MXPA97006268A - Polymeric film protecotra for lamination to me - Google Patents

Abstract

The present invention provides a protective polymer film that can be laminated to a metallic substrate (18) and that provides protection against scrapes, solvents and corrosion. The film also exhibits good compression and sealing ability when used to form metal containers such as air valve assembly cups, can domes, bodies, bottoms and the like. The protective polymeric film includes a scratch-resistant layer (10) having a Shore D hardness of at least 60, an adhesive layer (14) and a compressible layer (12) placed between the scratch and adhesive resistant layers. In an alternative embodiment, the protective film includes a scratch-resistant layer and a compressible adhesive layer. The film can be laminated to a metal substrate by thermally activating the adhesive layer

Description

FILM P0L1 PROTECTIVE METAL FOR METAL LAMINATION The present invention relates to a polymeric protective film that can be easily laminated to metal substrates to provide protection from scrapes, solvents and corrosion and exhibits good sealing and compressibility when the laminate is used to form metal containers. Polymer protective films or coatings are known in the art, which can be laminated to metals such as tin-free steel, tin-plated steel and aluminum and then formed into parts such as aerosol valve mounting cups, domes or bottoms, cans of paint, containers for food and beverages and the like. Said films or coatings are used to protect the underlying metal surface from corrosion as well as to provide resistance to solvents and abrasions. For example, the Patent of E.U.A. DO NOT. No. 4,626,157 to Franek et al., Discloses a method for making metal containers such as aerosol dispensing containers having upper end members of the can and valve cup members formed of a metal laminate comprising a thin polymeric cover such as a polyester layer or polypropylene in the metallic substrate. However, while such films provide resistance to corrosion, solvents and abrasions, due to the high modulus of the polypropylene film, the metal / film laminates using polypropylene do not exhibit good sealing and compressibility when used to make metal containers such like aerosol cans. Specifically, said films do not form a good seal for joints formed by compression or seals between two pieces of a metal laminate. Said poor sealing can result in the leakage of pressurized propellant from a metallic aerosol container formed of the metallic laminate. In addition, it has been found that polypropylene is difficult to adhere to various metal substrates. Many commercial polypropylene film laminates currently in use adhere to the metal with solvent-based adhesives such as urethane adhesives. However, said adhesives are undesirable since they are not environmentally friendly and leave the potential for residual solvents of the metal container. Additionally, inadequate curing of the adhesive can result in the loss of adhesion of the sheet material to film, particularly following exposure to solvents that may be contained within the fabricated structure. As a result, more recently polymeric films have been laminated to resins of metal-using thermoplastic adhesives. For example, the Patent of E.U.A. No. 4,980,210 to Heyes et al., Discloses a two-layer film bonded to the surface of a sheet of metal comprising an inner adhesive layer of a modified polyolefin acid resin and an outer layer of a polyolefin. In an attempt to solve the problems of sealing ability and compressibility associated with polypropylene adhesive films, the Patent of E. U.A. No. 5,006, 383 to Achule et al., Teaches a mixture of polypropylene and very low density polyethylene and a layer of adhesives comprising a rubber and a modified amallene polymeric resin of polar comonomer. However, while said films exhibit good compressibility and formability, the films can not provide sufficient resistance to abrasions and scrapes. For example, during the handling, bulk packing and shipping of aerosol valve mounting cups, said example of film during handling, bulk packing and shipping of the aerosol valve mounting cups, said laminates of The film can possibly be damaged by notching, scraping or stinging as the metal layers vibrate or move against each other. The damage can also occur during part of the stamping or forming if the stamping dies and assembly mechanisms are not perfectly aligned. If the protective polymer film is damaged, the corrosion resistance of the aerosol valve mounting cups is also weakened. Accordingly, there is still a need in the art for a protective film that can easily be laminated to a metal substrate without the use of a solvent-based adhesive, which exhibits good sealing and compressibility and which is resistant to scratching as well as resistant to solvents and corrosion.

