DE1962732C - Process for the polymerization of ethylene - Google Patents

Description

ι 2

As catalysts for polymerisation or copolyethylene polymer it has a density of at least

merization of olefins such as ethylene are at least 0.965, an excellent crystallinity and a

called Ziegler catalysts, used the two-narrow molecular weight distribution, It is true from the component catalysts are. However, British patents 822 611 and 869 370 can be

hardly say that even in the case of using an S knows ethylene in the gas phase in the presence of

typical Ziegler catalyst, d. H. one of titanium catalysts to polymerize by applying halides and an alkyl aluminum compound of UbergaugsmetaUverbindungen and organometallic

derived catalyst, the olefin poly compounds obtained on previously produced polyethylene

merisate necessarily satisfactory self-received. In the cited publications

own stocks. The Ätbylenpolymerisate, which under io is not said that the manner of the

Using such catalysts, bringing together the transition metal compound

namely have a density of 0.95 to 0.96 and one and the organometallic compound with that before

broad molecular weight distribution. manufactured polyethylene with a view to the later

It is known that these disadvantages are eliminated, and polymerization is of particular importance

can, if you use catalysts made of vanadium 15 are also catalysts made of vanadium compounds

compounds in combination with alkyl aluminum fertilizers of the above formula VOY ₈ and organic

compounds used When polymerizing aluminum compounds of the above formula

of ethylene using such catalysts AlR, - _n Xn not mentioned. Anyway, could be due to

is carried out, it will not be foreseen in the presence of an inert of these documents that

Hydrocarbon solvents have an extremely good effect on this particular catalyst system

Notable polymerization activity developed compounds of the formula VOY, and compounds

and an ethylene polymer of more uniformly the formula AlR ^ _n X _{n is} then and only advantageous

Preserve molecular weight distribution. However, the results with regard to the catalyst life Catalyst life is short, and the polymerization time is achieved (cf. the

Reakticn progresses so quickly that a control as equal attempts B), if one has two separate parts

the reaction temperature is difficult. In addition to pre-made polyethylene individually with the

if such catalysts are used, both catalyst components are impregnated,

holding ethylene polymer in very finely divided examples of usable alkyl aluminum compounds

Foim before, and it possesses an extremely low debris fertilization of the general formula AlR _s _ _n Xn are:

Weight. Therefore, these catalysts are for the 30 trialkylaluminum compounds, dialkylaluminum

large-scale use not advantageous. monohalides, sesquialkyl aluminum halides,

The invention now relates to a process for monoalkylaluminum dihalides, dialkylalumintum- Production of ethylene, optionally in a mixture of monoalkoxides and mono- (trialkylsiloxy) -dialkylalu-

with other copolymerizable olefins in minium compounds. As halogen, they contain in

an amount of up to 10 percent by weight, with a 35 usually chlorine, bromine or iodine.

Temperature from 0 to HO ⁰ C under normal pressure or as a vanadium compound of the general formula

elevated pressure in the presence of catalysts from VOY ₃ is necessarily a compound of

A. Organoaluminum compounds of the general pentavalent vanadium used, which is also derived from the Formula can be seen above general formula. How after-

_A IR χ 4o is described in detail below, these are

³ ~ "" Vanadium compounds used to make an inert

where R is an alkyl group to be impregnated with the symmetry ethylene polymer. It will

bole X, which are identical or different from one another and therefore preferably use vanadium compounds,

can be, for a halogen atom, an alkoxy- $ ^β "J. Hydrocarbons lewit are soluble. Da

group or a trialkylsiloxy group stand ^4S vanadium compounds only _u less than pentavalent

andIn denotes a number from 0 to 2, and vanadium is poorly soluble in hydrocarbon

solvents are, it is impossible to be an inert one

B. vanadium compounds of the general formula ethylene polymer thus sufficient to impregnate YQY ren. It would therefore be difficult to fully understand the reaction.

³ so constantly to be carried out.

in which the symbols Y, which can be identical or mutually exclusive, vanadium compounds of the above alone can be different, for a halogenated formula are, for example, trialkoxyvanagen atom. an alkoxy or a trialkylsiloxy d _y i _e such as trimethoxyvanadyl, triethoxyvanadyl, tri group, where at least one Y is a propoxyvanadyl, tributoxyvanadyl and triisobutoxy alkoxy group or a trialkylsiloxy group ₅₅ vanadyl; Halogeflalkoxyvanadyl such as Monochlor is, diethoxyvanadyl, Dichlormonoäthoxyvanadyl, Mono * which is characterized in that the polymerization cblordipentoxyvanadyl, Monochlorodibutoxyvanadyl in the gas phase in the absence of liquid carbon and Monochlorodiisobutoxyvanadyl; and tri- (trialkylhydrogen as a diluent in the presence of siloxy) * vanadyls such as tri * (trimethylsiloxy) -vanadyl and a two-component catalyst carried out 60 tri- (triäthylsiloxy) -vanadyl. Of these compounds, which has been prepared in that two trialkoxyvanadyls and haloalkoxyvanadyls separate portions of a finely granulated ethylene poly * are preferably used,

merisats separated with the two catalyst components. According to the method of the invention, the

components A and B have been impregnated. Catalyst components separated on finely granulated

