DYE OF THERMALLY STABLE CRYSTAL FORM, PREPARATION OF THE SAME AND METHOD FOR DYEING HYDROPHOBIC FIBER USING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a dye of a crystal form which provides excellent dyeing stability in a high temperature dyeing and does not produce a tar-like substance or a coagulation product which inhibits dye fixing by choosing a specific disperse dye of an azo type having a crystal from having relatively intense peals at specific plural diffraction angles in the power X-ray diffractometry using Cu-K α ray. ;SOLUTION: In an azo disperse dye which has formula I, there is chosen a crystal form having relatively intense peaks at diffraction angles (2θ)[°] of 8.3, 10.4, 18.8, 23.2, 25.2 and 28.2 in the powder X-ray diffractometry using Cu-K αray (β-type crystal). A mixture of a dye of formula I and a dye of formula II, wherein the content of the dye of formula II is 30%, is preferably used. This dye of the above crystal from can be produced by heat-treating a thermally nustable dye of formula I having α-type crystal form which is produced by a known method in an aqueous solution containing a water-soluble organic solvent or an anionic or nonionic surfactant at a temperature of 15°C or higher.;COPYRIGHT: (C)1998,JPO