Patent ID: 7910672

Claim:
A powder of polyvinylpyrrolidone having a K value of smaller than 50 as determined by a Fikentscher's method, comprising a content of vinylpyrrolidone polymer particles having a particle diameter of 106 μm or smaller of 10% by mass or lower and a content of vinylpyrrolidone polymer particles having a particle diameter of greater than 1,000 μm of 5% by mass or lower, wherein a dissolution time when 1 g of the powder of polyvinylpyrrolidone is dissolved in 100 g of water under stirring at 500 rpm is 250 seconds or less, and wherein the powder of polyvinylpyrrolidone is produced by: forming a polyvinylpyrrolidone solution having a K value of smaller than 50 as determined by a Fikentscher's method and a concentration from 30% to 70% by mass, drying the solution by using a hot surface adhesion-type dryer, and pulverizing the dried solution so that a content of vinylpyrrolidone polymer particles having a particle diameter of 106 μm or smaller is 10% by mass or lower and a content of vinylpyrrolidone polymer particles having a particle diameter of greater than 1,000 μm is 5% by mass or lower.