Amino resins, useful as binders for derived timber prods. - contain specified urea derivs. obtd. by reaction of urea with poly:amine(s)

摘要

Amino resins (II). contain at least 0.5 wt. % urea deriv. of formula A-NH-Z-N(A)n-H (IIIA) or A-NH-R5(NH-A)-NH-A (IIIB). In formulae R5 = trivalent residue of 3-12C alkane. A = -CONH2. Z = -R1-, -R1-N(A)-R2- or -R1-N(A)-R2-N(A)-R3-(N(A)-R4-(with R1-R4 = 1-6C alkylene or hydroxyalkylene or 5-6C cycloalkylene). n = 1-6. Pref. (I) contains 1.0-20 wt.% (IIIA) or (IIIB) and (I) are obtd. by reaction of (IIIA) or (IIIB) with formaldehyde. (I) are amino resins (esp. UF or MFresins) contg. or based on (IIIA/B), (IIIA/B) are prepd. by reaction of corresp. polyamines with urea (as described, e.g. in US3390137), and the urea derivs. obtd. can then be reacted with formaldehyde at pH 8-12 to give amino resins. USE/ADVANTAGE - (I) are useful as binders for derived timber prods. Incorporation of even small amts. of (IIIA/B) gives binder solns. with markedly improved stability and the finished prods. (e.g. chipboard, plywood) have improved properties, esp. mechanical strength and low formaldehyde emission. (11pp Dwg.No.O/O)