Improvements in the Manufacture of Pyroxyline Solutions and Compounds for Varnishes and Coatings.
Year: 1892

page_text: Date of Application, 5th Apr., 1892
Complete Specification Left, 5th Jan., 1893-Accepted, 18th Feb., 1893
[Communicated from abroad by FREDERICK CRANE, of Bloomfield, New Jersey,
United States of America.]
Improvements in the Manufacture of Pyroxyline Solutions and
Compounds for Varnishes and Coatings.
I, JOSEPH SINCLAIR FAIRFAX, of 433 Strand, in the County of London, Patent
Agent and Consulting Engineer, do hereby declare the nature of this invention to
be as follows :—
This invention, as communicated to me by my foreign correspondent, relates to
improvements in the manufacture of pyroxyline solutions and compounds thereof
for various useful purposes.
The pyroxyline or nitro cellulose used in the manufacture of these compounds is
of the kind or grade known as soluble pyroxyline, and is obtained by subjecting
vegetable fibre to the action of nitric acid, or of nitric and sulphuric acids, in a
manner well known.
The solutions and compounds referred to are in a liquid or semi-liquid condition
at the time of their use or application as varnishes or coatings, and which eventually
become set and hard. The invention consists in the employment of certain known
fluids which has been 'discovered to possess the property of dissolving pyroxyline
at ordinary temperatures, and which also impart to the pyroxyline solution or
compound made by their aid certain peculiar and desirable properties.
For many purposes for which pyroxyline compounds are used, and particularly
when such compounds are used in the form of thin solutions for lacquers or varnishes
-or in the form of heavier solutions to be evaporated down to a solid film-it has
been found especially desirable to use a solvent for the pyroxyline which would
volatilize with considerable rapidity, and at the same time would not absorb.water
or moisture from the atmosphere to any appreciable extent. So far as is known,
no one solvent for pyroxyline combined both these properties of quick drying and
non-affinity for water, and it has been customary to use a compound solvent
therefor. By this is meant a, solvent consisting of several distinct substances
artificially united for the purpose of producing the kind of solvent required, and
this compound solvent.would consist in part at least-of liquids having an affinity
for water; as, for example, methyl alcohol and acetone. The compound solvent
would also partly consist of non-hygroscopic liquids, (not having an affinity for
water), such as amyl acetate and benzine, the two classes of solvents being mingled
in such proportions as would be necessary-in each case-to produce a solvent
sufficiently, non-hygroscopic for the use for which the pyroxyline compound was
required.
Now it has been discovered and communicated to me by my foreign corre-
spondent, that the substance commonly known to the trade as acetone oil-when
purified as hereinafter mentioned-is not only a powerful solvent of pyroxyline
but dries with considerable rapidity: that it is practically non-hygroscopic : ..and
can be used either alone or in combination. with some miscible, and cheaper liquid,
(such as benzine), as a solvent for pyroxyline in all pyroxyline compounds where
heretofore it has been necessary to use compound solvents.
This acetone oil is composed mainly of what are known as volatile ketones,
boiling below 150° C. These ketones may be obtained by the destructive distilla-
tion of metallic acetates. While a chemically pure and dry acetate should yield a
pure acetone with simultaneous formation of the corresponding carbonates, the
crude or commercial acetate will yield a distillate containing in addition to

page_text: acetone and water these higher ketones along with certain acetates and other
decomposition products.
The acetone and water having been eliminated by the usual processes of
fractionation and absorption with dehydrating agents there remains an oil, which
my foreign correspondent informs me has valuable properties.
For some uses, however, it is not necessary to remove the acetone, for it is a
solvent of pyroxyline, and where a non-hygroscopic liquid is not required, it
is not injurious to the compound, even if present in considerable proportions;
while if a practically non-hygroscopic solvent is desired, a small proportion of
acetone is rendered inoxious by the presence of these non-hygroscopic higher boiling
ketones.
