Photocatalytically-active, self-cleaning aqueous coating compositions and methods

• US 7,261,942 B2
• Filed: 03/03/2005
• Issued: 08/28/2007
• Est. Priority Date: 12/31/2002
• Status: Expired due to Term

• Current Assignee: Pureti, Inc.
• Original Assignee: Prizmalite Industries, Inc.
• Inventors: Andrews, John
• Primary Examiner(s): Koslow; C. Melissa
• Assistant Examiner(s): Hailey; Patricia L.
• Application Number:
  US11/071,505
• Publication Number:
  US 20050147744A1
• Time in Patent Office: 908 Days
• Field of Search: 502/349, 502/350, 423/582, 423/598, 423/608, 106/287.13, 106/287.19, 106/436, 106/447, 106/413, 106/430, 524/413, 524/430, 428/403, 428/621, 428/632, 428/660, 428/688, 428/689, 428/532
• US Class Current: 428/411.1
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/45 Nanoparticles
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08G 18/0823 containing carboxylate salt groups or groups forming them
• CPC Class Codes: C08G 18/8048 with compounds of C08G18/34
• CPC Class Codes: C09D 175/04 Polyurethanes
• CPC Class Codes: C09D 5/00 Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced electrically insulating plastics, resins or waxes H01B3/30; Filling pastes
• CPC Class Codes: C09D 5/1618 inorganic
• CPC Class Codes: C09D 7/61 inorganic
• CPC Class Codes: C09D 7/67 Particle size smaller than 100 nm
• CPC Class Codes: Y10T 428/12535 with additional, spatially distinct nonmetal component
• CPC Class Codes: Y10T 428/12611 Oxide-containing component
• CPC Class Codes: Y10T 428/12806 Refractory [Group IVB, VB, or VIB] metal-base component
• CPC Class Codes: Y10T 428/252 Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]

Abstract

Method for producing novel photochemically-active metal oxide-containing aqueous compositions such as TiO₂ compositions coated or sprayed and dried under ambient conditions to form novel photochemically-active, colorless coatings having strong wetability and adhesion to clear substrates such as window glass. Preferably the present compositions include a suitable wetting agent or combination of agents to improve the wetability of the Titanium peroxide-containing amorphous film, allowing thinner films to be readily applied. Also the inclusion of an acrylic aliphatic urethane polymer can replace wholly or partially the titanium peroxide sol and provide additional film forming and wetability properties. The acrylic urethane polymer reduces or eliminates the amount of titanyl peroxide that is required and thereby reduces or eliminates the yellow color.

Claims

1. A substrate coated with an aqueous coating composition comprising a metal peroxide and from 1 percent to 10 percent of the dry weight of the metal peroxide of a water soluble polymeric wetting agent.

2. The coated substrate of claim 1 in which the substrate is selected from the group consisting of a glass, a metal, a polymer, a ceramic, concrete, masonry, wood, stone and a textile.

3. The coated substrate of claim 1 in which the substrate is selected from the group consisting of a glass, a metal and a polymer.

4. The coated substrate of claim 1 in which the substrate is clear or translucent.

5. The coated substrate of claim 1 in which the substrate is clear.

6. The coated substrate of claim 1 in which the substrate is opaque.

7. A substrate coated with an aqueous coating composition comprising a metal peroxide, photochemically-active metal oxide particles having a size within the range of about 6 to 10 nanometers and a water soluble polymeric agent where the quantity of the water-soluble polymeric agent present is in the range of from about 4.8 to about 9.1 percent by weight based on the total dry weight of the components of the composition.

8. The coated substrate of claim 7 in which the substrate is selected from the group consisting of a glass, a metal, a polymer, a ceramic, concrete, masonry, wood, stone and a textile.

9. The coated substrate of claim 7 in which the substrate is selected from the group consisting of a glass, a metal and a polymer.

10. The coated substrate of claim 7 in which the substrate is clear or translucent.

11. The coated substrate of claim 7 in which the substrate is clear.

12. The coated substrate of claim 7 in which the substrate is opaque.

13. The coated substrate of claim 7 where at least some of the metal oxide particles are dissolved in the composition.

14. The coated substrate of claim 7 where all of the metal oxide particles are dissolved in the composition.

15. The coated substrate of claim 7 where the metal peroxide is amorphous is one or more of its solid states.

16. The coated substrate of claim 7 where the metal peroxide is crystalline and photocatalytic is one or more of its solid states.

17. The coated substrate of claim 7 where the metal peroxide is a titanium peroxide sol.

18. The coated substrate of claim 7 in which the water-soluble polymeric agent comprises a polyethylene oxide silane wetting agent.

19. The coated substrate of claim 7 where the quantity of photochemically-active metal oxide particles is in the range of from about 31 to about 62 percent by weight based on the total dry weight of the components of the composition.

20. The coated substrate of claim 7 where the quantity of photochemically-active metal oxide particles is in the range of from about 45 to about 48 percent by weight based on the total dry weight of the components of the composition.