JP5659616B2 - Liquid stirring device - Google Patents

Description

  The present invention relates to a liquid stirring apparatus.

  2. Description of the Related Art Conventionally, an ink supply system that supplies ink to an ejection head that can eject ink from an ink tank that contains ink via an ink supply pipe is known. When such an ink supply system is used, if ink is not supplied for a long time after ink is supplied to the ejection head, components contained in the ink remaining in the flow path of the ink supply pipe May settle. If the component contained in the ink settles, when supplying ink to the ejection head again, the ink may not be stably supplied to the ejection head, or ejection failure may occur.

  In particular, when an inorganic pigment (for example, titanium oxide) or a metal pigment (for example, aluminum) is included as an ink component, there is a problem that these pigments are liable to settle due to a difference in specific gravity from the solvent. .

  To deal with this problem, for example, Patent Document 1 describes an ink supply system provided with a sub tank that always holds a fixed amount of ink in an ink flow path. Japanese Patent Application Laid-Open No. H10-228561 describes that a stirring ball is provided in the sub tank in order to stir the ink in the sub tank. By providing such a subtank, sedimentation of components such as pigments contained in the ink can be reduced.

JP 2006-272648 A

  However, in the prior art of Patent Document 1, the stirring sphere becomes difficult to move in the sub-tank, and the liquid stirring efficiency may be reduced.

  One of the objects according to some aspects of the present invention is to provide a liquid stirring device having excellent liquid stirring efficiency and a liquid discharging device that is less likely to cause defective discharge by solving the above-described problems. There is.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1] One aspect of the liquid stirring apparatus according to the present invention is a liquid storage unit that stores a liquid containing a component that can settle, a container that is filled with the liquid from the liquid storage unit, A liquid supply apparatus comprising: a stirrer that is contained inside the container and that stirs the liquid; and a bottom part that moves the stirrer, and the top part of the container constitutes the inside of the container, The relationship between the height (Ht) in the vertical direction of the middle region inside the container and the height (Hb) in the vertical direction of the stirrer satisfies the following formula (1): A liquid stirring device.
0.40 × Ht ≦ Hb ≦ 0.90 × Ht (1)

  According to the invention described in Application Example 1, when Ht and Hb satisfy the above relational expression, a stirrer can easily move in the container, and a liquid stirring device having excellent liquid stirring efficiency can be obtained. Can do.

Application Example 2 The liquid stored in the liquid storage unit has a predetermined concentration, the height (Hi) in the vertical direction of the sediment of the component contained in the liquid in the container, The liquid stirring apparatus according to application example 1, wherein the relationship between Ht and the Hb satisfies the following formulas (2-1) and (2-2).
Hi ÷ Ht ≦ 0.26 (2-1)
2.50 × Hi ≦ Hb ≦ 0.90 × (Ht−Hi) (2-2)

  According to the invention described in the application example 2, since Ht, Hb, and Hi satisfy the above relational expression, it is possible to perform stirring better, and even when the sediment is solidified, the liquid stirring excellent in liquid stirring efficiency A device can be obtained.

  Application Example 3 The bottom surface portion has a shape in which the stirrer is moved and is curved in a cross-sectional view in a direction perpendicular to the vertical direction and downward in the vertical direction. The liquid stirring apparatus according to Application Example 1 or 2.

  According to the invention described in the application example 3, the sedimented component is easily collected in the curved portion, and the stirring bar is moved around the curved portion, so that the stirring efficiency of the sedimented component is increased.

  Application Example 4 The container includes a side surface provided in a direction in which the stirrer is moved, and a connection portion between the side surface and the bottom surface is curved toward the outside of the container. The liquid agitating device according to any one of Application Examples 1 to 3, wherein the liquid agitating device is provided.

  According to the invention described in Application Example 4, since the gap near the connection portion becomes small, the stirrer can easily come into contact with the settled component, the settled component can be efficiently stirred, and the stirring efficiency is increased. .

The side view which shows typically the liquid stirring apparatus which concerns on this embodiment. The perspective view of the container of the liquid stirring apparatus which concerns on this embodiment. The figure explaining the middle region part of the container concerning this embodiment. FIG. 3 is a perspective view when the discharge head according to the present embodiment is a line-type discharge head. The figure which shows the modification of the liquid stirring apparatus which concerns on this embodiment. The figure which shows the modification of the liquid stirring apparatus which concerns on this embodiment. The figure which shows the relationship between the container which concerns on this embodiment, a stirring element, and a sediment. FIG. 3 is a diagram illustrating a liquid ejection apparatus according to the present embodiment.

  Hereinafter, although embodiment of this invention is described, this invention is not restrict | limited to these.

1. Liquid Stirring Device The liquid stirring device according to the present embodiment includes a container, a stirrer disposed inside the container, and a carriage. A liquid stirring apparatus 100 according to the present embodiment illustrated in FIG. 1 includes a liquid storage unit 10, a container 20, a liquid supply pipe 30, and a discharge head 33. The container 20 and the discharge head 33 are mounted on the carriage 50A. The container 20 includes a stirrer 15 therein. The carriage 50A can reciprocate in a predetermined direction MSD (hereinafter referred to as “longitudinal direction”).

