Re: Adhesion

MARTINM wrote:

Katharine Thayer wrote:
>
  Is silane something that a person can get a small amount of,
> > and has anyone actually used this to print gum on glass or other hard
> > surfaces?
>
> Yes, I expect "silane" to work in such a case. Note there is a large
> variety of different kinds of "silanes". Take a look at:
> http://www.powerchemical.net/index.htm
> You may pay special attention on "silane coupling agents".
>
> "Silane coupling agents belong to a class of organosilane compounds having
> at least two reactive groups of different types bonded to the silicon atom
> in a molecule. One of the reactive groups of different types (ex. methoxy,
> ethoxy and silanolic hydroxy groups) is reactive with various inorganic
> materials such as glass, metals, silica sand and the like to form a chemical
> bond with the surface of the inorganic material while the other of the
> reactive groups (ex, vinyl, epoxy, methacryl, amino and mercapto groups) is
> reactive with various kinds of organic materials or synthetic resins to form
> a chemical bond.
> As a result of possessing these two types of reactive groups, silane
> coupling agents are capable of providing chemical bonding between an organic
> material and an inorganic
> material."(http://www.micchem.com/products/SilaneCouplingAgents.htm)
>
> I am not sure whether the 3-aminopropyltriethoxysilane is the best silane to
> use when dealing with gum arabic solutions. 3-aminopropyltriethoxysilane
> used to be the standard agent to promote gelatin (silver-halide emulsions)
> adhesion on glass.
> Prior to the introduction of silanes, glass subbing had also been done with
> sodium/potassium silicate (water glass). By the way, temperature was said to
> play a crucial part when coating gelatin on glass. 50°C was considered about
> the upper limit.
>

Sorry, I've been laid up for a few days and am still not super great,
but trying to get back to work. Going out the back door toward the
studio Monday morning, I slipped on ice and came down hard on my back on
the steps, bending and cracking a rib in two places. So I'm a little
behind on the list traffic again. This has not been the best month of my
life so far.

Thanks for the further information above, Martin. If this isn't the
right silane, what would be, I wonder. It sounds like some experimenting
may be required and I just can't be doing any more experimenting between
now and March 1. So I guess I'll go with my present plan unless someone
can tell me they've actually used a silane with gum and it's worked.

My first question would be: how would the silane know to adhere the gum
to the glass only in the exposed areas and not in the unexposed areas?
Katharine
Received on Thu Feb 17 10:12:39 2005