Aqueous gel ink-filled ball point pen

• US 5,993,098 A
• Filed: 12/12/1997
• Issued: 11/30/1999
• Est. Priority Date: 12/12/1996
• Status: Expired due to Term

• Current Assignee: Mitsubishi Pencil Kabushiki Kaisha
• Original Assignee: Mitsubishi Pencil Kabushiki Kaisha
• Inventors: Osada, Takahiro
• Primary Examiner(s): Walczak, David J.
• Assistant Examiner(s): Prunner, Kathleen J.
• Application Number:
  US08/990,160
• Time in Patent Office: 718 Days
• Field of Search: 401/209, 401/216
• US Class Current: 401/209
• CPC Class Codes: B43K 7/01 for low viscosity liquid ink

Abstract

Provided is an aqueous gel ink-filled ball point pen having less blobbing and capable of drawing stable lines having vivid color and no uneven written intensity. The aqueous gel ink-filled ball point pen has a ball of a diameter of 0.3 to 2.0 mm at a tip point with an aqueous gel ink having a viscosity ratio (a value of (viscosity at 10 rpm)/(viscosity at 50 rpm) measured by means of an E type rotational viscometer) of 1.1 to 4.0 and controlled an ink lay down value according to JIS Standard S6053 to 50 to 200 mg/m.

Claims

1. An aqueous gel ink-filled ball point pen in which the ball point pen having a ball with a diameter of 0.3 to 2.0 mm at a tip point thereof is charged with an aqueous gel ink having a viscosity ratio (a value of (viscosity at 10 rpm)/(viscosity at 50 rpm) measured by means of an E type rotational viscometer) of 1.1 to 4.0 and an ink lay down value according to JIS Standard S6053 is controlled to 50 to 200 mg/100 m.

2. The aqueous gel ink-filled ball point pen charged with an aqueous gel ink as claimed in claim 1, wherein said aqueous gel ink comprises an aqueous medium comprising a water soluble organic solvent.

3. The aqueous gel ink-filled ball point pen charged with an aqueous gel ink as claimed in claim 2, wherein said water soluble organic solvent comprises a compound selected from the group consisting of alkylene glycols, polyalkylene glycols, triols, glycerols, thiodiethanol, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone.

4. The aqueous gel ink-filled ball point pen charged with an aqueous gel ink as claimed in claim 3, wherein the water soluble organic solvent comprises propylene glycol.

5. The aqueous gel ink-filled ball point pen charged with an aqueous gel ink as claimed in claim 1, said aqueous gel ink further comprising a pseudo-plasticizer selected from natural resins consisting of xanthan gum, tamarind gum, carrageenan gum, tragacanth gum, locust bean gum, gum arabic, guar gum, curdlan, pectin, agar, gelatin, mannans, and cellulose, and from acrylic synthetic polymers, urethane synthetic polymers, smectite, and montmorillonite.

6. The aqueous gel ink-filled ball point pen charged with an aqueous gel ink as claimed in claim 5, wherein said pseudo-plasticizer is a cellulose selected from the group consisting of methyl cellulose, ethyl cellulose and carboxymethyl cellulose.

7. The aqueous gel ink-filled ball point pen charged with an aqueous gel ink as claimed in claim 6, wherein said cellulose is carboxymethylcellulose.

8. The aqueous gel ink-filled ball point pen charged with an aqueous gel ink as claimed in claim 5, wherein said resins are selected from the group consisting of carboxymethyl cellulose and xanthan gum.