Use of depolymerised carboxylated celluloses for dispersing and grinding mineral materials

Patent metadata

Field	Value
Publication number	US-9700863-B2
Application number	US-201415025920-A
Country	US
Kind code	B2
Filing date	Oct 27, 2014
Priority date	Nov 4, 2013
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

The present invention concerns the use of depolymerized carboxylated celluloses as a dispersing agent or grinding aid agent for aqueous suspensions of mineral materials, intended for paint formulations, plastic formulations, detergent formulations, cosmetic formulations, paper formulations or paper coating colors.

First claim

The invention claimed is:

1. A process, comprising grinding, dispersing, or both grinding and dispersing, mineral material in the presence of an aqueous solution of depolymerized carboxylated cellulose, wherein:
the aqueous solution of the depolymerized carboxylated cellulose has a solids content ranging from 25 wt % to 40 wt % relative to a total weight of the aqueous solution; and
the depolymerized carboxylated cellulose has a molecular weight ranging from 10,000 g/mol to 40,000 g/mol.

2. The process of claim 1 , wherein the depolymerized carboxylated cellulose is carboxymethylcellulose.

3. The process of claim 1 , wherein the depolymerized carboxylated cellulose has a polydispersity index PI ranging from 2 to 10.

4. The process of claim 1 , wherein the depolymerized carboxylated cellulose is partially or completely neutralized with one or more neutralizing agents selected from the group consisting of sodium hydroxide, calcium hydroxide, magnesium hydroxide, potassium hydroxide and an amine.

5. The process of claim 1 , wherein the solution of the depolymerized carboxylated cellulose is obtained by a method comprising:
1) depolymerisation, wherein:
1a) a reactor containing water is heated to a temperature between 50 and 85° C. (inclusive),
1b) a carboxylated cellulose to be depolymerized, having a degree of substitution between 0.2 and 2, and a peroxide are added to the reactor gradually and simultaneously, maintaining the temperature according to 1a), and
1c) after adding all of the reactants according to 1b) to form a mixture, the temperature of the mixture is maintained according to 1a) until there is complete consumption of the peroxide;

2) cooling the mixture to a temperature below 75° C.; and
3) optionally neutralizing the mixture.

6. The process of claim 1 , wherein the mineral material is selected from the group consisting of natural calcium carbonate, synthetic calcium carbonate, a dolomite, kaolin, talc, gypsum, lime, magnesia, titanium dioxide, satin white, aluminum trioxide, aluminum trihydroxide, a silica, mica and mixtures thereof.

7. The process of claim 1 , wherein the mineral material is present in said aqueous solution of the depolymerized cellulose in the form of an aqueous suspension of said mineral material during said grinding, dispersing, or both grinding and dispersing, and wherein said depolymerized cellulose is present in an amount from 0.01 to 8 wt %, based on the total weight of the solids in the suspension.

8. The process of claim 1 , wherein the mineral material is present in said aqueous solution of the depolymerized cellulose in the form of an aqueous suspension of said mineral material during said grinding, dispersing, or both grinding and dispersing, and wherein the aqueous suspension of mineral material has a granulometric distribution such that at least 60 wt % of particles have an equivalent diameter less than or equal to 2 μm.

9. The process of claim 1 , wherein the process produces an aqueous suspension that has a Brookfield viscosity below 1000 mPa·s, as measured just after grinding with a viscosimeter of the Brookfield DVIII type at 25° C. and a speed of 100 rev/min.

10. The process of claim 1 , wherein the process produces an aqueous suspension is adapted to function as a paint formulation, a plastic formulation, a detergent formulation, a cosmetic formulation, a paper formulation or a paper coating color.

11. The process of claim 1 , wherein the mineral material is calcium carbonate.

12. A composition comprising
an aqueous solution of a depolymerized carboxylated cellulose having a solids content between 25 and 40 wt % relative to a total weight of the solution, said depolymerized carboxylated cellulose having a molecular weight ranging from 10,000 g/mol to 40,000 g/mol, and
a mineral material present in said aqueous solution of the depolymerized carboxylated cellulose in the form of an aqueous suspension of said mineral material,
wherein said mineral material is selected from the group consisting of calcium carbonate, a dolomite, kaolin, talc, gypsum, lime, magnesia, titanium dioxide, satin white, aluminum trioxide, aluminum trihydroxide, a silica, mica and mixtures thereof.

13. The composition of claim 12 , wherein the mineral material is calcium carbonate.

14. The composition of claim 12 , wherein the depolymerized carboxylated cellulose is carboxymethylcellulose.

15. The composition of claim 12 , wherein the depolymerized carboxylated cellulose has a polydispersity index PI ranging from 2 to 10.

16. The composition of claim 12 , wherein the mineral material is calcium carbonate, and wherein the aqueous suspension of calcium carbonate has a granulometric distribution such that at least 60 wt % of particles have an equivalent diameter less than or equal to 2 μM.

Assignees

• Coatex Sas

Inventors

• Champagne Clementine
• Jacquemet Christian
• Mongoin Jacques
• Suau Jean-Marc

Classifications

• C09C1/3018

  Grinding · CPC title

• C09C1/402

  Satin white, modifications thereof, e.g. carbonated or silicated; Calcium sulfoaluminates; Mixtures thereof, e.g. with calcium carbonate or kaolin · CPC title

• C09C1/42

  Clays · CPC title

• C09C1/3623

  Grinding · CPC title

• C09C3/04 Primary

  Physical treatment, e.g. grinding or treatment with ultrasonic vibrations {(C09C3/006 takes precedence)} · CPC title