JP2012000826A - Liquid supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid supply device excellent in liquid agitating efficiency.SOLUTION: The liquid supply device includes: a storage part for storing a liquid composition containing a pigment; a head for ejecting the liquid composition; a container connected to the storage part and the head through a supply passage for supplying the liquid composition, supplied with the liquid composition from the storage part to supply the liquid composition to the head, and having an agitator inside; and a carriage with the container mounted thereon. The carriage reciprocates in a predetermined direction. The agitator moves within the container based on the reciprocating operation of the carriage. The specific gravity of the agitator is at least 0.8 times that of the pigment.

Description

  The present invention relates to a liquid supply apparatus.

  2. Description of the Related Art Conventionally, an ink supply system that supplies ink to a head that can eject ink from an ink tank that stores 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 from the viewpoint of a difference in specific gravity from the solvent.

  For example, Patent Document 1 describes an ink supply system provided with a sub tank that always holds a certain 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.

  Japanese Patent Application Laid-Open No. H10-228561 describes that the ink tank in which the steel ball is sealed is manually stirred to stir the ink in the ink tank. In addition, a stirring member with a permanent magnet attached is enclosed in the ink tank, and the stirring member is rotated by a rotor having an electromagnet provided outside the ink tank to stir the ink in the ink tank. Are listed.

JP 2006-272648 A JP 2005-212336 A

  However, in the above-described prior art, depending on the type of ink used and the material of the stirrer, the precipitate generated at the bottom of the sub tank cannot be sufficiently stirred, and the stirring ability may be insufficient. In addition, it may be difficult to stir the sediment generated at the bottom of the sub tank by a simple stirring mechanism.

  One of the objects according to some aspects of the present invention is to provide a liquid supply apparatus having excellent stirring efficiency by solving the above-described problems.

  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 supply apparatus according to the present invention is as follows.
A container for containing a liquid composition containing a pigment;
A head for discharging the liquid composition;
The liquid composition is connected to the storage section and the head via a supply path for supplying the liquid composition, and the liquid composition is supplied from the storage section to supply the liquid composition to the head, and has a stir bar inside. A container,
A carriage on which the container is mounted;
Have
The carriage can reciprocate in a predetermined direction,
The stirrer moves in the container based on the reciprocating motion of the carriage,
The stirring bar has a specific gravity of 0.8 times or more that of the pigment.

  According to the invention described in Application Example 1, since the specific gravity of the stirrer is 0.8 times or more the specific gravity of the pigment contained in the liquid composition, the sediment containing the pigment settled at the bottom of the container is scraped while being pushed apart. Can be mixed and the sediment in the container can be redispersed in the liquid composition. Thereby, the liquid supply apparatus excellent in stirring efficiency can be obtained.

[Application Example 2]
In application example 1,
The stirring bar may have a specific gravity of 3.6 or more.

  According to the invention described in Application Example 2, the action of stirring the precipitate while pushing it further increases, and the liquid composition in the container can be sufficiently stirred.

[Application Example 3]
In application example 1 or application example 2,
The shape of the stirring bar may be a sphere or an ellipsoid.

  According to the invention described in Application Example 3, the stirrer can easily move in the container, and the stirring efficiency of the liquid composition can be improved.

[Application Example 4]
In any one of Application Examples 1 to 3,
The specific gravity of the stirrer may be not more than twice the specific gravity of the pigment.

[Application Example 5]
In any one of Application Examples 1 to 4,
The stirring bar may have a specific gravity of 10 or less.

[Application Example 6]
In any one of Application Examples 1 to 5,
The head can be mounted on the carriage.

[Application Example 7]
In Application Example 6,
The carriage can perform a first operation for performing the reciprocating operation without an operation for discharging the liquid composition from the head,
In the first operation, the carriage can be reciprocated 10 times or more.

[Application Example 8]
In Application Example 6 or Application Example 7,
The carriage performs a first operation for performing the reciprocating operation without an operation for ejecting the liquid composition from the head, and a second operation for performing the reciprocating operation with an operation for ejecting the liquid composition from the head. And is possible,
The first operation is performed at least when a predetermined time has elapsed since the carriage stopped.
According to the invention described in Application Example 8, since the first operation is performed after the sediment is sufficiently accumulated at the bottom of the container, the number of executions of the first operation can be reduced and the variation in the component composition ratio can be reduced. A reduced liquid composition can be supplied to the head.

The side view which shows typically the liquid supply apparatus which concerns on this embodiment. The perspective view which shows typically the container in the liquid supply apparatus which concerns on this embodiment. The perspective view which shows typically the droplet discharge apparatus which concerns on this embodiment. The figure which shows the light absorbency recovery rate for every frequency | count of stirring.

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

1. Liquid supply apparatus The liquid supply apparatus according to the present invention includes a storage unit that stores a liquid composition containing a pigment,
A head that discharges the liquid composition and a supply path that supplies the liquid composition are connected to the storage unit and the head, and the liquid composition is supplied from the storage unit to the liquid composition. And a carriage on which the container is mounted, the carriage is capable of reciprocating in a predetermined direction, and the stirrer is capable of reciprocating the carriage. It moves in the container based on the operation, and the specific gravity of the stirrer is not less than 0.8 times the specific gravity of the pigment.

