##STR00001##

The present application discloses films comprising regioselectively substituted cellulose esters and a component A wherein rings A, B, C, R.sup.1, R.sup.2, R.sup.5, R.sup.6, R.sup.8, m, n, and k are defined herein. The films are C+ films that exhibit improved wavelength dispersion. <

##STR00001##

The present application discloses films comprising regioselectively substituted cellulose esters and a component A wherein rings A, B, C, R.sup.1, R.sup.2, R.sup.5, R.sup.6, R.sup.8, m, n, and k are defined herein. The films are C+ films that exhibit improved wavelength dispersion. <

A process for producing an esterified cellulose ether can be efficiently be produced by reacting a moist cellulose ether having a water content of at least 10 percent, based on the weight of the moist cellulose ether, with an aliphatic monocarboxylic acid anhydride, a dicarboxylic acid anhydride or a combination thereof. Further improvements in efficiency and reduction in process steps are achieved in a process for producing an esterified cellulose ether which comprises the steps of a) reacting cellulose with an alkaline material to produce alkali cellulose, b) reacting the produced alkali cellulose with one or more etherifying agents and washing the produced cellulose ether to obtain a moist cellulose ether having a water content of at least 10 weight percent, and c) reacting the moist cellulose ether with an aliphatic monocarboxylic acid anhydride and/or a dicarboxylic acid anhydride and with a depolymerizing agent.

A process for producing an esterified cellulose ether comprises the step of reacting a cellulose ether with an aliphatic monocarboxylic acid anhydride and/or a dicarboxylic acid anhydride and with a depolymerizing agent, wherein the cellulose ether has an initial viscosity of at least 500 mPa.Math.s, measured as a 2 weight-% solution in water at 20° C., and the reaction of the cellulose ether with the aliphatic monocarboxylic acid anhydride and/or the dicarboxylic acid anhydride and with the depolymerizing agent is conducted simultaneously or in sequence in one reaction device.

A process for producing a cellulose ether acetate succinate comprises the step of reacting a cellulose ether with acetic anhydride, succinic anhydride and an depolymerizing agent, wherein the cellulose ether has an initial viscosity of at least 50 mPa-s, measured as a 2 weight-% solution in water at 20° C., and the reaction of the cellulose ether with acetic anhydride, succinic anhydride and the depolymerizing agent is conducted simultaneously or in sequence in one reaction device.

Provided are a composite for cellulose fiber dispersion that can inexpensively and sufficiently disperse cellulose fibers, particularly nanocellulose, in a hydrophobic resin and a cellulose fiber composition containing the composite. A composite for cellulose fiber dispersion according to the present invention has a structure in which a vinyl polymer is grafted to a cellulose derivative. A cellulose fiber composition according to the present invention contains the composite and cellulose fibers and more specifically also contains an organic solvent, a resin precursor, or a resin.

Provided are a composite for cellulose fiber dispersion that can inexpensively and sufficiently disperse cellulose fibers, particularly nanocellulose, in a hydrophobic resin and a cellulose fiber composition containing the composite. A composite for cellulose fiber dispersion according to the present invention has a structure in which a vinyl polymer is grafted to a cellulose derivative. A cellulose fiber composition according to the present invention contains the composite and cellulose fibers and more specifically also contains an organic solvent, a resin precursor, or a resin.

A process for recovering an esterified cellulose ether from a reaction product mixture obtained from a reaction of (a) a cellulose ether with (b) an aliphatic monocarboxylic acid anhydride or a di- or tricarboxylic acid anhydride or a combination of an aliphatic monocarboxylic acid anhydride and a di- or tricarboxylic acid anhydride, comprises the steps of (i) contacting the reaction product mixture with an aqueous liquid and precipitating the esterified cellulose ether from the reaction product mixture, and (ii) isolating the precipitated esterified cellulose ether from the mixture obtained in step (i), Tackiness of the esterified cellulose ether can be reduced when before or in step (i) a particulate silicon oxide or metal oxide is dispersed or suspended in the reaction product mixture, the aqueous liquid or a combination thereof.

Esterified cellulose ethers which have i) as ester groups aliphatic monovalent acyl groups or groups of the formula —C(O)—R—COOA or a combination of aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOA, wherein R is a divalent aliphatic or aromatic hydrocarbon group and A is hydrogen or a cation, and ii) a content of not more than 0.85 weight percent acetone-insoluble esterified cellulose ether particles, when the esterified cellulose ether is present in a mixture of 12.5 weight parts of esterified cellulose ether and 87.5 weight parts of acetone at 21° C., the weight percent acetone-insoluble esterified cellulose ether particles being based on the total weight of the esterified cellulose ether, wherein iii) not more than 14 percent of the acetone-insoluble esterified cellulose ether particles have a particle size of more than 90 micrometers.

An all-solid-state secondary battery includes a positive electrode active substance layer; a negative electrode active substance layer; and an inorganic solid electrolyte layer, in which at least one of the positive electrode active substance layer, the negative electrode active substance layer, or the inorganic solid electrolyte layer contains an inorganic solid electrolyte having conductivity of ions of metal belonging to Group 1 or 2 of the periodic table and a cellulose polymer.