JP2014210370A - Injecting liquid of physical distribution for ink jet head, ink jet head and physical distribution method of ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injecting liquid for physical distribution of an ink jet head capable of effectively preventing: solidification of ink due to long-term storage; contamination on a heater surface; deterioration in discharge performance and printing quality due to liquid accumulation at a discharge port peripheral edge part and the like, especially the occurrence of "distorted printing".SOLUTION: A injecting liquid for physical distribution of an ink jet head is injected in a nozzle flow path communicating with an ink discharge port in physical distribution of a thermal ink jet head. In the ink jet head, an opening area of the ink discharge port is 100-350 μm, and a water repellency region is formed on a peripheral edge of the ink discharge port. At least in an aqueous medium having a water-soluble organic compound and water as components, a dye is dissolved, and the dye is contained so that the concentration of the dye is equal to or greater than 0.2 mass% and equal to or less than 1 mass% with respect to the total mass of the injecting liquid for physical distribution, and also the concentration is equal to or less than saturation solubility with respect to the water-soluble organic compound. Surface tension is equal to or greater than 35 mN/m.

Description

  The present invention relates to a distribution filling liquid that fills a nozzle flow path that communicates with an ink discharge port when distributing a thermal inkjet recording head (inkjet head), an inkjet head using the same, and an inkjet head Is related to the logistics method.

  Conventionally, as a thermal ink jet head, a plurality of nozzle flow paths partitioned by nozzle walls are formed, a plurality of ink discharge ports communicating with the nozzle flow paths are formed, and a heater is provided inside each nozzle flow path. The thing of the structure where is arranged is known. The ink jet head having the above structure has a mechanism in which ink filled in the nozzle flow path is heated by a heater and the ink is foamed to cause ink droplets to fly from the ink discharge port.

  In the ink jet head having the above structure, if the nozzle channel is pre-filled with printing ink for a long period of time, the ink will thicken or solidify due to volatilization of the ink solvent. There was a problem that the discharge performance deteriorated. In the piezo method in which ink droplets are ejected by mechanical deformation by a piezoelectric element, the ink can often be restored by a head recovery operation even if the ink is thickened or solidified. In the thermal method in which the liquid droplets are caused to fly, the above problem becomes more serious. On the other hand, if the nozzle flow path is emptied and stored for a long time, the heater surface is exposed to the outside air and contaminated, and there is a problem that the ejection performance of the head is lowered during printing and the printing quality is lowered.

  Therefore, it has been proposed that the recording head is filled exclusively with storage ink instead of printing ink during storage before use or during distribution (Patent Document 1). In Patent Document 1, it is proposed to use a liquid containing water and diethylene glycol, a degassed ink, or the like as the storage ink. In addition, it has also been proposed to fill a preservative solution composed of a humectant, a nonionic surfactant, and a dye in the flow path of the head during shipment, transportation, and storage of the printer (Patent Document 2). In Patent Document 2, it is proposed to use a water-soluble organic solvent having a plurality of hydroxyl groups, among which a viscosity of less than 40 centipoise is used as a humectant.

  Furthermore, the thermal ink jet head is a mechanism that causes ink to fly by thermal energy, and it is known that the surface condition around the ink ejection port has a significant effect on the ink ejection performance (head ejection performance). ing. Specifically, depending on the surface condition around the ink ejection port, there is a problem that the ejected ink wraps around the outer surface (also referred to as a face surface) of the ink ejection port and a liquid pool is generated around the ejection port. . This liquid pool is not preferable because it causes the ink to fly out of the original flight direction (regular direction), leading to the occurrence of so-called “fridation printing” and deterioration of print quality.

  Therefore, in a recording head for aqueous pigment ink, it has been proposed to form a water-repellent region in a region around the discharge port on the face surface (Patent Document 3). In Patent Document 3, it is proposed to form a water-repellent region by coating with a water repellent.

JP-A-5-169676 JP 2000-168056 A Japanese Patent Laid-Open No. 11-334074

  The preserving ink described in Patent Document 1 and the preserving liquid described in Patent Document 2 have a certain effect in terms of preventing ink solidification and heater contamination associated with long-term storage and maintaining head ejection performance and print quality. However, there were the following problems.

  In recent years, in an inkjet printer, there is a demand for pixel miniaturization in order to perform high-definition and high-resolution printing (for example, the amount of one ink droplet is 10 pL or less), and the ink discharge port size of the inkjet head is also large. It is shrinking. Even if the preserving ink described in Patent Document 1 or the preserving liquid described in Patent Document 2 is applied to an ink jet head having such a small-diameter ink discharge port, the ink thickens and solidifies during long-term storage. There is a problem that the effect of preventing the contamination of the heater and the heater and maintaining the discharge performance of the head and the print quality cannot be obtained sufficiently.

  Further, when the storage ink described in Patent Document 1 or the storage liquid described in Patent Document 2 is applied to a recording head in which the water-repellent area as described in Patent Document 3 is formed, the surface state of the water-repellent area is described. There has been a problem that the water repellency is lowered due to the change. In such a case, although the water-repellent region is formed on the discharge port formation surface, the discharge performance as originally expected cannot be obtained, and “sludge printing” or a reduction in print quality occurs.

  The present invention has been made to solve the above-described problems of the prior art. That is, the present invention is effective in increasing the viscosity and solidification of ink accompanying long-term storage, contamination of the heater surface, deterioration in ejection performance and printing quality due to liquid pooling at the peripheral edge of the ejection port, etc. The present invention provides a liquid filling liquid for an inkjet head that can be easily prevented, an inkjet head using the same, and a logistics method for the inkjet head.

  As a result of intensive studies on the above problems, the present inventors have conceived that the above problems can be solved by precisely controlling the composition and physical properties of the distribution filling liquid, and have completed the present invention. . That is, according to the present invention, the following ink filling liquid for an inkjet head, an inkjet head, and an inkjet head logistics method are provided.

[1] Logistics filling liquid:
According to the present invention, when distributing a thermal ink jet head, the ink jet head filling liquid is filled in a nozzle flow path communicating with the ink discharge port, and the ink jet head includes the ink discharge port. an opening area of a 100～350Myuemu ² of, which the water repellent region is formed on the periphery of the ink discharge port, in an aqueous medium as a constituent at least a water-soluble organic compound and water, dissolved dyes The dye is contained at a concentration of 0.2% by mass or more and 1% by mass or less with respect to the total mass of the packing liquid for physical distribution, and at a concentration of saturated solubility or less with respect to the water-soluble organic compound, and surface tension. Is 35 mN / m or more. A filling liquid for logistics of an inkjet head is provided.

  In the logistics filling liquid of the present invention, the water-soluble organic compound is a water-soluble organic solvent having a vapor pressure at 20 ° C. of 3 Pa or lower; as the water-soluble organic compound, Use a solution in which a solid water-soluble organic compound is dissolved at ° C; the water-soluble organic compound is contained at a concentration of 40% by mass or less with respect to the total mass of the packing liquid for logistics; It is preferably 1.3 mPa · s or more and 5.0 mPa · s or less.

[2] Inkjet head:
According to the present invention, there is provided a thermal ink jet head, wherein the ink discharge port has an opening area of 100 to 350 μm ² and a water-repellent region is formed at the periphery of the ink discharge port. There is provided an ink jet head characterized in that the nozzle flow path communicating with the ink discharge port is filled with the distribution filling liquid of the present invention.

  In the ink jet head of the present invention, a water-repellent region having a contact angle with water of 90 ° or more is formed at the periphery of the ink discharge port; a plurality of nozzle flow paths partitioned by nozzle walls are formed. A plurality of ink discharge ports communicating with the nozzle flow path are formed, and a heater is disposed inside each nozzle flow path; the nozzle wall is formed of an epoxy-based photosensitive resin; Is preferred.

  In the ink jet head of the present invention, the common liquid chamber communicated with the plurality of nozzle channels, the opening communicated with the common liquid chamber, the main liquid supply chamber communicated with the opening, and the main liquid A liquid supply path that communicates with the supply chamber, a liquid supply chamber that communicates with the liquid supply path, the first liquid supply chamber from the upstream side along the flow during liquid supply, and the second liquid A supply filter disposed so as to be separated into a supply chamber, a gas-liquid separation unit provided in a part of the main liquid supply chamber, and an air chamber communicating with the gas-liquid separation unit, A nozzle channel, the common liquid chamber, the opening, the main liquid supply chamber, the liquid supply path, the liquid supply chamber, the supply filter, the gas-liquid separation unit, and the air chamber. The arrangement direction of the nozzle flow path and the liquid The main liquid supply chamber, the liquid supply path, the supply filter, the gas-liquid separation unit, and the air chamber are stacked on a plane parallel to the plane including the discharge direction. It is preferable to arrange | position without.

  Furthermore, in the inkjet head of the present invention, it is preferable that the resolution is 600 dpi or more, and the length of the nozzle row formed by the plurality of nozzle channels is 2 inches or more.

