Coating: Performance difference between liquid thickener and powder cellulose (mainly hydroxyethyl cellulose HEC) thickener
Firstly, it should be noted that the vast majority of powdered cellulose is hydroxyethyl cellulose (HEC), and water-based coatings are the most commonly used; The category of liquid thickeners is very wide, with three mainstream types: polyurethane associative thickeners (HEUR), acrylic acid alkali swelling thickeners (ASE/HASE), and liquid modified bentonite. Below, we will compare the differences in practical applications and explain the pain points related to storage, construction, paint film, and formula.
1、 Differences in thickening mechanisms (root cause differences)
1. Hydroxyethyl cellulose powder HEC (non-ionic cellulose)
By relying on a large number of hydroxyl groups in the molecular chain and hydrogen bonding with water molecules, a continuous hydration network structure is formed, which belongs to water phase thickening.
It is not affected by lotion particles, and the aqueous phase system is simply thickened.
2. Liquid thickener
ASE/HASE (Alkali Swelling Acrylic Acid): Under alkaline conditions, molecular chains stretch and the aqueous phase thickens;
HEUR (associative polyurethane): hydrophobic groups at both ends, lotion/pigments and fillers adsorbed at one end, and micelles associated at the other end, thickening the aqueous phase+building particle network structure (associative thickening);
Liquid bentonite: Sheet shaped chips are dispersed to form a card house structure.
Core distinction: HEC only thickens water; HEUR can connect solid particles in coatings.
2、 Comparison of Various Performance (General Reference for Waterborne Architectural Coatings)
1. Viscosity and rheology (the most important construction characteristics)
HEC cellulose powder
High and low shear viscosity (viscosity inside the tank): high static viscosity, excellent sedimentation prevention;
Rapid decrease in viscosity at medium to high shear rates: viscosity decreases during brush and roller coating, resulting in relatively better leveling, but weaker resistance to sagging;
Rheological characteristics: typical pseudoplasticity, no obvious binding effect;
Disadvantages: Viscosity is sensitive to temperature, and the system becomes noticeably thinner when heated.
Rapid decrease in viscosity at medium to high shear rates: viscosity decreases during brush and roller coating, resulting in relatively better leveling, but weaker resistance to sagging;
Rheological characteristics: typical pseudoplasticity, no obvious binding effect;
Disadvantages: Viscosity is sensitive to temperature, and the system becomes noticeably thinner when heated.
Liquid HEUR polyurethane thickener (the most mainstream liquid thickener on the market)
The improvement of low shear viscosity is limited, and the consistency in the same amount of addition tank is not as good as HEC;
Strong viscosity retention in medium shear → excellent resistance to sagging;
High shear viscosity: greater roller coating resistance, resulting in a “rough” texture;
Temperature stability is better than HEC.
Strong viscosity retention in medium shear → excellent resistance to sagging;
High shear viscosity: greater roller coating resistance, resulting in a “rough” texture;
Temperature stability is better than HEC.
Liquid ASE/HASE alkali swelling
The thickening efficiency inside the tank is very high, close to HEC, but it has poor water resistance and is sensitive to pH.
2. Water resistance, breathability, and paint film performance
HEC’s biggest weakness: excessive hydrophilic hydroxyl groups
After film formation, residual cellulose macromolecules remain inside the paint film, which is highly prone to water absorption: the water resistance and scrub resistance of the paint film decrease, making it prone to foaming and whitening;
2. Advantages: Better breathability, suitable for exterior wall breathable putty and breathable primer;
2. Advantages: Better breathability, suitable for exterior wall breathable putty and breathable primer;
Liquid HEUR polyurethane & ASE
Liquid HEUR polyurethane has multiple hydrophobic structures, which have a much smaller negative impact on the water resistance and scrub resistance of the paint film than HEC. It is the preferred choice for high-end interior and exterior wall coatings; ASE acrylic thickeners have more hydrophilic carboxyl groups and average water resistance.
