Anyone know anything about the chemistry of 1970s polaroid color film opacifiers?

Hi all,

I've just recently watched a video about how one thing impossible project wasn't able to replicate was the opacifier coating on their film that keeps the image protected from light while developing and then fades to clear.

I've read a lot here but never made an account so I've seen time and time again that the user Photo Engineer has a lot of detailed knowledge on film chemistry so I was wondering if maybe they could chime in or of course anyone else that might know something about this.

It just seems odd that with modern chemical suppliers and an even better knowledge of chemistry in general than 50 years ago that this couldn't be replicated.

Also if anyone knows of any patents or other literature I could read about this, I'd love that!

Thanks all!

Hollon said:

an even better knowledge of chemistry in general than 50 years ago

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I kinda wonder if that's actually true. A lot of knowledge has been protected by industrial privacy and lost when those industries stopped needing it.

Photo Engineer passed away a few years ago.

Hollon said:

It just seems odd that with modern chemical suppliers and an even better knowledge of chemistry in general than 50 years ago that this couldn't be replicated.

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It's essentially a chemical dark slide that forms rapidly in the development stage and is clarified in the fixing step. The level of opacity needed is significant.

Environmental safety issues and available research budget are the two most likely reasons for Impossible not managing to replicate it. There are Kodak patents covering how they (and by extension Fuji, as Instax is based off Kodak instant tech) did it - I want to say it was pH controlled, but am not certain on this. From recall, there are some components that will have had to be replaced to comply with legislative changes - and Kodak was doing its best to avoid how Polaroid hade done things, so the cross compatibility of the components is probably low.

Hollon said:

Hi all,

I've just recently watched a video about how one thing impossible project wasn't able to replicate was the opacifier coating on their film that keeps the image protected from light while developing and then fades to clear.

Click to expand...

Welcome to teh forum. The way to interpret "wasn't able to replicate" could be "wasn't able to replicate with the available R&D resources and capital investment funding".

Not sure what information you are really after, the Impossible Project efforts or the original Polaroid efforts. There are plenty of very detailed patents available under the inventor name "Edwin Land". If you are refering to SX-70-type film where the negative is not separated from the positive, perhaps this one is close to where you want to start your research:

My understanding is that one of the biggest challenges that modern Polaroid faces is that they aren't big enough to do their own chemical synthesis or have synthesis done the way original Polaroid did. A lot of chemicals involved in instant film are fairly unusual and if you're forced to work "off the shelf", some sacrifices have to be made

thinkbrown said:

My understanding is that one of the biggest challenges that modern Polaroid faces is that they aren't big enough to do their own chemical synthesis or have synthesis done the way original Polaroid did. A lot of chemicals involved in instant film are fairly unusual and if you're forced to work "off the shelf", some sacrifices have to be made

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Indeeed. This is an economic reality for niche products. Small production quantities and limited interest has negative impact on ability to fund production of a complex product. And that extends to more than just the chemistry...

BrianShaw said:

Indeeed. This is an economic reality for niche products. Small production quantities and limited interest has negative impact on ability to fund production of a complex product. And that extends to more than just the chemistry...

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Given Polaroid has continued to grow their market and is building out a new factory I'm cautiously optimistic we could see some further improvements as they scale.

thinkbrown said:

Given Polaroid has continued to grow their market and is building out a new factory I'm cautiously optimistic we could see some further improvements as they scale.

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The key indicator will be if they invest in/ expand on-site kilo lab synchem capacity.