| abstract |
Use of an organopolysiloxane having the formula <IMAGE> in which R1 is an alkyl or aryl radical, at least 80% of the R1 radicals being alkyl radicals, R2 is an alkyl radical or the R4Z radical, at least 2/3 of the R2 radicals being R4Z radicals, in which R4 is a difunctional hydrocarbon radical, Z is -NH2, -NH(CH2)c-NH2, -NH(CH2)cNH(CH2)cNH2, in which c is 2, 3, -NHCONH2 radical, -SH, -S4-R4-Si(OR3)3, -P(C6H5)2 or <IMAGE> R3 is an alkyl radical with 1 to 4 carbon atoms, or a hydrogen radical, a is not less than 4, b/a is not less than 0.001, but not greater than 0.5, and x is not less than 0.1, but not greater than 2, as a material for decreasing the water absorption of paper which is intended to be used for coating plaster paste in the manufacture of paper-laminated plaster boards. The organosilicon compounds cure without the use of special catalysts. Their aqueous preparations exhibit high stability at use concentrations and are independent of the pH of the paper. The water absorption of papers which are free of aluminum sulfate can also be reduced. |