直接染料2.ppt

1、Direct Dyes（直接染料）,Direct Dyes (直接染料),What is direct dye?,Direct dyes are a class of dyes with a high affinity for cellulosic fibers ,such as cotton ,rayon.(对纤维素纤维无需媒染剂而直接上染的一类染料)。,Dyeing Principle（染色原理）,dye-fiber force(与纤维的作用力)Van de waals force and hydrogen bonds(范德华力和氢键).,Use property,low cost ,wi

2、de range of color , simple dyeing procedure , moderate to poor washing fastness , requirement of aftertreatment。 价格低廉,色谱齐全,使用方便,中等到差的水洗牢度,需要固色处理。,The most common classification of direct dyes is that of the Society of Dyers and Colourists (SDC),直接染料最常用的分类是SDC（英国染色工作者学会）分类,根据染料浸（竭）染时的匀染性及其对染色温度和中性电解质

3、的敏感性等染色性能的不同分类。,Based on their leveling ability and their response to increase in the dyeing temperature and to added salt during exhaust dyeing.,Classification of direct dyes (直接染料分类),SDC Class A Direct dyes (匀染性直接染料）low molecular weight(mono- and bis-azo dyes with several anionic sulphonate groups

4、 per molecule)，good migration，good water-solubility， low substanvity, they require considerable amounts of salt for good exhaustion and need to be dyed at lower temperature(7080).,这类染料相对分子量低，一般为单偶氮或双偶氮带有一些磺酸基团的染料，移染性好，水溶性好，对纤维的亲和力低，为了提高上染率，一般要加入大量的盐促染，染色温度不宜太高，一般在7080,SDC Class B Direct dyes (盐效应直接染

5、料，Salt-sensitive or salt-controllable dyes）higher molecular weight(bis- and tris-azo dyes with just a few sulphonate groups per molecule),low to moderate substantivity in the absence of salt but give much increased exhaustion on addition of small amounts of salt to the dyebath.higher washing fastnes

6、s. The addition of salt must be carefully controlled to obtain the level dyeing.,这类染料的相对分子量高，常为双偶氮或三偶氮带有较多的磺酸基团，在没有盐的情况下对纤维的亲和力较低到中等，但是加入大量盐后可获得较高的上染率。该类染料有较高的水洗牢度。控制盐的加入量以获得匀染。,SDC Class C Direct Dyes (温度效应直接染料，temperature-controllable dye)higher molecular weight (polyazo dyes with few sulphonate g

7、roups), high sustantivity and poor migration. Level dyeing depends on the gradual increase of the dyeing temperature and subsequent additions of limited amounts of salt. Leveling agent may be required。,这类染料相对分子量高，常为多偶氮基团，染料分子中含有的磺酸集团较少，对纤维的亲和力高，移染性差，其上染可由缓慢的升温速率和盐的加入量来控制，可加入匀染剂。,Dyeing procedure（染色过程） Dissolving and addition of dyes（化料） Heating the dyebath（升温） Helding for some period of time（保温） Addition of salt（加盐） Rin