Biuret compounds for rheology control
The invention relates to biuret compounds of the idealized general formula in which R 1 is a (C 1 -C 22 )-alkylene, (C 3 -C 22 )-alkenylene, (C 5 -C 15 )-cycloalkylene, arylene, (C 7 -C 12 )-aralkylene, a polyoxyalkylene radical or is a polyester radical, R 2 is a (C 1 -C 22 )-alkyl, hydroxy-(C 1 -C 22 )-alkyl, (C 3 -C 18 )-alkenyl, aryl, (C 7 -C 12 )-aralkyl, or (C 5 -C 12 )-cycloalkyl radical, a hydroxy-, (C 1 -C 22 )-alkoxy-, (C 5 -C 12 )-cycloalkoxy-, or (C 7 -C 12 )-aralkoxy-polyoxyalkylene radical, or a polyester radical prepared starting from a (C 1 -C 22 )-alkanol, (C 5 -C 12 )-cycloalkanol, or (C 7 -C 12 )-aralkanol or from a (C 1 -C 22 )-alkoxy-, (C 6 -C 12 )-cycloalkoxy-, or (C 7 -C 12 )-aralkoxy-polyoxyalkylene, Y stands for identical or different radicals O, NH, CO—NH—NH or NH—NH—CO, R 3 , R 4 and R 5 independently of one another are a (C 2 -C 40 )-alkylene, (C 3 -C 40 )-alkenylene, (C 5 -C 40 )-cyclo-alkylene, arylene, (C 7 -C 40 )-aralkylene or polyoxy-alkylene radical or are a polyester radical, R 6 is a (C 1 -C 30 )-alkyl, (C 3 -C 22 )-alkenyl, hydroxyalkyl and hydroxyalkenyl, (C 4 -C 13 )-cycloalkyl, aryl or (C 7 -C 12 )-aralkyl radical, Z stands for one or more of the following groups COO, OCO, NHCO, CONH, NHCOO, OOCNH and NHCONH, and a is a number from 1 to 19, and also to processes for preparing them and to their use for rheology control and for thixotroping coating systems, as anti-sag agents and/or as anti-settling agents.
1. A biuret compound of the general formula
in which
R 1 is a (C 1 -C 22 )-alkylene, (C 3 -C 22 )-alkenylene, (C 5 -C 15 )-cycloalkylene, arylene, (C 7 -C 12 )-aralkylene, a polyoxyalkylene radical or is a polyester radical,
R 2 is a (C 1 -C 22 )-alkyl, hydroxy-(C 1 -C 22 )-alkyl, (C 3 -C 18 )-alkenyl, aryl, (C 7 -C 12 )-aralkyl, or (C 5 -C 12 )-cycloalkyl radical, a hydroxy-, (C 1 -C 22 )-alkoxy-, (C 5 -C 12 )-cycloalkoxy-, or (C 7 -C 12 )-aralkoxy-polyoxyalkylene radical, or a polyester radical prepared starting from a (C 1 -C 22 )-alkanol, (C 5 -C 12 )-cycloalkanol, or (C 7 -C 12 )-aralkanol or from a (C 1 -C 22 )-alkoxy-, (C 6 -C 12 )-cycloalkoxy-, or (C 7 -C 12 )-aralkoxy-polyoxyalkylene,
Each Y is independently selected from the group consisting of O, NH, CO—NH—NH and NH—NH—CO,
R 3 , R 4 and R 5 independently of one another are a (C 2 -C 40 )-alkylene, (C 3 -C 40 )-alkenylene, (C 5 -C 40 )-cycloalkylene, arylene, (C 7 -C 40 )-aralkylene or polyoxyalkylene radical or are a polyester radical,
R 6 is a (C 1 -C 30 )-alkyl, (C 3 -C 22 )-alkenyl, hydroxyalkyl and hydroxyalkenyl, (C 4 -C 13 )-cycloalkyl, aryl or (C 7 -C 12 )-aralkyl radical,
Each Z is independently selected from the group consisting of COO, OCO, NHCO, CONH, NHCOO, OOCNH and NHCONH, and
a is a number from 1 to 19.
