Silicone emulsion is mainly used as a softening and finishing agent for silicone oil fabrics. The first generation of silicone fabric finishes were mechanical blends of dimethicone and hydrogenated silicone oils (and their derivatives). The second-generation silicone fabric finishing agent is a hydroxyl-terminated polydimethylsiloxane emulsion, which is made of octamethylcyclotetrasiloxane monomer, water, emulsifier, catalyst and other raw materials under certain conditions. aggregated. Since the polymerization and emulsification are completed in one step, it has the advantages of short working time, high work efficiency, simple equipment, convenient operation, etc., and the obtained emulsion is very stable, the particles are very uniform, and the obtained polymer has active groups (hydroxyl groups at both ends) ) can be further reacted to form a film, which is beneficial to improve the application effect of the emulsion, which is inferior to the mechanical emulsification of silicone oil.

Hydroxy silicone oil emulsion can be divided into cationic, anionic, nonionic, composite ionic and other types of emulsions according to the different surfactants used.

1. Cationic hydroxyl silicone oil emulsion

The emulsifiers used in cationic hydroxy emulsion polymerization are generally quaternary ammonium salts (octadecyl trimethyl ammonium chloride reported in foreign literature), and the catalyst is ammonium hydroxide. Cationic hydroxy emulsion can be used in the post-finishing of various textiles, and has the properties of improving fabric hand, elasticity, smoothness and stiffness of fabrics; its other unique advantage is that it is an ideal waterproofing agent for fabrics, and it can be used together with methyl hydrogen silicone oil emulsion. , Waterproof performance and waterproof durability can reach a very high level, can be used as a waterproofing agent for vinylon canopy canvas, a waterproofing agent for polyester card cloth, etc.

2. Anionic hydroxy silicone oil emulsion

Anionic hydroxy emulsion is characterized by good compatibility in fabric finishing agents, and the emulsion is very stable. In particular, most of the auxiliaries in textile printing and dyeing are anionic. If cationic hydroxyemulsion is used, it is easy to cause demulsification and oil leaching. Anionic hydroxyemulsion can avoid this drawback, so it is more popular with users and has a wide range of uses.

3. Complex ionic hydroxyl silicone oil emulsion

Although cationic hydroxy emulsion is an excellent fabric softening and finishing agent, this emulsion is not resistant to hard water and cannot be bathed with dimethylol dihydroxyethylene urea resin (2D) resin, catalyst magnesium chloride and anionic brightener use, so there are certain limitations in use. In addition, due to the poor stability of the emulsion, the silicone polymer is easily separated from the emulsion and floats on the liquid surface, commonly known as "floating oil". If the cationic and nonionic emulsifiers are used for compounding in the emulsion polymerization process, the disadvantages of cationic emulsifiers in preparing hydroxy silicone oil emulsions can be overcome, and the prepared silicone emulsions can resist hard water and have good heat resistance. and freezing resistance.