  FIG. 1 is a side view schematically showing a liquid supply apparatus 100 according to the present embodiment. FIG. 2 is a perspective view schematically showing the container 20 in the liquid supply apparatus 100 according to this embodiment. Hereinafter, the liquid supply apparatus 100 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  As illustrated in FIG. 1, the liquid supply apparatus 100 according to the present embodiment includes a storage unit 10, a container 20, a tube 30, a head 40, and a carriage 50A. In the example of FIG. 1, the container 20 and the head 40 are mounted on a carriage 50A. The container 20 includes a stirring bar 15 therein. The carriage 50A can reciprocate in a predetermined direction MSD.

1.1. Housing Part The liquid supply apparatus in the present embodiment has a housing part. The storage unit stores a liquid composition to be described later. In the example of FIG. 1, the accommodating portion 10 is connected to the container 20 via a tube 30a. Thereby, the liquid composition can be supplied to the container 20.

  The container 10 is preferably configured to replenish the consumed liquid composition, and more preferably configured to replenish the liquid composition during operation of the liquid supply apparatus 100. By replenishing the container 10 with the liquid composition without stopping the operation of the liquid supply apparatus 100, the working efficiency can be improved.

  The liquid composition contains a pigment. For example, examples of the liquid composition stored in the storage unit 10 include ink compositions, materials for color filters used in organic EL displays, liquid crystal displays, FEDs (surface emitting displays), and electrophoretic displays. It is done.

  Examples of the pigment include organic pigments and pigments made of metals or metal oxides. The organic pigment is not particularly limited as long as it satisfies the relationship with the specific gravity of the stirrer described later. For example, azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic Examples thereof include pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinofullerone pigments), nitro pigments, nitroso pigments, and aniline black.

  Further, the metal or metal oxide is not particularly limited as long as it satisfies the relationship with the specific gravity of the stir bar described later. For example, examples of the metal include aluminum, gold, silver, copper, zinc, titanium, and alloys thereof. From the viewpoint of excellent metal gloss, aluminum or silver is preferably used. Examples of the metal oxide include titanium dioxide, aluminum oxide, zinc oxide, and iron oxide. In the liquid composition used in the liquid supply apparatus according to this embodiment, a metal or a metal oxide functions as a pigment.

  The liquid composition further includes a solvent such as an organic solvent and water, and a composition having a specific gravity difference between the precipitation component (for example, the above-described pigment) and the solvent of 1 or more. Thus, even if the specific gravity difference between the solvent in the liquid and the sediment component is large, the liquid supply device 100 according to the present invention can be used to sufficiently stir and supply a liquid with little variation in the component composition ratio. can do.

  Hereinafter, a white ink composition typically used as a liquid composition stored in the storage unit 10 will be described. For example, in the white ink composition, the above-described titanium dioxide can be used as a white pigment. The content of titanium dioxide is preferably 5% by mass or more and 20% by mass or less, more preferably 8% by mass or more and 15% by mass or less with respect to the total mass of the white ink composition. If the content of titanium dioxide exceeds the above range, clogging of the head 40 may occur. Moreover, when the content of titanium dioxide is less than the above range, whiteness may be insufficient.

  The white ink composition can include a resin for fixing the pigment. Examples of the resin include an acrylic resin (for example, Almatex (manufactured by Mitsui Chemicals)), a urethane resin (for example, WBR-022U (manufactured by Taisei Fine Chemical)), and the like. The content of the resin is preferably 0.5% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 3% by mass or less with respect to the total mass of the white ink composition.

  The white ink composition preferably contains at least one selected from alkanediols and glycol ethers. Alkanediols and glycol ethers can enhance the wettability of a recording surface such as a recording medium and improve 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 recording media.

  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 content of at least one selected from these alkanediols and glycol ethers is preferably 1% by mass or more and 20% by mass or less, more preferably 1% by mass or more, based on the total mass of the white ink composition. It is 10 mass% or less.

  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 recording medium 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. Moreover, a commercial item can also be utilized for acetylene glycol type-surfactant, for example, Orphine E1010, STG, Y (above, Nissin Chemical Co., Ltd.), Surfinol 104, 82, 465, 485, TG (above , 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 Big Chemie Japan Co., Ltd.) and the like.

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

  The content of the surfactant is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 0.5% by mass or less, with respect to the total mass of the white ink composition. It is.

  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 ink drying and prevent clogging of the ink in the ink jet recording 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 content of the polyhydric alcohol is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 0.5% by mass or more and 20% by mass or less, with respect to the total mass of the white ink composition. .

  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 is described as an example of the white ink composition, a radiation curable ink composition or the like may be used.

1.2. Pipe The liquid supply apparatus in this embodiment has a pipe | tube which supplies a liquid composition. In the example of FIG. 1, the pipe 30 includes a liquid supply pipe 30 a and a liquid supply pipe 30 b. In FIG. 1, the liquid supply pipe 30 a connects the storage unit 10 and the container 20. In FIG. 1, the liquid supply pipe 30 b connects the container 20 and the head 40. The liquid composition stored in the storage unit 10 is supplied to the container 20 through the liquid supply pipe 30a, and after being stirred by the stirrer 15 in the container 20, flows in the container 20 and flows into the liquid supply pipe. It is supplied to the head 40 via 30b.

  Although it does not specifically limit as a shape of the pipe | tube 30, The following can be mentioned. For example, a straight line connecting the accommodating part 10 and the head 40 with a simple straight line, a slack shape, a wave shape including a part where a locally high part and a low part are alternately repeated, and a part where a plurality of loops are connected The loop shape etc. which contain can be mentioned.

