FI63050C - VULKANISERBARA GUMMIBLANDNINGAR FOER SLITYTOR AV DAECK - Google Patents

Description

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Patent meddelat ^ ^ (51) Kv.ik.3 / iiw.ci.3 C 08 L 9/00 FINLAND — FINLAND (zi) 2720/71 * (22) Hakcmiiptivt - Anaöfcnlnpdtg 18.09.71 * ^ ^ (23) Start cloud - GHti (h «t * dt | 18.09.7 k (41) Gotten stuck - Bllvlt offanclif 12.0U.75

Patent and Registration Union · U1L., „, _ 1 (44) Nlhtivikslpumn |« kwAJulkalauii pvm. -

Patent · och registerstyreleen 'AraMun utiagd eeh utUkrtften pubiicmd 31.12.82 (32) (33) (31) Pyydetty «uolk« u * —8 # | trd prlorltut 11.10.73

Austria-Österrike (AT) A 8692/73 Proof-Styrkt (71) Degussa Aktiengesellscahaft, Weissfrauenstrasse 9 »6000 Frankfurt 1,

Federal Republic of Germany-Förbundsrepubliken Tyskland (EE) (72) Kurt Burmeister, Overath-Steinenbruck, Siegfried Wolff, Bornhem-Merten, Erhard Klötzer, Putzbrunn-Solalinden, Friedrich Thum, Rodenkirchen,

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (7! *) Oy Kolster Ab (5U) Vulcanizable rubber compounds for tire treads -Vulkaniserbara gummiblandningar för slitytor av däck

The invention relates to certain vulcanizable rubber compounds for the production of tire treads which are intended in particular for anti-slip vehicle tires on wet, snow-covered and, in particular, frozen roads.

Today, the most widely used car tires to prevent vehicles from slipping and derailing on icy or hard snow-covered roads are winter tires with carbide studs, so-called studded tires.

The use of studded tires, especially the large number of motor vehicles equipped with studded tires, entails significant disadvantages. There are severe and widespread damage to the road surface due to the formation of carriageways, which again pose new hazards, such as the known aquaplaning.

In addition, studded tires have driving defects, require longer braking distances and have unfavorable cornering stability. Nor do the speed limits of 2 63050 imposed on vehicles fitted with studded tires in order to reduce damage to road surfaces eliminate, at least not substantially. The use of studded tires during the warm seasons is not only useless, but also poses a danger to vehicles and passengers, as well as the damage to the road surface shown.

Numerous experiments have been made to increase the coefficient of friction of tire treads to improve tire traction on wet roads, ice, and compacted snow. It has been natural to try to solve this problem by mechanically acting on the ice. Thus, for example, coarse-grained additives such as small stones, cement particles, walnut shells, hard rubber, steel chips or wool, etc. have been added to the tread compound. However, these measures have little or no benefit or partially degrade the tread properties.

Attempts have also been made to improve the traction of the tread compound compositions on frozen roads, however, no decisive or desired improvements have been achieved; to date, it has not been possible to achieve or approach the grip properties of studded tires on frozen roads. Thus, it has remained an unresolved important task to come up with a slip vehicle tire in winter and in bad weather conditions, especially on ice and snow covered roads.

A tread of a vulcanized rubber compound is also known, which contains a fine, reinforcing silica pigment and a coupling agent (DE-A-2 062 883). The general formula presented therein contains a very large number of coupling agents, of which only a few silanes containing sulfur in their molecule are mentioned separately. The mercapto-propyltrimethoxysilane and triethoxysilane tested in the examples are apparently the only silanes tested in practice. The rubber compositions used to make the treads do not contain any specific alloying ingredients other than the coupling agent and the silica pigment, and no mixture ratios of the materials are mentioned. The advantageous properties of the disclosed tread compositions over those previously known in the art are due to reduced vulcanization time and improved viscosity, modulus values, permanent deformation and hysteresis or heat build up.

3 63050

Surprisingly, a tread compound for tires has now been invented and a tread made therefrom or a tire with a tread which achieves a holding capacity which currently corresponds to a studded tire with a conventional stud height of 1.2 mm and which even exceeds the studded ring in some respects.

