Manufacture of Colouring Matters having Acid Action.
Year: 1897

page_text: Date of Application, 14th July, 1897
Complete Specification Left. 2nd Apr. 1898-Accepted. 28th May. 1898
PROVISIONAL SPECIFICATION.
Manufacture of Colouring Matters having Acid Action.
I, MAURICE PRUD'HOMME, of 78, Avenue de la Grande Armée, Paris, France,
Chemist, do hereby declare the nature of this invention to be as follows:-
For some years past formic aldehyde or its polymers have been employed under
various circumstances and their action on amide colouring matters and primary
aromatic amines have formed the subject matter of several patents or special
publications. Tollens, in Berichte 17, p. 657 and Tollens & Wellington in Berichte
18, p. 3309 bave obtained and described anhydroformaniline, prepared by the action of
formic aldehyde upon aniline.
Pratesi has, under somewhat different circumstances, obtained, with the same
substances, methylene diphenyldiamine, and Geigy's German Patent 75854 of 27th
March 1891 describes the transformation of Tollens' substance, anhydroformaniline,
into monomethylaniline by the action of reducing agents on this substance.
Goldschmidt & Poltzer in Berichte 24 p. 1000 have effected from another point of
view, the reaction of an aqueous solution of formic aldehyde upon the product of the
reaction of orthoamidoazotoluene and B-naphthylamine, and under the same
conditions Noeltin and Herzberg (Revue générale des matières colorantes, Vol. 1
p. 29) have replaced formaldehyde by benzaldehyde, the orthoamidoazotoluene and
B-naphthylamine being replaced by chrysoidines.
I have now discovered that under peculiar conditions of reaction, formaldehyde in
aqueous solution, associated with bi-sulphite of soda has a pronounced and special
action upon the basic colouring matters, simple amides, in transforming them into
colouring matters of different tints, while at the same time the initial basic function
became a very pronounced acid function.
A dilute aqueous solution of fuchsine, hydrochloride of rosaniline, is treated by
means of dilute sulphuric acid and a dilute solution of a mixture of formic aldehyde
and sodium bisulphite; the liquor is left standing some days at atmospheric
temperature.
The proportions of the reagents are variable according to the results to be
obtained and the desired ultimate tint of the new colouring matters. Thus for
example, one can operate with one kilo. of fuchsine dissolved in 100 litres of water
15 kilos. of sulphuric acid of 10 per cent., 4 to 7 kilos. of commercial formaldehyde of
40 per cent. and 10 to 20 kilos. of sodium bisulphite of 30° Bé.; after standing for 3 or
4 days the red basic colouring matter will have entirely disappeared, and have been
replaced by a decided violet liquor.
The new colouring matter obtained is violet; solutions are no longer precipitated
by alkalies, such as carbonate of soda, but they are decolourised. The decolourised
alkaline liquors resume their former intense colour on the addition of an acid.
The solutions do not die cotton mordanted with tannin, and only indifferently wool
in a neutral bath, but they die wool very effectually in an acid bath. This colouring
[Panice 11

page_text: disintegrated or powdered cork which may or may not be mixed with silicious sinter
and oil varnish, and are in this case especially suitable as wall and floor coverings.
Dated this 13th day of July 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in and relating to the Manufacture of Artificial
Blocks or Plates for Building and other purposes.
I, HENRY HARRIS LAKE, of the Firm of Hazeltine, Lake & Co., Patent Agents,
45, Southampton Buildings, 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 described and ascertained in and by the following statement:-
This invention relates to an improved method of manufacturing a porous insulating
or separating and covering substance for building and other purposes, its characteristic
feature being that well burnt dolomite is slaked in a highly diluted solution of
hydrochloric acid and converted into a pulp containing chloride of magnesium, to
which moistened cork, peat moss or other light insulating or separating material
is added.
After the product obtained has been thoroughly mixed, so that each constituent
particle of the insulating material is encased, as it were, by the pulp of chloride of
magnesium, the product is ready to be formed into plates or blocks and to be
subsequently dried. Although the drying by the action of the atmospheric air is
sufficient, it is preferable to subject the product to an artificial additional drying at a
temperature of from 35 to 50 degrees Centigrade, to ensure that the enclosed particles
of the insulating material, for example cork, may give off their contents of water
through the thin layer of lime. It is not until the inner insulating material has lost
its moisture entirely-which when drying by air alone is employed, may last for
months that the layer of lime hardens by receiving a glazed appearance and so
thoroughly surround the completely dried insulating material on all sides that
the latter is well protected against moisture and swelling and likewise most
efficiently protected from danger of fire.
In order to further increase the porosity and hardness of the material it is suitable
that trass, pumice, kieselguhr or the like be added to the lime pulp containing
the chloride of magnesium. The further procedure then takes place in the manner
described that is to say, the product obtained after the cork, peat moss or the like
having been properly mixed with the lime pulp, is formed directly into blocks or
plates. In addition, the lime pulp may be utilized as a coating for the blocks or
plates produced according to the first described manner after the said plates or blocks
have become sufficiently hard.
Blocks or plates of this kind may in addition be provided with a coating of highly
disintegrated or powdered cork which may or may not be mixed with kieselguhr and
oil varnish, and are in this case especially suitable as wall and floor coverings.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondents, I declare that what I claim is :-
1. The herein described process which consists in reacting upon calcined
dolomite with a solution of hydrochloric acid, mixing with the pulp or magma so
obtained an organic porous or fibrous substance, forming from the mixture, blocks,
7

page_text: slabs and the like and expelling the moisture therefrom, for the purpose set
forth.
2. An article of manufacture consisting of an organic porous or fibrous material
and a binding or cementing substance consisting of calcined dolomite reacted upon
with a solution of hydrochloric acid, for the purpose set forth.
A 1 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.

page_text: complete according to the quantities of formaldehyde used, that is to say, in certain
cases, if the quantity of formaldehyde was insufficient, there may be obtained
mixtures of colouring matters having acid functions and untransformed colouring
matters having basic functions.
The colouring matters obtained by this method have therefore the characteristics
of change of tint, acid action, and great affinity for wool in acid bath..
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described process for transforming by means of formaldehyde and
sodium bisulphite, basic colouring matters of certain tints into acid colouring matter
of different tints, the colouring matters so treated including fuchsine, safranine,
amido-indulines, thionine or Lauth violet, curhodines, phosphines or acridines, the
Hofmann violets or those derived from paramidobenzaldehyde, the greens derived
from metamidobenzaldehyde, phthaleine containing a primary or secondary
amido-group, the azo-colours and generally all the colouring matters having in their
constitution one or more primary or even secondary amido-groups.
2. The colouring matters obtained as above set forth.
Dated 11 and day of Al 1000
ABEL & IMRAY,
Agents for the Applicant.