Koninklijke Emballage Industrie Van Leer B.v.

Roger A Shefford

The present invention relates to an enclosure member consisting essentially of solid, non-aromatic polymers that have a linear carbon to carbon backbone structure and have a plurality of free hydrogen atoms attached to the carbon atoms with a permeability to wet and dry solvents and fuels of less than 1/50, of the permeability of untreated enclosure members having a thickness of 1 mm, a portion of the hydrogen atoms of the surfaces of said member having been replaced by sulphonic acid or sulphonate groups and being coated with a cured thin layer of a mixture of a resin made by the reaction of urea and formaldehyde, respectively of melamine and formaldehyde, with furfuryl alcohol, and an oligomer consisting of a polymer of furfuryl alcohol and formaldehyde.

Enclosure member consisting essentially of solid, non-aromatic polymers

The present application relates to enclosure members consisting essentially of solid, non-aromatic polymers that have a linear carbon to carbon backbone structure and having a plurality of free hydrogen atoms attached to the carbon atoms with a permeability to wet solvents and fuels of less than 1/50, optionally less than 1/200 of the permeability of untreated enclosure members having a thickness of 1 mm. Said low permeability is due to the presence of a coating on at least the inner surface of said enclosure members, having a portion of the hydrogen atoms replaced by sulphonic acid or sulphonate groups, consisting of a cured thin layer (of at least 2 .mu.m) of condensation products of formaldehyde and melamine of formaldehyde and urea. Evidently the application relates also to a method of preparing said enclosure members.

Enclosure member substantially impermeable to the transmission of

The present application relates to enclosure members consisting essentially of solid, non-aromatic polymers that have a linear carbon to carbon backbone structure and having a plurality of free hydrogen atoms attached to the carbon atoms with a permeability to wet solvents and fuels of less than 1/7, optionally less than 1/40 of the permeability of untreated enclosure members having a thickness of 1 mm. Said low permeability is due to the presence of a layer of an iron phenanthroline complex on at least the inner surface of said enclosure members, having a portion of the hydrogen atoms replaced by sulfonic acid or sulfonate groups.

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Aldershot, United Kingdom

Roger A Shefford