Carbinol-terminated polymers containing amine

Abstract

The present invention relates to diene polymers, wherein the diene polymers have, at the start of the polymer chains, tertiary amino groups of the formula (I) or (II) ##STR00001##
where R.sup.1, R.sup.2 are the same or different and are each alkyl, cycloalkyl, aryl, alkaryl and aralkyl radicals which may contain heteroatoms such as O, N, S and/or Si, Z is a divalent organic radical which, as well as C and H, may contain heteroatoms such as O, N, S and/or Si,
and, at the end of the polymer chains, silane-containing carbinol groups of the formula (III) ##STR00002##
or metal salts thereof or semimetal salts thereof, where R.sup.3, R.sup.4, R.sup.5, R.sup.6 are the same or different and are each an H or alkyl, cycloalkyl, aryl, alkaryl and aralkyl radicals which may contain heteroatoms such as O, N, S and/or Si, A is a divalent organic radical which, as well as C and H, may contain heteroatoms such as O, N, S and/or Si.

Claims

1. Diene polymers comprising: at the start of the polymer chains, tertiary amino groups of the formula (I) or (II) ##STR00009## where R.sup.1, R.sup.2 are the same or different and are each alkyl, cycloalkyl, aryl, alkaryl and aralkyl radicals which may contain heteroatoms, and Z is a divalent organic radical which, as well as C and H, may contain heteroatoms, and at the end of the polymer chains, silane-containing carbinol groups of the formula (III) ##STR00010## or metal salts thereof or semimetal salts thereof, where R.sup.3, R.sup.4, R.sup.5, R.sup.6 are the same or different and are each an H or alkyl, cycloalkyl, aryl, alkaryl and aralkyl radicals which may contain heteroatoms, and A is a divalent organic radical which, as well as C and H, may contain heteroatoms.

2. The diene polymers according to claim 1, wherein the silane-containing carbinol groups of the formula (III) are in the form of metal salts of the formula (IV) ##STR00011## where R.sup.3, R.sup.4, R.sup.5, R.sup.6 are the same or different and are each an H or alkyl, cycloalkyl, aryl, alkaryl and aralkyl radicals which may contain heteroatoms, A is a divalent organic radical which, as well as C and H, may contain heteroatoms, n is an integer from 1 to 4, and M is a metal or semimetal of valency 1 to 4.

3. The diene polymers according to claim 1 or 2, wherein the diene polymer is a polybutadiene, a polyisoprene, a butadiene-isoprene copolymer, a butadiene-styrene copolymer, an isoprene-styrene copolymer, or a butadiene-isoprene-styrene terpolymer.

4. The diene polymers according to claim 1, wherein: the heteroatoms are selected from the group consisting of O, N, S, Si, and any combination thereof, and M is selected from the group consisting of Li, Na, K, Mg, Ca, Fe, Co, Ni, Al, Nd, Ti, Si, Sn, and any combination thereof.

5. The diene polymers according to claim 1, wherein: the diene polymers have mean molar masses (number-average) of 10,000 to 2,000,000 g/mol, the diene polymers have glass transition temperatures of −110° C. to +20° C., and the diene polymers have Mooney viscosities [ML 1+4 (100° C.)] of 10 to 200 Mooney units.

6. The diene polymers according to claim 1, wherein: the diene polymers have mean molar masses (number-average) of 100,000 to 1,000,000 g/mol, the diene polymers have glass transition temperatures of preferably −110° C. to 0° C., and the diene polymers have Mooney viscosities [ML 1+4 (100° C.)] of 30 to 150, Mooney units.

7. A process for preparing the diene polymers according to claim 1, the process comprising: introducing functional groups at the end of the polymer chains by reaction of the polymer chains with functionalization reagents of one or more 1-oxa-2-silacycloalkanes, and introducing the tertiary amino groups at the start of the polymer chains by reaction of the polymer chains with alkali metal amides of secondary organic amines of the general formula (V) or (VI) ##STR00012## where R.sup.1, R.sup.2 are the same or different and are each alkyl, cycloalkyl, aryl, alkaryl and aralkyl radicals which may contain heteroatoms, Z is a divalent organic radical which, as well as C and H, may contain heteroatoms, and M is Li, Na, K.

8. The process according to claim 7, wherein the 1-oxa-2-silacycloalkanes are compounds of the general formula (VII) ##STR00013## where R.sup.3, R.sup.4, R.sup.5, R.sup.6 are the same or different and are each H, alkyl, cycloalkyl, aryl, alkaryl and aralkyl radicals which may contain heteroatoms, and A is a divalent organic radical which, as well as C and H, may contain heteroatoms.

