The Synthesis And Application Of Modified Polyurethane Pigment Printing Binder

Pigment printing is a way of printing using pigment which has no affinity andreactivity. With the help of binding agent, pigment adheres to the textile and acquiredpictures are obtained.It has simple process, bright color, complete chromatography,excellent definition, perfect sunlight fastness and no waste water. It can be applied in allkinds of fabric and blended fabric.In recent years, pigment printing is applied not noly indirect printing,but also in special printing such as cover printing, fragrance printing, raisedprinting, gold and silver powder printing and so on.The products are favored by customersat home and abroad. According to statistics, the pigment printing fabrics account for70%ofthe global printed cloth. In the United States pigment printing fabrics account for80%ofthe total. In our country great progress is made in pigment printing and it accounts for25%.The quality of pigment printing is directly related with binding agent. The hand feeling,color brilliance and fastness largely depend on the quality of binding agent. Therefore, thepreparation of high-performance binding agent is a important destination to improve thepigment printing quality.In this paper, isophorone diisocyanate (IPDI), different molecular weight polyetherpolyol,2,2-dimethylol propionic acid (DMPA),epoxy resin E-44, alkyl coupling agent(KH-550)and thiethylamine were used as raw materials and the modified polyurethanepigment printing binder was prepared by the emulsion process by themselves. Two partswere included in this paper: the synthesis and performance research of the modifiedpolyurethane binder in the first part. The application process discussion of the polyurethanemodified binder in the second part.In the first part, the temperature and time of the pre-polymerization and thetemperature and time of the chain extension reaction were discussed. The effect of R value(the ratio of isocyanate group and hydroxyl),2,2-dimethylol propionic acid (DMPA)dosage, neutral degree, the ratio of alkyl coupling agent and epoxy resin on theperformance of emulsion and film were also studied.The final optimized process was asfollows.The temperature and time of pre-polymerization were respectively65centigradeand120minutes.The temperature and time of the chain extension were respectively75centigrade and120minutes. R value was2.5, DMPA dosage was2.5percent, neutral degree was100percent. The alkyl coupling agent was3percent and the epoxy resin was4percent. The temperature and time of modify were respectively80centigrade and60minutes.The performance of modified polyurethane pigment printing binder is stable andperfect.In the second part, the effect of curing temperature, curing time, binder dosage,pigment dosage, cross-linking agent dosage on the rubbing fastness, brush fastness andhanding of fabric was studied. It was showed that the curing temperature and time wererespectively150centigrade and3minutes, binder dosage was25percent, pigment dosagewas8percent, cross-linking agent dosage was0.8percent, the visocosity was adjusted to20000～25000mpa.s by adding suitable amount of binder. The dry friction fastness ofprinting fabric using modified polyurethane binder was4-5and the wet friction fastnesswas3-4.The brush fastness was3-4and the handing is6.