JP2007210121A - Liquid collecting container, liquid droplet discharge device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a mechanism for preventing mist in a container for storing a liquid from getting out of the container through an opening section may become complicated. <P>SOLUTION: This liquid collecting container is equipped with a container body 101 forming a storing section for storing liquid droplets delivered from a recording head 34 in the idling and a lid member 102 which is adapted to cover the container body 101 and forms thereon opening sections 89 for passing the liquid droplets therethrough. In the inner face side (the side of the container body) of the lid member 102, one of the opening sections 89 has ribs 111 and 111 falling toward the side of the liquid storing section of the container body 101 at both sides of the opening section 89 (both sides in the main scanning direction) and each of the other opening sections 89 has ribs 111 and 112 falling toward the side of the liquid storing section of the container body 101 at both sides of the opening section 89 (both sides in the main scanning direction). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid recovery container, a device for discharging droplets, and an image forming apparatus.

  In general, as an image forming apparatus combining a printer / fax / copier or a combination of these functions, an image forming unit employing an electrophotographic method is known. For example, a recording liquid (liquid) droplet is ejected. Recording medium (hereinafter also referred to as “paper”, but the material is not limited, and a recording medium, a transfer material, recording paper, etc. are also used synonymously). Inkjet image forming unit is mounted for image formation (recording, printing, printing, and printing are also used synonymously) by adhering a recording liquid (hereinafter also referred to as ink) to paper while conveying There are also things.

  In an image forming apparatus that forms an image with an apparatus for discharging such droplets, a function for maintaining and recovering the performance of a recording head that discharges a recording liquid is indispensable. In order to deal with the case where the recording liquid may thicken in the nozzle (ejection port) due to printing in a high temperature, low humidity environment, or low frequency printing, the nozzle may be clogged regularly. By discharging droplets that do not contribute to recording (image formation) (droplets that become waste liquid), an idle discharge operation is performed to discharge the thickened recording liquid.

As described in Japanese Patent Application Laid-Open No. 2004-228688, the recovery of the liquid droplets as the waste liquid is provided with a recovery unit (empty discharge receptacle) for recovering the recording liquid.
JP 2005-144940 A

In this case, various proposals have been made to prevent the collected recording liquid from coming out again. For example, according to Patent Document 2, it is possible to divide the storage location according to the state of the discharged ink, and Patent Document 3 provides a taper on the storage portion side so that the discharged ink is guided into the storage portion. Providing a simple guide member.
JP 2005-246698 A JP 2001-030518 A JP 2004-042444 A

Further, Patent Documents 5 and 6 disclose devices that are in a positional relationship such that they face each other only when the ink recovery unit rotates and ink is ejected from the recording head, and Patent Documents 7 and 8 control the flow of airflow. However, Patent Document 9 describes that a fan is provided.
JP 2005-219256 A JP 2001-162836 A JP 2003-072111 A JP 2000-015834 A Japanese Patent No. 3520825

Further, Patent Document 10 describes that a guiding means for guiding the ejected ink droplets into the ink collection and storage unit is provided, and Patent Document 11 describes that a means for sucking air is provided.
JP 2002-086759 A JP 2002-307725 A

  However, as described in Patent Documents 2 to 4, 10, a container having a shape characteristic on the container body side (the case side of the recovery unit) has a complicated shape, and the gold There is a problem that mold production becomes difficult and cost increases.

  In addition, as described in Patent Documents 4 to 9 and 11, the configuration of the recovery unit that merely recovers the liquid that becomes the waste liquid in the configuration in which the means for generating the airflow is provided or the recovery unit is rotated. As a result, there is a problem that the structure becomes complicated and the quality becomes excessive as well as the cost becomes high.

  The present invention has been made in view of the above problems, and provides a liquid recovery container in which liquid recovered with a simple configuration does not escape to the outside, an apparatus for ejecting liquid droplets including the liquid recovery container, and an image forming apparatus. For the purpose.

  In order to solve the above-described problems, a liquid recovery container according to the present invention includes at least a container main body that stores a liquid as a waste liquid, and a lid member that covers the container main body and has an opening through which liquid droplets pass. The lid member has ribs that fall on both sides of the opening portion toward the liquid storage portion side of the container body. In the present invention, “liquid that becomes waste liquid” means not only liquid that is discarded as it is, but also liquid that is to be reused.

  Here, the height of the rib is preferably 5 mm or more. The rib is preferably provided in parallel with the opening. Further, the rib is preferably separated from the periphery of the opening by a predetermined distance. In this case, the rib is preferably separated from the periphery of the opening by 1 mm or more. Moreover, it can be set as the structure which has several rib from which height differs. Moreover, it is preferable that the rib has a length of at least 2/3 or more of the longitudinal length of the opening.

  An apparatus for discharging droplets according to the present invention and an image forming apparatus according to the present invention include the liquid recovery container according to the present invention.

  According to the liquid recovery container of the present invention, the lid member has ribs that fall on both sides of the opening portion toward the liquid storage portion side of the container body. Before the ejected liquid droplets are ejected from the opening, the liquid droplets adhere to the ribs, and the liquid recovered with a simple configuration can be prevented from ejecting.

