This is topic Mystery Eastman Kodak product - Thorium Chloranilate in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by John Schulien (Member # 215) on 10-04-2002, 12:57 PM:
 
I'm looking at a small, clean, empty bottle labelled:

EASTMAN

Thorium Chloranilate

(O:C6Cl2O2:O)2Th.3H2O ... MW 700.01
For Chemical Purposes. Not For Drug Use
Eastman Kodak Co. Rochester, NY.

Rarely do I run across something that produces zero google hits,
but this is an example. Since Google struck out, I'm calling out the heavy guns and presenting the question to film-tech's far more powerful resident search engine :

What the devil was this stuff used for?

Barium Chloranilate is used to detect and quantify sulphate contamination, so I suspect that it's something along those lines.


 


Posted by Sam Hunter (Member # 1119) on 10-07-2002, 01:18 PM:
 
Try this website. http://www.chembuyersguide.com/index.htm
 
Posted by John Pytlak (Member # 331) on 10-07-2002, 01:52 PM:
 
Gotta get the name right first:

THORIUM CHLOROANILATE

The EASTMAN Chemical Company manufactures hundreds of Laboratory Chemicals, mostly used for university research, medicine, and by other industries:
http://www.eastman.com/Product_Information/Chemicals.asp

They have been a separate company from the Eastman Kodak Company since 1994:
http://www.eastman.com/About_Eastman/About_Eastman_Intro.asp

I suspect this may have been used as a radioactive tracer in research?
Where did you find the bottle? Have you been decontaminated yet?


------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion


 


Posted by Sam Hunter (Member # 1119) on 10-07-2002, 10:20 PM:
 
AHHHHHHHHHHHH!!
John you’ve contaminated me!!!
AHHHHHHHHHHH!!

------------------
Samual Hunter Sr.


KC5ZSL


 


Posted by Leo Enticknap (Member # 534) on 10-08-2002, 04:49 AM:
 
As if that wasn't bad enough, uranium sulphate was routinely used as a tinting dye for release prints in silent film days. Archives and labs which regularly handle these elements tend to keep a Geiger-Müller meter on site.


 


Posted by Steve Kraus (Member # 476) on 10-08-2002, 07:29 AM:
 
Thorium compounds are sometimes added to optical glass to change its characteristics. That creates a small radiation hazard. Consider that the next time you put binoculars up to your eyes to ogle the neighbor girl.
 
Posted by John Schulien (Member # 215) on 10-08-2002, 06:17 PM:
 
John --

I think the name is right. It's spelled that way on the bottle -- "chloranilate" -- and google returns a number of hits on this spelling, and much small number of hits on "chloroanilate."

I've had the bottle checked, and it isn't radioactive. I've washed my hands carefully each time I've touched it anyway, just in case.

Leo -- what color would Uranium Sulphate dye the film? Seems like a good thing to be aware of!

I have a book on dye transfer photography, where the author discusses soaking the receiver film in a dilute solution of Thorium Nitrate -- apparently Thorium is a superior dye mordant. This was done for still photography, but it makes me wonder if Technicolor ever used Thorium as a mordant. Any archivists/collectors want to check their collection with a geiger counter?


 


Posted by Steve Kraus (Member # 476) on 10-08-2002, 09:36 PM:
 
My old IB printing information makes no mention of thorium nitrate. After the blank is processed and fixed (for the silver soundtrack and in the early days, a faint B&W "key" image") it was hardened in a chrome alum bath.
 
Posted by Leo Enticknap (Member # 534) on 10-09-2002, 02:55 AM:
 
John S - it was an amber tint. The radiation in any surviving element now will probably have decayed so much that you're in far more danger breathing the air in an average urban street. But in one lab tour I had we had a demonstration with a G-M meter and it still got a slight reaction.
 
Posted by John Schulien (Member # 215) on 10-09-2002, 01:43 PM:
 
Here's the information that I found:
http://www.dyetransfer.org/

On this page, you'll find a link to a PDF file describing James Browning's work in producing dye transfer prints from scratch. This PDF is absolutely fascinating. His work is very impressive. He manufactures matrix film from scratch -- he starts from uncoated polyester film mixes and coats the emulsions himself, exposes the matrices using a laser scanner, and hand-transfers the dyes. The PDF contains all of the chemical formulas and mixing directions for every step of the dye transfer process. This is highly recommended reading for anyone curious about the chemistry and process.

On page 8, we find:

quote:

If you don ’t have Kodak Dye Transfer paper,you will need to prepare your own paper.I have used Ilford MG FB F paper successfully.Fix and wash the paper completely. Mordant by soaking for 10 minutes in a
1% solution of Thorium Nitrate.You can try the M-1 mordant if you don't want to work with Thorium.

Kodak M-1 Mordanting Solution
Part A
Aluminum Sulfate 200 g
Water to 1 L

Part B
Sodium Carbonate 80 g
Water to 1 L

Mix one part B to one part A.Add B to A. ...


... which is where I made the connection between thorium compounds and film manufacture.
 


Posted by Steve Kraus (Member # 476) on 10-09-2002, 09:25 PM:
 
Fascinating. Now if we can only get this guy interested in motion picture work instead of just still prints.
 
Posted by David Koegel (Member # 25) on 10-11-2002, 09:56 AM:
 
Thorium is indeed radioactive, but is a very low emitter of radiation. Its half-life [the time it takes for 1/2 of a given amount of thorium to radioactively "decompose"] is very long (77,000 years), hence it's a very low radiation hazard. If you want related information written from the perspective of a radioactive cleanup company, see thorium

I believe it is thorium nitrate that is used in preparation of the "Welsbach mantle", used for portable gas lights [e.g., Coleman lanterns]. The mantles start off as a cloth impregnated with this chemical, with the cloth burning off when first used. The resulting mantles consist of thorium oxide (ThO2) with about 1% cerium oxide and other ingredients. They glow with a dazzling light when heated in a gas flame, as you may have noticed

From the bin of “you can never know too much about something,” thorium oxide has a melting point of 3300°C, the highest of all oxides. Only a few elements, such as tungsten, and a few compounds, such as tantalum carbide, have higher melting points. Even more fascinating information can be found at thorium facts

end of chemistry/physics lesson
 






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