| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing syrup excellent in colorless transparency and suppressed of cost.SOLUTION: There is disclosed a production method of syrup by polymerizing a vinyl monomer using a thermally degradable radical polymerization initiator including a process, where primary mercaptan containing only one SH group and containing no -OH group nor -COOH group in the molecule is added in a vinyl monomer after adding the radical polymerization initiator to the vinyl monomer in an amount Y (part mass) of 0.008 pt.mass or more and satisfying a formula: Y≤-1.7I+0.13 (wherein, I represents a part mass of the radical polymerization initiator remaining at the time of adding the primary mercaptan). However, each the part mass represents a part mass based on 100 pts.mass of the vinyl monomer before polymerization. |
