Continuous Process for Dispersing Solid Material in a Liquid

Abstract

A continuous process for dispersing a particulate solid material in a liquid comprising the steps of a) dosing a particulate solid material feed stream via a particulate solid feed line (1) into a mixing chamber (2), b) simultaneously dosing a liquid feed stream via a liquid feed line (3) into the mixing chamber (2), wherein at least one of the feed streams additionally comprises an organic film-forming binder, c) simultaneously exerting a shear force on the content of the mixing chamber (2) sufficient to mix the particulate solid material and the liquid to form a mixture of particulate solid in the liquid, and d) simultaneously exerting a shear force to the mixture of particulate solid in the liquid sufficient to reduce the particle size of the particulate solid material in a dispersing chamber (4) to form a particulate solid material dispersed in the liquid, and e) simultaneously removing a liquid product stream of particulate solid material dispersed in the liquid from the dispersing chamber via a liquid dispersion outlet line (5), wherein the mixing chamber (2) and the dispersing chamber (4) are one single chamber (2, 4), wherein the particulate solid material is in the form of powder, granules or pellets.

Claims

1. A continuous paint production process for dispersing a particulate solid material in a liquid comprising a) dosing a particulate solid material feed stream via a particulate solid feed line into a mixing chamber, b) simultaneously dosing a liquid feed stream via a liquid feed line into the mixing chamber, wherein at least one of the feed streams additionally comprises an organic film-forming binder, c) simultaneously exerting a shear force on the content of the mixing chamber sufficient to mix the particulate solid material and the liquid to form a mixture of particulate solid in the liquid, and d) simultaneously exerting a shear force to the mixture of particulate solid in the liquid sufficient to reduce the particle size of the particulate solid material in a dispersing chamber to form a particulate solid material dispersed in the liquid, and e) simultaneously removing a liquid product stream of particulate solid material dispersed in the liquid from the dispersing chamber via a liquid dispersion outlet line, wherein the mixing chamber and the dispersing chamber are one single chamber (2,4), wherein the particulate solid material is in the form of powder, granules or pellets, wherein an at least second liquid feed stream is dosed to the liquid dispersion outlet line.

2. The process according to claim 1, wherein the mixing and dispersing are carried out in a rotor-stator device.

3. The process according to claim 1, wherein the liquid feed stream comprises an organic film-forming binder.

4. The process according to claim 1, wherein the particulate solid material feed stream comprises an organic film-forming binder.

5. The process according to claim 1, wherein the particulate solid material comprises a material selected from pigments, fillers, extenders, and mixtures thereof.

6. The process according to claim 1, wherein the particulate solid material is a mixture of at least two different materials.

7. The process according to claim 1, wherein the liquid is a mixture of at least two different materials.

8. The process according to claim 1, wherein in a) at least two different particulate solid materials are dosed via at least two particulate solid feed lines into the mixing chamber.

9. The process according to claim 1, wherein in b) at least two different liquid feed streams are dosed via at least two liquid feed lines into the mixing chamber.

10. The process according to claim 1, wherein in step d) an at least second liquid feed stream is dosed to the dispersing chamber via an at least second liquid feed line.

11. The process according to claim 1, wherein the liquid is an aqueous liquid.

12. The process according to claim 1, wherein the liquid is a non-aqueous liquid.

13. The process according to claim 1, wherein the liquid product stream is a paint or paint precursor.

Description

[0049] FIG. 1 illustrates an embodiment of the process. In this embodiment, a liquid tank (13) contains a liquid comprising an organic film forming binder. The liquid tank (13) is connected to the mixing and dispersing chamber (2,4) via a liquid feed line (3). The liquid feed stream is pumped via dosing pump (12) through the liquid feed line (3). The liquid feed line further comprises a flow meter (14) to monitor the amount of liquid feed stream dosed to the mixing and dispersing chamber (2,4). A powder dosing unit (6) is connected to the mixing and dispersing chamber (2,4) via the particulate solid feed line (1) for dosing the particulate solid material. In the mixing and dispersing chamber (2,4) a shear force is exerted on the content of the chamber to mix the particulate solid material and the liquid, and to reduce the particle size of the particulate solid material. The liquid product stream of particulate solid material dispersed in the liquid is removed from the mixing and dispersing chamber (2,4) via the liquid dispersion outlet line (5) and collected in a product container (7).

[0050] FIG. 2 illustrates another embodiment of the process. In addition to the components present in FIG. 1, this embodiment further comprises a second liquid tank (11) containing a second liquid. A liquid stream from the second liquid tank (11) is pumped via dosing pump (10) through the second liquid feed line (15). The liquid feed line further comprises a flow meter (9). The second liquid feed line (15) is connected with the dispersion outlet line (5), and the contents of the both are mixed in mixing pump (8). The resulting product is collected in a product container (7). The second liquid feed line allows to adjust the solids content of the dispersion leaving the mixing and dispersing chamber (2,4).