DE1244412B - Process for the production of polyethylene - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C08f

German class: 39 c - 25/01

Number: 1244 412

File number: R18200IVd / 39c

Filing date: January 26, 1956

Opened on: July 13, 1967

Process for the production of polyethylene

Applicant:

Ruhrchemie Aktiengesellschaft, Öberhausen-Holten

Named as inventor:

Dr. Walter Rottig, Oberhausen-Sterkrade-Nord

The production of polyethylene with a certain degree of polymerisation is particularly technical Interest. The German Auslegeschrift 1178 603 describes a process that the polymerization by regulates the molar ratio of organometallic compound to heavy metal compound. Difficulties become seen in this way of working in the lack of purity of the ethylene, the process of the formation of a able to influence defined and effective catalyst unfavorable. ok

Even with perfect purity of the used
Ethylene, the formation of the catalyst is dependent on various influences, which take certain measures to produce a uniform effect
require eligibility. It was found that for the 15th

Production of polyethylene by polymerization Precipitation of titanium trichloride still contains small amounts of ethylene in the presence of inert hydrocarbons, amounts of aluminum compounds, which are rewashed 4 to 5 times by means of catalysts as auxiliary liquids, ζ. Β. can be removed with a hydrogenated from a mixture of aluminum triethyl and / or diesel oil fraction. These aluminum diethyl monochloride or aluminum monochloride filtrates are generally not added to the first ethyl dichloride with a suspension of titanium trichloride filtrate, since this often results in an unin inert hydrocarbons, with the desired dilution being achieved. Basically, through conversion of the titanium trichloride approximately stoichiometrically, however, all filtrates of mixed amounts of titanium tetrachloride and aluminum can be combined with one another. The filtered and well-washed miniumtrialkylene and / or aluminum monohalogenous titanium trichloride, which is now free of titanium tetrachloride, dialkylene in inert hydrocarbons, is separated off and reused as a suspension. Therefore, one adds to the precipitate, repeatedly washing out the hydrogenated, completely anhydrous diesel oil, for example, with the exclusion of air and moisture, and shakes it vigorously. The suspension can be kept as a suspension in an inert hydrocarbon for a longer period of time, if it has been completely recovered, works particularly favorably in such a way that the exclusion of moisture is ensured,
the polymerization is carried out in such a way that, according to one embodiment of the process, can

that the catalyst mixture of titanium trichloride and the first washing oil from the TiCl _s -production ^ as an organoaluminum compound when using a solvent for the catalyst batch for the ethylene of aluminum triethyl a concentration of we-polymerisation are used. Was aluminum less than 0.004 mol of aluminum triethyl per liter, at 35 diethyl monochloride reacted with titanium tetrachloride, use of aluminum diathyhnonochloride more so the filtered mother liquor aluminum is 0.002 mol aluminum diethyl monochloride per liter of dichloromonoethyl. Then it is washed 4 to 5 times with and when using aluminum monoethyldi- H ₂ O- and O ₂ -free diesel oil. The chloride more than 0.005MoI aluminum monoethyl first wash filtrate can advantageously be used as suspension dichloride per liter, based on the total amount of the liquid for the TiCl ₃ produced, liquid present at the beginning of the polymerization a molar ratio of titanium tri-moisture can be worked. Under certain circumstances, however, it is possible to use chloride for the organoaluminum compound of 2 to 0.3: 1 for the other wash filtrates. to be used individually or in combination with another

The separation of the titanium trichloride precipitate from 45 turn. Whether the wash filtrates are suitable for use with the aluminum haloalkyl solution, which is excluded as suspension liquid, depends on the presence of air and on moisture of any kind, the Al content of the first wash filtrate. It is important that the Al content of this filtrate is not high, and that the Al content of this filtrate is not high. 50 mg / 1, substance, as protective gas. On a laboratory scale, 50 should preferably be less than 5 mg / 1, not exceeding
normal glass frits for such a separation The mother liquor, which contains the Al-alkylhalogen-

well proven. The component then remaining on the filter contains which, according to the stoichiometric

3 4

metry of the starting component was created diesel oil) aluminum diethyl monochloride and 0.81 g must, so z. B. given according to the equations TiCl ₃ (0.0029 mol per liter). Reaction temperature turn 70 ⁰ C. Within the first Al (C ₂ Hg) ₃ TiCl ₄ = -f AlCl (C ₂ Hs) ₂ + TiCl ₃ or 15 minutes an uptake of 121 Ethylene

AlCl (C _a H _ä ) ₂ + TiCl ₄ = AlCl ₂ (C ₂ H ₅ ) + TiCl ₃ or ^{3 reach} ^ \} *** ■ ⁷ ? ^Min ^ ^{was the} ethylene uptake

⁴ of 21/15 minutes decreased.

