EP1056791A1

EP1056791A1 - Method for the production of polydienes with regulated mooney viscosity

Info

Publication number: EP1056791A1
Application number: EP99908857A
Authority: EP
Inventors: Gerd Sylvester; Günter MARWEDE
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1998-02-19
Filing date: 1999-02-06
Publication date: 2000-12-06
Also published as: CA2320886A1; US6344527B1; AU2832199A; DE19806931A1; JP2002504574A; WO1999042503A1

Abstract

The invention relates to a method for the production of polydienes with regulated Mooney viscosity using catalysts based on rare earth compounds and characterized in that the charged conjugated dienes are polymerized in the presence of 0.000 to 80 wt. % 1,2-dienes, in relation to the sum of the charged conjugated dienes and charged 1,2-dienes. The polydienes thus produced can be particularly used in the production of automobile tires.

Description

Process for the preparation of polydienes with controlled Mooney viscosity

The invention relates to a process for the preparation of polydienes with a controlled Mooney viscosity in the presence of rare earth metal catalysts and in the presence of special molecular weight regulators. The polydienes produced in this way are used in particular in the manufacture of car tires.

From EP 0 647 657 i.a. a process for the preparation of polydienes known, accordingly conjugated dienes in the gas phase with the aid of a carried

Catalyst based on rare earth compounds are polymerized.

Furthermore, EP 0 736 549 discloses a process for the preparation of diene rubbers in the gas phase, in which the dienes or

Polymerized diene mixtures in the presence of a rare earth catalyst in a special way, so that a free-flowing diene rubber with a defined Mooney viscosity is obtained, and then in a second stage the free-flowing diene rubber obtained is subjected to a degradation reaction in the usual manner until one reduced Mooney viscosity is reached. The process described in EP 0 736 549 offers the possibility of producing diene rubbers with the desired Mooney viscosities depending on the area of use, which have defined Mooney viscosities in accordance with the desired area of use.

Although the process described in EP 0 736 549 gives good results with regard to the achievable Mooney viscosities for the diene rubbers, a process-technically simpler, more economical molecular weight control would be desirable in the gas phase process. - 2 -

Such a molecular weight control can be accomplished economically and in a process-technically simple manner by the method according to the invention described in more detail below.

The present invention therefore relates to a method for producing

Polydienes with controlled Mooney viscosity by means of catalysts based on rare earth compounds, which is characterized in that the conjugated dienes used in the presence of 0.005 to 80 wt .-% of 1,2-dienes, based on the sum of conjugated dienes used and 1, 2-dienes used, polymerized.

Examples of conjugated dienes which can be used in the gas phase process according to the invention are 1,3 butadiene, isoprene, pentadiene and / or dimethyl butadiene, especially 1,3-butadiene and isoprene. Of course, it is also possible in the process according to the invention to carry out the polymerization in the presence of other monomers, such as e.g. Ethylene, propylene, butene, isobutylene, methylpentene, norbornene, cyclopentadiene, cyclohexene, styrene or chloroprene.

The amount of these monomers used can vary within wide limits. In general, the amount of additional monomers used is 0.01 to 200% by weight, based on the conjugated diene used, preferably 0.1 to 20% by weight.

The 1, 2-dienes used to control the Mooney viscosities are used in amounts of 0.005 to 80, preferably 0.01 to 30, and very particularly preferably 0.05 to 10% by weight, based on the total of the conjugates used Diene and the 1, 2-diene used.

The amount of use of the regulator according to the invention depends on various factors, for example on the amount of catalysts used, the type of monomers used, the proportion of monomers in the reaction mixture, the reaction temperature and the pressure. Appropriate preliminary tests make it easy to determine the most suitable amount of regulator for the desired Mooney viscosity of the polymer.

Suitable dienes are, in particular, those with boiling points below 140 ° C., preferably below 80 ° C., such as allen, 1, 2-butadiene, 1, 2-pentadiene, 1-vinylcyclopentene, 1-vinylcyclohexene and Vinyl acetylene, or mixtures containing such 1,2-dienes.

