DE1942734B2 - Process for the polymerization of alpha-olefins - Google Patents

Description

It is known that a-olefins and their Can polymerize mixtures according to the Ziegler low-pressure process. They are used as catalysts Compounds of the elements of IV. To VI. Subgroup of the periodic table in a mixture

as with organometallic compounds of the elements the I. to III. Group of the periodic table and generally works in suspension, in solution or also in the gas phase.

There are also known methods in which the

3 "catalyst components in conjunction with a inorganic solid can be used.

In Belgian patent specification 650 679 and French patent specification 1,448,320, hydroxychlorides are used divalent metals of the general formula MeOHCl with transition metal compounds to form Ziegler catalysts implemented. However, high polymerization yields per gram of catalyst are only achieved if pressures of 20 atmospheres are used. British Patent 1,140,649 discloses liquid halogen compounds of transition metals with oxygen-containing compounds of divalent metals that are practically free of hydroxyl groups, converted into catalysts for the polymerization of olefins.

Oxides, sulfates, nitrates, phosphates, Called silicates, mono- and polycarboxylates of magnesium and calcium.

The catalyst yields obtained with the claimed catalysts are in spite of the high polymerization pressures low.

It has also been proposed catalysts comprising a titanium halide compound such as TiCl _4, TiBr _4, Ti (OC ₂ H ₅₎ Cl _3, Ti (OC ₂ H _{5) 2} Cl _2, or Ti (OC ₄ Hg) ₂ CI ₂ in a carrier material made of "coordination" products of dihalog'-mids of divalent metals, e.g. B. MgCl ₂ with a 1 cktron donor from the group of aromatic or aliphatic carboxylic acids and their alkyl esters, the aliphatic

or cyclic ethers, the aliphatic or aromatic ketones, the aliphatic aldehydes, the aliphatic or aromatic alcohols, the aliphatic acid halides, the aliphatic aromatic Nitriles, the aliphatic or aromatic amines or the aliphatic or aromatic To use phosphines for the polymerization of olefins, as an activator component of the catalyst organoaluminum compounds of the general

common formula R ₈ A] ₁ R ₈ AlX, RAlX ₈ , R ₁₁ AlOR ₁ RAI (OR) X and R _{8 AlX 8} , where R is an alkyl or aryl group and X is a halogen atom, or dialkyl zinc can be used.

In technology, polymerizations based on the Ziegler process are of particular interest when Pressures below lOatü high catalyst yields can be achieved so that further processing of the polymers is possible without removing the catalyst. The catalysts remaining in the polymer must not cause discoloration of the polymer, nor must corrosion appear the processing machines.

A process has now been found for the homo- and copolymerization of -olefins of the general formula R - CH = CH ₈ , in which R is hydrogen or a hydrocarbon radical, preferably a straight-chain or branched, substituted or unsubstituted alkyl radical having 1 to 10 carbon atoms, in solution, in suspension or in the gas phase at temperatures of 20 to 200 ⁰ C, preferably 50 to 150 ° C, bu pressing at up to 50, preferably 1.5 atm to 20, in the presence of a mixed catalyst consisting of the reaction product of a titanium compound with a magnesium compound (component A) and an organoaluminum compound (component B), optionally with regulation of the molecular weight by hydrogen, which is characterized in that the polymerization is carried out either in the presence of a mixed catalyst, component A of which is carried out by reacting a tetravalent halogen-containing titanium compound Formula TiX _n (OR) ₄ - ,,, wherein ;; = 1 to 4, X = chlorine or bromine and R denotes identical or different hydrocarbon radicals with 1 to 18 carbon atoms, with crystal alcohol-containing magnesium halides of the formula MgX ₂ · «ROH, where X = Cl, Br, I, η = 0.1 to 6 and ROH denotes a mono- or polyhydric primary, secondary or tertiary alcohol with 1 to 20 carbon atoms, was prepared and aluminum dialkyl hydrides of the formula AlR ₂ H, where R denotes identical or different hydrocarbon radicals with 1 to 16 carbon atoms, are used as component B thereof, or in the presence of a mixed catalyst, the component A of which is obtained by converting Ti (OC ₁ Hj) ₈ Cl, Ti (OC ₃ H ₇ ) ₃ Cl, Ti (OC ₃ H ₇ ) ₂ Cl ₂ , Ti (OiC ₃ HO ₃ Cl, Ti (OiC ₃ H ₇ ) ₂ Cl ₂ , Ti (OiC ₃ H ₇ ) Cl ₃ , Ti (OiC ₄ Hn) ₃ Cl, Ti (OiC ₄ Hg) ₂ Cl ₂ with crystalline alcohol-containing magnesium halides of the above formula and as its Component B aluminum trialkyls of the formula AlR ₃ , where R are identical or different carbon atoms hydrogen radicals with 1 to 16 carbon atoms can be used.

