DE1267849B - Process for the production of polymers of conjugated diolefins - Google Patents

Description

Process for the production of polymers of conjugated diolefins The invention relates to a process for the production of polymers of conjugated diolefins, which are practically gel-free and have a high cis-1,4-addition content, by polymerizing the conjugated diolefins in the presence of a catalyst made from a) metallic cobalt, Cobalt compounds, cobalt complex compounds, a material which is formed in the electrodeposition of metallic cobalt on metallic zinc, metallic nickel, nickel compounds, nickel complex compounds, or a material which is formed in the electrochemical deposition of metallic nickel on metallic zinc, and b) an organic aluminum compound, which is characterized in that the polymerization is carried out in the presence of a thiodipropionic acid ester of the general formula: in which R1 and R2 represent identical or different alkyl groups with 8 to 20 carbon atoms.

It is known that catalysts made from compounds of transition metals and organometallic compounds for preparing conjugated cis-1,4-addition polymers To apply diolefins. It is also known that especially in the education from cis-1,4-polybutadiene from 1,3-butadiene catalysts from nickel or cobalt compounds and organic aluminum compounds have proven useful.

However, such catalyst systems have transition metal and organometallic compounds has such a low polymerization activity that it is used in the production of cis-1,4-polymers made of conjugated diolefins must be used in large quantities, with the result has that the polymers obtained contain large amounts of residual catalyst.

In addition, these catalyst systems favor conjugate gel formation Dienolefins under polymerization conditions, so that conjugated during the polymerization Diolefins in the presence of such catalysts hardly any polymers with a low gel content can be obtained.

Numerous proposals have been made to address these difficulties to bypass. Some examples of this are the addition of amines, pyridine, nitriles, Amides, ethers, boron halides and the like are conjugated to the polymerization systems Diolefins.

However, none of these methods address the disadvantages of the specified Fix Kytalysatorsysteme in a completely satisfactory manner, since still large Amounts of catalyst are necessary and polymers with a fairly large gel content and sometimes brown in color.

The invention relates to a new process for the polymerization of conjugates Diolefins, with which the described disadvantages of the catalyst systems in very satisfactorily resolved and conjugated, practically uncolored, transparent and practically gel-free diolefin polymers with high cis-1,4 addition contents in high Yields are formed when using small amounts of catalyst. This is according to the invention by the presence of a thiodipropionic acid diester in the polymerization system during the polymerization of a conjugated diolefin in the presence of a catalyst made of metallic cobalt or nickel, their compounds or complex compounds or from a material that is used in the electrodeposition of metallic Cobalt or metallic nickel is formed on metallic zinc, and an organic one Aluminum connection achieved.

The thiodipropionic diesters can be used individually or as a mixture with one another to be used. Dilauryl 3,3'- and distearyl 3,3'-thiodipropionate are preferred.

The amount in which the thiodipropionic diesters are used preferably moves in the area from 0.01 to 10 mM per 100 g conjugated diolefin.

The optimal amount of diester depends on the type of catalyst used and the polymerization conditions (such as monomer concentration, catalyst concentration and polymerization temperature) from; it is usually in the range of 0.1 to 1.0 mM per 100 g conjugated diolefin.

Due to the presence of a thiodipropionic acid diester in the polymerization system of conjugated diolefins, the polymerization activity of the polymerization catalyst extraordinarily increased. For example, by adding the diester to the Polymerization system the amount of the catalyst and especially the costly one organic aluminum compound to one fifth to one fiftieth or less reduce the amount required without such an addition. So also takes the amount of residual catalyst in the polymer obtained greatly decreases and even if the residual catalyst is not removed from the polymer by extraction, the ash content of the Polymers can be reduced to about 0.1-0.2%.

For example, thiodipropionic diester is used in the polymerization system not added, then the polymerization yield exceeds after a polymerization time of 1 hour not 80 ° / 0, unless you apply more than about 15 mM organic Aluminum compound on 100 g conjugated diolefin.

In contrast, the polymerization system 0.01 to 10 mM diester per 100 g conjugated diolefin added, is achieved after a polymerization time of 1 hour with only 0.5 to 10 mM organic aluminum compound per 100 g conjugated Diolefin a polymerization yield of more than 80%. The amount of Cobalt or nickel compound or complex compound is preferably in the range from 0.01 to 1.0 mM per 100 g of conjugated diolefin, and the amount of metallic Cobalt or metallic nickel preferably in the range from 0.02 to 1.0 g per 100 g conjugated diolefin and that in the electrochemical deposition of metallic Material formed from cobalt or metallic nickel on metallic zinc is expedient in the range of 0.03 to 1.0 grams per 100 grams of conjugated diolefin.

