B&W Reversal with Hydrogen Peroxide

[relistan]

If Carey Lea silver is formed by accident in the H2O2 bleach method it might have lower solubility than normal silver halides and thus not be washed out when you fix the film.

Thank you for this explanation! This is sort of what I had picked up from reading about it after you posted before. I didn't know about the layer in color films and was a little confused after some of the other discussion. That clears it up a lot, so thanks. And I think you might be right. It seems to happen when the bleaching is very aggressive, which happens when it's working on a film with a lot of silver. Fomapan R100, with its silver anti-halation layer lights off quick a reaction in the bleach. Silvermax has a a lot of silver in it as well. In that fast bleaching condition is when you see staining. This can also happen when the bleach is more saturated with silver ions (I presume) from having bleached a few films before. This is all just from experience with it so far, but I'm trying to reason about how it happens and I think what you are saying fits.

 

[Lachlan Young]

I see, that silver anti-halation layer on the Fomapan R100 that dissolves in the bleach like crazy is a Carey Lea silver layer on the backing. That helps tie things together for me. Yeah, Silvermax I normally use as a negative film, obviously, now that I know what folks were referring to in the CLS layer: it definitely does not have one. But the effect is still possible with any silver as far as I understand. So highlights could have a CLS effect as I understand it.

Black colloidal silver has been disclosed as being used in the anti-hal underlayer on C-41 films.

I'd also point out that all these 'alternative' bleaches don't seem to offer any real advantages over appropriately sequestered acidified permanganate bleach - and that despite patenting a number of peroxide bleaches neither Kodak nor Agfa changed their BW reversal processes from acidified permanganate is, I'd suggest, significant.

 

[Raghu Kuvempunagar]

Usually when we use the term "Carey Lea Silver" we mean this light filter layer which is found in most color films. I'm using it generically to refer to silver compounds which have a color. I think some might have been formed in this peroxide bleach method. I didn't mean to suggest that black and white film would contain a light filter Carey Lea layer which is specific to color film.

Thanks for the clarification. Yes, it's possible that some colored silver compound is formed due to the impurities in vinegar. Is it also possible that the phenolic compounds in the vinegar (including gallic acid) form stains on the film after getting oxidized by the bleach? Interestingly, OP reported that the stain disappeared when the film was left hanging in daylight. Stains formed by phenolic compounds typically degrade after exposure to UV. Does that happen with Carey Lea silver compounds too?

 

[relistan]

It seems that there are two kinds of staining, now that I've let that other roll hang in the window and seen no change. There is the subtle brown, which appears unaffected by UV light and the lighter yellow, rather ugly staining that appears to fade in UV light. I also think that the most recent batch of bleach I used was made from white vinegar I obtained rather than the distilled malt vinegar. The distilled stuff may be much cleaner. The roll I developed with my daughter (last posted) was with the original bleach using the distilled stuff. I will test that theory this weekend.

 

[Lachlan Young]

It seems that there are two kinds of staining, now that I've let that other roll hang in the window and seen no change. There is the subtle brown, which appears unaffected by UV light and the lighter yellow, rather ugly staining that appears to fade in UV light. I also think that the most recent batch of bleach I used was made from white vinegar I obtained rather than the distilled malt vinegar. The distilled stuff may be much cleaner. The roll I developed with my daughter (last posted) was with the original bleach using the distilled stuff. I will test that theory this weekend.

You may have generated dichroic fog or similar.

 

[YoIaMoNwater]

It seems that there are two kinds of staining, now that I've let that other roll hang in the window and seen no change. There is the subtle brown, which appears unaffected by UV light and the lighter yellow, rather ugly staining that appears to fade in UV light. I also think that the most recent batch of bleach I used was made from white vinegar I obtained rather than the distilled malt vinegar. The distilled stuff may be much cleaner. The roll I developed with my daughter (last posted) was with the original bleach using the distilled stuff. I will test that theory this weekend.

The brown stain is definitely silver. It looks really similar to how western blots (protein detection on membrane) are stained with silver (if you google 'western blot silver staining' you'll see what I'm talking about). I've been following this thread and never heard of Carey Lea silver until now and the description of how different silver grain size affects color is applicable here.

