Year: 1898

page_text: :
We, ERNEST EDWARD MUNRO PAYNE, of Aylesbury, in the County of Buckingham,
Analytical Chemist, JOHN PULLMAN, Manufacturer, and EDWARD ENGLAND PULL-
MAN, Manufacturer, both of 17, Greek Street, Soho Square, in the County of
Middlesex, do hereby declare the nature of this invention to be as follows:-
.
This invention consists in a novel process of forming leather from skins, furs,
hides, pelts, or parts thereof prepared in certain manners, by the action of certain
chemicals in various conditions of mixture, or chemical combination; or both.
We are well aware that in certain processes of leather dressing the action of one
of the chemicals which we employ in the present invention is well known, that is
to say, formic aldehyde (CH,O), which it has been proposed to use in such processes,
but the present invention consists generally in using the said formic aldehyde in
combination with certain other substances.
The present invention consists in the formation of leather by means of the action
of certain compounds of formic aldehyde, and of other aldehydes, with other
materials, singly or mixed, upon the fibrous tissue of skins, furs, hides, pelts, or
parts thereof, which leather cannot be produced by the action of these aldehydes
alone upon the said skins, furs, hides, pelts, or parts thereof.
Moreover, certain aldehydes, other than formic aldehyde, in their pure state
have not up to the present time been used in the preparation of leather upon a
commercial or manufacturing scale, and a part of the present invention relates
to the use of these aldehydes, other than formic aldehyde, in conjunction with each
other, or in combination or admixture with other chemical substances. For
example, we make use of acetaldehydes, acrylic aldehyde (acrolein) and various
other known aldehydes or their polymers, each one producing a different chemical
combination but at the same time of commercial value in the production of
leather, some being of a white and others of other colours.
In carrying out the invention, there are many details to be observed in the
preparation of the skins, furs, hides, pelts, or parts thereof, which are capable of
great variations in order to obtain those results which are required for commercial
purposes; but we will now proceed to give some few examples in detail of the
manner in which the invention may be carried out, adding an outline of its general
application in the art of leather dressing.
Our invention is also applicable to skins, furs, hides, pelts, or portions thereof
which are already in certain states of combination as leather, either partly or

page_text: completely, or which are intended to be treated by some other known process of
leather dressing or dyeing, colouring, etc., such as are known in the art as tan-
ning, tawing, chroming, oil dressing, dyeing and colouring.
We do not confine ourselves to any special kind of machinery or apparatus
employed in carrying out the invention, but we find that the ordinary revolving
drum of about 300 gallons capacity, and the ordinary paddle of about the same
capacity, are suitable, and in them good commercial results may be obtained.
As an example of the manner in which we employ the compound or mixture of
formic aldehyde with other substances, or their combined action, we give the
following:-
We take 4 cwt. or thereabouts, of skin, fur, hides, pelts, or portions thereof
prepared by suitable washing, liming, bateing, puring, or drenching, and we
insert them into a closed revolving drum containing from 100 to 120 gallons of
water (preferably distilled, though ordinary water will suffice), at a temperature
of about 100 degrees Fahrenheit. In successive quantities we then add a mixture
of formic aldehyde (CHO) in aqueous solution of 30% or stronger, and sodium
carbonate (Na003) made in about the following proportions, and which we term
"dressing liquor."
Formic aldehyde (containing 36% CH₂O) about 16 lbs.
Sodium carbonate (80% NaCO3) about 32 lbs.
Water (preferably distilled,) a sufficiency; that is to say, from 10 to 15 gallons
or even less may be used, so that a perfect solution or combination is formed. This
solution or dressing liquor is added to the contents of the drum whilst still revolv-
ing, in quantities varying from one or more gallons at a time at intervals of fifteen
or more minutes, it being essential that the whole be not added at once, in which
case the result produced is not so good commercially.
