Process for Purifying or Clarifying Shellac or Solutions of Shellac.
Year: 1887

page_text: Date of Application, 17th Nov., 1887
Complete Specification Left, 15th Sept.,
1888
Complete Specification Accepted, 16th Nov., 1888
Process for Purifying or Clarifying Shellac or Solutions of Shellac.
I, FREDERICK CRANE, Manufacturing Chemist, of Short Hills, New Jersey, United
States of America, temporarily of 433, Strand, London, do hereby declare the nature
of this invention to be as follows
This invention has for its object to obtain clear, pure, and concentrated solutions of
shellac applicable for the manufacture of varnish, and for other purposes.
I dissolve the shellac in methyl-alcohol or other suitable liquid, preferably in the
proportion of 4 to 6 pounds of shellac to one gallon of the solvent, add benzine, and
agitate the compound together. The compound liquid is then allowed to stand, benzine
separates from the alcoholic solution and carries the wax with it; so that a clear
solution of shellac will be left in the vessel, if the benzine solution is drawn off.
Instead of benzine, I may employ other solvents of wax (or other undesirable
admixture of the shellac) provided they are antagonistic to the solvent of the shellac,
or I may employ a mixture of such solvents. Instead of treating a solution of shellac
in the manner described above, I may clarify or purify dry shellac by agitating it with
benzine or other suitable solvent of the impurity or admixture.
Dated this 16th day of November, 1887.
FAIRFAX & WETTER,
433, Strand, London,
Agents for the Applicant.

page_text: Process for Purifying or Clarifying Shellac or Solutions of Shellac,
I, FREDERICK CRANE, Manufacturing Chemist, of Short Hills, New Jersey, United
States of America, do hereby declare the nature of my invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention has for its object to obtain clear, pure and concentrated solutions of
shellac applicable to the manufacture of varnishes and to other uses.
I first dissolve the shellac in ethyl-alcohol, methyl-alcobol, propyl-alcohol, iso-propyl
alcohol, butyl alcohol, or iso-butyl alcohol, or mixtures of any two or more of them, or
in any other alcoholic solvent of the shellac to be cleared, preferably in the proportion
of from four to six pounds of shellac to one gallon of tho solvent used. I then add to
the solution of shellac any solvent or mixture of solvents of the soluble impurities
contained in the shellac to be cleared, which is immiscible with the solvent of the
shellac, to about equal volume with the alcoholic solvent, and thoroughly agitate the
compound. I then allow the compound to stand for from one to two weeks, according
to the thickness of the shellac solution and the size of the batch to be cleared (a thin
solution or a small batch requiring less time and a thick solution or large batch more
time to thoroughly separate), when the solvent of the soluble impurities of the shellac
will have dissolved them out and separated with them in solution from the alcoholic
solution, and the alcoholic solution may then be drawn off, leaving the other solution
in the vessel. Care should be taken in using this process to keep the compound at a
temperature of between 30 degrees and 35 degrees C.
The following is one method of using this process:
To 100 gallons of methyl-alcohol, I add 500 pounds of shellac, either garnet, orange
or bleached, and to the solution I add 100 gallons of benzine (petroleum naphta,
62° Beaumé) and thoroughly agitate the mixture. I then allow the compound to
stand at a temperature of from 30° to 35° C. for two weeks, when the methyl-alcohol
having in solution the shellac will be found to have separated from the benzine having
in solution the soluble impurities contained in the shellac, and I then draw off the
shellac solution, and leave the benzine solution in the vessel.
This is only intended as an example and not as limiting this patent to the use of the
solvents named. This process is particularly adapted to clearing a solution of bleached
shellac, but may be used with any other shellac. The result is a beautiful, clear and
concentrated solution of shellac, especially adapted for use as a varnish or in the
manufacture of varnishes.
Having now particularly described and ascertained the nature of this invention,
and in what manner the same is to be performed, I declare, that I claim :
1st. The process of producing pure, clear and concentrated solutions of shellac, by
dissolving the shellac in any alcoholic solvent thereof, subsequently adding to the
solution a solvent of the soluble impurities of the shellac immiscible with the alcoholic
solvent, permitting the compound to stand until the liquids have separated, and then
drawing off the alcoholic solution, substantially as described.

page_text: 2nd. In the art of manufacturing clear and concentrated solutions of shellac, the use
of ethyl-alcohol, methyl-alcohol, propyl-alcohol, iso-propyl-alcohol, butyl-alcohol or
iso-butyl-alcohol, or other alcoholic solvents of shellac, or mixtures of any two or more
of them, in conjunction with benzine or other solvent of the soluble impurities of the
gum resin, immiscible with the alcoholic solvent of the shellac, substantially as
described.
3rd. A clear, pure and concentrated solution of shellac, produced by first dissolving
the shellac in an alcoholic menstruum, subsequently dissolving out the soluble
impurities of the gum resin with benzine or other solvent of such impurities immiscible
with the alcoholic solvent used, and drawing off the alcoholic solution, substantially as
described.