Patent Description:
It is known that sulfur-containing organosilicon compounds such as <NUM>-mercaptopropyltrimethoxysilane or bis(<NUM>-[triethoxysilyl]propyl)tetrasulfane can be used as a silane adhesion promoter or reinforcing additive in rubber mixtures with oxidic fillers, including for tyre treads and other parts of automobile tyres (<CIT>, <CIT>, <CIT>, <CIT>).

<CIT> discloses rubber mixtures based on at least one elastomer with silica as a filler and a reinforcing additive which is prepared by blending or as an in situ reaction product from at least one functional polyorganosiloxane compound, and which contain a functional organosilane as a further constituent. Monomeric units used are especially <NUM>-mercaptopropyltrialkoxysilanes or bis(trialkoxysilylpropyl)tetrasulfanes, which bear <NUM> and <NUM> alkoxy substituents respectively.

In addition, <CIT> discloses oligomeric organosilane polysulfanes which are not polycondensed to give a solid, and which contain the structural units A and/or B and/or C in any linear, branched or cyclic arrangement.

<CIT>, <CIT> and <CIT> likewise disclose oligomeric organosilanes. In addition, <CIT> discloses mercapto-functional silane compositions comprising at least one mercapto-functional silane having the chemical structure [G<NUM>-/SiXαuZβvZθw)s]m[(HS)r-G<NUM>-(SiXαuZβvZθw)s]n.

<CIT> discloses oligomeric organosilanes containing at least two different structural units within a molecule, selected from the structural units A, B, C and D joined in any desired linear, branched or cyclic arrangement
<CHM>
<CHM>.

<CIT> discloses in its examples <NUM> to <NUM> oligomeric organosilanes, which comprise units derived from mercaptopropyltrimethoxysilane and from an alkyltriethoxysilane. In the process is also used a Marlosol compound. However, there is no diol such as <NUM>-MPD, which could give rise to a unit (C) as disclosed herein.

Disadvantages of the known oligomeric organosilanes are poor tear resistance and/or poor storage stability.

It is an object of the present invention to provide oligomeric organosilanes having improved tear resistance and/or improved storage stability.

The invention provides oligomeric organosilanes containing at least structural units A, B and C in any linear, branched or cyclic arrangement
<CHM>.

The molar ratio of the alkyl polyether group -O-(R<NUM>-O)m-R<NUM> to silicon may be between <NUM> and <NUM>, preferably between <NUM> and <NUM>, more preferably from <NUM> to <NUM>, most preferably from <NUM> to <NUM>.

The molar ratio of structural unit C to silicon may be between <NUM> and <NUM>, preferably between <NUM> and <NUM>. Structural unit C may also be present in R<NUM> and/or R<NUM> and may be terminated by an OH group or be cyclically attached to the oxygen atom of the Si-O group of the same structural unit. The molar ratio of structural units A and B in the oligomeric organosilanes according to the invention may be <NUM>:<NUM> to <NUM>:<NUM>, preferably <NUM>:<NUM> to <NUM>:<NUM>, more preferably <NUM>:<NUM> to <NUM>:<NUM>.

The alkyl polyether group may preferably be -O-(CH<NUM>CH<NUM>-O)m-R<NUM>, more preferably -O-(CHzCHz-O)<NUM>-R<NUM>, most preferably -O-(CH<NUM>CH<NUM>-O)<NUM>-C<NUM>H<NUM>.

In the oligomeric organosilane according to the invention, it may preferably be the case that R<NUM> = OC<NUM>H<NUM> or -O-(R<NUM>-O)m-R<NUM>, R<NUM> = (CH<NUM>)<NUM>CH<NUM>, R<NUM> = OC<NUM>H<NUM> or -O-(R<NUM>-O)m-R<NUM>, R<NUM> = H or CH<NUM>, R<NUM> = CH<NUM>CH<NUM>, R<NUM> = C<NUM>H<NUM>, n = <NUM>, m = <NUM>, p = <NUM>.

In the oligomeric organosilane according to the invention, structural unit C may more preferably be [-O-CH<NUM>-CH(CH)<NUM>-CH<NUM>-] or [-O-CHz-CHz-].

The oligomeric organosilane according to the invention may most preferably contain the structural units.