[3] Logistics method:
According to the present invention, there is provided an ink jet head distribution method for distributing a thermal ink jet head, wherein the ink discharge port has an opening area of 100 to 350 μm ² as the ink jet head. An inkjet head characterized in that a water repellent region is formed at the periphery, and the inkjet head is distributed in a state where the nozzle flow path communicating with the ink discharge port is filled with the distribution filling liquid of the present invention. A logistics method is provided.

  In the physical distribution method of the present invention, as the ink jet head, one having a water-repellent region having a contact angle with water of 90 ° or more formed at the periphery of the ink discharge port is used; However, the distribution filling liquid of 1.3 mPa · s or more and 5.0 mPa · s or less is filled, the printing inspection is performed with the distribution filling liquid, and then the nozzle flow path is filled with the distribution filling liquid. In this state, the ink jet head is distributed; a plurality of nozzle flow paths partitioned by nozzle walls are formed as the ink jet head, and a plurality of ink discharge ports communicating with the nozzle flow paths are formed. Use a heater with a heater inside the path; the nozzle wall of the inkjet head is made of epoxy photosensitive resin. ; It is preferable.

  In the physical distribution method of the present invention, as the inkjet head, a common liquid chamber that communicates with the plurality of nozzle channels, an opening that communicates with the common liquid chamber, a main liquid supply chamber that communicates with the opening, A liquid supply path that communicates with the main liquid supply chamber, a liquid supply chamber that communicates with the liquid supply path, and a first liquid supply chamber from the upstream side along the flow during liquid supply; A supply filter disposed so as to be separated from the second liquid supply chamber, a gas-liquid separator provided in a part of the main liquid supply chamber, and an air chamber communicating with the gas-liquid separator. Comprising, the nozzle flow path, the common liquid chamber, the opening, the main liquid supply chamber, the liquid supply path, the liquid supply chamber, the supply filter, and the gas-liquid separation section, The air chamber is an arrangement of the nozzle channels The main liquid supply chamber, the liquid supply path, the supply filter, the gas-liquid separator, and the air chamber are arranged on a parallel plane with respect to the plane including the direction and the liquid discharge direction. However, it is preferable to use those which are arranged without being laminated.

  In the physical distribution method of the present invention, as the ink jet head, one having a resolution of 600 dpi or more and a nozzle row formed by the plurality of nozzle flow paths of 2 inches or more is used; It is preferable to carry out distribution in a state of being mounted on the main body of the apparatus.

  The logistics filling liquid of the present invention, the inkjet head, and the inkjet head logistics method have the following characteristics: ink thickening and solidification associated with long-term storage, contamination of the heater surface, ejection performance and print quality associated with liquid pooling at the periphery of the ejection orifice, etc. It is possible to effectively prevent the deterioration, in particular, the occurrence of “sink printing”.

It is a top view which shows typically the internal structure of the nozzle of an inkjet head. It is a side view which shows typically the internal structure of the nozzle shown to FIG. 1A. It is a front view which shows typically the ink discharge port of the nozzle shown to FIG. 1A. It is a front view which shows typically the inkjet head of this invention. It is AA sectional drawing of the inkjet head shown to FIG. 2A. It is BB sectional drawing of the inkjet head shown to FIG. 2A. 1 is a front view schematically showing an overall configuration of an ink jet recording apparatus. It is process drawing which shows the flow of the printing inspection of the conventional inkjet head. It is process drawing which shows one flow of the printing test | inspection of the inkjet head of this invention. It is process drawing which shows another flow of the printing test | inspection of the inkjet head of this invention.

  Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following embodiment, and includes all objects having the invention-specific matters. In this specification, “logistics” refers to the entire distribution process of products from producers (manufacturers) to consumers (users). In addition to transportation, packaging, storage before and after transportation, etc. It includes all processes from the manufacture of a product by a consumer (manufacturer) to the start of use by a consumer (user).

[1] Logistics filling liquid:
The “distribution filling liquid” is a liquid that fills a nozzle flow path that communicates with the ink discharge port when distributing a thermal ink jet head. This distribution filling liquid is filled into the nozzle flow path by the producer (manufacturer) before distributing the inkjet head. The logistics filling liquid is replaced with printing ink (recording liquid) when the consumer (user) uses the inkjet head, and is discharged outside the head. The logistics filling liquid of the present invention can be suitably used for a small-diameter inkjet head having an ink discharge port opening area of 100 to 350 μm ² and a water-repellent head in which a water-repellent region is formed at the periphery of the ink discharge port. .

  The logistics filling liquid of the present invention is obtained by dissolving a dye in an aqueous medium containing at least a water-soluble organic compound and water as constituent components.

[1-1] Dye:
The filling liquid for logistics of the present invention contains a dye as a coloring material. By containing a predetermined amount of dye, it is effective to reduce water repellency caused by impurities contained in trace amounts in aqueous media (water, water-soluble organic compounds, etc.) and head components, etc. Can be prevented. The use of a dye instead of a pigment as a coloring material is unlikely to cause a phenomenon in which pigment particles settle and stick to the ink discharge port as in the case of a pigment. This is because it is difficult for problems such as nozzles to occur. In addition, by including a predetermined amount of dye, it is possible to perform a print inspection with a distribution filling liquid.

  The molecular structure of the dye is not particularly limited, but a water-soluble dye is preferably used. For example, the following yellow dyes, red dyes, violet dyes, blue dyes, black dyes and the like can be suitably used. In order to use a yellow dye with low visibility for print inspection, a recording medium for print inspection is colored in advance with a blue dye, or a print pattern formed with a yellow dye such as black light or LED light is used. It is necessary to make the yellow dye visible by a method such as irradiating light.

[1-1A] Yellow dye:
Examples of yellow dyes include C.I. I. Direct yellow, C.I. I. Acid Yellow, C.I. I. Reactive Yellow, C.I. I. Food yellow etc. can be mentioned. In particular,
(1) C.I. I. Direct yellow 8, 11, 12, 27, 28, 33, 39, 44, 50, 58, 85, 86, 87, 88, 89, 98, 100, 110, 132, 142;
(2) C.I. I. Acid Yellow 1, 3, 7, 11, 17, 23, 25, 29, 36, 38, 40, 42, 44, 76, 98, 99;
(3) C.I. I. Reactive Yellow 2, 3, 17, 25, 37, 42;
(4) C.I. I. It is preferable to use Food Yellow 3;

[1-1B] Red dye:
Examples of red dyes include C.I. I. Direct Red, C.I. I. Acid Red, C.I. I. Reactive Red, C.I. I. Food red etc. can be mentioned. In particular,
(1) C.I. I. Direct Red 2, 4, 9, 11, 20, 23, 24, 31, 39, 46, 62, 75, 79, 80, 83, 89, 95, 197, 201, 218, 220, 224, 225, 226, 227, 228, 229, 230;
(2) C.I. I. Acid Red 6, 8, 9, 13, 14, 18, 26, 27, 32, 3537, 42, 51, 52, 80, 83, 87, 89, 92, 106, 114, 115, 133, 134, 145, 158, 198, 249, 265, 289;
(3) C.I. I. Reactive Red 7, 12, 13, 15, 17, 20, 23, 24, 31, 42, 45, 46, 59;
(4) C.I. I. It is preferable to use Food Red 87, 92, 94;

[1-1C] Violet dye:
Examples of the violet dye include C.I. I. Direct violet and the like can be mentioned. Specifically, C.I. I. Direct violet 107; etc. are preferably used.

[1-1D] Blue dye:
Examples of blue dyes include C.I. I. Direct Blue, C.I. I. Acid Blue, C.I. I. Examples include reactive blue. In particular,
(1) C.I. I. Direct Blue 1, 15, 22, 25, 41, 76, 77, 80, 86, 87, 90, 98, 106, 108, 120, 158, 163, 168, 199, 226;
(2) C.I. I. Acid Blue 1, 7, 9, 15, 22, 23, 25, 29, 40, 43, 59, 62, 74, 78, 80, 90, 100, 102, 104, 117, 127, 138, 158, 161;
(3) C.I. I. Reactive blue 4, 5, 7, 13, 14, 15, 18, 19, 21, 26, 27, 29, 32, 38, 40, 44, 100;

[1-1E] Black dye:
Examples of black dyes include C.I. I. Direct black, C.I. I. Acid Black, C.I. I. Food black etc. can be mentioned. In particular,
(1) C.I. I. Direct black 17, 19, 22, 31, 32, 51, 62, 71, 74, 112, 113, 154, 168, 195;
(2) C.I. I. Acid Black 2, 48, 51, 52, 110, 115, 156;
(3) C.I. I. It is preferable to use food black 1, 2;

  The dye is contained at a concentration of 0.2% by mass or more and 1% by mass or less with respect to the total mass of the logistics filling liquid. By setting the content to 0.2% by mass or more, the water repellency is reduced due to the impurities contained in a trace amount in the aqueous medium (water, water-soluble organic compound, etc.) and the constituent material of the head adhering to the water-repellent region of the head. Can be effectively prevented. By setting the amount to 1% by mass or less, it is possible to effectively prevent “twist printing” and nozzle clogging (occurrence of undischarge nozzles) caused by the dye sticking to the ink discharge port. Also, ink contamination due to color mixing can be prevented when replacing with recording ink. In order to obtain the effect more reliably, the dye is preferably contained at a concentration of 0.3% by mass or more and 0.8% by mass or less with respect to the total mass of the logistics filling liquid.

