Drying process

Patent metadata

Field	Value
Publication number	US-11261100-B2
Application number	US-201916598093-A
Country	US
Kind code	B2
Filing date	Oct 10, 2019
Priority date	Jul 11, 2014
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

The present invention refers to a process for making a calcium carbonate containing material, wherein the process includes a specific drying procedure and allows for the provision of calcium carbonate materials with reduced moisture pick-up and low porosity.

First claim

We claim:

1. A calcium carbonate and hydrophobizing agent containing material obtainable by a process comprising the following steps:
a) providing a particulate moist calcium carbonate containing material, said material
i) having a moisture content of more than 65 wt.-%, based on the weight of the moist calcium carbonate containing material, and
ii) containing no dispersant or containing a sub-effective amount of dispersant;

b) reducing the moisture content of the moist calcium carbonate containing material of step a), thereby removing a part of the water soluble matter present in the particulate moist calcium carbonate containing material, wherein the moisture is removed with mechanical means at a temperature in the range of more than 0° C. to 65° C. in one or more steps by at least 10% and in any case to a reduced moisture content of less than 65 wt.-%, based on the weight of the moist calcium carbonate containing material;
c) thermally concentrating the moist calcium carbonate containing material with the reduced moisture content of step b) at a temperature in the range of −100° C. to 100° C. until a final moisture content of not more than 1.0 wt.-%, based on the weight of the calcium carbonate containing material; and
treating the calcium carbonate containing material obtained in step c) with a hydrophobizing agent selected from the group consisting of stearic acid, behenic acid, palmitic acid, isostearic acid, montanic acid, capric acid, lauric acid, myristic acid, and mixtures thereof,
wherein the calcium carbonate and hydrophobizing agent containing material has a moisture sorption susceptibility of less than 0.5 mg/g.

2. A calcium carbonate and hydrophobizing agent containing material obtainable by a process according to claim 1 , wherein the calcium carbonate containing material has a moisture sorption susceptibility of less than 0.3 mg/g.

3. A calcium carbonate containing particulate material, wherein the calcium carbonate containing material has a moisture sorption susceptibility of less than 0.5 mg/g after treatment with a hydrophobizing agent selected from the group consisting of stearic acid, behenic acid, palmitic acid, isostearic acid, montanic acid, capric acid, lauric acid, myristic acid, and mixtures thereof.

4. A calcium carbonate containing particulate material having a weight median particle size d 50 value in the range of 0.9 to 2.0 μm, wherein the calcium carbonate containing material has a moisture sorption susceptibility of less than 0.5 mg/g after treatment with a hydrophobizing agent selected from the group consisting of stearic acid, behenic acid, palmitic acid, isostearic acid, montanic acid, capric acid, lauric acid, myristic acid, and mixtures thereof, and wherein the calcium carbonate containing material has a total specific pore volume of less than 0.47 cm 3 /g in the pore diameter range of 0.004 to 2.4 μm before treatment with said hydrophobizing agent.

5. A calcium carbonate and hydrophobizing agent containing material according to claim 2 , wherein the calcium carbonate containing material has a total specific pore volume of less than 0.83 cm 3 /g before treatment with said hydrophobizing agent.

6. A calcium carbonate and hydrophobizing agent containing material according to claim 2 , wherein the calcium carbonate and hydrophobizing agent containing material has a total specific pore volume of less than 0.46 cm 3 /g in the pore diameter range of 0.004 to 2.4 μm before treatment with said hydrophobizing agent.

7. A calcium carbonate and hydrophobizing agent containing material according to claim 2 , wherein the calcium carbonate and hydrophobizing agent containing material has a volume defined pore size polydispersity expressed as full width at half maximum (FWHM) of 0.9 μm or above before treatment with said hydrophobizing agent.

8. A calcium carbonate and hydrophobizing agent containing material according to claim 1 , wherein the calcium carbonate and hydrophobizing agent containing material has a weight median particle size d 50 value of 1.2 to 1.9 μm.

9. A process of using a calcium carbonate and hydrophobizing agent containing material according to claim 1 as a filler, comprising adding said calcium carbonate and hydrophobizing agent containing particulate material to a composition used in polymer compositions, paper making, paper coatings, agricultural applications, paints, adhesives, sealants, construction applications and/or cosmetic applications.

10. A process of using a calcium carbonate and hydrophobizing agent containing material according to claim 2 as a filler, comprising adding said calcium carbonate and hydrophobizing agent containing particulate material to a composition used in the manufacture of a polymer product.

11. A process for producing a polymer product, wherein a calcium carbonate and hydrophobizing agent containing material according to claim 2 is added to at least one polymer.

12. The process of claim 11 wherein the at least one polymer is a thermoplastic polymer selected from the group consisting of homopolymers and/or copolymers of polyolefins, polyamides, polystyrenes, polyacrylates, polyvinyls, polyurethanes, halogen-containing polymers, polyesters, polycarbonates, and mixtures thereof.

13. A calcium carbonate containing particulate material according to claim 3 , wherein the calcium carbonate containing material has a moisture sorption susceptibility of less than 0.3 mg/g after treatment with a hydrophobizing agent.

14. A calcium carbonate containing particulate material according to claim 4 , wherein the calcium carbonate containing material has a moisture sorption susceptibility of less 0.3 mg/g after treatment with a hydrophobizing agent.

15. A calcium carbonate and hydrophobizing agent containing material according to claim 2 , wherein the calcium carbonate containing material has a total specific pore volume of less than 0.83 cm 3 /g before treatment with said hydrophobizing agent.

16. A calcium carbonate containing particulate material according to claim 3 , wherein the calcium carbonate containing material has a total specific pore volume of less than 0.83 cm 3 /g before treatment with said hydrophobizing agent.

17. A calcium carbonate containing particulate material according to claim 4 , wherein the calcium carbonate containing material has a total specific pore volume of less than 0.83 cm 3 /g before treatment with said hydrophobizing agent.

18. A calcium carbonate and hydrophobizing agent containing material according to claim 2 , wherein the calcium carbonate and hydrophobizing agent containing material has a total specific pore volume of less than 0.46 cm 3 /g in the pore diameter range of 0.004 to 2.4 μm before treatment with said hydrophobizing agent.

19. A calcium carbonate containing particulate material according to claim 3 , wherein the calcium carbonate containing material has a total specific pore volume of less than 0.46 cm 3 /g in the pore diameter range of 0.004 to 2.4 μm before treatment with said hydrophobizing agent.

20. A calcium carbonate containing particulate material according to claim 4 , wherein the calcium carbonate containing material has a total specific pore volume of less than 0.46 cm 3 /g in the pore diameter range of 0.004 to 2.4 μm before treatment with said hydrophobizing agent.

21. A calcium carbonate and hydrophobizing agent containing material according to claim 2 , wherein the calcium carbonate and hydrophobizing agent containing material has a volume defined pore size polydispersity expre

Assignees

• Omya Int Ag

Inventors

• Buri Matthias
• Ridgway Catherine Jean
• Gane Patrick A C
• Rentsch Samuel
• Burkhalter René
• Senti-Wenk Armelle
• Brunner Martin
• Morieras Gil
• Fornera Tazio

Classifications

• C09D7/61

  inorganic · CPC title

• C09C3/08

  Treatment with low-molecular-weight {non-polymer} organic compounds {(C09C3/006, C09C3/048 take precedence)} · CPC title

• D21H19/385

  Oxides, hydroxides or carbonates · CPC title

• C09C1/021 Primary

  Calcium carbonates · CPC title

• C04B2103/65

  Water proofers or repellants · CPC title