| 摘要 |
<p>This invention provides a material for pressure measurement which develops a color by taking advantage of a color development reaction between an electron donating colorless dye precursor and an electron receiving compound and causes a difference in color density between before the application of a pressure of 0.05 MPa and after the application of a pressure of 0.05 MPa, i.e., ?D, of not less than 0.02. Preferably, the electron donating colorless dye precursor is included in a microcapsule, and, when the median diameter of the microcapsule on a volume basis is A µm, 5000 to 30000 microcapsules having a diameter of not less than (A + 5) µm are present per 2 cm x 2 cm.</p> |
