Year: 1887

page_text: 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:-
Hitherto non-hygroscopic varnishes, possessing desirable qualities of hardness,
contractility, and transparency, have been made by dissolving pyroxyline in suitable
non-hygroscopic menstrua; and bygroscopic varnishes possessing desirable qualities
of adhesiveness and body have been prepared with resins or gum resins as a base.
Resins, or gum resins, may have been added to pyroxyline varnish in small quantities,
but I am not aware that it has been found practicable to introduce sufficient gum
resin or resin into the pyroxyline solution to obtain the peculiar properties of
resinous varnishes, without injuring the good qualities of pyroxyline varnish.
My correspondent, bowever, has discovered, that resins or gum resins on the one
hand, and pyroxyline on the other hand, should be separately dissolved in appropriate
and harmonious menstrua, that solutions of resin or gum resin, if hygroscopic, should
be concentrated, that in some cases, for instance in using bleached shellac, the resin
or gum resin must be clarified before the final mixing.
In order to produce a practically non-hygroscopic, free flowing, smooth, transparent,
and adhesive varnish, which becomes very hard after drying, and may be used for all
ordinary purposes, I make a concentrated solution of resin or gum resin (properly
clarified when necessary) in suitable menstrua, for instance, methyl-alcohol, and also
a solution of pyroxyline in appropriate menstrua, for instance, butyl- or propyl- or
amyl-acetate, or mixtures of two or more of these solvents and mix the two solutions
D

page_text: alone, or with other miscible liquids, in such proportions that the product will
contain the desired quantities of resin and pyroxyline and be practically non-
hygroscopic. The following will serve as an example. I dissolve 26 lbs. of shellac,
in 4 gallons of methyl-alcohol and 30 pounds of pyroxyline in 60 gallons of propyl-
butyl-, or amyl-acetate, or a mixture of two or more of these acetates, and mix these
two solutions together with 30 gallons of amyl-alcohol, to which may be added
6 gallons of methyl-alcohol.
If desirable suitable colouring matter may be added to the varnish.

page_text: 1, FREDERICK CRANE, Manufacturing Chemist, of Short Hills, New Jersey, United
States of America, 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 :-
Hitherto non-hygroscopic varnishes, possessing desirable qualities of hardness,
contractility and transparency, have been made by dissolving pyroxyline in suitable
non-hygroscopic menstrua ; and hygroscopic varnishes possessing desirable qualities
of adhesiveness and body have been prepared with resins or gum resins as a base.
Resins or gum resins may have been added to pyroxyline varnish in small quantities,
but it has not heretofore been found practicable to introduce into the pyroxyline
solution sufficient resin or gum resin to obtain these peculiar properties of resin
varnishes, without injuring the good qualities of the pyroxyline varnish, by making
the resulting mixture turbid or cloudy, which interfered seriously with the utility of
the mixture as a varnish or lacquer.
The object of this invention is to secure a practically non-hygroscopic varnish or
lacquer having as much adhesiveness as resin varnishes, combined with the transparency,
toughness, hardness, contractility and purity of pyroxyline varnishes, and also to
secure a varnish or lacquer with more body and that will cover better than can be
obtained by the use of pyroxyline alone, as a base.
My correspondent has discovered by a long series. of experiments, that by using a
concentrated solution of shellac cleared and purified in the manner indicated in a
separate application for a patent, No. 15772, dated the 17th. of November 1887, or in
some equivalent manner, and mixing the cleared, purified and concentrated solution
of shellac with a solution of pyroxyline in some non-hygroscopic menstruum
harmonious or miscible with that used as a solvent of the shellac, shellac may be
mixed with the pyroxyline in any desired proportions provided sufficient solvent be
present, and still produce a clear, pure, free flowing, smooth, adhesive, tough and
transparent varnish, practically non-hygroscopic, and having all the desirable qualities
of resin or gum resin varnishes, and also the useful qualities of the pyroxyline varnish.
Manifestly, however, the presence of a large excess of shellac will communicate to
the varnish in a larger degree the peculiar properties of a shellac varnish, and the
presence of a large excess of pyroxyline will cause the varnish to have the peculiar
properties of a pyroxyline varnish in a larger degree. In making a varnish suitable
for use on metal surfaces, when contractility is an important feature, a less proportion
of the gum must be used than in making a varnish for other surfaces where body
is the thing especially desired. Thus, for example, in making this varnish for use
on metal, the following formula has been found to work well and to produce
excellent results.

page_text: But the proportion of the shellac solution may be reduced in this formula to one
tenth of one gallon and still produce good results for use on metal surfaces.
It will be understood, that the above is simply an example and is not intended to
limit this invention to the solvents or proportions mentioned.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that I
claim:
1st. As an improvement in the manufacture of varnishes and lacquers, the use of
a solution of shellac cleared and purified in the manner indicated in my application
for a patent No. 15772 of 1887, in combination with a solution of pyroxyline in some
practically non-hygroscopic menstruum miscible with the shellac solution.
2nd. As an improvement in the art of manufacturing varnishes, the use of a clear,
pure and concentrated solution of bleached shellac, in combination with a solution
of pyroxyline in a practically non-hygroscopic menstruum miscible with the shellac
solution.
3rd. As an improvement in the art of manufacturing varnishes, the use of a clear,
pure and concentrated solution of bleached shellac prepared in the manner indicated
in my application for a Patent, No. 15772 of 1887, in combination with a solution
of pyroxyline in some practically non-hygroscopic menstruum miscible with the
shellac solution.
4th. A practically non-hygroscopic, free flowing, smooth, transparent, hard and
adhesive varnish produced by the use of a clear, pure and concentrated solution of
shellac, in combination with a solution of pyroxyline in a practically non-hygroscopic
menstruum miscible with the shellac solution.
5th. A practically non-hygroscopic, free flowing, smooth, transparent, hard and
adhesive varnish produced by the use of a concentrated solution of bleached shellac
cleared and purified in the manner specified in my application for a Patent No. 15772
of 1887, in combination with a solution of pyroxyline in a substantially non-
bygroscopic menstruum miscible with the shellac solution.
Dated this 15th day of September 1888.
FREDERICK CRANE.
By Fairfax & Wetter,
433, Strand, London,
Agents.