a solids content of from about 44 to 45 by weight or water glasses having a viscosity of at least about 400 cp 25 c the nature of the isocyanates used for preparing the dispersions is not critical although they should best have such a high boiling point that they do not evaporate to any significant extent at 100 u00b0 c this prevents significant quantities of the adhesive from volatilizing with the waste air during application or hardening of the adhesive as may be the case with conventional adhesives suitable isocyanates are monisocyanates such as n octyl isocyanate cyclohexyl isocyanate and phenyl isocyanate polyisocyanates such as aliphatic cycloaliphatic araliphatic aromatic and heterocyclic polyisocyanates of the type described for example by w siefken in justus liebigs annalen der chemie 562 pages 75 to 136 and in polyurethanes chemistry and technology volume i chemistry by saunders and frisch l963 especially pages 17 to 48 for example 1 6 hexamethylene diisocyanate 1 l2 dodecane diisocyanate cyclobutane 1 3 diisocyanate cyclohexane 1 3 and 1 4 diisocyanate also mixtures of these isomers 1 isocyanato 3 3 5 trimethyl 5 isocyanatomethyl cyclohexane das no 1 202 785 u s pat no 3 401 190 incorporated herein by reference 2 4 and 2 6 hexahydro tolylene diisocyanate also mixtures of these isomers hexahydro 1 3 and or 1 4 phenylene diisocyanate perhydro 2 4 39 and or 4 4 39 diphenyl methane diisocyanate 2 4 and 2 6 tolylene diisocyanate also mixtures of these isomers diphenyl methane 2 4 39 and or 4 4 39 diisocyanate naphthylene 1 5 diisocyanate triphenyl methane 4 4 39.