CASHEW NUT SHELL LIQUID (CNSL)

CASHEW NUT SHELL LIQUID (CNSL) is a versatile raw material for the production of number of commercially important products specially for Surface Coatings because of its special composition. Considerable amount of work has been done with great success in various Research Laboratories and Industries both in India and Abroad for the preparation of Resins, Lacquers, Varnishes, Primers and Paints.

Products from CNSL

Polymerisation products

CNSL polymerises because of the unsaturation in the side chain of cardinal, when heated in the presence of some metals like copper, aluminium, lead or their oxides. This forms good media for paints when further cooked with drying oils.

Condensation products

Phenol Formaldehyde Resins of the Novolac or Resole types are well known. Similar reactions also take place with CNSL, but due to the presence of the long hydrocarbon chain the condensates are more flexible than the conventional Phenolic Resins. These resins can be used for Surface Coatings with or without oil modification when high chemical resistance is desired. CNSL Aldehyde condensation products have also been used for other purposes like insulating Varnishes, Moulding Powders, Brake Lining Compositions, etc.

Other Derivatives from CNSL

Other derivatives of CNSL are used in the preparation of surface-active agents by:

Sulfonation Antioxidants Lubricants Bactericides, Fungicides and Disinfactant Insecticides, Pesticides and Herbicides Drugs Dyestuff

Properties of CNSL

The physical and chemical characteristics of CNSL are as follows:

Appearance  Dark Brown Liquid Specific Gravity @ 30°C 0.92 – 0.96 Viscosity @ 30°C 50 – 200 cps Ash Content (%) 1% (Max.) Moisture Content 2% (Max.) Insolubles in Toluene (%) 1% (Max.) Acid Value (mgmKOH/gm) < 20 Hydroxyl Value (mgmKOH/gm) 170-250 Iodine Value (WIJS) 220 – 270 Saponification Value 18 – 30 Specification of CNSL IS-840 is the BIS specification for CNSL.