Re: Adhesion: Silane and gum

> No, I didn't use acetone on both sides of the glass, but I'm not sure I
> understand the question.

Sorry, I meant, did you treat all glasses with acetone (you said: "The wet
gum coating didn't stick as well to the silane-treated glass as it does to
plain glass ..."), the "plain glass" was also treated with acetone?

> Would IPA be a better
> solvent? Weren't you the one who recommended acetone?

I've heard of acetone or methanol in that context but assume IPA would also
work.

Martin

----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Saturday, March 05, 2005 8:22 AM
Subject: Re: Adhesion: Silane and gum

> MARTINM wrote:
> >
>
> > Looks like the aminopropyltriethoxysilane has not sufficient "affection"
> > vis-a-vis gum (the good news being there are several hundreds of silanes
to
> > try).
>
> Yippy-skip! :-) Actually, I can't think of any reason why I would
> pursue this line of inquiry any further. I was willing to try it once,
> since people I respect seemed so sure it would work, but I sure am not
> willing to try hundreds, or even dozens, of different ones on the odd
> chance of finding one that would bond chemically to crosslinked gum. (If
> nothing else would stop me, the expense alone would prohibit this
> fishing expedition, but I'm also not interested in spending any more of
> my time or energy on it).
>
>
> >
> > > > The wet gum coating didn't stick as well to the silane-treated glass
> > > > as it does to plain glass (...).
> >
> > Did you use acetone on both glass sides? I ask because acetone (unless
of
> > optical/spectroscopic grade) might leave impurities on glass.
>
> No, I didn't use acetone on both sides of the glass, but I'm not sure I
> understand the question. I'm using non-glare glass which is etched on
> one side; the etched side is the viewing side. So there's only one side
> to put the acetone on. Am I missing something? Would IPA be a better
> solvent? Weren't you the one who recommended acetone? At any rate, it
> seems like this would only be an issue for the bonding of the silane to
> the glass, and that wasn't a problem, it stuck like cement.
>
> > > > The exposed and hardened gum frilled off the silane-treated glass
> > > > exactly as it would from plain untreated glass.
> >
> > Would it help adding a few drops of surfactant to the coating solution?
>
> I don't see why it would.
>
> Katharine
>
>
> >
> > ----- Original Message -----
> > From: "Katharine Thayer" <kthayer@pacifier.com>
> > To: <alt-photo-process-l@sask.usask.ca>
> > Sent: Friday, March 04, 2005 3:17 PM
> > Subject: Re: Adhesion: Silane and gum
> >
> > > P.S. Whoever said that silane might be difficult to remove from glass
> > > wasn't just woofin'. I've spent an hour and five razor blades
scraping
> > > away at it and there are still places where it just won't come off. If
> > > this were just regular window glass, I'd toss it, but this is
non-glare
> > > glass that I paid $8.75 a sheet for, so I've got to keep at it. (If
> > > anyone's interested, the etched side of the glass is the side the
print
> > > is viewed from; the gum is printed on the back (non-etched) side of
the
> > > glass).
> > > Katharine
> > >
> > >
> > > Katharine Thayer wrote:
> > > >
> > > > I've obtained some silane which I hope is the same silane mentioned
> > > > below (Martin Mueller's post from Feb 5). The supplier calls it
gamma
> > > > aminopropyltriethoxysilane and it's what they sent me when I asked
for
> > > > 3-aminopropyltriethoxysilane. I've seen the two names used
> > > > interchangeably and they have the same CAS number, so I'm hoping
it's
> > > > the same substance. (Sorry, my knowledge of organic nomenclature is
far
> > > > in the past so I can't tell by looking at the names why they would
be
> > > > the same thing).
> > > >
> > > > At any rate I've applied this silane, mixed 1% with acetone, to two
> > > > carefully cleaned and de-greased and alcohol-treated (thanks
Galina!)
> > > > sheets of glass, left them overnight, and printed gum on them this
> > > > morning. Some observations:
> > > >
> > > > (1) The wet gum coating didn't stick as well to the silane-treated
glass
> > > > as it does to plain glass, nor did it brush as smoothly as it would
on
> > > > plain glass; it seemed to be phobic to the silane.
> > > >
> > > > (2) The exposed and hardened gum frilled off the silane-treated
glass
> > > > exactly as it would from plain untreated glass.
> > > >
> > > > (3) An added annoyance: Dichromate stains along the edges of the
> > > > brushmarks, that simply will not clear with potassium metabisulfite
> > > > treatment.
> > > >
> > > > However, now that I have re-read Martin's post one more time, I
think I
> > > > need to try it again, because I didn't apply it exactly as he
> > > > recommends. I misremembered the directions and applied the material
> > > > with a tissue and then simply left it to evaporate, instead of
rubbing
> > > > it til it evaporated, as instructed.
> > > >
> > > > So I will try it again, following the instructions precisely, but
this
> > > > can't happen until there is another nice day, (it's raining today)
> > > > because I have to work outside with the acetone.
> > > >
> > > > Katharine Thayer
> > > >
> > > > MARTINM wrote:
> > > > >
> > > > > Another approach consists of using silane for the subbing: rub the
> > > > > (clean/degreased!) glass plate with a 1% freshly prepared acetone
> > solution
> > > > > of 3-aminopropyltriethoxysilane over one or both sides with a
tissue
> > for
> > > > > about 1 min until the solvent has evaporated. Allow the glass
plate to
> > stand
> > > > > for several hours to ensure reaction of the silane. On that layer
your
> > gum
> > > > > solution will firmly adhere.
> > > > >
> > > > > Some time ago (maybe in 2002 or 2003 - take a look at the
archives)
> > Philippe
> > > > > Monnoyer recommended incorporating silane into a gelatin solution.
It
> > may be
> > > > > a good idea to add a small amount of that above mentioned silane
> > mixture to
> > > > > your gum solution.
> > > > >
> > > > > Martin
Received on Sun Mar 6 04:54:14 2005