JP2008101043A - Ink composition for borderless printing, and inkjet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition capable of maintaining the excellent accumulation-preventing effects in a catching member for a long period in borderless printing by an inkjet printer; and to provide an inkjet printer having the ink composition and the catching member. <P>SOLUTION: The ink composition contains a metal complex of a biuret compound represented by general formula (1) (wherein, R<SP>1</SP>and R<SP>2</SP>are each independently a hydrogen atom or a 1-4C alkyl group) and a copper ion. The inkjet printer includes the ink composition and the catching member. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink composition for borderless printing and an ink jet printer. According to the present invention, in the borderless printing by the ink jet recording method, the state of the capturing member that captures the ink droplets ejected to the region other than the recording medium can be maintained in a good state for a long period of time.

  In the ink jet recording system, borderless printing similar to silver salt photography is performed. In borderless printing, it is necessary to leave the entire surface as an image area without leaving any non-image area (margin) at the edge of the recording medium. Therefore, by properly ejecting ink droplets from the printer head from the surface of the recording medium to the outside of the edge, it is possible to form an appropriate image up to the edge of the recording medium. Thus, the principle of borderless printing that has been conventionally performed will be described below with reference to the accompanying drawings.

  First, the principle of borderless printing is schematically shown in FIGS. FIG. 1 is an enlarged perspective view of a main part schematically showing a borderless printing process by the ink jet recording method, and FIG. 1A shows a state in which the front edge of the recording medium is printed. FIG. 1B shows a state where the recording medium side edge is printed, and FIG. 1C shows a state where the recording medium rear edge is printed. FIG. 2 is a schematic side view of the main part in the state of FIG.

  As shown in FIGS. 1 and 2, the ink jet recording apparatus 10 includes a carriage 14 that reciprocates along a guide shaft 12 that extends in the main scanning direction (that is, the width direction of the recording paper 11; the direction of arrow B in FIG. 1). And a platen (not shown) arranged to face the lower side of the recording head 13, and the recording paper 11 is provided between the recording head 13 and the platen. Then, it is conveyed in the sub-scanning direction (the direction of arrow A in FIGS. 1 and 2) by a paper feeding means (not shown).

  When the front edge portion 11a of the recording paper 11 is conveyed to below the recording head 13, printing of the front edge portion 11a is started as shown in FIGS. That is, the recording head 13 starts printing by ejecting ink droplets 19 toward the recording paper 11 while reciprocating along the guide shaft 12 in the main scanning direction (arrow B direction). At this time, in order to execute printing without leaving a margin on the front edge portion 11 a of the recording paper 11, the ink droplets 19 are also ejected outside the front edge portion 11 a of the recording paper 11. The ink droplets 19 ejected to the outside of the recording paper 11 directly adhere to the capturing member 30 provided on the platen and further penetrate into the capturing member 30 to form an ink liquid capturing region 31.

  When the printing of the front edge portion 11a of the recording paper 11 is completed, the recording paper 11 is conveyed in the sub-scanning direction (arrow A direction), and the central portion of the recording paper 11 is printed. In printing at the center, in order to execute printing without leaving margins on the side edges 11b on both sides of the recording paper 11, the outer side of the side edge 11b of the recording paper 11 as shown in FIG. Ink droplets 19 are also ejected, and the ink droplets 19 ejected to the outside in this way are directly attached to and captured by the capturing member 30 provided on the platen. Further, when printing of the central portion of the recording paper 11 is completed, the recording paper 11 is conveyed in the sub-scanning direction (arrow A direction), and printing of the trailing edge portion 11c of the recording paper 11 is performed. As shown in FIG. 1C, in order to perform printing without leaving a margin on the trailing edge portion 11c of the recording paper 11 in the printing of the trailing edge portion 11c, the outer side of the trailing edge portion 11c of the recording paper 11 is printed. Ink droplets 19 are also ejected, and the ink droplets 19 are directly attached to and captured by the capturing member 30 provided on the platen.