  In the case where a plurality of ink jet heads are mounted on the ink jet recording apparatus (for example, four colors of CMYK), it is preferable that the distribution liquid filling liquids for all ink jet heads have the same composition.

  The dye is contained at a concentration equal to or lower than the saturation solubility in the water-soluble organic compound. By setting the saturated solubility or less, the dissolved state of the dye is maintained even if the volatile component (water or the like) in the aqueous medium is volatilized. Accordingly, it is possible to effectively prevent “twisting printing” and nozzle clogging (occurrence of undischarge nozzles) due to the viscosity of the dye increasing or adhering to the ink discharge port. Here, “saturated solubility” means saturated solubility at 25 ° C.

  The saturation solubility of a dye in a water-soluble organic compound is, for example, by gradually changing the amount of dye to be added to 100 g of a water-soluble compound at 25 ° C. to prepare dye solutions having different concentrations, and measuring the absorbance for each dye solution. After measurement and filtration through a membrane filter having a pore size of 1 μm, the absorbance is measured again, and the absorbance can be determined from the dye concentration of the dye solution that causes a difference in absorbance before and after the filtration. For example, C.I. I. Food Black 2 (FB2) has a saturated solubility in glycerin of 4 (g / 100 g), a saturated solubility in diethylene glycol of 16 (g / 100 g), and a saturated solubility in triethylene glycol of 21 (g / 100 g).

[1-2] Aqueous medium:
In the packing liquid for logistics of the present invention, a dye is dissolved in an aqueous medium containing at least a water-soluble organic compound and water as constituent components.

[1-2A] Water-soluble organic compound:
The “water-soluble organic compound” means an organic compound that is freely mixed with water or has a solubility in water (25 ° C.) of 20 g / 100 g or more. Furthermore, in the present invention, the water-soluble organic compound is preferably a water-soluble organic solvent having a vapor pressure of 3 Pa or less at 20 ° C., that is, a hardly volatile compound. By using such a compound, even when a volatile component (such as water) in the aqueous medium has volatilized, the dissolved state of the dye can be maintained, and the precipitation and solidification of the dye can be prevented. . Moreover, what shows the solubility with respect to dye is preferable for a water-soluble organic compound.

  The molecular structure of the water-soluble organic compound is not particularly limited, and examples thereof include water-soluble organic solvents such as the following polyhydric alcohols, esters, lower alkoxy alcohols, amines, amides, and heterocyclic rings. Can do.

(1) Polyhydric alcohols:
Diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propylene glycol, isopropylene glycol, polypropylene glycol, pentamethylene glycol, trimethylene glycol, butylene glycol, isobutylene glycol, thio Diglycol, 1,2-hexanediol, 2-ethyl-1,3-hexanediol, 1,2 pentanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,3-propane Diol, 1,4-butanediol, 1,7-heptanediol, 1,8-octanediol, 2-butene-1,4-diol, glycerol, diglycerol and the like;

(2) Esters:
γ-butyrolactone, diacetin, triethyl phosphate, etc .;
(3) Lower alkoxy alcohols:
2-methoxyethanol, 2-ethoxyethanol, etc .;
(4) Amines:
Ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, triethylenetetramine, tetraethylenepentamine, pentamethyldiethylenetriamine and the like;

(5) Amides:
Formamide, N, N-dimethylformamide, N-methylformamide, N, N-dimethylacetamide and the like;
(6) Heterocycles:
2-pyrrolidone, N-ethylpyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, morpholine, N-ethylmorpholine, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, imidazole, methylimidazole, hydroxyimidazole , Dimethylaminopyridine, 1,3-propane sultone, hydroxyethyl piperazine, piperazine and the like;

  Among these, examples of water-soluble organic solvents having a vapor pressure at 20 ° C. of 3 Pa or less include diethylene glycol (2.7 Pa), triethylene glycol (0.02 Pa), glycerin (<0.01 Pa), and the like. it can. Among these, glycerin is particularly preferable.

  As the water-soluble organic compound, in addition to the water-soluble organic solvent, a solution obtained by dissolving a solid water-soluble organic compound in the water-soluble organic solvent at 20 ° C. can also be used. The solution is preferably a solution in which 1 g or more of the solid water-soluble organic compound is dissolved in 100 g of the water-soluble organic solvent at room temperature (20 ° C.), and more preferably a solution in which 5 g or more is dissolved. The specific structure of the solid water-soluble organic compound is not particularly limited. For example, ureas such as urea and ethylene urea; solids at normal temperature (20 ° C.) such as 1,6-hexanediol, inositol and trimethylolpropane Examples thereof include polyhydric alcohols; sugars such as glucose and sorbitol; In particular, urea is preferable in that it hardly volatilizes and has high water solubility. As the water-soluble organic solvent for dissolving the solid water-soluble organic compound, glycerin, triethylene glycol, tetraethylene glycol and the like are preferable.

  The concentration of the water-soluble organic compound is preferably 40% by mass or less, and more preferably 35% by mass or less, with respect to the total mass of the logistics filling liquid. By setting it to 40% by mass or less, it is difficult to remain in the nozzle flow path when replacing with printing ink, and the recovery operation for ink replacement can be minimized. In order to obtain the effect of adding a water-soluble organic compound, the concentration is preferably 15% by mass or more, and more preferably 20% by mass or more. A water-soluble organic compound may be used individually by 1 type, and 2 or more types may be mixed and used for it.

[1-2B] Water:
As water, it is preferable to use ion-exchanged water. The water content is preferably 30% by mass or more and 90% by mass or less with respect to the total mass of the distribution filling liquid. By setting the content to 30% by mass or more, the dye and the water-soluble organic compound can be hydrated, and aggregation of the dye and the water-soluble organic compound during distribution can be prevented. On the other hand, by setting the amount to 90% by mass or less, even when the amount of the water-soluble organic compound is relatively increased and the volatile component (water, etc.) in the aqueous medium is volatilized, the dissolved state of the dye is maintained. And the precipitation and solidification of the dye can be prevented. In order to exhibit the effect more reliably, the water content is more preferably 55% by mass or more and 85% by mass or less.

[1-2C] Surfactant:
The aqueous medium preferably contains a surfactant. The surfactant has the effect of improving the discharge stability of the distribution filler and the effect of adjusting the surface tension and wettability of the distribution filler. Although the kind of surfactant is not specifically limited, It is preferable to use a nonionic surfactant. Among them, a nonionic surfactant having a high hydrophilicity having an HLB value (Hydrophile-Lipophile Balance) of 10 or more is preferable. Specifically, it is preferable to use polyoxyethylene alkyl ether, ethylene oxide adduct of acetylene glycol, or the like.

  In order to obtain the effect of improving discharge stability, the content of the surfactant is preferably 0.1% by mass or more, and more preferably 0.15% by mass or more with respect to the total mass of the distribution filling liquid. More preferably. On the other hand, in order to suppress an increase in viscosity and a decrease in surface tension due to excessive addition, the content is preferably 2% by mass or less, more preferably 1% by mass with respect to the total mass of the distribution filling liquid. More preferably, the content is 2% by mass or less, and particularly preferably 0.18% by mass or less.

[1-2D] Other additives:
Additives other than surfactants may be added to the aqueous medium depending on the purpose. Examples of such additives include antifoaming agents, preservatives, antifungal agents, pH adjusting agents, antioxidants, and the like.

[1-3] Surface tension:
The packing liquid for physical distribution is adjusted to have a surface tension of 35 mN / m or more. By setting the surface tension to 35 mN / m or more, it is possible to prevent a decrease in water repellency of the water-repellent region formed at the periphery of the ink discharge port. Therefore, when printing is performed by replacing the packing liquid for distribution with the recording liquid, it is possible to prevent an increase in the number of printing and satellites. On the other hand, the upper limit of the surface tension is not particularly limited, but is preferably 43 mN / m or less, and more preferably 38 mN / m or less. Thereby, the destabilization of discharge can be prevented. The surface tension varies depending not only on the addition amount of surfactant and the type of surfactant contained in the distribution liquid, but also on the type and addition amount of organic solvent and dye.

  The surface tension of the packing liquid for logistics is a plate using a platinum plate using an automatic surface tension meter (for example, “CBVP-Z type” manufactured by Kyowa Interface Science Co., Ltd. under conditions of a temperature of 25 ° C. and a humidity of 50%). Means the value measured by method). The surface tension of the packing liquid for logistics can be adjusted by the addition amount of the surfactant, the kind and content of the water-soluble organic solvent, and the like.

