Coarse pigment addition and high solids slurries for higher coating colour concentrations

Patent metadata

Field	Value
Publication number	US-9574305-B2
Application number	US-201013496960-A
Country	US
Kind code	B2
Filing date	Sep 21, 2010
Priority date	Sep 21, 2009
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

The present invention relates to an aqueous slurry comprising natural ground calcium carbonate which has a percentage P 5 by weight of particles having a diameter of less than 5.0 μm of from 98.5% to 90%, a percentage P 2 by weight of particles having a diameter of less than 2.0 μm of from 96% to 80%, wherein the ratio of P 2 /P 5 is from 0.98 to 0.85, and wherein the slurry has a solids content of more than 78 wt %.

First claim

The invention claimed is:

1. An aqueous slurry comprising a mineral material consisting of natural ground calcium carbonate which has a percentage P 5 by weight of particles having a diameter of less than 5.0 μm of from 98.5% to 90% and 1.5 to 10% by weight of particles having a diameter greater than 5.0 μm, a percentage P 2 by weight of particles having a diameter of less than 2.0 μm of from 96% to 80% and 4.0 to 20% by weight of particles having a diameter greater than 2.0 μm, wherein the ratio of P 2 /P 5 is from 0.98 to 0.85, wherein the slurry has a solids content of more than 78 wt %, and wherein the natural ground calcium carbonate is the only inorganic material which is present in the aqueous slurry.

2. The slurry according to claim 1 , wherein the natural ground calcium carbonate is obtained from marble, limestone, chalk, or any mixture thereof.

3. The slurry according to claim 1 , wherein the natural ground calcium carbonate has a percentage P 1 by weight of particles having a diameter of less than 1.0 μm of from 88% to 60%.

4. The slurry according to claim 3 , wherein the ratio of P 1 /P 5 is from 0.75 to 0.65.

5. The slurry according to claim 1 , wherein the natural ground calcium carbonate has a percentage P 1 by weight of particles having a diameter of less than 1.0 μm of from 88% to 60%, and the ratio of P 1 /P 5 is from 0.75 to 0.65.

6. The slurry according to claim 1 , wherein the slurry does not contain latex particles.

7. The slurry according to claim 1 , wherein the natural ground calcium carbonate contains a first fraction having a percentage P 5 (F1) by weight of particles having a diameter of less than 5.0 μm of from 75% to 85% and a median particle diameter d 50 of from 2.0 to 3.0 μm, and a second fraction having a percentage P 2 (F2) by weight of particles having a diameter of less than 2.0 μm of from 85% to 100% and a median particle diameter d 50 of from 0.3 to 0.65 μm.

8. The slurry according to claim 7 , wherein the ratio of the median particle diameter d 50 of the first fraction to the median particle diameter d 50 of the second fraction is at least 3.5.

9. The slurry according to claim 7 , wherein the weight ratio of the first fraction to the second fraction is from 5/95 to 20/80.

10. The slurry according to claim 1 , wherein the percentage P 5 by weight of particles having a diameter of less than 5.0 μm is from 98% to 93% and 2 to 7% by weight of particles having a diameter greater than 5.0 μm.

11. The slurry according to claim 1 , wherein the percentage P 5 by weight of particles having a diameter of less than 5.0 μm is from 98% to 90% and 2 to 10% by weight of particles having a diameter greater than 5.0 μm.

Assignees

• Bluvol Guillermo
• Kässberger Michael
• Gane Patrick A C
• Omya Int Ag

Inventors

• Bluvol Guillermo
• Kässberger Michael
• Gane Patrick A C

Classifications

• C01P2006/12

  Surface area · CPC title

• D21H19/40

  siliceous, e.g. clays · CPC title

• D21H17/67 Primary

  Water-insoluble compounds, e.g. fillers, pigments · CPC title

• C04B14/285

  Marble · CPC title

• D21H19/38

  characterised by the pigments · CPC title