Aqueous gel ink-filled ball point pen

• US 6,390,710 B1
• Filed: 09/05/2001
• Issued: 05/21/2002
• Est. Priority Date: 03/09/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Pencil Kabushiki Kaisha
• Original Assignee: Mitsubishi Pencil Kabushiki Kaisha
• Inventors: Miyamoto, Masaru
• Primary Examiner(s): Eloshway, Charles R.
• Application Number:
  US09/947,191
• Publication Number:
  US 20020071709A1
• Time in Patent Office: 258 Days
• Field of Search: 401/209, 401/216, 401/215, 106/31.28, 106/31.6
• US Class Current: 401/215
• CPC Class Codes: C09D 11/18 specially adapted for ball-point writing instruments

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 0.6 to 2.0 mm at a tip point with an aqueous gel ink containing a pigment whose specific gravity is 2 or more and 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 3.0 to 5.0, and an ink lay down value according to JIS Standard S6053 which is controlled to 220 to 800 mg/m.

Claims

1. An aqueous gel ink-filled ball point pen which has a ball of a diameter of 0.6 to 2.0 mm at the tip point thereof and is charged with an aqueous gel ink comprising a pigment, said pigment having a specific gravity of 2 or more;

said gel ink having a viscosity ratio of 3.0 to 4.30, wherein said viscosity ratio (viscosity at 10 rpm)/(viscosity at 50 rpm) is measured by means of an E type rotational viscometer, and an ink lay down value according to JIS Standard S6053 of from 220 to 780 mg/100 m.