Advantages and disadvantages of bentonite in coating applications

Bentonite [Basic Introduction]

The main mineral in bentonite is montmorillonite, and the basic structure of montmorillonite is TOT type, that is, two layers of silicon-oxygen tetrahedron sandwich a layer of aluminum-oxygen octahedron to form a layered structure

5 advantages of bentonite in coating applications

1.

2 Suspension and dispersibility: Bentonite has good suspension and dispersibility in water medium, which makes the coating not easy to settle, not easy to delaminate, and has a uniform color, thereby improving the stability of the coating suspension, and it has good brushing performance and can form Uniform thickness, flat and smooth coating

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4 major pitfalls in coating applications

01

For organobentonite, due to the different cationic organics introduced during modification, the adaptability of organobentonite to solvents is also different, resulting in some organobentonites destroying or interfering with hydrogen bonds in a highly polar solvent environment, causing the system to resist.

02

Bentonite is a powdery rheological additive, and it is difficult to add it, and it may be difficult to disperse.
Especially for small experiments in the laboratory, it is difficult to grasp the temperature and dispersion.
The measured data are: larger error
.

03

Bentonite has a great influence on the gloss of the coating film.
When the amount of bentonite reaches 20% of the total formula, the coating loses its gloss seriously, and the surface is dry, easy to crack and brittle
.

04

Bentonite has a low whiteness and has an adverse effect on the leveling of coatings
.

Summarize

Bentonite is mainly used as additives in coatings, such as thickeners, anti-settling agents, dispersants, etc.
Its addition amount is generally between 0.
2% and 2%, which has little effect on other properties of the coating.
Prevents sedimentation of pigments and fillers in coatings
.