Improvements in or relating to Varnishes or other Coatings.
Year: 1890

page_text: Date of Application, 13th Aug., 1890
Complete Specification Left, 5th May, 1891-Accepted, 6th June, 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by FREDERICK CRANE, of Short Hills, New Jersey,
United States of America, Manufacturing Chemist.]
Improvements in or relating to Varnishes or other Coatings.
I, JOSEPH SINCLAIR Fairfax, of 433, Strand, London, in the County of
London, Patent Agent and Consulting Engineer, do hereby declare the nature of
this invention to be as follows:-
It is well known that varnishes for use on wood and other surfaces have been
made from different resins or gum resins such as copal, sandarac, and shellac-
dissolved in oil and commonly known as oil varnishes-or dissolved in alcohol or
other volatile solvent, and commonly known as spirit varnishes.
The difficulties experienced in using oil varnishes are, that while forming more
or less cohesive films they are slow drying, (thus consuming time in their applica-
tion) they lack hardness and have a tendency to crack, lose their brilliancy,
discolour, and are injuriously affected by exposure.
The difficulties experienced in the use of spirit varnishes are even greater, for
while the spirit varnishes are, as a rule, quicker drying and harder than the oil
varnishes, the volatile menstrua, in which the resins or gum resins (forming their
bases) are dissolved, do not impart good flowing qualities nor the tough and cohesive
film of the oil varnish; while the solvent in the spirit varnish-from its greater
solvent power-acts on the under coats more quickly than the oil, and impairs
their brilliancy; thus rendering it difficult to apply repeated coats and obtain their
full effect.
My foreign correspondent informs me that it has been the object of experiments
to produce a resin or gum resin spirit varnish which should form a film having the
hardness, transparency, and quick drying qualities of the film in a spirit resin or
gum resin varnish, combined with the cohesiveness, clasticity and toughness of the
film in an oil varnish, without the effects of either.
It is well known that the presence of oil in oil varnishes contributes the qualities
of cohesiveness, elasticity and toughness to the film, and that as the oil slowly
oxidises the film loses those qualities and becomes brittle and cracked, and
frequently discolours. It was required, therefore, to find some substance which
could be introduced into a spirit resin or gum resin varnish, and which would
contribute to the cohesiveness, elasticity and toughness of the oil in an oil varnish,
and would unlike the oil-remain permanently unchanged in the varnish film.
It has been discovered and communicated to me that if pyroxyline or soluble
nitro-cellulose be introduced in proper proportions into a spirit resin or gum resin
varnish, it renders the film cohesive, tough, elastic, and remains chemically
unchanged in the film; and after the volatilization of the solvents used, the film
retains its cohesiveness, toughness, and elasticity, and remains unaffected by the
atmosphere. It has also been discovered that the presence of pyroxyline in the
varnish causes the formation of a film which, like the film of an oil varnish, is not
Therefore, a
(when thoroughly dry), casily dissolved by subsequent coats.
number of coats of varnish may be applied to the surface with very little loss
of brilliancy, and any action of the upper on the under coats may be further
prevented by using solutions having very little free solvent; that is, practically
saturated solutions.
In practising the invention, 1 first dissolve the resin or gum resin and pyroxyline
forming the base of the varnish, in any volatile solvent of both bases, in any
proportion from one part by weight of pyroxyline to three parts of resin, or gun
resin, up to equal parts by weight of the pyroxyline to the resin or gun resin, and

page_text: thoroughly stir—or otherwise agitate the mixture-and allow the solution to stand
until quite cleared by settling, when it is ready for application to the surface to be
varnished. But in practice, I prefer to use one part by weight of pyroxyline to
two parts by weight of the resin or gum resin, as this has given the best
results.
The following formula has also been found to work well in practice, and produces
⚫an excellent varnish film, especially suited for outdoor work exposed to salt water:
Amyl acetate
Spirits of turpentine
Methyl alcohol
Pyroxyline
Shellac
50 gallons
25
"
25
"
37 pounds
37
"
In this formula ethyl, methyl, propyl or butyl acetate, or mixtures of them, may
be substituted for amyl acetate, and cedar and other similar essential oils may be
substituted for the spirits of turpentine; or the spirits of turpentine may be
omitted entirely and amyl acetate increased in proportion; also, rosin, or copal, or
sandarac resins or gun resins may be substituted for shellac, but I prefer to use
clear shellac as working better with the pyroxyline, and producing a tougher, more
transparent, and better varnish for most purposes.
It is to be understood that the composition of this varnish may be varied by
increasing the proportion of base, or diminishing the thickness by increasing the
solvent, but in practice I prefer to use solutions which are practically saturated, as
they are less liable to attack the under coats. I may also add to the varnish from
five to ten per cent. of linseed or other fixed oil, which for some purposes, improves
its spreading qualities. I may also add pigments and other colouring matter to
this varnish and thereby produce a paint which will have the hardness and durability
of a varnish.
The term resins or gum resins in this Specification is not intended to cover
balsams.
Dated this 10th day of July 1890.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Varnishes or other Coatings.
I, JOSEPH SINCLAIR FAIRFAX, of 433 Strand, London, 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 :-
It is well known that varnishes for use on wood and other surfaces have been
made from different resins or gum resins such as copal, sandarac, and shellac-
dissolved in oil and commonly known as oil varnishes or dissolved in alcohol or
other volatile solvent, and commonly known as spirit varnishes.
The difficulties experienced in using oil varnishes are, that while forming more
or less cohesive films they are slow drying, (thus consuming time in their applica-
tion) they lack hardness and have a tendency to crack, lose their brilliancy,
discolour, and are injuriously affected by exposure.
The difficulties experienced in the use of spirit varnishes are even greater, for
while the spirit varnishes are, as a rule, quicker drying and harder than the oil
varnishes, the volatile menstrua, in which the resins or gum resins (forming their
bases) are dissolved, do not impart good flowing qualities, nor the tough and
cohesive film of the oil varnish; while the solvent in the spirit varnish-from its
greater solvent power-acts on the under coats more quickly than the oil, and

