Attenuation of polymer substrate degradation due to ultraviolet radiation
AssigneeKerr-McGee Chemical Corporation
InventorsBruce R. Palmer, James W. Kauffman, Penelope Stamatakis
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Abstract
Improved methods and polymer compositions are provided whereby ultraviolet radiation degradation of substrates formed of the compositions is attenuated. In accordance with the invention, ultraviolet scattering and absorbing particles having a particle size in the range of from about 0.001 micrometer to about 0.20 micrometer in diameter are dispersed in at least a surface layer of a polymer substrate.
Claims8
A method of reducing the ultraviolet radiation degradation of a polymer substrate comprising dispersing ultraviolet scattering and absorbing particles in at least a surface layer of said polymer substrate, said particles being formed of a material having a band gap in the range of from about 2.8 eV to about 4.1 eV, being of a size in the range of from about 0.001 micrometer to about 0.20 micrometer in diameter and having low opacity in the visible radiation region of the spectrum wherein the loading of said particles in said surface layer is in the range of from about 1% to about 15% by weight of said layer and particles contained therein and wherein said particles are selected from the group consisting of rutile anatase and amorphous titanium dioxide particles, wurtzite and amorphous zinc oxide particles and mixtures thereof.
A polymer composition having reduced susceptibility to degradation as a result of ultraviolet radiation comprising a polymer resin having ultraviolet scattering and absorbing particles dispersed therein, said particles being formed of a material having a band gap in the range of from about 2.8 eV to about 4.1 eV, being of a size in the range of from about 0.001 micrometer to about 0.20 micrometer in diameter and having low opacity in the visible radiation region of the spectrum wherein the loading of said particles in said composition is in the range of from about 1% to about 15% by weight of said composition and wherein said particles are selected from the group consisting of rutile anatase and amorphous titanium dioxide particles, wurtzite and amorphous zinc oxide particles and mixtures thereof.
Dependencies are inferred from the claim text.