JP2009241467A - Filling liquid for inkjet printer head, inkjet printer head and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filling liquid for an inkjet printer head preventing poor ejection during printing by the inkjet printer by preventing a water-repellent film formed on the printer head from being peeled off, thereby, obtaining printed matter of good quality, and to provide the inkjet printer head and a printing method. <P>SOLUTION: There are provided the filling liquid for the inkjet printer head containing imidazole compound, the inkjet printer head filled with the filling liquid for the inkjet printer head, and the printing method comprising: a process to fill the ink flow path from the ink tank to the inkjet printer head with the filling liquid for the inkjet printer head; a process to discharge the filling liquid for the inkjet printer head from the ink flow path; a process to fill the ink flow path with inkjet ink; and a process to print with the inkjet ink. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a filling liquid for an inkjet printer head, an inkjet printer head, and a printing method.

  Usually, a water repellent film is provided on the surface of the nozzle plate of the ink jet printer head in order to prevent ink from spreading around the nozzles and causing defective ejection. The water-repellent film is mainly composed of a polyimide resin compound or a fluororesin compound, and in order to improve the adhesion to the metal that is the base material of the nozzle plate, a composite / eutectoid of the resin compound and a metal such as nickel. It is a film.

  Ink for ink jet printers includes γ-butyrolactone and N-methyl-2 as organic solvents having excellent permeability to the film substrate in order to improve the adhesion of printing on a film substrate such as a polyvinyl chloride sheet. -What blended heterocyclic compounds, such as pyrrolidone, is indicated (patent documents 1 and 2). However, since these heterocyclic compounds have a strong dissolving power, if they are blended into the ink composition, they will attack the metal in the composite / eutectoid film of the printer head, and the peeled water-repellent film will discharge nozzle clogs, flight bends, etc. There was a problem that caused defects.

As means for solving these problems, a method of blending a metal coordination compound comprising benzotriazole and a derivative thereof into an ink composition is disclosed (Patent Document 3). However, it binds to pigments in the ink in a low temperature environment, and the metal coordination compound precipitates to cause nozzle clogging, and further, the metal coordination compound remains in the printed matter, resulting in gloss reduction and scratching. There was a problem of deteriorating the ink film characteristics of the printed matter, such as a decrease.
International Publication No. 2004/007626 Pamphlet Japanese Patent Laid-Open No. 2005-23298 JP 2006-37020 A

  An object of the present invention is to solve the above-described problems, and prevents defective discharge when printing with an ink jet printer by preventing peeling of the water repellent film of a printer head having a water repellent film. It is an object to provide a filling liquid for an ink jet printer head that can produce a print product that is preferable in terms of quality.

  Another object of the present invention is to provide an ink jet printer head filled with the ink jet printer head filling liquid and a printing method for printing with a printer equipped with the head.

  According to the present invention, there is provided an ink jet printer head filling liquid characterized by containing an imidazole compound.

  In addition, according to the present invention, there is provided an ink jet printer head characterized by being filled with the above filling liquid for an ink jet printer head.

Furthermore, in accordance with the present invention, a step of filling the ink flow path from the ink tank to the ink jet printer head with the filling liquid for the ink jet printer head,
Discharging the ink jet printer head filling liquid from the ink flow path;
Filling the ink flow path from the ink tank to the ink jet printer head with ink for ink jet;
Printing with the inkjet ink;
There is provided a printing method characterized by comprising:

  The present invention relates to an ink jet ink containing a heterocyclic compound such as γ-butyrolactone and an amide such as N-methyl-2-pyrrolidone for printing on a film substrate such as a polyvinyl chloride sheet. Even if it does not contain a metal coordination compound comprising benzotriazole and its derivative, it is possible to prevent peeling of the water-repellent film of the printer head, and there is no ink discharge failure, and a printed matter preferable in terms of quality is obtained. It is possible to provide an ink jet printer head filling liquid obtained, an ink jet printer head filled with the ink jet printer head filling liquid, and a printing method for printing with a printer equipped with the head.

  As a result of intensive studies, the present inventors have found that the object of the present invention can be achieved by using a filling liquid for an inkjet printer head characterized by containing an imidazole compound, and have completed the present invention.

