Application of Coating Grade CMC

1. The application of coating grade CMC in conventional coatings

The macromolecular chains of CMC with hydroxyl groups are hydrated with water and entangled at the same time, thereby it can increase the viscosity of the water phase. It has good compatibility in water or organic solvents, and has good compatibility with pigments, which greatly improves the viscosity and rheology of coatings. It is often used as a thickener, dispersant and stabilizer in the coating industry. The specific effects of CMC in the application of water-soluble coatings are as follows:

1) Good water resistance and good durability of the coating film;

2) High coating film fullness, uniform coating film, high gloss can be obtained;

3) As a stabilizer, it can prevent the coating from separating due to rapid temperature changes;

4) As a protective colloid, it can maintain the stability of the coating system in a wide pH range;

5) Coating grade CMC is used as a thickener to make the coating uniform, reach the ideal storage and construction viscosity, and avoid serious delamination during the storage period;

6) It can improve the leveling of the coating, the splash resistance and sag resistance of the coating, then improves the construction performance of the coating;

7) It can make pigments, fillers and other additives uniformly dispersed in the paint, so that the paint has an excellent color adhesion effect.

It's recommended to choose reliable carboxymethyl cellulose manufacturers for cooperation.

2. The application of coating grade CMC in latex coatings

Latex coatings are mainly composed of water dispersions of polymers and water dispersions of pigments. Its viscosity affects pigment sedimentation, paintability, roll coating, film fullness, leveling and sagging on the vertical surface of the film. So it is often necessary to adjust the viscosity or rheology of latex coatings. In latex coatings, CMC has the characteristics of good fluidity, low brushing resistance and easy construction. It is used as a stabilizer, thickener for latex coatings and water retaining agent:

1) It has excellent thickening effect and high thickening efficiency for latex coatings;

2) It can make the paint have a certain viscosity, will not precipitate during storage, but has stability;

3) It can prevent moisture from entering the porous substrate quickly, so that the water retention requirement can be met when the content of the emulsion is high;

4) There are few restrictions on coating formulations, and it is less affected by latex types, dispersants and surfactants;

5) After the coating is completed, the destruction of the hydration between CMC and water is terminated, and the viscosity is restored to prevent sagging.

3. The application of coating-grade CMC in foundry coatings

CMC is a polymer compound, which is multi-chain. After being swelled with water, the linear chain opens, stretches, and interacts to form a network colloid. It can interact with the sodium bentonite, not only can effectively improve the suspension capacity of the sodium bentonite, but also greatly reduce the volume of precipitation agglomeration and prevent the refractory powder from sinking. Therefore, it is often used to increase the suspension rate of the casting coating and improve the viscosity of the coating at the same time:

1) It has excellent water-soluble viscosity, which effectively improved the viscosity and rheology of the coating;

2) It has good solubility and dispersibility, so that solid substances are suspended in the carrier liquid;

3) It can promote the suspension of refractory powder to prevent precipitation, stratification and excessive infiltration of the carrier liquid into the modeling material;

4) It can improve the coating and covering ability of the paint, improve the brushability and leveling of the paint;

5) The powder in the coating is bonded to each other after drying, and firmly adheres to the surface of the mold and core.