Black colloidal silver has been disclosed as being used in the anti-hal underlayer on C-41 films.

I'd also point out that all these 'alternative' bleaches don't seem to offer any real advantages over appropriately sequestered acidified permanganate bleach - and that despite patenting a number of peroxide bleaches neither Kodak nor Agfa changed their BW reversal processes from acidified permanganate is, I'd suggest, significant.

I feel like the whole point of OP experimenting with H2O2 bleach is to try something novel. I'm a scientist and optimizing a protocol is tedious and time consuming. But once you get some decent results the self satisfaction is worth it. However, this feeling can definitely be the opposite if nothing works... I'm kinda rambling now and should start working on my PhD thesis...lol.

 

[relistan]

I feel like the whole point of OP experimenting with H2O2 bleach is to try something novel. I'm a scientist and optimizing a protocol is tedious and time consuming. But once you get some decent results the self satisfaction is worth it. However, this feeling can definitely be the opposite if nothing works... I'm kinda rambling now and should start working on my PhD thesis...lol.

Thanks! Yeah, I am no scientist, but I do think that if people don't experiment with stuff we'll never make any more progress. I don't see a lot of research coming from 20 years ago on out from the big companies. Maybe there is a little space for our community to figure something out. If so, great! But we won't know if we don't try things. I look at Caffenol as a community success, for example. A lot of people have gotten a lot of joy and some nice art from that invention. It started in a university class, then was continuously improved by people sharing that information with each other. Maybe there are other places we can do that.

 

[relistan]

I have found a pretty interesting Konica patent! https://patentimages.storage.googleapis.com/0a/67/9c/6e39d5821bd5d7/US4277556.pdf This may be the source of some of this stuff. It's referenced in a few of the later patents. There are a number of interesting things in here, some of which confirm things I have seen and theorized and some things that others have theorized as well. This may be of particular interest to @Raghu Kuvempunagar, @falotico, @YoIaMoNwater, and @kentanghk.

First, the most interesting thing: they say this is not just a bleach, but a bleach-fixing solution, and they propose it for use in color processing. Obviously in the form I am using it here, it's a reasonably good bleach but not a very good fixing agent. However, if I am reading this properly, this may explain a few things:

1. The fact that I can basically put almost no thiosulphate in the first developer without getting very low Dmax
   
2. The fact that a process with no solvent in the first developer can render very good results even without any of the development accelerators that other patents (e.g. Scala process) use
3. The fact that it totally wiped all the sliver off of Fomapan 100R, both developed and undeveloped

Interestingly, the Kodak patent does not claim any bleach-fixing, only bleaching for a very similar bleach. So I am not quite sure what to say about that.

Regarding the accelerated bleaching I saw once I had process part of a roll of Fomapan R100 and the silver layer pretty immediately dissolved, and the fact that the bleach gets stronger with use:

"The bleach-fixing solution of this invention can some times be extremely promoted due to silver ions dissolved out from the light-sensitive silver halide color photographic materials treated and other substances dissolved out from said photographic materials. When metallic silver is dissolved in advance into the bleach fixing solution of this invention, the bleaching ability of the solution can often be extremely promoted. There fore metallic silver can be in advance added into the solution." section 8 47-57

I believe this is also what is behind the Kodak patent adding silver nitrate or other silver compounds like @kentanghk used in his version of the bleach.

They intentionally set the pH of the bleach in the range of 3-4.5, using potassium hydroxide (section 8 46-47). This may help to contain the runaway peracetic acid reaction. Additionally they address the blistering that can occur, speaking about how much peroxide is present:

"When the added amount is greater than necessary, the reaction becomes extremely active and sometimes foams, and so-called blisters occur on the surface of the treated film. Therefore, it is necessary to determine an amount of hydrogen peroxide to be added in every case to get the optimum result." section 6 8-14

This confirms what I have seen, which is that when the reaction is in the "fast mode" it causes the most damage.

