Dry paint transfer-laminate body panels having deep draw high DOI automotive paint coat

Abstract

An automotive quality paint coat is laminated to the exterior surface of a molded plastic car body member or panel. In one embodiment, the paint coat includes an exterior clear coat above a color coat. During processing, the clear coat and color coat are each coated on a temporary flexible casting sheet and dried. A high gloss surface is transferred to the clear coat from the casting sheet. The paint coat is then transferred from the casting sheet to a thin, semi-flexible thermoformable plastic backing sheet by dry paint transfer-laminating techniques. The resulting laminate is thermoformed into a complex three-dimensional shape of the car body member or panel. The preformed laminate is then bonded to an underlying plastic substrate material, by injection-cladding techniques, for example, to form the finished article. The paint coat has sufficient elongation to retain exterior automotive appearance and durability properties during thermoforming without deglossing. The backing sheet absorbs defects in the substrate material so the paint coat retains its appearance and durability properties during the injection-cladding step. The finished article comprises a high gloss, defect-free paint coat on the exterior of a molded plastic car body member or panel. Solution-form polyvinylidene fluoride/acrylic paint systems have remarkably high combined gloss and distinctiveness-of-image levels, together with durability properties required for exterior automotive use.

What is claimed is:  
     
         1 . A process for applying a paint coat, suitable for exterior automotive use, to a plastic exterior body panel of a motor vehicle, characterized by the steps of: 
 applying a clear coat ( 45 ) of a synthetic resinous material in thin film form onto a surface of a flexible casting sheet ( 42 ), and drying the clear coat on the casting sheet, the surface of the sheet having a specular reflectance for transferring to the surface of the dried clear coat a gloss level sufficient for exterior automotive use;    forming a color coat ( 46 ) of a pigmented synthetic resinous material which is dried and adhered to the clear coat;    transferring the dried clear coat and color coat to a semirigid backing sheet ( 72 ) of a synthetic resinous material to form a composite paint coat ( 44 ) bonded to a face of the backing sheet, in which the clear coat forms the exterior surface of the transferred paint coat and the color coat is bonded between the clear coat and the face of the backing sheet, and in which the exterior surface of the clear coat substantially retains the gloss transferred to it from its casting sheet;    thermoforming the backing sheet and the composite paint coat thereon to form a three-dimensionally shaped preformed laminate ( 116 ); and    placing the preformed laminate in a mold and molding a synthetic resinous substrate material ( 118 ) to the preformed laminate to form an exterior vehicle body panel ( 130 ) with a finished exterior automotive paint coat;    the clear coat comprising a material that substantially retains said gloss level during the thermoforming step; the backing sheet having sufficient thickness and sufficient elongation to absorb defects present in the substrate material to retain an essentially defect-free gloss on the clear coat surface following adherence of the laminate to the substrate material; the finished composite paint coat providing sufficient appearance and durability properties for use as an exterior automotive paint coat.    
     
     
         2 . The process according to  claim 1 , characterized in that the laminate ( 116 ) is thermoformed at a temperature greater than about 270° F., and the composite paint coat ( 44 ) elongates greater than about 40% during the thermoforming step while still retaining said gloss level and said exterior automotive appearance and durability properties.  
     
     
         3 . The process according to  claim 1 , characterized in that the clear coat ( 45 ) comprises a fluorinated polymer and acrylic resin-containing material.  
     
     
         4 . The process according to  claim 3 , characterized in that the clear coat ( 45 ) comprises a thermoplastic paint system in which the fluorinated polymer is selected from the group consisting of polyvinylidene fluoride, and copolymers and terpolymers of vinyfidene fluoride.  
     
     
         5 . The process according to  claim 4 , characterized in that the dried clear coat ( 45 ) contains less than about 70% polyvinylidene fluoride and less than about 50% acrylic resin, by weight of the total acrylic resin and PVDF solids present in the clear coat.  
     
     
         6 . The process according to  claim 1 , characterized in that the paint coat ( 44 ) has the minimum levels of gloss, distinctiveness-of-image, QUV, gasoline resistance, cleanability, acid resistance, hardness, abrasion resistance and impact strength, substantially as defined in the automotive specifications for exterior automotive paint finishes described herein.  
     
