Pressure sensitive adhesive coated polymeric film laminates

Claim 1

The two ply laminate of claim 1, wherein the exposed surface of said lower lamina tacky, pressure sensitive adhesive film, is adhered to a silicone coated release sheet.

Claim 4

A method of preparing a two ply laminate wherein the upper lamina comprises: (I) a friable polymeric film which is derived from the group consisting of (A) homopolymers of the C1-C4 lower alkyl acrylate and methacrylate esters as well as copolymers of the latter C1-C4 lower alkyl acrylate and methacrylate esters with one another and with minor amounts of at least one vinyl comonomer selected from the group consisting of vinyl acetate, vinyl chloride, styrene, acrylonitrile and the C1-C4 lower alkyl esters of maleic and fumaric acids; (B) polyvinyl chloride and copolymers of vinyl chloride with at least one vinyl comonomer selected from the group consisting of vinyl acetate and the C1-C4 lower alkyl esters of maleic and fumaric acids; and, (C) ethers and esters of cellulose; and the lower lamina, which is bonded to and in intimate face-to-face contact with said upper lamina, comprises: (II) a film of a tacky, pressure sensitive adhesive selected from the group consisting of: (A) natural rubber; (B) synthetic rubbers selected from the group consisting of Styrene-butadiene copolymers, polyisobutylene, butadiene-acrylonitrile copolymers, polychloroprene and polyisoprene; and (C) elastomeric copolymers containing at least 50 percent, by weight, of at least one C4-C12 alkyl ester of an acid selected from the group consisting of acrylic and methacrylic acids together with a hardening comonomer selected from the group consisting of vinyl acetate, styrene, methyl methacrylate, ethyl methacrylate and vinyl chloride; and, (D) elastomeric polymers of alkyl vinyl ethers selected from the group consisting of polymethyl vinyl ether and polyethyl vinyl ether; the said polymeric film having a tensile strength, at its breaking point, which is less than the strength of the adhesive bond formed between the said pressure sensitive adhesive film and any solid substrate to which said pressure sensitive adhesive film may be adhered, thereby resulting in the mechanical rupture of said upper lamina when an attempt is made to remove the laminate from said solid substrate; said method comprising the steps of: (1) casting a solution of said polymeric film, in an organic solvent, onto a casting sheet substrate having a nonabsorbent surface, a smooth finish and a low degree of adhesion for the resulting polymer film; (2) drying the polymeric film obtained in step (1) so as to remove the organic solvent therefrom; (3) casting a solution of said pressure sensitive adhesive, in an organic solvent, onto a silicone coated release sheet; (4) drying the pressure sensitive adhesive film obtained in step (3) so as to remove the organic solvent therefrom; (5) adhering the dry polymer film resulting from steps (1) and (2) onto the exposed surface of the pressure sensitive adhesive film resulting from steps (3) and (4) so that the polymer film and the pressure sensitive adhesive film are bonded in intimate, face-to-face contact with one another; (6) removing the casting sheet from the surface of the polymer film; and (7) removing the silicone coated release sheet from the surface of the pressure sensitive adhesive film, thereby resulting in the two ply laminate which may then be adhered to any solid substrate via the exposed surface of the pressure sensitive adhesive film forming lower lamina of said laminate.

Claim 5

A method of preparing a two-ply laminate wherein the upper lamina comprises: (I) a friable polymeric film derived from a polymer selected from the group consisting of (A) homopolymers of the C1-C4 lower alkyl acrylate and methacrylate esters as well as copolymers of the latter C1-C4 lower alkyl acrylate and methacrylate esters with one another and with minor amounts of at least one vinyl comonomer selected from the group consisting of vinyl acetate, vinyl chloride, styrene, acrylonitrile and the C1-C4 lower alkyl esters of maleic and fumaric acids; and, the lower lamina which is bonded to and in intimate face-to-face contact with said upper lamina, comprises: (II) a film of a tacky, pressure sensitive adhesive comprising a copolymer containing at least 50 percent, by weight, of at least one C4-C12 alkyl ester of an acid selected from the group consisting of acrylic and methacrylic acid together with a hardening comonomer selected from the group consisting of vinyl acetate, styrene, methyl methacrylate, ethyl methacrylate and vinyl chloride; the said polymeric film having a tensile strength, at its breaking point, which is less than the strength of the adhesive bond formed between the said pressure sensitive adhesive film and any solid substrate to which said pressure sensitive adhesive film may be adhered, thereby resulting in the mechanical rupture of said upper lamina when an attempt is made to remove the laminate from said solid substrate; said method comprising the steps of: (1) casting a solution of said polymeric film, in an organic solvent, onto a casting Sheet substrate having a nonabsorbent surface, a smooth finish and a low degree of adhesion for the resulting polymer film; (2) drying the polymeric film obtained in step (1) so as to remove the organic solvent therefrom; (3) casting a solution of said pressure sensitive adhesive, in an organic solvent, onto a silicone coated release sheet; (4) drying the pressure sensitive adhesive film obtained in step (3) so as to remove the organic solvent therefrom; (5) adhering the dry polymer film resulting from steps (1) and (2) onto the exposed surface of the pressure sensitive adhesive film resulting from steps (3) and (4) so that the polymer film and the pressure sensitive adhesive film are bonded in intimate, face-to-face contact with one another; (6) removing the casting sheet from the surface of the polymer film; and (7) removing the silicone coated release sheet from the surface of the pressure sensitive adhesive film, thereby resulting in the two-ply laminate which may then be adhered to any solid substrate via the exposed surface of the pressure sensitive adhesive film forming lower lamina of said laminate.