Method of making polyvinylidene fluoride-thermoplastic resin laminates

Claim 3

The method according to claim 1 wherein said streams of resins are extruded through a single die to form a laminate of the shape desired and said streams are brought into intimate contact with each other at the latest point at the exit orifice of said die.

Claim 4

The method according to claim 1 or 2, wherein the temperature of the die is maintained between about 180° to 280° C.

Claim 5

The method according to claim 1 or 2, wherein said polyvinylidene fluoride is selected from homopolymers of polyvinylidene fluoride, copolymers containing at least 70% by weight of polyvinylidene fluoride, or mixtures of polyvinylidene fluoride with other polymers and said polyvinylidene fluoride resin having, at 200° C., an apparent viscosity, in poises, between the minimum and maximum values for at least two of the velocity gradients, in sec -1 , set forth below: ______________________________________ Velocity Gradient Apparent Viscosity Values sec.sup.-1 Minimum Maximum ______________________________________ 3.54 30 × 10.sup.3 200 × 10.sup.3 11.81 18 × 10.sup.3 93 × 10.sup.3 35.4 11 × 10.sup.3 47 × 10.sup.3 118 6.5 × 10.sup.3 21 × 10.sup.3 354 3.9 × 10.sup.3 10 × 10.sup.3 1181 2.3 × 10.sup.3 4.5 × 10.sup.3 ______________________________________

Claim 6

The method according to claim 1 or 2 wherein the polyalkyl methacrylate resin is polymethyl methacrylate having a viscosity, in poises, at 200° C., between the minimum and maximum values for any given viscosity gradient, in sec -1 , set forth below: ______________________________________ Velocity gradient Apparent viscosity values in poise sec.sup.-1 minimum maximum ______________________________________ 3.54 100 × 10.sup.3 500 × 10.sup.3 11.81 50 × 10.sup.3 280 × 10.sup.3 35.4 25 × 10.sup.3 150 × 10.sup.3 118 13 × 10.sup.3 80 × 10.sup.3 354 7 × 10.sup.3 50 × 10.sup.3 1181 3.5 × 10.sup.3 30 × 10.sup.3 ______________________________________