shellac(redirected from LACCA)
Also found in: Dictionary, Thesaurus, Medical, Acronyms.
shellac,solution of laclac,
resinous exudation from the bodies of females of a species of scale insect (Tachardia lacca), from which shellac is prepared. India is the chief source of shellac, although some is obtained from other areas in Southeast Asia.
..... Click the link for more information. in alcohol or acetone. In commerce the name is applied to the resinous substance (lac) itself rather than to the solution. It ranges in color from orange to light yellow depending upon the extent to which it has been purified; the darker shellacs are the less pure. When bleached it is known as white shellac. Applied to surfaces such as wood and plaster, the solution forms a hard coating upon evaporation of the solvent. Shellac is widely used as a spirit varnishvarnish,
homogeneous solution of gum or of natural or synthetic resins in oil (oil varnish) or in a volatile solvent (spirit varnish), which dries on exposure to air, forming a thin, hard, usually glossy film.
..... Click the link for more information. , as a protective covering for drawings and plaster casts, for stiffening in the manufacture of felt hats, in making sealing wax, and in electrical insulation.
a natural resin secreted by the lac insect, which parasitizes tropical and subtropical woody plants. Shellac apparently consists mainly of aliphatic polyhydroxy acids. It is freely soluble in alkalies and lower aliphatic alcohols, poorly soluble in benzene, and almost insoluble in gasoline, fats, and oils. Shellac is peeled off the tree bark, processed with hot water, melted, and filtered. It may be dark colored, orange, or light colored. Colorless shellac is obtained by bleaching the colored types with animal charcoal, bleaching powder, or sodium sulfate. Shellac has limited uses, principally in the manufacture of alcohol varnishes and polishes.