Correlation between solid content and viscosity of a polymerizable cholesteric liquid crystal formulation
Publication Date: 2013-May-08
Page 01 of 3
Authors: Dr. Jochen Brill, Thomas Musiol, Dr. Oliver Seeger
Address: BASF SE, 67056 Ludwigshafen
Key words: Cholesteric liquid crystals, viscosity, printing
Full text: The correlation between the solid content and the viscosity of a polymerizable cholesteric liquid crystal formulation was investigated. The formulation allows to control the viscosity in a wide range between 10 and 160 mPa x s. Independently from the viscosity chosen an excellent orientation of the liquid crystals can be achieved.
The wide range of viscosity allows various printing and coating technologies including inkjet-, flexo-, gravure- and screen printing as well as all types of roll- or reverse roll coaters, knife coater and knife reverse roll coater (krrc).
Formulation: nematic monomer Ib in WO 2009/153287 chiral dopant IVa in WO 2009/153287 Photoinitiator Lucirin TPO
BYK 361 N (1%) in solvent
between 40% and 67% ( with
respect to the total solid content)
The following ratios solvent : solid content were formulated by mixing all components at room temperature with a magnetic stirrer until a clear solution was obtained
Cyclopentanone : Solid content
67% 33% 60% 40% 50% 50% 47% 53% 44% 56% 40% 60%
All formulations were measured with a haake mars rheometer (Cone C60/1°H, D=60mm).
5% of solid content (with respect to
the sum of nematic and chiral dopant)
0,05% of solid content (with respect
to the sum of nematic and chiral dopant)
Page 02 of 3
The cholesteric liquid crys...