# Patent

## Title
Oligomeric organosilanes, the production thereof and the use thereof in rubber mixtures

## Abstract

The present invention relates to 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,




wherein at least one R, R1, R2, R3, R4 or R7 group is an alkyl polyether group —O—(R5—O)m—R6,

to the preparation thereof and to the use thereof in rubber mixtures.

## Background
This application is a National Stage of PCT/EP2015/050242, which was filed on Jan. 8, 2015. This application is based upon and claims the benefit of priority to German Application No. 10 2014 200 563.9, which was filed on Jan. 15, 2014.
The present invention relates to oligomeric organosilanes, to a process for preparation thereof and to the use thereof in rubber mixtures.
It is known that sulphur-containing organosilicon compounds such as 3-mercaptopropyltrimethoxysilane or bis(3-[triethoxysilyl]propyl)tetrasulphane 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 (DE 2 141 159 DE 2 212 239, U.S. Pat. No. 3,978,103, U.S. Pat. No. 4,048,206).
EP 0 784 072 A1 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 3-mercaptopropyltrialkoxysilanes or bis(trialkoxysilylpropyl)tetrasulphanes, each of which bear 3 and 6 alkoxy substituents respectively.
In addition, EP 0964021 discloses oligomeric organosilane polysulphanes 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




WO 2006/037380, EP 0997489 and EP 1273613 likewise disclose oligomeric organosilanes.
Disadvantages of the known oligo-/polysiloxanes are poor processibility and poor tear resistance.
It is an object of the present invention to provide oligomeric organosilanes having improved processibility and/or tear resistance.
The invention provides 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,




where Y═H, F, Cl, Br, I, SCN, SH, —Sx—(CH2)nSiRR1R2 or —N(R8)2,
R8 is the same or different and is H, (C1-C16)alkyl, preferably C4-alkyl, —(CH2)2NH2, —(CH2)2NH—(CH2)2NH2 or —(CH2)2N[(CH2)2NH2]2,
with n=1-8, preferably n=2 or 3,
G=H, F, Cl, Br, I, SCN, SH, —Sx—(CH2)nSiRR1R2 or —N(R8)2, with G different from Y,
R, R1, R2, R3, R4, R7 are each independently OH, (C1-C16)alkyl, preferably methyl or ethyl, (C2-C16)alkenyl, preferably C2-alkenyl, (C6-C14) aryl, (C1-C4)alkoxy, preferably methoxy or ethoxy, an OSiR1R2R3 group or an alkyl polyether group —O—(R5—O)m—R6, where R5 is the same or different and is a branched or unbranched, saturated or unsaturated, aliphatic divalent C1-C30 hydrocarbon group, preferably —(CH2)2—, —(CH2)3— or —(CH2C(CH3)H)—, m on average is 1 to 30, preferably 3 to 8, more preferably 5, and R6 is an unsubstituted or substituted, branched or unbranched C1-C30 alkyl group, preferably a C11-C19 alkyl group, C2-C30 alkenyl, preferably a C2 alkenyl group, a C6-C14 aryl group, or a C7-C40 aralkyl group,
x on statistical average is 1-6, preferably 2-4,
z on statistical average is 1-6, preferably 2-4,
which are characterized in that at least one R, R1, R2, R3, R4 or R7 group is an alkyl polyether group —O—(R5—O)m—R6.
The alkyl polyether group may preferably be —O—(CH2CH2—O)m—R6, more preferably —O—(CH2CH2—O)5—R6, most preferably —O—(CH2CH2—O)5—C13H27.
The relative molar mass, measured by GPC, of the inventive oligomeric organosilanes in relation to a standard consisting of a mixture of siloxanes of vinyltrimethoxysilane, may be between 400 and 100 000 g/mol, preferably between 450 and 50 000 g/mol, more preferably between 600 and 10 000 g/mol.
The oligomeric organosilane may contain the structural units A and B and C, where R7 is an alkyl polyether group —O—(R5—O)m—R6, preferably with R5═—CH2CH2—, m=5 and R6═—C13H27. It may be the case here that, in the structural unit A, n=3, Y═SH, in the structural unit B, R1=ethoxy or alkyl polyether group —O—(R5—O)m—R6, R2=ethoxy or alkyl polyether group —O—(R5—O)m—R6, n=3, z=2-4, and in the structural unit C, R=phenyl, propyl or octyl and R3=ethoxy or alkyl polyether group —O—(R5—O)m—R6. The molar ratio of the molar proportion of the structural unit A to the sum total of the molar proportions of the structural units B and C may be greater than one.
The oligomeric organosilane may contain the structural units A and B, where R7 is an alkyl polyether group —O—(R5—O)m—R6, preferably with R5═—CH2CH2—, m=5 and R6═—C13H27. It may be the case here that, in the structural unit A, n=3, Y═SH, and in the structural unit B, R1=ethoxy or alkyl polyether group —O—(R5—O)m—R6, R2=ethoxy or alkyl polyether group —O—(R5—O)m—R6, n=3, z=2-4. The molar ratio of the molar proportion of the structural unit A to the molar proportion of the structural unit B may be greater than one.
The oligomeric organosilane may contain the structural units A and C, where R7 is an alkyl polyether group —O—(R5—O)m—R6, preferably with R5═—CH2CH2—, m=5 and R6═—C13H27. It may be the case here that, in the structural unit A, n=3, Y═SH, and in the structural unit C, R=phenyl, propyl or octyl and R3=ethoxy or alkyl polyether group —O—(R5—O)m—R6. The molar ratio of the molar proportion of the structural unit A to the molar proportion of the structural unit C may be greater than one.
The oligomeric organosilane may contain the structural units A and C and D, where R7 is an alkyl polyether group —O—(R5—O)m—R6, preferably with R5═—CH2CH2—, m=5 and R6═—C13H27. It may be the case here that, in the structural unit A, n=3, Y═SH, in the structural unit C, R=phenyl, propyl or octyl and R3=ethoxy or alkyl polyether group —O—(R5—O)m—R6, and in the structural unit D, G=Cl or NH2, n=3, R4=ethoxy or alkyl polyether group —O—(R5—O)m—R6. The molar ratio of the molar proportion of the structural unit A to the sum total of the molar proportions of the structural units C and D may be greater than one.
The oligomeric organosilane may contain the structural units A and D, where R7 is an alkyl polyether group —O—(R5—O)m—R6, preferably with R5═—CH7CH2—, m=5 and R6═—C13H27. It may be the case here that, in the structural unit A, n=3, Y═SH, and in the structural unit D, G=Cl or NH2, n=3, R4=ethoxy or alkyl polyether group —O—(R5—O)m—R6. The molar ratio of the molar proportion of the structural unit A to the molar proportion of the structural unit D may be greater than one.
These inventive oligomeric organosilanes may be cyclic via Y, branched or linear.
The inventive compounds may either be in the form of an individual compound having a defined molecular weight or in the form of an oligomer mixture having a molecular weight distribution.
The molar ratio of the alkyl polyether group —O—(R5—O)m—R6 to silicon in the oligomeric organosilane may be >0 and <=2.0, preferably >0.1 and <=1.0. The molar ratio of the alkyl polyether group —O—(R5—O)m—R6 to silicon can be ascertained via the molar proportion of the alkyl polyether group —O—(R5—O)m—R6 and the molar proportion of silicon. The molar proportion of the alkyl polyether group —O—(R5—O)m—R6 can be determined by a 13C NMR spectroscopy method known to those skilled in the art using an internal standard. The internal standard may be dimethyl terephthalate, naphthalene, or further internal standards for NMR spectroscopy known to those skilled in the art. The molar proportion of silicon can be ascertained with the aid of a method known to those skilled in the art for determining the Si content (for example ASTM 6740).
The present invention further provides a process for preparing the inventive oligomeric organosilanes, which is characterized in that, in a first process step, the compounds of the formula I-IV