The present invention further provides a process for preparing the oligomeric organosilanes according to the invention, which is characterized in that a mercaptosilane D, an alkylsilane E, a polyol F,
<CHM>
an alkyl polyether alcohol of the formula HO-(R<NUM>-O)m-R<NUM> where R<NUM>, R<NUM>, R<NUM>, R<NUM> n, m, p have the same definition as defined above,.

The reaction can be effected within <NUM> - <NUM>, preferably within <NUM> - <NUM>.

The reaction can be effected with stirring.

The secondary components can be separated off by distillation.

The secondary components can be separated off by distillation during the reaction or thereafter.

The secondary components can preferably be separated off during the reaction.

The secondary components can be separated off by distillation at atmospheric pressure or reduced pressure. The secondary components can preferably be separated off by distillation under reduced pressure. More preferably, they can be separated off by distillation at a pressure of <NUM>-<NUM> mbar.

Components D and E may be used in a molar ratio of <NUM>:<NUM> to <NUM>:<NUM>, preferably of <NUM>:<NUM> to <NUM>:<NUM>, more preferably of <NUM>:<NUM> to <NUM>:<NUM>.

Components D and F may be used in a molar ratio of <NUM>:<NUM> to <NUM>:<NUM>. Preferably, components D and F may be used in a molar ratio of <NUM>:<NUM> to <NUM>:<NUM>. More preferably, components D and F may be used in a molar ratio of <NUM>:<NUM> to <NUM>:<NUM>. Most preferably, components D and F may be used in a molar ratio of <NUM>:<NUM> to <NUM>:<NUM>.

Component D and the alkyl polyether alcohol of the formula HO-(R<NUM>-O)m-R<NUM> may be used in a molar ratio of <NUM>:<NUM> to <NUM>:<NUM>. Preferably, component D and the polyether alcohol of the formula HO-(R<NUM>-O)m-R<NUM> may be used in a molar ratio of <NUM>:<NUM> to <NUM>:<NUM>.

The catalyst may be added in catalytic or stoichiometric amounts. In this context, all kinds of acidic, basic or nucleophilic catalysts which are known to those skilled in the art from the SOLGEL chemistry of alkoxysilanes (see, for example,<NPL>) are also suitable for the oligomerization in the context of the invention. It is unimportant here whether the catalysts are in the same phase as the reaction solution (homogeneous catalysis) or are in the form of solids (heterogeneous catalysis) and are removed after the reaction has ended.

Preferably, the homogeneous catalysis can be conducted with a transition metal complex, for example tetrabutyl orthotitanate, or a transition metal salt. Basic catalysis can be effected, for example, with an organic base such as triethylamine, tetramethylpiperidine, tributylamine or pyridine, or with an inorganic base such as NaOH, KOH, Ca(OH)<NUM>, Na<NUM>CO<NUM>, K<NUM>CO<NUM>, CaCOs, CaO, NaHCOs, KHCOs or alkoxides such as NaOCH<NUM> or NaOC<NUM>H<NUM>. Acidic catalysis can be effected with dilute aqueous mineral acids, such as H<NUM>SO<NUM> or HCl, or solutions of Lewis acid in water. Preferably, the catalyst used may be a transition metal complex, KOH, NaOH, ammonium fluoride, H<NUM>SO<NUM> or HCl.

More preferably, the catalyst used may be a transition metal complex.

Most preferably, the catalyst used may be tetrabutyl orthotitanate.

The process according to the invention can be performed in solvent-free form or in the presence of a solvent, preferably in solvent-free form.

Solvents may be an inert organic solvent or mixture thereof, for example an aromatic solvent such as chlorobenzene, a halogenated hydrocarbon, for example chloroform, methylene chloride, an ether, for example diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran or diethyl ether, acetonitrile, a carboxylic ester, for example ethyl acetate, methyl acetate, isopropyl acetate, or an alcohol, for example methanol, ethanol, n-propanol, i-propanol, n-butanol, sec-butanol or tert-butanol.

The mercaptosilane of the formula D may, for example, be.

The alkylsilane of the formula E may, for example, be.

The polyol of the formula F may, for example, be.

The alkyl polyether alcohol may, for example, be
C<NUM>H<NUM>-(OCH<NUM>CH<NUM>)<NUM>-OH.

The catalyst can remain in the product after the reaction, be deactivated, preferably by neutralization, or be removed, preferably by filtration. More preferably, the catalyst may not be deactivated after the reaction and remain in the product.

