RUTILE TITANIUM DIOXIDE MICROSPHERES AND ORDERED BOTRYOIDAL SHAPES OF SAME

20150353374

14/827406

August 17, 2015

Rutile TiO2 microspheres and microparticles in a botryoidal morphology which form from ordered acicular aggregates of elongated TiO2 crystallites that resemble nano-sized flower bouquets and/or triangular funnels, and process for their preparation by thermally hydrolyzing a soluble TiO2 precursor compound in aqueous solution in the presence of a morphology controlling agent selected from carboxylic acids and amino acids.

Cristal Inorganic Chemicals Switzerland Ltd (Baar, CH)

1-7. (canceled)

8. Rutile TiO2 microparticles which comprise generally spherical structures in the range of from 1 to 2 microns in diameter, said spherical structures comprising ordered acicular aggregates of elongated TiO2 crystallites having a thickness in the range of from 3 nm to 5 nm in which one end of each of said elongated TiO2 crystallites are joined into a cluster such that the opposite ends of each of said elongated TiO2 crystallites extend outwardly and terminate at an angle normal to the outer surface forming said spherical structure.

9. Rutile TiO2 microparticles which comprise generally spherical structures in the range of from 1 to 2 microns in diameter, said spherical structures comprising ordered acicular aggregates of elongated TiO2 crystallites, produced by the process comprising: (a) forming an aqueous solution of a soluble titanium compound at a titanium concentration of from 0.5 to 1.0 moles per liter; (b) introducing a morphology controlling agent selected from the group consisting of an α-hydroxy carboxylic acid of the formula R—CH(OH)COOH, an α-hydroxy carboxamide of the formula R—CH(OH)CONH2 or an α-amino acid of the formula R—CH(NH2)COOH, wherein R is an alkane, alkene, alkyne, arene, or cycloalkane group having 4 or fewer carbon atoms, into the solution at an acid- or carboxamide-to-titanium molar ratio of from 0.02 to 0.2 while simultaneously heating the solution to a temperature in the range of from 75° C. to 80° C. with constant stirring; (c) maintaining the stirred solution at a temperature in the range of from 75° C. to 80° C. for a period of from one to 3 hours; (d) elevating the temperature of the stirred solution to a value of from 100° C. to the refluxing temperature and maintaining said temperature for a period of from 2 hours to 4 hours to form a reaction product; (e) optionally neutralizing the reaction mixture which results from step (e); (f) cooling the reaction mixture to room or ambient temperature; and (h) separating and drying the reaction product.

10. The rutile TiO2 microparticles of claim 9 wherein said elongated TiO2 crystallites have a length of from 20 nm to 50 nm and a thickness of from 3 nm to 5 nm.

11. The rutile TiO2 microparticles of claim 10 wherein one of the ends from each of said elongated TiO2 crystallites assemble into a cluster whereby the opposite ends of each of said crystallites extend outwardly and terminate at an angle normal to the outer surface forming said spherical structure.

12. The rutile TiO2 microparticles of claim 9 wherein said morphology controlling agent is selected from lactic acid (CH3CH(OH)COOH); 2-hydroxybutyric acid (C2H5CH(OH)COOH); 2-hydroxypentanoic acid (C3H7CH(OH)COOH); 2-Hydroxyhexanoic acid (C4H9CH(OH)COOH); 2-Hydroxyisocaproic acid (CH3CH(CH3)CH2CH(OH)COOH); alanine (CH3CH(NH2)COOH); valine (CH3CH(CH3)CH(NH2)COOH); norvaline (C3H7CH(NH2)COOH); isoleucine (C2H5CH(CH3)CH(NH2)COOH); leucine (CH3CH(CH3)CH2CH(NH2)COOH); and norleucine (C4H9CH(NH2)COOH) and mixtures thereof.

13. The rutile TiO2 microparticles of claim 9 wherein said soluble titanium compound is selected from titanium oxychloride (TiOCl2), titanium oxybromide (TiOBr2), titanium oxyiodide (TiOI2), titanium oxynitrate (TiO(NO3)2), titanium trichloride (TiCl3), titanium tribromide(TiBr3), titanium oxalate (Ti2(C2O4)3), potassium hexafluorotitanate(K2TiF6), ammonium hexafluorotitanate ((NH4)2TiF6), potassium titanyloxolate (K2TiO(C2O4)2), ammonium titanyloxolate ((NH4)2TiO(C2O4)2), titanium bis(ammonium lactate) dihydroxide ([CH3CH(O)COONH4]2Ti(OH)2) and mixtures thereof.

