The term shellac is derived from shell-lac (the word for the refined lac in flake form) but has come to refer to all refined lac whether dry or suspended in an alcohol-based solvent.

Shellac is primarily used as a wood sealer and finisher today. It has the great advantage of being soluble in ethyl or denatured alcohol and an environmentally safe solvent. Alcohol solvents also render shellac a quick-dry—shellac coatings on wood generally dry in about 45 minutes, as opposed to oil finishes which take many hours to dry. In addition, shellac does not fade in sunlight or oxidize over time. However, shellac has a limited shelf life and may not dry properly if it has exceeded the shelf life recommended by the manufacturer. This shelf life may be as short as six months or as long as three years depending on the manufacturer's additives.

Industrial uses for shellac include floor polishes, inks, grinding wheels, electrical insulation, and leather dressings. This natural, resinous sealer is non-toxic and is Federal Drug Administration (FDA) approved for use to coat candies, pharmaceuticals, fruit, and baby and children's furniture.

Shellac is available at most hardware or paint stores in clear or white shellac or orange shellac, which imparts an orange-red tint to natural wood. Other tints derive their color, not from dyes or bleaches, but because of the tree to which the lac bug has attached itself—the sap affects the color of the bug secretions thus altering the color of the refined shellac. Shellac may be applied to wood, over varnish, paint, glass, ceramics, and even plastic with remarkable adherence, but it cannot be used under synthetic sealers such as polyurethane.

MANUFACTURING PROCESS OF SHELLAC

The seedlac is melted by steam heat. Oxalic acid and titanium dioxide are mixed with the melted lac at this stage. The molten lac is then squeezed through the filter by means of hydraulic pressure. The filtered molten lac is drawn into long and continuous sheets with the help of a roller.

These sheets are broken into pieces, called flakes. Various grades of machine-made shellac flakes are available commercially, that include Orange Lemon shellac, T.N. shellac, Orange fine shellac, etc.

Aleuritic Acid is obtained from Shellac by saponification and accounts for about 35% of its constituent material.

PROPERTIES:

Aleuritic Acid is usually sold as a white or slightly yellow odorless powder or granule. It is moderately soluble in hot water or lower alcohols (e.g. ethyl, isopropyl, and methyl alcohols) and crystallizes after the solution is cooled. It has a melting point of around 95-98 degrees Celsius.

USES:

Pharmaceuticals Industry:

Aleuritic Acid is used in the synthesis of Glucose Monoaleuritate (a non-toxic, non-hemolytic water-soluble compound), which is an isocaloric substitute for dietary Tripalmitin.

Wood Treatment Industry:

Aleuritic acid esters are used in the preparation of lacquers and varnishes.

Other Industries:

Aleuritic Acid is used in the preparation of plastics, providing good adhesive properties by combining it with Rosin, Pithalic Andydride, and Glycerin.

In the  Personal Care industry, Aleuritic Acid is used as a starting material for the synthesis of Civetone, Ambrettolide, and Isoambrettolide, which are used as fixatives of musk-like aromas in the manufacture of perfume.