  A partition (not shown) that is twisted along the flow direction of the liquid composition may be provided inside the tube 30. The partition has a function of stirring the liquid composition introduced into the tube 30. The liquid composition introduced into the tube 30 travels through the tube 30 along the partition portion having a twisted structure, and is supplied to the head 40. Thereby, the liquid composition in the pipe 30 can be sufficiently stirred.

  The material of the tube 30 is not particularly limited as long as it has flexibility, and examples thereof include an elastomer. Examples of the elastomer include vulcanized rubber such as natural rubber and synthetic rubber, and elastomers such as vinyl chloride, styrene, olefin, silicone, and fluorine.

  The inner diameter of the tube 30 is not particularly limited as long as the stirrer 15 does not move into the tube 30. For example, when the liquid supply device 100 is applied to a droplet discharge device 300 described later, the inner diameter of the tube 30 is preferably 2 mm or more and 5 mm or less, more preferably 2 mm or more and 4 mm or less.

1.3. Container and Stirrer The liquid supply apparatus according to the present embodiment is connected to a storage unit and a head via a tube, and includes a container that is supplied with a liquid composition from the storage unit and supplies the liquid composition to the head. Moreover, the container in the liquid supply apparatus of this embodiment has a stirring bar inside.

  Further, the container in the liquid supply apparatus according to the present embodiment is mounted on the carriage and can move based on the movement of the carriage. When the container is mounted on the carriage, it is not necessary to provide a separate mechanism for moving only the container, and the carriage moving mechanism can be used. Therefore, mounting the container on the carriage is excellent from the viewpoint that a liquid supply device having excellent stirring efficiency can be easily obtained.

  As shown in FIG. 1, the container 20 has a stirring bar 15 inside thereof. In FIG. 1, the container 20 is connected to the accommodating part 10 through the liquid supply pipe 30a. The connection part J1 of the container 20 and the liquid supply pipe 30a may be provided in any part of the container 20 as long as it is formed in a part other than J2 described later.

  In FIG. 1, the container 20 is connected to the head 40 via the liquid supply pipe 30b. Moreover, the connection part J2 of the container 20 and the liquid supply pipe 30b may be provided in any part of the container 20 as long as it is formed in parts other than J1.

  The direction, angle, and the like of the container 20 are not particularly limited as long as the stirring bar 15 moves based on the reciprocating motion of the carriage 50A.

  Examples of the shape of the container 20 of the liquid supply apparatus 100 according to the present embodiment include a rectangular parallelepiped shape, a cylindrical shape, and an elliptical cylindrical shape. In addition, in this specification, the shape of a container means the internal shape of a container.

  As shown in FIG. 2A, the container 20 includes an upper surface portion 24, a bottom surface portion 22, a first side surface portion 26 extending in a predetermined direction MSD, a second side surface portion 28 facing the predetermined direction MSD, It is preferable that the cross section perpendicular to the predetermined direction MSD of the bottom surface portion 22 includes a curved line whose outer peripheral portion is convex toward the outside of the container. Specifically, in the example of FIG. 2A, the bottom surface portion 22 has a downwardly convex curved surface in the vertical direction VD, is connected to the first side surface portion 26 and the second side surface portion 28, and , Has a continuous surface. The upper surface portion 24 is connected to the first side surface portion 26 and the second side surface portion 28 and has a continuous surface. The first side surface portion 26 includes two opposing surfaces extending along a predetermined direction MSD. The second side surface portion 28 is connected to the liquid supply pipes 30a and 30b. The second side surface portion 28 is composed of two surfaces provided facing the predetermined direction MSD.

  In FIG. 2A, since the bottom surface portion 22 of the container 20 is a convex curved surface, the pigment contained in the liquid composition described above tends to settle on the convex portion of the bottom surface portion 22. On the other hand, the stirrer 15 is likely to be located on the convex portion of the bottom surface portion 22 and is likely to move along the convex portion of the bottom surface portion 22. As described above, since a large amount of sediment remains in the trajectory along which the stirrer 15 moves, the sediment can be stirred more efficiently by the movement of the stirrer 15. Therefore, when the container has the shape of FIG. 2A, the liquid supply apparatus 100 having excellent stirring efficiency can be obtained.

  In addition to the container 20 in FIG. 2A, a container 120 as shown in FIG. 2B may be used. The container 120 of FIG. 2B includes a curved line in which the outer peripheral portion of the cross section perpendicular to the predetermined direction MSD of the first side surface portion 26 and the upper surface portion 24 in FIG. For example, the cross-sectional shape orthogonal to the predetermined direction MSD of the container 120 can be circular. Specifically, the container 120 includes a cylindrical portion 122 in which the upper surface portion 24, the bottom surface portion 22, and the first side surface portion 26 in FIG. 2A are integrated, and a second side surface portion 128. Liquid supply pipes 30 a and 30 b are connected to the side surface portion 128. The second side surface portion 128 includes two surfaces provided to face each other in a predetermined direction MSD.

  In the example of FIG. 2B, the container 120 has a cylindrical portion 122 and has a circular cross-sectional shape perpendicular to the predetermined direction MSD. The shape may be elliptical. Moreover, although the container 120 has the cylindrical part 122, it may replace with a cylindrical shape and may use an elliptical cylindrical shape.

  Since the container 120 in FIG. 2B has a cylindrical shape or an elliptical cylindrical shape, the pigment contained in the liquid composition supplied into the container 120 tends to settle at the center of the bottom of the container 120. On the other hand, the stirrer 15 is easily located at the center of the bottom of the container 120 and easily moves along the center of the bottom. Thus, since a large amount of sediment remains on the trajectory along which the stirrer 15 moves, the sediment can be stirred more efficiently by the movement of the stirrer 15.

