Water repellent dyeing of nylon with acid dyes containing fluoroalkyls

The effect of dyeing of nylon with novel acid dyes having fluoroalkyl groups (R-f) on water repellency was investigated. At the same dye exhaustion, the contact angle of water increased in the order of R-i = CF3 < C3F7 much less than C8F17 approximate to C6F13. In the latter two cases, the nylon surface was apparently changed to water repellent. Based on the ESCA measurements. the peak area ratio of F-1s to N-1s was taken as a new measure of fluorine concentration at the surface. Those F-1s/N-1s peak ratios were highly correlated to the contact angles of water. The difference that was observed depending on Ri could be interpreted in terms of the diffusion of dyes into the bulk.