1.1. Liquid storage part The liquid stirring apparatus 100 in this embodiment may have the liquid storage part 10. FIG. The liquid storage unit 10 stores a liquid containing a component having a predetermined concentration. In the present specification, the “predetermined concentration” refers to a concentration in a case where components that can settle in the liquid container 10 are sufficiently stirred. The liquid storage unit 10 shown in FIG. 1 is connected to the container 20 through a liquid supply pipe 30a. As a result, the liquid can flow into the container 20.

  The liquid in this specification should just contain the component which can settle, for example, dispersions, such as a suspension and an emulsion, etc. can be mentioned. Examples of the liquid stored in the liquid storage unit 10 include electrodes such as ink compositions, organic EL display materials, color filter materials such as liquid crystal displays, FED (surface emitting display) materials, and electrophoretic displays. Examples thereof include color filter materials and bioorganic materials used for biochip production.

  Further, “sedimentation” means that, when a liquid is left for a certain period of time, the contained components are precipitated and the contained components are accumulated in the lower layer of the liquid. For example, a component having a high specific gravity with respect to a solvent, and the ink composition can include, for example, one selected from inorganic pigments, metal pigments, and hollow resin particles, and is bonded or adsorbed thereto. Ingredients can be included.

  Examples of the inorganic pigment include titanium dioxide, silicon oxide, aluminum oxide, zinc oxide, iron oxide, and carbon black. Examples of the metal pigment include aluminum, gold, silver, copper, titanium and the like, or alloys thereof. Examples of the hollow resin particles include hollow resin particles described in specifications such as US Pat. No. 4,880,465 and Japanese Patent No. 3,562,754. In addition, the hollow resin particle has a cavity inside thereof, and its outer shell is formed from a resin having liquid permeability. The hollow resin particles can be used as a white pigment.

  Hereinafter, the white ink composition typically used as the liquid stored in the liquid storage unit 10 will be described. The white ink composition can include a resin for fixing the pigment. Examples of the resin include polyvinyl alcohol, polyethylene glycol, polyacrylic acid, polyurethane, polyacrylamide, and cellulose derivatives. In terms of product names, acrylic resins (for example, Almatex, manufactured by Mitsui Chemicals), urethane resins (for example, WBR-022U, manufactured by Taisei Fine Chemical Co., Ltd.) and the like can be mentioned.

  The white ink composition preferably contains one selected from alkanediols and glycol ethers. Alkanediols and glycol ethers can enhance the wettability of the recording surface such as the medium to be ejected to increase the ink permeability.

  Examples of the alkanediol include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, etc. , 2-alkanediol is preferred. Among these, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol having 6 to 8 carbon atoms are more preferable because of their particularly high permeability to the medium to be discharged.

  As glycol ethers, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol Mention may be made of lower alkyl ethers of polyhydric alcohols such as monomethyl ether, triethylene glycol monobutyl ether and tripropylene glycol monomethyl ether. Among these, good recording quality can be obtained by using triethylene glycol monobutyl ether.

  The white ink composition preferably contains an acetylene glycol surfactant or a polysiloxane surfactant. Acetylene glycol surfactants or polysiloxane surfactants can increase the wettability of a recording surface such as a medium to be ejected to increase the ink permeability.

  Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3, Examples include 5-dimethyl-1-hexyn-3-ol, 2,4-dimethyl-5-hexyn-3-ol, and the like. Commercially available acetylene glycol surfactants can be used. For example, Olphine (registered trademark) E1010, Olphine STG, Olphine Y (above, manufactured by Nisshin Chemical Co., Ltd.), Surfynol (registered trademark) 104 , 82, 465, 485, and TG (from Air Products and Chemicals Inc.).

  Commercially available products can be used as the polysiloxane surfactant, and examples thereof include BYK-347, BYK-348 (manufactured by BYK Japan).

  Further, the white ink composition may contain other surfactants such as an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant.

  The white ink composition preferably contains a polyhydric alcohol. For example, when the white ink composition is applied to an ink jet recording apparatus, the polyhydric alcohol can suppress drying of the ink and prevent clogging of the ink in the discharge head portion.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, and trimethylolethane. And trimethylolpropane.

  The white ink composition can contain water as a solvent. It is preferable to use pure water or ultrapure water such as ion exchange water, ultrafiltered water, reverse osmosis water, or distilled water. In particular, water obtained by sterilizing these waters by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria can be suppressed over a long period of time.

  Further, the white ink composition may be prepared by using a fixing agent such as water-soluble rosin, an antifungal agent / preservative such as sodium benzoate, an antioxidant / ultraviolet absorber such as allophanate, a chelating agent, triethanol, as necessary. Additives such as pH adjusters such as amines and oxygen absorbers can be contained. These additives can be used alone or in combination of two or more.

  Although the water-based ink composition has been described as an example of the white ink composition, an ultraviolet curable ink or the like may be used. In the case of using an ultraviolet curable ink, examples of components that can settle include a photopolymerization initiator.

1.2. Liquid Supply Pipe The liquid stirring apparatus 100 in this embodiment may have a liquid supply pipe 30. The liquid supply pipe 30 includes a liquid supply pipe 30a and a liquid supply pipe 30b. In FIG. 1, the liquid supply pipe 30 a connects the liquid storage unit 10 and the container 20, and allows the liquid stored in the liquid storage unit 10 to flow into the container 20. The liquid supply pipe 30 b connects the container 20 and the discharge head 33, and allows liquid to flow into the discharge head 33.