Because the thiodipropionic diester has an excellent inhibitory effect exert on gel formation, one can use them in the polymerization systems of practically eliminate the formation of gel with conjugated diolefins.

The presence of these diesters in the polymerization systems is conjugated Diolefins created in polymers that are transparent and only light colored but otherwise similar to the polymers obtained without the diesters, no stains. (If amines are added in accordance with normal practice, they will turn brownish in color Polymers obtained.) The only slightly colored transparent polymers can color as desired and as a result have a wide range of uses.

The type of thiodipropion diester addition is not subject to any restriction, all known methods are possible if they achieve that the diester present in the reaction system during the polymerization of conjugated diene olefins is. For example, the diesters can previously be in the solvent for the polymerization be included, they can be added simultaneously with or after the catalyst or with the conjugated diolefin monomer into the Mixture are introduced. Intended to the catalyst must be aged before being used in the polymerization reaction the diester is expediently added after the catalyst has aged.

Metallic cobalt or metallic nickel - a component of the catalyst used according to the invention - is not limited to the simple substance it can also contain Raney cobalt or Raney nickel or one containing cobalt or nickel Alloy can be used. Suitable cobalt or nickel compounds are the halides, in particular the chloride, furthermore the nitrosyl halide, the octoate and naphthenate.

This is a suitable complex compound of cobalt or nickel Cobalt or nickel acetylacetonate.

This is the case with the electrochemical deposition of metallic cobalt or metallic nickel on metallic zinc formed material recently is manufactured in the following way: Metallic zinc powder is in an aqueous solution of a water-soluble cobalt or nickel salt (e.g.

Halide or mineral acid salt) at a temperature of at most 50 "C given and the solution was stirred interrupted until it became metallic Cobalt or metallic nickel due to the difference in normal potential between Electrochemically deposited zinc and cobalt or nickel on metallic zinc. The precipitate obtained in this way is filtered off, washed with water and dried.

As organic aluminum compounds, - the other component of the Catalyst used according to the invention - have compounds of the general Formula A1RnX3-n, in which R is an alkyl, cycloalkyl or phenyl group, X is a halogen and n represents a number from 1 to 3 including decimals, the individual or can be used in a mixture with one another, proven to be expedient. Some Particularly suitable examples are monoethyl aluminum dichloride, diethyl aluminum monochloride, Triethyl aluminum, as well as diisobutyl aluminum, diphenyl aluminum and dicyclohexyl aluminum monochloride.

Even when using a Lewis acid or Lewis base in combination with the catalyst components specified above, the effect described is achieved achieved to the same extent when the diester is added to the polymerization system.

The catalyst can be used immediately after mixing the two Components for the polymerization of conjugated diolefins in an inert solvent to be used. However, its polymerization activity is reduced by aging given conditions before being brought into contact with the conjugated diolefins will increase greatly. A suitable aging process is to use both catalyst components put in an inert solvent and put them together for 30 to 120 minutes on one Temperature in the range from 10 to 100 ° C. or slightly above the polymerization temperature to keep. The polymerization activity of the so aged catalysts is reached five to seven times greater values than the unaged catalytic converters.

Some examples of the conjugates to be used in the present invention Diolefins are 1,3-butadiene, isoprene and 2-methyl-1,3-pentadiene. These conjugated Diolefins can either be polymerized individually or in a mixture copoly with each other or together with other unsaturated hydrocarbons. be merized.

For the polymerization of the conjugated dienes and for aging of the catalysts, various inert solvents can be used, but preferably the same solvent is used. Some examples are aromatic, saturated aliphatic and alicyclic hydrocarbons and their Derivatives (especially the halogen substitution products). In practice, for example Benzene, toluene and monochlorobenzene are preferred.

The appropriate concentrations of the conjugated diolefin monomers in the inert solvent prior to the polymerization range from 5 to 30 Weight percent.

The suitable polymerization temperature is between -20 and +80, preferably between +5 and +50 "C. The polymerization can take place at atmospheric pressure or increased pressure.