Al (C ₂ Hs) ₃ + 2 TiCl ₄ = AlCl ₂ (C ₂ H ₅ ) + 2 TiCi ₃ At this point in time, 0.81 g of _{TiCl s} suspension was obtained

admitted. Then occurred in the next 15 minutes

can of course in the production of poly- strong increase in the ethylene uptake a (191/15 for which the relevant aluminum grooves). After some time (about 3 hours after the verminium alkyl halogen compound is required, start of the experiment), however, the absorption was at 51/15 Miwendet will. grooves decreased, whereby it remained approximately constant.

The molar concentration is of considerable importance. After 4 hours, 45 minutes were the solution

tration of the mixture. The final concentration added 0.42 g of aluminum monochlorodiethyl. Now at aluminum alkyl and / or haloalkyl it is said that for ig there occurred, albeit less, but clearly more measurable, the polymerization approach to below 0.01 mol per increase in the ethylene absorption. It was to be set per liter. When using Al (C ₂ Hg) ₃ 15 minutes now 71.

is at concentrations below 0.004 mol per After 5 hours, 45 minutes were again

Liters, preferably below 0.0025 mol per liter, added to 0.81 g of TiCl ₃ in the solution. Working off the ethylene. If A1C1 (C ₂ H ₅ ) _{2 is} used, the sorption must have increased from 7 to 211 in 15 minutes, but the concentration fell by more than 0.002 mol per liter, e.g. B. relatively quickly again to be during the 0.003 to 0.005 moles per liter. During the following hours at 8 liters of ethylene / 15 minutes, AlCl ₂ (C ₂ H ₅ ) as an aluminum alkyl compound should remain constant.

more than 0.005 moles per liter are used, preferred In the last experiment 0.4 g of aluminum triethyl were used

wise 0.006 to 0.1 moles per liter. 25 (0.002 mol per liter) and 0.81 g TiCl ₃ (0.0029 mol

A mixture of aluminum is used in the production exclusively high mol per liter), dissolved in 1800 cm ^{3 of} diesel oil, as the starting polyethylene. In the first 15 minutes, alkyl and / or haloalkyl and TiCl ₃ without any extraordinarily high ethylene absorption from further addition of titanium tetrachloride for the polymerization were found for 601/15 minutes. After that, all-use occurred, so in the above case one obtains a gradual decline under Appropriate. After applying the usual polymerization conditions, the absorption was 261 for one hour, 131 after 2 hours, ie at temperatures between 60 and 100 ° C., 101 after 3 hours, 81 after 10 hours. B. everything per 15 minutes. Even after an operating time of 10 to 50atü, between about 180 and 200 ° C of 10 hours, there was still an absorption of melting material with a high molecular 35 4 to 51 ethylene / 15 minutes,
has weight. Of the three aluminum alkyl or the following yields of polyethylene show

Haloalkyl compounds: trialkyl, monohalogen- clearly the superiority of the mixture aluminum dialkyl and dihalogenmonoalkyl, which for the triethyl -j- TiCl ₃ in comparison to the other aluminum positions of high-melting polyethylene in miniumorganic compounds,
Binding with TiCl _{3 are} particularly favorable, indicates a 40 gram yield

again the combination aluminum _{trialkyl + TiCl 3} after polyethylene

in terms of reaction rate and yield ³ ₊ ^Stul l ^den _I '/ * ^{5 Mi} ? ^u "

. j .. .. ^ö _. , ",", .. ^. th response time

particularly favorable properties. Very cheap.,.,.,. . ^ ...,, "._

Yields and conversion rates are obtained using triethylaluminum. 350

is sufficient if the ratio of titanium trichloride and ₄₅ J ** monochlora uminium diethyl 120

organoaluminum compound to 2 to 0.3 mol, ^Mii Monoethylalumimumdichlond 77

preferably 1.5 to 0.5 per mole of aluminum compound. After a reaction time of 9 hours, the yields were

application is set. as follows:

Example with aluminum triethyl 500

_T τΐί j τ, »1 ο- o j ⁵ ° With monochloroaluminum diethyl 350

In a stirrer vessel with a capacity of 31, about ... 90

complete exclusion of moisture a mixture ^J

of 1.8 g of aluminum dichloromonoethyl (0.008 mol to determine any differences in

per liter) and 2.43 g of TiCl ₃ (0.0087 mol per liter), the addition of aluminum triethyl and TiCl ₃ im

which was compared to the two previous attempts by the conversion of TiCl _{4 with aluminum diethyl 55}

monochloride and repeated washing out of the filtrate from the last experiment (duration of the experiment

maintained precipitation, as well as 9 hours) including the run through with diesel oil