  According to the apparatus for ejecting droplets according to the present invention and the image forming apparatus according to the present invention, since the liquid recovery container according to the present invention is provided, scattering of the recovered liquid can be prevented.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective explanatory view of an ink jet recording apparatus as an image forming apparatus according to the present invention including a device for discharging droplets according to the present invention as viewed from the front side.
The ink jet recording apparatus includes an apparatus main body 1, a paper feed tray 2 for loading paper loaded in the apparatus main body 1, and a paper on which an image is recorded (formed) detachably mounted on the apparatus main body 1. A paper discharge tray 3 for stocking is provided. Furthermore, a cartridge loading for loading an ink cartridge that protrudes from the front surface to the front side of the apparatus main body 1 and is lower than the upper surface is provided at one end side of the front surface of the apparatus main body 1 (side of the paper supply / discharge tray section). The cartridge loading unit 4 has an operation / display unit 5 provided with operation buttons and a display.

  The cartridge loading unit 4 contains a plurality of recording liquids (inks) that are different color materials, such as black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. Ink cartridges 10k, 10c, 10m, and 10y (which are referred to as “ink cartridge 10” when colors are not distinguished) are inserted from the front side of the apparatus main body 1 toward the rear side and can be loaded. A front cover (cartridge cover) 6 that is opened when the ink cartridge 10 is attached or detached is provided on the front side of the cartridge loading unit 4 so as to be openable and closable.

Next, the mechanism part of the ink jet recording apparatus will be described with reference to FIGS. 2 is a schematic side view illustrating the outline of the mechanism, and FIG. 3 is an explanatory plan view of the main part.
A carriage 33 is slidably held in the main scanning direction by a guide rod 31 and a stay 32, which are guide members horizontally mounted on the left and right side plates 21A and 21B, and is shown in FIG. 3 via a timing belt by a main scanning motor (not shown). Move and scan in the direction of the arrow (carriage main scanning direction).

  The carriage 33 is provided with recording heads 34a and 34b composed of liquid ejection heads for ejecting ink droplets of yellow (Y), cyan (C), magenta (M), and black (K). The “recording head 34” is arranged in a sub-scanning direction orthogonal to the main scanning direction, and the ink droplet ejection direction is directed downward.

  Each of the recording heads 34 has two nozzle rows. One nozzle row of the recording head 34a has black (K) droplets, the other nozzle row has cyan (C) droplets, and the recording head 34b has one nozzle row. One nozzle row ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets.

  As an inkjet head constituting the recording head 34, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. It is possible to use a shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like provided as pressure generating means for generating a pressure for discharging a droplet.

  Further, the carriage 33 is equipped with head tanks 35a and 35b (referred to as “head tank 35” when not distinguished) for supplying ink of each color corresponding to the nozzle rows of the recording head 34. As described above, the sub tank 35 is supplied with ink of each color from the ink cartridge 10 of each color mounted in the cartridge loading unit 4 via the ink supply tube 36 of each color. The cartridge loading 4 is provided with a supply pump unit 24 for feeding ink in the ink cartridge 10.

  On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (pressure plate) 41 of the paper feeding tray 2, a half-moon roller (feeding) that separates and feeds the papers 42 one by one from the paper stacking unit 41. A separation pad 44 made of a material having a large friction coefficient is provided facing the paper roller 43) and the paper feed roller 43, and the separation pad 44 is urged toward the paper feed roller 43 side.

  In order to feed the paper 42 fed from the paper feeding unit to the lower side of the recording head 34, a guide member 45 for guiding the paper 42, a counter roller 46, a transport guide member 47, and a tip pressure roller. And a holding belt 48 which is a conveying means for electrostatically attracting the fed paper 42 and conveying it at a position facing the recording head 34.

  The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction). Further, a charging roller 56 that is a charging unit for charging the surface of the transport belt 51 is provided. The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51. The transport belt 51 rotates in the belt transport direction of FIG. 3 when the transport roller 52 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 61 for separating the paper 42 from the conveying belt 51, a paper discharge roller 62, and a paper discharge roller 63 are provided. The paper discharge tray 3 is provided below the paper discharge roller 62.

  A duplex unit 71 is detachably mounted on the back surface of the apparatus body 1. The duplex unit 71 takes in the paper 42 returned by the reverse rotation of the conveyance belt 51, reverses it, and feeds it again between the counter roller 46 and the conveyance belt 51. The upper surface of the duplex unit 71 is a manual feed tray 72.

  Further, as shown in FIG. 3, a maintenance / recovery mechanism 81 including a recovery means for maintaining and recovering the state of the nozzles of the recording head 34 is arranged in the non-printing area on one side of the carriage 33 in the scanning direction. Yes.

  The maintenance / recovery mechanism 81 includes cap members (hereinafter referred to as “caps”) 82a and 82b (hereinafter referred to as “caps 82” when not distinguished from each other) for capping the nozzle surfaces of the recording head 34, and nozzle surfaces. A wiper blade 83 that is a blade member for wiping the ink, and an empty discharge receiver 84 that receives liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid. ing.