As shown in FIGS. 1 and 2, in order to perform borderless printing, ink droplets 19 are also ejected to the outside of the recording paper 11. Therefore, it is necessary to provide a capturing member on the platen for the purpose of preventing the ink droplets 19 ejected outside the recording paper 11 from soiling the back surface of the recording paper 11 and the like. A typical ink jet recording apparatus in which such a capturing member is provided on a platen is shown in FIGS.
FIG. 3 is a perspective view of a typical ink jet recording apparatus 10 </ b> A, in which the case cover 1 is opened to particularly show the printing mechanism. In the printing mechanism section, a carriage 4 on which the ink cartridges 2 and 3 and the recording head 4A are mounted, and a platen 5 are arranged at a position facing the moving path, and further, a platen 5 is sandwiched between the platen 5 and the recording paper. A first paper pressing roller 6 is disposed on the upstream side in the discharging direction, and a second paper pressing roller 7 is disposed on the downstream side. 4 is a partial plan view of the printing mechanism unit of the inkjet recording apparatus 10 shown in FIG. 3, and FIG. 5 is a partial sectional view of the printing mechanism unit of the inkjet recording apparatus 10 shown in FIG.

  In particular, as shown in FIGS. 4 and 5, platen openings 5 a, 5 b, 5 c are provided in a part of the platen 5, and a capturing member 20 is disposed in the lower part of the platen 5. The platen opening 5a is a window for directly capturing on the capturing member 20 without causing ink droplets to adhere to the surface of the platen 5 or generating ink mist when the front edge of the recording paper P is printed. The platen opening 5b and the platen opening 5c are windows used for printing the side edge and the rear edge of the recording paper P, respectively. That is, all of the ink droplets ejected from the recording head 4A to the outside of the recording paper P pass through the platen openings 5a, 5b, 5c and are directly captured by the capturing member 20. . Note that the back surface of the recording paper P is conveyed while being in contact with the front surface of the platen 5, and the capturing member 20 is disposed at such a height that the back surface of the recording paper P does not contact the upper surface of the capturing member 20. There is a need.

As shown in FIG. 5, the capture member 20 is carried by the support member 8. Further, the support member 8 is provided with a support member opening 8a, and a waste ink tank is provided below the support member. 9 is provided, the ink liquid temporarily captured by the capturing member 20 is gradually guided to the waste ink tank 9 from the support member opening 8a, and the absorption normally provided in the waste ink tank 9 is provided. It is absorbed and held by the holding material.
In this specification, “downward” or “upper” with respect to the printer means downward or upward in the direction of gravity in a state where printing is being performed by the printer.

  Recently, pigment inks have been adopted mainly for the purpose of improving the storage stability of printed matter. Since the capturing member as described above is usually made of a porous material (for example, urethane foam or sintered porous plastic), particularly in the case of pigment ink, only the solvent component penetrates into the interior, and the pigment The particles tend to remain on the surface of the porous capture member and accumulate. As pigment particle deposition grows gradually on the surface of the porous capture member and protrudes above the platen opening, the pigment particles adhere to the back surface of the recording paper, and further, from the back surface of the recording paper to the platen surface. After being transferred, the back surface of another recording sheet is stained.

  Such a technique for preventing the deposition of pigment particles has been proposed mainly for water-based inks. For example, a technique for impregnating the trapping member with an organic solvent is known (Patent Document 1). ). A technique of impregnating an organic solvent selected corresponding to the color type of pigment ink is also known (Patent Document 2).

JP 2003-191545 A JP 2004-174978 A

However, in borderless printing by an ink jet printer, the pigment particle deposition preventing effect is gradually reduced by simply impregnating the trapping member with a compound having a deposition preventing effect (that is, an impregnating agent). This is because ink droplets are ejected one after another to the capturing member and penetrate into the capturing member, so that the impregnating agent is gradually washed away from the capturing member as the ink liquid penetrates and the carrying amount decreases. It is.
In order to prevent such an outflow of the impregnating agent and maintain the deposition preventing effect in the capturing member for a long period of time, it is necessary to include the impregnating agent in the ink composition. In this case, the impregnating agent contained in the ink composition should not adversely affect the ink suitability of the ink composition.
For example, since urea has an excellent anti-deposition effect, it can be used as an impregnating agent that is previously supported on the capturing member. However, when urea is added to the ink composition, it decomposes, so that the storage stability of the ink is increased. There was a problem.
In addition, a burette, which is a kind of urea derivative, has an excellent anti-deposition effect and is superior in that it does not degrade even when added to the ink composition, and does not impair the storage stability of the ink. However, since the solubility in ink is at most 2%, the use and effects may be limited.
As a result of intensive research on borderless printing by an ink jet printer that does not exhibit the above-mentioned drawbacks, the present inventor has an excellent deposition preventing effect in a trapping member when a specific burette compound is added in the form of a metal complex. It was found that even when added to the ink composition, the storage stability of the ink is not adversely affected, and the solubility in the ink is dramatically improved.
The present invention is based on these findings.

