JP2006272734A - Waste ink liquid absorber and inkjet type recorder including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste ink liquid absorber whereby waste ink discharged from a waste liquid tube is easily absorbed even when the waste ink is of a bubbling type in a waste liquid tank of an inkjet recorder, and to provide an inkjet type recorder including the waste ink liquid absorber. <P>SOLUTION: The waste ink liquid absorber 32 is for a waste ink tank 31 of the inkjet type recorder. An impregnation liquid including a resin hard to dissolve in water is included in a part which includes at least a contact surface to the waste ink liquid. The inkjet type recorder includes the waste ink liquid absorber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a waste ink liquid absorber and an ink jet recording apparatus including the same.

  In an ink jet recording apparatus, flushing is performed to prevent drying of a discharge port of a recording head. This is an operation for empty ejection of ink from the ejection port separately from the recording control signal. In addition, when the ejection port of the recording head is clogged, the ejection port of the recording head is sealed with a capping unit, and ink is forcibly discharged from the ejection port by a suction unit connected to the capping unit. The operation is performed. By these flushing and cleaning, the ink ejected from the ejection port without being used for recording is received by the capping means, and is transported as a waste liquid to a waste liquid tank provided in the ink jet recording apparatus by the suction means. Even in borderless printing, the ink discharged to the outside of the recording medium is conveyed to a waste liquid tank through a capturing material provided on the platen.

  For example, FIG. 8 shows an ink jet recording apparatus including a waste liquid tank for waste ink by the above flushing and cleaning. FIG. 8 is a partial perspective view of the ink jet recording apparatus 10, and particularly shows the structure of the printing unit 40 and the ink waste liquid transport unit 70. For example, the printing unit 40 includes a carriage 42 on which an ink cartridge is placed, a recording head 44 that ejects ink, a shaft hole 46 provided in the carriage 42, and a shaft hole 46 that passes through the carriage 42 in the feeding direction. A guide shaft 48 is slidably supported in a substantially vertical direction. The recording head 44 has a plurality of ink ejection openings arranged along the feeding direction of the recording material 11. The printing unit 40 further includes a timing belt 402, a carriage motor 404, a black ink cartridge 406, and a color ink cartridge 408.

  When the carriage motor 404 drives the timing belt 402, the carriage 42 is guided by the guide shaft 48 and reciprocates substantially at right angles to the feeding direction of the recording material 11. A recording head 44 including a black ink discharge port and a color ink discharge port is mounted on the side of the carriage 42 facing the recording material. A black ink cartridge 406 and a color ink cartridge 408 for supplying ink to the recording head 44 are detachably mounted on the carriage 42.

  The ink jet recording apparatus 10 further includes an ink waste liquid transport unit 70 and a wiping unit 80 that transport ink discharged from the recording head 44 as waste liquid. The ink waste liquid transport unit 70 includes a capping unit 72 that seals the ejection port of the recording head 44. Further, the ink waste liquid transporting unit 70 is a pump that transports ink inside the tube 74 by elastically deforming the connection tube 74 and a part of the tube 74 from the ejection port of the recording head 44 to the capping unit 72 as an example of the suction unit. 76. The ink waste liquid transport unit 70 further includes a waste liquid tank 100 that accumulates the ink transported by the pump 76. The capping means 72 of the ink waste liquid transport unit 70 is arranged in a non-recording area (home position) outside the recording area (feeding path of the recording material 11). The recording material 11 is conveyed by a conveyance roller (not shown) and a discharge roller 52. The wiping means 80 has elasticity and is arranged in the vicinity of the end of the capping means 72 on the recording area side.

  When the ink jet recording apparatus 10 having the above configuration does not perform recording, the carriage 42 moves from the recording area to the non-recording area (home position). When the recording head 44 provided on the carriage 42 has moved directly above the home position, the capping means 72 can move up to the carriage 42 side and seal the surface of the recording head 44 having the ejection opening.

  The capping unit 72 can suppress drying of the ejection port of the recording head 44 by sealing the surface of the recording head 44 having the ejection port. In addition, the capping unit 72 can cause the recording head 44 to perform a flushing operation for ejecting ink droplets in an idle manner and receive the ink ejected in an idle manner. This flushing is performed, for example, by applying a drive signal unrelated to recording to the recording head 44.

  In a state where the capping unit 72 seals the recording head 44, the pump 76 sucks air in the internal space formed by the recording head 44 and the capping member 72, thereby forcing ink from the ejection port of the recording head 44. Is sucked out. The ink is forcibly sucked and discharged from the ejection port of the recording head 44, whereby the recording head 44 is cleaned and clogging of the ejection port is eliminated.

  When the carriage 42 returns from the non-recording area to the recording area, it first disengages from the capping means 72. Further, as the carriage 42 moves to the non-recording area side, the wiping means 80 advances onto the moving path of the recording head 44 and wipes ink on the nozzle formation surface of the recording head 44.

  The ink received by the capping unit 72 due to the cleaning and flushing is sucked by the pump 76 of the ink waste liquid transport unit 70 and passes through the tube 74 having one end connected to the capping unit 72, and the other end of the tube 74. To the waste liquid tank 100 connected to.

  Here, if the waste liquid tank 100 is sealed, the drying of the waste ink is hindered, and the waste liquid tank is quickly filled with the waste ink, and it is difficult to hold the expected amount of waste ink. On the other hand, if the upper surface of the waste liquid tank is opened to form a tray-like container in order to reduce the volume by drying the ink and increase the amount of waste ink, the ink jet recording apparatus 10 vibrates during recording. May be scattered or the ink jet recording apparatus 10 may be inclined to cause ink to flow out. Therefore, in general, the waste liquid tank 100 stores an absorber that absorbs the waste ink liquid.

  The waste liquid tank 100 generally includes an ink reservoir (that is, a waste ink diffusion chamber) and an absorber disposed around the ink reservoir (that is, an absorber holding chamber). After the waste ink conveyed from the tube 74 is stored in the waste ink diffusion chamber, the waste ink is absorbed from the absorption surface of the absorber. However, among the components contained in the waste ink liquid, the pigment component is less likely to be absorbed by the absorber than the solvent component and the water component. In particular, in a pigment ink in which the pigment component of the ink is a pigment, only the solvent component and the water component penetrate into the absorber, and the pigment particles tend to deposit on the surface of the absorber.

  In the aqueous pigment ink, a water-based pigment ink containing a water-insoluble dispersible polymer for the main purpose of achieving both color developability on plain paper (for example, Patent Document 1) and color developability and gloss of plain paper. (For example, Patent Document 2) has been developed. Various improvements have also been proposed for the structure of the waste liquid tank of the ink jet recording apparatus. For example, a technique for tilting the bottom surface of the waste ink diffusion chamber of the waste liquid tank is known (for example, Patent Document 3).

JP 2005-15765 A JP 2004-75988 A JP 2004-34361 A

  In the ink jet recording apparatus using the aqueous pigment ink described in Patent Document 1 and Patent Document 2, there is a phenomenon that the waste ink is more difficult to be absorbed by the absorber in the waste ink tank than in the case of the conventional pigment ink. It has occurred. Specifically, the pigment particles dispersed by the water-insoluble polymer tend to be more easily deposited on the surface of the absorber because only the solvent component and the water component penetrate into the absorber, compared to conventional pigment particles. Furthermore, since the waste ink discharged from the waste liquid tube into the waste ink diffusion chamber in the waste ink tank is foamed, if the foam remains, it is more difficult for the absorber to absorb, and eventually the waste ink inside the waste liquid tube. Since waste ink accumulates, flushing and cleaning cannot be performed even if the absorber itself has a sufficient absorption capacity.

  Accordingly, an object of the present invention is to provide a technique that can easily be absorbed by an absorber even if the waste ink discharged from the waste liquid tube is bubbled in the waste liquid tank of the ink jet recording apparatus. In particular, an object of the present invention is to provide a technique that is easily absorbed by an absorber even when a pigment ink containing a water-insoluble dispersible polymer is used.

  According to the present invention, the above-mentioned problem is a waste ink absorber for waste ink of an ink jet recording apparatus, and includes an impregnating liquid containing at least a poorly water-soluble resin in a part including at least a contact surface with the waste ink liquid. This can be solved by the waste ink liquid absorber.

  In a preferred embodiment of the waste ink liquid absorber according to the present invention, the absorber holding of the waste ink tank having a waste ink diffusion chamber not filled with the waste ink liquid absorber and an absorber holding chamber filled with the waste ink liquid absorber. Fill the chamber.

  In another preferred embodiment of the waste ink liquid absorber according to the present invention, it is composed of a nonwoven fabric or a foam.

  In still another preferred embodiment of the waste ink liquid absorber according to the present invention, the nonwoven fabric contains regenerated cellulose fibers and / or polyacrylic fibers.

  In another preferred embodiment of the waste ink liquid absorber according to the present invention, a saturated polyester film layer is provided on at least a part of the surface.

  In a further preferred aspect of the waste ink liquid absorber according to the present invention, the waste ink liquid absorption extends from the surface of the waste ink liquid absorber contacting the waste ink diffusion chamber so as to protrude in the direction of the interior of the waste ink diffusion chamber. And a waste ink liquid absorber protrusion including at least the impregnation liquid.

