Liquid composition, recording liquid, liquid catridge, liquid ejection cartridge, liquid ejection unit and method of liquid ejection

Abstract

Since an ink (2) contains a hydrophobic colloid which will be charged with a positive zeta potential when the pH of the ink (2) is within a range of over 4 and under 6, it is possible to limit silicon or silicon compound from being eluted into the ink (2) from a circuit board (44) formed from a silicon wafer or the like. Thus, it is possible to prevent the silicon or silicon compound, if eluted into the ink (2), from being deposited on a resistance heater (48) and causing “cogation”, or to prevent the silicon or silicon compound from being deposited in an ink channel (42) and nozzle (45a) to clog the nozzle. Therefore, the ink (2) will not cause any non-spraying of the ink.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid composition that flows through a predetermined channel, a recording liquid for making recording to an object, a liquid cartridge containing the recording liquid, a liquid spraying cartridge that sprays the recording liquid contained in the liquid cartridge, and a liquid spraying apparatus and method. [0002] This application claims the priority of the Japanese Patent Application No. 2003-15979 filed on Jan. 24, 2003 and No. 2004-3447 filed on Jan. 8, 2004, the entireties of which are incorporated by reference herein. BACKGROUND ART [0003] It is well known to supply a liquid composition, through a fine-structure channel, to a liquid chamber provided with an energy-producing means such as a piezoelectric element, resistance heater or the like and pressurize the liquid composition thus supplied under an energy produced by the energy-producing means for spraying as droplets from a spray nozzle provided at the liquid chamber...

AI Technical Summary

Benefits of technology

[0019] Accordingly, the present invention has an object to overcome the above-mentioned drawbacks of the related art by providing a liquid composition into which silicon is prevented from being eluted, whereby a silicon-containing material can be prevented from depositing in the liquid and clogging a channel or spray nozzle, recording liquid using the liquid composition, a liquid cartridge containing the recording liquid, a liquid spraying cartridge housing the liquid cartridge, and a liquid spraying apparatus and method in which the recording liquid contained in the liquid spraying cartridge is used to assure a high quality of printed images.

[0020] The Inventors of the present invention completed the present invention capable of overcoming the above-mentioned drawbacks of the related art by finding that it is possible to prevent silicon or silicon compound from being eluted from a silicon-containing material into liquid which is to flow through a channel in which a silicon-containing material is exposed by including, in the liquid, a hydrophobic colloid which is not included as impurity as far as possible in any conventional ink used to make recording to an object such as paper or the like, more specifically, by including, in the liquid, a hydrophobic colloid that will be charged with a positive zeta potential when the liquid's pH is controlled to a range of over 4 and under 6.

[0028] According to the present invention, the liquid flowing through the channel in which the silicon-containing material is exposed contains at least the hydrophobic colloid that is charged with a positive zeta potential when the pH of the liquid is controlled to a range of over 4 and under 6. Thus, it is possible to prevent silicon or silicon compound from being eluted from the silicon-containing material into the liquid.

Problems solved by technology

However, the process of production will make it difficult to oxidize the end face of the silicon wafer and the silicon or silicon oxide will be eluted into the ink if it is exposed to the ink as the case may be.

If the metallic portions of the had tip are so oxidized, melting of the silicon wafer will lower the dimensional accuracy of the head tips, leading to deterioration of the ink spraying performance, quality deterioration of images formed on the paper, non-spraying of the ink and other troubles as the case may be.

Also, the silicon elution from the silicon wafer will lower the bonding strength at the junction between the silicon wafer and other parts joined to the silicon wafer, so that the other parts will be separated from the silicon wafer, which will possibly damage the head tips.

In case the ink chamber and channel are formed from the silicon wafer, such silicon elution from the silicon wafer will lower the dimensional accuracy of the chamber and channel, possibly resulting in deterioration of the spraying performance of the had tip.

In the ink having the silicon or silicon oxide eluted therein, the stability of dye dispersion is lost so that the dye will possibly deposit and clog the nozzle.

As the ink solvent evaporates, the silicon or silicon oxide eluted in the ink will cause super-saturation of the ink and deposit in the ink and clog the nozzle to possibly cause non-spraying of the ink.

Also, the silicon or silicon oxide eluted in the ink will have the solubility thereof increased in the ink heated around the resistance heater and will thus melt excessively in the ink, and deposit on the resistance heater due to rapid cooling after the ink is sprayed.

In the head tip in which the “cogation” has thus occurred on the resistance heater, it will be difficult to heat the ink appropriately, causing the non-spraying of the ink.

The above proposals permit to prevent the silicon or silicon oxide from being eluted from the silicon wafer into the ink, but they are not advantageous in that the number of steps of producing the head tips is increased, resulting in an increased manufacturing cost and lower yield.

The printer product including the head tips will be very expensive.

Also, in case a layer is provided on the surface of the silicon wafer as above, there is no pin hole and it is difficult to form the layer to a generally uniform thickness, which will also lower the yield.

The aforementioned troubles will arise not only in case the silicon wafer is used to form the head tips but in case the head tips in which the silicon-containing material such as a glass substrate is exposed are in contact with the ink, namely, in case the silicon-containing material is exposed in a channel in which alkaline ink flows.

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