Production process for water-absorbing agent

A production process for a water-absorbing agent, comprising the steps of mixing a water-absorbent particulate resin with a crosslinking agent and heating the resultant mixture, wherein the water-absorbent particulate resin has a carboxyl group;

• with the process being characterized in that the crosslinking agent has an average molecular weight of 500 or more and is shown by general formula (2) below:
• X—(CH2CH2O)m—CH2—CH(OH)—CH2—O)n—CH2CH2O)m−1—(CH2CH2)—Y (2)
• wherein:
• m is an integer of 1 to 10;
• X and Y are units that include a functional group reactable upon a carhoxyl group, wherein X and Y may be either the same as or different from each other;
• wherein each of X and Y is an RO group, wherein R is a glycidyl group, its hydrolysate, or a hydrogen atom;
• and
• n is an integer of 3 or more.

A production process for a water-absorbing agent, comprising the steps of mixing a water-absorbent particulate resin with a surface-crosslinking agent and heating the resultant mixture, wherein the water-absorbent particulate resin has a carboxyl group, and wherein the surface-crosslinking agent includes at least two epoxy groups or at least two hydroxyl groups;

• with the process being characterize in that the surface-crosslinking agent has no cationic group and in that the resultant water-absorbing agent displays a crosslinking absorption property index of 1,000×10, or more, wherein 1he index is defined by the following equation:
• crosslinking absorption property index=A×B×C
• wherein:
• A is an average molecular weight of the surface-crosslinking agent for the water-absorbent particulate resin;
• B is an Absorption capacity (g/g) under no load of the resultant water-absorbent agent;
• C is an absorption capacity (g/g) under a heavy load of the resultant water- absorbing agent.