9. The process for preparing diene polymers according to claim 7, further comprising: obtaining alkali metal amides by reaction of secondary organic amines with organo-alkali metal compounds in situ or in a separate preforming step, and reacting reactive ends of the polymer chains with one or more 1-oxa-2-silacycloalkanes.

10. The process according to claim 9, wherein the alkali metal amides are used as anionic polymerization initiators.

11. The process according to claim 9, wherein the secondary organic amines are pyrrolidine or hexamethyleneimine, and the organo-alkali metal compound is butyllithium.

12. The process according to claim 9, wherein: the molar amount of secondary amines is less than or equal to the molar amount of organo-alkali metal compounds, and the amount of 1-oxa-2-silacycloalkanes is between 0.005-2% by weight, based on the amount of polymer having reactive ends of the polymer chains.

13. The process according to claim 9, wherein: the ratio of the molar amount of secondary amines to the molar amount of organo-alkali metal compounds is 0.05-2.00:0.05-2.00, and the amount of 1-oxa-2-silacycloalkanes is between 0.005-2% by weight, based on the amount of polymer having reactive ends of the polymer chains.

14. The process according to claim 7, wherein the 1-oxa-2-silacycloalkanes are added after completion of the polymerization.

15. The process according to claim 7, wherein coupling reagents are used for the reaction.

16. A method for producing vulcanizable rubber compositions, the method comprising producing the vulcanizable rubber compositions from diene polymers according to claim 1.

17. Vulcanizable rubber compositions obtained according to claim 16, wherein the vulcanizable rubber compositions additionally comprise ageing stabilizers, oils, fillers, rubbers and/or rubber auxiliaries.

18. Vulcanizable rubber compositions comprising diene polymers according to claim 1 or 2.

19. Vulcanizable rubber compositions comprising functionalized diene polymers having tertiary amino groups of the formula (I) or (II) at the start of the polymer chains and functional groups of the formula (III) at the end of the polymer chains according to claim 1.

20. Vulcanizable rubber compositions comprising functionalized diene polymers having tertiary amino groups of the formula (I) or (II) at the start of the polymer chains and functional groups of the formula (IV) at the end of the polymer chains according to claim 2.

21. Vulcanizable rubber compositions comprising functionalized diene polymers having tertiary amino groups of the formula (I) or (II) at the start of the polymer chains and functional groups of the formula (III) and (IV) at the end of the polymer chains according to claim 2.

22. A method for producing tyres, the method comprising producing at least tyre tread of the tyres from the vulcanizable rubber compositions according to claim 19.

23. Tyres obtained according to claim 22.

24. A method for producing moulded articles, the method comprising producing moulded articles from the vulcanizable rubber compositions according to claim 19.

25. Moulded articles obtainable according to claim 24, wherein the moulded articles comprise cable sheaths, hoses, drive belts, conveyor belts, roll covers, shoe soles, sealing rings and damping elements.

Description

EXAMPLES

Example 1a: Synthesis of Styrene-Butadiene Copolymer, Unfunctionalized (Comparative Example)

(1) An inertized 20 l reactor was charged with 8.5 kg of hexane, 1185 g of 1,3-butadiene, 315 g of styrene, 8 mmol of 2,2-bis(2-tetrahydrofuryl)propane and 10.3 mmol of n-butyllithium and the contents were heated to 65° C. Polymerization was effected with stirring at 65° C. for 25 min. Subsequently, 10.3 mmol of cetyl alcohol were added, the rubber solution was discharged and stabilized by addition of 3 g of Irganox® 1520 (2,4-bis(octylthiomethyl)-6-methylphenol), and the solvent was removed by stripping with steam. The rubber crumbs were dried at 65° C. under reduced pressure.

(2) Vinyl content (IR spectroscopy): 50.2% by weight; styrene content (IR spectroscopy): 20.9% by weight, glass transition temperature (DSC): −25.6° C.; number-average molecular weight M.sub.n (GPC, PS standard): 258 kg/mol; M.sub.w/M.sub.n: 1.15; Mooney viscosity (ML1+4 at 100° C.): 52 ME

Example 1b: Synthesis of Styrene-Butadiene Copolymer with Tertiary Amino Group at the Start of the Chain (Comparative Example)

(3) An inertized 20 l reactor was charged with 8.5 kg of hexane, 1185 g of 1,3-butadiene, 315 g of styrene, 11.3 mmol of 2,2-bis(2-tetrahydrofuryl)propane, 14.1 mmol of pyrrolidine and 14.1 mmol of n-butyllithium, and the contents were heated to 65° C. Polymerization was effected with stirring at 65° C. for 25 min. Subsequently, 14.1 mmol of cetyl alcohol were added, the rubber solution was discharged and stabilized by addition of 3 g of Irganox® 1520, and the solvent was removed by stripping with steam. The rubber crumbs were dried at 65° C. under reduced pressure.

