JP5322818B2 - Inkjet recording method and inkjet recording apparatus - Google Patents

Description

  The present invention relates to an ink jet recording method and an ink jet recording apparatus for recording information on a recording medium by adhering the recording liquid to a recording medium such as PPC paper, and more specifically, recording in which information is recorded by attaching the recording liquid. The present invention relates to an ink jet recording method and an ink jet recording apparatus in which a medium is conveyed by a roller.

  Conventionally, an aqueous recording liquid (ink) containing at least water and a colorant is attached to a recording medium such as PPC (Plain Paper Copier) paper based on information acquired by itself or transmitted from another device. Therefore, an ink jet recording apparatus that records the above information on the recording medium is known. As such an ink jet recording apparatus, for example, a transport belt for transporting a recording medium and a large number of ink ejection ports (nozzles) for ejecting and attaching a recording liquid to the recording medium transported by the transport belt. There is a recording head having a recording head and a roller for transporting a recording medium to which a recording liquid is attached by the recording head toward a discharge unit. In such an apparatus, while the recording medium is conveyed by the traveling of the conveying belt, the recording liquid is ejected from the recording head toward the recording medium to record information. The recording medium on which the information is recorded is transferred from the conveyance belt to the roller, and is conveyed to the discharge unit by this roller.

  In such an ink jet recording apparatus, in order to perform large-scale high-speed printing such as 100 to 150 sheets / minute, in addition to increasing the driving frequency of the recording head that discharges the recording liquid, it is the same as the width of the recording medium. It is proposed to use a line type recording head having a length longer than that. That is, when a long line type recording head is used instead of a serial type recording head that discharges a recording liquid while scanning the recording head in a direction orthogonal to the conveyance direction of the recording medium, the recording head is arranged in the width of the recording medium. Since the recording liquid can be discharged simultaneously over the entire width of the recording medium while being fixed to the apparatus main body so as to extend in the direction, a markedly higher processing speed is realized compared to the serial type recording head.

  However, if the high speed processing of the ink jet recording apparatus is achieved, the time from when the recording liquid is ejected to the recording medium until the roller contacts the recording medium is shortened, and before the recording liquid penetrates the recording medium (in other words, In this case, the roller comes into contact with the recording medium while the recording liquid is not sufficiently dried, and the possibility that the recording liquid adheres to the roller surface increases. As a result, the density of the image formed on the recording medium is reduced, the image is chipped or disturbed, and the recording medium is wound around the roller.

  Further, the recording liquid adhering to the roller surface is transferred to a non-recording portion of the recording medium (a portion of the recording medium to which no recording liquid is attached: for example, a peripheral portion or a side edge portion of the recording medium) to contaminate the recording medium. In the case where printing is continuously performed on a plurality of recording media, the recording liquid adhering to the roller surface is transferred to a subsequent recording medium, and the plurality of recording media are soiled.

  In this regard, Patent Document 1 discloses a technique in which an unnecessary solvent of the recording liquid remaining on the recording medium is absorbed and removed by a solvent absorbing roller after the recording liquid is discharged onto the recording medium (paragraph 0004). , 0064, 0081 and FIG. 1).

JP 2006-263984 A

  However, since the above technique attempts to remove only the solvent by bringing the solvent absorbing roller into contact with the recording medium after the recording liquid is adhered, the recording medium conveyance speed and the rotating speed of the absorbing roller are If they are not synchronized well, the image formed on the recording medium may be disturbed, and it is difficult to achieve a large speed processing. Further, it is necessary to periodically clean and replace the solvent absorbing roller.

  The present invention addresses the above problems in an ink jet recording method and an ink jet recording apparatus for recording information by attaching a recording liquid to a recording medium. In order to realize high-speed processing, the recording liquid is applied to the recording medium. It is an object of the present invention to solve the problem that the recording liquid adheres to the roller surface without using a solvent absorbing roller even if the time from when the roller is attached until the roller comes into contact with the recording medium is shortened.

  That is, the present invention is an ink jet recording method having a recording step for attaching a recording liquid to a recording medium and a conveying step for conveying the recording medium to which the recording liquid is attached by a roller. A roller made of a material having excellent aqueous properties is used, and a water-insoluble liquid is supplied to the roller surface in the conveying step. According to the present invention, since the roller surface repels the aqueous recording liquid, even if the roller comes into contact with the recording medium in which the recording liquid is not sufficiently dried, the recording liquid is prevented from adhering to the roller surface.

