Modification of layered double hydroxides

Patent metadata

Field	Value
Publication number	US-2018354809-A1
Application number	US-201816054324-A
Country	US
Kind code	A1
Filing date	Aug 3, 2018
Priority date	Sep 28, 2012
Publication date	Dec 13, 2018
Grant date	—

Abstract

The present invention relates to a process for modifying a layered double hydroxide (LDH), the process comprising,
a. providing a water-wet layered double hydroxide of formula:

[M z+ 1-x M′ y+ x ] a+ (X n− ) a/r .bH 2 O   ( 1 )
wherein M and M′ are metal cations, z=1 or 2; y=3 or 4, x is 0.1 to 1, preferably x<1, more preferably x=0.1-0.9, b is greater than 0 to 10, X is an anion, r is 1 to 3, n is the charge on the anion X and a is determined by x, y and z, preferably a=z(1-x)+xy-2; b. maintaining the layered double hydroxide water-wet, and c. contacting the water-wet layered double hydroxide with at least one solvent, the solvent being miscible with water and preferably having a solvent polarity (P′) in the range 3.8 to 9,

as well as to a layered double hydroxide prepared according to that process.

First claim

What is claimed is:

1 . A layered double hydroxide, prepared according to a process comprising:
a. providing a layered double hydroxide that is water wet and of formula:
[M z+ 1-x M′ y+ x (OH) 2 ] a+(X − ) a/r .bH 2 O

wherein M and M′ are metal cations, z=1 or 2; y=3 or 4, x is 0.1 to 1, b is greater than 0 to 10, X is an anion, r is 1 to 3, n is the charge on the anion X, and a=z(1-x)+xy-2;
b. maintaining the layered double hydroxide water-wet, and c. dispersing the layered double hydroxide that is water-wet in at least one solvent, the at least one solvent being miscible with water.

2 . The layered double hydroxide of claim 1 , wherein the process includes filtering and washing the layered double hydroxide with the at least one solvent or a second solvent that is miscible with water, after dispersing the layered double hydroxide that is water-wet in the at least one solvent.

3 . The layered double hydroxide of claim 2 , wherein the process includes subjecting the layered double hydroxide to a thermal treatment after filtering and washing the layered double hydroxide with the at least one solvent or the second solvent.

4 . The layered double hydroxide of claim 2 , wherein the process includes drying the layered double hydroxide after filtering and washing the layered double hydroxide with the at least one solvent or the second solvent.

5 . The layered double hydroxide of claim 2 , wherein each of the at least one solvent and the second solvent includes an organic solvent selected from the group consisting of acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, dioxane, ethanol, methanol, n-propanol, 2-propanol, tetrahydrofuran, and a mixture of two or more thereof.

6 . The layered double hydroxide of claim 1 , wherein the process includes calcining the layered double hydroxide dispersing the layered double hydroxide in the at least one solvent.

7 . The layered double hydroxide of claim 1 , wherein M is Mg, Zn, Fe, Ca or a mixture of two or more thereof.

8 . The layered double hydroxide of claim 1 , wherein M′ is Al, Ga, Fe or a mixture of Al and Fe.

9 . The layered double hydroxide of claim 1 , wherein z is 2 and M is Ca, Mg, or Zn.

10 . The layered double hydroxide of claim 1 , wherein M is Zn, Mg or Ca, and M′ is Al.

11 . The layered double hydroxide of claim 1 , wherein X is selected from the group consisting of a halide, inorganic oxyanions, anionic surfactants, anionic chromophores, anionic UV absorbers, and a combination of anionic UV absorbers an any of the foregoing.

12 . The layered double hydroxide of claim 1 , wherein the at least one solvent is an organic solvent selected from the group consisting of acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, dioxane, ethanol, methanol, n-propanol, 2-propanol, tetrahydrofuran, and a mixture of two or more thereof.

13 . A composition, comprising:
a layered double hydroxide of the formula:
[M z+ 1-x M′ y+ x (OH) 2 ] a+ (X − ) a/r .bH 2 O.c(Y)

wherein M and M′ are metal cations, z=1 or 2; y=3 or 4, x is 0.1 to 1, b is 0 to 10, X is an anion, r is 1 to 3, n is the charge on the anion X, a=z(1-x)+xy-2, c is greater than 0 to 10, and Y is an aqueous miscible organic solvent; and wherein the layered double hydroxide exhibits one or more of:
a specific surface area greater than 150 m 2 /g;
a BET pore volume (N 2 ) of at least 1 cm 3 /g;
a loose bulk density of less than 0.28 g/mL;
a tap density of less than 0.35 g/mL;
a first minima of a derivative of weight loss as a function of temperature in a thermogravimetric analysis that is 150° C. to 191° C.; or
a second minima of a derivative of weight loss as a function of temperature in a thermogravimetric analysis that is 340° C. to 392° C.

14 . The composition of claim 13 , wherein the layered double hydroxide exhibits one or more of a specific surface area (N 2 ) of greater than 155 m 2 /g, a de-aggregation factor greater than 2, or an apparent density of 0.8 g/cm 3 or lower.

15 . The composition of claim 13 , wherein the loose bulk density is 0.1 g/mL to 0.18 g/mL.

16 . The composition of claim 13 , wherein the specific surface area is 155 m 2 /g to 301 m 2 /g.

17 . The composition of claim 13 , wherein the BET pore volume 1 cm 3 /g to 3 cm 3 /g.

18 . The composition of claim 13 , wherein the tap density is 0.1 g/mL to 0.35 g/mL.

19 . The composition of claim 13 , wherein the first minima is less than 165° C. and the second minima is less than 390° C.

20 . A composition, comprising:
a layered double hydroxide of the formula:
[M z+ 1-x M′ y+ x (OH) 2 ] a+ (X n− ) a/r .bH 2 O.c(Y)

wherein M and M′ are metal cations, z=1 or 2; y=3 or 4, x is 0.1 to 1, b is greater than 0 to 10, X is an anion, r is 1 to 3, n is the charge on the anion X, a=z(1-x)+xy-2, c is 0-10, and Y is an aqueous miscible organic solvent; and wherein the layered double hydroxide exhibits:
a specific surface area greater than 150 m 2 /g;
a BET pore volume (N 2 ) of at least 1 cm 3 /g;
a loose bulk density of less than 0.28 g/mL; and
a tap density of less than 0.35 g/mL.

Assignees

• Scg Chemicals Co Ltd

Inventors

• O'Hare Dermot
• Wang Qiang

Classifications

• C01F7/784

  Layered double hydroxide, e.g. comprising nitrate, sulfate or carbonate ions as intercalating anions · CPC title

• C01G49/009 Primary

  Compounds containing iron, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01F7/785

  Hydrotalcite · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C01P2002/22

  layered hydroxide-type, e.g. of the hydrotalcite-type · CPC title