Abstract: A strategy for decreasing hydrocarbon emissions from a plastic fuel tank assembly having a multilayer plastic fuel tank (10) and at least one overmolded fuel tank attachment (100). The strategy consists of two basic components. First, the swelling properties of the overmolded outerlayer (116) of the fuel tank attachments 100 are exploited to close possible leakage paths between the barrier resistant core (101) and the overmolded outerlayer (116) of the fuel tank attachment (100). Second, the barrier properties of the barrier resistant core (101) of the fuel tank attachments (100) are exploited to increase the length of the diffusion path of hydrocarbon molecules out of the multilayer plastic fuel tank assembly.

Abstract: A fuel tank vapor control apparatus controls the flow of liquid and vapor fuel through an aperture in a fuel tank (16). The fuel tank vapor control apparatus includes a vent housing (12) mounted in the aperture (34) and formed to include a vent inlet (13) and a vent outlet (36), the vent housing (12) defining a vent path for communicating vapor fuel from the fuel tank between the vent inlet and the vent outlet. The apparatus also includes a valve (48) movable in the vent housing between a blocking position for blocking flow of liquid and vapor fuel from the fuel tank between the vent inlet and the vent outlet along the vent path and a venting position allowing flow of vapor fuel between the fuel tank and the vent outlet along the vent path. A labyrinthine member (140) is also included, being disposed between the fuel tank and the vent path for discriminating fuel vapor from liquid fuel so as to block liquid fuel from the vent path.

Abstract: A multi-layer molded polymer composition comprising a polyolefin layer and a immiscible polymer layer adjacent the polyolefin layer. The immiscible polymer layer is selected from a polymer that is normally immiscible for the polyolefin layer. A compatibilizer is blended into either the polyolefin layer or the immiscible polymer layer or optionally into both layers. The compatibilizer has a polyolefin backbone that is miscible in the polyolefin layer and one or more functional polymer grafts attached to the compatibilizer polyolefin backbone. The functional polymer grafts are miscible in the immiscible polymer layer whereby the compatibilizer bonds with both the polyolefin layer and the immiscible polymer layer.

Abstract: A process for treating a container comprised of a normally solid, polymer surface with a sulfur-containing compound is carried out by contacting the surface at a temperature of about 120.degree. to about 140.degree. F. with a sulfur-containing compound. Subsequently, the surface is contacted with a neutralizing agent. The process is conducted for a such a period of time and with such concentrations of the sulfur-containing compound and the neutralizing agent that the container has average permeability to unleaded gasoline having octane number of 93 of not greater than about 0.021 g/hr.The surface, after the treatment, comprises about 700 to about 1800 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 15 microns.

Abstract: 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.degree. to about 140.degree. 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.