are oligomerized/polymerized according to the molar ratio in the presence of water at temperatures of 0-150° C., preferably of 20-130° C., more preferably 80-120° C., where Y, G, R, R1, R2, R3, R4, R5, R6, R7, R8, n, m, u, x and z are each as defined above, and R9 is H, F, Cl, Br, I, (C1-C16)alkoxy, preferably methoxy or ethoxy,

and, in a second process step, reacted with an alkyl polyether alcohol of the formula HO—(R5—O)m—R6.

The process according to the invention, in the first and second process steps, can be conducted in the presence of a catalyst. In this case, the catalysts in the first and second process steps may be the same or different. The catalyst can be added here 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, R. Corriu, D. Leclercq, Angew. Chem. 1996, 108, 1524-1540) 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.
Preference is given to conducting homogeneous catalysis with a Lewis acid, for example tetrabutyl orthotitanate, or by nucleophilic methods with ammonium fluoride, or by heterogeneous methods with aluminium oxide. 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)2, Na2CO3, K2CO3, CaCO3, CaO, NaHCO3, KHCO3 or alkoxides such as NaOCH3 or NaOC2H5. Nucleophilic catalysis can be accomplished with any desired fluorides, for example ammonium fluoride, sodium fluoride, potassium fluoride, or any desired tetraalkylammonium fluorides such as tetrabutylammonium fluoride. Acidic catalysis can be effected with dilute aqueous mineral acids or solutions of Lewis acids in water. Catalysis can preferably be effected with dilute aqueous HCl or sulphuric acid, using 0.1 mol % of catalyst based on the amount of silane used.
Very preferably, the catalyst used may be tetrabutyl orthotitanate, KOH, NaOH, ammonium fluoride or HCl.
Especially preferably, HCl may be used as catalyst in the first process step, and tetrabutyl orthotitanate in the second process step.
The process according to the invention can be performed in the presence of a solvent.
The oligomerization/polymerization reaction, in the case of addition of water, is effected with elimination of alcohol, hydrogen halide or hydrogen, and can be conducted here in substance or in an inert organic solvent or mixtures thereof, for example in an aromatic solvent such as chlorobenzene, a halogenated hydrocarbon such as chloroform, methylene chloride, an ether such as diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran or diethyl ether, acetonitrile or carboxylic esters, for example ethyl acetate, methyl acetate or isopropyl acetate, an alcohol, for example methanol, ethanol, n-propanol, i-propanol, n-butanol, sec-butanol or tert-butanol. Preferred solvents here are ethanol or ethyl acetate.
The second process step can be conducted without further addition of a solvent.
The compounds of the formula I may, for example, be 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis(3-[triethoxysilyl]propyl)disulphane, bis(3-[triethoxysilyl]propyl)trisulphane, bis(3-[triethoxysilyl]propyl)tetrasulphane, 3-thiocyanatopropyltrimethoxysilane, 3-thiocyanatopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane,




