JPH03190909A - Polymerization of alpha-olefin - Google Patents

Abstract

PURPOSE:To obtain the title polymer without making an oligomer as a by- product by polymerizing an olefin using a highly active Phillips type catalyst comprising a solid prepared by supporting a Cr compound on an inorganic oxide and baking and an inactive hydrocarbon-soluble organomagnesium complex compound. CONSTITUTION:An olefin is polymerized by using a catalyst comprising (A) a solid component prepared by supporting a chromium compound (e.g. chromium trioxide) on an inorganic oxide (e.g. silica) and baking and (B) an inactive hydrocarbon-soluble organomagnesium complex compound shown by the formula [alpha and beta are integer larger than 0; p, q, r, s and t are 0 or larger than 0, 0<=(s+t)/(alpha+beta)<=1.5 and p+q+r+s+t=malpha+2beta (m is valence of M); M is Zn, B, Be or Li) R<1> to R<3> are 1-20C hydrocarbon; X and Y are OR<4> (R<4> is H or hydrocarbon, OSiR<5>R<6>R<7> (R<5> to R<7> are as shown for R<4>), etc. ] and prepared by blending in a molar ratio of (M+Mg)/Cr of 0.1-10 to give the objective polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process for the polymerization of olefins, particularly ethylene or ethylene and other α-olefins.

Specifically, the present invention is an improvement with high activity characterized by using a catalyst obtained by contacting a solid consisting of a chromium component supported on an inorganic oxide and a component containing a specific organomagnesium. The present invention relates to a method for polymerizing olefins.

(Prior Art) An ethylene polymerization catalyst obtained by supporting a chromium compound such as chromium oxide on an inorganic oxide carrier such as silica or silica alumina and firing it is widely known as a so-called Phillips type catalyst.

However, when using this catalyst, the activity of the catalyst and the average molecular weight of the polymer greatly depend on the polymerization temperature, and it is difficult to obtain a commercially available polymer with a molecular weight of tens of thousands to hundreds of thousands with sufficient catalytic activity. In order to manufacture it, the polymerization temperature must be set at 100~
It was necessary to raise the temperature to 200°C.

When polymerization is carried out in such a temperature range, the produced polymer is dissolved in the reaction solvent, so the viscosity of the reaction system increases significantly, and as a result, the concentration of the produced polymer decreases by 2.
It was difficult to get the amount above 0%. Therefore, there has been a strong demand for the development of a catalyst that exhibits high catalytic activity at a polymerization temperature of +00'C or less, where polymerization is so-called slurry polymerization.

Furthermore, in order to reduce production costs, it is important to be able to omit the catalyst removal step in the post-polymerization process, and for this purpose, it has been necessary to develop a catalyst that exhibits even higher activity.

Therefore, in order to improve the polymerization activity of this Phillips-type catalyst, organic aluminum compounds, organic zinc compounds, etc. were added to M4.
Many catalyst systems have been proposed (for example, Japanese Patent Publication No. 36-22144, Japanese Patent Publication No. 43-27415, Japanese Patent Publication No. 47-23668, Japanese Patent Publication No. 49-34
No. 759, etc.), efforts have been made to improve the catalytic activity.

Furthermore, a catalyst system comprising a combination of a Fili-impus type catalyst and an organomagnesium complex compound has been disclosed (for example, Japanese Patent Publication No. 59-5602, Japanese Patent Publication No. 59-5604, Japanese Patent Publication No. 59-50242, etc.). , Furthermore, the catalytic activity has been improved.

(Problem H to be solved by the invention) However, although the invention described in the above-mentioned Japanese Patent Publication No. 59-5604 is an excellent technique with improved catalytic activity, a large amount of oligomers and wax components are added as by-products during polymerization. There were some drawbacks. This was a major problem to be solved from the viewpoint of cost and stable operation of the process.