1.3. Container and Stir Bar The liquid stirrer 100 in this embodiment is mounted on the carriage 50A. When the liquid agitator 100 including the container 20 is mounted on the carriage 50A, it is not necessary to provide a separate mechanism for moving only the container 20, and the container 20 can be moved using the moving mechanism of the carriage 50A. it can.

  Moreover, the liquid stirring apparatus 100 in this embodiment has the stirring element 15 arrange | positioned inside the container 20 so that movement is possible, as shown in FIG.

  The shape of the stirrer 15 may be any shape that can move in the container 20. For example, a sphere, an ellipsoid (for example, a rugby ball type), a cylinder, an elliptic cylinder, a polygonal cylinder, a rectangular parallelepiped, a cube, a polyhedron Etc. Among these, when the shape of the stirrer 15 is a sphere or an ellipsoid, the stirrer 15 can be easily moved in the container 20 and the liquid can be efficiently stirred.

  As a material of the stirrer 15, glass mainly composed of silicate, aluminum oxide, zirconium oxide, metal (for example, aluminum, titanium, chromium, nickel, iron, or an alloy containing any of these) is used. Can be mentioned.

  The direction, angle, and the like in which the container 20 is attached are not particularly limited as long as the stirrer 15 moves in the container 20 based on the reciprocating motion of the carriage 50A.

  The shape of the container 20 of the liquid stirring apparatus 100 according to the present embodiment is not limited to a rectangular parallelepiped shape, a cylindrical shape, an elliptical cylindrical shape, or the like, and may be a cubic shape, a cylindrical shape, or the like. In the present specification, the shape of the container 20 refers to the internal shape of the container 20 in which the stirrer 15 is disposed.

As shown in FIG. 2A, the container 20 includes a bottom surface portion 22, a top surface portion 24 facing the bottom surface portion 22, and side surface portions 26 a, 26 b, 26 c connected to the bottom surface portion 22 and the top surface portion 24. 26d forms an enclosed shape. And it has the 1st side part 26a and the 2nd side part 26b which oppose by the longitudinal direction MSD shown in figure. The liquid supply tube 30a is connected to the first side surface portion 26a, and the liquid supply tube 30b is connected to the second side surface portion 26b. Furthermore, it has the 3rd side part 26c and the 4th side part 26d which oppose in the direction orthogonal to the direction MSD which moves the stirring element 15, and the perpendicular direction VD. The connection positions of the liquid supply pipe 30a and the first side face part 26a and the liquid supply pipe 30b and the second side face part 26b are not particularly limited, and the bottom face part 22, the upper face part 24, the third side face part 26c, It may be connected to any of the fourth side surface portions 26d. Further, both the liquid supply pipes 30a and 30b may be connected to the same surface of the container 20 described above.
For example, when the upper surface portion, the bottom surface portion, the third side surface portion, and the fourth side surface portion are integrated as shown in FIG. Part, bottom surface portion, third side surface portion, and fourth side surface portion.

  The middle part 18 which is an area where the stirrer 15 mainly moves will be described. The middle region portion in the present invention refers to a region surrounded by a bottom surface portion, a top surface portion, and a straight line connecting the bottom surface portion and the top surface portion in a cross-sectional view in the longitudinal direction of the container. Specifically, this will be described with reference to the drawings.

  In FIG. 3A, the container has a rectangular parallelepiped shape, and the first side surface portion 26a and the second side surface portion 26b do not have a curved shape. In this case, it is surrounded by the bottom surface portion 22, the top surface portion 24, a straight line connecting A1 of the bottom surface portion 22 and A2 of the top surface portion 24, and a straight line connecting B1 of the bottom surface portion 22 and B2 of the top surface portion 24. The region (the hatched region in FIG. 3A) corresponds to the middle region 18. That is, in the case of the shape as shown in FIG.

  Further, in FIG. 3B, unlike FIG. 3A, the first side surface portion 26a and the second side surface portion 26b are curved outward. In this case, it is surrounded by the bottom surface portion 22, the top surface portion 24, a straight line connecting A1 of the bottom surface portion 22 and A2 of the top surface portion 24, and a straight line connecting B1 of the bottom surface portion 22 and B2 of the top surface portion 24. The region (the hatched region in FIG. 3B) corresponds to the middle region 18. That is, the first side surface portion 26 a and the second side surface portion 26 b are not included in the middle region portion 18.

  Furthermore, in FIG.3 (c), the magnitude | size of the bottom face part 22 and the upper surface part 24 differs. Also in this case, the bottom surface portion 22, the top surface portion 24, the straight line connecting A1 of the bottom surface portion 22 and A2 of the top surface portion 24, and the straight line connecting B1 of the bottom surface portion 22 and B2 of the top surface portion 24 are surrounded. The region (the hatched region in FIG. 3C) corresponds to the middle region 18.

