Development of Silicone Softener
Softener is a textile auxiliary that can be adsorbed on the surface of fibers, reduce the dynamic and static friction coefficients of fibers, and weaken the frictional resistance between fibers and between fibers and the human body. At present, there are many kinds of softeners developed on the market, among which surfactant-type softeners, reactive softeners, silicone softeners, etc. are used more. Among these softeners, silicone softeners have the most outstanding performance and are widely used in the functional finishing of various natural and synthetic fiber fabrics. Its development has roughly gone through the following four stages.
The first generation of silicone softener is polydimethylsiloxane (methyl silicone oil), and the silicone oil is generally emulsified by mechanical emulsification. This kind of softener can endow the fabric with better softness and heat resistance, and can improve the hand feel and softness and smoothness of the fabric to a certain extent, but since the molecular chain of methyl silicone oil does not contain reactive groups, it cannot interact with fibers. The reaction also cannot crosslink itself, so it has poor wash resistance. At present, it is rarely used as a softener in the textile field.

The second-generation silicone softener is a kind of hydroxyl silicone oil formed by substituting hydroxyl groups at both ends of the molecular chain of methyl silicone oil. Hydroxyl silicone oil can cross-link with fibers and form a protective film on the surface of fibers, thereby reducing friction between fibers, enhancing the softness of fibers, and has better washability. Its stability and use effect are better than those of the first generation products. Big improvement. Although there is a hydroxyl group at the end of the molecular chain, it is helpful to improve its hydrophilicity and emulsion stability, but because the stability of the emulsion is difficult to control, it is prone to oil floating when it is applied, and it is necessary to pay attention to the oil spots on the fabric after finishing. disease.

The third-generation silicone softener is polyether-modified amino silicone oil. After the fabric is treated with it, it is not only soft and smooth, but also has excellent hygroscopicity. During use, the finished fabric is prone to yellowing, which is because the amino group (especially the primary amino group) is easily oxidized at high temperature, resulting in yellowing of the fabric. In addition, due to the strong polarity of the amino group increases the adsorption, but lacks hydrophilic groups, it will produce stuffy and airtight conditions when the fabric is worn.

The fourth generation silicone softener is block modified silicone oil. Block silicone oil can cross-link with silicone oil with similar functional groups and some substances with other functional groups to form a network structure, forming a thin film on the fiber, and because the amino group in the block silicone oil is polar, it is easy to interact with some of the fibers. The functional group interacts to fix the main chain of the block silicone oil on the surface of the fiber in a certain direction, so that the film formed by the block silicone oil is well anchored on the fiber of the fabric. It has been greatly improved in softness, washing resistance, elasticity and hydrophilicity, and has become the mainstream direction of the development of silicone softeners.