Process for Obtaining New Dyestuffs of the Phthaleïne Series.
Year: 1897

page_text: Date of Application, 17th May, 1897-Accepted, 19th June, 1897
COMPLETE SPECIFICATION.
Process for Obtaining New Dyestuffs of the Phthaleïne Series.
I, HAROLD IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by The Basle Chemical Works
Bindschedler, of Basle, Switzerland, Manufacturers) and in what manner the same is
to be performed to be particularly described and ascertained in and by the following
statement :-
My foreign correspondents have found that the dialkyl amido oxybenzoyl benzoic
acids can easily be condensed with para-amido-ortho cresol in sulphuric acid solution
to form valuable dyestuffs which can be etherized and then form salts soluble in water.
These dye tannin mordanted cotton of pure yellow red tints.
EXAMPLE.
31 kilos. of diethylamido oxybenzoyl-benzoic acid together with 15 kilos. of paramido
ortho-cresol (CH3: OH: NH,= 1:2:4) are mixed with 180 kilos. of monohydrated
sulphuric acid and 40 kilos. of water, and heated to 140°-160° C. until a sample
dissolves in warm water. The mixture is then poured into about 1000 litres of water
and heated for a longer time. Cooling, filtration and washing with water follow.
The residue is suspended in 100 litres of alcohol and 100 litres of ammonia of about
10 per cent. strength are added so as to produce an ammoniacal solution.
The mixture is then heated and filtered and 100 litres of hydrochloric acid of about
30 per cent. are added to the hot filtrate, so that an excess of acid is present.
After thorough heating the mixture is allowed to cool. Beautiful crystals of a
green lustre then separate. These are collected and dried. 30 kilos. of them are
heated in a reflux apparatus with 100 litres of alcohol and 45 kilos. of monohydrated
sulphuric acid for about 8 hours. The mixture is then poured into about 1000 litres
of water and the dyestuff is salted out with potassium bisulphate, dissolved, filtered
and still 100 kilos. of potassium bisulphate are added; the liquor is left to cool and
crystallise.
The dyestuff thus obtained dyes tannin-mordanted cotton a fiery yellow-red.
The dyestuff forms a yellow red powder which dissolves in water and alcohol with a
yellow red colour. In strong sulphuric acid it dissolves with a yellow colour. The
dyestuff base is soluble in alcohol and ether.
The ammoniacal alcoholic solutions have a beautiful yellowish green fluorescence.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I
claim is :-
1. A process for obtaining new dyestuffs by condensation of dialkylamido oxy
benzoyl benzoic acids with para-amido-ortho cresol in the manner described.
2. The conversion of the dyestuffs formed according to Claim 1 into new
derivatives by heating them with an alcohol and an acid in the manner described.
3. As new industrial products, the dyestuffs obtained according to Claims 1 and 2.
Dated this 17th day of May 1897.
ABEL & IMRAY,
Agents for the Applicant.