Iron soap, manufacturing method thereof, and thermoplastic resin composition containing iron soap

Abstract

An iron soap having a content A (%) of free fatty acid being 0.01≦A≦8.0, a content B (%) of water soluble salt being 0.01≦B≦0.5, and a granularity summary value C indicated in Formula (1) being 0.1≦C≦5.0, wherein the iron soap is a salt of a straight-chain saturated fatty acid having from 12 to 22 carbons and an iron. Granularity summary value C =( D 90− D 10)/ D 50(where 1.0≦ D 50≦40.0)  Formula (1) D10: 10% cumulative diameter (μm) of fatty acid metal salt particles on a volumetric basis D50: 50% cumulative diameter (μm) of fatty acid metal salt particles on a volumetric basis D90: 90% cumulative diameter (μm) of fatty acid metal salt particles on a volumetric basis

What is claimed is: 
     
         1 . An iron soap having a content A (%) of free fatty acid being 0.01≦A≦8.0, a content B (%) of water soluble salt being 0.01≦B≦0.5, and a granularity summary value C indicated in Formula (1) being 0.1≦C≦5.0, wherein the iron soap is a salt of a straight-chain saturated fatty acid having from 12 to 22 carbons and an iron,
   Granularity summary value  C =( D 90− D 10)/ D 50(where 1.0≦ D 50≦40.0)   Formula (1)
 
 D10: 10% cumulative diameter (μm) of fatty acid metal salt particles on a volumetric basis 
 D50: 50% cumulative diameter (μm) of fatty acid metal salt particles on a volumetric basis 
 D90: 90% cumulative diameter (μm) of fatty acid metal salt particles on a volumetric basis 
 
     
     
         2 . A method of manufacturing the iron soap according to  claim 1 , comprising the steps of:
 reacting, at a temperature equal to or lower than a crystal transition initiation temperature of the iron soap to be manufactured, between a straight-chain saturated fatty acid alkali metal salt aqueous solution having from 12 to 22 carbons and a trivalent iron salt aqueous solution with pH of 0.1 to 5.5 so as to prepare an iron soap slurry; and   adjusting pH of the prepared iron soap slurry to from 0.1 to 6.0.   
     
     
         3 . A thermoplastic resin composition comprising 0.01 to 10 parts by mass of the iron soap according to  claim 1  per 100 parts by mass of a thermoplastic resin. 
     
     
         4 . The thermoplastic resin composition according to  claim 3 , further comprising 0.1 to 100 parts by mass of fatty acid calcium soap per 100 parts by mass of the iron soap. 
     
     
         5 . The thermoplastic resin composition according to  claim 4 , wherein the fatty acid calcium soap has the granularity summary value C in Formula (1) being C≦2.0 and an aggregation degree E (%) indicated in Formula (2) being E≦20,
   Aggregation degree  E =[(mass of fatty acid metal salt particles remaining on a sieve with a mesh size of 350 μm)/2]×100×(1/1)+[(mass of fatty acid metal salt particles remaining on a sieve with a mesh size of 250 μm)/2]×100×(3/5)+[(mass of fatty acid metal salt particles remaining on a sieve with a mesh size of 150 μm)/2]×100×(1/5)]  Formula (2)