The compounds of the formula II may, for example, be bis(3-[triethoxysilyl]propyl)disulphane, bis(3-[triethoxysilyl]propyl)trisulphane or bis(3-[triethoxysilyl]propyl)tetrasulphane.
The compounds of the formula III may, for example, be methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane or dichlorodimethylsilane.
The compounds of the formula IV may, for example, be 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis(3-[triethoxysilyl]propyl)disulphane, bis(3-[triethoxysilyl]propyl)trisulphane, bis(3-[triethoxysilyl]propyl)tetrasulphane, 3-thiocyanatopropyltrimethoxysilane, 3-thiocyanatopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane,




On completion of reaction, the volatile constituents can be removed in a manner known to those skilled in the art, preferably by distillation. The catalyst can be deactivated, preferably by neutralization, or removed, preferably by filtration.
The invention further provides for the use of the inventive organosilanes in rubber mixtures.
The invention further provides rubber mixtures comprising the inventive oligomeric organosilanes. The inventive rubber mixtures can be used for production of shaped bodies, especially pneumatic tyres or tyre treads.
The inventive rubber mixtures may comprise rubber, filler, preferably precipitated silica, optionally further rubber auxiliaries, and at least one oligomeric organosilane. The oligomeric organosilanes can be used in amounts of 0.1 to 15% by weight, based on the amount of the rubber used.
The use of the inventive oligomeric organosilanes in rubber blending processes distinctly reduces the unpleasant alcohol release because of the pre-condensation that has already taken place. Compared to the usual mode of operation, for example by simple use of bis(3-[triethoxysilyl]propyl)tetrasulphane (TESPT) as adhesion promoter, evolution of alcohol is reduced during the blending operation.
The addition of the inventive oligomeric organosilanes and the addition of the fillers is preferably effected at mass temperatures of 100 to 200° C., but it can also be effected at a later stage at lower temperatures (40 to 100° C.), 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 silicates, aluminium oxide or carbon blacks.
Fillers used for the inventive rubber mixtures may be:

    
    
        carbon blacks: The carbon blacks for use here are produced by the lamp black, furnace black or gas black process and have BET surface areas of 20 to 200 m2/g, for example SAF, ISAF, HSAF, HAF, FEF or GPF blacks. The carbon blacks may optionally also contain heteroatoms, for example Si.
        Silicas, preferably precipitated silicas, for example prepared by precipitation of solutions of silicates or flame hydrolysis of silicon halides having specific surface areas of 5 to 1000, preferably 20 to 400, m2/g (BET surface area) and having primary particle sizes of 10 to 400 nm. The silicas may optionally also be in the form of mixed oxides with other metal oxides, such as Al oxides, Mg oxides, Ca oxides, Ba oxides, Zn oxides and titanium oxides.
        Synthetic silicates, such as aluminium silicate, alkaline earth metal silicates such as magnesium silicate or calcium silicate, having BET surface areas of 20 to 400 m2/g and primary particle diameters of 10 to 400 nm.
        Natural silicates, such as kaolin and other naturally occurring silicas.
        Glass fibres and glass fibre products (mats, strands) and glass microbeads.
    
    


It is possible with preference to use carbon blacks having BET surface areas of 20 to 400 m2/g or finely divided silicas prepared by precipitation of solutions of silicates, having BET surface areas of 20 to 400 m2/g in amounts of 5 to 150 parts by weight, based in each case on 100 parts of rubber.
The fillers mentioned can be used alone or in a mixture. In a particularly preferred execution of the process, it is possible to use 10 to 150 parts by weight of light-coloured fillers, optionally together with 0 to 100 parts by weight of carbon black, and 0.3 to 10 parts by weight of an inventive oligomeric organosilane, based in each case on 100 parts by weight of rubber, for production of the mixtures.
For the production of inventive rubber mixtures, not only natural rubber but also synthetic rubbers are suitable. Preferred synthetic rubbers are described, for example, in W. Hofmann, Kautschuktechnologie [Rubber Technology], Genter Verlag, Stuttgart 1980. They include

    
    
        polybutadiene (BR)
        polyisoprene (IR)
        styrene/butadiene copolymers having styrene contents of 1 to 60%, preferably 2 to 50%, by weight (SBR)
        isobutylene/isoprene copolymers (IIR)
        butadiene/acrylonitrile copolymers having acrylonitrile contents of 5 to 60%, preferably 10 to 50%, by weight (NBR)
        partly hydrogenated or fully hydrogenated NBR rubber (HNBR)
        ethylene/propylene/diene copolymers (EPDM)

and mixtures of these rubbers. For the production of motor vehicle tyres, anionically polymerized L-SBR rubbers having a glass transition temperature above −50° C. in particular, and mixtures thereof with diene rubbers, are of interest.

