THIOETHER SILANES, METHOD FOR THE PRODUCTION THEREOF, AND USE THEREOF

Abstract

The invention relates to thioether silanes of the formula I

(R.sup.1).sub.x(R.sup.2).sub.3-xSi—R.sup.3—S—C(CH.sub.2R.sup.4).sub.y(R.sup.5).sub.3-y   (I),

which are prepared by reacting the silane of the formula II

(R.sup.1).sub.x(R.sup.2).sub.3-xSi—R.sup.3—SH   (II)

with an alkene of the formula III

R.sup.4—HC═C(CH.sub.2R).sub.y-1(R.sup.5).sub.3-y   (III).

The thioether silanes can be used for production of rubber mixtures.

Claims

1. A thioether silane of formula I,
(R.sup.1).sub.x(R.sup.2).sub.3-xSi—R.sup.3—S—C(CH.sub.2R.sup.4).sub.y(R.sup.5).sub.3-y   (I), wherein each R.sup.1 is independently selected from the group consisting of a C1-C10-alkoxy group, a phenoxy group, a C4-C10-cycloalkoxy group, and an alkyl polyether group, wherein the alkyl polyether group is —O—(R.sup.6—O).sub.r—R.sup.7, wherein each R.sup.6 is independently selected from the group consisting of a branched C 1-C30 hydrocarbon group, an unbranched C1-C30 hydrocarbon group, a saturated C1-C30 hydrocarbon group, an unsaturated C1-C30 hydrocarbon group, an aliphatic C1-C30 hydrocarbon group, an aromatic C1-C30 hydrocarbon group, and a mixed aliphatic/aromatic divalent Cl-C30 hydrocarbon group, wherein r is an integer from 1 to 30, wherein each R.sup.7 is independently selected from the group consisting of an unsubstituted group, a substituted group, a branched group, an unbranched group, a monovalent alkyl group, an alkenyl group, an aryl, and an aralkyl group, wherein each R.sup.2 is independently selected from the group consisting of a C6-C20-aryl group, a C1-C10-alkyl group, a C2-C20-alkenyl group, a C7-C20-aralkyl group, and a halogen, wherein R.sup.3 is selected from the group consisting of a branched C 1-C30 hydrocarbon group, an unbranched C1-C30 hydrocarbon group, a saturated C1-C30 hydrocarbon group, an unsaturated C1-C30 hydrocarbon group, an aliphatic C1-C30 hydrocarbon group, an aromatic C1-C30 hydrocarbon group, and a mixed aliphatic/aromatic divalent C1-C30 hydrocarbon group, wherein each R.sup.4 is independently selected from the group consisting of H, a branched C1-C30 hydrocarbon group, an unbranched C1-C30 hydrocarbon group, a saturated C1-C30 hydrocarbon group, an unsaturated C1-C30 hydrocarbon group, and an aliphatic C1-C30 hydrocarbon group, wherein each R.sup.5 is independently selected from the group consisting of an unsubstituted C6-C20-aryl group, an alkyl-substituted C6-C20-aryl group, and a —C≡C—R.sup.8 group, wherein each R.sup.8 is independently selected from the group consisting of H, an unsubstituted alkyl group, a substituted alkyl group, a branched alkyl group, an unbranched monovalent alkyl group, and a C6-C20-aryl group, and wherein x=1, or 3, and y=1 or 2.

2. The thioether silane of claim 1, wherein each R.sup.5 is independently selected from the group consisting of an unsubstituted C6-C20-aryl group and an alkyl-substituted C6-C20-aryl group.

3. The thioether silane of claim 2, wherein R.sup.5 is phenyl.

4. The thioether silane of claim 3, wherein y=2.

5. A process for preparing the silane of claim 1, comprising reacting a silane of formula II,
(R.sup.1).sub.x(R.sup.2).sub.3-xSi—R.sup.3—SH   (II), with an alkene of formula III,
R.sup.4—HC═C(CH.sub.2R.sup.4).sub.y-1(R.sup.5).sub.3-y   (III).

