Preparation Of Pigment Printing Inks And Study On Fastness Properties Of Printing

Pigment printing is an ancient and young processing methods of textiles, with simple operation, clear patterns and wide applicability for all kinds of fibers. It is also friendly with the ecological environments and benefital for energy saving and environmental protection, so pigment printing has a very broad prospects of development. However, there are also many problems of pigment printing, especially the fastnes of crocking and washing is low, which is far below the high-quality requirements.In this paper, we selected several pigment inks and pastes used for printing from different manufacturers at home and abroad, and tested them on a variety of basic performance indicators. Based on a large number of printing experiments and fastness tests, we analysed the relationship between basic performance indicators of pigment inks and pastes and color fastness of printing textiles, and compared the extent of each impacts, then analysed the causes and related mechanisms of fastness problems, and the balance between printing fastness properties and other properties, such as feel, brightness and so on.Utilized the QM-1SP04 planetary ball mill to prepare pigment inks, studied on the technological features such as balls' filling ratio, balls' size and distribution, milling speed, and examine the influences of them on the particle size and distribution of pigment inks. At last, we determined the optimal process.Chose a few water-soluble hyperdispersants manufactured by different factories at home and abroad to attend the ultra-fine and decentralized treatments of Pigment Red F4R-261 through the optimum milling process. Studied on the influences of pH value, amount of dispersants and milling time on the dispersion of inks. By comparing the dispersion efficiency and printing effects of different types of hyperdispersants, we initially understood the relationship between structures and properties of hyperdispersants, and we also compared the results with the ones of conventional anionic dispersants.According to the structural requirements of water-soluble hyperdispersants,we designed and synthesized a series of water-based polyurethane block copolymer-DZP used as hyperdispersants of organic pigments.The results of the above studies show that the fastness of pigment printing textile is related to the pigment inks and binders. Particle size of inks greatly influents affects its storage stability and printing fastness. The particle size is smaller, the better is the storage stability. But the impact of particle size on the fastness is not a simple proportional relationship. The fastness is good when the particle size of pigment ink is below 100nm, but bad when the particle size is between 100-300nm, and when the particle size is up to 600nm, the fastness improved obviously. Crock fastness has little relation to the solid content of binders, but wet fastness to crocking is highly dependant on water absorptivity of binders. In addition, together with binders and pastes, pigment inks are contributed to the handle of the pigment printing textile. And the particle size of pigment ink is smaller, the handle is better.When utilizing the hyperdispersants to prepare the pigment inks , we should consider the influences of the amount of dispersants, milling time, ratio of balls versus materials, speed and other factors. Compared with the lignosulfonate dispersant, adding the hyperdispersants can not only achieve higher printing fastness, but also can improve the brightness and color depth of printed textiles, and non-ionic hyperdispersants are more effective than anionic hyperdispersants.The results of testing prove that, using waterborne polyurethane hyperdispersants of DZP series to manufacture pigment inks can achieve a higher printing fastness.