Aqueous ink composition for writing instruments and writing instrument containing the same

JP2025167942APending Publication Date: 2025-11-07PILOT PEN CO LTD
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Patent Information

Application Number
JP2024072971
Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-04-26
Publication Date
2025-11-07

AI Technical Summary

Technical Problem

Existing water-based inks with dyes as colorants exhibit fast penetration into paper, leading to show-through and bleed-through, and are unsuitable for low-viscosity inks, while those with pigments as colorants lack quick-drying properties when used in writing instruments.

Method used

An aqueous ink composition containing a polyoxyalkylene branched alkyl ether with an HLB value of 16 to 20, along with a dye, is formulated to provide quick-drying properties without bleed-through, suitable for low-viscosity inks, and is incorporated into writing instruments with specific structural features to maintain ink stability.

Benefits of technology

The ink composition achieves rapid drying on the paper surface, preventing show-through and bleed-through, and ensures stable ink ejection and flow in writing instruments, particularly fountain pens, without altering viscosity or surface tension.

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Patent Text Reader

Abstract

To provide a highly convenient aqueous ink composition and a writing instrument containing the same, where the composition is capable of imparting quick-drying performance without causing bleed-through of written traces even when a dye is used as a colorant, and is applicable to low-viscosity inks.SOLUTION: An aqueous ink composition for writing instruments comprises a dye, water, and a polyoxyalkylene-branched alkyl ether, where the polyoxyalkylene-branched alkyl ether has the structure represented by general formula (1) described in the specification and has an HLB value greater than 16 and less than or equal to 20. A writing instrument contains the composition.SELECTED DRAWING: None
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Citation Information

Patent Citations

  • Ink composition for water-based ballpoint pen and water-based ballpoint pen

    JP2006193688A

  • Water-based ink composition for writing utensil, and writing utensil using the same

    JP2019116602A

  • Water-based ink composition for writing instrument, and writing instrument, brush pen and brush pen ink cartridge incorporating the same

    JP2022132011A