SUPERHYDROPHOBIC POWDERS, STRUCTURE WITH SUPERHYDROPHOBIC SURFACE, AND PROCESSES FOR PRODUCING THESE

• US 20110195181A1
• Filed: 07/27/2009
• Published: 08/11/2011
• Est. Priority Date: 08/11/2008
• Status: Abandoned Application

• Current Assignee: DIC Corporation, Kawamura Institute Of Chemical Research
• Original Assignee: DIC Corporation, Kawamura Institute Of Chemical Research
• Inventors: Jin, Ren-Hua, Yuan, Jian-Jun
• Application Number:
  US13/058,391
• Publication Number:
  US 20110195181A1
• Time in Patent Office: Days
• US Class Current: 427/213.32
• CPC Class Codes: C01B 33/18 Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C
• CPC Class Codes: C08G 73/0206 Polyalkylene(poly)amines
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08K 9/02 Ingredients treated with inorganic substances
• CPC Class Codes: C08L 79/02 Polyamines
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: C09D 7/69 Particle size larger than 1000 nm
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: D06M 11/79 with silicon dioxide, silicic acids or their salts
• CPC Class Codes: D06M 2200/12 Hydrophobic properties
• CPC Class Codes: D21H 19/40 siliceous, e.g. clays
• CPC Class Codes: D21H 19/42 at least partly organic
• CPC Class Codes: D21H 21/16 Sizing or water-repelling agents

Abstract

A process for producing superhydrophobic powders comprising silica as the main component and the surface of the powders have a contact angle with water of 150° or larger; and a structure having a superhydrophobic surface comprising the powders. The process comprised: introducing hydrophobic groups into the silica present in the surface of aggregates of organic/inorganic composite nanofibers obtained by combining a polymer, which is an organic substance, with silica, which is an inorganic substance, on the order of nanometer or into the silica obtained by calcining the organic/inorganic composite nanofibers and removing the polymer there from; and thereby making powders composed of the aggregates superhydrophobic. Also provided is a superhydrophobic powders obtained by the process. The structure having a superhydrophobic surface is obtained by fixing the superhydrophobic powders to a surface of a solid substrate.

Claims

1-10. -10. (canceled)

11. A process for producing superhydrophobic powders comprising:

a step of dispersing, in a solvent,

powders composed of aggregates of organic/inorganic composite nanofibers (I) constructed with silica (B) shell which coats filaments of a polymer (A) having a linear polyethyleneimine backbone (a), or

powders composed of aggregates of nanofibers (II) containing silica (B) as a main constituent component obtained by calcining the above-mentioned aggregates of organic/inorganic composite nanofibers (I), and

a step of mixing a silane coupling agent having a hydrophobic group, and

a step of drying the powders obtained after the treatment in the former step.

14. The process for producing the superhydrophobic powders according to claim 11, wherein the nanofibers (I) or the nanofibers (II) each have a thickness of 10 to 100 nm and an aspect ratio of 10 or more, and the nanofibers (I) or the nanofibers (II) each have a size in the range of 2 to 100 μ

m.

16. A process for producing a structure with a superhydrophobic surface comprising a step of dispersing the superhydrophobic powders obtained by the production process according to claim 11 in a polymer solution or a silica sol solution, and applying and drying the resulting dispersion.

12. A process for producing superhydrophobic powders comprising:

a step of dispersing, in a solvent,

powders composed of aggregates of organic/inorganic composite nanofibers (I) constructed with silica (B) shell which coats filaments of a polymer (A) having a linear polyethyleneimine backbone (a), or

powders composed of aggregates of nanofibers (II) containing silica (B) as a main constituent component obtained by calcining the above-mentioned aggregates of organic/inorganic composite nanofibers (I), and

a step of mixing a compound having a hydrophobic group with the resulting dispersion to physically adsorb the compound to the silica (B), and

a step of drying the powders obtained after the treatment in the former step.

13. The process for producing the superhydrophobic powders according to claim 12, wherein the compound having the hydrophobic group is a hydrophobic polymer, an amphiphilic polymer, a long-chain alkyl group-containing compound of the carbon numbers 6-22, or a fluorine-containing compound.

15. The process for producing the superhydrophobic powders according to claim 12, wherein the nanofibers (I) or the nanofibers (II) each have a thickness of 10 to 100 nm and an aspect ratio of 10 or more, and the nanofibers (I) or the nanofibers (II) each have a size in the range of 2 to 100 μ

m.

17. A process for producing a structure with a superhydrophobic surface comprising a step of dispersing the superhydrophobic powders obtained by the production process according to claim 12 in a solution, and applying and drying the resulting dispersion.