COMPOSITION COMPRISING INORGANIC PARTICULATE MATERIAL AND AN POLYMERIC DISPERSANT
An anionic polymeric dispersant and a composition comprising inorganic particulate material and an anionic polymeric dispersant. A method of grinding a composition comprising inorganic particulate material and an anionic polymeric dispersant and a use of anionic polymeric dispersant to maintain the viscosity of a composition comprising inorganic particulate material.
1 . A composition comprising inorganic particulate material and an anionic polymeric dispersant, wherein:
less than about 40% of the anions present on the polymeric dispersant are neutralized by magnesium ions;
about 60% or less of the anions present on the polymeric dispersant are neutralized by sodium ions; and
about 70% or less of the anions present on the polymeric dispersant are not neutralized by sodium or magnesium ions.
2 . The composition of claim 1 , wherein from about 1% to about 39% of the anions present on the polymeric dispersant are neutralized by magnesium ions.
3 . The composition of claim 1 , wherein from about 1% to about 60% of the anions present on the polymeric dispersant are neutralized by sodium ions.
4 . The composition of claim 1 , wherein from about 1% to about 70% of the anions present on the polymeric dispersant are not neutralized by sodium or magnesium ions.
5 . The composition of claim 1 , wherein the inorganic particulate material comprises calcium carbonate.
6 . The composition of claim 5 , wherein substantially all of the anions present on the polymeric dispersant that are not neutralized by sodium or magnesium ions are neutralized by calcium ions.
7 . The composition of claim 1 , wherein the anionic polymeric dispersant comprises polyacrylic acid.
8 . The composition of claim 1 , wherein the composition has a viscosity ranging from about 100 mPa·s to about 2000 mPa·s immediately after preparation.
9 . The composition of claim 1 , wherein the composition has a viscosity ranging from about 100 mPa·s to about 500 mPa·s up to 7 days after preparation.
10 . The composition of claim 1 , wherein the composition is an anionic polymeric dispersant.
11 . A method of grinding a composition comprising, providing a composition comprising an inorganic particulate material and an anionic polymeric dispersant as defined in claim 1 , and grinding the composition.
12 . A method of maintaining the viscosity of a composition comprising: providing a composition comprising an inorganic particulate material and an anionic polymeric dispersant as defined in claim 1 , and controlling the amount of the anionic polymeric dispersant to maintain the viscosity of the composition within the range of about 100 mPa·s to about 2000 mPa·s.
13 . A composition comprising inorganic particulate material and an anionic polymeric dispersant, wherein the composition has a viscosity ranging from about 100 mPa·s to about 2000 mPa·s up to 7 days after preparation.
14 . The composition of claim 13 , wherein the composition has a viscosity ranging from about 100 mPa·s to about 1000 mPa·s up to 7 days after preparation.
15 . The composition of claim 1 , wherein the composition has a solids content equal to or greater than about 60% by weight of the composition.
16 . The composition of claim 13 , wherein:
less than about 40% of the anions present on the polymeric dispersant are neutralized by magnesium ions;
about 60% or less of the anions present on the polymeric dispersant are neutralized by sodium ions; and
about 70% or less of the anions present on the polymeric dispersant are not neutralized by sodium or magnesium ions.
17 . The composition of claim 13 , wherein from about 1% to about 39% of the anions present on the polymeric dispersant are neutralized by magnesium ions.
18 . The composition of claim 13 , wherein from about 1% to about 60% of the anions present on the polymeric dispersant are neutralized by sodium ions.
19 . The composition of claim 13 , wherein the inorganic particulate material comprises calcium carbonate.
20 . The composition of claim 13 , wherein the anionic polymeric dispersant comprises polyacrylic acid.