Vazo 67

Example 2

30 g of n-butyl acetate (Merck, 101974) are pre-heated to 85° C. (temperature at the heating block) in a 100 ml 3-neck flask equipped with reflux condenser, nitrogen supply, and septum. 5.0 g of mono-terminated polydimethylsiloxan methacrylate (ABCR, AB146684), 0.5 g of (2,3-Epoxypropyl)-methacylate (Merck, 800609), 4.5 g of 2-tert-Butylaminoethylmethacrylate (Aldrich, 444332), and 0.12 g of Vazo 67 (DuPont) are combined and metered into the reaction vessel over a period of 2 h using a syringe pump. After addition of the reactants, an additional 0.12 g of Vazo 67 is added and the reaction is allowed to continue for 2 h.

1.0 g of the resulting polymer solution and 2.0 g of TiO₂ particles (DuPont, Ti-Pure R960) are combined and subjected to ultrasound for 45 min in an Ultrasoundbath (VWR Ultrasonic bath, USC600TH, 260 W output). The resulting dispersion is filtered through a 50 micron cloth (SEFAR NITEX 03-50/1). Afterwards, the particles are deposited (benchtop centrifuge, RCF=3000, 20 min) and redispersed in fresh dodecane thrice.

Electrophoretic inks with 3% wt of the prepared particles and 3% wt additive are prepared and the Zetapotential characterised using a Malvern Zetasizer Nano ZS.

With Aerosol OT (Aldrich, 323586) a Zetapotential of +4 mV, and with Span 85 (Aldrich, S7135) a Zetapotential of +3 mV is found.

Example 12

50.0 g dodecane were heated to 75° C. (temperature inside the reaction vessel) in a 250 ml three-neck flask. A mixture of 16.0 g methacrylate terminated polydimethylsiloxane (ABCR, AB116684), 24.0 g 2-(tert-Butylamino)ethyl methacrylat (Aldrich, 444332), 1.0 g Vazo 67 (DuPont), and 43.3 g dodecane is added to the reaction mixture over a period of 1.5 h. After one additional hour, 1.0 g of Vazo 67 is added and the reaction allowed to continue for 2 hours.

A 30% solution of polymer stabilizer is obtained.

Example 8

24.0 g Dodecylmethacrylate (Merck, 800589), 8.9 g (2-(Methylacryloyloxy)ethyltrimethyl ammoniummethylsulfat (Aldrich, 408123), 1.2 g 2-Mercaptoethanol (Merck, 805740), and 50.0 g 2-Propanol (Merck, 109634) are combined in a 250 ml three-neck flask equipped with reflux condenser and argon supply. The reaction mixture is heated to 90° C. and the setup is flushed with argon, 0.2 g Vazo 67 (DuPont) is added and the reaction is continued for 6 hours.

2.5 g of the resulting polymer, 20.0 g 2-Propanol (Merck, 109634), 25.7 g Dodecane (Aldrich, 386707), and 10.0 g TiPure R960 (DuPont) are combined in a 100 ml round bottom flask and homogenised. Remaining volatile components are removed using a rotator evaporator until no further condensation at 60° C. and 2 mbar is observed. Subsequently, the dispersion is stirred for 3 hours at 120° C. The resulting dispersion in Dodecane has a solid content of 38.6% and exhibits dispersed particles under an optical microscope.

Electrophoretic inks with 3% wt of the prepared particles and 3% wt additive are prepared and the Zetapotential characterised using a Malvern Zetasizer Nano ZS.

With Aerosol OT (Aldrich, 323586) a Zetapotential of +43 mV, and with Span 85 (Aldrich, S7135) a Zetapotential of +0 mV is found.