The viscosity is a value determined by using a 1% by weight aqueous solution at 20??? C. C. Gel Strength [0081] Two sheets of mesh sheets having a size of 1 cm (width)???2 cm (length) commercially available from ADVANTEC under the trade name of MESH SHEETS (76 mm) were placed at a distance of about 1 mm on a fluorocarbon resin plate having a size of 1 cm???1 cm.