6. The process of claim 5, AlCl.sub.3 is used as catalyst in the reacting.

7. The process of claim 5, wherein R.sup.4 is H, and R.sup.5 is phenyl.

8. A rubber mixture, comprising at least one rubber and at least one thioether silane of claim 1.

9. The rubber mixture of claim 8, further comprising a mercaptosilane.

10. An item comprising the rubber mixture of claim 8, wherein the item is at least one selected from the group consisting of a pneumatic tyre, a tyre tread, a cable sheath, a hose, a drive belt, a conveyor belt, a roll covering, a tyre, a footwear sole, a gasket rings, and a damping element.

Description

EXAMPLES

[0169] Determinations of purity were made by gas chromatography or NMR.

[0170] Gas chromatography: temperature programme: 70° C.-5 min-20° C./min-260° C.-15 min; column: Agilent HP5, length: 30 m-diameter: 230 μm-film thickness: 0.25 μm; detector: TCD. NMR spectra were recorded on a 400 MHz NMR instrument from BRUKER. The spectra were each calibrated to the signal of tetramethylsilane at 0.00 ppm for 1 H, 13C and 29Si spectra. In determinations of purity, tetramethylbenzene or dimethyl sulfone was used as internal standard.

Comparative Example 1: (3-(tert-butylthio)propyl)triethoxysilane

[0171] To an initial charge of tert-butylthiol (119 g; 1.10 eq) was added dropwise sodium ethoxide (w=21%; 408 g; 1.05 eq). The mixture was stirred at 60° C. for about 1 h. Subsequently, CPTEO (289 g; 1.00 eq) was added dropwise at 60° C. Then the reaction mixture was refluxed for 5 h and then excess low boilers and solvent were removed by distillation at standard pressure. The distilled suspension was filtered and the crude product (filtrate) was distilled overhead by means of vacuum distillation (boiling point 90-95° C. and 0.6 mbar). (3-(tert-Butylthio)propyl)triethoxysilane (72% yield, purity: 99.6 a% determined by GC) was obtained as a clear colourless oil.

Comparative Example 2: triethoxy(3-((1-phenylethyl)thio)propyl)silane

[0172] Under a protective gas atmosphere, ethanol (260 g; 11.9 eq) and elemental sodium (11.5 g; 1.00 eq) were used to prepare ethanolic sodium ethoxide solution. Thereafter, 3-mercaptopropyltriethoxysilane was added dropwise. On completion of addition, stirring was continued for 30 min. The reaction solution was heated to 60° C. by means of an oil bath, and 1-bromoethylbenzene was added dropwise within 20 min. The reaction mixture was stirred at 60° C. for a further 11 h. After the reaction had ended, the suspension was filtered and freed of low boilers by distillation. Triethoxy(3-((1-phenylethyl)thio)propyl)silane (93% yield, purity: >95% (NMR)) was obtained as a clear yellow oil.

Example 1: (3-((1,1-Diphenylethyl)thio)propyl)triethoxysilane

[0173] An initial charge of 3-mercaptopropyltriethoxysilane (327 g; 1.0 eq), 1,1-diphenylethylene (247 g; 1.0 eq) and aluminium chloride (10.1 g; 2.0% by weight) at room temperature was stirred and heated to 80° C. by means of an oil bath. The mixture was stirred at this temperature for a further 33 hours and then cooled down to room temperature. Finally, the low boilers were removed by means of distillation.

[0174] (3-((1,1-Diphenylethyl)thio)propyl)triethoxysilane (yield: 63%, purity: 61.8% by weight (from combination of 13C and 29Si NMR with dimethyl sulfone as internal standard)) was obtained as a pale yellowish liquid.

[0175] Secondary components were 1,3-bis(3-((1,1-diphenylethyl)thio)propyl)-1,1,3,3-tetraethoxydisiloxane (28.2% by weight), triethoxy(3-(ethylthio)propyl)silane (4.6% by weight), 3-(triethoxysilyl)propanethiol (0.3% by weight), diphenylethylene (5.1% by weight).

