METHOD FOR COLORING AND FOAMING THERMOPLASTIC POLYURETHANE Russian patent published in 2021 - IPC D06P1/00 

FIELD: polymer production.

SUBSTANCE: method for producing material of colored and foamed thermoplastic polyurethane (colored ETPU polymer) includes following stages: a) providing thermoplastic polyurethane (hereinafter – TPU) material and at least one gaseous fluid, where a melting point of TPU material is greater than the supercritical temperature; b) placing TPU material in an autoclave together with a coloring agent and/or fluorescent bleaching agent (FBA); (c) increasing pressure in the autoclave as a result of the introduction of at least one gaseous fluid at a temperature (a saturation stage) and (d) ensuring saturation of material of non-foamed TPU polymer; (e) reducing the pressure in the autoclave up to the ambient pressure so that TPU material would undergo expansion (an expansion stage), when ETPU colored polymer material is obtained, (f) extracting ETPU colored polymer material from the autoclave.

EFFECT: producing colored and foamed thermoplastic polyurethane.

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