| 摘要 |
PROBLEM TO BE SOLVED: To provide an IR absorption filter which has steep absorption in a near IR region, high light transparency in a visible region and makes it possible to obtain good weatherability, workability and productivity without having large absorption of a specific wavelength in a visible region by incorporating a material having an absorption area at a specific wavelength in an associated body state of molecules. SOLUTION: The molecules of the IR absorption filter contains the material having the absorption at a wavelength 750 to 1100 nm in the associated body state. The associated bodies are preferably dispersed into a polyester resin containing ionic groups in a range of 20 to 1000 eq/ton. Further, the specific gravity of the polyester resin which is the binder preferably exists in a range of 1.05 to 1.35 and the glass transition temperature thereof is >=45 deg.C. The polyester resin consists of polyvalent carboxylic acids and polyhydric alcohols. The polyvalent carboxylic acids are exemplified by terephthalic acid, isophthalic acid, etc., and the polyhydric alcohols are exemplified by aliphatic polyhydric alcohols, alicyclic polyhydric alcohols, etc.
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