  Further, as shown in FIG. 3, in the non-printing area on the other side in the scanning direction of the carriage 33, idle discharge is performed to discharge liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An ink recovery unit (empty discharge receiver) 88, which is a liquid recovery container according to the present invention for receiving liquid droplets at the time, is disposed. I have.

  In the ink jet recording apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feeding tray 2, and the sheet 42 fed substantially vertically upward is guided by the guide 45, and the transport belt 51 and the counter roller 46, and the leading end is guided by the conveying guide 37 and pressed against the conveying belt 51 by the tip pressing roller 49, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately repeated with respect to the charging roller 56, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 51 alternates, that is, in a sub-scanning direction that is a circumferential direction. , Plus and minus are alternately charged in a band shape with a predetermined width. When the paper 42 is fed onto the conveyance belt 51 charged alternately with plus and minus, the paper 42 is attracted to the conveyance belt 51, and the paper 42 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 51.

  Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped paper 42 to record one line, and after the paper 42 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.

  Further, during printing (recording) standby, the carriage 33 is moved to the maintenance / recovery mechanism 81 side, and the recording head 34 is capped by the cap 82 to keep the nozzles in a wet state, thereby preventing ejection failure due to ink drying. . Further, the recording liquid is sucked from the nozzle by a suction pump (not shown) with the recording head 34 capped by the cap 82 (referred to as “nozzle suction” or “head suction”), and the thickened recording liquid and bubbles are discharged. Perform recovery action. In addition, before the start of recording, in the middle of recording, etc., an empty ejection operation is performed to eject ink (liquid droplets that become waste liquid) that is not related to recording toward the recovery unit 88 or the like. As a result, the stable ejection performance of the recording head 34 is maintained.

  A liquid recovery container (here, an ink recovery unit) in this image forming apparatus will be described with reference to FIGS. 4 is a perspective explanatory view of the recovery unit, FIG. 5 is a perspective explanatory view of the inside of the lid member of the recovery unit, FIG. 6 is a perspective explanatory view of the outside of the cover member, and FIG. FIG. 8 is a schematic explanatory view for explaining the operation of the recovery unit.

  The ink recovery unit 88 includes a container main body 101 that forms a container that stores liquid droplets ejected from the recording head 34, and a lid that covers the container main body 101 and has an opening 89 through which liquid droplets pass. Member 102. The container main body 101 has a scraping mechanism for scraping off the liquid adhering to the wall surface. The scraping mechanism is driven by a drive lever 103 that is moved by the movement of the recording head 34, and the lid member 102 is driven by this driving mechanism. It also has a function of preventing the spring 104 from falling off to return the lever 103 to the initial position.

  Here, on the inner surface side (container main body side) of the lid member 102, ribs 111 and 111 are provided on both sides (both sides in the main scanning direction) of one opening 89 so as to fall toward the liquid storage portion side of the container main body 101. In addition, ribs 111 and 112 are provided on both sides of the other opening 89 (both sides in the main scanning direction) to fall toward the liquid storage portion of the container main body 101. The ribs 111 and 112 are integrally formed with the lid member 102, but may be fixed separately.

  With this configuration, as shown in FIG. 8, when the droplet 100 that does not contribute to image formation (becomes waste) is ejected from the recording head 34 in order to perform an idle ejection operation or the like, the lid of the recovery unit 88 is covered. The landing position is guaranteed up to the opening 89 of the member 102, but the droplet 100 becomes a mist inside the container body 101 and spreads like a Chinese numeral “eight”.

  When the droplets become mist in this way, the weight per droplet becomes very light, so that a flow in which the air in the container main body 101 moves outward from the opening 89 occurs as the recording head 34 moves. Then, the mist droplets jump out of the opening 89 of the lid member 102, float in the apparatus, and adhere to the paper and each part of the apparatus.

  Therefore, the recovery unit 88 is provided with ribs 111 and 112 inside the lid member 102 toward the container main body 101 side. As a result, the ribs 111 and 112 adhere to the droplets that have become mist in the container main body 101 before the droplets are ejected from the opening 89, so that the ejection of the droplets from the recovery unit 88 can be reduced or suppressed. . In other words, the rib of the lid member plays a function of collecting when the droplet mist in the container body jumps out of the opening, and it is possible to reduce and suppress droplet ejection simply by providing the rib. Configuration is also simplified.

  Here, the ribs 111 and 112 provided on the lid member 102 preferably have a height H (see FIG. 7) of 5 mm or more. If the height of the ribs 111 and 112 is too low, the droplet mist moving toward the opening 89 may not be efficiently attached.

  The ribs 111 and 112 are provided in parallel with the opening 89. That is, in this example, the recording head 34 is provided in a direction (paper feeding direction) orthogonal to the moving direction of the recording head 34. When the recording head 34 moves in the direction indicated by the arrow in FIG. 8, the flow of air sucked out from the container main body 101 is also the same as the moving direction of the head. Thus, the droplet mist can be reliably collected.

  Further, the ribs 111 and 112 are provided at positions separated from the periphery of the opening 89 by a predetermined distance D (see FIG. 7). If the ribs 111 and 112 are too close to the periphery of the opening 89, the liquid droplets ejected from the recording head 34 tend to adhere to the ribs 111 and 112 when entering the opening 89, and the liquid recovery is uncertain. There is a risk. The predetermined distance D is preferably 1 mm or more according to experiments.