  In addition, as a preferable shape of the container 20, the bottom surface portion 22 is a shape that is perpendicular to the direction in which the stirrer 15 is moved and is curved downward in the vertical direction in a cross-sectional view perpendicular to the vertical direction. Is preferable. By providing such a shape, the sediment is easily collected in the curved portion, and the stirring efficiency is improved. It is also preferable that the shape of a part of the stirring bar 15 and the shape of the bottom surface portion 22 are formed in the same shape. For example, if the shape of the bottom surface portion 22 is formed in a shape curved downward in the vertical direction, the shape of the stirrer 15 may be a spherical shape or an ellipsoidal shape. Thereby, the contact surface of the stirring element 15 and the bottom face part 22 increases, and the stirring efficiency of the settled sediment improves.

  The shape of the connecting portion between the side surface portion 26 and the bottom surface portion 22 is preferably formed in the same shape as a part of the shape of the stirring bar 15. For example, if the shape of the connecting portion is a curved shape, the shape of the stirrer 15 may be a spherical shape or an ellipsoidal shape. As a result, the stirrer 15 easily comes into contact with the connecting portion, and the stirring efficiency of the sediment that has settled near the connecting portion increases.

  Moreover, it is preferable that the shape of the connection portion between the side surface portion 26 and the bottom surface portion 22 is a shape that is curved toward the outside of the container. Thereby, the clearance gap of a connection part becomes small, it can reduce that a sediment accumulates in a clearance gap, and stirring efficiency rises.

  Specifically, as shown in FIG. 2A, the stirrer 15 has a spherical shape, and the bottom surface portion 22 of the container 20 is in a direction orthogonal to the direction in which the stirrer 15 is moved. In the cross-sectional view perpendicular to the vertical direction, when the curve is curved downward in the vertical direction, sediment is likely to collect at the curved portion of the bottom surface portion 22, and the contact surface between the stirrer 15 and the bottom surface portion 22 is Increasing the amount of sediment that has settled down improves the stirring efficiency.

  Further, in the container 220 of FIG. 2C, the first side surface part 226a and the second side surface part 226b are curved toward the outside of the container 220, the stirrer 15 is spherical, the surface part, The bottom surface portion, the third side surface portion, and the fourth side surface portion are integrated to have a cylindrical portion 222. Since the container 220 includes the cylindrical portion 222, the sediment is easily collected at the curved portion, and the contact surface between the stirrer 15 and the cylindrical portion 222 is increased, and the stirring efficiency of the sedimented sediment is improved. Further, in the connecting portion 227 between the cylindrical portion 222 and the first side surface portion 226a and the second side surface portion 226b, the contact surface with the stirrer 15 is increased, and the amount of sediment deposited in the gap is also reduced, so that the stirring efficiency is improved. To rise.

  In FIG. 2C, both the first side surface portion 226a and the second side surface portion 226b are curved toward the outside of the container 220. However, both are necessarily curved toward the outside. It is not necessary to form the shape to be performed, and even if only one of them is used, an effect close to the above effect can be obtained.

1.4. In this embodiment, as described above, stirring is performed using the stirrer 15 based on the reciprocating motion of the carriage 50A, but the stirring unit is not particularly limited thereto. For example, it may be mounted on a carriage provided with an XY movement mechanism (moving on the XY plane) as described in JP-A-2002-225255. Further, as shown in FIG. 4, in the line-type ejection head 34, the container 20 may be near the line-type ejection head 34. In this case, as shown in FIG. 5A, the container 20 may be attached to the vibration device 35 and the stirring bar 15 may be moved to perform stirring.

  Further, the stirrer 15 may be moved by using a tilting device 36 that alternately tilts the container 20 as shown in FIG. In addition, the magnetic metal stirring bar 15 may be moved by moving the magnet 37 from the outside of the container 20 as shown in FIG.

  The stirring means in the present embodiment is not limited to the stirring means that moves the stirring bar in one direction to stir. For example, as shown in FIG. 6, the container 20 is attached to a movable device 39 operating in the XY plane, and the stirrer 15 in the container 20 is moved through the movable device 39 in the container 20 to perform stirring. Also good. In addition, the liquid stirring apparatus can employ known stirring means for moving the stirring bar 15.

1.5. Relationship between container, stirrer, and sediment The liquid stirrer in this embodiment has the following relationship between the vertical height (Ht) of the container and the vertical height (Hb) of the stirrer: Equation (1) is satisfied.
0.40 × Ht ≦ Hb ≦ 0.90 × Ht (1)

  Here, the height (Ht) in the vertical direction inside the container 20 is a sectional view in a predetermined direction (longitudinal direction) passing through a point where the height in the vertical direction is maximum in the container 20, and the minimum in the vertical direction. Means the height of Further, the height (Hb) of the stirrer in the vertical direction refers to the maximum height of the stirrer 15 in the vertical direction.

  FIG. 7A is an explanatory diagram showing a state where all of the components that can settle in the liquid, including Ht and Hb, are settled when the liquid is supplied into the container 20.

  As described above, in the container 20 provided in the liquid stirring apparatus 100 according to the present embodiment, the relationship between Ht and Hb satisfies the above formula (1). Thereby, the stirring bar 15 can move easily in the container 20, and the sediment HI and the liquid in the container 20 can be sufficiently stirred. In particular, when the sediment HI is not solidified at the bottom surface portion 22 of the container 20 and the stirrer 15 can move while contacting the bottom surface portion 22 of the container 20, the above formula (1) is satisfied. Thus, the stirring bar 15 can effectively stir the sediment HI and the liquid in the container 20.

