What Is Butyl Acetate Solvent (CAS 123-86-4)?
Butyl acetate solvent, also called n-butyl acetate or acetic acid butyl ester, is a chemically active organic ester and one of the most widely used solvents in the paint industry. With CAS registry number 123-86-4 and molecular formula C6H12O2, it is a colourless or slightly yellow liquid with a pleasant fruity odour, and it is practically insoluble in water. It dissolves fats, cellulose esters, oils, vinyl intermediates, chlorinated rubber and carbinol resins, which makes it a versatile medium for coatings and for many other formulations.
Product Specifications and Quality Indexes
Commercial n-butyl acetate is supplied as a transparent liquid free of suspended impurities. Incoming inspection for solvent-grade material usually follows the quality indexes below.
| Parameter | Typical Value |
|---|---|
| n-Butyl acetate content | 99.5 % min |
| n-Butanol content | 0.2 % max |
| Water content | 0.05 % max |
| Acidity as acetic acid | 0.010 % max |
| Colour | 10 Hazen max, platinum-cobalt scale |
| Density at 20 °C | 0.878 - 0.883 g/cm3 |
| Appearance | Clear liquid, no suspended matter |
These tight limits keep evaporation behaviour, solvency and reproducibility stable in paint, adhesive and extraction processes. A certificate of analysis, a technical data sheet and a safety data sheet normally accompany each delivery so that the incoming material can be checked against the agreed specification before release to production.
Paints, Coatings and Lacquers
The most common industrial use of butyl acetate is as a solvent in the production of lacquers and paints. It dissolves film-forming resins and modifies viscosity and flow, helping coatings level smoothly and dry at a controlled rate. Its moderate evaporation speed makes it especially valuable in high-solids and industrial coating systems where film quality and defect-free application are required. The balanced evaporation profile also reduces blush and solvent popping in baked finishes.
Industrial and high-solids coatings
Nitrocellulose and cellulose ester lacquers
Wood and furniture finishes
Automotive refinish and primer systems
Adhesives, Artificial Leather and Printing Inks
Butyl acetate is also used in the manufacturing of artificial leather, plastic adhesives, hardened coatings and topcoats. In adhesive formulations it adjusts tack and open time, while in artificial leather production it helps dissolve the polymer systems used for surface layers. Printing ink producers rely on the solvent to control drying speed and pigment dispersion, and it is a standard component of many screen and gravure ink blends.
Pharmaceutical, Cosmetic and Other Applications
In the pharmaceutical industry, butyl acetate serves as a solvent or extraction agent for processing oils and coatings. It appears in lubricants, chemical intermediates, fruit flavouring systems and various additives. In cosmetics it functions as a flavouring solvent in perfumes, and it is found in fabric and leather treatment products, in cleaning and care products for vehicles, air and personal use, and as an anticorrosive agent. Smaller volumes are consumed as a reaction medium for esterification and as a carrier in speciality chemical synthesis.
Storage, Handling and Supply
Butyl acetate is a flammable liquid with a flash point near 22 °C, so it should be kept in closed containers away from heat, sparks, oxidisers and direct sunlight. Drums and intermediate bulk containers are the usual delivery formats for bulk solvent buyers, and mild steel, stainless steel or lined drums are widely accepted for transport and short-term storage. Adequate ventilation and suitable personal protective equipment are recommended wherever vapour concentrations may build up.
Frequently Asked Questions
Q: What is the CAS number of butyl acetate?
The CAS registry number of n-butyl acetate is 123-86-4.
Q: What is butyl acetate used for?
It is mainly used as a solvent in paints, lacquers and coatings, and in the production of adhesives, artificial leather, printing inks, pharmaceuticals, cosmetics and cleaning products.
Q: What is the minimum purity of commercial butyl acetate?
Commercial n-butyl acetate typically contains at least 99.5 % butyl acetate, with water content below 0.05 % and acidity below 0.010 %.
Q: Does butyl acetate dissolve in water?
Butyl acetate is practically insoluble in water, but it dissolves fats, cellulose esters, oils, vinyl intermediates, chlorinated rubber and carbinol resins well.
Q: Why is butyl acetate preferred in paints?
Its moderate evaporation rate, strong solvency and good levelling behaviour help coatings dry evenly without defects, which is why it is a standard solvent in industrial paints and lacquers.
Q: How should butyl acetate be stored?
Keep it in closed containers away from heat, sparks and oxidisers in a well-ventilated area, and consult the safety data sheet of the specific grade before bulk handling.