Process C-22

Discussion in 'Color: Film, Paper, and Chemistry' started by htmlguru4242, Oct 17, 2005.

  1. htmlguru4242

    htmlguru4242 Member

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    I've found another old roll of film (Kodacolor , Process C-22)

    I was wondering if anyone knows anyhting about this process, as i know its quite old. The most info. that I've been able to find on it is that it was phased out in the 1970s, and that the films had to be hardened pre-development.

    Does anyone know about htis process, the chemicals, etc.

    Also, how possible would it be to cross-process in C-41 chems?
     
  2. srs5694

    srs5694 Member

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    I don't know about cross-processing C-22 in C-41 or what would be involved in doing C-22 yourself, but as with your disc film, check with Rocky Mountain Film Laboratory if you want somebody else to process the film for you as C-22. I've never used their services, but I've heard good things about them.
     
  3. Photo Engineer

    Photo Engineer Subscriber

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    C22 films run through C41 will strip off the support. C22 films were hardened only to work at 75 deg F and at 100 will fall apart.

    C22 films in C41 at 75 degrees will not work correctly as they were designed for a ferricyanide bleach, not a Ferric EDTA bleach. Therefore, some dyes will not form properly (leuco dyes). C22 films also required benzyl alcohol and CD3 whereas C41 uses no benzyl alcohol and uses CD4.

    Gee, the only thing in common is the stabilizer.

    PE.
     
  4. htmlguru4242

    htmlguru4242 Member

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    Hmm ... Ifigured it would be different.

    The temperature problem wouldn't be a major problem, as its easier to process at 75F than it is at 100, less temperature control stuff...

    And ferricyanide bleach isn't terribly difficult or expensive to make.

    I was looking around online, and it seems that RA-4 chemistry uses CD-3, though there's no mention of benzyl alcohol (though I couldn't find any specific formulas). Perhaps modified RA-4 dev. with ferricyanide bleach, at 75f would work?
     
    Last edited by a moderator: Oct 18, 2005
  5. Gerald Koch

    Gerald Koch Member

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    One of the problems with color films since their inception is color cross-over causing unnatural color representation. There are two ways to prevent the color couplers from migrating within the emulsion. Kodak used a method where the couplers were located in microscopic resin beads. Agfa used a different method with a long side chain on each molecule which acted as sort of an anchor. Kodak's C-41 films now use a system similar to the Agfa method.

    Benzyl alcohol is required for C-22 films to penetrate into the resin beads so that the color developer and the color couplers can react to form dyes. Without this chemical you would not get any colors. Therefore, you cannot develop C-22 films in C-41 chemistry.
     
  6. 127

    127 Member

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    One of the Speedibrews C41 kits (Celer 41 I think) claims to be good for C-22 if run at room temperature.

    I tried it, and the results were pretty poor, but I suspect that's more to do with the film (and the skill of the operator) than the kit - colour film doesn't age well, and any C22 film you have is going to be WELL past it's best. Even if optimally processed the results are going to be pretty bad.

    Ian
     
  7. htmlguru4242

    htmlguru4242 Member

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    I realize, of course, that the results will suck, regardless if what I do to control the process. I'm not exaclty striving for good results, but it would be nice to try to get something out of old exposed fil, of shoot some cool distortion effects on the Kodacolor X that you find for $1.25 ish on EBay, or the odd box of AnscoChrome that turns up here and there ...

    What about just adding benzyl alcohol to the C-41 color developer??
     
  8. Photo Engineer

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    Gerald, sorry, this is wrong.

    Kodak and Agfa both used side chains from the start. The side chains on Kodak couplers were nonionic but the Agfa side chains were ionic (sulfonic acids or carboxylic acids).

    Kodak couplers were dissolved in organic solvents, while the Agfa couplers were dissolved in mild alkali and then placed directly into the gelatin. As a result, the Agfa couplers tended to thicken the gelatin and make coating more difficult. Therefore, in the mid 70s, Agfa, Fuji and Konishiroku (all users of the Agfa method btw) converted to the Kodak method of long chain non-ionic couplers in organic solvents.

    PE
     
  9. Photo Engineer

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    The RA4 developer was designed for chloride emulsions. The C41 and C22 developers were designed for optimum interimage with bromoiodide emulsions. I have no idea what would result, but a rebalance of RA4 would require the addition of NaBr, KI and benzyl alcohol at the least. Contact me if you want specifics, and I'll try to research it for you, otherwise I will not go rummaging around in old files.

    PE
     
  10. Paul Howell

    Paul Howell Member

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    A couple of years ago at the lab I used someone talked one the techs in running 10 rolls of old c22 though the developer, most of the emulsion came off and clogged the filters and contaminated the tanks. They had to break the unit down and clean it, took all day cost them a lot business and money.
     