  In still another preferred embodiment of the waste ink liquid absorber according to the present invention, the waste ink liquid absorber protrusion is made of polyurethane foam.

  In a further preferred aspect of the waste ink liquid absorber according to the present invention, the waste ink diffusion chamber is surrounded by the bottom surface of the waste ink tank, the top surface and the four side surfaces of the waste ink liquid absorber.

  Further, in still another preferred embodiment of the waste ink liquid absorber according to the present invention, the waste ink includes a pigment, the pigment, and the pigment can be dispersed in the ink composition. An ink composition containing at least a polymer that has a group and is not substantially dissolved in the ink composition, and water as a main solvent.

（式中、Ｒ１は水素原子又はメチル基を表し、Ｒ２は水素原子又は炭素数１〜２０のアルキル基を表し、ｎは１〜３０の数を表す）
で表されるモノマーＡ１、
式（II）：

（式中、Ｒ１、Ｒ２及びｎは式（Ｉ）で定義したものと同じ意味を表し、ｍは１〜３０の数を表し、［］内のオキシエチレン基及びオキシプロピレン基はブロック又はランダム付加のいずれであってもよい）で表されるモノマーＡ２、及び
式（III）：

（式中、Ｒ１、Ｒ２及びｎは、式（Ｉ）で定義したものと同じ意味を表す）
で表されるモノマーＡ３から選ばれる少なくとも一種のモノマー５〜４５重量％と、
（Ｂ）塩生成基を有するモノマー３〜４０重量％と、
（Ｃ）数平均分子量５００〜５００，０００のマクロモノマー５〜４０重量％と、
（Ｄ）前記モノマー（Ａ）、（Ｂ）、及び（Ｃ）と共重合可能なモノマー０〜８７重量％とを重合させてなるビニルポリマーである。 In still another preferred embodiment of the waste ink liquid absorber according to the present invention, the polymer is
(A) Formula (I):

(Wherein R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and n represents a number of 1 to 30)
Monomer A1 represented by
Formula (II):

(Wherein R1, R2 and n represent the same meaning as defined in formula (I), m represents a number of 1 to 30, and the oxyethylene group and oxypropylene group in [] are blocked or randomly added. And any one of the monomer A2 and the formula (III):

(Wherein R1, R2 and n represent the same meaning as defined in formula (I))
5 to 45% by weight of at least one monomer selected from monomers A3 represented by:
(B) 3 to 40% by weight of a monomer having a salt-forming group;
(C) 5 to 40% by weight of a macromonomer having a number average molecular weight of 500 to 500,000,
(D) A vinyl polymer obtained by polymerizing 0 to 87% by weight of a monomer copolymerizable with the monomers (A), (B), and (C).

（式中、Ｒ１、Ｒ２、ｍ及びｎは前記と同じ意味であり、オキシプロピレン基及びオキシテトラメチレン基はブロック付加又はランダム付加している）
で表されるモノマーＡ４からなる群より選ばれた１種以上のモノマーと、
（３）前記塩生成基を有するモノマー（Ｂ）と、
（４）前記モノマーＡ３、前記モノマーＡ１、前記モノマーＡ２、又は前記モノマーＡ４と、前記モノマー（Ｂ）、及び前記モノマー（Ｃ）と共重合可能なモノマーと
を重合させてなるビニルポリマーである。 In still another preferred embodiment of the waste ink liquid absorber according to the present invention, the polymer is
(1) the monomer A3;
(2) The monomer A1, the monomer A2, and the formula (IV):

(In the formula, R1, R2, m and n have the same meaning as described above, and the oxypropylene group and the oxytetramethylene group are block-added or randomly added)
One or more monomers selected from the group consisting of monomers A4 represented by:
(3) a monomer (B) having the salt-forming group;
(4) A vinyl polymer obtained by polymerizing the monomer A3, the monomer A1, the monomer A2, or the monomer A4, the monomer (B), and a monomer copolymerizable with the monomer (C).

  In another preferred embodiment of the waste ink liquid absorber according to the present invention, the poorly water-soluble resin includes acrylic monomers, methacrylic monomers, vinyl monomers, maleic acid, maleic anhydride, styrene, itaconic acid, N -It contains a poorly water-soluble resin obtained by polymerizing a monomer selected from the group consisting of vinylpyrrolidone, acrylamide, methacrylamide, and derivatives thereof.

  In still another preferred embodiment of the waste ink liquid absorber according to the present invention, the methacrylic monomer is selected from methyl methacrylate (MMA), ethyl methacrylate (EMA), propyl methacrylate, and n-butyl methacrylate (BMA). Or NBMA), hexyl methacrylate, 2-ethylhexyl methacrylate (EHMA), octyl methacrylate, lauryl methacrylate (LMA), stearyl methacrylate, phenyl methacrylate, hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate, ethoxy Triethylene glycol methacrylate (ETEGMA), 2-ethoxyethyl methacrylate, methacrylonitrile, 2-trimethylsiloxyethyl methacrylate, glycidyl methacrylate (GMA), methacrylic acid - tolyl, methacrylic acid (MAA), dimethylaminoethyl methacrylate (DMAEMA), diethylaminoethyl methacrylate, a monomer chosen t- butylaminoethyl methacrylate, and from the group consisting of methacrylic acid sorbyl.

  In another preferred embodiment of the waste ink liquid absorber according to the present invention, the acrylic monomer is methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate. Octyl acrylate, lauryl acrylate, stearyl acrylate, phenyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, acrylonitrile, 2-trimethylsiloxyethyl acrylate, glycidyl acrylate, p-tolyl acrylate, sorbyl acrylate A monomer selected from the group consisting of acrylic acid, dimethylaminoethyl acrylate, and diethylaminoethyl acrylate.

  In another preferred embodiment of the waste ink liquid absorber according to the present invention, a water-soluble solvent is further included.

  In still another preferred embodiment of the waste ink liquid absorber according to the present invention, at least one of the water-soluble solvents has a vapor pressure at 20 ° C. of 0.01 mmHg or less.

  The present invention also relates to an ink jet recording apparatus including the waste ink liquid absorber.

  In this specification, terms related to the “upper and lower” relationship with respect to the printer, such as “upper” or “lower”, “upper” or “lower”, “upper” or “lower”, and “upper” or “ “Directly above” or the like means a vertical relationship with respect to the direction of gravity in a state where printing is being performed by the printer.

  Since the waste ink liquid absorber according to the present invention includes the impregnating liquid at least in a portion including the contact surface with the waste ink liquid, even when the waste ink discharged from the waste liquid tube has a property that bubbles, Easily absorbed.

  In addition, when the waste ink liquid absorber according to the present invention has a waste ink liquid absorber protrusion that protrudes in the direction of the interior of the waste ink diffusion chamber and includes the impregnating liquid in the absorber protrusion, Absorbability by the absorber is further improved.

  Regarding the waste ink liquid absorber of the present invention, first, a waste ink tank capable of storing and using the waste ink liquid absorber will be described, and then the structure and materials of the waste ink liquid absorber will be described. The impregnating liquid and the ink composition will be described in order.

(A) Waste ink tank A waste ink tank capable of containing and using the waste ink liquid absorber of the present invention contains waste ink generated in each of the flushing and cleaning operations performed in the ink jet recording apparatus. The waste ink tank is not particularly limited, and further includes a waste ink tank that stores waste ink that is ejected to the outside of the recording medium in borderless printing and conveyed through a capturing material provided on the platen, A waste ink tank that simultaneously fulfills these functions is also included. The waste ink tank used in the present invention may be closed or open, and is preferably open.

  The waste ink tank used in the present invention preferably has a waste ink diffusion chamber and an absorber holding chamber. Here, the waste ink diffusion chamber is an internal space that does not include a waste ink liquid absorber, and is an interior into which a discharge port of a waste liquid tube that guides waste ink generated in each operation of flushing and cleaning to a waste ink tank is inserted. It is space. The absorber holding chamber is an internal space filled with the waste ink liquid absorber.

  FIG. 1 is a perspective view showing a state in which an absorber filled in an absorber holding chamber is removed from a waste ink tank 100 having a waste ink diffusion chamber and an absorber holding chamber. FIG. 6 is a perspective view showing a state in which an absorber 146 is filled in an absorber holding chamber of the waste ink tank 100 of FIG.

  The waste liquid tank 100 has a substantially rectangular parallelepiped main body 102 whose entire upper surface is opened. The waste liquid tank 100 is provided on a side surface of the waste ink diffusion chamber 104 along the waste ink diffusion chamber 104 and has an inclined bottom surface through which the waste ink flows, and an absorber that holds the waste ink liquid absorber 146. A holding chamber 106. The upper part of the waste ink diffusion chamber 104 is opened and is inclined in the direction of flowing ink (the direction of arrow A in the figure). The absorber holding chamber 106 has a tray shape with a bottom surface provided below the waste ink diffusion chamber 104 and an open top surface. Waste ink is conveyed from the capping means 72 to the waste liquid tank 100 through the tube 74. When this waste ink flows into the waste ink diffusion chamber 104, it flows downward along the inclined bottom surface of the waste ink diffusion chamber 104, that is, in the direction of arrow A in FIG. The bottom surface of the waste ink diffusion chamber 104 can be horizontal, or can be inclined toward the absorber holding chamber 106.

