An Improved Solvent for Gums and Resins, and Method of Making the same.
Year: 1892

page_text: te of Application, 14th June, 1892-Accepted, 22nd Oct., 1892
COMPLETE SPECIFICATION.
An Improved Solvent for Gums and Resins, and Method of Making
the same.
I, WILLIAM READ Jr., of Needham, in the County of Norfolk and State of
Massachusetts, United States of America, Gentleman, do hereby declare the nature
of this 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 provide an effective and comparatively
inexpensive compound for use as a solvent of shellac and other gums, and for other
purposes such as dissolving the dry and hardened varnish in brushes which have
been left saturated with the same, and it consists, first, in a compound composed of
coal-tar naptha, petroleum naptha, and a sprit such as wood or grain alcohol; and,
secondly, in the improved method hereinafter described of making said compound.
In carrying out my invention, I mix suitable parts of petroleum naptha, otherwise
known as benzine, and coal-tar naptha, otherwise known as benzole. These
ingredients will unite readily when there is a larger percentage of coal-tar naptha
than of petroleum naptha; but, if combined in substantially equal parts, I find that
their chemical union is facilitated by the use of a small proportion of castor oil;
but I do not limit myself to the use of the last named ingredient, and may omit the
same or substitute any other suitable oil therefor, such as oil citronella, and oil
mirbane.
To the above-described ingredients I add a suitable proportion of either wood or
grain alcohol, which unites chemically with the other ingredients, the whole con-
stituting an effective and comparatively inexpensive solvent for shellac and other
resinous gums which cannot be perfectly dissolved by the use of grain or wood
alcohol alone.
I prefer to make the compound by the following method, which constitutes a part
of my invention :
I mix the coal-tar naptha and petroleum naptha preferably in equal parts
(although they may be more or less unequal), and to the mixture add wood or grain
alcohol in the proportion of about one part of the alcohol to eight parts of the
mixture of the other ingredients. I find that alcohol, used in a considerably smaller
quantity than the other ingredients, causes an immediate precipitation of a by-
product consisting of a resinous and somewhat oleaginous material, which amounts
to about one-tenth of the whole, and is of value because it is suitable for use as an
oil for dissolving gums. The composition or residuum after the precipitation of this
by-product, is a clear and colorless spirit, to which I prefer to add a small quantity
of a suitable essential oil for the purpose of deodorizing it. To the said residuum
spirit, produced as described, I add a suitable quantity of wood or grain alcohol,
the whole forming an effective solvent for resinous gums.
I have found by practical experience that alcohol when added to coal-tar naptha
alone combines therewith. When alcohol in a small quantity is added to petroleum
naptha it does not combine with the latter, but changes the character of the
petroleum naptha into a milky compound, which proves that it has disturbed the
oils in the petroleum naptha and caused them to precipitate. By combining coal-
tar naptha and petroleum naptha before this precipitation takes place and afterwards
adding the alcohol, a precipitation is caused to take place from both the coal-tar
naptha and the petroleum naptha, the precipitate therefore consisting of the oils in
the two napthas, hence the fluid is deprived of all deleterious oils for making the
improved solvent. The by-product is composed of the oils thus precipitated, viz. :
the creosote oil and carbolic oil of the coal-tar naptha, and the dead oil of the
petroleum naptha.

page_text: This solvent is more effective than any other of which I am aware, and is also
comparatively inexpensive, its cost being materially reduced by the extraction of
the by-product, which has a commercial value, while its extraction does not impair
the solvent properties of the composition.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed,, I declare that what I
claim is:
1. A solvent for gums, composed of coal-tar naptha, petroleum naptha, and a
spirit such as wood or grain alcohol, as set forth.
2. The improved method of making a solvent, consisting in adding to a mixture
of coal-tar naptha and petroleum naptha a smaller proportion of wood or grain
alcohol and thereby precipitating the described by-product, and then adding more
alcohol to the residuum, as set forth.
WILLIAM READ, JR.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.