Hybrid systems consisting of foamed thermoplastic elastomers and polyurethanes

Abstract

A hybrid material contains a matrix of polyurethane and foamed particles of thermoplastic polyurethane contained therein. A process can be used for producing such hybrid materials and these hybrid materials can be used as bicycle saddles, upholstery and shoe soles.

1 . (canceled) 
     
     
         2 : A saddle comprising a hybrid material,
 wherein the hybrid material comprises a matrix of polyurethane and foamed particles of thermoplastic polyurethane comprised therein,   wherein the foamed particles have a closed surface skin.   
     
     
         3 : The saddle according to  claim 2 , wherein the foamed particles have a diameter of from 0.1 mm to 10 cm and are spherical or ellipsoidal. 
     
     
         4 : The saddle according to  claim 3 , wherein the foamed particles have a diameter of from 0.5 mm to 5 cm. 
     
     
         5 : The saddle according to  claim 2 , wherein the foamed particles have a density of from 0.005 to 0.50 g/cm 3 . 
     
     
         6 : The saddle according to  claim 2 , wherein the thermoplastic polyurethane of the foamed particles is based on polytetrahydrofuran having a number average molecular weight of from 600 to 2500 g/mol. 
     
     
         7 : The saddle according to  claim 2 , wherein the thermoplastic polyurethane of the foamed particles is based on polyester alcohol having a number average molecular weight of from 500 to 2500 g/mol. 
     
     
         8 : The saddle according to  claim 2 , wherein the matrix of polyurethane is a foam, a compact elastomeric system or a gel. 
     
     
         9 : The saddle according to  claim 8 , wherein the matrix of polyurethane is a compact material and a weight ratio of the matrix to the foamed particles is from 1:1 to 1:20. 
     
     
         10 : The saddle according to  claim 2 , wherein the matrix of polyurethane is a foam having a density of from 0.03 to 0.8 g/cm 3 . 
     
     
         11 : The saddle according to  claim 2 , wherein a tear propagation resistance is greater than 2.5 N/mm at an average density of the hybrid material of from 0.4 to 0.5 g/cm 3 , greater than 2.2 N/mm at an average density of the hybrid material of from 0.3 to <0.4 g/cm 3 , greater than 2.0 N/mm at an average density of the hybrid material of from 0.2 to <0.3 g/cm 3  and greater than 1.0 N/mm at an average density of the hybrid material of from 0.1 to <0.2 g/cm 3 . 
     
     
         12 : A method of obtaining a saddle, the method comprising:
 forming a hybrid material into the saddle,   wherein the hybrid material comprises a matrix of polyurethane and foamed particles of thermoplastic polyurethane comprised therein, wherein the foamed particles have a closed surface skin.   
     
     
         13 : A process for producing a saddle with a hybrid material comprising a matrix of poly urethane and foamed particles of thermoplastic polyurethane comprised therein, the process comprising:
 mixing the following components, thereby obtaining a mixture:   a) a polyisocyanate,   b) a compound having a hydrogen atom which is reactive toward isocyanates,   c) expanded particles (c″) of thermoplastic polyurethane,   and, optionally,   d) a chain extender and/or a crosslinker,   e) a catalyst,   f) a blowing agent, and   g) a further additive;   reacting the mixture to form the hybrid material; and   preparing a saddle comprising the hybrid material.   
     
     
         14 : The process for producing a saddle according to  claim 13 , wherein the expanded particles (c″) have a diameter of from 0.1 mm to 10 cm, and are spherical or ellipsoidal. 
     
     
         15 : The process for producing a saddle according to  claim 13 , wherein the expanded particles (c″) have a density of from 0.005 to 0.50 g/cm 3  and have a compact outer skin. 
     
     
         16 : The process for producing a saddle according to  claim 13 , wherein no blowing agent is used. 
     
     
         17 : The process for producing a saddle according to  claim 16 , wherein an isocyanate prepolymer having an NCO content of from 1 to 20% by weight is first prepared from the polyisocyanate a) and the compound having a hydrogen atom which is reactive toward isocyanates b), and
 optionally, the chain extender and/or crosslinker d), the catalyst e), the further additive g) and the isocyanate prepolymer are subsequently mixed with the expanded particles (c″) of thermoplastic polyurethane, to form a composite, and   the composite is allowed to cure by action of water.   
     
     
         18 : The process for producing a saddle according to  claim 16 , wherein the weight ratio of the components a), b) and d)-g) to the component c) is from 1:1 to 1:20. 
     
     
         19 : A bicycle or a motorcycle, comprising the saddle according to  claim 2 .