Wallpaper paste is made from wheat. The stickiness comes from the glutin - what makes pasta stick to the pan when it dries. Components of wallpaper paste are not soluble therefore the apparent corseness of the adhesive.
Mucilage is a protein derrived from those found in bone and other hard animal structures. It is completely soluble in water. I'm not sure I would recommend either for use in toner transfer applications.
Photographic film uses a very specific gelatin made from cow bones as the base for the emulsion which carries the photosensitive components of the film. When placed in water to develop the film it does swell, but it does not dissolve rapidly. I have been told by reliable sources in Kodak and the DuPont X-ray film business (now this was 25 or 30 years ago) that their primary source for photographic film gelatin is India because the cow bones have to be exposed to ultraviolet light from the sun for many years - just plain old cow bones just don't seem to work very well.
I think our best bet for a paper coating will be a synthetic polymer that is water soluble and that can be applied by a solvent process so the paper substrate doesn't deform. Whatever is in hairspray seems to be a reasonable starting point, however there are hundreds of materials that fill this description, most of which fall into the categories of polyalcohols (CIBA Pluronic series or DuPont Elvanol) and copolymers of ethylene and acrylic acid or other reactive organic acids (DuPont Nucrel).
None of these are high temperature polymers and the problem will be stability at the temperatures required for toner transfer.
Sorry for the chemistry lesson - I don't know how to explain it any other way....
----- Original Message -----
From: Phil
To: Homebrew_PCBs@yahoogroups.com
Sent: Tuesday, November 16, 2004 5:14 PM
Subject: [Homebrew_PCBs] Re: Hairspray
--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
>
> On Tue, 16 Nov 2004 20:10:44 -0000, Phil <phil1960us@y...> wrote:
>
> >
> > mucilage is a kind of glue. Its used for gluing paper together. I
> > believe that "lickable" postal envelopes use mucilage.
> >
>
> much like wallpaper paste then?
>
I dont think they are exactly the same. wallpaper paste seems
"coarse" to me, mucilage seems much smoother, slimier. I suspect the
origin of the word in mucus which would be about right.
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