HEC for coatings

HEC (hydroxyethyl cellulose) is a nonionic cellulose ether widely used in the coatings industry. Its functions include thickening, dispersing, suspending and stabilizing, which can improve the construction performance and film-forming effect of coatings. HEC is particularly widely used in water-based coatings because it has good water solubility and chemical stability.

1. Mechanism of action of HEC

Thickening effect

One of the main functions of HEC in coatings is thickening. By increasing the viscosity of the coating system, the coating’s coating and leveling properties can be improved, the sagging phenomenon can be reduced, and the coating can form a uniform covering layer on the wall or other surfaces. In addition, HEC has a strong thickening ability, so it can achieve an ideal thickening effect even with a small amount of addition, and has high economic efficiency.

Suspension and stabilization

In the coating system, solid particles such as pigments and fillers need to be evenly dispersed in the base material, otherwise it will affect the appearance and performance of the coating. HEC can effectively maintain the uniform distribution of solid particles, prevent precipitation, and keep the coating stable during storage. This suspension effect allows the coating to return to a uniform state after long-term storage, reducing stratification and precipitation.

Water retention

HEC can help the water in the paint to be released slowly during the painting process, thereby extending the drying time of the paint and enabling it to be fully leveled and film-formed on the wall. This water retention performance is particularly important for the construction effect, especially in hot or dry construction environments, HEC can significantly reduce the problem of poor film formation caused by too fast water volatilization.

Rheological regulation

The rheological properties of the paint directly affect the feel and film quality of the construction. The solution formed by HEC after dissolving in water has pseudoplasticity, that is, the viscosity decreases under high shear force (such as brushing and rolling), which is easy to brush; but the viscosity recovers under low shear force, which can reduce sagging. This not only facilitates construction, but also ensures the uniformity and thickness of the coating.

2. Advantages of HEC

Good water solubility

HEC is a water-soluble polymer substance. The solution formed after dissolution is clear and transparent, and has no adverse effects on the water-based paint system. Its solubility also determines its ease of use in the paint system, and it can dissolve quickly without producing particles or agglomerates.

Chemical stability

As a non-ionic cellulose ether, HEC has good chemical stability and is not easily affected by factors such as pH, temperature, and metal ions. It can remain stable in strong acid and alkaline environments, so it can adapt to different types of coating systems.

Environmental protection

With the improvement of environmental awareness, low VOC (volatile organic compound) coatings are becoming more and more popular. HEC is non-toxic, harmless, does not contain organic solvents, and meets environmental protection requirements, so it has a wide range of application prospects in water-based environmentally friendly coatings.

3. The effect of HEC in practical applications

Interior wall coatings

In interior wall coatings, HEC as a thickener and rheology modifier can improve the construction performance of the coating, giving it good leveling and adhesion. In addition, due to its excellent water retention, HEC can prevent cracks or powdering of interior wall coatings during the drying process.

Exterior wall coatings

Exterior wall coatings need to have excellent weather resistance and water resistance. HEC can not only improve the water retention and rheology of the coating, but also enhance the anti-sagging property of the coating, so that the coating can better resist wind and rain after construction and extend its service life.

Latex paint

In latex paint, HEC can not only act as a thickener, but also improve the fineness of the paint and make the coating film smoother. At the same time, HEC can prevent the precipitation of pigments, improve the storage stability of the paint, and make the latex paint stable after long-term storage.

IV. Precautions for adding and using HEC

Dissolution method

HEC is usually added to the paint in powder form. When using, it needs to be gradually added to the water and fully stirred to dissolve it evenly. If the dissolution is not sufficient, granular substances may appear, affecting the appearance quality of the paint.

Dosage control

The amount of HEC needs to be adjusted according to the formula of the paint and the required thickening effect. The general addition amount is 0.3%-1.0% of the total amount. Excessive addition will cause the viscosity of the paint to be too high, affecting the construction performance; insufficient addition will cause problems such as sagging and insufficient hiding power.

Compatibility with other ingredients

When using HEC, pay attention to compatibility with other paint ingredients, especially pigments, fillers, etc. In different paint systems, the type or amount of HEC may need to be adjusted to avoid adverse reactions.

HEC plays an important role in the coating industry, especially in water-based coatings. It can improve the workability, film-forming properties and storage stability of coatings, and has good chemical stability and environmental protection. As a cost-effective thickener and rheology modifier, HEC is widely used in interior wall coatings, exterior wall coatings and latex paints. In practical applications, through reasonable dosage control and correct dissolution methods, HEC can provide ideal thickening and stabilization effects for coatings and improve the overall performance of coatings.