A synthetic polymer composed polymerized cyclohexanone and/or methyl cyclohexanone. Polycyclohexanones, or ketone resins, were first patented in 1930 by BASF. They are soluble in turpentine and form a clear, colorless coating. Polycyclohexanones form a film that is harder with less wrinkling, yellowing and blooming than dammar. Ketone resins have a relative low molecular weight (400-500) for a polymer and a high refractive index (~1.53) Because polycyclohexanone coatings are hard and brittle, however, many formulations add a plasticizer for flexibility and many of the plasticizers tend to yellow. Ketone resins have been used for picture varnishes and for retouching. They oxidize with age to become brittle and less soluble.
Synonyms and Related Terms
ketone resin; policiclohexano (Esp.); policicloesanone (It.); policiclohexano (Port.)
Examples: MS2 [Linden Nazareth]; AW-2 [BASF]; Ketone Resin N [BASF]; Laropal K 80; Rembrandt Varnish[Talens];
Physical and Chemical Properties
Soluble in turpentine, mineral spirit.
Resources and Citations
- R.de la Rie, A. Shedrinsky, "The Chemistry of Ketone Resins and the Synthesis of a Derivative with Increased Stability and Flexibility" Studies in Conservation, 34:9-19, 1989.
- Hermann Kuhn, Conservation and Restoration of Works of Art and Antiquities, Butterworths, London, 1986
- Kurt Wehlte, The Materials and Techniques of Painting, Van Nostrand Reinhold Co., New York, 1975
- Paintings Specialty Group, Painting Conservation Catalog, Wendy Samet (ed.), AIC, Washington, DC, 1998