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 ( 45 a ) to clog the nozzle. Therefore, the ink ( 2 ) will not cause any non-spraying of the ink.

1 . A liquid composition which is to flow through a channel in which a silicon-containing material is exposed, the composition containing: 
 a solvent; and    a hydrophobic colloid that is charged with a positive zeta position when the pH of the composition is controlled to a range of over 4 and under 6.    
     
     
         2 . The composition according to  claim 1 , wherein the hydrophobic colloid contains one or a mixture of more than one, selected from alumina, cerium oxide, barium oxide and iron hydroxide.  
     
     
         3 . The composition according to  claim 1 , further containing more than 3 ppm of he hydrophobic colloid.  
     
     
         4 . A recording liquid which is guided to a nozzle through a channel in which a silicon-containing material is exposed, and sprayed as droplets from the nozzle for adhesion to an object, the liquid containing: 
 a pigment;    a solvent in which the pigment is dispersed; and    a 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.    
     
     
         5 . The liquid according to  claim 4 , wherein the hydrophobic colloid contains one or a mixture of more than one, selected from alumina, cerium oxide, barium oxide and iron hydroxide.  
     
     
         6 . The liquid according to  claim 4 , further containing more than 3 ppm of he hydrophobic colloid.  
     
     
         7 . A liquid cartridge including a spraying means for spraying, as droplets from the nozzle, a recording liquid guided to a nozzle through a channel in which a silicon-containing material is exposed, 
 the cartridge being to be housed removably in a spraying means of a liquid spraying apparatus which sprays the liquid as droplets for adhesion to an object, and serve as a source of the recording liquid for the spraying means of the liquid spraying apparatus; and    the recording liquid containing:    a pigment;    a solvent in which the pigment is dispersed; and    a 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.    
     
     
         8 . The cartridge according to  claim 7 , wherein the hydrophobic colloid contains one or a mixture of more than one, selected from alumina, cerium oxide, barium oxide and iron hydroxide.  
     
     
         9 . The cartridge according to  claim 7 , further containing more than 3 ppm of he hydrophobic colloid.  
     
     
         10 . A liquid spraying cartridge which is to be housed removably in a liquid spraying apparatus which sprays a recording liquid for adhesion to an object to make recording to the object, the cartridge comprising: 
 a liquid container which contains a recording liquid; and    a spraying means which guides the recording liquid from the liquid container to a nozzle via a channel in which a silicon-containing material is exposed and sprays the recording liquid as droplets from the nozzle, the recording liquid containing:    a pigment;    a solvent in which the pigment is dispersed; and    a 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.    
     
     
         11 . The cartridge according to  claim 10 , wherein the hydrophobic colloid contains one or a mixture of more than one, selected from alumina, cerium oxide, barium oxide and iron hydroxide.  
     
     
         12 . The cartridge according to  claim 10 , further containing more than 3 ppm of he hydrophobic colloid.  
     
     
         13 . The cartridge according to  claim 10 , wherein the silicon-containing material is a silicon wafer.  
     
     
         14 . The cartridge according to  claim 10 , wherein the nozzles are arrayed in a nearly straight line.  
     
     
         15 . A liquid spraying apparatus which makes recording to an object by making a recording liquid adhere to the object, the apparatus comprising: 
 a spraying means for spraying, as droplets from the nozzle, the recording liquid, guided to a nozzle via a channel in which a silicon-containing material is exposed; and    a liquid cartridge serving a source of the recording liquid for the spraying means,    a liquid container which contains a recording liquid,    the recording liquid containing: 
 a pigment;  
 a solvent in which the pigment is dispersed; and  
 a 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.  
   
     
     
         16 . The apparatus according to  claim 15 , wherein the hydrophobic colloid contains one or a mixture of more than one, selected from alumina, cerium oxide, barium oxide and iron hydroxide.  
     
     
         17 . The apparatus according to  claim 15 , further containing more than 3 ppm of he hydrophobic colloid.  
     
     
         18 . The apparatus according to  claim 15 , wherein the silicon-containing material is a silicon wafer.  
     
     
         19 . The apparatus according to  claim 15 , wherein the nozzles are arrayed in a nearly straight line.  
     
     
         20 . A liquid spraying method for a liquid spraying apparatus which makes recording to an object by making a recording liquid adhere to the object, wherein: 
 the recording liquid contains: 
 a pigment;  
 a solvent in which the pigment is dispersed; and  
 a 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; and  
   the recording liquid is guided to a nozzle via a channel in which a silicon-containing material is exposed, and sprayed as droplets from the nozzle.    
     
     
         21 . The method according to  claim 20 , wherein the hydrophobic colloid contains one or a mixture of more than one, selected from alumina, cerium oxide, barium oxide and iron hydroxide.  
     
     
         22 . The method according to  claim 20 , wherein the recording liquid further contains more than 3 ppm of he hydrophobic colloid.