They talk about the same thing I had researched early on, that silver acetate should dissolve well into the solution up to about 1g/L:

"In fact, in cases where an organic acid, especially acetic acid as the organic acid, is used, the solution can dissolve out silver ions in the solution to the extent of 1 g/l, and when large amounts of photosensitive materials are treated, more silver salt than is dissolved precipitates in fine particles" section 9 21-26

Regarding staining, it may be that the presence or absence of stains is related to pH:

"In these treatment processes, a stain-removing bath was used but there could be found no substantial difference in stain density in the highlight part irrespective of use of it. But in cases where a sample to be tested has a colloidal silver antihalation layer, it was found that the use of the stain-removing bath is effective. Further, in cases where pH of the bleach-fixing solutions was adjusted to from 2.5 to 3.5, the same results were obtained as in Table 3 [editor: i.e. no staining]." Section 23 21-29.

In many of the bleaches they are using about 1.5% peroxide with *much* more acetic acid, but adding various salts to accelerate the bleaching. This may be a route to less blistering. And maintaining the pH properly may be the route to not staining, at least the part that is not related to organic materials from the vinegar.

This is one of the faster of the embodiments listed, with a clearing time of 1 minute 35 seconds:

I am not sure from reading this if the HEDP/etidronic acid is serving as a chelating compound or active in the reaction. It is present in some of the embodiments and not others. It looks hard to obtain. EDTA is not and might be substituted? Also, I would think that for our purposes we would *not* want to have any chloride in there since it might rehalogenate? Also, we don't want to fully bleach-fix so I am not sure if targeting this is ideal.

 

[Raghu Kuvempunagar]

I have found a pretty interesting Konica patent! https://patentimages.storage.googleapis.com/0a/67/9c/6e39d5821bd5d7/US4277556.pdf

The key take away seems to be that a combination of low concentration peroxide with acetic/citric acid and Etidronic acid with pH adjusted to be between 2.0 - 5.5 is powerful enough to remove the negative image while not causing blisters:

"the use of ... of the lower alkyl aliphatic carboxylic acid ... and ... an alkylidene diphosphonic acid ... does not cause blistering to occur"

"Such a combination gives unexpected results in that the bleaching reaction is greatly promoted in comparison with the use of two components consisting of hydrogen peroxide and carboxylic acid or hydrogen peroxide and alkylidene diphosphonic acid."

If you can get Etidronic acid easily, and the formulation works for you, go for it.

 

[Raghu Kuvempunagar]

It looks hard to obtain.

It seems to available here and here.

 

[YoIaMoNwater]

I have found a pretty interesting Konica patent! https://patentimages.storage.googleapis.com/0a/67/9c/6e39d5821bd5d7/US4277556.pdf This may be the source of some of this stuff. It's referenced in a few of the later patents. There are a number of interesting things in here, some of which confirm things I have seen and theorized and some things that others have theorized as well. This may be of particular interest to @Raghu Kuvempunagar, @falotico, @YoIaMoNwater, and @kentanghk.

First, the most interesting thing: they say this is not just a bleach, but a bleach-fixing solution, and they propose it for use in color processing. Obviously in the form I am using it here, it's a reasonably good bleach but not a very good fixing agent. However, if I am reading this properly, this may explain a few things:

1. The fact that I can basically put almost no thiosulphate in the first developer without getting very low Dmax
   
2. The fact that a process with no solvent in the first developer can render very good results even without any of the development accelerators that other patents (e.g. Scala process) use
3. The fact that it totally wiped all the sliver off of Fomapan 100R, both developed and undeveloped

Interestingly, the Kodak patent does not claim any bleach-fixing, only bleaching for a very similar bleach. So I am not quite sure what to say about that.

Regarding the accelerated bleaching I saw once I had process part of a roll of Fomapan R100 and the silver layer pretty immediately dissolved, and the fact that the bleach gets stronger with use:

"The bleach-fixing solution of this invention can some times be extremely promoted due to silver ions dissolved out from the light-sensitive silver halide color photographic materials treated and other substances dissolved out from said photographic materials. When metallic silver is dissolved in advance into the bleach fixing solution of this invention, the bleaching ability of the solution can often be extremely promoted. There fore metallic silver can be in advance added into the solution." section 8 47-57

I believe this is also what is behind the Kodak patent adding silver nitrate or other silver compounds like @kentanghk used in his version of the bleach.

