GB1281871A - Infra-red reflective pigmentation - Google Patents

Abstract

1281871 I-R reflective pigments ELTRO GmbH 7 July 1955 [8 July 1954] 19739/55 Heading C4A Infra-red reflective pigments comprise an I.R. reflective inorganic base material coated with at least one layer of an I.R. penetrable organic dyestuff. The inorganic base material is one or more of a number of specified sulphides, selenides, tellurides, oxides, carbonates, ferrites sulphates, phosphates and silicates, optionally containing a heavy or rare earth metal activator and may be in the form of a waste product and/or a sintered material. The inorganic base may include organic additives such as resins, silicones, or dyes which do not affect the I.R. reflectivity, and this base is coated with an I.R. penetrable dye e.g. of the aniline type, or an indanthrene, azo, alizarine, quinoline, resorcine, thiazine or triphenyl methane dye. An intermediary protective colloid layer of sodium or potassium silicate, beryllium or zinc hydroxide may be interposed between the base and dye layers, and the final product may be treated with a further colloid, or an oleate, stearate, wax, or surface-active sulphonate, to increase its hygroscopicity and prevent agglomeration. Inorganic base pigments exemplified are (I) Zn sulphoselenide containing Cu and Co. (II) lithopone+ ZnS+CdS containing Cu and Co. (III) ZnS+ BaSO 4 +CdSe+MgCl 2 . (IV) MgO+BaCO 3 + Fe 2 O 3 +SiO 2 +KCl. (V) hydrated Al silicate + MgO. (VI) that of Example (I)+hydrated Al silicate. (VII) Cd sulphoselenide containing Ag, +PbS+Al 2 (SiO 3 ) 3 . (VIII) MgO+Al 2 O 3 + wax+a ZnS/CdS mixed crystal. (IX) that of Example (III) + chamotte + hydrated Al silicate. In Example (X) the base of Example (II) mixed with a naphthol, Na 2 CO 3 , Na acetate, Al 2 (SO 4 ) 3 and BaCl 2 is treated with Bordeaux B to give a dark olive pigment.