Views: 0 Author: Site Editor Publish Time: 2021-07-14 Origin: Site
Different types of fixing agents have different ingredients. What are the main components of the fixing agent?
This passage is going to talk about the followings of fixing agent:
(1) Composition of reactive fixing agent
(2) Composition of non-reactive dye fixing agent
(3) Composition of resin type fixing agent
Reactive fixing agent usually introduces reactive groups into the fixing agent molecule, which is usually used in epoxy. The fixing agent can covalently bond with some fibers in the dye molecule to form a group, and the color fastness is better. favorable. Common reactive fixatives fall into the following categories. (1) The reaction of cationic resin type fixing agent usually reacts with polycondensation of epichlorohydrin ethylene diamine and dicyandiamide (formed into epoxy group). It can not only greatly improve the color fastness of direct dyes and acid dyes, but also does not affect the color change. (2) Polyether reaction fixing agent, the fixing agent is the reaction of polyether with epichlorohydrin and non-ionic polyether. This fixing agent has a certain solubility in water, and its cross-linkable macromolecular network structure is composed of macromolecules and dyes, and the dyes are combined with fibers to improve wet rubbing fastness. (3) Qatarized reactive fixing agent, often used together with condensate trimethylamine, diethylenetriamine and epichlorohydrin, is often used as a fixing agent, but the color fastness is not very good. However, due to its cationic group and cross-linking with the fiber, it can denature the cellulose fiber, which is an effective method to increase the dye absorption rate to realize salt or low salt dyeing.
The fixing mechanism is mainly on the surface of the fiber membrane and the closed water-soluble groups. The main types are divided into cationic fixing agents and resin fixing agents.
Cationic fixing agent is mainly used in combination with the blocked water-soluble group formed by the cationic group and anionic group of the ionic dye to improve the wet fastness, but mainly divided into: cationic surface active color fixing agent, most Cationic surfactants have different degrees of fixation. These reagents include cetyl cetyl pyridinium chloride and sabamin cationic surfactants, but they have poor washing and light fastness, so they are less used. As its typical structure:
Quaternary ammonium salt has no surface activity. It is not a resin or surfactant. It contains two or more radicals and is a polyamine derivative. This fixing agent such as N + (CH3) 2 CH2CH2 N + (CH3) 2, and polyamine and cyanuric chloride polymer condensation. This kind of direct fixing agent can improve the color fastness to washing, has little effect on shadows, and has strong light fastness, but it has a certain effect on the fabric and is less used.
The fixing agent is a three-dimensional structure of water-soluble resin. It is currently the most used type of fixing agent, accounting for 70% to 80% of the total amount of fixing agent. The product is fixing agent Y.
When the chloramine and formaldehyde begin to shrink, the solution is combined with the cationic fixing agent Y, and can generate and guide dyes on the surface of the fiber membrane. Acid dyes and anionic dyes are insoluble in Tenshui Lake, thus achieving the purpose of fixing. However, due to the influence on the light resistance, adding a metal salt (such as copper salt) to the fixing agent can improve the light resistance. For example, the fixing agent M is a copper salt composite resin type fixing agent. But because copper salt may peel off the sweat solution from the fiber, it is easy to exceed the standard of heavy metal content in the fabric. Another disadvantage is that the fabric has free formaldehyde release agent, and it often cannot be reduced to the allowable range. Therefore, it is now more in line with the environmental protection requirements of formaldehyde-free or low-formaldehyde fixatives. Polyamine polymer is prepared by the reaction of guanidine and polyene polyamine compounds with hydrochloric acid, urea and helium through water-soluble resin. Generally, it does not contain formaldehyde and cations. It has a network structure and can generate macromolecular compounds and anions. The combination of dyes can improve wet fastness and increase the basic conditions of fixing agent Y and fixing agent. In China, one of the varieties of fixing agents is also developing rapidly, mainly for the fixing of reactive dyes and direct dyes.