Silicone release agents have been used in the molding, casting and encapsulation of plastics, rubbers, polymers, metals, glass, molds and foods. The molding process of plastic is the most important application object of silicone release agent.
For example, in the processes of molding, transfer molding, injection molding, casting molding, lamination molding, etc. of polyurethane, polystyrene, polyvinyl chloride, melamine, acrylic resin, epoxy resin and polyester, among them, polyurethane The molding release of foam plastics occupies the vast majority, usually using a solution with a concentration of 0.5%-2.0% or an emulsion-type release agent, spraying it on a clean mold and drying it at the molding temperature for 30 minutes. Good release properties are obtained. If durable release properties are required, a curing release agent should be used. For the newly used mold, it is recommended to use a higher concentration of the release agent at the beginning to use it, and after adjusting for a period of time, the concentration of the release agent is lowered. For the release agent used in food packaging containers, an emulsion type release agent composed of a medium viscosity dimethicone and a food grade emulsifier is mainly used. For materials that are difficult to release, such as epoxy resins and polyurethanes, it is preferable to use a silicone oil-containing silicone oil or a fluorocarbon-based silicone oil as a release agent.




All of the above are described as being used as an external release agent. In recent years, the use as an internal mold release agent has been rapidly developed by directly adding a silicone oil to a thermoplastic resin or previously preparing a thermoplastic resin pellet containing a high concentration of silicone oil, and then mixing it into a master batch. For example, adding a small amount of silicone oil or silicone oil pellets to polystyrene, acrylonitrile butadiene styrene (ABS), polyolefin, nylon, polyoxymethylene, and polyvinyl chloride to improve fluidity and resin during extrusion molding. The amount of spit. In the injection molding, the recovery time of the screw can be shortened, the fluidity of the resin can be improved, the friction coefficient of the surface of the product can be reduced, and the wear resistance, lubricity, gloss and hydrophobicity of the product can be improved.


If dimethyl silicone oil is used, the viscosity is higher, such as 12500cs; when methyl phenyl silicone oil is added, the refractive index can be adjusted to obtain a transparent product; when polyether silicone oil is added, antistatic property can be imparted. The thin product has anti-adhesive property; when the long-chain alkyl silicone oil is added, the obtained product has post-processability such as printing, coating and embossing, and introduces a multifunctional MQ active silicone resin, a hydroxyl group-containing silicone oil and a hard resin into the thermoplastic resin. Magnesium citrate and the like can also improve the flame retardancy of the product. In addition, in the polyurethane reaction injection molding, the addition of carboxyhydrocarbyl silicone oil or NaO(Me2SiO)nNa as the internal release agent can avoid the use of the external release agent, and the product obtained by the former has good adhesion to the water-based ink. Sex.