  In the container 20 (120) in the present embodiment, the outer peripheral part of the cross section parallel to the predetermined direction MSD of the second side surface part 28 (128) further includes a convex curve toward the outside of the container 20. preferable. An example of such a container is the container 220 in FIG. The container 220 has the same shape as the container 120 in FIG. 2B except that the second side surface portion 228 has a curved surface shape that protrudes outward from the container 220. Specifically, the container 220 has a continuous surface in which the cylindrical portion 222 and the side surface (second side surface portion 228) are connected.

  As shown in FIG. 2A, the container 20 does not have a curved surface in which the second side surface portion 28 is convex toward the outside of the container 20. For this reason, the sediment that has settled at the connecting portion between the second side surface portion 28 and the bottom surface portion 22 is less likely to come into contact with the stirrer 15 when the stirrer 15 is a sphere or ellipsoid (described later). Efficiency may be reduced. In addition, as shown in FIG.

  On the other hand, when the second side surface portion 228 has a convex curved surface toward the outside of the container 220 as in the container 220 shown in FIG. 2C, the stirrer 15 is a sphere or an ellipsoid. In some cases (described later), the stirrer 15 easily comes into contact with the connection portion between the second side surface portion 228 and the cylindrical portion 222. Therefore, the sediment collected at the connection portion between the second side surface portion 228 and the cylindrical portion 222 can be effectively stirred by the stirring bar 15.

  When the shape of the container 20 is a rectangular parallelepiped shape, it is preferable that the container 20 is arranged so that the long side is parallel to the predetermined direction MSD. Thereby, since the movement area | region of the stirring element 15 in the container 20 spreads and it becomes possible to move the inside of the container 20 efficiently, the stirring efficiency of a liquid composition can be improved.

  When the shape of the container 20 is a cylindrical shape or an elliptical cylinder shape, the container 20 is installed so that the cross-sectional shape of the container 20 orthogonal to the predetermined direction MSD is a circle or an ellipse, and the longitudinal direction thereof is a predetermined direction. It is preferable to arrange them in parallel with the MSD. When the container 20 is installed so that the longitudinal direction of the container 20 and the predetermined direction MSD are parallel, the stirrer 15 is further easily moved along the convex portion at the bottom of the container 20. Thereby, the sediment collected on the convex part of the bottom can be more efficiently stirred by the movement of the stirring bar 15.

  A plurality of containers 20 may be provided. By providing a plurality of containers 20, the stirring efficiency of the liquid composition can be improved. Further, the container 20 may include a plurality of stirring bars 15 therein. Thereby, the stirring efficiency of the liquid composition supplied to the container 20 can be improved.

  The stirrer 15 can move inside the container 20 based on the reciprocating motion of the carriage 50 </ b> A to stir the liquid composition and sediment supplied to the container 20. The orbit and moving direction of the stirring bar 15 are determined by the reciprocating motion of the carriage 50A, the supply amount of the liquid composition to the container 20, the orientation and angle of the container 20 attached, the shape of the container, and the like.

  The shape of the stirrer 15 may be any shape that can move within the container 20, and examples thereof include a polyhedron, a sphere, an ellipsoid, a cylinder, and an elliptic cylinder. Among these, it is preferable that it is a sphere or an ellipsoid from a viewpoint that the movement efficiency is excellent irrespective of the shape of the container 20.

  In addition, when using the container in which the bottom part of a container has a curved surface toward the outer side like FIG. 2 (A)-FIG.2 (C), the stirrer 15 is a sphere, an ellipsoid, a cylindrical shape, or an elliptical column. It is preferable to use one having a curved surface portion such as a shape, and more preferably a sphere or an ellipsoid. In such a case, the convex part of the bottom of the container and the convex part of the stirrer 15 easily come into contact with each other, and the sediment accumulated on the bottom of the container 20 can be efficiently stirred.

  Moreover, when the cylindrical or elliptical column-shaped stirrer 15 is used when the container having the shape as shown in FIGS. 2A to 2C is used, the convex portion at the bottom of the container and the stirrer 15 are used. The area of the portion in contact with the convex portion (hereinafter also referred to as “contact area”) is larger than that in the case of using the spherical or ellipsoidal stirrer 15. Therefore, when the cylindrical or elliptical columnar stirrer 15 is used, the frictional resistance received from the container may increase and the movement efficiency may decrease.

  On the other hand, when the shape of the stirrer 15 is a sphere or an ellipsoid, the contact area can be reduced while the stirrer 15 is in contact with the convex portion of the bottom surface of the container. For this reason, when the spherical or ellipsoidal stirrer 15 is used, the frictional resistance received from the container can be reduced and the movement efficiency is excellent, so that a liquid supply apparatus having excellent stirring efficiency can be obtained.

  The specific gravity of the stirrer 15 is not less than 0.8 times the specific gravity of the pigment contained in the liquid composition, and preferably not less than 0.8 times and not more than 2 times. Thereby, the liquid supply apparatus excellent in stirring efficiency can be obtained. In particular, when the pigment contained in the liquid composition settles on the bottom surface of the container 20, the stirrer 15 has a specific gravity of 0.8 times or more the specific gravity of the pigment contained in the liquid composition. Full contact with sediment. Therefore, the stirrer 15 can stir and separate the sediment, and can redisperse the sediment in the container in the liquid composition.

