| 摘要 |
PROBLEM TO BE SOLVED: To provide a holding pad capable of stably holding a workpiece for a long period of time.SOLUTION: The holding pad 10 includes an expandable sheet 2 formed of polyurethane resin having a foaming structure in which a plurality of foams 3 and a large number of micropores 6 are continuously formed by a wet film deposition method. Sizes of the large number of micropores 6 are formed smaller than sizes of the foams 3. In the foaming structure formed in the expandable sheet 2, acid-resistant or alkali-resistant resins 5 are present in the large number of micropores 6 at amounts that the proportion of the volume of the acid-resistant or alkali-resistant resins 5 relative to the volume of the micropores 6 becomes ≥30%. The acid-resistant or alkali-resistant resins 5 are formed by impregnating a resin emulsion in the expandable sheet 2. The foaming structure of the expandable sheet 2 is reinforced by the acid-resistant or alkali-resistant resins 5, and surfaces of the micropores 6 are protected thereby. |
