EP0778325A2
Expired / Lapsed
EP
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Aqueous black ink composition for writing board
Assignee: Orient Chemical Industries Ltd
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Filing: 1996-12-03
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Granted: —
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Expires: 2016-12-03
Abstract
Abstract The present invention provides an aqueous black ink composition for a writing board which hardly causes thickening, coagulation of the pigment, decreasing of writing density due to sedimentation, clogging in a penpoint, and break in writing. The aqueous black ink composition comprises water, the oxidized carbon black obtained by oxidizing carbon black using hypohalogenous acid and/or salt thereof, a film forming agent, and a release agent.
Inventors
- 👤 Toshiyuki Nagasawa
- 👤 Tetsuji Kihara
- 👤 Sohko Itoh
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 06:39
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
35 words
An aqueous black ink composition for a writing board comprising water, an oxidized carbon black obtainable by oxidizing carbon black using hypohalogenous acid and/or a salt thereof, a film forming agent, and a release agent.
Claim 2
Dependent Claim
30 words
The aqueous black ink composition for a writing board according to claim 1, wherein the oxidized carbon black has a surface active hydrogen content of not less than 1.5 mmol/g.
Claim 3
Dependent Claim
34 words
The aqueous black ink composition for a writing board according to claim 1 or 2, wherein the carbon black has an oil absorption of according to JIS-K6221 of not more than 150 ml/100 g.
Claim 4
Dependent Claim
33 words
The aqueous black ink composition for a writing board according to any of claims 1 to 3, wherein the oxidized carbon black has an average particle size of not more than 300 nm.
Claim 5
Dependent Claim
35 words
The aqueous black ink composition for a writing board according to any of claims 1 to 4, wherein the oxidized carbon black has an alkaline metal salt of an acidic group on the surface thereof.
Claim 6
Dependent Claim
43 words
The aqueous black ink composition for a writing board according to any of claims 1 to 5, wherein the oxidized carbon black is contained in an amount of from 0.5 to 20% by weight based on the total amount of the ink composition.
Claim 7
Dependent Claim
62 words
A process for producing an aqueous black ink composition for a writing board comprising: mixing carbon black with water; oxidizing the carbon black in water using hypohalogenous acid and/or salt thereof as an oxidizing agent; adding a film forming agent, a release agent and additives to the aqueous dispersion of the oxidized carbon black; and stirring until the resulting dispersion becomes uniform.
Claim 8
Dependent Claim
82 words
A process for producing an aqueous black ink composition for a writing board comprising: mixing carbon black with water; stirring the resulting mixture until the carbon black particles have an average particle size of not more than 300 nm; oxidizing the carbon black in water using hypohalogenous acid and/or salt thereof as an oxidizing agent; adding a film forming agent, a release agent and additives to the aqueous dispersion of the oxidized carbon black; and stirring until the resulting dispersion becomes uniform.
Claim 9
Dependent Claim
38 words
The process for forming an aqueous black ink composition for a writing board according to claim 7 or 8, wherein the carbon black has an oil absorption of according to JIS-K6221 of not more than 150 ml/100 g.
Claim 10
Dependent Claim
40 words
The process for forming an aqueous black ink composition for a writing board according to any of claims 7 to 9, wherein the hypohalogenous acid and/or salt thereof is selected from the group consisting of sodium hypochlorite and potassium hypochlorite.
References Cited (Backward Citations)
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