（式中、Ｒ^１及びＲ^２は、それぞれ独立に、水素原子又は炭素原子数１〜４のアルキル基である）
で表されるビューレット化合物と銅イオンとの金属錯体を含むことを特徴とする、インクジェット記録方法による縁無印刷用のインク組成物に関する。
本発明の好ましい態様によれば、前記ビューレット化合物が、Ｒ^１及びＲ^２がそれぞれ水素原子である前記一般式（１）で表されるビューレット化合物である。
本発明の別の好ましい態様によれば、水系顔料インク組成物である。 Therefore, the present invention relates to the general formula (1):

(Wherein, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms)
It is related with the ink composition for borderless printing by the inkjet recording method characterized by including the metal complex of the burette compound represented by these, and a copper ion.
According to a preferred aspect of the present invention, the burette compound is a burette compound represented by the general formula (1) in which R ¹ and R ² are each a hydrogen atom.
According to another preferred embodiment of the present invention, it is a water-based pigment ink composition.

Further, the present invention provides a capturing member that directly captures ink droplets ejected from a region other than the recording medium among ink droplets ejected from an inkjet recording printer head;
The present invention also relates to an ink jet printer comprising the ink composition.
In a preferred aspect of the ink jet printer according to the present invention, the capturing member is a porous plastic produced by sintering and molding plastic particles, a plastic foam sheet or a perforated sheet, or a sheet of fibrous material. .
In another preferred embodiment of the ink jet printer according to the present invention, the plastic particles are polyolefin resin, vinyl resin, polyester resin, polyamide resin, polystyrene resin, acrylic resin, polysulfone resin, polyethersulfone resin, Polyethylene sulfide resin, fluorine resin, or crosslinked polyolefin resin particles, or a mixture of these particles.
In still another preferred embodiment of the ink jet printer according to the present invention, the capturing member is impregnated with the burette compound represented by the general formula (1).

  According to the present invention, the buret compound having an excellent anti-deposition effect is replenished to the capturing member one after another from the ink composition in borderless printing by an ink jet printer, so that the anti-deposition effect is maintained for a long time. In addition, the ink suitability of the ink composition is not adversely affected. Further, since the solubility in ink is high, the use and effects are not limited.

  The ink composition for an inkjet recording method according to the present invention contains a complex of a burette compound represented by the general formula (1) and a copper ion. In the present specification, the alkyl group having 1 to 4 carbon atoms includes a linear or branched alkyl group, and specifically includes a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n- A butyl group, i-butyl group, sec-butyl group, or t-butyl group can be mentioned.

The burette compound represented by the general formula (1) is, for example, a compound (burette) in which R ¹ and R ² are each a hydrogen atom, or ^one of R ¹ and R ² is a hydrogen atom. Yes, there can be mentioned compounds in which the other of R ¹ and R ² is an alkyl group having 1 to 4 carbon atoms.

  In the ink composition of the present invention, it is preferable that a complex is formed from the burette compound and copper ions, and the obtained complex is added to the ink composition.

  In the ink composition for an ink jet recording method according to the present invention, the metal complex of the burette compound represented by the general formula (1) and the copper ion is preferably 1 to 10 weights with respect to the total weight of the ink composition. %, More preferably 2-5% by weight. By making the content of the metal complex 2% by weight or more, it is possible to effectively maintain the anti-deposition effect on the capturing member, and by making it 5% by weight or less, there is no adverse effect on the storage stability of the ink. be able to.

  The metal complex of the burette compound represented by the general formula (1) and copper ions is preferably not only contained in the ink composition but also impregnated in the capturing member in advance. This is to compensate for the initial anti-deposition effect on the capture member. Therefore, a metal complex different from the metal complex to be contained in the ink composition can be used as the metal complex to be impregnated in the capturing member in advance. Alternatively, a compound (impregnating agent) completely different from the metal complex, for example, a burette compound represented by the general formula (1) may be used.