  FIG. 3 is a perspective view showing another example of the waste liquid tank. The waste liquid tank 180 shown in FIG. 3 has a substantially rectangular parallelepiped whose upper surface is opened. The waste liquid tank 180 includes a waste ink diffusion chamber 184 and an absorber holding chamber provided on a side surface of the waste ink diffusion chamber 184 along the waste ink diffusion chamber 184. The absorber holding chamber is filled with the absorber 186. Included. The waste ink diffusion chamber 184 is open at the top. In the waste liquid tank 180, ink waste liquid sub-channels 188a, 188b, and 188c for guiding ink in a direction intersecting with the waste ink diffusion chamber 184 (direction of arrow C in FIG. 3) are arranged. These ink waste liquid sub-channels 188 a, 188 b, and 188 c are open at the top and may have an inclined bottom surface that becomes lower as the distance from the waste ink diffusion chamber 184, or a horizontal bottom surface.

  The waste ink diffusion chamber used in the present invention may be an embodiment in which the waste ink diffusion chamber is surrounded by the bottom surface of the waste ink tank, the top surface and the four side surfaces of the waste ink liquid absorber.

  FIG. 4 (perspective view) and FIG. 5 (cross-sectional view) show a waste liquid tank including the waste ink diffusion chamber of such an embodiment.

  As shown in FIGS. 4 and 5, the waste liquid tank 15 includes a recovery container 31 and a waste ink liquid absorber 32. The collection container 31 is a box-shaped container whose upper side is opened. A substantially rectangular parallelepiped collection space S is formed inside the collection container 31. As shown in FIGS. 4 and 5, an insertion hole 31 b is provided on the right side surface 31 a of the collection container 31. The insertion hole 31b is a circular hole formed along the left-right direction X, and is formed to penetrate from the outside of the collection container 31 to the collection space S. Further, the insertion hole 31 b is formed in the approximate center of the right side surface 31 a and has a hole diameter that is substantially the same as the outer diameter of the discharge tube 22.

  As shown in FIG. 4, the waste liquid tank is provided with a collection container 31 and a waste ink liquid absorber 32. As shown in FIG. 4, the collection container 31 is a box-shaped container having an upper opening. A substantially rectangular parallelepiped collection space S is formed inside the collection container 31. As shown in FIGS. 4 and 5, an insertion hole 31 b is provided on the right side surface 31 a of the collection container 31. The insertion hole 31b is, for example, a circular hole and is formed so as to penetrate from the outside of the collection container 31 to the collection space S. Further, the insertion hole 31 b is formed, for example, in the approximate center of the right side surface 31 a and has a hole diameter that is substantially the same as the outer diameter of the discharge tube 22.

  As shown in FIG. 4, the discharge tube 22 is inserted through the insertion hole 31b. At the tip of the discharge tube 22, an annular discharge port 22a for discharging waste ink is formed. By disposing the discharge port 22a in the collection space S, the discharge tube 22 enables the discharge of waste ink into the collection space S (in the waste liquid tank) through the discharge port 22a.

  In the collection space S, as shown in FIG. 4, a waste ink liquid absorber 32 is accommodated. The waste ink liquid absorber 32 is formed of a porous member having a large number of pores, and is formed in a rectangular parallelepiped shape having substantially the same size as the recovery space S. The waste ink liquid absorber 32 can absorb the discharged ink into the pores by a capillary force or the like. In addition, the waste ink liquid absorber 32 can volatilize the ink to be absorbed at a predetermined volatilization rate through the upper opening of the collection container 31. That is, the waste ink liquid absorber 32 volatilizes the absorbed waste ink by an amount corresponding to the volatilization rate, and can reduce the capacity of the ink to be accommodated inside the pores.

  The waste ink liquid absorber 32 is discharged by a cleaning operation, for example, 50 times the unit discharge capacity, that is, 50 times, with the maximum capacity (saturation amount) of ink that can be stored being made to be relative to the total volume of the pores. The total capacity of waste ink can be obtained. Moreover, the waste ink liquid absorber 32 can be accommodated with a volatility rate of 50%, that is, with the capacity of the absorbed ink halved. In this case, the waste ink liquid absorber 32 (waste liquid tank) volatilizes 50% of the waste ink capacity by performing the cleaning operation 100 times, and the ink is 50 times the unit discharge capacity relative to the saturation amount. The inside of the pores can be filled. In other words, the waste liquid tank can be set to have a cleaning count (saturation cleaning count) of 100 times that the ink stored therein reaches the saturation amount.

  As shown in FIGS. 4 and 5, a recess 34 is formed at a position on the right side surface of the waste ink liquid absorber 32 and facing the insertion hole 31b. The recess 34 is formed by notching the lower center of the right side surface 31a of the waste ink liquid absorber 32 toward the left side. By forming this recess 34, a space in which the discharge port 22 a is accommodated and covered with the waste ink liquid absorber 32 (recess 34), that is, a waste ink diffusion chamber 35 is formed in the collection space S. Is done. Further, by forming the waste ink diffusion chamber 35, the space filled with the waste ink liquid absorber 32 excluding the waste ink diffusion chamber 35 is formed in the collection space S as shown in FIGS. That is, an absorber holding chamber is formed.

  As shown in FIGS. 4 and 5, the waste ink diffusion chamber 35 is a rectangular parallelepiped space formed by the recess 34 and the inner wall of the collection container 31. As shown in FIG. 5, the waste ink diffusion chamber 35 has an upper surface 35 a and a lower surface 35 b formed by the upper surface of the recess 34 and the container bottom surface 31 c of the collection container 31, respectively. For example, the volume of the waste ink diffusion chamber 35 is formed so as not to leak the waste ink by five consecutive cleaning operations, that is, a size that can accommodate the waste ink corresponding to five times the unit discharge amount. be able to.

  Between the upper surface 35a and the lower surface 35b of the waste ink diffusion chamber 35, as shown in FIG. As shown in FIGS. 4 and 5, the discharge port 22 a is preferably arranged so that the center thereof is located in the center in the left-right direction of the waste ink diffusion chamber 35 and in the center in the front-rear direction.

  When the waste ink is discharged from the discharge port 22a, the waste ink falls by its own weight and is poured onto the lower surface 35b facing the discharge port 22a. Then, the discharged ink poured onto the lower surface 35b isotropically diffuses outward from the center along the lower surface 35b due to the adhesive force and the like. Over time, most of the discharged ink that diffuses the lower surface 35b diffuses to the outside (absorber holding chamber side) of the waste ink diffusion chamber 35 along the container bottom surface 31c of the collection container 31, and the waste ink liquid absorber 32 It is absorbed and accommodated in the absorber holding chamber by capillary force or the like.

  The waste ink liquid absorber used in the present invention has a waste ink liquid absorber projecting portion that projects from the surface of the waste ink liquid absorber in contact with the waste ink diffusion chamber so as to project in the direction toward the inside of the waste ink diffusion chamber. It is preferable. An embodiment having the waste ink liquid absorber protrusion is shown in FIGS. FIG. 6 is a schematic partial enlarged perspective view showing the waste ink liquid absorber protruding portion 38 provided on the side surface of the waste ink liquid absorber 32 exposed to the waste ink diffusion chamber 35 together with the discharge port 22 a of the waste liquid tube 22. FIG. 7 is a sectional view thereof.

  The shape of the waste ink liquid absorber protrusion is not particularly limited, and may be any shape such as a prismatic shape, a cylindrical shape, a semi-cylindrical shape, a cone shape, or a hemispherical shape. The number of waste ink liquid absorber protrusions provided inside one waste ink diffusion chamber is not particularly limited, and two or more waste ink liquid absorber protrusions may be provided.

(B) Waste ink liquid absorber The waste ink liquid absorber used in the present invention can be made of, for example, a nonwoven fabric or a foam.

  The material of the waste ink liquid absorber can be the same material as that of a conventionally known waste ink liquid absorber. As the nonwoven fabric, for example, regenerated cellulosic fibers (particularly, rayon fibers) preferably have excellent water absorption and are therefore preferably used as constituent fibers. Moreover, it is also preferable to use a polyacrylic fiber having excellent water absorption, and using a polyacrylic fiber is preferable in terms of improving flame retardancy and facilitating cutting. Nonwoven fabrics consisting only of regenerated cellulosic fibers (especially rayon fibers) are superior in terms of water absorption, and can be suitably used, but they are too soft and easy to squeeze, during cutting, etc. It is more preferable to use a mixture of regenerated cellulosic fiber and polyacrylic fiber. For example, a combination of regenerated cellulosic fiber (particularly rayon fiber) 20 to 60% by weight (particularly 30 to 50% by weight) and polyacrylic fiber 80 to 40% by weight (particularly 70 to 50% by weight). Particularly preferred.

