Patent ID: 6528609
Filing Date: 2003-03-04
Classification: C08G

Abstract:
A process for the preparation of a storage stable allophanate-modified polymethylene poly(phenyl isocyanate) comprising:(A) reacting: (1) an intermediate comprising the reaction product of: (a) polymethylene poly(phenyl isocyanate) having an NCO group content of 20 to 33%, and having a monomer content of 26 to 95% by weight, and comprising: (i) from 0 to 5% by weight of the 2,2â€²-isomer of MDI; (ii) from 1 to 25% by weight of the 2,4â€²-isomer of MDI; and (iii) from 25 to 65% by weight of the 4,4â€²-isomer of MDI; and (iv) from 5 to 74% by weight of higher molecular weight homologues of the MDI series; â€ƒwith the %'s by weight of (1)(a)(i)-(1)(a)(iv) totaling 100% by weight of component (1)(a); (b) at least one epoxide; and (c) at least one alcohol; â€ƒwherein said reaction was carried out at a temperature of from about 25 to about 90Â° C. and for a time of about 5 minutes to about 1 hour; with (2) at least one allophanate catalyst; â€ƒat a temperature of from about 60 to about 120Â° C. for about 15 minutes to about 4 hours.