Water-insoluble metal hydrate containing an alkali metal and preparation methods thereof

Patent metadata

Field	Value
Publication number	US-10144868-B2
Application number	US-201414551602-A
Country	US
Kind code	B2
Filing date	Nov 24, 2014
Priority date	Sep 26, 2014
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

The present invention relates to a novel method for preparing a water-insoluble metal hydroxide, and a use thereof. The water-insoluble metal hydroxide of the present invention is conveniently and efficiently prepared s through the high-temperature heat treatment step two times and the washing step, and thus contains a small amount of an alkali metal and has a high crystallinity and a phase purity. The water-insoluble metal hydroxide of the present invention or metal oxide therefrom exhibits an absorption wavelength at a low wavelength range (for example, 490 nm or less) and a light emitting wavelength at a high wavelength range (for example, from 500 nm or more to less than 1,100 nm). Accordingly, the water-insoluble metal hydroxide of the present invention may be efficiently used in various applications such as a fire retardant, an antacid, an adsorbent and so forth, and may also be doped with another metal ion to be utilized as a raw material for fabricating a catalyst, a fluorescent material, an electrode material, a secondary battery material and the like.

First claim

What is claimed is:

1. A method for preparing a water-insoluble metal hydroxide, comprising the steps of:
(a) combusting a mixed aqueous solution of a metal salt, an alkali salt and an urea at a temperature of from more than 400° C. to less than 700° C.;
(b) subjecting a powder obtained in step (a) to heat treatment at a temperature of 700° C. to 1,300° C.; and
(c) washing a powder obtained in step (b) with an aqueous solution,
wherein the metal salt is one or more metal salts selected from the group consisting of a lanthanide metal, a transition metal and a post-transition metal, and
the water-insoluble metal hydroxide is represented by the following Formula 2:
(M 1-y M′ y )O x/2 (OH) 3-x :N w   Formula 2

in the Formula 2, M and M′ are each one or more metals selected from the group consisting of a lanthanide metal, a transition metal and a post-transition metal; N is an alkali or alkaline earth metal; and y is a real number of 0<y ≤0.50, x is a real number of 0≤x ≤2.9 and w is a real number of 0.001≤w≤0.5.

2. The method of claim 1 , wherein the lanthanide metal is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu.

3. The method of claim 1 , wherein the transition metal is Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ru, Rh, Ag, Cd, lr, W, Au or Hg.

4. The method of claim 1 , wherein the post-transition metal is Al, Ga, In, Sn, Tl, Pb or Bi.

5. The method of claim 1 , wherein the alkali salt is an alkali metal or alkaline earth metal salt.

6. The method of claim 5 , wherein the alkali metal or alkaline earth metal salt is a salt compound comprising Li, Na, K, RID, Cs, Fr, Be, Mg, Ca, Sr, Ba or Ra.

7. The method of claim 1 , wherein the alkali salt comprises an amount of at least one equivalent or larger than an amount of the metal salt.

8. The method of claim 1 , wherein an amount of the alkali salt remaining in the metal hydroxide is in a range of 0.001 to 50 atm % compared with that of the metal salt.

9. The method of claim 1 , wherein a heat treatment time in step (b) is carried out for 1 to 4 hours.

10. The method of claim 1 , wherein the method further comprises a step of removing the aqueous solution.

11. The method of claim 1 , wherein the water-insoluble metal hydroxide exhibits a fluorescent or light emitting property.

12. The method of claim 1 , wherein the water-insoluble metal hydroxide exhibits an absorption wavelength of 490 nm or less and a light emitting wavelength in a range of 500 nm to 1,100 nm.

13. The method of claim 1 , wherein the water-insoluble metal hydroxide is represented by the following Formula 3 when the water-insoluble metal hydroxide comprises three or more metals:
(M 1-z-r M a z M b r )O x/2 (OH) 3-x ;N w   Formula 3

in the Formula 3, M, M a and M b are each one or more metals selected from the group consisting of a lanthanide metal, a transition metal and a post-transition metal; N is an alkali or alkaline earth metal; and each z and r is a real number of 0 <z <0.50 and 0<r<0.50, x is a real number of 0≤x≤2.9, and w is a real n mber of 0.001≤w0.5.

14. The method of claim 1 , wherein the method further comprises a step of heating the water-insoluble metal hydroxide in a temperature range of 300′C to 1,400° C. to obtain a water-insoluble metal oxide.

15. A light emitting device comprising the fluorescent water-insoluble metal hydroxide prepared according to the method of claim 1 , and a excitation light source of 490 nm or less.

16. The light emitting device of claim 14 , wherein the light ernitting device is a white light emitting diode (LED).

Assignees

• Korea Inst Sci & Tech

Inventors

• Cho So Hye
• Lee Seung Yong
• Sovann Khan
• Park Jong Ku
• Kim Sun Jin
• Jang Ho Seong

Classifications

• Y02E10/52

  PV systems with concentrators · CPC title

• C09K11/77

  containing rare earth metals · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C09K11/60

  containing iron, cobalt or nickel · CPC title

• C01P2002/72

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