They intentionally set the pH of the bleach in the range of 3-4.5, using potassium hydroxide (section 8 46-47). This may help to contain the runaway peracetic acid reaction. Additionally they address the blistering that can occur, speaking about how much peroxide is present:

"When the added amount is greater than necessary, the reaction becomes extremely active and sometimes foams, and so-called blisters occur on the surface of the treated film. Therefore, it is necessary to determine an amount of hydrogen peroxide to be added in every case to get the optimum result." section 6 8-14

This confirms what I have seen, which is that when the reaction is in the "fast mode" it causes the most damage.

They talk about the same thing I had researched early on, that silver acetate should dissolve well into the solution up to about 1g/L:

"In fact, in cases where an organic acid, especially acetic acid as the organic acid, is used, the solution can dissolve out silver ions in the solution to the extent of 1 g/l, and when large amounts of photosensitive materials are treated, more silver salt than is dissolved precipitates in fine particles" section 9 21-26

Regarding staining, it may be that the presence or absence of stains is related to pH:

"In these treatment processes, a stain-removing bath was used but there could be found no substantial difference in stain density in the highlight part irrespective of use of it. But in cases where a sample to be tested has a colloidal silver antihalation layer, it was found that the use of the stain-removing bath is effective. Further, in cases where pH of the bleach-fixing solutions was adjusted to from 2.5 to 3.5, the same results were obtained as in Table 3 [editor: i.e. no staining]." Section 23 21-29.

In many of the bleaches they are using about 1.5% peroxide with *much* more acetic acid, but adding various salts to accelerate the bleaching. This may be a route to less blistering. And maintaining the pH properly may be the route to not staining, at least the part that is not related to organic materials from the vinegar.

This is one of the faster of the embodiments listed, with a clearing time of 1 minute 35 seconds:

View attachment 262995

I am not sure from reading this if the HEDP/etidronic acid is serving as a chelating compound or active in the reaction. It is present in some of the embodiments and not others. It looks hard to obtain. EDTA is not and might be substituted? Also, I would think that for our purposes we would *not* want to have any chloride in there since it might rehalogenate? Also, we don't want to fully bleach-fix so I am not sure if targeting this is ideal.

Really cool find! As for HEDP, I have never used it before but I don't see why you can't substitute it with EDTA. I used EDTA a lot in my research lab to remove nickel ions from columns for protein purification, so the function of EDTA as metal chelator should be the same for HEDP.

It seems to available here and here.

I don't know if you can buy stuff from Sigma if you're not associated with a company or research institute. For our lab we had to get our lab manager involved for orderings and even then some materials require additional waivers.

 

[relistan]

It seems to available here and here.

I had found it from Sigma-Aldrich, but there is no way I'm paying that for it . And I'm not sure I can order there. As @YoIaMoNwater mentioned you have to sign up and provide documentation. The Moersch link looks more interesting. Thanks!

 

[relistan]

Really cool find! As for HEDP, I have never used it before but I don't see why you can't substitute it with EDTA. I used EDTA a lot in my research lab to remove nickel ions from columns for protein purification, so the function of EDTA as metal chelator should be the same for HEDP.

I've already got some EDTA, so I will try it out! I am running out of peroxide, though, and Brexit has screwed up my channel for buying it.

 

[kentanghk]

The patent relistan posted was very interesting and I did some preliminary test after reading.

I developed the lower half of a strip of Lucky SHD 100 film in HC110A with random amount of sodium carbonate added for 5 minutes.
Then I cut a small piece of the film into the bleach. The film was bleached for 10 minutes at 38C.
The bleached film was then developed again in the HC110-sodium carbonate mixture and then it was washed and dried.

I tested four bleach formulae.

Bleach C
Hydrogen peroxide (35%) 28.5g/L
Potassium hydrogen phthalate 7.15g/L
pH adjusted by NaOH to pH5

Bleach D
Hydrogen peroxide(35%) 50mL/L
Glacial acetic acid 40mL/L
EDTA disodium salt dihydrate 0.54g/L
pH adjusted by NaOH to pH4

Bleach E
Hydrogen peroxide(35%) 60mL/L
Glacial acetic acid 50mL/L
pH adjusted by NaOH to pH4.5

Bleach F
Citric acid dihydrate 45g/L
Hydrogen peroxide (35%) 85mL/L
Silver nitrate 0.8g/L
pH adjusted by NaOH to pH4.5

And here is the result.

