Organic silicon emulsion


Silicone emulsion is a form of silicone oil. The following two aspects are introduced from silicone oil fabric softener and silicone oil emulsion defoamer.


I. silicone oil fabric softener


Silicone emulsion is mainly used as soft finishing agent of silicone oil fabric.


The first generation of organosilicon fabric finishing agent is a mechanical mixture of dimethylsilicone oil and hydrosilicone oil (and its derivatives); the second generation of organosilicon fabric finishing agent is a hydroxy terminated polydimethylsiloxane emulsion, which is made by emulsion polymerization of octamethylcyclotetrasiloxane monomer, water, emulsifier, catalyst and other raw materials under certain conditions. Because the polymerization and emulsification are completed in one step, it has the advantages of short working time, high efficiency, simple equipment, convenient operation, etc., and the obtained emulsion is very stable, the particles are very uniform, and the two ends of the polymer with active groups (hydroxyl) can further react to form a film, which is conducive to improving the application effect of the emulsion, which is less than the mechanical emulsification of silicone oil.


According to different surfactants, hydroxysilicone oil emulsion can be divided into cationic, anionic, non-ionic, composite ion and other types of emulsion.






1. Cationic hydroxysilicone emulsion


The emulsifier used in cationic emulsion polymerization is usually quaternary amine salt (octadecyltrimethyl ammonium chloride reported in Foreign Literature), and the catalyst is ammonium hydroxide. Cationic hydroxy emulsion can be used in finishing of all kinds of textiles. It can improve the hand feel, elasticity, smoothness and straightness of fabrics. Its other unique advantage is that it is an ideal waterproof agent for fabrics. It can be used together with methyl hydrosilicone oil emulsion. Its waterproof performance and waterproof durability can reach a very high level. It can be used as waterproof agent for vinylon canopy canvas and waterproof agent for polyester card fabric And so on.


2. Anionic hydroxysilicone emulsion


The characteristics of anionic hydroxy emulsion are good compatibility in fabric finishing agent, and the emulsion is very stable. In particular, most of the auxiliaries in textile printing and dyeing are anionic. If cationic hydroxy emulsion is used, it is easy to cause demulsification and bleaching oil, while anionic hydroxy emulsion can avoid this disadvantage, so it is more popular with users and widely used.


3. Composite ionic hydroxysilicone oil emulsion


Although cationic hydroxy emulsion is an excellent fabric soft finishing agent, it is not resistant to hard water and can not be used in the same bath with Dihydroxymethyl dihydroxyethylene urea resin (2D), catalyst magnesium chloride and anionic brightener, so it has certain limitations in use. In addition, due to the poor stability of the emulsion, organosilicon polymer is easy to be separated from the emulsion and floated on the liquid surface, commonly known as "bleaching oil". If the cationic and nonionic emulsifiers are used in the emulsion polymerization process, the disadvantages of the cationic emulsifiers in the preparation of hydroxysilicone oil emulsion can be overcome. The silicone emulsion can be used in the same bath as 2D resin, magnesium chloride and whitening agent VBL, and has good heat resistance and freezing resistance.


4. Nonionic hydroxysilicone emulsion


Nonionic hydroxy milk has better adaptability and stability than isolated hydroxy milk, so many countries have made great efforts to study nonionic hydroxy milk.


5. Organosilicon finishing agent with other active groups


In order to meet the needs of advanced finishing of all kinds of fabrics, improve the anti oil, anti-static and hydrophilic properties of silicone finishing fabrics, and make chemical fiber fabrics have many advantages of natural fabrics, silicone workers have studied the introduction of other active groups such as amino group, amide group, ester group, cyano group, carboxyl group, epoxy group, etc. The introduction of these groups makes organosilicon fabric finishing agent have special effects, for example, the introduction of amino group into organosilicon molecule is suitable for preshrunk and soft finishing of wool; the introduction of amide group is suitable for antifouling finishing, and the softness is greatly improved: the introduction of cyano group has good oil resistance, and the anti-static effect of the copolymer of polyoxyethylene ether and organosilicon is good; the organofluorine modified organosilicon has oil repellency Anti pollution, anti-static, water repellent and many other advantages.


Transferred from rubber technology studio Li Xiuquan