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US 4,424,254 AGranted
Metal-thermoplastic-metal laminates
AssigneeMonsanto Company
InventorsRoss M. Hedrick, James C. Woodbrey, James D. Gabbert, Floyd B. Erickson
Life of this patent
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Abstract
This invention relates to construction panels comprising metal-thermoplastic-metal laminates and a process for preparing same, said laminates possessing in combination critical service properties of low coefficient of linear thermal expansion, low inelastic ratio, and excellent flexural stiffness.
Claims18
A metal-thermoplastic-metal laminate having in combination:
- an inelastic ratio less than about 93%;
- a coefficient of linear thermal expansion less than about 63.times.10.sup.-6 .degree. C..sup.-1 ;
- a flexural stiffness of at least about 52.53.times.10.sup.3 N/m;
- and
- a maximum weight of no more than about 9.76 kg/m.sup.2 ;
- said laminate comprising:
- a thermoplastic core layer, said core having a minimum thickness of about 0.0483 cm;
- and
- a metal layer laminated on each side of the thermoplastic core layer, each metal layer having a minimum thickness of about 0.00127 cm;
- provided that aluminum is not the metal layer on both sides of the laminate when the thermoplastic core layer is high density polyethylene and further provided that when polypropylene is the thermoplastic core and aluminum is the metal layer laminated on each side of the core, the laminate has a maximum weight of about 5.37 kg/m.sup.2 ;
- wherein the thickness ratio of the sum of the metal layer-thicknesses to the thermoplastic core layer thickness is described by the region of numerical overlap of the parameter TR(YS.sub.m /TS.sub.c) as determined from the areas defined by the relationships of TR(YS.sub.m /TS.sub.c) to IR.sub.l and CLTE.sub.l, the lower boundary of said areas being defined by the equation of a straight line
- y=mx+b
- in which y is the y-axis parameters of IR.sub.l and CLTE.sub.l, x is the x-axis parameter of TR(YS.sub.m /TS.sub.c), m is the slope of the straight line, and b is the intercept on the y-axis with the proviso that:
- when y is IR.sub.l, m is 108 and b is zero (0) for values of x from zero (0) to 0.65, and m is zero (0) and b is 70 for values of x greater than 0.65;
- and
- when y is CLTE.sub.l, m is -3.6.times.10.sup.-4 and b is 45.times.10.sup.-6 for values of x from zero (0) to 0.1 and m is zero (0) and b is 9.times.10.sup.-6 for values of x greater than 0.1;
- and the upper boundary of said areas being defined by the equation of a straight line as defined hereinabove, with the proviso that:
- when y is IR.sub.l, m is 280 and b is 30 for values of x from zero (0) to 0.25, and m is zero (0) and b is 100 for values of x greater than 0.25;
- and when y is CLTE.sub.l, m is -2.88.times.10.sup.-3 and b is 216.times.10.sup.-6 for values of x from zero (0) to 0.05, m is -1.29.times.10.sup.-4 and b is 78.5.times.10.sup.-6 for values of x from 0.05 to 0.26 and m is zero (0) and b is 45.times.10.sup.-6 for values of x greater than 0.26;
- wherein:
- IR.sub.l is the inelastic ratio of the laminate as measured in flexure at 5% strain in the outer metal layers at the point of maximum deflection;
- CLTE.sub.l is the coefficient of linear thermal expansion of the laminate;
- TR is the thickness ratio of the sum of the metal layer-thicknesses to the thermoplastic core layer thickness;
- YS.sub.m is the thickness-weight-average tensile yield strength of the two metal layers at an offset of 5% elongation;
- and
- TS.sub.c is the tensile strength of the thermoplastic core layer.
23 more elements
A metal-thermoplastic-metal laminate having in combination:
- an inelastic ratio less than about 93%;
- a coefficient of linear thermal expansion less than about 63.times.10.sup.-6 .degree. C..sup.-1 ;
- a flexural stiffness of at least about 52.53.times.10.sup.3 N/m;
- and
- a maximum weight of no more than about 9.76 kg/m.sup.2 ;
- said laminate comprising:
- a thermoplastic core layer provided that said thermoplastic core is not selected from polyamides and polyesters;
- and
- a metal layer laminated on each side of the thermoplastic core layer, each metal layer having a minimum thickness of about 0.00127 cm;
- provided that aluminum is not the metal layer on both sides of the laminate when the thermoplastic core layer is high density polyethylene and further provided that when polypropylene is the thermoplastic core and aluminum is the metal layer laminated on each side of the core, the laminate has a maximum weight of about 5.37 kg/m.sup.2 ;
- wherein the thickness ratio of the sum of the metal layer-thickness to the thermoplastic core layer thickness is described by the region of numerical overlap of the parameter TR(YS.sub.m /YS.sub.c) as determined from the areas defined by the relationships of TR(YS.sub.m /TS.sub.c) to IR.sub.l and CLTE.sub.l, the lower boundary of said areas being defined by the equation of a straight line
- y=mx+b
- in which y is the y-axis parameters of IR.sub.l and CLTE.sub.l, x is the x-axis parameter of TR(YS.sub.m /TS.sub.c), m is the slope of the straight line, and b is the intercept on the y-axis, with the proviso that:
- when y is IR.sub.l, m is 108 and b is zero (0) for values of x from zero (0) to 0.65, and m is zero (0) and b is 70 for values of x greater than 0.65;
- and
- when y is CLTE.sub.l, m is -3.6.times.10.sup.-4 and b is 45.times.10.sup.-6 for values of x from zero (0) to 0.1, and m is zero (0) and b is 9.times.10.sup.-6 for values of x greater than 0.1;
- and the upper boundary of said areas being defined by the equation of a straight line as defined hereinabove, with the proviso that:
- when y is IR.sub.l, m is 280 and b is 30 for values of x from zero (0) to 0.25, and m is zero (0) and b is 100 for values of x greater than 0.25;
- and when y is CLTE.sub.l, m is 2.88.times.10.sup.-3 and b is 216.times.10.sup.-3 and b is 216.times.10.sup.-6 for values of x from zero (0) to 0.05, m is -1.29.times.10.sup.-4 and b is 78.5.times.10.sup.-6 for values of x from 0.05 to 0.26, and m is zero (0) and b is 45.times.10.sup.-6 for values of x greater than 0.26;
- wherein:
- IR.sub.l is the inelastic ratio of the laminate as measured in flexure at 5% strain in the outer metal layers at the point of maximum deflection;
- CLTE.sub.l is the coefficient of linear thermal expansion of the laminate;
- TR is the thickness ratio of the sum of the metal layer-thicknesses to the thermoplastic core layer thickness;
- YS.sub.m is the thickness-weight-average tensile yield strength of the two metal layers at an offset of 5% elongation;
- and
- TS.sub.c is the tensile strength of the thermoplastic core layer.
23 more elements
Dependencies are inferred from the claim text.