According to the thickness and receptive power of the material operated upon,
the time varies as to the length of time required to produce the 'most perfect
results. For light goods from three to six hours is sufficient, and for heavy goods
from twelve to forty-eight hours, but we do not confine ourselves to any precise
length of time.
When the goods are showing leather to a sufficient extent we find it advan-
tageous to increase the temperature to about 118 degrees Fahrenheit,-
-a better
loosening of the fatty matter contained in the materials operated upon, and a more
even result, being then obtained.
Having obtained the goods in this condition, we find that the alkali, alkaline
carbonate, or alkaline earth is retained ultimately by the material, and if allowed
to remain therein is detrimental to the strength of the finished product.
In order to remove this alkali, alkaline carbonate, or alkaline earth, we submit
the goods, in a revolving drum or paddle, to the action of a suitable chemical in
solution, preferably ammonium sulphate (NH4)2SO4, of 95 %, in the proportion
of about 16lbs. dissolved in about 100 or 120 gallons of water, preferably distilled,
at a temperature of about 100 to 120 degrees Fahrenheit.
The goods are then withdrawn and inserted, paddled, or drummed and
nourished, in a solution of soft soap 10 lbs. (commercial soft soap, containing
about 66% potassium soap, we find answers well), and common salt, or chloride
of sodium 10 lbs., or in approximate proportion, dissolved in about 80 gallons of
water preferably distilled, for a longer or shorter time, about three hours being
found sufficient for light goods, and about six hours for heavy goods. The goods
may then be dried forthwith and finished.
Having now described the manner in which the compound or admixture of CH₂O
(formic aldehyde) with Na2CO3 (sodium carbonate) may be used, and a result pro-
duced totally different from that which can be obtained by the use of formic
aldehyde alone, we will mention some of the other aldehydes, and other chemicals.
or substances which may be used to obtain other results in combination.
In each case we take the molecular weight of the chemicals employed and keep
i

page_text: the respective amounts used about chemically proportionate to those already
mentioned.
Acrolein (acrylic aldehyde),
Aldehydes Acetaldehyde (ordinary aldehyde),
Propionic aldehydes and other aldehydes and their polymers,
Fixed alkaline carbonates,
"
alkaline hydrates,
weak alkaline compounds such as saponaceous and other
compounds of alkaline constitution."
The alkaline earths in state of oxide or hydrate, for example CaO (oxide of
calcium), Ca2 (HO) (hydrate of calcium), Mg (oxide of magnesium), Mg2 (HO)
(Hydrate of Magnesium) and other suitable salts. Or, these salts produced within
the material itself by metathesis, such as magnesium hydrate Mg2 (HO) produced
by the action of NaHO (caustic soda), upon MgCl, (magnesium chloride).
Aldehydes may also be used for treating what are known as alum and salt
leather, thereby rendering it less likely to be affected by water or moisture.
Dated this 4th-day of: February 1898.
Improvements in the process of Leather manufacture
We, ERNEST EDWARD MUNRO PAYNE, of Aylesbury, in the County of Buckingham,
Analytical Chemist, JOHN PULLMAN, Manufacturer, and EDWARD ENGLAND PULL-
MAN, Manufacturer, both of 17, Greek Street,, Soho Square, in the County of
Middlesex, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly ascertained in and by the following
statement, that is to say:
-
This invention consists in novel improvements in the process of forming leather
from skins, furs, hides, pelts, or parts thereof, prepared in certain manners, by
the action of certain chemicals, in various conditions of mixture, or chemical
combination, or both.
We are well aware that in certain processes of leather dressing or manufacture
the action of one of the chemicals which we employ in the present invention is
well known, that is to say, formic aldehyde (CHO), which it has been proposed
to use in such processes, but the present invention consists essentially in using the
said formic aldehyde (or in some cases other aldehydes) in combination with
certain other substances; so as to effect the formation of leather by means of the
action of certain compounds of formic aldehyde, and of other aldehydes, together
with other materials, such as alkaline carbonates, alkaline hydrates, saponaceous
or other alkaline compounds and alkaline earths, singly or mixed, upon the fibrous
tissue of skins, furs, hides, pelts, or parts thereof, which leather cannot be pro-
duced by the action of these aldehydes alone upon the said skins, furs, hides, pelts,
or parts thereof.
