Cellulose acetate

It is an object of the present invention to provide a cellulose acetate capable of reducing yarn breakage in a spinning process while having excellent moist heat stability. Cellulose acetate that satisfies the relationship represented by the following formula (1) by the chemical equivalent ratio [Ca/HSO] of the calcium content to the residual sulfuric acid content and the chemical equivalent ratio [Mg/HSO] of the magnesium content to the residual sulfuric acid content. [Mg/HSO] 0， [Ca/HSO] 0， also (2.70-[Mg/HSO])/1.62 [Ca/HSO] (37.7-[Mg/HSO])/10.3 (1) The purpose of the present invention is to provide a cellulose acetate which has excellent hygrothermal stability and which can have reduced yarn breakage in a spinning step. The cellulose acetate satisfies a relationship represented by formula (1) between the chemical equivalent ratio [Ca/H 2SO4] of the calcium content to the amount of remaining sulfuric acid， and the chemical equivalent ratio [Mg/H2SO4] of the magnesium content to the amount of remaining sulfuric acid. [Mg/H2SO4] > 0， [Ca/H2SO4] > 0， and (2.70 - [Mg/H2SO4])/1.62 ≤ [Ca/H2SO4] ≤ (37.7 - [Mg/H2SO4])/10.3 (1) The purpose of the present invention is to provide a cellulose acetate which has excellent hygrothermal stability and which can have reduced yarn breakage in a spinning step. The cellulose acetate satisfies a relationship represented by formula (1) between the chemical equivalent ratio [Ca/H2SO4] of the calcium content to the amount of remaining sulfuric acid， and the chemical equivalent ratio [Mg/H2SO4] of the magnesium content to the amount of remaining sulfuric acid. [Mg/H2SO4] > 0， [Ca/H2SO4] > 0， and (2.70 - [Mg/H2SO4])/1.62 ≤ [Ca/H2SO4] ≤ (37.7 - [Mg/H2SO4])/10.3 (1)