  In that case, it is preferable that the SP value of the material having excellent water repellency and the SP value of the water-insoluble liquid are 6 to 11. In this way, the roller surface and the water-insoluble liquid have SP values close to each other, so that the roller surface becomes easy to become familiar with, and the roller surface is easily wetted with the water-insoluble liquid. It will be held stably. On the other hand, since the SP value of the roller surface and the water-insoluble liquid and the aqueous recording liquid are far from each other (the SP value of the aqueous recording liquid is 23 to 25), the water repellency of the roller surface is reliably maintained, The recording liquid adheres to the roller surface with certainty.

  Further, in that case, it is preferable not to supply the water-insoluble liquid to the portion of the roller surface that contacts the portion of the recording medium to which the recording liquid is not attached (non-recording portion of the recording medium). Since the roller surface to which the water-insoluble liquid is supplied tends to have a small friction coefficient, the water-insoluble liquid is not unnecessarily supplied to the portion of the roller surface where there is no need to worry about the adhesion of the recording liquid. Thus, slip between the roller and the recording medium is avoided, and the recording medium is reliably conveyed at high speed by the roller.

  The present invention also provides an ink jet recording apparatus having a recording head for attaching a recording liquid to a recording medium and a roller for transporting the recording medium to which the recording liquid is attached. It is made of a material excellent in water and has a supply means for supplying a water-insoluble liquid to the roller surface. Also according to this invention, since the roller surface repels the aqueous recording liquid, even if the recording liquid adhered to the recording medium is insufficiently dried, the adhesion of the recording liquid to the roller surface is suppressed. .

  The present invention relates to an ink jet recording method and an ink jet recording apparatus in which a recording medium to which a recording liquid is attached and information is recorded is conveyed by a roller. However, even if it is in contact with an insufficient recording medium, there is a remarkable effect that adhesion of the recording liquid to the roller surface is suppressed.

1 is a schematic configuration diagram of an ink jet recording apparatus suitable for carrying out an ink jet recording method according to the present invention. FIG. 2 is an enlarged vertical cross-sectional view of a dot forming portion provided in a recording head of the ink jet recording apparatus.

  The present invention relates to an ink jet recording method and an ink jet recording apparatus, wherein the surface of a roller for conveying a recording medium to which a recording liquid is attached and information is recorded is made of a material having excellent water repellency, and the surface of the roller is non-coated. It is characterized by supplying a water-soluble liquid. The supply of the water-insoluble liquid to the roller surface is performed at least during the conveyance of the recording medium by the roller, that is, during the rotation of the roller.

(roller)
The roller according to the present invention is for conveying a recording medium on which recording liquid is attached and information is recorded, and the surface is made of a material having excellent water repellency. As a result, when a water-insoluble liquid is supplied to the roller surface, the roller surface repels the aqueous recording liquid, and even if the recording liquid attached to the recording medium is not dried, the recording liquid is applied to the roller surface. Adhesion is suppressed.

  Specific examples of materials that can be used in the present invention and have excellent water repellency constituting the roller surface will be described below. In addition, the numerical value in a parenthesis is SP value (Solubility Parameter: Solubility parameter).

  That is, polytetrafluoroethylene (6.2), fluororubber (7.3), silicone rubber (7.3-7.6), butyl rubber (7.7-8.1), ethylene propylene rubber (8), Polyethylene (7.7 to 8.4), chlorosulfonated polyethylene (8.1 to 9.8), natural rubber (7.9 to 8.4), isoprene rubber (8.13), butadiene rubber (8. 1-8.6), styrene butadiene rubber (SBR) (8.1-8.7), polystyrene (8.5-10.3), chloroprene rubber (CR) (8.1-9.4), nitrile Rubber (NBR) (8.7-9.9), polysulfide rubber (9.0-9.4), chlorinated rubber (9.4), acrylic rubber (9.5), polyvinyl chloride (PVC) ( 9.4 to 10.8), urethane rubber (10), polyethylene terf Rate (PET) (10.7), epoxy resin (10.9) and the like.

