DE1643951B1 - Process for the preparation of aluminum alkyl compounds - Google Patents

Description

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The invention relates to the production of aluminum titanium tetraisopropoxide is a preferred example, Miniumalkylverbindungen through a direct Ver can as the sole catalyst additive or add from hydrogen, aluminum and ethylene together with known additives such. B. metallic using catalysts. · Sodium, may be used.

The direct reaction of aluminum, hydrogen 5 It has been found that an increase in the and an olefin with the formation of aluminum alkyl reaction rate mn a factor of about compounds is known (see German patents 25, if for example un-961537, 1031792 , 1118 782 and 1164405). It is also known to about 0.8 percent by weight of titanium tetraisopropoxide that the "activation" of is often used. The Reasons why Aluminum is so effective- aluminum matters. Materials that affect the io speed of the catalyst are not known. From the reaction added for this purpose, the figures given below can be seen to be sodium or others. Alkalis (cf. German patent metallic titanium, titanium hydride and titanium dioxide writing 1116 017). The use of aluminum is not effective as a catalyst, in the form of an alloy containing the addition of a reactivity-enhancing amount of an "activation" of aluminum in the manufacture of one or more of the various catalytic positions of alkylaluminum compounds it is elements, titanium, zirconium, hafnium, vanadium, niobium, surprising that a completely new technique for scandium and uranium, contains, is in the German increase of the production of alkylaluminum. Patent 1181 217 '. These metal compounds have been found to provide a substantial improvement with aluminum peritectic, binary systems 20 with the relative simplicity of the form, and it is said that of the 51 metalli- overall process creates. See the present technique elements, the purpose of the invention were tested alloy in aluminum can advantageously as the sole intention Verdie, only the improvement of this type of reaction and also advanta- (| seven above are as activators suitable adhesive in combination with various already loading ^v According to the US Pat. No. 2,271,956, forms of “activation”, such as those given above, olefin, aluminum and hydrogen, in contrast, can be used Monoalkylaluminum dihalides. Serve the reactants or the reaction elements, which are added as poisons or inhibitors for the mixture itself. The catalyst processes of German patent 1181217 can be added directly or seen in situ from precursors, are obviously activators that actually e Activation of the reaction according to US Pat. No. 2,271,956. Aluminum may be just one of

These above .. activators are in general. several such subsequent reactions, with common impurities, "insofar as a'Tfi-" the catalytic factor influencing the desired rate of high-purity alkylaluminum product, influencing the reaction. We can as well. In addition, some of them, such as titanium, form the catalysts to be used in the present invention, highly active catalysts for the polymerization of titanium-ethylene together with residual materials. For this reason, additive groups have been used in aluminum in the sense that their effectiveness is minimal in the sense that the previous removal of the entire concentration is used, which is difficult since 40 traces of these materials from aluminum do not differ in the concentration requirements is. In many cases, however, it is a considerable number of approaches of the reactants to 1 *; "Desired, because of the transfer to the trialkylands. It was therefore routinely used high-aluminum product working methods that had the activator in a concentration of materials of the titanium group, provided the most unfavorable conditions 45. why it was prefers higher costs is sufficient for. This is especially true for the titanium. _s .größere purity of aluminum in purchase to alloy German Patent 1181217, take there.

Alloys are generally used for variable properties. In the following examples, are known and an additive of the alloy requires two types of aluminum for the same purposes 50 turns are added before the start of the reaction. The first variety (example 1 and 2) "was from must and not after production of the alloy - comparatively high purity in the range of 99.7 times can be changed. It is therefore not less than 99.9% aluminum. The other impurities are common that-generally much larger genes were very small, and one sample was considered to be Tintan amounts of 100 to 500 ppm, as shown in a typical material with a low titanium and silicon content according to the procedure of the German patent «55-salary (less than 50ppm) selected to be listed here 1181217 are sufficient to ferment systems in certain Le- by some alloy activation be used. avoid. The reaction proceeded in Example 1 without

The invention relates to a method for Her- catalyst good, but significantly better from,

Position of aluminum alkyl compounds when a catalyst as in Example 2 is added

Implementation of finely divided aluminum, hydrogen 60 was.

and an olefin in the presence of a catalyst, In Examples 3, etc., a typical techdas was characterized in that the process niche grade an aluminum of lower quality selected from in the presence of about 0.1 to 5 percent by weight, which in previous experiments poor (preferably . adduce 0.04 to 2, and particularly preferably results This material ziem- · <0.05 to 1.0 weight percent) was in the form of a titanium 65 lent low in its iron content, but without a *: or Zirkontetraalkoholates with lower alkyl - remarkable content of a particular encryption * ■ - residues, based on the aluminum feedstock ■ impurity, in particular of titanium and silicon. ^! is carried out. The catalysts of which the following examples explain the invention

dung, the examples 1,3,7,8,9: and 10 dem Serve to compare or contrast.