The invention relates to a tire tread compound based on vulcanizable polybutadiene rubber, which in addition to polybutadiene rubber optionally contains a total of 0.2-8 parts by weight of other rubbers, sulfur and possible sulfur donors, 0.1-8 parts by weight of vulcanization accelerators, and at least one bis (alkoxysilyl-alkyl) oligosulphide in an amount of more than 0.1 part by weight, all parts by weight being calculated per 100 parts by weight of rubber, in addition to plasticizer oil and possibly other alloying agents commonly used in the tire industry in conventional amounts, such as carbon black, anti-aging agent , anti-fatigue, ozone protection, antioxidants, dyes, pigments, adhesion promoters, activators and waxes.

The vulcanizable tire tread compound according to the invention is characterized in that the tire tread mixture contains 50-85% by weight of the total rubber as the rubber and 50-15% by weight of the total rubber as the silane, 1-15 parts by weight of the compound as silane, who has

formula I Z-Alk-S -Alk-Z I

of

Where Z is a group

11 2. R .k R

-Si ~ —R1 -Si .—-— R2 or -Si ——— R2,

TT ^ R ^ R

1 2 wherein R is C 1-6 alkyl, C 3-8 cycloalkyl or phenyl, and R

is C 1-8 alkoxy or C 1-8 cycloalkoxy, and R 1 and R 6 may be the same or different groups, Alk is a divalent, straight or branched C 1-8 hydrocarbon group, and n is 2-6, and that the mixture contains 50-80 parts by weight of parts by weight of plasticizer oil, 80 to 130 parts by weight of silicic acid filler, and optionally 0.1 to 50 parts by weight of carbon black, the parts by weight being calculated per 100 parts by weight of rubber.

Surprisingly, despite the very high filler content, this rubber composition according to the invention has such a low viscosity that it can be well handled in the mechanical equipment currently used in tire factories. It is equally surprising that the mixture can be vulcanized despite a very high filler content and a high plasticizer oil content. that the vulcanizate has the required tear strength, tensile strength and other similar properties, even without the addition of soot, and that the behavior of treads or tires made from this new alloy is unexpectedly advantageous on wet, ice-covered or snowy slippery roads.

In particular, the addition of oligosulfide silanes of the formula I known per se contributed to the attainment of these advantageous properties.

These bis- (alkoxysilylalkyl) oligosulfides can be prepared according to BE patent publication 787,691. For example, the following silanes can be used advantageously according to the invention: bis- (3-trimethoxysilylpropyl) trisulfide, bis- (3-triethoxysilylpropyl) trisulfide, bis- (3-trimethoxysilylpropyl) tetrasulfide, bis- (3-triethoxysilylpropyl) tetrasulfide, bis- (3-diethoxymethylsilylpropyl) tetrasulfide, bis- (3-diethoxyphenylsilylpropyl) tetrasulfide, bis- (3-tricycloethoxysilylpropyl) tetrasulfide, bis- (2-triethoxysilylethyl) tetrasulfide, etc. The sulfur content of silanes can also be so that "n" in the general formula I may also mean a fraction of an integer. Preferably 2.8-4.2.

The new rubber mixture contains polybutadiene (BR) or a mixture of two polybutadienes as a polymer. In most cases, it is necessary to add other rubber grades as well. Rubber grades with the lowest possible glass transition point are particularly suitable for this purpose. These include, in particular, natural gums (NR), synthetic isoprene (IR) and trans-polypentenamer gums. Also suitable are styrene-butadiene rubbers (SBR), in particular so-called "Low-Mooney" quality copolymers, i.e. SBR types with low Mooney viscosity (see DIN 53 523, ASTM D 1646-62 or BS 1673: 3: 1951). , which are commercially available, nitrile rubbers, halobutyl rubbers such as chlorine or bromobutyl rubbers, ethylene propylene-diene terpolymers or similar synthetic rubber grades which can be advantageously crosslinked with sulfur. BR types are also particularly suitable for grades with an average molecular weight of 5 63050; those with a high concentration of cis-1,4 are preferred.

In particular, two rubber grades are used in the new rubber compounds, for example BR and SBR; or BR and NR; or BR and IR. The amounts of BR grades are 50-85% by weight of the elastomer content of the rubber compound; in each case the remaining 50-15% by weight of elastomer is covered with said other rubber grades, i.e. synthetic rubbers, with the exception of BR, or natural rubbers.

The choice of active excipients and their high concentration is particularly important. In particular, the filler is silicic acid known in the rubber processing industry as filler, in particular active or reinforcing silicic acid in highly dispersed form, which consists mainly or substantially of silica. These are, in particular, precipitated silicas of high purity and activity with BET surfaces 2 between about 50-300 m / g and average particle sizes above about 10 millimicrometers, for example between 10-50 millimicrometers. Other useful silicic acid fillers include known pyrogenically prepared silicic acids. Mixtures of silicic acid fillers can also be advantageously used.

