Patent GB-347228-A (GB)
Title: Improved manufacture of condensation products
IPC: C08G12/10
Filed: 1930-01-24
Abstract: Resinous products are prepared by condensing thiodicyanodiamidine with formaldehyde in alkaline solution.  The products melt in hot water and solidify again when the solution is cooled, but if the solution is heated further after neutralizing or acidifying, polymerization occurs and products are obtained suitable for moulding and casting, or for addition to known moulding powders such as those prepared from urea or phenol and formaldehyde, phenol-sulphur condensation products, or products of the glyptal type.  Instead of using thiodicyanodiamidine as such, a solution in which it is generated may be used, e.g. a solution of cyanamide or dicyanodiamide saturated with hydrogen sulphide, or a solution obtained by reacting thiourea in alkaline solution with formaldehyde at 50-70 DEG  C. According to the examples, (1) thiodicyanodiamidine (1 mol.) and formaldehyde (1,5 mol.) are heated at 50-60 DEG  C. in the presence of caustic soda solution; the solution may be mixed with a filler such as cellulose, dried, and hot-pressed after addition of an acid salt, or it may be neutralized or feebly acidified and then further heated; (2) a mixture of dicyanodiamide or cyanamide, formaldehyde, and caustic soda solution is treated with hydrogen sulphide at 50-60 DEG  C.; the condensation product which separates out may be mixed with fillers and acids or acid salts and pressed; the fillers may also be added at an earlier stage; (3) urea is included in the reaction mixture of example 2, and the product is worked up similarly to that of example 2, potassium tetroxalate being used as the acid salt; the process may be modified by first treating the dicyanodiamide with hydrogen sulphide and then condensing the product with formaldehyde; (4) thiourea and formaldehyde are condensed in caustic soda solution at 50-70 DEG  C., and the solution is then neutralized and mixed with a solution of a urea-formaldehyde condensation product; the mixture is dried and worked up.  The Specification as open to inspection under Sect. 91 (3) (a) refers to the condensation of thiodicyanodiamidine with aliphatic aldehydes in general.  This subject-matter does not appear in the Specification as accepted.ALSO:Resinous products prepared by condensing thiodicyanodiamidine with formaldehyde in alkaline solution, and then neutralizing or acidifying, are added to moulding powders such as those prepared from urea or phenol and formaldehyde, phenolsulphur condensation products, or products of the glyptal type.  Instead of using thiodicyanodiamidine as such, a solution in which it is generated may be used, e.g. a solution of cyanamide or dicyanodiamide saturated with hydrogen sulphide, or a solution obtained by reacting thiourea in alkaline solution with formaldehyde at 50-70 DEG  C. According to the examples, (1) thiodicyanodiamidine (1 mol.) and formaldehyde (1,5 mol.) are heated at 50-60 DEG  C. in the presence of caustic soda solution, and the solution is mixed with a filler such as cellulose, dried, and hot-pressed after addition of an acid salt; (2) a mixture of dicyanodiamide or cyanamide, formaldehyde and caustic soda solution is treated with hydrogen sulphide at 50-60 DEG C.; and the condensation product which separates out is mixed with fillers and acids or acid salts and pressed; the fillers may also be added at an earlier stage; (3) urea is included in the reaction mixture of example 2, and the product is worked up similarly to that of example 2, potassium tetroxalate being used as the acid salt; (4) thiourea and formaldehyde are condensed in caustic soda solution at 50-70 DEG  C., and the solution is then neutralized and mixed with a solution of a urea-formaldehyde condensation product; the mixture is dried and worked up.