  Below, the filling liquid for inkjet printer heads of the present invention will be specifically described.

  Inkjet printer head filling liquid is a liquid that fills the head of an inkjet printer that has undergone printing inspection, and is a nozzle caused by the inside of the head drying out during long periods of non-use, storage, and printer transport / distribution. It is a liquid for preventing clogging and ink ejection failure.

  Examples of the imidazole compound used in the present invention include imidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, benzimidazole, 2-phenyl-benzimidazole, 2-mercaptomethylbenzimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, naphthimidazole, 1-cyanoethyl-2-methylimidazole, 1-aminoethyl-2-methylimidazole, 2,4-diamino-6- (2 -Undecyl-1-imidazolylethyl) -1,3,5-triazine, 2-phenyl-4-methyl-5-hydroxymethylimidazole and the like are preferable, and in particular, imidazole, 2-methylimidazole and benzimidazole are peeled off from the water-repellent film. Prevention And from the viewpoint of nozzle clogging property.

  The content of the imidazole compound is preferably in the range of 0.01 to 20% by mass and more preferably in the range of 0.05 to 10% by mass in the entire filling liquid. If it is less than 0.01% by mass, the effect of protecting the water-repellent film cannot be obtained, and nozzle clogging and ejection failure are likely to occur. When it exceeds 20 mass%, when the liquid temperature of the filling liquid is lowered, the imidazole compound is precipitated, and a problem that the effect of protecting the water-repellent film cannot be obtained easily occurs.

  The water content of the filling liquid in the present invention is preferably 1% by mass or less. When the amount of water in the filling liquid exceeds 1% by mass, the dissolving power of the imidazole compound is lowered, and a problem that the effect of protecting the water-repellent film cannot be obtained easily occurs.

  In the filling liquid of the present invention, any solvent can be used without particular limitation as long as it is a solvent that can dissolve the imidazole compound without drying the inside of the head during long-term non-use / storage or printer transfer / distribution. For example, hydrocarbons, alcohols, ethers, esters, acetals, ketones, aldehydes, polyhydric alcohols, polyhydric alcohol derivatives, phenols, nitrogen-containing compounds, etc., safety, drying properties From the viewpoint, it can be used in various mixtures as required. Of these, ethers, esters, polyhydric alcohols and polyhydric alcohol derivatives are preferred, and (poly) alkylene glycol (di) alkyl ethers are more preferred. Examples of the (poly) alkylene glycol (di) alkyl ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene Glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl methyl ether, diethylene glycol monohexyl ether, diethylene glycol mono 2-ethylhexyl ether, diethylene glycol dimethyl ether Diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol monomethyl ether, Tetraethylene glycol dimethyl ether, pentaethylene glycol monomethyl ether, pentaethylene glycol dimethyl ether, hexaethylene glycol monomethyl ether, hexaethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether Propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monophenyl ether, propylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipyrylene glycol Dimethyl ether, dipropylene glycol diethyl ether, tripropylene glycol dimethyl ether, tetrapropylene glycol dimethyl ether, butylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether And ether acetate and dipropylene glycol monomethyl ether acetate.

  Among these, ethylene glycols, diethylene glycols, triethylene glycols, propylene glycols, dipropylene glycols, and derivatives thereof are more preferable from the viewpoint of solubility and volatility in imidazole compounds.

  Furthermore, the (poly) alkylene glycol (di) alkyl ether or derivative thereof is preferably contained in an amount of 10 to 95% by mass, more preferably 20 to 90% by mass, based on the entire filling liquid. When the (poly) alkylene glycol (di) alkyl ether or its derivative is less than 10% by mass, there is a possibility that pigments, resin components, and the like may aggregate when the inside of the head is replaced with ink. Further, it is preferable that 3 to 70% by mass of the whole filling liquid contains a solvent having a boiling point of 250 ° C. or more from the viewpoint of preventing volatilization of the solvent that causes the filling liquid to decrease, more preferably the whole filling liquid. Of 5 to 60% by mass. Examples of the solvent having a boiling point of 250 ° C. or higher include ethylene glycol monobenzyl ether, diethylene glycol dibutyl ether, diethylene glycol monohexyl ether, diethylene glycol monobenzyl ether, diethylene glycol mono 2-ethylhexyl ether, diethylene glycol monophenyl ether, triethylene glycol monobutyl ether, Triethylene glycol butyl methyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol monomethyl ether, pentaethylene glycol dimethyl ether, hexaethylene glycol monomethyl ether, hexaethylene glycol dimethyl ether, 2,2,4-trimethyl 1,3-pentanediol diisobutyrate, diethyl adipate, dibutyl sebacate, dioctyl sebacate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, glyceryl triacetate.

