Patent ID: 7972551

Claim:
A method for producing a solid body having depressed portions on its surface, comprising: using a solution which comprises a solvent A, a solvent B, a solvent C, and a polymer compound, where the solvent B is a hydrophobic solvent, the solvent A is a hydrophilic solvent having a boiling point not lower than the boiling point of the solvent B, and the solvent C is a non-hydrophobic solvent having a boiling point lower than the boiling point of the solvent B, and the contents of the solvent A, solvent B, and solvent C satisfy the following conditions (1) to (5); and solidifying the solution while forming depressed portions on the surface of the solution by condensation during the process of evaporating the solvents included in the solution: (1) the content of the solvent A is 0.1 mass % or more and less than 25.0 mass % based on the total mass of all the solvents included in the solution, (2) the content of the solvent B is larger than the content of the solvent A, (3) the content of the solvent B is 5.0 mass % or more and 49.9 mass % or less based on the total mass of all the solvents included in the solution, (4) the content of the solvent C is 50.0 mass % or more and 94.9 mass % or less based on the total mass of all the solvents included in the solution, and (5) the total content of the solvent A, solvent B, and solvent C is 90.0 mass % or more based on the total mass of all the solvents included in the solution.