[1-4] Viscosity:
The distribution filling liquid preferably has a viscosity of 1.3 mPa · s or more and 5.0 mPa · s or less. By setting the viscosity of the logistics filling liquid within the above range, it is possible to perform a print inspection using the logistics filling liquid. This point will be described in detail in the section of logistics method.

  The viscosity of the packing liquid for logistics is based on JIS Z8803, using an E type viscometer (for example, “RE-80L type viscometer” manufactured by Toki Sangyo Co., Ltd.) under the condition of a temperature of 25 ° C. It shall mean the measured value. The viscosity of the packing liquid for logistics can be adjusted by (addition amount of surfactant, addition amount of water-soluble organic compound) or the like.

[2] Inkjet head:
Hereinafter, an embodiment of the inkjet head of the present invention will be described with reference to FIGS. 1A to 1C and FIGS. 2A to 2C. However, the ink jet head of the present invention is not limited to the configuration described below.

[2-1] Nozzle part structure:
First, the structure of the nozzle portion will be described with reference to FIGS. 1A to 1C. FIG. 1A is a top view schematically showing an internal structure of a nozzle of an inkjet head. FIG. 1B is a side view schematically showing the internal structure of the nozzle shown in FIG. 1A. FIG. 1C is a front view schematically showing an ink discharge port of the nozzle shown in FIG. 1A.

  The ink jet head of the present invention is a thermal ink jet head. The thermal ink jet head has a plurality of nozzle channels 159 partitioned by nozzle walls 153 as shown in the figure, and a plurality of ink ejection ports 151 communicating with the nozzle channels 159. A heater 152 is disposed inside 159. In the illustrated form, a nozzle filter 155 is provided between the nozzle channel 159 and the common liquid chamber 156 for trapping foreign matter floating in the ink channel in the head. The top plate member 161 to which the nozzle top plate 162 is attached has an ink supply opening (not shown) formed by anisotropic etching or the like, and introduces external ink from the common liquid chamber 156 to the nozzle channel 159. It is configured to be possible.

  In addition to the right and left side surfaces of the nozzle channel 159 being partitioned by the nozzle wall 153, the upper surface side is partitioned by the nozzle top plate 162 and the bottom surface side is partitioned by the nozzle bottom plate 164. That is, the nozzle flow path 159 is a substantially rectangular columnar internal space partitioned from the surrounding space by using the nozzle wall 153, the nozzle top plate 162, and the nozzle bottom plate 164 as partitions. The nozzle top plate 162 is stacked on a top plate member 161 made of Si or the like, and the nozzle bottom plate 164 is stacked on the bottom plate portion 163.

The ink discharge port 151 is an opening that discharges ink formed at one end of the nozzle flow path 159 and communicates with the common liquid chamber 156 via the nozzle flow path 159. The ink discharge port 151 is formed on the face surface. In the illustrated example, the face surface is formed integrally with the nozzle wall 153, but a face plate may be separately provided to form the face surface. The ink discharge port 151 has an opening area of 100 to 350 μm ² . By setting the opening area to 100 μm ² or more, it is possible to prevent the occurrence of undischarge nozzles. On the other hand, by setting it to 350 μm ² or less, it is possible to form minute droplets in which the amount of one ink droplet is 10 pL or less, and the resolution can be 600 dpi or more. The opening area is represented by the product of the discharge port width 171 and the discharge port height 172.

  The nozzle flow path forms a nozzle row by a plurality of nozzle flow paths. The number of nozzle channels forming the nozzle row is not particularly limited, but in order to achieve the effects of the present invention, it is preferably 600 to 2400 per inch, and the length of the nozzle row is 2 inches or more. It is preferable that

  The heater 152 is a heating unit for heating and foaming the ink filled in the nozzle channel 159. The heater 152 is installed on the bottom plate portion 163. As the heater 152, a resistor (for example, a resistor made of tantalum nitride) can be used. An electrode (not shown) made of aluminum or the like for energization is connected to the heater 152, and a switching transistor (not shown) for controlling energization to the heater 152 is connected to one of the heaters 152. . The drive of the switch transistor is controlled by an IC including a circuit such as a control gate element, and the switch transistor is driven in a predetermined pattern by a signal from the outside of the head.

  The total length of the nozzle is preferably 200 μm or more and 300 μm or less. In this case, the “total length of the nozzle” means the length of the nozzle flow path 159, specifically, the common liquid chamber 156 from the end of the nozzle wall 153 constituting the nozzle flow path 159 on the ink discharge port 151 side. It means the length to the end of the side.

  The nozzle channel 159 includes a nozzle front portion 181 that is a portion from the heater center 157 to the end portion on the ink discharge port 151 side, and a nozzle rear portion 182 that is a portion from the heater center 157 to the end portion on the common liquid chamber 156 side. It is divided into. From the viewpoint of discharge speed, the flow resistance (front resistance) of the nozzle front part 181 and the flow resistance (rear resistance) of the nozzle rear part 182 have a front resistance / rear resistance value of 0.3 to 0.8. Is preferred. The flow resistance can be calculated by the Hagen-Poiseuille law from values such as the cross-sectional area of the flow path, the flow path length, and the viscosity of the ejected ink. That is, if the ink to be used (and its viscosity) is determined, the value of the front resistance / rear resistance can be adjusted by the flow path cross-sectional area of the nozzle, the flow path length, and the like.

[2-2] Water-repellent region:
In the ink jet head of the present invention, a water-repellent region is formed at the periphery of the ink discharge port. A water-repellent region having a contact angle with water of 90 ° or more is preferably formed at the periphery of the ink discharge port, and a water-repellent region having a contact angle with water of 100 ° or more is formed. Is more preferable. The contact angle can be measured by a contact angle meter (for example, trade name “SIMage-mini” manufactured by Excimer Co., Ltd., etc., using an ATAN 1 / 2θ method) in accordance with JIS R 3257.

  The water repellent region can be formed by a method of providing a water repellent film on the surface (face surface) of the member (face material) on which the ink discharge ports are formed.

  Examples of the method for providing the water repellent film on the face surface include a method of forming a super water repellent resin film on the face surface. The super water-repellent resin film can be formed by a conventionally known method. For example, a method of forming a resin film by applying a fluororesin, a silicone resin or the like on the face surface, a method of forming a fluororesin film by plasma polymerizing a fluorine-based monomer on the face surface, and the like can be given. Further, a method of forming a water- and oil-repellent resin film on the face surface may be employed. Examples thereof include a method of forming a film made of a fluororesin obtained by polymerizing a fluorocarbon compound. Among them, it is contained in fluorine-based solvents (“CXT-809A” manufactured by Asahi Glass Co., Ltd., “<Novec> HFE-7100”, “<Novec> HFE-7200”, “<Novec> HFE-71IPA”, etc., manufactured by Sumitomo 3M). A method in which a water-repellent film is formed by preparing a solution in which a fluorosilicone coupling agent (for example, “KP-801M” manufactured by Shin-Etsu Chemical Co., Ltd.) is dissolved and heat-depositing this solution on the face surface is preferable.

[2-3] Nozzle material:
The nozzle wall 153, the nozzle top plate 162, and the nozzle bottom plate 164 that partition the nozzle flow path 159 can be formed of, for example, a photosensitive resin. Examples of the photosensitive resin include a negative resist utilizing a radical polymerization reaction and a negative resist utilizing a cationic polymerization reaction.

  In negative resists using radical polymerization, radicals generated from the photopolymerization initiator contained in the resist cause polymerization and crosslinking between the radically polymerizable monomers and prepolymers contained in the resist. It hardens. Examples of the photopolymerization initiator include benzoins, benzophenones, thioxanthones, anthraquinones, acylphosphine oxides, titanocenes, and acridines. Although the kind of monomer or prepolymer is not particularly limited, a monomer or prepolymer having an acryloyl group, a methacryloyl group, an acrylamide group, a maleic acid diester, or an allyl group is preferable.

  In negative resists using cationic polymerization, cations generated from the photocation initiator contained in the resist cause polymerization and cross-linking between the cationically polymerizable monomers and prepolymers contained in the resist. It hardens. Examples of the photocation initiator include aromatic iodonium salts and aromatic sulfonium salts. Specifically, “Adekaoptomer SP-170” and “SP-150” manufactured by ADEKA, “BBI-103” and “BBI-102” manufactured by Midori Kagaku, and “Rhodorsil Photoinitiator 2074” manufactured by Rhodia. “IBPF”, “IBCF”, “TS-01”, “TS-91” manufactured by Sanwa Chemical Co., Ltd., and the like. Although the kind of monomer or prepolymer is not particularly limited, a monomer or prepolymer having an epoxy group, a vinyl ether group or an oxetane group is preferable. Specifically, bisphenol A type epoxy resin, novolak type epoxy resin, bisphenol novolak type epoxy resin and the like can be mentioned. Specifically, “Aron Oxetane OXT-121” manufactured by Toa Gosei Co., Ltd., “Celoxide 2021”, “GT-300 series”, “GT-400 series”, “EHPE3150” manufactured by Daicel Chemical Industries, etc. An epoxy resin etc. can be mentioned.