These silicic acid fillers must be used in amounts of more than 80 parts by weight per 100 parts by weight of rubber to ensure the wet grip of the desired finished ring, despite the high polybutadiene content of the mixture. The amounts of silica fillers in the mixture are thus higher than the soot proportions commonly used in tire treads to date, as the rubber mixture could not be treated due to the increased viscosity without bis- (alkoxysilylalkyl) oligosulfide and thus the desired vulcanizate quality, tear strength, tear strength, The upper limit of the silica content can be varied according to the desired properties of the mixture and the vulcanizate and can be determined by a person skilled in the art. Suitably the amount of filler is about 80 to 130 parts by weight, preferably 90 to 120 parts by weight per 100 parts by weight of rubber.

In many cases, it has proved expedient to thoroughly mix the oligosulfide silanes with a portion of the active silicic acid in advance, for example in equal proportions (by weight) and then add this silanic acid mixture to the other rubber compound components and then mix them as a first mixing step with rubber and plasticizer.

It is particularly advantageous to add activators to the rubber composition according to the invention. These substances, known as basic activators or also as filler activators, are, for example, diphenylguanidine, hexamethylenetetramine, o-tolylguanidine, triethanolamine, cyclohexylamine, diethylene glycol and other similar known guanidines, amines or polyhydric alcohols. The amounts of these basic activators to be used must be selected according to the amounts of fillers and are about 0.2 to 8 parts by weight for every 100 parts by weight of white filler.

If desired, for example for coloring, carbon black can also be added to the rubber compound according to the invention. It can generally be added in an amount of about 0.1 to 50 parts by weight per 100 parts by weight of rubber, if even smaller amounts are desired. In this case, all types of carbon black are possible, especially those used for treads in the rubber industry. An example is HAF seines and especially ISAF seines.

The plasticizer oil used according to the invention is an important component of the new rubber compound. Its amount in the mixture should be 50 to 80 parts by weight per 100 parts by weight of rubber. Preferably, plasticizer oils are used, also known as process oils, which are of the naphthenic oil types. Particularly preferred are plasticizer oils having a pour point of 0-60 ° C, preferably -10 ° -55 ° C. Plasticizer oils with significant aromatic components can also be used. Mixtures of different plasticizer oils can also be used advantageously. Emollient oils or process oils (process oils) are regular petroleum fractions that can also be modified as needed.

Bis- (alkoxysilylalkyl) oligosulfides are generally added to the rubber mixture in an amount of 0.1 to 25 parts by weight, preferably 1.0 to 15 parts by weight per 100 parts by weight of rubber.

Adhesive additives are substances or mixtures of substances which, during vulcanization, provide a good bond between the rubber compound and the accessories used in the manufacture of tires, such as metals or textiles, for example steel wire reinforcements, textile reinforcements, glass fiber reinforcements, edge thickening wires and the like; they are added in normal amounts.

7 63050

The novel rubber compounds preferably contain sulfur for vulcanization, optionally also a sulfur donor such as the known N, N'-dithio-bis-hexahydro-2H-azepin-2-one and 2-benzthiazylyldithio-N-morpholide in a total amount of about 0 , 2-5 parts by weight per 100 parts by weight of rubber, and at least one vulcanization accelerator about 0.1 to 8 parts by weight per 100 parts by weight of rubber. Peroxides, for example dicumyl peroxide, can also be used for vulcanization for special purposes.

According to the invention, it is particularly advantageous if the sulfur-containing triazine derivatives disclosed in GB Patent 1,201,862, for example bis- (2-ethylamino-4-diethylaminotriazin-6-yl) disulfide, are added as accelerators in sulfur vulcanization, together with other known accelerators. with, for example, diphenylguanidine.

Preferably, organic acids such as stearic, benzoic or salicylic acid are also used in the mixture and, if desired, zinc oxide or lead oxide in conventional amounts. It is also advantageous to add to the mixtures according to the invention auxiliaries known per se, such as an antioxidant and an anti-fatigue agent, as well as an anti-aging agent and, if appropriate, also a protective agent in conventional amounts corresponding to ozone. The mixture may further contain other known additives used in the rubber industry, such as pigments, colorants, other known filler adhesion enhancers, waxes, activators and the like in conventional amounts.

