Process for forming durable layer for in-mold decoration

Abstract

The present invention is directed to a process for forming a durable layer on an article in an in-mold decoration process. The process comprises the steps of: a) thermally curing a composition comprising (i) an amino crosslinker and (ii) a UV curable monomer or oligomer having at least one functional group reactive with the amino crosslinker, in the presence of an acid catalyst to form a durable layer; b) transferring the durable layer to the surface of an article formed by an injection molding process carried out in a mold; and c) curing the durable layer by radiation.

1 . A process for forming a durable layer on an article in an in-mold decoration process, comprising the steps of: 
 a) thermally curing a composition comprising (i) an amino crosslinker and (ii) a UV curable monomer or oligomer having at least one functional group reactive with the amino crosslinker, in the presence of an acid catalyst to form a durable layer;    b) transferring said durable layer to the surface of an article formed by an injection molding process carried out in a mold; and    c) curing the durable layer by radiation.    
   
   
       2 . The process of  claim 1 , wherein said amino crosslinker is an amine-aldehyde condensate or a carboxyl modified amino resin.  
   
   
       3 . The process of  claim 2 , wherein said amine-aldehyde condensate is a formaldehyde condensate of a multifunctional amine.  
   
   
       4 . The process of  claim 3 , wherein said multifunctional amine is melamine or urea.  
   
   
       5 . The process of  claim 1 , wherein said amino crosslinker is melamine-formaldehyde, benzoguanamine-aldehyde, or glycoluril-formaldehyde.  
   
   
       6 . The process of  claim 1 , wherein said functional group in said UV curable monomer or oligomer is hydroxyl, carboxyl, thiol, amine, amide or urethane.  
   
   
       7 . The process of  claim 1 , wherein said UV curable monomer or oligomer comprises an UV crosslinkable functionality selected from the group consisting of acrylate, methacrylate, allyl, vinyl ether, epoxide, and a combination thereof.  
   
   
       8 . The process of  claim 1 , wherein said UV curable monomer or oligomer is hydroxyalkyl acrylate, hydroxyalkyl methacrylate, hydroxyl epoxide, carboxyl acrylate, or carboxyl methacrylate.  
   
   
       9 . The process of  claim 1 , wherein said UV curable monomer or oligomer is 4-hydroxybutyl acrylate, hydroxyethylacrylate, or hydroxypropyl acrylate.  
   
   
       10 . The process of  claim 1 , wherein said composition further comprises a photoinitiator.  
   
   
       11 . The process of  claim 1 , wherein said acid catalyst is p-toluenesulfonic acid, a phosphoric acid derivative, dodecylbenzene sulfonic acid, or dinonyl naphthalene disulfonic acid.  
   
   
       12 . The process of  claim 10 , wherein said photoinitiator is Norrish Type 1, Type 2 or Type 3 photoinitiator.  
   
   
       13 . The process of  claim 1 , wherein said composition further comprises an antioxidant.  
   
   
       14 . The process of  claim 13 , wherein said composition further comprises a multifunctional polymer or a multifunctional oligomer reactive with said amino crosslinker.  
   
   
       15 . The process of  claim 13 , wherein said composition further comprises a binder.  
   
   
       16 . The process of  claim 13 , wherein said composition further comprises an adhesion promoter.