Example 2: triethoxy(3-((2-phenylpropan-2-yl)thio)propyl)silane

[0176] An initial charge of 3-mercaptopropyltriethoxysilane (403 g; 1.0 eq), α-methylstyrene (200 g; 1.0 eq) and aluminium chloride (8.12 g; 2.0 mol %) at room temperature was stirred and heated to 100° C. by means of an oil bath. The mixture was stirred at this temperature for 16 hours and then left to cool down to room temperature. Then it was filtered and the low boilers were removed by means of distillation.

[0177] Triethoxy(3-((2-phenylpropan-2-yl)thio)propyl)silane (yield: 99%, purity: 80.1% by weight (from combination of 13C and 29Si NMR with dimethyl sulfone as internal standard)) was obtained as a colourless liquid.

[0178] Secondary components were 1,1,3,3-tetraethoxy-1,3-bis(3-((2-phenylpropan-2-yl)thio)propyl)disiloxane (11.6% by weight), triethoxy(3-(ethytthio)propyl)silane (5.1% by weight), 3-(triethoxysityl)propanethiot (0.9% by weight), α-methylstyrene (0.7% by weight), α-methylstyrene dimer (1.6% by weight).

Example 3: 7,7-Diethoxy-2-methyl-2-phenyl-8,11,14,17,20,23-hexaoxa-3-thia-7-silahexatriacontane

[0179] Triethoxy(3-((2-phenylpropan-2-yl)thio)propyl)silane (from Example 2, 106.2 g; 1.0 eq), 3,6,9,12,15-pentaoxaoctacosan-1-ol (125.3 g; 1.0 eq) and titanium tetrabutoxide (53 μl; 0.05% by weight/triethoxy(3-((2-phenylpropan-2-yl)thio)propyl)silane) added. The mixture was heated to 140° C., the ethanol formed was distilled off and, after 1 h, a pressure of 400-600 mbar was established. After 1 h, the pressure was reduced to 16-200 mbar and the mixture was stirred for 4 h. Subsequently, the reaction mixture was allowed to cool to room temperature and the reaction product is filtered. 7,7-Diethoxy-2-methyl-2-phenyl-8,11,14,17,20,23-hexaoxa-3-thia-7-silahexatriacontane (yield: 99%, transesterification level 33% polyether alcohol/Si) was obtained as a viscous liquid.

[0180] The determination of purity and the analysis of the esterification level were made by means of .sup.13C NMR. In the NMR, the shift of the CH.sub.2 group at 61.8 ppm (adjacent to the OH group) compared to the bound variant at 61.9-62.1 ppm is characteristic, and it is possible to make a comparison against remaining ethoxy groups on the silicon atom at 58.0-58.5 ppm.

Examples 4-6: Examination of Rubber Characteristics

[0181] The materials used are listed in Table 1. Test methods used for the mixtures and vulcanizates thereof were effected according to Table 2. The rubber mixtures were produced with a GK 1.5 E internal mixer from Harburg Freudenberger Maschinenbau GmbH.