     
         7 . The process according to  claim 1 , characterized in that the preformed laminate ( 116 ) is molded to the substrate material ( 118 ) by injection cladding, reaction injection molding, or thermoset sheet molding techniques.  
     
     
         8 . The process according to  claim 1 , characterized in that the clear coat ( 45 ) applied to the casting sheet ( 42 ) comprises a thermoplastic paint system which includes polyvinylidene fluoride and an acrylic resin, in which the polyvinylidene fluoride is dispersed in a solution of the acrylic resin.  
     
     
         9 . The process according to  claim 1 , characterized in that the clear coat ( 45 ) applied to the casting sheet ( 42 ) comprises a thermoplastic paint system comprising a solution of polyvinylidene fluoride and acrylic resin.  
     
     
         10 . The process according to  claim 9 , characterized in that the finished paint coat ( 44 ) has a 60° gloss, level greater than about 75 gloss units and a distinctiveness-of-image level greater than about 80 units.  
     
     
         11 . The process according to  claim 1 , characterized in that the backing sheet ( 72 ) is a semirigid sheet with a thickness in the range from about 10 mils to about 40 mils.  
     
     
         12 . The process according to  claim 1 , characterized in that the backing sheet ( 72 ) is made from a material selected from the group consisting of ABS, polyester, amorphous nylon, and thermoplastic polyolefins, including polypropylene and polyethylene.  
     
     
         13 . The process according to  claim 1 , characterized by including applying a thin film of wax to the casting sheet ( 42 ) prior to casting the clear coat ( 45 ) on the casting sheet.  
     
     
         14 . The process according to  claim 1 , characterized in that a graphics pattern is printed between the clear coat ( 45 ) and the color coat ( 46 ).  
     
     
         15 . The process according to  claim 1 , characterized by a pigment contained in the backing sheet ( 72 ).  
     
     
         16 . The process according to  claim 1 , characterized by metallic flakes contained in the color coat ( 46 ), in which the flakes are aligned linearly when coated on a carrier film.  
     
     
         17 . The process according to  claim 1 , characterized in that a water soluble protective coating on the exterior surface of the paint coat ( 44 ).  
     
     
         18 . The process according to  claim 17 , characterized by the protective coating is overstamped on the clear coat ( 45 ).  
     
     
         19 . The process according to  claim 1 , characterized in that the thermoforming step is carried out by avoiding contact between the thermoforming apparatus ( 112 ) and the clear coat ( 45 ) side of the backing sheet ( 72 ).  
     
     
         20 . A thermoformable laminate for use in forming an exterior portion of an exterior car body panel, the laminate comprising a thin, semirigid backing sheet made from a synthetic resinous material, and an automotive quality paint coat bonded to a face of the backing sheet, in which the paint coat includes a synthetic resinous coating in dry thin film form having an exterior surface with a predetermined gloss level transferred to it from a high gloss casting sheet, the paint coat having sufficient elongation and resistance to deglossing such that the laminate is thermoformable into a highly contoured three-dimensional shape while the paint coat substantially retains said predetermined gloss level during thermoforming and provides predetermined appearance and durability properties sufficient to be useful as an exterior automotive paint coat following thermoforming of the laminate.  
     
     
         21 . The article according to  claim 20  in which the laminate can be thermoformed at a temperature of at least about 270° F., and the paint coat elongates greater than about 40% during thermoforming at said thermoforming temperature while still retaining said gloss level and said appearance and durability properties.  
     
     
         22 . The article according to  claim 20  in which the paint coat comprises a fluorinated polymer and acrylic resin-containing paint system with thermoplastic properties, in which the paint coat has been coated on a casting sheet and dried and then transferred from the casting sheer to the backing sheet.  
     
     
         23 . The article according to  claim 20  in which the paint coat comprises a thermoplastic paint system which includes polyvinylidene fluoride and an acrylic resin.  
     
     
         24 . The article according to  claim 23  in which the dried paint coat contains less than about 70% polyvinylidene fluoride and less than about 50% acrylic resin, by weight of the total PVDF and acrylic resin components contained in the paint coat.  
     
     
         25 . The article according to  claim 20  in which the paint coat comprises a pigmented synthetic resinous material with thermoplastic properties.  
     