The invention further provides for the use of the oligomeric organosilanes according to the invention in rubber mixtures.

The invention further provides rubber mixtures comprising the oligomeric organosilanes according to the invention.

The rubber mixtures according to the invention can be used for production of shaped bodies, especially pneumatic tyres or tyre treads.

The rubber mixtures according to the invention may comprise rubber, filler, preferably precipitated silica, optionally further rubber auxiliaries, and at least one oligomeric organosilane according to the invention.

The use of the oligomeric organosilanes according to the invention in rubber blending processes distinctly reduces the unpleasant release of alcohol because of the precondensation that has already taken place. Compared to the usual mode of operation, for example by simple use of bis(<NUM>-[triethoxysilyl]propyl)tetrasulfane (TESPT) as adhesion promoter, evolution of alcohol is reduced during the blending operation.

Rubber used may be natural rubber and/or synthetic rubbers. Preferred synthetic rubbers are described, for example, in W. Hofmann, H. Gupta, "Handbuch der Kautschuktechnologie".

and mixtures of these rubbers. The rubbers mentioned may additionally be silicon- or tin-coupled. In a preferred embodiment, the rubbers may be sulfur-vulcanizable. For the production of car tyre treads, it is possible in particular to use anionically polymerized S-SBR rubbers (solution SBR) with a glass transition temperature above -<NUM>, and also mixtures of these with diene rubbers. It is possible with particular preference to use S-SBR rubbers having a butadiene content with a vinyl fraction of more than <NUM>% by weight. It is possible with very particular preference to use S-SBR rubbers having a butadiene content with a vinyl fraction of more than <NUM>% by weight.

It is preferably possible to use mixtures of the abovementioned rubbers which have an S-SBR content of more than <NUM>% by weight, preferably more than <NUM>% by weight.

The rubber may be a functionalized rubber, where the functional groups may be amine and/or amide and/or urethane and/or urea and/or aminosiloxane and/or siloxane and/or silyl and/or alkylsilyl, for example N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane or methyltriphenoxysilane, and/or halogenated silyl and/or silane sulfide and/or thiol and/or hydroxyl and/or ethoxy and/or epoxy and/or carboxyl and/or tin, for example tin tetrachloride or dibutyldichlorotin, and/or silanol and/or hexachlorodisiloxane and/or thiocarboxy and/or nitrile and/or nitroxide and/or amido and/or imino and/or urethane and/or urea and/or dimethylimidazolidinone and/or <NUM>-methyl-<NUM>-thiazoline and/or <NUM>-benzothiazoleacetonitrile and/or <NUM>-thiophenecarbonitrile and/or <NUM>-(N-methyl-N-<NUM>-trimethoxysilylpropyl)thiazoline and/or carbodiimide and/or N-substituted aminoaldehyde and/or N-substituted aminoketone and/or N-substituted aminothioaldehyde and/or N-substituted aminothioketone and/or benzophenone and/or thiobenzophenone with amino group and/or isocyanate and/or isothiocyanate and/or hydrazine and/or sulfonyl and/or sulfinyl and/or oxazoline and/or ester groups.

The rubber mixture according to the invention may contain at least one filler.

Fillers usable for the rubber mixtures according to the invention include the following fillers:.

It is possible with preference to use amorphous silicas prepared by precipitation from solutions of silicates, with BET surface areas of <NUM> to <NUM><NUM>/g, more preferably <NUM><NUM>/g to <NUM><NUM>/g, in amounts of <NUM> to <NUM> parts by weight, based in each case on <NUM> parts of rubber.

With very particular preference, it is possible to use precipitated silicas as filler.

The fillers mentioned may be used alone or in a mixture.

The rubber mixtures according to the invention may contain <NUM> to <NUM> parts by weight of filler and <NUM> to <NUM> parts by weight, preferably <NUM> to <NUM> parts by weight, more preferably <NUM> to <NUM> parts by weight, of the oligomeric organosilanes according to the invention, wherein the parts by weight are based on <NUM> parts by weight of rubber.

The oligomeric organosilanes according to the invention may be used as adhesion promoter between inorganic materials, for example glass beads, glass flakes, glass surfaces, glass fibres, or oxidic fillers, preferably silicas such as precipitated silicas and fumed silicas,
and organic polymers, for example thermosets, thermoplastics or elastomers, or as crosslinking agents and surface modifiers for oxidic surfaces.