  Thus, all the above materials have SP values in the range of 6-11. On the other hand, an aqueous recording liquid containing at least water and a colorant has an SP value of approximately 23 to 25. Therefore, since the SP value on the roller surface and the SP value of the aqueous recording liquid are values far from each other, the water repellency on the roller surface is reliably maintained and the adhesion of the recording liquid to the roller surface is reliably suppressed. It becomes.

  The roller according to the present invention can be produced, for example, by covering the peripheral surface of a cylindrical cored bar with an elastic body made of the above material formed in a bamboo ring shape.

(Water-insoluble liquid)
The water-insoluble liquid according to the present invention is a liquid having a low solubility in water (for example, a liquid having a solubility in water at 25 ° C. of 20% by mass or less, preferably 15% by mass or less, more preferably 10% by mass or less). It is supplied to the roller surface made of a material excellent in water repellency. As a result, the roller surface repels the aqueous recording liquid, and even if the recording liquid adhered to the recording medium is not dried, the adhesion of the recording liquid to the roller surface is suppressed.

  Specific examples of the water-insoluble liquid supplied to the roller surface that can be used in the present invention are described below (the numerical values in parentheses are SP values).

  That is, n-pentane (7), n-hexane (7.3), heptane, n-octane (7.6), nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, cyclohexane (8 .2), petroleum ether, hydrofluoroether (6.23), diethyl ether (7.4), dioctyl ether, diphenyl ether, benzene (9.2), toluene (8.9), xylene (8.8), Ethylbenzene (8.8), dimethoxybenzene, chlorobenzene, benzonitrile, ethyl methyl ketone (9.3), methyl isobutyl ketone, ethyl acetate (9.1), butyl acetate (8.5), methylene chloride (9.7) ), Chloroform, butanol, n-hexanol (10.7), dinonyl ester Ether, dimethyl polysiloxane, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The water-insoluble liquid according to the present invention preferably has an SP value in the range of 6 to 11. As a result, both the roller surface and the water-insoluble liquid have SP values of 6 to 11, and the SP values are close to each other. Therefore, the roller surface and the water-insoluble liquid are easily adapted to each other. This is because the water-soluble liquid is easily wetted and the water-insoluble liquid is stably held on the roller surface. In addition, the SP value of the aqueous recording liquid is approximately 23 to 25, and the SP value of the water-insoluble liquid and the aqueous recording liquid is far from each other. This is because the adhesion of the recording liquid to the surface is surely suppressed.

  That is, the water-insoluble liquid used in the present invention is a liquid having a low water repellency with respect to the roller surface and a high water repellency with respect to the aqueous recording liquid. Therefore, by using such a water-insoluble liquid, the surface treatment of the roller becomes good and easy, and it is possible to effectively and reliably prevent the recording liquid from adhering to the roller surface.

  Further, the SP value of the water-repellent material constituting the roller surface and the water-insoluble liquid supplied to the roller surface is preferably 6 to 11, both in terms of increasing the water repellency with respect to the aqueous recording liquid. More preferably, both SP values are 6 to 10, and more preferably, both SP values are 6 to 9. Further, from the viewpoint that the water-insoluble liquid is stably held on the roller surface, the SP value is as close as possible between the material having excellent water repellency and the water-insoluble liquid. preferable.

  Further, from the viewpoint of work environment and work safety, the water-insoluble liquid preferably has a boiling point of 70 ° C. or higher.

  In light of the purpose of suppressing the recording liquid adhering to the recording medium from adhering to the roller surface, it is only necessary to supply the water-insoluble liquid to the roller surface, and the supply amount is not particularly problematic. The supply amount of the water-insoluble liquid to the roller surface may be changed according to the type of the water-insoluble liquid and the type of the roller surface constituent material. When the supply amount of the water-insoluble liquid is excessively small, the effect of preventing the recording liquid from adhering to the roller surface tends to be insufficient. On the other hand, if the supply amount of the water-insoluble liquid is excessively large, it tends to be unfavorable in terms of conveyance of the recording medium and the environment.

  By the way, during the conveyance of the recording medium by the roller, the portion of the roller surface that comes into contact with the non-recording portion of the recording medium (the portion of the recording medium to which no recording liquid is attached: for example, the peripheral edge or the side edge of the recording medium) It is preferable not to supply water-insoluble liquid to the peripheral surfaces of both ends in the length direction of the roller. In light of the objective of suppressing the recording liquid adhering to the recording medium from adhering to the roller surface, it is unnecessary to supply the water-insoluble liquid to the portion of the roller surface that contacts the non-recording portion of the recording medium. It is. Further, if water-insoluble liquid is supplied to the entire surface of the roller, slip may occur between the roller surface and the recording medium. Therefore, by leaving a portion on the roller surface that does not supply water-insoluble liquid, The grip force of the recording medium is maintained, and the recording medium can be reliably conveyed at high speed without causing the roller to slip.