The production of rubber compounds and the production of tires, for example by injection molding and vulcanization, take place using conventional working methods and with the aid of known equipment which is common in the rubber industry.

The rubber mixture is preferably prepared by a known "upside-down" method in a kneading device. Further processing of the mixture is conveniently carried out by spraying using conventional spraying equipment.

The compression and vulcanization can be carried out at conventional temperatures in the range of about 100 to 300 ° C, preferably 130 to 240 ° C. For this purpose, standard vulcanization equipment is used in the tire industry.

eXAMPLES

The composition (in parts by weight) of the two mixtures according to the invention is as follows: 63050 8

Relationship __1__2_

Low-Mooney-styrene-butadiene rubber 30 30

High cis-1,4 polybutadiene rubber j 70 70

Precipitated active silicic acid, surface area according to BET dimensions-2 tuna 130 m / g. Average particle size: 28 millimicrometers.

Ultrasil VN 2 DEGUSSA 95 114

Bis- (3-triethoxysilylpropyl) tetrasulfide 5 6

Zinc oxide 3 3

Stearic acid 1 1

High aromatic plasticizer oil 48 69

Anti-aging agent N-isopropyl-N'-phenyl · p-phenylenediamine 1,2 1,2

Anti-aging agent phenyl-β-naphthylamine ""

Benzothiazolyl-2-cyclohexylsulfenamide ""

Diphenylguanadine 3.15 2.8

Tetramethylthiurane monosulfide - 0.1

Sulfur 2__2 _260.75 301.5

Both blends and their vulcanizates were compared with the tread compound "A" for treads of a conventional German-made commercial tire and the next carbon black-containing blend "B" and its vulcanizate.

_Seos B

oily styrene-butadiene rubber 96.5 cis-1,4-polybutadiene 30 ISAF carbon black (Corax 6, DEGUSSA) 75

Zinc oxide 4

Stearic acid 1,2

High aromatic plasticizer oil 15

Anti-aging agent N-isopropyl-N'-phenyl-p-phenylenediamine 1.5

Anti-aging agent phenyl-β-naphthylamine "

Benzothiazolyl-2-cyclohexylsulfenamide 1,2

Sulfur 1.6 _227.5 9 63050

The following abbreviations were used in the experiments and their results:

Abbreviation Marking__Measured t ^ Mooney-Scorch time minute t ^ Mooney-Cure time "ML 4 Mooney plasticity at 100 ° C, normal rotor, test time 4 minutes 3

Density Density g / cm VZ vulcanization time minute

VT "temperature ° C

2 ZF tensile strength kp / cm M 300 tension value with 300% elongation "BD elongation at break%

Bl.D. permanent elongation after fracture% E tensile elasticity% SH Shore A hardness 2 EF tensile strength kp / cm 3 A wear mm A1 T__temperature rise (see Goodrich-Flexometer) ° C_

Koestusnormit

Physical experiments were performed at room temperature according to the following normative brochures:

Tensile strength, elongation at break and tension value with 6 mm thick tires DIN 53 504

Further tear strength "53 507

Ductility "53 512

Shore A Hardness "53 505

Density "53 550

Money Testing ”53,524

Goodrich flexometer (heat build up Δ, Τ) ASTM C 623-62

Wear _.__ DIN 53 516_

The vulcanizates were always prepared in a steam-heated bed press at the indicated vulcanization temperatures.

63050 10

Properties of vulcanized tower mixtures

Mixture__A__B__1__2_ t5 (130 ° C) 18/5 29.6 15.4 14.0 t35 22.2 33.3 20.1 17.4 ML 4 I 60 I 64 I 60 1 67_

Properties of vulcanized mixtures The vulcanization was performed at 160 ° C

Seos VZ IzF I M300 | BD bl.d.l E IsH EF A_ A 20 160 71 555 29 59 21 66 40 166 65 620 29 58 19 B 20 169 56 658 24 28 56 13 86 40 169 "690 23 27" 14

Xl 20 162 57 653 35 35 67 30 74 40 151 56 615 28 "" 27

2 20 121 42 715 50 24 "28 III

__ 40 11131 43 1.6-771 40 25 7o | 27 f_ GOODRICH-FLEXIBETER - tests

Curing temperature 160 ° C, curing time 40 minutes Impact 0.250

Specific load 11 pcs

Measurement temperature room temperature

Trial time 25 minutes

Mixture ° C Compression in percent Permanent deformation ___ static / dynamic in percent_ A 136 15.6 36.0 25.8 j B 149 16.1 36.2 27.3 j 1 79 15.4 32.0 25.9 i2 1 87 19 .4 37.5_ 34.2_

Treads were made from four alloys (1 and 2 according to the invention, A and B according to the prior art) and in turn tires were made from them. These tires were then tested in 11,63050 cars on the ice of an artificial ice rink as well as on the driveway of a road with wet rough asphalt pavement, and the results were compared with each other. The test took place in the same car. The tires all had the same profile. First, a run was performed on a track with a diameter of 20 m (track test, 4 measurement laps, run time test).

