JP2006095998A - Ink-jet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink-jet recorder for performing a printing operation with inks of two-liquid and ultraviolet-curing type which enables a recording-head composition to be simplified and miniaturized while enabling the partial fall of printing dignity caused by an ununiform mixing to be prevented by sufficiently mixing and churning the two liquid. <P>SOLUTION: The ink-jet recorder 1 is equipped with a liquid mixing-churning section 51 for mixing and churning 1st and 2nd ink liquid fed to the recording head 9 and converting the mixture into an ultraviolet-curing ink in the ink course where the ink liquid is fed to the recording head 9 from each 1st and 2nd ink storage part 21, 22. Thereby, the printing dignity can be improved by mixing the two liquid uniformly, and the structure of the recording head 9 can be simplified and miniaturized. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus for recording an image such as a character or a graphic on a recording medium by using an ultraviolet curable ink generated by mixing two liquids of a first ink liquid and a second ink liquid. Is.

  An ink jet recording apparatus ejects ink (ink composition) droplets onto a recording medium such as paper by a recording head, and records images such as characters and graphics on the recording medium. Due to the finer droplets, high-resolution and high-quality images can be printed at high speed.

The ink used in such an ink jet recording apparatus is generally a so-called aqueous ink containing an aqueous solvent as a main component and containing a coloring component and a wetting agent such as glycerin for the purpose of preventing clogging.
However, when the recording medium is made of paper, cloth, or metal, plastic, or the like that does not allow water-based ink to permeate, general water-based inks have poor ink penetration and poor ink fixation. Therefore, stable printing cannot be performed.
Therefore, it has been proposed to use an ultraviolet curable ink containing a component that is polymerized by application of ultraviolet rays for printing on a recording medium in which aqueous ink does not penetrate or does not penetrate.

  As an ink jet recording apparatus that performs printing with ultraviolet curable ink, ultraviolet curable ink itself in which a colorant, an ultraviolet curable agent, a polymerization initiator, etc. are mixed at a predetermined ratio is initially stored in an ink storage unit. One-pack type was the mainstream. However, the ultraviolet curable ink mixed with a colorant, an ultraviolet curing agent, a polymerization initiator, etc., undergoes a polymerization reaction gradually during storage, so it is difficult to stably maintain the physical properties of the ink liquid such as viscosity, The change in the physical properties of the ink liquid may cause a decrease in printing performance.

Therefore, as an ink jet recording apparatus that performs printing with ultraviolet curable ink, in the apparatus, the ultraviolet curable ink includes a first ink liquid that is an ink composition including a colorant, and a reaction liquid that includes a polymerization initiator. It is stored separately in a form separated into two liquids with a second ink liquid that functions as a colorant, an ultraviolet curing agent, a polymerization initiator, etc. by contacting these two liquids on a recording medium. A two-component type has been proposed that exhibits a function as a mixed ultraviolet curable ink (see, for example, Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4).
Such a two-pack type can suppress changes in the physical properties of each ink liquid during storage and improve the storage stability of each ink liquid, so that stable printing performance can be maintained over a long period of time. Can do.

JP 2003-12971 A Japanese Patent No. 3478495 JP 2002-275403 A JP 2000-119574 A

However, in the conventional method in which the two liquids of the first ink liquid and the second ink liquid constituting the ultraviolet curable ink are mixed on the recording medium, an ejection control mechanism for ejecting fine ink droplets is provided for each ink. There is a problem that the configuration of the recording head in which the ejection control mechanism is incorporated becomes complicated and the size of the recording head increases.
In addition, each ink droplet ejected from the recording head is sprayed and applied so as to overlap at the same location on the recording medium, thereby contacting each other and becoming a mixed state. Therefore, it is difficult to achieve a uniform mixed state. Due to non-uniform mixing, there is a possibility that printing quality may be partially deteriorated, such as variation in curing reaction or uneven color.

  Accordingly, an object of the present invention is to solve the above-described problems, and is an ink jet recording apparatus that executes printing with a two-component type ultraviolet curable ink, and is intended to simplify and reduce the size of the recording head. In addition, the two liquids can be sufficiently mixed and stirred to prevent partial deterioration in print quality due to non-uniform mixing, and to achieve high-quality and stable printing without uneven printing It is to provide a recording device.

