Aqueous ink composition for ball-point pen

• US 6,275,816 B1
• Filed: 08/26/1999
• Issued: 08/14/2001
• Est. Priority Date: 03/17/1999
• Status: Expired due to Fees

• Current Assignee: Kotobuki & Co., Ltd.
• Original Assignee: Kotobuki & Co., Ltd.
• Inventors: Nakamura, Akio, Hattori, Katsuya, Morishita, Mikio
• Primary Examiner(s): Acquah, Samuel A.
• Application Number:
  US09/383,980
• Time in Patent Office: 719 Days
• Field of Search: 106/14.11, 106/14.13, 106/14.34, 106/14.41, 106/31.13, 106/31.25, 106/31.28, 106/31.31, 106/31.36, 106/31.37, 106/31.39, 106/31.4, 106/31.43, 106/31.44, 106/31.55, 106/31.59, 524/27, 524/28, 524/31, 524/47, 524/55, 524/56, 524/77, 524/81, 524/276
• US Class Current: 106/31.13
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C09D 105/00 Coating compositions based on polysaccharides or on their derivatives, not provided for in groups C09D101/00 or C09D103/00
• CPC Class Codes: C09D 105/04 Alginic acid; Derivatives thereof
• CPC Class Codes: C09D 11/18 specially adapted for ball-point writing instruments

Abstract

A aqueous ink for a ball-point pen which is stable over time and has high pigment dispersion stability, includes a pigment, a water-soluble organic solvent, water, xanthane gum of about 0.01 to about 0.2 wt. % and a sodium alginate of about 0.2 to about 0.6 wt. % of a total amount of the ink.

Claims

1. An aqueous ink for a ball-point pen, comprising:

a pigment;

a water-soluble organic solvent; and

water;

wherein said aqueous ink comprises xanthane gum of substantially about 0.01 to about 0.2 wt. % and an ionic polysaccharide of substantially about 0.2 to about 0.6 wt. %, other than xanthane gum, in a total amount of the ink.

2. The aqueous ink as claimed in claim 1, wherein said ionic polysaccharide, other than xanthane gum, comprises a sodium alginate.

3. The aqueous ink as claimed in claim 1, wherein a water content is substantially about 35 to about 49 wt. % in the total amount of the ink.

4. The aqueous ink as claimed in claim 2, wherein a water content is substantially about 35 to about 49 wt. % in the total amount of the ink.

5. The aqueous ink as claimed in claim 1, wherein said ionic polysaccharide, other than xanthane gum, is at least one substance selected from the group consisting of a natural Arabic gum, casein, gelatin carrageenan, alginic acid, semi-synthetic carboxymethyl cellulose, sodium caboxymethylstarch, synthetic sodium polyacrylate, and polyacrylic acid.

6. The aqueous ink as claimed in claim 3, wherein said ionic polysaccharide, other than xanthane gum, is at least one substance selected from the group consisting of a natural Arabic gum, casein, gelatin, carrageenan, alginic acid, semi-synthetic carboxymethyl cellulose, sodium carboxymethylstarch, synthetic sodium polyacrylate, and polyacrylic acid.

7. The aqueous ink as claimed in claim 1, wherein said pigment comprises an inorganic pigment.

8. The aqueous ink as claimed in claim 2, wherein said pigment comprises an inorganic pigment.

9. The aqueous ink as claimed in claim 1, wherein said pigment comprises an organic pigment.

10. The aqueous ink as claimed in claim 2, wherein said pigment comprises an organic pigment.

11. The aqueous ink as claimed in claim 7, wherein said inorganic pigment is at least one substance selected from the group consisting of titanium oxide, carbon black, and metal powder.

12. The aqueous ink as claimed in claim 8, wherein said inorganic pigment is at least one substance selected from the group consisting of titanium oxide, carbon black, and metal powder.

13. The aqueous ink as claimed in claim 9, wherein said organic pigment is at least one substance selected from the group consisting of azo-lake, insoluble azo-pigment, chelate azo-pigment, phthalocyanine pigment, perylene and perinone pigments, anthraquinone pigment, quinacridone pigment, lake pigment, nitro pigment, and nitroso-pigment.

