Patent GB-1075039-A (GB)
Title: Manufacture of isocyan ate reaction products
Inventor: GUEST DOROTHY JOYCE
IPC: C08G18/80
Filed: 1965-06-24
Abstract: Isocyanate reaction products containing thermally labile urethane groups are obtained by reacting together a mixture of an organic diisocyanate, at least one aliphatic compound containing at least two hydroxyl groups, and a phenol, the said mixture containing approximately one aliphatic hydroxyl group and from 2 to 10 phenolic hydroxyl groups for each molecule of diisocyanate present.  The reaction is generally effected at 100-200 DEG  C. and the excess of phenolic reactant may serve as a solvent, or an inert solvent, e.g. an ester or ketone, may be added.  The number of labile urethane groups in the product may be controlled by regulating the quantities of the aliphatic and phenolic hydroxy-containing reactants and by varying the times and order of their addition.  It is preferred that the diisocyanate, the aliphatic hydroxyl compound or mixture of compounds, and the whole of the phenol component are reacted at approximately 140 DEG  C. followed by a further period of heating at 160 DEG  C., or that the diisocyanate, the aliphatic hydroxyl compound or mixture of compounds and from at least 1 mol of the phenolic compound per mol of diisocyanate to 50% by weight, taken from the total quantity of phenolic reactant, are reacted at approximately 140 DEG  C., and when the reaction is substantially complete, adding the remainder of the phenolic reactant and blending until a homogeneous solution is obtained.  The labile urethane groups in the product may be broken down at temperatures of 125-200 DEG  C. and blended with a branched polyester resin, e.g. one obtained by condensation of a mixture of dihydric and/or polyhydric alcohols and a dicarboxylic acid.ALSO:Isocyanate reaction products containing thermally labile urethane groups are obtained by reacting together a mixture of an organic diisocyanate, at least one aliphatic compound containing at least two hydroxyl groups, and a phenol, the said mixture containing approximately one aliphatic hydroxyl group and from 2 to 10 phenolic hydroxyl groups for each molecule of diisocyanate present.  The reaction is generally effected at 100-200 DEG  C. and the excess of phenol reactant may serve as a solvent, or an inert solvent, e.g. an ester or ketone, may be added.  The number of labile urethane groups in the product may be controlled by regulating the quantities of the aliphatic and phenolic hydroxy-containing reactants and by varying the times and order of their addition. It is preferred that the diisocyanate, the aliphatic hydroxyl compound or mixture of compounds and the whole of the phenol component are reacted at approximately 140 DEG  C. followed by a further period of heating at 160 DEG  C., or that the diisocyanate, the aliphatic hydroxyl compound or mixture of compounds and from at least 1 mol. of the phenolic compound per mol. of diisocyanate to 50% by wt., taken from the total quantity of phenolic reactant, are reacted at approximately 140 DEG  C., and when the reaction is substantially complete, adding the remainder of the phenolic reactant and blending until a homogeneous solution is obtained.