Foam compositions and uses thereof

Abstract

Components for articles of footwear and athletic equipment including a foam are provided. The foam portion of the components and articles include a composition which includes a thermoplastic copolyester, the composition having a foam structure. A polymer layer is provided on at least on surface of the foam portion. The polymer layer can control or reduce the water uptake of the foam portion. Methods of making the compositions, foams, and components are provided, as well as methods of making an article of footwear including one of the foam components. In some aspects, the foams and foam components can be made by injection molding, or injection molding followed by compression molding.

What is claimed: 
     
         1 . A cushioning element for an article of footwear, the cushioning element comprising:
 a first foam component having an exterior surface, the foam component comprising a foamed first thermoplastic composition comprising a first thermoplastic copolyester elastomer having a multicellular foam structure; and   a polymeric layer comprising a second thermoplastic composition comprising a second thermoplastic elastomer, and the polymeric layer is disposed on at least a portion of the exterior surface of the first foam component;   wherein the first thermoplastic composition is structurally different than the second thermoplastic composition.   
     
     
         2 . The cushioning element of  claim 1 , wherein the second thermoplastic elastomer comprises a thermoplastic polyurethane elastomer, a thermoplastic polyurea elastomer, a thermoplastic polyether elastomer, a thermoplastic polyester elastomer, a thermoplastic polyamide elastomer, a thermoplastic polystyrene elastomer, a thermoplastic polyolefin elastomer, a thermoplastic polyimide elastomer, any copolymer thereof, or any blend thereof. 
     
     
         3 . The cushioning element of  claim 1 , wherein the second thermoplastic composition comprises one or more thermoplastic polyurethanes (TPUs). 
     
     
         4 . The cushioning element of  claim 1 , wherein the second thermoplastic composition comprises (i) a thermoplastic polyurethane elastomer and (ii) ethylene-vinyl acetate (EVA) copolymer, a styrene-butadiene copolymer, an ethylene-vinyl alcohol copolymer, or any combination thereof. 
     
     
         5 . The cushioning element of  claim 1 , wherein the second thermoplastic composition comprises a second thermoplastic copolyester elastomer. 
     
     
         6 . The cushioning element of  claim 5 , wherein the first thermoplastic copolyester elastomer comprises
 (a) a plurality of first segments, each first segment derived from a dihydroxy-terminated polydiol;   (b) a plurality of second segments, each second segment derived from a diol; and   (c) a plurality of third segments, each third segment derived from an aromatic dicarboxylic acid.   
     
     
         7 . The cushioning element of  claim 1 , wherein the first thermoplastic copolyester elastomer comprises,
 (a) a plurality of first copolyester units, each first copolyester unit of the plurality comprising the first segment derived from a dihydroxy-terminated polydiol and the third segment derived from an aromatic dicarboxylic acid, wherein the first copolyester unit has a structure represented by a formula 1:   
       
         
           
           
               
               
           
         
         
           wherein R 1  is a group remaining after removal of terminal hydroxyl groups from the poly(alkylene oxide) diol of the first segment, wherein the poly(alkylene oxide) diol of the first segment is a poly(alkylene oxide) diol having a number-average molecular weight of about 400 to about 6000; and wherein R 2  is a group remaining after removal of carboxyl groups from the aromatic dicarboxylic acid of the third segment; and 
         
         (b) a plurality of second copolyester units, each second copolyester unit of the plurality comprising the second segment derived from a diol and the third segment derived from an aromatic dicarboxylic acid, wherein the second copolyester unit has a structure represented by a formula 2: 
       
       
         
           
           
               
               
           
         
       
       wherein R 3  is a group remaining after removal of hydroxyl groups from the diol of the second segment derived from a diol, wherein the diol is a diol having a molecular weight of less than about 250; and wherein R 2  is the group remaining after removal of carboxyl groups from the aromatic dicarboxylic acid of the third segment. 
     
     
         8 . The cushioning element of  claim 1 , wherein the first foam comprises a thermoplastic multicellular foam having an open cell foam microstructure, an average cell size of from about 100 microns to about 1 millimeter, and a specific gravity of about 0.05 to about 0.25;
 wherein the first thermoplastic composition of the first foam is free or essentially free of nucleating agents, or is free or essentially free of fillers, or is free or essentially free of both nucleating agents and fillers.   
     
