| abstract |
Cellulose material having improved resistance to thermal deterioration and having particular application as insulation material for electrical apparatus. The cellulose material is treated with an aqueous dispersion of a liquid, uncured, crosslinkable thermosetting resin, such as an epoxy resin, and a water soluble, nitrogen-containing compound. During curing of the resin, the cellulose molecules are believed to enter into the crosslinking reaction to provide a treated cellulosic product capable of withstanding the deteriorating action of heat over extended periods of time. A protein material, such as casein or isolated soy protein, can be added to the treating liquid and the protein not only contributes additional nitrogen groups to the treating media to further increase the thermal stability of the cellulose, but also acts as a film former. The thermal stability of the cellulose material can be further improved by the addition of an organic amine, such as melamine, to the treating liquid. |