For the person skilled in the art it was surprising and by no means foreseeable that the reaction products mentioned of crystal alcohol-containing magnesium halides with chlorine-containing titanium compounds resulted in particularly active catalysts. Because in the aforementioned Belgian patent specification 650 679 it is expressly emphasized that no active catalysts can be obtained when using other divalent hydroxyl- or chlorine-containing metal compounds than MeOHCl.

The reaction products of chlorine-containing tetravalent titanium compounds also turn out to be Magnesium halides containing water of crystallization - such as

MgCl ₈ -H ₈ O, MgCl ₈ · 4Η ,, 0 or MgCl ₈ -6H ₈ O -

in the polymerization of -olefins according to the

Zi'egler process only as very mediocre catalysts. The same also applies to the conversion products

s of anhydrous magnesium chlorides with chlorine-containing titanium compounds, which are also only bad Catalyst yields result.

The inventive method used as Component A is a titanium-containing reaction product,

ίο which was produced by the action of a tetravalent halogen-containing titanium compound on crystalline alcohol-containing magnesium halide. Tetravalent halogen-containing titanium compounds of the general formula TiX »(OR) ₄ -», in which π = 1 to 4, X = chlorine or bromine and R identical or different carbon> vD «.- yrstaffreste, in particular straight-chain or branched alkyl radicals with 1 to 18, preferably 1 to 10 carbon atoms.

Sometimes it can be advantageous to prepare the halogen ortho-titanic acid esters of the _{above general formula in situ by reacting the respective ortho-titanic acid ester with TiCl 4 or TiBr 4} in the appropriate proportion.

Temperatures of 0 to 200 ° C. are recommended for the reaction, the upper temperature limit being the given by the decomposition temperature of the respective tetravalent, halogen-containing titanium compound will. Temperatures from 0 to 120 ° C. are advantageous.

The reaction is expediently carried out in inert diluents. As such, the at Ziegler low pressure process common aliphatic or cycloaliphatic hydrocarbons such as butane, Pentane, hexane, heptane, cyclohexane, methylcyclohexane, and aromatic hydrocarbons such as Benzene, xylene; also hydrogenated diesel oil fractions, which are carefully removed from oxygen, sulfur compounds and

> i ° moisture has been freed are usable.

In many cases it is advantageous to carry out the reaction of the halogen-containing titanium compound with the crystal alcohol-containing magnesium compound in different temperature ranges.

So you can use the tetravalent, chlorine-containing titanium compound on the crystal alcohol-containing magnesium chloride, for example, first at temperatures from 0 to 30 ° C can be added dropwise with stirring and then the reaction at Temperaturen from 60 to 120 ° C with stirring.

The hydrocarbon-insoluble reaction product of the halogen-containing tetravalent titanium compound with the crystal alcohol-containing magnesium chloride is freed from titanium compounds that are not fixed on the solid by repeated washing with one of the above inert diluents, in which the titanium (IV) compound used dissolves easily.

