Process for preparing polyisocyanates containing iminooxadiazinedione groups

US6107484A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Frank Richter · Frankfurt, DE
• Stefan Groth · Leverkusen, DE
• Eberhard Stelter · Neunburg vorm Wald, DE
• Wilfried Litz · Neunburg vorm Wald, DE

Key dates

• Filing date: May 25, 1999
• Grant date: Aug 22, 2000
• Expiry date: May 25, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G18/791
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for the production of trimerized polyisocyanates containing at least 30 mole % of iminooxadiazinedione groups (asymmetric trimers) in the trimer mixture by catalytically trimerizing a starting isocyanate selected from organic di- or polyisocyanates having a number average molecular weight of 140 to 600 and containing aliphatically, cycloaliphatically and/or araliphatically bound isocyanate groups in the presence of quaternary ammonium and phosphonium fluoride trimerization catalysts corresponding to the formula EQU R.sub.4 E.sup.+ F.sup.- (I), wherein PA1 E represents N or P and PA1 R represents identical or different, optionally branched, aliphatic, aromatic and/or araliphatic C.sub.1 -C.sub.20 groups, or two or more R groups may also form, with one another and with the nitrogen or phosphorus atom, saturated or unsaturated rings, PA1 in which the catalysts are PA2 i) present in pure form, PA2 ii) blended with solvating agents S for the fluoride anion, wherein S is selected from protic compounds having a pK.sub.a value of greater than 2 (determined in H.sub.2 O at 25.degree. C.) or oxalic acid, provided that the molar ratio of organic acid…