Process for the preparation of polyhydantoins and polyparanic acids

US4005056A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Willi Dunwald · Leverkusen, DE
• Jurgen Lewalter · Odenthal, DE
• Rudolf Merten · Leverkusen, DE

Key dates

• Filing date: Jan 30, 1975
• Grant date: Jan 25, 1977
• Expiry date: Jan 30, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G73/0616
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

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.degree. to 250.degree. 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.degree. to 700.degree. C.