Process for the reduction of diene polymer hot melt adhesive color (II)

Abstract

A method of reducing the color of a hot melt adhesive formulation comprising a coupled polymer of a conjugated diene which comprises adding to the formulation an amount of 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine sufficient to reduce color formation. This method is especially effective for epoxy resin coupled polymers and sequentially polymerized polymers.

I claim: 
     
       1. A method of reducing the color of a hot melt adhesive formulation comprising a coupled polymer of a conjugated diene which comprises adding to the formulation an amount of 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine sufficient to reduce color formation. 
     
     
       2. The method of claim 1 wherein the concentration of 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine is at least 0.2 parts per hundred rubber. 
     
     
       3. The method of claim 1 wherein the polymer is a block copolymer of a conjugated diene and a vinyl aromatic hydrocarbon. 
     
     
       4. The method of claim 1 wherein the polymer is coupled with an epoxy resin. 
     
     
       5. The product of the method of claim 1. 
     
     
       6. The product of the method of claim 2. 
     
     
       7. The product of the method of claim 3. 
     
     
       8. The product of the method of claim 4.