The amounts of 1,2-dienes to be used previously are mean values, i.e. Quantities that apply to the entire course of the reaction. This means, for example, that the regulator according to the invention can be metered in completely, continuously during the entire course of the polymerization or intermittently at the beginning of the polymerization reaction.

The process according to the invention is usually carried out at temperatures from -20 ° C. to 250 ° C., preferably 20 to 160 ° C., particularly preferably 50 to 120 ° C., and at pressures from 1 mbar to 50 bar, preferably at 0.5 to 30 bar , particularly preferably carried out at 1 to 20 bar.

As mentioned above, the process according to the invention is carried out in the presence of special supported catalysts based on rare earth compounds. In this context, we also refer to the patent literature also mentioned above, in which such catalysts are described and claimed.

The rare earth metal catalysts to be used for the process according to the invention consist, for example, of: A) an alcoholate of the rare earths (I), a carboxylate of the rare earths (II), a complex compound of the rare earths with diketones (III) and / or an addition compound of the halides of the rare earths with an oxygen or nitrogen donor compound (IV ) of the following formulas:

(RO) ₃ M (I), (R-CO ₂ ) ₃ M (II),

(RCOCHCOR) 3M (III) and MX3 ^• y donor (IV),

B) an aluminum trialkyl, a dialkylaluminium hydride and / or an aluminoxane of the formulas (V) - (VII):

A1 R ₃ (V), HA1 R ₂ (VI), R (AlO) _n AlR ₂ (VII)

being in the formulas

M is a trivalent element of the rare earths with the atomic numbers

21, 39 or 57 to 71 means

R is identical or different and denotes alkyl radicals with 1 to 10 carbon atoms,

X represents chlorine, bromine or iodine

y is 1 to 6 and

n means 1 to 50, C) a further Lewis acid and

D) an inert, particulate solid with a specific surface area greater than 10 m ² / g (BET) and a pore volume of 30 to 1,500 ml / g.

In component A, M is a trivalent element of the rare earths with the atomic numbers 21, 39 or 57 to 71 identified in the periodic table. Preferred compounds are those in which M is lanthanum, cerium, praseodymium or neodymium or a mixture of rare earth elements, which contains at least one of the elements lanthanum, cerium, praseodymium or neodymium to at least 10% by weight

% contains means. Compounds in which M is lanthanum or neodymium or a mixture of rare earths which contain at least 30% by weight of lanthanum or neodymium are very particularly preferred.

The radicals R in the formulas (I) - (IV) are in particular straight-chain or branched

Alkyl radicals with 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, isopropyl, isobutyl, tert-butyl, 2 ethylhexyl, neo-pentyl, neo -Octyl, neo-decyl and neo-dodecyl.

As alcoholates of component A e.g. called: neodymium (III) -n-propanolate,

Neodymium (III) -n-butanolate, neodymium (III) -n-decanolate, neodymium (III) -isopropanolate, neodymium (III) -2-ethyl-hexanolate, praseodymium (III) -n-propanolate, praseodymium (III ) -n-butanolate, praseodymium (III) -n-decanolate, praseodymium (III) -iso-propanolate, praseodymium (III) - 2-ethyl-hexanolate, lanthanum (III) -n-propanolate, lanthanum (III) -n-butanolate, lanthanum (III) - n-decanolate, lanthanum (III) iso-propanolate, lanthanum (III) -2-ethyl-hexanolate, preferred

Neodymium (III) n-butanolate, neodymium (III) n-decanolate, neodymium (III) -2-ethyl hexanolate.