  Further, by having a plurality of ribs having different heights (heights H1 and H2 in FIG. 7) such as the ribs 111 and 112, ribs having appropriate heights can be individually provided according to the characteristics of the liquid and the position of the recording head. Can be set manually.

  The ribs 111 and 112 preferably have a length L1 (see FIG. 5) that is at least 2/3 of the longitudinal length L2 of the opening 89 (see FIG. 6). If the length of the rib relative to the length of the opening is too short, the droplet mist may not be sufficiently adhered.

Next, an example of a recording liquid (here, ink) as a liquid will be described.
As the color material of the ink used by the image forming apparatus, either a pigment or a dye can be used, or a mixture can be used.

[Pigment]
As the pigment, those listed below are preferably used. Moreover, you may use these pigments in mixture of multiple types.

  Examples of organic pigments include azo, phthalocyanine, anthraquinone, quinacridone, dioxazine, indigo, thioindigo, perylene, isoindolenone, aniline black, azomethine, rhodamine B lake pigment, and carbon black. It is done.

  Examples of inorganic pigments include iron oxide, titanium oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, bitumen, cadmium red, chrome yellow, and metal powder.

  The particle diameter of these pigments is preferably 0.01 to 0.30 [mu] m. If the particle diameter is 0.01 [mu] m or less, the light resistance and feathering are deteriorated because the particle diameter approaches that of the dye. On the other hand, if it is 0.30 μm or more, clogging of the discharge port or clogging with a filter in the printer occurs, and the discharge stability cannot be obtained.

  The carbon black used in the black pigment ink is carbon black produced by the furnace method and the channel method, the primary particle size is 15 to 40 millimicrons, the specific surface area by the BET method is 50 to 300 square meters / g, The DBP oil absorption is preferably 40 to 150 ml / 100 g, the volatile content is 0.5 to 10%, and the pH value is 2 to 9. As such a thing, for example, no. 2300, no. 900, MCF-88, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, no. 2200B (Mitsubishi Chemical Corporation), Raven700, 5750, 5250, 5000, 3500, 1255 (Columbia), Regal400R, 330R, 660R, MoguL, Monarch700, 800, 880, 900, 1000, 1100, 1300, Monarch 1400 (manufactured by Cabot), color black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, U, the same V, the same 140U, the same 140V, the special black 6, the same 5, the same 4A, the same 4 (manufactured by Degussa) and the like can be used, but are not limited thereto.

Specific examples of color pigments are listed below.
Examples of organic pigments include azo, phthalocyanine, anthraquinone, quinacridone, dioxazine, indigo, thioindigo, perylene, isoindolenone, aniline black, azomethine, rhodamine B lake pigment, and carbon black. Examples of inorganic pigments include iron oxide, titanium oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, bitumen, cadmium red, chrome yellow, and metal powder.

Specific examples according to color are as follows.
Examples of pigments that can be used for yellow ink include C.I. I. Pigment Yellow 1, 2, 2, 3, 12, 14, 16, 17, 17, 73, 74, 75, 83, 93, 95, 97, 98, 114, 128, 129, 151, 154, etc., but are not limited thereto.

  Examples of pigments that can be used in magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 123, 168, 184, 202, etc. However, it is not limited to these.

  Examples of pigments that can be used for cyan ink include C.I. I. Pigment blue 1, 2, 3, 15: 3, 15:34, 16, 22, 22, 60, C.I. I. Examples thereof include, but are not limited to, Bat Blue 4 and 60.

  Moreover, the pigment contained in each ink to be used can be newly manufactured.

  The pigments listed above can be made into an inkjet recording liquid by dispersing them in an aqueous medium using a polymer dispersant or a surfactant. As a dispersant for dispersing such organic pigment powder, a normal water-soluble resin or a water-soluble surfactant can be used.

  Specific examples of water-soluble resins include styrene, styrene derivatives, vinyl naphthalene derivatives, aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acids, acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itacon. Examples thereof include block copolymers consisting of at least two monomers selected from acids, itaconic acid derivatives, fumaric acid, fumaric acid derivatives, etc., random copolymers, or salts thereof.

  These water-soluble resins are alkali-soluble resins that are soluble in an aqueous solution in which a base is dissolved. Among them, a resin having a weight average molecular weight of 3000 to 20000 is used as a dispersion when used in an inkjet recording liquid. It is particularly preferred because of the advantages that it can be reduced in viscosity and can be easily dispersed.

The simultaneous use of the polymer dispersant and the self-dispersing pigment is a preferable combination because an appropriate dot diameter can be obtained. The reason is not clear, but it is thought as follows.
By containing the polymer dispersant, the penetration into the recording paper is suppressed. On the other hand, since the aggregation of the self-dispersing pigment is suppressed by containing the polymer dispersant, the self-dispersing pigment can smoothly spread in the lateral direction. Therefore, it is considered that the dots spread widely and thinly and ideal dots can be formed.

