IMPROVEMENTS IN THE MANUFACTURE OF LACTIC ACID; AND THE LACTATES, AND OF A MORDANT DERIVED CHIEFLY THEREFROM, FOR DYERS' USE.
Year: 1883

page_text: LETTERS PATENT to Alfred George Brookes of No 59 Chancery Lane in
the County of Middlesex Fellow of the Institute of Patent Agents for an
Invention of IMPROVEMENTS IN THE MANUFACTURE OF LACTIC ACID; AND
THE LACTATES, AND OF A MORDANT DERIVED CHIEFLY THEREFROM, FOR
DYERS' USE. communicated to him from abroad by Thomas Shepard Nowell
of Boston, in the County of Suffolk and State of Massachusetts, one of the
United States of America, Manufacturer.
PROVISIONAL SPECIFICATION left by the said Alfred George Brookes at
the Office of the Commissioners of Patents on the 18th December 1883.
ALFRED GEORGE BROOKES of N° 59 Chancery Lane in the County of Middlesex
Fellow of the Institute of Patent Agents "IMPROVEMENTS IN THE MANUFACTURE
OF LACTIC ACID, AND THE LACTATES, AND OF A MORDANT DERIVED CHIEFLY
THEREFROM, FOR DYERS' USE" Communicated to me from Abroad by Thomas
Shepard Nowell of Boston, in the County of Suffolk and State of Massachusetts,
one of the United States of America, Manufacturer)
This invention consists of two parts; the first part of said invention relates to
the manufacture of lactic acid, and the lactates, and the second part relates to the
production of a mordant for fixing colors to animal and vegetable fibres, et cetera,
in the process of dyeing, of which mordant, the lactic acid formed by the described
process of the first part, constitutes the chief element.
The first step in the process is the production of neutral lactate crystals, and this
is effected in the following manner.
First, take any starch producing vegetable substance, such as the meal or flour,
of Indian corn, or Maize, for example, and add thereto warm water, (preferably
of a temperature between 40° and 45° centigrade, though it is not necessary
to be confined to these limits) using about 120 litres (30 gallons) of water to
45.5. kilogrammes (100 pounds) of the meal, in ordinary cases, though these
proportions are subject to variation and next add thereto say about 16 litres
Pming &dT

page_text: (4 gallons) of an active lactic ferment, which is about 10 per centum of the mass
of meal and water first mixed together, although more or less of the ferment may
be employed.
To this mixture is next added a substance to neutralise the lactic acid as fast as
formed. It is preferable to use carbonate of lime for this purpose, as this may be
added all at once, in the beginning of the process, but instead of this, other
neutralizing substances may be employed, but if a strongly alkaline neutralizing
substance is used, the said substance must be added cautiously, and gradually.
However, as stated, carbonate of lime is preferable in ordinary cases, inasmuch
as its action is gradual and continuous, and self regulating, and by its use the
necessity of repeated additions of the neutralizing substance is avoided. About one
half the quantity, by weight, of carbonate of lime, should be added to a given
quantity of the meal (for example about 22.75. kilogrammes (50 pounds) of the
former to the 45.5 kilogrammes (100 pounds) of the latter, named in the illustration)
or a chemically equivalent quantity of any other neutralizing substance employed.
The original temperature is substantially maintained throughout the entire process
of fermentation and neutralization just described
The resulting product of the described process (wherein carbonate of lime has
been named as the neutralizing substance employed) is a mass of neutral calcium
lactate crystals, and the manner in which marketable acid crystals are obtained
therefrom will next be described.