Suitable carboxylates of component A are: lanthanum (III) propionate, lanthanum

(IΙI) diethyl acetate, lanthanum (III) -2-ethylhexanoate, lanthanum (III) stearate, lanthanum (III) benzoate, lanthanum (III) cyclohexane carboxylate, lanthanum (III) oleate, lanthanum (III) versa tat, lanthanum (III) naphthenate, praseodymium (III) propionate, praseodymium (III) diethyl acetate, - 6 -

Praseodymium (III) -2-ethylhexanoate, praseodymium (III) stearate, praseodymium (III) benzoate, praseodymium (III) cyclohexane carboxylate, praseodymium (III) oleate, praseodymium (III) verateate, praseodymium (III) -naphthenate, neodymium (III) propionate, neodymium (III) diethyl acetate, neodymium (III) -2-ethylhexanoate, neodymium (III) stearate, neodymium (III) benzoate, neodymium (III) cyclohexane carboxylate, neodymium (III) oleate, neodymium (III) versatate, neodymium (III) naphthenate, preferably neodymium (III) -2-ethylhexanoate, neodymium (III) versatate, neodymium (III) naphthenate. Neodymium versatate is particularly preferred.

The following may be mentioned as complex compounds of component A: lanthanum (III) acetyl acetonate, praseodymium (III) acetylacetonate, neodymium (III) acetylacetonate, are preferred

Neodymium (III) acetylacetonate.

Examples of addition compounds of component A with donors are: lanthanum (III) chloride with tributyl phosphate, lanthanum (III) chloride with tetrahydrofuran, lanthanum (HI) chloride with isopropanol, lanthanum (III) chloride with

Pyridine, lanthanum (III) chloride with 2-ethylhexanol, lanthanum (III) chloride with ethanol, praseodymium (III) chloride with tributyl phosphate, praseodymium (III) chloride with tetrahydrofuran, praseodymium (III) chloride with isopropanol , Praseodymium (III) chloride with pyridine, praseodymium (III) chloride with 2-ethylhexanol, praseodymium (III) chloride with ethanol, neodymium (III) chloride with tributyl phosphate, neodymium (III) chloride with tetrahydrofuran, neodymium ( III) chloride with iso-propanol, neodymium (III) chloride with pyridine, neodymium (III) chloride with 2-ethylhexanol, neodymium (III) chloride with ethanol, lanthanum (III) bromide with tributyl phosphate, lanthanum (III) bromide with tetrahydrofuran, lane than (III) bromide with isopropanol, lanthanum (III) bromide with pyridine, lanthanum (III) bromide with 2-ethylhexanol, lanthanum (III) bromide with ethanol, Praseodymium (III) bromide with tributyl phosphate, praseodymium (III) bromide with tetrahydrofuran, praseodymium (III) bromide with isopropanol, praseodymium (III) bromide with pyridine, praseodymium (III) bromide with 2-ethylhexanol, P raseodymium (III) bromide with ethanol, neodymium (III) bromide with tributyl phosphate, neodymium (III) bromide with tetrahydrofuran, neodymium (III) bromide with isopropanol, neodymium (III) bromide with pyridine, neo - dym (III) bromide with 2-ethylhexanol, neodymium (III) bromide with ethanol, preferred - 7 -

Lanthanum (III) chloride with tributyl phosphate, lanthanum (III) chloride with pyridine, lanthanum (III) chloride with 2-ethylhexanol, praseodymium (III) chloride with tributyl phosphate, praseodymium (III) chloride with 2-ethylhexanol, neodymium (III) chloride with tributyl phosphate, neodymium (III) chloride with tetrahydrofuran, neodymium (III) chloride with 2-ethylhexanol, neodymium (III) chloride with pyridine, neodymium (III) chloride with 2-ethylhexanol, Neodymium (III) chloride with ethanol.

The rare earth compounds can be used individually or as a mixture with one another.

Neodymium versatate, neodymium octanoate, the addition compound of neodymium chloride with tributyl phosphate and / or neodymnaphthenate are very particularly preferably used as component A.

