Pneumatic tire and innerliner and method for manufacture

Abstract

A pneumatic tire and an innerliner for use in a pneumatic tire are provided by the invention. The innerliner comprises a multilayer structure including a barrier layer and an adhesive layer. The barrier is a blend of high chlorine content chlorinated polyethylene elastomer and low chlorine-content chlorinated polyethylene elastomer. The adhesive can include a nitrile rubber composition or an ultra high molecular weight elastomer. The present invention more specifically discloses a pneumatic tire comprising a carcass and an innerliner, said innerliner comprising a multilayer structure including a barrier layer and an adhesive layer, the barrier layer comprising a blend of high chlorine content chlorinated polyethylene elastomer and low chlorine content chlorinated polyethylene elastomer, the high chlorine content chlorinated polyethylene elastomer having a chlorine content of between about 35 percent to about 45 percent and the low chlorine content chlorinated polyethylene polymer having a chlorine content of between about 25 percent to about 35 percent, wherein the high chlorine content polyethylene has a chlorine content which is at least 5 percentage points higher that the chlorine content of the low chlorine content polyethylene; the adhesive layer comprising a polymer composition for adhering the barrier layer to said rubber carcass; and wherein the innerliner provides an oxygen permeability of less than 250 cc-mil/100 in 2 -atm-day at 65° C. and good cold flexibility at −40° C.

What is claimed is:  
     
       1. A pneumatic tire comprising a carcass and an innerliner, said innerliner comprising a multilayer structure including a barrier layer and an adhesive layer, 
       the barrier layer comprising a blend of high chlorine content chlorinated polyethylene elastomer and low chlorine content chlorinated polyethylene elastomer, the high chlorine content chlorinated polyethylene elastomer having a chlorine content of between about 35 percent to about 45 percent and the low chlorine content chlorinated polyethylene elastomer having a chlorine content of between about 25 percent to about 35 percent, wherein the high chlorine content polyethylene elastomer has a chlorine content which is at least 5 percentage points higher than the chlorine content of the low chlorine content polyethylene elastomer, and wherein the barrier layer has an average chlorine content of about 30 percent to about 35 percent;  
       the adhesive layer comprising a polymer composition for adhering the barrier layer to said rubber carcass; and  
       wherein the carcass and the innerliner are cured, and the innerliner provides an oxygen permeability of less than 250 cc-mil/100 in 2 -atm-day at 65° C. and good cold flexibility at −40° C.  
     
     
       2. The pneumatic tire according to  claim 1  wherein the low chlorine content chlorinated polyethylene elastomer and the high chlorine content chlorinated polyethylene are provided in a ratio of between about 5:1 to about 1.5:1, respectively. 
     
     
       3. The pneumatic tire according to  claim 1  wherein the low chlorine content chlorinated polyethylene elastomer has a chlorine content in the range of about 28 percent to about 32 percent. 
     
     
       4. The pneumatic tire according to  claim 1  wherein the high chlorine content chlorinated polyethylene elastomer has a chlorine content in the range of about 38 percent to about 43 percent. 
     
     
       5. The pneumatic tire according to  claim 1  wherein said carcass comprises a SBR/NR blend. 
     
     
       6. The pneumatic tire according to  claim 1  wherein the adhesive layer comprises ultra high molecular weight polyethylene having a weight average molecular weight of at least about 500,000. 
     
     
       7. The pneumatic tire according to  claim 1  wherein the adhesive layer comprises nitrile rubber. 
     
     
       8. A pneumatic tire according to  claim 7  wherein the nitrile rubber has an acrylonitrile content which is within the range of about 16 percent to about 27 percent. 
     
     
       9. A pneumatic tire according to  claim 6  wherein the ultra high molecular weight polyethylene has a weight average molecular weight of at least 1,000,000. 
     
     
       10. The pneumatic tire according to  claim 1  wherein the low chlorine content chlorinated polyethylene elastomer and the high chlorine content chlorinated polyethylene are provided in a ratio of between about 3:1 to about 2:1, respectively. 
     
     
       11. The pneumatic tire according to  claim 1  wherein the high chlorine content polyethylene has a chlorine content which is at least 10 percentage points higher that the chlorine content of the low chlorine content polyethylene. 
     
     
       12. The pneumatic tire according to  claim 1  wherein the low chlorine content chlorinated polyethylene elastomer has a chlorine content in the range of about 28 percent to about 32 percent; and wherein the high chlorine content chlorinated polyethylene elastomer has a chlorine content in the range of about 38 percent to about 43 percent. 
     
     
       13. The pneumatic tire according to  claim 12  wherein the high chlorine content polyethylene has a chlorine content which is at least 10 percentage points higher that the chlorine content of the low chlorine content polyethylene. 
     
     
       14. The pneumatic tire according to  claim 1 , wherein the carcass and innerliner are cured at a temperature of between about 100° C. and 200° C. 
     
     
       15. The pneumatic tire according to  claim 1 , wherein the carcass and the innerliner are cured at a temperature of between about 110 C. and 180° C. 
     
     
       16. The pneumatic tire according to  claim 1 , wherein the innerliner has a thickness of between about 8 mils to about 130 mils. 
     
     
       17. The pneumatic tire according to  claim 1 , wherein the innerliner has a thickness of between about 15 mils and about 60 mils. 
     
     
       18. The pneumatic tire according to  claim 1 , wherein the innerliner is vulcanized in the presence of a sulfur vulcanizing agent. 
     
     
       19. The pneumatic tire according to  claim 1 , wherein the innerliner comprises an accelerator comprising amines, disulfides. guanidines, thioureas, thiazoles, thiurams, sulfonamides, dithiocarbamate, xanthates, and mixtures thereof. 
     
     
       20. The pneumatic tire according to  claim 1 , wherein the innerliner and the carcass are sulfur cocured. 
     
     
       21. The pneumatic tire according to  claim 1 , wherein the innerliner is calendered prior to attachment to the carcass. 
     
     
       22. A pneumatic tire according to  claim 1 , wherein the barrier layer has an average chlorine content of about 30 percent to less than 35 percent.