  On the other hand, if Hb is less than 40% of Ht, Hb becomes too small with respect to Ht, so that the stirring efficiency of the liquid is lowered and the precipitate HI and the liquid may not be sufficiently stirred. . On the other hand, when Hb exceeds 90% of Ht, the stirrer 15 is likely to be subjected to the resistance of the liquid, and the sediment HI and the liquid may not be sufficiently stirred.

Furthermore, the container 20 included in the liquid stirring apparatus 100 according to the present embodiment satisfies the above formula (1), and the height (Hi) of the sediment HI that can be generated in the container 20 in the vertical direction, Ht, and Hb It is preferable that the relationship satisfies the following formulas (2-1) and (2-2).
Hi ÷ Ht ≦ 0.26 (2-1)
2.50 × Hi ≦ Hb ≦ 0.90 × (Ht−Hi) (2-2)

  The height (Hi) in the vertical direction of the sediment HI means that the liquid containing the component having the same predetermined concentration as that of the liquid storage unit 10 is allowed to settle on the bottom surface part 22 in the container 20, and the height in the container The maximum height of the sediment HI when the upper surface of the sediment HI is horizontal.

  As for the container 20 with which the liquid stirring apparatus 100 which concerns on this embodiment is shown to Formula (2-1), it is preferable that Hb is [0.90x (Ht-Hi)] or less. Thereby, even if the stirrer 15 rides on the sediment HI when the sediment HI is solidified, the movement of the stirrer 15 is hardly hindered and can easily move in the container 20. And the liquid can be sufficiently stirred. Note that “solidification” refers to a state where the stirrer 15 does not contact the bottom surface portion 22 of the container 20 when the stirrer 15 moves on the sediment HI. A specific positional relationship is shown in FIG.

  On the other hand, when Hb exceeds [0.90 × (Ht−Hi)], the stirrer 15 is easily subjected to liquid resistance, or the stirrer 15 is clogged in the container 20 and cannot move. In some cases, it becomes difficult to stir the liquid and the sediment HI.

  The container 20 provided in the liquid stirring apparatus 100 according to the present embodiment satisfies the formula (2-1). If Expression (2-1) is not satisfied, a relation satisfying Expression (2-2) cannot be obtained.

  In Formula (2-2), it is preferable to set Hb to be 2.50 times or more of Hi. In particular, when the sediment HI is solidified, if Hb is 2.50 times or more of Hi, even if a part of the stirrer 15 is filled with the sediment HI, the stirrer 15 is moved by the operation of the carriage 50A. The container 20 can be moved.

  On the other hand, if Hb is less than 2.50 times Hi, the stirrer 15 may be buried in the sediment HI and cannot move.

2. Droplet Discharge Device A droplet discharge device according to the present invention includes the liquid stirring device 100 described above. In the present embodiment, the droplet discharge device 300 having the liquid stirring device 100 will be described using an ink jet printer.

  FIG. 8 is a perspective view schematically showing a droplet discharge device 300 including the liquid stirring device 100. As illustrated in FIG. 8, the droplet discharge device 300 according to the present embodiment includes a control unit 360, a liquid storage unit 10, a liquid supply pipe 30, a drive unit 50, and a transport unit 70.

  The drive unit 50 can include a carriage 50A, a drive belt 50B, and a carriage motor 50C. The drive unit 50 is electrically connected to the control unit via the flexible cable 62 and is controlled by the control unit. The drive unit 50 has a function of reciprocating the carriage 50A on which the ejection head 33 is mounted. Specifically, the drive belt 50B connected to the carriage 50A is driven by the power of the carriage motor 50C serving as a drive source of the carriage 50A, and the carriage 50A is reciprocated.

  The ejection head 33 can have a plurality of nozzles that eject droplets. Further, the method for discharging droplets of the discharge head 33 is not particularly limited, and for example, an inkjet discharge method can be used. As the ink jet ejection method, any conventionally known method can be used, and examples thereof include a piezoelectric ink jet and a thermal ink jet.

  The medium to be ejected is conveyed by the conveyance unit 70, and the liquid from the liquid storage unit 10 is ejected by the ejection head 33 mounted on the carriage 50A in the course of conveyance. Then, it is discharged out of the apparatus by a discharge unit (not shown).

  In addition to the exemplified image recording apparatus such as an ink jet printer, the droplet discharge apparatus 300 of the present invention includes a color material ejecting apparatus, an organic EL display, an FED (surface emitting display) used for manufacturing a color filter such as a liquid crystal display, It is also suitably used as a liquid material ejecting apparatus used for forming an electrode such as an electrophoretic display or a color filter, and a bioorganic material ejecting apparatus used for biochip manufacture.

3. Examples Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples.

3.1. Preparation of white ink composition A white ink composition having the following composition was prepared.

(1) First white ink composition Titanium dioxide (average particle size 240 nm): 10% by mass
Styrene-acrylic acid copolymer: 2% by mass
1,2-hexanediol: 5% by mass
Glycerin: 10% by mass
Triethanolamine: 0.9% by mass
BYK-348 (Bic Chemie Japan Co., Ltd.): 0.5% by mass
Ultrapure water: remaining 100% by mass

(2) Second White Ink Composition Titanium dioxide in the first white ink composition described above is 20% by mass, and the other composition is the same as that of the first white ink composition.