(Recording liquid)
The recording liquid, i.e., ink that can be used in the present invention contains at least water and a colorant. In addition, for example, a polymer dispersant, a surfactant (as a wetting agent or a surface tension adjusting agent), or a water-soluble organic solvent (penetration) Etc.) can be added as accelerators or drying inhibitors.

  As the colorant, any of direct dyes, acid dyes, basic dyes and other dyes and pigments can be used. In the present invention, a pigment is preferably used from the viewpoints of high optical density, water resistance, light resistance and the like.

  Examples of pigments that can be used in the present invention include insoluble azo pigments, soluble azo pigments, phthalocyanine blue, isoindolinone, quinacridone, dioxazine violet, organic pigments such as verinone / betalin, and inorganic pigments such as carbon black and titanium dioxide. Examples thereof include colorant pigment components and extender pigments such as white clay, talc, clay, diatomaceous earth, calcium carbonate, barium sulfate, titanium oxide, alumina white, silica, kaolin, and aluminum hydroxide.

  More specifically, black (K) pigments include furnace black, lamp black, acetylene black, channel black and other carbon blacks (CI Pigment Black 7), copper oxide, iron oxide (CI pigment black 11) or metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1) can be mentioned. The above can be used in combination.

  Examples of yellow (Y) pigments include C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 12 (Disazo Yellow AAA), 13, 14, 17, 23, 24, 34, 35, 37, 42 (Yellow Iron Oxide), 53, 55, 74, 81, 83 (Disazo Yellow HR), 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 150, 153, etc. Or two or more types can be used in combination.

  Examples of magenta (M) pigments include C.I. I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 2 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B (Ca)), 48 : 3 (Permanent Red 2B (Sr)), 48: 4 (Permanent Red 2B (Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81 (Rhodamine 6G Lake), 83, 88, 92, 101 (Bengara), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Dimethylquinacridone), 123,146,149,166,168,170,172,177,178,179,185,190,193,209,2 9 and the like can be mentioned, depending on the situation, can be used in combination either singly or in combination.

  Examples of cyan (C) pigments include C.I. I. Pigment Blue 1, 2, 15 (copper phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue G), 15: 4, 15: 6 (phthalocyanine blue E), 16, 17: 1, 56, 60, 63, etc. can be mentioned, According to the situation, it can be used individually by 1 type or in combination of 2 or more types.

  The content of the colorant in the total amount of the recording liquid varies depending on the purpose of use, but the coloring power and the viscosity of the ink (the higher the colorant content, the higher the viscosity of the ink and the more difficult it is to be ejected). From the balance, it is 0.1 to 20% by mass, preferably 1 to 10% by mass, more preferably 3 to 7% by mass.

  Further, a water-soluble resin may be added as a polymer dispersant for dispersing a colorant (particularly a pigment) in an ink solvent. Preferred examples of the polymer dispersant include acrylic-styrene resin, styrene-acrylic-alkyl acrylate copolymer, styrene-acrylic acid copolymer, styrene-maleic acid copolymer, and styrene-maleic acid-acrylic. Acid alkyl ester copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid alkyl ester copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer Examples thereof include water-soluble resins such as polymers.

  The content of the water-soluble resin (as a polymer dispersant) in the total amount of the recording liquid is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass. Two or more of these water-soluble resins can be used in combination.

  As a method for dispersing the colorant (particularly pigment), a ball mill, a sand mill, a roll mill, an agitator, an ultrasonic homogenizer, a wet jet mill, a paint shaker, or the like can be used.

  A high-concentration colorant (particularly pigment) dispersion prepared separately for preparing the recording liquid of the present invention is centrifuged at the time of preparation in order to remove foreign matters, dust, coarse particles, and the like during dispersion. It is preferred to use a separation device. When the recording liquid of the present invention is finally prepared, it is preferably filtered using a filter.

