Reaktion #54176
ord-171ce8f88a4e48f2a4065c6917851432
Reaktionsgleichung
Reagenzien
Lösungsmittel
Reaktionsbedingungen
Vorschrift
A cationic poly(urethane-urea) lacquer was prepared as follows: 400 parts by weight of a 1000 molecular weight poly(1,4-butanediol adipate) was charged to a suitable reaction vessel along with 85.7 parts by weight of methyl diethanolamine, 0.44 parts by weight of dibutyltin dilaurate urethane-forming catalyst, 3.88 parts by weight of N-methyl pyrrolidone solvent and 419 parts by weight of HYLENE W. The reaction mixture was heated to 95° C. under a nitrogen atmosphere for a 41/2 hour period. The reaction mixture was then cooled to room temperature and the NCO-polymer which was formed was quaternized with 100.8 parts by weight of dimethyl sulfate. The quaternizing agent was added to the reaction mixture in a dropwise fashion. After quaternizing the NCO-containing polymer, it was thinned by combining it with 280 parts by weight of N-methyl pyrrolidone. The thinned NCO-containing polymer was dispersed and chain extended by charging it to a solution of 24 parts by weight of hydrazine hydrate dissolved in 1245 parts by weight of deionized water. The mixture dispersed very well, increasing in viscosity halfway through addition such that an additional 2500 parts by weight of water were added during the addition to reduce the viscosity. The final dispersion had a solids content of 19.8 percent, a pH of 6.75, a Brookfield viscosity at 23° C. (1000 rpm's) of 4200 centipoises. The resin was essentially free of NCO groups as determined by an infrared scan.