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Photo Engineer
06-23-2011, 09:05 AM
Lost in this all is the fact that nothing here seems to supply a means of hardening the polymer, but it does appear to have some properties that allow adhesion to the glass. Will it work on film support?

PE

jeffreyg
06-23-2011, 09:30 AM
All this is way above me. I am a dentist and use silane as a coupling agent to coat porcelain restorations prior to bonding them to teeth with resin cements to enhance the bond. Using it with the emulsion to coat glass plates is probably works in a similar fashion. As a dental product silane is over $50 for 12ml.

Just thought this may be of interest.

http://www.jeffreyglasser.com/

Marco B
06-23-2011, 10:19 AM
All this is way above me. I am a dentist and use silane as a coupling agent to coat porcelain restorations prior to bonding them to teeth with resin cements to enhance the bond. Using it with the emulsion to coat glass plates is probably works in a similar fashion. As a dental product silane is over $50 for 12ml.

Just thought this may be of interest.

Maybe a bit similar, from Wikipedia (http://en.wikipedia.org/wiki/Silane):

"Several industrial and medical applications exist for silane and functionalized silanes. For instance, silanes are used as coupling agents to adhere glass fibers (http://en.wikipedia.org/wiki/Fiberglass) to a polymer (http://en.wikipedia.org/wiki/Polymer) matrix, stabilizing the composite material (http://en.wikipedia.org/wiki/Composite_material). In other words, Silane coats the glass fibers to create better adhesion to the polymer chain. They can also be used to couple a bio-inert layer on a titanium (http://en.wikipedia.org/wiki/Titanium) implant (http://en.wikipedia.org/wiki/Prosthesis)."

wildbillbugman
06-23-2011, 10:59 AM
Hi Everyone,
It is quite possible that, in my recent emulsions, the formalin just sat there doing nothing. However,last night I did a quick search of crosslinkers for PVA. I not only found refferences to formalin and glyoxal, but to borax and even to bromine salts. Rather than argue over it, I plan to do some experements. I will compare the water solubility of films made from Kuraray silane / PVA with and without formalin and some other components of the emulsion.
Yes, silane coupling agents are toxic. That is one reason to use Kuraray product instead of pure coupling agents. But I think that, for me, it is way too late to worry about it now. I started working with organo-silanes in 1974. I am careful, but time is time and quantity is quantity.
Moe later,
Bill

wildbillbugman
06-23-2011, 10:00 PM
Bill, that thing you started looks very interesting to me! If you can share some more details about, I would be more than glad! I have a question though: did you use the silanized PVOH just for a better adherence to glass, or also due to its (somewhat) different properties compared to plain PVOH? At which temp does it set?
thanx in advance

Actualy, adhesion to glass is the whole thing. Although silane groups replacing hydroxyls will decreace watersolubility. In another study, I replaced all of the OH with silane . The resulting polymer was totaly insoluble in water. The Kuraray polymer is fairly easy to disolve in NEAR BOILING water. So there must be relatively few silanes, relative to hydroxyls.
Unlike gelatin, a PVA based emulsion dose not "set up". It must be alowed to dry.

wildbillbugman
06-23-2011, 10:14 PM
Hi PE and All,
My first water solubility tests indicate that niether formalin nor glyoxyl will cause a film of the kuraray polymer to become insoluble in Hot water. Both films eventualy dissolved, totaly. But the dried film, and the emulsion, are very hard on the gl;ass plate. Very difficult to scratch the surface or remove the film from the glass. I know at least one emulsion maker who makes gelatin plates, and never uses hardener.
Bill

T-grain
06-24-2011, 04:43 PM
Lost in this all is the fact that nothing here seems to supply a means of hardening the polymer, but it does appear to have some properties that allow adhesion to the glass. Will it work on film support?

PE

perhaps an interlayer of polydimethylsiloxane (polyvinylacetate) between the support and the silanized PVA could work?
I can tell from first-hand experience that styrofoam (or another non-cellulose but porous material) could be easily glued together with PVA or PVAc wood glue
maybe the subbed support has just the right surface texture.....

wildbillbugman
06-24-2011, 07:17 PM
Hi T-Grain,
Not to be arbitrarily negative, but why would you want to do that? The point of attaching silane groups to the PVA polymer is for good adhesion to glass. It realy dose work, and has been used for that purpose in all sorts of industrial application for many decades. As for PE's question about adhesion to film, IDK, and will let someone else find out. I live and breath glass. I wish that the entire planet and everything in it could be glass, and, like my heart,easily broken.:D

wildbillbugman
06-24-2011, 07:25 PM
Kirk,
Beavis and Butthead???!!!. I realy would have expected better from you. At leat South Park, which is "High Brow" compared to B&B. Seriously," Dude"!