  On the other hand, when the specific gravity of the stirrer 15 is less than 0.8 times the specific gravity of the pigment contained in the liquid composition, the action of pushing the precipitate that the stirrer 15 has is reduced, and the precipitate is liquid composition. It may be difficult to re-disperse in the material, and the stirring efficiency may decrease. Moreover, when the specific gravity of the stirring bar 15 exceeds twice the specific gravity of the pigment contained in the liquid composition, the stirring bar 15 may be difficult to move.

  Furthermore, the specific gravity of the stirring bar 15 is preferably 3.6 or more, and more preferably 3.6 or more and 10 or less. When the specific gravity of the stirrer 15 is 3.6 or more, the action of stirring the above-described sediment while pushing it further increases, and the liquid composition in the container can be sufficiently stirred. On the other hand, if the specific gravity of the stirrer is less than 3.6, the action of stirring while pushing up the sediment may be reduced. If the specific gravity of the stirrer exceeds 10, the stirrer may not easily move when the carriage 50A (container 20) moves.

  The material of the stirrer 15 may be any material that is 0.8 times or more the specific gravity of the pigment contained in the liquid composition, and examples thereof include metals and metal oxides. Examples of the metal used as the material of the stirrer 15 include a single metal such as aluminum, titanium, chromium, nickel, zinc, iron, copper, silver, zirconium, or an alloy containing any one of these metals. . Examples of the metal oxide used as the material for the stirrer 15 include aluminum oxide, zirconium oxide, zinc oxide, and iron oxide.

  Among these, the stirrer 15 has excellent chemical resistance and is mass-produced as a general-purpose part, so that it can be obtained at low cost stainless steel (alloy containing chromium and nickel, specific gravity 7.93) or aluminum oxide (specific gravity 3.9). ) Is preferably used.

  The stirrer 15 is preferably surface-treated with a fluorine compound. Thereby, the friction coefficient of the surface of the stirring bar can be reduced, and the movement of the stirring bar 15 in the container becomes easy. Examples of the fluorine compound include polytetrafluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride. As a method of surface-treating the stirrer 15 with a fluorine compound, a known technique can be used and is not particularly limited.

1.4. Head The liquid supply apparatus according to this embodiment has a head. In the example of FIG. 1, the head 40 is mounted on the carriage 50A and connected to the container 20 via the liquid supply pipe 30b. The head 40 can discharge the liquid composition supplied from the liquid supply pipe 30b.

  The liquid composition supplied to the head 40 has been sufficiently stirred in the container 20. Therefore, the head 40 can eject a liquid composition with little variation in the component composition ratio.

1.5. Control Unit The liquid supply apparatus 100 according to this embodiment may include a control unit (not shown). The control means can be configured by using a computer having a CPU and a memory, and has a function of controlling the accommodating portion 10, the carriage 50A, and the head 40. The control unit controls the supply amount and supply timing of the liquid composition from the storage unit 10 to the head 40, controls the number of reciprocating movements, the movement speed, the movement distance, and the like of the carriage 50A, and is discharged from the head. It is possible to control the discharge timing and discharge amount of the liquid composition.

  Further, the control means may be provided with a time measuring means, and the stop time of the liquid supply apparatus 100 and the like can be measured. The time measuring means is not particularly limited as long as it can measure time, and a timer or the like can be used.

1.6. Stirring operation As described above, the stirrer 15 can move inside the container 20 and stir the liquid composition based on the reciprocating motion of the carriage 50A in the predetermined direction MSD. Hereinafter, the stirring operation of the liquid supply apparatus 100 will be described.

  The carriage 50 </ b> A performs a first operation (hereinafter also referred to as “stirring-only operation”) that performs a reciprocating operation without an operation for discharging the liquid composition from the head 40, and an operation for discharging the liquid composition from the head 40. Accordingly, a second operation (hereinafter also referred to as “printing operation”) that performs a reciprocating operation is possible. The liquid composition in the container 20 can be stirred in any of the above operations. The stirring-only operation is preferably performed under the condition that the stirrer 15 is reciprocated once in the predetermined direction MSD in the container 20 every time the carriage 50A is reciprocated once in the predetermined direction MSD.

  The stirring-only operation is a carriage operation different from the printing operation, and is preferably performed at least when a predetermined time has elapsed since the carriage 50A stopped. Thereby, since the sediment in the container 20 can be sufficiently stirred, the liquid composition in which the variation in the component composition ratio is reduced can be supplied to the head 40.

  Further, since the stirring-only operation can be performed after the sediment is sufficiently accumulated at the bottom of the container 20, the number of executions of the stirring-only operation can be reduced. In particular, when there is little sediment in the container 20 or the like, the liquid composition in the container 20 can be sufficiently removed by agitation by the above printing operation or when the change in absorbance of the liquid composition is small without performing the stirring-only operation. When stirring can be performed, it is not necessary to perform a stirring-only operation, so printing can be performed quickly.

  The predetermined time can be determined from the time during which the pigment contained in the liquid composition settles over a certain amount. The predetermined time can be determined based on the measured time by measuring the settling time of the pigment in advance according to the type of pigment used. The predetermined time may be stored in advance in the control means.

  Specifically, from the start of the stirring-only operation of the carriage 50A to the execution of the printing operation is performed as follows. First, when the control means receives the print command, based on the elapsed time from when the previous print command was issued (that is, when the previous print command was issued and the carriage operation for printing was performed), Determine whether or not a stirring-only operation is necessary. When the elapsed time exceeds the predetermined time, the control unit causes the carriage 50A to perform the stirring-only operation. And a control means gives a printing command after completion | finish of operation only for stirring, and performs printing operation. When the elapsed time is within the predetermined time, the printing operation is performed without performing the stirring-only operation. In addition, the predetermined time is stored in advance in the control means as the time when the sediment is expected to be generated in the container 20 as described above.

