Methanol-terminated polymers containing ether

Abstract

Polymers may be functionalzed with terminal groups, where the terminal groups have, at the chain end, an ether-containing carbinol group of the formula (I)
O-A-OH]  (I)
where A is a divalent organic moiety which can comprise not only C and H but also heteroatoms, such as O, N, S, Si.

Claims

1. Polymers comprising chain ends functionalized by terminal carbinol groups, wherein: the polymers comprise diene polymers, or diene copolymers obtained via: copolymerization of dienes with vinylaromatic monomers to form polymer chains, and functionalization of chain ends of the polymer chains with one or more cycloperoxides to terminate the chain ends of the polymer chains with terminal, ether-containing carbinol groups of the formula (I)
O-A-OH]  (I) wherein A is a divalent organic moiety comprising C and H, the average molar masses(number average)of the polymers are from 10,000 to 2,000,000 g/mol; the glass transition temperature of the polymers are from −110° C. to 20° C.; and the Mooney viscosities [ML 1+4 (100° C.)] of the polymer are from 10 to 150 Mooney units.

2. The polymers according to claim 1, wherein A further comprises heteroatoms selected from the group consisting of O, N, S, and Si.

3. The polymers according to claim 1, 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 polymers according to claim 1, wherein the cycloperoxides are compounds of the general formula (III) ##STR00003## where A is a divalent organic moiety comprising C, H, and optionally O, N, S, and/or Si.

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

6. A process for producing polymers according to claim 1, the process comprising: polymerizing diene monomers or diene monomers and vinylaromatic monomers to produce polymers having reactive polymer chain ends; and terminating the polymer chains by adding one or more cycloperoxides as functionalization agents to the polymers having reactive polymer chain ends and reacting the cycloperoxides with the reactive chain ends to produce the polymers according to claim 1.

7. The process according to claim 6, further comprising adding the functionaliation reagents after polymerization of the polymers.

8. The process according to claim 6, further comprising adding an excess of functionalization reagents.

9. The process according to claim 6, further comprising adding stoichiometric amounts or a substoichiometric amount of functionalization reagents.

10. The process according to either of claim 8 or 9, wherein the amount of functionalization reagents, based on the amount of polymer having reactive polymer chain ends, is from 0.005 to 2% by weight.

11. The process according to claim 8, further comprising adding coupling reagents prior to, along with, or after adding the one or more peroxides to the polymers having reactive polymer chain ends.

12. A process for producing vulcanizable rubber compositions containing polymers functionalized by terminal groups according to claim 1, the process comprising mixing the polymers functionalized by terminal groups according to claim 1 with a vulcanizing agent to produce a vulcanizable rubber composition containing polymers functionalized by terminal groups according to claim 1.

13. Vulcanizable rubber compositions according to claim 12, wherein the composition comprises rubbers and/or rubber auxiliaries, and the rubber auxiliaries comprise antioxidants, oils, and/or fillers.

14. Vulcanizable rubber compositions comprising polymers functionalized by terminal groups of the formula (I) according to claim 1.

15. A method for producing at least tyre treads of tyres, the method comprising producing at least the tyre treads from the vulcanizable rubber compositions according to claim 14.

16. A method for producing mouldings, the method comprising producing mouldings from the vulcanizable rubber compositions according to claim 14.

17. Tyres obtainable according to claim 15.

18. Mouldings obtainable according to claim 16, the mouldings comprising a moulding selected from the group consisting of cable sheathing, hoses, drive belts, conveyor belts, roll coverings, shoe soles, sealing rings and damping elements.

