MÉTODO PARA FORMAR POLIURETANOS TERMOPLÁSTICOS EM UMA LENTE ÓPTICA, E, LENTE OFTÁLMICA

MÉTODO PARA FORMAR POLIURETANOS TERMOPLÁSTICOS EM UMA LENTE ÓPTICA, E, LENTE OFTÁLMICA

A method of forming thermoplastic polyurethane (TPU) into an optical lens. Suitable TPUs contain urethane (-NHCOO-) repeating units that are present in at least 23% by weight. This range of urethane weights is an indicator of a flexural modulus above 1,400 MPa. The TPUs have refractive indices above...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: HAO-WEN CHIU, LEANIRITH YEAN, ROGER A. MAYR
Format: Patent
Sprache:por
Schlagworte:
PERFORMING OPERATIONS
PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCESIN A PLASTIC STATE
TRANSPORTING
WORKING OF PLASTICS
WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:A method of forming thermoplastic polyurethane (TPU) into an optical lens. Suitable TPUs contain urethane (-NHCOO-) repeating units that are present in at least 23% by weight. This range of urethane weights is an indicator of a flexural modulus above 1,400 MPa. The TPUs have refractive indices above 1.54 and Abbe numbers above 27. They have glass transition temperatures above about 100 degrees C. The selected TPU can be injection molded to form ophthalmic lenses, that are well suited for use in rimless spectacles. The lenses are highly solvent resistant, while at the same time being readily tintable. The lenses made according the invention meet FDA 21 CFR 801.41 Impact Requirement, and ANSI Z87.1 high velocity impact (HVI) standard.