JPS59147004A - Preparation of polyolefin - Google Patents

Abstract

PURPOSE:To obtain the titled polymer having extremely low formation of low- molecular-weight by-product, and improved productivity, by carrying out polymerization using a highly active catalyst consisting of a solid catalytic component containing Mg and Ti as a transition metal compound component and a specific oxygen-containing organoaluminum compound. CONSTITUTION:In polymerizing an olefin by using a catalytic system consisting of a transition metal compound component and an organoaluminum compound component, a solid catalytic component containing magnesium and titanium is used as the transition metal compound component, and an oxygen-containing organoaluminum compound or composition shown by the formula (R<1> and R<2> are alkyl, aryl, or cycloalkyl; X<1> is halogen; 1<=a<3; 0<b<=1; 0<=c<=2; a+b+c=3) is used as the organoaluminum compound component. Both the components are blended to give a catalyst, and an olefin is polymerized by the catalyst to give the desired polymer.

Description

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

More specifically, by using a specific cocatalyst for the solid catalyst component containing magnesium and titanium, it has high polymerization activity and extremely little generation of low molecular weight by-products (Excellent 7).
The present invention relates to a method for producing a polyolefin having productivity at °C.

Generally, when producing polyolefins by polymerizing ethylene and copolymerizing ethylene with other α-olefins,
Saturated or unsaturated hydrocarbon by-products with molecular weights ranging from tens to thousands are produced.

On the other hand, the rise in raw material costs resulting from the recent petroleum situation is having a significant impact on the economic efficiency of polyolefin production.

Therefore, if it is possible to reduce the production of low molecular weight by-products in the production of polyolefins, polyolefins can be produced with high productivity, which is an economic advantage.

In addition, reducing low molecular weight by-products in the polyolefin manufacturing process reduces adhesion to reactor walls and clogging of pipes, etc., making long-term continuous operation possible3.
Furthermore, it also gives favorable results to the physical properties of the product.

In view of the above circumstances, the present inventors conducted extensive studies and found that by using a transition metal compound component and a solid catalyst component containing organoaluminum compound sium and titanium, and using a specific oxygen-containing organoalkanium compound as the organoaluminum compound component, We have discovered a method for producing polyolefins that has high polymerization activity, produces very little low-molecular-weight byproducts, has excellent productivity, and does not adhere to the reactor during the production process (and can operate stably for a long time). The present invention has been achieved.

That is, the gist of the present invention is that when polymerizing olefins using a catalyst system consisting of a transition metal compound component and an organoaluminum compound component, a solid catalyst component containing magnesium and titanium is used as the transition metal compound component; As the general formula % formula % (wherein R1 and R2 represent an alkyl group, an aryl group or a cycloalkyl group, Xl represents a halogen atom, l≦a (3, O b≦7, O≦C≦ ,IL+
1) -1-Q == j. ) The present invention relates to a method for producing a polyolefin characterized by using an oxygen-containing organoaluminum compound or composition shown in (a).

To further explain the present invention in detail, in the present invention, a solid catalyst component containing magnesium and titanium as a transition metal compound component and an oxygen-containing organoaluminum compound or composition represented by the above general formula CI) as an organoaluminum compound as a cocatalyst. By using the above-mentioned compound, low molecular weight by-products can be reduced and the object of the present invention can be achieved.

In the general formula D), R1 and R2 each include alkyl, aryl, and cycloalkyl groups having up to about i3 carbon atoms, such as methyl, ethyl, furoyl, butyl, pentyl, hexyl, octyl, phenyl, tolyl, and cyclohexyl; Of course, R1 and R2 may be different.

Examples of xl include chlorine, bromine or iodine.

Specifically, Am Jl! t,,(OEft). ,C1,
alztl, 5 (0Bu). ,01,A'l Bu□,
, (0-Bu). ,,01,A10ct1.5(0-
Oct). ,,O'l,AI Elt2(OJl[it
), AI Bu2 (OBu ), AI It (OE
t). ,,91. ,,Alfftl,,(OEt)
. , Br, etc. can be mentioned. Among them, in general formula [I], a = /, j, b = = 0.3%c
= / is preferable, and AI Itl, 5(OK
t). , , C1 are particularly preferred.

Preferable examples of the solid catalyst component containing magnesium and titanium include the following (A) to (0).

