- Dichroic dye and microencapsulated liquid crystal composition thereof
-
Dichroic dyes, compositions thereof, and liquid crystal compositions, microencapsulated liquid crystal compositions and liquid-crystal display elements employing the same. The dichroic dyes have high photostability in addition to excellent solubility. Furthermore, the liquid crystal composition employing the above dichroic dyes can have an orientational order parameter more than 0.7.
- -
-
-
- Process for the preparation of 1,5-dichloroanthraquinone
-
A process has been invented for the preparation of 1,5-dichloroanthraquinone which comprises reacting 1,5-dichloroanthraquinone with chlorine in the presence of at least 50% by weight of liquid phthalic anhydride, relative to the weight of 1,5-dinitroanthraquinone employed. The 1,5-dichloroanthraquinone is known to be a valuable starting material for the preparation of various dyestuffs.
- -
-
-
- Triazinyl dyes
-
Vat dyestuffs of the formula EQU1 wherein R represents alkyl with 1 to 4 carbon atoms, R1 and R2 represent hydrogen or alkyl with 1 to 4 carbon atoms and each of A1 and A2 represents a vattable radical with 3 to 7 condensed rings are characterized by improved resistance to alkali and are suitable for dyeing and printing the most diverse materials, in particular fibers made from natural or regenerated cellulose.
- -
-
-