In the formulas (V) to (VII) of component B, R denotes a straight-chain or branched alkyl radical having 1 to 10 C atoms, preferably 1 to 4 C atoms. Examples of suitable aluminum alkyls of the formulas (V) and (VI) are:

Trimethylaluminium, triethylaluminium, tri-n-propylaluminium, triisopropylaluminium, tri-n-butylaluminium, triisobutylaluminium, tripentylaluminium, trihexylaluminium, tricyclohexylaluminium, trioctylaluminium, diethylaluminiumhydro-nidridyl-di-alidridium-di-dridal-aluminum-di-hydride, di-butyl-di-hydride, di-butyl-di-hydride, Triethyl aluminum, triisobutyl aluminum and di-iso-butyl aluminum hydride are preferred. Diisobutyl aluminum hydride is particularly preferred.

Examples of alumoxanes (VII) are: methylalumoxane, ethylalumoxane and isobutylalumoxane, preferably methylalumoxane and isobutylalumoxane.

So-called Lewis acids are used as component C. The organometallic halides in which the metal atom of group 3a) or - 8th -

4a) and halides of the elements of groups 3a), 4a) and 5a) of the periodic table, as shown in the "Handbook of Chemistry and Physics", 45th edition 1964-65. The following are mentioned in particular:

Methyl aluminum dibromide, methyl aluminum dichloride, ethyl aluminum dibromide,

Ethyl aluminum dichloride, butyl aluminum dibromide, butyl aluminum dichloride, dimethyl aluminum bromide, dimethyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum chloride, dibutyl aluminum bromide, dibutylaluminium chloride, methyl aluminum aluminesquidomomidium chloride, methyl

Antimony pentachloride, phosphorus trichloride, phosphorus pentachloride, tin tetrachloride.

Diethyl aluminum chloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, diethyl aluminum bromide, ethyl aluminum sesquibromide and / or ethyl aluminum dibromide are preferably used.

As component C, the reaction products of aluminum compounds as described as component B with halogens or halogen compounds, e.g. Triethyl aluminum with bromine or triethyl aluminum with butyl chloride can be used. In this case, the reaction can be carried out separately, or the amount of the alkyl aluminum compound required for the reaction is added to the amount required as component B.

Ethyl aluminum sesquichloride, butyl chloride and butyl bromide are preferred.

Component C can be omitted if component B contains a compound of formula VII or if component A is used of compound IV. - 9 -

As component D, inert, particulate solids with a specific surface area greater than 10, preferably 10 to 1000 m ² / g (BET), and a pore volume of 0.3 to 15, preferably 0.5 to 12 ml / g used.

The specific surface area (BET) is determined in the usual way according to S.

Brunauer, P.H. Emmet and Teller, J. Anorg. Chem. Soc. 60 (2), 309 (1938), the pore volume is determined by the centrifugation method according to M. McDaniel, J. Colloid Interface Sei. 78: 31 (1980).

Particularly suitable inert solids are silica gels, precipitated silicas, clays,

Aluminum silicates, talc, zeolites, carbon black, activated carbons, inorganic oxides such as silicon dioxide, aluminum oxide, magnesium oxide, titanium dioxide, silicon carbide, polyethylene, polystyrene or polypropylene, preferably silica gels, precipitated silicas, zeolites, polystyrene, polypropylene and carbon black, particularly preferably silica Precipitated silicas, polypropylene and soot. In this case, inert is understood to mean that the solids neither have a reactive surface nor contain adsorbed material which prevent the formation of an active catalyst or react with the monomers.

The inert inorganic solids mentioned, which meet the above-mentioned specification and are therefore suitable for use, are described in more detail, for example, in Ullmanns, Enzyclopadie der Technische Chemie, volume 21, page 439 ff. (Silica gel), volume 23, page 311 ff. (Tone), volume 14, p. 633 ff. (soot), volume 24, p. 575 ff. and volume 17, p. 9 ff. (zeolites).

The inorganic solids can be used individually or in a mixture with one another.

