| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of testing precisely and easily a degree of discoloration in a resin caused by nitrogen oxides, with a reduced measuring dispersion and error. SOLUTION: The progress degree of discoloration in a resin test piece is analyzed by a color difference meter, after the test piece is exposed to nitrogen oxides of a prescribed concentration at a prescribed temperature for a prescribed time. In a favorable embodiment in the present invention, (i) an urethane foam test piece is set in the inside of a sealed container, (ii) nitrogen oxides of the prescribed concentration are supplied from a standard container to the sealed container by a prescribed amount to prepare a prescribed concentration of atmosphere, (iii) the urethane foam test piece is exposed to nitrogen oxides at the prescribed temperature for the prescribed time under the atmosphere, (iv) the urethane foam test piece is taken out thereafter from the sealed container, and (v) a change degree in a yellow index YI of the urethane foam test piece is analyzed by the color difference meter. COPYRIGHT: (C)2005,JPO&NCIPI
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