Claims
- 1. A bimodal aqueous coating composition containing in dispersed form as binder an isocyanate-reactive component and a polyisocyanate component, in which these components have a particle size distribution having a first distribution maximum at a particle size of 40 to 200 nm and a second distribution maximum at a particle size of 200 to 2,000 nm, provided that the particle sizes of the distribution maxima differ by a factor of at least 2.
- 2. The coating composition of claim 1, wherein 99% by weight of the dispersed components have a particle size of less than 5000 nm.
- 3. A process for the preparation of an aqueous coating composition containing an isocyanate-reactive component and a polyisocyanate component by mixing the components with water and forcing the mixture at a pressure of 1 to 30 MPa through one or more nozzles having an opening of about 0.2 to 1 mm in at least one dimension.
- 4. The process of claim 3 wherein the nozzle size in the direction of flow is one to three times the size of said opening.
- 5. The process of claim 3 wherein the pressure is 1 to 8 MPa.
- 6. The process of claim 3 wherein the pressure is 2 to 6 MPa.
- 7. The process of claim 3 which comprises forcing the mixture at a pressure of 1 to 30 MPa through up to three nozzles in succession, each nozzle having an opening of about 0.2 to 1 mm in at least one dimension.
- 8. The process of claim 7 wherein the nozzle size in the direction of flow is one to three times the size of said opening.
- 9. The process of claim 7 wherein the pressure is 1 to 8 MPa.
- 10. The process of claim 7 wherein the pressure is 2 to 6 MPa.
- 11. The process of claim 3 which comprises forcing the mixture at a pressure of 1 to 30 MPa through two nozzles arranged such that their openings are arranged opposite to each other, each nozzle having an opening of about 0.2 to 1 mm in at least one dimension.
- 12. The process of claim 11 wherein the nozzle size in the direction of flow is one to three times the size of said opening.
- 13. The process of claim 11 wherein the pressure is 1 to 8 MPa.
- 14. The process of claim 11 wherein the pressure is 2 to 6 MPa.
Priority Claims (2)
Number |
Date |
Country |
Kind |
44 19 570.2 |
Jun 1994 |
DEX |
|
195 10 651.2 |
Mar 1995 |
DEX |
|
Parent Case Info
This application is a continuation of application Ser. No. 08/448,870 filed May 24, 1995 now abandoned.
US Referenced Citations (12)
Foreign Referenced Citations (4)
Number |
Date |
Country |
2047635 |
Jan 1992 |
CAX |
2092117 |
Sep 1993 |
CAX |
2101876 |
Feb 1994 |
CAX |
1428907 |
Mar 1976 |
GBX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
448870 |
May 1995 |
|