Transparent polyamide and multi-ply barrier films containing same
AssigneeEMS-Inventa AG
InventorsUlrich Presenz, Manfred Hewel
Life of this patent
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Abstract
The invention relates to a barrier layer resisting the transmission of oxygen for multi-layer barrier film characterized in that it is made of a transparent copolyamide comprising three components. The first component is hexamethylenediamine and adipic acid. The second component is hexamethylenediamine and azelaic acid, hexamethylenediamine and sebacic acid, and mixtures thereof. The third component is hexamethylene-diamine and isophthalic acid, hexamethylenediamine and terephthalic acid, and mixtures thereof. The total of all components is 100 mol %, and the ratio of the barrier effects in the barrier layer with respect to carbon dioxide and oxygen is at least 3:1.
Claims11
In a multi-ply film including a barrier layer, the improvement comprising said barrier layer consisting of a transparent polyamide derived from a composition consisting of
- (a) a first component comprising hexamethylenediamine/adipic acid and present from about 15 to 75 mol %;
- (b) a second component selected from the group consisting of hexamethylenediamine/azelic acid, hexamethylene/sebacic acid, and mixtures thereof and present from about 15 to 65 mol %;
- and
- (c) a third component selected from the group consisting of hexamethylenediamine/isophthalic acid, hexamethylenediamine/terephthalic acid, and mixtures thereof, and present from about 10 to 70 mol %,
- said first, second and third components totalling 100 mol %, said copolymer exhibiting barrier values having a ratio of at least 3:1 with respect to carbon dioxide and oxygen, and said copolyamide having a relative viscosity between about 1.75 and 2.50 measured as a 0.5% solution in m-cresol at 23.degree. C.
A transparent copolyamide barrier layer in a multi-ply film, said barrier layer having been derived from a composition consisting of the following components:
- (a) a first component comprising hexamethylenediamine/adipic acid and present from about 15 to 75 mol %;
- (b) a second component selected from the group consisting of hexamethylenediamine/azelaic acid, hexamethylenediamine/sebacic acid, and mixtures thereof, and present from about 15 to 65 mol %;
- and
- (c) a third component selected from the group consisting of hexamethylenediamine/isophthalic acid, hexamethylenediamine/terephthalic acid, and mixtures thereof, and present from about 10 to 70 mol %,
- said first, second, and third components totaling 100 mol %, and said barrier layer exhibiting barrier properties having a ratio of at least 3:1 with respect to carbon dioxide and oxygen.
Dependencies are inferred from the claim text.