A New Method of Determining the Solubility of Disperse Dyes

Abstract

The polymer cell method (MPC) ‐ a new method to determine solubility o f disperse dyes, applicable between 80° and 140°C is described. This method is compared to the pressure filtration method. The results obtained using the two methods were found to be in good agreement. The application of the MPC method for determining solubility was investigated in the presence of levelling agents (Palegal A, B, HT, Sandogen PES, Invalon HTB) and was used to study the dyeing equilibria of a two‐step mechanism of disperse dyeing, i.e. dissolution of the dye dispersion and sorption of it by the substrate.

The roles of polymer relaxation phenomena, aqueous dye solubility and the physical properties of water in the mechanism of adsorption of a disperse dye on poly(ethylene terephthalate) fibres: Part 2 dye solubility

“…In terms of their exhaust application to PET and other types of hydrophobic fibre, the most important and distinctive attribute of disperse dyes is their low aqueous solubility, which means that dyeing takes place from a fine aqueous dispersion of the dye that is present within the aqueous disperse dye dyebath (from which the dye class derives its name). For general accounts of the solubility of disperse dyes, see, for example 10,14–23 …”

“…For general accounts of the solubility of disperse dyes, see, for example. 10,[14][15][16][17][18][19][20][21][22][23] It is well known that the characteristic low aqueous solubility of the dyes, which depends on the particular physical form of the colourant (eg crystal form, particle size, particle size distribution 4 ), increases, markedly, with increasing temperature 10,14,17,20,[24][25][26] (eg solubility of pure disperse dye in water: CI Disperse Red 60 6.4 Â 10 À7 g L À1 at 25 C, 7.4 Â 10 À3 g L À1 at 130 C; CI Disperse Yellow 54 7.4 Â 10 À7 g L À1 at 25 C, 3.3 Â 10 À3 g L À1 at 125 C 24 ), as illustrated by the data presented in Figure 3. Nonetheless, disperse dyes still possess remarkably very low solubility, even under the conditions encountered in HT dyeing processes (ie 130/140 C).…”

The roles of elevated temperature and carriers in the dyeing of polyester fibres using disperse dyes: Part 1 fundamental aspects

“…As such, from the viewpoint of their exhaust application to PET and other types of hydrophobic fibre, under both HT and Carrier dyeing conditions, the most important and distinctive attribute of disperse dyes is their remarkably low aqueous solubility, which depends on the particular physical form of the colourant, such as crystal form, particle size, particle size distribution, etc. (eg 4,63,459,[475][476][477][478][479][480][481][482][483][484][485][486][487][488] ), and which increases with increasing temperature 63,104,482,489 (eg solubility of pure disperse dye in water/g l À1 : CI Disperse Red 60 0.00000064 at 25 C, 0.0074 at 130 C; CI Disperse Yellow 54 0.00000074 at 25 C, 0.0033 at 125 C 490 ). However, Table 7 clearly shows that disperse dyes possess very low solubility, even under the elevated dyeing temperature conditions (typically 130 C) encountered in HT dyeing processes.…”

The role of inorganic electrolyte (salt) in cellulosic fibre dyeing: Part 2 theories of how inorganic electrolyte promotes dye uptake

“…22 Indeed, aqueous dye solubility in general has received surprisingly little interest, attention being principally focussed on that of disperse dyes. [145][146][147][148][149][150][151][152][153][154][155][156][157][158] F I G U R E 1 7 Effect of NaCl and temperature on the solubility of purified C.I. Direct Yellow 12; drawn using data from 162 | 567…”