Polyurethane nanocomposites

Patent metadata

Field	Value
Publication number	US-9540479-B2
Application number	US-97869910-A
Country	US
Kind code	B2
Filing date	Dec 27, 2010
Priority date	Dec 29, 2009
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

Polyurethane nanocomposites are provided which include a polyurethane and surface modified silica nanoparticles covalently bound into the polyurethane. High loadings in excess of 30% may be achieved. In some embodiments, the silica nanoparticles are covalently bound to the polyurethane polymer through a linkage derived from a surface-modifying compound comprising a silane functional group and a polyol segment. In some embodiments the polyurethane nanocomposite may be provided as a tape or film. In addition, precursors for a polyurethane nanocomposites are provided comprising: a first polyol and surface modified silica nanoparticles dispersed within the first polyol. In some embodiments, the silica nanoparticles are surface-modified by reaction with a surface-modifying compound comprising a silane functional group and a polyol segment derived from a second polyol, which may be the same or different from the first polyol.

First claim

We claim:

1. An erosion resistant film comprising a polyurethane nanocomposite comprising:
a) a polyurethane polymer, and
b) surface modified silica nanoparticles dispersed within and covalently bound to the polyurethane polymer;

wherein the silica nanoparticles are covalently bound to the polyurethane polymer through a linkage derived from a first surface-modifying compound comprising a polyol to which a silane group is added by reaction with a compound comprising a silane or silane-generating group and an isocyanate group; and
wherein said silica nanoparticles have a number average particle size of between 10 and 200 nanometers (nm); wherein the polyurethane nanocomposite has a silica content of greater than 12% by weight.

2. The erosion resistant film according to claim 1 wherein the polyurethane nanocomposite has a silica content of greater than 18% by weight.

3. The erosion resistant film according to claim 1 wherein the polyurethane nanocomposite has a silica content of greater than 30% by weight.

4. The erosion resistant film according to claim 1 wherein the polyol has a molecular weight of at least 500.

5. A tape comprising the erosion resistant film of claim 1 and a pressure sensitive adhesive.

6. The erosion resistant film according to claim 1 wherein said surface modified silica nanoparticles exhibit a multimodal particle size distribution.

7. The erosion resistant film according to claim 1 wherein said surface modified silica nanoparticles are surface-modified by reaction with a second surface-modifying compound comprising a silane functional group and having a molecular weight of less than 350.

8. The erosion resistant film according to claim 7 wherein said second surface-modifying compound comprises no polyol segment.

9. The erosion resistant film according to claim 1 wherein said polyurethane comprises an acrylate component capable of radiation-induced crosslinking.

10. The erosion resistant film according to claim 1 wherein the polyurethane is not a polyurea nor a mixed polyurethane/polyurea.

11. The erosion resistant film according to claim 1 wherein the compound comprising a silane or silane-generating group and an isocyanate group is 3-triethoxysilylpropylisocyanate.

12. The erosion resistant film according to claim 1 wherein said surface modified silica nanoparticles are surface-modified by reaction with a second surface-modifying compound which is n-triethoxypropylsilane.

13. An erosion resistant film comprising a polyurethane nanocomposite comprising:
a) a polyurethane polymer, and
b) surface modified silica nanoparticles dispersed within and covalently bound to the polyurethane polymer; wherein the polyurethane nanocomposite has a silica content of greater than 12% by weight;

wherein the silica nanoparticles are covalently bound to the polyurethane polymer through a linkage derived from a first surface-modifying compound comprising a polyol to which a silane group is added by reaction with a compound comprising a silane or silane-generating group and an isocyanate group,
wherein said surface modified silica nanoparticles are surface-modified by reaction with a second surface-modifying compound comprising a silane functional group and having a molecular weight of less than 800; wherein said second surface-modifying compound comprises no polyol segment; and
wherein the polyurethane is not a polyurea nor a mixed polyurethane/polyurea.

14. The erosion resistant film according to claim 13 wherein said second surface-modifying compound has a molecular weight of less than 350.

15. The erosion resistant film according to claim 13 wherein the polyurethane nanocomposite has a silica content of greater than 30% by weight.

16. The erosion resistant film according to claim 13 wherein said polyurethane comprises an acrylate component capable of radiation-induced crosslinking.

17. The erosion resistant film according to claim 13 wherein the compound comprising a silane or silane-generating group and an isocyanate group is 3-triethoxysilylpropylisocyanate.

18. The erosion resistant film according to claim 13 wherein said second surface-modifying compound is n-triethoxypropylsilane.

Assignees

• Marx Ryan E
• Schultz William J
• Thompson Wendy L
• 3M Innovative Properties Co

Inventors

• Marx Ryan E
• Schultz William J
• Thompson Wendy L

Classifications

• C08J5/005 Primary

  Reinforced macromolecular compounds with nanosized materials, e.g. nanoparticles, nanofibres, nanotubes, nanowires, nanorods or nanolayered materials · CPC title

• C08G18/718 Primary

  containing silicon · CPC title

• C08G18/242

  organometallic compounds containing tin-carbon bonds · CPC title

• B05D3/06

  by exposure to radiation (B05D3/02 takes precedence {; plasma treatment B05D3/141}) · CPC title

• C08G18/755

  and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate · CPC title