Thermoplastic long fiber composites, methods of manufacture thereof and articles derived thererom

Abstract

An electrically conducting long fiber composite that offers improved surface resistivity and/or impact strength when used in a molded product. The composite includes a thermoplastic resin; carbon long fibers; and glass long fibers; wherein the carbon long fibers and the glass long fibers have a length of greater then or equal to about 2 millimeters and wherein the electrically conducting long fiber composite upon being molded into an article displays a surface resistivity of less than or equal to about 10 8 ohm per square centimeter and a notched Izod impact strength of greater than or equal to about 10 kilojoules per square meter.

1 . An electrically conducting long fiber composite comprising: 
 a thermoplastic resin;    carbon long fibers; and    glass long fibers; wherein the carbon long fibers and the glass long fibers have a length of greater then or equal to about 2 millimeters and wherein the electrically conducting long fiber composite upon being molded into an article displays a surface resistivity of less than or equal to about 10 8  ohm per square centimeter and a notched Izod impact strength of greater than or equal to about 10 kilojoules per square meter.    
     
     
         2 . The composite of  claim 1 , wherein the article has a surface resistivity of less than or equal to about 10 4  ohm per square centimeter and a notched Izod impact strength of greater than or equal to about 15 kilojoules per square meter.  
     
     
         3 . The composite of  claim 1 , wherein the article has a specific volume resistivity of less than or equal to about 10 4  ohm per square centimeter and a notched Izod impact strength of greater than or equal to about 20 kilojoules per square meter.  
     
     
         4 . The composite of  claim 1 , wherein the electrically conducting long fiber composite has a Class A surface finish.  
     
     
         5 . The composite of  claim 1 , wherein the carbon long fibers are produced by the pyrolysis of organic precursors in fibrous form.  
     
     
         6 . The composite of  claim 1 , wherein the carbon long fibers are derived from pitch, phenolics or polyacrylonitrile.  
     
     
         7 . The composite of  claim 1 , comprising carbon long fibers in an amount of up to about 50 weight percent, based on the weight of the electrically conducting long fiber composite.  
     
     
         8 . The composite of  claim 1 , wherein the glass long fibers are E-glass, A-glass, C-glass, D-glass, R-glass, S-glass or a combination comprising at least one of the foregoing glass fibers.  
     
     
         9 . The composite of  claim 1 , comprising glass long fibers in an amount of up to about 75 weight percent, based on the weight of the electrically conducting long fiber composite.  
     
     
         10 . The composite of  claim 1 , wherein the thermoplastic polymer is a polyarylene sulfide, a polyalkyd, a polystyrene, a polyester, a polyamide, a polyaramide, a polyamideimide, a polyarylate, a polyarylsulfone, a polyethersulfone, a polyimide, a polyetherimide, a polytetrafluoroethylene, a polyetherketone, a polyether etherketone, a polyether ketone ketone, a polybenzoxazole, a polyoxadiazole, a polybenzothiazinophenothiazine, a polybenzothiazole, a polypyrazinoquinoxaline, a polypyromellitimide, a polyquinoxaline, a polybenzimidazole, a polyoxindole, a polyoxoisoindoline, a polydioxoisoindoline, a polytriazine, a polypyridazine, a polypiperazine, a polypyridine, a polypiperidine, a polytriazole, a polypyrazole, a polycarborane, a polyoxabicyclononane, a polydibenzofuran, a polyphthalide, a polyacetal, a polyanhydride, a polyvinyl ether, a polyvinyl thioether, a polyvinyl alcohol, a polyvinyl ketone, a polyvinyl halide, a polyvinyl nitrile, a polyvinyl ester, a polysulfonate, a polysulfide, a polysulfonamide, a polyurea, a polyphosphazene, a polysilazane, a polysiloxane, a polyolefin, or a combination comprising at least one of the foregoing thermoplastic polymers.  
     
     
         11 . The composite of  claim 1 , further comprising at least one electrically conducting filler.  
     
     
         12 . The composite of  claim 1 , wherein the at least one electrically conducting filler is selected from short carbon fibers having a length of less than 2 millimeters, carbon black, carbon nanotubes, single wall carbon nanotubes, multiwall carbon nanotubes, vapor grown carbon fibers, metallic fillers, electrically conducting non-metallic fillers, or a combination comprising at least one of the foregoing electrically conductive fillers.  
     