  The average particle diameter of the pigment particles usable in the present invention is preferably 30 to 300 nm, more preferably 50 to 150 nm. The average particle diameter can be measured using, for example, a dynamic light scattering particle size distribution measuring apparatus (“LB-550” manufactured by Horiba, Ltd.).

  As the surfactant (wetting agent or surface tension adjusting agent) used in the recording liquid in the present invention, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene are used. Nonionic surfactants such as block copolymers are preferably used.

  In the present invention, the recording liquid can obtain a desired surface tension by adjusting the addition amount of the surfactant (wetting agent or surface tension adjusting agent).

  Examples of the water-soluble organic solvent (penetration accelerator or anti-drying agent) used in the recording liquid in the present invention include ethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, diethylene glycol monomethyl ether, and ethylene glycol monomethyl ether. , Triethylene glycol, hexylene glycol, octanediol, thiodiglycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-2-methyl- 1,3-propanediol, 2,4-pentanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol trimethylolpropane, 2-methyl-1,3-propanediol, di Ji glycol, propylene glycol, 1,3-butanediol, ethylene glycol, glycerine, 2-pyrrolidone, and the like.

  In the present invention, the recording liquid can have a desired viscosity by adjusting the amount of the water-soluble organic solvent (penetration accelerator or anti-drying agent) added. The viscosity of the recording liquid can be measured using a viscometer such as a vibration type viscometer (“SV-10” manufactured by A & D).

  The recording liquid of the present invention may further contain, for example, a pH adjuster, an antifoaming agent, a preservative, or the like, if necessary.

  The recording liquid of the present invention can be prepared by mixing the raw materials as described above, sufficiently stirring, removing coarse particles, and filtering with a filter.

(Inkjet recording device)
Next, an example of a specific configuration of an ink jet recording apparatus suitable for carrying out the ink jet recording method of the present invention using the processing liquid for ink jet recording of the present invention will be described.

  As shown in FIG. 1, the ink jet recording apparatus 1 forms an image on a recording medium using a recording liquid based on image information read by itself or image information transmitted from another device (recording information). ) Inkjet printer.

  The ink jet recording apparatus 1 includes a paper storage unit that stores recording media X such as PPC paper in a stacked state in a paper feeding cassette (not shown). The recording medium X is taken out one by one from the uppermost one by the rotation of the take-out roller 2 and is supplied to the paper transport unit by the rotation of the paper feed rollers 3.

  The paper transport unit includes an endless transport belt 6 wound horizontally between a pair of rollers. The recording medium X supplied by the sheet feeding rollers 3... 3 is conveyed to the image forming unit with the recording surface facing upward as the conveyance belt 6 travels.

  The image forming unit includes a long line-type inkjet recording head 5 having a length equal to or greater than the width of the recording medium X conveyed by the conveyance belt 6 above the conveyance belt 6. The recording head 5 is fixed to the main body of the inkjet recording apparatus 1 so as to extend in the width direction of the recording medium X. As will be described later, the recording head 5 has a large number of ink discharge ports (nozzles) of the dot forming portion arranged on the lower surface facing the conveyance belt 6 or the recording medium X, and the recording liquid is applied over the entire width of the recording medium X. By discharging simultaneously, an image can be formed on the recording medium X at high speed. The recording head 5 can adjust the distance between its lower surface (nozzle surface) and the recording medium X on the conveying belt 6.

  A recording medium detection sensor 4 for detecting the leading end of the recording medium X conveyed by the conveying belt 6 is provided above the conveying belt 6 and upstream of the recording head 5. A recording liquid discharge command is output to the recording head 5 with reference to the detection time of the sensor 4.

  The recording medium X on which the recording liquid is adhered by the recording head 5 and an image is formed on the recording surface (information is recorded) is conveyed by the conveying belt 6 while being conveyed by the conveying belt 6. 6 is transferred to a pair of upper and lower conveying rollers 7 and 8 at the end portion 6 and discharged from the conveying belt 6, and by rotation of the conveying rollers 7 and 8, toward the discharging portion outside the figure of the inkjet recording apparatus 1. Are transported. At this time, the upper conveying roller 7 (corresponding to the “roller” defined in the claims) is in contact with the recording surface of the recording medium X on which an image is formed (the recording liquid is attached). Therefore, there is a possibility that the recording liquid on the recording surface adheres to the surface of the conveying roller 7 and becomes dirty.

