MODIFIED MELAMINE RESINS AND THEIR APPLICATION FOR PRODUCTION OF LAMINATES SUITABLE FOR SUBSEQUENT MOULDING

摘要

PCT No. PCT/EP97/03321 Sec. 371 Date Jan. 12, 1999 Sec. 102(e) Date Jan. 12, 1999 PCT Filed Jun. 25, 1997 PCT Pub. No. WO98/02474 PCT Pub. Date Jan. 22, 1998Modified melamine-formaldehyde resins are made of a condensate of formaldehyde, urea, melamine and modifying agents which contains: (a) a combination of 5 to 25 wt %, with respect to melamine, of dicyanodiamide and 8 to 30 wt %, with respect to melamine, of water-soluble polyalcohol with at least two hydroxyalkyl groups, and/or (b) 1.5 to 20 wt % amines having the formulas (Ia)NR4R5-R1-X(Ia)and/or (Ib),NR4R5-R2-Y-R3-X(Ib)in which R1 and R3 are the same or different and depending on the meaning of X stand for a linear, branched or cyclic C1-C12 alkyl or alkylene radical and R2 stands for a linear, branched or cyclic C1-C12 alkylene radical; R4 and R5 can be the same or different and can stand for H or for a linear or branched C1-C12 alkyl radical; and X can stand for hydrogen, OH or NR4R5 and Y can stand for -O- or -NH-. The molar ratio of melamine to formaldehyde ranges from 1:1.2 to 1:5 and the molar ratio of melamine to urea ranges from 1:0.1 to 1:2.8. Also disclosed is the use of these resins to produce post-forming laminates.