TABLE-US-00001 TABLE 1 List of materials used in Examples 4-6 S-SBR BUNA ® VSL 4526-2, Ultrapolymers Deutschland GmbH f-S-SBR-1 SPRINTAN ™ SLR 4602- SCHKOPAU, TRINSEO ™ f-S-SBR-2 BUNA ® FX 3234A-2 HM, ARLANXEO © BR BUNA ® CB 24, Ultrapolymers Deutschland GmbH Silica ULTRASIL ® 7000 GR, Evonik Industries AG Carbon black CORAX ® N330, Gustav Grolmann GmbH & Co. KG VP Si 263 silane Evonik Resource Efficiency GmbH ZnO Zinkweiss Rotsiegel, Grillo Zinkoxid GmbH Stearic acid Edenor ST1, Caldic Deutschland GmbH Oil Vivatec 500, Hansen & Rosenthal KG Wax Protektor G 3108, Paramelt B.V. 6PPD Vulkanox ® 4020/LG, Rhein- Chemie GmbH TMQ Vulkanox ® HS/LG, Rhein- Chemie GmbH DPG Rhenogran ® DPG-80, Rhein- Chemie GmbH CBS Vulkacit ® CZ/EG-C, Rhein- Chemie GmbH Sulfur ground sulfur, Azelis S.A. TBzTD Richon TBzTD OP, Weber & Schaer GmbH & Co. KG NR SMR 10, Wurfbain Nordmann GmbH masticated at Harburg- Freudenberger Maschinenbau GmbH

TABLE-US-00002 TABLE 2 List of physical test methods used in Examples 4-6 Method Standard Rubber Process Analyzer (RPA) Strain Sweep ASTM D7605 Difference in shear modulus (G*): maximum shear modulus (MPa)—minimum shear modulus (MPa) Tensile strain on S1 test specimens at 23° C. DIN 53 504 Tensile strength (MPa) Modulus at 300% elongation (MPa) Strengthening factor: modulus at 300% elongation (MPa)/modulus at 100% elongation (MPa) Abrasion test (mm.sup.3) DIN EN ISO 4649 ASTM D5963 Dynamic/mechanical analysis at 60° C. DIN 53513 Dynamic complex modulus E* at 60° C. (MPa)

Example 4: Solution Styrene-Butadiene Rubber/Butadiene Rubber Mixture (S-SBR/BR) with Silanes from Comparative Examples 1 and 2 and Examples 1-3

[0182] The mixture formulation is listed in Table 3.

TABLE-US-00003 TABLE 3 Mixture formulation of the S-SBR/BR mixture Mixture 1 Mixture 2 Mixture 3 Mixture 4 Mixture 5 Mixture 6 phr phr phr phr phr phr Substance Comparison Comparison Inventive Inventive Inventive Inventive 1st stage S-SBR 96.3 96.3 96.3 96.3 96.3 96.3 BR 30 30 30 30 30 30 Silica 80 80 80 80 80 80 Comparative 7.12 — — — — — Example 1 Comparative — 8.29 — — — — Example 2 Example 2 — — 8.62 — — 7.76 Example 3 — — — — 8.84 — VP Si 263 — — — — — 0.58 Example 1 — — — 10.81 — — Carbon 5.0 5.0 5.0 5.0 5.0 5.0 black ZnO 2.0 2.0 2.0 2.0 2.0 2.0 Stearic acid 2.0 2.0 2.0 2.0 2.0 2.0 Oil 8.75 8.75 8.75 8.75 8.75 8.75 Wax 2.0 2.0 2.0 2.0 2.0 2.0 6PPD 2.0 2.0 2.0 2.0 2.0 2.0 TMQ 1.5 1.5 1.5 1.5 1.5 1.5 2nd stage 1st stage batch DPG 2.5 2.5 2.5 2.5 2.5 2.5 3rd stage 2nd stage batch CBS 1.6 1.6 1.6 1.6 1.6 1.6 Sulfur 2.0 2.0 2.0 2.0 2.0 2.0 TBzTD 0.2 0.2 0.2 0.2 0.2 0.2

[0183] The mixture production is described in Table 4.

