JPS59176307A - Production of polypropylene - Google Patents

Abstract

PURPOSE:To produce, in high activity, PP having a uniform particle diameter, a high bulk density and high stereoregularlity, by polymerizing propylene in the presence of a specified catalyst containing a Mg compound having a specified average particle diameter and a particle distribution. CONSTITUTION:In (co)polymerizing propylene in the presence of a catalyst consisting mainly of (A) a reaction product between a Mg compound and a Ti compound and (B) an organometallic compound, use is made of, as the Mg compound in component A, a compound represented by the formula (wherein R<1> is a 1-10C alkyl, cycloalkyl, aryl, alkenyl or aralkyl, X<1> is a halogen, and n is 1.0-2.0) and having such a particle diameter distribution that its average particle diameter is 20-100mu and particles of a diameter <=10 account for 10wt% or below. This makes it possible to produce, in high activity, PP having a uniform particle diameter, a high bulk density and high stereoregularity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polypropylene, and more specifically, the present invention relates to a method for producing polypropylene, which mainly comprises an activated titanium catalyst component prepared using a magnesium compound having a specific average particle size and particle size distribution, and an organometallic compound. The present invention relates to a method for producing polypropylene with uniform particle size, high bulk density, and high stereoregularity with high activity by polymerizing propylene using a catalyst.

Various methods have been proposed to obtain polypropylene with high stereoregularity using catalysts consisting of solid catalyst components containing magnesium and titanium and organometallic compounds (Japanese Patent Application Laid-open No. 74103/1983, 56-992
Publication No. 07, Publication No. 56-115301, Publication No. 56-1
No. 20711, No. 57-166205, No. 5
7-63308, etc.).

However, in these conventional methods, the particle size of the obtained polymer is irregular, and in particular, there is a relatively large amount of fine powder with a particle size of less than 150 μm, which often causes various troubles. Therefore, if polymerization is carried out using a catalyst prepared to narrow the particle size distribution of the produced polymer particles, the above troubles will be resolved, but other problems will occur, such as a decrease in the bulk density of the produced polymer particles. There are drawbacks.

An object of the present invention is to efficiently produce a polymer (polypropylene) having a narrow particle size distribution with high bulk density and uniform particle size, and the present inventors have conducted extensive research from this viewpoint. As a result, it was discovered that the object could be achieved by using a magnesium compound having a specific average particle size and particle size distribution as the magnesium compound used in preparing the activated titanium catalyst, and the present invention was realized. It was completed.

That is, the present invention provides a method for producing polypropylene by homopolymerizing or copolymerizing propylene using (4) a reaction product of a magnesium compound and a titanium compound and (13) a catalyst containing an organometallic compound as a main component,
General formula Mg(OR') x', (in the formula, ]]
-n R1 represents an alkyl group, cycloalkyl group, aryl group, alkenyl group or aralkyl group having 1 to 10 carbon atoms, and Xl represents a norogen atom. Also, n is 10 to 2,
Indicates a real number of 0. ), and the average particle size is 2
The present invention provides a method for producing polypropylene, characterized in that a compound having a particle size distribution of 0 to 100 microns and 10% by weight or less of particles of 10 microns or less is used as the magnesium compound in the component (4).

As mentioned above, the magnesium compound used in the present invention is represented by the general formula Mg(OR')nX", -n, and specifically includes magnesium dimethoxide, magnesium jetoxide, magnesium dipropoxide, and magnesium dibutoxide. and magnesium monohalogenated monoalkoxides such as magnesium monochloromethoxide, magnesium monochloroethoxide, and magnesium monochloropropoxide.In the present invention,
Among these magnesium compounds, the average particle size is 20 to 10
A magnesium compound having a particle size distribution of 0 μ, preferably 20 to 60 μ, such that particles of 10 μ or less weigh 10 weight or less is used as the magnesium compound in preparing component (4).

In the above magnesium compound, the average particle size is 20μ
If the polypropylene particles produced are less than 1
A large amount of fine powder with a size of less than 50 μm is produced, which is unfavorable in terms of handling. On the other hand, when the average particle size of the magnesium compound exceeds 100 μm, coarse particles (1000 μm or more) of the polypropylene are produced, which tends to cause trouble in the production equipment. In addition, regarding the particle size distribution of the magnesium compound, it is preferable that there are no particles with a particle size of 10μ or less, but 1
If it is 0% by weight or less, the amount of fine powder in the obtained polypropylene particles is also small and can be suppressed to a level that does not cause any practical problems.