2. A biuret compound according to claim 1 , wherein R 1 is a hexamethylene radical.
3. A biuret compound according to claim 1 wherein R 2 is a (C 1 -C 22 )-alkyl or a -alkoxypolyoxyalkylene radical.
4. A biuret compound according to claim 1 , wherein the radicals R 3 and R 5 independently of one another are a (C 2 -C 18 )-alkylene or (C 7 -C 15 )-aralkylene radical.
5. A biuret compound according to claim 4 wherein the radicals independently are a C 2 -C 12 )-alkylene or a (C 7 -C 12 )-aralkylene radical.
6. A biuret compound according to claim 4 wherein the radicals independently are a (C 2 -C 8 )-alkylene or a (C 7 -C 9 )-aralkylene radical.
7. A biuret compound according to claim 4 wherein the radicals independently are a hexamethylene, octamethylene or m-xylylene radical.
8. A biuret compound according to claim 1 , wherein the radical R 4 is a (C 2 -C 40 )-alkylene, (C 3 -C 40 )-alkenylene, (C 5 -C 40 )-cycloalkylene, arylene or (C 7 -C 40 )-aralkylene radical.
9. A biuret compound according to claim 8 wherein the radical is a (C 30 -C 40 )-alkylene, (C 30 -C 40 )-alkenylene, (C 30 -C 40 )-cycloalkylene, arylene or (C 30 -C 40 )-aralkylene radical.
10. A biuret compound according to claim 1 , wherein at R 6 is a (C 1 -C 30 )-alkyl or a (C 3 -C 22 )-alkenyl radical.
11. A biuret compound according to claim 1 , wherein Z is NHCO or CONH.
12. A biuret compounds according to claim 1 , wherein a is equal to 2 to 7.
13. A composition comprising a mixture of biuret compounds wherein each biuret compound of the mixture is a biuret compound according to claim 1 .
14. A process for preparing a biuret compound according to claim 1 , comprising reacting a uretdione of the general formula (A)
where R 1 is a (C 1 -C 22 )-alkylene, (C 3 -C 22 )-alkenylene, (C 5 -C 15 )-cycloalkylene, arylene, (C 7 -C 12 )-aralkylene, a polyoxyalkylene radical or is a polyester radical,
R 2 is a (C 1 -C 22 )-alkyl, hydroxy-(C 1 -C 22 )-alkyl, (C 3 -C 18 )-alkenyl, aryl, (C 7 -C 12 )-aralkyl, or (C 5 -C 12 )-cycloalkyl radical, a hydroxy-, (C 1 -C 22 )-alkoxy-, (C 5 -C 12 )-cycloalkoxy-, or (C 7 -C 12 )-aralkoxy-polyoxyalkylene radical, or a polyester prepared starting from a (C 1 -C 22 )-alkanol, (C 5 -C 12 )-cycloalkanol, or (C 7 -C 12 )-aralkanol or from a (C 1 -C 22 )-alkoxy-, (C 6 -C 12 )-cycloalkoxy-, or (C 7 -C 12 )-aralkoxy-polyoxyalkylene, and
Each Y is independently selected from the group consisting of O, NH, CO—NH—NH or NH—NH—CO,
with at least one monoamine-functional compound of the idealized general structure (B)
H 2 N—R 3 -[Z-R 4 -Z-R 5 ] a -Z-R 6 (B)
where R 3 , R 4 and R 5 independently of one another are a (C 2 -C 40 )-alkylene, (C 3 -C 40 )-alkenylene, (C 5 -C 40 )-cycloalkylene, arylene, (C 7 -C 40 )-aralkylene or polyoxyalkylene radical or are a polyester radical,
R 6 is a (C 1 -C 30 )-alkyl, (C 3 -C 22 )-alkenyl, hydroxyalkyl and hydroxyalkenyl, (C 4 -C 13 )-cycloalkyl, aryl or (C 7 -C 12 )-aralkyl radical,
Each Z is independently selected from the group consisting of COO, OCO, NHCO, CONH, NHCOO, OOCNH and NHCONH, and
a is a number from 1 to 19.
15. A rheology control agent comprising the biuret compound according to claim 1 or a mixture thereof.
16. A thixotropic coating system comprising a coating composition of at least one binder, an optional solvent and one or more biuret compounds according to claim 1 .
17. A thixotropic coating system according to claim 16 wherein the biuret compounds function as anti-sag agents and/or anti-settling agents.