  Further, whether or not the stirring-only operation of the carriage 50A is necessary may be determined in addition to the case where the print command is received or in other cases. For example, it may be performed when the liquid supply apparatus 100 is activated. In this case, first, when receiving the activation signal, the control means determines whether or not to perform the stirring-only operation based on the elapsed time since the previous carriage movement. If it is determined that the stirring-only operation is to be performed, the stirring-only operation is performed, and a print command is received or it is on standby until the necessity of the stirring operation is determined again. Further, when it is determined that the stirring-only operation is not performed, the printing-command is received without performing the stirring-only operation, or the process waits until the necessity determination for the stirring-only operation is performed again. In addition, what is necessary is just to acquire the elapsed time since the last carriage movement was performed using the above-mentioned time measuring means, for example.

  Note that the elapsed time from the previous carriage movement may be the elapsed time from the carriage movement in the previous printing operation, or the carriage movement in the previous stirring-only operation. It may be an elapsed time since the last time, or an elapsed time after any of the previous carriage movements.

  Further, the stirring-only operation can be performed before a predetermined time has elapsed. In this case, it becomes easy to prevent the generation of sediment by performing the exclusive stirring operation before the sediment is generated in the container 20.

1.7. Others The above-described embodiment shows a liquid supply apparatus having a so-called serial head in which a head is mounted on a carriage and a container mounted on the same carriage as the head. However, the liquid supply apparatus according to the present invention is not limited to this.

  For example, a liquid supply device having a serial head may be used in which the head and the container are mounted on separate carriages. In this case, at least the carriage on which the container is mounted may be reciprocated in a predetermined direction to perform the first operation as in the above-described embodiment. At this time, the reciprocating direction of the carriage on which the head is mounted and the carriage on which the container is mounted may be the same or different.

  Further, the liquid supply apparatus according to the present invention may have a so-called line-type head that is not mounted on the carriage and is formed wider than the width of the recording medium. Also in this case, the container may be mounted on the carriage, and the carriage may be reciprocated in a predetermined direction to perform the first operation as in the above-described embodiment.

1.8. Operational Effect In the liquid supply apparatus 100 according to the present embodiment, the stirrer 15 disposed in the container 20 moves in the container 20 based on the reciprocating motion of the carriage 50A. Therefore, the liquid composition in the container 20 can be sufficiently stirred by the stirrer 15, and the liquid composition with little variation in the component composition ratio can be supplied to the head 40.

  Further, in the liquid supply apparatus 100 according to the present embodiment, the specific gravity of the stirrer 15 is 0.8 times or more the specific gravity of the pigment contained in the liquid composition. The sediment containing the accumulated pigment can be agitated while being pushed apart, and the sediment in the container 20 can be redispersed in the liquid composition. Thereby, the liquid supply apparatus 100 excellent in stirring efficiency can be obtained.

2. Droplet Discharge Device A droplet discharge device according to the present invention includes the above-described liquid supply device. In the present embodiment, a droplet discharge device 300 having the liquid supply device 100 will be described. The droplet discharge device 300 according to this embodiment is a so-called inkjet printer.

  FIG. 3 is a perspective view schematically showing a droplet discharge device 300 including the liquid supply device 100. As shown in FIG. 3, the droplet discharge device 300 according to the present embodiment can include a control unit 60, a storage unit 10, a tube 30, a drive unit 50, and a paper feed unit 70.

  Since the container 10, the tube 30, and the liquid composition stored in the container 10 have been described in “1. Liquid supply device”, description thereof will be omitted.

  The control unit 60 can be shared with the control means described in the liquid supply apparatus 100, and can be configured using a computer having a CPU and a memory. The control unit 60 has a function of controlling the liquid storage unit 10, the driving unit 50, and the paper feeding 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 connected to the control unit 60 via the flexible cable 62 and is controlled by the control unit 60.

  The drive unit 50 has a function of reciprocating the carriage 50A in a predetermined direction MSD. Specifically, the driving belt 50B connected to the carriage 50A is driven by the power of the carriage motor 50C as a driving source of the carriage 50A, and the carriage 50A is reciprocated in a predetermined direction MSD.

  As described in “1. Liquid supply device”, the container 20 and the head 40 are mounted on the carriage 50A. When the carriage 50A is moved in the predetermined direction MSD, droplets are appropriately discharged from the head 40, and printing on the recording paper P is performed.

  The head 40 can have a plurality of nozzles that eject droplets. Further, the method of discharging the droplets of the head 40 is not particularly limited, and for example, an inkjet discharge method can be used. As the inkjet discharge method, any conventionally known method can be used, and examples thereof include a piezo inkjet and a thermal jet inkjet.

  The paper feed unit 70 includes a paper feed motor (not shown) serving as a drive source thereof, and a paper feed roller 72 that rotates by the operation of the paper feed motor. The paper feeding unit 70 can transport the recording paper P in the sub-scanning direction that intersects the predetermined direction MSD.

  Since the droplet discharge device 300 according to the present embodiment includes the liquid supply device 100 described above, the droplet contained in the liquid composition in the container 20 can be sufficiently stirred, and the droplets have little variation in the component composition ratio. Can be discharged.

  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.

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.