(Means for Solving the Problems) As a result of various studies regarding the above problems, the present inventors have developed a solid product obtained by calcination activation of a chromium compound supported on a carrier such as silica, and a specific organomagnesium compound. In the catalyst system described in Japanese Patent Publication No. 595,604, in which the two are combined, it has been discovered that the generation of oligomers and wax components can be significantly reduced by contacting the two in advance and using them for polymerization, and the present invention has been achieved based on this discovery.

That is, the present invention comprises; (a) a solid component obtained by supporting and calcining a chromium compound on an inorganic oxide carrier; and (b) an inert hydrocarbon-soluble organomagnesium complex compound (in the formula , α, β are larger numbers than O, and p, 9, r
, s, t are 0 or greater than O, and 0≦(s+t)/(α
1β)≦1. 5 and p+q+r+s+t=mα+2β
M is an atom selected from zinc, boron, helium, and lithium, m represents the valence of M, and R1, R2, and R3 are the same or different carbon atoms from 1 to
20 hydrocarbon groups, X and Y are the same or different OR', 03iR5R6R
7. represents a group selected from NRBR9 and 5RIQ, R', R5, R'=, R', RIl, R9 are hydrogen atoms or hydrocarbon groups, and Rlo represents a hydrocarbon group). In the olefin polymerization method using
．． The present invention relates to a method for polymerizing olefins, which is characterized in that they are used in the polymerization by contacting in a range of 1 to 10.

The present invention will be explained in detail below.

As the inorganic oxide carrier used in the present invention, silica, silica-alumina, thoria, zirconia, etc. can be used, but silica and silica-alumina are particularly preferred.

Examples of supported chromium compounds include chromium oxides, halides, oxyhalides, nitrates, sulfates, oxalates, acetates, alcoholades, etc. Specifically, chromium dioxide, chromyl chloride, Potassium dichromate J1, ammonium chromate, chromium nitrate, chloroacetate
1. Compounds that form chromium oxide at least partially with chromium acetylacetonate. Chromium trioxide, chromium acetate, and chromium acetylacetoner I. are particularly preferably used.

Next, supporting and firing of the chromium compound will be explained.

The chromium compound can be supported on the carrier by known methods such as impregnation, solvent distillation, and sublimation deposition. The amount of chromium supported is 0% by weight of chromium atoms relative to the support.
．． It ranges from 0.05% to 5%, preferably from 0.1% to 3%.

Firing activation is generally performed in the presence of oxygen, but it can also be performed in the presence of an inert gas or under reduced pressure. Preferably, air substantially free of moisture is used.

Firing temperature is 300°C or higher, preferably 400-900°C
°C for several minutes to several tens of hours, preferably 30 minutes to 10
Time is done. It is recommended to supply sufficient dry air during firing and to perform firing activation in a fluidized state.

Of course, it is also possible to use a known method in which the activity, molecular weight, etc. are adjusted by adding titanate necks, fluorine-containing salts, etc. at the time of supporting or firing.

Next, the inert hydrocarbon soluble organomagnesium complex compound represented by the general formula: % formula % used in the present invention will be explained.

-1- In the formula, M is an atom selected from zinc, boron, beryllium and lithium, and particularly preferably zinc.

The hydrocarbon group represented by R1, Rz, and Ri is an alkyl group, a cycloalkyl group, or an aryl group, such as methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, decyl, dodecyl, cyclohexyl, phenyl. groups, etc., and alkyl groups are preferably used.

The polar group represented by X1Y is an alkoxy group, a siloxy group,
It is an amino group or a sulfide group, preferably an alkoxy group or a siloxy group.

The ratio of polar groups to metal atoms (s+t)/(α+β) is 0 or more and 1.5 or less, preferably 1 or less.

The inert hydrocarbon-soluble organomagnesium complex compound described above is synthesized according to the published publications and publications of the present applicants. (For example, Tokuko Sho 52-36
Publication No. 791, Special Publication No. 5236796, Special Publication No. 5
Publication No. 6-43046, etc. ) Examples of the inert hydrocarbon medium include aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as henzene and l.luene; and alicyclic hydrocarbons such as didichlorohexane and methylcyclohexane. Hydrocarbons or cycloaliphatic hydrocarbons are preferably used.

