Process for the manufacture of polyvinylidene fluoride - incompatible polymer laminates
AssigneeChimiques Ugine Kuhlmann
InventorAlbert Strassel
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Abstract
The process of forming a laminate by molding, preferably either by compression or injection molding, a polymer which is incompatible with PVF.sub.2 onto the surface of a preformed laminate sheet of a PVF.sub.2 and a polyalkyl methacrylate, with the preformed laminate have been previously obtained by the coextrusion of the PVF.sub.2 and polyalkyl methacrylate.
Claims5
The process of making a molded article having at least one outer surface of a polyvinylidene fluoride comprising first placing a preformed polyvinylidene fluoride laminate into a compression or injection mold so as to have a polyvinylidene fluoride layer adjacent a wall of the mold, introducing a moldable polymer that is incompatible in terms of adhesion to polyvinylidene fluoride but adherent to polymethyl methacrylate to the mold, and molding at a pressure and temperature sufficient and for a time sufficient to form a shaped laminate;
- said preformed polyvinylidene laminate having a thickness no greater than about 800 microns and consisting of a polyvinylidene fluoride layer and a polymethyl methacrylate layer and being formed by coextrusion with the polyvinylidene fluoride used to form the laminate having an apparent viscosity, in poises at 200.degree. C., between the minimum and maximum values for at least two of the viscosity gradients set forth below:
- ______________________________________ Values of Apparent Viscosities Velocity Gradient In Poise Sec-1 Minimum Maximum ______________________________________ 3.54 30 .times. 10.sup.3 200 .times. 10.sup.3 11.81 18 .times. 10.sup.3 93 .times. 10.sup.3 35.4 11 .times. 10.sup.3 47 .times. 10.sup.3 118 6.5 .times. 10.sup.3 21 .times. 10.sup.3 354 3.9 .times. 10.sup.3 10 .times. 10.sup.3 1,181 2.3 .times. 10.sup.3 4.5 .times. 10.sup.3 ______________________________________
- and the polymethyl methacrylate used to form the laminate having a viscosity, in poises at 200.degree. C., between the minimum and maximum values for any given viscosity gradient set forth below:
- ______________________________________ Values of Apparent Viscosities Velocity Gradient in Poise Sec-1 Minimum Maximum ______________________________________ 3.54 100 .times. 10.sup.3 500 .times. 10.sup.3 11.81 50 .times. 10.sup.3 280 .times. 10.sup.3 35.4 25 .times. 10.sup.3 150 .times. 10.sup.3 118 13 .times. 10.sup.3 80 .times. 10.sup.3 354 7 .times. 10.sup.3 50 .times. 10.sup.3 1,181 3.5 .times. 10.sup.3 30 .times. 10.sup.3 ______________________________________
The process of making a molded article having at least one outer surface of a polyvinylidene fluoride comprising first placing a preformed polyvinylidene fluoride laminate;
- said laminate consisting of a polyvinylidene fluoride layer and a polyalkyl methacrylate layer and being formed by coextrusion, into a mold so as to have the polyvinylidene fluoride layer adjacent a wall of the mold, introducing into the mold a moldable polymer that is incompatible in terms of adhesion to polyvinylidene fluoride but adherent to said polyalkyl methacrylate and molding at a pressure and temperature sufficient and for a time sufficient to form a shaped laminate.
Dependencies are inferred from the claim text.