  Moreover, the following are mentioned as a specific example of the water-soluble surfactant which can be used as a dispersing agent. For example, anionic surfactants include higher fatty acid salts, alkyl sulfates, alkyl ether sulfates, alkyl ester sulfates, alkyl aryl ether sulfates, alkyl sulfonates, sulfosuccinates, alkyl allyls and alkyl naphthalene sulfonic acids. Examples thereof include salts, alkyl phosphates, polyoxyethylene alkyl ether phosphate esters, and alkyl allyl ether phosphates. Examples of the cationic surfactant include alkylamine salts, dialkylamine salts, tetraalkylammonium salts, benzalkonium salts, alkylpyridinium salts, imidazolinium salts, and the like.

  Furthermore, examples of the amphoteric surfactant include dimethylalkyl lauryl betaine, alkyl glycine, alkyl di (aminoethyl) glycine, imidazolinium betaine and the like. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, sucrose ester, glycerin ester polyoxyethylene ether, sorbitan Examples thereof include polyoxyethylene ethers of esters, polyoxyethylene ethers of sorbitol esters, fatty acid alkanolamides, polyoxyethylene fatty acid amides, amine oxides, and polyoxyethylene alkylamines.

  Further, the pigment can be provided with dispersibility by coating with a resin having a hydrophilic group and encapsulating the pigment.

  As a method for coating a water-insoluble pigment with an organic polymer and microencapsulating, all conventionally known methods can be used. Conventionally known methods include chemical production methods, physical production methods, physicochemical methods, mechanical production methods, and the like. Specifically, interfacial polymerization method, in-situ polymerization method, submerged cured coating method, coacervation (phase separation) method, submerged drying method, melt dispersion cooling method, air suspension coating method, spray drying method , Acid precipitation method, phase inversion emulsification method and the like.

  The interfacial polymerization method is a method in which two types of monomers or two types of reactants are separately dissolved in a dispersed phase and a continuous phase, and both substances are reacted at the interface between the two to form a wall film. The in-situ polymerization method is a method in which a liquid or gas monomer and catalyst, or two reactive substances are supplied from either one of the continuous phase core particles to cause a reaction to form a wall film. The in-liquid cured coating method is a method of forming a wall film by insolubilizing droplets of a polymer solution containing core material particles in a liquid with a curing agent or the like.

  The coacervation (phase separation) method is a method in which a polymer dispersion in which core material particles are dispersed is separated into a coacervate (concentrated phase) and a dilute phase having a high polymer concentration to form a wall film. . In the liquid drying method, a liquid in which a core material is dispersed in a wall membrane material solution is prepared, and the dispersion is put into a liquid in which the continuous phase of this dispersion liquid is not miscible to form a composite emulsion to dissolve the wall membrane material. In this method, the wall film is formed by gradually removing the medium.

  The melt dispersion cooling method uses a wall film material that melts into a liquid state when heated and solidifies at room temperature. This material is heated and liquefied, and the core material particles are dispersed in it and cooled to fine particles. This is a method of forming a wall film. The suspension-in-air coating method is a method of forming a wall membrane by suspending powder core material particles in the air with a fluidized bed and suspending them in an air stream while spraying and mixing the coating solution of the wall membrane material. It is.

  The spray drying method is a method in which an encapsulated stock solution is sprayed and brought into contact with hot air to evaporate and dry volatile components to form a wall film. The acid precipitation method means that at least a part of the anionic group of the organic polymer compound containing an anionic group is neutralized with a basic compound to give water solubility and kneading in an aqueous medium together with a coloring material. After that, neutralization or acidification with an acidic compound is performed, and organic compounds are precipitated and fixed to a coloring material, and then neutralized and dispersed. The phase inversion emulsification method refers to a mixture containing an anionic organic polymer having dispersibility in water and a coloring material as an organic solvent phase, and water is added to the organic solvent phase or This is a method of charging the organic solvent phase.

  Examples of organic polymers (resins) used as the material constituting the microcapsule wall membrane material include polyamide, polyurethane, polyester, polyurea, epoxy resin, polycarbonate, urea resin, melamine resin, phenol resin, and polysaccharide. , Gelatin, gum arabic, dextran, casein, protein, natural rubber, carboxypolymethylene, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, cellulose, ethyl cellulose, methyl cellulose, nitrocellulose, hydroxyethyl cellulose, acetic acid Cellulose, polyethylene, polystyrene, (meth) acrylic acid polymer or copolymer, (meth) acrylic acid ester polymer or copolymer, (meth) acrylic acid (Meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid copolymer, styrene-maleic acid copolymer, sodium alginate, fatty acid, paraffin, beeswax, water wax, hardened beef tallow, carnauba wax, albumin, etc. .

  Among these, organic polymers having an anionic group such as a carboxylic acid group or a sulfonic acid group can be used. Nonionic organic polymers include, for example, polyvinyl alcohol, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate or their (co) polymers, and 2-oxazoline cationic ring-opening polymers. Is mentioned. In particular, a complete saponified product of polyvinyl alcohol is particularly preferable because it has low water solubility and is easily dissolved in hot water but difficult to dissolve in cold water.

