Binder and bonded object

Abstract

Provided is a binder including a polymer having a hydroxyl group, wherein the polymer includes a structural unit derived from an unsaturated carboxylic acid-based monomer, and a structural unit derived from at least one hydroxyl group-containing monomer selected from the group consisting of 2-hydroxyethyl acrylate, allyl alcohol, and isoprenol, the content of the structural unit derived from the hydroxyl group-containing monomer is 5 mol % to 50 mol % based on the total amount of the polymer, the weight average molecular weight of the polymer is 1000 to 5000, and the pH is 6.5 or lower.

Dependencies are inferred from the claim text.