Introduction
When choosing a coating for industrial or decorative purposes, one of the first decisions is whether to use water-based or solvent-based coatings. This article explains the differences between the two, compares their ingredients and additives, and explores best practices for formulation with key additives like HEC and HPMC.
What Are Water-Based Coatings?
Definition:
Water-based coatings use water as the main solvent or dispersion medium. The resin system exists in emulsion or water-soluble form.
Key Features:
Low VOC emissions
Non-toxic, ideal for indoor use
Slower drying time
Moderate chemical resistance (can be improved with additives)
What Are Solvent-Based Coatings?
Definition:
Solvent-based coatings use organic solvents like toluene, xylene, or acetone to dissolve the resin.
Key Features:
High VOC emissions
Fast drying time
Excellent adhesion and gloss
Flammable—requires proper ventilation
Additives Used in Water-Based Paints
| Additive Type | Function | Examples |
|---|---|---|
| Thickeners (core) | Adjust viscosity and stability | Celopro HHB30S |
| Wetting Agents | Improve substrate coverage | Alkynediols;Surfynol 104, fluorocarbon-based |
| Defoamers | Prevent bubble formation | Mineral oil-silicone composites: BYK-024, polyether siloxanes |
| Film-Forming Agents | Help coalescence and film formation | Texanol, PPH |
| pH Regulators | Maintain formulation stability | AMP-95(2-amino-2-methyl-1-propanol) |
| Preservatives | Prevent microbial contamination | Isothiazolinones: Kathon LX |
| Flash Rust Inhibitors | Protect metal surfaces | Organic amine-based alternatives |
Additives Used in Solvent-Based Paints
| Additive Type | Function | Examples |
|---|---|---|
| Leveling Agents | Enhance gloss and surface appearance | Silicones: BYK-306, acrylate-based |
| Defoamers | Eliminate foam during mixing or spraying | Mineral oil-based: BYK-066, polyether-modified siloxanes |
| Curing Agents | Enable cross-linking in 2K systems | HDI, amines curing agent |
| Dispersants | Prevent pigment settling | EFKA-5065, polymer dispersants |
| UV Absorbers | Improve outdoor durability | Benzotriazoles: Tinuvin 1130 |
Application Fields
Water-Based Coatings:
Home interiors (walls, ceilings, wood)
Exterior building walls
Furniture
Automotive interiors
Solvent-Based Coatings:
Aerospace & marine equipment
Metal anti-corrosion systems
Automotive exteriors
Industrial wood coatings
Choosing the Right Thickener: HEC vs. HPMC
HEC (Hydroxyethyl Cellulose)
As a leading HEC supplier in China, Celotech provides high-performance hydroxyethyl cellulose products tailored for a wide range of architectural and industrial coatings.
Key Benefits:
Offers excellent water retention, pseudoplastic behavior
Enhances open time and workability
Compatible with most waterborne resin systems
Recommended Grades:
Celopro HHB30S: Ideal for emulsion paints, offers cost-effective replacement for Natrosol 250HBR
Celopro HHB70S: Delivers higher viscosity with excellent biological stability, recommended in humid climates
HPMC (Hydroxypropyl Methyl Cellulose)
As a trusted China HPMC manufacturer, we specialize in cellulose ethers engineered for superior salt tolerance, splash resistance, and workability in advanced coating formulations.
Celopro MK50MSL:
Medium viscosity HPMC, suitable for short-term storage exterior coatings (shelf life <4 months)
Designed for anti-corrosion coatings, manual putty applications
Performs well in high-salt or alkaline environments
Conclusion & Market Trends
With increasing demand for sustainability and VOC compliance, choosing a reliable HEC supplier or HPMC manufacturer is crucial for developing next-generation coatings.
Celotech’s Celopro® series is engineered to support this transition by offering tailor-made thickening solutions for both water-based and solvent-based paints.
Frequently Asked Questions (FAQ)
Q1: Are water-based coatings always better than solvent-based?
Not necessarily. Water-based coatings are better for indoor and eco-sensitive environments, but solvent-based coatings still outperform in extreme industrial applications.
Q2: What is the biggest challenge with water-based paints?
Drying time and chemical resistance. However, these can be improved through additives and formulation optimization.
Q3: How do I choose between HEC and HPMC in water-based coatings?
The choice depends on your formulation requirements, storage conditions, and cost sensitivity:
HEC (Hydroxyethyl Cellulose) is ideal when long-term storage stability and biological resistance (anti-microbial performance) are critical. It offers better enzyme resistance and long-term viscosity retention, making it suitable for paints stored in humid climates or with extended shelf life. However, HEC is more expensive.
HPMC (Hydroxypropyl Methyl Cellulose) is a cost-effective thickener commonly used in manual putty, low-cost paints, or formulations with shorter shelf life (<4 months). It provides decent workability and salt resistance but has poor anti-microbial stability, requiring preservatives or being used in disposable systems.
Q4: What regulations affect solvent-based coatings?
VOC content is strictly regulated in many regions (e.g., EU REACH, US EPA), driving a shift toward water-based or high-solid solvent systems.
Q5: Where can I find a reliable HPMC manufacturer for water-based coatings?
You can source HPMC from Celotech, a professional HPMC manufacturer with years of expertise in cellulose ether production for coatings, adhesives, and construction industries.