| 摘要 |
<p>Aqueous melamine resin mixture comprises a resin in an amount of 50-70 wt.%, based on the aqueous melamine resin mixture. The molar ratio of melamine and formaldehyde in the resin amounts to 1:1.3-1:2. The resin comprises a component M (1-10 wt.%) comprising diethylene glycol (M1), polyethylene glycol (M2) with an average molecular weight of 200-1500, glycerol (M3) or optionally caprolactam (M4), based on the aqueous melamine resin mixture. Independent claims are also included for: (1) preparing an aqueous melamine resin mixture, comprising: (a) reacting melamine and formaldehyde in a molar ratio of 1:1.3-1:2, in an aqueous medium, with a portion of the component M (1-10 wt.%), based on the aqueous melamine resin mixture at a pH of 8-10 and at a temperature of 60-110[deg] C, (b) cooling the reaction mixture at a temperature of 10-50[deg] C and (c) adding the remaining portion of the component M to the cooled reaction mixture; (2) an impregnate obtained by treating an absorbent material with the aqueous melamine resin mixture and subsequently drying; (3) producing a composite material, comprising applying the impregnate to a carrier material under heat and pressure; and (4) the composite material obtained by the above method.</p> |