  Therefore, in the ink jet recording apparatus 1, the surface of the upper transport roller 7 is made of the material having excellent water repellency, and the water-insoluble liquid is supplied to the surface of the upper transport roller 7. A roll coater 9 (corresponding to the “water-insoluble liquid supply means” defined in the claims) is provided. The roll coater 9 includes a container 10 that stores a water-insoluble liquid, a pumping roller 11 that pumps the water-insoluble liquid from the container 10, and a water-insoluble liquid that is received from the pumping roller 11 and receives the water-insoluble liquid. An application roller 12 that is applied to the surface of the upper conveying roller 7 and a control blade 13 that controls the amount of water-insoluble liquid supplied onto the surface of the upper conveying roller 7 are included. The roll coater 9 adjusts the immersion amount of the pumping roller 11 into the container 10, the contact pressure between the rollers 11, 12, 7, the position of the control blade 13 with respect to the upper transport roller 7, etc. The amount of water-insoluble liquid supply per unit area of the surface can be adjusted.

  FIG. 2 is an enlarged longitudinal sectional view showing one of the dot forming portions 50 arranged in a large number on the ink jet recording head 5 of the ink jet recording apparatus 1.

  The recording head 5 is a long line-type recording head 5 extending in the width direction of the recording medium X, and the dot forming section 50 and the nozzles (ink discharge ports) 53 are arranged in four rows in the conveyance direction of the recording medium X. Are lined up. The pitch between the adjacent nozzles 53 and 53 in the same row is 150 dpi, and the position of the nozzle 53 is shifted by a quarter pitch in the width direction of the recording medium X between the adjacent rows, so that the entire recording head 5 is obtained. 600 dpi is realized. The number of dot forming sections 50 and nozzles 53 per row is 166, and 664 are arranged in total (four rows).

  The dot forming unit 50 includes an oval pressurizing chamber 52 in plan view, and one end of the pressurizing chamber 52 is connected to a nozzle 53 formed on the lower surface of the recording head 5 via a nozzle channel 54. The other end portion communicates with the common ink supply path 56 via the throttle path 55. The nozzle 53 has an inverted truncated cone shape in which the diameter of the upper opening 53b is larger than the diameter of the lower opening 53a.

  The dot forming unit 50 includes a first substrate 51a in which a pressurizing chamber 52 is formed, a second substrate 51b in which an upper portion 54a of a nozzle channel 54 and a throttle passage 55 are formed, a lower portion 54b of the nozzle channel 54, and ink. The third substrate 51c on which the common supply path 56 is formed and the fourth substrate 51d on which the nozzle 53 is formed are stacked. A substrate 51 of the recording head 5 is provided by the laminated first to fourth substrates 51a to 51d.

  A piezoelectric actuator AC having a configuration in which a thin plate-like piezoelectric element 58 having a common electrode 57 therein and an individual electrode 59 corresponding to the pressurizing chamber 52 of each dot forming unit 50 are stacked on the upper surface of the substrate 51. It has been. By driving the piezoelectric actuator AC, a pressure wave is transmitted to the ink in the pressurizing chamber 52, and the recording liquid in the nozzle channel 54 and the nozzle 53 is vibrated by the pressure wave, so that the recording liquid is opened below the nozzle 53. The ink is ejected from the recording medium 53a toward the recording medium X.

Here, an example of a preferable specific numerical value regarding the specification of the dot forming portion 50 is shown below.
・ Area of pressurizing chamber 52: 0.2 mm ²
・ Pressure chamber 52 width: 200 μm
-Depth of pressurizing chamber 52: 100 μm
・ Length of nozzle 53: 30 μm
The radius of the lower opening 53a of the nozzle 53: 10 μm
-Diameter of nozzle channel 54: 200 μm
・ Length of nozzle channel 54: 800 μm
-Diameter of throttle passage 55: 30 μm
・ Length of throttle passage 55: 40 μm

  The inkjet recording apparatus 1 illustrated in FIG. 1 has a single recording head 5 and forms an image in a single color. However, the present invention is not limited to this. For example, K (black), Y (yellow) ), M (magenta), and C (cyan), a plurality (four) of individual recording heads 5 may be arranged in the conveyance direction of the recording medium X to form an image in full color. In that case, the recording liquid (one of the four types) is ejected from the last head (the head on the most downstream side) onto the recording medium X as the processing speed increases, and then the upper transport roller 7 moves to the recording medium X. Therefore, the possibility that the recording liquid adheres to the surface of the upper conveying roller 7 is increased.

