Microencapsulation of organic silanes and their use as self healing materials

Patent metadata

Field	Value
Publication number	US-9879142-B2
Application number	US-201314385037-A
Country	US
Kind code	B2
Filing date	Mar 13, 2013
Priority date	Mar 13, 2012
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

The disclosure provides a poly(urea-formaldehyde) microcapsule, which comprises encapsulated in the poly(urea-formaldehyde) microcapsule an organofluorine silane of the general formula (I) A 3 C(CA 2 ) m SiR 1 y X (3-y) (I), wherein in formula (I) A is either fluorine (F) or hydrogen (H), wherein at least 50% of atoms A are fluorine, X is chloro or a group RO, wherein R is a linear or branched alkyl radical of 1 to 4 carbon atoms, R 1 is a linear, branched or cyclic alkyl group of 1 to 8 carbon atoms, n=0 or 2, y=0 or 1 or 2 and m=0 to 20, encapsulated within the microcapsule. The disclosure also provides self-healing coating compositions comprising such polymeric microcapsules and methods of preventing or slowing corrosion using such coating compositions.

First claim

What is claimed is:

1. A poly(urea-formaldehyde) microcapsule, the poly (urea-formaldehyde) microcapsule comprising encapsulated within the microcapsule an organofluorine silane of the general formula (I) A 3 C(CA 2 ) p SiR 1 y X (3-y) (I), wherein in formula (I) A is either fluorine (F) or hydrogen (H), wherein at least about 50% of atoms A are fluorine, X is chloro or a group RO, wherein R is a linear or branched alkyl radical of 1 to 4 carbon atoms, R 1 is a linear, branched or cyclic alkyl group of 1 to 8 carbon atoms, y=0 or 1 or 2 and p=0 to 20.

2. The poly(urea-formaldehyde) microcapsule of claim 1 , wherein the silane has the general formula F 3 C(CF 2 ) m (CH 2 ) n SiR 1 y X (3-y) (II),
wherein in formula (II) X is chloro or a group RO and R is a linear or branched alkyl radical of 1 to 4 carbon atoms, R 1 is a linear, branched or cyclic alkyl group of 1 to 8 carbon atoms, n=0, 1 or 2, y=0 or 1 or 2 and m=0 to 18.

3. The poly(urea-formaldehyde) microcapsule of claim 2 , wherein in formula (II) m=4 to 16, n is 0, 1, or 2 and y=0, 1 or 2.

4. The poly(urea-formaldehyde) microcapsule of claim 1 , wherein the organofluorine-functional silane is 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (POTS), 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane, 1H, 1H, 2H, 2H-Perfluorodecyltriethoxysilane; 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9-heptadecafluorododecyl(trimethoxy)silane, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9-heptadecafluorododecyl(triethoxy)silane, triethoxy (1,1,2,3,3,4,4,5,5,6,6,7,7,8,8,8-hexadecafluorooctyl)silane, trimethoxy (1,1,2,3,3,4,4,5,5,6,6,7,7,8,8,8-hexadecafluorooctyl)silane, 1H, 1H 2H, 2H-perfluorooctyltrichlorosilane, 1H, 1H, 2H, 2H-Perfluorodecyltrichlorosilane or a mixture thereof.

5. The poly(urea-formaldehyde) microcapsule of claim 1 , wherein the microcapsule is made by polymerization of urea with formaldehyde, or wherein the microcapsule is made by polymerization of a mixture of melamine and urea with formaldehyde.

6. The poly(urea-formaldehyde) microcapsule of claim 1 , wherein the microcapsule has a diameter between about 10 μm to about 500 μm.

7. A method of preventing or slowing corrosion, the method comprising applying a coating composition on a substrate, wherein the coating composition comprises poly(urea-formaldehyde) microcapsules as defined in claim 1 .

8. The method of claim 7 , wherein the coating composition comprises a curable resin.

9. The method of claim 8 , wherein the curable resin is selected from the group consisting of an epoxy resin, an acrylic resin, a phenolic resin, a polyurethane resin, an alkyd resin and a polyester resin.

10. The method of claim 9 , further comprising curing the coating composition.

11. The method of claim 7 , wherein the poly (urea-formaldehyde) microcapsules are present in the coating composition in about 1% (w/w) to about 25% (w/w).

12. A method of encapsulating an organofluorine silane of the general formula (I) A 3 C(CA 2 ) p SiR 1 y X (3-y) (I), in which A is either fluorine (F) or hydrogen (H), wherein at least 50% of atoms A are fluorine, X is chloro or a group RO, wherein R is a linear or branched alkyl radical of 1 to 4 carbon atoms, R 1 is a linear, branched or cyclic alkyl group of 1 to 8 carbon atoms, y=0 or 1 or 2 and p=0 to 20 in a polymer microcapsule, the method comprising
forming an oil-in-water emulsion containing a mixture of urea and the organofluorine silane of the general formula (I),
adding formaldehyde to the oil-in-water emulsion, and
polymerizing urea and formaldehyde by in-situ polymerization to form the polymeric microcapsule, thereby encapsulating the organofluorine silane of the general formula (I) in the formed polymeric microcapsule.

13. The method of claim 12 , wherein forming the oil-in-water emulsion comprises adding urea and the organofluorine silane of the general formula (I) to an aqueous solution containing a surfactant.

14. The method of claim 13 , wherein the surfactant is ethylene maleic anhydride (EMA) copolymer or gum arabic.

15. A coating composition comprising poly(urea-formaldehyde) microcapsules, the poly (urea-formaldehyde) microcapsule comprising an organofluorine silane of the general formula (I) A 3 C(CA 2 ) p SiR 1 y X (3-y) (I), in which A is either fluorine (F) or hydrogen (H), wherein at least about 50% of atoms A are fluorine, X is chloro or a group RO, wherein R is a linear or branched alkyl radical of 1 to 4 carbon atoms, R 1 is a linear, branched or cyclic alkyl group of 1 to 8 carbon atoms, y=0 or 2 nd p=0 to 20, encapsulated within the microcapsule.

16. The coating composition of claim 15 , wherein the coating composition comprises a curable resin.

17. The coating composition of claim 16 , wherein the curable resin is selected from the group consisting of an epoxy resin, an acrylic resin, a phenolic resin, a polyurethane resin, an alkyd resin and a polyester resin.

18. The coating composition of claim 15 , wherein the poly (urea-formaldehyde) microcapsules are present in the coating composition in about 1% (w/w) to about 25% (w/w).

Assignees

• Univ Nanyang Tech

Inventors

• Yang Jinglei
• Huang Mingxing

Classifications

• B01J13/18 Primary

  In situ polymerisation with all reactants being present in the same phase · CPC title

• C08K5/5406

  containing elements other than oxygen or nitrogen · CPC title

• C08K5/5419

  containing at least one Si—C bond · CPC title

• C09D183/08

  containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen · CPC title

• C08G77/24

  halogen-containing groups · CPC title