METHOD OF CONVERTING A POLYMERIZABLE COMPOSITION INTO THERMOPLASTIC POLYURETHANE OF IMPROVED YELLOWNESS INDEX AND ARTICLE OBTAINED BY THIS METHOD

Method of producing a thermoplastic polyurethane having a light stabilization useful for ophthalmic applications, comprising combining precursors of a polyurethane and at least one antioxidant, and incorporating therein, either before, during or after polymerization, at least one light stabilizer, s...

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Bibliographische Detailangaben
Hauptverfasser: NEUZIL, RICHARD, CHIU, HAO-WEN, HEROD, TIMOTHY, E
Format: Patent
Sprache:eng ; fre ; ger
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Zusammenfassung:Method of producing a thermoplastic polyurethane having a light stabilization useful for ophthalmic applications, comprising combining precursors of a polyurethane and at least one antioxidant, and incorporating therein, either before, during or after polymerization, at least one light stabilizer, said method being characterized in that the antioxidant is benzenepropanoic acid, 3(1,1-dimethylethyl)-4-hydroxy-5-methyl-1,1′-[1,2-ethanediylbis(oxy-2,1-ethanediyl)]ester and the light stabilizer is bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate together with at least one additional component chosen from among phenol, 2-(5-chloro-2H-benzotriazole-2-yl)-6-(1,1-dimethylethyl)-4-methyl and 2,2′-methylenebis(6-(2H-benzotriazol-2-yl)-4-1,1,3,3-tetramethylbutyl)phenol).