Patent ID: 11111353

Abstract:
A method for producing a porous material includes processing a urethane resin composition containing a urethane resin (A) and a solvent (B) by a wet film forming process, in which the solvent (B) satisfies the following conditions: a difference between a Hansen solubility parameter of the solvent (B) (B-HSP) and a Hansen solubility parameter of the urethane resin (A) (A-HSP) is in the range of 3 to 8 (J/cm3)1/2 and a difference between the Hansen solubility parameter of the solvent (B) (B-HSP) and a Hansen solubility parameter of water (W-HSP) is in the range of 31.5 to 38 (J/cm3)1/2. The Hansen solubility parameter of the solvent (B) preferably has a dispersion term (δD) in the range of 15.5 to 21.0 MPa0.5, a polar term (δP) in the range of 7.0 to 14.5 MPa0.5, and a hydrogen bond term (δH) in the range of 4.5 to 11.0 MPa0.5.