Urea-containing silanes, process for preparation thereof and use thereof

1. A urea-containing silane of formula I

where each R 1 is independently selected from the group consisting of a C1-C10 alkoxy group, a C2-C10 cyclic dialkoxy group, a phenoxy group, a C4-C10 cycloalkoxy group, a C6-C20 aryl group, a C1-C10 alkyl group, a C2-C20 alkenyl group, a C7-C20 aralkyl group or a halogen, and each R is independently a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30 hydrocarbon group.

2. The urea-containing silane according to claim 1 wherein the urea-containing silane is

((EtO) 3 Si—CH 2 —NH—CO—NH—CH 2 ) 2 S,

((EtO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 ) 2 S,

((EtO) 3 Si—CH 2 —NH—CO—NH—CH 2 CH 2 ) 2 S,

((EtO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 ) 2 S,

((EtO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 ) 2 S,

((EtO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 ) 2 S,

((EtO) 3 Si—CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 ) 2 S,

((EtO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 ) 2 S,

((EtO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 ) 2 S,

((MeO) 3 Si—CH 2 —NH—CO—NH—CH 2 ) 2 S,

((MeO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 ) 2 S,

((MeO) 3 Si—CH 2 —NH—CO—NH—CH 2 CH 2 ) 2 S,

((MeO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 ) 2 S,

((MeO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 ) 2 S,

((MeO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 ) 2 S,

((MeO) 3 Si—CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 ) 2 S,

((MeO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 ) 2 S or

((MeO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 ) 2 S.

3. The urea-containing silane according to claim 1 , wherein the urea-containing silane is

(EtO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 —S—CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 —Si(OEt) 3 .

4. A process for preparing the urea-containing silane of claim 1 , wherein, in a first step, an aminosilane of formula II

is reacted with an isocyanate of formula III

where R and R 1 are each as defined in claim 1 and Hal is F, Cl, Br or I,

and, in a second step, the product from the first step is reacted with a sodium sulphide of formula (IV)

Na 2 S  (IV).

5. The process of claim 4 , wherein the first step is conducted under a protective gas atmosphere.

6. The process of claim 4 , wherein the second step is conducted under a protective gas atmosphere.

7. The process of claim 4 , wherein the first step is conducted at temperatures between −78° C. and 100° C.

8. The process of claim 4 , wherein the second step is conducted at temperatures between 20° C. and 150° C.

9. The process of claim 4 , wherein ethanol is used as solvent in the first step.

10. The process of claim 4 , wherein ethanol is used as solvent in the second step.

11. The process of claim 9 , wherein the ethanol is distilled off after the first step.

12. The process of claim 10 , wherein the ethanol is distilled off after the second step.

13. A process of for preparing the urea-containing silane of claim 1 , wherein, in a first step, an isocyanatosilane of formula VI

is reacted with an amine of formula VII

where R and R 1 are each as defined in claim 1 and Hal is F, Cl, Br or I,

and, in a second step, the product from the first step is reacted with sodium sulphide of the formula (IV)

Na 2 S  (IV).

14. The process of claim 13 , wherein the amine of formula VII, prior to reaction with the isocyanatosilane of formula VI, is prepared from a hydrochloride salt of a diamine of formula VIII

Cl −+ H 3 N—R—S—S—R—NH 3 + Cl −   (VIII)

by addition of a base.

15. The process of claim 14 , wherein the base is NaOEt.

16. The process of claim 13 , wherein the product is dried.