DE1294659B - Process for the production of polyethylene - Google Patents

Description

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It is known to use ethylene at pressures below aluminum compound, while for manufacture approx 100 atm and at temperatures up to about 100 ° position of low molecular weight products with Molgezu polymerize. In this process one works with weights of about 20,000 and 30,000 and melting Catalysts made from mixtures of metal points between about 125 and 140 ° mixtures of organic compounds, in particular aluminum-aluminum compounds with over 0.1 mol of titanium tetraalkyl compounds and / or aluminum haloalkyl chloride and at least 0.1 mol of titanium trichloride, compounds, with compounds of the metals of the 4th both based on 1 mole of the aluminum compound, to 6th subgroup of the periodic system, ins- are applied and also the in the special with titanium compounds, exist (see starting catalyst mixture present titanium tri- "Angewandte Chemie", 67, 1955, pages 541 to 547, io chloride not by reacting aluminum alkyl as well as the Belgian patents 533 362 and / or haloalkyl with titanium tetrachloride, but 534 792). In this synthesis is generally in a known manner by passing over a Polymerized in the presence of an auxiliary liquid. As hydrogen saturated with titanium tetrachloride The auxiliary fluid is hydrocarbon - a tube exposed to silent electrical discharges Fractions in the gasoline or diesel oil sector. Which is made after 15. The production of titanium trichloride Polyethylenes produced using the new process are known (cf. Gmelin »Handbuch der Anorgaim In contrast to the well-known high-pressure niche chemistry ", Vol. Titan, page 294, as well as F. Emisch, process produced polyethylenes extraordinarily monthly for chemistry, vol. 25 [1904] page 907 bis high molecular weights from 20,000 to more than 912).

1 000 000. ao That, for example, by passing over a titanium tetra-

The adjustment of different molecular weights of chloride-saturated hydrogen by a silent elekbei The tube exposed to the polymerization of ethylene requires substantial discharges Lent changes in the composition of the cata- titanium trichloride is practically pure and does not contain any sators. The subject of patent 1244 412 is a disruptive amount of titanium tetrachloride. However, it is drive to the production of polyethylene, in which as expedient, the titanium trichloride formed or the ratio of the aluminum compound to the two twice with diesel oil or gasoline, the one possible Titanium chlorides are supposed to have a guided shift in the low oxygen content, to shake Molecular weight is crucial. Likewise, and then decant. Be that way in this patent a special way of producing small, possibly still existing remnants Titanium trichloride is suggested to be one with 30 titanium tetrachloride with certainty removed. That especially Titanium trichloride which has remained successful as a catalyst component is useful in diesel oil using titanium trichloride leads. The suspended here is canceled and has been written down for several weeks Type of production of the titanium trichloride by unchanged shelf life. When using it will however, it also has not inconsiderable disadvantages. After vigorous shaking of the suspension, one is removed the corresponding stoichiometric amount is always deducted and the aluminum metric Amounts of an aluminum alkyl and / or catalyst added. The concentration of diesel halogen compound, e.g. B. according to the equation oil suspension of titanium trichloride can in the usual way,

determined for example by a chlorine determination

2 Al (CgH _s ) ₃ + 2 TiCl ₄ = 2 Al (C ₂ Hg) ₂ Cl + 2 TiCl ₃ , since the resulting titanium trichloride is practically + C ₄ H ₁₀ . 4 ° corresponds to the stoichiometric form of the TiCl _3. It

however, it is also possible to use the solid, powdery

Apart from the associated, not _{misshapen TiCl 3} in solid form under a protective gas, it is also at considerable costs with some catalysts. B. highly _{purified N 2} to store, Satorgemischen, especially if it is z. B. to

those that are exclusively high-molar 45 Example

Cular polyethylene is to be produced, undesirable, instead of two components in defined quantities - through a glass tube of 15 mm clear width and four components in confusing quantities - 20 cm in length, which has a double jacket to proportions. In addition, in these cases, cooling or heating should be surrounded and, if possible, no titanium tetrachloride should be present. So far, having been exposed to 50 electrical discharges, it was only possible to use the cumbersome and at room temperature very pure hydrogen, which had passed through saturators filled with TiCl _{4, which was previously expensive by way of conversion of aluminum alkyl.} The and / or haloalkyl with TiCl ₄ and the amount of hydrogen filtered off was 161 / hour. There were per and washing out of the precipitate a TiCl ₃ for the hour 0.5 g TiCl ₃ obtained, which produce practically pure polyethylene synthesis. 55 were, but once again with pure before use. It was found that the production of high-diesel oil was washed out.

Molecular polyethylene according to Ziegler in counter-In a reaction vessel of 31 contents were

War of polymerization exciter mixtures, which consists of 1800 g of pure, oxygen-free diesel oil (ppm value <10) of an organoaluminum compound, TiCl ₃ and with 0.34 g of aluminum triisobutyl and 0.4 g of the above TiCl ₄ , in a much simplified manner. 60 TiCl _{3 produced were} added. The following can be carried out, if you can achieve polymerization of ethylene, which has an Og value of high molecular weight products with molecular weights above 8 ppm, at a temperature of half about 150,000 and with melting points above 70 ° in 3 hours about 500 g of polyethylene with a 170 ° mixture of an aluminum alkyl and / or viscometrically determined molecular weight above aluminum haloalkyl with amounts of titanium trichloride 65,500,000.

of at least 0.01 mol, based on 1 mol of the. With a temperature increase of the discharge aluminum compound, and amounts of titanium tetra tubes to 50 °, an increase in _{TiCl 3} -AuS chloride below 0.1 mol, based on 1 mol of the prey on 0.6 g / h to be established.

Claims (1)

Claim: A process for the production of high molecular weight polyethylene according to Ziegler in the presence of polymerization exciter mixtures which consist of an organoaluminum compound, TiCl ₃ and TiCl ₄ , characterized in that, in order to obtain high molecular weight products with molecular weights above about 150,000 and with melting points above 170 °, mixtures of Aluminum alkyl and / or aluminum haloalkyl with amounts of titanium trichloride of at least 0.01 mol, based on 1 mol of the aluminum compound, and amounts of titanium tetrachloride below 0.1 mol, based on 1 mol of the aluminum compound, while for the production of low molecular weight products with molecular weights of about 20,000 and 30,000 and melting points between about 125 and 140 ° Mixtures of aluminum compounds with more than 0.1 mole of titanium tetrachloride and at least 0.1 mole of titanium trichloride, both based on 1 mole of the aluminum compound, are used and also the one present in the starting catalyst mixture Titanium trichloride is not produced by reacting aluminum alkyl and / or haloalkyl with titanium tetrachloride, but in a manner known per se by passing hydrogen saturated with titanium tetrachloride through a tube exposed to silent electrical discharges.