The oligomeric organosilanes according to the invention may be used as coupling reagents in filled rubber mixtures, examples being tyre treads, industrial rubber articles or footwear soles.

The rubber mixtures according to the invention may comprise further rubber auxiliaries, such as reaction accelerators, ageing stabilizers, heat stabilizers, light stabilizers, antiozonants, processing aids, plasticizers, resins, tackifiers, blowing agents, dyes, pigments, waxes, extenders, organic acids, retarders, metal oxides, and activators such as diphenylguanidine, triethanolamine, polyethylene glycol, alkoxy-terminated polyethylene glycol alkyl-O-(CH<NUM>-CH<NUM>-O)yl-H with yl = <NUM>-<NUM>, preferably yl = <NUM>-<NUM>, more preferably yl = <NUM>-<NUM>, most preferably yl = <NUM>-<NUM>, or hexanetriol, that are familiar to the rubber industry.

The rubber auxiliaries may be used in familiar amounts determined by factors including the end use. Customary amounts may, for example, be amounts of <NUM>% to <NUM>% by weight based on rubber. Crosslinkers used may be peroxides, sulfur or sulfur donor substances. The rubber mixtures according to the invention may further comprise vulcanization accelerators. Examples of suitable vulcanization accelerators may be mercaptobenzothiazoles, sulfenamides, thiurams, dithiocarbamates, thioureas and thiocarbonates. The vulcanization accelerators and sulfur may be used in amounts of <NUM>% to <NUM>% by weight, preferably <NUM>% to <NUM>% by weight, based on <NUM> parts by weight of rubber.

The rubber mixtures according to the invention can be vulcanized at temperatures of <NUM> to <NUM>, preferably <NUM> to <NUM>, optionally at a pressure of <NUM> to <NUM> bar. The blending of the rubbers with the filler, any rubber auxiliaries and the oligomeric organosilanes according to the invention can be conducted in known mixing units, such as rollers, internal mixers and mixing extruders.

The rubber mixtures according to the invention can be used for production of moulded articles, for example for the production of tyres, especially pneumatic tyres or tyre treads, cable sheaths, hoses, drive belts, conveyor belts, roller coverings, footwear soles, sealing rings and damping elements.

The oligomeric organosilanes according to the invention and the fillers are preferably added at mass temperatures of <NUM> to <NUM>, but can also be added at a later stage at lower temperatures (<NUM> to <NUM>), for example together with further rubber auxiliaries.

The oligomeric organosilanes can be added to the blending operation either in pure form or else applied to an inert organic or inorganic carrier. Preferred carrier materials are silicas, natural or synthetic silicate, aluminium oxide or carbon blacks.

The oligomeric organosilanes according to the invention are obtainable by the process according to the invention.

The oligomeric organosilanes according to the invention have improved storage stability and/or, in rubber mixtures, the advantage of improved tear resistance.

The volatile components are determined by gas chromatography by the internal standard method. For this purpose, calibration of the individual components is conducted with an internal standard such as n-nonane, n-decade or n-dodecane in an appropriate solvent. The gas chromatograph used is an HP <NUM> or HP7820 with a TCD detector. The separating column used is an HP5 column having the following properties: length: <NUM>; internal diameter: <NUM> with a film thickness of <NUM>. Alternatively, an HP1 column having the following properties is used: length: <NUM>; internal diameter: <NUM> with a film thickness of <NUM>. The temperature is <NUM>, the detector temperature <NUM>. The temperature program of the column oven is: <NUM> - <NUM> - <NUM>/min - <NUM> - <NUM>. The carrier gas used is helium with a flow rate of ~ <NUM>/min and a split ratio of <NUM>:<NUM> to <NUM>:<NUM>. The amount of sample injected is <NUM>.

This method is employed analogously for the determination of other alcohols, for example methanol.

Calculation of the content of the sample: <MAT>.

The determination of the ethanol after hydrolysis can be effected by the hydrolysis of the silane by means of sulfuric acid (<NUM> w%). Subsequently, water and sodium hydroxide (<NUM> w%) are added. The resultant mixture is subjected to steam distillation with a suitable apparatus. The distillate is collected in a corresponding standard flask, <NUM>-butanol is added as internal standard, and the mixture is made up to the mark with distilled water.

