DE1115024B - Process for stabilizing catalysts suitable for the polymerization of conjugated diolefins - Google Patents

Description

The invention relates to a process for stabilizing soluble catalysts which are obtained by combining compounds of the general formula AlR ₂ X, in which R is an alkyl, aryl or alkylaryl radical and X is halogen, with other compounds of the general formula MY ₂ , in which Y is an anion and M is a metal of Group VIII of the Periodic Table of the Elements. Such catalysts, which are referred to below as catalysts of the type described, are suitable for the polymerization of conjugated diolefins, in particular of 1,3-butadiene.

It is known that for the polymerization of butadiene to form 1,4-cis polymers, catalysts which are soluble in hydrocarbons and which are produced by the reaction of soluble cobalt salts or complexes, for example CoCl ₂ · 2C ₅ H ₅ N (in which

C ₅ H ₅ N

Pyridine means

with dialkyl aluminum monohalides, for example Al (C ₂ Hg) ₂ Cl. The reaction product is extremely soluble, for example in benzene, and the solutions obtained are clear and slightly yellow. However, these solutions are not stable, and after a few hours a black, solid product separates out of the solutions at room temperature, which gradually lose their activity.

The stability of the catalytic complex is strongly influenced by the temperature; for example a catalyst that was manufactured at 50 ° C turns brown and loses it during manufacture its activity almost instantly; if the catalyst is made at 30 to 35 ° C, it remains few Stable for minutes, and even when made at room temperature or at a lower temperature and is stored, the solution completely loses its catalytic effectiveness after 12 hours.

This effect is increased when the catalyst is made in a metal vessel, especially when this has a rough and corroded surface. A mirror smooth or at least a carefully smoothed one metallic surface has a negligible effect, while a rough surface has a very negligible effect rapid change of the catalytic solution in weni-process for stabilization of catalysts suitable for the polymerization of conjugated diolefins

Applicant:

Montecatini Soc. Gen. per l'Industria Mineraria e Chimica, Milan (Italy)

Representative: Dr.-Ing. A. v. Kreisler,

Dr.-Ing. K. Schönwald,

Dipl.-Chem. Dr. phil. H. Siebeneicher

and Dr.-Ing. Th. Meyer, patent attorneys,

Cologne 1, Deichmannhaus

Claimed priority: Italy of March 18, 1959 (No. 4781/59)

Umberto Maffezzoni and Ermanno Susa,

Milan (Italy) have been named as inventors

is carried out in the same autoclave, but this has been polished beforehand.

All of these facts are not so important when using the catalyst in batch laboratory tests is used, the inner surface of the autoclave can be polished and the time it takes in generally between the formation of the catalytic complex and the introduction of the monomer into the Reaction system elapses, is on the order of a few minutes. The conditions for a However, continuous polymerizations are such that by a considerable change in the catalyst a significant change in the course of the polymerization is also brought about. In the continuous

in minutes. For example, the polymerisation takes place between the polymerisation of butadiene with soluble catalysts position and the use of the catalyst more does not, or proceeds only with very little conversion, if it is carried out in an iron autoclave by known processes is carried out, the inner surface of which has been roughened by sanding. On the other hand, the 50 Reaction using the same starting materials normal with total sales if they

Time. In addition, the catalyst complex must be passed through pipes, the inner surface of which is not polished can be. All of this causes a considerable change in the state of the catalyst, which sometimes, when it reaches the polymerization reactor is completely ineffective.

109 708/445

3 4

It has now been found, surprisingly, that 93 g of dry polymer with the following

Changes in the condition of the catalyst are avoided and the properties are preserved:

if the catalyst is viscometrically determined in the presence

produced from very small amounts of diolefins molecular weight 480,000

^wi "* · _,, ^",. .-. xr _, ⁵ Infrared analysis:

The invention relates to a process for trans-1 4 2 9%

Stabilizing a catalyst of the described trans-l'2 ....] ............. 3'5%

Type in which a diolefin either corresponds to the formed cis-l'4 "" ' 936%

Catalyst or one or the other component

of the catalyst added during its formation 10 If the above catalyst solution after 12 hours

will. Store in a dark glass bottle at normal

The diolefin can be added to the solution of the organometal light and at a temperature of 20 ° C verenlischen the compound or the compound or the det is achieved in the above procedure after complex of the metal of the VIII. Group or 3 hours no conversion of the monomer .
Catalyst added immediately after its formation. If the catalyst solution can be stored in a dark glass, bottle at 6 to 8 ° C for 12 hours in the dark

The small amount of added diolefin is, under the same polymerization, for example 1,3-butadiene, stabilizes the catalyst conditions 21 g of dry polymer, which is retained with the composition following infrared analysis so that it shows its original activity for a long time. A catalyst stabilized in this way can hold 20:
can even be kept for several days. trans-1.4 11.2%