(A) Reaction product of an oxygen-containing organic compound of magnesium, an oxygen-containing organic compound of titanium, and an aluminum halide compound (B, l A reaction product of an oxygen-containing organic compound of magnesium, an oxygen-containing organic compound of titanium, and a silicon halide halide compound) Reaction products CA) to (C) will be explained below, but in the method of the present invention, the solid catalyst component is not limited to the above CA) to CC). Known catalyst components such as products obtained by treatment with titanium norogen compounds after or during treatment can also be used in the process of the invention.

The oxygen-containing organic compound of magnesium used in preparing the reaction product of CA) catalyst component manufacturing method (A) is Mg(OR3)mX.
Lid-rn (In the formula, R3 represents an alkyl group, an aryl group, or a cycloalkyl group, and X2 represents a)-rogen atom, and m is l or co. ) Examples include magnesium jetoxide, magnesium jetoxide, magnesium diphenoxide, magnesium monoethoxy chloride, magnesium monophenoxy chloride, magnesium monoethoxypromide, magnesium monoethoxy chloride, and the like.

Among these, magnesium jetoxide is preferred.

As an oxygen-containing organic compound of titanium, the general formula T i' (
OR')nXi-n (wherein X3 represents a halogen atom, R4 represents an alkyl group, aryl group or cycloalkyl group, and n is / to l);
For example, tetraethoxytitanium, tetra-n-butoxytitanium, jetoxydichlortitanium, di-n-butoxydichlortitanium, triethoxymonochlortitanium, tri-n-butoxymonochlortitanium, ethoxytrichlortitanium, n-butoxytrichlortitanium, Examples include methoxytribromotitanium. Among these, tri-n-butoxymonochlorotitanium is preferred.

As an aluminum halide compound, the general formula AIR%
X to p (wherein R5 represents an alkyl group, aryl group or cycloalkyl group, x4 represents a halogen atom,
Examples of compounds represented by o (p (J)) include ethylaluminum dichloride, ethylaluminum sesquichloride, diethylaluminum monochloride, n-propylaluminum dichloride, and the like.

Among these, ethylaluminum sesquichloride is preferred.

For the reaction of the above compounds, first, an oxygen-containing organic compound of magnesium and an oxygen-containing organic compound of titanium are mixed,
A uniform liquid is prepared by heating to 0°C to /40°C. When it is difficult to produce a uniform liquid, it is preferable to include alcohol. Examples of the alcohol include ethyl alcohol, n-butyl alcohol, and 11-octyl alcohol.

An inert hydrocarbon solvent is then added to form an inert hydrocarbon solution.

When an aluminum halogen compound is added to the inert hydrocarbon solution obtained as above and reacted at room temperature to 100°C, the reaction product is obtained as a precipitate, and the unreacted material is washed with an inert hydrocarbon solvent. removed.

The ratio of each component is the molar ratio of titanium compound to magnesium compound (Ti/Mg) of 6. i to IQ1 It is preferable that the aluminum halogen is no λO with respect to the sum of the number of moles of the magnesium compound and the number of moles of the titanium compound.

Manufacturing method of catalyst component (B) The oxygen-containing organic compound of magnesium and the oxygen-containing organic compound of titanium used in preparing the reaction product of (B) can be those used in the preparation of (A). It is.

The silicon halogen compound has the general formula R (where R6 represents an alkyl group, an aryl group, or a cycloalkyl group, x5 represents a halogen atom, and O≦
q≦2. ) is used. Among these, compounds in which x5 is chlorine are preferred. Examples include silicon tetrachloride, methyltrichlorosilane, ethyltrichlorosilane, phenyltrichlorosilane, diethyldichlorosilane, etc. Particularly preferable results are obtained by using a chlorinated silicon compound with q=o, that is, silicon tetrachloride.

In the reaction of these compounds, the reaction of the oxygen-containing organic compound of magnesium and the oxygen-containing organic compound of titanium is obtained in the same manner as in the reaction for preparing the catalyst in (A). When a silicon halogen compound is added to the inert hydrocarbon solution obtained in this way and reacted at room temperature to 00°C, the reaction product is obtained as a precipitate, and unreacted substances are washed with an inert hydrocarbon solvent. removed.

