Polyvinylidene fluoride-thermoplastic resin laminates and method

Claim 2

A unitary laminate comprising at least one polyvinylidene fluoride resin layer, a layer of a thermoplastic resin other than a polyvinylidene fluoride, and a layer of a polyalkyl methacrylate intermediate and firmly adhered to said polyvinylidene fluoride and thermoplastic resin layers; said layers being blended at their interfaces only.

Claim 3

The laminate of claim 1 wherein the polyvinylidene fluoride used to form said polyvinylidene fluoride layer has, at 200° C., an apparent viscosity, in poises, between the minimum and maximum values for at least two of the viscosity gradients, in sec -1 , set forth below: ______________________________________ Viscosity gradient Apparent viscosity values in poise 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 4

The laminate of claim 1 or 2 wherein the polyalkyl methacrylate is a polymethyl methacrylate.

Claim 5

The laminate of claim 3 wherein the polymethyl methacrylate has 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 ______________________________________

Claim 6

The laminate of claim 1 or 2 wherein the polyvinylidene fluoride resin 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.

Claim 7

The laminate of claim 5 wherein the polyalkyl methacrylate is a polymethyl methacrylate and the thermoplastic resin is selected from vinyl or vinylidene polymers containing chlorine, styrene polymers, polycarbonates, polyurethanes, copolymers of styrene/acrylonitrile/grafted acrylic elastomer, or copolymers of acrylonitrile/butadiene/styrene.

Claim 8

A unitary laminate consisting essentially of at least one exterior layer of a polyvinylidene fluoride resin layer, a layer of a thermoplastic resin other than a polyvinylidene fluoride, and a layer of a polyalkyl methacrylate intermediate and firmly adhered to said polyvinylidene fluoride and thermoplastic resin layers, said laminate formed by coextrusion of the three layers.

Claim 9

A unitary laminate consisting essentially of at least one exterior layer of a polyvinylidene fluoride resin layer, a layer of a thermoplastic resin other than a polyvinylidene fluoride, and a layer of a polyalkyl methacrylate intermediate and firmly adhered to said polyvinylidene fluoride and thermoplastic resin layers, said laminate formed by coextrusion of the three layers.