Definition and measurement method
The solid content of silicone oil emulsion refers to the percentage of the mass of solid components such as silicone oil in the emulsion to the total mass of the emulsion. For example, a silicone oil emulsion with a solid content of 50% means that for every 100 grams of emulsion, 50 grams are silicone oil and other solid additives, and the other 50 grams are solvents such as water. It is usually measured by drying method, that is, a certain mass of emulsion is dried at a specific temperature, and the ratio of the mass of the remaining solid to the mass of the initial emulsion is the solid content.


Stability


High solid content emulsion:
The stability is relatively poor. Due to the high proportion of solid components, particles are more likely to collide and aggregate with each other. For example, when the solid content reaches more than 70%, the silicone oil particles in the emulsion are easily agglomerated during storage due to factors such as temperature changes and mechanical vibrations, resulting in emulsion stratification or demulsification.
Higher requirements for emulsifiers. More efficient emulsifiers are needed to prevent the aggregation of silicone oil particles, and the amount of emulsifier may also need to be appropriately increased to maintain the stability of the emulsion.


Low solid emulsion:
Better stability. Because of the small amount of solid components, the particles have a larger space in the emulsion and the probability of mutual collision is lower. For example, silicone oil emulsion with a solid content of about 30% can remain stable for a long time under normal storage and transportation conditions, and is not prone to stratification.


Application performance


High solid emulsion:
High application efficiency. It is more advantageous in occasions where a large amount of silicone oil components are required. For example, in the application of rubber release agents, high solid content silicone oil emulsions can form a thicker and more uniform silicone oil film on the rubber surface, with better demolding effect and can reduce the amount of emulsion used.
The drying speed may be slow. Due to the large amount of solid components, after application, the silicone oil layer left after the water evaporates is thicker. More time and energy are required during the drying process to solidify the silicone oil layer, so as to achieve the best application effect.


Low solid emulsion:
Wide application range. It is more suitable for occasions that do not require high silicone oil content but have high requirements for emulsion fluidity and uniformity. For example, in the dust and moisture-proof treatment of some precision electronic equipment, low-solid silicone oil emulsion can be evenly covered on the surface of electronic components, and the performance of electronic components will not be affected by excessive silicone oil.
Fast drying speed. Because the silicone oil layer left after the water evaporates is thin, it can dry in a shorter time to form a thin and uniform silicone oil protective film, which plays a good protective role.