Rubber formulation with adhesive-compatible surface

Abstract

A method of effecting an improved adhesive bond between a rubber surface and a device adhered thereto is disclosed. In pneumatic tires, monitoring devices are more securely adhered to the innerliner of the tire utilizing a room temperature vulcanizable adhesive wherein curing is facilitated in the presence of moisture. The innerliner formulation is prepared by incorporating a material which has incomplete compatibility with the rubber of the innerliner formulation, and which has hygroscopic properties which thereby tends to attract moisture.

1 . a method of effecting an adhesive bond between a rubber surface of a rubber material and an adhesive composition comprising: 
 incorporating into a formulation for producing the rubber material an additive material having a solubility parameter of 8.5 to 10.5 cal 1/2  cm 3/2  mol −1 , the additive material further having hygroscopic properties; and    contacting the rubber surface with an adhesive which is vulcanizable at room temperature in the presence of moisture.    
   
   
       2 . The method of  claim 1  wherein the adhesive is selected from the group consisting of a urethane adhesive with silane type end groups, a hydroxyl terminated organosiloxane adhesive, and mixtures thereof.  
   
   
       3 . The method of  claim 1  wherein the rubber material is an innerliner for a pneumatic tire.  
   
   
       4 . The method of  claim 1  wherein the rubber material is a strip applied to an innerliner for a pneumatic tire.  
   
   
       5 . The method of  claim 1  wherein the formulation comprises a rubber selected from the group consisting of homopolymers and copolymers of at least one of isoprene and 1,3-butadiene and copolymers of at least one of isoprene and 1,3-butadiene with styrene; and isobutylene-based rubbers as copolymers of isobutylene and from about 2 to about 8 weight percent units derived from isoprene and such isobutylene-based copolymers halogenated with chlorine or bromine; and mixtures thereof.  
   
   
       6 . The method of  claim 1  wherein the additive material contains end groups selected from the group consisting of —OH, —OOH, —NH, —NH 2 , and mixtures thereof.  
   
   
       7 . The method of  claim 1  wherein a microprocessor, an antenna, or both is positioned onto the adhesive opposite an area of contact between the adhesive and the rubber surface.  
   
   
       8 . The method of  claim 2  wherein the adhesive is a hydroxyl terminated organosiloxane adhesive.  
   
   
       9 . The method of  claim 1  wherein the additive material is sorbitan monostearate.  
   
   
       10 . The method of  claim 1  wherein the additive material is octylphenol formaldehyde resin.  
   
   
       11 . A method of increasing moisture on a rubber surface of a rubber material comprising: 
 incorporating into a formulation for producing the rubber material an additive material having a solubility parameter of 8.5 to 10.5 cal 1/2  cm 3/2  mol −1 , further wherein the additive material has hygroscopic properties.    
   
   
       12 . The method of  claim 11  wherein the rubber material is an innerliner for a pneumatic tire.  
   
   
       13 . The method of  claim 11  wherein the additive material is sorbitan monostearate.  
   
   
       14 . The method of  claim 11  wherein the additive material is octylphenol formaldehyde resin.  
   
   
       15 . The method of  claim 11  wherein the formulation comprises a rubber selected from the group consisting of homopolymers and copolymers of at least one of isoprene and 1,3-butadiene and copolymers of at least one of isoprene and 1,3-butadiene with styrene; and isobutylene-based rubbers as copolymers of isobutylene and from about 2 to about 8 weight percent units derived from isoprene and such isobutylene-based copolymers halogenated with chlorine or bromine; and mixtures thereof.  
   
   
       16 . A rubber composition comprising: 
 a rubber selected from the group consisting of homopolymers and copolymers of at least one of isoprene and 1,3-butadiene and copolymers of at least one of isoprene and 1,3-butadiene with styrene; and isobutylene-based based rubbers as copolymers of isobutylene and from about 2 to about 8 weight percent units derived from isoprene and such isobutylene-based copolymers halogenated with chlorine or bromine; and mixtures thereof; and    an additive material having a solubility parameter of 8.5 to 10.5 cal 1/2  cm 3/2  mol −1 , further wherein the material has hygroscopic properties.    
   
   
       17 . The rubber composition of  claim 16  wherein the additive material is sorbitan monostearate.  
   
   
       18 . The rubber composition of  claim 16  wherein the additive material is octylphenol formaldehyde resin.  
   
   
       19 . The rubber composition of  claim 16  wherein the additive material is incorporated into the rubber composition at a concentration of 0.5 to 6.0 parts per hundred rubber.  
   
   
       20 . A pneumatic tire comprising the rubber composition of  claim 16.