The molar ratio in which the catalyst components A to D are used can be varied within wide limits. - 10 -

The molar ratio of component A to component B is usually 1: 1 to 1: 1000, preferably 1: 3 to 1: 200, particularly preferably 1: 3 to 1: 100. The molar ratio of component A to component C is 1: 0.4 to 1:15, preferably 1: 0.5 to 1: 8.

0.1 mmol to 1 mol of component A, preferably 1 to 50 mmol of component A, are used per 100 g of component D.

It is also possible to add a further component E to the catalyst components A to D. Component E is a conjugated diene, which can be the same diene that will later be polymerized with the catalyst. Butadiene and isoprene are preferably used.

If component E is added to the catalyst, the amount of E is preferably 1-1000 mol, based on 1 mol of component A, particularly preferably 1-

100 mol, based on 1 mol of component A. Very particularly preferably 1-50 mol, based on 1 mol of component A, of E.

The preparation of the supported rare earth metal catalyst to be used is described, for example, in EP 647 657, as well as in EP 0 736 549

Carrying out the process in the gas phase using the catalysts mentioned.

The amount of the catalyst to be used is usually 0.01 to 10, in particular 0.1 to 5,% by weight, based on the monomers used.

The cheapest amount can be easily determined by means of appropriate preliminary tests.

The process according to the invention can be carried out either continuously or batchwise in the customary reactors suitable for this. - 11 -

The process according to the invention is preferably carried out in the gas phase.

As mentioned, the regulator according to the invention can be added continuously or intermittently, for example at the start of the reaction or during the reaction.

Suitable reactors are e.g. Stirred reactors, rotating reactors, stirred / rotating reactors, mixing nozzle reactors, fluidized bed or fluidized bed reactors.

The regulators according to the invention can optionally be used together with inert diluents, such as alkanes, e.g. Methane, ethane, propane, butane and / or pentane, or with nitrogen or argon. They can also be absorbed into solids in solid form and fed into the reaction space. As solids e.g. the same substances are suitable that can be used as catalyst supports. The amount of inert diluent or diluent mixture can also be easily determined by appropriate preliminary tests.

To improve the flowability, flow agents or powdering agents can be introduced into the reaction space.

The polydienes obtained by the process according to the invention have a high 1,4-cis content (approx. 60 to 99.9%) and are predominantly in free-flowing, non-bonded form. The average particle diameter of the polymers can be up to several centimeters. The average particle diameter is preferably 0.05 to 1.5 cm.

The polydienes obtained have average Mooney values (ML 1 + 4 ', 100 ° C.) of 30 to 180 ME, preferably 50 to 70 ME. - 12 -

The polymers obtained according to the invention can be stabilized, compounded and vulcanized in a known manner. They are mainly used to build car tires.

- 13 -

example 1

a) Pretreatment of the carrier:

Zeosil 1165 MP was used as the carrier. Zeosil 1165 MP is a precipitated silica from Rhone Poulenc with an average particle size of 252 μm and a BET surface area of 139 m ² / g. The pore volume is 1.97 ml / g. Before use, the Zeosil 1165 MP was dried at 900 ° C in a nitrogen countercurrent and filled with the exclusion of air and moisture.

b) Preparation of the catalyst:

A catalyst was prepared by using 120 ml of dry n-hexane in a 1 liter flask equipped with a ^ feed and a magnetic stirrer.

150 mmoles of diisobutyl aluminum hydride (DIB AH) and 5.0 mmoles of ethyl aluminum sesquichloride (EASC) were mixed. After 1.25 g of butadiene was introduced into the solution, 5.0 mmol of neodymium versatate (NDV) was added. The resulting mixture was added to a slurry of 100 g of the carrier described under a) in 200 ml of n-hexane. After 5 minutes the mixture was evaporated to dryness in vacuo. 106 g of a free flowing powder were isolated.

c) Preparation of the superplasticizer:

A solution of 25 mmol of DIB AH, dissolved in 300 ml of hexane, was added to 100 g of Vulkasil S and the mixture was evaporated to dryness in vacuo with stirring. - 14 -

d) Polymerization:

