For the dyeing of cellulose fibers, the proportion of reactive dyes is currently the largest. Reactive dyes are water-soluble dyes containing reactive groups that can chemically combine with macromolecules such as cotton, wool and silk, so the soaping and rubbing of dyed fabrics The fastness is very high. Commonly used leveling agents generally include non-ionic surfactants. In addition to non-ionic surfactants, anionic leveling agents and nonionic and anionic surfactants are often used in recent years.
1. Non-ionic surfactants
The hydrophobic groups of commonly used 1F ionic surfactants can be higher alcohols, higher fatty acids, higher alkyl amines, etc. The hydrophobic groups are above C12, and long-chain alkyl groups of C16 and C18 are ideal, which can be affinity with polyoxyethylene. The water base forms the form of ether bond, ester bond, amine bond, etc.
Commonly used leveling agent Pingping 0, leveling agent 102 and leveling agent OP have a certain leveling effect on reactive dyes. Because this type of leveling agent contains polyoxyalkyl ethers in the long molecular chain, it can form relatively loose oxygen bonds with the hydroxyl (-OH), amino (-NH) and other groups in the dye molecule.
On the one hand, it will combine with the dye in the dye solution to form a relaxed complex, which will hinder the adsorption of the dye, thereby playing a slow-dyeing effect; on the other hand, it can enhance the interface migration and the entire migration of the dye. Further promote the uniform adsorption of the dye. For example, the leveling agent WE for wool, which is aliphatic amine polyoxyethylene ether, is of non-ionic/weak cationic type. It is mainly used as a leveling agent for reactive dyeing of wool, which can increase the amount of color. Affects the percentage of dyeing, and has excellent leveling effect when used in medium, neutral, weak acid and metal complex dyes.
2. Anionic surfactant
Anionic disperse leveling agents are dye-affinity leveling agents. Anionic surfactants have the same ionic type as reactive dyes. They use the mechanism of preempting the dyeing mat to slow down the dye uptake.
Leveling agent EDER is an anionic leveling agent with a chemical composition of aromatic polysulfonate compound. It is a relatively new type of anionic leveling agent. Its advantages are as follows: (1) The leveling agent EDER has a certain chelating and dispersing adjustment function for calcium, magnesium and other heavy metal ions to improve the quality of the dye; (2) In the |: dye adsorption stage, it has excellent performance Slow dyeing performance, control the dye uptake and adsorption uniformly; (3) In the fixing stage, buffer the pH of the dye bath to ensure stable and even fixation of the dyes and avoid uneven fixation; (4) No adverse effects on the dye fastness of the fabric.
3. Compounds of non-ionic and anionic surfactants
Non-ionic surfactants obtain a slow dyeing effect through the combination of oxygen atoms on polyoxyethylene bonds with dye molecules through oxygen bonds. At present, most of the nylon leveling agents provided by auxiliary manufacturers are anionic/non-ionic composite leveling agents.