When the acetone oil has been purified as above stated by removing the excess
of acetone and water, the volatile ketones remaining are but slightly absorbent of
water—that is, are practically non-hygroscopic-and are miscible in large propor-
tions with petroleum and mineral napthas, and many of the other liquids useful in
pyroxyline solutions or compounds.
It is to be understood that I do not confine myself to any particular source for,
or process of, obtaining this mixture. For example, the acetates of calcium,
barium, strontium, lead, and probably others when destructively distilled, all
decompose with the formation of ketones as an invariable feature; and therefore,
1 desire to avail myself of any of the acetates as a source of the said ketone oil
mixture. In applying the invention, I may employ these volatile ketones alone,
or with other miscible harmonious liquids in compounds of pyroxyline. Nor do I
intend to confine myself strictly to the boiling point mentioned, but merely give
the boiling point of 140° C. as one at which the most valuable of these products
will have come over in fractionation.
Having thus outlined the invention I will now proceed to specify some of the
mixtures and uses to which the same may be applied. For pyroxyline compounds
to be used as lacquers or varnishes where it is essential that the film or coating
remaining after the solvent has evaporated should be adhesive, tough, hard, smooth,
free from cloudiness, and especially where quick drying qualities are essential, the
following formulas have been found useful.
15 gallons methyl alcohol or acetone.
50 gallons petroleum naptha.
35 gallons volatile ketones or acetone oil.
1 11
1
Or for a solution required to be still more non-hygroscopic{
50 gallons volatile ketones or acetone oil.
50 gallons petroleum naptha.
25 pounds soluble pyroxyline.
It will be understood that the consistency of these solutions may be varied by
using more or less pyroxyline, but the above will dry at ordinary temperatures,
and will produce a varnish film having the desirable qualities above mentioned;
and that other substances may be combined with the above to meet special
requirements.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Pyroxyline Solutions and
Compounds for Varnishes and Coatings.
I, JOSEPH SINCLAIR FAIRFAX, of 433, Strand, in the County of London,
Patent Agent and Consulting Engineer, 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, as communicated to me by my foreign correspondent, relates to
improvements in the manufacture of pyroxyline solutions and compounds thereof
for various useful purposes; and it refers to solutions and compounds of a similar
nature to those employed in my application No. 6543 of even date herewith.
The pyroxyline (or nitro cellulose used in the manufacture of these compounds)
is of the kind or grade known as soluble pyroxyline, and is obtained by subjecting
vegetable fibre to the action of nitric acid, or of nitric and sulphuric acids; in a
manner well known.
The solutions and compounds referred to are in a liquid or semi-liquid condition
at the time of their use or application as varnishes or coatings, and which eventually
become set and hard. The invention consists in the employment of certain known
fluids which have been discovered to possess the property of dissolving pyroxyline
at ordinary temperatures, and which also impart to the pyroxyline solution or
compound made by their aid certain peculiar an desirable properties. For many
purposes for which pyroxyline compounds are used, and particularly where such
compounds are used in the form of thin solutions for lacquers or varnishes-or in
the form of heavier solutions to be evaporated down to a solid film-it has been
found especially desirable to use a solvent for the pyroxyline which would
volatilize with considerable rapidity and at the same time would not absorb water
So far as hitherto
or moisture from the atmosphere to any appreciable extent.
known, no one solvent for pyroxyline combined both these properties of quick
drying and non-affinity for water, and it has been customary to use a compound
solvent therefor. By this is meant a solvent consisting of several distinct substances
artificially united for the purpose of producing the kind of solvent required, and
this compound solvent would consist-in part at least-of liquids having an affinity
for water; as, for example, methyl alcohol and acetone. The compound solvent
would also partly consist of non-hygroscopic liquids, (not having an affinity for
water), such as amyl acetate and benzine, the two classes of solvents being mingled
in such proportions as would be necessary-in each case-to produce a solvent
sufficiently non-hygroscopic for the use for which the pyroxyline compound was
required.