page_text: impairs their primiancy; thus rendering IL dimicult to apply repeated coats and
obtain their full effect.
My foreign correspondent informs me that it has been the object of experiments
to produce a resin or gum resin spirit varnish which should form a film having
the hardness, transparency, and quick drying qualities of the film in a spirit resin
or gum resin varnish, combined with the cohesiveness, elasticity and toughness of
the film in an oil varnish, without the defects of either.
It is well known that the presence of oil, in oil varnishes, contributes the
qualities of cohesiveness, elasticity, and toughness to the film; and that as the oil
slowly oxidises the film loses those qualities and becomes brittle and cracked, and
frequently discolours. It was required, therefore, to find some substance which
could be introduced into a spirit resin or gum resin varnish, and which would
contribute to the cohesiveness, elasticity and toughness of the oil in au oil varnish,
and would unlike the oil-remain permanently unchanged in the varnish film.
It has been discovered, and communicated to me, that if pyroxyline or soluble
nitro-cellulose be introduced in proper proportions into a spirit resin or gum resin
varnish, it renders the film cohesive, tough, elastic, and remains chemically
unchanged in the film; and after the volatilization of the solvents used, the film
retains its cohesiveness, toughness, and elasticity, and remains unaffected by the
atmosphere. It has also been discovered that the presence of pyroxyline in the
varnish causes the formation of a film which, like the film of an oil varnish, is not
(when thoroughly dry), easily dissolved by subsequent coats. Therefore, a number
of coats of varnish may be applied to the surface with very little loss of brilliancy,
and any action of the upper on the under coats may be further prevented by using
solutions having very little free solvent; that is, practically saturated solutions.
In practising the invention, I first dissolve the resin or gum resin and pyroxyline
forming the base of the varnish, in any volatile solvent of both bases, in any
proportion from one part by weight of pyroxyline to three parts of resin, or gum
resin, up to equal parts by weight of the pyroxyline to the resin or gum resin, and
thoroughly stir or otherwise agitate the mixture-and allow the solution to stand
until cleared by settling, when it is ready for application to the surface to be
varnished. But in practice, I prefer to use one part by weight of pyroxyline to
two parts by weight of the resin or gum resin, as this has given the best results.
The following formula has also been found to work well in practice, and
produces an excellent varnish film, especially suited for outdoor work exposed
to salt water;
Amyl acetate
Spirits of turpentine
Methyl alcohol
Pyroxyline
Shellac
50 gallons
-
25
22
-
25
"2
-
37 pounds
-
37吋
"
In this formula ethyl, methyl, propyl or butyl acetate, or mixtures of them, may
be substituted for amyl acetate, and cedar and other similar essential oils may be
substituted for the spirits of turpentine; or the spirits of turpentine may be
omitted entirely and amyl acetate increased in proportion; also, rosin, or copal,
or sandarac resins or gum resins may be substituted for shellac, but I prefer to use
clear shellac as working better with the pyroxyline, and producing a tougher, more
transparent, and better varnish for most purposes.
It is to be understood that the composition of this varnish may be varied by
increasing the proportion of base, or diminishing the thickness by increasing the
solvent, but in practice I prefer to use solutions which are practically saturated, as
they are less liable to attack the under coats. I may also add to the varnish from
five to ten per cent. of linseed or other fixed oil, which for some purposes, improves
its spreading qualities. I may also add pigments and other colouring matter to
this varnish and thereby produce a paint which will have the hardness and durability
of a varnish.

page_text: The term resins or gum resins in this Specification is not intended to cover
balsams.
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 varnish adapted to produce a tough, elastic and cohesive film, containing
pyroxyline, or soluble nitro-cellulose, combined with resins or gum resins in the
proportion of from equal parts of pyroxyline and resin, to one part of pyroxyline to
three parts of resin, substantially as and for the purpose described.
2. A varnish adapted to produce a tough, elastic and cohesive film when used as
a finishing-varnish in conjunction with other varnishes, consisting of saturated
solutions of pyroxyline and resins or gum resins in suitable solvents in the propor-
tion of from equal parts of pyroxyline and resin, to one part of pyroxyline to three
parts of resin, substantially as and for the purpose described.
3. The herein-described spirit-varnish, composed of amyl acetate, spirits of
turpentine, methyl-alcohol, pyroxyline and shellac combined in about the proportions
herein described.
4. A coating comprised of an approximately saturated solution of pyroxyline and
resins or gum resins in suitable solvents in the proportion of from equal parts of
pyroxyline and resin, to one part of pyroxyline to three parts of resin, combined
with from five to ten per cent. of a fixed oil substantially as and for the purpose
described.
5. A paint composed of an approximately saturated solution of pyroxyline and
resins or gum resins in suitable solvents in the proportion of from equal parts of
pyroxyline and resin, to one part of pyroxyline to three parts of resin, combined
with a suitable pigment or pigments, substantially as and for the purpose described.
Dated this 5th day of May 1891.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.