KE型活性染料在可分解液体碱作用下的高温染色(二)--可分解碱存在下染料的高温固色行为

High-temperature dyeing of KE reactive dyes using decomposable liquid alkali(Ⅱ)——Fixing behaviors of dyes in the presence of decomposable liquid alkali under high-temperature

采用可分解液体碱(pH=10.0)、碳酸钠和缓冲溶液(pH=10.0)分别作为固色碱,比较了它们对KE型活性染料高温固色行为的影响。阶段染色残液pH值、染色织物得色量和残液中不同形式染料量的变化结果表明,碳酸钠的优势是供碱能力强,低温阶段染料与纤维素反应速度快;可分解碱的优势是110℃后染浴pH值随染色温度提高快速下降,已固着染料的水解损失小;缓冲溶液各项性能介于两者之间。三种碱存在下染料高温染色的结果表明:活性染料高温染色用碱剂,在低温阶段应能为染料与纤维素的反应提供较高供碱能力,而在高温阶段应能通过pH值的降低减少已固着染料的水解,这两方面对于提高活性染料的高温染色效果缺一不可。

Through comparing the changes of pH value and amount of different dye forms in dyeing resi- dues and color yield of the dyeings in different dyeing stage, the fixing behaviors of KE reactive dyes un- der high-temperature are studied with decomposable liquid alkali （pH=10.0）, sodium carbonate and buf- fer solution （pH=10.0） as fixation alkali respectively. The results show that the advantage using sodium carbonate is the dyes can rapidly react with cellulose in the stage of low-temperature dyeing due to a strong ability of alkaline donors; and the advantage using the decomposable liquid alkali is due to a rapid decline of pH value of the dye bath with the increase of dyeing temperature, as a result, the hydrolysis of the dyes are tremendously reduced when dyeing temperature exceeds 110 ℃; all the properties us- ing buffer solution of pH=lO.O are in between. Comparison of results of KE reactive dyes in high-temper- ature dyeing using three different alkalis conforms that providing a strong ability of alkali donors to main- tain the reaction between the dyes and the cellulose fibers during the low-temperature stage of dyeing, for the alkali used in high-temperature dyeing, is as crucial as reducing the hydrolysis of the dyes by de- clining pH value of the dye liquor during the high-temperature dyeing stage.