The gas chromatograph used is a capillary gas chromatograph with FID and evaluation software, for example HP7820 with OpenLab. The separating column has the following properties: length: <NUM>; internal diameter: <NUM>; film thickness <NUM>; stationary phase: Stabiwax (#<NUM>-<NUM>). The injector temperature is <NUM>, the detector temperature <NUM>. The column oven: <NUM> - <NUM> - <NUM>/min - <NUM> - <NUM>. The carrier gas used is helium with a flow rate of ~ <NUM>/min and a split ratio of ~ <NUM>:<NUM>. The combustion gas used is a hydrogen/synthetic air mixture. The amount of sample injected is <NUM>.

This method is analogously applicable to the determination of other hydrolysable alkoxy groups, for example methoxy groups.

In addition, the trialkoxysilane content, and also M, D and T structures, can be determined using <NUM>Si NMR spectrometry, which is likewise well known to the person skilled in the art. The solvent used is deuterated chloroform with tetramethylsilane as internal standard.

<NUM>Si NMR (<NUM>): <NUM>-<NUM> ppm (trialkoxysilane); <NUM>-<NUM> ppm (M structures); <NUM>-<NUM> ppm (D structures); <NUM>-<NUM> ppm (T structures).

The molar proportion of silicon-containing groups (structural units A, B) and of structural unit C, and of the attached alkyl polyether group (R<NUM>, R<NUM> = -O-(R<NUM>-O)m-R<NUM>), can be determined by using <NUM> C NMR spectroscopy, which is likewise well known to the person skilled in the art. The solvent used is deuterated chloroform with tetramethylsilane as internal standard and chromium acetylacetonate. Structural unit C may also be present in R' and/or R<NUM> and may be terminated by an OH group or be cyclically attached to the oxygen atom of the Si-O group of the same structural unit.

The oligomeric silanes were characterized by spectroscopic determination of the following ratios via integration of the corresponding <NUM> C NMR signals:.

Octyltriethoxysilane (OCTEO) and VP Si <NUM>® (MPTES, <NUM>-mercaptopropyltriethoxysilane) are silanes from Evonik Operations GmbH.

Marlosol is a polyether alcohol of the formula HO-(R<NUM>-O)m-R<NUM> with R<NUM> = CH<NUM>CH<NUM>, R<NUM> = C<NUM>H<NUM> and m = <NUM> from Sasol.

Comparative Example <NUM>, corresponding to Example <NUM> from <CIT> (MPTES:OCTEO:<NUM>-MPD = <NUM>:<NUM>:<NUM>).

An initial charge of <NUM>-mercaptopropyltriethoxysilane (MPTES) (<NUM> eq; <NUM> mol; <NUM>) together with octyltriethoxysilane (OCTEO) (<NUM> eq; <NUM> mol; <NUM>) in a round-bottom flask is mixed. Concentrated sulfuric acid (<NUM> eq; <NUM> mmol; <NUM>) is added to the mixture. Subsequently, a vacuum of <NUM> mbar is applied and the mixture is heated to <NUM>. As soon as <NUM> has been attained, <NUM>-methylpropane-<NUM>,<NUM>-diol (<NUM>-MPD) (<NUM> eq; <NUM> mol; <NUM>) is metered in within <NUM>. The ethanol formed is removed by distillation. On completion of metered addition, the mixture is stirred for a further <NUM>. As soon as the product has cooled down to room temperature, sodium ethoxide (w = <NUM>%; <NUM> eq; <NUM> mmol; <NUM>) is added to neutralize the sulfuric acid.

<NUM>C NMR (<NUM>): δ (ppm) <NUM> (m, Si-(CH<NUM>)<NUM>-SH), <NUM> (m, Si-(CH<NUM>)<NUM>-CH<NUM>), <NUM> - <NUM> (m, -(O-CH<NUM>)<NUM>CH(CH<NUM>)), <NUM>-<NUM> (m, -O-CH<NUM>-CH(CH<NUM>)-CH<NUM>-OH).

