The present invention is directed to polyamides that are crosslinkable in the presence of water having desirable properties including long open time, good adhesion and cold flexibility. Notably, the polyamides of the present invention are suitable for structural and semi-structural bonding applications utilizing a hot melt process, roll coater or bead extrusion process.

Electrical insulating paper according to an embodiment of the present invention is used while being immersed in electrical insulating oil, and includes a paper base material mainly containing cellulose, an adsorption layer formed on an entire surface of the paper base material by adsorption, and a moisture barrier layer formed by being chemically bonded to the adsorption layer. The moisture barrier layer includes an amphipathic molecule containing both a hydrophobic hydrocarbon group and a hydrophilic functional group in one molecule. The amphipathic molecule is chemically bonded to the adsorption layer via the hydrophilic functional group. The hydrophobic hydrocarbon group covers the surface of the paper base material.

The invention relates to a packaging board comprising a fibrous base and one or more polymer coating layers on one or both sides of the fibrous base. According to the invention the fibrous base contains the combination of an alkyl ketene dimer size, stearic acid anhydride, a wet-strength size and an aluminium compound, which give the board resistance to aggressive liquids as well as thermal treatment, particularly an improved resistance to raw edge penetration in such circumstances. The invention further relates to containers and packages made of the board, for instance disposable drinking cups, dairy product cartons and auto-clave packages, as well as use of the board for such purposes.