The polymerization system is needed to complete the polymerization reaction adding only a small amount of a substance that inactivates the catalyst, z. B. water, alcohol, acetone, acetic acid or ether. At this point the Addition of an antioxidant of a known type to the conjugated diolefin polymer recommendable. When pouring the solution after the completion of the polymerization of the conjugated - diolefin by adding a small amount of a substance to Inactivation of the catalyst is obtained, in a large amount of alcohol, e.g. B. Methanol, the conjugated diolefin polymer coagulates. After separation and Vacuum drying of the solid substance obtained gives a rubber-like conjugate Diolefin polymer.

In the examples which illustrate the process, was the microstructure of the conjugated diolefin polymers according to the method of R. R.

H a m p t o n based on the IR absorption spectra (Analytical Chemistry, 21, p. 923 [1949]).

The intrinsic viscosity [g] of the diolefin polymers was based on the viscosity in toluene at 26 ° C - determined with the Ostwald viscometer - calculated.

The gel content in the diolefin polymer was determined in the following way: 0.15 g of dry polymer was placed in a container made of stainless steel gauze with 100 openings per square centimeter and a capacity of 11.5 cm8 given, together with the container immersed in 100 cm3 benzene, in a dark place Left to stand for 48 hours at 25 ° C, then removed the container that is inside retarded Gel dried in vacuo and weighed. The weight percent of insoluble polymer (i.e. gel) based on the total amount of polymer was used as the gel content of each Called polymers.

Example 1 A reaction vessel with a capacity of 1501, which can be filled with equipped with a stirrer and jacket for circulation cooling, was dried and after the air it contains has been completely displaced by nitrogen 98 1 of a solution mixture of benzene and 1,3-butadiene (102 g 1,3-butadiene per liter Solution mixture) introduced into the container.

Thereafter, 1 l of a solution of diethylaluminum monochloride was first added in benzene [0.3 mol Al (C2Hs) aCl per liter of solution] and then 1 1 of a solution of Cobalt octoate and dilauryl 3,3-thiodipropionate in benzene (0.004 mol cobalt octoate and 0.025 mol of dilauryl 3,3'-thiodipropionate per liter of solution). The polymerization was carried out for 1 hour at 10 ° C. with constant stirring.

The reaction was ended by adding a small amount of methanol, added 2 l of a 50/0 benzene solution of phenyl-p-naphthylamine (antioxidant) and gave the reaction mixture in 250 l of methanol. The coagulated polymer separated you washed it off with water and dried it at 900 C.

The yield of the cis-1,4-polybutadiene thus obtained was 85O / o. The product had the following properties: Basic molar viscosity number [11] T6olCol 3.0 cis-1,4 addition content .................................... 98.2% Gel content .................................................. 0% Examples 2 to 6 Among the in Example 1 specified conditions was polymerized 1,3-butadiene, but the Amounts of dilauryl 3,3'-thiodipropionate, cobalt octoate and diethyl aluminum monochloride as well as the monomer concentration varies. The results are summarized in Table 1, in which the amounts of cobalt octoate (CoOct), diethylaluminum monochloride (AlÄthCl) and dilauryl thiodipropionate (DLS) are converted to values per 100 g of 1,3-butadiene.

Under Comparative Example 1 are those in the absence of dilauryl-3,3'-thiodipropionate results obtained. A comparison of the values of this example 1 with that of Examples 2 to 6 shows that you can use a fairly large amount of diethylaluminum monochloride must use in order to achieve the same yield as in the examples according to the invention achieve without the gel formation can be prevented.

Table 1 Monomeric CoOct AlÄth2Cl DLS Yield cis-1,4-content Gelage content concentration [#] toluene 26 ° C (mM) (mM) (mM) (%) (%) (%) (%) Example 2 0.04 2.5 0.25 15 85 98.2 3.2 0 Example 3 0.04 1.5 0.25 20 85 98.2 3.5 0 Example 4 0.04 10.0 0.10 12 85 98.1 3.1 0 Example 5 0.04 5.0 0.15 12 85 98.1 3.1 0 Example 6 0.04 3.0 0.20 12 85 98.2 3.1 0 Comparative example 0.04 20.0 0 - 12 85 97.8 3.1 5 Examples 7 and 8 Under the conditions given in Example 1, 1,3-butadiene was polymerized, but cobalt naphthenate (CoNaph) was used instead of cobalt octoate as the cobalt compound. The results are compiled in Table 2, in which the amounts of catalyst and dilauryl 3,3'-thiodipropionate are converted to values per 100 g of 1,3-butadiene.

