Production process for glyoxylic acid (salt)-based polymer

A production process for a terminal-end-stabilized glyoxylic acid (salt)-based polymer, which comprises the steps of:

• (i) anionically polymerizing a monomer component including a glyoxylic acid ester in the presence of an anionic-polymerization initiator in an anionic-polymerization to obtain a terminal-end-unstabilized glyoxylic acid (salt)-based polymer having terminal ends, wherein a terminal end stabilizer is used as a reaction medium of the anionic-polymerization, and wherein the terminal end stabilizer is an alkylene oxide, wherein the anionic-polymerization is carried out in the presence of a basic polymerization catalyst, then
• (ii) adding a terminal-end-stabilizing catalyst to react the terminal end stabilizer with the terminal ends of the terminal-end-unstabilized glyoxylic acid (salt)-based polymer to obtain a terminal-end-stabilized glyoxylic acid (salt)-based polymer, wherein the terminal-end stabilizing catalyst is an acid catalyst.