IMPROVEMENTS IN THE MANUFACTURE OF SOAP
Year: 1884

page_text: I CHARLES ROMLEY ALDER WRIGHT Doctor of Science, Consulting Chemist of
3 Castellain Road, Maida Vale in the County of Middlesex do hereby declare the
nature of my invention for "IMPROVEMENTS IN THE MANUFACTURE OF SOAP"
to be as follows:-
-
It is well known that water solutions of ammonia when used for washing or
cleansing purposes exert, much less injurious action on animal textures membranes
and fibres than equally strong solutions of the fixed alkalies potash and soda so that
such ammoniacal fluids are employed in many cases where the solutions of fixed
alkalies would be objectionable for instance in the woollen industries.
3
It is also well known that soaps prepared by the ordinary process in vogue for
that manufacture are liable to contain, and in many cases practically always do
contain, a considerable amount of fixed alkali in what is known as the "free" state,
that is not chemically combined with the fatty and resinous acids forming the basis
of the soap; and that the presence of this "free alkali" although useful and
beneficial for scouring and laundry purposes, is objectionable when the soap is
required for toilet purposes inasmuch as it causes the soap to act injuriously on the
skin causing roughness redness chapping and excoriation, more especially in the
case of infants and others naturally possessing tender skins.
I have found that these objectionable effects due to the presence of the fixed
alkalies potash or soda or of both jointly in the "free" state in soap may be greatly
diminished and in many cases wholly obviated by intermixing with the soap a
suitable quantity of a neutral salt of ammonia formed by the combination of
ammonia with a sufficiently strong acid and by preference with sulphuric or
hydrochloric acid the proportion requisite being for every 31 parts of anhydrous
soda or for every 47 parts of anhydrous potash, 66 parts of sulphate of ammonia or
53 parts of chloride of ammonium or such a quantity of any other neutral salt of
ammonia as will contain 17 parts of ammonia as is well understood by chemists.
The addition of a small excess of ammoniacal salt to the soap exerts no injurious
influence on the result but if less than the amount of ammoniacal salt just stated
bo added the whole of the alkalinity due to the free fixed alkalies in the soap will
not be removed but only a part of it in proportion to the quantity of ammoniacal

page_text: EE
In order to effect the intermixture of the ammoniacal salt with the soap to be
treated by this improved process I proceed as follows:-In the case of such soaps
as are manufactured by the process of "boiling" fatty and oily matters with
alkaline lyes and finally separating the soap thus formed by addition of common
salt or brine, I add to the nearly fluid soap thus separated and purified by standing
or otherwise the requisite quantity of ammoniacal salt either in the state of fine
powder or dissolved in as small a quantity of hot water as possible and then by
crutching" or other convenient mode of agitation intermix the whole thoroughly
together; after which the mixture is run into the moulds or frames to cool and
solidify as usual. During this operation the ammoniacal salt used and the free
fixed alkali in the soap react upon one another in such a fashion as to convert the
free fixed alkali into a neutral salt, for example into sulphate of soda if soda be the
alkali in the soap and if sulphate of ammonia be the ammoniacal salt added and
similarly in other cases: simultaneously a quantity of ammonia is liberated more
or less mixed with carbonate of ammonia according as the free alkali in the soap
originally employed was nearly all in the caustic state or was more or less in the
condition of carbonate. A considerable amount of the ammonia or carbonate of
ammonia thus liberated escapes during the stirring and intermixing the rest remains
for the time being in the soap but for the most part evaporates during the subsequent
operations of cutting up the cooled masses of soap and shaping drying and stamping
-the tablets or bars ultimately sent into the market; the minute quantity of
ammonia or carbonate of ammonia that is finally retained by the finished soap acts
far less injuriously on tender skins than an equal amount of either potash or soda
so that for all practical purposes the whole of the free alkali in the original soap is
neutralised by the treatment provided that the due proportion of ammoniacal salt
is used.
In the case of soap prepared by remelting whether consisting of one kind only or
of more than one variety blended together by melting, the ammoniacal salt may bo
added in fine powder or dissolved in as little water as possible to the soap either
previously to commencing to melt it by the proper application of heat or whilst the
melting operation is going on or when the melting is completed; in all cases
incorporating by agitation so as to produce thorough intermixture before finally
running the melted soap into the moulds or frames in which it is allowed to cool as
usual.
In the case of soaps prepared by so called "cold"
processes in which alkalino
lyes and fatty matters are incorporated together at a comparatively low temperaturo
and without actually boiling and separating the soap formed by means of brine or
salt, I add the ammoniacal salt to the mass at as late a period as possible when the
saponifying action of the alkali on the fatty matter is practically completed, mixing
the whole thoroughly together and then allowing the inass to stand for the purposo
of solidifying as usual.
In the caso of soaps prepared at the ordinary temperature or but little above it
by grinding together in a soap mill the soap forming the basis of the material
intimately made with colouring matters perfumes & I add to the soap cut into
slices or shavings as usual the requisite quantity of ammoniacal salt either in fino
powder or dissolved in as small a quantity of water as possible before commencing to
grind, and then grind the mass together passing it back and forth through the mill
as many times as may be judged necessary to cause the spontaneous evaporation
and escape of any desired proportion of the ammonia or carbonate of ammonia
formed by the action of the ammoniacal salt on the free alkali contained in the
soap after which I add the colouring matters and perfumes and proceed as usual to
incorporate them with tho mass. In some cases especially when the soap contains
but little free alkali, the incorporation of the colouring matters and perfumes may
be effected simultaneously with that of the ammoniacal salt.
In all cases the end result of this improved process for preparing soaps more
especially toilet soaps is that if the due proportion of ammoniacal salt be used the
free fixed alkali contained in the soap is destroyed as such being converted into a

