Improvements in the Manufacture of Glazes, Enamels, and the like.
Year: 1893

page_text: Date of Application, 13th May, 1893
Complete Specification Left, 7th Feb., 1894-Accepted, 17th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Glazes, Enamels, and
the like.
A communication by GEORGE LEUCHS and Dr. CHARLES LEUCHS, both of
Nuremberg, Bavaria, in the Empire of Germany.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E. of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6 Bank Street,
Manchester, both in the County of Lancaster, and 323 High Holborn in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this invention
to be as follows:-
The mineral rutile (titanic acid) has hitherto only been used in very small
quantities for producing a yellow colour on pottery ware.
This yellowish colour is caused partly by the iron and chrome, which are always
to be found in rutile, and partly by lower oxides of titanium if the pottery be
burned in a reducing atmosphere.
Now Messrs. Leuchs have found that titanic acid can replace a certain part of
silicic acid in glazes and that these glazes are not coloured if the batch is free of
colouring oxides and is melted in an oxydating atmosphere.
The titanic glazes have the following qualities-
1. They are easier of fusion than glazes containing only the equivalent of silicic
acid.
2. They are much more resistant to the decomposing action of humidity and
acids than the corresponding silicic glazes, even if they contain only few molecules
of silicic acid.
It is for example possible to produce glazes containing only one molecule of
titanic and two molecules of silicic acid, which will even then resist acids.
Such glazes combine the qualities of glazes containing a large amount of silicic
acid as well as of those which contain only little silicic acid or boracic acid or
fluorides or lead. They are as resistant to the acids as the former are, they melt
as easily and run as well as the latter ones. Besides that they have a great specific
gravity, co-efficient of dilatation and refraction and lustre. It is also possible to
produce titanic glazes containing boracic acid, fluorides or lead either separately or
in combination. Such glazes possess the properties produced by each of the
mentioned materials in a high degree.
There is a further quality of titanic acid and that is it will produce dulled glazes
(enamels) by employing it in a considerable quantity.
It can therefore be used as a substitute for peroxide of tin, phosphates and
fluorides, hitherto used for that purpose, but it can also be employed in combination
with them.
To enamel metals, only such glazes can be employed which have a co-efficient of
dilatation not too different from that of metals, that is glazes, containing only few
molecules of silicic acid and therefore not very resistant to acids. Owing to its
above mentioned qualities, titanic acid is rendered especially adaptable for glazes
of this kind.
Titanic acid can be used for all kinds of glazes, glazings, vitrifiable colours and
enamels, for the imitation of pearls, amber, diamonds and other jewels.
There should be used pure titanic acid or titanic alkali or rutile or any titanic
mineral which can be purified in any known way from colouring oxides, if it be

page_text: To obtain transparent glazes there is melted for example-
15-30 nitrate of soda, 116 soda, 33-50 carbonate of lime, 60-360 quartz,
62-83 boracic acid, 20-80 titanic acid,
Or,
15-30 nitrate of soda, 116 soda, 100 carbonate of lime, 240-360 quartz,
20-80 titanic acid.
To obtain enamels―
15-30 nitrate of soda, 116 soda, 100 carbonate of lime, 60-180 silicic acid,
80 titanic acid,
Or,
15-30 nitrate of soda, 116 soda, 33-50 carbonate of lime, 30-180 silicic acid,
60-83 boracic acid, 80-160 titanic acid.
In these compositions there can be substituted wholly or partly—
Soda by potash, calcium by aluminium, barium strontium, magnesium, zinc,
bismuth, antimony, thallium, lead, and if coloured glazes are desired, by cobalt,
nickel, chromium, iron manganese, copper, uranium.
Dated this 12th day of May 1893
WM. P. THOMPSON & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Glazes, Enamels, and
the like.
A communication by GEORGE LEUCHS and Dr. CHARLES LEUCHS, both of
No. 26, Obstmarkt, Nuremberg, Bavaria, in the Empire of Germany,
Chemists.
I, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for
Foreign Patent Solicitors 6, Lord Street, Liverpool and 6, Bank Street Manchester
both in the County of Lancaster and 323 High Holborn in the County of Middlesex
Civil 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 :-
The mineral rutile (titanic acid) has hitherto only been used in very small
quantities for producing a yellow colour on pottery ware.
This yellowish colour is caused partly by the iron and chrome which are always
to be found in rutile, and partly by lower oxides of titanium if the pottery be
burned in a reducing atmosphere.
Now Messrs. Leuchs have found that titanic acid can replace a certain part of
silicic acid in glazes and that these glazes are not coloured if the batch is free of
colouring oxides and is melted in an oxydating atmosphere.
The titanic glazes have the following qualities—
1. They are easier of fusion than glazes containing only the equivalent of
silicic acid.
2. They are much more resistant to the decomposing action of humidity and acids
than the corresponding silicic glazes, even if they contain only few molecules of
silicic acid.
It is, for example, possible to produce glazes containing only one molecule of
titanic and two molecules of silicic acid, which will even then resist acids.
Such glazes combine the qualities of glazes containing a large amount of silicic
acid as well as of those which contain only little silicic acid or boracic acid or fluorides
or lead. They are as resistant to the acids as the former are, they melt as easily
and run as well as the latter ones. Besides that they have a great specific gravity,
co-efficient of dilatation and refraction and lustre. It is also possible to produce

