DE1420381B2 - PROCESS FOR THE PRODUCTION OF HIGH MOLECULAR POLYAETHYLENE - Google Patents

Description

The subject of patent 1,019,466 is a process for the production of high molecular weight polyethylenes by polymerizing ethylene with catalyst mixtures made from organoaluminum compounds and compounds of the metals titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, Tungsten, thorium and uranium, which is characterized in that it is obtained from the catalyst mixtures Heavy metal compounds formed by reduction from the other reaction products separates and the separated compounds - optionally after further purification - in any Combination with organometallic compounds of aluminum for the polymerization of ethylene used.

It has now been found that catalysts are particularly advantageous in those for the preparation of the solid Catalyst component titanium (IV) compounds containing organic residues have been used are.

The preparation of the catalysts used for the organic titanium (IV) compounds are dissolved in inert organic solvents or suspended and with organoaluminum compounds to ^{brewing! 0} NEN reduced to black-brown, air-sensitive products.

The Ti contact is activated by adding organoaluminum compounds.

The catalysts used according to the invention can be used to produce ethylenepo of appropriate types particularly well make lymeriisate.

example 1

60

35.5 parts by weight Titandichloriddiacetat are suspended in 400 VolumenteUen a predominantly saturated aliphatic hydrocarbon (bp = 760 202-231 ^0C) and a mixture of ethylaluminum sesquichloride and 38 VoIumentalen 50 parts by volume of the above dispersing agent during the period of 30 minutes with stirring and Stickstoffüberlage-

Example 2

According to Example 1, a contact is made from 63.4 parts by weight of titanium dichloride diacetylacetonate and 50 parts by volume of ethyl aluminum sesquichloride in 600 parts by volume 1,2-dichloroethane obtained. In 100 parts by volume of the slurry in the example 1 The catalyst suspension obtained mentioned in the dispersion medium contains 37.5 mmol of titanium (III> compound.

40 parts by volume of this suspension and a solution of 8.6 parts by weight are used for the polymerization Ethyl aluminum sesquichloride used in 430 parts by volume of the above dispersant and the rest proceed as above. After 5.5 hours, 700 parts by weight of polyethylene are obtained with the specific Viscosity 2.72 and mechanical properties similar to those given in Example 1.

Example 3

A mixture of 32.7 parts by weight of titanium dichloride dibutylate and 50 parts by volume of the in Example 1 mentioned dispersant to a mixture of 30 parts by volume of ethylaluminum sesquichloride and 300 VolumeseUen of the same dispersant added, results in a brown precipitate, which after the usual cleaning is slurried in the dispersant. 250 parts by volume of the suspension contain 4OmMoI titanium (III) compound. The polymerization is carried out as in Example 1, using 100 volumes of contact suspension and 11.8 parts by weight of ethyl aluminum sesquichloride in 590 parts by volume of the cited dispersant. After a test period of six hours, 850 parts by weight of a polyethylene are obtained Bulk weight 420 g / l, the mechanical test values of which are very similar to those given in Example 1. Density: 0.937.

Example 4

40.4 parts by weight of titanium monochloride triethylate with 100 parts by volume of the mentioned in Example 1

1 4203Θ1

th dispersant and diluted in a mixture of 35 parts by volume of ethylaluminium sesquiohloride and 50 parts by volume of the cited dispersant was added dropwise at room temperature over the course of one hour. After the usual work-up, a finely divided brown contact is obtained, its suspension in the dispersant mentioned in Example 1 17.6 mol of titanium (III> compound in 100 volumes contains.

For the polymerization, 115 parts by volume of the contact suspension, 13.4 parts by weight of ethylaluminum sesquichloride in 670 parts by volume of the dispersant, are used and the procedure is customary. After 6 hours of polymerization, 350 g of polyethylene are obtained with a specific viscosity of 3.86, tensile strength 285 kg / cm ² , elongation at break 685% and density 0.939.

Example 5

20th

52.8 parts by weight of orthotitanic acid tetraethyl ester (titanium tetraethylate) are diluted with 30 parts by volume of the dispersing agent mentioned in Example 1 and this mixture is added dropwise to a mixture of 57 parts by volume of ethylaluminum sesquichloride and 400 parts by volume of the above-mentioned dispersing agent over a period of 40 minutes with nitrogen blanketing and stirring. After stirring for several hours, it is worked up as usual. The contact suspension contains 16.8 mmol of titanium (III) compound in 100 parts by volume. Polymerization is carried out in the customary manner with 150 parts by volume of contact suspension and 9.8 parts by weight of diethylaluminum monohydrate in 480 parts by volume of the above-mentioned dispersant. After 6 hours, 530 parts by weight of polyethylene are obtained. Specific viscosity: 6.36; Tensile strength: 255 kg / cm ² ; Elongation at break: 791%; Density: 0.938.

Example 6

In the same way, a catalyst is made from 60.7 parts by weight of tetrabutyl orthotitanate (titanium tetrabutylate) and 45 parts by volume of ethylaluminum sesquichloride in 400 parts by volume of the example 1 mentioned dispersing agent. 100 parts by volume of the contact suspension contain 22 mmol of titanium (III) compound.

For the polymerization, 110 parts by volume of this suspension are used with a solution of 8 parts by weight Ethyl aluminum sesquichloride in 400 volumes of the above-mentioned dispersant, the is allowed to flow in continuously as usual.

After 5 V ₂ hours the yield of polyethylene is 480 parts by weight. The mechanical properties of the product are similar to those described in Example 1.

Instead of titanium tetrabutylate, you can also use titanium tetra- (ß-chloroethyl ester), made by reacting titanium tetrachloride with ethylene oxide. A titanium catalyst is obtained which, in combination with ethylaluminum sesquichloride also converts ethylene into a high polymer.

Claims (1)

Claim: Process for the production of high molecular weight polyethylenes, by polymerizing ethylene with catalyst mixtures of organoaluminum compounds and compounds of the metals titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, thorium and uranium, whereby the catalyst mixtures are obtained by reduction heavy metal compounds formed are separated from the other reaction products and the separated compounds - optionally after further purification - used in any combination with organometallic compounds of aluminum for the polymerization of ethylene, according to patent 1,019,466, characterized in that titanium ( IV) compounds containing organic residues are used. Strains added dropwise. The reaction material changes color Gradually dark brown. After the end of the dropping in, the mixture is stirred for a further 8 hours at room temperature and the dark brown contact formed by the secondary reaction products obtained in the dispersant separated in a stir frit. The contact is then washed twice with fresh dispersant and finally with more Dispersant to form a suspension slurried. 100 parts by volume of the above-mentioned suspension contain 10 mmol of titanium (III) compound. With 200 VolumenteUen this suspension is with continuous dropwise addition of 7.2 parts by weight Ethyl aluminum sesquichloride in 360 volume parts n len of the above-mentioned dispersant polymerized. After 6 hours of polymerization and suitable work-up, 600 parts by weight of polyethylene are obtained. Specific viscosity: 2.06; Tensile strength: 196 kg / cm ² ; Elongation at break: 860%; Bulk weight: 300g / l; Density: 0.927.