Dehydrated Castor Oil (DCO)

Dehydrated castor oil (DCO)


Non-drying castor oil is converted into a drying oil when the hydroxyl group and adjacent hydrogen are removed from each ricinoleic acid chain. An additional double bond is created, resulting in two double bonds on each chain. The result of this process is a light colored, odorless, drying oil known as dehydrated castor oil.Dehydrated castor oil is a castor oil from which approximately 5% of the chemically combined water has been removed. Heating the oil in the presence of catalysts such as clays and metal oxides, phosphoric acid, and sulfuric acid, is where dehydration is carried out Main fatty acid composition of DCO is octa decadienoic acid. The most characteristic aspect is it contains conjugated linoleic acid .Therefore it has drying properties similar to those of Tung oil. DCO dries quicker than linseed oil. Paints incorporating DCO is superior in non-yellowing property, adhesion to metals, chemical resistance, water-proof, flexibility, hardness and gloss.DCO can be converted to dehydrated castor fatty acid by hydrolysis and distillation. This (dehydrated castor fatty acid) is used in the manufacture of alkyd resins, coatings, appliance finishes, primers and inks.

In commercial manufacture of dehydrated castor oil, the aim is to produce the most valuable material for use as a drying oil. Dehydrated castor oil is now recognized as an individual drying oil with its own characteristic properties and advantages. The drying oils owe their value as raw materials for decorative and protective coatings to their ability to polymerize or "dry" after they have been applied to a surface to form tough, adherent, impervious, and abrasion resistance films. The advantages claimed in surface coating applications include excellent odor and heat bleachability, good drying properties, more uniform polymer structure, and lack of after-yellowing.

ParametersDehydrated Castor Oil (D.C.O.)DCO Stand Oil
AppearanceReddish yellow Clear, liquid.Pale yellow Clear, liquidPale yellow Clear, liquidYellowish, Viscous, Clear liquid.
Relative density 
@ 30?C
Refractive index 
@ 40?C
Refractive index 
@ 20?C
Viscosity on Brookfeild 
@ 20? C
1.8-2.0 Poise1.7-2.0 Poise1.6-1.9 Poise10-250 Poise
viscosity (25?C) 1,6 - 2,8 1,6 - 2,8 1,6 - 2,8
Viscosity (Gardner scale) G ? I G ? I G ? I
Acid value6.00 Max.5.00 Max.4.00 Max.25.00 Max.
Iodine value(Wijs)127 Min.127 Min.128 Min.100-200
Hydroxyl value?? mg KOH/g25 Max.23 Max.22 Max.15.00 Max.
Saponification value mg KOH/g192-200192-200192-200192-200
specific gravity (15?C) 0,982 - 0,933 0,982-0,933 0,982 -0,933
Color, Gardner8 G Max.7 G Max.4 G Max.8 G Max.
Color, Lovibond 1?cell (Y+5R)40 Unit Max.15 Unit Max.10 Unit Max10 Max.
Uses & Applications

As superior drying oils the Dehydrated Castor Oil (D.C.O.) may be used as primary binders to upgrade house paints, enamels, caulks, sealants and inks. In cooked varnishes they combine with all the Basic resins, Rosin, Rosin-esters, Hydrocarbons and phenolic to produce clear varnishes and vehicles for pigmented coatings. In Varnishes, Alkyds and complex copolymers they provide impart resistance, Flexibility, Gloss, Chemical resistance, Adhesion, Flow and leveling.

The major applications are in high quality durable vehicles. These include Corrosion resistant coating, Traffic paints, Wire enamels, Can coating, Aluminum paints, Primers and application finishes.

D.C.O. Stand oil blended with hydrocarbon or phenolic resins produce excellent vehicle for aluminum pigments. Topcoats and primers have demonstrated superior weathering, water resistance and anti-corrosive properties. Storage test on paint prepared from these vehicles have shown excellent retention of leafing properties and no viscosity change after one year.

D.C.O. Stand oil is also used to modify alkyds. It is used in the preparation of alkyd resins to increase the oil length. Alkyds prepared with copolymer D.C.O. Stand oil impart batter flexibility, impact resistance toughness without adversely affecting water and chemical resistance.

Different grades of DCO are available on request

Blown castor oil is supplied in

  • Dehydrated castor oil is supplied in
  • Drums (190 kg)/Flexi Tanks/Steel Closed head drums
  • Bulk (ISO containers)
  • DCO is made into varnish, alkyd resin or styrene oil, and so forth. to be used in synthetic resin coatings and printing inks production.
  • DCO is made through thermal polymerization and its viscosity is higher than DCO. It is less likely to be gelated during varnish-cooking. Further, it can be cold-cut thus
  • the production control of varnish become much easier.
  • DCO is suitable for white or light color quick-drying enamel, super varnish, insulation varnish, printing inks, caulking and processing material for reinforcing steel.
  • DCO is also used to obtain fast kettling rate which gives lighter color and lower acid varnishes.
  • DCO is used with phenolics to obtain fast drying coatings with maximum alkali resistance as required in sanitary can lining, corrosion resistant coatings, traffic paints,
  • varnishes, ink vehicles, wire enamels, aluminium paint appliance finishes and marine finishes.
  • DCO is a very suitable and even better substitute for Linseed oil. Paints with DCO are super white and offer superior finish
  • Dehydrated castor oil is used as a primary binder for house paints, enamels, caulks, sealants and inks
  • In "cooked" varnishes it is combined with all the basic resins, rosins, rosin-esters, hydrocarbons and phenolics to produce clear varnishes and vehicles for pigmented coatings
  • DCO is also used in the manufacturing of lithographic inks, linoleum, putty and phenolic resins.Short ,Medium and long alkyd resin, Fatty acid manufacturing, malenised oils
  • It is used as a Drying Oil extensively in paints and varnishes
  • Used as Viscosity Modifier in Sealants, Adhesives and Paints;
  • Ingredient in Alkyd Resins Used in Anti-corrosive Coatings and Fast Drying Metal Primers and Topcoats
  • By far the most important coatings use of castor oil is in the form of dehydrated castor.
  • Alkyd resins in turn are used for paints, enamels, lacquers and varnishes with high gloss, good adhesion and wetting qualities.
  • The vulcanization of DCO with sulphur has been reported: factice, the resulting product, has been found to be a rubber additive with antiozonant and good flow properties.
  • If DCO is epoxidized, the product can be evaluated in poly (vinyl) compounds as a plasticizer/stabilizer, giving rise to the possibility that epoxidized castor oil may be capable of replacing epoxidized soybean oil.
  • DCO can be used to improve the quality of house paints, enamels, caulks, sealants and inks. It is used as primary binder for house paints, enamels, caulk sealant, and making varnishes.
  • This oil also works well in clear varnishes and hard finish coatings.
  • DCO is a very suitable for Linseed oil.