DE1420732C - Process for the production of polyolefins - Google Patents

Description

1 2

The Ziegler process for the polymerization of brown amorphous modification, which can be used for example low molecular weight olefins to high molecular weight by conversion of TiCl ₄ with aluminum plastics as catalyst components trialkylene, between 0.2 and 5, preferably compounds of I to III. Group is between 0.5 and 3. Very often the periodic system, in particular aluminum and larger amounts of the higher valency organic compounds, will be present in combination with stages of the above elements, e.g. B. bindings IV. To VI. Subgroup of the periodic tetravalent titanium compounds, in particular the Titan system, z. B. those of titanium, in particular halogen compounds, for example TiCl ₄ . Purpose in the form of the halides. With the help of this catalyst, the proportion between 0.1 and 5 mol, belysatoren is already obtained at normal pressure, but is particularly favorable between 0.25 and 2.5 mol, even at elevated pressures, for example poly the molar aluminum ethyls, soft a melting point of up to 137 ° C component = 1, the proportion of silicon tetrachlobes can have a largely linear structure, ie verrid and / or dimethylsilicon dichloride (CH ₃ )., SiCl ₂ contain relatively few branches, and 0, 1 to over 100,
have a high crystallinity. 15 To achieve a distinct effect, it is

It has been found that improved results - expediently to choose the proportion of silicon compounds in the process for the polymerization from not too low, for example not from low molecular weight aliphatic olefins under 0.5, while in general the maximum amount from Catalysts, which should be from mixtures of around 50. Since the compounds of the invention from I. to III. Group of the periodic ao method of operation is advantageously carried out using a system, preferably organoaluminum suspension liquid, should the bonds with compounds of IV. To VI. Secondary molecular concentrations of the aluminum compound group of the periodic system, preferably not too high and titanium, exist at pressures up to about 100 kg / cm ^2, for example less than 0.05 mol / l, advantageously each and temperatures up to 100 ° C is obtained when 35 is less than 0.01 mol / l. The lowest one the catalyst mixture before or during the concentration of aluminum compounds should be polymerization silicon tetrachloride and / or di- about 0.00025, appropriately 0.001 mol / l,
methyl silicon dichloride (CH ₃ ) _? Adds SiCl ₂ . This implementation of the polymerization takes place in silicon compounds are known in the course of the poly, advantageously using a merization in the forming polyolefin molecule 30 suspension liquid, which is incorporated in accordance with the instructions, bring about a crosslinking of the high molecular weight of the literature of oxygen-containing connective polyolefins, whereby improved firming fertilizers of any kind are released. Expediently, increase the oxygen resistance, use aliphatic, naphthenic or aroma-like polymers and, in addition, have table hydrocarbons with a carbon number between still further advantages, which relate to the course of 35 about 5 and 15. The reaction temperatures depolymerization and the mechanical behavior of the speak the state of the art, for example, have beneficial effects between standing polymers. see around 40 and 100 ° C. The applicable

For the method of operation according to the invention, pressures are between approximately 1 and 100 ata. The mixtures of the known so-called Ziegler-Natta polymerization can be used continuously or from catalysts. It is advantageous, for example, to carry out 40 batches,
wise organoaluminum compounds, e.g. B. Aluminum A favorable effect, due to the addition of miniumalkyls and / or haloalkyls and aluminum of silicon compounds, on the course of the Polyminiumalkylate, in combination with titanium, vanadium and the behavior of the resulting, dium and zirconium compounds, in particular Titanium polyethylene is achieved when, based on halogen compounds. Of the organoaluminum 45 aluminum = 1, at least 1 mol of silicon compounds can be used primarily for fertilization, for example SiCl ₄ . In the case of high production of low molecular weight polyolefins, in particular turnover numbers, for example in the conversion of special polyethylene, aluminum dihalogen mono-ethylene to polyethylene, the mass is advantageously used after an alkyl compound. for a time stiff and firm, because of the educated

It is advisable to mix all of the catalyst components required for the polyethylene, a more or less large amount of merization, suspension liquid, which is bound by swelling, including the intended amount of silicon. It has been shown that when SiCl ₄ compounds are added before introduction into the reactor in one of the amounts specified above, this swelling in a special vessel and possibly leaving it is reduced to a considerable extent, which results in a certain time, expediently 15 to 60 minutes , has in common that the masses react to one another for a much longer period of time. However, it is also possible for the space to remain stirrable. This allows a higher give the compounds directly in the reactor conversion of monomeric olefins, eg. B. ethylene, either together or one after the other, a longer period of time compared to Vermen, however, in such cases, the yields and turnover figures achieved are generally somewhat lower without the addition of silicon compounds. Turn 60. The increase in sales requires

In the preparation of the catalyst mixture it is important that the performance of the catalyst is considerable

the ratio of the Al compounds to the Ti increases and the space-time yield also increases.

ties important. For example, one denotes borrowed increases.

the molar proportion of organoaluminum compounds. The processing of the polyolefins incurred, compounds with 1, it is expedient that the 65, in particular of polyethylene, is carried out in a known molar amount of compounds of lower valency, e.g. B. using alcohols, keitsshifen, especially the heavy metals titanium, optionally in mixtures with hydrocarbon vanadium and zirconium, z. B. TiCl ₃ , in particular the substances and / or the addition of acids, for example

3 4

Hydrochloric acid or acetic acid. Surprisingly, it is compensated by increased introduction. After a

by this treatment the silicon component from reaction time of 6 hours was a conversion of

not detached from the polyethylene. In numerous 6601 ethylene achieved without the catalyst to

In some cases, the application of a water- this time was exhausted. The attempt was made

containing aliphatic alcohol with a carbon number 5 then canceled and the mass for removal

between 1 and 10, preferably between 2 and 5, of the trimer propylene first filtered and then

In these cases, the water content should be treated several times with isopropanol, whereby

about 10 and 50 percent by volume. In some a part of the catalyst could be removed.

