SE7408495L

1434445 Polyisocyanate solutions BAYER AG 24 June 1974 [27 June 1973 26 March 1974] 27852/74 Heading C3R A process for the preparation of a physiologically harmless solution of a polyisocyanate which solution generally contains less than 0À7% wt. of free diisocyanate and generally has an isocyanate content of over 0À5% wt., based on the solids content, comprises reacting a polyhydroxyl compound of the formula where R represents an n-valent aliphatic hydrocarbon group, preferably containing 2-14 carbon atoms, or an n-valent cycloaliphatic hydrocarbon group preferably containing 5-15 carbon atoms, and n = 2 or 3 with excess 1- isocyanato - 3,3,5 - trimethyl - 5 - isocyanatomethyl cyclohexane, (IPDI), generally at 40-160‹ C., preferably using an NCO/OH ratio of 3 : 1 to 20 : 1, and subsequently removing the excess unreacted IPDI in a 2-stage operation the first stage comprising the removal of the major proportion of the unreacted IPDI by distillation, and the second stage comprising dissolving the distillation residue which generally still contains 1-5% wt. of free IPDI in a lacquer solvent generally in 0À1-20 times its weight of lacquer solvent, and reacting the resulting solution, preferably at 0-120‹ C., with an alcohol of the formula preferably in a 0À1-10 times molar quantity, based on the free IPDI still present, in which R1 represents an aliphatic hydrocarbon radical preferably containing 1-18 carbon atoms, a dialkylaminoalkyl radical preferably containing a total of 4-18 carbon atoms, or an aliphatic hydrocarbon radical, preferably containing a total of 4-18 carbon atoms which contains either oxygen bridges and which may also contain a tertiary amino end group. The resulting products can be used in the production of 2-component polyurethane lacquers and as cross-linking agents for air drying alkyd resins. In Examples 1 and 3 IPDI is reacted with trimethylolpropane and the reaction product subjected to a thin layer distillation. The residue is dissolved in xylene/ethylene glycol acetate and reacted with lauryl alcohol. The resulting product is used to cross-link a medium oily alkyd resin modified with dry vegetable fatty acids. In Example 5 IPDI is reacted with a mixture of butane 1,3 diol and trimethylol propane, then subjected to thin layer distillation then dissolved in xylene/ethylene glycol acetate and reacted with either diethylethanolamine, lauryl alcohol or isopropanol. The resulting products are added to an air-drying alkyd resin lacquer compr