The development of the use of cashew nut shell liquid (CNSL) in commerce can be traced from Cardolite Corporation to its predecessors 3M Company and Irvington Varnish and Insulator Company.
Dr. M. T. Harvey through his research company, Harvel Corporation, imported the first commercial quantity of CNSL in 1926 in the United States. CNSL was known for centuries prior to this, but no significant commercial uses had been developed. Dr. Harvey recognized that the unique chemical structure (a meta substituted alkenyl phenol) should have commercial use.
Harvel entered into a joint venture with Irvington Varnish and Insulator Company for the purpose of developing commercial uses of CNSL. Irvington and Harvel in the 1930’s developed the first major (and still the largest) use of CNSL which is cashew friction particle in the brake lining industry. Other uses into coatings were developed using its phenolic nature and its properties as a drying oil, but none were long lasting. However, in 1946 the business was large enough to justify construction of a dedicated factory to the production of derivatives of CNSL in Newark, New Jersey.
3M Company acquired Irvington in 1953. About this time, commercial production of cardanol began at Newark. Now, whole new families of products were possible. Cardolite NC-510, n pentadecylphenol, found use as an intermediate in color film. In 1954, 3M developed the monoglycidyl ether of cardanol (Cardolite NC-513). By the late 50’s, NC-513, especially, found extensive use in epoxy chemistry, and its use continues to this day. Liquid cashew resins were introduced as binders in automotive strip linings. In the 1970’s, 3M developed amine functional curing agents based on CNSL and gave them the generic name "phenalkamines."
In 1985, the CNSL business and the Newark plant were acquired from 3M by a management buyout led by Anthony Stonis, the company's current chairman. The new corporation was named "Cardolite" from the Irvington trade name. By this time phenalkamines had shown great promise in the heavy duty coatings market because of all season cure, good adhesion to poorly prepared surfaces, and good corrosion resistance. Cardolite and its few key customers pioneered the growth of phenalkamines in the late 80’s and early 90’s.
Cardolite Corporation continues to focus on advancing the use of CNSL in epoxy coatings, friction materials, and other select applications. Cardolite is, by far, the world's largest cardanol producer. Newer phenalkamines and phenalkamides have been developed which preserve the properties of previous generation products but have lower viscosities and lighter colors. Other new raw materials from CNSL are coming that will aid formulators to meet the demands of their next generation products.