Abstract:
The description is concerned with a liquid crystal composition of the guest-host type which contains a pleochroic dye dissolved therein. The dye molecule has an end group or end groups in the molecule represented by the general formula: ##STR1## where Ro designates a straight chain of alkyl group, in which methylene group not adjacent to the nitrogen atom may be substituted by oxygen atom or sulfer atom; R1 designates an alkyl group having a chain length different from that of the alkyl group of Ro or a group ##STR2## in R1 a methylene group not adjacent to the nitrogen atom may be substituted by oxygen atom or sulfur atom, and R2 designates hydrogen atom, alkyl group, alkoxy group, cycloalkyl group or dialkylamino group.
Abstract:
Dyes of the formula ##STR1## where X and Y, for example, can be hydrogen or halogen and R can be alkyl among other substituents. The dyes are derived from an O-nitroaniline diazo component and an N-substituted homophthalimide as coupling component. The dyes are greenish yellow to orange and give clear dyeings of good color strength and having good general fastness properties on polyesters, cellulose esters and in some cases also on polyamides. The fastness to light and the fastness to heat setting are excellent and may easily be influenced by the choice of substituents.
Abstract:
Disazo dyestuff which in the form of the free acid correspond to the formula ##STR1## in which W stands for the radical ##STR2## or the radical ##STR3## R.sub.1 stands for hydrogen, an alkyl radical or a phenyl group; R.sub.2 and R.sub.3, independently of one another, stand for hydrogen, halogen, an alkyl group, an alkoxy group or an acylamino group; R.sub.4 stands for hydrogen, halogen, an alkyl group, an alkoxy group or an acylamino group; R.sub.5 stands for hydrogen, an alkyl group or an alkoxy group; R.sub.6 and R.sub.7, independently of one another, stand for hydrogen, hydroxy, cyano, halogen, acyloxy, alkoxycarbonyl or phenyl; X stands for an alkylene radical with 1 - 4 carbon atoms; R.sub.8 stands for an alkyl, phenyl, 2-naphthyl or 4-biphenyl group which is not further substituted; R.sub.9 stands for hydrogen or an alkyl group with 1 - 6 carbon atoms which may be substituted by a nitrile, carboxamide or carboxyl group; R.sub.10 stands for a substituent; and n stands for the numbers 0 - 2.This dyestuff is suitable for dyeing synthetic fibers, especially polyamide fibers, with very good fastness to light.