    
    


The inventive rubber vulcanizates may comprise further rubber auxiliary products such as reaction accelerators, ageing stabilizers, thermal stabilizers, light stabilizers, antiozonants, processing auxiliaries, plasticizers, tackifiers, blowing agents, dyes, pigments, waxes, extenders, organic acids, retardants, metal oxides, and activators such as triethanolamine, polyethylene glycol, hexanetriol, which are known to the rubber industry.
The rubber auxiliaries are used in customary amounts guided by factors including the end use. Typical amounts are, for example, amounts of 0.1 to 50% by weight based on rubber. The oligomeric organosilanes can serve as crosslinkers alone. In general, it is advisable to add further crosslinkers. Further known crosslinkers used may be sulphur or peroxides. The inventive rubber mixtures may additionally comprise vulcanization accelerators. Examples of suitable vulcanization accelerators are mercaptobenzothiazoles, sulphenamides, guanidines, thiurams, dithiocarbamates, thioureas and thiocarbonates. The vulcanization accelerators and sulphur or peroxides can be used in amounts of 0.1 to 10% by weight, preferably 0.1 to 5% by weight, based on rubber.
The vulcanization of the inventive rubber mixtures can be effected at temperatures of 100 to 200° C., preferably 130 to 180° C., optionally under a pressure of 10 to 200 bar. The blending of the rubbers with the filler, any rubber auxiliaries and the inventive oligomeric organosilanes can be conducted in the customary mixing units, such as rollers, internal mixers and mixing extruders. The inventive rubber vulcanizates are suitable for production of shaped bodies. The inventive rubber mixtures can be used for production of tyres, profiles, cable sheaths, hoses, drive belts, conveyor belts, tyre covers, shoe soles, gasket rings and damping elements.
The invention further provides oligomeric organosilanes obtainable by the process according to the invention.
The inventive oligomeric organosilanes, in rubber mixtures, have the advantage of improved processibility and/or improved tear resistance.
The SH—(mercapto), S2—(disulphane), S3—(trisulphane), Sx—(polysulphane with x>3) distribution can be determined using 1H NMR spectroscopy, which is known to those skilled in the art.
The molar proportion of SiOEt and SiOR groups can be determined by 13C NMR spectroscopy, which is known to those skilled in the art.
In addition, the monomer content, and also M, D and T structures, can be determined using 29Si NMR spectrometry, which is likewise well known to the person skilled in the art.
Molar masses and the molar mass distribution can be determined by means of gel permeation chromatography (GPC). The GPC analysis method is described in detail in references including “Modern Size-Exclusion Liquid Chromatography”, Andre Striegel et al., Wiley & Sons, 2nd ed. 2009. This involves using, as a standard for calibration of the method for siloxane analyses, a mixture of siloxanes of vinyltrimethoxysilane (vinyltrimethoxysilane, divinyltetramethoxydisiloxane, trivinylhexamethoxytrisiloxane, tetravinyloctamethoxytetrasiloxane). Columns used (MZ-Analysetechnik): Columns: 50×8.0 mm, MZ-Gel SDplus (styrene/divinylbenzene copolymer with high crosslinking level, spherical particle shape), porosity 50 A (angstroms, Å), 5 μm (micrometers) (pre-column), 300×8.0 mm, MZ-Gel SDplus, porosity 100 A (angstroms, Å), 5 μm, 300×8.0 mm, MZ-Gel SDplus, porosity 500 A (angstroms, Å), 5 μm; eluent and pump flow rate: methyl ethyl ketone (MEK) at 1 ml/min, standard substance: internal standard—1 g/1 ethylbenzene in 1% sample solution. The instrument is calibrated beforehand against a suitable substance (monomer, dimer, trisiloxane, etc.). Instrument (Agilent): 1100 Series isocratic pump G1310A, 1100 Series column oven G1316A, 1100 Series RID detector G1362A, manual injector G1328A, vacuum degasser G1322A, GPC software (PSS WinGPC Unity).


