Oiled polymer and process for the production thereof

Abstract

Oiled SIS polymers and processes for their production are disclosed. These processes result in advantages including reduced mixing time and less shear degradation. An adhesive composition comprising the oiled polymer of the invention is also disclosed.

That which is claimed is: 
     
       1. An oiled polymer comprising a styrene-isoprene-styrene block copolymer and from about 5 to 50 parts of oil. 
     
     
       2. A polymer as in claim 1 wherein said oil is selected from the group consisting of mineral oils, naphthenic oils, paraffinic oils, and low softening point tackifying resins. 
     
     
       3. A polymer as in claim 1 wherein said oil is a naphthenic oil. 
     
     
       4. A polymer as in claim 3 wherein said naphthenic oil is one with a low aromatic content. 
     
     
       5. A polymer as in claim 1 wherein said oil is present in an amount of from 10 to 30 parts. 
     
     
       6. A process for preparing the oiled polymer of claim 1 comprising the steps of: (a) polymerizing neat SIS block copolymer in a solvent;   (b) adding from about 5 to 50 parts of oil to (a) and to form the oiled polymer;   (c) removing the solvent from the oiled polymer.   
     
     
       7. A process for preparing the oiled polymer of claim 1 comprising the steps of: (a) premixing oil and neat SIS copolymer to form a premixed oiled polymer; and   (b) metering the product of (a) into a continuous or batch mixer for compounding.   
     
     
       8. A process for preparing the oiled polymer of claim 1 comprising separately adding oil and neat SIS copolymer into a batch or continuous mixer. 
     
     
       9. An adhesive composition comprising the oiled polymer of claim 1 and at least one tackifying resin. 
     
     
       10. A composition as in claim 9 further comprising predetermined additional amounts of oil. 
     
     
       11. A polymer as in claim 1 wherein said styrene-isoprene block copolymer is present in an amount of from about 14-32 wt %. 
     
     
       12. A polymer as in claim 11 wherein said styrene-isoprene block copolymer is about 15 wt %. 
     
     
       13. A polymer as in claim 11 wherein said styrene-isoprene block copolymer is about 21 wt %. 
     
     
       14. A polymer as in claim 11 wherein said styrene-isoprene block copolymer is about 30 wt %.