Composition for release layer of in-mold decoration

Abstract

This invention relates to a composition suitable for the formation of a release layer in an in-mold decoration or thermal transfer printing process.

1 . A release layer composition for in-mold decoration which comprises a copolymer or interpenetration network formed from a composition comprising 
 (i) an amine-aldehyde condensate; and    (ii) a radical inhibitor or quencher.    
   
   
       2 . The composition of  claim 1  wherein said amine-aldehyde condensate is a formaldehyde condensate of a multifunctional amine.  
   
   
       3 . The composition of  claim 2  wherein said multifunctional amine is melamine or urea.  
   
   
       4 . The composition of  claim 1  wherein said amine-formaldehyde condensate in the dried release layer ranges from about 40% to about 95% by weight.  
   
   
       5 . The composition of  claim 1  wherein said radical inhibitor or quencher is selected from the group consisting of phenols, phenolic resins or precondensates thereof, oximes, hindered amine oxides, nitrosobenzenes and oxidized derivatives or metal complexes thereof.  
   
   
       6 . The composition of  claim 5  wherein said phenol and phenolic resin or a precondensate thereof is selected from the group consisting of phenol, methoxyphenol, cresol, phenol formaldehyde resins, novolacs, resoles, resorcinol, salicylates, hydroxyl salicylates, trihydroxybenzene and analogs, derivatives or oxidized products thereof.  
   
   
       7 . The composition of  claim 1  wherein said radical inhibitor or quencher is a polyphenol.  
   
   
       8 . The composition of  claim 5  wherein said hindered amine oxide is TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy), 4-hydroxy TEMPO or 4-oxo-TEMPO.  
   
   
       9 . The composition of  claim 1  wherein said radical inhibitor or quencher in the dried release layer ranges about 1% to about 60% by weight.  
   
   
       10 . The composition of  claim 1  further comprising a catalyst.  
   
   
       11 . The composition of  claim 10  wherein said catalyst is sulfiric acid, toluene sulfonic acid, dodecylsulfonic acid, dodecylbenzenesulfonic acid, hydrochloric acid, phosphoric acid, HBF 4 , HPF 6 , HSbF 6 , HAsF 6  or a salt thereof with a fugitive base.  
   
   
       12 . The composition of  claim 1  further comprising a crosslinking agent.  
   
   
       13 . The composition of  claim 12  wherein said crosslinking agent is formaldehyde, glyoxal, succinaldehyde, hexamethylene tetramine, phenolics, malonate blocked isocyanates, polyols, carbamate functionalized polymers, amine functionalized polymers or amide functionalized polymers.  
   
   
       14 . The composition of  claim 1  further comprising a UV absorbing moiety.  
   
   
       15 . The composition of  claim 14  wherein said UV absorbing moiety is o-hydroxy benzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, o-hydroxyphenyl-triazine, salicylates, α-cyano-β-phenyl-cinnamates, hydroxyphenyl benzotriazole or benzoxazinone.  
   
   
       16 . The composition of  claim 1  further comprising a silicone resin.  
   
   
       17 . The composition of  claim 16  wherein said silicone resin is a silicone block or graft copolymer or a silicone polymer having at least one reactive functional group.  
   
   
       18 . The composition of  claim 1  further comprising an additive.  
   
   
       19 . The composition of  claim 1  which is dispersed or dissolved in a solvent.  
   
   
       20 . The composition of  claim 19  wherein said solvent is selected from the group consisting of ketones, esters, ethers, glycol ethers, glycolether esters, and pyrrolidones.  
   
   
       21 . A release layer for in-mold decoration which comprises a copolymer or IPN formed from a composition comprising 
 (i) an amine-aldehyde condensate, and    (ii) a radical inhibitor or quencher.    
   
   
       22 . The release layer of  claim 21  wherein said composition further comprising one or more of the following: a catalyst, a crosslinking agent, a UV absorbing moiety, a silicone resin or an additive.  
   
   
       23 . A plastic article having a release layer formed from a composition comprising 
 (i) an amine-aldehyde condensate, and    (ii) a radical inhibitor or quencher.    
   
   
       24 . The article of  claim 23  which is a plastic cover of a cell phone or pager, a personal accessory, toy or educational device, plastic cover of a personal digital assistant or e-book, credit or smart card, identification or business card, face of an album, watch, clock, radio or camera, dashboard in an automobile, household item, laptop computer housing or carrying case, front control panel of a consumer electronic equipment, a thermal transfer protective coating of identification, passport, inkjet printed or thermal printed image.  
   
   
       25 . A decorative tape or strip for in-mold decoration, which tape or strip comprises 
 a) a carrier layer;    b) a release layer formed from a composition comprising 
 (i) an amine-aldehyde condensate, and  
 (ii) a radical inhibitor or quencher;  
   c) a durable layer;    d) a decorative layer; and    e) an adhesive layer.    
   
   
       26 . The decorative tape or strip of  claim 25  wherein said decorative layer is a metallic layer or an ink layer.  
   
   
       27 . A process for the formation of a release layer, which process comprises: 
 dispersing or dissolving a composition comprising (i) an amine-aldehyde condensate and (ii) a radical inhibitor or quencher and a solvent; and    curing said composition.    
   
   
       28 . The process of  claim 27  further comprising a thermal or photo-oxidation step to oxidize the radical inhibitor or quencher to improve the UV screening efficiency of the release layer.