From: Keith Gerling (keithgerling@att.net)
Date: 09/03/02-11:38:21 AM Z
Thank you for this help. I thought that the surface was very clean, but it
was certainly not hydrophilic.
One item that causes me some concern: in most instances, using paper as a
substrate, I notice a very evident fogging effect when the emulsion is not
exposed and developed within 8 hours.
-----Original Message-----
From: Monnoyer Philippe [mailto:monnoyer@imec.be]
Sent: Tuesday, September 03, 2002 11:26 AM
To: alt-photo-process-l@sask.usask.ca
Subject: RE: silane
It is true that I never tried z-6040 with gum.
Either your glass is not cleaned chemically (soap, caustic soda solution,
rinse, distilled wated rinse) or z-6040 epoxy group does not attach to the
gum. It that latter case I would use a subbing rather then an addition of
z-6040.
The subbing may be 1% gelatin solution with hardening agent like 1g of
chrome alum (or glyoxal) per 100ml. Glyoxal should work faster.
After cleaing, your glass surface has to be hydrophilic, meaning that if you
pour water on the surface, it has to make a film and does not bead up. Use
gloves all the time.
If you want more info, dive into old patents on photographic emulsions
(check AGFA)
Second point: an emulsion takes some minutes to set. From that point you can
handle it or move it. BUT it may take more than 24hrs to be dry, and this is
normal. Nothing special. Do not warm the drying air above the melting T of
the set gel on the plate (around 26°C) or your coating will be a disaster.
Yours,
Philippe
----------------------------------------
Philippe Monnoyer, Ph.D.
Silicon Process and Device Technology
IMEC vzw
Kapeldreef, 75
B-3001 Leuven
Phone: +32 (0)16 28 17 35
Fax: +32 (0)16 28 12 14
http://www.imec.be
----------------------------------------
|-----Original Message-----
|From: Keith Gerling [mailto:keithgerling@att.net]
|Sent: Tuesday, September 03, 2002 16:55
|To: alt-photo-process-l@skyway.usask.ca
|Subject: RE: silane
|
|
|It wouldn't work for me, but then I was working from what
|little information
|I could scrounge on the web, and with the advice of some people that,
|admittedly, are not experts on using coupling agents. Perhaps
|you could
|point me to some better information?
|
|When I added the opoxysilane to my gum emulsion, the emulsion,
|A) tended to
|bead up on the glass or metal surface and no amount of
|brushing would smooth
|it out (even when I added various surficants), and B) took
|many hours to
|dry.
|
|
|-----Original Message-----
|From: Monnoyer Philippe [mailto:monnoyer@imec.be]
|Sent: Tuesday, September 03, 2002 3:12 AM
|To: alt-photo-process-l@sask.usask.ca
|Subject: RE: silane
|
|
|Hi,
|
|I just want to insist on the fact that the DOW Corning z-6040
|epoxysilane is
|OK to have your emulsion stick to a clean glass surface. This
|is a fully
|transparent clean product. One part of that molecule sticks to
|the glass.
|The other part reacts with the gelatin and is attached
|chemicaly to it. The
|result is a strong bound to the glass surface.
|(Ref. in archives :Subject: RE: chrome alum and plate coating
|Date: Thu, 02
|May 2002 14:33:52 +0200 )
|
|Philippe
|
|
||
|
|
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