  Further, the amount of the organic polymer constituting the wall membrane material of the microcapsule is 1% by weight or more and 20% by weight or less based on the water-insoluble colorant such as an organic pigment or carbon black. By setting the amount of the organic polymer within the above range, the content of the organic polymer in the capsule is relatively low so that the pigment develops due to the organic polymer covering the pigment surface. Can be suppressed. If the amount of the organic polymer is less than 1% by weight, it is difficult to exert the effect of encapsulation. Conversely, if the amount exceeds 20% by weight, the color developability of the pigment is significantly reduced. In consideration of other characteristics, the amount of the organic polymer is preferably in the range of 5 to 10% by weight based on the water-insoluble colorant.

  That is, since a part of the color material is exposed without being substantially covered, it is possible to suppress a decrease in color developability, and conversely, a part of the color material is not substantially exposed without being exposed. Since it is coated, it is possible to simultaneously exhibit the effect that the pigment is coated. The number average molecular weight of the organic polymers is preferably 2000 or more from the viewpoint of capsule production. Here, “substantially exposed” means not the partial exposure associated with defects such as pinholes and cracks, but a state where it is intentionally exposed.

  Furthermore, if an organic pigment or self-dispersing carbon black, which is a self-dispersing pigment, is used as a colorant, the dispersibility of the pigment is improved even if the content of the organic polymer in the capsule is relatively low. Furthermore, it is more preferable because sufficient storage stability of the ink can be ensured.

  It is preferable to select an organic polymer suitable for the microencapsulation method. For example, in the case of interfacial polymerization, polyester, polyamide, polyurethane, polyvinyl pyrrolidone, epoxy resin and the like are suitable. In the case of using the in-situ polymerization method, a polymer or copolymer of (meth) acrylic acid ester, (meth) acrylic acid- (meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid copolymer, Polyvinyl chloride, polyvinylidene chloride, polyamide and the like are suitable. In the case of the liquid curing method, sodium alginate, polyvinyl alcohol, gelatin, albumin, epoxy resin and the like are suitable. In the case of the coacervation method, gelatin, celluloses, casein and the like are suitable. In addition, in order to obtain a fine and uniform microencapsulated pigment, it is possible to use all conventionally known encapsulation methods other than those described above.

  When the phase inversion method or the acid precipitation method is selected as the microencapsulation method, anionic organic polymers are used as the organic polymers constituting the wall membrane material of the microcapsules. The phase inversion method is a composite or composite of an anionic organic polymer having self-dispersibility or solubility in water and a colorant such as a self-dispersion organic pigment or self-dispersion carbon black, or a self-dispersion method. A mixture of a colorant such as a dispersible organic pigment or self-dispersing carbon black, a curing agent, and an anionic organic polymer is used as an organic solvent phase, and water is added to the organic solvent phase, or the organic solvent is submerged in water. In this method, a solvent phase is introduced and microencapsulation is performed while self-dispersion (phase inversion emulsification) is performed. In the above phase inversion method, there is no problem even if the organic solvent phase is mixed with a recording liquid vehicle or additives. In particular, it is more preferable to mix a liquid medium of a recording liquid because a dispersion liquid for recording liquid can be directly produced.

  On the other hand, in the acid precipitation method, a part or all of the anionic group of the anionic group-containing organic polymer is neutralized with a basic compound, and a colorant such as a self-dispersing organic pigment or self-dispersing carbon black, A water-containing cake obtained by a production method comprising a step of kneading in an aqueous medium and a step of neutralizing and acidifying an acidic compound to precipitate an anionic group-containing organic polymer and fixing it to a pigment, This is a method of microencapsulation by neutralizing a part or all of an anionic group using a compound. By doing in this way, the aqueous dispersion containing the anionic microencapsulated pigment which is fine and contains many pigments can be manufactured.

  Examples of the solvent used for microencapsulation as described above include alkyl alcohols such as methanol, ethanol, propanol and butanol; aromatic hydrocarbons such as benzol, toluol and xylol; methyl acetate Esters such as ethyl acetate and butyl acetate; Chlorinated hydrocarbons such as chloroform and ethylene dichloride; Ketones such as acetone and methyl isobutyl ketone; Ethers such as tetrahydrofuran and dioxane; Cellosolves such as methyl cellosolve and butyl cellosolve Etc. The microcapsules prepared by the above method are once separated from these solvents by centrifugation or filtration, and this is stirred and redispersed with water and the necessary solvent to obtain the desired recording liquid. The average particle diameter of the encapsulated pigment obtained by the above method is preferably 50 nm to 180 nm.

  By coating the resin in this way, the pigment adheres firmly to the printed material, whereby the scratching property of the printed material can be improved.

〔dye〕
As the dye used in the recording liquid, dyes classified into acid dyes, direct dyes, basic dyes, reactive dyes, and food dyes in the color index and having excellent water resistance and light resistance are used. These dyes may be used as a mixture of a plurality of types, or may be used as a mixture with other color materials such as pigments as necessary.

