| abstract |
The disclosure is directed to a method of using melamine resin fibers, to an insulating material comprising (a) from 5 to 95% by weight of melamine resin, and (b) from 5 to 95% by weight of polyalkylene terephthalate fibers, and to processes for producing it. A method of using modified melamine resin fibers obtainable by condensational mixture comprising (A) from 90 to 99.9 mol% of a mixture comprising (a) from 30 to 99.9 mol% of melamine and (b) from 1.0 to 70 mol% of a substituted melamine of the general formula I where X1, X2 and X3 are each selected from -NH2, -NHR1 and -NR1R2, subject to the proviso that X1, X2 and X3 are not all -NH2, and R1 and R2 are independently selected from hydroxy-C2-C20-alkyl, hydroxy-C2-C4-alkyl-(oxa-C2-C4-alkyl)n, where n is from 1 to 5, and amino-C2-C12-alkyl, or mixtures of melamines of formula I, and (B) from 0.1 to 10 mol%, based on (A) and (B), of a compound selected from phenols which are unsubstituted or substituted by radicals selected from C1-C9-alkyl and hydroxyl, C1-C4-alkanes substituted by two or three phenol groups, di(hydroxyphenyl) suit ones and mixtures thereof, with formaldehyde or formaldehyde-supplying compounds in a molar ratio of melamines to formaldehyde within the range from 1:1.15 to 1:4.5, as and in thermal and/or acoustic insulating material. |