EXAMPLES
Octyltriethoxysilane, propyltriethoxysilane, Dynasylan® 9265 (phenyltriethoxysilane), Si 690® (bis(triethoxysilylpropyl) tetrasulphide) and VP Si 263® (3-mercaptopropyltriethoxysilane) are silanes from Evonik Industries.
Marlosol is a polyether alcohol of the formula HO—(R5—O)m—R6 where R5═CH2CH2, R6═C13H27 and m=5 from Sasol.
Example 1
Preparation from VP Si 263®/octyltriethoxysilane/Marlosol (1:0.5:0.5)-0.8 eq H2O.
A stirred apparatus is initially charged with VP Si 263® (417 g) and octyltriethoxysilane (242 g) and heated to 85° C. A mixture of H2O (38 g) and conc. HCl (0.3 g, 37%) in EtOH (363 g) is added dropwise and then the mixture is stirred for 8.5 h. After the oligomerization reaction has ended, the solvent and alcohol formed in the hydrolysis are removed under reduced pressure. Marlosol (368 g) and tetra-n-butyl titanate (0.5 g) are added and the reaction is heated to 140° C. for 1 h. The EtOH formed is removed by distillation under reduced pressure. The bottom product (793 g, 95% of theory) is a viscous orange liquid.
Density (20° C.): 1.012 g/cm3 
29Si NMR: 3% silane (VP Si 263®, octyltriethoxysilane), 49% M structures, 40% D structures, 9% T structures
GPC: Mn=967 g/mol, Mw=1234, Mz=1536, PDI=1.2761
Molar ratio of the alkyl polyether group —O—(R5—O)m—R6 to silicon=0.33
Example 2
Preparation from VP Si 2630®/propyltriethoxysilane/Marlosol (1:0.5:0.5)-0.8 eq H2O
A stirred apparatus is initially charged with VP Si 2630® (417 g) and propyltriethoxysilane (181 g) and heated to 85° C. A mixture of H2O (38 g) and conc. HCl (0.3 g, 37%) in EtOH (363 g) is added dropwise and then the mixture is stirred for 8 h. After the oligomerization reaction has ended, the solvent and alcohol formed in the hydrolysis are removed under reduced pressure. Marlosol (368 g) and tetra-n-butyl titanate (0.5 g) are added and the reaction is heated to 140° C. for 1 h. The EtOH formed is removed by distillation under reduced pressure. The bottom product (751 g, 94% of theory) is a viscous colourless liquid.
Density (20° C.): 1.029 g/cm3 
13C NMR: 78.6 mol % SiOEt, 21.4 mol % SiOR
29Si NMR: <1% silane (VP Si 263®, propyltriethoxysilane), 60% M structures, 35% D structures, 4% T structures
GPC: Mn=757 g/mol, Mw=1066, Mz=1417, PDI=1.4082
Molar ratio of the alkyl polyether group —O—(R5—O)m—R6 to silicon=0.33
Example 3
Preparation from VP Si 263®/phenyltriethoxysilane (Dynasylan® 9265)/Marlosol (1:0.5:0.5)-0.8 eq H2O
A stirred apparatus is initially charged with VP Si 263® (417 g) and Dynasylan® 9265 (210 g) and heated to 88° C. A mixture of H2O (38 g) and conc. HCl (0.3 g, 37%) in EtOH (363 g) is added dropwise and then the mixture is stirred for 6 h. After the oligomerization reaction has ended, the solvent and alcohol formed in the hydrolysis are removed under reduced pressure. Marlosol (368 g) and tetra-n-butyl titanate (0.5 g) are added and the reaction is heated to 140° C. for 1 h. The EtOH formed is removed by distillation under reduced pressure. The bottom product (797 g, 99% of theory) is a viscous, pale yellow liquid.
Density (20° C.): 1.050 g/cm3 
29Si NMR: 3% VP Si 263®, 1% Dynasylan® 9265, 51% M structures, 37% D structures, 8% T structures
GPC: Mn=770 g/mol, Mw=1013, Mz=1300, PDI=1.3156
Molar ratio of the alkyl polyether group —O—(R5—O)m—R6 to silicon=0.33
Example 4
Inventive: Preparation from VP Si 263®/Si 69®/Marlosol (1:0.5:0.5)-0.8 eq H2O
A stirred apparatus is initially charged with VP Si 263® (417 g) and Si 69® (466 g) and heated to 98° C. A mixture of H2O (38 g) and conc. HCl (0.3 g, 37%) in EtOH (363 g) is added dropwise and then the mixture is stirred for 8 h. After the oligomerization reaction has ended, the solvent and alcohol formed in the hydrolysis are removed under reduced pressure. Marlosol (368 g) and tetra-n-butyl titanate (0.5 g) are added and the reaction is heated to 140° C. for 1 h. The EtOH formed is removed by distillation under reduced pressure. The bottom product (1028 g, 98% of theory) is a viscous yellow liquid.
Density (20° C.): 1.082 g/cm3 
1H NMR: 40 mol % SH, 22 mol % S2, 27 mol % S3, 11 mol % Sx
13C NMR: 87.5 mol % SiOEt, 22.5 mol % SiOR
29Si NMR: 9% silane, 72% M structures, 19% D structures
GPC: Mn=1317 g/mol, Mw=5501, Mz=12291, PDI=4.1778
Molar ratio of the alkyl polyether group —O—(R5—O)m—R6 to silicon=0.33
Comparative Example 5
Reference according to EP 0964021: Preparation from Si 69®/PTEO (1:5)-0.8 eq H2O
A stirred apparatus is initially charged with Si 69® (240 g) and PTEO (464 g) and heated to 75° C. A mixture of H2O (45 g) and conc. HCl (0.5 g, 37%) in EtOH (436 g) is added dropwise and then the mixture is stirred for 12 h. After the oligomerization reaction has ended, the solvent and alcohol formed in the hydrolysis are removed under reduced pressure. The bottom product (518 g, >99% of theory) is a viscous yellow liquid.
29Si NMR: 0% silane PTEO, 0.4% silane Si 69®, 1% M structures of PTEO, 69% M structures of Si 69+D structures of PTEO, 28% D structures of Si 69®+T structures of PTEO, 1% T structures of Si 69®
GPC: Mn=871 g/mol, Mw=1473, Mz=2337, PDI=1.6916
Example 6
The formulation used for the rubber mixtures is specified in Table 1 below. In this table, the unit phr means parts by weight based on 100 parts by weight of the raw rubber used. The oligomeric silanes are used in isomolar amounts, based on the silane used in situ. The mixtures are prepared in a 1.5 l mixer (E type) at a batch temperature of 155° C.














