Method for preparing a composition including synthetic inorganic particles

Patent metadata

Field	Value
Publication number	US-9505625-B2
Application number	US-201113996986-A
Country	US
Kind code	B2
Filing date	Dec 22, 2011
Priority date	Dec 23, 2010
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A method for preparing a composition including synthetic mineral particles, in which: a hydrogel that is a precursor of the synthetic mineral particles is prepared, and the hydrogel is subjected to a hydrothermal treatment, characterized in that at least one step of the hydrothermal treatment is carried out with the addition of at least one carboxylate salt to the treatment medium, the carboxylate salt having the formula R—COOM′, where M′ denotes a metal selected from the group consisting of Na and K, and R is selected from H and the alkyl groups that include fewer than 10 carbon atoms.

First claim

The invention claimed is:

1. A method for preparing a composition comprising synthetic mineral particles, said method comprising:
preparing a hydrogel precursor of said synthetic mineral particles; and
subjecting said hydrogel precursor to a hydrothermal treatment,

wherein at least one step of said hydrothermal treatment is carried out with the addition of at least one carboxylate salt to the treatment medium, said carboxylate salt having the formula R—COOM′ wherein:
M′ denotes a metal selected from the group consisting of Na and K, and
R is selected from the group consisting of H and alkyl groups having fewer than 10 carbon atoms.

2. The method as claimed in claim 1 , wherein R is selected from the group consisting of H—, CH 3 — and CH 3 —CH 2 —CH 2 —.

3. The method as claimed in claim 1 , wherein said synthetic mineral particles are silicate mineral particles.

4. The method as claimed in claim 1 , wherein said synthetic mineral particles are phyllosilicate mineral particles.

5. The method as claimed in claim 1 , wherein said hydrogel precursor of said synthetic mineral particles is a gel of the formula (Si x Ge 1-x ) 4 M 3 O 11 , n′H 2 O, wherein:
M denotes at least one divalent metal having the formula Mg y(1) Co y(2) Zn y(3) Cu y(4) Mn y(5) Fe y(6) Ni y(7) Cr y(8) ; wherein each y(i) represents a real number of the interval [0; 1], such that

∑

i
=
1

8

⁢

y
⁡

(
i
)

=
1

,

wherein
x is a real number of the interval [0; 1],
n′ refers to a number of molecule(s) of water associated with said gel.

6. The method as claimed in claim 1 , wherein said at least one carboxylate salt of the formula R—COOM′ is added to said treatment medium so to provide, based on said hydrogel precursor of said synthetic mineral particles, a molar ratio R—COOM′/hydrogel of from 0.4 to 100.

7. The method as claimed in claim 3 , wherein said at least one carboxylate salt of the formula R—COOM′ is added to said treatment medium to provide, based on silicon, a molar ratio R—COOM′/Si of from 0.1 to 25.

8. The method as claimed in claim 1 , wherein said at least one carboxylate salt of the formula R—COOM′ is added to said treatment medium at the start of said hydrothermal treatment.

9. The method as claimed in claim 1 , wherein said at least one carboxylate salt of the formula R—COOM′ is added to said treatment medium so as to adjust its pH to a value of from 8 to 12.

10. The method as claimed in claim 1 , wherein said at least one carboxylate salt of the formula R—COOM′ is added to said treatment medium so that the concentration of carboxylate salt of the formula R—COOM′ in the treatment medium is from 0.2 mol/1 to 10 mol/l.

11. The method as claimed in claim 1 , wherein said hydrothermal treatment is carried out at a temperature of from 150° C. to 600° C.

12. The method as claimed in claim 1 , wherein said hydrothermal treatment is carried out under saturation vapour pressure and with stirring.

13. The method as claimed in claim 1 , wherein, following said hydrothermal treatment, said synthetic mineral particles obtained are dried by lyophilization.

14. The method as claimed in claim 1 , wherein, following said hydrothermal treatment, an anhydrous thermal treatment is carried out at a temperature of from 300° C. to 600° C.

15. The method as claimed in claim 5 , wherein said gel is prepared by a coprecipitation according to the reaction:

4
⁢

(

(

Na
2

⁢

OSiO
2

)

x

(

Na
2

⁢

OGeO
2

)

)

-
x

+

2
⁢
HCl

+

mH
2

⁢
O

+

3
⁢

(

y
1

⁡

(

MgCl
2

)

+

y

(
2
)

⁡

(

CoCl
2

)

+

y

(
3

Assignees

• Le Roux Christophe
• Martin Francois
• Micoud Pierre
• Dumas Angela
• Univ Toulouse 3 Paul Sabatier
• Centre Nat De La Rech Scient (C N R S )

Inventors

• Le Roux Christophe
• Martin Francois
• Micoud Pierre
• Dumas Angela

Classifications

• C01B33/20

  Silicates (persilicates C01B15/14 {; containing aluminium C01B33/26}) · CPC title

• C01B33/22 Primary

  Magnesium silicates · CPC title

• C01B33/38

  Layered base-exchange silicates, e.g. clays, micas or alkali metal silicates of kenyaite or magadiite type {(activation of naturally occurring clays B01J20/12; pillared layered base-exchange silicates B01J29/049)} · CPC title