IMPROVEMENTS IN THE MANUFACTURE OF OIL PAINTS
Year: 1873

page_text: LETTERS PATENT to John Argall, of Adderbury, in the County of
Oxford, Mining Engineer, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF OIL PAINTS."
Sealed the 24th June 1873, and dated the 7th January 1873.
PROVISIONAL SPECIFICATION left by the said John Argall at the
Office of the Commissioners of Patents, with his Petition, on the
7th January 1873.
I, JOHN ARGALL, of Adderbury, in the County of Oxford, Mining
Engineer, do hereby declare the nature of the said Invention for
“IMPROVEMENTS IN THE MANUFACTURE OF OIL PAINTS," to "be as follows:-
―:
In the ordinary manufacture of oil paints the colouring matters or
pigments are prepared by artificial chemical processes, and ground up
with drying oil either alone or mixed with artificially prepared carbonate
of lead or oxide of zinc, to give body or opacity to the paint.
In manufacturing oil paints according to my Invention I proceed as
herein-after described.

page_text: In order to give the required body or opacity to the paint I employ
as a basis the natural mineral, consisting of carbonate of baryta and
zinc, or I use native zinc ore containing no carbonate of baryta. I heat
the said compound of zinc and baryta, or the zinc ore in contact with
air, so as to effect what is commonly called the roasting of the said ore,
and its conversion when the zinc ore consists of a sulphide into oxide of
zinc. When the zinc ore contains no baryta I add carbonate of baryta
thereto. The compound or mixture of oxide of zinc and carbonate of
baryta thus obtained is white, and when mixed and ground in the usual
way with a drying oil may be used as white paint.
Where a lavender or brown colour has to be given to the paint the
calcined ores of tin or iron are mixed in the required proportions with
the materials described.
For the production of green, malachite or roasted copper ore is
employed, the tint being varied by the addition of manganese ore and
oxide of iron..
For the production of gray colour, calcined galena or lead and silver
lead ores are employed. These may be used in conjunction with zinc,
copper, tin, iron, and manganese ores, to produce the required shades of
gray.
By the use of baryta a peculiar glossy surface is given to the paint,
and the said baryta also effects such rapid drying of the paint that the
use of the dryers frequently required in paints of the ordinary kind is
not necessary.
Paints made according to my Invention are very economical, are very a
permanent in colour, and dry with great rapidity.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of January, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Argall, Her special
license that I, the said John Argall, my executors, administrators,
and assigns, or such others as I, the said John Argall, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF OIL PAINTS," upon the condition (amongst others)
that I, the said John Argall, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Argall, do hereby declare
the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
:-
In the ordinary manufacture of oil paints the colouring matters or
pigments are prepared by artificial chemical processes, and ground up
with drying oil either alone or mixed with artificially prepared carbonate
of lead or oxide of zinc, to give body or opacity to the paint.
In manufacturing oil paints according to my Invention I proceed as
herein-after described.
In order to give the required body or opacity to the paint I employ
as a basis the natural mineral consisting of carbonate of baryta and
zinc, or I use native zinc ore containing no carbonate of baryta. I
heat the said compound of zinc and baryta, or the zinc ore in con-
tact with air so as to effect what is commonly called the roasting of
the said ore, and its conversion when the zinc ore consists of a sulphide
into oxide of zinc. When the zinc ore contains no baryta I add car-
bonate of baryta thereto. The compound or mixture of oxide of zinc

page_text: and carbonate of baryta thus obtained is white, and when mixed and
ground in the usual way with a drying oil may be used as white paint.
Where a lavender or brown colour has to be given to the paint the
calcined ores of tin or iron are mixed in the required proportions with
the materials described.
For the production of green paint, malachite or roasted copper ore is
employed, the tint being varied by the addition of manganese ore and
oxide of iron.
For the production of gray colour, calcined galena or lead and silver
lead orcs are employed. These may be used in conjunction with zinc, 1
copper, tin, iron, and manganese ores, to produce the required shade of
gray.
By the use of baryta a peculiar glossy surface is given to the paint,
and the said baryta also effects such rapid drying of the paint that the
use of the dryers frequently required in paints of the ordinary kind is 1
not necessary.
Paints made according to my Invention are very economical, are very
permanent in colour, and dry with great rapidity.
The drying oil which I employ in manufacturing oil paints according
to my Invention is by preference the ordinary boiled linseed oil or 2
drying oil of commerce, but any other drying oil or vehicle suitable for
the manufacture of oil paints of the ordinary kind may be used in the
manufacture of oil paints according to my Invention.
Oil paints of the ordinary kind in which carbonate of lead is the basis
or material by which body or opacity is given to the paint are liable to 2
change of colour in consequence of the formation of sulphide of lead,
the presence of small quantities of sulphuretted hydrogen in the air, from
decomposing organic bodies from coal gas, and from other sources
yielding sulphur to the lead of the paint, and thus forming the dark
sulphide of lead.
Oil paints made according to my Invention are not liable to the
change of colour or darkening to which ordinary oil paints are liable, as
the baryta or oxide of zinc forming the basis of paints made.according to
my Invention are not darkened by sulphuretted hydrogen, and are
consequently very permanent.

page_text: Having now described the nature of my Invention, and the manner
in which the same is to be performed, I wish it to be understood that I
do not limit myself to the precise details herein described, as the same
may be varied without departing from the nature of my Invention,
but I claim as my Invention of improvements in the manufacture of
oil paints manufacturing oil paints by employing as a basis calcined
native carbonate of baryta and zinc, or native zinc ore with the addition
of carbonate of baryta ground and mixed with drying oil or other like
vehicle, the oil paint thus produced being used alone or coloured by
admixture therewith of colouring matters, substantially as herein
described.
In witness whereof, I, the said John Argall, have hereunto sct
my hand and seal, this Thirtieth day of June, in the year of
our Lord One thousand eight hundred and seventy-three.
Witness,
GEORGE SHAw.
JOHN ARGALL. (L.S.)