Manufacture of Colouring Matters of the Group of the Phthaleines.
Year: 1895

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c., Act, 1883), as allowed by
the decision of the Comptroller General of the 12th day of January 1899.
Date of Application, 8th Mar., 1895-Accepted, 13th Apr., 1895
COMPLETE SPECIFICATION (AMENDED).
Manufacture of Colouring Matters of the Group of the Phthaleines.
Communicated from abroad by BASLE CHEMICAL WORKS, Bindschedler, of Basle,
Switzerland, Manufacturers.
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 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 by the action of 1 molecule of a
dialkylised meta-amidophenol on 1 molecule phthalic anhydride new products of
condensation are obtained.
These new products can serve as intermediate products in the manufacture of
colouring matters, 1 molecule of these new intermediate products is converted into
colouring matters by condensing it with 1 molecule of a meta substituted phenol.
These new intermediate products are obtained either by heating for some time
phthalic anhydride with one of the dialkylised meta-amidophenols in suitable
solvents, or by melting the two components under such conditions that the forma-
tion of rhodamines does not take place.
The new intermediate products are soluble in dilute alkaline carbonates. Acetic
acid precipitates them from these solutions in the form of a colourless powder.
These new intermediate products can be transformed into colouring matters by
combining them with diazo derivatives.
On heating their alcoholic solutions charged with hydrochloric acid the new
intermediate products are transformed into etherine bodies insoluble in carbonate
of soda.
Their readiness of reaction with the meta substituted phenols is quite remark-
able.
Equivalent quantities of intermediate products and of a meta-amidophenol
dissolved in concentrated sulphuric acid when moderately heated during several
hours, yield the corresponding phthalic colouring matter. On boiling with
alcohol and hydrochloric acid these colouring matters are converted into new
colouring matters presenting different qualities in respect of tints and dyeing
power.

page_text: EXAMPLE 1.
15 kilos. phthalic andydride acid and 17 kilos. diethyl-meta-amidophenol are
dissolved in 75 kilos. toluene. The solution is filtered when hot and heated during
several hours to boiling point. The new intermediate product separates in form
of crystals which are purified by recrystallisation from alcohol.
10 kilos. of the intermediate product thus obtained are dissolved in about
60 kilos. sulphuric acid (about 96%-98% H2SO4) and 6 kilos. dimethyl-meta-
amidophenol are added.
The solution is heated to 100-120° C. until a test gives a clear solution in
water, then it is poured into 500 litres of water and boiled, then filtered and
precipitated by salt.
The colouring substance is purified by recrystallisation from hot water, acidu-
lated with hydrochloric acid. It presents then green crystals and dyes wool,
cotton and silk a fine red.
The etherified substance dyes a more blue tint.
EXAMPLE II.
30 kilos. dimethyl-meta-amidophenol and 30 kilos phthalic anhydride are
heated to 100° C. until the melted substance ceases to thicken. The product is
then pulverized and dissolved in the necessary quantity of alcohol. The solution
is filtered while hot and has added to it a quantity of water until the warm liquid
becomes slightly turbid. Then the intermediate product separates in crystals,
which can be obtained pure by repeated recrystallisation in dilute alcohol.
20 kilos. of the dimethylated intermediate product thus obtained and 15 kilos.
mono-ethyl-meta-amidophenol are dissolved in a mixture of 200 kilos. sulphuric
acid mono-hydrate and 50 kilos. water. The whole is heated to 150-160° C. and
when a test gives a clear solution in warm water it is poured into about 800 litres
water, the colouring matter is precipitated by salt, filtered and purified by recrys-
tallisation from hot water acidulated by sulphuric acid.
The colouring substance dissolves in concentrated sulphuric acid with a yellow
colour. It is soluble in alcohol and in water, its dilute alcoholic solutions have
a fine greenish yellow fluorescence. It dyes wool, cotton mordanted with tannin
and silk with red tints. Its alkyl-ethers dye tints more blue.
In the same way as the intermediate products soluble in soda, are combined
with meta-amidophenols, can also be combined the corresponding alkyl ethers,
which are not soluble in soda.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is
1. The manufacture of new intermediate products by condensation of phthalic
anhydride and dialkylised meta-amidophenols, such as
dimethyl-meta-amidophenol ·
diethyl-meta-amidophenol
methyl-ethyl-meta-amidophenol.
2. The manufacture of the alkyl ethers of these intermediate products produced
as set forth in the preceding claim by heating their alcoholic solutions with
hydrochloric acid.
3. The manufacture of phthalic colouring matters of unsymmetrical constitu-
tion by condensing the new products referred to in Claims 1 and 2 with meta
substituted phenols, such as:-