Bill

T-grain
06-25-2011, 05:47 AM
Hi T-Grain,
Not to be arbitrarily negative, but why would you want to do that? The point of attaching silane groups to the PVA polymer is for good adhesion to glass. It realy dose work, and has been used for that purpose in all sorts of industrial application for many decades. As for PE's question about adhesion to film, IDK, and will let someone else find out. I live and breath glass. I wish that the entire planet and everything in it could be glass, and, like my heart,easily broken.:D

I was referring to PE's question about adhesion on film (where there's no silanol groups, but acetate etc. instead). And maybe such a layer could provide good adhesion for the silanol modified PVA (emulsion).

wildbillbugman
06-25-2011, 11:55 AM
T-grain,
Thanks for the clarification.
Everyone,
Last night, I poured 11 plates. They are not dry yet ( humid here). But I did run a fogging test,on glass, yesterday. That looks good. Hopefuly, I will take some shots tomorow and post them here.
Bill

wildbillbugman
06-25-2011, 12:03 PM
All this is way above me. I am a dentist and use silane as a coupling agent to coat porcelain restorations prior to bonding them to teeth with resin cements to enhance the bond. Using it with the emulsion to coat glass plates is probably works in a similar fashion. As a dental product silane is over $50 for 12ml.

Just thought this may be of interest.

http://www.jeffreyglasser.com/

I have seen these kits on ebay. Do you hapen to know, what is the functionality of the organic site?
Bill

wildbillbugman
06-27-2011, 07:28 PM
Hello to all, Everyone is gonna laugh at me because the scans of my plates are so uglt. But the plates themselves look much better. To coat the plates I used a 250 micron wire coating rod. This produced a wet coating 10mils thick. That is too much. I'll be getting a new rod that will lay down 7-8 mils. But it ain't here yet. Most of the obvious flaws, gaps in coating etc., are do to my clumsiness with wet plates and an IR monocle. Makes everything look thurther away than it is.. I have attached two negatives and the formula wth procedure. The actual plates, either just dryed or processed, are very glossy and hard. They remind me of obsidien. The are difficult to scratch and impossible to gough I am gonna make a new batch, just like this one, and use Denise Ross's coating well and a coating rod to try to get a wet thickness of about 7 mills.
Note that I wash the dried plates, not the emulsion,as PVA will not set up at cold temperatures, like gelaten (think: murdered cow,mother of baby calves;)
Bill

wildbillbugman
06-27-2011, 07:37 PM
I forgot to mention that this is a fast emulsion, I grossly over-exposed several plates, befor I arived at f22 for 1 second, in bright miday sunlight..
Bill

Marco B
06-28-2011, 02:25 AM
I forgot to mention that this is a fast emulsion, I grossly over-exposed several plates, befor I arived at f22 for 1 second, in bright miday sunlight..
Bill

Well, that brings hand held shooting in the picture, 1/128th of a second at F2 :laugh:

The coatings are messy, but they look promising. Well, what do I have to tell, with zero experience coating plates...

Anyway, I hope you don't mind, but I took the liberty to "turn your negatives into positives" (with a thanks to MurrayMinchin here on APUG for making me see this differently, see the APUG "Quote" thread (http://www.apug.org/forums/forum47/78410-quote-thread.html)), as I was curious to see a bit better what was there.

3632336324

T-grain
06-28-2011, 09:31 AM
Bill, there is nothing to laugh about your results. They really look promising!
As for the PVA, once dried-hardened, and when you soak the plates in the chemistry for processing, do they swell considerably (visibly)?
How long does it take to dry the plates once processed (I know there are many factors)?
thanks for sharing!

wildbillbugman
06-28-2011, 11:24 AM
T-grain,
Here is a big difference between this emulsion and every gelatin emulsion that I have worked with. The PVA emulsion stays hard through all cold-water processes. I had no problem when I washed the dry panels in cold water for 3 hours. The one exception is at some corners and edges, where the film was so thick that it had not dried fully. I have always been a putz with a coating rod, even in daylight. Under IR I am worse. But flat dry areas do not buge.
After I removed the plates from the final rinse, I left them alone for 2 hours. But I think that an evenly coated plate would be dry in less than an hour.
Bill

wildbillbugman
06-28-2011, 11:43 AM
Macro B,
Certainly, the positives look worse than the negatives. But I ain't done yet!
Bill

Marco B
06-28-2011, 12:29 PM
Macro B,
Certainly, the positives look worse than the negatives. But I ain't done yet!
Bill

Good to hear, keep us updated!

wildbillbugman
07-04-2011, 12:57 PM
Hello to All,
I have evaluated another batch of emulsion based on Kuraray R 1130 instead of gelatin
The two changes in the emulsion were: A reduced polymer leval. This batch of R 1130 is 14% instead of 23% in the last emulsion. B) NH4I instead of KI
All glass plates were coted with emulsion using a modified glass frame and a #40 wire coating rod;Wet thickness 8 mils; Dryed 24 hours; washed for 3 hours;dryed overnight
I have a dewetting problen. As of now the emulsion contains no surfactant or alcohol. Tonight, I will coat more plates with this emulsion + surfactant. I am convinced that this is a dewetting issue and not an issue of frilling or lifting of emulsion.
Pre- soak- 10 minutes
D-19- 9 minutes
Stop-Dillute acetic acid
Fix - 10% Sodium Thiosulfate, 10 minutes
Note that there are :whistling: red flowers arouned 10:30 o'clock.
Final rinse-1 houer