An initial charge of <NUM>-mercaptopropyltriethoxysilane (<NUM> eq; <NUM> mol; <NUM>) together with octyltriethoxysilane (<NUM> eq; <NUM> mol; <NUM>) is heated to <NUM>. A mixture of H<NUM>O (<NUM> eq; <NUM> mol; <NUM>) and concentrated hydrochloric acid (w = <NUM>%; <NUM> eq; <NUM> mmol; <NUM>) in ethanol (<NUM> eq; <NUM> mol; <NUM>) is slowly added dropwise, and the reaction mixture is stirred for a further <NUM>. The solvent and the alcohol of hydrolysis are removed under reduced pressure. To the oligomer thus obtained are added Marlosol (<NUM> eq; <NUM> mol; <NUM>) and tetra-n-butyl titanate (<NUM> eq; <NUM> mmol; <NUM>). The mixture is heated to <NUM> and the temperature is maintained for <NUM>. The ethanol formed is removed by distillation under reduced pressure.

<NUM>C NMR (<NUM>): δ (ppm) = <NUM> (m, Si-(CH<NUM>)<NUM>-SH), <NUM> (m, Si-(CH<NUM>)<NUM>-CH<NUM>), <NUM> (HO-(CH<NUM>-CH<NUM>-O)<NUM>-C<NUM>H<NUM>), <NUM> (Si-O-(CH<NUM>-CH<NUM>-O)<NUM>-C<NUM>H<NUM>).

An initial charge of <NUM>-mercaptopropyltriethoxysilane (<NUM> eq; <NUM> mol; <NUM>), octyltriethoxysilane (<NUM> eq; <NUM> mol; <NUM>) and Marlosol (<NUM> eq; <NUM> mol; <NUM>) together with tetra-n-butyl titanate (<NUM> eq; <NUM> mmol; <NUM>) is heated to <NUM>. The ethanol formed is removed by distillation. As soon as the mixture has reached <NUM>, a vacuum of <NUM> mbar is applied, which is maintained for <NUM> minutes. Next, the pressure is reduced to <NUM> mbar for <NUM> minutes. The reaction mixture is cooled down to room temperature and <NUM>-methylpropane-<NUM>,<NUM>-diol (<NUM> eq; <NUM> mol; <NUM>) and tetra-n-butyl titanate (<NUM> eq; <NUM> mmol; <NUM>) are added, and the mixture is heated again to <NUM>. The ethanol formed is removed by distillation. As soon as the mixture has reached <NUM>, a vacuum of <NUM> mbar is applied, which is maintained for <NUM> minutes, then the pressure is reduced to <NUM> mbar within <NUM> minutes. The vacuum of <NUM> mbar is maintained for <NUM> and the mixture is cooled back down to room temperature.

<NUM>C NMR (<NUM>): δ (ppm) = <NUM> (m, Si-(CH<NUM>)<NUM>-SH), <NUM> (m, Si-(CH<NUM>)<NUM>-CH<NUM>), <NUM> (HO-(CH2-CH2-O)<NUM>-C13H27), <NUM> (Si-O-(CH2-CH2-O)<NUM>-C13H27), <NUM>-<NUM> (m, -(O-CH<NUM>)<NUM>CH(CH<NUM>)), <NUM>-<NUM> (m, -O-CH<NUM>-CH(CH<NUM>)-CH<NUM>-OH).

An initial charge of <NUM>-mercaptopropyltriethoxysilane (<NUM> eq; <NUM> mol; <NUM>), octyltriethoxysilane (<NUM> eq; <NUM> mol; <NUM>), <NUM>-methylpropane-<NUM>,<NUM>-diol (<NUM> eq; <NUM> mol; <NUM>), Marlosol (<NUM> eq; <NUM> mol; <NUM>) and tetra-n-butyl titanate (<NUM> eq; <NUM> mmol; <NUM>) is heated to <NUM>. The temperature is maintained for <NUM>. The ethanol formed is removed by distillation under reduced pressure (<NUM>-<NUM> mbar), then the product obtained is cooled down to room temperature.

The formulation used for the rubber mixtures is specified in Table <NUM> below. In this table, the unit phr means parts by weight based on <NUM> parts of the crude rubber employed. The oligomeric silanes, based on the reference silane according to Comparative Example <NUM>, were used in an equimolar amount based on the mercapto group, since the mercapto group is the only function that binds to the rubber.

The molar mass of the oligomeric silanes based on the mercapto group can be calculated from the integration of the <NUM>C and <NUM>Si NMR signals according to the following formula: <MAT>.