To produce component A, critical

Stable alcohol-containing magnesium halides of the general formula MgX ₂ · «ROH used, in which X = Cl, Br, I, π = 0.1 to 6, preferably 0.5 to 4 and ROH is a monohydric or polyhydric primary, secondary or tertiary alcohol 1 to 20 Koh carbon atoms, preferably 1 to 10 carbon atoms. The use of MgCl ₂ in connection with monohydric aliphatic alcohols with 1 to 10 carbon

Atoms, such as methanol, ethanol, isopropanol, penta-merization with an aluminum organic compound

nol, octanol, <Ju ⁿ ? at temperatures from -30 to 15O ⁰ C, preferably

The representation of the crystalline alcohol-containing magnesia 0 to 40 ⁰ C and then treated

siumbalogenide takes place according to known methods in the polymerization. When using

methods. ⁵ dung of chlorine-containing organoaluminum compounds

So you can make anhydrous Magnesiumhalogentd bonds, however, it is useful to the obtained

to wash with alcohols in a molar ratio of 1: 0.1 to 1: 6 um reaction product. Then success *

set. The crystal alcohol containing Magnesiurahalo activation with organoaluminum compounds

is halide "nschließend in a ball mill decomposed at temperatures of 20 to 200 ⁰ C, preferably

grind. But it is also possible, the magnesium io 50 to 150 ⁰ C,

halide with a large excess of alcohol to- Furthermore, component A can also be used

and add the alcohol, which is not crystallized in the polymerization with an organoaluminum

alcohol is bound, then under reducing compound and a small amount of a polymer

temp pressure to be determined. convertible olefins at temperatures from -30 to 150 ° C

Furthermore, to display the crystal 15 offset. This creates a catalyst

alcohol-containing magnesium halides also contain magnesia some polymer. In some cases it will

sium alcoholates with hydrogen halides in counterpart - thus grain size, bulk density and grain size -

wait for alcohols to be converted; z. B. distribution of the polymer powder favorably influenced.

Mg (OR), + 2HX = MgX ₂ · 2ROH (X = Cl, FRY) ^As Komponente_B be AluminiumtrialkyleAlR,

^OK '■ ^{6 2} ao or Aluminiumdialkylhydn; t of the formula AlR ₂ H

The reaction can also be used in hydrocarbons, in which R the same or different carbon

Alcohol mixtures are carried out. Alcohol, lenwasserstoffreste, preferably alkyl radicals with 1 to

which is not bound as crystal alcohol is 16, preferably 2 to 6 carbon atoms

Eating again under reduced pressure - like AI (C ₂ H ₅ ) ₃ , A1 (C ₂ H ₅ ) ₂ H, Al (C ₃ H ₇ ) ₃ , A1 (C ₃ H ₇ ) ₂ H,

distilled. »5 AI ^ iC ₄ II _S ) ₂ H.

The representation of the crystalline alcohol-containing magne- The organoaluminum component can be found in

Finally, lium halide can also be obtained by an Um concentration of 0.5 to 10 mmol, preferably

Settlement of magnesium with alcohol-halogenated water- 2 to 8 mmol per liter of dispersant, or per

Mixing of substances takes place: liters of reactor volume are used.

J.QU 30 The polymerization takes place in solution, in suspension

Mg + 2HX > MgX ₂ · «ROH + H ₂ ^{or in the} gas phase, continuously or discontinuously

(v _ pi _Rr π nuierlich at temperatures from 20 to 200 ⁰ C, carried out before (Λ - ui, ßr "Jj preferably 50 to 150 ⁰ C. The pressures be alcohol, which is not bound as crystal alcohol, carry up to 50 atm, preferably 1.5 to 20 at.
is, then under reduced pressure 35, specifically the polymerization in suspension or in is distilled off. the gas phase is expediently at pressures

Before the reaction with the titanium compound can be carried out from 1.5 to 10 atm. Per liter of dispersing

the magnesium halide containing crystalline alcohol is used with medium or per liter reactor volume

other inert, polymerization non-inhibiting, in this case 0.005 to 1 mmol, preferably 0.05

inorganic compounds are mixed. As 40 to 0.5 mmol, titanium compound,

such are hydroxides, sulfates, oxides, carbo- The polymerization in solution, which is preferably used for

nate, phosphates and alcoholates of metals z. B. Production of low molecular weight polyolefins (poly

Mg (OH) ₂ , alkaline earth phosphates, Mg (OR) ₂ and BaO. olefin waxes) with »jsp / c values of 0.1 to 0.4 (

