Lime casein

Description

A paint binder or adhesive prepared by hydrolyzing Casein powder in water with Lime (Calcium oxide). Lime casein is a clear, viscous solution that dries to form a water-insoluble film. Lime casein has a high pH (9.0-9.9) compared to Ammonium casein (8.0-9.0), and Borax casein (7.0-7.8). Lime casein is often used as a ground or size for wall paintings on lime plaster, gypsum plaster and stone. It dries to a brittle, insoluble, matte film. Occasionally a plasticizer, such as Glycerol or Sorbitol and a preservative, such as phenol, are added to the solution. Lime casein is also used as a paint binder. Because of its alkalinity, however, its pigment palette is limited (see fresco pigments). Earlier conservation uses have included lime casein as a consolidant for wall paintings and wall plaster.

Synonyms and Related Terms

caseinato de calcio (Esp.); lime-casein; casein adhesive; casein glue; calcium caesinate

Risks

• Casein is susceptible to biodeterioration, especially in humid environments.

Resources and Citations

• H.K.Salzberg, "Casein Glues and Adhesives" in Handbook of Adhesives, I.Skeist (ed.), Van Nostrand Reinhold, New York, 1977, p.158-171.

• K.Wehlte, The Materials and Techniques of Painting, Van Nostrand Reinhold Co., New York, 1975.

• Irving Skeist, Handbook of Adhesives, Van Nostrand Reinhold Company, New York, 1977

• Website: http://www.jcms.ucl.ac.uk/issue5/cons98.html#farmakalidis