Synthesis And Application Of Fixing Agents For Acid Dyes

Since the fixing effect of many acidic fixing agents on the market are not ideal, especially in improving the wet fastness, with environmental damage and other short-comings, Two acidic fixing agents were prepared and were applied to the acid dyeing nylon fabrics in fixing processing.(1) An acidic fixing agent SBNF was using the main raw materials of bisphenol A,2-naphthol and formaldehyde, by adding scavenger to reduce the content of free formaldehyde, and combined with vacuum distillation method.(2) A formaldehyde-free polyacrylic acidic fixing agent3A was prepared with Acrylic acid (AA), acrylamide (AM),2-acrylamido-2-methyl propane and sulfonic acid (AMPS) as raw materials, and ammonium persulfate as the initiator of the solution polymerization.(3) The configuration and properties of the two acidic fixing agents, were characterized by FTIR and SEM, as well as the performance of solid color fastness, color aberration and hand feel.(4) Best synthesis process of the fixing agent SBNF was got by optimizing the process. The ratio of the quality of sulfonated intermediate I, sulfonated intermediate Ⅱ and formaldehyde solution was2.0:1.0:1.0, reacted for6h in100℃. And the fixing process was optimized as follows:2.5%fixing agent SBNF (owf),10%Scavenger (owf), processing30min at80℃, with3.0of the fixing bath pH. Fixed by the fixing agent SBNF, the fastness to washing up was improved to4grade, dry rubbing fastness4grade, wet rubbing fastness grade3-4and perspiration4; the content of formaldehyde was20mg/kg, meeting the application requirements.(5) By single factors tested, better synthesis conditions of the formaldehyde-free fixing agent3A was as follows:water and ethanol were used as the mixed solvent; ammonium persulfate were used as the initiator; the monomer mass fraction was50%; the monomer mass ratio m (AA):m (AM):m (AMPS) was6:1:2; initiator mass fraction was1%; the feeding method of the initiator was continuous dropping; the target product was available by reacting for3h at70℃in water bath. Better fixing conditions:fixing solution pH value was2.0; liquor ratio was1:30; fixing agent was3%of the fabric weight; the dyed nylon was finished at80℃for40min in the fixing bath. The soaping fastness, friction fastness and perspiration fastness of the fixed nylon were significantly improved. Fixed by the fixing agent3A, the fastness to washing up was improved to4grade, dry rubbing fastness4grade, wet rubbing fastness grade3-4and perspiration4. The raw materials and products do not contain formaldehyde, compared with the market acidic fixing agent, and are more environmentally friendly products.