Colored Nylon via Condensation Dye Chromogenic Groups

The patent introduces dyeing auxiliary groups (such as carboxyl groups, hydroxyl groups, or amine groups) into the nylon molecular chain before the actual dyeing process. These auxiliary groups are pre-installed at specific positions along the polymer chain to facilitate subsequent dye binding, ensuring uniform and stable coloration that resists fading in organic solvents.

The patent uses dyeing auxiliary groups as intermediary structures that mediate between the nylon base polymer and the dye molecules. These auxiliary groups act as binding sites that form strong interactions (hydrogen bonds, ionic bonds, or coordination bonds) with dye molecules, enabling stable color fixation without relying on weak physical forces alone.

The patent segments the dyeing process into two distinct stages: first, introducing dyeing auxiliary groups into the nylon molecular chain through controlled polymerization; second, adding dye molecules that bind to these auxiliary groups. This segmentation allows each stage to be optimized independently, ensuring complete reaction and uniform distribution without the drawbacks of attempting to incorporate dye directly during polymerization.

The patent applies local quality by introducing dyeing auxiliary groups at specific locations within the nylon molecular chain rather than uniformly throughout. This localized modification creates specific binding sites that enhance dye attachment while maintaining the overall properties of the nylon polymer, resulting in both complete reaction and uniform water-resistant coloration.

The patent replaces the traditional high-temperature mechanical heating process with a chemical mechanism-based dyeing approach. By introducing functional groups that enable low-temperature chemical bonding between dye and nylon, the process eliminates the need for high-temperature steam or hot water treatment, dramatically reducing energy consumption while maintaining effective dyeing.

The patent changes the fundamental parameters of the dyeing process by introducing chemical functional groups that enable dye binding at much lower temperatures than traditional methods. This parameter change from high-temperature physical processes to low-temperature chemical processes reduces energy consumption and minimizes pollution while achieving equivalent or superior dyeing effectiveness.