| 摘要 |
PROBLEM TO BE SOLVED: To provide a core for corrugated board that has sufficient compression strength and is excellent in laminating with a liner regardless of a low basis weight and a weight reduction.SOLUTION: The core for corrugated board includes base paper for core obtained by making paper from raw material pulp and is obtained by coating on at least one side of the base paper with a coating liquid including a paper-strengthening agent as a main component. The paper-strengthening agent includes hyperbranched polyacrylamide as a main component, and the core for corrugated board has a basis weight of 130 g/mor less, a compression strength (lateral) of 184 N or more, and a gas permeation resistance of 55 seconds or less. It is preferable that the hyperbranched polyacrylamide has a solid concentration of 12.5 mass%, and the aqueous solution has a viscosity of 9 mPa s or more and 25 mPa s or less at a temperature of 30°C. Also, it is preferable that the coating amount of the hyperbranched polyacrylamide is 0.5 g/mor more and 2.5 g/mor less per single surface of the core for corrugated board in terms of solid content. |
