| 摘要 |
A process for treating a container having a normally solid, polymer surface with a sulfur-containing compound is carried out in two stages. In the first stage, a first sulfonation treatment is conducted by: (i) contacting the surface at a temperature of about 115 DEG to about 140 DEG F. with a first sulfur-containing compound; and, (ii) washing the surface with an aqueous liquid. Optionally, in the first stage, after the surface is contacted with the first sulfur-containing compound, but before it is washed with the aqueous liquid, the surface may be contacted with a first neutralizing agent. In the second stage, a second sulfonation treatment is conducted by contacting the surface with a second sulfur-containing compound, a second neutralizing agent and washing the surface with an aqueous liquid. The second sulfur-containing compound and the second neutralizing agent may be the same as or different than the first sulfur-containing compound and the optional first neutralizing agent, respectively. The second sulfonation treatment is conducted in substantially the same manner as the first sulfonation treatment. The process is conducted for such a period of time and with such concentrations of the first and second sulfur-containing compounds, the optional first neutralizing agent and the second neutralizing agent, that the container has average permeability to unleaded gasoline of not greater than about 0.021 g/hr. The surface, after the two stage process is completed, comprises about 200 to about 1500 micrograms of sulfur per square inch of the surface and it is penetrated by the sulfur-containing compound to an average depth of at least about 10 microns.
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