Patent GB-359653-A (GB)
Title: Improvements in the manufacture and production of condensation products
IPC: C08G12/42
Filed: 1930-09-16
Abstract: For the manufacture of solutions of condensation products useful as lacquers, urea or thiourea or their derivatives and formaldehyde (or a polymer thereof), or the corresponding mono- or di-methylol compounds or the anhydrides obtainable therefrom, or mixtures of these, are heated in a practically anhydrous hydroxylated organic solvent in the presence of an inorganic dehydrating agent, e.g. calcium chloride or nitrate, zinc chloride, phosphorus pentoxide, or quicklime; the amount of dehydrating agent is from 10 to about 30 per cent of that of the urea-formaldehyde combination.  Suitable organic solvents are ethyl, n- or iso-butyl, amyl, or benzyl alcohol, ethylene glycol, and glycerol.  The condensation may be effected at a temperature below 150 DEG  C., preferably at 100-110 DEG C., under atmospheric or higher pressure.  In the examples, (1) dimethylol urea and anhydrous calcium chloride are heated at 120 DEG  C. in n-butyl alcohol; the solution obtained is treated with sodium sulphate and filtered, and may then be used as a varnish; (2) trioxymethylene is dissolved in iso-butanol with the aid of the alcoholic caustic potash, and the solution is neutralized with alcoholic hydrochloric acid; urea and anhydrous calcium chloride are then added, and the mixture heated at 105 DEG  C.; (3) dimethylol urea and dimethylol thiourea are heated to 110 DEG  C. with anhydrous calcium nitrate in benzyl alcohol; after removing the calcium nitrate, a solution is obtained which may be worked up into a lacquer with nitrocellulose. Specification 359,147 is referred to.ALSO:Urea or thiourea or their derivatives and formaldehyde (or a polymer thereof), or the corresponding mono- or di-methylol compounds or the anhydrides obtainable therefrom, or mixtures of these, are heated in a practically anhydrous hydroxylated organic solvent in the presence of an inorganic dehydrating agent, e.g. calcium chloride or nitrate, zinc chloride, phosphorus pentoxide, or quicklime; the amount of dehydrating agent is from 10 to about 30 per cent of that of the urea-formaldehyde combination. Suitable organic solvents are ethyl, n- or iso-butyl, amyl, or benzyl alcohol, ethylene glycol, and glycerol.  The condensation may be effected at a temperature below 150 DEG  C., preferably at 100-110 DEG  C., under atmospheric or higher pressure.  In the examples, (1) dimethylol urea and anhydrous calcium chloride are heated at 102 DEG  C. in n-butyl alcohol; the solution obtained is treated with sodium sulphate and filtered; it may then be used as a varnish, or the solid condensation product may be recovered by steam-distilling the solution or by treating it with a precipitant, e.g. ether; (2) trioxymethylene is dissolved in isobutanol with the aid of alcoholic caustic potash, and the solution is neutralized with alcoholic hydrochloric acid ; urea and anhydrous calcium chloride are then added, and the mixture heated at 105 DEG C.; (3) dimethylol urea and dimethylol thiourea are heated to 110 DEG C. with anhydrous calcium nitrate in benzyl alcohol; after removing the calcium nitrate, a solution is obtained which may be worked up into a lacquer with nitrocellulose.  Specificatio 359,147 is referred to.