  The waste ink liquid absorber according to the present invention has the ability to hold more waste ink liquid and the ability to completely hold waste ink even when, for example, the printer is tilted 90 degrees, as in the case of the same type of conventional absorber. Desired. As the drying of the waste ink in the waste ink absorber proceeds, the ink can be completely retained, but the amount of waste ink retained decreases. If the waste ink is less dried, the amount of waste ink retained increases, but the waste ink cannot be completely retained, and the waste ink leaks when tilted. In order to achieve both of these performances, a small amount of saturated polyester fiber (for example, polyethylene terephthalate fiber) can be included in the nonwoven fabric, and waste ink can be infiltrated by capillary action. Further, the waste ink liquid absorber used in the present invention can be provided with a saturated polyester film layer on at least a part of the surface of the nonwoven fabric to prevent the absorbed waste ink from drying. As the saturated polyester, for example, polyethylene terephthalate is preferable.

As the foam, a resin foam, preferably a polyurethane foam (particularly, a flexible polyurethane foam) can be used. The flexible polyurethane foam to be used preferably has a density of 0.005 to 0.150 g / cm ³ , particularly 0.01 to 0.05 g / cm ³ , and the number of cells is 40 to 150/25 mm, particularly 60 It is preferable that it is -150 piece / 25mm. When compressing and using a flexible polyurethane foam, the number of cells is preferably 20 to 150/25 mm, more preferably 40 to 150/25 mm, and still more preferably 40 to 100/25 mm. The flexible polyurethane foam can be used as it is without being compressed (non-compressed foam) or after being compressed (compressed foam).

  When the waste ink liquid absorber according to the present invention has a waste ink liquid absorber protrusion, a nonwoven fabric is used for the main body of the waste ink liquid absorber, and a polyurethane foam (particularly, a flexible polyurethane foam) is used for the protrusion. Is preferred.

(C) Impregnation liquid The impregnation liquid according to the present invention contains a poorly water-soluble resin. This poorly water-soluble resin is contained in the impregnating liquid of the present invention in the form of an aqueous emulsion polymer.

  The poorly water-soluble resin used in the present invention includes acrylic monomers; methacrylic monomers; vinyl monomers (for example, vinyl acetate or vinyl chloride); maleic acid; maleic anhydride; styrene; itaconic acid; N-vinylpyrrolidone; Can be prepared from monomers selected from the group consisting of amides; and their derivatives.

  Typical acrylic or methacrylic monomers include methyl methacrylate (MMA), ethyl methacrylate (EMA), propyl methacrylate, n-butyl methacrylate (BMA or NBMA), hexyl methacrylate, 2-ethylhexyl methacrylate. (EHMA), octyl methacrylate, lauryl methacrylate (LMA), stearyl methacrylate, phenyl methacrylate, hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate, ethoxytriethylene glycol methacrylate (ETEGMA), 2-ethoxy methacrylate Ethyl, methacrylonitrile, 2-trimethylsiloxyethyl methacrylate, glycidyl methacrylate (GMA), zonyl fluoromethacrylate, p-tolyl methacrylate, methacrylate Sorbyl acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, phenyl acrylate, hydroxyethyl acrylate, Hydroxypropyl acrylate, acrylonitrile, 2-trimethylsiloxyethyl acrylate, glycidyl acrylate, p-tolyl acrylate, sorbyl acrylate, methacrylic acid (MAA), acrylic acid, dimethylaminoethyl methacrylate (DMAEMA), diethylamino methacrylate Ethyl, tert-butylaminoethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminopropyl methacrylamide, methacrylate Ruamido, acrylamide, and dimethyl acrylamide. Preferred acrylic or methacrylic monomers are poorly water-soluble resins prepared from methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, a combination of butyl methacrylate and methyl methacrylate, methacrylic acid, or dimethylaminoethyl methacrylate. is there.

The poorly water-soluble resin used in the present invention may contain a small amount of a crosslinkable monomer such as ethylene glycol dimethacrylate or ethylene glycol triacrylate. The poorly water-soluble resin has a general formula:
CH2 = C (X) (Y ′)
[Wherein X is H or CH 3, Y ′ is C (O) OH, C (O) NR 2 R 3, C (O) OR 4 NR 2 R 3, C (O) OR 5, or a salt thereof, and R 2 and Each R3 is independently H or an alkyl, aryl or alkylaryl group having 1 to 9 carbon atoms, R4 is an alkylene group having 1 to 5 carbon atoms, and R5 is optionally hydroxy A C1-C20 alkylene group which may contain a group or an ether group]
It is also possible to change the solubility to some extent by further containing a hydrophilic monomer represented by However, an amount of hydrophilic monomer sufficient to render the poorly water-soluble resin or salt thereof completely water-soluble should not be present in the poorly water-soluble resin.

  The poorly water-soluble resin used in the present invention can be stabilized with a monomeric or polymeric stabilizer. Useful monomeric stabilizers include N, N, N-trimethyl-1-dodecaninium chloride, di-methyl-dodecaninium chloride, polyethylene glycol derivatives of alkylphenols, sodium lauryl sulfate, and N-alkyltrimethylammonium chloride. There is. Commercially available monomeric stabilizers include, for example, dodecyltrimethyl ammonium chloride [Arquad (registered trademark); Akzo Chemicals Inc. Can be mentioned. Useful polymeric stabilizers include block polymers (such as diblock and triblock polymers) and structural polymers selected from the group consisting of graft polymers. As a useful diblock polymer, for example, a compound disclosed in US Pat. No. 5,085,698 can be used, and as a useful triblock polymer, for example, US Pat. No. 5,519,085 is used. The compounds disclosed in can be used. As useful graft polymers, for example, compounds disclosed in US Pat. No. 5,231,131 can be used.

  The impregnating liquid according to the present invention can contain, for example, a water-soluble solvent in addition to the poorly water-soluble resin. Examples of the water-soluble solvent include glycerin, 1,2,6-hexanetriol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, 2-butene-1,4-diol. 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, 1,2-octanediol, 1,2-hexanediol, 1,6-hexanediol, 2,5-hexanediol Polyhydric alcohols such as 1,2-pentanediol, 1,5-pentanediol, 4-methyl-1,2-pentanediol, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol , Sec C1-C5 alkyl alcohols such as butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene Glycol mono-n-butyl ether, ethylene glycol Cole mono-t-butyl ether, diethylene glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether , Propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, propylene glycol mono-n-butyl ether , Glycol ethers such as dipropylene glycol mono-n-butyl ether, dimethylformamide Amides such as dimethylacetamide, ketones or ketone alcohols such as acetone and diacetone alcohol, ethers such as dioxane, 2-pyrrolidone, N-methyl-2-pyrrolidone, and sulfolane. These water-soluble solvents can be used alone or in combination of two or more. Further, from the viewpoint of preventing drying of the ink captured by the capturing member, it is preferable that at least one of these water-soluble solvents has a high boiling point and low volatility with a vapor pressure at 20 ° C. of 0.01 mmH or less. It is more preferable that the vapor pressure in is 0.005 mmHg or less.

  The impregnating liquid according to the present invention may contain, for example, a solid humectant, a pH adjuster, a surfactant, an antiseptic / antifungal agent and the like in addition to the poorly water-soluble resin and the water-soluble solvent.

  Examples of the solid moisturizer include those having a melting point of 20 ° C. or higher and a solubility in water at 20 ° C. of 5% by weight or more, specifically 1,4-butanediol, 2,3-butanediol. , Alcohols such as 2-ethyl-2- (hydroxymethyl) -1,3-propanediol, esters such as ethylene carbonate, acetamide, N-methylacetamide, 2-pyrrolidone, ε-caprolactam, urea, thiourea, Nitrogen compounds such as N-ethylurea, dihydroxyacetone, erythritol, D-arabinose, L-arabinose, D-xylose, 2-deoxy-β-D-ribose, D-lyxose, L-lyxose, D-ribose, D- Arabitol, ribitol, D-altrose, D-allose, D-galactose, L-galactose, D-quinobose , D-glucose, D-digitalose, D-digitoxose, D-simarose, L-sorbose, D-tagatose, D-talose, 2-deoxy-D-glucose, D-fucose, L-fucose, D-fructose, D Mannose, L-rhamnose, D-inositol, myo-inositol, D-glucitol, D-mannitol, methyl = D-galactopyranoside, methyl = D-glucopyranoside, methyl = D-mannopyranoside, N-acetylchitobiose , Isomaltose, xylobiose, gentiobiose, cordobiose, chondrosin, sucrose, cellobiose, sophorose, α, α-trehalose, maltose, melibiose, lactose, laminaribiose, lutinose, gentianose, stachyose, cellotrio Saccharides such as glucose, planteose, maltotriose, melezitose, lacto-N-tetraose, and raffinose.

  As the pH adjuster, it is possible to use alkali metal hydroxides such as lithium hydroxide, potassium hydroxide and sodium hydroxide, amines such as ammonia, triethanolamine, tripropanolamine, diethanolamine and monoethanolamine. I can do it. Further, collidine, imidazole, phosphoric acid, 3- (N-morpholino) propanesulfonic acid, tris (hydroxymethyl) aminomethane, boric acid and the like can be mentioned as necessary.