(A) As an acid dye and a food dye,
C. I. Acid Yellow 17, 23, 42, 44, 79, 142
C. I. Acid Red 1,8,13,14,18,26,27,35,37,42,52,82,87,89,92,97,106,111,114,115,134,186,249,254 289
C. I. Acid Blue 9, 29, 45, 92, 249
C. I. Acid Black 1, 2, 7, 24, 26, 94
C. I. Food Yellow 3, 4
C. I. Food Red 7, 9, 14
C. I. Food Black 1, 2

(B) As a direct dye,
C. I. Direct yellow 1,12,24,26,33,44,50,86,120,132,142,144
C. I. Direct Red 1,4,9,13,17,20,28,31,39,80,81,83,89,225,227
C. I. Direct orange 26, 29, 62, 102
C. I. Direct blue 1,2,6,15,22,25,71,76,79,86,87,90,98,163,165,199,202
C. I. Direct black 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 154, 168, 171

(C) As a basic dye,
C. I. Basic yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 64, 65 67, 70, 73, 77, 87, 91
C. I. Basic Red 2,12,13,14,15,18,22,23,24,27,29,35,36,38,39,46,49,51,52,54,59,68,69,70 73, 78, 82, 102, 104, 109, 112
C. I. Basic blue 1,3,5,7,9,21,22,26,35,41,45,47,54,62,65,66,67,69,75,77,78,89,92,93 , 105, 117, 120, 122, 124, 129, 137, 141, 147, 155
C. I. Basic Black 2,8

(D) As a reactive dye,
C. I. Reactive Black 3, 4, 7, 11, 12, 17
C. I. Reactive Yellow 1,5,11,13,14,20,21,22,25,40,47,51,55,65,67
C. I. Reactive Red 1,14,17,25,26,32,37,44,46,55,60,66,74,79,96,97
C. I. Reactive Blue 1, 2, 7, 14, 15, 23, 32, 35, 38, 41, 63, 80, 95, etc. can be used.

[Additives and physical properties common to dyes and pigments]
In order to make the recording liquid used in the image forming apparatus according to the present invention have the desired physical properties or to prevent clogging of the nozzles of the recording head due to drying, a water-soluble organic solvent is used in addition to the colorant. It is preferable to do. The water-soluble organic solvent includes a wetting agent and a penetrating agent. The wetting agent is added for the purpose of preventing clogging of the nozzles of the recording head due to drying.

  Specific examples of the wetting agent include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, 1,3-butanediol, 1,3-propanediol, and 2-methyl-1,3-propane. Diol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, 1,2 Polyhydric alcohols such as 1,4-butanetriol, 1,2,3-butanetriol, and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene Polyhydric alcohol alkyl ethers such as glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether and propylene glycol monoethyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether Forehead: Nitrogen-containing heterocyclic compounds such as N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam; formamide, N-methylformamide, Amides such as formamide and N, N-dimethylformamide; monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethyl And amines such as ruamine, sulfur-containing compounds such as dimethyl sulfoxide, sulfolane and thiodiethanol, propylene carbonate, ethylene carbonate, and γ-butyrolactone. These solvents are used alone or in combination with water.

  Further, the penetrant is added for the purpose of improving the wettability between the recording liquid and the recording material and adjusting the penetration speed. As the penetrant, those represented by the following formulas (I) to (IV) are preferable. That is, a polyoxyethylene alkylphenyl ether surfactant of formula (I) below, an acetylene glycol surfactant of formula (II), a polyoxyethylene alkyl ether surfactant of formula (III) below and formula (IV) The polyoxyethylene polyoxypropylene alkyl ether-based surfactant (1) can reduce the surface tension of the liquid, so that the wettability can be improved and the penetration rate can be increased.

（Ｒは分岐していても良い炭素数６〜１４の炭化水素鎖、ｋは５〜２０）

(R is an optionally branched hydrocarbon chain having 6 to 14 carbon atoms, k is 5 to 20)

（ｍ、ｎは０〜４０）

(M and n are 0 to 40)

（Ｒは分岐していても良い炭素数６〜１４の炭化水素鎖、ｎは５〜２０）

(R is an optionally branched hydrocarbon chain having 6 to 14 carbon atoms, n is 5 to 20)

（Ｒは炭素数６〜１４の炭化水素鎖、ｍ、ｎは２０以下の数）

(R is a hydrocarbon chain having 6 to 14 carbon atoms, m and n are numbers of 20 or less)

  Other than the compounds of the above formulas (I) to (IV), for example, diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, tetraethylene glycol chlorophenyl Use alkyl and aryl ethers of polyhydric alcohols such as ethers, nonionic surfactants such as polyoxyethylene polyoxypropylene block copolymers, fluorine-based surfactants, lower alcohols such as ethanol and 2-propanol However, diethylene glycol monobutyl ether is particularly preferable.

  The surface tension of the recording liquid used in the image forming apparatus according to the present invention is preferably 10 to 60 N / m, and 15 to 30 N from the viewpoint of achieving both wettability with the recording medium and droplet formation. More preferably, it is / m.

  Similarly, the viscosity of the recording liquid is preferably in the range of 1.0 to 30 mPa · s, and from the viewpoint of ejection stability, it is preferably in the range of 5.0 to 20 mPa · s.