Next, a method of bringing the solid catalyst component (ie, the chromium-containing solid supported on a carrier and activated by firing) into contact with the organomagnesium component will be described.

In the contact method, the organomagnesium complex component may be added to a solid catalyst component suspended in a hydrocarbon medium, or the solid catalyst component may be added to an organomagnesium complex.

In the present invention, the effect of the present invention, that is, the effect of reducing oligomer wax by-products, is obtained by bringing the solid catalyst component and the organomagnesium complex component into contact with each other in advance, and at that time, the molar ratio of the two is within a specific range. It is important for

The molar ratio of both metals as (Mg+M)/Cr is 0.
The range is from 1 to 10, preferably the range from 1 to 5 is used.

There are no particular limitations on the contact concentration and the contact temperature, and the temperature can be within the commonly used range of room temperature to 100°C. Examples of the contact medium include aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as benzene and l-luene; alicyclic hydrocarbons such as dichlorohexane and medylcyclohexane; Hydrogen or alicyclic hydrocarbons are preferably used.

Next, a method for polymerizing olefin using the catalyst of the present invention will be explained.

Olefins that can be polymerized using the catalysts of the invention are alpha-olefins, especially ethylene. In general, the catalyst of the present invention contains ethylene, propylene, butene-1, hexene-1
It is also possible to use it for copolymerization with monoolefins such as, or in the presence of dienes such as butadiene and isoprene.

By carrying out copolymerization using the catalyst of the present invention, it is possible to produce a polymer having a density in the range of 0.9'' to 0.97 g/cffl.

As the polymerization method, usual suspension polymerization, solution polymerization, and gas phase polymerization are possible. In the case of suspension polymerization and solution polymerization, the catalyst is a polymerization solvent such as aliphatic hydrocarbons such as propane, butane, pentane, hexane, and heptane; aromatic hydrocarbons such as benzene, toluene, and xylene; Ethylene is introduced into the reactor together with an alicyclic hydrocarbon such as hegizane, and ethylene is
The polymerization can be carried out at a temperature of room temperature to 320° C. by injecting 200 kg/cIIi under pressure.

On the other hand, in gas phase polymerization, ethylene is added at 1 to 50 kg/cTFl.
Polymerization can be carried out at a pressure of from room temperature to 120'C using means such as a fluidized bed, moving bed, or stirring to ensure good contact between ethylene and the catalyst. It is.

The catalyst of the present invention has high performance and can be used at 85°C110kg/
It exhibits sufficiently high activity even under relatively low temperature and low pressure polymerization conditions of approximately cJ, and little oligomer or wax content is produced as by-products during polymerization. Since the polymer produced in this case exists in the polymerization system in a slurry state, the increase in viscosity of the polymerization system is extremely small.

Therefore, the polymer concentration in the polymerization system can be reduced to 30% or more, and the amount of by-products such as oligomers and wax is small, so there are great advantages such as reduction in manufacturing costs and improvement in production efficiency. Furthermore, due to its high activity, the step of removing catalyst residue from the produced polymer can be omitted.

The polymerization may be carried out by conventional one-stage polymerization using one reaction zone, or by so-called multi-stage polymerization using a plurality of reaction zones.

2 The polymer polymerized using the catalyst of the present invention has a wide molecular weight distribution even in normal one-stage polymerization, and has a relatively high molecular weight.
Extremely suitable for blow molding and film forming applications.

Multi-stage polymerization, in which polymerization is carried out under two or more different reaction conditions, makes it possible to produce polymers with a wider molecular weight distribution.

Adjustment of polymerization temperature to adjust the molecular weight of the polymer,
Of course, it is also possible to use known techniques such as adding hydrogen to the polymerization system or adding an organometallic compound that tends to cause chain transfer. Furthermore, it is also possible to carry out polymerization by combining methods such as adding a titanate ester to control density and molecular weight.

Examples of the present invention will be shown below, but the present invention is not limited to these Examples in any way.

