Building material having a fluorocarbon based capstock layer and process of manufacturing same with less dimensional distortion

Abstract

The present invention provides building materials and methods for the manufacturer which includes an extrudable thermoplastic or thermosetting substrate having a fluorocarbon-based capstock layer applied to the substrate. The fluorocarbon-based capstock layer can further include one or more top coats for providing a variegated, colored or textured pattern. The capstock layer, with or without the top coats, preferably has a thickness less than 4 mil and contains a UV-resistant PVDF resin.

1 . An exterior building material comprising: 
 a) a substrate containing PVC, polyethylene, polypropylene, polystyrene or mixtures thereof; and    b) a capstock layer applied directly to said substrate, said capstock layer comprising a fluorocarbon resinous composition.    
   
   
       2 . The building material of  claim 1  wherein said building material forms a portion of a roofing slate, tile or shake, a siding panel, a window profile, a decking member, a fencing member, or a trim board.  
   
   
       3 . The building material of  claim 1  comprising a variegated colored pattern layer disposed over said capstock layer.  
   
   
       4 . The building material of  claim 1  wherein said capstock layer comprises UV blocking properties.  
   
   
       5 . The building material of  claim 3  wherein said variegated colored layer comprises at least one top coating layer comprising a fluorocarbon resin, said capstock and top coating layer providing a variegated appearance indicative of a wood grain.  
   
   
       6 . The building material of  claim 1  wherein said capstock layer comprises long term weathering performance, mildew resistance, dirt repellency, and good adherence to said substrate.  
   
   
       7 . The building material of  claim 1  wherein said capstock layer comprises a formulated resin system comprising a copolymer of PVDF and Hexa Fluoro PVDF.  
   
   
       8 . The building material of  claim 1  wherein said capstock layer comprises a thickness of less than 4 mil.  
   
   
       9 . The building material of  claim 1  wherein said capstock layer comprises an opaque resinous formulation which is 100% resistant to UV penetration.  
   
   
       10 . A building material comprising a base substrate comprising PVC, a UV resistant capstock layer comprising PVDF or ASA, and a first top coat layer comprising PVDF resin, said capstock and top coating layer providing a variegated appearance indicative of a wood grain, without bowing said substrate in any significant way.  
   
   
       11 . The building material of  claim 10  further comprising a second top coat layer disposed over said first top coat layer to provide a variegated appearance, said second top coat layer having a different appearance from said first top coat.  
   
   
       12 . The building material of  claim 11  wherein said capstock layer comprises an opaque composition which is 100% resistant to UV penetration.  
   
   
       13 . The building material of  claim 12  wherein said capstock layer, said first top coat layer and said second top coat layer comprise a total thickness of about 4 mil or less.  
   
   
       14 . The building material of  claim 10  wherein said capstock layer self-adheres without a primer to said PVC-containing base substrate.  
   
   
       15 . A method of making an exterior building product comprising: 
 a) extruding a thermoplastic polymeric material comprising PVC, polyethylene, polypropylene, polystyrene, or mixtures thereof to form a base extrudate;    b) coating said base extrudate in line, while still hot, with a fluorocarbon-based or acrylic-based capstock layer; and    c) drying said capstock layer to form a UV-resistant protective layer on said base extrudate.    
   
   
       16 . The method of  claim 15  wherein said coating step (b) comprises spraying, printing or painting said fluorocarbon-based capstock layer without a primer layer.  
   
   
       17 . The method of  claim 15  wherein said coating step (b) comprises employing one or more of a paint spraying step, an ink jet printing step, or a gravure roll printing step.  
   
   
       18 . The method of  claim 15  wherein said drying step (c) relies, at least in part, upon heat generated by said extruding step.  
   
   
       19 . The method of  claim 15  wherein said capstock layer comprises a thickness of less than 4 mil.  
   
   
       20 . A method of making an exterior building product including siding, window profiles, decking, fencing, trim boards, or a combination thereof, comprising: 
 a) extruding a thermoplastic polymeric material comprising PVC to form a base extrudate having an elevated temperature;    b) coating said base extrudate in line, with a UV-resistant PVDF-based liquid capstock layer while said extrudate is still hot, and permitting said liquid capstock layer to dry, whereby said dried capstock and top coat layers form a variegated pattern having a thickness of about 4 mil or less, without warping or bowing said exterior building product.    c) applying at least one top coat to said capstock layer to provide a variegated appearance, and permitting said top coat to dry.    
   
   
       21 . A roofing slate, tile or shake made from the process of  claim 15 .  
   
   
       22 . A siding panel made from the process of  claim 15 .  
   
   
       23 . A window profile made from the process of  claim 15 .  
   
   
       24 . A decking member made from the process of  claim 15 .  
   
   
       25 . A fencing member made from the process of  claim 15 .  
   
   
       26 . A trim board made from the process of  claim 15.