초록 ▼

An improved sizing is feasible by adding into a papermaking pulp slurry an aqueous dispersion prepared by mixing an aqueous solution of an ampholytic acrylamide polymer having both cationic and anionic groups with a liquid substituted succinic anhydride or with an anhydrous liquid mixture of a liqui

An improved sizing is feasible by adding into a papermaking pulp slurry an aqueous dispersion prepared by mixing an aqueous solution of an ampholytic acrylamide polymer having both cationic and anionic groups with a liquid substituted succinic anhydride or with an anhydrous liquid mixture of a liquid substituted succinic anhydride and an oil-in-water type surfactant. Such a paper sizing process is very useful for making plasterboard base paper of multilayered structure composed of at least one surface layer having a high hot water resistance and at least one back layer having a good adhesiveness to plaster slush.

대표청구항 ▼

A process for sizing paper comprising: (o) forming an aqueous solution of ampholytic acrylamide polymer having both a cationic group and an anionic group, (i) feeding into a mixer continuously and at a constant metered rate (a) said aqueous solution of an ampholytic acrylamide polymer defining a dis

A process for sizing paper comprising: (o) forming an aqueous solution of ampholytic acrylamide polymer having both a cationic group and an anionic group, (i) feeding into a mixer continuously and at a constant metered rate (a) said aqueous solution of an ampholytic acrylamide polymer defining a dispersing agent and having about 2-80 mol.% cationic and about 3-20 mol.% anionic groups, (b) a liquid substituted succinic anhydride; and (ii) adding said aqueous dispersion into a papermaking pulp slurry continuously and at a constant metered rate immediately after said dispersion is prepared in said mixer. A process for making plasterboard base paper sheets of multilayered structure comprising sheeting together at least one sized wet web and at least one unsized wet web said unsized wet web being formed from an unsized papermaking material and said sized wet web being formed from a sized papermaking material, wherein said sized papermaking material is prepared by; (o) forming an aqueous solution of ampholytic acrylamide polymer having both a cationic group and an anionic group, (i) feeding into a mixer continuously and at a constant metered rate (a) said aqueous solution of an ampholytic acrylamide polymer having about 2-80 mol.% cationic and about 3-20 mol.% anionic groups to form a dispersing agent, (b) a liquid substituted succinic anhydride and an oil-in-water type surfactant and, (ii) adding said aqueous dispersion into a papermaking pulp slurry continuously and at a constant metered rate immediately after said dispersion is prepared in said mixer.