The present invention meets the need to provide a protective polymeric film that can be easily laminated to a metal substrate, which is resistant to scratches, solvents and corrosion and exhibits good sealing and compressibility when used to form metal containers. The film can be produced by conventional coextrusion techniques. According to one aspect of the present invention, a protective polymeric film is provided comprising an adhesive layer comprising from 5 to 25 percent of the thickness of the total film, a scratch resistant layer comprising from 5 to 40 percent of the total thickness of the film and a layer of compression placed between the layers resistant to the adhesive and to the scrape comprising from 40 to 80 percent of the total thickness of the film. The scrape resistant layer preferably has a hardness of ASTM D2240 Shore D of at least 60, and the compressible adhesive layers have a Shore D hardness that is less than that of the scrape resistant layer. Additionally, if it is desired that the scratch resistant layer has a pencil hardness of ASTM D3363 of at least 3B, and preferably at least B. Preferably, the adhesive layer is selected from the group consisting of ethylenically unsaturated copolymers of vinyl acetate, ethyl acrylate, ethyl methacrylate, methylacrylic acid, acrylic acid or carbon monoxide, ethylene or propylene homopolymers; ethylene and propylene copolymers; ionomers of ethylene and methacrylic acid or acrylic acid; polyethylene modified with maleic anhydride; polyamides; polyurethanes; or compatible mixtures thereof. The adhesive layer is preferably thermally activated for lamination to a metal substrate and is solvent free. The scrape resistant layer is preferably selected from the group consisting of polypropylene, polyethylene, polyester, polyamide, and mixtures thereof. Once the protective film is laminated to a metal substrate, the hard scratch resistant layer works to protect the underlying metal from scrapes, and provides resistance to solvents and corrosion. Optionally, the scrape resistant layer can be coated with curable hard coatings selected from the group consisting of urethane, epoxy, acrylic silicone to provide improved scrap resistance properties. The scratch resistant layer may also contain an inorganic filter to further harden the layer and improve the scrape resistance. Radiation-induced entanglement can also be used to further increase the hardness and scrap resistance properties of the scrape-resistant layer. The compression layer preferably comprises ethylene or propylene homopolymers, ethylene and propylene copolymers, ethylene-propylene rubbers, thermoplastic olefin elastomer resins, styrene block copolymers, polyurethane and mixtures thereof. The compression layer is a softer polymeric film layer that provides good sealing ability and compression properties when the protective film is laminated to a metal substrate and used to fabricate metal containers in a preferred embodiment of the invention, the compression layer is foamed using a chemical blowing agent to provide improved compressibility. The protective polymeric film of the present invention preferably has a thickness of 0.013 to 0.51 mm. In a preferred embodiment of the invention, the protective polymeric film is bonded to at least one major surface of a metal substrate to form a metal laminate wherein the film comprises abrasion resistant, adhesive and compressible layers as described above . Suitable metallic substrates range from 0.13 to 2.5 mm in thickness preferably from 0.13 to 0.38 mm in thickness. The protective polymeric film is preferably laminated to the metal laminate by thermally activating the adhesive layer and bonding the adhesive layer to the metal laminate. The film shall exhibit at least 89 kg / cm of film adhesion to the metal when subjected to a 180 degree thin coating release test in accordance with ASTM D-903. Thus, the scrape resistant layer becomes the exposed outer protective layer of the metal laminate and the flat compressible layer becomes the outer protective layer remains between the adhesive and scratch resistant layers. The protective film protects the underlying metal substrate from scratches that could expose the metal to solvents and corrosion. In an alternative embodiment of the invention, a protective polymeric film is provided, which includes a scrape-resistant layer and an adjacent layer which has both compressible and adhesive properties. The compressible adhesive