purification system (level-3), and the polymerization results at level-2 are as follows: Polymerization results when the feed amounts of triethylaluminum and phenyltriethoxysilane were reduced to -5.0 mmol/hour and 0.5 mmol/hour (level -
4) are shown in Table-1. The activity shown in Table 1 (g-p
p-mmol-Ti) was calculated from the amount of propylene consumed per unit time per titanium atom in the highly active titanium catalyst component supplied to the reaction vessel per unit time.

Example 2 After charging 1.04 liters of purified n-decane into a 2-liter glass cylindrical reactor equipped with a stirring blade, 70 ml of purified n-decane was charged while introducing propylene.
The temperature was raised to ℃. At 70°C, triethylaluminum 5
．． 0 mmol, phenyltriethoxysilane 0.5 mm
During the 6-polymerization, propylene polymerization was carried out at 70° C. for 4 hours by adding the same highly active titanium catalyst component as used in Example 1 in an amount corresponding to 0.05 mmol of titanium atoms. A mixed gas of 150 l/Hr of propylene and 0.45 l/Hr of hydrogen was supplied into the reactor (
distribution system). After the polymerization was completed, stirring was stopped and left to stand, and the 500 ml of supernatant liquid was replaced with nitrogen in a 1 liter container with a stirring blade.
- Transfer the liquid to a glass cylindrical reactor and propylene 150l/H
r, hydrogen 0.45l/Hr mixed gas supply (flow system)
The temperature was then raised to 70°C. At 70°C, a highly active titanium catalyst component similar to that used in Example (1) was added in an amount corresponding to 0.025 mmol of titanium atoms, and propylene polymerization was carried out at 70°C for 2 hours. The polymer powder obtained by both polymerization reactions was thoroughly washed with hexane and then dried, and the yield, MFR, and boiling hebutane non-extractability (
■) was measured. The results are shown in Table 3.

Examples 3 to 4 In Example 2, the phenyltriethoxysilane added during polymerization was replaced with diphenyldimethoxysilane and 2,2.
Example 2 except that 6,6-tetramethylpiperidine was used.
Propylene polymerization was carried out in the same manner as above. Display the results -
Shown in 3.

Claims (1)

[Scope of Claims] (A) a highly active titanium catalyst component that removes magnesium, titanium, and halogen as essential components; (B) a specific aluminum compound catalyst component; and (C) an organosilicon compound catalyst component or a sterically hindered amine catalyst component. A liquid phase polymerization sound material of olefin using a formed catalyst, and a part or whole of the liquid phase after separating and removing the polymer from the resulting polymerization reaction mixture is recycled to the polymerization reaction system. Production method.