Paramylon-based resin, molding material, molded body, and method for producing paramylon-based resin

Abstract

A paramylon-based resin having a weight-average molecular weight of paramylon in a range of 70000 to 140000, and formed by substituting hydrogen atoms of hydroxy groups of a paramylon with a long-chain component being a linear saturated aliphatic acyl group having 14 or more carbon atoms and a short-chain component being an acyl group (acetyl group or/and propionyl group) having 2 or 3 carbon atoms, wherein a degree of substitution with the long-chain component (DSLo) and a degree of substitution with the short-chain component (DSSh) satisfy the following conditional expressions (1) and (2), Izod impact strength is 5.0 kJ/m2 or more, and an MFR (melt flow rate at 210° C. and under a load of 5 kg) is 2 g/10 min or more. To provide a paramylon-based resin excellent in mechanical characteristics and thermoplasticity. 2.2≤DSLo+DSSh≤2.8 (1) 5≤DSSh/DSLo≤25 (2)

1 . A paramylon-based resin having a weight-average molecular weight of paramylon in a range of 70000 to 140000, and formed by substituting hydrogen atoms of hydroxy groups of a paramylon with a long-chain component being a linear saturated aliphatic acyl group having 14 or more carbon atoms and a short-chain component being an acyl group (acetyl group or/and propionyl group) having 2 or 3 carbon atoms,
 wherein a degree of substitution with the long-chain component (DS Lo ) and a degree of substitution with the short-chain component (DS Sh ) satisfy the following conditional expressions (1) and (2):
   2.2≤ DS   Lo   +DS   Sh ≤2.8  (1)
 
   5≤ DS   Sh   /DS   Lo ≤25  (2),
 
   Izod impact strength is 5.0 kJ/m 2  or more, and   an MFR (melt flow rate at 210° C. and under a load of 5 kg) is 2 g/10 min or more.   
     
     
         2 . The paramylon-based resin of  claim 1 , wherein DS Lo  is in a range of 0.1 to 0.5, and DS Sh  is in a range of 2.0 to 2.5 
     
     
         3 . The paramylon-based resin according to  claim 1 , wherein the long-chain component is an acyl group moiety of at least one fatty acid selected from myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid. 
     
     
         4 . A molding material comprising the paramylon-based resin according to  claim 1 . 
     
     
         5 . A molded body formed by using the molding material according to  claim 4 . 
     
     
         6 . A method for producing the paramylon-based resin according to  claim 1 , comprising:
 acylating hydroxy groups of a paramylon by reacting
 the paramylon having a weight average molecular weight of 70000 to 140000 and dispersed in a solvent with 
 acetyl chloride or/and propionyl chloride, and 
 a long-chain reactant being an acid chloride of a long-chain fatty acid and comprising the long-chain component, 
 in the presence of the acid trapping component and under warming; and 
   separating an acylated paramylon obtained in the acylating from the solvent.   
     
     
         7 . The method for producing the paramylon-based resin according to  claim 6 , wherein the solvent is at least one selected from the group consisting of water, acetic acid, dioxane, pyridine, N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide. 
     
     
         8 . The method for producing the paramylon-based resin according to  claim 6 , wherein the acid trapping component comprises triethylamine or pyridine. 
     
     
         9 . The method for producing the paramylon-based resin according to  claim 6 , wherein an amount of the solvent is 10 to 50 times as large as the dry mass of the paramylon.