In this way, a very large extension of the ethylene polymer is absorbed in order to

the catalyst life achieved, It is thereby to produce sator. Any ethylene

In addition, a polymer in granulate form with polymer can be used, since «no contaminants

get a high bulk density. The obtained contains compounds that can act as catalyst poisons.

3 4

th. Taking into account the fact that the temperature above this range by-too-catalyst components must be absorbed, since the ethylene polymer obtained is then, however, a porous, finely divided ethylene polymer adhering to one another or to the reaction vessel wall preferred. An ethylene polymer is expedient. The polymerization reaction can take place under Norraalmit a particle size corresponding to a clear 5. pressure or at increased pressure, preferably below Screen mesh size of 0.074 to 2.00 mm and a pressure of at least 10 atmospheres Bulk density of 0.1 to 0.3 g / ml used. will.

Since the catalyst components are moist- According to the method of the invention, wateriness, Oxygen, etc. are easily deactivated if there is any substance in the reaction system to prevent the the finely granulated ethylene polymer used for abio molecular weight or other properties of the absorption the catalyst components is used to control or to hold polymerizats be adequately dried. steer.

For the absorption of the catalyst components on the polymerization of ethylene is in the above

The finely granulated ethylene polymer can be carried out in any of the ways described. Because the catalyst desired method can be used. It is with moisture, oxygen, and the like, as it was before For example, possible direct absorption to be described above, is easily deactivated, should that act, which depends on the type of catalyst components, ethylene, hydrogen and the other components. A component that is generally applicable for this purpose and that is added to the polymerization system The method consists, for example, in that they are sufficiently purified before the reaction Catalyst components will have been dissolved in or out.

be thinned with a hydrocarbon solution The obtained according to the method of the invention

Medium with a low boiling point, such as pentane, ethylene polymer is colorless and has a high and on the finely divided ethylene polymer from bulk weight. It is therefore for use in the are sorbed and the hydrocarbon solution production of moldings is suitable. The Verwenmitul is evaporated from the ethylene polymer. Introduction of the produced in the manner indicated Another method is that the catalyst allows the production of more than catalyst component as a gas with an inert gas diluted 4000 g of polymer per gram of the vanadium compound the finely dispersed oil / oil polymer passes through the downdraft. It is thus possible to adjust the level of removal of the in order to eliminate the need for a separation of the gas or vapor of the catalyst, on effect. The AU? the finely granulated 30 According to the method of the invention, a Ethylene polymer to be absorbed amount of polyethylene with excellent crystallinity and Catalyst components can have a large, uniform molecular weight distribution in the granu range vary. In general, the range of high bulk density lated forms obtained is within 0.01 to 10 mmoles per gram of the ethylene den. Because the use of the catalyst used Polymer. 35 brings a high degree of efficiency, the

The ratio of the catalyst components to the amount of catalyst compared to known processes each other fluctuates depending on the reaction to be reduced. An additional benefit will be the conditions. However, a ratio of half is preferably achieved in that the removal of the 0.1 to 100, and very preferably from 1 to 50, based on the catalyst from the polymer obtained, otherwise on Al / V (atomic ratio). 40 necessary treatment is not required. If the

No particular limitation is necessary for the polymerization of ethylene according to the method with regard to the preparation of the catalyst from which the invention is carried out may be more gaseous finely granulated ethylene polymers that are effectively used separately to generate the hydrogen have been impregnated with the catalyst components to control the molecular weight of the polymer obtained. The separated with the catalyst components 45 ern. It was found that the formation of wax impregnated finely granulated ethylene polymers like polymers of low molecular weight low can be dissolved before being added to the reaction system. The mixed in according to the method of the invention will. They can also be put separately in the catalyst has a longer life than Reaction system are given. Also other grains - the previously known catalyst systems. Besides that components may exist in the reaction system. 50 there is no risk of the polymerization

The polymerization of the ethylene will proceed too quickly with reaction. Using a carried out application of the catalyst obtained in this way. inert liquid hydrocarbon is accordingly According to the method of the invention, it is also possibly not necessary and not provided. Deshail borrowed, copolymerization of ethylene with others enables the process of the invention to do a great deal Olefins, such as ethylene, propylene or butene-1, in a technically advantageous polymerization of ethylene. Perform an amount of up to 10 percent by weight.