page_text: titanic glazes containing boracic acid, fluorides or lead either separately or in
combination. Such glazes possess the properties produced by each of the mentioned
materials in a high degree.
There is a further quality of titanic acid and that is it will produce dulled
glazes (enamels) by employing it in a considerable quantity.
It can therefore be used as a substitute for peroxide of tin, phosphates and
fluorides, hitherto used for that purpose, but it can also be employed in combination
with them.
To enamel metals, only such glazes can be employed which have a co-efficient of
dilatation not too different from that of metals, that is glazes, containing only few
molecules of silicic acid and therefore not very resistant to acids. Owing to its
above mentioned qualities, titanic acid is rendered especially adaptable for glazes
of this kind.
In order to cover iron articles with an enamel which does not chip off easily, one
can only use a so called ground or foundation enamel, which is poor in silicic acid.
The expansion of such an enamel is very nearly equal that of iron, and, therefore,
the chipping is avoided. As the before mentioned ground-enamel contains so little
silicic acid, it cannot well withstand acids. To obtain goods which can be used for
all house and kitchen purposes, at least a second coat of enamel must be used,
which is richer in silicic acid and consequently more able to resist acids.
By replacing a part of the silicic acid by titanic acid, in accordance with the
present invention, it is possible to produce glaze-enamels which have a high power
of expansion, which are less susceptible to change of temperature and which resist
acids. In this manner, with a single coating it is possible to succeed in enamelling
iron goods which are fit for all purposes. If these enamels be burned slightly,
they get white or gray and opaque, but if burned in bigher heat, they get more or
less transparent, and, through the solution of iron, yellow till brown in colour.
The brightness of the iron and its structure then shines through this sort of enamel
in various changing golden coloured patterns.
Titanic acid can be used for all kinds of glazes, glazings, vitrifiable colours and
enamels, for the imitation of pearls, amber, diamonds and other jewels.
There should be used pure titanic acid or titanic alkali or rutile or any titanic
mineral which can be purified in any known way from colouring oxides, if it be
necessary.
To obtain transparent glazes there is melted for example-
15-30 nitrate of soda, 116 soda, 33-50 carbonate of lime, 60-360 quartz,
62-83 boracic acid, 20-80 titanic acid,
Or,
15-30 nitrate of soda, 116 soda, 100 carbonate of lime, 240-360 quartz,
20-80 titanic acid.
To obtain enamels-
15-30 nitrate of soda, 116 soda, 100 carbonate of lime, 60-180 silicic acid,
80 titanic acid,
Or,
15-30 nitrate of soda, 116 soda, 33-50 carbonate of lime, 30-180 silicic acid,
60-83 boracic acid, 80-160 titanic acid.
In these compositions there can be substituted wholly or partly-
Soda by potash, calcium by aluminium, barium, strontium, magnesium, zinc,
bismuth, antimony, thallium, lead, and, if coloured glazes are desired, by cobalt,
nickel, chromium, iron manganese, copper, uranium.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, I declare that what I claim is-
1. In the manufacture or production of glazes, enamels, and the like, the use of
titanic acid as an important ingredient, substantially as and for the purposes
herein before set forth.

page_text: 2. In the manufacture or production of glazes, enamels and the like, the partial
-substitution of titanic acid for silicic acid substantially as and for the purposes
herein before set forth.
3. In the enamelling of iron goods and the like, the use of titanic acid as an
important ingredient whereby only one coating and one burning are necessary,
substantially as described.
Dated this 6th dow of Fahmi 1001
WM. P. THOMPSON & Co.,
Agents.