Description

EXAMPLES

Example 1a

Synthesis of Styrene-Butadiene Copolymer (Comparative Example)

(1) The following were charged to an inertized 20 L, reactor: 8.5 kg of hexane, 1125 g of 1,3-butadiene, 375 g of styrene, 28 mmol of 2,2-bis(2-tetrahydrofuryl)propane and also 10 mmol of butyllithium, and the contents were heated to 70° C. The mixture was polymerized for 1 h at 70° C. with stirring. The rubber solution was then discharged, and stabilized by adding 3 g of Irganox® 1520 (2,4-bis(octylthiomethyl)-6-methylphenol) and the solvent was removed by steam-stripping. The rubber crumb was dried in vacuo at 65° C.

(2) Vinyl content (by IR spectroscopy): 51.5% by weight; styrene content (by JR spectroscopy): 24.7% by weight; glass transition temperature (DSC): −16° C.; number-average molar mass M.sub.n (GPC, PS standard): 242 kg/mol; M.sub.w/M.sub.n: 1.30; Mooney viscosity (ML1+4 at 100° C.): 71 MU

Example 1b

Synthesis of Ether-Containing Carbinol-Terminated Styrene-Butadiene Copolymer (According to the Invention)

(3) The following were charged to an inertized 20 L reactor: 8.5 kg of hexane, 1125 g of 1,3-butadiene, 375 g of styrene, 29 mmol of 2,2-bis(2-tetrahydrofuryl)propane and also 10 mmol of butyllithium, and the contents were heated to 70° C. The mixture was polymerized for 1 h at 70° C. with stirring. Thereafter, 10 mmol (1.74 g) of 3,3,5,7,7-pentamethyl-1,2,4-trioxepane were added and the contents of the reactor were heated at 70° C. for a further 20 min. The rubber solution was then discharged and stabilized by adding 3 g of Irganox® 1520, and the solvent was removed by steam-stripping. The rubber crumb was dried in vacuo at 65° C.

(4) Vinyl content (by IR spectroscopy): 51.3% by weight; styrene content (by IR spectroscopy): 24.8% by weight; glass transition temperature (DSC): −16° C.; number-average molar mass M.sub.n (GPC, PS standard): 254 kg/mol; M.sub.w/M.sub.n: 1.20; Mooney viscosity (ML1+4 at 100° C.): 73 MU

Example 1c

Synthesis of Ether-Containing Carbinol-Terminated Styrene-Butadiene Copolymer (According to the Invention)

(5) The following were charged to an inertized 20 L reactor: 8.5 kg of hexane, 1125 g of 1,3-butadiene, 375 g of styrene, 29 mmol of 2,2-bis(2-tetrahydrofuryl)propane and also 10 mmol of butyllithium, and the contents were heated to 70° C. The mixture was polymerized for 1 h at 70° C. with stirring. Thereafter, 10 mmol (2.64 g) of 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxononane were added (in the form of 41% solution in isoparaffinic hydrocarbons) and the contents of the reactor were heated to 70° C. for a further 20 min. The rubber solution was then discharged and stabilized by adding 3 g of Irganox® 1520, and the solvent was removed by steam-stripping. The rubber crumb was dried in vacuo at 65° C.

(6) Vinyl content (by IR spectroscopy): 51.4% by weight; styrene content (by IR spectroscopy): 24.8% by weight; glass transition temperature (DSC): −15° C.; number-average molar mass M.sub.n (GPC, PS standard): 257 kg/mol; M.sub.w/M.sub.n: 1.20; Mooney viscosity (ML1+4 at 100° C.): 75 MU

Examples 2a-c

Rubber Compositions

(7) Tyre tread rubber compositions were produced which comprise the styrene-butadiene copolymer from Example 1a as comparative example (rubber composition 2a), and also the ether-containing carbinol-terminated styrene-butadiene copolymers according to the invention from Example 1b and 1c (rubber compositions 2b and 2c). Table 1 lists the constituents. The rubber compositions (without sulphur and accelerator) were produced in a 1.5 L kneader. The sulphur and accelerator constituents were then admixed on a roll at 40° C.

