FIELD: chemistry.
SUBSTANCE: invention relates to a composition reacting with isocyanate, to a reaction system for producing rigid polyurethane foam, to rigid foamed polyurethane. Composition contains a reactive component and a hydrocarbon physical frothing agent. Reactive component includes the following components: (a) from 5 wt. % to 30 wt. % of at least one novolac type polyoxypropylene polyether polyol having a nominal number of hydroxyl functional groups of 2 to 5 and a hydroxyl number of 130 to 450 mg KOH/g, (b) from 20 wt. % to 60 wt. % of at least one high-functional polyether polyol having a nominal number of hydroxyl functional groups of 6 to 8 and a hydroxyl number of 300 to 700 mg KOH/g, (c) from 2 wt. % to 30 wt. % of at least one low-functional polyether polyol having a nominal number of hydroxyl functional groups of 2 to 5 and a hydroxyl number of 50 to 400 mg KOH/g, (d) from 2 wt. % to 30 wt. % of at least one amine-initiated polyol, which is an aromatic amine-initiated polyol, having a hydroxyl number of 250 to 600 mg KOH/g, (e) from 1 wt. % to 25 wt. % of catalyst mixture, chemical foaming agent and surfactant. Hydrocarbon physical frothing agent is present in amount of at least 10 wt. parts and less than 20 wt. parts with respect to 100 wt. parts of reactive component. Reaction system for producing rigid polyurethane foam contains said composition and an isocyanate component and has an isocyanate index of 100 to 300. Rigid foamed polyurethane is obtained using said reaction system. Rigid foamed polyurethane has expansion after extraction from mold in 4 minutes equal to 4.4 mm.
EFFECT: invention enables to obtain a composition which is stable during storage and does not exhibit phase separation, which is determined through normal visual observation for a period of at least 7 days in room conditions, and also considerably improves foam expansion after removing foam from the mold.
7 cl, 3 tbl, 9 ex