  Other negative photoresists include “SU-8 Series” and “KMPR-1000” manufactured by Kayaku Microchem Corporation, “TMMR”, “TMMR S2000” and “TMMF S2000” manufactured by Tokyo Ohka Kogyo Co., Ltd. It can also be used.

  In the present invention, it is preferable to use an epoxy photosensitive resin excellent in solvent resistance and strength as a nozzle wall. As a specific commercial product, “TMMR S2000” manufactured by Tokyo Ohka Kogyo Co., Ltd. is particularly preferable.

[2-4] Overall structure of the head:
Next, the overall structure of the inkjet head will be described with reference to FIGS. 2A to 2C. 2A is a front view for explaining an example of the structure of the inkjet head of the present invention, FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A, and FIG. 2C is a cross-sectional view taken along the line BB in FIG. is there. For convenience of explanation, the liquid supply case cover is omitted from the front view.

  As illustrated, the inkjet head includes a common liquid chamber 112 that communicates with a plurality of nozzle channels, an opening that communicates with the common liquid chamber 112, a main liquid supply chamber 126 that communicates with the opening, and a main liquid supply chamber. 126, the liquid supply port 127 communicating with the liquid supply port 127, the liquid supply chambers communicating with the liquid supply port 127 (the first liquid supply chamber 134 and the second liquid supply chamber 135), and the liquid supply chamber along the flow at the time of liquid supply. The supply filter 118 disposed so as to be separated into the first liquid supply chamber 134 and the second liquid supply chamber 135 from the upstream side, and the gas-liquid separator 120 provided in a part of the main liquid supply chamber 126. And an air chamber 141 communicating with the gas-liquid separator 120.

  A nozzle channel, a common liquid chamber 112, an opening, a main liquid supply chamber 126, a liquid supply port 127, a liquid supply chamber (first liquid supply chamber 134, second liquid supply chamber 135), The supply filter 118, the gas-liquid separator 120, and the air chamber 141 are arranged on a plane parallel to the plane including the nozzle channel arrangement direction and the liquid discharge direction, and the main liquid supply chamber 126, It is preferable that the liquid supply port 127, the supply filter 118, the gas-liquid separator 120, and the air chamber 141 are arranged without being stacked.

  A ceramic base plate 110 supports a heater substrate 111 formed of silicon. The heater substrate 111 has a plurality of electrothermal transducers (heaters or energy generators) as liquid discharge energy generating elements and a plurality of flow path walls for constituting nozzles corresponding to these electrothermal transducers. Is formed. The heater substrate 111 is also formed with a liquid chamber frame surrounding the common liquid chamber 112 communicating with each nozzle. A top plate 113 that forms the common liquid chamber 112 is joined to the side wall of the nozzle and the liquid chamber frame formed in this manner. Therefore, the heater substrate 111 and the top plate 113 are laminated and bonded to the base plate 110 in an integrated state. Such lamination adhesion is performed with an adhesive having good thermal conductivity such as silver paste. A mounted PCB (electric wiring board) 114 is supported by a double-sided tape (not shown) behind the heater substrate 111 in the base plate 110. Each ejection energy generating element on the heater substrate 111 and the PCB 114 are electrically connected by wire bonding corresponding to each wiring.

  A liquid supply member 115 is joined to the top surface of the top plate 113. The liquid supply member 115 includes a liquid supply case 116 and a liquid supply case cover 117. When the liquid supply case cover 117 closes the upper surface of the liquid supply case 116, a liquid chamber and a liquid supply path to be described later are formed. . In the present embodiment, the liquid supply case 116 and the liquid supply case cover 117 are joined by a thermosetting adhesive. The liquid supply case 116 is provided with a supply filter 118 and a discharge filter 119. The supply filter 118 is intended to remove foreign matter in the liquid supplied to the liquid supply member 115, and the discharge filter 119 is intended to prevent foreign matter from entering from the outside of the liquid discharge head. Each filter is fixed to the liquid supply case 116 by heat welding. Furthermore, a gas-liquid separation unit 120 is formed in a part of the liquid supply case 116, and a liquid level detection sensor 121 is mounted from the outside so as to protrude from the gas-liquid separation unit 120. Control the amount.

  Here, the configuration of the liquid chamber, the liquid supply path, and the like formed by fitting the two parts of the liquid supply case 116 and the liquid supply case cover 117 will be described. On the joint surface of the liquid supply case 116 with the top plate 113, a rectangular opening (hereinafter referred to as a liquid supply port 127) is formed substantially parallel to the nozzle arrangement direction and across the width of the nozzle row. On the extension of the liquid supply port 127, a main liquid supply chamber 126 having a storage chamber shape is formed. That is, the main liquid supply chamber 126 is formed substantially parallel to the nozzle row and across the width of the nozzle row. Further, the top surface on the side opposite to the liquid supply port 127 forms an inclination (hereinafter referred to as a main liquid supply chamber inclination 129) with the gas-liquid separation unit 120 as the uppermost portion over almost the entire region. Two openings are formed in the main liquid supply chamber inclination 129, one being the liquid communication part 131 and the other being the gas-liquid separation part 120.

  The gas-liquid separation unit 120 forms a part of the main liquid supply chamber 126 and has a depth larger than the other parts of the main liquid supply chamber 126. This is to enhance the effect of breaking bubbles that are mixed in the liquid in the liquid chamber, as will be described later. In the illustrated form, three stainless steel electrodes are mounted inside the gas-liquid separator 120, and are an upper limit detection electrode 123, a ground electrode 124, and a lower limit detection electrode 125 from the left side in the figure. The liquid level in the main liquid supply chamber 126 is maintained between the upper limit and the lower limit by energization between the ground electrode 124 and the upper limit detection electrode 123 and energization between the ground electrode 124 and the lower limit detection electrode 125. In the inkjet head of the illustrated form, the detection reliability can be improved by detecting the liquid level of the liquid that has undergone gas-liquid separation.

  On the extension of the gas-liquid separation unit 120, there is an air communication unit 130, and the tip is an air chamber 141 that functions as an air flow path. Further, the above-described discharge filter 119 is disposed and communicates with the discharge joint 133. The discharge filter 119 is made of a material having water repellency. If a liquid flows into the air flow path (air chamber 141) and the ink adheres to the discharge filter 119, an ink meniscus is formed inside the filter. However, the capillary force of the filter portion can be reduced by the water repellency, and the ink can be easily removed.

  On the other hand, a liquid supply port 127 is provided via a liquid communication portion 131 provided in the main liquid supply chamber inclination 129. The liquid supply port 127 has a tubular shape from the liquid communication part 131 to the vicinity of the supply filter 118 and is formed on substantially the same plane as the main liquid supply chamber 126. The supply filter 118 is also disposed on substantially the same plane as the main liquid supply chamber 126. The supply filter 118 is arranged so as to separate the liquid supply chamber into two chambers, and the chamber on the side communicating with the supply joint 132, that is, the upstream chamber along the flow of liquid supply in the liquid discharge head is the first liquid. The supply chamber 134 and the downstream side are the second liquid supply chamber 135. Since the supply filter 118 is disposed on substantially the same plane as the main liquid supply chamber 126, the first liquid supply chamber 134 and the second liquid supply chamber 135 adjacent to both surfaces of the supply filter 118 are also the main liquid supply chamber. 126 and the nozzle array surface 139 are arranged on a substantially parallel plane.

  The second liquid supply chamber 135 has an opening above the supply filter 118 (hereinafter referred to as a second liquid supply chamber opening 136), and communicates with the liquid supply port 127 through this. In addition, the top surface of the second liquid supply chamber 135 is formed with an inclination (hereinafter referred to as a second liquid supply chamber inclination 138) with this opening as the uppermost portion.

  As described above, the main liquid supply chamber 126, the gas-liquid separation unit 120, the liquid supply port 127, the supply filter 118, the first liquid supply chamber 134, and the second liquid supply chamber 135 are each substantially parallel to the nozzle arrangement surface 139. Set above. On the other hand, as shown in the AA cross section, it is important to arrange the main liquid supply chamber 126, the liquid supply path 127, the supply filter 118, and the gas-liquid separator 120 so as not to overlap each other in the vertical direction of the plane.

  The ink jet head of the present invention may be one in which the head and the ink tank are integrally formed, or may be one in which the head and the ink tank are separable. Inkjet heads of a type in which the head and the ink tank are configured to be separable may be distributed without mounting the ink tank. However, such a distribution form makes it difficult to ensure the sealing of the nozzle flow path. Degradation is likely to occur. The ink jet head of the present invention can effectively prevent problems such as defective discharge because the nozzle flow path is filled with the distribution filling liquid of the present invention.