1800 cm ^{3 of} absolutely dry diesel oil at one temperature - three washes (all measures

temperature of 70 ° C. Thereafter, with the inclusion with exclusion of oxygen and moisture) for

started to conduct ethylene. The uptake was 60 used a retry

in the first quarter of an hour 171 to within the total of 1800 cm ^{3 of} filtrate + washing liquid

3 hours to go back to 3 liters in 15 minutes. were initially on their own at one temperature

An addition of 0.81 g of TiCl ₃ (0.0029 mol per liter) from 70 ° C to their reactivity by introducing

had the ethylene conversion tested again to 101 in 15 minutes of ethylene. However, there was no measurable one

which then slowly increases to 21 per 15 minutes 65 absorption.

fell off. An addition of 0.81 g of TiCl _{3 also} resulted in

In a further experiment, no measurable results were found in the initial half of the subsequent 30 minutes

Approach 0.42 g (0.002 mol per liter) (per 1800 cm ^{3 of} ethylene uptake.

Immediately thereafter, 0.4 g of A1 (C ₂ H ₅ ) _{3 was} added. About 401 of ethylene were absorbed in the following 15 minutes. However, after 75 minutes, the uptake had decreased to 111/15 minutes.

An addition of 0.4 g of TiCl ₃ , ie only 50% of the amount normally used in the other experiments, resulted in an increase in the ethylene uptake to 251/15 minutes. There was a gradual decline. After 3 hours and 30 minutes, the ethylene uptake was still 61/15 minutes.

0.2 g of aluminum triethyl were then added, half the amount at the start of the experiment had been applied. In contrast to the first, but also to the second comparative experiment, one occurred sudden increase in ethylene uptake from 6 to 241/15 minutes. Then there was another gradual decrease, so that after 6 hours the ethylene uptake was only 61/15 minutes.

In contrast to aluminum monochloro diethyl, but especially monoethyl dichloride, mine already show Amounts of aluminum triethyl have a strong activating effect on ethylene absorption.

The melting points of all products were low after previous sintering between about 180 and 185 ⁰ C. Only the product using dichloride melted already 176-183 ° C. It is apparent from this that, regardless of the type of aluminum alkyl compounds with the addition of only TiCl ₃ high molecular weight polyethylenes are obtained in all cases.

Claims (5)

Patent claims: 1. Process for the production of polyethylene by the polymerization of ethylene in the presence of inert hydrocarbons as auxiliary liquid by means of catalysts from a mixture of aluminum triethyl and / or aluminum diethyl monochloride or aluminum monoethyl dichloride with a suspension of titanium trichloride in inert hydrocarbons, the suspension of titanium trichloride through the conversion of approximately stoichiometric amounts of titanium tetrachloride and aluminum trialkylene and / or aluminum monohalodialkylene in inert hydrocarbons, Separating the precipitate, washing it out several times with the exclusion of air and moisture and suspending it in an inert hydrocarbon has been obtained, characterized in that the Polymerization is carried out in such a way that. the catalyst mixture of titanium trichloride and organoaluminum compounds when using aluminum triethyl a concentration of less than 0.004 mol of aluminum triethyl per liter, when using aluminum diethyl monochloride more than 0.002MoI aluminum diä & ylmonochlorid per liter and when using. Aluminum monoethyl dichloride more than 0.005 mol of aluminum monodiethyl dichloride per liter, based on the total amount at the beginning the liquid present in the polymerization, and a molar ratio of titanium trichloride to the organoaluminum compound of 2 to 0.3: 1 is observed. 2. The method according to claim 1, characterized in that the first wash filtrate from the _{TiCl 3} production is used as a suspension _{medium for the TiCl 3 produced.} 3. The method according to claim 1 and 2, characterized in that the mother liquor from the TiCl ₃ production is used for further polymerization batches. 4. The method according to claim 1 to 3, characterized in that an aluminum trialkyl together with TiCl _{3 is used} as a catalyst for the production of high-melting polyethylenes. 5. The method according to claim 1 to 4, characterized in that the setting of the molar ratios is carried out by adding in portions of TiCl ₃ or organoaluminum compound in the course of the polymerization. Considered publications:
Belgian patent specification No. 546 846. 709 610/536 7.67 © Bundesdruckerei Berlin