Bleach C worked surprisingly well. However blistering was observed in all test strips and I wonder if it is due to the poor hardening of lucky film or lack of agitation. I have not observed such blistering in previous test film.

Acetic acid-peroxide bleach worked but looks like the bleaching was not complete. Maybe it takes longer than 10 minutes to bleach completely?

The bleach-fix described in the Konica patent did not fix the image in my test but I think it is probably good for our application on black and white materials.

I might develop a roll of FP4 over the weekend with Bleach C to see how it perform on real film.

 

[relistan]

Bleach C worked surprisingly well. However blistering was observed in all test strips and I wonder if it is due to the poor hardening of lucky film or lack of agitation. I have not observed such blistering in previous test film.

Acetic acid-peroxide bleach worked but looks like the bleaching was not complete. Maybe it takes longer than 10 minutes to bleach completely?

The bleach-fix described in the Konica patent did not fix the image in my test but I think it is probably good for our application on black and white materials.

I might develop a roll of FP4 over the weekend with Bleach C to see how it perform on real film.

This is super interesting! Thanks for doing that and posting the results! I am glad that there was no notable bleach-fixing action. That would actually be counter to what we want, as I mentioned!

Interesting how badly the acetic acid/EDTA peformed (sample D). I would have expected it to behave somewhat better than the the acetic acid alone. Is it correct that the EDTA sample (D) does not exhibit much blistering? That might be an avenue worth pursuing, if so. I had ordered some, which arrived yesterday, to try as well.

Acetic acid-peroxide bleach worked but looks like the bleaching was not complete. Maybe it takes longer than 10 minutes to bleach completely?

The acetic acid sample looks like it did not fully bleach: this is exactly what I've seen on unfinished bleaching. It's using a much higher amount of acetic acid and much less peroxide, so that's instructive.

Some questions that would be very interesting to know the answers to if you have them:

1. What was the bleaching behavior? Did you see a lot of bubbling? Was it the same for all samples?
2. Did any of them bleach faster or slower in the 10 minute window?
3. If you look closely at the emulsion (e.g. through a loupe, or scanned) do they all exhibit the same amount of damage?

Thanks for all of that!

 

[kentanghk]

Interesting how badly the acetic acid/EDTA peformed (sample D). I would have expected it to behave somewhat better than the the acetic acid alone. Is it correct that the EDTA sample (D) does not exhibit much blistering? That might be an avenue worth pursuing, if so. I had ordered some, which arrived yesterday, to try as well.

Yes, the bleach with EDTA does not exhibit much blistering and it seems to bleach in a slower and milder way. In fact I thought it didn't work at all as no bleaching effect was observed after 5 minutes of bleaching.

What was the bleaching behavior? Did you see a lot of bubbling? Was it the same for all samples?

I saw lots of bubbling on the emulsion slide of film in bleach C and F. I don't remember about bleach E but not much bubbles were observed in bleach D.

Did any of them bleach faster or slower in the 10 minute window?

Bleach C and F worked much faster than the acetic acid-peroxide bleach and I think they finished bleaching in about 7 minutes. The two acetic acid-peroxide bleach worked much slower.

If you look closely at the emulsion (e.g. through a loupe, or scanned) do they all exhibit the same amount of damage?

I left the film in lab. I'll take some closer look on Friday.

I will probably try a combination of EDTA and phthalate to see if I can get a better version of bleach C.

 

[Raghu Kuvempunagar]

@kentanghk: The Konica patent shared by @relistan clearly says this:

"Such a combination [of peroxide with lower alkyl aliphatic carboxylic acid and alkylidene diphosphonic acid] gives unexpected results in that the bleaching reaction is greatly promoted in comparison with the use of two components consisting of hydrogen peroxide and carboxylic acid or hydrogen peroxide and alkylidene diphosphonic acid."

You need Etidronic acid to both get faster bleaching action and prevent blister formation.

 

[relistan]

@kentanghk: The Konica patent shared by @relistan clearly says this:

"Such a combination [of peroxide with lower alkyl aliphatic carboxylic acid and alkylidene diphosphonic acid] gives unexpected results in that the bleaching reaction is greatly promoted in comparison with the use of two components consisting of hydrogen peroxide and carboxylic acid or hydrogen peroxide and alkylidene diphosphonic acid."

