Provided is a method for producing an α-azidoaniline derivative or an α,α′-diazide derivative using an aniline derivative as a starting material that includes a method for producing an α-azidoaniline derivative or an α,α′-diazide derivative represented by Formula (2), including the step of: contacting an aniline derivative represented by Formula (1) with an azidating agent in presence of water, a persulfate, and a copper compound.

##STR00001##

Provided is a method for producing an α-azidoaniline derivative or an α,α′-diazide derivative using an aniline derivative as a starting material that includes a method for producing an α-azidoaniline derivative or an α,α′-diazide derivative represented by Formula (2), including the step of: contacting an aniline derivative represented by Formula (1) with an azidating agent in presence of water, a persulfate, and a copper compound.

##STR00001##

An object, of the present invention is to provide a new liquid-repellent coating film. This object can be achieved by a coating film that has a fluorine content of less than 1 wt %, a water contact angle (droplet: 2 L) of 115 or more, and a water contact angle of 300 or more after surface friction with a PET film (under a load of 100 gf/cm.sup.2; 1500 reciprocations); and that satisfies at least one of the following regarding surface roughness indices: (a) an average surface roughness Ra of 1.6 m or more; and (b) a Wenzel roughness factor of 1.2 or more.

An object, of the present invention is to provide a new liquid-repellent coating film. This object can be achieved by a coating film that has a fluorine content of less than 1 wt %, a water contact angle (droplet: 2 L) of 115 or more, and a water contact angle of 300 or more after surface friction with a PET film (under a load of 100 gf/cm.sup.2; 1500 reciprocations); and that satisfies at least one of the following regarding surface roughness indices: (a) an average surface roughness Ra of 1.6 m or more; and (b) a Wenzel roughness factor of 1.2 or more.