| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an analysis method whereby a content of a VA in an ethylene-vinylacetate copoylmer (EVA) or a content of an ethylacetate in an ethylene-ethylacerate copolymer (EEA) can be obtained by an infrared spectrophotometric analysis even for a mixture of the EVA and the EEA, and defects of the KBr tablet method can be solved. SOLUTION: The method includes steps (1) wherein a first calibration curve is obtained by plotting a ratio of a 1020 cm-1 peak height and a 1240 cm-1 peak height of an IR spectrum of the EVA with a known content of the VA with respect to the VA content, (2) wherein a second calibration curve is obtained by plotting a ratio of a 1160 cm-1 peak height and a 1465 cm-1 peak height of an IR spectrum of the EEA with a known content of the EA with respect to the EA content, (3) wherein a liquid film formed by dropping a solution of a sample of the EVA/EEA mixture to a KBr tablet surface is subjected to infrared spectrophotometric analysis to obtain an IR spectrum, and the VA content is obtained from the ratio of 1020 cm-1 and 1240 cm-1 peak heights based on the first calibration curve, (4) wherein the IR spectrum of the EVA having the VA content obtained in the step (3) is subtracted from the IR spectrum obtained in the step (3), thereby obtaining the IR spectrum corresponding to the EEA in the sample, and (5) wherein the EA content is obtained from the ratio of 1160 cm-1 and 1465 cm-1 peak heights in the IR spectrum obtained in the step (4) according to the second calibration curve.</p> |