Titanium dioxide (average particle size 200 nm, specific gravity 4.3): 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

3.2. Preparation of measurement sample 3.2.1. Example 1
(1) Preparation of sample for measuring absorbance recovery rate A stirrer is arranged inside, and a cylindrical container having an inner dimension of 16 mm in diameter and a height of 60 mm is used. It was filled and sealed with the white ink composition prepared in “Preparation of ink composition”. Subsequently, the titanium dioxide and the solvent contained in the white ink composition in the container were separated using a centrifuge. Centrifugation was performed for 30 minutes under the conditions of a rotation radius of 21 cm and a centrifugal acceleration of 600 rpm.

  Thereafter, the container was attached to the carriage of an inkjet printer (product name “EPSON PX-G930”, manufactured by Seiko Epson Corporation) so that the longitudinal direction (height 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.

  Subsequently, the white ink composition in the container was stirred by reciprocating a distance of 23 cm a predetermined number of times at a speed of 46 cm / sec. The stirrer reciprocated once in the container every time the carriage reciprocated once. Thereafter, 1 g of the liquid in the container was taken out, and the absorbance recovery rate measurement sample according to Example 1 was obtained.

The stirrer used was a sphere (diameter 10 mm, volume 0.52 cm ³ ), and the material was stainless steel (specific gravity 7.9).

(2) Preparation of measurement sample for whiteness evaluation test Using the container and stirrer used in the above “3.2.1. Example 1 (1)”, the inside of the container is the above “3.1. White ink composition” The white ink composition prepared in “Preparation of product” was filled and sealed. And centrifugation operation was performed on the conditions similar to said "3.2.1. Example 1 (1)."

  Thereafter, the container was attached to the carriage of an inkjet printer (product name “EPSON PX-G930”, manufactured by Seiko Epson Corporation) so that the longitudinal direction (height direction) of the container was parallel to the moving direction (horizontal direction) of the carriage. . In “3.2.1. Example 1 (1)”, the container was hermetically sealed. However, in the preparation of this evaluation sample, the ink composition was supplied into the container without sealing the container. The container and the head were connected to the container so that the ink composition could be supplied from the container to the head.

  Thereafter, the white ink composition in the container was stirred by reciprocating a distance of 23 cm a predetermined number of times at a speed of 46 cm / sec. The stirrer reciprocated once in the container every time the carriage reciprocated once. Then, the white ink composition in the container is ejected from the head onto a recording medium (rolled polyester film, product name “EPSON ClearProof Film WXCPF24R”, manufactured by Seiko Epson Corporation), and the feeding direction of the recording medium of the ink jet printer A stripe pattern consisting of 10 orthogonal lines was continuously printed and dried at 24 ° C. for 1 hour. In this way, a sample for measuring whiteness according to Example 1 was obtained.

  One line forming the stripe pattern has a length in the width direction of the recording medium of 593 mm and a width in the feeding direction of the recording medium of 27 mm. The amount of ink used to obtain one line forming the stripe pattern was 0.4 ml.

3.2.2. Example 2
(1) Preparation of sample for measurement of absorbance recovery rate In preparation of the sample for measurement of absorbance recovery rate according to Example 2, the above-mentioned "except for using aluminum oxide (specific gravity 3.9) as the material of the stirrer" 3.2.1 Example 1 Same as “(1)”. The stirrer used was obtained by sintering aluminum oxide powder into a sphere, and the specific gravity was 3.6. In this way, a sample for measuring the absorbance recovery rate according to Example 2 was obtained.

(2) Preparation of measurement sample for whiteness evaluation test “3.2.1. Example 1 (2) except that the stirrer of“ 3.2.2. Example 2 (1) ”above was used. In the same manner as above, a whiteness measurement sample according to Example 2 was obtained.

3.2.3. Comparative Example 1
(1) Preparation of sample for measuring absorbance recovery rate In preparing the sample for measuring absorbance recovery rate according to Comparative Example 1, the above “3” was used except that glass (specific gravity 2.5) was used as the material of the stirrer. 2.2.1 Example 1 (1) ”. In this way, a sample for measuring the absorbance recovery rate according to Comparative Example 1 was obtained.

(2) Preparation of sample for measurement of whiteness evaluation test “3.2.1. Example 1 (2) except that the stirrer of“ 3.2.3. Comparative Example 1 (1) ”above was used. In the same manner as above, a whiteness measurement sample according to Comparative Example 1 was obtained.

3.2.4. Comparative Example 2
(1) Preparation of Sample for Measuring Absorbance Recovery Rate In Comparative Example 2, the white ink composition was filled in a container using the same container and stirrer as in Comparative Example 1. And the titanium dioxide contained in the white ink composition in a container and the solvent were isolate | separated with the centrifuge on the conditions similar to said "3.2.1. Example 1 (1)." Next, without placing the container on the inkjet printer, the container was shaken strongly by a predetermined number of times in the longitudinal direction of the container by hand to stir the white ink composition inside the container. Thereafter, 1 g of the liquid in the container was taken out, and a sample for measuring the absorbance recovery rate according to Comparative Example 2 was obtained.

3.3. Evaluation Test (1) Evaluation Test of Absorbance Recovery Rate Distilled water was added to 1 g of the samples of Examples 1 to 2 and Comparative Examples 1 to 2 obtained as described above and diluted 1000 times. Next, the absorbance (Abs value) of the diluted white ink composition at a wavelength of 500 nm was measured for each number of stirring 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 above centrifugation operation, and the absorbance recovery rate was determined using the following formula (1).

