METHOD OF PREPARING RIGID POLYURETHANE FOAM PLASTIC WITH OPENED CELLS Russian patent published in 1995 - IPC

FIELD: foam plastic materials. SUBSTANCE: polyol component containing a mixture of 57.5-75 wt. -% di- and/or trifunctional hydroxyl-containing simple polyethers with hydroxyl number 28-600 and 25-42.5 wt.-% bifunctional hydroxyl-containing phthalic acid polyether with hydroxyl number 150-440 is mixed with a mixture of polyphenylpolymethylene polyisocyanates and 70-80 wt. -% diphenylmethane diisocyanates, 12-30 wt.-% of which is 2, 2,4¹-diphenylmethane diisocyanate in the presence of water. Polyol component is able to install the catalyst on the basis of tertiary amine, glycerol and possibly silicone foam stabilizer. Mixing is carried out in apparatus of low pressure, and then article is formed. Density of foam plastic is 25-30 kg/m³, part of opened cells is 75-95 vol.%. EFFECT: improved method of foam plastic preparing. 2 cl