GB1376531A - Polyurethane froth - Google Patents

Abstract

1376531 Coated products TEXTILE RUBBER & CHEMICAL CO 1 Feb 1972 [3 Nov 1971] 4666/72 Heading B2E [Also in Division C3] Carpets may be backed with a heat-curable flexible polyurethane-forming froth mixture which comprises a transformed diphenylmethane diisocyanate obtained by heating a diphenylmethane diisocyanate with from 0.1% to 3% by weight of a trihydrocarbyl phosphate wherein the hydrocarbyl radical contains from 1 to 12 carbon atoms, at a temperature of 160‹C to 250‹C, a polymeric hydroxy compound, a silicone surfactant, a catalyst selected from nickel acetylacetonate, diacetonitrilediacetylacetonato nickel, diphenylnitrilediacetylacetonato nickel and bis (triphenylphosphine)-diacetylacetonato nickel and an inert gas uniformly dispersed throughout the mixture. The froth is most suitably cured to a tack-free foam condition by raising the temperature thereof to at least 70‹C. In an Example the diisocyanate is prepared by heating diphenylmethane diisocyanate with triethyl phosphate. Polyethers, polyesters and lactone polyesters are the preferred polymeric hydroxy compounds. The inert gas is most preferably air but may be nitrogen or carbon dioxide, and may be incorporated into the mixture by mechanical beating or under pressure. Most preferably the froth is applied to the undersurface of a previously tufted primary backing material. The first backing may be any conventional carpet backing material e.g. jute or polypropylene.