  As the surfactant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant and a nonionic surfactant can be contained. Specific examples of nonionic surfactants include acetylene glycol surfactants, acetylene alcohol surfactants, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkylallyl. Ethers such as ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene oleic acid, polyoxyethylene oleic acid ester, polyoxyethylene distearic acid ester, Sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene Monooleate, polyoxyethylene stearate, etc. esters, silicone surfactant of dimethylpolysiloxane, other fluorine alkyl esters and fluorine-containing surfactants such as perfluoroalkyl carboxylic acid salt. Among the nonionic surfactants, acetylene glycol surfactants and acetylene alcohol surfactants are particularly preferable in that they have less foaming and excellent defoaming performance. As further specific examples of the acetylene glycol surfactant and the acetylene alcohol surfactant, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4- Examples include octyne-3,6-diol, 3,5-dimethyl-1-hexyne-3ol, and are also commercially available. For example, Surfynol 104, 82, 465 manufactured by Air Products, 485, TG, Olphine STG manufactured by Nisshin Chemical Co., Ltd., Olphine E1010 and the like.

  Examples of antiseptics and fungicides include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbitanate, sodium dehydroacetate, or 1,2-benzisothiazolin-3-one (Arch). Chemicals Inc., Proxel BZ, Proxel BD20, Proxel GXL, Proxel XL2, or Proxel TN).

  The use forms of the water-soluble solvent, solid humectant, pH adjuster, surfactant, and / or preservative described above may be used alone or in a mixed solution state. The mixing ratio can be appropriately determined according to the workability of impregnation into the waste ink liquid absorber, the type of pigment ink used, and the like, and is not particularly limited as long as the intended effect can be secured. For example, the addition amount of the pH adjuster needs to be added so that at least the pH of the whole mixed solution is 7 or more, but other conditions can be appropriately determined according to the type of pigment ink used. . There is no problem with the addition amount of the preservative as long as the antiseptic effect is sufficiently obtained.

  The impregnating liquid may be included in the waste ink liquid absorber by applying it to the surface of the waste ink liquid absorber or by immersing the waste ink liquid absorber in the impregnating liquid filled in the container. it can.

  In the waste ink liquid absorber according to the present invention, the entire waste ink liquid absorber can be impregnated with the impregnation liquid, but the impregnation liquid is included in at least a portion including a contact surface with the waste ink liquid. Here, the portion including the contact surface with the waste ink liquid is, for example, the waste ink diffusion chamber 35 in the case of the waste ink liquid absorber 32 to be mounted on the waste liquid tank 15 in the mode shown in FIGS. The contact surface. That is, of the six planes of the waste ink diffusion chamber 35, except for the bottom surface and one side surface formed by the collection container 31, the three side surfaces and the top surface are portions including the contact surface with the waste ink liquid. The impregnation liquid is included in each surface. 1 and FIG. 2 and the waste ink tank 180 of the embodiment shown in FIG. 3 also have contact surfaces with the waste ink diffusion chamber 104 and the waste ink diffusion chamber 184, and the waste ink liquid. The impregnating liquid is included on each of the surfaces. Further, in the case of an ink jet recording apparatus that performs borderless printing, the surface of the waste ink that is conveyed through the capturing material provided on the platen contacts the waste ink liquid absorber is the surface that contacts the waste ink liquid. The impregnating liquid is included on each of the surfaces.

  When the waste ink liquid absorber according to the present invention has, for example, a waste ink liquid absorber protrusion as shown in FIGS. 6 and 7, the waste ink liquid absorber protrudes at least with the waste ink liquid. The impregnating liquid is included in the portion including the contact surface. Alternatively, the entire impregnating portion of the waste ink liquid absorber can be impregnated with the impregnating liquid.

  The waste ink liquid absorber according to the present invention may contain the impregnating liquid in a wet state or a dry state, but is preferably in a wet state. The contents of the humectant and the base in the impregnating liquid of the present invention are not particularly limited. In the case of waste ink having a foaming property by supporting the impregnating liquid of the present invention on a waste ink liquid absorber. However, there is no particular limitation as long as the waste ink can be easily absorbed by the absorber, but it is preferably 3 g / g or more.

(D) Ink Composition The waste ink liquid absorber according to the present invention can be used for the waste ink treatment of any ink composition used in the ink jet recording method. Can be used for waste ink treatment of an aqueous pigment ink composition (for example, the aqueous pigment ink composition described in Patent Document 1 or 2).

That is, the waste ink liquid absorber according to the present invention is:
(1) a pigment;
(2) a polymer including the pigment and capable of dispersing the pigment in the ink composition, having a hydrophobic group and a hydrophilic group, and substantially not dissolved in the ink composition;
(3) It can be advantageously used for waste ink treatment of an ink composition containing at least water as a main solvent.

  As the pigment, organic pigments conventionally used in ink compositions for inkjet can be used. Examples of organic pigments include azo pigments (for example, azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone). Pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, or quinophthalone pigments), nitro pigments, nitroso pigments, aniline black, and the like.

  Examples of the cyan pigment used as the cyan ink composition include C.I. I. Pigment Blue 15: 3, 15: 4, and 60 are preferably used. I. Pigment Blue 15: 4 is preferable.

  Examples of the magenta pigment used as the magenta ink composition include C.I. I. Pigment Red 122, 202, 209, and Pigment Violet 19 are preferably used. I. Pigment red 122 and C.I. I. Pigment Violet 19 is preferable.

  Examples of the yellow pigment used as the yellow ink composition include C.I. I. Pigment Yellow 74, 93, 109, 110, 128, 138, 150, 151, 154, 155, and 180 are preferably used.

  The polymer (2) has a hydrophobic group and a hydrophilic group, can be dispersed in water while including a pigment, and is substantially not dissolved in the ink composition. The polymer (2) preferably has an acid value of 30 to 125 KOH mg / g, a more preferable lower limit is 50 KOH mg / g, and a more preferable upper limit is 100 KOH mg / g.

  The polymer (2) preferably has a number average molecular weight of 1,000 to 200,000, a more preferred lower limit is 3,000, and a more preferred upper limit is 150,000. Further, the polymer (2) is adjusted to a pigment inclusion step or an ink composition blending step described later so that the salt generation rate of a dissociative hydrophilic group (for example, carboxyl group), that is, the neutralization rate is less than 100%. Is done. The lower limit of the neutralization rate is preferably 60%, and the upper limit is preferably 95%.

  The hydrophobic group possessed by the polymer (2) is preferably at least one selected from an alkyl group, a cycloalkyl group and an aromatic ring. Preferable examples of the aromatic ring include aryl groups (eg, phenyl group, naphthyl group, anthryl group) and derivatives thereof. The hydrophilic group is preferably at least one selected from a carboxyl group, a sulfonic acid group, a hydroxyl group, an amino group, an amide group, and a base thereof. The polymer (2) can be obtained from a monomer or oligomer having an acryloyl group, methacryloyl group, vinyl group or allyl group having a double bond.

（式中、Ｒ１は水素原子又はメチル基を表し、Ｒ２は水素原子又は炭素数１〜２０のアルキル基を表し、ｎは１〜３０の数を表す）
で表されるモノマーＡ１、
式（II）：

（式中、Ｒ１、Ｒ２及びｎは式（Ｉ）で定義したものと同じ意味を表し、ｍは１〜３０の数を表し、［］内のオキシエチレン基及びオキシプロピレン基はブロック又はランダム付加のいずれであってもよい）で表されるモノマーＡ２、及び
式（III）：

（式中、Ｒ１、Ｒ２及びｎは、式（Ｉ）で定義したものと同じ意味を表す）
で表されるモノマーＡ３から選ばれる少なくとも一種のモノマー５〜４５重量％と、
（Ｂ）塩生成基を有するモノマー３〜４０重量％と、
（Ｃ）数平均分子量５００〜５００，０００のマクロモノマー５〜４０重量％と、
（Ｄ）前記モノマー（Ａ）、（Ｂ）、及び（Ｃ）と共重合可能なモノマー０〜８７重量％とを重合させてなるビニルポリマーであることができる。 The polymer (2) is, for example,
(A) Formula (I):

(Wherein R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and n represents a number of 1 to 30)
Monomer A1 represented by
Formula (II):

(Wherein R1, R2 and n represent the same meaning as defined in formula (I), m represents a number of 1 to 30, and the oxyethylene group and oxypropylene group in [] are blocked or randomly added. And any one of the monomer A2 and the formula (III):

(Wherein R1, R2 and n represent the same meaning as defined in formula (I))
5 to 45% by weight of at least one monomer selected from monomers A3 represented by:
(B) 3 to 40% by weight of a monomer having a salt-forming group;
(C) 5 to 40% by weight of a macromonomer having a number average molecular weight of 500 to 500,000,
(D) A vinyl polymer obtained by polymerizing 0 to 87% by weight of a monomer copolymerizable with the monomers (A), (B), and (C).

  Specific examples of the monomer A1 include polypropylene glycol mono (meth) acrylate and the like, and these can be used alone or in admixture of two or more. Specific examples of the monomer A2 include, for example, ethylene glycol / propylene glycol (meth) acrylate, poly (ethylene glycol / propylene glycol) mono (meth) acrylate, and the like. These may be used alone or in combination of two or more. Can be mixed and used. Examples of commercially available monomers A1 or A2 include Blemmer PP-1000, PP-500, PP-800, AP-150, AP-400, AP-550, AP-800 manufactured by NOF Corporation. , 50PEP-300, 70PEP-350B, AEP series, 30PPT-800, 50PPT-800, 70PPT-800, APT series, 10PPB-500B, 10APB-500B, 50POEP-800B, 50AOEP-800B, ASEP series, PNEP series, PNPE Series, 43ANEP-500, 70ANEP-550 and the like.

