公开(公告)号：DE2538015A1

公开(公告)日：1977-03-03

申请号：DE2538015

申请日：1975-08-27

Applicant: BASF AG

Inventor： SLOWKA WOLFGANG DIPL CHEM DR ,  SCHLOTTERBECK DIETRICH DIPL CH

IPC: B01J13/20 ,  B01J13/02

Abstract: Addn. of at least the stoichiometric amt. of >=15- or 6-member cyclic urea derivs. opt. substd. with OH, OMe, OEt, Me or Et, or 2-oxo oxazolidines, to aq. micro-capsule dispersions at 10-60 degrees, removes free formaldehyde used to harden the capsule walls. Esp. useful for micro-capsule dispersions used for coating copying papers. Almost all the HCHO is removed in relatively short times, e.g. usually >95% in 10 h., compared with 50% removed by addn. of urea. Formation of NaOH, as when NaHSO3 is added to react with the HCHO, is avoided. In an example, 2-oxo imidazolidine (ethylene urea) is added to an aq. microcapsule dispersion. After 1 hr. no smell of HCHO is detectable.