Abstract:

Objective In order to address the long dyeing process, large pollution and low pigment printing fastness in the coloring process of polyester/cotton blended fabrics, styrene and butyl acrylate were polymerized on the surface of the dye by emulsion polymerization to synthesis new red, yellow and blue colored latex particles. The colored latex particles were used as adhesive-free printing colorants for polyester and polyester-cotton fabrics. Using the screen-printing technology, the colored latex particles were used to prepare a binder-free and high printing fastness of colored polyester-cotton printed fabrics.

Method The ammonium persulfate initiator was added to the pre-emulsion to initiate the polymerization of the monomer on the surface of the dye. The mixed solution of dye, styrene and butyl acrylate was added to the aqueous solution of emulsifier, which were then stirred at high speed for 20 min to obtain the pre-emulsion until the completion of the polymerization reaction to obtain colored latex particles. The prepared latex particles are mainly composed of dyes and polymers, where the polymer formed a uniform and complete film on the surface of the fabric, anchoring the dye to the surface of the fabric and imparting color fastness to the print.

Results The study was focused on the effects of different factors on the formation of latex particles and their printing properties. The microscopic morphology, thermal properties, particle size and particle size distribution, stability and printing properties of colored latex particles were studied. The effects of emulsifier composition, hard to soft monomers ratio and baking temperature on the preparation and printing performance of latex granules were explored. With the increase of OP-10 emulsifier, the particle average size of latex particles showed a gradual increase trend, and the dispersion coefficient gradually decreased. With the proportion of soft monomers increase, the particle average size became larger with a decrease in dispersion coefficient. Particle size and hard to soft monomers ratio have an impact on color. The increase of particle size and the proportion of soft monomers were found to be conducive to the increase of K/S value. According to the changes of △E before and after rubbing, the effects of different factors on printing fastness were explored. The increase in the proportion of soft monomers was conducive to the printing fastness of the fabric, but it would affect the hand feel of the fabric. Baking temperature exhibited little effect on rubbing fastness. Through experiments, the optimal preparation process of latex particles was obtained, where OP-10 emulsifier accounted for 5/8 of the total emulsifier, R-4006 emulsifier accounted for 2/8 of the total emulsifier, and R-4001 emulsifier accounted for 1/8 of the total emulsifier, and the ratio of soft to hard monomers was 1∶1.

Conclusion In this work, the red, yellow and blue nano-latex particles that can be used for binder-free printing were successfully prepared. The prepared latex particle average size is within 200 nm, the dispersion coefficient is below 0.1, the centrifugal stability and heat resistance stability are more than 95%. The colored latex granules show a small particle size, uniform particle size distribution and high stability. In the case of printing without binder, the soaping fastness of latex particle printing on polyester can reach 4 grades, and the dry and wet friction fastness can reach 3-4 grades; whereas the soaping fastness on polyester cotton can reach 3-4 grades, and the dry and wet rubbing fastness can reach 3-4 grades. The color of the printed fabric is uniform and bright, and the printed fabric has good color fastness.

Key words: colored latex particle, printing, polyester/cotton blended fabric, color fastness, adhesive-free, emulsion polymerization, dye