3. Compatibility of formula, difficulty in foaming and defoaming
Powder HEC
Dissolving takes time, and poor dispersion can easily lead to clumping and fish eyes; The dissolution process is wrapped in air, which is prone to foaming, and the system is stable and strong, making defoaming difficult; Compatible with anionic dispersants as a whole.
Liquid HEUR
Liquid HEUR is a ready-made liquid that is easy to feed and has no risk of clumping; Stability of foam is lower than HEC; However, some models are greatly affected by surfactants and ethylene glycol, and excessive amounts can easily lead to loss of gloss and water separation.
Liquid ASE
Liquid ASE: sensitive to electrolytes and prone to viscosity collapse due to high salt content in the system.
4. Compatibility and color development of colorants
HEC: Simple water phase thickening results in stable pigment dispersion, but the color development is average and prone to floating and blooming;
· HEUR association thickening: it can absorb pigments and lotion, build a network, and has excellent color development and stronger anti floating ability;
Solid color topcoats pursue uniform color and are mostly used in HEUR compound.
5. Storage stability (anti settling)
Pure HEC system: low shear viscosity, high viscosity, titanium dioxide and heavy calcium are not easy to settle, excellent storage stability;
Pure HEUR system: Insufficient static low viscosity, heavy fillers are prone to layering and settling after long-term storage; HEC + HEUR
Compound, balancing storage anti sinking and construction anti sagging.
6. Resistant to microorganisms and mold (anti-corrosion inside the tank)
HEC belongs to natural modified polysaccharides and microbial carbon sources! Highly susceptible to bacterial degradation, viscosity decreases during long-term storage, and sufficient preservatives are necessary;
Synthetic liquid thickeners (HEUR, ASE) are artificially synthesized polymers that are not easily decomposed by microorganisms and have better long-term viscosity stability.
7. Convenience of use
Powdered cellulose: requires pre swelling and complex process; The operation of cold water soluble HEC is simplified, but the feeding speed still needs to be controlled to prevent agglomeration;
Liquid thickener: direct feeding and viscosity adjustment, simple production operation, and more friendly automated production line.
3、 Cost and Recommended Applicable Scenarios
1. Application scenarios of powdered hydroxyethyl cellulose (HEC)
Low cost interior wall putty, primer, and low-end interior wall coatings for engineering;
High filling system requires strong anti settlement measures;
It is not recommended to use it alone for high abrasion resistant facial wash paint and exterior wall topcoat (water resistance defects)
2. Applicable scenarios of liquid HEUR polyurethane thickener
High end interior wall paint, exterior wall elastic coating, water-based industrial topcoat;
Need excellent anti sagging, color development, and scrub resistant formula;
Insufficient anti settlement measures for single use, it is recommended to use a small amount of HEC/bentonite as an auxiliary
3. Liquid ASE/HASE
Mostly used for mid to low end interior walls and colorful protective adhesive systems, rarely used as a standalone topcoat for thickening.
4、 Summary of Common Formula Phenomena (Practical Problems)
1 Only use HEC: The can is very thick, and brushing thick can easily cause sagging; The paint film has poor scrub resistance and turns white when exposed to water; Easy to ferment and reduce viscosity; Foam;
2 Only use HEUR: The tank looks thin, but customers complain that it is too thin; Thick coating is not prone to sagging; Uniform color and better paint film performance; Long term storage of heavy calcium is prone to settling;
3 Industry standard combination: a small amount of HEC provides static anti settling and HEUR provides construction rheology and paint film performance
Supplement key misconceptions
Many people think that ‘liquid thickeners=polyurethane’, but that’s not true.
There are three types of liquid thickeners with significant performance differences:
Liquid HASE should not be directly compared with HEC, as HASE has poor water resistance and is sensitive to electrolytes; Only HEUR can replace/compound HEC for high-quality topcoats.
Post time: Jul-31-2026