     
         26 . The article according to  claim 20  in which the paint coat comprises an exterior clear coat and an underlying color coat bonded to the clear coat.  
     
     
         27 . The article according to  claim 26  in which the color coat contains a highly dispersed pigment, and in which the clear coat comprises a thermoplastic coating principally containing a fluorinated polymer and an acrylic resin.  
     
     
         28 . The article according to  claim 27  in which the clear coat is a thermoplastic paint system which consists essentially of about 50% to about 70% polyvinylidene fluoride and about 30% to about 50% acrylic resin; and in which the acrylic resin component comprises polymethyl methacrylate, polymethyl methacrylate, or mixtures thereof, including copolymers thereof.  
     
     
         29 . The article according to  claim 28  in which the color coat also consists essentially of about 50% to about 70% polyvinylidene fluoride and about 30% to about 50% acrylic resin; and in which the acrylic resin component comprises polymethyl methacrylate, polyethyl methacrylate, or mixtures thereof, including copolymers thereof.  
     
     
         30 . The article according to  claim 20  in which the paint coat on the thermoformed laminate has at least the minimum levels of gloss, distinctiveness-of-image, QUV, hardness, impact resistance, cleanability, acid resistance, gasoline resistance, and abrasion resistance, substantially as defined in the automotive specifications for exterior automotive paint finishes described herein.  
     
     
         31 . The article according to  claim 20  in which the paint coat includes a fluorinated polymer selected from the group consisting of polyvinylidene fluoride, and copolymers and terpolymers of vinylidene fluoride.  
     
     
         32 . The article according to  claim 20  in which the paint coat has a 60° gloss level greater than about 75 gloss units and a distinctiveness-of-image level greater than about 80 units.  
     
     
         33 . The article according to  claim 20  in which the backing sheet is a semirigid sheet with a thickness in the range from about 10 mils to about 40 mils.  
     
     
         34 . The article according to  claim 20  in which the backing sheet is made from a material selected from the group consisting of ABS, polyester, amorphous nylon, thermoplastic polyolefins, including polypropylene and polyethylene.  
     
     
         35 . The article according to  claim 20  including a wax film applied to the outer face of the clear coat from the casting sheet.  
     
     
         36 . The article according to  claim 20  in which a graphics pattern is printed between the paint coat and backing sheet and is visible through the paint coat.  
     
     
         37 . The article according to  claim 20  including a pigment contained in the backing sheet.  
     
     
         38 . The article according to  claim 20  including a metallic flake paint layer contained in the paint coat.  
     
     
         39 . The article according to  claim 20  including a water soluble protective coating on the exterior surface of the paint coat.  
     
     
         40 . An exterior plastic vehicles, the panel having automotive quality paint coat resinous thermoformable backing body panel for motor a synthetic resinous bonded to a synthetic sheet to form a laminate in which the exterior surface of the paint coat has exterior automotive gloss and distinctiveness-of-image levels, and in which the laminate has been thermoformed into a three-dimensional shape and adhered to a plastic substrate to form said plastic exterior body panel, the paint coat having sufficient elongation and resistance to deglossing to have substantially maintained said gloss and distinctiveness-of-image levels during thermoforming, the backing sheet having sufficient thickness and elongation to have absorbed defects in the substrate material, thereby providing said paint coat on the finished body panel with an essentially defect-free surface with the appearance and durability properties sufficient for exterior automotive use.  
     
     
         41 . The panel according to  claim 40  in which the paint coat comprises a thermoplastic fluorinated polymer and acrylic resin-containing paint system.  
     
     
         42 . The panel according to  claim 40  in which the finished paint coat has the minimum levels of gloss, distinctiveness-of-image, QUV, gasoline resistance, cleanability, acid resistance, hardness, abrasion resistance, and impact strength, substantially as defined in the automotive specifications for exterior automotive paint finishes described herein.  
     
     
         43 . The panel according to  claim 40  in which the paint coat comprises an exterior clear coat and an underlying color coat bonded to the clear coat.  
     
     
         44 . The panel according to  claim 43  in which the clear coat comprises a fluorinated polymer and acrylic resin-containing material with thermoplastic properties.  
     
     
         45 . The panel according to  claim 40  in which the paint coat includes a fluorinated polymer selected from the group consisting of polyvinylidene fluoride, and copolymers and terpolymers of vinglidene fluoride.  
     