Now it has been discovered, and communicated to me by my foreign correspon-
dent, that the substance commonly known to the trade as acetone oil-when purified
as hereinafter mentioned-is not only a powerful solvent of pyroxyline but dries
with considerable rapidity; that it is practically non-hygroscopic; and can be used
either alone or in combination with some miscible and cheaper liquid, (such as
benzine), as a solvent for pyroxyline in all pyroxyline compounds where heretofore
it has been necessary to use compound solvents.
This acetone oil is composed mainly of what are known as volatile ketones,
boiling below 140° C. These ketoues may be obtained by the destructive distilla-
tion of metallic acetates. While a chemically pure and dry acetate should yield a
pure acetone with simultaneous formation of the corresponding carbonates, the
crude or commercial acetate will yield a distillate containing in addition to acetone
and water these higher ketones along with certain acetates and other decomposition
products.

page_text: The acetone and water having been eliminated by the usual processes of fractiona-
tion and absorption with dehydrating agents there remains an oil, which my foreign
correspondent informs me has valuable properties.
For some uses, however, it is not necessary to remove the acetone for it is a
solvent of pyroxyline, and where a non-hygroscopic liquid is not required, it is not
injurious to the compound, even if present in considerable proportions; while if a
practically non-hygroscopic solvent is desired, a small proportion of acetone is
rendered inoxious by the presence of these non-hygroscopic higher boiling ketones.
When the acetone oil has been purified as above stated by removing the excess
of acetone and water, the volatile ketones remaining are but slightly absorbent of
water that is, are practically non-hygroscopic-and are miscible in large propor-
tions with petroleum and mineral napthas, and many of the other liquids useful in
pyroxyline solutions or compounds.
It is to be understood that I do not confine myself to any particular source for
or process of, obtaining this mixture. For example, the acetates of calcium,
barium. strontium, lead, and probably others when destructively distilled, all
decompose with the formation of ketones as an invariable feature; and therefore;
I desire to avail myself of any of the acetates as a source of the said ketone oil
mixture. In applying the invention, I may employ these volatile ketones alone, or
with other miscible harmonious liquids in compounds of pyroxyline. Nor do I
intend to confine myself strictly to the boiling point mentioned, but merely give
the boiling point of 140° C. as one at which the most valuable of these products
will have come over in fractionation.
Having thus outlined the invention I will now proceed to specify some of the
mixtures and uses to which the same may be applied. For pyroxyline compounds
to be used as lacquers or varnishes where it is essential that the film or coating
remaining after the solvent has evaporated should be adhesive, tough, hard, smooth,
free from cloudiness, and especially where quick drying qualities are essential, the
following formulas have been found useful.
15 gallons methyl alchol or acetone.
50 gallons petroleum naptha.
35 gallons volatile ketones or acetone oil.
in sounds soluble numaruline
50 gallons volatile ketones or acetone oil.
50 gallons petroleum naptha.
25 pounds soluble pyroxyline.
It will be understood that the consistency of these solutions may be varied by
using more or less pyroxyline, but the above will dry at ordinary temperatures,
and will produce a varnish film having the desirable qualities above mentioned;
and that other substances may be combined with the above to meet special
requirements.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The combination of acetone oil with pyroxyline, substantially as and for the
purpose hereinbefore described.
2. The combination of purified acetone oil or higher ketones with pyroxyline to
form a practically non-hygroscopic quick drying solution, substantially as and for
the purpose hereinbefore described.
3. The combination of acetone oil, or of higher keytones, with pyroxyline and
miscible harmonious liquids, substantially as and for the purpose herein before
described.

page_text: 4. The combination of acetone oil, or of higher ketones, with pyroxyline and
miscible harmonious liquids, substantially as and in the proportions herein before
described and specified.
Dated this 5th day of January 1893.
FAIRFAX & WETTER
433, Strand, London, Agents for the Applicant.