To obtain a material that can be formed into film with a sintering process even at a low processing temperature by a method for sintering a powdery thermoplastic polyurethane having a melt index, a relative solution viscosity and a Shore hardness within specific ranges, respectively.
This flexible elastic polyurethane (TPU) film is obtained by a method comprising sintering at least one kind of powdery thermoplastic polyurethane having a melt index of 20 to 100, preferably 30 to 60, a relative solution viscosity of 1.15 to 1.45, preferably 1.25 to 1.35, and a Shore hardness of 80 to 98, preferably 85 to 94, when a load of 21.2N is applied at 190°C in a heated mold. The powdery thermoplastic polyurethane can be obtained by the reaction of an organic diisocyanate, a polyol, a chain extender, if necessary, a conventional auxiliary substance and a conventional additive by the help of a heated mold. The sintering of the TPU is preferably carried out at a mold temperature of 180 to 215°C, especially 190 to 210°C.
HOPPE HANS-GEORG (DE)
WINKLER JURGEN (DE)
BRAUER WOLFGANG (DE)
WUSSOW HANS-GEORG (DE)
| JPH06206973A | 1994-07-26 |