Focus on Cellulose ethers

Paint grade HEC

Paint grade HEC

Paint grade HEC Hydroxyethyl cellulose is a kind of non-ionic water-soluble polymer, white or yellowish powder, easy to flow, odorless and tasteless, can dissolve in both cold and hot water, and the dissolution rate increases with temperature, generally insoluble in most organic solvents. It has good PH stability and little viscosity change in the range of ph2-12. HEC has high salt resistance and hygroscopic ability, and has strong hydrophilic water retention. Its aqueous solution has surface activity and high viscosity products have high pseudoplasticity. Can be made into anhydrous transparent film with moderate strength, not easily contaminated by oil, not affected by light, still has HEC water-soluble film. After surface treatment, HEC disperses and does not unite in water, but dissolves slowly. The PH can be adjusted to 8-10 and quickly dissolves.

 

The main properties

Hydroxyethyl cellulose(HEC) are that it can be dissolved in cold water and hot water, and has no gel characteristics. It has a wide range of substitution, solubility and viscosity. It has good thermal stability (below 140°C) and does not produce under acidic conditions. precipitation. The hydroxyethyl cellulose(HEC) solution can form a transparent film, which has non-ionic features that do not interact with ions and have good compatibility.

As a protective colloid, Paint grade HEC can be used for vinyl acetate emulsion polymerization to improve the stability of the polymerization system in a wide PH range. In the manufacture of finished products to make pigment, filler and other additives evenly dispersed, stable and provide thickening effect. It can also be used for styrene, acrylic, acrylic and other suspended polymers as dispersants, used in latex paint can significantly improve the thickening, improve leveling performance.

 

Chemcial Specification

Appearance  White to off-white powder
Particle size 98% pass 100 mesh 
Molar substituting on degree (MS) 1.8~2.5
Residue on ignition (%) ≤0.5
pH value 5.0~8.0
Moisture (%) ≤5.0   

 

Products Grades 

HEC grade Viscosity

(NDJ, mPa.s, 2%)

Viscosity

(Brookfield, mPa.s, 1%)

HEC HS300 240-360 240-360
HEC HS6000 4800-7200  
HEC HS30000 24000-36000 1500-2500
HEC HS60000 48000-72000 2400-3600
HEC HS100000 80000-120000 4000-6000
HEC HS150000 120000-180000 7000min

 

Application method of hydroxyethyl cellulose HEC in waterborne paint

1. Add directly when grinding pigment: this method is the simplest, and the time used is short. The detailed steps are as follows:

(1) Add appropriate purified water into the VAT of the high cutting agitator (generally, ethylene glycol, wetting agent and film forming agent are added at this time)

(2) Start stirring at low speed and slowly add hydroxyethyl cellulose

(3) Continue to stir until all particles are soaked

(4) add mildew inhibitor, PH regulator, etc

(5) Stir until all hydroxyethyl cellulose is completely dissolved (the viscosity of the solution is significantly increased) before adding other components in the formula, and grind until it becomes paint.

2. equipped with mother liquid waiting: this method is first equipped with a higher concentration of mother liquid, and then add latex paint, the advantage of this method is greater flexibility, can be directly added to paint finished products, but must be appropriate storage. Steps and methods are similar to steps (1) – (4) in Method 1, except that a high cutting agitator is not required and only some agitator with sufficient power to keep the hydroxyethyl fibers evenly dispersed in the solution is sufficient. Continue stirring until it completely dissolves into a thick solution. Note that the mildew inhibitor must be added to the mother liquor as soon as possible.

3. Porridge like phenology: Since organic solvents are bad solvents for hydroxyethyl cellulose, these organic solvents can be equipped with porridge. The most commonly used organic solvents such as ethylene glycol, propylene glycol, and film forming agents (such as hexadecanol or diethylene glycol butyl acetate), ice water is also a poor solvent, so ice water is often used with organic liquids in porridge. Gruel – like hydroxyethyl cellulose can be directly added to the paint. Hydroxyethyl cellulose has been saturated in porridge form. After adding lacquer, dissolve immediately and have thickening effect. After adding, continue to stir until hydroxyethyl cellulose completely dissolved and uniform. A typical porridge is made by mixing six parts of organic solvent or ice water with one part of hydroxyethyl cellulose. After about 5-30 minutes, the Paint grade HEC hydrolyzes and visibly rises. In summer, the humidity of water is too high to be used for porridge.

4 .Matters needing attention when equipping hydroxyethyl cellulose mother liquor:

 

Precautions

1 Before and after adding Paint grade HEC, must be stirred continuously until the solution is completely transparent and clear.

2. Sieve the hydroxyethyl cellulose into the mixing tank slowly. Do not add it into the mixing tank in large quantities or directly into the bulk or spherical Paint grade HEC.

3 water temperature and pH value of water have obvious relation to the dissolution of Paint grade HEC hydroxyethyl cellulose, so special attention should be paid to it.

Do not add some basic substance to the mixture before the Paint grade HEC hydroxyethyl cellulose powder is soaked with water. Raising the pH after soaking helps dissolve.

5 .As far as possible, early addition of mildew inhibitor.

6 When using high viscosity Paint grade HEC, the concentration of mother liquor should not be higher than 2.5-3% (by weight), otherwise the mother liquor is difficult to operate.

 

Factors affecting the viscosity of latex paint

1.The more residual air bubbles in the paint, the higher the viscosity.

2.Is the amount of activator and water in the paint formula consistent?

3 in the synthesis of latex, residual catalyst oxide content of the amount.

4. The dosage of other natural thickeners in the paint formula and the dosage ratio with Paint grade HEC.)

5.in the process of making paint, the order of steps to add thickener is appropriate.

6.Due to excessive agitation and excessive humidity during dispersion.

7.Microbial erosion of thickener.

 

Packaging: 

25kg paper bags inner with PE bags.

20’FCL load 12ton with pallet

40’FCL load 24ton with pallet

 


Post time: Nov-26-2023
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