Second, in the braking test, full power braking measurements (braking deceleration by measuring the braking distance in meters) were performed from an initial speed of 30 km / h.

Third, an acceleration test was performed by driving a measurement distance of 22 m with a standing start using the highest possible acceleration (time measurement in seconds and measurement of the final speed at a distance of 25 m). The surface temperature of the artificial ice was 0-3.5 ° C. The air temperature at a height of 0.8 m above the ice surface was +2 - + 4 ° C.

Testing of tires on a wet roadway took place on a wetted asphalt tire track. With an effective diameter of 67 m, four driving tests were performed in each case. Driving time in seconds was measured using a photocell. In the braking tests, an initial speed of 50 km / h to 80 km / h was used on the wet road and full power braking measurements were then performed on the irrigated rough asphalt road. The braking distance in meters was measured and the average deceleration was determined.

The surface temperature of the track was 11-20 ° C and the air temperature 9-19 ° C.

Mean acceleration, centrifugal acceleration, or deceleration values were determined in all measurements and ^ u values (also called friction values) were calculated from them. The evaluation of the respective friction value (average) was determined for the tires made of mixture A A = 100. The following readings were obtained for the other measured friction values:

Experience Ice on a Wet Road

Mixture Tire path Braking Acceleration__Tire track Braking A 100 100 100 100 100 B 95 95 96 100 104 1 110 116 105 95 94 2 129_ 121_ 121__98_ 95 The following results can be derived from these values:

The above percentages of friction values or? U values in ice slip tests show that the tires made from the alloys 63050 12 according to the invention achieve significantly better grips on ice. A significant improvement in grip on ice could be demonstrated several times with good reproducibility.

Such good holding values on ice have not been known so far. Thus, a tread quality has been achieved which is able to replace the studded tires hitherto manufactured and used with ice in terms of advantageous behavior.

The winter tires for passenger cars used in the comparative tests have been manufactured for a few years and are commercially available. They have a very good tread quality (mixture A). This mixture A has been specially developed for tires with advantageous grip properties on ice, whereby the grip properties on ice and wet road are matched to each other. However, Mixture A is an alloy containing only carbon black as a filler, as is the tread compound B used for comparison, for which a representative alloy composition has been selected which is currently commonly used in passenger car tires. The adhesion properties of these B alloy rings on ice are slightly lower than those of the A alloy rings. Compared to mixture A, according to the invention, improvements of up to 30% and greater in adhesion properties on ice can always be achieved, which improvement can only be achieved with the mixture compositions according to the invention.

The composition of the third mixture according to the invention was as follows.

Mixture 3__Weights

Natural rubber (ML 4 n. 40) 30 Polybutadiene rubber with a cis-1,4 content of 98% 70

Precipitated active silicic acid, specific surface area measured according to BET 200 m2 / g and average particle size 28 millimicrometers (Ultrasil VN 3 DEGUSSA) 103

Quality HAF soot: improved (Corax 4 DEGUSSA) 5

Bis- (3-triethoxysilylpropyl) tetrasulfide 8

Zinc oxide 4

Stearic acid 1

Naphthenic plasticizer oil (pour point -28 ° C) 70

Anti-aging agent N-isopropyl-N'-phenyl-p-phenylenediamine 1.5 »

The anti-aging agent phenyl-γ3 -naphthylamine "continues ...

13 63050

Mixture 3 continues ...__ In parts by weight

Diphenylguanidine 3.5

Bis- (2-ethylamino-4-diethylamino-triazin-6-yl) -disulfide 2

Sulfur 2,301.5

Properties of unvulcanised mixture t5 (130 ° C) 11.4 t35 (130 ° C) 15.5 ML 4 51

Specific gravity 1.18

Properties of the vulcanized mixture

Vulcanization was performed at 150 ° C and lasted 20 minutes Tensile strength 133 Stress value at 300% elongation 62

Elongation at break 577

Permanent elongation at break 35

Torsional resilience 34

Shore A hardness 68

Further tear strength 31

Kuluma__61

Hold capacity

Measurement of the friction values (yU values) of the above mixture 3 compared to mixture 2 of the previous example.

