Process for preparing urea-containing silanes
View Patent ↗The invention relates to a process for preparing urea-containing silanes of the general formula I wherein a diamine of the general formula II H 2 N—R—S—S—R—NH 2 (II) is reacted with isocyanatosilane of the general formula III (R 1 ) 3 Si—R—NCO (III) in water.
1. A process for preparing 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, the process comprising
reacting a diamine of formula II
H 2 N—R—S—S—R—NH 2 (II)
with an isocyanatosilane of formula III
(R 1 ) 3 Si—R—NCO (III)
in water.
2. The process of claim 1 , wherein the urea-containing silane is
((EtO) 3 Si—CH 2 —NH—CO—NH—CH 2 —S) 2 ,
((EtO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 —S) 2 ,
((EtO) 3 Si—CH 2 —NH—CO—NH—CH 2 CH 2 —S) 2 ,
((EtO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 —S) 2 ,
((EtO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 —S) 2 ,
((EtO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 —S) 2 ,
((EtO) 3 Si—CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 —S) 2 ,
((EtO) 3 Si—CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 —S) 2 or
((EtO) 3 Si—CH 2 CH 2 CH 2 —NH—CO—NH—CH 2 CH 2 CH 2 —S) 2 .
3. The process of claim 1 , wherein the reaction is conducted without organic solvent.
4. The process of claim 1 , wherein the amount of water in the reaction is greater than 1% by weight, based on the diamines of the general formula II used.
5. The process of claim 1 , wherein the temperature of the reaction is between 0° C. and +100° C.
6. The process of claim 1 , wherein the diamines of the formula II, prior to reaction with the isocyanatosilanes of formula III, are prepared by adding a base to a hydrohalide salt of a diamine of formula IV
Hal − +H 3 N—R—S—S—R—NH 3 + Hal − (IV).
7. The process of claim 6 , wherein the base is NaOH or KOH.
8. The process of claim 6 , wherein the base is added until a pH between 7 and 14 is established.
9. The process of claim 1 , wherein the diamines of formula II are used relative to isocyanatosilanes of formula Ill in a molar ratio of 1:1.80 to 1:2.25.
10. The process of claim 1 , wherein a reaction product is subsequently filtered off and washed with water and/or organic solvent.
11. The process of claim 10 , wherein the product is further dried.