Water-based ink composition for writing instruments

Abstract

The present invention provides an aqueous ink composition for writing instruments in which the sedimentation of inorganic pigments with high specific gravity is suppressed. [Solution] The aqueous ink composition for writing instruments of the present invention, It contains at least resin particles containing inorganic pigments and hollow resin particles. The specific gravity of the inorganic pigment is 3.0 or higher.

Claims

1. It contains at least resin particles containing inorganic pigments and hollow resin particles. The specific gravity of the inorganic pigment is 3.0 or higher. Water-based ink composition for writing instruments.

2. The aqueous ink composition for writing instruments according to claim 1, further comprising a separate inorganic pigment.

3. The ratio of the average particle diameter of the resin particles to the average particle diameter of the separate inorganic pigment is 2.0 or more, and The aqueous ink composition for writing instruments according to claim 2, wherein the average particle size of the resin particles and the separate inorganic pigment is the volume-average particle size Mv obtained from the scattering intensity distribution measured by laser diffraction.

4. The aqueous ink composition for writing instruments according to claim 1 or 2, wherein the resin constituting the resin particles is at least one selected from the group consisting of urethane resin, urea resin, urea / urethane resin, melamine resin, acrylic resin, and olefin resin.

5. Temperature 25℃, shear rate 3.8s －１ The aqueous ink composition for writing instruments according to claim 1 or 2, wherein the viscosity measured under the specified conditions is 300 to 3000 mPa·s.

6. A writing instrument having the aqueous ink composition for writing instruments described in claim 1 or 2.

7. The writing instrument according to claim 6, which is a ballpoint pen.

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