(4) Vinyl content (IR spectroscopy): 50.0% by weight; styrene content (IR spectroscopy): 20.8% by weight, glass transition temperature (DSC): −25.9° C.; number-average molecular weight M.sub.n (GPC, PS standard): 210 kg/mol; M.sub.w/M.sub.n: 1.19; Mooney viscosity (ML1+4 at 100° C.): 41 ME

Example 1c: Synthesis of Styrene-Butadiene Copolymer with Functionalization at the End of the Chain by Reaction with Functionalization Reagent of the Formula (VII) (Comparative Example)

(5) An inertized 20 l reactor was charged with 8.5 kg of hexane, 1185 g of 1,3-butadiene, 315 g of styrene, 8.2 mmol of 2,2-bis(2-tetrahydrofuryl)propane and 10.55 mmol of n-butylithium, and the contents were heated to 65° C. Polymerization was effected with stirring at 65° C. for 25 min. Thereafter, 10.55 mmol (1.69 ml) of 2,2,4-trimethyl-[1,4,2]oxazasilinane were added, and the reactor contents were heated to 65° C. for a further 20 min. Subsequently, the rubber solution was discharged and stabilized by addition of 3 g of Irganox® 1520, and the solvent was removed by stripping with steam. The rubber crumbs were dried at 65° C. under reduced pressure.

(6) Vinyl content (IR spectroscopy): 50.3% by weight; styrene content (IR spectroscopy): 20.9% by weight, glass transition temperature (DSC): −25.7° C.; number-average molecular weight M.sub.n (GPC, PS standard): 216 kg/mol; M.sub.w/M.sub.n: 1.18; Mooney viscosity (ML1+4 at 100° C.): 44 ME

Example 1d: Synthesis of Styrene-Butadiene Copolymer with Tertiary Amino Group at the Start of the Chain and Functionalization at the End of the Chain by Reaction with Functionalization Reagent of the Formula (VII) (Inventive)

(7) An inertized 20 l reactor was charged with 8.5 kg of hexane, 1185 g of 1,3-butadiene, 315 g of styrene, 11.3 mmol of 2,2-bis(2-tetrahydrofuryl)propane, 14.1 mmol of pyrrolidine and 14.1 mmol of n-butyllithium, and the contents were heated to 65° C. Polymerization was effected with stirring at 65° C. for 25 min. Thereafter, 14.1 mmol (2.26 ml) of 2,2,4-trimethyl-[1,4,2]oxazasilinane were added, and the reactor contents were heated to 65° C. for a further 20 min. Subsequently, the rubber solution was discharged and stabilized by addition of 3 g of Irganox® 1520, and the solvent was removed by stripping with steam. The rubber crumbs were dried at 65° C. under reduced pressure.

(8) Vinyl content (IR spectroscopy): 49.3% by weight; styrene content (IR spectroscopy): 20.3% by weight, glass transition temperature (DSC): −26.3° C.; number-average molecular weight M.sub.n (GPC, PS standard): 170 kg/mol; M.sub.w/M.sub.n: 1.29; Mooney viscosity (ML1+4 at 100° C.): 43 ME

Examples 2a-d: Rubber Compositions

(9) Rubber compositions for tyre treads were produced using the styrene-butadiene copolymers of Examples 1a-1d.

(10) The constituents are listed in Table 1. The rubber compositions (apart from sulphur and crosslinker) were produced in a 1.5 l kneader. Sulphur and accelerator were subsequently mixed in on a roller at 40° C.

Examples 3 a-d: Vulcanizate Properties

(11) To determine the vulcanizate properties, the rubber compositions of Examples 2a-d were vulcanized at 160° C. for 20 minutes. The properties of the corresponding vulcanizates are listed in Table 2 as Examples 3a-d.

