Pvb film with high uv protection and low yellowness index for laminated safety glazings
AssigneeKuraray Europe GmbH
InventorsPhillipp Lellig, Uwe Keller
Life of this patent
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Abstract
The invention relates to a plasticizer-containing polyvinyl acetal film which has a transmission of less than 20% and a yellowness index db of less than 3 at 400 nm, containing at least one UV absorber of formula where R1 is H or halogen and R2 and R3 are C1-20 alkyl-, hydroxyalkyl-, alkoxyalkyl-, acyloxyalkyl groups, optionally substituted by aldehyde, keto or epoxide groups, and an antioxidant of formula where R is hydrocarbon residue of a polyfunctional alcohol, an oligoglycol with 1 to 10 glycol units, or a hydrocarbon group with 1 to 20 carbon atoms, and s=1, 2, 3 or 4.
Claims11
A plasticizer-containing film comprising at least one polyvinyl acetal, at least one plasticizer, and further comprising:
- as a UV absorber, 0.5 to 5 wt. % of one or more compounds of the formula (1)
- where R1 is H or a halogen and R2 and R3 are alkyl-, hydroxyalkyl-, alkoxyalkyl-, or acyloxyalkyl groups having 1 to 20 carbon atoms, each optionally substituted by aldehyde, keto or epoxide groups;
- and
- as an antioxidant, 0.005-0.5 wt. % of at least one compound of the formula (3)
- where R is a hydrocarbon residue of a polyfunctional alcohol, or an oligoglycol with 1 to 10 glycol units, or a hydrocarbon group with 1 to 20 carbon atoms and x is 1, 2, 3 or 4,
- wherein the plasticizer-containing film, in a thickness of 0.76 mm measured between 2×2 mm float glass, has a transmission of less than 20% according to EN 410 and a yellowness index db of less than 3 at 400 nm,
Dependencies are inferred from the claim text.