TABLE 1









Amount







Amount

[phr]
Amount
Amount
Amount



Amount
[phr]
Amount
Inv.
[phr]
[phr]
[phr]



[phr]
Ref.
[phr]
rubber
Inv.
Inv.
Inv.



Ref.
rubber
Ref.
mixture
rubber
rubber
rubber



rubber
mixture
rubber
I,
mixture
mixture
mixture



mixture I
II,
mixture
cont.
II,
III,
IV,



“in
“in
III,
inv.
cont.
cont.
cont.


Substance
situ”
situ”
comp. ex. 5
ex. 1
inv. ex. 2
inv. ex. 3
inv. ex. 4






















1st stage









Buna VSL
96.25
96.25
96.25
96.25
96.25
96.25
96.25


5025-2


Buna CB 24
30
30
30
30
30
30
30


Ultrasil
80
80
80
80
80
80
80


7000 GR


ZnO RS
2
2
2
2
2
2
2


Edenor ST1
1
1
1
1
1
1
1


Vivatec 500
8.75
8.75
8.75
8.75
8.75
8.75
8.75


Rhenogran
2.5
2.5
2.5
2.5
2.5
2.5
2.5


DPG-80


Protector
2
2
2
2
2
2
2


G 3108


Vulkanox-
2
2
2
2
2
2
2


4020/LG


Vulkanox-
1.5
1.5
1.5
1.5
1.5
1.5
1.5


HS/LG


Aktiplast
3.5
3.5
3.5
3.5
3.5
3.5
3.5


ST


Si 69 ®
6.4
—
—
—
—
—
—


VP Si 363 ®
—
10
—
—
—
—
—


Reference
—
—
3.1
—
—
—
—


silane


according


to comp.


ex. 5


Inv. silane
—
—
—
6.0
—
—
—


according


to


ex. 1


Inv. silane
—
—
—
—
5.6
—
—


according


to


ex. 2


Inv. silane
—
—
—
—
—
5.8
—


according


to


ex. 3


Inv. silane
—
—
—
—
—
—
7.3


according


to


ex. 4


2nd stage


Batch


Stage 1


3rd stage


Batch


Stage 2


Perkacit
0.2
0.2
0.2
0.2
0.2
0.2
0.2


TBzTD


Vulkacit
1.6
1.6
1.6
1.6
1.6
1.6
1.6


CZ/EG-C


Sulphur
2.1
2.1
2.1
2.1
2.1
2.1
2.1









The polymer VSL 5025-2 is a solution-polymerized SBR copolymer from Bayer AG, having a styrene content of 25% by weight and a vinyl fraction of 50% by weight. The copolymer contains 37.5 phr TDAE oil and has a Mooney viscosity (ML 1+4/100° C.) of 47.
The polymer Buna CB 24 is a cis-1,4-polybutadiene (neodymium type) from Bayer AG, having a cis-1,4 content of at least 96% and a Mooney viscosity of 44±5.
Ultrasil 7000 GR is a readily dispersible silica from Evonik Industries AG and has a BET surface area of 170 m2/g.
The TDAE oil used is Vivatec 500 from Klaus Dahleke KG, Vulkanox 4020 is 6PPD from Lanxess Europe GmbH & Co. KG, Vulkanox HS/LG is TMQ from Lanxess and Protektor G3108 is an antiozonant wax from Paramelt B.V.; ZnO RS is ZnO from Arnsperger Chemikalien GmbH; EDENOR ST1 GS 2.0 is palmitic/stearic acid from Caldic Deutschland GmbH & Co. KG; Aktiplast ST is a plasticizer from RheinChemie, which consists of a blend of hydrocarbons, zinc soaps and fillers. Rhenogran DPG-80 consists of 80% DPG on an EVA/EPDM carrier from RheinChemie, and Vulkacit CZ is CBS from Lanxess Europe GmbH & Co. KG. Perkacit TBzTD (tetrabenzylthiuram disulphide) is a product from Flexsys N.V.
The rubber mixture is produced in three stages in an internal mixer according to Table 2.







TABLE 2







Stage 1










Settings




Mixing unit
Werner & Pfleiderer GK 1.5E



Speed
80 min−1



Ram pressure
5.5 bar



Flow temp.
80° C.



Mixing process



0 to 0.5 min
Buna VSL 5025-1 + Buna CB 24



0.5 min
TMQ, 6PPD



0.5 bis 1 min
mix



1 to 2 min
1⁄2 Ultrasil 7000 GR, silane or oligomeric




organosilanes, ZnO



2 min
clean and ventilate



2 to 3 min
1⁄2 Ultrasil 7000 GR, Protector G3108,




stearic acid, Vivatec 500, DPG,




plasticizer



3 min
clean and ventilate



3 to 4 min
mix and discharge at 150-160° C.







Stage 2










Settings




Mixing unit
as in stage 1 except:



Speed
90 min−1



Mixing process



0 to 1 min
break up stage 1 batch



1 to 3 min
mix at 155° C.



3 min
discharge







Stage 3










Settings




Mixing unit
as in stage 1 except



Speed
40 min−1



Flow temp.
50° C.



Mixing process



0 to 0.5 min
stage 2 batch



0.5 to 2 min
accelerator and sulphur



2 min
discharge and form milled sheet on




laboratory roll mill




(diameter 200 mm, length 450 mm,




flow temperature 50° C.)




