Re: Glyoxal?

Katharine, Ryuji and all

yes it helps Katharine . The first item in my catalog as the same CAS number
as you mention and your right again about the concentration it's 40%
(38-42%) here also. The formula for this one is (Glyoxal, 40% in water)
C2H2O2 there are also these in my catalog:
Glyoxal, Dihydrate (trimer) C6H606*2H2O CAS 4405-13-4
Glyoxal bis (sodium hydrogen sulfite) Adduct, Hydrate C2H4Na2O8S2*xH2O CAS
517-21-5
Glyoxal-bis (2-hydroxyanil) C14H12N2O2 CAS 1149-16-2

I've mistaken 2 Glyoxylic acid for Glyoxal when I said 5 or 6, I hope you
wont hold this against me... I was looking at the formula (Glyoxylic acid ,
monohydrate) C2H2O3*H2O and it seem so close to the first version (Glyoxal,
40%) that I thought it could be also Glyoxal but it's probably not the case.

While I'm at it, I read it's yellow in color, does this color stays in the
gelatine when sizing?

Thanks
Yves

----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Wednesday, January 11, 2006 9:06 PM
Subject: Re: Glyoxal?

> Hi Yves,
> Mine from Photographers' Formulary says simply "Glyoxal" and there
> is a CAS Mixture Number 107-22-2, if that's any help. I am pretty
> sure this is the standard 40% concentration that most people use for
> our purposes but suddenly I'm not sure I know how I know that, since
> there's nothing on the bottle that gives the percent solution. At
> any rate it works well for me at 3 mls of the solution per 200 ml
> gelatin solution, which is kind of a standard recommendation, usually
> expressed as 15 ml per liter of gelatin solution. Or expressing it as
> grams to grams, hardener to gelatin, as I think Ryuji was
> recommending, I guess I use 1.2 (g?) of glyoxal (3 ml * .40) per 7
> grams of gelatin.
> Katharine
>
>
> On Jan 11, 2006, at 4:43 AM, Yves Gauvreau wrote:
>
> > Hi everyone,
> >
> > I know some of you use glyoxal when sizing their paper and my
> > question is
> > what is the full name of this product or better the chemical
> > formula???. I
> > ask because in my catalog I have about 5 or 6 chemicals that could
> > qualify
> > as glyoxal.
> >
> > Thanks
> > Yves
> >
> >
Received on Thu Jan 12 00:36:00 2006