Aqueous ink composition for writing instruments
AssigneeMitsubishi Pencil Company, Limited
InventorKosuke Ogura
Life of this patent
Estimating the term…
Abstract
An aqueous ink composition for writing instruments may contain colored resin particles encapsulating a pigment, wherein the ink is not repelled when the aqueous ink composition for writing instruments is used to write on a paper face attached with hand fingers or the like, and achieves a uniform density in a drawn line and excellent writing capability. An embodiment of the aqueous ink composition for writing instruments is an aqueous ink composition for writing instruments containing at least a pigment (a) and colored resin particles (A) encapsulating the pigment (a).
Claims7
A writing instrument comprising an aqueous ink composition, the aqueous ink composition comprising:
- an unencapsulated pigment (a);
- and
- colored resin particles (A) encapsulating a pigment of the same kind as the unencapsulated pigment (a) and a synergist of the pigment in the colored resin particles (A),
- wherein the unencapsulated pigment (a) is present in a range of from 0.1 to 8 mass % with respect to a total aqueous ink composition mass,
- wherein an (a)/(A) content ratio of the unencapsulated pigment (a) to the colored resin particles (A) encapsulating the pigment is in a range of from 0.02 to 0.4 by mass, and
- wherein the pigment is a carbon black and the synergist is a phthalocy anine pigment derivative.
Dependencies are inferred from the claim text.