The neutral crystals are digested with hot water, and filtered, through any
convenient form of mechanical filter, and the liquid resulting from this filtration is
a dilute solution of neutral calcium lactate; to this solution is added sufficient
sulphuric acid to combine with one half of the lime which was previously
combined with the lactic acid; the lime thus withdrawn forms, with the sulphuric
acid, sulphate of lime next, again filter, and the resulting liquid is a dilute
solution of acid calcium lactate. This solution is then concentrated. After
concentration, the liquid is set in a cold chamber, never above 7.5°. centigrade
(45° Fahrenheit) and the acid calcium lactate crystallizes, substantially solid, the
slight amount of mother liquid still remaining with the crystals being readily
pressed out therefrom, and the acid crystals are now ready for use
The process has been herein before described with special reference to the use of
the meal or flour of Indian corn, or Maize, that being a cheap, and readily available
substance, but instead thereof, any amylaceous substance may be used. In case
pure starch is employed in the beginning of the process, instead of starch producing,
or starch containing substances, it is necessary to add thereto sufficient nitrogenous
matter to carry on the fermentation
Instead of using starch or starch producing substances as the source from whence
the lactic acid is obtained, it may be produced from dextrine, inuline, moss starch,
vegetable mucus, gum arabic, or other vegetable gums, having the same constitution
as dextrine; adding to the said dextrine, or other gum about 10 per centum of
vegetable albuminoid matter, as well as about four times the weight of this mixture
of water, in order to secure the necessary fermentation when the lactic ferment is
added thereto, as already described, and the described neutralizing substance
(preferably carbonate of lime in order to successfully produce lactic acid from
dextrine and analogous gums, it is necessary to prevent agitation of the mass
during fermentation, and thereby avoid butyric and other distinctive fermentation
which would otherwise decompose whatever lactate formed, and prevent further
formation of the lactic acid. The dextrine may be obtained from the meal or flour
of Indian Corn or Maize, if preferred, by boiling the latter with water acidified with
sulphuric acid, and neutralizing the latter, in which case, the required vegetable
albuminoid matter will be found present in the resulting product
By this process, as herein described, a perfect fermentation of the starch in the
meal, or other substances, may be obtained, as well as a much larger yield of acid
than when the starch is first converted into a vegetable sugar, thus overcoming the
loss in the yield of starch, occasioned by such conversion, in all the other known
'

page_text: processes, besides which, additional economy, both of time and expense, is secured
in the process of manufacture.
The second part of the invention relates to the production of a mordant, suitable
for dyers' use in the fixing of colors, in fabrics woven of animal or vegetable fibre,
and particularly adapted to wool, hair and silk fibres, and also to be used in the
dyeing of feathers et cetera, all as will be more fully set forth hereinafter.
Heretofore, tartaric and citric acids, and their neutral and acid salts, have been
largely employed as mordants for dyers' use and as a substitute for these, it has
been proposed to use lactic acid; but the action of this acid has been too feeble,
and it did not sufficiently open the pores of the fibres to permit the dye to
penetrate, and hence was comparatively valueless, unless used in large quantities,
and it then became too expensive for general use, besides requiring too great a
length of time for its action to be profitably employed. Other acids have been
experimented with, and used to some extent, such as the very strong acids, but the
great objection to their use lay in the fact that their action was much too powerful,
and these acids have greatly injured, and even destroyed the fibre subjected to their
influence, and bence dyers have generally fallen back upon tartaric acid, either
alone, or in combination with potash (in the form of cream of tartar,) as the most
valuable and effective mordant for ordinary use.
The mordant which forms the subject of the second part of this invention is
composed of lactic acid; derived from amylaceous substances in the manner already
described, at length, in the first part of this invention, mixed with oxalic acid, and
used either alone, as thus mixed, or in conjunction with some suitable metallic salt
(such as the salts of tin, iron, alumina, antimony, et cetera) in the proportion of
about four parts of the lactic acid to one part of the oxalic acid. These acids are
thoroughly mixed together, and then the feeble action of the former is quickened by
the latter, while the heretofore violent action of the latter is correspondingly
moderated by the former.
As stated this mordant is chiefly intended for use in connection with the fixing
of colors to animal fibres, and it effectually opens the pores thereof, quickly,
thoroughly, and without the least injury thereto, although it may be advantageously
employed with fabrics composed wholly or in part, of vegetable fibre, or wherever
a comparatively weak acid is essential to the successful fixing of the coloring
matter.
The special advantages of this mordant, composed of the mixed acids (and its
combinations) over the tartaric acid mordant, consist, first, in its greater cheapness;
secondly, its superior fastness to soap; and, thirdly, in the increased bloom, and
softness, which it gives to the dyed fibre.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent fileḍ
by the said Alfred George Brookes in the Patent Office on the 14th June
1884.
