Polyurethane composition containing a property-enhancing agent

Abstract

A composition comprising at least a part A and a part B is disclosed. The part A comprises at least one polyol and the part B comprises at least one isocyanate. At least one part further comprises at least one of the following: a strength enhancer having a softening point of from about 120° F. to about 400° F.; a non-reactive hydrophobic enhancer; and/or an impact absorption enhancer. These enhancers provide, among optional other benefits, enhanced pull strength. Additionally, a mass can be prepared by a method of combining part A with part B and applying the mixture to a void. The compositions may also be used in the repair of surface defects or for the reinforcement of structural members such as spike holes left after spike removal from railroad ties during road bed maintenance or repair.

1 . A composition comprising at least a part A and a part B, 
 the part A comprising at least one polyol and at least one thixotropic gelling agent; and    the part B comprising at least one isocyanate,    wherein at least one part further comprises at least one impact absorption enhancer.    
   
   
       2 . The composition according to  claim 1 , wherein the impact absorption enhancer is present in an amount of from about 1% to about 30% by weight of the part.  
   
   
       3 . The composition according to  claim 1 , wherein the impact absorption enhancer comprises PVC.  
   
   
       4 . The composition according to  claim 3 , wherein the part B comprises the impact absorption enhancer.  
   
   
       5 . The composition of  claim 1 , further comprising a blowing agent, wherein the composition is foamable.  
   
   
       6 . The composition according to  claim 1 , wherein the impact absorption enhancer is present in an amount of from about 5% to about 30% by weight of the part.  
   
   
       7 . The composition according to  claim 1  wherein the composition exhibits a pull strength of at least about 1400 pounds according to Pull Strength Test Method A.  
   
   
       8 . The composition according to  claim 1 , wherein the impact absorption enhancer has a viscosity of at least about 100,000 centipoises.  
   
   
       9 . A composition comprising at least a part A and a part B, 
 the part A comprising at least one polyol, and    the part B comprising at least one isocyanate,    wherein a ratio of active hydrogen atoms in part A to isocyanate group in part B is from about 1:0.9 to about 1:4, and wherein at least one part further comprises at least one impact absorption enhancer.    
   
   
       10 . The composition according to  claim 9 , wherein the impact absorption enhancer is present in an amount of from about 1% to about 30% by weight of the part.  
   
   
       11 . The composition according to  claim 9 , wherein the impact absorption enhancer comprises PVC.  
   
   
       12 . The composition according to  claim 9 , wherein the part B comprises the impact absorption enhancer.  
   
   
       13 . The composition according to  claim 9 , wherein the ratio of active hydrogen atoms in part A to isocyanate group in part B being from about 1:1 to about 1:2  
   
   
       14 . A method of repair or reinforcement of a structural member subject to routine vibrations comprising the steps of: 
 a) providing a structural member having a void;    b) providing a mixture of the composition of  claim 1;  and    c) applying the mixture to the void creating a filled area.    
   
   
       15 . The method of  claim 14 , wherein the structural member is a railroad tie.  
   
   
       16 . A method of improving pull strength and impact absorption of a railroad tie comprising the steps of: 
 a) providing the railroad tie having a void;    b) providing a mixture of the composition of  claim 1;  and    c) applying the mixture to the void creating a filled area.    
   
   
       17 . The method according to  claim 16 , further comprising a step of nailing a spike into at least a portion of the filled area.  
   
   
       18 . A railroad tie comprising a composition of  claim 1 .  
   
   
       19 . A railroad tie comprising a composition of  claim 9.