χ13C (x) = molar proportion of component x based on the total amount of silanes from integration of the <NUM>C NMR signals = Int(x) / (lnt((-(CH<NUM>)n-SH) + Int(R<NUM>))
χ29Si (x)= molar proportion from <NUM>Si NMR based on the total amount of silanes (trialkoxysilanes, M, D and T structures) from integration of the <NUM>Si NMR signals = Int(x) / (Int (trialkoxysilanes) + Int (M structures) + Int (D structures) + Int (T structures)).

The polymer Buna® VSL <NUM>-<NUM> is a solution-polymerized SBR copolymer from ARLANXEO Deutschland GmbH, having a styrene content of <NUM>% by weight and a vinyl fraction of <NUM>% by weight. The copolymer contains <NUM>% TDAE oil and has a Mooney viscosity (ML <NUM>+<NUM>/<NUM>) of <NUM>.

The polymer Buna® CB <NUM> is a cis-<NUM>,<NUM>-polybutadiene (neodymium type) from ARLANXEO Deutschland GmbH, having a cis-<NUM>,<NUM> content of at least <NUM>% and a Mooney viscosity of <NUM>. ULTRASIL® <NUM> GR is a readily dispersible silica from Evonik Industries AG and has a CTAB surface area of <NUM><NUM>/g.

N330 is carbon black from Orion Engineered Carbons GmbH, TDAE oil used is Vivatec <NUM> from Hansen & Rosenthal GmbH & Co. KG, Vulkanox® <NUM> is 6PPD from LANXESS Distribution GmbH, Vulkanox® HS/LG is TMQ from Lanxess and Protektor™ G3108 is an antiozonant wax from Paramelt B. , Weißsiegel Spezial zinc oxide is ZnO from Grillo Zinkoxid GmbH, Palmera B1804 is palmitic/stearic acid from Caldic Deutschland GmbH & Co. Vulkacit® CZ is CBS from LANXESS Distribution GmbH. Uhoo TBzTD (tetrabenzylthiuram disulfide) is a product from Hebi Uhoo Rubber Chemicals Co. , ground sulfur from Avokal GmbH.

The rubber mixture is produced in three stages in an internal mixer according to Table <NUM>.

The general method of producing rubber mixtures and vulcanizates thereof is described in <NPL>.

Rubber testing is effected in accordance with the test method specified in Table <NUM>. Table <NUM>:.

Vulcanization is effected at a temperature of <NUM> for a period of <NUM> minutes. Table <NUM> reports the rubber data for the vulcanizates.

Claim 1:
Oligomeric organosilanes containing at least structural units A, B and C in any linear, branched or cyclic arrangement
<CHM>
where n = <NUM>-<NUM>, preferably <NUM>-<NUM>, more preferably <NUM>,
R<NUM> and R<NUM> are the same or different and are independently -OH, (C1-C4)alkoxy, preferably ethoxy, OSiR<NUM>R<NUM><NUM>, OSi((CH<NUM>)nSH)R<NUM><NUM>,
wherein structural unit C is attached via the oxygen atom to the silicon atom of structural unit A or B to form an O-Si-O bond, and is terminated by an -OH group or
is attached cyclically to the oxygen of the Si-O group of the same structural unit, and an alkyl polyether group -O-(R<NUM>-O)m-R<NUM> where R<NUM> is the same or different and is a branched or unbranched, saturated or unsaturated, aliphatic divalent C1-C30 hydrocarbon group, preferably CH<NUM>CH<NUM>, m has an average value of <NUM> to <NUM>, preferably <NUM>, and R<NUM> is an unsubstituted or substituted, branched or unbranched C1-C30-alkyl, preferably C13H17, C2-C30-alkenyl, a C6-C14-aryl group, or a C7-C40-aralkyl group,
R<NUM> is a branched or unbranched, saturated or unsaturated, aliphatic monovalent C1-C30, preferably C1-C8, more preferably C8, hydrocarbon group,
R<NUM> is identical or different branched or unbranched, saturated or unsaturated C1-C10-alkyl, C1-C10-alkyl-OH, C1-C10-alkyl-NH<NUM> or H,
and p = <NUM>-<NUM>,
characterized in that the molar ratio of the alkyl polyether group -O-(R<NUM>-O)m-R<NUM> to silicon is greater than <NUM>.