Dehydrated Castor Oil Fatty Acid commonly known as DCOFA is a high diene Fatty Acid based on Castor Oil. Three types of DCOFA are offered depending on the conjugation (low, medium and high). DCOFA is liquid at room temperature, having a water-white to pale yellow colour. Dehydration of Castor Oil is carried out at about 2500C in the presence of catalysts (e.g., Concentrated Sulphuric Acid, Activated Earth) and under an inert atmosphere or vacuum. Under this condition of dehydration, the Hydroxyl Group and adjacent Hydrogen Atom from the C-11 or C-13 position of the Ricinoleic Acid portion of the molecule is removed as water. This yields a mixture of two acids, each containing two double bonds but in one case, they are conjugated.
|refractive index at 250C||1,473-1,477||1,473-1,477||1,473-1,477|
|specific gravity at 250C||0,903-0,905||0,903-0,905||0,903-0,905|
|colour Regular||Gardner||max. 2||max. 2||max. 2|
|colour Special||Gardner||max. 1||max. 1||max. 1|
|iodine value||min. 130||min. 130||min. 130|
|hydroxyl value||max. 5||max. 5||max. 5|
|linoleic acid (non-conjugated)||%||45-55%||30-45%||25-30%|
|linoleic acid (conjugated)||%||35-45%||45-60%||60-66%|
|total Linoleic acid||%||88-95%||88-95%||88-95%|
|linolenic acid||%||max. 0,5%||max. 0,5%||max. 0,5%|
|conjugation by UV spectrometer (factor 0,91)||min. 30||min. 40||min. 50|
Dehydrated castor oil fatty acid based alkyd resins and polyamides make up superior constituent in numerous paint and printing inks formulations. Styrenated epoxy esters of these fatty acids are used in prime quality automotive paints.
DCOFA is also used in the manufacture of high solid alkyds, acrylic and epoxy ester resins, which are useful for interior and exterior can coatings, appliance finishes, automotive topcoats, primers, coil coatings, tube coatings, marine finishes, overprint varnishes and high-speed printing inks. Furthermore DCOFA can be used as chemical intermediate because of their conjugate dienes structure.
Used in High speed printing Inks, over Paint varnishes, Containers for food and beverages( Interior/Exterior) , Maintenance primers and top coats, Marine finishes, Tube coating, Automotive, primer and finish coat, Appliance and product finishes & coil coatings.