SOUFA was brushed on to copy paper, and after drying, it was ignited with an alcohol lamp.
SOUFA gives high flame resistance to cellulose, so it is easy to stop burning. However, SOUFA does burn.
As for the flame retardant mechanism, SOUFA settles on the cellulose of the copy paper and reacts to heat when heat is applied, forming a thin glass film on the cotton surface. At the same time, it combines with the carbon of cotton to form an oxygen-blocking film. It becomes a little crispy. If the mass is about the same as paper, it is thought that using more low-bodied material will have a sufficient effect. This time it is 16%, but a few percent may be enough.
Therefore, once it is burnt, it will not spread further. If it’s just a brush coat, you won’t see much effect on the texture.
However, if too much is applied, it may become hard. This is because the boric acid has a property of slightly hardening cellulose.