14. The rutile TiO2 microparticles of claim 12 wherein said soluble titanium compound is selected from titanium oxychloride (TiOCl2), titanium oxybromide (TiOBr2), titanium oxyiodide (TiOI2), titanium oxynitrate (TiO(NO3)2), titanium trichloride (TiCl3), titanium tribromide(TiBr3), titanium oxalate (Ti2(C2O4)3), potassium hexafluorotitanate(K2TiF6), ammonium hexafluorotitanate ((NH4)2TIF6), potassium titanyloxolate (K2TiO(C2O4)2), ammonium titanyloxolate ((NH4)2TiO(C2O4)2), titanium bis(ammonium lactate) dihydroxide ([CH3CH(O)COONH4]2Ti(OH)2) and mixtures thereof.

15. The rutile TiO2 microparticles of claim 14 wherein said morphology controlling agent is lactic acid (CH3CH(OH)COOH), and said soluble titanium compound is titanium oxychloride (TiOCl2).

16. A method for preparing rutile TiO2 particles which comprise structures in a botryoidal morphology having a size in the range of from 10 to 20 microns, said structures being aggregates of elongated TiO2 crystallites having a thickness of from 3 nm to 5 nm, said method comprising: (a) forming an aqueous solution of a soluble titanium compound at a titanium concentration of from 0.5 to 1.0 moles per liter; (b) introducing a morphology controlling agent selected from an α-hydroxy carboxylic acid of the formula R—CH(OH)COOH, an a-hydroxy carboxamide of the formula R—CH(OH)CONH2 or an a-amino acid of the formula R—CH(NH2)COOH, wherein R is an alkane, alkene, alkyne, arene, or cycloalkane group having 4 or fewer carbon atoms, into the solution at an acid- or carboxamide-to-titanium molar ratio of from 0.02 to 0.2 while simultaneously heating the solution to a temperature in the range of from 75° C. to 80° C. with constant stirring; (c) introducing TiO2 seeds into the stirred solution at a seed-to-TiO2 molar ratio of from 0.0005 to 0.0015 and maintaining the stirred solution at a temperature in the range of from 75° C. to 80° C. for a period of from one to 3 hours; (d) elevating the temperature of the stirred solution to a value of from 100° C. to the refluxing temperature and maintaining said temperature for a period of from 2 hours to 4 hours to form a reaction product; (e) optionally neutralizing the reaction mixture resulting from step (d); (f) cooling the reaction mixture to room or ambient temperature; and (g) separating and drying the reaction product.

17. The method of claim 16 wherein said morphology controlling agent is selected from lactic acid (CH3CH(OH)COOH); 2-hydroxybutyric acid (C2H5CH(OH)COOH); 2-hydroxypentanoic acid (C3H7CH(OH)COOH); 2-Hydroxyhexanoic acid (C4H9CH(OH)COOH); 2-Hydroxyisocaproic acid (CH3CH(CH3)CH2CH(OH)COOH); alanine (CH3CH(NH2)COOH); valine (CH3CH(CH3)CH(NH2)COOH); norvaline (C3H7CH(NH2)COOH); isoleucine (C2H5CH(CH3)CH(NH2)COOH); leucine (CH3CH(CH3)CH2CH(NH2)COOH); and norleucine (C4H9CH(NH2)COOH) and mixtures thereof.

18. The method of claim 16 wherein said soluble titanium compound is selected from titanium oxychloride (TiOCl2), titanium oxybromide (TiOBr2), titanium oxyiodide (TiOI2), titanium oxynitrate (TiO(NO3)2), titanium trichloride (TiCl3), titanium tribromide(TiBr3), titanium oxalate (Ti2(C2O4)3), potassium hexafluorotitanate(K2TiF6), ammonium hexafluorotitanate ((NH4)2TiF6), potassium titanyloxolate (K2TiO(C2O4)2), ammonium titanyloxolate ((NH4)2TiO(C2O4)2), titanium bis(ammonium lactate) dihydroxide ([CH3CH(O)COONH4]2Ti(OH)2) and mixtures thereof.

