| 摘要 |
1,052,761. Moulding hollow articles; laminates. SOLVAY & CIE. June 19, 1964 [June 19, 1963; Feb. 6, 1964; May 12, 1964], No. 25471/64. Headings B5A and B5N. [Also in Divisions C3 and F2] Pipes, tubes, phials, drums, collapsible tubes and like hollow articles for packaging or conducting materials comprise two extruded concentric outer and inner layers formed respectively of (a) comparatively rigid but permeable materials such as vinyl halide polymers or copolymers or polyolefins, and (b) copolymers containing 65-95% vinylidene chloride, which are impermeable. The articles may be made by (a) extruding the layers through concentric circular apertures, followed by blow moulding or other working up if necessary, (b) extruding the impermeable layer as a tube and extrusion coating its exterior surface with the rigid material, or (c) placing one preformed tube within the other, which fits it closely or has been previously expanded, and heating to fuse them together. Material for the outer layer may be P.V.C., P.V.C.-copolymers, polythene, polypropylene and ethylene copolymers. The inner layer may comprise copolymers with vinylidene chloride of vinylchloride, acrylonitrile or styrene, plasticized with esters or epoxyesters of mono- or poly-carboxylic acids, of which many examples given include " epoxide tallates ", made by epoxidizing the ester reaction products of tall oil and an alcohol, e.g. allyl tallate. |
