DE1121813B - Process for the polymerization of conjugated diolefins - Google Patents

Description

It has long been known as catalysts for the polymerization of conjugated diolefins alkali or To use alkaline earth metals and their alloys or mixtures. Particular importance comes lithium-containing catalysts because they allow the production of predominantly linear polydiolefins, whose monomer units are largely linked in a 1,4-arrangement.

The polymerization of conjugated diolefins with alkali or alkaline earth metals as well as their Alloys or mixtures have the disadvantage that the polymerization only takes place after a latency period begins, the duration of which depends very much on factors that are difficult to overlook or reproducible. In addition, the polymerization usually proceeds so rapidly that controlled heat dissipation is only possible difficult to do. Therefore, polymers of inferior quality are often obtained. The technical The practicability of this method is therefore associated with considerable difficulties.

It has now been found that the polymerization of conjugated diolefins alone or in the Carry out mixture with monoolefins in a simple manner while avoiding the difficulties mentioned above if one is used as catalysts reaction products of alloys of lithium and alkaline earth metals and / or metals of III. Group of the Periodic Table of the Elements with compounds those elements belonging to the major periods of groups IVa, Va, VIa and VIII of the periodic table belong, as well as manganese, optionally in the presence of halogenated hydrocarbons, used.

For the preparation of the catalysts to be used according to the invention, for the at this point No protection is desired, an alloy component containing lithium is required on the one hand. It for this purpose alloys made of lithium and alkaline earth metals, such as beryllium, magnesium, calcium, Strontium, barium, as well as alloys of lithium with the metals of the III. Periodic group Systems of elements such as aluminum, gallium, indium, tallium, or the rare metals Earth in consideration. In addition to lithium, these alloys can be one or more metals the aforementioned groups included at the same time. The quantity ratio of the alloy partners is here capable of great variations. The proportion of lithium can be in a weight ratio of 1:99 to 99: 1 lie.

Some alloys are listed below by way of example, the alloy partners using the ver process for polymerisation
of conjugated diolefins

Applicant:

Paint factories Bayer Aktiengesellschaft,
Leverkusen-Bayerwerk

Dr. Josef Witte, Cologne-Stammheim,

Dr. Gottfried Pampus, Leverkusen-Schlebusch,

and Dr. Heinz Gröne, Leverkusen,

have been named as inventors

can represent a wide range of proportions: Li / Ca, Li / Mg, Li / Be, Li / Al, Li / Mg / Ca, Li / Ca / Al. Particularly It is advantageous that the alloys are extremely brittle in many cases. You can therefore z. B. Use a vibrating mill to grind easily down to a very small particle size. In contrast to lithium can only be dispersed sufficiently finely in the molten state, taking special precautions. A particle size that is as small and uniform as possible, however, is essential for the production of the catalyst and therefore also essential for its effectiveness.

Suitable compounds of those elements that belong to the major periods of groups IVa, Va, VIa and VIII of the Periodic Table of the Elements, as well as of manganese, and which can be converted to catalysts with the aforementioned lithium-containing alloys, are, for example, compounds of the transition elements, such as titanium , Zirconium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel. Compounds that may be mentioned are the halides, such as chlorides, bromides, iodides in various valency levels, the oxyhalides, rhodanides, and also nitrosyl halides, etc. Examples include: TiCl ₃ , ZrOCl ₂ , TiCl ₄ , VOCl ₃ , ZrCl ₄ , CrO ₂ Cl ₂ , CrCl ₃ , the halides of molybdenum and tungsten, MnCl ₃ , FeCl ₃ , CoCl ₂ , Co (NO) Cl, CoBr ₂ , NiJ ₂ . Compounds of the type mentioned above can expediently in the presence of tert. Amines such as B. pyridine, quinoline and the like., Can be used. Suitable halogenated hydrocarbons for the purposes of the present invention are

