# US 10,501,649 B2 · Aqueous ink composition for writing instruments

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,501,649 B2
- Document ID: US10501649B2
- Status: Granted
- Kind: B2
- Application number: 15/550,189
- Filed: 2016-02-18
- Published: 2018-01-18
- Granted: 2019-12-10
- Earliest claimed: 2015-02-19
- Assignees: Mitsubishi Pencil Company, Limited
- Applicants: Mitsubishi Pencil Company, Limited
- Inventors: Hisato Haga
- Web page: https://patentgrep.com/patent/US10501649B2

## CPC

- C09D 11/16: Writing inks
- B43K 5/00: Pens with ink reservoirs in holders, e.g. fountain-pens (nibs or writing-points with ink reservoirs B43K1/01; ball-point pens B43K7/00; pens with writing-points other than nibs or balls B43K8/00; multiple-point writing implements B43K27/00)
- B43K 7/00: Ball-point pens ({B43M11/085 takes precedence}; multiple-point writing implements B43K27/00)
- B43K 8/00: Pens with writing-points other than nibs or balls (brushes with reservoir for supplying substances A46B11/00)
- B43K 8/024: {with writing-points comprising felt}
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- B43K: IMPLEMENTS FOR WRITING OR DRAWING (containers, casings or accessories for cosmetic substances, e.g. shaving soap, lipstick, make-up A45D34/00, A45D40/00)

## Abstract

Provided is an aqueous ink composition for a writing instrument which is excellent in a drying property of drawn lines and a low temperature stability of the ink while inhibiting the pen tip from drying and which prevents the drawn lines from causing feathering and strike-through. The aqueous ink composition for a writing instrument described above contains at least a colorant, trimethylglycine, pentaerythritol, 10% by mass or less of a water-soluble organic solvent and water.

## Claims

### Claim 1

An aqueous ink composition for a writing instrument containing at least a colorant, 1.5 to 11% by mass of trimethylglycine, 1.5 to 5.5% by mass of pentaerythritol, 10% by mass or less of a water-soluble organic solvent, based on a total amount of the ink composition, and water.

### Claim 2 (depends on 1)

A writing instrument charged with the aqueous ink composition for a writing instrument as described in claim 1.