layer comprises from 10 to 90 percent of the total thickness of the film and the scrape resistant layer comprises from 10 to 90 percent of the total thickness of the film. The scrap-resistant layer has a Shore D hardness of at least 60, and the compressible adhesive layer has a Shore D hardness that is less than that of the scrape-resistant layer. Additionally, it is desired that the scratch resistant layer have a pencil hardness of ASTM D 3363 of at least 3B, and preferably at least B. The compressible adhesive layer is preferably selected from the group consisting of ethylenically unsaturated acetate copolymers of vinyl, ethyl acrylate, ethyl methacrylate, methylacrylic acid, acrylic acid, carbon monoxide, ethylene or propylene homopolymers, copolymers of ethylene and propylene, ionomers of ethylene and methylacrylic acid or acrylic acid, grafted anhydride copolymers, polyamides, polyurethanes and compatible mixture thereof. Preferably, foam is applied to the compressible adhesive layer. The scrape resistant layer is preferably selected from the group consisting of polypropylene, polyethylene, polyester, polyamide or mixtures thereof. The scrape resistant layer may be coated with curable, interlaced coatings or may include organic fillers as described above to provide increased scrap resistance. The polymeric protective film of the present invention can be laminated to metals such as tin-free steel, tin-plated steel and aluminum. In one embodiment of the invention, the protective polymeric film is laminated to tin-plated steel to form an aerosol valve mounting cup. The protective film of the present invention can also be manufactured in a number of other parts including aerosol can domes, can bottoms, paint cans, metal trays, pans, and the like. Accordingly, it is an aspect of the present invention to provide a protective polymeric film that can be laminated to a metal substrate. It is a further aspect of the invention to provide a protective polymeric film which provides resistance to scrapes, solvents and corrosion and exhibits good sealing and compressibility when used in the manufacture of metal containers. These and other aspects and advantages of the present invention will be apparent from the following detailed description, the accompanying drawings and the appended claims. Figure 1 is a cross-sectional view of the protective polymeric film of the present invention showing raspable, com printable and adhesive resistant layers.

Figure 2 is a cross-sectional view of an alternative embodiment of the protective film comprising layers of scratch-resistant and compressible adhesives; Figure 3 is a variation of the embodiment shown in Figure 1, in which the film has been laminated to a metal substrate; and Figure 4 is a perspective view of an aerosol valve mounting cup that has been formed of the protective film of the present invention. The film / metal laminated polymeric protective film of the present invention provides a combination of properties that have not been achieved by the protective films of the prior art. The present invention utilizes a smooth film layer that exhibits good compression and sealing properties in combination with a hard film layer that resists scrapes and abrasions that could expose the underlying metal surface and subject it to corrosion. The film of the present invention can be easily laminated to a metal substrate by thermally activating a layer of solvent-free adhesive film and the resulting metal laminate can be formed into metallic containers that protect against scrapes, solvents and corrosion. The bond formed between the adhesive film layer and the metal substrate is strong and durable. Depending on the desired end use, the laminate of the present invention can resist delamination or detach the film from the metal substrate after 30 days immersion in methylene chloride. The protective polymeric film of the present invention may comprise either a 3-layer film comprising compressible and scratch-resistant adhesive layers or a two-layer film comprising a scratch-resistant layer and an adjacent layer having both properties compressible as adhesive. Referring now to Figure 1, the embodiment of the protective polymeric film of the present invention is illustrated. The film includes a scratch-resistant layer 10, a layer of adhesive 14, and a compressible layer 12 placed between the scratch-resistant layer and the adhesive layer. The scratch resistant layer exhibits a hardness of the