109 759/445

3 4

Saturated or unsaturated mono- or polyhalogen, of course, mixtures of these can also be used Polymerize compounds of the aliphatic series of straight-chain unsaturated hydrocarbons. the or branched nature, such as ethyl bromide, n-propyl catalysts mentioned above are suitable bromide, isopropyl bromide, n-butyl chloride, isoamyl also for the copolymerization of conjubromide, Amyl iodide, stearyl chloride, vinyl chloride, allyl- 5 alloyed diolefins with other monoolefins, dichloride, 1,4-dibromobutane, also cycloaliphatic, for example vinyl compounds, such as styrene, styrene representatives such as cyclohexyl chloride, as well as araliphatic derivatives, esters of acrylic acid or methacrylic acid, Halides such as benzyl bromide, benzal chloride and allyl esters, acrylonitrile, and also aliphatic monoaromatic ones Mono- and polyhalogen compounds, olefinic hydrocarbons such as ethylene, Prowie Bromobenzene, chlorobenzene, 1,4-dibromobenzene, io pylene, butylene, and also polyolefinically unsaturated 1-bromonaphthalene. Hydrocarbons such as vinylbenzene, trivinylbenzene,

To produce the catalysts, per triallyl cyanurate.

Part by weight of lithium alloy 1.0 to 0.01 by weight. The catalyst concentration is preferably so

parts of a compound or mixture so adjusted that about 0.001 to 1.0 parts by weight

Compounds of the transition lithium defined in more detail above are present per 100 parts by weight of monomer

elements used. are.

The polymerization is carried out advantageously in the presence of halogenated hydrocarbons

worked, so per halogen atom of the to be excluded with the exclusion of atmospheric oxygen and moisture

turning halogenated hydrocarbon at least in an inert atmosphere such as nitrogen or noble

2 lithium atoms or 1 atom of a metal of the II. Main ao gases, z. B. helium, argon or hydrocarbons

group or 0.6 atoms of a metal of III. Main substance steaming through. You can do the polymerization in

group exist. Make block as well as in solution. Suitable solution

The representation of the catalysts is preferred means and diluents are for example

wise in an inert solvent such as aliphatic saturated aliphatic hydrocarbons such as propane,

or aromatic hydrocarbons. 35 butane, pentane, hexane and mixtures thereof

Suitable solvents and diluents are hydrocarbons such as petroleum ether. For the same

For example, saturated aliphatic hydrocarbons can also be used. Kerosene, diesel oil,

materials such as propane, butane, pentane, hexane and paraffin oil and cycloaliphatic hydrocarbons

mix such hydrocarbons, e.g. B. petroleum ether. such as cyclohexane and aromatic hydrocarbons

For the same purpose, benzene, toluene, xylenes or mixtures thereof can also be used. the

Kerosene (a coal reaction temperature boiling at 175 to 288 ^{° C. is expediently not}

hydrogen mixture), diesel oil, paraffin oil and cyclo- higher than 90 ° C or is preferably -5 to 60 ° C.

aliphatic hydrocarbons such as cyclohexane and The pressure ratios are for the course of the

aromatic hydrocarbons such as benzene, toluene, polymerization not critical. At atmo-

Xylenes or their mixtures. The temperatures at 35 spherical pressure, but also at reduced or increased

the preparation of the catalysts depend on the pressures work. It is advantageous to leave the

the reactivity of the components. Generally polymerization will proceed at pressures as required

is at temperatures from -30 to + 120 ⁰ C, the vapor pressures of the monomers used and preferred

wise 0 to 100 ° C, worked. The effectiveness of the solvents at the applied reaction temperatures

Catalysts can be given by the nature of the assemblies.

Setting and changing the reaction conditions in After the end of the polymerization, the

can be varied within wide limits. Polymer, if no solvent is used

According to a preferred embodiment, as a solid mass or in the case of application Preparation of the catalyst is the finely divided of a solvent obtained as a viscous solution. Lithium alloy in a nitrogen or noble gas 45 In the latter case, the polymer lets through atmosphere in an inert solvent with treatment with lower alcohols such as ethanol, suitable connection of a transition element to methanol, also acetone or alcohol-water set. You can of course also first precipitate and acetone-water mixtures. In very the implementation of lithium alloy with a lot of cases, depending on the type of applied To make halogenated hydrocarbons and then a procedure, it may be appropriate to use the solution Connection of a transition element of the said polymer prior to work-up on one Add groups of the periodic table. Adjust to an almost neutral pH value. Depending on In special cases, however, it can also be advantageous to determine the type or concentration of the catalyst used During the preparation of the catalyst the addition of the can consequently involve an addition of acids or Components in a different order pre-acidic compounds, for example inorganic compounds gain weight. Acids such as sulfuric acid, phosphoric acid, or