     
         9 . The cushioning element of  claim 1 , wherein the polymeric layer has an average thickness of from about 0.01 millimeter to about 3 millimeter. 
     
     
         10 . The cushioning element of  claim 1 , wherein the cushioning element has a water uptake capacity at 5 minutes that is at least 2 percentage points less than a water uptake capacity at 5 minutes for an equivalent cushioning element that lacks the polymeric layer as determined using the Water Uptake Capacity Test method. 
     
     
         11 . The cushioning element of  claim 1 , wherein the cushioning element has a ply adhesion strength between the polymeric layer and the foam component that is greater than 2.5 kg force/centimeter when determined using the Ply Adhesion Test method described herein. 
     
     
         12 . The cushioning element of  claim 1 , wherein the cushioning element has an average hand pull test result between the polymeric layer and the foam component that is greater than or equal to 2.0, when determined according to the Hand Pull Test method described herein. 
     
     
         13 . The cushioning element of  claim 1 , wherein the cushioning element is a midsole or a heel cushion. 
     
     
         14 . An article of footwear comprising the cushioning element of  claim 1 . 
     
     
         15 . A method of making a cushioning element for an article of footwear, the method comprising:
 forming a first foam component having an exterior surface, the foam component comprising a foamed first thermoplastic composition comprising a first thermoplastic copolyester elastomer having a multicellular foam structure; and   disposing a polymeric layer on at least a portion of the exterior surface of the first foam component, wherein the polymeric layer comprises a second thermoplastic composition comprising a second thermoplastic elastomer;   wherein the first thermoplastic composition is structurally different than the second thermoplastic composition.   
     
     
         16 . The method of  claim 15 , wherein the forming comprises injection molding and foaming the first foam component by injection molding the first thermoplastic composition in an injection mold, solidifying the first thermoplastic composition to retain the multicellular foam structure, and removing the solidified first foam component from the injection mold; and wherein the disposing comprises, after the solidifying, applying heat or vacuum or both heat and vacuum to a thermoplastic film comprising the second thermoplastic composition, thereby disposing and bonding the polymeric film to the exterior surface of the first foam component, forming the polymeric layer on the exterior surface of the first foam component, and forming the cushioning element. 
     
     
         17 . The method of  claim 15 , wherein the forming comprises injection molding and foaming the first foam component by injection molding the first thermoplastic composition in an injection mold, solidifying the first thermoplastic composition to retain the multicellular foam structure, and removing the solidified first foam component from the injection mold; and wherein the disposing comprises, after the solidifying, applying the second thermoplastic composition in liquid form to the exterior surface of the first foam component, and allowing the second thermoplastic composition to solidify, thereby forming, disposing and bonding the polymeric layer to the exterior surface of the first foam component and forming the cushioning element. 
     
     
         18 . The method of  claim 17 , wherein the applying the second thermoplastic composition in liquid form comprises spraying, printing, or painting the second thermoplastic composition onto the exterior surface, and the allowing the second thermoplastic composition to solidify comprises evaporating a solvent from the second thermoplastic composition. 
     
     
         19 . The method of  claim 15 , wherein the forming and disposing comprise placing a polymeric film comprising the second thermoplastic composition in a mold; melting the first polymeric composition; foaming the molten first polymeric composition; extruding the foamed first polymeric composition into the mold and onto an exposed surface of the polymeric film in the mold; solidifying the foamed first thermoplastic material, thereby bonding the exposed surface of the polymeric film to the solidified foamed first thermoplastic material and forming the polymeric layer on the first foam component, and thereby forming the cushioning element; and removing the cushioning element from the mold. 
     
     
         20 . The method of  claim 15 , wherein the forming and disposing comprise placing a polymeric film comprising the second thermoplastic composition in an injection mold; melting the first polymeric composition; injecting the molten first polymeric composition into the mold and onto an exposed surface of the polymeric film in the mold; foaming the molten first polymeric composition in the mold; solidifying the foamed first thermoplastic material, thereby bonding the exposed surface of the polymeric film to the solidified foamed first thermoplastic material and forming the polymeric layer on the first foam component, and thereby forming the cushioning element; and removing the cushioning element from the injection mold.