Shore D hardness meter of at least 60 tested in accordance with ASTM D2240. A resistance to pencil scratches of at least a "3B" rating in accordance with ASTM D3363 is also preferable. Films suitable for use as the scratch resistant layer include polypropylene, polyethylene, polyester, polyamide, and mixtures thereof having the required hardness. Although olefin resins such as polypropylene and polyethylene are preferred, other suitable resins include polyester and polyamide or nylon resins. However, it is preferred that the scratch resistant layer should be comprised of more than 80 percent polypropylene to provide the desired scratch resistance properties. The scratch resistant layer 10 can be coated with hard curable coatings such as urethanes, epoxy, acrylic or silicones to provide improved scratch resistance or surface abrasion. Additives such as inorganic fillers or chemical-induced interlacing or radiation can also be used to further increase the hardness and scrape resistance of the scratch-resistant layer. The compressible layer 12 can be produced from homopolymers of ethylene or propylene, copolymers of ethylene and propylene, ethylene-propylene or other olefinic rubbers. Thermoplastic elastomers such as styrenic block copolymers, polyurethane or mixtures of those resins are also suitable for use in the present invention. The compressible layer is preferably foamed using chemical blowing agents such as mixtures of sodium bicarbonate-citric acid or azodicarbonamide. The foamable layer provides improved compression on a layer of conventionally extruded solid. Suitable adhesive polymers useful as the adhesive layer 14 include, but are not limited to ethylenically unsaturated copolymers of vinyl acetate, ethyl acrylate, methyl acrylic acid, acrylic acid and carbon monoxide. Other examples include homopolymers of ethylene or propylene, copolymers of ethylene and propylene, lonomers of ethylene and metacrylic acid or acrylic acid, copolymers of grafted anhydride, polyamides, polyurethanes and compatible mixtures thereof. The adhesive layer should be easily adhered to the compression layer as well as to a metal substrate. Generally, the scratch resistant layer comprises to 40 percent of the total thickness of the film, the compressible layer comprises from 40 to 80 percent of the total film thickness and the adhesive layer comprises from 5 to 25 percent of the total thickness of the film. A more preferred structure for the three layer film is a scrape resistant layer comprising 20 percent of the total thickness, a compressible layer comprising 65 percent of the total thickness and an adhesive layer comprising 15 percent of the total thickness . An alternative embodiment of the invention is illustrated in Fig. 2, in which the film comprises a compressible adhesive layer 16 and a scrape resistant layer 10. In this embodiment, the compressible adhesive layer preferably comprises 75 percent of the Total thickness of the film and the scrape resistant layer comprises 25 percent of the total thickness of the film. The scrape resistant layer may comprise polypropylene, polyethylene, polyester, polyamide, and mixtures thereof, with polypropylene being more preferred. Resins suitable for use as the compressible adhesive layer include ethylenically unsaturated copolymers of vinyl acetate, ethyl acrylate, ethyl methacrylate, methylacrylic acid, acrylic acid, carbon monoxide, ethylene or propylene homopolymers, copolymers of ethylene and propylene, ionomers of ethylene and methylacrylic acid or acrylic acid, grafted anhydride copolymers, polyamides, polyurethanes and compatible mixtures thereof. The protective polymeric film of the present invention is preferably produced by a co-extrusion process in a conventional casting film line or tubular blowing film line. The layers can be coextruded together and the resulting protective film can then be thermally laminated to a metal substrate using a hot roll laminator. A metal laminate is shown in Figure 3 in which the adhesive layer 14 adheres to a metal substrate 18 with the scrape resistant layer 10 forming an outer protective layer for the metal. The metal can be coated on one or both sides with the same or different protective films. The resulting metal laminate can be used to make a variety of parts such as aerosol valve mounting cups, aerosol can domes, spray can bottoms, paint cans, metal pans or trays, and the like. Figure 4 illustrates an assembly cup of the aerosol valve 20 