Non-crosslinked copolymer foam composition with polyamide blocks and polyether blocks

Abstract

The present invention relates to a non-crosslinked block copolymer foam composition, characterised in that it is in the form of a polymer matrix comprising closed cells containing gas, said matrix comprising: from 90 to 99.9% by weight of said block copolymer; and from 0.01 to 10% by weight of metal carbonate, for the total weight of the foam composition. The present invention also relates to a foamable composition and a method for manufacturing said foam, as well as the use of the foam in sports shoe soles, balloons or balls, gloves, personal protection equipment, rail soles, automobile parts, construction parts, electrical and electronic equipment parts, audio equipment, sound- and/or heat-proofing, and parts used to damp vibrations.

1 - 11 . (canceled) 
     
     
         12 . A foamable copolymer composition with blocks comprising:
 (a) from 90 to 99.5% by weight of at least one block copolymer;   (b) from 0.5 to 10% by weight of a foaming agent comprising a metal hydrogen carbonate salt and at least one component chosen among:
 a polycarboxilic acid comprising 2 to 10 carbon atoms and at least two carboxyl groups; 
 a metal salt of said acid; 
 an ester of said polycarboxyilic acid wherein at least one of the carboxyl groups has been esterified with an alcohol comprising 1 to 6 carbon atoms; 
 and mixtures thereof, 
   
       wherein the weight percentages are in relation to the total weight of the foamable composition. 
     
     
         13 . The foamable copolymer composition according to  claim 12 , in which the foaming agent comprises an alkaline metal hydrogen carbonate and citric acid or a salt thereof. 
     
     
         14 . The foamable block copolymer composition according to  claim 12 , comprising from 0.5 to 20% by weight, for the total weight of the composition, of thermoplastic capsules containing a gas and which expand at a temperature comprised within the range of 90 to 250° C., said capsules having an average D50 size comprised within the range of 8 to 20 μm prior to expansion and an average D50 size comprised within the range of 30 to 130 μm after expanding in the foam. 
     
     
         15 . The foamable block copolymer composition according to  claim 12 , comprising from 0.1 to 10% by weight for the total weight of the composition, of at least one physical blowing agent. 
     
     
         16 . The foamable block copolymer composition according to  claim 12 , comprising from 10 to 50% by weight of a drying agent comprising zeolite and/or an alkaline earth metal oxide, for the total weight of the composition. 
     
     
         17 . A method for manufacturing a non-crosslinked hard-soft block copolymer foam composition, wherein the composition is in the form of a polymer matrix containing closed cells containing gas, said matrix comprising:
 from 90 to 99.9% by weight of at least one block copolymer; and   from 0.01 to 10% by weight of metal carbonate,   
       for the total weight of the foam composition, the method comprising the following steps:
 providing the foamable composition according to  claim 12 ; 
 heating said composition to a temperature such that the block copolymer melts and the foaming agent decomposes, which results in CO 2 , H 2 O and/or N 2 , in the form of gas dispersed within the melted block copolymer. 
 
     
     
         18 . The method according to  claim 17 , comprising the injection of said foamable composition into a mould, with the foaming of said composition performed when its heating has been achieved:
 when injecting it into the mould;   
       and/or
 by opening the mould. 
 
     
     
         19 . The method according to  claim 17 , comprising extruding the foamable composition and inducing foaming of the foamable composition by decomposition of the foaming agent directly at an extrusion outlet. 
     
     
         20 . The method according to  claim 17 , comprising heating the foamable composition in a reactor to create thermodynamic instability in a pressure and/or temperature swing, thereby causing the foamable composition to foam. 
     
     
         21 . The method according to  claim 17 , wherein the foamable composition comprises one or more additives. 
     
     
         22 . The method according to  claim 17 , wherein at least one physical blowing agent is also added to the foamable composition. 
     
     
         23 . The method according to  claim 17 , wherein the method does not use any gas injection device. 
     
     
         24 . The method according to  claim 17 , wherein the method comprises an injection method, without any gas injection step, resulting in a flexible foam with a density of less than 600 kg/m 3 . 
     
     
         25 . The foamable copolymer composition according to  claim 12 , wherein the at least one block copolymer comprises at least one block chosen among: the polyether blocks; the polyester blocks; the polyamide blocks; the polyurethane blocks; and combinations thereof. 
     
     
         26 . The foamable copolymer composition according to  claim 12 , wherein the at least one block copolymer is a hard-soft block copolymer, wherein:
 the hard blocks in the copolymer have a number-average molecular mass of 200 to 2000 g/mol;   the soft blocks in the copolymer have a number-average molecular mass of 800 to 2500 g/mol; and   the weight ratio of the hard blocks to the soft blocks in the copolymer is from 0.1 to 2.   
     
     
         27 . The foamable copolymer composition according to  claim 12 , wherein the at least one block copolymer comprises a copolymer with polyamide blocks and polyether blocks. 
     
     
         28 . The foamable copolymer composition according to  claim 27 , wherein the polyamide blocks in the copolymer are blocks comprising at least one of the following polyamide units: 11, 12, 6, 6.10, 6.12, 10.10, 10.12, and combinations thereof. 
     
     
         29 . The foamable copolymer composition according to  claim 27 , wherein the polyether blocks of the copolymer are blocks of polyethylene glycol or polytetramethylene glycol.