The molar ratio between the measure according to the invention as a ι% solution in decahydronaphthalene

used crystal alcohol-containing magnesium halide 43 135 ° C) is carried out, expediently

nid and the inorganic compound is not at temperatures of 120 to 200 ° C and at a

critical and can fluctuate within wide limits. Pressure up to 50 atmospheres, preferably 1.5 to 20 atmospheres. For

Recommended is? In the range 1: 0.05 to 1: 0.9, the solution polymerization becomes the titanium compound

preferably 1: 0.08 Ns 1: 0.5. at a concentration of 0.05 to 1.5 mmol per

The titanium content of component A can be used in the range of; .o liters of solvent.

from 0.005 to 0.5, preferably 0.01 to 0.3 mmol per For solution or suspension polymerization

Grams of component A. It can be made suitable for the Ziegler low pressure process

Reaction time, the reaction temperature and the usual inert diluents such as them

Concentration of the tetravalent, halogen- already used earlier in the manufacture of the compo-

containing titanium compound. 55 nente A have been described in more detail.

For the polymerization is carried out on the magnesium As Moramers can olefins of the general

Compound-fixed titanium component expediently formula P. - CH = CH ₂ can be used, in which R

in the concentration range from 0.005 to 1.5, hydrogen or a hydrocarbon, especially

preferably 0.05 to 1.5 mmol per liter of dispersant a straight-chain or branched, substituted

medium or reactor volume used. In principle 60 tuated or unsubstituted Al ': yl radical with 1 to 10,

but higher concentrations are also possible. preferably 1 to 8 carbon atoms.

The conversion of the tetravalent titanium compound, for example, are ethylene, propylene, butene- (l),

in component A in the polymerization-active, pentene (l), 4-methylpentene (l), octene (l) called,

lower valency stage is expediently It is also possible to use mixtures of the olefins of the above formulas

are used during the polymerization by the aluminum 65 mel, especially those that are up to

organic compound (component B) at tempe- 30 percent by weight, preferably up to 10 percent by weight

Temperatures from 20 to 20 ° C, preferably 50 to 150 ° C. percent, one or more comonomers contain.

However, component A can also be used before the poly- Preferably ethylene or mixtures of

Ethylene with up to 10 percent by weight, preferably up to 5 percent by weight, of -olefins of the above Polymerized formula.

The molecular weights of the polymers can be regulated in a known manner, preferably using Used hydrogen.

Polymerization is used for the production of polyolefins for extrusion and injection molding carried out with hydrogen contents in the gas phase of up to 80 percent by volume.

For the preparation of low molecular weight polyolefins (waxes), on the other hand, polymerization is used with hydrogen contents in the gas phase of 80 to 100 percent by volume.

The great technical progress compared to the known processes results in the simpler one Execution of the polymerization, as already due to the high activity of the catalysts according to the invention very high catalyst yields can be achieved at pressures below 10 at.

With the aid of the catalysts of the invention, the interest to the extrusion or injection molding sector polyolefins blank with ^ sp / c values from 0.8 to 6 (as measured in 0.1% Dekahydronaphthalinlösung at 135 ⁰ C) representing in such a high yield, that the catalyst can remain completely in the polymer.

With the aid of the process according to the invention, very simple polymerization processes can be carried out even at pressures below 10 atm carry out, since such complex operations as catalyst decomposition and catalyst removal are omitted in the suspension polymerization. After filtering off the dispersant, the polyolefin is dried and processed further directly. the extremely small amounts of catalyst that remain in the polymer do not cause discoloration the polymers nor corrosion damage to the processing machines.

The use of the catalysts of the invention also offers the great advantage that at polymerisation in suspension or in solution with a hydrogen content of more than 80 percent by volume in the gas phase polymers with 7? spec / c values of 0.1 to 0.4 (measured in 1% solution in Decahydronaphthalene at 135 ° C) arise in high yield.

