IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN DERIVATIVES FROM COAL TAR PRODUCTS
Year: 1880

page_text: LETTERS PATENT to Charles Lowe and John Gill, both of Manchester, in
the County of Lancaster, Manufacturing Chemists, for an Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN DERIVATIVES FROM
COAL TAR PRODUCTS."
PROVISIONAL SPECIFICATION left by the said Charles Lowe and John
Gill at the Office of the Commissioners of Patents on the 20th November
1880.
"
CHARLES LOWE and JOHN GILL, both of Manchester, in the County of Lancaster,
Manufacturing, Chemists. 'IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN
DERIVATIVES FROM COAL TAR PRODUCTS."
The object of our Invention is to effect novel and economical improvements in
the manufacture of napthol, resorcin, and their homologues, by the substitution
of sulphurous acid for the hydrochloric or sulphuric acid hitherto employed to
separate them from their alkaline solutions obtained in the ordinary process of
manufacture.
Secondly. The production and utilization of residual or by products having
greater commercial value than the residual or by products obtained by the
application of the well known methods now in use for the separation of the said
napthol, resorcin, or their homologues, from their alkaline solutions.
To carry these objects into effect, and in substitution for the sulphuric or hydro-
chloric acids hitherto used, we cause to pass through, over, or mix with the said
alkaline solutions (of the napthol, resorcin, or their homologues, contained in and
by means of any suitable apparatus) a current of sulphurous acid until sufficient
saturation of the potash, soda, or lime of the said alkaline solutions is effected.
The saturation by sulphurous acid of the base of the said alkaline solutions of the
crude tar acids, napthol, resorcin, or their homologues, we carry either to the point
of neutrality only, or to any further degree of saturation that may be required
in excess of this point in order to form mixed or acid sulphites. After suitable
saturation of their alkaline solutions with sulphurous acid the napthol, resorcin;
or their homologues may be separated in the usual manner, and the watery solution
IP 71

page_text: of the neutral or acid sulphites of potash, soda, or lime, prepared in the manner
above described, we utilize in three different ways:-
Firstly. As a direct source of sulphurous acid for disinfecting, bleaching, or other
purposes by simple admixture with a cheap mineral acid, such as sulphuric or
hydro chloric acids.
Secondly. By abstraction. from it of the excess of water present by any of the
well known processes employed for similar purposes, we convert it into crystallized
or dry neutral or acid sulphites of potash, soda, or lime, suitable for the market.
Thirdly. By admixture of the said crystallized or dry neutral or acid sulphites
of potash, soda, or lime, obtained as above described, and the crude tar acids,
carbolic, cresyllic, or their homologues, with silica or china clays, or sulphates of
lime or iron to form disinfecting powders, which on the addition of a cheap mineral
acid are capable of evolving in the state of gas or vapour both sulphurous and the
tar acids.

page_text: DIECIFICATION in pursuance of the conditions of the Letters ratent nied by
the said Charles Lowe & John Gill in the Great Seal Patent Office on the
19th May 1881.
.
CHARLES LOWE and JOHN GILL, both of Manchester, in the County of Lancaster,
Manufacturing Chemists. "IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN
DERIVATIVES FROM COAL TAR PRODUCTS."
The object of our Invention is to effect novel and economical improvements in
the manufacture of napthol, resorcin, and their homologues, by the substitution
of sulphurous acid for the hydrochloric or sulphuric acid hitherto employed to
separate them from their alkaline solutions obtained in the ordinary process of
manufacture.
Secondly. The production and utilization of residual or by products having
greater commercial value than the residual or by products obtained by the
application of the well known methods now in use for the separation of the said
napthol, resorcin, or their homologues, from their alkaline solutions.
To carry these objects into effect, and in substitution for the sulphuric or hydro-
chloric acids hitherto used, we cause to pass through, over, or mix with the said
alkaline solutions (of the napthol, resorcin, or their homologues, contained in and
by means of any suitable apparatus) a current of sulphurous acid until sufficient
saturation of the potash, soda, or lime of the said alkaline solutions is effected.
The saturation by sulphurous acid of the base of the said alkaline solutions of the
crude tar acids, napthol, resorcin, or their homologues, we carry either to the point
of neutrality only, or to any further degree of saturation that may be required
in excess of this point in order to form mixed or acid sulphites. After suitable
saturation of their alkaline solutions with sulphurous acid, the napthol, resorcin,
or their homologues, may be separated in the usual manner, and the watery solution
of the neutral or acid sulphites of potash, soda, or lime, prepared in the manner
above described, we utilize in three different ways :—
Firstly. As a direct source of sulphurous acid for disinfecting, bleaching, or
other purposes by simple admixture with a cheap mineral acid, such as sulphuric
or hydrochloric acids.
Secondly. By abstraction from it of the excess of water present by any of
the well known processes employed for similar purposes, we convert it into
crystallized or dry neutral or acid sulphites of potash, soda, or lime, suitable for
the market.
Thirdly. By admixture of the said crystallized or dry neutral or acid sulphites
of potash, soda, or lime, obtained as above described, and the crude tar acids,
carbolic, cresyllic, or their homologues, with silica or china clays, or sulphates of
lime or iron to form disinfecting powders, which on the addition of a cheap mineral
acid are capable of evolving in the state of gas or vapour both sulphurous and the
tar acids.
Having stated the nature of our Invention, and described how the same is to be
performed, we declare that we claim,―
1. The use of sulphurous acid, as herein described, for the separation of napthol,
resorcin, or their homologues, from their alkaline solutions obtained in the usual
process of manufacture in substitution for the hydrochloric and sulphuric acids
previously employed for the same purpose.

page_text: 2. The production of acid, alkaline, or neutral sulphites, and the utilization of
the same as herein described.
In witness whereof, I, the said John Gill, for myself and on behalf of the
said Charles Lowe, have hereunto set my hand and seal, this Eighteenth
day of May, One thousand eight hundred and eighty one.
JOHN GILL (LS)