| 摘要 |
<p>A thermally foamable microsphere having a structure that a foaming agent is encapsulated in an outer shell formed from a polymer, wherein supposing an electric conductivity of a water extract obtained by Step 1 of dispersing 5 g of the thermally foamable microsphere in 20 g of ion-exchanged water having a pH of 7 and an electric conductivity of Ã1 at a temperature of 25°C to prepare a liquid dispersion; and Step 2 of shaking the liquid dispersion at the same temperature for 30 minutes to conduct a water extraction treatment, as measured at 25°C is Ã2, a difference Ã2 - Ã1 between Ã2 and Ã1 is at most 1 mS/cm, and a production process including measuring an electric conductivity of a filtrate in the washing step to obtain a thermally foamable microsphere exhibiting a desired electric conductivity on the basis of a previously prepared relational expression between the electric conductivity of the filtrate and the electric conductivity of a water extract of the thermally foamable microsphere.</p> |