The polymerization reaction is thereby carried out by- Example 1

led that ethylene or a mixture of ethylene

with other olefins in the stated amount in the powdered polyethylene, which is polymerized according to a conventional gas phase. A fluidized bed or a stirred tank can be used as the reaction vessel. and of any catalysis still present. The use of a fluidized bed is preferred, however, when it had been freed, it was sieved so that the heat generated in the polymerization reaction fractions can easily be removed from it in accordance with a clear sieve mesh. Get the width of less than 1.19mm. De polymerization reaction is advantageously carried out at a 65 bulk density of this polyethylene was 0.1 g / m temperature between room temperature and 110 ⁰ C, The powdery polyethylene was overnight b preferably between 50 and It) O ⁰ C, carried out at a temperature of 6O ⁰ C dried. It is not advisable to carry out the polymerization at a dry powdery polyethylene in d

Atmosphere of inert gas separated with a solution of triisobutoxyvanadyl

VO (0-iso-C ₄ H _e ) _a

in pentane and a solution of diethylaluminum monochloride _{A1 (} c ₈ H _{s) i} Cl

impregnated in pentane. After impregnation, the two impregnated preparations of powdered polyethylene were treated with a stream of an inert gas to drive off the pentane. Thus, a powdery polyethylene preparation containing the vanadium compound and another powdery polyethylene preparation containing the alkylaluminum compound were obtained.
An anchor-shaped stirrer was placed in a 500 ml

Ulasautoklav used in such a way that the impeller on scratch the inside wall of the autoclave. Purified nitrogen was put into this autoclave initiated in order to expel the air that was present in the interior of the autoclave. Particular Quantities of the catalyst ingredients prepared as above were added to the autoclave. then was a mixture of gaseous ethylene with a certain amount of hydrogen under pressure and

ίο gentle stirring initiated. During the polymerization reaction gaseous ethylene was also introduced when the pressure in the autoclave decreased while the reaction pressure was kept at a certain value. The polymerization reaction was carried out in this way for 1 hour. The results obtained are in the Table I compiled.

Table I.

attempt

Vanadium component

VO (O-iso-Bu),
mmol

Carrier polymer g

Aluminum component

AlAt ₁ Cl mmol

Carrier polymer
G

Al / V

Atomic ratio

Polymerisation

satioDS-

temperature

"C

Polymerization pressure
kg / cm «

H ^ C ₁ H ₄

Molar ratio

0.1

0.05

0.03

2.5
1.0
0.5

4.0 2.0 2.0

2.5 2.5 2.0

40
40
67

40 ± 3
40 ± 3
36 ± 2

0.15
0.22
0.13

Ver
search Amount of comp
deten polymers
G Debris weight of the
Polymers
g / ml Melt index des
Polymers Catalyst efficiency
g polymer /
g VO (O-iso-Bu), Polymerization speed
longevity g polymer /
GMO (O-iso-BuVStd.
Partial pressure of ethylene
(atm) 1
2
3 20th
24
11.6 0.28
0.28
0.24 3.2
0.9
0.3 700
1600
1500 200
320
280

Annotation:

The symbols »iso-Bu« and »Eti in the table stand for the isobutyl and ethyl group, respectively.

An X-ray analysis of the polyethylene product obtained was found to have a crystallinity of owned at least 90%.

Example 2

The gas phase polymerization of ethylene was carried out as described in Example 1 with the modification that the vanadium component and aluminum component used there have been replaced by those which are mentioned in Table II below. The results obtained are shown in Table II.

Table II

Ver Vanadium component crowd carrier Amount of
educated
Polymers Aluminiurikoi.iponente crowd carrier Melt index
of the polymer Al / V Polymerisation
station Catalyst effect
degrees g polymer
V-connection Polymeri
station search Vanadium mmol g poly G aluminum mmol g poly atom tenipcratur pressure connection 0.1 ethylene 7.6 connection 2.0 ethylene 0.2 ratio "C kg / cm ' 1 VO (O-ISO-Bu) ₃ 0.1 2.0 5.4 AlAtCl, 2.0 2.0 0.9 20th 50 5 VO (O-JSO-Bu) ₃ 0.1 2.0 25.6 AlAtCl, 2.0 2.0 0.3 20th 50 5 2 VOCl (OAt) ₂
VO (OAt), 0.1 2.0 AlÄtjCl 2.0 2.0 20th 80 5 3 VO (OSiMe,), 0.05 2.0 23.7 AlAt ₁ Cl 2.0 2.0 3.0 20th 80 5 4th 2.0 AlAt ₁ Cl 2.0 40 80 266 5 ■ μη. 187 Polymerization *. Ver.
search Molar ratio Rubble weight
of the polymer 1330 speed
g polymer
gV'connection'hours
Partial pressure of ethylene, 2.0 1420 (atm) 1 3.0 160 2 0.2 150 3 0.16 320 4th g / ml 0.20 0.21 0.34 0.32

