Process for the production of barrier layers for admixtures of polar and non-polar materials on the inner surface of hollow molded parts made of thermoplastics
AssigneeMesser Griesheim GmbH
InventorsRolf van Bonn, Manfred Eschwey
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Abstract
For purposes of producing barrier layers on the surfaces of thermoplastics, the surfaces are exposed to a treatment gas containing fluorine. The barrier layers are effective against mixtures of polar or non-polar substances such as, for instance, fuels containing methanol. In order to improve the barrier effect, the cooled-off treatment gas is left to act upon the surface, whose temperature at the beginning of exposure is kept between 60.degree. C. and 250.degree. C. [140.degree. F. and 482.degree. F]
Claims4
In a process for the production of barrier layers for admixtures of polar and non-polar substances on the inner surface of hollow molded parts made of thermoplastics, which are blown in a supporting mold and then exposed for some time to a treatment gas containing fluorine, the improvement being in that the temperature of the surface at the beginning of exposure lies between 60.degree. C. and 250.degree. C. [140.degree. F. and 482.degree. F.], and the reaction energy released during fluorination being removed by cooling the treatment gas.
Dependencies are inferred from the claim text.