page_text: neutral salt; whilst of the equivalent quantity of ammonia generated during this
neutralization of fixed alkali the great majority escapes either at once or during
the subsequent operations gone through in preparing the soap for sale whilst the
amall residual quantity which does not thus escape is practically devoid of injurious
5-action on tender skins; so that for all practical purposes a complete removal of free
alkali from the soap is effected.
Hated this 6th day of November 1884.
CARPMAEL & Co.,
Agents for the Applicant.
"
I CHARLES ROMLEY ALDER WRIGHT Doctor of Science, Consulting Chemist of
3 Castellain Road, Maida Vale, in the County of Middlesex do hereby declare the
"und
IMPROVEMENTS IN THE MANUFACTURE OF SOAP
nature of my invention for
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:—
It is well known that watery solutions of ammonia when used for washing or
cleansing purposes exert much less injurious action on animal textures, membranes
and fibres than equally strong solutions of the fixed alkalies potash and soda so
that such ammoniacal fluids are employed in many cases where the solutions of
fixed alkalies would be objectionable for instance in the woollen industries.
It is also well known that soaps prepared by the ordinary processes in vogue for
that manufacture are liable to contain, and in many cases practically always do
contain a considerable amount of fixed alkali in what is known as the "free" state,
that is to say not chemically combined with the fatty and resinous acids forming
the basis of the soap; and that the presence of this "free alkali," although useful
aad beneficial for scouring and laundry purposes, is objectionable when the soap is
required for toilet purposes, inasmuch as it causes the soap to act injuriously on the
skin, causing roughness redness chopping and excoriation, more especially in the
case of infants and others naturally possessing tender skins.
I have found that these objectionable defects due to the presence of the fixed
alkalies potash or soda or of both jointly in the "free" state in soap may be greatly
diminished and in many cases wholly obviated by intermixing with the soap a
suitable quantity of a neutral salt of ammonia formed by the combination of
ammonia with a sufficiently strong acid and by preference with sulphuric or
hydrochloric acid; the proportion requisite being for every 31 parts of anhydrous
soda or for every 47 parts of anhydrous potash, 66 parts of sulphate of ammonia
or 53 parts of chloride of ammonium, or such a quantity of any other neutral salt
of ammonia as will contain 17 parts of ammonia, as is well understood by chemists.
The addition of a small excess of ammoniacal salt to the soap exerts no injurious
influence on the result; but if less than the proportion of ammoniacal salt just
stated be added the whole of the alkalinity due to the free fixed alkalies in the
soap will not be removed but only a part of it in proportion to the quantity of
ammoniacal salt added.

