| 摘要 |
<p>A paper improver for use in papermaking which, even when a pulp feedstock is formed into a sheet under high-speed conditions, enables the sheet to be improved in bulkiness, whiteness, opacity, and paper strength. The paper improver comprises, in a specific proportion by weight, (A) a copolymer comprising structural units derived from one or more nonionic monomers having a solubility parameter of 20.5 (MPa)<1/2> or smaller and structural units derived from one or more anionic or cationic monomers and (B) a surfactant. It produces at least one of the following paper quality-improving effects: (i) the degree of improvement in standard bulkiness is 0.02 g/cm<3> or higher, (ii) the degree of improvement in standard opacity is 1.0 point or higher, and (iii) the degree of improvement in standard whiteness is 0.5 points or higher.</p> |
