Cellulose resin, molding material, molded body, and method for producing cellulose resin
A cellulose resin in which hydrogen atoms of hydroxy groups of cellulose are substituted with a long-chain component which is a linear aliphatic acyl group having 14 or more carbon atoms and a short-chain component which is at least one of an acyl group having 2 carbon atoms and an acyl group having 3 carbon atoms, wherein a nitrogen content in the cellulose resin is 300 ppm or more and 2000 ppm or less. To provide a cellulose resin excellent in mechanical properties and heat decomposition resistance.
1. A method for producing a cellulose resin in which hydrogen atoms of hydroxy groups of cellulose are substituted with a long-chain component which is a linear aliphatic acyl group having 14 to 48 carbon atoms and a short-chain component which is at least one of an acyl group having 2 carbon atoms and an acyl group having 3 carbon atoms,
wherein a nitrogen content in the cellulose resin is 300 ppm or more and 2000 ppm or less, and wherein, in a GPC chromatogram (elution curve) of the cellulose resin, measured by gel permeation chromatography (GPC), the GPC chromatogram has a sub-peak or a reading in a region having a molecular weight of 9 million or more, and a content ratio (area ratio) of a high molecular weight component corresponding to the region is in a range of 2 to 10%,
the method comprising:
reacting a pulp dispersed in an organic solvent with a short chain acylating agent for introducing an acyl group having 2 to 3 carbon atoms and a long-chain acylating agent for introducing an acyl group having 14 to 48 carbon atoms, in the presence of a basic nitrogen-containing organic compound under heating at 100° C. or below, to acylate hydroxy groups of a cellulose constituting the pulp; and
separating an acylated cellulose obtained by the acylation from the organic solvent,
wherein a mixing ratio (mass ratio R/S) of the basic nitrogen-containing organic compound (R) and the organic solvent (S) is in a range of 5/95 to 30/70,
the basic nitrogen-containing organic compound is pyridine,
the organic solvent is N-methylpyrrolidone,
the short chain reagent is at least one selected from acetyl chloride, acetic anhydride, propionic anhydride and propionyl chloride,
the long-chain reactive agent is an acid chloride of a linear fatty acid having 14 or more carbon atoms, and
a reaction temperature of the acylation is in a range of 70 to 100° C.
2. The method for producing a cellulose resin according to claim 1 , wherein a total amount of the organic solvent and the basic nitrogen-containing organic compound is 10 to 50 times the dry mass of the pulp.
3. The method for producing a cellulose resin according to claim 1 , wherein a degree of substitution DS Lo with the long-chain component is in a range of 0.2 to 0.6, and a degree of substitution DS Sh with the short-chain component is in a range of 1.7 to 2.8.
4. The method for producing a cellulose resin according to claim 1 , wherein the cellulose resin has a pyridine ring coordinated to the cellulose.
5. The method for producing a cellulose resin according to claim 1 , wherein the nitrogen content is a content of nitrogen derived from a pyridine ring coordinated to the cellulose.
6. The method for producing a cellulose resin according to claim 1 , a nitrogen content in the cellulose resin is 300 ppm or more and 1000 ppm or less.