TABLE-US-00004 TABLE 4 Mixture production of the S-SBR/BR mixture 1st stage GK 1.5 E, feed temp. 70° C., 70 rpm, filling factor 0.65 Batch temp.: 145-155° C. 0.0-0.5′ Polymers 0.5-1.0′ TMQ, 6PPD 1.0-2.0′ 1/2 silica, silane(s), ZnO, stearic acid 2.0-2.0′ Vent, purge 2.0-3.0′ a) premix carbon black and oil and add together b) 1/2 silica c) remaining constituents from the first stage 3.0-3.0′ Purge 3.0 - 5.0′ Mix at 145-155° C., optionally varying speed Eject About 45 sec, on the roll (4 mm gap), eject sheet Storage: 4-24 h/RT 2nd stage GK 1.5 E, feed temp. 80° C., 80 rpm, filling factor 0.62 Batch temp.: 145-155° C. 0.0-1.0′ 1st stage batch 1.0-3.0′ DPG, mix at 145-155° C., optionally varying speed 3.0-3.0′ Eject About 45 sec, on the roll (4 mm gap), eject sheet Storage: 4 - 24 h/RT 3rd stage GK 1.5 E, feed temp. 50° C., 55 rpm, filling factor 0.59 Batch temp.: 90-110° C. 0.0-2.0′ 2nd stage batch, accelerator, sulfur 2.0-2.0′ Eject and process on the roll for about 20 sec, with gap 3-4 mm Storage:

[0184] The results of physical tests on the rubber mixtures specified here and vulcanizates thereof are listed in Table 5. The vulcanizates were produced from the untreated mixtures from the third stage by heating at 165° C. for 14 min under 130 bar.

TABLE-US-00005 TABLE 5 Results of physical tests on the rubber mixtures and their vulcanizates Mixture 1 Mixture 2 Mixture 3 Mixture 4 Mixture 5 Mixture 6 Method Comparison Comparison Inventive Inventive Inventive Inventive Untreated mixture Δ modulus 0.26 0.28 0.23 0.20 0.16 0.16 (RPA)/MPa Vulcanizate DIN 125 103 76 80 94 77 abrasion/ mm.sup.3

[0185] As apparent from Table 5, mixtures 3-6 comprising the inventive silanes, by comparison with comparative mixtures 1 and 2, have a lower difference in modulus in the RPA strain sweep, which indicates a reduced filler network. Moreover, the vulcanizates of these mixtures show a significant reduction in abrasion in the DIN test.

Example 5: Functionalized Solution Styrene-Butadiene Rubber/Butadiene Rubber Mixture (f-S-SBR/BR) with Silanes from Comparative Examples 1 and 2 and Example 2

[0186] The mixture formulation is listed in Table 6.

TABLE-US-00006 TABLE 6 Mixture formulation of the f-S-SBR/BR mixture Mixture 7 Mixture 8 Mixture 9 Mixture 10 Mixture 11 Mixture 12 phr phr phr phr phr phr Substance Comparison Comparison Inventive Comparison Comparison Inventive 1st stage -S-SBR-1 70.0 70.0 70.0 f-S-SBR-2 96.3 96.3 96.3 BR 30 30 30 30 30 30 Silica 80 80 80 80 80 80 Comparative 7.12 — — 7.12 — — Example 1 Comparative — 8.29 — — 8.29 — Example 2 Example 2 — — 8.62 — — 8.62 Carbon black 5.0 5.0 5.0 5.0 5.0 5.0 ZnO 2.0 2.0 2.0 2.0 2.0 2.0 Stearic acid 2.0 2.0 2.0 2.0 2.0 2.0 Oil 35 35 35 8.75 8.75 8.75 Wax 2.0 2.0 2.0 2.0 2.0 2.0 PPD 2.0 2.0 2.0 2.0 2.0 2.0 TMQ 1.5 1.5 1.5 1.5 1.5 1.5 2nd stage 1st stage batch DPG 2.5 2.5 2.5 2.5 2.5 2.5 3rd stage 2nd stage batch CBS 1.6 1.6 1.6 1.6 1.6 1.6 Sulfur 2.0 2.0 2.0 2.0 2.0 2.0 TBzTD 0.2 0.2 0.2 0.2 0.2 0.2

[0187] The mixture production is described in Table 7 and Table 8.