[2-5] Filling of packing liquid for logistics:
The nozzle flow path communicating with the ink discharge port is filled with the distribution filling liquid of the present invention. The distribution filling liquid is preferably filled into at least a portion from the ink discharge port to the common liquid chamber (that is, the nozzle flow path and the common liquid chamber) in the cavity inside the inkjet head. Examples of the filling method include a method of injecting a logistics filling liquid into an ink tank, connecting the ink tank to an ink jet recording apparatus, and filling the logistics filling liquid into the nozzle flow path of the ink jet head by a suction operation. be able to.

[2-6] Inkjet recording apparatus:
Hereinafter, for reference, an ink jet recording apparatus (hereinafter also simply referred to as a recording apparatus) preferably used for the ink jet head of the present invention will be described with reference to FIG. FIG. 3 is a front view schematically showing the overall configuration of the ink jet recording apparatus.

  The illustrated recording apparatus 100 is an example of a recording apparatus using a long head 22 extending over the entire width direction of the recording area of the recording medium P. The recording apparatus 100 is connected to the host PC 102. The recording apparatus 100 performs recording by discharging liquid from four inkjet heads (hereinafter simply referred to as heads 22K, 22C, 22M, and 22Y) to the recording medium P based on the recording information transmitted from the host PC 102. . The illustrated recording medium P is roll paper. The four heads 22K, 22C, 22M, and 22Y are arranged along the conveyance direction (arrow A direction) of the recording medium P. The heads are arranged in parallel with each other in the order of the head 22K (for black ink), the head 22C (for cyan ink), the head 22M (for magenta ink), and the head 22Y (for yellow ink). The heads 22K, 22C, 22M, and 22Y are so-called line heads, in which nozzles are arranged at a predetermined density along a direction that intersects the recording medium conveyance direction (direction orthogonal to the drawing). The arrangement width of the nozzles (arrangement range in the recording medium conveyance direction) is equal to or larger than the maximum recording width of the recording medium used. When recording is performed by the recording apparatus, recording is performed by ejecting ink (recording liquid) from the nozzles by driving a heater provided in the head without moving each head.

  Along with recording, the ejection state of the head changes due to adhesion of foreign matters such as dust and ink droplets to the surface (face surfaces 22Ks, 22Cs, 22Ms, 22Ys) on which the ink ejection ports are formed, which affects recording. There is. Therefore, the recovery unit 40 is incorporated in the recording apparatus 100 so that liquid can be stably discharged from the heads 22K, 22C, 22M, and 22Y. By periodically cleaning the face surface by the recovery unit 40, the liquid discharge state from the nozzles of the heads 22K, 22C, 22M, and 22Y can be recovered to the initial good discharge state. The recovery unit 40 includes a cap 50 that is used to remove liquid and fine bubbles from the face surfaces 22Ks, 22Cs, 22Ms, and 22Ys of the four heads 22K, 22C, 22M, and 22Y during the cleaning operation. ing. The cap 50 is provided independently on the heads 22K, 22C, 22M, and 22Y.

  The recording medium P is supplied from the supply unit 24 and is conveyed in the direction of arrow A by the conveyance mechanism 26 incorporated in the recording apparatus 100. The transport mechanism 26 includes a transport belt 26a for placing and transporting the recording medium P, a transport motor 26b for rotating the transport belt 26a, and a roller 26c for applying tension to the transport belt 26a. When recording, when the recording medium P being conveyed reaches under the head 22K (for black ink), black ink is ejected from the head 22K based on the recording information sent from the host PC. Similarly, ink of each color is ejected in the order of the head 22C, the head 22M, and the head 22Y to complete color recording on the recording medium P.

[3] Physical Distribution Method The physical distribution method of the present invention is a thermal ink jet head distribution method. The inkjet head of the present invention described above is used as the inkjet head, and the inkjet head is distributed in a state where the nozzle flow path communicating with the ink discharge port of the inkjet head is filled with the distribution filling liquid of the present invention. Is. The distribution method of the present invention includes both a form in which the head is distributed alone and a form in which the head is distributed in a state where the head is mounted on the ink jet recording apparatus. Examples of the form of distribution with the head mounted on the recording apparatus include an aspect of distribution with the capped head mounted on the main body of the recording apparatus.

  By using the packing liquid for physical distribution of the present invention, the dissolved state of the dye is maintained even if the aqueous medium volatilizes during the physical distribution. Therefore, it is not necessary to perform a sealing process such as sealing an ink discharge port with a head cap or a face tape when distributing the inkjet head, and the manufacturing and packaging process of the inkjet head can be simplified. Further, it is possible to prevent problems such as the occurrence of an undischarge nozzle due to excessive adhesion of the head cap and the adhesive of the face tape. In addition, it is difficult to ensure sealing performance and the aqueous medium volatilizes more easily than when the inkjet head is distributed alone. Distribution with the ink tank separated or distribution with the inkjet head mounted on the inkjet recording device. Also, it can be suitably used.

  In the physical distribution method of the present invention, the nozzle flow path is filled with a logistics filling liquid having a viscosity of 1.3 mPa · s or more and 5.0 mPa · s or less, and a print inspection is performed with the logistics filling liquid. Thereafter, it is preferable that the ink jet head is distributed in a state where the nozzle flow path is filled with the distribution filling liquid. By using a distribution filling liquid having a viscosity of 1.3 mPa · s or more, generation of satellites and mists during print inspection can be suppressed, and appropriate print inspection can be performed. On the other hand, by using a logistics filling liquid of 5.0 mPa · s or less, ink refill (ink supply) to the recording head can be performed quickly during print inspection, and the occurrence of print rubbing can be suppressed. Can do. In order to obtain the effect more reliably, the viscosity is more preferably 1.5 mPa · s or more and 3.5 mPa · s or less, and is 1.7 mPa · s or more and 3.2 mPa · s or less. Is particularly preferred.

  By using a logistics filling liquid containing a predetermined amount of dye and having the above-mentioned viscosity, it is possible to perform a print inspection with the logistics filling liquid. Conventionally, as shown in the process diagram of FIG. 4, after the head manufacturing process, the nozzle flow path is filled with printing inspection liquid, and after inspection printing and determination, the printing inspection liquid is replaced with a distribution filling liquid. However, after distribution such as packing, transportation and storage in the state of the head, the head is mounted on the recording apparatus main body. This is because it is difficult to secure the sealing property and the aqueous medium is easily volatilized when the head is attached to the recording apparatus for distribution. However, in the distribution method using the distribution filling liquid of the present invention, as shown in the process diagram of FIG. 5, after performing the print inspection and determination, the head filled with the distribution filling liquid is placed in the recording apparatus main body. It is also possible to carry out physical distribution such as packing, transportation, storage, etc. with the equipment attached. Also, as shown in the process diagram of FIG. 6, after the head manufacturing process, the nozzle flow path is filled with a logistics filling liquid, and after inspection printing and determination, it is attached to logistics such as packing, transportation, and storage. Also good. According to this method, the step of replacing the inspection ink with the distribution filling liquid can be omitted, and the step can be simplified. Further, according to this method, the waste liquid of the printing inspection liquid does not occur.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the configurations of the following examples. In the following description, “parts” and “%” are based on mass unless otherwise specified.

(Measurement of saturation solubility)
First, saturation solubility (25 degreeC) was measured about the dye used by an Example and a comparative example. Examples of the dye include C.I. I. Food Black 2 (FB-2), C.I. I. Direct Blue 199 (DBL199), C.I. I. Direct yellow 86 (DY86) was used. Examples of water-soluble organic compounds include glycerin (GLY), triethylene glycol (TEG), diethylene glycol (DEG), a 1: 1 mixed solution of GLY and TEG, and a 10: 10: 1 mixture of GLY: TEG: ethyleneurea (EtU). Liquid, a 10: 10: 1 mixture of GLY: TEG: trimethylolpropane (TMP) was used. In addition, for a 10: 10: 1 mixture of GLY: TEG: EtU and a 10: 10: 1 mixture of GLY: TEG: TMP, EtU or TMP is 0.1 with respect to a 1: 1 mixture of GLY and TEG. It was prepared by mixing at the ratio.

  Saturation solubility was measured by gradually changing the amount of dye to be added to 100 g of water-soluble compound at 25 ° C. to prepare dye solutions having different concentrations, measuring the absorbance of each dye solution, and a membrane filter having a pore diameter of 1 μm. After the filtration, the absorbance was measured again and determined from the dye concentration of the dye solution in which the absorbance was different before and after the filtration. The results are shown in Table 1.

<Example 1>
As a dye, C.I. I. Food Black 2 (FB-2), glycerin as a water-soluble organic compound, and POE (10) acetylene glycol (“Acetyleneol E100” manufactured by Kawaken Fine Chemical Co., Ltd.) as a nonionic surfactant were used. Ion exchange water was added to FB-2 (0.2 parts by mass), glycerin (20 parts by mass), and nonionic surfactant (0.15 parts by mass) to make 100 parts by mass as a whole. After stirring this composition for 2 hours, the composition is filtered through a 1 μm membrane filter and passed through an ion exchange resin layer to remove impurities such as calcium, thereby obtaining a logistics filling liquid of Example 1. It was.