  The ink composition of the present invention can be waterless or nonaqueous for borderless printing by the ink jet recording method, but is preferably aqueous. Also, as the colorant, either a dye or a pigment can be used, but it can be suitably used for a pigment ink composition in which deposition is likely to occur.

The ink composition of the present invention constitutes a conventionally known ink composition for an ink jet recording method except that it contains a metal complex of a burette compound represented by the general formula (1) and a copper ion. It can contain ingredients.

  The ink composition of the present invention is used as an ink composition that may be directly ejected to a capturing member in borderless printing by an inkjet recording method. In this specification, the “capturing member” is used as a member for directly landing and capturing the ink droplets ejected from the ink jet recording printer head to an area other than the recording medium. For the same purpose, it has been conventionally used as an “ink absorbing material” in an ink jet recording printer. The “region other than the recording medium” is an arbitrary region that ejects ink droplets other than the surface of the recording medium, and is typically an outer region adjacent to the periphery of the recording medium at the time of borderless printing, Further, it includes a discharge area for the printer head cleaning process. The cleaning process is a process performed for the purpose of avoiding defective ejection of the printer head by forcibly passing and ejecting the ink composition to the printer head at a predetermined home position where the recording medium is not conveyed. The capture member can also be provided at this home position.

  The capture member used in the present invention needs to land and receive ink droplets ejected from the ink head directly and capture them completely, as in the case of the same type of conventional capture member. For example, during borderless printing, if ink droplets ejected to the outer area of the recording medium are not completely captured and float in a mist state at the periphery of the recording medium, the recorded image and recording medium are contaminated. Further, the recording medium contact surface of the platen surface may be contaminated. In addition, when the ink liquid is captured by the capturing member, even if the printer is rotated about 90 ° when changing the printer installation location, etc., it has a holding ability that does not leak the ink liquid Is preferred. Furthermore, the capturing member needs to move the captured ink liquid sequentially to the waste ink tank and maintain the acceptability for capturing the next ink droplet.

The capturing member used in the present invention can be prepared from any material having the above-mentioned functions, and is preferably made of a porous material that has been conventionally used as a capturing member. More preferably, it is made of a continuous porous material in communication.
As the porous material, for example, a plastic foam sheet or a porous sheet, or a sheet of a fibrous material (for example, a web, a net, a woven fabric, a knitted fabric, or a non-woven fabric) can be used. Examples of the plastic foam include polyurethane foam, polyvinyl alcohol (PVA) sponge, and a fluororesin porous body.

  The capturing member used in the present invention may have a single layer structure or a multilayer structure of two or more layers. When it consists of two layers, it is preferable to consist of an ink receiving layer and an ink diffusion layer. The ink receiving layer is a layer for directly landing and capturing ink droplets ejected from a printer head, and the ink diffusion layer holds a waste ink tank while holding the ink liquid captured by the ink receiving layer. It is a layer to move to. More preferably, at least a part of the ink receiving layer and the ink diffusion layer are brought into contact with each other, and a material having higher ink absorbability than the ink receiving layer is used for the ink diffusion layer. Further, each of the ink receiving layer and the ink diffusion layer can have a multilayer structure of two or more layers.

  Examples of the combination of the ink receiving layer and the ink diffusion layer include, for example, a network sheet made of a polymer compound having water repellency (for example, a fluororesin), a porous sheet made of a hydrophilic polymer compound, and a felt material. Or a combination of a polyurethane foam sheet and a PVA sponge sheet.

The capturing member used in the present invention may be a porous plastic produced by sintering and molding plastic particles. As the plastic particles, thermoplastic plastic particles can be used. For example, polyolefin resins (for example, ultra high molecular weight polyethylene, polyethylene such as high density polyethylene and polypropylene), vinyl resins (for example, polyvinyl chloride resin), polyester resins (for example, polyarylate), polyamide resins, polystyrene Particles of resin, acrylic resin, polysulfone resin, polyethersulfone resin, polyethylene sulfide resin, fluorine resin, or cross-linked polyolefin resin, or a mixture of these particles can be used.

  Examples of the fluororesin include polytetrafluoroethylene, polyfluoroacryl acrylate, polyvinylidene fluoride, polyvinyl fluoride, and hexafluoropropylene.