  In the filling liquid of the present invention, additives such as a surface modifier, a viscosity modifier, a UV absorber, a light stabilizer, an antioxidant, and a plasticizer can be blended as necessary.

  The filling liquid of the present invention can be used for a head of a conventionally known ink jet printer having a water repellent film composed of a composite / eutectoid film of a polyimide resin compound, a fluororesin compound and a metal such as nickel. Examples of such a head include a load control method, an ink-on-demand method, and a method in which ink is ejected by a thermal head. After discharging the filling liquid of the present invention, a known ink used as an ink jet printer can be used as the ink to be filled instead. For example, an ink composed of a coloring agent such as a dye or pigment and an organic solvent, an ink having a binder resin in addition to the above ink, and the like. In the present invention, the adhesion of printing to a film substrate such as a polyvinyl chloride sheet In particular, the present invention is particularly effective for an ink containing a heterocyclic compound such as γ-butyrolactone or N-methyl-2-pyrrolidone as an organic solvent for an ink having excellent permeability to the substrate. As described above, the heterocyclic compound such as γ-butyrolactone and N-methyl-2-pyrrolidone contained in the ink will invade the water-repellent film of the printer head due to its strong solubility. When the imidazole compound in the filling liquid is coordinated to the water repellent film, a heterocyclic compound such as γ-butyrolactone or N-methyl-2-pyrrolidone can be used as the organic solvent for the ink to be filled later. This is because peeling of the water repellent film is prevented.

  Therefore, since it is not necessary to mix a metal coordination compound composed of benzotriazole and its derivative in the ink composition, the metal coordination compound precipitates by binding to a pigment in the ink under a low temperature environment. It is possible to prevent nozzle clogging and further deterioration of the ink film characteristics of the printed matter due to the metal coordination compound remaining in the printed matter.

  The filling liquid of the present invention can also be used for a printer head that does not have the above water-repellent film.

  Hereinafter, the present invention will be described in detail with reference to examples. In the examples, “parts” and “%” are based on weight.

[Examples 1 to 11 and Comparative Example 1]
After the components shown in Table 1 were uniformly mixed, the mixture was filtered and purified with a membrane filter having a pore size of 1.0 μm to prepare a filling liquid for an ink jet printer corresponding to each example and each comparative example. Each of the obtained filling liquids was filled into the ink flow path from the ink tank of the large format inkjet printer having a water repellent film on the printer head to the inkjet printer head, and was allowed to stand for 7 days. Thereafter, the filling liquid in the flow path was discharged and ink 1 or 2 having the following composition was filled.

<Ink 1 formulation>
・ Carbon black (trade name: Monarch 1000, manufactured by Cabot) 4 parts ・ γ-butyrolactone 17 parts (made by Mitsubishi Chemical Corporation)
・ 58 parts of diethylene glycol diethyl ether (trade name: DEDG, manufactured by Nippon Emulsifier Co., Ltd.)
・ 18 parts of propylene glycol monomethyl ether acetate (trade name: PMA, manufactured by Kyowa Hakko Chemical Co., Ltd.)
・ Vinyl chloride copolymer (trade name: VYHD, manufactured by Dow Chemical Co.) 3 parts

<Ink 2 formulation>
・ Carbon black (trade name: Monarch 1000, manufactured by Cabot Corporation) 4 parts ・ N-methyl-2-pyrrolidone 16 parts (produced by Mitsubishi Chemical Corporation)
・ Diethylene glycol diethyl ether 61 parts (trade name: DEDG, manufactured by Nippon Emulsifier Co., Ltd.)
・ 16 parts of propylene glycol monomethyl ether acetate (trade name: PMA, manufactured by Kyowa Hakko Chemical Co., Ltd.)
・ Vinyl chloride copolymer (trade name: VYHD, manufactured by Dow Chemical Co.) 3 parts

  Immediately after filling the printer head in an environment of normal temperature and humidity (23 ° C./55% RH), after 3 months and 6 months, the nozzle clogging property was evaluated as follows.