  11. htmlguru4242

    htmlguru4242 Member

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    Thanks for the help, all ...

    Yeash, running C-22 through a C-41 machine does not sound like a good idea. I'd imagine that 100ºF will do quite a job on a 75ºF design emulsion...

    Thinking about it more carefully, maybe C-41 dev. would be a better modification candidate than RA-4?
     
  12. Gerald Koch

    Gerald Koch Member

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    Perhaps my choice of the term "resin beads" was not accurate although I have seen this term used before. A text that it consulted refers to "oily droplets".

    "Others though, notably those of the Ektachrome type, have oily droplets in the gelatine which have been used to suspend the color couplers. These droplets have a refractive index different from that of the gelatine when wet and give the film an opalescent appearance: the color balance also looks wrong when the film is wet."

    The Agfa films do not use this method depending on the weight of the coupler molecules to prevent drift in the emulsion.
     
  13. htmlguru4242

    htmlguru4242 Member

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    I'm pretty sure that some early Kodak films did in fact use resin beads. They were used to hold the couplers in place before a better method was devised.
     
  14. Photo Engineer

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    Gerald, Kodak did indeed refer to the droplets as either oily droplets or resin beads. This is related to the form that the dispersed coupler in solvent takes in the coating, ie whether it is 'soft' or 'hard' in nature. But both terms can be used.

    The problem I have with this is that Kodak has never moved to the Agfa method, as you state, but rather that all other companies have moved to the Kodak method.

    The sulfonic and carboxylic acids of the couplers used in the Agfa method are called "Fischer Couplers" after the inventor, and the Kodak couplers are sometimes referred to as "Kodacolor Couplers". The Fischer Couplers interfere with the rheology of gelatin and prevent efficient coating. Kodakcolor couplers do not.

    So, when the companies wishing to coat modern color films found this to be true, and wishing to make their coating the most efficient possible, they were forced to convert to the Kodak method either through license or by waiting until the patents expired.

    I have coated both types of couplers and I must say that the rheology of Fischer Couplers is a royal pain. Sometimes, the gelatin will not even set up. I have had to help clean a coating machine once due to that very problem. I brought my own putty knife.

    As for the opalescence, you may note that modern color products have far less than older films when wet. In fact, color paper has virtually none, whereas the original Type "C" paper of the 50s was very bad in this regard. When wet, that old color paper was just about only cyan in color. You could not see the other layers very well at all. A lot of progress has been made in this regard, and that has contributed to the improvements in grain and sharpness as well as opalescence.

    Essentially, you dissolved the Fischer coupler in base + water, added to gelatin and then neutralized to get a suspension of coupler in gelatin as the free acid or a salt depending on prep. With Kodakcolor couplers, you dissoslve them in a solvent, mix with a liquid 'resin' and then mix that with gelatin. Then you run this through a colloid mill (an industrial blendor with adjustable particle size settings) with the unit set for the size particle you want. You end up with something that looks like milk or cream which you then can go on to coat.

    In the case of the Kodacolor coupler, it is isolated from the silver halide and from the gelatin and so there is little interaction chemically. It makes better coatings.

    More than you ever wanted to know. Right?

    PE
     
  15. Gerald Koch

    Gerald Koch Member

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    Actually not, always interested in new information.

    I was unaware that the side chains were different for Kodak and Agfa. The way it had be explained to me was that for the Kodak C-22 films the couplers had a low molecular weight and had to fixed by the "resin beads". The Agfa couplers had a very long side chain which created drag and prevented drift within the emulsion.
     
  16. Photo Engineer

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    They are both basically 'ballasted' couplers. The ballast length may vary from coupler to coupler and from company to company but the Kodak couplers always ended in a nonionic moiety, whereas the Agfa couplers ended in an ionic moiety.

    During WWII there was free exchange between Agfa, Konica (then larger than Fuji) and Fuji which was a tiny company compared to the others. They all shared technology including color methodology. In the 60s, to foster efficient coating, all companies converted to the Kodak method or they just could not coat fast enough with few enough defects.

    Kodak never sold a color product using the Agfa method, but the other companies now all use the Kodak method.

    The ballast is there in all cases to prevent couplers from wandering. The bigger the ballast, the less the wander, but then the lower the ratio of 'dye' to 'inert' material in a coupler, so it is an art to balance off these forces in any design of coupler.

    The ballast also affects dye hue. The 'resin' or 'coupler solvent' also affects the hue of the final dye. Oh, one additional thing. The resin protects the dye from oxygen and other agents that cause fade, and therefore improves dye stability. Early Agfa type prints using similar couplers to Kodacolor couplers faded much more rapidly and it was not until the other companies started using the resin or droplet dispersions that they were able to begin to catch up in that area. Now, of course, it is a see saw battle in dye stability between Fuji and Kodak.

    PE