In addition, the quantitative ratio of each component is the molar ratio of the titanium compound to the magnesium compound (Ti/Mg), which is Q, / ~ IQ, and the silicon halide compound to the phase of the number of moles of the magnesium compound and the number of moles of the titanium compound ~ λO. Correct.

The oxygen-containing organic compound of magnesium used in preparing the reaction product of method (0) for producing the catalyst component in (C) can be the same as that used in (A).

The titanium halide has the general formula TiXLf (○R7), r (wherein, X'&i C
1key W represents a child, R7 represents an alkyl group, an aryl group or a cycloalkyl group, and r is l-μ.

, ) Examples include titanium tetrahalides such as titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, monoethoxytrichlortitanium, monoethoxytrichlortitanium, jetoxydichlorotitanium, and the like. Among these, titanium tetrahalide is preferred.

The reaction between the oxygen-containing organic compound of magnesium and the titanium halide compound is carried out by contacting the two in the presence or absence of an inert hydrocarbon solvent at a temperature of 10°C to 200°C. The reaction product is obtained as a precipitate, and unreacted substances are washed away with an inert hydrocarbon solvent. There is no particular limit to the atomic ratio of titanium to magnesium in the reaction ratio between the two, but if it is too large, titanium will be wasted, and if it is too small, the polymerization activity will decrease.

Therefore, usually Ti/Mg=0. /~1OO (molar ratio) is preferable.

The ratio of the solid catalyst component containing magnesium and titanium to the oxygen-containing organoaluminum compound is usually A1/T.
The atomic ratio of i is 0.1-100, preferably / -j
Used within the range of O.

The catalyst system thus prepared is used to polymerize olefins, and the olefins used in the process of the invention include ethylene, propylene, butene-7, pentene-7.
Examples include α-olefins such as 11 octene-7. Moreover, these olefins can also be mixed and copolymerized. Among other things, the process of the invention is advantageous for the production of ethylene homopolymers or copolymers of ethylene, preferably containing up to j moles of other alpha-olefins.

The polymerization reaction can be carried out by solution polymerization or slurry polymerization carried out in an inert solvent or liquefied monomer, or by gas phase polymerization carried out in the absence of a solvent. Normally,
This is carried out by maintaining a predetermined temperature and pressure while supplying an olefin or olefin mixture in the presence of an inert solvent.

As the inert solvent, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, and isooctane, and aromatic hydrocarbons such as benzene and toluene are used.

The polymerization reaction is usually carried out at a temperature of from room temperature to 200°C and from normal pressure to
It is selected from within the pressure range of 1000 atmospheric pressures.

Further, in the method of the present invention, when hydrogen is present in the polymerization reaction zone, the effect of controlling the molecular weight by hydrogen is large, and a polymer having a desired molecular weight can be easily obtained.

The amount of hydrogen to be present varies depending on the polymerization conditions, the desired molecular weight of the olefin polymer, etc., so it is necessary to appropriately adjust the amount of hydrogen to be introduced depending on these factors.

Further, the method of the present invention can be carried out in a method in which the polymerization reaction is carried out in one stage or in a multi-stage polymerization method in which two or more stages are carried out, but the effectiveness of the method of the present invention is particularly great in the case of a multi-stage polymerization method.

That is, for example, in one of the first and second reaction zones, the molar ratio to ethylene in the gas phase is θ,00/~゛! Polymer A with a viscosity average molecular weight /j of 10,000 to 1,000,000 is produced in an amount of 70% to 70% by weight of the total polymer production, and in the other zone, In molar ratio, j~
Polymerization is performed in the presence of 70% hydrogen to produce Polymer B having a viscosity average molecular weight of 10,000 to 30,000% by weight relative to the total polymer production amount, and further (viscosity average molecular weight of Polymer A). /(
The viscosity average molecular weight of Polymer B is <z −y o, and the melt index of the entire polymer to be finally produced is 0.1.
In particular, in cases such as a two-stage polymerization method where polymer B is less than
The method of the present invention is extremely effective because a large amount of low molecular weight by-products are produced when there is a large amount of hydrogen, which is a molecular weight regulator, such as in the production of.