(8) TABLE-US-00001 TABLE 1 Constituents of tyre tread rubber compositions (data in phr: parts by weight per 100 parts by weight of rubber) Comparative Inventive Inventive example example example 2a 2b 2c Styrene-butadiene copolymer from Example 1a 70 0 0 Ether-containing carbinol-terminated styrene-butadiene copolymer 0 70 0 from Example 1b Ether-containing carbinol-terminated styrene-butadiene copolymer 0 0 70 from Example 1c High-cis-content polybutadiene (BUNA ™ CB 24 from Lanxess 30 30 30 Deutschland GmbH) Silica (Ultrasil ® 7000) 90 90 90 Carbon black (Vulcan ® J/N 375) 7 7 7 TDAE oil (Vivatec 500) 36.3 36.3 36.3 Processing aid (Aflux 37) 3 3 3 Stearic acid (Edenor C 18 98-100) 1 1 1 Antioxidant (Vulkanox ® 4020/LG from Lanxess Deutschland GmbH) 2 2 2 Antioxidant (Vulkanox ® HS/LG from Lanxess Deutschland GmbH) 2 2 2 Zinc oxide (Rotsiegel zinc white) 2 2 2 Wax (Antilux 654) 2 2 2 Silane (Si 69 ® from Evonik) 7.2 7.2 7.2 Diphenylguanidine (Vulkacit ® D/C from Lanxess Deutschland GmbH) 2.2 2.2 2.2 Sulphenamide (Vulkacit ® NZ/EGC from Lanxess Deutschland GmbH) 1.6 1.6 1.6 Sulphur (90/95 ground sulphur, Chancel) 1.6 1.6 1.6 Sulphonamide (Vulkalent ® E/C) 0.2 0.2 0.2

Examples 3a-c

Vulcanizate Properties

(9) The tyre tread rubber compositions of Examples 2a-c according to Table 1 were vulcanized at 160° C. for 20 minutes. The properties of the corresponding vulcanizates have been listed as Examples 3a-c in Table 2.

(10) TABLE-US-00002 TABLE 2 Vulcanizate properties Comparative Inventive Inventive example example example 3a 3b 3c Styrene-butadiene copolymer in vulcanizate: Styrene-butadiene copolymer from Example 1a X Ether-containing carbinol-terminated styrene-butadiene X copolymer from Example 1b Ether-containing carbinol-terminated styrene-butadiene X copolymer from Example 1c Vulcanizate properties: Rebound resilience at 23° C. [%] 28 30 30 Rebound resilience at 60° C. [%] 50.5 54 54 tan δ maximum (MTS amplitude sweep at 1 Hz, 60° C.) 0.193 0.165 0.175 tan δ at 0° C. (dynamic damping at 10 Hz) 0.291 0.342 0.346 tan δ at 60° C. (dynamic damping at 10 Hz) 0.120 0.111 0.108 Elongation at break (S2 test specimen) [%] 428 410 423 Tensile stress at break (S2 test specimen) [MPa] 18.3 18.7 18.9 Abrasion (DIN 53516) [mm.sup.3] 95 92 90

(11) Tyre applications need low rolling resistance, and this is present if the values measured in the vulcanizate are high for rebound resilience at 60° C. and low for tan δ in dynamic damping at high temperature (60° C.) and low for tan δ maximum in the amplitude sweep. As can be seen in Table 2, the vulcanizates of Examples 3b and 3c according to the invention feature high rebound resilience at 60° C., low tan δ in dynamic damping at 60° C. and low tan δ maximum in the amplitude sweep.

(12) Tyre applications also need high wet skid resistance and this is present when the vulcanizate has a high tan δ value in dynamic damping at low temperature (0° C.). As can be seen in Table 2, the vulcanizates of Examples 3b and 3c according to the invention feature a high tan δ value in dynamic damping at 0° C.

(13) Tyre applications also need high abrasion resistance. As can be seen from Table 2, the vulcanizates of Examples 3b and 3c according to the invention feature low DIN abrasion.