ALFRED GEORGE BROOKES of N° 59 Chancery Lane in the County of Middlesex
Fellow of the Institute of Patent Agents. "IMPROVEMENTS IN THE MANUFACTURE 5
OF LACTIC ACID, AND THE LACTATES, AND OF A MORDANT DERIVED CHIEFLY
THEREFROM FOR DYER'S USE (Communicated to me from abroad by Thomas
Shepard Nowell of Boston in the County of Suffolk and State of Massachusetts
one of the United States of America Manufacturer.)
"
This invention consists of two parts; the first part of said Invention relates to 1
the manufacture of lactic acid, and the lactates, and the second part relates to the
production of a mordant for fixing colors to animal and vegetable fibres, et cetera,
in the process of dyeing, of which mordant, the lactic acid formed by the described
process of the first part, constitutes the chief element.
The first step in the process is the production of neutral lactate crystals, and this 1
is effected in the following manner.
First, take any starch producing vegetable substance, such as the meal or flour,
of Indian Corn, or Maize, for example, and add thereto warm water, (preferably of
a temperature between 40° and 45° centigrade, though it is not necessary to be
confined to these limits) using about 120 litres, (30 gallons) of water to 45.5 2
kilogrammes (100 pounds) of the meal, in ordinary cases, though these proportions
are subject to variation, and next add thereto say about 16 Litres (4 gallons) of an
active lactic ferment, which is about 10 per centum of the mass of meal and water
first mixed together, although more or less of the ferment may be employed. To
this mixture is next added a substance to neutralize the lactic acid as fast as 2
formed. It is preferable to use carbonate of lime for this purpose, as this may
be added all at once, in the beginning of the process, but instead of this, other
neutralizing substances may be employed, but if a strongly alkaline neutralizing
substance is used, the said substance must be added cautiously, and gradually.
However as stated, carbonate of lime is preferable in ordinary cases, inasmuch as
its action is gradual and continuous, and self-regulating, and by its use the
necessity of repeated additions of the neutralizing substance is avoided.. About
one-half the quantity, by weight, of carbonate of lime, should be added to a given
quantity of the meal, (for example about 22-75 kilogrammes (50 pounds) of the
former to the 45-5 kilogrammes (100 pounds) of the latter, named in the illustration)
or a chemically equivalent quantity of any other neutralizing substance employed.
The original temperature is substantially maintained throughout the entire process
of fermentation and neutralization just described.
The resulting product of the described process (wherein carbonate of lime has
been named as the neutralizing substance employed) is a mass of neutral calcium
lactate crystals, and the manner in which marketable acid crystals are obtained
therefrom will next be described.
The neutral crystals are digested with hot water, and filtered, through any
convenient form of mechanical filter, and the liquid resulting from this filtration
is a dilute solution of neutral calcium lactate; to this solution is added sufficient
sulphuric acid to combine with one-half of the lime which was previously combined
with the lactic acid; the lime thus withdrawn, forms, with the sulphuric acid,
sulphate of lime; next, again filter, and the resulting liquid is a dilute solution of
acid calcium lactate. This solution is then concentrated. After concentration, the
liquid is set in a cold chamber, never above 7.5° centigrade (45° Fahrenheit) and
the acid calcium lactate crystallizes, substantially, solid, the slight amount of

page_text: mother liquor still remaining with the crystals being readily pressed out therefrom,
and the acid crystals are now ready for use.
The process has been hereinbefore described with special reference to the use
of the meal or flour of Indian Corn, or Maize, that being a cheap, and readily
available substance, but instead thereof, any amylaceous substance may be used.
In case pure starch is employed in the beginning of the process, instead of starch
producing, or starch containing substances, it is necessary to add thereto sufficient
nitrogenous matter to carry on the fermentation.
Instead of using starch or starch-producing substances as the source from whence
the lactic acid is obtained, it may be produced from dextrine; inuline, moss starcb,
vegetable mucus, gum arabic, or other vegetable gums having the same constitution
as dextrine; adding to the said dextrine, or other gum about ten per centum. of
vegetable albuminoid matter, as well as about four times the weight of this mixture
of water, in order to secure the necessary fermentation when the lactic ferment is
added thereto, as already described, and the described neutralizing substance
(preferably carbonate of lime) in order to successfully produce lactic acid from
dextrine, and analogous gums, it is necessary to prevent agitation of the mass
during fermentation, and thereby avoid butyric and other distinctive fermentations
which would otherwise decompose whatever lactate formed, and prevent further
formation of the lactic acid. The dextrine may be obtained from the meal or flour
of Indian Corn or Maize, if preferred, by boiling the latter with water acidified
with sulphuric acid, and neutralizing the latter, in which case, the required
vegetable albuminoid matter will be found present in the resulting product.
