Patent ID: 6656553
Filing Date: 2003-12-02
Classification: B29C,B32B,F16L,Y10T

Abstract:
A hose for fuel having a laminated structure, comprising:an inner layer made of an ethylene/tetrafluoroethylene copolymer and an outer layer made of a polyamide resin, wherein the inner layer adheres to the polyamide resin of the outer layer, and the outer layer is made of polyamide 12(a) that satisfies formula (1), or a mixture of polyamide 12(a) that satisfies formula (1) and polyamide 12(b) that satisfies formula (2), wherein polyamides 12(a) and 12(b) satisfy formula (3) and are polyamide resins showing an adhesive strength of at least 20 N/cm to the inner layer: [COOH]+[NH2]&gE;2Ã—102/(17.8&eegr;r(a)âˆ’19.1)â€ƒâ€ƒ(1) [COOH]+[NH2]<2Ã—102/(17.8&eegr;r(b)âˆ’19.1)â€ƒâ€ƒ(2) &eegr;r(b)âˆ’&eegr;r(a)&gE;0.3â€ƒâ€ƒ(3) wherein [COOH] is the equivalent concentration of polyamide terminal carboxyl groups, [NH2] is the equivalent concentration of polyamide terminal amino groups, and &eegr;r(a) and &eegr;r(b) are the relative viscosities of polyamides 12(a) and 12(b), respectively.