formed by stamping the metal laminate formed of the protective film of the present invention. The compressible layer 12 allows the film to be easily compressed to manufacture said parts and also provides a good seal, so that during rippling operations when the mounting cup of the aerosol valve is then corrugated to a can body. It should also be appreciated that the protective film can be laminated on both sides of a metal substrate. For example, the thickness of the film can be 0.13 mm to 0.25 mm on the inside of an aerosol valve mounting cup, forming a seal gasket and 0.025 mm to 0.05 mm on the outside of the cup , forming a scratch resistant and corrosion resistant coating. In order that the invention may be more easily understood, reference is made to the following examples, which are intended to be illustrative of the invention but are not intended to limit the scope. Example 1 A three-layer polymeric protective film was produced in accordance with the present invention in a conventional cast film line. The scrape resistant layer, which comprised 25 percent of the total thickness of the film, was comprised of a polypropylene homopolymer (Himont ProFax ™ PD-064). The compressible layer comprised 60 percent of the total thickness of the film and was comprised of of a blend of 50 percent polypropylene (Himont ProFax PD-064) and 50 percent ultra low density polyethylene (Dow Chemical ATTAN E® 4201). The adhesive layer comprised 15 percent of the total film thickness and was comprised of a blend of 60 percent linear modified low density polyethylene maleic anhydride from Quantum Chemical PlexarTM 360 and 40 percent modified high density polyethylene. maleic anhydride from Quantum Chemical Plexar ™ 206. Each layer was extruded at temperatures of 204-210 ° C with a dye temperature of 210 ° C. The co-extruded film was cooled on a casting roll at 38 ° C and then wound on a roll. The resulting 0.2 mm thick film was then thermally laminated to a tin-plated steel of 0.27 mm at 177 ° C using a roller laminator. The film exhibited film adhesion greater than 1.8 kg / cm when subjected to the 180 degree thin coating release test using an I nstron tension tester (ASTM D-903). The resulting sheet material was successfully stamped into aerosol valve mounting cups in a progressive multi-station die. The film maintained excellent adhesion to the formed mounting cup. Example 2 A coextruded film of 0.2 mm thickness of three layers was produced in a conventional cast film line. The outermost scrape resistant layer, which was 20 percent of the total film size, was comprised of a polypropylene random copolymer (H imont Profax 7531). The compressible layer (60 percent film gauge) was comprised of 50 percent of a mixture of polypropylene random copolymer (H imont ProFax 7531) 50 percent low density polyethylene (Dow Chemical ATTAN E 4202). The adhesive layer (15 percent film gauge) was comprised of a mixture of 60n percent linear modified low density polyethylene maleic anhydride Quantum Plexar 360 and 40 percent modified high density polyethylene, anhydride, melenic anhydride. Quantum Chemical Plexar. Each layer was extruded at temperatures of 204-210 ° C with a die temperature of 210 ° C. The film was quenched on a casting roll at 38 ° C and then wound on a roll. The 0.2 mm film was then thermally laminated with tin-plated steel at 0.27 mm at 1 77 ° C using a hot roll laminator. The resulting laminate was successfully stamped into the mounting cups of the aerosol valve in a multi-station progressive die. Example 3 Another 0.2 mm three layer protective polymeric film was prepared as in Example 1. The scrap-resistant layer comprised 25 percent of the total film thickness and was comprised of a polypropylene homopolymer (Himont ProFax ™ PD-064). The compressible layer comprised 6 percent of the total thickness of the film and was comprised of ethylene copolymer of the metallocene catalyst (Dow AFFINITY® PL-1840). The adhesive layer comprised 15 percent of the total film thickness of 100 percent of the modified linear low density polyethylene maleic anhydride of Quantum Chemical PlexarTM 360. Each layer was coextruded as described in Example 1 and the resulting film was extinguished and thermally laminated to a tinplate sheet of 0.27 mm. Example 4 A three-layer protective polymeric film was prepared as in Example 1. The scratch-resistant layer (25 percent of the total film thickness) was comprised of a polypropylene homopolymer (himont ProFax ™ PD-064). The compressible layer (60 percent of the total film thickness) was comprised of a mixture of 50 percent polypropylene (Himont ProFaxTM PD-191) and 50 percent ultra low density polyethylene (Dow Chemical ATTANE® 4201) with 1.5 phr of foam concentrate based on sodium bicarbonate-citric acid (Henley HydrocerolTM DF-20). The endothermic blowing agent was activated during extrusion to produce a compressible layer of closed cell foam very finely. The adhesive layer (15 percent of the total film thickness) was comprised of 100 percent modified linear low density polyethylene maleic anhydride from Quantum Chemical Plexar ™ 360. Each layer was extruded as described in Example 1, and the The resulting film was extinguished and thermally laminated to a tin-plated steel of 0.27 mm. EXAMPLE 5 A three-layer protective polymeric film was prepared as in Example 1 comprising a scratch-resistant layer (25 percent of the total film thickness) of a polypropylene homopolymer (Himont ProFax ™ PD-064), a compressible layer (60 percent of the total film thickness) comprising a blend of 65 percent polypropylene (Himont ProFaxTM PD-064) and 35 percent ethylene-propylene rubber (Exxon Chemical VistalonTM 3708P). The adhesive layer was comprised of 100 percent modified linear low density polyethylene maleic anhydride from Quantum Chemical Plexar ™ 360. Each layer was extruded as in Example 1 and the resulting film was quenched and thermally laminated to a steel plated with tin. Example 6 A 0.2 mm thick two layer polymeric film was produced in a line of conventional casting film. The scrap-resistant layer comprised 80 percent of the total film thickness and was comprised of 50 percent polypropylene (ProFaxTM PD-064) and 50 percent ultra low density polyethylene blend (ATTANE® 4201) . The adhesive layer comprised 20 percent of the total film thickness and was comprised of a blend of 60 percent PlexarTM 360 linear low density polyethylene and 40 percent PlexarTM 206 high density polyethylene. The resulting film was laminated thermally to tin-plated steel and stamped into an aerosol valve mounting cup as described in Example 1. Example 7 Polypropylene, polyethylene, Plexar adhesives and blends, including those described in Examples 1-5, were hot pressed into 0.32 cm plates using a heated platinised press. The polymer plates were then tested for durometer hardness using a durometer tester from Pacific Transducer Corp. Model 409 type D according to ASTM D2240. The results are shown in Table 1: Example 8 A pencil hardness test (ASTM D-3363) was used to determine the scrape resistance of the plates in Example 7. A group of Eberhard Faber Design Drawing 3800 pencils with sticks hardness ranging from 6H (hard) to 6B (soft) were used to quantify the hardness or resistance to scraping of various polymer blends given in Example 7. The results are shown in Table II below. As can be seen, plates containing polypropylene or mixtures of polypropylene and ultra-low density polyethylene exhibit the highest scratch resistance. Example 9 In order to compare the relative abuse resistance of a film laminate with 100 percent of a polypropylene protective layer with that of a film laminate with a protective layer comprised of 50 percent polypropylene and 50 percent of linear ultra low density polyethylene, the assembly cups of the aerosol valve produced from the laminates described in Example 1 and Example 6, respectively, were subjected to an evaluation of vibratory agitation. Five aerosol valve assembly cups from each sample were placed in 265.5 ml empty bottles, which were mounted on a Lab-Line Instruments Multi-Wrist stirrer. The five identical laminated metal mounting cups in each of the bottles were subjected to vigorous stirring by setting the instrument at 10 (maximum) for five minutes. The cups were then removed and inspected for damage in the form of notches, scrapes or abrasion on the laminated side of the film using a magnifying optical magnifier 10x. The cups of Example 6 (50 percent polypropylene top layer - 50 percent ultra low density polyethylene) exhibited an average of 22 notches damaging the surface on the sheet, while the cups of Example 1 (100 percent the polypropylene top layer) exhibited an average of only 9 notches damaging the surface. While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made to the methods and apparatuses described herein without departing from the scope of the invention, which defined in the appended claims.