page_text: "
In order to effect the intermixture of the ammoniacal salt with the soap to be
treated by this improved process I proceed as follows:-In the case of such soaps
as are manufactured by the process of " boiling fatty and oily matters with
alkaline leys and finally separating the soap thus formed by addition of common
sult or brine, I add to the nearly fluid soap thus sepurated and purified by standing
or by any of the ordinary processes in use for that purpose the requisite quantity
of ammoniacal salt either in the state of fine powder or dissolved in as small a
quantity of hot water as possible; and then by "crutching "or other convenient
node of agitation intermix the whole thoroughly together; after which the mixture
is run into the moulds or frames to cool and solidify as usual. During this
operation the ammoniacal salt used and the free 6xed alkali in the soap react upon
one another in such a fashion as to convert the free fixed alkali into a neutral salt,
for example into sulphate of soda if soda be the alkali in the soap and if sulphate
of ammonia be the ammoniacal salt added, and similarly in other cases; simul-
taneously a quantity of ammonia is liberated more or less mixed with carbonate of
ammonia according as the free alkali in the soup originally employed was nearly
all in the caustic state or was more or less in the condition of carbonate. A
considerable amount of the ammonia or carbonate of ammonia thus liberated escapes
during the stirring and intermixing; the rest remains for the time being in the
soap, but for the most part evaporates during the subsequent operations of cutting
up the cool musses of soap, and shaping drying and stamping the tablets or bars
ultimately sent into the market: the minute quantity of ammonia or carbonate of
ammonia that is finally retained by the finished soup acts fur less injuriously on
tender skins than an equivalent amount of either potash or soda, so that for all
practical purposes the whole of the free alkali in the original soap is neutralised
by the treatment provided that the duo proportion of ammoniacal salt is used.
In the case of soap prepared by remelting whether consisting of one kind only
or of more than one variety blended together by melting the ammoniacal salt may
be added in fine powder or dissolved in as little water as possible to the soap either
previously to commencing to melt it by the proper application of heat, or whilst
the melting operation is going on, or when the melting is completed; in all cases
incorporating by agitation so as to produce thorough intermixture before finally
running the melted soap into the moulds or frames in which it is allowed to cool as
usual.
In the case of soaps prepared by so called "cold"
lyes and fatty matters are incorporated together at a comparatively low temperature
processes in which alkaline
and without actually boiling and separating the soap formed by means of brine or
salt, I add the ammoniacal salt to the mass at as late a period as possible when the
saponifying action of the alkali on the fatty matter is practically completed, mixing
the whole thoroughly together and then allowing the mass to stand for the purpose
of solidifying as usual.
In the case of "milled" soaps, that is to say soaps prepared at the ordinary
temperature or but little above it by grinding in a soap mill the soap forming the
basis of the composition together with colouring matters perfumes &, I add to the
soap cut into slices or shavings as usual the requisite quantity of ammoniacal salt
either in fine powder or dissolved in as small a quantity of water as possible before
commencing to grind, and then grind the mass together passing it back and forth
through the mill as many times as may be judged necessary to cause the
spontaneous evaporation and escape of any desired proportion of the ammonia or
carbonate of ammonia formed by the action of the unmoniacal salt on the free
alkali contained in the soap; after which I add the coloring matters and perfumes
and proceed as usual to incorporate them with the mass.
when the soap contains but little free alkali, the incorporation of the colouring
In some cases, especially
matters and perfumes may be effected simultaneously with that of the ammoniacal
Balt.
In all cases the end result of this improved process for preparing soaps moro
especially toilet soaps is that if the due proportion of ammoniacal sults be used the

page_text: free fixed alkali contained in the soap is destroyed as such, being converted into a
neutral salt; whilst of the equivalent quantity of ammonia generated during this
neutralisation of fixed alkali the great majority escapes either at once or during the
subsequent operations gone through in preparing the soap for sale, whilst the small
residual quantity which does not thus escape is practically devoid of injurious
action on tender skins; so that for all practical purposes a complete removal of free
alkali from the soap is effected.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
Improving and ameliorating soap containing fixed alkali in the "free" condition
by the addition to the soap of a quantity of sulphate of ammonia or chloride of
monium or other suitable salt of ammonia formed by the combination of
ammonia with an acid sufficiently strong to form neutral salts with fixed alkalies
so as to render the soap better fitted for toilet purposes by converting the free
fixed alkali present in it into a neutral salt substantially as hereinbefore described.
Dated this 19th day of January 188
CHARLES ROMLEY ALDER WRIGHT.
Carpmael & Co.,
Agents for the Applicant.