Improvements in Materials for and in the Manufacture of Soft Soap.
Year: 1894

page_text: Date of Application, 22nd Oct., 1894
Complete Specification Left, 15th Aug., 1895-Accepted, 21st Sept., 1895
PROVISIONAL SPECIFICATION.
Improvements in Materials for and in the Manufacture of
Soft Soap.
I, MARTIN PERLS of 62 and 63 Basinghall Street in the City of London,
Chemical and Colour Merchant, do hereby declare the nature of this invention to
be as follows:-
In the manufacture of soft soap at the present time a considerable percentage
of carbonate of potash has to be added with the caustic potash, in order to produce
the best results. In the manufacture of caustic potash, there always is a quantity
of chloride of potassium left in the material, but the efforts of the manufacturers
bave always been directed so as to leave as little as possible of chloride of
potassium in the caustic potash. Now I have found on the contrary that if from
20 to 40% of chloride of potassium be added to the caustic potash with or without
carbonate of potash and the mixture be used for soap making very much more
economical results are obtained. In carrying out my invention, 'I prefer to form
a mixture of carbonate of potash and caustic potash by stopping the causticising
process at the right point to obtain this particular mixture, I then add the chloride
of potassium. The chloride of potassium may also be formed in other ways, even
in the causticiser itself, such as by adding chloride of calcium and sulphate of
potash to the solution, the result is a precipitate of sulphate of lime leaving the
chloride of potassium in the liquor. The chloride of potassium may also be 'left
in, in the required quantity when making carbonate of potash from Stassfurt salts.
I may also in some instances add other chlorides such as chloride of magnesium or
of lime in small quantities; I prefer to make the mixture of salts first, as an
ingredient for making soft soap. In this way the salts can be produced in Germany
where chloride of potassium is abundant, and the soap made in England, in such a
case the salts are formed with as little water as possible and are exported in a
solid state, they may either be chloride of potassium and caustic potash only,
chloride of potassium, carbonate of potash and caustic potash. or even a mixture
of carbonate of potash and caustic potash formed by stopping the causticising
process part way with the small percentage of chloride of potassium, generally, left
after manufacturing caustic potash. or a larger percentage left designedly.
In the manufacture of soft soap I may either add the various salts to the boiling
fatty matter and water or all the solid mixed salt or salts above described or a
solution thereof.
lions
WM. P. THOMPSON & Co.,
Of:6 Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Materials for and in the Manufacture of
Soft Soap.
I, MARTIN PERLS, of .62, Basinghall Street, London, E.C., Merchant, 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 :-
In the manufacture of soft soap as at present conducted, the oil or fatty material