<Example 2>
A logistics filling liquid of Example 2 was obtained in the same manner as in Example 1 except that the amount of FB-2 added was changed to 0.4 parts by mass.

<Example 3>
A logistics filling liquid of Example 3 was obtained in the same manner as in Example 1 except that the amount of FB-2 added was changed to 0.5 parts by mass.

<Example 4>
A logistics filling liquid of Example 4 was obtained in the same manner as Example 1 except that the amount of FB-2 added was changed to 0.8 parts by mass.

<Example 5>
The logistics filling liquid of Example 5 was changed in the same manner as in Example 1 except that the amount of FB-2 added was changed to 0.8 parts by mass and the amount of water-soluble organic compound added was changed to 40 parts by mass. Obtained.

<Example 6>
A filling liquid for physical distribution of Example 6 was obtained in the same manner as Example 3 except that the water-soluble organic compound was changed to triethylene glycol.

<Example 7>
A logistics filling liquid of Example 7 was obtained in the same manner as Example 3 except that the water-soluble organic compound was changed to diethylene glycol.

<Example 8>
A logistics filling liquid of Example 8 was obtained in the same manner as in Example 3 except that the water-soluble organic compound was changed to a glycerin: triethylene glycol (1: 1) mixed liquid.

<Example 9>
The dye is C.I. I. Example 3 was changed to Direct Yellow 86 (DY86) in the same manner as in Example 3 except that the water-soluble organic compound was changed to a glycerin: triethylene glycol: ethylene urea (10: 10: 1) mixed solution. 9 logistics filling liquids were obtained.

<Example 10>
Example 10 was the same as Example 3 except that the dye was changed to DY86 and the water-soluble organic compound was changed to a glycerin: triethylene glycol: trimethylolpropane (10: 10: 1) mixture. A packing liquid for logistics was obtained.

<Example 11>
The dye is C.I. I. A logistics filling liquid of Example 11 was obtained in the same manner as Example 3 except that Direct Blue 199 (DBL199) was changed.

<Example 12>
A logistics filling liquid of Example 12 was obtained in the same manner as Example 3 except that the dye was changed to DY86.

<Example 13>
A logistics filling liquid of Example 13 was obtained in the same manner as in Example 11 except that the addition amount of the nonionic surfactant was changed to 0.1 parts by mass.

<Example 14>
Except that the addition amount of the nonionic surfactant was changed to 0.18 parts by mass, a logistics filling liquid of Example 14 was obtained in the same manner as Example 11.

<Comparative Example 1>
A logistics filling liquid of Comparative Example 1 was obtained in the same manner as in Example 1 except that the amount of FB-2 added was changed to 0.1 parts by mass.

<Comparative example 2>
The logistics filling liquid of Comparative Example 1 was obtained in the same manner as in Example 1 except that the amount of FB-2 added was changed to 1.5 parts by mass and the amount of glycerin added was 40 parts by mass.

<Comparative Example 3>
A logistics filling liquid of Comparative Example 3 was obtained in the same manner as in Example 3 except that the amount of glycerin added was 10 parts by mass.

<Comparative example 4>
A logistics filling liquid of Comparative Example 4 was obtained in the same manner as in Example 3 except that the addition amount of the nonionic surfactant was changed to 0.3 parts by mass.

<Comparative Example 5>
In Comparative Example 5, a distribution filling liquid having the same composition as in Example 3 was prepared. However, a hydrophilic head was used as the inkjet head in the following examination.

(Preparation of inkjet head)
An ink jet head having the nozzle structure shown in FIGS. 1A to 1C and the entire structure shown in FIGS. 2A to 2C was produced. The opening area of the ink discharge port was 225 μm ^2, and 4800 nozzles formed a nozzle row. The length of the nozzle row was 4 inches. The resolution of the head was 1200 dpi. The water repellent region was formed on the entire face surface. As shown in FIG. 1C, a top plate member 161 and a bottom plate portion 163 made of Si, a nozzle top plate 162 made of an epoxy-based photosensitive resin, a nozzle bottom plate 164, and a nozzle wall 153 are exposed on the face surface. That is, the face surface consists of the end surfaces of these members. A solution in which a fluorine-containing silicone coupling agent (“KP-801M” manufactured by Shin-Etsu Chemical Co., Ltd.) is dissolved in a fluorine-based solvent (“CXT-809A” manufactured by Asahi Glass Co., Ltd.) is prepared, and this solution is heated and evaporated over the entire face surface. To give a water-repellent region. The contact angle of the water repellent region with water was 103.3 ° (hereinafter, this head may be referred to as a “water repellent head”).

A head having the same structure as that of the inkjet head was used, and instead of forming the water-repellent region, one having a hydrophilic region was also produced. The hydrophilic region was formed on the entire face surface. Specifically, a hydrophilic treatment is performed by performing UV / O ₃ treatment on the face surface including the top plate member 161, the bottom plate portion 163, the nozzle top plate 162, the nozzle bottom plate 164, and the end face of the nozzle wall 153 as shown in FIG. 1C. Thus, a hydrophilic region was formed. The contact angle between the hydrophilic region and the distribution ink of Example 3 was 55 ° (hereinafter, this head may be referred to as “hydrophilic head”).

(Filling with filling liquid for logistics)
The logistics filling liquids of Examples and Comparative Examples are injected into an ink tank, and the ink tank is connected to a recording apparatus 100 (an ink jet printer, “LX-P5500” manufactured by Canon Finetech Co., Ltd.) shown in FIG. The filling liquid for physical distribution was filled in the nozzle flow path of the inkjet head. In Examples 1-14 and Comparative Examples 1-4, the water repellent head was used. In Comparative Example 5, the hydrophilic head was used, and the distribution filling liquid having the same composition as the distribution filling liquid of Example 3 was used.

(Possibility of printing inspection with logistics filling liquid)
After filling the distribution filling liquid, the recording apparatus 100 continuously applied 300,000 heat pulses to the heater of the ink jet head, printed the nozzle check pattern with the distribution filling liquid, and performed the print inspection. .

The nozzle check pattern has a length of 1. for each of the first nozzle and every 16 nozzles from the first nozzle (1/75 inch interval, 300 nozzles in total) out of the total 4800 nozzles of the inkjet head. A straight line of 5 mm is drawn (first row), and then a straight line having a length of 1.5 mm is drawn from the second nozzle and the second nozzle to every 16 nozzles (1/75 inch interval, total of 300 nozzles). The operation of (second column) is repeated 16 times in total (from the 3rd column to the 16th column), and a staircase pattern in which 300 lines × 16 columns per line and a total of 4800 lines are drawn is formed. Evaluation was performed by the number of undischarge nozzles in 4800 nozzles as follows. In principle, the number of discharge failure nozzles was counted by visually observing the print pattern. However, about Example 9 which uses DY86 which is difficult to visually observe as a dye, it visually observed in the state which irradiated the light of the LED lamp to the printing pattern. In addition, about the evaluation of the ink substitution property shown below and the image quality after ink substitution, it evaluated using the inkjet head without an undischarge nozzle at the time of a print test | inspection.
○: There is no ejection failure nozzle. Δ: There are 1 to 2 ejection failure nozzles. X: There are 3 or more ejection failure nozzles or adjacent ejection failure nozzles.

(Ink replaceability)
After the printing inspection with the distribution filling liquid, the ink jet head was removed from the recording device, packed in an aluminum pack, and stored at 60 ° C. for 2 weeks. After the storage, it is confirmed that the ink discharge port of the ink jet head is not fixed, the ink jet head is connected to the recording apparatus equipped with the ink tank into which the recording liquid is injected, and the nozzle flow path of the ink jet head by suction operation The logistics filling liquid was replaced with the recording liquid. As the recording liquid, Bk ink for the recording apparatus (manufactured by Canon Finetech Co., Ltd., Bk ink “BJI-P511Y” for LX-P5500) was used. Replacement with the recording liquid (ink replacement) was performed by a recovery sequence (recovery “large”) mounted on the recording apparatus.

After the ink replacement, the print inspection was performed by the same method as the distribution filling liquid. The recovery sequence was repeated until no color mixing due to the distribution filling liquid was confirmed in the print inspection. When the color mixing was not confirmed, the ink replacement was completed. The evaluation criteria were as follows. If the following evaluation is (circle) or (triangle | delta), it can be evaluated that there was no thickening and adhesion of an ink.
○: Ink replacement was completed in one recovery sequence Δ: Ink replacement was completed in two recovery sequences ×: Ink replacement was not completed in two recovery sequences

(Image quality after ink replacement)
After the ink replacement was completed, a print inspection was performed in the same manner as the distribution filling liquid using a photo paper for an inkjet printer (“PR-101” manufactured by Canon Inc.) as a recording medium. The evaluation criteria were as follows.
◎: No “sink printing” and no discharge nozzle ○: There is no adjacent “spin printing” and non-discharge nozzle, but there are 1 to 3 “spin printing” △: Adjacent “spin printing” and non-discharge nozzle No, but there are 4 to 5 “spinning prints” x: there are adjacent “spinning prints” or undischarge nozzles, or there are 6 or more “spinning prints”

  As shown in Table 3, Examples 1 to 14 using the packing material for physical distribution of the present invention showed good results in both ink replaceability and image quality after ink replacement.