Homogenize:




form a milled sheet with roll gap 3-4 mm




for 20 s, and within a further 40 s: cut




and fold over 3* to the left, 3* to the




right and




roll 3* with a narrow roll gap (3 mm) and




then draw off a milled sheet.



Batch temp.
<110° C.










The general process for producing rubber mixtures and vulcanizates thereof is described in “Rubber Technology Handbook”, W. Hofmann, Hanser Verlag 1994.
The rubber testing is effected by the test methods specified in Table 3.










TABLE 3







Physical testing
Standard/conditions









Moving die method: minimum torque
DIN 53529/3, ISO 6502



Ring tensile test, 23° C.
DIN 53504, ISO 37



Stress values



DIN abrasion
DIN ISO 4649, ISO 4649



Shore hardness
DIN 53505, ISO 7619-1



Tear resistance, die C
ASTM D 624



Ball rebound, 70° C.
ASTM D 2632



Viscoelastic properties
DIN 53 513, ISO 2856



0 and 60° C., 16 Hz, initial force



50 N and amplitude force 25 N



Complex modulus E* (MPa)










The vulcanization is effected at a temperature of 165° C. for a period of 15 minutes. Table 4 reports the rubber data for raw mixture and vulcanizate.














TABLE 4









Inv.









rubber
Inv.
Inv.
Inv.



Ref.
Ref.
Ref.
mixture
rubber
rubber
rubber



rubber
rubber
rubber
I,
mixture
mixture
mixture



mixture I
mixture
mixture
cont.
II,
III,
IV,



“in
II,
III,
inv.
cont.
cont.
cont.


Substance
situ”
“in situ”
comp. ex. 5
ex. 1
inv. ex. 2
inv. ex. 3
inv. ex. 4






















Crude mixture









results:


Moving die
2.3

2.9
2.1
2.7
2.1
1.9


method:


minimum


torque after


3rd stage


[dNm]


Vulcanizate


results:


50% stress
1.2

1.05
1.15
1.2
1.1
1.1


value [mPa]


200% stress
7.2

4.8
8.9
9.2
8.3
7.6


value [mPa]


Strengthening
6.0

4.6
7.7
7.7
7.5
6.9


index:


200%/50%


stress value


[—]


DIN abrasion
95
105
104
67
61
69
72


[mm3]


Shore
60
55
60
56
58
55
58


hardness


Ball rebound,
65.0
68.8
63.0
72.1
71.6
70.8
70.1


70° C. [%]


Tear
40.2
49
33.4
36.7
44.4
40.7
37.5


resistance,


die C [N/mm]


MTS, 16 Hz,
0.454
0.412
0.476
0.449
0.478
0.462
0.474


initial force


50 N, ampl.


force 25 N,


0° C. [MPa]


MTS, 16 Hz,
0.109
0.108
0.130
0.087
0.093
0.093
0.096


initial force


50 N, ampl.


force 25 N,


60° C. [MPa]









The rubber mixtures containing the inventive oligomeric silanes show improved processing characteristics (lower torque after the 3rd mixing stage), improved strengthening characteristics (higher moduli and better reinforcement index), improved rolling resistance and improved tear resistance compared to the isomolar in situ mixture or the oligomeric silane according to EP 0964021.

## Claims

1. An oligomeric organosilane, comprising structural unit A and at least one structural unit selected from structural units B, C and D joined in a linear, branched or cyclic arrangement;



wherein:
Y represents H, F, Cl, Br, I, SCN, SH, —Sx—(CH2)nSiRR1R2 or —N(R8)2;
R8 independently represents H, (C1-C16) alkyl, —(CH2)2NH2, —(CH2)2NH—(CH2)2NH2 or —(CH2)2N[(CH2)2NH2]2;
n represents 1-8;
G represents H, F, Cl, Br, I, SCN, SH, —Sx—(CH2)nSiRR1R2 or —N(R8)2, such that G is different from Y;
R, R1, R2, R3, R4, each independently represent OH, (C1-C16)alkyl, (C2-C16)alkenyl, (C6-C14)aryl, (C1-C4)alkoxy, an OSiR1R2R3 group or an alkyl polyether group —O—(R5—O)m—R6;
R5 independently represents a branched or unbranched, saturated or unsaturated, aliphatic divalent C1-C30 hydrocarbon group;
m on average is 1 to 30;
R6 represents an unsubstituted or substituted, branched or unbranched C1-C30 alkyl group, C2-C30 alkenyl group, a C6-C14 aryl group, or a C7-C40 aralkyl group;
R7 represents an alkyl polyether group —O—(R5—O)m—R6;
x on statistical average is 1-6; and
z on statistical average is 1-6.

2. The oligomeric organosilane of claim 1, wherein an molecular weight of the oligomeric organosilane is between 400 and 100,000 g/mol.

3. The oligomeric organosilane of claim 1, wherein:
the oligomeric organosilane comprises the structural units A and B and C; and
R7 represents the alkyl polyether group —O—(R5—O)m—R6.

4. The oligomeric organosilane of claim 3, wherein;
in structural unit A,
n represents 3, and
Y represents SH;

in structural unit B,
R1 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6,
R2 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6,
n represents 3, and
z represents 2-4; and

in structural unit C,
R represents phenyl, propyl or octyl, and
R3 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6.

