USE OF ORGANOPOLYSILOXANES IN THE MANUFACTURE OF PAPER-COVERED GYPSUM BOARD

摘要

An organopolysiloxane suitable for use in treating paper to be used in plaster boards. The organopolysiloxane is obtained by reacting a polysiloxanol of the formula IMAGE in which R1 is a methyl or a phenyl radical, at least 90% of the R1 radicals however being methyl radicals, and n=20 to 250, with a silane having the formula H2N-R3-Si(OR2)3 in which R2 is a lower alkyl radical with 1 to 4 carbon atoms, R3 is a bivalent alkyl radical with 1 to 6 carbon atoms or the -(CH2)xR4(CH2)y-NH2 radical, in which R4 is oxygen, sulfur or the -NH- or -NH-CH2CH2-NH- radical and x/=3, and y/=2, in such amounts that 1 SiOH group of the polysiloxanol corresponds to more than 1 and up to 3 OR2 groups of the silane. Method for preparation of paper and cardboard for use in plaster boards as well as plaster boards made by using the present invention are disclosed.