Effective catalysts for the purposes of the present organic compounds, such as acetic acid, stearin invention are still obtained when acid, isomerized abietic acid, or alkaline the preparation of the catalyst, as described above compounds, such as inorganic bases, such as soda, but also in the presence of a 60 lye, potassium hydroxide solution, alkali carbonates, or organic Vinyl compound or divinyl compound, such as buta bases, such as amines, especially alkanolamines, diene, isoprene, styrene, vinylcyclohexene, or make necessary. With this kind of work-up Presence of the monomers to be reacted makes. the catalyst residues are deactivated at the same time

The catalysts of the invention are before and removed. When working up it is necessary in

used for the polymerization of conjugated diolefins, 65 presence of stabilizers and antioxidants,

especially those of the butadiene series, such as butadiene, such as phenyl / 3-naphthylamine, N, N'-diphenyl-p-pheny-

2-methylbutadiene, 2,3-dimethylbutadiene, 2-ethyl-lenediamine, di-tert-butyl-p-cresol, di-tert-butyl-hy-

butadiene, 2-phenylbutadiene, 2-chlorobutadiene, are suitable. droquinone, tris (nonylphenyl) phosphite, to work,

in order to avoid oxidation of the sensitive polymers and thus their premature degradation. It is however, it is also possible, immediately after the end of the polymerization, to add substances which the Deactivate catalyst, e.g. B. organic acids, then incorporate stabilizers and antioxidants and in a suitable apparatus, e.g. B. a kneader or a screw, the solvent to remove. Process the drying of the stabilized poly properties, i.e. H. for example with the addition common fillers, pigments, stabilizers and anti-aging agents vulcanize. A special The isoprene polymers produced in this way are of technical importance and are known in the art Wise can be processed into vulcanizates, which the advantageous properties of natural rubber, in particular low hysteresis as well as high elasticity and tensile strength with a low degree of hardness

merization products can exhibit io in air or in a vacuum. The vulcanizates of the poly-

at normal or elevated temperatures at 50, carried out, preferably up to 100 ⁰ C.

The polymerization of butadiene hydrocarbons with the aid of the catalysts described can be carried out discontinuously and continuously. For the discontinuous execution Bottles, stirred vessels and autoclaves are suitable, where there is the possibility of taking inert conditions to work. A screw has proven itself for continuous implementation, it has proven to be useful to connect a prepolymerization vessel upstream of the screw, in order to keep the residence time in the actual screw body as low as possible.

The copolymerization of diolefin mixtures such as butadiene-2-methylbutadiene and of diolefins with vinyl compounds such as butadiene-styrene, isoprene-methacrylic acid methyl ester, Butadiene-acrylonitrile can be made in the same way.

In contrast to the known processes, when the catalysts according to the invention are used, no or only very short latency times occur. Another essential advantage of the catalysts described here is that the polymerization takes place evenly, even in the case of relatively large batches, that is to say in an easily controllable manner and can be mastered without any particular technical effort. The polymers prepared by the present process with the catalysts to be used according to the invention generally have molecular weights which are in a favorable range with regard to the preparation of the polymers and also with regard to the processing and technological properties. So it is z. B. easily possible to produce polymers with intrinsic viscosities (η), which are in the technically particularly highly interesting range of about 4 to 8, to represent. These polymers contain practically no gel content. In contrast, lithium metal catalysts produce polymers with much higher molecular weights. The production of such polymers is very difficult to control because of the high viscosity values, unless one works in very dilute solutions, in which case a reduced space-time yield has to be accepted.

The possibility of using nitrogen also brings considerable technical progress as an inert gas during polymerization compared to the use of noble gases when using metallic ones Lithium with it. The risk of a drop in molecular weights if the Catalysts is also significantly reduced, since the maximum concentration of them is nowhere near is as critical as with the previously known organic alkali metal catalysts.

The polymers obtained by the process described can be prepared by the customary methods to elastic products with good technological butadienes show a low with high elasticity Abrasion, which suggests the use of these polymers in tread mixtures for motor vehicle tires.

The parts listed below are parts by weight, unless otherwise stated.

example 1

1.52 parts of an alloy with 65 percent by weight of aluminum and 35 percent by weight of lithium, which was finely ground in a vibrating mill, are suspended in 30 parts of benzene and admixed with 1.08 parts of vanadium oxychloride. The mixture is stirred at 7O ⁰ C until the immediately resulting yellow color disappeared.

