| 摘要 |
A backing sheet for the weathering-resistant coating of thin, plane backings in continuous presses without recooling comprising (A) a paper impregnated with curable melamine resin in an amount of 40 to 60 weight percent of aminoplast resin, based on the weight of the paper, in the dried state, and (B) a coating of curable acrylic resin on the impregnated paper in an amount of 60 to 150 g/m2, the curable acrylic resin being a copolymer obtained by polymerizing: (a) 60 to 80 weight percent of one or more alkyl methacrylate esters with 1 to 20 carbon atoms in the alkyl radical; (b) 1 to 30 weight percent of one or more alkyl acrylate esters with 1 to 8 carbon atoms in the alkyl radical; (c) 1 to 20 weight percent of an N-methoxymethylamide of acrylic acid, methacrylic acid, or mixtures thereof; (d) 1 to 20 weight percent of a hydroxyalkyl ester of acrylic or methacrylic acid, with 2 to 4 carbon atoms in the alkyl radical; (e) 1 to 20 weight percent of acrylamide or methacrylamide, the molar ratio of component (c) to the sum of (d) and (e) being about 1:1 and the ratio of (d) to (c) being 4:1 to 1:4; (f) 0 to 35 weight percent of acrylonitrile, the sum of components (a) to (f) being 100 weight percent. The so-called endless laminates, fabricated by using the inventive backing sheet containing the selected acrylic resin, have a defect-free surface, even though the laminates were not recooled.
|
