Pyrocatechine

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KennyE
Posts: 98
Joined: Thu May 23, 2013 6:49 am
Location: Waterford, Michigan USA

Pyrocatechine

Postby KennyE » Tue Aug 06, 2013 1:40 pm

Discovered in 1839 by H. Reinsch; Pyrocatechine saw little use in photography because it could not be made chemically pure, plus the cost of it was high.

But by 1898, all that was about to change. Dr Ludwig Ellon & Co. Chemical Works of Charlottenburg, Germany, had discovered how to make it chemically pure and cheap. With the assistance of Professors H. W. Vogel, Professor J.M. Eder, and Professor P. Banneke of the Royal Technical High School, also in Charlottenburg, Germany. They re-introduce the old formulas of Pyrocatechine.

They also got some help from Messrs Luimere, who replace the carbonate alkali, with T.S.P..

Professor H.W. Vogel Formula
Chemical Amount 750 ml
Sodium sulfite (dessic) 25.0 g
Sodium Carbonate (dessic) 50.0 g
Pyrocatechine 2g
Cold water to make 1000 ml

When used with paper dilute 1:1

Professor J.M. Eder Formula
Solution A
Chemical Amount Units
Water (125°F/52°C) 500 ml
Sodium sulfite (dessic) 40.0 g
Pyrocatechine 10g
Solution B
Chemical Amount Units
Water (125°F/52°C) 500 ml
Potassium Carbonate 40.0 g

1 part of A to 2 parts of B, with 2 parts water


Quick Working Formula
Solution A
Chemical Amount Units
Water (125°F/52°C) 250 ml
Sodium sulfite (dessic) 25.0 g
Pyrocatechine 5g
Solution B
Chemical Amount Units
Water (125°F/52°C) 2500 ml
T.S.P 47.0 g
Sodium Hydroxide 5.0 g

1 part of A to 1 parts of B, with 1 part water

The article is from Photogr. Mittheilungen 1898

Luimere will go on to work with Para-phenylenediamine in 1904, which will be followed years later by Johnson and Sons in 1934. Johnson and Sons work and invention "Meritol, will lead DuPont on a search that will cover the years 1939 to 1946,to create a new developer. DuPont abandon their research, when they turned their attentions towards X-Ray color photography.


Photography Formulary sells a very good Pyrocatechine formula. "Windisch Pyrocatechin Film Developer"

Thank You

KennyE


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