In the present invention, the above-mentioned magnesium compound is used and the component (4) of the catalyst is prepared by reacting this with a titanium compound. Various titanium compounds can be considered as the titanium compound used here, but usually the general formula is Ti(OR2)mX”4
Examples include halogen-containing tetravalent compounds represented by -m. Here, 几2 is an alkyl group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms.

It represents a cycloalkyl group, an aryl group, an alkenyl group, or an aralkyl group, and X2 represents a chlorine atom such as a chlorine atom, a bromine atom, or an iodine atom. Also, m is usually 0
, 1.2, or 3, but it does not necessarily have to be an integer, and may be a real number in the range of 0≦m<4 as an average value of a mixture of various titanium compounds. Specifically, these are Ti 014 .

TiBr4, TiI4 and other tetra/-titanium rogens, Ti(oca,)az, Ti(0(!q)
H5) C7a, Ti(0・n-C4H*)C7a
.

Torino-rogenated alkoxytitanium such as Ti(OC2H5)Br3, Ti(OCH3)20jQ,
Ti(OC2Hs)qo'* +Ti(0・n-04H
Ti(QC
! H8) s 01 .

'I'1(OC2H5)801.Ti(0'n-04
, H8) 3(J, Ti(00g, H,), Br, and other monohalogenated trialkoxytitaniums can be exemplified. It is preferable to use a containing material, and it is particularly preferable to use titanium tetrachloride (Ti014).

Component (4) of the catalyst used in the method of the present invention is prepared by reacting the above-mentioned magnesium compound with a titanium compound. The reaction conditions at this time are not particularly limited, but usually 1 mole of the magnesium compound is reacted with the titanium compound. Add a titanium compound in the range of 0.5 to 100 mol, preferably 1 to 50 mol, and react at 0 to 200°C for 5 minutes to 10 hours, preferably at 30 to 150°C for 30 minutes to 5 hours. let

This reaction can also be carried out using an inert solvent such as pentane, hexane, heptane, etc., if necessary. It is also effective to perform the above reaction in the presence of an electron donating compound, or to react the above magnesium compound with an electron donating compound in advance and reacting the resulting product with a titanium compound. You can also do it. The electron donating compound used here is usually an organic compound containing oxygen, nitrogen, phosphorus or sulfur. Specifically, amines and amides.

Examples include ketones, nitriles, phosphines, phosphoramides, esters, thioethers, thioesters, acid anhydrides, acid halides, aldehydes, and organic acids.

More specifically, organic acids such as aromatic carboxylic acids such as benzoic acid and p-oxybenzoic acid; acid anhydrides such as succinic anhydride, benzoic anhydride, and p-)ruyl acid anhydride; acetone and methyl ethyl ketone. .

Ketones having 3 to 15 carbon atoms such as methyl isobutyl ketone, acetophenone, pentuphenone, and benzoquinone;
Acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde.

2-1 carbon atoms such as tolualdehyde and nandaldehyde
Aldehydes of 5; methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, croton Ethyl acid, ethyl pivalate, dimethyl maleate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate.

Cyclohexyl benzoate dibenzoate [phenyl, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, ethyl p-butoxybenzoate.

Ethyl 0-chlorobenzoate 1 Ethyl naphthoate.

γ-butyrolactone, δ-valerolactone, coumarin,
Esters with a carbon number of 2 to 18 such as phthalide and ethylene carbonate; acids with a carbon number of 2 to 15 such as acetyl chloride, benzyl chloride, toluic acid chloride, anisyl chloride)・Rides: methyl ether, ethyl ether, isopropyl ether , n-butyl ether, amyl ether, tetrahydrofuran, anisole, diphenyl ether, ethylene glycol butyl ether, and other ethers having 2 to 20 carbon atoms; acetic acid amide, benzoic acid 7m'
)”,) acid amides such as lylic acid amide; tributylamine, N,N'-dimethylpiperazine.

tribenzylamine, aniline, pyridine, picoline,
Examples include amines such as tetramethylethylenediamine; carbon nitriles such as acetonitrile, benzonitrile, and tolnitrile; tetramethylurea, nitrobenzene, and lithium butyrate. Among these, preferable are esters, ethers, chthons 1w/anhydrides, and the like. In particular, alkyl esters of aromatic carboxylic acids, such as benzoic acid, p-methoxybenzoic acid.

Alkyl esters of aromatic carboxylic acids having 1 to 4 carbon atoms such as p-ethoxybenzoic acid and toluic acid are preferred, and aromatic ketones such as benzoquinone, aromatic carboxylic acid anhydrides such as benzoic anhydride, and ethylene glycol Ethers such as butyl ether are also preferred.

