Abstract:

In order to improve the stability of the paste form of pigment and facilitate the pigment dyeing process, a waterborne polyurethane-acrylate coated pigment adhesives was prepared from  polyurethane as shell and pigment-polyacrylate as core by emulsifier-free emulsion polymerization. It was used for pigment pad dyeing of cotton fabric. The size distribution, mean diameter and surface morphology of polymer emulsions were characterized by nanometer particle sizer and transmission electron microscopy. The pigment dyeing process was optimized by adjusting the dosage of waterborne polyurethane-acrylate coated pigment adhesives, sodium alginate, padding process and drying and curing parameters on the padding process. The results showed that waterborne polyurethane-acrylate coated pigment latex particles exhibit obvious core-shell structure. The mean diameter is 126 nm. The dyed fabrics also show higher coloration when the dosage of sodium alginate is 0.2%, pre-dryed at 80 °C and cured at 140 °C by two-dipping-two-padding. The dyed fabrics displayed good flexibility after softening finishing with dry crocking fastness up to 4-5 level, wet crocking fastness up to 4 level and soaping fastness reached grade 4.

Key words: waterborne polyurethane-acrylate, coatd pigment adhesive, cotton fabric, pigment dyeing