To 200 parts of isoprene, which was purified by distillation over sodium in the presence of triethyl aluminum, is added 16 parts of the deep-sch warzgefärbten catalyst suspension and heated with stirring to 40 ⁰ C. The polymerization starts after 10 to 15 minutes and is complete after 4 hours .

The product is mixed with 400 parts of hexane, 40 parts of methanol and 15 parts of acetic acid in a kneader, washed with water and dried. Yield: 180 parts of polyisoprene, (η) = 7.8. Gel content below 5 ° / ₀ , 1,4-cis linkage 93 ° / ₀ .

Example 2

14 parts of an alloy with 22 percent by weight lithium and 78 percent by weight calcium are added together with 80 parts of benzene and 7 parts of crystallized violet titanium trichloride in a vibrating mill. After grinding the mixture, a fine blue-black suspension is obtained.

7.5 parts of the catalyst are added to a mixture of 250 parts of hexane and 100 parts of isoprene, which was purified as in Example 1, and the mixture is heated to 40 ^° C .; the polymerization has clearly started after 40 minutes, proceeds uniformly and is complete after 6 to 7 hours.

The resulting product is treated in a kneader with 100 parts of 50 ° / ₀ methanol and 5 parts of ethylene diamine tetraacetic acid, washed with water and dried. This gives 92 parts of polyisoprene (η) = 5.8, a gel content below 5% - The monomer units are linked to 94 ° / ₀ in 1,4-cis position.

Example 3

1.6 parts of an alloy with 65 percent by weight of aluminum and 35 percent by weight of lithium, which was finely ground in a vibrating mill, are suspended in 30 parts of benzene and 10 parts of vinylcyclohexene. A mixture of 4 parts of benzene and 1.12 parts of vanadium oxychloride is added at 70 ^{° C. with stirring.} The mixture is stirred for a further 1 hour at 70 ^° C. and a deep purple colored suspension is obtained.

To polymerize 200 parts of isoprene, 19 parts of catalyst suspension are used and

continues as in Example 1. The polymerization begins after a few minutes and is over after 6 hours. Working up as in Example 1 gives 192 parts of polyisoprene with (η) = 6.4, a gel content of less than 5% and a linkage in the 1,4-cis position of 96 ° / _e .

Example 4

2.4 parts of an alloy of 47 ° / ₀ and 53% lithium aluminum are stirred in 24 parts of benzene with 0.83 parts of cobalt (IT) chloride and 1.02 parts of pyridine for 15 minutes at 6O ⁰ C.

The so prepared catalyst is heated with 150 parts Petroläthei (boiling range 30 to 75 ⁰ C) and 100 parts of butadiene in an autoclave with stirring to 70 ⁰ C. The polymerization has ended after 1 hour. Working up is carried out by kneading the reaction mixture with a mixture of 50 parts of methanol and 15 parts of acetic acid. After careful washing with water, it is dried. Yield: ao 90 parts, (η) = 1.4. 1,4 linkage: 75 ° / ₀ . Gel free.

Example 5

2 parts of a finely ground alloy of 35 ° / o lithium and 65% aluminum are heated with 0.7 parts as cobalt (II) chloride and 0.43 parts of pyridine in 24 parts of benzene 30 minutes with stirring at 6O ⁰ C.

The so prepared catalyst is heated to 70 ⁰ C together with 150 parts of petroleum (boiling range 30 to 75 ° C) and 100 parts of butadiene in the autoclave with stirring. The polymerization is over after 3 hours. Work-up is carried out as described in Example 4. Yield: 94 parts, (η) = - ■ 3.81. 1,4 linkage: 80%. Gel free.

Example 6

2 parts of a finely ground alloy of 21 ° / o lithium and 79% calcium are stirred in 24 parts of benzene with 0.7 parts of nickel (II) chloride and 0.43 parts of pyridine for 30 minutes at 6O ⁰ C under argon. The so prepared catalyst is heated in a stirred autoclave at 70 ⁰ C with 150 parts of petroleum ether and 100 parts of butadiene. After 3.5 hours, as described in Example 4, worked up. A gel-free polybutadiene is obtained. Yield: 89 parts, (η) = 1.51.1,4 linkage: 75%.