Table 2 Monomers = CoNaph AlAth2Cl DLS yield cis-1,4-content gel content concentration [#] toluene 26 ° C (mM) (mM) (mM) (%) (%) (%) (%) Example 7 0.04 2.8 0.25 12 85 98.0 2.6 0 Example 8 0.04 2.3 0.25 15 85 98.1 2.8 0 Examples 9 to 12 1,3-Butadiene was polymerized under the conditions of Example 1, but the dilauryl 3,3'-thiodipropionate was replaced by distearyl 3,3'-thiodipropionate (hereinafter referred to as DSS) and both the amounts of diethylaluminum monochloride as well as that of catalyst varies. The results are compiled in Table 3, in which the amounts of catalyst and of DSS are given in values per 100 g of 1,3-butadiene.

Table 3 Monomeric CoOct AlÄth2Cl DSS yield cis-1,4-content gel content concentration [#] toluene 26 ° C (mM) (mM) (mM) (%) (%) (%) (%) Example 9 0.04 10.0 0.10 12 85 98.0 3.0 0 Example 10 0.04 5.0 0.15 12 85 98.1 3.0 0 Example 11 0.14 3.0 0.20 12 85 98.0 3.1 0 Example 12 0.04 2.5 0.25 12 85 98.2 3.0 0 EXAMPLE 13 1,3-Butadiene was polymerized under the conditions of Example 1, but the catalyst of Example 1 (ie cobalt octoate and diethylaluminum monochloride) by means of a catalyst composed of 7.0 g of metallic cobalt, 1.0 mol of monoethylaluminum dichloride and 0.5 mol of pyridine replaced. The result was a cis-1,4-polbutadiene with a cis-1, S addition content of 98.2%. [#] Toluene 26 ° C = 3.0, gel content 00 / o in a yield of 850 / o.

The 1,3-butadiene was made under the same conditions, but in its absence polymerized by dilauryl-3,3'-thiodipropinate, cis-1,4-polybutadiene with a cis-1,4 addition content of 97.6%, [#] toluene 26 ° C = 3.0, and a gel content of 10% obtained in 60% yield.

Example 14 1,3-butadiene was prepared under the conditions of the example 1 polymerized, but the catalyst of Example 1 through 60 g of a material (Content of metallic cobalt 150 /,) that is produced during the electrochemical deposition of metallic cobalt on metallic zinc, and 0.5 moles of diethylaluminum monochloride replaced. The result was a cis 1,4-polybutadiene with a cis 1,4 addition content of 98.2%, [#] toluene 26 ° C = 3.0 and a gel content of 0% in 85% yield.

Example 15 1,3-butadiene was prepared under the conditions of the example 14 polymerized, but the material used in it, which is used in the electrochemical Deposition of metallic cobalt on metallic zinc had been obtained by 60 g of a material (content of metallic nickel: 15%) replaced by the obtained electrochemical deposition of metallic nickel on metallic zinc had been. The result was a cis 1,4-polybutadiene with a cis 1,4 addition content of 98.2 0 / o, [#] toluene 26 ° C = 3.0 and a gel content of 00 / o in 85% yield.

Example 16 Isoprene was polymerized under the conditions of Example 1, but as a catalyst 120 g of a material (content of metallic cobalt: 15%), this is the case with the electrochemical deposition of metallic on metallic zinc was obtained, and 1.0 mole of diethylaluminum monochloride was used and the polymerization time extended to 2 hours.

The result was a polyisoprene with a 1,4-addition content of 98.0%, [#] toluene 26 ° C = 3.6 and a gel content of 0% in 60% yield.

Claims (2)

Claims: 1. Process for the production of polymers of conjugated diolefins by polymerizing the conjugated diolefins in the presence of a catalyst from a) metallic cobalt, cobalt compounds, cobalt complex compounds, a material that is formed during the electrochemical deposition of metallic cobalt on metallic zinc, metallic nickel, Nickel compounds, nickel complex compounds or a material which is formed during the electrochemical deposition of metallic nickel on metallic zinc, and b) an organic aluminum compound, characterized in that the polymerization is carried out in the presence of a thiodipropionic diester of the general formula: in which R1 and R2 represent identical or different alkyl groups with 8 to 20 carbon atoms. 2. The method according to claim 1, characterized in that the Thiodipropionic diester in an amount of 0.01 to 10 mM, preferably 0.1 to Apply 1.0 mM per 100 g conjugated diolefin.