The present invention relates to a new crystal form of the compound of formula and a process for its preparation. The compound may be used in compositions for inks, paints and plastics, especially in a wide variety of printing systems and is particularly well-suited for security applications.

##STR00001##

A method for chlorinating blue anthrone, violanthrone or isoviolanthrone is provided. Reaction is carried out with a chlorinating agent (any one of sulfonyl chloride, thionyl chloride and triphosgene) in a reaction solvent (a Lewis acid ionic liquid with anions being of a transition metal halide) for 2 h to 40 h at a chlorination temperature not lower than room temperature and not higher than 120° C.; and then the reaction product is subjected to post-treatment to obtain a target product. The present disclosure cuts off a generation route of harmful substances such as dioxins and their derivatives from the source. There are no dioxins or similar substances generated in the product, and the reaction has high atomic utilization rate and low energy consumption, which fills the gap in the field of chemical technologies at home and abroad.

In one aspect, floor coverings are described herein comprising nylon fibers dyed with at least one vat dyestuff, the dyed nylon fibers exhibiting enhancements to lightfastness, color fastness, wet fastness and/or resistance to household bleach.

In one aspect, floor coverings are described herein comprising nylon fibers dyed with at least one vat dyestuff, the dyed nylon fibers exhibiting enhancements to lightfastness, color fastness, wet fastness and/or resistance to household bleach.

A coloring composition which contains an isoindoline compound represented by formula (1) (wherein A represents a group that is expressed by formula (2), formula (3) or formula (4)) and a dispersion medium.

##STR00001##

The present disclosure provides stabilized hematoxylin formulations having a pH of less than 2.4. The present disclosure also provides methods of using such stabilized hematoxylin formulations to stain biological samples.

Methods and compositions for removing precipitates or reducing the formation of precipitates generated in hematoxylin solutions. The methods and compositions feature cleaning solutions that feature chemical compounds that initiate processes including but not limited to acidification of the waste solution, chelation of metal ions in the waste solution, reduction reactions, oxidation reactions, and metal salt addition reactions.

Methods and compositions for removing precipitates or reducing the formation of precipitates generated in hematoxylin solutions. The methods and compositions feature cleaning solutions that feature chemical compounds that initiate processes including but not limited to acidification of the waste solution, chelation of metal ions in the waste solution, reduction reactions, oxidation reactions, and metal salt addition reactions.

The present invention relates to a technique for providing a quinacridone solid solution pigment, by which a quinacridone solid solution pigment that allows a colored product to have high chroma and a properly yellowish hue, and suitably, that has a controlled particle diameter and has the above-described, desired hue can be obtained. The present invention provides a method for producing a quinacridone solid solution pigment, wherein a diarylaminoterepththalic acid and a dialkylarylaminoterephthalic acid are subjected to a co-cyclization reaction in polyphosphoric acid, thereby obtaining a water-containing crude quinacridone solid solution such that water is contained in a solid solution having a mass ratio of unsubstituted quinacridone to a 2,9-dialkylquinacridone of 85:15 to 60:40; the water-containing crude quinacridone solid solution obtained above is dried in a drying step, thereby obtaining a powdery, crude quinacridone solid solution having a water content of less than 1%; and the powdery, crude quinacridone solid solution is heated in a liquid medium that does not dissolve the crude quinacridone solid solution in a pigmentation step, and the present invention also provides a pigment dispersion liquid and an inkjet ink each containing the obtained quinacridone solid solution pigment.

The present disclosure provides stabilized hematoxylin formulations having a pH of less than 2.4. The present disclosure also provides methods of using such stabilized hematoxylin formulations to stain biological samples.