JPWO2020165419A5

JPWO2020165419A5 -

Info

Publication number: JPWO2020165419A5
Application number: JP2021547337A
Authority: JP
Publication date: 2023-02-03

Claims

A method for manufacturing a titanium compound structure selected from the group consisting of sheet, wire and tube, comprising:
Before performing the successive steps c), d) and e),
i) successive step a) and step b), or ii) step ab)
each step comprising performing any of
a) providing at least one titanic acid having the general formula [TiO _x (OH) _4-2x ] _n and reacting it with at least one compound selected from the group consisting of TiOCl ₂ , TiCl ₄ and HCl dissolving so as to obtain a clear solution in an aqueous solution comprising
b) raising the temperature of said clear solution until it reaches a temperature in the range of 68-85° C. at which precipitation begins to occur, adding at least one acid stabilizer before said precipitation begins, and adding at least one holding the temperature for a minute to obtain a dispersion of particles containing TiO ₂ as an intermediate product;
ab) providing a dispersion of particles comprising TiO ₂ , wherein the average diameter of said particles in said dispersion is between 3 and 20 nm, preferably between 4 and 15 nm, more preferably between 4.5 and 7 nm. , said dispersion comprises at least one α-hydroxy acid as an acid stabilizer;
c) adjusting the concentration of hydroxide ions in said dispersion from step b) to at least 8M by adding an alkali metal hydroxide MOH;
d) treating said dispersion from step c) at a temperature in the range of 90-170° C. for 6-72 hours to obtain a plurality of first structures comprising an alkali metal titanate; and e) said alkali metal treating a plurality of first structures comprising titanates to exchange at least a portion of the alkali metal ions M ⁺ with H ⁺ to obtain a plurality of second structures comprising protonated titanates. Method.

After step b) or step ab) and before step c),
b1) preferably reducing the content of ions in said dispersion such that the ion concentration is reduced to the point that a sol is formed, wherein the average diameter of said particles in said sol is between 3 and 20 nm, preferably 4-15 nm, more preferably 4.5-7 nm;
b2) the concentration of TiO ₂ in said dispersion preferably to a value in the range 10-80%, more preferably to a value in the range 20-70%, most preferably in the range 30-50% 2. The method of claim 1, further comprising adjusting to a value within .

The dispersion after step b ) or the sol after steps b1) and b2) contains at least 15 wt.% titanium dioxide, preferably at least 17 wt.% titanium dioxide, more preferably at least 25 wt.% titanium dioxide. 3. A method according to claim 1 or claim 2, comprising titanium, even more preferably at least 30 wt% titanium dioxide, even more preferably at least 40 wt% titanium dioxide, most preferably at least 50 wt% titanium dioxide.

a plurality of second structures comprising said protonated titanate obtained after step e) at a temperature of 300-700°C, preferably 300-600°C, more preferably 300-450°C, most preferably 300-400°C; 4. A method according to any one of claims 1 to 3, heated to a range of temperatures to obtain a plurality of third structures comprising titanium dioxide.

A method according to any one of claims 1 to 4, wherein said at least one acid stabilizer is selected from carboxylic acids and α-hydroxy acids.

6. A process according to any one of claims 1 to 5, wherein at least one alkanolamine and at least one acid stabilizer are added together prior to step c).

7. A method according to any one of the preceding claims, wherein the dispersion remains dispersed without drying and subsequent redispersion between steps b) and c).

8. A method according to any one of the preceding claims, wherein the dispersion is dried and redispersed between steps b) and c).

9. Any one of claims 1 to 6 and 8 , wherein the particles dried from the dispersion obtained after step b) have a specific surface area measured according to ISO 9277 in the range of 200 to 300 m ² /g. or the method according to item 1.

10. A method according to any one of claims 1 to 9 , wherein the pH after dissolution in step a) is below zero.

The pH of the dispersion obtained from step b) or the sol obtained from steps b1) and b2) is adjusted to a value in the range of 0.5 to 1.5 . A method according to any one of paragraphs.

12. A method according to any one of the preceding claims, wherein the plurality of first structures comprising alkali metal titanate is separated from the remaining liquid between steps d) and e).

13. A method according to any one of claims 1 to 12 , wherein no transition metal ions other than titanium are added.

5. The method of claim 4, wherein said heating is carried out unless anatase titanium dioxide is formed as determined by Raman spectroscopy.

A method according to claim 4, wherein said heating is carried out for a period of time ranging from 0.5 to 10 hours.