| abstract |
A process for anchoring paving or jointing sand for paving slabs comprises applying a homogeneous 3.0-7.0 wt.% aq. soln. of water-soluble prepolymer (I) to the sand, to form a layer of synthetic resin. (I) is obtd. by reaction of a polyoxyalkylene cpd. of mol. wt. 1000-20,000 contg. at least 2 terminal OH gps. (II) with an equiv. amt. of excess of polyisocyanate (III) (w.r.t. OH gps. in II). (II) is, e.g. a polyether-polyol such as PEG 1000-4000, obtd. by reaction of alkylane oxide with OH-contg. starter mols. such as ethylene glycol, TMP, sorbitol etc.; (III) is, e.g. TDI, MDI, NDI, XDI, HMDI etc.. USE/ADVANTAGE - The process enables sand used for bedding and jointing paving slabs etc. to be anchored and stabilised against the action of rainwater, wind, mechanical vibration etc. without losing the buffering/cushioning properties of the sand (constrast sand/cement mixts.). |