5. The oligomeric organosilane of claim 1, wherein:
the oligomeric organosilane comprises the structural units A and B; and
R7 represents the alkyl polyether group —O—(R5—O)m—R6.

6. The oligomeric organosilane of 5, wherein:
in structural unit A,
n represents 3, and
Y represents SH; and

in structural unit B,
R1 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6,
R2 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6,
n represents 3, and
z represents 2-4.

7. The oligomeric organosilane of claim 1, wherein:
the oligomeric organosilane comprises the structural units A and D; and
R7 represents the alkyl polyether group —O—(R5—O)m—R6.

8. The oligomeric organosilane of claim 7, wherein:
in structural unit A,
n represents 3, and
Y represents SH; and

in structural unit D,
G represents Cl or NH2,
n represents 3, and

R4 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6.

9. The oligomeric organosilane of claim 1, wherein:
the oligomeric organosilane comprises the structural units A and C and D,
R7 represents the alkyl polyether group —O—(R5—O)m—R6.

10. The oligomeric organosilane of claim 9, wherein:
in structural unit A,
n represents 3, and
Y represents SH;

in structural unit C,
R represents phenyl, propyl or octyl, and
R3 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6; and

in structural unit D,
G represents Cl or NH2,
R4 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6, and
n represents 3.

11. The oligomeric organosilane of claim 1, wherein:
the oligomeric organosilane comprises the structural units A and C; and
R7 represents the alkyl polyether group —O—(R5—O)m—R6.

12. The oligomeric organosilane of claim 11, wherein:
in structural unit A,
n represents 3, and
Y represents SH; and

in structural unit C,
R represents phenyl, propyl or octyl, and
R3 represents ethoxy or alkyl polyether group —O—(R5—O)m—R6.

13. A process for preparing the oligomeric organosilane of claim 1, the process comprising:
oligomerizing/polymerizing the compound of formula I and at least one of the compounds of formulae II-IV:





in the presence of water at temperatures of 0-150° C., to form an intermediate; and
reacting the intermediate with an alkyl polyether alcohol of formula HO—(R5—O)m—R6, to form the oligomeric organosilane,
wherein:
Y, G, R, R1, R2, R3, R4, R5, R6, R7, R8, n, m, u, x and z are each as defined in claim 1; and
R9 independently represents H, F, Cl, Br, I, or (C1-C16)alkoxy.

14. The process of claim 13, wherein the oligomerizing/polymerizing, the reacting, or both, occurs in the presence of a catalyst.

15. The process of claim 14, wherein:
the oligomerizing/polymerizing occurs in the present of HCl as catalyst; and
the reacting occurs in the present of tetrabutyl orthotitanate as catalyst.

16. The process of claim 13, wherein the oligomerizing/polymerizing, the reacting, or both, occurs in the presence of a solvent which is ethyl acetate or ethanol.

17. A rubber mixture, comprising the oligomeric organosilane of claim 1.

18. A tire, profile, cable sheath, hose, drive belt, conveyor belt, tyre cover, shoe sole, gasket ring or damping element comprising the rubber mixture of claim 17.

19. An oligomeric organosilane obtained by the process of claim 13.

20. An oligomeric organosilane, comprising structural unit D and at least one structural unit selected from structural units A, B and C, joined in a linear, branched or cyclic arrangement:



wherein:
Y represents H, F, Cl, Br, I, SCN, SH, —Sx—(CH2)nSiRR1R2 or —N(R8)2;
R8 independently represents H, (C1-C16) alkyl, —(CH2)2NH2, —(CH2)2NH—(CH2)2NH2 or —(CH2)2N[(CH2)2NH2]2;
n represents 1-8;
G represents H, F, Cl, Br, I, SCN, SH, —Sx—(CH2)nSiRR1R2 or —N(R8)2, such that G is different from Y;
R, R1, R2, R3, R4, R7 each independently represent OH, (C1-C16)alkyl, (C2-C16)alkenyl, (C6-C14)aryl, (C1-C4)alkoxy, an OSiR1R2R3 group or an alkyl polyether group —O—(R5—O)m—R6;
R5 independently represents a branched or unbranched, saturated or unsaturated, aliphatic divalent C1-C30 hydrocarbon group;
m on average is 1 to 30;
R6 represents an unsubstituted or substituted, branched or unbranched C1-C30 alkyl group, C2-C30 alkenyl group, a C6-C14 aryl group, or a C7-C40 aralkyl group;
x on statistical average is 1-6;
z on statistical average is 1-6; and
at least one R, R1, R2, R3, R4 or R7 group is an alkyl polyether group —O—(R5—O)m—R6.

21. A process for preparing the oligomeric organosilane of claim 20, the process comprising:
oligomerizing/polymerizing the compound of formula IV and at least one of the compounds of formulae I-III:





in the presence of water at temperatures of 0-150° C., to form an intermediate; and
reacting the intermediate with an alkyl polyether alcohol of formula HO—(R5—O)m—R6, to form the oligomeric organosilane,
wherein:
Y, G, R, R1, R2, R3, R4, R5, R6, R7, R8, n, m, u, x and z are each as defined in claim 20; and
R9 independently represents H, F, Cl, Br, I, or (C1-C16)alkoxy.