Example 3

To manufacture the catalyst components, * the 0.05 HiMoI triisobutoxyvanadyl

VO (Omso * Bu),

or 2 mmol diethylaluminum monochloride separated on each 2 g of polyethylene with a weight of 0.1 g / ml and a Teiiehen size accordingly a clear sieve mesh size of 0.177 to 0.250mm applied, according to a conventional sump ' polymerization had been established.

Under a nitrogen atmosphere, in a 2 liter Autoclave, which was equipped with a stirrer, given these catalyst components. Gin gas mixture of ethylene and hydrogen was taking Stir the catalyst components into the autoclave initiated, and the polymerization was ^{carried out at 40 0} C for 60 minutes. An average ethylene / hydrogen gas composition of 0.36, based on Ht / GjH (molar ratio), S was used. As a result, 33.5 g of uniformly granulated polyethylene having a melt index of 0.35 was obtained. The catalyst efficiency in this reaction was 2340.

'Example 4

The polymerization reaction was carried out as described in Example 3 with the modification that the sizes of the catalyst components and the reaction conditions are as in the following is table IH specified has been changed. The results obtained are summarized in Table ItI « placed.

table

Vamdium component Carrier
Polyethylene Aluminum component carrier
PolyftUtyleo Al / V Polymerisatkms- time pressure HJCiHi ' Ver
luch VO (O-Im-Bu). 8th AlAt ₁ Cl t Atonv Ttmpe-
rature Min. kg / cm * MoI- mmol 2.0 mmol 2.0 • c 75 21 relationship 1 0.02 2.0 2.0 2.0 100 50 100 20th 0.217 2 0.03 2.0 2.0 2.0 67 50 90 10 0.268 3 0.02 2.0 2.0 2.0 100 50 120 10 0.220 4th 0.02 2.0 100 50 0.215

Ver
search yield
on
Polymers
G Catalyst-
tfirkungsgrac average
liche »
Molecular weight
• 10 « Enamel
index") Property
ΑοπΑΏ £ ΐΒκ6ιτ
UwT SHrIIIIICIZ *
viscosity
torn pressure ¹ ) ftendaPo!
Density") lyethylene
Blow.
Afro »*
strength ¹ )
kg-cm / tm * ElastiHttts-
moAil »)
kg / cm 10- * Rubble-
weight of the
Polyethylene
powder
g / ml 1
2
3
4th 39.0
61.0
48.2
63.5 6800
7100
4000
5300 5.3
5.9 5.6
3.3
5.3
5.0 21
21 0.968
0.966
0.966
0.967 181
232 16.4
15.3 0.40
0.39
0.33
0.41

Remarks: ') Ratio of the under 10 * or 10 * dyitfcm * shear forces Enter extruded quantities in a Schmetemdex knife at 190 "C

A value of about 20 in this test means that the mokkutany weight distribution is narrow *) Measured according to ASTM D-1248. *) Measured according to ASTM D-1822. «) Ee according to ASTM D-638. «) Measured according to ASTM D-1238.

The result was that the amount of ptiherfönaigetn polyethylene in the reaction system increased by about 3 g in total increased. The bulk density of the total polyethylene present in the reaction system increased

Example 5

A glass filter was attached to the bottom of a glass tube with an inner diameter of 30 mm and a Length of 20 cm arranged in such a way that it is possible to transfer gaseous ethylene from the bed to the head into the Blow in pipe. Two preparations of 1.5 g each of pulverulent polyethylene were introduced into this fluidized bed, one of which was mixed with 0.2 mmol triisopropoxyvanadyl

VO (O-ISO-C ₁ H ₇ ),

and the other with 0.4 mmoles of diethyl aluminum monochloride

to 0.30 g / ml, while the filled powdery Polyethylene had a bulk density of only 0.21 g / ml.

