NOVEL RHEOLOGY REGULATORS SUCH AS GROUND NATURAL CALCIUM CARBONATES OPTIONALLY TREATED WITH A FATTY ACID OR SALT AND THEIR USE
The invention relates to the selection of a natural calcium carbonate crushed to a high degree of fineness, possibly treated with one or more fatty acids or one or more of their salts or mixtures thereof, and its use as a rheology regulator for polymeric compositions. The specific surface area is 14 to 30 m 2 /g measured according to the BET method to ISO 4652, and the oil absorption is greater than 16 measured according to ISO 787-V (Rub-out method). The conditions of mixing of the constituents and manufacture are improved, as well as the properties of the final product.
1 . A method of regulating the viscosity as a function of speed of flow during the application of a plastisol to a substrate, comprising adding natural calcium carbonate, crushed to a high degree of fineness, with a specific surface area of around 14 to 30 m 2 /g measured according to the BET method to ISO 4652, to a plastisol, and adjusting the amount of added natural calcium carbonate in order to achieve a desired relationship between speed of flow and viscosity of the plastisol.
2 . The method of claim 1 , wherein the calcium carbonate has a specific surface area of around 16 to 24 m 2 /g.
3 . The method of claim 1 , wherein the calcium carbonate has a specific surface area of around 20 m 2 /g.
4 . The method of claim 1 , wherein the natural calcium carbonate has a specific surface area of at least 14.4 m 2 /g and up to around 30 m 2 /g.
5 . The method of claim 1 , wherein the natural calcium carbonate has a specific surface area of at least 16 m 2 /g and up to around 30 m 2 /g.
6 . The method of claim 1 , wherein the natural calcium carbonate has a specific surface area of at least 16.5 m 2 /g and up to around 30 m 2 /g.
7 . The method of claim 1 , wherein the natural calcium carbonate has a specific surface area of no higher than 22 m 2 /g and at least around 14 m 2 /g.
8 . The method of claim 1 , wherein the natural calcium carbonate has a specific surface area of no higher than 28 m 2 /g and at least around 14 m 2 /g.
9 . The method of claim 1 , wherein the natural calcium carbonate is treated with at least one fatty acid containing 10 to 24 carbon atoms or a salt thereof selected from the group consisting of calcium salt, magnesium salt, zinc salt, and mixtures thereof.
10 . The method of claim 1 , wherein the natural calcium carbonate is treated with stearic acid or a calcium salt thereof in a proportion of around 0.01% to 5% by weight.
11 . The method of claim 1 , wherein the natural calcium carbonate is treated with stearic acid or a calcium salt thereof in a proportion of around 1% to 4% by weight.
12 . The method of claim 1 , wherein the natural calcium carbonate has an oil absorption which is greater than 16 g/100 g measured according to ISO 787-V (Rub-out method).
13 . The method of claim 1 , wherein the plastisol is PVC-based.
14 . A method of regulating the rheology during the application of a plastisol to a substrate, comprising adding natural calcium carbonate, crushed to a high degree of fineness, with a specific surface area of around 14 to 19.5 m 2 /g measured according to the BET method to ISO 4652, to a plastisol, in an amount to regulate the rheology of the plastisol.
15 . The method of claim 14 , wherein the natural calcium carbonate has a specific surface area no higher than 16.5 m 2 /g and at least around 14 m 2 /g.
16 . The method of claim 14 , wherein the natural calcium carbonate has an oil absorption which is greater than 16 g/100 g measured according to ISO 787-V (Rub-out method).
17 . The method of claim 14 , wherein the plastisol is PVC-based.