Thermal ink-jet ink and ink cartridge using the same

• US 20070109372A1
• Filed: 01/03/2007
• Published: 05/17/2007
• Est. Priority Date: 07/08/2005
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tomioka, Hiroshi, Yamakami, Hideki
• Granted Patent: US 7,883,185 B2
• Time in Patent Office: Days
• US Class Current: 347/86
• CPC Class Codes: B41J 2/14072 Electrical connections, e.g. details on electrodes, connecting the chip to the outside...
• CPC Class Codes: B41J 2/1603 of the front shooter type
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/17536 Protection of cartridges or parts thereof, e.g. tape
• CPC Class Codes: C09D 11/38 characterised by non-macromolecular additives other than solvents, pigments or dyes
• CPC Class Codes: C09D 11/40 Ink-sets specially adapted for multi-colour inkjet printing

Abstract

There is provided an ink cartridge including: a thermal ink-jet head provided with a heat generating portion that generates thermal energy for ejecting ink from an ejection opening, and contains the ink. In the ink cartridge, the heat generating portion has, at its surface in contact with the ink, a protective layer containing at least one selected from the group consisting of a silicon oxide, a silicon nitride, and a silicon carbide; and the ink contains at least one of a polyvalent carboxylic acid and a salt thereof, and the total content of the polyvalent carboxylic acid and the salt thereof is in the range of from 0.001 mmol/l or more to 0.5 mmol/l or less. The ink cartridge shows a small change in driving pulse and a small change in image to be outputted, and provides sufficient ejection property and sufficient printing durability.

Claims

1. An ink cartridge comprising a thermal ink-jet head provided with a heat generating portion that generates thermal energy for ejecting ink from an ejection opening, and storing the ink, wherein:

the heat generating portion has, at its surface in contact with the ink, a protective layer containing at least one selected from the group consisting of a silicon oxide, a silicon nitride, and a silicon carbide; and

the ink contains at least one of a polyvalent carboxylic acid and a salt thereof, and a total content of the polyvalent carboxylic acid and the salt thereof is in a range of from 0.001 mmol/l or more to 0.5 mmol/l or less.

2. The ink cartridge according to claim 1, wherein the protective layer has a thickness in a range of from 50 nm or more to 500 nm or less, and the total content of the polyvalent carboxylic acid and the salt thereof in the ink stored in the ink cartridge is in a range of from 0.01 mmol/l or more to 0.2 mmol/l or less.

3. The ink cartridge according to claim 1, wherein the thermal ink-jet head has an ink liquid chamber, and a ratio of a volume of the ink liquid chamber to a surface area of a part of the protective layer in contact with the ink is 50 μ

m³/μ

m² or less.

4. The ink cartridge according to claim 1, wherein the ink cartridge stores plural inks, and a difference between a maximum value and a minimum value of total contents of a polyvalent carboxylic acid and a salt thereof in the respective inks is 0.3 mmol/l or less.

5. The ink cartridge according to claim 1, wherein the polyvalent carboxylic acid and the salt thereof comprise citric acid and a salt of citric acid.

6. The ink cartridge according to claim 1, wherein the ejection opening and the heat generating portion are oppositely disposed.

7. An ink for a thermal ink-jet head provided with a heat generating portion that generates thermal energy for ejecting the ink from an ejection opening, the heat generating portion having, at its surface in contact with the ink, a protective layer containing at least one selected from the group consisting of a silicon oxide, a silicon nitrite, and a silicon carbide;

comprising

at least one of a polyvalent carboxylic acid and a salt thereof, and

a total content of the polyvalent carboxylic acid and the salt thereof is in a range of from 0.001 mmol/l or more to 0.5 mmol/l or less.