Heat and sound insulating sand-lime bricks or mouldings - which contain pores produced by adding foamed surfactants to sand-lime mixt.

摘要

The insulating properties of the bricks are produced by porosity, which is achieved by adding foamed anionic tensides plus glycol derivs. and urea to the sand-lime mixt., before the bricks or similar prefabricated mouldings are dried and hardened by pressurised steam. The pref. foamant is a mixt.(I) contg. 22% alkylether-sulphate, 16% ethylene glycol, 6.5% urea, and 55.5% water. The porosity in the bricks etc. is pref. adjusted within wide limits by varying the amt. of mixt. (I) employed. The basic mixt. of sand and lime is pref. stirred with water to make a slurry, to which mixt. (I) is added; and 0.5-10 wt.% cement is pref. used to aid setting and drying of the bricks. The main patent 2930645, and its addn. 2933787, described bricks and other mouldings which could be made without using pressure, and has a low density. The present invention provides bricks or mouldings with any desired shape; with an adjustable density; and with adjustable insulating properties.