| abstract |
The present invention provides a two-layer coating system for coating substrates selected from the group consisting of PMMA, PC, PET, and PS comprising an upper layer selected from the group consisting of: a) poly(TFE/HFP) and poly(VF2/TFE/HFP), wherein the molar ratio of HFP to TFE is between about 0.9 and 1.9 and, in the case of the VF2/TFE/HFP terpolymer, the concentration of VF2 is about 19 mole %; and b) poly(TFE/perfluoro-2,2-dimethyldioxole) wherein the concentration of the perfluorodimethyldioxole is between 60 and 90 mole %; and a lower coating layer selected from the group consisting of: a) poly(VF2/TFE/HFP) wherein the ratio of TFE to HFP is between about 0.9 and 1.9 and the concentration of VF2 is between about 18 and 60% on PMMA substrates and between about 12 and 40 mole % on PC, PET, and PS substrates; b) poly(VF/TFE/HFP) wherein the ratio of TFE to HFP is between about 2.1 and 0.9 and the concentration of VF is between about 42 and 58 mole %; c) poly(VAc/TFE/HFIB) wherein the concentration of VAc is between 36 and 69 mole % and the concentration of HFIB is between 14 and 52 mole %; and d) TFE graft to PVOH wherein about 46 mole % TFE has been grafted to the PVOH; a composition prepared by the polymerization of vinyl acetate (VAc, CH3-C(O)-OCH=CH2), tetrafluoroethylene (CF2=CF2), and hexafluoroisobutylene ((CF3)2C=CH2); and a coating system for coating a substrate comprising a fluorinated copolymer having the formula VAc/TFE/HFIB wherein the VAc content is 36 to 69 mole %, the TFE content is 12 to 17 mole % and the HFIB mole % is 14 to 52 %. |