Method for recycling of phenolic antioxidant agent, process for production of olefin polymer, polyolefin powder, and fibers

Abstract

Provided are a recycling method for industrially, simply and effectively recycling a phenolic body from a phenolic antioxidant which is masked by an organoaluminum compound and contained in an olefin polymer obtained by supplying the masked phenolic antioxidant upon polymerization; and an olefin polymer obtained by this method. In a method for recycling a phenolic antioxidant wherein a phenolic antioxidant which is masked by an organoaluminum compound and contained in an olefin polymer obtained by supplying the masked phenolic antioxidant upon polymerization is recycled to a phenolic body, a nitrogen gas comprising water and/or a proton donor at a volume ratio of 1.0×10 −6 to 2.5×10 −2 with respect to 1 volume of nitrogen is brought into contact with the olefin polymer.

1 . A method for producing a stabilized olefin polymer, wherein an additive(s) and a promoter component(s) are supplied to olefin monomers upon polymerization of said olefin monomers, wherein
 said method comprises a step wherein a slurry additive(s) is/are pumped while being mixed with a promoter component(s) in a pipe(s), followed by transferring the resulting mixture to a polymerization tank for olefin monomers.   
     
     
         2 . The method for producing a stabilized olefin polymer according to  claim 1 , wherein said promoter component(s) is/are an organoaluminum compound(s). 
     
     
         3 . The method for producing a stabilized olefin polymer according to  claim 1 , wherein said promoter component(s) is/are a trialkyl aluminum(s). 
     
     
         4 . The method for producing a stabilized olefin polymer according to  claim 1 , wherein said additive(s) comprise(s) a phenolic antioxidant represented by the General Formula (1) below: 
       
         
           
           
               
               
           
         
         (wherein R represents C 12 -C 24  alkyl which is optionally branched, C 3 -C 12  cycloalkyl which is optionally substituted, or C 6 -C 18  aryl which optionally has a substituent(s)) and is/are prepared by dissolving a liquid phenolic antioxidant(s) and/or a powdered phenolic antioxidant(s) in a solvent or by mixing a powdered phenolic additive(s) in an inert solvent. 
       
     
     
         5 . The method for producing a stabilized olefin polymer according to  claim 1 , wherein said additive(s) preliminarily dissolved in a solvent is/are supplied to said pipe(s) for transferring said promoter component(s) to said polymerization tank for olefin monomers, to mix said promoter component(s) with said additive(s) in said pipe(s). 
     
     
         6 . The method for producing a stabilized olefin polymer according to  claim 1 , wherein said solvent is selected from aliphatic hydrocarbons and alicyclic hydrocarbons. 
     
     
         7 . The method for producing a stabilized olefin polymer according to  claim 1 , wherein said pipe(s) is/are a pipe(s) having a line mixer. 
     
     
         8 . The method for producing a stabilized olefin polymer according to  claim 1 , wherein the concentration of said additive component(s) is within the range of 1 to 80% by mass in said slurry additive(s).