Ceramic filters or thermal and sound insulating building elements - where initial mixts. of clays, stone, etc. are treated with expansion agent contg. surfactant, glycol, urea and water

摘要

This is an addn. to 2930645, which described the mfr. of ceramic filters etc. The porosity required to provide the filtration or insulating properties is obtd. by treating suitable ceramics or building materials with foamed anionic tensides used in conjunction with glycol derivs. and urea. The resulting mixt. is then dried or baked to obtain the required prod. The ceramic or building materials (I) are pref. treated with a mixt. (II) contg. 22% alkyl-ether sulphate, 16% ethylene glycol, 6.5% urea, and 55.5% water; and the porosity in the prods. is pref. adjusted by varying the amt. of mixt. (II) added to materials (I). Used in the mfr. of filters; expanded concrete; lightweight sanitary ceramic ware; and esp. heat and sound insulating bricks and gypsum building elements. Low cost materials (I) can be used; and baking can be eliminated or its cost reduced.