METHOD FOR PRODUCING SURFACE-MODIFIED NANOPARTICULATE METAL OXIDES, METAL HYDROXIDES, AND/OR METAL OXIDE HYDROXIDES

• US 20100119829A1
• Filed: 03/18/2008
• Published: 05/13/2010
• Est. Priority Date: 03/23/2007
• Status: Abandoned Application

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Andre, Valerie, Hu, Jing, Rieger, Jens, Voss, Hartwig, Hibst, Hartmut, Karpov, Andrey, Schierle-Arndt, Kerstin, Bechtloff, Bernd
• Application Number:
  US12/532,663
• Publication Number:
  US 20100119829A1
• Time in Patent Office: Days
• US Class Current: 428/407
• CPC Class Codes: A61K 2800/413 Nanosized, i.e. having sizes below 100 nm
• CPC Class Codes: A61K 2800/614 By macromolecular compounds
• CPC Class Codes: A61K 8/0241 Containing particulates characterized by their shape and/or structure see also A61K8/04, A61K8/11, and A61K8/14, further aspects are classified in A61K2800/40 and subcodes
• CPC Class Codes: A61K 8/27 Zinc; Compounds thereof
• CPC Class Codes: A61K 8/8147 Homopolymers or copolymers of acids; Metal or ammonium salts thereof, e.g. crotonic acid, (meth)acrylic acid; Compositions of derivatives of such polymers
• CPC Class Codes: A61Q 17/005 Antimicrobial preparations
• CPC Class Codes: A61Q 17/04 Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 13/36 by precipitation reactions in aqueous solutions C01B13/328 takes precedence
• CPC Class Codes: C01P 2002/60 Compounds characterised by their crystallite size
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/22 Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C09C 1/028 Compounds containing only magnesium as metal
• CPC Class Codes: C09C 1/043 Zinc oxide
• CPC Class Codes: C09C 1/24 Oxides of iron
• CPC Class Codes: C09C 1/3676 Treatment with macro-molecular organic compounds
• CPC Class Codes: C09C 1/407 : Aluminium oxides or hydroxides
• CPC Class Codes: C09C 3/10 : Treatment with macromolecular organic compounds C09C3/006 takes precedence
• CPC Class Codes: Y10T 428/2998 : including synthetic resin or polymer

Abstract

The present invention relates to methods of producing surface-modified nanoparticulate particles at least of one metal oxide, metal hydroxide and/or metal oxide hydroxide, and aqueous suspensions of these particles. Furthermore, the invention relates to the surface-modified nanoparticulate particles, obtainable by these methods, at least of one metal oxide, metal hydroxide and/or metal oxide hydroxide and aqueous suspensions of these particles, and to their use for cosmetic sunscreen preparations, as stabilizer in plastics and as antimicrobial active ingredient.

Claims

1-21. -21. (canceled)

22. A method of producing surface-modified nanoparticulate particles at least of one metal oxide, metal hydroxide and/or metal oxide hydroxide, where the metal or the metals are selected from the group consisting of aluminum, magnesium, cerium, iron, manganese, cobalt, nickel, copper, titanium, zinc and zirconium, comprising the steps

a) producing a solution of water and at least one metal salt of the abovementioned metals (solution 1) and a solution of water and at least one strong base (solution 2), where at least one of the two solutions 1 and 2 comprises at least one polyacrylate, where the polyacrylate

is a polymer based on at least one α

,β

-unsaturated carboxylic acid, where the fraction of the at least one α

,β

-unsaturated carboxylic acid in the polyacrylates is between 50 and 100 mol %, or

is a polymer which has been prepared from 100 mol % of acrylic acid,

b) mixing the solutions 1 and 2 produced in step a) at a temperature in the range from 0 to 120°

C., during which the surface-modified nanoparticulate particles are formed and precipitate out of the solution to form an aqueous suspension,

c) separating off the surface-modified nanoparticulate particles from the aqueous suspension obtained in step b), and

d) drying the surface-modified nanoparticulate particles obtained in step c).

