Dynamic vulcanization of polyurethane elastomeric material in the presence of thermoplastics

Abstract

A thermoplastically processable cured rubber composition comprises a crosslinked or cured urethane polymer dispersed in a matrix made of a thermoplastic polymeric material. In one aspect, the matrix forms a continuous phase and the crosslinked urethane polymer is in the form of particles forming a non-continuous phase. The processable rubber compositions can be made by a process of dynamic vulcanization of a urethane prepolymer material in the presence of the thermoplastic matrix material. The process involves combining a urethane prepolymer, a curing agent capable of reacting with the urethane prepolymer, and a thermoplastic material to form a mixture, and heating the mixture at a temperature and for a time sufficient to effect reaction between the curing agent and the prepolymer. Mechanical energy is supplied to the mixture during the heating step so that the crosslinking or curing of the urethane prepolymer occurs while the prepolymer and thermoplastic are undergoing a mixing.

1 . A thermoplastically processable cured rubber composition prepared by dynamic vulcanization of a liquid urethane prepolymer material in the presence of a thermoplastic polymeric material and at least one curing agent, the composition comprising a crosslinked urethane polymer dispersed in a matrix, the matrix comprising the thermoplastic polymeric material.  
   
   
       2 . A processable rubber composition according to  claim 1 , wherein the composition may be processed into an article with a tensile strength that exceeds the tensile strength of the thermoplastic polymeric material.  
   
   
       3 . A composition according to  claim 1 , wherein the matrix forms a continuous phase.  
   
   
       4 . A composition according to  claim 1 , wherein the crosslinked urethane polymer is in the form of particles forming a non-continuous phase.  
   
   
       5 . A composition according to  claim 1 , wherein the crosslinked urethane polymer and the matrix form co-continuous phases.  
   
   
       6 . A composition according to  claim 1 , wherein the urethane polymer comprises a polymer of a polyisocyanate and a polyester polyol.  
   
   
       7 . A composition according to  claim 6 , wherein the polyester polyol is a lactone polymer.  
   
   
       8 . A composition according to  claim 6 , wherein the polyester polyol is a polymer of a diacid component and a diol component.  
   
   
       9 . A composition according to  claim 6 , wherein the polyisocyanate is selected from the group consisting of naphthalene diisocyanate, methylene phenyl diisocyanate, toluene diisocyanate, and bitolylene diisocyanate.  
   
   
       10 . A composition according to  claim 1 , wherein the urethane polymer comprises a polymer of a polyisocyanate and a polycarbonate polyol.  
   
   
       11 . A composition according to  claim 1 , wherein the crosslinked urethane polymer is the reaction product of a isocyanate functional urethane prepolymer and a polyol of functionality greater than 2.  
   
   
       12 . A composition according to  claim 1 , wherein the crosslinked urethane polymer is the reaction product of an isocyanate functional urethane prepolymer and a polyol of functionality of about 2.  
   
   
       13 . A composition according to  claim 1 , wherein the crosslinked urethane polymer is the reaction product of a hydroxyl functional urethane prepolymer and a polyisocyanate.  
   
   
       14 . A composition according to  claim 1 , wherein the crosslinked urethane polymer is the reaction product of a hydroxyl functional urethane prepolymer and a peroxide curing agent.  
   
   
       15 . A composition according to  claim 1 , wherein the crosslinked urethane polymer is a cast urethane elastomer.  
   
   
       16 . A composition according to  claim 1 , wherein the crosslinked urethane polymer is a thermoplastic polyurethane.  
   
   
       17 . A composition according to  claim 1 , wherein the crosslinked urethane polymer is a cured millable gum.  
   
   
       18 - 27 . (canceled)  
   
   
       28 . A method according to claim  27 , wherein the prepolymer is a solid, the method comprising inserting the thermoplastic material and prepolymer into the screw extruder together using a first feeder, and adding the curative agent with a side feeder at a second feeder downstream of the first feeder.  
   
   
       29 . (canceled)  
   
   
       30 . A shaped elastomeric article comprising a thermoplastically processable cured rubber composition prepared by dynamic vulcanization of a liquid urethane prepolymer material in the presence of a thermoplastic polymeric material and at least one curing agent, the composition comprising a crosslinked urethane polymer dispersed in a matrix, wherein the matrix comprises the thermoplastic polymeric material.  
   
   
       31 . An article according to  claim 30 , wherein the thermoplastic polymeric material comprises a thermoplastic elastomer.  
   
   
       32 . An article according to  claim 31 , wherein the thermoplastic elastomer comprises a (A-B) n -type polymer with blocks of polyamide and blocks of polyether.  
   
   
       33 . An article according to  claim 31 , wherein the thermoplastic elastomer comprises a (A-B) n -type polymer with blocks of polyester and polyether.  
   
   
       34 . An article according to  claim 30 , wherein the thermoplastic material comprises an amorphous polymeric material.  
   
   
       35 . An article according to  claim 30 , wherein the Tg of the amorphous polymeric material is 150° C. or greater.  
   
   
       36 . An article according to  claim 30 , wherein the thermoplastic material comprises a semi-crystalline polymeric material.  
   
   
       37 . An article according to  claim 36 , wherein the melting point of the semi-crystalline polymeric material is 150° C. or greater.  
   
   
       38 . An article according to  claim 30 , wherein the thermoplastic material comprises a polyamide.  
   
   
       39 . An article according to  claim 30 , wherein the thermoplastic material comprises a polyester.  
   
   
       40 . An article according to  claim 30 , wherein the crosslinked urethane polymer is a polymer of bitolyene diisocyanate and a polylactone diol.  
   
   
       41 . An article according to  claim 30 , wherein the crosslinked urethane polymer is a peroxide cured polymer of methylene phenyl diisocyanate and a polyester diol.  
   
   
       42 . An article according to  claim 30 , wherein the crosslinked urethane polymer is a polymer of bitolyene diisocyanate and a polycarbonate diol.  
   
   
       43 . A seal according to  claim 30 .  
   
   
       44 . An O-ring according to  claim 30   
   
   
       45 . A gasket according to  claim 30 .  
   
   
       46 . A method for reducing costs of a manufacturing process for making shaped rubber articles from a processable rubber composition, comprising recycling scrap material generated during the manufacturing process to make new shaped articles comprising the processable rubber composition, 
 wherein the processable rubber composition is the product of dynamic vulcanization of a urethane prepolymer in the presence of a thermoplastic material.    
   
   
       47 . A method according to  claim 46 , wherein the manufacturing process comprises forming the shaped articles by a thermoplastic processing technique.  
   
   
       48 . A method according to  claim 47 , wherein the thermoplastic processing technique is selected from the group consisting of blow molding, injection molding, compression molding, and extrusion.