Moreover, certain aldehydes, other than formic aldehyde, in their pure state,
have not up to the present time been used in the preparation of leather and a

page_text: part of the present invention relates to the use of these aldehydes, other than
formic aldehyde, in conjunction with each other, or in combination or admixture
with other chemical substances. For example, we make use of acetaldehydes,
acrylic aldehyde (acrolein), and various other known aldehydes or their polymers,
each one producing a different chemical combination, but at the same time of
commercial value in the production of leather, some being of a white and others
of other colours.
In carrying out the invention there are many details to be observed in the
preparation of the skins, furs, hides, pelts, or parts thereof, which are capable of
great variations in order to obtain those results which are required for commercial
purposes; but we will now proceed to give some few examples in detail of the
manner in which the invention may be carried out, adding an outline of its general
application in the art of leather dressing, or manufacture.
Our invention is also applicable to skins, furs, hides, pelts, or portions thereof
which are already in certain states of manufacture as leather, either partly or
completely, or which are intended to be treated by some other known process of
leather dressing or dyeing, colouring, etc., such as are known in the art as tan-
ning, tawing, chroming, oil dressing, dyeing and colouring.
We do not confine ourselves to any special kind of machinery or apparatus to be
employed in carrying out the invention, but we find that the ordinary revolving
drum of about 300 gallons capacity, and the ordinary paddle of about the same
capacity, are suitable, and in them good commercial results may be obtained.
As an example of the manner in which we employ the compound or mixture of
formic aldehyde with other substances, or their combined action, we give the
following:-
We take 4 cwt. or thereabouts of skin, fur, hides, pelts, or portions thereof,
prepared in the well-known ways by suitable washing, liming, bateing, puiring or
drenching, and we treat them in a closed revolving drum containing from 100 to
120 gallons of water (preferably distilled, though ordinary water will suffice), at
a temperature of about 100 degrees Fahrenheit.. In successive quantities we then
add a mixture of formic aldehyde (CH₂O) in aqueous solution of 30 per cent or
stronger, and sodium carbonate (NaCO3) the mixture being made in about the
following proportions, and being termed by us dressing liquor";
Formic aldehyde (containing 36 % CH₂O) about 16 lbs.
Sodium carbonate (80% NaCO3) about 32 lbs..
<
Water (preferably distilled), a sufficiency:-that is to say, from 10 to 15 gallons,
or even less, may be used, so long as a perfect solution or combination is formed.
This solution or dressing liquor is added to the contents of the drum whilst still
revolving, in quantities varying from one or more gallons at a time at intervals
of fifteen or more minutes, it being essential that the whole be not added at once,
in which case the result produced would be not so good commercially.
According to the thickness and receptive power of the material operated upon,
the length of time varies which is required to produce the most perfect results.
For light goods, from three to six hours is sufficient, and for heavy goods from
twelve to forty-eight hours, but we do not confine ourselves to any precise length.
of time:
When the goods are showing leather to a sufficient extent, we find it advan-
tageous to increase the temperature to about 118 degrees Fahrenheit,-a better
loosening of the fatty matter contained in the materials operated upon, and a more
even result, being thus obtained.
-
.
Having obtained the goods in this condition, we find that the sodium carbonate,
(or other alkali, alkaline carbonate, or alkaline earth), is retained ultimately by
the material, and if allowed to remain therein in a free state would be detrimental
to the strength of the finished product.
In order to remove or fix this free alkali, alkaline carbonate, or alkaline earth,
we submit the goods, in a revolving drum or paddle, to the action of a suitable

page_text: acid, or chemical in solution, preferably ammonium sulphate ((NH4)2SO4) of
95 per cent., in the proportion of about 16 lbs., dissolved in about 100 or 120 gallons
of water, preferably distilled, at a temperature of about 100 to 120 degrees
Fahrenheit.
