Various semi-hard foams including highly elastic semi-hard, impact absorbing semi-hard, high load semi-hard foams and semi-hard foams that are close to hard foams with a big reactivity can be produced through reactions with a cross-linking agent and crude MDI. In mold forming, the forming is carried out at a relatively low temperature without external heating, and so the product is a suitable all-in-one mold forming of goods with synthetic resin as the outer surface, such as a PVC that is sensitive to heat. When using the product as an impact absorber and as an energy absorbing foam, such as car bumpers, the product can obtain an outstanding property of foam with good impact resistance.