Novel resins and foams

摘要

1,137,263. Polyurethane foams. STANDARD OIL CO. 22 Dec., 1965 [23 Dec., 1964 (2)], No. 54337/65. Headings C3C and C3R. A foamed polyurethane is the reaction product of (i) a carboxylic compound having at least two carboxyl and/or carboxylic anhydride and/or acyl halide groups attached to one or more benzene nuclei, (ii) a polyisocyanate having at least two interconnected benzene nuclei and at least one isocyanate group per benzene nucleus, and (iii) a polyol of molecular weight below 2000 and having at least 3 OH groups per molecule. Component (i) may be, e.g. a trimellitic, pyromellitic, phthalic, isophthalic, trimesic, 3:4:31:41-tetracarboxybenzophenone, 3:4:31-tricarboxybenzophenone, or 4:41-dicarboxybenzophenone acid or derivative. Trimellitic anhydride or anhydride chloride is preferred. Component (ii) may be, e.g. isocyanatobenzene groups linked by ether, sulphone, sulphoxide, methylene, propylene, carbonyl or direct linkages. Component (iii) may be, e.g. a polyoxypropylenated pentaerythritol of M.W. 400, or a polyoxypropylenated glycerol, trimethylolpropane, 1:2:6-hexane triol, sorbitol, sucrose,α-methyl glycoside, ethylene diamine or diethylene triamine or a polyester polyol. The components may be mixed approximately simultaneously in a ratio of 0À5-1À5 carboxylic groups of (i) per isocyanate group of (ii), and 0À25-0À75 hydroxyl groups of (iii) per group of (i) and (ii) combined. Alternatively (i) and (ii) may be premixed to give a liquid foam precursor containing 1-4 carboxylic groups per isocyanate group, the polyol being added subsequently. No external heat supply is required for these steps. Conventional fluoro-alkane blowing agents, silicone foam stabilizers and tertiary amine and organo-tin catalysts may be added. In Examples trimellitic acid, anhydride, acid chloride, anhydride chloride, double anhydride, or acid/anhydride mixture, or pyromellitic anhydride, or terephthalic, trimesic or isophthalic acid is mixed with a trifunctional polymethylene polyphenylisocyanate and to this mixture is added a polyether polyol mixture containing sucrose, phosphorus-containing and amine residues, or a polyoxypropylenated pentaerythritol of M.W. 400, together with CClF 3 and optionally a tertiary amine catalyst, dibutyltin diacetate (or laurate) cobalt naphthenate and/or a silicone oil.