By using the cocatalyst according to the method of the present invention as described above in producing polyolefins, the amount of low molecular weight by-products produced is extremely small (it has excellent productivity, and there is no problem such as adhesion to the reactor during the production process). It has various advantages such as being favorable for long-term stable operation and having high polymerization activity.
can get.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

In the examples, the polymerization activity (abbreviated below) of the catalyst is K=C
9 polymer)/(g catalyst) (hl (kg/cIt olefin pressure).

In addition, the melt index (hereinafter abbreviated as M) is AST
Based on MD-/231-t7T at 0°C, 2. /
& Yu load was measured. Furthermore, the flow rate ratio (hereinafter abbreviated as PR) as a measure of molecular weight distribution is a value indicating the dependence of melt viscosity on shear stress, and according to ASTM D-/231-j7TK, shear stress '0' eLTne/cr/( and/0
It represents the outflow ratio of molten polymer in 1yne/crl, and it is said that the larger F'R is, the wider the molecular weight distribution is, and the smaller F'R is, the narrower it is.

Further, the amount of low molecular weight by-products was measured by the method shown below.

(1) After completion of quantitative polymerization of by-product grease wax (abbreviated as GW), a portion of the polymer slurry was taken out, the solvent was distilled off, and extraction was carried out at 3 o'clock in a dryer at tro° C. for 2 hours.

The soluble portion in refluxed normal hexane was defined as a by-product grease wax as follows.

Rm normal sanophilic soluble fraction ff1 GW = total polymer weight X 100-4i%
(2) After quantitative polymerization of the by-product high boiler (abbreviated as HB), the polymer slurry is allowed to stand, a portion of the supernatant liquid is taken out, and the number of carbon atoms soluble in the polymerization solvent is saturated to r~3.2. Alternatively, the unsaturated hydrocarbon component was measured using a gas chromatography manufactured by Takasugi Seisakusho (G (3-Hiro BMI?11')) and was determined as 5 as shown below.

×100 = Heavy weight example/~3 Magnesium jet oxide//! fl and tri n-butoxymonochlorotitanium izig and n-butanol 37
g and were mixed at 14Lo°C for 6 hours to homogenize. Then, the temperature was lowered to tO'C and benzene was added to obtain a homogeneous solution. Next, add ethylaluminum sesquichloride at μO℃! μg was added dropwise, the temperature was raised to 60° C., and the mixture was stirred for 1 hour. The catalyst component was obtained by washing with the formed precipitated n-hexane.

A part of the obtained solid slurry was dried and analyzed, and it was found that this solid contained Mg#''-10.1% by weight, T1
It contained 10.0% by weight.

Next, add 100% normal hexane to the λ autoclave.
0 cc was taken and the above catalyst component/Q■ was charged. 0℃
After raising the temperature to , a predetermined amount of hydrogen is introduced, and A'1EitL, (
Ollft). ,,Ol O,/4 mmox is introduced together with ethylene and the total pressure is 2-? krd (gauge pressure) K [. Ethylene absorption was observed as ethylene was introduced, but ethylene was additionally introduced so as to maintain the total pressure at 23 kVCIL, and after 1 hour, the polymerization was stopped by injecting a small amount of ethanol. The results obtained are shown in Table 1.

Example μ In Example/AIBHt, 5 (omt). 1. C
The same procedure was performed except that AIKt (O]Dt )C]- was used instead of 1.

The results obtained are shown in Table 1.

Example! AIEtL5(O]1Dt) in Example/. ,,C
A 11Bul instead of 1, 5(Of-iBu)6,
I used 501 and did it in exactly the same way except for 5. The results obtained are shown in Table 7.

Example t,! 1 O 1-Normal hexane in crepe/,000
cc was taken, and 23 m9 of the catalyst component obtained in Example 1 was charged. After raising the temperature to 0°C, hydrogen was introduced to /r,3 up to AIKt1. , (omt). ,,010,μ0m1
No.1 was introduced together with ethylene, and the total pressure was -2jklVcv.
t (gauge pressure). Ethylene absorption was observed as ethylene was introduced, but ethylene was additionally introduced to maintain the total pressure at 2 r kg/d, and the introduction of ethylene was stopped after 55 minutes. During this time, 23°Cg of ethylene was absorbed. Then the total pressure /, ? k! ? /ffl
(gauge pressure) and simultaneously cooled to g0℃, then 4t of l-butene, ♂I was introduced together with ethylene, and the total pressure was set to a, Ok! ? /i (gauge pressure), and the first stage polymerization was started. Ethylene is additionally introduced as in the first stage, and j! After 2.3 All of ethylene was absorbed, the polymerization was stopped by injecting a small amount of ethanol.

