Polyphenylene sulfide fiber and process for producing the same

Abstract

A polyphenylene sulfide fiber has a large single-filament fineness, does not require special production equipment and serves as industrial material for uses where high rigidity is needed. A low-cost process produces the polyphenylene sulfide fiber with high spinnability. A polyphenylene sulfide fiber has a single-filament fineness of 10 to 50 dtex and a tenacity of 4.5 to 6 cN/dtex and the method attaches an aqueous lubricant to the surface up to 0.1 to 1 wt % and subsequently attaches a anhydrous lubricant to the surface so that the total weight of the surface-attached oil will accounts for 0.5 to 2 wt %.

1 . A polyphenylene sulfide fiber with a single-filament fineness of 10 to 1000 dtex and a tenacity of 4.5 to 6 cN/dtex. 
     
     
         2 . The polyphenylene sulfide fiber as claimed in  claim 1 , wherein a surface of the fiber carries at least a surface active agent and an antioxidant. 
     
     
         3 . The polyphenylene sulfide fiber as claimed in  claim 2 , wherein total weight of surface-attached oil accounts for 0.5 to 2 wt % of the fiber weight, with the surface active agent accounting for 0.01 to 1 wt % and the antioxidant accounting for 0.002 to 0.1 wt %. 
     
     
         4 . The polyphenylene sulfide fiber as claimed in  claim 1 , that is untwisted and has a total fineness of 100 to 1000 dtex and a filament count of 2 to 50. 
     
     
         5 . The polyphenylene sulfide fiber as claimed in  claim 1 , having elongation of 15 to 25%, and dry-heat shrinkage at 150° C. of 2 to 10%. 
     
     
         6 . The polyphenylene sulfide fiber as claimed in  claim 1 , having fineness unevenness of 0.5 to 1%. 
     
     
         7 . A method of producing polyphenylene sulfide fibers with a single-filament fineness of 10 to 100 dtex comprising:
 melt-spinning polyphenylene sulfide resin;   processing resulting fibers with an aqueous emulsion lubricant while being pulled to cause surface-attached oil to account for 0.1 to 1 wt %, and, without being wound up, stretching the fibers at an overall draw ratio of 3.8 to 4.5.   
     
     
         8 . The method as claimed in  claim 7 , further comprising applying an anhydrous lubricant to a total percentage of surface-attached oil of 0.5 to 2 wt %. 
     
     
         9 . The method as claimed in  claim 7 , wherein the aqueous emulsion lubricant has an oil concentration of 15 to 40 wt %. 
     
     
         10 . The polyphenylene sulfide fiber as claimed in  claim 2 , that is untwisted and has a total fineness of 100 to 1000 dtex and a filament count of 2 to 50. 
     
     
         11 . The polyphenylene sulfide fiber as claimed in  claim 3 , that is untwisted and has a total fineness of 100 to 1000 dtex and a filament count of 2 to 50. 
     
     
         12 . The polyphenylene sulfide fiber as claimed in  claim 2 , having elongation of 15 to 25%, and dry-heat shrinkage at 150° C. of 2 to 10%. 
     
     
         13 . The polyphenylene sulfide fiber as claimed in  claim 3 , having elongation of 15 to 25%, and dry-heat shrinkage at 150° C. of 2 to 10%. 
     
     
         14 . The polyphenylene sulfide fiber as claimed in  claim 4 , having elongation of 15 to 25%, and dry-heat shrinkage at 150° C. of 2 to 10%. 
     
     
         15 . The method as claimed in  claim 8 , wherein the aqueous emulsion lubricant has an oil concentration of 15 to 40 wt %.