> Yes, that is all correct and all that I know. But what is actually a
> photopolymer ?
Photopolymer is a very broad term. The trite answer is that it is a
polymer that responds in some way to light. It is likely that the
definition even extends to polymers formed through the action of light
during the polymerization process. A polymer is simply a molecule created
by linking smaller molecules together to form a bigger molecule. Starch
for instance is made by linking sugar molecules together. Gelatin
consists of many linked subchains of molecules and is also likely
considered to be a polymer. Mixing something like gelatin with a
dichromate makes a substance that will cross-link the molecular structure
of two or more of the gelatins' molecular chains together when exposed to
light. This is the hardening action that you get with a dichromated
colloid solution. It is probably correct to say that the dichromated
gelatins are photopolymers.
The really difficult part in answering this is that some of the processes
you are trying to find out about are probably kept as proprietary trade
> You see, what I am heading at is to find out for sure, wheither this last
> mentioned type is free for dichromates, as I hope it is.
I'm not certain that the term photopolymer is specific enough. I would
guess that some might use dichromates while others may not. Based on the
answers you've received so far this seems to be the case.
> I have been working with that type of product from Murakami, Japan. That is
> called Aquasol and is used for waterbased colors and textile printing. I
> have been in contact with Murakami and they assured me, that photopolymers
> work on the molecular structure change principal and not a chemical
Well, I'd say that technically a molecular change constitutes a chemical
change since it probably modifies the overall shape or connectivity of
the molecule. On the other hand, it probably doesn't rely on a reaction
between another chemical component in the mix. That probably implies that
there isn't a dichromate in the stuff, but may not guarantee it. Did you
simply ask if this was a dichromate free formulation? You can probably
get a yes/no answer to that. Asking how their photopolymer solution works
may be treading on proprietary company secrets.
> Chemists, are you there ?
I'm not a chemist, just an electrical engineer. Also, you might consider
that just because something doesn't contain dichromates it isn't