Cases is the use of two- or three-valued- Another attempt was made as above

gen alcohols, e.g. B. glycol or glycerine, possible. 10 wrote, carried out with the exception of the

TiCl ₄ amount the proportion of the other three components remained unchanged. The amount of TiCl ₄ was

Examples reduced from 0.66 to 0.33 g.

After a reaction time of 6 hours, a

»5 conversion of 400 1 ethylene can be achieved as

1. 0.34 g of aluminum triisobutyl, 0.27 g of one of the above has been worked up.

Conversion of titanium tetrachloride with aluminum triiso- In a further experiment, the original

butyl in a molar ratio of about 1: 1, the amount of TiCl _{4 produced} was reused, but the

and carefully increased from 0.3 to 0.6 now with oxygen-free hydrocarbon SiCl ₄

Tissue-washed TiCl ₃ and 0.3 g silicon 20 sets. After a reaction time of 6 hours could

tetrachloride were found in 100 cm ^{3 of} a careful conversion of 940 1 of ethylene. Loading

Wrinkled hydrogenation and drying of oxygen- it was remarkable that the mass was in contrast to

containing compounds, oxygen and water, the two previous attempts are combined in one

Free diesel oil from the Fischer-Tropsch synthesis was in a very stirrable and mobile state,

put together and left to stand for 15 minutes. The work-up was carried out as previously described.

In a glass reaction vessel with a capacity of about 5 l. In a further experiment, TiCl _{1 was} reduced to 0.33 g

which has a highly effective stirrer, one entry reduced, while the SiCl ₄ amount is 0.6 g

and outlet nozzle for introducing the olefin as well as was left. After 6 hours there was a conversion

contained a temperature ^{measuring tube, 1800 cm 3} of 4501 ethylene were found. The attempt

of the same diesel oil was added, then 30 was then followed for a further 15 minutes

was heated to 70 ° C, the above catalyst continued with gentle stirring at room temperature

Approach added and set immediately with the introduction, whereby an additional 2301 ethylene converted

started from ethylene. After a trial period of could be. The processing of the product

5 hours was a total conversion of 500 liters of ethylene followed tn the manner already described,
achieved. The catalyst at this point was 35. It became a mixture in a final run

but not exhausted yet. of 0.21 g of aluminum monochlorodiethyl, 0.27 g

The experiment was then stopped and the TiCL _1,. 0.66 g of TiQ ₄ and 3.5 g of SiQ _{4 brought} to the reaction of the polyethylene formed by repeated treatment, a conversion with ethanol partly of aluminum and titanium from 6501 of ethylene was found within 6 hours. At this point it is free. The test was terminated viscometrically at 135 ° C. in Dekahydro 40, although the molecular weight determined by catanaphthalene was 900,000. The analyzer was not yet exhausted and the mass was still very stirrable instead of the above amount of SiCl ₄ .

Amount used, there was a slight decrease The work-up was the same as for the previous

of sales. previous attempts.

When using ten times the amount of SiCl ₄ , the viscosimetry in decahydronaphthalene decreased 45

the conversion to be determined within 5 hours 1350 c determined molecular weights in the order

to about half. of the above attempts were as follows:

An examination of the physical and mechanical properties showed a tear strength of 76,000
correct at 120 ° C, from 270 for the product of 50 108 000
smallest amount of SiCl ₄ , which in the second attempt to 80,000
300 and increased to over 360 on the third attempt. 122,000
The elongation at break increased from about 750% of the first 95,000
Product to about 550% of the last product.

2. A catalyst batch consisting of 0.21 g 55. The tear strength was determined with aluminum monochlorodiethyl, 0.27 g of a TiCl ₃ prepared as above at 120 ° C. The following values in the order described above, 0.66 g TiCl ₄ pending were found (in the brackets are both 0.30 g SiCl ₄ and values from comparable tests without addition of silicon tetrachloride for a period of 15 minutes at room temperature):

let go of yawing. 60

In a reaction vessel as described in Example 1 44 (40)

ben, 1800 cm ^{3 of} a hydrogenated Trimerpropy 50 (47)

lens, which has a ppm value of 5, determined against 47 (40)

Isopropyl potassium, had, filled and the above 62 (55)

Added catalyst batch. Under weak 65 60 (45)
Discharge of ethylene was on as quickly as possible

heated to a temperature of 70 ° C and with 3. The experiments 3, 4

increasing temperature, increasing ethylene conversion and 5 were repeated, but with the lower

differed that instead of SiCl ₁ about the equivalent crowd

CH ₁

Cl

was applied. The conversion figures obtained after 6 hours of reaction were:

8901 4201 6001

10

The molecular weights determined as above were ₇₀ Q ₀₀

000.

90000

When determining the tear strength, the following values were achieved:

45 µ

Claims (2)

Patent claims: 1. Process for the polymerization of low molecular weight aliphatic olefins using catalysts which are obtained from mixtures of compounds from I. to III. Group of the periodic system, preferably organoaluminum compounds, with compounds of IV. To VI. Subgroups of the periodic system, preferably of titanium, exist at pressures up to about 100 kg / cm * and temperatures up to 100 ° C, characterized in that silicon tetrachloride and / or dimethylsilicon dichloride (CHj) ₄ SiCl _{2 are} added to the catalyst mixture before or during the polymerization will. 2. The method according to claim 1, characterized in that 0.1 to 100 mol, advantageously 0.5 to 50 mol of silicon tetrachloride and / or dimethyl silicon dichloride (CHj) ₁ SiCl is added to 1 mol of the aluminum component of the catalyst mixture.