TABLE-US-00007 TABLE 7 Mixture production of the f-S-SBR/BR mixture using f-S-SBR-1 1st stage GK 1.5 E, feed temp. 70° C., 60 rpm, filling factor 0.67 Batch temp.: 140-155° C. 0.0-0.5′ Polymers 0.5-1.0′ TMQ, 6PPD 1.0-2.0′ 1/2 silica, 1/2 oil (premixed with a little silica), silane, ZnO, stearic acid 2.0-2.0′ Vent, purge 2.0-3.0′ a) premix carbon black and 1/2 oil and add together b) 1/2 silica c) remaining constituents from the first stage 3.0-3.0′ Purge 3.0 - 5.0′ Mix at 140-155° C., optionally varying speed Eject About 45 sec, on the roll (4 mm gap), eject sheet Storage: 4-24 h/RT 2nd stage GK 1.5 E, feed temp. 70° C., 70 rpm, filling factor 0.62 Batch temp.: 140-155° C. 0.0-1.0′ 1st stage batch 1.0-3.0′ DPG, mix at 140-155° C., optionally varying speed 3.0-3.0′ Eject About 45 sec, on the roll (4 mm gap), eject sheet Storage: 4-24 h/RT 3rd stage GK 1.5 E, feed temp. 50° C., 40 rpm, filling factor 0.58 Batch temp.: 90-110° C. 0.0-2.0′ 2nd stage batch, accelerator, sulfur 2.0-2.0′ Eject and process on the roll for about 20 sec, with gap 3-4 mm Storage: 12 h/RT

TABLE-US-00008 TABLE 8 Mixture production of the f-S-SBR/BR mixture using f-S-SBR-2 1st stage GK 1.5 E, feed temp. 70° C., 60 rpm, filling factor 0.67 Batch temp.: 140-155° C. 0.0-0.5′ Polymers 0.5-1.0′ TMQ, 6PPD 1.0-2.0′ 1/2 silica, silane, ZnO, stearic acid 2.0-2.0′ Vent, purge 2.0-3.0′ a) premix carbon black and oil and add together b) 1/2 silica c) remaining constituents from the first stage 3.0-3.0′ Purge 3.0 - 5.0′ Mix at 140-155° C., optionally varying speed Eject About 45 sec, on the roll (4 mm gap), eject sheet Storage: 4-24 h/ RT 2nd stage GK 1.5 E, feed temp. 70° C., 70 rpm, filling factor 0.62 Batch temp.: 140-155° C. 0.0-1.0′ 1st stage batch 1.0-3.0′ DPG, mix at 140-155° C., optionally varying speed 3.0-3.0′ Eject About 45 sec, on the roll (4 mm gap), eject sheet Storage: 4-24 h/RT 3rd stage GK 1.5 E, feed temp. 50° C., 40 rpm, filling factor 0.58 Batch temp.: 90-110° C. 0.0-2.0′ 2nd stage batch, accelerator, sulfur 2.0-2.0′ Eject and process on the roll for about 20 sec, with gap 3-4 mm Storage: 12 h/ RT

[0188] The results of physical tests on the rubber mixtures specified here or vulcanizates thereof are listed in Table 9. The vulcanizates were produced from the untreated mixtures from the third stage by heating at 165° C. for 17 min under 130 bar.

TABLE-US-00009 TABLE 9 Results of physical tests on the vulcanizates Mixture 7 Mixture 8 Mixture 9 Mixture 10 Mixture 11 Mixture 12 Method Comparison Comparison Inventive Comparison Comparison Inventive Vulcanizate DIN 26 26 24 41 33 31 abrasion, 5N/mm.sup.3 Dynamic 6.1 6.7 7.2 6.9 7.1 8.7 stiffness at 60° C./MPa

[0189] As apparent from Table 9, the vulcanizates of mixtures 9 and 12 comprising the silane according to the invention, compared to comparative mixtures 7 and 8 or 10 and 11, show an improvement in abrasion resistance according to DIN with simultaneously higher dynamic stiffness.

Example 6: Natural Rubber Mixture (NR) Comprising Silanes from Comparative Examples 1 and 2 and Examples 1 and 2

[0190] The mixture formulation is listed in Table 10.

