| 摘要 |
A composition which may be used to form a polyurethane foam of the type prepared by reacting (1) an organic polyisocyanate and (2) a polymeric compound containing free hydroxyl groups comprises (A) one of reactants (1) and (2), (B) a phosphorus acid and (C) a phosphorus compound being the formula <FORM:1056360/C3/1> wherein n is 0 or 1, m is 0, 1, 2 or 3 and Y is oxygen or sulphur, R is alkyl, a halogen substituted alkyl, an aralkyl, an alkaryl or an aryl group or the R groups together form a cyclic group. To form a polyurethane foam the composition is mixed with a blowing agent and whichever one of components (1) and (2) is not a component of the composition. Numerous phosphorus acids (B) are specified but in the examples those preferred are a mixture of monobutyl acid phosphate and dibutyl acid phosphate and a mixture of mono(2-ethylhexyl) acid phosphate and di(2-ethylhexyl) acid phosphate. Preferred neutral phosphorus compounds are tris(b -chloroethyl) phosphate, tricresyl phosphate, trimethyl thionophosphate, bis(chloropropyl) chloropropyl phosphonate and triethyl phosphite. The hydroxyl group containing polymer may be a polyester, polyether or mixtures thereof. Preferred polyesters are those derived from a hexahalocyclopentadiene/polycarboxylic acid adduct. Suitable polyethers are polypropylene glycol and those derived from trimethylolpropane and propylene oxide. A preferred polyisocyanate is a mixture and 2,4- and 2,6-toluene diisocyanates. Fluorocarbons boiling between 20 DEG C. and 50 DEG C. are the preferred blowing agents but tertiary alcohols in the presence of concentrated acids may also be used. Catalysts such as tertiary amines, antimony and tin compounds besides the phosphorus acids (B) which also act as catalysts for the polyurethane forming reaction may be used. Additional additives such as antimony trioxide, clay, calcium sulphate, ammonium phosphate, fibrous glass, asbestos and synthetic fibres may also be added to the compositions. |
