PURPOSE: To obtain a composite product uniformly and clearly dyed with high color fastness by dyeing treatment of a composite consisting of polyamide-based fibers and a polyurethane polymer using a combination of a dyeing bath containing a cationic level dyeing agent and a 2nd dyeing bath containing no level dyeing agent.
CONSTITUTION: This composite product uniformly dyed with high color fastness is obtained by dyeing at a temp. of ≥90°C a composite consisting of polyamide- based fibers and a polyurethane-dominant polymer (e.g. a leathery sheet) using a combination of the following two processes: (i) the polyurethane side is dyed using a metal complex dye bath containing a cationic level dyeing agent (e.g. an alkyl dimethylbenzylammonium chloride) and (ii) the nylon fiber side is dyed using a 2nd dyeing bath containing no such level dyeing agent. The method described above is especially effective in dyeing composites comprising ultrafine fibers ≥0.2 denier in single fiber fineness and/or bundled fibers thereof.
TANI YUTARO
KONNO YUKIO
OKAZAKI KEIICHI