You need Etidronic acid to both get faster bleaching action and prevent blister formation.

It does say that but they also present other bleaches (as above) which they claim also don't blister. I will try to obtain etidronic acid from Moersch, but that's not really an easily accessible chemical so if one of the others works, I would rather not need it.

 

[Lachlan Young]

It does say that but they also present other bleaches (as above) which they claim also don't blister. I will try to obtain etidronic acid from Moersch, but that's not really an easily accessible chemical so if one of the others works, I would rather not need it.

Suvatlar sell Dequest 2010/ Etidronic acid as Fotoplex.

 

[relistan]

Suvatlar sell Dequest 2010/ Etidronic acid as Fotoplex.

Yes, which I believe I have to order through Moersch. But if you know a better way, I'll definitely try.

 

[relistan]

Email has been sent to Wolfgang Moersch regarding etidronic acid. Meanwhile I'm still trying to get some more peroxide now that Brexit has F'ed up my supply

EDIT: I have ordered some 12% peroxide from the UK so I can dilute down as needed. We'll see how badly Irish customs bungle this.

 

[YoIaMoNwater]

@kentanghk: The Konica patent shared by @relistan clearly says this:

"Such a combination [of peroxide with lower alkyl aliphatic carboxylic acid and alkylidene diphosphonic acid] gives unexpected results in that the bleaching reaction is greatly promoted in comparison with the use of two components consisting of hydrogen peroxide and carboxylic acid or hydrogen peroxide and alkylidene diphosphonic acid."

You need Etidronic acid to both get faster bleaching action and prevent blister formation.

Etidronic acid isn't a alkylidene though. Unless the alkylidene portion isn't necessary then I suppose it would work. Still, @relistan you should continue with that Raghu suggested with a combination of acetic acid and etidronic acid (if you manage to get some). I don't know how one would obtain a alkylidene diphosphoric acid without synthesizing it yourself or know a organic chemist.

 

[Raghu Kuvempunagar]

Etidronic acid isn't a alkylidene though. Unless the alkylidene portion isn't necessary then I suppose it would work.

The patent itself mentions Etidronic acid as a representative alkylidene diphosphonic acid. Quoting from the patent: "Representative alkylidene diphosphonic acids having formula (III) are as follows: 1-hydroxyethylidene-1,1- diphosphonic acid, methylenediphosphonic acid, ethyli dene-diphosphonic acid, 1-hydroxybutylidene-1,1- diphosphonic acid, 1-hydroxypropylidene-1,1-diphos phonic acid and the like."

 

[YoIaMoNwater]

The patent itself mentions Etidronic acid as a representative alkylidene diphosphonic acid. Quoting from the patent: "Representative alkylidene diphosphonic acids having formula (III) are as follows: 1-hydroxyethylidene-1,1- diphosphonic acid, methylenediphosphonic acid, ethyli dene-diphosphonic acid, 1-hydroxybutylidene-1,1- diphosphonic acid, 1-hydroxypropylidene-1,1-diphos phonic acid and the like."

Hm interesting, I thought there has to be a double bond with carbon somewhere. Guess my nomenclature is rusty.

 

[relistan]

Etidronic acid isn't a alkylidene though. Unless the alkylidene portion isn't necessary then I suppose it would work. Still, @relistan you should continue with that Raghu suggested with a combination of acetic acid and etidronic acid (if you manage to get some). I don't know how one would obtain a alkylidene diphosphoric acid without synthesizing it yourself or know a organic chemist.

Thanks. Yeah, I intend to try EDTA first because there is another Kodak patent that uses it in combination with some salts, and because I think it actually looks reasonably promising from the work @kentanghk did above. I will try to find that patent and post it.

But, I wrote to Wolfgang Moersch about getting ahold of HEDP/editronic acid and we'll see if I hear back. Unless @Lachlan Young knows how to buy direct from Suvatlar that seems like the only reasonable route to get it.

BTW: I saw this in the Wikipedia entry on HEDP: "It is also used in peroxide bleaching to prevent degradation of peroxides by transition metals." I wonder if this is the only real purpose it's serving?