Polymer gel having sponge-like porous structure

A process for producing a polymer gel comprising:

• a) crosslinking solvophilic raw polymers under conditions of less than an overlapping concentration and less than a critical gelation concentration to form gel precursors, wherein the gel precursors have a relationship of G′<G″ between a storage modulus G′ and a loss modulus G″;
• b) crosslinking the gel precursors with each other using a crosslinking agent to obtain the polymer gel;
• and
• c) allowing the polymer gel to stand in water for at least 7 days;
• wherein the polymer gel has a three-dimensional structure including two regions:
• a first region in which polymer units derived from the solvophilic raw polymers are densely present and a second region in which polymer units derived from the solvophilic raw polymers are sparsely present and a mesh size composed of the first region is in the range of 1 to 500 μm.

A process for producing a polymer gel comprising

• a) crosslinking solvophilic raw polymers having a concentration of less than an overlapping concentration and equal to or more than a critical gelation concentration with each other in the presence of a non-reactive polymer having a predetermined concentration to obtain the polymer gel, and
• b) allowing the polymer gel to stand in water for at least 7 days;
• wherein the non-reactive polymer is a polymer having no functional group capable of crosslinking with the raw polymers in a molecule, and
• the polymer gel has a three-dimensional structure including two regions:
• a first region in which polymer units derived from the solvophilic raw polymers are densely present and a second region in which polymer units derived from the solvophilic raw polymers are sparsely present and a mesh size composed of the first region is in the range of 1 to 500 μm.