Claims (3)

1. CLAIMS 1. A protective film comprising: a) a scratch resistant layer, said scratch resistant layer exhibiting a hardness of the Shore D hardness meter of at least 60 tested in accordance with ASTM D2240, said scratch resistant layer comprising 5 percent to 40 percent of the total film thickness; b) a compressible layer adjacent to said scratch resistant layer, said compressible layer comprising homopolymers of ethylene or propylene, copolymers of ethylene and propylene, ethylene-propylene rubbers, olefinic elastomeric resins, styrene block copolymers, polyurethane or mixtures of them, said compressible layer comprising from 40 percent to 80 percent of the total thickness of the protective film; and c) an adhesive layer adjacent said compressible layer, said adhesive layer comprising ethylenically unsaturated copolymers of vinyl acetate, ethyl acrylate, ethyl methacrylate, methylacrylic acid, acrylic acid or carbon monoxide; ethylene or propylene homopolymers; ethylene and propylene copolymers; ionomers of ethylene and methacrylic acid or acrylic acid; polyethylene modified with maleic anhydride; polyamides; polyurethane; or compatible blends thereof, said adhesive layer comprising from 5 percent to 25 percent of the total thickness of the protective film, and said adhesive layer capable of exhibiting at least 0.89 kg / cm of film adhesion to metal substrates when they undergo a 180 degree thin coating test in accordance with ASTM D903, where the total thickness of the protective film is 0.01 to 0.51 mm thick.
2. 2. A film according to claim 1, wherein the scrape resistant layer comprises more than 80 percent polypropylene.
3. 3. A film according to claim 1, wherein the compressible layer consists essentially of a mixture of polypropylene and polyethylene. A film according to claim 1, wherein the adhesive layer consists essentially of a mixture of polyethylenes modified with maleic anhydride. 6. A metal laminate comprising a protective polymeric film bonded to at least one major surface of a metallic substrate, said polymeric film comprising an adhesive layer comprising from 5 to 25 percent of the total thickness of the film, a compressible layer comprising 40 at 80 percent of the total thickness of the film, a scrape-resistant layer comprising from 5 to 40 percent of the total thickness of the film, said scrape-resistant layer having a Shore D hardness of at least 60, and said compressible and compressible layers having a Shore D hardness less than said scratch resistant layer. A metal laminate according to claim 6, wherein said adhesive layer is selected from the group consisting of ethylenically unsaturated copolymers of vinyl acetate, ethyl acrylate, ethyl methacrylate, methylacrylic acid, acrylic acid or carbon monoxide.; ethylene or propylene homopolymers; ethylene and propylene copolymers; ionomers of ethylene and methacrylic acid or acrylic acid; modified maleic anhydride polyethylene; polyamides; polyurethanes; or compatible mixtures thereof. A metal laminate according to claim 6, wherein said scratch resistant layer is selected from the group consisting of polypropylene, polyethylene, polyester, polyamide and mixtures thereof. 9. A metal laminate according to claim 6, wherein said compressible layer comprises ethylene or propylene homopolymers, ethylene-propylene copolymers, ethylene-propylene rubbers, oeffinic resins, styrene block copolymers, polyurethane, and mixtures thereof. same. 10. A metal laminate according to claim 6, wherein said compressible layer is foam. 11. A metal laminate according to claim 6, wherein said scratch-resistant layer includes a curable coating selected from the group consisting of urethane, epoxy, acrylic and silicone. 12. A metal laminate according to claim 6, wherein said scratch-resistant layer contains an inorganic filler. 13. A metal laminate according to claim 6, wherein said scratch-resistant layer has been interlaced. 14. An aerosol valve mounting cup formed of a metal-laminated protective polymeric film, said protective film comprising an adhesive layer comprising from 5 to 25 percent of the total thickness of the film, a compressible layer comprising from 40 to 80 percent of the total thickness of the film and a scratch-resistant layer comprising from 5 to 40 percent of the total thickness of the film, said scratch-resistant layer having a Shore D hardness of at least 60, and said layers adhesive and compressible having a Shore D hardness less than said scratch resistant layer.