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.

Provided are hypromellose acetate succinate (HPMCAS) which exhibits high solubility and can suppress generation of undissolved materials when dissolved in a solvent; an HPMCAS-containing composition; and a method for producing the HPMCAS. More specifically, provided are HPMCAS having a ratio of 2-position MS to 3-position MS of 1.2 or less, wherein the 2-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 2-position carbon of each glucose unit of the HPMCAS has been directly replaced, and the 3-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 3-position carbon of each glucose unit of the HPMCAS has been directly replaced; a composition comprising the HPMCAS and a solvent; and the method for producing the HPMCAS.

Provided are hypromellose acetate succinate (HPMCAS) which exhibits high solubility and can suppress generation of undissolved materials when dissolved in a solvent; an HPMCAS-containing composition; and a method for producing the HPMCAS. More specifically, provided are HPMCAS having a ratio of 2-position MS to 3-position MS of 1.2 or less, wherein the 2-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 2-position carbon of each glucose unit of the HPMCAS has been directly replaced, and the 3-position MS means a molar substitution of hydroxypropyl group by which a hydrogen atom of a hydroxyl group on 3-position carbon of each glucose unit of the HPMCAS has been directly replaced; a composition comprising the HPMCAS and a solvent; and the method for producing the HPMCAS.

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 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.

Provided herein are polysaccharide derivatives substituted (a) at a degree of substitution (DS1) of at least 0.05 by a fluorescent group (FG) having a mono or polycyclic ring system including at least one heteroatom selected from N, O and S and conjugated double bonds, and having an absorption band in the UV region of light and an emission band in the visible region of light, and bonded via a first linker to any one of the native functional groups of the polysaccharide repeating units; and (b) at a degree of substitution (DS2) of at least 0.05 by a charged group (CG) bonded via a second linker to any one of the native functional groups of the polysaccharide repeating units.

Disclosed is a method of preparing an acetylated cellulose ether. The disclosed method of preparing acetylated cellulose ether includes converting a cellulose ether to an acetylated cellulose ether in the presence of an acid catalyst.

Disclosed is a method of preparing an acetylated cellulose ether. The disclosed method of preparing acetylated cellulose ether includes converting a cellulose ether to an acetylated cellulose ether in the presence of an acid catalyst.

Esterified cellulose ethers which comprise (i) aliphatic monovalent acyl groups or (ii) groups of the formula C(O)RCOOA, wherein R is a divalent aliphatic or aromatic hydrocarbon group and A is hydrogen or a cation, or (iii) a combination of aliphatic monovalent acyl groups and groups of the formula C(O)RCOOA, which have a viscosity of up 19 mPa.Math.s, measured as a 10 wt % solution of the esterified cellulose ether in acetone at 20 C. and which have a weight average molecular weight M.sub.w of at least 90,000 Dalton, are useful for preparing solid dispersions comprising drugs.

Esterified cellulose ethers which comprise (i) aliphatic monovalent acyl groups or (ii) groups of the formula C(O)RCOOA, wherein R is a divalent aliphatic or aromatic hydrocarbon group and A is hydrogen or a cation, or (iii) a combination of aliphatic monovalent acyl groups and groups of the formula C(O)RCOOA, which have a viscosity of up 19 mPa.Math.s, measured as a 10 wt % solution of the esterified cellulose ether in acetone at 20 C. and which have a weight average molecular weight M.sub.w of at least 90,000 Dalton, are useful for preparing solid dispersions comprising drugs.