(3) Third White Ink Composition Titanium dioxide in the first white ink composition described above is 23% by mass, and the other composition is the same as that of the first white ink composition.

3.2. Preparation of test samples 3.2.1. Preparation of Sample for First Evaluation Test A stirrer is arranged inside, and a cylindrical container having a diameter (Ht) of 15 mm and a height of 65 mm is used, and the above “3.1. (1)” is used inside the container. The first white ink composition prepared in (1) was filled and sealed. Subsequently, the component which can be settled and the liquid which are contained in the 1st white ink composition in a container were isolate | separated using the centrifuge (desktop multi-centrifuge LC-131, the product made by Tommy Industry Co., Ltd.). Centrifugation was performed for 2 hours under the conditions of a rotation radius of 21 cm and a centrifugal acceleration of 600 rpm. Moreover, after centrifugation, the sediment was not solidified, and the stirring bar was in contact with the bottom surface of the container. The stirrer was a spherical stainless steel (specific gravity 7.9), and the diameter (Hb) was 95% (14.3 mm) with respect to the diameter (Ht) of the container.

Thereafter, the container was attached to the carriage of an ink jet printer (product name “EPSON PX-G930”, manufactured by Seiko Epson Corporation) so that the longitudinal direction of the container was parallel to the moving direction (horizontal direction) of the carriage. The container was hermetically sealed so that the ink composition was not supplied into the container and the ink composition was not supplied from the container to the head.
Next, the carriage was reciprocated 100 times at a distance of 23 cm at a speed of 46 cm / second to stir the first white ink composition in the container. Thereafter, 1 g of the liquid in the container was taken out to obtain a sample (1-1) for the first evaluation test.

Sample (1-2) for the first evaluation test is the same as “Sample (1-1)” except that a 90% (13.5 mm) stirrer is used with respect to the diameter (Ht) of the container. It is.
Sample (1-3) for the first evaluation test is the same as “Sample (1-1)” except that a 70% (10.5 mm) stirrer is used with respect to the diameter (Ht) of the container. It is.
Sample (1-4) for the first evaluation test is the same as “Sample (1-1)” except that a 50% (7.5 mm) stirrer is used with respect to the diameter (Ht) of the container. It is.
Sample (1-5) for the first evaluation test was the same as “Sample (1-1)” except that a 40% (6.0 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (1-6) for the first evaluation test is the same as “Sample (1-1)” except that a 30% (4.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (1-7) for the first evaluation test is the same as “Sample (1-1)” except that the stirrer was not used.

  The same procedure as in “Sample (1-1)” was performed except that the second white ink composition obtained in “3.1. (2)” was used. In this way, a sample (1-8) for the first evaluation test was obtained. After centrifugation, the sediment was not solidified, and the stirring bar was in contact with the bottom surface of the container.

  The above “Sample (1-1)” except that a cylindrical container having a diameter (Ht) of 25 mm and a height of 75 mm was used and a stirrer of 95% (23.8 mm) with respect to the diameter (Ht) of the container was used. ". In this way, a sample (1-9) for the first evaluation test was obtained.

Sample (1-10) for the first evaluation test was the same as “Sample (1-9)” except that a 90% (22.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (1-11) for the first evaluation test was the same as “Sample (1-9)” except that a 40% (10.0 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (1-12) for the first evaluation test was the same as “Sample (1-9)” except that a 30% (7.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.

  Sample (1-13) for the first evaluation test is a 15 mm long × 15 mm wide × 65 mm high rectangular container attached so that the height direction of the container is parallel to the carriage moving direction. The same as “Sample (1-1)”, except that a 90% (13.5 mm) spherical stirrer is used for (Ht).

Sample (1-14) for the first evaluation test was the same as “Sample (1-13)” except that a 40% (6.0 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
The sample (1-15) for the first evaluation test was the above-mentioned “sample (1-13)” except that a 40% (6.0 mm) cubic stirrer was used with respect to the diameter (Ht) of the container. It is the same.

3.2.2. Preparation of Sample for Second Evaluation Test A stirrer is arranged inside, and a cylindrical container having a diameter (Ht) of 15 mm and a height of 65 mm is used, and the above “3.1. (1)” is used inside the container. The first white ink composition prepared in (1) was filled and sealed. Next, using a centrifuge, components that could settle and liquid contained in the first white ink composition in the container were separated. Centrifugation was performed for 2 hours under the conditions of a rotation radius of 21 cm and a centrifugal acceleration of 600 rpm. After centrifugation, the container was left at 20 ° C. for 1 month. The sediment in the container after being left for one month was solidified. The stirrer 15 is a spherical stainless steel (specific gravity 7.9), and has a diameter (Hb) of 95% (14.3 mm) with respect to the diameter (Ht) of the container.

  Moreover, the volume of the component (titanium dioxide) which can be precipitated in the first white ink composition in the container is 8% with respect to the volume of the container. In addition, the component (titanium dioxide) that can be precipitated in the first white ink composition in the container has a height (Hi) in the vertical direction of the precipitate of 2.06 mm (13. Diameter of the container (Ht)). 3%).

