IMPROVEMENTS IN THE MANUFACTURE OF COLORING MATTERS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 24th November 1883. Communicated
to him from abroad by Messieurs Léo Vignon et C, of Lyons, France.
21
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN THE MANUFACTURE OF
COLORING MATTERS " [A communication to him from abroad by Messieurs Léo
Vignon et Cie, of Lyons, France.]
This invention relates to a method or process of manufacturing coloring matters,
such as yellow, orange, red, and violet, from a-naphthol.
The said invention consists chiefly in causing the diazoic compounds obtained
with the amines or their sulpho-conjugated derivatives (derivés sulfo-conjugués)
to react upon the various sulpho-conjugated derivatives (derivés sulfo-conjugués)
of a-naphthol.
Some of these coloring matters, which vary in shade from yellow and orange to
red and violet, have the characteristic property of becoming slowly fixed, upon
animal fibres, when employed in acid and boiling dyeing baths; thus permitting
uniform shades to be obtained upon wool and silk as easily as with tinctorial
matters of vegetable origin.
Amongst the diazoic derivatives which may be used are the following, that is.
to say Aniline, orthotoluidine, paratoluidine, the various isomeric xylidines,
cumidine, the homologues of these substances, amido-azo-benzole (amidoazo benzol)
and its homologues, naphthylamine and its homologues, and generally all aromatic
amines containing the group NH2, as well as the sulpho-conjugated derivatives
(derivés sulfo-conjugués) of these different bases.
These diazoic derivatives are prepared in a manner known to chemists, by,
causing half a molecule of nitrite of sodium to react, at a temperature of about 0°
Centigrade, upon one molecule of amine- or of its sulpho-conjugated derivative
(derivé sulfo-conjugué) in solution or in suspension in ten times its weight of
water, to which are added two or three molecules of hydrochloric or sulphuric
acid. The proportions of water and acid may, however, be varied; it is sufficient
that the relative proportions of the re-agents should satisfy the following.
equation:-
2 ((R) HN H³) + Na' N' O' + 3H Cl = 2 ((R) N³) + 2 Na Cl + 4H2O + HCI.*
And that the proportion of water and ice employed should permit of constituting
a physical medium sufficiently liquid and sufficiently cold.
The diazoic derivative thus formed is added to an aqueous solution containing an
excess of sulpho a-naphtholate of sodium (sulpho a-naphtolate de sodium) and
enough ammonia or carbonate of soda to cause, when the mixture is effected, the
reaction of the liquor to be, finally, slightly alkaline or neutral.

page_text: According to the different sulpho-conjugated derivatives (derivés sulfo-conjugués)
of a-napthol employed, coloring matters of different shades and properties will
be obtained.
The number of sulpho-derivatives of a-naphthol foreseen by theory is
considerable, but only a very small number of the same are scientifically known.
I will now proceed to enumerate the different means employed according to this
invention for the preparation of different sulpho a-naphthols.
First. A mixture of one part of a-naphthol and three parts of monohydrated
sulphuric acid (acide sulfurique monohydrate) is maintained at a temperature not
exceeding 25° Centigrade, until the mixture is rendered soluble in water.
Second. The said mixture is heated for three hours at 80° Centigrade.
Third. The said mixture is maintained for three hours at a temperature of 120°
Centigrade.
Fourth. Fuming sulphuric acid containing 20% of anhydride is substituted
for the monohydrated acid used in the preceding mixture.
Fifth. The diazoic derivative of the sulpho-conjugate (sulfo-conjugué) of the a-
naphthylamine (acide naphtionique) is decomposed with the aid of heat according
to the following reaction:-
C¹º H* N² So³ + H2O + Ag = C¹º H³ O So³ + N² + Ag.
Such a decomposition is easily effected by introducing gradually, in small
quantities at a time, into the boiling water, whether acid, neutral or alkaline, the
diazoic derivative of the naphthionic acid (acide naphtionique). The sulpho a-
naphthols will differ according to the conditions under which the diazo-derivative
of the naphthionic acid (acide naphtionique) is formed (aqueous solution or
alcoholic solution); in like manner identical naphthionic acids (acides naphtioniques
identiques) will produce sulpho a-naphthols differing from one another according
to the manner in which the conversion of the sulpho-azo-derivative (sulfoazoderivé)
into a corresponding sulpho-phenol has been carried out (ebullition in alkaline,
neutral or acid solution),
For instance; in
100 parts of water are dissolved
30 parts of commercial hydrochloric acid and
added:-
7.42 parts of pure nitrite of sodium dissolved in water, the mixture being
maintained at a temperature of between 2° and 3° Centigrade. The diazo-benzole
(diazobenzol) is formed instantaneously.
The sulpho a-naphthol is, on the other band, prepared according to one of the
above mentioned processes by converting the crude sulpho-naphthol obtained into
a salt of lime and then into a salt of soda. In 100 parts of water is dissolved a
quantity of sulpho-a-naphtholate of sodium (sulfo a naphtolate de sodium)
corresponding to
30 parts of a-naphthol, and to the liquor is added a slight excess of carbonate
of soda or of ammonia; it is then cooled down to about 0° Centigrade, and the
diazo-benzole (diazobenzol) is poured into this solution, care being taken to
strongly agitate the mass whilst the mixture is being effected; the liquor must be
neutral or alkaline. The coloring matter is formed instantaneously and is collected
according to circumstances either by evaporation or by precipitation by means of
sea-salt.