Sodium carboxymethyl cellulose is the most widely used and most used type of cellulose in the world.
Referred to as CMC-Na, it is a cellulose derivative with a glucose polymerization degree of 100-2000, and its relative molecular mass is 242.16. White fibrous or granulated powder. Odorless, hygroscopic, soluble in water, insoluble in ethanol, ether, and trimeric methane.
1. Apply in conventional coatings
Carboxymethyl Cellulose macromolecular chains with hydroxyl groups hydrate with water and produce entanglement, which increases the viscosity of the aqueous phase has good compatibility in water or organic solvents, and has good compatibility with pigments. Greatly improve the viscosity and rheology of coatings. It is often used as a thickener, dispersant and stabilizer in Coating Chemical. The specific effects of CMC in water-soluble coatings are as follows:
*Good water resistance and good durability of the coating film
*High film fullness, uniform coating, high gloss
* As a stabilizer to prevent the coating from separating due to sudden changes in temperature;
* As a protective colloid, it maintains the stability of the coating system over a wide pH range.
* As a thickener, the coating can be uniform, ideally preserved and applied, to avoid serious delamination during storage.
* Improve the leveling of the coating, improve the splash resistance and sag resistance of the coating, thereby improving the coating performance
* It can make pigments, fillers and other additives evenly dispersed in the coating, so that the coating has excellent pigment adhesion effect.
2. Application in latex coatings
Latex paint consists mainly of an aqueous dispersion of the polymer and the aqueous dispersion of the pigment, the viscosity of which is related to pigment settling, brushability, roll coating, film fullness, leveling and sag on the vertical surface of the film. It has an effect, so it is often necessary to adjust the viscosity or rheology of the latex paint. CMC has good fluidity in the latex paint, low brushing resistance, and easy construction. It is used as a stabilizer and thickener for latex paints. And water retention agent use:
*Excellent thickening effect, high thickening efficiency for latex coatings
* Can make the paint have a certain viscosity, do not precipitate during storage, and have stability
* Prevents moisture from entering the porous substrate quickly, so that the water content can meet the water retention requirements when the emulsion content is high
* Fewer restrictions on coating formulations, less affected by latex type, dispersant and surfactant
*Coating is completed, the destruction of water synthesis between CMC and water is terminated, and the viscosity is restored to prevent sagging
3. Apply in Building Coating Material
CMC is a polymer compound, which is multi-chain. After water swelling, the linear chain opens, stretches and interacts to form a network colloid. It can interact with sodium bentonite, which can not only effectively improve the suspension capacity of sodium bentonite, but also It can greatly reduce the volume of precipitated agglomerates and prevent the refractory powder from sinking, so it is often used to increase the suspension rate of foundry coatings while improving the viscosity of the coating:
* Excellent water solubility and viscosity, effectively improve coating viscosity and rheology
*Good solubility and dispersibility, suspending solid matter in the carrier liquid
* Promote suspension of refractory powder to prevent precipitation, delamination and excessive penetration of carrier liquid into molding materials
* Improve the coating and covering ability of the coating to improve the paintability and leveling of the coating
*The powder in the paint adheres to each other after drying and adheres firmly to the core and core surface.