The development history of textile softeners 
The organic silicon softener originated in the 1950s and has gone through four stages of development. 
The first generation of organic silicone softeners: The dimethyl silicone oil was emulsified using the mechanical emulsification method. However, since the silicone oil itself does not contain active groups, its bonding with the fabric is not strong enough and it is not resistant to washing. When used alone, the effect is not satisfactory. Therefore, it is rarely used as a softener nowadays. However, the dimethyl silicone oil emulsion is still widely used in other fields, such as shampoo softeners and degreasing agents; hydroxyl silicone oil, the organic silicone emulsion with a hydroxyl group cap, under the catalytic action of metals, the softener can form a network-like cross-linking on the fabric surface, enhancing the water-wash resistance, stability and softening effect. However, due to the shortcomings of being functionally single and prone to "oil separation and demulsification", it was replaced by the second generation of organic silicone softeners before being put into industrial application. 
The second-generation organic silicone softener: aminohydrocarbon-modified silicone oil, abbreviated as amino silicone oil, can be regarded as the product obtained by replacing some of the methyl groups (including side groups and terminal groups) in dimethyl silicone oil with aminohydrocarbon groups. Amino silicone oil not only retains the hydrophobicity and demolding property of dimethyl silicone oil, but also gains reactivity, adsorption property, lubricity and softness due to the presence of aminohydrocarbon groups. Therefore, it has been widely applied in fabric softening agents, polishing agents, coating additives and resin modification agents, and has become the most widely used type among carbon functional silicone oils. 
The third-generation organic silicone softener: namely, polyether-modified amino silicone oil, refers to the intermediate product of side-chain hydrogen-containing silicone oil reacting with allyl cycloalkene and allyl polyether through silanol addition reaction to obtain side-chain polyether epoxy silicone oil. Then, it undergoes ammonia ring-opening reaction with organic amine to obtain polyether-modified amino silicone oil. After the fabric is treated with it, it not only becomes soft and smooth, but also has excellent moisture absorption properties. 
The fourth-generation organic silicone softener: block-modified silicone oil. It has significantly improved in terms of softness, water-wash resistance, elasticity, and hydrophilicity, meeting various demands of users for fabrics and has become the mainstream direction of the development of organic silicone softeners at present. 
III. Block-modified Silicone Oil 
The block copolymer silicone oil can cross-link with silicone oils having similar functional groups and some other substances with functional groups to form a network structure. It forms a film on the fibers, and because the amino groups in the block copolymer silicone oil are polar, they can easily interact with some functional groups on the fibers, causing the main chain of the block copolymer silicone oil to be fixed on the surface of the fibers in a certain direction. Thus, the film formed by the block copolymer silicone oil is well anchored to the fibers of the fabric. 
This layer of film provides excellent protection for the fabric, reduces the friction coefficient between the fibers, offers various excellent properties to the fabric, and significantly enhances the washability of the silicone oil. Block-type silicone oil is a non-toxic and pollution-free green chemical product that has been widely used in the textile industry.