Thermally Reactive Ink Transfer System

Abstract

An ink transfer system including an ink transfer decal that is transferable to a final substrate, such as a bare metal or pre-painted autobody part, without use of a separate adhesive. The transferred ink decal is capable of withstanding temperature elevations common during automotive paint baking without significant thermal degradation, discoloration, shrinkage or pealing.

1 . A coating transfer system comprising:
 a flexible backing sheet having a surface adapted to releaseably receive polymer resins; and   an ink transfer coating printed upon a portion of said sheet, said ink transfer coating comprising a thermoplastic polymer resin, a UV stabilizer to inhibit photo degradation of polymers formed from said resin, and an antioxidant to inhibit oxidative degradation of polymers formed from said resin, said ink transfer coating being releaseably received on said sheet,   said system being constructed without a separately applied adhesive.   
   
   
       2 . The coating transfer system of  claim 1 , wherein said resin comprises a member selected from the group consisting of aliphatic polyurethanes, polyester-based polyurethanes, the reaction product of at least one diisocyanate and a polyol, and diphenylmethane diisocyanates. 
   
   
       3 . The coating transfer system of  claim 1 , wherein said resin comprises at least one component selected from the group consisting of 4,4′ diphenylmethane diisocyanate, 4,2′ diphenylmethane diisocyanate and 2,2′ diphenylmethane diisocyanate. 
   
   
       4 . The coating transfer system of  claim 1 , wherein said UV stabilizer comprises a UV absorbing compound. 
   
   
       5 . The coating transfer system of  claim 1 , wherein said UV stabilizer comprises a hindered amine. 
   
   
       6 . The coating transfer system of  claim 1 , wherein said UV stabilizer is selected from the group consisting of hydroxyl substituted benzophenones and hydroxyl substituted benzotriazoles. 
   
   
       7 . The coating transfer system of  claim 1 , wherein said UV stabilizer is selected from the group consisting of hydroxyphenyl-benzotriazoles, hydroxyphenyl-triazines, hydroxy-benzophenones and oxalic anilides. 
   
   
       8 . The coating transfer system of  claim 1 , wherein said UV stabilizer comprises a hindered amine light stabilizer derived from a member selected from the group consisting of 2,2,6,6-tetraalkyl piperidine, a substituted piperizinedione, and decanedioic acid. 
   
   
       9 . The coating transfer system of  claim 1 , wherein said antioxidant comprises a sterically hindered phenolic compound. 
   
   
       10 . The coating transfer system of  claim 1 , wherein said ink transfer coating softens and adheres to a receiving substrate when said ink transfer coating is heated to a temperature between 185° F. and 375° F. 
   
   
       11 . The coating transfer system of  claim 1 , further comprising a release layer deposited upon said ink transfer coating. 
   
   
       12 . The coating transfer system of  claim 1 , said ink transfer coating further comprising free isocyanate compounds. 
   
   
       13 . The coating transfer system of  claim 1 , said flexible backing sheet being water slide decal paper. 
   
   
       14 . The coating transfer system of  claim 1 , said ink transfer coating comprising one or more separately applied ink layers, each of said one or more ink layers being formed by printing a solvent-containing ink onto said sheet, said ink being capable of drying by solvent evaporation at ambient conditions within one hour of application to said sheet. 
   
   
       15 . The coating transfer system of  claim 14 , said ink transfer coating further comprising a transparent base coat in addition to said one or more ink layers. 
   
   
       16 . The coating transfer system of  claim 1 , wherein said ink transfer coating may be stretched to elongate greater than 400%. 
   
   
       17 . The coating transfer system of  claim 1 , wherein after removal of said backing sheet and after said ink transfer coating is placed in contact with a pre-painted substrate and heated to a temperature of 185° F. or above, polymers formed from said resin migrate into said substrate thereby permanently bonding said ink transfer coating with said pre-painted substrate without a separately applied adhesive. 
   
   
       18 . A method of transferring a solid ink design to a substrate comprising the steps of:
 (a) providing a decal that does not include a separately applied adhesive, said decal comprising—
 (i) a flexible backing sheet having a surface adapted to releaseably receive polymer resins, and 
 (ii) an ink transfer coating comprising one or more ink layers and, optionally, a transparent base coat, each of said one or more ink layers and optional base coat being printed onto said sheet as a liquid comprising a thermoplastic polymer resin, a UV stabilizer to inhibit photo degradation of polymers formed from said resin, an antioxidant to inhibit oxidative degradation of polymers formed from said resin, and a solvent system, said liquid from which any of said one or more ink layers and optional base coat are formed being capable of drying on said sheet by solvent evaporation upon being allowed to dry for one hour at ambient conditions; 
   (b) removing said flexible backing sheet from said decal to expose a surface of said ink transfer coating; and   (c) applying said exposed surface to said substrate.   
   
   
       19 . The method according to  claim 18 , said flexible backing sheet comprising water slide decal paper. 
   
   
       20 . The method according to  claim 19 , step (b) including wetting said backing sheet prior to removing said backing sheet from said decal. 
   
   
       21 . The method according to  claim 20 , step (b) including removing excess moisture from between said ink transfer coating and said substrate. 
   
   
       22 . The method according to  claim 21 , step (b) including drying substantially all surface moisture from said decal. 
   
   
       23 . The method according to  claim 1 , said method further comprising:
 (d) applying a clear coat over said substrate and said ink transfer coating after step (c) with no raised transition between said substrate and said ink transfer coating being perceptible to the touch or to the naked eye after said clear coat application.   
   
   
       24 . The method according to  claim 23 , after step (d), baking said clear coat at a temperature of between 250 to 325° F. thereby fusing said ink transfer coating to said substrate and said clear coat. 
   
   
       25 . The method according to  claim 19 , said substrate being a surface of a vehicle or vehicle accessory. 
   
   
       26 . The method according to  claim 19 , said substrate being pre-painted prior to application of said decal. 
   
   
       27 . The method according to  claim 19 , said substrate being a flat surface. 
   
   
       28 . The method according to  claim 27 , further comprising:
 (e) bending, stamping or otherwise shaping said substrate surface after application of said decal thereby causing said ink transfer coating to stretch and elongate without cracking.   
   
   
       29 . The method according to  claim 19 , said surface being a contoured surface. 
   
   
       30 . The method according to  claim 29 , further comprising:
 (f) stretching said decal over said contoured surface after removing said backing sheet without wrinkling or damaging the decal.