Hydrogenated castor oil is a waxy solid prepared by hydrogenation of castor oil. After treatment, it can be used as thixotropic agent of coatings, mainly used for thickening, anti-settling and anti-sagging.

It is 12- hydroxystearate triglyceride, and the fatty acid chain has hydroxyl groups, so it shows a certain degree of polarity.

It can swell and gel in nonpolar solvents, and due to the polar groups in hydrogenated castor oil molecules, weak hydrogen bonding occurs between swollen particles, forming a thixotropic network structure, improving pigment suspension, controlling sag without sacrificing fluidity and leveling, usually not reacting with other components of the coating, having no adverse effect on the durability of the coating, not yellowing in the formula, and providing storage stability and reproducibility.

Hydrogenated castor oil also needs activation treatment when it is used.

The activation process and mechanism are shown in 5-2.

In the activated 1 stage, hydrogenated castor oil rheological agent powder is first dispersed with basic material solution. In the second stage of activation, the temperature of the base material solution-hydrogenated castor oil powder mixture is raised to 43-53℃ under the condition of stirring, and the process needs to last for 20-30 minutes to fully swell the particles.

And then cooled to normal temperature under stirring to obtain a rheological structure with stable thixotropy.

In the process of activation, temperature control is very important.

If the maximum activation temperature is exceeded and the stirring is insufficient during cooling, hydrogenated castor oil will not form a thixotropic gel network and will precipitate "particles".

Similarly, the activation temperature is low and the activation duration is not enough, which will also happen.

When the "grain" is not well activated, it can be reactivated by the correct activation method.