The above object is achieved by the following configuration.
(1) A first ink storage section storing a first ink liquid, and a second ink storage section storing a second ink liquid that generates ultraviolet curable ink by being mixed with the first ink liquid. A recording head that sprays and applies the first ink liquid and the second ink liquid onto a recording medium, an ink supply path that supplies the ink liquid from each ink reservoir to the recording head, and the recording head In an inkjet recording apparatus comprising ultraviolet irradiation means for irradiating ultraviolet rays onto the recording medium coated with ultraviolet curable ink,
The first ink liquid and the second ink liquid supplied to the recording head through the ink supply path are mixed and stirred at the connection portion between the recording head and the ink supply path, and converted into the ultraviolet curable ink. An ink jet recording apparatus comprising a liquid mixing and stirring unit.

(2) In the above (1), the liquid mixing and agitation unit includes a tank that stores the first ink liquid and the second ink liquid that are supplied from the ink storage units via the ink supply paths, and the tank. An ink jet recording apparatus comprising: a stirring blade that is rotatably mounted in the tank and that mixes and stirs the liquid supplied into the tank.
(3) The ink jet recording according to (1) or (2), wherein the first ink liquid contains a coloring material and a polymerization initiator, and the second ink liquid contains a polymerization compound and a polymerization accelerator. apparatus.
(4) (1) or (2), wherein the first ink liquid contains a coloring material and a polymerization compound, and the second ink liquid contains a polymerization compound, a polymerization initiator, and a polymerization accelerator. Inkjet recording apparatus.
(5) The first ink liquid includes a color material and a polymerization initiator, and the second ink liquid includes a polymerization compound, a polymerization initiator, and a polymerization accelerator (1) or (2) The ink jet recording apparatus described.

The ink jet recording apparatus according to the above (1) functions as a reaction liquid in which the ultraviolet curable ink includes the first ink liquid which is an ink composition including a colorant and a polymerization initiator. Since the ink is stored separately in a form separated into two liquids with the second ink liquid, each ink liquid has the advantage of a two-liquid type that can suppress changes in physical properties of each ink liquid during storage. Therefore, stable printing performance can be maintained over a long period of time.
In the ink jet recording apparatus described in the above (1), the ink liquids stored in the ink storage units independent from each other are mixed and stirred by the liquid mixing and stirring unit provided between the ink supply path and the recording head. Then, it is supplied to the recording head as one liquid of ultraviolet curable ink generated by mixing the two liquids.

  Therefore, although it is a two-component type, it is possible to simplify and miniaturize the configuration of the recording head by using a single ejection control mechanism incorporated in the recording head for controlling ejection of fine ink droplets.

  In addition, two liquids, a first ink liquid that is an ink composition containing a colorant and a second ink liquid that contains a polymerization initiator and functions as a reaction liquid, are sufficiently mixed and stirred by a liquid mixing and stirring unit. Compared with the conventional two-component type, which mixes the two liquids by contacting the ink liquids on the recording medium, the two liquids are sufficiently mixed and stirred, resulting in a printed product resulting from non-uniform mixing. Therefore, it is possible to realize high-quality and stable printing without printing unevenness.

  In the ink jet recording apparatus described in (2) above, the time required for uniform mixing can be adjusted by adjusting the rotation speed of the stirring blades, and the generation process of the ultraviolet curable ink by uniform mixing can be facilitated. .