  The crosslinked polyolefin resin material is a low density polyethylene, a medium density polyethylene, or a polyethylene resin such as high density polyethylene or a polyolefin resin such as polypropylene, which is crosslinked by irradiating ionizing radiation such as γ rays or X rays, Alternatively, an inorganic compound such as aluminum chloride or nitrogen fluoride as a crosslinking agent, t-butyl-cumyl-peroxide, dicumyl-peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane Or chemically crosslinked using an organic peroxide such as acetylene peroxide.

  The average particle size of the plastic particles is not particularly limited, but is preferably 1,000 μm or less, for example. Also, the melt flow rate (MFR) is not particularly limited. For example, when a material of 0.01 or less is used, it is preferable in that a sintered porous plastic having a uniform pore diameter can be obtained. is there.

  The porous plastic used in the present invention can be produced by sintering and molding the thermoplastic particles by a static molding method or a dynamic molding method.

  The static molding method is a so-called in-mold sintering method, for example, a method in which thermoplastic particles are filled in a cavity formed in a gap portion of the molding die and then heated together with the molding die. .

  As the dynamic molding method described above, (1) a ram that uses a ram type extruder having a molding die at the tip and incorporating a piston (plunger) that reciprocates in a temperature adjustable cylinder. Extrusion method, (2) An injection molding method using an injection molding machine having a mold at the tip and a screw capable of being adjusted in temperature, (3) A mold at the tip, Extrusion method using an extruder with a screw incorporated in a temperature-adjustable cylinder, (4) Using a mold consisting of a female mold and a male mold inserted into the inner diameter portion of the female mold, (5) Consists of a pair of upper and lower movable belts or a lower movable belt at the tip, with a raw material filled in the cavity formed in the mold and then heated using a compression molding machine. A temperature-adjustable cylinder with a molded mold Continuous pressing method carried out using a continuous press for extruding the raw material into the mold within the like.

  From these methods such as static molding and dynamic molding, an appropriate method can be appropriately selected according to the final shape and physical properties of the porous plastic used in the present invention.

  The sintered porous plastic molded body (molded plate) obtained in this way looks like a normal plastic molded body (molded plate) in appearance, but in fact, it is innumerable interconnected in multiple directions. It has a hole. The sintered porous plastic molded body is commercially available, and molded bodies (molded plates) having various pore diameters can be easily obtained [for example, Porex Technologies (Porex Technologies, Inc.). ); Fieldus (Mitsubishi Plastics)].

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

<Example 1>
(1) Synthesis of Dispersing Resin A After replacing a reactor equipped with a stirrer, a thermometer, a reflux tube and a dropping funnel with nitrogen, styrene 25 g, n-dodecyl methacrylate 30 g, methoxypolyethylene glycol methacrylate 20 g, butyl methacrylate 16 g, and methacryl The acid 9.5g was melt | dissolved in methyl ethyl ketone 100g, and nitrogen gas substitution was performed.
The same monomer mixture / methyl ethyl ketone solution was also added to the dropping funnel, and 0.2 g of 2,2′-azobis (2,4-isomethylvaleronitrile) was further added to perform nitrogen gas replacement.
In a nitrogen atmosphere, the polymerization reaction was carried out while heating to 65 ° C. and adding the dropping funnel solution over 3 hours. The obtained copolymer solution was purified by repeated drying under reduced pressure, dissolution with methyl ethyl ketone and filtration, and then diluted by adding methyl ethyl ketone so that the solid content of the resin was 50% by weight. A resin solution of Dispersing Resin A having an acid value of about 70 KOH mg / g and an average molecular weight of 50,000 was obtained.

(2) Preparation of Dispersion A Organic pigment C.I. I. Pigment Red 122 (200 g) was used, and this was mixed and stirred with the resin solution A (100 g) prepared in the preceding item (1) to prepare a slurry. To this slurry, 38 g of a 10 wt% aqueous potassium hydroxide solution was added and dispersed with an ultra-high pressure homogenizer.
Subsequently, this dispersion is gradually added to 400 g of pure water under stirring, and further, all of methyl ethyl ketone and a part of water are removed at 60 ° C. under reduced pressure, so that the pigment concentration becomes 15% by weight. To this, ultrapure water was added to obtain a dispersion A.

