GB926413A - Improvements in or relating to the manufacture of foamed polyurethane materials - Google Patents

Abstract

A process for the manufacture of foamed polyurethane materials by the interaction of hydroxyl group-containing polymers such as polyesters, polyesteramides and polyethers, water and organic polyisocyanate compositions comprising a major proportion by weight of a diarylmethane diisocyanate and at least 5% by weight of a polyisocyanate having more than two isocyanate groups per molecule is characterized in that the interaction is carried out in the presence of a polysiloxane-polyoxyalkylene block copolymer. The block copolymer usually has a polysiloxane block of molecular weight 500 to 2,000 and a polyoxyalkylene block of molecular weight 500 to 5,000. It can be prepared, for example, by reacting polysiloxanes having terminal ethoxy groups with polyoxyalkylene compounds having terminal hydroxyl groups. The polyisocyanate having more than two isocyanate groups may be added directly to the polyisocyanate composition or may result from (1) reaction of some of the diarylmethane diisocyanate with a polyhydric alcohol; (2) partial polymerization of the diisocyanate to isocyanurate derivatives; or (3) production of the polyisocyanate by phosgenation of a crude amine mixture containing tri- and higher derivatives. Preferably the polyisocyanate composition contains carbamyl chloride in amount to give 0,01 to 3% of ionizable chlorine. As flame-proofing agents halogen compounds, organic and inorganic phosphates and borates and oxides of antimony, tin or zinc may be added. Suitable catalysts are N-methyl morpholine, N,N-dimethylbenzylamine, b -diethylaminoethanol, triethanolamine and triethylamine and their salts with, e.g. lactic or citric acid, iron acetyl acetonate and dibutyl tin dilaurate. In examples (1) a foamed product is prepared from a mixture of a polyester of pentaerythritol, 1:3-butylene glycol, adipic acid, and phthalic anhydride (acid value 6,8 m.g. KOH/gm., OH value 7,1 m.g. KOH/gm.); water; dimethylbenzylamine lactate; b -trichlorethyl phosphate; a dimethylsiloxane/ethylene oxide/propylene oxide block copolymer; and a diphenyl methane diisocyanate composition prepared from crude diaminodiphenyl methane containing 15% poly(mainly tri-) amines; (3) a triethanolamine/propylene oxide condensate is reacted similarly. The use of a dimethylsiloxane/ethylene oxide block copolymer is also exemplified. Specifications 842,154, 848,671, 874,430 and 924,111 are referred to.ALSO:A process for the manufacture of foamed polyurethanes by the interaction of hydroxyl group-containing polymers such as polyesters, polyesteramides and polyethers, water and organic polyisocyanate compositions comprising a major proportion by weight of a diaryl methane diisocyanate and at least 5% by weight of a polyisocyanate having more than two isocyanate groups per molecule is characterised in that the interaction is carried out in the presence of a polysiloxane polyoxyalkylene block copolymer. The block copolymer usually has a polysiloxane block of molecular weight 500 to 2000 and a polyoxyalkylene block of molecular weight 500 to 5000. It can be prepared, for example, by reacting polysiloxanes having terminal ethoxy groups with polyoxyalkylene compounds having terminal hydroxyl groups. The polyisocyanates having more than two isocyanate groups may be added directly to the polyisocyanate composition or may result from (1) reaction of some of the diarylmethane diisocyanate with a polyhydric alcohol; (2) partial polymerization of the diisocyanate to isocyanurate derivatives; or (3) production of the polyisocyanate by phosgenation of a crude amine mixture. Preferably the composition contains corbamyl chloride in amount to give 0,01% to 3% of ionisable chlorine. As flame-proofing agents there may be added halogen compounds, organic and inorganic phosphates and borates, and oxides of antimony, tin or zinc. Suitable catalysts methyl morpholine, dimethyl benzylamine, diethylaminoethanol, triethanolamine and triethylamine and their salts with e.g. lactic or citric acid, iron acetyl acetonate, and dibutyl tin dilaurate. In examples (1) a foamed product is prepared from a mixture of a polyester of pentaerythritol, 1 : 3- butylene glycol, adipic acid and phthalic anhydride (acid value 6,8 m.g. KOH and OH value 7,1 m.g. KOH (g.m.); water; dimethylbenzylamine lactate; trib - chlorethyl phosphate; a dimethyl siloxane/ethylene oxide/propylene oxide block copolymer; a diphenylmethane diisocyanate composition prepared from crude diaminodiphenyl methane containing 15% poly (mainly tri-) amines; (3) a triethanolamine/propylene oxide condensate is reacted similarly. Specifications 842,154, 848,671, 874,430 and 924,111 are referred to.