Edetate Sodium → Dimethyl acetylenedicarboxylate

Temperature

72 °C

For comparison purposes, a terpolymer outside the scope of applicants' invention was prepared and tested. Into a 1 liter resin reaction flask fitted with a stirrer, thermometer, condenser, nitrogen inlet and a port for adding liquid, is placed 470.1 g of deionized water, 75.2 g of a 50% solution of acrylamide, 350 g of a 50% solution of AMPS, 37.6 g of N, N-dimethylacrylamide and 0.1 g of Versene 100. The solution is stirred and to it added a solution of 0.5 g of sodium hypophosphite dissolved in 16 g of deionized water. The solution is sparged sub-surface with nitrogen and then heated to 72° C. with an external heating jacket. A solution of 0.4 g of ammonium persulfate dissolved in 50 g of deionized water is prepared and placed in a metering pump connected to the flask at the inlet part with a fine bore tygon tubing. The persulfate solution is added uniformly to the flask over a period of three hours, maintaining a temperature of 72 ° C.±2° C. in the reactor by initially cooling and then warming. After the persulfate solution is added, the 72° C. temperature is maintained for an additional hour, then the solution is cooled to about 40 C and discharged. The resulting product was a clear, very pale yellow, viscous liquid with a solids content of 25%. The viscosity, as measured on a Brookfield viscometer, was 21,300 cps, spindle 4, speed 12. The pH of the solution was 3.0.

1. customFor comparison purposes, a terpolymer outside the scope of applicants' invention was prepared
2. customfitted with a stirrer
3. additionthermometer, condenser, nitrogen inlet and a port for adding liquid
4. customThe solution is sparged sub-surface with nitrogen
5. dissolutionA solution of 0.4 g of ammonium persulfate dissolved in 50 g of deionized water
6. customis prepared
7. temperaturemaintaining a temperature of 72 ° C.±2° C. in the reactor
8. temperatureby initially cooling
9. temperaturewarming
10. temperaturethe 72° C. temperature is maintained for an additional hour
11. temperaturethe solution is cooled to about 40 C

ORD record

ord-c60bfd01d1d64c86925c4f6c59d8178a

Source dataset

uspto-grants-1988_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04741843