Shellac purified

JP Purified shellac, White shellac PhEur Lacca USPNF Shellac... 

The PhEur 2005 defines four types of shellac depending on the nature of the treatment of the crude shellac (seed lac) wax-containing shellac bleached shellac dewaxed shellac and bleached dewaxed shellac. The USPNF 23 similarly defines four types of shellac orange shellac dewaxed orange shellac regular bleached (white) shellac and refined bleached shellac. The JP 2001 defines two types purified shellac and white shellac (bleached). 

Shellac (purified lac) dissolves at pH greater than 7 and can be used alone or in combination with other materials. It is soluble in ethanol, propylene glycol, and alkaline solutions. 

The female Indian lac bug, Lacifer lacca, had captured Baekeland s interest. This Uttle creature was the source of all the world s shellac. It sucked tree sap and converted it into a resin. The resin was scraped off the trees and purified into a substance that, when applied to wood, provided a nice shiny finish. But now, within the burgeoning field of electricity, shellac had found a brand new use it was an ideal insulating material. Unfortunately, it took fifteen thousand insects about six months to produce a pound of shellac. What the world needed was a cheap source of synthetic shellac, and Baekeland was going to find it. 

Definition Purified and bleached lac, the resinous secretion of the insect Laccifer (Tachardia) lacca Empirical Shellac, purified... 

Lacca Lac resin Shellac gum Shellac orange S-40 Shellac, purified Stick lac White sheiiac... 

Shellac A coating made from purified lac dissolved in alcohol, often bleached white. 

A group of homopterous insects, chiefly Laccifera lacca, feeding on various forest trees produce an excretion on the bark of the tree which eventually covers the insects. This has been a commercial product for a long time as lac for making varnish or in a purified form as shellac. As with many insect products, it is not yet certain whether lac is made by the insects themselves or by symbiotic micro-organisms in them. Lac consists of a mixture of polyhydroxylated palmitic acids and sesquiterpenes. The palmitic acids are hydroxylated at C-10 and C-11 or C-16 or all three, as in aleuritic acid (Figure 6.22). 

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