METHOD FOR MEASURING SILICA ADHESION AMOUNT OF SYNTHETIC FIBER

To obtain a method for measuring silica adhesion amount of synthetic fibers to which oil agent containing colloidal silica is adhered, which can be used for production step control.SOLUTION: The method for measuring silica adhesion amount includes: a step of preparing a standard sample containing oil agent and silica standard solution; a step of preparing a test sample by processing the synthetic fiber; a step of coloring the standard sample and the test sample yellow by mixing ammonium molybdate under acidic conditions, and then measuring the absorbance at least two wavelengths including wavelength 1 in the range of 385-440 nm and wavelength 2 in the range of 500-700 nm; a step of creating a calibration curve from the absorbance measured for the standard sample at two wavelengths; and a step of calculating the silica adhesion amount from the absorbance measured for the test sample at two wavelengths and the calibration curve. The step of preparing the standard sample and the test sample comprises a process of mixing a synthetic fiber with oil agent or oil agent containing colloidal silica adhered thereto, water and sodium hydrogen carbonate, and boiling the mixture.SELECTED DRAWING: Figure 1 【課題】生産工程の工程管理に用いることができる、コロイド状シリカを含む油剤が付着した合成繊維のシリカ付着量の測定方法を得る。【解決手段】油剤とシリカ標準液を含む標準試料を作製する工程と、合成繊維を処理して検査試料を作製する工程と、標準試料及び検査試料について、酸性条件下でモリブデン酸アンモニウムを混合して黄色に呈色した後、３８５〜４４０ｎｍの範囲の波長１と、５００〜７００ｎｍの範囲の波長２の少なくとも、２波長の吸光度を測定する工程と、測定した２波長の標準試料の吸光度から検量線を作成する工程と、測定した２波長の検査試料の吸光度と検量線とからシリカ付着量を算出する工程とを含み、標準試料及び検査試料を作製する工程は、油剤またはコロイド状シリカを含む油剤を付着した合成繊維、水及び炭酸水素ナトリウムを混合し、煮沸する処理を含む、シリカ付着量の測定方法。【選択図】図１