In addition, ■catalytic activity in the examples refers to monomer pressure of 10k
In g/cfl, chromium in the solid catalyst is expressed as the amount of polymer produced (g) per hour.

■ Ml represents melt index, ΔSTM-D-
1238, at a temperature of 190° C. and a load of 216 kg.

(2) FR is the quotient obtained by dividing the value measured at a temperature of 190° C. and a load of 21.6 kg by Ml, and is known to those skilled in the art as an index representing the breadth of molecular weight distribution.

■ The amount of by-produced oligomers is expressed by selecting 1-hexene as a representative of the by-produced oligomers and expressing it as a ratio (wt%) to the polymer produced in the reactor after polymerization.
-Hexene was analyzed by gas chromatography.

■ The amount of wax is determined by the hot heptane solution (wt) in the polymer.
%).

(Example 1) (1) Synthesis of solid component (al): 0.4 g of chromium trioxide was dissolved in distilled water BOmft, and silica (Fuji Davison Grade 952) was added to this solution.
) 20g was immersed and stirred at room temperature for 1 hour. This slurry was heated to distill off the water and then heated to 120'C for 1
Drying was carried out under reduced pressure for 0 hours. This solid was dried under a stream of dry air for 6
The solid component (a) was obtained by firing at 00°C for 5 hours. The obtained solid component (a) contained 1% by weight of chromium and was stored at room temperature under a nitrogen atmosphere.

(2) Synthesis of organomagnesium component (b) 13.80 g of n-butylmagnesium and 2.06 g of diethylzinc
By putting 200 g of n-Hagekun into a 500 ml flask and reacting at 80°C with stirring for 2 hours, the composition nMgb(C2H5)z(n
An organomagnesium complex corresponding to C4H7)+2,
It was obtained as a solution containing 117 mmol (Zn+Mg).

(3) Solid component (a) and organomagnesium complex (+))
contact with.

5 g of solid component (a) obtained in (1) (Cry, 96 mm
.

1) was suspended in 100 mfl of n-heptane, and under stirring at room temperature, the organomagnesium complex solution obtained in (2) was added to (Z
2.94 mmo+ on the basis of (Zn+Mg), i.e. (Zn+Mg)
)/Cr molar ratio equivalent to 3.0, and the mixture was reacted for 1 hour.

(4) Polymerization: 2On+g of the solid obtained in (3) was dehydrated and deoxygenated to give 0.8! At the same time, the inside was vacuum degassed and replaced with nitrogen 1.
It was placed in a 5P reactor. Maintain the internal temperature of the reactor at 85°C, add 10 kg/cffl of ethylene, and reduce the total pressure to 1 with hydrogen.
It was set to 4kg/c+1. By replenishing ethylene, polymerization was carried out for 2 hours while maintaining the total pressure at 14 kg/CIfl.
00g of polymer was obtained.

Catalyst activity is 500.000g polymer/gCr-hr
The amount of oligomer was 0.2 wt%, the amount of wax was 3.7 wt%, Ml of the polymer was 0.28, and FR was 140.

(Example 2) Composition synthesized in Example 1: A heptane solution containing 50 mmol (based on Mg+Zn) of an organomagnesium complex of 6 ZnMg6(CzHs)z(n-Ca H9L2) was placed in a 200-ml flask. A heptane solution containing 25 mmol of n-hexyl alcohol was added dropwise to this solution over 30 minutes with stirring at 10°C.A portion of this solution was separated, oxidized with dry air, and then hydrolyzed. , alkyl groups and alkoxy groups were all alcohols, and analyzed by gas chromatography.Ethanol, n-buknol, n
-The composition of the above complex is determined from the analytical value of hexyl alcohol.
ZnM g 6(C2HsL, 6o(n Ca HJ
n, q.

It was found that (0,,C6Hl3)s,so.

Using this alkoxy-containing organomagnesium complex solution as the organomagnesium component (b), catalyst synthesis and polymerization were carried out in the same manner as in Example 1, and 220 g
of polymer was obtained.