Example 6

had been impregnated. The production of these impregnated polyethylene was carried out analogously to that described in Example 1. Then became Ethylene was introduced into the tube under normal temperature and pressure, and the polymerization reaction was carried out for 30 minutes. The Er- In the presence of the same catalyst as had been used in Example 3, the gas phase polymerization was carried out under the same conditions, with a gas mixture of 95MoI percent ethylene and 5 mol percent propylene was used. As a result, it became ethylene-propylene Copolymer obtained containing 6 percent by weight propylene. In this reaction the KaUuy was generator efficiency 2100.

Comparative experiments A

Comparative tests were carried out between the method according to the invention and a

209626/35

Claims (5)

10 conventional liquid phase processes using equal amounts of triisobutoxyvanadyl VO (O'iso-C4Ht), diethylaluminum monochloride. In the one comparative experiment, both catalyst components were used in the absorbed state on separate polyethylenes. In the other experiment, both catalyst components were used as a solution in the presence of an inert hydrocarbon as a diluent. The other polymerization conditions were the same in both experiments and the polymerization reaction was carried out using ethylene. The results obtained are shown in Table IV. Table IV Conventional failure method according to the invention inert hydrocarbon for dilution Catalyst VO (O-iso-Bu), AIÄt, Cl Polymerization temperature (0C) Polymerization pressure (kg / cm *) Time to absorb the ethylene (hours) ... Bulk weight of the obtained polyethylene (g / ml) yes added as a solution 90 20 0.08 to 0.15 no absorbed on polyethylene 90 20 1 to 2 0.3 to 0.4 Comparative experiments B Comparative experiments were carried out, the polymerization of ethylene under the The results contained in Table IV show that the catalyst life in the process according to the invention is greater than in the conventional process and that therefore the period of absorption of ethylene according to the procedure is longer. 30 Example 1 described and on the other hand a catalyst was also used the bulk density of the polyethylene obtained according to the Vet- sator, which had been prepared by driving the invention was that the vanadium compound, the alkylaluminum was significantly greater than according to the conventional nium compound and an ethylene polymer ta · procedure. were mixed together. The results obtained are summarized in Table V. Composition of the catalyst VO (OC4H,), (mmol) Al (CJi1) JCl (mmol) .. *. Polymerization temperature ("C) Polymerization pressure Polymerization time (hours) ._. Continuation of the absorption of ethylene .... increase in weight of polymer (g) Adhesion to the wall of the reaction vessel The results compiled in Table V clearly show that if the In contrast, when catalyst components were separately absorbed onto polyethylene according to the method of the present invention, excellent effects on the persistence of the absorption of ethylene and the amount of ethylene formed and that the adhesion to the reaction vessel wall was not observed to the comparative experiment in which the catalyst components were absorbed together on the polyethylene.These facts clearly show that the desired effect can only be achieved if the catalyst components are absorbed separately on the finely divided polyethylene. 1. A process for the polymerization of ethylene, optionally a mixture with other copolymerizable -olefins in an amount of up to 10 percent by weight, at a temperature of 0 bb 110 ⁰ C under normal pressure or elevated pressure in the presence of catalysts A- organoalurainium compounds of the general formula AlR ^ ₁₁ X * where R is an alkyl group, the symbols X, which may be the same or different from one another, represent a halogen atom, an alkoxy group or a trialkylsfloxy 10 a group and η is a number from 0 to 2, and B. Vanadium compounds of the general form VOY ₄ in which the symbols Y, which can be the same or different from one another, for a Halogenatoffl, an alkoxy or a tri-alkylsiloxy group, where at least a Y stands for an alkoxy group or a tri-alkylsiloxy group, characterized in that the gas phase polymerization in the absence of liquid hydrocarbons as a diluent in the presence of a catalyst iwei components is carried out, which has been animal made that two separate parts a finely granulated ethylene polymer separated with the two catalyst components A μ and B have been impregnated. 2. The method according to claim 1, characterized in that catalyst besides are used which were produced by the fact that finely granulated ethylene polymer with a part size corresponding to a clear sieve mesh ' width from 0.074 to 2.00 mm and a rubble weight from 0.1 to 0.4 g / ml separated with the Catalyst components A and B was impregnated. 3. The method according to claim 1 or 2, characterized in that the amount of impregnation tion used catalyst components A and B is 0.01 to lOfflMol per gram of ethylene polymer. 4. The method according to claim 1 to 3, characterized in that the polymerization under use of a catalyst fluidized bed by to be led. 5. The method according to claim 1 to 4, characterized in that the fine granulated ethyte polymer used for the preparation of the catalyst components has a particle size corresponding to a clear mesh size of 0.149 to 2.00 mm and a bulk density of 0.1 to 0.4 g / ml owns 2388