PURPOSE: To strengthen the adhesion of the cover layer to the core by positioning the polyurethane core so that the gap against the inner wall of a mold is 0.5 mm and filling a reaction mixture consisting of a polyisocyanate component and a polyol component into the gap.
CONSTITUTION: The surface of the polyuyethane core A is positioned so as to make the average gap against the inner wall of a mold to be 0.5 mm. A polyurethane cover B is placed in the gap to cover the core A. The polyurethane cover B is constituted as a reaction mixture of a polyisocyanate component with 5-50% of isocyanate content, a polyol component consisting of 30 wt.% of polyhydroxyl compound which has 50-800 of average hydroxyl value and 3:1 of carbon:oxygen weight ratio, and an additive. The polyurethane cover B is strongly adhered to the core material A by the constitution to make releasing from a mold easier.
URURITSUHI KUNITSUPU
PEETERU SHIYUSUTERU
MAACHIN BUROTSUKU
RONARUTO BOOTO