19. The method of claim 17 wherein said soluble titanium compound is selected from titanium oxychloride (TiOCl2), titanium oxybromide (TiOBr2), titanium oxyiodide (TiOI2), titanium oxynitrate (TiO(NO3)2), titanium trichloride (TiCl3), titanium tribromide(TiBr3), titanium oxalate (Ti2(C2O4)3), potassium hexafluorotitanate(K2TiF6), ammonium hexafluorotitanate ((NH4)2TiF6), potassium titanyloxolate (K2TiO(C2O4)2), ammonium titanyloxolate ((NH4)2TiO(C2O4)2), titanium bis(ammonium lactate) dihydroxide ([CH3CH(O)COONH4]2Ti(OH)2) and mixtures thereof.

20. The method of claim 19 wherein said morphology controlling agent is lactic acid (CH3CH(OH)COOH), and said soluble titanium compound is titanium oxychloride (TiOCl2).

21. Rutile TiO2 microparticles comprising structures in a botryoidal morphology having a size in the range of from 10 to 20 microns and formed by the process of: (a) forming an aqueous solution of a soluble titanium compound at a titanium concentration of from 0.5 to 1.0 moles per liter; (b) introducing a morphology controlling agent selected from an α-hydroxy carboxylic acid of the formula R—CH(OH)COOH, an α-hydroxy carboxamide of the formula R—CH(OH)CONH2 or an α-amino acid of the formula R—CH(NH2)COOH, wherein R is an alkane, alkene, alkyne, arene, or cycloalkane group having 4 or fewer carbon atoms, into the solution at an acid- or carboxamide-to-titanium molar ratio of from 0.02 to 0.2 while simultaneously heating the solution to a temperature in the range of from 70° C. to 80° C. with constant stirring; (c) introducing TiO2 seeds into the stirred solution at a seed-to-TiO2 molar ratio of from 0.0005 to 0.0015 and maintaining the stirred solution at a temperature in the range of from 70° C. to 80° C. for a period of from one to 3 hours; (d) maintaining the stirred solution at a temperature in the range of from 70° C. to 80° C. for a period of from one to 3 hours; (e) elevating the temperature of the stirred solution to a value of from 100° C. to the refluxing temperature and maintaining said temperature for a period of from 2 hours to 4 hours to form a reaction product; (f) optionally neutralizing the reaction mixture resulting from step (e); (g) cooling the reaction mixture to room or ambient temperature and separating and drying the reaction product.

22. The rutile TiO2 microparticles of claim 21 wherein: (a) said morphology controlling agent is selected from lactic acid (CH3CH(OH)COOH); 2-hydroxybutyric acid (C2H5CH(OH)COOH); 2-hydroxypentanoic acid (C3H7CH(OH)COOH); 2-Hydroxyhexanoic acid (C4H9CH(OH)COOH); 2-Hydroxyisocaproic acid (CH3CH(CH3)CH2CH(OH)COOH); alanine (CH3CH(NH2)COOH); valine (CH3CH(CH3)CH(NH2)COOH); norvaline (C3H7CH(NH2)COOH); isoleucine (C2H5CH(CH3)CH(NH2)COOH); leucine (CH3CH(CH3)CH2CH(NH2)COOH); and norleucine (C4H9CH(NH2)COOH) and mixtures thereof, and (b) said soluble titanium compound is selected from titanium oxychloride (TiOCl2), titanium oxybromide (TiOBr2), titanium oxyiodide (TiOI2), titanium oxynitrate (TiO(NO3)2), titanium trichloride (TiCl3), titanium tribromide(TiBr3), titanium oxalate (Ti2(C2O4)3), potassium hexafluorotitanate(K2TiF6), ammonium hexafluorotitanate ((NH4)2TiF6), potassium titanyloxolate (K2TiO(C2O4)2), ammonium titanyloxolate ((NH4)2TiO(C2O4)2), titanium bis(ammonium lactate) dihydroxide ([CH3CH(O)COONH4]2Ti(OH)2) and mixtures thereof.

23. Rutile TiO2 microparticles in a botryoidal morphology having a size in the range of from 10 to 20 microns which comprise an assembly of generally spherical structures in the range of from 1 to 2 microns in diameter, said spherical structures comprising ordered acicular aggregates of elongated TiO2 crystallites having a thickness in the range of from 3 nm to 5 nm in which one end of each of said elongated TiO2 crystallites are joined into a cluster such that the opposite ends of each of said elongated TiO2 crystallites extend outwardly and terminate at an angle normal to the outer surface forming said spherical structure.

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edspap.20150353374