  Specific examples of the monomer A3 include polyethylene glycol mono (meth) acrylate. Specific examples of the commercially available monomer A3 include NK esters M-20G and 40G manufactured by Shin-Nakamura Kagaku Co., Ltd. , 90G, 230G, Blemmer PE series of Nippon Oil & Fats Co., Ltd., PME-100, 200, 400, 1000, and the like. The content of the (meth) acrylic acid ester monomer A in the vinyl polymer is 5 to 45% by weight, preferably 5 to 35% by weight, from the viewpoint of printing density and ink viscosity.

  The salt-forming group-containing monomer (B) is preferably an anionic monomer or a cationic monomer. Anionic monomers and cationic monomers can be used alone or in admixture of two or more.

  Specific examples of the anionic monomer include an unsaturated carboxylic acid monomer, an unsaturated sulfonic acid monomer, and an unsaturated phosphoric acid monomer. Specific examples of the unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, and 2-methacryloyloxymethyl succinate. From the viewpoints of ink viscosity and dischargeability, unsaturated carboxylic acid monomers are preferred, and acrylic acid and methacrylic acid are more preferred.

  Examples of the cationic monomer include polyvinylamine, polyallylamine, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylamide and the like, and particularly N, N-dimethylaminoethyl acrylate and N, N -Dimethylaminopropylacrylamide is preferred. The content of the salt-forming group-containing monomer (B) is 3 to 40% by weight, preferably 5 to 30% by weight, from the viewpoints of dispersion stability and ejection stability.

  The macromonomer (C) preferably has a polymerizable functional group at one end, and the number average molecular weight is more preferably 1,000 to 10,000. Specific examples include a styrene macromer having a polymerizable functional group at one end, a styrene / acrylonitrile macromer having a polymerizable functional group at one end, and a styrene type having a polymerizable functional group at one end. Macromers are preferred.

  Examples of monomers other than styrene constituting the styrene macromonomer include acrylonitrile. Further, the content of styrene is preferably 60% by weight or more, more preferably 70% by weight or more, from the viewpoint that the pigment is sufficiently contained in the vinyl polymer.

  Among the styrenic macromers having a polymerizable functional group at one end, those having an acryloyloxy group or a methacryloyloxy group as a polymerizable functional group at one end are preferable. Examples of commercially available styrenic macromers include AS-6, AN-6, AN-6S, HS-6S, and HS-6 manufactured by Toa Gosei Co., Ltd. The content of the macromer (C) is preferably 0.1 to 40% by weight, more preferably 1 to 30% by weight, from the viewpoint of water resistance and scratch resistance.

  The monomer (D) is copolymerizable with the monomers (A), (B), and (C). Specific examples thereof include (meth) acrylic acid esters, aromatic ring-containing monomers, macromers. Can be mentioned. These can be used alone or in admixture of two or more. This monomer (D) preferably contains at least one selected from the group consisting of an aromatic ring-containing monomer and a macromer from the viewpoint of water resistance and scratch resistance.

  (Meth) acrylic acid esters include (meth) acrylic acid esters whose ester moiety is an alkyl group having 1 to 18 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meth) ) Acrylates. Examples of the aromatic ring-containing monomer include styrene, α-methylstyrene, vinyl toluene, and vinyl naphthalene from the viewpoint of water resistance.

  The amount of these monomers present in the vinyl monomer obtained by polymerizing the above monomers (A), (B), (C), and (D) is such that the monomer (A) is 5 to 45% by weight (preferably 10 to 10%). 35 wt%), monomer (B) is 3 to 40 wt% (preferably 5 to 35 wt%), monomer (C) is 5 to 40 wt% (preferably 10 to 35 wt%), and monomer (D) is It is 0 to 87% by weight (preferably 0 to 75% by weight). The weight average molecular weight of the vinyl polymer is preferably 3,000 to 300,000, more preferably 5,000 to 200,000, from the viewpoints of print density and ejection stability.

Specifically, the polymer particle dispersion containing the pigment used in the ink composition can be prepared by the method described in JP-A-2001-247810. For example, it can be preferably prepared by the following steps. That is,
(1) A step of preparing a solvent dispersion by mixing a polymer solution dissolved in a water-soluble organic solvent (for example, alcohols, ketones, ethers, etc.), a pigment, and, if necessary, a neutralizing agent;
(2) a transfer emulsification step of developing this dispersion into an aqueous phase to prepare an aqueous suspension;
(3) A step of distilling off the water-soluble organic solvent added at the time of preparing the solvent dispersion and including the pigment in polymer particles.

  The step of including the pigment in the polymer is performed using a disperser (for example, a ball mill, a sand mill, an attritor, a roll mill, an agitator mill, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a jet mill, an ang mill, preferably a high-pressure homogenizer). It can be carried out.

（式中、Ｒ１、Ｒ２、ｍ及びｎは前記と同じ意味であり、オキシプロピレン基及びオキシテトラメチレン基はブロック付加又はランダム付加している）
で表されるモノマーＡ４からなる群より選ばれた１種以上のモノマーと、
（３）前記塩生成基を有するモノマー（Ｂ）と、
（４）前記モノマーＡ３、前記モノマーＡ１、前記モノマーＡ２、又は前記モノマーＡ４と、前記モノマー（Ｂ）、及び前記モノマー（Ｃ）と共重合可能なモノマーと
を重合させてなるビニルポリマーであることもできる。 The polymer is
(1) the monomer A3;
(2) The monomer A1, the monomer A2, and the formula (IV):

(In the formula, R1, R2, m and n have the same meaning as described above, and the oxypropylene group and the oxytetramethylene group are block-added or randomly added)
One or more monomers selected from the group consisting of monomers A4 represented by:
(3) a monomer (B) having the salt-forming group;
(4) A vinyl polymer obtained by polymerizing the monomer A3, the monomer A1, the monomer A2, or the monomer A4 with the monomer (B) and a monomer copolymerizable with the monomer (C). You can also.

  This vinyl polymer is, for example, (1) 5-45% by weight of the monomer A3, (2) one or more monomers 5-45 selected from the group consisting of the monomer A1, the monomer A2, and the monomer A4. It can be obtained by copolymerizing a monomer composition containing 15% by weight, (3) monomer (B) 3 to 40% by weight, and (4) copolymerizable monomer (D) 15 to 87% by weight.

  Specific examples of the monomer A4 include propylene glycol / tetramethylene glycol mono (meth) acrylate, poly (propylene glycol / tetramethylene glycol) mono (meth) acrylate, propylene glycol / polybutylene glycol mono (meth) acrylate, and poly (propylene). Glycol / butylene glycol) mono (meth) acrylate and the like. These can be used alone or in admixture of two or more.

  An ink jet recording apparatus according to the present invention is an ink jet recording apparatus including a waste liquid tank that collects ink droplets ejected to a region other than a recording medium. The ink droplets ejected to the area other than the recording medium are, for example, waste ink due to flushing or cleaning, or waste ink due to borderless printing.

(Example)
EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.
[1] Preparation of color ink composition (1) Preparation of polymer (I) Monomers having the following compositions were prepared.
Polypropylene glycol monomethacrylate (n = 9) 15% by weight
(In the above formula (I), R1 is methyl and R2 is hydrogen. Trade name: Blemmer PP-500, manufactured by NOF Corporation)
Polyethylene glycol monomethacrylate (n = 23) 10% by weight
(In the above formula (IV), m = 23, a compound in which R1 and R2 are methyl. Trade name: NK ester M-230G, manufactured by Shin-Nakamura Chemical Co., Ltd. Methacrylic acid 14% by weight
Styrene monomer 36% by weight
15% by weight of styrene macromer
(Styrene-acrylonitrile copolymer macromer, styrene content: 75% by weight, number average molecular weight: 6000, functional group: methacryloyl group, trade name: AN-6, manufactured by Toagosei Co., Ltd.)
n-butyl methacrylate 10% by weight
A reaction vessel was charged with 20 parts by weight of methyl ethyl ketone, 0.03 part by weight of a polymerization chain transfer agent (2-mercaptan etarule), and 10% of the total amount of the above monomers, and mixed. Thereafter, the container was replaced with nitrogen gas. Meanwhile, the dropping device was filled with the remaining 90% of the monomer composition.

  Polymer chain transfer agent (2-mercaptan ethanol) 0.27 wt%, methyl ethyl ketone 60 wt%, and 2,2'-azobis (2,4-dimethylvaleronitrile) were then added to the dropping apparatus and mixed. Thereafter, the dropping device was replaced with nitrogen gas.

  The temperature of the mixture in the reaction vessel was raised to 65 ° C. with stirring in a nitrogen atmosphere, and the mixture in the dropping apparatus was dropped into the reaction vessel over 3 hours. Two hours after the completion of dropping at 65 ° C., a solution in which 0.3% by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in 5% by weight of methyl ethyl ketone was added. The mixture was aged at 65 ° C. for 2 hours and further at 70 ° C. for 2 hours to obtain a polymer solution.

