Abstract A crystalline modification, designated "β", of the dye of the structure ##STR1## The β-crystalline modification of the dye is easier to isolate from water and gives filter cakes of higher solids and color content. The β-form is also more suitable for making liquid formulations of the dye; the liquid formulations of the crystalline modification have lower viscosity and better dispersion stability than liquid formulations of non-modified form. The β-modification of the dye is obtained by heating an aqueous slurry of the dye at about 90°-95° C. and pH of 8.5 to 9.5 until the modification is complete. The crystalline modification of the dye gives Debye-Scherrer X-ray diffraction patterns substantially different from the non-modified form.
Inventors
👤 Alfred Hoehener
👤 Roy E. Smith
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-03 21:53
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0025; C09B67/0028
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
37 words
The β-crystalline form of the dyestuff of the formula ##STR3## displaying Debye-Scherrer X-ray diffraction pattern reflections representative of d-spacings (Å) as follows: 13.6(medium), 5.2(very strong), 4.9(very strong), 4.8(strong), 4.7(strong), 4.55(medium), 4.4(medium), 4.35(medium), 3.8(very strong), 3.7(medium), 2.95(very strong).
Claim 2
Dependent Claim
37 words
The β-crystalline form of the dyestuff of the formula ##STR3## displaying Debye-Scherrer X-ray diffraction pattern reflections representative of d-spacings (Å) as follows: 13.6(medium), 5.2(very strong), 4.9(very strong), 4.8(strong), 4.7(strong), 4.55(medium), 4.4(medium), 4.35(medium), 3.8(very strong), 3.7(medium), 2.95(very strong).
Claim 3
Dependent Claim
19 words
The β-crystalline form of the dyestuff of the formula ##STR4## characterized by the X-ray diffraction pattern of FIG. 1.
Claim 4
Dependent Claim
19 words
The β-crystalline form of the dyestuff of the formula ##STR4## characterized by the X-ray diffraction pattern of FIG. 1.
Claim 5
Dependent Claim
16 words
A liquid dye composition which comprises a dye of claim 1, a dispersant therefor and water.