Example 7

Example 3 was repeated with the addition of 0.036 g of zirconium hydride. The reaction was so slow that a relative reactivity could not be measured.

Example 8
Example 3 was repeated with the addition of

could be.

Example 9 example 1

A mixture of 73 g of triethylaluminum, 35 g of finely divided aluminum powder and 0.3 g of sodium was heated at 140 ° C. in a 250 ml autoclave equipped with a magnetic stirrer under a hydrogen pressure of 71 kg / cm ^2. To the

To keep the pressure constant, hydrogen was added with 10.072 g of titanium hydride. The reaction was carried out as long-71 kg / cm ² continuously to the autoclave from a sam that a relative reactivity of not measured fed 250 ml feed vessel which was maintained at a higher pressure. The pressure drop in the hopper was recorded as a function of time and the maximum drop on this line was taken as a measure of the relative rate of reaction, which changes with the reactivity of the aluminum powder used. A pressure drop corresponding to 15 kg / cm ² in 35 minutes is arbitrarily set as a relative reactivity of 1.00. In this example the relative responsiveness was 0.79. This experimental procedure was chosen because it is typical of the aluminum-plus-hydrogen rate-limiting reaction and the indefinite fact that not only the selection of the metal constituent of the catalyst, such as the hydrogenation of olefin, is important, but that it is

moreover, it is necessary to select the catalyst according to the present invention.

From the foregoing it can be seen that excellent results are obtained where the used catalyst with the actual total titanium group materials in the feed is kept fairly low, e.g. B. in example 5, where the amount of titanium in relation to aluminum

on Al) was used. The relative reactivity 35 is about 0.14 weight percent and the number was 2.23. Show rich experiments that 0.1 and 0.05%> in the all-Example 3 common are entirely satisfactory. Corresponding

about 230, 160 and 80 ppm titanium. The holding

Example 1 was repeated, with an amount below the amount of titanium as low as different aluminum powder quality used 40 possible is of the utmost importance to a low became. The relative reactivity was 0.20. This titanium contamination of the aluminum alkyl products too The same aluminum powder quality was obtained in the incomes because of the disadvantageous catalytic properties

Example 3 was repeated with the addition of 0.02 g of finely divided titanium powder. The reaction was so slow that relative reactivity was not possible could be measured.

Example 10

Example 3 was repeated with the addition of 0.12 g of titanium dioxide. The reaction was too slow to measure a relative reactivity. The unsatisfactory examples 1, 3 and 7 to 10 show

decreased. The results are generally comparable when olefins are used for the entire process.

Example 2

Example 1 was repeated using the same quality aluminum powder and 0.25 g Titanium isopropoxide (= 0.7 percent by weight, based on

play 4 to 10 used.

Example 4

Example 3 was repeated with the addition of 0.25 g of titanium isopropoxide (= 0.7 percent by weight, based on on Al). The relative reactivity was 5.4.

Example 5

Example 3 was repeated with the addition of 0.05 g of titanium isopropoxide (= 0.14 percent by weight, based on on Al). The relative reactivity was 2.2.

Example 6

Example 3 was repeated with the addition of 0.125 g of zirconium isopropoxide (= 0.35 percent by weight, based on Al). The relative reactivity was 3.7.

Effect of titanium and its compounds in the subsequent reactions of the aluminum alkyls.

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Claims (1)

Claim: Process for the preparation of aluminimimalkyl compounds by reacting finely divided aluminum, hydrogen and a Olefin in the presence of a catalyst, characterized in that as a catalyst a tetra alcoholate of titanium and / or zirconium with lower alkyl radicals in an amount of about 0.1 to 5 percent by weight, based on the aluminum, is used.