Example 7

2 parts of a finely ground alloy of 35% lithium and 65% aluminum grazing under argon with 0.7 parts of nickel (II> chloride and 0.43 parts of pyridine were added in 24 parts of benzene and heated for 30 minutes at 6O ⁰ C with stirring.

This catalyst suspension is heated to 70 ° C. in a stirred autoclave together with 150 parts of petroleum ether (boiling point 30 to 75 ° C.) and 100 parts of butadiene. The polymerization has ended after 4 hours. Working up as described in Example 4 gives a gel-free polymer. Yield: 99 parts, (η) = 3.3. 1,4 linkage: 75%.

Example 8

2 parts of a finely ground alloy of 35% lithium and 65% aluminum are mixed under argon with 0.7 parts of chromium (III) chloride and 0.35 parts of pyridine and stirred for 30 minutes at 6O ⁰ C.

The catalyst suspension is heated with 150 parts of petroleum (boiling range 30 to 75 ⁰ C) and 100 parts of butadiene in a stirred autoclave at 70 ⁰ C. After a reaction time of 4 hours, work-up is carried out as described in Example 4. The polymer contains about 10% gel. Yield: 92 parts, {rj) = 6.25.

Example 9

1.74 parts of a finely divided alloy of 21% lithium and 79% calcium are mixed under argon 1.81 parts of n-butyl chloride in 24 parts of benzene were stirred at 70 ° C. for 30 minutes. After cooling to room temperature 0.46 parts of zirconium tetrachloride are added. The mixture is then stirred at 70 ° C. for a further 1.5 hours.

The catalyst prepared in this way is heated to 70 to 80 ° C. in a stirred autoclave with 150 parts of petroleum ether and 100 parts of butadiene. The polymerization has ended after 10 hours. Work-up is carried out as described in Example 4. Yield: 90 TeUe. (η) = 5.7.

Example 10

2.2 parts of a finely ground alloy of 35% lithium and 65% aluminum are mixed with 0.9 parts of dicyclopentadienyl nickel in 30 parts of benzene. The mixture is heated in an argon atmosphere with stirring for 30 minutes 7O ⁰ C. The catalyst suspension is placed in a stirred autoclave and 200 parts of petroleum ether (boiling point 30 to 75 ° C.), 100 parts of butadiene and 15 parts of 1-hexene are added. The polymerization is carried out at 8O ⁰ C and ends after 6 hours. Working up as in Example 4, a gel-free polymer is obtained. Yield: 108 parts, η = 2.4. 1,4 linkage: 72%.

Example 11

1.95 parts of a finely powdered lithium aluminum alloy (27% Li, 73% Al) be the exclusion of air with 1.6 parts of n-butyl chloride in 30 parts of benzene for 60 minutes at 7O ⁰ C stirred. After cooling, 250 parts of cyclohexane and 1.1 parts of titanium tetraiodide are added. The catalyst suspension is stirred at 30 to 35 ° C. for 2 hours. 100 parts of butadiene are then added. The polymerization begins after a short time and is terminated after 7 hours. The viscous solution is worked up as described in Example 4. 63 parts of a tough, rubber-like product are obtained. 1,4 linkage: 92%. η = 2.7.

Claims (4)

PATENT CLAIMS: 1. Process for the polymerization of conjugated diolefins, optionally with others olefinically unsaturated monomers, in bulk or in solution in the presence of lithium-containing Catalysts, characterized in that a catalyst is used which is produced by reaction of alloys of lithium and alkaline earth metals and / or metals of III. Group of Periodic table with compounds of such elements that correspond to the great periods of the Giuppen IVa, Va, VIa and VIII belong to the periodic table, as well as from manganese. 2. The method according to claim 1, characterized in that that one uses a catalyst in the presence of halogenated hydrocarbons has been made. 9 ίο 3. Method according to claim 1 and 2, characterized in IVa, Va, VIa and VIII of the periodic table characterized in that one includes a catalyst, as well as manganese, halides and / or applies, which uses in the presence of olefinically non-oxyhalides of the transition elements, saturated monomers has been produced. 4. The method according to claim 1 to 3, characterized ge 5 indicates that such publications under consideration are compounds: Elements belonging to the major periods of the groups U.S.A. Patent No. 2,908,672. 109 759/445 1.62