Improvements in the Manufacture and Production of Phthalic and Sulpho-phthalic Acids.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883) as allowed by
the decision of the Comptroller General of the 15th day of July, 1898.
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture and Production of Phthalic and
Sulpho-phthalic Acids.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Badische Anilin & Soda Fabrik of Lud-
wigshafen-on-thine, in the German Empire) to be as follows:-
This invention consists in the production of phthalic and sulpho-phthalic acids
by a new reaction based upon the oxidising action of sulphuric acid on naphthalene
and derivatives thereof and other bodies which contain the naphthalene nucleus, or
a nucleus derived therefrom.
It has long been known that by the treatment of naphthalene with sulphuric
acid, various sulpho-acids can be obtained but my foreign correspondents have
discovered that, under suitable conditions, namely at a high temperature, say about
200 degrees Centigrade or higher, the sulphuric acid acts in a different manner, it
splits the naphthalene nucleus and oxidizes in such a way that phthalic and sulpho-
phthalic acids are produced, some of the sulpho-phthalic acids appearing to be new
products.
The quantity of sulphuric acid used, and its strength, may be varied within
wide limits. Fuming acid and acid containing water can be used. My foreign
correspondents in some cases add metallic salts to the melt; sometimes it is
advisable to work under pressure, and in some cases relief of pressure is desirable.
Air, or superheated steam, may, if desired, be blown through the reaction melt.
In all cases mixed phthalic and sulpho-phthalic acids appear to form. The
proportions of the various acids present in the mixtures vary according to the
conditions observed. My foreign correspondents have discovered that if mercury
sulphate, or mercury itself, or the oxides, or compounds, thereof, be added to the
mixture of naphthalene and sulphuric acid, and if the treatment, at a high
temperature be continued, say about 300° Centigrade, or higher, till the sulphuric
acid is all distilled off, then a product is obtained which consists in the main of
phthalic acid. Probably sulpho-phthalic acids are first formed, and by the action
of the mercury sulphate, they are converted into phthalic acid, the sulphogroups
being eliminated.
Instead of naphthalene there can be used sulphoacids thereof the naphthols,
naphthylamines and nitro-naphthalenes and their sulphoucids, anthracine and

page_text: phenanthrene and other aromatic bodies whose nuclei contain the naphthalene
nucleus.
To further illustrate the nature of the invention I give the following examples,
but the invention is not restricted to these examples, and there are many other
ways of carrying it into practical effect. The parts are by weight.
nucleus.
To further illustrate the nature of the invention I give the following examples,
but the invention is not restricted to these examples, and there are many other
ways of carrying it into practical effect. The parts are by weight.
EXAMPLE 1.
PRODUCTION OF PHTHALIC ACID WITH BUT LITTLE ADMIXED SULPIO-
DERIVATIVES.
Mix together about one hundred parts of naphthalene, one thousand five hun-
dred parts of sulphuric acid, (mono-hydrate 100 per cent. H₂SO), and fifty parts of
mercury sulphate and warm the mixture till the napthalene dissolves. Next heat
the mixture further in a retort, or other vessel suitable for distilling. As the
temperature reaches about two hundred degrees Centigrade the commencement of
the oxidation is noticeable and it proceeds more rapidly at two hundred and fifty
degrees. The melt assumes a dark colour and sulphurous acid and carbonic acid
are eliminated.
Raise the temperature finally to three hundred degrees and
higher, and maintain the heat until the contents become solid, or viscous. Whilst
heating collect the distillate in a suitable receiver. This distillate consists of
sulphuric acid diluted with the water formed during the reaction and the phthalic
acid produced partly as anhydride, and some sulpho-phthalic acid. The phthalic
acid separates out, almost completely on cooling, and can be collected by filtering,
or by treatment in a centrifugal machine. The residue in the retort which con-
tains the mercury sulphate can be used again in another operation.
The following are instances of mixtures which can be similarly treated.
(a) 100 parts beta-naphthol dissolved in 300 parts of oleum (fuming sulphuric
acid) containing about twenty per cent. free sulphuric anhydride, and then added
to about 1000 parts monohydrate and 40 parts mercury nitrate.
