| 摘要 |
The invention relates to a multilayer tube comprising (in the order from the inside to the outside of the tube), layers arranged one on top of the other: an optional layer L1 comprising at least one fluorinated polymer, preferably a PVDF; a layer L2 comprising at least one functionalized PVDF, obtained by radiation-grafting of at least one unsaturated polar monomer onto a PVDF; an optionally layer L3 of an adhesion binder; a layer L4 comprising at least one polyolefin optionally mixed with at least one functionalized polyolefin; an optional barrier layer L5; an optional layer L6 comprising at least one polyolefin, optionally in a mixture with at least one functionalized polyolefin; characterized in that the PVDF onto which the unsaturated polar monomer is grafted is a VDF copolymer those weight content is at least 50%, preferably at least 75%, and at least one monomer copolymerizable with the VDF, having the following characteristics: a crystallization temperature Tc (measured by DSC as per the ISO Standard 11357-3) ranging from 50 to 120° C., preferably 85 to 110° C.; a yield strength &sgr;Y ranging from 10 to 40 MPa, preferably 10 to 30 MPa; and a melt viscosity &eegr; (measured with a capillary rheometer at 230° C. at 100 s−1) ranging from 100 to 1500 Pa·s, preferably 400 to 1200 Pa·s.” |