(3) Preparation of burette-copper complex Cupric chloride (5 g) is dissolved in ion-exchanged water (35 g) at pH 6.5. Subsequently, burette (7.6 g) was added and stirred, and then stirred while gradually dropping sodium hydroxide and ion-exchanged water, thereby pH 9 burette-copper complex aqueous solution (50 g “active ingredient 20%”). Got.

(4) Preparation of ink composition A Dispersion A (60 g) prepared in the previous section (2), Burette-copper complex aqueous solution (25 g) prepared in the previous section (3), Surfynol which is an acetylene glycol surfactant 104 (0.2 g) and Surfynol 465 (1 g) (both Surfynol are trade names; manufactured by Air Products and Chemicals Inc.), triethylene glycol monoethyl ether (2 g), 1,2-hexane Diol (2 g), triethanolamine (1 g), glycerin (12 g), 2-pyrrolidone (2 g), and ultrapure water were further added and stirred for 2 hours with a total amount of 100 g, followed by a membrane filter having a pore size of about 1.2 μm ( A water-based ink composition A was prepared by filtration using a product name (manufactured by Nippon Millipore Limited).

<Comparative Example 1>
Ink composition B was prepared.
Specifically, dispersion A (60 g) prepared in Example 1 (2), burette (5 g), Surfynol 104 (0.2 g), which is an acetylene glycol surfactant, and Surfynol 465 (1 g) (Two types of Surfinol are trade names; Air Product
ts and Chemicals. Inc. Co., Ltd.), triethylene glycol monoethyl ether (2 g), 1,2-hexanediol (2 g), triethanolamine (1 g), glycerin (12 g), 2-pyrrolidone (2 g) and ultrapure water. After stirring for 2 hours with a total amount of 100 g, aqueous ink composition B was prepared by filtering through a membrane filter (trade name; manufactured by Nihon Millipore Limited) having a pore size of about 1.2 μm. After 3 days, burette (about 3.5 g) that could not be dissolved was filtered off on a membrane filter. Each evaluation was carried out as it was.

<Comparative example 2>
Ink composition C was prepared.
Specifically, dispersion A (60 g) prepared in Example 1 (2), urea (5 g), olphine E1010 (1 g) which is an acetylene glycol surfactant (trade name; manufactured by Nissin Chemical Industry Co., Ltd.) ), Triethylene glycol monoethyl ether (2 g), 1,2-hexanediol (2 g), triethanolamine (1 g), triethylene glycol (12 g), 2-pyrrolidone (2 g) and ultrapure water. After stirring for 2 hours with a total amount of 100 g, aqueous ink composition C was prepared by filtration through a membrane filter (trade name; manufactured by Nippon Millipore Limited) having a pore size of about 1.2 μm.

[Evaluation of the physical properties]
(1) Storage stability The aqueous ink compositions prepared in Example 1 and Comparative Examples 1 and 2 were allowed to stand at 70 ° C. for 10 days, and the viscosities immediately after the ink preparation and the viscosities after being left were compared. The judgment criteria are as follows. The results are shown in Table 1.
Judgment A: The fluctuation range is less than ± 5% B: The fluctuation range is ± 5% or more and less than ± 10% C: The fluctuation range is ± 10% or more

(2) Deposition evaluation on foamed polyurethane The aqueous ink compositions prepared in Example 1 and Comparative Examples 1 and 2 were set in an ink jet printer (PX-V630; Seiko Epson Corporation), and continuous printing without border printing was performed. It was carried out to evaluate the state of ink deposition on the capture member of the platen part. As the capturing member, a polyurethane foam capturing member was used.
The evaluation was carried out by continuously performing borderless printing on the postcard paper for ink jet printing in an environment of 40 ° C. and 15% relative humidity, and the number of printing (number of sheets) until the back surface smearing was examined. The occurrence of smearing on the back surface was determined by visual inspection of the postcard paper after printing. The results are shown in Table 1.
Judgment A: Back surface smear does not occur even if 500 sheets or more are printed.
B: Back surface contamination does not occur at 200 or more and less than 500.
However, if the number of sheets exceeding 500 is printed, the back surface is stained.
C: Back surface smear occurs when printing is less than 200 sheets.

