Transparent molding composition for optical applications
AssigneeDegussa AG
InventorsRoland Wursche, Dagmar Kaufhold, Berthold Teloeken
Life of this patent
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Abstract
A molding composition which is composed of at least 60% by weight of transparent polyamide, where the molding composition comprises an effective amount of one or more optical brighteners, and where the amount of the optical brightener has been judged in such a way that a) the b value, which is a measure of yellowness, is at most 7, and moreover b) between 370 and 430 nm, at least in a lower part of the range, the transmittance is smaller than 1%, measured at a layer thickness of 4 mm, can be processed to give products which are substantially impermeable to UV light.
Claims20
A molding composition comprising:
- i) at least 60% by weight of transparent polyamide;
- and
- ii) an effective amount of one or more optical brighteners, and where the amount of the optical brightener has been judged in such a way that a) the b value (DIN 53 236) is at most 7, and
- b) at a wavelength of between 370 and 430 nm, at least in a lower part of the range, the transmittance (ASTM D1003) is smaller than 1%, measured at a layer thickness of 4 mm.
A method of inhibiting the passage of UV light through an optical product comprising adding one or more optical brighteners to a molding composition which is comprised of at least 60% by weight of transparent polyamide.
An optical product comprised of a molding composition comprising:
- i) at least 60% by weight of transparent polyamide;
- and
- ii) an effective amount of one or more optical brighteners, and where the amount of the optical brightener has been judged in such a way that the b value (DIN 53 236) is at most 7.
An optical product made from a transparent polyamide, comprising
- a coating which comprises one or more optical brighteners has been applied to said product.
Dependencies are inferred from the claim text.