The Manufacture and Production of Yellow Colouring-matters from Benzoin.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
The Manufacture and Production of Yellow Colouring-matters
from Benzoin.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by The Badische Anilin & Soda Fabrik of
Ludwigshafen-on-Rhine, in the Empire of Germany) to be as follows:-
My foreign correspondents have discovered that benzoïn and aromatic oxy-
carbonic acids, such as gallic acid, or beta-dioxybenzoic acid, in sulphuric acid
solution condense to yellow colouring matters.
The shades obtained with them upon chrome mordanted wool are characterized
by their excellent fastness against fulling.
The following will serve to further illustrate the nature of the invention but the
invention is not limited to the details. The parts are by weight.
One hundred parts of gallic acid are dissolved in sixteen hundred parts of
sulphuric acid of 66° Bé. and this solution is cooled to between zero and plus five
degrees Centigrade. One hundred and twenty six parts of benzoin are stirred into
this solution and stirring is continued for twenty four hours. The mass is then
poured into eight thousand parts of water and the precipitated colouring matter
is filtered off and washed out.
The colouring matter constitutes a yellow paste similar to alizarine. It is
insoluble in water, but dissolves with difficulty in sodium carbonate with a yellow
brown solution. The caustic soda solution is cherry-red. Sulphuric acid of 66° Bé:
dissolves the colouring matter the solution being yellow and possessing a beautifu!
green fluorescence. This colouring matter is difficultly soluble in benzene ligroine
and the like but is easily soluble in alcohol, glacial acetic acid and nitrobenzene.
It crystallizes from glacial acetic acid in yellow-brown crystalline aggregate.
It yields an acetyl compound crystallizing in yellow needles and melting at two
hundred and thirty seven degrees Centigrade.
The condensation-product of benzoin and symmetric dioxybenzoic acid is
prepared in a similar manner to the foregoing. It differs from the condensation
product obtained with gallic acid by its greener shades. The colouring matter
dissolves in alkalies with a yellow-red colour; the solution in sulphuric acid of
GGO Bé. is rhodamine red and has a brown fluorescence.
Dated this 10th day of June 1897
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: COMPLETE SPECIFICATION.
The Manufacture and Production of Yellow Colouring-matters
from Benzoin.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by The Badische Anilin & Soda Fabrik, of
Ludwigshafen-on-Rhine, in the Empire of Germany) 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 discovered that benzoin and the aromatic oxy-
carbonic acids, gallic acid, or beta-dioxybenzoic acid, in sulphuric acid solution,
condense to yellow colouring matters.
The shades obtained with them upon chrome mordanted wool are characterized
by their excellent fastness against fulling.
The following will serve to further illustrate the nature of the invention and the
manner in which it can be performed but the invention is not limited to the details.
The parts are by weight.
:
One hundred parts of gallic acid are dissolved in sixteen hundred parts of
sulphuric acid of 66° Bé. and this solution is cooled to between zero and plus five
degrees Centigrade. One hundred and twenty six parts of benzoin are stirred into
this solution and stirring is continued for twenty four hours. The mass is then
poured into eight thousand parts of water and the precipitated colouring matter
is filtered off and washed out.
The colouring matter constitutes a yellow paste, similar to. alizarine. It is.
insoluble in water, but dissolves with difficulty in sodium carbonate forming a yellow-
brown colour, the caustic soda solution is cherry red. Sulphuric acid of 66° Bé.
dissolves the colouring matter, the solution being yellow and possessing a beautiful
green fluorescence. This colouring matter is difficultly soluble in benzene, ligroine,
and the like, but readily dissolves in alcohol, glacial acetic acid, and nitro-benzene.
It crystallizes from glacial acetic acid in yellow-brown crystalline aggregates.
It yields an acetyl compound crystallizing in yellow needles, and melting at two
hundred and thirty seven degrees Centigrade.
The condensation-product of benzoin and symmetric dioxy-benzoic acid is
prepared in a similar manner to the foregoing. It differs from the condensation
product obtained with gallic acid in being of greener shades. The colouring
matter dissolves in alkalies forming a yellow-red solution. The solution in
sulphuric acid of 66° Bé. is rhodamine-red and has a brown 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. The manufacture of yellow colouring-matters by condensing benzoin and
gallic acid in sulphuric acid solution, substantially as herein before described.
2. The manufacture of yellow-colouring matters by condensing benzoin and.
beta-dioxy-benzoic acid in sulphuric acid solution, substantially as hereinbefore
described.
3. As new articles of manufacture the yellow dyestuffs which can be obtained.
substantially as hereinbefore described.
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