By this process, as herein described, a perfect fermentation of the starch in the
meal, or other substances, may be obtained, as well as a much larger yield of acid
thau when the starch is first converted into a vegetable sugar, thus overcoming
the loss in the yield of starch, occasioned by such conversion, in all the other
known processes, besides which, additional economy, both of time and expense, is
secured in the process of manufacture.
The second part of the invention relates to the production of a mordant suitable
for dyers' use in the fixing of colors, in fabrics woven of animal or vegetable fibre,
and particularly adapted to wool, hair and silk fibres and also to be used in the
dyeing of feathers, et cetera, all as will be more fully set forth hereinafter.
Heretofore, tartaric and citric acids, and their neutral and acid salts, have been
largely employed as mordants for dyers' use, and as a substitute for these, it has
been proposed to use lactic acid, but the action of this acid has been too feeble, and
it did not sufficiently open the pores of the fibres to permit the dye to penetrate,
and hence was comparatively valueless, unless used in large quantities, and it then
became too expensive for general use, besides requiring too great a length of time
for its action to be profitably employed. Other acids have been experimented
with, and used to some extent; such as the very strong acids, but the great
objection to their use lay in the fact that their action was much too powerful, and
these acids have greatly injured, and even destroyed the fibres subjected to their
influence, and hence dyers have generally fallen back upon tartaric acid, either
alone, or in combination with potash (in the form of cream of tartar,) as the most
valuable and effective mordant for ordinary use.
The mordant which forms the subject of the second part of this invention is
composed of lactic acid, derived from amylaceous substances in the manner already
described, at length, in the first part of this invention, mixed with oxalic acid, and
used, either alone, as thus mixed, or in conjunction with some suitable metallic
salt (such as the salts of tin, iron, alumina, antimony, et cetera,) in the proportion
of about four parts of the lactic acid to one part of the oxalic acid. These acids
are thoroughly mixed together, and then the feeble action of the former is
quickened by the latter, while the heretofore violent action of the latter is
correspondingly moderated by the former.
As stated, this mordant is chiefly intended for use in connection with the fixing
of colors to animal fibres, and it effectually opens the pores thereof, quickly,

page_text: thoroughly, and without the least injury thereto, although it may be advan-
tageously employed with fabrics composed wholly, or in part, of vegetable fibre,
or wherever a comparatively weak acid is essential to the successful fixing of
the coloring matter.
The special advantages of this mordant, composed of the mixed acids, (and its
combinations) over the tartaric acid mordant, consist, first, in its greater cheapness;
secondly, its superior fastness to soaps; and, thirdly, in the increased bloom, and
softness, which it gives to the dyed fibre.
Having thus described the nature of the said invention and means adapted for
carrying the same into practical effect I would have it understood that what
I claim is:
1st. The method of forming neutral lactate crystals, in the production of lactic acid
and the lactates, by the fermentation of a starch-containing or starch-producing
vegetable substance, in its original form, or by the fermentation of dextrine, or
other gums of vegetable origin, having the same constitution, in the presence of
water, and of an active lactic ferment, sufficiently charged with a substance to
neutralize the acid.
2nd The method of obtaining acid crystals from neutral calcium lactate crystals,
consisting in digesting the latter with hot water, mechanically filtering the solution;
adding sulphuric acid thereto again filtering, and concentrating the last solution,
and next setting the concentrated solution in a cold chamber to crystallize.
3rd A mordant for fixing the colors in fabrics woven of animal and vegetable
fibres, consisting of a mixture of about four parts of lactic acid, and one part of
oxalic acid.
In witness whereof I the said Alfred George Brookes have hereunto set my
hand and seal this fourteenth day of June in the year of our Lord One thousand
eight hundred and eighty four.
ALFRED G BROOKES (L.s.)