  After the container is left for one month, it is attached to the carriage of an inkjet printer (product name “EPSON PX-G930”, manufactured by Seiko Epson Corporation) so that the longitudinal direction of the container is parallel to the moving direction (horizontal direction) of the carriage. It was. The container was hermetically sealed so that the ink composition was not supplied into the container and the ink composition was not supplied from the container to the head.

  Next, the carriage was reciprocated 100 times at a distance of 23 cm at a speed of 46 cm / second to stir the first white ink composition in the container. Thereafter, 1 g of the liquid in the container was taken out to obtain a sample (2-1) for the second evaluation test.

Sample (2-2) for the second evaluation test was the same as “Sample (2-1)” except that a 90% (13.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-3) for the second evaluation test was the same as “Sample (2-1)” except that an 80% (12.0 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-4) for the second evaluation test was the same as “Sample (2-1)” except that a 75% (11.3 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-5) for the second evaluation test is the same as “Sample (2-1)” except that a 70% (10.5 mm) stirrer is used with respect to the diameter (Ht) of the container. It is.
Sample (2-6) for the second evaluation test is the same as “Sample (2-1)” except that a 60% (9.0 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-7) for the second evaluation test is the same as “Sample (2-1)” except that a 50% (7.5 mm) stirrer is used with respect to the diameter (Ht) of the container. It is.
Sample (2-8) for the second evaluation test was the same as “Sample (2-1)” except that a 40% (6.0 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-9) for the second evaluation test is the same as “Sample (2-1)” except that a 30% (4.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-10) for the second evaluation test is the same as “Sample (2-1)” except that the stirrer was not used.

  The sample (2-11) for the second evaluation test uses the second white ink composition obtained in the above “3.1. (2)” and is 95% (14) with respect to the diameter (Ht) of the container. .3 mm), except that a spherical stirrer is used. In addition, the volume of the component (titanium dioxide) that can be precipitated contained in the second white ink composition in the container is 16% with respect to the volume of the container. Further, the component (titanium dioxide) that can be precipitated contained in the first white ink composition in the container has a height (Hi) in the vertical direction of the precipitate of 3.30 mm (21. 3%).

Sample (2-12) for the second evaluation test is the same as “Sample (2-11)” except that a 90% (13.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-13) for the second evaluation test was the same as “Sample (2-11)” except that a 75% (11.3 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-14) for the second evaluation test was the same as “Sample (2-11)” except that a 70% (10.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-15) for the second evaluation test is the same as “Sample (2-11)” except that a stirrer 55% (8.3 mm) is used with respect to the diameter (Ht) of the container. It is.
Sample (2-16) for the second evaluation test is the same as “Sample (2-11)” except that a 50% (7.5 mm) stirrer was used for the diameter (Ht) of the container. It is.
Sample (2-17) for the second evaluation test was the same as “Sample (2-11)” except that a 40% (6.0 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-18) for the second evaluation test was the same as “Sample (2-11)” except that a 30% (4.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-19) for the second evaluation test is the same as “Sample (2-11)” except that the stirrer was not used.

  The sample (2-20) for the second evaluation test uses the third white ink composition obtained in the above “3.1. (3)” and is 95% (14) with respect to the diameter (Ht) of the container. .3 mm), except that a spherical stirrer is used. In addition, the volume of the component (titanium dioxide) that can be precipitated contained in the third white ink composition in the container is 18.5% with respect to the volume of the container. Moreover, the height (Hi) in the vertical direction of the sediment when all components (titanium dioxide) contained in the first white ink composition in the container are settled in the container is 3.72 mm ( 24.0% of the diameter (Ht) of the container).

Sample (2-21) for the second evaluation test was the same as “Sample (2-20)” except that a 90% (13.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-22) for the second evaluation test is the same as “Sample (2-20)” except that a 70% (10.5 mm) stirrer is used with respect to the diameter (Ht) of the container. It is.
Sample (2-23) for the second evaluation test is the same as “Sample (2-20)” except that a stirrer of 65% (9.8 mm) is used with respect to the diameter (Ht) of the container. It is.
Sample (2-24) for the second evaluation test was the same as “Sample (2-20)” except that a 60% (9.0 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-25) for the second evaluation test is the same as “Sample (2-20)” except that a 50% (7.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-26) for the second evaluation test is the same as “Sample (2-20)” except that a 30% (4.5 mm) stirrer was used with respect to the diameter (Ht) of the container. It is.
Sample (2-27) for the second evaluation test is the same as “Sample (2-20)” except that the stirrer was not used.

3.3. Evaluation test 3.3.1. First Evaluation Test Distilled water was added to 1 g of the samples (1-1) to (1-15) obtained as described above and diluted 1000 times. Subsequently, the absorbance (Abs value) at a wavelength of 500 nm of the diluted white ink composition was measured using a spectrophotometer (product name “Spectrophotometer U-3300”, manufactured by Hitachi, Ltd.). The absorbance of each sample thus obtained was compared with the absorbance of the white ink composition before the centrifugation operation, and the absorbance recovery rate was determined using the following formula (3).

      Absorbance recovery rate (%) = 100 × (absorbance of sample) / (absorbance before centrifugation) (3)

  In addition, it shows that the stirring efficiency of an ink composition is excellent, so that the recovery rate of a light absorbency is high. The classification of evaluation criteria in the first evaluation test is as follows.