23. The method according to claim 22, wherein the metal salt is zinc chloride, zinc nitrate, zinc acetate or titanium tetrachloride.

24. The method according to claim 22, wherein the strong base is an alkali metal hydroxide, an alkaline earth metal hydroxide or ammonia.

25. The method according to claim 22, wherein the polyacrylate has a molecular weight in the range from 800 to 250 000 g/mol.

26. The method according to claim 22, wherein at least one of the process steps a) to d) is carried out continuously.

27. A surface-modified nanoparticulate particle comprising at least of one metal oxide, metal hydroxide and/or metal oxide hydroxide, wherein the metal or the metals are selected from the group consisting of aluminum, magnesium, cerium, iron, manganese, cobalt, nickel, copper, titanium, zinc and zirconium, and the surface modification comprises a coating with at least one polyacrylate with a BET surface area in the range from 25 to 500 m²/g, obtainable by the method according to claim 22.

28. The surface-modified nanoparticulate particle according to claim 27 with a diameter of from 10 to 200 nm.

29. A process to make an article which comprises utilizing the surface-modified nanoparticulate particles as claimed in claim 27, wherein the article is a UV protectant in cosmetic sunscreen preparations, a stabilizer in plastics or an antimicrobial active ingredient.

30. The process according to claim 29, wherein the particles comprise zinc oxide or titanium dioxide.

31. A method of producing an aqueous suspension of surface-modified nanoparticulate particles at least of one metal oxide, metal hydroxide and/or metal oxide hydroxide, where the metal or the metals are selected from the group consisting of aluminum, magnesium, cesium, iron, manganese, cobalt, nickel, copper, titanium, zinc and zirconium, comprising the steps

a) producing a solution of water and at least one metal salt of the abovementioned metals (solution 1) and a solution of water and at least one strong base (solution 2), wherein at least one of the two solutions 1 and 2 comprises at least one polyacrylate, where the polyacrylate

is a polymer based on at least one α

,β

-unsaturated carboxylic acid, where the fraction of the at least one α

,β

-unsaturated carboxylic acid in the polyacrylates is between 50 and 100 mol %, or

is a polymer which has been prepared from 100 mol % of acrylic acid,

b) mixing the solutions 1 and 2 produced in step a) at a temperature in the range from 0 to 120°

C., during which the surface-modified nanoparticulate particles are formed and precipitate out of the solution to form an aqueous suspension, and

c) optionally concentrating the formed aqueous suspension and/or separating off by-products.

32. The method according to claim 31, wherein the metal salt is zinc chloride, zinc nitrate, zinc acetate or titanium tetrachloride.

33. The method according to claim 31, wherein the strong base is an alkali metal hydroxide, an alkaline earth metal hydroxide or ammonia.

34. The method according to claim 31, wherein the polyacrylate comprises between 50 and 100 mol % of at least one α

,β

-unsaturated carboxylic acid.

35. The method according to claim 31, wherein the polyacrylate has a molecular weight in the range from 800 to 250 000 g/mol.

36. The method according to claim 31, wherein at least one of the process steps a) to c) is carried out continuously.

37. An aqueous suspension of surface-modified nanoparticulate particles at least of one metal oxide, metal hydroxide and/or metal oxide hydroxide, where the metal or the metals are selected from the group consisting of aluminum, magnesium, cerium, iron, manganese, cobalt, nickel, copper, titanium, zinc and zirconium, and the surface modification comprises a coating with at least one polyacrylate, obtainable by a method according to claim 31.

38. An aqueous suspension according to claim 37, where the particles have a diameter of from 10 to 200 nm.

39. The aqueous suspension according claim 37, where the polyacrylate is a polyacrylic acid.

40. A process to make an article which comprises utilizing the surface-modified nanoparticulate particles as claimed in claim 37, wherein the article is a UV protectant in cosmetic sunscreen preparations, a stabilizer in plastics or an antimicrobial active ingredient.

41. The process according to claim 40, wherein the particles comprise zinc oxide or titanium dioxide.