Production of Yellow Dye or Colouring Matter.
Year: 1890

page_text: Date of Application, 1st Feb., 1890
Complete Specification Left. 13th Oct., 1890-Accepted, 15th Nov., 1890
PROVISIONAL SPECIFICATION.
Production of Yellow Dye or Colouring Matter.
I, THOMAS RICHArd Shillito of 89 Chancery Lane, in the County of Middlesex,
Engineer, do hereby declare the nature of this invention, a communication to me
from abroad by John Rudolph Geigy & Co., of Basle, Switzerland, Colour Manu-
facturers, to be as follows:-
This invention consists in the production of colouring matter by treating the diazo
compound of polychromin with ammonia.
The diazo compound of polychromin (sulpho-acid of thioparatoluidine, also called
primuline) is but slowly decomposed when boiled in an acidulated solution and the
resulting product is of no practical value but it undergoes a quick change when
submitted to the action of alkalies.
When a watery solution is mixed with ammonia and left to stand it acquires a
brown colour whilst nitrogen is formed. By boiling the reaction is completed and
the dye stuff of this invention produced. It dyes cotton without the aid of a
mordant.
As an example of the manner of carrying out the invention, 50 kilogrammes of
polychromin dissolved in 1000 litres of water and mixed with 30 kilogrammes of
muriatic acid of 20.5° B., are diazotised by addition of 7 kilogrammes of nitrite
of sodium, then 30 kilogrammes of ammonia, of 25° B., are added.
After the lapse
of about twelve hours the solution is boiled and when it is observed that scumming
is finished the colouring matter is precipitated by the addition of salt.
When dried the substance is in the form of a brown powder easily soluble in water
distinguished from polychromin by the property of dyeing cotton gold yellow which
acquires an orange red colour by caustic alkalies.
Dated this 1st day of February 1890.
THOMAS RICHARD SHILLITO,
89, Chancery Lane, London, W.C.
COMPLETE SPECIFICATION.
Production of Yellow Dye or Colouring Matter.
I, THOMAS RICHARD SHILLITO, of 89 Chancery Lane, in the County of Middlesex,
Engineer, do hereby declare the nature of this invention, a communication to me
from abroad by John Rudolph Geigy & Co. of Basle, Switzerland, Colour Manu-
facturers, and in what manner the same is to he performed to be particularly
described in and by the following statement:-
This invention relates to the production of colouring matter by treating the
diazo compound of polychromine or of dehydrothio-p-toluidine sulpho acid with
ammonia.
The diazo-compound of polychromine (sulpho-acid of thioparatoluidine, also called
primuline) or of dehydrothio-p-toluidine-sulpho-acid, is but slowly decomposed when
boiled in an acidulated solution, and the resulting product is of no practical value,
but it undergoes a quick change when submitted to the action of alkalies.
When a watery solution is mixed with ammonia and left to stand, it acquires a
brown colour whilst nitrogen is formed. By boiling, the reaction is completed and
the dye stuff of this invention produced. It dyes cotton without the aid of a
mordant.
As an example of the manner of carrying out the invention 50 kilogrammes of
polychromine dissolved in 1000 litres of water and mixed with 30 kilogrammes o
muriatic acid of 205 B. are diazotised by the addition of 7 kilogrammes of nitrite

page_text: of sodium, then 30 kilogrammes of ammonia of 25 B. are added. After the lapse of
about twelve hours the solution is boiled and when it is observed that scumming has
finished, the colouring matter is precipitated by the addition of salt.
When dried, the substance is in the form of a brown powder easily soluble in water,
distinguished from polychromine by the property of dyeing cotton gold yellow which
acquires an orange red colour by caustic alkalies.
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:
The production of yellow dye or colouring matter by treating the diazo compound
of polychromine or of dehydrothio-p-toluidine sulpho-acid with ammonia.
Dated this 13th day of October 1890.
T. R. SHILLITO.