14. The aqueous ink as claimed in claim 10, wherein said organic pigment is at least one substance selected from the group consisting of azo-lake, insoluble azo-pigment, chelate azo-pigment, phthalocyanine pigment, perylene and perinone pigments, anthraquinone pigment, quinacridone pigment, dye-rake, nitro pigment, and nitroso-pigment.

15. The aqueous ink as claimed in claim 1, wherein a content of said pigment is substantially within the range of about 4 to about 12 wt. %.

16. The aqueous ink as claimed in claim 15, wherein a content of said pigment is substantially within the range of about 6 to about 8 wt. %.

17. The aqueous ink as claimed in claim 2, wherein a content of said pigment content is substantially within the range of about 4 to about 12 wt. %.

18. The aqueous ink as claimed in claim 17, wherein a content of said pigment is substantially within the range of about 6 to about 8 wt. %.

19. The aqueous ink as claimed in claim 1, wherein said water-soluble organic solvent comprises at least one substance selected from a group consisting of glycerin, diglycerin, ethylene glycol, diethylene glycol, tridiethylene glycol, propylene glycol, polythene glycol, polypropylene glycol, thiodiglycol, 1-3-butylene glycol, 2-pyrrolidone, n-methyl-2-pyrrolidone, dimethylformamide, and dimethylimidazolidinone.

20. The aqueous ink as claimed in claim 2, wherein said water-soluble organic solvent is at least one substance select from the group consisting of glycerin, diglycerin, ethylene glycol, diethylene, glycol, tridiethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol, 1-3-butylene glycol, 2-pyrrolidone, n-methyl-2-pyrrolidone, dimethylformamide, and dimethylimidazolidinone.

21. The aqueous ink as claimed in claim 1, further including at least one of a surface active agent, an antiseptic agent, a pH adjuster, an anticorrosion agent, and a dispersion agent.

22. The aqueous ink as claimed in claim 2, further including at least one of a surface active agent, an antiseptic agent, a pH adjuster, an anticorrosion agent, and a dispersion agent.

23. The aqueous ink according to claim 21, wherein said pH adjuster includes at least one of monoethanol amine, diethanol amine, triethanol amine, sodium hydroxide, lithium hydroxide, potassium hydroxide, sodium tripolyphosphate, sodium carbonate, urea, and ammonia.

24. The aqueous ink according to claim 21, wherein said anti-corrosion agent includes at least one of tolytriazole, benzotriazole and its derivatives, fatty acid phosphorous derivatives including any of octyl phosphate, dioctyl thiophosphate, imidazole, benzomidazole and its derivative, 2-mercaptobenzothiazole, octyl methane sulfonic acid, dicyclohexyl ammonium nitrate, diisopropyl ammonium nitrate, propargyl alcohol, and dialkylthio urea.

25. The aqueous ink according to claim 21, wherein said antiseptic agent includes at least one phenol, isopropyl methyl phenol, penta chlorophenol sodium, benzoic acid, sodium benzoate, dehydroacetic acid, sodium dehydroacetate, sorbic acid, potassium sorbate, 2-pyridinethiol-1 oxide sodium salt, 1,2-benzoisothiazoline-3-one, 5-chlor-2-methyl-4-isothizoline-3-one, 2,4-thiazolylbenzimidazole, and p-hydroxybenzoate ester.

26. The aqueous ink according to claim 21, wherein said surface active agent includes at least one of potassium linoleic acid, potassium oleate, sodium oleate, polyoxy ethylene alkylether phosphate, polyoxy ethylene alkyl phenyl ether, and polyoxy ethylene lanolin.

27. The aqueous ink according to claim 1, wherein said water-soluble organic solvent comprises ethylene glycol and a content of said ethylene glycol is substantially not less than about 11 wt. %.

28. The aqueous ink according to claim 2, wherein said water-soluble organic solvent comprises ethylene glycol and a content of said ethylene glycol is substantially not less than about 11 wt. %.