Biodegradable polymers, process for producing them and their use in preparing biodegradable moldings

US5889135A · kind A · utility

Assignee

• BASF SE

Inventors

• Volker Warzelhan · Bad Dürkheim, DE
• Gunter Pipper · Bad Dürkheim, DE
• Ursula Seeliger · Ludwigshafen, DE
• Peter Bauer · Ludwigshafen, DE
• Udo Pagga · Ludwigshafen, DE
• Motonori Yamamoto · Mannheim, DE

Key dates

• Filing date: Aug 14, 1997
• Grant date: Mar 30, 1999
• Expiry date: Aug 14, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02W30/40
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Biodegradable polyesters having a molecular weight (M.sub.n) of from 5000 to 50,000 g/mol (measured by gel permeation chromatography), a viscosity number of from 30 to 350 g/ml (measured in 50:50 by weight of o-dichlorobenzene/phenol at a concentration of 0.5% by weight of polyester at 25.degree. C.), and a melting point of from 50 to 170.degree. C., and having both hydroxyl and carboxyl end groups, the molar ratio of carboxyl end groups to hydroxyl end groups being greater than one, which is obtained by reacting a mixture consisting essentially of PA1 a.sub.1) a mixture consisting essentially of PA2 from 45 to 80 mol % of adipic acid or ester-forming derivatives thereof, or mixtures thereof, PA2 from 20 to 55 mol % of terephthalic acid or ester-forming derivatives thereof, or mixtures thereof, and PA2 from 0 to 5 mol % of a sulfonate compound, PA2 where the sum of the individual mole percentages is 100 mol %, and PA1 a.sub.2) a dihydroxy compound selected from the group consisting of C.sub.2 -C.sub.6 -alkanediols and C.sub.5 -C.sub.10 -cycloalkanediols, in the presence of from 0.01 to 5 mol %, per mol of component a.sub.1), of a compound D having at least three groups capable of e…