公开(公告)号：DE2243857A1

公开(公告)日：1974-04-04

申请号：DE2243857

申请日：1972-09-07

Applicant: BASF AG

Inventor： ERHARDT KLAUS DR ,  PETERSEN HARRO DR ,  TEUTHER WOLFGANG DR ,  WITTMANN OTTO ,  BRUNNMUELLER FRITZ DR ,  GRABOWSKY OTTO DR ,  MAYER JOHANN DR ,  LENZ JOHANN

IPC: C08G12/12 ,  C08G9/10

Abstract: A urea-formaldehyde resin is formed by (a) reacting formaldehyde and urea of an initial molar ratio of >=3, in an aqs. soln., pH 3, until 1% of the urea has reacted to form urone gps., or by reacting as above during a time t = 10pH-2 (between 90-100 degrees C), (b) adding urea to the obtd. prod., at pH=3, such that the polar ratio HCHO:urea is 2-2.75 and condensing until the aqs. soln. of the condensate is no longer indefinitely dilutable in water at room temp., and (c) concentrating or evaporating the soln. formed to give a prod. contg. HCHO and urea in a molar ratio 1-2.75. The resin is used partic. in the mfr. of plywood and has a reduced tendency to evolve free HCHO.