     
         13 . An article derived from the composite of  claim 1 .  
     
     
         14 . The article of  claim 13 , wherein the article is used in an automobile.  
     
     
         15 . A method of manufacturing an electrically conducting long fiber composite comprising: 
 blending a carbon long fiber composite with a glass long fiber composite to produce an electrically conducting long fiber composite; wherein the carbon long fiber composite comprises carbon long fibers having a length of greater than or equal to about 2 millimeters disposed in a first thermoplastic resin; and wherein the glass long fiber composite comprises glass long fibers having a length of greater than or equal to about 2 millimeters disposed in a second thermoplastic resin.    
     
     
         16 . The method of  claim 15 , wherein the first thermoplastic resin is different from the second thermoplastic resin.  
     
     
         17 . The method of  claim 15 , wherein the first thermoplastic resin is the same as the second thermoplastic resin.  
     
     
         18 . The method of  claim 15 , wherein the electrically conducting long fiber composite has a surface resistivity of less than or equal to about 10 8  ohms per square centimeter and a notched Izod impact strength of greater than or equal to about 15 kilojoules per square meter.  
     
     
         19 . A method of manufacturing an electrically conducting long fiber comprising: 
 pultruding a first roving comprising carbon fibers through a first impregnation bath comprising a first molten thermoplastic polymer;    impregnating the carbon fibers with the first molten thermoplastic polymer to produce a carbon long fiber composite;    pultruding a second roving comprising glass fibers through a second impregnation bath comprising a second molten thermoplastic polymer;    impregnating the glass fibers with the second molten thermoplastic polymer to produce a glass long fiber composite; and    molding the carbon long fiber composite and the glass long fiber composite to form an electrically conducting long fiber composite.    
     
     
         20 . The method of  claim 19 , wherein the first roving is the same as the second roving and wherein the first impregnation bath is the same as the second impregnation bath, 
 and wherein the carbon long fiber composite and the glass long fiber composite are combined to form the electrically conducting long fiber composite in the impregnation bath.    
     
     
         21 . The method of  claim 19 , wherein the first roving is different from the second roving.  
     
     
         22 . The method of  claim 19 , wherein the first thermoplastic polymer is the same as the second thermoplastic polymer.  
     
     
         23 . The method of  claim 19 , wherein the first thermoplastic polymer is different from the second thermoplastic polymer.  
     
     
         24 . The method of  claim 19 , wherein the first impregnation bath is the same as the second impregnation bath.  
     
     
         25 . The method of  claim 19 , wherein the first impregnation bath is different from the second impregnation bath.  
     
     
         26 . The method of  claim 19 , further comprising pelletizing the carbon long fiber composite and the glass long fiber composite prior to molding.  
     
     
         27 . The method of  claim 19 , wherein the carbon long fiber composite and the glass long fiber composite have fiber lengths of greater than or equal to about 2 millimeter.  
     
     
         28 . The method of  claim 19 , wherein the electrically conducting long fiber composite has a surface resistivity of less than or equal to about 10 8  ohm per square centimeter and a notched Izod impact strength of greater than or equal to about 10 kilojoules per square meter.  
     
     
         29 . A method of manufacturing an electrically conducting composite comprising: 
 pultruding a roving comprising carbon fibers and glass fibers through an impregnation bath comprising a molten thermoplastic polymer;    impregnating the carbon fibers and the glass fibers with the molten thermoplastic polymer to produce an electrically conducting long fiber composite; and    molding the electrically conducting long fiber composite to form an article, wherein the article has a surface resistivity of less than or equal to about 10 8  ohm per square centimeter and a notched Izod impact strength of greater than or equal to about 15 kilojoules per square meter.    
     
     
         30 . The method of  claim 29 , further comprising pelletizing the electrically conducting long fiber composite.  
     
     
         31 . The method of  claim 29 , wherein the carbon fibers and the glass fibers in the electrically conducting long fiber composite have a length of greater than or equal to about 2 millimeter.  
     
     
         32 . The method of  claim 29 , wherein the article is used in an automobile.