abstract |
Process for the preparation of polyhydantoins or polyparabanic acids, characterized in that bis- or polyglycine derivatives or bis- or poly-monoamidooxalic acid derivatives are heated to temperatures of 20° to 250° C with di- or polyiso(thio)cyanate derivatives without solvents and the highly fluid melt which has a melt viscosity of at the most 40,000 m.Pa.s. is optionally subjected to a shaping process and is polycondensed by adjustment to the reaction of 80° to 700° C. |