Catalyst activity is 550,000g polymer/gCr-hr
The amount of oligomer is 0.31 wt%, and the amount of wax is 3. 2 wt%, the Ml of the polymer was 0.41, and the PR was 150.

(Comparative example) 20 mg of the solid component synthesized in (1) of Example 1 and (2)
Organomagnesium component synthesized in 0. ], mmol [
This is (Z n + M g )/Cr molar ratio 26
Polymerization was carried out in the same manner as in Example 1, except that the polymer was placed in the reactor without prior contact with [corresponding to]].

The polymerization results were as follows: polymer yield was 260 g, catalyst activity was 650.000, oligomer amount was 2.5 wt%, wax amount was 13.0 wt%, MIo was 32, and FR was 150.

(Examples 3 to 11) Ethylene polymerization was carried out in the same manner as in Example 1 except that the components and amounts of the organomagnesium complexes in Examples 1 and 2 were changed. The results are shown in Table 1.

(Example 2) In the synthesis of solid components, C. Rosfreld, UK
Grade EP 2 manufactured by Catalys ts
00 (Cr O, 6 呵χ, 8E O.

Catalyst synthesis and polymerization were performed in the same manner as in Example 1, except that silica containing 9wtχ was used and the calcination temperature was 800°C.

The polymerization result was a polymer yield of 210 g and a catalyst activity of 87.
, 500, oligomer amount 0.2w%, wax amount 3.
7 wt%, and the polymer MIo,32,FRl,2
It had 0.

(Example 13) A mixed gas of ethylene and 1-butane containing 15 mo 1% of 1-butene was used instead of ethylene, and isobutane was used instead of hexano as a polymerization solvent.
Mixed gas partial pressure at °C], Okg/cfl, hydrogen partial pressure 1 kg/a6, 23 kg/a6 including solvent vapor pressure
cfI, and using the catalyst of Example 12, polymerization was carried out in the same manner as in Example 1.

The polymerization result was a polymer yield of 190g and a catalyst activity of 79g.
2.000, the oligomer amount Q was 3 wt%, it was MIO122 of 9 poly(7-), and the density was 0°0925.

(Effect of the invention) In the present invention, as a catalyst for α-olefin polymerization,
By using a highly active Phillips-type catalyst obtained by subjecting a chromium component supported on an inorganic compound to a contact reaction with a specific organic magnesium compound in advance, the effect of reducing the production of by-products such as oligomers can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic flowchart illustrating aspects of the invention. (1 other person)

Claims (3)

[Claims] (1) (a) A solid component obtained by supporting and firing a chromium compound on an inorganic oxide carrier, (b) General formula (M) α (Mg) β (R^1)_p(R^2)_q(R
^3) Inert hydrocarbon soluble organomagnesium complex compound represented by _rX_sY_t (where α, β are numbers larger than 0, p, q, r
, s, t are 0 or greater than 0, and 0≦(s+t)/(α
+β)≦1.5 and p+q+r+s+t=mα+2β, M is an atom selected from zinc, boron, beryllium, and lithium, m represents the valence of M, R^1, R^2, R^3 is the same or different hydrocarbon group having 1 to 20 carbon atoms, and X and Y are the same or different OR^4, OSiR^5R
Represents a group selected from ^6R^7, NR^8R^9 and SR^1^0, where R^4, R^5, R^6, R^7, R^8, and R^9 are hydrogen atoms or a hydrocarbon group, and R^1^0 represents a hydrocarbon group), in which (a) and (b) are preliminarily set at a (M+Mg)/Cr molar ratio of 0.
．． A method for polymerizing olefins, characterized in that contact is carried out in the range of 1 to 10, and used for polymerization. (2) In the organomagnesium complex compound of (b), M
The method for polymerizing olefins according to claim 1, wherein is zinc or lithium. (3) In the organomagnesium complex compound of (b), X
, Y is a group selected from OR^4, OSiR^5R^6R^7, the method for polymerizing olefins according to claim (1) or (2).