Low color, aromatic modified C5 hydrocaron resins

Abstract

Low color, aromatic modified C 5 hydrocarbon resins are disclosed. The resins are predominantly an aromatic modified piperylene resin. The resins are useful as tackifies in hot melt adhesives and hot melt pressure sensitive adhesives.

We claim:  
     
         1 . A process for making a hydrocarbon copolymer resin having a Gardner color of less than about 4 and having a ring and ball softening point from about 85 to about 100° C. comprising: 
 (a) providing a first predominantly C 5  hydrocarbon stream containing unsaturated aliphatic monomers, said unsaturated aliphatic monomers comprising a combination of piperylene monomers, less than about 2% weight cyclopentadiene and dicyclopentadiene monomers and less than about 1% weight isoprene;  
 (b) providing a second hydrocarbon stream comprising a monovinyl aromatic C 5  to C 12  monomer;  
 (c) combining said streams to obtain a weight ratio of said unsaturated aliphatic monomers to said monovinyl aromatic C 8  to C 12  monomers from about 1.5/1 to about 25/1;  
 (d) polymerizing said combined streams at a temperature from about 25 to about 75° C.; and  
 (e) recovering said copolymer resin.  
 
     
     
         2 . The process of  claim 1  wherein said unsaturated aliphatic monomer further includes a C 4  to C 5  isoolefin.  
     
     
         3 . The process of  claim 1  wherein said combining of said streams is at a weight ratio of said unsaturated aliphatic monomers to said monovinyl aromatic C 8  to C 12  monomers from about 23/1 to about 25/1, and further wherein said copolymer resin, a ring and ball softening point from about 90° to 100° C.  
     
     
         4 . The process of  claim 3  wherein said copolymer resin has a Mz from about 2500 to about 4000 daltons and a polydispersity of about 1.7 to about 2.0.  
     
     
         5 . The process of  claim 1  wherein said combining of said streams is at a weight ratio of said unsaturated aliphatic monomers to said monovinyl aromatic C 8  to C 12  monomers from about 3/1 to about 5/1, and further wherein said copolymer resin, a ring and ball softening point from about 850 to 95° C.  
     
     
         6 . The process of  claim 5  wherein said copolymer resin has a Mz from about 2700 to about 4000 daltons and a polydispersity of about 1.7 to about 2.0.  
     
     
         7 . The process of  claim 1  wherein said combining of said streams is at a weight ratio of said unsaturated aliphatic monomers to said monovinyl aromatic C 8  to C 12  monomers from about 1.5/1 to about 2.5/1, and further wherein said copolymer resin, a ring and ball softening point from about 850 to 95° C.  
     
     
         8 . The process of  claim 7  wherein said copolymer resin has a Mz from about 2000 to about 3800 daltons and a polydispersity of about 1.7 to about 2.0.  
     
     
         9 . The process of  claim 2  wherein said isoolefin is isobutylene.  
     
     
         10 . The process of  claim 9  wherein said isobutylene is provided in a third stream, said third stream being substantially free of said monomers.  
     
     
         11 . The process of  claim 10  wherein said third stream contains at least 99% weight of said isobutylene.  
     
     
         12 . The process of  claim 1 , wherein said monovinyl aromatic C 8  to C 12  monomer is α-methylstyrene.  
     
     
         13 . The process of  claim 12  wherein said third stream contains at least 99% weight of said α-methylstyrene.  
     
     
         14 . The process of  claim 1  further including the step of providing from about 1 to about 4% weight of a Friedel-Crafts catalyst for cationically polymerizing said streams.  
     
     
         15 . The process of  claim 14  wherein said Friedel-Crafts catalyst is liquefied AlCl 3 /H 2 O/trimethylbenzene complex.  
     
     
         16 . The process of  claim 15  wherein said complex has a mole ratio of AlCl 3  to H 2 O from about 3/1 to about 7/1 and a mole ratio of trimethylbenzene to H 2 O from about 3/1 to about 7/1.  
     
     
         17 . A tackifier made by the process of  claim 1 .  
     
     
         18 . A hydrocarbon copolymer resin comprising a reaction product of: 
 (a) a first predominantly C 5  hydrocarbon stream containing unsaturated aliphatic monomers, said unsaturated aliphatic monomers comprising a combination of piperylene monomers, less than about 2% weight cyclopentadiene and dicyclopentadiene monomers and less than about 1% weight isoprene; and    (b) a second hydrocarbon stream comprising a monovinyl aromatic C 8  to C 12  monomer;    wherein a weight ratio of said unsaturated aliphatic monomers to said monovinyl aromatic C 8  to C 12  monomers is from about 1.5/1 to about 6/1 to yield said resin having a Gardner color of less than about 4 and having a ring and ball softening point from about 85 to about 100° C.    
     
     
         19 . The resin of  claim 18  wherein said resin has a Mz from about 2000 to 4000 and a polydispersity of about 1.7 to about 2.0.  
     
     
         20 . The resin of  claim 18  wherein said monovinyl aromatic C 8  to C 12  monomer is α-methylstyrene.  
     
     
         21 . The resin of  claim 18  further comprising from about 0 to about 15 weight percent of an isoolefin monomer, wherein said isoolefin monomer is selected from the group consisting of isobutylene, isoamylene and combinations thereof and further wherein said isoolefin monomer is included as said unsaturated aliphatic monomers in said weight ratio.  
     
     
         22 . A hydrocarbon copolymer resin comprising a reaction product of: 
 (a) a first predominantly C 5  hydrocarbon stream containing unsaturated aliphatic monomers, said unsaturated aliphatic monomers comprising a combination of piperylene monomers, less than about 2% weight cyclopentadiene and dicyclopentadiene monomers and less than about 1% weight isoprene; and    (b) a second hydrocarbon stream comprising a monovinyl aromatic C 8  to C 12  monomer;    wherein a weight ratio of said unsaturated aliphatic monomers to said monovinyl aromatic C 8  to C 12  monomers is from about 15/1 to about 50/1 to yield said resin having a Gardner color of less than about 4 and having a ring and ball softening point from about 85 to about 100° C.    
     
     
         23 . The resin of  claim 22  wherein said resin has a Mz from about 2500 to 4000 and a polydispersity of about 1.7 to about 2.0.  
     
     
         24 . The resin of  claim 22  wherein said monovinyl aromatic C 8  to C 1 2  monomer is α-methylstyrene.  
     
     
         25 . The resin of  claim 22  further comprising from about 15 to about 25 weight percent of an isoolefin monomer, wherein said isoolefin monomer is selected from the group consisting of isobutylene, isoamylene and combinations thereof and further wherein said isoolefin monomer is included as said unsaturated aliphatic monomers in said weight ratio.