Such low molecular weight polyolefins are becoming increasingly technical as so-called build-up waxes Interest. During suspension or solution polymerization, up to 1000 g build-up wax. According to the known methods (see Belgian patents 638 007 and 641 563 and French patent 1,500,046) build-up waxes arise as a result of the lower activity of the Catalysts only in moderate yield.

example 1
I. Catalyst manufacture

a) Representation of magnesium chloride containing crystalline alcohol

In a suspension of 57 g (0.5 mol) of Mg (OC ₂ H _{5) 2} in 500 ml of ethanol (abs.) Are at 2O ⁰ C with stirring 43.8 g (1,2MoI) HCl initiated. The alcohol is subsequently distilled off at 200 Torr and a maximum bath temperature of 120 ⁰ C. 102 g of magnesium chloride containing crystalline alcohol are obtained which, based on the analytical data, has the formula

MgCl, • 2.4 C ₂ H ₅ OH
S owns.

The magnesium chloride containing crystalline alcohol is dried in a ball mill with the exclusion of moisture ground.

ίο b) 50 g of the above crystal-containing alcohol magnesium chloride under nitrogen overlay with 1000 ml of a lmolaren TiCl ₂ (OiC ₈ H ₇ V solution in cyclohexane was added and overall 2 hours at 30 ⁰ C and then for 8 hours at 7O ⁰ C.

IS stirs. Washing the precipitate by decantation, and stirred at 50 ⁰ C 8 times with 800 ml of a hydrogenated diesel oil fraction (boiling range 130 to 150 ⁰ C). The volume of the suspension is made up to 1000 ml.

1 ml of suspension contains 0.075 mmol of titanium compound.

II. Polymerization of ethylene

In a 200-liter Pfaudler kettle, 1001

»5 submitted diesel oil with a boiling range of 140 to 200 ⁰ C, heated the boiler contents to 85 ° C and displaced the air by flushing with pure nitrogen and hydrogen. A solution of 54 g (400 mmol) of Al (C ₂ Hs) ₃ in 500 ml of diesel oil and 100 ml of the catalyst suspension shown in Ib (4.0 mmol of titanium compound) is then added.

The polymerization is carried out at 85 ° C. It 5 kg of ethylene per hour and so much hydrogen are introduced that the hydrogen content in the gas phase 35 percent by volume. The pressure rises to about 6 atm in the course of the polymerization. To Hours, the resulting polyethylene is separated from the dispersant by filtration and dried.

There are 38 kg of polyethylene with a τ / spec / c value = 2.0 (measured in 0.1% decahydronaphthalene solution at 135 ° C.).

Example 2
♦ 5 I. Catalyst manufacture

a) 90 g crystal alcoholic magnesium chloride are dissolved in 600 ml of a diesel oil fraction (boiling range 130 to 15O suspended ⁰ C).

To this suspension is added dropwise within one hour at 40 ⁰ C with stirring under a nitrogen blanket 275 g (1,5MoI) TiCl _4. ^{The suspension is then stirred at 100 °} C. for 6 hours under a nitrogen blanket. The precipitate is washed by decanting and stirring at 6O ⁰ C 8 times with 500 ml of the hydrogenated diesel oil fraction each time. The volume of the suspension is made up to 800 ml.
1 ml of suspension contains 0.04 mmol of titanium compound.

b) A1 (C ₂ H ₅ ) ₂ C1 treatment

To 150 ml (6 mmol of titanium compound) of the above suspension are added within 60 minutes with stirring and nitrogen blanketing 6.0 j (50 mmol) of aluminum diethyl chloride in 50 m Diesel oil was added dropwise at 25 ° C. The suspension was then stirred at 25 ° C. for 2 hours

409 549/37

Washed 4 times with 150 ml of diesel oil each time. The volume is made up to 200 μl.

II. Ethylene-butene (1) copolymerization

In a 200-liter Pfaudler kettle, 1001 Diesel oil with a boiling range of 140 to 200 "C is present, the boiler contents are heated to 85 ° C and the Air displaced by purging with pure nitrogen.

Then a solution of 57 g (400 mmol) of aluminum diisobutyl hydride in 500 nil of diesel oil and 150 ml of the finished catalyst suspension (4.5 mmol of titanium compound) were added.

At 85 ° C, 42 kg of ethylene (6 kg / h) and 0.49 kg of butene- (l) (0.07 kg / h) and so much are produced in 7 hours Hydrogen introduced so that the hydrogen content in the gas phase is 25 percent by volume.