  On the other hand, in Comparative Example 1 using a logistics filling liquid with a low dye content, the image quality after ink replacement was poor. In Comparative Example 2 using a distribution filling liquid having a high dye content, both the ink replacement property and the image quality after ink replacement were poor. Further, Comparative Example 3 using a distribution filling liquid in which a dye having a solubility equal to or higher than the saturation solubility in a water-soluble organic compound was dissolved, Comparative Example 4 using a distribution filling liquid having a low surface tension, and hydrophilicity at the periphery of the ink discharge port In Comparative Example 5 using the head in which the region was formed, the image quality after ink replacement was poor.

  The logistics filling liquid of the present invention can be used as a logistics filling liquid for an ink jet head in which a water-repellent region is formed at the periphery of an ink discharge port.

22, 22K, 22C, 22M, 22Y: head, 22Ks, 22Cs, 22Ms, 22Ys: face surface, 24: supply unit, 26: transport mechanism, 26a: transport belt, 26b: transport motor, 26c: roller, 40: recovery Unit: 50: Cap, 100: Recording device, 102: Host PC, 110: Base plate, 111: Heater substrate, 112: Common liquid chamber, 113: Top plate, 114: PCB (Electric wiring board), 115: Liquid supply member 116: liquid supply case, 117: liquid supply case cover, 118: supply filter, 119: discharge filter, 120: gas-liquid separator, 121: liquid level detection sensor, 123: upper limit detection electrode, 124: ground electrode, 125 : Lower limit detection electrode, 126: main liquid supply chamber, 127: liquid supply port, 129: main Liquid supply chamber inclination, 130: air communication portion, 131: liquid communication portion, 132: supply joint, 133: discharge joint, 134: first liquid supply chamber, 135: second liquid supply chamber, 136: second liquid supply chamber Opening, 137: liquid supply path, 138: second liquid supply chamber inclination, 139: nozzle arrangement surface, 141: air chamber, 151: ink discharge port, 152: heater, 153: nozzle wall, 155: nozzle filter, 156: Common liquid chamber, 157: heater center, 159: nozzle flow path, 161: top plate member, 162: nozzle top plate, 163: bottom plate portion, 164: nozzle bottom plate, 171: discharge port width, 172: discharge port height, 181: Nozzle front part, 182: Nozzle rear part, P: Recording medium.

Claims (19)

When the thermal ink jet head is distributed, the ink jet head filling liquid filled in the nozzle flow path communicating with the ink discharge port,
The inkjet head has an opening area of the ink discharge port of 100 to 350 μm ² and a water-repellent region formed on the periphery of the ink discharge port.
The dye is dissolved in an aqueous medium containing at least a water-soluble organic compound and water,
The dye is contained at a concentration of 0.2% by mass or more and 1% by mass or less with respect to the total mass of the logistics filling liquid, and at a concentration of saturated solubility or less with respect to the water-soluble organic compound,
A filling liquid for logistics of an ink jet head, wherein the surface tension is 35 mN / m or more.   The packing liquid for physical distribution according to claim 1, wherein the water-soluble organic compound is a water-soluble organic solvent having a vapor pressure at 20 ° C of 3 Pa or less.   The packing liquid for physical distribution according to claim 2, wherein a solution obtained by dissolving a solid water-soluble organic compound at 20 ° C in the water-soluble organic solvent is used as the water-soluble organic compound.   The packing liquid for physical distribution according to any one of claims 1 to 3, wherein the water-soluble organic compound is contained at a concentration of 40% by mass or less with respect to the total mass of the packing liquid for physical distribution.   Viscosity is 1.3 mPa * s or more and 5.0 mPa * s or less, The packing liquid for physical distribution given in any 1 paragraph of Claims 1-4. A thermal inkjet head,
The opening area of the ink discharge port is 100 to 350 μm ² , and a water-repellent region is formed on the periphery of the ink discharge port.
An inkjet head, wherein a nozzle flow path communicating with the ink discharge port is filled with the logistics filling liquid according to claim 1.   The inkjet head according to claim 6, wherein a water-repellent region having a contact angle with water of 90 ° or more is formed at a peripheral edge of the ink discharge port. A plurality of nozzle flow paths partitioned by the nozzle wall are formed,
A plurality of ink discharge ports communicating with the nozzle flow path are formed,
The ink jet head according to claim 6 or 7, wherein a heater is disposed inside each nozzle flow path.   The ink jet head according to claim 8, wherein the nozzle wall is formed of an epoxy-based photosensitive resin. A common liquid chamber in communication with the plurality of nozzle channels, an opening in communication with the common liquid chamber, a main liquid supply chamber in communication with the opening, and a liquid supply path in communication with the main liquid supply chamber; A liquid supply chamber that communicates with the liquid supply path, and the liquid supply chamber are disposed so as to be separated from the upstream side into a first liquid supply chamber and a second liquid supply chamber along a flow during liquid supply. A supply filter, a gas-liquid separation unit provided in a part of the main liquid supply chamber, and an air chamber communicating with the gas-liquid separation unit,
The nozzle flow path, the common liquid chamber, the opening, the main liquid supply chamber, the liquid supply path, the liquid supply chamber, the supply filter, the gas-liquid separator, and the air Chambers are arranged on a parallel plane with respect to a plane including the arrangement direction of the nozzle channels and the discharge direction of the liquid,
The inkjet head according to claim 8 or 9, wherein the main liquid supply chamber, the liquid supply path, the supply filter, the gas-liquid separator, and the air chamber are arranged without being stacked. .   The inkjet head according to any one of claims 6 to 10, wherein a resolution is 600 dpi or more, and a length of a nozzle row formed by the plurality of nozzle flow paths is 2 inches or more. An inkjet head logistics method for distributing thermal inkjet heads,
As the inkjet head, an ink discharge port having an opening area of 100 to 350 μm ² and a water-repellent region formed on the periphery of the ink discharge port is used.
A logistics method for an inkjet head, wherein the inkjet head is distributed in a state where the nozzle flow path communicating with the ink discharge port is filled with the logistics filling liquid according to any one of claims 1 to 5.   13. The physical distribution method according to claim 12, wherein the ink jet head uses a water repellent region having a contact angle with water of 90 ° or more around the periphery of the ink discharge port. The nozzle flow path is filled with a logistics filling liquid having a viscosity of 1.3 mPa · s or more and 5.0 mPa · s or less, and a printing inspection is performed with the logistics filling liquid.
14. The physical distribution method according to claim 12, wherein the ink jet head is distributed in a state where the nozzle flow path is filled with the physical distribution filling liquid.   As the inkjet head, a plurality of nozzle flow paths partitioned by nozzle walls are formed, a plurality of ink discharge ports communicating with the nozzle flow paths are formed, and a heater is disposed inside each nozzle flow path 15. The physical distribution method according to any one of claims 12 to 14, wherein   The physical distribution method according to claim 15, wherein the nozzle wall is formed of an epoxy photosensitive resin as the inkjet head.   As the inkjet head, a common liquid chamber that communicates with the plurality of nozzle channels, an opening that communicates with the common liquid chamber, a main liquid supply chamber that communicates with the opening, and a communication with the main liquid supply chamber A liquid supply path, a liquid supply chamber communicating with the liquid supply path, and the liquid supply chamber are separated into a first liquid supply chamber and a second liquid supply chamber from the upstream side along the flow during liquid supply. A supply filter, a gas-liquid separator provided in a part of the main liquid supply chamber, and an air chamber communicating with the gas-liquid separator, the nozzle channel, The common liquid chamber, the opening, the main liquid supply chamber, the liquid supply path, the liquid supply chamber, the supply filter, the gas-liquid separator, and the air chamber are the nozzle. Including the arrangement direction of the flow path and the discharge direction of the liquid The main liquid supply chamber, the liquid supply path, the supply filter, the gas-liquid separation unit, and the air chamber are arranged without being stacked on each other in a plane parallel to the plane. The physical distribution method according to claim 15 or 16, wherein the method is used.   18. The physical distribution method according to claim 12, wherein the inkjet head has a resolution of 600 dpi or more and a nozzle row formed by the plurality of nozzle channels has a length of 2 inches or more.   The logistics method according to any one of claims 12 to 18, wherein the inkjet head is distributed in a state of being mounted on a main body of an inkjet recording apparatus.

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