(12) Using the vulcanizates, the following properties were determined: resilience at 60° C. (to DIN 33512) abrasion (to DIN 53516) ΔG*: difference between the frequency-dependent viscoelastic moduli G* at 0.5% elongation and 15% elongation at 60° C./1 Hz (MTS amplitude sweep) tan δ maximum: maximum dynamic damping in the measurement of the frequency-dependent viscoelastic modulus at 60° C./1 Hz, where tan δ=G″/G′ (MTS amplitude sweep) tan δ at 0° C., 60° C.: from the measurement of temperature-dependent dynamic damping to DIN 53513 (10 Hz, heating rate 1K.Math.min.sup.−1), where tan δ=E″/E′ elongation at break, tensile stress at yield (to DIN 53504)

(13) Resilience at 60° C., ΔG*, tan δ maximum (MTS) and tan δ at 60° C. are indicators of the hysteresis loss as the tyre rolls (rolling resistance). The higher the resilience at 60° C. and the lower the ΔG*, tan δ maximum (MTS) and tan δ at 60° C., the lower the rolling resistance of the tyre. Tan δ at 0° C. is a measure of wet skid resistance of the tyre. The higher the tan δ at 0° C., the higher the expected wet skid resistance of the tyre.

(14) TABLE-US-00001 TABLE 1 Constituents of the rubber compositions (figures in phr: parts by weight per 100 parts by weight of rubber) Comparative Comparative Comparative Inventive Example Example Example Example 2a 2b 2c 2d styrene-butadiene copolymer according to Example 1a 70 0 0 0 styrene-butadiene copolymer according to Example 1b 0 70 0 0 styrene-butadiene copolymer according to Example 1c 0 0 70 0 styrene-butadiene copolymer, according to Example 1d 0 0 0 70 high-cis polybutadiene 30 30 30 30 (BUNA ™ CB 24 from Lanxess Deutschland GmbH) silica (Ultrasil ® 7000) 90 90 90 90 carbon black (Vulcan ® J/N 375) 7 7 7 7 TDAE oil (Vivatec 500) 36.3 36.3 36.3 36.3 processing aid 3 3 3 3 (Aflux 37 from Rheinchemie Rheinau GmbH) stearic acid (Edenor C 18 98-100) 1 1 1 1 ageing stabilizer 2 2 2 2 (Vulkanox ® 4020/LG from Lanxess Deutschland GmbH) ageing stabilizer 2 2 2 2 (Vulkanox ® HS/LG from Lanxess Deutschland GmbH) zinc oxide (Rotsiegel zinc white) 3 3 3 3 wax (Antilux 654) 2 2 2 2 silane (Si 69 ® from Evonik) 7.2 7.2 7.2 7.2 diphenylguanidine (Rhenogran DPG 80) 2.75 2.75 2.75 2.75 sulphenamide (Vulkacit ® NZ/EGC from Lanxess 1.6 1.6 1.6 1.6 sulphur (Chancel 90/95 ground sulphur) 1.6 1.6 1.6 1.6 sulphonamide (Vulkalent ® E/C) 0.2 0.2 0.2 0.2

(15) TABLE-US-00002 TABLE 2 vulcanizate properties Comparative Comparative Comparative Inventive Example Example Example Example 3a 3b 3c 3d Comparative Example 2a X Comparative Example 2b X Comparative Example 2c X Comparative Example 2d X Vulcanizate properties: Resilience at 60° C. [%] 56.2 57.2 58.7 59.2 ΔG* (G*@0.5% − G*@15%) [MPa] 1.37 1.37 1.08 0.78 tan δ maximum (MTS amplitude sweep at 1 Hz, 60° C.) 0.173 0.161 0.156 0.141 tan δ at 0° C. (dynamic damping at 10 Hz) 0.269 0.263 0.279 0.294 tan δ at 60° C. (dynamic damping at 10 Hz) 0.103 0.093 0.085 0.077 Elongation at break (S2 specimen) [%] 457 414 449 422 Tensile stress at yield (S2 specimen) [MPa] 19.4 18.6 20.8 20.4 Abrasion (DIN 53516) [mm.sup.3] 69 70 74 73

(16) Tyre applications require a low rolling resistance, which exists when a high value for resilience at 60° C. and a low tan δ value in dynamic damping at high temperature (60° C.), and a low tan δ maximum in the MTS amplitude sweep, are measured in the vulcanizate. As is clear from Table 2, the vulcanizate of Inventive Example 3d is notable for high resilience at 60° C., a low tan δ value in dynamic damping at 60° C. and a low tan δ maximum in the MTS amplitude sweep.

(17) Tyre applications additionally require a low wet skid resistance, which exists when the vulcanizate has a high tan δ value in dynamic damping at low temperature (0° C.). As is clear from Table 2, the vulcanizate of Inventive Example 3d is notable for a high tan δ value in dynamic damping at 0° C.