초록 ▼

Novel and improved paperboards useful for making gypsum wallboards, which are sized with a specific organopolysiloxane comprising mercaptoalkyl containing organosiloxane units and, optionally, methacryloxy-containing organosiloxane units in its molecular structure. The sizing compound is used in a r

Novel and improved paperboards useful for making gypsum wallboards, which are sized with a specific organopolysiloxane comprising mercaptoalkyl containing organosiloxane units and, optionally, methacryloxy-containing organosiloxane units in its molecular structure. The sizing compound is used in a relatively small amount and yet can exhibit an excellent effect within a very short time. The sized paperboards have adequately controllable moisture absorption as well as air permeability. They are used to cover or sandwitch a gypsum core to form a complete wallboard in a convenient and economical manner.

대표청구항 ▼

A paperboard for a gypsum wallboard which is sized at at least one of both surfaces with an organopolysiloxane comprising (a) from 99.95 to 85 mole % of organosiloxane units represented by the general formula R1aSiO(4-a)/2 where R1 is a hydrogen atom or a monovalent hydrocarbon group selected from t

A paperboard for a gypsum wallboard which is sized at at least one of both surfaces with an organopolysiloxane comprising (a) from 99.95 to 85 mole % of organosiloxane units represented by the general formula R1aSiO(4-a)/2 where R1 is a hydrogen atom or a monovalent hydrocarbon group selected from the class consisting of methyl, ethyl, propyl, vinyl, and phenyl groups and a is 1, 2, or 3, (b) from 0.05 to 10 mole % of mercapto-containing organosiloxane units represented by the general formula HS－CH2)pSiR2bO(3-b)/2 where R2 is a hydrogen atom or a monovalent hydrocarbon group selected from the class consisting of methyl, ethyl, propyl, and phenyl groups, b is 0, 1, or 2 and p is 1, 2, 3, or 4, and (c) from 0 to 5 mole % of methacryloxy-containing organosiloxane units represented by the general formula H2C〓C(CH3)－CO－O－CH2)qSiR3cO(3-c)/2 where R3 is a hydrogen atom or a monovalent hydrocarbon group selected from the class consisting of methyl, ethyl, propyl, and phenyl groups, c is 0, 1, or 2 and q is 1, 2, 3 or 4, and wherein the amount of sizing is in the range from 15 g to 200 g of the organopolysiloxane per 1,000 kg of the paperboard on either one of the surfaces.