MS2A
Description
[Linden Nazareth] A brand name for a polycyclohexanol resin made from MS2 polycyclohexanone resin. MS2A was first developed in the late 1950s at the suggestion of Garry Thomson (The National Gallery, London) and sold by Howards of Ilford in England in 1961. It was prepared by treating MS2 resin with sodium borohydride to reduce the carbonyls to hydroxyl groups. The polycyclohexanol resin (MS2A) exhibited less brittleness, yellowing and oxidation than the polycyclohexanone resin (MS2). MS2A was used as a varnish for paintings. In 1962 the process for making MS2 was changed to incorporate formaldehyde, thus making it unsuitable for conservation. MS2B was introduced in 1963; it was made by the same reduction process but used AW-2 [BASF] as a starting material. MS2B was discontinued in 1967 when BASF drop AW-2 as a product. In 1967 Howard's once again started producing MS2A from its original process. However, in 1973, Howards was acquired by Laporte Industries the manufacturing of MS2A was discontinued. Stockpiled MS2A was used as a varnish for about 10 years, then in 1984 Laporte resumed production. In 1993, the processing plant and production rights of MS2A were purchased by Linden Chemicals.
Risks
- Ingestion may be harmful.
- Skin contact may cause irritation.
Physical and Chemical Properties
- Soluble in petroleum hydrocarbons, turpentine, isopropanol.
- Insoluble in water, acetone.
- Tg = 57 C
- Refractive Index = 1.505
Resources and Citations
- V. Routledge (Linden Nazareth) "MS2A Resin - The History of its Development" Conservation News, No. 70, November 1999.
- S.Fisher, "Ketone Resin Varnishes: MS2A", AIC Painting Conservation Catalog: Varnishes and Surface Coatings, p.81, 1998.
- 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.
- 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