  A portion of the polymer solution obtained as described above was isolated by drying under reduced pressure by removing the solvent.

  The weight average molecular weight was determined by gel permeation chromatography using polystyrene as a standard substance and chloroform containing dodecyldimethylamine at a concentration of 1 ml / l as a solvent. As a result, the weight average molecular weight was 70,000.

(2) Preparation of Pigment Dispersion (a) Preparation of Yellow Dispersion I A polymer particle dispersion containing a yellow pigment was produced as follows. That is, the polymer (I) produced above was dissolved in methyl ethyl ketone to form a 50% solution. I. Pigment Yellow 74 75 parts, 0.05% potassium hydroxide 300 parts, and methyl ethyl ketone 60 parts were mixed and stirred with a homogenizer for 30 minutes. Thereafter, 300 parts of ion-exchanged water was added and further stirred for 2 hours. A total amount of methyl ethyl ketone and a part of water were distilled off using a rotary evaporator, followed by filtration through a 0.3 μm membrane filter to obtain a yellow dispersion having a solid content of 20% by weight.

(B) Preparation of Magenta Dispersion I Polymer particle dispersion containing a magenta pigment was prepared as C.I. I. A magenta dispersion was obtained in the same manner as the yellow dispersion except that 80 parts of Pigment Violet 1980 and 40 parts of a 50% solution of polymer (I) in methylethylkenton were used.

(C) Preparation of Cyan Dispersion I Polymer particle dispersion containing a cyan pigment was prepared as C.I. I. A cyan dispersion was obtained in the same manner as the yellow dispersion except that 50 parts of CI Pigment Blue 15: 4 and 100 parts of a 50% methylethylkenton solution of polymer (I) were used.

[2] Preparation of Color Ink Composition According to the composition shown in Table 1 below, the above yellow dispersion I, magenta dispersion I, or cyan dispersion I was mixed with solvents and ultrapure water, Stir for 2 hours. Subsequently, a color ink composition was prepared by filtering using a membrane filter (trade name; manufactured by Nihon Millipore Limited) having a pore diameter of about 1.2 μm. In Table 1, the added amount of each composition is% by weight.

(In Table 1, Surfinol 465 and Surfinol TG are trade names; manufactured by Air Products)

[3] Preparation of Ink Set The yellow, magenta, and cyan inks obtained in the preceding paragraphs [1] to [2] were combined as shown in Table 2 to obtain an ink set.

(1) Preparation of reactant A A 12 L flask equipped with a mechanical stirrer, thermometer, N2 inlet, drying tube outlet, and addition funnel was charged with 4002 g of tetrahydrofuran (THF) and 7.7 g of p-xylene. Next, 2.0 mL of a 1.0 M acetonitrile solution of tetrabutylammonium m-chlorobenzoate was added as a catalyst. As an initiator, 155.1 g (0.891 M) of 1-methoxy-1-trimethylsiloxy-2-methylpropene was injected. Supply of 2801 g (17.8 M) of 2-dimethylaminoethyl methacrylate was started and supplied over 45 minutes. 100 minutes after the completion of the supply (more than 99% of the monomers had reacted), the supply of 2045 g (14.4M) of butyl methacrylate was started, and the supply was performed over 30 minutes. When 400 minutes had elapsed, 310 g of dry methanol was added to the solution, and distillation was started. 1725 g (total) of solvent was removed. After the distillation was completed, 1783 g of isopropanol was added. Thus, a butyl methacrylate / dimethylaminoethyl methacrylate (20/20) diblock polymer (solid content = 49.6%) was produced. The polymer was then neutralized with 2052 g (17.8 M) of concentrated phosphoric acid and converted to water to produce a 15% solution of a polymeric salt reactant A.

(2) Preparation of emulsion 233 g of water, 25 g of n-butyl methacrylate, and 25 g of the reaction product A were refluxed inside the reactor. When refluxed, 27.5 g of water and 0.68 g of VA-044 (manufactured by Wako Pure Chemical Industries) were added. In a separate flask, 561 g of water, 225 g of n-butyl methacrylate, and 142 g of reactant A were mixed well using an Eppenbach homogenizer. The mixture was then added to the reaction flask over 100 minutes. When the addition of the mixture was complete, the contents of the reaction flask were refluxed for an additional 60 minutes, then a mixture of water (12.5 g) and VA-044 (0.68 g) was added to the reaction flask. The contents of the reaction flask were refluxed for an additional 60 minutes and then cooled to room temperature to give an emulsion. The solid content of the obtained emulsion was 23%. An emulsion A was thus obtained.

  Emulsion A 30% prepared above, glycerin 54%, triethylene glycol monobutyl ether 10%, 1,2-hexanediol 5%, 1,2-benzisothiazolin-3-one (Proxel XL2; manufactured by Arch Chemicals Inc.) 0 1% and 0.9% triethanolamine were mixed to prepare an impregnating solution A.

(1) Preparation of Reactant B A 12 L flask equipped with a stirrer, thermometer, N2 inlet, drying tube outlet, and addition funnel was charged with 3027 g of tetrahydrofuran (THF) and 6.2 g of p-xylene. Next, 2.5 mL of a 1.0 M acetonitrile solution of tetrabutylammonium m-chlorobenzoate was added as a catalyst. As an initiator, 234.4 g of 1,1-bis (trimethylsiloxy) -2-methylpropene was injected. The feeding of 2.5 mL of 1.0 M acetonitrile solution of tetrabutylammonium m-chlorobenzoate was started and the whole amount was added over 150 minutes. Subsequently, the feeding of 1580 g of trimethylsilyl methacrylate was started, and the whole amount was added over 30 minutes. 120 minutes after the completion of the supply, 1425 g of butyl methacrylate and 503 g of methyl methacrylate were started, and the whole amount was added over 30 minutes. At the end of 320 minutes, 650 g of dry methanol was added to the solution and distillation was started. During the first stage distillation, 1250.0 g of material was removed from the flask. 1182 g of isopropanol was added. Distillation was continued and a total of 2792 g of solvent was removed.

  This produced a butyl methacrylate / methyl methacrylate // methacrylic acid AB block polymer (10/5 // 10) having a number average molecular weight (Mn) of 2900 and a solid content of 50.5%. 396 g of this polymer, 68 g of 2-amino-2-methyl-1-propanol (AMP), and 1536 g of deionized water were mixed together to form an aqueous solution of reaction B.

(2) Preparation of emulsion 637 g of methyl methacrylate and 63 g of n-butyl methacrylate were added to 700 g of the reaction product B prepared in the preceding item (1) and 315 g of deionized water in a high-speed stirrer (homogenizer). Prepared. Stirring was continued for approximately 30 minutes until a pre-emulsified mixture with a solid content of 45% by weight was formed. Laboratory scale polymerization was performed in a resin kettle equipped with a dropping funnel containing the emulsified mixture, an air stirrer, a nitrogen inlet, and a heating mantle. An amount of deionized water was added to the kettle so that the final product had a solids content of 25%. The air inside the kettle was replaced with nitrogen, and water was heated to 70 to 72 ° C. Then one-tenth of the pre-emulsified mixture and a 6.5% by weight aqueous solution of 2% aqueous solution of sodium bisulfite and 0.25% (based on the weight of monomers used in the emulsified mixture) of ammonium persulfate. Was added to a resin pot. The temperature was raised to 80 ° C. and this temperature was maintained throughout the polymerization. The remaining emulsified mixture and sodium bisulfite solution were added over 75 minutes. The total amount of sulfite added was 0.14% based on the monomer concentration. A double volume of aqueous ammonium persulfate solution was prepared and added in three portions. The first was done at a point in time between the emulsified mixture and sodium sulfite addition, the second was done when the addition of these materials was finished, and the third was done 15 minutes later. The resulting latex was held at 80-85 ° C. for 120 minutes, then cooled and filtered. Thus, emulsion B was obtained.

  Emulsion B 15% prepared above, glycerin 50%, polyethylene glycol # 400 30%, 1,2-hexanediol 4%, 1,2-benzisothiazolin-3-one (Proxel XL2; manufactured by Arch Chemicals Inc.) 0 .3% and triethanolamine 0.7% were mixed to make impregnation liquid B.

  An impregnating solution C was prepared by mixing 10% of a styrene acrylic copolymer resin (John Crill 631; manufactured by Johnson Polymer Co., Ltd.), 1% of tripropanolamine and 89% of water as a poorly water-soluble resin.

  Styrene acrylic copolymer resin (John Cryl 790; manufactured by Johnson Polymer Co., Ltd.) 10%, potassium hydroxide 0.1%, 1,2-benzisothiazolin-3-one (Proxel XL2; Arch Chemicals Inc.) as a poorly water-soluble resin. (Product made) 0.1% and water 89.8% were mixed to make impregnating solution D.

<Example of physical property evaluation>
(1) Waste ink liquid absorbers A and B
A cleaning process was performed using a waste ink liquid absorber that does not include the waste ink liquid absorber protrusion and a waste ink liquid absorber that includes the waste ink liquid protrusion. Specifically, a waste ink liquid absorber (hereinafter, referred to as a waste ink liquid absorber A) having the form shown in FIGS. 4 and 5 and a waste ink liquid absorber having protrusions shown in FIGS. 6 and 7. (Hereinafter referred to as waste ink liquid absorber B) was used.