     
         46 . The panel according to  claim 40  in which the paint coat has an 80° gloss level greater than about 75 gloss units and a distinctiveness-of-image level greater than about 80 units.  
     
     
         47 . The panel according to  claim 40  in which the backing sheet is a semirigid sheet with a thickness in the range from about 10 mils to about 40 mils.  
     
     
         48 . The panel according to  claim 40  in which the backing sheet is made from a material selected from the group consisting of ABS, polyester, amorphous nylon, and thermoplastic polyolefins including polypropylene and polyethylene.  
     
     
         49 . The panel according to  claim 40  including a wax film applied to the outer face of the clear coat from the casting sheet.  
     
     
         50 . The panel according to  claim 40  in which the preformed laminate is molded to the substrate material by injection cladding, reaction injection molding, or thermoset sheet molding techniques.  
     
     
         51 . The panel according to  claim 40  in which a graphics pattern is printed between the paint coat and backing sheet to be visible through the paint coat.  
     
     
         52 . The panel according to  claim 40  including a pigment contained in the backing sheet.  
     
     
         53 . The panel according to  claim 40  including metallic flakes contained in the paint coat.  
     
     
         54 . The panel according to  claim 40  including a water soluble protective coating on the paint coat.  
     
     
         55 . An exterior motor vehicle body panel comprising a plastic substrate, and a laminate on the exterior of the substrate, and a three-dimensionally thermoformed paint coat comprising a thermoplastic fluorinated polymer and acrylic resin-containing paint system that provides an exterior surface on said panel sufficient for exterior automotive use following thermo-forming of said paint coat, and in which the amounts of the fluorinated polymer and acrylic resin contained in the paint system are sufficient to resist deglossing of the paint coat during the thermoforming step so that a gloss level is provided in the finished panel, together with sufficient appearance and durability properties for exterior automotive use.  
     
     
         56 . The panel according to  claim 55  in which the fluorinated polymer is selected from the group consisting of polyvinylidene fluoride, and copolymers and terpolymers of vinylidene fluorlde.  
     
     
         57 . The panel according to  claim 55  in which the finished paint coat has a 60° gloss level greater than about 75 gloss units and a distinctiveness-of-image greater than about 80 units.  
     
     
         58 . The panel according to  claim 55  in which the paint coat has the minimum levels of gloss, distinctiveness of image, QUV, hardness, impact resistance, cleanability, acid resistance, gasoline resistance, and abrasion resistance, substantially as defined in the automotive specifications for exterior automotive paint finishes described herein.  
     
     
         59 . The panel according to  claim 55  in which the backing sheet is a semirigid sheet with a thickness in the range from about 10 mils to about 40 mils.  
     
     
         60 . The panel according to  claim 55  in which the backing sheet is made from a material selected from the group consisting of ABS, polyester, amorphous nylon, and thermoplastic polyolefins, including polypropylene and polyethylene.  
     
     
         61 . The panel according to  claim 55  in which the step of adhering the preformed laminate to the substrate material comprises injection cladding, reaction injection molding, or sheet molding compound techniques.  
     
     
         62 . A method of manufacturing a plastic exterior body panel for a motor vehicle having a paint coat with exterior automotive appearance and durability properties, the method comprising: 
 forming a laminate comprising a semirigid synthetic resinous backing sheet having a synthetic resinous paint coat adhered to a face of the backing sheet by dry transfer from a casting sheet, in which an exterior automotive gloss level is transferred to the exterior surface of the paint coat from the casting sheet;    thermoforming the laminate into a three-dimensional shape; and    placing the formed laminate in a mold and molding a plastic substrate material to the formed laminate to bond the laminate to the substrate and form a plastic car body panel with a finished paint coat;    in which the material comprising the paint coat substantially retains said gloss level during the thermoforming step; and    in which the backing sheet has sufficient thickness and elongation to absorb defects from the substrate material, so that the finished paint coat retains said gloss level during the step of molding the laminate to the substrate panel, the finished paint coat providing the appearance and durability properties sufficient for exterior automotive use.    
     
     
         63 . The method according to  claim 62  in which the paint coat comprises a fluorinated polymer and acrylic resin-containing material.  
     
