PURPOSE: To prevent lowering of viscosity, and migration of a viscous layer to the objective surface by forming a viscous layer in such a manner that a emulsion type viscous agent being added with water-soluble polymer is applied, and then dried, on one surface of a base material consisting of a polystylene foam body.
CONSTITUTION: A base material comprises a polystylene foam body having closed cells and being in the range of 12.5g/l in density. As viscous agent, an emulsion type is employed so as to blend uniformly the soluble polymer. The additive rate of the water-soluble polymer to the viscous agent may usually be 0.1-20wt.%, and preferably, 0.1-10wt.%. As the addition rate of the water-soluble polymer exceeds than 20%, it tends to be lowered in its viscosity, and as the addition amount of the water-soluble polymer is less than 0.1%, the effect for preventing the migration to the objective of the viscous layer is lowered.
MAKINO REIJI
ITO KUNINORI
UNNO TETSUJI
