Coated hollow metal tubes and process for producing coated hollow metal tubes processed by bending, pressing or punching

A hollow metal tube coated with a thin film of a thermoplastic crystalline copolyester and being processable by bending, pressing or punching without the cracking or peeling of the coating;

• said hollow metal tube having a thin coating adhered tightly to the outer surface thereof of a thermoplastic crystalline copolyester composed of 95 to 75 mole%, based on its entire recurring units, of ethylene terephthalate units and 5 to 25 mole%, based on its entire recurring units, of a copolymerizable ester-forming unit other than the ethylene terephthalate unit and having a second order transition point of at least 50.degree. C.;
• said coating having a degree of crystallization of more than 1% and not more than 15%, and not more than 1/2.5 of its crystallizing ability, said polyester having a crystallizing ability of at least 10%, said crystallizing ability being the degree of crystallization attained when the copolyester in a substantially amorphous state is maintained at 150.degree. C. for 3 hours, and said coating having a thickness of 50 to 300 microns.

A hollow metal tube coated with a thin film of a thermoplastic crystalline copolyester and being processable by bending, pressing or punching without the cracking or peeling of the coating;

• said hollow metal tube having a thin coating adhered tightly to the outer surface thereof of a thermoplastic crystalline copolyester composed of 95 to 80 mole%, based on its entire recurring units, of ethylene terephthalate units and 5 to 20 mole%, based on its entire recurring units, of a copolymerizable neopentyl terephthalate unit and having a second order transition point of at least 50.degree. C., said coating having a degree of crystallization of more than 1% and not more than 10%, and not more than 1/3 of its crystallizing ability, said polyester having a crystallizing ability of at least 15%, said crystallizing ability being the degree of crystallization attained when the copolyester in a substantially amorphous state is maintained at 150.degree. C. for 3 hours, and said coating having a thickness of 50 to 300 microns.