Oligomeric organosilanepolysufanes, their use in rubber mixtures and for preparing molded articles

Oligomeric organosilanepolysulfanes containing at least one structural unit selected from the group consisting of structural units A, B and C linked in any linear, branched or cyclic arrangement,

• wherein Y=H, CN, —(CH2)nSiRR1R2;
• n=1-8,
• R, R1, R2 and R3, independently, represent H, (C1-C4)alkyl, (C1-C4)alkoxy, halogen or a OSiR1R2R3 group;
• n is 1-8,
• o, p and q are each a whole, positive number between 1 and 40 where o+p+q may be ≧2 and <40, with the proviso that at least one structural unit A or B is present,
• wherein the organosilanepolysulfane contains 50 to 85% of the two structural units A and B in which Y=—(CH2)nSiRR1R2, R=R1=R2=ethoxy, n=3, and
• wherein x and z, as a statistical average, are 2-4.

A process for preparing oligomeric organosilanepolysulfanes containing at least one structural unit selected from the group consisting of structural units A, B and C linked in any linear, branched or cyclic arrangement,

• wherein Y=H, CN, —(CH2)nSiRR1R2;
• n=1-8,
• R, R1, R2 and R3, independently, represent H, (C1-C4)alkyl, (C1-C4)alkoxy, halogen or a OSiR1R2R3 group;
• n is 1-8,
• o, p and q are each a whole, positive number between 1 and 40 where o+p+q may be ≧2 and <40, with the proviso that at least one structural unit A or B is present,
• wherein the organosilanepolysulfane contains 50 to 85% of the two structural units A and B in which Y=—(CH2)nSiRR1R2, R=R1=R2=ethoxy, n=3, wherein x and z, as a statistical average, are 2-4, comprising:
• copolymerizing a compound of the structural type (I)
• in which Y=H, CN, —(CH2)nSiRR1R2;
• R, R1 and R2, independently, represent H, (C1-C4)alkyl, (C1-C4)alkoxy, halogen or a OSiR1R2R3 group and x, as a statistical average, may be 1 to 6, optionally in a solvent and/or optionally with the aid of a catalyst,
• at a reaction temperature between 0° C. and 150° C. and with the addition of water,
• with a compound of the structural type II
• RR1R2R3Si (II)
• in which R, R1, R2 and R3, independently, represent H, (C1-C4)alkyl, (C1-C4)alkoxy, halogen or a OSiR1R2R3 group,
• wherein the compound of structural type (I) is bis(3-{triethoxysilyl}-propyl)tetrasulfane and the compound of structural type (II) is propyltriethoxysilane or dimethylethoxysilane.

Rubber mixtures comprising an oligomeric organosilanepolysulfane containing at least one structural unit selected from the group consisting of structural units A, B and C linked in any linear, branched or cyclic arrangement,

• wherein Y=H, CN, —(CH2)nSiRR1R2;
• n=1-8,
• R, R1, R2 and R3, independently, represent H, (C1-C4)alkyl, (C1-C4)alkoxy, halogen or a OSiR1R2R3 group;
• x, as a statistical average, is 1-6,
• z, as a statistical average, is 2-6,
• n is 1-8, and
• o, p and q are each a whole, positive number between 1 and 40 where o+p+q may be ≧2 and <40, with the proviso that at least one structural unit A or B is present,
• wherein the organosilanepolysulfane contains 50 to 85% of structural units A and B in which Y=—(CH2)nSiRR1R2, wherein R=R1=R2=ethoxy and n=3 and in which x and y, as a statistical average, are 2 to 4.

Rubber mixtures comprising an oligomeric organosilanepolysulfane containing at least one structural unit selected from the group consisting of structural units A, B and C linked in any linear, branched or cyclic arrangement,

• wherein Y=H, CN, —(CH2)nSiRR1R1R2;
• n=1-8,
• R, R1, R2 and R3, independently, represent H, (C1-C4)alkyl, (C1-C4)alkoxy, halogen or a OSiR1R2R3 group;
• x, as a statistical average, is 1-6,
• z, as a statistical average, is 2-6,
• n is 1-8, and
• o, p and q are each a whole, positive number between 1 and 40 where o+p+g may be ≧2 and <40, with the proviso that at least one structural unit A or B is present,
• the rubber mixtures comprising a synthetic rubber, a silica as filler and the oligomeric organosilanepolysulfane, which has been obtained by polymerization of bis-(3-[triethoxysilyl]-propyl)tetrasulfane or by copolymerization of bis-(3-[triethoxysilyl]-propyl)tetrasulfane and propyltriethoxysilane.