Laropal K-80
Description
[BASF] A trademark for a Polycyclohexanone resin introduced in 1979 as a replacement for Ketone Resin N. Laropal K-80 is prepared by the polycondensation of cyclohexanone in a continuous process. Polycyclohexanones resemble Dammar in that they are soluble in turpentine and form a glossy, colorless coating. However, they are harder and exhibit less wrinkling, blooming, and yellowing than natural resins. Because polycyclohexanone coatings are hard, however, many formulations add a plasticizer for flexibility and many of the plasticizers tend to yellow. Additionally, polycyclohexanones oxidize, become brittle, and less soluble with age. They have been used for retouching and occasionally for picture varnishes.
Physical and Chemical Properties
Soluble in petroleum hydrocarbons, turpentine, isopropanol. Insoluble in water and methanol. Partially soluble in ethanol.
| Tg | 50.8 C |
|---|---|
| Refractive Index | 1.529 |
Resources and Citations
- R. Cox, "Ketone Resin Varnishes" AIC Painting Conservation Catalog, Varnishes and Surface Coatings, p. 75, 1998
- Conservation Materials Ltd., Catalog
- Teri Hensick, contributed information, 1998
- Comment: www.hants.org.uk/museums/ofr/cmeth_t.html (Note: this website is no longer active)