The boiler pressure rises to 5 atm in the course of the polymerization.

The ethylene-butene copolymer is filtered through separated from dispersant and dried.

40 kg of polymer with a / yspec / c value of 3.9 (measured in 0.1% strength decahydronaphthalene solution at 135 ° C.) and a density of 0.948 g cm ^-3 are obtained.

ίο The contact yield is 8.8 kg of polymer per mmol of titanium compound. 7 kg of polymer are formed per gram of MgCl ₂ used for the production of the catalyst. The MgCl, content in the polymer is <0.02 percent by weight. The polymer is very suitable for extrusion processing for the production of bottles, cables and pipes

Claims (7)

Patent claims: 1. Process for the homo- and copolymerization of -olefins of the general formula R-CH = CH ₂ in which R denotes hydrogen or a hydrocarbon radical, preferably a straight-chain or branched, substituted or unsubstituted alkyl radical with 1 to 10 carbon atoms, in solution, in suspension or in the gas phase, at temperatures of 20 to 200 ^° C., preferably 50 to 150 ^° C. , at pressures up to 50 at, preferably 1.5 to 20 at, in the presence of a mixed Jcatalyst, consisting of the reaction product of a titanium compound with a magnesium compound (component A) and an aiuminiumorganischen compound (component B), possibly with regulation of the molecular weight by hydrogen, characterized in that the polymerization is carried out either in the presence of a mixed catalyst whose component A is obtained by reacting a tetravalent halogen-containing titanium compound of the formula TiX _n (OR) ₄ -H, in which /; - 1 to 4, X = chlorine or bromine and R are identical or different hydrocarbon radicals with 1 to 18 carbon atoms, with crystal alcohol-containing magnesium halides of the formula MgX ₂ · «ROH, in which X = Cl, Br, I, /; = 0.1 to 6 and ROH denotes a mono- or polyhydric primary, secondary or tertiary alcohol with 1 to 20 carbon atoms, and as its component B aluminum dialkyl hydrides of the formula AlR ₂ H, where R is identical or different hydrocarbon radicals with 1 to 16 Means carbon atoms, are used, or in the presence of a mixed catalyst, component A thereof by reaction of Ti (OC ₂ H ₅ ) ₃ Cl, Ti (OC ₃ H ₇ ) ₃ Cl,
Ti (OC ₃ H ₇ ) ₂ C1 ₂ , Ti (OiC ₃ H ₇ ) ₃ C1.
Ti (OiC ₃ H ₇ ) ₂ C1 ₂ . Ti (OiC ₃ H ₇ ) CI ₃ ,
Ti (OiC ₄ H _O ) ₃ C1, Ti (OiC ₄ H ₉ ) ₂ CI ₂ with crystalline alcohol-containing magnesium halides of the above formula and as its component B aluminum trialkyls of the formula AlR ₃ , where R denotes identical or different hydrocarbon radicals with 1 to 16 carbon atoms, are used. 2. The method according to claim 1, characterized in that crystal alcohol-containing magnesium chlorides of the formula MgCl ₂ · «ROH, in which η = 0.1 to 6 and ROH is an aliphatic alcohol with 1 to 10 carbon atoms, is used. 3. The method according to claim 1, characterized in that aluminum trialkyls of the formula Al (R) ₃ or aluminum dialkyl hydrides of the formula Al (R) ₂ H are used, R being identical or different hydrocarbon radicals having 2 to 6 carbon atoms. 4. The method according to claim 1, characterized in that mixtures of ethylene polymerized with up to 30 percent by weight of -olefins of the formula mentioned. 5. The method according to claim 1, characterized draws that ethylene, propylene, butene- (l), Polymerized pentene (l) or 4-methylpentene (l). 6. The method according to claim 1, characterized in that the crystal alcohol-containing Magnesium halide with other inert ones, the Polymerization non-inhibiting, inorganic compounds in a molar ratio of 1: 0.05 mixes up to 1: 0.9, 7. The method according to claim 1, characterized in that component A of the catalyst is mixed with an organoaluminum compound and a small amount of a polymerizable olefin at a temperature of -30 to 150 ^° C. before the polymerization.