(b) 100 parts naphthionic acid 1000 parts of concentrated sulphuric acid (con-
taining about 90 to 95 per cent. H₂SO,), 30 parts mercuric oxide."
(c) 100 parts phenanthrene 2000 parts monohydrate sulphuric acid, 20 parts
mercury.
EXAMPLE 2.
PRODUCTION OF SULPHO-PHTHALIC ACID AS MAIN PRODUCT.
Dissolve about one hundred parts naphthalene by stirring with three hundred
parts of oleum (fuming sulphuric acid) containing about 20 per cent. free
anhydride (SO). Then add about twelve hundred parts of concentrated sulphuric
acid containing about ninety five per cent. real acid H₂SO. Heat the resulting
acid melt for about ten hours at a temperature of say about two hundred and fifty
degrees Centigrade. A certain amount of phthalic acid distils off and can be
collected, the melt which usually assumes a red-brown colour contains the sulpho-
phthalic acids. Work up in the usual way adding barium or calcium, carbonato
to neutralise the melt and the salt of the new disulpho-phthalic acid can be obtained
as crystalline warts from water and can be used for identifying the product.
If in the above example a lower temperature say about 220° Centigrade be
Dissolve about one hundred parts naphthalene by stirring with three hundred
parts of oleum (fuming sulphuric acid) containing about 20 per cent. free
anhydride (SO). Then add about twelve hundred parts of concentrated sulphuric
acid containing about ninety five per cent. real acid H₂SO. Heat the resulting
acid melt for about ten hours at a temperature of say about two hundred and fifty
degrees Centigrade. A certain amount of phthalic acid distils off and can be
collected, the melt which usually assumes a red-brown colour contains the sulpho-
phthalic acids. Work up in the usual way adding barium or calcium, carbonato
to neutralise the melt and the salt of the new disulpho-phthalic acid can be obtained
as crystalline warts from water and can be used for identifying the product.
If in the above example a lower temperature say about 220° Centigrade be
applied a mono-sulpho-pathanc ac results.
Dated this 17th day of August 1896.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: COMPLETE SPECIFICATION (AMENDED).
Improvements in the Manufacture and Production of Phthalic and
Sulpho-phthalic Acids.
I JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman; do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Badische Anilin & Soda Fabrik of Lud-
wigshafen-on-Rhine, in the Empire of Germany) and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:-
This invention consists in the production of phthalic, and sulpho-phthalic, acids
by a new reaction based upon the oxidizing action of sulphuric acid on naphthalene
and derivatives thereof as hereinafter named.
It has long been known that by the treatment of naphthalene with sulphurio
acid, various sulphoncids can be obtained, but my foreign correspondents have
discovered that, under suitable conditions, namely at a high temperature, eay about
200 degrees Centigrade, or higher, the sulphuric acid acts in a different manner, it
splits the naphthalene nucleus and oxidizes in such a way that phthalic and sulpho-
phthalic acids are produced, some of the sulpho-phthalic acids appearing to be new
products.
The quantity of sulphuric acid used, and its strength, may be varied within
wide limits. Fuming acid, and acid containing water, can be used. My foreign
correspondents in some cases add metallic salts to the melt. Sometimes it is
advisable to work under pressure and in some cases relief of pressure is desirable.
Air, or super-heated steam, may, if desired, be blown through the reaction melt.
In all cases mixed phthalic and sulpho-phthalic acids appear to form. The
proportions of the various acids present in the mixtures vary according to the
conditions observed. My foreign correspondents have discovered that if mercury
sulphate, or mercury itself, or the oxides, or other compounds thereof be added to the
mixture of naphthalene and sulphuric acid, and if the treatment, at a high
temperature be continued, say about 300° Centigrade, or higher, till the sulphuric
acid is distilled off, then a product is obtained which consists in the main of
phthalic acid. Probably sulpho-phthalic acids are first formed and by the action of
the mercury or the compound of mercury they are converted into 'phthalic acid,
the sulpho groups being eliminated.
Instead of naphthalene, its sulphoacids the naphthols, naphthylamines and mono-
nitro naphthalenes and their sulphoacids and also anthracene and phenanthrene
can be used.
