| 摘要 |
PROBLEM TO BE SOLVED: To provide an MC class middle core base paper prescribed in JIS P3904:2011 satisfying the standards of ISO compressive strength (in a horizontal part) and tensile strength (in a vertical part) prescribed in JIS P3904:2011 by reducing the bad influence of a pitch component derived from used paper.SOLUTION: In the making of an MC class middle core base paper, without adding a sulfuric acid band and a paper power agent, only a cationic yield agent is internally added, and paper making is performed. The addition rate of the solid content to the paper stock of the cationic yield agent is controlled to 50 to 300 ppm, the cationic yield agent being an acrylamide based yield agent. |