A liquid containing a colorant and a polymerization initiator can be used as the first ink liquid, and a liquid containing a polymerization compound and a polymerization accelerator can be used as the second ink liquid.
In addition, a liquid containing a coloring material and a polymerization compound can be used as the first ink liquid, and a liquid containing a polymerization compound, a polymerization initiator, and a polymerization accelerator can be used as the second ink liquid.
In addition, a liquid containing a coloring material and a polymerization initiator can be used as the first ink liquid, and a liquid containing a polymerization compound, a polymerization initiator, and a polymerization accelerator can be used as the second ink liquid.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an ink jet recording apparatus according to the invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of a main part of an embodiment of an ink jet recording apparatus according to the present invention.
The ink jet recording apparatus 1 according to this embodiment is a two-component recording apparatus that performs desired printing with ultraviolet curable ink. The inkjet recording apparatus 1 stores a first ink storage unit 21 that stores a first ink liquid, and a second ink liquid that generates an ultraviolet curable ink by being mixed with the first ink liquid. A recording head 9 for spraying and applying a first ink liquid and a second ink liquid onto a recording medium 7 such as paper, a recording head 9, and a main scanning direction (recording) indicated by an arrow B; A carriage 11 that is driven back and forth in the width direction of the medium 7, a recording medium transport mechanism 13 that transports the recording medium 7 in the sub-scanning direction orthogonal to the main scanning direction, and the ink storage units 21 and 22 to the recording head 9. An ink supply path 15 for supplying ink liquid and an ultraviolet irradiation means (not shown) for irradiating ultraviolet rays onto the recording medium 7 coated with ultraviolet curable ink by the recording head 9 are provided.

  In the case of the present embodiment, the first ink liquid is an ink composition containing at least a polymerization initiator or a polymerization compound and a colorant, and the second ink liquid contains a polymerization initiator or a polymerization compound and a polymerization accelerator. When mixed with one ink liquid, it functions as a reaction liquid that initiates curing of the ink liquid by a polymerization reaction of the resin material.

  Specifically, various combinations of the component compositions of the first ink liquid and the second ink liquid are conceivable as shown in Table 1 below.

  A pigment can be used as the color material of the first ink liquid. Further, both the first ink liquid and the second ink liquid are prepared as a solvent-free system containing no solvent.

  As the recording medium 7, various materials such as paper, cloth, or a metal, plastic, or the like that does not penetrate water-based ink can be used as long as it is a sheet that can be conveyed by the recording medium conveyance mechanism 13. is there.

The carriage 11 is supported by a guide shaft 25 so as to be movable in the main scanning direction B, and is moved and scanned to an arbitrary position in the main scanning direction by a driving belt 29 driven to reciprocate by a transport motor 27.
The recording medium transport mechanism 13 feeds the recording medium 7 in the sub-scanning direction by the rotation of the cylindrical platen 13 a that contacts the surface of the recording medium 7.
The feeding operation of the recording medium 7 by the recording medium transport mechanism 13 is controlled in synchronization with the reciprocating operation of the carriage 11.

  At the standby position of the carriage 11 (in the vicinity of the right-hand side wall as viewed from the front), the head cleaning means 31 for eliminating clogging of the ink discharge ports of the recording head 9 and the ink discharge ports of the recording head 9 are covered. A cap member 33 for preventing the ink discharge port from being dried is provided.

  The 1st ink storage part 21 and the 2nd ink storage part 22 function as a main tank which stores each ink liquid by the predetermined pressurization condition. In the present embodiment, the first ink and the second ink delivered from the first ink reservoir 21 and the second ink reservoir 22 are respectively passed through the first ink supply tube 41 and the second ink supply tube 42. It is supplied to the liquid mixing and stirring unit 51.

  The liquid mixing and stirring unit 51 mixes and stirs the first ink and the second ink supplied via the first ink supply tube 41 and the second ink supply tube 42 to generate a one-component ultraviolet curable ink. It is a stirring member.

  Specifically, as shown in FIG. 2, the liquid mixing and agitation unit 51 includes a first ink liquid and a second ink liquid supplied from the ink storage units 21 and 22 via the ink supply paths 41 and 43. And a stirring blade 55 that is rotatably disposed in the tank 53 and that mixes and stirs the liquid supplied into the tank 53. The stirring blade 55 is rotated by a motor (not shown).

  The first ink and the second ink are temporarily stored in the tank 53 and mixed and stirred by the stirring blade 55, so that at least a polymerization initiator and a polymerization compound are mixed at a predetermined ratio. UV curable ink. This ink can be cured by being irradiated with ultraviolet rays. It is preferable that the ink is supplied from the ink storage units 21 and 22 into the tank 53 by the required amount of ink ejected from the recording head 9.

