Foam compositions and uses thereof

Abstract

A variety of foams and foam components are provided, including foam components for articles of footwear and athletic equipment. The articles include a composition having a foam structure, wherein the composition includes a thermoplastic copolyester elastomer comprising: (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. Methods of making the compositions and foams are provided, as well as methods of making an article of footwear including at least one of the foam components. In some aspects, the foams and foam components can be made by extrusion or injection molding to foam the polymeric composition, or extrusion or injection molding to foam the polymeric composition followed by compression molding of the foam.

What is claimed: 
     
         1 . A thermoplastic foam midsole component produced by the method comprising:
 forming a single phase solution (SPS) comprising a molten polymeric material and a supercritical fluid, wherein the molten polymeric material comprises a thermoplastic elastomer;   injecting the SPS into a mold cavity;   foaming the molten polymeric material of the SPS in the mold cavity by transitioning the supercritical fluid to a gas, thereby forming a foamed polymeric material;   solidifying the foamed polymeric material in the mold cavity, thereby forming a solidified midsole component including solidified thermoplastic foam having a multicellular foam structure, wherein the solidified thermoplastic foam has a specific gravity of from about 0.08 to about 0.31, and the solidified midsole component has a closed skin; and   removing the solidified midsole component from the mold cavity.   
     
     
         2 . The thermoplastic foam midsole component produced by the method of  claim 1 , wherein the thermoplastic elastomer is a thermoplastic copolyester elastomer, and the solidified thermoplastic foam is a solidified thermoplastic copolyester foam. 
     
     
         3 . The thermoplastic foam midsole component produced by the method of  claim 2 , wherein the solidified thermoplastic copolyester foam has an open-cell multicellular foam structure. 
     
     
         4 . The midsole component of  claim 2 , wherein the 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.   
     
     
         5 . The midsole component of  claim 2 , wherein the 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 dihydroxy-terminated polydiol of the first segment, wherein the dihydroxy-terminated polydiol 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 of the plurality 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, wherein the diol of the second segment 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. 
         
       
     
     
         6 . The midsole component of  claim 4 , wherein the thermoplastic copolyester elastomer consists essentially of about 40 weight percent to about 65 weight percent of the plurality of second copolyester units based on total weight of the thermoplastic copolyester elastomer. 
     
     
         7 . The midsole component of  claim 1 , wherein the supercritical fluid comprises nitrogen or carbon dioxide. 
     
     
         8 . The midsole component of  claim 1 , wherein the supercritical fluid is present in the SPS in an amount of from about 1 percent to about 5 percent by weight based upon a total weight of the SPS. 
     
     
         9 . The midsole component of  claim 1 , wherein the injecting the SPS into the mold cavity comprises injecting the SPS into a pressurized mold cavity, the pressurized mold cavity having a pressure greater than atmospheric pressure; and wherein the foaming the molten polymeric material comprises decreasing the first pressure to a second pressure initiating formation of gas bubbles by the supercritical fluid, thereby foaming the molten polymeric material. 
     
     
         10 . The midsole component of  claim 1 , wherein the injecting comprises monitoring an injection pressure of the mixture prior or during the injecting, and controlling the injecting based on the injection pressure of the mixture. 
     
     
         11 . The midsole component of  claim 1 , wherein the mixture has an expansion ratio of 1 as compared to a volume of the mold cavity. 
     
     
         12 . The midsole component of  claim 1 , wherein the foaming comprises applying a gas counter pressure to the mold cavity of from about 100 pounds per square inch to about 3,000 pounds per square inch, and wherein the gas counter pressure is applied to the mold cavity before the foaming. 
     
     
         13 . The midsole component of  claim 9 , wherein the second pressure is atmospheric pressure; and wherein decreasing the first pressure to the second pressure comprises venting the pressurized mold cavity to atmospheric pressure. 
     
     
         14 . The midsole component of  claim 9 , wherein the second pressure is atmospheric pressure; and wherein decreasing the first pressure to the second pressure comprises using a controlled rate of pressure decrease until the mold cavity has a pressure essentially equal to atmospheric pressure. 
     
     
         15 . The midsole component of  claim 14 , wherein the controlled rate of pressure decrease is from about 10 pounds per square inch per second to about 600 pounds per square inch per second. 
     
     
         16 . The midsole component of  claim 1 , wherein the solidifying comprises cooling the mold cavity; or wherein the solidifying comprises cooling the foamed molten polymeric material. 
     
     
         17 . The midsole component of  claim 1 , wherein the thermoplastic foam has an average cell size of from about 50 microns to about 5 millimeters. 
     
     
         18 . The midsole component of  claim 1 , wherein the thermoplastic foam has an energy efficiency when determined using a cyclic tensile test as described herein of greater than or equal to about 50%. 
     
     
         19 . The midsole component of  claim 1 , wherein the thermoplastic foam has a split tear value of about 1.0 kilogram per centimeter to 4.5 kilogram per centimeter. 
     
     
         20 . A method of manufacturing a consumer product, the method comprising affixing the midsole component of  claim 1  to a second component.