  In addition, the inkjet recording apparatus 1 may include a serial recording head instead of a line recording head as long as high-speed processing is realized. In that case, as the processing speed increases, the recording roller is brought into contact with the recording medium X after the ink is ejected from the recording head in the last one or two recording head scans. Therefore, the possibility that the recording liquid adheres to the surface of the upper conveying roller 7 is increased.

(Inkjet recording method)
Using the inkjet recording apparatus 1 having the above-described configuration, the surface of the upper conveying roller 7 is made of a material having excellent water repellency, a water-insoluble liquid is charged into the roll coater 9, and an aqueous solution containing at least water and a dressing agent. The recording head 5 is charged into the recording head 5 to cause the recording head 5 to attach the recording liquid to the recording medium X, and the conveying rollers 7 and 8 convey the recording medium X to which the recording liquid is adhered. An upper surface of the upper conveying roller 7 by a roll coater 9 in the conveying step. An ink jet recording method characterized in that a water-insoluble liquid is supplied to the substrate.

  EXAMPLES Hereinafter, although the Example of this invention is given with a comparative example and this invention is demonstrated further more concretely, this invention is not limited by a following example.

<Preparation of recording liquid>
First, a high-concentration pigment dispersion used for the preparation of the recording liquid was prepared with the following composition.
Pigment: C.I. I. 30% by mass of Pigment Red 122 (dimethylquinacridone)
Polymer dispersing agent: 15% by mass of acrylic-styrene resin (“John Crill 61” manufactured by Johnson)
-Anti-drying agent: 10% by mass of glycerin
・ Solvent: 45% by mass of ion-exchanged water

  These raw materials were charged into a batch type vertical sand mill (manufactured by Imex Co., Ltd.), filled with zirconia beads (diameter 0.5 mm) as a medium, and sufficiently dispersed while being cooled with water. After the dispersion treatment, the zirconia beads are removed, and a centrifuge is used to remove foreign matters and coarse particles during dispersion, thereby obtaining a magenta pigment dispersion having a pigment concentration of 30% by mass and an average particle diameter of dispersed pigment particles of 100 nm. It was. The average particle size of the dispersed pigment particles is obtained by diluting the obtained pigment dispersion five times with ion-exchanged water and using a dynamic light scattering particle size distribution measuring device (“LB-550” manufactured by Horiba, Ltd.). Confirmed.

Next, using the obtained pigment dispersion, a recording liquid was prepared with the following composition.
-20% by mass of the above magenta pigment dispersion
Surfactant (or wetting agent or surface tension adjusting agent): 2,4,7,9-tetramethyl-5-decyne-4,7-diol di [polyoxyethylene] ether (manufactured by Nissin Chemical Industry Co., Ltd. Olfin (registered trademark) E1010 ") 0.5% by mass
・ Penetration enhancer: 5% by mass of hexylene glycol
-Anti-drying agent: 5% by mass of 2-pyrrolidone
-Anti-drying agent: 10% by mass of glycerin
-Solvent: 59.5% by mass of purified water

  These raw materials were sufficiently stirred at room temperature, and then pressure filtered with a filter having a pore diameter of 5 μm to obtain a recording liquid for ink jet recording. The viscosity of the obtained recording liquid was 3.0 mPa · s. And the following evaluation was performed using this recording liquid.

(Image evaluation)
An image was formed (information was recorded) as follows using the inkjet printer 1 having the structure shown in FIGS. 1 and 2 (an inkjet printer experimental machine manufactured by Kyocera Mita).

  The recording head 5 of the ink jet printer 1 was filled with the recording liquid prepared as described above, and excess liquid coming out from the lower surface of the nozzle was scraped off with a wipe blade. The recording head 5 was fixed by adjusting the position of the recording head 5 so that the distance between the nozzle surface of the recording head 5 and the recording medium on the conveying belt 6 was 1 mm. On the other hand, the roll coater 9 was filled with a water-insoluble liquid. 10 sheets of 30 mm x 30 mm square solid images with maximum density on A4 size PPC paper ("V938" manufactured by Fuji Xerox Co., Ltd.) at a driving frequency of 20 kHz in a room temperature and humidity environment with a temperature of 20 ° C and a humidity of 65% Continuous printing. At this time, the conveyance speed of the recording medium was 847 mm / second.

