Glycol Ethers, High-Purity Solvents

Ethyl 3-Ethoxypropionate (EEP)

Ethyl 3-Ethoxypropionate (EEP), identified by CAS number 763-69-9, is a high-performance, slow-evaporating ether-ester solvent characterized by its linear molecular structure. It is increasingly favored in the specialty chemicals industry for its unique ability to combine the solvency power of both an ester and an ether group. EEP is a clear, colorless liquid with a mild, non-pungent odor, making it a preferred choice for applications where air quality and worker comfort are critical. Its primary function is to serve as a high-boiling retarder solvent that facilitates exceptional flow and leveling in coating systems. Due to its low surface tension and excellent solubility across a broad range of polymers—including acrylics, polyurethanes, and epoxies—it is indispensable in high-end automotive, industrial, and electronic applications. Furthermore, EEP is recognized for its favorable environmental and safety profile, as it is readily biodegradable and is not classified as a Hazardous Air Pollutant (HAP).

Attributes

Key Features and Benefits

Controlled Evaporation: The slow evaporation rate ensures superior film formation, preventing surface defects like “solvent pop” or “orange peel” in high-gloss coatings.
High Solvency Power: Effectively reduces the viscosity of high-solids resin systems, allowing for lower VOC formulations without compromising performance.
Low Surface Tension: Promotes excellent substrate wetting and pigment stabilization, which enhances adhesion and color uniformity.
Safety Profile: Offers a mild odor and low acute toxicity; it is non-HAP and is not listed under SARA Title III, Section 313.
Hydrolytic Stability: Exhibits high resistance to hydrolysis compared to other esters, ensuring shelf-life stability in various formulations.

Specifications

Technical Highlights

Chemical Formula: C₇H₁₄O₃ with a molecular weight of 146.18 g/mol.
Boiling Point: Approximately 170°C (338°F), contributing to its high-boiling characteristics and late-stage film integration.
Vapor Pressure: Extremely low at 0.7 mmHg at 20°C, which minimizes evaporative losses during the initial stages of application.
Flash Point: 58°C (136°F) via Closed Cup method, categorizing it as a combustible liquid for storage and transport.
Hansen Solubility Parameters: δ_d (15.5), δ_p (4.9), δ_h (6.6), indicating broad compatibility with polar and non-polar resin matrices.
Electrical Resistance: High electrical resistance, making it suitable for use in electrostatic spray applications.