EVALUATION METHOD OF MIXTURE LIQUID OF DISPERSION LIQUID INCLUDING RUBBER CONSTITUENT AND CELLULOSE NANOFIBER DISPERSION LIQUID

摘要

To provide an evaluation method capable of easily determining presence or absence of an aggregated cellulose nanofibers, which cannot be visually determined, in a mixture liquid comprising dispersion liquid of a rubber constituent and a cellulose nanofiber dispersion liquid.SOLUTION: Provided is an evaluation method, including steps (1) to (4), of a mixture liquid of a dispersion liquid including a rubber constituent and a cellulose nanofiber dispersion liquid. A step (1) prepares the mixture liquid of the dispersion liquid including the rubber constituent and the cellulose nanofiber dispersion liquid. A step (2) adds a colored pigment into the mixture liquid. A step (3) observes the mixture liquid, described in the step (1), added with the colored pigment using an optical microscope. A step (4) calculates area ratio of a cellulose nanofiber aggregate in the mixture liquid added with the colored pigment, described in the step (3), of the dispersion liquid including the rubber constituent and the cellulose nanofiber dispersion liquid.SELECTED DRAWING: Figure 2