CNT/FLUOROPOLYMER COATING COMPOSITION

• US 20100055450A1
• Filed: 08/26/2008
• Published: 03/04/2010
• Est. Priority Date: 08/26/2008
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Skorokhod, Vlad, Gardner, Sandra, Hu, Nan-Xing, Zhang, Qi, QI, Yu
• Granted Patent: US 9,441,131 B2
• Time in Patent Office: Days
• US Class Current: 428/336
• CPC Class Codes: C08K 3/041 Carbon nanotubes
• CPC Class Codes: C08K 5/005 Stabilisers against oxidation, heat, light, ozone
• CPC Class Codes: C09D 127/12 containing fluorine atoms
• CPC Class Codes: C09D 127/18 Homopolymers or copolymers of tetrafluoroethene
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

Exemplary embodiments provide nanotube-containing coating compositions and methods for making and using the coating compositions. In an exemplary embodiment, the coating composition can include a plurality of nanotubes (e.g., carbon nanotubes (CNTs)) dispersed stably and uniformly in a polymer matrix containing fluoropolymers. The coating composition can further include stabilizers to allow a stable and/or uniform dispersion of the plurality of nanotubes in the fluoropolymers. The nanotube coating composition can be coated on an article surface to improve mechanical robustness, and electrical and thermal conductivity of the coated article. The coated article can be used as, for example, a fuser member, a fixing member, a pressure roller, or a release agent donor member in an electrostatographic printing machine or process.

Claims

1. A coating composition comprising:

a fluoropolymer;

a plurality of nanotubes dispersed in a media; and

a stabilizer mixed with the fluoropolymer and the plurality of nanotubes in the media, the stabilizer allowing a stable dispersion of the plurality of nanotubes in the media and in the fluoropolymer.

2. The composition of claim 1, wherein the stabilizer is a material selected from the groups consisting of polymeric amines, polymeric acids, conjugated polymers, and natural gum materials.

3. The composition of claim 1, wherein the stabilizer is a material selected from the groups consisting of polyallylamine, polyethylenimine, poly(diallyldimethylammonium chloride), poly(allylamine hydrochloride), and mixtures thereof.

4. The composition of claim 1, wherein the stabilizer is selected from the group consisting of poly(acrylic acid), poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene) complexes with a polymeric acid, Gum Arobic, chitosan, and mixtures thereof.

5. The composition of claim 1, wherein the stabilizer is a polyallyamine having a molecular weight ranging from about 300 to about 100,000.

6. The composition of claim 1, wherein the media has a pH value ranging from about 3 to about 10.

7. The composition of claim 1, wherein each of the plurality of nanotubes comprises a single wall carbon nanotube (SWCNT), a multi-wall carbon nanotube (MWCNT), or the mixtures thereof.

8. The composition of claim 1, wherein each of the plurality of nanotubes has an inside diameter ranging from about 0.5 nanometer to about 20 nanometers as well as an outside diameter ranging from about 1 nanometer to about 80 nanometers, and has an aspect ratio ranging from about 1 to about 10000.

9. The composition of claim 1, wherein the media for the plurality of nanotubes is a liquid selected from a group consisting of water, an alcohol, an aliphatic hydrocarbon of from C5 to about C18, an aromatic hydrocarbon of from C6 to C18, an ether, a ketone, an amide, and mixtures thereof.

10. The composition of claim 1, wherein the plurality of nanotubes is present in an amount from about 0.01 percent to about 20 percent by weight of the fluoropolymer.

11. The composition of claim 1, wherein the fluoropolymer comprises a monomeric repeat unit that is selected from the group consisting of tetrafluoroethylene, perfluoro(methyl vinyl ether), perfluoro(propyl vinyl ether), perfluoro(ethyl vinyl ether), vinylidene fluoride, hexafluoropropylene, and mixtures thereof.

12. The composition of claim 1, wherein the fluoropolymer comprises a fluororesin selected from the group consisting of polytetrafluoroethylene, copolymer of tetrfluoroethylene and hexafluoropropylene, copolymer of tetrafluoroethylene and perfluoro(propyl vinyl ether), copolymer of tetrafluoroethylene and perfluoro(ethyl vinyl ether), and copolymer of tetrafluoroethylene and perfluoro(methyl vinyl ether).

13. The composition of claim 1, wherein the fluoropolymer is in a form of colloid dispersion, latex, suspension, or mixtures thereof.

14. The composition of claim 1, wherein the fluoropolymer is in a form of particle dispersion with an average particle size ranging from about 10 nanometers to about 5000 nanometers.

15. The composition of claim 1, wherein the fluoropolymer comprises one or more of a small particle with an average particle size ranging from about 50 nanometers to about 500 nanometers and a large particle with an average particle size ranging from about 1 micrometer to about 50 micrometers.

16. The composition of claim 1, further comprising one or more filler particles, the filler particles comprising metal oxides, silicon carbide, boron nitride, and graphite, wherein the metal oxides are selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, zinc oxide, tin oxide, iron oxide, magnesium oxide, manganese oxide, nickel oxide, copper oxide, antimony pentoxide, indium tin oxide, and mixtures thereof.

17. The composition of claim 1, further comprising,

a plurality of fluoropolymer latex particles of about 10 percent to about 50 percent by weight of the coating composition,

a plurality of carbon nanotubes of about 0.1 percent to about 10 percent by weight of the coating composition,

a polyallyamine stabilizer of about 0.1 percent to about 10 percent by weight of the coating composition,

a water media of about 50 percent to about 90 percent by weight of the coating composition, and

optionally, one or more fillers of about 0.5 percent to 10 percent by weight of the coating composition.

18. A coated article comprising:

a substrate, and

a coated layer disposed over the substrate and formed from applying the coating composition of claim 1 to the substrate.

19. The coated article of claim 18, wherein the coated layer is formed by heating at a temperature ranging from about 200°

C. to about 400°

C.

20. The coated article of claim 18, wherein the coated layer has a thickness ranging from about 5 microns to about 50 microns.

21. The coated article of claim 18, wherein the coated layer has a surface resistivity of about 10⁸ Ω

/sq or less.

22. The coated article of claim 18, wherein the substrate is formed of a material selected from the group consisting of metals, plastics, and ceramics,

wherein the metals are selected from the group consisting of aluminum, anodized aluminum, steel, nickel, copper, and mixtures thereof, and

wherein the plastics are selected from the group consisting of polyimides, polyester, PEEK, poly(arylene ether)s, polyamides and mixtures thereof.

23. The coated article of claim 18, wherein the substrate is in a form of a cylinder, a belt or a sheet.

24. The coated article of claim 18, further comprising one or more functional layers disposed between the substrate and the coated layer.

25. The coated article of claim 18, wherein the coated article is suitable for use in an electrostatographic printing machine and used as a fuser roll, a fixing roll, a pressure roller, and a release agent donor roll.