RETROREFLECTIVE WRITING MATERIAL HAVING HIGH BRIGHTNESS OF RETROREFLECTION AFTER WRITING

摘要

PURPOSE:To provide the titled writing material which can be smoothly written and has excellent adhesion to substrates, by using a specified spherical glass bead or a glass bead whose lower half has been aluminized under vacuum. CONSTITUTION:A spherical glass bead having a diameter for 20-100mu and a refractive index of 1.80-2.30 or a glass bead whose lower half has been aluminized under vacuum, is incorporated in a crayon-shaped or lipstick-shaped solid writing material.