The amount of these electron-donating compounds to be used is not particularly limited and may be determined as appropriate depending on various circumstances, but is generally 0 to 10 mol, preferably 0 to 1 mol of the magnesium compound. It is selected within the range of .05 to 5 moles.

Component (4) of the catalyst used in the method of the present invention is prepared as described above, but it is also effective to repeat the reaction using the titanium compound described above, if desired.

In the method of the present invention, the reaction product thus obtained is thoroughly washed with an inert solvent such as bentane, hexane, heptane, etc., and used as component (4) (solid catalyst component) of the propylene polymerization catalyst.

According to the method of the present invention, a catalyst containing the above product (solid product) as the component (4), an organometallic compound as the component (B), and both components (3) and 03) as the main components Polymerization of propylene is carried out using Furthermore, these (4)
It is also effective to use a catalyst in which an electron-donating compound is added as component (0) to both components (B).

In producing polypropylene by polymerizing propylene, the reaction system contains a dispersion of the solid product as component (4), an organometallic compound as component 03), and, if desired, an electron donor as component (0). and propylene is then introduced into the system.

There are no particular restrictions on the polymerization method and conditions, and solution polymerization,
Both suspension polymerization and gas phase polymerization are possible, and both continuous polymerization and discontinuous polymerization are possible. For example, in the case of solution polymerization or suspension polymerization, the amount of the catalyst component added is 0.001 to 1 when the component (4) is converted to titanium atoms.
．． 0 mmol/l, preferably o, oos to 0.5 mmol/l, and the CB) component is 1 to 1000 (molar ratio), preferably 10 to 5, to the titanium atoms in component (4).
00 (molar ratio). In addition, it may be added as desired (the amount of Q component added is O~2 with respect to the titanium atom in component (4)).
00 (molar ratio), preferably 0.1 to 100 (molar ratio)
Should be. The propylene pressure in the reaction system is preferably normal pressure to 50 to 9/Cm2, and the reaction temperature is 30 to 200°C, preferably 50 to 150°C. Molecular weight adjustment during polymerization can be carried out by known means, such as hydrogen. The reaction time may be appropriately selected from 10 minutes to 10 hours, preferably from 30 minutes to 5 hours.

There are various organometallic and metal compounds which are component 03) of the catalyst used in the method of the present invention, and there are no particular restrictions.

The metals contained in this organometallic compound include metals of Groups 1 to 3 of the periodic table, such as lithium, sodium, potassium, zinc, and cadmium.

Among them, aluminum is particularly preferred. Specific examples of organometallic compounds include alkyllithiums such as methyllithium, ethyllithium, propyllithium, and butyllithium, and dimethylzinc, diethylzinc, and dipropylzinc.

There are dialkylzincs such as dibutylzinc, and organoaluminum compounds with the general formula AIR'kX'
8-k is widely used.

R8 is an alkyl group, cycloalkyl group, or aryl group having 1 to 10 carbon atoms, k is a real number between 1 to 3, and x3 represents a nitrogen atom such as chlorine or bromine. Specifically, trimethylaluminum, triethylaluminum, and triisoprobylaluminum. Trialkylaluminum compounds such as triimbutylaluminum and trioctylaluminum, and diethylaluminum monochloride.

Dialkylaluminum monolides such as diisopropylaluminum monochloride, dibutylaluminum monochloride, and dioctylaluminum monochloride are preferred, and mixtures thereof are also preferred.

In addition, in the method of the present invention, the electron-donating compound 1, which is the component (0) of the catalyst, may be used as needed in the preparation of the component (4) of the catalyst described above. Furthermore, in this case, the electron-donating compound as component (C) may be exactly the same compound as that used in the preparation of component (4) of the catalyst. , may be different. -1,
Examples include propylene copolymers copolymerized with α-olefins such as 4-methyl-pentene-1.

According to the method of the present invention, the activity of the catalyst used is extremely high, and the resulting polypropylene has high stereoregularity, resulting in a high product value. Moreover, since the magnesium compound in the solid catalyst component, which is component (4) of the catalyst, has a specific average particle size and particle size distribution, the resulting polypropylene has a relatively uniform particle size distribution. It has the advantage of being narrow, easy to handle, and having a high bulk density.

Therefore, the method of the present invention can be effectively used in producing polypropylene with excellent properties as described above.

Next, examples of the present invention will be shown. Note that all operations in the following examples were performed under an argon stream. Also,
The catalytic activity and stereoregular polymer yield (1, Y,) determined in the examples were defined as follows.