(2) Impregnation liquid The mixed liquids prepared in Examples 1 to 4 were used by uniformly impregnating the waste ink liquid absorbers A and B at an impregnation amount of 5 g / g.

  In Comparative Example 1, the waste ink liquid absorber A not impregnated with the permeable component was used, and in Comparative Example 2, the waste ink liquid absorber A impregnated with pure water was used.

(3) Waste liquid cleaning treatment An ink cartridge in which the waste ink liquid absorbers A and B are mounted on an ink jet printer [PX-V700 (trade name): manufactured by Seiko Epson Corporation] and filled with the ink set 1 or 2 described above. Was attached to the color row. As the black ink row, a standard ink cartridge of PX-V700 was used as it was. Waste liquid cleaning was repeated every 6 hours in an environment of 40 ° C. and 20% relative humidity, and the number of times until the waste liquid was deposited and the waste liquid tube was clogged was measured. Table 3 shows the results of evaluation based on the following four criteria.
Judgment AA: Even if waste liquid cleaning is performed 41 times or more, the waste liquid tube does not clog.
A: The number of cleaning times until the waste liquid tube is clogged is 31 to 40 times. B: The number of cleaning times until the waste liquid tube is clogged is 21 to 30 times. C: The waste liquid tube is clogged by 20 times or less of waste liquid cleaning.

  Since the waste ink liquid absorber according to the present invention can easily absorb the waste ink liquid even when the waste ink discharged from the waste liquid tube has a property of foaming, the flushing and cleaning or borderless printing is performed. It can be effectively used for an ink jet recording apparatus.

FIG. 5 is a perspective view showing a state where an absorber filled in an absorber holding chamber is removed from a waste ink tank having a waste ink diffusion chamber and an absorber holding chamber. It is a perspective view which shows the state which filled the absorber holding chamber of the waste ink tank of FIG. 1 with the absorber. It is a perspective view which shows the other example of a waste liquid tank. FIG. 3 is a perspective view of a waste ink tank having a waste ink diffusion chamber surrounded by a bottom surface of the waste ink tank, a top surface and four side surfaces of the waste ink liquid absorber. FIG. 5 is a cross-sectional view of the waste ink tank of FIG. 4. It is a fragmentary perspective view of the waste ink tank containing the waste ink liquid absorber which has a waste ink liquid absorber protrusion part. It is a fragmentary sectional view of the waste ink tank of FIG. FIG. 3 is a partial perspective view of an ink jet recording apparatus including a waste liquid tank for waste ink.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Inkjet recording apparatus; 11 ... Recording object;
15 ... Waste liquid tank; 22 ... Discharge tube;
22a ... annular discharge port; 31 ... collection container;
31a ... right side of the collection container; 31b ... insertion hole;
32 ... Waste ink liquid absorber; 34 ... Recess;
35 ... Waste ink diffusion chamber; 35a ... Upper surface of waste ink diffusion chamber;
35b: lower surface of the waste ink diffusion chamber; 38 ... waste ink liquid absorber protrusion;
40: printing unit; 42 ... carriage; 44 ... recording head;
46 ... shaft hole; 48 ... guide shaft; 52 ... discharge roller;
402 ... Timing belt; 404 ... Carriage motor;
406 ... Black ink cartridge; 408 ... Color ink cartridge;
70: Waste liquid transport unit; 72 ... Capping means;
74 ... connecting tube; 76 ... pump; 80 ... wiping means;
100 ... Waste liquid tank; 102 ... Waste liquid tank body;
104 ... Waste ink diffusion chamber; 106 ... Absorber holding chamber;
146 ... Absorber; 180 ... Waste liquid tank;
184 ... Waste ink diffusion chamber; 186, 186a, b, c ... Absorber;
188, 188a, b, c... Ink waste liquid subchannel.

Claims (17)

  A waste ink liquid absorber for a waste ink tank of an ink jet recording apparatus, comprising an impregnating liquid containing at least a poorly water-soluble resin in a part including at least a contact surface with the waste ink liquid. Ink liquid absorber.   Monomer selected from the group consisting of the above-mentioned poorly water-soluble resin from acrylic monomers, methacrylic monomers, vinyl monomers, maleic acid, maleic anhydride, styrene, itaconic acid, N-vinylpyrrolidone, acrylamide, methacrylamide, and derivatives thereof. The waste ink liquid absorber according to claim 1, comprising a poorly water-soluble resin obtained by polymerizing the water.   The methacrylic monomer is methyl methacrylate (MMA), ethyl methacrylate, (EMA), propyl methacrylate, n-butyl methacrylate, (BMA or NBMA), hexyl methacrylate, 2-ethylhexyl methacrylate (EHMA), Octyl methacrylate, lauryl methacrylate (LMA), stearyl methacrylate, phenyl methacrylate, hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate, ethoxytriethylene glycol methacrylate (ETEGMA), 2-ethoxyethyl methacrylate, methacrylo Nitrile, 2-trimethylsiloxyethyl methacrylate, glycidyl methacrylate (GMA), p-tolyl methacrylate, methacrylic acid (MMA), diethylamino methacrylate Le (DMAEMA), diethylaminoethyl methacrylate, t- butyl aminoethyl methacrylate, and a monomer selected from the group consisting of methacrylic acid sorbyl, waste ink absorbing body according to claim 2.   The acrylic monomer is methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, phenyl acrylate, acrylic acid From the group consisting of hydroxyethyl, hydroxypropyl acrylate, acrylonitrile, 2-trimethylsiloxyethyl acrylate, glycidyl acrylate, p-tolyl acrylate, sorbyl acrylate, acrylic acid, dimethylaminoethyl acrylate, and diethylaminoethyl acrylate The waste ink absorber according to claim 2, which is a selected monomer.   The waste ink absorber according to any one of claims 1 to 4, further comprising a water-soluble solvent.   The waste ink liquid absorber according to any one of claims 1 to 5, wherein at least one of the water-soluble solvents has a vapor pressure at 20 ° C of 0.01 mmHg or less.   7. The absorber holding chamber of a waste ink tank having a waste ink diffusion chamber not filled with a waste ink liquid absorber and an absorber holding chamber filled with a waste ink liquid absorber is filled. The waste ink liquid absorber described in 1.   The waste ink liquid absorber according to any one of claims 1 to 7, which comprises a nonwoven fabric or a foam.   The waste ink liquid absorber according to claim 8, wherein the non-woven fabric includes regenerated cellulose-based fibers and / or polyacrylic fibers.   The waste ink liquid absorber according to claim 8 or 9, comprising a saturated polyester film layer on at least a part of the surface.   There is a waste ink liquid absorber protrusion that extends from the surface of the waste ink liquid absorber in contact with the waste ink diffusion chamber so as to protrude in the direction of the interior of the waste ink diffusion chamber, and at least the impregnation of the waste ink liquid absorber protrusion The waste ink liquid absorber according to any one of claims 7 to 10, comprising a liquid.   The waste ink liquid absorber according to claim 11, wherein the protruding portion of the waste ink liquid absorber is made of polyurethane foam.   The waste ink liquid absorber according to any one of claims 7 to 12, wherein the waste ink diffusion chamber is surrounded by a bottom surface of a waste ink tank, an upper surface and four side surfaces of the waste ink liquid absorber.   Waste ink includes a pigment and the pigment, and the pigment can be dispersed in the ink composition, has a hydrophobic group and a hydrophilic group, and is not substantially dissolved in the ink composition. The waste ink liquid absorber according to any one of claims 1 to 13, which is an ink composition containing at least a polymer and water as a main solvent. The polymer is
(A) Formula (I):

(Wherein R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and n represents a number of 1 to 30)
Monomer A1 represented by
Formula (II):

(Wherein R1, R2 and n represent the same meaning as defined in formula (I), m represents a number of 1 to 30, and the oxyethylene group and oxypropylene group in [] are blocked or randomly added. And any one of the monomer A2 and the formula (III):

(Wherein R1, R2 and n represent the same meaning as defined in formula (I))
5 to 45% by weight of at least one monomer selected from monomers A3 represented by:
(B) 3 to 40% by weight of a monomer having a salt-forming group;
(C) 5 to 40% by weight of a macromonomer having a number average molecular weight of 500 to 500,000,
(D) The waste ink liquid absorber according to claim 14, which is a vinyl polymer obtained by polymerizing 0 to 87% by weight of a monomer copolymerizable with the monomers (A), (B), and (C). . The polymer is
(1) the monomer A3;
(2) The monomer A1, the monomer A2, and the formula (IV):

(In the formula, R1, R2, m and n have the same meaning as described above, and the oxypropylene group and the oxytetramethylene group are block-added or randomly added)
One or more monomers selected from the group consisting of monomers A4 represented by:
(3) a monomer (B) having the salt-forming group;
(4) A vinyl polymer obtained by polymerizing the monomer A3, the monomer A1, the monomer A2, or the monomer A4, the monomer (B), and a monomer copolymerizable with the monomer (C). The waste ink liquid absorber according to claim 14.   An ink jet recording apparatus comprising the waste ink liquid absorber according to any one of claims 1 to 16.

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