Absorbance recovery rate (%) = 100 × (absorbance of each sample) / (absorbance before centrifugation operation) (1)
From the obtained recovery rate values, evaluations were made by comparing the recovery rates for each number of stirrings (reciprocation times) in Examples 1 to 2 and Comparative Examples 1 to 2. 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.

(2) Whiteness evaluation test As a reference pattern, using the white ink composition immediately after the adjustment in “3.1. Preparation of white ink composition” and in which no sedimentation of contained components occurs, the above “ 3.2.1 Example 1 In the same manner as (2), a printed pattern of 10 lines was used.

  Then, the difference in whiteness was visually determined by comparing the reference pattern with the samples of Examples 1 to 2 and Comparative Example 1 obtained as described above. In addition, the reference pattern had no difference in whiteness among the 10 lines visually.

The classification of evaluation criteria for the whiteness evaluation test is as follows.
A: Among the stripe patterns composed of 10 lines, there was no line in which the difference in whiteness as compared with the reference pattern was conspicuous.
(Triangle | delta): Of the stripe pattern which consists of 10 lines, the line in which the difference in whiteness compared with a reference | standard pattern is somewhat conspicuous was seen.
X: Among the stripe patterns composed of 10 lines, a pattern in which the difference in whiteness was significantly conspicuous as compared with the reference pattern was observed.

3.4. Evaluation results Results of absorbance recovery rate for each number of stirrings in Examples 1 to 2 and Comparative Examples 1 to 2, and results of whiteness evaluation tests in Examples 1 to 2 and Comparative Example 1, Is also shown in Table 1. Moreover, the result of the evaluation test of the absorbance recovery rate in Examples 1 to 2 and Comparative Example 1 is shown in FIG.

  As shown in Table 1 and FIG. 4, when the liquid supply apparatus having the stirrer of Example 1 and Example 2 is used, it is possible to obtain a printed matter that is excellent in the recovery rate of absorbance and has little decrease in whiteness. It could be confirmed. As shown in Table 1 and FIG. 4, when the liquid supply apparatus having the stirrer of Example 1 and Example 2 is used, the absorbance recovery rate is excellent even when the number of stirrings is small, and the whiteness is decreased. It was confirmed that a printed matter with a small amount could be obtained.

  On the other hand, the specific gravity of the stirring bar used in Comparative Example 1 is less than 0.8 times the specific gravity of titanium dioxide. Therefore, as shown in Table 1 and FIG. 4, it is confirmed that when the liquid supply apparatus having the stirrer used in Comparative Example 1 is used, a printed matter having a significantly reduced whiteness can be obtained without an excellent recovery rate of absorbance. did it. In particular, as shown in Table 1 and FIG. 4, when the liquid supply apparatus having the stirrer used in Comparative Example 1 is used, when the number of stirring is small, the absorbance recovery rate is remarkably reduced, and the whiteness is remarkably reduced. It was confirmed that the printed material obtained was obtained.

  Moreover, the sample for evaluation in Comparative Example 2 was excellent in absorbance recovery rate. However, the container is agitated by hand and is not agitated by moving the carriage. Therefore, the agitation work becomes complicated, and it is not suitable for application to an ink jet printer.

  In addition, when evaluation by the number of stirrings of 11 in each example and comparative example in Table 1 was also performed at the number of stirrings of 10, the same evaluation result as the case of the number of stirrings of 11 was obtained.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purposes and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 10 Liquid storage part, 15 Stirrer, 20,120,220 Container, 22 Bottom face part, 24 Upper surface part, 26 1st side part, 28,128,228 2nd side part, 30, 30a, 30b Liquid supply pipe, 40 Head, 50 drive unit, 50A carriage, 50B drive belt, 50C carriage motor, 60 control unit, 62 flexible cable, 70 paper feed unit, 72 paper feed roller, 100 liquid supply device, 122, 222 cylindrical part, 300 droplet ejection apparatus

Claims (8)

A container for containing a liquid composition containing a pigment;
A head for discharging the liquid composition;
The liquid composition is connected to the storage section and the head via a supply path for supplying the liquid composition, and the liquid composition is supplied from the storage section to supply the liquid composition to the head, and has a stir bar inside. A container,
A carriage on which the container is mounted;
Have
The carriage can reciprocate in a predetermined direction,
The stirrer moves in the container based on the reciprocating motion of the carriage,
The liquid supply apparatus, wherein the specific gravity of the stirrer is 0.8 times or more the specific gravity of the pigment. In claim 1,
The liquid supply apparatus, wherein the specific gravity of the stirrer is 3.6 or more. In claim 1 or claim 2,
The shape of the said stirring element is a liquid supply apparatus which is a spherical body or an ellipsoid. In any one of Claims 1 thru | or 3,
The liquid supply apparatus, wherein the specific gravity of the stirring bar is not more than twice the specific gravity of the pigment. In any one of Claims 1 thru | or 4,
The liquid supply apparatus, wherein the specific gravity of the stirring bar is 10 or less. In any one of Claims 1 thru | or 5,
The liquid supply apparatus, wherein the head is mounted on the carriage. In claim 6,
The carriage can perform a first operation for performing the reciprocating operation without an operation for discharging the liquid composition from the head,
In the first operation, the liquid supply device reciprocates the carriage 10 times or more. In claim 6 or claim 7,
The carriage performs a first operation for performing the reciprocating operation without an operation for ejecting the liquid composition from the head, and a second operation for performing the reciprocating operation with an operation for ejecting the liquid composition from the head. And is possible,
The liquid supply apparatus, wherein the first operation is performed at least when a predetermined time has elapsed since the carriage stopped.

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