  The one-component ultraviolet curable ink generated by mixing in the liquid mixing and stirring unit 51 is supplied to the recording head 9 provided in the carriage 11 through the ink supply path 15. Then, the recording head 9 discharges this one-component ultraviolet curable ink onto the recording medium 7 and lands on the recording medium. The ink suitable for landing on the recording medium is cured by being irradiated with ultraviolet rays by an ultraviolet irradiation means (not shown) and fixed on the recording medium. As a result, an image is formed on the recording medium.

  In the inkjet recording apparatus 1 described above, in the apparatus, the ultraviolet curable ink is used as a reaction liquid containing a first ink liquid that is an ink composition containing a colorant and a polymerization initiator. Because it is stored separately in two liquids with the ink liquid, it has the advantage of the two liquid type that can suppress changes in the physical properties of each ink liquid during storage, and storage of each ink liquid Since the stability is improved, stable printing performance can be maintained over a long period of time.

In the ink jet recording apparatus 1 described above, the ink liquids stored in the ink storage units 21 and 22 that are independent from each other are transferred to the first ink supply tube 41, the second ink supply tube 42, the ink supply path 15, and the like. Are mixed and agitated by the liquid mixing and agitation unit 51 installed between the two and supplied to the recording head 9 as one liquid of ultraviolet curable ink generated by mixing the two liquids.
Therefore, it is possible to simplify and miniaturize the configuration of the recording head 9 by using a single ejection control mechanism incorporated in the recording head 9 for the ejection control of fine ink droplets even though it is a two-component type.

  Also, the two liquids, the first ink liquid that is an ink composition containing a colorant and the second ink liquid that contains a polymerization initiator and functions as a reaction liquid, are sufficiently mixed by the liquid mixing and stirring unit 51. Since the agitation can be performed, compared with the conventional two-component type in which the two liquids are mixed by mutual contact on the recording medium 7, the two liquids are sufficiently mixed and agitated, resulting in non-uniform mixing. Thus, it is possible to prevent a partial drop in the print quality and to realize high-quality and stable printing without printing unevenness.

  Furthermore, in the ink jet recording apparatus 1 shown in the present embodiment, the time required for uniform mixing can be adjusted by adjusting the rotation speed of the stirring blade 55, and the process of generating UV-curable ink by uniform mixing is facilitated. can do.

1 is a perspective view showing a schematic configuration of an embodiment of an ink jet recording apparatus according to the present invention. FIG. 2 is a horizontal cross-sectional view of the liquid mixing and stirring unit shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 3 1st ink storage part 5 2nd ink storage part 7 Recording medium 9 Recording head 11 Carriage 13 Recording medium conveyance mechanism 15 Ink supply path 41 1st ink supply path 43 2nd ink supply path 51 Liquid mixing stirring part 53 Tank 55 Stirring blade

Claims (5)

A first ink reservoir that stores the first ink liquid;
A second ink storage section storing a second ink liquid that generates ultraviolet curable ink by being mixed with the first ink liquid;
A recording head for discharging the first ink liquid and the second ink liquid onto a recording medium;
An ink supply path for supplying ink liquid from each ink reservoir to the recording head;
An inkjet recording apparatus comprising: an ultraviolet irradiation unit configured to irradiate ultraviolet rays onto the recording medium on which the ultraviolet curable ink is applied by the recording head;
An ink jet recording apparatus comprising: a liquid mixing and stirring unit that mixes and stirs the first ink liquid and the second ink liquid to generate the ultraviolet curable ink in the ink supply path.   The liquid mixing and agitation unit includes a tank for storing a first ink liquid and a second ink liquid supplied from each ink storage unit via each ink supply path, and a tank that is rotatably mounted in the tank. The inkjet recording apparatus according to claim 1, further comprising a stirring blade that mixes and stirs the liquid supplied therein.   3. The ink jet recording apparatus according to claim 1, wherein the first ink liquid includes a color material and a polymerization initiator, and the second ink liquid includes a polymerization compound and a polymerization accelerator.   3. The ink jet recording apparatus according to claim 1, wherein the first ink liquid includes a color material and a polymerization compound, and the second ink liquid includes a polymerization compound, a polymerization initiator, and a polymerization accelerator. 3. The ink jet recording apparatus according to claim 1, wherein the first ink liquid includes a color material and a polymerization initiator, and the second ink liquid includes a polymerization compound, a polymerization initiator, and a polymerization accelerator. .

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