Increasing the molecular weight of polycondensates and stabilizing them, using diepoxides of sterically hindered amines

US6028129A · kind A · utility

Assignee

• Ciba Specialty Chemicals Corporation · US

Inventors

• Rudolf Pfaendner · Rimbach, DE
• Alfred Steinmann · Praroman, CH
• Heinz Herbst · Herbstein, DE
• Kurt Hoffmann · Taufkirchen, DE

Key dates

• Filing date: Jan 20, 1999
• Grant date: Feb 22, 2000
• Expiry date: Jan 20, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L77/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a process for increasing the molecular weight of polycondensates and at the same time stabilizing them, essentially without crosslinking, which comprises heating a polyamide, a polyester, a polycarbonate or a copolymer or blend of these polymers with addition of at least one diepoxide comprising terminal epoxide groups and as a further structural element a tetramethylpiperidine radical located centrally between the epoxide groups to a temperature which is above the melting point of the polymer in the case of crystalline polycondensates or above the glass point in the case of amorphous polycondensates. The invention additionally relates to mixtures comprising the corresponding diepoxides, to their use, and to polycondensates prepared from them.