3M Innovative Properties Company

Minnesota Mining and Manufacturing Company

Warren D Ketola

Richard M Fischer, Jr

Bradley D Guth

James W Riley

Geoffrey P Morris

William A Baker

Optical filters comprising a small concentration of visible light absorbing components optionally in combination with small concentrations of ultraviolet and infared absorbing components suitable for use in an illuminator for an accelerated weathering device and methods of accelerated weathering.

Optical filters for accelerated weathering devices

A method of selection of an illuminator for use in an accelerated light stability test device chamber is described that employs measuring and comparing the spectral irradiance of at least one light source for use in an illuminated device and at least one illuminator suitable for use in an accelerated weathering chamber and selecting an illuminator having certain irradiance criteria. Also described are methods of accelerated light stability testing of an illuminated display components and an accelerated light stability tcst device.

Method of accelerated testing of illuminated device components

Methods and devices for accelerated light stability testing are described. The method comprises exposing a component to light having a total irradiance at wavelengths between 300 nm and 500 nm wherein the irradiance at wavelengths ranging from 300 nm to 350 nm is less than 3.1% of the total irradiance; the irradiance at wavelengths ranging from greater than 350 nm to 380 nm ranges from 0.2% to 2.2% of the total irradiance; the irradiance at wavelengths ranging from greater than 380 nm to 420 nm ranges from 4.5% to 9.1% of the total irradiance; and the irradiance at wavelength ranging from greater than 420 nm to 500 nm ranges from about 86% to about 95% of the total irradiance.

The invention relates to optical filters comprising an opacified portion. The optical filters are preferably suitable for use in illuminators for weathering devices.

Optical filters comprising opacified portion

The present disclosure is directed to an optical filter that advantageously approximates sunlight that is both durable and stable for long periods of time when subject to harsh light intensity, thermal and moisture loads of accelerating weathering devices. The optical filter includes a glass having a lead content of between 0.5% and 50% by weight. In some examples, the filter can be constructed to have a thickness of 0.7 mm to 10 mm. In another aspect of the disclosure, the optical filter is part of an optical filter assembly suitable for manipulating spectral power distribution. The optical filter assembly includes a lead glass optical filter having a lead content of between 0.5% and 50% by weight and an ultraviolet transmissive optical filter. In one example, the ultraviolet transmissive optical filter is constructed from quartz glass. The ultraviolet transmissive optical filter can further include an infrared absorbing coating. In still another aspect of the present disclosure, an optical filter constructed from a lead glass has a thickness selected such that illumination passed through the lead glass has a first ratio and a second ratio. The first ratio is a first total irradiance for wavelengths shorter than 290 nm to a second total irradiance for wavelengths between 300 nm to 400 nm, such that the first ratio is less than 2.0&#xd7;10. The second ratio is an irradiance at 310 nm to the second total irradiance, wherein the second ratio is at least 1.2&#xd7;10.

Optical filters for manipulating spectral power distribution in accelerated weathering devices

Infusible, solvent-insoluble, solvent-dispersible, inherently tacky, elastomeric polymeric microspheres which are formed from non-ionic monomers and comprise at least one oleophilic water-emulsifiable alkyl acrylate or methacrylate ester, and a suspension polymerization technique for producing the microspheres, which includes the use of an ionic suspension stabilizer.

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Saint Paul, MN, United States of America

Warren D Ketola