The results obtained are shown below.

1st stage K == / UO Hydrogen/ethylene (gas phase molar ratio) = 3. lrλth stage K=≠, SOO Hydrogen/ethylene (gas phase molar ratio)=O,, 2a The obtained polymer has M engineering=0.34! FR'= 13()W
=J, 7% by weight HB=0.71% by weight.

Example 7 7 g of magnesium jetoxide J and 410 g of tri-n-butoxymonochlorotitanium were mixed at 130° C. for 6 hours and homogenized.

Next, the temperature was lowered to 60°C, benzene was added to make a homogeneous solution, and then silicon tetrachloride was added dropwise in the evening at 50°C, followed by stirring for 3 hours and ripening. The generated precipitate was washed with normal hexane to obtain a catalyst component. Polymerization was carried out in the same manner as in Example 1 except that the catalyst component obtained in the above manner was used.

The results obtained are shown in Table 2.

Example r Magnesium jetoxide 10g and titanium tetrachloride 70M
and were reacted at 30° C. for 1 hour.

After cooling, the catalyst component was obtained by washing with 11-hexane. Polymerization was carried out in exactly the same manner as in Example 1 except for using the catalyst component thus obtained. The results obtained are shown in Table 2.

Comparative Example 1 In Example 1/A1Et1. , (OEt,). ,,
The same procedure was performed except that A'1Fit3 was used instead of 010.

The results obtained are shown in Table 3.

Comparative Example J AIEit, 5 (OKt) in Example 1. ,,C
The same procedure was performed except that A11l:t20'l was used instead of A11l:t20'l.

The results obtained are shown in Table 3.

Comparative Example 3 Example 1p K Oite AIEtL, (OEt). , 50
1 (7) Polymerization was carried out in exactly the same manner except that AIJlnt201 was used instead.

The results obtained are shown below.

7th stage K=-20K O Hydrogen/ethylene (gas phase molar ratio) = 3. Zako step
K=4L to 30 Hydrogen/Ethylene (vapor phase molar ratio)=O1λμ Comparative Example μ In Example 7, A: LKtl,, (0Elt). ,
The same procedure was performed except that Alfflt, 01 was used instead of 5C1.

The results obtained are shown in Table 3.

Comparative Example j In Example g, Actl. , (ogt). ,,
AIFlit2C instead of C1! The procedure was carried out in exactly the same manner except that 'l was used.

The results obtained are shown in Table 3.

Table 1 Table - Table Table 3

Claims (4)

[Claims] (1) When polymerizing olefins using a catalyst system consisting of a transition metal compound component and an organic aluminum compound component, a solid catalyst component containing magnesium and titanium is used as the transition metal compound component, and the organic aluminum compound component has the general formula AIR1a(OR2)bXlc
(In the formula, R1 and R2 represent an alkyl group, an aryl group, or a cycloalkyl group, XI represents a halogen atom, and 7≦a (3, o < b≦/, Q≦C≦λ, a
-1-b -1-c = 3. ) A method for producing a polyolefin, characterized by using an oxygen-containing organoaluminum compound or composition. (2) Organic aluminum, the compound component is AIRI,
, (oR2)o, 6Σ (wherein R1 and R2 represent an alkyl group, an aryl group, or a cycloalkyl group, xl
)) represents a rogen atom. ) The method according to claim 1, which is a compound or composition represented by: (3) The organic aluminum compound component is AI ItL6
(01t)0.601 The method according to claim 7 or 2, which is a compound or composition represented by (01t)0.601. (4) The method according to any one of claims 1 to 3, wherein the transition metal compound component is a reaction product selected from the following group. (A) Reaction product between an oxygen-containing organic compound of magnesium, an oxygen-containing organic compound of titanium, and an aluminum halogen compound CB) A reaction product of an oxygen-containing organic compound of magnesium, an oxygen-containing organic compound of titanium, and a silica halogen compound CC) Reaction product of magnesium oxygen-containing organic compound and titanium halogen compound