TABLE-US-00010 TABLE 10 Mixture formulation of the NR mixture Mixture Mixture Mixture Mixture Mixture 13 phr 14 phr 15 phr 16 phr 17 phr Compar- Compar- Inven- Inven- Inven- Substance ison ison tive tive tive 1st stage NR 100 100 100 100 100 Silica 55 55 55 55 55 Comparative 6.14 — — — — Example 1 Comparative — 7.14 — — — Example 2 Example 2 — — 7.43 — 6.69 VP Si 263 — — — — 0.50 Example 1 — — — 9.32 — ZnO 3.0 3.0 3.0 3.0 3.0 Stearic acid 3.0 3.0 3.0 3.0 3.0 Wax 1.0 1.0 1.0 1.0 1.0 PPD 1.0 1.0 1.0 1.0 1.0 TMQ 1.0 1.0 1.0 1.0 1.0 2nd stage 1st stage batch 3rd stage 2nd stage batch CBS 1.0 1.0 1.0 1.0 1.0 Sulfur 2.0 2.0 2.0 2.0 2.0 DPG 2.5 2.5 2.5 2.5 2.5

[0191] The mixture production is described in Table 11.

TABLE-US-00011 TABLE 11 Mixture production of the NR mixture 1st stage GK 1.5 E, feed temp. 70° C., 70 rpm, filling factor 0.65 Batch temp.: 140-150° C. 0.0-0.5′ Polymers 0.5 - 1.5′ 1/2 silica, silane(s), ZnO, stearic acid 1.5 -1.5′ Vent and purge 1.5 - 2.5′ 1/2 silica, remaining constituents from the firs tstage 2.5 - 2.3′ Vent and purge 2.5 - 4.0′ Mix at 140-155° C., optionally varying speed 4.0 - 4.0′ Vent 4.0 - 5.6′ Mix at 140-155° C., optionally varying speed Eject About 45 sec, on the roll (4 mm gap), eject sheet Storage: 24 h/ RT 2nd stage GK 1.5 E, feed temp. 80° C., 80 rpm, filling factor 0.62 Batch temp.: 140-150° C. 0.0-1.0′ 1st stage batch 1.0-3.0′ Mix at 140-150° C., optionally varying speed Eject About 45 sec, on the roll (4 mm gap), eject sheet Storage: 4-24 h/ RT 3rd stage GK 1.5 E, feed temp. 50° C., 55 rpm, filling factor 0.59 Batch temp.: 90-110° C. 0.0-2.0′ 2nd stage batch, accelerator, sulfur 2.0-2.0′ Eject and process on the roll for about 20 sec, with gap 3-4 mm Storage: 12 h/ RT

[0192] The results of physical tests on the rubber mixtures specified here or vulcanizates thereof are listed in Table 12. The vulcanizates were produced from the untreated mixtures by heating at 150+ C. for 17 min under 130 bar.

TABLE-US-00012 TABLE 12 Results of physical tests on the vulcanizates Mixture Mixture Mixture Mixture Mixture 13 14 15 16 17 Compar- Compar- Inven- Inven- Inven- Method ison ison tive tive tive Vulcanizate Tensile strength at 23.6 23.1 26.3 24.5 25.1 23° C./MPa M300%/MPa 6.2 7.9 9.2 8.4 9.0 M300%/M100% 3.9 4.0 4.4 4.4 4.5 DIN abrasion/ 159 152 110 136 138 mm.sup.3 Dynamic stiffness 6.7 6.8 7.4 7.0 7.2 at 60° C./MPa

[0193] It is apparent from Table 12 that the vulcanizates of mixtures 15-17 comprising the silanes according to the invention have improved tensile strength, and an improved 300% modulus and strengthening factor (M300%/M100%). Furthermore, the mixtures show advantages in abrasion resistance according to DIN with simultaneously higher dynamic stiffness.