<Nozzle clogging>
Images were continuously printed on a polyvinyl chloride sheet for 10 hours with an inkjet printer, and the printed state after printing was visually evaluated according to the following criteria. The evaluation results are shown in Table 1.
(Double-circle): There is no defect | deletion and all the dots have landed clearly in the predetermined position.
○: There is no defect, but there is a dot that cannot be printed at a predetermined position with 1% or less of all dots.
X: Nozzle clogging occurs and a defect occurs, and printing cannot be performed at a predetermined position.

<Method for measuring moisture content>
It measured with the coulometric titration type | mold water measuring apparatus (Brand name: VAPORIZER VA-06, CA-06, Mitsubishi Chemical Corporation make).

Example 11
In Example 1, the ink flow path from the ink tank of the large format inkjet printer having a water repellent film on the printer head to the inkjet printer head is filled, and the temperature is low under low humidity (5 ° C./15% RH). Evaluation was carried out in the same manner except that the sample was allowed to stand for months.

Note) Imidazole (trade name: IZ, manufactured by Nippon Synthetic Chemical Co., Ltd.)
Note) 2-Methylimidazole (trade name: 2MI, manufactured by Nippon Synthetic Chemical Co., Ltd.)
Note) benzimidazole (trade name: benzimidazole, manufactured by aldrich)

  As is apparent from the data shown in Table 1, the printer head having a water-repellent film filled with the filling liquids of Examples 1 to 11 contains a heterocyclic compound such as γ-butyrolactone and N-methyl-2-pyrrolidone. In the inkjet ink, the nozzle composition was not clogged even when the metal coordination compound composed of benzotriazole and its derivative was not blended in the ink composition, and good evaluation results were obtained. Furthermore, even if the printer head filled with the filling liquid of the present invention is left in Example 11 in a low temperature and low humidity (5 ° C./15% RH) environment for 6 months, there is no nozzle clogging and a good evaluation result is obtained. It was.

  On the other hand, in Comparative Example 1 using the filling liquid outside the range of the present invention, nozzle clogging occurred and printing was poor.

Claims (9)

  A filling liquid for an ink jet printer head comprising an imidazole compound.   The filling liquid for an ink jet printer head according to claim 1, wherein the water content of the filling liquid is 1% by mass or less.   The filling liquid for an inkjet printer head according to claim 1, wherein the imidazole compound is contained in an amount of 0.01 to 20% by mass of the whole filling liquid.   The filling liquid for an inkjet printer head according to any one of claims 1 to 3, wherein the imidazole compound is selected from the group consisting of imidazole, 2-methylimidazole, and benzimidazole.   The filling liquid for an inkjet printer head according to any one of claims 1 to 4, wherein (poly) alkylene glycol (di) alkyl ether or a derivative thereof is contained as a solvent in 10 to 95% by mass of the whole filling liquid.   The filling liquid for an ink jet printer head according to any one of claims 1 to 5, wherein a solvent having a boiling point of 250 ° C or higher is contained in 3 to 70 mass% of the whole filling liquid.   The filling liquid for an ink jet printer head according to claim 1, which is used for an ink jet printer having a water repellent film on the printer head.   An ink jet printer head, which is filled with the filling liquid for an ink jet printer head according to claim 1. Filling the ink flow path from the ink tank to the ink jet printer head with the filling liquid for an ink jet printer head according to claim 1;
Discharging the ink jet printer head filling liquid from the ink flow path;
Filling the ink flow path from the ink tank to the ink jet printer head with ink for ink jet;
Printing with the inkjet ink;
A printing method characterized by comprising: