Mineral composition, especially for use in paper fillers and paper or plastic coatings

Patent metadata

Field	Value
Publication number	US-9650258-B2
Application number	US-201514829944-A
Country	US
Kind code	B2
Filing date	Aug 19, 2015
Priority date	Dec 16, 2010
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A mineral composition comprising mineral particles, said mineral particles, when in a densely compacted bed form, having a volume defined median pore diameter from 0.01 to 0.04 micrometre, and having an intruded total specific void volume of 0.1-0.3 cm 3 /g. A specific advantage of this composition is that it as a component in a coating, allows the passage of ink solvent into the base paper while retaining the ink molecules on the surface.

First claim

The invention claimed is:

1. A method for producing a mineral particle fine fraction from a feed material comprising calcium carbonate, the method comprising:
(i) milling the feed material in a milling machine to obtain a first milled feed material;
(ii) subjecting the first milled feed material to a disc stack centrifuge to obtain a mineral particle fine fraction and a mineral particle coarse fraction; and
(iii) either feeding a part or all of the mineral particle coarse fraction to a milling machine and/or to a disc stack centrifuge and/or taking off a part or all of the mineral particle coarse fraction, to obtain a mineral particle fine fraction comprising mineral particles comprising calcium carbonate, said mineral particles, when in a densely compacted bed form, have a volume defined median pore diameter from 0.01 to 0.04 micrometre, an intruded total specific void volume of 0.1 to 0.3 cm 3 /g, a monomodal pore diameter distribution, and a volume defined pore size polydispersity expressed as full width at half maximum (FWHM) in the range of 0.01 to 0.03 micrometre.

2. The method according to claim 1 , wherein said mineral particles, when in a densely compacted bed form, have a volume defined median pore diameter from 0.01 to 0.039 micrometre, and an intruded total specific void volume of 0.10 to 0.28 cm 3 /g.

3. The method according to claim 1 , wherein said mineral particles, when in a densely compacted bed form, have a volume defined median pore diameter from 0.015 to 0.035 micrometre, and an intruded total specific void volume of 0.15 to 0.27 cm 3 /g.

4. The method according to claim 1 , wherein said mineral particles, when in a densely compacted bed form, have a volume defined median pore diameter from 0.017 to 0.033 micrometre, and an intruded total specific void volume of 0.20 to 0.25 cm 3 /g.

5. The method according to claim 1 , wherein said mineral particles, when in a densely compacted bed form, have a volume defined median pore diameter from 0.019 to 0.030 micrometre, and an intruded total specific void volume of 0.21 to 0.24 cm 3 /g.

6. The method according to claim 1 , wherein said mineral particles, when in a densely compacted bed form, have a volume defined pore size polydispersity expressed as FWMH in the range of 0.01 to 0.028 micrometre.

7. The method according to claim 1 , wherein said mineral particles, when in a densely compacted bed form, have a volume defined pore size polydispersity expressed as FWMH in the range of 0.015 to 0.021 micrometre.

8. The method according to claim 1 , wherein said mineral particles, when in a densely compacted bed form, have a volume defined pore size polydispersity expressed as FWMH in the range of 0.016 to 0.019 micrometre.

9. The method according to claim 1 , wherein the mineral particles comprise natural calcium carbonate, precipitated calcium carbonate, or a mixture thereof.

10. The method according to claim 1 , wherein the mineral particles comprise natural calcium carbonate.

11. The method according to claim 1 , wherein the first milled feed material has a solids contents in the range of 20%-80% by weight.

12. The method according to claim 1 , wherein the first milled feed material has a solids contents in the range of 30%-75% by weight.

13. The method according to claim 1 , wherein the first milled feed material has a solids contents in the range of 38%-70% by weight.

14. The method according to claim 1 , wherein in step (iii) the mineral particle coarse fraction is subjected to milling in one or more dry grinding and/or wet grinding machines to obtain the mineral particle fine fraction in one or more grinding steps.

15. The method according to claim 1 , which is performed in a continuous manner.

Assignees

• Gane Patrick Arthur Charles
• Bergset Olav
• Saunders George
• Qiu Xueping
• Varney Dan
• Omya Int Ag

Inventors

• Gane Patrick Arthur Charles
• Bergset Olav
• Saunders George
• Qiu Xueping
• Varney Dan

Classifications

• C01F11/185 Primary

  After-treatment, e.g. grinding, purification, conversion of crystal morphology · CPC title

• D21H17/67

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

• C09C1/021 Primary

  Calcium carbonates · CPC title

• D21H21/52

  Additives of definite length or shape · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title