The purpose of the present invention is to provide a
powder detergent composition that contains a biodegradable additive and exhibits excellent cleaning performance when used as a
powder detergent, and therefore has low environmental
impact. The present invention relates to a
powder detergent composition containing a
vinyl alcohol polymer and a surfactant. The
vinyl alcohol polymer has a
structural unit (a) represented by formula (1) and may also have a
structural unit (b) represented by formula (2) and an other
structural unit (c) other than structural unit (a) and structural unit (b). The content ratio of each structural unit in relation to the total amount of 100 mol% of all of the structural units is structural unit (a) / structural unit (b) / other structural unit (c) = 50-100 / 0-50 / 0-20 mol%. The average
degree of polymerization is 50-800. The content ratio of the surfactant in relation to 100
mass% of the powder detergent composition is 10-80
mass%. The content ratio of powder
soap in relation to the total amount of 100
mass% of the surfactant is 1-100 mass%. The content ratio of a carboxyl group-containing
polymer in relation to 100 mass% of the powder detergent composition is 0-1 mass%, and the content ratio of a
phosphorus compound in relation to 100 mass% of the powder detergent composition is 0-1 mass%.