The goods are then withdrawn and inserted, paddled, or drummed and nourished,
in a solution of soft soap, 10 lbs. (commercial soft soap, containing about 66 per
cent. potassium soap, we find answers well), and common salt, or chloride of
sodium, 10 lbs., or in approximate proportion, dissolved in about 80 gallons of
water, preferably distilled, for a longer or shorter time;-about three hours being
found sufficient for light goods, and about six hours for heavy goods. The goods
may then be dried forthwith and finished.
Having now described the manner in which the compound or mixture of CH₂O
(formic aldehyde) with Na,CO, (sodium carbonate) may be used, and a result pro-
duced totally different from that which can be obtained by the use of formic
aldehyde alone, we will mention some of the other aldehydes, and other chemicals
or substances which may be used to obtain other results in combination.
In each case we take the molecular weight of the chemicals employed and keep
the respective amounts used about chemically proportionate to those already
mentioned.

page_text: acetaldehyde, (CHO); propionic aldehydes and other aldehydes and their poly-
mers, substantially as described and specified.
3. In the composition of the mixtures described and claimed in Claims 1
and 2, the substitution for sodium carbonate of other fixed alkaline carbonates,
alkaline-hydrates, weak alkaline compounds such as saponaceous and other com-
pounds of alkaline constitution, or alkaline earths such as oxide of calcium, hydrate
of calcium, oxide of magnesium, and hydrate of magnesium, substantially as
described.
4.—In the mixtures described in Claims 2 and 3, the method of producing the
alkaline earths by the action of the necessary component parts upon each other
within the material itself, substantially as described.
5. In the processes described, and claimed in Claims 1, 2, 3, and 4, the method
of removing the alkali, alkaline carbonate, or alkaline earth, remaining in the
materials treated, by means of a solution of ammonium sulphate, or equivalent
substance having a like action, substantially as described.
6. The use in combination with substances containing tannin ordinarily used
in tanning, of aldehyde or aldehydes, together with sodium carbonate, or other
fixed alkaline carbonates, alkaline hydrates, weak alkaline compounds such as
saponaceous and other compounds of alkaline constitution, or alkaline earths such
as oxide of calcium, hydrate of calcium, oxide of magnesium, and hydrate of
magnesium, substantially as described.
The use in combination with chrome compounds, ordinarily used in what
is well known as chrome tanning, of aldehyde or aldehydes, together with sodium
carbonate, or other fixed alkaline carbonates, alkaline hydrates, weak alkaline
compounds such as saponaceous and other compounds of alkaline constitution, or
alkaline earths such as oxide of calcium, hydrate of calcium, oxide of magnesium,
and hydrate of magnesium, substantially as described.
8. The use in combination with substances containing tannin ordinarily used
in tanning, together with chrome compounds ordinarily used in chrome tanning,
of aldehyde or aldehydes, together with sodium carbonate, of, other fixed alkaline
_carbonates, alkaline hydrates, weak alkaline compounds such as saponaceous and
other compounds of alkaline constitution, or alkaline earths such as oxide of
calcium, hydrate of calcium, oxide of magnesium, and hydrate of magnesium,
substantially as described.
9. The use, for treating what are known as
"alum" or "salt" leathers, of
aldehyde or aldehydes, together with sodium carbonate, or other fixed alkaline car-
bonates, alkaline hydrates, weak alkaline compounds such as saponaceous and
other compounds of alkaline constitution, or alkaline earths such as oxide of
calcium, hydrate of calcium, oxide of magnesium, and hydrate of magnesium,
substantially as described.
1
1
בד
1
1000
EDWARDS AND CO.,
Chartered Patent Agents,
65 and 66, Chancery Lane, London, Agents for the Applicants.