  Further, the water-insoluble liquid is supplied to the surface of the upper transport roller 7 only in contact with the peripheral surface of the upper transport roller 7 except for the end in the length direction (that is, the solid image (recording portion of the recording medium). Only on the surface of the roller surface), and on the peripheral surfaces of both ends in the length direction of the upper conveying roller 7 (that is, on the surface of the roller contacting the non-recording portion (side edge portion) of the recording medium) The sex liquid was not supplied. More specifically, when an A4 size PPC paper having a width of 210 mm and a length of 297 mm is transported in the width direction, the upper transport rollers corresponding to 139 mm on the left and right from the center in the direction perpendicular to the transport direction (that is, the length direction). The water-insoluble liquid was supplied only to the surface portion of 7.

The presence or absence of the above solid image due to the recording liquid adhering to the surface of the upper conveying roller 7 and the presence or absence of the recording liquid adhering to the non-recording portion of the recording medium were visually confirmed and evaluated according to the following criteria. . The results are shown in Table 1.
○: There is no image disturbance and no recording liquid adheres to the non-recording part of the recording medium. X: There is an image disturbance and the recording liquid adheres to the non-recording part of the recording medium.

  In Table 1, “HFE7300” (boiling point: 98 ° C.) manufactured by Sumitomo 3M Limited was used as the hydrofluoroether.

  As is clear from Table 1, Examples 1 and 2 in which the SP value of the water-insoluble liquid and the SP value of the polymer constituting the surface of the upper conveying roller are both in the range of 6 to 11 have good image evaluation. On the other hand, the SP value of the polymer constituting the surface of the upper conveying roller is in the range of 6 to 11, but the water-insoluble liquid was not supplied to the roller. Comparative Example 1, the surface of the upper conveying roller The SP value of the polymer constituting the resin is in the range of 6 to 11, but the SP value of the water-insoluble liquid is not in the range of 6 to 11, and the SP value of the water-insoluble liquid is in the range of 6 to 11. However, Comparative Examples 3 and 4 in which the SP value of the polymer constituting the surface of the upper conveying roller was not in the range of 6 to 11 had poor image evaluation.

  Furthermore, using the upper transport roller whose surface is composed of other types of pigments, other types of water-insoluble liquids, and other types of polymers, a recording liquid is prepared in the same manner as described above, and the same evaluation is performed. The results were similar.

  As described above in detail with specific examples, the present invention is a high-speed process in an inkjet recording method and an inkjet recording apparatus in which a recording medium to which a recording liquid is attached and information is recorded is conveyed by a roller, The remarkable advantage is that it is possible to solve the problem that the aqueous recording liquid, which has been shortly lapsed after being attached to the recording medium and insufficiently dried, adheres to the non-recording portion of the roller or the recording medium and causes contamination. It is what you have.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 5 Recording head 6 Conveying belt 7 Upper side conveying roller 9 Roll coater (water-insoluble liquid supply means)
X recording medium

Claims (3)

An ink jet recording method comprising: a recording step of attaching a recording liquid to a recording medium; and a conveying step of conveying the recording medium to which the recording liquid is attached by a roller,
As the roller, a roller made of a material whose surface is excellent in water repellency is used, and
In the transfer step, the roller surface in contact with the portion of the recording medium on which recording liquid is adhered to supply non-aqueous liquid, the portion of the roller surface in contact with the portion of the recording medium on which the recording liquid is not attached is An ink jet recording method characterized by not supplying a water-insoluble liquid .   2. The ink jet recording method according to claim 1, wherein the material having excellent water repellency and the SP value of the water-insoluble liquid are both 6 to 11. An inkjet recording apparatus having a recording head for attaching a recording liquid to a recording medium, and a roller for conveying the recording medium to which the recording liquid is attached,
The surface of the roller is made of a material with excellent water repellency, and
Do not supply water-insoluble liquid to the part of the roller surface that comes into contact with the part of the recording medium to which the recording liquid is not attached, and water-insoluble to the roller surface that comes into contact with the part of the recording medium to which the recording liquid is attached . An ink jet recording apparatus comprising a supply means for supplying a liquid.

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