page_text: is subjected to prolonged boiling in a suitable vessel together with a lye composed
essentially of a potash solution together with certain other materials. The usual
mixture hitherto employed for the preparation of the lye, consists of carbonate of
potash and caustic potash in suitable proportions. There is always also present
some small proportion of chloride of potassium as such is contained in the raw
materials from which the carbonate and caustic potashes have been originally
derived. But as this salt has always hitherto been regarded as useless; if not
injurious for the purpose of the soap boiler, the efforts of the manufacturers have
hitherto been directed so as to leave as little as possible of chloride of potassium
in the caustic or respectively in the carbonate of potash. Now I have discovered,
that if a caustic lye containing from 15% to 40% of chloride of potassium be
used for the purpose above stated with or without the admixture of carbonate of
potash, very much more economical results are obtained.
The presence of the chloride of potassium is obtainable in various ways.
It may firstly be secured by only partially decomposing the original salts, from
which the carbonate, and subsequently the caustic potash is manufactured, thereby
leaving the requisite quantity of chloride of potassium in the material. The
exact percentage of material left in in this manner is a matter not easy to control,
and usually prefer to add the requisite percentage of chloride of potassium to
the caustic potash in the following manner :-
The caustic potash having been produced in the usual manner in હૈ dilute
condition is then concentrated by boiling and the temperature gradually rising
until it reaches about 240° Centigrade, it is then allowed to stand in the capsule
or steam pan a certain time in order to admit of the impurities settling out, and
is then ready to be filled into the cylinders in the usual way. Before this is
done, the fixed quantity of chloride of potassium or of chloride of potassium
mixed with other salts as described lower down is added, preferably in small
quantities at a time, to the hot liquid during its flow into the cylinders or drums,
the contents of which are crutched at intervals (by hand and preferably by means
of an iron bar) thus ensuring a uniform distribution of chloride of potassium
throughout the mass. The chloride of potassium added in this manner should be
crystalline and as dry as possible. If this operation be carefully carried out the
uniform and satisfactory intermixture of the chloride of potassium with the caustic
potash is obtained. By this method of operation the combination of the salts
can be produced abroad where chloride of potassium is abundant and the soap
made in England, the compound being concentrated as solid as possible so as to
contain the minimum quantity of water. The compound salt may be either
chloride of potassium and caustic potash only, or chloride of potassium, carbonate
of potash and caustic potash, or even a mixture of carbonate of potash, and caustic
potash caused by stopping the causticising process part way with the small
percentage of chloride of potassium generally left after manufacturing caustic
potash or with a large percentage left therein designedly. It is obvious however
that a similar result might be obtained if thought desirable by adding a determined
quantity of solution of chloride of potassium to a caustic lye of suitable strength
immediately before, or during the boiling process with the fatty material, the
precise method of effecting the admixture of the salts being immaterial to the
principle of my invention, but I prefer first to make the mixture of the salts
described above so that it may be sent out by the works in a solid state and be
used as an ingredient for making soft soap.
A previously determined quantity of chloride of potassium or else a combination
of same and carbonate of potash may also be added to the caustic liquor either in
the boiling pan or in the capsule.
The chloride of potassium may also be formed in other ways, even in the
causticiser, itself, such as by adding chloride of calcium and sulphate of potash to
the caustic liquor, producing a precipitate of sulphate of lime and leaving chloride
of potassium in the solution. In certain other cases, I may also add other chlorides
such as chloride of magnesium or chloride of lime in small quantities.

page_text: Also when making carbonate of potash from Stassfort salts the chloride of
potassium may be left in the latter in the desired quantity or when making it from::
other raw materials be added to it and the product obtained in this way may be
used for the transformation into caustic potash.
The percentage of chloride of potassium or chloride of potassium combined
with such other salts as are most practically advantageous for the manufacture of
soft soap depend principally on the temperature of the atmosphere at the time of
the soap boiling operation, and vary according to the season. I find the limits
of this variation to be from about five sixths caustic potash to one sixth chloride
of potassium or the compound containing it in summer, and to about three quarter:
caustic potash and one quarter chloride of potassium or the compound containing
it in winter.
In the manufacture of soft soap, I may either add the various salts or a solution
thereof one after the other to the boiling fatty matter and water or all the solid
mixture, of the salts above described together, or a solution thereof.
In conclusion, I wish to point out that the sap nification of oil by means of a
compound lye of hydrate and of chloride of potassium is essentially a different
operation from that known as filling the soap, after the saponification is concluded
which has for its object to increase the weight or bulk of the mass by the addition
of cheaper materials not themselves detergents, and that whereas it has always
hitherto been supposed that soft soap could only be made with a lye composed of
a solution of carbonate of potash treated with lime or of hydrate of potassium
solution admixed with carbonate of potash, a salt about three times more valuable
than the chloride, I am able to produce an equally good or even better quality of
soap by saponifying with the special lye containing a large proportion of chloride
of potassium in the manner set forth in his Specification. In this case the chloride
of potassium is in no sense an adulterant, but an essential component part of the
lye and by this means I obtain a great economy over the ordinary cost of production,
producing a new and useful technical product, that is to say a soft soap saponified
by a compound lye of hydrate and of chloride of potassium.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, 1 declare that what
I claim is :-
1. The improved potash compound for the manufacture of soft soap substantially
as described.
2. In the manufacture of soft soap, the use of a lye prepared from caustic or
causticised potash containing from 15 to 40 per cent. of chloride of potassium or
chloride of potassium mixed with other salts substantially as described.
3. The improved process of manufacture of caustic potash for soft soap making
by adding to the concentrated or fused salts a definite percentage of chloride of
potassium in the dry state.
Dated this 15th day of August 1895.
W. P. THOMPSON & Co.,
31, High Holborn, London, W.C., Agents.