(3) Evaluation of deposition on porous plastic The capturing member of the platen part was changed to a capturing member made of porous plastic, and the deposition state was evaluated in the same manner as in (2) above.
The porous plastic was prepared by the following method. That is, a polymer polyethylene having an average particle diameter of 150 μm and a melt flow rate (MFR) of 0.01 or less is molded into a rectangular cross section so that the layer thickness ratio is 70% of the total thickness of the final filter. The gap between the molds was filled and heated at a temperature of 160 to 220 ° C. for 30 minutes to obtain a porous plastic capturing member.
The aqueous ink composition prepared in Example 1 and Comparative Examples 1 and 2 was set in an ink jet printer (PX-V630; Seiko Epson Corporation), and borderless printing was continuously performed to the platen portion capturing member. The ink deposition status of the ink was evaluated. In addition, the said porous plastic was used as a capture member of a platen part.
The evaluation was carried out by continuously performing borderless printing on the postcard paper for ink jet printing in an environment of 40 ° C. and 15% relative humidity, and the number of printing (number of sheets) until the back surface smearing was examined. The occurrence of smearing on the back surface was determined by visual inspection of the postcard paper after printing. The results are shown in Table 1.
Judgment A: Back surface smear does not occur even if 500 sheets or more are printed.
B: Back surface contamination does not occur at 200 or more and less than 500.
However, if the number of sheets exceeding 500 is printed, the back surface is stained.
C: Back surface smear occurs when printing is less than 200 sheets.

(4) Results

  According to the ink composition of the present invention, a burette compound having an excellent anti-deposition effect can be contained in the ink composition in the form of a metal complex, and it can be replenished to the capturing member one after another from the ink composition. Therefore, it is possible to maintain an excellent anti-deposition effect for a long time in borderless printing by an ink jet printer. In particular, it can be effectively used in borderless printing by an ink jet printer using a pigment ink composition.

It is a principal part expansion perspective view which shows typically the borderless printing process by an inkjet recording system. It is a typical principal part side view of the state of FIG. 1 (A). 1 is a perspective view of a typical ink jet recording apparatus. FIG. 4 is a partial plan view of a printing mechanism unit of the ink jet recording apparatus shown in FIG. 3. It is a fragmentary sectional view of the printing mechanism part of the inkjet recording device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Case cover; 2, 3 ... Ink cartridge; 4 ... Carriage;
4A: recording head; 5 ... platen; 5a, 5b, 5c ... platen opening;
6 ... 1st paper presser roller; 7 ... 2nd paper presser roller;
DESCRIPTION OF SYMBOLS 8 ... Support member; 8a ... Support member opening part 9 ... Waste ink tank; 10, 10A ... Inkjet recording device;
DESCRIPTION OF SYMBOLS 11 ... Recording paper; 11a ... Front edge part of recording paper; 11b ... Side edge part of recording paper; 11c ... Rear edge part of recording paper; 12 ... Guide shaft; -Recording head;
14 ... carriage; 19 ... ink drop; 20 ... catching member;
30 ... Capture member; 31 ... Ink liquid capture region.

Claims (7)

General formula (1):

(Wherein, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms)
An ink composition for borderless printing by an ink jet recording method, comprising a metal complex of a burette compound represented by formula (I) and a copper ion. The ink composition according to claim 1, wherein the burette compound is a burette compound represented by the general formula (1) in which R ¹ and R ² are each a hydrogen atom.   The ink composition according to claim 1, which is a water-based pigment ink composition. A capturing member that directly captures ink droplets ejected to a region other than the recording medium among ink droplets ejected from the inkjet recording printer head;
An ink jet printer comprising the ink composition according to any one of claims 1 to 3.   The inkjet printer according to claim 4, wherein the capturing member is a porous plastic produced by sintering and molding plastic particles, a plastic foam sheet or porous sheet, or a sheet of fibrous material.   The plastic particles are polyolefin resin, vinyl resin, polyester resin, polyamide resin, polystyrene resin, acrylic resin, polysulfone resin, polyethersulfone resin, polyethylene sulfide resin, fluorine resin, or crosslinked polyolefin resin. The ink jet printer according to claim 5, wherein the ink jet printer is resin particles or a mixture of these particles.   The inkjet printer according to any one of claims 4 to 6, wherein the capturing member includes an impregnated burette compound represented by the general formula (1).

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