Aqueous dispersion of polyamide rubber elastic body and method of producing the same

Abstract

An aqueous dispersion of polyamide rubber elastic body, which contains an aqueous medium and a polyamide rubber elastic body emulsified and dispersed in the aqueous medium in the presence of a surfactant. The surfactant is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the polyamide rubber elastic body, and is for example at least one member selected from the group consisting of a polyoxyalkylene alkyl ether sulfate, a dialkyl sulfosuccinate, a fatty acid salt and an ethylene oxide/propylene oxide copolymer. This aqueous dispersion can produce a molded article having the characteristics of the polyamide rubber elastic body, particularly a molded article which hardly suffers from bleeding of the surfactant and is excellent in transparency.

1 . An aqueous dispersion of polyamide rubber elastic body, comprising:
 an aqueous medium, and   a polyamide rubber elastic body emulsified and dispersed in the aqueous medium in the presence of a surfactant,   wherein the surfactant is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the polyamide rubber elastic body.   
   
   
       2 . The aqueous dispersion of polyamide rubber elastic body according to  claim 1 , wherein the polyamide rubber elastic body is one of copolymers among a polyether block amide copolymer and a polyether ester block amide copolymer. 
   
   
       3 . The aqueous dispersion of polyamide rubber elastic body according to  claim 1 , wherein the surfactant is at least one member selected from the group consisting of a polyoxyalkylene alkyl ether sulfate, a dialkyl sulfosuccinate, a fatty acid salt and an ethylene oxide/propylene oxide copolymer. 
   
   
       4 . The aqueous dispersion of polyamide rubber elastic body according to  claim 1 , further comprising a polymeric dispersion stabilizer. 
   
   
       5 . The aqueous dispersion of polyamide rubber elastic body according to  claim 1 , wherein the average particle diameter of particles of the emulsified and dispersed polyamide rubber elastic body is 0.1 to 5 μm. 
   
   
       6 . A molded article of polyamide rubber elastic body obtained from an aqueous dispersion of polyamide rubber elastic body comprising an aqueous medium and a polyamide rubber elastic body emulsified and dispersed in the aqueous medium in the presence of a surfactant, wherein the surfactant is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the polyamide rubber elastic body. 
   
   
       7 . A method of producing an aqueous dispersion of polyamide rubber elastic body, comprising the steps of:
 mixing an organic phase containing a polyamide rubber elastic body dissolved in an organic solvent, with an aqueous phase containing a surfactant dissolved in an aqueous medium, to prepare an emulsion, and   distilling the organic solvent off from the emulsion,   wherein the surfactant is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the polyamide rubber elastic body.   
   
   
       8 . The method of producing the aqueous dispersion of polyamide rubber elastic body according to  claim 7 , wherein the organic solvent is a mixture of an aromatic hydrocarbon solvent or an alicyclic hydrocarbon solvent and an alcohol solvent. 
   
   
       9 . The method of producing the aqueous dispersion of polyamide rubber elastic body according to  claim 7 , wherein the aqueous phase comprises a polymeric dispersion stabilizer. 
   
   
       10 . A method of producing an aqueous dispersion of polyamide rubber elastic body, comprising the steps of:
 preparing a mixture containing a polyamide rubber elastic body, a surfactant and an aqueous medium, and   emulsifying the mixture at a temperature not lower than the softening temperature of the polyamide rubber elastic body,   wherein the surfactant is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the polyamide rubber elastic body.