The effectiveness of the catalyst can be extended trans-1.2 16.5%

if the solution is kept in the dark cis-1.4 72.3%

and / or the storage temperature is lowered

will. In general, the stabilized catalyst retains 25 When working under the same conditions, but sator at 20 ° C reverts to its original activity using a catalyst solution that is insufficient long for normal requirements. Immediately after its production, add 3 g of butadiene Lifespan, up to a few days, can be reached and stored in a metal vessel at 15 ° C for 24 hours, when the catalyst is stored at these temperatures, 97 grams of dry poly will be obtained 10 ° C. Get 30 meres with the following properties:

The amount of di-viscometrically determined required for stabilization

olefin is very low and has a molecular weight of around 402,000

from about 50 to 200 moles per mole of the

Group VIII metal contained sator. Higher trans-14 3 9%

Quantities can be used safely, are ₃₅ trans-l'2 29 ° /

but not necessary. The cis-l'4 used as a stabilizer 932 ° /

Diolefin is advantageously, but not more necessary- '". '

wise the same that is polymerized. ". · 1 ο

As stated above, the so stabilized kata- "

lysator complex stored and also in unpolished ₄₀ 3 1 catalyst solution, as in example 1

Metal vessels are used provided that they are described, manufactured.

these are really dry. 1 1 of this solution is in a glass bottle

τ, · ·, -j 16 ° C kept in the dark for 45 hours and then

^e P for the polymerization of 100 g of butadiene among the

In a previously cleaned, dried and eva- _{45 the} same conditions as described in Example 1,

kuierten 6-1 flask, which is used in a thermostatic bath. There will be a conversion of polymers of

located at 14 ° C and provided with a stirrer 4.7% (infrared analysis: trans-1.4 = 2.2%; trans-1.2

is, 5 l of a catalytic solution that = 2.2%; cis-1,4 = 95.6%).

166.5 mmol of Al (C ₂ H _ä ) ₂ Cl and 0.52 mmol of CoCl ₂ - another liter of this solution is after addition

2C ₅ H ₅ N contains, prepared as follows: 50 of 0.189 g of butadiene (35MoI C ₄ H ₆ per mole of Co)

515 ml of a benzene solution containing 1 mmol per liter is stored in a glass bottle for 45 hours at 16 ° C.

Contains CoCl ₂ · 2C ₅ H ₅ N, slowly in 10 to He is then used to polymerize 100 g of butadiene,

12 minutes at 14 ° C with stirring to 4485 ml of one as described in Example 1, used. It will be a

Benzene solution, the 37 mmol per liter of Al (C ₂ H _s ) ₂ Cl conversion to polymer of 22.5% (infrared analysis:

contains, added. ₅₅ trans-1.4 = 2.2%; trans-1,2 = 2.1%; cis-1.4

~~ 1000 ml of the solution obtained in this way are immediately obtained in = 95.7%).

a carefully cleaned, dried and evacuated. The remaining amount of catalyst is 0.378 g

_{Butadiene (70MoI C 4} H ₆ per mole of Co) was added to a 2000 ml stainless steel autoclave and

brings the whole thing 45 hours at 16 ° C in a glass bottle with a stirrer and a jacket

for the flow of thermostat fluid provided 60 stored. When polymerizing 100 g of butadiene,

is. Immediately thereafter, 100 g of technical as described in Example 1, a conversion to

Butadiene introduced. The whole is obtained for 3 hours. Polymers of 66.0% (infrared analysis:

stirred while the internal temperature was at 16 ° C. trans-1,4 = 2.9%: trans-1,2 = 2.5%; cis-1.4

will hold. The autoclave is then opened and = 94.6%).

a viscous polybutadiene solution is taken out; the 65 example 3

Polymer is then precipitated with 500 ml of methanol ^e

and in a drying cabinet at 50 ° C. under a catalyst solution stabilized with butadiene

Vacuum dried. can be stored for a particularly long time if they are with

Claims (3)

5 6 is kept at a low temperature. If diolefins are suitable and they work together to create a solution as described in Example 1 for compounds of the general formula, in the manner described there, AlR2X, in which R is an alkyl, aryl or alkylbilized and then in a dark glass bottle in the aryl radical and X means halogen, is stored with connections dark at 6 to 80C for 192 hours, 5 gene of the general formula MY2, in which Y a weden in the polymer anion described in Example 1 and M a metal of the VIII. group of the sation 98 g of dry polymer with the following proper Periodic Table of the Elements means, have been obtained, characterized in that the catalyst formed or the individual catalyst components with a molecular weight of 400,000 10 are determined viscometrically, during the infrared analysis Catalyst formation adds a diolefin. trans-1 4 3 2% ^ - Process according to claim 1, characterized in that trans-12 38% is characterized in that the diolefin 1,3 butadiene is cis-14 ............. .. 933% turns. '' 15 3. The method according to claims 1 and 2; as a result of this, that m £ "i is the diolefin in 1. Process for stabilizing catalysts used for the polymerization of conjugated Catalyst present metal of the VIIII. Group of the Periodic Table of the Elements.