◎: Absorbance recovery rate is 80% or more ○: Absorbance recovery rate is 70% or more and less than 80% ×: Absorbance recovery rate is less than 70%

3.3.2. Second Evaluation Test Samples (2-1) to (2-27) obtained as described above were subjected to an absorbance recovery rate in the same manner as in “3.3.1. First Evaluation Test”. It was. The classification of evaluation criteria in the second evaluation test is as follows.

◎: Absorbance recovery rate is 80% or more ○: Absorbance recovery rate is 70% or more and less than 80% ×: Absorbance recovery rate is less than 70%

3.4. Evaluation results Table 1 shows the results of the first evaluation test. Tables 2 and 3 show the results of the second evaluation test.

3.4.1. About Formula (1) In the first evaluation test, from Table 1, samples (1-2) to (1-5), (1-8), (1-10) to (1-11), (1-13) It was confirmed that when the containers and the stirrer of (1-15) were used, a liquid stirrer excellent in absorbance recovery and excellent in stirring efficiency was obtained. On the other hand, when the containers and stirrers of samples (1-1), (1-6), (1-7), (1-9), and (1-12) are used, none of them has an excellent absorbance recovery rate. Thus, it was confirmed that a liquid stirring device having excellent stirring efficiency was obtained.

  From Table 2 of the 2nd evaluation test result, the container and stirring of sample (2-2)-(2-8), (2-12)-(2-17), (2-21)-(2-25) It was confirmed that a liquid stirring device having an excellent absorbance recovery rate and excellent stirring efficiency can be obtained by using a kid. On the other hand, the containers and stirrers of Samples (2-1), (2-9) to (2-11), (2-18) to (2-20), (2-26), and (2-27) were used. When it was used, it was confirmed that a liquid agitation apparatus that was not excellent in absorbance recovery rate and agitated efficiency was obtained.

From the above, it can be seen that high stirring efficiency can be obtained by satisfying the formula (1).
0.40 × Ht ≦ Hb ≦ 0.90 × Ht (1)

3.4.2. About Formula (2-1), (2-2) From Table 3 of the second evaluation test result, samples (2-4) to (2-8), (2-14), (2-15), (2 It has been shown that when the containers and the stirrer of -23) and (2-24) are used, even if the precipitate is solidified, a higher stirring efficiency can be obtained. On the other hand, samples (2-1) to (2-3), (2-9) to (2-13), (2-16) to (2-22), (2-25) to (2-27) It was shown that when a container and a stirrer were used, the movement of the stirrer was remarkably hindered by the sediment, and a liquid stirrer with poor stirring efficiency was obtained.

  From the above, it can be seen that higher stirring efficiency can be obtained by satisfying the formulas (2-1) and (2-2).

  DESCRIPTION OF SYMBOLS 10 ... Liquid accommodating part, 15 ... Stirrer, 18 ... Middle part, 20, 120, 220 ... Container, 22 ... Bottom part, 24 ... Top part, 26a, 226a ... 1st side part, 26b, 226b ... 2nd Side surface portion, 227 ... connection portion, 26c ... third side surface portion, 26d ... fourth side surface portion, 30a, 30b ... liquid supply pipe, 33 ... discharge head, 34 ... line-type discharge head, 35 ... vibration device, 36 ... Tilt device, 37 ... magnet, 39 ... movable device, 50 ... drive unit, 50A ... carriage, 50B ... drive belt, 50C ... carriage motor, 62 ... flexible cable, 70 ... paper feed unit, 72 ... paper feed roller, 100 ... Liquid stirrer, 122, 222 ... cylindrical portion, 300 ... droplet discharge device.

Claims (4)

A liquid container containing a liquid containing a component that can settle;
A container into which the liquid flows from the liquid container;
A stir bar that is housed inside the container and stirs the liquid;
The container is a liquid supply apparatus comprising a bottom surface portion that constitutes the inside of the container and the stirrer moves to,
The relationship between the height (Ht) in the vertical direction of the middle region inside the container and the height (Hb) in the vertical direction of the stirrer satisfies the following formula (1) :
The component of the liquid stored in the liquid storage unit has a predetermined concentration;
The relationship between the height (Hi) in the vertical direction of the sediment of the component contained in the liquid in the container, the Ht, and the Hb is expressed by the following formulas (2-1) and (2-2). ), Satisfying,
A liquid stirring apparatus characterized by the above.
0.40 × Ht ≦ Hb ≦ 0.90 × Ht (1)
Hi ÷ Ht ≦ 0.26 (2-1)
2.50 × Hi ≦ Hb ≦ 0.90 × (Ht−Hi) (2-2)   The liquid stirring apparatus according to claim 1, wherein the component that can settle is one type selected from the group consisting of an inorganic pigment, a metal pigment, and hollow resin particles.   The bottom surface portion is formed in a direction that is perpendicular to the direction in which the stirrer is moved and is perpendicular to the vertical direction, and has a shape that curves downward in the vertical direction. The liquid stirring apparatus according to claim 1 or 2. The container has a side surface provided in a direction in which the stirrer is moved,
The liquid stirring apparatus according to any one of claims 1 to 3, wherein a connecting portion between the side surface portion and the bottom surface portion is curved toward the outside of the container.

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