| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a high quality cardboard with high productivity, by adding a papermaking additive under cardboard manufacturing conditions at pH 6.5 to 8.5. <P>SOLUTION: A manufacturing method of a cardboard comprises a step of adding a papermaking additive, which is a methacrylamide copolymer produced by copolymerizing 1 to 20 mol% of a cationic vinyl monomer (C) capable of constituting a structure represented by a general formula (A), 0.01 to 5 mol% of methallyl sulfonate (D), and when required, a monomer of glycolic acids or a monomer of glyoxylic acids (B), to a pulp slurry at pH 6.5 to 8.5, so as to achieve a yield improvement rate (Re) of 3% or more under a specific condition. General Formula (A) (wherein R<SP POS="POST">1</SP>represents H or CH<SB POS="POST">3</SB>). <P>COPYRIGHT: (C)2012,JPO&INPIT |
