| 摘要 |
<p>This invention provides metal-thermoplastic-metal laminates and a process for preparing same, which have in combination critical service properties of high heat distortion temperature, low coefficient of linear thermal expansion, low inelastic ratio and lightness in weight. The core layer is selected from the group consisting of partly crystalline polymers and polyesters having a crystalline melting point greater than 130.degree.C. and has a minimum thickness of 0.0483 cm. Each metal layer has a melting point greater than the crystalline melting point of the core and a minimum thickness of 0.00127 cm. The thickness ratio of the sum of the metal layers to the core layer thickness is described by the region of numerical overlap of TR(YSm/TSc) wherein TR is the thickness ratio of the sum of the metal layer thicknesses to the thermoplastic core layer thickness; YSm is the thicknessweight-average tensile yield strength of the two metal layers at an offset of 5% elongation; and TSc is the tensile strength of the thermoplastic core layer. This is determined from the areas defined by the relationships of TR(YSm/TSc) to the inelastic ratio of the laminate as measured in flexure at 5% strain in the outer metal layers at the point of maximum deflection (TR?); the coefficient of linear thermal expansion of the laminate (CLTE?); and a normalized heat distortion temperature variable (HDT? - HDTC)/(Tm - HDTc). The lower boundary of these areas is defined by the equation of a straight line y = mx + b in which y is the y-axis parameters of IR?, CLTE?, and (HDT? - HDTc)/(Tmc - HDTc), x is the x-axis parameter of TR(YSm/TSc), m is the slope of the straight line, and b is the intercept on the y-axis. The laminates of this invention may be used in construction applications such as outer and inner building panels, appliance panels, and transportation vehicle body panels for example, automobiles, boats, airplanes and the like.</p> |
