| 摘要 |
PROBLEM TO BE SOLVED: To obtain a rigid polyurethane foam good in adhesivity to facing materials, sufficiently exhibiting its water absorption resistance and storage stability, by reaction between a specific polyol component and an isocyanate component in the presence of water, a tertiary amine catalyst and a specific silicone-based foam stabilizer. SOLUTION: This rigid polyurethane foam is obtained by reaction between (A) a polyol component and (B) an isocyanate component in the presence of (C) water, (D) a tertiary amine catalyst and (E) a silicone-based foam stabilizer. The component A is a mixture composed of 10-40wt.% of a polyether polyol with tolylenediamine as initiator (hydroxyl number being 460±20), 20-50wt.% of a polyether polyol with ethylenediamine as initiator (hydroxyl number being 500±20), 15-25wt.% of a polyether polyol with glycerol as initiator (hydroxyl number being 34±5) and 10-25wt.% of dipropylene glycol (hydroxyl number being 840). The component E to be used is a polyoxyalkylene glycol- dimethylpolysiloxane block copolymer. |