  The pH of the recording liquid is preferably in the range of 3 to 11, and more preferably in the range of 6 to 10 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

  Further, the recording liquid can contain an antiseptic / antifungal agent. By containing the antiseptic / antifungal agent, the growth of bacteria can be suppressed, and the storage stability and the image quality stability can be improved. As antiseptic / antifungal agents, benzotriazole, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, isothiazoline compounds, sodium benzoate, sodium pentachlorophenol, and the like can be used.

  Further, the recording liquid can contain a rust inhibitor. By containing a rust preventive agent, a coating can be formed on the metal surface in contact with the liquid, such as a head, and corrosion can be prevented. As the rust inhibitor, for example, acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like can be used.

  Further, the recording liquid can contain an antioxidant. By containing an antioxidant, even when radical species that cause corrosion are generated, the antioxidant can be prevented by eliminating the radical species.

  Typical examples of the antioxidant include phenolic compounds and amine compounds. Examples of the phenolic compounds include hydroquinone and gallate compounds, 2,6-di-tert-butyl-p-cresol, and stearyl. -Β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl- 6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-4-hydroxybenzyl) benzene, Hindered materials such as lith (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, tetrakis [methylene-3 (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionate] methane Phenol compounds are exemplified, and amine compounds include N, N′-diphenyl-p-phenylenediamine, phenyl-β-naphthylamine, phenyl-α-naphthylamine, N, N′-β-naphthyl-p-phenylene. Examples include diamine, N, N′-diphenylethylenediamine, phenothiazine, N, N′-di-sec-butyl-p-phenylenediamine, 4,4′-tetramethyl-diaminodiphenylmethane, and the like. Further, as the latter, sulfur compounds and phosphorus compounds are representative, but as sulfur compounds, dilauryl thiodipropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, dithiol. Examples include myristyl thiodipropionate, distearyl β, β′-thiodibutyrate, 2-mercaptobenzimidazole, dilauryl sulfide and the like, and phosphorus compounds include triphenyl phosphite, trioctadecyl phosphite, tridecyl. Examples include phosphite, trilauryl trithiophosphite, diphenylisodecyl phosphite, trinonylphenyl phosphite, distearyl pentaerythritol phosphite.

  The recording liquid can contain a pH adjusting agent. Examples of the pH adjuster include hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, lithium carbonate, Examples include alkali metal carbonates such as sodium carbonate and potassium carbonate, amines such as diethanolamine and triethanolamine, boric acid, hydrochloric acid, nitric acid, sulfuric acid, and acetic acid.

  The image forming apparatus according to the present invention is not limited to a printer having a single function configuration, and may be an image forming apparatus having a composite function such as printer / facsimile / copying. It may be applied to an image forming apparatus. Further, the present invention can be applied not only to a liquid recovery container that recovers and stores a liquid as a recording liquid, but also to a liquid recovery container that recovers and stores other liquids.

FIG. 3 is a perspective explanatory view seen from the front side of the ink jet recording apparatus as the image forming apparatus according to the present invention. It is a side schematic block diagram explaining the whole structure of the mechanism part of the apparatus. It is principal part plane explanatory drawing of the mechanism part. It is a perspective explanatory view of the liquid recovery container concerning the present invention. It is a perspective explanatory view explaining the inside of the lid member of the same liquid recovery container. It is a perspective explanatory view explaining the outside of the lid member. FIG. 7 is a cross-sectional explanatory diagram of a plane A in FIG. It is typical explanatory drawing with which it uses for description of an effect | action of the same liquid collection | recovery container.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Apparatus main body 2 ... Paper feed tray 3 ... Paper discharge tray 4 ... Cartridge loading part 10k, 10c, 10m, 10y ... Ink cartridge 33 ... Carriage 34 ... Recording head 35 ... Head tank 36 ... Ink supply tube 51 ... Conveying belt 88 ... Liquid recovery container (ink recovery unit)
89 ... Opening 101 ... Container body 102 ... Lid member 111, 112 ... Rib

Claims (9)

  In a liquid recovery container that receives liquid droplets that are discharged from a liquid discharge head, at least a container main body that stores the liquid that is waste liquid, and a lid member that covers the container main body and that has an opening through which the liquid droplets pass. And the lid member has ribs that fall on both sides of the opening toward the liquid storage part of the container body.   The liquid recovery container according to claim 1, wherein the rib has a height of 5 mm or more.   The liquid recovery container according to claim 1, wherein the rib is provided in parallel with the opening.   4. The liquid recovery container according to claim 1, wherein the rib is separated from the periphery of the opening by a predetermined distance. 5.   The liquid recovery container according to claim 4, wherein the rib is separated from the periphery of the opening by 1 mm or more.   6. The liquid recovery container according to claim 1, comprising a plurality of ribs having different heights.   7. The liquid recovery container according to claim 1, wherein the rib has a length that is at least 2/3 or more of the longitudinal length of the opening.   8. An apparatus for ejecting liquid droplets from a liquid ejection head, comprising the liquid recovery container according to any one of claims 1 to 7. An image forming apparatus for forming an image by discharging liquid droplets from a liquid discharge head, comprising: a liquid recovery container according to any one of claims 1 to 7;

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