| abstract |
Provided is a novel bonding agent. A bonding agent that has an average degree of saponification of 85.0–89.0 mol% as measured in accordance with JIS K6726 and is formed from a polyvinyl alcohol polymer that satisfies condition (A) and/or condition (B). Condition (A): The transparency, at 20̊C, of a liquid that results from adding 130.0 mL of 1-propanol to 100.0 g of a 5.0 mass% aqueous solution of the polyvinyl alcohol polymer is no more than 80.0%. Condition (B): the supernatant concentration, at 20̊C, of a liquid that results from adding 230.0 mL of 1-propanol to 100.0 g of a 5.0 mass% aqueous solution of the polyvinyl alcohol polymer is at least 0.65 mass%. |