To further illustrate the nature of the invention and to explain the manner in
which it can be performed I give the following examples, but the invention is not
restricted to these examples and there are many other ways of carrying it into
practical effect. The parts are by weight.
EXAMPLE 1.
PRODUCTION OF PHTHALIC ACID WITH BUT LITTLE
DERIVATIVES.
ADMIX BD
SULPIO-
Mix together about one hundred parts of naphthalene, one thousand five hun-
dred parts of sulphuric acid (monohydrate 100 per cent. H₂SO) and fifty parts of
mercury sulphate, and warm the mixture till the naphthalene dissolves. Next heat
the mixture further in a retort, or other vessel suitable for distilling. As the
temperature reaches about two hundred degrees Centigrade the commencement of
the oxidation is noticeable and it proceeds more rapidly at two hundred and fifty
degrees. The melt assumes a dark colour and sulphurous acid and carbonic acid
are eliminated. Raise the temperature finally to three hundred degrees or
higher, and maintain the heat until the mass becomes solid, or viscous. Whilst

page_text: heating collect the distillate in a suitable receiver. This distillate consists of
sulphuric acid diluted with the water formed during the reaction; and the phthalic
acid produced, partly as anhydride, and some sulpho-phthalic acid. The phthalic
acid separates out almost completely on cooling, and can be collected by filtering,
or by treatment in a centrifugal machine. The residue in the retort which con-
tains the mercury sulphate can be used again in another operation.
The following are instances of mixtures which can be similarly treated.
(a) 100 parts beta-naphthol dissolved in 300 parts of oleum (fuming sulphuric
acid) containing about twenty per cent. free sulphuric anhydride, and then added
to about 1000 parts of monohydrate and 40 parts of mercury nitrate.
(b) 100 parts of naphthionic acid, 1000 parts of concentrated sulphuric acid (con-
taining about 90 to 95 per cent. H,SO) and 30 parts of mercuric oxide.
(c) 100 parts phenanthrene, 2000 parts of monohydrate sulphuric acid and 20
parts of mercury.
EXAMPLE 2.
PRODUCTION OF SULPHO-PHTHALIC ACID AS MAIN PRODUCT.
Dissolve about one hundred parts naphthalene by stirring with three hundred
parts of oleum (fuming sulphuric acid) containing about 20 per cent. free
anhydride (SO). Then add about twelve hundred parts of concentrated sulphuric
acid containing about ninety-five per cent. of real acid H₂SO. Heat the resulting
acid melt for about ten hours at a temperature of say about two hundred and fifty
degrees Centigrade. A certain amount of phthalio acid distils off and can be
collected, the melt, which usually assumes a red-brown colour, contains the sulpho-
phthalic acids. Work up in the usual way adding barium, or calcium, carbonate
to neutralize the melt.
If the crude barium salt be recrystallized from water the barium salt of a new
disulpho-phthalic acid can be isolated in the form of crystalline warts.
If, in the above example, a lower temperature, say about 220° Centigrade, be
applied a mono-sulpho-phthalic acid results.
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 what I
claim is:-
1. The manufacture of phthalic, or sulpho-phthalic acids, or mixtures thereof,
by heating naphthalene, or its derivatives, as herein before named, with sulphuric
acid at a temperature of, or exceeding, 200° Centigrade.
2. The manufacture of phthalic, or sulpho-phthalic acids, or mixtures thereof, by
heating naphthalene, or its derivatives, as hereinbefore named, with sulphuric acid
and with mercury, or a compound of mercury, at a temperature of, or exceeding,
200° Centigrade.
3. The manufacture of phthalic, or sulpho-phthalic acids, or mixtures thereof, by
heating naphthalene, or its derivatives as hereinbefore named, with sulphuric acid
and with mercury, or a compound of mercury, at a temperature of 300° Centigrade
or higher as hereinbefore explained.
4. The manufacture of phthalic acid in the manner described in the foregoing
Example 1.
5. The manufacture of sulpho-phthalic acids in the manner described in the
foregoing Example 2.
LOOM
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.