Catalyst activity: weight of total polymer produced in 2 hours (kg) per gram of titanium atom.

Example 1 (1) Preparation of solid catalyst component In a separable flask with an internal volume of 51, N-hair'tan 1500g, Mg(002HJQ100Q(0,
88 mol) and n-butyl benzoate 31.49 (0
, 18 mol) and raised the temperature to 40°C to form TiC! 741
6709 (8.8 mol) was added dropwise and reacted at 110°C for 2 hours, and the resulting reaction product was washed with n-heptane at 70°C to obtain a solid catalyst component. M used here
g(OCsH5)s had an average particle size of 57μ and contained 7% by weight of particles of 10μ or less.

The amount of titanium supported on the solid catalyst component obtained by the above procedure was measured by a colorimetric method, and it was found to be 35m9-Tl.
/Chu carrier.

(2) Production of polypropylene In a stainless steel autoclave with an internal volume of 11, 7400 ml of purified n-hebuta, Al(C!2H,),
2.0 mmol, A'(CsHa)Qat2. '0 mmol, methyl p-toluate o, s mmol and the solid catalyst component obtained in (1) above as Tl, 0.02 mmol! J mol was added and the temperature was raised to 70°C.

Next, hydrogen was added to the autoclave at a rate of 0.3 kg/cm2.
The polymerization reaction was carried out for 2 hours by introducing propylene so that the total pressure became 8.0 klil/cm2 G.

After the polymerization reaction was completed, the insoluble polymer was separated, and the solvent was evaporated from the p liquid to recover the soluble polymer. The insoluble polymer was Soxhlet extracted with boiling n-hebutane for 6 hours to remove the atactic polymer. The results are shown in Table 1.

Example 2 (1) Preparation of solid catalyst component In Example 1 (1), Kg(OOxHsh) having an average particle size of 50μ and a content of particles of 10μ or less was 6% by weight, and is Example 1 (
A solid catalyst component was prepared in the same manner as in 1). The amount of titanium supported on this product was 29 m9-T1/9-support.

(2) Production of polypropylene Polypropylene was produced in the same manner as in Example 1 (2) except that the solid catalyst component obtained in (1) above was used. The results are shown in Table 1.

Example 3 (1) Preparation of solid catalyst component In Example 1 (1), Mg(OC2:Hs)2
The average particle size is 50μ, the content of particles of 10μ or less is 7% by weight, and ethyl benzoate 27.09 (0,
A solid catalyst component was prepared in the same manner as in Example 1 (1) except that 18 mol) was used. The amount of titanium supported on this product was 31 m9-T1/g-support.

(2) Production of polypropylene Polypropylene was produced in the same manner as in Example 1 (2) except that the solid catalyst component obtained in (1) above was used. The results are shown in Table 1.

Comparative Example 1 (1) Preparation of solid catalyst component In Example 1 (1), Mg (OCiHs )Q
A solid catalyst component was prepared in the same manner as in Example 1 (1), except that a catalyst having an average particle size of 50 μm and a content of particles of 10 μm or less was 20% by weight. The amount of titanium supported in this product was 39 mg-Ti7g-carrier.

(2) Production of polypropylene Polypropylene was produced in the same manner as in Example 1 (2) except that the solid catalyst component obtained in (1) above was used. The results are shown in Table 1.

Comparative Example 2 (1) Preparation of solid catalyst component Except for using Mg(QCqHi) 2 in Example 1 (1) whose average particle size is 10 μ and the content of particles of 10 μ or less is 63% by weight. A solid catalyst component was prepared in the same manner as in (1). The amount of titanium supported on this product was 39m9-T1/Ku carrier.

(2) Production of polypropylene Polypropylene was produced in the same manner as in Example 1 (2) except that the solid catalyst component obtained in (1) above was used. The results are shown in Table 1.

Claims (1)

[Claims] (1) (4) In a method for producing polypropylene by homopolymerizing or copolymerizing propylene using a reaction product of a magnesium compound and a titanium compound and (B) a catalyst containing an organometallic compound as a main component, the general formula Mg
(0'''')n''i-H (wherein, R1 is an alkyl group, cycloalkyl group, or aryl group having 1 to 10 carbon atoms. It represents an alkenyl group or an aralkyl group, and X' represents a halogen atom. Also, n represents a real number from 1.0 to 2.0) and has a particle size distribution in which the average particle size is 20 to 100 μ and the proportion of particles of 10 μ or less is 10% by weight or less. A method for producing polypropylene, characterized in that it is used as a magnesium compound in component (4).The method according to claim 1, wherein the organometallic compound (21CB) is an organoaluminum compound.