The polymerization was carried out in a rotary evaporator equipped with a magnetic stir bar, a mercury pressure relief valve and connections to a vacuum pump and to the supply with gaseous nitrogen and

Butadiene and a thermocouple reaching almost to the bottom of the 1 1 flask was carried out. The inclination of the rotary evaporator was adjusted so that the axis of rotation formed an angle of 45 ° with that of the bar magnet. The total volume of the apparatus was 2 liters. The apparatus was via an adjustable valve with one on one

Balance pressure cylinder in which the regulator / monomer mixture was located. The valve was opened when the pressure in the apparatus had dropped to 900 mbar and was closed when a pressure of 950 mbar was exceeded.

9.8 g of the catalyst and 8 g of the eluent prepared under lc) were introduced into the flask under nitrogen. The apparatus was evacuated to 1 mbar and, while stirring and rotating, filled with a gaseous mixture of 1,2- and 1,3-butadiene to a pressure of 950 mbar. This mixture was prepared by filling 1.5 g of 1,2-butadiene and 301 g of 1,3-butadiene into a 1 liter pressure cylinder. The temperature rose to 34 ° C within one minute.

The apparatus was heated with a hot air blower, the temperature of which was adjustable, so that a temperature of 60 ° C. was maintained in the bed. The reaction was terminated after 6 hours. The yield was 154.1 g. The polymer was stopped and stabilized with 1g Vulkanox BKF from Bayer AG, dissolved in 200ml acetone. The excess acetone was removed in vacuo. The Mooney viscosity was 50 ME. Content of cis-l, 4 double bonds: 96.5% - 15 -

Example 2

The polymerization was carried out in the same manner as in Example 1. 9.3 g of the catalyst described under lb) and 14.9 g of the eluent described under lc) were used. The polymerization was carried out at 60 ° C. with a mixture which had been prepared from 3 g of 1,2-butadiene and 298 g of 1,3-butadiene. The polymerization was terminated after 4 hours. The yield was 138.9 g. The polymer was stabilized with 0.6 g Vulkanox BKF. The Mooney viscosity was 19 ME.

Example 3

The polymerization was carried out in the same manner as in Example 1. 10.6 g of the catalyst described under lb) and 10.6 g of the eluent described under lc) were used. The polymerization was carried out at 90 ° C. using a mixture which had been prepared from 0.75 g of 1,2-butadiene and 299 g of 1,3-butadiene. The polymerization was stopped after 3.5 hours. The yield was 185 g. The polymer was stabilized with 0.9 g Vulkanox BKF. The Mooney viscosity was 21 ME.

Comparative example

The polymerization was carried out in the same manner as in Example 1. 9.5 g of the catalyst described under lb) and 8.7 g of the eluent described under lc) were used. The polymerization was carried out without the addition of 1,2-butadiene only with 1,3-butadiene at 60 ° C. The polymerization was terminated after 4 hours. The yield was 380 g. The polymer was stabilized with 2 g Vulkanox BKF. The Mooney viscosity was 1 1 1 ME.

Claims

- 16 patent claims

1. A process for the preparation of polydienes with regulated Mooney viscosity by means of catalysts based on rare earth compounds, characterized in that the conjugated dienes used in

The presence of 0.005 to 80% by weight of 1,2-dienes, based on the sum of conjugated dienes and 1,2-dienes used, is polymerized.

2. The method according to claim 1, characterized in that one is conjugated

Dienes 1,3-butadiene, isoprene, pentadiene and / or dimethylbutadiene are used.

3. The method according to claim 1, characterized in that one carries out the inventive method at temperatures from -20 to 250 ° C and at pressures from 1 mbar to 50 bar.

4. The method according to claim 1, characterized in that the catalysts are used in amounts of 0.01 to 10 wt .-%, based on the monomers used.

5. The method according to claim 1, characterized in that one carries out the polymerization in the gas phase.