Hydrochloric Acid → Potassium Persulfate

Temperature

90 °C

About 1160 ml of water was heated in a reactor to 90° C. A solution of 1.39 g potassium persulfate initiator in 160 ml water was prepared. An initial 32 ml of this initiator solution was added to the reactor bath and stirred. Separately, a first monomer emulsion comprising 77.56 g styrene, 278.84 g hexyl methacrylate, 3.6 g ethylene glycol dimethacrylate, 1.44 g isooctylthio glycolate chain transfer agent, and 29.95 g of 30% Rhodafac RS 710 was prepared in 122.4 ml water. A second monomer emulsion comprising 6 g styrene, 21.6 g hexyl methacrylate, 12 g p-styrenesulfonyl chloride (blocked acid monomer of Example 2), 0.4 g ethylene glycol dimethacrylate, 0.16 g isooctylthio glycolate, and 3.33 g of 30% Rhodafac RS 710 was separately prepared in 13.6 g of water. The first monomer emulsion was added dropwise to the reaction vessel over a 30 minute period and stirred. Simultaneously, 110 g of the initiator solution was added dropwise to the reaction vessel over the same period. Fifteen minutes following completion of the first monomer emulsion and initiator feeds, the second monomer emulsion was added dropwise to the reaction bath over a period of 5 minutes. The remaining 18 g of initiator solution was added dropwise to the reaction bath over the same 5 minute period. The reaction was stirred and maintained at 90° C. for an additional 1.5 hours. About 0.3 g. t-butyl peroxide was then added to the reactor with continued heating for 15 minutes. The reaction was then allowed to cool to 50° C. Potassium hydroxide (50% in water) was added to bring the formed latex solution to a pH of 9.2. The solution was then stirred at 90° C. for an additional 1.5 hours during which the pH dropped to 6.8 (due to release of HCl resulting from the unblocking). The contents were cooled to ambient temperature, after which additional potassium hydroxide was added to adjust the pH to 8.5 and to salt the surface acid groups. The latex solution was subsequently filtered with a 200 mesh filter to obtain 20.0% solids latex solution having a particle size of 150 nm. The amount of acid in this latex was 14.8 millimoles.

1. additionThe first monomer emulsion was added dropwise to the reaction vessel over a 30 minute period
2. stirringstirred
3. customFifteen minutes
4. additionthe second monomer emulsion was added dropwise to the reaction bath over a period of 5 minutes
5. stirringThe reaction was stirred
6. temperaturewith continued heating for 15 minutes
7. temperatureto cool to 50° C
8. stirringThe solution was then stirred at 90° C. for an additional 1.5 hours during which the pH
9. additiondropped to 6.8 (due
10. temperatureThe contents were cooled to ambient temperature
11. filtrationThe latex solution was subsequently filtered with a 200 mesh
12. filtrationfilter

ORD record

ord-a68ea0a3f34c4527b593d9f1c7f21db6

Source dataset

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07371273B2