Application of hydroxyethyl cellulose in coatings

Paint, traditional Chinese name for paint. The so-call paint is coat on the surface of the object to be protect or decorate, and can form a continuous film that is firmly attache to the object to be coat. Today, I will talk with you about the role of common hydroxyethyl cellulose in coatings!

1.What is hydroxyethyl cellulose?

Hydroxyethyl cellulose (HEC), a white or pale yellow, odorless, non-toxic fibrous or powdery solid. It is prepare from alkaline cellulose and ethylene oxide (or chloroethanol) through etherification reaction, and belongs to nonionic soluble cellulose ethers.

Because HEC has good characteristics of thickening, suspending, dispersing, emulsifying, bonding, forming film, protecting moisture and providing protective colloid. Has been widely used in petroleum extraction, coatings, construction, medicine and food, textile, paper and polymer polymerization.

2. What will happen when hydroxyethyl cellulose meets water-based coatings?

Hydroxyethylcellulose acts as a non-ionic surfactant. In addition to thickening, suspending, bonding, floating, film-forming, dispersing, retaining water and providing protective colloid, it also has the following properties:

HEC can be dissolve in hot or cold water, and does not precipitate when heat or boil, making it have a wide range of solubility and viscosity characteristics, and non-thermogelability;

Water retention capacity is twice as high as that of methyl cellulose, and it has better flow regulation;

Compared with the recognized methyl cellulose and hydroxypropyl methyl cellulose, the dispersion ability of HEC is the worst, but it has the strongest protective colloid ability;

The non-ionic type can coexist with a wide range of other water-soluble polymers, surfactants and salts, and is an excellent colloidal thickener containing a high concentration of electrolyte solution.

3. How to use hydroxyethyl cellulose? How to add it?

Add directly in production-this method is the simplest and takes a short time.

Add purified water to a large bucket with a high shear mixer. Start stirring constantly at low speed and slowly sieve hydroxyethyl cellulose evenly into the solution. Continue stirring until all particles are wet.

Then add preservatives and various additives. Such as pigments, dispersion aids, ammonia, etc. Stir until all the hydroxyethyl cellulose is completely dissolve (the viscosity of the solution increases significantly) before adding the other components in the formula for reaction.

Equipped with mother liquor standby.

Is prepare with a higher concentration of mother liquor, and then add to the product. The advantage of this method is that it has greater flexibility and can be directly add to the finished product, but it must be properly store. This method step is similar to most steps in method one;

The difference is that there is no need for a high-resistance agitator, only a stirrer with sufficient power to keep the hydroxyethyl cellulose in the solution uniformly dispersed can be used. Continue stirring until completely dissolved into a viscous solution. However, it must be note that the antifungal must be add to the mother liquor as early as possible.

Tips

As the surface-treated hydroxyethyl cellulose is a powder or fibrous solid, when equipped with hydroxyethyl cellulose mother liquor, Shandong Heda reminds you to pay attention to the following points:

(1) Before and after adding hydroxyethyl cellulose, you must keep stirring until the solution is completely transparent and clear.
(2) Must be sift into the mixing tank slowly, and do not directly connect the mixing tank with lumps and spheres and hydroxyethyl cellulose.
(3) Water temperature and pH value in water have a clear relationship with the dissolution of hydroxyethyl cellulose,so special attention must be paid.
(4) Do not add some alkaline substances to the mixture before the hydroxyethyl cellulose powder is wet with water. Increasing the pH after soaking will help dissolve.
(5) As far as possible, add antifungal agent in advance.
(6) When using high-viscosity hydroxyethyl cellulose, the concentration of the mother liquor should not be higher than 2.5-3% (by weight), otherwise the mother liquor is difficult to handle.