Direct method for preparing doped polyaniline, product prepared thereby and resinous articles containing said product

Abstract

Doped polyanilines are prepared by contacting aniline with an oxidizing agent such as ammonium peroxydisulfate in aqueous solution at a temperature of at most about 10° C. in the presence of at least one organic sulfonic acid, preferably an alkylbenzenesulfonic acid such as dodecylbenzenesulfonic acid. The products may be blended with thermoplastic resins such as polystyrene to produce blends having excellent static discharge properties

What is claimed is:  
     
         1 . A method for preparing an electrically conductive polyaniline which comprises contacting aniline with an oxidizing agent in aqueous solution at a temperature of at most about 10° C. in the presence of at least one organic sulfonic acid.  
     
     
         2 . A method according to    claim 1    wherein the oxidizing agent is ammonium peroxydisulfate.  
     
     
         3 . A method according to    claim 2    wherein the sulfonic acid is an alkylbenzenesulfonic acid.  
     
     
         4 . A method according to    claim 3    wherein the alkylbenzenesulfonic acid is dodecylbenzenesulfonic acid.  
     
     
         5 . A method for preparing an electrically conductive polyaniline which comprises contacting aniline with ammonium peroxydisulfate in aqueous solution at a temperature in the range of about 0-10° C. in the presence of at least one alkylbenzenesulfonic acid, the molar ratio of said ammonium peroxydisulfate to said aniline being in the range of about 1.0-1.2:1 and the sulfonic acid being present in the amount of about 5-10 ml per gram of aniline.  
     
     
         6 . A method according to    claim 5    wherein the alkylbenzenesulfonic acid is dodecylbenzenesulfonic acid.  
     
     
         7 . A sulfonic acid-doped polyaniline prepared by the method of    claim 1   .  
     
     
         8 . A sulfonic acid-doped polyaniline prepared by the method of    claim 3   .  
     
     
         9 . A sulfonic acid-doped polyaniline prepared by the method of    claim 4   .  
     
     
         10 . A sulfonic acid-doped polyaniline prepared by the method of    claim 5   .  
     
     
         11 . A sulfonic acid-doped polyaniline prepared by the method of    claim 6   .  
     
     
         12 . A method of isolating polyaniline doped with at least one organic sulfonic acid which comprises precipitating said doped polyaniline from aqueous solution by combination with a mixture of water and a C 1-4  water-miscible alkanol and separating the precipitated polyaniline from said solution.  
     
     
         13 . A method according to    claim 12    wherein the alkanol-water mixture contains an amount up to about 95% by weight water with the balance being alkanol.  
     
     
         14 . A method according to    claim 12    wherein the sulfonic acid is an alkylbenzenesulfonic acid.  
     
     
         15 . A method according to    claim 14    wherein the alkylbenzenesulfonic acid is dodecylbenzenesulfonic acid.  
     
     
         16 . A method according to    claim 12    wherein the alkanol is 2-propanol.  
     
     
         17 . A conductive resinous composition comprising at least one thermoplastic resin and a sulfonic acid-doped polyaniline according to    claim 7   .  
     
     
         18 . A composition according to    claim 17    wherein the thermoplastic resin is selected from the group consisting of olefin polymers, diene polymers, alkenylaromatic polymers other than diene polymers, vinyl halide polymers, vinyl ester and alcohol polymers, acrylic polymers, polycarbonates, polyesters, polyphenylene ethers, polyarylene sulfides, polyetherimides and polyethersulfones.  
     
     
         19 . A composition according to    claim 18    wherein the thermoplastic resin is polystyrene.  
     
     
         20 . A composition according to    claim 18    comprising about 60-99% by weight of said thermoplastic resin and correspondingly about 1-40% of said doped polyaniline.  
     
     
         21 . A conductive resinous composition comprising about 60-99% by weight of polystyrene and correspondingly about 1-40% of a dodecylbenzenesulfonic acid-doped polyaniline according to    claim 11   .