Experience Ice on a Wet Road

Relationship__Tyreline__Brake__Brake_ 3 100 100 100 3 98_94_ 99_

The composition of the fourth mixture according to the invention was as follows

Mixture 4__Weighs

Natural rubber (ML 4 approx. 40 30 Polybutadiene rubber with a cis-1,4 content of 98% 70 continues ...

63050 14

Mixture 4 continues .., ______ by weight

Precipitated silica, measured with a specific surface area ΒΕΤ'η of 200 m2 / g and an average particle size of 18 millimicrometers. (Ultrasil VN 3 DEGUSSA) 60

Quality ISAF carbon black: improved (Corax 7 DEGUSSA) 60

Bis- (3-triethoxysilylpropyl) tetrasulfide 2.5

Zinc oxide 4

Stearic acid 1

Naphthenic plasticizer oil (pour point -28 ° C) 72

Anti-aging agent N-isopropyl-N'-phenyl-p-phenylenediamine 1.5

Anti-aging agent phenyl / 3-naphthylamine '

Diphenylguanidine "

Bis- (2-ethylamino-4-diethylamino-triazin-6-yl) -disulfide 2

Sulfur 2,308.0

Properties of unvulcanised mixture t5 (130 ° C) 21.2 t35 (130 ° C) 26.0 ML 4 74

Specific gravity 1/17

Properties of the vulcanized mixture

Vulcanization was performed at 160 ° C and lasted 20 minutes Tensile strength 80 Stress value at 300% elongation 48

Elongation at break 450

Permanent elongation at break 32

Torsional resilience 24

Shore A hardness 65

Further tear strength 15

Wear 76

Hold capacity

Determination of friction values for tires with tread compound 4 compared to conventional tires with tread compound A and in addition tread compound B.

15 63050

Test

Mixture Tire track Braking On a wet roadway ____braking_ A 100 100 100 B 100 96 100 4_ 115_116__102_

The above figures, in particular the evaluation of the friction values, show a surprisingly clear advantage of the treads of tires or tires with treads made of the rubber compounds according to the invention.

Claims (3)

16 63050 A tire tread compound based on polybutadiene rubber, which in addition to polybutadiene rubber may contain a total of 0.2 to 8 parts by weight of other rubbers, sulfur and potential sulfur donors, 0.1 to 8 parts by weight of vulcanization accelerators, and at least one bis (alkoxysilylalkyl) oligosulfide in excess of 0.1 parts by weight, all parts by weight being calculated per 100 parts by weight of rubber, in addition to plasticizer oil and possibly other alloying compounds commonly used in the tire industry in conventional amounts, such as carbon black, anti-aging agent, anti-fatigue, ozone, antioxidants, dyes, pigments, adhesion promoters, Akti and waxes, characterized in that the tire tread compound contains 50-85% by weight of polybutadiene rubber as a rubber and one or two others rubber 50-15% by weight of the total amount of rubber, as silane 1-15 parts by weight of a compound of formula I Z-Alk-Sn-Alk-Z I wherein Z is a group wherein R 2 is -SI-R 1 -Si-R 2 or -Si-R 2 \ 2 X 2 ^ X 2 1 2 wherein R is C 1-6 alkyl, C 1-4 cycloalkyl or phenyl, and R is lh 3- δ 2 C 1-8 alkoxy or C 1-8 cycloalkoxy, and R and R may be the same or different groups, Alk is a divalent, straight or branched C 1-8 hydrocarbon group, and n is 2-6, and that the mixture contains 50-80 parts by weight of parts by weight of plasticizer oil, 80 to 130 parts by weight of silicic acid filler, and possibly 0.1 to 50 parts by weight of carbon black, all parts by weight being calculated per 100 parts by weight of rubber. Tire tread compound according to Claim 1, characterized in that the silane contained therein is in the form of a premix containing part of the silicic acid filler contained in the tire tread mixture and optionally a portion of soot, the premix preferably consisting of equal parts by weight of filler and silane. Tire tread compound according to Claim 1 or 2, characterized in that it contains a process oil with a low pour point as a plasticizer. 17 63050