Properties and Application of Silicone Resin Coatings


Silicone polycondensates have relatively stable Si-O-Si molecular structure similar to inorganic salts. Therefore, whether liquid, solid or elastomeric polymers, they have high thermal and chemical stability, excellent electrical insulation and excellent hydrophobicity.


High temperature resistance


Generally, the heat resistance of synthetic resin paint is below 150 C, while silicone paint can be used for a long time at 200 C. If high temperature pigments are added, the heat resistance can be up to 400 500 and the special temperature can also be up to 800 900. Therefore, it is suitable for coating high temperature resistant components.


Electrical performance and good hydrophobicity


Because the outer layer of silicone paint has a layer of non-polar organic genes and molecular symmetry, it has become the basic reason for its good electrical insulation and hydrophobicity. In terms of insulation, it not only has high insulation resistance, but also has excellent performances in breakdown amplitude and high voltage arc spark resistance, so it can be used to impregnate motor and parts with high insulation performance requirements to improve the insulation level of insulation components.


Silicone paint film immersed in water for 168 hours has a water absorption rate of about 0.2%. Therefore, silicone paint is suitable for high temperature and damp environment.


High surface activity and low tension


Because polysiloxane is a symmetrical molecule and its substituents are non-polar organic groups, the whole molecular formula is non-polar. The intermolecular force is small, and the cohesive force of the molecule is small. Therefore, the surface tension is small. When it is dispersed on the surface of the medium with larger surface tension, it can separate the medium, and because the force between the molecule itself and the medium is also small, it can reduce the surface tension of the medium and make it difficult to form foam. This is the reason why silicone oil can be used as defoamer in paint making. Therefore, it can be used as defoamer and leveling agent in paint mixing to prevent the film from glowing and pitting. The dosage is 0.2%-0.3%.


Good cold resistance


Due to the structure of the macromolecule itself, the attraction between the molecules is weak, which gives it good cold resistance. The cold resistance of pure silicone is about - 50 C, while that of polyester modified silicone paint W31 - 1 is below - 80 C. Therefore, this paint can be used in colder places.


Good chemical resistance


Due to the existence of ether bond in silicone paint, the inherent good performance of chemical resistance. For example, the paint film is immersed in 2% acetic acid: 10% hydrochloric acid, 10% nitric acid, 10% sulfuric acid, 10% caustic soda, 10% sodium nitride or butanol, kerosene. After 100 hours, the paint film is still good.


Good mildew resistance


Because the organic silicone paint does not contain oil, so mold can not survive on the organic silicone paint film, so the organic silicone paint has better anti-mildew performance, suitable for coating on parts required by special anti-mildew properties.


In short, because of the above-mentioned good performance, this kind of paint has become an indispensable coating for electrical appliances, instrumentation and national defense industries. It has been widely used in high-temperature resistant machinery and equipment (such as boilers, high-temperature reaction towers, sintering furnaces, etc.), H-grade insulation materials, long-term maintenance of outdoor equipment, chemical corrosion resistant equipment, etc. Aspect.


Construction Requirements of Silicone Resin Paint


1. The construction method of silicone resin paint can be dipped or sprayed. Generally, spraying is preferable for enamel and dipping is preferable for varnish.


2. Whether it is self-drying or drying organic silicone paint, when used, the properties of the paint which is generally baked have been improved. The general varnish is dried at 200 ~C for 2 hours and the enamel is dried at 150 ~C for 2 hours.


3. Dilutants are generally toluene or xylene. Sometimes they can be used to form mixed solvents with butanol, which depends on the type of silicone paint.


Source: Corin Silicon Material