     
         64 . The method according to  claim 62  in which the paint coat is cast as a thermoplastic paint system comprising a solution of polyvinylidene fluoride and acrylic resin.  
     
     
         65 . The method according to  claim 64  in which the paint coat has a gloss level greater than about 75 gloss units and a distinctiveness-of-image level greater than about 80 units.  
     
     
         66 . The method according to  claim 62  in which the paint coat is cast as a thermoplastic paint system which includes polyvinylidene fluoride and an acrylic resin, and in which the polyvinylidene fluoride is dispersed in a solution of the acrylic resin.  
     
     
         67 . The method according to  claim 62  in which the laminate is adhered to the substrate by injection cladding, reaction injection molding, or thermoset sheet molding techniques.  
     
     
         68 . The method according to  claim 62  in which the backing sheet is a semirigid sheet with a thickness in the range from about 10 mils to about 40 mils.  
     
     
         69 . The process according to  claim 62  in which the thermoforming step is carried Out by avoiding contact between the thermoforming apparatus and the paint coat on the backing sheet.  
     
     
         70 . A process for applying a paint coat, suitable for exterior automotive use, to a plastic exterior body panel of a motor vehicle, the process comprising the steps of: 
 applying a clear coat of a solution of vinylidene fluoride and acrylic resin in thin film form onto a surface of a flexible casting sheet, and drying the clear coat on the casting sheet, the surface of the sheet having a specular reflectance for transferring to the surface of the dried clear coat a gloss level sufficient for exterior automotive use;    casting a color coat of a pigmented solution of vinylidene fluoride and acrylic resin in thin-film form and drying the color coat;    transferring the dried clear coat and color coat to a semirigid backing sheet of a synthetic resinous material to form a composite paint coat bonded to a face of the backing sheet, in which the clear coat forms the exterior surface of the transferred paint coat and the color coat is bonded between the clear coat and the face of the backing sheet, and in which the exterior surface of the clear coat substantially retains the gloss transferred to it from the casting sheet;    thermoforming the backing sheet and the composite paint coat thereon to form a three-dimensionally shaped preformed laminate; and    adhering the preformed laminate to a synthetic resinous substrate material to form an exterior vehicle body panel;    the clear coat substantially retaining said gloss level during the thermoforming step; the backing sheet having sufficient thickness and sufficient elongation to absorb defects present in the substrate material to retain an essentially defect-free gloss on the clear coat surface following adherence of the laminate to the substrate material; the composite paint coat providin G  sufficient appearance and durability properties for use as an exterior automotive paint coat.    
     
     
         71 . The process according to  claim 70  in which the paint coat on the thermoformed laminate has a gloss level greater than about 75 gloss units and a dlstinctiveness-of-image level greater than about 80 units.  
     
     
         72 . The process according to  claim 70  in which the substrate is adhered to the laminate by injection cladding, reaction injection molding, or sheet molding compound techniques.  
     
     
         73 . The process according to  claim 70  in which the backing sheet is a semirigid sheet with a thickness in the range from about 10 mils to about 40 mils.  
     
     
         74 . The process according to  claim 70  in which the backing sheet is made from a material selected from the group consisting of ABS, polyester, amorphous nylon, thermoplastic polyolefins, including polypropylene and polyethylene.  
     
     
         75 . The process according to  claim 70  in which the paint coat is cast as a solution of polyvinylidene fluoride and acrylic resin.  
     
     
         76 . The process according to  claim 70  in which the finished paint coat has the minimum levels of gloss, distinctiveness-of-image, QUV, gasoline resistance, cleanability, acid resistance, hardness, abrasion resistance, and impact strength, substantially as defined in the automotive specifications for exterior automotive paint finishes described herein.  
     
     
         77 . The process according to  claim 70  in which the color coat includes metallic flakes aligned linearly, and the flakes have an average thickness of less than about 2000 Angstroms.  
     
     
         78 . The process according to  claim 77  in which the metallic flakes have a head-on brightness value greater than about 140 units.  
     
     
         79 . The process according to  claim 1  in which the color coat includes metallic flakes aligned linearly, and the flakes have an average thickness of less than about 2000 Angtroms.  
     
     
         80 . The process according to  claim 79  in which the metallic flakes have a head-on brightness value greater than about 140 units.